JP2013053654A - Caliper brake system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the vibration of a piston caused by vibration from the outside.SOLUTION: A caliper brake system 100 which is configured to impart a frictional force by clamping a disk 6 rotating together with a wheel 5 includes: a caliper body 10 supported to a vehicle body; brake blocks 7 that advance and retreat with respect to the caliper body 10 and are brought into slide-contact with the disk 6 in order to impart a frictional force; and a diaphragm actuator 50 that presses the brake blocks 7 against the disk 6 by the pressure of compressed air. The diaphragm actuator 50 includes: a cylinder 51 fixed to the caliper body 10; a piston 52 that has a recess 52c concavely formed on a rear surface 52b and advances and retreats with respect to the cylinder 51 in order to press the brake blocks 7; and a diaphragm 53 that is brought into contact with the rear surface 52b of the piston 52 to be along the recess 52c, defines a pressure chamber 55 in the cylinder 51, and is elastically deformed by the pressure in the pressure chamber 55 in order to move the piston 52.

Description

  The present invention relates to a caliper brake device that applies frictional force to a disk that rotates with a wheel to brake the rotation of the wheel.

  2. Description of the Related Art Conventionally, a fluid pressure brake device that performs braking by using fluid pressure such as hydraulic pressure or air pressure is used for a vehicle such as a railway vehicle.

  Patent Document 1 discloses a caliper brake device in which a piston that advances and retreats due to deformation of an elastic film accompanying a change in fluid pressure presses a control member against a disc. In this caliper brake device, the piston is supported by an elastic film, and has a recess formed on a contact surface with the brake device.

JP 2011-47427 A

  However, in the caliper brake device described in Patent Document 1, since the concave portion is formed on the contact surface of the piston with the brake member, the center of gravity of the piston is located away from the brake member. For this reason, when vibration is applied from the outside, there is a possibility that the piston will vibrate due to the moment centering on the contact surface between the restrictor and the disk.

  The present invention has been made in view of the above-described problems, and an object thereof is to suppress piston vibration caused by external vibration.

  The present invention relates to a caliper brake device that applies a frictional force across a disk that rotates together with a wheel. The caliper main body is supported by a vehicle body, and moves forward and backward with respect to the caliper main body. And a pressing mechanism that presses the control against the disk by the pressure of the working fluid, and the pressing mechanism is formed in a concave shape on the back surface, and a cylinder fixed to the caliper body. A piston capable of advancing and retreating with respect to the cylinder to press the brake, and contacting a back surface of the piston along the recess and defining a pressure chamber in the cylinder, And an elastic film that moves the piston by being elastically deformed by the pressure in the pressure chamber.

  In the present invention, the concave portion is formed on the back surface of the piston that presses the brake member. Thereby, the position of the center of gravity of the piston becomes a position closer to the control wheel as compared with the conventional piston. The moment acting on the piston is small because the distance between the contact surface between the control wheel and the piston and the position of the center of gravity is short. Accordingly, it is possible to suppress piston vibration caused by external vibration.

It is a top view of the caliper brake device concerning an embodiment of the invention. It is a front view in FIG. It is AA sectional drawing in FIG. (A) is sectional drawing which shows the gravity center position of a piston, (b) is sectional drawing of the elastic membrane before assembling with a piston. (A) is a front view of the piston which concerns on the modification of embodiment of this invention, (b) is BB sectional drawing in Fig.5 (a).

  Hereinafter, a caliper brake device 100 according to an embodiment of the present invention will be described with reference to the drawings.

  First, the overall configuration of the caliper brake device 100 will be described with reference to FIGS. 1 and 2.

  The caliper brake device 100 is a pneumatic brake for railway vehicles that uses compressed air as a working fluid. The caliper brake device 100 includes a caliper body 10 that is supported by a cart (vehicle body) (not shown) via a support frame 20 and a pair of brakes that can move forward and backward with respect to the caliper body 10 and slidably contact the disk 6 to apply a frictional force. A ring 7, a diaphragm actuator 50 as a pressing mechanism that presses the brake 7 against the disk 6 by the pressure of compressed air, and a pair of adjusters 40 that support the brake 7 on the caliper body 10 are provided.

  The caliper brake device 100 applies a frictional force across the disk 6 that rotates together with the wheels 5. Specifically, the caliper brake device 100 sandwiches the disk 6 from both sides thereof by a pair of restrictors 7, and brakes the rotation of the wheel 5 by the frictional force between the disk 6 and the restrictor 7.

  The disk 6 is formed on both front and back surfaces of the wheel 5 and rotates integrally with the wheel 5. Instead of the structure in which the disk 6 is formed integrally with the wheel 5, a separate disk 6 that rotates together with the wheel 5 may be provided.

  The caliper body 10 includes a first caliper arm 12 and a second caliper arm 14 that extend so as to straddle the disk 6, a yoke portion 13 that connects the first caliper arm 12 and the second caliper arm 14, and the caliper body 10. And a pair of bracket portions 15 for supporting the upper portion.

  The caliper body 10 is floating supported by the upper slide pin 30 and the lower slide pin 32 so as to be slidable with respect to the support frame 20. As a result, the caliper body 10 follows the relative movement of the wheel 5 in the axial direction with respect to the carriage, and the control 7 faces the disk 6 of the wheel 5 in parallel.

  The upper slide pin 30 and the lower slide pin 32 are provided through the support frame 20. Both end portions of the upper slide pin 30 and the lower slide pin 32 are respectively connected to the bracket portion 15 of the caliper body 10. The caliper body 10 is supported by the support frame 20 so that the upper slide pin 30 and the lower slide pin 32 can be relatively moved in the axial direction. The exposed portions of the upper slide pin 30 and the lower slide pin 32 are covered with a rubber boot 34 and protected from dust and the like.

  The restrictor 7 receives a pressing force from the diaphragm actuator 50 and is pressed in parallel with the disk 6 to come into contact therewith. The restrictor 7 has a lining 9 that abuts against a disk 6 that rotates with the wheel 5. The rear surface of the control device opposite to the surface on which the lining 9 is provided is pressed by the diaphragm actuator 50. The brake member 7 brakes the rotation of the wheel 5 by the frictional force generated by the contact between the lining 9 and the disk 6. The upper and lower ends of the restrictor 7 are fixed to anchor pins 43 of an adjuster 40 described later.

  Next, the internal structure of the caliper body 10 will be described with reference to FIGS. 3 and 4.

  As shown in FIG. 3, the diaphragm actuator 50 includes a cylinder 51 fixed to the caliper body 10, a piston 52 that can move forward and backward with respect to the cylinder 51 and press the brake 7 against the disk 6, and compressed air is supplied during braking. A diaphragm 53 as an elastic film that defines the pressure chamber 55 to be supplied in the cylinder 51 and a fixing mechanism 57 that fixes the diaphragm 53 to the piston 52 are provided.

  The diaphragm actuator 50 deforms the diaphragm 53 by adjusting the air pressure in the pressure chamber 55, and moves the piston 52 forward and backward with respect to the cylinder 51 by the deformation of the diaphragm 53. The diaphragm actuator 50 presses the brake 7 against the disk 6 by retracting the piston 52 from the cylinder 51.

  The cylinder 51 has a caliper cover that defines a pressure chamber 55 by closing the back surface of the cylinder body 51a and fixing the diaphragm 53 between the cylinder body 51a and the cylinder body 51a on the inner periphery of the cylinder body 51a. 54.

  The cylinder body 51a is formed in an elliptical cylindrical shape that surrounds the piston 52 in an annular shape. A dust seal 51b that slides on the outer peripheral surface of the piston 52 and protects it from dust or the like is provided on the inner periphery of the cylinder body 51a.

  The caliper cover 54 is an oval plate material corresponding to the cylinder body 51a. The caliper cover 54 is fixed to the end surface of the cylinder body 51a by a plurality of bolts 54a.

  The pressure chamber 55 is defined inside the cylinder 51 by a diaphragm 53 and a caliper cover 54. The pressure chamber 55 advances and retracts the piston 52 as its volume expands and contracts. The pressure chamber 55 is provided with a through hole 56 (see FIG. 2). Compressed air for deforming the diaphragm 53 during braking is supplied from an external air pressure source through the through hole 56.

  The piston 52 is provided in the cylinder 51 in contact with the back surface of the brake 7. The piston 52 has an abutment surface 52a that abuts against the control member 7 and a back surface 52b that is the opposite surface of the abutment surface 52a. The piston 52 advances and retreats in the cylinder 51 due to the deformation of the diaphragm 53 that contacts the back surface 52b.

  The abutting surface 52a is an elliptical plane that presses against the brake 7. The contact surface 52a is formed in an elliptical shape that is slightly smaller than the inner periphery of the cylinder body 51a.

  The back surface 52b is a surface with which the diaphragm 53 abuts. The back surface 52b has a concave portion 52c formed in a concave shape, and a standing portion 52d provided in a ring shape on the outer periphery of the concave portion 52c.

  The concave portion 52c is hollowed out from the back surface 52b toward the inside of the piston 52 and is formed in a concave shape. The recess 52c is formed so that its bottom surface is an ellipse that is slightly smaller than the contact surface 52a.

  As shown in FIG. 4A, the concave portion 52c is formed on the back surface 52b of the piston 52, so that the center of gravity of the piston 52 is compared with the conventional piston having the concave portion formed on the contact surface. The position is close to 7. For this reason, the moment acting on the piston 52 is reduced by the amount that the distance between the contact surface 52a and the center of gravity position is reduced. Therefore, the vibration of the piston 52 caused by external vibration can be suppressed.

  The standing portion 52d is erected from the back surface 52b in parallel with the forward / backward direction of the piston 52. In the standing portion 52d, two corner portions 52e on the inner peripheral side and the outer peripheral side that come into contact with the diaphragm 53 are formed in a curved surface shape. This prevents the diaphragm 53 from being damaged when coming into contact with the diaphragm 53.

  As shown in FIG. 3, the diaphragm 53 abuts against the back surface 52 b of the piston 52 along the recess 52 c of the piston 52. The diaphragm 53 is an elastic material made of resin, and is formed with a bellows using, for example, a composite of reinforcing materials such as carbon fibers and Kepler fibers. Further, it may be a bellows made of a rubber tube or a thin metal plate.

  The diaphragm 53 is elastically deformed by the pressure in the pressure chamber 55 and moves the piston 52. The diaphragm 53 includes a peripheral portion 53a that forms the outermost periphery, a pressing portion 53c that is formed on the innermost periphery, and a bellows portion 53b that is continuously formed between the peripheral portion 53a and the pressing portion 53c.

  The peripheral edge 53a is sandwiched and fixed between the cylinder body 51a and the caliper cover 54. At this time, since the peripheral portion 53a plays a role of packing, the airtightness of the pressure chamber 55 is ensured.

  The bellows portion 53 b is located between the inner peripheral surface of the cylinder body 51 a and the outer peripheral surface of the piston 52. The bellows portion 53b extends from the folded state (the state shown in FIG. 3) when the pressure in the pressure chamber 55 increases, and returns to the folded state when the pressure in the pressure chamber 55 decreases. That is, the bellows portion 53 b can be deformed into a folded state and an extended state by the air pressure supplied to the pressure chamber 55.

  The pressing portion 53c is in contact with the piston 52, and is displaced in the retracting direction of the piston 52 by the extension of the folded bellows portion 53b. As the pressing portion 53 c is displaced, the piston 52 is pressed and moves in the cylinder 51. The pressing portion 53c is formed with a stepped portion 53d corresponding to the corner portion 52e on the inner peripheral side of the standing portion 52d.

  As shown in FIG. 4B, before the diaphragm 53 is assembled with the piston 52, the stepped portion 53d between the pressing portion 53c and the bellows portion 53b is formed in a two-stage cup shape. ing. From this state, first, the pressing portion 53c is inserted into the concave portion 52c of the piston 52 and brought into contact with the bottom surface. Next, the diaphragm 53 is placed along the inner peripheral surface of the recess 52c so that the stepped portion 53d contacts the inner peripheral corner 52e of the standing portion 52d of the piston 52. Then, the bellows portion 53b is folded back to the outer periphery of the standing portion 52d so that the curved surface between the pressing portion 53c and the bellows portion 53b contacts the corner portion 52e on the outer peripheral side of the standing portion 52d.

  Accordingly, the diaphragm 53 comes into contact with the piston 52 across the inner peripheral surface of the recess 52c and the outer peripheral surface of the standing portion 52d. In this manner, the pressing portion 53c and the bellows portion 53b sandwich the standing portion 52d of the piston 52 from both the inner peripheral surface and the outer peripheral surface. Thereby, the outer periphery of the standing portion 52d of the piston 52 is elastically supported by the diaphragm 53 from the entire circumferential direction. Therefore, the movement of the piston 52 in the radial direction is restricted by the elasticity of the diaphragm 53. Therefore, the vibration of the piston 52 due to the vibration from the outside can be further suppressed.

  As shown in FIG. 3, the fixing mechanism 57 fixes the diaphragm 53 to the recess 52 c of the piston 52. The fixing mechanism 57 includes a fixing plate 57a that is fitted in the recess 52c with the diaphragm 53 interposed therebetween, and a bolt 57d as a fixing member that fixes the fixing plate 57a to the recess 52c.

  The fixed plate 57a is a cup-shaped plate material formed in a shape corresponding to the recess 52c. The fixed plate 57a has a flat bottom surface portion 57b and a standing portion 57c that is erected from the bottom surface portion 57b along the recess 52c.

  The bolt 57d passes through the fixed plate 57a and the diaphragm 53 and is fastened to the piston 52. A plurality of bolts 57d are provided, the bottom surface portion 57b is fastened to the bottom surface of the recess 52c, and the standing portion 57c is fastened to the inner peripheral surface of the recess 52c. Thereby, it can prevent that the contact surface of the diaphragm 53 and piston 52 slips, and a contact state changes.

  The bolt 57d is fastened in the recess 52c in the piston 52. Therefore, the bolt 57d does not protrude from the recess 52c toward the caliper cover 54. Thereby, compared with the case where the recessed part 52c is not formed in the back surface 52b of the piston 52, the caliper main body 10 can be reduced in size.

  The adjusters 40 are arranged above and below the diaphragm actuator 50, respectively. The adjusters 40 are fastened to the upper and lower ends of the caliper body 10 by anchor bolts 42, respectively. The adjuster 40 includes a restrainer receiver 41 fixed to the caliper body 10 by an anchor bolt 42 and an anchor pin 43 provided so as to be able to advance and retreat relative to the restrainer receiver 41 and supporting the restrainer 7 to the caliper body 10.

  The anchor pin 43 is formed in a substantially cylindrical shape. The anchor pin 43 has a flange portion 43b formed to project annularly on the outer periphery. The anchor pin 43 moves integrally with the control wheel 7 when the flange portion 43 b is engaged with the control wheel 7. The anchor pin 43 is pulled out in the axial direction by the movement of the restrictor 7 when the diaphragm 53 is deformed during braking and presses the restrictor 7 against the disk 6.

  The anchor pin 43 holds the control member 7 against the disc 6 trying to move the control member 7 in the circumferential direction by frictional force during braking when the control member 7 is in sliding contact with the disc 6. A sliding portion that is exposed to the outside from the restrictor receiver 41 when sliding on the anchor pin 43 is covered with a rubber boot 47 and protected from dust and the like.

  According to the above embodiment, the following effects are obtained.

  By forming the recess 52c in the back surface 52b of the piston 52 that presses the brake member 7, the position of the center of gravity of the piston 52 becomes closer to the brake member 7 than the conventional piston. For this reason, the moment acting on the piston 52 is reduced by the amount that the distance between the contact surface between the control member 7 and the piston 52 and the position of the center of gravity is reduced. Therefore, the vibration of the piston 52 caused by external vibration can be suppressed.

  Next, with reference to FIG. 5, a piston 152 according to a modification of the embodiment of the present invention will be described. Below, the same code | symbol is attached | subjected to the structure similar to embodiment mentioned above, and the overlapping description is abbreviate | omitted suitably.

  The piston 152 is provided on the outer periphery of the contact surface 52a that comes into contact with the brake member 7, the back surface 52b that is the opposite surface of the contact surface 52a, the recess 52c that is formed in a concave shape on the back surface 52b, and the recess 52c on the back surface 52b. And a standing portion 52d that is erected in a ring shape. Further, the piston 152 has a through hole 152f and a through hole 152g formed so as to penetrate from the contact surface 52a to the back surface 52b.

  A pair of through holes 152f are formed at intervals in the longitudinal direction of the piston 152, and a through hole 152g is formed between the pair of through holes 152f. A counterbore is formed at the end of the through hole 152f that opens into the recess 52c. A pin (not shown) for fixing the piston 152 to the restrictor 7 is inserted into the through hole 152f.

  A male screw to be fastened to a female screw (not shown) formed on the brake 7 is formed at the tip of the pin. At the base end of the pin, a collar portion formed in a shape corresponding to the counterbore of the through hole 152f is formed. The flange portion is formed to be flush with the bottom surface of the recess 52c when the pin is inserted into the through hole 152f.

  Here, the piston 152 is not in contact with the inner periphery of the cylinder 51, and is elastically supported in the cylinder 51 via the diaphragm 53. Therefore, the piston 152 tries to move downward by deforming the diaphragm 53 by gravity.

  However, the piston 152 is fixed to the restrictor 7 by the pin inserted into the through hole 152f being fastened to the female screw of the restrictor 7. Therefore, it is possible to prevent the piston 152 from moving downward due to gravity.

  Instead of forming a female screw on the restrictor 7, a hole or a recess into which the tip of the pin is inserted may be formed. In this case, a male screw is not formed at the tip of the pin. When the piston 52 and the diaphragm 53 are assembled, the flange portion is pressed against the piston 52 by the diaphragm 53 contacting the bottom surface of the recess 52c. Therefore, even if the pin is merely inserted into the hole of the control wheel 7, the pin will not come off. At this time, since there is no step between the pin flange and the bottom surface of the recess 52c, the diaphragm 53 is in a contact state equivalent to the case where the through hole 152f is not formed.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  For example, in the above embodiment, the diaphragm actuator 50 is provided only on the first caliper arm 12 side. However, the diaphragm actuator 50 may be a counter piston type in which the diaphragm actuator 50 is provided on both the first caliper arm 12 and the second caliper arm 14 instead of the floating type in which the diaphragm actuator 50 is provided only on one side.

  The present invention can be used as a brake device for a vehicle such as a railway vehicle.

DESCRIPTION OF SYMBOLS 100 Caliper brake device 5 Wheel 6 Disc 7 Strainer 9 Lining 10 Caliper main body 40 Adjuster 50 Diaphragm actuator (pressing mechanism)
51 Cylinder 52 Piston 52a Contact surface 52b Back surface 52c Concave portion 52d Standing portion 52e Corner portion 53 Diaphragm (elastic film)
55 Pressure chamber 57 Fixing mechanism 57a Fixing plate 57d Bolt (fixing member)

Claims (5)

A caliper brake device that applies frictional force across a disk that rotates with a wheel,
A caliper body supported by the vehicle body;
A brake member capable of advancing and retreating with respect to the caliper main body and slidingly contacting the disc to impart a frictional force;
A pressing mechanism that presses the control against the disk by the pressure of a working fluid,
The pressing mechanism is
A cylinder fixed to the caliper body,
A piston having a recessed portion formed in a concave shape on the back, and capable of moving forward and backward with respect to the cylinder to press the brake;
An elastic membrane that contacts the back surface of the piston along the concave portion, defines a pressure chamber in the cylinder, and elastically deforms by the pressure in the pressure chamber to move the piston. Caliper brake device. The piston has a standing portion that is erected in an annular shape on the outer periphery of the concave portion on the back surface,
The caliper brake device according to claim 1, wherein the elastic film abuts on the piston across an inner peripheral surface of the recess and an outer peripheral surface of the standing portion.   3. The caliper brake device according to claim 2, wherein the standing portion is formed with a curved corner at an abutting portion with the elastic film. The elastic membrane is
A pressing portion that contacts the concave portion of the piston;
A bellows portion formed on the outer periphery of the pressing portion and folded back on the outer periphery of the standing portion;
A step portion formed between the pressing portion and the bellows portion and abutting against a corner portion of the standing portion,
The caliper brake device according to claim 2 or 3, wherein the stepped portion is formed in a two-stage cup shape that forms a step in a state before being assembled with the piston. A fixing mechanism for fixing the elastic film to the recess;
The fixing mechanism is
A fixed plate formed in a shape corresponding to the recess, and fitted into the recess across the elastic membrane;
The caliper brake device according to any one of claims 1 to 4, further comprising a fixing member that fixes the fixing plate to the recess.

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