JP2011094779A - Valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve having no abrupt change of a damping force at a switching point of a damping property. <P>SOLUTION: In order to solve the problem, according to a problem solving means, in the valve including a valve disc 1 including a plurality of ports 2 and a valve seat 4 surrounding opening ends of the ports 2, and a leaf valve 8 laminated on the valve disc 1 and seating on or separating from the valve seat 4 to open and close the ports 2, a contact width in which the relief valve 8 contacts with a port outer peripheral side of the valve seat 4 as viewed from the center of the valve disc 1 is varied in a stepped or stepless manner in the circumferential direction. <P>COPYRIGHT: (C)2011,JPO&amp;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 seated on a valve seat that surrounds the valve seat, and the leaf valve is used to open and close the port.

  On the other hand, in the shock absorber for the vehicle, in order to improve the ride comfort in the vehicle, the vibration of the vehicle is firmly damped by raising the damping force in the region where the piston speed is low, and the piston speed is somewhat At higher speeds, the damping coefficient is reduced to prevent excessive damping force.

  In order to realize the damping characteristics as described above, the valve that opens and closes the port by bending the outer peripheral side of the leaf valve as described above includes, for example, an orifice formed by a notch provided on the outer periphery of the leaf valve. When the piston speed is low, the hydraulic oil moving from the pressure chamber compressed in the shock absorber to the expanded pressure chamber is allowed to pass through the orifice so that the damping characteristic (which is a square characteristic peculiar to the orifice) (Damping force change with respect to piston speed) Exhibits a damping force. When the piston speed goes out of the low speed range and becomes high speed, the leaf valve is separated from the valve seat to open the port, and the damping coefficient becomes smaller than the orifice. A damping force is exerted at (for example, see Patent Document 1).

JP 2001-165224 A

  By the way, the liquid used for the shock absorber generally has a high viscosity, and a phenomenon occurs in which the leaf valve is adsorbed and stuck to the valve seat due to the liquid. This adsorption prevents the leaf valve from moving away from the valve seat, and thus acts to increase the valve opening pressure at which the leaf valve separates from the valve seat, but once the leaf valve has separated from the valve seat. When the valve is opened, the adsorption force is eliminated, so that the port is greatly opened at once.

  Therefore, in the conventional valve, as shown by the broken line in FIG. 8, when the piston speed at which the leaf valve separates from the valve seat is in the high speed region, the damping characteristic peculiar to the orifice when the piston speed is in the low speed region. At the switching point of the damping characteristics, there is a risk that the damping force will change greatly to give vibration to the vehicle body or generate abnormal noise.

  Accordingly, the present invention has been developed to improve the above-described problems, and an object of the present invention is to provide a valve that does not exhibit a sudden damping force change at a switching point of damping characteristics. It is.

  In order to solve the above-described object, the problem solving means in the present invention includes a valve disk having a plurality of ports and a valve seat surrounding the open ends of these ports, and a valve disk stacked on the valve disk and seated on the valve seat. In a valve equipped with a leaf valve that opens and closes the port, the contact width of the leaf valve contacting the port outer periphery of the valve seat as viewed from the center of the valve disc is changed stepwise or steplessly in the circumferential direction. It is characterized by.

  According to the valve of the present invention, at the switching point at which the damping characteristic is switched, the port is not fully opened at once, and the port is gradually opened from the portion where the adsorption force is small, so the damping characteristic is gradually switched, A sudden change in the damping force can be suppressed, and problems such as giving vibration to the vehicle body or generating abnormal noise can be solved.

It is a top view of the piston which is a valve disc by which the valve in a first embodiment was embodied. It is AA sectional drawing of the valve | bulb in 1st embodiment applied to the buffer. It is a bottom view of the piston which is a valve disc in which the valve in a second embodiment was embodied. It is a top view of the piston which is a valve disc by which the valve in a third embodiment was embodied. It is a top view of the piston which is a valve disc by which the valve in a fourth embodiment was embodied. It is a top view of the piston which is a valve disc in which the valve in a fifth embodiment was embodied. It is a top view of the piston which is a valve disc by which the valve in a 6th embodiment was embodied. It is a figure which compares the damping characteristic of the buffer of this invention, and the damping characteristic of the conventional buffer.

  The valve structure of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the valve in the first 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. And a piston 1 as a valve disc comprising a plurality of pressure-side ports 2 communicating with the pressure-side chamber 42 and the extension-side chamber 41, and a valve seat 4 surrounding the open end of the port 2 on the upper end side in FIG. 1 and the tip 7 of the piston rod 6 as an axis rising from the center of the piston 1 and the inner peripheral side are fixed to the tip 7 of the piston rod 6 and stacked on the end surface of the piston 1 on the side of the extension side chamber 41 and seated on the valve seat 4 2 is provided with an annular leaf valve 8 that opens and closes 2.

  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 reservoir 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 liquid such as hydraulic oil, specifically, hydraulic oil. , It is used by being interposed between a vehicle body and an axle of the vehicle.

  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 pressure side port 2 and moves from the pressure side chamber 42 to the extension side chamber 41, A resistance is applied to the flow of the hydraulic oil by the leaf valve 8 to cause a predetermined pressure loss to generate a predetermined compression side damping force in the shock absorber.

  In addition to the pressure-side port 2 described above, the piston 1 includes a plurality of expansion-side ports 3 communicating with the expansion-side chamber 41 and the pressure-side chamber 42, and a valve surrounding the opening end of the port 3 on the lower end side in FIG. The port 3 is provided with a seat 5 and is opened and closed by an annular leaf valve 9 whose inner peripheral side is fixed to the tip 7 of the piston rod 6 and stacked on the end surface of the piston 1 on the pressure side chamber 42 side. These constitute the valve in the second embodiment, the piston 1 moves upward in FIG. 2 with respect to the cylinder 40, and the hydraulic oil passes through the port 3 on the expansion side to move from the expansion side chamber 41 to the compression side chamber 42. When moving, a resistance is applied to the hydraulic oil flow by the leaf valve 9 to cause a predetermined pressure loss to generate a predetermined extension side damping force in the shock absorber.

  Hereinafter, the valve will be described in detail. As shown in FIG. 1, the piston 1 serving as a valve disk is formed in an annular shape with an insertion hole 1 a through which the tip 7 of the piston rod 6 is inserted, and hydraulic oil is compressed side chamber 42. The compression-side port 2 that allows passage from the expansion-side chamber 41 to the compression-side chamber 42, and the expansion-side port 3 that allows hydraulic oil to pass from the expansion-side chamber 41 to the compression-side chamber 42.

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

  Further, as shown in FIGS. 1 and 2, the piston 1 is on the side of the extension side chamber 41, and has an annular portion 4 a formed around the insertion hole 1 a, and an annular portion 4 a connected to each port 2. It has a petal-shaped valve seat 4 that protrudes toward the expansion side chamber 41 with a surrounding portion 4b that surrounds the window 10 that is an open end independently of the window 10 of the other port 2, and includes an annular portion 4a and a surrounding portion. 4b is flush with the inner peripheral portion of the leaf valve 8 in the annular portion 4a and the outer peripheral portion of the leaf valve 8 in the surrounding portion 4b. 8 are stacked.

  In this way, the leaf valve 8 is seated on the 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 port 3 is connected to the extension side chamber 41. Communication is secured.

  Moreover, the surrounding part 4b has the outer peripheral part 4c arrange | positioned at the outer peripheral side of each port 2 seeing from the center of piston 1 as a valve disc, as shown in FIG. The outer peripheral portion 4c shown in FIG. 1 has an arc shape, but is not limited thereto, and may be a linear shape, a polygonal line shape that protrudes toward the outer peripheral side, or the like.

  Then, the radial width in the entire circumferential length of the outer peripheral portion 4 c in the surrounding portion 4 b surrounding one port 2 is different from the radial width in the circumferential total length of the outer peripheral portion 4 c in the surrounding portion 4 b surrounding the other port 2. It is. Specifically, the radial widths of the outer peripheral portions 4c of the four surrounding portions 4b are set to 0.2 mm, 0.3 mm, 0.4 mm, and 0.5 mm so as to be different from each other.

  It should be noted that the entire radial width of the entire outer circumferential portion 4c of the surrounding portion 4b surrounding the arbitrary port 2 is different from the radial width of the entire outer circumferential portion 4c of the surrounding portion 4b surrounding the other port 2 in the circumferential direction. For example, the radial width of the outer peripheral portion 4c of the surrounding portion 4b surrounding the two ports 2 that are arbitrarily selected is changed to another setting. Different from the radial width of the outer peripheral portion 4c of the surrounding portion 4b surrounding the two ports 2, the radial width of each outer peripheral portion 4c is set to 0.3 mm, 0.3 mm, 0.5 mm, and 0.5 mm, respectively. Or 0.3 mm, 0.4 mm, 0.4 mm, and 0.5 mm. Moreover, the outer peripheral part 4c set by the specific numerical value as mentioned above does not need to be arranged in the above-described order in the circumferential direction, and the specific numerical value setting of the radial width is an example and is limited to the above. It is not a thing.

  Thus, although the valve seat 4 is made into a petal shape, it is also possible to adopt a structure in which each surrounding portion 4b is separated and provided independently from the annular portion 4a formed around the insertion hole 1a. is there. Each outer peripheral portion 4c is provided with a recess 4d, and the recess 4d forms an orifice in a state where the leaf valve 8 is seated on the valve seat 4.

  Further, as shown in FIGS. 2 and 3, the piston 1 includes a valve seat 5 that surrounds the open end of the port 3 on the pressure side chamber 42 side. A leaf valve 9 is seated on the valve seat 5. The valve seat 5 surrounds an annular portion 5a formed around the insertion hole 1a and a window 11 which is an open end of each port 3 connected to the annular portion 5a independently of the windows 11 of the other ports 2. The surrounding portion 5b is a petal-type valve seat that protrudes toward the pressure side chamber 42. The annular portion 5a and the surrounding portion 5b are flush with each other, and the inner peripheral portion of the leaf valve 9 is formed on the annular portion 5a. The leaf valve 9 is laminated on the valve seat 5 so that the outer peripheral portion of the leaf valve 9 is seated on the surrounding portion 5b.

  In this way, the leaf valve 9 is seated on the valve seat 5 provided so as to protrude to the lower end in FIG. 2 of the piston 1, so that only the port 3 is closed by the leaf valve 9 and the port 2 is connected to the pressure side chamber 42. Communication is secured.

  Moreover, the surrounding part 5b has the outer peripheral part 5c arrange | positioned at the outer peripheral side of each port 2 seeing from the center of piston 1 as a valve disc, as shown in FIG. In addition, although the outer peripheral part 5c shown in FIG. 3 is made into circular arc shape, it is not limited to this, You may be made into linear form, a broken line form, etc.

  And the radial width in at least a part of the circumferential total length of the outer peripheral portion 5c in the surrounding portion 5b surrounding one port 2 is made different from the radial width of other portions. Specifically, the radial width of the outer peripheral part 5c of each surrounding part 5b is set to 0.2 mm at the central part and 0.5 mm at the other parts so that it differs from other parts at the central part. is there. Furthermore, the circumferential length in the central portion having a radial width of 0.2 mm is set to be different in each surrounding portion 5b.

  In the above specific numerical value setting, the radial width of the outer peripheral portion 5c of each surrounding portion 5b is set to be stepwise different in the circumferential direction, but may be set to be steplessly different, The specific numerical value setting is an example and is not limited to the above.

  In addition, the valve seat 5 has a petal shape, but similarly to the valve seat 4, a structure in which each surrounding portion 5b is separated and provided independently from the annular portion 5a formed around the insertion hole 1a is adopted. It is also possible to do. Each outer peripheral portion 5 c is provided with a recess 5 d, and the recess 5 d forms an orifice in a state where the leaf valve 9 is seated on the valve seat 5.

  In this case, four ports 2 and 3 are provided, but the number of ports 2 and 3 is arbitrary, and the number of surrounding portions 4b and 5b of the valve seats 4 and 5 is also the same as that of the ports 2 and 3. What is necessary is just to provide so that it may correspond to the number of installation.

  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.

  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 orifice formed by the recess 4d provided in the valve seat 4 and the leaf valve 8. Until the piston speed reaches the high speed region and the leaf valve 8 bends and separates from the surrounding portion 4b, the damping characteristic generated by the shock absorber is characteristic of the orifice, and the damping force is proportional to the square of the piston speed. To change.

  On the other hand, when the piston speed reaches the high speed region, the leaf valve 8 is separated from the surrounding portion 4b to open the port 2. Here, the radial width of the outer peripheral portion 4c in the surrounding portion 4b surrounding the arbitrary port 2 is different from the radial width of the outer peripheral portion 4c in the surrounding portion 4b surrounding the other port 2, and the outer periphery having a small radial width. Since the contact area between the portion 4c and the leaf valve 8 is smaller than the contact area between the outer peripheral portion 4c and the leaf valve 8 having a large radial width, the adsorption force generated at the outer peripheral portion 4c and the leaf valve 8 having a small contact area is The suction force generated by the outer peripheral portion 4c and the leaf valve 8 having a large contact area becomes smaller.

  Then, the valve opening pressure at which the leaf valve 8 is separated from the outer peripheral portion 4c having a small adsorption force is lower than the valve opening pressure at which the leaf valve 8 is separated from the outer peripheral portion 4c having a large adsorption force. The port 2 surrounded by the surrounding portion 4b including the outer peripheral portion 4c having the maximum suction force is opened sequentially, and the port 2 surrounded by the surrounding portion 4b including the outer peripheral portion 4c having the maximum suction force is finally opened. Become.

  In this way, at the switching point where the attenuation characteristics are switched, the port 2 is not opened at a time, but is sequentially opened from the port 2 surrounded by the surrounding portion 4b having the outer peripheral portion 4c having a small attractive force. As shown by the solid line in FIG. 8, the damping characteristics are gradually switched, a sudden change in damping force can be suppressed, and vibrations can be applied to the vehicle body. It is possible to solve the problem that abnormal noise occurs.

  On the other hand, when the piston 1 moves upward in FIG. 1 with respect to the cylinder 40, the pressure in the expansion side chamber 41 increases, and the hydraulic oil in the expansion side chamber 41 tries to move into the pressure side chamber 42 through the port 3. To do.

  When the piston speed is in the low speed region, the leaf valve 9 has a small pressure in the extension side chamber 41 acting via the port 3 and is not separated from the valve seat 5, and the port 3 remains closed. Become.

  Therefore, when the piston speed is in the low speed region, the hydraulic oil moves from the extension side chamber 41 to the pressure side chamber 42 through the orifice formed by the recess 5d provided in the valve seat 5 and the leaf valve 9. Until the piston speed reaches the high speed region and the leaf valve 9 bends and separates from the surrounding portion 5b, the damping characteristic generated by the shock absorber is characteristic of the orifice, and the damping force is proportional to the square of the piston speed. To change.

  On the other hand, when the piston speed reaches the high speed region, the leaf valve 9 is separated from the surrounding portion 5b to open the port 3. Here, the radial width of the outer peripheral portion 5c in the surrounding portion 5b surrounding each port 3 is different in a stepwise manner, and the leaf valve 9 is formed at the central portion where the radial width of the outer peripheral portion 5c is small. The attracting force generated at a location with a small radial width is smaller than the attracting force generated at a location with a large radial width.

  Moreover, the circumferential direction width in the center part where the radial direction width in the outer peripheral part 5c of each surrounding part 5b is small is different, and the said attraction force becomes smaller as the circumferential width in the central part becomes longer in each outer peripheral part 5c. It is supposed to be.

  Therefore, the leaf valve 9 is gradually separated from the port 3 surrounded by the surrounding portion 5b having the outer peripheral portion 5c having a small adsorption force and gradually away from the portion where the adsorption force of the outer peripheral portion 5c is small. Since the respective ports 3 are opened so as to form a gap therebetween, the ports 3 are gradually opened instead of being fully opened at once.

  Thus, since the port 3 is not released at a stroke but is gradually released at the switching point at which the damping characteristic is switched, the damping characteristic is gradually switched to suppress a sudden change in the damping force. It is possible to solve the problem that vibration is given to the vehicle body or abnormal noise is generated.

  Furthermore, in this case, since the leaf valve 9 is separated from the outer peripheral portion 5c and the port 3 is opened little by little from the portion where the adsorption force is small in this order, the damping force is further increased at the switching point of the damping characteristic. The changes will be smooth, the vehicle system vibration will be further improved, and the effect of suppressing abnormal noise will be further improved.

  It is also possible to set the radial width of the outer peripheral portion 5c in the surrounding portion 5b surrounding each port 3 to be steplessly different. In this case as well, the port 3 is a switching point in the attenuation characteristic. Since it is gradually released rather than being released at once, the damping characteristics are gradually switched, and sudden changes in damping force can be suppressed, giving vibration to the vehicle body or generating abnormal noise. Trouble can be solved. Further, as described above, the port 3 can be set to be opened in order by setting the outer peripheral portion 5b of each surrounding portion 5b to be different from the circumferential length of the portion where the diameter is small. It is possible to set the length in the circumferential direction to be the same, or to set only the outer peripheral portion 5c of the arbitrary surrounding portion 5b to be different from the others, which gives vibration to the vehicle body or generates abnormal noise. There is an effect that the problem can be solved.

  Further, in the above, the damping force is generated at the orifice when the piston speed is in the low speed region, but a choke passage is provided instead of the orifice so that the damping is performed when the piston speed is in the low speed region. The force may be generated by a choke path. The orifice is formed by the recesses 4d and 5d provided in the outer peripheral portions 4c and 5c, but may be formed by providing notches in the leaf valves 8 and 9 instead.

  In the above description, the valve seats 4 and 5 are petal types, and the ports 2 and 3 are independent of each other. However, like the valve in the third embodiment shown in FIG. In the case where the annular window 16 is provided so that the ports 17 communicate with each other through the annular window 16 and the valve seat 18 is annularly disposed on the outer periphery of the annular window 16, the radial width of the valve seat 18 is set in the circumferential direction. It may be changed step by step or steplessly. Specifically, the radial width of the valve seat 18 is set to change steplessly from the narrowest 0.2 mm to the widest 0.8 mm opposite to 180 degrees. The leaf valve is seated on the valve seat 18 as in the second embodiment.

  Further, like the valve in the fourth embodiment shown in FIG. 5, an annular window 16 is provided in the piston 15 as a valve disk so that each port 17 is communicated with the annular window 16, and the valve seat 19 is annular. In the case where it is disposed on the outer periphery of the annular window 16, the radial width of at least a part of the radial width of the valve seat 19 may be different from other parts. Specifically, a part of the radial width of the valve seat 19 is set to a narrow 0.2 mm, and the other part is set to a wide 0.8 mm. The leaf valve is seated on the valve seat 19 as in the embodiment. Moreover, in this example, the site | part with a narrow radial width is provided in four places, and the circumferential direction length in the said narrow location is set so that it may each differ.

  In addition, said part has shown the part with respect to the perimeter of the valve seat 19, and is not only showing one place, but the radial direction width in several places differs from the radial direction width in another place. It is also included, and furthermore, the radial widths at a plurality of locations may be different for each location.

  Even in the valves according to the third and fourth embodiments configured as described above, the leaf valve seated on the valve seats 18 and 19 starts from the valve seats 18 and 19 from a portion having a small suction force and a small radial width. The port 17 is gradually opened after being separated. Therefore, even in the valves in the third and fourth embodiments, the port 17 is not opened at a stroke at the switching point at which the damping characteristic is switched, as in the valves in the first and second embodiments. It is gradually released, so the damping characteristics can be switched gradually, and sudden changes in the damping force can be suppressed, and problems such as vibrations and abnormal noise can be eliminated. it can.

  Further, in the valve according to the fourth embodiment, the circumferential lengths of the portions of the valve seat 19 having a narrow radial width are set to be different from each other. Since the port 17 is opened little by little from the narrow part having the smallest circumferential force in the circumferential direction to the narrow part having the smallest circumferential length, the port 17 is opened little by little. Further, the damping force change becomes smoother, the vehicle system vibration is further improved, and the effect of suppressing abnormal noise generation is further improved. In addition, when there are a plurality of parts having a narrow radial width, the circumferential length in each narrow part may be set to be the same, or only an arbitrary narrow part may be set to be different from the others. is there.

  Further, in the valve according to the fifth embodiment shown in FIG. 6, as in the valve according to the first embodiment, a petal-type valve seat 21 is provided on the piston 20 as a valve disk, and a plurality of ports provided on the piston 20 are provided. 22 is enclosed independently. As in the first embodiment, the valve seat 21 includes an annular portion 21a and an enclosing portion that is connected to the annular portion 21a and surrounds the window 23 that is the open end of each port 22 independently of the windows 23 of the other ports 22. 21b, and the surrounding portion 21b includes an outer peripheral portion 21c on the outer periphery of the port 22 when viewed from the center side of the valve disk. Each outer peripheral part 21c is arrange | positioned on the same periphery, The radial direction width | variety is made into the fixed width | variety in this case. As shown by the broken line in the figure, a leaf valve 24 whose inner periphery and outer periphery are not concentric is laminated on the valve seat 21 configured as described above. It is in a state where it is seated eccentrically relative to the outer peripheral portion 21c.

  By doing in this way, the width | variety of the contact site | part which the leaf valve 24 is sitting on the outer peripheral part 21c in the valve seat 21, ie, a contact width, can be changed continuously in the circumferential direction. In this case, the leaf valve 24 is an eccentric leaf valve whose inner and outer circumferences are not concentric. However, since the outer peripheral portion 21c of the valve seat 21 and the leaf valve need only be relatively eccentric, the inner and outer circumferences are concentric. The outer peripheral portion 21c of the valve seat 21 may be eccentric with respect to the leaf valve, or both may be eccentric.

  In the valve in the sixth embodiment shown in FIG. 7, like the valve in the third embodiment, an annular valve seat 26 is provided on the piston 25 as a valve disk, and a plurality of ports 27 provided on the piston 25 are provided. To surround everything. In this case, the radial width of the valve seat 26 is constant. As shown by the broken line in the figure, a leaf valve 28 whose inner periphery and outer periphery are not concentric is laminated on the valve seat 26 configured as described above, so that a leaf valve whose inner and outer periphery is concentric is formed on the valve seat 26. It is in a state where it sits relatively eccentrically.

  By doing in this way, the width of the contact portion where the leaf valve 28 is seated on the valve seat 26, that is, the contact width can be changed steplessly in the circumferential direction. In this case, the leaf valve 28 is an eccentric leaf valve whose inner and outer circumferences are not concentric. However, since the valve seat 26 and the leaf valve need only be relatively eccentric, the leaf valve 28 has a concentric leaf valve. On the other hand, the valve seat 26 may be eccentric, or both may be eccentric.

  Now, even in the valves according to the fifth and sixth embodiments configured as described above, the leaf valves 24 and 28 seated on the valve seats 21 and 26 are arranged from a portion with a small radial force and a small suction force. The ports 22 and 27 are gradually opened away from the seats 21 and 26. Therefore, even in the valves in the fifth and sixth embodiments, the ports 22 and 27 are opened at a stroke at the switching point at which the damping characteristics are switched, as in the valves in the first and second embodiments. Rather than being released, the damping characteristics are gradually switched, so that sudden changes in damping force can be suppressed, and problems such as giving vibration to the vehicle body or generating abnormal noise are eliminated. be able to.

  Further, in the valves according to the fifth and sixth embodiments, the adsorption force can be controlled by adjusting the relative eccentricity with the leaf valves 24 and 28, and the ports 22 and 27. The valve opening pressure and opening method can be arbitrarily set. Therefore, when considering using an eccentric leaf valve as a leaf valve, preparing an eccentric leaf valve with a different eccentricity for a single valve disc in advance enables low-cost damping characteristics. There is a merit that different valves can be realized.

  Furthermore, the structure in which the leaf valve is eccentrically seated relative to the fifth and sixth valve seats can be applied to the first to fourth valve seats 4, 5, 18, and 19. In this way, the effects of the present invention can be achieved without losing the effects.

  In the present embodiment, in order to explain the change of the damping characteristic, the piston speed is provided with sections of low speed, medium speed, and high speed, but the speed of the boundary between these sections is arbitrarily set. be able to.

  Also, in the above description, the valve 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, but it is embodied only in the damping valve on the expansion side or on both sides of the pressure expansion. Further, it can also be embodied in the base valve portion, and of course can be applied to a shock absorber valve that functions as a damping force generating element that generates a damping force. It is.

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

  The present invention can be used for a valve such as a shock absorber.

1, 15, 20, 25 Piston 1a as valve disc Insertion hole 2, 3, 17, 22, 27 Port 4, 5, 15, 18, 19, 21, 26 Valve seat 4a, 5a, 21a Annular portion 4b in valve seat , 5b, 21b Enclosures 4c, 5c, 21c in the valve seats Outer peripheral parts 4d, 5d in the enclosure 6 Recess 6 Piston rod 7 Piston rod tip 8, 9, 24, 28 Leaf valve 10, 11, 23 Window 12 In the piston rod Step part 13 Screw groove 14 in the piston rod Nut 16 Annular window 40 Cylinder 41 Extension side chamber 42 Pressure side chamber

Claims (9)

A valve disc having a plurality of ports and a valve disc that surrounds the open ends of the ports, and a leaf valve that is stacked on the valve disc and is attached to and detached from the valve seat to open and close the port. The contact width with which the leaf valve contacts the outer peripheral side of the port of the valve seat as viewed from the valve is changed stepwise or steplessly in the circumferential direction. 2. The valve according to claim 1, wherein the radial width on the outer peripheral side of the port seat of the valve seat that contacts the leaf valve changes stepwise or steplessly. The valve according to claim 1, wherein the leaf valve is eccentrically brought into contact with the outer peripheral side of the port of the valve seat. The valve seat is provided with an enclosing portion that surrounds each port arranged in the circumferential direction on the valve disc independently of the other ports, and the encircling portion is arranged on the outer peripheral side of the port as viewed from the center of the valve disc. And the radial width of the entire circumferential length of the outer peripheral portion of the surrounding portion surrounding any port is different from the radial width of the entire circumferential length of the outer peripheral portion of the surrounding portion surrounding other ports. The valve according to any one of claims 1 to 3. The valve seat is provided with an enclosing portion that surrounds each port arranged in the circumferential direction on the valve disc independently of the other ports, and the encircling portion is arranged on the outer peripheral side of the port as viewed from the center of the valve disc. The radial width in at least a part of the entire circumferential length of the outer peripheral portion of the surrounding portion surrounding the arbitrary port is different from the radial width in other portions. A valve according to any one of the above. The valve seat is provided with an enclosing portion that surrounds each port arranged in the circumferential direction on the valve disc independently of the other ports, and the encircling portion is arranged on the outer peripheral side of the port as viewed from the center of the valve disc. And the outer peripheral part of each surrounding part is arranged on the same circumference with respect to the valve disc, and the leaf valve is eccentric to the circumference where the outer peripheral part is arranged and is seated on each outer peripheral part. The valve according to any one of claims 1 to 5, wherein: The valve seat is an annular valve seat that surrounds all the ports arranged in the circumferential direction on the valve disc, and the radial width of the valve seat is changed stepwise or steplessly in the circumferential direction. Item 4. The valve according to any one of Items 1 to 3. The valve seat is an annular valve seat that surrounds all the ports arranged side by side in the circumferential direction on the valve disc, and the radial width in at least a part of the total circumferential length of the valve seat is the radial width in other parts The valve according to any one of claims 1 to 3, wherein the valves are different. The valve seat has a circular shape surrounding all of the ports arranged in the circumferential direction on the valve disc, and the leaf valve is eccentric to the valve seat and is seated on the valve seat. Item 9. The valve according to any one of Items 1, 2, 3, 7 and 8.

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