JP2008281113A - Valve structure of shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve structure of a shock absorber easy in detecting lamination failure, even if damping force is proportionally changed in a low speed area to a piston speed. <P>SOLUTION: This valve structure of the shock absorber has: a valve disc 1 having ports 2a and 2b and annular valve seats 1a and 1b arranged on the outer periphery of the ports 2a and 2b; and leaf valves 10a and 10b laminated on the valve disc 1, seated on the annular valve seats 1a and 1b and opening-closing the ports 2a and 2b, and also has support members 11 and 13 laminated on the leaf valves 10a and 10b via sub-leaf valves 12a and 12b and supporting a back face of the leaf valves 10a and 10 by partially abutting on the back face. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improved valve structure of a shock absorber.

  Conventionally, in this kind of shock absorber valve structure, for example, it is embodied in a piston portion or the like of a shock absorber for a vehicle, and a piston that separates two pressure chambers in the shock absorber and the piston is provided. An annular leaf valve seated on an annular valve seat disposed on the outer periphery of the port is known, and the leaf valve is used to open and close the port.

  When the piston speed is low in the above-described shock absorber valve structure that opens and closes the port by bending the outer peripheral side of the leaf valve, the working liquid is provided in the notch provided in the annular valve seat or the outer periphery of the leaf valve. It passes through the orifice formed by the notch and moves from the compressed pressure chamber to the expanded pressure chamber.

  Therefore, in such a valve structure of the shock absorber, when the piston speed is low, a damping characteristic (a change in damping force with respect to the piston speed) that is a square characteristic peculiar to the orifice is exhibited, and the piston speed is in a low speed region. The damping force change is large with respect to the piston speed change, and when the piston speed goes out of the low speed range and becomes medium speed, the leaf valve is separated from the annular valve seat, so the damping characteristic in the medium speed range is the damping characteristic in the low speed range. In contrast, the attenuation characteristics change abruptly.

  Therefore, in order to change the damping force linearly with respect to the piston speed in the low speed region, the leaf valve deflection is partially restricted between the leaf valve seated on the valve seat and the sub leaf valve stacked on the leaf valve. There has been proposed a shock absorber valve structure having a cross-shaped seat interposed therebetween (see, for example, Patent Document 1).

In this valve structure of the shock absorber, the seat has a cross shape, so that the leaf valve partially contacts the back surface of the leaf valve and the leaf valve is not in contact with the seat when the piston speed is low. Since only the flexure opens the port, the damping force can be changed in proportion to the piston speed.
Japanese Patent Laid-Open No. 9-42357 (FIG. 2)

  However, in the proposed valve structure as described above, the damping force can be changed proportionally with respect to the piston speed. There is.

  In the proposed valve structure, in order to partially support the leaf valve, a seat is interposed between the leaf valve and the sub leaf valve, and the leaf valve, the sub leaf valve and the seat are very thin. Therefore, when assembling and after assembling the piston part in which the valve structure is embodied, it is not easy to check whether seats are forgotten, that is, whether stacking failure has occurred. It takes a lot of work. Further, when a plurality of types of sheets having different shapes are prepared and the piston portion is assembled in order to tighten the damping characteristics if possible, the work time is increased and the burden is increased.

  Therefore, the present invention was devised to improve the above-mentioned problems, and the object of the present invention is to change the damping force in the low speed region in proportion to the piston speed. Another object of the present invention is to provide a valve structure of a shock absorber that can easily find a stacking fault.

  In order to solve the above-described object, the problem-solving means in the present invention includes a valve disk including a port and an annular valve seat disposed on the outer periphery of the port, and is stacked on the valve disk and seated on the annular valve seat. In the valve structure of the shock absorber provided with a leaf valve that opens and closes the port, a support member is provided which is stacked on the leaf valve via the sub leaf valve and is supported by partially contacting the back surface of the leaf valve. And

  According to the valve structure of the shock absorber of the present invention, the damping force in the low speed region can be changed in proportion to the piston speed, and the support member is interposed between the leaf valve and the sub leaf valve. Rather than being laminated so as to cover these leaf valves and sub-leaf valves, the visibility from the outside is good, and it is easy to check the presence or absence of the support member during and after the assembly process, It is possible to quickly find out that a stacking fault has occurred, and furthermore, since the presence or absence of a support member can be easily confirmed even during assembly processing, the occurrence of stacking fault itself can be suppressed.

  In addition, since the occurrence of defective stacking can be suppressed, the product yield is improved, the time required for checking the presence / absence of the support member is shortened, and the work load is drastically reduced.

The valve structure of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a part of a piston portion of a shock absorber in which a valve structure according to an embodiment is embodied. FIG. 2 is a perspective view of a support member in the valve structure of the shock absorber according to the embodiment. FIG. 3 is a perspective view of the support member in the valve structure of the shock absorber according to one modification of the embodiment. FIG. 4 is a diagram illustrating a damping characteristic in the shock absorber in which the valve structure of the shock absorber according to the embodiment is embodied.

  As shown in FIG. 1, the valve structure of the shock absorber in one embodiment is embodied in both the expansion side and pressure side damping valves of the piston portion of the shock absorber. An annular valve seat 1a, 1b disposed on the outer periphery of each of the ports 2a, 2b and the one side port 2a and the other side port 2b that separates the chamber 42 and communicates the one chamber 41 with the other chamber 42. The provided piston 1 as a valve disk, the leaf valve 10a on one side stacked on one side of the piston 1 to open and close the port 2a on one side, and the port 2b on the other side stacked on the side of the other chamber of the piston 1 A leaf valve 10b on the other side that opens and closes the leaf valve, and a leaf valve 10a that is stacked on the one side through a sub leaf valve 12a and supports the back surface of the leaf valve 10a by partially contacting the leaf valve 10a. And a support member 13 on the other side which is stacked on the leaf valve 10b on the other side via the sub leaf valve 12b and supports the back surface of the leaf valve 10b by partially contacting the leaf valve 10b. Yes.

  On the other hand, a shock absorber in which the valve structure is embodied is well known and will not be described in detail, but specifically, for example, a cylinder 40 and a head member (not shown) that seals the upper end of the cylinder 40. ), A piston rod 5 slidably passing through a head member (not shown), a piston 1 inserted through the tip 5a of the piston rod 5 and fixed to the tip 5a, and a piston 1 in the cylinder 40 The one chamber 41 on the upper side in FIG. 1 and the other chamber 42 on the lower side in FIG. 1, a sealing member (not shown) that seals the lower end of the cylinder 40, and the volume of the piston rod 5 that protrudes and retracts from the cylinder 40. The cylinder 40 is provided with a reservoir or an air chamber (not shown) that compensates for the minute volume change in the cylinder, and the cylinder 40 is filled with a fluid, specifically, hydraulic oil.

  In the valve structure, when the piston 1 moves up and down in FIG. 1 with respect to the cylinder 40, the hydraulic oil exchanges between the one chamber 41 and the other chamber 42 via the ports 2a and 2b. In addition, the leaf valves 10a and 10b corresponding to the flow of the hydraulic oil are given resistance to cause a predetermined pressure loss, thereby functioning as a damping force generating element for generating a predetermined damping force in the shock absorber.

  Hereinafter, the valve structure will be described in detail. The piston 1 serving as a valve disc is formed in an annular shape and operates in reverse to the port 2a on one side that allows hydraulic oil to pass from the other chamber 42 to the one chamber 41. The other side port 2b that allows oil to pass from the one chamber 41 to the other chamber 42, the windows 3a and 3b respectively connected to the outlet ends of the ports 2a and 2b, and the outlet ends of the ports 2a and 2b Annular valve seats 1a and 1b formed on the outer peripheral sides of the windows 3a and 3b are provided.

  Further, the port 2a is considered not to be blocked by the other leaf valve 10b that is opened from the outer peripheral side of the annular valve seat 1b and stacked on the other chamber side surface of the piston 1, and the other port 2b is similarly It opens from the outer peripheral side from the annular valve seat 1a.

  As described above, the tip 5a of the piston rod 5 of the shock absorber is inserted into the inner peripheral side of the piston 1, and the tip 5a of the piston rod 5 is protruded downward in FIG.

  Further, the outer diameter of the tip 5a of the piston rod 5 is set to be smaller than the outer diameter on the upper side in FIG. 1 from the tip 5a, and a step portion 5b is formed at a portion where the outer diameters of the upper side and the tip 5a are different. Further, a screw groove 5c is formed on the outer periphery of the lower end of the tip 5a in FIG.

  Further, the leaf valves 10 a and 10 b stacked on the top and bottom of the piston 1 in FIG. 1 are each formed in an annular shape, and the leaf valve 10 a on one side is fixed to the tip 5 a of the piston rod 5 on the inner peripheral side. Along with the annular valve seat 1a formed on the piston 1, the outlet end of the port 2a on one side is closed, and the leaf valve 10b on the other side is fixed to the tip 5a of the piston rod 5 and the piston 1 is in contact with the annular valve seat 1b formed at 1 and closes the outlet end of the other port 2b.

  Therefore, the leaf valves 10a and 10b can open the ports 2a and 2b when the inner peripheral side is a fixed end and the outer peripheral side is bent.

  Further, a sub-leaf valve 12a having a smaller diameter than the leaf valve 10a on one side is laminated on the back surface opposite to the piston 1 side of the leaf valve 10a on one side, and the piston 1 of the leaf valve 10b on the other side is laminated. A sub-leaf valve 12b having a smaller diameter than the leaf valve 10b on the other side is laminated on the back surface, which is the side opposite to the side. In this embodiment, the sub-leaf valves 12a and 12b each have two annular plates. It is configured by stacking.

  In this embodiment, the leaf valves 10a and 10b are configured by a single annular plate. However, the leaf valves 10a and 10b may be a stacked leaf valve configured by stacking a plurality of annular plates. The number of sheets can be arbitrarily determined according to the damping characteristics realized by the present valve structure, and the number of annular plates can be arbitrarily set by the damping characteristics realized by the present valve structure even in the sub-leaf valves 12a and 12b.

  Subsequently, the support member 11, the sub leaf valve 14a, and the spacer 15 on the one side are sequentially stacked on the upper side of the sub leaf valve 12a on the one side in FIG. 1, and the sub leaf valve 12b on the other side in FIG. On the lower side, the other side support member 13, the sub leaf valve 14b, and the spacer 16 are laminated in order, and these members are assembled to the tip 5a of the piston rod 5 together with the piston 1, and the screw groove provided in the tip 5a. The piston nut 17 and the stepped portion 5b of the piston rod 5 are screwed to 5c and are fixed to the piston rod 5.

  That is, in this valve structure, the configuration of the leaf valve 10a, the sub leaf valve 12a, the support member 11, the sub leaf valve 14a and the spacer 15 disposed on the upper side of the piston 1 and the lower side of the piston 1 are provided. The configurations of the leaf valve 10b, the sub leaf valve 12b, the support member 13, the sub leaf valve 14b, and the spacer 16 that are disposed are symmetrical with respect to the piston 1 as an upside down.

  As shown in FIG. 2, the support member 11 on one side is an annular plate 11a stacked on the leaf valve 10a via the sub leaf valve 12a, and the leaf valve on the one side is suspended from the outer periphery of the plate 11a. And four support portions 11b that protrude toward the 10a side and come into contact with the back surface of the leaf valve 10a.

  In the case of this embodiment, the support portions 11b are provided at equal intervals on the outer periphery of the plate 11a, and abut on the same circumference on the back surface of the leaf valve 10a with equal intervals. And the contact part of the leaf valve 10a of the support part 11b is arrange | positioned in the outer peripheral side rather than the inner edge of the annular valve seat 1a.

  Similarly to the support member 11 described above, the other side support member 13 has an annular plate 13a stacked on the leaf valve 10b via the sub leaf valve 12b, and the other side leaf 13 is suspended from the outer periphery of the plate 13a. Four support portions 13b that protrude toward the valve 10b and abut against the back surface of the leaf valve 10b are provided.

  In this embodiment, the support portions 13b are provided at equal intervals on the outer periphery of the plate 13a, and abut on the same circumference on the back surface of the leaf valve 10b with equal intervals. And the contact part of the leaf valve 10b of the support part 13b is arrange | positioned in the outer peripheral side rather than the inner edge of the annular valve seat 1b.

  In order to manufacture the support members 11 and 13, for example, the support portions 11b and 13b may be bonded or welded to the side surfaces of the leaf valves 10a and 10b on the outer periphery of the plates 11a and 13a, and as shown in FIG. The ring R having a plurality of support portions 11b and 13b may be bonded or welded to the side surfaces of the leaf valves 10a and 10b of the plates 11a and 13a in advance.

  The support members 11 and 13 are partially abutted and supported on the back surfaces of the leaf valves 10a and 10b, respectively, and the bending of the leaf valves 10a and 10b in the support portions is suppressed, so that the piston speed is low. In this case, the leaf valves 10a and 10b both start to bend from a portion not supported by the support members 11 and 13, and the amount of bending gradually increases as the piston speed increases, so that the piston speed is in the middle speed range. When reaching, the parts supported by the support members 11 and 13 are also bent, and the entire outer circumferences of the leaf valves 10a and 10b are separated from the annular valve seats 1a and 1b.

  Next, the operation of the valve structure configured as described above will be described. First, when the piston 1 moves downward in FIG. 1 with respect to the cylinder 40, the pressure in the other chamber 42 increases, and the hydraulic oil in the other chamber 42 passes through the port 2a on one side and enters the one chamber 41. Try to move.

  And when the piston speed used as the expansion-contraction speed | velocity | rate of a shock absorber exists in a low speed area | region, hydraulic fluid is not supported by the support member 11 among the outer periphery of the leaf valve 10a of the one side seated on the above-mentioned annular valve seat 1a. When the portion is bent and moved to the one chamber 41 side, and then the piston speed increases and reaches the middle speed region, the hydraulic oil also deflects the plate 11a of the support member 11 together with the leaf valve 10a on one side. The leaf valve 10a is bent at the entire outer periphery to form a gap between the leaf valve 10a on one side and the annular valve seat 1a, and the hydraulic oil passes through this gap.

  As described above, the size of the gap formed between the leaf valve 10a and the annular valve seat 1a is gradually increased as the piston speed increases until the entire circumference of the leaf valve 10a is separated from the annular valve seat 1a. The generated damping force changes in proportion to the piston speed, and the damping characteristic on the pressure side generated by the shock absorber embodying this valve structure is as shown in FIG. Compared to the provided valve structure, the damping characteristic does not change abruptly at the boundary between the low speed region and the medium speed region.

  On the contrary, when the piston 1 moves upward in FIG. 1 with respect to the cylinder 40, the configuration of the valve structure arranged on the lower side of the piston 1 is mutually different from the configuration arranged on the upper side of the piston 1. Since the structure is upside down, the operation similar to that described above is exhibited, so the attenuation characteristics on the extension side are as shown in FIG.

  Therefore, in the shock absorber valve structure of the present embodiment, the damping force in the low speed region can be changed in proportion to the piston speed.

  In the case of this valve structure, the support members 11 and 13 that partially support the back surfaces of the leaf valves 10a and 10b are not interposed between the leaf valves 10a and 10b and the sub leaf valves 12a and 12b. However, the leaf valves 10a and 10b and the sub leaf valves 12a and 12b are laminated so as to cover the leaf valves 10a and 10b. That is, the supporting members 11 and 13 partially support the back surfaces of the leaf valves 10a and 10b while securing the visibility from the outside, and partially increase the apparent bending rigidity of the leaf valves 10a and 10b. Can do it.

  Therefore, it is easy to confirm the presence or absence of the support members 11 and 13 during and after the assembly process of the valve embodied in the valve structure, and it is possible to quickly find out that a stacking failure has occurred. Since the presence or absence of the support members 11 and 13 can be easily confirmed even during processing, the occurrence of poor stacking itself can be suppressed. And since generation | occurrence | production of a lamination | stacking defect can be suppressed, a product yield improves.

  Furthermore, since it is easy to confirm the presence / absence of the support members 11 and 13, the time required for the confirmation work is shortened, and the work burden is drastically reduced.

  The number of support portions 11b and 13b installed in the support members 11 and 13 can be arbitrarily set according to the damping characteristic realized by this valve structure, and each interval between the support portions 11b and 13b in the support members 11 and 13 can be set. In addition, depending on the damping characteristics, it is set to be not equal intervals but unequal intervals, and the flexural rigidity of portions other than the support portion between the support portions 11b and 13b of the leaf valves 10a and 10b is different. You may make it show.

  Further, in the above description, the valve structure of the present invention has been described using an example embodied in the damping valve on both sides of the pressure expansion of the piston portion of the shock absorber, but only the expansion side or only the pressure side is described. It can be embodied in a damping valve, and can also be embodied in a base valve portion, and can be applied to a valve of a shock absorber that functions as a damping force generating element that generates a damping force. Of course. That is, when the valve structure is embodied in the base valve portion, one chamber may be one of the piston side chamber or the reservoir chamber, and the other chamber may be the other of the piston side chamber or the reservoir chamber.

 This is the end of the description of the embodiment of the valve structure of the shock absorber, but the scope of the present invention is not limited to the details shown or described.

It is a longitudinal cross-sectional view in a part of piston part of the shock absorber in which the valve structure in one embodiment was embodied. It is a perspective view of the supporting member in the valve structure of the shock absorber of one embodiment. It is a perspective view of the supporting member in the valve structure of the buffer of one modification of one embodiment. It is a figure which shows the damping characteristic in the buffer which embodied the valve | bulb structure of the buffer of one Embodiment.

Explanation of symbols

1 Valve disc piston 1a, 1b Annular valve seat 2a One side port 2b Other side port 3a, 3b Window 5 Piston rod 5a Piston rod tip 5b Piston rod step 5c Piston rod screw groove 10a One side leaf Valve 10b Leaf valve 11 on the other side Support members 11a and 13a on the one side Plates 11b and 13b on the support member Support portions 12a, 12b, 14a and 14b on the support member Sub leaf valve 13 Support members 15 and 16 on the other side Spacer 17 Piston nut 40 Cylinder 41 One chamber 42 Other chamber R Ring

Claims (3)

In a valve structure of a shock absorber comprising a valve disk having a port and an annular valve seat disposed on the outer periphery of the port, and a leaf valve stacked on the valve disk and seated on the annular valve seat to open and close the port A shock absorber valve structure comprising a support member that is stacked on a leaf valve via a sub-leaf valve and that supports a part of the leaf valve in contact with the back of the leaf valve. The support member includes a plate having elasticity, and at least one support portion that protrudes from the outer periphery of the plate toward the leaf valve and contacts the back surface of the leaf valve. The shock absorber valve structure according to claim 2, wherein the contact portion of the support portion with the leaf valve is set to be on the outer peripheral side from the inner edge of the annular valve seat.

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