Damper Device

Abstract

Provided is a damper device that makes it possible to reduce piston operation force when a piston moves in a return direction opposite to a damper braking direction. This damper device 10 includes a cylinder 20, a rod 30, a piston 40 provided with an annular groove 45, and a seal ring 50. The seal ring 50 includes a base 51, two inner diameter-side protrusions 53, 55, and an outer diameter-side protrusion 57. At least one of the inner diameter-side protrusions 53, 55 is in contact with the bottom surface 45a of the annular groove 45. The outer diameter-side protrusion 57 is a surface on the outer diameter side of the base 51 and protrudes in an annular shape so that a top section 57a of the outer diameter-side protrusion 57 is arranged at a position corresponding to the interval between the top sections 53a, 55a of the axially adjacent inner diameter-side protrusions 53, 55.

Description

[Technical Field]

[0001] The present invention relates to a damper device used, for example, to brake the opening and closing of a glove compartment in an automobile. [Background technology]

[0002] For example, a damper device is sometimes used in a glove compartment of an automobile to prevent the lid from opening suddenly and to allow the lid to open gradually.

[0003] As such a damper device, Patent Document 1 listed below describes an air damper assembly having a housing, a piston rod that slides within the housing, a piston head provided at the front end of the piston rod, and a lip seal attached to an annular groove formed on the outer periphery of the piston head.

[0004] The lip seal has a generally U-shaped cross section and is made up of a base, an inner lip that projects from the inner edge of one axial end of the base and abuts the bottom of the annular groove, and an outer lip that projects from the outer edge of one axial end of the base and abuts the inner circumferential surface of the housing. The outer lip projects diagonally outward relative to the inner lip, and normally the tip of the outer surface of the outer lip partially abuts against the inner circumferential surface of the housing. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-277873 Summary of the Invention [Problem to be solved by the invention]

[0006] In the air damper assembly of Patent Document 1, when the piston head moves in the return direction opposite to the damper braking direction, the piston rod may tilt relative to the axis of the housing. In this case, the piston head also tilts following the tilt of the piston rod, causing the outer surface of the outer lip of the lip seal attached to the annular groove to come into contact with a wide area of ​​the inner circumferential surface of the housing. As a result, the frictional resistance of the lip seal against the inner circumferential surface of the housing increases, which can increase the operating force of the piston head.

[0007] SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a damper device that can reduce the operating force of the piston when the piston moves in the return direction opposite to the damper braking direction. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides a damper device that is attached between a pair of members that move toward or away from each other and that applies a braking force when the pair of members move toward or away from each other, the damper device comprising: a cylinder with an opening at one end; a rod that is movably inserted into the cylinder through the opening; a piston that is connected to the rod and has an annular groove formed on its outer periphery; and a seal ring that is attached to the annular groove and is pressed against the inner circumferential surface of the cylinder, the seal ring having an annular base that is disposed within the annular groove, at least two inner diameter side protrusions that protrude from the inner diameter side surface of the base, and an outer diameter side protrusion that protrudes from the outer diameter side surface of the base and abuts against the inner circumferential surface of the cylinder, at least one of the inner diameter side protrusions abuts against the bottom surface of the annular groove, and the outer diameter side protrusion protrudes annularly so that the apex of the outer diameter side protrusion is positioned on the outer diameter side surface of the base at a position that corresponds to the space between the apexes of the inner diameter side protrusions that are adjacent in the axial direction. [Effects of the Invention]

[0009] In the present invention, the outer diameter side protrusion protrudes annularly on the outer diameter side surface of the base so that the top of the outer diameter side protrusion is positioned at a position corresponding to the space between the tops of the inner diameter side protrusions adjacent to each other in the axial direction. This makes it easier for the seal ring to flex and deform, suppressing the reaction force from the seal ring against the inner surface of the cylinder and reducing the operating force of the piston when it moves in the damper return direction. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is an exploded perspective view showing an embodiment of a damper device according to the present invention. [Figure 2] FIG. [Figure 3] FIG. 2 is an enlarged perspective view of a piston that constitutes the damper device. [Figure 4] FIG. 2 is an enlarged perspective view of a seal ring that constitutes the damper device. [Figure 5] FIG. 5 is a cross-sectional view taken along the line BB in FIG. 4. [Figure 6] 3 is a cross-sectional view taken along the line AA in FIG. 2, showing a state in which the rod has been pulled out by a predetermined length. [Figure 7] 10 is an enlarged cross-sectional view illustrating a main part of the damper device when the piston moves in the damper braking direction. FIG. [Figure 8] 10 is an enlarged cross-sectional view illustrating a main part of the damper device when the piston moves in a return direction opposite to the damper braking direction. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] (One embodiment of the damper device) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a damper device according to the present invention will now be described with reference to the drawings.

[0012] 1 is attached to a pair of members that move toward or away from each other, and applies a braking force when the pair of members move toward or away from each other, and can be used, for example, to brake a glove box, lid, or the like that is attached so as to be able to open and close to the opening of a storage section provided in an instrument panel of an automobile. Note that in the following embodiments, one member will be described as a fixed body such as a storage section of an instrument panel, and the other member will be described as an opening / closing body such as a glove box or lid that is attached so as to be able to open and close to the opening of the fixed body.

[0013] As shown in Fig. 1, the damper device 10 of this embodiment is mainly composed of a cylinder 20 having an opening 23 at one end, a rod 30 that is movably inserted into the cylinder 20, a piston 40 that is connected to the rod 30 and has an annular groove 45 formed on its outer periphery, a seal ring 50 that is attached to the annular groove 45 of the piston 40, and a removal prevention cap 60 that is attached to the opening 23 at one end of the cylinder 20. As shown in Fig. 6, when the piston 40 is inserted into the cylinder 20, the seal ring 50 is pressed against the inner circumferential surface of the cylinder 20, and a first chamber V1 (air chamber) is formed on the side of the cylinder 20 in the insertion direction of the rod 30, with the seal ring 50 as the boundary, and a second chamber V2 is formed on the opening 23 side of the cylinder 20.

[0014] In the following description, "one end" or "one end" refers to one end or one end of the damper device 10 on the damper braking direction side, and "the other end" or "the other end" refers to the other end or the other end on the return direction side opposite the damper braking direction. Furthermore, the "damper braking direction" in this embodiment refers to the direction in which the piston 40 moves away from the end wall 25 of the cylinder 20 (see FIG. 6 ) and the amount of extension of the rod 30 from the opening 23 of the cylinder 20 increases (see arrow F1 in FIG. 6 ). Furthermore, the "return direction opposite to the damper braking direction" (hereinafter simply referred to as the "damper return direction") in this embodiment refers to the direction in which the piston 40 moves closer to the end wall 25 of the cylinder 20 and the amount of pushing of the rod 30 into the cylinder 20 increases (see arrow F2 in FIG. 6 ).

[0015] As shown in FIG. 1 , the wall 21 of the cylinder 20 has a cross section perpendicular to its axial direction that is annular with a major axis and a minor axis, with the major axis being wider and the minor axis being narrower, forming a thin, box-like cylindrical shape. More specifically, the wall 21 includes a pair of major axis walls 21a, 21a that extend linearly along the major axis and are arranged parallel to each other and facing each other, and a pair of minor axis walls 21b, 21b that connect both ends of the major axis walls 21a, 21a and are curved in an arc. One axial end of the wall 21 is open, forming an opening 23. Furthermore, locking holes 23a, 23a are formed in the opposing major axis walls 21a, 21a, respectively, around the periphery of the opening 23. Furthermore, as shown in Figure 6, an end wall 25 is arranged at the other axial end of wall portion 21 (it can also be said that end wall 25 is arranged on the opposite side of wall portion 21 from opening 23), and the other end of wall portion 21 is closed.

[0016] Furthermore, rotation support pieces 27 each having a rotation hole 27a protrude from the outer surface of the end wall 25 and from one axial end of the outer periphery of the wall portion 21. A rotation shaft (not shown) of one of the aforementioned 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.

[0017] As shown in FIG. 1, the detachment prevention cap 60 has a rod insertion opening 61 formed in its center, through which the shaft portion 31 of the rod 30 can be inserted while its rotation is restricted, allowing the rod 30 to be inserted into the cylinder 20 while its rotation is restricted. In addition, a plurality of locking projections 62 protrude from predetermined locations on the outer periphery of the detachment prevention cap 60, and the locking projections 62 are engaged with the corresponding locking holes 23a of the cylinder 20 (see FIG. 2), thereby allowing the detachment prevention cap 60 to be attached to the opening 23 of the cylinder 20 (see FIG. 6). When the rod 30 is fully pulled out from the opening 23 of the cylinder 20, the detachment prevention cap 60 abuts against the piston 40, preventing the rod 30 and piston 40 from coming off the cylinder 20.

[0018] Next, the rod 30 will be described.

[0019] The 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 .

[0020] 1, the rod 30 of this embodiment has a rectangular pillar-shaped shaft portion 31 that extends long in one direction. A connecting piece 33 having a connecting hole 33a is provided at one longitudinal end of the shaft portion 31. A connecting shaft (not shown) of the other member described above is inserted into this connecting hole 33a, so that the rod 30 is rotatably connected to the other member.

[0021] Next, the piston 40 will be described.

[0022] As shown in Figures 1 and 3, the piston 40 in this embodiment is connected to the other longitudinal end of the rod 30, has an annular groove 45 formed on its outer periphery, and is formed integrally with the rod 30.

[0023] 6 and 7, the piston 40 comprises a first side wall 41 and a second side wall 42 arranged parallel to each other and facing each other, and a connecting wall 43 connecting the two side wall portions 41, 42 to each other. Each side wall portion 41, 42 has a shape that matches the inner circumferential shape of the wall portion 21 of the cylinder 20, i.e., 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. The connecting wall portion 43 also has a similar shape, with its outer periphery smaller than the outer peripheries of the two side wall portions 41, 42.

[0024] The surface of the first side wall portion 41 facing the second side wall portion 42 is referred to 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 referred to as the inner surface 42a of the second side wall portion 42.

[0025] The space surrounded by the pair of side walls 41, 42 and the connecting wall 43 forms an annular groove 45. The outer peripheral surface of the connecting wall 43 forms a bottom surface 45a of the annular groove 45. The bottom surface 45a is formed so as to be parallel to the axial direction of the piston 40 (the direction along the axis C of the piston 40).

[0026] In addition, the axial base end of the rod 30 is connected to the outer surface (the surface opposite to the surface facing the second side wall portion 42) of the first side wall portion 41 located on one end side of the longitudinal direction of the piston 40, thereby integrating the piston 40 and the rod 30.

[0027] 6 and 7, a plurality of spaces K defined by partition walls 46 are provided inside the side wall portions 41, 42 and the connecting wall portion 43, and each space K is open on the side of the second side wall portion 42. Referring also to FIG. 3, a small-diameter round orifice 47 communicating with the predetermined space K is formed at a predetermined position of the first side wall portion 41, here, at one axial end side of the first side wall portion 41 and the center position in the width direction. This orifice 47 communicates the first chamber V1 and the second chamber V2 in the cylinder 20 with each other via the space K. The flow resistance of air passing through the orifice 47 adjusts the damping force of the damper.

[0028] 3, a pair of notched grooves 48, 48 are formed with a predetermined depth by cutting out the first side wall portion 41 and the connecting wall portion 43 at positions point-symmetrical with respect to the axis C of the piston 40. The notched grooves 48 form an exhaust flow path (described later) that exhausts air from the first chamber V1 to the second chamber V2 when the piston 40 moves in the return direction F2.

[0029] Next, the seal ring 50 will be described with reference to FIGS.

[0030] This seal ring 50 is made of an elastic material such as rubber or elastomer and is flexible and deformable, and has an annular base 51 disposed within the annular groove 45, at least two inner diameter side projections 53, 55 projecting from the inner diameter side surface of the base 51 (hereinafter simply referred to as the "inner diameter surface 51a"), and an outer diameter side projection 57 projecting from the outer diameter side surface of the base 51 (hereinafter simply referred to as the "outer diameter surface 51b") and coming into pressure contact with the inner peripheral surface of the cylinder 20. The inner diameter side surface and the outer diameter side surface of the base 51 can also be referred to as the "inner peripheral surface" and the "outer peripheral surface", respectively.

[0031] The base 51 has an annular shape that fits the outer peripheral shape of the annular groove 45 of the piston 40. The axial length W1 of the base 51, i.e., the length between one end face 51c and the other end face 51d in the axial direction of the base 51, is formed to be smaller than the axial width of the annular groove 45 (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), thereby allowing the seal ring 50 to move in the axial direction within the annular groove 45. In this embodiment, the inner circumferential surface of the cylinder 20 refers to the inner circumferential surface of the wall portion 21 that constitutes the cylinder 20, and this also applies to the following description.

[0032] 4 and 5 show the state before the seal ring 50 is attached to the annular groove 45, i.e., the free state before the seal ring 50 is pressed against the inner peripheral surface of the cylinder 20 and deformed. In the following description of the shape, structure, and layout (position and arrangement of each part) of the seal ring 50, unless otherwise specified, the shape, structure, and layout of the seal ring 50 in the free state are meant.

[0033] The inner diameter side protrusions in this embodiment consist of two protrusions protruding from both axial ends of the base 51 of the seal ring 50, namely, a first inner diameter side protrusion 53 protruding from one axial end of the inner diameter surface 51a of the base 51 and a second inner diameter side protrusion 55 protruding from the other axial end. In the following description of the seal ring 50, the term "axial direction" means the axial direction of the seal ring unless otherwise specified.

[0034] In addition, the protrusions 53, 55, and 57 protruding from the inner diameter surface 51a and the outer diameter surface 51b of the base 51 all have a shape that continues circumferentially from the inner peripheral surface and the outer peripheral surface of the base 51 radially outward from the base 51 to form a ring, that is, they are annular protrusions that are not interrupted midway around the base 51 in the circumferential direction.

[0035] The first inner diameter side protrusion 53 has an apex 53a that protrudes most from the inner diameter surface 51a of the base 51, an outer surface 53b located on the outer side in the axial direction, and an inner surface 53c located on the inner side in the axial direction. The inner surface 53c is a surface that faces the second inner diameter side protrusion 55 adjacent in the axial direction, and the outer surface 53b is a surface opposite to the surface (inner surface 53c) facing the second inner diameter side protrusion 55.

[0036] The second inner diameter side protrusion 55 has an apex 55a that protrudes most from the inner diameter surface 51a of the base 51, an outer surface 55b located on the outer side in the axial direction, and an inner surface 55c located on the inner side in the axial direction. The inner surface 55c is a surface that faces the first inner diameter side protrusion 53 adjacent in the axial direction, and the outer surface 55b is a surface opposite to the surface (inner surface 55c) facing the first inner diameter side protrusion 53.

[0037] Furthermore, the outer surface 55b of the inner diameter side protrusion (second inner diameter side protrusion 55) that is located furthest from the inner diameter side protrusion toward the return direction F2 opposite the damper braking direction F1 is shaped to slope toward the other inner diameter side protrusion adjacent to it in the axial direction as it moves away from the inner diameter surface 51a of the base 51.

[0038] Specifically, of the two inner diameter side protrusions 53, 55, the outer surface 55b of the second inner diameter side protrusion 55 located closest in the damper return direction F2 forms an inclined surface that slopes toward the axially adjacent first inner diameter side protrusion 53 as it moves away from the inner diameter surface 51a of the base 51. In addition, in this embodiment, the outer surface 53b of the first inner diameter side protrusion 53 located on the damper braking direction F1 side also forms an inclined surface that slopes toward the axially adjacent second inner diameter side protrusion 55 as it moves away from the inner diameter surface 51a of the base 51.

[0039] Furthermore, the outer surface 53b of the first inner diameter side protrusion 53 is a continuous surface (flush) with no steps relative to one axial end face 51c of the base 51, and similarly, the outer surface 55b of the second inner diameter side protrusion 55 is also a continuous surface with no steps relative to the other axial end face 51d of the base 51.

[0040] The apexes 53a, 55a of the inner diameter side projections 53, 55 are rounded to form arcuate curved surfaces. The inner surface 53c of the first inner diameter side projection 53 and the inner surface 55c of the second inner diameter side projection 55 are arranged facing each other and substantially parallel to each other (substantially perpendicular to the axial direction of the seal ring 50). The first inner diameter side projection 53 and the second inner diameter side projection 55 are shaped to be line-symmetrical with respect to the axial center line S (described below) of the seal ring 50, and have the same protruding height from the inner diameter surface 51a of the base 51.

[0041] To summarize, the inner diameter protrusions 53, 55 in this embodiment generally have a cross-sectional shape that is roughly a right-angled triangular mountain shape, with one side being almost vertical and the other side gradually becoming wider from the apex 53a, 55a toward the inner diameter surface 51a of the base 51.

[0042] In addition, R-shaped fillet portions 53d, 55d are formed at the boundary portion (corner portion) between the inner surface 53c of the first inner diameter side protrusion 53 and the inner diameter surface 51a of the base 51, and at the boundary portion (corner portion) between the inner surface 55c of the second inner diameter side protrusion 55 and the inner diameter surface 51a of the base 51, respectively.

[0043] On the other hand, the outer diameter side protrusion 57 is the outer diameter surface 51b of the base 51 and protrudes from its axial center position, and has an apex 57a that protrudes most from the outer diameter surface 51b of the base 51, an outer surface 57b located on one end side in the axial direction, and an outer surface 57c located on the other end side in the axial direction.

[0044] Furthermore, the apex 57a of the outer diameter side protrusion 57 has a rounded shape so as to form an arc-shaped curved surface. The apex 57a of the outer diameter side protrusion 57 is constantly in contact with the inner circumferential surface of the cylinder 20 and is pressed against the inner circumferential surface of the cylinder 20. Note that the above term "constantly" refers to all states that the piston 40 can be in within the cylinder 20, including a state in which the piston 40 is stationary, a state in which the piston 40 is moving in the damper braking direction F1, and a state in which the piston 40 is moving in the damper return direction F2 (the same applies to the following explanations).

[0045] Furthermore, both outer side surfaces 57b, 57c of the outer diameter side protrusion 57 are inclined surfaces that gradually widen the outer diameter side protrusion 57 as it approaches the outer diameter surface 51b of the base 51. That is, the outer diameter side protrusion 57 has a cross-sectional shape that gradually widens from its apex 57a toward the outer diameter surface 51b of the base 51, forming a substantially equilateral triangular mountain shape (which can also be said to have a flared shape). Note that both outer side surfaces 57b, 57c of the outer diameter side protrusion 57 are inclined so as to be line-symmetrical with respect to the axial center line S of the seal ring 50.

[0046] Furthermore, at the boundary portions (corner portions) between both outer side surfaces 57b, 57c of the outer diameter side protrusion 57 and the outer diameter surface 51b of the base portion 51, rounded fillet portions 57d, 57d are formed.

[0047] The seal ring 50 described above has a cross-sectional shape that is symmetrical across its entirety with respect to an axial centerline S (a line that is perpendicular to the axial direction of the seal ring 50 and passes through the apex 57a of the outer diameter side projection 57) that passes through the center in the axial direction (see FIG. 5). Furthermore, the components that make up the seal ring 50, namely, the base 51, the inner diameter side projections 53 and 55, and the outer diameter side projection 57, are all integrally formed.

[0048] In this seal ring 50, at least one of the inner diameter side projections 53, 55 abuts against the bottom surface 45a of the annular groove 45, and the outer diameter side projection 57 projects annularly so that the apex 57a of the outer diameter side projection 57 is located on the outer diameter surface 51b of the base 51 at a position corresponding to the space between the apexes 53a, 55a of the axially adjacent inner diameter side projections 53, 55. In other words, the apex 57a of the outer diameter side projection 57 is positioned offset from the apexes 53a, 55a of the inner diameter side projections 53, 55 in the axial direction of the seal ring 50 without overlapping with them.

[0049] In addition, the outer diameter side protrusion 57 is arranged so that the apex 57a of the outer diameter side protrusion 57 is positioned at a position corresponding to the midpoint between the apexes 53a, 55a of the two inner diameter side protrusions 53, 55 (a position between the apex 53a and the apex 55a).

[0050] Furthermore, the inner surfaces 53c, 55c of the axially adjacent inner diameter side protrusions 53, 55 are located axially outward of the apex 57a of the outer diameter side protrusion 57, and the width W2 between the two outer surfaces 57b, 57c of the outer diameter side protrusion 57 is formed smaller than the distance W3 between the apexes 53a, 55a of the axially adjacent inner diameter side protrusions 53, 55.

[0051] The width W2 between the outer surfaces 57b, 57c of the outer diameter side projection 57 means the length from a point P1 where a fillet portion 57d continuing from the base end of the outer surface 57b intersects with the outer diameter surface 51b of the base 51 to a point P2 where a fillet portion 57d continuing to the outer surface 57c intersects with the outer diameter surface 51b of the base 51. In other words, the width of the outer diameter side projection 57 includes the expanded portions of the fillets 57d, 57d connected to both outer surfaces 57b, 57c.

[0052] Furthermore, when the piston 40 is inserted into the cylinder 20 with the seal ring 50 attached to the annular groove 45, the outer diameter side protrusion 57 of the seal ring 50, whose inner diameter side protrusions 53, 55 abut against the bottom surface 45a of the annular groove 45, is pressed against the inner circumferential surface of the cylinder 20, causing the seal ring 50 to flex and deform as shown in Figures 7 and 8.

[0053] In this embodiment, as described above, when the piston 40 is inserted into the cylinder 20 and the outer diameter side protrusion 57, which is pressed against the inner peripheral surface of the cylinder 20, is pressed against the inner peripheral surface of the cylinder 20, the both side portions 51e, 51e of the outer diameter side protrusion 57 of the base 51 are flexed and deformed so as to be slightly curved radially inward of the seal ring 50 (see Figure 7), and accordingly the inner diameter side protrusions 53, 55 are flexed and deformed so as to spread toward both axial end sides of the seal ring 50. That is, the outer surfaces 53b, 55b of the inner diameter side protrusions 53, 55 deform so as to approach the surface of the inner surface of the annular groove 45 (the inner surfaces 41a, 42a of each side wall portion 41, 42), and the inner surfaces 53c, 55c of the inner diameter side protrusions 53, 55 deform so as to spread apart from each other, causing the pair of inner diameter side protrusions 53, 55 to flex and deform so as to spread apart toward both axial ends of the seal ring 50.

[0054] In addition, in this embodiment, when the protruding height of the outer diameter side protrusion 57 from the outer diameter surface 51b of the base 51 in the free state of the seal ring 50 before the seal ring 50 is attached to the annular groove 45 (the length between the apex 57a of the outer diameter side protrusion 57 and the outer diameter surface 51b of the base 51) is H, the radial length of the apexes 53a, 55a of the inner diameter side protrusions 53, 55 and the apex 57a of the outer diameter side protrusion 57 in the free state of the seal ring is L1, and the length between the inner surface of the cylinder 20 and the bottom surface 45a of the annular groove 45 where the inner diameter side protrusions 53, 55 abut is L2, the relationship is set so that H > L1 - L2.

[0055] Furthermore, in this embodiment, as shown in FIG. 5, the relationship between the above H, the overlap amount R1 of the outer diameter side protrusion 57 relative to the inner peripheral surface of the cylinder 20, and the overlap amount R2 of the inner diameter side protrusions 53, 55 relative to the bottom surface 45a of the annular groove 45 is set as follows:

[0056] 5, the amount of displacement between the apex 57a of the outer diameter side protrusion 57 in the seal ring free state and the apex 57a of the outer diameter side protrusion 57 that is in pressure contact with the inner peripheral surface of the cylinder when the seal ring 50 is installed in the annular groove 45 (see the two-dot chain line in FIG. 5) is defined as the overlap amount R1 of the outer diameter side protrusion 57 with respect to the inner peripheral surface of the cylinder 20. Also, the amount of displacement between the apex 53a, 55a of the inner diameter side protrusions 53, 55 in the seal ring free state and the apex 53a, 55a of the inner diameter side protrusions 53, 55 that is in contact with the bottom surface 45a of the annular groove 45 when the seal ring 50 is installed in the annular groove 45 (see the two-dot chain line in FIG. 5) is defined as the overlap amount R2 of the inner diameter side protrusions 53, 55 with respect to the bottom surface 45a of the annular groove 45. In this case, the relationship H is set so that R1+R2 holds.

[0057] Next, the operation of the seal ring 50 in the annular groove 45 when the piston 40 moves in the damper braking direction F1 and when the piston 40 moves in the damper return direction F2 will be described.

[0058] When the piston 40 is stationary, the seal ring 50 is disposed in the annular groove 45 with the apex 57a of the outer diameter side projection 57 pressed against the inner circumferential surface of the cylinder 20 and the apexes 53a, 55a of the inner diameter side projections 53, 55 abutting against the bottom surface 45a of the annular groove 45. In this case, as shown in Figures 7 and 8, the seal ring 50 is disposed in the cylinder 20 in a deformed state from the free state of the seal ring shown in Figure 5.

[0059] When the piston 40 moves in the damper braking direction F1 from this state, a frictional force acts on the outer diameter side protrusion 57 from the inner circumferential surface of the cylinder 20 in the opposite direction to the damper braking direction F1, and this frictional force pushes the seal ring 50 toward the damper return direction F2. As a result, as shown in FIG. 7 , the other axial end face 51d of the base 51 of the seal ring 50 abuts against the inner surface at the other axial end of the annular groove 45 (the inner surface 42a of the second side wall portion 42). This seals the gap between the inner surface at the other axial end of the annular groove 45 and the other end face 51d of the base 51, as well as the gap between the inner circumferential surface of the cylinder 20 and the outer circumferential surface of the seal ring 50. Furthermore, the openings of the pair of notched grooves 48, 48 on the second side wall portion 42 side are closed, so that the pressure in the first chamber V1 in the cylinder 20 is reduced, and the damper braking force is exerted.

[0060] On the other hand, when the piston 40 moves in the damper return direction F2, a frictional force acts on the outer diameter side protrusion 57 from the inner circumferential surface of the cylinder 20 in the opposite direction to the damper return direction F2, and this frictional force pushes the seal ring 50 toward the damper braking direction F1. As a result, as shown in FIG. 8, one axial end face 51c of the base 51 of the seal ring 50 abuts against the inner surface (inner surface 41a of the first side wall portion 41) at one axial end of the annular groove 45, and the other axial end face 51d of the base 51 moves away from the inner surface (inner surface 42a of the second side wall portion 42) at the other end of the annular groove 45. This opens the openings of the notched grooves 48 on the second side wall portion 42 side, allowing air from the first chamber V1 in the cylinder 20 to flow through the notched grooves 48 and into the second chamber V2, as shown by the arrows in FIG. 8. As a result, the damper braking force is released.

[0061] (Variation) The shapes and structures of the cylinder, rod, piston, seal ring, etc. that constitute the damper device of the present invention are not limited to the above-mentioned embodiments.

[0062] Although the wall 21 of the cylinder 20 in this embodiment is generally thin and tubular, the wall of the cylinder may be, for example, generally rectangular or cylindrical. In this case, it is preferable that the rod, piston, seal ring, seal cap, and removal prevention cap also have shapes corresponding to the wall of the cylinder.

[0063] Furthermore, in this embodiment, the cylinder 20 is closed by an end wall 25 disposed on the other end side in the axial direction, but for example, a structure may be adopted in which a through hole is formed in the end wall disposed on the other end of the cylinder, and this through hole is opened and closed with a seal cap.

[0064] Furthermore, although the rod 30 in this embodiment has a rectangular pillar-shaped shaft portion 31, the rod may have a structure consisting of, for example, a shaft portion and a pair of side walls arranged on both sides thereof via multiple ribs, or a structure consisting of a shaft portion having a long plate shape or a cylindrical shape, etc., as long as the pistons can be connected in series.

[0065] Furthermore, the bottom surface 45a of the annular groove 45 in the piston 40 of this embodiment is parallel to the axial direction of the piston 40, but the annular groove may have, for example, an inclined or stepped bottom surface.

[0066] Furthermore, the seal ring 50 of this embodiment has inner diameter side projections 53, 55 projecting from both axial ends of the inner diameter surface 51a, and although the seal ring 50 has two inner diameter side projections 53, 55, the number of inner diameter side projections may be three or more. Also, in this embodiment, both inner diameter side projections 53, 55 are configured to abut against the bottom surface 45a of the annular groove 45, but it is sufficient that at least one inner diameter side projection abuts against the bottom surface of the annular groove.

[0067] Furthermore, the outer surfaces 53b, 55b of the inner diameter side protrusions 53, 55 are flush with the axial end faces 51c, 51d of the base 51 without any steps, but the outer surfaces of the inner diameter side protrusions may also be positioned axially inward relative to the axial end faces 51c, 51d of the base (or may be arranged so as to have a step).

[0068] Although the inner surfaces 53c, 55c of the inner projections 53, 55 are parallel to each other, one or both of the inner surfaces may be inclined with respect to the axial direction of the piston. Furthermore, the outer surfaces of the inner projections may be perpendicular to the axial direction of the piston or inclined in directions away from each other.

[0069] Furthermore, both outer surfaces 57b, 57c of the outer diameter side protrusion 57 are inclined so as to be symmetrical with respect to the axial center line S of the seal ring 50, but for example, both outer surfaces of the outer diameter side protrusion may be inclined at different angles relative to the axial direction of the seal ring, or may be perpendicular to the axial direction of the piston.

[0070] 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 chamber V1 is applied, 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 released. However, conversely, the damper braking force may be applied when the piston 40 moves in a direction approaching the end wall 25 of the cylinder 20, and the damper braking force may be released when the piston 40 moves in a direction away from the end wall 25 of the cylinder 20.

[0071] Furthermore, in this embodiment, one member is a fixed body such as a storage section of an instrument panel, and the other member is an opening / closing body such as a glove box or lid, but the pair of members are not particularly limited as long as they can move toward and away from each other.

[0072] Furthermore, in this embodiment, an air chamber (first chamber V1) is formed inside the cylinder 20 on the side of the seal ring 50 in the insertion direction of the rod 30. However, an air chamber may be provided inside the cylinder on the side opposite the rod insertion direction. 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. Furthermore, a cap attached to an opening at one end of the cylinder is designed to seal the periphery of the opening and to seal the gap between the rod insertion opening and the rod inserted through the rod insertion opening, thereby providing a sealed air chamber inside the cylinder on the side opposite the rod insertion direction. When the piston moves in a direction away from the end wall of the cylinder (when it moves in the opposite direction to the rod insertion direction), the air chamber is pressurized, thereby exerting a damper braking force. Note that when the piston moves closer to the end wall of the cylinder (when it moves toward the rod insertion direction), the seal cap opens the exhaust hole, allowing the air in the air chamber to be exhausted, thereby releasing the damper braking force.

[0073] (Action and effect) Next, the effects of the damper device 10 having the above-described configuration will be described.

[0074] In this damper device 10, when one member (such as a fixed body) and the other member (such as an opening / closing body) are in close proximity to each other, the piston 40 is stationary within the cylinder 20. In this state, the top 57a of the outer diameter side protrusion 57 abuts against the inner circumferential surface of the cylinder 20, and the tops 53a, 55a of the inner diameter side protrusions 53, 55 abut against the bottom surface 45a of the annular groove 45, with the seal ring 50 disposed within the annular groove 45.

[0075] From the above state, when one member moves in a direction away from the other member (when the opening / closing body is opened from the fixed body), the piston 40 moves in the damper braking direction F1 within the cylinder 20, and the rod 30 is pulled out from the opening 23 side of the cylinder 20. Then, as explained in paragraph 0059 above, the first chamber V1 within the cylinder 20 is depressurized, so that a damper braking force is imparted to the piston 40, allowing the other member to move slowly relative to the one member (allowing the opening / closing body to be opened slowly from the fixed body).

[0076] Furthermore, when one member is moved closer to the other member (when closing the opening / closing body relative to the fixed body), the piston 40 moves within the cylinder 20 in the damper return direction F2, and the rod 30 is pushed into the cylinder 20.

[0077] As a result, a frictional force acts on the outer diameter side protrusion 57 from the inner surface of the cylinder 20 in the opposite direction to the damper return direction F2, and this frictional force pushes the seal ring 50 toward the damper braking direction F1.As explained in paragraph 0060 above, the openings of each notch groove 48 on the second side wall portion 42 side open, and the air in the first chamber V1 flows out through each notch groove 48 into the second chamber V2, thereby releasing the damper braking force.

[0078] When the piston 40 is inserted into the cylinder 20 with the seal ring 50 attached to the annular groove 45, the outer diameter side protrusion 57, which is pressed against the inner peripheral surface of the cylinder 20, is pressed against the inner peripheral surface of the cylinder 20, and at the same time, a reaction force F3 against the pressing force acts on the inner peripheral surface of the cylinder 20 via the outer diameter side protrusion 57.

[0079] At this time, in this damper device 10, at least one of the inner diameter side protrusions 53, 55 abuts against the bottom surface 45a of the annular groove 45, and the outer diameter side protrusion 57 is configured to protrude in an annular shape so that the apex 57a of the outer diameter side protrusion 57 is positioned on the outer diameter surface 51b of the base 51, at a position corresponding to the space between the apexes 53a, 55a of the inner diameter side protrusions 53, 55 adjacent in the axial direction.

[0080] This makes it easier for the seal ring 50 to flex and deform, thereby suppressing the reaction force F3 from the seal ring 50 acting on the inner circumferential surface of the cylinder 20. That is, the outer diameter side projection 57 is provided so that its apex 57a does not overlap with the apexes 53a, 55a of the inner diameter side projections 53, 55 in the axial direction of the seal ring 50 but is shifted relative to them. This allows the radial thickness of the seal ring 50 to be reduced, making it easier for the base 51 to flex and deform, thereby suppressing the reaction force F3 acting on the inner circumferential surface of the cylinder 20. As a result, the operating force of the piston 40 when the piston 40 moves in the damper return direction F2 can be reduced.

[0081] In addition, at least two inner diameter protrusions 53, 55 make it easier to maintain the seal ring 50 in a stable position, and when the piston 40 moves in the damper braking direction F1, the gap between the inner surface of the cylinder 20 and the outer surface of the seal ring 50 can be tightly sealed, ensuring the desired damper braking force.

[0082] In addition, in this embodiment, the inner diameter side protrusions 53, 55 consist of two protruding portions each protruding from both axial ends of the base 51, and the outer diameter side protrusion 57 is arranged so that the apex 57a of the outer diameter side protrusion 57 is positioned at a position corresponding to the midpoint between the apexes 53a, 55a of the two inner diameter side protrusions 53, 55 (a position between the apex 53a and the apex 55a).

[0083] According to the above embodiment, since the inner diameter side projections 53, 55 and the outer diameter side projection 57 have the above-described structure, the entire seal ring 50 can be easily shaped to be line-symmetrical with respect to the axial center line S. As a result, when the seal ring 50 is fitted into the annular groove 45, the seal ring 50 does not have any directionality, which improves the workability of fitting the seal ring 50 into the annular groove 45. In addition, the seal ring 50 fitted into the annular groove 45 can be more easily positioned in a stable manner.

[0084] Furthermore, in this embodiment, the inner surfaces 53c, 55c of the axially adjacent inner diameter side protrusions 53, 55 are located axially outward of the apex 57a of the outer diameter side protrusion 57, and the width W2 between the two outer surfaces 57b, 57c of the outer diameter side protrusion 57 is formed smaller than the distance W3 between the apexes 53a, 55a of the axially adjacent inner diameter side protrusions 53, 55.

[0085] According to the above embodiment, it is easier to ensure a wide gap between the axially adjacent inner diameter side protrusions 53, 55 (the axial gap of the seal ring 50), making it easier to flex and deform the base 51, and further reducing the operating force of the piston 40 when the piston 40 moves in the damper return direction F2.

[0086] In addition, in this embodiment, when the seal ring 50 is in a free state before being fitted into the annular groove 45, the protruding height of the outer diameter side protrusion 57 from the outer diameter surface 51b of the base 51 (the length between the apex 57a of the outer diameter side protrusion 57 and the outer diameter surface 51b of the base 51) is H, the radial length of the apexes 53a, 55a of the inner diameter side protrusions 53, 55 and the apex 57a of the outer diameter side protrusion 57 in the free state is L1, and the length between the inner peripheral surface of the cylinder 20 and the bottom surface 45a of the annular groove 45 where the inner diameter side protrusions 53, 55 abut is L2, the relationship H > L1 - L2 is satisfied.

[0087] According to the above embodiment, when the piston 40 is inserted into the cylinder 20 with the seal ring 50 attached to the annular groove 45, the outer diameter surface (outer diameter surface 51b) of the base 51 can be prevented from contacting the inner peripheral surface of the cylinder 20, and the operating force of the piston 40 when the piston 40 moves in the damper return direction F2 can be further reduced.

[0088] Furthermore, in this embodiment, the outer surface 55b of the inner diameter side protrusion (second inner diameter side protrusion 55) that is located furthest from the inner diameter side protrusion in the return direction F2 opposite the damper braking direction F1 is shaped to slope toward the other inner diameter side protrusion adjacent to it in the axial direction as it moves away from the inner diameter surface 51a of the base 51.

[0089] According to the above embodiment, with the seal ring 50 attached to the annular groove 45, the second inner diameter side protrusion 55 can be prevented from widening beyond the other axial end face 51d of the base portion 51, thereby improving the sealing performance between the inner surface of the annular groove 45 located in the damper return direction F2 (the inner surface 42a of the second side wall portion 42) and the seal ring 50. As a result, when the piston 40 moves in the damper braking direction F1, the desired damper braking force can be reliably exerted.

[0090] In this embodiment, both outer side surfaces 57b, 57c of the outer diameter side protrusion 57 form inclined surfaces that gradually widen the outer diameter side protrusion 57 as it approaches the outer diameter surface 51b of the base 51.

[0091] According to the above embodiment, the outer diameter side protrusion 57 has a so-called flared shape, so that even if a frictional force from the inner circumferential surface of the cylinder 20 acts on the outer diameter side protrusion 57 when the piston 40 moves in the damper braking direction F1, the outer diameter side protrusion 57 is less likely to collapse (be less likely to deform). As a result, the sealing performance of the outer diameter side protrusion 57 with respect to the inner circumferential surface of the cylinder 20 is more easily maintained, so that the damper braking force can be stably exerted.

[0092] Furthermore, 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 symbols]

[0093] 10 Damper device 20 cylinders 23 Opening 30 rods 40 pistons 45 Annular groove 45a Bottom 50 Seal Ring 51 Base 53 First inner diameter protrusion 53a Top 53b External surface 53c inner surface 55 Second inner diameter protrusion 55a top 55b External surface 55c inner surface 57 Outer diameter side protrusion 57а top 57b,57c outer surface 60 Prevention Cap

Claims

1. A damper device that is attached between a pair of members that move toward or away from each other and that applies a braking force when the pair of members move toward or away from each other, 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 that is fitted in the annular groove and is pressed against the inner circumferential surface of the cylinder, The seal ring is a base portion having an annular shape and disposed within the annular groove; At least two inner diameter side protrusions protruding from an inner diameter side surface of the base portion; an outer diameter side protrusion that protrudes from the outer diameter side surface of the base and abuts against the inner circumferential surface of the cylinder, At least one of the inner diameter side protrusions abuts against the bottom surface of the annular groove, an outer surface of the inner diameter side protrusion that is located furthest to the return direction side opposite the damper braking direction, the entire area from the inner diameter side surface of the base to the apex of the inner diameter side protrusion is inclined toward another inner diameter side protrusion adjacent in the axial direction as it moves away from the inner diameter side surface of the base, A damper device characterized in that the outer diameter side protrusion protrudes in an annular shape from the outer diameter side surface of the base so that the apex of the outer diameter side protrusion is positioned at a position corresponding to the space between the apexes of the inner diameter side protrusions adjacent to each other in the axial direction.

2. the inner diameter side protrusions are composed of two protruding portions protruding from both axial end portions of the base portion, 2. The damper device according to claim 1, wherein the outer diameter side projection is provided so that the top of the outer diameter side projection is located at a position corresponding to the middle between the tops of the two inner diameter side projections.

3. an inner surface of the inner diameter side protrusion adjacent in the axial direction is located axially outward of a top of the outer diameter side protrusion, 3. The damper device according to claim 1, wherein the width between both outer side surfaces of said outer projections is smaller than the distance between the tops of said inner projections adjacent in the axial direction.

4. a protruding height of the outer diameter side protrusion from the outer diameter side surface of the base portion in a free state of the seal ring before the seal ring is fitted into the annular groove is defined as H; L1 is the radial length between the top of the inner diameter side protrusion and the top of the outer diameter side protrusion in the free state, When the length between the inner peripheral surface of the cylinder and the bottom surface of the annular groove on which the inner diameter side protrusion abuts is L2, 3. The damper device according to claim 1, wherein the damper is set so that H>L1-L2.

5. 3. The damper device according to claim 1, wherein both outer surfaces of the outer projection form inclined surfaces that gradually widen as the outer projection approaches the outer surface of the base.

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