JP2000136841A - Damper device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper device generating a small characteristic change even in the case of changing a temperature. SOLUTION: This device is constituted by a casing 1, movable unit 2 provided in the casing 1, operating fluid 4 sealed in the casing 1, and an orifice hole 6 allowing the operating fluid 4 to flow according to movement of the movable unit 2. This constitution is formed such that an area of the orifice hole 6 is changed so as to suppress changing of a damper characteristic by temperature dependence of physical properties of the operating fluid 4. Changing of the damper characteristic according to a change of temperature of the operating fluid 4 can be suppressed by generating a change so as to decrease the area of the orifice hole 6 in the case of increasing a temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damper device which suppresses fluctuations in damper characteristics due to temperature dependence of physical properties of a working fluid.

[0002]

2. Description of the Related Art Conventionally, a damper device for controlling the operation of a movable body generally has a structure as shown in FIG. The movable body 2 is disposed in the casing 1, and the linking member 3 is a shaft connected to the movable body 2 and protrudes outside the casing 1. The working fluid 4 such as oil is supplied to the casing 1.
The casing 1 and the movable body 2 are sealed by a seal member 5. The movable body 2 is provided with an orifice hole 6 through which the working fluid 4 passes as the movable body 2 moves. The movable body 2 is generally made of a metal material, and the orifice hole 6 is often provided in this metal material.

[0003] When a force acts on the movable body 2 in the direction of A through the linking member 3, the movable body 2 moves in the direction of A, passes through the orifice hole 6 provided in the movable body 2, and the working fluid 4 is removed. It flows upward from the lower side of the movable body 2. The movable body 2 receives a resistance force in the direction opposite to the direction A by the resistance force when the working fluid 4 flows through the orifice hole 5, and the operation speed becomes slow. Thereby, a damper effect is obtained.

[0004]

However, when the temperature of the damper device, that is, the temperature of the working fluid 4 changes, the physical properties of the working fluid change. In particular, since the viscosity and density of the working fluid 4 greatly affect the damper characteristics, the area of the orifice hole 6 does not change in the above-described conventional damper device, so that the damper characteristics fluctuate with the temperature fluctuation of the damper device. There was a problem that.

For example, as shown in a rack elevating type storage device shown in FIG. 9 (for example, JP-A-7-148029),
When the storage rack 7 is pulled down, the damper device 8 acts so that the storage rack 7 descends slowly. However, if the characteristics of the damper 8 fluctuate due to environmental temperature, etc., the descent speed will fluctuate depending on the region, season, time zone, and the like. There is a problem that it becomes slow and the usability deteriorates, and it is not desirable that the damper characteristics change with temperature.

[0006]

In order to solve the above-mentioned problems, the present invention provides a casing, a movable body provided in the casing, a working fluid sealed in the casing, and And the orifice hole through which the working fluid flows, and the area of the orifice hole changes so as to suppress the fluctuation of the damper characteristic due to the temperature dependency of the physical properties of the working fluid.

According to the above invention, even if the physical properties such as the viscosity and density of the working fluid change due to the temperature fluctuation of the working fluid, the area of the orifice hole changes in a direction to suppress the fluctuation of the damper characteristics due to the change. For this reason, it is possible to suppress a change in the damper characteristic due to a change in the temperature of the working fluid.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, a casing, a movable body provided in the casing, a working fluid sealed in the casing, and a moving body of the movable body are provided. And an orifice hole through which the working fluid flows, wherein the area of the orifice hole changes so as to suppress fluctuations in damper characteristics due to temperature dependence of physical properties of the working fluid.

Even if the physical properties such as the viscosity and density of the working fluid change due to the temperature fluctuation of the working fluid, the area of the orifice hole changes in a direction to suppress the fluctuation of the damper characteristics due to the change. For this reason, it is possible to suppress a change in the damper characteristic due to a change in the temperature of the working fluid.

[0010] According to the second aspect of the present invention, the casing, the movable body disposed in the casing, the working fluid sealed in the casing, and the working fluid flow with the movement of the movable body. And orifice holes,
An area of the orifice hole changes according to a force applied to the movable body, and an area of the orifice hole changes so as to suppress a change in damper characteristics due to a temperature dependency of physical properties of the working fluid.

When a force acts on the movable body, the area of the orifice hole changes according to the force, so that a damper characteristic different from that of the fixed orifice hole can be obtained. For example, it is possible to obtain a damper characteristic that operates at a substantially constant speed even when the load changes. Also, in the case of such a damper device, the area of the orifice hole changes in a direction to suppress a change in the damper characteristic due to a change in the temperature of the working fluid. Variations in characteristics can be suppressed.

According to the third aspect of the present invention, the orifice hole is formed in an elastic body. When a force acts on the movable body, the working fluid, that is, the internal pressure of the casing changes, and the orifice hole receives the internal pressure. The elastic body is deformed. The orifice hole is formed in this elastic body, and the shape and area of the orifice hole change with the deformation of the elastic body. For this reason, the area of the orifice hole can be easily changed according to the force acting on the movable body, and a damper having arbitrary characteristics can be obtained. In addition, elastic materials such as resin and rubber have a larger coefficient of thermal expansion (approximately 10 times) than metal materials, so that the thermal expansion can be used to suppress fluctuations in damper characteristics due to temperature changes. It is. Further, although the amount of change in the physical properties varies depending on the type of the working fluid, a damper device corresponding to various fluids can be obtained by using elastic bodies having different thermal expansion coefficients.

Further, in the invention according to the fourth aspect, the area of the orifice hole becomes smaller as the temperature of the damper device rises. In the most common damper device using a liquid such as oil as a working fluid, the operating speed tends to increase because the viscosity of the fluid decreases as the temperature increases. For this reason, if the area of the orifice hole is deformed to be small according to the temperature rise of the damper device, this change can be corrected, and the change in the damper characteristic due to the temperature change can be suppressed.

Further, in the invention described in claim 5, the orifice hole is provided in the orifice member, and the area of the orifice hole is changed by thermal expansion of the orifice member. If the thermal expansion of the orifice member is used, the area of the orifice hole provided in the orifice member can be automatically enlarged or reduced, and the fluctuation of the damper characteristic due to the temperature change can be suppressed. Although the amount of change in the physical properties varies depending on the type of the working fluid, the use of the orifice member having a different coefficient of thermal expansion makes it possible to obtain a damper device compatible with various fluids.

[0015]

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

(Embodiment 1) FIG. 1 is a sectional view of a damper device according to Embodiment 1 of the present invention. In FIG. 1, inside a cylindrical casing 1, there is a movable body 2 made of a rigid body such as a metal that moves along the inside of the casing 1.
Is connected to a linking member 3 which is a shaft penetrating a part of the casing 1. A working fluid 4 such as oil is sealed in the casing 1, and a seal member 5 such as an O-ring or an X-ring seals a gap between the casing 1 and the movable body 2. Further, an orifice member 9 made of a material having a relatively large coefficient of thermal expansion such as resin is provided in a concave portion of the movable body 2, and an orifice hole 6 is formed in the orifice member 9. Here, the orifice hole 6 is a pore having a size extremely smaller than the diameter of the casing 1. Further, a passage for allowing the working fluid 4 to pass through the movable body 2 is formed so as to communicate with the orifice hole. Further, an air layer separating means 11 for separating the air layer 10 and the working fluid 4 existing in the casing 1 and a compression spring 12 are provided.

Next, the operation and action will be described. When a force (a force acting in the direction B) for pushing the linking member 3 as a shaft into the casing 1 is applied, the force is applied to the movable body 2 via the linking member 3. And the working fluid 4a on the left side of the movable body 2
Press. The working fluid 4a flows from the left side to the right side of the movable body 2 through the orifice hole 6 provided in the orifice member 9 and the passage provided in the movable body 2. Due to this flow, the movable body 2 moves from the right side to the left side (in the direction of B), but the movable body 2 moves in the direction opposite to B due to the resistance force when the working fluid 4 flows through the orifice hole 6 which is a fine hole. Due to the resistance, the operation speed becomes slow. This is the damper effect. The moving speed of the movable body 2, that is, the damper characteristic largely depends on the shape and area of the orifice hole 6 and the viscosity and density of the working fluid 4.

If the temperature of the working fluid differs due to a difference in environmental temperature or the like, the physical properties such as the viscosity and density of the working fluid 4 also differ. That is, the damper characteristic fluctuates due to a temperature change. However, in the present invention, a change in the area of the orifice hole 6 acts so as to suppress a change in damper characteristics due to a change in physical properties of the working fluid 4 due to a temperature change. That is, when the viscosity of the fluid increases due to temperature fluctuation, the area of the orifice hole 6 increases, and when the viscosity decreases, the area of the orifice hole 6 decreases.
As a result, it is possible to suppress a change in the damper characteristics due to a temperature change.

In this embodiment, the orifice hole 6 is formed in the orifice member 9, and the area of the orifice hole 6 is changed by utilizing the thermal expansion of the orifice member 9. Generally, the orifice hole 6 is often provided in a metal material, and since the metal material has a relatively small coefficient of thermal expansion, it was not possible to obtain a deformation enough to suppress a change in the physical properties of the working fluid 4. By using a material such as a resin having a relatively large coefficient of thermal expansion as the material of the orifice portion 9, the amount of change in the area of the orifice hole 6 becomes large, and the characteristic change due to a temperature change can be further suppressed.

FIG. 2 shows the relationship between the temperature and the operating speed of the damper. C is a case of a metal orifice member, and D is an example of a case where a resin orifice member is used to suppress a change in damper characteristics due to a temperature change. The decrease in the operation speed in the low temperature region is moderated.

Further, even when a material having a relatively large coefficient of thermal expansion such as resin is used, the area of the orifice hole 6 may increase or decrease due to a rise in temperature depending on the configuration. Needs to be transformed to the side that corrects. In an oil damper or the like in which a liquid such as oil is used as the working fluid 4, the viscosity of the working fluid 4 is most affected by the temperature dependency, and the viscosity decreases as the temperature rises. Be faster. Therefore, by making the orifice hole 6 small, fluctuations in the damper characteristics due to temperature changes can be suppressed.
For example, as shown in FIG. 3 (a), when the orifice hole 6 is simply provided in the flat movable body 2, as shown in a partially enlarged view around the orifice hole 6, the area of the orifice hole 6 increases as the temperature rises. Tend to increase, and it is not possible to suppress characteristic fluctuations due to temperature changes. On the other hand, as shown in FIG. 3B, when the orifice member 9 made of a resin material having a large thermal expansion is fitted to the movable body 2 made of a metal material having a small thermal expansion, the area of the orifice hole 6 is reduced. And characteristic fluctuations can be suppressed.

In the first embodiment, the example in which the orifice hole 6 moves together with the movable body 2 has been described. However, the structure is not particularly limited as long as the working fluid 4 passes with the movement of the movable body 2. . For example, the orifice hole 6 may be fixed to the casing 1.

FIG. 1 shows an example in which the orifice area is automatically changed in accordance with the temperature change. However, the present invention is not limited to this. The temperature of the working fluid is detected, and the area of the orifice hole is changed by a motor or the like. Such a configuration may be adopted. The same operation and effect can be obtained when the invention is applied not only to a damper but also to a shock absorber.

(Embodiment 2) FIG. 4 is a partially enlarged sectional view of a damper device according to Embodiment 2 of the present invention, and the same reference numerals are given to the same components as those of Embodiment 1 shown in FIG. The description is omitted.

Embodiment 2 is an example in which the thermal expansion of the orifice member is not used, and a bimetal 13 in which dissimilar metals having different thermal expansion coefficients are bonded to each other is provided. The deformation of the bimetal 13 due to the temperature change is utilized. The deformation of the bimetal 13 acts to deform the orifice member 9 formed of an elastic member, and changes the area of the orifice hole 6 by this deformation. When the viscosity of the working fluid 4 decreases, the bimetal 13 deforms so as to compress the orifice member, the orifice hole 6 becomes small, and the fluctuation of the damper characteristic due to the temperature change can be suppressed.

(Embodiment 3) FIGS. 5A and 5B are partially enlarged sectional views of a damper device according to Embodiment 3 of the present invention.
The same reference numerals are given to the same components as those of the first embodiment shown in FIG.

The overall structure of the damper device is the same as that of the first embodiment, except that an elastic member 14 such as rubber is provided in the concave portion of the movable member 2 and the orifice hole 6 is provided in the elastic member 14. In this embodiment, rubber is used as an example of the elastic body. However, rubber includes natural rubber, synthetic rubber, and the like, and other elastic bodies include resin, elastomer, foam having elasticity, and the like.

This embodiment has the following operation and effect in addition to the operation of the first embodiment. When the working fluid 4 on the left side of the movable body 2 is pressurized, the pressure of the working fluid 4 also acts on the left surface of the elastic body 14. As a result, as shown in FIG. 5B, the elastic body 14 is pressurized, and the area of the orifice hole 6 provided in the elastic body 14 also changes. Further, if the force applied to the movable body 2 changes, the pressure of the working fluid 4 also changes, so that the pressure acting on the elastic body 14 also changes, and the deformation of the elastic body 14 and the shape or area of the orifice hole 6 also change. I do. Therefore, the area of the orifice hole 6 changes according to the force applied to the movable body 2, that is, the damper device.

In the configuration shown in FIG. 5, if the force acting on the movable body 2 increases, the amount of compression of the elastic body 14, that is, the orifice hole 6
Also tends to increase, and the area of the orifice hole 6 tends to decrease. That is, the relationship between the damper load (the force acting on the movable body) indicating the characteristics of the damper and the operation speed of the movable body 2 is as follows.
In a fixed orifice provided in a general rigid body, the relationship is as shown in FIG. 6E, while in the damper device of the present invention, the relationship is as shown in F, for example. Therefore, even when the load increases, the moving speed of the movable body 2 acts to be suppressed, and the operating speed of the movable body 2 can be stably maintained at a certain safe speed or less. Also, as shown in FIG. 7, when the load exceeds a certain load, it is possible to obtain a damper having such characteristics that the operation speed is substantially constant even if the load varies.

[0030] Even in the case of a damper device having such characteristics, the physical properties of the working fluid change with the temperature change of the damper device, so that the damper characteristics fluctuate. However, as in the first embodiment, a change in the area of the orifice hole acts in a direction to suppress a change in the damper characteristics due to a temperature change, so that the change in the characteristics can be reduced. Moreover, in the present embodiment, a rubber material having a relatively large coefficient of thermal expansion is used as the elastic body, and since the amount of change in the orifice hole is large, it is possible to further alleviate the change in the characteristic due to the temperature change.

[0031]

As described above, according to the present invention, the area of the orifice hole changes so as to suppress the fluctuation of the damper characteristic due to the temperature dependence of the physical properties of the working fluid. The accompanying fluctuation of the damper characteristics can be suppressed.

Further, the area of the orifice hole changes according to the force applied to the movable body, and the area of the orifice hole changes so as to suppress the fluctuation of the damper characteristics due to the temperature dependence of the physical properties of the working fluid. In this case, the damper characteristic is varied in accordance with the force acting on the movable body, and when an arbitrary damper characteristic is obtained, the fluctuation of the damper characteristic due to the temperature change of the working fluid during operation can be suppressed. .

In the case where the orifice hole is formed in an elastic body, if a force acts on the movable body, the working fluid, that is, the internal pressure of the casing changes, and the elastic body is deformed by receiving the internal pressure. The orifice hole is formed in this elastic body,
The shape and area of the orifice hole change with the deformation of the elastic body. Therefore, according to this configuration, the area of the orifice hole can be easily changed according to the force acting on the movable body, and the damper characteristics can be controlled. Elastic bodies such as resin and rubber have a larger coefficient of thermal expansion than metal materials (about 10 times).
Therefore, by utilizing the thermal expansion, it is possible to suppress the fluctuation of the damper characteristic due to the temperature change. Further, although the amount of change in the physical properties varies depending on the type of the working fluid, a damper device corresponding to various fluids can be obtained by using elastic bodies having different thermal expansion coefficients.

In the case where the area of the orifice hole changes small as the temperature of the damper device rises, the damper characteristic accompanying the temperature change in the most common damper device using a liquid such as oil as the working fluid. Can be suppressed.

The orifice hole is provided in the orifice member, and when the area of the orifice hole changes due to the thermal expansion of the orifice member, the area of the orifice hole can be automatically enlarged or reduced by the thermal expansion of the orifice member. ,
It is possible to suppress the fluctuation of the damper characteristic due to the temperature change. Although the amount of change in the physical properties varies depending on the type of the working fluid, the use of the orifice member having a different coefficient of thermal expansion makes it possible to obtain a damper device compatible with various fluids.

[Brief description of the drawings]

FIG. 1 is a sectional view of a damper device according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a temperature of the damper device and an operation speed of a movable body.

3A is a partially enlarged sectional view of the damper device, and FIG. 3B is a partially enlarged sectional view of the damper device.

FIG. 4 is a partially enlarged view of a damper device according to a second embodiment of the present invention.

5A is a partially enlarged sectional view of a damper device according to a third embodiment of the present invention. FIG. 5B is a partially enlarged sectional view of the damper device when a force is applied leftward.

FIG. 6 is a characteristic diagram showing a relationship between a load of the damper device and an operation speed of a movable body.

FIG. 7 is a characteristic diagram showing a relationship between a load of the damper device and an operation speed of a movable body.

FIG. 8 is a sectional view of a conventional damper device.

FIG. 9 is a side view showing an example of use of the damper device.

[Explanation of symbols]

 Reference Signs List 1 casing 2 movable body 3 linking means 4 working fluid 6 orifice hole 9 orifice member 14 elastic body

Claims (5)

[Claims] A movable body provided in the casing, a working fluid sealed in the casing, and an orifice hole through which the working fluid flows as the movable body moves. A damper device in which an area of the orifice hole changes so as to suppress a change in damper characteristics due to a temperature dependency of a physical property of a fluid. And a movable body disposed in the casing, a working fluid sealed in the casing, and an orifice hole through which the working fluid flows as the movable body moves. A damper device wherein the area of the orifice hole changes according to a force applied to a body, and the area of the orifice hole changes so as to suppress a change in damper characteristics due to temperature dependence of physical properties of the working fluid. 3. The damper device according to claim 1, wherein the orifice hole is formed in an elastic body. 4. The damper device according to claim 1, wherein the area of the orifice hole decreases as the temperature of the damper device increases. 5. The damper device according to claim 1, wherein the orifice hole is provided in the orifice member, and the area of the orifice hole is changed by thermal expansion of the orifice member.