JP2021162048A - Damper - Google Patents

Abstract

To provide a damper which enables smooth vehicle height adjustment without needing high processing accuracy.SOLUTION: A damper D of the invention includes: an outer tube 7; a rod 8 which is inserted into the outer tube 7 in such a way so as to be movable in an axial direction; a damper body S which generates a damping force when the outer tube 7 and the rod 8 move relative to each other; an annular first spring seat 3 provided at an outer periphery of the outer tube 7 so as to be movable in the axial direction; a second spring seat 4 connected to the rod 8; a coil spring 5 disposed between the first spring seat 3 and the second spring seat 4; a driving source 6 which may drive the first spring seat 3 relative to the outer tube 7 in the axial direction; a columnar guide rod 1 which is disposed in parallel to the outer tube 7 and connected to the outer tube 7; and a cylindrical bush 2 which is provided at the first spring seat 3 and into which the guide rod 1 is slidably inserted.SELECTED DRAWING: Figure 2

Description

The present invention relates to a shock absorber.

Conventionally, in a vehicle height adjusting device, for example, a lower seat fixed to a cylinder in a shock absorber and a cylindrical motor connected to a shock absorber rod via the vehicle body and arranged on the outer peripheral side of the rod. And a cylindrical nut to which the rotational power of the motor is transmitted, a cylinder body that is screwed into the nut and connected to the upper seat, and a piston body that is connected to the rod, and between the lower seat and the upper seat. It is configured to include a coil spring to be mounted (see, for example, Patent Document 1).

A key groove is provided on the outer periphery of the piston body along the axial direction, and the key provided on the inner circumference of the cylinder body can slide and move in the key groove, so that the cylinder body can move with respect to the piston body. Although it is stopped, it can move in the axial direction. Further, since the cylinder body and the nut are screwed together, when the nut is rotationally driven by the motor, the cylinder body moves up and down with the upper seat with respect to the piston body in the same manner as a feed screw. As a result, the conventional vehicle height adjusting device adjusts the position of the upper seat up and down, and adjusts the position of the vehicle body by expanding and contracting the shock absorber.

Japanese Unexamined Patent Publication No. 2008-308026

In the conventional vehicle height adjustment device, the cylinder body is detented not only to move the cylinder body up and down by the feed screw mechanism, but also to prevent the vehicle height from changing due to the torque transmitted from the coil spring when the coil spring expands and contracts. It is an essential configuration.

As described above, the detent of the cylinder body is realized by inserting the key provided in the cylinder body into the key groove provided in the piston body, but there is an unnecessary gap between the key groove and the key. If there is, the cylinder body and the piston body rattle, so high processing accuracy is required to suppress this rattling.

In addition, when the cylinder body that receives a large torque from the coil spring moves with respect to the piston body, the side wall of the key groove and the side surface of the key rub against each other, so that the friction between the two is large and the movement when adjusting the vehicle height is awkward. turn into.

Therefore, an object of the present invention is to provide a shock absorber capable of smooth vehicle height adjustment without requiring high processing accuracy.

In order to achieve the above object, the shock absorber of the present invention is a shock absorber that exerts a damping force when the outer tube, the rod that is movably inserted in the outer tube in the axial direction, and the outer tube and the rod move relative to each other. It is interposed between the main body, an annular first spring seat provided on the outer circumference of the outer tube so as to be movable in the axial direction, a second spring seat connected to the rod, and the first spring seat and the second spring seat. A suspension spring, a drive source that can drive the first spring seat in the axial direction with respect to the outer tube, and a columnar guide rod that is arranged parallel to the outer tube and connected to one of the outer tube and the first spring seat. And a tubular bush provided on the other side of the outer tube and the first spring seat and into which the guide rod is slidably inserted.

According to the shock absorber configured in this way, the cylindrical guide rod and the tubular bush that is in sliding contact with the outer peripheral surface of the guide rod regulate the rotation of the first spring seat in the circumferential direction, and the guide rod. Since the frictional resistance between the bush and the bush can be reduced and both of them come into contact with each other to guide the movement of the first spring seat, the first spring seat can be smoothly moved in the axial direction, and the first spring seat can be moved. The backlash in the circumferential direction can also be suppressed. Further, it is easy to smoothly finish the outer peripheral surface which is the sliding surface of the guide rod and the inner peripheral surface which is the sliding surface of the bush, and the sliding between the guide rod and the bush without increasing the processing accuracy. Dynamic resistance can be reduced.

Further, an annular seat having an insertion hole through which the outer tube is inserted centering on a position where the first spring seat is eccentric from the center, with the suspension spring as a coil spring, and the end of the suspension spring of the first spring seat abuts. The center of the portion is eccentric toward the center of the first spring seat with respect to the center of the insertion hole, and the bush is provided in the wider space between the seat portion and the insertion hole in the first spring seat. You may. According to the shock absorber configured in this way, the bush is provided on the inner peripheral side of the coil spring in the range between the seat portion and the insertion hole in the first spring seat, whichever has the wider space. The guide rod and bush can be reasonably arranged on the inner circumference of the coil spring without increasing the diameter of the coil spring, and the increase in the outer diameter of the shock absorber can be suppressed.

Further, the bush is provided on the line connecting the portion where the seat portion is most distant from the insertion hole and the center of the insertion hole with respect to the first spring seat and closer to the seat portion. According to the shock absorber D configured in this way, the guide rod and the bush are placed at a position closer to the coil spring than the center of the seat portion where the coil spring is the rotation center of the first spring seat when viewed from the axial direction. Since it can be arranged, the lateral load received by the guide rod and bush is reduced even if torque is received from the coil spring, and the frictional force acting between the guide rod and bush when the first spring seat is moved can be reduced and the guide can be further guided. The load on the rod can be reduced. Since the shock absorber configured in this way is advantageous in terms of strength, it is possible to use a guide rod having a lower rigidity, which can contribute to weight reduction of the shock absorber.

Further, the shock absorber has a head cap in which the shock absorber body is attached to the rod side end of the outer tube and a connecting metal fitting for connecting one end of the guide rod to the head cap, and the drive source is attached to the outer tube. It may have a housing and a movable portion that moves in and out of the housing to displace the first spring seat, and the other end of the guide rod may be connected to the housing of the drive source. According to the shock absorber configured in this way, the guide rod is attached to the outer tube by using the head cap that functions as a bump stopper installed in the existing shock absorber and the drive source provided in the outer tube of the shock absorber. Therefore, the addition of special parts for attaching the guide rod to the outer tube is minimized, and the guide rod can be easily installed. Further, in the shock absorber configured in this way, both ends of the guide rod are attached to the outer tube, so that the guide rod does not tilt even if torque is received from the suspension spring, and the first spring Can guarantee smoother movement of the seat

According to the vehicle height adjusting device and the shock absorber of the present invention, smooth vehicle height adjustment is possible without requiring high processing accuracy.

It is a partial notch side view of the shock absorber in one embodiment. It is a partially enlarged sectional view of the shock absorber in one Embodiment. It is a top view of the 1st spring seat of one Embodiment.

Hereinafter, the shock absorber D of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the shock absorber D in one embodiment is an annular first spring seat provided on the outer periphery of the shock absorber main body S and the outer tube 7 of the shock absorber main body S so as to be movable in the axial direction. 3, the second spring seat 4 connected to the rod 8 of the shock absorber main body S, the coil spring 5 as a suspension spring interposed between the first spring seat 3 and the second spring seat 4, and the first 1 A drive source 6 capable of driving the spring seat 3 in the axial direction with respect to the outer tube 7, a columnar guide rod 1 arranged in parallel with the outer tube 7 and connected to the outer tube 7, and a first spring seat 3. It is provided with a tubular bush 2 into which the guide rod 1 is slidably inserted.

Hereinafter, each part of the shock absorber D will be described in detail. First, the shock absorber main body S will be described. The shock absorber body S has an outer tube 7, a rod 8 slidably inserted into the outer tube 7 in the axial direction, and a slidably inserted into the outer tube 7 to enter the air chamber and the liquid chamber in the outer tube 7. A free piston (not shown) that is slidably inserted into the outer tube 7 and connected to a rod 8 to partition the liquid chamber into an extension side chamber and a compression side chamber, and a piston (not shown) that divides the liquid chamber into an extension side chamber and a compression side chamber. It is provided with a passage (not shown) that communicates with and a damping valve provided in the passage.

Then, the shock absorber main body S generates a damping force on the extension side by giving a resistance to the flow of the liquid from the extension side chamber that is reduced during expansion to the compression side chamber that is expanded by the damping valve, and from the compression side chamber that is reduced during contraction. A damping force on the compression side is generated by giving resistance to the flow of liquid toward the expanding concubine.

The shock absorber main body S is provided with a knuckle bracket B connected to a knuckle (not shown) that rotatably holds the wheels of the vehicle at the lower end of FIG. 1 of the outer tube 7, and is provided at the upper end of FIG. 1 of the rod 8. It is equipped with a mount M that is connected to the vehicle body. Then, the shock absorber main body S is interposed between the vehicle body and the wheels in the vehicle by using the knuckle bracket B and the mount M, and generates a damping force with respect to the relative movement of the vehicle body and the wheels in the vertical direction. Suppresses vibration of the car body and wheels.

In the shock absorber main body S in the present embodiment, the free piston moves in the outer tube 7 according to the volume of the rod 8 that goes in and out of the outer tube 7 at the time of expansion and contraction, and the volume of the air chamber is changed to compensate. It is configured as a single-cylinder shock absorber body. The shock absorber main body S may adopt a structure other than the single cylinder type as long as it can generate a damping force when the rod 8 moves relative to the outer tube 7 in the axial direction. Therefore, the shock absorber main body S includes a cylinder in which the piston and the rod 8 are movably inserted into the outer tube 7, and compensates for the volume of the rod 8 entering and exiting the cylinder between the outer tube 7 and the cylinder. It may be a double-cylinder type shock absorber body provided with a reservoir. In the case of the double cylinder type, the shock absorber main body S is provided with a damping valve at an appropriate position so that a damping force can be generated at the time of expansion and contraction. Further, when the shock absorber main body S is a double cylinder type, a biflow structure in which the liquid moves back and forth between the extension side chamber and the compression side chamber may be adopted, or the liquid circulates in the extension side chamber, the compression side chamber and the reservoir in order. A uniflow structure may be adopted.

Subsequently, as shown in FIGS. 1 to 3, the first spring seat 3 is annular and is arranged on the outer periphery of the outer tube 7, and is an axis that is in the vertical direction in FIG. 1 with respect to the outer tube 7. While moving in the direction, it supports the end 5a which is the lower end of the coil spring 5.

More specifically, as shown in FIG. 3, the first spring seat 3 has a substantially circular shape in a plan view of the first spring seat 3 when viewed from the axial direction, but the position eccentric from the center O3 is set to the center O3a. In addition to being provided with a circular insertion hole 3a that allows the outer tube 7 to be inserted, the end 5a of the coil spring 5 is a circular shape whose center O3b is located between the center O3 and the center O3a of the insertion hole 3a. It is provided with a seat portion 3b to be supported. In this way, the center O3b of the seat portion 3b with which the end 5a of the coil spring 5 of the first spring seat 3 abuts is relative to the center O3a of the insertion hole 3a in a plan view of the first spring seat 3 viewed from the axial direction. Therefore, it is eccentric toward the center O3 of the first spring seat 3. The fact that the center O3b of the seat portion 3b is eccentric toward the center O3 of the first spring seat 3 with respect to the center O3a of the insertion hole 3a means that the distance from the center O3a to the center O3b is larger than the distance from the center O3 to the center O3b. Also means that the center O3b does not need to be arranged on a straight line connecting the center O3a of the insertion hole 3a and the center O3 of the first spring seat 3.

Further, the tubular bush 2 is provided in the first spring seat in the range Z (the range indicated by the hatching of the lattice in FIG. 3) where the space is wider between the seat portion 3b and the insertion hole 3a in the first spring seat. It is provided along the vertical direction in FIG. 2, which is the moving direction of 3. The bush 2 has a cylindrical shape whose inner peripheral surface contacts the outer peripheral surface of the cylindrical guide rod 1, and is mounted in a hole provided in the first spring seat 3. The bush 2 may be made of metal or resin.

In the present embodiment, the bush 2 is on the line L connecting the portion 3b1 in which the seat portion 3b is most distant from the insertion hole 3a and the center O3a of the insertion hole 3a in the range Z of the first spring seat 3. A tubular bush 2 is provided near the seat portion 3b along the vertical direction in FIG. 2, which is the moving direction of the first spring seat 3. That is, the position of the center O2 of the bush 2 when viewed from the axial direction is on the line L and is closer to the seat portion 3b than the midpoint L1 between the portion 3b1 and the edge of the insertion hole 3a in the seat portion 3b. It is provided in the range.

Next, the second spring seat 4 has an annular shape and is connected to the rod 8 via a mount M provided at the upper end of the rod 8 of the shock absorber main body S in FIG. A coil spring 5 as a suspension spring arranged on the outer periphery of the shock absorber main body S is interposed between the second spring seat 4 and the first spring seat 3. The second spring seat 4 may be attached to the vehicle body of a vehicle (not shown) instead of the mount M, and may be connected to the rod 8 via the vehicle body and the mount M.

The upper end of the coil spring 5 is supported by the second spring seat 4 in FIG. 1, and the lower end in the middle of FIG. 1 is supported by the first spring seat 3. It is working. Then, when the shock absorber body S is interposed between the vehicle body and the wheels, the coil spring 5 receives the load of the vehicle body and contracts to exert an elastic force to elastically support the vehicle body. Therefore, in this case, the first spring seat 3 is a lower spring seat arranged below the coil spring 5, and the second spring seat 4 is an upper spring seat arranged above the coil spring 5. ing.

In the present embodiment, the drive source 6 is a hydraulic jack, and is provided in a tubular housing 61 mounted on the outer periphery of the outer tube 7 and having an annular jack chamber J and a jack chamber J in the housing 61. The ram 62 as a movable part that is accommodated and can enter and exit the jack chamber J and abuts on the lower end surface on the inner peripheral side of FIG. 2 of FIG. 2, and the liquid is sucked from the tank 63 into the jack chamber J. A pump 64 capable of supplying the pump 64, an on-off valve 65 capable of discharging the liquid from the jack chamber J to the tank 63, and a check valve 66 for preventing the backflow of the liquid from the jack chamber J to the pump 64 are provided.

The housing 61 has a cylindrical inner case 67 having a flange 67d at the lower end in FIG. 2 and mounted on the outer periphery of the outer tube 7, and an annular jack chamber J provided on the outer periphery of the inner case 67 together with the inner case 67. It includes an outer case 68 to be formed.

The inner case 67 includes a cylindrical case body 67a forming the jack chamber J, a guide portion 67b having a thinner cylindrical shape than the case body 67a rising from the inner circumference of the upper end of the case body 67a, and the upper end of FIG. 2 of the case body 67a. A seal ring 67c provided on the outer periphery and a flange 67d protruding from the outer periphery of the lower end in FIG. 2 of the case main body 67a are provided. The outer case 68 is cylindrical and has an axial length substantially the same as that of the case body 67a, and the inner peripheral diameter of the upper end portion in FIG. 2 is a small diameter to form a small diameter portion 68a. A seal ring 68b is provided on the inner circumference of the small diameter portion 68a, and the inner circumference of the lower end in FIG. 2 is fitted to the outer circumference of the flange 67d of the inner case 67 and mounted on the outer circumference of the inner case 67. Further, the outer case 68 includes a bracket 68c having a screw hole 68d provided on the outer periphery of the lower end along the axial direction which is the vertical direction.

When the outer case 68 is attached to the inner case 67, an annular jack chamber J is formed between the inner case 67 and the outer case 68. The jack chamber J is annular and opens from above the housing 61 and is provided along the axial direction of the housing 61. The ram 62 has a cylindrical shape and is inserted into the jack chamber J, its inner circumference is in sliding contact with the outer periphery of the case body 67a of the inner case 67, and a flange-shaped stopper 62a is provided on the outer periphery of the lower end in FIG. There is. The inner circumference of the ram 62 is in sliding contact with the seal ring 67c of the inner case 67, and the outer circumference of the ram 62 is in sliding contact with the seal ring 68b of the outer case 68. The upper end opening of J is closed in a sealed state.

The jack chamber J communicates with the pump 64 and the tank 63, respectively, through the pipelines 69 and 70, respectively. Therefore, when the pump 64 is driven to supply the liquid to the jack chamber J with the on-off valve 65 closed, the ram 62 is pushed out from the jack chamber J and moves relative to the housing 61 upward in FIG. 1 Push up the spring seat 3 upward in FIG. When the stopper 62a of the ram 62 continues to drive the pump 64 and comes into contact with the small diameter portion 68a of the outer case 68, the movement of the ram 62 further upward is restricted. Although not shown, if a relief valve is provided to discharge the liquid to the tank 63 when the pressure in the jack chamber J exceeds a predetermined pressure, the pump 64 can be operated in a state where the movement of the ram 62 is regulated by the stopper 62a. Even if the driving is continued, the pressure in the jack chamber J does not become excessive. Further, when the pump 64 is stopped, the on-off valve 65 is opened, and the liquid in the jack chamber J is discharged to the tank 63, the ram 62 receives the load from the coil spring 5 via the first spring seat 3 and the ram 62 is inside the jack chamber J. And moves downward in FIG. 2 with respect to the housing 61. When the on-off valve 65 is opened in this way, the first spring seat 3 moves downward together with the ram 62.

Further, even if the ram 62 in the drive source 6 moves up and down, the guide portion 67b in the housing 61 always faces the inner circumference of the first spring seat 3, and an excessive lateral force is input to the first spring seat 3. Even if this is done, care is taken so that the first spring seat 3 does not interfere with the outer circumference of the outer tube 7 in the shock absorber main body S.

The drive source 6 is a hydraulic jack in the present embodiment, and drives the ram 62, which is a movable portion, to move the first spring seat 3 in the axial direction. It may be a jack using. Further, the drive source 6 is provided below the first spring seat 3, but if it does not interfere with the coil spring 5, it is above the first spring seat 3 in FIG. 1 and of the outer tube 7. It may be arranged on the outer circumference.

In the present embodiment, the guide rod 1 is hung on the housing 61 in the drive source 6 and the connecting metal fitting 10 provided on the annular head cap 9 attached to the rod side end at the upper end in FIG. 2 of the outer tube 7. It is handed over and fixed to the outer tube 7 in a parallel posture. The head cap 9 functions as a bump stopper facing the bump cushion 12 mounted on the outer periphery of the upper end of the rod 8. When the shock absorber D contracts to the vicinity of the stroke end on the contraction side, the bump cushion 12 abuts on the head cap 9 and is compressed, exerting an elastic force that prevents further contraction of the shock absorber D, and is the most of the shock absorber D. It cushions the impact during contraction.

More specifically, as shown in FIG. 2, the guide rod 1 projects axially from each of the cylindrical rod body 1a slidably inserted into the bush 2 and the upper and lower ends of the rod body 1a. It is provided with screw shafts 1b and 1c. The guide rod 1 may be solid or hollow as long as it has a columnar outer shape.

The connecting metal fitting 10 is integrated with the head cap 9 by welding, and is provided with a hole 10a extending radially from the head cap 9 and allowing the screw shaft 1b of the guide rod 1 to be inserted at the tip.

To attach the guide rod 1 to the outer tube 7, the following may be performed. After mounting the drive source 6 on the outer circumference of the outer tube 7 of the shock absorber body S, the screw shaft 1c of the guide rod 1 is screwed into the screw hole 68d of the bracket 68c of the housing 61, and the guide rod 1 is screwed through the drive source 6. The lower end is connected to the shock absorber body S. The guide rod 1 is positioned at a position corresponding to the bush 2 of the first spring seat 3 when the shock absorber main body S is viewed from the axial direction. Subsequently, the first spring seat 3 is brought closer from above the shock absorber main body S, the outer tube 7 is inserted into the insertion hole 3a of the first spring seat 3, and the guide rod 1 is inserted into the bush 2. The first spring seat 3 is arranged on the outer periphery of the outer tube 7 and is brought into contact with the upper end of the ram 62.

Further, when the head cap 9 is fitted to the upper end of the outer tube 7 from above the outer tube 7, the screw shaft 1b of the guide rod 1 is inserted into the hole 10a of the connecting metal fitting 10 fixed to the head cap 9. When the nut 11 is screwed into the screw shaft 1b and tightened, the connecting metal fitting 10 is sandwiched between the rod body 1a of the guide rod 1 and the nut 11, and the upper end of the guide rod 1 is fixed to the outer tube 7.

In this way, the upper end of the guide rod 1 is fixed to the outer tube 7 via the connecting metal fitting 10 and the head cap 9, and the lower end is fixed to the outer tube 7 via the housing 61 of the drive source 6 and is fixed to the outer tube 7. On the other hand, it is fixed in a parallel arrangement.

The bush 2 is in sliding contact with the outer periphery of the guide rod 1, and the guide rod 1 and the bush 2 have the first spring even if the torque generated when the coil spring 5 expands and contracts acts on the first spring seat 3. It functions as a detent to prevent the seat 3 from rotating in the circumferential direction, allows the first spring seat 3 to move in the vertical direction, and guides the movement in the vertical direction.

Hereinafter, the operation of the shock absorber D configured as described above will be described. The shock absorber D is interposed between the vehicle body and the wheels in a vehicle (not shown) by using the mount M of the shock absorber main body S and the knuckle bracket B. When the shock absorber D is interposed between the vehicle body and the wheels, as described above, the coil spring 5 receives the load of the vehicle body and is compressed to exert an elastic force to elastically support the vehicle body.

Then, when the wheels move up and down by the input from the road surface while the vehicle is running and the vehicle body and the wheels move relative to each other in the vertical direction, the shock absorber body S expands and contracts to prevent the relative movement between the vehicle body and the wheels. The shock absorber D exerts its force and suppresses the vibration of the vehicle body and the wheels.

When raising the height of the vehicle body, that is, the vehicle height, the on-off valve 65 of the drive source 6 in the shock absorber D is closed to drive the pump 64 to supply the liquid to the jack chamber J and raise the ram 62. .. As the ram 62 rises, the first spring seat 3 that comes into contact with the ram 62 is pushed up and moves upward in FIG. 1, and the position that supports the lower end of the coil spring 5 is displaced upward. The coil spring 5 is compressed in accordance with the load of the vehicle body, but since the weight of the vehicle body does not change even if the first spring seat 3 is raised, the compression amount of the coil spring 5 does not change either, and the first spring seat 3 The height of the vehicle increases by the amount of increase.

On the other hand, when the vehicle height is lowered, the pump 64 of the drive source 6 in the shock absorber D is stopped, the on-off valve 65 is opened, the liquid is discharged from the jack chamber J to the tank 63, and the ram 62 is lowered. Since the first spring seat 3 receives a downward load from the coil spring 5, the lowering of the ram 62 causes the first spring seat 3 that comes into contact with the ram 62 to both lower and move downward in FIG. 1, and the coil spring. The position supporting the lower end of 5 is displaced downward. The coil spring 5 is compressed in accordance with the load of the vehicle body, but since the weight of the vehicle body does not change even if the first spring seat 3 is lowered, the compression amount of the coil spring 5 does not change either, and the first spring seat 3 The vehicle height is lowered by the amount of the descent.

The shock absorber D includes a bush 2 provided on the first spring seat 3 and a guide rod 1 arranged in parallel with the outer tube 7 and slidably inserted into the bush 2. In this way, the peripheral surface of the columnar guide rod 1 is slidably inserted into the bush 2, and the first spring seat 3 is axially prevented from rotating in the circumferential direction with respect to the outer tube 7. Only movement is allowed. Then, since the first spring seat 3 is prevented from rotating by the cylindrical guide rod 1 and the tubular bush 2 that is in sliding contact with the outer peripheral surface of the guide rod 1, the frictional force generated between the guide rod 1 and the bush 2 is generated. Is reduced as compared with the conventional structure in which the key and the key groove prevent the rotation of the first spring seat 3, so that the first spring seat 3 can smoothly move in the axial direction while being prevented from rotating with respect to the outer tube 7.

In this way, the shock absorber D is the shock absorber body S that exerts a damping force when the outer tube 7, the rod 8 that is movably inserted into the outer tube 7 in the axial direction, and the outer tube 7 and the rod 8 move relative to each other. An annular first spring seat 3 provided on the outer periphery of the outer tube 7 so as to be movable in the axial direction, a second spring seat 4 connected to the rod 8, and the first spring seat 3 and the second spring seat 4. A coil spring (suspension spring) 5 interposed between them, a drive source 6 capable of driving the first spring seat 3 in the axial direction with respect to the outer tube 7, and an outer tube 7 arranged in parallel with the outer tube 7. It includes a columnar guide rod 1 to be connected, and a tubular bush 2 provided on the first spring seat 3 and into which the guide rod 1 is slidably inserted.

In the shock absorber D configured in this way, the cylindrical guide rod 1 and the tubular bush 2 that is in sliding contact with the outer peripheral surface of the guide rod 1 regulate the rotation of the first spring seat 3 in the circumferential direction. , The frictional resistance between the guide rod 1 and the bush 2 can be reduced, and both of them come into contact with each other to guide the movement of the first spring seat 3, so that the first spring seat 3 can be smoothly moved in the axial direction. At the same time, play in the circumferential direction of the first spring seat 3 can be suppressed.

Further, it is easy to smoothly finish the outer peripheral surface which is the sliding surface of the guide rod 1 and the inner peripheral surface which is the sliding surface of the bush 2, and the guide rod 1 and the bush 2 can be processed without increasing the processing accuracy. The sliding resistance between can be reduced. From the above, according to the shock absorber D of the present embodiment, smooth vehicle height adjustment is possible without requiring high processing accuracy.

Further, according to the shock absorber D of the present embodiment, the guide rod 1 and the bush 2 can form a detent for the outer tube 7 of the first spring seat 3, so that the structure is simple and the existing shock absorber D can be used. There is an advantage that the vehicle height adjustment function can be implemented by adding a few parts.

Further, according to the shock absorber D of the present embodiment, since the bush 2 is provided on the first spring seat 3, even if the bush 2 is long, it does not interfere with the expansion and contraction of the shock absorber main body S. By lengthening 2 reasonably, not only the backlash of the first spring seat 3 in the circumferential direction but also the backlash that tilts with respect to the axial direction can be suppressed.

Further, in the shock absorber D of the present embodiment, most of the vehicle height adjusting device including the guide rod 1, the bush 2, the first spring seat 3, the second spring seat 4, and the jack portion in the drive source 6 is the shock absorber main body. Since it is integrated with S, most of the vehicle height adjustment device can be installed in the vehicle simply by installing the shock absorber D between the vehicle body and the wheels, and the vehicle height adjustment device can be easily installed in the vehicle. Not only that, since most of the vehicle height adjusting device can be arranged on the outer periphery of the shock absorber main body S, it is not necessary to require the vehicle for a dedicated mounting space for the vehicle height adjusting device. Therefore, according to the shock absorber D configured in this way, it is possible to improve the mountability of the vehicle height adjusting device on the vehicle.

Although not shown, in the shock absorber D of the present embodiment, the bush 2 is provided on the first spring seat 3 and the guide rod 1 is provided on the outer tube 7, but the guide rod 1 is provided on the first spring seat 3. The guide rod 1 may be provided in parallel with the outer tube 7 while holding the upper end of the bush 2, and the bush 2 may be attached to the outer tube 7. Even in this way, by inserting the guide rod 1 into the bush 2, the first spring seat 3 is prevented from rotating with respect to the outer tube 7, and smooth vehicle height adjustment is possible without requiring high processing accuracy. Become. Further, even if the shock absorber D is configured in this way, the guide rod 1 and the bush 2 can form a detent for the outer tube 7 of the first spring seat 3, so that the structure is simple and the existing shock absorber D can be used. There is an advantage that the vehicle height adjustment function can be implemented by adding a few parts. In the structure shown in FIG. 1 in which the bush 2 is provided on the first spring seat 3 and the guide rod 1 is provided on the outer tube 7, the guide rod 1 which is longer than the bush 2 moves up and down as the shock absorber D expands and contracts. Therefore, there is less concern about interference with parts arranged around the outer tube 7 of the shock absorber D of the vehicle, and the space for mounting the shock absorber D on the vehicle can be saved.

Further, in the shock absorber D of the present embodiment, the suspension spring is a coil spring 5, and the first spring seat 3 has an insertion hole 3a through which the outer tube 7 is inserted centering on a position eccentric from the center O3. Then, the center O3b of the annular seat portion 3b with which the end 5a of the coil spring 5 of the first spring seat 3 abuts is eccentric toward the center O3 of the first spring seat 3 with respect to the center O3a of the insertion hole 3a, and the bush 2 is provided in the range Z of the first spring seat 3 between the seat portion 3b and the insertion hole 3a, whichever has the wider space. As described above, according to the shock absorber D of the present embodiment, there is a space between the seat portion 3b and the insertion hole 3a in the first spring seat 3 where the bush 2 is on the inner peripheral side of the coil spring 5 and is on the inner peripheral side. Since it is provided in the wider range Z, the guide rod 1 and the bush 2 can be reasonably arranged on the inner circumference of the coil spring 5 without increasing the diameter of the coil spring 5, and the outer diameter of the shock absorber D can be increased. Can be suppressed.

Further, in the shock absorber D of the present embodiment, the bush 2 is on the line L connecting the first spring seat 3 with the portion 3b1 at which the seat portion 3b is most distant from the insertion hole 3a and the center O3a of the insertion hole 3a. Therefore, it is provided near the seat portion 3b. According to the shock absorber D configured in this way, the coil spring 5 is separated from the center O3b of the seat portion 3b, which is the rotation center of the first spring seat 3, when viewed from the axial direction. Since the guide rod 1 and the bush 2 can be arranged at a position close to the above, the lateral load received by the guide rod 1 and the bush 2 is reduced even if torque is received from the coil spring 5, and the guide rod is moved when the first spring seat 3 is moved. The frictional force acting between 1 and the bush 2 can be reduced, and the load on the guide rod 1 can be further reduced. As described above, according to the shock absorber D of the present embodiment, since it is advantageous in terms of strength, the guide rod 1 having lower rigidity can be used, which can contribute to the weight reduction of the shock absorber D.

Further, in the shock absorber D of the present embodiment, the head cap 9 in which the shock absorber main body S is attached to the rod 8 side end of the outer tube 7 and the screw shaft (one end) 1b of the guide rod 1 are connected to the head cap 9. A guide having a housing 61 in which the drive source 6 is mounted on the outer tube 7 and a ram (movable portion) 62 that moves in and out of the housing 61 to displace the first spring seat 3. The screw shaft (other end) 1c of the rod 1 is connected to the housing 61 of the drive source 6. According to the shock absorber D configured in this way, the guide rod uses the head cap 9 that functions as a bump stopper installed in the existing shock absorber and the drive source 6 provided in the outer tube 7 of the shock absorber D. Since 1 is attached to the outer tube 7, the addition of special parts for attaching the guide rod 1 to the outer tube 7 is minimized, and the guide rod 1 can be easily installed. Further, in the shock absorber D configured in this way, since both ends of the guide rod 1 are attached to the outer tube 7, the guide rod 1 is tilted even if torque is received from the coil spring (suspension spring) 5. It is possible to guarantee smoother movement of the first spring seat 3.

Although the preferred embodiments of the present invention have been described in detail above, they can be modified, modified, and modified as long as they do not deviate from the claims.

1 ... Guide rod, 1b ... Screw shaft (one end of the guide rod), 2 ... Bush, 3 ... First spring seat, 3a ... Insert hole, 3b ... Seat part, 4 ... 2nd spring seat, 5 ... Coil spring (suspended spring), 5a ... Coil spring end, 6 ... Drive source, 7 ... Outer tube, 8 ... Rod, 9 ...・ ・ Head cap, 10 ・ ・ ・ Connecting bracket, 61 ・ ・ ・ Housing, 62 ・ ・ ・ Ram (moving part), D ・ ・ ・ Shuffler, O3 ・ ・ ・ Center of 1st spring seat, O3a ・ ・ ・Center of insertion hole, O3b ... Center of seat, S ... Shock absorber body

Claims (4)

An outer tube, a rod that is movably inserted into the outer tube in the axial direction, and a shock absorber body that exerts a damping force when the outer tube and the rod move relative to each other.
An annular first spring seat provided on the outer circumference of the outer tube so as to be movable in the axial direction,
The second spring seat connected to the rod and
A suspension spring interposed between the first spring seat and the second spring seat,
A drive source capable of driving the first spring seat in the axial direction with respect to the outer tube,
A columnar guide rod arranged in parallel with the outer tube and connected to one of the outer tube and the first spring seat,
A shock absorber provided on the other side of the outer tube and the first spring seat and provided with a tubular bush into which the guide rod is slidably inserted. The suspension spring is a coil spring and
The first spring seat has an insertion hole through which the outer tube is inserted centering on a position eccentric from the center.
The center of the annular seat portion with which the end of the suspension spring of the first spring seat abuts is eccentric toward the center of the first spring seat with respect to the center of the insertion hole.
The shock absorber according to claim 1, wherein the bush is provided in a range of a wider space between the seat portion and the insertion hole in the first spring seat. The bush is provided on a line connecting the portion of the seat portion most distant from the insertion hole and the center of the insertion hole with respect to the first spring seat, and is provided closer to the seat portion. The shock absorber according to claim 2. The shock absorber main body has a head cap attached to the rod side end of the outer tube and a connecting metal fitting for connecting one end of the guide rod to the head cap.
The drive source has a housing mounted on the outer tube and a movable portion that moves in and out of the housing to displace the first spring seat.
The shock absorber according to any one of claims 1 to 3, wherein the other end of the guide rod is connected to the housing of the drive source.

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