Damper device

Abstract

Provided is a damper device that attains a high damper braking force by sufficiently deforming a friction member in the radial direction when a piston moves to a damper braking direction. This damper device 10 comprises: a cylinder 20; a rod 30; a piston 40 provided with a ring-shaped groove 50; a sealing ring 60; a friction member 70; and a seal unit. The seal ring 60 presses the friction member 70 to increase the diameter thereof, causing the outer peripheral surface of the friction member 70 to be pressed against the inner peripheral surface of the cylinder 20 when the piston 40 moves in a damper braking direction F1. The friction member 70 is configured so as to have a smaller diameter than the inner peripheral surface of the cylinder 20 when not under pressure from the seal ring 60.

Description

Technical Field

[0001] The present invention relates to a damper device used for braking, such as the opening and closing operation of a glove box of an automobile.

Background Art

[0002] For example, a damper device may be used in a glove box of an automobile to suppress the sudden opening of the lid and allow it to open gently.

[0003] As such a damper device, Patent Document 1 below describes a damper comprising a piston having a rod and a housing for accommodating the piston. The piston includes a seal member against the inner wall of the housing and a slider slidably provided with respect to the piston and in contact with the inner wall of the housing. When braking force is generated, the slider presses against the seal member, causing the portion of the seal member in contact with the inner wall of the housing to deform outwardly of the housing.

[0004] Further, the seal member has a skirt-like portion extending toward the open end side of the housing, and this skirt-like portion serves as the portion in contact with the inner wall of the housing. Furthermore, the slider has a base disposed on the outer periphery of the rod and a lip extending obliquely outward from the base toward the open end of the housing. When the piston moves forward (when moving in the damper braking direction), the slider is difficult to move in this forward movement direction due to the shape of the lip, so that the shoulder of the slider is pressed against the terminal of the skirt-like portion of the seal member (see paragraph 0026 of Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the case of the damper of Patent Document 1 described above, when the piston moves forward, the tip of the lip extending obliquely outward contacts the inner wall of the housing, making it difficult for the slider to move in the forward direction. That is, the slider presses against the sealing member only by the frictional force of the lip tip against the inner wall of the housing, so it is difficult to sufficiently deform the sealing member and obtain a high braking force.

[0007] Therefore, an object of the present invention is to provide a damper device capable of obtaining a high damper braking force by sufficiently deforming a friction member in the radial direction when a piston moves in the damper braking direction.

Means for Solving the Problems

[0008] To achieve the above object, the present invention is a damper device attached between a pair of members that approach and separate from each other, and applies a braking force when the pair of members approach or separate. It includes a cylinder having an opening at one end, a rod movably inserted into the cylinder through the opening, a piston connected to the rod and having an annular groove formed on its outer periphery, a seal ring disposed axially movably on the damper braking direction side of the annular groove and pressed against the inner peripheral surface of the cylinder, and a friction member disposed on the return direction side opposite to the damper braking direction with respect to the seal ring in the annular groove. A seal portion is formed between the cylinder and the piston by the seal ring and the friction member, or by the seal ring. An air chamber is formed in the cylinder through the seal portion. The seal ring presses and expands the diameter of the friction member when the piston moves in the damper braking direction, and presses the outer peripheral surface of the friction member against the inner peripheral surface of the cylinder. The friction member is configured to be smaller than the dimension of the inner peripheral surface of the cylinder when the pressing force from the seal ring does not act.

Effects of the Invention

[0009] In the present invention, when the piston moves in the damper braking direction, due to the pressure change in the air chamber and the frictional force of the seal ring against the inner peripheral surface of the cylinder, the friction member is pressed against the seal ring, and the friction member can be sufficiently deformed. As a result, the outer peripheral surface of the friction member can be pressed against the inner peripheral surface of the cylinder. Consequently, in addition to the frictional force of the seal ring against the inner peripheral surface of the cylinder, the frictional force of the friction member against the inner peripheral surface of the cylinder can be generated, and a high damper braking force can be obtained.

Brief Description of the Drawings

[0010]

Figure 1

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Figure 10

Figure 11

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Mode for Carrying Out the Invention

[0011] (An Embodiment of the Damper Device) Hereinafter, with reference to the drawings, an embodiment of the damper device according to the present invention will be described.

[0012] The damper device 10 shown in FIGS. 1 and 2 is attached to a pair of members that approach and separate from each other, and applies a braking force when the pair of members approach or separate. For example, it can be used for braking, such as a glove box or a lid that is openably and closably attached to an opening of a housing provided in an instrument panel of an automobile. In the following embodiments, one member will be described as a fixed body such as a housing of an instrument panel, and the other member will be described as an opening / closing body such as a glove box or a lid that is openably and closably attached to an opening of the fixed body.

[0013] As shown in Fig. 1, the damper device 10 of this embodiment mainly comprises a cylinder 20 having an opening 23 at one end, a rod 30 movably inserted into the cylinder 20, a piston 40 connected to the rod 30 and having an annular groove 50 formed on its outer periphery, a seal ring 60 axially movably disposed on the damper braking direction F1 side of the annular groove 50 and pressed against the inner peripheral surface of the cylinder 20, a friction member 70 disposed on the return direction F2 side opposite to the damper braking direction F1 with respect to the seal ring 60 in the annular groove 50, and a retaining cap 90 attached to the opening 23 on one end side of the cylinder 20.

[0014] Further, when the piston 40 moves in the damper braking direction F1, the seal ring 60 presses the friction member 70 to expand its diameter and presses the outer peripheral surface of the friction member 70 against the inner peripheral surface of the cylinder 20. The friction member 70 is configured to be smaller than the dimension of the inner peripheral surface of the cylinder 20 when the pressing force from the seal ring 60 does not act thereon (this will be described in detail in the operation description hereinafter). Note that, in the case of this embodiment, the inner peripheral surface of the cylinder 20 means the inner peripheral surface of the wall portion 21 constituting the cylinder 20, and the same applies in the following description.

[0015] In the following description, "one end portion" or "one end" means one end portion or one end on the damper braking direction side of the damper device 10, and "the other end portion" or "the other end" means the other end portion or the other end on the return direction side opposite to the damper braking direction. Further, the "damper braking direction" in this embodiment means the direction in which the piston 40 moves away from the end wall 25 (see Fig. 10) of the cylinder 20 and the pulling amount of the rod 30 from the opening 23 of the cylinder 20 increases (see the arrow F1 in Fig. 10). Also, the "return direction opposite to the damper braking direction" (hereinafter also simply referred to as "damper return direction") in this embodiment means the direction in which the piston 40 approaches the end wall 25 of the cylinder 20 and the pushing amount of the rod 30 into the cylinder 20 increases (see the arrow F2 in Fig. 10).

[0016] Furthermore, in this damper device 10, a seal portion is formed between the cylinder 20 and the piston 40 by the seal ring 60 and the friction member 70. Also, an air chamber is formed in the cylinder 20 via the seal portion. In the case of this embodiment, an air chamber is formed in the cylinder 20 on the insertion direction side of the rod 30 from the seal portion.

[0017] In the case of this embodiment, as shown in FIG. 11, when the piston 40 is inserted into the cylinder 20, an outer diameter side protrusion 67 of the seal ring 60 described later is pressed against the inner peripheral surface of the cylinder 20, and a seal portion is formed to seal the gap between the cylinder 20 and the piston 40. That is, the outer diameter side protrusion 67 of the seal ring 60 and the inner peripheral surface of the cylinder 20 form the "seal portion" in the present invention.

[0018] Also, in a state where the friction member 70 is attached to the annular groove 50, the other end surface in the axial direction of the friction member 70 (contact surface 78 described later) abuts against the inner surface on the other end side in the axial direction of the annular groove 50 (inner surface 42a of the second side wall portion 42 described later) (see FIGS. 11, 13, and 15). As shown in FIG. 11, when the piston 40 moves in the damper braking direction F1, the other end in the axial direction of the seal ring 60 abuts against one end surface in the axial direction of the friction member 70 (pressing force receiving surface 80 described later). Thereby, a seal portion is formed to seal the gap between the cylinder 20 and the piston 40. That is, the other end in the axial direction of the seal ring 60, one end surface in the axial direction of the friction member 70, and the other end surface in the axial direction of the friction member 70 and the inner surface on the other end side in the axial direction of the annular groove 50 also form the "seal portion" in the present invention.

[0019] And in the damper device 10 of this embodiment, a first air chamber V1 is formed on the insertion direction side of the rod 30 of the cylinder 20 with the plurality of seal portions as described above as a boundary, and a second air chamber V2 is formed on the opening 23 side of the cylinder 20 (see FIG. 10). Note that the first air chamber V1 forms the "air chamber" in the present invention.

[0020] Further, when the piston 40 moves in the damper braking direction F1 by the above three seal portions, the internal space R in the annular groove 50 is sealed (see FIG. 11). Note that the internal space R of this annular groove 50 communicates with the first air chamber V1.

[0021] As shown in FIG. 1, the wall portion 21 of the cylinder 20 has an annular cross section perpendicular to its axial direction, which has a major axis and a minor axis, and is a thin cylindrical shape (a cylindrical shape presenting a thin box shape) with the major axis side being wide and the minor axis side being narrow. More specifically, the wall portion 21 linearly extends along the major axis direction and has a pair of major axis wall portions 21a, 21a arranged to face each other in parallel, and a pair of minor axis wall portions 21b, 21b that connect both ends of these major axis wall portions 21a, 21a and have an arcuate bent shape. One end side in the axial direction of the wall portion 21 is open, and an opening 23 is provided. Further, locking holes 23a, 23a are respectively formed in the facing major axis wall portions 21a, 21a at the periphery of the opening 23. Further, an end wall 25 is arranged at the other end in the axial direction of the wall portion 21 (it can also be said that the end wall 25 is arranged on the side opposite to the opening 23 of the wall portion 21), and the other end of the wall portion 21 is closed.

[0022] Further, a rotation support piece 27 forming a rotation hole 27a projects from the outer surface of the end wall 25 and the outer periphery of the wall portion 21 from one end in the axial direction. A rotation shaft (not shown) of one of the above-described members is rotatably inserted into a predetermined rotation hole 27a so that the outer periphery of the cylinder 20 is rotatably connected to one of the members.

[0023] As shown in FIG. 1, the anti-disengagement cap 90 has a rod insertion port 91 formed through its central portion so that the shaft portion 31 of the rod 30 can be inserted while being rotationally restricted, and can be inserted into the cylinder 20 with the rotation of the rod 30 restricted. Further, a plurality of locking protrusions 92 project from a predetermined position on the outer periphery of the anti-disengagement cap 90, and by locking each of the locking protrusions 92 to the corresponding locking holes 23a of the cylinder 20 (see FIG. 2), the anti-disengagement cap 90 is attached to the opening 23 of the cylinder 20 (see FIG. 10). This anti-disengagement cap 90 abuts against the piston 40 when the rod 30 is pulled out to the maximum from the opening 23 of the cylinder 20, preventing the rod 30 and the piston 40 from coming off from the cylinder 20.

[0024] Next, the rod 30 will be described.

[0025] This rod 30 is movably inserted into the cylinder 20 through the opening 23 of the cylinder 20 and slides in the axial direction of the cylinder 20 within the cylinder 20.

[0026] As shown in FIG. 1, the rod 30 of this embodiment has a shaft portion 31 having a prismatic shape extending long in one direction. A connecting piece 33 provided with a connecting hole 33a is provided at one end in the longitudinal direction of this shaft portion 31. A connecting shaft (not shown) of the other member described above is inserted into this connecting hole 33a, and the rod 30 is rotatably connected to the other member.

[0027] Next, the piston 40 will be described.

[0028] As shown in FIGS. 1 and 3, the piston 40 of this embodiment is continuously provided at the other end in the longitudinal direction of the rod 30, and an annular groove 50 is formed on its outer periphery, and is integrally formed with the rod 30.

[0029] Referring also to FIG. 10, this piston 40 is composed of a first side wall portion 41 and a second side wall portion 42 which are arranged to face each other in parallel, and a connecting wall portion 43 that connects the two side wall portions 41 and 42 to each other. Each of the side wall portions 41 and 42 has a shape that conforms to the inner peripheral shape of the wall portion 21 of the cylinder 20, that is, both side surfaces in the major axis direction are parallel to each other and both side surfaces in the minor axis direction are arc-shaped. Further, the outer periphery of the connecting wall portion 43 has a similar shape that is smaller than the outer peripheries of the two side wall portions 41 and 42.

[0030] Note that the surface of the first side wall portion 41 facing the second side wall portion 42 is defined as the inner surface 41a of the first side wall portion 41, and the surface of the second side wall portion 42 facing the first side wall portion 41 is defined as the inner surface 42a of the second side wall portion 42.

[0031] Also, the axial base end portion of the rod 30 is connected to the outer surface of the first side wall portion 41 (the surface on the side opposite to the surface facing the second side wall portion 42) disposed on one end side in the longitudinal direction of the piston 40, and the piston 40 and the rod 30 are integrated.

[0032] Furthermore, as shown in FIG. 10, a plurality of spaces K defined by partition walls 45 are provided inside the two side wall portions 41 and 42 and the connecting wall portion 43, and each space K is open on the second side wall portion 42 side. Referring also to FIG. 3, at a predetermined position of the first side wall portion 41, here at the one end side in the axial direction of the first side wall portion 41 and at the center position in the width direction, a small-diameter round-hole-shaped orifice 47 communicating with a predetermined space K is formed. This orifice 47 allows the first air chamber V1 and the second air chamber V2 in the cylinder 20 to communicate with each other via the space K. Note that the damping braking force is adjusted by the flow resistance of the air passing through the orifice 47.

[0033] Further, as shown in FIG. 3, on both sides of the piston 40 in the major axis direction (the major axis direction of the first side wall portion 41) sandwiching the rod 30 and on both sides in the width direction (the minor axis direction of the first side wall portion 41) sandwiching the rod 30, notch grooves 48 are formed at a predetermined depth by notching the first side wall portion 41 and the connecting wall portion 43 (a total of four notch grooves 48 are formed). When the piston 40 moves in the damper return direction F2, these notch grooves 48 form an exhaust passage for exhausting the air in the first air chamber V1 to the second air chamber V2 side (this will be described later).

[0034] And the space surrounded by the pair of side wall portions 41, 42 and the connecting wall portion 43 forms an annular groove 50. Further, the outer peripheral surface of the connecting wall portion 43 forms the bottom surface 51 of the annular groove 50. Note that the bottom surface 51 is formed to be parallel to the axial direction of the piston 40 (the direction along the axis C of the piston 40). Also, the axial width of the annular groove 50 (the length between the inner surface 41a of the first side wall portion 41 and the inner surface 42a of the second side wall portion 42) is formed to be larger than the axial length W1 of the seal ring 60 (see FIG. 5) and the axial length W2 of the friction member 70 (see FIG. 8), so that the seal ring 60 and the friction member 70 can be received in the annular groove 50.

[0035] Also, from a position near the second side wall portion 42 disposed on the damper return direction F2 side of the bottom surface 51 of the annular groove 50, a ridge 52 projecting in an annular shape continuously extending in the circumferential direction is provided. Further, in the annular groove 50, a friction member movement restricting portion for restricting the axial movement of the friction member 70 when the piston 40 moves in the damper return direction F2 is provided.

[0036] Both axial side surfaces of the above-described protrusion 52, that is, one axial side surface on the damper braking direction F1 side and the other axial side surface on the damper return direction F2 side, form inclined surfaces 54 and 55, respectively. Referring also to FIG. 11, from the top 53 that protrudes highest from the bottom surface 51 of the protrusion 52, there is a first inclined surface 54 whose height gradually decreases toward the damper braking direction F1 side, and a second inclined surface 55 whose height gradually decreases from the top 53 of the protrusion 52 toward the damper return direction F2 side. Further, the first inclined surface 54 on the damper braking direction F1 side is formed to have a shorter axial length than the second inclined surface 55 on the damper return direction F2 side.

[0037] Also, in this damper device 10, one of the bottom surface 51 of the annular groove 50 or the friction member 70 is provided with an inclined surface, and the other is provided with an inclined surface contact portion that contacts the inclined surface. In the case of this embodiment, the first inclined surface 54 of the protrusion 52 forms the "inclined surface" of the protrusion 52 in the present invention.

[0038] Furthermore, as shown in FIG. 15, when the piston 40 moves in the damper return direction F2, the second inclined surface 55 described above contacts an inclined surface 82 on the friction member side of the friction member 70 to restrict its axial movement (restrict the axial movement of the friction member 70 in the damper braking direction F1). That is, the second inclined surface 55 of the protrusion 52 forms the "friction member movement restricting portion" in the present invention.

[0039] Next, referring to FIGS. 4 and 5, the seal ring 60 will be described.

[0040] This seal ring 60 is formed of an elastic material such as rubber or elastomer and is bendable and deformable. It has a base portion 61 that forms an annular shape and is disposed in the annular groove 50, a first inner diameter side protrusion 63 and a second inner diameter side protrusion 65 that are on the inner peripheral surface of the base portion 61 and protrude from both axial end portions, and an outer diameter side protrusion 67 that is on the outer peripheral surface of the base portion 61, protrudes from the axial center position, and is press - contacted with the inner peripheral surface of the cylinder 20.

[0041] Note that a first inner-diameter-side protrusion 63 is arranged on one axial end side of the base 61, that is, on the damper braking direction F1 side, and a second inner-diameter-side protrusion 65 is arranged on the other axial end side of the base 61, that is, on the damper return direction F2 side.

[0042] The base 61 has an annular shape that conforms to the outer peripheral shape of the annular groove 50. Further, each of the protrusions 63, 65, 67 has a shape that is continuous in the circumferential direction so as to form an annular shape from the inner peripheral surface and the outer peripheral surface of the base 61 toward the radially inner or outer side of the base 61, that is, an annular protrusion that does not break in the middle of the circumferential direction of the base 61. Each of the inner-diameter-side protrusions 63, 65 has a cross-sectional shape that forms a substantially right-angled triangular mountain shape in which the inner side surfaces 63c, 65c are substantially perpendicular and the outer side surfaces 63b, 65b gradually widen from the top portions 63a, 65a at the tip of the protruding direction toward the inner peripheral surface of the base 61. On the other hand, the outer-diameter-side protrusion 67 has a cross-sectional shape that forms a substantially equilateral triangular mountain shape (which can also be said to be a shape with a widened bottom) that gradually widens from the top portion 67a at the tip of the protruding direction toward the outer peripheral surface of the base 61. Note that the top portions 63a, 65a, 67a of each of the protrusions 63, 65, 67 have a rounded shape.

[0043] Also, the axial length W1 of the seal ring 60 is formed to be smaller than the length between one axial end surface of the annular groove 50 (the inner surface 41a of the first side wall portion 41) and a pressing force receiving surface 80 (to be described later) of the friction member 70. As a result, the seal ring 60 is axially movable in the space between one axial end portion of the friction member 70 and one axial end surface of the annular groove 50 in the annular groove 50, and comes into contact with or separates from one axial end portion of the friction member 70 (see FIGS. 13 and 15).

[0044] Specifically, when the piston 40 moves in the damper return direction F2, the seal ring 60 axially moves within the annular groove 50 so as to separate from one axial end of the friction member 70 (see Fig. 15). On the other hand, when the piston 40 moves in the damper braking direction F1, the seal ring 60 is drawn in the direction approaching the friction member 70 by a suction force F3 (see Fig. 13(b)) from the first air chamber V1, and moves to the damper return direction F2 side within the annular groove 50 so as to contact one axial end of the friction member 70. As a result, the friction member 70 is pressed to expand its diameter, and its outer peripheral surface is pressed against the inner peripheral surface of the cylinder 20 (this will be described in detail in the following operation explanation).

[0045] Also, as shown in Fig. 5, before the seal ring 60 is mounted in the annular groove 50, in the free state of the seal ring 60, the radial length L1 from the tops 63a, 65a of the inner diameter side protrusions 63, 65 to the top 67a of the outer diameter side protrusion 67 is larger than the length from the inner peripheral surface of the cylinder 20 to the bottom surface 51 of the annular groove 50. As a result, when the piston 40 is inserted into the cylinder 20 with the seal ring 60 mounted in the annular groove 50, the top 67a of the outer diameter side protrusion 67 is constantly pressed against the inner peripheral surface of the cylinder 20.

[0046] Note that the above "constantly" means all states that the piston 40 can take within the cylinder 20 in the state where the piston 40 is stationary, the state at the beginning when the piston 40 starts to move in the damper braking direction F1, the state after the piston 40 has moved a predetermined distance since it started to move in the damper braking direction F1, and the state when the piston 40 moves in the damper return direction F2 (the same applies in the following explanations).

[0047] Also, in the above state, the outer diameter side protrusion 67 is pressed against the inner peripheral surface of the cylinder 20, and the seal ring 60 is bent and deformed as shown in Figs. 11, 13, and 15. Here, both side portions of the outer diameter side protrusion 67 of the base portion 61 are bent and deformed so as to slightly curve inward in the radial direction of the seal ring 60. Along with this, the inner diameter side protrusions 63, 65 are bent and deformed so as to spread toward both axial end portions of the seal ring 60.

[0048] The seal ring 60 described above has a cross-sectional shape that is line-symmetrical with respect to an axis center line S (a line that is orthogonal to the axial direction of the seal ring 60 and passes through the top 67a of the outer diameter side protrusion 67) passing through the axial center (see FIG. 5). Further, each part constituting the seal ring 60, that is, the base part 61, the inner diameter side protrusions 63 and 65, and the outer diameter side protrusion 67 are all integrally formed.

[0049] Next, with reference to FIGS. 6 to 8, the friction member 70 will be described.

[0050] This friction member 70 is formed of an elastic material such as rubber or elastomer and is bendable and deformable, has an annular shape that conforms to the outer peripheral shape of the annular groove 50, and has a base part 71 disposed in the annular groove 50.

[0051] This base part 71 has an annular shape having a major axis and a minor axis, similar to the wall part 21 of the cylinder 20 and the like, and has a pair of major axis parts 71a, 71a that linearly extend along the major axis direction and are disposed opposite to each other in parallel, and a pair of minor axis parts 71b, 71b that connect both ends of these major axis parts 71a, 71a and have an arcuately bent shape. Further, one end face 71c and the other end face 71d in the axial direction of the base part 71 are provided orthogonally to the axial direction of the friction member 70.

[0052] Furthermore, an annular void 73 into which the protrusion 52 provided in the annular groove 50 is inserted is formed over the entire circumference of the base part 71. As shown in FIG. 11, the friction member 70 is disposed on the outer circumference of the bottom face 51 of the annular groove 50 so that the protrusion 52 is inserted into this void 73, and thus the friction member 70 is mounted in the annular groove 50. In a state where the friction member 70 is mounted in the annular groove 50 in this way and the protrusion 52 is inserted into the void 73, as shown in FIG. 11, there is a gap in the void 73, and the first inclined face 54 of the protrusion 52 and an inclined face contact part 81 described later are disposed opposite to each other.

[0053] Also, on the inner periphery of the base portion 71, a first annular protrusion 75 that protrudes annularly inward in the radial direction is provided over the entire circumference of the base portion from a position on one end side in the axial direction via the gap 73. Further, on the inner periphery of the base portion 71, a second annular protrusion 77 that protrudes annularly inward in the radial direction is provided over the entire circumference of the base portion from a position on the other end side in the axial direction via the gap 73. Note that the second annular protrusion 77 has a larger amount of protrusion inward in the radial direction than the first annular protrusion 75.

[0054] Also, the tip surface 77a in the protruding direction of the second annular protrusion 77 is a surface parallel to the axial direction of the friction member 70. Further, the outer surface 77b (the side surface located on the other end side in the axial direction) of the second annular protrusion 77 is a surface orthogonal to the axial direction of the friction member 70. The outer surface 77b of the second annular protrusion 77 and the other end surface 71d of the base portion 71 form a continuous surface (flush surface) without a step, and these surfaces form a contact surface 78 that contacts the inner surface (the inner surface 42a of the second side wall portion 42) on the other end side in the axial direction of the annular groove 50. Note that this contact surface 78 is a surface orthogonal to the axial direction of the friction member 70.

[0055] Then, in a state where the ridge 52 is inserted into the gap 73 and the friction member 70 is attached to the annular groove 50, the tip surface 77a of the second annular protrusion 77 contacts the bottom surface 51 of the annular groove 50, and the contact surface 78 contacts the inner surface on the other end side in the axial direction of the annular groove 50. Also, in this state, the tip surface in the protruding direction of the first annular protrusion 75 is separated from the bottom surface 51 of the annular groove 50.

[0056] Further, the outer surface 75a (the side surface located on one end side in the axial direction) of the first annular protrusion 75 is provided orthogonally to the axial direction of the friction member 70. The outer surface 75a of the first annular protrusion 75 and the one end surface 71c of the base portion 71 form a continuous surface (flush surface) without a step, and these surfaces form a pressing force receiving surface 80 that receives the pressing force F4 (see FIG. 13) from the other end in the axial direction of the seal ring 60. Note that this pressing force receiving surface 80 is a surface orthogonal to the axial direction of the friction member 70.

[0057] When the piston 40 moves in the damper braking direction F1 on this pressing force receiving surface 80 and the sealing ring 60 is drawn in by the suction force F3 from the first air chamber V1, the other axial end of the sealing ring 60 abuts, and the pressing force F4 from the sealing ring 60 is applied.

[0058] Also, the inner surface of the first annular protrusion 75 (which can also be said to be the side surface located on the other axial end side and the surface of the gap 73 located on the one axial end side) forms an inclined surface contact portion 81 provided orthogonally to the axial direction of the friction member 70. This inclined surface contact portion 81 is arranged to face the first inclined surface 54 of the ridge 52 in a state where the friction member 70 is mounted in the annular groove 50 via the ridge 52. Further, as shown in FIG. 11, at the beginning when the piston 40 starts to move in the damper braking direction F1, the inclined surface contact portion 81 is separated from the first inclined surface 54. However, after the piston 40 starts to move in the damper braking direction F1 and moves a predetermined distance, when the sealing ring 60 is drawn in by the suction force F3 (see FIG. 13(b)) from the first air chamber V1 and the pressing force F4 from the sealing ring 60 is applied, as shown in FIG. 13, it comes into contact with the first inclined surface 54 provided on the ridge 52. Incidentally, as shown in FIG. 15, when the piston 40 moves to the damper return direction F2 side, the inclined surface contact portion 81 is also separated from the first inclined surface 54 of the ridge 52.

[0059] Also, as shown in FIG. 8, the axial length W2 of the friction member 70 is formed to be smaller than the axial width of the annular groove 50 (the length between the inner surface 41a of the first side wall portion 41 and the inner surface 42a of the second side wall portion 42) and larger than the axial length W1 of the sealing ring 60, and it is to be mounted in the annular groove 50 via the ridge 52. In this mounted state, the sealing ring 60 is arranged to be axially movable in the space formed between one axial end surface (pressing force receiving surface 80) of the friction member 70 and one axial end surface (inner surface 41a of the first side wall portion 41) of the annular groove 50.

[0060] Also, since the inclined surface contact portion 81 can be said to be the surface of the gap 73 located on the one end side in the axial direction as described above, a configuration is formed in which the gap 73 is provided in a portion adjacent to the inclined surface contact portion 81.

[0061] And when the piston 40 moves in the damper braking direction F1 and the pressing force F4 from the seal ring 60 that has moved in the damper return direction F2 due to the suction force F3 from the first air chamber V1 (see Fig. 13(b)) is applied to the pressing force receiving surface 80, the friction member 70 moves toward the damper return direction F2 side in the annular groove 50, and expands in diameter by sliding on the first inclined surface 54 of the ridge 52, and its outer peripheral surface is configured to be in pressure contact with the inner peripheral surface of the cylinder 20 (see Fig. 13).

[0062] Also, in this damper device 10, when the piston 40 moves in the damper braking direction F1, the contact position on the first inclined surface 54 changes while the inclined surface contact portion 81 is pressed against the first inclined surface 54, and the friction member 70 is configured to expand in diameter.

[0063] And the friction member 70 is configured to be smaller than the dimension of the inner peripheral surface of the cylinder 20 when the pressing force F4 from the seal ring 60 does not act.

[0064] Specifically, as shown in FIG. 15, the friction member 70 is in a state where the other axial end of the seal ring 60 is separated from the pressing force receiving surface 80 and the pressing force F4 from the seal ring 60 does not act, and the radial length L2 (see FIG. 8) from the outer peripheral surface to the tip surface 77a of the second annular protrusion 77 is smaller than the length from the inner peripheral surface of the cylinder 20 to the bottom surface 51 of the annular groove 50. As a result, as shown in FIG. 15, in a state where the pressing force F4 from the seal ring 60 does not act on the friction member 70, the outer peripheral surface of the friction member 70 is configured not to contact the inner peripheral surface of the cylinder 20. Further, FIG. 11 shows a state where the other axial end of the seal ring 60 is in contact with the pressing force receiving surface 80, but the pressing force F4 from the seal ring 60 does not act on the friction member 70. Even in the state shown in FIG. 11, the friction member 70 is smaller than the dimension of the inner peripheral surface of the cylinder 20 and is configured not to contact the inner peripheral surface of the cylinder 20.

[0065] Also, on the inner side surface of the second annular protrusion 77 (which can also be said to be the side surface located on the one axial end side and the surface of the gap 73 located on the other axial end side), a friction member inclined surface 82 is formed. This friction member inclined surface 82 is a surface inclined so as to gradually deepen obliquely inward from one axial end of the tip surface 77a in the protruding direction of the second annular protrusion 77 toward the bottom surface 73a of the gap 73. Further, this friction member inclined surface 82 is an inclined surface that conforms to the second inclined surface 55 of the protrusion 52. Then, as shown in FIG. 11 and the like, in a state where the protrusion 52 is inserted into the gap 73 and the friction member 70 is mounted in the annular groove 50, the friction member inclined surface 82 is in contact (closely contacts) with the second inclined surface 55 of the protrusion 52 without a gap.

[0066] Further, on the outer peripheral surface of the end portion of the friction member 70 located on the damper return direction F2 side, a tapered surface 83 that tapers toward the damper return direction F2 is formed. In this embodiment, on the outer peripheral surface of the axially other end portion of the base portion 71 located on the damper return direction F2 side, a tapered surface 83 is formed that is inclined so as to gradually decrease in diameter toward the damper return direction F2. As shown in FIG. 8, this tapered surface 83 is inclined so as to be substantially parallel to the friction member side inclined surface 82 formed on the second annular protrusion 77.

[0067] Further, vent grooves 85 extending along the axial direction are formed on the outer peripheral surface of the friction member 70. In this embodiment, on the outer peripheral surfaces of the pair of long axis portions 71a, 71a of the base portion 71, vent grooves 85 are respectively extended along the axial direction of the friction member 70 at the longitudinal center of each long axis portion 71a. Each vent groove 85 is formed with a constant width and a constant depth from one end surface 71c in the axial direction of the base portion 71 to the middle of the inclined surface of the tapered surface 83.

[0068] Each vent groove 85 is configured to maintain its air permeability even when the piston 40 moves in the damper braking direction F1 and the outer peripheral surface of the friction member 70 is pressed against the inner peripheral surface of the cylinder 20 by being pressed by the seal ring 60.

[0069] That is, as shown in FIG. 13(b), even when the piston 40 moves in the damper braking direction F1 and the outer peripheral surface of the friction member 70 to which the pressing force F4 from the seal ring 60 that has moved in the damper return direction F2 due to the suction force F3 from the first air chamber V1 is applied is pressed against the inner peripheral surface of the cylinder 20, the vent groove 85 is not crushed, is not pressed against the inner peripheral surface of the cylinder 20, and its internal space is secured to maintain air permeability.

[0070] Next, the operations of the seal ring 60 and the friction member 70 in the annular groove 50 when the piston 40 moves in the damper braking direction F1 and when it moves in the damper return direction F2 will be described.

[0071] When the piston 40 is stationary, basically, it is in the same state as when the piston 40 has moved in the damper return direction F2 (see FIGS. 14 and 15).

[0072] That is, in the seal ring 60, the top 67a of the outer diameter side protrusion 67 is in pressure contact with the inner peripheral surface of the cylinder 20, the tops 63a, 65a of the inner diameter side protrusions 63, 65 are in contact with the bottom surface 51 of the annular groove 50, and the other end in the axial direction is separated from the pressure receiving surface 80 of the friction member 70, and a gap G (see FIG. 15) is formed. This gap G communicates with the internal space R of the annular groove 50 and the notch groove 48 provided in the piston 40 (see FIG. 15(c)). Therefore, the first air chamber V1 and the second air chamber V2 are in a state of communicating with each other via the gap G, the internal space R, and the notch groove 48. Further, the seal ring 60 is arranged in the cylinder 20 in a deformed state from the seal ring free state shown in FIG. 5.

[0073] On the other hand, in the friction member 70, its contact surface 78 is in contact with the inner surface on the other end side in the axial direction of the annular groove 50 (the inner surface 42a of the second side wall portion 42), and the tip surface 77a of the second annular protrusion 77 is in contact with the bottom surface 51 of the annular groove 50. In this state, since the pressing force F4 from the seal ring 60 does not act on the friction member 70, the friction member 70 is not expanded in diameter, and its outer peripheral surface is not in contact with and is separated from the inner peripheral surface of the cylinder 20.

[0074] Then, as shown in FIG. 10, when the piston 40 starts to move in the damper braking direction F1, a frictional force (frictional force in the damper return direction F2) in the direction opposite to the damper braking direction F1 acts on the outer diameter side protrusion 67 from the inner peripheral surface of the cylinder 20. Due to this frictional force, the seal ring 60 is pushed toward the damper return direction F2. As a result, as shown in FIG. 11, the other end in the axial direction of the seal ring 60 abuts on the pressing force receiving surface 80 of the friction member 70. Then, as shown in FIG. 11(c), the gap G (see FIG. 15) between the other end in the axial direction of the seal ring 60 and the pressing force receiving surface 80 of the friction member 70 disappears, and the air flow between the first air chamber V1 and the second air chamber V2 through the gap G, the internal space R of the annular groove 50, and the notch groove 48 is inhibited. Therefore, the first air chamber V1 in the cylinder 20 is depressurized, and the damper braking force is exerted.

[0075] Thereafter, as shown in FIG. 12, when the piston 40 moves a predetermined distance in the damper braking direction F1, the seal ring 60 is further pushed toward the damper return direction F2 by the frictional force in the damper return direction F2 from the inner peripheral surface of the cylinder 20. At the same time, due to the movement of the piston 40 toward the damper braking direction F1 side, the first air chamber V1 is further depressurized compared to the state shown in FIG. 10. That is, along with the pressure change (depressurization in this embodiment) of the first air chamber V1, an attracting force F3 (see FIG. 13(b)) from the first air chamber V1 acts on the seal ring 60, and the seal ring 60 further moves so as to be drawn toward the damper return direction F2 side. The attracting force F3 from the first air chamber V1 is applied to the seal ring 60 when the air in the first air chamber V1 flows through the internal space R of the annular groove 50 and the pair of ventilation grooves 85, 85 provided in the friction member 70.

[0076] As a result, as shown in FIG. 13, the axially other end of the seal ring 60 presses the pressing force receiving surface 80 of the friction member 70, and a pressing force F4 is applied to the inclined surface contact portion 81. Then, while the inclined surface contact portion 81 presses the first inclined surface 54 of the protrusion 52, it slides on the first inclined surface 54 (moves so as to ride up and slide on the first inclined surface 54), and the contact position on the first inclined surface 54 gradually changes. By doing so, the first inclined surface 54 converts the moving direction of the seal ring 60 along the axial direction of the piston 40 (the moving direction toward the damper return direction F2) into the direction toward the radially outer side of the piston 40. As a result, as shown in FIG. 13, the friction member 70 is expanded in diameter, and its outer peripheral surface is pressed against the inner peripheral surface of the cylinder 20 as shown by the arrow F5 (the force directed toward the arrow F5 at this time, that is, the pressing force of the friction member 70 against the inner peripheral surface of the cylinder 20 is also referred to as "pressing force F5"). In this way, due to the suction force F3 from the first air chamber V1 accompanying the pressure change in the first air chamber V1, when the seal ring 60 moves toward the damper return direction F2, the friction member 70 is pressed, and its outer peripheral surface is pressed against the inner peripheral surface of the cylinder 20, so that a frictional force of the friction member 70 is generated with respect to the inner peripheral surface of the cylinder 20.

[0077] As described above, in this damper device 10, when the piston 40 moves in the damper braking direction F1, due to the pressure change in the air chamber and the frictional force of the seal ring 60 against the inner peripheral surface of the cylinder 20, the friction member 70 is pressed by the seal ring 60, so that a frictional force of the friction member 70 is generated with respect to the inner peripheral surface of the cylinder 20. At this time, a high damper braking force composed of the resistance due to the pressure change in the first air chamber V1, the frictional force of the seal ring 60 against the inner peripheral surface of the cylinder 20, and the frictional force of the friction member 70 against the inner peripheral surface of the cylinder 20 is exerted. That is, in this damper device 10, a damper braking force composed of the resistance due to the pressure change in the first air chamber V1, the frictional force of the seal ring 60 against the inner peripheral surface of the cylinder 20, and the frictional force of the friction member 70 against the inner peripheral surface of the cylinder 20 is exerted.

[0078] On the one hand, as shown in FIG. 14, when the piston 40 moves in the damper return direction F2, a frictional force opposite to the damper return direction F2 acts on the outer diameter side protrusion 67 of the seal ring 60 from the inner peripheral surface of the cylinder 20. Due to this frictional force, the seal ring 60 is pushed toward the damper braking direction F1 side. As a result, as shown in FIG. 15, one axial end portion of the seal ring 60 abuts against the inner surface (inner surface 41a of the first side wall portion 41) on the one axial end side of the annular groove 50, and the other axial end portion of the seal ring 60 separates from the pressing force receiving surface 80 of the friction member 70. Then, the friction member 70 elastically returns to its original shape, and the pressing contact force F5 no longer acts on the inner peripheral surface of the cylinder 20. At the same time, a gap G is generated again between the other axial end portion of the seal ring 60 and the pressing force receiving surface 80 of the friction member 70. As a result, as shown by the arrow in FIG. 15(c), the air in the first air chamber V1 in the cylinder 20 sequentially passes through the internal space R of the annular groove 50, the pair of ventilation grooves 85, 85 of the friction member 70, the gap G, and the plurality of notch grooves 48 and flows out to the second air chamber V2. As a result, the damper braking force is released.

[0079] (Modification example) The shapes and structures of the cylinder, rod, piston, seal ring, etc. that constitute the damper device in the present invention are not limited to the above embodiments.

[0080] The wall portion 21 of the cylinder 20 in this embodiment has a substantially thin box-shaped cylindrical shape. However, as the wall portion of the cylinder, for example, it may be substantially square cylindrical or substantially cylindrical. In this case, the rod, piston, seal ring, seal cap, anti-disengagement cap, etc. are also preferably formed in shapes corresponding to the wall portion of the cylinder.

[0081] Further, although the end wall 25 is arranged and closed on the other end side in the axial direction of the cylinder 20 in this embodiment, for example, a through hole may be formed in the end wall arranged at the other end of the cylinder, and this through hole may be opened and closed by a seal cap.

[0082] Furthermore, although the rod 30 of this embodiment has a prismatic shaft portion 31, the rod may have, for example, a structure including a shaft portion and a pair of side walls disposed on both sides thereof via a plurality of members, or a structure including a shaft portion having a long plate shape, a cylindrical shape, or the like, as long as the pistons can be connected in series.

[0083] Also, in the piston 40 of this embodiment, the bottom surface 51 of the annular groove 50 is parallel to the axial direction of the piston 40. However, as the annular groove, for example, the bottom surface may be inclined or stepped.

[0084] Furthermore, in the seal ring 60 of this embodiment, the inner diameter side protrusions 63 and 65 protrude from both axial ends of the inner peripheral surface. However, the number of the inner diameter side protrusions may be three or more, and they may be arranged axially inside both axial ends of the inner peripheral surface. Also, although the outer diameter side protrusion 67 is arranged at the axial center of the seal ring 60, it may be displaced. However, it is preferable that the top of the outer diameter side protrusion is provided at a position displaced axially without overlapping the top of the inner diameter side protrusion.

[0085] Furthermore, in this embodiment, a seal portion is formed between the cylinder 20 and the piston 40 by the seal ring 60 and the friction member 70. However, a seal portion may be formed between the cylinder and the piston by the seal ring.

[0086] For example, the sealing ring is an O-ring with a circular cross-section, which is movably mounted in an annular groove on the outer periphery of the piston, and the outer peripheral surface of the sealing ring is pressed against the inner peripheral surface of the cylinder, and the inner peripheral surface of the sealing ring is pressed against the bottom surface of the annular groove. Thereby, a "sealing portion" for sealing the gap between the cylinder and the piston is formed by the sealing ring which is an O-ring. In this case, the friction member may be brought into contact with the other end surface in the axial direction of the annular groove, or may not be brought into contact. Further, the bottom surface of the annular groove is not provided with the notch groove 48 or the like in the above embodiment. Instead, an exhaust hole communicating with the air chamber is formed at a predetermined position of the cylinder, and a sealing cap capable of opening and closing the exhaust hole is mounted on the periphery of the exhaust hole. When the piston moves in the damper return direction, the sealing cap opens the exhaust hole, so that the air in the air chamber is exhausted and the damper braking force is released.

[0087] In addition, the friction member 70 of this embodiment has a structure in which a first annular protrusion 75 and a second annular protrusion 77 are provided on its inner periphery via a gap 73, and the number of annular protrusions may be one or three or more.

[0088] Furthermore, one end surface 71c and the other end surface 71d in the axial direction of the base portion 71 are flush with the outer side surface 75a of the first annular protrusion 75 and the outer side surface 77b of the second annular protrusion 77, but there may be a step. Also, the contact surface 78 and the pressing force receiving surface 80 are surfaces orthogonal to the axial direction of the friction member 70, but may be inclined at a predetermined angle other than 90° with respect to the axial direction of the friction member.

[0089] Furthermore, in the case of this embodiment, the sealing ring 60 sucked by the suction force F3 from the first air chamber V1 applies a pressing force F4 to the friction member 70, so that the inclined surface contact portion 81 of the friction member 70 slides on the first inclined surface 54 of the protrusion 52 provided in the annular groove 50, and the friction member 70 is configured to expand in diameter. However, the diameter expansion structure of the friction member by the sealing ring is not limited to this aspect.

[0090] A modification example thereof is described in FIG. 16.

[0091] That is, an annular concave groove 56 is formed on the bottom surface 51 of the annular groove 50. An inclined surface 57 is formed on the inner surface of this concave groove 56 on the side of the damper return direction F2. This inclined surface 57 is an inclined surface that protrudes so as to gradually become higher from the bottom surface 56a of the concave groove 56 toward the damper return direction F2. Further, the first annular protrusion 75A of the friction member 70 has a larger amount of protrusion radially inward than the second annular protrusion 77. The tip of the first annular protrusion 75A in the protruding direction enters the concave groove 56, and the inclined surface contact portion 81 provided on the inner surface of the first annular convex portion 75A is disposed to face the inclined surface 57 of the concave groove 56.

[0092] On the inner surface of the concave groove 56 on the side of the damper braking direction F1, a facing surface 56b is provided that is orthogonal to the axial direction of the piston 40 and is disposed to face the inclined surface 57. When the piston 40 moves in the damper return direction F2, this facing surface 56b abuts against the pressing force receiving surface 80 of the friction member 70 to restrict the axial movement of the friction member 70, and forms the "friction member movement restricting portion" in the present invention.

[0093] When the seal ring 60 is attracted by the suction force F3 from the first air chamber V1 and the seal ring 60 applies a pressing force F4 to the friction member 70, the inclined surface contact portion 81 slides on the inclined surface 57, so that the friction member 70 expands in diameter.

[0094] Furthermore, in this embodiment, when the piston 40 moves in a direction away from the end wall 25 of the cylinder 20 (when the piston 40 moves in the damper braking direction F1), a braking force due to the decompression of the first air chamber V1 acts, and when the piston 40 moves in a direction approaching the end wall 25 of the cylinder 20 (when the piston 40 moves in the damper return direction F2), the braking force is configured to be released. However, conversely, it may be configured such that when the piston 40 moves in a direction approaching the end wall 25 of the cylinder 20, a damper braking force acts, and when the piston 40 moves in a direction away from the end wall 25 of the cylinder 20, the damper braking force is released (this will be described in another embodiment to be described later).

[0095] Also, in this embodiment, when the piston 40 moves in the damper return direction F2, a gap G is generated between the axially other end of the seal ring 60 and the pressing force receiving surface 80 of the friction member 70, and as shown by the arrow in FIG. 15(c), the air in the first air chamber V1 in the cylinder 20 flows out to the second air chamber V2. However, when the piston 40 moves in the damper return direction F2, the axially other end surface (contact surface 78) of the friction member 70 is separated from the inner surface (inner surface 42a of the second side wall portion 42) on the axially other end side of the annular groove 50, so that the seal between the contact surface 78 of the friction member 70 and the inner surface 42a of the annular groove 50 is released, and the gap between the contact surface 78 of the friction member 70 and the inner surface 42a of the annular groove 50 may be used as an air flow passage. In this case, as shown by the broken-line arrow in FIG. 15(c), the air in the first air chamber V1 in the cylinder 20 sequentially passes through the internal space R of the annular groove 50, the above gap, and several notch grooves 48 and flows out to the second air chamber V2.

[0096] In this embodiment, the sealing ring 60 is configured to move toward the damper return direction F2 by the suction force F3 from the first air chamber V1. However, for example, the sealing ring may be moved in the damper return direction by the pressure from the first air chamber (this will be described in other embodiments), and it is sufficient that the sealing ring can be moved in the damper return direction in accordance with the pressure change in the air chamber.

[0097] In this embodiment, one member is a fixed body such as the accommodation part of the instrument panel, and the other member is an opening / closing body such as the glove box and the lid. However, the pair of members is not particularly limited as long as they can approach and separate from each other.

[0098] In this embodiment, an air chamber (first air chamber V1) is formed in the cylinder 20 on the insertion direction side of the rod 30 from the seal part. However, an air chamber may be provided on the side opposite to the rod insertion direction in the cylinder. For example, an exhaust hole is formed in the end wall of the cylinder, and a seal cap that can open and close the exhaust hole is attached to the periphery of the exhaust hole. Further, the cap attached to the opening at one end of the cylinder has a structure capable of sealing the periphery of the opening and a structure capable of sealing the gap between the rod insertion hole and the rod inserted through the rod insertion hole, so as to provide a sealed air chamber on the side opposite to the rod insertion direction in the cylinder. Then, when the piston moves in the direction away from the end wall of the cylinder (moves in the direction opposite to the rod insertion direction), the air chamber is pressurized, and the damper braking force is exerted. When the piston moves close to the end wall of the cylinder (moves toward the rod insertion direction side), the seal cap opens the exhaust hole, the air in the air chamber is exhausted, and the damper braking force is released.

[0099] (Function and Effect) Next, the function and effect of the damper device 10 having the above configuration will be described.

[0100] In this damper device 10, when the other member (such as an opening / closing body) approaches the one member (such as a fixed body), the piston 40 is in a stationary state within the cylinder 20. In this state, the top 67a of the outer diameter side protrusion 67 abuts against the inner peripheral surface of the cylinder 20, and the tops 63a, 65a of the inner diameter side protrusions 63, 65 abut against the bottom surface 51 of the annular groove 50, and the seal ring 60 is disposed within the annular groove 50.

[0101] When the other member moves in a direction away from the one member from the above state (when the opening / closing body opens from the fixed body), that is, as shown in FIG. 10, when the piston 40 starts to move in the damper braking direction F1, the piston 40 moves within the cylinder 20 in the damper braking direction F1, and the rod 30 is pulled out from the opening 23 side of the cylinder 20. Then, as described in the above paragraph 0074, since the first air chamber V1 within the cylinder 20 is depressurized, a damper braking force is applied to the piston 40.

[0102] Thereafter, as shown in FIG. 12, when the piston 40 moves a predetermined distance in the damper braking direction F1, the seal ring 60 moves toward the damper return direction F2 along with the pressure change (depressurization in this embodiment) of the air chamber. Then, as described in the above paragraphs 0075 to 0077, the suction force F3 from the first air chamber V1 acts on the seal ring 60, causing the seal ring 60 to move toward the damper return direction F2. As a result, as shown in FIG. 13, the seal ring 60 applies a pressing force F4 to the friction member 70, expanding the diameter of the friction member 70, so that its outer peripheral surface is pressed against the inner peripheral surface of the cylinder 20 with a predetermined pressing contact force F5.

[0103] Thus, in this damper device 10, when the piston 40 moves in the damper braking direction F1, due to the pressure change in the first air chamber V1 and the frictional force of the seal ring 60 against the inner peripheral surface of the cylinder 20, the friction member 70 is pressed against the seal ring 60, and the friction member can be sufficiently deformed. As a result, the outer peripheral surface of the friction member 70 can be brought into pressure contact with the inner peripheral surface of the cylinder 20. Consequently, in addition to the frictional force of the seal ring 60 against the inner peripheral surface of the cylinder 20, a frictional force of the friction member 70 against the inner peripheral surface of the cylinder 20 can be generated. In this way, a high damper braking force composed of the resistance due to the pressure change in the first air chamber V1, the frictional force of the seal ring 60 against the inner peripheral surface of the cylinder 20, and the frictional force of the friction member 70 against the inner peripheral surface of the cylinder 20 can be obtained, so that one member can be slowly moved relative to the other member (the opening / closing body can be slowly opened from the fixed body).

[0104] Note that the friction member 70 constituting this damper device 10 is configured to be smaller than the dimension of the inner peripheral surface of the cylinder 20 when the pressing force F4 from the seal ring 60 does not act. Therefore, the following effects (1) to (3) can be obtained.

[0105] (1) During damper braking, the friction member 70 can be easily expanded in diameter and can be easily brought into pressure contact with the inner peripheral surface of the cylinder 20. (If the friction member 70 is larger than the dimension of the inner peripheral surface of the cylinder 20, there is no or little room for the friction member 70 to expand in diameter, and it is difficult to expand in diameter when pressed by the seal ring 60).

[0106] (2) When the damper braking force is released (when the piston 40 moves in the damper return direction F2), a wide air flow path can be ensured, and the air in the first air chamber V1 can be quickly exhausted to the second air chamber V2 side. Therefore, the return resistance of the piston 40 can be reduced, and the operating force of the piston 40 can be lowered.

[0107] (3) When the damper braking force is released, since the frictional force of the friction member 70 does not occur with respect to the inner peripheral surface of the cylinder 20, the return resistance of the piston 40 can be reduced, and the operating force of the piston 40 can be reduced.

[0108] Further, in this embodiment, as shown in FIGS. 11 and 13, a slope is provided on one of the bottom surface 51 of the annular groove 50 or the friction member 70 (here, the first slope 54 provided on the ridge 52 of the annular groove 50), and on the other side, a slope contact portion that contacts the slope is provided (here, the slope contact portion 81 provided on the friction member 70). When the piston 40 moves in the damper braking direction F1, the contact position on the first slope 54 changes while the slope contact portion 81 is pressed against the first slope 54, and the friction member 70 is configured to expand in diameter.

[0109] According to the above aspect, when the friction member 70 receives the pressing force F4 from the seal ring 60 during damper braking, the friction member 70 can be more easily expanded in the radially outward direction. As a result, the frictional force of the friction member 70 against the inner peripheral surface of the cylinder 20 can be increased, and a higher damper braking force can be obtained.

[0110] Further, in this embodiment, as shown in FIGS. 11 and 13, a ridge 52 extending in the circumferential direction is provided on the bottom surface 51 of the annular groove 50, and the surface of the ridge 52 on the damper braking direction F1 side forms a slope (the first slope 54), and a gap 73 is provided in a portion adjacent to the slope contact portion 81 of the friction member 70.

[0111] According to the above aspect, due to the gap 73 provided in the portion adjacent to the slope contact portion 81 of the friction member 70, when the friction member 70 receives the pressing force from the seal ring 60 during damper braking, the friction member 70 can be made more easily expand in diameter, and a higher damper braking force can be obtained. Further, by using the protrusion 52 provided on the bottom surface 51 of the annular groove 50 and the gap 73 provided in the friction member 70, the friction member 70 can be easily mounted in the annular groove 50. That is, when attempting to externally mount the friction member 70 in the annular groove 50 while expanding its diameter, by arranging the friction member 70 in the annular groove 50 such that the protrusion 52 is inserted into the gap 73, the gap 73 catches on the protrusion 52, making it difficult for the friction member 70 to be displaced, so that the friction member 70 can be easily mounted in the annular groove 50.

[0112] Also, in this embodiment, as shown in FIGS. 6 to 8, vent grooves 85 extending along the axial direction are formed on the outer peripheral surface of the friction member 70. The vent grooves 85 are configured such that when the piston 40 moves in the damper braking direction F1, even when the outer peripheral surface of the friction member 70 is pressed against the inner peripheral surface of the cylinder 20 under the pressure of the seal ring 60, its air permeability is maintained (see FIG. 13(b)).

[0113] According to the above aspect, even when the friction member 70 expands in diameter during damper braking and its outer peripheral surface is pressed against the inner peripheral surface of the cylinder 20, the air permeability of the vent grooves 85 is maintained. Thus, an air passage communicating with the first air chamber V1 (which also communicates with the internal space R of the annular groove 50 here) can be ensured, and the suction force F3 from the first air chamber V1 can be reliably applied to the seal ring 60.

[0114] Also, when one member is moved in a direction approaching the other member (when closing the opening / closing body with respect to the fixed body), as shown in FIG. 14, the piston 40 moves in the damper return direction F2 within the cylinder 20, and at the same time, the rod 30 is pushed into the cylinder 20.

[0115] Then, on the outer diameter side protrusion 67, a frictional force opposite to the damper return direction F2 acts from the inner peripheral surface of the cylinder 20. Due to this frictional force, the seal ring 60 is pushed toward the damper braking direction F1. As described in the above paragraph 0078, as shown by the arrow in FIG. 15(c), the air in the first air chamber V1 in the cylinder 20 sequentially passes through the internal space R of the annular groove 50, the pair of ventilation grooves 85, 85 of the friction member 70, the gap G, and the plurality of notch grooves 48, and flows out to the second air chamber V2, and the damper braking force is released.

[0116] At this time, in this embodiment, the friction member 70 is formed with a tapered surface 83 that reduces in diameter toward the damper return direction F2 on the outer peripheral surface of the end portion located on the damper return direction F2 side.

[0117] According to the above aspect, when the piston 40 moves in the damper return direction F2, the friction member 70 can be prevented from being caught by the inner peripheral surface of the cylinder 20, and the operating force of the piston 40 can be reduced.

[0118] Also, in this embodiment, the annular groove 50 is provided with a friction member movement restricting portion (here, the second inclined surface 55 of the protrusion 52) that restricts the axial movement of the friction member 70 when the piston 40 moves in the damper return direction F2.

[0119] According to the above aspect, when the piston 40 moves in the damper return direction F2, the friction member side inclined surface 82 of the friction member 70 abuts against the second inclined surface 55 of the protrusion 52 that forms the friction member movement restricting portion, and the axial movement (movement toward the damper braking direction F1) of the friction member 70 is restricted. Therefore, when the piston 40 moves in the damper return direction F2, the seal ring 60 and the friction member 70 can be easily separated. As a result, the diameter of the friction member 70 can be quickly reduced, the operating force of the piston 40 can be reduced, and a ventilation path (gap G: see FIG. 15) can be formed between the seal ring 60 and the friction member 70.

[0120] (Other embodiments of the damper) Figures 17 and 18 show other embodiments of the damper device according to the present invention. In addition, the same reference numerals are given to substantially the same parts as those in the above embodiment, and the description thereof is omitted.

[0121] Contrary to the damper device 10 shown in FIGS. 1 to 16, in the damper device 10A of this embodiment, when the piston 40 moves in a direction approaching the end wall 25 of the cylinder 20, a braking force acts, and when the piston 40 moves in a direction away from the end wall 25 of the cylinder 20, the braking force is released.

[0122] That is, in the case of this embodiment, the arrangement of the seal ring 60 and the friction member 70 with respect to the annular groove 50 is opposite to the arrangement of the seal ring 60 and the friction member 70 in the damper device 10 shown in FIGS. 1 to 16.

[0123] Specifically, as shown in FIG. 18, a protrusion 52 is provided on the bottom surface 51 of the annular groove 50 at a position near the first side wall portion 41. The side surface of the protrusion 52 facing the second side wall portion 42 forms a first inclined surface 54, and the inclined surface facing the first side wall portion 41 forms a second inclined surface 55. Further, the friction member 70 is mounted in the annular groove 50 via the protrusion 52 such that the pressing force receiving surface 80 faces the second side wall portion 42. Furthermore, the seal ring 60 is arranged axially movably in the annular groove 50 with one end in the axial direction facing the friction member 70 side and the other end in the axial direction facing the second side wall portion 42 side, and one end in the axial direction of the seal ring 60 presses the pressing force receiving surface 80 of the friction member 70.

[0124] When the piston 40 starts to move in the damper braking direction F1 and moves a predetermined distance, due to the frictional force in the damper return direction F2 from the inner peripheral surface of the cylinder 20, the seal ring 60 is pushed toward the damper return direction F2 side. Along with the pressure change (pressurization) in the first air chamber V1, the pressing force F3' from the first air chamber V1 acts on the seal ring 60, causing the seal ring 60 to move toward the damper return direction F2 side. As a result, the friction member 70 is pressed and expands in diameter, and its outer peripheral surface is pressed against the inner peripheral surface of the cylinder 20 with a predetermined pressing contact force. Therefore, the frictional force of the friction member 70 against the inner peripheral surface of the cylinder 20 can be generated, and a high damper braking force can be obtained.

[0125] Moreover, the present invention is not limited to the above-described embodiments, and various modified embodiments are possible within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention.

Explanation of Reference Numerals

[0126] 10, 10A Damper device 20 Cylinder 30 Rod 40 Piston 50 Annular groove 51 Bottom surface 52 Ridge 54 First inclined surface (inclined surface) 60 Seal ring 70 Friction member 73 Gap 75 First annular protrusion 77 Second annular protrusion 78 Contact surface 80 Pressing force receiving surface 81 Inclined surface contact portion 83 Tapered surface 85 Vent groove 90 Prevention cap

Claims

1. A damper device attached between a pair of members that approach and separate from each other, and that applies a braking force when the pair of members approach or separate, comprising: a cylinder having an opening at one end; a rod movably inserted into the cylinder through the opening; a piston connected to the rod and having an annular groove formed on its outer periphery; a seal ring disposed axially movably on the damper braking direction side of the annular groove and pressed against the inner peripheral surface of the cylinder; in the annular groove, a friction member disposed on the return direction side opposite to the damper braking direction with respect to the seal ring; a seal portion is formed between the cylinder and the piston by the seal ring and the friction member, or by the seal ring; an air chamber is formed in the cylinder via the seal portion; when the piston moves in the damper braking direction, the seal ring presses the friction member to expand its diameter, and the outer peripheral surface of the friction member is pressed against the inner peripheral surface of the cylinder; the friction member is configured to be smaller than the dimension of the inner peripheral surface of the cylinder when the pressing force from the seal ring does not act; a slope is provided on one of the bottom surface of the annular groove or the friction member, and a slope contact portion that contacts the slope is provided on the other; A damper device, characterized in that when the piston moves in the damper braking direction, the contact position on the slope changes while the slope contact portion is pressed against the slope, so that the friction member expands its diameter.

2. A damper device attached between a pair of members that approach and separate from each other, and that applies a braking force when the pair of members approach or separate, comprising: a cylinder having an opening at one end; a rod movably inserted into the cylinder through the opening; a piston connected to the rod and having an annular groove formed on its outer periphery; a seal ring disposed axially movably on the damper braking direction side of the annular groove and pressed against the inner peripheral surface of the cylinder; in the annular groove, a friction member disposed on the return direction side opposite to the damper braking direction with respect to the seal ring; a seal portion is formed between the cylinder and the piston by the seal ring and the friction member, or by the seal ring; An air chamber is formed in the cylinder via the seal portion. When the piston moves in the damper braking direction, the seal ring presses the friction member to expand its diameter, and the outer peripheral surface of the friction member is brought into pressure contact with the inner peripheral surface of the cylinder. The friction member is configured to be smaller than the dimension of the inner peripheral surface of the cylinder when the pressing force from the seal ring does not act. The damper device is characterized in that the seal ring has an annular base portion disposed in the annular groove, at least two inner diameter side protrusions protruding from the inner diameter side surface of the base portion, and an outer diameter side protrusion protruding from the outer diameter side surface of the base portion and contacting the inner peripheral surface of the cylinder.

3. The damper device according to claim 1 or 2, wherein the friction member has a tapered surface that tapers toward the return direction side formed on the outer peripheral surface of the end portion located on the return direction side.

4. The damper device according to claim 1 or 2, wherein the annular groove is provided with a friction member movement restricting portion that restricts the axial movement of the friction member when the piston moves in the return direction.

5. A ridge extending in the circumferential direction is provided on the bottom surface of the annular groove. The surface of the ridge on the damper braking direction side forms the inclined surface. The damper device according to claim 1, wherein a gap is provided in a portion adjacent to the inclined surface contact portion of the friction member.

6. A ventilation groove extending along the axial direction is formed on the outer peripheral surface of the friction member. The ventilation groove is configured to maintain its air permeability even when the piston moves in the damper braking direction and the outer peripheral surface of the friction member is brought into pressure contact with the inner peripheral surface of the cylinder under the pressure of the seal ring, as described in claim 1 or 2.

7. Among the inner diameter side protrusions, the outer surface of the inner diameter side protrusion located on the return direction side, which is the most opposite to the damper braking direction, and the entire area from the inner diameter side surface of the base portion to the top of the inner diameter side protrusion is inclined toward the other inner diameter side protrusion adjacent in the axial direction as it separates from the inner diameter side surface of the base portion. The damper device according to claim 2.

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