JP4331083B2 - Valve structure - Google Patents

Description

  The present invention relates to an improvement in a valve structure including a leaf valve.

  Conventionally, in a valve structure provided with this kind of leaf valve, for example, an annular groove which is embodied in a piston portion of a shock absorber and which is called a window communicating with each port is provided at an outlet end of a port provided in the piston portion. It is known to open and close a port by forming and opening and closing this window with a laminated leaf valve.

  The radial width dimension of the window is set larger than the diameter of the port, and the laminated leaf valve is laminated on the first leaf valve and the annular first leaf valve that abuts the outlet end of the window. An annular second leaf valve provided with three arc-shaped elongated holes provided at equal intervals in the circumferential direction, and a choke that communicates the elongated hole with the outer periphery, and laminated on the second leaf valve. And includes a third leaf valve having three arc-shaped elongated holes provided at equal intervals in the circumferential direction, and an annular fourth leaf valve stacked on the third leaf valve. When the piston speed when the shock absorber extends and contracts, the hydraulic oil in the cylinder passes through the choke, and the fourth leaf valve is bent to generate a damping force. When is high , It is possible to generate a damping force by bending all leaf valve.

That is, in this valve structure, a damping force proportional to the piston speed can be generated (see, for example, Patent Document 1).
JP 2001-165224 A (paragraph numbers 0039 to 0040, FIGS. 1 and 4)

  In the valve structure as described above, it may be pointed out that there is a possibility of causing the following problems.

  That is, in the conventional valve structure, when trying to secure the flow rate and trying to enlarge the port, the diameter of the port is inevitably brought close to the width of the window, or the width dimension in the radial direction of the window depending on the enlarged port. Therefore, it is necessary to reduce the outer peripheral diameter of the annular fixing portion, that is, to reduce the width of the annular fixing portion.

  However, if the diameter of the port is made closer to the width of the window, burring may occur in the valve seat due to drilling to form the port in the piston, and it is necessary to remove this burr separately, which increases the number of processing steps and costs. Become high.

  On the other hand, when the width of the annular fixing part is reduced, the area of the fixing part is reduced, so that the pressure acting on the fixing part increases during the leaf valve assembly work, which causes deformation of the fixing part. There is a problem that the damping force varies.

  As long as the outer diameter of the piston part is increased, the area of the fixed part can be reduced. However, the material cost, the total weight, and the oil amount of the shock absorber to which the piston part is applied Because it is disadvantageous in terms of, must be avoided.

  Therefore, the present invention is to provide a valve structure that can reduce the processing cost and generate a uniform damping force even when the port diameter is increased.

In order to solve the above-described object, the valve structure in the problem solving means of the present invention is formed by laminating each of the above-mentioned ports stacked on a valve body in which an annular groove communicating with each of a plurality of ports arranged on the same circumference is formed. In the valve structure having a leaf valve that opens and closes, the annular groove is formed at a position where the width dimension is set to be smaller than the port diameter, and a circle passing through the inner edge of the port enters within the width, and the leaf in the valve body The fixing portion for contacting the valve is formed on the outer side with the annular groove as a boundary.

According to the present invention, when a port having the same diameter is opened in the valve body, the area of the fixing portion is larger than the area of the fixing portion of the conventional valve structure.

  And since the area of a fixing | fixed part becomes large compared with the conventional valve structure, even if it tightens a leaf valve with predetermined | prescribed fastening force, a surface pressure will become small.

  Then, even when the port diameter is increased, the area of the fixed portion when the port diameter is not increased can be secured, and the pressure acting on the fixed portion does not become excessive.

  Therefore, even if the port diameter is increased, the area of the fixing portion is ensured, so that the deformation of the fixing portion is prevented, thereby preventing a problem that the generated damping force varies.

  In addition, even if the port diameter is increased, the area of the fixed part is secured, so it is possible to open the port eccentrically to the fixed part side, so the port diameter is expanded toward the outer peripheral side of the window. This eliminates the problem of burring on the valve seat during drilling to form the port.

  Therefore, even when the port diameter is increased, there is no need to remove the burrs, and the number of processing steps is not increased and the cost is not increased as in the conventional valve structure.

  Furthermore, as described above, the disadvantage of increasing the port diameter is avoided, so it is not necessary to increase the outer diameter of the valve body as the port size increases, and the valve structure is applied. There is no adverse effect such as an increase in material costs such as shock absorbers, total weight, and oil amount.

Hereinafter, the valve structure of the present invention and the valve structure according to a reference example will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a piston portion of a shock absorber in which a valve structure according to a reference example is embodied. FIG. 2 is a partially enlarged plan view of a piston in which the valve structure is embodied. Figure 3 is a longitudinal sectional view of the base valve portion of the damper valve structure is embodied in a preferred embodiment of the present embodiment.

As shown in FIG. 1, the valve structure according to the reference example of the present invention is embodied in a piston portion of a shock absorber, and includes a plurality of ports 1 and a window 2 that is an annular groove communicating with each port 1. The piston 3 is a valve body, and the laminated leaf valve 10 is a leaf valve that opens and closes the downstream end of the port 1.

  On the other hand, a shock absorber in which this valve structure is embodied is well known and will not be described in detail, but specifically, for example, a cylinder 20 and a head member for sealing the upper end of the cylinder 20 (not shown). ), A piston rod 21 slidably penetrating a head member (not shown), a piston 3 provided at an end of the piston rod 21, and a sealing member (not shown) for sealing the lower end of the cylinder 20. Z)).

  Further, the reduced diameter portion 22 of the piston rod 21 includes a valve stopper 23, a spacer 24, a pressure side leaf valve 25, a piston 3 and a laminated leaf valve 10 in which the present valve structure is embodied, 26 is inserted, and each member is fixed to the piston rod 21 by a piston nut 27.

  Specifically, the laminated leaf valve 10 is laminated on the annular first leaf valve 11 facing the port 1 and having a C-shaped long hole, and the first leaf valve 11, and the like in the circumferential direction. An annular second leaf valve 12 having four arc-shaped elongated holes provided at intervals, and a choke that communicates the elongated hole with the outer periphery, and an annular second leaf valve 12 stacked on the second leaf valve 12. 3 and a fourth leaf valve 14 having a smaller diameter than the third leaf valve 13 laminated on the third leaf valve 13, and the piston speed when the shock absorber is expanded and contracted. When the pressure is low, the hydraulic oil in the cylinder 20 passes through the choke in the second leaf valve 12 and deflects the third leaf valve 13 to generate a damping force. high Expediently, it is possible to generate a damping force by bending the entire laminated leaf valve 10.

  Further, the piston 3 has a plurality of ports 1 formed on the same circumference communicating the rod side chamber R1 and the piston side chamber R2, and further arranged on the same circumference on the outer circumference side of the pressure side port. Further, each port 1 is communicated with a window 2 which is an annular groove formed at the lower end of the piston 3 in FIG.

  The window 2 which is an annular groove is configured to include an annular portion 2a and a plurality of expanded portions 2b at the port 1 opening site, and the radial width w of the annular portion 2a is the diameter of the port 1 While being set smaller, the window 2 is formed at a position where a circle c shown by a broken line in FIG.

  Moreover, the expansion part 2b in the port 1 opening part is formed so as to expand with a predetermined gradient from the edge part of the port 1, as shown in FIG.

  A valve seat 5 on which the laminated leaf valve 10 is seated is formed with the outer periphery of the window 2 as a boundary, and the port 1 can be opened and closed when the laminated leaf valve 10 is seated on and off the valve seat 5. It has become.

  On the other hand, the fixed part 4 with which the inner peripheral side of the upper end in FIG. 1 of the laminated leaf valve 10 in the piston 3 abuts is formed on the inner peripheral side of the window 2 as a boundary. That is, as shown in FIG. 2, the fixing portion 4 has an annular shape and is formed so that its outer peripheral side protrudes between the ports 1 arranged on the same circumference.

  Specifically, the fixed portion 4 includes an annular portion 4a and a protruding portion 4b that protrudes between the adjacent port 1 and the port 1, and the protruding portion 4b passes through the outer edge of each port 1 c. And a circle d formed by a circle d passing through the inner edge.

  Therefore, when a port having the same diameter is opened in the valve body, the area of the fixing part 4 is larger than the area of the fixing part of the conventional valve structure.

  The laminated leaf valve 10 is brought into pressure contact with the fixed portion 4 with a predetermined tightening force by the piston nut 27, but the area of the fixed portion 4 is larger than that of the conventional valve structure. Even if is tightened with a predetermined tightening force, the surface pressure is reduced.

  Then, even when the port diameter is increased, the area of the fixed portion when the port diameter is not increased can be secured, and the pressure acting on the fixed portion 4 does not become excessive.

  Therefore, even if the port diameter is increased, the area of the fixing portion 4 is ensured, so that deformation of the fixing portion 4 is prevented, thereby preventing a problem that the generated damping force varies.

  Further, even if the port diameter is increased, the area of the fixing portion 4 is ensured, so that the port 1 can be opened eccentrically toward the fixing portion 4 side. Since it is not necessary to enlarge the port diameter, the problem that the valve seat 5 is burred at the time of drilling to form the port 1 is also eliminated.

  Therefore, even when the port diameter is increased, there is no need to remove the burrs, and the number of processing steps is not increased and the cost is not increased as in the conventional valve structure.

  Furthermore, since the inconvenience of increasing the port diameter as described above is avoided, it is not necessary to cope with the increase in the outer peripheral diameter of the piston 3 which is the valve body as the port 1 becomes larger. There is no adverse effect such as an increase in material cost, total weight, and oil amount of the buffer to which the structure is applied.

  Even if the fixed portion 4 is configured as described above, the width dimension w of the window 2 is set to the same width as that of the conventional valve structure regardless of whether the port diameter is increased or not. The pressure receiving area of the laminated leaf valve 10 can be increased by the plurality of expanded portions 2b at the port 1 opening site, that is, the pressure receiving area of the first leaf valve 11 can be increased. The entire laminated leaf valve 10 can be uniformly bent without the leaf valves 11, 12, 13, and 14 being bent apart, and a uniform damping force can also be generated in this respect.

In the above description, the case where the valve structure according to the reference example of the present invention is embodied in the piston portion of the shock absorber has been described, but it is needless to say that the valve structure may be embodied in the base valve portion. 3, a fixed portion 31 is disposed on the outer peripheral side of the valve body 30 and the inner peripheral side of the leaf valve 32, as in the base valve portion in which the valve structure of the embodiment of the present invention illustrated in FIG. 3 is embodied. Even when the port 34 is opened and closed by contacting the valve seat 33, the fixed portion 31 is formed so as to protrude between the ports 34, so that the fixed portion can be formed even if the port diameter is increased. Since the area of 31 can be secured, it is possible to achieve the same operational effects as the valve structure according to the reference example described above.

  Further, in each of the above-described embodiments, the case where the ports are arranged on the same circumference has been described. However, even when the ports are arranged on a straight line, a fixed portion is provided between adjacent ports. Since the area of the fixing portion can be secured by forming the protrusions, the effects of the present invention are not lost.

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

It is a longitudinal cross-sectional view of the piston part of the shock absorber by which the valve structure concerning a reference example was embodied. It is a partial enlarged plan view of the piston which embodied the valve structure. It is a longitudinal cross-sectional view of the base valve part of the shock absorber in which the valve structure in one embodiment of the present invention was embodied.

Explanation of symbols

1, 34 Port 2 Annular groove window 2a Annular part 2b at window Expanded part 3 at window 3 Piston 4, 31 as valve body Fixed part 4a Annular part 4b at fixed part Projecting part at fixed part 5,33 Valve seat 10 Leaf valve Laminated laminated leaf valve 11 First leaf valve 12 Second leaf valve 13 Third leaf valve 14 Fourth leaf valve 20 Cylinder 21 Piston rod 22 Reduced diameter portion 23 Valve stoppers 24, 26 Spacer 25 Pressure side leaf valve 27 Piston nut 28 Pressure side port 30 Valve body 32 Leaf valve

Claims (1)

In a valve structure having a leaf valve that is stacked on a valve body in which an annular groove communicating with each of a plurality of ports arranged on the same circumference is formed and opens and closes each port, the annular groove has a width dimension of It is set smaller than the port diameter, and is formed at a position where a circle passing through the inner edge of the port enters within the width, and a fixing portion that contacts the leaf valve in the valve body is formed outside with the annular groove as a boundary. A valve structure characterized by that.

Images