EP2474498A1 - Elevator apparatus - Google Patents

Elevator apparatus Download PDF

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Publication number
EP2474498A1
EP2474498A1 EP09848963A EP09848963A EP2474498A1 EP 2474498 A1 EP2474498 A1 EP 2474498A1 EP 09848963 A EP09848963 A EP 09848963A EP 09848963 A EP09848963 A EP 09848963A EP 2474498 A1 EP2474498 A1 EP 2474498A1
Authority
EP
European Patent Office
Prior art keywords
car
end portion
extensible
portion region
speed
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP09848963A
Other languages
German (de)
French (fr)
Inventor
Mineo Okada
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Publication of EP2474498A1 publication Critical patent/EP2474498A1/en
Withdrawn legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
    • B66B5/00—Applications of checking, fault-correcting, or safety devices in elevators
    • B66B5/02—Applications of checking, fault-correcting, or safety devices in elevators responsive to abnormal operating conditions
    • B66B5/04—Applications of checking, fault-correcting, or safety devices in elevators responsive to abnormal operating conditions for detecting excessive speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66B—ELEVATORS; ESCALATORS OR MOVING WALKWAYS
    • B66B5/00—Applications of checking, fault-correcting, or safety devices in elevators
    • B66B5/02—Applications of checking, fault-correcting, or safety devices in elevators responsive to abnormal operating conditions
    • B66B5/04—Applications of checking, fault-correcting, or safety devices in elevators responsive to abnormal operating conditions for detecting excessive speed
    • B66B5/044—Mechanical overspeed governors

Definitions

  • the present invention relates to an elevator apparatus that has a car that is moved inside a hoistway.
  • elevator apparatuses have been proposed that activate a safety apparatus if a car speed exceeds a predetermined set speed ln 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 above set speed is changed in response to the car position.
  • the set speed is lowered as the car position approaches terminal portions of the hoistway.
  • 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.
  • 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; and a speed governor including: a centrifugal weight that revolves around a predetermined revolving shaft in response to the movement of the car; an extensible body that is connected to the centrifugal weight, and that is rotated around the revolving shaft and displaced relative to the revolving shaft in response to a centrifugal force to which the centrifugal weight is subjected due to the revolution; and a switching apparatus that extends and retracts the extensible body to set a length of the extensible
  • the length of the extensible body is set so as to be different lengths when the car is in either the upper end portion region or the lower end portion region and when the car is outside both the upper end portion region and the lower end portion region, the relationship between the amount of displacement of the extensible body relative to the revolving shaft and the speed of the car can be changed.
  • the value of the preset overspeed when the car is in either the upper end portion region or the lower end portion region can be lowered compared to when the car is in an intermediate portion of the hoistway.
  • the car can be stopped forcibly at a stage when the speed of the car is lower at positions close to terminal portions of the hoistway than when the car is in the intermediate portion of the hoistway, enabling the deceleration distance of the car to be shortened. Consequently, size reductions in the car buffer and the counterweight buffer can be achieved, enabling reductions in height dimensions of the hoistway.
  • FIG. 1 is a configuration diagram that shows an elevator apparatus according to Embodiment 1 of the present invention.
  • a machine room 2 is disposed in an upper portion of a hoistway 1.
  • a hoisting machine (a driving machine) 4 that has a driving sheave 3; a deflecting sheave 5 that is disposed so as to be positioned at a distance from the driving sheave 3; and a controlling apparatus 6 that controls elevator operation.
  • a main rope 7 is wound around the driving sheave 3 and the deflecting sheave 5.
  • a car 8 and a counterweight 9 that are 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 the hoistway 1 by rotation of the driving sheave 3.
  • 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).
  • An emergency stopper apparatus 10 that stops failing 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 by operation of the operating arm 11. Falling of the car 8 is stopped by gripping of the car guide rails by the emergency stopper apparatus 10.
  • a speed governor 12 is disposed inside the machine room 2, and a tensioning 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 tensioning 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 the movement of the car 8.
  • the speed governor main body 14 is able to grip the speed governor rope 16.
  • the operating arm 11 is operated by the speed governor rope 16 being gripped by the speed governor main body 14 and the car 8 being displaced relative to the speed governor rope 16.
  • 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.
  • 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.
  • 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.
  • 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.
  • 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.
  • Respective spacing B between the lower portion position switches 18a through 18c and between the upper portion position switches 19a through 19c is narrower than a length A of the cam 17.
  • 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.
  • the electric wires 20 are connected to a communications device 21 that is disposed inside the machine room 2.
  • the communications device 21 performs information communication with the speed governor main body 14 by radio based on the respective detection states of each of the lower portion position switches 18a through 18c and each of the upper portion position switches 19a through 19c.
  • a car buffer 22 that is positioned below the car 8, and a counterweight buffer 23 that is positioned below the counterweight 9 are disposed in a bottom portion (a pit portion) of the hoistway 1.
  • the car buffer 22 relieves mechanical shock that is imparted to the car 8.
  • the counterweight buffer 23 relieves mechanical shock that is imparted to the counterweight 9.
  • Figure 2 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 communications device 21 from Figure 1 .
  • Figure 3 is a circuit diagram that shows a state in which all of the lower portion position switches 18a through 18c and the upper portion position switches 19a through 19c from Figure 2 have stopped cam detection.
  • Figure 2 is a diagram that shows a state in which only two lower portion position switches 18a and 18b are detecting the cam 17.
  • 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 cose when detection of the cam 17 stops.
  • the radio signal is output from the communications device 21 to the speed governor main body 14 ( Figure 3 ), and when the car 8 is outside both the upper end portion region and the lower end portion region, the output of the radio signal from the communications device 21 is stopped ( Figure 2 ).
  • Figure 4 is a longitudinal cross section that shows the speed governor 12 from Figure 1 .
  • Figure 5 is a longitudinal cross section that shows the speed governor 12 when the car 8 from Figure 1 is outside both the lower end portion region and the upper end portion region.
  • Figure 6 is a front elevation that shows the speed governor 12 from Figure 1 . ln the figures, the speed governor 12 is supported by a supporting body 24.
  • the speed governor main body 14 has: a sheave interlocking device 25 that operates interdependently with the speed governor sheave 15 in response to rotational speed of the speed governor sheave 15; a stopping switch (an overspeed detecting switch) 26 that outputs a stopping signal that stops elevator operation when activated by the sheave interlocking device 25; and a gripping apparatus 27 that grips the speed governor rope 16 when activated by the sheave interlocking device 25 ( Figure 6 ).
  • a sheave shaft 28 of the speed governor sheave 15 is supported horizontally in the supporting body 24 by means of bearings 29.
  • a driving bevel gear 30 is fixed to an end portion of the sheave shaft 28.
  • the sheave interlocking device 25 has: a driven shaft (a predetermined revolving shaft) 31 that is disposed so as to be parallel to a vertical direction; a driven bevel gear 32 that is fixed to a lower end portion of the driven shaft 31, and that intermeshes with the driving bevel gear 30; a displacing body 33 that is disposed on the driven shaft 31, and that is displaceable relative to the driven shaft 31 in a direction that is parallel to the driven shaft 31; a centrifugally displacing apparatus 34 that displaces the displacing body 33 in response to the rotation of the driven shaft 31; and a switching apparatus 35 that can set the centrifugally displacing apparatus 34 such that a relationship between the rotational speed of the driven shaft 31 and the amount of displacement of the displacing body 33 is different when the car 8 is either in the upper end portion region or in the lower end portion region, and when the car 8 is outside both the upper end portion region and the lower end portion region.
  • a driven shaft a predetermined re
  • the driven shaft 31 is supported in the supporting body 24 by means of bearings 36. Rotation of the sheave shaft 28 is transmitted to the driven shaft 31 by means of the driving bevel gear 30 and the driven bevel gear 32. Consequently, the driven shaft 31 is rotated in response to the rotation of the speed governor sheave 15.
  • the centrifugally displacing apparatus 34 is disposed on an upper portion of the driven shaft 31.
  • the centrifugally displacing apparatus 34 is rotated together with the driven shaft 31.
  • the centrifugally displacing apparatus 34 has: a pair of fly balls (centrifugal weights) 37 that revolve around the driven shaft 31 in response to the rotation of the driven shaft 31; a pair of extensible bodies 38 that are connected to the fly balls 37, and that can rotate around the driven shaft 31; a sliding cylinder 39 that is passed slidably over the driven shaft 31; a pair of linking members 40 that link the respective extensible bodies 38 and the sliding cylinder 39; and a balancing spring 41 that forces the sliding cylinder 39 downward.
  • the fly balls 37 are subjected to centrifugal forces that correspond to the rotational speed of the driven shaft 31 by revolving around the driven shaft 31.
  • the extensible bodies 38 are displaced by pivoting relative to the driven shaft 31 in response to the centrifugal forces to which the fly balls 37 are subjected.
  • the sliding cylinder 39 is displaced in a direction that is parallel to the driven shaft 31 in response to the displacement of the respective extensible bodies 38 relative to the driven shaft 31.
  • the extensible bodies 38 are displaced in a direction in which the fly balls 37 move away from each other, and the sliding cylinder 39 is displaced upward in opposition to force from the balancing spring 41.
  • the rotational speed of the driven shaft 31 decreases, the extensible bodies 38 are displaced in a direction in which the fly balls 37 move toward each other, and the sliding cylinder 39 is displaced downward by the force from the balancing spring 41.
  • the respective extensible bodies 38 are constituted by rod-shaped bodies.
  • the extensible bodies 38 each have: an extensible body main body 42 that is mounted so as to be able to pivot relative to the driven shaft 31; and an actuator 43 that is disposed on the extensible body main body 42, and that changes the length of the extensible body 38.
  • the actuators 43 have: plungers 44 that are displaceable relative to the extensible body main bodies 42; and electromagnetic coils 45 that displace the plungers 44 relative to the extensible body main bodies 42.
  • the fly balls 37 are mounted to the plungers 44.
  • the plungers are displaceable between an extended position ( Figure 4 ) that is away from the extensible body main body 42; and a retracted position ( Figure 5 ) that is closer to the extensible body main body 42 than the extended position. Length of the extensible bodies 38 is changed by the plungers 44 being displaced between the extended position and the retracted position.
  • the plungers 44 are displaced to the extended position by passing electric current to the electromagnetic coils 45, and are displaced to the retracted position by forces from forcing bodies (not shown) when the passage of electric current to the electromagnetic coils 45 is stopped.
  • the displacing body 33 is displaceable together with the sliding cylinder 39.
  • the displacing body 33 is thereby displaced in a direction that is parallel to the driven shaft 31 in response to the rotational speed of the speed governor sheave 15.
  • the displacing body 33 is also rotatable relative to the sliding cylinder 39 and the driven shaft 31. Consequently, the displacing body 33 is not rotated even if the sliding cylinder 39 and the driven shaft 31 are rotated.
  • the displacing body 33 has: a driven cylinder 46 that is passed slidably over the driven shaft 31; and an operating portion 47 that protrudes outward from an outer circumferential surface of the driven cylinder 46.
  • the switching apparatus 35 extends and retracts the extensible bodies 38 to change the length of the extensible bodies 38 based on the information (the radio signal) from the communications device 21. Specifically, the switching apparatus 35 makes the length of the extensible bodies 38 different when the radio signal from the communications device 21 is received (i.e., when the car 8 is outside both the upper end portion region and the lower end portion region) and when the radio signal is not received (i.e., when the car 8 is in either the upper end portion region or the lower end portion region).
  • the orbital radius of the fly balls 37 is different, and thus the relationship between the rotational speed of the driven shaft 31 and the amount of displacement of the displacing body 33 is different, when the car 8 is either in the upper end portion region or in the lower end portion region, and when the car 8 is outside both the upper end portion region and the lower end portion region.
  • the switching apparatus 35 extends the length of the extensible bodies 38 when the car 8 is in either the upper end portion region or the lower end portion region, and shortens the length of the extensible bodies 38 when the car 8 is outside both the upper end portion region and the lower end portion region.
  • the switching apparatus 35 has: a generator 48 that generates electric power from the rotation of the driven shaft 31; and a switching circuit 49 that controls the electric power that is sent from the generator 48 to the electromagnetic coils 45 based on the information from the communications device 21.
  • the generator 48 is disposed on an upper end portion of the driven shaft 31.
  • the generator 48 is a direct-current generator.
  • the generator 48 has: a generator fixed shaft 50 that includes permanent magnets; and a generator main body 51 that includes a power generating coil, and that surrounds the generator fixed shaft 50.
  • the generator fixed shaft 50 is mounted to the supporting body 24 by means of a mounting bracket 52.
  • the generator main body 51 is rotated together with the driven shaft 31. Electric current that corresponds to the rotation of the driven shaft 31 arises in the power generating coil when the generator main body 51 is rotated together with the driven shaft 31.
  • the switching circuit 49 is electrically connected to the generator main body 51 and the electromagnetic coils 45 by conducting wires 53 and 54, respectively. Of the electric power that is generated by the generator 48, the switching circuit 49 only sends electric power to the electromagnetic coils 45 either when the car 8 is in either the upper end portion region or the lower end portion region, or when the car 8 is outside both the upper end portion region and the lower end portion region.
  • the electric current from the generator 48 is only sent to the electromagnetic coils 45 by the switching circuit 49 when the car 8 is outside both the upper end portion region and the lower end portion region (i.e., when the radio signal is received from the communications device 21). Consequently, the length of the extensible bodies 38 is lengthened when the car 8 is in either the upper end portion region or the lower end portion region, and the length of the extensible bodies 38 is shortened when the car 8 is outside both the upper end portion region and the lower end portion region.
  • the stopping switch 26 is disposed radially outside the driven cylinder 46.
  • the stopping switch 26 has: a switch main body 55 that is fixed to the supporting body 24; and a switch lever 56 that is disposed on the switch main body 55, and that projects toward the displacing body 33.
  • the operating portion 47 is able to operate the switch lever 56 by displacement of the displacing body 33 relative to the stopping switch 26.
  • the stopping switch 26 detects abnormality in the speed of the car 8 when the switch lever 56 is operated by the operating portion 47. Specifically, the stopping switch 26 detects the presence or absence of an abnormality in the speed of the car 8 based on the presence or absence of detection of the displacing body 33.
  • a stopping signal that stops elevator operation is output from the switch main body 55 on detection of an abnormality in the speed of the car 8 by the stopping switch 26.
  • the displacement of the displacing body 33 is greater than when the length of the extensible bodies 38 is short. Consequently, when the length of the extensible bodies 38 is long, the displacing body 33 will reach the position at which the switch lever 56 is operated at a stage when the rotational speed of the driven shaft 31 is lower than when the length of the extensible bodies 38 is short.
  • the speed of the car 8 at which the stopping switch 26 detects abnormality is a value that is lower when the length of the extensible bodies 38 is long (when the car 8 is in either the upper end portion region or the lower end portion region) than when the length of the extensible bodies 38 is short (when the car 8 is outside both the upper end portion region and the lower end portion region).
  • the controlling apparatus 6 controls elevator operation based on information from the stopping switch 26. ln this example, when the stopping signal is received from the stopping switch 26, the controlling apparatus 6 determines that an abnormality has arisen in the speed of the car 8, and performs control that stops elevator operation.
  • the gripping apparatus 27 is disposed below the speed governor sheave 15 as shown in Figure 6 .
  • the gripping apparatus 27 has: a fixed shoe 57 that is fixed to the supporting body 24; a movable shoe 58 that is displaceable between a gripping position that grips the speed governor rope 16 against the fixed shoe 57 and an open position that is further away from the fixed shoe 57 than the gripping position; a displacing pressing apparatus 59 that generates a gripping force that grips the speed governor rope 16 between the movable shoe 58 that has been displaced to the gripping position and the fixed shoe 57; and a holding apparatus 60 that holds the movable shoe 58 in the open position during normal operation, and that releases holding of the movable shoe 58 when the speed of the car 8 reaches a second preset overspeed that is higher than the first set overspeed.
  • the displacing pressing apparatus 59 has: a shoe extensible arm 61 that is connected between the mount portion that is disposed on the supporting body 24 and the movable shoe 58, and that can be extended and retracted; and a compressed spring (a forcing body) 62 that is disposed on the shoe extensible arm 61, and that forces the movable shoe 58 away from the mount portion of the supporting body 24.
  • the shoe extensible arm 61 is pivotably connected to both the mount portion of the supporting body 24 and the movable shoe 58.
  • the movable shoe 58 is displaced between the gripping position and the open position by the shoe extensible arm 61 being pivoted relative to the mount portion of the supporting body 24.
  • the shoe extensible arm 61 is pushed against the fixed shoe 57 and compressed when the movable shoe 58 is displaced to the gripping position.
  • the shoe extensible arm 61 is subjected to the force of the compressed spring 62 and extended when the movable shoe 58 is displaced to the open position.
  • the compressed spring 62 is compressed between the mount portion of the supporting body 24 and the movable shoe 58.
  • the compressed spring 62 is a coil spring through which the shoe extensible arm 61 has been passed internally. The force from the compressed spring 62 increases as the shoe extensible arm 61 is compressed.
  • a gripping force from the displacing pressing apparatus 59 arises due to the movable shoe 58 being displaced toward the gripping position and the force from the compressed spring 62 increasing.
  • the holding apparatus 60 has: an engaging lever 63 that is displaceable between an engaged position that engages with the movable shoe 58 and a released position in which engagement with the movable shoe 58 is disengaged; a releasing spring (a forcing body) 64 that forces the engaging lever 63 in such a direction as to be displaced toward the released position; and a restraining member 65 that holds the engaging lever 63 in the engaged position in opposition to the force from the releasing spring 64.
  • the engaging lever 63 is displaced between the engaged position and the released position by being pivoted around a lever shaft 66 that is disposed on the supporting body 24.
  • the releasing spring 64 is connected between the engaging lever 63 and the supporting body 24.
  • the restraining member 65 is pivotable around a supporting shaft 67 that is disposed on the supporting body 24.
  • the restraining member 65 is linked to the displacing body 33 by means of a link 68.
  • the restraining member 65 is thereby pivoted around the supporting shaft 67 in response to the displacement of the displacing body 33.
  • the link 68 is pivotably connected to both the displacing body 33 and the restraining member 65.
  • the link 68 is displaced upward by an increase in the rotational speed of the driven shaft 31.
  • the engaging lever 63 is held in the engaged position by the restraining member 65 during normal operation.
  • the restraining member 65 is pivoted by upward displacement of the link 68 in a direction in which holding of the engaging lever 63 by the restraining member 65 is disengaged. Holding of the engaging lever 63 by the restraining member 65 is disengaged when the speed of the car 8 exceeds the first set overspeed and reaches a second set overspeed.
  • Figure 7 is a graph that shows relationships between normal operating speed, a first set overspeed, and a second set overspeed, respectively, of the car 8 from Figure 1 and position of the car 8.
  • the value of the first set overspeed 72 (the speed of the car 8 when the stopping switch 26 outputs the stopping signal) is a value that is higher than the normal operating speed 71 of the car 8 at all positions to which the car 8 moves.
  • the value of the second set overspeed 73 (the speed of the car 8 when the emergency stopper apparatus 10 is activated due to gripping of the speed governor rope 16 by the speed governor main body 14) is a value that is higher than the value of the first set overspeed 72 at all positions through which the car 8 moves.
  • the value of the first set overspeed 72 is a first terminal portion reference value V os' that is lower than a rated speed value V 0 of the elevator when the car 8 is in either the upper end portion region or the lower end portion region, and is a first intermediate portion reference value V os that is higher than the rated speed value V 0 of the elevator (a value that is 1.3 times the rated speed, for example) when the car 8 is outside both the upper end portion region and the lower end portion region.
  • the value of the second set overspeed 73 is a second terminal portion reference value V tr' that is lower than the rated speed value V 0 of the elevator and higher than the first terminal portion reference value V os' when the car 8 is in either the upper end portion region or the lower end portion region, and is a second intermediate portion reference value V tr that is higher than the first intermediate portion reference value V os when the car 8 is outside both the upper end portion region and the lower end portion region.
  • a stopping signal is sent to the control apparatus 6 from the stopping switch 26.
  • the control apparatus 6 receives the stopping signal, elevator operation is stopped forcibly by the control apparatus 6.
  • each of the extensible bodies 38 contracts, and the length of each of the extensible bodies 38 is shortened.
  • the orbital radius of the fly balls 37 is thereby reduced, setting the value of the first set overspeed 72 to the first intermediate portion reference value V os , and setting the value of the second set overspeed 73 to the second intermediate portion reference value V tr .
  • each of the extensible bodies 38 extends, increasing the length of each of the extensible bodies 38.
  • the orbital radius of the fly balls 37 is thereby increased, switching the value of the first set overspeed 72 over to the first terminal portion reference value V os' , which is lower than the first intermediate portion reference value V os , and switching the value of the second set overspeed 73 over to the second terminal portion reference value V tr' , which is lower than the second intermediate portion reference value V tr .
  • the value of the first set overspeed 72 is switched over from the first terminal portion reference value V os' to the first intermediate portion reference value V os
  • the value of the second set overspeed 73 is switched over from the second terminal portion reference value V t r' to the second intermediate portion reference value V tr by a reverse operation to the above,
  • the length of the extensible bodies 38 is set so as to be different lengths when the car 8 is in either the upper end portion region or the lower end portion region, and when the car 8 is outside both the upper end portion region and the lower end portion region, the relationship between the amount of displacement of the extensible bodies 38 relative to the driven shaft 31 and the rotational speed of the driven shaft 31 can be changed.
  • the respective values of the first and second preset overspeeds 72 and 73 when the car 8 is in either the upper end portion region or the lower end portion region can be lowered compared to when the car 8 is in the intermediate portion of the hoistway 1.
  • the car 8 can be stopped forcibly at a stage when the speed of the car 8 is lower at positions close to terminal portions of the hoistway 1 than when the car 8 is in the intermediate portion of the hoistway 1, enabling the deceleration distance of the car 8 to be shortened. Consequently, size reductions in the car buffer 22 and the counterweight buffer 23 can be achieved, enabling reductions in height dimensions of the 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.
  • the switching apparatus 35 has: a generator 48 that generates electric power from the rotation of the driven shaft 31; and a switching circuit 49 that only sends electric power that is generated by the generator 48 to the electromagnetic coils 45 either when the car 8 is in either the upper end portion region or the lower end portion region, or when the car 8 is outside both the upper end portion region and the lower end portion region, the need to supply power separately from outside to change the length of the extensible bodies 38 can be eliminated.
  • the lower portion position switches 18a through 18c and the spacing between the upper portion position switches 19a through 19c is narrower than the length of the cam 17, 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 either the upper end portion region or the lower end portion region. The presence or absence of the car 8 in the upper end portion region or the lower end portion region can thereby be detected more reliably.
  • information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region is sent to the switching circuit 49 using the radio signal from the communications device 21, but information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region may also be sent to the switching circuit 49 using a cable.
  • two brushes are connected to a first end portion and a second end portion of the electric wire 20 instead of the communications device 21, and two sliding portions that the respective brushes contact are disposed on the driven shaft 31.
  • the respective sliding portions are electrically connected to the switching circuit 49.
  • the information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region is sent to the switching circuit 49 through the respective brushes and the respective sliding portions.
  • FIG 8 is a partially cutaway front elevation that shows a speed governor of an elevator apparatus according to Embodiment 2 of the present invention.
  • Figure 9 is a cross section that is taken along line IX - lX in Figure 8 .
  • a supporting body 24 is made of a member that has a U-shaped cross section that has a pair of facing walls that face each other.
  • a bearing 29 is mounted separately to each of the facing walls of the supporting body 24.
  • a sheave shaft (a predetermined revolving shaft) 28 of a speed governor sheave 15 is supported by the supporting body 24 by means of each of the bearings 29. The speed governor sheave 15 and the sheave shaft 28 are rotated together in response to movement of a car 8.
  • the centrifugal weights 81 are subjected to centrifugal forces that correspond to the rotational speed of the sheave shaft 28 by revolving around the sheave shaft 28.
  • the extensible bodies 82 are displaced relative to the sheave shaft 28 by pivoting around the pins 83 in response to the centrifugal forces to which the centrifugal weights 81 are subjected.
  • the extensible bodies 82 are thereby displaced relative to the sheave shaft 28 in directions in which the centrifugal weights 81 move away from the sheave shaft 28 if the rotational speed of the sheave shaft 28 increases, and the extensible bodies 82 are displaced relative to the sheave shaft 28 toward the sheave shaft 28 if the rotational speed of the sheave shaft 28 decreases.
  • the extensible bodies 82 have: first and second pivoting weight portions (extensible body main bodies) 84 that are pivotable around the pins 83 that are disposed on the speed governor sheave 15; and actuators 85 that are disposed on the pivoting weight portions 84, and that change the length of the extensible bodies 82.
  • the respective pivoting weight portions 84 are linked to each other by means of linking members 86.
  • the actuators 85 have a similar configuration to the actuators 43 according to Embodiment 1, and have a plunger and an electromagnetic coil.
  • the actuators 85 are disposed in a radial direction of the speed governor sheave 15.
  • the centrifugal weights 81 are mounted to the plungers of the actuators 85.
  • the centrifugal weights 81 are disposed radially further outward on the speed governor sheave 15 than the pivoting weight portions 84.
  • the length of the extensible bodies 82 changes when the plunger of the actuators 85 are displaced between an extended position and a retracted position.
  • the length of the extensible bodies 82 is shortened when an electric current is passed to the electromagnetic coils of the actuators 85, and is lengthened by forcing bodies (not shown) when the passage of electric current to the electromagnetic coils of the actuators 85 is stopped.
  • the centrifugal weights 81 are displaced away from the sheave shaft 28 relative to the pivoting weight portions 84 when the length of the extensible bodies 82 is extended, and are displaced relative to the pivoting weight portions 84 toward the sheave shaft 28 when the length of the extensible bodies 82 is shortened.
  • a balancing spring 87 that opposes the centrifugal forces to which the centrifugal weights 81 are subjected is disposed between a first end portion of the first pivoting weight portion 84 and the speed governor sheave 15.
  • An operating portion (in this example, a bolt) 88 is fixed to a second end portion of the first pivoting weight portion 84. The operating portion 88 is displaced away from the sheave shaft 28 when the rotational speed of the sheave shaft 28 increases, and is displaced toward the sheave shaft 28 when the rotational speed of the sheave shaft 28 decreases.
  • An engaging hook 89 is disposed on the first pivoting weight portion 84. The engaging hook 89 is displaced toward the sheave shaft 28 when the rotational speed of the sheave shaft 28 increases, and is displaced away from the sheave shaft 28 when the rotational speed of the sheave shaft 28 decreases.
  • a switching apparatus 90 that changes the length of the extensible bodies 82 based on information (a radio signal) from a communications device 21 is disposed on the sheave shaft 28.
  • the switching apparatus 90 makes the length of extensible bodies 82 different when the radio signal from the communications device 21 is received (i.e., when the car 8 is outside both the upper end portion region and the lower end portion region), and when the radio signal is not received (i.e., when the car 8 is in either the upper end portion region or the lower end portion region).
  • the switching apparatus 90 extends the length of the extensible bodies 82 when the car 8 is in either the upper end portion region or the lower end portion region, and shortens the length of the extensible bodies 82 when the car 8 is outside both the upper end portion region and the lower end portion region.
  • the switching apparatus 90 has: a generator 91 that generates electric power from the rotation of the sheave shaft 28; and a switching circuit 92 that controls the electric power that is sent from the generator 91 to the electromagnetic coils of the actuators 85 based on the information from the communications device 21.
  • the generator 91 has: an annular generator fixed portion 93 that includes permanent magnets; and an annular generator main body 94 that includes a power generating coil, and that surrounds the generator fixed portion 93.
  • the generator fixed portion 93 is fixed to the supporting body 24.
  • the generator fixed portion 93 surrounds the sheave shaft 28 so as to have a clearance interposed.
  • the generator main body 94 is fixed to the speed governor sheave 15, and is rotated together with the speed governor sheave 15 and the sheave shaft 28. An electric current that corresponds to the rotation of the speed governor sheave 15 and the sheave shaft 28 arises in the power generating coil when the generator main body 94 is rotated.
  • the switching circuit 92 is fixed to the generator main body 94. Consequently, the switching circuit 92 is rotated together with the speed governor sheave 15 and the sheave shaft 28.
  • the switching circuit 92 is electrically connected to the electromagnetic coils of the actuators 85 and to the generator main body 94 by respective conducting wires 95.
  • the switching circuit 92 has a similar configuration to the switching circuit 49 according to Embodiment 1. Consequently, in this example, the electric current from the generator 91 is only sent to the electromagnetic coils of the actuators 85 by the switching circuit 92 when the car 8 is outside both the upper end portion region and the lower end portion region (i.e., when the radio signal is received from the communications device 21).
  • a stopping switch (an overspeed detecting switch) 96 is mounted to the supporting body 24, as shown in Figure 8 .
  • the stopping switch 96 has a similar configuration to the stopping switch 26 according to Embodiment 1, and has a switch main body 55 and a switch lever 56.
  • the operating portion 88 is able to operate the switch lever 56 by displacement of the pivoting weight portions 84 relative to the sheave shaft 28.
  • the stopping switch 96 detects abnormality in the speed of the car 8 when the switch lever 56 is operated by the operating portion 88.
  • a stopping signal that stops elevator operation is output from the switch main body 55 on detection of an abnormality in the speed of the car 8 by the stopping switch 96.
  • the speed of the car 8 at which the stopping switch 96 detects abnormality in the speed of the car 8 is a value that is lower when the length of the extensible bodies 82 is long (when the car 8 is in either the upper end portion region or the lower end portion region) than when the length of the extensible bodies 82 is short (when the car 8 is outside both the upper end portion region and the lower end portion region) due to the difference in the orbital radius of the centrifugal weights 81.
  • a ratchet wheel 97 that is rotatable around the sheave shaft 28 is supported by the supporting body 24.
  • a plurality of teeth are disposed on an outer circumferential portion of the ratchet wheel 97.
  • the ratchet wheel 97 is able to rotate independently from the speed governor sheave 15.
  • the engaging hook 89 is displaced toward the outer circumferential portion of the ratchet wheel 97 as the rotational speed of the sheave shaft 28 increases.
  • the engaging hook 89 engages with the outer circumferential portion of the ratchet wheel 97 when the speed of the car 8 reaches a second set overspeed that is higher than a first set overspeed.
  • An arm 98 is disposed pivotably on the supporting body 24.
  • a shoe (a braking segment) 99 that is pressed onto the speed governor sheave 15 so as to have the speed governor rope 16 interposed is disposed pivotably on an intermediate portion of the arm 98.
  • a spring shaft 100 is passed through a leading end portion of the arm 98.
  • An actuating lever 101 is connected between a first end portion of the spring shaft 100 and the ratchet wheel 97.
  • a spring bearing member 102 and a nut 103 that prevents the spring bearing member 102 from disengaging from the spring shaft 100 are disposed on a second end portion of the spring shaft 100.
  • a compressed spring 104 for generating a gripping force that grips the speed governor rope 16 is disposed between the leading end portion of the arm 98 and the spring bearing member 102.
  • a gripping apparatus that grips the speed governor rope 16 includes the ratchet wheel 97, the arm 98, the shoe 99, the spring shaft 100, the actuating lever 101, the spring bearing member 102, the nut 103, and the compressed spring 104.
  • the speed governor rope 16 is gripped between the speed governor sheave 15 and the shoe 99 when the shoe 99 is pressed onto the speed governor sheave 15 so as to have the speed governor rope 16 interposed.
  • the rest of the configuration is similar to that of Embodiment 1.
  • the values of the first and second preset overspeeds are switched over by changing the length of the extensible bodies 82.
  • the operation when switching the values of the first and second preset overspeeds over is similar to that of Embodiment 1.
  • the switch lever 56 is operated by the operating portion 88, and a stopping signal is sent to the control apparatus 6 from the stopping switch 96.
  • a stopping signal is sent to the control apparatus 6 from the stopping switch 96.
  • information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region is sent to the switching circuit 92 using the radio signal from the communications device 21, but information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region may also be sent to the switching circuit 92 using a cable.
  • two brushes are connected to a first end portion and a second end portion of the electric wire 20 instead of the communications device 21, and two sliding portions that the respective brushes contact are disposed on the sheave shaft 28.
  • the respective sliding portions are electrically connected to the switching circuit 92.
  • the information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region is sent to the switching circuit 92 through the respective brushes and the respective sliding portions.
  • electric power that is generated by the generator is sent to the electromagnetic coils, but electric power that is supplied from a commercial power supply, or a battery, etc., may also be sent to the electromagnetic coils, for example.
  • the respective values of the first and second preset overspeeds 72 and 73 when the car 8 is in either the upper end portion region or the lower end portion region are values that are lower than the rated speed value V 0 of the elevator, but the value of only the second set overspeed 73 when the car 8 is in either the upper end portion region or the lower end portion region may be a value that is higher than the rated speed value V 0 of the elevator, or the respective values of the first and second preset overspeeds 72 and 73 may both be values that are higher than the rated speed value V 0 of the elevator.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Maintenance And Inspection Apparatuses For Elevators (AREA)

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 speed governor includes: a centrifugal weight that revolves around a predetermined revolving shaft in response to the movement of the car; an extensible body that is connected to the centrifugal weight, and that is displaced relative to the revolving shaft in response to a centrifugal force to which the centrifugal weight is subjected due to the revolution; and a switching apparatus that extends and retracts the extensible body to set a length of the extensible body to different lengths when the car is inside the predetermined region and when the car is outside the predetermined region. The speed governor detects presence or absence of an abnormality in a speed of the car based on the displacement of the extensible body relative to the revolving shaft.

Description

    TECHNICAL FIELD
  • The present invention relates to an elevator apparatus that has a car that is moved inside a hoistway.
    • BACKGROUND ART
  • Conventionally, elevator apparatuses have been proposed that activate a safety apparatus if a car speed exceeds a predetermined set speed ln 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 above set speed 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).
    • CITATION LIST PATENT LITERATURE
    • [Patent Literature 1]
      Japanese Patent Laid-Open No. 2003-14646 (Gazette)
    SUMMARY OF THE INVENTION PROBLEM TO BE SOLVED BY THE INVENTION
  • 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.
  • 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
  • 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; and a speed governor including: a centrifugal weight that revolves around a predetermined revolving shaft in response to the movement of the car; an extensible body that is connected to the centrifugal weight, and that is rotated around the revolving shaft and displaced relative to the revolving shaft in response to a centrifugal force to which the centrifugal weight is subjected due to the revolution; and a switching apparatus that extends and retracts the extensible body to set a length of the extensible body to different lengths when the car is inside the predetermined region and when the car is outside the predetermined region, the speed governor detecting presence or absence of an abnormality in a speed of the car based on the displacement of the extensible body relative to the revolving shaft.
    • EFFECTS OF THE INVENTION
  • In an elevator apparatus according to the present invention, because the length of the extensible body is set so as to be different lengths when the car is in either the upper end portion region or the lower end portion region and when the car is outside both the upper end portion region and the lower end portion region, the relationship between the amount of displacement of the extensible body relative to the revolving shaft and the speed of the car can be changed. Thus, the value of the preset overspeed when the car is in either the upper end portion region or the lower end portion region can be lowered compared to when the car is in an intermediate portion of the hoistway. In other words, the car can be stopped forcibly at a stage when the speed of the car is lower at positions close to terminal portions of the hoistway than when the car is in the intermediate portion of the hoistway, enabling the deceleration distance of the car to be shortened. Consequently, size reductions in the car buffer and the counterweight buffer can be achieved, enabling reductions in height dimensions of the hoistway. By installing the lower portion position switches and the upper portion position switches inside the hoistway, because it is no longer necessary to adjust the relationship between position of the car and amount of movement of the car inside the hoistway for each hoistway, 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 has a different height.
    • BRIEF DESCRIPTION OF THE DRAWINGS
    • Figure 1 is a configuration diagram that shows an elevator apparatus according to Embodiment 1 of the present invention;
    • Figure 2 is a circuit diagram that shows electrically connected states of respective lower portion position switches, respective upper portion position switches, and a communications device from Figure 1;
    • Figure 3 is a circuit diagram that shows a state in which all of the respective lower portion position switches and the respective upper portion position switches from Figure 2 have stopped cam detection;
    • Figure 4 is a longitudinal cross section that shows a speed governor from Figure 1;
    • Figure 5 is a longitudinal cross section that shows the speed governor from Figure 1 when a car is outside both the lower end portion region and the upper end portion region;
    • Figure 6 is a front elevation that shows the speed governor from Figure 1;
    • Figure 7 is a graph that shows relationships between normal operating speed, a first set overspeed, and a second set overspeed, respectively, of the car from Figure 1 and position of the car;
    • Figure 8 is a partially cutaway front elevation that shows a speed governor of an elevator apparatus according to Embodiment 2 of the present invention; and
    • Figure 9 is a cross section that is taken along line IX - lX in Figure 8.
    DESCRIPTION OF EMBODIMENTS
  • Preferred embodiments of the present invention will now be explained with reference to the drawings.
    • Embodiment 1
  • Figure 1 is a configuration 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 driving sheave 3; a deflecting sheave 5 that is disposed so as to be positioned at a distance from the driving sheave 3; and a controlling apparatus 6 that controls elevator operation.
  • A main rope 7 is wound around the driving sheave 3 and the deflecting sheave 5. A car 8 and a counterweight 9 that are 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 the hoistway 1 by rotation of the driving 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).
  • An emergency stopper apparatus 10 that stops failing 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 by operation of the operating arm 11. Falling of the car 8 is stopped by gripping of the car guide rails by the emergency stopper apparatus 10.
  • A speed governor 12 is disposed inside the machine room 2, and a tensioning 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 tensioning 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 the movement of the car 8.
  • The speed governor main body 14 is able to grip the speed governor rope 16. The operating arm 11 is operated by the speed governor rope 16 being gripped by the speed governor main body 14 and the car 8 being displaced relative to the speed governor rope 16.
  • 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.
  • 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.
  • 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.
  • 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.
  • 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.
  • Respective spacing B between the lower portion position switches 18a through 18c and between the upper portion position switches 19a through 19c is narrower than a length A of the cam 17. 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.
  • 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. The electric wires 20 are connected to a communications device 21 that is disposed inside the machine room 2. The communications device 21 performs information communication with the speed governor main body 14 by radio based on the respective detection states of each of the lower portion position switches 18a through 18c and each of the upper portion position switches 19a through 19c.
  • A car buffer 22 that is positioned below the car 8, and a counterweight buffer 23 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 22 relieves mechanical shock that is imparted to the car 8. When subjected to a collision with the counterweight 9, the counterweight buffer 23 relieves mechanical shock that is imparted to the counterweight 9.
  • 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.
  • Figure 2 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 communications device 21 from Figure 1. Figure 3 is a circuit diagram that shows a state in which all of the lower portion position switches 18a through 18c and the upper portion position switches 19a through 19c from Figure 2 have stopped cam detection. Moreover, Figure 2 is a diagram that shows a state in which only two lower portion position switches 18a and 18b are detecting the cam 17.
  • In the figures, 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 cose when detection of the cam 17 stops.
  • 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 as shown in Figure 3, and a radio signal is output from the communications device 21 to the speed governor main body 14. 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 as shown in Figure 2, and the output of the radio signal from the communications device 21 is stopped.
  • In other words, when the car 8 is present in either the upper end portion region or the lower end portion region, the radio signal is output from the communications device 21 to the speed governor main body 14 (Figure 3), and when the car 8 is outside both the upper end portion region and the lower end portion region, the output of the radio signal from the communications device 21 is stopped (Figure 2).
  • Figure 4 is a longitudinal cross section that shows the speed governor 12 from Figure 1. Figure 5 is a longitudinal cross section that shows the speed governor 12 when the car 8 from Figure 1 is outside both the lower end portion region and the upper end portion region. In addition, Figure 6 is a front elevation that shows the speed governor 12 from Figure 1. ln the figures, the speed governor 12 is supported by a supporting body 24. The speed governor main body 14 has: a sheave interlocking device 25 that operates interdependently with the speed governor sheave 15 in response to rotational speed of the speed governor sheave 15; a stopping switch (an overspeed detecting switch) 26 that outputs a stopping signal that stops elevator operation when activated by the sheave interlocking device 25; and a gripping apparatus 27 that grips the speed governor rope 16 when activated by the sheave interlocking device 25 (Figure 6).
  • As shown in Figures 4 and 5, a sheave shaft 28 of the speed governor sheave 15 is supported horizontally in the supporting body 24 by means of bearings 29. A driving bevel gear 30 is fixed to an end portion of the sheave shaft 28.
  • The sheave interlocking device 25 has: a driven shaft (a predetermined revolving shaft) 31 that is disposed so as to be parallel to a vertical direction; a driven bevel gear 32 that is fixed to a lower end portion of the driven shaft 31, and that intermeshes with the driving bevel gear 30; a displacing body 33 that is disposed on the driven shaft 31, and that is displaceable relative to the driven shaft 31 in a direction that is parallel to the driven shaft 31; a centrifugally displacing apparatus 34 that displaces the displacing body 33 in response to the rotation of the driven shaft 31; and a switching apparatus 35 that can set the centrifugally displacing apparatus 34 such that a relationship between the rotational speed of the driven shaft 31 and the amount of displacement of the displacing body 33 is different when the car 8 is either in the upper end portion region or in the lower end portion region, and when the car 8 is outside both the upper end portion region and the lower end portion region.
  • The driven shaft 31 is supported in the supporting body 24 by means of bearings 36. Rotation of the sheave shaft 28 is transmitted to the driven shaft 31 by means of the driving bevel gear 30 and the driven bevel gear 32. Consequently, the driven shaft 31 is rotated in response to the rotation of the speed governor sheave 15.
  • The centrifugally displacing apparatus 34 is disposed on an upper portion of the driven shaft 31. The centrifugally displacing apparatus 34 is rotated together with the driven shaft 31. ln addition, the centrifugally displacing apparatus 34 has: a pair of fly balls (centrifugal weights) 37 that revolve around the driven shaft 31 in response to the rotation of the driven shaft 31; a pair of extensible bodies 38 that are connected to the fly balls 37, and that can rotate around the driven shaft 31; a sliding cylinder 39 that is passed slidably over the driven shaft 31; a pair of linking members 40 that link the respective extensible bodies 38 and the sliding cylinder 39; and a balancing spring 41 that forces the sliding cylinder 39 downward.
  • The fly balls 37 are subjected to centrifugal forces that correspond to the rotational speed of the driven shaft 31 by revolving around the driven shaft 31.
  • The extensible bodies 38 are displaced by pivoting relative to the driven shaft 31 in response to the centrifugal forces to which the fly balls 37 are subjected. The sliding cylinder 39 is displaced in a direction that is parallel to the driven shaft 31 in response to the displacement of the respective extensible bodies 38 relative to the driven shaft 31. Specifically, when the rotational speed of the driven shaft 31 increases, the extensible bodies 38 are displaced in a direction in which the fly balls 37 move away from each other, and the sliding cylinder 39 is displaced upward in opposition to force from the balancing spring 41. When the rotational speed of the driven shaft 31 decreases, the extensible bodies 38 are displaced in a direction in which the fly balls 37 move toward each other, and the sliding cylinder 39 is displaced downward by the force from the balancing spring 41.
  • The respective extensible bodies 38 are constituted by rod-shaped bodies. The extensible bodies 38 each have: an extensible body main body 42 that is mounted so as to be able to pivot relative to the driven shaft 31; and an actuator 43 that is disposed on the extensible body main body 42, and that changes the length of the extensible body 38.
  • The actuators 43 have: plungers 44 that are displaceable relative to the extensible body main bodies 42; and electromagnetic coils 45 that displace the plungers 44 relative to the extensible body main bodies 42.
  • The fly balls 37 are mounted to the plungers 44. The plungers are displaceable between an extended position (Figure 4) that is away from the extensible body main body 42; and a retracted position (Figure 5) that is closer to the extensible body main body 42 than the extended position. Length of the extensible bodies 38 is changed by the plungers 44 being displaced between the extended position and the retracted position. The plungers 44 are displaced to the extended position by passing electric current to the electromagnetic coils 45, and are displaced to the retracted position by forces from forcing bodies (not shown) when the passage of electric current to the electromagnetic coils 45 is stopped.
  • The displacing body 33 is displaceable together with the sliding cylinder 39. The displacing body 33 is thereby displaced in a direction that is parallel to the driven shaft 31 in response to the rotational speed of the speed governor sheave 15. The displacing body 33 is also rotatable relative to the sliding cylinder 39 and the driven shaft 31. Consequently, the displacing body 33 is not rotated even if the sliding cylinder 39 and the driven shaft 31 are rotated. In addition, the displacing body 33 has: a driven cylinder 46 that is passed slidably over the driven shaft 31; and an operating portion 47 that protrudes outward from an outer circumferential surface of the driven cylinder 46.
  • The switching apparatus 35 extends and retracts the extensible bodies 38 to change the length of the extensible bodies 38 based on the information (the radio signal) from the communications device 21. Specifically, the switching apparatus 35 makes the length of the extensible bodies 38 different when the radio signal from the communications device 21 is received (i.e., when the car 8 is outside both the upper end portion region and the lower end portion region) and when the radio signal is not received (i.e., when the car 8 is in either the upper end portion region or the lower end portion region). Thus, the orbital radius of the fly balls 37 is different, and thus the relationship between the rotational speed of the driven shaft 31 and the amount of displacement of the displacing body 33 is different, when the car 8 is either in the upper end portion region or in the lower end portion region, and when the car 8 is outside both the upper end portion region and the lower end portion region.
  • In this example, the switching apparatus 35 extends the length of the extensible bodies 38 when the car 8 is in either the upper end portion region or the lower end portion region, and shortens the length of the extensible bodies 38 when the car 8 is outside both the upper end portion region and the lower end portion region.
  • The switching apparatus 35 has: a generator 48 that generates electric power from the rotation of the driven shaft 31; and a switching circuit 49 that controls the electric power that is sent from the generator 48 to the electromagnetic coils 45 based on the information from the communications device 21.
  • The generator 48 is disposed on an upper end portion of the driven shaft 31. The generator 48 is a direct-current generator. In addition, the generator 48 has: a generator fixed shaft 50 that includes permanent magnets; and a generator main body 51 that includes a power generating coil, and that surrounds the generator fixed shaft 50. The generator fixed shaft 50 is mounted to the supporting body 24 by means of a mounting bracket 52. The generator main body 51 is rotated together with the driven shaft 31. Electric current that corresponds to the rotation of the driven shaft 31 arises in the power generating coil when the generator main body 51 is rotated together with the driven shaft 31.
  • The switching circuit 49 is electrically connected to the generator main body 51 and the electromagnetic coils 45 by conducting wires 53 and 54, respectively. Of the electric power that is generated by the generator 48, the switching circuit 49 only sends electric power to the electromagnetic coils 45 either when the car 8 is in either the upper end portion region or the lower end portion region, or when the car 8 is outside both the upper end portion region and the lower end portion region.
  • In this example, the electric current from the generator 48 is only sent to the electromagnetic coils 45 by the switching circuit 49 when the car 8 is outside both the upper end portion region and the lower end portion region (i.e., when the radio signal is received from the communications device 21). Consequently, the length of the extensible bodies 38 is lengthened when the car 8 is in either the upper end portion region or the lower end portion region, and the length of the extensible bodies 38 is shortened when the car 8 is outside both the upper end portion region and the lower end portion region.
  • The stopping switch 26 is disposed radially outside the driven cylinder 46. The stopping switch 26 has: a switch main body 55 that is fixed to the supporting body 24; and a switch lever 56 that is disposed on the switch main body 55, and that projects toward the displacing body 33. The operating portion 47 is able to operate the switch lever 56 by displacement of the displacing body 33 relative to the stopping switch 26. The stopping switch 26 detects abnormality in the speed of the car 8 when the switch lever 56 is operated by the operating portion 47. Specifically, the stopping switch 26 detects the presence or absence of an abnormality in the speed of the car 8 based on the presence or absence of detection of the displacing body 33. A stopping signal that stops elevator operation is output from the switch main body 55 on detection of an abnormality in the speed of the car 8 by the stopping switch 26.
  • Because the orbital radius of the fly balls 37 increases when the length of the extensible bodies 38 is long, the displacement of the displacing body 33 is greater than when the length of the extensible bodies 38 is short. Consequently, when the length of the extensible bodies 38 is long, the displacing body 33 will reach the position at which the switch lever 56 is operated at a stage when the rotational speed of the driven shaft 31 is lower than when the length of the extensible bodies 38 is short. In other words, the speed of the car 8 at which the stopping switch 26 detects abnormality (a first set overspeed) is a value that is lower when the length of the extensible bodies 38 is long (when the car 8 is in either the upper end portion region or the lower end portion region) than when the length of the extensible bodies 38 is short (when the car 8 is outside both the upper end portion region and the lower end portion region).
  • The controlling apparatus 6 controls elevator operation based on information from the stopping switch 26. ln this example, when the stopping signal is received from the stopping switch 26, the controlling apparatus 6 determines that an abnormality has arisen in the speed of the car 8, and performs control that stops elevator operation.
  • The gripping apparatus 27 is disposed below the speed governor sheave 15 as shown in Figure 6. The gripping apparatus 27 has: a fixed shoe 57 that is fixed to the supporting body 24; a movable shoe 58 that is displaceable between a gripping position that grips the speed governor rope 16 against the fixed shoe 57 and an open position that is further away from the fixed shoe 57 than the gripping position; a displacing pressing apparatus 59 that generates a gripping force that grips the speed governor rope 16 between the movable shoe 58 that has been displaced to the gripping position and the fixed shoe 57; and a holding apparatus 60 that holds the movable shoe 58 in the open position during normal operation, and that releases holding of the movable shoe 58 when the speed of the car 8 reaches a second preset overspeed that is higher than the first set overspeed.
  • The displacing pressing apparatus 59 has: a shoe extensible arm 61 that is connected between the mount portion that is disposed on the supporting body 24 and the movable shoe 58, and that can be extended and retracted; and a compressed spring (a forcing body) 62 that is disposed on the shoe extensible arm 61, and that forces the movable shoe 58 away from the mount portion of the supporting body 24.
  • The shoe extensible arm 61 is pivotably connected to both the mount portion of the supporting body 24 and the movable shoe 58. The movable shoe 58 is displaced between the gripping position and the open position by the shoe extensible arm 61 being pivoted relative to the mount portion of the supporting body 24. The shoe extensible arm 61 is pushed against the fixed shoe 57 and compressed when the movable shoe 58 is displaced to the gripping position. The shoe extensible arm 61 is subjected to the force of the compressed spring 62 and extended when the movable shoe 58 is displaced to the open position.
  • The compressed spring 62 is compressed between the mount portion of the supporting body 24 and the movable shoe 58. The compressed spring 62 is a coil spring through which the shoe extensible arm 61 has been passed internally. The force from the compressed spring 62 increases as the shoe extensible arm 61 is compressed.
  • A gripping force from the displacing pressing apparatus 59 arises due to the movable shoe 58 being displaced toward the gripping position and the force from the compressed spring 62 increasing.
  • The holding apparatus 60 has: an engaging lever 63 that is displaceable between an engaged position that engages with the movable shoe 58 and a released position in which engagement with the movable shoe 58 is disengaged; a releasing spring (a forcing body) 64 that forces the engaging lever 63 in such a direction as to be displaced toward the released position; and a restraining member 65 that holds the engaging lever 63 in the engaged position in opposition to the force from the releasing spring 64.
  • The engaging lever 63 is displaced between the engaged position and the released position by being pivoted around a lever shaft 66 that is disposed on the supporting body 24. The releasing spring 64 is connected between the engaging lever 63 and the supporting body 24.
  • The restraining member 65 is pivotable around a supporting shaft 67 that is disposed on the supporting body 24. The restraining member 65 is linked to the displacing body 33 by means of a link 68. The restraining member 65 is thereby pivoted around the supporting shaft 67 in response to the displacement of the displacing body 33.
  • The link 68 is pivotably connected to both the displacing body 33 and the restraining member 65. The link 68 is displaced upward by an increase in the rotational speed of the driven shaft 31.
  • The engaging lever 63 is held in the engaged position by the restraining member 65 during normal operation. The restraining member 65 is pivoted by upward displacement of the link 68 in a direction in which holding of the engaging lever 63 by the restraining member 65 is disengaged. Holding of the engaging lever 63 by the restraining member 65 is disengaged when the speed of the car 8 exceeds the first set overspeed and reaches a second set overspeed.
  • When holding of the engaging lever 63 by the restraining member 65 is disengaged, the engaging lever 63 is displaced from the engaged position to the released position by the force of the releasing spring 64, disengaging engagement between the movable shoe 58 and the engaging lever 63. When engagement between the movable shoe 58 and the engaging lever 63 is disengaged, the movable shoe 58 is displaced to the gripping position under its own weight, and the speed governor rope 16 is gripped between the fixed shoe 57 and the movable shoe 58.
  • Figure 7 is a graph that shows relationships between normal operating speed, a first set overspeed, and a second set overspeed, respectively, of the car 8 from Figure 1 and position of the car 8. As shown in the figure, the value of the first set overspeed 72 (the speed of the car 8 when the stopping switch 26 outputs the stopping signal) is a value that is higher than the normal operating speed 71 of the car 8 at all positions to which the car 8 moves. The value of the second set overspeed 73 (the speed of the car 8 when the emergency stopper apparatus 10 is activated due to gripping of the speed governor rope 16 by the speed governor main body 14) is a value that is higher than the value of the first set overspeed 72 at all positions through which the car 8 moves.
  • Since the length of the extensible bodies 38 changes depending on whether or not the car 8 is in either the upper end portion region or the lower end portion region, the value of the first set overspeed 72 is a first terminal portion reference value Vos' that is lower than a rated speed value V0 of the elevator when the car 8 is in either the upper end portion region or the lower end portion region, and is a first intermediate portion reference value Vos that is higher than the rated speed value V0 of the elevator (a value that is 1.3 times the rated speed, for example) when the car 8 is outside both the upper end portion region and the lower end portion region.
  • Since the length of the extensible bodies 38 changes depending on whether or not the car 8 is in either the upper end portion region or the lower end portion region, the value of the second set overspeed 73 is a second terminal portion reference value Vtr' that is lower than the rated speed value V0 of the elevator and higher than the first terminal portion reference value Vos' when the car 8 is in either the upper end portion region or the lower end portion region, and is a second intermediate portion reference value Vtr that is higher than the first intermediate portion reference value Vos when the car 8 is outside both the upper end portion region and the lower end portion region.
  • Next, operation will be explained. If the car 8 is moved at the normal operating speed 71, elevator operation will not be stopped forcibly, because the speed of the car 8 will not reach the first and second set overspeeds 72 and 73.
  • If the speed of the car 8 increases and reaches the first set overspeed 72 for some reason, a stopping signal is sent to the control apparatus 6 from the stopping switch 26. When the control apparatus 6 receives the stopping signal, elevator operation is stopped forcibly by the control apparatus 6.
  • If the speed of the car 8 subsequently increases further and reaches the second set overspeed despite shutdown control being performed by the control apparatus 6, then 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.
  • 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.
  • Next, operation when the values of the first and second preset overspeeds 72 and 73 are switched over will be explained. When the car 8 is in the intermediate portion of the hoistway 1 (i.e., when the car 8 is outside both the upper end portion region and the lower end portion region), none of the lower portion position switches 18a through 18c or the upper portion position switches 19a through 19c detect the cam 17. At this time, the radio signal is sent from the communications device 21 to the switching circuit 49, and supply of electric power from the generator 48 to the respective electromagnetic coils 45 is performed by means of the switching circuit 49.
  • When electric power is supplied to the respective electromagnetic coils 45, each of the extensible bodies 38 contracts, and the length of each of the extensible bodies 38 is shortened. The orbital radius of the fly balls 37 is thereby reduced, setting the value of the first set overspeed 72 to the first intermediate portion reference value Vos, and setting the value of the second set overspeed 73 to the second intermediate portion reference value Vtr.
  • If 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, one of the respective lower portion position switches 18a through 18c or the respective upper portion position switches 19a through 19c detects the cam 17. Output of the radio signal from the communications device 21 is thereby stopped, and the supply of electric power to each of the electromagnetic coils 45 is stopped.
  • When the supply of electric power to each of the electromagnetic coils 45 is stopped, each of the extensible bodies 38 extends, increasing the length of each of the extensible bodies 38. The orbital radius of the fly balls 37 is thereby increased, switching the value of the first set overspeed 72 over to the first terminal portion reference value Vos', which is lower than the first intermediate portion reference value Vos, and switching the value of the second set overspeed 73 over to the second terminal portion reference value Vtr', which is lower than the second intermediate portion reference value Vtr.
  • lf 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 first set overspeed 72 is switched over from the first terminal portion reference value Vos' to the first intermediate portion reference value Vos, and the value of the second set overspeed 73 is switched over from the second terminal portion reference value Vtr' to the second intermediate portion reference value Vtr by a reverse operation to the above,
  • In an elevator apparatus of this kind, because the length of the extensible bodies 38 is set so as to be different lengths when the car 8 is in either the upper end portion region or the lower end portion region, and when the car 8 is outside both the upper end portion region and the lower end portion region, the relationship between the amount of displacement of the extensible bodies 38 relative to the driven shaft 31 and the rotational speed of the driven shaft 31 can be changed. Thus, the respective values of the first and second preset overspeeds 72 and 73 when the car 8 is in either the upper end portion region or the lower end portion region can be lowered compared to when the car 8 is in the intermediate portion of the hoistway 1. ln other words, the car 8 can be stopped forcibly at a stage when the speed of the car 8 is lower at positions close to terminal portions of the hoistway 1 than when the car 8 is in the intermediate portion of the hoistway 1, enabling the deceleration distance of the car 8 to be shortened. Consequently, size reductions in the car buffer 22 and the counterweight buffer 23 can be achieved, enabling reductions in height dimensions of the hoistway 1.
  • 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 the relationships 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.
  • Because the switching apparatus 35 has: a generator 48 that generates electric power from the rotation of the driven shaft 31; and a switching circuit 49 that only sends electric power that is generated by the generator 48 to the electromagnetic coils 45 either when the car 8 is in either the upper end portion region or the lower end portion region, or when the car 8 is outside both the upper end portion region and the lower end portion region, the need to supply power separately from outside to change the length of the extensible bodies 38 can be eliminated.
  • Because the spacing between the lower portion position switches 18a through 18c and the spacing between the upper portion position switches 19a through 19c is narrower than the length of the cam 17, 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 either the upper end portion region or the lower end portion region. The presence or absence of the car 8 in the upper end portion region or the lower end portion region can thereby be detected more reliably.
  • Moreover, in the above example, information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region is sent to the switching circuit 49 using the radio signal from the communications device 21, but information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region may also be sent to the switching circuit 49 using a cable. In that case, two brushes are connected to a first end portion and a second end portion of the electric wire 20 instead of the communications device 21, and two sliding portions that the respective brushes contact are disposed on the driven shaft 31. The respective sliding portions are electrically connected to the switching circuit 49. The information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region is sent to the switching circuit 49 through the respective brushes and the respective sliding portions.
    • Embodiment 2
  • Figure 8 is a partially cutaway front elevation that shows a speed governor of an elevator apparatus according to Embodiment 2 of the present invention. Figure 9 is a cross section that is taken along line IX - lX in Figure 8. In the figures, a supporting body 24 is made of a member that has a U-shaped cross section that has a pair of facing walls that face each other. A bearing 29 is mounted separately to each of the facing walls of the supporting body 24. A sheave shaft (a predetermined revolving shaft) 28 of a speed governor sheave 15 is supported by the supporting body 24 by means of each of the bearings 29. The speed governor sheave 15 and the sheave shaft 28 are rotated together in response to movement of a car 8.
  • A pair of centrifugal weights 81 that revolve around the sheave shaft 28 in response to the rotation of the sheave shaft 28, and a pair of extensible bodies 82 to which the centrifugal weights 81 are connected, and that are pivotably connected to the speed governor sheave 15 by means of pins 83 are supported on the speed governor sheave 15.
  • The centrifugal weights 81 are subjected to centrifugal forces that correspond to the rotational speed of the sheave shaft 28 by revolving around the sheave shaft 28.
  • The extensible bodies 82 are displaced relative to the sheave shaft 28 by pivoting around the pins 83 in response to the centrifugal forces to which the centrifugal weights 81 are subjected. The extensible bodies 82 are thereby displaced relative to the sheave shaft 28 in directions in which the centrifugal weights 81 move away from the sheave shaft 28 if the rotational speed of the sheave shaft 28 increases, and the extensible bodies 82 are displaced relative to the sheave shaft 28 toward the sheave shaft 28 if the rotational speed of the sheave shaft 28 decreases.
  • The extensible bodies 82 have: first and second pivoting weight portions (extensible body main bodies) 84 that are pivotable around the pins 83 that are disposed on the speed governor sheave 15; and actuators 85 that are disposed on the pivoting weight portions 84, and that change the length of the extensible bodies 82. The respective pivoting weight portions 84 are linked to each other by means of linking members 86.
  • The actuators 85 have a similar configuration to the actuators 43 according to Embodiment 1, and have a plunger and an electromagnetic coil. The actuators 85 are disposed in a radial direction of the speed governor sheave 15.
  • The centrifugal weights 81 are mounted to the plungers of the actuators 85. The centrifugal weights 81 are disposed radially further outward on the speed governor sheave 15 than the pivoting weight portions 84. The length of the extensible bodies 82 changes when the plunger of the actuators 85 are displaced between an extended position and a retracted position. The length of the extensible bodies 82 is shortened when an electric current is passed to the electromagnetic coils of the actuators 85, and is lengthened by forcing bodies (not shown) when the passage of electric current to the electromagnetic coils of the actuators 85 is stopped.
  • The centrifugal weights 81 are displaced away from the sheave shaft 28 relative to the pivoting weight portions 84 when the length of the extensible bodies 82 is extended, and are displaced relative to the pivoting weight portions 84 toward the sheave shaft 28 when the length of the extensible bodies 82 is shortened.
  • A balancing spring 87 that opposes the centrifugal forces to which the centrifugal weights 81 are subjected is disposed between a first end portion of the first pivoting weight portion 84 and the speed governor sheave 15. An operating portion (in this example, a bolt) 88 is fixed to a second end portion of the first pivoting weight portion 84. The operating portion 88 is displaced away from the sheave shaft 28 when the rotational speed of the sheave shaft 28 increases, and is displaced toward the sheave shaft 28 when the rotational speed of the sheave shaft 28 decreases. An engaging hook 89 is disposed on the first pivoting weight portion 84. The engaging hook 89 is displaced toward the sheave shaft 28 when the rotational speed of the sheave shaft 28 increases, and is displaced away from the sheave shaft 28 when the rotational speed of the sheave shaft 28 decreases.
  • As shown in Figure 9, a switching apparatus 90 that changes the length of the extensible bodies 82 based on information (a radio signal) from a communications device 21 is disposed on the sheave shaft 28. The switching apparatus 90 makes the length of extensible bodies 82 different when the radio signal from the communications device 21 is received (i.e., when the car 8 is outside both the upper end portion region and the lower end portion region), and when the radio signal is not received (i.e., when the car 8 is in either the upper end portion region or the lower end portion region).
  • In this example, the switching apparatus 90 extends the length of the extensible bodies 82 when the car 8 is in either the upper end portion region or the lower end portion region, and shortens the length of the extensible bodies 82 when the car 8 is outside both the upper end portion region and the lower end portion region.
  • The switching apparatus 90 has: a generator 91 that generates electric power from the rotation of the sheave shaft 28; and a switching circuit 92 that controls the electric power that is sent from the generator 91 to the electromagnetic coils of the actuators 85 based on the information from the communications device 21.
  • The generator 91 has: an annular generator fixed portion 93 that includes permanent magnets; and an annular generator main body 94 that includes a power generating coil, and that surrounds the generator fixed portion 93. The generator fixed portion 93 is fixed to the supporting body 24. The generator fixed portion 93 surrounds the sheave shaft 28 so as to have a clearance interposed. The generator main body 94 is fixed to the speed governor sheave 15, and is rotated together with the speed governor sheave 15 and the sheave shaft 28. An electric current that corresponds to the rotation of the speed governor sheave 15 and the sheave shaft 28 arises in the power generating coil when the generator main body 94 is rotated.
  • The switching circuit 92 is fixed to the generator main body 94. Consequently, the switching circuit 92 is rotated together with the speed governor sheave 15 and the sheave shaft 28. The switching circuit 92 is electrically connected to the electromagnetic coils of the actuators 85 and to the generator main body 94 by respective conducting wires 95. The switching circuit 92 has a similar configuration to the switching circuit 49 according to Embodiment 1. Consequently, in this example, the electric current from the generator 91 is only sent to the electromagnetic coils of the actuators 85 by the switching circuit 92 when the car 8 is outside both the upper end portion region and the lower end portion region (i.e., when the radio signal is received from the communications device 21).
  • A stopping switch (an overspeed detecting switch) 96 is mounted to the supporting body 24, as shown in Figure 8. The stopping switch 96 has a similar configuration to the stopping switch 26 according to Embodiment 1, and has a switch main body 55 and a switch lever 56.
  • The operating portion 88 is able to operate the switch lever 56 by displacement of the pivoting weight portions 84 relative to the sheave shaft 28. The stopping switch 96 detects abnormality in the speed of the car 8 when the switch lever 56 is operated by the operating portion 88. A stopping signal that stops elevator operation is output from the switch main body 55 on detection of an abnormality in the speed of the car 8 by the stopping switch 96.
  • The speed of the car 8 at which the stopping switch 96 detects abnormality in the speed of the car 8 (a first set overspeed) is a value that is lower when the length of the extensible bodies 82 is long (when the car 8 is in either the upper end portion region or the lower end portion region) than when the length of the extensible bodies 82 is short (when the car 8 is outside both the upper end portion region and the lower end portion region) due to the difference in the orbital radius of the centrifugal weights 81.
  • A ratchet wheel 97 that is rotatable around the sheave shaft 28 is supported by the supporting body 24. A plurality of teeth are disposed on an outer circumferential portion of the ratchet wheel 97. The ratchet wheel 97 is able to rotate independently from the speed governor sheave 15. The engaging hook 89 is displaced toward the outer circumferential portion of the ratchet wheel 97 as the rotational speed of the sheave shaft 28 increases. The engaging hook 89 engages with the outer circumferential portion of the ratchet wheel 97 when the speed of the car 8 reaches a second set overspeed that is higher than a first set overspeed.
  • An arm 98 is disposed pivotably on the supporting body 24. A shoe (a braking segment) 99 that is pressed onto the speed governor sheave 15 so as to have the speed governor rope 16 interposed is disposed pivotably on an intermediate portion of the arm 98. A spring shaft 100 is passed through a leading end portion of the arm 98. An actuating lever 101 is connected between a first end portion of the spring shaft 100 and the ratchet wheel 97. A spring bearing member 102 and a nut 103 that prevents the spring bearing member 102 from disengaging from the spring shaft 100 are disposed on a second end portion of the spring shaft 100. A compressed spring 104 for generating a gripping force that grips the speed governor rope 16 is disposed between the leading end portion of the arm 98 and the spring bearing member 102.
  • Moreover, a gripping apparatus that grips the speed governor rope 16 includes the ratchet wheel 97, the arm 98, the shoe 99, the spring shaft 100, the actuating lever 101, the spring bearing member 102, the nut 103, and the compressed spring 104. The speed governor rope 16 is gripped between the speed governor sheave 15 and the shoe 99 when the shoe 99 is pressed onto the speed governor sheave 15 so as to have the speed governor rope 16 interposed. The rest of the configuration is similar to that of Embodiment 1.
  • The values of the first and second preset overspeeds are switched over by changing the length of the extensible bodies 82. The operation when switching the values of the first and second preset overspeeds over is similar to that of Embodiment 1.
  • Next, operation of the speed governor 12 will be explained. When the speed governor sheave 15 rotates together with the sheave shaft 28 in response to the movement of the car 8, the centrifugal weights 81 are displaced together with the extensible bodies 82 in response to the rotation of the speed governor sheave 15.
  • lf the speed of the car 8 increases and reaches the first set overspeed for some reason, the switch lever 56 is operated by the operating portion 88, and a stopping signal is sent to the control apparatus 6 from the stopping switch 96. When the control apparatus 6 receives the stopping signal, elevator operation is stopped forcibly by the control apparatus 6.
  • If the speed of the car 8 subsequently increases further and reaches the second set overspeed despite shutdown control being performed, then the engaging hook 89 is engaged in the ratchet wheel 97. The ratchet wheel 97 is thereby rotated slightly together with the speed governor sheave 15.
  • The rotation of the ratchet wheel 97 is subsequently transmitted to the arm 98 by means of the actuating lever 101, the spring shaft 100, the spring bearing member 102, and the compressed spring 104, pivoting the arm 98 toward the speed governor sheave 15. The shoe 99 thereby contacts the speed governor rope 16, and the shoe 99 is pressed against the speed governor rope 16 by the compressed spring 104. The speed governor rope 16 is thereby gripped between the speed governor sheave 15 and the shoe 99. Subsequent operation is similar to that of Embodiment 1.
  • Thus, even if centrifugal weights 81 are made to revolve around the sheave shaft 28 of the speed governor sheave 15, the relationship between the amount of displacement of the extensible bodies 82 relative to the sheave shaft 28 and the rotational speed of the sheave shaft 28 can be changed in a similar manner to Embodiment 1. From this, the respective values of the first and second preset overspeeds 72 and 73 when the car 8 is in either the upper end portion region or the lower end portion region can made lower than the rated speed, enabling the deceleration distance of the car 8 to be shortened. Consequently, size reductions in the car buffer 22 and the counterweight buffer 23 can be achieved, enabling reductions in height dimensions of the hoistway 1.
  • Moreover, in the above example, information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region is sent to the switching circuit 92 using the radio signal from the communications device 21, but information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region may also be sent to the switching circuit 92 using a cable. In that case, two brushes are connected to a first end portion and a second end portion of the electric wire 20 instead of the communications device 21, and two sliding portions that the respective brushes contact are disposed on the sheave shaft 28. The respective sliding portions are electrically connected to the switching circuit 92. The information as to whether or not the car 8 is in either the upper end portion region or the lower end portion region is sent to the switching circuit 92 through the respective brushes and the respective sliding portions.
  • ln each of the above embodiments, electric power that is generated by the generator is sent to the electromagnetic coils, but electric power that is supplied from a commercial power supply, or a battery, etc., may also be sent to the electromagnetic coils, for example.
  • In each of the above embodiments, the respective values of the first and second preset overspeeds 72 and 73 when the car 8 is in either the upper end portion region or the lower end portion region are values that are lower than the rated speed value V0 of the elevator, but the value of only the second set overspeed 73 when the car 8 is in either the upper end portion region or the lower end portion region may be a value that is higher than the rated speed value V0 of the elevator, or the respective values of the first and second preset overspeeds 72 and 73 may both be values that are higher than the rated speed value V0 of the elevator.

Claims (3)

  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; and
    a speed governor comprising:
    a centrifugal weight that revolves around a predetermined revolving shaft in response to the movement of the car;
    an extensible body that is connected to the centrifugal weight, and that is rotated around the revolving shaft and displaced relative to the revolving shaft in response to a centrifugal force to which the centrifugal weight is subjected due to the revolution; and
    a switching apparatus that extends and retracts the extensible body to set a length of the extensible body to different lengths when the car is inside the predetermined region and when the car is outside the predetermined region,
    the speed governor detecting presence or absence of an abnormality in a speed of the car based on the displacement of the extensible body relative to the revolving shaft.
  2. An elevator apparatus according to Claim 1, characterized in that:
    the extensible body comprises an electromagnetic coil that changes the length of the extensible body on receiving electric power; and
    the switching apparatus comprises:
    a generator that generates electric power in response to the revolution of the centrifugal weight; and
    a switching circuit that sends only a portion of the electric power to the electromagnetic coil, the portion of the electric power being generated either when the car is in the predetermined region, or when the car is outside the predetermined region.
  3. An elevator apparatus according to either of Claims 1 or 2, 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 the movement of the car; and
    spacing between each of the position switches is narrower than a length of the detected body parallel to the direction of movement of the car.
EP09848963A 2009-09-02 2009-09-02 Elevator apparatus Withdrawn EP2474498A1 (en)

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US9505587B2 (en) 2010-11-01 2016-11-29 Mitsubishi Electric Corporation Elevator with acceleration detection
US20240051793A1 (en) * 2022-08-15 2024-02-15 Otis Elevator Company Elevator pit maintenance systems

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JPH06263359A (en) * 1993-03-09 1994-09-20 Toshiba Corp Elevator governor
JP2001354372A (en) * 2000-06-14 2001-12-25 Mitsubishi Electric Corp Elevator device
JP2003104646A (en) 2001-09-28 2003-04-09 Mitsubishi Electric Corp Elevator device and controlling method therefor
WO2003091142A1 (en) * 2002-04-24 2003-11-06 Mitsubishi Denki Kabushiki Kaisha Overspeed governor apparatus for elevator system
CN101522554B (en) * 2006-10-18 2011-11-23 三菱电机株式会社 Elevator speed governor and elevator device
KR101044830B1 (en) * 2008-01-25 2011-06-28 미쓰비시덴키 가부시키가이샤 Elevator device

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