JP6961801B2 - Damper - Google Patents

Description

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

For example, automobile glove boxes may use dampers to prevent the lid from opening suddenly and to open it gently.

As such a damper, Patent Document 1 below describes a cylinder, a rod inserted into the cylinder, a piston attached to the base end side of the rod and provided with an air flow passage, and a buffer fixed to the tip end side of the rod. A damper with a member and a cap attached to the base end opening of the cylinder is described. A spring is interposed inside the cushioning member, and the cushioning member is urged so as to protrude from the tip opening of the cylinder. Further, an elongated cylindrical wall is formed inside the cylinder, a rod is inserted into the cylindrical wall, and an annular gap is formed between the inner circumference of the tubular wall and the outer circumference of the rod. There is. Further, a recess is formed with a predetermined length in the space around the cylinder where the piston is arranged (see Fig. 4).

Then, when the cushioning member is pushed and pulled into the tip opening of the cylinder and the pushing force on the cushioning member does not act, the cushioning member protrudes from the tip opening of the cylinder by the urging force of the spring. At this time, the cushioning member is braked by the frictional force between the piston and the inner circumference of the cylinder, the annular gap between the inner circumference of the tubular wall and the outer circumference of the rod, and the resistance when the air flows through the air flow passage of the piston. Will be done. Further, when the cushioning member is pushed from the state of protruding from the tip opening of the cylinder and the cushioning member moves to the return direction side opposite to the braking direction, the air in the cylinder becomes the inner circumference of the cylindrical wall. The braking force is released by flowing through the annular gap between the rod outer circumference, the air flow passage of the piston, and the recess provided between the piston and the inner circumference of the cylinder, and the braking force is released, and the cushioning member is released. It is housed in the tip opening of the cylinder.

European Patent Application Publication No. 1260159 (EP1260159A2)

In recent years, it has been desired to reduce the size of the damper because it is desired to reduce the installation space of the damper. Further, in the damper, when the piston moves in the return direction opposite to the braking direction, it is preferable that the piston returns smoothly with less resistance.

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

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 suppress the 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 separated from each other and applies a braking force when both members are close to each other or separated from each other, and the end portion forms an opening. It consists of a tubular cylinder, a rod that is movably inserted through the opening of the cylinder, and an elastic resin material that extends along the axial direction of the rod to a predetermined length and is mounted so as to surround the rod. It has a piston, and the rod has an engaging portion that engages with the piston when moving in a return direction opposite to the braking direction of the damper, and the piston has a braking direction of the damper. It is characterized in that a notch is provided from one end on the opposite side to the other end on the braking direction side of the damper.

According to the present invention, the piston is provided with a notch from one end on the side opposite to the braking direction of the damper toward the other end on the braking direction side of the damper. When moving in the opposite return direction, the closed notch is pushed open by pneumatic pressure, which can facilitate the escape of air between the cylinder and the piston, resulting in the piston returning the damper. It is possible to reduce the resistance when moving to, make it easier to return the piston, and suppress the increase in size of the cylinder and piston.

It is an exploded perspective view which shows one Embodiment of the damper which concerns on this invention. The rods constituting the damper are shown, (a) is a perspective view thereof, (b) is a plan view, and (c) is a side view. The pistons constituting the damper are shown, (a) is a perspective view thereof, and (b) is a perspective view when viewed from a direction different from (a). The pistons constituting the damper are shown, (a) is a plan view, (b) is a side view, (c) is a cross-sectional view taken along the line AA of (a), and (d) is (b). Is a cross-sectional view taken along the line BB, and (e) is a cross-sectional view taken along the line CC of (b). It is a perspective view which shows the state when the rod moves in the return direction opposite to the braking direction of a damper in the piston which constitutes the damper. The caps constituting the damper are shown, (a) is an assembled perspective view thereof, and (b) is an exploded perspective view. The usage state of the damper is shown, (a) is an explanatory view of a state in which the rod is stationary, and (b) is an explanatory view of a state in which the braking force of the damper is applied. The usage state of the damper is shown, and it is explanatory drawing of the state in which the braking force of the damper is released. It is an enlarged explanatory view of the main part of the damper. (A) is an enlarged cross-sectional view of a main part in a state where the rod is stationary, and (b) is an enlarged explanatory view of a main part for explaining the pressure contact state of the piston with respect to the inner circumference of the cylinder in (a). (A) is an enlarged cross-sectional view of a main part in a state where the rod is moved in the damper braking direction, and (b) is an enlarged explanatory view of a main part for explaining the pressure contact state of the piston with respect to the inner circumference of the cylinder in (a). (A) is an enlarged cross-sectional view of a main part in a state where the rod is moved in the return direction opposite to the braking direction of the damper, and (b) is a main part for explaining the pressure contact state of the piston with respect to the inner circumference of the cylinder in (a). It is an enlarged explanatory view. The state in which the piston has returned from the contracted state shown in FIG. 12 is shown, (a) is an enlarged cross-sectional view of the main part thereof, and (b) is the state of pressure contact of the piston with respect to the inner circumference of the cylinder in (a). It is an enlarged explanatory view of the main part. It is an enlarged explanatory view of the main part of the damper which made the braking direction of the damper opposite to the damper of the said embodiment.

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

The damper 10 shown in FIG. 1 is attached to a pair of members that are close to each other and separate from each other, and applies a braking force when the pair of members are close to each other or separate from each other. 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 or lid that is openable and closable in the opening of the accommodating portion. In the following embodiments, one member is a fixed body such as an instrument panel accommodating portion, and the other member is attached to an opening of the fixed body so as to be openable and closable, such as a glove box or a lid. Although it will be described as an opening / closing body, the pair of members is not particularly limited as long as they can be brought close to each other and separated 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 axial tip side of the rod 30. It is mainly composed of a piston 50 made of the elastic resin material and a cap 80 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 by a predetermined length, and one end side in the axial direction thereof opens to form an opening 22. ing. Further, the other end side of the wall portion 21 is closed by the end wall 23. An annular mounting portion 24 is provided on the outside of the end wall 23, and the cylinder 20 can be mounted to one member such as an instrument panel via the mounting portion 24. .. Further, circular fitting holes 25, 25 are formed on one end side of the wall portion 21 so as to face each other in the circumferential direction (see FIG. 1). The other end side of the wall portion 21 may be opened to mount a cap provided with an orifice, and the mounting portion may be provided at a predetermined position in the axial direction on the outer periphery of the wall portion 21. The outer diameter of the cylinder 20 is preferably 12 mm or less, more preferably 8 mm or less.

As shown in FIGS. 6A and 6B, the cap 80 in this embodiment has a pair of half-split bodies 81 and 81 having a half-cylindrical shape. These are engaged with each other via a locking piece 88 and a locked portion 90 that locks to the locking piece 88, so that they are integrated. Each half-split 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 middle of the axial direction. Then, the cap 80 is inserted into the opening 22 of the cylinder 20 from the tip end side thereof, each flange portion 83 is locked to the base end surface of the cylinder 20, and each fitting protrusion 84 is fitted to the cylinder 20. By fitting the holes 25 and 25, the cylinder 20 is mounted on the base end side (see FIGS. 7 and 8).

The rod 30 is movably inserted into the cylinder 20 from the tip end side thereof through the opening 22 of the cylinder 20, and is connected to the cylindrical shaft portion 31 and the tip end side thereof. It has a piston mounting portion 32 on which the piston 50 is mounted. An annular mounting portion 33 is provided on the base end side of the shaft portion 31, and the rod 30 can be mounted on the other member such as a glove box via the mounting portion 33. There is.

With reference to FIGS. 2 (a) to 2 (c), the piston mounting portion 32 includes a first engaging portion 34 which is provided at the tip of the rod 30 in the axial direction and has a substantially disk shape, and the first engaging portion 34 thereof. It has a stopper portion 35 provided at a predetermined interval on the rod base end side with respect to the first engaging portion 34.

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

Further, the stopper portion 35 has a substantially circular protrusion shape as a whole, and the cut portions 35a, 35a formed by cutting the wall portion at positions on both sides in the circumferential direction on the side of the first engaging portion 34. Are formed respectively. Each cut portion 35a is provided with a flat surface continuous with the flat surface 40 provided on the second pillar portion 39, which will be described later (see FIG. 2A). The outer diameter of the first engaging portion 34 and the stopper portion 35 is formed to be 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 piston 50. It is formed longer than the axial length, and the piston 50 is vertically telescopically mounted between the first engaging portion 34 and the stopper portion 35.

Further, the piston mounting portion 32 is connected to the substantially cylindrical first pillar portion 36 extending from the inner surface side of the first engaging portion 34 toward the rod base end side and the tip of the first pillar portion 36 in the extending direction. A second engagement that engages 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) while forming a substantially circular protrusion. A substantially cylindrical second pillar portion 39 extending from the base end side of the portion 37 and the second engaging portion 37 to the rod base end side via the recess 38 and connected to the stopper portion 35. And have.

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

Further, as shown in FIGS. 9, 12 (a) and 13 (a), the second engaging portion 37 is arranged on the return direction side of the damper with respect to the pressure contact portion 53 described later of the piston 50. There is. Further, the second engaging portion 37 and the second pillar portion 39 have a larger diameter than the first pillar portion 36 and a smaller diameter than the first engaging portion 34 and the stopper portion 35, and the first pillar 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, the second engaging portion 37 of the piston 50 will be described later, as shown in FIGS. 12 (a) and 13 (a). It is designed to engage with the engaged portion 61. That is, the "engaging portion" of the rod in the present invention means the second engaging 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 a state of contracting in the axial direction and being in pressure contact with the inner circumference of the cylinder elastically returns to the extended state. However, as shown in FIG. 13, when the piston 50 is extended for the longest time, the stopper portion 35 comes into contact with 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. 2A, there are two outer circumferences of the first engaging portion 34, the stopper portion 35, the first pillar portion 36, and the second pillar portion 39 in the circumferential direction. The flat surfaces 40 and 40, which are cut in a plane 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 circumference of the cylinder 20 and the inner circumference of the piston 50.

Further, as shown in FIG. 2A, the ridge 41 abutting on the inner circumference of the piston 50 extends axially from the second engaging portion 37 side of the rod 30 toward the proximal end side, and A plurality of them are formed side by side at predetermined intervals in the circumferential direction. Specifically, in this embodiment, as shown in FIG. 2C, protrusions extending along the axial direction of the rod 30 on both sides of the outer periphery of the second pillar portion 39 in the circumferential direction of the flat surface 40. Articles 41 and 41 are projected from the tip portion of the rod 30 closer to the second engaging portion 37 side to the front portion of the stopper portion 35 (in this embodiment, the articles are projected at a total of four locations). 41 is provided). The ridge 41 forms a gap between the inner circumference of the piston 50 and the outer circumference of the second pillar portion 39.

Further, as shown in FIGS. 2 (a) and 2 (b), the groove portion 43 has a predetermined depth from one location on the inner surface of the first engaging portion 34 in the circumferential direction along the axial direction of the first pillar portion 36. Is formed. As shown in FIG. 2B, the groove portion 43 is provided between the flat surfaces 40 and 40 provided on the first engaging portion 34 so as to be in the middle thereof. As shown in FIG. 11A, the groove portion 43 is one of the inner surface of the first engaging portion 34 and the piston 50 even when one end surface of the piston 50 is in contact with the inner surface of the first engaging portion 34. A gap can be secured between the end face and the outer circumference of the first pillar portion 36 and the inner circumference of the engaged portion 61 of the piston 50 (see FIG. 4C). It has become.

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

As described above, the rod 30 having the above structure is inserted into the cylinder 20 from the first engaging portion 34 side of the tip and arranged so as to be movable in the cylinder 20. As shown in 7 and 8, the first chamber R1 of the rod 30 located on the return direction side of the damper and the braking direction side of the damper of the rod 30 with the first engaging portion 34 of the rod 30 as a boundary. The second chamber R2 located in is formed. In this embodiment, the first chamber R1 is formed on the end wall 23 side of the cylinder 20, and the second chamber R2 is formed on the opening 22 side of the cylinder 20. Further, the rod 30 described above includes the shaft portion 31, the mounting portion 33, the first engaging portion 34, the stopper portion 35, the second engaging portion 37, the first pillar portion 36, and the second pillar portion 39. , A plurality of ridges 41 and the like are all integrally formed.

Next, with reference to FIGS. 3 to 5, the rod 30 extends by a predetermined length along the axial direction, and is mounted on the base end side of the first engaging portion 34 of the rod 30 so as to surround 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, and 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 damping direction of the damper when the rod 30 moves in the braking direction of the damper, and follows the braking direction of the damper 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 at a predetermined length so as to form a substantially cylindrical shape and whose outer circumference has a circumferential shape. The outer circumference of one end 52 (the end located on the first engaging portion 34 side when the piston 50 is mounted on the rod 30) of the main body 51 on the side opposite to the braking direction of the damper is the main body 51. It has a tapered shape that gradually reduces in diameter toward one end surface in the axial direction.

Further, on the outer circumference of the other end of the main body 51 on the braking direction side of the damper (the end located on the stopper portion 35 side when the piston 50 is mounted on the rod 30), the inner circumference of the cylinder 20 is always present. A pressure welding portion 53 is provided for applying a braking force to the piston 50 when the rod 30 is pressure-welded and the rod 30 moves (both in the moving direction of the damper and in the returning direction of the damper).

In the following description, one end or one end of the piston on the side opposite 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 of the damper on the braking direction side is used. , Simply referred to as "the other end" or "the other end".

Further, as shown in FIGS. 4 (c) and 4 (d), the outer circumference 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 circumference 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 pressure contact portion 53.

Further, a notch 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 (main body 51 and pressure contact portion 53) to facilitate expansion and contraction of the piston 50, and a damper control by the piston 50. It is intended to adjust the power. As shown in FIG. 4 (e), the notch portion 54 has a shape in which a part of the circumferential shape of the outer circumference of the main body 51 is cut in one plane when the piston 50 is viewed from the axial direction. The main body 51 is formed so as to be parallel to each other at two locations in the circumferential direction. 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, in a state where the braking force of the damper is not acting, between the outer peripheral portion from the pressure contact portion 53 of the main body 51 to one end side and the inner circumference of the cylinder 20. A gap is formed. Further, since the notch portion 54 is formed in the pressure contact portion 53, the notch portion 54 of the pressure contact portion 53 can be formed at any time when the rod 30 or the piston 50 is stationary, when the damper is braked, or when the damper is released from braking. A gap is formed between the inner circumference of the cylinder 20 and the inner circumference of the cylinder 20 without being in close contact with the inner circumference of the cylinder 20.

The notch 54 in this embodiment is formed from the other end side 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 to the other end of the main body 51. However, the notch may be formed from one end of the main body 51 to the middle in the axial direction, or may be provided only on the pressure contact portion 53 on the other end side of the main body 51 without being formed on the outer periphery 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. , Has a pair of annular protrusions 56, 56 in an annular shape. These pair of annular convex portions 56, 56 are arranged on the outer periphery of the other end of the main body 51, respectively, between the notches 54, 54 provided at two locations in the circumferential direction of the pressure contact portion 53. (See FIG. 4 (e)). Specifically, each annular convex portion 56 is arranged on the outer periphery of the other end of the main body 51, and has a piston with respect to the first convex portion 57 extending along the circumferential direction of the main body 51 and the first convex portion 57. The second convex portion 58 extending along the circumferential direction of the main body 51, and both ends of the first convex portion 57 and the second convex portion 58 in the circumferential direction are arranged in parallel on one end side of the 50 at a predetermined interval. Consists of connecting protrusions 59 and 59 that connect the two to each other. Further, inside the convex portions 57, 58, 59, a concave groove 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 convex portions 57, 58, 59 are formed to be larger than the inner diameter of the cylinder 20, and the convex portions 57, 58, 59 are constantly pressed against the inner circumference of the cylinder 20. ing.

Further, as shown in FIGS. 4 (c) and 4 (d), an engaged portion 61 is provided on the inner circumference on one end side of the main body 51 so as to project in an annular shape along the circumferential direction. 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 ( See FIG. 12 (a)). At this time, as shown in FIG. 12B, a gap is formed between the first engaging portion 34 of the rod 30 and one end of the piston 50.

Further, as shown in FIGS. 3 (b), 4 (c), and 4 (d), one end of the main body 51 is located on the inner circumference of the main body 51 at a position corresponding to the pair of notched portions 54, 54. The air flow grooves 62 and 62 having a concave groove shape are formed so as to extend along the axial direction from the to the other end side. As shown in FIG. 9, in the air flow groove 62, the second engaging 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 to the second rod 30. It extends beyond the engaging portion 37 and the recess 38 to reach one end of the second pillar portion 39. Then, the air flow groove 62 forms a gap between the first pillar portion 36 of the rod 30, the second engaging portion 37, and the outer periphery of the second pillar portion 39 on one end side, and forms a gap between the rod 30 and the piston. It is a part that allows air to flow between the 50 and the 50. The air flow groove may be formed between the outer circumference of the rod 30 and the inner circumference of the piston 50, and may be formed on the outer circumference side of the rod, for example.

Further, as shown in FIGS. 3 and 4A, one notch 54 provided on the outer periphery of the main body 51 extends from one end to the other end of the piston 50 over the entire axial direction of the piston 50. A notch 55 is formed. As shown in FIGS. 4 (d) and 4 (e), the notch 55 communicates with one of the pair of air flow grooves 62 and 62 formed on the inner circumference of the piston 50. There is. When the piston 50 moves in the braking direction of the damper, the notch 55 is closed because the inside of the air flow 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 by the air flowing in from the air flow groove 62 to open (see FIGS. 5 and 8).

Further, since the main body 51 can be separated into two along the axial direction by the notch 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. The notch 55 may not be formed in the entire axial direction from one end to the other end of the main body 51, but may be formed in a length extending from one end to the other end side of the main body 51 in the middle of the axial direction. ..

Then, as shown in FIG. 9, in the state where the rod 30 and the piston 50 do not move in the braking direction and the return direction of the damper and are stationary, that is, in normal times when the piston 50 does not expand and contract, the first rod 30 is used. A gap is formed between the engaging portion 34 and one end of the piston 50, and a cut portion 35a 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. A gap is formed by.

In the damper 10 having the above configuration, when the damper is braked, the first engaging portion 34 of the rod 30 comes into contact with the one end portion 52 of the piston 50 and is constantly pressed against the inner circumference of the cylinder 20. An axial compressive force acts on the piston 50 between the annular protrusions 56 and 56. That is, as shown in FIG. 10A, when no braking force is applied to the damper, in FIG. 10B, the pair of annular convex portions 56, 56 of the piston 50 are formed on the inner circumference of the cylinder 20. Although it is pressure-welded, when the rod 30 moves in the braking direction of the damper from this state, the first engaging portion 34 comes into contact with the one end portion 52 of the piston 50 as shown in FIG. 11A, and the cylinder 20 When an axial compressive force acts on the piston 50 with the pressure contact portion 53 pressed against the inner circumference of the piston 50, the diameter of the piston 50 is expanded and the amount of pressure contact with respect to the inner circumference of the cylinder is increased. As a result, as shown in FIG. 11B, the portion S (the portion represented by the pointillistic hatching) of the piston 50 that is in pressure contact with the inner circumference of the cylinder 20 is increased, and the friction of the piston 50 with respect to the inner circumference of the cylinder 20 is increased. The force can be increased, and the braking force of the damper can be increased.

Further, the damper 10 in this embodiment serves as a passage for passing air through the piston 50 in the cylinder 20. (1) The flat surface 40 of the first engaging portion 34 of the rod 30 and the inner circumference of the cylinder 20. (2) The gap between the first engaging portion 34 of the rod 30 and one end of the piston 50, (3) the gap between the groove portion 43 of the rod 30 and the inner circumference of the piston 50, (4) the outer circumference of the rod 30 and the piston. The gap between the 50 air flow groove 62, (5) the gap between the recess 38 of the rod 30 and the inner circumference of the piston 50, and (6) the gap between the second pillar 39 of the rod 30 and the inner circumference of the piston 50 due to the ridge 41. , (7) A gap 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 gap between the flat surface 40 of the stopper portion 35 of the rod 30 and the inner circumference of the cylinder 20 are provided. There is.

Then, as shown in FIG. 9, when the rod 30 is stationary and the braking force of the damper is not applied, the gaps (1) to (8) above are secured. Further, as shown in FIG. 11, when the rod 30 moves in the braking direction of the damper, the first engaging portion 34 of the rod 30 comes into contact with one end of the piston 50, so that the gap (2) is eliminated. However, the gaps (1) and (3) to (8) above 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 one end of the piston 50 again. A gap is secured.

Further, in the damper 10, when the state in which the damper is braked is switched to the state in which the braking force of the damper is released, that is, an axial compressive force acts on the piston 50 as shown in FIG. When the rod 30 moves in the return direction of the damper from the state where the piston 50 has expanded in diameter and the frictional force with respect to the inner circumference of the cylinder 20 has increased, the following operation is performed to bring the piston 50 into a predetermined position. It has a structure that is easy to return. That is, when the rod 30 moves in the return direction of the damper from the state shown in FIG. 11, as shown in FIG. 12, the second engaging portion 37 of the rod 30 engages with the engaged portion 61 of the piston 50. An axial tensile force is applied to the piston 50 to extend one end side of the piston 50 to the other end side whose movement is restricted by the pressure contact portion 53, thereby reducing the diameter of the piston 50 to its original shape. Is possible (see FIG. 13). As a result, the frictional force of the piston 50 with respect to the inner circumference of the cylinder 20 can be reduced, making it easier to return the piston 50.

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

That is, in the 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 the arrow F1 in FIG. Then, the first engaging portion 34 comes into contact with one end portion 52 of the piston 50, and an axial compressive force acts on the piston 50 between the first engaging portion 34 and the pressure contact portion 53, so that the piston 50 expands in diameter with respect 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 circumference 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 can be increased. It is possible to obtain a damper 10 having excellent load response characteristics in which the braking force fluctuates according to the above.

On the other hand, from the state where the rod 30 moves in the braking direction of the damper, the piston 50 is compressed and the amount of pressure contact with the inner circumference of the cylinder is increased (see FIG. 11), the opening / closing body or the like is attached to the member such as the instrument panel. When the member is closed and the rod 30 moves in the return direction of the damper as shown by the arrow F2 in FIG. 8, the second engaging portion 37 of the rod 30 engages with the engaged portion 61 of the piston 50 ( (See FIG. 12A), the piston 50 is pushed toward the return direction of the damper. At this time, since the pressure contact portion 53 of the piston 50 is in a state of being pressure contacted with the inner circumference 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. An axial tensile force acts on the piston 50, and while the piston 50 made of an elastic resin material in a reduced diameter state is stretched in the axial direction, the first engaging portion 34 of the rod 30 is moved. Separate from one end side of the piston 50.

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 circumference of the cylinder 20 in (1). (2) The flow mainly flows from the gap between the first engaging portion 34 of the rod 30 and one end of the piston 50 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 closed notch 55 is pushed by air pressure and pushed from the inner edge side of the notch 55 to gradually open (in this case, one end side of the piston 50 is opened). The opening amount is relatively wide and the opening amount gradually decreases toward the other end side), and the air between the outer circumference of the rod 30 and the inner circumference of the piston 50 can be discharged from the notch 55 to the other end side of the piston 50. can.

The discharged air is the gap between the cut portion 35a of the stopper portion 35 of the rod 30 and the other end of the piston 50, and the flat surface 40 of the stopper portion 35 of the rod 30 and the inner circumference of the cylinder 20. The rod 30 is discharged to the outside of the piston mounting portion 32 through the gap between the rod 30 and the rod 30. Further, a part of the air includes the gap between the groove 43 of the rod 30 and the inner circumference of the piston 50, the gap between the outer circumference of the rod 30 and the air flow groove 62 of the piston 50, and the above (5). ) The other end side of the piston 50 through the gap between the recess 38 of the rod 30 and the inner circumference of the piston 50, and further through the gap between the second pillar 39 of the rod 30 and the inner circumference of the piston 50 due to the ridge 41 described above. Is discharged from.

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

As described above, in the damper 10, the main body 51 of the piston 50 is provided with a notch 55 from one end on the side opposite to the braking direction of the damper toward the other end on the braking direction side of the damper. 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 to secure the air flow passage, so that the first engaging portion of the rod 30 can be secured. The axial gap between the 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 engaging portion 34 of the rod 30 can be quickly brought into contact with the other end of the piston 50 to exert the braking force. The free running distance of the piston 50 during damper braking can be reduced (the responsiveness of the piston 50 during damper braking can be increased, and the play until the damper braking starts can be reduced).

Further, as described above, since the piston 50 can be easily returned to the predetermined position, it is possible to suppress the increase in size of the cylinder 20 and the piston 50, and it is possible to suppress the increase in size of the damper 10. When the rod 30 moves in the braking direction of the damper and the piston 50 also moves in the braking direction of the damper, the notch 55 closes, so that the pressure contact force of the outer circumference of the piston 50 with respect to the inner circumference 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. 4D, an air flow groove 62 communicating with the notch 55 is formed between the outer circumference of the rod 30 and the inner circumference of the piston 50. Therefore, when the piston 50 moves in the piston return direction and air enters the air flow groove 62, the closed notch 55 is pushed and opened as shown in FIGS. 5 and 8, so that the rod 30 and the piston are opened. The air between 50 and 50 can be easily discharged. That is, by providing the air flow groove 62, the notch 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 braking direction of the damper, the pressure inside the air flow groove 62 is reduced, so that the notch 55 can be closed smoothly, so that the piston 50 is pressed against the inner circumference of the cylinder. 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 FIGS. 3 and 4A, the notch 55 provided in the piston 50 extends from one end to the other end of the piston 50 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 more easily opened by the air that has entered the air flow groove 62, and the piston 50 is predetermined. It can be easily returned 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 circumference of the rod 30 (here, the piston mounting portion 32 of the rod 30).

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

Further, in this embodiment, as shown in FIGS. 3 and 4 (a) and 4 (d), a notch 54 forming a gap between the outer circumference of the piston 50 and the inner circumference of the cylinder 20 is formed. Is formed from one end side to the other end side, and the notch 55 is provided so as to be located in the notch 54. According to this, by providing the notch 55 in the notch 54 provided on the outer periphery of the piston 50, the sealing property (adhesion to the inner circumference of the cylinder 20) of the portion of the piston 50 other than the notch 54 can be improved. The notch 55 can be provided without damaging it, and the braking force of the damper can be less affected.

In this embodiment, when the first engaging 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 engaging portion 34 is applied. Is configured to release the braking force by the damper when the cylinder 20 moves closer to the end wall 23 of the cylinder 20, but conversely, the first engaging portion of the rod is the cylinder. When moving in the direction close to the end wall (including the cap attached to the end of the cylinder), the braking force by the damper is applied, and when moving in the direction away from the cylinder, the braking force is released. It may be configured 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, but the shape of the rod and the mounting direction of the piston of the damper 10A are different from those of the above embodiment. ing. The rod 30 has a shape in which the first pillar portion 36 extends longer than the second pillar portion 39. Further, the piston 50 is attached to the piston mounting portion 32 of the rod 30 with one end portion 52 directed toward the stopper portion 35 of the rod 30 and the pressure contact portion 53 of the piston 50 directed toward the first engaging portion 34 of the rod 30. The 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. Then, when the first engaging portion 34 of the rod 30 moves in a direction close to the end wall (left side in the drawing) of the cylinder 20 (not shown), that is, when it moves in the direction shown by the arrow F1 in FIG. The stopper portion 35 of the rod 30 abuts on one end portion 52 of the piston 50, and an axial compressive force acts between the stopper portion 35 and the pressure contact portion 53, so that a braking force due to the damper is applied. On the other hand, when the first engaging portion 34 of the rod 30 moves in a direction away from the end wall (not shown) of the cylinder 20, that is, when it moves in the direction shown by the arrow F2 in FIG. 2 The engaging portion 37 engages with the engaged portion 61 of the piston 50 to exert an axial tensile force on the piston 50, so that the braking force of the damper is released.

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

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

Claims (5)

A damper that is attached between a pair of members that are close to each other and applies braking force when both members are close to or separate from each other.
A cylindrical cylinder with an opening at the end,
A rod that is movably inserted through the opening of the cylinder and
It has a piston made of an elastic resin material that extends along the axial direction of the rod to 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 braking direction of the damper.
A damper characterized in that the piston is provided with a notch from one end on the side opposite to the braking direction of the damper toward the other end on the braking direction side of the damper. The damper according to claim 1, wherein an air flow groove communicating with the notch is formed between the outer circumference of the rod and the inner circumference of the piston. The damper according to claim 1 or 2, wherein the notch is provided over the entire axial direction from one end of the piston to the other end. The damper according to any one of claims 1 to 3, wherein the outer circumference of the piston has a tapered shape in which the diameter increases from the one end side of the piston toward the other end side. On the outer circumference of the piston, a notch forming a gap with the inner circumference of the cylinder is formed from one end side to the other end side, and the notch is formed in the notch. The damper according to any one of claims 1 to 4, which is provided so as to be located.

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