JP3871526B2 - Brake reaction force detection structure of actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect accurately the brake reaction force of an actuation device. SOLUTION: Separately from a spring receptacle 303 to receive springs 305 and 306, a hold-down member 302 is provided to receive the spring receptacle 303, and guidance is made by a guide sleeve 301 in such a way that the hold- down member 302 is not inclined. Thereby the hold-down member 302 can press a resilient member 322 uniformly without inclination even if the spring receptacle 303 receiving the brake reaction force is inclined when safety brake is in actuation. A pressure sensor 323 detects the brake reaction force through the resilient member 322.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an operating device for driving a brake device such as a railway vehicle.
[0002]
[Prior art]
For example, an actuator (electric brake actuator) published in a pamphlet of International Publication No. WO98 / 47750 based on the Patent Cooperation Treaty moves a push rod for driving the brake device in the axial direction based on the rotation of the motor. A service brake mechanism and a safety brake mechanism that moves the push rod in the axial direction by driving a specially shaped piston by releasing a spring held in a compressed state. FIG. 3 is a cross-sectional view schematically showing the structure of the safety brake mechanism in such an operating device.
[0003]
In the figure, a guide sleeve 102 is attached to the center of the inside of the housing 101, and a support sleeve 103 is externally attached to the outside of the guide sleeve 102. The upper end portion of the support sleeve 103 is a spring receiver 103a and can move in a minute range in the axial direction. A ring 104 made of an elastic material is interposed between the spring receiver 103a and the housing 101, and a total load is applied to the ring 104. A pressure sensor 105 is attached to the upper end portion of the housing 101, and this pressure sensor 105 is in contact with one place on the upper end surface of the ring 104. When this contact area is S1 and the pressure receiving area of the entire ring 104 is S, the load S1 / S of the total load received by the ring 104 is detected by the pressure sensor 105.
[0004]
A piston portion 106a of a wedge piston 106 is externally inserted into the support sleeve 103 so as to be slidable in the vertical direction. The wedge piston 106 includes a spring support portion 106b and a wedge portion 106c in addition to the piston portion 106a, and is integrally formed. A pair of wedge portions 106c are provided at a distance from each other in a direction perpendicular to the paper surface. A screw shaft 107 is screwed into the center of the wedge piston 106, and the wedge piston 106 can be moved in the vertical direction by the rotation of the screw shaft 107. Two springs 108 are mounted between the spring support portion 106b of the wedge piston 106 and the spring receiver 103a, and thereby the wedge piston 106 is biased downward. The rotation of the screw shaft 107 is prevented or permitted by a device (not shown) provided inside the support sleeve 103. Normally, in a state where the screw shaft 107 is rotated and the two springs 108 are compressed, the rotation of the screw shaft 107 is prevented in order to maintain this state.
[0005]
On the other hand, a push rod 109 for operating a brake device (not shown) is held by the guide tube 110. The guide tube 110 is held by a housing 101 so as to be movable in the left-right direction in the figure, and push bar rollers 111 are provided on both side surfaces thereof. A housing roller 112 is provided on the housing side. The wedge portion 106 c is engaged with the push rod roller 111 and the housing roller 112. When the rotation of the screw shaft 107 is allowed from the state shown in the drawing, the screw shaft 107 is rotated by the bias of the spring 108 and the wedge piston 106 is lowered. The wedge portion 106c pushes the push rod roller 111 to the left while descending, whereby the guide tube 110 and the push rod 109 move to the left, and the brake device is operated. When the brake is actually applied, the reaction force from the brake device is converted into the reaction force in the axial direction of the wedge piston 106 via the wedge portion 106c. This reaction force is detected by the pressure sensor 105 via the spring 108, the spring receiver 103a, and the ring 104. Therefore, when the pressure sensor 105 detects the predetermined reaction force, it can be confirmed that the predetermined braking force is actually generated.
[0006]
[Problems to be solved by the invention]
In the conventional actuating device as described above, the spring 108 has a high load. Such a high-load spring 108 has variations in the perpendicularity of the end surface with respect to the spring shaft, and the change in inclination during compression is greater than that of a low-load spring. For this reason, the spring receiver 103a may be slightly inclined. In this case, the load applied to the ring 104 is biased, and the pressure sensor 105 cannot detect an accurate reaction force.
[0007]
In view of the conventional problems as described above, an object of the present invention is to accurately detect a brake reaction force in an actuator.
[0008]
[Means for Solving the Problems]
The present invention relates to a brake reaction of an actuator having a service brake mechanism that moves a push rod that operates a brake device based on an output of a motor, and a safety brake mechanism that moves the push rod based on an output of a spring. A force detection structure,
A ring-shaped spring receiver that receives the spring, and a cylindrical member that passes the spring receiver on the outer periphery, and receives the spring receiver at a portion that extends outward in the radial direction, and an axis along the expansion and contraction direction of the spring A pressing member that can move in a predetermined range in a direction, a cylindrical portion that is provided on the housing side of the safety brake mechanism portion, guides the pressing member in the axial direction, and a hook-shaped portion in which a circumferential groove is formed. A guide member, a ring-shaped elastic member attached to the circumferential groove , one end surface of which is in contact with the end portion of the pressing member, and attached to the housing side of the safety brake mechanism portion, on the other end surface of the elastic member and a pressure sensor in contact, the pressing member by being extrapolated tightly into a cylindrical portion of the guide member, the shaft inclination is regulated with respect to the direction, the spring bearing, the Even when the spring bearing is tilted with respect to the axial direction so that it can be slightly tilted with respect to the direction and engages with the outer periphery of the pressing member, it is received without tilting the pressing member. The elastic member is pressed in the axial direction over the entire end portion (Claim 1).
[0009]
In the brake reaction force detection structure for an actuator configured as described above, the spring receiver is received by a pressing member that is a separate member. In addition, the guide member restricts the pressing member from moving in a direction inclined with respect to the axial direction. Therefore, even if the spring receiver is inclined, the pressing member receives the load without inclining and presses the elastic member uniformly. The pressure sensor detects the load via the elastic member that is uniformly pressed.
[0010]
Further , the holding of the elastic member and the guide of the pressing member that presses the elastic member are performed by a common guide member. Therefore, it is easy to ensure the assembly accuracy of the three members.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view showing an operating device employing a brake reaction force detection structure according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of the upper part of FIG. In FIG. 1, the said operating device is in the housing 1 comprised by the housing main body 1a, the upper cover 1b, and the lid | cover 1c attached to the center part of the upper cover 1b (however, it protrudes partially). , A service brake mechanism unit 2 using a motor as a drive source, a safety brake mechanism unit 3 using a spring output as a drive source, and a push rod mechanism unit driven by these two mechanism units with the horizontal direction in the figure as an axial direction. 4 is provided. The safety brake mechanism 3 operates as an emergency brake only when the motor is not usable or when a power failure occurs.
[0012]
In the push rod mechanism 4, the guide tube 401 is held by the housing 1 so as to be slidable in the axial direction. The push rod 402 inserted into the guide tube 401 has a cylindrical shape except for the left end portion, and can slide in the axial direction with respect to the guide tube 401. The push rod 402 has a built-in ball screw, and a ring 404 having an outer diameter smaller than the inner diameter of the guide tube 401 is fitted on the right end side small diameter portion 403a of the screw 403 constituting the ball screw. A thrust bearing 405 is mounted between the ring 404 and the right end 401 a of the guide tube 401. A gear ring 406 whose outer peripheral side is a gear is fitted on the right end 403 b of the screw 403. The radial bearing 407 is mounted between the inner cylindrical portion 406 a of the gear ring 406 and the right end portion 401 a of the guide tube 401.
[0013]
Further, the force transmission ring 408 is extrapolated and fixed to the guide tube 401. A pair of push rod rollers 409 are rotatably attached to both side surfaces of the force transmission ring 408. When the push rod roller 409 moves in the axial direction of the screw 403, the guide tube 401 moves via the force transmission ring 408. On the other hand, a pair of housing rollers 410 arranged on both side surfaces of the guide tube 401 so as to face the push rod roller 409 are rotatably supported by the housing 1.
[0014]
On the other hand, the service brake mechanism 2 is provided with a motor 200. The driven shaft 202 faces the right end of the shaft 201 of the motor 200 and is arranged coaxially with the shaft 201. A clutch device 203 is interposed between the shaft 201 and the driven shaft 202. A small gear 204 provided at the right end of the driven shaft 202 meshes with and drives a large gear 205 that is rotatably supported with respect to the housing 1. The large gear 205 meshes with the gear ring 406 to drive it. The clutch device 203 transmits the rotation of the shaft 201 to the driven shaft 202, and prevents the driven shaft 202 from rotating in the direction opposite to the direction in which the shaft 201 has been rotated when the shaft 201 stops rotating. It has a configuration.
[0015]
Moreover, in the safety brake mechanism part 3, the guide sleeve 301 which has the collar part 301a and the cylindrical part 301b is attached to the center of the upper cover 1b. A substantially cylindrical pressing member 302 is externally inserted into the cylindrical portion 301 b of the guide sleeve 301. The pressing member 302 is slidable with respect to the guide sleeve 301 within a minute predetermined range in the axial direction. A ring-shaped spring receiver 303 is loosely engaged with the outer periphery of the pressing member 302 to such an extent that a slight inclination with respect to the axial direction is possible .
[0016]
On the other hand, the wedge piston 304 includes a cylindrical piston portion 304a that is externally inserted into the pressing member 302, a substantially disc-shaped spring support portion 304b, and a pair of wedge portions 304c that are spaced apart from each other in a direction perpendicular to the paper surface. It has. The leading end of the wedge portion 304 c is engaged with the above-described push rod roller 409 and housing roller 410. Of the two large and small coil springs, the outer spring 305 is mounted between the spring support 304 b of the wedge piston 304 and the spring receiver 303. Further, the inner spring 306 is mounted between the spring support 304 b and the spring receiver 303 via another ring-shaped spring receiver 307. The screw shaft 308 is screwed into a female screw member 309 mounted on the inner periphery of the spring support 304b of the wedge piston 304, and forms a relationship like a ball screw.
[0017]
A cylindrical screw shaft support 310 is attached to the upper end side of the screw shaft 308. The cylindrical member 311 attached to the pressing member 302 has the same outer diameter as the screw shaft support 310. A thrust bearing 312 is mounted between the screw shaft support 310 and the cylindrical member 311. The locking sleeve 313 is inserted into the guide sleeve 301 with a gap in the radial direction. The locking spring 314 is wound around the outer periphery of the screw shaft support 310 and the cylindrical member 311, and one end thereof is locked to the locking sleeve 313 and the other end is locked to the screw shaft support 310.
[0018]
An electromagnet 315 is attached to the inside of the flange-shaped portion 301 a of the guide sleeve 301. A shaft member 318 is rotatably supported inside the electromagnet 315 via a bearing 317. The shaft member 318 includes a disk portion 318a, and a ring 316 made of a magnetic material is attached on the disk portion 318a. When the electromagnet 315 is excited, the ring 316 is attracted by this, and the shaft member 318 cannot rotate. Conversely, when the electromagnet 315 is demagnetized, the ring 316 is released and the shaft member 318 can rotate. The locking sleeve 313 is fitted to the lower end portion of the shaft member 318 and rotates integrally with the shaft member 318. Normally, the electromagnet 315 is excited, and the shaft member 318 and the locking sleeve 313 cannot rotate.
Each member in the safety brake mechanism unit 3 is coaxially arranged with the screw shaft 308 as the center.
[0019]
The central portion of the lower end of the pressing member 302 is engaged with a support ring 321 locked in a groove provided on a part of the outer periphery of the screw shaft 308. Thereby, the downward movement of the pressing member 302 is restricted. As shown in FIG. 2, the upper end portion 302 a of the pressing member 302 has a shape that can be inserted into a circumferential groove 301 c formed in the guide sleeve 301. A ring-shaped elastic member (rubber or the like) 322 is attached to the circumferential groove 301c, and its lower end surface is in contact with the entire end surface of the upper end portion 302a. Further, two step portions 302b are provided inside the upper end portion 302a, and the position where these step portions 302b abut on the corresponding step portion 301d of the guide sleeve 301 is the upper limit position of the pressing member 302. . That is, the pressing member 302 is slidable in the axial direction in a range from the lower limit position regulated by the support ring 321 (FIG. 1) to the upper limit position. Further, the pressing member 302 is extrapolated tightly with respect to the guide sleeve 301 to such an extent that the slight movement in the axial direction is not hindered. Thus, the guide sleeve 301 as a fixing member guides the pressing member 302 in the axial direction along the expansion and contraction directions of the springs 305 and 306 and restricts the movement of the pressing member 302 in a direction inclined with respect to the axial direction. It functions as a guiding member.
[0020]
On the other hand, the pressure sensor 323 is mounted from the upper surface of the guide sleeve 301 and is in contact with a part of the upper end surface of the elastic member 322. The pressure sensor 323 is fixed by a lock nut 324 screwed to the guide sleeve 301, and a cap 325 is put on the lock nut 324.
When the pressing member 302 slides and the elastic member 322 is pressed, an output signal corresponding to the load is output from the pressure sensor 323.
[0021]
The operation of the actuator configured as described above will be described.
First, the service brake operation will be briefly described. When the motor 200 rotates in a predetermined direction from the state shown in FIG. 1 (brake release state), the driven shaft 202 is rotationally driven via the clutch device 203. As a result, the small gear 204, the large gear 205, the gear ring 406, and the screw 403 rotate, and the push rod 402 moves forward in the left direction in the figure. As the push rod 402 advances, a brake device (not shown) is activated. When the motor 200 rotates in the reverse direction, the push rod 402 moves backward and the brake is released.
[0022]
Next, the safety brake operation will be described. In the state shown in FIG. 1, the springs 305 and 306 are accumulated, and the spring support 304b of the wedge piston 304 is urged downward. As a result, the screw shaft 308 is biased in the rotational direction corresponding to the downward movement of the wedge piston 304. Therefore, the locking sleeve 313 and the shaft member 318 are also urged in a predetermined rotational direction via the screw shaft support 310 and the locking spring 314. However, normally, since the shaft member 318 and the locking sleeve 313 cannot rotate, the screw shaft 308 does not rotate.
[0023]
When the electromagnet 315 is demagnetized based on the safety brake command from the above state, the ring 316 is released, and the shaft member 318 and the locking sleeve 313 start to rotate. Following this, the screw shaft support 310 and the screw shaft 308 also rotate, and the wedge piston 304 descends. When the wedge portion 304c of the descending wedge piston 304 is pushed between the push rod roller 409 and the housing roller 410, the movable push rod roller 409 moves to the left. Along with this, the guide tube 401 advances to the left via the force transmission ring 408. At this time, the guide tube 401 moves forward with the push rod 402 and all other members included therein and the gear ring 406. The gear ring 406 moves to the left while maintaining meshing with the large gear 205 having wide teeth. Thus, a brake device (not shown) is actuated by the push rod 402 that moves forward.
[0024]
By the operation of the brake device, the reaction force is converted into the reaction force in the axial direction of the wedge piston 304 via the wedge portion 304c. This reaction force is detected by the pressure sensor 323 via the springs 305 and 306, the spring receiver 307, the spring receiver 303, the pressing member 302 and the elastic member 322. Therefore, when the pressure sensor 323 detects the predetermined reaction force, it can be confirmed that the predetermined brake force is actually generated.
Here, when the springs 305 and 306 are inclined with respect to the axis of the wedge piston 304, the spring receiver 303 is slightly inclined, and the spring load applied to the spring receiver 303 is biased. However, the spring receiver 303 and the pressing member 302 are separate members, and the guide sleeve 301 restricts the movement of the pressing member 302 in a direction inclined with respect to the axial direction. Accordingly, the pressing member 302 receives a biased load without inclining, and presses the elastic member 322 uniformly over the entire upper end portion 302a (FIG. 2). Thereby, the pressure sensor 323 can accurately detect the reaction force.
[0025]
In order to return the safety brake mechanism 3 once operated, the motor 200 can be operated and then rotated in a predetermined direction, and the screw 403 is rotated in the braking direction. At this time, since the push rod 402 has already been advanced by a predetermined stroke and applied the brake, it cannot be further advanced. Therefore, the rotational force of the screw 403 is converted into a force for retracting the screw 403 itself, and a force in the retracting direction is applied to the guide tube 401, the force transmission ring 408, and the push rod roller 409. When a force in the backward direction is applied to the push rod roller 409, a force in the upward direction is applied to the wedge piston 304. As a result, the wedge piston 304 moves up while rotating the screw shaft 308, compresses the springs 305 and 306 again, and returns to the position shown in FIG.
[0026]
In the above embodiment, the spring receiver 303 and the pressing member 302 are made separate from each other, so that the shape of each member is smaller than the conventional support sleeve 103 (FIG. 3), and it is easy to process. Machining accuracy is improved. In addition, since the holding of the elastic member 322 and the guide of the pressing member 302 that presses the elastic member 322 are both performed by the guide sleeve 301, it is easy to ensure the assembly accuracy of the three members, and the elastic member 322. The pressing amount adjustment accuracy and the guide accuracy of the pressing member 302 can be kept constant.
[0027]
In the above embodiment, the guide sleeve 301 is a separate member from the upper cover 1b of the housing 1, but it is also possible to form both of them integrally. However, such a separate member is superior in the ease of centering the guide sleeve 301.
[0028]
【The invention's effect】
The present invention configured as described above has the following effects.
According to the brake reaction force detection structure for an actuating device according to claim 1, the spring receiver is received by a pressing member which is a separate member, and the pressing member is moved in a direction inclined with respect to the axial direction by the guide member. Therefore, even if the spring receiver is tilted, the pressing member receives the load without tilting and presses the elastic member uniformly. Therefore, the reaction force from the brake device can be accurately detected. Further, by making the spring receiver and the pressing member separate members, the shape of each member becomes small and the processing becomes easy, so that the processing accuracy is also improved.
[0029]
Further , since the holding of the elastic member and the guide of the pressing member that presses the elastic member are performed by the common guide member, it is easy to ensure the assembly accuracy of the three members, and the pressing amount adjustment of the elastic member The accuracy and the guide accuracy of the pressing member can be kept constant.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an operating device employing a brake reaction force detection structure according to an embodiment of the present invention.
FIG. 2 is an enlarged view of the upper part in FIG.
FIG. 3 is a cross-sectional view schematically showing the structure of a safety brake mechanism in a conventional operating device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Housing 2 Service brake mechanism part 3 Safety brake mechanism part 200 Motor 301 Guide sleeve (guide member)
302 Holding member 303 Spring receivers 305 and 306 Spring 322 Elastic member 323 Pressure sensor 402 Push rod

Claims (1)

A brake reaction force detection structure for an operating device having a service brake mechanism for moving a push rod for operating a brake device based on an output of a motor and a safety brake mechanism for moving the push rod based on an output of a spring. There,
A ring-shaped spring receiver for receiving the spring;
A cylindrical member that passes the spring receiver on the outer periphery, and that receives the spring receiver at a radially outwardly extending portion and is movable within a predetermined range in the axial direction along the expansion and contraction direction of the spring; ,
A cylindrical member that is provided on the housing side of the safety brake mechanism, guides the pressing member in the axial direction, and a guide member that has a hook-shaped portion formed with a circumferential groove ;
A ring-shaped elastic member attached to the circumferential groove , one end surface of which is in contact with the end of the pressing member;
A pressure sensor attached to the housing side of the safety brake mechanism, and abutting against the other end surface of the elastic member ;
The pressure member is tightly extrapolated to the cylindrical portion of the guide member, so that the inclination with respect to the axial direction is restricted,
The spring receiver is loose enough to allow a slight inclination with respect to the axial direction, and engages with the outer periphery of the pressing member,
Even when the spring receiver is inclined with respect to the axial direction, the pressing member receives the spring receiver without inclining, and the elastic member is pressed in the axial direction with the entire end portion. Reaction force detection structure.

Images