JPH11141592A - Rotary damper - Google Patents

Abstract

(57) [Problem] To reliably prevent liquid from leaking from a gap between an input / output shaft and a damper housing without using a special decompression structure or a high-pressure seal member. SOLUTION: A pressure receiving member 1 provided with vanes 15a and 15b.
2 is accommodated in the pressure chambers 20 and 21 in the damper housing 3, and the pressure receiving body 12 is fitted and fixed to the input / output shaft 4. The damper housing 3 includes a housing body 9 having pressure chambers 20 and 21 and a reservoir 25, and bearing grooves 30A and 3A.
Cover 1 provided with an outer cover 0B and seal grooves 31A and 31B
0A and 10B. Plates 36 to 39, 4 are provided between the housing body 9 and the side covers 10A, 10B.
0, and a slit 5 for connecting the bearing groove 30A and the seal groove 31A to the reservoir 25 in the plates 36 to 39.
4 and communication holes 55 to 57 are formed. Low pressure reservoir 25
Is supplied to the bearing 32 and the seal member 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary damper used as a shock absorber for a suspension link of an automobile and other rotating devices.

[0002]

2. Description of the Related Art As this kind of rotary damper, for example, one disclosed in Japanese Patent Application Laid-Open No. Hei 7-158680 has been proposed.

In this rotary damper, a substantially fan-shaped pressure chamber is formed in a damper housing, and an input / output shaft is rotatably supported at the center of the fan-shaped pressure chamber, and protrudes from the input / output shaft. The pressure-receiving vane is slidably housed in the pressure chamber, and the inside of the pressure chamber is divided into a plurality of liquid chambers by the vane. The liquid chamber on the side contracting and the liquid chamber on the expanding side in accordance with the operation of the pressure receiving member are connected to each other by a communication path,
A pair of damping valves are interposed in the communication passage. One of the pair of damping valves is set so as to operate in accordance with the flow direction of the liquid in the communication path, so that the damping force is generated even when the input / output shaft rotates in any direction. Has become.

In the case of the rotary damper, both ends of the input / output shaft are supported by a damper housing via bearings, respectively, and a gap between the damper housing and the input / output shaft is provided at an axially outer portion of each bearing. A sealing member for sealing is provided. In addition, a reservoir having a free piston structure is disposed at an intermediate position between the two damping valves in the communication passage, and a change in the volume of the liquid due to a temperature change is compensated by the reservoir.

[0005]

In the conventional rotary damper, the liquid leaking from the pressure chamber along the outer peripheral surface of the input / output shaft is used for lubrication of the bearing and the seal member. . However, since the inside of the pressure chamber is pressurized to a high pressure in accordance with the operation of the vane, there is a possibility that the high pressure acts on the seal member when the damper is operated, and it is ensured that the liquid leaks from the seal member. In order to prevent this, it is necessary to adopt a structure for reducing the pressure of the leaked liquid or to use a high-pressure seal member. Therefore, in any case, the production cost rises, and when a high-pressure sealing member is employed, the contact surface pressure with respect to the input / output shaft is increased, so that the durability may be further reduced.

Accordingly, the present invention provides a rotary damper which can reliably prevent liquid from leaking out of the damper housing without using a special decompression structure or a high-pressure sealing member, thereby reducing manufacturing costs. It is intended to provide.

[0007]

As means for solving the above-mentioned problems, the invention according to the first aspect of the present invention is arranged such that an input / output shaft is rotatably supported by a damper housing having a pressure chamber via a bearing. At the same time, a seal member that seals between the damper housing and the input / output shaft is disposed axially outside the bearing, and a pressure receiving member supported by the input / output shaft is slidably housed in the pressure chamber. The interior of this pressure chamber is separated into a plurality of liquid chambers by a pressure receiving body,
Further, a liquid chamber that contracts in accordance with the operation of the pressure receiving body and a liquid chamber that expands are connected by a communication path, and a damping valve is interposed in the communication path. In a rotary damper to which a reservoir for compensating for a change is connected, a low-pressure introduction path is provided for communicating the storage space for housing the bearing and the seal member in the damper housing with the reservoir. The reservoir is connected to the low pressure side of the damping valve, and the pressure inside the reservoir is maintained at a stable low pressure. The low-pressure liquid in the reservoir is always supplied to the bearing and the seal member via the low-pressure introduction path.

[0010] According to a second aspect of the present invention, in the first aspect of the present invention, the accommodating space includes a first accommodating space disposed at one end of the input / output shaft and an other end of the input / output shaft. And a second accommodation space arranged in the
The low-pressure introduction passage is formed along the axial direction on the input / output shaft or the pressure receiving body, the first introduction passage connecting a reservoir to the first accommodation space, and the first accommodation space is connected to the second accommodation space. And a second introduction path connecting the housing spaces. The first housing space and the second housing space on both sides of the input / output shaft communicate with each other at the shortest distance by the second introduction path. For this reason, formation of the second introduction path becomes easy.

According to a third aspect of the present invention, in the second aspect, the input / output shaft and the pressure receiving body are formed separately, and the input / output shaft and the pressure receiving body are fitted and fixed. The second introduction path is formed on the fitting surface on the pressure receiving body side. The second introduction path can be easily formed simultaneously with the molding of the pressure receiving body.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the damper housing includes a housing main body in which the pressure chamber and the reservoir are formed, and the housing space is formed. And a side cover, and a thin plate is sandwiched and fixed between the housing body and the side cover, and the notch forming the low-pressure introduction path is formed in the thin plate. A notch can be formed in the thin plate by press molding or the like, and the plate can be easily sandwiched and fixed between the housing body and the side cover, so that the low-pressure introduction path can be easily formed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described with reference to FIGS.
A description will be given based on FIG.

In the drawings, reference numeral 1 denotes a rotary damper according to the present invention. As shown in FIG. 2, the rotary damper 1 is used for a rotating shaft portion of an automobile suspension link 2 or the like. When the part rotates, a damping force is generated with the flow of the liquid inside.
In the case of the one shown in FIG. 2, the damper housing 3 of the rotary damper 1 is integrally connected to the base of the suspension link 2, and the input / output shaft 4 of the damper 1
And is rotatably held by the vehicle body 6 via a shaft, and is spline-fitted to the base of the torque arm 7. And
The tip end of the torque arm 7 is connected to the vehicle body 6 via another bracket 8 separated from the bracket 5, and the rotation of the input / output shaft 4 is separated from the center of the shaft 4 by a predetermined distance. The restriction is made on the vehicle body 6 side. Therefore, the suspension link 2
When the front end side (wheel side) swings with respect to the vehicle body 6,
The damper housing 3 rotates relatively to the input / output shaft 4 and generates a damping force with this rotation.

As shown in FIGS. 1 and 4, the damper housing 3 has a thick cylindrical housing body 9 and a pair of side covers 1 for closing both sides of the housing body 9.
The input / output shaft 4 is inserted into the housing main body 9 and rotated by the side covers 10A and 10B on both sides of the housing main body 9 and the cylindrical case 11 for accommodating the housing main body 9 and the side covers 10A and 10B. It is freely supported.

The input / output shaft 4 is formed in a cylindrical shape, and a pressure receiving body 12 is press-fitted or fixed to an outer peripheral surface of a substantially central portion thereof, and a spline 13 for coupling with the torque arm 7 is provided on an outer peripheral surface at one end. Are formed. The pressure receiving body 12 has a boss 14
And a pair of vanes 15a, 15b extending in opposite directions from the outer peripheral surface of the boss portion 14. The boss portion 14 and the vanes 15a, 15b are integrally formed by powder metallurgy. A groove 16 is formed on an inner peripheral surface of the boss portion 14 fitted to the input / output shaft 4 along an axial direction constituting a second introduction path described later.

The housing body 9 has a pair of fan-shaped grooves 17a, 17b formed in the inner peripheral surface thereof along the axial direction symmetrically with respect to the center axis, and a pair of adjacent arcs of the grooves 17a, 17b. The boss 14 of the pressure receiving body 12 is slidably fitted to the walls 18a and 18b. This arc wall 18
A seal member 19 is fitted and held in the shaft portions a and 18b along the axial direction.
a, 18b and the boss portion 14 are sealed. Each of the grooves 17a and 17b is provided in the side cover 10 on both sides.
A, 10B and the fan-shaped pressure chamber 2 between the boss portion 14 respectively.
The pressure chambers 0 and 21 are formed so that the vanes 15a and 15b of the pressure receiving body 12 are slidably accommodated in the pressure chambers 20 and 21, respectively. These vanes 15a, 15b
As shown in FIG. 3, each of the pressure chambers 20 and 21 is divided into two liquid chambers 22a and 22b and 23a and 23b, and between the adjacent liquid chambers as the input / output shaft 4 rotates. A pressure difference is created. In the following, for convenience of description, the pressure chamber located on the left side in FIG. 3 is referred to as a left pressure chamber 20, the pressure chamber located on the right side is referred to as a right pressure chamber 21, and a pressure chamber below the left pressure chamber 20. The liquid chamber is the left first chamber 22
a, the upper liquid chamber is referred to as a second left chamber 22b, the upper liquid chamber above the right pressure chamber 21 is referred to as a first right chamber 23a, and the lower liquid chamber is referred to as a second right chamber 23b.

The housing body 9 has a fan-shaped groove 24 formed along the axial direction at a position in the outer peripheral surface thereof which is circumferentially offset from the grooves 17a and 17b on the inner peripheral surface. The groove 24 is provided on both sides of the side cover 10.
A reservoir 25 is formed between A, 10B and the cylindrical case 11. The reservoir 25 is positioned vertically above the rotary damper 1 in a state where the rotary damper 1 is attached to the vehicle body 6. A predetermined amount of gas is sealed inside the reservoir 25 through a gas sealing plug 26 provided in the cylindrical case 11, and a volume change accompanying a temperature change of the liquid in the damper housing 3 is absorbed by the elasticity of the gas. It is supposed to. The amount of gas charged into the reservoir 25 is set such that the liquid level in the reservoir 25 is higher than the pressure chamber in a low temperature state. In the drawing, reference numeral 27 denotes a positioning groove formed in the outer peripheral surface of the housing body 9 along the axial direction, and a positioning pin 28 is fitted in the positioning groove 27 so as to protrude in both axial directions. .

On the other hand, both side covers 10A, 10B
As shown in FIG. 1, central holes 29A and 29B into which the input / output shafts 4 are fitted are formed, and the central holes 29A and 29B have bearing grooves 30A and 30B and seal grooves 31 respectively.
A and 31B are formed adjacent to each other in the axial direction. Of these, the seal grooves 31A and 31B are disposed axially outside the bearing grooves 30A and 30B, and the bearing grooves 30A and 30B
B, the input / output shaft 4 has side covers 10A, 10B.
A bearing 32 for rotatably supporting the housing is accommodated in the seal grooves 31A and 31B, and an annular seal member 33 for preventing leakage of liquid from a gap between the input / output shaft 4 and the side covers 10A and 10B. Is housed. And
Bearing groove 30A, 30B of each side cover 10A, 10B
And the seal grooves 31A and 31B are provided in the side covers 10A and 10B.
The center holes 29A and 29B of B and the gap between the outer peripheral surface of the input / output shaft 4 communicate with each other, and they form a pair to form a housing space in the present invention. In the case of this embodiment, the right bearing groove 30A and the seal groove 31A in FIG. 1 constitute a first accommodation space, and the left bearing groove 30B
And the seal groove 31B constitute a second accommodation space.

Also, both side covers 10A, 10B
A small-diameter annular groove 34 and a large-diameter annular groove 35 are formed concentrically on the end face of the housing body 9 side.
35 constitutes a part of a liquid passage described later. In the following, the side cover located on the left side in FIGS. 4 and 5 (located on the right side in FIG. 1) is the first side cover 10A, and the side cover located on the right side is the second side cover. 10B.

As shown in detail in FIGS. 4 and 5, between the one end face of the housing body 9 and the first side cover 10A, four thin plates 36, 37, 38,
39 are sandwiched in a superposed state, and one thin plate 40 is sandwiched between the other end surface of the housing body 9 and the second side cover 10B. These thin plates 36
40 are all formed in an annular shape having substantially the same outer diameter as the housing body 9, and a notch 41 formed in each outer peripheral surface is fitted into a positioning pin 28 fitted in the housing body 9, and is formed in a circumferential direction. Has been positioned. The center holes of the plates 36 to 40 are formed slightly larger than the outer diameter of the input / output shaft, and annular passages 42 and 43 are formed between the plates 36 and 40 and the outer peripheral surface of the input / output shaft 4. (See FIG. 1).

The specific structure of each of the thin plates 36 to 40 will be described below. The four thin plates on the first side cover 10A side are the first plate 36 and the second plate 37 in order from the left side in FIG. , Third plate 38, fourth
The plate on the side of the second side cover 10 </ b> B will be referred to as a fifth plate 40. Each of the plates 36 to 40 is connected to each of the liquid chambers 22a,
Since each of the four quarter regions in the circumferential direction corresponding to 22b, 23a, and 23b has a characteristic structure, the region corresponding to the first left chamber 22a corresponds to the L-1 region and the second left room 22b for convenience of explanation. The area corresponding to the right first chamber 23a is called an L-2 area, the area corresponding to the right first chamber 23a is called an R-1 area, and the area corresponding to the right second chamber 23b is called an R-2 area.

The L-2 and R-1 regions and the L-1 and R-2 regions of the first to fourth plates 36 to 39 have the same structure, respectively. The area contains the first
Small and large annular grooves 34, 35 of side cover 10A
Passages T ₁ and T ₂ are formed respectively to communicate the first and second left chambers 22 b and the first right chamber 23 a, and the annular grooves 34 and 35 are formed in the passages T ₁ and T _{2 from} the respective chambers 22 b and 23 a. A check valve 44 is provided to block the flow of liquid in the direction.

That is, L-2, R-1 of the first plate 36
The area has a pair of eyebrow-shaped holes 45a, 4a facing each other.
5b is formed, and in the L-2 and R-1 regions of the second plate 37, an arc hole 46 having a diameter slightly larger than that of the eyebrows 45a and 45b is formed. The tongue pieces are inserted into the eyebrows 45a, 45b.
The valve body 44a of the check valve 44 that opens and closes is formed. In the L-2 and R-1 regions of the third plate 38 and the fourth plate 39, a large-diameter valve operating hole 47 for allowing the valve body 44a to open in the direction of each of the chambers 22b and 23a is provided. , The valve operating hole 47 and each chamber 22
A communication hole 48 for communicating b and 23a is formed respectively. Then, the cocoon-shaped holes 45a and 45b, the arc holes 46, the large-diameter holes 47, and the communication holes 48 formed in the respective plates 36 to 39 are formed in the annular groove 3 of the first side cover 10A.
Passages T ₁ and T ₂ are formed to communicate the first and second left chambers 22b and the first right chamber 23a with the first and second chambers 4 and 35, respectively.

The L of the first to fourth plates 36 to 39
In the -1 area and the R-2 area, both annular grooves 34 and 35 of the first side cover 10A, the first left chamber 22a, and the second right chamber 23b are provided.
Are formed, and the passages T ₃ and T ₄ are respectively formed in the passages T ₃ and T _4.
A damping valve 49 is provided to prevent the flow of the liquid in the directions 2a and 23b and to provide a passage resistance to generate a damping force when the liquid flows from the chambers 22a and 23b toward the two annular grooves 34 and 35. Have been.

That is, the first plate 36 and the second plate 3
7, large-diameter valve actuation holes 50 and 51 are formed in the L-1 region and the R-2 region, respectively, and U-shaped holes 52 are formed in the L-1 region and the R-2 region of the third plate 38. Are formed in the L-1 region and the R-2 region of the fourth plate 39, as shown in FIG.
A small-diameter communication hole 53 communicating with each of the chamber 22a and the right second chamber 23b is formed. Further, the valve operating hole 50 of the first plate 36 is formed in the two annular grooves 3 of the first side cover 10A.
The tongue pieces which are communicated with 4 and 35 and cut off by the U-shaped hole 52 of the third plate 38 constitute a valve element 49 a of the damping valve 49. This valve element 49a closes the communication hole 53 of the fourth plate 39 when pressure is applied from the annular grooves 34 and 35, and conversely, when pressure is applied from each of the liquid chambers 22a and 23b. The U-shaped hole 52 is opened while imparting flow resistance to the liquid.

Further, a slit 54 (notch) having a predetermined length extending radially outward from a center hole of the first plate 36 is provided at a boundary between the L-1 region and the R-2 region of the first plate 36. Are formed, and the second to fourth plates 37 to 39 are formed.
Communication holes 55, 56, 57 (notches) communicating with the reservoir 25 are formed at positions corresponding to the extending ends of the slits 54. The slits 54 and the communication holes 55 to 57
Constitutes a first introduction path in the present invention, and introduces the liquid in the reservoir 25 through these into the bearing groove 30A and the seal groove 31A (first accommodation space) on the first side cover 10A side. Also, as shown in FIG.
Bearing groove 30A and seal groove 31A on the side cover 10A side
The annular passage 42 formed on the inner peripheral side of the first to fourth plates 36 to 39, the groove 16 formed on the inner peripheral surface of the boss portion 14 of the pressure receiving body 12, and the inner periphery of the fifth plate 40 It communicates with the bearing groove 30B and the seal groove 31B on the second side cover 10B side through an annular passage 43 formed on the side. The annular passages 42 and 43 and the groove 16 constitute a second introduction passage in the present invention. Furthermore, the slit 54 is
It is formed so as to intersect at least with the small-diameter annular groove 34 of the first side cover 10A. It is designed to be electrically connected to the reservoir 25 via 35. Therefore, the inside of the reservoir 25 is set to the same pressure as the low pressure side of the damping valve 49, and is always maintained at a stable low pressure.

On the other hand, the fifth plate has L-1, L-2,
Communication holes 58, 59, 60, 6 are formed in the respective regions of R-1 and R-2.
1 is formed. Of these, the communication holes 58 and 60 in the L-1 region and the R-1 region are formed at positions on the same circumference as the large-diameter annular groove 35 of the second side cover 10B.
The first left chamber 22a and the first right chamber 23a communicate with each other through the large-diameter annular groove 35. Similarly, the communication holes 59 and 61 in the L-2 region and the R-2 region are provided in the second side cover 1.
0B is formed at a position on the same circumference as the small-diameter annular groove 34, and the left second chamber 22b and the right second chamber 23b are connected to the small-diameter annular groove 34.
It is made to communicate through.

Therefore, the left pressure chamber 20 and the right pressure chamber 21
Of the left first chamber 22a and the right first
The chamber 23a, the second left chamber 22b, and the second right chamber 23b communicate with each other, and each function as a set of liquid chambers. For this reason, if the vanes 15a and 15b now rotate counterclockwise in FIG. 5 with respect to the damper housing 3, the liquid inside the first left chamber 22a and the right first chamber 23a is pressurized, The liquid inside these is used as the damping valve 49 in the L-1 region.
The valve body 49a is opened to flow out into the annular grooves 34, 35 of the first side cover 10A, and at the same time, the annular grooves 34, 35
Is the valve body 44a of the check valve 44 in the L-2 region.
And flows into the left second chamber 22b and the right second chamber 23b. At this time, a damping force is generated in the damping valve 49 in the L-1 region. On the other hand, when the vanes 15a and 15b rotate in the clockwise direction in FIG. 5 with respect to the damper housing 3, the liquid in the second left chamber 22b and the right second chamber 23b is pressurized, and the inside of these chambers is compressed. Liquid is in the R-2 region damping valve 49
The valve body 49a is opened to flow out into the annular grooves 34, 35 of the first side cover 10A, and at the same time, the annular grooves 34, 35
Is the valve body 44a of the check valve 44 in the R-1 region.
And flows into the right first chamber 23a and the left first chamber 22a, and at this time, a damping force is generated in the damping valve 49 in the R-2 region.

The housing body 9 and the side covers 10A and 10B on both sides are pressed into the cylindrical case 11 together with the respective plates 36 to 40, and in this state, both ends of the cylindrical case 11 are caulked so that they are in close contact with each other. And are combined.

A rod (not shown) is press-fitted into the input / output shaft 4, and this rod portion is rotatably held by a bracket 5 on the vehicle body side.

Since the rotary damper 1 is configured as described above, when the damper housing 3 is rotated with respect to the input / output shaft 4 with the rotation of the suspension link 2, the rotary damper 1 is in the L-1 area or the R-2 area. The damping valve generates a damping force, and the damping force buffers vibrations and impacts acting on the suspension link 2.

In the rotary damper 1, the liquid in the damper housing 3 is supplied to the left and right bearings 32 for supporting the input / output shaft 4 and the seal members 33 adjacent to these bearings 32, and these lubrications are provided. The bearing 32 and the sealing member 33
Since the liquid introduced into the reservoir is a liquid in the reservoir which is constantly kept at a low pressure, the seal member 33 is not specially designed for high pressure, and without adopting a decompression structure for reducing the pressure of the liquid. Leakage of the liquid through the outer peripheral surface of the input / output shaft 4 can be reliably prevented. Therefore, leakage of the liquid in the damper housing 3 can be reliably prevented without increasing the manufacturing cost in the rotary damper 1.

In the case of the rotary damper 1, the first
The grooves 30A and 31A on the side cover 10A side and the reservoir 2
5 are communicated with the slits 54 formed in the plates 36 to 40 through the communication holes 55, 56, 57, and the grooves 30A, 31A on the first side cover 10A side and the second side cover 10
The groove 16 in which the B-side grooves 30B and 31B are formed in the pressure receiving body 12
The first side cover 10A and the second side cover 10
Reservoir 2 in grooves 30A, 31A and 30B, 31B of B
The low-pressure introduction path for introducing the liquid No. 5 can be formed extremely easily, and therefore, the cost can be reduced. In this embodiment, the groove 16 communicating the grooves 30A and 31A on the first side cover 10A side and the grooves 30B and 31B on the second side cover 10B side is formed on the pressure receiving body 12 side. The groove 16 may be formed on the input / output shaft 4 side.

However, in the rotary damper 1 of this embodiment, since the groove 16 is formed in the pressure receiving body 12, the groove 16 is easily formed by a mold when the entire pressure receiving body 12 is formed by powder metallurgy. be able to. Therefore,
When the structure of this embodiment is employed, the manufacturing cost can be further reduced.

Further, in the rotary damper 1, the slits 54 and the communication holes 55 to 57 are formed in the plates 36 to 39 sandwiched between the housing body 9 and the first side cover 10A, so that the first side Cover 10A
The first grooves are formed so as to communicate the side grooves 30A, 31A with the reservoirs 25, so that the first grooves can be formed only by press-molding each plate, which also reduces the manufacturing cost. It is possible to achieve.

[0035]

As described above, the invention according to claim 1 is
Since the low-pressure introduction path that connects the storage space for housing the bearing and the seal member in the damper housing and the reservoir is provided, the liquid in the reservoir that is always maintained at a substantially constant low pressure is supplied to the bearing and the seal member. As a result, it is possible to reliably prevent the liquid from leaking to the outside of the damper housing without using a special decompression structure or a high-pressure seal member.

According to a second aspect of the present invention, in the first aspect, the housing space for housing the bearing and the seal member in the damper housing is the first housing arranged at one end of the input / output shaft. And a second housing space arranged on the other end side of the input / output shaft, and a low-pressure introduction passage connects a reservoir to the first housing space.
The reservoir is constituted by an introduction path and a second introduction path formed in the input / output shaft or the pressure receiving body along the axial direction and connecting the first accommodation space and the second accommodation space. The passage connecting the first housing space and the second housing space can be formed so as to be the shortest distance, and as a result, both sides of the input / output shaft can be formed. It is possible to easily form a low pressure introduction path for introducing the liquid in the reservoir into the storage space.

According to a third aspect of the present invention, in the second aspect of the present invention, the input / output shaft and the pressure receiving body are formed separately, and the input / output shaft and the pressure receiving body are fitted and fixed. Since the second introduction path is formed on the body-side fitting surface, the second introduction path can be simultaneously formed on the fitting surface of the pressure receiving body with the input / output shaft when the pressure receiving body is formed by molding. This makes it possible to more easily form the low-pressure introduction passage.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the damper housing comprises:
The housing body in which the pressure chamber and the reservoir are formed, and the side cover in which the housing space is formed are formed separately, and a thin plate is sandwiched and fixed between the housing body and the side cover. Notches such as slits and holes that constitute the low-pressure introduction path are formed, so that the low-pressure introduction path can be formed mainly by press-forming a thin plate, and as a result, the low-pressure introduction path is further improved. It can be easily formed.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along the line AA of FIG. 3 showing one embodiment of the present invention.

FIG. 2 is a side view showing the same embodiment.

FIG. 3 is a sectional view taken along the line BB of FIG. 1 showing the embodiment.

FIG. 4 is an exploded perspective view showing the same embodiment.

FIG. 5 is an exploded perspective view showing the same embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rotary damper, 3 ... Damper housing, 4 ... Input / output shaft, 9 ... Housing main body, 10A, 10B ... Side cover, 12 ... Pressure receiving body, 16 ... Groove (2nd introduction path), 20, 21 ... Pressure chamber, 22a: left first chamber (liquid chamber), 22b: left second chamber (liquid chamber), 23a: right first chamber (liquid chamber), 23b: right second chamber (liquid chamber), 30A, 30B: bearing groove (Accommodation space), 31A, 31B: Seal groove (accommodation space), 32: Bearing, 33: Seal member, 36: First plate (thin plate), 37: Second plate (thin plate), 38: Third plate (Thin plate), 39: fourth plate (thin plate), 40: fifth plate (thin plate), 44: check valve, 49: damping valve, 54: slit (first introduction path), 55, 56, 57 … Communication (First introduction path).

Claims (4)

[Claims] An input / output shaft is rotatably supported by a damper housing having a pressure chamber via a bearing, and a seal member for sealing a space between the damper housing and the input / output shaft outside the bearing in the axial direction. Is disposed, a pressure receiving body supported by the input / output shaft is slidably accommodated in the pressure chamber, and the inside of the pressure chamber is separated into a plurality of liquid chambers by the pressure receiving body. The liquid chamber that contracts with the operation of and the liquid chamber that expands are connected by a communication path, and a damping valve is interposed in this communication path.
In a rotary damper in which a reservoir for compensating for a volume change of a liquid is connected to a low-pressure side of the damping valve, a low-pressure introduction path for communicating a housing space for housing the bearing and the seal member in the damper housing with the reservoir. A rotary damper comprising: 2. The storage space includes: a first storage space disposed on one end of an input / output shaft; and a second storage space disposed on the other end of the input / output shaft. A low-pressure introduction path is formed along the axial direction on the input / output shaft or the pressure receiving body, the first introduction path connecting a reservoir to the first accommodation space, and the first accommodation space is connected to the second accommodation space.
2. The rotary damper according to claim 1, further comprising: a second introduction path connecting the storage spaces. 3. The input / output shaft and the pressure receiving body are formed separately, the input / output shaft and the pressure receiving body are fitted and fixed, and the second introduction path is formed on a fitting surface on the pressure receiving body side. The rotary damper according to claim 2, wherein: 4. The damper housing is divided into a housing body in which the pressure chamber and the reservoir are formed, and a side cover in which the housing space is formed, and is formed between the housing body and the side cover. The rotary damper according to any one of claims 1 to 3, wherein a thin plate is sandwiched and fixed, and a notch constituting the low-pressure introduction path is formed in the thin plate.