Pilot-type poppet valve and shock absorber comprising pilot-type poppet valve

Abstract

Provided is a pilot-type poppet valve (20) that comprises a main valve (80) and a pilot valve (110) and that opens and closes a flow path through which oil flows. The pilot-type poppet valve (20) has a biasing means (107) and a drive part (30). The biasing means (107) biases the main valve (80) in an opening direction (Ra). The drive part (30) is configured to be able to push both the main valve (80) and the pilot valve (110) in a closing direction (Rb).

Description

Pilot-operated poppet valve and shock absorber provided with the pilot-operated poppet valve

[0001] The present invention relates to an improved technology for a pilot-operated poppet valve and a shock absorber provided with the pilot-operated poppet valve.

[0002] For example, it is known to provide a pilot-operated poppet valve inside a shock absorber of a saddle-riding type vehicle to open and close an oil flow path. As a conventional technology in which a pilot-operated poppet valve is mounted, there is a technology disclosed in Patent Document 1.

[0003] A shock absorber as disclosed in Patent Document 1 includes a drive unit that operates when energized, a pilot valve that opens a flow path by the operation of the drive unit, and a main valve that further opens the flow path by a pressure difference when the pilot valve opens the flow path. By opening the pilot valve, which is smaller than the main valve, first, the main valve is opened using the differential pressure. Since only a small force is required to open the small pilot valve, only a small force is required to open the flow path.

[0004] Japanese Patent Application Laid-open No. 2016-176552

[0005] In a pilot-operated poppet valve such as that disclosed in Patent Document 1, the state of the main valve becomes unstable when the flow rate is from zero with no pressure difference to a very small flow rate. To avoid this, it is common practice to add a biasing means that biases the main valve in the closing direction, keep the valve closed until a pressure exceeding the biasing force of the biasing means is generated, and perform an operation in accordance with the operation of the pilot valve when the pressure difference is larger than that value.

[0006] However, the fact that the main valve is closed by the biasing mechanism can result in relatively large flow resistance at low flow rates and low pressures, and can cause oscillation phenomena due to the natural frequencies of the biasing mechanism and the main valve. In other words, the main valve is structured to open only when fluid flows through the pilot flow path, and when it opens, a large amount of fluid flows into the main valve, reducing the flow rate of the pilot valve, and consequently, the flow rate of the main valve also decreases. Then, when the main valve closes, the flow rate of the pilot valve recovers, and the main valve opens again, creating an oscillation mode. If such a pilot-operated poppet valve is used as a buffer, it may also affect the damping force generated by the buffer.

[0007] The present invention aims to provide a technology that allows the main valve to remain open during the opening operation of a pilot-operated poppet valve.

[0008] As a result of diligent research, the inventors of the present invention have found that by making the opening operation of the main valve dependent on the biasing force of the biasing means and independent of the presence or absence of oil flow from the pilot valve side, the main valve can be kept open during the opening operation of a pilot-operated poppet valve. The present invention was completed based on this finding.

[0009] The present disclosure is described below. The present disclosure provides a pilot-operated poppet valve comprising a main valve and a pilot valve, the pilot-operated poppet valve comprising a biasing means for biasing the main valve in an opening direction and a drive unit capable of pushing both the main valve and the pilot valve in a closing direction.

[0010] According to the present invention, it is possible to provide a technology that allows the main valve to remain open when a pilot-operated poppet valve is opened.

[0011] This is a cross-sectional side view of a part of a buffer equipped with a pilot-operated poppet valve according to an embodiment. This is an enlarged view of part 2 of Figure 1. This is an enlarged view of part 3 of Figure 2. This is an enlarged view of the valve device shown in Figure 3. This is an exploded view of the valve device shown in Figure 4. This is an explanatory diagram of the main valve of the valve device shown in Figure 4 in a closed state. This is a schematic diagram explaining the relationship between the valve seat and valve body shown in Figure 6. This is a schematic diagram of a check valve provided in the pilot valve shown in Figure 4. This is a schematic diagram explaining the relationship between the area of ​​the main pressure-receiving surface and the area of ​​the pilot pressure-receiving surface of the valve body shown in Figure 6.

[0012] Embodiments of the present invention will be described below with reference to the attached drawings. The embodiments shown in the attached drawings are examples of the present invention, and the present invention is not limited to these embodiments.

[0013] <Example> Figure 1 shows a telescopic shock absorber 10, which constitutes the main part of the front fork. The front fork is installed at the front of a saddle-type vehicle such as a motorcycle and suppresses the transmission of vibrations from the road surface to the vehicle body. The shock absorber 10 mainly consists of a cylindrical outer tube 11 extending downward from the head pipe of the motorcycle toward the front wheel, a cylindrical inner tube 12 extending upward from the front wheel toward the head pipe with its tip inserted into the outer tube 11, and a coil spring (not shown) that biases the outer tube 11 and the inner tube 12 toward each other. The space enclosed by the outer tube 11 and the inner tube 12 is filled with oil as a working fluid. This shock absorber 10 has an outer tube cover portion 13 that closes the upper end (end) of the outer tube 11 and an axle holder 14 that closes the lower end (end) of the inner tube 12.

[0014] As shown in Figures 1 and 2, a pressure accumulator 15 is provided adjacent to the lower part of the inner tube 12, into which excess oil from the inner tube 12 can flow. Between the inner tube 12 and the pressure accumulator 15, a pilot-operated poppet valve 20 is provided to open and close the oil flow path from the inner tube 12 to the pressure accumulator 15. The flow path is the part that connects the inside of the pilot-operated poppet valve 20, the inside of the inner tube 12, and the pressure accumulator 15. The axle holder 14 has a substantially bottomed cylindrical housing section 16. The pilot-operated poppet valve 20 is housed in and detachably mounted in this housing section 16.

[0015] Furthermore, a bladder or free piston can be used in the pressure accumulator 15. In addition, the pressure accumulator 15 only needs to be able to store excess oil in the inner tube 12, and can be used with something other than a bladder or free piston. The pressure accumulator 15 may also be located on the axis of the inner tube 12.

[0016] <Pilot-operated poppet valve 20> As shown in Figure 3, the pilot-operated poppet valve 20 is an automatic valve configuration in which the valve device 40 is driven by a drive unit 30 that operates when an electric current is supplied.

[0017] <Drive Unit 30> The drive unit 30 (actuator 30) is preferably composed of an electromagnetic solenoid equipped with an operating rod 31. This drive unit 30 may be referred to as the "electromagnetic solenoid 30" as appropriate. This electromagnetic solenoid 30 advances the plunger 33 by exciting the excitation coil 32. The operating rod 31 can move back and forth together with the plunger 33 in a direction along the center line CL of the operating rod 31. The excitation coil 32 and the plunger 33 are housed in a cylindrical drive housing 34. One end of this drive housing 34 (the end on the valve device 40 side) is closed by a lid 35. The operating rod 31 passes through the lid 35.

[0018] The end face 35a of the lid 35 that faces the valve device 40 is called the "valve-side end face 35a". An annular projection 36 is formed on the valve-side end face 35a, projecting toward the valve device 40. This projection 36 is located near the outer edge of the lid 35 with respect to the center line CL of the operating rod 31. The valve-side end face 35a and the tip surface 36a of the projection 36 are flat surfaces perpendicular to the center line CL.

[0019] <Valve Device 40> As shown in Figures 4 and 5, the valve device 40 is provided at one end 34a of the drive housing 34. This valve device 40 comprises a valve housing 50 and a main valve 80 and a pilot valve 110 housed in the valve housing 50. The valve housing 50, the main valve 80 and the pilot valve 110 are located on the centerline CL of the operating rod 31. The centerline CL of the operating rod 31 may be appropriately referred to as "the centerline CL of the main valve 80 or the centerline CL of the pilot valve 110".

[0020] <Valve Housing 50> The valve housing 50 comprises a first housing portion 60 provided inside one end 34a of the drive housing 34 of the drive unit 30, and a second housing portion 70 provided in the first housing portion 60.

[0021] The first housing portion 60 is a cylindrical member with respect to the center line CL of the operating rod 31, and one end face 61 (upper end face 61) on the lid 35 side overlaps the tip face 36a of the protruding portion 36 of the lid 35. The interior of this first housing portion 60 is divided into a first chamber 63 and a second chamber 64 in the direction along the center line CL by an annular partition plate 62. The first chamber 63 is the space on the side of the partition plate 62 to one end face 61, and the second chamber 64 is the space on the side of the partition plate 62 to the other end face 65 (lower end face 65). As shown in Figure 5, the diameter d1 of the first chamber 63 is larger than the inner diameter d2 of the partition plate 62 and smaller than the diameter d3 of the second chamber 64 (d2 < d1 < d3).

[0022] The partition plate 62 is integrally formed with the first housing portion 60. The surface 62a of the partition plate 62 facing the first chamber 63 (first section screen 62a) is preferably a tapered surface that narrows toward the second chamber 64. The surface 62b of the partition plate 62 facing the second chamber 64 (second section screen 62b) is a flat surface perpendicular to the center line CL. Furthermore, the first housing portion 60 has at least one oil passage hole 66 that penetrates radially through the first chamber 63. This oil passage hole 66 is located near the first section screen 62a.

[0023] The second housing portion 70 is a disc-shaped bottom member with respect to the center line CL of the operating rod 31, and a portion of it is fitted into the second chamber 64 of the first housing portion 60. Furthermore, one end surface 71 of the second housing portion 70 (the surface 71 on the partition plate 62 side) is formed as a flat surface that abuts against the second section screen 62b of the partition plate 62. In this way, the second housing portion 70 constitutes a bottom member that closes the first chamber 63 of the first housing portion 60.

[0024] The second housing portion 70 has a single main passage 72 located on the centerline CL of the operating rod 31, and at least one sub-passage 73 located around the main passage 72. The main passage 72 and the sub-passage 73 penetrate the second housing portion 70 in a direction along the centerline CL. On the side 71 of the second housing portion 70 facing the partition plate 62, a valve seat receiving portion 74 consisting of a recess located on the centerline CL and a bottomed cylindrical spring receiving portion 75 rising from the center of the bottom surface 74a of the valve seat receiving portion 74 are formed. The valve seat receiving portion 74 is formed in an arc shape with respect to the centerline CL. Inside the spring receiving portion 75, a flat bottom surface 75a (spring receiving surface 75a) is formed with respect to the centerline CL. The main passage 72 penetrates the spring receiving surface 75a. The sub-passage 73 penetrates the valve seat receiving portion 74.

[0025] <Main Valve 80> The main valve 80 is openable and closable in a direction along the centerline CL of the operating rod 31 (axis line CL of the main valve 80), and comprises a valve seat 90 and a valve body 100 that can seat on the valve seat 90 and be closed. The valve seat 90 is an annular member with respect to the axis line CL of the main valve 80, and is mounted between the partition plate 62 and the valve seat receiving portion 74 of the second housing portion 70.

[0026] The inner diameter d4 of the valve seat 90 is smaller than the inner diameter d2 of the partition plate 62. Therefore, the valve seat 90 has a surface 90a that is exposed radially inward from the partition plate 62. This exposed surface 90a is sometimes called the "seat surface 90a". The valve seat 90 is composed of a composite of, for example, a sheet-like sealing member 91 that abuts against the partition plate 62, a metal flat washer 92 superimposed on the back surface of the sealing member 91, and a metal disc washer 93 superimposed on the back surface of the flat washer 92. The disc washer 93 biases the sealing member 91 to press against the partition plate 62 via the flat washer 92. The presence or absence of the flat washer 92 is optional.

[0027] The valve body 100 is housed in the first chamber 63 of the first housing portion 60 and is supported on the inner circumferential surface 67 of the first housing portion 60 (the surface 67 forming the first chamber 63) so as to be movable along the axis CL of the main valve 80. The valve body 100 is a bottomed cylindrical member with the lid 35 side open, and comprises a cylindrical tube portion 101 and a bottom plate 102 at one end of the tube portion 101. The tube portion 101 has a large diameter tube portion 103 on the lid 35 side, a small diameter tube portion 104 on the second housing portion 70 side, and a stepped portion 105 connecting the large diameter tube portion 103 and the small diameter tube portion 104. The outer diameter d5 of the small diameter tube portion 104 is smaller than the inner diameter d2 of the partition plate 62 and larger than the inner diameter d4 of the valve seat 90 (d2 < d5 < d4). The stepped portion 105 has a stepped surface 105a facing the large-diameter cylindrical portion 103. This stepped surface 105a is sometimes referred to as the "first contact surface 105a" or the "first contact portion 105a".

[0028] The valve body 100 has a main pressure-receiving surface 102a on the outside of the bottom plate 102, a pilot pressure-receiving surface 102b on the inside of the bottom plate 102, and a first communication passage 106 that penetrates the bottom plate 102 both internally and externally. The first communication passage 106 connects (is in communication with) the main pressure-receiving surface 102a and the pilot pressure-receiving surface 102b.

[0029] The main pressure-receiving surface 102a receives hydraulic pressure in the opening direction Ra (direction of arrow Ra) when seated on the valve seat 90, as shown in Figure 6. This main pressure-receiving surface 102a is a flat surface perpendicular to the axis CL of the main valve 80 and faces one end face 71 (the face 71 on the partition plate 62 side) of the second housing portion 70. This main pressure-receiving surface 102a is biased by a biasing means 107 in the direction away from the valve seat 90 Ra (direction of arrow Ra), that is, in the direction Ra that opens the main valve 80. This biasing means 107 is made up of a compression coil spring and is provided inside a spring receiving portion 75 formed in the second housing portion 70.

[0030] The pilot pressure receiving surface 102b receives hydraulic pressure in the closing direction Rb (direction of arrow Rb), as shown in Figure 5. This pilot pressure receiving surface 102b is a surface perpendicular to the axis CL of the main valve 80 and is located on the side of the bottom plate 102 opposite to the main pressure receiving surface 102a.

[0031] As shown in Figure 7, the valve seat 90 of the main valve 80 also functions as a check valve 95 (first check valve 95) that allows oil to flow from the direction Rb in which the valve body 100 is seated. In this valve seat 90, the disc washer 93 biases the sealing member 91 in a direction that presses it against the partition plate 62. The main valve 80 is closed when the valve body 100 is seated on the valve seat 90. In this closed state, if hydraulic pressure exceeding the biasing force of the disc washer 93 acts on the sealing member 91 from the first chamber 63 side (from the direction Rb in which the valve body 100 is seated), the sealing member 91 elastically deforms, allowing oil to flow from the first chamber 63 to the main passage 72 and the sub-passage 73.

[0032] The valve seat 90, which also functions as a check valve 95, is configured in an annular shape. When the valve body 100 is separated from the valve seat 90 (when the main valve 80 is open), oil flows from the sub-passage 73 through the center of the valve seat 90 to the first chamber 63. When the valve body 100 is seated on the valve seat 90 (when the main valve 80 is closed), no oil flows. Subsequently, when the hydraulic pressure in the first chamber 63 increases and the sealing member 91 undergoes elastic deformation, it allows oil to flow from the first chamber 63 to the sub-passage 73 (backflow).

[0033] <Pilot Valve 110> As shown in Figures 4 and 5, the pilot valve 110 includes a pilot plunger 120 positioned on the axis CL of the main valve 80 and movable along the axis CL, and a pilot pressure receiving surface 102b formed on the bottom plate 102 of the valve body 100 of the main valve 80. The pilot plunger 120 is inserted inside the valve body 100 of the main valve 80 and supported by the valve body 100. The pilot plunger 120 is relatively movable with respect to the valve body 100 of the main valve 80 along the axis CL of the main valve 80. The pilot plunger 120 will be described in detail below.

[0034] The pilot plunger 120 is a cylindrical member. The pilot plunger 120 comprises a large-diameter first plunger cylinder portion 121 on the lid 35 side, a small-diameter second plunger cylinder portion 122 on the second housing portion 70 side, and a stepped partition portion 123 that separates the first plunger cylinder portion 121 and the second plunger cylinder portion 122. The outer circumferential surface 121a of the first plunger cylinder portion 121 is fitted into the inner circumferential surface 103a of the large-diameter cylinder portion 103, thereby supporting the first plunger cylinder portion 121 so as to be relatively movable along the axis CL of the main valve 80. The space between the inner circumferential surface 103a of the large-diameter cylinder portion 103 and the outer circumferential surface 121a of the first plunger cylinder portion 121 is liquid-tightly sealed by a sealing member 124. The second housing portion 70 is fitted with a gap between it and the inner circumferential surface 104a of the small-diameter cylindrical portion 104.

[0035] The outer circumferential surface 121a of the first plunger cylinder portion 121 and the outer surface 123a of the partition portion 123 are referred to as the "second contact portion 123a". When the second contact portion 123a contacts the first contact portion 105a of the valve body 100, the pilot plunger 120 is restricted from moving toward the pilot pressure receiving surface 102b relative to the valve body 100. This restricted position P1 (lowered position P1) of the pilot plunger 120 is referred to as the "first restricting position P1". When the second contact portion 123a is in the first restricting position P1 relative to the valve body 100, the open end surface 121b of the first plunger cylinder portion 121 protrudes toward the lid 35 side than the open end 103b of the large diameter cylinder portion 103, and the tip surface 122a of the second plunger cylinder portion 122 is separated from the pilot pressure receiving surface 102b. When the open end face 121b of the first plunger cylinder portion 121 is in contact with the valve-side end face 35a of the lid 35, the raised position P2 (second restricting position P2) of the pilot plunger 120 relative to the valve-side end face 35a is defined.

[0036] As described above, the space between the inner circumferential surface 103a of the large-diameter cylindrical portion 103 and the outer circumferential surface 121a of the first plunger cylindrical portion 121 is sealed by the sealing member 124. Between the valve body 100 of the main valve 80 and the pilot plunger 120 housed in the valve body 100, a space 125 is formed, extending from the pilot pressure receiving surface 102b to the sealing member 124. This space 125 is sometimes called the "pilot chamber 125". Thus, the pilot plunger 120, together with the pilot pressure receiving surface 102b, forms the pilot chamber 125.

[0037] Referring also to Figure 8, the pilot chamber 125 is connected to the first communication passage 106 via a check valve 130 (second check valve 130). This check valve 130 allows oil to flow from the first communication passage 106 into the pilot chamber 125 and restricts oil flow from the pilot chamber 125 to the first communication passage 106. For example, this check valve 130 includes a flat plate-shaped check valve body 131 that can move toward and away from the pilot pressure receiving surface 102b, and a biasing member 132 that biases the check valve body 131 toward the pilot pressure receiving surface 102b. This biasing member 132 is made of a compression coil spring and is provided inside the second plunger cylindrical portion 122.

[0038] As shown in Figures 4 and 5, a pilot seal 141 is located in the space 126 enclosed by the first plunger cylinder portion 121 and the partition portion 123. The space 126 in which the pilot seal 141 is located is sometimes referred to as the "pilot seal housing portion 126". Preferably, the end face 121b of the first plunger cylinder portion 121 has a notch 121c through which oil can pass from the pilot seal housing portion 126 into the valve housing 50. This pilot seal 141 is movable within the pilot seal housing portion 126 along the axis CL of the main valve 80.

[0039] The pilot seal housing 126 and the pilot chamber 125 are separated by a partition 123. This partition 123 has a second communication passage 127 that connects the pilot seal housing 126 and the pilot chamber 125. In other words, the pilot plunger 120 has a second communication passage 127 that connects the pilot chamber 125 and the pilot seal housing 126 (i.e., the outside 126 of the pilot chamber 125). This second communication passage 127 is opened and closed by a pilot seal 141 that is movable along the axis CL of the main valve 80.

[0040] The pilot seal 141 described above is guided by the seal holder 142 so as to be movable along the axis CL within the pilot seal housing 126. The drive unit 30 is activated when power is supplied, and the actuation rod 31 pushes the pilot seal 141 via the seal holder 142. In other words, the drive unit 30 pushes the pilot seal 141 in the direction of closing the second communication passage 127 and generates a driving force that pushes the main valve 80 in the direction of closing via the pilot seal 141 and the pilot plunger 120.

[0041] Figure 9A shows the concept of the valve body 100 seated on the valve seat 90 (main valve 80 closed). Figure 9B shows the main pressure-receiving surface 102a of the valve body 100 in the state of the main valve 80 shown in Figure 9A. In the state of the valve body 100 seated on the valve seat 90 (main valve 80 closed), the inner diameter of the valve seat 90 of the main valve 80 is d4, so the area of ​​the main pressure-receiving surface 102a (pressure-receiving area) is A1. Figure 9C shows the pilot pressure-receiving surface 102b of the valve body 100 in the state of the main valve 80 shown in Figure 9A. The inner diameter of the large-diameter cylindrical portion 103 of the valve body 100 is d6, so the area of ​​the pilot pressure-receiving surface 102b (pressure-receiving area) is A2. The inner diameter d6 of the large-diameter cylindrical portion 103 is larger than the inner diameter d4 of the valve seat 90. Therefore, the area A2 of the pilot pressure-receiving surface 102b (pressure-receiving area A2) is larger than the area A1 of the main pressure-receiving surface 102a (pressure-receiving area A1). By utilizing the difference between the pressure-receiving areas A1 and A2, the closing force (closing force) of the main valve 80 can be increased.

[0042] Next, the opening and closing operation of the pilot-type poppet valve 20 will be described with reference to FIGS. 4 and 6. FIGS. 2 and 4 show the pilot-type poppet valve 20 in a state where the drive unit 30 is not energized. The actuating rod 31 of the drive unit 30 does not press the pilot seal 141 in the direction Rb that closes the second communication passage 127. The valve body 100 of the main valve 80 receives the biasing force of the biasing means 107 and is separated from the valve seat 90. Therefore, the main valve 80 is in an open state. The oil that has flowed in from the main passage 72 and the auxiliary passage 73 flows through the oil passage hole 66 to the pressure accumulation chamber 15 (see FIG. 2). Further, the oil that has flowed in from the main passage 72 and the auxiliary passage 73 flows to the first communication passage 106 and opens the check valve 130 (second check valve 130) by hydraulic pressure. Therefore, the oil passes through the second communication passage 127 and the pilot seal storage portion 126, passes through the gap (flow path) between the inner peripheral surface of the first housing portion 60 and the outer peripheral surface of the valve body 100, and flows from the oil passage hole 66 to the pressure accumulation chamber 15 (see FIG. 2).

[0043] Thereafter, when the drive unit 30 is energized, the actuating rod 31 presses the pilot seal 141 in the direction Rb that closes the second communication passage 127. This state is shown in FIG. 6. The pilot seal 141 closes the second communication passage 127 and presses the valve body 100 in the closing direction Rb via the pilot plunger 120. The valve body 100 moves against the biasing force of the biasing means 107 and is seated on the valve seat 90. As a result, the main valve 80 closes, so the oil that has flowed in from the main passage 72 and the auxiliary passage 73 does not flow to the oil passage hole 66.

[0044] A summary of the pilot-type poppet valve 20 described above and the shock absorber 10 including the pilot-type poppet valve 20 is as follows.

[0045] Refer to FIG. 3. According to the present embodiment, firstly, the pilot-type poppet valve 20 includes a main valve 80 and a pilot valve 110, and the pilot-type poppet valve 20 includes: biasing means 107 that biases the main valve 80 in the opening direction Ra; and a drive unit 30 capable of pressing both the main valve 80 and the pilot valve 110 in the closing direction Rb.

[0046] The pilot-type poppet valve 20 coaxially arranges a drive unit 30, a main valve 80, a pilot valve 110, and a biasing means 107. The advancing / retreating direction of the drive unit 30, the opening / closing operation direction of the main valve 80, the opening / closing operation direction of the pilot valve 110, and the biasing direction of the biasing means 107 are the same direction. The opening operation of the main valve 80 depends on the biasing force of the biasing means 107, and does not depend on the presence or absence of oil flow from the pilot valve 110 side. When no pressing force is generated by the drive unit 30, there is no force to close the main valve 80, so the main valve 80 always maintains an open state. Accordingly, an oscillation mode that opens and closes the main valve 80 does not occur, so the flow rate flowing through the main valve 80 is stabilized. For example, in a configuration where the pilot-type poppet valve 20 of the present invention is provided in a shock absorber 10, the operation of the shock absorber 10 can be made smoother. Moreover, since the main valve 80 and the pilot valve 110 are coaxially arranged, both the main valve 80 and the pilot valve 110 can be closed simultaneously by the unidirectional thrust of the drive unit 30.

[0047] Reference is made to FIG. 4 and FIG. 9. Second, preferably, in the pilot-type poppet valve 20 according to the first aspect, the main valve 80 includes a valve seat 90 and a valve body 100 that can be seated on the valve seat 90 to close. The valve body 100 includes: a main pressure-receiving surface 102a that receives hydraulic pressure in an opening direction Ra when seated on the valve seat 90; a pilot pressure-receiving surface 102b that is provided on the opposite side of the main pressure-receiving surface 102a and receives hydraulic pressure in a closing direction Rb; and a first communication passage 106 connecting the main pressure-receiving surface 102a and the pilot pressure-receiving surface 102b. An area A2 (pressure-receiving area A2) of the pilot pressure-receiving surface 102b is larger than an area A1 (pressure-receiving area A1) of the main pressure-receiving surface 102a.

[0048] For this reason, the closing force (closure force) of the main valve 80 can be increased only by setting the area A2 of the pilot pressure-receiving surface 102b to be larger than the area A1 of the main pressure-receiving surface 102a. Utilizing the difference between the pressure-receiving areas A1 and A2, the closing operation of the main valve 80 can be reliably performed, and the closed state of the main valve 80 can be reliably maintained.

[0049] Refer to Figure 4. Thirdly, preferably, the pilot-operated poppet valve 20 as described in the second, wherein the pilot valve 110 includes a pilot plunger 120 positioned on the axis CL of the main valve 80 and movable along the axis CL, and together with the pilot pressure receiving surface 102b, forming a pilot chamber 125, and a second communication passage 127 provided on the pilot plunger 120 that connects the pilot chamber 125 to the outside of the pilot chamber 125. The second communication passage 127 is opened and closed by a pilot seal 141 that is movable along the axis CL.

[0050] Therefore, by opening and closing the second communication passage 127 with the pilot seal 141, the hydraulic pressure in the pilot chamber 125 can be easily controlled to open and close.

[0051] Refer to Figures 3 and 4. Fourth, preferably, the pilot-operated poppet valve 20 as described in the third, wherein the drive unit 30 is a single drive device that operates when energized to push the pilot seal 141 in the direction Rb that closes the second communication passage 127, and generates a driving force that pushes the main valve 80 in the direction Rb that closes the main valve 80 via the pilot seal 141 and the pilot plunger 120.

[0052] Therefore, both the pilot valve 110 and the main valve 80 can be closed by a single drive unit 30. Moreover, by adjusting the driving force of the drive unit 30, the cracking pressure of both the pilot valve 110 and the main valve 80 can be adjusted.

[0053] Refer to Figure 4. Fifth, preferably, the pilot-operated poppet valve 20 as described in the third, wherein the pilot plunger 120 is inserted inside the valve body 100 of the main valve 80 and is supported by the valve body 100.

[0054] In this manner, the pilot plunger 120 is positioned inside the valve body 100 of the main valve 80 and is supported by the valve body 100. Since no separate component is required to support the pilot plunger 120, the configuration of the pilot-operated poppet valve 20 can be simplified and miniaturized.

[0055] Refer to Figure 4. Sixth, preferably, the pilot-operated poppet valve 20 as described in fifth, wherein the pilot plunger 120 is movable relative to the valve body 100 of the main valve 80.

[0056] Therefore, since the pilot plunger 120 moves relative to the valve body 100, the pilot chamber 125 formed between the valve body 100 and the pilot plunger 120 can be easily secured, and the area A1 of the main pressure receiving surface 102a that receives hydraulic pressure in the opening direction when seated on the valve seat 90 can be easily secured.

[0057] Refer to Figure 8. Seventh, preferably, the pilot-operated poppet valve 20 as described in the third, further comprising a check valve 130 (second check valve 130) that allows the flow of oil from the first communication passage 106 into the pilot chamber 125 and restricts the flow of oil from the pilot chamber 125 to the first communication passage 106.

[0058] Therefore, by blocking the oil flowing from the pilot chamber 125 to the first communication passage 106 with the check valve 130, the ability to reliably maintain the hydraulic pressure in the pilot chamber 125 can be improved. Consequently, the operation of the main valve 80 can be made more stable.

[0059] Refer to Figure 7. Eighth, preferably, the pilot-operated poppet valve 20 as described in the second, wherein the valve seat 90 has a check valve 95 (first check valve 95) that allows oil to flow from the direction Rb in which the valve body 100 is seated. Therefore, even when the main valve 80 is closed, it is possible to ensure oil flow (reverse flow) from the direction Rb in which the valve body 100 is seated.

[0060] Refer to Figure 1. Ninth, preferably, is a buffer 10 equipped with the pilot-operated poppet valve 20 described in the first. The pilot-operated poppet valve 20 does not generate an oscillation mode that opens and closes the main valve 80, so the flow rate through the main valve 80 is stable. Therefore, this buffer 10 equipped with the pilot-operated poppet valve 20 can prevent the occurrence of attenuation unintended by the user and can operate more smoothly.

[0061] Refer to Figure 2. Tenth, preferably, the buffer 10 as described in ninth, wherein the buffer 10 further has a pressure accumulator chamber 15 capable of storing oil. The flow path 66 (oil passage hole 66) of the pilot-operated poppet valve 20 is in communication with the pressure accumulator chamber 15. Therefore, the flow of oil to the pressure accumulator chamber 15 can be appropriately controlled by the pilot-operated poppet valve 20.

[0062] Furthermore, the pilot-operated poppet valve 20 and the buffer 10 equipped with this pilot-operated poppet valve 20 according to the present invention are not limited to the above embodiments, as long as they perform the functions and effects of the present invention.

[0063] The pilot-operated poppet valve 20 of the present invention and the shock absorber 10 equipped with this pilot-operated poppet valve 20 are suitable for installation in saddle-type vehicles.

[0064] 10... buffer, 15... accumulator chamber, 20... pilot-operated poppet valve, 30... drive unit, 80... main valve, 90... valve seat, 95... check valve (first check valve), 100... valve body, 102a... main pressure receiving surface, 102b... pilot pressure receiving surface, 106... first communication passage, 107... biasing means, 110... pilot valve, 120... pilot plunger, 125... pilot chamber, 127... second communication passage, 130... check valve (second check valve), 132... biasing member, 141... pilot seal, A1... area of ​​main pressure receiving surface, A2... area of ​​pilot pressure receiving surface, CL... axis of the main valve, Ra... direction to open the main valve, Rb... direction to close the main valve and pilot valve (direction in which the valve body is seated).

Claims

1. A pilot-operated poppet valve comprising a main valve and a pilot valve, the pilot-operated poppet valve comprising: a biasing means for biasing the main valve in the opening direction; and a drive unit capable of pushing both the main valve and the pilot valve in the closing direction.

2. The pilot-operated poppet valve according to claim 1, wherein the main valve comprises a valve seat and a valve body that can seat on the valve seat and close, the valve body having a main pressure receiving surface that receives hydraulic pressure in the opening direction when seated on the valve seat, a pilot pressure receiving surface provided on the opposite side of the main pressure receiving surface and receiving hydraulic pressure in the closing direction, and a first connecting passage that connects the main pressure receiving surface and the pilot pressure receiving surface, the area of ​​the pilot pressure receiving surface being larger than the area of ​​the main pressure receiving surface.

3. The pilot valve comprises a pilot plunger positioned on the axis of the main valve and movable along the axis, and together with the pilot pressure receiving surface, forming a pilot chamber; and a second communication passage provided in the pilot plunger, which connects the pilot chamber to the outside of the pilot chamber, wherein the second communication passage is opened and closed by a pilot seal movable along the axis, as described in claim 2.

4. The pilot-operated poppet valve according to claim 3, wherein the drive unit is a single drive device that operates when energized, pushing the pilot seal in a direction that closes the second communication passage, and generating a driving force that pushes the main valve in a direction that closes via the pilot seal and the pilot plunger.

5. The pilot-operated poppet valve according to claim 3, wherein the pilot plunger is inserted inside the valve body of the main valve and is supported by the valve body.

6. The pilot plunger is movable relative to the valve body of the main valve, the pilot-operated poppet valve according to claim 5.

7. The pilot-operated poppet valve according to claim 3, further comprising a check valve that allows the flow of oil from the first communication passage into the pilot chamber and restricts the flow of oil from the pilot chamber to the first communication passage.

8. The pilot-operated poppet valve according to claim 2, wherein the valve seat has a check valve that allows oil to flow in the direction in which the valve body is seated.

9. A buffer equipped with a pilot-operated poppet valve according to claim 1.

10. The buffer according to claim 9, further comprising a pressure storage chamber capable of storing oil, wherein the flow path of the pilot-operated poppet valve is in communication with the pressure storage chamber.

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