JP6047035B2 - Hydraulic shock absorber for vehicles - Google Patents

Description

  The present invention relates to an improvement of a hydraulic shock absorber for a vehicle.

  Conventionally, in a vehicle hydraulic shock absorber set to a single cylinder type, for example, a cylinder, a free piston that is slidably inserted into the cylinder and divides the inside of the cylinder into a liquid chamber and an air chamber, A piston that is slidably inserted into the cylinder and divides the liquid chamber into a pressure side chamber facing the air chamber and an extension side chamber not facing the air chamber, and a piston rod having one end connected to the piston, There is one that suppresses vibration of the vehicle body (see, for example, Patent Document 1).

  Further, in this single cylinder type hydraulic shock absorber for a vehicle, in the expansion / contraction stroke in which the piston moves in the axial direction with respect to the cylinder, the change in the volume in the cylinder when the rod enters and exits the cylinder. Compensation is achieved by increasing or decreasing the volume of the air chamber.

  By the way, the single cylinder type hydraulic shock absorber for a vehicle compresses the expansion side chamber where the piston does not face the air chamber and expands the volume of the opposite pressure side chamber in the extending stroke, so that the liquid is compressed on the compression side. It flows from the expansion side chamber to the expansion side pressure side chamber, resists the flow of this liquid and promotes the pressure increase in the compression side expansion side chamber, causes a difference in pressure between the expansion side chamber and the compression side chamber, and the differential pressure is applied to the piston. It exerts a damping force that prevents extension by acting.

  On the other hand, in the stroke to be compressed, the single cylinder type hydraulic shock absorber for the vehicle compresses the pressure side chamber facing the air chamber and expands the volume of the opposite extension side chamber. Flows from the compression-side compression side chamber to the expansion-side extension side chamber, resists the flow of this liquid, causes a difference in pressure between the compression-side chamber and the extension-side chamber, and prevents compression by acting on the piston with the differential pressure. Demonstrates damping force.

  Thus, the single cylinder type hydraulic shock absorber for the vehicle compresses the extension side chamber that does not face the air chamber during the extension stroke, so that the pressure of the extension side chamber is within the range that the durability of the seal around the rod allows. Can be increased any number of times.

  On the other hand, during the compression stroke, the pressure chamber facing the air chamber is compressed and the air chamber itself is also compressed, but the volume elastic modulus of the gas is smaller than the volume elastic modulus of the liquid and the pressure of the air chamber Since the increase is small, the pressure increase in the compression chamber is small, and the expansion chamber that does not face the air chamber is depressurized, so that the pressure field in the cylinder (the average pressure of the expansion chamber pressure and the compression chamber pressure) decreases. .

  As a result, the rigidity of the liquid column is lowered due to the influence of gas dissolved in the liquid.In particular, at the initial stage of switching from the expansion stroke to the compression stroke, the rising of the damping force during the compression stroke tends to be insufficient in time. In the case of a cylinder-type hydraulic shock absorber for a vehicle, further improvement in damping force generation response during the compression stroke is required.

  Therefore, the single cylinder type vehicle hydraulic shock absorber is designed to increase the damping force during the compression stroke by sealing the pressurized gas into the air chamber and maintaining the liquid in the cylinder in a constantly pressurized state. Has been given.

  However, when the pressure in the air chamber is increased, the pressure in the fluid chamber in the cylinder of the vehicle hydraulic shock absorber increases, and this pressure also acts on the oil seal that seals around the rod. The tightening force increases, the sliding resistance of the rod becomes excessive, and the smooth expansion and contraction of the single cylinder type hydraulic shock absorber is impeded. Especially when used in vehicle applications, the occupant feels jerky. This can hinder ride comfort in the vehicle.

  Therefore, a compensation chamber having a gas chamber and a liquid chamber communicated with the pressure side chamber and a valve element that provides resistance to the flow of liquid from the pressure side chamber to the liquid chamber are provided in the cylinder, and the pressure side during the compression stroke is provided. There is also an improved shock absorber that improves the damping force generation response during the compression stroke so as to compensate for the pressure increase in the chamber (see, for example, Patent Document 2).

JP 08-159199 A (FIG. 1) Japanese Patent Laying-Open No. 2010-60083 (FIG. 1)

  However, such an improved shock absorber is superior in that it can improve the damping force generation response during the compression stroke, but it is possible to adjust the degree of pressure rise in the compression side chamber during the compression stroke. Therefore, the damping force and the damping force generation response cannot be adjusted.

  In addition, a damping valve mounted on this type of vehicle hydraulic shock absorber includes a throttle such as an orifice or a choke that exerts a damping force mainly when the piston speed is low, and a valve that opens when the piston speed becomes high. However, when adjusting the damping force, only the opening area of the throttle or only the valve opening pressure of the latter valve is adjusted. In addition, the degree of pressure increase in the compression side chamber during the compression stroke could not be adjusted intuitively and easily.

  Therefore, the present invention was devised to improve the above-described problems, and the object of the present invention is to intuitively and easily adjust the degree of pressure increase in the compression side chamber during the compression stroke, It is an object of the present invention to provide a vehicular hydraulic shock absorber capable of adjusting damping force generation responsiveness.

To solve the problems described above, the first means for solving problems of the present invention, the cylinder and a piston that is inserted slidably into the cylinder, the movably inserted in the piston within the cylinder A piston rod to be connected; an expansion side chamber and a pressure side chamber defined by the piston in the cylinder; a valve case provided on a side of the cylinder and having a hollow portion therein; and an axial direction in the cylinder. a liquid chamber tube to form a liquid chamber which communicates with the compression side chamber through the hollow portion therein while being connected along a biasing means for biasing the liquid chamber, is accommodated within the hollow portion A partition member that divides the pressure side chamber and the liquid chamber, a throttle valve that is accommodated in the hollow portion and communicates with the pressure side chamber and the liquid chamber and provides resistance to the flow of liquid passing therethrough, and the inside of the hollow portion Housed in A valve element that communicates the pressure side chamber and the liquid chamber in parallel with the throttle valve, and that provides resistance to the flow of liquid passing therethrough, and is housed in the hollow portion and in parallel with the throttle valve and the valve element. A check valve that allows only the flow of liquid from the liquid chamber toward the pressure side chamber, and an adjustment mechanism that simultaneously changes the opening area of the throttle valve and the resistance of the valve element. A valve body that is disposed on the liquid chamber side of the member and that opens and closes an outlet of a port that communicates the pressure chamber and the liquid chamber formed in the partition member; And a spring element that is interposed between the valve body and the spring receiver and biases the valve body toward the partition member, and the throttle valve has a bottomed cylindrical shape. The inside opens to the side of the hollow shaft that communicates with the pressure side chamber. The adjustment mechanism is in contact with the side of the spring support provided on the hollow shaft with the spring support mounted on the outer periphery thereof, so that the spring support receives the spring support. A restricting portion for restricting movement of the hollow shaft toward the partitioning member, a driving means for moving the hollow shaft in the axial direction with respect to the partitioning member, and driving the hollow shaft that is immovable with respect to the driving of the hollow shaft. On the other hand, a shutter for increasing or decreasing the lap area with the elongated hole is provided, and the opening area of the throttle valve and the initial load of the spring element are simultaneously changed by driving the driving means .
In order to solve the above-described problems, the second problem-solving means of the present invention includes a cylinder, a piston that is slidably inserted into the cylinder, and a slidably inserted into the cylinder. A piston rod to be connected; an expansion side chamber and a pressure side chamber defined by the piston in the cylinder; a valve case provided on a side of the cylinder and having a hollow portion therein; and an axial direction in the cylinder. A liquid chamber cylinder that forms a liquid chamber that is connected along the inside and communicates with the pressure side chamber via the hollow portion, an urging means that urges the liquid chamber, and is accommodated in the hollow portion. A partition member that divides the pressure side chamber and the liquid chamber, a throttle valve that is accommodated in the hollow portion and communicates with the pressure side chamber and the liquid chamber and provides resistance to the flow of liquid passing therethrough, and the inside of the hollow portion Housed in A valve element that communicates the pressure side chamber and the liquid chamber in parallel with the throttle valve, and that provides resistance to the flow of liquid passing therethrough, and is housed in the hollow portion and in parallel with the throttle valve and the valve element. A check valve that allows only the flow of liquid from the liquid chamber to the pressure side chamber, an adjustment mechanism that simultaneously changes the opening area of the throttle valve and the resistance of the valve element, and one end of the liquid chamber cylinder. A liquid chamber cylinder flange having a plurality of bolt insertion holes, a cylinder flange provided at one end of the cylinder and having the same number of bolt insertion holes as the bolt insertion holes provided in the liquid chamber cylinder flange, and provided in the valve case A closing member that closes the end of the cylinder and the end of the liquid chamber cylinder and has the same number of bolt insertion holes as the bolt insertion holes provided in the liquid chamber cylinder flange, The cylinder, the liquid chamber tube, and the closing member are fastened by bolts inserted into the bolt insertion holes in a state where the closing member is interposed between the Linda and the liquid chamber tube. Features.

  According to the single cylinder type hydraulic shock absorber of the present invention, it is possible to rapidly increase the pressure in the compression side chamber and exhibit the compression side damping force while suppressing the decrease in the pressure field in the expansion side chamber and the compression side chamber. Therefore, it is possible to eliminate the tendency that the rising of the damping force is insufficient in the initial stage of switching from the expansion stroke to the compression stroke or when the piston speed is low during the compression stroke, and the damping force generation response is improved.

  In addition, since there is no need to increase the pressure in the air chamber, the pressure in the container of the hydraulic shock absorber for the vehicle does not become excessively high, and there is no fear that the tightening force of the seal member that seals around the rod will increase. It does not disturb the ride comfort of the vehicle by making the vehicle occupant perceive a jerky feeling.

  According to the vehicle hydraulic shock absorber of the present invention, a necessary and sufficient damping force can be exhibited with good responsiveness even in the initial stage of the compression stroke without impairing the ride comfort in the vehicle.

  Furthermore, since both the throttle valve and the valve element can be adjusted simultaneously with respect to the pressure rise characteristics of the pressure side chamber, it is possible to adjust only the throttle valve or the buffer that can adjust only the valve element, or both. Adjust pressure rise characteristics of the pressure side chamber more easily and more intuitively (compression characteristics of the pressure side chamber with respect to piston speed) compared to shock absorbers that must be adjusted independently, even if possible Therefore, the adjustment of the damping force responsiveness on the compression side can be easily performed as well.

It is a longitudinal cross-sectional view of the hydraulic shock absorber for vehicles in one embodiment. It is a partially expanded longitudinal cross-sectional view of the hydraulic shock absorber for vehicles in one embodiment. It is a figure explaining the compression side attenuation | damping characteristic of the hydraulic buffer for vehicles in one embodiment. It is a figure explaining the change of the pressure rise characteristic of the compression side chamber by the adjustment mechanism of the hydraulic buffer for vehicles in one embodiment. It is a figure explaining the change of the compression side damping characteristic by the adjustment mechanism of the hydraulic shock absorber for vehicles in one embodiment. It is a longitudinal cross-sectional view in the hydraulic shock absorber for vehicles of one Embodiment at the time of giving initial stage bending to the valve body of a valve element. It is a figure explaining operation | movement of the hydraulic shock absorber for vehicles of one Embodiment at the time of giving initial deflection to the valve body of a valve element. It is a figure explaining the pressure side attenuation | damping characteristic in the hydraulic buffer for vehicles of one Embodiment at the time of giving initial deflection to the valve body of a valve element.

  The present invention will be described below based on the embodiments shown in the drawings. As shown in FIG. 1 and FIG. 2, a vehicle hydraulic shock absorber D according to an embodiment includes a cylinder 1, a piston 2 that is slidably inserted into the cylinder 1, and a movable body within the cylinder 1. A piston rod 3 inserted into the piston 2 and connected to the piston 2, an extension side chamber R1 and a pressure side chamber R2 defined by the piston 2 in the cylinder 1, and a hollow portion A provided in the side of the cylinder 1 inside. And a liquid chamber cylinder 5 that forms a liquid chamber L that is connected to the cylinder 1 along the axial direction and communicates with the pressure side chamber R2 through the hollow portion A. The urging means 6 for energizing, the partition member 7 accommodated in the hollow portion A for partitioning the pressure side chamber R2 and the liquid chamber L, and the pressure side chamber R2 and the liquid chamber L communicated in the hollow portion A. And a throttle valve 8 that provides resistance to the flow of liquid that passes through and the hollow portion A And a valve element 9 that communicates the pressure side chamber R2 and the liquid chamber L in parallel with the throttle valve 8 and provides resistance to the flow of the liquid passing therethrough, and is accommodated in the hollow portion A and accommodates the throttle valve 8 and the valve. A check valve 10 that allows only the flow of liquid from the liquid chamber L to the pressure side chamber R2 in parallel with the element 9, and an adjustment mechanism 11 that simultaneously changes the opening area of the throttle valve 8 and the resistance in the valve element 9 It is provided, and is interposed between a vehicle body and an axle (not shown) to suppress vibration of the vehicle body.

  Hereinafter, each member will be described in detail. The cylinder 1 has a cylindrical shape, and a lower end thereof is closed by a closing member 12 provided in the valve case 4, and a rod guide 13 that slidably supports the piston rod 3 is fitted to the upper end in FIG. ing. A seal member 14 is laminated above the rod guide 13. The seal member 14 is fastened and fixed to the cylinder 1 together with the rod guide 13 by a cap 15 that is screwed to the outer periphery of the upper end of the cylinder 1 in FIG. Yes.

  Moreover, the cylinder flange 1a is provided in the end which is the lower end in FIG. 1 of the cylinder 1, and 16 bolt insertion holes 1b are provided in this cylinder flange 1a at equal intervals in the circumferential direction.

  The seal member 14 includes a lip portion 14a that is in sliding contact with the outer periphery of the piston rod 3 and an outer peripheral seal portion 14b that is in close contact with the rod guide 13 so that the space between the piston rod 3 and the rod guide 13 is tightly sealed. Has been. Further, a seal ring 13 a that is in close contact with the inner periphery of the cylinder 1 is provided on the outer periphery of the rod guide 13, so that the space between the cylinder 1 and the rod guide 13 is tightly sealed.

  A piston 2 fixed to the tip of the piston rod 3 is slidably inserted into the cylinder 1, and the piston 2 causes the cylinder 1 to have an upper extension side chamber R1 in FIG. 1 and a lower portion in FIG. It is partitioned into a compression side chamber R2. The extension side chamber R1 and the pressure side chamber R2 are filled with a liquid such as hydraulic oil, and the extension side chamber R1 and the pressure side chamber R2 are communicated with each other by a damping passage 16 provided in the piston 2.

The damping passage 16 is provided with a damping valve 17 so as to provide resistance to the flow of liquid passing therethrough, and when the vehicle hydraulic shock absorber D is expanded or contracted, the extension side chamber R1 to the pressure side chamber R2, or giving resistance to the flow of liquid moving from the pressure side chamber R 2 to the expansion side chamber R 1 have become cause a difference in pressure of these expansion side chamber R1 and the compression side chamber R2, fluid pressure shock absorber D for a vehicle A damping force commensurate with the differential pressure between the two is generated.

  It should be noted that the damping valve 17 only needs to provide resistance to the flow of the liquid when the liquid passes and cause a predetermined pressure loss. Specifically, for example, a damping valve such as an orifice or a leaf valve is employed. can do. Further, both a damping passage allowing only the flow from the expansion side chamber R1 to the compression side chamber R2 and a damping passage allowing only the flow from the compression side chamber R2 to the expansion side chamber R1 are provided, and a damping valve is provided for each. The structure provided may be employ | adopted and the attenuation | damping channel | path may be provided in the piston rod 3 besides the piston 2, or may be provided out of the cylinder 1.

  Further, in this case, the vehicle hydraulic shock absorber D is a single rod type shock absorber, and as will be described in detail later, a volume of liquid that enters the cylinder 1 of the piston rod 3 during the compression stroke is stored in the cylinder 1. When the pressure is increased and discharged from the pressure side chamber R2 to the liquid chamber L, a damping force can be generated by giving resistance to the flow of the liquid by the throttle valve 8 and the valve element 9. Therefore, in the case of providing a damping passage that allows only the flow from the expansion side chamber R1 to the compression side chamber R2, only a check valve that allows only the flow from the compression side chamber R2 to the expansion side chamber R1 is provided to almost resist flow. There may be no passage.

  The liquid chamber cylinder 5 is closed at the lower end in FIG. 1 and is provided with a bracket 5a at the lower end that enables attachment to a vehicle. Moreover, the liquid chamber cylinder flange 5b is provided in the end which is the upper end in FIG. 1 of the liquid chamber cylinder 5, and this liquid chamber cylinder flange 5b has the same number as the bolt insertion hole 1b provided in the cylinder flange 1a. Sixteen bolt insertion holes 5c are provided at equal intervals in the circumferential direction. The bolt insertion hole 5c is formed as a screw hole with a thread formed on the inner periphery.

  A free piston 18 is slidably inserted into the liquid chamber cylinder 5, and a liquid chamber L is defined in the liquid chamber cylinder 5 and above the free piston 18 in FIG. An air chamber G is defined below the free piston 18 in FIG. The air chamber G forms an air spring as an urging means 6 that urges the liquid chamber L with internal pressure, and gas is supplied to the air chamber G through a valve 19 provided below the liquid chamber cylinder 5. It can be filled. In addition to the air spring described above, the biasing means 6 may be a metal spring or the like that presses the free piston 18, and does not define the air chamber G with the free piston 18, An air chamber may be formed by a diaphragm or a bladder, and this may be used as an urging means.

  Subsequently, as shown in FIGS. 1 and 2, the valve case 4 includes a bottomed cylindrical case body 20 having a hollow portion A, a lower end of the cylinder 1 in FIG. 1, and a liquid chamber cylinder 5 in FIG. 1. A closing member 12 interposed between the upper ends, a cylindrical cylinder side socket 21 rising from the upper end in FIG. 1 of the closing member 12, and a cylindrical liquid chamber cylinder side socket rising from the lower end in FIG. 22, a connecting portion 23 that connects the closing member 12 and the case main body 20, 16 bolt insertion holes 24 provided at equal intervals in the circumferential direction on the outer peripheral side of the closing member 12, A communication hole 25 that opens from the periphery and communicates with the cylinder side socket 21 via the connecting portion 23, and a communication hole that opens from the inner periphery of the case body 20 and communicates with the liquid chamber cylinder side socket 22 via the connection portion 23. 26.

  The case main body 20 is provided with a stepped portion 20a on the inner periphery. A communication hole 25 is opened from above the stepped portion 20a, and a communication hole 26 is opened from below the stepped portion 20a. When the cylinder side socket 21 is inserted into the cylinder 1 and the liquid chamber tube side socket 22 is inserted into the liquid chamber tube 5, the hollow portion A in the case body 20 is connected to the pressure side chamber R <b> 2 through the communication hole 25. The fluid chamber L communicates with the liquid chamber L through the communication hole 26.

Further, as shown in FIG. 2, the upper end opening in FIG. 1 of the case body 20, that is, the opening 20 b leading to the hollow portion A, is freely rotatable to the inner periphery of the annular adjuster holding member 29 And the adjuster 30 held in the middle. The adjuster holding member 29 has an outer periphery, and the upper part in FIG. 2 is screwed into the opening 20b of the case body 20, and a seal ring 31 is attached to the lower part of the outer periphery in FIG. The holding member 29 and the case body 20 are tightly sealed, and further, the adjuster holding member 29 and the adjuster 30 are tightly sealed by a seal ring 32 attached to the outer periphery of the adjuster 30, thereby hollowing out. Leakage of liquid from the part A is prevented. 2, which is an end portion of the adjuster 30 on the hollow portion A side, is provided with a flange 30a protruding toward the outer periphery , and the flange 30a is on the hollow portion A side of the adjuster holding member 29. 2, the adjuster 30 is prevented from coming off from the adjuster holding member 29 by being fitted into an annular recess 29 a provided at the inner periphery of the middle lower end. The adjuster 30 includes a screw hole 30b that opens from the end on the hollow portion A side and a tool insertion hole 30c that opens from the end on the anti-hollow portion A side, and inserts a tool (not shown) into the tool insertion hole 30c. By rotating the adjuster 30, the adjuster 30 can be rotated in the circumferential direction by an external operation. The adjuster 30 may be rotated by a drive source such as a motor.

  A partition member 7 is attached to a step portion 20a provided in the inner periphery of the case body 20 in the hollow portion A provided in the case body 20, and the partition member 7 is disposed in the hollow portion A. 2 is divided into an upper room and a lower room. The upper room communicates with the pressure side chamber R2 via the communication hole 25 and functions as a part of the pressure side chamber R2. The chamber communicates with the liquid chamber L through the communication hole 26 and functions as a part of the liquid chamber L. Therefore, the partition member 7 functions as a partition that partitions the pressure side chamber R2 and the liquid chamber L.

In this case, the closing member 12 has a disk shape, and 16 bolt insertion holes 24 are provided on the outer peripheral side thereof at equal intervals in the circumferential direction. The bolt insertion holes 24 are provided in the same number as 16 bolt insertion holes 1b and 5c provided in the cylinder flange 1a and the liquid chamber cylinder flange 5b. These bolt insertion holes 1b, 5c , 24 are provided on the circumference of the same diameter, and when the closing member 12 is sandwiched between the cylinder 1 and the liquid chamber cylinder 5 and aligned in the circumferential direction, three bolt insertion holes are provided. 1b, 5 c, 24 a bolt insertion hole B is formed by, by screwing the bolt insertion hole 5c is a tip and screw hole by inserting the bolts 27 into the bolt insertion hole B, a cylinder 1, The liquid chamber cylinder 5 and the valve case 4 are integrated. Since 16 bolt insertion holes 1b, 5c , 24 are provided in this example, the valve case 4 is located at 16 positions in the circumferential direction with respect to the cylinder 1 and the liquid chamber cylinder 5 by 22.5 degrees. Any one of the positions can be selected and fixed. That is, by attaching the valve case 4 in this way, the positions of the valve case 4 with respect to the cylinder 1 and the liquid chamber cylinder 5 can be selected. Therefore, when the vehicle shock absorber D is incorporated in the vehicle, the valve case 4 It can be positioned so that it does not get in the way. The bolt insertion holes 1b, 5c , 24 may be provided in a balanced manner, and at least three may be provided. The bolt insertion hole 5c is not a screw hole but a simple hole, and the cylinder 1, the liquid chamber cylinder 5 and the valve case 4 may be integrated using a nut screwed to the bolt 27, or the bolt insertion hole 5c may be integrated. The bolt 27 may be inserted into the bolt insertion hole B from the lower side of the liquid chamber cylinder flange 5b in FIG.

  In this way, the closing member 12 is clamped by the bolt 27 so as to sandwich the closing member 12 between the cylinder 1 and the liquid chamber cylinder 5, and the cylinder side socket 21 provided in the closing member 12 is fitted into the cylinder 1. At the same time, since the liquid chamber cylinder side socket 22 is fitted into the liquid chamber cylinder 5, the cylinder 1, the valve case 4 and the liquid chamber cylinder 5 are prevented from rattling, and the cylinder 1 and the liquid chamber cylinder 5 are prevented from being loose. It can withstand the moment input. A seal ring 21 a is attached to the outer periphery of the cylinder-side socket 21, so that the space between the cylinder 1 and the cylinder 1 is tightly sealed, and a seal ring 22 a is also attached to the outer periphery of the liquid chamber-cylinder side socket 22. 5 is tightly sealed.

  Subsequently, in the hollow portion A of the valve case 4 configured as described above, in addition to the partition member 7, the pressure side chamber R2 and the liquid chamber L communicate with each other and provide a resistance to the flow of liquid passing therethrough. A valve element 9 which communicates the pressure side chamber R2 and the liquid chamber L in parallel with the throttle valve 8 and provides resistance to the flow of the liquid passing therethrough; a liquid chamber in parallel with the throttle valve 8 and the valve element 9; A check valve 10 that allows only the flow of liquid from L to the pressure side chamber R2 is provided.

  Therefore, when the piston 2 moves upward in FIG. 1 with respect to the cylinder 1, that is, when the vehicle hydraulic shock absorber D is extended, the piston 2 compresses the expansion side chamber R1 and expands the pressure side chamber R2. Therefore, the liquid in the extension side chamber R1 moves to the compression side chamber R2 via the attenuation passage 16. A resistance is given to the flow of liquid passing through the damping passage 16 by the damping valve 17, and the vehicle hydraulic shock absorber D generates the damping force on the extension side. Further, since the piston rod 3 is retracted from the cylinder 1, the liquid deficient in the cylinder 1 is supplied from the liquid chamber L into the cylinder 1 through the check valve 10, and is in proportion to the volume of the liquid flowing out from the liquid chamber L. The free piston 18 moves downward in FIG. 1 to increase the volume of the air chamber G to compensate for the volume change in the cylinder 1.

  On the contrary, when the piston 2 moves downward in FIG. 1 with respect to the cylinder 1, that is, when the vehicle hydraulic shock absorber D is compressed, the piston 2 compresses the compression side chamber R2 and expands the expansion side chamber R1. Therefore, the liquid in the compression side chamber R2 moves to the expansion side chamber R1 via the attenuation passage 16, and the volume of liquid that the piston rod 3 enters the cylinder 1 and the piston rod 3 enters the cylinder 1 is retained. Since there is surplus in the cylinder 1, surplus liquid is discharged into the liquid chamber L through the throttle valve 8 and the valve element 9, and the free piston 18 corresponds to the volume of the liquid flowing into the liquid chamber L as shown in FIG. Moving in the middle and upward, the volume of the air chamber G decreases to compensate for the volume change in the cylinder 1. Since the excess liquid in the cylinder 1 is discharged into the liquid chamber L through the throttle valve 8 and the valve element 9, the pressure field in the cylinder 1 (the average pressure of the expansion side chamber pressure and the pressure side chamber pressure) is suppressed. At the same time, a resistance is given to the flow of the liquid passing through the damping passage 16 by the damping valve 17 to cause a difference between the pressures of the compression side chamber R2 and the expansion side chamber R1, and the vehicle hydraulic pressure buffer D has a compression side damping force. Is generated. In addition, when a passage provided with a check valve that allows the flow from the pressure side chamber R2 to the extension side chamber R1 is provided, the flow of liquid from the pressure side chamber R2 to the extension side chamber R1 is hardly given resistance. However, since the pressure in the pressure side chamber R2 can be increased by the throttle valve 8 and the valve element 9, the vehicular hydraulic pressure damper D can sufficiently generate the pressure side damping force.

  As shown in FIG. 2, the partition member 7 has an annular shape, and includes a port 33 penetrating in the axial direction which is the vertical direction in the figure, and a port 33 provided on the lower end side in FIG. 2 which is the liquid chamber L side. An annular valve seat 34 formed on the outer periphery of the outer periphery, a recess 7a provided on the outer periphery, and a groove 7b provided from the outer periphery of the upper end in FIG. And an inner peripheral recess 7c that is provided with an enlarged inner peripheral diameter at the upper end in FIG. 2 on the adjuster holding member 29 side and communicated with the groove 7b. Note that the number of ports 33 can be set as long as the opening area can be secured, and the grooves 7b may be provided corresponding to the number of ports 33 set. Therefore, the upper end in FIG. 2 of the port 33 is communicated with the pressure side chamber R2 in the cylinder 1 through the groove 7b and the communication hole 25, and the lower end in FIG. 2 of the port 33 is connected to the liquid chamber L through the communication hole 26. It is communicated. Further, a chamfered portion 7d is provided on the outer periphery of the upper end of the partition member 7 in FIG. 2, and this is a partition member that prevents the liquid flow from the port 33 to the communication hole 25 and from the communication hole 25 to the port 33. 7 and the valve case 4 are provided in order to secure a flow path area so as not to be blocked by an annular gap between the case body 20 and the chamfered portion 7d, thereby securing a flow path area. Therefore, the length of the case body 20 of the valve case 4 in the vertical direction in FIG. 2 can be shortened.

  The partition member 7 is in contact with the lower end in FIG. 2 of the annular adjuster holding member 29 that is screwed to the inner periphery of the opening 20b provided at the upper end in FIG. Further, the outer periphery of the partition member 7 is fitted into a step portion 20a provided on the inner periphery of the case body 20 so that the downward movement in FIG. It is in contact with the upper end of. Therefore, the partition member 7 is sandwiched between the adjuster holding member 29 and the valve cap 40 and accommodated and fixed in the hollow portion A of the valve case 4.

  Specifically, the valve cap 40 is in contact with the outer periphery of the partition member 7 and also has a cylindrical contact portion 40a that contacts the side surface of the partition member in the step portion 20a of the case body 20, and an annular shape that is continuous with the contact portion 40a. In FIG. 2, the outer peripheral diameter is smaller than the contact portion 40 a and is fitted to the inner periphery of the step portion 20 a of the case body 20, and the inner periphery of the fitting portion 40 b is on the side opposite to the partitioning member. A cylindrical portion 40c provided downward, two notches 40d provided from the opposite end of the cylindrical portion 40c to the partition member side, which is the lower end of the cylindrical portion 40c in FIG. 2, and a partition member side end of the abutting portion 40a. A plurality of projections 40e provided at appropriate intervals in the direction and projecting toward the partition member side, and a plurality of holes 40f penetrating through the fitting portion 40b and communicating with the inside and outside of the valve cap 40. Protrusions 40e are formed on the outer periphery of the partition member 7 By fitting in the recessed portion 7a, the relative rotation in the circumferential direction of the valve cap 40 and the partition member 7 is restricted, and the partition member 7 is radially connected to the valve cap 40 by the fitting of the projection 40e and the recessed portion 7a. Also positioned. When the valve cap 40 is inserted into the inner periphery of the case body 20 in the valve case 4, the outer periphery of the upper end of the contact portion 40 a contacts the upper end of the step portion 20 a, so Movement to is regulated. Note that the number of holes 40f is arbitrary as long as the opening area can be secured.

  In addition, a cylindrical hollow shaft 35 with a bottom is inserted in the inner periphery of the partition member 7 so as to be slidably contacted with the inner periphery and slidable in the axial direction and freely rotatable in the circumferential direction. The hollow shaft 35 includes a screw portion 35a provided on the outer periphery on the opening side that is the tip, an annular groove 35b provided on the outer periphery in the lower part in FIG. 2 from the screw portion 35a, and a through hole 35c that communicates the inside with the annular groove 35b. A throttle valve 8 which is an orifice having a long hole provided below the annular groove 35b in FIG. 2, and two regulating portions 35d which are provided on the outer periphery of the lower end in FIG. It is configured with.

  The hollow shaft 35 is inserted into the adjuster 30 through the inner periphery of the partition member 7 on the opening side, and the screw portion 35 a of the hollow shaft 35 is screwed into the screw hole 30 b of the adjuster 30. The two restricting portions 35 d of the hollow shaft 35 are respectively inserted into the notches 40 d of the valve cap 40, and the rotation of the hollow shaft 35 in the circumferential direction is restricted by the valve cap 40. Further, the adjuster 30 is positioned in the axial direction with the flange 30a sandwiched between the partition member 7 and the adjuster holding member 29, so that the valve case 4 is prevented from coming off while being allowed to rotate in the circumferential direction. And attached to the valve case 4.

  Therefore, when the adjuster 30 is rotated, the rotation of the hollow shaft 35 in the circumferential direction is restricted by the valve cap 40, and therefore, in the manner of a feed screw formed by the screw portion 35a and the screw hole 30b, It is possible to move in the axial direction and to move away from the partition member 7.

The axial width of the annular groove 35b of the hollow shaft 35 is set so that the hollow shaft 35 can face the groove 7b of the partition member 7 even if the hollow shaft 35 is moved up and down by the adjuster 30. The hollow shaft 35 communicates with the pressure side chamber R2 in the cylinder 1 through the through hole 35c, the annular groove 35b, the inner peripheral recess 7c, the groove 7b, and the communication hole 25, and through the throttle valve 8 to the liquid chamber L. Is communicated to. That is, the pressure side chamber R2 and the liquid chamber L are communicated by the throttle valve 8. The throttle valve 8 provides resistance by restricting the flow of liquid passing through the throttle valve 8.

  A cylindrical shutter 36 seated on the inner periphery inside the hollow portion of the partition member 7 is slidably mounted on the outer periphery of the hollow shaft 35, and the shutter 36 is a cylinder that is in sliding contact with the outer periphery of the hollow shaft 35. A portion 36a and a flange-like valve support portion 36b provided on the outer periphery of the cylindrical portion 36a are provided.

  Further, on the outer periphery of the cylindrical portion 36 a of the shutter 36, an annular valve body 37 that is attached to and detached from an annular valve seat 34 formed at the lower end on the liquid chamber L side of the partition member 7, and the partition member of the valve body 37 An annular check valve 10 stacked on the side and a valve pressing member 38 stacked on the side of the valve body 37 opposite to the partition member are slidably mounted.

  A cylindrical spring support 39 facing the shutter 36 is slidably mounted on the outer periphery of the hollow shaft 35 and on the side opposite to the partition member from the shutter 36. The spring receiver 39 includes a cylindrical portion 39a slidably mounted on the outer periphery of the hollow shaft 35, and a flange-shaped spring receiver 39b provided on the outer periphery of the cylindrical portion 39a. Between the holding member 38, a coil spring 41 as a spring element is interposed in a compressed state. Therefore, the spring receiver 39 and the valve restraining member 38 are urged so as to be always separated from each other by the coil spring 41. When the spring receiver 39 abuts on the regulating portion 35d of the hollow shaft 35, the spring receiving 39 is hollowed by the regulating portion 35d. Since further movement of the shaft 35 toward the lower side in FIG. 2 is restricted, the coil spring 41 urges the shutter 36 toward the partition member 7 via the valve restraining member 38.

Between the shutter 36 and the partition member 7, as shown in FIG. 2, a spring member 42 for biasing the check valve 10 to the valve body 37 side is interposed, the spring member 42, An annular member 42a sandwiched between the shutter 36 and the partition member 7, and an elastic support from the outer periphery of the annular member 42a to the partition member side of the check valve 10 and urging the check valve 10 toward the valve body 37 And a plurality of arms 42b.

  Further, as shown in FIG. 2, the valve body 37 is configured by an annular leaf valve, and includes a plurality of through holes 37 a on the same circumference, and the check valve 10 is formed by the check valve 10. In the state of being in contact with 37, the check valve 10 shuts off. The number of the through holes 37a is arbitrary as long as an opening area required for the function of the check valve 10 can be secured.

As described above, when the spring member 42, the shutter 36, the valve body 37, the valve holding member 38, the coil spring 41 and the spring receiver 39 are attached to the outer periphery of the hollow shaft 35 and assembled to the partition member 7 , the check valve 10 is The spring member 42 is biased toward the valve body 37 to block the through hole 37a, and the coil spring 41 biases the valve body 37 toward the partition member 7 via the valve restraining member 38.

  In this case, the valve element 9 is disposed on the liquid chamber L side of the partition member 7 and opens and closes the outlet of the port 33 that communicates the pressure side chamber R2 formed in the partition member 7 and the liquid chamber L. And an annular spring receiver 39 disposed on the side of the valve body 37 opposite to the partition member, and interposed between the valve body 37 and the spring receiver 39 to urge the valve body 37 toward the partition member 7 side. It comprises a coil spring 41 as a spring element. That is, the valve element 37 is bent by being biased toward the annular valve seat 34 by the biasing force of the coil spring 41 via the valve restraining member 38, and the pressure in the pressure side chamber R <b> 2 is higher than the pressure in the liquid chamber L. When the pressure difference between the pressure of the pressure side chamber R2 acting via the port 33 and the pressure of the liquid chamber L acting on the back side which is the side opposite to the partitioning member reaches the valve opening pressure, the outer periphery of the valve element 37 is In FIG. 2, the port 33 is opened by bending downward, and resistance is given to the flow of liquid passing through the pressure side chamber R <b> 2 in communication with the liquid chamber L. On the contrary, in the valve element 9, the valve element 37 remains seated on the annular valve seat 34 when the pressure in the pressure side chamber R 2 is higher than the pressure in the liquid chamber L and the differential pressure does not reach the valve opening pressure. Thus, the liquid chamber L is not communicated with the pressure side chamber R2.

  The check valve 10 is stacked on the valve body 37, receives the pressure of the liquid chamber L through the through hole 37 a of the valve body 37, and has a pressure side chamber on the back side which is the side opposite to the partition member through the port 33. The pressure of R2 is received. When the pressure in the liquid chamber L becomes higher than the pressure in the pressure side chamber R2 and the force that pushes up the check valve 10 in FIG. 2 overcomes the urging force of the spring member 42, the check valve 10 moves away from the valve body 37 and is liquid. The chamber L communicates with the pressure side chamber R2, but when the pressure in the pressure side chamber R2 is higher than the pressure in the liquid chamber L, it is pressed against the valve body 37, so that the through-hole 37a remains blocked and the pressure side chamber R2 There is no communication with the liquid chamber L.

Thus, the valve element 9 that allows only the flow of liquid from the pressure side chamber R2 to the liquid chamber L and the check valve 10 that allows only the flow of liquid from the liquid chamber L to the pressure side chamber R2 are connected to the port 33. They are provided in parallel. Note that the check valve 10 uses a through hole 37a provided in the valve element 37 of the valve element 9, and the check valve 10 and the valve element 9 are inseparable. Also good. However, as described above, by providing the valve body 37 in the valve element 9 with the through hole 37a and providing the annular check valve 10 for opening and closing the through hole 37a, there is an advantage that the check valve 10 can be configured compactly. Further, in the above description, the spring element in the valve element 9 and the spring member in the check valve 10 are each made of a metal spring, but it is only necessary to be able to exert a biasing force. May be.

  Further, the lower end in FIG. 2 of the cylindrical portion 36a of the shutter 36 is opposed to the lower end of the throttle valve 8 which is a long hole provided in the hollow shaft 35, and a part of the lower end side of the throttle valve 8 is closed and a spring bearing is received. 2 also opposes the upper end of the throttle valve 8 which is a long hole provided in the hollow shaft 35 and closes a part of the upper end of the throttle valve 8. Here, when the hollow shaft 35 is pulled upward in FIG. 2 by the turning operation of the adjuster 30 and brought close to the partition member 7, the regulating portion 35d of the hollow shaft 35 presses the spring receiver 39 upward. The spring receiver 39 moves upward in the figure. On the other hand, since the shutter 36 is in contact with the partition member 7 and the upward movement is restricted by the partition member 7, when the hollow shaft 35 approaches the partition member 7 by the operation of the adjuster 30, The distance between the lower end of the cylindrical portion 36 a of the shutter 36 and the upper end of the cylindrical portion 39 a of the spring receiver 39 becomes narrower as the spring receiver 39 approaches, and the throttle valve 8 is closed by the shutter 36 and the spring receiver 39. The area to be increased. That is, when the hollow shaft 35 moves toward the partition member 7, the opening area that is not blocked by the shutter 36 and the spring receiver 39 of the throttle valve 8 decreases, and the flow of liquid that the throttle valve 8 passes through. The resistance given to is increased.

  In the case of this embodiment, the axial positional relationship between the hollow shaft 35 and the spring receiver 39 does not change even when the hollow shaft 35 moves to the hollow shaft 35, that is, the lap area between the spring receiver 39 and the throttle valve 8, that is, Since the area where the spring receiver 39 closes a part of the throttle valve 8 does not change, the spring receiver 39 may not close a part of the throttle valve 8.

  Further, as described above, the valve body 37 is urged and bent toward the annular valve seat 34 by the urging force of the coil spring 41 via the valve holding member 38 and acts via the port 33. When the differential pressure between the pressure of R2 and the pressure of the liquid chamber L acting on the back side that is the side opposite to the partitioning member reaches the valve opening pressure, the outer periphery of the valve element 37 bends downward in FIG. As the differential pressure increases, the amount of deflection of the valve element 37 increases and the annular gap formed between the annular valve seat 34 and the valve element 37 increases. In addition, when the coil spring 41 contracts due to the above-described differential pressure, the valve body 37 moves backward together with the valve holding member 38 from the partition member 7 in FIG. 2, and is formed between the annular valve seat 34 and the valve body 37. The annular gap becomes even larger. When the hollow shaft 35 approaches the partition member 7, the axial distance in the vertical direction in FIG. 2 between the spring receiver 39 and the valve pressing member 38 attached to the outer periphery of the shutter 36 is also shortened. The amount of compression (initial load) increases, and the biasing force that biases the valve element 37 by the coil spring 41 increases accordingly. In this way, the valve opening pressure for separating the valve body 37 from the annular valve seat 34 increases as the force for energizing the valve body 37 of the coil spring 41 with the hollow shaft 35 approaching the partition member 7 increases. Thus, the resistance given to the liquid passing through the valve element 9 can be increased.

  Subsequently, when the hollow shaft 35 is pushed downward in FIG. 2 by the turning operation of the adjuster 30 and moved away from the partition member 7, the spring receiver 39 is pushed down by the coil spring 41 and is regulated by the restricting portion 35 d of the hollow shaft 35. It moves downward in the figure while being regulated. On the other hand, since the shutter 36 is pressed against the partition member 7 by the coil spring 41, when the hollow shaft 35 is moved away from the partition member 7 by the operation of the adjuster 30, the shutter 36 and the spring receiver 39 are moved away from each other. The distance between the upper end of the cylindrical portion 36a and the lower end of the cylindrical portion 39a of the spring receiver 39 is increased, and the area where the throttle valve 8 is closed by the shutter 36 and the spring receiver 39 is reduced. That is, when the hollow shaft 35 is separated from the partition member 7 in the axial direction, the opening area that is not blocked by the shutter 36 and the spring receiver 39 of the throttle valve 8 is enlarged, and the throttle valve 8 passes. The resistance given to the liquid flow is reduced.

  Further, when the hollow shaft 35 is moved away from the partition member 7, the axial distance in the vertical direction in FIG. 2 between the spring receiver 39 and the valve pressing member 38 attached to the outer periphery of the shutter 36 becomes longer. The amount of compression (initial load) decreases, and the biasing force that biases the valve element 37 by the coil spring 41 decreases accordingly. Thus, as the force for energizing the valve element 37 of the coil spring 41 is reduced by separating the hollow shaft 35 from the partition member 7 in the axial direction, the valve element 37 is opened away from the annular valve seat 34. The pressure applied to the liquid passing through the valve element 9 can be reduced by reducing the pressure.

  As can be understood from the above, in this embodiment, by rotating the adjuster 30, the hollow shaft 35 is moved in the axial direction to move away from the partition member 7, so that the throttle valve 8. By changing the opening area and the valve opening pressure of the valve element 9, it is possible to simultaneously adjust the resistance applied to the flow of liquid passing through both. More specifically, when the adjuster 30 is rotated in one direction, the opening area of the throttle valve 8 is decreased to increase the resistance in the throttle valve 8 and increase the valve opening pressure of the valve element 9. On the other hand, when the adjuster 30 is rotated in the other direction, the opening area of the throttle valve 8 is increased to reduce the resistance of the throttle valve 8 while reducing the valve opening pressure of the valve element 9. The resistance in the valve element 9 can be reduced by reducing the resistance.

  Therefore, in the present embodiment, the adjustment mechanism 11 abuts on the side of the anti-partition member of the spring receiver 39 provided on the hollow shaft 35 with the spring receiver 39 mounted on the outer periphery, and moves the spring receiver 39 toward the anti-partition member side. For regulating the shaft 35, a feed screw composed of an externally-adjustable adjuster 30 that is a driving means for moving the hollow shaft 35 in the axial direction with respect to the partition member 7 and a screw portion 35 a, and driving the hollow shaft 35. On the other hand, the shutter 36 is configured to be immovable and to increase or decrease the lap area with the throttle valve 8 formed of the long hole with respect to the driving of the hollow shaft 35.

  Next, the operation of the vehicle hydraulic shock absorber D configured as described above will be described. First, when the vehicle hydraulic shock absorber D in which the piston 2 moves upward in FIG. 1 is extended, the expansion side chamber R1 is compressed by the rise of the piston 2 and the liquid in the expansion side chamber R1 is lowered through the damping valve 17. Into the pressure side chamber R2. At that time, since the piston rod 3 retreats from the cylinder 1 and the volume of liquid in which the piston rod 3 retreats in the cylinder 1 is insufficient, the check valve 10 is opened and the liquid is removed from the liquid chamber L. Supplied to the pressure side chamber R2, the free piston 18 moves in the direction in which the air chamber G is expanded to compensate for volume fluctuations in the cylinder 1.

  The check valve 10 is urged by the spring member 42. However, the urging force is set to be extremely weak. In this case, the liquid passes through the check valve 10 with almost no resistance and passes from the liquid chamber L. It moves to the pressure side chamber R2.

  Therefore, during this extension stroke, the vehicle hydraulic shock absorber D exerts an extension side damping force corresponding to the pressure difference between the extension side chamber R1 and the compression side chamber R2 generated when the liquid passes through the damping valve 17 provided in the piston 2. Demonstrate.

  On the other hand, when the vehicle hydraulic shock absorber D in which the piston 2 moves downward in FIG. 1 is compressed, the pressure side chamber R2 is compressed by the lowering of the piston 2, and the liquid in the pressure side chamber R2 passes through the damping valve 17. It flows into the upper extension chamber R1. At that time, since the piston rod 3 enters the cylinder 1 and the volume of liquid into which the piston rod 3 enters in the cylinder 1 becomes excessive, the valve element 9 opens the port 33 for this excess liquid. As a result, the pressure side chamber R2 is discharged to the liquid chamber L, and the free piston 18 moves in a direction in which the air chamber G contracts to compensate for volume fluctuations in the cylinder 1.

  When the piston speed in the compression stroke of the hydraulic shock absorber D for the vehicle is equal to or lower than a predetermined speed, the valve element 9 does not open because the pressure difference between the pressure side chamber R2 and the liquid chamber L is small, and the liquid is only the throttle valve 8. As shown by the solid line a in FIG. 3, the vehicle hydraulic shock absorber D has a damping characteristic peculiar to the throttle valve (a characteristic of the damping force with respect to the piston speed). Demonstrate the damping force. 3 shows a state in which the opening area of the throttle valve 8 and the valve opening pressure of the valve element 9 are set at the center between the upper limit and the lower limit that can be changed by the operation of the adjuster 30.

  Further, when the piston speed in the compression stroke of the vehicle hydraulic shock absorber D exceeds a predetermined speed and the differential pressure between the pressure side chamber R2 and the liquid chamber L reaches the valve opening pressure, the valve element 9 opens and throttles. Since the port 33 in parallel with the valve 8 is opened, the damping characteristic of the vehicular hydraulic shock absorber D is a damping coefficient with respect to the piston speed. Becomes smaller.

  Further, the piston speed becomes high, and the urging force that the coil spring 41 as a spring element urges the valve element 37 toward the partition member 7 is applied by the pressure in the compression side chamber R2 to be compressed. When the coil spring 41 is compressed and the valve body 37 is retracted from the partition member 7 together with the valve restraining member 38, the annular clearance formed between the valve body 37 and the annular valve seat 34 is overcome. The damping coefficient of the vehicular hydraulic shock absorber D has a smaller damping coefficient than the previous one with respect to the piston speed (one-dot chain line c in FIG. 3).

  In this way, the valve element 9 restricts the flow passage area to a small size when the vehicular hydraulic pressure damper D has a piston speed in the compression stroke equal to or lower than a predetermined speed, so that the liquid in the pressure side chamber R2 moves to the liquid chamber L. It becomes difficult to increase the pressure in the pressure side chamber R2 quickly.

  That is, the vehicle hydraulic pressure buffer D rapidly increases the pressure in the compression side chamber R2, and exhibits a compression-side damping force while suppressing a decrease in the pressure field in the extension side chamber R1 and the compression side chamber R2. Therefore, it is possible to eliminate the tendency that the rising of the damping force is insufficient in the initial stage when switching from the expansion stroke to the compression stroke or when the piston speed is low during the compression stroke, and the damping force generation response is improved.

  As described above, while increasing the resistance in the throttle valve 8, the valve opening pressure of the valve element 9 can be increased to increase the resistance in the valve element 9, and the resistance in the throttle valve 8 can be decreased. While the valve opening pressure of the valve element 9 can be reduced and the resistance in the valve element 9 can be reduced, the inclination due to the characteristics of the throttle valve 8 can be changed, and the valve opening timing of the valve element 9 can be changed. It can be changed. Therefore, for example, when the adjuster 30 is rotated to one side to minimize the opening area of the throttle valve 8 and the valve opening pressure of the valve element 9 is maximized, the pressure rise characteristic of the pressure side chamber R2 (relative to the piston speed). As shown by the line Y in FIG. 4 from the characteristic in FIG. 3 (line X in FIG. 4), the resistance given to the liquid passing through the throttle valve 8 is increased. The slope of the characteristic corresponding to the line a is increased, and the pressure loss in the throttle valve 8 is increased. Accordingly, the valve opening timing of the valve element 9 is shifted to the low speed side of the piston speed, and corresponds to the line a in FIG. The characteristic to be output is changed to a characteristic that is output as it is until the valve element 9 is opened. When the adjuster 30 is rotated to the other side to maximize the opening area of the throttle valve 8 while minimizing the valve opening pressure of the valve element 9, the pressure rise characteristic of the pressure side chamber R2 (pressure side chamber relative to the piston speed) As shown by the line Z in FIG. 4 from the characteristic in FIG. 3 (line X in FIG. 4), the resistance given to the liquid passing through the throttle valve 8 is reduced and the line a in FIG. 3 can be reduced, and the valve opening timing of the valve element 9 is shifted to the high speed side of the piston speed by the amount that the pressure loss at the throttle valve 8 is reduced, corresponding to the line a in FIG. This characteristic is such that it is output as it is until the valve opening timing of the valve element 9. That is, by operating the adjuster 30, the pressure increase characteristic of the pressure side chamber R2 can be adjusted in the range of the characteristic indicated by the line Y in FIG.

  Note that the damping characteristic of the vehicle hydraulic shock absorber D is also compensated for the pressure increase in the compression side chamber R2 as described above. Therefore, as shown in FIG. 5, in the range indicated by the line Y1 to the line Z1 in FIG. It can be changed by rotating the adjuster 30.

In this way, since both the throttle valve 8 and the valve element 9 can be adjusted at the same time, it is possible to adjust only the throttle valve 8 or the shock absorber capable of adjusting only the valve element 9 or both. Compared to a shock absorber that must be adjusted independently, the pressure rise characteristic of the pressure side chamber R2 can be adjusted more easily and intuitively, and the pressure side damping force response can be adjusted in the same manner. It can be done easily.

  Further, since there is no need to increase the pressure in the air chamber, the pressure in the cylinder 1 of the vehicle hydraulic shock absorber D does not become excessively high, and the tightening force of the seal member 14 that seals around the piston rod 3 is large. There is no worry that the vehicle occupant perceives a jerky feeling and does not disturb the riding comfort of the vehicle.

  Therefore, according to the vehicle hydraulic shock absorber D of the present invention, the necessary and sufficient damping force can be exhibited with good responsiveness even in the initial stage of the compression stroke without impairing the ride comfort in the vehicle. Note that the predetermined speed at which the flow passage area of the valve element 9 increases can be arbitrarily determined so as to be suitable for the vehicle.

  On the other hand, when the piston speed exceeds a predetermined speed, the flow path area increases, the resistance decreases, and the liquid can move from the pressure side chamber R2 to the liquid chamber L without being limited as much as possible. In this case, the damping force equivalent to that of the conventional single cylinder type hydraulic shock absorber is exhibited.

  In addition, as shown in FIG. 6, the valve element 37 made of a leaf valve is initially bent due to the height difference between the annular valve seat 34 and the valve support portion 36b of the shutter 36 (the height difference in the vertical direction in FIG. 6). In the case of providing, as shown in FIG. 7, the valve body 37 is caused by the pressure of the pressure side chamber R2 acting through the port 33 until the valve body 37 reaches the valve opening pressure at which the valve body 37 separates from the annular valve seat 34. While the outer periphery of 37 is seated on the annular valve seat 34, only the inner peripheral side together with the shutter 36 is lifted from the partition member 7. In this state, since the shutter 36 is lifted from the partition member 7 together with the valve body 37, the opening area of the throttle valve 8 formed in the hollow shaft 35 is reduced. Therefore, in the case where initial deflection is provided in the valve element 37 made of a leaf valve, as shown in FIG. 8, in the case where initial deflection is provided with respect to the damping characteristic when the initial deflection is not provided (broken line in FIG. 8). The throttle valve 8 gradually reduces the opening area until the valve element 9 is opened, so that the pressure loss at the throttle valve 8 increases, and as shown by the solid line in FIG. It rises quickly, that is, the attenuation coefficient can be increased.

In the above description, the throttle valve 8 is an orifice. However, in addition to the orifice, a choke or other throttle valve may be used. For example, when an annular throttle is provided, the upper end of the hollow shaft 35 is not blocked. An annular valve seat is provided in the hollow shaft 35, and a needle shape is formed in the hollow shaft 35 which is axially immovable with respect to the hollow shaft 35 and forms an annular throttle between the annular valve seat and the annular valve seat. When the hollow shaft 35 is moved closer to the partition member 7, the distance between the valve body and the annular valve seat is also approached. Conversely, when the hollow shaft 35 is moved away from the partition member 7, the valve body is moved. A throttle valve having a structure in which the distance between the valve seat and the annular valve seat is also increased may be employed. When a choke is employed for the throttle valve 8, a small diameter portion is provided in the hollow shaft 35 so as to be hollow. slidably inserted in the axial axial immovable with respect to the axis 35 in the small diameter portion Type, the outer circumference of the inner periphery or the axis of the small diameter portion of the hollow shaft 35 may be provided with grooves for forming a choke, the fitting length of the small diameter portion and the shaft by moving the hollow shaft 35 in the axial direction It is also possible to adopt a throttle valve structure that changes the choke length by changing.

  The valve element 9 employs an annular leaf valve as the valve element 37, but a poppet valve or other valve element may be used as long as the valve element is biased by a spring element.

Furthermore, since the throttle valve 8, the valve element 9 and the check valve 10 are accommodated in the hollow portion A of the valve case 4 provided on the side of the cylinder 1 in the above-described manner, the throttle valve 8, the valve element 9 or When the check valve 10 is replaced and the damping characteristic is to be tuned, it is not necessary to disassemble all parts of the vehicle hydraulic shock absorber D, and the throttle valve 8, the valve element 9 and the check valve 10 are taken out from the valve case 4. Tuning can be performed easily and in a short time. Further, the throttle valve 8, the valve element 9, and the check valve 10 are assembled together by the adjuster 30 and the hollow shaft 35 together with the partition member 7 so as not to be separated, thereby constituting a valve assembly. If the adjuster holding member 29 is removed, the throttle valve 8, the valve element 9 and the check valve 10 accommodated in the hollow portion A from the valve case 4 can be easily taken out. Also during assembly, the assembly can be easily performed by inserting the previously assembled valve assembly into the hollow portion A.

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

  The hydraulic shock absorber for a vehicle according to the present invention can be used for a vibration damping application of a vehicle.

DESCRIPTION OF SYMBOLS 1 Cylinder 1a Cylinder flange 1b, 5b, 24 Bolt insertion hole 2 Piston 3 Piston rod 4 Valve case 5 Liquid chamber cylinder 5b Liquid chamber cylinder flange 6 Energizing means 7 Partition member 8 Throttle valve 9 Valve element 10 Check valve 11 Adjustment mechanism 20b Opening 27 Bolt 29 Adjuster holding member 30 Adjuster 30b Screw hole 33 Port 35 Hollow shaft 35a Screw part 35d Restriction part 36 Shutter 37a Through hole 37 Valve body 39 Spring receiver 41 Coil spring 42 as spring element Spring member A Hollow part D For vehicle Fluid pressure buffer L Fluid chamber R1 Stretch side chamber R2 Pressure side chamber

Claims (5)

A cylinder,
A piston slidably inserted into said cylinder,
A piston rod movably inserted into the cylinder and coupled to the piston;
An extension side chamber and a pressure side chamber defined by the piston in the cylinder;
A valve case provided on the side of the cylinder and having a hollow inside;
A liquid chamber cylinder that is connected to the cylinder along the axial direction and forms a liquid chamber that communicates with the pressure side chamber through the hollow portion inside;
And biasing means for biasing the liquid chamber,
A partition member housed in the hollow portion and partitioning the pressure side chamber and the liquid chamber;
A throttle valve which is accommodated in the hollow portion and communicates the pressure side chamber and the liquid chamber and provides resistance to the flow of liquid passing therethrough;
A valve element that is accommodated in the hollow portion and communicates the pressure side chamber and the liquid chamber in parallel with the throttle valve and provides resistance to the flow of liquid passing therethrough,
A check valve that is accommodated in the hollow portion and allows only the flow of liquid from the liquid chamber to the pressure side chamber in parallel with the throttle valve and the valve element;
An adjustment mechanism for simultaneously changing the opening area of the throttle valve and the resistance of the valve element ;
The valve element is disposed on the liquid chamber side of the partition member, and opens and closes an outlet of a port communicating the pressure side chamber and the liquid chamber formed in the partition member, and an anti-partition of the valve body An annular spring receiver disposed on the member side, and a spring element that is interposed between the valve body and the spring receiver and biases the valve body toward the partition member side,
The throttle valve has a bottomed cylindrical shape and is formed with a long hole that opens to the side of the hollow shaft that communicates with the pressure side chamber and communicates with the liquid chamber.
The adjusting mechanism is configured to contact a counter-partitioning member side of the spring receiver provided on the hollow shaft having the spring receiver mounted on an outer periphery thereof, and restrict the movement of the spring receiver to the counter-partitioning member side; Drive means for moving the hollow shaft in the axial direction relative to the partition member; and a shutter that is immovable with respect to the drive of the hollow shaft and increases or decreases the lap area with the elongated hole with respect to the drive of the hollow shaft. , by the driving of the drive means, car dual fluid pressure shock absorber characterized by changing the initial load of the opening area and the spring element of the throttle valve at the same time. A cylinder,
A piston slidably inserted into the cylinder;
A piston rod movably inserted into the cylinder and coupled to the piston;
An extension side chamber and a pressure side chamber defined by the piston in the cylinder;
A valve case provided on the side of the cylinder and having a hollow inside;
A liquid chamber cylinder that is connected to the cylinder along the axial direction and forms a liquid chamber that communicates with the pressure side chamber through the hollow portion inside;
Energizing means for energizing the liquid chamber;
A partition member housed in the hollow portion and partitioning the pressure side chamber and the liquid chamber;
A throttle valve which is accommodated in the hollow portion and communicates the pressure side chamber and the liquid chamber and provides resistance to the flow of liquid passing therethrough;
A valve element that is accommodated in the hollow portion and communicates the pressure side chamber and the liquid chamber in parallel with the throttle valve and provides resistance to the flow of liquid passing therethrough,
A check valve that is accommodated in the hollow portion and allows only the flow of liquid from the liquid chamber to the pressure side chamber in parallel with the throttle valve and the valve element;
An adjustment mechanism for simultaneously changing the opening area of the throttle valve and the resistance of the valve element;
A liquid chamber cylinder flange provided at one end of the liquid chamber cylinder and having a plurality of bolt insertion holes;
A cylinder flange provided at one end of the cylinder and having the same number of bolt insertion holes as the bolt insertion holes provided in the liquid chamber cylinder flange;
A closing member that is provided in the valve case and closes the end of the cylinder and the end of the liquid chamber cylinder and has the same number of bolt insertion holes as the bolt insertion holes provided in the liquid chamber cylinder flange;
The cylinder, the liquid chamber tube, and the closing member are fastened by bolts inserted into the bolt insertion holes in a state where the closing member is interposed between the cylinder and the liquid chamber tube.
A hydraulic shock absorber for vehicles. The valve element is disposed on the liquid chamber side of the partition member, and opens and closes an outlet of a port communicating the pressure side chamber and the liquid chamber formed in the partition member, and an anti-partition of the valve body An annular spring receiver disposed on the member side, and a spring element that is interposed between the valve body and the spring receiver and biases the valve body toward the partition member side,
The throttle valve has a bottomed cylindrical shape and is formed with a long hole that opens to the side of the hollow shaft that communicates with the pressure side chamber and communicates with the liquid chamber.
The adjusting mechanism is configured to contact a counter-partitioning member side of the spring receiver provided on the hollow shaft having the spring receiver mounted on an outer periphery thereof, and restrict the movement of the spring receiver to the counter-partitioning member side; Drive means for moving the hollow shaft in the axial direction relative to the partition member; and a shutter that is immovable with respect to the drive of the hollow shaft and increases or decreases the lap area with the elongated hole with respect to the drive of the hollow shaft. 3. The vehicle hydraulic shock absorber according to claim 2, wherein an opening area of the throttle valve and an initial load of the spring element are simultaneously changed by driving the driving means . The valve case includes an opening that communicates with the hollow portion, and an adjuster holding member that closes the opening,
The drive means has a screw portion provided at the tip of the hollow shaft, and a screw hole that passes through the adjuster holding member and is rotatably provided on the adjuster holding member and is screwed into the screw portion of the hollow shaft. and a adjuster, vehicle hydraulic shock absorber according to claim 1 or 3, characterized in that the external operation enables the adjuster. The check valve is stacked on the partition member side of the valve body, according to claim 1, 3 by the spring member is biased towards the valve body, characterized in that opening and closing a hole provided in the valve body or vehicle hydraulic shock absorber according to 4.

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