JPH08105482A - Air damper - Google Patents

Abstract

PURPOSE: To cope with the fluctuation of a load by changing a brake force and to perform suitable braking. CONSTITUTION: Through relative movement of a piston 12 within a cylinder 14, air in an air chamber flows through an orifice 48, and braking is effected on opening closing operation of the lid of the globe box of an automobile. When the piston 12 is moved from one end in the direction of the other end (an arrow mark C), when an O-ring 42 is located in a groove forming part 54 at one end part of the cylinder 14, air escapes through a groove 55, and a brake force is reduced to decrease braking. After the O-ring 42 is moved out from a groove forming part 54, braking is rendered effective based on the orifice 48 along with movement of the piston 12 to the other end of the cylinder 14. When the piston 12 is located at one end of the cylinder 14, in the case a load exerted in one way of the piston 12 by a lid 66 is low, braking is decreased at one end part of the cylinder 14 where a load exerted in one way of the piston 12 is low and coping with the fluctuation of a load is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylinder type air damper for braking by allowing a piston to relatively move in a cylinder to flow air in an air chamber in the cylinder through an orifice.

[0002]

2. Description of the Related Art As an air damper of this type, for example,
Some are used for automobile glove boxes.

That is, in the air damper, one end of the cylinder is the bottom and the other end is closed by the cap, and the piston rod extends through the cap to the outside of the cylinder.
The piston is provided with an O-ring, and the O-ring is fitted in a concave portion annularly provided on the outer circumference of the piston and is in contact with the inner circumference of the cylinder. The chamber is partitioned and formed (the first air chamber is formed on one end side of the cylinder, and the second air chamber is formed on the other end side of the cylinder.

The piston is provided with an orifice which connects the front and rear sides (the first air chamber and the second air chamber) in the moving direction.

Further, the recess allows the O-ring to move relative to the piston along the direction of movement of the piston, and when the piston changes its moving direction from one end to the other end of the cylinder from one direction to the other, it becomes the O-ring. When the O-ring is moved from the first position to the second position by the frictional force with the inner circumference of the cylinder, and conversely when the piston changes the moving direction from the opposite direction to the one direction, the O-ring is moved to the first position by the frictional force. Move from position 2 to position 1. A groove is formed at the bottom of the recess, and the O-ring is the second
When in the position, the first air chamber and the second air chamber communicate with each other through the groove, and when the O-ring is in the first position,
The groove is closed.

When the piston moves in one direction, air flow is performed at the orifice, and the braking force is exerted based on the flow resistance at the orifice. Conversely, when the piston moves in the opposite direction, air escapes through the groove, reducing braking.

When such an air damper is used in a glove box, the piston rod is connected to the lid of the glove box, the cylinder is connected to the storage side of the glove box, and the piston rod is pulled out from the cylinder when the lid is opened. The piston is adapted to move in one direction from one end of the cylinder to the other. As a result, when the lid is opened, the opening operation is slowed down so that no impact is generated. On the contrary, when closing the lid, the closing operation is prompt.

[0008]

By the way, when the lid of the glove box is opened from the vertical state to the horizontal state, the load applied to the piston in one direction is small at the initial stage of the opening operation of the lid, and the lid is opened. As it opens, the load exerted on the piston in one direction gradually increases (the load fluctuates).

If the braking force of the air damper is effective at the initial stage of the opening operation of the rod, it is possible that the lid remains in the vertical state and cannot be opened only by its own weight.

If the load exerted on the piston in one direction gradually increases as the lid opens, the braking force of the air damper becomes insufficient and the opening speed of the lid increases. At the open limit position, the lid bounces due to recoil, and a smooth opening operation cannot be obtained.

As described above, the air damper cannot cope with a change in load. The present invention has been made in view of the above facts, and an object thereof is to provide an air damper that changes a braking force to cope with a change in load and obtains suitable braking.

[0012]

In order to solve the above-mentioned problems, the air damper of the present invention according to claim 1 is provided with a seal member in contact with the inner circumference of the cylinder on the outer circumference of the piston to form an air chamber in the cylinder. Then, in the air damper in which the piston relatively moves in the cylinder between the one end and the other end, the air in the air chamber is caused to flow through the orifice, and the braking is performed, the cylinder has the one end opened and the other The cylinder is formed in a bottomed cylindrical shape having a bottom at the end, and the open end is closed by a cap. At one end of the cylinder, a long groove extending from the open end of the cylinder along both ends of the cylinder is formed. It is characterized in that it is provided with a groove forming portion provided in the inner periphery, and when the seal member is located in the groove forming portion, the groove communicates with both front and rear sides in the moving direction of the piston to allow air to escape and reduce braking. .

In the air damper of the present invention according to claim 2, a seal member, which is in contact with the inner circumference of the cylinder, is provided on the outer circumference of the piston to form an air chamber in the cylinder, and the piston is arranged between the one end and the other end in the cylinder. In the air damper that moves relatively in the air chamber to flow the air in the air chamber to perform braking, the orifice is provided in the piston, communicates both front and rear sides in the moving direction of the piston, regardless of the position of the piston. A groove forming portion having a first orifice that is always opened and a long groove that extends from one open end of the cylinder along both ends of the cylinder, except for the other end of the cylinder, is formed on the inner circumference of the cylinder. And the groove is a second orifice communicating with the front and rear sides in the moving direction of the piston when the seal member is located in the groove forming portion.

According to a third aspect of the present invention, in the air damper of the first aspect, the orifice is provided in the piston, communicates both front and rear sides in the moving direction of the piston, and is always opened regardless of the moving direction of the piston. As well as
Similarly, the piston is provided with an opening / closing hole that communicates both front and rear sides in the moving direction of the piston, and the sealing member is formed by an O-ring, and has a first position and a second position with respect to the piston along the moving direction of the piston. Between the seal member and the cylinder when the moving direction of the piston changes from one direction to the opposite direction. It moves from the first position to the second position based on the frictional force with the circumference, and when the moving direction of the piston changes from the opposite direction to the one direction, it moves from the second position to the first position based on the frictional force. , Is characterized.

According to the first aspect of the invention, the air damper in which the piston rod of the piston extends through the bottom of the cylinder to the outside of the cylinder and the open end of the cylinder is airtightly closed by a cap is specifically mentioned. To be

[0016]

According to the structure of the first aspect, the piston moves relatively in the cylinder, whereby the air in the air chamber flows through the orifice to perform braking.

When the piston moves from one end of the cylinder to the other end, if the seal member is in the groove forming portion of the one end of the cylinder, air escapes through the groove, the braking force is weakened, and braking is performed. Reduced. After the seal member exits the groove forming portion, the braking is effective as the piston moves to the other end of the cylinder.

For example, when the load applied to the piston in one direction is small when the piston is located at one end of the cylinder, braking is reduced at the one end of the cylinder where the load applied to the piston in one direction is small. It is possible to cope with load fluctuation.

As described above, the braking force can be changed to cope with the fluctuation of the load, and suitable braking of the piston can be obtained.

Further, the cylinder has a bottomed cylindrical shape with the other end as a bottom and one end opened, and the groove forming portion is formed on the open other end side of the cylinder, and the groove bottom of the groove forming portion is the cylinder. Since the diameter is larger than the inner circumference of the groove, the groove forming portion of the cylinder can be easily formed.

[0021] Claim 3 is a so-called one-way type air damper, and since the braking force is reduced by the movement of the piston in the opposite direction, the movement of the movable member accompanied by the movement of the piston in the opposite direction, This is effective when it is not necessary to brake the vehicle.

According to the second aspect of the invention, when the piston moves from one end to the other end of the cylinder and the seal member (O-ring) is in the groove forming portion, the first orifice, and Air flow is made by the second orifice, and the braking force is weakened and the braking is reduced by the amount of both orifices. When the seal member exits the groove forming portion and reaches the other end of the cylinder, there is no air flow in the second orifice, and air flow is made by the first orifice, so that braking is effective.

For example, when the load applied in one direction of the piston is large when the piston is at the other end of the cylinder, braking is performed at the other end of the cylinder where the load applied in one direction of the piston is large. Is effective and can cope with load fluctuations.

Also according to the second aspect of the invention, the braking force can be changed to cope with the fluctuation of the load, and suitable braking of the piston can be obtained.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of an air damper according to the present invention will be described below with reference to FIGS. 1 to 9 by applying it to a glove box of an automobile.

As shown in FIGS. 1 and 3, the air damper 1
At 0, the piston 12 moves inside the cylinder 14 along the axial direction of the cylinder 14 (left-right direction in FIG. 1).
4 can be relatively reciprocated between one end (the left end in FIG. 1) and the other end (the right end in FIG. 1). The cylinder 14 is composed of a bottomed cylindrical cylinder body 18 having one end open and a bottom 16 at the other end, and a cap 20 closing the open end. The cap 20 has a cylindrical shape with a bottom,
The engaging hole 22 provided on the peripheral surface of the cap 20 is elastically engaged with the engaging protrusion 24 provided on the outer periphery of the cylinder body 18 correspondingly, and is attached. An O-ring 26 is provided between the cap 20 and the cylinder body 18 to ensure airtightness of a first air chamber 44 described later. A split groove 28 is formed at the open end of the cap 20 to facilitate the engagement of the engagement protrusion 24 with the engagement hole 22.

As shown in FIGS. 4 and 5, the piston 12
Is coaxial with the cylinder 14 and has a bottomed cylindrical shape with one end side of the cylinder 14 open and the bottom 30 on the other end side.
One end of a piston rod 32 is connected to the bottom 30 of the piston 12. The piston rod 32 has a long plate shape,
The piston rod 32 is located coaxially with the cylinder 14, and the other end of the piston rod 32 extends through the through hole 34 in the bottom 16 of the cylinder 14 to the outside of the cylinder 14.

The outer circumference of the piston 12 has a shape in which large diameter portions 36 and 38 are provided at both ends in the axial direction, and an annular recess 40 is formed between the large diameter portions 36 and 38. An O-ring 42 formed of an elastic material such as rubber made of synthetic resin, which serves as a sealing member, is fitted in the recess 40, and the large diameter portions 36 and 38 are formed.
The O-ring 42 is in contact with the inner circumference of the cylinder 14 in a state where a gap is formed between the outer circumference of the cylinder 14 and the inner circumference of the cylinder 14, and inside the cylinder 14, both sides of the piston 12 in the axial direction (the moving direction of the piston 12). Air chambers 44 and 46 are formed on both sides). That is, the first air chamber 44 is formed on one end side of the cylinder 14, and the second air chamber 46 is formed on the other end side of the cylinder 14.

Further, on the bottom 30 of the piston 12, both axial sides of the piston 12 (first air chamber 44 and second air chamber 46) are provided.
An orifice (small hole) 48 that communicates with the () is provided.

On the other hand, in the recess 40, the O-ring 42
Is movable in the axial direction (width direction of the recess 40) with respect to the piston 12, and the moving range is restricted by contact with a large diameter portion (first large diameter portion) 36 on one end side of the cylinder 14. First
Between the position (the position shown in FIGS. 2 and 5) and the second position (the position shown in FIGS. 1 and 4) in which the contact is restricted by the large diameter portion (second large diameter portion) 38 on the other end side of the cylinder 14. It is said that Piston 12
However, if the movement direction is changed from the movement of the cylinder 14 from one end to the other end (indicated by an arrow C in the figure) to the opposite direction (direction from the other end of the cylinder 14 to one end), the O-ring is moved. Due to the frictional force between 42 and the inner circumference of the cylinder 14, regardless of the movement of the piston 12, it becomes substantially immovable with respect to the cylinder 14 along the movement direction of the piston 12, and moves relatively from the first position to the second position. , Is retained in the second position by continued movement of the piston 12 in the opposite direction. On the contrary, when the piston 12 changes its moving direction from the opposite direction to the one direction, the moving direction of the piston 12 with respect to the cylinder 14 does not depend on the movement of the piston 12 due to the frictional force between the O-ring 42 and the inner circumference of the cylinder 14. Along with the movement of the piston 12 relative to the first position relative to the second position, and the piston 12 is held in the first position by the continued movement in one direction.

A groove 52 is formed in the bottom of the recess 40 along the width direction of the recess 40 so as to cut out a part of the second large diameter portion 38 and communicate with the cutout 50. The groove 52 is
It extends to the middle of the recess 40 in the width direction and does not reach the first large diameter portion 36. When the O-ring 42 is in the second position, the O-ring 42 is located in a portion of the recess 40 where the groove 52 exists.
2, a groove is formed between the groove 52 and the second air chamber 46 through the notch 50, and the groove 52 is exposed on the first large diameter portion 36 side of the O-ring 42 on the other hand. First large diameter portion 36
Through the gap between the outer circumference of the cylinder and the inner circumference of the cylinder 14.
It communicates with the air chamber 44. When the O-ring 42 is in the first position, the O-ring 42 is located in the recessed portion 40 where there is no groove 52, and the other of the grooves 52 cannot be exposed to the first large-diameter portion 36 side of the O-ring 42, and thus the first air chamber. The groove 52 does not allow the 44 and the second air chamber 46 to communicate with each other. The groove 52 constitutes an opening / closing hole that is closed by movement of the piston 12 in one direction and opened by movement of the piston 12 in the opposite direction. In this embodiment, the groove 52 is formed at two places in the recess 40.

The opening / closing hole formed by the groove 52 is larger than the hole diameter of the orifice 48. Piston 12
Is moved in one direction, the air flow between the air chambers 44 and 46 is performed by the orifice 48, and the braking force acts on the basis of the flow resistance of the air passing through the orifice 48, and the braking is effective. Conversely, when the piston 12 moves in the opposite direction, the air flow across both air chambers 44, 46 is predominantly through the groove 52, which causes air to escape through the groove 52 and is controlled. Power is reduced and braking is reduced.

Further, as shown in FIGS. 2 and 5, a groove forming portion 54 is formed at one end of the cylinder 14. In the groove forming portion 54, a groove 55 is formed on the inner circumference of the cylinder 14, and the groove is recessed so that the bottom is larger than the inner diameter of the cylinder 14, and is elongated from one end of the cylinder 14 along the axial direction. As shown in FIG. 9, four cables are provided at equal angular intervals in the circumferential direction. When the O-ring 42 is located at the middle portion in the groove longitudinal direction of the groove forming portion, the groove 55 forms a gap with the O-ring 42, one of which is in communication with the first air chamber 44 and the other of which is the first air chamber 44. 2 is communicated with the air chamber 46, the groove 55,
It is made larger than the diameter of the orifice 48.

At one end of the cylinder 14, the outer circumference is
A mounting piece 56 is provided so as to project, and a mounting hole 58 is formed in the mounting piece 56. Further, a mounting hole 60 is formed at the extending tip of the piston rod 32.

In a glove box of an automobile using the air damper 10 thus constructed (in FIG. 8, two glove boxes 62 and 68 are provided above and below,
The upper glove box 62 will be described), FIG.
And, as shown in FIG. 7, a lid 64 as a movable member of the glove box 62 is rotatably supported on the storage portion 66 side of the glove box 62 by a rotating shaft 65 at the lower end thereof, and is in a vertical state (see FIG. 6 state), and open horizontally (state of FIG. 7). The mounting piece 56 is supported by the storage portion 66 side of the glove box 62 via the mounting hole 58 and is rotatable about the mounting hole 58, and the piston rod 32 is mounted on the glove box 58 via the mounting hole 60. It is supported by the lid 64 and is rotatable around the mounting hole 60.

When the lid 64 is closed and in the vertical state, the piston rod 32 is retracted into the cylinder 14 and the piston 12 is located at one end of the cylinder 14. As shown in FIG. 7, as the lid 64 opens from the vertical state (indicated by the alternate long and short dash line in FIG. 7) in the direction of the arrow D, the piston rod 32 is pulled out from the cylinder 14, and the piston 12 is moved once inside the cylinder 14. From one direction to the other end. In the horizontal position where the lid 64 is completely opened (indicated by a chain double-dashed line in FIG. 7), the piston 12 moves to the cylinder 1
Located at the other end of 4.

According to the above structure, the piston 12 moves relatively in the cylinder 14 to cause the air chamber 4 to move.
Air of 4, 46 flows through the orifice 48, and braking is performed.

When the piston 12 moves from one end of the cylinder 14 to the other end, when the O-ring 42 is in the groove forming portion 54 of the one end of the cylinder 14, air escapes through the groove 55 and the braking force is increased. Is weakened and braking is reduced. After the O-ring 42 exits the groove forming portion 54, as the piston 12 moves to the other end of the cylinder 14, the orifice 4
Braking is effective based on 8.

When the load exerted by the lid 66 in one direction of the piston 12 is small when the piston 12 is at one end of the cylinder 14, one end of the cylinder 14 in which the load exerted in one direction of the piston 12 is small. In the part, braking is reduced and load fluctuation can be dealt with. Piston 12
In the initial movement of the lid 66 when the load exerted on it is small, it is possible to effectively obtain the idling state in which the braking force is not exerted.

Regarding the groove forming portion 54, the axial length L of the groove forming portion 54 (see FIGS. 1 and 2), the number of the grooves 55, the shape and size of the grooves 55, etc. are subject to load fluctuations. It is set as appropriate in order to deal appropriately.

The bottom of the groove 55 may be larger than the inner circumference of the cylinder 14. Although the groove 55 is elongated in the above embodiment, the groove width of the groove 55 (dimension in the circumferential direction)
Is not limited to the narrow width as in the above embodiment, and is not particularly limited.

Further, according to the so-called one-way type air damper in which the braking is effective by the movement of the piston 12 in one direction and the braking is reduced by the movement of the piston 12 in the opposite direction, the opening operation is performed when the lid 64 is opened. When the lid 64 is closed slowly, the braking operation is effective when the closing operation is performed promptly without requiring the braking as much.

Further, the cylinder 14 has a bottomed cylindrical shape with the other end serving as the bottom 16 and one end opened, and the groove forming portion 54 is formed on the open one end side of the cylinder 14, and the groove forming portion 54 is formed.
Since the bottom of the groove 55 has a larger diameter than the inner circumference of the cylinder 14, the groove forming portion 54 of the cylinder 14 can be easily formed.

The O-ring 42 is brought into sliding contact with the inner circumference of the cylinder 14 as the piston 12 moves, and a frictional force acts between the O-ring 42 and the inner circumference of the cylinder 14. Groove 5
In No. 5, the bottom is recessed so as to be larger than the inner diameter of the cylinder 14. Therefore, even when the O-ring 42 is in sliding contact with the groove forming portion 54, the contact pressure against the O-ring 42 is not increased. Absent. Instead of forming the groove 55, it is conceivable to form a rib on the inner circumference of the cylinder, that is, a rib projecting to a smaller diameter side than the inner circumference of the cylinder. In this case, however, the rib bites into the O-ring to prevent resistance. Grows larger. Alternatively, instead of forming the groove 55, the taper surface on the inner circumference of the cylinder, that is, the inner circumference of the cylinder other than the one end of the cylinder, is gradually increased toward one end of the cylinder at one end of the cylinder. Although it is possible to form a tapered surface having a diameter, in this case,
The tapered surface causes rattling of the piston, causing the piston rod to wavy and become unstable.

Next, a second embodiment will be described with reference to FIGS. In the first embodiment, the groove forming portion 54
Is formed at one end of the cylinder 14, but in the air damper 100 of the present embodiment, the groove forming portion 102 does not stop at one end of the cylinder 14 and is a portion other than the other end of the cylinder body 106 of the cylinder 104. An orifice 4 formed by extending from one end of the cylinder 14 and similar to the first embodiment.
8 is the first orifice, and the groove 108 of the groove forming portion 102 is the second orifice.

According to this structure, when the piston 12 moves from one end of the cylinder 104 to the other end, when the O-ring 42 is in the groove forming portion 102, the orifice 48,
Then, air flow is made by the groove 108, and the braking force is weakened by the amount of the orifices 48, 108 being weakened. When the O-ring 42 exits the groove forming portion 102 and reaches the other end of the cylinder 14, there is no air flow in the groove 108, and air flow is made by the orifice 48, and braking is effective.

When the load exerted by the lid 64 in one direction of the piston 12 is large when the piston 12 is at the other end of the cylinder 104, the load exerted by the lid 104 in one direction of the cylinder 104 is large. At the other end, braking is effective and load fluctuations can be dealt with.

Regarding the groove forming portion 102, the axial length L of the groove forming portion 102, the number of the grooves 108, the shape of the grooves 108, etc. are appropriately set in order to appropriately cope with load fluctuations. The same as in the first embodiment.

The other structure, function and effect are similar to those of the first embodiment. In each of the above-mentioned embodiments, the air damper is applied to the glove box of the automobile for explanation, but the invention is not limited to this.
For example, the present invention can be applied to other things such as an opening / closing cover of an operation panel of a television or the like.

Further, in each of the above-mentioned embodiments, the lid as the movable member is connected to the piston side, but conversely, the lid may be connected to the cylinder side.

[0051]

As described above, according to the air damper of the present invention, the braking force can be changed to cope with the variation of the load, and a suitable braking can be obtained.

[Brief description of drawings]

1 shows a first embodiment of the air damper of the present invention, and FIG.
4 is a cross-sectional view seen from the direction of arrow A in FIG.

FIG. 2 is a view corresponding to FIG. 1, showing a state in which a piston is located at the other end of the cylinder.

FIG. 3 is an exploded perspective view showing an air damper of the first embodiment.

FIG. 4 shows a part of the air damper of the first embodiment, and shows a state in which the piston is located at one end of the cylinder, which is indicated by an arrow B in FIG.
It is an expanded sectional view seen from the direction.

FIG. 5 shows a part of the air damper of the first embodiment, and shows a state where the piston is located at the other end of the cylinder, as indicated by an arrow B in FIG.
It is an expanded sectional view seen from the direction.

FIG. 6 is a diagram showing the air damper of the first embodiment applied to a glove box of an automobile.

FIG. 7 is a view corresponding to FIG. 6, showing a state of the air damper when the lid of the glove box is opened.

FIG. 8 is a perspective view showing a glove box of an automobile.

FIG. 9 is a cross-sectional view showing a groove forming portion as viewed from the axial direction of the cylinder.

FIG. 10 is a diagram corresponding to FIG. 1 showing a second embodiment.

FIG. 11 is a diagram corresponding to FIG. 2 showing a second embodiment.

[Explanation of symbols]

 10 Air Damper 12 Piston 14 Cylinder 16 Bottom 20 Cap 32 Piston Rod 42 O-ring (Seal Member) 44 First Air Chamber (Air Chamber) 46 Second Air Chamber (Air Chamber) 48 Orifice 52 Groove (Opening / Closing Hole) 64 Lid (Movable) Member) 54 Groove forming part 55 Groove

Claims (3)

[Claims] 1. A seal member, which is in contact with the inner circumference of the cylinder, is provided on the outer circumference of the piston to form an air chamber in the cylinder, and the piston relatively moves in the cylinder between one end and the other end to form an orifice. In the air damper for causing the air in the air chamber to flow therethrough for braking, the cylinder is formed in a bottomed cylindrical shape with the one end opened and the other end bottomed, and the opened one end is closed by a cap. A groove forming portion is provided at one end portion of the cylinder, in which an elongated groove extending from an open end of the cylinder along both end directions of the cylinder is provided in the inner circumference of the cylinder. When the seal member is located in the groove forming portion, the groove is formed. Is an air damper that communicates with the front and back sides of the piston in the moving direction to release air and reduce braking. 2. A seal member, which is in contact with the inner circumference of the cylinder, is provided on the outer circumference of the piston to form an air chamber in the cylinder, and the piston relatively moves in the cylinder between one end and the other end to form an orifice. In the air damper that causes air in the air chamber to flow therethrough for braking, the orifice is a first orifice that is provided in the piston, connects the front and rear sides in the moving direction of the piston, and is always opened regardless of the position of the piston. In addition, except for the other end of the cylinder, a groove forming portion is provided in which a long groove extending from one open end of the cylinder along both end directions of the cylinder is recessed in the inner circumference of the cylinder. An air damper characterized by being a second orifice communicating with the front and rear sides in the moving direction of the piston when positioned in the groove forming portion. 3. The orifice is provided in the piston,
The piston is connected to the front and rear sides in the moving direction and is always open regardless of the moving direction of the piston. The piston is also provided with an opening / closing hole which communicates the front and rear sides in the moving direction of the piston. And is movable relative to the piston in the moving direction of the piston between a first position and a second position. The opening / closing hole is closed at the first position and the opening / closing hole is opened at the second position. When the piston is opened and the moving direction of the piston changes from one direction to the opposite direction, the piston moves from the first position to the second position based on the frictional force between the seal member and the inner circumference of the cylinder, and the moving direction of the piston is opposite. When changing from one direction to one direction, the second position changes to the first position based on the frictional force.
The air damper according to claim 1, wherein the air damper is moved to a position.