(19)
(11)EP 3 306 703 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
19.06.2019 Bulletin 2019/25

(21)Application number: 17195046.2

(22)Date of filing:  05.10.2017
(51)Int. Cl.: 
H01M 2/10  (2006.01)
H01M 10/46  (2006.01)
H01M 10/6554  (2014.01)
H01M 10/613  (2014.01)
H01M 10/42  (2006.01)
H01M 10/6551  (2014.01)
H01M 10/6235  (2014.01)
H01L 23/373  (2006.01)

(54)

BATTERY PACK AND ELECTRIC WORKING MACHINE

BATTERIEPACK UND ELEKTRISCHE ARBEITSMASCHINE

BLOC BATTERIE ET VÉHICULE DE TRAVAIL ÉLECTRIQUE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 07.10.2016 JP 2016199188

(43)Date of publication of application:
11.04.2018 Bulletin 2018/15

(73)Proprietors:
  • Makita Corporation
    Anjo-shi Aichi 446-8502 (JP)
  • Okitsumo Incorporated
    Nabari-shi, Mie 518-0751 (JP)

(72)Inventors:
  • SUZUKI, Hitoshi
    Anjo-shi, Aichi 446-8502 (JP)
  • TOYONAGA, Takashi
    Nabari-shi, Mie 518-0751 (JP)
  • KIMURA, Naoshi
    Nabari-shi, Mie 518-0751 (JP)

(74)Representative: Kramer Barske Schmidtchen Patentanwälte PartG mbB 
European Patent Attorneys Landsberger Strasse 300
80687 München
80687 München (DE)


(56)References cited: : 
EP-A1- 1 274 137
US-A1- 2009 284 230
JP-A- 2010 027 831
US-A1- 2016 260 649
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    BACKGROUND



    [0001] The present disclosure relates to a battery pack and an electric working machine, and to the corresponding devices.

    [0002] US 2016/0260649 A1 discloses a wavelength selective heat radiation material which selectively radiates heat radiation light corresponding to an infrared ray transmission wavelength region of a resin member. Further, US 2009/0284230 A1 discloses a thin battery module and a charging module capable of suppressing an increase in temperature of the battery in the battery module when the battery is being charged.

    [0003] Japanese Patent Publication No. 4547036 discloses a battery pack that is attached to an electric power tool. The battery pack includes therein an FET (i.e., field-effect transistor), and a heat sink.

    SUMMARY



    [0004] However, in the above-described battery pack, heat from the FET is discharged to the inside of the battery pack through the heat sink. Therefore, heat from the FET will stay in the battery pack, and the heat sink cannot effectively lower the temperature of the FET. It is also possible that poor dissipation of heat increases the temperature in the battery pack. This temperature rise may adversely affect components other than the FET (e.g., other electronic components, battery cells, etc.) in the battery pack. Further, such disadvantages resulting from the poor dissipation of heat can also occur in an electric working machine as well.

    [0005] It is an object to efficiently release heat from a built-in electronic component to the outside of a housing of a device such as a battery pack, an electric working machine or the like.

    [0006] The object is solved by a device for an electric working machine according to claim 1.

    [0007] A device according to one aspect of the present disclosure includes an electronic component, a metal plate, a housing, and a wavelength selective heat radiating member. The metal plate is thermally coupled to the electronic component. The housing is configured to house the electronic component and the metal plate.

    [0008] The wavelength selective heat radiating member is mounted on a surface of the metal plate, so as to face an inner side surface of a specific portion of the housing. The wavelength selective heat radiating member is configured to convert thermal energy from the electronic component into heat radiation having a wavelength that penetrates the specific portion of the housing, and emit the heat radiation toward the inner side surface of the specific portion of the housing.

    [0009] In such a device, the thermal energy from the electronic component is transmitted to the wavelength selective heat radiating member via the metal plate. The thermal energy is converted into heat radiation having a wavelength that can penetrate the specific portion of the housing by the wavelength selective heat radiating member, and emitted toward the inner side surface of the specific portion of the housing. Thus, the thermal energy from the electronic component penetrates the specific portion of the housing in the form of heat radiation, and is released to the outside of the housing.

    [0010] Therefore, the heat from the electronic component built in the device can be efficiently discharged to the outside of the housing. Heat from the electronic component is removed from the housing, which improves effect of lowering the temperature of the electronic component. Furthermore, since the temperature rise in the housing is reduced, the possibility that the temperature rise affects other components in the housing is also reduced.

    [0011] A thickness of the specific portion of the housing may be smaller than a thickness of a periphery of the specific portion in the housing. Small thickness improves heat dissipation from the specific portion of the housing. This is because, the smaller the thickness of the specific portion is, the more easily the heat radiation can penetrate the specific portion.

    [0012] The device may include a wall portion configured to inhibit air of a periphery of the wavelength selective heat radiating member from moving. The wall portion can inhibit the temperature of the wavelength selective heat radiating member from being lowered due to convection in the device. Therefore, it is possible to inhibit a decrease in conversion efficiency of thermal energy into heat radiation by the wavelength selective heat radiating member. The heat dissipation from the specific portion of the housing can be enhanced.

    [0013] According to one aspect of the present disclosure, a battery pack for an electric working machine may include an electronic component, a metal plate, a housing, and a selective heat radiating member.

    [0014] In this battery pack, the metal plate is thermally coupled to the electronic component. The housing is configured to house the electronic component and the metal plate. The wavelength selective heat radiating member is mounted on a surface of the metal plate, so as to face an inner side surface of a specific portion of the housing. The wavelength selective heat radiating member is configured to convert thermal energy from the electronic component to heat radiation having a wavelength that penetrates the specific portion of the housing, and emit the heat radiation toward the inner side surface of the specific portion.

    [0015] According to one aspect of the present disclosure, the housing of the battery pack may include an attachment portion for attachment to the electric working machine. An outer side surface of the specific portion of the housing may be a non-attachment portion of an outer side surface of the housing. According to this battery pack, effect of releasing thermal energy to the outside from the housing (i.e., heat dissipation effect) can be enhanced. This is because the release of thermal energy from the housing is not blocked by the main body of the electric working machine.

    [0016] According to one aspect of the present disclosure, an electric working machine may be provided that includes an electronic component, a metal plate, a housing, and a selective heat radiating member.

    [0017] In the electric working machine, the metal plate is thermally coupled to the electronic component. The housing is configured to house the electronic component and the metal plate. The wavelength selective heat radiating member is mounted on a surface of the metal plate, so as to face an inner side surface of a specific portion of the housing. The wavelength selective heat radiating member is configured to convert thermal energy from the electronic component into heat radiation having a wavelength that penetrates the specific portion of the housing, and emit the heat radiation toward the inner side surface of the specific portion.

    [0018] In such an electric working machine, thermal energy from the electronic component is transmitted to the wavelength selective heat radiating member via the metal plate. The thermal energy is converted into heat radiation having a wavelength that can penetrate the housing by the wavelength selective heat radiating member, and is emitted toward the inner side of the specific portion of the housing. Therefore, the thermal energy from the electronic component penetrates the specific portion of the housing in the form of heat radiation, and is released to the outside of the housing.

    [0019] Therefore, the heat from the electronic component built in the housing of the electric working machine can be efficiently released to the outside. In other words, heat from the electronic component is inhibited from staying in the electric working machine, and the effect of lowering the temperature of the electronic component is improved. Furthermore, since a temperature rise in the electric working machine can be reduced, the possibility that the temperature rise affects other components than the electronic component in the housing is also reduced.

    [0020] In the battery pack and/or the electric working machine, a thickness of the specific portion of the housing may be smaller than a thickness of a periphery of the specific portion in the housing. According to the thus constructed battery pack and/or the electric working machine, effect of heat dissipation from the specific portion of the housing is improved. This is because the smaller the thickness of the specific portion is, i.e., the thinner the specific portion is, the more easily the heat radiation penetrates that specific portion.

    [0021] The battery pack and/or the electric working machine may include a wall portion configured to inhibit air near a periphery of the wavelength selective heat radiating member from moving. According to the thus constructed battery pack and/or the electric working machine, the temperature of the wavelength selective heat radiating member is inhibited from being lowered due to convection in the housing. Therefore, it is possible to inhibit a decrease in conversion efficiency of thermal energy into heat radiation by the wavelength selective heat radiating member. The heat dissipation from the specific portion of the housing can be enhanced.

    [0022] The housing of the electric working machine may include a portion to which the battery pack is attached. The electric working machine may be configured so that electric power is supplied from the battery pack. In this case, an outer side surface of the specific portion of the housing may be a portion of an outer side surface of the housing different from the portion where the battery pack is attached. According to the electric working machine configured as described above, the effect of releasing thermal energy from the specific portion of the housing to the outside can be enhanced. This is because the release of thermal energy from the housing is not blocked by the battery pack.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0023] An example embodiment of the present disclosure will be described hereinafter by way of example with reference to the accompanying drawings, in which:

    FIG. 1 is a perspective view of a grinder in a state where a battery pack is attached;

    FIG. 2 is a perspective view of the grinder in a state where the battery pack is removed;

    FIG. 3 is a schematic diagram for illustrating a heat dissipation structure of a housing of the grinder; and

    FIG. 4 is a schematic diagram for illustrating a heat dissipation structure of the battery pack.


    DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS


    [1. Overall configuration of grinder]



    [0024] As an example of an electric working machine, FIGS. 1 and 2 show a grinder 1 of the present embodiment. The grinder 1 is an electric working machine that can perform processing such as grinding, polishing, cutting, etc. on a workpiece.

    [0025] As shown in FIGS. 1 and 2, the grinder 1 includes a main body 2 and a battery pack 50. The main body 2 includes a main housing 5, a tool bit 6, a cover 7, and an operation switch 8.

    [0026] The main housing 5, which is a housing of the main body 2, is made of resin, and at least partially forms an outer side surface of the main body 2. Inside the main housing 5, a motor 11 and a controller 13 shown in FIG. 3 are housed.

    [0027] The motor 11 is a power source of the grinder 1. The motor 11 is disposed at a front end of the main housing 5 (i.e., right side in FIG. 1). The motor 11 is an electric motor, and may be, but not limited to, a brushless motor, for example.

    [0028] The controller 13 (see FIG. 3) is configured to mainly control the motor 11. The controller 13 is disposed, for example, at a rear end of the main housing 5 (i.e. left side in FIG. 1).

    [0029] The rear end of the main housing 5 is provided with a battery attachment portion 9 for attaching the battery pack 50 to the main body 2. The battery pack 50 is configured to be attachable to and detachable from the battery attachment portion 9.

    [0030] As shown in FIG. 4, the battery pack 50 houses a plurality of batteries 52. Specifically, the plurality of batteries 52 are housed in a battery housing 51, which is a housing of the battery pack 50. Each of circles shown in FIG. 4 corresponds to one of the batteries 52. Each of the batteries 52 is called a battery cell or simply a cell.

    [0031] Electric power from the batteries 52 can be provided to the main body 2 when the battery pack 50 is attached to the main body 2, as shown in FIG. 1. Each electric load such as the motor 11, the controller 13, or the like in the main body 2 is configured to operate by the electric power supplied from the batteries 52.

    [0032] The tool bit 6 is a member for machining a workpiece by being in contact with the workpiece. The tool bit 6 is rotated and driven by the motor 11. Examples of the tool bit 6 include a grinding wheel, a cutting grindstone, a wire brush and the like.

    [0033] The cover 7 is used to protect a user from scattering of broken pieces of the workpiece and the tool bit 6 caused during processing of the workpiece by the tool bit 6. The cover 7 is formed in a substantially semicircular shape, so as to cover a part of an outer periphery of the tool bit 6.

    [0034] The operation switch 8 is a switch for rotating the tool bit 6. When the user presses the operating switch 8, the motor 11 is driven. Thereby, the tool bit 6 is rotated and driven.

    [0035] The controller 13 operates by electric power of the batteries 52 to control driving of the motor 11. When the operation switch 8 is pressed by the user, the controller 13 supplies the electric power to the motor 11 to rotate the motor 11.

    [2. Heat dissipation structure of housing]



    [0036] As shown in FIG. 3, the controller 13 includes a printed circuit board (hereinafter referred to as PCB) 21 and an electronic component 23 mounted on the PCB 21.

    [0037] Heat is generated from the electronic component 23. Therefore, measures to dissipate heat from the electronic component 23 are necessary. The electronic component 23 includes, for example, an electronic component related to driving of the motor 11. The electronic component 23 includes, for example, a switching element constituting an inverter that supplies electric power to the motor 11. The switching element is, for example, a power MOSFET. The switching element may be other types of transistors. The electronic component 23 may be an electronic component other than the switching element, with heat generation.

    [0038] A metal plate 25 serving as a heat sink is mounted on a surface 23a of the electronic component 23 opposite to the PCB 21. The metal plate 25 is thermally coupled to the electronic component 23. Specifically, the PCB 21 and the metal plate 25 are disposed so that the surface 23a of the electronic component 23 and a surface of the metal plate 25 are in contact with each other. Therefore, heat generated in the electronic component 23 is transmitted to the metal plate 25. Material of the metal plate 25 is, for example, aluminum, but may be a metal such as iron or copper. Between the electronic component 23 and the metal plate 25, an additional member (not shown) such as an elastic material having thermal conductivity may be provided.

    [0039] A sheet-like wavelength selective heat radiating member 27 is mounted on a surface 25a of the metal plate 25 opposite to the electronic component 23. The heat radiating member 27 is mounted on the surface 25a of the metal plate 25, for example, by an adhesive having high thermal conductivity. Thus, thermal energy from the electronic component 23 is transmitted to the heat radiating member 27 through the metal plate 25.

    [0040] The heat radiating member 27 converts the thermal energy from the electronic component 23 transmitted to the heat radiating member 27 into heat radiation having a wavelength that can penetrate the main housing 5 and emits the heat radiation from a surface 27a opposite to the metal plate 25. The heat radiating member 27 is, for example, an aluminum sheet on which a large number of micro-cavities which are two-dimensionally arranged are formed. Such a heat radiating member 27 is also called a metamaterial. In the present embodiment, the heat radiation having a wavelength that can penetrate the main housing 5 is a heat radiation in the infrared wavelength range (i.e., infrared light), but may be a heat radiation in another wavelength range. Examples of such heat radiating member 27 is disclosed in Japanese Unexamined Patent Application Publication No. 2014-33062.

    [0041] The surface 27a of the heat radiating member 27 is arranged so as to face an inner side surface 29a of a specific portion 29 of the main housing 5. Thus, the heat radiating member 27 is mounted on the surface 25a of the metal plate 25 so as to face the inner side surface 29a of the specific portion 29 of the main housing 5.

    [0042] An outer side surface 29b of the specific portion 29 of the main housing 5 is a portion (a non-attachment portion) of an outer side surface of the main housing 5 that is different from a portion (an attachment portion) where the battery pack 50 is attached or may be attached. For example, the upper side in FIG. 3 corresponds to the right side in FIG. 1. As shown in FIG. 1, the specific portion 29 of the main housing 5 is, for example, an upper portion near the rear end of the main housing 5. The upper side in FIG. 1 is the upper side when the grinder 1 is horizontally used.

    [0043] A thickness t1 of the specific portion 29 as shown in FIG. 3 is smaller than a thickness t2 of the other portion in the main housing 5 including a periphery of the specific portion 29. Specifically, a recess 31 that can house the heat radiating member 27 is formed inside the specific portion 29 of the main housing 5. A concave surface of the recess 31 corresponds to the inner side surface 29a facing the heat radiating member 27.

    [0044] The metal plate 25 is disposed so as to be brought into contact with an inner side surface 5a of a periphery of the recess 31 in the main housing 5. Therefore, the metal plate 25 is disposed so that the main housing 5 is brought into contact with the portion 25b of the surface 25a of the metal plate 25 of a periphery of the heat radiating member 27. For this reason, the heat radiating member 27 is brought into a substantially sealed state in the recess 31. That is, a wall portion 31a of the recess 31 perpendicular to the surface 25a of the metal plate 25 functions to hinder air of the periphery of the heat radiating member 27 from moving. There may be a slight gap between the portion 25b of the surface 25a of the metal plate 25 and the inner side surface 5a of the periphery of the recess 31 in the main housing 5.

    [0045] A distance L1 between the heat radiating member 27 and the inner side surface 29a is configured to be as small as possible. For example, the distance L1 corresponds to a tolerance range required for assembling, which is 0.5 mm or less.

    [3. Effect of heat dissipation structure of housing]



    [0046] According to the heat dissipation structure of the main housing 5 as described above, the following effects are achieved.

    (3a) The thermal energy from the electronic component 23 is transmitted to the heat radiating member 27 via the metal plate 25. The thermal energy is converted into heat radiation having a wavelength that can penetrate the main housing 5 by the heat radiating member 27 and is emitted toward the inner side surface 29a of the specific portion 29 of the main housing 5. Therefore, the thermal energy from the electronic component 23 penetrates the specific portion 29 of the main housing 5 in the form of heat radiation, and is released to the outside of the main housing 5.
    Therefore, the heat from the electronic component 23 built in the main housing 5 can be efficiently released to the outside of the main housing 5. Therefore, the heat from the electronic component 23 is removed from the grinder 1. Accordingly, effect of lowering the temperature of the electronic component 23 can be improved. Furthermore, temperature rise in the grinder 1 is inhibited. Therefore, the possibility that the temperature rise affects other components than the electronic component 23 is also reduced.

    (3b) The thickness t1 of the specific portion 29 of the main housing 5 is smaller than the thickness t2 of the portion other than the specific portion 29 of the main housing 5. Therefore, effect of releasing the thermal energy from the specific portion 29 of the main housing 5 to the outside (i.e., heat dissipation effect) can be enhanced. This is because the smaller the thickness t1 of the specific portion 29 is, the more easily the heat radiation penetrates the specific portion 29.

    (3c) The wall portion 31a of the main housing 5 hinders the air of the periphery of the heat radiating member 27 from moving. Therefore, the temperature of the heat radiating member 27 can be inhibited from being lowered due to convection in the grinder 1 (i.e., in the main housing 5). As a result, it is possible to inhibit a decrease in conversion efficiency of thermal energy into heat radiation by the heat radiating member 27. High conversion efficiency improves the heat dissipation from the specific portion 29 of the main housing 5.

    (3d) The outer side surface 29b of the specific portion 29 of the main housing 5 is a portion (a non-attachment portion) of the outer side surface of the main housing 5 that is different from the portion (the attachment portion) where the battery pack 50 is attached or may be attached. Therefore, release of thermal energy from the main housing 5 is not blocked by the battery pack 50. Such a heat dissipation structure can enhance the heat dissipation from the specific portion 29 of the main housing 5. In the main housing 5, the specific portion 29 facing the heat radiating member 27 is not limited to the portion of the wall of the main housing 5 indicated by a reference numeral "29" in FIG. 1.

    (3e) The distance L1 between the heat radiating member 27 and the specific portion 29 of the main housing 5 is made as small as possible. The small distance L1 improves the heat dissipation from the specific portion 29.


    [4. Heat dissipation structure of battery pack]



    [0047] As shown in FIG. 4, in the battery housing 51, the above-described plurality of batteries 52 are housed. Furthermore, a monitoring control circuit 53 is also housed in the battery housing 51. The battery housing 51 is made of resin. The battery housing 51 at least partially forms an outer side surface of the battery pack 50.

    [0048] In FIG. 4, an upper surface of the battery housing 51 is a surface facing the main body 2 when the battery housing 51 is attached to the main body 2 of the grinder 1. Therefore, the upper side in FIG. 4 corresponds to the right side in FIG. 1. The left side in FIG. 4 corresponds to the upper side in FIG. 1, for example. Terms "up", "down", "left", and "right" used in the description related to the battery pack 50 below correspond to directions shown in FIG 4.

    [0049] The monitoring control circuit 53 operates by electric power of the batteries 52. The monitoring control circuit 53 is configured, for example, to monitor electric current into and out of the batteries 52 (i.e., charging and discharging current), and/or a voltage of the batteries 52. The monitoring control circuit 53, when abnormality occurs in the electric current and/or voltage to be monitored, notifies the controller 13 of the grinder 1 of the occurrence of abnormality, and/or, disconnects a charge and discharge path of the batteries 52. The monitoring control circuit 53 includes a PCB 61, and an electronic component 63 mounted on the PCB 61.

    [0050] The electronic component 63 may include, for example, an electronic component associated with power supply. The electronic component 63, for example, includes a switching element provided in the charge and discharge path of the batteries 52 to switch between connection and disconnection of the charge and discharge path. The switching element is, for example, a power MOSFET. However, the switching element may be other types of transistors. The electronic component 63 may be an electronic component other than the switching element. The electronic component 63, for example, may be a current detection resistor provided in the charge and discharge path of the batteries 52. Heat is generated from the electronic component 63.

    [0051] As shown in FIG. 4, the PCB 61 of the monitoring control circuit 53 is provided on an upper side of the batteries 52 in the battery housing 51. The electronic component 63 is mounted on an upper surface of the PCB 61, namely, a surface 61a of the PCB 61 opposite to the batteries 52.

    [0052] A metal plate 65 serving as a heat sink is mounted on the surface 63a of the electronic component 63 opposite to the PCB 61. Specifically, in the battery housing 51, the PCB 61 and the metal plate 65 are fixed so that the surface 63a of the electronic component 63 and a surface of the metal plate 65 are brought into contact with each other. Therefore, the metal plate 65 is thermally coupled to the electronic component 63. Thus, heat generated in the electronic component 63 is transmitted to the metal plate 65. Material of the metal plate 65 is, for example, aluminum, but may be a metal such as iron or copper. Between the electronic component 63 and the metal plate 65, an additional member (not shown) such as an elastic material having thermal conductivity may be provided.

    [0053] The metal plate 65 is formed by bending a flat metal plate at a substantially right angle. The metal plate 65 includes a first flat plate portion 66, and a second flat plate portion 67. The first flat plate portion 66 is a flat plate-shaped portion of the metal plate 65 which extends in parallel to the PCB 61. The first flat plate portion 66 is in contact with the electronic component 63. The second flat plate portion 67 is a plate-like portion of the metal plate 65 which extends downward from a left end of the first flat plate portion 66. The second flat plate portion 67 is disposed substantially parallel to a specific portion 69 which is a part of a left side wall of the battery housing 51.

    [0054] In other words, in the battery housing 51, the metal plate 65 is fixed to the PCB 61 through the electronic component 63 so that the first flat plate portion 66 of the metal plate 65 contacts the electronic component 63 and the second flat plate portion 67 of the metal plate 65 is substantially parallel to the specific portion 69 of the battery housing 51.

    [0055] A heat radiating member 70 similar to the heat radiating member 27 is attached to a surface 67a of the second flat plate portion 67 on the side of the specific portion 69, i.e., a surface facing an inner side surface 69a of the specific portion 69. In other words, in the battery pack 50, the heat radiating member 70 is mounted on the surface 67a of the metal plate 65 so as to face the inner side surface 69a of the specific portion 69 in the battery housing 51.

    [0056] Thermal energy from the electronic component 63 is transmitted to the heat radiating member 70 via the metal plate 65. The heat radiating member 70 converts the thermal energy transmitted from the electronic component 63 via the metal plate 65 into heat radiation having a wavelength that can penetrate the battery housing 51 and emits the heat radiation toward the inner side surface 69a of the specific portion 69 in the battery housing 51. The heat radiation is a heat radiation in the infrared wavelength range (i.e., infrared light), but may be a heat radiation in another wavelength range. The heat radiating member 70 may be mounted on the surface 67a of the metal plate 65, for example, by an adhesive having high thermal conductivity.

    [0057] An outer side surface 69b of the specific portion 69 of the battery housing 51 is a portion of an outer side surface of the battery housing 51 different from the portion attached to the main body 2 of the grinder 1.

    [0058] Further, a thickness t3 of the specific portion 69 that faces the heat radiating member 70 in the battery housing 51 is smaller than a thickness t4 of the other portion including a periphery of the specific portion 69 of the battery housing 51.

    [0059] Specifically, in the battery housing 51, a recess 71 having an area larger than the heat radiating member 70 is formed inside the specific portion 69. A concave surface of the recess 71 is the inner side surface 69a facing the heat radiating member 70.

    [0060] Further, a surface 70a of the heat radiating member 70 facing the specific portion 69 is on the same plane as the inner side surface 51a of a periphery of the recess 71 of the battery housing 51. In other words, this is a substantially "co-planar arrangement."

    [0061] Therefore, a wall portion 71a of the recess 71 perpendicular to the surface 67a of the second flat plate portion 67 of the metal plate 65 functions to hinder air of a periphery of the heat radiating member 70 from moving. However, the surface 70a of the heat radiating member 70 may not be on the same plane as the inner side surface 51a of the battery housing 51. In other words, a part in the thickness direction of the heat radiating member 70 may enter the recess 71, creating a "penetrating arrangement." A portion 67b of the surface 67a of the second flat plate portion 67 of the periphery of the heat radiating member 70 may be in contact with the inner side surface 51a of the battery housing 51, creating a "peripheral contact arrangement."

    [0062] The heat radiating member 70 and the inner side surface 69a are configured so that a distance L2 between the heat radiating member 70 and the inner side surface 69a is as small as possible. For example, the distance L2 is a tolerance range required for assembling, which is specifically 1 mm or less.

    [5. Effect by heat dissipation structure of battery pack]



    [0063] According to the heat dissipation structure of the battery pack 50 as described above, the following effects are achieved.

    (5a) The thermal energy from the electronic component 63 is transmitted to the heat radiating member 70 through the metal plate 65. The thermal energy is converted to heat radiation having a wavelength that can penetrate the battery housing 51 by the heat radiating member 70, and emitted toward the inner side surface 69a of the specific portion 69 of the battery housing 51. Therefore, the thermal energy, in the form of heat radiation, penetrates the specific portion 69 of the battery housing 51, and is discharged to the outside of the battery housing 51.
    Therefore, the heat from the electronic component 63 built in the battery housing 51 can be efficiently discharged to the outside of the battery housing 51. Thus, the heat from the electronic component 63 is inhibited from staying in the battery pack 50. The effect of lowering the temperature of the electronic component 63 is improved. Furthermore, temperature rise in the battery pack 50 is inhibited. Therefore, the possibility that the temperature rise affects other components than the electronic component 63 is also reduced.

    (5b) The thickness t3 of the specific portion 69 of the battery housing 51 is smaller than the thickness t4 of the other portion of the battery housing 51. Therefore, the effect of releasing the thermal energy to the outside from the specific portion 69 of the battery housing 51 (i.e., heat dissipation effect) can be enhanced. This is because the smaller the thickness t3 of the specific portion 69 is, the more easily the heat radiation penetrates the specific portion 69.

    (5c) The wall portion 71a of the battery housing 51 hinders the air of the periphery of the heat radiating member 70 from moving. Therefore, the temperature of the heat radiating member 70 can be inhibited from being lowered by convection inside the battery pack 50 (i.e., inside the battery housing 51). As a result, it is possible to maintain a high conversion efficiency of thermal energy to heat radiation by the heat radiating member 70. High conversion efficiency improves the heat dissipation from the specific portion 69 of the battery housing 51.

    (5d) The outer side surface 69b of the specific portion 69 of the battery housing 51 is a portion of the outer side surface of the battery housing 51 different from the portion attached to the main body 2 of the grinder 1. Therefore, release of thermal energy from the battery housing 51 is not blocked by the main body 2. Such a heat dissipation structure can enhance the heat dissipation from the specific portion 69 of the battery housing 51. In the battery housing 51, the specific portion 69 that faces the heat radiating member 70 may be a part of a lower wall or a part of a right wall of the battery housing 51 in FIG. 4.

    (5e) The distance L2 between the heat radiating member 70 and the specific portions 69 of the battery housing 51 is made as small as possible. Small distance L2 improves the heat dissipation from the specific portion 69.


    [6. Other embodiments]



    [0064] An embodiment of the present disclosure has been described in the above, but the present disclosure is not limited to the above embodiment and can be modified in various ways within in the scope of the appended claims.

    [0065] For example, the present disclosure can be applied to various electric working machines such as an electric hammer, an electric hammer drill, an electric drill, an electric driver, an electric wrench, an electric reciprocating saw, an electric jigsaw, an electric cutter, an electric chainsaw, an electric plane, an electric circular saw, an electric nailer including an electric tacker, an electric hedge trimmer, an electric lawn mower, an electric lawn trimmer, electric grass cutter, an electric cleaner, an electric blower and the like.

    [0066] Further, a plurality of function of a single component in the above embodiment may be implemented by a plurality of components, and one of the function of a single component may be implemented by a plurality of components. Further, a plurality of functions of a plurality of components may be implemented by a single component, and one of the functions implemented by a plurality of components may be implemented by a single component. Also, part of the configuration of the above embodiment may be omitted. Any aspect included in the technical idea specified from the language as set forth in the appended claims is an embodiment of the present disclosure. The present disclosure can also be implemented in various forms such as a heat dissipation method of a battery pack, a heat dissipation method of an electric working machine, or the like.


    Claims

    1. A device (2; 50) for an electric working machine, the device (2; 50) comprising:

    an electronic component (23; 63);

    a metal plate (25; 65) thermally coupled to the electronic component (23; 63);

    a housing (5; 51) configured to house the electronic component (23; 63) and the metal plate (25; 65); and

    a wavelength selective heat radiating member (27; 70) mounted on a surface of the metal plate (25; 65) so as to face an inner side surface (29a; 69a) of a specific portion (29; 69) of the housing (5; 51), and configured to convert thermal energy from the electronic component (23; 63) into heat radiation having a wavelength in an infrared wavelength range that penetrates the specific portion (29; 69) of the housing (5; 51), and to emit the heat radiation toward the inner side surface (29a; 69a) of the specific portion (29; 69) of the housing (5; 51),

    wherein a thickness of the specific portion (29; 69) of the housing (5; 51) is smaller than a thickness of a periphery of the specific portion (29; 69) in the housing (5; 51).


     
    2. The device (2; 50) according to claim 1, further comprising
    a wall portion (31a; 71a) configured to inhibit air near a periphery of the wavelength selective heat radiating member (27; 70) from moving.
     
    3. The device (2; 50) according to claim 1 or 2,
    wherein the housing (5; 51) includes a recess (31; 71) facing the wavelength selective heat radiating member (27; 70) at the specific portion (29; 69), the recess (31; 71) being configured to inhibit air between the specific portion (29; 69) and the wavelength selective heat radiating member (27; 70) from moving.
     
    4. A device (2; 50) according to any one of claims 1 to 3,
    wherein the metal plate (65) includes a first flat plate portion (66), and a second flat plate portion (67) extending from the first plate portion (66), the second flat plate portion (67) having an angle with respect to the first flat plate portion (66),
    wherein the electronic component (63) is in contact with the first flat plate portion (66), and the wavelength selective heat radiating member (70) is in contact with the second flat plate portion (67).
     
    5. The device (2; 50) according to any one of claims 1 to 4,
    wherein the electronic component (23; 63) includes a field effect transistor such as a power MOSFET.
     
    6. A battery pack (50) for an electric working machine, the battery pack (50) comprising a device (50) according to any one of claims 1 to 5.
     
    7. The battery pack (50) according to claim 6,
    wherein an outer side surface of the housing (51) at least partially forms an outer side surface of the battery pack (50).
     
    8. The battery pack (50) according to claim 6 or 7,
    wherein the electronic component (63) includes an electronic component associated with a power supply, in particular a switching element configured to connect and disconnect a charge and/or discharge path.
     
    9. The battery pack (50) according to any one of claims 6 to 8,
    wherein the housing (51) includes an attachment portion for attachment to the electric working machine (2), and
    an outer side surface of the specific portion (69) of the housing (51) is a non-attachment portion of an outer side surface of the housing (51).
     
    10. An electric working machine (2) comprising:
    a device (2) according to any one of claims 1 to 5.
     
    11. The electric working machine (2) according to claim 10,
    wherein an outer side surface of the housing (5) at least partially forms an outer side surface of the electric working machine (2).
     
    12. The electric working machine (2) according to claim 10 or 11, further comprising
    a motor (11),
    wherein the electronic component (23) includes an electronic component, such as an inverter, associated with driving of the motor (11).
     
    13. The electric working machine (2) according to any one of claims 10 to 12,
    wherein the housing (5) includes a portion (9) where a battery pack (50) is attached,
    wherein the electric working machine (2) is configured to receive electric power from the battery pack (50), and
    wherein an outer side surface (29b) of the specific portion (29) of the housing (5) is a portion of an outer side surface of the housing (5) different from the portion (9) where the battery pack (50) is attached.
     


    Ansprüche

    1. Vorrichtung (2; 50) für ein elektrisches Arbeitsgerät, mit
    einer elektronischen Komponente (23; 63),
    einer Metallplatte (25; 65), die thermisch mit der elektronischen Komponente (23; 63) gekoppelt ist,
    einem Gehäuse (5; 51), das zum Aufnehmen der elektronischen Komponente (23; 63) und der Metallplatte (25; 65) konfiguriert ist, und
    einem wellenselektives Wärmeabstrahlbauteil (27; 70), das auf eine Oberfläche der Metallplatte (25; 65) derart montiert, dass es einer Innenseitenoberfläche (29a; 69a) eines spezifischen Bereiches (29; 69) des Gehäuses (5; 51) gegenüberliegt und zum Umwandeln thermischer Energie von der elektronischen Komponente (23; 63) in Wärmestrahlung, die eine Wellenlänge in einem Infrarotwellenlängenbereich aufweist, die den spezifischen Bereich (29; 69) des Gehäuses (5; 51) durchdringt, und zum Emittieren der Wärmestrahlung in Richtung der Innenseitenoberfläche (29a; 69a) des spezifischen Bereiches (29; 69) des Gehäuses (5; 51) konfiguriert ist,
    bei dem eine Dicke des spezifischen Bereiches (29; 69) des Gehäuses (5; 51) kleiner als eine Dicke des Umfangs des spezifischen Bereiches (29; 69) in dem Gehäuse (5; 51) ist.
     
    2. Vorrichtung (2; 50) nach Anspruch 1, die ferner
    einen Wandbereich (31a; 71a) aufweist, der zum Verhindern, dass sich Luft neben einem Umfang des wellenselektiven Wärmeabstrahlbauteils (27; 70) bewegt, konfiguriert ist.
     
    3. Vorrichtung (2; 50) nach Anspruch 1 oder 2,
    bei dem das Gehäuse (5; 51) eine Ausnehmung (31; 71) aufweist, die dem wellenselektiven Wärmeabstrahlbauteil (27; 70) an dem spezifischen Bereich (29; 69) gegenüberliegt, bei dem die Ausnehmung (31; 71) derart konfiguriert ist, dass sie verhindert, dass sich Luft zwischen dem spezifischen Bereich (29; 69) und dem Wellenselektives Wärmeabstrahlbauteil (27; 70) bewegt.
     
    4. Vorrichtung (2; 50) nach einem der Ansprüche 1 bis 3,
    bei der die Metallplatte (65) einen ersten flachen Plattenbereich (66) und einen zweiten flachen Plattenbereich (67) aufweist, der sich von dem ersten Plattenbereich (66) erstreckt, und der zweite flache Plattenbereich (67) einen Winkel in Bezug auf den ersten flachen Plattenbereich (66) aufweist,
    bei dem die elektronische Komponente (63) in Kontakt mit dem ersten flachen Plattenbereich (66) ist und das wellenselektive Wärmeabstrahlbauteil (70) in Kontakt mit dem zweiten flachen Plattenbereich (67) ist.
     
    5. Vorrichtung (2; 50) nach einem der Ansprüche 1 bis 4,
    bei dem die elektronische Komponente (23; 63) einen Feldeffekttransistor, wie beispielsweise einen Leistungs-MOSFET aufweist.
     
    6. Batteriepack (50) für ein elektrisches Arbeitsgerät, bei dem das Batteriepack (50) eine Vorrichtung (50) nach einem Ansprüche 1 bis 5 aufweist.
     
    7. Batteriepack (50) nach Anspruch 6,
    bei dem eine Außenseitenoberfläche des Gehäuses (51) zumindest teilweise eine Außenseitenoberfläche des Batteriepacks (50) ausbildet.
     
    8. Batteriepack (50) nach einem der Ansprüche 6 oder 7,
    bei dem die elektronische Komponente (63) eine elektronische Komponente aufweist, die mit einer Leistungszufuhr assoziiert ist, im Speziellen ein Schaltelement, das dazu konfiguriert ist, einen Lade- und/oder Entladeweg zu verbinden und zu unterbrechen.
     
    9. Batteriepack (50) nach einem der Ansprüche 6 bis 8,
    bei dem das Gehäuse (51) einen Anbringungsbereich zum Anbringen an das elektrische Arbeitsgerät (2) aufweist, und
    eine Außenseitenoberfläche des spezifischen Bereichs (69) des Gehäuses (51) ein Nicht-Anbringungsbereich einer Außenseitenoberfläche des Gehäuses (51) ist.
     
    10. Elektrisches Arbeitsgerät (2), mit
    einer Vorrichtung (2) nach einem der Ansprüche 1 bis 5.
     
    11. Elektrisches Arbeitsgerät (2) nach Anspruch 10,
    bei dem eine Außenseitenoberfläche des Gehäuses (5) zumindest teilweise eine Außenseitenoberfläche des elektrischen Arbeitsgeräts (2) ausbildet.
     
    12. Elektrisches Arbeitsgerät (2) nach Anspruch 10 oder 11, das ferner
    einen Motor (11) aufweist,
    bei dem die elektronische Komponente (23) eine elektronische Komponente aufweist, wie beispielsweise einen Wechselrichter, der mit dem Antreiben des Motors (11) assoziiert ist.
     
    13. Elektrisches Arbeitsgerät (2) nach einem der Ansprüche 10 bis 12,
    bei dem das Gehäuse (5) einen Bereich (9) aufweist, bei welchem ein Batteriepack (50) angebracht wird,
    bei dem das elektrische Arbeitsgerät (2) zum Empfangen elektrischer Leistung von dem Batteriepack (50) konfiguriert ist, und
    bei dem eine Außenseitenoberfläche (29) des spezifischen Bereiches (29) des Gehäuses (5) ein Bereich einer Außenseitenoberfläche des Gehäuses (5) ist, der unterschiedlich von dem Bereich (9) ist, bei welchem das Batteriepack (50) angebracht wird.
     


    Revendications

    1. Dispositif (2 ; 50) pour une machine de travail électrique, le dispositif (2 ; 50) comprenant :

    un composant électronique (23 ; 63) ;

    une plaque métallique (25 ; 65) couplée thermiquement au composant électronique (23; 63) ;

    un boîtier (5 ; 51) configuré pour loger le composant électronique (23 ; 63) et la plaque métallique (25 ; 65) ; et

    un élément de rayonnement thermique sélectif en longueur d'onde (27 ; 70) monté sur une surface de la plaque métallique (25 ; 65) de manière à faire face à une surface latérale intérieure (29a ; 69a) d'une partie spécifique (29 ; 69) du boîtier (5 ; 51), et configuré pour convertir l'énergie thermique du composant électronique (23 ; 63) en rayonnement thermique ayant une longueur d'onde dans une plage de longueur d'onde infrarouge qui traverse la partie spécifique (29 ; 69) du boîtier (5 ; 51), et pour émettre le rayonnement thermique vers la surface latérale intérieure (29a ; 69a) de la partie spécifique (29 ; 69) du boîtier (5 ; 51),

    où une épaisseur de la partie spécifique (29 ; 69) du boîtier (5 ; 51) est inférieure à une épaisseur d'une périphérie de la partie spécifique (29 ; 69) dans le boîtier (5 ; 51).


     
    2. Dispositif (2 ; 50) selon la revendication 1, comprenant en outre
    une partie de paroi (31a ; 71a) configurée pour empêcher l'air près d'une périphérie de l'élément de rayonnement thermique sélectif en longueur d'onde (27 ; 70) de bouger.
     
    3. Dispositif (2 ; 50) selon la revendication 1 ou 2,
    dans lequel le boîtier (5 ; 51) comprend une cavité (31 ; 71) faisant face à l'élément de rayonnement thermique sélectif en longueur d'onde (27 ; 70) à la partie spécifique (29 ; 69), la cavité (31 ; 71) étant configuré pour empêcher l'air entre la partie spécifique (29 ; 69) et l'élément de rayonnement thermique sélectif en longueur d'onde (27 ; 70) de bouger.
     
    4. Dispositif (2 ; 50) selon l'une quelconque des revendications 1 à 3,
    où la plaque métallique (65) comprend une première partie de plaque plate (66), et une seconde partie de plaque plate (67) s'étendant depuis la première partie de plaque (66), la seconde partie de plaque plate (67) ayant un angle par rapport à la première partie de plaque plate (66),
    où le composant électronique (63) est en contact avec la première plaque plate (66), et l'élément de rayonnement thermique sélectif en longueur d'onde (70) est en contact avec la seconde partie de plaque plate (67).
     
    5. Dispositif (2 ; 50) selon l'une quelconque des revendications 1 à 4,
    où le composant électronique (23 ; 63) comprend un transistor à effet de champ tel qu'un MOSFET de puissance.
     
    6. Bloc-batterie (50) pour une machine de travail électrique, le bloc-batterie (50) comprenant un dispositif (50) selon l'une quelconque des revendications 1 à 5.
     
    7. Bloc-batterie (50) selon la revendication 6,
    où une surface latérale extérieure du boîtier (51) forme au moins partiellement une surface latérale extérieure du bloc-batterie (50).
     
    8. Bloc-batterie (50) selon la revendication 6 ou 7,
    où le composant électronique (63) comprend un composant électronique associé à une alimentation électrique, en particulier un élément de commutation configuré pour connecter et déconnecter un trajet de charge et/ou de décharge.
     
    9. Bloc-batterie (50) selon l'une quelconque des revendications 6 à 8,
    où le boîtier (51) comprend une partie de fixation destinée à être fixée à la machine de travail électrique (2), et
    une surface latérale extérieure de la partie spécifique (69) du boîtier (51) est une partie de non fixation d'une surface latérale extérieure du boîtier (51).
     
    10. Machine de travail électrique (2) comprenant :
    un dispositif (2) selon l'une quelconque des revendications 1 à 5.
     
    11. Machine de travail électrique (2) selon la revendication 10,
    où une surface latérale extérieure du boîtier (5) forme au moins partiellement une surface latérale extérieure de la machine de travail électrique (2).
     
    12. Machine de travail électrique (2) selon la revendication 10 ou 11, comprenant en outre
    un moteur (11),
    dans lequel le composant électronique (23) comprend un composant électronique, tel qu'un convertisseur, associé à l'entraînement du moteur (11).
     
    13. Machine de travail électrique (2) selon l'une quelconque des revendications 10 à 12,
    où le boîtier (5) comprend une partie (9) où un bloc-batterie (50) est fixé,
    où la machine de travail électrique (2) est configurée pour recevoir de l'énergie électrique provenant du bloc-batterie (50), et
    où une surface latérale extérieure (29b) de la partie spécifique (29) du boîtier (5) est une partie d'une surface latérale extérieure du boîtier (5) différente de la partie (9) où le bloc-batterie (50) est fixé.
     




    Drawing















    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description