WO2019188810A1

WO2019188810A1 - Damper

Info

Publication number: WO2019188810A1
Application number: PCT/JP2019/012155
Authority: WO
Inventors: 加藤　幸一
Original assignee: 株式会社パイオラックス
Priority date: 2018-03-28
Filing date: 2019-03-22
Publication date: 2019-10-03
Also published as: JP6961801B2; JPWO2019188810A1

Abstract

Provided is a damper which can inhibit upsizing of the damper and in which a piston can be easily returned to a predetermined position in a cylinder. This damper (10) comprises: a cylinder (20); a rod (30); and a piston (50) that is made of an elastic resin material and that is attached to the rod (30). The rod (30) includes a second engagement part (37) which engages with the piston (50) when moving in a return direction which is opposite to a damper braking direction. An air circulation groove (62) is formed between the outer circumference of the rod (30) and the inner circumference of the piston (50), and the piston (50) has a slit (55) formed from one end located opposite to the damper braking direction side toward the other end located on the damper braking direction side, so as to be connected to the air circulation groove (62).

Description

Damper

The present invention relates to a damper used for braking such as opening / closing operation of an automobile glove box.

For example, in a glove box of an automobile, a damper may be used in order to prevent the lid from opening suddenly and open it gently.

As such a damper, the following Patent Document 1 discloses a cylinder, a rod inserted into the cylinder, a piston provided on the rod proximal end side and provided with an air flow passage, and a buffer fixed on the rod distal end side. A damper is described having a member and a cap mounted on the proximal opening of the cylinder. A spring is interposed inside the buffer member and is biased so that the buffer member protrudes from the opening at the tip of the cylinder. A cylindrical wall having an elongated cylindrical shape is formed inside the cylinder, a rod is inserted into the cylindrical wall, and an annular gap is formed between the inner periphery of the cylindrical wall and the outer periphery of the rod. Yes. Furthermore, a recess having a predetermined length is formed in a space in the inner periphery of the cylinder where the piston is disposed (see FIG. 4).

When the buffer member is pushed and pulled into the opening at the tip of the cylinder, the buffer member protrudes from the cylinder tip opening by the biasing force of the spring when the pressing force to the buffer member is not applied. At this time, the buffer member is braked by the frictional force between the piston and the inner circumference of the cylinder, and the resistance when the air flows through the air gap of the piston between the inner circumference of the cylindrical wall and the outer circumference of the rod. Is done. In addition, when the buffer member is pushed from a state where it protrudes from the opening at the tip of the cylinder and the buffer member moves to the return direction side opposite to the braking direction, the air in the cylinder is It flows through the annular gap between the outer periphery of the rod, the air flow passage of the piston, and between the piston and the recess provided in the inner periphery of the cylinder, and is released from the cap opening to release the braking force, and the buffer member It is accommodated in the tip opening of the cylinder.

European Patent Application No. 1260159 (EP 1260159A2)

In recent years, downsizing of dampers is desired for reasons such as reducing the installation space of dampers. Further, in the damper, it is preferable that when the piston moves in the return direction opposite to the braking direction, the resistance returns smoothly with little resistance.

Here, the damper of the above-mentioned Patent Document 1 reduces the return resistance by allowing air to flow through a recess formed in the inner periphery of the cylinder when the piston moves in the return direction. In this case, if the cross-sectional area of the recess is increased, the return resistance can be further reduced. However, since the recess is formed on the inner periphery of the cylinder, it is necessary to increase the outer diameter of the cylinder, which may increase the size of the damper. is there.

Therefore, an object of the present invention is to provide a damper that can easily return the piston to a predetermined position of the cylinder and can suppress an increase in size.

In order to achieve the above object, the present invention is a damper that is attached between a pair of members that are close to and away from each other, and that applies a braking force when both members are close to or separate from each other. A cylindrical cylinder, a rod that is inserted movably through the opening of the cylinder, and an elastic resin material that extends in a predetermined length along the axial direction of the rod and is mounted so as to surround the rod A piston, and the rod has an engaging portion that engages with the piston when the rod moves in a return direction opposite to the damper braking direction, and the piston has a damper braking direction. A notch is provided from one end on the opposite side to the other end on the damper braking direction side.

According to the present invention, the piston is provided with a notch from one end opposite to the damper braking direction to the other end of the damper braking direction side. When moving in the opposite return direction, the closed incision is pushed open by the air pressure, making it easier for the air between the cylinder and the piston to escape, so that the piston is in the return direction of the damper It is possible to reduce the resistance when moving to the piston and to easily return the piston, and it is possible to suppress the increase in size of the cylinder and the piston.

It is a disassembled perspective view which shows one Embodiment of the damper which concerns on this invention. The rod which comprises the damper is shown, (a) is the perspective view, (b) is a top view, (c) is a side view. The piston which comprises the damper is shown, (a) is the perspective view, (b) is a perspective view at the time of seeing from the direction different from (a). The piston which comprises the damper is shown, (a) is a top view, (b) is a side view, (c) is sectional drawing in the AA arrow line of (a), (d) is (b) FIG. 6E is a cross-sectional view taken along the line BB of FIG. 6B, and FIG. In the piston which comprises the damper, it is a perspective view which shows a state when a rod moves to the return direction on the opposite side to the braking direction of a damper. The cap which comprises the damper is shown, (a) is the assembly perspective view, (b) is an exploded perspective view. The use state of the damper is shown, (a) is an explanatory view of the state where the rod is stationary, (b) is an explanatory view of the state where the braking force of the damper is applied. It is an explanatory view of a state where the use state of the damper is shown and the braking force of the damper is released. It is a principal part expansion explanatory view of the damper. (A) is a principal part expanded sectional view in the state where a rod stopped still, (b) is a principal part expansion explanatory view explaining a pressure contact state of a piston to a cylinder inner circumference in (a). (A) is a principal part expanded sectional view of the state which the rod moved to the damper braking direction, (b) is a principal part expansion explanatory view explaining the pressure contact state of the piston with respect to the cylinder inner periphery in (a). (A) is a principal part expanded sectional view of the state which the rod moved to the return direction on the opposite side to the braking direction of a damper, (b) is the principal part explaining the press-contact state of the piston with respect to a cylinder inner periphery in (a). FIG. 12 shows a state where the piston has returned from the contracted state shown in FIG. 12, (a) is an enlarged cross-sectional view of the main part, and (b) explains the pressure contact state of the piston against the inner circumference of the cylinder in (a). FIG. It is principal part expansion explanatory drawing of the damper which made the braking direction of the damper reverse with respect to the damper of the said embodiment.

Hereinafter, a first embodiment of a damper according to the present invention will be described with reference to the drawings.

A damper 10 shown in FIG. 1 is attached to a pair of members that are close to and away from each other, and applies a braking force when the pair of members approaches or separates. For example, the damper 10 is provided on an instrument panel of an automobile. It can be used for braking, such as a glove box and a lid, which are attached to the opening of the accommodating portion so as to be opened and closed. In the following embodiments, one member is a fixed body such as an instrument panel housing, and the other member is attached to the opening of the fixed body so as to be openable and closable, such as a glove box and a lid. Although described as an openable / closable body, the pair of members is not particularly limited as long as they are close to and away from each other.

As shown in FIG. 1, the damper 10 of this embodiment is mounted on a cylinder 20 having a substantially cylindrical shape, a rod 30 movably inserted into the cylinder 20, and an axially distal end side of the rod 30. The piston 50 is made of an elastic resin material, and the cap 80 is attached to the opening 22 of the cylinder 20.

As shown in FIGS. 1 and 7, the cylinder 20 of this embodiment has a substantially cylindrical wall portion 21 extending at a predetermined length, and one end side in the axial direction is opened to form an opening portion 22. ing. Further, the other end side of the wall portion 21 is closed by an end portion wall 23. An annular mounting portion 24 is provided outside the end wall 23, and the cylinder 20 is attached to one member such as an instrument panel via the mounting portion 24. . Furthermore,

circular fitting holes

25, 25 are formed on one end side of the wall portion 21 so as to oppose each other in the circumferential direction (see FIG. 1). Note that a cap provided with an orifice may be attached by opening the other end side of the wall portion 21, and a mounting portion may be provided at a predetermined axial position on the outer periphery of the wall portion 21. Moreover, it is preferable that the outer diameter of the cylinder 20 is 12 mm or less, and it is more preferable that it is 8 mm or less.

As shown in FIGS. 6 (a) and 6 (b), the cap 80 in this embodiment has a pair of

halves

81, 81 in the form of a half cylinder. They are integrated by engaging with each other via a locking piece 88 and a locked portion 90 locked to the locking piece 88. Each halved body 81 is provided with a flange portion 83 on the outer periphery of the base end thereof, and a fitting protrusion 84 is provided on the outer periphery in the axial direction. The cap 80 is inserted into the opening 22 of the cylinder 20 from the distal end side thereof, and the flanges 83 are locked to the base end surface of the cylinder 20 and the fitting protrusions 84 are fitted to the cylinder 20. By fitting into the

holes

25, 25, the cylinder 20 is mounted on the base end side (see FIGS. 7 and 8).

The rod 30 is inserted into the cylinder 20 through the opening 22 of the cylinder 20 so as to be movable from the tip side thereof, and is connected to a columnar shaft portion 31 and the tip side thereof. And a piston mounting portion 32 to which the piston 50 is mounted. An annular attachment portion 33 is provided on the proximal end side of the shaft portion 31, and the rod 30 is attached to the other member such as a glove box via the attachment portion 33. Yes.

Referring also to FIGS. 2 (a) to 2 (c), the piston mounting portion 32 is provided at the foremost end of the rod 30 in the axial direction, and includes a first engagement portion 34 having a substantially disc shape, The first engagement portion 34 has a stopper portion 35 provided at a predetermined interval on the rod proximal end side.

The first engaging portion 34 is a portion that engages with the piston 50 as shown in FIG. 11 when the rod 30 moves in a braking direction in which the damper applies a braking force (see FIG. 11). Here, the first engaging portion 34 is engaged with one end side of the piston 50). Note that the braking direction of the damper in this embodiment means that the first engagement portion 34 is separated from the end wall 23 (see FIG. 7) of the cylinder 20 and the rod 30 is pulled out from the opening 22 of the cylinder 20. Means an increasing direction (see arrow F1 in FIGS. 7, 10 and 11).

Further, the stopper portion 35 has a substantially circular protrusion shape as a whole, and cut

portions

35a, 35a formed by cutting wall portions at positions on the first engagement portion 34 side on both sides in the circumferential direction. Are formed respectively. Each cut portion 35a is provided with a flat surface continuous with the flat surface 40 provided on the second column portion 39 described later (see FIG. 2A). The first engaging portion 34 and the stopper portion 35 are formed so that the outer diameter is larger than the inner diameter of the piston 50, and the distance between the first engaging portion 34 and the stopper portion 35 is the distance of the piston 50. It is formed longer than the axial length, and the piston 50 is mounted between the first engaging portion 34 and the stopper portion 35 so as to be extendable and contractable in the axial direction.

Further, the piston mounting portion 32 is connected to the substantially columnar first column portion 36 extending from the inner surface side of the first engagement portion 34 toward the rod proximal end side, and the extending direction distal end of the first column portion 36. And a second engagement that engages with the piston 50 when the rod 30 moves in the return direction opposite to the braking direction of the damper (see arrow F2 in FIGS. 12 and 13). A second column portion 39 having a substantially cylindrical shape extending from the proximal end side of the portion 37 and the second engagement portion 37 to the proximal end side of the rod via the recess 38 and connected to the stopper portion 35. And have.

In this embodiment, the return direction (hereinafter also simply referred to as “return direction”) opposite to the braking direction of the damper means that the first engagement portion 34 is placed on the end wall 23 of the cylinder 20 (see FIG. 7). This means that the rod 30 moves in the direction in which the pushing amount of the rod 30 into the cylinder 20 increases (see arrow F2 in FIGS. 8, 12 and 13).

Further, as shown in FIGS. 9, 12 (a), and 13 (a), the second engagement portion 37 is arranged on the return direction side of the damper from the press contact portion 53 described later of the piston 50. Yes. Further, the second engagement portion 37 and the second column portion 39 are larger in diameter than the first column portion 36 and smaller in diameter than the first engagement portion 34 and the stopper portion 35, and the first column The second pillar portion 39 is formed longer than the portion 36.

In this embodiment, when the rod 30 moves in the return direction of the damper, as shown in FIGS. 12 (a) and 13 (a), the second engagement portion 37 will be described later of the piston 50. It engages with the engaged portion 61. That is, the “engagement portion” of the rod in the present invention means the second engagement portion 37. Further, when the rod 30 further moves in the return direction of the damper from the state shown in FIG. 12, the piston 50 in the state of being contracted in the axial direction and pressed against the inner periphery of the cylinder is elastically returned to the extended state. However, as shown in FIG. 13, in the state where the piston 50 extends the longest, the stopper portion 35 abuts on the other end side of the piston 50 and the movement of the piston 50 is restricted. It has become so.

Further, as shown in FIG. 2 (a), the outer periphery of the first engaging portion 34, the stopper portion 35, the first column portion 36, and the second column portion 39, and at two locations in the circumferential direction thereof. The flat surfaces 40, 40, which are cut in a planar shape along the axial direction of the rod 30, are formed so as to be parallel to each other. The flat surface 40 formed on the second pillar portion 39 is flush with the flat surfaces of the

cut portions

35a and 35a provided on the stopper portion 35. The flat surface 40 forms a gap with respect to the inner periphery of the cylinder 20 and the inner periphery of the piston 50.

Further, as shown in FIG. 2 (a), the protrusion 41 that contacts the inner periphery of the piston 50 extends in the axial direction from the second engagement portion 37 side to the proximal end side of the rod 30, and A plurality are formed side by side at a predetermined interval in the circumferential direction. Specifically, in this embodiment, as shown in FIG. 2C, protrusions extending along the axial direction of the rod 30 on the outer periphery of the second column portion 39 on both sides of the flat surface 40 in the circumferential direction. The

ridges

41 and 41 are projected in a length extending from the distal end portion of the rod 30 closer to the second engagement portion 37 to the front portion of the stopper portion 35 (in this embodiment, the ridges are provided at a total of four ridges). 41). By this protrusion 41, a gap is formed between the inner periphery of the piston 50 and the outer periphery of the second column portion 39.

Further, as shown in FIG. 2A and FIG. 2B, the groove portion 43 is formed at a predetermined depth along the axial direction of the first column portion 36 from one circumferential direction on the inner surface of the first engagement portion 34. Is formed. As shown in FIG. 2B, the groove 43 is provided between the

flat surfaces

40 and 40 provided in the first engagement portion 34 and in the middle thereof. As shown in FIG. 11A, even when one end surface of the piston 50 is in contact with the inner surface of the first engagement portion 34 by the groove portion 43, the inner surface of the first engagement portion 34 and one of the pistons 50 are A gap can be secured between the end face and a gap can be secured between the outer periphery of the first column portion 36 and the inner periphery of the engaged portion 61 of the piston 50 (see FIG. 4C). It has become.

Further, an inclined portion 44 that is gradually reduced in diameter toward the proximal end side of the rod 30 is formed on the outer periphery on the distal end side of the shaft portion 31, that is, on the outer periphery of the connecting portion between the shaft portion 31 and the stopper portion 35. . Further, an inclined portion 45 having a diameter gradually reduced toward the proximal end side of the rod 30 is also formed on the outer periphery on the distal end side of the first column portion 36.

In addition, as described above, the rod 30 having the above structure is inserted into the cylinder 20 from the first engaging portion 34 side at the tip and is disposed so as to be movable in the cylinder 20. 7 and FIG. 8, the first chamber R1 of the rod 30 located on the return direction side of the damper with the first engagement portion 34 of the rod 30 as a boundary, and the braking direction side of the damper of the rod 30 And a second chamber R2 positioned at the same position. In this embodiment, a first chamber R 1 is formed on the end wall 23 side of the cylinder 20, and a second chamber R 2 is formed on the opening 22 side of the cylinder 20. The rod 30 described above includes the shaft portion 31, the attachment portion 33, the first engagement portion 34, the stopper portion 35, the second engagement portion 37, the other first pillar portion 36, and the second pillar portion 39. The plurality of protrusions 41 and the like are all integrally formed.

Next, referring to FIGS. 3 to 5, the rod 30 is attached to the base end side of the first engagement portion 34 of the rod 30 so as to surround the rod 30 along the axial direction of the rod 30. The piston 50 made of an elastic resin material will be described. The piston 50 is made of, for example, a rubber elastic material such as rubber or elastomer, or a resin material such as sponge. When the piston 50 is compressed in the axial direction, the diameter is increased and the piston 50 is pulled in the axial direction. In some cases, the diameter is reduced. The piston 50 follows the rod 30 when moving in the braking direction of the damper and moves in the braking direction of the damper. On the other hand, the piston 50 also follows when the rod 30 moves in the returning direction of the damper. Move in the return direction of the damper.

The piston 50 of this embodiment has a main body 51 that extends in a predetermined length so as to form a substantially cylindrical shape, and whose outer periphery has a circumferential shape. The outer periphery of one end 52 (the end located on the first engagement portion 34 side when the piston 50 is attached to the rod 30) of the main body 51 on the side opposite to the braking direction of the damper is It has a tapered shape that gradually decreases in diameter toward one end surface in the axial direction.

Further, the outer periphery of the other end portion of the main body 51 on the braking direction side of the damper (the end portion positioned on the stopper portion 35 side in a state where the piston 50 is attached to the rod 30) is always on the inner periphery of the cylinder 20. A pressure contact portion 53 is provided for applying a braking force to the piston 50 when the rod 30 is moved in pressure contact (both in the movement direction of the damper and in the return direction of the damper).

In the following description, one end or one end of the piston on the opposite side to the braking direction of the damper is simply referred to as “one end” or “one end”, and the other end or the other end on the braking direction side of the damper is defined as the piston. This will be described simply as “the other end” or “the other end”.

Further, as shown in FIG. 4C and FIG. 4D, the outer periphery of the piston 50 has a tapered shape in which the diameter increases from one end side to the other end side of the piston 50. In this embodiment, the outer periphery of the main body 51 constituting the piston 50 is formed in a tapered shape in which the diameter gradually increases from the other end side of the tapered one end portion 52 toward the press contact portion 53.

Furthermore, a cutout portion 54 extending in the axial direction is formed on the outer periphery of the main body 51 from the other end side of the tapered one end portion 52. The notch 54 forms an air escape path between the inner circumference of the cylinder and the outer circumference of the piston (the main body 51 and the press-contact portion 53) to facilitate the expansion and contraction of the piston 50, and the damper control by the piston 50. It is intended to adjust the power. As shown in FIG. 4E, the notch 54 has a shape obtained by cutting a part of the circumference of the outer periphery of the main body 51 in one plane when the piston 50 is viewed from the axial direction. And formed so as to be parallel to each other at two locations in the circumferential direction of the main body 51. Further, as shown in FIG. 3, the notch portion 54 in this embodiment is formed so as to penetrate the pressure contact portion 53 in the axial direction and reach the other end of the main body 51. By providing such a notch 54, between the outer periphery of the main body 51 from the press-contact part 53 to one end side and the inner periphery of the cylinder 20 in a state where the braking force of the damper is not acting. A gap is formed. Further, since the notched portion 54 is formed in the press contact portion 53, the notch portion 54 of the press contact portion 53 can be used when the rod 30 or the piston 50 is stationary, when the damper is braked, or when the damper is released. A gap is formed between the inner periphery of the cylinder 20 and the inner periphery of the cylinder 20.

The notch 54 in this embodiment is formed from the other end of the one end 52 of the main body 51 to the other end of the main body 51, but the one end 52 of the main body 51 is tapered. If not, the notch may be formed from one end of the main body 51 to the other end. However, the notch may be formed from one end of the main body 51 to the middle in the axial direction, or may not be formed on the outer periphery of the main body 51, and may be provided only on the pressure contact portion 53 on the other end side of the main body 51.

Further, as shown in FIGS. 3A and 3B, the pressure contact portion 53 in this embodiment protrudes in the outer diameter direction of the main body 51 of the piston 50 and extends elongated along the circumferential direction of the main body 51. And a pair of annular

convex portions

56, 56 having an annular shape. The pair of annular

convex portions

56, 56 are disposed on the outer periphery of the other end portion of the main body 51 and between the

notches

54, 54 provided at two places in the circumferential direction of the press contact portion 53. (See FIG. 4 (e)). More specifically, each annular convex portion 56 is disposed on the outer periphery of the other end of the main body 51, and a first convex portion 57 extending along the circumferential direction of the main body 51, and a piston with respect to the first convex portion 57. 50 is arranged in parallel at one end side with a predetermined interval, and extends along the circumferential direction of the main body 51, and both circumferential ends of the first convex portion 57 and the second convex portion 58. Are connected to each other. Further, inside the

convex portions

57, 58, 59, a concave portion 60 having a concave groove shape extending at a predetermined depth along the circumferential direction of the main body 51 is provided. Further, the outermost diameters of the respective

convex portions

57, 58, 59 are formed larger than the inner diameter of the cylinder 20, and the respective

convex portions

57, 58, 59 are always pressed against the inner periphery of the cylinder 20. ing.

Further, as shown in FIGS. 4C and 4D, an engaged portion 61 that protrudes annularly along the circumferential direction is provided on the inner periphery of one end side of the main body 51. As shown by the arrow F2 in FIG. 8, the engaged portion 61 is adapted to engage with the second engaging portion 37 of the rod 30 when the rod 30 moves in the return direction of the damper ( FIG. 12 (a)). At this time, as shown in FIG. 12B, a gap is formed between the first engagement portion 34 of the rod 30 and one end of the piston 50.

Further, as shown in FIG. 3B, FIG. 4C, and FIG. 4D, one end of the main body 51 is located on the inner periphery of the main body 51 at a position corresponding to the pair of

notches

54 and 54.

Air flow grooves

62, 62 having a groove shape extending in the axial direction from the first end to the other end side are formed. As shown in FIG. 9, the air flow groove 62 is formed so that the second engagement portion 37 of the rod 30 is engaged with the engaged portion 61 of the piston 50 from one end of the main body 51. The length extends beyond the engagement portion 37 and the recess 38 to reach one end of the second column portion 39. The air flow groove 62 forms a gap between the first column portion 36, the second engagement portion 37, and the outer periphery of one end side of the second column portion 39 of the rod 30, and the rod 30 and the piston. It becomes a part which distribute | circulates air between 50. In addition, the said air circulation groove should just be formed between the outer periphery of the rod 30, and the inner periphery of piston 50, for example, may be formed in the outer peripheral side of a rod.

Further, as shown in FIG. 3 and FIG. 4A, one notch portion 54 provided on the outer periphery of the main body 51 extends across the entire axial direction of the piston 50 from one end of the piston 50 to the other end. A cut 55 is formed. As shown in FIG. 4D and FIG. 4E, the notch 55 communicates with one of the

air flow grooves

62 and 62 formed on the inner periphery of the piston 50. Yes. When the piston 50 moves in the braking direction of the damper, the notch 55 is closed because the inside of the air circulation groove 62 is depressurized (see FIG. 7), while the piston 50 is in the return direction of the damper. When moving to, it is configured to be pushed and opened by the air flowing in from the air circulation groove 62 (see FIGS. 5 and 8).

Moreover, since the main body 51 can be separated into two along the axial direction by the notches 55 provided in the main body 51, the piston 50 is mounted on the piston mounting portion 32 from the outer diameter side of the rod 30. It is possible. In addition, the notch 55 may not be formed in the whole area in the axial direction from one end of the main body 51 to the other end, but may be formed in a length extending in the axial direction from one end of the main body 51 to the other end side. .

In a state where the rod 30 and the piston 50 do not move in the braking direction and return direction of the damper and are stationary, that is, in a normal state where the piston 50 does not expand and contract, as shown in FIG. A gap is formed between the engaging portion 34 and one end of the piston 50, and a cut portion 35 a provided in the stopper portion 35 is also provided between the stopper portion 35 of the rod 30 and the other end of the piston 50. Thus, a gap is formed.

In the damper 10 having the above-described configuration, when the damper is braked, the first engaging portion 34 of the rod 30 is in contact with the one end portion 52 of the piston 50 and is always in pressure contact with the inner periphery of the cylinder 20. An axial compression force acts on the piston 50 between the annular

convex portions

56 and 56. That is, as shown in FIG. 10A, in a state where no braking force is applied to the damper, in FIG. 10B, the pair of annular

convex portions

56, 56 of the piston 50 are located on the inner periphery of the cylinder 20. In this state, when the rod 30 moves in the damper braking direction, as shown in FIG. 11A, the first engagement portion 34 comes into contact with the one end portion 52 of the piston 50, and the cylinder 20 The axial compression force acts on the piston 50 between the pressure contact portion 53 and the inner circumference of the cylinder 50, whereby the piston 50 expands in diameter and the amount of pressure contact with the cylinder inner circumference increases. As a result, as shown in FIG. 11 (b), the portion S of the piston 50 that is in pressure contact with the inner periphery of the cylinder 20 (the portion expressed by dotted hatching) is increased, and the friction of the piston 50 against the inner periphery of the cylinder 20 is increased. The force can be increased, and the braking force of the damper can be increased.

In addition, the damper 10 in this embodiment has (1) the flat surface 40 of the first engagement portion 34 of the rod 30 and the inner periphery of the cylinder 20 as a passage for allowing air to pass through the piston 50 in the cylinder 20. (2) a clearance between the first engagement portion 34 of the rod 30 and one end of the piston 50, (3) a clearance between the groove portion 43 of the rod 30 and the inner periphery of the piston 50, and (4) an outer periphery of the rod 30 and the piston. 50, the clearance between the recess 30 of the rod 30 and the inner periphery of the piston 50, and (6) the clearance between the second column portion 39 of the rod 30 and the inner periphery of the piston 50. (7) A clearance between the cut portion 35a of the stopper portion 35 of the rod 30 and the other end of the piston 50, and (8) a clearance between the flat surface 40 of the stopper portion 35 of the rod 30 and the inner periphery of the cylinder 20 are provided. There.

As shown in FIG. 9, when the rod 30 is stationary and no damper braking force is applied, the clearances (1) to (8) are secured. Further, as shown in FIG. 11, when the rod 30 moves in the damper braking direction, the first engagement portion 34 of the rod 30 abuts on one end of the piston 50, so that the gap (2) is eliminated. However, the gaps (1) and (3) to (8) are secured. Further, as shown in FIG. 12, when the rod 30 moves in the return direction of the damper, the first engaging portion 34 of the rod 30 is separated from the one end of the piston 50 again, so that the above (1) to (8) A gap is secured.

Moreover, in this damper 10, when it switches from the state in which the damper was braked to the state in which the braking force of the damper is released, that is, as shown in FIG. 11, an axial compression force acts on the piston 50, When the rod 50 moves in the return direction of the damper from the state in which the piston 50 expands and the frictional force on the inner circumference of the cylinder 20 increases, the piston 50 is moved to a predetermined position by the following operation. Easy to return. That is, when the rod 30 moves in the return direction of the damper from the state shown in FIG. 11, the second engaging portion 37 of the rod 30 is engaged with the engaged portion 61 of the piston 50. By applying an axial tensile force to the piston 50, one end side of the piston 50 is extended with respect to the other end side restricted by the press contact portion 53, and the diameter of the piston 50 is reduced to the original shape. (See FIG. 13). As a result, the frictional force of the piston 50 with respect to the inner periphery of the cylinder 20 can be reduced, and the piston 50 can be easily returned.

Next, the function and effect of the damper 10 having the above configuration will be described.

That is, in this damper 10, the other member such as the opening / closing body opens with respect to one member such as the instrument panel, and the rod 30 moves in the braking direction of the damper as shown by an arrow F1 in FIG. Then, the first engaging portion 34 abuts on the one end portion 52 of the piston 50 and an axial compressive force acts on the piston 50 between the first contact portion 53 and the piston 50 to expand its diameter to the inner circumference of the cylinder. Since the amount of pressure contact increases, the portion S of the piston 50 that presses against the inner periphery of the cylinder 20 can be increased (see FIG. 11B) to increase the braking force of the damper, and the moving speed of the rod 30 Accordingly, it is possible to obtain the damper 10 having excellent load response characteristics in which the braking force varies according to the above.

On the other hand, from the state in which the rod 30 moves in the damper braking direction and the piston 50 is compressed to increase the amount of pressure contact with the inner periphery of the cylinder (see FIG. 11), When the member is closed and the rod 30 moves in the return direction of the damper as shown by an arrow F2 in FIG. 8, the second engagement portion 37 of the rod 30 engages with the engaged portion 61 of the piston 50 ( As shown in FIG. 12A, the piston 50 is pushed into the return direction side of the damper. At this time, since the pressure contact portion 53 of the piston 50 is in pressure contact with the inner periphery of the cylinder 20, the movement of the other end side of the piston 50 is suppressed and the one end side is pushed away from the other end side. Thus, an axial tensile force acts on the piston 50, and the piston 50 made of an elastic resin material having a reduced diameter is stretched in the axial direction, while the first engaging portion 34 of the rod 30 is The piston 50 moves away from one end side.

Then, as shown by the arrow in FIG. 9, the air in the first chamber R1 passes through the gap between the flat surface 40 of the first engaging portion 34 of the rod 30 and the inner periphery of the cylinder 20 in (1) above. (2) From the gap between the first engagement portion 34 of the rod 30 and one end of the piston 50, the air mainly flows into the gap between the outer periphery of the rod 30 and the air flow groove 62 of the piston 50. As a result, as shown in FIGS. 5 and 8, the cut 55 in the closed state is pushed by air pressure and is gradually pushed from the inner edge side of the cut 55 (in this case, one end side of the piston 50 is opened). The opening between the rod 30 and the inner periphery of the piston 50 can be discharged from the notch 55 to the other end side of the piston 50. it can.

The discharged air can be (7) the gap between the cut portion 35a of the stopper portion 35 of the rod 30 and the other end of the piston 50, or (8) the flat surface 40 of the stopper portion 35 of the rod 30 and the inner circumference of the cylinder 20. Is discharged to the outside of the piston mounting portion 32 of the rod 30. Also, part of the air is (3) the clearance between the groove portion 43 of the rod 30 and the inner periphery of the piston 50, (4) the clearance between the outer periphery of the rod 30 and the air flow groove 62 of the piston 50, and (5 ) Through the clearance between the recess 38 of the rod 30 and the inner periphery of the piston 50, and further through the clearance between the second column portion 39 of the rod 30 and the inner periphery of the piston 50 due to the above (6) protrusion 41, the other end side of the piston 50. Discharged from.

As shown in FIG. 13, the piston 50 that has been reduced in diameter from the expanded state by the rod 30 that moves in the return direction of the damper returns to its original shape by its elastic restoring force. ing.

As described above, in the damper 10, the main body 51 of the piston 50 is provided with the notch 55 from one end opposite to the damper braking direction to the other end of the damper braking direction. Therefore, when the piston 50 moves in the piston return direction, the notch 55 in the closed state is pushed and opened as shown in FIGS. 5 and 8, so that the air between the rod 30 and the piston 50 is discharged. As a result, the resistance when the piston 50 moves in the piston return direction can be reduced, and the piston 50 can be easily returned to the predetermined position of the cylinder 20.

Further, since the notch 55 is provided in the piston 50, when the rod 30 moves in the return direction of the damper, the notch 55 can be opened and an air flow passage can be secured, so the first engaging portion of the rod 30 can be secured. The gap in the axial direction between 34 and the other end of the piston 50 can be reduced. As a result, when the rod 30 moves in the braking direction of the damper, the first engagement portion 34 of the rod 30 can be quickly brought into contact with the other end of the piston 50 to exert a braking force. The idle running distance of the piston 50 at the time of damper braking can be reduced (the responsiveness of the piston 50 at the time of damper braking can be increased, and the play until the damper starts to be braked can be reduced).

Further, as described above, since the piston 50 can be easily returned to the predetermined position, the cylinder 20 and the piston 50 can be prevented from being enlarged, and the damper 10 can be prevented from being enlarged. When the rod 30 moves in the damper braking direction and the piston 50 also moves in the damper braking direction, the notch 55 is closed, so that the pressure contact force of the outer periphery of the piston 50 against the inner periphery of the cylinder 20 is impaired. Since this can be suppressed, the influence on the braking force of the damper can be reduced.

Further, in this embodiment, as shown in FIG. 4 (d), an air circulation groove 62 communicating with the cut 55 is formed between the outer periphery of the rod 30 and the inner periphery of the piston 50. Therefore, when the piston 50 moves in the piston return direction and air enters the air circulation groove 62, the closed cut 55 is pushed and opened as shown in FIGS. The air between 50 can be easily discharged. That is, by providing the air circulation groove 62, the cut 55 in the closed state can be easily opened. As a result, the resistance when the piston 50 moves in the piston return direction can be further reduced, and the piston 50 can be more easily returned to the predetermined position of the cylinder 20. Further, when the rod 30 and the piston 50 move in the damper braking direction, the inside of the air circulation groove 62 is depressurized, so that the cut 55 can be closed smoothly. The reduction of the force can be effectively suppressed, and the influence on the braking force of the damper can be further reduced.

Further, in this embodiment, as shown in FIG. 3 and FIG. 4A, the notch 55 provided in the piston 50 extends from one end of the piston 50 to the other end over the entire axial direction of the piston 50. As shown in FIG. 8, when the piston 50 moves in the piston return direction, the notch 55 can be made easier to open by the air that has entered the air flow groove 62, and the piston 50 is predetermined. It can be made easy to return depending on the position. Further, since the entire piston 50 can be opened in the axial direction through the notch 55, the piston 50 can be easily mounted on the outer periphery of the rod 30 (here, the piston mounting portion 32 of the rod 30).

Further, in this embodiment, as shown in FIGS. 4C and 4D, the outer periphery of the piston 50 (here, the outer periphery of the main body 51) expands from one end side of the piston 50 toward the other end side. It has a tapered taper shape. Therefore, as shown in FIG. 8, when the piston 50 moves in the return direction of the damper, the outer periphery of the portion of the piston 50 where the notch 55 is provided gradually receives the surface pressure from the inner periphery of the cylinder 20. The notch 55 can be easily opened, and the piston 50 can be more easily returned to the predetermined position.

In this embodiment, as shown in FIG. 3 and FIGS. 4 (a) and 4 (d), a notch portion 54 that forms a gap between the outer periphery of the piston 50 and the inner periphery of the cylinder 20. Is formed from one end side to the other end side, and the notch 54 is provided so that the notch 55 is positioned. According to this, by providing the notch 55 in the notch 54 provided on the outer periphery of the piston 50, the sealing performance (adhesiveness to the inner periphery of the cylinder 20) of the piston 50 other than the notch 54 is provided. The incision 55 can be provided without damaging, and the braking force of the damper can be hardly affected.

In this embodiment, when the first engagement portion 34 of the rod 30 moves in a direction away from the end wall 23 of the cylinder 20, a braking force is applied by the damper, and the first engagement portion 34. Is configured so that the braking force by the damper is released when it moves in a direction closer to the end wall 23 of the cylinder 20, on the contrary, the first engaging portion of the rod is When moving in the direction close to the end wall (which also includes the cap attached to the cylinder end), the braking force is applied by the damper, and the braking force is released when moving in the direction away from the end wall. You may comprise as follows.

For example, FIG. 14 shows an enlarged explanatory view of a main part of the damper 10А in which the braking direction of the damper is reversed. This damper 10A is different from the above embodiment in the shape of the rod and the mounting direction of the piston. ing. The rod 30 has a shape in which the first column portion 36 extends longer than the second column portion 39. Further, the piston 50 is disposed on the piston mounting portion 32 of the rod 30 in a state where one end portion 52 thereof faces the stopper portion 35 of the rod 30 and the pressure contact portion 53 of the piston 50 faces the first engagement portion 34 of the rod 30. A piston 50 is mounted, and the mounting direction of the piston 50 is opposite to that of the damper of each of the above embodiments. When the first engaging portion 34 of the rod 30 moves in a direction approaching an end wall (not shown) of the cylinder 20 (not shown), that is, when moved in the direction indicated by the arrow F1 in FIG. Since the stopper portion 35 of the rod 30 abuts on the one end portion 52 of the piston 50 and an axial compressive force acts between the pressure contact portion 53, a braking force by the damper is applied. On the other hand, when the first engagement portion 34 of the rod 30 moves in a direction away from the end wall (not shown) of the cylinder 20, that is, when the first engagement portion 34 moves in the direction indicated by the arrow F2 in FIG. Since the two engaging portions 37 are engaged with the engaged portion 61 of the piston 50 and an axial tensile force is applied to the piston 50, the braking force of the damper is released.

It should be noted that the present invention is not limited to the above-described embodiment, and various modified embodiments are possible within the scope of the present invention, and such an embodiment is also included in the scope of the present invention. .

10, 10A Damper 20 Cylinder 30 Rod 34 Flange part 50 Piston 51 Main body 52 One end part 53 Pressure contact part 54 Notch part 55 Notch 61 Engagement part 62 Air flow groove 80 Cap

Claims

A damper that is attached between a pair of members that are close to and away from each other, and that applies a braking force when both members approach or separate from each other,
A cylindrical cylinder whose end forms an opening, and
A rod movably inserted through the opening of the cylinder;
A piston made of an elastic resin material that extends along the axial direction of the rod at a predetermined length and is mounted so as to surround the rod;
The rod has an engaging portion that engages with the piston when moving in a return direction opposite to the damper braking direction;
The damper, wherein the piston is provided with a cut from one end opposite to the damper braking direction toward the other end of the damper braking direction.
The damper according to claim 1, wherein an air circulation groove communicating with the cut is formed between an outer periphery of the rod and an inner periphery of the piston.
The damper according to claim 1 or 2, wherein the cut is provided over the entire axial direction so as to reach the other end from the one end of the piston.
The damper according to any one of claims 1 to 3, wherein an outer periphery of the piston has a tapered shape whose diameter increases from the one end side toward the other end side of the piston.
On the outer periphery of the piston, a notch that forms a gap with the inner periphery of the cylinder is formed from the one end side toward the other end side, and the notch is formed in the notch portion. The damper according to any one of claims 1 to 4, wherein the damper is provided to be positioned.