WO2016009927A1

WO2016009927A1 - Damper

Info

Publication number: WO2016009927A1
Application number: PCT/JP2015/069704
Authority: WO
Inventors: 尚弘堀田; 陽太小堀
Original assignee: オイレス工業株式会社
Priority date: 2014-07-16
Filing date: 2015-07-08
Publication date: 2016-01-21
Also published as: JP6400966B2; JP2016023653A

Abstract

This damper absorbs the axial run-out of a moving member that moves in a reciprocating manner along an axial center while using a load that has hysteresis characteristics to damp the moving member. A push rod (4) that is to be damped by the damper (100) comprises side surfaces (441) to (446) that are inclined with respect to an axial center (O). The damper (100) comprises a bush (2), an elastic body (3), and a cylindrical case (10) for housing the bush (2) and the elastic body (3). The bush (2) comprises a plurality of sliding sections (20) that support the side surfaces (441) to (446) of the push rod (4) by means of a sliding surface (22). The sliding sections (20) elastically deform so as to be displaced in the direction leading away from the axial center (O) of the push rod (4) and in the direction approaching the axial center (O) of the push rod (4). The elastic body (3) is arranged between the inner wall surface (104) of the case (10) and the bush (2) and biases the sliding sections (20) of the bush (2) toward the axial center (O) of the push rod (4) so that the sliding surfaces (22) thereof are pushed against the side surfaces (441) to (446) of the push rod (4).

Description

damper

The present invention relates to a linear motion type friction mechanism having hysteresis characteristics, and more particularly to a damper suitable for braking a linear motion member that inclines while moving linearly, such as a push rod of a brake actuator that assists a driver to depress a pedal.

In Patent Document 1, using a hysteresis characteristic of a damper including a pair of cams, an appropriate load is applied to the depression of the accelerator pedal, and the driver's foot when the accelerator pedal is held at a substantially constant position. An accelerator pedal unit that reduces this burden is described.

In this accelerator pedal unit, the rotation of the accelerator pedal arm is transmitted to the rotating shaft of the damper via a transmission mechanism composed of a link member or the like, whereby the bidirectional rotation of the accelerator pedal arm is braked. Specifically, one end of the link member is fixed to the rotation shaft of the damper so that the rotation shaft of the damper is rotated by the rotation of the link member. On the other hand, an engaging member is fixed to the accelerator pedal arm at the opposite end of the accelerator pedal across the rotation axis of the accelerator pedal arm, and the engaging member is slidably held by the link member. As a result, when the accelerator pedal arm rotates, the rotation shaft of the damper rotates in the direction corresponding to the rotation direction of the accelerator pedal arm via the link member, and due to the hysteresis characteristic of the damper, an appropriate load is applied when the accelerator pedal is depressed. The load is reduced when the accelerator pedal is returned (paragraphs 0071 to 0084, FIGS. 13 to 19 and the like).

JP 2002-12052 A

By the way, in an automobile brake or the like, if an attempt is made to realize a pedal operation feeling that a moderate load is applied to the driver's foot when the pedal is depressed while the load on the driver's foot is reduced while the pedal is held, It is necessary to mount a special brake pedal unit that incorporates a damper similar to that of the accelerator pedal unit of the car. For example, any general-purpose brake pedal arm can be selected as long as it can provide the brake pedal arm with a load having hysteresis characteristics according to the required pedal operation feeling from the push rod side of the brake actuator that assists the driver's pedal depression. By simply connecting to the push rod, the required pedal operation feeling can be stably realized.

However, since the damper incorporated in the conventional accelerator pedal unit brakes the bi-directional rotation of the accelerator pedal arm, it cannot be directly applied to the braking of a linear member such as a push rod of a brake actuator. Have difficulty. In addition, since a shaft runout (vibration in a direction inclined with respect to the axis of the brake cylinder) occurs in the push rod connected to the brake pedal arm by a clevis joint, a damper that brakes such a push rod includes: It is required to stably exhibit the hysteresis characteristics corresponding to the required pedal operation feeling while absorbing the shaft deflection of the push rod.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a damper that brakes a moving member with a load having a hysteresis characteristic while absorbing axial vibration of the moving member that reciprocates along an axis. There is to do.

In order to solve the above-described problems, in the present invention, sliding regions arranged at a plurality of positions surrounding the axis of the moving member are displaced in a direction away from the axis of the moving member and a direction approaching the axis of the moving member. By using the sliding member that is elastically deformed and the elastic body that presses the sliding area of the sliding member against the support surface of the moving member, the sliding area of the sliding member is adjusted to the axis of the moving body. Is pressed against the support surface of the moving member with an elastic force corresponding to the amount of displacement of each sliding region. Here, as the support surface supported by at least one of the sliding regions of the sliding member, a moving member having an inclined surface with respect to the shaft center is used, so that the sliding member moves during the movement of the moving member. The sliding region pressed against the inclined surface of the member is elastically deformed while following the inclined surface.

For example, the damper according to the present invention is
A plurality of sliding regions for supporting the moving member at a plurality of positions surrounding the axis of the moving member so as to reciprocate along the axis of the moving member are formed. One sliding member that is elastically deformed so that the plurality of sliding regions are displaced in a direction away from and a direction approaching the axis of the moving member;
A cylindrical case surrounding the sliding member around the axis of the moving member;
The sliding member is interposed between the inner wall surface of the case and the sliding member, and biases the sliding member toward the axis of the moving member so as to press the plurality of sliding regions against the moving member. And an elastic body.

According to the present invention, the sliding member supports the inclined surface with respect to the axis of the moving body that moves along the axis in the sliding region that is urged toward the axis of the moving body by the elastic body. At the same time, the elastic deformation is performed while following the sliding area on the inclined surface, so that the shaft touch of the moving member can be absorbed and the driving force applied to the moving member in a predetermined direction along the axis of the moving member. Due to the frictional resistance generated between the inclined surface of the moving member and the sliding area of the sliding member against the source, reaction forces of different magnitudes (loads having hysteresis characteristics) are generated in the forward and return strokes of one stroke. Can be given.

FIG. 1 is a view for explaining a state in which a brake pedal arm 60 is attached to a push rod 4 of an electric brake actuator in which a damper 100 according to an embodiment of the present invention is incorporated. FIG. 2 is a part development view of the damper 100 including the push rod 4. 3A is an axial cross-sectional view of the damper 100 that supports the push rod 4 before the brake pedal is depressed, and FIG. 3B is a cross-sectional view taken along the line AA of FIG. 3A. 4A is a front view of the push rod 4, and FIG. 4B and FIG. 4C are a BB sectional view and a CC sectional view of FIG. 4 (D) is a right side view of the push rod 4. 5A is an external view of the bush 2, and FIGS. 5B, 5C, and 5D are a front view, a side view, and a rear view of the bush 2, and FIG. FIG. 5E is a DD cross-sectional view of FIG. 6A is a cross-sectional view of the damper 100 when the brake pedal is depressed, and FIG. 6B is a cross-sectional view taken along line FF in FIG. 6A. 7A is a diagram for explaining the positional relationship between the case 10 and the sliding portion 20 of the bush 2 before the brake pedal is depressed, and FIG. 7B is a diagram illustrating the case 10 when the brake pedal is depressed. It is a figure for demonstrating the positional relationship with the sliding part 20 of the bush. FIG. 8A is an external view of the rubber member 31 used as the elastic body 3, and FIG. 8B is a diagram illustrating an arrangement example of the rubber member 31 in the cylindrical chamber 105 of the housing 1. 9A, 9B, and 9C are a front view, a side view, and a rear view of the bush 2A, and FIG. 9D is a cross-sectional view taken along line GG in FIG. 9A. FIG. 9E is a diagram for explaining another example of the bush 2A.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this embodiment, the damper 100 incorporated in the electric brake actuator that assists the depression of the brake pedal is taken as an example.

FIG. 1 is a schematic view showing a state in which a brake pedal arm 60 is attached to a push rod 4 of an electric brake actuator in which a damper 100 according to the present embodiment is incorporated. FIG. 2 includes the push rod 4. FIG. 3 is a component development view of the damper 100. 3A is an axial cross-sectional view of the damper 100 that supports the push rod 4 before the brake pedal is depressed (initial state), and FIG. 3B is a cross-sectional view taken along line A— in FIG. It is A sectional drawing.

As shown in the figure, the damper 100 according to the present embodiment supports a push rod 4 that transmits a pedal force received by a brake pedal to a piston in a brake cylinder so as to be reciprocally movable along its axis O. The damper 1 is housed in a housing 1 having

rod insertion ports

12 and 13 for inserting the push rod 4 and an interior (cylindrical chamber) 105 of the housing 1, and is arranged radially so as to surround the push rod 4. The bush 2 that is one sliding member that supports the side surfaces 441 to 446 of the push rod 4 with the plurality of sliding portions 20, the inner peripheral surface of the housing 1 (the inner wall surface 104 of the case 10), and the sliding portion of the bush 2 For example, in the radial direction of the housing 1 (the radial direction of the case 10) toward the axis O of the housing 1 (the axis of the push rod 4) O. ) To and includes an elastic body 3 for urging the bush 2, a. The elastic body 3 only needs to be able to urge the bush 2 toward the axis O of the housing 1. However, in the present embodiment, the case where one O-ring 30 is provided as the elastic body 3 is exemplified. ing.

By incorporating the damper 100 having such a structure in the electric brake actuator, the shaft runout (vibration in a direction inclined with respect to the axis O) generated in the push rod 4 connected to the brake pedal arm 60 by the clevis joint 61 is prevented. While absorbing, the push rod 4 moving along the axis O can be braked with a load having a hysteresis characteristic corresponding to the required pedal operation feeling by depressing the brake pedal. Hereinafter, the push rod 4 and the components 1 to 3 of the damper 100 that support the push rod 4 will be described in detail.

First, the push rod 4 to be braked will be described.

4A is a front view of the push rod 4, and FIG. 4B and FIG. 4C are a BB sectional view and a CC sectional view of FIG. 4 (D) is a right side view of the push rod 4.

As shown in the figure, the push rod 4 slides along the axis O in order from one end face 41 side with a piston drive unit 43 that drives a piston in a brake cylinder of the electric brake actuator, and a bush 2 of the damper 100. A tapered shaft portion 44 having side surfaces 441 to 446 that can be supported and a pedal arm connecting portion 45 to which the brake pedal arm 60 is connected are formed.

The piston drive unit 43 protrudes from the rod insertion port 12 of the housing 1 to the outside of the housing 1 (outside of the cylindrical chamber 105) toward the piston rear end face in the brake cylinder. When the push rod 4 moves (advances) toward the brake cylinder by depressing the brake pedal, the front end surface (one end surface of the push rod 4) 41 of the piston driving unit 43 is abutted against the rear end surface of the piston and the brake cylinder. The piston moves forward. In addition, this piston drive part 43 should just have arbitrary shapes (for example, cylindrical shape) suitable for butting to the piston rear-end surface in a brake cylinder.

The tapered shaft portion 44 is inserted into the inside of the housing 1 (cylindrical chamber 105) through the

rod insertion ports

12 and 13 of the housing 1, and a partial section having a predetermined length is sequentially formed from the axis O side to the bush 2. The O-ring 30 is surrounded by the inner peripheral surface of the housing 1 (the inner wall surface 104 of the case 10). The tapered shaft portion 44 has a so-called frustum shape that is longer in the direction of the axis O than the maximum stroke of the push rod 4. In the present embodiment, as an example, the push rod 4 having a truncated pyramid-shaped tapered shaft portion 44 having a hexagonal cross-sectional shape is used. In such a truncated cone-shaped tapered shaft portion 44, the side surfaces 441 to 446 are inclined with respect to the axis O so that the distance D from the axis O decreases as the piston drive unit 43 is approached. is doing. As will be described later, in the cylindrical chamber 105 of the housing 1, each sliding portion 20 of the bush 2 is pressed against the side surfaces 441 to 446 one by one by the elastic force of the O-ring 30. Is reciprocally moved along the axis O, while slidingly contacting these side surfaces 441 to 446, the direction away from the axis O of the push rod 4 and the direction approaching the axis O of the push rod 4 (for example, the case 20) Reciprocate in the radial direction).

The pedal arm connecting portion 45 protrudes from the rod insertion port 13 of the housing 1 toward the opposite side of the piston driving portion 43 to the outside of the housing 1 (outside of the cylindrical chamber 105). The pedal arm connecting portion 45 has, for example, a cylindrical shape, and a clevis joint 61 that rotatably holds the brake pedal arm 60 is fixed to an end surface (the other end surface of the push rod 4) 42. A screw hole 451 is formed. For example, the brake pedal arm 60 is rotatably connected to the push rod 4 by screwing a bolt 63 fixed to the clevis joint 61 with a nut 64 into the screw hole 451 and fastening the bolt 63 and the nut 65. (See FIG. 1). Thus, when the brake pedal arm 60 rotates in both directions around the rotation shaft 62, the push rod 4 reciprocates along the axis O in conjunction with the brake pedal arm 60.

Next, details of the components 1 to 3 of the damper 100 will be described.

The housing 1 includes a case 10 that accommodates the bush 2 and the O-ring 30 concentrically, and a cover 11 that closes the opening 103 of the case 10 (see FIG. 2).

The case 10 has a bottomed cylindrical shape shorter than the length L in the axial center O direction of the tapered shaft portion 44 of the push rod 4 so as to surround a part of the tapered shaft portion 44 of the push rod 4. A screw portion 106 is formed on the inner periphery of the opening 103. On the other hand, the cover 11 has a disk shape, and a screw portion 111 fastened to a screw portion 106 formed on the inner periphery of the opening 103 of the case 10 is formed on the outer peripheral surface 110 thereof. By attaching the cover 11 to the opening 103 of the case 10 and fastening the screw portion 111 of the outer peripheral surface 110 of the cover 11 and the screw portion 106 of the opening 103 of the case 10, A chamber (cylindrical chamber) 105 surrounded by the bottom surface 101 of the case 10 and the inner wall surface 104 is formed.

In the central region of the bottom surface 101 of the case 10, the outer diameter of the piston driving portion 43 of the push rod 4 is formed as a through hole that becomes one rod insertion port 12 of the housing 1 at a position where the axis O of the cylindrical chamber 105 passes. A through hole 102 having an inner diameter larger than R1 is formed. Similarly, in the central region of the cover 11, as a through hole that becomes the other rod insertion port 13 of the housing 1 at a position where the axial center O of the cylindrical chamber 105 passes, the outer diameter R 2 of the pedal arm connecting portion 45 is larger. A through hole 112 having a large inner diameter is formed.

5A is an external view of the bush 2, and FIGS. 5B, 5C, and 5D are a front view, a side view, and a rear view of the bush 2, and FIG. FIG. 5E is a DD cross-sectional view of FIG.

The bush 2 is a cylindrical integrally molded product made of, for example, resin that surrounds the tapered shaft portion 44 of the push rod 4, and the tapered shaft portion 44 that supports the push rod 4 so as to reciprocate along the axis O. The same number (six in this embodiment) of sliding portions 20 as the side surfaces 441 to 446 of this embodiment and the adjacent sliding portions 20 in the direction around the axis O of the push rod 4 are connected. And a plurality (six in this embodiment) of connecting portions 21 that are elastically deformed in accordance with the relative movement of the two.

The six sliding portions 20 are arranged at almost equal angles around the axis O of the push rod 4, and the initial positions of the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 (relative to the push rod 4). One is located at one limit position of the movable range of the bush 2, for example, the position of the bush 2 in FIG. On the push rod 4 side of each sliding portion 20, there is a sliding surface 22 inclined at substantially the same angle as the opposing side surfaces 441 to 446 of the tapered shaft portion 44 with respect to the direction of the axis O of the push rod 4. The push rod 4 is formed as a sliding region that slidably supports the push rod 4. These sliding surfaces 22 are in surface contact with the side surfaces 441 to 446 of the opposed tapered shaft portion 44 to support the push rod 4 so as to be capable of reciprocating along the axis O.

Further, each sliding portion 20 has a columnar shape along a circular arc having a smaller radius of curvature than the inner diameter R4 of the inner wall surface 104 of the case 10, for example, as a surface facing the side opposite to the sliding surface 22. A convex surface (outer surface) 23 is provided. When these six sliding portions 20 are arranged in the cylindrical chamber 105 of the housing 1 in a state where they are positioned on the side surfaces 441 to 446 of the tapered shaft portion 44, the outer surface 23 of each sliding portion 20 and the inside of the case 10 are arranged. A gap corresponding to the difference between the inner diameter R4 of the case 10 and the outer diameter of the cylindrical body formed by the six sliding portions 20 is formed between the wall surface 104 and the wall surface 104. As will be described later, the O-ring 30 is accommodated in this gap, and the six sliding portions 20 are pressed so as to press the sliding surfaces 22 of the respective sliding portions 20 against the side surfaces 441 to 446 of the tapered shaft portion 44. When the push rod 4 reciprocates along the axis O direction of the push rod 4, the six sliding portions 20 move the respective sliding surfaces 22 on the side surfaces 441. While being in sliding contact with .about.446, it reciprocates in a direction approaching the axis O of the cylindrical chamber 105 of the housing 1 and a direction away from the axis O of the cylindrical chamber 105 of the housing 1 (for example, the radial direction of the case 10).

On the other hand, each of the six connecting portions 21 is passed between two adjacent sliding portions 20 in the direction around the axis O of the push rod 4, and each of the two adjacent sliding portions 20. They are coupled and elastically deform according to the relative movement of the two sliding portions 20 to which the respective coupling portions 21 are coupled. For example, the six connecting portions 21 are coupled to the two sliding portions 20 that are connected to each other by the two leg portions 24, and are bent in a direction in which the interval between the two sliding portions 20 varies. (For example, an arch shape). By connecting the sliding parts 20 with such connecting parts 21, when each sliding part 20 receives a load, it is displaced in the direction of the load while elastically deforming the connecting part 21 coupled to itself, When the load is unloaded, it quickly returns to the initial position by the restoring force of the connecting portion 21 coupled to itself.

Further, the six connecting portions 21 protrude in a direction away from the axis O of the push rod 4 at the central portion 25 connecting the two leg portions 24, rather than the two sliding portions 20 to be connected to each other. The cylindrical chamber 105 is sandwiched between the O-ring 30 and the back surface 113 of the cover 11. Thereby, relative rotation of the bush 2 with respect to the housing 1 is prevented, and relative movement of the adjacent sliding portions 20 in the direction along the axis O of the push rod 4 is prevented. The push rod 2 can be supported in an appropriate posture. Further, even if the thickness of the sliding portion 20 (the interval between the sliding surface 22 and the outer surface 23) is reduced, the sliding portion 20 is prevented from coming out from the

rod insertion ports

12 and 13 of the housing 1. By reducing the thickness of the sliding portion 20 to such an extent that the corner portion 447 of the tapered shaft portion 44 exposed from between the adjacent sliding portions 20 does not contact the O-ring 30, for example, A space that can accommodate the large O-ring 30 may be secured between the inner wall surface 104 of the case 10 and the outer surface 23 of the sliding portion 20.

The O-ring 30 is disposed in the cylindrical chamber 105 along the inner wall surface 104 of the case 10 in a state where the O-ring 30 is mounted on the outer surface 23 of the sliding portion 20 of the bush 2 around the axis O. The O-ring 30 is larger than the distance between the outer surface 23 of the six sliding portions 20 arranged at the initial positions of the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 and the inner wall surface 104 of the case 10. It has a wire diameter. For this reason, the O-ring 30 is configured such that the six sliding portions 20 are positioned at the initial position with respect to the tapered shaft portion 44 of the push rod 4, and the outer surface 23 of each sliding portion 20 and the case 10. It is preloaded between the inner wall surface 104 and further compressed by the outer surface 23 of each sliding portion 20 and the inner wall surface 104 of the case 10 as the push rod 4 moves forward. As a result, the six sliding portions 20 are biased toward the axis O of the push rod 4 by an elastic force corresponding to the amount of displacement in the direction away from the axis O of the push rod 4.

In the present embodiment, each connecting portion 21 protrudes in a direction away from the axis O of the push rod 4. For example, each connecting portion 21 extends from the six sliding portions 20 to the bottom surface of the case 10. It may be formed along the axis O of the push rod 4 so as to protrude toward the 101, and the central portion 25 of each connecting portion 21 may be brought into contact with the bottom surface 101 of the case 10.

In the present embodiment, the case where all the connecting portions 21 are formed on the one end face 28A side of the bush 2 is illustrated, but it is not always necessary to do so. The two sliding portions 20 adjacent to each other in the direction around the axis O of the push rod 4 can be connected so as to be relatively movable, and the elastic body 3 is attached to the outer surface 23 of the sliding portion 20 of the bush 2. If this is not disturbed, the formation position of each connecting portion 21 is not limited.

For example, the connecting portion 21 may be formed on the other end face 28B side of the bush 2. Further, it is not necessary for all the connecting portions 21 to be arranged in a line in the direction around the axis O of the push rod 4, and instead of the bush 2, as shown in FIGS. 9 (A) to 9 (D), Alternatively, the bush 2A may be used in which the connecting portion 21 is formed on the one end face 28A side and the other connecting portion 21 is formed on the other end face 28B side.

The bush 2A is formed along the axis O alternately from both end faces 28A, 28B of a cylindrical body having an inner wall surface tapered according to the inclination of the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4. The

slits

27A and 28B are formed. The

slits

27A and 28B do not reach the other end faces 28B and 28A, and the cylindrical bodies are alternately connected by arc-shaped curved regions (functioning as the connecting portion 21) on both end faces 28A and 28B. Is divided into a plurality of regions (functioning as the sliding portion 20). Each connecting portion 21 has a wall thickness of the sliding portion 20 so as to smoothly elastically deform from the initial arc shape to, for example, a linear shape, etc., according to the displacement of the two sliding portions 20 connected to itself. Is also formed thin.

According to such a shape, when each sliding part 20 receives a load, the

slits

27A and 28B on both sides of the arc-shaped connecting part 21 connected to the both end faces 28A and 28B of the sliding part 20 respectively. Although it is displaced in the direction of the load while being elastically deformed in a widening and narrowing direction (for example, a direction in which the bending of the connecting portion 21 is further widened, a direction in which the connecting portion 21 is further bent from the initial arc shape), For example, it quickly returns to the initial position by the restoring force of the connecting portion 21 coupled to itself. That is, the bush 2A includes a plurality of sliding portions 20 that slidably support the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 and the sliding portions 20 that are adjacent in the direction around the axis O. And a plurality of connecting portions 21 that are connected and elastically deformed in accordance with the relative movement of the sliding portion 20.

Here, the width of each of the

slits

27A and 28B increases as it moves away from the axis O (as it approaches the outer surface 23 of the sliding portion 20), and the respective connecting portions 21 are further out of the sliding portion 20. It is preferable to couple to the sliding portion 20 at a position close to the side surface 23. In FIG. 9, the side surfaces of the sliding portions 20 (the outer surface 23 and the sliding surface 22 of the sliding portion 20 are set so that the widths of the respective slits 27 A and 28 B are widest on the outer surface 23 of the sliding portion 20. In this example, the slits 27 A and 28 B are cut in parallel, and the connecting portions 21 are connected to the outer surface 23 of the sliding portion 20. In this way, slits are formed along the radial direction of the cylindrical body without changing the size of the bush 2A itself (the side surfaces 29 of the respective sliding portions 20 are along the radial direction of the cylindrical body). The arc-shaped connecting portion 21 can be made longer than the case where the arc-shaped connecting portion 21 is formed on the side close to the axis O. For this reason, since the connection part 21 can be elastically deformed more greatly and the movable range of the sliding part 20 by the elastic deformation of the connection part 21 can be expanded, each sliding part 20 is a tapered shaft part. The sliding surface 22 can be smoothly displaced while following the side surfaces 441 to 446 of 44.

9A to 9D show the case where the arc-shaped connecting portions 21 are formed. For example, as shown in FIG. One or more curved portions convex toward the axis O may be provided. By doing so, the movable range of the sliding portion 20 can be further expanded, so that each sliding portion 20 makes the sliding surface 22 follow the side surfaces 441 to 446 of the tapered shaft portion 44. Further, it can be displaced smoothly.

When such a bush 2A is used, the bottom surface 101 of the case 10 and the back surface 113 of the cover 11 are prevented so that the bush 2A does not come out of the

rod insertion ports

12 and 13 of the housing 1 as the push rod 4 moves. It is preferable to determine the thickness of each sliding portion 20 so that both end faces 28A and 28B of the bush 2A are in contact with each other. Further, a groove (not shown) for fitting an O-ring 30 interposed between the outer surface 23 of each sliding portion 20 and the inner wall surface 104 of the case 10 may be formed.

In the present embodiment, the truncated pyramid-shaped tapered shaft portion 44 having a hexagonal cross-sectional shape is provided on the push rod 4, but the truncated pyramid shape having a polygonal cross-sectional shape other than the hexagonal shape is provided. A tapered shaft portion 44 may be provided on the push rod 4. Alternatively, the push rod 4 may be provided with a tapered shaft portion 44 having a truncated cone shape or a columnar shape having at least one side surface inclined with respect to the direction of the axis O. In this case, a plurality of support positions of the tapered shaft portion 44 may be determined around the axis O of the push rod 4, and the same number of sliding portions 20 as the support positions of the tapered shaft portion 44 may be provided on the bush 2. Of the sliding portions 20 of the bush 2, at least one sliding portion 20 whose support target is a side surface inclined with respect to the axis O is substantially equiangular with the side surface of the support target with respect to the axis O. An inclined sliding surface 22 is preferably formed.

Such a damper 100 is assembled to the push rod 4 by the following procedure, for example, and is assembled to the electric brake actuator.

The push rod 4 is connected to the six sliding portions of the bush 2 so that the sliding surfaces 22 of the sliding portion 20 of the bush 2 come into contact with the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 one by one. It inserts in the area | region enclosed with 20 (henceforth the insertion port 26). At this time, since each connecting portion 21 is elastically deformed so that the interval between the adjacent sliding portions 20 in the direction around the axis O of the push rod 4 is widened, the push rod 4 is smoothly inserted into the insertion port 26 of the bush 2. Can be inserted. Then, the position of the bush 2 with respect to the push rod 4 is adjusted so that each sliding portion 20 is located at, for example, the initial position on the side surfaces 441 to 446 of the tapered shaft portion 44.

Thus, the push rod 4 to which the bush 2 is attached so as to surround the tapered shaft portion 44 is inserted into the O-ring 30, and the O-ring 30 is attached to the outer surface 23 of the six sliding portions 20. The push rod 4 is moved to a position where the bush 2 and the O-ring 30 attached to the bush 2 are accommodated inside the case 10 so that the piston driving portion 43 of the push rod 4 protrudes to the outside of the case 10. The piston drive unit 43 is passed through the through hole 102 in the bottom surface 101 of the case 10 through the inside of the case 10. At this time, a gap narrower than the wire diameter of the O-ring 30 is formed between the inner wall surface 104 of the case 10 and the outer surface 23 of the six sliding portions 20 of the bush 2 along the inner wall surface 104 of the case 10. Therefore, the O-rings 30 attached to the outer surfaces 23 of the six sliding portions 20 so as to surround the axis O of the push rod 4 are connected to the outer surfaces 23 of the respective sliding portions 20 and the inside of the case 10. The wall 104 is slightly compressed (preloaded).

Thereafter, the cover 11 is attached to the opening 103 of the case 10 while the push rod 4 is inserted into the through hole 112 of the cover 11 so that the pedal arm connecting portion 45 of the push rod 4 protrudes toward the surface 114 side of the cover 11. The screw part 111 of the outer peripheral surface 110 of the cover 11 is fastened to the screw part 106 of the opening 103 of the case 10 until the back surface 113 of the cover 11 comes into contact with each connecting part 21 of the bush 2. As a result, the six connecting portions 21 of the bush 2 are sandwiched between the back surface 113 of the cover 11 and the bottom surface 101 of the case 10 (see FIG. 3A), and therefore, along the axis O of the bush 2. Movement in the direction is restricted.

After assembling the damper 100 to the push rod 4 in this way, the damper 100 is mounted on the housing of the electric brake actuator so that the front end surface 41 of the piston drive portion 43 of the push rod 4 abuts against the rear end surface of the piston in the brake cylinder. Fix to etc. Thereby, the damper 100 which supported the push rod 4 so that the reciprocation along the axial center O was supported is integrated in an electric brake actuator. Next, the operation of the damper 100 incorporated in the electric brake actuator will be described.

6A and 6B are diagrams for explaining the state of the damper 100 while the brake pedal is depressed. FIG. 6A is a cross-sectional view of the damper 100 when the brake pedal is depressed, and FIG. It is FF sectional drawing of (A). 7 is a diagram for explaining a change in the state of the O-ring before and after the brake pedal is depressed. FIG. 7A is a sliding portion between the case 10 and the bush 2 before the brake pedal is depressed (initial state). FIG. 7B shows the positional relationship between the case 10 and the sliding portion 20 of the bush 2 when the brake pedal is depressed.

In the initial state of the damper 100, the six sliding portions 20 of the bush 2 of the cylindrical chamber 105 of the housing 1 are each positioned at the initial position and directed toward the axis O of the push rod 4 by the preloaded O-ring 30. For example, it is urged | biased by the radial direction of case 10 (refer FIG. 3 (A) and FIG. 3 (B)).

Here, when the driver depresses the brake pedal and the brake pedal arm 60 rotates in a predetermined direction around the rotation shaft 62, the push rod 4 is interlocked with the brake pedal arm 60 as shown in FIG. The damper 100 moves from the position in the initial state in the direction α toward the brake cylinder (not shown). In the following, movement in the direction α toward the brake cylinder is called forward, and movement in the direction away from the brake cylinder (opposite to the direction α) β is called backward.

At this time, as shown in FIG. 6B, the six sliding portions 20 of the bush 2 urged toward the axis O of the push rod 4 by the O-ring 30 elastically move the six connecting portions 21. While being deformed, the sliding surface 22 is brought into sliding contact on the respective side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 that is moving forward, while moving away from the axis O of the push rod 4 (the inner wall surface of the case 10). (Direction approaching 104). As a result, as shown in FIG. 7B, the gap D1 between the outer surface 23 of the six sliding portions 20 and the inner wall surface 104 of the case 10 gradually decreases, and the O-ring 30 2 is further compressed by the outer side surface 23 of each sliding portion 20 and the inner wall surface 104 of the case 10. For this reason, due to the elastic force of the O-ring 30, the sliding surface 22 of the sliding portion 20 of each bush 2 is more strongly pressed against the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 and is sliding. The frictional force between the two

surfaces

22, 441 to 446 gradually increases. That is, as the push rod 4 moves forward, the frictional force that prevents the push rod 4 from moving forward gradually increases. Since the push rod 4 is braked by the braking force generated by such frictional resistance, an appropriate load corresponding to the depression amount of the brake pedal is given to the foot (drive source) of the driver who depresses the brake pedal.

During this time, even if axial vibration (vibration in a direction inclined with respect to the axis O) occurs in the push rod 4 connected to the brake pedal arm 60 that rotates around the rotation shaft 62 by the clevis joint 61, the push rod 4 The sliding portions 2 of the respective bushes 2 supporting the side surfaces 441 to 446 of the tapered shaft portion 44 are connected to the connecting portion 21 and the O-ring 30 appropriately coupled to the push rod 4 according to the posture of the push rod 4. It moves in the radial direction of the case 10 toward the inner wall surface 104 of the case 10 while being elastically deformed. For this reason, the axial deflection of the push rod 4 can be absorbed by the elastic force of the O-ring 30 and the elastic force of the connecting portion 21 of the bush 2, and the push rod 4 can be guided along its axis O in an appropriate posture. it can.

Here, once the driver stops the depression of the brake pedal, the forward movement of the push rod 4 is stopped, and the sliding portion 20 of each bush 2 and the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 are stopped. In the meantime, a frictional force is generated in a direction that prevents the O-ring 30 from restoring (a direction that prevents the push rod 4 from moving backward). For this reason, the load applied to the foot of the driver holding the brake pedal at a fixed position is rapidly reduced.

When the brake pedal arm 60 is rotated in the reverse direction by the driver loosening the brake pedal, the push rod 4 moves backward (moves in the direction β to return to the initial position). At this time, each sliding portion 20 of the bush 2 is urged by the O-ring 30 compressed between the inner wall surface 104 of the case 10 and each side surface of the tapered shaft portion 44 of the push rod 4 being retracted. While sliding the sliding surface 22 on 441 to 446, it moves in a direction approaching the axis O of the push rod 4 (a direction away from the inner wall surface 104 of the case 10). As a result, as shown in FIG. 7A, the gap D1 between the outer surface 23 of the six sliding portions 20 of the bush 2 and the inner wall surface 104 of the case 10 gradually widens, and the O-ring 30 is in the initial state. Therefore, the frictional force between the sliding surface 22 of each sliding portion 20 and the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 is further gradually reduced. That is, as the push rod 4 moves backward, the frictional force that prevents the push rod 4 from moving backward gradually decreases. Since the push rod 4 that is moving backward is braked by the braking force generated by such frictional resistance, the brake pedal smoothly returns to the initial position in accordance with the movement of the driver's foot.

During this time, as in the case where the brake pedal is depressed, the push rod 4 connected to the brake pedal arm 60 by the clevis joint 61 may cause shaft deflection, but the elastic force of the O-ring 30 and the connection of the bush 2 are likely to occur. Since the axial deflection of the push rod 4 is absorbed by the elastic force of the portion 21, the push rod 4 can be guided along its axis O in an appropriate posture.

As described above, according to the damper 100 according to the present embodiment, the bush 2 has the sliding surface 22 urged toward the axis O of the push rod 4 by the O-ring 30 and the tapered shaft portion 44 has the tapered surface 44. Since the side surfaces (inclined surfaces with respect to the axis O of the push rod 4) 441 to 446 are supported and elastically deformed while the sliding surface 22 follows the side surfaces 441 to 446 of the tapered shaft portion 44, the shaft of the push rod 4 A touch is absorbed by the elastic force of both the O-ring 30 and the bush 2 and is applied to a drive source (driver's foot) that applies a force in a predetermined direction along the axis O of the push rod 4 to the push rod 4. Due to the frictional force between the side surfaces 441 to 446 of the tapered shaft portion 44 and the sliding surface 22 of the bush 2, the size is large in the forward path and the return path of one stroke. It can give different reaction force (load having a hysteresis characteristic).

In addition, the bush 2 restores the initial shape of the sliding portion 20 displaced toward the axis O of the push rod 4 by the restoring force of the connecting portion 21, so that the plurality of sliding portions 20 are placed in an appropriate posture. The side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 can be positioned at appropriate positions.

It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the gist.

For example, in the above embodiment, the damper 100 incorporated in the electric brake actuator of an automobile is taken as an example. However, the damper according to the present invention absorbs the shaft touch of the moving member that reciprocates along the axis. On the other hand, the reciprocating movement of the moving member can be applied to applications where it is useful to brake with a braking force having a hysteresis characteristic. For example, the present invention is not limited to an electric brake actuator of an automobile, and can be incorporated into various devices having a linear motion member connected to an operation unit that receives a user operation, such as a musical instrument, a game machine, and various devices.

In the above embodiment, the push rod 4 that is a member to be braked is provided with side surfaces (inclined surfaces with respect to the moving direction) 441 to 446 with respect to the axis O, and these side surfaces 441 to 446 are used as sliding portions of the bush 2. 20 is directly supported, but when the inclined surface with respect to the moving direction cannot be provided on the member to be braked, etc., the moving member supported so as to be reciprocally movable by the plurality of sliding portions 20 of the bush 2 is used as a braking member. A member having an inclined surface with respect to the moving direction of the target member may be prepared, and the moving target member may hold the braking target member. For example, a cylindrical collar member having an insertion opening into which the push rod is inserted in the axial direction is provided, and an inclined surface with respect to the axial center of the push rod is formed on the collar member. While the sliding surface 22 and the inclined surface of the at least one sliding portion 20 are in sliding contact with each other, the collar member is moved back and forth along the axis of the push rod along with the push rod. You may support by the moving part 20. FIG.

In the above embodiment, one O-ring 30 is used as the elastic body 3 interposed between the outer surface 23 of the sliding portion 20 of the bush 2 and the inner wall surface 104 of the case 10. This is not always necessary.

For example, the O-ring 30 is a belt-like region in the circumferential direction that is narrower than its wire diameter, contacts the outer surface 23 of each sliding portion 20 of the bush 2, and pushes each sliding portion 20 of the bush 2 to the push rod. The rubber member 31 that contacts the entire outer surface 23 of each sliding portion 20 of the bush 2 is used as the elastic body 3 instead of such an O-ring 30. Also good. FIG. 8A shows the appearance of such a rubber member 31, and FIG. 8B shows an arrangement example of the rubber member 31 in the cylindrical chamber 105 of the housing 1.

As shown in the figure, the rubber member 31 includes a cylindrical portion 32 having substantially the same length as the bush 2, and a plurality of rubber members 31 formed on the outer peripheral surface 35 of the cylindrical portion 32 around the axis O of the cylindrical portion 32 at substantially equal angular intervals. Projecting portion 33.

The bush 2 is inserted into the cylindrical portion 32. The inner wall surface 34 of the cylindrical portion 32 has a column shape that follows the shape of the outer surface 23 of each sliding portion 20 of the bush 2 inserted into the cylindrical portion 32. In addition, slits 36 are formed in the cylindrical portion 32 along the axis O from one end surface 37 at a position between adjacent protrusions 33. These slits 36 accommodate the connecting portions 21 of the bush 2 inserted into the cylindrical portion 32, respectively. For this reason, the outer surface 23 of each sliding part 20 of the bush 2 inserted in the cylindrical part 32 contacts the inner peripheral surface 34 of the cylindrical part 32 in almost the entire area. As a result, the entire outer surface 23 of each sliding portion 20 can be uniformly pressed by the rubber member 31.

On the other hand, the plurality of protrusions 33 are positioned along the axis O of the cylindrical portion 32 at a position sandwiched between the outer surface 23 of each sliding portion 20 and the inner wall surface 104 of the case 10. It is formed from an edge portion 37A of the end face 37 to an edge portion 38A of the other end face (not shown). For this reason, these protrusions 33 can contact the inner wall surface 104 of the case 10 along the axis O of the case 10 to generate a frictional force between the case 10 and the rubber member 31.

Here, almost the entire outer surface 23 of each sliding portion 20 of the bush 2 is in contact with the inner peripheral surface 34 of the cylindrical portion 32 of the rubber member 31, but each sliding portion 20 of the bush 2. The outer surface 23 may be in contact with the inner peripheral surface 34 along the axis O of the cylindrical portion 32.

If the sliding portion 20 of the bush 2 can be pressed against the side surfaces 441 to 446 of the bush rod 4 with an elastic force corresponding to the amount of displacement of each sliding portion 20 relative to the inner wall surface 104 of the case 10, the bush 2 A plurality of O-rings 30 may be interposed between the outer surface 23 of the sliding portion 20 and the inner wall surface 104 of the case 10. Depending on the device to be assembled with the damper 100, for example, an O-ring having a smaller wire diameter than the O-ring 30 is arranged side by side with the above-described O-ring 30 preloaded in the initial state of the damper. At the timing when the sliding portion 20 of the bush 2 is displaced by a predetermined displacement amount toward the inner wall, an O-ring having a small wire diameter is added to the outer surface 23 of the sliding portion 20 of the bush 2 in addition to the above-described O-ring 30. And the inner wall surface 104 of the case 10 may be compressed. According to such a configuration, the timing at which the operation unit is operated to a predetermined position (the push rod 4 is displaced by a predetermined amount in the direction of the axis O) while applying an appropriate load to the user's limb or the like that operates the operation unit. At the timing, the load on the user's limbs can be increased rapidly. For this reason, it is possible to give a tactile signal that notifies the user that the operation unit has been operated to a predetermined position.

Further, for example, the tapered shaft portion 44 of the push rod 4 or the above-described collar member may be created by connecting a plurality of tapered members formed of materials having different friction coefficients in the axis O direction. A plurality of sheet-like members formed of materials having different friction coefficients may be arranged so as to be aligned in the axis O direction on the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 or the inclined surface of the collar member. Good. Thereby, on the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 or the inclined surface of the collar member, a plurality of sections having different friction coefficients are continuous in the direction of the axis O, so that the operation portion is operated to a predetermined position. The load on the user's limbs and the like can be rapidly increased at the timing (the timing at which the push rod 4 is displaced by a predetermined amount in the direction of the axis O). Alternatively, by applying a surface treatment to the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 or the inclined surface of the collar member, the side surfaces 441 to 446 of the tapered shaft portion 44 of the push rod 4 or the collar member A plurality of sections having different friction coefficients may be included in the inclined surface continuously in the direction of the axis O.

Further, in place of the O-ring 30, another elastic body that elastically deforms in the radial direction of the case 10, one between the outer surface 23 of each sliding portion 20 of the bush 2 and the inner wall surface 104 of the case 10. (Rubber etc.) may be arranged.

In the above-described embodiment, the brake target member is supported by one bush 2, but the number of bushes corresponding to the space of the cylindrical chamber 105 of the housing 1 is included in the brake target member. You may mount so that it may be located in a line with the axial center O direction. In this case, for example, a stopper that prevents the movement of the bush 2 in the direction of the axis O may be provided on the inner wall surface 104 of the case 10. These bushes 2 may have different friction coefficients from the member to be braked, and each bush 2 has a compression start timing due to the outer surface of the sliding portion of the bush and the inner wall surface 104 of the case 10. Different elastic bodies 3 (O-rings 30 having different wire diameters, rubber members 31 having different radial thicknesses of the cylindrical chamber 105, etc.) may be mounted.

1: Housing, 2, 2A: Bush, 3: Elastic body, 4: Push rod, 10: Case, 11: Cover, 12, 13: Rod insertion port, 20: Sliding part, 21: Connecting part, 22: Sliding Sliding surface of moving part, 23: Outer surface of sliding part, 24: Leg part of connecting part, 25: Central part of connecting part, 30: O-ring, 31: Rubber member, 41, 42: End face of push rod 43: Piston drive part 44: Tapered shaft part 45: Pedal arm connecting part 60: Brake pedal arm 61: Clevis joint 62: Rotating shaft of brake pedal arm 63: Bolt 64, 65: Nut 101: bottom surface of the case, 102: through hole, 103: opening of the case, 104: inner wall surface of the case, 105: cylindrical chamber, 1 6: threaded portion 110: outer peripheral surface of the cover, 111: threaded portion of the cover periphery, 112: through hole, 113: back face of the cover, 114: surface of the cover

Claims

A plurality of sliding regions for supporting the moving member at a plurality of positions surrounding the axis of the moving member so as to reciprocate along the axis of the moving member are formed. One sliding member that is elastically deformed so that the plurality of sliding regions are displaced in a direction away from and a direction approaching the axis of the moving member;
A cylindrical case surrounding the sliding member around the axis of the moving member;
The sliding member is interposed between the inner wall surface of the case and the sliding member, and biases the sliding member toward the axis of the moving member so as to press the plurality of sliding regions against the moving member. An elastic body.
The damper according to claim 1,
A damper comprising the moving member.
The damper according to claim 1 or 2,
The sliding member is
A plurality of sliding portions each formed with the sliding region and moving in a direction away from the axis of the moving member and a direction approaching the axis of the moving member;
Provided between two adjacent sliding parts in the direction around the axis of the moving member, each connecting the two sliding parts, and depending on the relative movement of the two sliding parts And a plurality of connecting portions having elasticity that flexes in a direction in which the interval between the two sliding portions in the direction around the axis of the moving member changes.
The damper according to claim 3, wherein
The moving member has an inclined surface with respect to the axis of the moving member,
Of the sliding regions of the plurality of sliding portions, the sliding region of at least one sliding portion supports the moving member on the inclined surface, and the moving member moves along the axis of the moving member. When sliding, the sliding member is in sliding contact with the inclined surface pressed by the elastic body, depending on the direction of movement of the moving member out of the direction away from the axis of the moving member and the direction of approaching the axis of the moving member. A damper characterized in that it is displaced in a different direction.
The damper according to claim 4, wherein
The damper is characterized in that the sliding region that is in sliding contact with the inclined surface is inclined with respect to the axis of the moving member and is in surface contact with the inclined surface.
The damper according to claim 4 or 5, wherein
For each of the plurality of sliding regions, the moving member becomes narrower as the distance from the axis of the moving member toward the first direction along the axis at a position facing the sliding region. Having the inclined surface;
When the moving member moves in the first direction, each of the plurality of sliding regions is in a direction away from the axis of the moving member while slidingly contacting the inclined surface facing the sliding region. Each of the plurality of connecting portions is elastically bent in a direction in which the interval between the two sliding portions connected by the connecting portions is widened,
When the moving member moves in the second direction opposite to the first direction after moving in the first direction, each of the plurality of sliding regions is opposed to the sliding region. The damper is characterized by being displaced in a direction approaching the axis of the moving member while slidingly contacting an inclined region, and each of the plurality of connecting portions is restored to a shape before deflection.
The damper according to any one of claims 3 to 6,
Each of the plurality of connecting portions is
A damper having two legs coupled to two sliding portions to which the coupling portion is coupled, and having a bifurcated shape that bends in a direction in which the interval between the two sliding portions opens.
The damper according to any one of claims 3 to 7,
A cylindrical rubber member into which the sliding member is inserted along the axis of the moving member is provided as the elastic body,
On the inner peripheral surface of the rubber member,
A region of the sliding portion that faces the surface opposite to the sliding region includes a region that follows the surface on the opposite side, and the sliding portion is connected to the shaft of the moving member in the region. A damper characterized by energizing towards the heart.
The damper according to claim 8, wherein
The rubber member is
A plurality of protrusions projecting toward the inner wall surface of the case at positions sandwiched between the plurality of sliding portions and the case, and contacting the inner wall surface of the case along the axis of the movable body The damper characterized by having.
The damper according to claim 9, wherein
In the moving member,
A damper having an insertion hole for inserting a braking target member that reciprocates along the axis of the moving member along the axis of the moving member.