JPH0531302Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a damping force generating device for a shock absorber for vehicles, particularly for four-wheeled vehicles.

A shock absorber is installed between the vehicle body and the axle of a four-wheeled vehicle to reduce the transmission of vibrations to the vehicle body due to changes in driving conditions or road surface conditions, and to ensure stable driving. is suspended.

As a damping force generating device for the above-mentioned shock absorber, a structure as shown in FIG. 1 has conventionally been adopted. That is, the piston 2 is slidably housed in the cylinder, and the inside of the cylinder 1 is divided into two oil chambers 4.
The piston 2 is fitted into one end of the piston rod 3, and the two oil chambers 4,
5 communicates with the piston 2 through through holes 6 and 7 extending parallel to the outside and inside. A non-return valve 9 is positioned on the seat surface 8 on the rod side (back side) of one of the through holes 6, and a spring 11 is interposed between the non-return valve 9 and the valve holder 10.
When the piston rod 3 moves in the extending direction, a minute orifice 12 is stamped on the seat surface 8 to release the hydraulic oil in the upper oil chamber 4 to the lower oil chamber 5. be.
A leaf valve 14 is positioned on the seat surface 13 of the other through hole 7 on the lower oil chamber 5 side, and is fastened to the piston rod 3 via a collar 15 that determines the support diameter of the leaf valve 14.

Further, there is a valve case 17 of the base valve at the bottom of the cylinder 1, and the valve case 17 is also provided with through holes 18 and 19 in parallel on the outside and inside. A non-return valve 22 is pressed by a spring 23 to a seat surface 21 on the lower oil chamber 5 side of one of the through holes 18, and a non-return valve 22 is pressed against the seat surface 21. A minute orifice 24 is provided by the groove. Other through hole 1
A leaf valve 26 is in contact with the seat surface 25 on the tank chamber 20 side of 9. 27 is a packing provided on the outer periphery of the piston 2.

In the conventional damping force generating device having the above configuration, the piston 2 is
When the oil moves at low speed in the direction of the upper oil chamber 4, the hydraulic oil in the upper oil chamber 4 passes through the minute orifice 12 due to the pressure difference between the upper oil chamber 4 and the lower oil chamber 5, passes through the through hole 6, and enters the lower oil chamber. 5 to generate a damping force in the low speed range. Further, when the movement speed of the piston 2 is medium, the hydraulic oil in the upper oil chamber 4 passes through the through hole 7, and the leaf valve 14 formed by bending the leaf valve 14 and the seat surface 13 are connected to each other. The damping force in the medium speed range is generated by flowing into the lower oil chamber 5 through the gap between The damping force is controlled.

On the other hand, in the stroke in which the shock absorber is compressed, when the movement of the piston 2 is slow, the hydraulic oil in the lower oil chamber 5 passes through the minute orifice 24 provided in the seat surface 21, thereby reducing the damping force in the low speed range. occurs, and when the movement of the piston 2 is at medium speed, the hydraulic oil in the lower oil chamber 5 passes through the through hole 19, pushes open the leaf valve 26, and flows into the tank chamber 20, thereby increasing the damping force in the medium speed range. Furthermore, when the piston 2 is at high speed, the through hole 19 is designed to generate a damping force in the high speed range.

In addition, in the extension stroke of the shock absorber, the non-return valve 22 of the base valve 17 is pushed open from the tank chamber 20 and the hydraulic oil is sucked up into the oil chamber 5, and in the compression stroke, the hydraulic oil in the oil chamber 5 is sucked up into the non-return valve 22 of the base valve 17. 9 is pushed open to supply oil to the oil chamber 4.

However, in the conventional device described above, the low speed range is controlled by minute orifices 12 and 24 formed by stamping in either the extension stroke or the compression stroke, so There is a large variation in the damping force, and since the hydraulic oil flows through a narrow passage, a swishing sound is generated due to the oil flow.Furthermore, since the passage is minute, the damping force becomes large due to the influence of the viscosity of the oil at low to high temperatures. There are drawbacks such as fluctuation, etc., and these drawbacks do not essentially change even if the orifice is replaced with a cutout valve made by cutting out a part of a thin plate. Furthermore, in the conventional device, the leaf valves 14 and 26 each use several overlapping thin plates, so the bending rigidity is large, which causes problems in damping control in the medium speed range.

In order to solve the above-mentioned drawbacks, recently, a structure as shown in FIGS. 2 and 3 has been proposed.

The example shown in FIG. 2 has through holes 6 and 7 on the outside and inside of the piston 2, similar to the device shown in FIG. is pressed by a spring 11, a seat surface 28 is formed inside the lower end (oil chamber 5 side) of the through hole 6, and a seat surface 29 lower than the seat surface 28 is formed outside the lower end of the through hole 7. ,
A sub-leaf valve 30 made of a thin plate with a small diameter is brought into contact with the inner seat surface 29 having a smaller diameter, and a spacer 31 is provided between the outer seat surface 28 and the sub-leaf valve 30. The main leaf valve 32 is provided with an oblique bypass passage hole 33 which is brought into contact with the sandwiched main leaf valve 32 and whose one end opens into the passage hole 6 and the other end opens between the seat surfaces 28 and 29. is the spring 3 interposed between the flange portion 35 of the spring seat 34
6 and a spring seat 37.

The example shown in FIG. 3 is a modification of FIG. 2, in which a bypass hole 33a is provided in the piston 2 in parallel to the holes 6 and 7 instead of the oblique bypass hole 33.

In any of the above methods, the damping force when the piston 2 moves at low speed during the extension stroke of the piston rod 3 is
The hydraulic oil in the upper oil chamber 4 passes through the through hole 7 and pushes open the sub-leaf valve 30 to open the bypass through hole 33 or 3.
3a, it is generated by flowing through the through hole 6. Therefore, although the damping force in the low speed range is generally a small value, because the diameter of the inner seat surface 29 is small, even if the subleaf valve 30 is made of a thin plate, the rigidity is relatively high. The leaf valve 30 is difficult to open in some cases, making it difficult to respond to small damping forces.The damping force in the low speed range is controlled by changing the plate thickness of the sub-leaf valve 30 and the outer diameter of the spacer 31. The control range is narrow due to the small space, and there is a lot of room for improvement in terms of versatility.The slanted through hole 33 in Fig. 2 is difficult to machine.
The seat surface is often scratched, and a special jig is required.If parallel through holes 33a are provided as shown in Fig. 3, there is little space in the radial direction, so the dimensions of the through holes 33a are Possible problems include that there are restrictions on the method shown in Fig. 2 and Fig. 3, and that even if either of Fig. 2 or Fig. 3 is implemented, the implementation cost will be relatively high because the piston 2 is a special component.

The object of the present invention is to make it possible to control the damping force in the low speed range without providing the piston with the inclined or parallel through holes in the recently proposed devices described above.

In order to achieve the above object, the structure of the present invention is to provide a partition member inside the cylinder, and to make the partition member communicate with two liquid chambers, such as an oil chamber and an oil chamber, or an oil chamber and a tank chamber, a dedicated expansion side or pressure side. A through hole is provided, and a seat surface is formed on the outlet side of this dedicated through hole, and the sub-leaf valve is brought into contact with the seat surface so as to close the through hole, and furthermore, a seat surface is formed on the outlet side of the dedicated through hole, and the sub-leaf valve is brought into contact with the seat surface so as to close the through hole. A washer with a small outer diameter is interposed between the washer and a main leaf valve facing the sub-leaf valve is installed with a gap equal to the thickness of the washer on the back side of the washer, so that the piston speed remains at a predetermined value in the low speed range. For the first time, the hydraulic fluid from the other fluid chamber passes through the through hole and flows into one fluid chamber while bending and opening only the sub-leaf valve using the washer as a support point, and furthermore, in the medium speed range, the hydraulic fluid passes through the through hole from the other fluid chamber and flows into one fluid chamber. It is characterized by the fact that the leaf valve overlaps with the leaf valve and opens while being bent.

Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 4 shows an embodiment of the present invention.

As in the case of Fig. 1, the piston 2, which is a partition member that divides the inside of the cylinder 1 into an upper oil chamber 4 and a lower oil chamber 5, has a compression side passage hole 6 and a compression side passage hole 7 on the outside and inside, respectively. A non-return valve 9 is brought into contact with a seat surface 8 formed at the upper end of the outlet side of the through hole 6. On the other hand, the base valve body 17, which is a partition wall member, also has through holes 18 exclusively for the expansion side on the outside and inside.
A through hole 19 exclusively for the compression side is provided to communicate the lower oil chamber 5 with the tank chamber 20, and a non-return valve 22 is brought into contact with a seat surface 21 formed at the upper end of the outlet side of the through hole 18 on the expansion side. and is pressed by a spring 23.

A sub-leaf valve 3 is mounted on one seat surface 13 formed at the lower end of the outlet side of the through hole 7 of the piston 2.
The outer end of the leaf valve 8 is brought into contact with the through hole 7 so as to close it while the piston speed does not reach a predetermined value, and a main leaf valve 39 made of laminated thin steel plates is installed on the lower side of the sub-leaf valve 38. A special washer 40 with a small outer diameter is interposed between both the sub-leaf valves 38 and the main leaf valve 39, so that the thickness of the washer 40 is reduced between the sub-leaf valve 38 and the main leaf valve 39. A small gap is provided. The main leaf valve 39 is fastened to the piston rod 3 by a piston nut 16 via a collar 15.

On the other hand, on the base valve side, one seat surface 25 formed at the lower end of the outlet side of the through hole 19 of the base valve body 17 also has a sub-leaf valve 41 made of one thin steel plate as in the case of the piston 2. and a main leaf valve 42 made of laminated thin steel plates, and a special washer 43 having a small outer diameter is arranged. The support points of the sub-leaf valves 38, 41 are controlled by the outer diameters of the special washers 40, 43, and when the piston 2 moves at low speed, the sub-leaf valves 38, 41 are deflected by the gap between them and the main leaf valves 39, 42. By flowing a small amount of hydraulic oil, damping force in the low speed range is generated.

Note that in the figure, the same reference numerals as in FIG. 1 indicate the same parts and have the same functions.

With the above configuration, when the piston 2 moves at low speed during the extension stroke of the piston rod 3, the hydraulic oil in the upper oil chamber 4 passes through the through hole 7, pushes open the sub-leaf valve 38, and flows into the lower oil chamber 5. The flow generates damping force in the low speed range. At this time, the bending rigidity of the sub-leaf valve 38 can be controlled by its own thickness and the size of the outer diameter of the special washer 40, and the maximum opening amount (lift amount) of the sub-leaf valve 38 can be controlled by the special washer 40.
It can be easily changed depending on the thickness.

Next, as the movement of piston 2 becomes faster,
Since the hydraulic oil in the upper oil chamber 4 increases the pressure and enters the through hole 7, the sub-leaf valve 38 and the main leaf valve 39 overlap and bend, and a gap is formed between the sub-leaf valve 38 and the main leaf valve 39 and the seat surface 13. Damping force in the medium speed range is generated by squeezing and flowing the hydraulic oil. Therefore, the damping force in the medium speed range is determined by the combined bending rigidity of the sub-leaf valve 38 and the main leaf valve 39, and the main leaf valve 39 itself can be freely controlled depending on the amount of laminated thin steel plates. You can choose the stiffness.

The damping force in the high-speed range is determined by the through hole 7 as in the conventional case.
is determined by the size of

When the piston rod 3 is in the compression stroke, the damping force in the low speed range and the damping force in the medium speed range are the same as the functions of the sub leaf valve 38 and the main leaf valve 39 during the extension stroke of the piston rod 3. The leaf valve 42 functions to generate it.

5 to 7 show another embodiment of the present invention, and FIG. 5 shows the case where the present invention is applied to an M-type piston, in which one seat surface 44 of the piston 2
The leaf valve that is pressed by the spring 36 and spring seat 37 is called the sub-leaf valve 38.
and a main leaf valve 39, and a special washer 40 is sandwiched between them, so that the damping force in the low speed range is generated by opening only the subleaf valve 38, as in the case of the previous embodiment, and the damping force in the middle speed range is generated by the main leaf valve 39. This occurs when the valve 39 pushes the spring seat 37 and the spring 36 to open.

Figure 6 shows the application of the present invention to a piston 2 having one seat surface on both sides.
Sub-leaf valve 38 on the rod side and head side.
and the main leaf valve 39 are arranged with the special washer 40 sandwiched between them, and when the piston rod 3 is in the extension stroke, the sub leaf valve 3 on the head side
When the piston rod 3 is in the compression stroke, the sub-leaf valve 38 and the main leaf valve 39 on the rod side are operated.

FIG. 7 shows yet another application example. In each of the above embodiments, the sub-leaf valve and the main leaf valve had a laminated valve structure of the type in which the inner circumference was fixed, but the outer circumference fixed type was used. It can be similarly applied to laminated valves. Figure 7 shows an example of the base valve body 17.
In this case, a special washer 43 is interposed between the outer peripheral surface of the sub-leaf valve 41 which is brought into contact with one seat surface 25 and the outer peripheral part of the main leaf valve 42 made of laminated thin steel plates, and the presser foot 4 is
5 so that they are clamped. The damping force in the low-speed range and the damping force in the middle-speed range are generated by bending of the inner circumferences of the sub-leaf valve 41 and the main leaf valve 42, which are the same as in the embodiment shown in FIG. Although FIG. 7 shows a case in which it is applied to the base valve side, it can be similarly applied to the piston 2 side.

Note that if the low-speed damping force is high, the sub-leaf valves may also be laminated.

As described above, the shock absorber damping force generating device of the present invention can produce the following excellent effects.

Low-speed damping force is generated when only the sub-leaf valve opens, and medium-speed damping force is generated when the sub-leaf valve and main leaf valve open while overlapping.

The low-speed damping force can be freely set from a low value to a high value by changing the outer diameter of the washer.

Since there is only one seat surface, the structure is simple, and since there is only one seat surface, there is a large space for arranging the sub-leaf valve, so the rigidity of the sub-leaf valve can be freely selected.

When the main leaf valve is constructed from laminated thin steel plates, the rigidity can be freely selected.

Since the damping force in the low speed range can be controlled by the bending rigidity of the sub-leaf valve, the damping force is less affected by the viscosity of the hydraulic oil, compared to the conventional orifice type, at low to high hydraulic oil temperatures. The damping force fluctuations in the low temperature range and high temperature range with respect to the damping force in the normal temperature range are significantly reduced.

Since the oil flow that passes through the seat surface and the sub-leaf valve flows out from the entire circumference, the jet velocity of the hydraulic oil is small and there is almost no swishing noise that accompanies the oil flow.

The maximum opening amount (lift amount) of the sub-leaf valve in the low-speed range can be easily changed by changing the thickness of the washer, and in the medium-speed range, the damping force is determined by the combined rigidity of the sub-leaf valve and main leaf valve when they overlap. .

The damping force in the medium speed range is generated by the overlapping and bending of the sub-leaf valve and main leaf valve, so the sub-leaf valve has the same function as a structure with multiple main leaf valves, and this makes it possible to reduce the number of main leaf valves. There is no need to increase the number of parts, the number of parts can be reduced, and the weight can also be reduced.

There is no stamped orifice on the seat surface, and the damping force in the low-speed range can be controlled only by the rigidity of the sub-leaf valve, so there is little variation in the damping force, and this effect can also significantly improve damping force fluctuations in the high-speed range. .

[Brief explanation of the drawing]

Figure 1 is a half-sectional view of a conventional damping force generator for a shock absorber, Figures 2 and 3 are half-sectional views of a damping force generator for a shock absorber that has recently been considered, and Figure 4 is a half-sectional view of a damping force generator of the present invention. A half-sectional view showing an embodiment of a shock absorber damping force generating device,
5 to 7 are partial half-sectional views showing other embodiments of the present invention. 1... Cylinder, 2... Piston serving as a partition wall member, 3... Piston rod, 4, 5... Oil chamber,
6, 7...Through hole, 9...Non-return valve, 1
7...Base valve body serving as a partition wall member, 18,
19...Through hole, 20...Tank chamber, 22...Non-return valve, 38, 41...Sub-leaf valve, 39,42...Main leaf valve, 40,
34...Watsiya.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A partition member is provided in the cylinder, and the partition member has a dedicated passage on the expansion side or pressure side that allows two liquid chambers, such as an oil chamber and an oil chamber, or an oil chamber and a tank chamber, to communicate with each other. At the same time, a seat surface is formed on the outlet side of this dedicated through hole, and the sub-leaf valve is brought into contact with the seat surface so as to close the through hole, and a small A washer of the outer diameter is interposed, and a main leaf valve facing the sub-leaf valve is arranged with a gap equal to the thickness of the washer on the back side of the washer, and the piston speed reaches a predetermined value in the low speed range. For the first time, the hydraulic fluid from the other fluid chamber passes through the through hole and flows to one fluid chamber by bending and opening only the sub-leaf valve using the washer as a support point, and then in the medium speed range, the hydraulic fluid flows through the sub-leaf valve and the main leaf valve. A damping force generating device for a shock absorber, characterized in that the damping force generating device of a shock absorber is configured such that the two parts overlap each other and are bent to open. (2) A damping force generating device for a shock absorber as set forth in claim 1 of the utility model registration claim, in which through holes are provided in the piston and the base valve body, which are partition wall members. (3) The damping force generating device for a shock absorber according to claim 1, wherein the inner peripheries of the sub-leaf valve and the main leaf valve are fixed, and the supporting diameter of the sub-leaf valve is the outer diameter of the washer. (4) The damping force generating device for a shock absorber according to claim 1, wherein the outer peripheries of the sub-leaf valve and the main leaf valve are fixed, and the support diameter of the sub-leaf valve is the inner diameter of the washer. (5) The damping force generating device for a shock absorber according to claim 1, wherein a washer is sandwiched between a sub-leaf valve and a main leaf valve by a piston having one seat surface on both sides.