(19)
(11)EP 2 615 212 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
27.02.2019 Bulletin 2019/09

(21)Application number: 11823388.1

(22)Date of filing:  18.08.2011
(51)International Patent Classification (IPC): 
E02F 9/20(2006.01)
F02D 29/04(2006.01)
G05B 13/02(2006.01)
B60W 10/08(2006.01)
B60W 10/30(2006.01)
E02F 9/22(2006.01)
F02D 31/00(2006.01)
F02D 29/00(2006.01)
F02D 45/00(2006.01)
B60W 10/06(2006.01)
B60W 10/103(2012.01)
B60W 20/00(2016.01)
F02D 41/02(2006.01)
G06F 17/00(2019.01)
(86)International application number:
PCT/JP2011/068694
(87)International publication number:
WO 2012/032909 (15.03.2012 Gazette  2012/11)

(54)

HYBRID CONSTRUCTION MACHINE WITH ENGINE CONTROLLER

HYBRIDBAUMASCHINE MIT ANTRIEBSMOTORSTEUERUNG

MACHINE DE CONSTRUCTION HYBRIDE AVEC DISPOSITIF DE COMMANDE DU MOTEUR


(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: 08.09.2010 JP 2010201102

(43)Date of publication of application:
17.07.2013 Bulletin 2013/29

(73)Proprietor: Hitachi Construction Machinery Co., Ltd.
Tokyo 110-0015 (JP)

(72)Inventors:
  • IMURA Shinya
    Hitachi-shi Ibaraki 319-1292 (JP)
  • ISHIDA Seiji
    Hitachi-shi Ibaraki 319-1292 (JP)
  • SATAKE Hidetoshi
    Tsuchiura-shi Ibaraki 300-0013 (JP)
  • KAJITA Yusuke
    Tsuchiura-shi Ibaraki 300-0013 (JP)
  • FUJISHIMA Kazuo
    Tsuchiura-shi Ibaraki 300-0013 (JP)
  • OOKI Takatoshi
    Tsuchiura-shi Ibaraki 300-0013 (JP)

(74)Representative: Manitz Finsterwald Patentanwälte PartmbB 
Postfach 31 02 20
80102 München
80102 München (DE)


(56)References cited: : 
WO-A1-2007/049767
JP-A- 2003 028 071
JP-A- 2007 290 607
JP-A- 2009 074 406
WO-A1-2009/038016
JP-A- 2004 150 305
JP-A- 2009 074 406
US-A1- 2009 320 461
  
      
    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

    TECHNICAL FIELD



    [0001] The present invention relates to a hybrid construction machine in which a hydraulic pump as a hydraulic source for a hydraulic actuator is driven by both an engine and an electric motor. Particularly, it relates to a unit for reducing fuel consumption without changing the operability of the hydraulic actuator. A hybrid construction machine comprising the features described in the preamble portion of patent claim 1 has been known from JP 2009-074406 A.

    BACKGROUND ART



    [0002] In recent years, an energy saving trend on industrial products has been strong in order to deal with the environmental problem, the problem of rise in the price of crude oil, etc. In response to the trend, hybridization using an engine and an electric motor together has been also examined in construction machines whose mainstream is a system in which a hydraulic drive system is heretofore driven only by an engine. By hybridization of a construction machine, it is possible to expect not only the effect of reduction in exhaust gas but also the effect of energy saving, including engine's high efficiency drive, improvement of efficiency in transmission, and recovery of regenerative electric power.

    [0003] In the background art, as a hybrid construction machine of this type, there has been proposed a hybrid construction machine, in which an electric motor (generator motor) is driven to engage in motoring or regenerating in accordance with power absorbed by a hydraulic pump so as to change the power distribution between an engine and the electric motor and operate the engine in a high-efficiency range in order to reduce the fuel consumption (for example, see JP 2007-290607 A).

    [0004] JP 2009-074406 A discloses a hybrid construction machine comprising: a variable displacement hydraulic pump which discharges hydraulic oil for a hydraulic actuator; an engine which drives the hydraulic pump; an electric motor which is driven by the engine to charge generated electric power into an electric storage device and which is driven by the electric power charged in the electric storage device so as to assist the engine to drive the hydraulic pump; and a controller which controls driving of the hydraulic pump, the engine and the electric motor; and which comprises an engine power calculating unit which calculates power generated by the engine.

    SUMMARY OF INVENTION


    TECHNICAL PROBLEM



    [0005] In order to further reduce the fuel consumption in the hybrid construction machine disclosed in JP 2007-290607 A, the rotation speed of the engine may be changed in accordance with the power absorbed by the hydraulic pump. However, when the rotation speed of the engine is changed in the configuration disclosed in JP 2007-290607 A, the discharge flow rate of the hydraulic pump also changes so that operation on the hydraulic actuator in response to the amount of operation on a lever differs from that in an ordinary construction machine that is not hybrid. Thus, a feeling of strangeness on operation may be given to an operator.

    [0006] An object of the present invention is to provide a hybrid construction machine which can provide the same operation feeling as an ordinary construction machine that is not hybrid without changing the discharge flow rate of a hydraulic pump even when the rotation speed of an engine is changed according to power absorbed by the hydraulic pump.

    [0007] According to the invention this object is accomplished with a hybrid construction machine comprising the features of patent claim 1.

    [0008] Dependent claims are directed on features of preferred embodiments of the invention.

    ADVANTAGEOUS EFFECTS OF INVENTION



    [0009] According to the present invention, the target rotation speed (real rotation speed) of the engine increases in accordance with the increase of engine power so that the fuel consumption can be reduced. In addition, the tilting angle of the hydraulic pump decreases in accordance with the increase of the engine rotation speed so that the discharge flow rate of hydraulic oil discharged from the hydraulic pump can be made constant. Thus, the operation on the hydraulic actuator in response to the amount of operation on the lever can be made similar to that in an ordinary construction machine that is not hybrid.

    BRIEF DESCRIPTION OF DRAWINGS



    [0010] 

    [Fig. 1] A block diagram showing the system configuration of a hybrid construction machine according to Example 1.

    [Fig. 2] A graph showing an example of a map provided in an engine power calculating unit.

    [Fig. 3] A graph showing an example of a map provided in a first rotation speed calculating unit.

    [Fig. 4] A graph showing an example of a map provided in a target maximum total power calculating unit.

    [Fig. 5] A graph showing an example of a map provided in a second rotation speed calculating unit.

    [Fig. 6] A graph showing an example of a map provided in a target flow rate calculating unit.

    [Fig. 7] A graph showing an example of a map provided in a third rotation speed calculating unit.

    [Fig. 8] A graph showing the operation of the invention.

    [Fig. 9] A block diagram showing the system configuration of a hybrid construction machine according to Example 2.

    [Fig. 10] A block diagram showing the system configuration of a hybrid construction machine according to Example 3.


    DESCRIPTION OF EMBODIMENTS



    [0011] Embodiments of hybrid construction machines according to the invention will be described below while hydraulic excavators are taken as examples.

    Example 1



    [0012] As shown in Fig. 1, a hybrid construction machine according to Example 1 has a variable displacement hydraulic pump 1 which discharges hydraulic oil for a not-shown hydraulic actuator, an engine 2 which drives the hydraulic pump 1, an electric motor 3 which is driven by the engine to charge generated electric power into a not-shown electric storage device and which is driven by the electric power charged in the not-shown electric storage device so as to assist the engine 2 to drive the hydraulic pump 1, and a controller 1A which controls driving of the hydraulicpump 1, the engine 2 and the electric motor 3. Further, the hybrid construction machine has an engine control dial (hereinafter abbreviated to "EC dial") 4 operated by an operator, and an operating lever 5.

    [0013] The controller 1A includes an engine power calculating unit 11 which calculates power generated by the engine 2, a first rotation speed calculating unit 12 which calculates a real rotation speed of the engine to minimize fuel required for generating the engine power, a target maximum total power calculating unit 13 which calculates a target maximum value of total power of the engine 2 and the electric motor 3, a second rotation speed calculating unit 14 which determines a lower limit of a target rotation speed of the engine 2, a target flow rate calculating unit 15 which calculates a target flow rate of the hydraulic oil discharged from the hydraulic pump 1, a third rotation speed calculating unit 16 which calculates a minimum rotation speed of the engine required for securing the target flow rate of the hydraulic pump 1, a target rotation speed calculating unit 17 which selects a largest value from the first rotation speed calculated by the first rotation speed calculating unit 12, the second rotation speed calculated by the second rotation speed calculating unit 14 and the third rotation speed calculated by the third rotation speed calculating unit 16, an engine control unit 18 which controls the engine 3 so as to make the real rotation speed of the engine close to the target rotation speed calculated by the target rotation speed calculating unit 17, an electric motor control unit 19 which controls torque generated in the electric motor 3 so as to make the real rotation speed of the engine 2 close to the target rotation speed calculated by the target rotation speed calculating unit 17, and a hydraulic pump control unit 20 which controls a tilting amount (displacement) of the hydraulic pump 1 based on the target flow rate outputted from the target flow rate calculating unit 15 and the real rotation speed of the engine 2.

    [0014] The variable displacement hydraulic pump 1 supplies hydraulic oil to a not-shown hydraulic actuator such as a boom, an arm, a bucket, etc. The displacement (amount of hydraulic oil discharged by one turn) of the hydraulic pump 1 can be changed by changing the tilting angle of a swash plate.

    [0015] The engine 2 is mechanically connected to the hydraulic pump 1 so that the engine 2 can drive and rotate the hydraulic pump 1. The engine 2 consumes fuel stored in a not-shown fuel tank and generates power. The power can be changed by changing the amount of fuel injection.

    [0016] The electric motor 3 is mechanically connected to the hydraulic pump 1 so that the electric motor 3 can drive and rotate the hydraulic pump 1. Thus, the electric motor 3 is also mechanically connected to the engine 2. The electric motor 3 may consume electric power of a not-shown electric storage device to generate power (motor), and may absorb inertial energy or the power generated in the engine 2 so as to generate (regenerate) power and store the power into the electric storage device.

    [0017] The EC dial 4 is designed so that the dial position thereof can be changed by an operator. In an ordinary hydraulic excavator that is not hybrid, the target rotation speed of the engine 2 is determined based on the dial position of the EC dial 4. In the invention, however, the target maximum total power of the engine 2 and the electric motor 3 is determined based on the dial position of the EC dial 4. The method for determining the target maximum total power will be described later.

    [0018] The operating lever 5 is provided for allowing the operator to operate a hydraulic actuator such as a boom, an arm, a bucket, etc.

    [0019] The engine power calculating unit 11 calculates the engine power based on the fuel injection amount and the rotation speed of the engine 2, for example, using a map shown in Fig. 2. The map is set based on the relationship among the fuel injection amount, the rotation speed and the generated power of the engine 2, which relationship is obtained by experiments or the like in advance.

    [0020] The first rotation speed calculating unit 12 calculates the first rotation speed which will be described below, based on the engine power calculated by the engine power calculating unit 11, for example, using a map shown in Fig. 3. That is, in the map, the engine rotation speed to minimize fuel required for generating each power of the engine 2 is set as the first rotation speed based on the relationship between the power and the engine rotation speed, which relationship is obtained by experiments or the like in advance.

    [0021] The target maximum total power calculating unit 13 calculates the target maximum total power based on the dial position of the EC dial 4, for example, using a map shown in Fig. 4. In the map, a maximum power that can be generated in each dial position of the EC dial 4 by an engine in an ordinal hydraulic excavator that is not hybrid is set as the target maximum total power based on the relationship between the dial position and the maximum power, which relationship is obtained by experiments or the like in advance. In this description, the "ordinary hydraulic excavator that is not hybrid" means a model whose engine power is substantially equal to the total power of the engine 2 and the electric motor 3 according to the invention.

    [0022] The second rotation speed calculating unit 14 calculates the following second rotation speed based on the target maximum total power calculated by the target maximum total power calculating unit 13, for example, using a map shown in Fig. 5. That is, in the map, each total power of the engine 2 and the electric motor 3 and the minimum engine rotation speed required for generating the power are set as the target maximum total power and the second rotation speed respectively based on the relationship between the total power and the minimum engine rotation speed, which relationship is obtained by experiments or the like in advance.

    [0023] The target flow rate calculating unit 15 calculates the target flow rate based on the dial position of the EC dial 4 and the amount of operation on the operating lever 5, for example, using a map shown in Fig. 6. In the map, each flow rate of a hydraulic pump in an ordinary hydraulic excavator that is not hybrid is set as the target flow rate based on the relationship among the dial position of the EC dial 4, the amount of operation on the operating lever 5 and the flow rate, which relationship is obtained by experiments or the like in advance.

    [0024] The third rotation speed calculating unit 16 calculates the following third rotation speed based on the target flow rate calculated by the target flow rate calculating unit 15, for example, using a map shown in Fig. 7. In the map, each flow rate of the hydraulic pump 1 and the minimum engine rotation speed required for securing the flow rate are set as the target flow rate and the third rotation speed based on the relationship between the flow rate and the engine rotation speed, which relationship is obtained by experiments or the like in advance.

    [0025] The target rotation speed calculating unit 17 selects the largest value from the first rotation speed, the second rotation speed and the third rotation speed.

    [0026] The engine control unit 18 controls the fuel injection amount or the fuel injection timing of the engine 2 so as to make the real rotation speed of the engine 2 close to the target rotation speed calculated by the target rotation speed calculating unit 17. For example, the rotation speed, the deviation of the target rotation speed and the integrated value of the deviation are multiplied by gains respectively, and fuel corresponding to a value obtained by the sum of those values is injected.

    [0027] The electric motor control unit 19 controls torque generated in the electric motor 3 so as to make the real rotation speed of the engine 2 close to the target rotation speed calculated by the target rotation speed calculating unit 17. For example, the rotation speed, the deviation of the target rotation speed and the integrated value of the deviation are multiplied by gains respectively, and torque corresponding to a value obtained by the sum of those values is generated. Torque generated in the electric motor 3 may be made high when the remaining amount of electric power in the electric storage device is large. Torque generated in the electric motor 3 may be made low or electric power may be generated when the remaining amount of electric power is small.

    [0028] Based on the real rotation speed of the engine 2 and the target flow rate calculated by the target flow rate calculating unit 15, the hydraulic pump control unit 20 calculates a target tilting angle of the hydraulic pump 1 using a map so as to change the tilting angle. The map is set based on the relationship among the engine rotation speed, the tilting angle and the flow rate, which relationship is obtained by experiments or the like in advance. The tilting angle is changed by hydraulic control or electric control. In the case of the hydraulic control, an electromagnetic valve is driven to control hydraulic pressure for changing the tilting angle. In the case of the electric control, an electric motor (another electric motor than the electric motor 3) for changing the tilting angle is driven to change the tilting angle.

    [0029] Restriction may be put on the change of the tilting angle by the hydraulic pump control unit 20 so as to prevent the power absorbed by the hydraulic pump 1 from exceeding the target maximum total power calculated by the target maximum total power calculating unit 13. Alternatively, restriction may be put on the target flow rate calculated by the target flow rate calculating unit 15 using a value obtained by dividing the target maximum total power by the discharge pressure of the hydraulic pump 1.

    [0030] Although one single hydraulic pump 1 is provided in the example of Fig. 1, a plurality of hydraulic pumps 1 may be provided. In that case, the same number of target flow rate calculating units 15 and the same number of hydraulic pump control units 20 as the number of hydraulic pumps 1 are provided. In addition, the third rotation speed calculating unit 16 calculates the third rotation speed based on the highest target flow rate of the target flow rates calculated by the target flow rate calculating units 15.

    [0031] The operation of the hybrid construction machine according to Example 1 will be described below with reference to Fig. 8. This example illustrates an example in which the fuel consumption becomes lower as the rotation speed increases when high power is generated by the engine 2.

    [0032] When the discharge pressure of the hydraulic pump 1 increases due to increase in load on the hydraulic actuator in a period in which the dial position of the EC dial 4 and the amount of operation on the operating lever 5 are fixed as shown in (a) of Fig. 8, the engine power increases correspondingly as shown in (b) of Fig. 8. When the engine power increases, the first rotation speed and the target rotation speed increase correspondingly as shown in (c) of Fig. 8. On this occasion, the second rotation speed and the third rotation speed remain unchanged because the dial position of the EC dial 4 and the amount of operation on the operating lever 5 are fixed. When the target rotation speed increases, the engine rotation speed increases correspondingly as shown in (d) of Fig. 8 so that the fuel consumption can be suppressed to minimum. In addition, when the engine rotation speed increases, the displacement of the hydraulic pump 1 decreases correspondingly as shown in (e) of Fig. 8. As a result, the flow rate of the hydraulic pump 1 becomes constant as shown in (f) of Fig. 8. Thus, the operation of the hydraulic actuator in response to the amount of operation on the lever can be made similar to that in an ordinary construction machine that is not hybrid.

    Example 2



    [0033] Next, the configuration of a hybrid construction machine according to Example 2 will be shown with reference to Fig. 9. As is apparent from this drawing, Example 2 of the invention is characterized in that the target rotation speed calculated by the target rotation speed calculating unit 17 is used in the hydraulic pump control unit 20 in place of the real rotation speed of the engine 2. The remaining is the same as that in the hybrid construction machine according to Example 1. Therefore, like parts are referred to by like signs correspondingly, and description thereof will be omitted. The target rotation speed changes more quickly than the real rotation speed. Example 2 is therefore effective in the case where it takes much time to change the tilting angle of the hydraulic pump 1.

    Example 3



    [0034] Next, the configuration of a hybrid construction machine according to Example 3 will be shown with reference to Fig. 10. As is apparent from this drawing, Example 3 of the invention is characterized in that the flow rate and the discharge pressure of the hydraulic pump 1, the power of the electric motor 3 and the load of accessories such as an air conditioner are used in the engine power calculating unit 11 in place of the fuel injection amount and the rotation speed of the engine 2.

    [0035] That is, the engine power calculating unit 11 in Example 3 first multiplies the flow rate and the discharge pressure of the hydraulic pump 1 so as to calculate the power absorbed by the hydraulic pump 1. Next, the engine power calculating unit 11 calculates the power generated by the electric motor 3 based on the output of the electric motor control unit 19. Next, the engine power calculating unit 11 calculates the power consumed by accessories such as an air conditioner, for example, based on the condition of a switch of the air conditioner. Finally, the engine power calculating unit 11 sets, as the engine power, a value obtained by subtracting the power generated by the electric motor 3 from the sum of the power absorbed by the hydraulic pump 1 and the power consumed by the accessories. The remaining is the same as that in the hybrid construction machine according to Example 1. Therefore, like parts are referred by like signs correspondingly, and description thereof will be omitted.

    [0036] In the engine power calculating unit 11, the target flow rate calculated by the target flow rate calculating unit 15 may be used in place of the flow rate of the hydraulic pump 1. In addition, in the same manner as in Example 2, the target rotation speed calculated by the target rotation speed calculating unit 17 may be used in the hydraulic pump control unit 20 in place of the real rotation speed of the engine 2.

    REFERENCE SIGNS LIST



    [0037] 
    1
    hydraulic pump
    2
    engine
    3
    electric motor
    4
    engine control dial
    5
    operating lever
    11
    engine power calculating unit
    12
    first rotation speed calculating unit
    13
    target maximum total power calculating unit
    14
    second rotation speed calculating unit
    15
    target flow rate calculating unit
    16
    third rotation speed calculating unit
    17
    target rotation speed calculating unit
    18
    engine control unit
    19
    electric motor control unit
    20
    hydraulic pump control unit



    Claims

    1. A hybrid construction machine comprising: a variable displacement hydraulic pump (1) which discharges hydraulic oil for a hydraulic actuator; an engine (2) which drives the hydraulic pump (1); an electric motor (3) which is driven by the engine (2) to charge generated electric power into an electric storage device and which is driven by the electric power charged in the electric storage device so as to assist the engine to drive the hydraulic pump; and a controller (18, 19, 20) which controls driving of the hydraulic pump, the engine and the electric motor; and which comprises an engine power calculating unit (11) which calculates power generated by the engine (2), characterized in that:
    the controller (18, 19, 20) includes a first rotation speed calculating unit (12) which calculates a rotation speed of the engine (2) to minimize fuel required for generating the engine power, a second rotation speed calculating unit (14) which determines a lower limit of a target rotation speed of the engine (2), a target rotation speed calculating unit (17) which selects a larger one of a first rotation speed outputted from the first rotation speed calculating unit (12) and a second rotation speed outputted from the second rotation speed calculating unit (14), an engine control unit (18) which controls the engine (2) so as to make a real rotation speed of the engine (2) close to the target rotation speed, a target flow rate calculating unit (15) which calculates a target flow rate of the hydraulic oil discharged from the hydraulic pump (1), and a hydraulic pump control unit (20)which controls displacement of the hydraulic pump (1) based on the target flow rate and the real rotation speed or the target rotation speed of the engine (2).
     
    2. A hybrid construction machine according to Claim 1, characterized in that:
    the target flow rate calculating unit (15) calculates the target flow rate based on a dial position of an engine control dial (4) and an amount of operation on an operating lever (5) .
     
    3. A hybrid construction machine according to Claim 1, characterized in that:
    the engine power calculating unit (11) calculates the engine power based on an amount of fuel injection in the engine (2) and the rotation speed of the engine (2).
     
    4. A hybrid construction machine according to Claim 1, characterized in that:
    the engine power calculating unit (11) calculates the engine power based on the discharge flow rate and a discharge pressure of the hydraulic pump (1), the power of the electric motor (3) and a load of accessories.
     
    5. A hybrid construction machine according to Claim 1, characterized in that:

    a target maximum total power calculating unit (13) which calculates a target maximum value of total power of the engine (2) and the electric motor (3) is provided; and

    the second rotation speed calculating unit (14) calculates a minimum rotation speed of the engine (2) required for generating the target maximum total power in the engine (2) and the electric motor (3).


     
    6. A hybrid construction machine according to Claim 5, characterized in that:
    the target maximum total power calculating unit (13) calculates the target maximum total power based on a dial position of an engine control dial (4).
     
    7. A hybrid construction machine according to Claim 5, characterized in that:

    a third rotation speed calculating unit (16) which calculates a minimum rotation speed of the engine (2) required for securing a target flow rate of the hydraulic pump (1) is further provided; and

    the target rotation speed calculating unit (17) selects a largest value from a first rotation speed outputted from the first rotation speed calculating unit (12), a second rotation speed outputted from the second rotation speed calculating unit (14) and a third rotation speed outputted from the third rotation speed calculating unit (16).


     
    8. A hybrid construction machine according to Claim 1, characterized in that:
    the second rotation speed calculating unit (14) calculates a minimum rotation speed of the engine (2) required for securing a target flow rate of the hydraulic pump (1).
     


    Ansprüche

    1. Hybrid-Baumaschine, umfassend: eine variable hydraulische Verdrängerpumpe (1), die Hydrauliköl für ein hydraulisches Betätigungsorgan ausgibt; einen Motor (2), der die Hydraulikpumpe (1) antreibt; einen Elektromotor (3), der von dem Motor (2) angetrieben wird, um erzeugten elektrischen Strom in eine elektrische Speichervorrichtung zu laden, und der von dem elektrischen Strom, der in die elektrische Speichervorrichtung geladen wurde, angetrieben wird, um den Motor zu unterstützen, die hydraulische Pumpe anzutreiben; und eine Steuereinrichtung (18, 19, 20), die das Antreiben der Hydraulikpumpe, des Motors und des Elektromotors steuert; und die eine Motorleistungsberechnungseinheit (11) umfasst, die den von dem Motor (2) erzeugten Strom berechnet, dadurch gekennzeichnet, dass:
    die Steuereinrichtung (18, 19, 20) eine erste Drehzahlberechnungseinheit (12) beinhaltet, die eine Drehzahl des Motors (2) berechnet, um Kraftstoff, der für das Erzeugen der Motorleistung benötigt wird, zu minimieren, eine zweite Drehzahlberechnungseinheit (14), die eine Untergrenze einer Zieldrehzahl des Motors (2) bestimmt, eine Zieldrehzahlberechnungseinheit (17), die ein größeres eines einer ersten Drehzahl, die von der ersten Drehzahlberechnungseinheit (12) ausgegeben wird, und einer zweiten Drehzahl, die von der zweiten Drehzahlberechnungseinheit (14) ausgegeben wird, auswählt, eine Motorsteuereinheit (18), die den Motor (2) derart steuert, dass eine reale Drehzahl des Motors (2) nahe an der Zieldrehzahl liegt, eine Zielflussratenberechnungseinheit (15), die eine Zielflussrate des Hydrauliköls, das von der Hydraulikpumpe (1) ausgegeben wird, berechnet, und eine Hydraulikpumpensteuereinheit (20), die die Verdrängung der Hydraulikpumpe (1) auf Basis der Zielflussrate und der realen Drehzahl oder der Zieldrehzahl des Motors (2) steuert.
     
    2. Hybrid-Baumaschine nach Anspruch 1, dadurch gekennzeichnet, dass:
    die Zielflussratenberechnungseinheit (15) die Zielflussrate auf Basis einer Wählposition einer Motorsteuerwählscheibe (4) und eines Betätigungsbetrags an einem Betätigungshebel (5) berechnet.
     
    3. Hybrid-Baumaschine nach Anspruch 1, dadurch gekennzeichnet, dass:
    die Motorleistungsberechnungseinheit (11) die Motorleistung auf Basis eines Betrags der Kraftstoffeinspritzung in den Motor (2) und der Drehzahl des Motors (2) berechnet.
     
    4. Hybrid-Baumaschine nach Anspruch 1, dadurch gekennzeichnet, dass:
    die Motorleistungsberechnungseinheit (11) die Motorleistung auf Basis der Ausgabeflussrate und einem Ausgabedruck der Hydraulikpumpe (1), der Leistung des Elektromotors (3) und einer Last von Zubehör berechnet.
     
    5. Hybrid-Baumaschine nach Anspruch 1, dadurch gekennzeichnet, dass:

    eine Ziel-Maximalgesamtleistungs-Berechnungseinheit (13), die einen Ziel-Maximalwert der Gesamtleistung des Motors (2) und des Elektromotors (3) berechnet, bereitgestellt wird; und

    die zweite Drehzahlberechnungseinheit (14) eine Mindestdrehzahl des Motors (2) berechnet, die zum Erzeugen der Ziel-Maximalgesamtleistung in dem Motor (2) und dem Elektromotor (3) erforderlich ist.


     
    6. Hybrid-Baumaschine nach Anspruch 5, dadurch gekennzeichnet, dass:
    die Ziel-Maximalgesamtleistungs-Berechnungseinheit (13) die Ziel-Maximalgesamtleistung auf Basis einer Wählposition einer Motorsteuerwählscheibe (4) berechnet.
     
    7. Hybrid-Baumaschine nach Anspruch 5, dadurch gekennzeichnet, dass:

    eine dritte Drehzahlberechnungseinheit (16), die eine Mindestdrehzahl des Motors (2) berechnet, die für Sicherstellung einer Zielflussrate der Hydraulikpumpe (1) erforderlich ist, ferner bereitgestellt wird; und

    die Zieldrehzahlberechnungseinheit (17) einen größten Wert aus einer ersten Drehzahl, die von der ersten Drehzahlberechnungseinheit (12) ausgegeben wird, einer zweiten Drehzahl, die von der zweiten Drehzahlberechnungseinheit (14) ausgegeben wird, und einer dritten Drehzahl, die von der dritten Drehzahlberechnungseinheit (16) ausgegeben wird, auswählt.


     
    8. Hybrid-Baumaschine nach Anspruch 1, dadurch gekennzeichnet, dass:
    die zweite Drehzahlberechnungseinheit (14) eine Mindestdrehzahl des Motors (2) berechnet, die für Sicherstellung einer Zielflussrate der Hydraulikpumpe (1) erforderlich ist.
     


    Revendications

    1. Machine de construction hybride comprenant : une pompe hydraulique à cylindrée variable (1) qui décharge de l'huile hydraulique pour un actionneur hydraulique ; un moteur (2) qui entraîne la pompe hydraulique (1); et un moteur électrique (3) qui est entraîné par le moteur (2) pour charger de l'énergie électrique générée dans un dispositif d'accumulation électrique et qui est entraîné par l'énergie électrique chargée dans le dispositif d'accumulation électrique de manière à aider le moteur à entraîner la pompe hydraulique ; et un contrôleur (18, 19, 20) qui contrôle l'entraînement de la pompe hydraulique, du moteur, et du moteur électrique ; et qui comprend une unité de calcul de puissance du moteur (11) qui calcule la puissance générée par le moteur (2), caractérisée en ce que :
    le contrôleur (18, 19, 20) comprend une unité de calcul de première vitesse de rotation (12) qui calcule une vitesse de rotation du moteur (2) pour minimiser le carburant nécessaire pour générer la puissance du moteur, une unité de calcul de deuxième vitesse de rotation (14) qui détermine une limite inférieure d'une vitesse de rotation cible du moteur (2), une unité de calcul de vitesse de rotation cible (17) qui sélectionne une plus grande parmi une première vitesse de rotation sortie par l'unité de calcul de première vitesse de rotation (12) et une deuxième vitesse de rotation sortie par l'unité de calcul de deuxième vitesse de rotation (14), une unité de contrôle de moteur (18) qui contrôle le moteur (2) de manière à rendre une vitesse de rotation réelle du moteur (2) proche de la vitesse de rotation cible, une unité de calcul de débit cible (15) qui calcule un débit cible de l'huile hydraulique déchargée par la pompe hydraulique (1), et une unité de contrôle de pompe hydraulique (20) qui contrôle la cylindrée de la pompe hydraulique (1) sur la base du débit cible et la vitesse de rotation réelle ou la vitesse de rotation cible du moteur (1).
     
    2. Machine de construction hybride selon la revendication 1, caractérisée en ce que :
    l'unité de calcul de débit cible (15) calcule le débit cible sur la base d'une position de cadran d'un cadran de contrôle de moteur (4) et d'une quantité d'actionnement d'un levier de commande (5).
     
    3. Machine de construction hybride selon la revendication 1, caractérisée en ce que :
    l'unité de calcul de puissance du moteur (11) calcule la puissance du moteur sur la base d'une quantité d'injection de carburant dans le moteur (2) et de la vitesse de rotation du moteur (2).
     
    4. Machine de construction hybride selon la revendication 1, caractérisée en ce que :
    l'unité de calcul de puissance du moteur (11) calcule la puissance du moteur sur la base du débit de décharge et d'une pression de décharge de la pompe hydraulique (1), de la puissance du moteur électrique (3), et d'une charge d'accessoires.
     
    5. Machine de construction hybride selon la revendication 1, caractérisée en ce que :

    une unité de calcul de puissance totale maximale cible (13) qui calcule une valeur maximale cible d'une puissance totale du moteur (2) et du moteur électrique (3) est fournie ; et

    l'unité de calcul de deuxième vitesse de rotation (14) calcule une vitesse de rotation minimale du moteur (2) nécessaire pour générer la puissance totale maximale cible dans le moteur (2) et le moteur électrique (3).


     
    6. Machine de construction hybride selon la revendication 5, caractérisée en ce que :
    l'unité de calcul de puissance totale maximale cible (13) calcule la puissance totale maximale cible sur une position d'écran d'un écran de contrôle du moteur (4).
     
    7. Machine de construction hybride selon la revendication 5, caractérisée en ce que :

    une unité de calcul de troisième vitesse de rotation (16) qui calcule une vitesse de rotation minimale du moteur (2) nécessaire pour assurer un débit cible de la pompe hydraulique (1) est en outre fournie ; et

    l'unité de calcul de vitesse de rotation cible (17) sélectionne une valeur la plus grande parmi une première vitesse de rotation sortie par l'unité de calcul de première vitesse de rotation (12), une deuxième vitesse de rotation sortie par l'unité de calcul de deuxième vitesse de rotation (14), et une troisième vitesse de rotation sortie par l'unité de calcul de troisième vitesse de rotation (16).


     
    8. Machine de construction hybride selon la revendication 1, caractérisée en ce que :
    l'unité de calcul de deuxième vitesse de rotation (14) calcule une vitesse de rotation minimale du moteur (2) nécessaire pour assurer un débit cible de la pompe hydraulique (1).
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description