JPH0610983A - Shock absorber - Google Patents

Abstract

PURPOSE:To improve the versatility by providing a shock absorber preventing an electric shock and an electric leakage, advantageous in control and safety, and realizing the preset damping function. CONSTITUTION:A piston side chamber B is communicated with a rod side chamber A via the extension side check valve 3a of a piston section 3, and a control gap S communicated with a rod side chamber A and a reservoir chamber is formed between a cylinder 1 and an inner tube 10, the reservoir chamber is communicated with the piston side chamber B via a pressure side check valve 14c of a base valve section 14 arranged at the lower end section of the cylinder 1, and both end sections of the cylinder 1 and the inner tube 10 are connected to a bearing and the valve body of the base valve 14 in a shock absorber. The upper end or the lower end of the cylinder 1 or the inner tube 10 is coupled with the bearing or the valve body via an elastic material 30.

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, or a shock absorber capable of adjusting a generated damping force by utilizing a property that an electrorheological fluid changes its viscosity according to an applied voltage.

[0002]

2. Description of the Related Art In recent years, for example, a hydraulic shock absorber used as a shock absorber for an automobile is constructed so that the generated damping force is adjusted according to the condition of the road surface of the automobile. Is desired.

Therefore, in the hydraulic shock absorbers conventionally proposed for that purpose, in general, when the piston portion slides in the cylinder by retracting the piston rod with respect to the cylinder, A predetermined damping force is generated by the hydraulic fluid passing through the damping force generation unit, and the mechanism of the damping force generation in the damping force generation unit is mechanically changed or passes through the damping force generation unit. It is configured to increase or decrease the generated damping force by increasing or decreasing the flow rate of the hydraulic oil.

As a result, when the damping force generating section is constituted by a damping characteristic such as a throttle or a valve, the damping force generated within the characteristic damping range is adjusted. Therefore, when the hydraulic shock absorber equipped with this damping force generating unit is mounted on an automobile, the initial purpose of adjusting the generated damping force according to the condition of the road surface on which the automobile is traveling. There is a danger that the

If the damping force generating portion is constructed to have various throttles, valves, etc. so as to be able to exert damping force of various characteristics, the structure of the hydraulic shock absorber becomes complicated and its productivity is increased. Not only will the inconvenience be lowered and maintenance will be troublesome, but also the control will be complicated in response to the complicated structure, and expensive parts will be used a lot. As a result, inconveniences such as an increase in production cost are likely to occur.

Therefore, in recent years, an electrorheological fluid having a property that its viscosity changes with an applied voltage has been discovered, and for example, it is shown in FIG. 2 disclosed in Japanese Utility Model Publication No. 3-5698. A shock absorber using an electrorheological fluid having such a structure has been proposed.

That is, the shock absorber is formed in the form of a conventional hydraulic shock absorber, and the tip of the piston rod 2 which is inserted into and retracted from the cylinder 1 slides inside the cylinder 1. It has a piston portion 3 which moves and which partitions and forms a rod side chamber A and a piston side chamber B in the cylinder 1.

The rod-side chamber A and the piston-side chamber B are filled with an electrorheological fluid, and the rod-side chamber A and the piston-side chamber B are arranged in parallel with the extension-side check valve 3a provided in the piston portion 3. It is supposed that they are communicated with each other via the diaphragm 3b.

The cylinder 1 has a port 1a at the upper end and a port 1b at the lower end, and the side chambers A and B are communicated with the outside through the ports 1a and 1b, respectively. .

A reservoir tank T is disposed outside the cylinder 1, and a tank chamber T1 forming the reservoir tank T is provided with a reservoir chamber T2 and a gas chamber T therein.
3 and a compartment forming free piston T4 are slidably accommodated therein.

The chamber T2 is communicated with the piston side chamber B in the cylinder 1 through the pipe P.

On the other hand, it is assumed that a so-called outer cylinder is provided on the outer peripheral side of the cylinder 1 so as to form a chamber R. The outer cylinder is composed of the head side cylindrical body 4 and the bottom side cylindrical body. 5 and an intermediate tubular body 6.

The chamber R is communicated with the side chambers A and B through the ports 1a and 1b for opening the cylinder 1.

The head-side tubular body 4 has a bearing member 7 screwed onto the inner periphery of its upper end, and a piston rod 2 is slidably inserted in the center of the bearing member 7.

The head-side tubular body 4 has a flange portion 4a at its lower end, and is connected to the upper end of the intermediate tubular body 6 via the flange portion 4a.

The bottom side tubular body 5 is provided with a pressure side check valve 5a and a throttle 5b in parallel with the pressure side check valve 5a at the lower wall thickness portion thereof, and the pressure side check valve 5a and the throttle 5b are provided in the reservoir tank T. The chamber T2 is communicated with the piston side chamber B.

The bottom side tubular body 5 has a flange portion 5c at its upper end, and is connected to the lower end of the intermediate tubular body 6 via the flange portion 5c.

The intermediate tubular body 6 has flange portions 6a and 6b at its upper and lower ends, respectively.
a and 6b are connected to the flange portion 4a of the head-side tubular body 4 and the flange portion 5c of the bottom-side tubular body 5, which are opposed to each other, by bolts and nuts 9 via an insulating material 8.

The intermediate tubular body 6 has an interval of about 1 mm between the inner periphery thereof and the outer periphery of the cylinder 1 so that a part of the chamber R is so-called narrowed. The control gap S is supposed to be formed.

The control gap S functions to change the viscosity of the electrorheological fluid interposed in the electric field to a hardening tendency in accordance with the applied voltage amount when the electric field is developed therein.

Further, in this conventional example, the cylinder 1 is used as one electrode member, while the intermediate tubular body 6 is used as the other electrode member. The extended electric wire E1 has one electrode member, that is,
The electric wire E2 connected to the upper end side tubular body 4 electrically connected to the cylinder 1 and extended from the controller C is connected to the intermediate tubular body 6 serving as the other electrode member.

Therefore, according to the shock absorber using the electrorheological fluid as the conventional proposal, when the piston portion 3 slides in the cylinder 1 by retracting the piston rod 2 with respect to the cylinder 1, The electrorheological fluid will pass through the control gap S arranged outside the cylinder 1. At this time, a predetermined voltage is applied to both electrode members to develop an electric field in the control gap S. By doing so, the viscosity of the electrorheological fluid is changed to a hardening tendency according to the applied voltage amount in the electric field.

Therefore, on condition that the applied voltage is maintained, the flowability of the electrorheological fluid in the control gap S tends to be impeded thereafter, and as a result, the piston portion 3
Slidability in the cylinder 1 is hindered, that is, a damping action is exhibited, and by appropriately selecting the applied voltage amount to both electrode members, the degree of the damping action to be produced is arbitrary. Can be adjusted to.

If the shock absorber as the above-mentioned conventional proposal is mounted on an automobile, the degree of damping action can be adjusted according to the condition of the road surface on which the automobile travels. It can be improved to a preferable state.

On the other hand, the outer cylinder is concentrically arranged on the outer side of the cylinder, the outer shell is provided on the outer side of the outer cylinder, and the cylinder and the outer cylinder are fitted to the valve body of the bearing and the base valve. A multiple type hydraulic shock absorber in which a reservoir is defined between the shell and the shell is disclosed, for example, in Japanese Utility Model Publication No. 62-24846.

[0026]

However, in the conventional shock absorber utilizing electrorheological fluid disclosed in Japanese Utility Model Publication No. 3-5698, there is a defect in security and a predetermined damping action. There is a danger that you will not be able to expect it.

That is, the shock absorber according to the conventional example has the upper end side tubular body 4 and the lower end side tubular body 5 electrically connected to both electrode members, that is, the cylinder 1 which is one electrode member, and the other side. The intermediate tubular body 6 serving as an electrode member is exposed to the outer circumference of the shock absorber.

Therefore, both electrode members are in a so-called exposed state, and there is a risk of electric shock if the human body touches them.

Further, even when mounted on an automobile, there is a risk of current leakage due to contact of current with other parts through the bearing member 7 etc., resulting in power loss.

Further, in the case of the above-mentioned conventional example, since the flange portions 4a, 6a and 5c, 6b are formed outside the shock absorber, the chances of the electric shock and the electric leakage increase. There is inconvenience.

Further, in view of the fact that the control gap S is required to be maintained at about 1 mm, in the above-described conventional example, the intermediate tubular body 6 becomes uneven. Although it is absolutely necessary to avoid such a situation as described above, there is a risk that a dent may be formed due to a stone colliding with the outer periphery of the intermediate tubular body 6 while the shock absorber is mounted on an automobile, for example. If the depression is formed, the control gap S
There is a danger that the interval of will be out of order, and the expected damping effect cannot be expected.

The maintenance of the space in the control gap S is required even when the shock absorber is transported as a product, and there is a disadvantage that its management becomes troublesome.

On the other hand, in the conventional hydraulic shock absorber disclosed in Japanese Utility Model Publication No. 62-24846 mentioned above, it is difficult to obtain dimensional accuracy for mounting as desired because the cylinder and the outer cylinder have different lengths. If the expansion rate or the contraction rate of the cylinder and the outer cylinder differ due to the temperature change, one cylinder or the outer cylinder becomes loose and the installation is unstable, which may cause oil leakage.

The present invention was devised in view of the above-mentioned circumstances, and the purpose thereof is that there is no risk of electric shock or leakage, it is advantageous in management and security, and it has a predetermined attenuation. It is an object of the present invention to provide a shock absorber using an electrorheological fluid, which can realize the action as set and which can be expected to improve its versatility.

Furthermore, even if multiple pipes having different lengths are used, the assemblability is improved, the dimensional machining accuracy can be made rough, and a shock absorber that does not cause rattling in each of the multiple pipes even when the temperature changes. It is to be.

[0036]

In order to achieve the above-mentioned object, the structure of the present invention has an inner tube disposed outside the cylinder, an outer tube disposed outside the inner tube, and an inner tube and an outer tube. A reservoir chamber is formed between the tube and the piston part that is slidably accommodated in the cylinder to form a rod side chamber and a piston side chamber in the cylinder, while checking the extension side of the piston part. The piston side chamber is connected to the rod side chamber via a valve, and a control gap is formed between the cylinder and the inner tube so as to communicate with the rod side chamber and the reservoir chamber, and the reservoir chamber is arranged at the lower end of the cylinder. It is connected to the piston side chamber via the pressure side check valve in the installed base valve section, and both ends of the cylinder and the inner tube are connected. In shock absorber is coupled to the valve body of the bearings and the base valve, the upper end or lower end of the cylinder or the inner tube is characterized in that it is fitted in the bearing or the valve body via an elastic member.

[0037]

[Effect] Even if the length of the cylinder or the inner tube is different, the elastic member can absorb the nonuniformity of the length, and even if the cylinder and the inner tube are distorted or the dimensions change due to the temperature change, the elastic member. Absorbs this.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail based on the illustrated embodiments. The embodiment shown in FIG. 1 is a shock absorber using an electrorheological fluid for automobiles. It has a cylinder 1, an inner tube 10, and an outer tube 11, and is formed into a so-called triple cylinder type as opposed to a so-called double cylinder type. The shock absorber may be a multiple-type hydraulic shock absorber including an ordinary triple cylinder.

The cylinder 1 shown in FIG. 1 is formed in a so-called single-tube structure, and the piston rod 2 is inserted into and retracted from the inside of the cylinder 1. The cylinder 1 is partitioned and formed by the piston portion 3 slidably accommodated therein. And a rod side chamber A and a piston side chamber B.

The rod-side chamber A and the piston-side chamber B are filled with an electrorheological fluid whose viscosity changes when a voltage is applied.

The cylinder 1 has a bearing member 12 whose upper end has the piston rod 2 inserted through the center thereof.
Is blocked while being connected to the
The bearing member 12 also closes the upper end of the inner tube 10 under the insulating material 8.

The bearing member 12 is the seal member 1.
It is connected to the inner periphery of the lower end side of the cap member 13 which holds 6 and allows the piston rod 2 to be inserted. The cap member 13 has its lower end connected to the upper end of the outer tube 11.

Further, the cylinder 1 is closed at the lower end thereof by the base valve portion 14, that is, in the state of being connected to the outer periphery of the valve body 14a forming the base valve portion 14 via the insulating material 8a. ing.

The valve body 14a also closes the lower end of the inner tube 10 under the insulating material 8a. The valve body 14a is supported in a state of being connected to a bottom member 15 disposed below the valve body 14a, and the bottom member 15 has the lower end of the outer tube 11 continuously connected to the upper end side thereof. .

The base valve portion 14 is a valve body 14
A reservoir formed in the piston side chamber B between the inner tube 10 and the outer tube 11 via a port 14b opened in a and a pressure side check valve 14c arranged so as to close the upper end side of the port 14b. It is supposed to communicate with the room R2.

The piston portion 3 has its piston body 3c.
The piston-side chamber B is communicated with the rod-side chamber A via the port 3d that is opened and the extension-side check valve 3a that is arranged so as to close the upper end side of the port 3d.

On the other hand, the port 1a is provided at the upper end of the cylinder 1.
Is opened, and the rod side chamber A is inserted through the port 1a.
Is outside the cylinder 1, that is, the cylinder 1 and the cylinder 1.
It is supposed to communicate with a control gap S formed between the inner tube 10 and the inner tube 10.

The spacing of the control gap S is set to about 1 mm as in the case of the above-mentioned conventional example. In this embodiment, the insulating material 8, 8a has a so-called wall thickness. It is set by adjustment.

A port 10a is opened at the lower end of the inner tube 10 so that the control gap S and the reservoir chamber R2 communicate with each other through the port 10a.

As a result, the electrorheological fluid flowing through the control gap S tends to always flow into the reservoir chamber R2.

The insulating materials 8 and 8a are formed of a synthetic resin, a ceramic material, or the like, and have a small diameter portion and a large diameter portion on the outer periphery thereof, and the upper and lower ends of the cylinder 1 are fitted to the outer periphery of the small diameter portion to form the outer periphery of the large diameter portion. The upper and lower ends of the inner cylinder 10 are fitted to each other.

The inner tube 10 is formed to be longer than the cylinder 1, and an elastic member 30 made of wave washer, disc spring, rubber or the like is also interposed between the lower end of the inner tube 10 and the upper surface of the valve body 14a so as to also seal. There is.

The elastic member 30 may be interposed between the upper end of the inner tube 10 and the bearing 12, or may be provided only at the upper end, the lower end or the extreme end of the cylinder 1.

By the way, in order to develop an electric field in the control gap S, a predetermined voltage is applied to both the positive electrode member and the negative electrode member, but in this embodiment, one electrode member is used. The cylinder 1 is set to the plus side, and the inner tube 10 serving as the other electrode member is set to the minus side.

The electric wire E1 extended from the external controller C or the power source is connected to the cylinder 1, and the electric wire E2 extended from the controller C is connected to the inner tube 10.

The wires E1 and E2 are the outer tube 1
In the case of penetrating through No. 1, the insulating material which is inserted into the insertion hole opened in the outer tube 11 under the liquid tight state is penetrated under the liquid tight state.

The electric wire E1 penetrates the inner tube 1 while being insulated, and is connected to the cylinder 1.

The connection method is not limited to this.

In this embodiment, the controller C receives a signal from the vehicle height sensor C1 mounted on the automobile, and when the shock absorber is mounted on the automobile and travels on the road, It is said that the amount of voltage applied to both electrode members is appropriately adjusted according to the condition of the traveling road surface.

Therefore, in the shock absorber using the electrorheological fluid according to the present embodiment formed as described above, when the shock absorber in which the piston rod 2 is retracted from the cylinder 1 is extended and retracted, the shock absorber is moved to the rod side chamber A. A certain electrorheological fluid will flow into the piston side chamber B via the control gap S, the reservoir chamber R2 and the base valve portion 14.

That is, in the shock absorber, the electrorheological fluid from the rod side chamber A always flows through the control gap S during the expansion and contraction operation, and thus the shock absorber functions as a so-called one-way type.

The surplus electrorheological fluid in the rod side chamber A during the pressure side operation of the shock absorber flows into the reservoir chamber R2 through the control gap S, and becomes insufficient in the piston side chamber B during the expansion side operation of the shock absorber. The electrorheological fluid is replenished from the reservoir chamber R2 via the base valve portion 14.

When a predetermined voltage is applied to the cylinder 1 which is one electrode member and the inner tube 10 which is the other electrode member during the expansion and contraction operation of the shock absorber, the control gap S formed between the two electrode members. An electric field is developed in.

The expression of the electric field causes the viscosity of the electrorheological fluid interposed therein, that is, flowing through the electric field, to be instantly changed to a hardening tendency, and thus the viscosity is changed. After that, the electrorheological fluid acts so as to prevent the electrorheological fluid from flowing through the control gap S.

As a result, the outflow of the electrorheological fluid from the rod side chamber A is hindered, and the slidability of the piston portion 3 in the cylinder 1 is hindered, which is manifested as a damping action. Of the piston rod 2 into the cylinder 1 and the piston rod 2 in the cylinder 1
The protrusion from the inside is hindered, and the shock absorber functions as a so-called shock absorber.

Therefore, if the applied voltage amount is appropriately controlled,
It becomes possible to immediately perform the damping action according to the applied voltage amount and smoothly perform a predetermined damping force adjustment without any steps.
When the shock absorber is mounted on an automobile, the damping action can be adjusted according to the condition of the road surface of the automobile, and the ride comfort of the automobile can be improved to a preferable state.

It should be noted that a plurality of inner tubes may be provided to form a multiple type, the control gap may be lengthened, and a large fluid resistance may not be generated in the vicinity of the port opening to the rod side chamber and the reservoir chamber.

[0068]

As described above, the present invention has the following effects.

Since the elastic member is interposed at the end portion of the inner tube or the cylinder, even if the inner cylinder and the cylinder have different lengths, the elastic member absorbs the nonuniformity of the length. Even if the accuracy is rough, the workability is improved.

Even if there is a difference in strain between the cylinder and the inner tube, or if there is a dimensional change in both due to temperature changes, the elastic material absorbs this dimensional change, causing play in the other cylinder or inner tube. do not do.

When the cylinder and the inner tube are electrode members and the fluid is an electrorheological fluid, the shock absorber has the following effects.

A. By controlling the applied voltage amount appropriately,
It becomes possible to immediately and smoothly execute a predetermined damping action, and when this is used as a shock absorber mounted on an automobile, it is possible to adjust the damping force according to the condition of the road surface of the automobile. For example, the riding comfort will be improved satisfactorily.

B. Since the control gap is formed in the so-called inside of the shock absorber so that the impact from the outside does not directly act, external force action such as impact on the outer periphery of the electrode member forming the control gap can be blocked in advance, and It becomes possible to maintain the spacing of the control gap as set.

C. Both electrode members are not exposed to the outside, and electric shock and leakage are prevented.

D. Since each end of the cylinder and the inner tube is insulated, it does not flow through other members such as bearings to other members regardless of whether the current is DC or AC, which prevents leakage and reduces power loss. It can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view showing a shock absorber using an electrorheological fluid according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a shock absorber using an electrorheological fluid as a conventional example.

[Explanation of symbols]

 1 Cylinder 3 Piston part 3a Extension side check valve 8, 8a Insulation material 10 Inner tube 11 Outer tube 14 Base valve part 14c Pressure side check valve 30 Elastic member A Rod side chamber B Piston side chamber R2 Reservoir chamber S Control clearance

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 28, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0036

[Correction method] Change

[Correction content]

[0036]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the structure of the present invention is such that an inner tube is arranged outside a cylinder, and an outer tube is arranged outside the inner tube. A reservoir chamber is formed between the outer tube and the piston, and the piston portion is slidably accommodated in the cylinder to define a rod side chamber and a piston side chamber in the cylinder, while the extension side of the piston portion is formed. The piston side chamber is connected to the rod side chamber via a check valve, and a control gap is formed between the cylinder and the inner tube so as to communicate with the rod side chamber and the reservoir chamber, and the reservoir chamber is at the lower end of the cylinder. It is connected to the piston side chamber via the pressure side check valve in the base valve part of the arrangement and connects both ends of the cylinder and the inner tube. In a shock absorber connected to a bearing and a valve body of a base valve, an upper end or a lower end of at least one of the cylinder and the inner tube is fitted to the bearing or the valve body via an elastic material. It is a thing.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0048

[Correction method] Change

[Correction content]

The spacing of the control gap S is set to about 1 m / m, as in the conventional example described above. In this example, the insulating material 8, 8a has a so-called thick wall thickness. Although it is set by adjustment, instead of this, it may be set by adjusting the wall thickness of the cylinder 1 or the inner tube 10.

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

Claims (1)

[Claims] 1. An inner tube is provided outside the cylinder, an outer tube is provided outside the inner tube, and a reservoir chamber is formed between the inner tube and the outer tube. Further, a piston is provided inside the cylinder. Part is slidably accommodated to partition and form a rod side chamber and a piston side chamber in the cylinder, while the piston side chamber is communicated with the rod side chamber via an extension side check valve in the piston part, and the cylinder and the inner tube are connected. A control gap that communicates with the rod side chamber and the reservoir chamber is formed between
Further, the reservoir chamber is communicated with the piston side chamber through the pressure side check valve in the base valve portion arranged at the lower end of the cylinder, and the both ends of the cylinder and the inner tube are connected to the bearing and the valve body of the base valve. A shock absorber in which the cylinder or the inner tube has an upper end or a lower end fitted to a bearing or a valve body via an elastic material.