JP2013117236A - Piston operation device and braking system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piston operation device and a braking system capable of smoothing operation while suppressing cost.SOLUTION: A piston operation device has a piston 11 operated in a shaft P direction by the pressure of air, a screw rod 13 attached to the piston 11 via a male screw part 13a whose center is a shaft P and coupled to the piston 11, and a piston rod 14 fitted into the screw rod 13, the male screw part 13a is at least partially discontinuous in a peripheral direction, the screw rod 13 and the piston rod 14 are supported at a position spaced apart from the male screw part 13a by a distance L in the shaft P direction via guide part 39 having predetermined gap G in a radial direction of the shaft P, the size of the gap is smaller than the value geometrically calculated by the dimensional tolerance of the male screw part 13a and the distance L.

Description

  The present invention relates to a piston operating device having a screw feed mechanism.

  Railway vehicles are provided with a tread brake having a parking brake function used during mooring. The piston operating device for operating the tread brake applies air to the brake cylinder and exhausts air from the brake cylinder to apply or release the braking force to the traveling wheels.

  Further, in addition to the normal operation mechanism as described above, such a piston device is provided with a screw feed mechanism for manually releasing the brake force without using working air at the time of failure or maintenance. Yes.

  Such a screw feed mechanism employs a configuration that uses a trapezoidal screw to reduce the operating force. However, simply using a trapezoidal screw causes the screw feed mechanism not to operate smoothly but to apply a large operating force. Sometimes it was necessary.

  Here, Patent Document 1 discloses a screw feed mechanism in a brake cylinder. In this screw feed mechanism, a screw rod is provided on a sleeve rotatably mounted on a piston, and the screw rod is rotated relative to the sleeve to expand and contract, thereby applying a brake force and releasing the brake force. doing. A centering bushing having a lubrication function is provided between the piston and the sleeve, so that the axial centers of the sleeve, the piston and the screw rod are aligned with each other. Instead, the screw feed mechanism operates smoothly.

Japanese Utility Model Publication 2-65727

However, Patent Document 1 does not aim at a smooth operation of the screw portion in the screw feed mechanism, and a specific mechanism for smoothly operating the screw feed mechanism is still desired.
Furthermore, a method of smoothly operating the screw part by increasing the lead angle of the screw part or increasing the number of threads is also conceivable, but in this case, there is a problem that it is difficult to increase the cost of the screw part or to manufacture it. there were.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a piston operating device and a brake device capable of achieving smooth operation of the piston operating mechanism while suppressing cost.

In order to solve the above problems, the present invention employs the following means.
That is, the piston operating device according to the present invention is connected to the piston by being attached to the piston operated in the axial direction by fluid pressure, and a screw portion centered on the shaft or a shaft parallel thereto. And a screw rod that is at least partially discontinuous in the circumferential direction.

  According to such a piston operating device, the sliding resistance of the screw portion can be reduced by discontinuous, ie, removal of a part of the screw portion. Further, by removing a part of the screw part, the weight of the screw part is reduced and the moment of inertia is reduced.

  The piston rod is supported via a guide portion having a predetermined gap in the radial direction of the shaft at a position separated from the screw portion by a distance L in the axial direction. It may be smaller than the value calculated geometrically by the dimensional tolerance of the part and the distance L.

  With such a guide portion, it is possible to prevent the piston rod from being tilted and decentered due to the dimensional tolerance caused by the manufacturing accuracy of the screw portion, and the rotational resistance of the screw portion from increasing. Therefore, the movement of the piston rod can be made smooth by smoothing the operation of the screw portion.

  Further, the gap may be smaller as the distance L is larger.

  As the distance L increases, the dimensional tolerance of the screw part has a greater influence, that is, even if the inclination angle is the same, the piston rod is greatly decentered at the position of the guide part. By reducing the gap, it is possible to prevent this eccentricity, and it is possible to smooth the movement of the piston rod by smoothing the operation of the screw portion.

  The brake device according to the present invention is characterized in that the piston operating device is connected to a braking member that brakes the wheel by contacting a wheel or a member that rotates integrally with the wheel.

  According to such a brake device, the sliding resistance of the screw portion can be reduced only by making the screw portion partially discontinuous. Further, by removing a part of the screw part, the weight of the screw part is reduced and the moment of inertia is reduced. For this reason, it is possible to release the braking force against the wheel by the braking member while suppressing the cost and smoothing the operation of the piston operating device.

  According to the piston operating device and the brake device of the present invention, the sliding resistance of the screw portion can be reduced only by making the screw portion partially discontinuous, and the reduction of the moment of inertia can be achieved. It is possible to facilitate the operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall schematic cross-sectional view showing a brake release state in a normal state of a brake device according to a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall schematic cross-sectional view showing a brake operation state in a normal state of a brake device according to a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a whole schematic sectional drawing which shows the brake release state at the time of manual operation of the brake device which concerns on 1st embodiment of this invention, Comprising: (b) shows the AA cross section of (a). It is a whole schematic sectional drawing which shows the brake relieving state at the time of manual operation of the brake device which concerns on 2nd embodiment of this invention.

Hereinafter, a brake device 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.
The brake device 1 is, for example, a tread brake device having a parking brake function used when mooring a railway vehicle. The tread brake device presses a member against the tread 10a of the wheel 10 to apply a braking force.

  The brake device 1 has a piston operating device 2 that has a substantially cylindrical shape and extends in the axis P direction, and one end 4a connected to the end of the piston device on the one side P1 in the axis P direction (left side in FIG. 1), A link device 4 extending in a height direction perpendicular to the axis P direction, a braking member 3 connected to the other end 4b of the link device 4 via a support, a piston operating device 2 and a link device 4 A casing 5 that covers and holds the inside of the casing 5 and a support piston 6 that supports the link device 4 on the casing 5 are provided.

  The piston operating device 2 includes a cylindrical piston 11 centered on an axis P, a nut 12 fitted on a concentric shaft on the radially inner side of the piston 11 on one side P1 in the axis P direction, and a nut 12 A screw rod 13 having a cylindrical shape that is screwed onto the concentric shaft radially inward and extending in the axis P direction, and is fitted on the concentric shaft radially inward of the screw rod 13 and extends in the axis P direction. And a piston rod 14 having a rod shape.

  The piston 11 has a cylindrical shape centered on the axis P, and is formed with a flange portion 11a that protrudes radially outward at an end portion on the other side P2 in the axis P direction.

  The nut 12 is fitted on the concentric shaft on the radially inner side of the piston 11 on one side P1 in the axis P direction, and the piston 11 and the nut 12 are connected so as not to rotate relative to each other. A female screw portion 12a (screw portion) is formed on the radially inner side of the nut 12.

The screw rod 13 is a cylindrical member that is disposed on the radially inner side of the nut 12 and extends in the direction of the axis P. A male screw portion (screw portion) 13 a is formed on the outer peripheral surface of the screw rod 13. Are fixed to the nut 12 so as to be rotatable relative to the nut 12.
Further, a head portion 13c protruding in the radial direction is formed at the end portion on the other side P2 of the screw rod 13 in the axis P direction.

Next, the male thread portion 13a in the screw rod 13 will be described.
As shown in FIG. 3B, the male screw portion 13a has a plurality of cutout portions 13b (three in the present embodiment) in which the screw threads are cut from the radially outer side to the inner side at equal intervals in the circumferential direction. ) And the entire region in the direction of the axis P.

  Here, at normal times, the male screw portion 13a and the female screw portion 12a of the nut 12 are connected in a state where the relative rotation is restricted by a fixing pin (not shown), and the piston operating device 2 as a whole. Are integrally operated in the direction of the axis P.

  Furthermore, at the time of manual operation, a fixing pin (not shown) is released, and relative rotation is possible between the male screw portion 13a and the female screw portion 12a.

  Further, due to the dimensional tolerance between the male screw portion 13a and the female screw portion 12a, consideration is given to giving some degree of freedom to the movement of the shaft P in the radial direction.

  That is, this degree of freedom is affected by the dimensional tolerance, and an inclination angle θ in the radial direction of the axis P is generated, so that the inclination angle θ and the distance L from the male screw portion 13a to the head portion 13c of the screw rod 13 are obtained. The amount of deflection of the head portion 13c in the radial direction of the axis P calculated geometrically from FIG. That is, as a result of the backlash caused by the dimensional tolerance, the head portion 13c at the tip is shaken in the radial direction by an amount geometrically calculated by L × tan θ.

  The piston rod 14 is a rod-shaped member that is fitted on the concentric shaft P on the radially inner side of the screw rod 13 and extends in the axis P direction. A hole 14a is formed so as to project from one side to the other side P1 in the axis P direction and penetrate in the depth direction perpendicular to the axis P direction and the height direction.

  The link device 4 has a rod-shaped first link 15 and a second link 16 that extend in the height direction and are connected to each other at an intermediate position between the one end 4a and the other end 4b. Yes.

  The first link 15 is a member that extends in the height direction and has a rod shape, and is positioned on the one end 4 a side of the link device 4, and in the depth direction in the hole portion 14 a in the piston rod 14 at the one end 4 a. It is connected so as to be rotatable by a pin 17 extending in the direction. Further, a rotation center pin 18 extending in the depth direction is provided through the middle position in the extending direction. The rotation center pin 18 is fixed to the casing 5.

  The second link 16 extends in the height direction like the first link 15 and is a rod-shaped member. The second link 16 is located on the other end 4b side of the link device 4, and the other end 4b has a braking member. 3 is rotatably connected by a pin 19 extending in the depth direction. Furthermore, a rotation center pin 20 extending in the depth direction is provided in a midway position in the extending direction. The rotation center pin 20 is fixed to the casing 5.

  The first link 15 and the second link 16 are connected to each other by a connecting pin 25 extending in the depth direction at a connecting portion 25 located between the rotation center pins 18 and 20. Yes.

  The casing 5 is a member that covers the piston operating device 2 and the link device 4 from the outside, and a piston housing portion 31 that houses the piston 11 and a screw that projects from the piston housing portion 31 toward the other side P2 in the axis P direction. It has the rod accommodating part 32 and the link apparatus accommodating part 33 in which the link apparatus 4 is accommodated.

  The piston accommodating portion 31 forms a cylindrical space S1 centered on the axis P inside, and is provided on the other side P2 in the direction of the axis P. A hole 36 having a smaller diameter than the inner peripheral surface 31a of the piston accommodating portion 31 is formed. The first wall portion 34 is formed, and the second wall portion 35 is provided on one side P1 in the direction of the axis P and is similarly formed with a hole 38 having a smaller diameter than the inner peripheral surface 31a.

  The first wall portion 34 is a member having a donut shape provided on the other side P2 in the axis P direction and formed with a hole 36. From the edge 36a of the hole 36, one side P1 in the axis P direction is provided. A cylindrical projecting portion 37 projecting toward the inner surface 31a is formed, and the flange portion 11a of the piston 11 is sandwiched between the outer peripheral surface 37a of the projecting portion 37 and the inner peripheral surface 31a of the piston housing portion 31, The piston 11 is held so as to be movable in the direction of the axis P.

  Further, the surface of the flange 11a of the piston 11 facing the other side P2 in the axis P direction, the surface of the first wall 34 facing the one side P1 of the axis P direction, the inner peripheral surface 31a of the piston housing part 31, Air (fluid) F from an air supply source (not shown) flows into and out of the space S2 surrounded by the outer peripheral surface 37a of the protruding portion 37.

  The second wall portion 35 is a donut-shaped member provided on one side P1 in the axis P direction and formed with a hole portion 38. The piston rod 14 can be moved in the axis P direction in the hole portion 38. The end of the piston rod 14 is inserted and held.

  The screw rod accommodating portion 32 protrudes from the first wall portion 34 of the piston accommodating portion 31 to the other side P2 in the axis P direction, and at the edge 36a of the hole portion 36 in the first wall portion 34, that is, inside the protruding portion 37. A cylindrical space S3 centered on the axis P is formed inside so as to be continuous with the peripheral surface 37b, and this cylindrical space S3 has a predetermined gap G so that the screw rod 13 can move in the direction of the axis P. Thus, a guide portion 39 that supports the head portion 13c of the screw rod 13 is formed.

  The gap G in the guide portion 39 has a size that can prevent the eccentricity of the screw rod 13, that is, a diameter generated in the head portion 13c of the screw rod 13 due to a dimensional tolerance between the male screw portion 13a and the female screw portion 12a. The dimension is set smaller than the amount of deflection in the direction.

  The link device accommodating portion 33 holds the link device 4 inside, and the rotation center pins 18 and 20 in the first link 15 and the second link 16 are fixed as described above.

  Further, at the position where the connecting pin 26 is provided in the link device 4, a cylindrical space S4 is formed such that the inner wall surface protrudes to the other side P2 in the axis P direction, and the support piston 6 is provided in the cylindrical space S4. Can be accommodated.

  The support piston 6 is held in the cylindrical space S4 in the link device accommodating portion 33 so as to be movable in the direction of the axis P, and the head portion 45 facing the inner peripheral surface of the cylindrical space S4 and the head portion 45 are connected to each other. It has a support member 46 in the form of a rod that supports and is coupled to the connecting pin 26 in the link device 4 on one side P1 in the axis P direction. In this way, the link device 4 is supported on the casing 5.

  The braking member 3 is connected to the other end 4 b of the link device 4, that is, the end of the second link 16 by a pin 19, and is a connecting member having a rod shape that penetrates the link device housing portion 33 in the casing 5 in the axis P direction. 41 and a control member 43 made of a sliding member made of a material such as cast iron or resin that is connected to the connecting member 41 via the holding portion 42. And this control element 43 can be contact | abutted with respect to the tread 10a of the wheel 10 arrange | positioned at the other side P2 of the axis P direction.

Next, the state of operation of the brake device 1 at the normal time will be described.
As shown in FIG. 1, air F is introduced from an air supply source (not shown) into a space S <b> 2 surrounded by the flange portion 11 a of the piston 11, the first wall portion 34, the piston accommodating portion 31, and the protruding portion 37. The Then, the pressure of the air F causes the piston 11 to be pressed to one side P1 in the axis P direction, the head portion 13c of the screw rod 13 moves through the guide portion 39, and the piston rod 14 is pushed out to one side P1 in the axis P direction. It is.

  At this time, since the male screw portion 13a and the female screw portion 12a are fixed by a fixing pin (not shown) in a screwed state and do not relatively rotate between the screw rod 13 and the nut 12, the shaft P There is no relative movement in the direction. That is, the piston operating device 2 is integrally moved to one side P1 in the axis P direction.

  Thus, when the piston rod 14 is pushed out to the one side P1 in the axis P direction, the end portion of the first link 15 which is the one end 4a of the link device 4 is one side in the axis P direction around the rotation center pin 18. Move toward P1. Along with this, the connecting portion 25 is supported by the support piston 6 and is pushed into the other side P2 in the axis P direction while being supported by the link device accommodating portion 33 in the casing 5.

  Further, when the connecting portion 25 is pushed into the other side P2 in the axis P direction in this way, the other end 4b of the link device 4, that is, the end portion of the second link 16 is moved in the axis P direction around the rotation center pin 20. Move toward one side P1.

  Then, when the connecting member 41 in the braking member 3 connected to the other end 4b of the link device 4 is pulled to the one side P1 in the axis P direction, the control member 43 is separated from the tread surface 10a of the wheel 10, and the brake is released. It becomes a state.

  Conversely, as shown in FIG. 2, when the air F flows out of the space S <b> 2 surrounded by the flange portion 11 a of the piston 11, the first wall portion 34, the piston accommodating portion 31, and the protruding portion 37, the piston 11 is Pushed back to the other side P2 in the axis P direction, the head portion 13c of the screw rod 13 moves through the guide portion 39, and the piston rod 14 is pushed back to the other side P2 in the axis P direction.

  At this time, the male screw portion 13a and the female screw portion 12a are fixed by a fixing pin (not shown) in a screwed state and do not move relative to the axis P direction. Moves integrally to the other side P2 in the axis P direction.

  When the piston rod 14 is pushed back to the other side P2 in the axis P direction in this way, the end portion of the first link 15 which is the one end 4a of the link device 4 is moved to the other side in the axis P direction around the rotation center pin 18. Move toward P2. Accordingly, the connecting portion 25 is pushed out to one side P1 in the axis P direction while being supported by the support piston 6 and supported by the link device housing portion 33 in the casing 5.

  Further, when the connecting portion 25 is pushed out to the one side P1 in the axis P direction in this way, the other end 4b of the link device 4, that is, the end portion of the second link 16 is moved in the axis P direction around the rotation center pin 20. Move toward the other side P2.

  Then, when the connecting member 41 in the braking member 3 connected to the other end 4b of the link device 4 is pressed to the other side P2 in the axis P direction, the brake member 43 is pressed against the tread surface 10a of the wheel 10, and the braking action state It becomes.

Next, the operation state of the brake device 1 during manual operation will be described.
As shown in FIG. 3A, the fixing pin (not shown) is released at the time of manual operation, so that relative rotation is possible between the male screw portion 13a and the female screw portion 12a. Then, by rotating the screw rod 13 relative to the nut 12, the head portion 13 c of the screw rod 13 moves through the guide portion 39, and only the screw rod 13 and the piston rod 14 are integrated to one side in the axis P direction. Move to side P1. At this time, air F does not flow from the air supply source, and the piston 11 is maintained in the same position as the brake release state in the normal state.

  When the piston rod 14 is pushed out to the one side P1 in the direction of the axis P in this way, the link device 4 and the support piston 6 operate in the same manner as in the normal brake release state as described above. When the connecting member 41 of the braking member 3 connected to the end 4b is pulled to the one side P1 in the axis P direction, the control member 43 is separated from the tread surface 10a of the wheel 10 and the brake is released.

  In such a brake device 1, during manual operation, the male screw portion 13 a of the screw rod 13 and the female screw portion 12 a of the nut 12 are relatively rotated, so that the screw rod 13 and the piston rod 14 are moved in the direction of the axis P. Can be moved. At this time, a cutout portion 13b is formed in the male screw portion 13a, and the sliding resistance with the female screw portion 12a is reduced by the cutout portion 13b.

  Moreover, the weight of the external thread part 13a, ie, the screw rod 13, is reduced by the notch part 13b. (Note: The effect of moment of inertia is negligible at low speed)

  Furthermore, between the male threaded portion 13a of the screw rod 13 and the female threaded portion 12a of the nut 12, due to dimensional tolerances, the head portion 13c, the guide portion 39, and the run-out dimension of the head portion 13c of the screw rod 13 are generated. The gap G is set small. Accordingly, the screw rod 13 is supported by the head portion 13c at the tip, and the sliding resistance between the male screw portion 13a and the female screw portion 12a can be reduced.

  In the brake device 1 of the present embodiment, a notch 13b is formed in the male screw portion 13a so as to be partially discontinuous in the circumferential direction, and the guide portion 39 prevents the screw rod 13 and the piston rod 14 from being eccentric. Only by setting G, the movement of the screw rod 13 and the piston rod 14 can be made smooth during manual operation. Moreover, since it becomes possible to operate with a small force, it becomes possible to release the brake force by separating the control member 43 from the tread surface 10a of the wheel 10 while reducing the cost.

  In addition, the quantity of the notch part 13b is not limited to the case of this embodiment. Furthermore, the notched range may be a wider range in the circumferential direction than in the present embodiment.

Next, the brake device 50 according to the second embodiment will be described.
In addition, the same code | symbol is attached | subjected to the component similar to 1st embodiment, and detailed description is abbreviate | omitted.
The brake device 50 of the present embodiment is different from the first embodiment in the male threaded portion 53a of the screw rod 53.

  As shown in FIG. 4, the male screw portion 53 a is formed only on the end portion on one side P <b> 1 in the axis P direction and the end portion on the other side P <b> 2 on the outer peripheral surface 53 b of the screw rod 53. That is, it is formed discontinuously in the direction of the axis P.

  In such a brake device 50, when the screw rod 53 and the piston rod 14 are moved in the direction of the axis P during manual operation, the male screw portion 53a is formed discontinuously in the direction of the axis P. The sliding resistance with the part 12a can be reduced.

  Further, since the male screw portion 53a is formed discontinuously, the weight of the screw rod 53 is reduced.

  In the brake device 50 of the present embodiment, the male screw portion 53a is partially discontinuous in the axis P direction, and the guide portion 39 prevents eccentricity of the screw rod 53 and the piston rod 14 as in the first embodiment. Only by setting the gap G, the screw rod 53 and the piston rod 14 can be moved smoothly during manual operation, and can be operated with a small force. It is possible to release the braking force by separating from the 10 treads 10a.

  Note that the gap G between the guide rod 39 and the head portion 53c of the screw rod 53 is such that if the distance L from the male screw portion 53a to the head portion 53c increases, the guide rod 39 and the screw rod 53 By further reducing the size of the gap G between the head portion 53c and the head portion 53c, eccentricity of the screw rod 53 and the piston rod 14 can be prevented, and smooth operation can be achieved.

The embodiment of the present invention has been described in detail above, but some design changes can be made without departing from the technical idea of the present invention.
For example, the male screw portion 53a of the second embodiment may be combined with the male screw portion 13a of the first embodiment. In this case, the male screw portion is formed discontinuously in the axis P direction and the circumferential direction. Thus, further smooth operation of the screw rod 53 and the piston rod 14 can be achieved.

  In the above-described embodiment, the male screw portions 13a and 53a are partially discontinuous to facilitate the operation. However, the female screw portion 12a may be partially discontinuous. However, the male screw portions 13a and 53a and the female screw portion 12a may be partially discontinuous.

  Moreover, although the above-mentioned embodiment demonstrated the tread brake device 1 incorporating the piston operating device 2, this piston operating device 2 is applicable also to a drum brake, a disc brake, etc.

DESCRIPTION OF SYMBOLS 1 ... Brake apparatus 2 ... Piston operation apparatus 3 ... Braking member 4 ... Link apparatus 4a ... One end 4b ... Other end 5 ... Casing 6 ... Support piston 10 ... Wheel 10a ... Tread 11 ... Piston 11a ... Flange part 12 ... Nut 12a ... Female Screw part (screw part) 13 ... Screw rod 13a ... Male screw part (screw part) 13b ... Notch part 13c ... Head part 14 ... Piston rod 14a ... Hole part 15 ... First link 16 ... Second link 17 ... Pin 18 ... Rotation center pin 19 ... Pin 20 ... Rotation center pin 25 ... Connection portion 26 ... Connection pin 31 ... Piston housing portion 31a ... Inner peripheral surface 32 ... Screw rod housing portion 33 ... Link device housing portion 34 ... First wall portion 35 ... First Two walls 36 ... hole 36a ... edge 37 ... projection 37a ... outer peripheral surface 37b ... inner peripheral surface 38 ... hole DESCRIPTION OF SYMBOLS 9 ... Guide part G ... Gap 41 ... Connection member 42 ... Holding part 43 ... Control part 45 ... Head part 46 ... Supporting member P ... Shaft P1 ... One side P2 ... Other side F ... Air S1 ... Cylindrical space S2 ... Space S3 ... Cylindrical space S4 ... Cylindrical space 50 ... Brake device 53 ... Screw rod 53a ... Male thread part 53b ... Outer peripheral surface 53c ... Head part

Claims (4)

A piston operated axially by fluid pressure;
A piston rod attached to the piston via a threaded portion centered on the shaft or a shaft parallel to the shaft, and connected to the piston;
The screw operating device according to claim 1, wherein the screw portion is at least partially discontinuous in a circumferential direction. The piston rod is supported via a guide portion having a predetermined gap in the radial direction of the shaft at a position separated from the screw portion by a distance L in the axial direction.
2. The piston operating device according to claim 1, wherein a size of the gap is smaller than a value geometrically calculated by a dimensional tolerance of the screw portion and the distance L. 3.   The piston operating device according to claim 2, wherein the gap is smaller as the distance L is larger.   A brake device comprising: a piston operating device according to any one of claims 1 to 3 coupled to a wheel or a member that rotates integrally with the wheel to brake the wheel.

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