Damper device

Abstract

Provided is a damper device which can restrict the swinging of a rod in the width direction and thickness direction thereof with a simple structure. This damper device 10 has a cylinder 20, a piston rod 30, and a guide cap 70, and the piston rod 30 has a rod 40 and a piston 60. The rod 40 is of a plate shape. The guide cap 70 has an insertion wall part 71 inserted inside an opening 23 of the cylinder 20, an insertion hole 73 into which the rod 40 is inserted, and an elastic piece 77 that is elastically deformable. A convex curved surface 80 and a concave curved surface 50 are formed between the rod 40 and the elastic piece 77, and the concave curved surface 50 provided to the rod 40 extends in the axial direction and is configured to guide the axial direction movement of the piston rod 30.

Description

Technical Field

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

Background Art

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

[0003] Such a damper device usually has a cylinder and a piston rod composed of a rod and a piston that move within the cylinder. Also, although the rod may be plate-shaped, in this case, when the piston rod moves within the cylinder, the rod may wobble in the width direction or the thickness direction.

[0004] In order to regulate such "wobbling", Patent Document 1 below has a cylinder and a rod that is inserted into the cylinder and whose moving speed is regulated, and has a through hole formed in the cylinder that allows the rod to enter and exit the cylinder in a non-contact state, and an elastic member provided at the edge of the through hole that maintains a contact state with the rod. An air damper is described.

[0005] The through hole is in the shape of a long hole, and three thin plate-shaped elastic tongue pieces are respectively erected from the peripheral edges of both ends in the longitudinal direction thereof. That is, a pair of elastic tongue pieces are arranged facing the longitudinal direction of the through hole, and a pair of elastic tongue pieces are respectively arranged facing each other at both ends in the longitudinal direction of the through hole and at positions orthogonal to the longitudinal direction. A total of six elastic tongue pieces are provided. And the wobbling of the rod in the longitudinal direction of the through hole is regulated by a pair of elastic tongue pieces arranged facing the longitudinal direction of the through hole, and the wobbling of the rod in the direction orthogonal to the longitudinal direction of the through hole is regulated by a pair of elastic tongue pieces arranged orthogonally to the longitudinal direction at both ends in the longitudinal direction of the through hole (see paragraph 0016 of Patent Document 1).

Prior Art Documents

Patent Document

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In the case of the air damper of the above Patent Document 1, since six elastic tongue pieces are provided at the peripheries of both longitudinal ends of the through hole, the structure is complicated.

[0008] Therefore, an object of the present invention is to provide a damper device that can regulate the displacement of a rod in the width direction and the thickness direction with a simple structure.

Means for Solving the Problems

[0009] In order to achieve the above object, the present invention is a damper device that is attached between a pair of members that approach and separate from each other, and applies a braking force when the pair of members approach or separate. It has a cylinder provided with an opening at one end, a piston rod movably inserted into the cylinder through the opening, and a guide cap attached to the opening of the cylinder. The piston rod has a rod and a piston connected to the rod. The cylinder has a cylindrical wall portion, and a cross section of the wall portion perpendicular to the moving direction of the piston has a shape with a major axis and a minor axis. The piston has a shape with a major axis and a minor axis so as to fit the inner circumference of the wall portion of the cylinder. The rod has a major axis along the major axis direction of the piston and a minor axis perpendicular thereto when viewed from the axial direction, and has a plate shape extending a predetermined length. The guide cap has an insertion wall portion inserted inside the opening of the cylinder, an insertion hole into which the rod is inserted, and an elastically deformable elastic piece portion provided at a portion of the insertion wall portion facing the rod. A convex portion is formed on one of the rod or the elastic piece portion, and a concave portion into which the convex portion enters and abuts is formed on the other. The convex portion or the concave portion provided on the rod extends in the axial direction and is configured to guide the axial movement of the piston rod. At least one of the convex portion side or the concave portion side of the contact portion between the convex portion and the concave portion has a curved surface.

Effect of the Invention

[0010] In the present invention, the axial movement of the piston rod is configured to be guided by the convex portion and the concave portion into which the convex portion enters and abuts. Therefore, it is possible to regulate the play in the thickness direction and width direction of the rod during the movement of the piston rod in the cylinder with a simple structure.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0012] (First Embodiment of the Damper Device) Hereinafter, with reference to the drawings, the first embodiment of the damper device according to the present invention will be described.

[0013] The damper device 10 shown in FIGS. 1 and 2 is attached to a pair of members that approach and separate from each other, and applies a braking force when the pair of members approach or separate. For example, it can be used for braking, such as a glove box or a lid that is openably attached to an opening of a storage portion provided in an instrument panel of an automobile. In the following embodiments, one member will be described as a fixed body such as a storage portion of an instrument panel, and the other member will be described as an opening / closing body such as a glove box or a lid that is openably attached to an opening of the fixed body.

[0014] As shown in FIG. 1, the damper device 10 of this embodiment includes a cylinder 20 provided with an opening 23 at one end, a piston rod 30 movably inserted into the cylinder 20, and a guide cap 70 attached to the opening 23 of the cylinder 20. The piston rod 30 has a rod 40 and a piston 60 connected to the other end 42 side in the axial direction of the rod 40. The rod 40 and the piston 60 are configured to move within the cylinder 20 as the piston rod 30 moves.

[0015] Furthermore, between the rod 40 and the elastic piece portion 77 of the guide cap 70, a convex portion is formed on one of the rod 40 or the elastic piece portion 77, and a concave portion into which the convex portion enters and abuts is formed on the other. The convex portion or the concave portion provided on the rod 40 extends in the axial direction and is configured to guide the axial movement of the piston rod 30. Also, at least one of the convex portion side or the concave portion side of the contact portion between the convex portion and the concave portion forms a curved surface.

[0016] Furthermore, in this embodiment, the convex portion has a convex curved surface that forms the curved surface, and the concave portion has a concave curved surface that forms the curved surface, and the convex curved surface and the concave curved surface are in contact with each other.

[0017] In this embodiment, as shown in FIG. 7, a recess is formed on the rod 40 side, and a curved concave surface 50 is provided in the recess. This concave surface 50 extends in the axial direction, while a protrusion 79 is formed on the guide cap 70 side, and a curved convex surface 80 is provided in the protrusion 79.

[0018] Furthermore, in this damper device 10, with the piston rod 30 inserted into the cylinder 20 and the guide cap 70 attached to the opening 23 of the cylinder 20, the convex curved surface and the concave curved surface are configured to be in constant contact with each other, either by the concave curved surface pressing against the convex curved surface to elastically deform the elastic piece portion 77, or by the convex curved surface pressing against the concave curved surface to elastically deform the elastic piece portion 77. In this embodiment, as shown in Fig. 12, the concave curved surface 50 presses against the convex curved surface 80 to elastically deform the elastic piece portion 77, so that the convex curved surface 80 and the concave curved surface 50 are configured to be in constant contact with each other.

[0019] Furthermore, a seal ring 69 is attached to the outer periphery of the piston 60, and an air chamber is formed within the cylinder 20 via this seal ring 69 (seal portion). In this embodiment, the air chamber is formed within the cylinder 20 on the side of the seal portion in the insertion direction of the piston rod 30. That is, as shown in FIG. 3, when the piston 60 is inserted into the cylinder 20, the seal ring 69 is pressed against the inner circumferential surface of the cylinder 20. As a result, a first air chamber V1 is formed on the side of the cylinder 20 in the insertion direction of the rod 40, with the seal ring 69 as the boundary, and a second air chamber V2 is formed on the side of the opening 23 of the cylinder 20. Note that, in this embodiment, the inner circumferential surface of the cylinder 20 refers to the inner circumferential surface of the wall portion 21 (see FIG. 6, etc.) that constitutes the cylinder 20, and this also applies in the following description.

[0020] In the following description, "one end portion" or "one end" means one end portion or one end on the damper braking direction side of the damper device 10, and "the other end portion" or "the other end" means the other end portion or the other end on the return direction side opposite to the damper braking direction. Further, the "damper braking direction" in this embodiment means the direction in which the piston 60 moves away from the end wall 25 (see FIG. 3) of the cylinder 20 and the drawing amount of the rod 40 from the opening 23 of the cylinder 20 increases (see the arrow F1 in FIG. 3). Also, the "return direction opposite to the damper braking direction" (hereinafter, also simply referred to as the "damper return direction") in this embodiment means the direction in which the piston 60 approaches the end wall 25 of the cylinder 20 and the pushing amount of the rod 40 into the cylinder 20 increases (see the arrow F2 in FIG. 3).

[0021] As shown in FIG. 1, the cylinder 20 has a wall portion 21 extending in a cylindrical shape. Referring also to FIG. 6, this wall portion 21 has an annular cross-section (which can also be said to be a cross-section orthogonal to the axial direction of the cylinder 20) orthogonal to the moving direction of the piston 60 (the direction along the damper braking direction F1 and the damper return direction F2), having a major axis A and a minor axis B, and is in the shape of a thin cylindrical shape (a cylindrical shape presenting a thin box shape) with the major axis A side being wide and the minor axis B side being narrow. More specifically, the wall portion 21 in this embodiment linearly extends in the direction along the major axis A, and has a pair of major axis wall portions 21a, 21a arranged to face each other in parallel, and a pair of minor axis wall portions 21b, 21b arranged on the minor axis B side, having an arcuate bent shape and connecting both ends of the major axis wall portions 21a, 21a to each other.

[0022] Note that the direction along the major axis A of the cylinder 20 can also be said to be the "width direction", and the direction along the minor axis B orthogonal to the major axis A of the cylinder 20 can also be said to be the "thickness direction". The meanings of these "width direction" and "thickness direction" are the same for each member such as the piston rod 30, the rod 40 and the piston 60 constituting the piston rod 30, and the guide cap 70, which will be described below. It can also be said that the cylinder 20 has a flat cylindrical shape with its width direction being larger than its thickness direction.

[0023] Further, corresponding to the shape of the above-described wall portion 21, the piston 60 also has a shape having a major axis A and a minor axis B that fit within the inner circumference of the wall portion 21 of the cylinder 20 (this will be described in detail later).

[0024] One axial end portion side of the wall portion 21 of the cylinder 20 is open, and an opening 23 is provided. Also, engaging holes 23a, 23a are respectively formed in the opposed long axis wall portions 21a, 21a that are the peripheral edges of the opening 23. Here, a total of four engaging holes 23a are formed. Further, as shown in FIG. 3, an end wall 25 is disposed at the other axial end portion of the wall portion 21, and the other end portion of the wall portion 21 is closed.

[0025] Also, a rotation support piece 27 having a rotation hole 27a formed therein projects from the outer surface of the end wall 25 and the outer circumference of the wall portion 21 from one axial end portion. A rotation shaft (not shown) of the above-described one member is rotatably inserted into a predetermined rotation hole 27a, and the outer circumference of the cylinder 20 is rotatably connected to the one member.

[0026] Next, the rod 40 will be described with reference to FIGS. 4 to 7, FIGS. 11 and 12, etc.

[0027] This rod 40 is movably inserted into the cylinder 20 through the opening 23 of the cylinder 20, and slides in the axial direction of the cylinder 20 within the cylinder 20.

[0028] As shown in FIGS. 1 and 4, the rod 40 of this embodiment extends with a predetermined length, a rotation hole 41a is formed at one axial end portion 41 thereof, and a piston 60 is connected to the other axial end portion 42. Note that the axial direction of the rod 40 means the direction along the axis C1 (see FIG. 4) of the rod 40. Also, a connecting shaft (not shown) of the above-described other member is rotatably inserted into the rotation hole 41a formed at the one end portion 41, and the rod 40 is rotatably connected to the other member.

[0029] As shown in FIG. 6, the rod 40 has a cross-sectional shape having a major axis A and a minor axis B, similar to the wall portion 21 of the cylinder 20 and the piston 60. That is, when the piston 60 is viewed in the axial direction, the rod 40 has a plate-like shape with a cross-section that is long in the direction of the major axis A of the piston 60.

[0030] Further, the rod 40 has a shaft portion 43 having a long plate-like shape extending a predetermined length. A through-hole 44 having a substantially square-hole shape is formed through the rod 40 in the thickness direction at the other end portion 42 in the axial direction of the rod 40.

[0031] Ribs 45 are provided on both sides of the surfaces 43a, 43a of the rod 40 along the major axis A, standing upright in a direction orthogonal to the surfaces 43a along the major axis A and extending in the axial direction. That is, as shown in FIG. 6, the surfaces 43a, 43b (both surfaces 43a, 43b in the thickness direction) of the shaft portion 43 of the rod 40 along the major axis A, from both side portions in the direction of the major axis A (width direction), ribs 45 are respectively erected (projecting) toward the minor axis B direction (thickness direction) so as to be orthogonal to the surfaces 43a along the major axis A, and the ribs 45 extend along the axial direction of the rod 40. Here, a pair of ribs 45, 45 are provided in the width direction on one surface in the thickness direction of the rod 40, and a pair of ribs 45, 45 are also provided in the width direction on the other surface in the thickness direction, and a total of four ribs 45 are provided. As a result, the rod 40 has a substantially H-shaped cross-sectional shape when viewed in the axial direction.

[0032] Also, a standing portion 45a that stands higher than the other portions is provided at the portion of the rib 45 located on the piston 60 side (see FIG. 5), and the standing portion 45a is configured to be able to contact the inner peripheral surfaces of both end portions of the insertion hole 73 of the guide cap 70 (see FIG. 13).

[0033] In this embodiment, at the connecting portion of each rib 45 with the piston 60, that is, at the other end portion in the axial direction, there is provided an erected portion 45a erected higher than other portions. When the piston rod 30 is pulled maximally from the cylinder 20, that is, when the piston 60 moves so as to be farthest from the end wall 25 of the cylinder 20 as shown in FIG. 13 and the drawing amount of the rod 40 from the opening 23 of the cylinder 20 becomes maximum, the erected portion 45a of the rib 45 abuts against the inner peripheral surfaces at both ends of the insertion hole 73 formed in the insertion wall portion 71 of the guide cap 70. Specifically, the erected portions 45a, 45a of the rib 45 are oppositely arranged on the inner peripheral surfaces at both ends in the major axis A direction of the insertion hole 73, that is, on the inner peripheral surfaces of both side portions 74b, 74b (see FIGS. 8 and 9) in the width direction of the major axis wall portion 74 constituting the insertion wall portion 71, and can abut against the inner peripheral surfaces.

[0034] Furthermore, as shown in FIG. 11, the rod 40 is arranged to face a pair of cap-side guide portions 78, 78 provided on the guide cap 70, and has a pair of rod-side guide portions 47, 47 extending in the axial direction and a ridge portion 48 protruding toward the guide cap 70 side from the protruding surfaces of the pair of rod-side guide portions 47, 47 and entering between the pair of cap-side guide portions 78, 78 and extending in the axial direction. A concave curved surface 50 is provided on the ridge portion 48.

[0035] Specifically, on each surface 43a, 43b in the thickness direction of the shaft portion 43, that is, from positions inside the width direction of a pair of ribs 45, 45 located on both sides in the width direction, a pair of rod-side guide portions 47, 47 forming ridges extend along the axial direction of the rod 40. Here, a total of four rod-side guide portions 47 are provided in pairs on both surfaces 43a, 43b in the thickness direction of the shaft portion 43. Each rod-side guide portion 47 has a flat surface as its protruding surface (the tip surface in the protruding direction) and is arranged to face the cap-side guide portion 78 provided on the guide cap 70 so as to guide the axial movement of the piston rod 30.

[0036] Further, at the central portion in the width direction of the shaft portion 43 and on both surfaces 43a and 43b in the thickness direction, ridge portions 48 each forming a ridge extending along the axial direction are respectively provided in a protruding manner. Each ridge portion 48 has a protruding surface (the end surface in the protruding direction and facing the inner peripheral surface of the cylinder 20) protruding higher toward the guide cap 70 side than the protruding surfaces of the pair of rod side guide portions 47, 47. On this protruding surface, a rod side concave groove 49 extending along the axial direction of the rod 40 and forming the "recess" in the present invention is formed. As shown in FIGS. 1 and 3, this rod side concave groove 49 is formed over the entire axial length of the ridge portion 48.

[0037] And on the inner surface of this rod side concave groove 49 (the surface facing the inner peripheral surface of the cylinder 20 and the inner peripheral surface of the insertion wall portion 71 of the guide cap 70), a concave curved surface 50 is formed. Further, the concave curved surface 50 extends in the axial direction of the rod 40. The convex curved surface 80 provided on the guide cap 70 enters and abuts against and slidably contacts this concave curved surface 50, and the axial movement of the piston rod 30 is guided (this will be described in detail in the description of the convex curved surface 80).

[0038] As shown in FIG. 12 etc., the concave curved surface 50 in this embodiment is recessed toward the axis C1 of the rod 40 while depicting an R-shaped curved surface (recessed in a direction away from the inner peripheral surface of the cylinder 20 and the inner peripheral surface of the insertion wall portion 71 of the guide cap 70), forming a concave R-shaped curved surface. Further, the concave curved surface 50 extends over the entire axial length of the rod side concave groove 49 (see FIGS. 1 and 3). Incidentally, the radius of curvature of the concave curved surface 50 with respect to the axis C1 of the rod 40 is designated as "R1" (see FIG. 12).

[0039] Also, between each rib 45 and the rod side guide portion 47 on the surfaces of the rod 40 along the major axis A, that is, on both surfaces 43a and 43b in the thickness direction of the shaft portion 43, grooves 51 extending along the axial direction are formed (see FIGS. 4 and 11). Here, on both surfaces 43a and 43b in the thickness direction of the shaft portion 43, one groove 51 is provided on each of the both sides in the width direction, for a total of four grooves 51.

[0040] Next, the piston 60 will be described.

[0041] As shown in FIGS. 1 and 3, the piston 60 of this embodiment is connected to the other end portion 42 in the longitudinal direction of the rod 40, and an annular groove 64 is formed on its outer periphery, and it is integrally formed with the rod 40.

[0042] An annular seal ring 69 made of an elastic material such as rubber or elastomer is mounted in the annular groove 64. Further, the seal ring 69 is constantly pressed against the inner peripheral surface of the cylinder 20. Note that "constantly" means all states that the piston 60 can take in the cylinder 20, such as a state where the piston 60 is stationary, a state where the piston 60 moves in the damper braking direction F1, and a state where the piston 60 moves in the damper return direction F2 (the same meaning also applies in the relationship between the convex curved surface 80 and the concave curved surface 50).

[0043] As shown in FIGS. 3 and 5, the piston 60 includes a first side wall portion 61 and a second side wall portion 62 that are arranged to face each other in parallel, and a connecting wall portion 63 that connects the two side wall portions 61 and 62 to each other.

[0044] Further, the piston 60 has a shape having a major axis A and a minor axis B that fit the inner periphery of the wall portion 21 of the cylinder 20. Specifically, as shown in FIG. 6, both side surfaces in the direction of the major axis A of each side wall portion 61, 62 constituting the piston 60 are parallel to each other, and both side surfaces in the direction of the minor axis B are arc-shaped so as to fit the inner peripheral shape of the wall portion 21 of the cylinder 20. Further, the outer periphery of the connecting wall portion 63 has a similar shape that is smaller than the outer peripheries of the two side wall portions 61 and 62.

[0045] Further, the other end portion 42 in the axial direction of the rod 40 is connected to the connecting surface 61a (outer surface) of the first side wall portion 61, so that the piston 60 and the rod 40 are integrated. Note that the axis C2 of the piston 60 is made to coincide with the axis C1 of the rod 40. Further, the space surrounded by the pair of side wall portions 61, 62 and the connecting wall portion 63 forms the annular groove 64. Further, the outer peripheral surface of the connecting wall portion 63 forms the bottom surface 64a of the annular groove 64.

[0046] Further, as shown in FIG. 5, on one side (one side) of the portion of the first side wall portion 61 extending along the major axis A, a notch portion 65 notched with a predetermined width is provided. When the piston 60 moves in the damper return direction F2, a part of the seal ring 69 enters the notch portion 65 (this will be described later).

[0047] Furthermore, as shown in FIG. 5, a concave groove 66 forming a concave groove is formed on the bottom surface 64a of the annular groove 64 and the bottom surface of the notch portion 65. One end opening 66a of the concave groove 66 extends to the connection surface 61a of the first side wall portion 61 of the piston 60 with the rod 40 and communicates with the through hole 44. Also, an opening 66b (upper opening) located on the piston outer peripheral side of the portion of the concave groove 66 located in the annular groove 64 is closed by the seal ring 69 (closed except when a part of the seal ring 69 is deformed as described below). When the piston 60 moves in the damper return direction F2 and a part of the seal ring 69 is deformed so as to enter the notch portion 65, the opening 66b of the concave groove 66 opens. Note that this concave groove 66 forms an exhaust passage for exhausting the air in the first air chamber V1 to the second air chamber V2 side when the piston 60 moves in the damper return direction F2 (this will be described later).

[0048] Also, as shown in FIG. 3, inside the both side wall portions 61, 62 and the connecting wall portion 63, a plurality of spaces K defined by the partition wall 67 are provided, and each space K has an opening on the second side wall portion 62 side. Further, an orifice 68 communicating with the through hole 44 is formed in the piston 60. The other end of the orifice 68 communicates with the first air chamber V1 through the space K, and one end communicates with the through hole 44 (see FIG. 3). That is, the orifice 68 communicates the first air chamber V1 and the second air chamber V2 in the cylinder 20 with each other through the space K. Note that the damper braking force is adjusted by the flow resistance of the air flowing through the orifice 68.

[0049] Next, with reference to FIGS. 7 to 13 and the like, the guide cap 70 will be described.

[0050] Furthermore, this guide cap 70 has an insertion wall portion 71 inserted inside the opening 23 of the cylinder 20, an insertion hole 73 into which the rod 40 is inserted, and an elastically deformable (flexibly deformable) elastic piece portion 77 provided at a portion of the insertion wall portion 71 facing the rod 40.

[0051] The insertion wall portion 71 has a shape having a major axis A and a minor axis B so as to conform to the wall portion 21 of the cylinder 20. Specifically, this insertion wall portion 71 linearly extends in the direction along the major axis A, and a pair of major axis wall portions 74, 74 arranged to be parallel to each other and facing each other, and a pair of minor axis wall portions 75, 75 arranged on the minor axis B side, having an arcuate bent shape and connecting both ends of the major axis wall portions 74, 74. As shown in FIG. 11, the pair of major axis wall portions 74, 74 are arranged inside the pair of major axis wall portions 21a, 21a of the cylinder 20 and outside the surface (the surface along the width direction) of the rod 40 along the major axis A. On the other hand, the pair of minor axis wall portions 75, 75 are arranged inside the pair of minor axis wall portions 21b, 21b of the cylinder 20 and outside the surface (the surface along the thickness direction) of the rod 40 along the minor axis B.

[0052] Also, at one axial end of the insertion wall portion 71, a cover wall portion 72 forming the insertion hole 73 is continuously provided. This cover wall portion 72 has a substantially oval shape provided with arcuate surfaces on both side portions in the width direction so as to conform to the opening 23 of the cylinder 20, and its outer peripheral edge portion 72a protrudes from the outer peripheral edge portion of the insertion wall portion 71 by a predetermined length (protrudes like a flange). And when the guide cap 70 is attached to the opening 23 of the cylinder 20, the outer peripheral edge portion 72a of the cover wall portion 72 comes into contact with one end surface of the wall portion 21 of the cylinder 20 (see FIG. 13).

[0053] Further, the intermediate portions 74a, 74a in the width direction of the pair of long-axis wall portions 74, 74 that constitute the insertion wall portion 71 are recessed so as to be close to each other. Note that the inner surfaces of the intermediate portions 74a, 74a (the surfaces facing the radially inner side of the guide cap 70, which can also be referred to as opposing surfaces) are parallel to each other.

[0054] Furthermore, the guide cap 70 is formed with engaging claws 76 that engage from the inner circumference with an engaging hole 23a provided in the opening 23 of the cylinder 20, and the engaging claws 76 are arranged at positions corresponding to the outside of the standing portion 45a of a rib 45 provided on the rod 40.

[0055] Here, engaging claws 76 project from both side portions 74b, 74b in the width direction of each long-axis wall portion 74, from the outer surface (the surface facing the radially outer side of the guide cap 70). A total of four engaging claws 76 are provided here. Each engaging claw 76 is arranged at a position corresponding to the outside of the standing portion 45a of each rib 45 provided on the rod 40 (see FIGS. 1 and 13). Also, when passing through the opening 23 of the cylinder 20, the top of each engaging claw 76 is pressed against the wall portion 21 of the cylinder 20, so that the engaging claw 76 is bent and deformed inward of the guide cap 70 (the engaging claws 76 are bent and deformed for both side portions 74b of the long-axis wall portion 74). Then, the insertion wall portion 71 of the guide cap 70 is inserted inside the opening 23 of the cylinder 20, and while bending the engaging claws 76, it is pushed in, and by engaging the corresponding engaging claws 76 of the guide cap 70 with the respective engaging holes 23a of the opening 23 from the inner circumference, as shown in FIG. 2, the guide cap 70 is attached to the opening 23 of the cylinder 20.

[0056] Also, a pair of slits 77a, 77a that extend along the axial direction and are arranged parallel to each other are formed in the intermediate portion 74a of each long-axis wall portion 74 of the insertion wall portion 71, and elastic piece portions 77 are respectively formed so as to be bendably deformed through these pair of slits 77a, 77a. This elastic piece portion 77 is provided at a position corresponding to the rod-side concave groove 49 of the rod 40 (see FIG. 12).

[0057] Furthermore, on both sides of the elastic piece portion 77, a pair of cap-side guide portions 78, 78 are provided so as to project so as to face the surface of the rod 40 in the direction along the major axis A.

[0058] Specifically, as shown in FIGS. 8 to 10, on both sides in the width direction of the intermediate portion 74a of each major axis wall portion 74 of the insertion wall portion 71, from the inner surface thereof (the surface facing the surface of the rod 40 along the major axis A), a pair of cap-side guide portions 78, 78 extend along the axial direction of the guide cap 70, respectively. Here, a total of four cap-side guide portions 78 are provided. Further, each cap-side guide portion 78 has a flat surface as its protruding surface (the tip surface in the protruding direction), and is provided over the entire length of the cap from one end in the axial direction of the guide cap 70 to the other end (across the cover wall portion 72 and the insertion wall portion 71), and is arranged to face the rod-side guide portion 47 provided on the rod 40 with a predetermined gap therebetween (see FIG. 11). By these cap-side guide portions 78 and rod-side guide portions 47, the piston rod 30 is guided when it moves in the axial direction.

[0059] And, from the inner surface of each elastic piece portion 77 (the surface facing the surface of the rod 40 along the major axis A), convex portions 79 project respectively, and convex curved surfaces 80 are provided at the tops of the convex portions 79, respectively.

[0060] More specifically, as shown in FIGS. 8 and 9, the convex portion 79 is arranged at the center in the width direction (the direction along the major axis A) and at the center in the axial direction on the inner surface of the elastic piece portion 77. Further, as shown in FIG. 12, the convex portion 79 protrudes in a spherical shape so as to be convex toward the axis C3 of the guide cap 70 while drawing an R-shaped curved surface from the inner surface of the elastic piece portion 77 (so as to be convex toward the surface of the rod 40 along the major axis A), and the top thereof is also a convex R-shaped curved surface that draws an R-shaped curved surface, and the top forms the convex curved surface 80. Further, the pair of convex portions 79, 79 are arranged such that the convex curved surfaces 80, 80 face each other (see FIGS. 10 and 11).

[0061] Then, the convex surface 80 enters the concave surface 50 on the rod 40 side and comes into contact with and slides on the concave surface 50, thereby guiding the axial movement of the piston rod 30.

[0062] Also, in this damper device 10, with the piston rod 30 inserted into the cylinder 20 and a guide cap attached to the opening 23 of the cylinder 20, as shown in FIGS. 11 and 12, the non-elastic-deforming concave surface 50 on the rod 40 side presses the convex surface 80 on the elastic piece portion 77 side of the guide cap 70, causing the elastic piece portion 77 to elastically deform (although not shown, the elastic piece portion 77 deforms slightly elastically), and due to the elastic restoring force, the convex surface 80 on the elastic piece portion 77 side presses against the concave surface 50 on the rod 40 side. As a result, the convex surface 80 and the concave surface 50 are in contact with each other in a state where they are, so to speak, engaged with each other in a concave-convex manner. Here, with the bottom 50a of the concave surface 50 as the center, the apex 80a of the convex surface 80 and its peripheral portion are in contact (surface contact) within a predetermined range (see FIG. 12). Thereby, when the piston rod 30 moves in the damper braking direction F1 or the damper return direction F2 with respect to the cylinder 20, the convex surface 80 contacts the concave surface 50 while the piston rod 30 moves, that is, the concave surface 50 slides (moves while slidingly contacting) on the convex surface 80 (the concave surface 50 on the piston rod 30 side that moves axially with respect to the cylinder 20 slides on the convex surface 80 on the guide cap 70 side attached to and fixed to the opening 23 of the cylinder 20), and thereby the axial movement of the piston rod 30 is configured to be guided.

[0063] Furthermore, as shown in FIG. 11, in this embodiment, when the distance between the bottoms 50a, 50a of the pair of concave curved surfaces 50, 50 provided on both surfaces 43a, 43b in the thickness direction of the rod 40 is "H1", and the distance between the vertices 80a, 80a of the pair of convex curved surfaces 80, 80 arranged opposite to each other on the insertion wall portion 71 of the guide cap 70 is "H2", it is set such that H1 > H2. Thereby, when the piston rod 30 is inserted into the cylinder 20 and the guide cap is attached to the opening 23 of the cylinder 20, the pair of concave curved surfaces 50, 50 press the pair of convex curved surfaces 80, 80, elastically deforming the pair of elastic piece portions 77, 77, so that the convex curved surface 80 and the concave curved surface 50 are always in contact with each other.

[0064] Also, as shown in FIG. 12, when the radius of curvature of the convex curved surface 80 with respect to the axis C3 of the guide cap 70 is "R2", the radius of curvature R2 of the convex curved surface 80 is formed to be smaller than the radius of curvature R1 of the concave curved surface 50 (R1 > R2). That is, the convex curved surface 80 is a surface that draws a sharper curve than the concave curved surface 50. As a result, as shown in FIG. 12, with a predetermined clearance generated between the concave curved surface 50 and the convex curved surface 80 (clearance is generated between the concave curved surface 50 and the circumferential both-side portions of the vertex 80a of the convex curved surface 80), the convex curved surface 80 and the concave curved surface 50 are in contact with each other.

[0065] Furthermore, the elastic piece portion 77 is disposed at a position separated from the rod 40 more than the protruding surfaces of the pair of cap-side guide portions 78, 78, and one of the convex curved surface or the concave curved surface is provided on the elastic piece portion 77.

[0066] Specifically explaining this, in the case of this embodiment, the elastic piece portion 77 is disposed at a position lower than the protruding surfaces of the pair of cap-side guide portions 78, 78 (a position separated from the rod 40). That is, as shown in FIGS. 11 and 12, the elastic piece portion 77 is disposed such that its inner surface is at a position lower (a retracted position) than the flat protruding surface of the cap-side guide portion 78. And, as shown in FIG. 12, the apex 80a of the convex curved surface 80 provided on the elastic piece portion 77 is disposed at a position separated from the rod 40 (which can also be said to be a lower position or a retracted position) than the flat protruding surfaces of the pair of cap-side guide portions 78, 78. Note that the elastic piece portion 77 is provided with a convex portion 79 and a convex curved surface 80, and the entirety including these convex portion 79 and convex curved surface 80 is disposed at a position separated from the rod 40 than the protruding surface of the cap-side guide portion 78.

[0067] Further, in the guide cap 70, insertion grooves 73a into which the ribs 45 of the rod 40 are inserted are formed at both ends of the insertion hole 73.

[0068] Specifically, as shown in FIGS. 8 to 10, from both side portions in the width direction (the direction along the long axis A) of the insertion hole 73 formed in the cover wall portion 72, a pair of insertion grooves 73a, 73a are notch-formed toward one end in the thickness direction (the direction along the short axis B), and also a pair of insertion grooves 73a, 73a are notch-formed toward the other end in the thickness direction. That is, a total of four insertion grooves 73a are formed, and as a result, when the guide cap 70 is viewed from the axial direction, the insertion hole 73 has a substantially H shape (see FIG. 10). Also, as shown in FIG. 11, the corresponding ribs 45 of the rod 40 are inserted into the respective insertion grooves 73a, and the rod 40 is guided when the piston rod 30 moves in the axial direction. Further, as shown in FIG. 8, on the outer surface side of the cover wall portion 72, rod pressing protrusions 81 project from the outer edge portions of the respective insertion grooves 73a. When the rod 40 tilts, the rod pressing protrusion 81 abuts against the rib 45 of the rod 40 to restrict the tilt of the rod 40.

[0069] (Modification example) The shapes and structures of the cylinder, piston rod, the rod and piston constituting the piston rod, seal ring, orifice, etc. that make up the damper device in the present invention are not limited to the above aspects.

[0070] The wall portion 21 of the cylinder 20 in this embodiment has a thin cylindrical shape, but the wall portion of the cylinder may be, for example, a substantially elliptical cylindrical shape or the like, as long as it has a shape with a major axis and a minor axis. Also, the rod, piston, guide cap, etc. are preferably shaped to correspond to the wall portion of the cylinder. Note that the rod does not necessarily have to be plate-shaped.

[0071] Also, in this embodiment, the end wall 25 is disposed and closed on the other end side in the axial direction of the cylinder 20, but for example, a through-hole may be formed in the end wall disposed at the other end of the cylinder, and this through-hole may be opened and closed with a seal cap.

[0072] Furthermore, in this embodiment, the concave curved surface 50 is provided on the rod 40 side, and the convex curved surface 80 is provided on the elastic piece portion 77 side of the guide cap 70, but a convex curved surface may be provided on the rod side and a concave curved surface may be provided on the elastic piece portion side of the guide cap (this will be described in other embodiments).

[0073] Also, the concave curved surface 50 in this embodiment forms a concave R curved surface, and the convex curved surface 80 forms a convex R curved surface, but the concave and convex curved surfaces are not limited to R-shaped curved surfaces, as long as they are surfaces that can contact each other.

[0074] Furthermore, in this embodiment, the entire inner surface of the concave groove 49 on the rod side forms the concave curved surface 50, but for example, the concave groove on the rod side may be a square frame-shaped concave groove with an upper opening, or a concave groove with tapered surfaces on both side surfaces that expand upward, and a concave curved surface may be formed on their inner surfaces (for example, the bottom surface).

[0075] Also, in this embodiment, the entire convex portion 79 is a spherical convex portion, and a convex curved surface 80 is provided at its top. However, for example, the convex portion may be cylindrical, frustum of a cone (a frustum with a circular base), frustum of a pyramid, etc., and a convex curved surface may be provided at their tops.

[0076] Furthermore, in this embodiment, the convex curved surface 80 is a surface that draws a curve sharper than the concave curved surface 50. With the bottom 50a of the concave curved surface 50 as the center, the apex 80a of the convex curved surface 80 and its peripheral portion are in contact (surface contact) within a predetermined range and are engaged in a concave-convex manner. However, for example, the radius of curvature of the concave curved surface may be made even larger than the radius of curvature of the convex curved surface, so that the apex or the peripheral portion of the convex curved surface contacts the bottom of the concave curved surface in a state close to point contact, or the radius of curvature of the concave curved surface and the convex curved surface may be made closer to bring them into contact in a state close to concave-convex fitting.

[0077] Also, in this embodiment, the elastic piece portion 77 is disposed at a position separated from the rod 40 more than the protruding surfaces of the pair of cap-side guide portions 78, 78, and the convex curved surface 80 is also disposed at a position separated from the rod 40 more than the protruding surfaces of the pair of cap-side guide portions 78, 78. However, for example, while maintaining the state where the elastic piece portion is disposed at a position separated from the rod more than the protruding surfaces of the pair of cap-side guide portions, the convex curved surface or the concave curved surface may be set at the same height as the protruding surface of the cap-side guide portion, or the convex curved surface or the concave curved surface may protrude higher than the protruding surface of the cap-side guide portion (protrude in a direction closer to the rod than the protruding surface of the cap-side guide portion).

[0078] Furthermore, in this embodiment, when the piston 60 moves in a direction away from the end wall 25 of the cylinder 20 (when the piston 60 moves in the damper braking direction F1), a braking force due to the decompression of the first air chamber V1 acts, and when the piston 60 moves in a direction approaching the end wall 25 of the cylinder 20 (when the piston 60 moves in the damper return direction F2), the braking force is configured to be released. However, conversely, it may be configured such that when the piston 60 moves in a direction approaching the end wall 25 of the cylinder 20, a damper braking force acts, and when the piston 60 moves in a direction away from the end wall 25 of the cylinder 20, the damper braking force is released.

[0079] Also, in this embodiment, one member is a fixed body such as a housing part of an instrument panel, and the other member is an opening / closing body such as a glove box or a lid. However, the pair of members is not particularly limited as long as they can approach and separate from each other.

[0080] Furthermore, in this embodiment, an air chamber (first air chamber V1) is formed in the cylinder 20 on the insertion direction side of the piston rod 30 with respect to the seal ring 69. However, an air chamber may be provided on the side opposite to the piston rod insertion direction in the cylinder. For example, an exhaust hole is formed in the end wall of the cylinder, and a seal cap that can open and close the exhaust hole is attached to the periphery of the exhaust hole. Further, a guide cap attached to the opening at one end of the cylinder has a structure capable of sealing the periphery of the opening and a structure capable of sealing the gap between the insertion hole and the rod inserted through the insertion hole, so as to provide a sealed air chamber on the side opposite to the piston rod insertion direction in the cylinder. Then, when the piston moves in a direction away from the end wall of the cylinder (when it moves in the direction opposite to the piston rod insertion direction), the air chamber is pressurized, and a damper braking force is exerted. When the piston moves close to the end wall of the cylinder (when it moves in the piston rod insertion direction side), the seal cap opens the exhaust hole, and the air in the air chamber is exhausted, and the damper braking force is released.

[0081] (Function and Effect) Next, the function and effect of the damper device 10 having the above configuration will be described.

[0082] In this damper device 10, when one member (such as a fixed body) and the other member (such as an opening / closing body) are in a state of being close to each other, the piston 60 is stationary within the cylinder 20.

[0083] When the other member moves in a direction away from one member from the above state (when the opening / closing body opens from the fixed body), the piston 60 moves within the cylinder 20 in the damper braking direction F1, and the rod 40 is pulled out from the opening 23 side of the cylinder 20. Then, since the first air chamber V1 within the cylinder 20 is depressurized, a damper braking force is applied to the piston 60. As a result, the other member can be slowly moved with respect to one member (the opening / closing body can be slowly opened from the fixed body).

[0084] Also, when the other member is moved in a direction approaching one member (when the opening / closing body is closed with respect to the fixed body), the piston 60 moves within the cylinder 20 in the damper return direction F2, and the rod 40 is pushed into the cylinder 20.

[0085] Then, a predetermined circumferential portion of the seal ring 69 deforms so as to enter the notch 65 formed in the piston 60. Thereby, the opening 66b of the concave groove 66 opens, and the air in the first air chamber V1 within the cylinder 20 passes through the annular groove 64 and the concave groove 66, flows out from the opening 66a of the concave groove 66 to the through hole 44, and is disposed in the second air chamber V2. As a result, the damper braking force acting on the piston 60 is released, and the piston 60 can be returned to the initial position.

[0086] And in this damper device 10, between the rod 40 and the elastic piece portion 77, a convex portion 79 formed on the elastic piece portion 77 enters and abuts against a concave portion formed on the rod 40. More specifically, between the rod 40 and the elastic piece portion 77 provided on the guide cap 70, the axial movement of the piston rod 30 is guided by a convex curved surface 80 and a concave curved surface 50 into which the convex curved surface 80 enters and abuts.

[0087] As a result, when the piston rod 30 moves within the cylinder 20, the play in the thickness direction (the direction along the major axis A) and the width direction (the direction along the minor axis B) of the rod 40 can be restricted. That is, as shown in FIGS. 11 and 12, while the convex curved surface 80 and the concave curved surface 50 are in contact with each other in a state of being engaged with each other like uneven surfaces, when the piston rod 30 moves, the concave curved surface 50 slides on the convex curved surface 80, and the axial movement of the piston rod 30 is guided. Therefore, even if an external force acts on the rod 40, the rod 40 is restricted from moving in the thickness direction and the width direction, and the axial movement of the piston rod 30 is made smooth.

[0088] In this way, in this damper device 10, the restriction of the play in the thickness direction and the width direction of the rod 40 when the piston rod 30 moves within the cylinder 20 can be realized by a simple structure with the convex curved surface 80 and the concave curved surface 50 without providing a plurality of elastic tongue pieces like the air damper in Patent Document 1.

[0089] Further, when assembling the damper device 10 or when the piston rod 30 moves axially, the rod 40 can be centered with respect to the guide cap 70 such that the apex 80a of the convex surface 80 is positioned at the bottom 50a of the concave surface 50. That is, when the convex surface 80 abuts against a location on the inner peripheral surface of the concave surface 50 other than the bottom 50a, the concave surface 50 slides on the convex surface 80 so that the apex 80a of the convex surface 80 is positioned at the bottom 50a of the concave surface 50, and the rod 40 can be centered with respect to the guide cap 70. As a result, the assembly operation of the piston rod 30 and the guide cap 70 can be improved, and during the axial movement of the piston rod 30, it becomes easier to restrict the displacement of the rod 40 in the thickness direction and the width direction.

[0090] In the case of this embodiment, as shown in FIG. 12, since the radius of curvature R2 of the convex surface 80 is formed to be smaller than the radius of curvature R1 of the concave surface 50, the centering operation of the rod 40 with respect to the guide cap 70, which positions the apex 80a of the convex surface 80 at the bottom 50a of the concave surface 50, is more easily performed.

[0091] Furthermore, since the above-described guide structure is provided in the portion of the guide cap 70 inserted into the cylinder 20 (here, the convex surface 80 that forms part of the guide structure is provided on the elastic piece portion 77 provided on the insertion wall portion 71), an increase in the size of the guide cap 70 can be suppressed.

[0092] Also, in this embodiment, a convex portion 79 protrudes from the elastic piece portion 77, and a convex surface 80 is provided at the top thereof. In the rod 40, a rod-side concave groove 49 that forms a concave portion along its axial direction extends, and a concave surface 50 is provided on the inner surface of the rod-side concave groove 49. As shown in FIG. 12, when the radius of curvature of the concave surface 50 with respect to the axis C1 of the rod 40 is R1 and the radius of curvature of the convex surface 80 with respect to the axis C3 of the guide cap 70 is R2, R1 > R2.

[0093] According to the above aspect, a convex portion 79 protrudes from the elastically deformable elastic piece portion 77, and a convex curved surface 80 is provided at the top thereof. The convex curved surface 80 enters and abuts against the concave curved surface 50 on the inner surface of the rod-side concave groove 49. Since the radii of curvature R1 and R2 of the concave curved surface 50 and the convex curved surface 80 are set as described above, it is possible to easily center the rod 40 with respect to the guide cap 70, and it becomes easier to hold the piston rod 30 in a stable posture. Further, when the piston rod 30 moves in the axial direction, even if the piston rod 30 tilts, it is possible to hardly cause an increase in sliding resistance and to prevent the piston rod 30 from rattling.

[0094] Furthermore, as shown in FIGS. 11 and 12, in this embodiment, a pair of cap-side guide portions 78, 78 that protrude so as to face the surface of the rod 40 in the direction along the major axis A are provided on both sides of the elastic piece portion 77. The elastic piece portion 77 is disposed at a position spaced apart from the rod 40 relative to the protruding surfaces of the pair of cap-side guide portions 78, 78. One of a convex curved surface or a concave curved surface is provided on the elastic piece portion 77 (here, the convex curved surface 80 is provided). The rod 40 is disposed to face the pair of cap-side guide portions 78, 78 provided on the guide cap 70, and has a pair of rod-side guide portions 47, 47 that extend in the axial direction and a protrusion that protrudes toward the guide cap 70 side relative to the protruding surfaces of the pair of rod-side guide portions 47, 47 and enters between the pair of cap-side guide portions 78, 78 and extends in the axial direction. The other of a convex curved surface or a concave curved surface is provided on the ridge portion 48 (here, the concave curved surface 50 is provided).

[0095] With the above-described configuration, when the rod 40 is inserted into and assembled with the insertion hole 73 of the guide cap 70, it is possible to prevent the rod 40 from being caught by the convex curved surface 80 provided on the elastic piece portion 77 of the guide cap 70, and the assembling workability of the damper device 10 can be further improved. Further, as in the second embodiment shown in FIGS. 14 to 16 described later, when the concave curved surface 83 is provided on the elastic piece portion 77, it is possible to prevent the rod 40 from being caught by the side edge portion, corner portion, etc. of the convex base portion 82 provided with the concave curved surface 83. Also in this case, the assembling workability of the damper device 10 can be further improved. In the case of this embodiment, since the outer surface of one end portion 41 of the rod 40 and the outer surfaces of the respective rod-side guide portions 47, 47 are at the same height (on the same plane), if the elastic piece portion 77 and the respective cap-side guide portions 78 are at the same height (on the same plane) and the convex curved surface 80 protrudes more than the protruding surface of the respective cap-side guide portions 78 (when close to the rod 40), the one end portion 41 of the rod 40 is likely to be caught by the convex curved surface 80, and the assembling workability of the damper device 10 deteriorates.

[0096] Also, in this embodiment, ribs 45 are provided on both sides of the surfaces 43a, 43a of the rod 40 along the major axis A, standing upright in a direction perpendicular to the surfaces 43a along the major axis A and extending in the axial direction. A standing portion 45a, which stands higher than the other portions, is provided at the portion of the rib 45 located on the piston 60 side (see FIG. 5). The standing portion 45a is capable of abutting against the inner peripheral surfaces of both end portions of the insertion hole 73 of the guide cap 70 (see FIG. 13). The guide cap 70 is formed with insertion grooves 73a into which the ribs 45 of the rod 40 are inserted at both end portions of the insertion hole 73. An engaging claw 76 that engages from the inner periphery is formed in a deflectable manner in an engaging hole 23a provided in the opening 23 of the cylinder 20, and the engaging claw 76 is disposed at a position corresponding to the outside of the standing portion 45a of the rib 45.

[0097] With the above configuration, when the piston rod 30 is pulled to the maximum from the cylinder 20, as shown in Fig. 13, the standing portion 45a of the rib 45 of the rod 40 is located inside the engaging claw 76 of the guide cap 70. Therefore, the deflection of the engaging claw 76 inward of the cylinder can be restricted, and the guide cap 70 can be prevented from coming off from the opening 23 of the cylinder 20. Further, since the rib 45 of the rod 40 is inserted into the insertion groove 73a of the guide cap 70, the inclination of the piston rod 30 can be suppressed.

[0098] Furthermore, in this embodiment, a groove 51 extending along the axial direction is formed between the rib 45 and the rod-side guide portion 47 on the surface of the rod 40 along the long axis A (see Fig. 11).

[0099] Since the groove 51 as described above is formed, even if the piston rod 30 is inclined and abuts against the inner circumference of the insertion wall portion 71 of the guide cap 70, the contact area can be reduced by the groove 51. Therefore, an increase in sliding resistance when the piston rod 30 is inclined can be suppressed.

[0100] (Second Embodiment of the Damper Device) Figs. 14 to 16 show a second embodiment of the damper device according to the present invention. Note that the same reference numerals are given to substantially the same parts as those in the above embodiment, and the description thereof is omitted.

[0101] In the damper device of this embodiment, a convex portion and a convex curved surface 53 are formed on the rod 40A side, and a concave portion and a concave curved surface 83 are formed on the guide cap 70A side. Further, on the rod 40A, a rod-side ridge 52 forming the "convex portion" in the present invention extends along its axial direction, and a convex curved surface 53 is provided at the top of the rod-side ridge 52. A convex-shaped base 82 projects from the elastic piece portion 77 of the guide cap 70A, and a concave curved surface 83 is provided at the top thereof.

[0102] More specifically, as shown in FIG. 14, a rod-side protrusion 52 forming a protrusion extends along the axial direction of the rod 40A from the outer surface of the protrusion 48 provided on the rod 40A (the surface facing the inner peripheral surface of the cylinder 20). A convex surface 53 forming a convex R surface is provided at the top of the rod-side protrusion 52 forming a convex portion, and this convex surface 53 extends along the axial direction of the rod 40A.

[0103] On the other hand, as shown in FIG. 15, a convex base 82 having a substantially frustum-shaped pyramid is provided so as to protrude from the inner surface of each elastic piece portion 77 of the guide cap 70A, with the bottom having a substantially rectangular shape and gradually protruding higher toward the opposing elastic piece portion 77. A concave surface 83 forming a concave R surface is provided at the top of this convex base 82.

[0104] Further, as shown in FIG. 16, when the radius of curvature of the convex surface 53 with respect to the axis C1 of the rod 40A is R3 and the radius of curvature of the concave surface 83 with respect to the axis C3 of the guide cap 70A is R4, R3 < R4.

[0105] And, as shown in FIG. 16, the convex surface 53 on the rod 40A side fits into and abuts against the concave surface 83 on the guide cap 70A side.

[0106] In this embodiment, since the axial length of the convex base 82 provided on the elastic piece portion 77 of the guide cap 70A can be made shorter than the rod-side protrusion 52 provided on the rod 40A, even if the piston rod 30 tilts during the axial movement of the piston rod 30, it is possible to make it difficult to cause an increase in sliding resistance and to make the piston rod 30 less likely to rattle. Further, since the radii of curvature R3 and R4 of the convex surface 53 and the concave surface 83 are set as described above, it becomes easier to center the rod 40A with respect to the guide cap 70A and to keep the piston rod 30 in a stable posture.

[0107] (Third Embodiment of the Damper Device) Figures 17 to 19 show a third embodiment of the damper device according to the present invention. In addition, the same reference numerals are given to substantially the same parts as those in the above embodiment, and the description thereof is omitted.

[0108] In the damper device of this embodiment, a concave portion 55 is formed in the rod 40B, and a convex portion 79 is formed in the guide cap 70B.

[0109] Further, inclined surfaces 56, 56 that extend from the opening 57 side of the concave portion 55 toward the bottom portion 58 side are provided on the inner surfaces on both sides of the concave portion 55. The inclined surfaces 56, 56 in this embodiment are shaped to become narrower from the opening 57 side of the concave portion 55 toward the bottom portion 58 side. And the convex portion 79 is in contact with the inclined surfaces 56, 56 of the concave portion 55 at two locations, and among the contact portions between the convex portion 79 and the inclined surfaces 56, 56 of the concave portion 55, the side of the convex portion 79 is a convex curved surface forming a curved surface.

[0110] More specifically, the concave portion 55 in this embodiment is formed at a predetermined depth from the maximum protruding portion of the protruding strip portion 48 protruding from the shaft portion 43 of the rod 40B (the portion most separated from the surface 43a in the thickness direction of the shaft portion 43), and extends in the axial direction of the rod 40B.

[0111] Note that both sides of the concave portion 55 mean both sides along the width direction of the rod 40B (both sides in the direction along the long axis A of the rod 40B) (the same meaning also applies in the fourth embodiment shown in FIGS. 20 and 21).

[0112] Then, inclined surfaces 56, 56 having a tapered surface shape that gradually becomes narrower are provided on the inner surfaces on both sides of the concave portion 55, from the opening 57 side of the concave portion 55 (the opening portion facing the bottom portion 58. Here, it is the opening portion located on the maximum protruding surface of the protruding strip portion 48) toward the bottom portion 58 side of the concave portion 55 (the side opposite to the opening 57 and inward in the thickness direction of the shaft portion 43 of the rod 40B), and the pair of inclined surfaces 56, 56 are the narrowest at the bottom portion 58 (see FIG. 17).

[0113] On the one hand, as shown in Fig. 18, the convex portion 79 has the same shape and structure as in the first embodiment, and has a convex surface 80 forming a curved surface.

[0114] And, as shown in Fig. 19, the convex surface 80 of the convex portion 79 that has entered the concave portion 55 is configured to abut against the pair of inclined surfaces 56, 56 of the concave portion 55, respectively (a structure in which the convex surface and the tapered surface abut at two locations).

[0115] In this embodiment, as described above, since the convex surface 80 of the convex portion 79 abuts against the inclined surfaces 56, 56 of the concave portion 55 at two locations, it is possible to more appropriately regulate the play in the thickness direction and width direction of the rod 40B when the piston rod 30 moves within the cylinder 20.

[0116] Note that the inclined surfaces 56, 56 in this embodiment form a tapered surface shape over the entire range from the opening 57 to the bottom 58 of the concave portion 55, but a tapered surface may be provided only in a predetermined range within the range from the opening to the bottom of the concave portion, as long as the convex portion can abut at two locations.

[0117] Also, the inclined surface 56 in this embodiment forms a tapered surface shape, so to speak, a linear shape. However, the "inclined surface" in the present invention may be a shape that gradually narrows while drawing a curved surface shape such as a convex curved surface or a concave curved surface from the opening side to the bottom of the concave portion (this will be described in the fourth and sixth embodiments below). That is, the "inclined surface" of the present invention includes a curved surface.

[0118] (Fourth Embodiment of the Damper Device) Figs. 20 and 21 show a fourth embodiment of the damper device according to the present invention. Note that the same reference numerals are given to substantially the same parts as in the above embodiments, and the description thereof is omitted.

[0119] The damper device of this embodiment basically has the same shape as that of the third embodiment shown in FIGS. 17 to 19, but the shape of the concave portion 55 is different. Further, a concave portion 55 is formed in the rod 40C, and a convex portion 79 is formed in the guide cap 70B.

[0120] And in this embodiment, inclined surfaces 56c, 56c are provided on the inner surfaces on both sides of the concave portion 55, and the pair of inclined surfaces 56c, 56c are the narrowest at the bottom 58 of the concave portion 55. Further, convex curved surfaces 56d, 56d that are convex toward the guide cap 70B side with a gentle R shape are provided in the vicinity of the opening 57 of the inclined surfaces 56c, 56c.

[0121] In the case of this embodiment, as shown in FIG. 21, the convex curved surface 80 of the convex portion 79 that has entered the concave portion 55 contacts the convex curved surfaces 56d, 56d having an R shape on the inner surfaces on both sides of the concave portion 55, respectively (a structure in which the convex curved surfaces contact at two locations). And since the convex curved surface 80 of the convex portion 79 contacts the convex curved surfaces 56d, 56d of the inclined surfaces 56c, 56c of the concave portion 55 at two locations, the same operational effects as those of the third embodiment can be obtained.

[0122] (Fifth Embodiment of the Damper Device) FIGS. 22 to 24 show a fifth embodiment of the damper device according to the present invention. Note that the same reference numerals are given to substantially the same parts as those in the above embodiment, and the description thereof is omitted.

[0123] In the damper device of this embodiment, a convex portion 46 is formed in the rod 40D, and a concave portion 85 is formed in the guide cap 70D.

[0124] Further, inclined surfaces 87, 87 that become narrower from the opening 57 side to the bottom 89 side of the concave portion 85 are provided on the inner surfaces on both sides of the concave portion 85, and the convex portion 46 contacts the inclined surfaces 87, 87 of the concave portion 85 at two locations. A convex curved surface 53 having a curved surface is provided on the convex portion 46 side among the contact portions between the convex portion 46 and the inclined surfaces 87, 87 of the concave portion 85.

[0125] As shown in FIG. 23, in the case of this embodiment, a pair of convex bases 86, 86 project from the inner surface of the elastic piece portion 77 of the guide cap 70D, and between these pair of convex bases 86, 86, a concave portion 85 is formed at a predetermined depth from the maximum protruding portion of the convex base 86 (the portion most separated from the inner surface of the elastic piece portion 77).

[0126] More specifically, on both inner surfaces (both opposing surfaces of the pair of convex bases 86, 86) of the concave portion 85, which are the side of the opening 88 of the concave portion 85 (the opening portion facing the bottom 89 and located on the maximum protruding surface of the convex base 86), inclined surfaces 87, 87 having a tapered surface shape that gradually narrows toward the bottom 89 of the concave portion 85 (the side opposite to the opening 88 and at the same height as the inner surface of the elastic piece portion 77) are provided, and the pair of inclined surfaces 87, 87 are the narrowest at the bottom 89 of the concave portion 85.

[0127] Also, on the outer peripheral surface of a predetermined convex base 86 from the inclined surface 87 provided on the opposing surface with the other convex base 86 toward the surface (base end surface) opposite to the opposing surface, an inclined surface 87 is also formed.

[0128] Note that both sides of the concave portion 85 mean both sides along the width direction of the guide cap 70D (the same meaning also in the sixth embodiment shown in FIGS. 25 to 27).

[0129] On the other hand, as shown in FIG. 22, the convex portion 46, similar to the second embodiment, projects from the outer surface of the protruding strip portion 48, forms a protruding strip extending along the axial direction of the rod 40D, and has a convex curved surface 53.

[0130] And as shown in FIG. 24, the convex curved surface 53 of the convex portion 46 that has entered the concave portion 85 comes into contact with the pair of inclined surfaces 87, 87 of the concave portion 85 respectively (a structure where the convex curved surface and the tapered surface come into contact at two locations). That is, since the convex curved surface 53 of the convex portion 46 comes into contact with the inclined surfaces 87, 87 of the concave portion 85 at two locations, the same operational effects as in the third and fourth embodiments can be obtained.

[0131] (Sixth Embodiment of the Damper Device) Figures 25 to 27 show a sixth embodiment of the damper device according to the present invention. In addition, the same reference numerals are given to substantially the same parts as those in the above embodiment, and the description thereof is omitted.

[0132] The damper device of this embodiment basically has the same shape as that of the fifth embodiment shown in FIGS. 22 to 24, but the shape of the concave portion 85 is different. Further, a convex portion 46 having a convex curved surface 53 is formed on the rod 40E, and a concave portion 85 is formed in the guide cap 70E. Note that the convex portion 46 is formed to be narrower than that of the fifth embodiment.

[0133] In the case of this embodiment, the opposing surfaces of the pair of convex bases 86, 86 projecting from the inner surface of the elastic piece portion 77 of the guide cap 70E (forming both inner surfaces of the concave portion 85), and both inner surfaces of the concave portion 85 are provided with inclined surfaces 87e, 87e that form a convex curved surface that is convex toward the guide cap 70B side as a whole in an R shape. The pair of inclined surfaces 87e, 87e are the narrowest at the bottom 89 of the concave portion 85. Further, convex curved surfaces 87f, 87f are provided near the opening 88 of the inclined surfaces 87e, 87e.

[0134] It can also be said that inclined surfaces 87e, 87e are provided on both inner surfaces of the concave portion 85 from the opening 88 side to the bottom 89 side of the concave portion 85, and it can also be said that the inclined surfaces 87e, 87e have a shape that becomes narrower from the opening 88 side to the bottom 89 side of the concave portion 85. Further, as the inclined surface, it may have a shape in which the bottom 89 is wider than the minimum distance (the length between the vertices that project to the maximum extent on the opposite side of the pair of opposed inclined surfaces 87g, 87g) like the inclined surfaces 87g, 87g shown by the two-dot chain line in FIG. 27.

[0135] Then, as shown in Fig. 27, the convex surface 53 of the convex portion 46 that has entered the concave portion 85 is configured to abut against the R-shaped convex surfaces 87f, 87f of the pair of inclined surfaces 87e, 87e in the concave portion 85, respectively (a structure in which the convex surfaces abut against each other at two locations). In this way, since the convex surface 53 of the convex portion 46 abuts against the convex surfaces 87f, 87f of the inclined surfaces 87e, 87e of the concave portion 85 at two locations, the same operational effects as those of the third to fifth embodiments can be obtained.

[0136] (Modification Example of Damper Device) Figs. 28(a) to (d) show modification examples of the third to sixth embodiments of the damper device according to the present invention.

[0137] The first modification example shown in Fig. 28(a) has substantially the same shape as the fourth embodiment shown in Figs. 20 and 21, but the shape of the convex portion 79 provided on the guide cap side is different. That is, this convex portion 79 has a shape in which inclined surfaces 84, 84 having a tapered surface shape that gradually reduces in diameter toward the top portion 84a are provided on its outer surface.

[0138] Then, the pair of tapered inclined surfaces 84, 84 of the convex portion 79 that has entered the concave portion 55 are configured to abut against the R-shaped convex surfaces 56d, 56d of the pair of inclined surfaces 56c, 56c in the concave portion 55, respectively (a structure in which the convex surface and the tapered surface abut against each other at two locations).

[0139] The second modification example shown in Fig. 28(b) has substantially the same shape as the sixth embodiment shown in Figs. 25 to 27, but the shape of the convex portion 46 provided on the rod side is different. That is, this convex portion 46 has a shape in which inclined surfaces 54, 54 having a tapered surface shape that gradually reduces in diameter toward the top portion 54a are provided on its outer surface.

[0140] Then, the pair of tapered inclined surfaces 54, 54 of the convex portion 46 that has entered the concave portion 85 are configured to abut against the R-shaped convex surfaces 87f, 87f of the pair of inclined surfaces 87e, 87e in the concave portion 85, respectively (a structure in which the convex surface and the tapered surface abut against each other at two locations).

[0141] The third modification example shown in Fig. 28(c) has substantially the same shape as the third embodiment shown in Figs. 17 to 19, but the shape of the recess 55 provided on the rod side is different. That is, in this recess 55, the inclined surfaces 56, 56 on both inner surfaces thereof are in a concave curved surface shape.

[0142] And the convex curved surface 80 of the convex portion 79 that has entered the recess 55 is in contact with the pair of inclined surfaces 56, 56 having a concave curved surface shape of the recess 55, respectively (a structure in which the convex curved surface and the concave curved surface are in contact at two locations).

[0143] The fourth modification shown in Fig. 28(d) has substantially the same shape as the fifth embodiment shown in Figs. 22 to 24, but the shape of the recess 85 provided on the guide cap side is different. That is, in this recess 85, the inclined surfaces 87, 87 on both inner surfaces thereof are in a concave curved surface shape.

[0144] And the convex curved surface 53 of the convex portion 46 that has entered the recess 85 is in contact with the pair of inclined surfaces 87, 87 having a concave curved surface shape of the recess 85, respectively (a structure in which the convex curved surface and the concave curved surface are in contact at two locations).

[0145] Moreover, the present invention is not limited to the above-described embodiments, and various modified embodiments are possible within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention.

Explanation of Reference Numerals

[0146] 10 Damper device 20 Cylinder 21 Wall portion 23 Opening 23a Engagement hole 30 Piston rod 40, 40A, 40B, 40C, 40D, 40E Rod 45 Rib 45a Standing portion 46 Convex portion 47 Rod-side guide portion 49 Rod-side concave groove 50 Concave curved surface 52 Rod-side rib 53 Convex surface 55 Concave part 56, 56c Inclined surface 57 Opening 58 Bottom 60 Piston 70, 70A, 70B, 70C, 70D, 70E Guide cap 71 Insertion wall part 73 Insertion hole 73a Insertion groove 76 Engagement claw 77 Elastic piece part 78 Guide part on cap side 79 Convex part 80 Convex surface 82 Convex base 83 Concave surface 85 Concave part 86 Convex base 87 Inclined surface 88 Opening 89 Bottom

Claims

1. A damper device attached between a pair of members that approach and separate from each other, and that applies a braking force when the pair of members approach or separate, a cylinder having an opening at one end, a piston rod movably inserted into the cylinder through the opening, and a guide cap attached to the opening of the cylinder, wherein the piston rod has a rod and a piston connected to the rod, the cylinder has a cylindrical wall portion, and a cross-section of the wall portion orthogonal to the moving direction of the piston has a shape having a major axis and a minor axis, the piston has a shape having a major axis and a minor axis so as to conform to the inner circumference of the wall portion of the cylinder, when viewed from the axial direction, the rod has a major axis along the major axis direction of the piston and a minor axis orthogonal thereto, and is plate-shaped and extends a predetermined length, the guide cap has an insertion wall portion inserted inside the opening of the cylinder, an insertion hole into which the rod is inserted, and an elastically deformable elastic piece portion provided at a portion of the insertion wall portion facing the rod, between the rod and the elastic piece portion, a convex portion is formed on one of the rod or the elastic piece portion, and a concave portion into which the convex portion enters and abuts is formed on the other, the convex portion or the concave portion provided on the rod extends in the axial direction and is configured to guide the axial movement of the piston rod, at least one of the convex portion side or the concave portion side of the contact portion between the convex portion and the concave portion is a curved surface, the convex portion has a convex curved surface that forms the curved surface, the concave portion has a concave curved surface that forms the curved surface, and the convex curved surface and the concave curved surface are in contact, the convex portion projects from the elastic piece portion, and the convex curved surface is provided at the top thereof, a rod-side concave groove forming the concave portion extends along the axial direction of the rod, and the concave curved surface is provided on the inner surface of the rod-side concave groove, A damper device, wherein when the radius of curvature of the concave curved surface with respect to the axis of the rod is R1 and the radius of curvature of the convex curved surface with respect to the axis of the guide cap is R2, R1 > R2.

2. A damper device attached between a pair of members that approach and separate from each other, and that applies a braking force when the pair of members approach or separate, a cylinder having an opening at one end, A piston rod movably inserted into the cylinder through the opening, And a guide cap attached to the opening of the cylinder, The piston rod has a rod and a piston connected to the rod, The cylinder has a cylindrical wall portion, and a cross section of the wall portion perpendicular to the moving direction of the piston has a shape with a major axis and a minor axis, The piston has a shape with a major axis and a minor axis so as to fit the inner circumference of the wall portion of the cylinder, The rod has a major axis along the major axis direction of the piston and a minor axis perpendicular thereto when viewed from the axial direction, and has a plate shape extending with a predetermined length, The guide cap has an insertion wall portion inserted inside the opening of the cylinder, an insertion hole into which the rod is inserted, and an elastically deformable elastic piece portion provided at a portion of the insertion wall portion facing the rod, Between the rod and the elastic piece portion, a convex portion is formed on one of the rod or the elastic piece portion, and a concave portion into which the convex portion enters and abuts is formed on the other, The convex portion or the concave portion provided on the rod extends in the axial direction and is configured to guide the axial movement of the piston rod, At least one of the convex portion side or the concave portion side of the contact portion between the convex portion and the concave portion forms a curved surface, The convex portion has a convex curved surface forming the curved surface, the concave portion has a concave curved surface forming the curved surface, and the convex curved surface and the concave curved surface are in contact, On the rod, a rod-side protrusion forming the convex portion extends along its axial direction, and the convex curved surface is provided at the top of the rod-side protrusion, On the elastic piece portion, a convex-shaped base portion protrudes, and the concave curved surface is provided at the top thereof, A damper device characterized in that when the radius of curvature of the convex curved surface with respect to the axis of the rod is R3 and the radius of curvature of the concave curved surface with respect to the axis of the guide cap is R4, R3 < R4.

3. A damper device attached between a pair of members approaching and separating from each other, and applying a braking force when the pair of members approach or separate, A cylinder provided with an opening at one end, A piston rod movably inserted into the cylinder through the opening, And a guide cap attached to the opening of the cylinder, The piston rod has a rod and a piston connected to the rod. The cylinder has a cylindrical wall portion, and a cross section of the wall portion perpendicular to the moving direction of the piston has a shape having a major axis and a minor axis. The piston has a shape having a major axis and a minor axis so as to fit the inner circumference of the wall portion of the cylinder. When viewed from the axial direction, the rod has a major axis along the major axis direction of the piston and a minor axis perpendicular thereto, and has a plate shape extending by a predetermined length. The guide cap has an insertion wall portion inserted inside the opening of the cylinder, an insertion hole into which the rod is inserted, and an elastically deformable elastic piece portion provided at a portion of the insertion wall portion facing the rod. Between the rod and the elastic piece portion, a convex portion is formed on one of the rod or the elastic piece portion, and a concave portion into which the convex portion enters and abuts is formed on the other. The convex portion or the concave portion provided on the rod extends in the axial direction and is configured to guide the axial movement of the piston rod. At least one of the convex portion side or the concave portion side of the contact portion between the convex portion and the concave portion forms a curved surface. The convex portion has a convex curved surface forming the curved surface, the concave portion has a concave curved surface forming the curved surface, and the convex curved surface and the concave curved surface are in contact with each other. On both sides of the elastic piece portion, a pair of cap-side guide portions protruding so as to face the surface of the rod along the major axis direction are provided. The elastic piece portion is disposed at a position separated from the rod more than the protruding surfaces of the pair of cap-side guide portions, and one of the convex curved surface or the concave curved surface is provided on the elastic piece portion. The rod is disposed to face the pair of cap-side guide portions, and has a pair of rod-side guide portions extending in the axial direction and a protrusion portion protruding to the guide cap side more than the protruding surfaces of the pair of rod-side guide portions and entering between the pair of cap-side guide portions and extending in the axial direction. The damper device is characterized in that the other of the convex curved surface or the concave curved surface is provided on the protrusion portion.

4. A damper device attached between a pair of members approaching and separating from each other, and applying a braking force when the pair of members approach or separate, A cylinder having an opening at one end, A piston rod movably inserted into the cylinder through the opening, And a guide cap attached to the opening of the cylinder, The piston rod has a rod and a piston connected to the rod, The cylinder has a cylindrical wall portion, and a cross section of the wall portion perpendicular to the moving direction of the piston has a shape with a major axis and a minor axis, The piston has a shape with a major axis and a minor axis so as to fit the inner circumference of the wall portion of the cylinder, When viewed from the axial direction, the rod has a major axis along the major axis direction of the piston and a minor axis perpendicular thereto, and has a plate shape extending a predetermined length, The guide cap has an insertion wall portion inserted inside the opening of the cylinder, an insertion hole into which the rod is inserted, and an elastically deformable elastic piece portion provided at a portion of the insertion wall portion facing the rod, Between the rod and the elastic piece portion, a convex portion is formed on one of the rod or the elastic piece portion, and a concave portion into which the convex portion enters and abuts is formed on the other, The convex portion or the concave portion provided on the rod extends in the axial direction and is configured to guide the axial movement of the piston rod, At least one of the convex portion side or the concave portion side of the contact portion between the convex portion and the concave portion has a curved surface, From both sides of the surface of the rod along the major axis, ribs standing upright in a direction perpendicular to the surface along the major axis and extending in the axial direction are provided. A standing portion that stands higher than other portions is provided at a portion of the rib located on the piston side. The standing portion is configured to be able to contact the inner peripheral surfaces of both ends of the insertion hole of the guide cap, The guide cap is formed with insertion grooves into which the ribs of the rod are inserted at both ends of the insertion hole, and engaging claws that engage from the inner circumference are formed in a bendable manner in an engaging hole provided in the opening of the cylinder. The engaging claws are disposed at positions corresponding to the outside of the standing portion. A damper device characterized by this.

5. A damper device attached between a pair of members that approach and separate from each other, and applies a braking force when the pair of members approach or separate, A cylinder having an opening at one end, A piston rod movably inserted into the cylinder through the opening, It has a guide cap mounted on the opening of the cylinder. The piston rod has a rod and a piston connected to the rod. The cylinder has a cylindrical wall portion, and a cross-section of the wall portion perpendicular to the moving direction of the piston has a shape with a major axis and a minor axis. The piston has a shape with a major axis and a minor axis so as to fit the inner circumference of the wall portion of the cylinder. When viewed from the axial direction, the rod has a major axis along the major axis direction of the piston and a minor axis perpendicular thereto, and has a plate shape extending a predetermined length. The guide cap has an insertion wall portion inserted inside the opening of the cylinder, an insertion hole into which the rod is inserted, and an elastically deformable elastic piece portion provided at a portion of the insertion wall portion facing the rod. Between the rod and the elastic piece portion, a convex portion is formed on one of the rod or the elastic piece portion, and a concave portion into which the convex portion enters and abuts is formed on the other. The convex portion or the concave portion provided on the rod extends in the axial direction and is configured to guide the axial movement of the piston rod. At least one of the convex portion side or the concave portion side of the contact portion between the convex portion and the concave portion forms a curved surface. On both inner surfaces of the concave portion, inclined surfaces extending from the opening side of the concave portion toward the bottom are provided. The convex portion abuts on the inclined surfaces of the concave portion at two locations. A damper device, characterized in that at least one of the convex portion side or the inclined surface side of the concave portion of the contact portion between the convex portion and the inclined surface of the concave portion forms a convex curved surface that forms the curved surface.

6. From both sides of the surface of the rod along the major axis, ribs are provided that stand perpendicular to the surface along the major axis and extend in the axial direction. The damper device according to claim 3, wherein a groove extending along the axial direction is formed between the rib and the rod-side guide portion on the surface of the rod along the major axis.

Images