JP2002081485A - Device for limiting mounting length of hydraulic shock absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically secure the effective engagement length of a screw joint portion using a mechanical locking means without visibly checking a marking of the effective engagement length of the screw joint portion between an outer shell and an extension bracket in a hydraulic shock absorber. SOLUTION: The extension bracket 6 having a mounting adjustment length for the hydraulic shock absorber 1 on the bottom side is threadedly inserted into a base end outer periphery portion of the outer shell 2 with a male screw 5 engraved in the outer periphery face, through a female screw 14, and a recessed groove 13 with a locking step portion 12 at one end is formed on the outer periphery portion of the outer shell 2 toward the circumference. A holder 16 adaptable to the recessed groove 13 with the rotation relative to the outer shell 2 is inserted into the extension bracket 6. A locking ball 17 is inserted to be set in and out of the holder 16 with a spring 18 and the locking ball 17 is received by the locking step portion 12 of the recessed groove 13 on the side of the outer shell 2. Therefore, the mounting length of the hydraulic shock absorber 1 can be adjusted while restricting the effective engagement length of the male screw 5 of the outer shell 2 and the female screw 14 of the extension bracket 6 is restricted not to exceed the design strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for mounting a hydraulic shock absorber on a predetermined portion of a vehicle or other devices.
A hydraulic shock absorber that can be mounted while being adjusted while adjusting the mounting length of the hydraulic shock absorber over a predetermined range in accordance with the length of the mounting portion of the vehicle or another device (hereinafter simply referred to as a vehicle or the like). The present invention relates to a device for restricting the length of mounting.

[0002]

2. Description of the Related Art Conventionally, as a mounting length adjusting device for a hydraulic shock absorber of this type, a reference mark is provided on an outer peripheral surface of an outer shell forming an outer portion of the hydraulic shock absorber, and an extension bracket is screwed from one end. The outer shell and the extension bracket are relatively rotated with respect to each other using the mark as a guide to restrict the mounting length of the hydraulic shock absorber from becoming too long. The bonding strength is ensured by keeping the values below.

Further, in this case, as a mark to be provided on the outer peripheral surface of the outer shell, a dent is formed on the outer peripheral surface of the male screw portion of the outer shell and paint such as red is applied. Print the color line to be used as a mark on the part, or scrape a part of the male screw and paint the part with red, etc., and use these points and lines as a mark to mark the effective length of the screw joint Is prevented from becoming shorter than the design target value, thereby preventing insufficient strength of the joint.

[0004]

However, according to the above-mentioned mark formed by forming a depression on the outer peripheral surface of the thread portion of the outer shell and applying a paint such as red, the strength of the thread portion for coupling is extremely small. Although it can be applied only by lowering it, it is difficult to confirm the mark because it is difficult to visually confirm.In addition, when a color surrounding the predetermined part of the male screw is printed with the color of the mark, the printed part is peeled. It may be difficult to see or disappear in some cases, and may not be able to serve as a landmark.

[0005] In this regard, in the case where a part of the male screw is cut off and a paint such as red as a mark is applied to the part, the paint does not peel off because the mark does not contact the female screw of the extension bracket. On the other hand, if a part of the male screw is cut off, the male screw on the outer shell side is cut at this part to be discontinuous.

Therefore, there is a possibility that the thread portion serving as the discontinuous end may be deformed and may not be properly engaged with the female screw of the extension bracket. In order to prevent this, the thread of the portion is not deformed. The necessity of performing such a special and troublesome chamfering work arises, and the production is troublesome and the cost is high.

Accordingly, an object of the present invention is to provide a method for automatically connecting a screw coupling portion using mechanical locking means without visually recognizing the effective length of engagement of the screw coupling portion using a passive means such as a mark. It is an object of the present invention to provide a hydraulic shock absorber mounting length limiting device capable of maintaining the engagement effective length of the hydraulic shock absorber at a design strength.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an extension having a hydraulic shock absorber mounting adjustment length on the bottom side through a female screw through the outer periphery of a base end of an outer shell having an outer thread engraved on the outer periphery. A bracket is screwed in, and a concave groove having a locking step at one end is formed in the outer peripheral portion of the outer shell in the circumferential direction, and the concave groove is formed with the relative rotation of the extension bracket with the outer shell. A matching holder is inserted and provided, and a locking ball is inserted into the holder so as to be able to protrude and retract with a spring, and the locking ball is received by a locking step of the concave groove on the outer shell side, so that a male screw of the outer shell can be formed. This is achieved by adjusting the mounting length of the hydraulic shock absorber while restricting the effective length of the extension bracket that engages with the internal thread to be less than the design strength. That.

That is, by forming the hydraulic shock absorber as described above, the locking ball rolls the surface of the outer thread of the outer shell with a spring with the relative rotation of the outer shell and the extension bracket. The inner bottom surface of the extension bracket is brought into contact with the outer surface of the bottom portion of the outer shell through the engagement with the outer shell, and the mounting length as the hydraulic shock absorber is adjusted to the shortest state.

On the other hand, when the outer shell and the extension bracket are relatively rotated in the opposite direction and are extracted, the locking ball provided on the extension bracket side at a predetermined relative position fits into the recess groove on the outer shell side. As a result, the locking step is brought into contact with the locking step, and the locking step of the recessed groove receives further movement of the locking ball.

In this way, the outer shell and the extension bracket are integrated by the contact between the locking step and the locking ball, and further relative rotation is mechanically stopped. Not only is adjusted and held to the longest state, but also from this state, if the outer shell and the extension bracket are further rotated to push the locking ball into the holder, the height of the locking step is reduced. If the radius is greater than the radius of the stop ball, no pushing force is applied to the locking ball.

Therefore, the outer shell and the extension bracket are integrated in the rotation direction and the relative rotation is prevented, so that the extension bracket is securely prevented from coming out of the outer shell.

If the relative rotation of the outer shell and the extension bracket is stopped when the mounting length of the hydraulic shock absorber reaches an arbitrary length between the shortest state and the longest state,
The hydraulic shock absorber can be adjusted to any intermediate length while maintaining the mounting length at that time.

Thus, from the shortest state of the hydraulic shock absorber, in which the internal thread of the extension bracket is screwed to the external thread of the outer shell over the entire length, the longest mounting length in which the internal thread of the extension bracket is fully retracted from the external thread of the outer shell. Within the adjustment range, while maintaining the effective length of engagement between the external thread of the outer shell and the internal thread of the extension bracket at the design target value, the coupling strength of the screw portion is reduced below the design target value, and the engagement portion is damaged. It will prevent you.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description of an embodiment of the present invention with reference to the accompanying drawings, a case where the present invention is applied to an upright type hydraulic shock absorber is shown as an example. Needless to say, the present invention can be applied to an inverted hydraulic shock absorber which is conventionally known.

FIG. 1 is an external view showing a hydraulic shock absorber 1 provided with a mounting length adjusting device according to the present invention as viewed from the front, and an outer shell 2 constituting a main body of the hydraulic shock absorber 1 includes: A piston rod 4 having an upper mounting bracket 3 integrally attached to a protruding end thereof upwardly extends and extends.

A male screw 5 is engraved on the outer peripheral surface of the outer shell 2 while leaving both end portions slightly, and an extension bracket 6 is provided to the outer peripheral portion of one end of the outer shell 2 through the male screw 5. Brackets 7 for spring receiving are screwed into the upper part, respectively, and these extension brackets 6 and brackets 7 for spring receiving are firmly fixed by tightening with lock nuts 8, 9 screwed into the male screw 5, respectively. I have to get it.

At the lower end of the extension bracket 6, a lower mounting bracket 10 is fixedly provided in correspondence with the upper mounting bracket 3, and a suspension is provided between the upper mounting bracket 3 and the bracket 7 for spring receiving. A spring 11 is interposed, and the vehicle body is supported by the upper and lower mounting brackets 3 and 10 on the wheels through the suspension spring 11.

FIG. 2 and FIG. 3 are a longitudinal sectional front view and a cross-sectional plan view showing, on an enlarged scale, a portion where the outer shell 2 and the extension bracket 6 are attached. As can be seen from FIG. On the outer peripheral surface of the outer shell 2, a male screw 5
Is partially cut away in the radial direction to form a recessed groove 13 having one end as a locking stepped portion 12.

The extension bracket 6 is provided with a female screw 15 except for a play portion 14 having a width corresponding to the mounting adjustment length of the hydraulic shock absorber on the bottom side, and the female screw 15 is screwed into the male screw 5 of the outer shell 2 from below. With the relative rotation of the outer shell 2 and the extension bracket 6, the extension bracket 6 is fitted to the outer periphery of the lower portion of the outer shell 2 so as to be able to freely move in and out in the axial direction.

On the side surface of the extension bracket 6, a holder 16 that matches with the concave groove 13 of the outer shell 2 is provided so as to be inserted with the relative rotation with respect to the outer shell 2. Is inserted freely
The locking ball 17 is pressed against the surface of the male screw 5 in the outer shell 2 by the restoring force of the spring 18 housed inside the holder 16.

When the outer shell 2 and the extension bracket 6 rotate relative to the extension side, the locking ball 17
The outer bracket 2 moves while rolling on the surface of the male screw 5 and is finally stopped by hitting the locking step 12 of the concave groove 13 formed on the surface of the male screw 5. In this state, the extension bracket 6 comes out of the outer shell 2 and falls off. This is to prevent it.

Thus, according to the present embodiment, the locking ball 17 rolls over the surface of the external thread 5 of the outer shell 2 with the spring 18 and extends with the external thread 5 with the relative rotation of the outer shell 2 and the extension bracket 6. The inner bottom surface of the extension bracket 6 is brought into contact with the bottom outer surface of the outer shell 2 through meshing with the female screw 15 in the bracket 6, and the mounting length as the hydraulic shock absorber 1 is adjusted to the shortest state.

On the other hand, when the outer shell 2 and the extension bracket 6 are pulled out by being rotated in the opposite directions relative to each other, the locking ball 17 provided on the extension bracket 6 at a predetermined relative position is recessed on the outer shell 2 side. The engaging step 1 fits into the groove 13 and abuts on the engaging step 12, and the engaging step 1
2 stops the further movement of the locking ball 17.

Thus, the outer shell 2 and the extension bracket 6 are integrated by the contact between the locking step portion 12 and the locking ball 17, and further relative rotation is mechanically stopped. Not only is the mounting length adjusted to the longest state, and the outer shell 2 and the extension bracket 6 are further rotated relative to this state to push the locking ball 17 into the holder 16. If the height of the locking step 12 is set to be equal to or larger than the radius of the locking ball 17, no pushing force is applied to the locking ball 17.

Therefore, the outer shell 2 and the extension bracket 6 are integrated in the rotation direction to prevent relative rotation,
As a result, it is possible to reliably prevent the extension bracket 6 from slipping out of the outer shell 2.

When the mounting length of the hydraulic shock absorber 1 reaches an arbitrary length between the shortest state and the longest state,
If the relative rotation between the outer shell 2 and the extension bracket 6 is stopped, the hydraulic shock absorber 1 can be adjusted to an arbitrary intermediate length while maintaining the mounting length at that time.

Thus, the female screw 15 of the extension bracket 6
From the shortest state of the hydraulic shock absorber 1 which is screwed to the external thread 5 of the outer shell 2 over the entire length, and the mounting length adjustment in the longest state in which the internal thread 15 of the extension bracket 6 is completely retreated from the external thread 5 of the outer shell 2. Within this range, while maintaining the effective length of engagement between the external thread 5 of the outer shell 2 and the internal thread 15 of the extension bracket 6 at the design target value, the coupling strength of the screw portion is reduced below the design target value, and the engagement portion is broken. It will prevent it from happening.

In the above-described embodiment of the present invention, the case where the mounting length limiting device of the hydraulic shock absorber 1 by mechanical means is used alone has been described. It is a matter of course that the mounting length limiting device of the hydraulic shock absorber 1 according to the above may be used in combination with a conventional device which is visually recognized using a mark as a guide.

[0030]

As described above, according to the first aspect of the present invention, the mounting adjustment length of the hydraulic shock absorber is set to the bottom side by passing the female screw through the base outer peripheral portion of the outer shell having the external thread engraved on the outer peripheral surface. The extension bracket provided is screwed in, and a recessed groove having a locking step at one end is formed in the outer peripheral portion of the outer shell in the circumferential direction, and with the relative rotation of the extension bracket to the outer shell. A holder matching the recessed groove is inserted through the holder, a locking ball is inserted into the holder so as to be able to protrude and retract with a spring, and the locking ball is received by a locking step of the recessed groove on the outer shell side. The length of the hydraulic shock absorber can be adjusted while controlling the effective length of engagement between the male screw of the extension bracket and the female screw of the extension bracket so as not to be less than the design strength. Irrespective of the relative rotation of the shell and the extension bracket, the effective length of engagement at the threaded joint between the two is always maintained at the design target value without reducing the strength of the threaded joint, and the extension bracket from the outer shell This makes it possible to adjust the mounting length of the hydraulic shock absorber in accordance with the length of the mounting portion on the vehicle side while preventing the escape.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of a hydraulic shock absorber provided with a device for adjusting a mounting length to a vehicle body according to the present invention.

FIG. 2 is an enlarged longitudinal sectional front view showing only an attachment portion of an extension bracket in the above.

FIG. 3 is an enlarged cross-sectional plan view showing a joint portion between an outer shell and an extension bracket.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic shock absorber 2 Outer shell 4 Piston rod 5 Male screw 6 Extension bracket 11 Suspension spring 12 Locking step 13 Depression groove 14 Play part 15 Female screw 16 Holder 17 Locking ball 18 Spring

Claims (1)

[Claims] 1. An extension bracket provided with a hydraulic shock absorber mounting adjustment length is screwed into the bottom side through a female screw into a base end outer peripheral portion of an outer shell in which a male screw is engraved on an outer peripheral surface, and is inserted into an outer peripheral portion of the outer shell. A recessed groove having a locking step at one end is formed in the circumferential direction, and a holder matching the recessed groove is provided through the extension bracket with the relative rotation with the outer shell. The locking ball is inserted inside the spring so that it can freely move in and out, and the locking ball is received by the locking step of the recess groove on the outer shell side, so that the effective length of engagement between the external thread of the outer shell and the internal thread of the extension bracket is designed. A mounting length limiting device for a hydraulic shock absorber, wherein the mounting length of the hydraulic shock absorber can be adjusted while regulating the strength of the hydraulic shock absorber so as not to be less than the strength.