JPH062732A - Buffer - Google Patents

Abstract

PURPOSE:To widen an attenuating force adjusting width and improve general applicability in a buffer for a motorcar by arranging multiple odd-numbered inner tubes outside a cylinder, arranging an outer tube outside thereof, adapting the even number inner tube and the odd number inner tube respectively to electrodes, and forming serial controlling gaps between the cylinder and the. respective inner tubes. CONSTITUTION:Multiple inner tubes 10 having odd-number structure are arranged outside a cylinder 1 with a distance. An outer tube 11 is arranged outside the multiple inner tubes 1. A reserver chamber R2 is formed between an outermost inner tube a3 and the outer tube 11. A piston side chamber B is communicated with a rod side chamber A through an extending side check valve 3a of a piston 3. Controlling gaps S1 to S3 communicated with the rod side chamber A and the reserver chamber R2 are formed between the cylinder 1 and an innermost inner tube a1, and between respective inner tubes a1, a2, and a3. The reserver chamber R2 is communicated with a base valve chamber 14 through a check valve 14c. The even numbered inner tube a2 and the cylinder 1 serve as one electrode, while the odd numbered inner tubes a1 and a3 serve as the other electrode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorber capable of adjusting a generated damping force by utilizing the 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.

[0025]

However, in the shock absorber using the electrorheological fluid as the conventional example described above,
There is a security drawback and there is a danger that the desired damping effect cannot be expected. That is, in the shock absorber according to the conventional example, 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.
At the same time, the intermediate tubular body 6 serving as the other 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 danger of electric shock if the human body touches them.

Further, even when it is mounted on an automobile, there is a risk of electric current leakage due to contact with other parts through the bearing member 7 or the like, 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-mentioned 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. Furthermore, since only one control gap S is provided between the cylinder 1 and the intermediate tubular body 6, the length thereof is short and the effective damping force control width for a certain applied voltage is small. There is.

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 electric 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, in which the action is realized as set, the damping force adjustment range can be increased, and the versatility can be expected to be improved.

[0032]

In order to achieve the above-mentioned object, the structure of a shock absorber using electrorheological fluid according to the present invention is such that an inner tube composed of a plurality of odd numbers is provided outside the cylinder at an arbitrary interval. Multiple layers are arranged, an outer tube is arranged outside the outermost inner tube, a reservoir chamber is formed between the outermost inner tube and outer tube, and the piston part can slide inside the cylinder. The rod side chamber and the piston side chamber are defined and formed in the cylinder while being housed, and the piston side chamber is communicated with the rod side chamber via the extension side check valve in the piston portion,
A series control gap is formed between the cylinder and the innermost inner tube, and between each inner tube 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 base valve part, and each end of the cylinder and each inner tube is connected to the bearing and the valve body of the base valve via an insulating material, and is even with the cylinder. The second inner tube serves as one electrode member, while the odd inner tube serves as the other electrode member.

[0033]

The outer tube serves as a so-called cover body, and it is possible to prevent external force such as impact from acting on the outer circumference of each inner tube, which is an electrode member forming a so-called control gap inside the shock absorber. Therefore, it becomes possible to maintain the spacing of the control gap as set.

Further, since the cylinder which is the electrode member and the inner tube are arranged in the outer tube and each electrode member is insulated by the insulating material, the electrode member is not exposed to the outside, and the electric current passes through other members. Since it does not flow to the outside, electric shock and leakage are prevented.

A long control gap is formed between the cylinder and the multiple inner tubes to increase the flow resistance with respect to a predetermined voltage and to increase the damping force adjustment range.

[0036]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below with reference to the illustrated embodiment. The embodiment shown in FIG. 1 is a shock absorber for an automobile. Inner tube 10 and outer tube 11
And, and is formed in a so-called multiple cylinder type as opposed to a so-called multiple cylinder type.

The inner tube 10 is multiply assembled by an odd number of the first inner tube a1, the second inner tube a2, and the third inner tube a3. However, an even number may be used depending on the voltage application method,
Alternatively, it may be an odd number of three or more.

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

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.

Further, the cylinder 1 has a bearing member 12 whose upper end has a piston rod 2 inserted through the center thereof.
Is blocked while being connected to the
The bearing member 12 includes the inner tubes a1, a
The upper ends of 2 and a3 are also closed under the distribution of the insulating material 8.

The bearing member 12 is the seal member 1.
It is arranged at the lower end side of the cap member 13 that holds 6 and inserts the piston rod 2. 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.

In this valve body 14a, the lower end of each inner tube a1, a2, a3 is also covered with the insulating material 8a.
It is blocked under the control of.

The valve body 14a is supported by being connected to a bottom member 15 disposed below the valve body 14a. The bottom member 15 has its upper end connected to the lower end of the outer tube 11. ing.

The base valve portion 14 is a valve body 14
Port 14b which is a passage opened in a and the port 14
The piston side chamber B is communicated with a reservoir chamber R2 formed between the outermost inner tube a3 and the outer tube 11 via a check valve 14c that opens and closes the upper end side of b.

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 a passage that is opened and the extension side check valve 3a that is arranged to open and close the port 3d.

On the other hand, between the cylinder 1 and the first inner tube a1, the first and second inner tubes a1, a
2, annular gaps s1, s2, s2 that form a control gap S that communicates in series with the second and third inner tubes a2, a3 via the ports 10b, 10c are formed. There is.

A port 1a is opened at the upper end of the cylinder 1, and the rod-side chamber A is disposed outside the cylinder 1, that is, between the cylinder 1 and the outside of the cylinder 1 through the port 1a. It is supposed to communicate with the control gap S formed between the inner inner tube a1.

The spacing of the control gap S is set to about 1 mm, for example, as in the case of the above-mentioned conventional example. In this embodiment, the insulating materials 8 and 8a and the inner tube 10 described above are used. It is said that it is set by adjusting the so-called thickness.

A port 10a is opened at the lower end of the outermost inner tube a3 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 always tends to flow into the reservoir chamber R2.

By the way, in order to develop an electric field in the control gap S, a predetermined voltage is applied to both the positive and negative electrode members, but in this embodiment, one electrode member is used. The cylinder 1 and the even-numbered inner tubes a2 are set to the plus side, for example, and the odd-numbered inner tubes a1 and a3 to be the other electrode members are set to the minus side.

The cylinder 1 and the inner tube a
2, an electric wire E1 extended from an external controller C or a power source is connected to the inner tube a1,
The electric wire E2 extended from the controller C is connected to a3.

The wires E1 and E2 are the outer tube 1
1 and the inner tube 10 are penetrated in a liquid-tight state with an insulating material fitted in a liquid-tight state into an insertion hole for opening.

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, for example, a signal from a vehicle height sensor mounted on an automobile is input to the controller C, and when a shock absorber is mounted on the automobile to travel on a road surface, 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 this 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 rod side chamber A Gaps s1, s2 in
The electrorheological fluid composed of s2 flows into the piston side chamber B via the control gap S, the reservoir chamber R2 and the check valve 14c of the base valve portion 14.

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

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 and the inner tube a2, which are one electrode member, and the inner tubes a1 and a3, which are the other electrode members, when the shock absorber expands and contracts, it is formed between both electrode members. An electric field is developed in the controlling gap S.

The expression of the electric field causes the viscosity of the electrorheological fluid interposed there, 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.

Moreover, since the control gap S becomes the total length of the gaps between the multiple inner tubes and becomes longer, and the flow resistance can be increased, the damping force can be set high even with the same predetermined voltage, and the damping force can be adjusted. The width increases.

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 riding comfort of the automobile can be improved to a preferable state.

[0065]

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

By appropriately controlling the amount of applied voltage, it becomes possible to immediately and smoothly execute a predetermined damping action. When this is used as a shock absorber mounted on an automobile, the traveling road surface of the automobile is The damping force can be adjusted according to the situation, and the riding comfort of the automobile can be improved satisfactorily.

Since the control gap is formed inside what is called a shock absorber so that an external impact does not act directly, it is possible to prevent an external force action such as an impact on the outer periphery of the electrode member forming the control gap in advance. As a result, the control gap can be maintained as set.

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

Since both ends of the cylinder and each inner tube are insulated, current does not flow to other members through other members such as bearings even if the current is DC or AC, and leakage is prevented. It is possible to prevent power loss.

Since the inner tubes are multiply arranged and the control gap is formed between them, the length of the control gap becomes long.

Therefore, the flow resistance can be increased and the damping force can be set high even with the same voltage, so that the adjustment range of the damping force can be increased.

[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 1a port 3 piston part 3a extension side check valve 8, 8a insulating material 10 inner tube 10a, 10b, 10c port 11 outer tube 14 base valve part 14c pressure side check valve A rod side chamber B piston side chamber R2 reservoir chamber S control gap a1, a2, a3 inner tube s1, s2, s2 clearance

Claims (1)

[Claims] 1. An outer tube is arranged on the outer side of an outermost inner tube, and an outer tube is arranged on the outer side of the outermost inner tube. And a piston chamber is slidably accommodated in the cylinder to define a rod side chamber and a piston side chamber in the cylinder, while the extension side check valve in the piston unit is formed. The piston side chamber is communicated with the rod side chamber via the, and a series control gap is formed between the cylinder and the innermost inner tube and between each inner tube to communicate with the rod side chamber and the reservoir chamber. , The reservoir chamber is communicated with the piston side chamber via a pressure side check valve in a base valve portion arranged at the lower end of the cylinder. Each end of the inner tube and each inner tube is connected to the bearing and the valve body of the base valve through an insulating material, and the cylinder and the even inner tube are used as one of the electrode members. A shock absorber, wherein the inner tube is the other electrode member.