JPH08239020A - Damper of parking brake pedal - Google Patents

Abstract

PURPOSE: To simply and inexpensively constitute a damper for generating a sufficient damping effect during returning of a pedal and a small reaction force during depressing of the pedal. CONSTITUTION: A piston 12 is fitted into the fitting section 16b of a piston rod 16 so as to be relatively moved by only a specified dimension in an axial direction and when this is moved in the right direction of a figure during returning of a pedal, by sandwiching an O ring 18 between the piston 12 and a nut 20 (flange section 20a), flowing of air through an air passage 28 between the fitting section 16b and the piston 12 is interrupted and when this is moved in the left direction of the figure during depressing of the pedal, a gap is formed between the piston 12 and the O ring 18 and the air passage 28 is communicated to an air chamber 30 side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damper device for a parking brake pedal, and more particularly to a damper device which generates a sufficient damper action when the pedal is returned but has a small reaction force when the pedal is depressed, which is simple and inexpensive. It is about technology.

[0002]

2. Description of the Related Art (a) A piston which is slidably fitted in a cylinder tube to separate the inside of the cylinder tube into two gas chambers; A piston rod protruding from one end to the outside, the piston rod being disposed between the parking brake pedal and the position fixing member, and the piston rod being attached to the cylinder tube in accordance with the rotation of the parking brake pedal. When the parking brake pedal is returned to the original position by being pushed and pulled out relative to the pedal, the movement resistance of the piston is increased and decreased by the increase and decrease of the gas pressure due to the volume change of the two gas chambers. To generate a large damper action, but when the parking brake pedal is depressed To reduce the movement resistance of the piston to increase the flow rate of gas between the two gas chambers, the reaction force of the small gas dampers apparatus is known. Japanese Utility Model Publication No. 61-37064 and Japanese Utility Model Publication No. 62-138670.
The device described in the publication is an example, and in the former, the diameter-expanding member is arranged in the tapered piston portion, and when the pedal is returned, the diameter-expanding member is expanded and the seal member is attached to the inner surface of the cylinder tube. While the gas flow is obstructed by the close contact, the diameter expansion member is reduced in diameter during the stepping operation to allow the gas flow. The latter controls the gas flow using a U-cup seal. It is like this.

[0003]

However, in such a conventional damper device, the piston and the piston rod are integrally configured, and the orifice structure for circulating the gas is complicated, and the diameter expanding member, the U-cup seal, and the like are used. Since expensive parts are used, there is a problem that the device is expensive as a whole. Further, in the structure in which an annular groove is provided on the outer peripheral surface of the piston and the space between the piston and the cylinder tube is sealed by a seal member such as a U-cup seal,
Since there is a burr caused by the parting line (PL) on the inner surface of the annular groove, there is a problem that the seal member is easily damaged by the burr.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a damper device which can generate a sufficient damper action when the pedal is returned but has a small reaction force when the pedal is depressed. It consists in cheap construction. Another object is to prevent burrs from being formed on the inner surface of the annular groove in which the seal member is mounted due to the parting line.

[0005]

[First Means for Solving the Problems]
(A) a piston that is slidably fitted in the cylinder tube to separate the inside of the cylinder tube into two gas chambers; and (b) one end of the cylinder tube that is provided integrally with the piston. A piston rod projecting outward from the parking brake pedal, and the piston rod is disposed between the parking brake pedal and the position fixing member, and the piston rod is relatively moved with respect to the cylinder tube as the parking brake pedal rotates. When the parking brake pedal is returned from the depressed position to the original position by being pushed and pulled out, a large damper action is generated due to the increase and decrease of the gas pressure due to the volume change of the two gas chambers. When depressing the parking brake pedal, increase the flow rate of gas between the two gas chambers. A gas type damper device having a reduced operation reaction force, comprising: (c) a fitting portion that is integrally provided on the piston rod, and in which the piston is fitted so as to be relatively movable in the axial direction; d) A gas passage provided near the boundary between the fitting portion and the piston so as to allow the gas to flow between the two gas chambers, and (e) integrally provided on the piston rod. A retainer that defines a moving end of the piston when the piston is moved relative to the piston rod when the pedal is returned, and (f) is fitted to the outer peripheral surface of the fitting portion, and is retained when the pedal is returned. When the piston is moved relative to the piston rod, the gas is squeezed between the piston and the retainer to hinder the flow of gas through the gas passage, while the stepping operation is performed. Wherein the piston is moved relative to the opposite direction with respect to the piston rod, and having a O-ring to permit the flow of gas to form a gap between the piston.

[0006]

In the damper device for the parking brake pedal, a gap is formed between the piston and the O-ring due to the relative movement of the piston and the piston rod when the parking brake pedal is depressed. Since the gas is allowed to flow between the two gas chambers through the gas passage provided at or near the boundary portion between the fitting portion of the piston rod and the piston, the piston pressure based on the differential pressure between the two gas chambers The movement resistance, that is, the operation reaction force is small, and the parking brake pedal can be easily depressed. On the other hand, when the parking brake pedal is returned from the depressed position to the original position,
The O-ring is pinched between the piston and the retainer due to the relative movement of the piston and the piston rod, and the flow of gas through the gas passage is blocked. When the flow of gas is obstructed in this way, the gas pressure greatly increases and decreases with the change in volume of the two gas chambers, and the differential pressure increases the movement resistance of the piston, resulting in a large damper action.

In the damper device of the present invention, the piston is arranged so as to be movable relative to the piston rod, and the gas is passed through the gas passage provided between the piston and the piston rod (fitting portion). The device is simply and inexpensively configured as a whole, because it is sufficient to provide an O-ring that allows the gas to flow while being pinched between the retainer and the retainer by the movement of the piston when the pedal is returned.

In Japanese Utility Model Laid-Open No. 6-81852, a damper device of a piston movable type is also described, but this does not form a sufficient gap between the O-ring and the piston even during the stepping operation, Since a large damper action is generated bidirectionally, the problem to be solved is completely different from the present invention, and the configuration and action effect are substantially different.

[0009]

[Second Means for Solving the Problems] The second invention is
(A) a piston that is slidably fitted in the cylinder tube to separate the inside of the cylinder tube into two gas chambers; and (b) one end of the cylinder tube that is provided integrally with the piston. A piston rod projecting outward from the parking brake pedal, and the piston rod is disposed between the parking brake pedal and the position fixing member, and the piston rod is relatively moved with respect to the cylinder tube as the parking brake pedal rotates. When the parking brake pedal is returned from the depressed position to the original position by being pushed and pulled out, a large damper action is generated due to the increase and decrease of the gas pressure due to the volume change of the two gas chambers. When depressing the parking brake pedal, increase the flow rate of gas between the two gas chambers. (C) A retainer in which the piston is axially immovable relative to the piston rod and a predetermined axial dimension relative to the retainer. And a piston body integrally provided with a small diameter portion so as to form an annular groove in the outer peripheral portion of the boundary with the retainer while the pedal is returned to the retainer when the pedal is returned. While consists of
(D) a gas passage provided near the boundary between the retainer and the piston body so as to allow the gas to flow between the two gas chambers, and (e) arranged in the annular groove, By being pinched between the retainer and the piston main body at the time of pedal return, while blocking the flow of gas through the gas passage, when separated from the retainer together with the piston main body during the stepping operation,
It is characterized by having an O-ring which forms a gap between the retainer and the passage of gas.

[0010]

In the damper device for the parking brake pedal as described above, when the parking brake pedal is stepped on, the O provided in the annular groove is operated.
The ring is separated from the retainer together with the piston body, and a gap is formed between the ring and the retainer, so that a gas is provided between the two gas chambers through a gas passage provided at or near the boundary between the piston body and the retainer. Is allowed to flow, the movement resistance of the piston based on the pressure difference between the gas chambers, that is, the operation reaction force is small, and the parking brake pedal can be easily depressed. On the other hand, when the parking brake pedal is returned from the depressed position to the original position, the O-ring is pinched between the piston body and the retainer due to the relative movement of the piston body and the piston rod, and the gas flow through the gas passages. Therefore, as in the first aspect of the invention, the movement resistance of the piston increases and a large damper action occurs.

Here, in the damper device of the present invention, the piston is provided with a retainer that cannot move relative to the piston rod.
A piston body that is movable relative to the retainer is provided, a gas passage is provided near the boundary between the retainer and the piston body, and an annular groove is formed at the outer peripheral portion of the boundary by the small diameter portion of the piston body. Since only the ring needs to be provided, the device as a whole is simple and inexpensive. Further, since the O-ring can also serve as a seal member that hermetically seals between the piston and the cylinder tube, the device can be further simplified. Furthermore, since the annular groove in which the O-ring is mounted is made up of two members, the retainer and the piston body, when these are made of a resin material, die cutting is performed in the axial direction and the parting line (P
By molding the retainer and the piston main body so that the burr caused by L) does not occur on the inner surface of the annular groove, damage to the O-ring due to the burr can be avoided.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a front view showing a damper device (hereinafter, simply referred to as a damper device) 10 for a parking brake pedal, which is an embodiment of the first invention, with a part cut away. The damper device 10 includes a substantially cylindrical cylinder tube 14, and a piston that is fitted into the cylinder tube 14 so as to be slidable in the axial direction and separates the inside of the cylinder tube 14 into two left and right air chambers 30 and 32 in the drawing. 12
And a piston rod 16 and the like which is provided integrally with the piston 12 and projects outward from one end of the cylinder tube 14, that is, the right end in FIG. As shown in FIG. 2, the damper device 10 is disposed in a vehicle foot-operated parking brake operating device 52, and the piston rod 16 is pulled out as the parking brake pedal 56 turns back when the parking brake is released. In doing so, it acts as a damper. The air chambers 30 and 32 correspond to gas chambers. In addition,
FIG. 1 shows a state in which the piston rod 16 has been moved to the moving end on the pushing side.

FIG. 3 is an enlarged cross-sectional view of an essential part showing the vicinity of the piston 12 in FIG. 1 in detail. The piston rod 16 is made of metal such as steel, and a part of its left end side is a main body part 16a. And has a fitting portion 16b and a threaded portion 16c that are successively smaller in diameter than the fitting portion 1
6b is fitted so as to penetrate the central portion of the piston 12, and an O-ring 18 is fitted thereto.
The piston 12 and the O-ring 18 are integrated with the piston rod 16 by fastening the nut 20 to the male screw 6c. The axial dimension of the fitting portion 16b, that is, the dimension A sandwiched between the flange portion 20a of the nut 20 and the main body portion 16a is more predetermined than the dimension when the piston 12 and the O-ring 18 are brought into close contact with each other in the axial direction. The dimension is set to be long, and the piston 12 is relatively movable in the axial direction by the predetermined dimension. A seal ring 22 such as an O-ring is provided on the outer peripheral portion of the piston 12 to hermetically seal the space between the piston 12 and the cylinder tube 14, and the air chambers 30 and 32 are formed on both sides of the piston 12. There is. In this embodiment, the nut 20 is the piston 12
One of the moving ends, that is, the retainer that defines the moving end when the pedal is returned. Further, the stepped portion between the main body portion 16a and the fitting portion 16b functions as a stopper that defines the other moving end of the piston 12.

The piston 12 is made of synthetic resin and has a communication hole 26 having an orifice 24 penetrating therethrough in the axial direction, and has a predetermined flow resistance determined by the cross-sectional area and length of the orifice 24. The left and right air chambers 30, 32 are communicated with each other. On the other hand, between the piston 12 and the fitting portion 16b of the piston rod 16, an air gap having a predetermined flow cross-sectional area is set by appropriately setting a fit-eye relationship such that the fit between them is appropriate. A passage 28 is formed so as to allow the air to flow between the air chambers 30 and 32 in an appropriate amount. The piston 12 is the body portion 16 of the piston rod 16.
In the state shown in FIG. 3 in which the gap is formed between the O-ring 18 and the O-ring 18, the O-ring 18 serves to seal between the piston 12 and the piston rod 16. However, air can flow through the air passage 28. However, as shown in FIG. 4, when the piston 12 is substantially positioned at the moving end on the side of the nut 20, and the O-ring 18 is pinched between the flange portion 20a of the nut 20 and the taper portion 12a of the piston 12, The space between the piston 12 and the piston rod 16 is sealed and the air passage 28
The flow of air through the is blocked. The air passage 28 corresponds to a gas passage.

Returning to FIG. 1, the cylinder tube 14 is made of a metal such as steel or aluminum, and the other end, that is, the left end in FIG. 1, is located on the end side as is apparent from the perspective view of FIG. A part is crushed in a direction substantially perpendicular to the axis to form a substantially flat crushed portion 34, which is closed, while a rod seal member 36 is provided at the opposite right end portion.
Is fixed. The rod seal member 36 is composed of a pair of cylindrical members 38, 40 fixed to the cylinder tube 14 and seal rings 42, 44 such as O-rings arranged on the inner peripheral side and the outer peripheral side thereof. 1
Piston rod 1 while allowing protrusion and retraction movement of 6
6 and 6 are hermetically sealed.

Insertion holes 48 are provided at both longitudinal ends of the damper device 10, that is, at the crushing portion 34 of the cylinder tube 14 and the connecting portion 46 at the right end of the piston rod 16 in FIG.
And 50 are provided respectively, and the crushed portions 3 are provided.
It is arranged between the bracket 54 and the parking brake pedal 56 in the stepping type parking brake operating device 52 of FIG. The crushing portion 34 and the connecting portion 46 are connected to the connecting pins 58 and 60, respectively.
The piston rods 16 are relatively rotatably connected to each other, and the distance between the connecting pins 58 and 60 is changed in accordance with the rotation of the parking brake pedal 56, so that the piston rod 16 is pushed relative to the cylinder tube 14. Driven by a drawer. The bracket 54 corresponds to a position fixing member.

In the foot-operated parking brake operating device 52 of FIG. 2, the parking brake pedal 56 rotatably supported by the rotating shaft 62 is stepped clockwise from the original position shown in the drawing. When operated, the ratchet 6 provided on the parking brake pedal 56
The meshing of 4 and the pole 66 maintains the tightened state of the brake cable 68 connected to the parking brake pedal 56, and the parking brake is activated. At this time, the piston rod 16 of the damper device 10 is pushed into the cylinder tube 14 as shown in FIG. 1, for example, as the parking brake pedal 56 rotates. From this state, the release wire 70 is pulled by the operation of a release operation member (not shown), and the release lever 72
When the pole 66 rotates and the pawl 66 is rotated in the disengagement direction against the biasing force of the tension coil spring 74, the pawl 66 and the ratchet 64 are disengaged, and the parking brake 68 follows the tension of the brake cable 68. Pedal 5
6 is rotated toward the original position defined by the stopper 76, and in the damper device 10, the piston rod 16 is pulled out from the cylinder tube 14.

Next, the operation of the damper device 10 will be described. When the parking brake pedal 56 is depressed from the original position to push the piston rod 16 into the cylinder tube 14 and the piston 12 is moved to the collapsed portion 34 side of the cylinder tube 14, that is, the other end portion side, the piston 12 Since the air pressure in the air chamber 30 on the other end side increases due to the decrease in volume, and the air pressure in the air chamber 32 on the one end side decreases due to the increase in volume, the piston due to the differential pressure between the air chambers 30 and 32 is used. Twelve movement resistances are added to the parking brake pedal 56 as stepping resistances. At this time, due to the relative movement between the piston 12 and the piston rod 16 based on the sliding resistance between the seal ring 22 and the cylinder tube 14 and the movement resistance due to the differential pressure, as shown in FIG.
8 and a gap is formed between the piston 8 and the air passage 2 provided between the fitting portion 16b of the piston rod 16 and the piston 12.
The air is allowed to flow from the air chamber 30 to the air chamber 32 through 8. Therefore, the above-mentioned differential pressure is reduced together with the flow of air through the communication hole 26, the movement resistance of the piston 12, that is, the operation reaction force is reduced, and the parking brake pedal 56 can be easily depressed.

On the other hand, the brake cable 6 is released by the release operation.
When the parking brake pedal 56 is returned from the depressed position to the original position according to the tension of 8, the piston rod 16 is pulled out from the cylinder tube 14,
When the piston 12 is moved to the rod seal member 36 side of the cylinder tube 14, that is, one end side,
The air pressure in the air chamber 32 increases due to the volume decrease, and the air pressure decreases in the air chamber 30 due to the volume increase, and the return speed of the parking brake pedal 56 is limited by the movement resistance of the piston 12 due to the pressure difference. At this time, the piston 1 based on the sliding resistance between the seal ring 22 and the cylinder tube 14 and the movement resistance due to the above-mentioned pressure difference.
As a result of the relative movement between 2 and the piston rod 16 in the opposite direction to the above, O between the piston 12 and the nut 20 as shown in FIG.
The ring 18 is pinched, and the flow of air in the air passage 28, that is, the inflow of air from the air chamber 32 to the air chamber 30 is blocked. In this way, if the air flow is hindered,
The flow of air between the two air chambers 30 and 32 is exclusively through the communication hole 26, and the respective air pressures greatly increase and decrease.
The movement resistance of No. 2 becomes large, and a large damper action occurs. Due to this damper action, abrupt return of the parking brake pedal 56 to the original position is avoided, impact noise and vibration at the time of collision with the stopper 76 that defines the original position is reduced, and the driver's foot or the like is slammed. There is no need to worry.

As described above, according to the damper device 10 of this embodiment, a sufficient damper action is generated when the parking brake pedal 56 is returned, while the reaction force thereof is reduced when the parking brake pedal 56 is depressed. Will be easier. Particularly, in the present embodiment, the piston 12 is arranged so as to be movable relative to the piston rod 16, and air is circulated through an air passage 28 provided between the piston 12 and the fitting portion 16b of the piston rod 16. At the same time, it is only necessary to provide the O-ring 18 which obstructs the air flow by being pinched between the nut 20 and the piston 12 when the pedal is returned.
0 is configured simply and inexpensively as a whole.

Next, another embodiment of the first invention will be described.
In addition, the same reference numerals are given to the portions common to the above-described embodiments and the portions that can be regarded as substantially the same, and the description thereof will be omitted.

A damper device (hereinafter, simply referred to as a damper device) 80 for the parking brake pedal shown in FIG. 6 includes a piston rod 82 and a retainer 84 instead of the piston rod 16 and the nut 20. As shown in the sectional view of the main part of FIG.
2 is a main body 82a, similar to the piston rod 16;
It has a fitting portion 82b, and an engaging groove 82c is provided on the tip side of the fitting portion 82b. The fitting portion 82b includes the piston 12, the O-ring 18, and the retainer 84.
The flange portion 84a is fitted. Retainer 8
Reference numeral 4 denotes a synthetic resin having a substantially bottomed cylindrical shape having the flange portion 84a on the opening side and having flexibility, and is formed at a plurality of positions around the axis, that is, 180 ° pitch in this embodiment. A pair of claw portions 84b are provided at two locations, the claw portions 84b being reduced in diameter and extending toward the inner peripheral side. FIG. 8 is a side view of the retainer 84 as viewed from the left side of FIG. 7, that is, the bottom portion 84c side. The claw portion 84b is the fitting portion 8 of the piston rod 82.
By inserting 2b from the flange portion 84a side until it substantially contacts the bottom portion 84c, it is elastically deformed in the radial expansion direction and then engaged with the engaging groove 82c. The flange portion 84a is positioned at a predetermined axial position together with the bottom portion 84c by preventing the flange portion 84a from coming off from the portion 82b. The connecting portion 86 on the right end side of the piston rod 82 in FIG. 6 is one in which the end portion of the main body portion 82a is processed into a flat shape by a crushing press. Has been drilled.

In the mounted state of the retainer 84, a dimension obtained by subtracting the fitting margin of the retainer 84 from the axial dimension of the fitting portion 82b, that is, the flange portion 84a and the main body portion 82.
The dimension B sandwiched between a and is the piston 12 and the O-ring 18
It is set to be longer than the axial dimension when they are brought into close contact with each other by a predetermined dimension, and the piston 12 is relatively movable in the axial direction by the predetermined dimension. FIG. 7 shows the piston 12
Is located at the moving end of the piston rod 82 on the side of the main body portion 82a, and the air chamber 28 is formed by the air passage 28 formed between the piston 12 and the fitting portion 82b of the piston rod 82. , 32 is allowed to flow, while the piston 12 is located at the moving end on the retainer 84 side as shown in FIG.
In a state where the O-ring 18 is clamped between 4a and the tapered portion 12a of the piston 12, the piston 12 and the piston rod 82 are sealed and the flow of air through the air passage 28 is obstructed.

Also in the damper device 80 of the present embodiment, when the parking brake pedal 56 is depressed, the relative movement of the piston 12 and the piston rod 82 results in FIG.
As described above, since a gap is formed between the piston 12 and the O-ring 18 and air is allowed to flow through the air passage 28 between the air chambers 30 and 32, the pressure difference between the air chambers is reduced. While the movement resistance of the piston 12, that is, the operation reaction force, decreases, when the parking brake pedal 56 returns, the O-ring 18 is formed between the piston 12 and the retainer 84 as shown in FIG. 9 due to the relative movement of the piston 12 and the piston rod 82. Since the air is circulated in the air passage 28 by being pinched, the movement resistance of the piston 12 increases, and a large damper action is generated, the same effect as the damper device 10 can be obtained. On the other hand, the piston rod 82 of the present embodiment has a lower manufacturing cost than the piston rod 16 having the threaded portion 16c and the connecting portion 46, and the retainer 84 can be attached to the piston rod 82 with one-touch operation very easily. Since the assembling cost is lower than that of No. 20, the device can be configured to be cheaper and lighter.

Next, an embodiment of the second invention will be described.
A damper device (hereinafter, simply referred to as a damper device) 100 of the parking brake pedal of FIG. 10 is fitted into the cylinder tube 14 and the cylinder tube 14 so as to be slidable in the axial direction. The left and right air chambers 30 and 32 are separated from each other by a piston 102, the piston rod 82 integrally provided on the piston 102, and the like. FIG. 11 is an enlarged cross-sectional view of an essential part of the vicinity of the piston 102 in FIG. 10 showing a state where the piston rod 82 is moved to the moving end on the pushing side. The piston 102 is composed of a retainer 104 that is fitted and fitted to the fitting portion 82b of the piston rod 82, and a piston body 106 that is axially fitted to the outer peripheral side of the retainer 104 in advance. Are made of synthetic resin material. The piston body 106 has a small diameter portion 106 a facing the flange portion 104 a of the retainer 104.
An O-ring 108 having a diameter substantially the same as that of the seal ring 22 is fitted on the outer peripheral side of a. The O-ring 108 hermetically seals between the O-ring 108 and the cylinder tube 14, and the air chamber 3 is provided on both sides of the piston 102.
0 and 32 are formed.

The left side portion of the retainer 104 in FIG. 11 has a bottomed cylindrical shape similar to that of the retainer 84 and is provided with a claw portion 104b similar to the claw portion 84b. The engagement groove 82
When the claw portion 104 is engaged with c, the retainer 104 is mounted on the fitting portion 82b of the piston rod 82 so as to be relatively immovable in the axial direction. On the other hand, retainer 1
The part on the right side in FIG.
6, the flange portion 104a having a recess 110 for accommodating the small diameter portion 106a, the fitting portion 82b of the piston rod 82 from the flange portion 104a, and the piston body 1
A plurality of engaging portions 104c are provided in the circumferential direction so as to extend into a cylindrical space in the middle of 06, and in this embodiment, four engaging portions 104c are provided at a pitch of 90 °. Engaging part 10
A projection 112 is provided at the tip of 4c so as to project to the outer peripheral side, while the large diameter portion 106b on the right side in FIG. 11 of the piston body 106 is provided with a retainer 104 at the right end on the inner peripheral side.
An annular engagement groove 11 having a diameter larger than that of a portion axially fitted to
4 is provided, and the engaging portion 104 is provided in the engaging groove 114.
By engaging the protrusion 112 of c, the piston body 106 is prevented from coming off from the retainer 104, and both are integrated. When engaging, retainer 1
Since it is necessary for the engaging portion 104c of No. 04 to be flexibly deformed toward the inner peripheral side, they are integrated in advance prior to attachment to the piston rod 82. FIG. 12 is a right side view of the piston 102 before being attached to the piston rod 82.

The axial dimension C from the bottom surface of the recess 110 of the retainer 104 to the engaging end of the projection 112 is determined by the end of the small diameter portion 106a of the piston body 106 to the engaging groove 114.
It is set to be longer than the dimension up to the engagement end by a predetermined dimension, and the piston body 106 is relatively movable in the axial direction by the predetermined dimension. In the state where the retainer 104 and the piston body 106 are integrated, an appropriate amount of air flows between the left and right air chambers 30 and 32 along the boundary between them, that is, the fitting portion between the recess 110 and the small diameter portion 106a. An air passage 116 is provided to allow the air to flow therethrough. The air passage 116 is formed by appropriately setting a fitting relationship such that the recess 110 and the small-diameter portion 106a are appropriately fitted to each other, and the retainer 104 and the cylinder 104 are connected to the air chamber 30 side. The engaging portions 104 of the retainer 104 are connected to the air chamber 32 side while being communicated with each other through the gap between the retainer 104 and the tube 14.
It is made to communicate through the gap between c.

The inner peripheral diameter of the recess 110 and the engaging portion 104c
Of the piston main body 106
The relative movement of is well guided. Also, the retainer 10
4 and the piston body 106 are integrated,
The outer peripheral side cylindrical portion of the flange portion 104a and the large diameter portion 10
An annular groove 118 is formed on the outer peripheral side of the small diameter portion 106a at an axial boundary with the 6b, and the O-ring 108 is disposed in the annular groove 118. Small diameter part 106
A positioning groove 120 having a smaller diameter is formed in a in order to position the O-ring 108 at a predetermined position near the large diameter portion 106b, and the groove depth thereof is small after the molding.
It is set within a range in which a can be punched in the axial direction while elastically deforming a.

The piston body 106 is the piston rod 82.
Of the O-ring 108 substantially at the moving end on the main body 82a side of the
A gap is formed between the retainer 104 and the retainer 104 in FIG.
In this state, the O-ring 108 seals between the piston body 106 and the cylinder tube 14, but does not seal between the piston body 106 and the retainer 104. It can be distributed. However, as shown in FIG. 13, the piston body 106 is substantially positioned at the moving end on the side closer to the retainer 104, and the O-ring 108 is sandwiched between the flange portion 104 a of the retainer 104 and the large diameter portion 106 b of the piston body 106. When pressed, the piston body 106 and the retainer 104
The air gap is sealed and the flow of air through the air passage 116 is blocked.

In such a damper device 100,
When the piston 102 is moved to the other end side of the cylinder tube 14 by the depression operation of the parking brake pedal 56, and the movement resistance due to the differential pressure between the air chambers 30 and 32 is applied to the parking brake pedal 56 as the depression resistance. As shown in FIG. 11, the piston body 106 and the O-ring 108 are separated from the retainer 104 by the pressure difference and the sliding resistance between the cylinder tube 14 and the O-ring 108, and a gap is created between the retainer 104 and the O-ring 108. And the retainer 104 and the piston body 1 are formed.
The air is allowed to flow from the air chamber 30 into the air chamber 32 through the air passage 116 between the air chamber 30 and the air chamber 06. Since the piston main body 106 is provided with a positioning groove 120 so that the O-ring 108 and the piston main body 106 can be moved integrally, the retainer 104 and the O-ring 108 are moved together with the movement of the piston main body 106. A gap is surely formed between them, and air circulation is allowed. For this reason,
The differential pressure is reduced and the movement resistance of the piston 102, that is, the operation reaction force is reduced.
It becomes easy to step on.

On the other hand, when the parking brake pedal 56 is returned to its original position, the piston 102 is moved toward one end of the cylinder tube 14 to move the air chambers 3 into each other.
When the return speed of the parking brake pedal 56 is limited by the movement resistance of the piston 102 due to the differential pressure between 0 and 32, the differential pressure and the sliding resistance between the cylinder tube 14 and the O-ring 108 cause a difference in pressure. As described above, the piston body 106 and the O-ring 108 are brought close to the retainer 104, and the O-ring 1 is provided between the large diameter portion 106b of the piston body 106 and the flange portion 104a of the retainer 104.
08 is pinched, and the air flow in the air passage 116 is hindered. Therefore, the other portion, for example, the fitting portion 8
Only the air flows through the gap between 2b and the retainer 104, and the increase of the differential pressure between both air chambers is maintained, so that a large damper action is obtained.

In this way, the damper device 100 of this embodiment is
According to this, while the damper action is sufficiently generated when the parking brake pedal 56 is returned, the reaction force thereof is reduced when the parking brake pedal 56 is depressed, which facilitates the operation. In particular, in this embodiment, the retainer 104
The piston 102 is composed of a piston body 106 that is movable relative to the retainer 104, and the retainer 1
04 along the boundary between the piston body 106 and the air passage 1
16 is provided, and the O-ring 108 is provided by forming the annular groove 118 in the outer peripheral portion of the boundary by the small diameter portion 106a, so that the apparatus as a whole is simple and inexpensive. The O-ring 108 is the piston 102.
Since it can also serve as a sealing member that hermetically seals between the cylinder tube and the cylinder tube, the device can be further simplified.

Further, in this embodiment, the annular groove 118 in which the O-ring 108 is mounted is constituted by the retainer 104 and the piston body 106, and the piston body 1
Although the annular positioning groove 120 is provided in the small diameter portion 106a of 06, the groove depth is determined within a range in which it can be die-cut in the axial direction while being elastically deformed after molding.
The burr caused by the parting line (PL) has an annular groove 1
The piston body 106 and the retainer 104 can be molded so that they do not occur on the inner surface of 18, and the O-ring 108 by the burr is formed.
Damage is avoided.

Next, another embodiment of the second invention will be described.
FIG. 14 is a sectional view of an essential part showing a mode different from that of the annular groove 118 in the embodiment of FIG. 11, and the piston main body 124 constituting the piston 122 has a positioning groove in the small diameter portion 106 a of the piston main body 106. 120
While having a small diameter portion 124a having substantially the same diameter as that of the retainer 126, the flange portion 126a of the retainer 126 has a small diameter portion 12a.
Corresponding to 4a, it has a recess 128 whose outer diameter is smaller than that of the recess 110. Those small diameter parts 124
An air passage 130 is provided between a and the recess 128 in the same manner as the air passage 116. Other than the above, FIG.
Similar to the first embodiment, the claw portion 126b of the retainer 126 is engaged with the engaging groove 82c of the piston rod 82, and the projection 112 at the tip of the engaging portion 126c of the retainer 126 is larger than the piston body 124. It is engaged with the engagement groove 114 of the diameter portion 124b.

The O-ring 108 is arranged in an annular groove 132 formed between the flange portion 126a of the retainer 126 and the large diameter portion 124b of the piston body 124. In this case, the O-ring 108 is not particularly positioned as in the case of the embodiment of FIG. 11 in which the positioning groove 120 is provided, but the piston rod 82 is pushed into the cylinder tube 14 and the O-ring 108 of FIG. As described above, when the piston body 124 is moved to the moving end of the piston rod 82 on the side of the body portion 82a, the O-ring 108 is slid against the cylinder tube 14 to cause the piston body 12 to move.
4 is moved together with the retainer 126, a gap is formed between the O-ring 108 and the retainer 126 to connect the air passage 130 to the air chamber 30 side.

Also in this embodiment, the parting line (P
The piston main body 124 and the retainer 126 can be molded so that the burr resulting from L) does not occur on the inner surface of the annular groove 132, and the O-ring 108 can be prevented from being damaged by the burr.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, in the above embodiment, the fitting portions 16b, 8
2b and piston 12 fitting and retainer 104 recess 1
Although the air passages 28, 116 and the like are provided by setting a fitting relationship such that the fitting of 10 and the small diameter portion 106a of the piston main body 106 is an appropriate clearance, a groove is formed in one of a pair of fitting members. An air passage may be formed by forming a through hole or a through hole, and the flow rate of air is appropriately changed according to the performance required for the damper device. Similar to the communication hole 26 of the embodiment of FIG. 1, a communication means that always allows air to flow with a predetermined flow resistance may be added to the embodiment of FIG. 10, or the communication hole 26 may be omitted from the piston 12. It doesn't matter.

Further, in the above embodiment, the fitting portions 16b, 82
Although b is integrally formed with the piston rods 16 and 82 so that the nut 20 and the retainers 84 and 104 are integrally provided, the piston rod and the fitting portion are formed separately or the fitting portion is formed. The retainer and the retainer may be integrally formed. For example, a bolt-shaped member that also serves as the retainer and the fitting portion may be screwed and fixed to the piston rod.

In the above embodiment, the piston rod 1
Although 6, 82 are made of metal, they can be made of other materials such as synthetic resin.

Further, in the above embodiment, the retainers 84, 10
By engaging the claw portions 84b, 104b, etc. provided on the No. 4 and the like with the engaging groove 82c of the piston rod 82,
Although each retainer was integrally provided on the piston rod 82 so as not to be relatively movable in the axial direction, other means for fixing the retainer to the piston rod, such as disposing an E-shaped retaining ring or a spring pin, is not provided. Various means may be employed.

Further, in the embodiment shown in FIG. 11, the retainer 1 is used.
Although the piston body 106 was fitted in the recess 110 of 04, and the relative movement of the predetermined size defined by the protrusion 112 was made possible, the fitting form of the retainer and the piston body may be changed appropriately, and The mode for defining the predetermined size of movement can be variously changed. The piston body may be directly fitted to the fitting portion 82b of the piston rod 82.

Further, in the embodiment shown in FIG. 11, the projection 112 is formed.
The engaging portion 104c of the retainer 104 provided with has been designed to be integrated with the retainer 104 and the piston body 106 by returning from the bending deformation toward the inner peripheral side. It is also possible to provide a projecting protrusion on the engaging portion 104c so as to engage with the piston body 106.

Further, in the above embodiment, when the parking brake pedal 56 is returned to the original position, the piston rod 16,
Although 82 is drawn out from the cylinder tube 14, the present invention can be similarly applied to a damper device in which the piston rod is pushed in when the parking brake pedal is returned.

In the above embodiment, the cylinder tube 1
4, the rod seal member 36 was disposed at one end and the crushed portion 34 was formed at the other end, but these are not essential in the present invention, and other members and other forms It does not matter even if it is replaced by.

Further, although the air damper device has been described in the above embodiment, it is possible to use a gas other than air.

Although not individually exemplified, the present invention can be carried out in variously modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a front view showing a damper device for a parking brake pedal, which is an embodiment of the first invention, with a part cut away;
It is a figure which shows the state at the time of depression operation of a parking brake pedal.

FIG. 2 is a cross-sectional view showing an example of a foot-operated parking brake operating device provided with the damper device of FIG.

3 is a cross-sectional view of main parts showing in detail the vicinity of a piston of the damper device of FIG.

FIG. 4 is a cross-sectional view of essential parts showing a state where the piston in the damper device of FIG. 1 moves relative to the piston rod when the pedal returns.

5 is a perspective view showing the other end shape of the cylinder tube in the damper device of FIG. 1. FIG.

FIG. 6 is a front view showing a partially cutaway view of another embodiment of the first invention, showing a state when the parking brake pedal is depressed.

FIG. 7 is a cross-sectional view of main parts showing the vicinity of the piston of the damper device of FIG. 6 in detail.

FIG. 8 is a left side view of the retainer in FIG.

9 is a cross-sectional view of relevant parts showing a state where the piston in the damper device of FIG. 6 moves relative to the piston rod when the pedal returns.

FIG. 10 is a front view showing a part of the second embodiment of the present invention with a part cut away, showing a state when the parking brake pedal is depressed.

11 is a cross-sectional view of main parts showing in detail the vicinity of the piston of the damper device of FIG.

FIG. 12 is a right side view of the piston before assembling in FIG.

13 is a cross-sectional view of relevant parts showing a state where the piston body of the damper device of FIG. 10 moves relative to the retainer when the pedal is returned.

FIG. 14 is a cross-sectional view of main parts showing a different aspect of the piston in the embodiment of FIG.

[Explanation of symbols]

10, 80, 100: Damper device for parking brake pedal 12, 102, 122: Piston 14: Cylinder tube 16, 82: Piston rod 16b, 82b: Fitting part 18, 108: O-ring 20: Nut (retainer) 28, 116, 130: Air passage (gas passage) 30, 32: Air chamber (gas chamber) 56: Parking brake pedal 84, 104, 126: Retainer 106, 124: Piston body 106a, 124a: Small diameter portion 118, 132: Annular groove

Claims (2)

[Claims] 1. A piston, which is slidably fitted in a cylinder tube to separate the inside of the cylinder tube into two gas chambers, and a piston which is integrally provided on the piston and which is provided at one end of the cylinder tube. A piston rod protruding outward is provided between the parking brake pedal and a position fixing member, and the piston rod is pushed relative to the cylinder tube as the parking brake pedal rotates. When the parking brake pedal is returned from the depressed position to the original position by being pulled out, a large damper action is generated due to an increase / decrease in gas pressure due to the volume change of the two gas chambers. When depressing the brake pedal, increase the flow rate of gas between the two gas chambers to increase the reaction force. A reduced gas type damper device, which is provided integrally with the piston rod and in which the piston is fitted so as to be relatively movable in the axial direction, and a gas between the two gas chambers. Is provided in the vicinity of the boundary between the fitting portion and the piston so as to allow the fluid to flow, and is integrally provided on the piston rod, and when the pedal returns, the piston moves with respect to the piston rod. And a retainer that defines the moving end of the piston when the piston is moved relative to the piston rod, and the piston is moved relative to the piston rod when the pedal is returned. While being pinched between the piston and the retainer, the flow of gas through the gas passage is obstructed, while the piston moves the piston rod during the stepping operation. A damper device for a parking brake pedal, which has an O-ring that forms a gap between the piston and the piston and allows the gas to flow therethrough when the damper device is relatively moved in the opposite direction. 2. A piston, which is slidably fitted in the cylinder tube to separate the inside of the cylinder tube into two gas chambers, and a piston which is integrally provided on the piston and which is provided at one end of the cylinder tube. A piston rod protruding outward is provided between the parking brake pedal and a position fixing member, and the piston rod is pushed relative to the cylinder tube as the parking brake pedal rotates. When the parking brake pedal is returned from the depressed position to the original position by being pulled out, a large damper action is generated due to an increase / decrease in gas pressure due to the volume change of the two gas chambers. When depressing the brake pedal, increase the flow rate of gas between the two gas chambers to increase the reaction force. A miniaturized gas damper device, in which the piston is arranged on the piston rod so as to be immovable in the axial direction, and arranged so as to be relatively movable in the axial direction by a predetermined dimension with respect to the retainer. While being brought close to the retainer when the pedal is returned, the piston main body is integrally provided with a small diameter portion so as to form an annular groove in the outer peripheral portion of the boundary with the retainer, A gas passage provided near the boundary between the retainer and the piston body so as to allow gas to flow between the two gas chambers; and a retainer provided in the annular groove, which is provided when the pedal returns. By being sandwiched between the piston body and the piston body, the flow of gas through the gas passage is obstructed, while the piston body and the retainer are operated during the stepping operation. When brought away from Na, the damper device of the parking brake pedal and having an O-ring to form a gap allowing passage of gas between said retainer.