JPH043140Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an improvement of a damping force adjustment structure of a hydraulic shock absorber.

[Conventional technology]

There have been various proposals for damping force adjustment structures for hydraulic shock absorbers, for example,
There is a proposal as shown in Figure 3.

That is, a piston part 3 is disposed at the tip of a piston rod 2 inserted into the cylinder 1, and the piston part 3 divides the inside of the cylinder 1 into an upper chamber a and a lower chamber b. , a damping valve 3a disposed on the piston portion 3 when the piston portion 3 slides within the cylinder 1;
A flow of oil is caused between the upper chamber a and the lower chamber b via 3b, and predetermined damping forces on the expansion side and compression side are generated by this oil flow.

On the other hand, a side passage c is formed in the piston rod 2 to allow communication between the upper chamber a and the lower chamber b.
It communicates with horizontal holes 2a and 2b in two stages, upper and lower. A rotary valve 4 is rotatably housed in the side passage c, and a sleeve 5 is provided near the opening on the side of the upper chamber a of the horizontal holes 2a and 2b to close the opening. are slidably arranged.

The rotary valve 4 is connected to the lower end of a rotary rod 4a that is disposed so as to pass through the axial center of the piston rod 2, and is arranged so as to face the horizontal holes 2a and 2b when the rotary rod 4a is rotated. A plurality of ports 4b, 4c formed
have. The sleeve 5, which is disposed so as to be able to close the horizontal holes 2a and 2b, is biased upward from below by a spring 5a, and when it is lowered, the sleeve 5 closes the horizontal holes 2a and 2b. It is something that blocks the. Furthermore, a cushion 5b is attached to the upper end of the sleeve 5,
When the piston part 3 moves up the cylinder 1 to its fullest extent, the cushion 5b comes into contact with a bearing part (not shown) in the cylinder 1, and the sleeve 5
is formed so that it descends.

Note that a set nut 6 is provided at the tip of the piston rod 2 to fix the piston portion 3 in a predetermined position.
The set nut 6 has a leaf valve 6a arranged to close the opening on the side of the lower chamber b of the side passage c.

Therefore, since the piston part 3 is formed as described above, during the extension stroke when the piston part 3 moves up inside the cylinder 1, the oil in the upper chamber a flows into the lower chamber through the damping valve 3b on the extension side of the piston part 3. flows into b,
A predetermined high damping force at the so-called hard state is generated, and the damping force flows into the lower chamber b via the side passage c opened by the rotational operation of the rotary valve 4 and the leaf valve 6a in the set nut 6, A so-called soft damping force is generated.

When the piston portion 3 approaches the upper end of the cylinder 1 during full extension, the sleeve 5 descends to close the open side passage c, resulting in a so-called locked state.

In addition, during the pressure stroke in which the piston part 3 descends within the cylinder 1, oil in the lower chamber b flows into the upper chamber a via the damping valve 3a on the pressure side of the piston part 3, and a predetermined high damping force is generated. At the same time, the leaf valve 6 in the set nut 6 opens when the side passage c is opened.
The damping force flows into the upper chamber a through the ports 4b and 4c of the rotary valve 4 and the horizontal holes 2a and 2b of the piston rod 2, and a low damping force is generated.

[Problem that the invention attempts to solve]

However, in the damping force adjustment structure according to the conventional proposal described above, the port 4b of the rotary valve 4 in the so-called soft mode using the side passage c,
4c will be used both during the extension stroke and compression stroke of the piston portion 3, and therefore, for example, the type of vehicle equipped with the hydraulic shock absorber, the driving situation, the loading situation, etc. There is a disadvantage that it is not possible to adjust the damping force on the rebound side or compression side separately and independently depending on the soft condition.

In addition, in the above-mentioned conventional proposal, the lowering of the sleeve 5 to bring about the so-called locked state at the time of extension and cutting is also due to the fact that the horizontal holes 2a and 2b are formed in two stages, upper and lower. It is necessary to ensure large and smooth sliding motion, and there is the disadvantage that high machining accuracy is required over a wide range between the piston rod 2 and the sleeve 5.

Therefore, in view of the above-mentioned circumstances, the present invention makes it possible to adjust the damping force separately and independently for each compression side on the rebound side, and to reduce the range of high processing accuracy between the sleeve and the piston rod. The present invention aims to provide a new damping force adjustment structure for a hydraulic shock absorber.

[Means for solving problems]

In order to solve the above-mentioned problems, the configuration of the present invention is such that a piston rod is movably inserted into a cylinder via a piston body, and the piston body partitions an upper chamber and a lower chamber in the cylinder. forms an extension side oil passage and a pressure side oil passage that communicate the upper chamber and the lower chamber, a growth side valve is provided at the outlet end of the extension side oil passage to open and close freely, and a compression side valve is provided at the outlet end of the compression side oil passage to open and close. In a hydraulic shock absorber, a vertical side passage is provided in the piston rod to communicate the upper chamber and the lower chamber, and a rotary valve is rotatably inserted into this side passage. A sleeve body is vertically slidably inserted above the outer periphery of the holder, and an extension side lateral passage and a compression side lateral passage are provided in two stages between the piston rod and the holder to communicate the upper chamber with the side passage,
The rotary valve is formed with a plurality of orifices with different diameters that are opened and closed in the above-mentioned growth side lateral passage, and a plurality of orifices with different diameters that are opened and closed in the compression side lateral passage, and extends in the middle of the growth side lateral passage. The present invention is characterized in that a check valve that opens during compression is provided, and a check valve that opens during compression is provided in the middle of the compression side lateral passage.

〔Example〕

Hereinafter, the present invention will be explained based on the illustrated embodiments.

FIG. 1 shows a hydraulic shock absorber according to an embodiment of the present invention, which has a piston portion 13 at the tip of a piston rod 12 inserted into a cylinder 11. The inside of the cylinder 11 is divided into an upper chamber A and a lower chamber B by the piston portion 13, and the upper chamber A extends from the lower end of the piston rod 12 to the vicinity of the lower end.
It has a side passage C that allows communication between the lower chamber B and the lower chamber B. A rotary valve 14 is rotatably housed in the side passage C, and a rotary valve 14, which is rotated by an operation from outside the hydraulic shock absorber, is rotatably housed.
is arranged in the holder 15, and a sleeve body 16 is disposed in the holder 15.
is slidably inserted.

The piston portion 13 has a piston body 13a that partitions the inside of the cylinder 11 into an upper chamber A and a lower chamber B.
In addition, the piston body 13a has:
It has a compression side oil passage 13b and an expansion side oil passage 13c that allow communication between the upper chamber A and the lower chamber B.
A compression side valve 13d is disposed on the seat surface on the upper chamber A side of the piston body 13a so as to close the upper end opening of the pressure side oil passage 13b, and on the seat surface on the lower chamber B side, the compression side valve 13d is disposed. An expansion side valve 13e is arranged to close the lower end opening of the expansion side valve 13e.

The pressure side valve 13d is connected to the holder 15 via the ring seat 13f so that the inner peripheral end is fixed.
The piston body 13a is held under clamping pressure between the lower end of the piston body 13a and the upper end of the inner circumferential side of the piston body 13a, and is formed so that a predetermined initial load is applied by a spring 13g locked to the holder 15. ing.

Furthermore, the extension valve 13e is located between the upper end of a set nut 13i screwed onto the lower end of the piston rod 12 via the ring seat 13h and the inner lower end of the piston body 13a so that the inner peripheral end is fixed. The clamping pressure is maintained, and the set nut 1
A predetermined damping force can be generated by abutment from the lower surface of the plate valve 13k energized by a spring 13j engaged with the plate valve 3i.

The rotary valve 14 has a rotary rod 14a connected to its upper end, and the rotary rod 14a passes through the axial center of the piston rod 12 so that its upper end protrudes to the outside, and an appropriate actuator (not shown) is connected to the protruding end. ) can be connected. The rotary valve 14 is prevented from falling downward by a stopper 14b housed in the side channel C.

The rotary valve 14 has a plurality of adjusting orifices 14c, 14d with different diameters in the upper circumferential direction, and other adjusting orifices 14e, 14d.
4f are perforated in the circumferential direction below it. And the adjustment orifice 14c, 14
d, 14e, 14f are piston rods 12
An extension side lateral hole 12 serving as an extension side lateral passage bored in the
a, and a compression side lateral hole 12b which is a compression side lateral passage.

The extension side lateral hole 12a is an annular-shaped extension port 15a formed on the inner circumferential surface of the holder 15, which is a growth side lateral passage that is bored in the upper half of the holder 15 and opens into the upper chamber A. They are communicated via the groove 15b. Then, the compression side horizontal hole 12
b is bored in the lower half of the holder 15 and the upper chamber A
A pressure side port 15c which is a pressure side lateral passageway opening to
The piston rod 12 is connected to the piston rod 12 through an annular groove 12c formed on the outer circumferential surface of the piston rod 12.

Also, a check valve 17 is housed in the annular groove 15b, which allows oil to flow only from the upper chamber A side to the inner passage C side of the piston rod 12, and is housed in the annular groove 12c. is equipped with a check valve 18 that only allows oil to flow from the side channel C side to the upper chamber A side.

Sleeve body 1 interposed in the holder 15
6 is slidably held on the outer periphery of the piston rod 12, and the cylindrical portion 16a of the sleeve body 16 is bored into the upper half of the holder 15 when the sleeve body 16 is lowered. It is formed so as to close the expansion side port 15a. The sleeve body 16 is biased upward by a spring 16b locked to the upper end of the holder 15, and normally the cylindrical portion 16a opens the extension port 15a. It is formed as if it were in a state.

A cushion member 16c is attached to the upper end surface of the sleeve body 16, and when the cushion member 16c comes into contact with a bearing member (not shown) disposed at the upper end of the cylinder 1,
The spring 16b is formed to be compressed.

Therefore, the operation of the damping force adjustment structure for a hydraulic shock absorber formed as described above will be briefly explained.

First, when the piston portion 13 in the cylinder 11 is in the upward stroke and the rotary valve 14 is rotated to open the side passage C, the oil in the upper chamber A is transferred to the oil on the expansion side of the piston body 13a. Road 1
At the same time, the oil flows into the lower chamber B by lowering the outer peripheral end of the extension valve 13e, and part of the oil in the upper chamber A flows into the extension port 15a of the holder 15. At the same time, the check valve 17 is pushed open, and the water flows into the side passage C via the expansion side horizontal hole 12a of the piston rod 12 and the adjustment orifice 14d of the rotary valve 14. and,
The oil that has flowed into the side channel C will flow out into the lower chamber B, and the oil that has flowed into the side channel C will flow out into the lower chamber B, and the oil that has flowed into the side channel C will flow out into the lower chamber B, and
When oil passes through, a predetermined damping force adjustment is performed.

In the above state, when the rotary valve 14 is rotated, the extension side horizontal hole 12 of the piston rod 12
The adjustment orifice 14d opposite to a is used as another adjustment orifice 14c, and different damping force adjustments are made.

Note that during the above extension stroke, the check valve 18
Since the pressure side hole 12b of the piston rod 12 is closed, it goes without saying that oil in the upper chamber A does not flow into the side passage C through the pressure side port 15c of the holder 15. When the pressure stroke starts, the oil in the lower chamber B flows into the upper chamber A via the pressure side valve 13d of the piston part 13, and at the same time,
A portion of the oil in the lower chamber B flows into the side channel C. Then, the oil that has flowed into the side passage C is transferred to the expansion side port 15.
Since a is closed by the check valve 17,
It flows into the pressure-side horizontal hole 12b through the adjustment orifice 14e, and also flows into the upper chamber A through the pressure-side port 15c by pushing open the check valve 18. As a result, the predetermined compression side damping force is adjusted.

Next, when the hydraulic shock absorber approaches the fully extended state in the operating state of the extension stroke, the cushion member 16 attached to the upper end of the sleeve body 16
c comes into contact with a bearing member (not shown) at the upper end of the cylinder 1, and by contacting the cushion member 16c with the bearing member,
The spring 16b is compressed and the sleeve body 1
6 slides down the upper half of the holder 15.

When the sleeve body 16 descends, the sliding portion 16a closes the opening on the A side of the upper chamber of the growth side port 15a, which is bored in the holder 15 and opens, so that the growth side port 15a and the side passage are closed. The oil in the upper chamber A is prevented from flowing into the lower chamber B through C, resulting in a state close to a so-called oil lock state, and collision of the piston portion 13 with the upper end of the cylinder 1 is avoided. Become.

Therefore, the flow of oil through the side passage C between the upper chamber A and the lower chamber B during the extension stroke in which the piston portion 13 ascends within the cylinder 1 and in the pressure stroke in which it descends is adjusted separately. Since this is done through an orifice, it is possible to adjust the rebound damping force and the compression damping force separately, and it is also possible to obtain a so-called oil lock state at the end of extension. , it is sufficient that the sleeve body 16 slides only between the upper half of the holder 15.

FIG. 2 shows a damping force adjustment structure for a hydraulic shock absorber according to another embodiment of the present invention, and in this embodiment, the structure of the sleeve body 16 is modified. It has characteristics.

That is, a C pin 16d is interposed on the outer peripheral surface of the piston rod 12 inside the sleeve body 16,
An annular groove 16e is formed on the inner surface of the sleeve body 16, through which the C pin 16d can be inserted.

As a result, when the sleeve body 16 descends during so-called extension, the C pin 1
6d can bear the load, and therefore, there is an advantage that the spring 16b supporting the sleeve body 16 can be made smaller than the spring 16b of the embodiment described above.

As shown in the figure, if a caulked portion 16f is formed at the lower end edge of the annular groove 16e, vertical movement of the sleeve body 16 due to the reaction force and vibration of the spring 16b can be prevented. Become.

The embodiments shown in FIGS. 1 and 2 are both designed to enable so-called oil locking when the hydraulic shock absorber is fully extended. Similarly, when the passage opening on the expansion side is closed, the sleeve body 16 may slide at the extreme stage of the compression side stroke to close the passage opening on the compression side, thereby obtaining a so-called oil lock state during the compression side. Of course.

[Effect of idea]

As described above, according to the present invention, the extension side lateral passage, the compression side lateral passage, and the orifice opened and closed in these passages are provided in two stages, and the Since the check valve is provided in the engine, there is an advantage that the damping force on the rebound side and the compression side can be generated separately and independently, and each damping force can be adjusted to a desired magnitude.

As a result, according to the hydraulic shock absorber having the damping force adjustment structure according to the present invention, the damping force can be adjusted according to the driving conditions of the vehicle, and the damping force can also be adjusted according to the preferences of the driver of the vehicle. You can also get the same effect as you would like.

In addition, according to the present invention, since the sleeve body is slidably provided on the outer periphery of the holder, it is possible to prevent the piston part from colliding with the upper end of the cylinder when it is fully extended when making the so-called soft damping force adjustment. At that time, the sleeve body only needs to slide in a small range such as the upper half of the holder, and there is no need for machining accuracy between the sleeve and the piston rod over a long stroke as in the conventional example. There are distinct advantages.

[Brief explanation of the drawing]

Fig. 1 is a partial vertical sectional view showing a hydraulic shock absorber according to an embodiment of the present invention, Fig. 2 is a view showing another embodiment in the same manner as Fig. 1, and Fig. 3 is a diagram showing a conventional hydraulic shock absorber. FIG. 11...Cylinder, 12...Piston rod,
13...Piston part, 14...Rotary valve,
15...Holder, 16...Sleeve body, A...Upper chamber, B...Lower chamber, C...Side channel.

Claims (1)

[Claims for Utility Model Registration] (1) A piston rod is movably inserted into the cylinder via a piston body, the piston body divides the cylinder into an upper chamber and a lower chamber, and the piston body has an upper chamber and a lower chamber. forming an extension side oil passage and a pressure side oil passage communicating with the lower chamber, providing an extension side valve at the outlet end of the extension side oil passage so as to be freely openable and closable, and providing a compression side valve at the outlet end of the compression side oil passage so as to be freely openable and closable; Furthermore, a vertical side passage is provided in the piston rod to communicate the upper chamber and the lower chamber, and in a hydraulic shock absorber in which a rotary valve is rotatably inserted into this side passage, a holder is provided on the outer periphery of the piston rod, and a holder is provided on the outer periphery of the piston rod. A sleeve body is vertically slidably inserted above the outer periphery of the rotary valve, and the piston rod and the holder are provided with two stages of extension-side lateral passages and compression-side lateral passages that communicate the upper chamber with the side passage. A plurality of orifices with different diameters that are opened and closed in the side lateral passage and a plurality of orifices with different diameters that are opened and closed in the compression side lateral passage are formed, and a check valve that opens during expansion is provided in the middle of the extension side lateral passage. , a damping force adjustment structure for a hydraulic shock absorber with a check valve that opens during compression in the middle of the compression side lateral passage. (2) A damping hydraulic shock absorber according to claim 1 of the utility model registration claim, in which annular grooves are provided in two stages between the piston rod and the holder, and a check valve is disposed in each annular groove so as to be openable and closable. Force adjustment structure. (3) The damping force adjustment structure for a hydraulic shock absorber according to claim 1, wherein a cushion member is attached to the upper end of the sleeve body.