JP4773328B2 - Brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brake system capable of inhibiting outside air from entering the inside of the brake system with a simple and low cost construction. <P>SOLUTION: The brake system 1 for operating a drive mechanism section 20 by a cylinder device 10 and braking rotation of wheels comprises a drive mechanism chamber 31 communicating with a rod chamber 16 and housing the drive mechanism section 20 driven through a piston rod 13, and a variable volume chamber 47 communicating with the drive mechanism chamber 31 and formed to be variable in volume, wherein the variable volume chamber 47 has the volume varying so that the volume is increased when a piston 12 is displaced in a direction in which the volume of the rod chamber 16 is decreased and the volume is decreased when the piston 12 is displaced in a direction in which the volume of the rod chamber 16 is increased. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a brake device that operates a drive mechanism using a cylinder device to brake wheel rotation.

  Conventionally, in an air brake device for a railway vehicle, in order to prevent rainwater from entering the drive mechanism portion and causing rust generation, the drive mechanism portion is covered with a waterproof case. However, since it is difficult to keep the inside of the waterproof case completely sealed, it is difficult to prevent the intrusion of the outside air into the waterproof case even if rainwater intrusion is prevented. Therefore, for example, when passing through a tunnel in a cold district or the like, the air in the tunnel warmer than outside the tunnel flows into the waterproof case, and moisture contained in the air is condensed in the waterproof case. There was a problem. Patent Document 1 discloses a dew condensation prevention device for preventing dew condensation in such a waterproof case. This anti-condensation device keeps the air pressure inside the waterproof case slightly higher than the outside air pressure by constantly supplying dry compressed air into the waterproof case little by little, and prevents the outside air from flowing into the case. To do.

Japanese Utility Model Publication 2-92375

  However, the dew condensation prevention device described in Patent Document 1 has a problem that an air compressor, a dehumidifying device, and the like are required to produce dry compressed air, resulting in an increase in manufacturing cost. In addition, a large installation space is required, the configuration is complicated, and maintenance costs may increase. Although it is conceivable to use dry compressed air for operating the brake device instead of providing a dedicated air compressor or the like, the consumption of dry compressed air in the entire vehicle increases. As a result, the capacity of the air compressor and the tank for storing the dry compressed air must be increased, resulting in problems of cost and installation space.

  In view of the above circumstances, an object of the present invention is to provide a brake device that can suppress the outside air from entering the brake device with a simple and inexpensive structure.

Means and effects for solving the problems

  The present invention relates to a brake device that operates a drive mechanism using a cylinder device to brake wheel rotation. And the brake device concerning the present invention has the following some features in order to achieve the above-mentioned object. That is, the brake device of the present invention includes the following features alone or in combination as appropriate.

  A first feature of a brake device according to the present invention for achieving the above object is a cylinder device comprising a cylinder, a piston that slides along the inner wall of the cylinder, and a piston rod that moves with the piston. In the brake device that operates the drive mechanism unit using the brake to brake the rotation of the wheel, the rod chamber located on the piston rod side in the cylinder communicates with the rod chamber and is driven through the piston rod. A drive mechanism chamber that houses the drive mechanism section, and a volume variable chamber that communicates with the drive mechanism chamber and is configured to be variable in volume. The volume variable chamber includes the rod chamber The volume increases when the piston is displaced in the direction in which the volume of the rod decreases, and the piston changes in the direction in which the volume of the rod chamber increases. As the volume decreases upon is that the volume is changed.

  According to this configuration, when the brake operation is performed, if the volume of the rod chamber is increased due to sliding of the piston of the cylinder device, the volume of the variable volume chamber decreases. And the change of the volume of the space (hereinafter referred to as the device internal space) formed by the variable volume chamber is reduced. Further, when the volume of the rod chamber is changed so as to decrease, the volume of the variable volume chamber decreases, so that the change in the volume of the device internal space is reduced. Thus, since the volume variable chamber changes the volume so as to keep the volume of the apparatus internal space substantially constant, it is possible to suppress a change in the atmospheric pressure of the apparatus internal space. Thereby, it can suppress that external air penetrate | invades into apparatus interior space.

  In order to prevent dew condensation in the waterproof case, it is also conceivable to have a structure in which the inside of the case is completely sealed and the pressure difference between the inside and outside of the case can be withstood. However, the brake device transmits the driving force from the drive mechanism part in the case to the control device outside the case, and it is difficult to seal the drive part to withstand the pressure difference between the inside and outside of the case, which greatly increases the cost. In addition, there is a risk that the maintenance cost will increase to check the sealing performance. In this regard, according to the configuration having the first feature, it can be implemented at low cost, and since the change in the atmospheric pressure in the internal space of the apparatus is suppressed, complete sealing is not necessarily required, so that the maintenance cost is excessively high. Without being effective.

  A second feature of the brake device according to the present invention is that the volume of the variable volume chamber changes due to an action of an atmospheric pressure inside the variable volume chamber and a force that the variable volume chamber receives from the outside. It is.

  According to this configuration, the fact that the volume of the device internal space changes due to the driving of the piston and the atmospheric pressure changes can be used for the volume changing operation of the variable volume chamber. The configuration to be changed can be simplified as compared with, for example, a case where a separate driving force is required.

  A third feature of the brake device according to the present invention is that the volume variable chamber can change in volume beyond the volume of the rod chamber that can be changed by sliding of the piston.

  According to this configuration, the variable volume chamber can change in volume as much as the change in volume of the rod chamber, so that the volume of the internal space of the device becomes constant even when the stroke of the piston changes due to wear of the control wheel. Can be driven. Thereby, it can suppress more reliably that external air penetrate | invades into the said apparatus internal space.

  The fourth feature of the brake device according to the present invention is that the variable volume chamber is formed using a member having a bellows structure on a side surface.

  According to this configuration, it is possible to ensure the sealing performance of the variable volume chamber with a simple structure and to improve the durability.

  A fifth feature of the brake device according to the present invention is that the variable volume chamber is provided above the drive mechanism chamber.

  According to this configuration, since the variable volume chamber is located above the brake device, a space in the horizontal direction for attaching the brake device to the vehicle can be reduced. Further, since it is difficult to receive an impact from the road surface side (downward) during traveling, it is difficult to break down and the frequency of maintenance can be reduced.

  Further, a sixth feature of the brake device according to the present invention is that the variable volume chamber is installed in a casing forming the drive mechanism chamber.

  According to this configuration, it is not necessary to separately attach a casing for forming the variable volume chamber, and the number of parts for forming the brake device can be reduced. In addition, since the space in the casing that forms the drive mechanism chamber can be used effectively, the brake device can be reduced in size.

  Further, a seventh feature of the brake device according to the present invention is that the member forming the variable volume chamber is biased in a direction of decreasing the volume by an elastic body.

  According to this configuration, the variable volume chamber is easily shifted so that the volume decreases. Thereby, since it can suppress that the volume of the said apparatus interior space becomes large too much, it becomes possible to suppress that the atmospheric | air pressure of the said apparatus interior space becomes lower than an external pressure. Thereby, it is possible to further suppress the outside air from entering the internal space of the apparatus.

  An eighth feature of the brake device according to the present invention is that the drive mechanism portion includes a lever that is swingably fixed to a casing forming the drive mechanism chamber via a support shaft, and one end of the lever is provided. Is connected to the piston rod, and the other end is connected to a push rod for moving the restrictor forward and backward, and the cylinder device is driven to swing the lever through the piston rod to thereby push the push rod. Is to move forward and backward to exert braking force.

  According to this configuration, a braking operation can be performed by the action of the lever, and a large braking force can be applied with a small force. In general, when the brake action is performed using the lever action, the displacement amount on the force point side (piston rod side) is larger than the displacement amount on the action point side (pushing rod, control wheel side), and the internal space of the device The volume change is likely to occur, and intrusion of outside air into the internal space of the apparatus tends to be a problem. In this respect, the provision of the first feature makes it possible to perform a braking operation while suppressing the volume change of the internal space of the apparatus and to suppress the intrusion of outside air into the internal space of the apparatus. is there.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a side partial cross-sectional view of a tread brake type railway vehicle brake device according to a first embodiment of the present invention in a brake non-operating state. FIG. 2 is a diagram illustrating a brake operation state of the brake device illustrated in FIG. 1.

  A brake device 1 shown in FIG. 1 is a tread brake type basic brake device that exerts a braking force by pressing a control member from one side against a tread surface 3a of a wheel 3 of a traveling railway vehicle. The brake device 1 is installed for each wheel of the railway vehicle, and is fixed to a bogie frame of the railway vehicle by a fixing member such as a bolt (not shown), and controls the cylinder device 10 and the driving force of the cylinder device 10. A drive mechanism 20 for transmitting to the wheel to brake the rotation of the wheel 3, a first casing 30 for housing the drive mechanism 20, and a space in the first casing 30 (hereinafter referred to as drive mechanism chamber). And a second casing portion 40 that forms a space communicating with the second casing portion 40.

  The cylinder device 10 is an air cylinder device that is driven by supplying compressed air, and includes a cylinder 11, a piston 12 that slides along the inner wall of the cylinder 11, and a piston rod 13 that moves with the piston 12. And. The cylinder 11 is formed in a cylindrical shape opened on only one side, and the opening side is attached to the wall surface of the first casing portion 30. An opening 30a is formed in the wall surface of the first casing portion 30 where the cylinder 11 is installed, and the piston rod 13 is inserted into the opening 30a so as to reciprocate. The cylinder 11 is partitioned into a pressure chamber 15 located on the end face side where the compressed air supply port is formed and a rod chamber 16 located on the piston rod 13 side, with the piston 12 interposed therebetween. The rod chamber 16 is provided with an urging spring 14 between the piston 12 and the wall surface of the first casing portion 30 to urge the piston 12 toward the pressure chamber 15 (supply port 11a). Yes.

  The drive mechanism unit 20 is a mechanism for transmitting the driving force transmitted from the cylinder device 10 via the piston rod 13 to the control device 51 according to this principle. The lever 21, the connecting pin 22, the fulcrum pin 23, the push rod 24, a gap adjusting unit 25, and the like. And the circumference | surroundings of the said drive mechanism part 20 are covered with the 1st casing part 30 fixed with respect to the trolley | bogie of the railway vehicle. The first casing portion 30 is formed in a box shape extending vertically downward from the bogie frame of the railway vehicle. An opening 30a for reciprocating the piston rod 13 and a push rod 24 are reciprocally driven on the surrounding wall surface. An opening 30b for opening and an opening 30c for installing the second casing portion 40 are formed.

  The lever 21 is rotatably installed with respect to the first casing part 30 via a fulcrum pin 23, and one end of the lever 21 is rotatably connected to the piston rod 13 via a connecting pin 22. Further, a concave spherical through hole 21 a is formed on the other end (the push rod 24 side) of the lever 21 on the side close to the fulcrum pin 23. The push rod 24 is provided via a convex spherical bearing portion 25 b fitted into the spherical through hole 21 a, and one end portion of the push rod 24 is attached to the gap adjusting portion 25.

  The side of the push rod 24 that protrudes from the first casing portion 30 is formed to be bent in a substantially L shape, and the other end side is formed with a male screw portion 24a. The clearance adjustment unit 25 is a cylindrical member that adjusts the distance between the control device 51 and the wheel tread surface 3 a, and an internal thread portion 25 a that meshes with the external thread portion 24 a of the push rod 24 is formed on the inner peripheral portion of the clearance adjustment portion 25. Is formed.

  When the stroke of the push rod 24 becomes insufficient due to wear of the restrictor 51, the screw adjusting amount of the male screw portion 24a and the female screw portion 25a is adjusted by the gap adjusting portion 25, and the stroke of the push rod 24 changes to change the restrictor 51 and the wheel. The space between the tread surface 3a can be reduced. In the present embodiment, when the stroke of the push rod 24 becomes insufficient, the protrusion 21b of the lever 21 pushes the rotation mechanism 26, so that the gap adjustment unit 25 rotates, and the control 51 and the wheel tread 3a are automatically rotated. The interval between is adjusted.

  A brake head 52 is attached to the end of the push rod 24 on the wheel 3 side via a connecting pin 27. The brake head 52 is a metal whose outer shape is formed by casting or sheet metal in a substantially arc shape, and supports the brake wheel 51 on the end surface on the wheel 3 side. Further, the upper end portion of the restrictor suspension 53 is rotatably attached to the first casing portion 30 via the connecting pin 28, and the push rod 24, the restrictor head 52, and the lower end of the restrictor suspension 53. The connecting portion (connecting pin 27) is supported.

  The push rod 24 is installed so as to protrude from the drive mechanism chamber 31 toward the outside through the opening 30 b formed in the first casing portion 30. A cover member 32 formed in a bellows shape is provided between the push bar 24 and the edge of the opening 30b so as to cover the gap between the opening 30b and the push bar 24. The cover member 32 has a bellows shape and is formed of an elastic material. The cover member 32 can expand and contract as the push bar 24 moves forward and backward, and prevents dust and the like from entering the drive mechanism chamber 31 from the opening 30b. It is also possible to suppress intrusion of outside air.

  Further, the push rod 24 is formed with a long hole 24b at the tip of the portion bent in an L shape on the side of the restrictor, and a pin 54 fixed to the restrictor head 52 corresponds to the inclination of the restrictor head 52. And the inclination of the brake head 52 is regulated by contacting the inner wall of the long hole 24b. Thereby, the excessive inclination of the brake head 52 can be prevented when the brake is released.

  The restrictor 51 is a brake friction material that is pressed against the wheel tread 3a to generate a braking force. The control member 51 is a cast iron control member made of general cast iron, an alloy cast iron control member made of cast iron containing a certain amount or more of phosphorus or manganese, a synthetic control member mainly composed of synthetic resin, and a metal powder base material. Thus, a sintered alloy control wheel that is sintered by adding a powder component having predetermined control characteristics. The restrictor 51 is a plate-like member whose outer shape is a substantially arc shape. The control device 51 is fixed to the control device head 52 by a control device key (control device cotter) (not shown). The brake device 51 moves forward toward the wheel 3 when braking and is pressed against the wheel tread 3a. And away from the wheel tread 3a.

  The second casing part 40 is a cylindrical container whose periphery is covered so as to form a predetermined space inside. The second casing part 40 protrudes toward the outside on the bottom part 41, and is inside the second casing part 40. There is an attachment portion 42 in which a communication hole 43 penetrating from the outside toward the outside is formed. The attachment portion 42 is threaded with a male screw that is screwed into a female thread on the taper that is threaded into the opening 30 c of the first casing portion 30. The second casing part 40 is attached to the first casing part 30 by screwing the attachment part 42 into the opening 30c in an airtight manner. Further, a vent hole 44 penetrating from the inside of the second casing portion 40 toward the outside is formed on the wall surface of the second casing portion 40 near the end portion away from the communication hole 43. The vent hole 44 is formed so as to incline in the direction of gravity (downward) from the inside toward the outside, and is formed so that sand, dust, and the like are less likely to enter from the outside.

  And in the 2nd casing part 40, the division member 45 is installed so that the communicating hole 43 side and the vent hole 44 side may be divided. The partition member 45 is a cylindrical member having an outer diameter smaller than the inner diameter of the second casing portion 40 formed of an elastic body such as rubber, and has a side surface formed in a bellows shape. It can be extended and contracted. Further, one end in the cylindrical axis direction is closed by a partition screen 46, and the other end is opened. Then, the opening-side end portion is hermetically attached to the bottom surface portion 41 with an adhesive or the like (not shown) so as to surround the periphery of the opening of the communication hole 43. That is, it is attached so as to prevent gas from passing from the communication hole 43 to the vent hole 44 side. As a result, a variable volume chamber 47 is formed which communicates with the drive mechanism chamber 31 and whose volume is variable by the expansion and contraction of the bellows-like side surface. The volume of the variable volume chamber 47 changes depending on whether the side bellows is extended or contracted. The amount of change in the volume of the rod chamber 16 decreases when the piston 12 moves due to braking. It is formed to have an amount corresponding to the volume.

  The device internal space 100 composed of the rod chamber 16, the drive mechanism chamber 31, and the variable volume chamber 47 described above is formed as a sealed space that can withstand a predetermined change in internal pressure. Then, as will be described later, when the volume of the variable volume chamber 47 changes during the braking operation, the change in the atmospheric pressure (change in the internal pressure) in the apparatus internal space 100 is suppressed to a change that can ensure hermeticity. Making it possible.

Next, the operation of the brake device 5 will be described. FIG. 2 shows the brake device in a brake operating state.
When the compressed air is supplied from the supply port 11 a to the pressure chamber 15 of the cylinder 11 during the braking operation, the piston 12 moves in the A1 direction against the urging force of the urging spring 14, and the piston rod 13 together with the piston 12. Moves in the A1 direction. Then, the lever 21 rotates in the B1 direction with the fulcrum pin 23 as the rotation center. Then, the push rod 24 connected to the end of the lever 21 moves so as to approach the wheel tread surface 3a. As a result, the restrictor 51 and the restrictor head 52 are urged by the push rod 24 to move closer to the wheel tread surface 3a, and the restrictor 51 is pressed against the wheel tread surface 3a to brake the rotation of the wheel 3.

  As shown in FIG. 2, when the brake is operated, the piston 12 moves in the A1 direction, whereby the volume of the rod chamber 16 is reduced. Therefore, the air in the rod chamber 16 is pushed into the drive mechanism chamber 31 communicating with the rod chamber 16, and the pressure in the drive mechanism chamber 31 shifts so as to increase. In the initial state before braking, since the internal pressure of the drive mechanism chamber 31 is substantially equal to the external air pressure, the internal pressure of the drive mechanism chamber 31 rises above the external air pressure. Then, in the second casing portion 40, the air pressure of the variable volume chamber 47 communicating with the drive mechanism chamber 31 also rises, and the partition screen 46 of the partition member 45 that forms the variable volume chamber 47 displays the air in the variable volume chamber 47. 2 is biased toward the outside (in the direction of the arrow in FIG. 2) against the outside air pressure, and deforms so that the bellows-like side surface extends. Thereby, since the volume of the variable volume chamber 47 increases, it is suppressed that the atmospheric | air pressure of the variable volume chamber 47 and the drive mechanism chamber 31 increases excessively. Further, since the periphery of the partition member 45 is covered with the second casing portion 40, the partition member 45 is protected and accommodated in a space outside the variable volume chamber 47 in the second casing portion 40. When the variable volume chamber 47 expands, the air that is being discharged is discharged from the vent hole 44, so that the expansion of the variable volume chamber 47 is not hindered.

  When the brake is released, when the compressed air in the pressure chamber 15 of the cylinder 11 is discharged, the piston 12 moves in the A2 direction by the biasing force of the biasing spring 14, and the lever 21 rotates in the B2 direction with the fulcrum pin 23 as the rotation center. At the same time, the push rod 24 moves away from the wheel 3, and as the push rod 24 moves, the control member 51 moves away from the wheel tread surface 3 a and the braking of the rotation of the wheel 3 is released.

  When the brake is released, the volume of the rod chamber 16 increases as the piston 12 moves in the A2 direction from the state of the brake device shown in FIG. Therefore, air is drawn into the rod chamber 16 from the drive mechanism chamber 31 communicating with the rod chamber 16, and the pressure in the drive mechanism chamber 31 shifts so as to decrease. As a result, the air pressure in the variable volume chamber 47 communicating with the drive mechanism chamber 31 in the second casing portion 40 is also reduced, and the air pressure in the variable volume chamber 47 received by the section screen 46 forming the variable volume chamber 47 is attached. Deforms so that the power is weakened and the bellows-shaped side surface is shrunk. Thereby, since the volume of the volume variable chamber 47 decreases, it is suppressed that the atmospheric | air pressure of the volume variable chamber 47 and the drive mechanism chamber 31 reduces too much. Then, after the brake is released, the pressure in the drive mechanism chamber 31 is maintained substantially equal to the pressure of the outside air.

As described above, the brake device 1 according to the first embodiment includes the cylinder 11, the piston 12 that slides along the inner wall of the cylinder 11, and the piston rod 13 that moves with the piston 12. The drive mechanism 20 is operated using the cylinder device 10 to brake the rotation of the wheels 3.
Then, a rod chamber 16 located on the piston rod 13 side in the cylinder 11, and a drive mechanism that communicates with the rod chamber 16 and that houses the drive mechanism portion 20 driven via the piston rod 13. A chamber 31 and a volume variable chamber 47 which is communicated with the drive mechanism chamber 31 and has a variable volume. The volume variable chamber 47 is arranged in a direction in which the volume of the rod chamber 16 decreases. The volume is configured to change so that the volume increases when the piston 12 is displaced, and the volume decreases when the piston 12 is displaced in the direction in which the volume of the rod chamber 16 increases.

  According to this configuration, when the brake operation is performed, the volume of the variable volume chamber 47 decreases when the volume in the rod chamber 16 increases due to the sliding of the piston 12 of the cylinder device 10. The volume change of the device internal space 100 formed by the chamber 16, the drive mechanism chamber 31, and the variable volume chamber 47 is reduced. Further, when the volume in the rod chamber 16 is changed so as to decrease, the volume of the volume variable chamber 47 is decreased, so that the change in the volume of the device internal space 100 is reduced. Thus, since the volume variable chamber 47 changes the volume so as to keep the volume of the device internal space 100 substantially constant, it is possible to suppress the change in the atmospheric pressure of the device internal space 100. Thereby, it can suppress that external air penetrate | invades into apparatus internal space 100, and it can prevent that dew condensation arises in apparatus internal space 100 by the penetration | invasion of external air.

  In addition, the volume of the volume variable chamber 47 is changed by the action of the atmospheric pressure inside the volume variable chamber 47 and the external pressure received by the volume variable chamber 47.

  According to this configuration, since the volume of the device internal space 100 is changed by the driving of the piston 12 and the pressure is changed can be used for the volume changing operation of the volume variable chamber 47, the volume can be changed with the sliding movement of the piston 12. The configuration for changing the volume of the chamber 47 can be simplified as compared with, for example, a case where a separate driving force is required.

  Further, the volume variable chamber 47 is configured to be capable of changing the volume by the same amount as the volume of the rod chamber that can be changed by sliding of the piston 12.

  According to this configuration, the volume variable chamber 47 can change in volume as much as the volume change of the rod chamber 16, so that the volume of the device internal space 100 can be kept constant even when the stroke of the piston 12 is large. It becomes possible to do. Thereby, it can suppress more reliably that external air penetrate | invades into the said apparatus internal space 100. FIG.

  The variable volume chamber 47 is formed by a partition member 45 having a bellows structure on a side surface.

  According to this configuration, it is possible to ensure the sealing performance of the variable volume chamber 47 with a simple structure and to improve the durability.

  The variable volume chamber 47 is provided above the drive mechanism chamber 31. As described above, since the variable volume chamber 47 is positioned above the brake device 1, a space in the horizontal direction for mounting the brake device 1 on the vehicle can be reduced. Further, since it is difficult to receive an impact from the road surface side (downward) during traveling, it is difficult to break down and the frequency of maintenance can be reduced. In addition, in the structure of this embodiment, since the circumference | surroundings of the division member 45 are covered with the 2nd casing part 40, it can suppress that the division member 45 is damaged, and also it is hard to break down and can reduce maintenance frequency. .

  The drive mechanism unit 20 includes a lever 21 that is fixed to a first casing portion 30 forming the drive mechanism chamber 31 through a fulcrum pin 23 so as to be swingable. One end of the lever 21 is connected to the piston. The other end is connected to a rod 13 and the other end is connected to a push rod 24 for moving the control member 51 forward and backward, and the cylinder device 10 is driven to swing the lever 21 via the piston rod 13. The push rod 24 is moved back and forth to exert a braking force.

  According to this configuration, a braking operation can be performed by the action of the lever, and a large braking force can be applied with a small force. In general, when the brake operation is performed using the lever action, the displacement amount on the force point side (piston rod 13 side) is larger than the displacement amount on the action point side (the push rod 24, the control wheel 51 side). The volume change of the device internal space 100 is likely to occur, and intrusion of outside air into the device internal space 100 tends to be a problem. In this regard, by providing the variable volume chamber 47, the brake operation can be performed while suppressing the volume change of the apparatus internal space 100, and the intrusion of outside air into the apparatus internal space 100 can be suppressed. It is the structure which can utilize the chamber 47 more effectively.

  FIG. 3 shows a modified example of the configuration inside the second casing portion 40. In this modified example, a return spring 60 (elastic body) between the section screen 46 of the partition member 45 and the ceiling surface 48 of the second casing portion 40 and the inner peripheral wall of the second casing portion 40 that is biased by the return spring 60. A plate 61 that can move along is arranged. The section screen 46 of the partition member 45 forming the variable volume chamber 47 is urged by the return spring 60 through the plate 61 in the direction of decreasing the volume of the variable volume chamber 47.

  By configuring in this way, the variable volume chamber 47 can easily shift so that the volume decreases. For this reason, when the piston moves in the A2 direction and the volume of the variable volume chamber 47 decreases, the atmospheric pressure in the apparatus internal space 100 can be kept higher, and the atmospheric pressure in the apparatus internal space 100 can be made higher than the external atmospheric pressure. It can be kept high. Thereby, it is possible to further suppress the outside air from entering the device internal space 100. By energizing the section screen 46 via the plate 61, the section screen 46 can be urged on a plane orthogonal to the moving direction, that is, a plane substantially parallel to the section screen 46, so that stable urging is possible. Is possible.

(Second Embodiment)
Next, a brake device 2 according to a second embodiment of the present invention will be described. FIG. 4 is a diagram illustrating the brake device 2 according to the second embodiment. The brake device 2 is different from the brake device 1 according to the first embodiment in that the variable volume chamber 47 is located inside the first casing portion 30. The same members as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In the brake device 2, a partition plate 71 formed in a plate shape is installed in an upper part of the casing unit 70 that covers the drive mechanism unit 20, and the casing unit 70 is partitioned into an upper space 70 a and a lower space 70 b. Yes. The partition plate 71 is disposed so as to face a surface substantially parallel to the moving direction of the piston rod 13, and is disposed so as to form a substantially horizontal plane in the present embodiment. An opening 71a is formed in the partition plate 71, and the partition plate 71 and the casing can be moved only between the upper space 70a and the lower space 70b through the opening 71a. The unit 70 is hermetically coupled using an O-ring or the like.

  A partition member 45 similar to that of the first embodiment is provided on the upper surface of the partition plate 71 located on the upper space 70a side. In the upper space 70a, the partition member 45 extends and contracts in the vertical direction in FIG. 4 to change the volume of the volume variable chamber 47 formed between the partition screen 46 and the upper surface of the partition plate 71. Is possible.

The upper space 70a is partitioned into the variable volume chamber 47 and other spaces by the partition member 45, and the casing portion 70 is formed with a vent hole 72 that communicates the other spaces with the outside. The vent hole 72 is formed so as to incline in the direction of gravity (downward) from the inside toward the outside, and is formed so that sand, dust, and the like are less likely to enter from the outside.
Since the operation at the time of brake operation is the same as that of the first embodiment, the description is omitted.

  As described above, since the variable volume chamber 47 is installed in the casing portion 70 that covers the drive mechanism portion 20, it is not necessary to separately attach a casing for forming the variable volume chamber 47, and the brake device 2 is formed. The number of parts for doing so can be reduced. Moreover, since the space in the casing part 70 which covers the drive mechanism part 20 can be utilized effectively, the brake device 2 can be reduced in size.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

  In the present embodiment, the configuration in which the partition member 45 is deformed and the volume of the variable volume chamber is changed by the action of the pressure of the air in the apparatus internal space 100 is shown. For example, as shown in FIG. 5, the piston rod 13 is further extended to the drive mechanism chamber 31 side, the end of the extended piston rod 13 ′, and a bellows-like partition member similar to that described in the first embodiment It is also possible to connect the 80 section screens 81 so that the volume of the variable volume chamber 82 can be increased or decreased in conjunction with the reciprocating movement of the piston rod 13.

  Further, when the cylinder mechanism driven by reciprocating movement of the piston rod of the cylinder device 10 is installed symmetrically with the cylinder device 10 and the volume of the rod chamber of the cylinder device 10 is reduced, the rod chamber of the cylinder mechanism installed symmetrically is reduced. When the volume increases, and conversely, when the volume of the rod chamber of the cylinder device 10 increases, the volume of the rod chamber of the cylinder mechanism installed symmetrically can also be reduced.

  1 to 5 used in the description of the present embodiment schematically show the brake device, but the ratio between each component of the brake device is substantially the same as the ratio of the configuration in the actual brake device. It is drawn to be equivalent.

It is a cross-sectional schematic diagram which shows the brake device which concerns on 1st Embodiment of this invention. In the brake device shown in FIG. 1, it is a cross-sectional schematic diagram which shows the state at the time of a brake action. It is a figure which shows the modification of the structure inside the 2nd casing part shown in FIG. It is a cross-sectional schematic diagram which shows the brake device which concerns on 2nd Embodiment of this invention. It is a cross-sectional schematic diagram which shows the brake device which concerns on other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Brake apparatus 10 Cylinder apparatus 11 Cylinder 12 Piston 13 Piston rod 16 Rod chamber 20 Drive mechanism part 21 Lever 24 Push rod 51 Control wheel 30 First casing part 31 Drive mechanism room 40 Second casing part 45 Partition member 47 Volume variable chamber 60 Return spring (elastic body)

Claims (8)

In a brake device that operates a drive mechanism unit and brakes rotation of a wheel using a cylinder device including a cylinder, a piston that slides along the inner wall of the cylinder, and a piston rod that moves with the piston,
A rod chamber located on the piston rod side in the cylinder;
A drive mechanism chamber communicating with the rod chamber and containing the drive mechanism portion driven via the piston rod;
A variable volume chamber that communicates with the drive mechanism chamber and that has a variable volume.
A wall covering the periphery of a member forming the variable volume chamber;
With
The variable volume chamber increases in volume when the piston is displaced in a direction in which the volume of the rod chamber decreases, and decreases in volume when the piston is displaced in a direction in which the volume of the rod chamber increases. The volume changes ,
Wherein the wall, a brake device according to claim Rukoto formed vent to tilt in the direction of gravity toward the outside from the inside of the wall is formed.   2. The brake device according to claim 1, wherein the volume of the variable volume chamber changes due to an action of an atmospheric pressure inside the variable volume chamber and a force received from outside by the variable volume chamber.   3. The brake device according to claim 2, wherein the volume of the variable volume chamber can be changed more than a volume of the rod chamber that can be changed by sliding of the piston.   The brake device according to claim 3, wherein the variable volume chamber is formed using a member having a bellows structure on a side surface.   5. The brake device according to claim 1, wherein the variable volume chamber is provided above the drive mechanism chamber. 6.   6. The brake device according to claim 1, wherein the variable volume chamber is installed in a casing forming the drive mechanism chamber. 6.   7. The brake device according to claim 1, wherein the member forming the variable volume chamber is biased by an elastic body in a direction in which the volume is reduced. The drive mechanism unit includes a lever that is swingably fixed to a casing forming the drive mechanism chamber via a spindle.
One end of the lever is connected to the piston rod, and the other end is connected to a push rod for moving the restrictor forward and backward.
The brake device according to claim 1, wherein the cylinder device is driven to swing the lever through the piston rod, thereby causing the push rod to move forward and backward to exert a braking force.

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