WO2017145983A1

WO2017145983A1 - Damping force-adjusting shock absorber

Info

Publication number: WO2017145983A1
Application number: PCT/JP2017/006130
Authority: WO
Inventors: 村上　裕; 山岡　史之
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2016-02-24
Filing date: 2017-02-20
Publication date: 2017-08-31
Also published as: JPWO2017145983A1; JP6516916B2

Abstract

Provided is a damping force-adjusting shock absorber with which stable damping force is obtained even in an ultra-low piston speed range. A second valve body 82 with a smaller diameter than a first valve body 81 is interposed between the first valve body 81 and subvalve bodies. It is thereby possible to reduce the area of contact between a main valve body (second valve body 82) and a subvalve body (second disc 84) when the main valve bodies (first valve body 81 and second valve body 82) are opened. As a result, it is possible to inhibit sticking between the main valve bodies and the subvalve bodies and obtain a stable damping force.

Description

Damping force adjustable shock absorber

The present invention relates to a damping force adjusting type shock absorber that generates a damping force by controlling a flow of a working fluid with respect to a stroke of a piston rod.

Some shock absorbers having good damping force characteristics form a back pressure chamber by laminating a plurality of disk valves having openings in a valve member engaged with a piston rod. (For example, Patent Document 1)

JP 2014-194259 A

In the damping force adjusting type shock absorber, it is desired to obtain better damping force characteristics. Accordingly, an object of the present invention is to provide a damping force adjusting type shock absorber capable of obtaining a good damping force characteristic.

A damping force adjusting shock absorber according to an embodiment of the present invention includes a cylinder in which a working fluid is sealed, a piston slidably fitted in the cylinder, a piston connected to the piston, and an outside of the cylinder. A main body valve that controls the flow of working fluid generated by sliding of the piston in the cylinder to generate a damping force, and a pressure in the valve closing direction is applied to the main valve. A damping force adjusting type shock absorber comprising: a pilot chamber; a pilot passage communicating the pilot chamber with an upstream passage of the main valve; and a control valve provided in the pilot passage. , A passage through which the fluid in the cylinder flows, a valve seat member having a seat portion formed outside a downstream opening of the passage, and a seat on the seat portion A sub-valve element that opens and closes the downstream opening of the passage, and a main valve element that is provided on the opposite side of the valve seat member of the sub-valve element, A first disk having a first opening with a peripheral side sandwiched and an outer peripheral side seated on the seat portion; and a second disk having a second opening sandwiched on an inner peripheral side and communicating with the first opening; The first opening has an opening area for restricting the flow of fluid flowing through the passage of the main valve, the second opening has an opening area larger than the first opening, and an outer periphery of the main valve body A pressure chamber is formed to open the main valve body by separating the side from the second disk, and the main valve body is sandwiched on the inner peripheral side and the packing fixed to the outer peripheral side on the back surface is attached to the pilot member. To slidably contact the pilot chamber A first valve body to be closed, a second valve body interposed between the first valve body and the second disk, closing the second opening, and having a smaller diameter than the first valve body, It is characterized by including.

According to the damping force adjustment type shock absorber according to one embodiment of the present invention, a good damping force characteristic can be obtained.

It is sectional drawing by the uniaxial plane of the damping force adjustment type buffer which concerns on 1st Embodiment. It is explanatory drawing of 1st Embodiment, Comprising: It is a figure which expands and shows the principal part (damping force generation | occurrence | production mechanism) of FIG. It is explanatory drawing of 1st Embodiment, Comprising: It is a figure which expands and shows the principal part (valve body) of FIG. It is explanatory drawing of 1st Embodiment, Comprising: It is a figure which shows the structure of a main valve body and a subvalve body. It is explanatory drawing of 1st Embodiment, Comprising: It is a graph which shows the relationship between piston speed and damping force. It is explanatory drawing of 2nd Embodiment, Comprising: It is a figure corresponding to FIG. It is explanatory drawing of 2nd Embodiment, Comprising: It is a figure which shows the structure of a main valve body and a subvalve body.

A first embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, the vertical direction in FIG. 1 is referred to as the vertical direction as it is.
As shown in FIG. 1, the damping force adjustment type shock absorber 1 has a double cylinder structure in which an outer cylinder 3 is provided outside a cylinder 2, and a reservoir 4 is formed between the cylinder 2 and the outer cylinder 3. Is done. A piston 5 is slidably fitted into the cylinder 2, and the piston 5 divides the inside of the cylinder 2 into two chambers, a cylinder upper chamber 2A and a cylinder lower chamber 2B. One end of a piston rod 6 is connected to the piston 5 by a nut 7, and the other end side of the piston rod 6 passes through the cylinder upper chamber 2 A, and is further attached to the upper ends of the cylinder 2 and the outer cylinder 3. 8 and the oil seal 9 are extended to the outside of the cylinder 2.

A base valve 10 that separates the cylinder lower chamber 2B and the reservoir 4 is provided at the lower end of the cylinder 2. The piston 5 is provided with

passages

11 and 12 communicating between the cylinder upper chamber 2A and the cylinder lower chamber 2B. The passage 12 is provided with a check valve 13 that allows only fluid (working fluid) to flow from the cylinder lower chamber 2B side to the cylinder upper chamber 2A side. Further, the passage 11 is provided with a disk valve 14 that opens when the pressure of the oil liquid on the cylinder upper chamber 2A side reaches the set pressure and relieves the pressure to the cylinder lower chamber 2B side.

The base valve 10 is provided with

passages

15 and 16 communicating the cylinder lower chamber 2B and the reservoir 4. The passage 15 is provided with a check valve 17 that allows only fluid to flow from the reservoir 4 side to the cylinder lower chamber 2B side. The passage 16 is provided with a disk valve 18 that opens when the pressure of the oil on the cylinder lower chamber 2B side reaches a predetermined pressure and relieves the pressure to the reservoir 4 side. Note that as the working fluid, an oil liquid is sealed in the cylinder 2, and an oil liquid and a gas are sealed in the reservoir 4.

The separator tube 20 is externally fitted to the cylinder 2 via seal members 19 at both ends in the vertical direction, and an annular passage 21 is formed between the cylinder 2 and the separator tube 20. The annular passage 21 is communicated with the cylinder upper chamber 2 A through a passage 22 provided in a side wall near the upper end of the cylinder 2. A cylindrical branch pipe 23 that protrudes laterally (to the right in FIG. 1) is formed at the lower portion of the separator tube 20. An opening 24 that is concentric with the branch pipe 23 and larger in diameter than the branch pipe 23 is provided on the side wall of the outer cylinder 3, and a cylindrical valve case 25 is joined by welding or the like so as to surround the opening 24. A damping force generation mechanism 31 is accommodated in the valve case 25.

(Damping Force Generation Mechanism) As shown in FIG. 1, the damping force generation mechanism 31 has a base end side (left end side in FIG. 1) interposed between the reservoir 4 and the annular passage 21, and a tip end side (FIG. 1 is provided so as to protrude radially outward (rightward in FIG. 1) from the outer cylinder 3. The damping force generation mechanism 31 generates a damping force by controlling the flow of the oil liquid from the annular passage 21 to the reservoir 4 by the main valve 32. Further, the damping force to be generated is variably adjusted by adjusting the valve opening pressure of the main valve 32 with a solenoid 33 applied as a damping force variable actuator.

As shown in FIG. 2, the damping force generation mechanism 31 has the above-described valve case 25 and the base end side (left end side in FIG. 2) fixed to the branch pipe 23 of the separator tube 20, and the tip end side (FIG. 2). The annular flange portion 34A formed on the right end side of the passage member 34 is disposed in contact with the inner flange portion 25A on the proximal end side of the valve case 25 with a gap and the flange portion 34A of the passage member 34. And a valve member 35 (valve seat member) in contact therewith. A threaded portion 39 is formed on the distal end side of the valve case 25, and the valve case 25 and the case member 71 of the solenoid 33 are coupled by a nut 38 screwed into the threaded portion 39. An annular passage 40 communicating with the reservoir 4 is formed between the inner peripheral surface of the valve case 25 and the main valve 32.

Inside the passage member 34, a passage 41 (upstream passage of the main valve 32) is formed, one of which communicates with the annular passage 21 and the other extends to the valve member 35. An annular spacer 42 is sandwiched between the flange portion 34 A of the passage member 34 and the inner flange portion 25 A of the valve case 25. In the spacer 42, a plurality of passages 43 (only two are shown in FIG. 2) communicating the passage 40 and the reservoir 4 are formed. Instead of the spacer 42, the flange portion 34A may be arranged directly on the inner flange portion 25A on the proximal end side of the valve case 25. In that case, a plurality of passages that connect the passage 40 and the reservoir 4 to the inner flange portion 25A are formed by cutting or the like.

The valve member 35 has a plurality of passages 44 (only two are shown in FIG. 2) provided in a circumferentially spaced manner around the shaft hole 35A. Each passage 44 communicates with the passage 41 of the passage member 34 on one side (left side in FIG. 2). Further, on the other end face (right side in FIG. 2) of the valve member 35, an annular recess 35B opened on the other side (right side in FIG. 2) of the passage 44, and a radially outer side of the annular recess 35B, that is, a passage. An annular seat portion 46 formed outside the downstream opening 44 and on which a sub-valve element described later is seated is provided. Then, the passage 44 of the valve member 35 circulates oil through the passage 41 on the annular passage 21 side and the passage 40 on the reservoir 4 side via a sub valve body or a main valve body described later.

(Sub-valve element) Referring to FIGS. 3 and 4, the sub-valve element includes a first disk 83 and a second disk 84. The first disc 83 and the second disc 84 are sandwiched between a boss portion 35C of the valve member 35 and a flange portion 47A of a pilot pin 47 described later on the inner peripheral side (lower side in FIG. 3). The first disk 83 has a shaft hole 83A through which the pilot pin 47 is inserted. Further, the first disk 83 has a first opening 85 formed in an opening area that restricts the oil (fluid) flowing through the main valve 32, that is, restricts the oil flowing through the passage 44 of the valve member 35. The first disk 83 has a plurality (three in the first embodiment) of first openings 85 arranged at equal intervals on a circle concentric with the shaft hole 83A. The first disk 83 is seated on the seat portion 46 of the valve member 35 on the outer peripheral side (the upper side in FIG. 3).

The second disc 84 is provided so as to overlap the back side of the first disc 83, that is, the side opposite to the side seated on the seat portion 46. The second disk 84 has a larger outer diameter and plate thickness than the first disk 83. The second disk 84 is connected by a plurality of (three in the first embodiment) stays 88 extending in the disk radial direction, the outer peripheral part 86 and the inner peripheral part 87 being arranged at equal intervals around the shaft hole 84A. Is done. The second disk 84 has a plurality of (three in the first embodiment) second openings 89 defined by the outer peripheral portion 86, the inner peripheral portion 87, and the adjacent stays 88. In other words, three second openings 89 are provided around the shaft hole 84A. The second opening 89 has an opening area larger than that of the first opening 85 and communicates with the corresponding first opening 85.

(Main valve body) On the other hand, the main valve body includes a first valve body 81 and a second valve body 82. The first valve body 81, together with the first disk 83 and the second disk 84, has an inner peripheral side (lower side in FIG. 3) between a boss part 35 C of the valve member 35 and a flange part 47 A of a pilot pin 47 described later. It is pinched at. The first valve body 81 has the same diameter as the outer diameter of the second disk 84 and is provided on the back side of the second disk, in other words, on the side opposite to the valve member 35 (valve seat member) of the sub-valve body. It is done. Moreover, the 1st valve body 81 is what is called a packing valve, and the packing 90 is fixed to the outer peripheral side of a back surface. And the 1st valve body 81 demarcates the back pressure chamber 52 (pilot chamber) by making the packing 90 slidably contact | abuts to the internal peripheral surface of protrusion cylinder part 50D of the pilot body 50 (pilot member). (Block). That is, the back pressure chamber 52 (pilot chamber) forms a pilot body 50 (pilot member).

On the other hand, the second valve element 82 is interposed between the first valve element 81 and the sub-valve element (second disc 84). Further, the second valve body 82 has an outer diameter (small diameter) and a plate thickness smaller than those of the first valve body 81, and closes each second opening 89 of the second disk 84. Thereby, a plurality (three in the first embodiment) of pressure chambers 91 defined by the respective second openings are formed between the second valve body 82 and the sub-valve body (second disk 84). The Each pressure chamber 91 communicates with the annular passage 21 via each corresponding first opening 85 of the first disk 83, each passage 44 of the valve member 35, and the passage 41 of the passage member 34. Note that

spacers

92, 93, 94 and a spacer 95 are interposed between the first valve body 81 and the flange portion 47 A of the pilot pin 47. Here, the spacer 92 adjacent to the first valve body 81 has a smaller diameter than the

other spacers

93, 94, 95.

The first valve body 81 is separated from the second disc 84 together with the second valve body 82 when the second valve body 82 receives the pressure of each pressure chamber 91. As a result, the passage 44 (annular passage 21) of the valve member 35 is communicated with the passage 40 (reservoir 4), and the damping force of the valve characteristic by the main valve body is obtained. In this case, the second disk 84 functions as a valve seat for the main valve body. On the other hand, when the piston speed, that is, the moving speed of the piston rod 6 reaches a constant speed, the sub-valve bodies (the first disk 83 and the second disk 84) are separated from the seat portion 46. Thereby, the passage 44 (annular passage 21) of the valve member 35 is directly communicated with the passage 40 (reservoir 4), and the damping force of the valve characteristic by the sub-valve element is obtained.

(Pilot Valve) As shown in FIG. 2, the pilot pin 47 is formed in a cylindrical shape having a flange portion 47A at an axially intermediate portion, and an orifice 49 is provided at one end (left end in FIG. 2) of the shaft hole 47B. Is formed. One end of the pilot pin 47 is press-fitted into the shaft hole 35 A of the valve member 35, and the other end (the right end in FIG. 2) is fitted into the shaft hole 50 A of the pilot body 50. In this state, a passage 51 extending in the axial direction is formed between the shaft hole 50 A of the pilot body 50 and the other end side of the pilot pin 47. The passage 51 is connected to a back pressure chamber 52 formed between the main valve body (first valve body 81) and the pilot body 50.

The pilot body 50 is formed in a bottomed cylindrical shape having a cylindrical portion 50B in which a stepped hole is formed inside and a bottom portion 50C that closes the cylindrical portion 50B, and the other end of the pilot pin 47 is formed on the bottom portion 50C. A shaft hole 50A to be fitted is formed. On one end side (left side in FIG. 2) of the bottom portion 50C of the pilot body 50, a protruding cylinder portion 50D that protrudes to the valve member 35 side (left side in FIG. 2) is formed. The packing 90 of the first valve body 81 is fluid-tightly fitted to the inner peripheral surface of the protruding cylinder portion 50D, and the back pressure chamber 52 described above is interposed between the first valve body 81 and the pilot body 50. It is formed. The internal pressure of the back pressure chamber 52 is the valve closing direction with respect to the main valve body, that is, the direction in which the first valve body 81 is pressed against the second valve body 82, and the sub-valve body in the seat portion 46 of the valve member 35. Acts in the direction of seating.

A seat portion 54 is formed at the center of the other side (right side in FIG. 2) of the bottom portion 50C of the pilot body 50 so as to surround the shaft hole 50A and on which the pilot valve member 53 is seated. Further, inside the cylindrical portion 50B of the pilot body 50, when the return spring 55 and the solenoid 33 that urges the pilot valve member 53 in a direction away from the seat portion 54 of the pilot body 50 are in a non-energized state (the pilot valve member 53 A disc valve 56 constituting a fail-safe valve (when it is farthest from the seat portion 54), a holding plate 57 in which a passage 57A is formed, and the like.

A cap 58 is fitted and fixed to the open end of the cylindrical portion 50B of the pilot body 50 with a return spring 55, a disk valve 56, a holding plate 57, and the like provided inside the cylindrical portion 50B. . The cap 58 is formed with a passage 59 serving as a flow path for flowing the oil liquid flowing to the solenoid 33 side through the passage 57A of the holding plate 57 to the passage 40 (reservoir 4 side). The passage 59 is provided at, for example, four locations in the circumferential direction.

The pilot valve member 53 constitutes a pilot valve together with the pilot body 50. The pilot valve member 53 is formed in a cylindrical shape, and a tip end portion that is attached to and detached from the seat portion 54 of the pilot body 50 is formed in a tapered shape. One end of the operating pin 69 of the solenoid 33 is fitted and fixed inside the pilot valve member 53, and the valve opening pressure of the pilot valve member 53 is adjusted according to the energization of the solenoid 33. Further, on the base end side (right end side in FIG. 2) of the pilot valve member 53, a flange portion 53A that functions as a spring support is formed over the entire circumference. When the solenoid 33 is in a non-energized state, that is, when the pilot valve member 53 is farthest from the seat portion 54, the flange portion 53 A functions as a seat portion that contacts the disc valve 56 and constitutes a fail-safe valve. .

(Solenoid) As shown in FIG. 2, the solenoid 33 includes a coil case 61 and the case member 71 described above. The coil case 61 is formed in a cylindrical shape by molding the coil 61 A and the core 62, and the cable 63 is connected to the coil case 61. The coil 61 A generates a magnetic force by power supply (energization) through the cable 63. The core 62 is formed of a member made of a magnetic material.

The operating pin 69 is supported by a bush 78 incorporated in the stator core 73 and a bush 79 incorporated in the core 74 so as to be movable in the axial direction (left-right direction in FIG. 2). A plunger 75 is coupled to the outer peripheral surface of the operating pin 69. The plunger 75 referred to as a movable iron core is formed in a cylindrical shape by, for example, an iron-based magnetic material, and is energized by the coil 61A to generate a magnetic force, thereby being attracted to the core 74 and generating thrust. When the solenoid 33 is in an energized state, the end of the plunger 75 on the main valve 32 side (left side in FIG. 2) is slidably fitted to the recess 74B of the core 74.

(Operation) Next, the operation of the damping force adjusting shock absorber 1 according to the first embodiment will be described.
The damping force adjusting type shock absorber 1 is mounted between the sprung and unsprung parts of the vehicle suspension device. When the vehicle is traveling, if vibration in the vertical direction occurs due to unevenness on the road surface, the 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 31 applies the damping force. By generating, the vibration of the vehicle is buffered. At this time, the controller controls the current value to the coil 61 A of the solenoid 33 to adjust the valve opening pressure of the pilot valve member 53. Thereby, the damping force generated by the shock absorber 1 can be variably adjusted.

During the extension stroke of the piston rod 6, the check valve 13 of the piston 5 is closed by the movement of the piston 5 in the cylinder 2, and before the disk valve 14 is opened, the oil liquid (working fluid) on the cylinder upper chamber 2 A side is opened. Is pressurized. The pressurized oil liquid passes through the passage 22 and the annular passage 21 and flows from the branch pipe 23 of the separator tube 20 to the passage member 34 of the damping force generation mechanism 31. At this time, the oil liquid corresponding to the movement of the piston 5 flows from the reservoir 4 into the cylinder lower chamber 2B by opening the check valve 17 of the base valve 10. When the pressure in the cylinder upper chamber 2A reaches the valve opening pressure of the disk valve 14 of the piston 5, the disk valve 14 opens and the pressure in the cylinder upper chamber 2A is relieved to the cylinder lower chamber 2B. An excessive increase in pressure in the chamber 2A is prevented.

On the other hand, during the contraction stroke of the piston rod 6, the check valve 13 of the piston 5 opens as the piston 5 moves in the cylinder 2, and the check valve 17 of the passage 15 of the base valve 10 closes. Before the disc valve 18 is opened, the oil in the piston lower chamber 2B flows into the cylinder upper chamber 2A, and the volume of oil that the piston rod 6 has entered into the cylinder 2 flows from the cylinder upper chamber 2A. It circulates to the reservoir 4 through the same route as in the above-described extension stroke. When the pressure in the cylinder lower chamber 2B reaches the valve opening pressure of the disk valve 18 of the base valve 10, the disk valve 18 is opened and the pressure in the cylinder lower chamber 2 B is relieved to the reservoir 4. Thereby, an excessive increase in pressure in the cylinder lower chamber 2B can be prevented.

On the other hand, in the damping force generation mechanism 31, the oil that has flowed into the passage 41 of the passage member 34 is before the main valve body, that is, the first valve body 81 and the second valve body 82 are opened (piston speed low speed region). The pilot valve member 53 is pushed open through the shaft hole 35A of the valve member 35, the shaft hole 47B of the pilot pin 47, and the shaft hole 50A of the pilot body 50, and flows into the pilot body 50. The oil that has flowed into the pilot body 50 passes between the flange 53A of the pilot valve member 53 and the disc valve 56, through the passage 57A of the holding plate 57, the passage 59 of the cap 58, and the passage 40 of the valve case 25. It flows to the reservoir 4.

As the piston speed increases, the pressure in the cylinder upper chamber 2A, and hence the pressure in the passage 41 of the passage member 34, rises. The pressure is transmitted to the pressure chamber 91 formed in the sub-valve body (second disk 84) through the first opening 85. When the pressure in the pressure chamber 91 reaches the valve opening pressure of the main valve body, the main valve body, that is, the first valve body 81 and the second valve body 82 are separated from the sub-valve body (second disk 84). As a result, the oil liquid flows into the reservoir 4 via the passage 41 of the passage member 34, the passage 44 of the valve member 35, and the passage 40 of the valve case 25.

Further, when the piston speed reaches a constant speed (V1 in FIG. 5), the sub valve body, that is, the first disk 83 and the second disk 84 are separated from the seat portion 46 of the valve member 35 and opened. As a result, the oil liquid flows to the reservoir 4 via the passage 41 of the passage member 34, the passage 44 of the valve member 35, and the passage 40 of the valve case 25. As a result, during both the expansion stroke and the contraction stroke of the piston rod 6, before the main valve body and the sub valve body are opened, the damping force is applied by the orifice 49 of the pilot pin 47 and the valve opening pressure of the pilot valve member 53. After the main valve element or the sub-valve element is opened, a damping force corresponding to the opening degree of the valve element can be obtained. In this case, by adjusting the valve opening pressure of the pilot valve member 53 by energizing the coil 61A of the solenoid 33, the damping force can be directly controlled regardless of the piston speed.

Specifically, when the energization current to the coil 61A is reduced to reduce the thrust of the plunger 75, the valve opening pressure of the pilot valve member 53 is reduced, and a soft-side damping force is generated. On the other hand, when the energizing current to the coil 61A is increased to increase the thrust of the plunger 75, the valve opening pressure of the pilot valve member 53 increases and a hard-side damping force is generated. At this time, according to the valve opening pressure of the pilot valve member 53, the internal pressure of the back pressure chamber 52 communicating through the upstream passage 51 changes. In this way, by controlling the valve opening pressure of the pilot valve member 53, the valve opening pressures of the main valve bodies (the first valve body 81 and the second valve body 82) can be adjusted simultaneously, and the damping force The characteristics can be adjusted over a wide range.

Further, when the thrust of the plunger 75 is lost at the time of failure such as disconnection of the coil 61A or failure of the vehicle-mounted controller, the pilot valve member 53 is retracted by the spring force of the return spring 55, and the passage 60 of the pilot body 50 (Pilot passage) is opened, the flange 53A of the pilot valve member 53 is brought into contact with the disc valve 56 (fail-safe disc valve), and the flow path between the valve chamber 67 and the passage 40 in the valve case 25 is closed. . In this state, the flow of the oil liquid from the passage 60 to the passage 40 in the valve case 25 in the valve chamber 67 is controlled by the disc valve 56. Therefore, by adjusting the valve opening pressure of the disc valve 56, A desired damping force can be obtained, and the internal pressure of the back pressure chamber 52, that is, the valve opening pressure of the main valve bodies (the first valve body 81 and the second valve body 82) can be adjusted. As a result, an appropriate damping force can be obtained even during a failure.

(Effect) The damping force adjusting shock absorber 1 according to the first embodiment includes the following configuration.
The main valve 32 is separated from and seated on the seat portion 46 of the valve member 35 (valve seat member) to open and close the downstream opening of the flow path 44 of the valve member 35 (valve seat member), and the sub valve body. And a main valve body provided on the opposite side to the valve member 35.
The sub-valve element includes a first disk 83 formed with a first opening 85 and a second disk 84 formed with a second opening 89 communicating with the first opening 85.
The first opening 85 has an opening area that restricts (limits) the flow of oil (fluid) flowing through the flow path 44 of the valve member 35 (valve seat member).
The second opening 89 has an opening area larger than that of the first opening, and forms a pressure chamber 91 that opens the main valve body away from the sub valve body.
The main valve body includes a first valve body 81 that closes the back pressure chamber 52 (pilot chamber) by slidably contacting the packing 90 fixed to the outer peripheral side of the back surface with the pilot body 50 (pilot member); It includes a second valve element 82 that is interposed between the first valve element 81 and the sub-valve element (second disc 84) and has a smaller diameter than the first valve element 81.

According to the first embodiment, the main valve body (first valve body 81 and second valve body 82) and the sub-valve body (first disk 83 and second disk 84) are stepped by the parallel flow of the oil liquid. In other words, since the inclination of the damping force characteristic (see FIG. 5) before and after the opening of the sub valve body can be changed, the valve opening pressure of the main valve body and the valve opening pressure of the sub valve body Can be adjusted individually, and the damping force generated by the damping force generating mechanism 31 can be adjusted in the very low speed region of the piston speed.
Further, since the outer diameter of the second valve element 82 is made smaller than the outer diameter of the first valve element 81, the main valve element is opened when the sub valve element functions as a valve seat, that is, when the main valve element is opened. The contact area between the valve body (second valve body 82) and the sub-valve body (second disk 84) can be reduced. Thereby, the sticking of the main valve body and the sub-valve body, particularly in a low temperature environment, is suppressed, and it is possible to prevent the deviation of the valve opening timing, the occurrence of abnormal noise, etc. due to the sticking, A stable damping force can be obtained.
In addition, since the pressure chamber 91 for opening the main valve body is formed by stacking the disks (second valve body 82, first disk 83, and second disk 84), the manufacturing is easy and the cost is low. A damping force adjustable shock absorber 1 can be provided.

(Second Embodiment) A second embodiment of the present invention will be described with reference to the accompanying drawings. In addition, about the component which is the same as that of the damping force adjustment type shock absorber 1 which concerns on 1st Embodiment mentioned above, or an equivalent component, the same name and code | symbol are provided, and detailed description is abbreviate | omitted.

Referring to FIGS. 3 and 4 and FIGS. 6 and 7, the first embodiment and the second embodiment are different in the structure of the sub-valve body of the main valve 32. As shown in FIGS. 6 and 7, in the second embodiment, the sub-valve body includes a first disk 83, a second disk 84, a third disk 101, and a fourth disk 102. The second disk 84 applied in the second embodiment is the same as the second disk 84 (see FIG. 4) applied in the first embodiment.

The first disk 83 includes a plurality (five in the second embodiment) of first elongated holes 103 arranged around the shaft hole 83A, and inside each first elongated hole 103 (on the shaft hole 83A side). A plurality of second long holes 104 provided opposite to each other and a plurality of first openings 85 communicating the second long holes 104 opposed to the first long holes 103 at the center. In other words, the first elongated hole 103 is formed on one side of the first disk 85 in the disk radial direction (the side far from the shaft hole 83A) via the first opening 85, and the other side of the first disk 85 in the disk radial direction. A second long hole 104 is formed (on the side close to the shaft hole 83A).

As shown in FIG. 6, each first elongated hole 103 extends in an arc along a circle concentric with the axial hole 83A. Similarly, each second long hole 104 extends in an arc along a circle concentric with the shaft hole 83A. The first opening 85 of the first disk 83 in the second embodiment restricts the oil (fluid) flowing through the main valve 32, that is, has an opening area that restricts the oil flowing through the passage 44 of the valve member 35. It is formed. Further, the width of the first long hole 103 and the second long hole 104, that is, the length in the disk radial direction is the same, and is set larger than the length in the disk radial direction of the first opening 85.

On the other hand, the third disk 101 is formed to have the same diameter as the first disk 83 and is provided to overlap the valve member 35 side (one side) of the first disk 83. That is, the outer periphery of the third disk 101 is in contact (seat) with the seat portion 46 of the valve member 35 (valve seat member). The third disk 101 has a plurality of (four in the second embodiment) third long holes 105 extending in an arc along a circle concentric with the shaft hole 101A. Even if the first disk 83 and the third disk 101 are assembled to the pilot pin 47 at any angle phase, the first long holes 103 of the first disk 83 are not connected to the third disk 101. It communicates with one of the third long holes 105.

On the other hand, the fourth disk 102 is formed to have the same diameter as the second disk 84, and is provided on the back side (the other side) of the first disk 83. That is, the fourth disk 102 is provided so as to overlap the second disk 84 on the side opposite to the second valve element 82. Further, the fourth disk 102 has a plurality (four in the second embodiment) of fourth elongated holes 106 extending in an arc along a circle concentric with the shaft hole 102A.

Even if the first disk 83 and the fourth disk 102 are assembled to the pilot pin 47 at any angular phase, the first long holes 103 of the first disk 83 are not connected to the fourth disk 102. It communicates with one of the fourth long holes 106. Similarly, even if the second disk 84 and the fourth disk 102 are assembled to the pilot pin 47 at any angular phase, the fourth long hole 106 of the fourth disk 102 is formed in the second disk 84. One of the second openings 89 is communicated with.

As a result, as shown in FIG. 6, the sub-valve element has a communication path including the third long hole 105, the first long hole 103, the first opening 85, the second long hole 104, and the fourth long hole 106. 107 is formed. The communication passage 107 communicates the pressure chamber 91 in the sub-valve body with the passage 44 of the valve member 35 (valve seat member). Then, the oil liquid (fluid) flowing through the communication passage 107 toward the pressure chamber 91 flows from the outside in the disk radial direction (vertical direction in FIG. 6) to the inside (downward in FIG. 6). That is, the oil liquid passing through the communication passage 107 flows from the first long hole 103 to the second long hole 104 through the first opening 85.

According to the second embodiment, the same operational effects as those of the first embodiment described above can be obtained. In the first embodiment, when the first disk 83 and the second disk 84 are assembled to the pilot pin 47, the first openings 85 of the first disk 83 are not overlapped with the stays 88 of the second disk 84. In contrast, it is necessary to perform so-called phase alignment. In the second embodiment, such phase alignment is not necessary. Thereby, in 2nd Embodiment, it is possible to improve an assembly | attachment property, Furthermore, the malfunctioning of the damping force adjustment type buffer 1 by an assembly mistake can be prevented.
In the second embodiment, the outer diameter of the fourth disk 102 provided on the opposite side of the second disk 84 from the second disk 84 is the same as the outer diameter of the second disk 84. Compared to the first embodiment in which the first disk 83 having a smaller diameter than the second disk 84 is provided on the opposite side of the second disk 84 from the second valve body 82, the capacity of the pressure chamber 91 is increased. be able to.

In the second embodiment, the oil liquid in the sub-valve flows from the outer side to the inner side in the disk radial direction, that is, the oil liquid passes through the first opening 85 from the first long hole 103 to the second length. The communication passage 107 is formed so as to flow to the hole 104. For example, the third disk 101 and the fourth disk 102 are replaced, and the oil in the sub-valve flows from the inner side to the outer side in the disk radial direction. That is, the communication path 107 can be formed such that the oil liquid flows from the second long hole 104 to the first long hole 103 through the first opening 85.

As the damping force adjustment type shock absorber based on the embodiment described above, for example, the following modes can be considered.
As a first aspect of the damping force adjusting shock absorber, a cylinder in which a working fluid is sealed, a piston slidably fitted in the cylinder, a piston connected to the piston, and extending to the outside of the cylinder. A piston rod that exits, a main valve that generates a damping force by controlling the flow of working fluid generated by sliding of the piston in the cylinder, and a pilot chamber that applies pressure in the valve closing direction to the main valve A damping force adjusting shock absorber comprising: a pilot passage communicating the pilot chamber and an upstream passage of the main valve; and a control valve provided in the pilot passage, A passage through which a fluid in the cylinder flows, a valve seat member having a seat portion formed outside a downstream opening of the passage, and a seat on the seat portion. A sub-valve element that opens and closes the downstream opening of the passage, and a main valve element that is provided on the opposite side of the valve seat member of the sub-valve element, and the inner side of the sub-valve element is sandwiched And a first disk having a first opening with an outer peripheral side seated on the seat portion, and a second disk having a second opening sandwiched on an inner peripheral side and communicating with the first opening, The opening has an opening area that restricts a flow of fluid flowing through the passage of the main valve, the second opening has an opening area larger than the first opening, and the outer peripheral side of the main valve body is A pressure chamber is formed to open the main valve body by being separated from the second disk. The main valve body is sandwiched on the inner peripheral side, and the packing fixed to the outer peripheral side on the back surface can slide on the pilot member. The first pilot chamber is closed by contacting the pilot chamber And body, is interposed between the first valve body and said second disk, and close the second opening, than the first valve body and a second valve body diameter.
As a second aspect, in the first aspect, the first disk is formed on one side and the other side in the disk radial direction via the first opening, and each of the first disks communicates with the first opening. A third disk having a third long hole communicating with the first long hole is provided on one side of the first disk, the first disk having a first long hole and a second long hole; On the other side, a fourth disk having a fourth long hole communicating with the second long hole is provided in an overlapping manner.
As a third aspect, in the second aspect, the first opening, the first long hole, the second long hole, the third long hole, and the fourth long hole are a passage of the valve seat member. And the pressure chamber are formed, and fluid flows from the outer side to the inner side in the disk radial direction in the communication path.
As a fourth aspect, in the second aspect, the first opening, the first long hole, the second long hole, the third long hole, and the fourth long hole are a passage of the valve seat member. And the pressure chamber are formed, and fluid flows from the inner side to the outer side in the radial direction of the disk.
As a fifth aspect, in any one of the first to fourth aspects, an outer diameter of a disk provided on the opposite side of the second disk from the second valve body is the second disk. It is the same diameter as the outer diameter.

Although only a few embodiments of the present invention have been described above, various modifications or improvements can be made to the illustrated embodiments without substantially departing from the novel teachings and advantages of the present invention. Will be easily understood by those skilled in the art. Therefore, it is intended that the embodiment added with such changes or improvements is also included in the technical scope of the present invention. You may combine the said embodiment arbitrarily.

This application claims priority based on Japanese Patent Application No. 2016-033223 filed on Feb. 24, 2016. The entire disclosure including the specification, claims, drawings, and abstract of Japanese Patent Application No. 2016-033223 filed on Feb. 24, 2016 is incorporated herein by reference in its entirety.

1 shock absorber, 2 cylinder, 5 piston, 6 piston rod, 31 damping force generation mechanism, 32 main valve, 35 valve member (valve seat member), 41 passage 41 (upstream passage of main valve), 44 passage, 50 pilot Body (pilot member), 52 Back pressure chamber (pilot chamber), 53 Pilot valve member (control valve), 60 passage (pilot passage), 81 First valve body (main valve body), 82 Second valve body (main valve) Body), 83, first disk (sub valve body), 84, second disk (sub valve body), 85, first opening, 89, second opening, 90 packing

Claims

A damping force adjustable shock absorber, the damping force adjustable shock absorber,
A cylinder filled with a working fluid;
A piston slidably fitted in the cylinder;
A piston rod connected to the piston and extending to the outside of the cylinder;
A main valve that generates a damping force by controlling a flow of a working fluid generated by sliding of the piston in the cylinder;
A pilot chamber that applies pressure in the valve closing direction to the main valve;
A pilot member forming the pilot chamber;
A pilot passage communicating the pilot chamber and the upstream passage of the main valve;
A control valve provided in the pilot passage,
The main valve is
A valve seat member having a passage through which the fluid in the cylinder flows, and a seat portion formed outside a downstream opening of the passage;
A sub-valve element that opens and closes the downstream side opening of the passage by being seated on the seat portion; and
A main valve body provided on the opposite side to the valve seat member among the sub valve bodies, and
The sub-valve is
A first disk having a first opening having an inner peripheral side of the first disk sandwiched between the valve seat member and the pilot member, and an outer peripheral side of the first disk seated on the seat portion When,
A second disc, the second disc having an inner peripheral side sandwiched between the valve seat member and the pilot member and having a second opening communicating with the first opening,
The first opening has an opening area for restricting a flow of fluid flowing through the passage of the main valve,
The second opening has an opening area larger than that of the first opening, and the second opening causes the outer peripheral side of the main valve body to be separated from the second disk to open the main valve body. A pressure chamber is formed,
The main valve body is
A first valve body, an inner peripheral side of the first valve body being sandwiched between the valve seat member and the pilot member, and a gasket fixed to the outer peripheral side of the back surface of the first valve body is used as the pilot member. A first valve body that slidably contacts and closes the pilot chamber;
A second valve body interposed between the first valve body and the second disk, closing the second opening, and having a smaller diameter than the first valve body;
A damping force adjustable shock absorber.
The damping force adjustable shock absorber according to claim 1,
The first disk is formed on one side and the other side of the disk radial direction through the first opening, each having a first long hole and a second long hole communicating with the first opening,
A third disk having a third long hole communicating with the first long hole is provided on one side of the first disk,
A damping force adjusting type shock absorber, wherein a fourth disk having a fourth long hole communicating with the second long hole is provided on the other side of the first disk.
The damping force adjustment type shock absorber according to claim 2,
The first opening, the first elongated hole, the second elongated hole, the third elongated hole, and the fourth elongated hole form a communication path that connects the passage of the valve seat member and the pressure chamber. ,
A damping force adjusting type shock absorber, characterized in that a fluid flows from the outer side to the inner side in the disk radial direction in the communication path.
The damping force adjustment type shock absorber according to claim 2,
The first opening, the first elongated hole, the second elongated hole, the third elongated hole, and the fourth elongated hole form a communication path that connects the passage of the valve seat member and the pressure chamber. ,
A damping force adjusting type shock absorber, wherein a fluid flows in the communication path from the inner side to the outer side in the disk radial direction.
The damping force adjustment type shock absorber according to any one of claims 1 to 4,
The damping force adjusting type shock absorber according to claim 1, wherein an outer diameter of a disk provided on the opposite side of the second disk to the second valve body is the same as an outer diameter of the second disk.