JPH0488229A - Variable rigid bush device - Google Patents

Abstract

PURPOSE:To improve workability and reduce production cost by forming at least one relief groove for each of the edge surfaces in contact with the stepped parts of a cylindrical body and the stepped parts of a body member, among the edge surfaces of a piston. CONSTITUTION:In order to suppress the back pressures of pistons 36A and 36B by reducing the contact area between the stepped part 21B of a cylindrical body 20 and the stepped parts 31B and 31D of a body member 30, at least one relief groove 36A, 36B is formed on the pistons 36A and 36B, for the edge surfaces in contact with the stepped part 21B of the cylindrical body 20 and the stepped parts 31B and 31D of the body member 30. Besides, in order to facilitate assembly work, at least one relief groove 36a'', 36b'' is formed for each of the edge surface which is not in contact with the stepped part 21B of the cylindrical body 20 and the stepped parts 31B and 31D of the body member 30. An arrangement groove 38A is formed on the inner peripheral surface of a stop nut 37, and a packing member 38 is arranged. An arrangement groove 39A is formed on the outer peripheral surface of the stop nut 37, and an O-ring 39 is arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the invention [Field of industrial application] The present invention relates to a variable stiffness bushing device, and more particularly, to a bushing device with variable stiffness. Contact between the piston and the step of the cylinder or the step of the body member by forming at least one protrusion on each of the end surfaces that abuts the step of the cylinder and the step of the body member. This invention relates to a variable rigidity bushing device that reduces area and suppresses back pressure on a piston.

[Prior Art] Conventionally, this type of variable-rigidity bushing device, such as the variable-rigidity bushing device 10 shown in FIG. of the pistons 36A and 36B with respect to the stepped portion 21B of the cylindrical body 20 and the stepped portion 31B of the body member 4 and the end face of the stop nut 37 (hereinafter referred to as “stepped portion 31D of the body 4 member 3o”). When controlling the relative movement between the cylinder body and the body member recess by adjusting the rigidity between the cylinder body and the body member recess by pressing and bringing the end faces into contact with each other with pressurized fluid, the cylinder At least one advance 43A for each of the stepped portion 21B of the body member 30, the stepped portion 31B of the body member 30, and the end face of the distal end of the stop nut 37, that is, the stepped portion 31D of the body member 30,
43B44 has been proposed to suppress the back pressure of the pistons 36A and 36B and to facilitate the relative movement of the cylinder 20 and the body member 30 in the return direction.

[Problems to be solved] However, in the conventional variable stiffness bushing device IO,
A stepped portion 21B of the cylinder body and a stepped portion 31B of the fourth body member,
310, there were the following drawbacks: (i) Difficult work was required to form the threads, and (11) poor workability and the inability to reduce manufacturing costs. there were.

Therefore, in order to eliminate these drawbacks, the present invention provides a piston by forming at least one protrusion on each of the end faces of the piston that abuts the stepped portion of the cylinder body and the stepped portion of the body member. It is an object of the present invention to provide a variable rigidity bushing device which reduces the contact area between the step part of the cylinder body or the step part of the body member and suppresses the back pressure of the piston.

(2) Structure of the Invention [Means for Solving the Problems] The means for solving the problems provided by the present invention is as follows. , the piston is brought into contact with the stepped portion of the body member and the stepped portion of the cylindrical body using pressurized fluid to suppress relative movement between the cylindrical body and the body member. In the production of variable rigidity bushings with varying rigidity, pistons "f36A, 36B"
) of the cylinder body (20) and the step portions f31B and 31Dl of the body member (concave), at least one advance (36a
36b) is a variable rigidity bushing device J.

[Operation 1] As specified in the above section [Means for solving problems], the variable rigidity bushing device according to the present invention has a cylindrical body arranged so as to be movable relative to the through hole of the body member via the bushing. Then, the piston is brought into contact with the stepped portion of the body member and the stepped portion of the cylindrical body using pressurized fluid to suppress relative movement between the cylindrical body and the body member. A variable-rigidity bushing device that changes the rigidity between the bushings, and in particular forms at least one extension on each of the end faces of the piston that abuts the stepped portion of the cylinder body and the stepped portion of the body member. (ii) It serves to reduce the contact area between the piston and the stepped part of the cylinder or the stepped part of the body member, and facilitates the creation of a countermeasure for suppressing the back pressure of the piston. ii) It serves to improve workability and reduce manufacturing costs.

[Example] Next, regarding the variable rigidity bushing device according to the present invention,
A preferred embodiment thereof will be described in detail with reference to the accompanying drawings.

However, the examples described below are described to facilitate or promote understanding of the present invention, and are not described to limit the present invention.

In other words, each element disclosed in the embodiments described below includes all design changes and equivalent substitutions that fall within the spirit and technical scope of the present invention.

The first section is a cross-sectional view taken along the line I-I to show an embodiment of the variable rigidity bushing device according to the present invention, and shows the cylindrical body drop and body member opening. The relative movement with the piston 36A,
36B.

FIG. 2 is a cross-sectional view of the embodiment shown in FIG. 1 taken along the line ■-■.

FIG. 3 is a perspective view of a portion of the embodiment shown in FIG. 1, showing pistons 36A and 36B.

FIG. 4 (bl) is a sectional view showing the operating state of the embodiment shown in FIG. ing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the structure of an embodiment of a variable rigidity bushing device according to the present invention will be described in detail with reference to FIGS. 1 to 4 fa) and (b).

(2) is a variable rigidity bushing device according to the present invention,
A cylindrical body (also referred to as a cylinder) for inserting and connecting a rod (not shown) that can be moved or expanded in the axial direction, and a cylindrical body that can be inserted so as to be movable in the axial direction. A body member 4 is provided with a through hole 30A formed therein.

The outer circumferential surface of the central portion of the cylinder 20 is expanded, and a stepped portion 21A is formed at one end of the expanded portion, and a stepped portion 21B is formed at the other end. Further, in order to stop excessive relative movement between the body members υt, a stopper 22 is disposed on the outer circumferential surface of the other end of the cylinder (2).

The stopper 22 is fixed by a C ring 23 disposed in a groove 23A formed on the outer circumferential surface of the other end of the cylindrical body 20.

A damper 24 is further arranged on the stopper 22 to alleviate collisions between the body members 30e.

A groove 25A is formed on the outer peripheral surface of the cylinder at an intermediate position between the stepped portion 21B and the groove 23A.
5 are arranged.

The body member recessed through hole 30A is reduced at the center, and a stepped portion 31A is formed at one end of the reduced portion, and a stepped portion 31B is formed at the other end. Stepped portion 31A
, the distance i between 31B! (that is, the width of the reduced portion of the through hole 30A) is the distance between the stepped portions 21A and 21B, which are similar to the cylinder body (
In other words, it is made to match the width of the expanded part of the cylindrical body. The through hole 30A of the body member 30 further has a stepped portion 31B.
It is expanded on the other end side, and a stepped portion 31C is formed.

The inner peripheral surface of one end of the through hole 30A of the body member 30 and the cylindrical body 2
A laminated body of an inner sleeve 32, a bushing 33 having appropriate characteristics (for example, spring characteristics), and an outer sleeve 34 is press-fitted between the outer circumferential surface of one end of the inner sleeve 32 and the outer peripheral surface of the outer sleeve 34. The inner sleeve 32 has a stepped portion 21A of the cylindrical body 20 at one end.
The other end is curved outward at one end of the cylindrical body 20 and then extended to the end surface of the body member 30 . The bush 33 is disposed extending along the surface of the inner sleeve 22 to the other end, and also functions as a damper to alleviate collisions between the body member court and the outer sleeve 34 and the inner sleeve 32. ing. The outer sleeve 34 has one end disposed near the stepped portion 31A of the body member 30 and the other end thereof a bush 3 disposed at the other end of the inner sleeve 32.
It is opposed to and spaced apart from the extension of No. 3.

A groove 35A is formed on the inner peripheral surface of the through hole 30A of the body member 30 between the stepped portions 31A and 31B, and a backing member 35 is disposed therein. Also,
The space formed between the stepped portions 31B and 31G of the body member 30 and the outer peripheral surface of the cylinder 20 is
Two pistons 36A and 36B are disposed which are movable along the axial direction of the piston and whose opposing end surfaces are spaced apart from each other. The piston 36A has a stepped portion 21B on the opposite end surface in order to suppress relative movement between the cylindrical body 20 and the body member 30.
, 31B.

In order to suppress relative movement between the cylindrical body 20 and the body member 30, the piston 36B is provided with the body member 30 on the opposite end surface.
The end surface of the tip end of the stop nut 37 (hereinafter referred to as "body member 3
The pistons 36A and 36B are able to come into contact with the step 31D of the cylinder 20 and the body member 20, and are prevented from moving excessively by the stop ring 25. 30 and the step portions 31B and 310 of the body member 30 to reduce the contact area with the step portions 31B and 310 of the body member 30 and suppress the back pressure of the pistons 36A and 36B. end face (”
At least one protrusion 36a, 36b is formed on the outer end surface (also referred to as "outer end surface 1"), and a stepped portion 21B of the cylinder 20 or a stepped portion 31B of the body member 30 is formed for the purpose of facilitating assembly work.

End face that does not come into contact with 310 (also referred to as °°inner end face °°)
at least one course for each 3681, 36
b" is formed on the inner peripheral surface of the stop nut 37.
An arrangement groove 38A is formed in which the backing member 38 is arranged. An arrangement groove 39A is formed on the outer peripheral surface of the stop nut 37, and an O-ring 39 is arranged therein. Here, backing members 35, 38 and O-rings 39 are arranged to seal pressurized fluid supplied to pistons 36A, 36B.

Pistons 36A and 36B are provided on the outer peripheral surface of the body member.
A fluid supply boat 41 is formed for supplying pressurized fluid between the opposing end surfaces of the pistons 36A and 36B via the guide passage 41A, and the opposite end surfaces of the pistons 36A and 36B (i.e., the stepped portion 31
A fluid recovery boat 42 is formed for recovering pressurized fluid from the guide passages 42A, 42B from the guide passages 42A, 42B.

If desired, an outer circumferential groove 45 is formed on the outer circumferential surface of the cylindrical body so as to communicate with the protrusion 36a. Inner circumferential grooves 46 and 47 are formed on the inner circumferential surface of the through hole 30A of the body member 4, respectively.
It is formed so that it communicates with the

Another through hole 30B is formed in the body member recess in a direction perpendicular to the axial direction of the cylindrical body (in this case, perpendicular direction), and an outer sleeve 51 and an appropriate characteristic ( For example, a laminate of a bush 52 having spring characteristics and an inner sleeve 53 is press-fitted. The inner sleeve 53 has a threaded portion 53a formed on its inner peripheral surface, and is screwed into a suitable mating member (for example, the body of an automobile; not shown).

Yu! Furthermore, with reference to FIGS. 1 to 4, the operation of an embodiment of the variable stiffness bushing device according to the present invention will be described in detail.

When pressurized fluid is not supplied from the fluid supply boat 41 through the guide passage 41A, the piston 36A36B
Step portion 21B of cylinder body 20 and step portion 31 of body member 30
B. Do not press 31D. Therefore, the cylinder 20 is
It is movable relative to the body member (see Section 1 to Figure 4 (b)).

Therefore, the variable stiffness bushing device 10 according to the present invention operates with stiffness depending on the characteristics of the bushing 33,52.

A place where pressurized flow is provided from the fluid supply boat 41 to the arrow EI through the guide passage 41A.
] When pressurized fluid is supplied as shown by X, the pistons 36A and 36B are respectively
1B and the stepped portion 31B of the body member court and the stop ring 25
and the stepped portion 31D (that is, the end surface of the distal end of the stop nut 37) located off the body member, in accordance with the pressure of the pressurized fluid (see FIGS. 1 and 2).

Therefore, when the relative movement force between the cylinder body and the body member is smaller than the pressing force generated by the pressurized fluid, the pistons 36A and 36B move the cylinder body 20 and the body member 30. Since relative movement is stopped,
The variable stiffness bushing device 10 according to the present invention operates with stiffness depending on the characteristics of the bushing 52 (see FIGS. 1 and 2).

On the other hand, when the relative movement force between the cylinder 20 and the body member 30 becomes larger than the pressing force generated by the pressurized fluid, the cylinder 20 becomes movable relative to the body member 30. The variable rigidity bushing device (2) according to the invention operates with the stiffness depending on the characteristics of the bushing 33.52 [Fig. 4 (a) (b)? (see).

Incidentally, the pressurized fluid supplied between the opposing surfaces of the pistons 36A, 36B passes through the circumferential surfaces of the pistons 36A, 36B and reaches the opposite surface, and then flows through the pistons 36a, 36b, the inner circumferential groove 45, the outer circumferential groove 46. 47 to the guide passages 42A, 42B and the fluid recovery boat 42
It is recovered as shown by arrow Y (see Figure 1).

(3) Effects of the Invention As is clear from the above description, the variable rigidity bushing device according to the present invention provides a variable rigidity bushing device that is capable of attaching the bushing to the through hole of the body member, as specified in the above-mentioned [Means for solving problems] column. The cylindrical body is arranged to be movable relative to each other, and the piston is brought into contact with the stepped portion of the body member and the stepped portion of the cylindrical body using pressurized fluid to suppress relative movement between the cylindrical body and the body member. A variable-rigidity bushing device in which the rigidity between a body member and a cylinder is changed by changing the rigidity between the body member and the cylinder, and in particular, among the end faces of the piston, the end face that comes into contact with the stepped part of the cylinder and the stepped part of the body member Since at least one step is formed for each, fil creation of a relief groove to reduce the contact area between the piston and the step of the cylinder or the step of the body member and suppress the back pressure of the piston. This has the effect of making it easier to perform the process, and in turn has the effect of (11) improving workability and reducing manufacturing costs.

[Brief explanation of drawings]

FIG. 1 is a sectional view taken along I-I iff to show one embodiment of the variable stiffness bushing device according to the present invention;
The figure is a sectional view taken along the line ■-■ of the embodiment in FIG. Fig. 1 is a sectional view showing the operating state of the embodiment, and Fig. 5 is a sectional view showing the conventional example. 20... 21A, 21B 22... 23・ ・ ・ ・ ・ ・ 23A ・ ・ ・ ・ 24 ・ ・ ・ 25 ・ ・ 5A ・Variable rigidity bushing device・Cylinder step stopper C Ring, arrangement groove, damper, stop ring, arrangement groove, body member 30A 30
B...Through holes 31A, ~, 31D...
...Stepped portion 32 ...Inner sleeve 33 ...Button 34 ...
......Outer sleeve 35...
...Backing member 35A...
・・Arrangement groove 36A・・・・・・・・・・・Piston 36a,
36a”・・・・・・Advancement 36B・・・・・・・・・
...Piston 36b, 36b''...
・Escape groove 37・・・・・・・・・・・・Stop nut 3
8・・・・・・・・・・・・・・・Backing member 3
8A...... Installation groove 39... O-ring 39A.
......Distribution groove 41...Fluid supply boat 41
A......Guidance passage 42...
・・・・・・Fluid recovery boat patent

Claims (1)

[Claims] The cylindrical body is disposed so as to be movable relative to the through hole of the body member via a bush, and the piston is brought into contact with pressurized fluid against the stepped portion of the body member and the stepped portion of the cylindrical body. In a variable rigidity bushing device that changes the rigidity between a body member and a cylindrical body by suppressing relative movement between the pistons (36A, 36
Step part (21B) of the cylinder (¥20) and step part (31B, 31D) of the body member (¥30) among the end faces of B)
A variable rigidity bushing device characterized in that at least one relief groove (36a, 36b) is formed in each end face that comes into contact with the bushing device.