JP4726056B2 - Valve structure - Google Patents

Description

  The present invention relates to an improved valve structure.

  Conventionally, this type of valve structure is embodied in, for example, a piston portion of a shock absorber for a vehicle or the like, and this piston portion includes a plurality of ports provided on the same circle and each port. There is known one having an opening window formed of a recess communicating with the outlet end, a seat portion surrounding the outer periphery of the opening window, and an annular leaf valve stacked on the seat portion to open and close a port (for example, Patent Document 1).

In this valve structure, since the port Po1 allows only the flow of hydraulic oil in one direction due to the presence of the leaf valve, the flow of hydraulic oil in the reverse direction is allowed as shown in FIG. Therefore, a plurality of separate ports Po2 are generally formed by shifting in the circumferential direction from the formation position of the port Po1, and therefore, the seat portion S has a leaf valve L as shown in FIG. 6 is provided so as to protrude from the outlet end of the other port Po2 to the leaf valve L side, and the shape of the valve seat portion S viewed from the front is shown in FIG. As described above, each port Po2 has a substantially flower shape so that it can avoid another port Po2, and a single petal portion surrounds one open window W. Thereby making it possible to close the only door Po1 in the leaf valve L.
JP 2002-227903 A (paragraph number 0036, FIG. 2 (C))

  However, in the valve structure as described above, it may be pointed out that there are the following problems.

  That is, as described above, the seat portion serving as the valve seat has the above-described shape and surrounds each opening window W, so that the hydraulic oil that is going to pass through the port Po1 is an annular leaf. Only a part of the valve L is pressed.

  Therefore, the leaf valve L bends with the inner peripheral spacer K as a fulcrum under the pressure of the hydraulic oil that tries to pass through the port Po1, but the pressure acting on the leaf valve L is evenly distributed over the entire circumference. Since it does not act, the annular leaf valve L bends in the circumferential direction in addition to the bend of the spacer K fulcrum. As a result, an excessive load is applied to the leaf valve L, and a large stress is applied. As a result, the fatigue of the part of the leaf valve L that opposes each of the opening windows W becomes intense, and the durability of the leaf valve L may be reduced.

  Therefore, the present invention has been developed to improve the above-mentioned problems, and an object of the present invention is to provide a valve structure capable of improving the durability of a leaf valve.

In order to solve the above-described object, the problem solving means in the present invention surrounds a plurality of ports provided on the same circle, a plurality of opening windows communicating with the outlet end of each port, and the outer periphery of the opening end of each opening window. In a valve structure including a valve body including a seat portion, and a leaf valve that contacts the seat portion and is stacked on the valve body, and each port and a leaf valve that opens and closes, the seat is opened from both circumferential ends of each opening window. A notch inclined toward the part is formed.

According to the valve structure of the present invention, since the notches that are inclined from both ends in the circumferential direction of each opening window are formed, the force acting on the leaf valve is the pressure of the hydraulic oil directly received from the opening window. And the force received by the jet of hydraulic oil that passes through the notch in an obliquely upward direction. The force does not act on only a part of the leaf valve in the circumferential direction, but the force that pushes up uniformly over the entire circumference of the leaf valve. The leaf valve will not bend so as to swell in the circumferential direction.

  Therefore, in this valve structure, since the leaf valve does not bend in a circumferential direction, a large stress is not applied to the leaf valve, and an excessive load is not applied. Will be improved.

  Further, since the durability of the leaf valve is improved, the leaf valve has a long life and the reliability of the valve in which the valve structure is embodied is improved.

  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 piston portion of a shock absorber in which a valve structure according to an embodiment is embodied. FIG. 2 is a front view of a piston portion in which the valve structure according to the embodiment is embodied. FIG. 3 is an enlarged AA cross-sectional view of a piston portion in which the valve structure in one embodiment is embodied. FIG. 4 is an enlarged cross-sectional view of an opening window in which a valve structure according to a modification of the embodiment is embodied. FIG. 5 is a diagram illustrating a state in which the leaf valve of the valve structure according to the embodiment is separated from the seat portion.

  As shown in FIG. 1, the valve structure in one embodiment is embodied as an extension-side damping valve of a piston portion of a shock absorber, and includes a plurality of ports 2 provided on the same circle and outlet ends of the respective ports 2. The piston 1 is a valve body including a plurality of opening windows 3 communicating with each other and a seat portion 4 surrounding the outer periphery of the opening end of each opening window 3, and the piston 1 is abutted on the seat portion 4 and stacked on the piston 1 which is a valve body. A leaf valve 10 is provided.

  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 40 and a head member (not shown) that seals the upper end of the cylinder 40. ), The rod 5 slidably penetrating the head member (not shown), the piston 1 provided at the end of the rod 5, and the upper chamber 41 and the lower chamber partitioned by the piston 1 in the cylinder 40 42 and a sealing member (not shown) for sealing the lower end of the cylinder 40, and the cylinder 40 is filled with hydraulic oil.

  When the piston 1 moves downward in FIG. 1 with respect to the cylinder 40, the valve structure is operated via the port 2 from the lower chamber 42 to the upper chamber 41 when the pressure in the lower chamber 42 increases. When the oil moves, the leaf valve 10 provides resistance to the movement of the hydraulic oil to cause a predetermined pressure loss, thereby functioning as a damping force generating element that generates a predetermined damping force in the shock absorber.

  Hereinafter, the valve structure will be described in detail. The piston 1 that is a valve body is formed in a disk shape having an insertion hole 1a through which a rod 5 of a shock absorber is inserted in an axial center portion, and a plurality of pistons 1 provided on the same circle. The port 2 includes a plurality of opening windows 3 communicating with the outlet ends of the respective ports 2, and a sheet portion 4 formed on the outer peripheral side of each opening window 3 and surrounding each opening window 3.

  In addition to the port 2, the piston 1 has a port 50 that allows the hydraulic oil to move from the upper chamber 41 to the lower chamber 42, as shown in FIG. 2. The seat portion 4 has a substantially flower shape as in the conventional valve structure, and in the drawing, the seat portion 4 is formed in four opening windows 3. Correspondingly, four petal portions 4 a are provided, one petal portion 4 a surrounds one opening window 3, and the seat portion 4 protrudes from the inlet end of the port 50 toward the leaf valve 10. Therefore, even if the leaf valve 10 is stacked on the seat portion 4, the port 50 is not blocked.

  As shown in FIGS. 2 and 3, the circumferential direction of each opening window 3 is directed from the circumferential ends 3a, 3b toward the seat portion 4, specifically toward the side portions 4b, 4c of the petal portion 4a. Thus, notches 20 and 21 are formed.

  As shown in FIGS. 2 and 3, the notches 20 and 21 have triangular groove shapes that are inclined so as to widen the circumferential width w1 of the opening window 3 from the opening window 3 side toward the leaf valve 10 side. ing.

  In addition, as shown in FIG. 4, the notches 20 and 21 may be provided so as to completely divide the side portions 4b and 4c of the petal portion 4a in the seat portion 4. In this case, the leaf valve 10 is provided in the seat portion. 4, the orifice is formed by the notches 20 and 21. Actually, when the port 2 is completely closed by the sticking of the leaf valve 10 to the seat portion 4, the responsiveness in generating the damping force is deteriorated. Therefore, an orifice is separately provided, as shown in FIG. In this case, since the notches 20 and 21 function as orifices, it is not necessary to provide the above-mentioned orifices separately, so that there is an advantage that the processing cost is reduced. Note that both notches 20 and 21 function as orifices, but only one of them may function as an orifice.

  Returning, the rod 5 is inserted into the insertion hole 1a of the piston 1, and the tip of the rod 5 is protruded upward in FIG. Although not shown, the outer diameter of the tip of the rod 5 is set to be smaller than the outer diameter of the lower side (not shown), and a step portion (not shown) is formed at a portion where the outer diameters of the lower side and the tip are different. ing.

  Then, the leaf 1 is inserted into the tip of the rod 5 into the leaf valve 10 and the spacer 25, and the piston 1 is screwed onto the tip of the rod 5 from above the spacer 25 in FIG. And is fixed to the rod 5.

  Further, the leaf valve 10 stacked on the piston 1 is formed in an annular shape to allow the insertion of the rod 5 into the shaft center portion, and its outer diameter abuts on the seat portion 4 to close the opening window 3. The diameter that can be done.

  That is, by closing the opening window 3 with the leaf valve 10, the port 2 can also be closed, and the operation to move from the lower chamber 42 to the upper chamber 41 via the port 2 is performed. The port 2 can be opened by being separated from the seat portion 4 by being bent by receiving pressure from the oil.

  In this case, the leaf valve 10 is constituted by a single annular plate, but may be constituted by laminating an arbitrary number of annular plates depending on the damping characteristics realized by the present valve structure.

  Next, the operation of the valve structure will be described. As described above, when the piston 1 moves downward in FIG. 1 with respect to the cylinder 40, the pressure in the lower chamber 42 increases, and the hydraulic oil in the lower chamber 42 increases. It tries to move into the upper chamber 41 through the port 2.

Then, the hydraulic oil pushes the leaf valve 10 upward in FIG. 5 to be separated from the seat part 4 and flows into the upper chamber 41 through a gap formed between the seat part 4 and the leaf valve 10. Part of the hydraulic oil that passes through the notches 20 and 21 becomes a jet in an obliquely upward direction, which is the circumferential direction of the opening window 3, and pushes up the leaf valve 10 upward in the drawing.

  Then, the leaf valve 10 has its outer peripheral side upward in FIG. 1 with the spacer 25 as a fulcrum by the pressure of the hydraulic oil directly received from the opening window 3 and the jet of hydraulic oil passing through the notches 20 and 21. The port 2 is opened by bending away from the seat portion 4. Then, the hydraulic oil moves from the lower chamber 42 to the upper chamber 41 through a gap formed between the leaf valve 10 and the seat portion 4, and the shock absorber is commensurate with the pressure loss generated when the hydraulic oil passes through the gap. A damping force will be generated.

  As described above, the notches 20 and 21 are formed from both ends of each opening window 3 in the circumferential direction, so that the force acting on the leaf valve 10 is the pressure of the hydraulic oil directly received from the opening window 3. The force received by the jet of hydraulic oil passing through the notches 20 and 21 is not a force acting only on a part of the leaf valve 10 in the circumferential direction, but a force that pushes up uniformly over the entire circumference. Thus, the leaf valve 10 bends with the spacer 25 as a fulcrum and does not bend in the circumferential direction.

  Therefore, in this valve structure, the leaf valve 10 does not bend in the circumferential direction, so that a large stress does not act on the leaf valve 10 and an unreasonable load is not applied. The durability of 10 will be improved.

  Further, since the durability of the leaf valve 10 is improved, the leaf valve 10 has a long life, and the reliability of the valve in which the valve structure is embodied is improved.

  4 has the same function as the notches 20 and 21 shown in FIG. 3 except that the notches 20 and 21 in the valve structure shown in FIG. 4 also function as orifices. Therefore, the valve structure shown in FIG. Can play.

  Further, the shape of the notches 20 and 21 may be any shape that causes a jet flow in the direction of the circumferential direction of the opening window 3 as described above when the hydraulic oil passes. It may be U-shaped.

  This is the end of the description of the embodiment of the valve structure, but the valve structure of the present invention can be embodied in the compression side damping valve of the piston portion of the shock absorber, or in the base valve portion. Of course, the present invention can be applied to a damping valve that functions as a damping force generating element that generates a damping force.

 It should be noted that the scope of the present invention is not limited to the details shown or described.

It is a longitudinal cross-sectional view of the piston part of the shock absorber in which the valve structure in one embodiment was embodied. FIG. 2 is a front view of a piston portion in which the valve structure according to the embodiment is embodied. It is an expanded AA sectional view of the piston part by which the valve structure in one embodiment was embodied. It is an expanded sectional view in the opening window by which the valve structure in the modification of one embodiment was embodied. It is a figure which shows the state which the leaf valve of the valve structure in one Embodiment separated from the seat part. It is a front view of the piston part of the conventional valve structure. It is a longitudinal cross-sectional view of the piston part of the conventional valve structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Piston 1a which is a valve body 2 Insertion hole 2 Port 3 Opening window 3a, 3b Both ends 4 Seat part 4a Petal part 4b, 4c Side part 5 Rod 10 Leaf valve 20, 21 Notch 25 Spacer 30 Piston nut 40 Cylinder 41 Upper chamber 42 Lower room 50 port

Claims (2)

A valve body having a plurality of ports provided on the same circle, a plurality of opening windows communicating with the outlet ends of the respective ports, a seat portion surrounding the outer periphery of the opening end of each opening window, and a valve in contact with the seat portion A valve structure including a leaf valve that is stacked on a body and that opens and closes each port , and a notch that is inclined from both circumferential ends of each opening window toward a seat portion is formed. Construction. The valve structure according to claim 1, wherein the notch also serves as an orifice.

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