ELEVATOR APPARATUS

Abstract

 A car position detecting apparatus that has a position switch that can detect a detected body that is disposed on a car is disposed inside a hoistway. The car position detecting apparatus detects the presence or absence of the car in a predetermined region by presence or absence of detection of the detected body by the position switch. A sheave interlocking device has a displacing body that can be displaced in response to a rotational speed of a speed governor sheave that is rotated together with movement of the car. An overspeed detecting switch that can detect the displacing body is displaceable between a first detecting position at which the displacing body is detected when a speed value of the car is a predetermined first reference value, and a second detecting position at which the displacing body is detected when the speed value of the car is a second reference value that is higher than the first reference value. The overspeed detecting switch is displaced to the first detecting position by an electromagnetic displacing apparatus when the car is in the predetermined region, and is displaced to the second detecting position when the car is outside the predetermined region.

Description

TECHNICAL FIELD

[0001] The present invention relates to an elevator apparatus that has a car that is moved inside a hoistway.

BACKGROUND ART

[0002] Conventionally, elevator apparatuses have been proposed that activate a safety apparatus if a car speed exceeds a predetermined set speed. In these conventional elevator apparatuses, car position is detected from an amount of rotation of a rotating body that rotates together with the movement of the car, and the set speed mentioned above is changed in response to the car position. The set speed is lowered as the car position approaches terminal portions of the hoistway. Thus, reductions in sizes of buffers that are disposed in a pit portion of the hoistway can be achieved, and overall height of the hoistway can be shortened (See Patent Literature 1).

[0003] 

[Patent Literature 1]
Japanese Patent Laid-Open No. 2003-104646 (Gazette)

DISCLOSURE OF THE INVENTION

PROBLEM TO BE SOLVED BY THE INVENTION

[0004] However, in conventional elevator apparatuses such as that described above, because the car position is found from the amount of rotation of the rotating body, it is necessary to adjust a relationship between car position and amount of rotation of the rotating body separately for each height of a hoistway in a building during installation of the elevator apparatus. Consequently, elevator apparatus installation work is time-consuming.

[0005] The present invention aims to solve the above problems and an object of the present invention is to provide an elevator apparatus that can be installed easily, and that enables size reductions in a hoistway.

MEANS FOR SOLVING THE PROBLEM

[0006] In order to achieve the above object, according to one aspect of the present invention, there is provided an elevator apparatus characterized in including: a car on which a detected body is disposed, and that is moved inside a hoistway; a car position detecting apparatus that has a position switch that is disposed inside the hoistway and that can detect the detected body, the car position detecting apparatus detecting presence or absence of the car in a predetermined region that is positioned in a terminal portion of the hoistway by presence or absence of detection of the detected body by the position switch; a speed governor sheave that is rotated together with movement of the car; a sheave interlocking device that has a displacing body that can be displaced in response to rotational speed of the speed governor sheave; an overspeed detecting switch that is displaceable between a first detecting position at which the displacing body is detected when a speed value of the car is a predetermined first reference value, and a second detecting position at which the displacing body is detected when the speed value of the car is a second reference value that is higher than the first reference value; an electromagnetic displacing apparatus that displaces the overspeed detecting switch to the first detecting position when the car is in the predetermined region, and displaces the overspeed detecting switch to the second detecting position when the car is outside the predetermined region, based on information from the car position detecting apparatus; and a control apparatus that controls elevator operation based on information from the overspeed detecting switch.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] 

Figure 1 is a structural diagram that shows an elevator apparatus according to Embodiment 1 of the present invention;

Figure 2 is a longitudinal section that shows a speed governor from Figure 1;

Figure 3 is a longitudinal section that shows the speed governor when a car from Figure 1 is outside both a lower end portion region and an upper end portion region;

Figure 4 is a circuit diagram that shows electrically connected states of lower portion position switches, upper portion position switches, and an electromagnet from Figure 1;

Figure 5 is a circuit diagram that shows a state in which cam detection by all of the lower portion position switches and the upper portion position switches from Figure 4 has stopped; and

Figure 6 is a graph showing relationships between normal operating speed and car position and between shutdown speed and car position for the car from Figure 1.

BEST MODE FOR CARRYING OUT THE INVENTION

[0008] A preferred embodiment of the present invention will now be explained with reference to the drawings.

Embodiment 1

[0009] Figure 1 is a structural diagram that shows an elevator apparatus according to Embodiment 1 of the present invention. In the figure, a machine room 2 is disposed in an upper portion of a hoistway 1. Disposed inside the machine room 2 are: a hoisting machine (a driving machine) 4 that has a drive sheave 3; a deflecting sheave 5 that is disposed so as to be positioned at a distance from the drive sheave 3; and a control apparatus 6 that controls elevator operation.

[0010] A common main rope 7 is wound around the drive sheave 3 and the deflecting sheave 5. A car 8 and a counterweight 9 that can be raised and lowered inside the hoistway 1 are suspended by the main rope 7. The car 8 and the counterweight 9 are raised and lowered inside of the hoistway 1 by rotation of the drive sheave 3. When the car 8 and the counterweight 9 are raised and lowered inside the hoistway 1, the car 8 is guided by car guide rails (not shown), and the counterweight 9 is guided by counterweight guide rails (not shown).

[0011]  An emergency stopper apparatus 10 that stops falling of the car 8 is disposed on a lower portion of the car 8. An operating arm 11 is disposed on the emergency stopper apparatus 10. The emergency stopper apparatus 10 grips the car guide rails when the operating arm 11 is operated. Movement of the car 8 is stopped by gripping of the car guide rails by the emergency stopper apparatus 10.

[0012] A speed governor 12 is disposed inside the machine room 2, and a tension sheave 13 is disposed in a lower portion inside the hoistway 1. The speed governor 12 has: a speed governor main body 14; and a speed governor sheave 15 that is disposed on the speed governor main body 14. A speed governor rope 16 is wound around the speed governor sheave 15 and the tension sheave 13. A first end portion and a second end portion of the speed governor rope 16 are connected to the operating arm 11. The speed governor sheave 15 and the tension sheave 13 are thereby rotated together with movement of the car 8.

[0013] The speed governor main body 14 grips the speed governor rope 16 if rotational speed of the speed governor sheave 15 reaches a predetermined emergency overspeed. The operating arm 11 is operated by the speed governor rope 18 being gripped by the speed governor main body 14 and the car 8 being displaced relative to the speed governor rope 16.

[0014] A cam (a detected body) 17 that is parallel to the direction of movement of the car 8 is disposed on a side surface of the car 8. A predetermined lower end portion region that is positioned in a lower end portion (a terminal portion) of the hoistway 1 and a predetermined upper end portion region that is positioned in an upper end portion (a terminal portion) of the hoistway 1 are set inside the hoistway 1. The lower end portion region and the upper end portion region are regions that have predetermined lengths in the direction of movement of the car 8. A lower end car position detecting apparatus 18 that detects the presence or absence of the car 8 in the lower end portion region, and an upper end car position detecting apparatus 19 that detects the presence or absence of the car 8 in the upper end portion region are disposed inside the hoistway 1.

[0015]  The lower end car position detecting apparatus 18 has a plurality of (in this example, three) lower portion position switches 18a, 18b, and 18c that can detect the cam 17. Each of the lower portion position switches 18a through 18c is disposed in a lower portion inside the hoistway 1. The lower portion position switches 18a through 18c are disposed so as to be spaced apart from each other in the direction of movement of the car 8.

[0016] The upper end car position detecting apparatus 19 has a plurality of (in this example, three) upper portion position switches 19a, 19b, and 19c that can detect the cam 17. Each of the upper portion position switches 19a through 19c is disposed in a upper portion inside the hoistway 1. The upper portion position switches 19a through 19c are disposed so as to be spaced apart from each other in the direction of movement of the car 8.

[0017] At least one of the lower portion position switches 18a through 18c is operated by the cam 17 when the car 8 is in the lower end portion region. At least one of the upper portion position switches 19a through 19c is operated by the cam 17 when the car 8 is in the upper end portion region. The respective lower portion position switches 18a through 18c and the respective upper portion position switches 19a through 19c detect the cam 17 by being operated by the cam 17. When the car 8 is in an intermediate portion inside the hoistway 1 so as to be outside both the lower end portion region and the upper end portion region, operation by the cam 17 is released on all of the lower portion position switches 18a through 18c and the upper portion position switches 19a through 19c.

[0018] In other words, the lower end car position detecting apparatus 18 detects the presence or absence of the car 8 in the lower end portion region by the presence or absence of detection of the cam 17 by the respective lower portion position switches 18a through 18c. The upper end car position detecting apparatus 19 detects the presence or absence of the car 8 in the upper end portion region by the presence or absence of detection of the cam 17 by the respective upper portion position switches 19a through 19c.

[0019] The length of the cam 17 is longer than a spacing between the lower portion position switches 18a through 18c and between the upper portion position switches 19a through 19c. Thus, a state in which none of the lower portion position switches 18a through 18c can detect the cam 17 when the car 8 is moved through the lower end portion region is prevented from occurring. A state in which none of the upper portion position switches 19a through 19c can detect the cam 17 when the car 8 is moved through the upper end portion region is also prevented from occurring.

[0020] The lower portion position switches 18a through 18c and the upper portion position switches 19a through 19c are connected in series by electric wires 20. A car buffer 21 that is positioned below the car 8, and a counterweight buffer 22 that is positioned below the counterweight 9 are disposed in a bottom portion (a pit portion) of the hoistway 1. When subjected to a collision with the car 8, the car buffer 21 relieves mechanical shock that is imparted to the car 8. When subjected to a collision with the counterweight 9, the counterweight buffer 22 relieves mechanical shock that is imparted to the counterweight 9.

[0021] Moreover, in Figure 1, a state is shown in which the car 8 is present in the lower end portion region, and two lower portion position switches 18a and 18b are simultaneously detecting the cam 17.

[0022] Figure 2 is a longitudinal section that shows the speed governor 12 from Figure 1. Figure 3 is a longitudinal section that shows the speed governor 12 when the car 8 from Figure 1 is outside both a lower end portion region and an upper end portion region. In the figures, the speed governor 12 is supported by a supporting body 23. Also supported by the supporting body 23 together with the speed governor 12 are: a sheave interlocking device 24 that operates interdependently with rotation of the speed governor sheave 15; an overspeed detecting switch 25 that is operated by the sheave interlocking device 24, and that outputs a stopping signal that stops elevator operation upon being operated; and an electromagnetic displacing apparatus 26 that displaces the overspeed detecting switch 25.

[0023] A sheave shaft 27 of the speed governor sheave 15 is supported horizontally in the speed governor main body 14 by means of bearings 28. A driving bevel gear 29 is fixed to an end portion of the sheave shaft 27.

[0024] The sheave interlocking device 24 has: a driven shaft 30 that is disposed so as to be parallel to a vertical direction; a driven bevel gear 31 that is fixed to a lower end portion of the driven shaft 30, and that intermeshes with the driving bevel gear 29; a displacing body 32 that is disposed on the driven shaft 30, and that is displaceable relative to the driven shaft 30 in a direction that is parallel to the driven shaft 30 (a predetermined direction); and a centrifugally displacing apparatus 33 that displaces the displacing body 32 in response to rotational speed of the driven shaft 30.

[0025] The driven shaft 30 is supported in the supporting body 23 by means of bearings 34. Rotation of the sheave shaft 27 is transmitted to the driven shaft 30 by means of the driving bevel gear 29 and the driven bevel gear 31. Consequently, the driven shaft 30 is rotated in response to the rotation of the speed governor sheave 15.

[0026] The centrifugally displacing apparatus 33 is disposed on an upper portion of the driven shaft 30. The centrifugally displacing apparatus 33 is rotated together with the driven shaft 30. In addition, the centrifugally displacing apparatus 33 has: a pair of arms 35 that can pivot relative to an upper end portion of the driven shaft 30; fly balls 36 that are disposed on leading end portions of the respective arms 35; a slipping cylinder 37 that is passed slidably over the driven shaft 30; linking members 38 that couple the respective arms 35 and the slipping cylinder 37; and a balancing spring 39 that forces the slipping cylinder 37 downward.

[0027] The fly balls 36 are subjected to a centrifugal force that corresponds to the rotational speed of the driven shaft 30, and are displaced in response to the centrifugal force that is received. The slipping cylinder 37 is displaced in a direction that is parallel to the driven shaft 30 in response to the displacement of the fly balls 36. Specifically, when the rotational speed of the driven shaft 30 increases, the fly balls 36 are displaced away from each other, and the slipping cylinder 37 is displaced upward in opposition to force from the balancing spring 39. When the rotational speed of the driven shaft 30 decreases, the fly balls 36 are displaced toward each other, and the slipping cylinder 37 is displaced downward by the force from the balancing spring 39.

[0028] The displacing body 32 is displaceable together with the slipping cylinder 37. The displacing body 32 is thereby displaced in a direction that is parallel to the driven shaft 30 in response to the rotational speed of the speed governor sheave 15. The displacing body 32 is also rotatable relative to the slipping cylinder 37 and the driven shaft 30. Consequently, a state of the displacing body 32 is maintained without being rotated even if the slipping cylinder 37 and the driven shaft 30 are rotated. In addition, the displacing body 32 has: a driven tube 40 that is passed slidably over the driven shaft 30; and an operating portion 41 that protrudes outward from an outer circumferential surface of the driven tube 40.

[0029] The overspeed detecting switch 25 is disposed radially outside the driven tube 40. The overspeed detecting switch 25 is displaceable in the direction that the displacing body 32 is displaced (i.e., vertically) due to guidance by a guiding member 42 that is disposed on the supporting body 23. In addition, the overspeed detecting switch 25 is displaceable between a predetermined first detecting position (Figure 2), and a second detecting position (Figure 3) that is positioned above the first detecting position.

[0030] The overspeed detecting switch 25 has: a switch main body 43; and a switch lever 44 that is disposed on the switch main body 43, and that projects outward toward the displacing body 32. An operating portion 41 can operate the switch lever 44 by displacement of the displacing body 32 relative to the overspeed detecting switch 25. The overspeed detecting switch 25 detects the displacing body 32 by the switch lever 44 being operated by the operating portion 41. A stopping signal that stops elevator operation is output from the switch main body 43 on detection of the displacing body 32 by the overspeed detecting switch 25.

[0031] The control apparatus 6 controls elevator operation based on information from the overspeed detecting switch 25. In this example, upon receiving the stopping signal from the overspeed detecting switch 25, the control apparatus 6 determines that an abnormality has arisen in the speed of the car 8, and performs control that stops elevator operation.

[0032]  The value of the speed of the car 8 when the overspeed detecting switch 25 detects the displacing body 32 (i.e., outputs the stopping signal) (shutdown speed) is set so as to be at a predetermined first reference value that is lower than a value of rated speed for the elevator when the overspeed detecting switch 25 is in the first detecting position (Figure 2), and be at a predetermined second reference value that is higher than the rated speed for the elevator (1.3 times the rated speed, for example) when the overspeed detecting switch 25 is in the second detecting position (Figure 3). The second reference value is a value that is lower than an emergency overspeed value at which the emergency stopper apparatus 10 acts.

[0033] The electromagnetic displacing apparatus 26 has: a forcing spring (a forcing body) 45 that forces the overspeed detecting switch 25 in a direction so as to be displaced to the first detecting position; a plunger 46 that is placed in contact with the switch main body 43; and an electromagnet 47 that displaces the plunger 46 in opposition to the force of the forcing spring 45 in a direction in which the overspeed detecting switch 25 is displaced to the second detecting position on receiving a supply of electric power.

[0034] The overspeed detecting switch 25 is displaced to the first detecting position by the supply of electric power to the electromagnet 47 being stopped. The overspeed detecting switch 25 is displaced to the second detecting position in opposition to the force of the forcing spring 45 by electric power being supplied to the electromagnet 47.

[0035] Figure 4 is a circuit diagram that shows electrically connected states of the lower portion position switches 18a through 18c, the upper portion position switches 19a through 19c, and the electromagnet 47 from Figure 1. Figure 5 is a circuit diagram that shows a state in which cam detection by all of the lower portion position switches 18a through 18c and the upper portion position switches 19a through 19c from Figure 4 has stopped. Moreover, Figure 4 is a diagram that shows a state in which only two lower portion position switches 18a and 18b are detecting the cam 17.

[0036] In the figures, the lower portion position switches 18a through 18c, the upper portion position switches 19a through 19c, and the coil of the electromagnet 47 are connected in series together with a direct current power supply 48 by the electric wires 20.

[0037] The lower portion position switches 18a through 18c and the upper portion position switches 19a through 19c each have a contact that opens and closes in response to the presence or absence of detection of the cam 17. The contacts of the lower portion position switches 18a through 18c and the upper portion position switches 19a through 19c open on detection of the cam 17, and close when detection of the cam 17 stops.

[0038] Thus, when all of the lower portion position switches 18a through 18c and the upper portion position switches 19a through 19c have stopped detecting the cam 17, all of the contacts are closed, and electric power is supplied to the coil of the electromagnet 47 from the direct current power supply 48. When at least one of the lower portion position switches 18a through 18c or the upper portion position switches 19a through 19c is detecting the cam 17, a portion of the contacts are open, and the supply of electric power to the coil of the electromagnet 47 is stopped.

[0039] As shown in Figure 5, when all of the lower portion position switches 18a through 18c and the upper portion position switches 13a through 19c have stopped detecting the cam 17 (i.e., when the car 8 is outside both the lower end portion region and the upper end portion region), the overspeed detecting switch 25 is displaced to the second detecting position by the electromagnetic displacing apparatus 26. As shown in Figure 4, when at least one of the lower portion position switches 18a through 18c or the upper portion position switches 19a through 19c is detecting the cam 17, (i.e., the car 8 is in either the lower end portion region or the upper end portion region), the overspeed detecting switch 25 is displaced to the first detecting position by the electromagnetic displacing apparatus 26. In other words, the electromagnetic displacing apparatus 26 displaces the overspeed detecting switch 25 between the first detecting position and the second detecting position based on respective information from the lower end car position detecting apparatus 18 and the upper end car position detecting apparatus 19.

[0040] Figure 6 is a graph showing relationships between normal operating speed and car position and between shutdown speed and car position for the car 8 from Figure 1. As shown in the figure, a value of a shutdown speed 51 is a value that is higher than a normal operating speed 52 for the car 8 at all positions through which the car 8 moves. When the car 8 is in either the lower end portion region or the upper end portion region, the overspeed detecting switch 25 is displaced to the first detecting position (Figure 2), and the value of the shutdown speed 51 becomes a first reference value V_os1. When the car 8 is in an intermediate portion inside the hoistway 1 outside both the lower end portion region and the upper end portion region, the overspeed detecting switch 25 is displaced to the second detecting position (Figure 3), and the value of the shutdown speed 51 becomes a second reference value V_os2 that is higher than the first reference value V_os1. The first reference value V_os1 is set so as to be lower than a rated speed value V₀, and the second reference value V_os2 is set so as to be greater than the rated speed value T₀.

[0041] Next, operation will be explained. If the car 8 is moved at the normal operating speed 52, elevator operation will not be stopped forcibly by information from the overspeed detecting switch 25 because the speed of the car 8 will not reach the shutdown speed 51.

[0042] If the speed of the car 8 increases and reaches the shutdown speed 51 for some reason, a stopping signal is sent to the control apparatus 6 from the overspeed detecting switch 25. When the control apparatus 6 receives the stopping signal, elevator operation is stopped forcibly by the control apparatus 6.

[0043] If the speed of the car 8 subsequently increases further and reaches an emergency overspeed despite shutdown control being performed by the control apparatus 6, the speed governor rope 16 is gripped by the speed governor 12. Thus, movement of the speed governor rope 16 stops, and the car 8 is displaced relative to the speed governor rope 16.

[0044] When the car 8 is displaced relative to the speed governor rope 16, the operating arm 11 is operated, and an operation that grips the car guide rails is performed by the emergency stopper apparatus 10. A braking force is thereby applied directly to the car 8.

[0045] Next, operation when the value of the shutdown speed 51 is switched will be explained. When the car 8 is in the intermediate portion inside the hoistway 1, all of the lower portion position switches 18a through 18c and the upper portion position switches 19a through 19c stop detecting the cam 17. At this point, electric power is supplied to the electromagnet 47, displacing the overspeed detecting switch 25 to the second detecting position. The value of the shutdown speed 51 is thereby set to the second reference value.

[0046] When the car 8 moves and enters either the upper end portion region or the lower end portion region from the intermediate portion of the hoistway 1, either the lower portion position switches 18a through 18c or the upper portion position switches 19a through 19c detect the cam 17. Supply of electric power to the electromagnet 47 is thereby stopped, displacing the overspeed detecting switch 25 to the first detecting position from the second detecting position. The value of the shutdown speed 51 is switched over to the first reference value by the displacement of the overspeed detecting switch 25 to the first detecting position.

[0047] When the car 8 enters the intermediate portion of the hoistway 1 from either the upper end portion region or the lower end portion region, the value of the shutdown speed 51 is switched over from the first reference value to the second reference value by a reverse operation to the above.

[0048] In an elevator apparatus of this kind, because presence or absence of a car 8 in a lower end portion region or an upper end portion region is detected by the presence or absence of detection of a cam 17 by lower portion position switches 18a through 18c or upper portion position switches 19a through 19c that are each disposed inside the hoistway 1, and a value of a shutdown speed 51 that constitutes a criterion for determining whether or not speed of the car 8 is abnormal is switched over based on the presence or absence of the car 8 in the lower end portion region or the upper end portion region, the value of the shutdown speed can be set lower than a rated speed when the car 8 is in the lower end portion region or the upper end portion region. Consequently, elevator operation can be stopped at a stage when the speed of the car 8 is lower than the rated speed at positions close to terminal portions of the hoistway 1. Deceleration distance of the car 8 can thereby be shortened, enabling size reductions of the car buffer 21 and the counterweight buffer 22 to be achieved. Reductions in height dimensions of the hoistway 1 can also be achieved. In addition, by installing the lower portion position switches 18a through 18c and the upper portion position switches 19a through 19c inside the hoistway 1, because it is no longer necessary to adjust a relationship between position of the car 8 and amount of movement of the car 8 inside the hoistway 1 for each hoistway 1, elevator apparatuses can be installed easily simply by adjusting the positions and number of lower portion position switches and upper portion position switches, even if each hoistway 1 has a different height.

[0049] Because the length of the cam 17 is longer than spacing between the lower portion position switches 18a through 18c and spacing between the upper portion position switches 19a through 19c, the lower portion position switches 18a through 18c and the upper portion position switches 19a through 19c can be prevented from all being unable to detect the cam 17 when the car 8 is in the upper end portion region or the lower end portion region. The presence or absence of the car 8 in the lower end portion region or the upper end portion region can thereby be detected more reliably.

[0050] Moreover, in the above example, the first reference value V_os1 is set so as to be lower than the rated speed value V₀, but the first reference value V_os1 may also be set so as to be greater than the rated speed value V₀.

Claims

1. An elevator apparatus characterized in comprising:

a car on which a detected body is disposed, and that is moved inside a hoistway;

a car position detecting apparatus that has a position switch that is disposed inside the hoistway and that can detect the detected body, the car position detecting apparatus detecting presence or absence of the car in a predetermined region that is positioned in a terminal portion of the hoistway by presence or absence of detection of the detected body by the position switch;

a speed governor sheave that is rotated together with movement of the car;

a sheave interlocking device that has a displacing body that can be displaced in response to rotational speed of the speed governor sheave;

an overspeed detecting switch that is displaceable between a first detecting position at which the displacing body is detected when a speed value of the car is a predetermined first reference value, and a second detecting position at which the displacing body is detected when the speed value of the car is a second reference value that is higher than the first reference value;

an electromagnetic displacing apparatus that displaces the overspeed detecting switch to the first detecting position when the car is in the predetermined region, and displaces the overspeed detecting switch to the second detecting position when the car is outside the predetermined region, based on information from the car position detecting apparatus; and

a control apparatus that controls elevator operation based on information from the overspeed detecting switch.

2. An elevator apparatus according to Claim 1, characterized in that:

the car position detecting apparatus comprises a plurality of the position switches that are disposed so as to be spaced apart from each other in a direction of movement of the car; and

a length of the detected body parallel to the direction of movement of the car is longer than a spacing between the position switches.

Drawing