Damper device

Abstract

Provided is a damper device that can easily realize a structure capable of changing damper brake force in accordance with a load acting on a piston. A damper device 10 comprises a cylinder 20, a rod 30, a piston 40, and a seal member 70. The piston 40 includes: a rod connection portion 42; a flange portion 43 having an abutting surface 44; an axial groove 46; and an orifice groove 50 having a bottom portion 51 and both side surfaces 53, 53 and formed in a recessed groove shape extending toward an outside edge 43a of the flange portion 43. The orifice groove 50 is formed such that the opening width on the abutting surface 44 is larger than the depth from the abutting surface 44 to the bottom portion 51, and the seal member 70 can fit in the orifice groove 50 when the piston 40 moves in a damper braking direction.

Description

Damper device

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

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

[0003] For example, in Patent Document 1 below, it consists of a piston and a housing. The piston includes a seal member against the inner wall of the housing and a slider that contacts the inner wall of the housing with a predetermined frictional force. When braking force is generated, the slider presses against the seal member, and the portion of the seal member that contacts the inner wall of the housing is deformed toward the outside of the housing. Inside the portion of the seal member that contacts the inner wall of the housing, a deformation control portion that suppresses the inward deformation of the seal member into the housing is provided. A damper is described.

[0004] Further, the piston has a body portion and a first flange that extends from one end of the body portion. A groove forming a ventilation path is formed from the edge of this first flange toward the body portion (paragraph 0029 of Patent Document 1, FIG. 7 of Patent Document 1). Further, a seal member is attached to the outer periphery of the body portion of the piston on the first flange side, and a slider is attached to a location separated from the first flange (FIG. 8 of Patent Document 1).

[0005] When the piston moves forward, the lip of the slider and the skirt portion of the seal member contact the inner wall of the housing, the chamber in the housing becomes negative pressure, and braking force is exerted. At this time, air flows through the groove formed in the first flange. Further, the damper of Patent Document 1 is configured such that the deformation amount of the seal member increases according to the operating speed of the piston, and it is a load response type damper that changes the braking force according to the moving speed of the braking target (paragraph 0030 of Patent Document 1).

[0006] Japanese Patent Application Laid-Open No. 2018-71595

[0007] As described above, the damper in Patent Document 1 is configured to change the braking force by increasing the amount of deformation of the sealing member according to the operating speed of the piston, and the groove formed in the first flange of the piston does not contribute to the change in braking force, making the structure for changing the braking force complex.

[0008] Therefore, the object of the present invention is to provide a damper device that can easily incorporate a structure that changes the damper braking force in accordance with the load acting on the piston.

[0009] To achieve the above objective, the present invention provides a damper device that is attached between a pair of members that move closer to or further apart from each other, and that applies a braking force when the pair of members move closer to or further apart, comprising: a cylinder with an opening at one end; a rod inserted into the cylinder; a piston connected to the rod and having an annular groove formed on its outer circumference; and a sealing member disposed axially movable within the annular groove, wherein the piston has a rod connecting portion to which the rod is connected, and a contact surface formed on the opposite side of the rod connecting portion and which the sealing member contacts. The device has a lunge portion, an axial groove formed between the flange portion and the rod connecting portion, communicating with the annular groove and extending in the axial direction, and an orifice groove formed on the contact surface that communicates with the axial groove and has a bottom and both sides, and is concave in shape and extends toward the outer edge of the flange portion, wherein the opening width of the orifice groove on the contact surface is larger than the depth from the contact surface to the bottom, and the seal member is able to enter the orifice groove when the piston moves in the damper braking direction.

[0010] In the present invention, the orifice groove is formed such that the opening width at the contact surface is larger than the depth from the contact surface to the bottom, allowing the sealing member to enter the orifice groove when the piston moves in the damper braking direction.

[0011] Therefore, by making it easier for the sealing member to enter the orifice groove, it is possible to easily adjust the amount of the sealing member that enters the orifice groove in response to changes in the load acting on the piston. As a result, a structure that changes the damper braking force by appropriately changing the size of the internal space of the orifice groove in response to the load acting on the piston and thereby increasing or decreasing the amount of air flowing through the orifice groove can be easily realized with the above configuration of the orifice groove.

[0012] This is an exploded perspective view showing one embodiment of the damper device according to the present invention. This is a perspective view of the damper device. This is an enlarged perspective view of the main part of the damper device. This is an enlarged side view of the main part of the damper device. This is a cross-sectional view of the orifice groove constituting the damper device, taken along the line of arrow A-A in Figure 1. This is a cross-sectional view of a seal ring, which is one of the seal members constituting the damper device. This is a cross-sectional view of the damper device. This is a cross-sectional view of the damper device when the piston moves in the damper braking direction from the state in Figure 7. This is an enlarged cross-sectional view of the main part of Figure 8. This is an explanatory diagram of the damper device in a state where the seal member is not engaged in the orifice groove. This is an explanatory diagram of the damper device in a state where the seal member is engaged in the orifice groove. This is an explanatory diagram of the damper device in a state where the seal member is engaged in the orifice groove more than in Figure 10B. This is a cross-sectional view of the damper device when the piston moves in the return direction opposite to the damper braking direction. This is an enlarged cross-sectional view of the main part of Figure 11. This shows another embodiment of the damper device according to the present invention, and is an enlarged perspective view of its main part. This is an enlarged side view of the main part of the damper device.

[0013] (An Embodiment of a Damper Device) Hereinafter, an embodiment of a damper device according to the present invention will be described with reference to the drawings.

[0014] The damper device 10 shown in Figures 1 and 2 is attached to a pair of members that move closer to or further apart from each other, and applies a braking force when the pair of members move closer or further apart. For example, it can be used as a brake for a glove box or lid that is attached to the opening of a storage compartment in the instrument panel of an automobile so as to be openable and closable. In the following embodiments, one member will be described as a fixed body such as a storage compartment in the instrument panel, and the other member will be described as an opening and closing body such as a glove box or lid that is attached to the opening of the fixed body so as to be openable and closable.

[0015] As shown in Figure 1, the damper device 10 of this embodiment includes a cylinder 20 having an opening 22 at one end, a cap 25 fitted to the opening 22, 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 circumference, and a sealing member 70 axially movable within the annular groove 45. In this invention, "axial" means the direction of movement of the piston 40, that is, the direction in which the piston 40 moves relative to the cylinder 20.

[0016] Furthermore, the sealing member 70 consists of a sealing ring 71 which is arranged within the annular groove 45 so as to be axially movable toward the damper braking direction F1 (see arrow in Figure 7) and is pressed against the inner circumferential surface of the cylinder 20, and a friction member 75 which is arranged within the annular groove 45 toward the return direction F2 (see arrow in Figure 8), opposite to the damper braking direction F1, relative to the sealing ring 71.

[0017] In the following description, "one end" or "one end" refers to the 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 on the return direction side opposite to the damper braking direction. Furthermore, in this embodiment, "damper braking direction" refers to the direction in which the piston 40 moves away from the end wall 23 of the cylinder 20 (see Figure 7), and the amount of rod 30 pulled out from the opening 22 of the cylinder 20 increases (see arrow F1 in Figure 7). Moreover, in this embodiment, "return direction opposite to the damper braking direction" (hereinafter also simply referred to as "damper return direction") refers to the direction in which the piston 40 approaches the end wall 23 of the cylinder 20, and the amount of rod 30 pushed into the cylinder 20 increases (see arrow F2 in Figure 8).

[0018] Furthermore, an air chamber is formed inside the cylinder 20 on the side of the piston 40 insertion direction via a sealing member 70. In this embodiment, as shown in Figure 7, when the piston 40 is inserted into the cylinder 20, the outer diameter projection 73 of the sealing ring 71, which will be described later, is pressed against the inner circumferential surface of the cylinder 20, thereby sealing the gap between the cylinder 20 and the piston 40. As a result, a first air chamber V1 is formed on the side of the cylinder 20 in the direction of the piston 40 insertion, and a second air chamber V2 is formed on the side of the opening 22 of the cylinder 20.

[0019] As shown in Figure 1, the cylinder 20 has a cylindrical wall portion 21. This wall portion 21 has an annular cross-section with a long axis and a short axis, perpendicular to the direction of movement of the piston 40 (also known as the direction perpendicular to the axial direction of the cylinder 20), with the long axis side being wider and the short axis side being narrower, resulting in a thin cylindrical shape (a cylindrical shape resembling a thin box).

[0020] Furthermore, one end of the wall portion 21 in the axial direction is open, and an opening 22 is provided. As shown in Figure 7, an end wall 23 is positioned at the other end of the wall portion 21 in the axial direction, closing off the other end of the wall portion 21.

[0021] Furthermore, a rotating support piece 24, each having a rotating hole 24a, is provided protruding from the outer surface of the end wall 23 and from one axial end of the outer circumference of the wall portion 21 (see Figures 1 and 2). A rotating shaft (not shown) of one of the aforementioned members is rotatably inserted into the predetermined rotating hole 24a, so that the outer circumference of the cylinder 20 is rotatably connected to the other member.

[0022] Furthermore, the cap 25 fitted to the opening 22 of the cylinder 20 has an insertion opening 25a formed in its center, allowing the rod 30 to be inserted into the cylinder 20 while restricting its rotation. The cap 25 also contacts the piston 40 when the rod 30 is fully extended from the opening 22 of the cylinder 20, preventing the rod 30 from coming loose from the cylinder 20.

[0023] Next, the rod 30 will be described in detail. This rod 30 is movably inserted into the cylinder 20 through the opening 22 of the cylinder 20 and slides within the cylinder 20 in the axial direction of the cylinder 20.

[0024] As shown in Figure 1, the rod 30 in this embodiment has a long plate-shaped shaft portion 31 having a long axis and a short axis, similar to the wall portion 21 of the cylinder 20 and the piston 40. A rotating hole 32a is formed at one end 32 in the axial direction of the shaft portion 31, and a connecting shaft (not shown) of the other member described above is rotatably inserted into this rotating hole 32a, thereby rotatably connecting the rod 30 to the other member. The piston 40 is connected to the other end 33 in the axial direction of the shaft portion 31.

[0025] A through hole 34 is formed at the other end 33 of the shaft portion 31, penetrating in a direction intersecting the direction of movement of the piston 40 (the direction along the damper braking direction F1 and the damper return direction F2). The through hole 34 is positioned offset in a direction perpendicular to the axis C (see Figures 4 and 7) of the rod 30. Furthermore, flange-like side wall portions 35, 35 are provided on both sides of the shaft portion 31 in the direction of its long axis (also known as the width direction). In addition, protruding ridge portions 36 are provided on both sides of the shaft portion 31 in the thickness direction and in the center in the width direction.

[0026] Next, the piston 40 will be described in detail with reference to Figures 3 to 5, etc. The piston 40 has a rod connecting portion 42 to which the rod 30 is connected, a flange portion 43 formed on the opposite side of the rod connecting portion 42 and having a contact surface 44 to which the seal member 70 abuts, an axial groove 46 formed between the rod connecting portion 42 and the flange portion 43, communicating with the annular groove 45 and extending in the axial direction, and an orifice groove 50 that communicates with the axial groove 46 and is formed on the contact surface 44, having a bottom portion 51 and both sides 53, 53 and having a concave groove shape that extends toward the outer edge 43a of the flange portion 43.

[0027] The piston 40 has a body 41 having a long axis and a short axis, similar to the wall portion 21 of the cylinder 20. A rod connecting portion 42 protrudes from the outer circumference of one end of the body 41, and a flange portion 43 protrudes from the outer circumference of the other end of the body 41. The rod connecting portion 42 and the flange portion 43 are arranged parallel to each other, and both ends in the longitudinal direction are arc-shaped, with the outer edges along the longitudinal direction being parallel to each other, forming an annular flange shape.

[0028] The space enclosed by the main body 41, the rod connecting portion 42, and the flange portion 43 forms an annular groove 45 in which the seal ring 71 and friction member 75 constituting the seal member 70 are arranged. The surface of the flange portion 43 facing the rod connecting portion 42 forms a contact surface 44 that abuts against the friction member 75 constituting the seal member 70.

[0029] As shown in Figures 1, 3, and 4, an axial groove 46 is formed at a predetermined location on the outer circumference of the piston 40, extending along the axial direction of the piston 40. One end of this axial groove 46 is located at the rod connecting portion 42, and it cuts through the rod connecting portion 42 to communicate with the space on the outer surface of the rod connecting portion 42 (the surface opposite to the surface facing the flange portion 43). It also passes through the main body 41 and extends axially, with the other end of the groove extending to the contact surface 44 of the flange portion 43.

[0030] Furthermore, this axial groove 46 is formed at only one location on the outer circumference of the piston 40 (it is not formed on the surface opposite to the surface on which the axial groove 46 is formed). In addition, the axial groove 46 is positioned offset in a direction perpendicular to the axis of the piston 40 (a position aligned with the axis C of the rod 30) with respect to the direction along the axis of the piston 40.

[0031] Furthermore, an annular projection 47 is formed on the bottom surface of the annular groove 45 (which can also be called the outer circumferential surface of the main body 41), extending continuously in the circumferential direction of the main body 41 from a position closer to the flange portion 43.

[0032] As shown in Figures 3 and 4, the orifice groove 50 is formed on the contact surface 44 of the flange portion 43, at a position aligned with the circumferential direction of the piston 40 relative to the axial groove 46, and has a bottom portion 51 and two side surfaces 53, 53 located on both sides in the direction of its width (length along the circumferential direction of the piston 40, in this case the length along the long side of the main body 41), and is a concave groove shape extending toward the outer edge 43a of the flange portion 43. This orifice groove 50 is formed at only one location on the outer circumference of the piston 40, similar to the axial groove 46.

[0033] Furthermore, as described above, the orifice groove 50 is in communication with the axial groove 46, and when the piston 40 moves in the damper braking direction F1, as shown by arrow L1 in Figure 9, the air in the second air chamber V2 is circulated to the first air chamber V1 via the axial groove 46. This prevents the first air chamber V1 from becoming excessively negative pressure, which would prevent the piston 40 from moving in the damper braking direction F1, thereby adjusting the damper braking force.

[0034] Furthermore, the orifice groove 50 is configured such that both sides 53, 53 are inclined to gradually narrow towards the bottom 51, and the bottom 51 is a flat surface that intersects (in this case is perpendicular to) both sides 53, 53, and can also be said to be perpendicular to the axial direction of the piston 40, forming a roughly trapezoidal recessed groove when viewed from the side.

[0035] Furthermore, as shown in Figure 4, the orifice groove 50 is formed with an opening width W at the contact surface 44 that is larger than the depth D from the contact surface 44 to the bottom 51, so that the sealing member 70 can enter the orifice groove 50 when the piston 40 moves in the damper braking direction F1 (see Figures 10B and 10C).

[0036] The depth D refers to the maximum length from the contact surface 44 of the flange portion 43 to the bottom 51 (if the bottom is not a flat surface, it refers to the maximum length between the deepest point and the contact surface), and the opening width W refers to the maximum length of both sides 53, 53 of the orifice groove 50 at the contact surface 44 of the flange portion 43.

[0037] Incidentally, when the piston 40 moves in the damper braking direction F1, the seal member 70 comes into contact with and is supported by the contact surface 44 of the flange portion 43. At this time, as shown in Figures 10B and 10C, the seal member 70 is received by the receiving portions 44a, 44a located on the outer edges of both sides 53, 53 of the orifice groove 50 of the contact surface 44.

[0038] At this time, the portion of the sealing member 70 that is received by the receiving portions 44a, 44a of the contact surface 44 becomes a portion 70a (hereinafter also referred to as the "free deformation portion 70a") that can be freely deformed without deformation being restricted by the contact surface 44. In the present invention, as described above, the opening width W at the contact surface 44 of the orifice groove 50 is formed to be larger than the depth D from the contact surface 44 to the bottom portion 51, so that a longer free deformation portion 70a of the sealing member 70 can be secured, and the sealing member 70 can be inserted into the orifice groove 50.

[0039] If the opening width W is smaller than the depth D of the orifice groove 50, or if the depth D and opening width W are the same, the freely deformable portion 70a of the sealing member 70 will be extremely short compared to the case where the opening width W is larger than the depth D of the orifice groove 50. As a result, it will be difficult to sufficiently deform the freely deformable portion 70a, and it will be difficult for the sealing member 70 to enter the orifice groove 50.

[0040] Also, in the case of this damper device 10, when the moving speed of the piston 40 in the damper braking direction F1 is low, the seal member 70 does not enter the orifice groove 50 (see FIG. 10A) or the amount of entry of the seal member 70 into the orifice groove 50 is small (see FIG. 10B). On the other hand, when the moving speed of the piston 40 in the damper braking direction F1 is high, the amount of entry of the seal member 70 into the orifice groove 50 is configured to increase (see FIG. 10C).

[0041] That is, in this damper device 10, when the piston 40 moves in the damper braking direction F1, the amount of entry of the seal member 70 into the orifice groove 50 is configured to increase.

[0042] Further, as shown in FIG. 4, when the depth of the orifice groove 50 is “D” and the opening width of the orifice groove 50 is “W”, it is preferably set that D:W = 1:5 to 20, and more preferably set that D:W = 1:10 to 15.

[0043] Next, referring to FIGS. 1, 6, and 7, the seal ring 71 and the friction member 75 constituting the seal member 70 will be described in detail.

[0044] This seal ring 71 is formed of an elastic material such as rubber or elastomer and is bendable and deformable. It has inner diameter side protrusions 72, 72 protruding from both axial ends on its inner peripheral surface, and an outer diameter side protrusion 73 protruding from the central position in the axial direction on its outer peripheral surface and pressing against the inner peripheral surface of the cylinder 20.

[0045] On the other hand, the friction member 75 is formed of an elastic material such as rubber or elastomer and is bendable and deformable, and has an annular shape conforming to the outer peripheral shape of the annular groove 45. An annular mounting groove 76 is formed on the inner periphery of the friction member 75. By inserting the protrusion 47 of the piston 40 into this mounting groove 76, the friction member 75 is mounted on the annular groove 45. Further, the other end in the axial direction of the friction member 75 has a contact surface 77 that can make surface contact with the contact surface 44 of the flange portion 43 of the piston 40.

[0046] Furthermore, ventilation grooves 78 extending along the axial direction are formed on the outer peripheral surface of the friction member 75. When the piston 40 moves in the damper braking direction F1, the ventilation grooves 78 are pressed by the seal ring 71, and the air permeability is maintained even when the outer peripheral surface of the friction member 75 is in pressure contact with the inner peripheral surface of the cylinder 20.

[0047] Next, the operations of the seal ring 71 and the friction member 75 in 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 will be described.

[0048] FIG. 7 shows the state where the piston 40 is stationary. In this state, the seal ring 71 has its outer diameter side protrusion 73 in pressure contact with the inner peripheral surface of the cylinder 20, and its inner diameter side protrusions 72, 72 abut against the bottom surface of the annular groove 45 and the other end in the axial direction is separated from one end in the axial direction of the friction member 75, forming a gap. This gap communicates with each other between the first air chamber V1 and the second air chamber V2 via the annular groove 45 and the axial groove 46.

[0049] The seal ring 71 is disposed in the cylinder 20 in a deformed state from the free state shown in FIG. 6. On the other hand, in this state, since the pressing force from the seal ring 71 does not act on the friction member 75, the friction member 75 does not expand in diameter, and its outer peripheral surface is not in contact with the inner peripheral surface of the cylinder 20 and is separated therefrom.

[0050] When the piston 40 starts to move in the damper braking direction F1, a frictional force (frictional force in the damper return direction F2) in the direction opposite to the damper braking direction F1 acts on the outer diameter side protrusion 73 from the inner peripheral surface of the cylinder 20. As a result, the seal ring 71 is pushed toward the damper return direction F2 by the frictional force. As a result, as shown in FIGS. 8 and 9, the other end in the axial direction of the seal ring 71 abuts against one end in the axial direction of the friction member 75.

[0051] As a result, the gap between the other axial end of the seal ring 71 and one end of the friction member 75 disappears, and the air flow between the first air chamber V1 and the second air chamber V2 through this gap, the annular groove 45, and the axial groove 46 is obstructed. This causes the pressure in the first air chamber V1 inside the cylinder 20 to decrease, and the damper braking force is exerted. Even in this state, the first air chamber V1 and the second air chamber V2 are in communication with each other via the orifice groove 50 and the axial groove 46 (see arrow L1 in Figure 9), preventing the first air chamber V1 from becoming a vacuum and ensuring that the piston 40 moves in the damper braking direction F1.

[0052] Subsequently, when the piston 40 moves a predetermined distance in the damper braking direction F1, the frictional force in the damper return direction F2 from the inner circumferential surface of the cylinder 20 pushes the seal ring 71 further toward the damper return direction F2. At the same time, as the piston 40 moves toward the damper braking direction F1, the pressure in the first air chamber V1 is further reduced, and the suction force from the first air chamber V1 acts on the seal ring 71 through the ventilation groove 78 of the friction member 75, causing the seal ring 71 to move further toward the damper return direction F2.

[0053] As a result, as shown in Figure 9, the other axial end of the seal ring 71 presses against the one axial end of the friction member 75, causing it to move over the protrusion 47, expanding the diameter of the friction member 75, and pressing its outer surface against the inner surface of the cylinder 20, thereby generating a frictional force of the friction member 75 against the inner surface of the cylinder 20. In other words, this damper device 10 generates a damper braking force consisting of the resistance due to the pressure change in the first air chamber V1, the frictional force of the seal ring 71 against the inner surface of the cylinder 20, and the frictional force of the friction member 75 against the inner surface of the cylinder 20.

[0054] Furthermore, when the load acting on the piston 40 is small, the pressing force of the other axial end of the seal ring 71 against one axial end of the friction member 75 is low, so the contact force of the friction member 75 against the inner circumferential surface of the cylinder 20 is small, and the damper braking force is small. As a result, the speed at which the piston 40 moves in the damper braking direction F1 is fast. On the other hand, when the load acting on the piston 40 is large, the pressing force of the other axial end of the seal ring 71 against one axial end of the friction member 75 is high, so the contact force of the friction member 75 against the inner circumferential surface of the cylinder 20 is large, and the damper braking force is large. As a result, the speed at which the piston 40 moves in the damper braking direction F1 is slow.

[0055] On the other hand, as shown in Figure 11, when the piston 40 moves in the damper return direction F2, a frictional force opposite to the damper return direction F2 acts on the outer diameter side projection 73 of the seal ring 71 from the inner circumferential surface of the cylinder 20, pushing the seal ring 71 toward the damper braking direction F1. As a result, one axial end of the seal ring 71 comes into contact with the inner surface of the annular groove 45 on the axial end side, and the other axial end of the seal ring 71 moves away from the axial end of the friction member 75.

[0056] As a result, the friction member 75 elastically returns to its original shape, and the pressure force acting on the inner circumferential surface of the cylinder 20 ceases, and a gap is created again between the other axial end of the seal ring 71 and the one axial end of the friction member 75. As a result, as shown by arrow L2 in Figure 12, the air in the first air chamber V1 inside the cylinder 20 flows out into the second air chamber V2, passing sequentially through the annular groove 45, the gap, and the axial groove 46. Consequently, the damper braking force is released.

[0057] (Modification) The shape, structure, and layout of the cylinder, rod, piston, cap, seal ring, friction member, orifice groove, etc., that constitute the damper device in the present invention are not limited to the above embodiments.

[0058] In this embodiment, the wall portion 21 of the cylinder 20 is thin and cylindrical, but the cylinder wall portion may be, for example, a roughly elliptical cylinder, or any shape having a major axis and a minor axis. Furthermore, it is preferable that the rod, piston, cap, etc., have a shape corresponding to the cylinder wall portion.

[0059] Furthermore, although the cylinder 20 in this embodiment has an end wall 23 positioned on the other end in the axial direction to close it, for example, a through hole may be formed in the end wall positioned on the other end of the cylinder, and this through hole may be opened and closed with a seal cap.

[0060] Furthermore, although the orifice groove 50 in this embodiment has a generally trapezoidal shape consisting of a pair of inclined side surfaces 53, 53 and a flat bottom surface 51, for example, the side surfaces may be convex, concave, multiple inclined surfaces at different angles, stepped, etc., or the bottom surface may be concave, convex, roughly V-shaped, roughly U-shaped, etc.

[0061] Furthermore, the inner shape of the orifice groove, including the bottom and both sides, may be approximately U-shaped, V-shaped, or U-shaped overall. Additionally, a recess of a predetermined depth may be provided at the bottom of the orifice groove (this will be explained in other embodiments described later).

[0062] Furthermore, although the sealing member 70 in this embodiment consists of a sealing ring 71 and a friction member 75, it may also consist of, for example, only a sealing ring.

[0063] In this embodiment, when the piston 40 moves away from the end wall 23 of the cylinder 20 (when the piston 40 moves in the damper braking direction F1), a braking force is applied due to the depressurization of the first air chamber V1, and when the piston 40 moves closer to the end wall 23 of the cylinder 20 (when the piston 40 moves in the damper return direction F2), the above braking force is released. However, conversely, the damper braking force may be applied when the piston moves closer to the end wall of the cylinder, and the damper braking force may be released when the piston moves away from the end wall of the cylinder.

[0064] Furthermore, in this embodiment, one member is a fixed body such as an instrument panel housing, 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 closer to and further away from each other.

[0065] (Effects) Next, the effects of the damper device 10 having the above configuration will be explained.

[0066] In this damper device 10, when one component (such as a fixed body) and the other component (such as an opening / closing body) are in close proximity to each other, the piston 40 remains stationary within the cylinder 20 (see Figure 7). In this state, the friction member 75 constituting the seal member 70 does not enter the orifice groove 50 (see Figure 10A).

[0067] From this state, when one member moves away from the other member (when the opening / closing body opens from the fixed body), as shown in Figure 7, the piston 40 moves in the damper braking direction F1, and the pressure in the first air chamber V1 inside the cylinder 20 is reduced, so that a damper braking force is applied to the piston 40. Also, as shown in Figures 10B and 10C, a part of the friction member 75 that constitutes the seal member 70 (the freely deformable portion 70a of the seal member 70) enters the orifice groove 50 by a predetermined amount (this will be described in detail later).

[0068] Furthermore, when the piston 40 moves a predetermined distance in the damper braking direction F1, the suction force from the first air chamber V1 acts on the seal ring 71 in accordance with the pressure change in the air chamber, causing the seal ring 71 to move in the damper return direction F2. This causes the seal ring 71 to press against the friction member 75, expanding its diameter and bringing it into contact with the inner circumferential surface of the cylinder 20, thereby generating a frictional force on the friction member 75 against the inner circumferential surface of the cylinder 20.

[0069] As a result, a damper braking force is exerted, consisting of the resistance due to the pressure change in the first air chamber V1, the frictional force of the seal ring 71 against the inner circumferential surface of the cylinder 20, and the frictional force of the friction member 75 against the inner circumferential surface of the cylinder 20. This allows one member to move slowly relative to the other (allowing the opening / closing body to be opened slowly from the fixed body).

[0070] In this damper device 10, as shown in Figure 4, the orifice groove 50 is formed with an opening width W at the contact surface 44 that is larger than the depth D from the contact surface 44 to the bottom 51, so that the sealing member 70 can enter the orifice groove 50 when the piston 40 moves in the damper braking direction F1 (see Figures 10B and 10C).

[0071] Therefore, when one member approaches or moves away from the other member, if the load acting on the other member is small and the load acting on the piston 40 is small (in this embodiment, this can also be said to be when the load pulling the piston 40 in the damper braking direction F1 is small), the sealing member 70 will not enter the orifice groove 50 (see Figure 10A) or the amount of the sealing member 70 entering the orifice groove 50 will be small (see Figure 10B).

[0072] Therefore, compared to the case where the amount of sealing member 70 inserted into the orifice groove 50 is large, the air in the second air chamber V2 flows more easily to the first air chamber V1, so the damper braking force is reduced. As a result, the speed at which the piston 40 moves in the damper braking direction F1 becomes faster.

[0073] On the other hand, when one member approaches or moves away from the other member, if the load acting on the other member is large and the load acting on the piston 40 is large (in this embodiment, this can also be said to be when the load pulling the piston 40 in the damper braking direction F1 is large), the amount that the sealing member 70 penetrates into the orifice groove 50 increases (see Figure 10C).

[0074] Therefore, compared to the case where the amount of sealing member 70 entering the orifice groove 50 is zero or small, the air in the second air chamber V2 has difficulty circulating to the first air chamber V1, so the damper braking force increases. As a result, the speed at which the piston 40 moves in the damper braking direction F1 slows down.

[0075] In other words, the damper device 10 has an orifice groove 50 in which the opening width W at the contact surface 44 is larger than the depth D from the contact surface 44 to the bottom 51. This makes it easier to insert the sealing member 70 into the orifice groove 50, thereby making it easier to adjust the amount that the sealing member 70 enters the orifice groove 50 in response to changes in the load acting on the piston 40.

[0076] Therefore, when the tensile load on the piston 40 is small, the internal space of the orifice groove 50 (the air passage through which air flows) is made larger, increasing the amount of air flowing through the orifice groove 50, thereby increasing the damper braking force and increasing the speed at which the piston 40 moves in the damper braking direction F1. On the other hand, when the tensile load on the piston 40 is large, the internal space of the orifice groove 50 is narrowed, reducing the amount of air flowing through the orifice groove 50, decreasing the damper braking force and slowing down the speed at which the piston 40 moves in the damper braking direction F1.

[0077] Therefore, by appropriately changing the size of the internal space of the orifice groove 50 in accordance with the load acting on the piston 40, the amount of air flowing through the orifice groove 50 can be increased or decreased, thereby changing the damper braking force. As a result, a structure that changes the speed at which the piston 40 moves in the damper braking direction F1 in accordance with the load acting on the piston 40 can be realized with the above configuration of the orifice groove 50.

[0078] Furthermore, in this damper device 10, the size of the internal space of the orifice groove 50 is appropriately changed in accordance with the load acting on the piston 40, and the pressure force of the friction member 75 against the inner circumferential surface of the cylinder 20 is also appropriately changed. This makes it easier to change the damper braking force in accordance with the load acting on the piston 40.

[0079] Furthermore, in this damper device 10, by forming the orifice groove 50 on the contact surface 44 of the flange portion 43, it is possible to prevent it from affecting the axial movement of the seal member 70. In other words, if the orifice groove were formed on the outer circumference of the main body 41 of the piston 40, when the seal member 70 moves in the axial direction of the piston 40, the inner circumference of the seal member 70 may get stuck in the orifice groove, making it difficult for the seal member 70 to move. However, this situation does not occur in this damper device 10.

[0080] Furthermore, in this embodiment, both sides 53, 53 of the orifice groove 50 are formed to be inclined so as to gradually narrow towards the bottom 51.

[0081] According to the above embodiment, since both sides 53, 53 of the orifice groove 50 have the above configuration, the sealing member 70 can easily enter the orifice groove 50 when the piston 40 moves in the damper braking direction F1, and the damper braking force can be changed quickly in accordance with the magnitude of the load acting on the piston 40 (response can be improved).

[0082] Furthermore, the internal space of the orifice groove 50 can be efficiently reduced in proportion to the amount the sealing member 70 penetrates into the orifice groove 50, and a change in damper braking force can be reliably produced in accordance with the magnitude of the load acting on the piston 40.

[0083] Furthermore, in this embodiment, the bottom 51 of the orifice groove 50 has a flat surface shape that intersects with both side surfaces 53, 53.

[0084] According to the above embodiment, since the bottom 51 of the orifice groove 50 has the above configuration, even when the load acting on the piston 40 is large and the amount of the sealing member 70 entering the orifice groove 50 is large, a gap G can be formed between the bottom 51 and the boundary portion K (corner portion) of both sides 53, 53 of the orifice groove 50 and the sealing member 70, as shown in Figure 10C. As a result, the internal space of the orifice groove 50 is prevented from being completely blocked by the sealing member 70, so that air circulation through the orifice groove 50 is ensured and the movement of the piston 40 is prevented from being obstructed.

[0085] Furthermore, in this embodiment, when the depth of the orifice groove 50 is D and the opening width of the orifice groove 50 is W, the ratio D:W is set to 1:5 to 20.

[0086] According to the above embodiment, since the depth D of the orifice groove 50 and the opening width W of the orifice groove 50 are in the above relationship, the sealing member 70 can enter the orifice groove 50 more easily when the piston 40 moves in the damper braking direction F1, and the damper braking force can be changed more reliably in accordance with the magnitude of the load acting on the piston 40.

[0087] Furthermore, in this embodiment, the sealing member 70 has a contact surface 77 that can make surface contact with the contact surface 44 of the flange portion 43. Here, the contact surface 77 is provided at the other axial end of the friction member 75 that constitutes the sealing member 70.

[0088] According to the above embodiment, since the seal member 70 has a contact surface 77 that can make surface contact with the abutment surface 44 of the flange portion 43, when the piston 40 moves in the damper braking direction F1, as shown in Figures 8 and 9, the contact surface 77 of the seal member 70 makes surface contact with the abutment surface 44 of the flange portion 43, and the frictional force holds the seal member 70 in place so that it does not move. At the same time, the seal member 70 becomes more easily deformed starting from the part that is in surface contact, so that the seal member 70 can enter the orifice groove 50 more easily.

[0089] (Other Embodiments of the Damper Device) Figures 13 and 14 show other embodiments of the damper device according to the present invention. Parts substantially identical to those in the above embodiments are denoted by the same reference numerals and their descriptions are omitted.

[0090] The damper device of this embodiment differs from the previous embodiment in the structure of the orifice groove 50A. Specifically, as shown in Figures 13 and 14, a recess 55 is formed at the bottom 51 of the orifice groove 50A, which communicates with the internal space of the orifice groove 50A, and the recess 55 is formed to be narrower than the width of the bottom 51.

[0091] More specifically, this recess 55 is formed in the center of the width direction of the bottom portion 51, and has a rectangular groove shape that is open at the top and extends toward the outer edge 43a of the flange portion 43 (it can also be described as an upward-facing, roughly U-shaped groove).

[0092] Furthermore, according to the above embodiment, even if the sealing member 70 enters the orifice groove 50A and fills the internal space of the orifice groove 50A other than the recess 55 when the piston 40 moves in the damper braking direction F1, the recess 55 can reliably secure the air passage of the orifice groove 50, thereby preventing it from hindering the movement of the piston 40.

[0093] It should be noted that the present invention is not limited to the embodiments described above, 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.

[0094] 10... Damper device, 20... Cylinder, 25... Cap, 30... Rod, 40... Piston, 42... Rod connecting part, 43... Flange part, 44... Contact surface, 45... Annular groove, 46... Axial groove, 50, 50A... Orifice groove, 51... Bottom part, 53, 53... Both sides, 55... Recess, 70... Seal member, 71... Seal ring, 75... Friction member.

Claims

1. A damper device installed between a pair of members that move closer to or further away from each other, which applies a braking force when the pair of members move closer to or further away from each other, comprising: a cylinder with an opening at one end; a rod inserted into the cylinder; a piston connected to the rod and having an annular groove formed on its outer circumference; and a seal member disposed axially movable within the annular groove, wherein the piston comprises: a rod connecting portion to which the rod is connected; a flange portion formed on the opposite side of the rod connecting portion and having a contact surface against which the seal member abuts; an axial groove formed between the flange portion and the rod connecting portion, communicating with the annular groove and extending axially; and an orifice groove communicating with the axial groove and formed on the contact surface, having a bottom and both sides and being concave groove-shaped, extending toward the outer edge of the flange portion. The damper device is characterized in that the orifice groove has an opening width at the contact surface that is larger than the depth from the contact surface to the bottom, and the sealing member can enter the orifice groove when the piston moves in the damper braking direction.

2. The damper device according to claim 1, wherein both sides of the orifice groove are formed to be inclined so as to gradually narrow towards the bottom.

3. The damper device according to claim 2, wherein the bottom of the orifice groove has a flat surface shape that intersects with the two sides.

4. A damper device according to any one of claims 1 to 3, wherein when the depth of the orifice groove is D and the opening width of the orifice groove is W, D:W = 1:5 to 20.

5. The damper device according to any one of claims 1 to 3, wherein the sealing member has a contact surface that can make surface contact with the contact surface of the flange portion.

6. The damper device according to any one of claims 1 to 3, wherein a recess is further formed at the bottom of the orifice groove, and the recess is formed to be narrower than the width of the bottom.

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