JP2018115684A - Attenuation force adjusting-type damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel attenuation force adjusting-type damper which can suppress noise and vibration accompanied by a change of a flow of a working fluid in the damper at an operation to the minimum.SOLUTION: An attenuation force adjusting-type damper comprises: a main valve 41 for regulating a flow of a working fluid to the other side chamber from one side chamber; a pilot chamber for energizing the main valve 41 in a valve closing direction; an introduction path resistance element 25 for introducing the flow of the working fluid in one side chamber into the pilot chamber by limiting it; and a control valve which can adjust pressure in the pilot chamber by controlling the flow of the working fluid flowing into the pilot chamber via the introduction path resistance element 25 to the other side chamber. The control valve has a linear solenoid 70, a movable element 73 which is driven by the linear solenoid 70 in an axial direction, a valve body arranged at one end of the movable element 73, and a valve seat on which the valve body is seated, and which opens and closes a communication path 41G for making the pilot chamber and the other side chamber communicate with each other. The working fluid forms a flow in one direction without returning to the other side chamber from one side chamber.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a shock absorber that generates a damping force with respect to a stroke of a piston rod, and more particularly to a damping force adjusting type shock absorber that can control the damping force.

  In a shock absorber used in a vehicle such as an automobile, a traveling state such as road surface unevenness and vehicle body movement is detected by a sensor, and the operating pressure of a valve for opening and closing an oil passage provided in the piston of the shock absorber is changed by a linear solenoid. Thus, a semi-active suspension system (damping force adjustment type shock absorber) that adjusts the damping force according to the traveling state is widely adopted.

  The semi-active suspension system has an advantage that it consumes less power than an active suspension system in which an actuator is operated by a power source, has a simple structure and is compact, and is relatively inexpensive and excellent in mountability.

  As a background art in this technical field, for example, there is a technique such as Patent Document 1. Japanese Patent Application Laid-Open No. 2004-133826 discloses a damping force adjusting type shock absorber “an extension side passage and a pressure side passage communicating the extension side chamber and the pressure side chamber, an extension side valve body for opening and closing the extension side passage, and a pressure side valve for opening and closing the pressure side passage. Body, an expansion back pressure chamber for energizing the expansion valve body, a compression back pressure chamber for energizing the compression side valve element, and an expansion side resistance element that communicates with the expansion side back pressure chamber and a compression resistance. A communication passage communicating with the compression side back pressure chamber through the element, an expansion side pressure introduction passage communicating the expansion side chamber and the compression side back pressure chamber, a pressure side pressure introduction passage communicating the compression side chamber and the expansion side back pressure chamber, An extension side that includes an adjustment passage connected to the communication passage, and an electromagnetic pressure control valve that is provided in the adjustment passage and controls the upstream pressure of the adjustment passage, and biases the extension side valve body by the pressure of the extension side back pressure chamber It is described that the load is made larger than the pressure side load for urging the pressure side valve body by the pressure in the pressure side back pressure chamber.

  Patent Document 2 discloses that “a cylinder, a piston that is slidably inserted into the cylinder and divides the cylinder into an extension side chamber and a pressure side chamber, and a damping passage that communicates the extension side chamber and the pressure side chamber. A pressure chamber communicated with the extension side chamber and the pressure side chamber; and a pressure chamber which is movably inserted into the pressure chamber and communicated with the extension side chamber through the pressure chamber and the pressure side chamber. There is disclosed a shock absorber including a free piston that is partitioned into a pressure side pressure chamber and a damping force adjusting unit that is provided in the damping passage and that can change the resistance applied to the flow of liquid passing therethrough.

Japanese Patent Laying-Open No. 2015-72047 Japanese Patent Laying-Open No. 2015-94366

  By the way, in a semi-active suspension system (damping force adjustment type shock absorber), noise vibration due to changes in the flow of the working fluid (oil) during operation depends on the arrangement of the control valve built in the shock absorber and the structure of the oil passage. It can be a problem.

  In the structure described in the above-mentioned Patent Document 1, the working fluid during the extension process first passes from the upper extension side chamber through the introduction path below the piston and changes the flow direction upward to change the electromagnetic pressure above the piston. After moving toward the control valve and passing through the electromagnetic control valve, the flow direction is changed again, and the flow flows downward to the pressure side chamber. For this reason, when the flow direction is changed as described above, it tends to be a cause of noise vibration due to loss.

  Further, in the structure of Patent Document 2, the number of built-in control valves is large and the path of the hydraulic oil is complicated, and the hydraulic oil flows from the outside to the inside of the shock absorber during operation and then flows outward again. Noise and vibration are likely to occur.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a novel damping force adjustment type shock absorber capable of suppressing as much as possible noise vibration accompanying a change in the flow of working fluid inside the shock absorber during operation.

  The present invention made in view of the above circumstances includes 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 one side chamber and another side chamber, and one end of the piston A piston rod connected to the piston and having the other end extending to the outside of the cylinder and a damping force provided on the piston and controlling the flow of the working fluid from the one side chamber to the other side chamber by the movement of the piston A damping force adjustment type shock absorber comprising: a main valve that regulates a flow of working fluid from the one side chamber to the other side chamber; and A pilot chamber energizing in the valve closing direction, an introduction path resistance element that restricts the flow of the working fluid in the one side chamber and leads the pilot chamber to the pilot chamber, and flows into the pilot chamber via the introduction path resistance element And a control valve capable of adjusting the pressure in the pilot chamber by controlling the flow of the working fluid to the other side chamber, the control valve in the axial direction of the piston by the linear solenoid. A movable element to be driven; a valve body provided at one end of the movable element; and a valve seat on which the valve body is seated and which opens and closes a communication passage communicating the pilot chamber and the other chamber. The introduction path resistance element, the valve body, and the valve seat are arranged in this order from the one side chamber toward the other side chamber, and the working fluid flows in one direction without returning from the one side chamber toward the other side chamber. It is characterized by becoming.

  ADVANTAGE OF THE INVENTION According to this invention, the novel damping force adjustment type shock absorber which can suppress the noise vibration accompanying the change of the flow of the working fluid inside a shock absorber at the time of operation | movement as much as possible is realizable.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

It is a figure which shows schematic structure of the damping force adjustment type shock absorber for semi-active suspensions to which this invention is applied. It is sectional drawing which shows the damping-force generation mechanism of the damping-force adjustment type buffer of Example 1. FIG. FIG. 3 is an enlarged cross-sectional view of the vicinity of a pilot valve portion and a main valve portion in a normal operation state of the damping force generation mechanism shown in FIG. 2. It is the figure which looked at the main valve shown in FIG. 3 from the upper direction of FIG. It is the figure which looked at the pilot valve shown in FIG. 3 from the upper part of FIG. It is the figure which looked at the pilot valve 2nd valve part seat member shown in Drawing 3 from the upper part of Drawing 3. It is the figure which looked at the fail valve seat member shown in FIG. 3 from the upper part of FIG. It is the figure which looked at the fail valve shown in FIG. 3 from the upper part of FIG. FIG. 3 is an enlarged cross-sectional view of the vicinity of a pilot valve portion and a main valve portion in a fail operation state of the damping force generation mechanism shown in FIG. 2. FIG. 3 is an enlarged cross-sectional view in which the vicinity of the pilot valve portion and the main valve portion in the normal operation state of the damping force generation mechanism in which the shape of the pilot valve valve seat portion is changed in the first embodiment. FIG. 6 is an enlarged cross-sectional view in which the vicinity of a pilot valve portion and a main valve portion in a normal operation state of a damping force generation mechanism of Embodiment 2 is enlarged. It is the expanded sectional view which expanded the pilot valve part and main valve part vicinity of the fail operation state of the damping force generation mechanism of Example 2. It is the figure which looked at the pilot valve 2nd valve part seat member of Example 2 from the upper part of FIG. It is the expanded sectional view which expanded the pilot valve part and main valve part vicinity of the fail operation state of the damping force generation mechanism of Example 3. It is the figure which looked at the main valve of Example 3 from the upper part of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and application examples are included in the technical concept of the present invention. Is also included in the range. In the drawings, the same components are denoted by the same reference numerals, and detailed description of the overlapping portions is omitted.

  With reference to FIG. 1 thru | or FIG. 9, the damping force adjustment type shock absorber of the 1st Embodiment of this invention is demonstrated. FIG. 1 shows the overall configuration of a damping force adjusting shock absorber 1 for a semi-active suspension. As shown in FIG. 1, the damping force adjusting type shock absorber 1 according to the present embodiment includes a cylinder 2, a piston 5 sliding in the cylinder 2, a piston rod 6 connected to the piston 5, a reservoir 4, a damping force generation It comprises a mechanism 7 and the like, and is mounted between two relatively movable members such as a sprung (vehicle body) side and a non-spring (wheel side) of a suspension device of a vehicle (not shown).

  The damping force adjustment type shock absorber 1 has a double cylinder structure in which an outer cylinder 3 is provided outside the cylinder 2, and a reservoir 4 is formed between the cylinder 2 and the outer cylinder 3.

  A piston 5 is slidably inserted in the cylinder 2, and the inside of the cylinder 2 is divided into a cylinder upper chamber 2A and a cylinder lower chamber 2B by the piston 5.

  The piston 5 is connected to the piston rod 6 via the piston case 20, and the end of the piston rod 6 opposite to the piston 5 passes through the cylinder upper chamber 2 </ b> A, passes through the oil seal 9, and is outside the cylinder 2. It protrudes. A base valve 10 that separates the cylinder lower chamber 2 </ b> B and the reservoir 4 is provided on the lower end side of the cylinder 2.

  The base valve 10 is provided with passages 15 and 16 that allow the cylinder lower chamber 2B and the reservoir 4 to communicate with each other. The passage 15 is provided with a check valve 17 that allows only fluid flow from the reservoir 4 to the cylinder lower chamber 2B. In the passage 16, the pressure of the fluid on the cylinder lower chamber 2B side reaches a predetermined pressure. There is provided a relief valve 18 that is sometimes opened to relieve it to the reservoir 4 side.

  As working fluid, working oil is sealed in the cylinder 2, and working oil and gas are sealed in the reservoir 4. In FIG. 1, reference numeral 3A is a bottom cap joined to the lower end of the outer cylinder 3, and reference numeral 19 is an attachment eye joined to the bottom cap 3A.

  FIG. 2 is an enlarged cross-sectional view of the vicinity of the piston 5 and the damping force generation mechanism 7 in FIG. 1, and shows a detailed structure of the damping force generation mechanism of this embodiment. FIG. 3 is an enlarged cross-sectional view in which the vicinity of the pilot valve portion and the main valve portion in the normal operation state of the damping force generation mechanism 7 shown in FIG. 2 is enlarged.

  The piston 5 has a substantially cylindrical shape, and has an inner flange portion 5A extending inward at the lower end portion. The piston 5 is fixed to the lower side (cylinder lower chamber 2B side) of the substantially cylindrical piston case 20 disposed in the cylinder 2. Is done. Inside the piston case 20, a first shaft hole 21 and a second shaft hole 23 whose diameter decreases stepwise from the cylinder upper chamber 2A side are provided in order, and similarly, the diameter decreases stepwise from the cylinder lower chamber 2B side. The third shaft hole 26 and the fourth shaft hole 22 are sequentially provided.

  At the lower end of the piston case 20, a valve seat member 31 from which a main valve 41 described later is detached and seated is provided. The valve seat member 31 includes a cylindrical shaft portion 35, a flange portion 32 formed at the lower end of the shaft portion 35, and a screw portion 33 formed on the outer peripheral surface of the shaft portion 35.

  Further, the valve seat member 31 is fixed to the piston case 20 by screwing the screw portion 33 into the screw portion 24 formed in the third shaft hole 26 of the piston case 20. Further, the inner flange portion 5 </ b> A of the piston 5 is sandwiched between the lower end portion end surface of the piston case 20 and the flange portion 32 of the valve seat member 31, and the piston 5 is fixed to the lower end portion of the piston case 20.

  The upper end of the piston case 20 is closed by a substantially cylindrical coil cap 30. The coil cap 30 has a threaded portion 36 formed on the outer peripheral surface of the upper end portion, and the threaded portion 36 is screwed into a threaded portion 27 formed at the upper end of the first shaft hole 21 of the piston case 20, thereby 20 is fixed. Further, the coil cap 30 is formed with an annular seal groove along the outer peripheral surface of the lower end portion, and the space between the first shaft hole 21 of the piston case 20 is sealed by an O-ring 81 attached to the seal groove. .

  One end of the piston rod 6 is connected to the center of the upper end portion of the coil cap 30, and the other end side of the piston rod 6 passes through the cylinder upper chamber 2 </ b> A and is attached to the upper end portions of the cylinder 2 and the outer cylinder 3. The inserted rod guide 8 and oil seal 9 (see FIG. 1) are inserted to extend outside the cylinder 2.

  Then, the flow of hydraulic oil between the two chambers of the cylinder upper chamber 2A and the cylinder lower chamber 2B generated by the movement (extension / contraction) of the piston rod 6 is controlled in the piston case 20 and thus in the cylinder 2. A damping force generation mechanism 7 for generating a damping force is provided. The damping force generation mechanism 7 includes a main valve unit 40 that controls the valve closing by the pressure of the pilot chamber 42 described later, and a pilot valve unit 50 that controls the pressure of the pilot chamber 42 by the linear solenoid 70.

  The main valve portion 40 includes a main valve 41, a valve seat member 31 on which the main valve 41 is seated, and a compression coil spring 65 that biases the main valve 41 in the valve closing direction.

  FIG. 4 shows the shape of the main valve 41, which will be described with reference to this also. The main valve 41 is formed in a substantially bottomed cylindrical shape having a recess, and the inside is provided with a large-diameter portion 41D having a large diameter on the release side (upper side) and a small-diameter portion 41C having a small diameter on the bottom side. . A groove 41A is provided on the outermost diameter side of the stepped portion 41F formed thereby, and a communication path 41B that communicates between the groove and the center is provided.

  As shown in FIG. 3, a flange portion 41 </ b> H (outer flange) is formed at the lower end of the main valve 41. On the lower end surface of the flange portion 41H of the main valve 41, an annular seat portion 39 that is separated from and seated on the valve seat 38 of the valve seat member 31 is formed.

  When the seat portion 39 is seated on the valve seat 38 of the valve seat member 31, an annular chamber 84 is formed between the lower end portion of the piston case 20, the valve seat member 31, and the main valve 41. A plurality of passages 34 communicating the annular chamber 84 and the cylinder upper chamber 2A are provided at the lower end of the piston case 20.

  The main valve 41 has a cylindrical outer peripheral surface 88 slidably inserted into the fourth shaft hole 22 of the piston case 20, and an outer peripheral surface of the flange portion 41 H slides into the third shaft hole 26 of the piston case 20. Inserted as possible. Thereby, an annular back pressure chamber 46 is formed between the main valve 41 and the third shaft hole 26.

  A valve seat 48 is provided at the bottom of the concave portion of the main valve 41, from which an annular seat portion 62 formed on the pilot valve 51 described later is detached and seated. Further, a communication passage 41G communicating with the cylinder lower chamber 2B is provided inside the valve seat 48.

  On the upper end side of the main valve 41, a compression coil spring 65 that applies a set load is installed between the piston case 20. As a result, the piston case 20 is biased downward, that is, in the valve closing direction.

  Next, the pilot valve unit 50 will be described. The pilot valve portion 50 is disposed on the upper surface of the step portion 41F of the main valve 41 in order from the bottom, a pilot valve second valve portion seat member 53, a fail valve support member 54, a fail valve 55, a fail valve seat member 56, and a fail valve fixing. 58, pilot valve 51 disposed inside small diameter portion 41C of main valve 41, operating pin 71 for fixing pilot valve 51 at the lower end, fail spring 59 acting in the valve opening direction, pilot spring 61, linear solenoid 70.

  FIG. 5 shows the shape of the pilot valve 51, which will be described with reference to this also. The pilot valve 51 has a substantially cylindrical bottom shape. The cylinder has a disk portion 51A, a bottomed central hole 51C, and a communication hole 51G communicating from the bottom to the lower portion. A seat portion 62 is provided at the lower portion of the cylinder. The annular convex part 51B is formed on the outer side of the disc part 51A on the side opposite to the sheet part 62. The seat portion 62 is formed to have a “first valve portion” that can open and close a flow path between the seat portion 48 and the valve seat portion 48 formed in the main valve 41. The diameter of the seat portion 62 is set to be smaller than the outer diameter of an operating pin 71 described later.

  The outer diameter portion of the annular convex portion 51B is set so that the pilot valve 51 can operate through a small gap or slide through the small diameter portion 41C of the main valve 41.

  Further, the disc chamber 51A separates the valve chamber in which the pilot valve 51 is arranged into an upstream chamber 51D on the upstream side and a downstream chamber 51E on the downstream side. A plurality of communication passages 52 that communicate the upstream chamber 51D and the downstream chamber 51E are formed in the disc portion 51A of the pilot valve 51. The annular convex portion 51B functions as a “second valve portion” to be described later. Further, a fail spring 59 of a compression coil spring is disposed between the lower end of the disc portion 51A and the bottom of the concave portion of the main valve 41.

  FIG. 6 shows the shape of the pilot valve second valve portion seat member 53, which will be described with reference to this also. The pilot valve second valve portion seat member 53 is formed in a disc shape having a hole 53A in the center as shown in FIG. 6, and the tip of the annular convex portion 51B of the pilot valve 51 is in contact with the disc portion. Arranged so as to be in contact with and away from each other. Thereby, the 2nd valve part which opens and closes the flow path of the communicating path 41B provided in the main valve 41 is formed. A space 53B is provided between the outer diameter side and the large diameter portion 41D of the main valve 41.

  FIG. 7 shows the shape of the fail valve seat member 56, which will be described with reference to this also. As shown in FIG. 7, the fail valve seat member 56 is formed in a disc shape in which a hole 56 </ b> C having a diameter similar to that of a later-described operation pin 71 is provided in the center, and a shape in which a plurality of communication holes 56 </ b> A are provided. There is a disc shape in which a space 56B is provided between the outer diameter side and the large diameter portion 41D of the main valve 41.

  FIG. 8 shows the shape of the fail valve 55, which will be described with reference to this also. The fail valve 55 has a disk shape as shown in FIG. 8, and is formed to be elastically deformable. The outer side is sandwiched between a fail valve support member 54 and a fail valve seat member 56, which will be described later, and the upstream pressure acts on the upper surface of the fail valve 55 by a communication hole 56A provided in the fail valve seat member 56. It functions as a relief valve that opens the flow path through the communication hole 56A. Further, a space 56B is provided between the outer diameter side and the large diameter portion 41D of the main valve 41.

  The fail valve support member 54 is provided between the fail valve 55 and the pilot valve second valve portion seat member 53 and has a disk shape with a hole in the center. The outer side of the fail valve 52 is an opening / closing portion of the fail valve 55. It is held as a fulcrum of movement. On the outer diameter side, a space 54B is provided between the main valve 41 and the large diameter portion 41D.

  The fail valve fixing portion 58 is installed on the cylinder upper chamber 2A side of the fail valve seat member 56, has a disk shape, and has a communication passage 58A at the center and a communication passage 58B at the outer edge. By fixing the fail valve fixing portion 58 to the main valve 41, the pilot valve second valve portion seat member 53, the fail valve support member 54, the fail valve 55, and the fail valve seat member 56 are fixed to the main valve 41. Is done. A space (communication path) 58 </ b> B is provided between the outer diameter side of the fail valve fixing portion 58 and the large diameter portion 41 </ b> D of the main valve 41.

  A valve chamber 63 is formed inside the fourth shaft hole 22 and the annular convex portion 29 of the piston case 20 and above the fail valve fixing portion 58. The valve chamber 63 communicates with the piston upper chamber 2 </ b> A through an introduction communication passage 25 provided in the piston case 20. The introduction communication path 25 is configured by a resistance element that generates flow path resistance due to an orifice restriction or the like.

  The valve chamber 63 is provided on each outer edge side of the fail valve fixing portion 58, the fail valve seat member 56, the fail valve 55, the fail valve support member 54, the fail valve 55, and the pilot valve second valve portion seat member 53. The spaces 58B, 56B, 55B, 54B and 53B communicate with the groove 41A provided in the main valve 41, and further communicate with the small diameter portion 41C of the main valve 41 through the communication passage 41B. Further, when the second valve portion of the pilot valve 51 is open, the pilot valve 51 communicates with the upstream chamber 51D, the communication passage 52, and the downstream chamber 51E. The pilot chamber 42 of the main valve 41 is formed in the chamber from the valve chamber 63 to the downstream chamber 51E, and a force in the valve closing direction acts on the main valve 41 by the pressure of the pilot chamber 42.

  The linear solenoid 70 includes a case member 74 in which a plunger bore is formed, and a core 76 in which a recess 76B in which a lower end portion of the plunger 73 is slidably fitted is formed. The case member 74 is formed in a substantially cylindrical shape, and a flange portion 74A is formed on the outer periphery of the upper end portion. Further, the upper end portion of the case member 74 is fitted into a recess formed on the lower end surface of the coil cap 30. Further, the case member 74 is provided with a sleeve 78 on the outer peripheral surface, and the lower end portion of the sleeve 78 is fitted into the second shaft hole 23 of the piston case 20. As a result, the case member 74 is positioned coaxially with respect to the center line of the piston case 20.

  On the other hand, the core 76 is formed in a substantially cylindrical shape, and a flange portion 76A is formed on the outer periphery of the lower end portion. The core 76 has a flange portion 76 </ b> A fitted into the second shaft hole 23 of the piston case 20, and the flange portion 76 </ b> A is formed between the second shaft hole 23 and the fourth shaft hole 22 of the piston case 20. By being abutted against the annular convex portion 29, it is positioned in the vertical direction with respect to the piston case 20.

  The inner peripheral surface of the lower end portion of the sleeve 78 is fitted to the outer peripheral surface of the core 76. The sleeve 78 is positioned in the vertical direction with respect to the piston case 20 by abutting the lower end portion against the flange portion 76 </ b> A of the core 76. Further, an O-ring 83 is disposed between the case member 74 and the sleeve 78, and an O-ring 83 is disposed between the sleeve 78 and the fourth shaft hole 22 of the piston case 20, and each seals.

  On the other hand, the operation pin 71 is supported by a pair of bushes 85 and 86 assembled to the case member 74 and the core 76 so as to be movable in the vertical direction. Further, the lower end of the operating pin 71 is brought into contact with and fitted into the bottom of the center hole 51 </ b> C provided in the pilot valve 51. The operation pin 71 has a shaft hole 71 </ b> B that communicates the upper side of the operation pin 71 and the lower side of the pilot valve 51 together with the communication hole 51 </ b> G of the pilot valve 51.

  A retaining ring 60 is mounted in an annular groove formed on the outer peripheral surface of the operating pin 71. The retaining ring 60 is engaged with an upper end portion of a pilot spring 61 having a lower end portion sandwiched between the main valve 41 and the compression coil spring 65. As a result, the operating pin 71 is urged upward by the spring force of the pilot spring 61.

  The specific operation of the damping force adjusting shock absorber according to the present embodiment having the above-described configuration will be described. First, the operation in the normal state will be described with reference to FIG.

The damping force adjusting shock absorber 1 is mounted between the sprung and unsprung parts of a vehicle suspension device. When the vehicle is traveling, when vibration in the vertical direction is generated due to road surface unevenness or the like, the damping force adjusting shock absorber 1 is displaced so that the piston rod 6 extends and contracts from the outer cylinder 3, and the damping force generating mechanism 7 generates a damping force to buffer the vibration of the vehicle. (See Figure 1)
At this time, the damping force generation mechanism 7 can control the force acting on the main valve 41 by adjusting the thrust (control current) of the linear solenoid 70, so that the damping force can be variably adjusted.

  First, the extension stroke of the piston rod 6 will be described. During the extension process, the hydraulic oil on the cylinder upper chamber 2A side is pressurized by the movement of the piston 5 in the cylinder 2.

  A case where a current is applied to the linear solenoid 70 will be described. The hydraulic oil from the cylinder upper chamber 2A, as in the flow F1 shown in FIG. 3, introduces the communication passage 25, the valve chamber 63, the spaces 58B, 56B, 55B, 54B, 53B, the groove 41A of the main valve 41, the communication passage. It flows to the cylinder lower chamber 2B through 41B, the upstream chamber 51D of the pilot valve 51, the pilot valve communication passage 52, the downstream chamber 51E, the first valve portion, and the communication passage 41G.

  At this time, when the pressure of the pilot chamber 42 is P, the pilot valve 51 has a force of (S1−S2) × P from the area S1 due to the outer diameter of the operating pin 71 and the area S2 of the seat portion 62. It works in the valve opening direction of the first valve part. Further, a force Fsp in the valve opening direction by the fail spring 59 and the pilot spring 61 acts. On the other hand, the linear solenoid 70 generates Fsol in the valve closing direction. Therefore, the pressure P can be adjusted by controlling the force Fsol generated by the linear solenoid 70 from the force balance equation (S1-S2) × P + Fsp = Fsol. That is, if the solenoid thrust (control current) is large, the opening of the first valve portion becomes small, the pressure in the pilot chamber 42 increases, and if the solenoid thrust (control current) is small, the opening of the first valve portion becomes large. The pressure in the pilot chamber 42 decreases.

  The pressure in the pilot chamber 42 is applied to the main valve 41 by an area generated by the difference in the diameter of the seat portion 62 of the pilot valve 51 and the diameter of the fourth shaft hole 22 of the piston case 20. On the other hand, the force in the valve opening direction acts on the pressure in the piston upper chamber 2A due to the area generated by the difference between the diameter of the flange portion 41H of the main valve 41 and the diameter of the valve seat portion of the main valve 41. The force of the compression coil spring 65 in the valve closing direction of the main valve 41 is also acting, and operates according to these balances. That is, by controlling the pressure in the pilot chamber 42, the valve opening of the main valve 41 is controlled, the pressure in the cylinder upper chamber 2A is controlled, and an appropriate damping force is generated.

  When the main valve 41 is opened, as shown by the flow of F2, it flows into the cylinder lower chamber 2B from the cylinder upper chamber 2A through the valve seat portion. At this time, the hydraulic oil corresponding to the piston rod 6 withdrawn from the cylinder 2 flows from the reservoir 4 into the cylinder lower chamber 2B by opening the check valve 17 of the base valve 10.

  Next, the contraction process of the piston rod 6 will be described. When the control current of the linear solenoid 70 is low, the force that pushes up the operating pin 71 by the pilot spring 61 exceeds the thrust of the linear solenoid 70. As a result, the seat portion 62 of the first valve portion of the pilot valve 51 is disengaged from the valve seat 48 provided on the main valve 41, and the first valve portion of the pilot valve 51 is opened.

  As a result, the hydraulic oil in the cylinder lower chamber 2B flows into the communication passage 41G of the main valve 41, the communication passage 52 of the pilot valve 51, the communication passage 41B of the main valve 41, the groove portion 41A, the pilot valve second valve portion seat member 53, the fail. The valve 55, the fail valve support member 54, the fail valve 55, the fail valve seat member 56, and the fail valve fixing portion 58 are introduced through the spaces 53B, 54B, 55B, 56B, 58B and the valve chamber 63 provided at the outer edge portions of the fail valve fixing portion 58 It passes through the communication passage 25 and flows into the cylinder upper chamber 2A.

  When the control current of the linear solenoid 70 is high, the thrust of the linear solenoid 70 exceeds the force that the pilot spring 61 pushes up. As a result, the seat portion 62 of the pilot valve 51 is seated on the valve seat 48 provided on the main valve 41, whereby the first valve portion of the pilot valve 51 is closed.

  In this state, since the main valve 41 and the pilot valve 51 are considered to be integrated, the valve opening pressure of the main valve 41 depends on the thrust of the plunger 73 generated by the linear solenoid 70. At this time, the main valve 41 has a valve closing direction force due to the difference in diameter between the diameter of the third shaft hole 26 of the piston case 20 and the diameter of the seat portion 39 due to the pressure on the cylinder lower chamber 2B side, A force in the valve opening direction of the area due to the diameter difference between the diameter of the shaft hole 22 and the outer diameter of the operating pin 71 acts, but the valve opens by overcoming the solenoid thrust, and the cylinder is opened from the cylinder lower chamber 2B via the seat portion 39. The hydraulic oil flows into the upper chamber 2A.

  And the hydraulic oil for the amount that the piston rod 6 has entered the cylinder 2 is such that the pressure in the cylinder lower chamber 2B reaches the valve opening pressure of the relief valve 18 of the base valve 10, and the relief valve 18 opens. It flows to the reservoir 4.

  Next, a failure operation state when the control current is cut off due to disconnection of the coil of the linear solenoid 70, failure of the control device, or waiting for a signal will be described with reference to FIG.

  When the control current to the linear solenoid 70 is interrupted, the thrust of the plunger 73 and the operating pin 71 disappears, so that the pilot valve 51 moves away from the valve seat 48 provided on the main valve 41 by the spring force of the fail spring 59. Move to. As a result, the seat portion 62 of the first valve portion of the pilot valve 51 is detached from the valve seat 48, and the first valve portion of the pilot valve 51 is opened.

  When the pilot valve 51 is moved upward, the second valve portion formed on the annular convex portion 51B of the pilot valve 51 is brought into contact with the pilot valve second valve portion seat member 53, and the communication passage 41B is formed by the second valve portion. Closed.

  In this state, in the extension process, the hydraulic oil in the cylinder upper chamber 2A is pressurized and pressure is applied to the fail valve 55 through the communication hole 56A of the fail valve seat member 56. When this pressure becomes a predetermined pressure, the fail valve 55 is deformed so as to open a flow path between the fail valve seat member 56. The fail valve 55 is formed to be elastically deformable so that the communication hole 56A of the fail valve seat member 56 can be opened and closed, and functions as a relief valve that opens at a predetermined pressure or higher.

  The flow from the cylinder upper chamber 2A at this time, as shown by F1 in FIG. 9, the introduction communication path 25, the center hole 58A of the fail valve fixing portion 58, the communication hole 56A of the fail valve seat member 56, and the fail valve 55 Cylinder lower chamber through opening, center hole 53A of pilot valve second valve portion seat member 53, upstream chamber 51D of pilot valve 51, pilot valve communication passage 52, downstream chamber 51E, first valve portion, communication passage 41G It flows to 2B.

  In this case, in the pilot chamber 42, the upstream side of the communication hole 56 </ b> A communicates with the valve chamber 63, and the downstream side of the fail valve 55 has a relatively low pressure. Of these, a force in the valve closing direction acts on the main valve 41 mainly by the force of the upstream high pressure portion.

  As a result, the pressure in the pilot chamber 42 is applied to the main valve 41 due to the difference in diameter between the outer diameter of the main valve 41 (the diameter of the fourth shaft hole 22 of the piston case 20) and the outer diameter of the operating pin 71. Power works. The pressure in the pilot chamber 42 rises due to the fail valve 55 acting as a relief valve, so that a force in the valve closing direction acts on the main valve 41 and a sufficient damping force can be obtained.

  According to this embodiment, from the cylinder upper chamber 2A (one side chamber) toward the cylinder lower chamber 2B (other side chamber), the introduction communication path 25 having the orifice restrictor (resistance element), the pilot valve unit 50 (valve element), The valve seat 48 is disposed in order along the direction of the pilot flow path from the introduction communication path 25 through the pilot chamber 42 to the communication path 41G of the main valve 41, and the working fluid does not return from the cylinder upper chamber 2A to the cylinder lower chamber. Since the flow is unidirectional toward 2B, noise vibration accompanying a change in the flow of the working fluid can be suppressed as much as possible.

  In addition, it has a configuration that can generate a predetermined damping force even during a failure, and the flow between the upper chamber and the lower chamber of the piston does not bend more than necessary, so the loss is small and it is not likely to cause sound vibration. It can be set as a damping force adjustment type shock absorber.

  In the present embodiment, an example in which the fail valve 55 is constituted by a disk-shaped spring as shown in FIG. 8 is shown. However, if the flow of hydraulic oil does not change, a ball valve and a spring that urges the valve in the closing direction are used. It may be a ball valve type valve formed.

  Moreover, the seat part 62 of the pilot valve 51 may be formed in a tapered shape as in the modification shown in FIG. In this case, the flow of the first valve portion has a shape along the taper, the flow collision is less likely to occur, and the generation of vibration noise can be suppressed. Similarly, although not shown, the same effect can be obtained even if the valve seat 48 side is tapered.

  The pilot flow path from the introduction communication path 25 through the pilot chamber 42 to the communication path 41G of the main valve 41 is between the introduction communication path 25 and the contact portion with the valve seat 48 in the pilot valve portion 50. And a first flow path formed including a first vector parallel to the arrangement direction of the cylinder upper chamber 2A and the cylinder lower chamber 2B, and perpendicular to the arrangement direction of the cylinder upper chamber 2A and the cylinder lower chamber 2B. In view of the above, it is desirable to form the first flow path so as not to overlap with the other flow paths. In other words, it is desirable that a flow path (return flow path for the working fluid) of a vector parallel to the arrangement direction of the cylinder lower chamber 2B and the cylinder upper chamber 2A (a vector in a direction opposite to the first vector) is not formed. .

  Further, it is more desirable that the angle of the bent portion of the pilot flow path from the introduction communication path 25 to the contact portion of the pilot valve portion 50 with the valve seat 48 is 90 degrees or an obtuse angle.

  Further, the component in the direction perpendicular to the arrangement direction of the cylinder upper chamber 2 </ b> A and the cylinder lower chamber 2 </ b> B of the first flow path is from the introduction communication path 25 to the contact portion of the pilot valve portion 50 with the valve seat 48. In the cylinder 2, it is desirable that the flow be in one direction from the outside to the inside. In either case, the return portion for the flow of the working fluid is not provided.

  Next, a damping force adjustment type shock absorber according to a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the configuration of the pilot valve unit 50 is different from that of the first embodiment, and the other configuration is the same as that of the first embodiment. Therefore, the description which overlaps with Example 1 is abbreviate | omitted in the following description. FIG. 11 shows a normal operation state, and FIG. 12 shows a fail operation state.

  The configuration of the pilot valve unit 50 of the present embodiment will be described. The pilot valve section 50 includes a pilot valve second valve section seat member 153 disposed on the upper surface of the step section 41F of the main valve 41, a pilot valve 51 disposed inside the small diameter section 41C of the main valve 41, and the pilot valve 51 at the lower end. It comprises a fixed operating pin 71, a fail spring 59 acting in the valve opening direction, a pilot spring 61, and a linear solenoid 70.

  FIG. 13 shows the shape of the pilot valve second valve portion seat member 153, which will be described with reference to this also. As shown in FIG. 13, the pilot valve second valve portion seat member 153 is formed in a disc shape having a central hole 153A provided at the center thereof, and the tip of the annular convex portion 51B of the pilot valve 51 is formed on the disc portion. A second valve portion that opens and closes the flow path of the communication passage 41 </ b> B (see FIG. 4) provided in the main valve 41 by contacting and separating is formed. A space 153B is provided between the outer diameter side and the large diameter portion 41D of the main valve 41. The diameter of the center hole 153A is larger than the outer diameter of the operating pin 71, and a throttle passage 155 is formed therebetween, which acts as a flow path resistance. The pilot valve second valve portion seat member 153 is fixedly disposed on the main valve 41.

  A valve chamber 63 is formed inside the fourth shaft hole 22 and the annular convex portion 29 (see FIG. 2) of the piston case 20 and above the pilot valve second valve portion seat member 153. The valve chamber 63 communicates with the piston upper chamber 2A through an introduction communication passage 25 (see FIG. 2) provided in the piston case 20. The introduction communication path 25 is configured by a resistance element that generates flow path resistance due to an orifice restriction or the like. The valve chamber 63 communicates with a groove 41A provided in the main valve 41 through a communication passage (space) 153B provided on the outer edge side of the pilot valve second valve portion seat member 153, and further through the communication passage 41B. The small diameter portion 41C of the valve 41 communicates. Further, when the second valve portion of the pilot valve 51 is open, the pilot valve 51 communicates with the upstream chamber 51D, the communication passage 52, and the downstream chamber 51E. The pilot chamber 42 of the main valve 41 is formed in the chambers from the valve chamber 63 to the downstream chamber 51E.

  Other configurations are the same as those in the first embodiment. A specific operation of the damping force adjusting shock absorber according to this embodiment having the above-described configuration will be described. First, the operation in the normal state will be described with reference to FIG.

  During the normal operation, the damping force generation mechanism 7 can adjust the thrust (control current) of the linear solenoid 70 to control the force acting on the main valve 41, so that the damping force can be variably adjusted.

  During the extension stroke of the piston rod 6, the hydraulic oil on the cylinder upper chamber 2 </ b> A side is pressurized by the movement of the piston 5 in the cylinder 2.

  The flow of hydraulic oil when a current is applied to the linear solenoid 70 will be described. The hydraulic fluid from the cylinder upper chamber 2A flows upstream of the introduction communication passage 25, the valve chamber 63, the communication passage 53B, the groove portion 41A of the main valve 41, the communication passage 41B, and the pilot valve 51 as shown by the flow of F1 shown in FIG. It flows to the cylinder lower chamber 2B through 51D, the pilot valve communication passage 52, the downstream chamber 51E, the first valve portion, and the communication passage 41G. At the same time, as indicated by the dotted line, the flow from the valve chamber 63 also flows through the throttle passage 155 to the upstream chamber 51D of the pilot valve.

As in the first embodiment, the pressure of the pilot chamber 42 is controlled by controlling the thrust of the linear solenoid 70, and the damping force can be controlled.
Next, the fail operation state when the control current is cut off due to the disconnection of the coil of the linear solenoid 70, the failure of the control device, or waiting for a signal will be described with reference to FIG.

  When the control current to the linear solenoid 70 is interrupted, the thrust of the plunger 73 and the operating pin 71 disappears, so that the pilot valve 51 moves away from the valve seat 48 provided on the main valve 41 by the spring force of the fail spring 59. Move to. As a result, the seat portion 62 of the first valve portion of the pilot valve 51 is disengaged from the valve seat 48 provided on the main valve 41, and the first valve portion of the pilot valve 51 is opened.

  When the pilot valve 51 moves upward, the second valve portion formed on the annular convex portion 51B of the pilot valve 51 is brought into contact with the pilot valve second valve portion seat member 153, and the second valve portion causes the communication passage 41B ( 4) is closed.

  In this state, the hydraulic oil in the cylinder upper chamber 2A is pressurized in the extension process. From the cylinder upper chamber 2A, through the introduction communication passage 25, the throttle passage 155, the upstream chamber 51D of the pilot valve 51, the pilot valve communication passage 52, the downstream chamber 51E, the first valve portion, and the communication passage 41G, Flows to chamber 2B. Since the flow is restricted by the center hole 153A, the upstream side is the pressure on the downstream side of the introduction communication path 25 and the downstream side is substantially the same pressure as the downstream side of the main valve 41. The upstream valve chamber 63 and the pilot chamber 42 of the main valve 41 are formed upstream of the center hole 153A.

  As a result, the pressure in the pilot chamber 42 is applied to the main valve 41 due to the difference in diameter between the outer diameter of the main valve 41 (the diameter of the fourth shaft hole 22 of the piston case 20) and the outer diameter of the operating pin 71. Power works. The pressure in the pilot chamber 42 rises due to the central hole 153A acting as a throttle, so that a force acts on the main valve 41 in the valve closing direction and a sufficient damping force can be obtained.

  According to the present invention, the same effects as those of the first embodiment can be obtained, and the number of parts can be further reduced, so that the cost can be reduced.

  Next, with reference to FIG. 14 and FIG. 15, a damping force adjusting type shock absorber according to a third embodiment of the present invention will be described. In this embodiment, the pilot valve unit 50 is configured as a normally closed type, and other configurations are the same as those in the first embodiment. Therefore, the description which overlaps with Example 1 is abbreviate | omitted in the following description. FIG. 14 shows a fail operation state.

  The structure of the main valve 41 of this embodiment will be described. The main valve 41 of the present embodiment is different from the first and second embodiments in that it does not have a structure such as a groove and a communication path.

  The main valve 41 is formed in a substantially bottomed cylindrical shape having a recess. At the lower end of the main valve 41, a flange portion 41H (outer flange) is formed. On the lower end surface of the flange portion 41H of the main valve 41, an annular seat portion 39 that is separated from and seated on the valve seat 38 of the valve seat member 31 is formed.

  When the seat portion 39 is seated on the valve seat 38 of the valve seat member 31, an annular chamber 84 is formed between the lower end portion of the piston case 20, the valve seat member 31, and the main valve 41. A plurality of passages 34 communicating the annular chamber 84 and the cylinder upper chamber 2A are provided at the lower end of the piston case 20.

  The main valve 41 has a cylindrical outer peripheral surface 88 slidably inserted into the fourth shaft hole 22 of the piston case 20, and an outer peripheral surface of the flange portion 41 H slides into the third shaft hole 26 of the piston case 20. Inserted as possible. Thereby, an annular back pressure chamber 46 is formed between the main valve 41 and the third shaft hole 26.

  A valve seat 48 is provided at the bottom of the concave portion of the main valve 41, from which an annular seat portion 62 formed on the pilot valve 51 described later is detached and seated. Further, a communication passage 41G communicating with the cylinder lower chamber 2B is provided inside the valve seat 48.

  On the upper end side of the main valve 41, a compression coil spring 65 that applies a set load is installed between the piston case 20. As a result, the piston case 20 is urged downward, that is, urged in the valve closing direction.

  Next, the configuration of the pilot valve unit 50 will be described. The pilot valve unit 50 includes a pilot valve 51 disposed inside the recess of the main valve 41, an operating pin 71 for fixing the pilot valve 51 to the lower end, a pilot spring 61 acting in the valve closing direction, and a linear solenoid 70. .

  The pilot valve 51 has a substantially cylindrical bottom shape, and has a center hole 51C having a bottom at the center of the cylinder, and a communication hole 51G communicating from the bottom part to the lower part, and a seat part 62 is formed at the lower part of the cylinder. The outer diameter of the cylinder is set smaller than the inner diameter of the recess of the main valve 41. The seat portion 62 is formed to have a “pilot valve portion” that can open and close a flow path between the seat portion 62 and the valve seat portion 48 formed in the main valve 41. The diameter of the seat portion 62 is set smaller than the outer diameter of the operating pin 71, and a force acts in the direction of opening the pilot valve portion due to the pressure of the valve chamber 63.

  With the above configuration, the valve chamber 63 formed above the valve seat portion 48 functions as a pilot chamber of the main valve 41. In addition, an introduction communication path 25 is provided between the valve chamber 63 and the piston upper chamber 2A, and an orifice serving as a flow path resistance is provided as necessary.

  A pilot spring 61 of a compression coil spring is disposed between the upper end of the pilot valve 51 and the annular convex portion of the main valve 41, and acts in the direction in which the pilot valve portion is closed.

  Further, the plunger of the linear solenoid 70 is fixed to the operating pin 71 and is arranged so that a force is generated upward in the figure, that is, in a direction to open the pilot valve portion when a current is applied. That is, the pilot valve unit 50 is configured as a normally closed valve.

  A specific operation of the damping force adjusting shock absorber according to the present embodiment having the above-described configuration will be described.

  First, the operation in the normal state will be described. During normal operation, the damping force generation mechanism 7 variably adjusts the damping force by changing the pressure in the pilot chamber of the main valve 41 during the expansion stroke of the piston rod 6, while on the other hand, during the contraction stroke of the piston rod 6. The damping force can be variably adjusted by adjusting the thrust (control current) of the linear solenoid 70.

  During the extension stroke of the piston rod 6, the hydraulic oil on the cylinder upper chamber 2 </ b> A side is pressurized by the movement of the piston 5 in the cylinder 2.

  The flow of hydraulic oil when a current is applied to the linear solenoid 70 will be described. The hydraulic oil from the cylinder upper chamber 2A flows to the cylinder lower chamber 2B through the introduction communication passage 25, the valve chamber 63, the pilot valve portion, and the center hole 41G of the main valve 41 as shown by the flow of F1 shown in FIG.

  As in the first and second embodiments, by controlling the thrust of the linear solenoid 72, the pressure in the valve chamber 63 serving as the pilot chamber is controlled, and the damping force can be controlled.

  Next, the fail operation state when the control current is cut off due to disconnection of the coil of the linear solenoid 70, failure of the control device, or waiting for a signal will be described with reference to FIG.

  When the control current to the linear solenoid 70 is cut off, the thrust of the plunger 73 and the operating pin 71 disappears, so the pilot valve 51 closes the valve seat 48 provided on the main valve 41 by the spring force of the pilot spring 61. Move to. As a result, the seat portion 62 of the first valve portion of the pilot valve 51 is seated on the valve seat 48 provided in the main valve 41, and the pilot valve portion is closed.

  In this state, the hydraulic oil in the cylinder upper chamber 2A is pressurized in the extension process. Then, oil flows from the cylinder upper chamber 2 </ b> A to the introduction communication passage 25 and the valve chamber 63. Thereby, when the force in the valve opening direction of the pilot valve portion due to the pressure of the valve chamber 63 overcomes the valve closing direction by the pilot spring 61, the valve opens, and the oil flows through the communication passage 41G to the cylinder lower chamber 2B.

  The upstream valve chamber 63 functions as the pilot chamber 42 of the main valve 41. When a flow occurs, the pressure of the valve chamber 63 increases. A force acts in the valve closing direction due to the difference in diameter from the outer diameter. A force acts on the main valve 41 in the valve closing direction, and a sufficient damping force can be obtained.

  According to the configuration of the present embodiment, the pilot valve 51 can be a normally closed valve, and the same effect as in the first and second embodiments can be obtained, and the fail valve and the throttle portion can be eliminated. Since the number of parts is further reduced, a low-cost structure can be obtained.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Shock absorber (damping force adjustment type shock absorber), 2 ... Cylinder, 4 ... Reservoir, 5 ... Piston, 6 ... Piston rod, 7 ... Damping force generating mechanism, 10 ... Base valve, 20 ... Piston case, 25 ... Introduction Communicating passageway 31 ... Valve seat member 40 ... Main valve part 41 ... Main valve 50 ... Pilot valve part 51 ... Pilot valve 53 ... Pilot valve second valve part seat member 55 ... Fail valve 56 ... Fail Valve seat member, 63 ... valve chamber, 70 ... linear solenoid, 73 ... plunger.

Claims (12)

A cylinder filled with a working fluid;
A piston that is slidably fitted in the cylinder, and divides the inside of the cylinder into one side chamber and another side chamber;
A piston rod having one end connected to the piston and the other end extending outside the cylinder;
A damping force adjustment type shock absorber provided with the piston, and a damping valve mechanism that generates a damping force by controlling the flow of the working fluid from the one side chamber to the other side chamber by the movement of the piston,
The damping valve mechanism includes a main valve that regulates a flow of working fluid from the one side chamber to the other side chamber;
A pilot chamber for urging the main valve in the valve closing direction;
An introduction path resistance element that restricts the flow of the working fluid in the one side chamber and guides it to the pilot chamber;
A control valve capable of adjusting the pressure in the pilot chamber by controlling the flow of the working fluid flowing into the pilot chamber through the introduction path resistance element to the other chamber;
The control valve includes a linear solenoid,
A mover driven in the axial direction of the piston by the linear solenoid;
A valve body provided at one end of the mover;
The valve body is seated, and has a valve seat that opens and closes a communication passage communicating the pilot chamber and the other side chamber,
From the one side chamber toward the other side chamber, the introduction path resistance element, the valve body, and the valve seat are arranged in this order, and the working fluid flows in one direction without returning from the one side chamber toward the other side chamber. A damping force adjusting type shock absorber. The damping force adjustable shock absorber according to claim 1,
The piston and the main valve form a flow path space connecting the one side chamber and the other side chamber,
The flow path space is formed including a first vector parallel to the arrangement direction of the one side chamber and the other side chamber between the introduction path resistance element and a contact portion of the valve body with the valve seat. Having a first flow path,
When viewed from a direction perpendicular to the arrangement direction, the flow path space is formed so that the first flow path does not overlap with another flow path. The damping force adjustment type shock absorber according to claim 1 or 2,
The piston and the main valve form a flow path space connecting the one side chamber and the other side chamber,
Damping force adjustable shock absorber characterized in that the flow path space has an angle of a bent portion between the introduction path resistance element and the contact portion of the valve body with the valve seat being 90 degrees or an obtuse angle. . The damping force adjustment type shock absorber according to claim 2,
The piston and the main valve form a flow path space connecting the one side chamber and the other side chamber,
The flow path space is between the introduction path resistance element and the contact portion of the valve body with the valve seat, and a component perpendicular to the arrangement direction of the first flow path is outside in the cylinder. Damping force adjustable shock absorber characterized by a unidirectional flow from the inside to the inside. The damping force adjustment type shock absorber according to any one of claims 1 to 4,
The damping force adjustable shock absorber, wherein the control valve is a normally open valve that opens when the linear solenoid is not energized. The damping force adjustment type shock absorber according to claim 5,
The control valve includes an urging means for urging the valve body in a valve opening direction,
A valve chamber for accommodating the valve body in the pilot chamber;
The valve body divides the valve chamber into an upstream chamber and a downstream chamber,
An inflow passage opening and closing portion for opening and closing an inflow passage from the upstream side of the pilot chamber to the upstream chamber,
A fail passage that bypasses the inflow passage opening and closing portion and communicates the upstream side of the pilot chamber and the upstream chamber;
A damping force adjusting shock absorber comprising: a fail valve body that opens and closes the fail passage. The damping force adjustment type shock absorber according to claim 6,
The valve body has a communication path that connects the upstream chamber and the downstream chamber, and a damping force adjusting type shock absorber. The damping force adjustable shock absorber according to claim 6 or 7,
The damping valve with adjustable damping force, wherein the fail valve body is a disk valve. The damping force adjustable shock absorber according to claim 6 or 7,
The damping valve according to claim 1, wherein the fail valve body is a ball valve. The damping force adjustment type shock absorber according to claim 5,
The control valve includes an urging means for urging the valve body in a valve opening direction,
A valve chamber for accommodating the valve body in the pilot chamber;
The valve body divides the valve chamber into an upstream chamber and a downstream chamber,
An inflow passage opening and closing portion for opening and closing an inflow passage from the upstream side of the pilot chamber to the upstream chamber,
A fail passage that bypasses the inflow passage opening and closing portion and communicates the upstream side of the pilot chamber and the upstream chamber;
And a resistance element that restricts the flow of the fail passage. It is a damping-force adjustment type shock absorber according to any one of claims 1 to 10,
A damping force adjusting type shock absorber, wherein a seating surface of the valve body with the valve seat or a seating surface of the valve seat with the valve body is tapered. The damping force adjustment type shock absorber according to any one of claims 1 to 11,
The main valve has a substantially bottomed cylindrical shape having a recess that constitutes a part of the pilot chamber.

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