JP2010025169A - Valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve not only proportionally changing damping force in a low-speed region with respect to piston speed but also manufacturable at low cost. <P>SOLUTION: This valve includes a valve disk 1 provided with ports 2 and valve seats 4 surrounding the opening ends of the ports 2, and a leaf valve 8 laminated on the valve disk 1, separated from and seated on the valve seats, and opening/closing the ports 2. In the valve, choke grooves 10 are formed in the valve seats 4, and form choke passages with the leaf valve 8 seated on the valve seats 4 from the outside of the ports 2 through the inside of the ports 2 across the valve seats 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an improved valve.

  Conventionally, this type of valve is embodied in, for example, a piston portion of a shock absorber for a vehicle, and the outer periphery of a piston that separates two pressure chambers in the shock absorber and a port provided in the piston. And an annular leaf valve that is seated on an annular valve seat that is disposed at the top and bottom, and the leaf valve is used to open and close the port.

  In the valve that opens and closes the port by bending the outer peripheral side of the leaf valve, when the piston speed is low, the working liquid passes through the orifice formed by the notch provided on the outer periphery of the leaf valve and is compressed. The pressure chamber is moved from the pressure chamber to be expanded to the pressure chamber to be expanded.

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

Therefore, in order to change the damping force linearly with respect to the piston speed in the low speed region, the leaf valve seated on the valve seat and a part of the sub leaf valve stacked on the leaf valve are provided with a notch and stacked on the top. There has been proposed a valve that closes most of the notch with a sub-leaf valve to form a choke passage (see, for example, Patent Document 1). There is also a proposal of a valve that forms a choke passage that penetrates the piston vertically apart from the port in the piston (see, for example, Patent Document 2).
JP 2001-165224 A JP 2007-132389 A

  However, the valve configured as described above may not be particularly problematic, but may be pointed out as having the following problems.

  When a choke passage is formed with a leaf valve and a sub-leaf valve, not only is it necessary to process notches in the leaf valve and sub-leaf valve, but also the positions of the notches in the leaf valve and sub-leaf valve must be aligned. The manufacturing work of the valve becomes complicated and the cost increases. In addition, since the leaf valve and the sub leaf valve are notched, the durability of the leaf valve and the sub leaf valve may be reduced.

  In addition, when the choke passage is formed in the piston, it is necessary to make a hole in the piston, and it is possible to avoid a decrease in the durability of the leaf valve, but the problem of increasing the cost is not solved. .

  Therefore, the present invention was devised to improve the above-described problems, and its object is to change the damping force in the low speed region of the shock absorber in proportion to the piston speed. It is to provide a valve that can be manufactured not only inexpensively.

  In order to solve the above-described object, the problem-solving means in the present invention includes a valve disc having a port and a valve seat surrounding the opening end of the port, and a valve disc stacked on the valve disc and seated on the valve seat to open and close the port. A valve having a leaf valve that is provided with a choke groove that is provided on the valve seat and that forms a choke passage in a state where the leaf valve is seated on the valve seat through the port seat from the outside of the port into the port. It is characterized by that.

  According to the valve of the shock absorber of the present invention, the choke passage is formed by the choke groove provided in the valve seat and the leaf valve which does not require the processing for providing the notch, so that the damping force in the low speed region of the shock absorber is the piston speed. In addition, the choke groove can be formed by a mold in which the valve disc is manufactured by sintering or casting, and the valve disc or leaf valve is specially processed when the choke passage is formed. There is no need, and the manufacturing cost of the valve can be reduced.

  Furthermore, since it is not necessary to provide a notch in the leaf valve, there is no need to align the plurality of annular plates constituting the leaf valve in the circumferential direction when the choke passage is formed, and the assembly work is facilitated.

  The valve structure of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of a piston which is a valve disc in which a valve according to an embodiment is embodied. FIG. 2 is an AA cross-sectional view of a valve in an embodiment applied to a shock absorber. FIG. 3 is a plan view of a piston which is a valve disc in which a valve according to another embodiment is embodied.

  As shown in FIGS. 1 and 2, the valve in one embodiment is embodied as a damping valve on the pressure side of the piston portion of the shock absorber, and the expansion side chamber 41 and the pressure side chamber 42 are separated in the cylinder 40. In addition, a piston 1 as a valve disk having a plurality of ports 2 communicating with the compression side chamber 42 and the expansion side chamber 41, and a valve seat 4 surrounding the open end of the port 2, and a piston as an axis rising from the center of the piston 1 The tip 7 of the rod 6 and the annular leaf valve 8 whose inner peripheral side is fixed to the tip 7 of the piston rod 6 and stacked on the end face of the piston 1 on the side of the extension side chamber 41 are seated on and off the valve seat 4 to open and close the port 2. And a choke groove 10 provided in each valve seat 4.

  On the other hand, a shock absorber in which the valve of the present invention is embodied is well known and will not be described in detail, but specifically, for example, a cylinder 40 and a head member for sealing the upper end of the cylinder 40 (FIG. A piston rod 6 that slidably passes through a head member (not shown), a piston 1 that is a valve disk that is inserted into the tip 7 of the piston rod 6 and is fixed to the tip 7, and a cylinder 40. An extension chamber 41 on the upper side, a pressure side chamber 42 on the lower side in FIG. 1 and a sealing member (not shown) that seals the lower end of the cylinder 40, and the cylinder 40 protrude from the cylinder 40. A cylinder or an air chamber (not shown) that compensates for a change in the cylinder volume corresponding to the volume of the piston rod 6 is provided, and the cylinder 40 is filled with a fluid, specifically, hydraulic oil.

  Further, in the above valve, when the piston 1 moves downward in FIG. 2 with respect to the cylinder 40 and the hydraulic oil passes through the port 2 and moves from the pressure side chamber 42 to the extension side chamber 41, the operation thereof is performed. A resistance is applied to the oil flow by the leaf valve 8 to generate a predetermined pressure loss, thereby generating a predetermined compression side damping force in the shock absorber.

  In addition to the above-described port 2, the piston 1 is provided with a plurality of ports 3 communicating with the extension side chamber 41 and the pressure side chamber 42, and the inner peripheral side of the port 3 is fixed to the tip 7 of the piston rod 6. 2 is opened and closed by an annular leaf valve 9 stacked on the end face of the piston 1 on the pressure side chamber 42 side, and the piston 1 moves upward in FIG. When moving from the expansion side chamber 41 to the compression side chamber 42 through the port 3, a resistance is applied to the flow of the hydraulic oil by the leaf valve 9 to cause a predetermined pressure loss, and a predetermined expansion side attenuation is caused in the buffer. It is designed to generate power.

  Hereinafter, the valve will be described in detail. As shown in FIG. 1, the piston 1 serving as a valve disc is formed in an annular shape, and allows the hydraulic oil to pass from the compression side chamber 42 to the extension side chamber 41. Conversely, a port 3 that allows hydraulic oil to pass from the expansion side chamber 41 to the compression side chamber 42 is provided.

  Further, a plurality of ports 2 and 3 are provided in the piston 1, specifically four each in the illustration, and are alternately arranged on the same circumference at equal intervals.

  Further, the piston 1 is provided with an annular portion 4a and a surrounding portion 4b surrounding the independent window 11 which is an open end of the port 2 on the extension side chamber 41 side, and the petals protrude toward the extension side chamber 41 side. The annular portion 4a and the surrounding portion 4b are flush with each other so that the inner peripheral portion of the leaf valve 8 is seated on the annular portion 4a and the outer peripheral portion of the leaf valve 8 is placed on the surrounding portion 4b. A leaf valve 8 is laminated on the petal-type valve seat 4 so as to be seated.

  In this manner, the leaf valve 8 is seated on the petal-type valve seat 4 provided so as to protrude to the upper end in FIG. 2 of the piston 1, so that only the port 2 is closed by the leaf valve 8 and the extension side chamber of the port 3 is closed. Communication with 41 is ensured.

  Further, as shown in FIG. 1, the independent window 11 has a convex shape, and communicates with the extension side chamber 41 that crosses the surrounding portion 4 b from the shoulder portion 11 a toward the radial direction of the piston 1 and is outside the port 2. Two choke grooves 10 are formed in the surrounding portion 4b. Therefore, the port 2 communicates with the expansion side chamber 41 through the choke groove 10 even when the leaf valve 8 is seated on the valve seat 4 and closed. Thus, the length is ensured by making the independent window 11 convex so that the choke groove 10 can function as a choke.

  The piston 1 further includes a petal-type valve seat 5 that surrounds the opening end of the port 3 on the pressure side chamber 42 side, and a leaf valve 9 is seated on the valve seat 5.

  And the front-end | tip 7 of the piston rod 6 of a buffer is penetrated by the inner peripheral side of the piston 1, and the front-end | tip 7 of the piston rod 6 is made to protrude on the downward side in FIG. Further, the outer diameter of the tip 7 of the piston rod 6 is set to be smaller than the outer diameter of the piston rod 6 on the upper side in FIG. 2 with respect to the tip 7 of the piston rod 6. 12 is formed, and a screw groove 13 is formed on the outer periphery of the lower end of the tip 7 in FIG.

  Further, the leaf valves 8 and 9 stacked on the top and bottom of the piston 1 in FIG. 1 are configured by stacking a plurality of annular plates as shown in FIG. 2, and are assembled to the tip 7 of the piston rod 6 together with the piston 1. The nut 14 is screwed into the screw groove 13 provided at the tip 7 and is fixed to the tip 7 of the piston rod 6 by being sandwiched between the step 12 of the piston rod 6.

  In this way, the leaf valves 8 and 9 are fixed to the piston rod 6 on the inner periphery and seated on the valve seats 4 and 5 to close the ports 2 and 3, respectively. The ports 2 and 3 can be opened by bending the outer peripheral side with pressure acting from the outside. The number of annular plates in the leaf valves 8 and 9 is arbitrary, and may be set to an appropriate number depending on the damping force required for the shock absorber.

  Then, in a state where the leaf valve 8 is seated on the valve seat 4, a choke passage that communicates the port 2 with the expansion side chamber 41 is formed in cooperation with the choke groove 10 provided in the surrounding portion 4 b of the valve seat 4. .

  Next, the operation of the valve 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 pressure side chamber 42 increases, and the hydraulic oil in the pressure side chamber 42 passes through the port 2 and tries to move into the extension side chamber 41. To do.

  When the piston speed is in the low speed region, the leaf valve 8 has a small pressure in the pressure side chamber 42 acting via the port 2 and does not move away from the valve seat 4, and the port 2 remains closed. Become.

  Therefore, when the piston speed is in the low speed region, the hydraulic oil moves from the compression side chamber 42 to the extension side chamber 41 via the choke passage formed by the choke groove 10 and the leaf valve 8, and the piston speed is medium. The damping characteristic generated by the shock absorber becomes a characteristic characteristic of the choke until the leaf valve 8 is bent and is separated from the surrounding portion 4b until reaching the speed region, and the damping force changes in proportion to the piston speed. .

  When the piston speed reaches the middle speed region, the leaf valve 8 is separated from the surrounding portion 4b to open the port 2, and the damping characteristic on the extension side generated by the shock absorber embodying the valve is generated. In such a case, the attenuation characteristic does not change abruptly at the boundary between the low speed region and the medium speed region.

  On the other hand, when the piston 1 moves upward in FIG. 1 with respect to the cylinder 40, the pressure in the extension side chamber 41 increases, and the hydraulic oil in the extension side chamber 41 passes through the port 3 and moves into the pressure side chamber 42. However, since the port 3 is blocked by the leaf valve 9, the hydraulic oil moves to the pressure side chamber 42 through the choke passage and the port 2. Therefore, also in this case, the damping characteristic generated by the shock absorber becomes a characteristic characteristic of the choke until the piston speed reaches the middle speed range and the leaf valve 9 bends and separates from the valve seat 5, and the damping force is It changes in proportion to the piston speed. As described above, since the choke passage has both effects of pressure expansion, it may be provided in either the expansion side or the pressure side valve, but may be provided in both.

  In this valve, the choke passage is formed by the choke groove 10 provided in the valve seat 4 and the leaf valve 8 which does not require machining to provide a notch, so that the piston 1 which is a valve disk is sintered or cast. The choke groove 10 can be formed by a mold manufactured by the above-described method, and it is not necessary to perform special processing on the piston 1 or the leaf valve 8 which is a valve disk when forming the choke passage, and the manufacturing cost of the valve can be reduced. .

  Further, since the leaf valve 8 does not need to be provided with a notch, there is no need to align the plurality of annular plates constituting the leaf valve 8 in the circumferential direction when forming the choke passage, and the assembly work is facilitated.

  Note that the number of choke grooves 10 provided in the valve seat 4 is arbitrary, and it is only necessary to provide as many as the number suitable for the damping characteristic desired to be generated in the shock absorber.

  In the above description, the valve seat 4 is a petal type and the ports 2 are independent from each other. However, like the valve in the other embodiment shown in FIG. 3, the piston 18 is provided with an annular window 19. When the ports 17 are communicated with each other through the annular window 19 and the valve seat 15 is formed by the inner peripheral portion 15a disposed on the inner periphery of the annular window 19 and the outer peripheral portion 15b disposed on the outer periphery, You may make it provide the umbilical part 15c which protrudes toward the inner peripheral side from the arbitrary locations of the outer peripheral part 15b and in which the choke groove 16 is formed. In this case, the umbilical portion 15c is flush with the outer peripheral portion 15b and is provided at equal intervals in the four circumferential directions, and the radial width is such that the choke groove 16 provided in the umbilical portion 15c can function as a choke. It is set to length. The choke groove 16 crosses the umbilical portion 15c of the valve seat 15 and communicates with an annular window 19 in which the port 17 communicates with the outside of the port 17. The number of umbilical portions 15c can be set arbitrarily according to the number of choke grooves 16 to be installed.

  Even in the valve in the other embodiments, the choke passage is formed by the choke groove 16 provided in the umbilical portion 15c and the leaf valve 8 by seating the leaf valve 8 on the valve seat 15, and the choke passage is formed. The port 17 can be communicated with the extension side chamber 41.

  Since the choke groove 16 can be formed in the piston 18 without post-processing by sintering or casting, the damping force in the low speed region is proportional to the piston speed, as with the valve in the above-described embodiment. The valve can be manufactured at a low cost.

  In the above description, the valve structure of the present invention has been described using an example embodied in the damping valve on the pressure side of the piston portion of the shock absorber. It can also be embodied, and further can be embodied in the base valve portion, and can be applied to a shock absorber valve that functions as a damping force generating element that generates a damping force. Of course.

  In the above-described embodiment, the shaft is the tip 7 of the piston rod 6. However, instead of this, a shaft that is integral with or separate from the valve disk may be provided at the center of the valve disk.

 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 top view of the piston which is a valve disc with which the valve in one embodiment was embodied. It is AA sectional drawing of the valve | bulb in one Embodiment applied to the buffer. It is a top view of the piston which is a valve disc in which the valve in other embodiments was embodied.

Explanation of symbols

1, 18 Piston 2, 3 Port 4, 5, 15 as valve disc Valve seat 4a Annular portion 4b in valve seat 6 Enclosure 6 in valve seat Piston rod 7 Piston rod tip 8, 9 Leaf valve 10, 16 Choke groove 11 Independent Window 11a Shoulder portion 12 in independent window Step portion 13 in piston rod 14 Screw groove 14 in piston rod Nut 15a Inner circumferential portion 15b in valve seat Outer circumferential portion 15c in valve seat Umbilical portion 17 in valve seat Port 19 Annular window 40 Cylinder 41 Extension side chamber 42 Pressure side chamber

Claims (1)

A valve provided with a valve disk including a port and a valve seat surrounding the open end of the port, and a leaf valve stacked on the valve disk and seated on and off the valve seat to open and close the port. A valve comprising a choke groove that forms a choke passage in a state in which a leaf valve is seated on a valve seat from outside the port to inside the port across the seat.

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