Unit brake device

Abstract

To provide a unit brake device that can drive a brake block even if a first drive unit becomes stuck or experiences other failures.SOLUTION: A unit brake device 1 has: a first drive unit 20 including an electric motor 21 and a conversion mechanism 22 for converting rotational motion of the electric motor 21 into linear motion, the first drive unit 20 being configured to use the linear motion to drive a brake block 2 in a braking direction and in a releasing direction that is opposite to the braking direction; and a second drive unit 15 configured to drive the brake block 2 in at least one of the braking direction and the releasing direction by causing the first drive unit 20 to move.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a unit brake device. [Background technology]

[0002] In the brake drive device described in Patent Document 1, a feed screw connected to the motor shaft of an electric motor is threadedly engaged with a feed nut, and as the motor shaft rotates, the feed nut and the feed screw rotate relative to each other, causing the feed nut to linearly reciprocate a push rod that can generate braking force in the brake device.A manual handle is provided at the end of the motor shaft, and by rotating the manual handle, the motor shaft can be manually rotated to release the brake device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-187074 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the brake drive device described in Patent Document 1, if the ball screw or the motor becomes stuck, the brake device cannot be driven. Note that this problem is not limited to ball screws, and a similar problem occurs in any brake device that has a transmission mechanism that converts the rotational motion of the motor into linear motion. [Means for solving the problem]

[0005] A unit brake device that solves the above problem has an electric motor and a conversion mechanism that converts the rotational motion of the electric motor into linear motion, and is equipped with a first drive unit that drives the brake shoes in a braking direction and a release direction that is the opposite direction to the braking direction using the linear motion, and a second drive unit that drives the brake shoes in at least one of the braking direction and the release direction by moving the first drive unit.

[0006] According to the above configuration, even if the conversion mechanism becomes stuck or the first drive unit is unable to move the brake shoes, the brake shoes can be driven together with the first drive unit by moving the first drive unit using the second drive unit.

[0007] In the above-mentioned unit brake device, it is preferable that the second drive unit has a power supply source that supplies power, and a transmission mechanism that transmits the power from the power supply source to the first drive unit and moves the first drive unit in the braking direction.

[0008] The above-mentioned unit brake device preferably includes a housing that houses the first drive unit, the housing having guide holes that are aligned with the braking direction and the release direction, and a support that supports the first drive unit within the housing so that it can move in the braking direction and the release direction, and the transmission mechanism transmits power from the supply source to the first drive unit through the guide holes.

[0009] In the above-mentioned unit brake device, it is preferable that the support portion has a first bush into which the first drive portion is inserted, and a second bush located farther from the brake shoe in the movement direction of the first drive portion than the first bush and into which the first drive portion is inserted.

[0010] In the above unit brake device, it is preferable that a restricting portion be provided on one of the inner surface of the housing and the outer surface of the first drive unit, which engages with the other and restricts the movement distance of the first drive unit within a predetermined range.

[0011] In the above-described unit brake device, it is preferable that the supply source is a pneumatic actuator having a cylinder to which compressed air is supplied and a piston that is moved by the compressed air to supply power to the transmission mechanism, the pneumatic actuator being housed in the cylinder and having a push-back mechanism that biases the piston, the push-back mechanism maintaining the relative position of the piston with respect to the cylinder when a force of a predetermined magnitude or greater is not acting on the first drive unit in a direction opposite to the release direction, and allowing the piston to move relative to the cylinder when a force of the predetermined magnitude or greater is acting.

[0012] In the above-described unit brake device, it is preferable that the transmission mechanism has a connecting mechanism that connects the supply source and the first drive unit so as to be movable relative to each other, an elastic member that biases the connecting mechanism, and a switching unit that can switch between a force-storage state in which the elastic member stores force and a release state in which the force-storage state is released, and when the switching unit switches to the force-storage state, power from the supply source is transmitted to the first drive unit via the transmission mechanism and the first drive unit moves in the release direction, and when the switching unit switches to the release state, the connecting mechanism is biased by the elastic member and the first drive unit moves in the release direction by the connecting mechanism.

[0013] In the above-described unit brake device, it is preferable that the connecting mechanism has a feed screw connected to the supply source and a nut fitted onto the feed screw and movable relative to the feed screw, and the switching unit is an electromagnetic brake.

[0014] In the above unit brake device, it is preferable that the transmission mechanism includes a lever having a point of application connected to the first drive portion and a point of effort connected to the supply source. In the above unit brake device, it is preferable that the levers are connected to both sides of the side surface of the first drive unit and support the first drive unit.

[0015] In the above unit brake device, the transmission mechanism preferably includes an arm connecting the supply source and the lever. In the above-described unit brake device, it is preferable that the transmission mechanism includes a conversion unit that converts the output direction of the power of the supply source into the movement direction of the first drive unit by using an inclined surface, thereby moving the first drive unit. [Effects of the Invention]

[0016] According to the present invention, the brake shoes can be driven even if the first drive portion is stuck or the like. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a perspective view showing the configuration of a first embodiment of a unit brake device. [Figure 2] FIG. 2 is a cross-sectional view showing the configuration of the unit brake device of the embodiment. [Figure 3] 5 is a schematic diagram showing the operation of the unit brake device of the embodiment. FIG. [Figure 4] 5 is a schematic diagram showing the operation of the unit brake device of the embodiment. FIG. [Figure 5] 5 is a schematic diagram showing the operation of the unit brake device of the embodiment. FIG. [Figure 6] 6A to 6C are cross-sectional views showing the operation of the second embodiment of the unit brake device. [Figure 7] 5 is a schematic diagram showing the operation of the unit brake device of the embodiment. FIG. [Figure 8] 5 is a schematic diagram showing the operation of the unit brake device of the embodiment. FIG. [Figure 9] FIG. 10 is a perspective view showing the configuration of a third embodiment of a unit brake device. [Figure 10] FIG. 2 is a cross-sectional view showing the configuration of the unit brake device of the embodiment. [Figure 11] FIG. 4 is an enlarged side view showing the operation of the unit brake device of the embodiment. [Figure 12] 5 is a cross-sectional view showing the operation of the unit brake device of the embodiment. FIG. [Figure 13] 4 is a side view showing the operation of the unit brake device of the embodiment. FIG. [Figure 14] 5 is a cross-sectional view showing the operation of the unit brake device of the embodiment. FIG. [Figure 15] 4 is a side view showing the operation of the unit brake device of the embodiment. FIG. [Figure 16] 5 is a cross-sectional view showing the operation of the unit brake device of the embodiment. FIG. [Figure 17] 4 is a side view showing the operation of the unit brake device of the embodiment. FIG. [Figure 18] FIG. 10 is a perspective view showing the configuration of a fourth embodiment of a unit brake device. [Figure 19] FIG. 2 is a cross-sectional view showing the configuration of the unit brake device of the embodiment. [Figure 20] 5 is a schematic diagram showing the operation of the unit brake device of the embodiment. FIG. [Figure 21] 5 is a cross-sectional view showing the operation of a supply unit of the unit brake device of the embodiment. FIG. [Figure 22] 5 is a schematic diagram showing the operation of the unit brake device of the embodiment. FIG. [Figure 23] 5 is a cross-sectional view showing the operation of a supply unit of the unit brake device of the embodiment. FIG. [Figure 24] 5 is a schematic diagram showing the operation of the unit brake device of the embodiment. FIG. [Figure 25] 5 is a cross-sectional view showing the operation of a supply unit of the unit brake device of the embodiment. FIG. [Figure 26] FIG. 10 is a side view showing the configuration of a modified example of the unit brake device. DETAILED DESCRIPTION OF THE INVENTION

[0018] (First embodiment) A first embodiment of a unit brake device will be described below with reference to Figures 1 to 5. The unit brake device presses brake shoes against the treads of wheels of a railway vehicle. The tread brake device includes wheels of the railway vehicle and the unit brake device.

[0019] (Unit brake device 1) 1 and 2, the unit brake device 1 drives the brake shoes 2 to press the brake shoes 2 against the wheel treads of the railway vehicle. The unit brake device 1 includes a first drive unit 20 and a second drive unit 15.

[0020] (First driving unit 20) The first drive unit 20 has an electric motor 21 and a conversion mechanism 22. The electric motor 21 is an electric motor. The conversion mechanism 22 converts the rotational motion of the electric motor 21 into linear motion. The first drive unit 20 drives the brake shoe 2 in the braking direction using the linear motion, pressing the brake shoe 2 against the tread of the wheel (not shown). The first drive unit 20 is equipped with an electromagnetic brake 23 that stops the rotation of the electric motor 21.

[0021] The conversion mechanism 22 includes a cylindrical sheath rod 24 that is rotated by the electric motor 21. The sheath rod 24 has an internal thread. The conversion mechanism 22 includes a push rod 25 that is threadedly connected to the inner surface of the sheath rod 24. The push rod 25 has an external thread. The base end side of the push rod 25 is threadedly connected to the inside of the sheath rod 24. A shoe head 13 is rotatably attached to the tip side of the push rod 25 via a connecting pin 25A. A hanger 14 is rotatably provided on the housing 10 via a connecting pin 14A. The shoe head 13 is rotatably attached to the hanger 14 via the connecting pin 25A. A brake shoe 2 is attached to the shoe head 13.

[0022] When the electric motor 21 of the first drive unit 20 rotates, the sheath rod 24 rotates, screwing the push rod 25, and the brake shoe 2 moves together with the push rod 25 in the braking direction, which is a direction in which it approaches the wheel tread, so that the brake shoe 2 is pressed against the wheel tread, braking the rotation of the wheel 3. The greater the amount of rotation of the electric motor 21, the greater the amount of movement of the push rod 25, and therefore the amount by which the brake shoe 2 is pressed against the wheel tread, in other words, the amount of friction, increases. On the other hand, when the electric motor 21 rotates in the opposite direction, the sheath rod 24 rotates in the opposite direction, screwing the push rod 25 in the opposite direction, so that the brake shoe 2 moves together with the push rod 25 in the release direction, which is a direction in which it moves away from the wheel tread, releasing the brake on the rotation of the wheel 3.

[0023] (Second driving unit 15) The second drive unit 15 drives the brake shoe 2 in a braking direction and a release direction, which is the direction opposite to the braking direction, by moving the first drive unit 20. The second drive unit 15 has a power supply source 15A and a transmission mechanism 15B. The power supply source 15A supplies power to move the first drive unit 20 in the braking direction. The transmission mechanism 15B transmits the power from the power supply source 15A to the first drive unit 20, causing the first drive unit 20 to move in the braking direction. The second drive unit 15 functions as a safety brake that drives the brake shoe 2 in place of the first drive unit 20.

[0024] The unit brake device 1 includes a housing 10 that houses a first drive unit 20 and a second drive unit 15. A mounting portion 10A is provided on the rear side (right side in FIG. 2) of the housing 10 to be attached to a bogie of a railway vehicle or the like. A transmission mechanism 15B is connected to the power supply 15A and includes a lever 11 that moves the first drive unit 20. A support portion 11B is provided in the center of the longitudinal direction of the lever 11. A support shaft 12 is inserted into the support portion 11B of the lever 11. The lever 11 is provided in the housing 10 so as to be rotatable by the support shaft 12. The support shaft 12 corresponds to a fulcrum of the lever 11. A tip end 11C of the lever 11 is bifurcated and is connected to both side surfaces 20A of the first drive unit 20 and supports the first drive unit 20. The tip end 11C of the lever 11 and the first drive unit 20 are rotatably connected by a connecting pin 20B. The connecting pin 20B, which is the connection point between the lever 11 and the first drive unit 20, functions as the point of action of the lever 11. The base end 11A of the lever 11 corresponds to the point of force. The lever 11 moves the first drive unit 20 when power is applied to the point of force from a power supply source 15A. The first drive unit 20 is suspended within the housing 10 with the support portion 11B of the lever 11 supported by a support shaft 12.

[0025] (First pneumatic actuator 30) The supply source 15A is a first pneumatic actuator 30. The first pneumatic actuator 30 has a cylindrical cylinder 31 with a bottom and a piston 32. Compressed air is supplied to the cylinder 31. The piston 32 moves by the compressed air and supplies power to the transmission mechanism 15B. The first pneumatic actuator 30 has a push-back mechanism 35. The first pneumatic actuator 30 is provided on the upper left side of the front side of the casing 10 in FIG. 2. The first pneumatic actuator 30 has a return spring 33, which biases the piston 32. A piston rod 32A protruding into the casing 10 is provided on the tip side of the piston 32. The piston rod 32A is rotatably connected to the base end 11A, which is the force point of the lever 11, via a connecting pin 34.

[0026] A supply port 30A is provided at the top of the cylinder 31 to supply compressed air into the cylinder 31. The compressed air is supplied to an operating chamber 31A surrounded by the cylinder 31 and the piston 32. When compressed air is supplied to the operating chamber 31A of the first pneumatic actuator 30, the piston rod 32A moves in a direction protruding from the cylinder 31 (to the right in FIG. 1), causing the lever 11 to rotate clockwise in FIG. 1. On the other hand, when compressed air is discharged from the operating chamber 31A of the first pneumatic actuator 30, the piston 32 moves toward the bottom side of the cylinder 31 (to the left in FIG. 1) due to the return spring 33, causing the lever 11 to rotate counterclockwise in FIG. 1.

[0027] The pushback mechanism 35 includes a piston 35A and an absorbing spring 35B. The piston 35A is disposed coaxially with the piston 32 of the first pneumatic actuator 30 and abuts against the piston 32 of the first pneumatic actuator 30. The absorbing spring 35B biases the piston 35A of the pushback mechanism 35 toward the first pneumatic actuator 30. The pushback mechanism 35 maintains the relative position of the piston 32 with respect to the cylinder 31 when a force equal to or greater than a predetermined magnitude is not applied to the first drive unit 20 in a direction opposite to the release direction. On the other hand, when a force equal to or greater than a predetermined magnitude is applied to the pushback mechanism 35, the piston 35A of the pushback mechanism 35 is pushed by the piston 32 of the first pneumatic actuator 30, compressing the absorbing spring 35B, thereby absorbing the input force and pushing it back. The absorbing spring 35B does not normally bias the piston 35A, but absorbs the movement and pushes it back when a reaction force equal to or greater than a predetermined magnitude is applied from the point of action of the lever 11.

[0028] (Operation of the first embodiment) Next, the operation of the unit brake device 1 configured as above will be described with reference to FIGS.

[0029] (normal time) As shown in Fig. 3, during normal operation when the first pneumatic actuator 30 is not driven, the first pneumatic actuator 30 and the first drive unit 20 are connected via a lever 11, and therefore the position of the first drive unit 20 is fixed. The first drive unit 20 drives the electric motor 21 to move the push rod 25 in the braking direction, which is the left direction in Fig. 3, thereby pressing the brake shoe 2 against the tread 3A of the wheel 3 and braking the wheel 3. The first drive unit 20 also drives the electric motor 21 in the opposite direction to move the push rod 25 in the release direction, which is the right direction in Fig. 3, thereby moving the brake shoe 2 away from the tread 3A of the wheel 3 and releasing the brake on the wheel 3.

[0030] (During pressing operation) As shown in Figure 4, during the pressing operation in which the brake shoe 2 is pressed against the tread 3A of the wheel 3, the position of the wheel 3 may fluctuate, and a greater-than-expected reaction force, which is a force in the opposite direction to the pressing force, may act on the first drive unit 20. In such a case, the reaction force of the pressing force is transmitted to the piston 32 of the first pneumatic actuator 30 via the lever 11. When the piston 32 moves leftward in Figure 4, the absorption spring 35B of the push-back mechanism 35 compresses to absorb the reaction force. At this time, because the length LA between the base end 11A and the support portion 11B of the lever 11 is longer than the length LB between the tip end 11C and the support portion 11B (LA > LB), the reaction force received by the push-back mechanism 35 is less than the reaction force received by the first drive unit 20.

[0031] (Safety brake on) As shown in FIG. 5, when the push rod 25 or the electric motor 21 of the first drive unit 20 is stuck and the first drive unit 20 cannot drive the brake shoe 2 from the released state, the brake shoe 2 is driven by the first pneumatic actuator 30. The second drive unit 15 functions as a safety brake. When compressed air is supplied to the cylinder 31 of the first pneumatic actuator 30, the piston 32 of the first pneumatic actuator 30 protrudes from the cylinder 31. The lever 11 then rotates clockwise around the support shaft 12 in FIG. 5, pressing the brake shoe 2 against the tread 3A of the wheel 3 and braking the wheel 3. Note that the greater the amount of rotation of the lever 11, the greater the amount by which the brake shoe 2 is pressed against the tread 3A of the wheel 3, in other words, the greater the amount of friction. On the other hand, when compressed air is discharged from the cylinder 31 of the first pneumatic actuator 30, the piston 32 of the first pneumatic actuator 30 returns to the cylinder 31. 5 around the support shaft 12, the brake shoe 2 separates from the tread 3A of the wheel 3, and the braking of the rotation of the wheel 3 is released. At this time, because the length LA between the base end 11A and the support portion 11B of the lever 11 is longer than the length LB between the tip end 11C and the support portion 11B (LA > LB), the output of the first pneumatic actuator 30 is amplified and the brake shoe 2 is driven.

[0032] (Effects of the first embodiment) Next, the effects of the first embodiment will be described. (1-1) Even if the conversion mechanism 22 becomes stuck or the first drive unit 20 is unable to drive the brake shoe 2, the brake shoe 2 can be driven together with the first drive unit 20 by moving the first drive unit 20 using the second drive unit 15.

[0033] (1-2) A push-back mechanism 35 that absorbs excessive reaction force when braking is provided to the cylinder 31 of the first pneumatic actuator 30. Therefore, there is no need to provide the push-back mechanism 35 separately from the first pneumatic actuator 30, which reduces the installation space.

[0034] (1-3) Power for moving the first drive unit 20 is transmitted from the power supply source 15A via the lever 11. Therefore, the first pneumatic actuator 30, which is the power supply source 15A that supplies power to the lever 11, can be provided at a position away from the first drive unit 20, and the first drive unit 20 can be prevented from becoming large.

[0035] (1-4) The tip portions 11C of the levers 11 are connected to both sides of the side surface 20A of the first driving portion 20. Therefore, the first driving portion 20 can be stably supported by the levers 11.

[0036] (Second embodiment) A second embodiment of the unit brake device will be described below with reference to Figures 6 to 8. The unit brake device of this embodiment differs from the first embodiment in that it can be switched between a connected state in which the supply source 15A and the transmission mechanism 15B are connected and a released state in which the connection is released. The following description will focus on the differences from the first embodiment.

[0037] As shown in FIG. 6 , the second drive unit 15 includes a nut 16. The piston rod 32A passes through the nut 16, and the base end 11A of the lever 11 is connected to the nut 16. The nut 16 is provided with a release mechanism (not shown). The release mechanism switches between a connected state in which the piston rod 32A and the nut 16 are connected and a released state in which the connection is released. For example, the release mechanism utilizes magnetic force and spring force. By demagnetizing the nut 16, the spring force connects the piston rod 32A and the nut 16, and by magnetizing the nut 16, the magnetic force cancels out the spring force, releasing the connection. Alternatively, the release mechanism may mechanically connect the piston rod 32A and the nut 16 and release the connection by disconnecting the nut 16. When the piston rod 32A and the nut 16 are connected, power is transmitted to the lever 11 by the first pneumatic actuator 30. On the other hand, when the piston rod 32A and the nut 16 are disconnected, no power is transmitted.

[0038] (When driven by the power of the power supply source 15A of the second driving unit 15) As shown in FIG. 7, when the push rod 25 or the electric motor 21 of the first drive unit 20 is stuck and the brake shoe 2 cannot be driven by the first drive unit 20, the brake shoe 2 is driven by the first pneumatic actuator 30. The second drive unit 15 functions as a safety brake. At this time, the release mechanism connects the piston rod 32A and the nut 16. When braking the wheel 3, compressed air is supplied to the operating chamber 31A of the first pneumatic actuator 30, causing the piston 32 of the first pneumatic actuator 30 to protrude from the cylinder 31. The lever 11 then rotates clockwise in FIG. 7 around the support shaft 12, pressing the brake shoe 2 against the tread 3A of the wheel 3 and braking the wheel 3. Note that the greater the amount of rotation of the lever 11, the greater the amount by which the brake shoe 2 is pressed against the tread 3A of the wheel 3, in other words, the greater the amount of friction.

[0039] On the other hand, when compressed air is discharged from the cylinder 31 of the first pneumatic actuator 30, the piston 32 of the first pneumatic actuator 30 returns into the cylinder 31. Then, the lever 11 rotates counterclockwise in FIG. 5 around the support shaft 12, the brake shoe 2 separates from the tread 3A of the wheel 3, and the braking of the rotation of the wheel 3 is released.

[0040] (When the brake is released by the release mechanism of the second drive unit 15) 8, when the connection between the piston rod 32A and the nut 16 is released by the release mechanism, the first drive unit 20 can be moved. If the electric motor 21 is locked due to a short circuit or the like, or if the first pneumatic actuator 30 becomes inoperable, the first drive unit 20 or the brake shoe 2 can be manually moved to move the brake shoe 2 together with the first drive unit 20 away from the tread 3A of the wheel 3. In addition, the nut 16 can be manually moved to move the brake shoe 2 together with the first drive unit 20 away from the tread 3A of the wheel 3 via the lever 11.

[0041] (Effects of the second embodiment) Next, the effects of the second embodiment will be described. In addition to the effects of the first embodiment, the following effects are achieved.

[0042] (2-1) When the first drive unit 20 or the supply source 15A is unable to move the brake shoe 2 while the brake shoe 2 is pressing against the wheel 3, the release mechanism disengages the connection between the piston rod 32A and the nut 16, thereby moving the first drive unit 20 and the brake shoe 2 in the release direction, and together with the first drive unit 20, the brake shoe 2 can be moved away from the wheel 3. For this reason, even if the first drive unit 20 or the supply source 15A becomes stuck, the braking can be released, further improving safety.

[0043] (Third embodiment) A third embodiment of the unit brake device will be described below with reference to Figures 9 to 17. The unit brake device of this embodiment differs from the first embodiment in the configuration of the second drive unit. The following description will focus on the differences from the first embodiment.

[0044] (Unit brake device 101) 9 and 10, the unit brake device 101 includes a first drive unit 20 and a second drive unit 115. The first drive unit 20 has the same configuration as in the first embodiment.

[0045] (Second driving unit 115) In a braking state in which the brake shoe 2 is pressed against the wheel tread by the first driving unit 20, the second driving unit 115 moves the first driving unit 20 in a release direction in which the brake shoe 2 moves away from the wheel, thereby releasing the braking state. The second driving unit 115 has a power supply 115A and a transmission mechanism 115B. The power supply 115A supplies power to move the first driving unit 20 in the braking direction. The transmission mechanism 115B transmits the power from the power supply 115A to the first driving unit 20, causing the first driving unit 20 to move in the braking direction.

[0046] The unit brake device 101 includes a housing 110 that houses the first drive unit 20 and the second drive unit 115. A mounting portion 110A is provided on the rear side (right side in FIG. 10) of the housing 110 for mounting to a bogie or the like of a railway vehicle. A housing portion 50 that houses the first drive unit 20 is provided on the inner wall of the housing 110. The unit brake device 101 includes a first bushing 50A and a second bushing 50B that serve as support portions. The first bushing 50A and the second bushing 50B are fixed to the inner wall of the housing 110. The first drive unit 20 is inserted into the first bushing 50A and the second bushing 50B, and supports the first drive unit 20 movably in the movement direction of the brake shoe 2. The second bushing 50B is located farther from the brake shoe 2 in the release direction than the first bushing 50A. The first bushing 50A and the second bushing 50B are members with a low coefficient of friction. For example, the first bushing 50A and the second bushing 50B are metal bushings, resin bushings, linear bushings, etc. Therefore, by supporting the first drive unit 20 with the entire housing 110, a large area is secured to support the weight of the first drive unit 20, reducing surface pressure and suppressing wear during sliding. A restricting portion 56 is provided on the inner surface of the housing 110. The restricting portion 56 is an annular member that is fixed to the inner surface of the housing 110. The restricting portion 56 restricts the movement distance of the first drive unit 20 in the braking direction to within a predetermined range. When the first drive unit 20 moves within the predetermined range in the braking direction, it comes into contact with the restricting portion 56.

[0047] As shown in FIGS. 9 and 11, the second drive unit 115 includes an L-shaped lever 53 that moves the first drive unit 20. The L-shaped lever 53 is connected to each of the opposite side surfaces of the first drive unit 20. The L-shaped lever 53 is rotatably connected to the second bushing 50B by a connecting pin 55. The connecting pin 55 functions as a fulcrum. The connecting pin 55 is provided at a corner of the L shape. One end of the L-shaped lever 53 is connected to the first drive unit 20, and the connection point with the first drive unit 20 functions as a point of application. The other end of the L-shaped lever 53 functions as a point of application of force. The ratio of the distance L1 between the fulcrum and the point of application and the distance L2 between the fulcrum and the point of application is 3:1 (L1:L2=3:1). The angle θ between the line connecting the fulcrum and the point of application and the line connecting the fulcrum and the point of application is 90°.

[0048] As shown in FIG. 11 , the housing 110 is provided with a guide hole 50C that guides the movement of the first drive unit 20 in the braking direction and the releasing direction due to the power transmitted from the transmission mechanism 115B. The guide hole 50C corresponds to a guide unit. The first drive unit 20 is provided with a connecting shaft 26 that passes through the guide hole 50C and is connected to one end of an L-shaped lever 53. The base end of the connecting shaft 26 is fixed to the first drive unit 20. A rectangular parallelepiped connecting member 26A that is connected to the L-shaped lever 53 is provided at the tip of the connecting shaft 26. The connecting shaft 26 and the connecting member 26A are connected by a bearing, and the connecting member 26A is rotatable relative to the connecting shaft 26. A connecting recess 53A that is larger than the outer shape of the connecting member 26A is provided on the surface of one end of the L-shaped lever 53 that faces the first drive unit 20. The connecting member 26A fits into the connecting recess 53A and comes into contact with the inner wall of the connecting recess 53A, thereby being moved by the L-shaped lever 53. The connecting shaft 26 and the connecting member 26A move together with the first drive unit 20 in the braking direction and the releasing direction. Meanwhile, the L-shaped lever 53 and the connecting recess 53A rotate around a connecting pin 55, which serves as a fulcrum. For this reason, the connecting recess 53A is set to be longer than the length of the connecting member 26A in the radial direction when the L-shaped lever 53 rotates, thereby allowing displacement of the connecting member 26A in the radial direction when the L-shaped lever 53 rotates. Therefore, the transmission mechanism 115B transmits power from the power supply source 115A to the first drive unit 20 through the guide hole 50C.

[0049] (Second pneumatic actuator 40) As shown in FIG. 10, the supply source 115A is a second pneumatic actuator 40. The second pneumatic actuator 40 has a cylindrical cylinder 41 with a bottom and a piston 42. Compressed air is supplied to the cylinder 41. The piston 42 is moved by the compressed air and supplies power to the transmission mechanism 115B. The second pneumatic actuator 40 has a push-back mechanism 47. The second pneumatic actuator 40 is provided at an upper part inside the housing 110. The second pneumatic actuator 40 has a return spring 43, which biases the piston 42. A piston rod 42A is provided on the tip side of the piston 42.

[0050] The cylinder 41 is provided with a supply port (not shown) for supplying compressed air into the cylinder 41. The compressed air is supplied to an operating chamber 41A surrounded by the cylinder 41 and the piston 42. When compressed air is supplied to the operating chamber 41A, the second pneumatic actuator 40 moves the piston rod 42A in a direction protruding from the cylinder 41 (toward the bottom in FIG. 10). On the other hand, when compressed air is discharged from the operating chamber 41A, the piston 42 of the second pneumatic actuator 40 moves by the return spring 43 toward the bottom side of the cylinder 41 (toward the bottom in FIG. 10).

[0051] The pushback mechanism 47 is provided between the piston 42 and the return spring 43 of the second pneumatic actuator 40. The pushback mechanism 47 includes a piston 47A and an absorption spring 47B. The piston 47A is provided coaxially with the piston 42 of the second pneumatic actuator 40. The absorption spring 47B urges the piston 47A of the pushback mechanism 47 in a direction away from the second pneumatic actuator 40. The pushback mechanism 47 maintains the relative position of the piston 42 of the second pneumatic actuator 40 with respect to the cylinder 41 when a force equal to or greater than a predetermined magnitude is not applied to the first drive unit 20 in a direction opposite to the release direction. On the other hand, when a force equal to or greater than the predetermined magnitude is applied to the pushback mechanism 47, the piston 42 is pulled downward, and the absorption spring 47B is compressed by the piston 42, thereby absorbing the input force and pushing it back. The absorbing spring 47B does not normally bias the piston 47A, but absorbs the movement and pushes back when a reaction force of a predetermined magnitude or greater is input from the point of action of the L-shaped lever 53.

[0052] As shown in FIGS. 9 and 10 , the transmission mechanism 115B includes a return spring 43, a feed screw 44, a nut 45, and a switching unit 46. The return spring 43 functions as an elastic member. The feed screw 44 is connected to a piston rod 42A of the second pneumatic actuator 40. The nut 45 is fitted to the feed screw 44 and is movable relative to the feed screw 44. The feed screw 44 and the nut 45 function as a connecting mechanism that connects the supply source 115A and the first drive unit 20 to allow relative movement. The switching unit 46 can switch between a force storage state in which the return spring 43 stores force and a release state in which the force storage state is released. The switching unit 46 is an electromagnetic brake that is connected to the feed screw 44 and restricts rotation of the feed screw 44. The switching unit 46 includes an operating lever 46A that protrudes externally and can be operated to switch between a force storage state and a release state, in other words, a restriction state and a release state. A restricting portion 44A is provided at the tip of the feed screw 44. When the nut 45 comes into contact with the restricting portion 44A, the downward movement of the feed screw 44 is restricted. Therefore, the amount of movement of the first drive portion 20 can be limited.

[0053] When the switching unit 46 restricts the rotation of the feed screw 44, the return spring 43 enters a force-storing state, and the nut 45 moves together with the piston 42 of the second pneumatic actuator 40, so that the first drive unit 20 is driven by the power of the second pneumatic actuator 40. That is, when the switching unit 46 switches to the force-storing state, power from the supply source 115A is transmitted to the first drive unit 20 via the feed screw 44 and the nut 45, and the first drive unit 20 moves in the release direction. On the other hand, when the restriction on the rotation of the feed screw 44 by the switching unit 46 is released, the feed screw 44 rotates within the nut 45 due to the biasing force of the return spring 43, and the nut 45 moves toward the tip side of the feed screw 44 (the lower side in FIG. 12 ). That is, when the switching unit 46 switches to the release state, the nut 45 is biased by the return spring 43, and the first drive unit 20 moves in the release direction due to the nut 45. In this case, the first drive unit 20 can be moved in the release direction without using the power of the second pneumatic actuator 40.

[0054] As shown in FIG. 9, the transmission mechanism 115B includes an arm 51. The arm 51 is provided between an L-shaped lever 53 and the second pneumatic actuator 40. The upper end of the arm 51 is connected to a nut 45 by a connecting pin 52. The lower end of the arm 51 is connected to the force point, which is the other end of the L-shaped lever 53, by a connecting pin 54. When the nut 45 moves together with the piston 42 of the second pneumatic actuator 40, the arm 51 moves in the up and down direction. Then, power is transmitted to the force point of the L-shaped lever 53 by the movement of the arm 51.

[0055] (Operation of the third embodiment) Next, the operation of the unit brake device 101 configured as above will be described with reference to FIGS.

[0056] (normal time) As shown in FIG. 12 , under normal circumstances, the switching unit 46 restricts the rotation of the feed screw 44, and the position of the nut 45 relative to the feed screw 44 is fixed. Therefore, unless the second pneumatic actuator 40 is driven, the arm 51 and the L-shaped lever 53 do not move. Therefore, the position of the first drive unit 20 is fixed. The first drive unit 20 drives the electric motor 21 to move the push rod 25 in the braking direction, which is the left direction in FIG. 12 , thereby pressing the brake shoe 2 against the wheel tread and braking the wheel. The first drive unit 20 also drives the electric motor 21 in the opposite direction to move the push rod 25 in the release direction, which is the right direction in FIG. 12 , thereby moving the brake shoe 2 away from the wheel tread and releasing the wheel brake.

[0057] (During pressing operation) 13, during the pressing operation in which the brake shoe 2 is pressed against the wheel tread, the position of the wheel may fluctuate, and a greater-than-expected reaction force, which is a force in the opposite direction to the pressing force, may act on the first drive unit 20. In such a case, when the reaction force of the pressing force by the first drive unit 20 is applied to the L-shaped lever 53, the force is transmitted in the counterclockwise direction around the connecting pin 55, which functions as a fulcrum, and the nut 45, feed screw 44, and piston 42 move downward together with the arm 51. When the piston 42 moves downward, the absorption spring 47B of the push-back mechanism 47 contracts, absorbing the reaction force and pushing it back.

[0058] (When driven by the power of the supply source 115A of the second driving unit 115) As shown in Figures 14 and 15, if the push rod 25 or electric motor 21 of the first drive unit 20 is stuck and the brake shoe 2 cannot be driven by the first drive unit 20, the brake shoe 2 is driven by the second pneumatic actuator 40. The second drive unit 115 functions as a safety brake. When braking the wheel, compressed air is supplied to the operating chamber 41A of the second pneumatic actuator 40. The piston 42 of the second pneumatic actuator 40 moves upward together with the feed screw 44. Because the rotation of the feed screw 44 is restricted by the switching unit 46, the nut 45 and arm 51 also move upward. When the arm 51 moves upward, the L-shaped lever 53 rotates clockwise around the connecting pin 55, which functions as a fulcrum, and moves the first drive unit 20 to the left in Figure 15 via the connecting shaft 26. 15 together with the first drive unit 20, the push rod 25 and the brake shoe 2 are moved to the left in Fig. 15, and the brake shoe 2 is pressed against the wheel tread, braking the wheel. Note that a pressing force corresponding to the pressure supplied to the second pneumatic actuator 40 is generated.

[0059] 14, the first drive unit 20 comes into contact with a restricting portion 56 provided in the housing portion 50 of the housing 110, thereby stopping the movement of the first drive unit 20 to the left in FIG. 14. This makes it possible to limit the amount of movement of the first drive unit 20.

[0060] When the wheel brake is released, compressed air is discharged from the working chamber 41A of the second pneumatic actuator 40. The piston 42, feed screw 44, and nut 45 move downward due to the biasing force of the return spring 43. When the arm 51 moves downward together with the nut 45, the L-shaped lever 53 rotates counterclockwise around the connecting pin 55, which functions as a fulcrum, and moves the first drive unit 20 to the right in FIG. 15 via the connecting shaft 26. As a result, the brake shoe 2 moves away from the wheel tread, and the brake on the wheel rotation is released.

[0061] (When the brake applied by the return spring 43 of the second drive unit 115 is released) As shown in FIGS. 16 and 17 , when the push rod 25 or the electric motor 21 of the first drive unit 20 is stuck and generates a pressing force, the switching unit 46 releases the restriction on the feed screw 44, allowing the feed screw 44 to rotate. The reaction force of the pressing force pulls the nut 45 downward, and the stored force of the return spring 43 is released, causing the feed screw 44 to rotate and move the nut 45 downward. As a result, the arm 51 moves downward together with the nut 45, causing the L-shaped lever 53 to rotate counterclockwise around the connecting pin 55, which functions as a fulcrum, and moves the first drive unit 20 to the right in FIG. 17 via the connecting member 26A and the connecting shaft 26. Even when the reaction force of the pressing force disappears, the stored force of the return spring 43 is released, urging the nut 45, and the first drive unit 20 remains in the right position in FIG. 17 . Therefore, a gap is maintained between the brake shoe 2 and the wheel tread.

[0062] As shown in Figure 14, the nut 45 comes into contact with a restricting portion 44A provided at the tip of the feed screw 44, thereby stopping its downward movement. This makes it possible to limit the amount of movement of the first drive unit 20. Because the movement range of the nut 45 is limited by the restricting portion 44A, even if the nut 45 is moved to the release position by the release mechanism while not yet released, it can be braked by supplying air to the second pneumatic actuator 40. Furthermore, because the position of the first drive unit 20 is fixed, a pressing operation by the first drive unit 20 can be performed.

[0063] (Effects of the third embodiment) Next, the effects of the third embodiment will be described. (3-1) Even if the conversion mechanism 22 becomes stuck or the first drive unit 20 is unable to drive the brake shoe 2, the brake shoe 2 can be moved together with the first drive unit 20 by moving the first drive unit 20 using the second drive unit 115.

[0064] (3-2) Power is transmitted from the supply source 115A to the first drive unit 20 through the guide hole 50C by the transmission mechanism 115B, and the first bush 50A and the second bush 50B, which are support units, support the first drive unit 20 so that the first drive unit 20 can move in the braking direction and the releasing direction of the brake shoe 2. This defines the direction of movement of the first drive unit 20, allowing the first drive unit 20 to move stably.

[0065] (3-3) The first driving unit 20 is inserted into and supported by the first bushing 50A and the second bushing 50B. Therefore, the first driving unit 20 is supported at two locations, allowing the first driving unit 20 to move more smoothly.

[0066] (3-4) The movement distance of the first drive unit 20 is restricted to a predetermined range by the restricting unit 56. This prevents the second drive unit 115 from moving the first drive unit 20 more than necessary.

[0067] (3-5) A push-back mechanism 47 that absorbs excessive reaction force when braking is provided to the cylinder 41 of the second pneumatic actuator 40. Therefore, it is not necessary to provide the push-back mechanism 47 separately from the second pneumatic actuator 40, which reduces the installation space.

[0068] (3-6) L-shaped levers 53 are connected to both sides of the side surface of the first driving unit 20. Therefore, the L-shaped levers 53 allow the first driving unit 20 to move stably. (3-7) When the brake shoe 2 is pressing against the wheel and the first drive unit 20 or the second pneumatic actuator 40 becomes stuck and is unable to move the brake shoe 2, the switching unit 46 releases the biasing force of the return spring 43, causing the feed screw 44 and nut 45, which are the connecting mechanism, to move the first drive unit 20, moving the brake shoe 2 in the release direction and moving the brake shoe 2 together with the first drive unit 20 away from the wheel. Therefore, even if the first drive unit 20 or the supply source 115A becomes stuck, braking can be released, further improving safety.

[0069] (3-8) The second pneumatic actuator 40, which is the supply source 115A, and the L-shaped lever 53 are connected by the arm 51. Therefore, power is transmitted from the supply source 115A via the arm 51 and the L-shaped lever 53. Therefore, the second pneumatic actuator 40, which is the supply source 115A, can be provided at a position away from the first drive unit 20, preventing the first drive unit 20 from becoming larger.

[0070] (Fourth embodiment) A fourth embodiment of the unit brake device will be described below with reference to Figures 18 to 25. The unit brake device of this embodiment differs from the first embodiment in the configuration of the second drive unit. The following description will focus on the differences from the first embodiment.

[0071] (Unit brake device 201) 18 and 19, the unit brake device 201 includes a first drive unit 20 and a second drive unit 215. The first drive unit 20 has the same configuration as in the first embodiment.

[0072] (Second driving unit 215) The second drive unit 215 drives the brake shoe 2 in the braking direction and the release direction by moving the first drive unit 20. The second drive unit 215 has a power supply 215A and a transmission mechanism 215B. The power supply 215A supplies power to move the first drive unit 20 in the braking direction. The transmission mechanism 215B transmits the power from the power supply 215A to the first drive unit 20, causing the first drive unit 20 to move in the braking direction.

[0073] The unit brake device 201 includes a housing 210 that houses the first drive unit 20 and the second drive unit 215. A mounting portion 210A is provided on the rear side (right side in FIG. 19) of the housing 210 for mounting to a bogie of a railway vehicle or the like. A housing portion 70 that houses the first drive unit 20 is provided on the inner wall of the housing 210. The unit brake device 201 includes a bush 70A that serves as a support portion. The bush 70A is fixed to the inner wall of the housing 210. The bush 70A supports the first drive unit 20 so that it can move in the direction of movement of the brake shoe 2. The bush 70A is a member with a low coefficient of friction. For example, the bush 70A is a metal bush, a resin bush, a linear bush, or the like.

[0074] As shown in FIG. 18, the second drive unit 215 includes a conversion unit 72 that moves the first drive unit 20. The conversion unit 72 includes a plate-shaped connection unit 72A and arms 72B extending from both ends of the connection unit 72A. The arms 72B are connected to both side surfaces of the first drive unit 20. The arms 72B of the conversion unit 72 are connected to the first drive unit 20 via a connecting shaft 74. The connecting shaft 74 abuts against the inner wall of an oblique hole 73 provided in the conversion unit 72. The conversion unit 72 is connected to a power supply source 215A that supplies power. The conversion unit 72 converts the output direction of the power of the power supply source 215A (the up-down direction in FIG. 19) via the oblique hole 73 into the movement direction of the first drive unit 20 (the left-right direction in FIG. 19), thereby moving the first drive unit 20. The inner wall of the oblique hole 73 corresponds to a slope.

[0075] (Third pneumatic actuator 60) As shown in FIG. 19, the supply source 215A is a third pneumatic actuator 60. The third pneumatic actuator 60 has a cylindrical cylinder 61 with a bottom and a piston 62. Compressed air is supplied to the cylinder 61. The piston 62 is moved by the compressed air and supplies power to the transmission mechanism 215B. The third pneumatic actuator 60 has a push-back mechanism 65. The third pneumatic actuator 60 is provided at an upper part inside the housing 210. The third pneumatic actuator 60 has a return spring 63, and the return spring 63 biases the piston 62. A piston rod 62A is provided on the tip side of the piston 62. A conversion unit 72 is connected to the piston rod 62A.

[0076] The cylinder 61 is provided with a supply port 60A (see FIG. 18) that supplies compressed air into the cylinder 61. The compressed air is supplied to an operating chamber 61A surrounded by the cylinder 61 and the piston 62. When compressed air is supplied to the operating chamber 61A, the third pneumatic actuator 60 moves the piston rod 62A in a direction that protrudes from the cylinder 61 (toward the bottom in FIG. 19). On the other hand, when compressed air is discharged from the operating chamber 61A, the piston 62 of the third pneumatic actuator 60 moves by the return spring 63 toward the bottom side of the cylinder 61 (to the left in FIG. 19).

[0077] The push-back mechanism 65 is provided on the bottom side of the third pneumatic actuator 60. The push-back mechanism 65 includes a piston 65A and an absorbing spring 65B. The piston 65A is provided coaxially with the piston 62 of the third pneumatic actuator 60. The absorbing spring 65B urges the piston 65A of the push-back mechanism 65 in a direction that pushes the piston 62 of the third pneumatic actuator 60. The absorbing spring 65B does not normally urge the piston 65A, but absorbs the movement and pushes it back when a reaction force is input from the conversion unit 72.

[0078] (Operation of the fourth embodiment) Next, the operation of the unit braking device 201 configured as above will be described with reference to FIGS.

[0079] (normal time) As shown in Figures 20 and 21, under normal circumstances, unless the third pneumatic actuator 60 is driven, the piston rod 62A and the conversion unit 72 do not move. Therefore, the position of the first drive unit 20 is fixed. The first drive unit 20 drives the electric motor 21 to move the push rod 25 in the braking direction, which is to the left in Figure 20, thereby pressing the brake shoe 2 against the wheel tread and braking the wheel. The first drive unit 20 also drives the electric motor 21 in the determination direction to move the push rod 25 in the release direction, which is to the right in Figure 20, thereby moving the brake shoe 2 away from the wheel tread and releasing the wheel brake.

[0080] (During pressing operation) 22 and 23, during the pressing operation of pressing the brake shoe 2 against the wheel tread, the position of the wheel may fluctuate, causing a greater-than-expected reaction force, which is a force in the opposite direction to the pressing force, to act on the first drive unit 20. In such a case, when the reaction force of the pressing force by the first drive unit 20 is applied to the conversion unit 72, the force is transmitted to the piston 62, and the absorbing spring 65B of the push-back mechanism 65 contracts, absorbing the reaction force and pushing it back.

[0081] (When driven by the power of the supply source 215A of the second driving unit 215) As shown in Figures 24 and 25, if the push rod 25 or the electric motor 21 of the first drive unit 20 is stuck and the brake shoe 2 cannot be driven by the first drive unit 20, the brake shoe 2 is driven by the third pneumatic actuator 60. The second drive unit 215 functions as a safety brake. When braking the wheel, compressed air is supplied to the operating chamber 61A of the third pneumatic actuator 60. The piston 62 of the third pneumatic actuator 60 moves downward. The conversion unit 72 also moves downward, and the connecting shaft 74 is moved to the left in Figure 24 by the oblique hole 73 of the conversion unit 72. At the same time, the first drive unit 20 also moves to the left in Figure 24, pressing the brake shoe 2 against the wheel tread and braking the wheel. A pressing force corresponding to the pressure supplied to the third pneumatic actuator 60 is generated.

[0082] When the wheel brake is released, compressed air is discharged from the working chamber 61A of the third pneumatic actuator 60. The piston 62 moves upward due to the biasing force of the return spring 63. When the piston 62 moves upward, the conversion part 72 also moves upward, and the connecting shaft 74 is moved to the right in FIG. 24 by the oblique hole 73 of the conversion part 72, and the first drive part 20 is also moved to the right in FIG. 24. As a result, the brake shoe 2 moves away from the wheel tread, and the brake on the wheel rotation is released.

[0083] (Effects of the fourth embodiment) Next, the effects of the fourth embodiment will be described. (4-1) Even if the conversion mechanism 22 becomes stuck or the first drive unit 20 is unable to move the brake shoe 2, the brake shoe 2 can be driven together with the first drive unit 20 by moving the first drive unit 20 using the second drive unit 215.

[0084] (4-2) The bushing 70A, which is the support part, supports the first drive part 20 so that it can move in the braking direction and the releasing direction of the brake shoe 2. Therefore, the movement direction of the first drive part 20 when the first drive part 20 is moved by the second drive part 215 is regulated, and the movement of the first drive part 20 can be stabilized.

[0085] (4-3) A push-back mechanism 65 that absorbs excessive reaction force when braking is provided to the cylinder 61 of the third pneumatic actuator 60. Therefore, there is no need to provide the push-back mechanism 65 separately from the third pneumatic actuator 60, which reduces the installation space.

[0086] (4-3) Power for moving the first drive unit 20 is transmitted from the second pneumatic actuator 40, which is the supply source 215A, via the conversion unit 72. Therefore, the second pneumatic actuator 40 can be provided at a position away from the first drive unit 20, preventing the first drive unit 20 from becoming larger.

[0087] (Other embodiments) The above-described embodiments can be modified as follows: The above-described embodiments and the following modifications can be combined with each other within the scope of technical compatibility.

[0088] In the above embodiments, a pneumatic actuator is used as the supply source, but it is not limited to a pneumatic actuator, and other actuators such as an electric actuator or a spring cylinder may also be used.

[0089] In the above embodiments, the electric motor 21 is used as the power source of the first drive unit 20. However, the power source is not limited to an electric motor, and other actuators such as an electric cylinder, a pneumatic actuator, or a spring may also be used.

[0090] In each of the above embodiments, a push-back mechanism is provided to absorb the reaction force of the pressing force, but the push-back mechanism may be omitted. In the third embodiment, the inner surface of the housing 110 is provided with the restricting portion 56 that engages with the outer surface of the first drive unit 20 to restrict the movement distance of the first drive unit 20 within a predetermined range. However, a restricting portion that engages with the inner surface of the housing 110 to restrict the movement distance of the first drive unit 20 within a predetermined range may be provided on the outer surface of the first drive unit 20.

[0091] In the third embodiment, connecting pin 55 serving as a fulcrum is provided at the corner of the L-shape of L-shaped lever 53, connecting shaft 26 serving as a point of application is provided at one end of L-shaped lever 53, and connecting pin 54 serving as a point of force is provided at the other end of L-shaped lever 53. However, as shown in Fig. 26, connecting shaft 26 serving as a point of application may be provided at the corner of the L-shape of L-shaped lever 53, connecting pin 55 serving as a fulcrum is provided at one end of L-shaped lever 53, and connecting pin 54 serving as a point of force may be provided at the other end of L-shaped lever 53. Note that the shape of the lever may be set arbitrarily as long as it has a fulcrum, a point of application, and a point of force.

[0092] In the first and second embodiments, the tip portions 11C of the lever 11 are provided on both sides of the side surface of the first driving unit 20. However, the connecting portion of the lever 11 may be provided on only one side of the side surface of the first driving unit 20.

[0093] In the third embodiment, the L-shaped levers 53 are provided on both sides of the side surface of the first drive unit 20. However, the L-shaped levers 53 may be provided on only one side of the side surface of the first drive unit 20. In the third embodiment, the nut 45, the feed screw 44, and the switching unit 46 are used to block the transmission of power from the power supply source 115A. However, other mechanisms may be used as long as they are capable of blocking the transmission of power from the power supply source 115A. The switching unit 46 may be operated by an electrical signal or manually.

[0094] In the third embodiment, as shown in FIG. 13, the angle α of the second drive unit 115 including the second pneumatic actuator 40 relative to the vertical direction can be changed in accordance with interference with the wheels or the carriage by changing the angle θ of the L-shaped lever 53.

[0095] In the third embodiment, as shown in Fig. 13, the ratio (L1:L2) of the distance L1 between the fulcrum and the point of force to the distance L2 between the fulcrum and the point of action is set to 3:1. However, this can be set arbitrarily depending on the capacity of the supply source 115A.

[0096] In the third and fourth embodiments, the bushings fixed to the housings 110 and 210 serve as the support parts to support the first drive unit 20. However, a mechanism such as a slide rail or a bearing may be provided as the support part between the housings 110 and 210 and the first drive unit 20.

[0097] In the third and fourth embodiments, the bushings fixed to the housings 110 and 210 support the first drive unit 20. However, the housings 110 and 210 themselves may be the support units that movably support the first drive unit 20.

[0098] In each of the above embodiments, the second drive unit 15, 115, 215 is provided at a position separated from the first drive unit 20 via the transmission mechanism 15B, 115B, 215B. However, the second drive unit may be provided at a position parallel to the braking direction of the first drive unit 20, above, below, or to the side, and the second drive unit may move the first drive unit 20.

[0099] In each of the above embodiments, the second drive unit 15, 115, 215 functions as a safety brake that drives the brake shoe 2 in place of the first drive unit 20. However, the second drive unit 15, 115, 215 may normally drive the brake shoe 2 by moving the first drive unit 20, and the first drive unit 20 may function as a safety brake that drives the brake shoe 2 when the second drive unit 15, 115, 215 is no longer able to drive.

[0100] In the configurations of the above embodiments, the second drive unit 15, 115, 215 may be provided so that when the first drive unit 20 presses the brake shoe 2 against the wheel and the brake shoe 2 becomes stuck in a braking state, the second drive unit 15, 115, 215 moves the first drive unit 20 in the release direction. With this configuration, when the first drive unit 20 becomes stuck while the brake shoe 2 is in a braking state, the second drive unit 15, 115, 215 can release the brake shoe 2.

[0101] In the configurations of the above embodiments, the second drive unit 15, 115, 215 may be provided so that when the first drive unit 20 sticks in the released state where the brake shoe 2 is away from the wheel, the second drive unit 15, 115, 215 moves the first drive unit 20 in the braking direction. With this configuration, when the brake shoe 2 is released and the first drive unit 20 sticks, the second drive unit 15, 115, 215 can drive the brake shoe 2 in the braking direction.

[0102] In each of the above embodiments, if an object is made up of multiple objects, the multiple objects may be integrated, and conversely, if an object is made up of a single object, it may be divided into multiple objects. Regardless of whether the objects are integrated or not, it is sufficient that the object of the invention can be achieved. [Explanation of symbols]

[0103] 1,101,201...Unit brake device 2…Bracelets 3...wheels 3A…Tread 10, 110, 210…Housing 10A...Mounting part 11...lever 11A...Proximal end 11B…Support part 11C...Tip (point of action) 12...Spindle (fulcrum) 13...Shoehead 14...Hanger 14A...Connecting pin 15, 115, 215...Second drive unit 15A, 115A, 215A…supply source 15B, 115B, 215B...Transmission mechanism 16...Nut 20...First drive unit 20A...Side 20B...Connecting pin 21...Electric motor 22...Conversion mechanism 23...Electromagnetic brake 24...Sheath stick 25...Push rod 25A...Connecting pin 26...Connection shaft (point of action) 26A...Connecting member 30...First air pressure actuator (supply source) 30A…Supply port 31...Cylinder 31A...operating chamber 32...Piston 32A...Piston rod 33...Return spring 34...Connecting pin (force point) 35...Pushback mechanism 35A...Piston 35B...Absorption spring 40...Second air pressure actuator (supply source) 41...Cylinder 41A...operating chamber 42...Piston 42A...Piston rod 43...Return spring 44...Feed screw 44A...Regulatory section 45...Nut 46...Switching section 47...Pushback mechanism 47A...Piston 47B...Absorption spring 50...Storage section 50A...First bush 50B...Second bush 50C...Guide hole 51...Arm 52...Connecting pin 53...L-shaped lever 53A...Connection recess 54...Connecting pin (force point) 55...Connecting pin (fulcrum) 56...Regulatory Department 60...Third air pressure actuator (supply source) 60A...supply port 61...Cylinder 61A...Operating chamber 62...Piston 62A...Piston rod 63...Return spring 65...Pushback mechanism 65A...Piston 65B...Absorption spring 70...Storage section 70A...Bush 72...Conversion unit 73...Oblique hole 74...Connecting shaft (force point)

Claims

1. a first drive unit that has an electric motor and a conversion mechanism that converts rotational motion of the electric motor into linear motion, and that drives the brake shoe in a braking direction and a release direction that is the opposite direction to the braking direction by the linear motion; a second drive unit that drives the brake shoe in at least one of the braking direction and the releasing direction by moving the first drive unit; Unit brake device.

2. The second driving unit includes a power supply source; a transmission mechanism that transmits power from the power supply source to the first drive unit and moves the first drive unit in the braking direction.

2. The unit brake device according to claim 1.

3. a housing that houses the first drive unit, the housing having guide holes that are aligned with the braking direction and the releasing direction; a support portion that supports the first drive portion within the housing so that the first drive portion is movable in the braking direction and the releasing direction, The transmission mechanism transmits power from the power supply source to the first drive unit through the guide hole.

3. The unit brake device according to claim 2.

4. The support portion includes a first bushing into which the first driving portion is inserted; a second bushing into which the first drive unit is inserted, the second bushing being located farther from the brake shoe in the moving direction of the first drive unit than the first bushing; 4. The unit brake device according to claim 3.

5. A restricting portion is provided on one of the inner surface of the housing and the outer surface of the first drive unit to engage with the other and restrict the movement distance of the first drive unit within a predetermined range.

5. The unit brake device according to claim 3 or 4.

6. the supply source is a pneumatic actuator having a cylinder to which compressed air is supplied and a piston that is moved by the compressed air to supply power to the transmission mechanism, the pneumatic actuator is housed in the cylinder and has a push-back mechanism that biases the piston; The push-back mechanism maintains the relative position of the piston with respect to the cylinder when a force equal to or greater than a predetermined magnitude is not applied to the first drive unit in a direction opposite to the release direction, and allows the piston to move relative to the cylinder when a force equal to or greater than the predetermined magnitude is applied.

3. The unit brake device according to claim 2.

7. The transmission mechanism includes: a coupling mechanism that couples the supply source and the first drive unit so as to be relatively movable; an elastic member that biases the connecting mechanism; a switching unit that can switch between a force-storing state in which the elastic member stores force and a release state in which the force-storing state is released, When the switching unit switches to the force-storing state, power from the supply source is transmitted to the first drive unit via the transmission mechanism, causing the first drive unit to move in the release direction, When the switching unit switches to the released state, the elastic member biases the coupling mechanism, and the first drive unit moves in the release direction by the coupling mechanism.

3. The unit brake device according to claim 2.

8. The connecting mechanism includes: a lead screw connected to the supply; a nut fitted to the feed screw and movable relative to the feed screw, The switching unit is an electromagnetic brake.

8. The unit brake device according to claim 7.

9. The transmission mechanism includes a lever having an application point connected to the first drive unit and a force point connected to the power source.

3. The unit brake device according to claim 2.

10. The levers are connected to both sides of the first driving unit and support the first driving unit.

10. The unit brake device according to claim 9.

11. The transmission mechanism includes an arm that connects the supply source and the lever.

10. The unit brake device according to claim 9.

12. the transmission mechanism includes a conversion unit that converts the output direction of the power of the supply source into the movement direction of the first drive unit by using an inclined surface, thereby moving the first drive unit.

3. The unit brake device according to claim 2.

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