Brake cylinder device

Abstract

The present invention provides a brake cylinder device capable of preventing the release of the braking force of a spring brake due to the fluid supplied to the fluid brake from being reset after the braking force of the spring brake is released. The brake cylinder device (50) includes: a fluid brake (60), a spring brake (70) and a brake release mechanism (90). For the brake cylinder device (50), in order to reduce the braking force of the spring brake (70) when the fluid brake (60) is in effect, compressed air is supplied to the spring brake (70). For the brake cylinder device (50), the area (S1) of the pressure-receiving surface (55a) that receives the compressed air supplied to the spring brake (70) is set so that after the braking force of the spring brake (70) is released by operating the brake release mechanism (90), the state in which the spring brake (70) generates the braking force will not be switched under the action of the pressure of the compressed air supplied to the spring brake (70).

Description

Technical Field

[0001] The present invention relates to a brake cylinder device capable of actuating two different brakes, namely a fluid brake and a spring brake. Background Art

[0002] For example, in the braking device for railway vehicles, there is a known brake cylinder device that can activate both a fluid brake and a spring brake (parking brake). The fluid brake is used during normal driving and is activated by compressed air, while the spring brake (parking brake) is used when the vehicle is parked for a long time and can be activated by spring force even without compressed air (for example, refer to patent documents 1 and 2).

[0003] exist Figure 8 This conventional brake cylinder device 150, whose outline is shown in FIG, has a fluid brake 160, which includes: a first pressure chamber 164, a first piston 161, a first spring 166, and an output member 151 (spindle) such as a rod or a spindle. The fluid brake 160 generates a fluid braking force by supplying compressed air from a first air source 104 to the first pressure chamber 164. In addition, the brake cylinder device 150 also has a spring brake 170, which includes a second pressure chamber 174, a second piston 171, and a second spring 176. As the compressed air in the second pressure chamber 174 is discharged, the second spring 176 pushes the second piston 171 and the output member 151, so that the spring brake 170 generates a braking force (parking braking force). Among them, Figure 8 Indicates that the spring brake 170 is in an operating state. In addition, for the spring brake 170, there is also a known structure in which the operation of the spring brake 170 is suppressed by supplying compressed air to the second pressure chamber 174 from the second air source 106 different from the first air source 104, and a double check valve is provided in the supply path of the compressed air (Figure 2 of Patent Document 2). When compressed air is not supplied to the supply path from the second air source 106, the compressed air from the first air source 104 is supplied to the first pressure chamber 164 and is also supplied to the second pressure chamber 174 via the double check valve 108. In this way, the undesirable situation that the spring brake 170 is also operated at the same time when the fluid brake 160 is operated, resulting in excessive braking force, is prevented from occurring.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 5654129

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 63-125834 Summary of the invention

[0008] Problem that the invention aims to solve

[0009] In addition, Figure 8 The above-described conventional brake cylinder device 150 is generally equipped with a brake release mechanism 190 that releases the spring brake 170 (parking brake) during its operation to allow the use of the fluid brake 160, thereby releasing the braking force of the spring brake 170. The brake release mechanism 190 includes a clutch mechanism 180 to be described below.

[0010] First, the clutch mechanism 180 is a mechanism for connecting or disconnecting the output member 151 and the second piston 171, and switching the transmission or blocking of the urging force of the spring brake 170. The clutch mechanism 180 is provided with a nut member 181, which is supported to be rotatable relative to the second piston 171 and is threadedly engaged with the output member 151. And, by changing from the state of supplying compressed air to the second pressure chamber 174 to the state of discharging compressed air from the second pressure chamber 174, the clutch 184 meshing with the nut member 181 moves relative to the output member 151 together with the second piston 171 under the urging force of the second spring 176, and becomes a connected state connecting the output member 151 and the second piston 171. On the other hand, in the state of supplying compressed air to the second pressure chamber 174, the clutch mechanism 180 becomes a non-connected state in which the connection between the output member 151 and the second piston 171 is disconnected. In the brake cylinder device 150 , when the clutch mechanism 180 is switched to the above-mentioned connected state, the nut member 181 and the concavo-convex teeth of the clutch 184 mesh with each other, and the braking force of the spring brake 170 is maintained.

[0011] The brake release mechanism 190 includes a locking rod 191, which is used to restrict / unrestrict the rotation of the clutch box 182, and the clutch box 182 supports the above-mentioned nut member 181 of the clutch mechanism 180 so that it can rotate. The rotation of the clutch box 182 is restricted by engaging the end 191a of the locking rod 191 with the latch tooth 182c provided on the clutch box 182. If the locking rod 191 can be manually released from restriction, when the locking rod 191 is pulled upward in the figure and the engagement between the above-mentioned end 191a and the latch tooth 182c of the clutch box 182 is released, the clutch box 182 can rotate while maintaining the meshing state of the nut member 181 and the clutch 184, and the clutch mechanism 180 as a whole is idling. In other words, the output member 151 and the second piston 171 can be relatively displaced. As a result, if Figure 8 As shown, the first piston 161 and the second piston 171 move to the stroke end under the urging force of the first spring 166 and the second spring 176, and the first piston 161 and the output member 151 move in the direction in which the braking force does not work, thereby releasing the braking force of the spring brake 170.

[0012] After the braking force of the spring brake 170 is released due to, for example, idle operation, the vehicle is operated without supplying compressed air to the second pressure chamber 174. Fig. 9 As shown in FIG. 1 , when compressed air is supplied from the first air source 104 to the second pressure chamber 174 via the double check valve 108, the second piston 171 is pushed in the anti-braking direction due to the large reaction force bearing area S3 of the second piston 171, and the rotation restriction of the clutch 184 by the locking rod 191, that is, the engagement between the end 191a and the latch tooth 182c is restored, and the clutch mechanism 180 is in a non-connected state. Fig.10 As shown, when the supply of compressed air from the first air source 104 is stopped and the compressed air in the second pressure chamber 174 is reduced, the second spring 176 is extended, the clutch mechanism 180 is switched to the connected state, and the spring brake 170 is restored based on the action of the second spring 176 .

[0013] However, in this case, the compressed air from the first air source 104 is supplied to utilize the fluid brake 160. Since the spring brake 170 begins to reset during this process, the spring brake 170 comes into effect after the compressed air of the fluid brake 160 is discharged.

[0014] In addition, in the above example, for ease of understanding, the structure and operation of the clutch mechanism 180 are described on the premise that the clutch mechanism 180 exists, but the same problem will occur as long as the structure includes a restriction portion (latch tooth 182c) for restricting the relative displacement between the output member 151 and the second piston 171 and a release portion (lock rod 191) for releasing the restriction of the restriction portion. That is, the existence of the clutch mechanism 180 is not essential.

[0015] The present invention has been made in view of such actual circumstances, and an object of the present invention is to provide a brake cylinder device capable of preventing the release of the braking force of the spring brake from being reset due to the fluid supplied to the fluid brake after the braking force of the spring brake is released.

[0016] Solutions for solving problems

[0017] A brake cylinder device for solving the above-mentioned problem comprises: a fluid brake which generates a braking force by being supplied with a fluid; a spring brake which generates a braking force by discharging the fluid independently of the fluid brake; and a release portion which is used to release the braking force of the spring brake, wherein the brake cylinder device supplies the fluid to the spring brake in order to reduce the braking force of the spring brake when the fluid brake is in effect, wherein a pressure-receiving area which receives the fluid supplied to the spring brake is set such that, after the braking force of the spring brake is released by operating the release portion, the spring brake will not switch to a state where the spring brake generates a braking force under the action of the pressure of the fluid supplied to the spring brake.

[0018] According to the above structure, the pressure receiving area of ​​the fluid supplied to the spring brake is set to not switch to a state where the spring brake generates a braking force. Therefore, it is possible to prevent the release of the spring brake's braking force caused by the fluid supplied to the fluid brake from being reset after the spring brake's braking force is released by the release portion.

[0019] For the above-mentioned brake cylinder device, it is preferred that the brake cylinder device includes: a first pressure chamber, which pushes a first piston for generating a braking force of the fluid brake by being supplied with the fluid; a second pressure chamber, which resists a spring force for generating a braking force of the spring brake and pushes the second piston by being supplied with the fluid; and a third pressure chamber, which is arranged to be independent of the second pressure chamber, resists the spring force of the spring brake and pushes the second piston by being supplied with the fluid for generating a braking force of the fluid brake, and the pressure area is the pressure area of ​​the fluid in the third pressure chamber at the second piston.

[0020] According to the above structure, the third pressure chamber to which the fluid supplied to the fluid brake is supplied is provided, and the pressure receiving area of ​​the third pressure chamber is set to an area that will maintain the state in which the braking force of the spring brake is released. Furthermore, if the fluid is not supplied to the second pressure chamber, the pressure of the fluid on the pressure receiving surface (area) of the third pressure chamber acts on the second piston.

[0021] In the brake cylinder device described above, it is preferable that the third pressure chamber communicates with the first pressure chamber, and the fluid for causing the fluid brake to function is supplied to the third pressure chamber via the first pressure chamber.

[0022] According to the above configuration, when the fluid is supplied to the first pressure chamber, the fluid is also supplied to the third pressure chamber, and the pressure of the fluid supplied to the fluid brake can act on the second piston.

[0023] Effects of the Invention

[0024] According to the present invention, after the braking force of the spring brake is released, the release of the braking force of the spring brake due to the fluid supplied to the fluid brake can be prevented from being reset. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a diagram showing a configuration of a unit brake having a brake cylinder device in a first embodiment of the brake cylinder device.

[0026] Figure 2 It is a partial cross-sectional view showing an enlarged structure of the brake cylinder device according to this embodiment.

[0027] Figure 3 It is a diagram showing a state in which the braking force of the spring brake of the brake cylinder device according to the embodiment is released.

[0028] Figure 4 It is a diagram showing a state after the fluid brake is actuated in the brake cylinder device of the embodiment.

[0029] Figure 5 This is a diagram showing a configuration of a unit brake having a brake cylinder device in a second embodiment of the brake cylinder device.

[0030] Figure 6 It is a diagram showing a state in which the braking force of the spring brake of the brake cylinder device according to the embodiment is released.

[0031] Figure 7 It is a diagram showing a state after the fluid brake is actuated in the brake cylinder device of the embodiment.

[0032] Figure 8 It is a diagram showing the structure of a unit brake having a conventional brake cylinder device.

[0033] Fig. 9 It is a diagram showing a state of braking force applied to a spring brake of a conventional brake cylinder device.

[0034] Fig.10 This is a diagram showing a state in which the braking force of the spring brake of the conventional brake cylinder device is released.

[0035] Description of Reference Numerals

[0036] 1. First supply path; 2. Second supply path; 4. First air source; 5. Fluid brake control device; 6. Second air source; 7. Spring brake control solenoid valve; 20. Brake swing arm; 21. Support shaft; 22. Upper end; 24. Bearing hole; 26. Spherical bearing; 28. Sleeve rod; 29. ​​Support shaft; 30. Brake pad support; 31. Brake pad; 40. Housing; 41. First upper opening; 42. Second upper opening; 43. Lower opening; 44. Wheel side wall; 45. Side wall; 50. Brake cylinder device; 51. Rod; 52. Guide column; 55. Third pressure chamber; 55a. Pressure surface; 56. Communication path; 57. Third pressure chamber; 57a. Pressure surface; 58. Central passage; 59. Balance chamber; 60. Fluid brake; 61. First piston; 62. 1st cylinder; 63, 1st port; 64, 1st pressure chamber; 65, main body; 66, 1st spring; 70, spring brake; 71, 2nd piston; 71a, clutch housing; 71b, side wall; 72, 2nd cylinder; 73, 2nd port; 74, 2nd pressure chamber; 75, main body; 76, 2nd spring; 80, clutch mechanism; 81, nut member; 81a, external teeth; 82, clutch box; 82b, clutch release spring; 82c, latch teeth; 83, bearing; 84, clutch; 84a, external teeth; 85, thrust bearing; 86, clutch box push spring; 87, clutch spring; 90, brake release mechanism; 91, locking rod; 91a, locking teeth; 92, force member; 100, unit brake; S1, S2, S3, area; W, wheel. DETAILED DESCRIPTION

[0037] (First embodiment)

[0038] Below, refer to Figure 1 to Figure 4 A first embodiment in which the brake cylinder device is embodied as a unit brake will be described.

[0039] <Overall Structure of Unit Brake 100>

[0040] Figure 1 The unit brake 100 shown is configured as a brake device for a railway vehicle. The unit brake 100 brakes the rotation of the wheel W of the vehicle by making the brake pad 31 abut against the wheel W of the vehicle. The unit brake 100 includes: a brake cylinder device 50, which is used to drive the rod 51; a brake swing rod 20, which can swing according to the movement of the rod 51 along the axial direction; and a brake pad support 30, which can move forward and backward according to the swing of the brake swing rod 20, and the brake pad 31 is installed on the brake pad support 30. The unit brake 100 includes a housing 40, which is formed in a hollow shape and is configured so that the inside thereof is connected to the atmosphere. The housing 40 is fixed to the chassis of the vehicle, etc.

[0041] <Brake lever 20>

[0042] The brake rocker arm 20 is accommodated in the housing 40. The brake rocker arm 20 is rotatably supported by a support shaft 21 mounted in the housing 40. The brake rocker arm 20 is arranged in a state extending in the up-down direction. The support shaft 21 is provided in the middle part of the brake rocker arm 20. In addition, the upper end portion 22 of the brake rocker arm 20 is rotatably supported by the rod 51. A bearing hole 24 is provided at the lower end portion of the brake rocker arm 20. A spherical bearing 26 is embedded in the bearing hole 24. A sleeve rod 28 is fixed to the inner ring of the spherical bearing 26. The sleeve rod 28 is formed in a cylindrical shape. An internal thread is formed on the inner surface of the sleeve rod 28. The internal thread of the sleeve rod 28 is threadedly engaged with the support shaft 29. Thus, the protrusion amount of the support shaft 29 relative to the sleeve rod 28 can be adjusted.

[0043] <Casing 40>

[0044] The housing 40 is formed with an upper first opening 41, an upper second opening 42, and a lower opening 43. The upper first opening 41 is formed on a wheel-side side wall 44 ( Figure 1 The brake cylinder device 50 is mounted on the housing 40 in such a manner as to block the upper first opening 41 of the housing 40. A supply path for supplying compressed air penetrates through the upper second opening 42.

[0045] The lower opening 43 is formed at the lower portion of the wheel-side side wall 44. The support shaft 29 passes through the lower opening 43 and protrudes toward the wheel side. At the top end of the support shaft 29, a brake pad support 30 is provided.

[0046] <Brake cylinder device 50>

[0047] The brake cylinder device 50 includes a rod 51 having a plurality of threads on its outer peripheral surface, and the brake rocker 20 is swung by moving the rod 51 in the axial direction.

[0048] The brake cylinder device 50 includes a fluid brake 60 for decelerating or stopping a running vehicle, a spring brake 70 used when the vehicle is parked, a clutch mechanism 80, and a brake release mechanism 90. The fluid brake 60 and the spring brake 70 are configured to operate the same rod 51. In addition, the brake release mechanism 90 corresponds to a release portion.

[0049] <Fluid brake 60>

[0050] The fluid brake 60 is operated by compressed air as a fluid. The fluid brake 60 has a first piston 61 connected to the rod 51. The first pressure chamber 64 and the first spring 66 act on the first piston 61 in opposite directions. For the fluid brake 60, the first piston 61 is moved in the direction of generating braking force, that is, the braking direction (arrow X1 direction) along the rod 51 by supplying compressed air to the first pressure chamber 64. The fluid brake 60 includes a bottomed cylindrical first cylinder 62, and the first piston 61 is slidably accommodated in the first cylinder 62.

[0051] The first cylinder 62 is provided with a first port 63 for supplying and discharging compressed air. A first pressure chamber 64 communicating with the first port 63 is formed in the first cylinder 62. The first pressure chamber 64 is formed by the first piston 61 and the first cylinder 62. In accordance with a predetermined braking operation, compressed air is supplied or discharged to or from the first pressure chamber 64. The first pressure chamber 64 is divided and formed in the anti-braking direction relative to the clutch box 82 described later.

[0052] <Spring brake 70>

[0053] The spring brake 70 includes a second piston 71 through which the rod 51 passes, and the second piston 71 is configured to be movable along the axial direction of the rod 51. The second pressure chamber 74 and the second spring 76 act on the second piston 71 in opposite directions. The spring brake 70 changes from a state in which compressed air as a fluid is supplied to the second pressure chamber 74 to a state in which compressed air as a fluid is discharged from the second pressure chamber 74, and the second piston 71 moves in a braking direction (arrow X1 direction) under the action of the biasing force of the second spring 76. The spring brake 70 includes a second cylinder 72 in which the second piston 71 is slidably accommodated.

[0054] The second cylinder 72 has a main body 75 disposed on the outer peripheral side of the main body 65 of the first cylinder 62. In addition, the second piston 71 is configured to be able to abut against the end of the main body 65 of the first cylinder 62. The second cylinder 72 is fixed to the housing 40. A second pressure chamber 74 for supplying and discharging compressed air through the second port 73 is formed between the second piston 71 and the wheel-side side wall 44 of the housing 40. The second pressure chamber 74 is formed by the second piston 71, the housing 40, and the second cylinder 72. In addition, the second pressure chamber 74 is arranged opposite to the first pressure chamber 64 and has an annular shape. The second pressure chamber 74 is divided and formed on the outer side of the clutch box 82 described later.

[0055] A second spring 76 is disposed on the side opposite to the second pressure chamber 74 with respect to the second piston 71. The second spring 76 is disposed between the main body 65 of the first cylinder 62 disposed on the inner side and the main body 75 of the second cylinder 72 disposed on the outer side, and is disposed on the outer side of the first pressure chamber 64 in a manner concentric with the first pressure chamber 64. The second spring 76 is compressed when receiving compressed air in the second pressure chamber 74. Normally, compressed air is introduced into the second pressure chamber 74, and the second spring 76 is compressed, but due to a predetermined braking operation such as parking, the compressed air in the second pressure chamber 74 is discharged, and under the action of the spring force of the second spring 76, the rod 51 moves in the braking direction (the direction of the arrow X1).

[0056] like Figure 2 As shown in the enlarged cross section in FIG. 1 , the second piston 71 has a clutch housing portion 71a whose central portion protrudes toward the first piston 61. The clutch mechanism 80 is housed inside the clutch housing portion 71a. A side wall 71b extending along the axial direction of the rod 51 is formed at the end of the second piston 71 on the side close to the rod 51. A thrust bearing 85 described later is held on the side wall 71b.

[0057] The first spring 66 is arranged between the first piston 61 and the second piston 71. The first spring 66 is used to push the first piston 61 in the anti-braking direction (arrow X2 direction) that contracts the first pressure chamber 64, and is compressed by the compressed air when compressed air is supplied to the first pressure chamber 64. Normally, compressed air is not supplied to the first pressure chamber 64, so the rod 51 moves in the anti-braking direction (arrow X2 direction) under the action of the spring force of the first spring 66. Supplying compressed air to the first pressure chamber 64 due to a prescribed braking operation causes the rod 51 to move in the braking direction (arrow X1 direction). When the compressed air in the first pressure chamber 64 is discharged due to a prescribed brake release operation, the rod 51 returns to its initial state under the action of the spring force of the first spring 66.

[0058] like Figure 1 As shown, the brake cylinder device 50 includes a third pressure chamber 55, which is divided into a pressure chamber separated from the second pressure chamber 74. The compressed air supplied to the first pressure chamber 64 causes the second piston 71 to overcome the force of the second spring 76 and move in the anti-braking direction (X2 direction).

[0059] The second pressure chamber 74 is arranged close to the rod 51, and the third pressure chamber 55 is arranged farther from the rod 51 than the second pressure chamber 74. That is, the third pressure chamber 55 is provided as a circular annular space closer to the outer periphery of the brake cylinder device 50 than the second pressure chamber 74. The compressed air supplied to the first pressure chamber 64 is supplied to the third pressure chamber 55 via the communication passage 56. The communication passage 56 is formed along the edge of the brake cylinder device 50.

[0060] The area S1 of the pressure receiving surface 55a of the third pressure chamber 55 is set to be within the range of the area that can maintain the released state even if the fluid brake 60 is actuated in the released state in which the relative displacement between the rod 51 and the second piston 71 is allowed by operating the lock lever 91, in other words, is set to be smaller than the area where the spring brake 70 generates the braking force. That is, the area S1 of the pressure receiving surface 55a that receives the compressed air supplied to the spring brake 70 is set so as not to switch to the state where the spring brake 70 generates the braking force.

[0061] <Clutch mechanism 80>

[0062] The clutch mechanism 80 allows the nut member 81 to rotate relative to the rod 51 when the fluid brake 60 is driven, and restricts the nut member 81 from rotating relative to the rod 51 when the spring brake 70 is driven. The clutch mechanism 80 is arranged in a region that does not interfere with the first pressure chamber 64 and the second pressure chamber 74. That is, when the second piston 71 moves in the braking direction, the clutch mechanism 80 is in a connected state in which the rod 51 and the second piston 71 are connected, and when compressed air for resisting the biasing force of the second spring 76 is supplied to the second pressure chamber 74, the clutch mechanism 80 is in a non-connected state in which the connection between the rod 51 and the second piston 71 is released.

[0063] The clutch mechanism 80 includes: a nut member 81; a clutch box 82, the nut member 81 is accommodated inside the clutch box 82; a bearing 83 that supports the nut member 81 so as to be rotatable relative to the clutch box 82; and a clutch 84 that is arranged opposite to the nut member 81. The clutch mechanism 80 also includes: a thrust bearing 85 that supports the clutch box 82 so as to be rotatable relative to the second piston 71; a clutch box pressing spring 86; and a clutch spring 87. The clutch mechanism 80 is usually locked by a lock rod 91 so as not to rotate.

[0064] The nut member 81 is threadedly coupled to the rod 51 in a rotatable manner. Furthermore, the nut member 81 is supported by the bearing 83 so as to be rotatable relative to the clutch box 82. Thus, the nut member 81 rotates according to the relative movement of the rod 51 and the clutch box 82. Furthermore, the nut member 81 is supported so as to be movable toward the anti-braking direction (arrow X2 direction) together with the clutch box 82. Furthermore, an external tooth 81a that meshes with the external tooth 84a of the clutch 84 is formed at a portion of the nut member 81 that is opposite to the clutch 84.

[0065] When the external teeth 81a of the nut member 81 engage with the external teeth 84a of the clutch 84, movement in the braking direction (arrow X1 direction) and the anti-braking direction (arrow X2 direction) relative to the clutch box 82 is allowed, but displacement in the rotational direction around the axis of the rod 51 is restricted.

[0066] The clutch box 82 is formed as a cylindrical member in which the nut member 81 and the clutch 84 are arranged. The clutch 84 slides parallel to the axial direction of the rod 51 while the displacement of the clutch box 82 in the rotation direction centered on the axial direction of the rod 51 is restricted. That is, the clutch box 82 supports the clutch 84 so that it can slide along the moving direction of the second piston 71.

[0067] In addition, the clutch box 82 is provided with a clutch release spring 82b, which urges the clutch 84 in a direction away from the nut member 81. The clutch release spring 82b is provided on the inner side (rod 51 side) of the clutch box 82 and on the outer side of the nut member 81 and the clutch 84. In addition, a clutch box pressing spring 86 is provided between the clutch box 82 and the second piston 71.

[0068] The clutch 84 is a cylindrical member, and is provided around the rod 51 opposite to the nut member 81. The end of the clutch 84 in the anti-braking direction (arrow X2 direction) is rotatably supported by the second piston 71 via a thrust bearing 85. Thus, when the second piston 71 moves in the braking direction (arrow X1 direction) relative to the rod 51 under the biasing force of the second spring 76, the clutch 84 also moves in the braking direction (arrow X1 direction) relative to the rod 51 together with the second piston 71 via the second piston 71 and the thrust bearing 85.

[0069] The clutch mechanism 80 is arranged inside the second pressure chamber 74. By changing from a state of supplying compressed air to the second pressure chamber 74 to a state of discharging compressed air from the second pressure chamber 74, under the action of the biasing force of the second spring 76, the clutch 84 moves in the braking direction (arrow X1 direction) relative to the rod 51 together with the second piston 71 and meshes with the nut member 81 (the external teeth 81a of the nut member 81 mesh with the external teeth 84a of the clutch 84), and the clutch mechanism 80 is in a connected state in which the rod 51 and the second piston 71 are connected.

[0070] On the other hand, when compressed air is supplied to the second pressure chamber 74, the clutch 84 is away from the nut member 81 (the external teeth 81a and the external teeth 84a are not meshed), and the nut member 81 is in a state of free rotation. Therefore, when compressed air is supplied to the second pressure chamber 74, the clutch mechanism 80 is in a non-connected state that releases the connection between the rod 51 and the second piston 71.

[0071] <Brake release mechanism 90>

[0072] The brake release mechanism 90 includes a latch tooth 82c of the clutch box 82, which is a restriction portion for restricting the relative displacement between the rod 51 and the second piston 71 when the clutch mechanism 80 is in a connected state, and a lock rod 91, which is a release portion for manually releasing the restriction of the latch tooth 82c. The brake release mechanism 90 releases the restriction of the latch tooth 82c by operating the lock rod 91 to allow the relative displacement between the rod 51 and the second piston 71, thereby releasing the braking force of the spring brake 70. In addition, the brake release mechanism 90 supplies compressed air to the second pressure chamber 74 until the restriction of the latch tooth 82c is restored, thereby restoring the restriction of the relative displacement between the rod 51 and the second piston 71 by the latch tooth 82c.

[0073] The latching tooth 82c is provided on the outer peripheral surface of the end portion of the clutch box 82 in the braking direction (the direction of the arrow X1). The base end portion of the locking rod 91 is provided with a locking tooth 91a, which is configured to be engaged with the latching tooth 82c. The locking rod 91 is biased by the biasing member 92 in the direction in which the locking tooth 91a and the latching tooth 82c are engaged, and the locking rod 91 is pulled up to release the engagement between the latching tooth 82c and the locking tooth 91a, so that the clutch box 82 can rotate. The clutch box 82 is configured to be unlockable in order to manually release the spring brake 70 when the compressed air in the second pressure chamber 74 is discharged due to retention and the second spring 76 of the spring brake 70 is in an extended state (a state in which the spring brake 70 is actuated).

[0074] <Rod 51>

[0075] The rod 51 passes through the upper first opening 41. The upper end portion 22 of the brake rocker 20 is a portion that receives force from the rod 51 as the rod 51 is driven, and is inserted between the wall portions of the rod 51.

[0076] A guide post 52 is inserted into the inner side of the rod 51. The base end of the guide post 52 is as shown in FIG. Figure 1 As shown, the rod 51 is fixed to the side wall 45 of the housing 40 on the opposite side to the wheel, and is arranged coaxially with the rod 51.

[0077] <Compressed air supply path>

[0078] like Figure 1 As shown, the brake cylinder device 50 includes a first supply path 1 for supplying compressed air to the first pressure chamber 64 , and a second supply path 2 for supplying compressed air to the second pressure chamber 74 .

[0079] The first supply passage 1 supplies compressed air from the first air source 4, and the supply and discharge of the compressed air to and from the first pressure chamber 64 are controlled by the fluid brake control device 5. The first supply passage 1 is connected to the first port 63. The fluid brake control device 5 changes the supply amount of compressed air according to the braking operation of the vehicle to change the braking amount.

[0080] The second supply path 2 supplies compressed air from a second air source 6 different from the first air source 4, and controls the supply of compressed air to the second pressure chamber 74 based on the control of the spring brake control solenoid valve 7. The second supply path 2 is connected to the second port 73. The spring brake control solenoid valve 7 releases the brake of the second spring 76 by supplying compressed air when the parking brake of the vehicle is not operated. On the other hand, for the spring brake control solenoid valve 7, when the parking brake of the vehicle is operated, the compressed air is discharged from the spring brake control solenoid valve 7, and the braking effect is exerted by the second spring 76.

[0081] <Action>

[0082] Next, the operation of the unit brake 100 will be described.

[0083] First, refer to Figure 1 Indicates the vehicle is not braked. Figure 1 In the state shown, the unit brake 100 is controlled by the fluid brake control device 5 so that compressed air is not supplied from the first air source 4 to the first pressure chamber 64 via the first port 63. In addition, the compressed air in the first pressure chamber 64 is discharged from the fluid brake control device 5 via the first port 63. Therefore, the first piston 61 is urged in the anti-braking direction (arrow X2 direction) by the first spring 66, and the first piston 61 is brought into contact with the bottom of the first cylinder 62.

[0084] On the other hand, Figure 1In the state shown, the unit brake 100 supplies compressed air from the second air source 6 to the second pressure chamber 74 via the second port 73 based on the control of the spring brake control solenoid valve 7. Therefore, the state is such that the second piston 71 overcomes the force of the second spring 76 and moves in the anti-braking direction (arrow X2 direction) under the action of the compressed air supplied to the second pressure chamber 74. In this state, as shown in FIG. Figure 2 As shown, the external teeth 81 a of the nut member 81 and the external teeth 84 a of the clutch 84 are not meshed with each other, and a gap is formed.

[0085] Next, refer to Figure 3 The state in which the vehicle is braked by the spring brake 70 will be described.

[0086] When the spring brake 70 is activated, for example, the spring brake 70 is activated as a parking brake when the rail vehicle is completely stopped by activating the fluid brake 60. The spring brake 70 is activated by discharging compressed air from the second pressure chamber 74 based on the control of the spring brake control solenoid valve 7.

[0087] When the compressed air supplied to the second pressure chamber 74 is discharged, the second piston 71 begins to move in the braking direction (direction of arrow X1) under the action of the force of the second spring 76. At this time, the clutch 84 begins to rotate freely on the thrust bearing 85 supported by the second piston 71 and moves in the braking direction relative to the rod 51 together with the second piston 71. In addition, at this time, the clutch 84 moves in the braking direction relative to the clutch box 82. And, if the second piston 71 begins to move relative to the rod 51 together with the clutch 84 in this way, the clutch 84 comes into contact with the nut member 81. That is, Figure 2 The external teeth 81 a of the nut member 81 shown are meshed with the external teeth 84 a of the clutch 84 , and the rotation of the nut member 81 is stopped.

[0088] As described above, the clutch mechanism 80 is changed from the non-connected state to the connected state by the meshing of the nut member 81 and the clutch 84. In this connected state, the rotation of the nut member 81 stops, so the second piston 71 is moved in the braking direction (arrow X1 direction) by the force of the second spring 76, and the first piston 61 and the rod 51 are forced by the clutch 84 and the nut member 81, and the first piston 61 and the rod 51 are kept in the state of moving in the braking direction. That is, the spring brake 70 is kept in the state of acting and the spring braking force is exerted.

[0089] Next, refer to Figure 3 A case where the brake is manually released from a state where the vehicle is braked by the spring brake 70 will be described.

[0090] like Figure 3As shown, when the vehicle is braked by the spring brake 70 and the brake is released manually by the lock rod 91, the clutch box 82 can rotate while maintaining the meshing state of the nut member 81 and the clutch 84, and the clutch mechanism 80 as a whole is idle. As a result, the first piston 61 moves to the end of the stroke under the urging force of the first spring 66, and the second piston 71 moves to the end of the stroke under the urging force of the second spring 76, and the first piston 61 and the rod 51 move in the anti-braking direction (X2 direction), so that the braking force of the spring brake 70 is released.

[0091] Then, if Figure 4 As shown, even if air leakage occurs in the second supply path 2 later, the fluid brake control device 5 supplies compressed air from the first air source 4 to the first pressure chamber 64 according to the braking operation of the vehicle, and the compressed air supplied to the first pressure chamber 64 is also supplied to the third pressure chamber 55 via the communication path 56. The area S1 of the pressure receiving surface 55a of the third pressure chamber 55 is set to be within the range of the area that will maintain the release state even if the fluid brake 60 is actuated, in other words, it is set to be smaller than the area where the spring brake 70 generates the braking force, so that the release state is maintained even if the fluid brake 60 is actuated. Therefore, it is possible to prevent the braking force of the spring brake 70 from being superimposed on the braking force of the fluid brake 60 after the double check valve is omitted and the spring brake 70 is manually released. Furthermore, when the fluid brake 60 is actuated, the second piston 71 can be kept in a state of being forced and moved in the reverse braking direction (X2 direction) in order to overcome the force of the second spring 76, thereby preventing the fluid brake 60 and the spring brake 70 from actuating simultaneously and causing excessive braking by both the fluid braking force and the spring braking force to take effect.

[0092] As described above, according to this embodiment, the following effects can be obtained.

[0093] (1) The area S1 of the pressure receiving surface 55a receiving the compressed air supplied to the spring brake 70 is set so as not to switch to a state where the spring brake 70 generates a braking force. Therefore, after the braking force of the spring brake 70 is released by the brake release mechanism 90, the release of the braking force of the spring brake 70 due to the compressed air supplied to the fluid brake 60 can be prevented from being reset.

[0094] (2) The third pressure chamber 55 to which the compressed air supplied to the fluid brake 60 is supplied is provided, and the area S1 of the pressure receiving surface 55a of the third pressure chamber 55 is set to an area capable of maintaining the state in which the braking force of the spring brake 70 is released. Furthermore, if the compressed air is not supplied to the second pressure chamber 74, the pressure of the compressed air on the pressure receiving surface (area) of the third pressure chamber 55 acts on the second piston 71.

[0095] (3) By supplying compressed air to the first pressure chamber 64 , compressed air is also supplied to the third pressure chamber 55 , so that the pressure of the compressed air supplied to the fluid brake 60 can act on the second piston 71 .

[0096] (Second embodiment)

[0097] Below, refer to Figure 5 to Figure 7 A second embodiment in which the brake cylinder device is implemented as a unit brake will be described. The brake cylinder device of this embodiment is different from the first embodiment in that a third pressure chamber is arranged at an inner side. The following description will focus on the differences from the first embodiment.

[0098] like Figure 5 As shown, the brake cylinder device 50 includes a third pressure chamber 57, which is a pressure chamber divided and formed to be separated from the second pressure chamber 74, and the second piston 71 is moved in the counter-braking direction (X2 direction) by the compressed air supplied to the first pressure chamber 64 to overcome the force of the second spring 76. In addition, the third pressure chamber 57 functions as a counter-braking pressure imparting unit. The third pressure chamber 57 is connected to the balance chamber 59 from the central passage 58 of the second piston 71.

[0099] The third pressure chamber 57 is arranged on the inner side close to the rod 51, and the second pressure chamber 74 is arranged on the outer side away from the rod 51 than the third pressure chamber 57. That is, the second pressure chamber 74 is provided at a position closer to the outer periphery of the brake cylinder device 50 than the third pressure chamber 57, and is an annular space. The compressed air supplied to the first pressure chamber 64 is supplied to the third pressure chamber 57. The first pressure chamber 64 and the third pressure chamber 57 are directly connected.

[0100] The area S2 obtained by deducting the balance chamber 59 from the pressure-receiving surface 57a of the third pressure chamber 57 is set within the following range: when the relative displacement between the rod 51 and the second piston 71 is released by operating the locking rod 91, the area is maintained within the released state even if the fluid brake 60 is actuated.

[0101] <Action>

[0102] Next, refer to Figure 6 and Figure 7 The operation of the unit brake 100 will be described.

[0103] like Figure 6As shown, when the vehicle is braked by the spring brake 70 and the brake is released manually, the clutch box 82 can rotate while maintaining the meshing state of the nut member 81 and the clutch 84, and the clutch mechanism 80 as a whole idles. As a result, the first piston 61 moves to the end of the stroke under the action of the first spring 66, and the second piston 71 moves to the end of the stroke under the action of the second spring 76, and the first piston 61 and the rod 51 move in the anti-braking direction (X2 direction), so that the braking force of the spring brake 70 is released.

[0104] Then, if Figure 7 As shown, even if air leakage occurs in the second supply path 2 later, the fluid brake control device 5 supplies compressed air from the first air source 4 to the first pressure chamber 64 according to the braking operation of the vehicle, and the compressed air supplied to the first pressure chamber 64 is also supplied to the third pressure chamber 57. The area S2 obtained by deducting the balance chamber 59 from the pressure receiving surface 57a of the third pressure chamber 57 is set to be within the range of the area that can maintain the release state even if the fluid brake 60 is actuated, so the release state can be maintained even if the fluid brake 60 is actuated. Therefore, it is possible to prevent the braking force of the spring brake 70 from being superimposed on the braking force of the fluid brake 60 after the double check valve is omitted and the braking force of the spring brake 70 is manually released. Furthermore, when the fluid brake 60 is actuated, the second piston 71 can be maintained in a state where it overcomes the force of the second spring 76 and is forced in the reverse braking direction (X2 direction) to move it, thereby preventing the fluid brake 60 and the spring brake 70 from actuating simultaneously and causing excessive braking by both the fluid braking force and the spring braking force to take effect.

[0105] As described above, according to this embodiment, it is possible to obtain the same effects as those of (1) and (2) of the first embodiment.

[0106] In addition, the above-mentioned embodiments can also be implemented in the following aspects obtained by appropriately changing the above-mentioned embodiments.

[0107] In the above-mentioned embodiment, the braking force of the spring brake 70 can be released either manually or mechanically.

[0108] In each of the above-mentioned embodiments, the nut member and the latch may be installed interchangeably.

[0109] In the above-mentioned embodiments, the unit brake 100 is used in which the driving of the rod 51 by the brake cylinder device 50 applies the braking force to the brake pad 31 via the brake swing arm 20. However, a unit brake may be used in which the driving of the first piston by the brake cylinder device 50 applies the braking force to the brake pad 31 via a wedge.

[0110] In each of the above-mentioned embodiments, compressed air is used as the fluid, but oil may be used instead of the compressed air.

[0111] It is obvious to those skilled in the art that the present invention can be embodied in other unique ways without departing from the scope of its technical ideas. For example, a part of the components and features described in the embodiment (or one or more of them) may be omitted. The scope of the present invention should be determined with reference to the attached claims and the entire scope of equivalents granted by the claims.

Claims

1. A brake cylinder device, The brake cylinder device comprises: Fluid brakes, which generate braking force by being supplied with fluid; a spring brake that generates braking force by discharging the fluid independently of the fluid brake; as well as a release portion for releasing the braking force of the spring brake, In order to reduce the braking force of the spring brake when the fluid brake takes effect, the brake cylinder device supplies the fluid to the spring brake, wherein: The brake cylinder device also includes: a first pressure chamber which, when supplied with the fluid, presses a first piston for generating a braking force of the fluid brake; a second pressure chamber which, when supplied with the fluid, resists a spring force generating a braking force of the spring brake and pushes a second piston; and a third pressure chamber which is connected to the first pressure chamber and is independent of the second pressure chamber, and which resists the spring force of the spring brake and pushes the second piston by being supplied with the fluid for generating the braking force of the fluid brake via a communication path which is always connected to the first pressure chamber, The pressure receiving area of ​​the fluid in the third pressure chamber at the second piston is set so that after the braking force of the spring brake is released by operating the release portion, the spring brake will not switch to a state where the spring brake generates braking force due to the pressure of the fluid supplied to the spring brake.

2. A brake cylinder device, The brake cylinder device comprises: Fluid brakes, which generate braking force by being supplied with fluid; a spring brake that generates braking force by discharging the fluid independently of the fluid brake; as well as a release portion for releasing the braking force of the spring brake, In order to reduce the braking force of the spring brake when the fluid brake takes effect, the brake cylinder device supplies the fluid to the spring brake, wherein: The brake cylinder device also includes: a first pressure chamber which presses a first piston for generating a braking force of the fluid brake by being supplied with the fluid; a second pressure chamber which, when supplied with the fluid, resists a spring force generating a braking force of the spring brake and pushes a second piston; and a third pressure chamber which is directly connected to the first pressure chamber without being connected via a connecting passage and is independent of the second pressure chamber, and which resists the spring force of the spring brake and pushes the second piston by the fluid for generating the braking force of the fluid brake which is directly supplied from the first pressure chamber. The pressure receiving area of ​​the fluid in the third pressure chamber at the second piston is set so that after the braking force of the spring brake is released by operating the release portion, the spring brake will not switch to a state where the spring brake generates braking force due to the pressure of the fluid supplied to the spring brake.

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