JP7765600B2 - Damper Device - Google Patents

Description

The present invention relates to a damper device used, for example, to brake the opening and closing of an automobile glove box.

For example, a damper device is sometimes used in a car's glove box to prevent the lid from opening suddenly and to allow it to open more slowly.

As an example of such a damper device, the following Patent Document 1 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 mounted in an annular groove formed on the outer periphery of the piston head.

The lip seal has a roughly U-shaped cross section and consists of a base, an inner lip that protrudes from the inner edge of one axial end of the base and abuts the bottom of the annular groove, and an outer lip that protrudes from the outer edge of one axial end of the base and abuts the inner surface of the housing. The outer lip protrudes diagonally outward from the inner lip, and typically the tip of the outer surface of the outer lip partially abuts against the inner surface of the housing.

Japanese Patent Application Publication No. 8-277873

In the air damper assembly of Patent Document 1, when the piston head moves in the return direction opposite the damper braking direction, the piston rod may tilt relative to the axis of the housing. In this case, the piston head also tilts in response to 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.

Therefore, the 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.

To achieve the above-mentioned objective, the present invention provides a damper device that is attached between 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. The damper device comprises 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 pressed against the inner circumferential surface of the cylinder. The seal ring has an annular base that is positioned 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 on the outer diameter side surface of the base so that the apex of the outer diameter side protrusion is positioned between the apexes of the axially adjacent inner diameter side protrusions.

In the present invention, the outer diameter side protrusion protrudes annularly 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 axially adjacent inner diameter side protrusions. This makes it easier for the seal ring to flex and deform, reducing 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.

1 is an exploded perspective view showing an embodiment of a damper device according to the present invention. FIG. FIG. 2 is an enlarged perspective view of a piston that constitutes the damper device. FIG. 2 is an enlarged perspective view of a seal ring that constitutes the damper device. 5 is a cross-sectional view taken along the line BB in FIG. 4. 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. 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. 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.

(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.

The damper device 10 shown in Figure 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. It can be used, for example, to brake a glove box or lid that is openably attached to the opening of a storage section in an automobile instrument panel. In the following embodiments, one member is described as a fixed body such as a storage section in an instrument panel, and the other member is described as an openable/closable body such as a glove box or lid that is openably attached to the opening of the fixed body.

As shown in FIG. 1, the damper device 10 of this embodiment is primarily composed of a cylinder 20 with 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 45 formed on its outer periphery, a seal ring 50 attached to the annular groove 45 of the piston 40, and a retaining cap 60 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. A first chamber V1 (air chamber) is formed on the side of the cylinder 20 facing the insertion direction of the rod 30, and a second chamber V2 is formed on the opening 23 side of the cylinder 20.

In the following description, "one end" or "one end" refers to the 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, in this embodiment, the "damper braking direction" refers to the direction in which the piston 40 moves away from the end wall 25 of the cylinder 20 (see Figure 6) and the amount of extension of the rod 30 from the opening 23 of the cylinder 20 increases (see arrow F1 in Figure 6). Furthermore, in this embodiment, the "return direction opposite the damper braking direction" (hereinafter simply referred to as the "damper return direction") refers to the direction in which the piston 40 approaches 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 Figure 6).

As shown in FIG. 1, the wall 21 of the cylinder 20 has a cross section perpendicular to its axial direction that forms an annular shape with a major axis and a minor axis. The cross section is wide on the major axis side and narrow on the minor axis side, forming a thin, box-like cylindrical shape. More specifically, the wall 21 extends linearly along the major axis direction and includes a pair of major axis walls 21a, 21a arranged parallel to each other and facing each other. A pair of minor axis walls 21b, 21b connect the 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 the wall portion 21 (in other words, the end wall 25 is arranged on the opposite side of the wall portion 21 from the opening 23), and the other end of the wall portion 21 is closed.

In addition, a rotation support piece 27, which has a rotation hole 27a formed therein, protrudes 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 components 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 components.

As shown in FIG. 1, the anti-detachment 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 restricting rotation, allowing the rod 30 to be inserted into the cylinder 20 while restricting rotation. Additionally, multiple locking protrusions 62 protrude from predetermined locations on the outer periphery of the anti-detachment cap 60. Each locking protrusion 62 is engaged with a corresponding locking hole 23a of the cylinder 20 (see FIG. 2), allowing the anti-detachment cap 60 to be attached to the opening 23 of the cylinder 20 (see FIG. 6). When the rod 30 is fully extended from the opening 23 of the cylinder 20, the anti-detachment cap 60 abuts against the piston 40, preventing the rod 30 and piston 40 from coming off the cylinder 20.

Next, we will explain the rod 30.

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

As shown in Figure 1, the rod 30 in this embodiment has a rectangular pillar-shaped shaft portion 31 that extends elongated in one direction. One longitudinal end of the shaft portion 31 is provided with a connecting piece 33 with a connecting hole 33a. A connecting shaft (not shown) of the other component mentioned above is inserted into this connecting hole 33a, allowing the rod 30 to be rotatably connected to the other component.

Next, we will explain the piston 40.

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.

Referring to Figures 6 and 7 together, the piston 40 comprises a first side wall portion 41 and a second side wall portion 42, which are arranged parallel to each other and face each other, and a connecting wall portion 43 that connects 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. Furthermore, the connecting wall portion 43 has a similar shape, with its outer periphery being smaller than the outer peripheries of the two side wall portions 41, 42.

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.

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 the 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).

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

6 and 7, multiple 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 toward the second side wall portion 42. Also referring to FIG. 3, a small-diameter, round orifice 47 communicating with the predetermined space K is formed at a predetermined position on the first side wall portion 41, in this case, at one axial end of the first side wall portion 41 and the center position in the width direction. This orifice 47 connects the first chamber V1 and the second chamber V2 within the cylinder 20 via the space K. The flow resistance of air passing through the orifice 47 adjusts the damper braking force.

3, a pair of notched grooves 48, 48 are formed at 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. These notched grooves 48 form an exhaust flow path that exhausts air from the first chamber V1 to the second chamber V2 when the piston 40 moves in the return direction F2 (this will be described later).

Next, the seal ring 50 will be described with reference to Figures 4 and 5.

This seal ring 50 is made of an elastic material such as rubber or elastomer and is flexible and deformable. It has an annular base 51 placed within the annular groove 45, at least two inner diameter side projections 53, 55 protruding 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 protruding from the outer diameter side surface of the base 51 (hereinafter simply referred to as the "outer diameter surface 51b") and pressing against the inner peripheral surface of the cylinder 20. The inner diameter side surface and outer diameter side surface of the base 51 can also be referred to as the "inner peripheral surface" and the "outer peripheral surface," respectively.

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 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 axially within the annular groove 45. In this embodiment, the inner peripheral surface of the cylinder 20 refers to the inner peripheral surface of the wall portion 21 that constitutes the cylinder 20, and this also applies in the following description.

Figures 4 and 5 show the state before the seal ring 50 is installed in the annular groove 45, i.e., the free state before the seal ring 50 is pressed against the inner surface of the cylinder 20 and deformed. Note that in the following explanations of the shape, structure, and layout (position and arrangement of each part) of each part of the seal ring 50, unless otherwise specified, this refers to the shape, structure, and layout of the seal ring 50 in its free state.

In this embodiment, the inner diameter side protrusions consist of two protrusions protruding from both axial ends of the base 51 of the seal ring 50: 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, "axial direction" refers to the axial direction of the seal ring unless otherwise specified.

In addition, the protrusions 53, 55, and 57 protruding from the inner diameter surface 51a and outer diameter surface 51b of the base 51 each have a circular shape that extends from the inner and outer peripheral surfaces of the base 51 radially outward from the base 51, forming a continuous ring-shaped protrusion that is not interrupted midway around the circumference of the base 51.

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 outside in the axial direction, and an inner surface 53c located on the inside in the axial direction. The inner surface 53c faces the second inner diameter side protrusion 55 adjacent in the axial direction, and the outer surface 53b is the surface opposite the surface (inner surface 53c) facing the second inner diameter side protrusion 55.

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 outside in the axial direction, and an inner surface 55c located on the inside in the axial direction. The inner surface 55c faces the first inner diameter side protrusion 53 adjacent in the axial direction, and the outer surface 55b faces the opposite side from the surface (inner surface 55c) facing the first inner diameter side protrusion 53.

Furthermore, the outer surface 55b of the inner diameter side protrusion (second inner diameter side protrusion 55) that is located furthest from the damper braking direction F1 in the return direction F2 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.

Specifically, of the two inner diameter side protrusions 53, 55, the outer surface 55b of the second inner diameter side protrusion 55, which is 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, which is located closer to the damper braking direction F1, 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.

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.

The apex 53a, 55a of each inner diameter side protrusion 53, 55 is rounded to form an arc-shaped curved surface. Furthermore, the inner surface 53c of the first inner diameter side protrusion 53 and the inner surface 55c of the second inner diameter side protrusion 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 protrusion 53 and the second inner diameter side protrusion 55 are shaped to be line-symmetrical with respect to the axial centerline S (described below) of the seal ring 50, and protrude to the same height from the inner diameter surface 51a of the base 51.

To summarize the above, in this embodiment, the inner diameter protrusions 53, 55 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 widening from the apex 53a, 55a toward the inner diameter surface 51a of the base 51.

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.

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 a peak 57a that protrudes most from the outer diameter surface 51b of the base 51, an outer surface 57b located at one end in the axial direction, and an outer surface 57c located at the other end in the axial direction.

The apex 57a of the outer diameter side protrusion 57 has a rounded shape that forms 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 presses against the inner circumferential surface of the cylinder 20. Note that "constantly" above refers to all possible states of the piston 40 within the cylinder 20, including when the piston 40 is stationary, when the piston 40 is moving in the damper braking direction F1, and when the piston 40 is moving in the damper return direction F2 (the same applies in the following explanations).

Furthermore, both outer side surfaces 57b, 57c of the outer diameter side protrusion 57 are inclined so that the outer diameter side protrusion 57 gradually widens 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 is a roughly equilateral triangular mountain shape (which can also be described as a shape with a flared base) that gradually widens from its apex 57a toward the outer diameter surface 51b of the base 51. The outer side 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.

In addition, R-shaped fillet portions 57d, 57d are formed at the boundary (corner) portions between the two outer surfaces 57b, 57c of the outer diameter side protrusion 57 and the outer diameter surface 51b of the base 51.

The seal ring 50 described above has a cross-sectional shape that is symmetrical across the entire axial centerline S (a line perpendicular to the axial direction of the seal ring 50 and passing through the apex 57a of the outer diameter side protrusion 57) (see Figure 5). Furthermore, all of the components that make up the seal ring 50, namely the base 51, the inner diameter side protrusions 53 and 55, and the outer diameter side protrusion 57, are integrally formed.

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 protrudes annularly so that the apex 57a of the outer diameter side projection 57 is positioned on the outer diameter surface 51b of the base 51, 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 relative to 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.

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 (the position between the apex 53a and the apex 55a).

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.

The width W2 between the outer surfaces 57b, 57c of the outer diameter side protrusion 57 refers to the length from point P1 where the fillet 57d continuing from the base end of the outer surface 57b intersects with the outer diameter surface 51b of the base 51 to point P2 where the fillet 57d continuing from 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 protrusion 57 includes the expanded portions of the fillets 57d, 57d connected to both outer surfaces 57b, 57c.

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 surface of the cylinder 20, causing the seal ring 50 to flex and deform as shown in Figures 7 and 8.

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 surface of the cylinder 20, is pressed against the inner 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 ends 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 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.

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 installed in 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 apex 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.

Furthermore, in this embodiment, as shown in Figure 5, the relationship between the above H, the overlap amount R1 of the outer diameter side protrusion 57 relative to the inner 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:

That is, as shown in FIG. 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 presses against 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 relative to the inner peripheral surface of the cylinder 20. Furthermore, 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 abuts against the bottom surface of the annular groove 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 relative to the bottom surface 45a of the annular groove 45. In this case, the relationship H is set so that R1 + R2 holds.

Next, we will explain the operation of the seal ring 50 within the annular groove 45 when the piston 40 moves in the damper braking direction F1 and when it moves in the damper return direction F2.

When the piston 40 is stationary, the seal ring 50 is positioned within 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 the bottom surface 45a of the annular groove 45. In this case, as shown in Figures 7 and 8, the seal ring 50 is positioned within the cylinder 20 in a deformed state from the free state of the seal ring shown in Figure 5.

When the piston 40 moves in the damper braking direction F1 from this state, a frictional force acts on the outer diameter protrusion 57 from the inner surface of the cylinder 20 in the opposite direction to the damper braking direction F1, pushing the seal ring 50 in 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 of 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 of 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 surface of the cylinder 20 and the outer 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, thereby reducing the pressure in the first chamber V1 within the cylinder 20 and exerting damper braking force.

On the other hand, when the piston 40 moves in the damper return direction F2, a frictional force acts on the outer diameter protrusion 57 from the inner surface of the cylinder 20 in the opposite direction to the damper return direction F2, pushing 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 of one axial end of the annular groove 45 (the inner surface 41a of the first side wall portion 41), while the other axial end face 51d of the base 51 moves away from the inner surface of the other axial end of the annular groove 45 (the inner surface 42a of the second side wall portion 42). This opens the openings of each notch groove 48 on the second side wall portion 42 side, allowing air from the first chamber V1 in the cylinder 20 to flow through the notch 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.

(Modification)
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.

In this embodiment, the wall 21 of the cylinder 20 is generally thin and tubular, but the wall of the cylinder may also be, for example, generally rectangular or cylindrical. In this case, it is preferable that the rod, piston, seal ring, seal cap, and anti-detachment cap also have a shape corresponding to the wall of the cylinder.

In addition, in this embodiment, the cylinder 20 is closed by an end wall 25 located on the other axial end side, but it may also be structured, for example, such that a through hole is formed in the end wall located at the other end of the cylinder and this through hole is opened and closed with a seal cap.

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 in the shape of a long plate or cylinder, etc., as long as the pistons can be connected in series.

In addition, the bottom surface 45a of the annular groove 45 in the piston 40 in 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.

Furthermore, the seal ring 50 in this embodiment has inner diameter side projections 53, 55 protruding from both axial ends of the inner diameter surface 51a. While there are two inner diameter side projections 53, 55, three or more inner diameter side projections are acceptable. Also, in this embodiment, both inner diameter side projections 53, 55 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.

Furthermore, the outer surfaces 53b, 55b of the inner diameter side protrusions 53, 55 are flush with both axial end surfaces 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 both axial end surfaces of the base (or may be arranged so as to have a step).

The inner surfaces 53c, 55c of the inner diameter side protrusions 53, 55 are parallel to each other, but 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 diameter side protrusions may be perpendicular to the axial direction of the piston or inclined in directions that move away from each other.

In addition, the two 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, the two 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.

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 reduced pressure in 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), this braking force is released. However, the configuration may also be reversed, such that a damper braking force is applied when the piston 40 moves in a direction approaching the end wall 25 of the cylinder 20, and the damper braking force is released when the piston 40 moves in a direction away from the end wall 25 of the cylinder 20.

In addition, 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.

Furthermore, in this embodiment, an air chamber (first chamber V1) is formed within the cylinder 20 on the side of the seal ring 50 in the direction of rod 30 insertion. However, an air chamber may also be provided on the side of the cylinder 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 the 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 on the side of the cylinder opposite the rod insertion direction. When the piston moves away from the end wall of the cylinder (when moving opposite 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 moving toward the rod insertion direction), the seal cap opens the exhaust hole, allowing air to be exhausted from the air chamber and releasing the damper braking force.

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

When one component (e.g., a fixed body) of this damper device 10 is in close proximity to the other component (e.g., an opening/closing body), the piston 40 is stationary within the cylinder 20. In this state, the apex 57a of the outer diameter side protrusion 57 abuts the inner circumferential surface of the cylinder 20, and the apexes 53a, 55a of the inner diameter side protrusions 53, 55 abut the bottom surface 45a of the annular groove 45, with the seal ring 50 positioned within the annular groove 45.

When, from the above state, one of the components moves away from the other (when the opening/closing body opens from the fixed body), 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. As explained in paragraph 0059 above, the first chamber V1 within the cylinder 20 is then depressurized, and a damper braking force is applied to the piston 40, allowing the other component to move slowly relative to the other component (allowing the opening/closing body to open slowly from the fixed body).

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.

As a result, a frictional force acts on the outer diameter protrusion 57 from the inner surface of the cylinder 20 in the opposite direction to the damper return direction F2, pushing 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, releasing the damper braking force.

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 surface of the cylinder 20, is pressed against the inner surface of the cylinder 20. At the same time, a reaction force F3 against the pressing force acts on the inner surface of the cylinder 20 via the outer diameter side protrusion 57.

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 axially adjacent inner diameter side protrusions 53, 55.

This allows the seal ring 50 to more easily flex and deform, thereby suppressing the reaction force F3 from the seal ring 50 acting on the inner circumferential surface of the cylinder 20. Specifically, the outer diameter side projection 57 is positioned 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 offset from them. This reduces the radial thickness of the seal ring 50, making it easier for the base 51 to flex and 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 it moves in the damper return direction F2 can be reduced.

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

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 (the position between the apex 53a and the apex 55a).

According to the above aspect, because the inner diameter side protrusions 53, 55 and the outer diameter side protrusion 57 have the above-described structure, the entire seal ring 50 can be easily shaped to be line-symmetrical with respect to the axial centerline 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, improving the ease 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.

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 to be smaller than the distance W3 between the apexes 53a, 55a of the axially adjacent inner diameter side protrusions 53, 55.

According to the above-mentioned aspect, 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.

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 installed in 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 apex 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 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.

According to the above aspect, 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, thereby further reducing the operating force of the piston 40 when the piston 40 moves in the damper return direction F2.

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.

According to the above aspect, when the seal ring 50 is 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 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, the desired damper braking force can be reliably exerted when the piston 40 moves in the damper braking direction F1.

In addition, in this embodiment, both outer 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.

According to the above-described embodiment, the outer diameter side protrusion 57 has a so-called flared shape. This makes it difficult for the outer diameter side protrusion 57 to collapse (become less likely to deform) even when 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. As a result, it becomes easier to maintain the sealing ability of the outer diameter side protrusion 57 against the inner circumferential surface of the cylinder 20, allowing the damper braking force to be exerted stably.

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.

10 Damper device 20 Cylinder 23 Opening 30 Rod 40 Piston 45 Annular groove 45a Bottom surface 50 Seal ring 51 Base 53 First inner diameter side protrusion 53a Top 53b Outer surface 53c Inner surface 55 Second inner diameter side protrusion 55a Top 55b Outer surface 55c Inner surface 57 Outer diameter side protrusion 57a Tops 57b, 57c Outer surface 60 Prevention cap

Claims (5)

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. 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. 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. 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. 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.