KR930001688B1 - Valve mechanism of shock absorber - Google Patents

Abstract

No content.

Description

Valve structure of shock absorber

1 is a cross-sectional view of the lower part of the shock absorber to which the valve structure according to the present invention is applied.

2 is an enlarged cross-sectional view of the valve structure.

FIG. 3A is a bottom view of the separator, and FIG. 3B is a sectional view taken along the line III-III of FIG. 3A.

4A is a bottom view of the slit valve, and FIG. 4B is a sectional view taken along line IV-IV of FIG. 4A.

5 and 6 are cross-sectional views of the same type as in FIG. 2 illustrating the operation of the valve structure.

7 and 8 are graphs showing the relationship between the piston speed and the damping force.

FIG. 9A is a bottom view showing another example of a separator, and FIG. 9B is a sectional view taken along line VII-VII of FIG. 9A.

FIG. 10A is a bottom view showing another example of the slit valve, and FIG. 10B is a sectional view taken along line VII-VII of FIG. 10A.

11 is a graph showing the relationship between the piston speed and the damping force at the lowest speed.

12 is a cross-sectional view of a lower valve structure to which the valve structure according to the present invention is applied.

13 is a sectional view of a valve structure according to another embodiment.

FIG. 14A is a bottom view of the groove valve of FIG. 13, and FIG. 14B is a sectional view taken along line XIV-XIV in FIG. 14A.

FIG. 15 is a sectional view of the same type as FIG. 13 showing the action of the valve.

16 is a sectional view of a valve structure according to another embodiment.

FIG. 17A is a bottom view of the groove valve of FIG. 16, and FIG. 17B is a sectional view along the line XVII-XVII of FIG. 17A.

18 is a cross-sectional view of the same type as FIG. 16 showing the action of the valve.

19 is a sectional view of a valve structure according to another embodiment.

FIG. 20A is a plan view of the inner ring of FIG. 19, and FIG. 20B is a sectional view taken along the line XX-XX of FIG. 20A.

FIG. 21A is a plan view of the outer ring of FIG. 19, and FIG. 21B is a sectional view taken along the line XXI-XXI in FIG. 21A.

Sectional drawing similar to FIG. 19 explaining the valve of FIG.

23 is a cross-sectional view of a conventional valve structure.

* Explanation of symbols for main parts of the drawings

4: cylinder 5: piston rod

8: Piston 12, 31: Valve Guide

13: main valve 14, 33, 40, 50: sub-valve

15: valve seat 17, 36, 41, 51: separator

18, 37, 53: slit valve 19, 38, 44, 55: backup valve

30: lower valve 42, 52: shield valve

The present invention relates to a valve structure of a shock absorber for use in automobiles, motorcycles, and the like.

As a shock absorber used in automobiles, when the strouk speed of the piston is slow (for example, 0.3 m / s or less), the damping force is lowered to increase the ride comfort when riding a car, and the stroke speed of the piston is medium or high speed. In order to increase the damping force and to improve the stability of the eye, there is a need for a feature. For this reason, a valve structure called a jack-type is known as illustrated in FIG.

Referring to FIG. 23, the jack-type valve structure is fixed to the shaft 103 of the piston rod 101 inserted into the cylinder 100. 108, the valve seat 107, the valve valve 106 and the valve seat are provided, and when the piston speed (moving upward in the figure) is slow (e.g. 0.3 m / s or less), the valve valve 106 The hydraulic fluid in the oil chamber S ₁ is formed in the slit 105a and the piston 103 between the leg portions of the valve guide 104 as indicated by the arrow while the bending oil does not bend and the valve seat 107 is engaged. It flows into the oil chamber S ₂ through the oil hole 103a, and the damping force at this time is made to depend on the slit 105a.

In addition, when the piston speed becomes medium and high speed, the inner circumferential portion of the valve valve 106 is bent downward due to the increase in the internal pressure of the oil chamber S ₁ to open the flow path between the valve seat 107 and the low speed range. In addition to the oil passage in the oil passage, the hydraulic oil is introduced into the oil chamber S ₂ through the oil hole 107a formed in the valve sheet 107 and the oil passage opened between the plate valve 106 and the valve sheet 107.

And the damping force adjustment in the low speed range is performed by changing the magnitude | size of the slit 105a.

By the way, in recent years, the sliding friction in the sliding part of a shock absorber, for example, a piston outer periphery, a cylinder inner periphery, etc. becomes very small.

In the related art, the above-mentioned sliding friction is somewhat large, and this sliding friction is a resistance in the low speed range of the piston speed, and this has been shown to exhibit a proper riding comfort. This results in a lack of reducing power.

In order to solve this by the conventional valve structure, the area of the slit may be reduced. However, simply reducing the area of the slit does not improve the lack of damping force at the lowest piston speed (for example, 0.1 m / s or less). In addition, there is a problem that the damping force rapidly increases in the region of the piston speed higher than the minimum speed, and that the damping force at medium and high speeds does not flex smoothly.

The valve structure according to the present invention for solving the above problems has a low speed range when the piston speed is at a low speed, in addition to a main valve of the same type as the conventional type which opens the flow path when the piston speed enters the medium / high speed range. The subvalve which opens a flow path when the speed exceeds a predetermined speed in the inside is provided.

For example, when the piston slides at the lowest speed of 0.1 m / s or less and the internal pressure of the oil chamber on the compression side becomes more than a predetermined value, the flow path is opened by the sub-valve and generates a moderate damping force, and the piston speed Weighted. In the high speed range, a separate flow path is opened by the main valve, and excellent damping force is generated in the stability of the nailing.

EXAMPLE

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is a longitudinal cross-sectional view of the lower part of the shock absorber to which the valve structure according to the present invention is applied, and the lower end of the outer cylinder 1 of the shock absorber is closed with (2), and the inner cylinder ( The lower end of 4) is fixed, and the piston rod 5 is inserted into the inner cylinder 4 from the upper side, and the valve collar 7 is inserted into the small diameter side portion 6 of the lower portion of the piston rod 5. The piston 8 is fixed to the inner circumferential surface of the inner cylinder 4 by the nut 9 at the lower end of the shaft portion 6 using the valve collar 7 as a positioning member. the inner cylinder (4) in the upper loss (S ₁₎ and a lower loss (S ₂₎ to the compartment and the lower loss (S ₂₎ and the fuel chamber (油溜between the inner cylinder 4 and the outer cylinder (1) (Iii) S ₃ is communicated with the hole 3a formed in the lower body 3.

Moreover, the upper part of the said piston 8 has the valve mechanism 10 which applied the valve structure which concerns on this invention, and the lower valve mechanism 30 which applied the valve structure which concerns on this invention was applied to the upper part of the lower body 3. As shown in FIG. I install it.

As shown in the enlarged sectional view of FIG. 2, the valve mechanism 10 has a valve guide between the flange part 8a which protruded on the upper surface of the piston 8, and the support plate 11 which was attached to the end part of the piston rod 5. As shown in FIG. (12) is provided, and the main valve 13 and the sub valve 14 are disposed in the valve guide 12.

The main valve 13 is composed of a plurality of plate valves, the outer peripheral portion of the main valve 13 abuts inside the leg portion of the valve guide 12, and the inner circumference of the main valve 13 is the valve collar ( 7) A gap is formed between them with a larger diameter.

The upper surface of the inner circumference of the main valve 13 is attached to the lower surface of the inner circumference of the valve seat 15, and the valve seat 15 has a hole 15a formed therein, and is downward by the spring 16. It is installed elastically.

On the other hand, the sub-valve 14 is composed of a separator 17, a slit valve 18 and a backup valve 19, the separator 17 is a third cross-sectional view taken along the line III-III of Fig. 3a and 3a of the bottom view. As shown in the figure, the overall shape is substantially annular, and an inner diameter hole is provided with a protrusion 17a protruding inward, and the protrusion 17a is attached to the valve collar 7 and the upper outer periphery thereof. A protrusion 17b is formed at the bottom, and the bottom 17 of the main valve 13 is supported by the protrusion 17b, and a protrusion 17c is formed at the bottom of the bottom. 17d is formed, and the groove 17e is formed between this thick part 17d and the protrusion 17c.

The lower end of the thick portion 17d is located below the lower end of the protrusion 17c, and the inner peripheral part of the upper surface of the slit valve 18 is bonded to the lower end of the thick portion 17d.

The slit valve 18 forms a plurality of slits 18a at equal intervals on the outer periphery of the annular plate valve, as shown in Figs. 4A and 4B, which are sectional views of Figs. 4A and 4A, respectively. The backup and valve 19 superimposed on the lower surface of the slit valve 18 are constituted by plate valves.

The operation | movement with the valve mechanism 10 comprised as mentioned above is demonstrated based on FIG. 2, FIG. 5 thru | or FIG. 7 is a graph showing the relationship between the piston speed and the damping force from the low speed range to the high speed range.

FIG. 8 is an enlarged graph of the low speed range of FIG. 7 (indicated by dotted line A). In FIG. 8, the horizontal axis (piston speed) interval is larger than that of FIG. It is getting smaller than that.

In addition, in FIG. 7 and FIG. 8, the solid line has shown the damping force curve by the conventional valve, and the dotted line has shown the damping force curve by the valve of this invention.

First, immediately after the piston 8 starts sliding (moving upward in the drawing), the internal pressure of the oil chamber S ₁ does not bend the inner diameters of the slit valve 18 and the backup valve 19, as shown in FIG. There is no communication between the loss (S ₁ ) and the loss (S ₂ ).

Subsequently, when the speed of the piston 8 is slightly increased (0.1 m / s or less), the pressure in the groove valve 17e communicating through the oil chamber S ₁ and the slit 18a increases, as shown in FIG. Likewise, the inner diameters of the slit valve 18 and the backup valve 19 are bent downward, and the flow path 20 is opened therein, and the hydraulic oil in the oil chamber S _{2 is} formed in the flow path 20 and the piston 8. As it flows into the oil chamber S ₂ through 8b, the damping force arises suddenly as shown in FIG. 8, and the damping force also increases as the piston 8 increases its speed within the low speed range.

When the speed of the piston 8 reaches a predetermined speed exceeding 0.3 m / s, the inner diameter of the main valve 15 is lowered as shown in FIG. 6 by the hydraulic pressure acting on the upper surface of the main valve 13. Is bent, and the flow path 21 is opened between the valve seat 15 and the valve seat 15.

This point is called a blow off point, and is shown by arrow a in FIG.

When the flow passage 21 is opened in this way, the hydraulic oil in the oil chamber S ₁ flows into the oil chamber S ₂ through the other flow passage 21 in addition to the flow passage 20, and the damping force after the blow-off point is shown in FIG. 7. As will be the same as before.

9A and 9B, another embodiment of the separator 17 is shown. A plurality of recesses 17f are formed in the outer peripheral portion 17b of the lower surface of the separator 17 at equal intervals in the circumferential direction. By employing the separator 17, the slit valve 18 in FIG. 2 can be omitted. That is, the recess 17f functions as a substitute for the slit 18a of the slit valve 18. In such a case, the upper surface of the backup valve 19 directly contacts the lower surface of the separator 17.

10A and 10B show a modification of the slit valve 18. In the inner circumferential portion of the slit valve 18, a slit 18b having an area smaller than that of the slit 18a of the outer circumferential portion is additionally formed. By the installation of this slit 18b, the rear oil chamber S ₁ is always in communication with the lower oil chamber S ₂ . Therefore, the damping force characteristic at the time of the minimum speed extension of the piston 8 is slightly slower than that in the embodiment of FIG. 2, as indicated by the dashed line in FIG. By making the damping force generation characteristic at the time of the lowest speed extension of the piston 8 smooth, the riding comfort is further improved.

FIG. 12 is an enlarged view of the lower valve mechanism 30 of FIG.

The structure and function of the lower valve mechanism 30 is substantially the same as the valve mechanism 10. However, in contrast to the valve mechanism 10, the function of the lower valve mechanism 30 generates a damping force only during the compression stroke of the piston 8, while the damping force does not substantially occur during the expansion stroke of the piston 8. Do not.

The valve mechanism 30 is a valve in which a lower end portion outer periphery is fixedly sandwiched between an upper surface of the outer periphery portion of the lower body 3 and a lower end portion of the inner cylinder 4, and a plurality of slits are formed in the outer periphery portion. It has a guide 31. In the valve guide 31, the main valve 32 which opens at the time of the medium and high compression movement of the piston 8, and the sub valve 33 which opens at the minimum speed and low speed compression movement of the piston 8 are fitted. Each vane valve 32 has a plurality of annular plate valve members, and its outer circumferential portion abuts against the inner circumferential surface of the valve guide 31. The main valve 32 further includes a valve seat 35 provided in the valve guide 31 so as to slide on an inner circumferential surface of the valve guide 31. A spring 34 having a relatively small spring coefficient is inserted between the upper surface of the valve seat 35 and the valve guide 31. The sub valve 33 is a separator 35, a slit valve 37 and a backup valve 38 which are provided inside the leg of the valve guide 31 at the lower side of the main valve 33. It is composed above.

Grooves 36e are formed on the lower surface of the separator 36, and a plurality of slits 37a are formed on the outer periphery of the slit valve 37. The grooves 36e and the slits 37a are the same as the grooves 17e and the slits 18a shown in FIGS. 3A, 3B, 4A, and 4B. In the compression stroke and the expansion stroke of the piston 8, since the function of the valve mechanism 30 is obvious, the description thereof is omitted.

13 is a cross-sectional view of another embodiment in which the structure of the subvalve is different, and the subvalve 40 has an annular separator 41, a shutoff valve 42, a groove valve 43, and a backup valve 44. The groove valve 43 is sandwiched between the shielding valve 42 and the backup valve 44.

The groove valve 43 forms a plurality of slits 43a facing inward from the outer circumference, as shown in FIG. 14A, a bottom view of FIG. 14A and a cross-sectional view of the XIV-XIV line of FIG. 14A, and in this slit 43a. Grooves 43b to connect are formed in the radially inner side.

In addition, about the other member, since it is the same as the said Example, the same number is attached | subjected.

As described above, in the case where the piston speed is the lowest speed, the oil chamber S ₁ and the oil chamber S ₂ do not communicate as shown in FIG. 13, and when the piston speed becomes the low speed, the hydraulic oil introduced into the groove 43b is introduced. The inner circumferential portion of the backup valve 44 is bent downward as shown in FIG. 15 by the pressure, and the flow path 20 is opened therein, and at this point, it rapidly rises as shown in FIGS. 7 and 8. Damping force is generated.

When the piston speed becomes faster, the main valve 13 is bent downward to open another flow path (blow off point), and then exhibit the same damping force characteristics as in the prior art.

Further, the shielding valve 42 and the backup valve 44 are both constituted by plate valves, and when the rigidity of the shielding valve 42 is equal to or less than that of the backup valve 44, the shielding is performed at the minimum speed. It is also possible to open the flow path 20 between the valve 42 and the groove valve 43.

16 is a cross-sectional view showing another embodiment in which the structure of the subvalve is different, and the subvalve 50 includes an annular separator 51, a shielding valve 52, a slit valve 53, a groove valve 54, and a backup. The valve 55 is formed by inserting the groove valve 54 between the slit valve 53 and the backup valve 55, and the shielding valve 52 is overlapped on the upper surface of the slit valve 53.

FIG. 17A is a bottom view of another example of the groove valve 54, and FIG. 17B is a sectional view taken along the line XVII-XVII of FIG. 17A, and the groove valve 54 has a thin outer ring 54a and a thickness. The thick inner ring 54b is integrated at the connecting portion 54d, and an arcuate groove 54c is formed therein. The outer ring 54a and the inner ring 54b may have the same thickness.

As described above, when the piston speed is the minimum speed, as shown in FIG. 16, the oil chamber S ₁ and the oil chamber S ₂ are not in communication. When the piston speed reaches the minimum speed, the groove is grooved as shown in FIG. The flow path 20 opens and closes by the hydraulic pressure in 54c, and a damping force is generated rapidly as shown in FIG. 7 and FIG.

19 shows an example in which the groove valve of the subvalve 50 shown in FIG. 16 is divided into an inner ring 60 and an outer ring 61, and the inner ring 60 is shown in FIGS. 20a and 20b. As shown in the figure, the inner periphery has a ring shape, and the outer ring 61 forms a simple ring as shown in Figs. 21A and 21B, and its action is piston speed as shown in Fig. 22. When the lowest speed is the inner ring 30 is bent downward by hydraulic pressure to form a flow path.

In addition, although the slit valve and groove valve of various shapes were shown in the illustration, it is also possible to comprise the other Example which is not shown by combining these.

As described above, according to the present invention, a damping force is generated by the main valve and the subvalve, and a valve is formed. In particular, the subvalve opens the flow path at a predetermined value in the low speed range of the piston. Since the flow path is not opened at a speed that does not reach stationary, the damping force in the low speed range can be increased without changing the damping force characteristics in the medium and high speed ranges, and sliding friction is improved by various improvements, especially in recent shock absorbers. When applied to a decreasing number of shock absorbers, the lack of damping force in the low speed range is not caused.

Claims (5)

The main valve and the sub valve are arranged in the valve guide, and the sub valve forms a flow path when the piston moves at a low speed to generate a damping force, and the main valve forms a flow path when the piston moves at medium or high speed. Valve structure of the shock absorber, characterized in that for generating a damping force. The shock absorber valve structure according to claim 1, wherein a separator is inserted between the main valve and the subvalve. 3. The valve structure of a shock absorber according to any one of claims 1 to 3, wherein the subvalve overlaps a plate-shaped slit valve and a plate-shaped backup valve. The grooved valve according to any one of claims 1 to 3, wherein the sub-valve is fitted with a plate-shaped shielding valve and a plate-shaped back-up valve by forming a groove valve having a slit and a groove connected to the slit. Valve structure of shock absorber. The sub valve according to any one of claims 1 to 3, wherein the sub-valve is fitted on both sides of the groove valve by a plate-shaped slit valve and a plate-shaped backup valve, and on the side opposite to the surface in contact with the groove valve of the slit valve. The valve structure of the shock absorber, characterized in that the shielding valve is superimposed on.

Images