JP2022036582A - Buffer - Google Patents

Abstract

To provide a buffer capable of preventing a valve body from falling out of a piston bolt in assembly.SOLUTION: Since a claw part 155 of a disc 151 is abutted against a counterbore part 112 of a piston bolt 5, during assembly, even when a head 7 of the piston bolt 5 is turned downward from the time when a valve spool 82 (valve body) is inserted into a common passage 11 of the piston bolt 5 until a solenoid 91 is connected to the piston bolt 5, a flange part 141 of the valve spool 82 is received by an inner peripheral edge part 154 of the disc 151, so that it is possible to prevent the valve spool 82 from falling out of the common passage 11.SELECTED DRAWING: Figure 3

Description

The present invention relates to a damping force adjusting shock absorber that controls the flow of oil and liquid with respect to the stroke of the piston rod to adjust the damping force.

Patent Document 1 discloses a shock absorber having a damping force adjusting mechanism built in a cylinder. In this shock absorber, a spool-shaped valve body is inserted into a common passage formed in the piston bolt, and the damping force can be adjusted by controlling the valve opening pressure of the valve body using a solenoid (actuator). ..

International Publication No. 2018/135461

The shock absorber described in Patent Document 1 has a valve on the shaft portion of a piston bolt, for example, from the time when the valve body is inserted into the common passage of the piston bolt to the time when the solenoid is connected to the piston bolt at the time of assembly. If the head of the piston bolt is turned downward when assembling the parts, the valve body will fall out of the common passage, and it is necessary to hold down the valve body, which causes a decrease in assembling property.

An object of the present invention is to provide a shock absorber that prevents a valve body from coming off from a piston bolt during assembly.

The shock absorber of the present invention has a cylinder in which a working fluid is sealed, a piston that is slidably fitted in the cylinder and divides the inside of the cylinder into a cylinder one side chamber and a cylinder other side chamber, and one end of the piston. A piston rod whose other end extends outward from the cylinder, an extension side passage and a contraction side passage provided in the piston, an extension side main valve provided in the extension side passage, and an extension side main valve. An extension side back pressure chamber that adjusts the valve opening pressure of the valve, a contraction side main valve provided in the contraction side passage, a contraction side back pressure chamber that adjusts the valve opening pressure of the contraction side main valve, and the extension side. It controls the flow of oil and liquid in the common passage that communicates the back pressure chamber and the contraction side back pressure chamber, the piston bolt that is inserted into the shaft hole of the piston to form the common passage, and the common passage. A piston valve is provided, and the pilot valve includes a valve body provided in the common passage and whose movement is controlled by an actuator, and an urging member for urging the valve body in the valve opening direction. A regulating member for restricting the axial movement of the valve body is provided between the valve body and the piston bolt.

According to the present invention, it is possible to prevent the valve body from coming off from the piston bolt when the shock absorber is assembled.

It is sectional drawing of the damping force adjusting mechanism part in the shock absorber of 1st Embodiment. It is an enlarged view of the main part in FIG. It is explanatory drawing of 1st Embodiment. It is a top view of a disk (regulatory member). It is explanatory drawing of 2nd Embodiment. It is explanatory drawing of the 3rd Embodiment.

(First Embodiment)
The first embodiment of the present invention will be described with reference to the attached figure.
For convenience, the vertical direction in FIG. 1 is referred to as "vertical direction" as it is. Hereinafter, the single-cylinder type damping force-adjustable shock absorber will be described, but the first embodiment can also be applied to a double-cylinder type damping force-adjustable shock absorber provided with a reservoir.

As shown in FIG. 1, the shock absorber 1 is a damping force adjusting type shock absorber having a damping force adjusting mechanism built in the cylinder 2. A piston 3 is slidably fitted in the cylinder 2. The piston 3 divides the inside of the cylinder 2 into two chambers, a cylinder upper chamber 2A (one side chamber) and a cylinder lower chamber 2B (other side chamber). A free piston (not shown) that can move vertically in the cylinder 2 is provided in the cylinder 2, and the free piston has a cylinder lower chamber 2B and a bottom on the piston 3 side (upper side) in the cylinder 2. It is divided into a gas chamber (not shown) on the side (lower side).

The shaft portion 6 of the piston bolt 5 is inserted into the shaft hole 4 of the piston 3. The piston bolt 5 has a head portion 7 provided at the upper end portion of the shaft portion 6 and a cylindrical portion 8 formed on the outer peripheral edge portion of the head portion 7. The cylindrical portion 8 has an opening on the upper end side and has a large outer diameter with respect to the head portion 7. The lower end of the solenoid case 94 is connected to the cylindrical portion 8 by screw coupling. The piston bolt 5 is provided with a common passage 11 coaxial with the shaft portion 6.

As shown in FIG. 2, the common passage 11 is an axial passage 12 formed in the upper part of the common passage 11 and opened at the upper end, and an axial passage formed in the lower part of the common passage 11 and closed at the lower end. It is composed of 14 and an axial passage 13 communicating between the axial passages 12 and 14. The inner diameter of the common passage 11 is largest in the axial passage 13, and decreases in the order of the axial passage 12 and the axial passage 14. The axial passage 12 opens at the central bottom surface of the stepped recess 110 formed in the end surface 9 of the head portion 7 of the piston bolt 5. The stepped recess 110 has a circular cross section coaxial with the piston bolt 5 in a plane perpendicular to the axis.

As shown in FIG. 1, the lower end portion (one end) of the piston rod 15 is connected to the upper end portion of the solenoid case 94 by screw coupling. The upper end side (the other end) of the piston rod 15 extends to the outside of the cylinder 2. A nut 16 for preventing loosening is provided at the lower end of the piston rod 15. A small diameter portion 17 is formed at the lower end of the piston rod 15. An annular groove (reference numeral omitted) is formed on the outer peripheral surface of the small diameter portion 17. A sealing member 18 for sealing between the solenoid case 94 and the piston rod 15 is mounted on the annular groove.

The piston 3 is provided with an extension-side passage 19 whose upper end opens into the cylinder upper chamber 2A and a contraction-side passage 20 whose lower end opens into the cylinder lower chamber 2B. On the lower end side of the piston 3, an extension side valve mechanism 21 (damping force adjusting mechanism) for controlling the flow of the oil liquid (working fluid) in the extension side passage 19 is provided. On the other hand, on the upper end side of the piston 3, a contraction side valve mechanism 51 (damping force adjusting mechanism) for controlling the flow of oil liquid in the contraction side passage 20 is provided.

As shown in FIG. 2, the extension-side valve mechanism 21 has an annular seat portion 24 formed on the outer peripheral side of the lower end surface of the piston 3 and an extension-side main valve 23 that abuts on the seat portion 24 so as to be removable and seatable. And an extension side pilot body 25 attached to the shaft portion 6 of the piston bolt 5, and an extension side back pressure chamber 26 formed between the extension side pilot body 25 and the back surface of the extension side main valve 23. .. The pressure in the extension side back pressure chamber 26 acts on the extension side main valve 23 in the valve closing direction.

A nut 27 (see FIG. 1) is attached to the lower end of the shaft portion 6 of the piston bolt 5. A washer 28, a retainer 29, and a disc valve 30 are provided between the nut 27 and the extension side pilot body 25 in this order from the lower side. The washer 28, the retainer 29, and the disc valve 30 are held between the nut 27 and the inner peripheral edge of the extension side pilot body 25. The extension-side main valve 23 is a packing valve in which an annular packing 31 made of an elastic body comes into contact with the inner peripheral surface of the extension-side pilot body 25 over the entire circumference.

The extension-side back pressure chamber 26 communicates with the cylinder lower chamber 2B via a passage 32 and a disc valve 30 formed in the extension-side pilot body 25. The disc valve 30 opens when the pressure in the extension-side back pressure chamber 26 reaches a predetermined pressure, and relieves the pressure in the extension-side back pressure chamber 26 to the cylinder lower chamber 2B. The extension side back pressure chamber 26 communicates with the chamber 49 formed between the extension side pilot body 25 and the disc valve 30 via the passage 32. The chamber 49 is defined by an endless seat portion 50 provided on the lower end surface of the extension side pilot body 25.

The extension-side back pressure chamber 26 communicates with a radial passage 34 formed in the shaft portion 6 of the piston bolt 5 via a disk-shaped extension-side back pressure introduction valve 33. The radial passage 34 communicates with the axial passage 14. The extension side back pressure introduction valve 33 is a check valve that allows the flow of oil liquid from the cylinder lower chamber 2B to the extension side back pressure chamber 26 through the passage 44 of the extension side pilot body 25. The extension side back pressure introduction valve 33 is an annular shape formed on the inner peripheral side of the passage 32 and the outer peripheral side of the passage 44 on the upper surface of the extension side pilot body 25 (the surface on the extension side back pressure chamber 26 side). It is brought into contact with the seat portion 35 so that it can be taken off and seated. The inner peripheral edge portion of the extension side back pressure introduction valve 33 is held between the inner peripheral edge portion of the extension side pilot body 25 and the spacer 36. The extension-side back pressure chamber 26 includes a plurality of extension-side introduction orifices 37 formed on the inner peripheral side of the extension-side back pressure introduction valve 33, and an annular passage 38 formed on the inner peripheral edge of the extension-side pilot body 25. It communicates with the radial passage 34 via.

The axial passage 14 communicates with the radial passage 39 (contraction side discharge passage) formed in the shaft portion 6 of the piston bolt 5. The radial passage 39 is provided in the annular passage 41 formed at the lower end of the shaft hole 4 of the piston 3, the plurality of notches 42 formed on the lower end side of the inner peripheral edge of the piston 3, and the piston 3. It is communicated with the extension side passage 19 via the contraction side check valve 40. The contraction-side check valve 40 comes into contact with the annular seat portion 43 provided on the inner peripheral side of the seat portion 24 and the extension-side passage 19 on the lower end side of the piston 3 so as to be able to take off and sit. The contraction side check valve 40 allows the flow of oil liquid from the radial passage 39 to the extension side passage 19.

The contraction side valve mechanism 51 includes an annular seat portion 54 formed on the outer peripheral side of the upper end surface of the piston 3, a contraction side main valve 53 that abuts on the seat portion 54 so as to be able to take off and sit, and a shaft portion of the piston bolt 5. A contraction-side pilot body 55 attached to 6 and a contraction-side back pressure chamber 56 formed between the contraction-side pilot body 55 and the back surface of the contraction-side main valve 53 are provided. The pressure in the contraction side back pressure chamber 56 acts on the contraction side main valve 53 in the valve closing direction. The contraction side main valve 53 is a packing valve in which an annular packing 61 made of an elastic body comes into contact with the inner peripheral surface of the contraction side pilot body 55 over the entire circumference.

The contraction side back pressure chamber 56 communicates with the cylinder upper chamber 2A via a passage 62 and a disc valve 60 formed in the contraction side pilot body 55. The disc valve 60 opens when the pressure of the contraction side back pressure chamber 56 reaches a predetermined pressure, and relieves the pressure in the contraction side back pressure chamber 56 to the cylinder upper chamber 2A. The contraction-side back pressure chamber 56 communicates with the chamber 79 formed between the contraction-side pilot body 55 and the disc valve 60 via the passage 62. The chamber 79 is defined by an endless seat portion 80 provided on the lower end surface of the contraction side pilot body 55. The contraction-side back pressure chamber 56 communicates with a radial passage 64 formed in the shaft portion 6 of the piston bolt 5 via a disk-shaped contraction-side back pressure introduction valve 63. The radial passage 64 communicates with the axial passage 12.

The contraction side back pressure introduction valve 63 is a check valve that allows the flow of oil liquid from the cylinder upper chamber 2A to the contraction side back pressure chamber 56 through the passage 74 of the contraction side pilot body 55. The contraction-side back pressure introduction valve 63 is an annular shape formed on the inner peripheral side of the passage 62 and on the outer peripheral side of the passage 74 on the lower surface of the contraction-side pilot body 55 (the surface on the contraction-side back pressure chamber 56 side). It abuts on the seat portion 65 so that it can be taken off and seated. The inner peripheral edge portion of the contraction side back pressure introduction valve 63 is held between the inner peripheral edge portion of the contraction side pilot body 55 and the spacer 66. The contraction side back pressure chamber 56 includes a plurality of contraction side introduction orifices 67 formed on the inner peripheral side of the contraction side back pressure introduction valve 63, an annular passage 68 formed on the inner peripheral edge portion of the contraction side pilot body 55, and an annular passage 68. It communicates with the radial passage 64 via the width across flats 75 formed on the shaft portion 6 of the piston bolt 5.

The axial passage 12 communicates with the radial passage 69 (contraction side discharge passage) formed in the shaft portion 6 of the piston bolt 5. The radial passage 69 is provided in the annular passage 71 formed at the upper end of the shaft hole 4 of the piston 3, the plurality of notches 72 formed on the upper end side of the inner peripheral edge of the piston 3, and the piston 3. It is communicated to the contraction side passage 20 via the extension side check valve 70. The extension-side check valve 70 comes into contact with the seat portion 54 on the upper end side of the piston 3 and the annular seat portion 73 provided on the inner peripheral side of the contraction-side passage 20 so as to be able to take off and sit. The extension side check valve 70 allows the flow of oil liquid from the radial passage 69 to the contraction side passage 20.

The flow of oil and liquid in the common passage 11 of the piston bolt 5 is controlled by the pilot valve 81. The pilot valve 81 has a valve spool 82 (valve body) slidably fitted in the common passage 11. The valve spool 82 is composed of a solid shaft, and together with the piston bolt 5, constitutes a pilot valve 81. The valve spool 82 is a valve portion that comes into contact with the sliding portion 83 of the axial passage 12 inserted above the radial passage 64 and the seat portion 84 formed on the peripheral edge of the opening of the axial passage 14 so as to be able to take off and sit. It has an 85 and a connecting portion 86 connecting the sliding portion 83 and the valve portion 85.

A pilot spring 88 made of a compression coil spring is interposed between the spring receiving portion 87 formed in the valve portion 85 of the valve spool 82 and the bottom portion of the common passage 11 (axial passage 14). The pilot spring 88 urges the valve spool 82 upward with respect to the piston bolt 5. As a result, the end surface 89 of the sliding portion 83 comes into contact with (presses) the lower end surface 93 of the operating rod 92 in the solenoid 91 (see FIG. 1) described later.

As shown in FIG. 1, the solenoid 91 (actuator) has a solenoid case 94, an actuating rod 92, and a coil 95. A plunger 96 is coupled to the outer peripheral surface of the operating rod 92. The plunger 96 generates thrust by energizing the coil 95. An in-rod passage 97 is formed on the inner peripheral side of the operating rod 92. The actuating rod 92 is guided in the vertical direction (axial direction) by the bush 100 provided in the core 98.

As shown in FIG. 2, a first chamber 121 is provided inside the stepped recess 110 of the piston bolt 5. The upper end 90 of the valve spool 82 projects from the first chamber 121. In other words, the first chamber 121 is provided on the outer periphery of the upper end 90 (one side of the valve body) of the valve spool 82. On the other hand, a bottomed cylindrical washer 123 (bottomed cylinder member) having an opening on the upper end side is attached to the outer peripheral surface 122 of the head 7 of the piston bolt 5.

The bottom portion 124 of the washer 123 is provided with a bolt insertion hole 125 through which the shaft portion 6 of the piston bolt 5 is inserted. A plurality of notches 129 are provided on the inner peripheral edge of the bottom portion 124. The notch 129 communicates with the width across flats 75 of the shaft 6. An annular groove 127 is provided on the outer peripheral surface 122 of the head portion 7 of the piston bolt 7. The annular groove 127 is provided with a sealing member 128 that seals between the head portion 7 of the piston bolt 5 and the cylindrical portion 126 of the washer 123. As a result, an annular second chamber 131 is formed between the lower end side of the head portion 7 of the piston bolt 5 and the washer 123.

A spool back pressure relief valve 107, a spacer 108, and a retainer 132 are provided between the head portion 7 of the piston bolt 5 and the bottom portion 124 of the washer 123 in this order from the upper side. The spool back pressure relief valve 107, spacer 108, and retainer 132 are provided in the second chamber 131. The spool back pressure relief valve 107 (check valve) is a check valve that allows the flow of oil liquid from the first chamber 121 to the second chamber 131 through the passage 105 formed in the head 7. The inner peripheral edge of the spool back pressure relief valve 107 is held between the inner peripheral edge of the head portion 7 of the piston bolt 5 and the spacer 108. The outer peripheral edge portion of the spool back pressure relief valve 107 abuts on the annular seat portion 109 formed on the lower surface of the head portion 7 of the piston bolt 5 so as to be able to take off and sit.

The inner peripheral edge of the retainer 132 is provided with a plurality of notches 133 that communicate the second chamber 131 with the width across flats 75 and the notch 129 of the washer 123. The retainer 132 has an outer diameter substantially equal to that of the spool back pressure relief valve 107, and adjusts the maximum valve opening amount of the spool back pressure relief valve 107. A disc 58 and a retainer 59 are provided between the bottom portion 124 of the washer 123 and the disc valve 60 in this order from the upper side. The disk 58 cuts off communication between the cylinder upper chamber 2A and the second chamber 131 through the notch 129 of the washer 123.

A fail-safe valve 140 is configured on the head portion 7 of the piston bolt 5. The fail-safe valve 140 closes the flange portion 141 provided at the upper end portion 90 of the valve spool 82, the disc 151 (regulatory member) with which the flange portion 141 comes into contact with each other so as to be able to take off and sit, and the flange portion 141 to close the fail-safe valve 140. It includes a spring disk 145 (a urging member) that urges the valve spool 82 (valve body) in the valve opening direction of the pilot valve 81.

As shown in FIG. 3, the outer peripheral edges 146 and 152 of the spring disk 145 and the disk 151 include the outer peripheral edge portion of the bottom surface 113 of the counterbore portion 112 of the piston bolt 5 and the annular convex portion 135 of the core 99 of the solenoid 91. Retained between. The counterbore portion 112 is formed on the peripheral edge of the opening of the large inner diameter portion 111 of the stepped recess 110 of the head portion 7 of the piston bolt 5. On the other hand, the annular convex portion 135 is formed on the outer peripheral edge portion of the lower end surface 136 of the core 99.

Between the bottom surface 113 of the counterbore portion 112 of the piston bolt 5 and the annular convex portion 135 of the core 99, the outer peripheral edge portion 146 of the spring disk 145, the outer peripheral edge portion 149 of the annular retainer 148, and the annular retainer 148, in this order from the bottom. The outer peripheral edge portion 152 of the disk 151 is interposed. The retainer 148 has an inner diameter smaller than the inner diameter of the large inner diameter portion 111 of the stepped recess 110, adjusts the range of motion of the spring disc 145, and supports the lower surface of the disc 151 on the outer peripheral side.

The inner peripheral edge portion 147 of the spring disk 145 is in contact with the lower end surface 142 (one side in the axial direction) of the flange portion 141. On the other hand, the upper end surface 143 (on the other side in the axial direction) of the flange portion 141 receives the spring force (urging force) of the spring disc 145 in the fail state (the thrust of the solenoid 91 is 0), and the inner peripheral edge portion of the disc 151. It comes into contact with 154, which closes the fail-safe valve 140.

As shown in FIG. 4, the disc 151 is manufactured by press-molding a thin plate (steel plate). The disk 151 is made of a disk having an outer diameter (D1) smaller than the inner diameter of the counterbore portion 112 of the piston bolt 5. The disk 151 has a plurality of (“3” in the first embodiment) claw portions 155 projecting radially outward from the end surface 153 of the outer peripheral edge portion 152. The plurality of claw portions 155 are arranged at equal intervals in the circumferential direction (in the first embodiment, "equally distributed at an angle of 120 degrees"). The material of the disk 151 is not limited to the steel plate, and may be, for example, a polymer material or the like.

As shown in FIG. 3, when the disc 151 is charged (press-fitted) into the counterbore portion 112, the claw portion 155 is pressed against the side surface 114 of the counterbore portion 112 and bends around the end surface 153 of the disc 151 as a fulcrum. As described above, the counterbore portion 112 is elastically deformed so as to be raised upward at an angle of, for example, 30 degrees with respect to the bottom surface 113 of the counterbore portion 112. As a result, in the claw portion 155, the outer corner portion 156 (the ridge of the portion farthest from the center of the disc 151) abuts against the side surface 114 of the counterbore portion 112 in a state where the disc 151 is loaded into the counterbore portion 112. Be (push). When the disc 151 is charged into the counterbore portion 112 and the claw portion 155 forms an angle of 30 degrees with respect to the bottom surface 113 of the counterbore portion 112, the claw portion 155 is set to, for example, 20 degrees during press molding of the disc 151. You can fold it at the angle of.

As shown in FIG. 4, the disk 151 is formed with a notched orifice 157 extending radially inward (toward the center) from the end surface 153 of the outer peripheral edge portion 152. The orifice 157 communicates the annular passage 117 formed on the outer periphery of the annular protrusion 135 of the core 99 with the first chamber 121 of the stepped recess 110 of the piston bolt 5. Thereby, the damping force generated at the time of failing can be appropriately set by adjusting the flow path area of the orifice 157 (the product of the thickness of the disk 151 and the orifice width). A plurality of (“3” in the first embodiment) openings 158 are formed around the shaft hole 159 of the disk 151. The opening 158 is used as a flow path communicating the annular passage 117 and the first chamber 121, and also functions to release the stress due to the elastic deformation of the claw portion 155 inward in the radial direction.

As shown in FIG. 2, an annular groove 115 is provided on the outer peripheral surface of the core 99. A sealing member 116 that seals between the lower end of the solenoid case 94 and the core 99 is mounted on the annular groove 115. As a result, an annular passage 117 is formed between the piston bolt 5, the solenoid case 94, and the core 99. The annular passage 117 communicates with the cylinder upper chamber 2A via a passage 118 provided at the lower end of the cylindrical portion 8 of the piston bolt 5.

A spool back pressure chamber 101 is provided on the inner peripheral side of the core 99 of the solenoid 91. The spool back pressure chamber 101 communicates with the rod back pressure chamber 103 (see FIG. 3) via the notch 102 of the operating rod 92 and the in-rod passage 97. When the coil 95 is not energized, the valve spool 82 is urged upward by the spring force of the spring disc 145, that is, in the direction in which the valve portion 85 is separated from the seat portion 84. As a result, the flange portion 141 is seated on the disk 151, and as a result, the communication between the spool back pressure chamber 101 and the first chamber 121 is cut off.

On the other hand, when the coil 95 is energized, the valve spool 82 is urged downward by the thrust of the operating rod 92 (plunger 96), that is, in the direction in which the valve portion 85 is seated on the seat portion 84. As a result, in the valve spool 82, the valve portion 85 is seated on the seat portion 84 against the spring force of the pilot spring 88 and the fail-safe spring 112. The valve opening pressure of the pilot valve 81 (valve portion 85) is controlled by changing the current value of energization to the coil 95. In the soft mode in which the current value of energization to the coil 95 is small, the spring force of the pilot spring 88 and the thrust of the operating rod 92 are in equilibrium, and the valve portion 85 is separated from the seat portion 84.

Next, the flow of the oil liquid in the first embodiment, mainly the pilot flow, will be described.
(Shrinking process)
Before opening the pilot valve 81 (valve body), the oil liquid in the lower chamber 2B of the cylinder is charged with the contraction side passage 20, the orifice 76 of the extension side check valve 70, the notch 72 of the piston 3, the annular passage 71, and the diameter. Directional passage 69, axial passage 12 (common passage 11), and contraction side introduction passage, that is, radial passage 64, width across flats 75 of shaft portion 6, annular passage 68, and contraction side back pressure introduction valve 63. It is introduced into the contraction side back pressure chamber 56 via the contraction side introduction orifice 67.

When the pilot valve 81 is opened, the oil liquid introduced into the axial passage 12 is introduced into the contraction side back pressure chamber 56 via the contraction side introduction passage, and the contraction side pilot passage, that is, the axial passage 13 ( Cylinder upper chamber 2A via common passage 11), axial passage 14 (common passage 11), radial passage 39, annular passage 41, notch 42 of piston 3, contraction side check valve 40, and extension side passage 19. Flow to. At this time, the valve opening pressure of the pilot valve 81 can be adjusted by controlling the current value of energization of the solenoid 91 (actuator) to the coil 95. At the same time, the pressure of the oil liquid introduced from the contraction side back pressure introduction valve 63 to the contraction side back pressure chamber 56 is also adjusted, so that the valve opening pressure of the contraction side main valve 53 can be controlled.

Further, when the pilot valve 81 is opened, the oil liquid in the first chamber 121 is discharged to the cylinder upper chamber 2A through the notch 120 of the retainer 114, the annular passage 117, and the passage 118 of the piston bolt 5. As a result, volume compensation is performed for the amount of the valve spool 82 protruding into the first chamber 121. At this time, the flow of the oil liquid from the contraction side back pressure chamber 56 to the first chamber 121 is blocked by the spool back pressure relief valve 107 (check valve) provided between the common passage 11 and the first chamber 121. Will be done.

(Stretching process)
Before opening the pilot valve 81, the oil liquid in the cylinder upper chamber 2A is charged with the extension side passage 19, the orifice 48 of the contraction side check valve 40, the notch 42 of the piston 3, the annular passage 41, and the radial passage 39. The extension side back pressure chamber 26 passes through the axial passage 14 (common passage 11) and the extension side introduction passage, that is, the radial passage 34, the annular passage 38, and the extension side introduction orifice 37 of the extension side back pressure introduction valve 33. Will be introduced to.

When the pilot valve 81 is opened, the oil liquid introduced into the axial passage 14 is introduced into the extension side back pressure chamber 26 via the extension side introduction passage, and the extension side pilot passage, that is, the axial passage 13 ( Cylinder lower chamber 2B via common passage 11), axial passage 12 (common passage 11), radial passage 69, annular passage 71, notch 72 of piston 3, extension side check valve 70, and contraction side passage 20. Flow to. At this time, the valve opening pressure of the pilot valve 81 can be adjusted by controlling the current value of energization of the solenoid 91 to the coil 95. At the same time, the pressure of the oil liquid introduced from the extension side back pressure introduction valve 33 to the extension side back pressure chamber 26 is also adjusted, so that the valve opening pressure of the extension side main valve 23 can be controlled.

Further, when the pilot valve 81 is opened, the oil liquid in the first chamber 121 is supplied to the passage 105 of the piston bolt 5, the spool back pressure relief valve 107, the second chamber 131, the notch 133 of the retainer 132, and the piston bolt 5. Via the surface width portion 75, the radial passage 64, the axial passage 12 (common passage 11), the radial passage 69, the annular passage 71 of the piston 3, the notch 72, the extension side check valve 70, and the contraction side passage 20. Then, it is discharged to the lower chamber 2B of the cylinder. As a result, volume compensation is performed for the amount of the valve spool 82 protruding into the first chamber 121.

Here, in the shock absorber described in Patent Document 1 (hereinafter referred to as "conventional shock absorber"), the valve body is inserted into the common passage of the piston bolt at the time of assembly, and then the solenoid is coupled to the piston bolt. For example, if the head of the piston bolt is turned downward when assembling the valve parts to the shaft of the piston bolt, the valve body will fall out of the common passage, so it is necessary to hold down the valve body. It was the cause of the decrease in attachment.

On the other hand, in the first embodiment, the outer peripheral edge portion 146 of the spring disk 145 (the urging member) of the fail-safe valve 140 functions as the valve seat of the fail-safe valve 140 and the shaft of the valve spool 82 (valve body). The bottom surface 113 of the counterbore portion 112 and the annular convex portion 135 of the core 99 formed in the stepped recess 110 of the head portion 7 of the piston bolt 5 with the outer peripheral edge portion 152 of the disk 151 (regulatory member) that restricts movement in the direction. The inner peripheral edge portion 147 of the spring disk 145 is brought into contact with the lower end surface 142 (one side in the axial direction) of the flange portion 141 provided at the upper end portion 90 of the valve spool 82, and is placed on the flange portion 141. The end surface 143 (on the other side in the axial direction) was brought into contact with the inner peripheral edge portion 154 of the disk 151 so as to be able to take off and sit.

According to the first embodiment, when the disc 151 is charged (press-fitted) into the counterbore portion 112, the claw portion 155 of the disc 151 is pressed against the side surface 114 of the counterbore portion 112, so that the claw portion 155 becomes the disc 151. It is elastically deformed so as to bend with the end surface 153 as a fulcrum, and the outer corner portion 156 of the claw portion 155 is abutted against the side surface 114 of the counterbore portion 112 so as to be stretched.
As a result, in the first embodiment, from the time when the valve spool 82 (valve body) is inserted into the common passage 11 of the piston bolt 5 until the solenoid 91 (solenoid case 94) is connected to the piston bolt 5. During, for example, even if the head portion 7 of the piston bolt 5 is turned downward when assembling the valve component to the shaft portion 6 of the piston bolt 5, the flange portion 141 of the valve spool 82 is received by the inner peripheral edge portion 154 of the disk 151. Therefore, it is possible to prevent the valve spool 82 from falling out of the common passage 11.
Therefore, even if the head portion 7 of the piston bolt 5 in which the valve spool 82 is inserted in the common passage 11 is turned downward at the time of assembly, the valve spool 82 is held down as in the conventional case (prevents the valve spool 82 from coming off). Since it is not necessary, the assembling property can be improved.
Further, in the first embodiment, the disk 151 is provided with an orifice 157 that communicates the annular passage 117 formed on the outer periphery of the annular convex portion 135 of the core 99 with the first chamber 121 of the stepped recess 110 of the piston bolt 5. Therefore, by adjusting the flow path area of the orifice 157 (the product of the thickness of the disk 151 and the orifice width), the damping force generated at the time of failing can be appropriately set.
Further, in the first embodiment, since a plurality of openings 158 are formed around the shaft hole 159 of the disk 151, the stress due to the elastic deformation of the claw portion 155 is increased in the radial direction by deforming the openings 158. It is possible to escape to the disk 151, which functions as a valve seat of the fail-safe valve 140, and can maintain the flatness with respect to the retainer 148.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG. Here, the differences from the first embodiment will be described. For the parts common to the first embodiment, the same names and reference numerals will be used, and duplicate description will be omitted.
In the first embodiment, the outer corner portion 156 of the claw portion 155 of the disc 151 (regulatory member) is abutted against the side surface 114 of the counterbore portion 112 of the piston bolt 5, and the valve spool 82 is provided by the inner peripheral edge portion 154 of the disc 151. By receiving the flange portion 141 of the (valve body), the valve spool 82 is configured to prevent the valve spool 82 from falling out of the common passage 11 of the piston bolt 5.

On the other hand, in the second embodiment, the outer peripheral surface 166 of the claw portion 165 of the disk 151 is press-fitted into the counterbore portion 112 of the piston bolt 5 to bring it into surface contact, and the valve spool 82 is brought into surface contact by the inner peripheral edge portion 154 of the disk 151. By receiving the flange portion 141 of the (valve body), the valve spool 82 is configured to prevent the valve spool 82 from falling out of the common passage 11 of the piston bolt 5.

As shown in FIG. 5, the claw portion 165 is formed in an upward R shape with the disc 151 inserted (press-fitted) into the counterbore portion 112. As a result, when the disc 151 is charged (press-fitted) into the counterbore portion 112, the claw portion 165 is elastically deformed with the end surface 153 of the disc 151 as a fulcrum by being pressed against the side surface 114 of the counterbore portion 112, and the outer periphery thereof is formed. The surface 166 is pressed against the side surface 114 of the counterbore portion 112.

According to the second embodiment, it is possible to obtain the same effect as that of the first embodiment described above.
Further, in the second embodiment, the outer peripheral surface 166 of the claw portion 165 of the disc 151 is brought into surface contact with the counterbore portion 112 of the piston bolt 5, so that the counterbore portion 112 of the disc 151 is compared with the first embodiment. It is possible to increase the press-fitting allowance (contact length in the axial direction), and more effectively, it is possible to prevent the valve spool 82 from falling out of the common passage 11 of the piston bolt 5.

(Third Embodiment)
Next, a third embodiment will be described with reference to FIG. Here, the differences from the first or second embodiment will be described. For the parts common to the first or second embodiment, the same names and reference numerals are used, and duplicate explanations are omitted.
In the second embodiment, the claw portion 165 is formed in an upward R shape with the disc 151 inserted (press-fitted) into the counterbore portion 112.

On the other hand, in the third embodiment, the claw portion 175 is formed downward into an R shape with the disc 151 inserted (press-fitted) into the counterbore portion 112. As shown in FIG. 6, an annular groove 181 for releasing (accommodating) the claw portion 175 of the disc 151 is formed on the outer peripheral edge portion of the bottom surface 113 of the counterbore portion 112 of the piston bolt 5. An annular groove 182 is formed on the inner peripheral side of the annular groove 181 of the bottom surface 113 of the counterbore portion 112. The annular groove 181 and the annular groove 182 have a constant width in the radial direction (“horizontal direction” in FIG. 6), and the upper end surface 184 is an annular protrusion that abuts on the outer peripheral edge portion 152 of the disk 151. The portion 183 is formed.

The height (axial length) of the annular convex portion 183 with respect to the bottom surface 113 of the counterbore portion 112 is set to the sum of the plate thickness of the spring disk 145 and the plate thickness of the retainer 148. The end surface of the outer peripheral edge portion 146 of the spring disk 145 and the end surface of the outer peripheral edge portion 149 of the retainer 148 are in contact with the inner peripheral side surface 185 of the annular convex portion 183. That is, the outer diameters of the spring disc 145 and the retainer 148 in the second embodiment are formed to be smaller than the outer diameters of the spring disc 145 and the retainer 148 in the first embodiment. The portion of the outer peripheral edge portion 152 of the disk 151 protruding radially outward from the edge of the retainer 148 (“right side” in FIG. 6) is formed by the annular convex portion 135 of the core 99 and the annular convex portion 183 of the piston bolt 5. Held between. The annular groove 182 is a relief groove for releasing the edge of the outer peripheral edge portion 146 of the spring disc 145.

Then, when the disc 151 is charged (press-fitted) into the counterbore portion 112, the claw portion 175 is elastically deformed with the end surface 153 of the disc 151 as a fulcrum by being pressed against the side surface 114 of the counterbore portion 112, and the outer peripheral surface thereof is formed. 176 is pressed against the side surface 114 of the counterbore portion 112. A tapered portion 187 for guiding the claw portion 175 when the disc 151 is loaded is formed at the opening edge portion of the counterbore portion 112 of the piston bolt 5.

According to the third embodiment, it is possible to obtain the same effect as that of the first or second embodiment described above.
Further, in the third embodiment, since the claw portion 175 of the disk 151 is extended downward, the counterbore portion 112 of the piston bolt 5 is not deepened, that is, the axial length of the head portion 7 of the piston bolt 5 is extended. It is possible to increase the press-fitting allowance (contact length in the axial direction) of the disk 151 with respect to the counterbore portion 112 as compared with the second embodiment, and more effectively, the valve spool 82 is a piston. It is possible to prevent the bolt 5 from falling out of the common passage 11.

1 shock absorber, 2 cylinder, 2A cylinder upper chamber (one side chamber), 2B cylinder lower chamber (other side chamber), 3 piston, 5 piston bolt, 11 common passage, 15 piston rod, 23 extension side main valve, 26 extension side back Pressure chamber, 53 contraction side main valve, 56 contraction side back pressure chamber, 81 pilot valve, 82 valve spool (valve body), 91 solenoid (actor), 141 flange part, 145 spring disk (urging member), 151 disk ( Regulatory member)

Claims (3)

A cylinder in which the working fluid is sealed, and
A piston that is slidably fitted in the cylinder and divides the inside of the cylinder into a cylinder one-side chamber and a cylinder other-side chamber.
A piston rod whose one end is connected to the piston and whose other end extends outward from the cylinder.
The extension side passage and the contraction side passage provided in the piston,
The extension side main valve provided in the extension side passage and the extension side main valve
An extension side back pressure chamber that adjusts the valve opening pressure of the extension side main valve, and
The contraction side main valve provided in the contraction side passage and
The contraction side back pressure chamber that adjusts the valve opening pressure of the contraction side main valve, and
A common passage connecting the extension side back pressure chamber and the contraction side back pressure chamber,
A piston bolt that is inserted into the shaft hole of the piston to form the common passage,
A pilot valve that controls the flow of oil and liquid in the common passage,
Equipped with
The pilot valve includes a valve body provided in the common passage and whose movement is controlled by an actuator, and an urging member for urging the valve body in the valve opening direction.
A shock absorber characterized in that a regulating member for restricting the axial movement of the valve body is provided between the valve body and the piston bolt. The urging member and the regulating member are formed in a plate shape, a flange portion is provided on the valve body, and the urging member is abutted on one side of the flange portion in the axial direction, and the flange portion is provided with the flange portion. The shock absorber according to claim 1, wherein the regulating member is brought into contact with the other side in the axial direction. The shock absorber according to claim 1 or 2, wherein the regulating member includes an orifice through which a working fluid flowing between the common passage and the cylinder one-side chamber can flow.

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