JP2001010322A - Hydraulic buffer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate mounting of a remote control member, such as a wire cable, on an adjuster by rotating the adjuster, rotating a cam cylinder to switch a spring constant, without movement in a vertical direction. SOLUTION: A main spring 21 and a subspring 20 are disposed in series between a cylinder 1 and a piston rod 3 with an intermediate spring support 22 nipped therebetween. A stopper 23 is fixed at the outer periphery of a cylinder body 15 fixed at the piston rod 3, and a cam cylinder 24 provided with an insertion part 24a where the stopper 23 is axially movable forward and backward and a lock part 24b to lock forward and backward movement thereof is axially fixed at the intermediate spring support 22 and mounted rotatably in a reciprocating manner. An opening 14b is peripherally formed in a spring support 14 to support the subspring 20. An adjuster inserted in the opening part 14b and provided with an engaging part 26a to effect reciprocating rotation of a cam cylinder is situated rotatably in a reciprocating manner based on the piston rod 3 and axially immovably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic shock absorber for a vehicle in which the spring constant of a suspension spring can be switched between when a single person is riding and when two people are riding or the load is increased. The present invention relates to a hydraulic shock absorber suitable for use in wheeled vehicles, three-wheeled vehicles, four-wheeled buggy vehicles, and the like.

[0002]

2. Description of the Related Art As a hydraulic shock absorber which changes a spring constant of a suspension spring according to a change in a load,
There is one disclosed in JP-A-4-189693. In the hydraulic shock absorber described in this publication, a cylindrical cam 16 is rotatably mounted on an upper portion of a cylinder 8S, and the cam 16 forms an uneven cam surface 16C having different heights at an upper edge thereof. , A pair of arms 20 provided on the cam 16 for engagement with the cam receiver 19 welded to the surface of the cylinder 8S.
By rotating the main coil spring 9a and the sub-coil spring 9b, or by locking the operation of the sub-coil spring 9b.
The characteristic of a is obtained.

[0003]

However, in the hydraulic shock absorber described in this publication, the pair of arms 20 provided on the cam 16 move in the vertical direction when rotating, so that a wire cable, It is difficult to rotate by attaching a remote operation member such as an operation rod or an electromagnetically driven plunger. In addition, the occupant must get out of the vehicle once and adjust the coil spring adjusting mechanism with the seat 4 separated or opened. That is, the spring constant is switched in a state where the shock absorber 5 is once returned to the maximum extension state. Therefore, in the riding state, the two-person riding is performed by a remote operating member such as a wire cable from the soft spring constant at the time of one riding. Alternatively, it is not possible to switch to a hard spring constant such as when the load increases.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and a first problem is that an adjuster such as an arm for rotating a cam does not move in the vertical direction. An object of the present invention is to provide a hydraulic shock absorber provided with a spring constant switching mechanism that can easily rotate by attaching a remote operation member such as a wire cable, an operation rod, and an electromagnetically driven plunger.

Another object is to provide a variable spring constant mechanism that can switch from a soft spring constant for a single rider to a hard spring constant for a double rider or when the load increases, while the rider is still riding. To provide a hydraulic shock absorber.

[0006]

According to the first aspect of the present invention, a main spring and a sub spring are sandwiched between a cylinder and a piston rod which slides in the cylinder via a piston with an intermediate spring receiver interposed therebetween. In a hydraulic shock absorber arranged in series and supporting a main spring and a sub-spring via a spring receiver between a cylinder and a piston rod,
A cam cylinder having a stopper fixed to a cylinder or an outer periphery of the cylinder that is non-rotatably attached to the piston rod and having a penetrating portion that allows the stopper to reciprocate in the axial direction and a lock portion that prevents retraction is formed by the intermediate spring support. In contrast, an axially immovable and relatively rotatably provided, an opening is formed in a circumferential direction in a spring receiver that supports the sub-spring on a piston rod or a cylinder, and is inserted through the opening,
An adjuster slidable with the cam cylinder, and provided with an engaging portion for rotating the cam cylinder, is provided so as to be reciprocally rotatable with respect to the piston rod or cylinder, and is immovable in the axial direction. The spring constant is changed by switching between the insertion portion and the lock portion of the cam cylinder with respect to the stopper.

According to a second aspect of the present invention, in addition to the first aspect of the present invention, the position of the stopper due to the bending of the main spring and the sub-spring at the time of riding 1G is determined by the lock portion and the lock portion. A spring constant of the sub-spring is set to be larger than a spring constant of the main spring so as to be separated in an axial direction from a position of a connecting portion connecting the insertion portions.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the adjuster is remotely operated.

The present invention described in claim 4 provides the present invention according to claims 1 to 3.
In the present invention described in any one of the above, a detent mechanism is further provided between the adjuster and the piston rod mounting member or the cylinder.

The present invention according to claim 5 provides the present invention according to claims 1-4.
In the present invention described in any one of the above, the cylindrical body non-rotatably attached to the piston rod is a dust cover.

[0011]

The variable spring constant mechanism of the hydraulic shock absorber according to the present invention operates as follows.

When the adjuster is rotated, the engaging portion of the adjuster rotates the cam cylinder, and the positions of the cam cylinder insertion portion and the lock portion with respect to the stopper on the outer periphery of the cylinder fixed to the piston rod are switched. When a single passenger is riding, the insertion portion of the cam cylinder is set at the position of the stopper, the sub-spring and the main spring are compressed, and a soft spring characteristic obtained by combining the spring characteristics of both springs is obtained. When the state changes from the state of single-person riding to the state of two-person riding or an increase in the load, the occupant turns the adjuster to set the lock portion of the cam cylinder to a position facing the stopper. And when it becomes a state such as when two passengers or the load increases,
The compression of the sub-spring is locked and only the main spring is compressed, so that a hard spring characteristic is obtained. According to the present invention, in this case, since the adjuster does not move in the vertical direction, it is easy to attach the remote control member to the adjuster. In addition, since the cam cylinder is rotatably attached to the intermediate spring receiver, no load is applied to the spring and a large operation force is not required for the rotation operation.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially cutaway front view of the hydraulic shock absorber according to the present invention, showing the most extended state when the stopper is set in the insertion portion of the cam cylinder.
1 is an enlarged view of a main part of FIG. 1, FIG. 3 is a side view showing a part of FIG. 1 cut away, FIG. 4 is a top view of FIG. 3, FIG. 5 is a top view showing an upper spring support, and FIG. FIG. 7 is a front view showing a complete state in which the receiver, the cylinder, and the stopper are fixed.
A sectional view, FIG. 8 is an enlarged view showing a leaf spring of the detent mechanism of FIG. 7, FIG. 9 is a front view showing a piston rod mounting member,
10 is a bottom view of FIG. 9, FIG. 11 is a top view showing the adjuster, FIG. 12 is a front view of the adjuster of FIG. 11, and FIG. 13 is a developed view of the cam cylinder.

As shown in FIGS. 1 and 2, a hydraulic shock absorber 10 has a piston rod 3 slidably inserted through a piston 2 into a cylinder 1 in which hydraulic oil is sealed. 3 slides to generate a damping force. A piston rod mounting member 4 is screwed and fixed to an upper portion of the piston rod 3 with a lock nut 9, and a mounting eye 5 for mounting to the vehicle body side frame is fixed to an upper end of the piston rod mounting member 4 by welding. At the lower end of the cylinder 1, a mounting eye 6 for mounting to the axle side member is fixed by welding. In each of the mounting eyes 5 (6), a collar 11 (12) is provided with a rubber bush 7 (8) interposed therebetween, and through bolts (not shown) are inserted through these collars 11 (12) to Are attached to the vehicle body frame side or the axle side, respectively.

Lower outer periphery 4a of piston rod mounting member 4
9 and 10, a pair of cutouts 4c and 4d cut in parallel are formed.
d, outer periphery 4a of the lower part of the piston rod mounting member 4
The upper spring receiver 14 shown in FIGS. The upper end of the cylindrical tube 15 is fixed to the lower end surface of the upper spring support 14 by welding, and a pair of stoppers 23 are fixed to the outer periphery of the tube 15 by welding with the central axis of the tube 15 symmetrical. You. The cylindrical body 15 covers the outer circumference of the piston rod 3 and extends to the outer circumference of the cylinder 1 and also serves as a dust cover for protecting the piston rod 3 from earth and sand.

A stopper ring 16 is fitted in an annular groove 1a formed on the outer periphery of the lower portion of the cylinder 1, and a lower spring receiver 17 is provided on the stopper ring 16.

A sub-spring 20 and a main spring 21 are provided in series between the upper spring receiver 14 and the lower spring receiver 17 with an intermediate spring receiver 22 interposed therebetween.
The upper spring receiver 14 contacts the lower step 4e of the piston rod mounting member 4 to support the upper end of the sub-spring 20 on the piston rod 3 side, and the lower spring receiver 17 contacts the stopper ring 16 to lower the lower end of the main spring 21. Are supported on the cylinder 1 side, and both springs 20 and 21 urge the piston rod 3 and the cylinder 1 in the extending direction.

A bump rubber 13 is mounted on the lower end surface of the upper spring support 14 to impinge on the upper end surface of the cylinder 1 at the time of the most compression to provide a cushioning effect.

Sub spring 20 and main spring 2
A cylindrical cam cylinder 24 is in contact with the intermediate spring receiver 22 sandwiched between the cam springs 1, and a stopper ring 25 is fitted around the outer periphery of the lower end of the cam cylinder 24. Another intermediate spring support 22 ′ supporting the lower end of the sub-spring 20 is provided on the intermediate spring support 22.
The inner circumference of 2 ′ stands up and is locked on a stopper ring 25 on the outer circumference of the cam cylinder 24, and the outer circumference is bent downward and locked on the outer circumference of the intermediate spring receiver 22. Therefore, the cam cylinder 24 to which the stopper ring 25 is fitted is moved upward by the intermediate spring receiver 22 '.
The downward movement is prevented by the intermediate spring receiver 22, and the intermediate spring receiver 22 is fixed to the intermediate spring receivers 22 and 22 'so as not to move in the axial direction, and is attached so as to be capable of relative rotation.

As shown in the developed view of FIG. 13, the cam cylinder 24 has a pair of stoppers 23 formed at a position deeper in the axial direction from the upper end and fixed to the outer periphery of the cylinder 15 so as to be able to advance and retreat in the axial direction. And a lock portion 24 formed at a position axially shallow from the upper end to prevent the stopper 23 from moving forward and backward.
b are formed symmetrically with respect to the center axis of the cam cylinder 24 via the connecting portion 24c in the circumferential direction.
6 and a pair of engaging grooves 24 slidable with respect to each other.
d is formed.

As shown in FIG. 5, a pair of arc-shaped openings 14b penetrating in the axial direction are formed in the upper spring receiver 14 in the circumferential direction.

Upper outer periphery 4b of piston rod mounting member 4
The annular adjuster 2 as shown in FIGS.
The sixth annular portion 26b is mounted between the upper step portion 4f of the piston rod mounting member and the upper spring receiver 14. A pair of claw-shaped engagement portions 26a are formed in the lower part of the annular portion 26b of the adjuster 26 in the axial direction. The pair of engagement portions 26a are formed in a pair of arc-shaped openings 14b formed in the upper spring receiver 14. And engages with a pair of engagement grooves 24 d formed in the cam cylinder 24. Then, each engaging portion 26a of the adjuster 26 reciprocates at a predetermined angle in each opening 14b of the upper spring receiver 14, and reciprocates the cam cylinder 24.

As shown in FIGS. 3 and 4, a pair of arms 26c are formed on the outer periphery of the annular portion 26b of the adjuster 26. The arm 26c stands upright, and a wire cable is inserted into two holes 26e of the arm 26c. Cable heads 31, 31 'fixed to the ends of the wires 27, 27' are fitted, and cable heads (not shown) fixed to the other ends of the wire cables 27, 27 'are provided near the driver's seat. The adjuster 26 is reciprocally rotated by operating the operating member in a reciprocating manner by fitting into the two holes of the illustrated pulley-shaped operating member, and the cam cylinder 24 engaged with the adjuster 26 is fixed at a predetermined angle. , So that the insertion portion 24a and the lock portion 24b of the cam cylinder 24 can be switched.

7, a detent mechanism 29 is provided between the inner circumference of the annular portion 26b of the adjuster 26 and the upper inner circumference 4b of the piston rod mounting member 4, as shown in FIG. Can be That is, a pair of concave portions 26d whose inner sides are opened are formed axially symmetrically in the annular portion 26b of the adjuster 26, and the upper outer periphery 4b of the piston rod mounting member 4 in which the annular portion 26b of the adjuster 26 is rotatably fitted.
A pair of notches 4g, 4g 'and 4h, 4h' are formed axially symmetric. And a pair of notches 4g, 4g 'and 4
h, 4h 'are the insertion portion 24a of the cam cylinder 24 and the lock portion 24.
It is formed corresponding to the position of b.

The annular portion 26 of the adjuster 26
A pair of bowl-shaped leaf springs 27 each having a protrusion 27a at the tip end as shown in FIG. 8 is interposed in the recess 26d on the inner periphery of the piston b. A pair of notches 4g, 4g 'and 4h, 4h'
And adjuster 26 is positioned and held in the rotational direction with respect to piston rod mounting member 4. Then, the adjuster 26 positions and holds the cam cylinder 24 in the rotation direction with respect to the stopper 23 fixed to the outer periphery of the cylinder 15.

An outer cover 30 attached to the outer periphery of the upper spring support 14 is provided outside the sub-spring 20 so as to hang down outside the intermediate spring support 22.
The outer cover 30 serves as a protective cover for covering the exposure of the sub-spring 20, and cooperates with the intermediate spring receiver 22 to control sliding parts such as the cylinder 15, the stopper 23, the cam cylinder 24, and the adjuster 26. It also serves to protect from earth and sand.

By the way, the spring constant of the sub-spring 20 is set to be larger than the spring constant of the main spring 21, and the spring constant of the sub-spring 20 is as shown in FIG.
As shown in the figure, the stopper 2 in a state where one occupant gets on the vehicle and the vehicle is stationary (ie, in the 1G riding state)
3 is axially separated from the position S0 of the lock portion 24b and the connection portion 24c of the cam cylinder 24, and when the cam cylinder 24 is rotated in the direction of arrow A, the stopper 2
3 and a small gap S between the cam barrel 24,
It is set larger than the spring constant of the main spring 21.

That is, the spring constant of the sub-spring 20 is k
_1, the spring constant of main spring 21 and _{k 2, k 1}
> If set to be k _2, if the spring load P is applied to the hydraulic shock absorber 10, the deflection of the sub-spring 20 P
/ K _{1 and} the deflection of the main spring 21 is P / k ₂
Becomes Since P / k ₁ <P / k ₂ , sub spring 2
The flexure of 0 is smaller than the flexure of the main spring 21, and it becomes easy to set a slight gap S between the stopper 23 and the lock portion 24b and the connection portion 24c of the cam cylinder 24. The main spring 21 _will k 1 / _{k 2} times bend it.

With this setting, it is possible to switch from the position of the insertion portion 24a of the cam cylinder 24 when one person gets on the vehicle to the set position of the lock portion 24b when two people get on while riding.

The spring constant of the above-described hydraulic shock absorber 10 of the present invention is switched as follows. First, at the time of single-person riding, the cam tube 24 is set so that the insertion portion 24a is located coaxially with the stopper 23. When the hydraulic shock absorber 10 is compressed at this set position, the piston rod 3 enters the cylinder 1, and the stopper 23 fixed to the outer periphery of the cylinder 15 also enters the insertion portion 24 a of the cam cylinder 24. . As a result, both the sub-spring 20 and the main spring 21 are compressed, and a soft spring constant obtained by combining the spring constants of both springs is obtained. At this time, the engaging portion 26a of the adjuster 26 is also engaged with the engaging groove 24 of the cam cylinder 24.
Enter into d.

The stopper 23 is compressed from the most extended position in FIG. 2 to the position S1 shown by a two-dot chain line in FIG. The compression position S1 of the stopper 23 at this time is the ride 1
This is the position in the G state.

When the load is increased due to two passengers or luggage being loaded from the riding 1G state, the occupant rotates the operating member (not shown) provided near the driver's seat while the passenger is in the riding state. Then, when the adjuster 26 of the hydraulic shock absorber 10 is rotated, the cam cylinder 24 is rotated in the direction of arrow A in FIG.

At this time, the spring constants of the two springs are set such that the spring constant of the sub-spring 20 is larger than the spring constant of the main spring 21, and the position S1 of the stopper 23 at the time of riding 1G is changed to the lock portion 24b and the lock portion 24b. Since the connection portion 24c connecting the portion 24b and the insertion portion 24a is set so as to be spaced apart in the axial direction from the position S0, that is, to be shallow, the locking portion 24 of the cam cylinder 24 is set.
b and the connecting portion 24 c rotate without contacting the stopper 23, and the 1 G load is applied to the intermediate spring receiver 22 and the cam cylinder 24.
Through the stopper 23.

As described above, the spring characteristics of the sub-spring 20 and the main spring 21 are set such that the spring constant of the sub-spring 20 is greater than the spring constant of the main spring 21, and the gap S between the stopper 23 and the cam cylinder 24. When the cam cylinder 24 rotates, the cam cylinder 24 rotates without colliding with the stopper 23, and the lock portion 24b can be switched to the position of the stopper 23 in the riding state. Operation becomes possible.

Next, the lock portion 2 is positioned at the position of the stopper 23.
4b, the stopper 23 sinks from the position S1 of the ride 1G and comes into contact with the lock portion 24b to prevent the compression of the sub-spring 20, so that the cam cylinder 24, the intermediate spring Only the main spring 21 is compressed via the receiver 22, and a hard spring characteristic is obtained.

In the present embodiment, the sub-spring 20 is supported on the piston rod 3 side, and the main spring 21 is supported on the cylinder 1 side. The main spring 21 may be supported on the piston rod 3 side on the cylinder 1 side.

According to the present invention, the following operations are provided. By rotating the adjuster 26, the cam cylinder 24 engaged with the adjuster 26 rotates, and when the insertion portion 24a of the cam cylinder 24 is set to be coaxial with the stopper 23 of the cylinder 15, the sub-spring 20 When the lock portion 24b is set coaxially with the stopper, only the main spring 21 is compressed, and only the main spring 21 is hardened. It is possible to obtain various spring characteristics.

Since the adjuster 26 that rotates the cam cylinder 24 does not move in the vertical direction, a remote operation member such as a wire cable 27, an operating rod, and an electromagnetically driven plunger can be easily attached to the adjuster 26.

Since the cam cylinder 24 is provided so as to be axially immovable and relatively rotatable with respect to the intermediate spring receiver 22, when the adjuster 26 is rotated, the cam cylinder 24 reciprocates. At this time, since the intermediate spring receiver 22 does not rotate, no load is applied to both springs 20 and 21 and a large operation force is not required.

The adjuster 26 can be rotated from the outside of the upper spring receiver 14 supporting the sub-spring 20 in the axial direction, so that remote control is possible. At this time, the spring load of both springs is applied to the upper spring receiver 14 supporting the sub-spring 20 and does not apply to the adjuster 26, so that the adjuster 26 can be easily rotated.

The position S of the stopper 23 due to the deflection of the main spring 21 and the sub-spring 20 at the time of riding 1G
1, the spring constant of the sub-spring 20 is set to be larger than the spring constant of the main spring 21 so as to be separated from the position S0 of the lock portion 24b and the connection portion 24c of the cam cylinder 24 in the axial direction. Even if the spring constant is switched from a soft spring constant for a single rider to a hard spring constant for a double rider or when the load is increased, the connection portion 2
4 c or the lock portion 24 b does not contact the stopper 23. Therefore, when the adjuster 26 is turned, a turning operation force for overcoming the 1G load of the ride is not required, so that the remote operation can be performed by the wire cable 27 or the like.
There is no need for the occupant to get out of the vehicle and return the hydraulic shock absorber 10 to the state at the time of maximum extension to switch the spring constant.

By rotating the adjuster 26 by remote control, the spring constant can be switched while the vehicle is in the riding state.

A detent mechanism 29 is provided between the adjuster 26 and the piston rod mounting member 4 or the cylinder 1.
Is provided, the cam barrel 24 engaged with the adjuster 26 is positioned and held at the switching position between the insertion portion 24a and the lock portion 24b.

Since the cylindrical body 15 fixed to the piston rod 3 also functions as a dust cover, the piston rod 3 can be protected from earth and sand.

[0046]

As described above, according to the hydraulic shock absorber 10 according to the present invention, since the adjuster 26 for rotating the cam cylinder 24 does not move in the vertical direction, the wire cable 27 is It becomes easy to mount and turn a remote control member such as a rod or an electromagnetically driven plunger.

Even if the spring constant is changed from a soft spring constant for one person to a hard spring constant for two persons or when the load is increased in the riding state, the rider 1
Since no G load is applied, a remote rotation operation can be performed.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a hydraulic shock absorber according to the present invention, showing a most extended state when a stopper is set in an insertion portion of a cam cylinder.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a side view showing a part of FIG.

FIG. 4 is a top view of FIG. 3;

FIG. 5 is a top view showing the upper spring receiver.

FIG. 6 is a front view showing a complete state in which an upper spring receiver, a cylindrical body, and a stopper are fixed.

FIG. 7 is a sectional view taken along line AA of FIG. 3;

FIG. 8 is an enlarged view showing a leaf spring of the detent mechanism of FIG. 7;

FIG. 9 is a front view showing a piston rod mounting member.

FIG. 10 is a bottom view of the piston rod mounting member of FIG. 9;

FIG. 11 is a top view of the adjuster.

FIG. 12 is a front view of an adjuster.

FIG. 13 is a development view of a cam cylinder.

[Explanation of symbols]

 Reference Signs List 1 cylinder 3 piston rod 14 spring receiver 14b supporting sub-spring 14b opening 15 cylindrical body 20 sub-spring 21 main spring 22 intermediate spring 23 stopper 24 cam cylinder 24a insertion section 24b lock section 24c connection section 24d engagement groove 26 adjuster 26a Joint

Claims (5)

[Claims] A main spring and a sub-spring are arranged in series between a cylinder and a piston rod that slides in the cylinder via a piston, with an intermediate spring receiver interposed therebetween. In a hydraulic shock absorber supported between a piston rod and a spring receiver, a stopper is fixed to a cylinder or an outer periphery of the cylinder non-rotatably attached to the piston rod, and an insertion portion through which the stopper can advance and retreat in the axial direction. A cam cylinder having a lock portion for preventing advance and retreat is provided so as to be axially immovable and relatively rotatable with respect to the intermediate spring receiver, and to be opened in a spring receiver for supporting the sub-spring on a piston rod or a cylinder; Part is formed in the circumferential direction, inserted through this opening, slidable with the cam cylinder, and
An adjuster having an engaging portion for rotating the cam cylinder is provided so as to be reciprocally rotatable with respect to the piston rod or the cylinder and immovable in the axial direction, and an insertion portion and a lock portion of the cam cylinder with respect to the stopper are provided. A hydraulic shock absorber for a vehicle, wherein the spring constant is changed by switching. 2. The position of the stopper due to the bending of the main spring and the sub-spring at the time of riding 1G is axially separated from the position of the lock portion and the connection portion connecting the lock portion and the insertion portion. The vehicle hydraulic shock absorber according to claim 1, wherein a spring constant of the sub-spring is set to be larger than a spring constant of the main spring. 3. The hydraulic shock absorber according to claim 1, wherein the adjuster is remotely rotated. 4. The hydraulic shock absorber according to claim 1, wherein a detent mechanism is provided between the adjuster and the piston rod mounting member or the cylinder. 5. The hydraulic shock absorber according to claim 1, wherein the cylindrical body non-rotatably attached to the piston rod is a dust cover.