JPH06300072A - Damping force control type hydraulic buffer - Google Patents

Abstract

PURPOSE:To control the damping force by the extension/shrinkage respectively, and to enlarge a stroke of a piston rod of a hydraulic buffer. CONSTITUTION:A piston 7, to which a piston rod 8 is connected, is fitted inside of a cylinder 2. The piston 7 is provided with oil passages 13, 14 for extension/ shrinkage and disc valves 15, 16. Inner cylinders 3, 27 are provided outside of the cylinder 2 to form a first and a second annular passages. An outer cylinder 4 is provided outside of the inner cylinders 3, 27 to form a reservoir chamber 6. The side surface of the cylinder 2 is provided with a guide 23 and a damping force control valve formed of a shutter. A cylinder upper chamber 2a is communicated with the reservoir chamber 6 through the first annular passage 5 and a port 32 of the guide 23, and a cylinder lower chamber 2b is communicated with the reservoir chamber 6 through the second annular passage 27a and a port 33 of the guide 23. The shutter is rotated by a dial 38 to open/ close the ports 32, 33 and control the damping force by the extension and shrinkage respectively. Since the damping force control valve is not arranged in the piston 7, a stroke of the piston rod 8 can be enlarged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping force adjustable hydraulic shock absorber mounted on a suspension system of a vehicle such as an automobile.

In a hydraulic shock absorber installed in a suspension system of a vehicle such as an automobile, a damping force can be appropriately adjusted in order to improve ride comfort and steering stability in accordance with road surface conditions, running conditions and the like. There is a force adjustable hydraulic shock absorber.

Generally, in this type of hydraulic shock absorber, a piston in which a piston rod is connected is slidably fitted in a cylinder in which an oil liquid is sealed, and two chambers in the cylinder are defined by the piston. The main oil liquid passage and the bypass passage communicate with each other, the main oil liquid passage is provided with a damping force generating mechanism (orifice, disk valve, etc.) that generates a large damping force, and the bypass passage generates a small damping force. It is configured such that a generating mechanism (orifice, disc valve, etc.) and a damping force adjusting valve for opening and closing the bypass passage are provided.

With this configuration, when the damping force adjusting valve is opened, the sliding of the piston accompanying the expansion and contraction of the piston rod causes the oil liquid in the cylinder to flow mainly through the bypass passage to generate a small damping force. The damping force characteristic becomes a soft characteristic. In addition, when the damping force adjusting valve is closed, the sliding of the piston accompanying the expansion and contraction of the piston rod causes the oil liquid in the cylinder to flow only through the main oil liquid passage to generate a large damping force. It has hard characteristics. In this way, the damping force characteristic can be switched by opening and closing the damping force adjusting valve.

By the way, in a conventional damping force adjusting type hydraulic shock absorber, a main oil liquid passage is generally provided in a piston fitted in a cylinder, and a bypass passage is provided along an axial center of a piston rod penetrating the piston. Is provided, and a damping force control valve that opens and closes the bypass passage is provided at the tip of the piston rod. The operation rod for operating the damping force adjusting valve is inserted into the piston rod and protrudes from the end of the piston rod to the outside, and the operation rod is operated from the outside of the hydraulic shock absorber by an actuator or the like. The damping force can be switched.

[0006]

However, in the above-mentioned conventional damping force adjusting hydraulic shock absorber, since the bypass passage and the damping force adjusting valve are provided in the peripheral portion of the piston in the cylinder, the size of the peripheral portion of the piston is reduced. There is a problem that the piston rod becomes large and the expansion and contraction stroke of the piston rod becomes short. Further, since the actuator for operating the operation rod of the damping force adjusting valve is usually attached to the tip end portion of the piston rod connected to the vehicle body side of the vehicle, the actuator is attached to the piston rod attachment portion (strut mount etc.) on the vehicle body side. It is necessary to provide a space for mounting, which deteriorates the space efficiency on the vehicle body side. Therefore, especially at the piston rod mounting portion on the front wheel side of a passenger vehicle, it is against the requirement to lower the engine hood. Further, since the operation rod of the damping force adjusting valve is projected from the end of the piston rod, the shape of the end of the piston rod is limited, and there is a problem that the degree of freedom of the connecting structure to the vehicle body side is reduced.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a damping force adjustable hydraulic shock absorber in which the expansion / contraction stroke of the piston rod is increased by downsizing the piston portion. .

[0008]

In order to solve the above-mentioned problems, a damping force adjusting hydraulic shock absorber of the present invention is provided with a cylinder in which an oil liquid is sealed and a slidable fit in the cylinder. Between the piston that defines the inside of the cylinder into two chambers, the piston rod that has one end connected to the piston and the other end that extends to the outside of the cylinder, and the piston rod that is provided on the outer circumference of the cylinder An oil liquid is provided between an inner cylinder forming a first annular passage communicating with one chamber in the cylinder and a second annular passage communicating with the other chamber, and an inner cylinder provided on the outer periphery of the inner cylinder. And an outer cylinder forming a reservoir chamber in which gas is enclosed, an oil liquid passage provided in the piston for communicating two chambers in the cylinder, and a damping force by controlling the flow of the oil liquid in the oil liquid passage. A first damping force generating mechanism for generating the force; Base valve for communicating the inside of the chamber with the reservoir chamber, a check valve provided in the base valve for allowing the flow of the oil liquid from the reservoir chamber side to the cylinder side, and a check valve provided in the base valve from the cylinder side to the reservoir chamber A second damping force generation mechanism that controls the flow of the oil liquid to the side to generate a damping force, a first passage that communicates the first annular passage with the reservoir chamber, and a second annular passage. Of a damping force for adjusting the passage areas of the first and second passages by rotation of the shutter, and a second passage that communicates with the reservoir chamber, and a guide and a shutter provided on a side surface of the cylinder. And a valve.

[0009]

With this configuration, when the piston slides to the one side due to the expansion and contraction of the piston rod, the oil liquid in one chamber in the cylinder passes through the first annular passage and the first passage and becomes the reservoir chamber. And a damping force is generated according to the passage area of the first passage adjusted by the damping force adjusting valve,
Further, when the piston moves to the other side, the oil liquid in the other chamber in the cylinder flows to the reservoir chamber through the second annular passage and the second passage, and the second passage adjusted by the damping force adjusting valve Since the damping force is generated according to the passage area, the damping force characteristics on the extension side and the contraction side can be adjusted separately by rotating the shutter.

[0010]

Embodiments of the present invention will now be described in detail with reference to the drawings.

A first embodiment will be described with reference to FIGS. 1 to 3. As shown in FIGS. 1 and 2, the damping force adjustable hydraulic shock absorber 1 is provided with an inner cylinder 3 on the outer side of a cylinder 2.
Further, the outer cylinder 4 is provided outside the inner cylinder 3 to form a triple tube structure. A first annular passage 5 is formed between the cylinder 2 and the inner cylinder 3, and the inner cylinder 3 and the outer cylinder 3 are formed. A reservoir chamber 6 is formed between the first and second chambers.

A piston 7 is slidably fitted in the cylinder 2, and the cylinder 7 is fitted by the piston 7.
The inside is divided into two chambers, a cylinder upper chamber 2a and a cylinder lower chamber 2b. One end of a piston rod 8 is connected to the piston 7 by a nut 9, and the other end side of the piston rod 8 penetrates a rod guide 10 and a seal member 11 provided at an upper end portion of the cylinder 2 and the cylinder 2 Has been extended to the outside. A base valve 12 is provided at the lower end of the cylinder 2, and the cylinder lower chamber 2b and the reservoir chamber 6 are communicated with each other via the base valve 12. The cylinder 2 is filled with oil liquid, and the reservoir chamber 6 is filled with oil liquid and gas.

The piston 7 is provided with an extension-side oil liquid passage 13 and a compression-side oil liquid passage 14 which connect the cylinder upper chamber 2a and the cylinder lower chamber 2b. Then, on the end surface of the piston 7 on the cylinder lower chamber 2b side, a disk valve that allows only the flow of oil liquid from the cylinder upper chamber side of the extension side oil liquid passage 13 to the cylinder lower chamber 2b side to generate a damping force 15 is provided, and the end surface on the cylinder upper chamber 2a side is a disc that allows only the oil liquid to flow from the cylinder lower chamber 2b side of the compression side passage 14 to the cylinder upper chamber 2a side to generate a damping force. A valve 16 is provided. The disc valves 15 and 16 constitute a first damping force generating mechanism.

The base valve 12 is provided with an extension side passage 17 and a contraction side passage 18 which connect the cylinder lower chamber 2b and the reservoir chamber 6 to each other. Further, the check valve 19 which allows only the flow of the oil liquid from the reservoir chamber 6 side of the extension side passage 17 to the cylinder lower chamber 2b side and the cylinder upper chamber 2b of the contraction side passage 18 are provided.
A disk valve 20 is provided as a second damping force generation mechanism that generates a damping force by allowing only the flow of the oil liquid from the side to the reservoir chamber 6 side.

A cylindrical valve housing 21 is provided on the side surface of the lower end of the outer cylinder 4, and a damping force adjusting valve 22 is provided inside the valve housing 21. The damping force adjusting valve 22 is a cylindrical guide with a bottom inside the valve housing 21.
23 is inserted, a tubular plug 24 having a bottom is screwed into the opening of the valve housing 21 to fix the guide 23, and the shutter chamber is provided between the bottom of the guide 23 and the bottom of the plug 24.
24a is formed.

Inside the guide 23, there are provided two chambers 23a and 23b serving as first and second passages. Chamber 23a
Is communicated with the first annular passage 5 through the passage 26 of the passage member 25 fitted to the cylinder 2 and the inner cylinder 3, and the first annular passage 5 is provided with the passage 10a provided in the rod guide 10.
Is communicated with the cylinder upper chamber 2a via. Cylinder 2
The inner cylinder 27 is fitted to the outer side of the lower end of the inner cylinder 27 and the cylinder 2.
An annular passage 27a is formed between the chamber 23b and the chamber 23b.
Of the circular passage 27a.
a is communicated with the cylinder lower chamber 2b through a passage 29 provided in the base valve 12. In addition, in the guide 23, the room 23
A passage 30 for communicating a with the chamber 23b and a chamber of the passage 30
A check valve 31 that allows only the flow of the oil liquid from the 23b side to the chamber 23a side is provided.

At the bottom of the guide 23, there is a chamber 23a and a shutter chamber.
Port 32 and chamber 23b for communicating with 24a and shutter chamber
A port 33 is provided for communicating with 24a. The shutter chamber 24a communicates with the reservoir chamber 6 via a passage 34 formed between the valve housing 21 and the guide 23. A disk-shaped shutter 35 that opens and closes the ports 32 and 33 is provided in the shutter chamber 24a, and is pressed against the bottom of the guide 23 by a spring 36. An operating rod 37 is integrally attached to the shutter 35. The operating rod 37 is inserted into the bottom of the plug 24 to extend to the outside, and a dial 38 is attached to its tip. Then, the shutter 35 can be rotated by rotating the dial 38 from the outside. Further, the plug 24 is provided with a spring 39 and a latch ball 40,
It is designed to hold 38 in place.

As shown in FIG. 3, a plurality of (four in FIG. 3) ports 32a, 32b, 32c, 32d and a plurality of ports 32 and 33 (FIG. 3) are provided. 4) ports 33a, 33b, 33c, 33
The shutter 35 is provided with a cutout 35a and a cutout 35b at a position facing the port 32 and the port 33.
A part of 32 and a part of port 33 can be selectively opened to adjust the passage area of each.

The operation of the first embodiment constructed as above will be described below.

During the extension stroke of the piston rod 8, as the piston 7 slides, the oil liquid in the cylinder upper chamber 2a passes through the passage 10.
a through the first annular passage 5, the passage 26, the chamber 23a, the port 32, the shutter chamber 24a and the passage 34 to the reservoir chamber 6. At this time, the check valve 31 of the guide 23 is closed and the chamber 23a
Block distribution from room to room 23b. On the other hand, the oil liquid in the reservoir chamber 6 opens the check valve 19 of the base valve 12 and flows through the extension side passage 17 to the cylinder lower chamber 2b. Therefore, when the oil liquid flows through the port 32, a damping force is generated according to the passage area. In addition, the gas in the reservoir chamber 6 expands as much as the piston rod 8 moves out of the cylinder 2. When the extension speed of the piston rod 8 is high and the piston speed is high, the pressure in the cylinder upper chamber 2b rises, the disc valve 15 opens, and the oil liquid in the cylinder upper chamber 2a passes through the extension side oil liquid passage 13. The flow directly flows to the cylinder lower chamber 2b, and a damping force is generated by the disc valve 15.

During the compression stroke of the piston rod 8, as the piston 7 slides, the oil liquid in the cylinder lower chamber 2b passes through the passage 2
9, flowing to the second annular passage 27a, passage 28, chamber 23b. Room 2
The oil liquid of 3b flows into the shutter chamber 24a through the port 33, while opening the check valve 31 and flowing through the communication passage 30 into the chamber 23a. Part of the oil liquid in the chamber 23b is the passage 26 and the first annular passage 5
And through the passage 10a to the upper cylinder chamber, and partly through the port 32 to the shutter chamber 24a. Then, the oil liquid in the shutter chamber 24a flows into the reservoir chamber 6 through the passage 34. Therefore, when the oil liquid flows through the ports 32 and 33, a damping force is generated according to the total of the passage areas of the oil liquids. Further, the gas in the reservoir chamber 6 is compressed by the amount of the piston rod 8 entering the cylinder 2. When the shortening speed of the piston rod 8 is high and the piston speed is high, the pressure in the cylinder lower chamber 2b rises, and the oil liquid opens the disc valve 16 of the piston 7 and the compression side oil liquid passage 14
To the upper chamber 2a of the cylinder, and the disc valve 20 of the base valve is opened to flow directly to the reservoir chamber 6 through the contraction side passage 18, and a damping force is generated by the disc valve 16 and the disc valve 20.

As described above, the damping force is generated by the passage area of the port 32 during the extension stroke, and the port 32 is generated during the contraction stroke.
Since the damping force is generated by the passage area of the port 33, the damping force can be adjusted by operating the dial 38 from the outside to rotate the shutter 35 and changing the passage areas of the ports 32 and 33. In addition, since the flow resistance of the oil liquid decreases on the contraction side with respect to the expansion side by the passage area of the port 33, different damping force characteristics are obtained on the expansion side (large damping force) and the contraction side (small damping force). It can be set, and appropriate damping force characteristics can be obtained on both the extension side and the contraction side.

Further, a damping force adjusting valve 22 is provided on a side surface portion of the outer cylinder 4, and the piston 7 has an extension side oil liquid passage 13,
Since only the contraction side oil liquid passage 14 and the disc valves 15 and 16 are provided, the size of the piston portion does not become large unlike the above-mentioned conventional example, so that the expansion / contraction stroke of the piston rod 8 can be set sufficiently large. it can. Also,
Since the operation rod 37 of the damping force adjusting valve 22 does not project from the piston rod 8, the end shape of the piston rod 8 is not limited, and the degree of freedom of the connecting structure to the vehicle body side is increased.

Next, the second embodiment of the present invention will be described with reference to FIG.
And it demonstrates using FIG. The second embodiment is substantially the same as the first embodiment except that the annular passage and the damping force adjusting valve are different. Therefore, the same members as in the first embodiment will be designated by the same reference numerals. Only different parts will be described in detail.

As shown in FIGS. 4 and 5, the damping force adjusting hydraulic shock absorber 41 is provided with an inner cylinder 3a and an inner cylinder 3b outside the cylinder 2 and an outer cylinder 42 outside the inner cylinders 3a and 3b. Provided 3
It has a heavy-cylinder structure, and further, the cylindrical passage member 43 is externally fitted to the cylinder and both ends thereof are fitted to the inner cylinder 3a and the inner cylinder 3b so that the first passage is formed between the cylinder 2 and the inner cylinder 3a. An annular passage 5a is formed, and a second annular passage is formed between the cylinder 2 and the inner cylinder 3b.
5b is formed, and the reservoir chamber 6 is formed between the inner cylinder 3a and the inner cylinder 3b and the outer cylinder 42. First circular passage
5a communicates with the cylinder upper chamber 2a through a hole 2c provided in the side wall near the upper end of the cylinder 2, and the second annular passage 5b has a hole 2d provided in the side wall near the lower end of the cylinder 2.
Is communicated with the cylinder lower chamber 2b.

The disc valve 16 of the piston 7 is set to have a low valve opening pressure so as to act as a check valve.

A cylindrical valve housing 44 is provided on a side surface portion of the outer cylinder 42 opposite to the passage member 43, and a damping force adjusting valve 45 is provided inside the valve housing 44. There is. In the damping force adjusting valve 45, a bottomed tubular guide 46 is inserted into a valve housing 44, and a plug 47 is screwed into an opening of the valve housing 44 to fix the guide 46. Further, in the valve housing 44, passage members 48 and 49 having a cylindrical shape with a bottom are provided,
The passage members 48 and 49 are fixed such that the openings are in contact with the side walls of the passage member 43, the guides 46 are inserted into the bottoms, and the step portions on the side surfaces of the guides 46 are in contact with each other. Then, the passage member 48 and the guide
A first passage 50 is formed between 46, and the first passage 50 is formed.
Is communicated with the first annular passage 5a via a passage 51 provided on the side wall of the passage member 43. Further, a second passage 52 is formed between the passage member 49 and the passage member 48, and the second passage 52 is connected to the second annular passage 5b via the passage 53 provided on the side wall of the passage member 43. It is in communication. Further, the passage member 49
A passage 54 communicating with the reservoir chamber 6 is formed between the valve housing 44 and the valve housing 44. A guide port 55 communicating with the first passage 50, a guide port 56 communicating with the second passage 52, and a guide port 57 communicating with the passage 54 are provided on the side wall of the guide 46.

A shutter 58 having a bottomed cylindrical shape is rotatably fitted in the guide 46, and shutter ports 59 and 60 facing the guide ports 55, 56 and 57 are provided on the side wall of the shutter 58. , 61 are provided. The shutter ports 59 and 60 are composed of a plurality of ports arranged in parallel along the circumferential direction of the shutter 58 and having different diameters, so that the passage area formed by the guide ports 55 and 56 can be adjusted by rotating the shutter 58. Has become. Further, the guide port 57 and the shutter port 61 are always communicated with each other with a sufficient passage area.

An operating rod 62 is connected to the bottom of the shutter 58, and the operating rod 62 extends through the plug 47 to the outside of the valve housing 44 and is connected to the actuator 63. The shutter 63 can be rotated at a desired angle by the actuator 63. In FIG. 4, 64 is a dust cover, and 65 and 66 are mounting eyes.

The operation of the second embodiment constructed as above will be described below.

During the extension stroke of the piston rod 8, as the piston 7 slides, the oil liquid in the upper chamber 2a of the cylinder 2c
The oil liquid in the shutter 58 flows through the first annular passage 5a, the passage 51, the first passage 50, the guide port 56 and the shutter port 59 into the shutter 58, and the oil liquid in the shutter 58 has a small flow resistance. Through 57 to reservoir chamber 6. On the other hand, the oil liquid in the reservoir chamber 6 is
The check valve 19 is opened to flow through the extension side passage 17 to the cylinder lower chamber 2b. Therefore, when the oil liquid flows through the guide port 55 and the shutter port 59, a damping force is generated according to the passage area. In addition, the gas in the reservoir chamber 6 expands as much as the piston rod 8 moves out of the cylinder 2. When the extension speed of the piston rod 8 is high and the piston speed is high, the pressure in the cylinder upper chamber 2b rises, the disc valve 15 opens, and the oil liquid in the cylinder upper chamber 2a passes through the extension side oil liquid passage 13. Directly to the cylinder lower chamber 2b,
A damping force is generated by the disc valve 15.

During the compression stroke of the piston rod 8, the oil liquid in the lower cylinder chamber opens the disc valve 16 acting as a check valve along with the sliding movement of the piston 7, and passes through the contraction side oil liquid passage 14 to the upper cylinder chamber 2a. Flowing. At the same time, the oil liquid corresponding to the piston rod 8 having entered the cylinder 2 flows from the cylinder lower chamber 2b into the hole 2d, the second annular passage 5b, the passage 53, and the second passage.
Through the passage 52, the guide port 56, and the shutter port 60 into the shutter 58, and the oil liquid in the shutter 58 flows into the reservoir chamber 6 through the shutter port 61 and the guide port 57 having a small flow resistance. Therefore, by the oil liquid flowing through the guide port 56 and the shutter port 60,
A damping force is generated according to the passage area. Further, the gas in the reservoir chamber 6 is compressed by the amount of the piston rod 8 entering the cylinder 2. When the shortening speed of the piston rod 8 is fast and the piston speed is high, the cylinder lower chamber
The pressure of 2b rises, and the oil liquid opens the disc valve 20 of the base valve and passes through the contraction side passage 18 directly to the reservoir chamber 6
And a damping force is generated by the disc valve 20.

In this way, during the extension side stroke, the guide port
A damping force is generated by the passage area between 55 and shutter port 59, and guide port 56 and shutter port 60
Since a damping force is generated according to the passage area of and, the operating rod is operated by the actuator 63 to rotate the shutter 58, and the passage areas of the guide port 55 and the shutter port 59 and the guide port 56 and the shutter port 60 are changed. The damping force can be adjusted by. At this time, the damping force is generated by the passage areas of different ports on the extension side and the contraction side, so it is possible to set different damping force characteristics on the extension side and the contraction side, and it is possible to set appropriate damping forces on both the extension and contraction sides. Force characteristics can be obtained.

Further, as in the first embodiment, the damping force adjusting valve
Since 45 is provided on the side surface of the outer cylinder 42 and the piston 7 is provided with only the expansion side oil liquid passage 13, the contraction side oil liquid passage 14 and the disc valves 15 and 16, the size of the piston portion is Since it does not become large, the expansion and contraction stroke of the piston rod 8 can be set sufficiently large. Further, the operation rod 62 of the damping force adjusting valve 45 is the piston rod 8
Since it does not project from the end, the shape of the end portion of the piston rod 8 is not limited, so that the degree of freedom of the connecting structure to the vehicle body side is increased.

The damping force adjusting valve is not limited to those shown in the first and second embodiments as long as the passage areas of the two passages (first and second passages) can be adjusted by rotating the shutter. A thing can also be used.

[0036]

As described in detail above, according to the damping force adjusting hydraulic shock absorber of the present invention, when the piston slides to one side due to the expansion and contraction of the piston rod, the oil liquid in one chamber in the cylinder is removed. Flowing through the first annular passage and the first passage to the reservoir chamber, a damping force is generated according to the passage area of the first passage adjusted by the damping force adjusting valve, and the piston moves to the other side. Then, the oil liquid in the other chamber in the cylinder
Flows to the reservoir chamber through the annular passage and the second passage, and a damping force is generated according to the passage area of the second passage adjusted by the damping force adjusting valve. The damping force characteristics on the contraction side can be adjusted separately. As a result, different damping force characteristics can be set on the extension side and the contraction side, so that appropriate damping force characteristics can be obtained on both the extension side and the contraction side. Also,
Since the damping force adjusting valve is provided on the side surface of the cylinder and the size of the piston does not increase, the expansion / contraction stroke of the piston rod can be set sufficiently large. Further, since it is not necessary to project the operation rod of the damping force adjusting valve from the piston rod, the shape of the end portion of the piston rod is not limited, so that it is possible to increase the degree of freedom of the connecting structure of the piston rod to the vehicle body side. Produce the effect.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of the apparatus shown in FIG.

FIG. 3 is a vertical sectional view of a guide and a shutter taken along the line AA of FIG.

FIG. 4 is a vertical sectional view of a second embodiment of the present invention.

5 is an enlarged view of a main part of the apparatus shown in FIG.

[Explanation of symbols]

 1 Damping force adjusting hydraulic shock absorber 2 Cylinder 2a Cylinder upper chamber 2b Cylinder lower chamber 3 Inner cylinder 4 Outer cylinder 5 First annular passage 5a First annular passage 5b Second annular passage 6 Reservoir chamber 7 Piston 8 Piston rod 12 Base valve 13 Expansion side oil liquid passage (oil liquid passage) 14 Compression side oil liquid passage (oil liquid passage) 15,16 Disc valve (first damping force generating mechanism) 19 Check valve 20 Disc valve (second damping) Force generation mechanism) 22 Damping force adjustment valve 23 Guide 23a Chamber (first passage) 23b Chamber (second passage) 27 Inner cylinder 27a Second annular passage 35 Shutter 42 Outer cylinder 45 Damping force adjustment valve 46 Guide 50 1st passage 52 2nd passage 58 Shutter

Claims (1)

[Claims] 1. A cylinder in which an oil liquid is sealed, a piston slidably fitted in the cylinder to define two chambers in the cylinder, one end of which is connected to the piston and the other end of which is the cylinder. A piston rod extended to the outside of
An inner cylinder which is provided on the outer periphery of the cylinder and which forms a first annular passage communicating with one chamber in the cylinder and a second annular passage communicating with the other chamber between the cylinder and the cylinder;
An outer cylinder provided on the outer periphery of the inner cylinder to form a reservoir chamber in which oil liquid and gas are sealed, and an oil liquid passage provided in the piston for communicating the two chambers in the cylinder. A first damping force generating mechanism that controls a flow of the oil liquid in the oil liquid passage to generate a damping force; a base valve that communicates the inside of the cylinder with the reservoir chamber; and a reservoir provided in the base valve. A check valve that allows the flow of the oil liquid from the chamber side to the cylinder side, and a second damping force that is provided in the base valve and that controls the flow of the oil liquid from the cylinder side to the reservoir chamber side to generate a damping force. A generating mechanism, a first passage that communicates the first annular passage with the reservoir chamber, a second passage that communicates the second annular passage with the reservoir chamber, and a side surface of the cylinder. Guide and sha Consist data, the damping force adjustable hydraulic shock absorber, characterized by comprising a damping force adjusting valve for adjusting the passage area of the first and second passage by the rotation of the shutter.