JPH11210801A - Rotary damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform compensation corresponding to the changes in damping force based on temperature changing. SOLUTION: Set springs 11 are provided between one end of each of ring- shaped plates 8 and 4 and the left side end face side wall 2c of a ring-shaped housing 2, and the external peripheral side temperature compensation member 12 constituting the temperature compensation mechanism provided in the right side end face side wall 2d of the ring-shaped housing 2 and an internal peripheral side temperature compensation member 13 are made of different materials whose coefficient of axial linear thermal expansion are different from each other, and engaging step sections 12a and 13a, which axially face to each other with a specified clearance L between them while temperature is low and the clearance L is filled up as temperature rises and the external peripheral side temperature compensation member 12 whose coefficient of the linear thermal expansion is larger moves the external peripheral side temperature compensation member 13 whose coefficient of the linear thermal expansion is lower toward the ring-shaped plates 8 and 4, are formed between the external peripheral side temperature compensation member 12 and the internal peripheral side temperature compensation member 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary damper which is provided, for example, on a rotary bearing of a lower arm or an upper arm of a vehicle to attenuate the rotation of the arm.

[0002]

2. Description of the Related Art Conventionally, as a rotary damper, for example, a rotary damper described in Japanese Patent Application Laid-Open No. 8-82333 filed by the present applicant has been known. This conventional rotary damper has a substantially cylindrical housing, a rotating shaft rotatably provided at an axial center of the housing, and a rotation transmitting device capable of transmitting rotation to the housing within the housing and extending in an axial direction. A sub-housing that is engaged in a relative slidable state and is provided in a state in which rotation and axial sliding are possible with respect to the rotary shaft, thereby forming a sealed chamber between the sub-housing and the rotary shaft. A predetermined number of disc-shaped plates are provided on the outer periphery of the rotary shaft and the inner periphery of the sub-housing in such a manner that side surfaces face each other in the closed chamber in the axial direction, and between the housing and the sub-housing, A pressure receiving chamber whose volume is changed by relative sliding in the axial direction is formed, and a communication hole communicating between the pressure receiving chamber and the sealed chamber is formed in the sub-housing. Biasing means for slidingly biasing the sub-housing in a direction in which the volume of the pressure receiving chamber is reduced and in a direction in which the axial distance between the two plates is maximized is provided between the closed chamber and the pressure receiving chamber. Is configured to be filled with viscous fluid, and by configuring as described above, the volume change of the viscous fluid due to the temperature change is utilized, and the damping of the viscosity itself of the viscous fluid due to the temperature change is performed. The fluctuation of the force was automatically corrected by changing the gap between the two disk-shaped plates and changing the viscous resistance.

[0003]

However, in the above-described conventional rotary damper, as described above, the volume change of the viscous fluid based on the temperature change of the viscous fluid is used. There were serious problems. That is, the change in viscosity of the viscous fluid with respect to the change in temperature of the viscous fluid is non-linear, whereas the change in volume based on the change in temperature of the viscous fluid is linear. I can't.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide a rotary damper capable of correcting a change in damping force based on a change in temperature.

[0005]

According to a first aspect of the present invention, there is provided a rotary damper comprising: a housing in which outer peripheral sides of both side walls are connected by a cylindrical portion; A rotating shaft provided in a state where relative rotation is possible and movement in the axial direction is prevented, and a sealed chamber filled with a viscous fluid is formed between the rotating shaft and the housing. A housing-side plate and a rotating shaft-side plate, which are provided alternately in the axial direction on the periphery and the outer periphery of the rotating shaft, respectively, and the two sides face each other with a predetermined gap,
The housing side plate and the rotating shaft side plate are provided so as to be capable of transmitting rotation to the housing cylinder portion or the rotating shaft, respectively, and at least one of the housing side plate and the rotating shaft side plate is axially movable. A pressing means is provided between the one end face of the plate and one end face side wall of the housing to press the plate in the direction of the other end face side wall. The end face side wall is provided with a temperature compensation mechanism for nonlinearly changing the gap by non-linearly moving the plate relative to the axial direction in response to a temperature change. According to a second aspect of the present invention, in the rotary damper according to the first aspect, the housing-side plate and the rotating shaft-side plate are provided so as to be capable of transmitting rotation to the housing cylinder portion or the rotating shaft, respectively, and being movable in the axial direction, Pressing means for pressing and urging the plate in the direction of the other end surface side wall is provided between one end surface of the housing side plate and the rotation shaft side plate and one end surface side wall of the housing, respectively. A temperature compensation mechanism including an outer peripheral temperature compensating member and an inner peripheral temperature compensating member that abuts against the other end surfaces of the housing-side plate and the rotating shaft-side plate to receive the axial movement is provided on the end surface side wall. The outer temperature compensating member and the inner temperature compensating member constituting the two temperature compensating mechanisms have mutually different linear expansion coefficients in the axial direction. Between the outer peripheral side temperature compensating member and the inner peripheral side temperature compensating member at a low temperature, have a predetermined clearance, and face each other in the axial direction. The larger temperature compensating member is provided with an engaging portion for moving the lower temperature compensating member in the plate direction. According to a third aspect of the present invention, there is provided a rotary damper according to the second aspect, wherein a plurality of the engaging portions are formed in a step-like manner, and a clearance of each of the engaging portions is set so as to gradually increase toward the plate direction. did. According to a fourth aspect of the present invention, in the rotary damper according to the first aspect, the housing-side plate and the rotating shaft-side plate are provided so as to be capable of transmitting rotation to the housing cylinder portion or the rotating shaft and moving in the axial direction, respectively. Pressing means for pressing and urging the plate in the direction of the other end surface side wall is provided between one end surface of the housing side plate and the rotation shaft side plate and one end surface side wall of the housing, respectively. A temperature compensating member composed of a low-temperature-side temperature compensating member and a high-temperature-side temperature compensating member that abuts against the other end surfaces of the annular housing-side plate and the rotating shaft-side plate at the set intermediate temperature to receive the axial movement. A mechanism is interposed, and the low temperature side temperature compensating member and the high temperature side temperature compensating member mutually linearly expand in the radial direction. It is formed in a ring shape with different numbers of materials, and between the inner peripheral edge on the end face side wall side and the end face side wall of the low temperature side temperature compensating member, changes in radial dimensional shrinkage of the low temperature side temperature compensating member due to temperature decrease are moved in the axial direction. A low-temperature side cam surface to be converted is formed, and a change in the radial dimensional expansion of the high-temperature side temperature compensating member due to a temperature rise is converted into an axial movement between the outer peripheral edge of the end surface side wall and the end surface side wall of the high-temperature side temperature compensating member. The high temperature side cam surface is formed. According to a fifth aspect of the present invention, in the rotary damper according to the fourth aspect, the low-temperature side cam surface and the high-temperature side cam surface are formed as curved surfaces. According to a sixth aspect of the present invention, there is provided the rotary damper according to the first aspect, further comprising a temperature detecting means for detecting a temperature of the viscous fluid, wherein the temperature compensating mechanism responds to a temperature change of the viscous fluid detected by the temperature detecting means. The means comprises an actuator and a control means for nonlinearly changing the gap by relatively moving the plate in a non-linear manner relative to the axial direction.

[0006]

In the rotary damper according to the first aspect of the present invention,
Due to the above-described configuration, when the rotation shaft and the housing rotate relative to each other, the rotation shaft side plate and the housing side plate adjacent to each other rotate relative to each other, and the viscous fluid filled in the gap between the two plates is removed. A viscous friction force is generated when forcibly moving at a flow velocity corresponding to the relative rotation speed, and a predetermined damping force is generated by viscous resistance due to the viscous friction force. When the temperature of the viscous fluid changes, the viscous resistance of the viscous fluid changes non-linearly, so the generated damping force changes non-linearly with respect to the temperature change. By moving the plates in a non-linear manner relative to each other in the axial direction, the gap between the two plates is changed in a non-linear manner, so that the viscous resistance due to the relative rotation of the two plates is changed. Automatic damping force change is automatically corrected. In the rotary damper according to the second aspect, when the temperature of the viscous fluid is in a low temperature state, a predetermined clearance is formed in the engaging portion formed between the outer peripheral side temperature compensating member and the inner peripheral side temperature compensating member. Therefore, when the temperature of the viscous fluid rises, the outer peripheral temperature compensating member and the inner peripheral temperature compensating member having different linear expansion coefficients expand in the axial direction. In order to reduce the gap between the two plates by the pressing movement, thereby reducing the gap between the two plates by the linear expansion coefficient difference, the viscous resistance due to the relative rotation of the two plates increases, and the decrease in the damping force due to the temperature rise of the viscous fluid is automatically corrected. When the temperature of the viscous fluid further increases from the time when the predetermined clearance decreases and the engaging portions engage with each other, the temperature compensating member having the larger linear expansion coefficient becomes the temperature compensating member having the smaller linear expansion coefficient. , The clearance decreases in a direction in which the rate of decrease of the gap with respect to the temperature change decreases, whereby the damping force correction with respect to the temperature change can be performed nonlinearly. Therefore, the fluctuation of the damping force with respect to the temperature change can be reduced. In the rotary damper according to the third aspect, the rate of decrease of the gap with respect to the temperature rise changes in a direction to decrease in a plurality of steps. Therefore, the fluctuation of the damping force with respect to the temperature change can be further reduced.

In the rotary damper according to the present invention, when the temperature of the viscous fluid is the set intermediate temperature, the low temperature side temperature compensation member and the high temperature side temperature compensation member are in contact with the annular housing side plate and the rotary shaft side plate. When the temperature of the viscous fluid changes from this state to a direction in which the temperature of the viscous fluid decreases, the change in the radial dimensional shrinkage of the low-temperature side temperature compensating member is converted to axial movement by the low-temperature side cam surface, and the housing or the rotating shaft side plate is changed. To move the plate in the axial direction, thereby increasing the gap between the two plates, reducing the viscous resistance due to the relative rotation of the two plates, and increasing the damping force due to the decrease in the temperature of the viscous fluid. It is automatically corrected by the change rate according to the value of the linear expansion coefficient. Further, when the temperature of the viscous fluid changes from the set intermediate temperature to a rising direction, the change in the radial dimensional expansion of the high temperature side temperature compensating member is converted into axial movement by the high temperature side cam surface,
The housing or the rotating shaft side plate is pressed and moved in the axial direction, thereby reducing the gap between the two plates, increasing the viscous resistance due to the relative rotation of the two plates and reducing the damping force due to the temperature rise of the viscous fluid. It is automatically corrected by the change rate according to the value of the linear expansion coefficient of the high temperature side temperature compensating member. As described above, since the correction change rate of the damping force differs between the low temperature side change and the high temperature side change of the viscous fluid, the damping force correction for the temperature change can be performed in a non-linear manner. Therefore, the fluctuation of the damping force with respect to the temperature change can be reduced. In the rotary damper according to the fifth aspect, the damping force correction for the temperature change is performed in a curved manner by moving in the axial direction along the curved surfaces of the cam surface on the low temperature side and the high temperature side, whereby the damping force for the temperature change is obtained. Fluctuations can be further reduced. In the rotary damper according to the sixth aspect, the gap is non-linearly changed by non-linearly moving the plate in the axial direction by the actuator and the control means in accordance with the temperature change of the viscous fluid detected by the temperature detecting means. This allows
It is possible to almost completely correct the damping force fluctuation due to the temperature change.

[0008]

Embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 shows Embodiment 1 of the present invention.
(S1-S1 in FIGS. 2 and 3) showing the rotary damper of FIG.
1 and FIG. 2 and FIG.
FIG. 3 is a cross-sectional view taken along lines S2 and S3-S3. As shown in these figures, the rotary damper according to the embodiment of the present invention is connected to a rotating shaft 1 fixed to a vehicle body and a bearing side on a lower arm. And an annular housing 2.

The rotating shaft 1 has small diameter portions 1a at both left and right ends.
1a and a central large-diameter portion 1b are formed in a cylindrical shape having a different outer diameter. The central large-diameter portion 1b is formed on a spline shaft 1c and has a spline hole 3a for the spline shaft 1c. Ring plate (Rotating shaft side plate)
3 and the annular spacer 4 are alternately mounted,
The plurality of annular plates 3 are fixed in the rotational direction with respect to the rotating shaft 1 while maintaining a predetermined interval in the axial direction, and the plurality of annular plates 3 and the entire annular spacer 4 are integrally formed in the axial direction with respect to the rotating shaft 1. It is assembled so that it can move relatively.

The annular housing 2 has shaft holes 2a, 2a
The two side walls 2c, 2d of a disk shape having a b and a cylindrical portion 2e as a cylindrical portion connecting the outer peripheral sides of the side walls 2c, 2d. Then, the left and right end face side walls 2
The shaft holes 2a and 2b of c and 2d are mounted on the left and right small-diameter portions 1a and 1a of the rotating shaft 1 via bearings 5 and 5, respectively. By contacting the left and right end surfaces of the large diameter portion 1b, the annular housing 2 is mounted so as to be rotatable relative to the rotary shaft 1 and prevented from moving in the axial direction.

In the openings of the axial holes 2a, 2b of the left and right side walls 2c, 2d of the annular housing 2, the inner peripheral surfaces of both the axial holes 2a, 2b and the left and right small diameter portions 1a,
1a are provided with sealing members 6 and 6, respectively, for hydraulically sealing between the outer peripheral surface of the rotating shaft 1 and the annular housing 2 by virtue of the two sealing members 6, 6. A chamber A is formed.

The outer cylindrical portion 2e is formed to have a different inner diameter with a ridge 2f formed at the center of the inner surface.
f is clamped between the left and right end side walls 2c, 2d, and the left and right opening edges of the outer peripheral cylindrical portion 2e are crimped to the outer peripheral surfaces of the left and right end side walls 2c, 2d during the assembling, respectively. , And the seal rings 2h and 2h provide a hydraulic seal between the left and right end side walls 2c and 2d.

The inner peripheral surface of the ridge 2f formed at the center of the inner surface of the outer peripheral cylindrical portion 2e is formed with a spline hole 2g, and the spline hole 2g is provided with the housing side annular spacer 7 and the spline hole 2g. An annular plate (annular housing side plate) 8 having a spline shaft-shaped outer peripheral shape that can be engaged is alternately inserted into the annular housing 2 in a state where the plurality of annular plates 8 are kept at a predetermined axial distance. , And the whole of the plurality of annular plates 8 and the annular spacers 7 are assembled to the annular housing 2 so as to be integrally movable relative to each other in the axial direction.

The rotating shaft annular plate 3 and the annular housing-side annular plate 8 are assembled alternately so that the plates 3 and 8 are alternately arranged in the annular housing 2 filled with the viscous fluid. As shown in detail in FIG. 6, the side surfaces have predetermined clearances δ ₁ and δ ₂ and face each other in the axial direction. Therefore, the clearances δ ₁ and δ ₂ are in a state of being filled with the viscous fluid.

An outer peripheral side annular set plate 9 and an inner peripheral side annular set are provided between the inner surface of the left end side wall 2c of the annular housing 2 and the outer periphery of the annular housing side annular plate 8 and the rotating shaft side annular spacer 4 facing the inner surface. Plate 1
A set spring 11 that constitutes a pressing member is interposed via the “0”. As shown in FIGS. 4 and 5, the set spring 11 alternately strikes the outer peripheral portion and the inner peripheral portion of the ring-shaped leaf spring material at four locations each, thereby forming the outer peripheral spring portion 11a and the inner peripheral spring portion. 11b are formed.

Right side wall 2 of annular housing 2
On the inner surface of d, an outer-peripheral-side temperature compensating member 12 that contacts the outer-peripheral-side annular set plate 15 and the inner-peripheral-side annular set plate 14 to receive the axial movement of the annular housing-side annular plate 8 and the rotating shaft-side annular plate 3; A temperature compensating mechanism including the inner peripheral temperature compensating member 13 is interposed. The outer peripheral side temperature compensating member 12 and the inner peripheral side temperature compensating member 13 are formed in a ring shape from materials having different axial linear expansion coefficients. Note that, in the embodiment of the present invention, the temperature compensation member 1 on the outer periphery side is more
2 is formed of a material having a larger linear expansion coefficient, and the outer peripheral side temperature compensating member 12 is formed of a material having a larger linear expansion coefficient than the linear expansion coefficient of the annular housing 2. The inner peripheral surface of the outer peripheral side temperature compensating member 12 and the outer peripheral surface of the inner peripheral side temperature compensating member 13 face each other in the axial direction at a low temperature with a predetermined clearance L. An engaging step (engaging portion) 12 in which the outer peripheral temperature compensating member 12 having a large expansion coefficient moves in the axial direction toward the annular housing side annular plate 8 and the rotating shaft side annular plate 3 together with the inner peripheral temperature compensating member 13.
a and 13a are formed. FIG. 1 shows the positional relationship of each member at the time of the minimum set temperature.

Next, the operation of the first embodiment of the invention will be described with reference to FIGS.
A description will be given based on FIG. (A) Minimum Set Temperature The rotary damper according to the embodiment of the present invention is configured as described above. Therefore, when the rotary damper is in the minimum set temperature state at the time of design (hereinafter, referred to as low temperature), FIG. As shown in FIG. 6, the clearances δ ₁ , δ ₂ between the left and right side surfaces of the annular plate 3 on each rotating shaft side and the annular plate 8 on the annular housing facing each are set to be the same. I have.

When the rotating shaft 1 and the annular housing 2 rotate relative to each other in this state, the two annular plates 3 adjacent to each other,
8 rotates relative to each other, and generates a viscous friction force when the viscous fluid filled in the clearances δ ₁ and δ ₂ between the annular plates 3 and 8 is forcibly moved at a flow rate according to the relative rotation speed. Then, a predetermined damping force is generated by viscous resistance due to the viscous friction force.

FIGS. 9 (a) and 9 (b) show variable characteristics of the generated torque (damping force) with respect to changes in the clearances δ ₁ and δ ₂ between the annular plates 3 and 8 respectively.
Figure 9 torque T solid line clearance [delta] ₁ side (b)
_1, the dotted line indicates the torque T ₂ generated by the clearance [delta] ₂ side, FIG. 9 (b) shows the total torque T of both torque T _1, T _2. That is, as shown in this figure,
Both clearances δ ₁ , δ between both annular plates 3, 8
₂ has the smallest generated damping force in the same state (at a low temperature), and the generated damping force changes in a direction in which the generated damping force increases regardless of which direction the clearances δ ₁ and δ ₂ change.

(B) At the intermediate set temperature When in the intermediate set temperature state at the time of design (hereinafter referred to as normal temperature), that is, when the temperature changes from the low temperature state to the temperature rising direction, the viscosity of the viscous fluid decreases. Therefore, the generated damping force changes in a direction of decreasing. That is, the generated damping force of the rotary damper changes in proportion to the viscosity of the viscous fluid as shown in the following equation (1). Damping force = (viscosity of viscous fluid × relative rotation speed × opposed area) ÷ gap ... (1) Since the viscosity of viscous fluid changes greatly depending on its temperature, the damping force also changes according to the temperature change. Therefore, the riding comfort of the vehicle fluctuates depending on the temperature.

However, in the first embodiment of the present invention,
Outer peripheral temperature compensation member 12 and inner peripheral temperature compensation member 13
By changing both clearances δ ₁ , δ ₂ (gap), it is possible to compensate for a decrease in the damping force generated due to a decrease in the viscosity of the viscous fluid due to a temperature change. The temperature compensation function will be described.

When the temperature of the viscous fluid is low,
As described above, both engaging portion step portions 12a and 13 formed between the outer peripheral side temperature compensating member 12 and the inner peripheral side temperature compensating member 13.
Since a predetermined clearance L is formed between the viscous fluid and the temperature of the viscous fluid, as shown in FIG.
When the outer peripheral temperature compensating member 12 and the inner peripheral temperature compensating member 13 having different linear expansion coefficients expand in the axial direction, the annular housing side annular plate 8 and the rotating shaft side annular plate 3 are expanded.
Was pressed and moved in the axial direction (left direction), thereby, a clearance [delta] ₁ between only the linear expansion coefficient difference both the annular plates 8,3 each other, to reduce one clearance [delta] ₂ of the [delta] _2, The viscous resistance due to the relative rotation of the two annular plates 8 and 3 increases, and the decrease in the damping force due to the increase in the temperature of the viscous fluid is automatically corrected.

When the viscous fluid reaches the intermediate set temperature at the time of design, as shown in FIG. 7, the predetermined clearance L is lost and the two engaging steps 12a and 13a are engaged with each other. Is set.

(C) At the time of the highest set temperature When the viscous fluid is in the highest set temperature state at the time of design (hereinafter, referred to as a high temperature), that is, when the temperature of the viscous fluid further increases from the above-mentioned normal temperature state, the viscous fluid Is further reduced, so that the generated damping force decreases.

However, when the viscous fluid reaches the intermediate set temperature at the time of design, the predetermined clearance L is lost, and the two engaging steps 12a and 13a are in the state of being engaged with each other. When the temperature of the viscous fluid further rises from the state, the outer peripheral temperature compensating member 12 having the larger linear expansion coefficient is moved along the inner peripheral temperature compensating member 13 having the smaller linear expansion coefficient in the axial direction (left direction in the drawing). to move to the axial movement amount of the low temperature-side temperature compensating member 13 is increased compared with the case where a predetermined clearance L is present, therefore, when low temperature - normal temperature reduction rate of clearance [delta] ₂ is to the temperature change Is lower than the case when the temperature changes. That is, as shown in FIG. 10, the variable characteristics of the clearances δ ₁ , δ ₂ with respect to the temperature change can be made to be non-linear characteristics in which the rate of change changes at the room temperature.

As described above, since the variable characteristics of the clearances δ ₁ and δ ₂ with respect to the temperature change can be made to be non-linear characteristics, the damping force fluctuation correction characteristics can be changed with respect to the viscous fluid which changes non-linearly with the temperature change. Viscosity (damping force) change characteristics can be approximated.

As described above, according to the rotary damper of the embodiment of the present invention, the variable characteristic of the clearance δ ₂ with respect to the temperature change is a non-linear characteristic whose change rate changes at normal temperature. Therefore, it is possible to obtain an effect that a correction corresponding to a change in damping force based on a change in temperature becomes possible.

Next, another embodiment of the present invention will be described. In the description of the other embodiments of the present invention, the same components as those in the first embodiment of the present invention are omitted from the drawings, or the same reference numerals are given, and the description is omitted, and only the differences are described. explain.

(Embodiment 2) The embodiment 2 of the present invention is different from the embodiment 1 in that the inner peripheral surface of the outer peripheral side temperature compensating member 12 and the outer peripheral surface of the inner peripheral side temperature compensating member 13 are different from each other. The engagement step portions 12a and 13a are formed only at one position, whereas the first engagement step portions 12a and 13a and the second engagement step Part 12
This shows an example in which b and 13b are formed.

At the time of the minimum set temperature shown in FIG. 11, predetermined clearances L ₁ and L ₂ are provided in the first engagement step portions 12a and 13a and the second engagement step portions 12b and 13b. with each being formed, the first engaging stepped portion 12a, than the clearance L ₁ of the 13a, the second engaging stepped portion 12b, by the direction of 13b clearance L ₂ is set to be larger, the viscous fluid When the temperature rises from the minimum set temperature state (of FIG. 11) and reaches the intermediate set low temperature, as shown in FIG.
Engagement step 12a, 13a clearance L ₁ is zero, and further when the temperature becomes normal temperature to rise, as shown in FIG. 11 for the second engaging stepped portion 12b, 13b of the clearance L _{2 is} also set to be 0.

Therefore, in the rotary damper according to the second embodiment of the present invention, as shown in FIG. 12, the change characteristic of the viscosity δ ₂ of the viscous fluid and the change characteristic of the clearance δ ₂ with respect to the temperature change. To
The first engagement step 12a, 13a and the second engagement step 12b, 1
In the intermediate setting where the clearances L ₁ and L _{2 of FIG.} 3b become 0, the non-linear characteristic can be obtained in which the rate of change changes with two inflection points at low temperature and normal temperature. The correction characteristic can be made closer to the viscosity (damping force) change characteristic of a viscous fluid that changes nonlinearly with a temperature change.

(Third Embodiment) A rotary damper according to a third embodiment of the present invention differs from the first embodiment in the structure of the temperature compensating mechanism. The configuration is almost the same as that of the first embodiment.

As shown in FIGS. 13 to 16, the rotary damper according to the third embodiment of the present invention has an outer peripheral annular groove 2j and an inner peripheral annular groove 2k on the inner surface of the right end side wall 2d of the annular housing 2. Are formed, and both annular grooves 2 are formed.
14, the annular housing-side annular plate 8 and the rotating shaft-side annular plate 8 abut on the annular housing-side annular spacer 7 and the inner peripheral-side annular set plate 14 at the set intermediate temperature, as shown in detail in FIG. A temperature compensating mechanism including a low temperature side temperature compensating member 16 and a high temperature side temperature compensating member 17 for receiving the axial movement of the plate 3 is interposed. The low-temperature-side temperature compensating member 16 and the high-temperature-side temperature compensating member 17 are formed in a ring shape using materials having different linear expansion coefficients in the radial direction. A low-temperature side cam surface 18 is formed between the side annular groove 2j and the inner peripheral side wall 2m to convert a change in radial dimensional shrinkage of the low-temperature side temperature compensating member 16 due to a temperature drop into an axial movement (leftward movement in the figure). A change in the radial dimensional expansion of the high temperature side temperature compensating member 17 due to a temperature rise is caused between the outer peripheral edge of the right side wall 2d side of the high temperature side temperature compensating member 17 and the outer peripheral side wall 2n of the inner peripheral side annular groove 2k. A high-temperature side cam surface 19 that converts the movement into a directional movement (a leftward movement in the drawing) is formed.

As shown in FIG. 14, the annular housing side annular spacer 7 and the inner peripheral side annular set plate 14 are connected to the low temperature side temperature compensating member 16 and the high temperature side temperature compensating member 17 at the intermediate set temperature. At the same time as being abutted and supported, it is in a state where it abuts against the right side wall 2d and is prevented from moving rightward in the drawing. In this state, the clearances δ ₁ and δ ₂ between the two annular plates 8 and 3 are set such that the clearance δ ₂ on the right side is narrower than the clearance δ ₁ on the left side in the drawing.

Next, the operation of the third embodiment of the present invention will be described with reference to FIGS. (A) Intermediate Set Temperature When the temperature of the viscous fluid is at the set intermediate temperature (25 ° C.) (hereinafter referred to as normal temperature), as described above, the low temperature side temperature compensating member 16 and the high temperature side temperature compensating member 17 The annular housing-side annular plate 8 and the rotating shaft-side annular plate 3 are in contact with the annular housing-side annular spacer 7 and the inner circumferential-side annular set plate 14 to receive the axial movement to the right in the drawing, respectively.

In this state, as shown in FIG. 14, the clearances δ ₁ and δ ₂ between the two annular plates 8 and ₃ are closer to the clearance δ _{2 on} the right side than the clearance δ ₁ on the left side in the drawing. Is set to a narrowed state.

In this state, when the rotating shaft 1 and the annular housing 2 rotate relative to each other, the two annular plates 3 adjacent to each other,
8 rotates relative to each other, and generates a viscous friction force when the viscous fluid filled in the clearances δ ₁ and δ ₂ between the annular plates 3 and 8 is forcibly moved at a flow rate according to the relative rotation speed. Then, a predetermined damping force is generated by viscous resistance due to the viscous friction force.

As shown in FIG. 9, when the clearances δ ₁ and δ ₂ between the annular plates 3 and 8 are the same (at a low temperature), the damping force generated by the rotary damper is the smallest, and Regardless of which direction δ ₁ or δ ₂ changes, it changes in the direction in which the generated damping force increases.

At this normal temperature, the clearance δ _{1 on} the left side is set to be smaller than the clearance δ ₂ on the right side of the drawing, so that both clearances δ ₁ between the annular plates 3 and 8 are set. , Δ ₂ generate a higher damping force than in the same state.

(B) Low Temperature When the viscous fluid is in a low temperature set temperature state at the time of design (hereinafter, referred to as low temperature), that is, when the temperature of the viscous fluid changes from the above-mentioned normal temperature state to a direction in which the temperature of the viscous fluid decreases, Since the viscosity decreases, the generated damping force changes in a direction of decreasing.

However, when the temperature decreases, the radial dimension of the low temperature side temperature assurance member 16 on the outer periphery changes in the contracting direction. However, the radial contraction is prevented by the presence of the low temperature side cam surface 18. The change in the radial dimensional shrinkage is converted into the axial movement, and as shown in FIG. 15, the annular housing side tubular plate 8 is pressed and moved to the left in the drawing, whereby the clearance δ between the two annular plates 8 and 3 is increased. _1, [delta] of the _two, for changing the direction Ru reduce the left clearance [delta] ₁ (increasing the right clearance [delta] _2), viscous resistance is reduced due to the relative rotation of both the annular plates 8,3, the viscous fluid The increase in the damping force due to the temperature decrease is automatically corrected by the change rate according to the value of the linear expansion coefficient of the low temperature side temperature compensating member 18.

When the temperature of the viscous fluid is set at the low temperature set at the time of design, as shown in FIG. 15, the values of the clearances δ ₁ and δ ₂ are set to be the same, and the generated damping force is the lowest. State.

(B) High Temperature When the viscous fluid is in the maximum set temperature state at the time of design (hereinafter, referred to as high temperature), that is, when the temperature of the viscous fluid changes from the above-mentioned normal temperature state to the direction in which the temperature of the viscous fluid rises, Since the viscosity increases, the generated damping force changes in a direction to increase.

However, when the temperature rises, the radial dimension of the high temperature side temperature assurance member 17 on the inner circumference changes in the expanding direction, but the radial expansion is prevented by the presence of the high temperature side cam surface 19. , The change in the radial dimensional expansion is converted into the axial movement, and as shown in FIG. 16, the rotating shaft side tubular plate 3 is pressed and moved to the left in the drawing, whereby the clearance between the two annular plates 8 and 3 is increased. δ
_1, [delta] of the _two, for changing the direction Ru further reduce the right clearance [delta] ₂ (further increase the clearance [delta] ₁ on the left), the viscous resistance is further increased due to the relative rotation of both the annular plates 8,3 In addition, the decrease in the damping force due to the rise in the temperature of the viscous fluid is automatically corrected by the change rate according to the value of the linear expansion coefficient of the high temperature side temperature compensating member 19.

[0045] Then, based on the linear expansion coefficient and radial dimensional difference between the low-temperature side temperature compensating member 16 and the upper temperature compensation member 17, as shown in FIG. 17, both the clearance [delta] _1,
The variable characteristic of [delta] ₂ by the normal temperature as a boundary can be non-linear characteristics in which the rate of change changes. FIG. 18 shows a damping force characteristic diagram with respect to a temperature change. The solid line shows the characteristic of the third embodiment of the present invention, and the dotted line shows the conventional characteristic without correction.

As described above, in the rotary damper according to the third embodiment of the present invention, the variable characteristics of the clearances δ ₁ and δ ₂ with respect to the temperature change can be made non-linear characteristics. Since the viscosity (damping force) change characteristic of the viscous fluid that changes non-linearly with respect to the temperature change can be approximated, it is possible to obtain an effect that the correction corresponding to the damping force change based on the temperature change can be performed.

Further, since both temperature compensating members 16 and 17 are ring-shaped, they can be easily processed, can easily obtain accuracy, and
Even if it is thin in the axial direction, the amount of dimensional change in the radial direction based on the temperature change can be amplified to a large amount of movement in the axial direction, so that an effect of enabling downsizing in the axial direction can be obtained.

Further, since the axial movement amounts of the two temperature compensating members 16 and 17 can be used for the damping force correction, the amount of correction can be made large and the respective linear expansion coefficients of the two temperature compensating members 16 and 17 can be changed. And / or both cam surfaces 1
By changing the inclination angles of 8 and 19, the correction amounts on the low temperature side and the high temperature side can be set independently and freely, so that the damping force change characteristic with respect to the temperature change can be easily and freely tuned.

(Embodiment 4) In Embodiment 4 of the present invention, both the cam surfaces 18 and 19 are formed in a planar shape in Embodiment 3 of the present invention, as shown in FIG. Fig. 1 shows an example in which a curved surface is formed.

That is, in the fourth embodiment of the present invention, the low temperature side temperature compensating member 16 and the high temperature side temperature compensating member 17 are curved along the curved surfaces of the cam surfaces 18 and 19 on the low temperature side and the high temperature side. 20 in the axial direction.
As shown in the figure, both clearances δ ₁ , δ
_{2 The} change (damping force correction) is performed in a curved line,
It becomes possible to almost completely correct the fluctuation of the damping force due to the temperature change. By forming the cam surface as a curved surface, both clearances δ ₁ and δ ₂ (damping force correction) with respect to temperature change are changed in a curved line. Therefore, even if only one temperature compensating member is used, the damping force fluctuation with respect to temperature change can be obtained. Can be almost completely corrected.

(Fifth Embodiment) A rotary damper according to a fifth embodiment of the present invention is provided with a temperature compensating mechanism, as shown in FIG. 21, by a temperature sensor (temperature detecting means) 21 for detecting the temperature of a viscous fluid. A controller (control means) 22 for calculating an amount by which the annular housing-side annular plate 8 is relatively non-linearly moved in the axial direction in accordance with a temperature change of the viscous fluid detected by the temperature sensor 21;
A driving unit (control means) 23 for outputting a driving signal based on a command from the controller, and a relative non-linear movement of the annular housing-side annular plate 8 in the axial direction based on the driving signal from the driving unit 23. , Both clearances δ ₁ ,
and a piezoelectric element (actuator) 24 that changes δ ₂ nonlinearly.

In the rotary damper according to the fifth embodiment of the present invention, the annular housing-side annular plate 8 is electrically non-linearly moved in the axial direction in accordance with the temperature change of the viscous fluid detected by the temperature sensor 21. Thereby, both clearances δ ₁ and δ ₂ can be changed non-linearly, so that it is possible to almost completely correct the fluctuation of the damping force due to the temperature change.

Although the embodiments of the present invention have been described with reference to the drawings, the specific configuration is not limited to the embodiments of the present invention, and design changes and the like may be made without departing from the scope of the present invention. The present invention is also included in the present invention.

For example, in the embodiment of the present invention, the case where the lower arm of the vehicle is provided on the rotation bearing portion or the like is taken as an example. However, when the relative movement between arbitrary members is attenuated in the rotational direction, The present invention can be applied.

In the embodiment of the present invention, a leaf spring is used as the pressing means, but other elastic members such as a coil spring, rubber, and an air spring can be used.

In the third embodiment of the present invention, the case where the low-temperature-side temperature compensating member is provided on the outer peripheral side and the high-temperature-side temperature compensating member is provided on the inner peripheral side may be reversed.
The cam surfaces are formed on the outer peripheral side wall side of the outer peripheral side annular groove 2j and the inner peripheral side wall side of the inner peripheral side annular groove 2k.

[0057]

As described above, in the rotary damper according to the first aspect of the present invention, as described above, the housing-side plate and the rotating shaft-side plate rotate with respect to the housing cylinder or the rotating shaft, respectively. At least one of the housing-side plate and the rotating shaft-side plate is provided so as to be capable of transmission, and is provided so as to be movable in the axial direction, and one end face of the plate and one end face of the housing are provided. A pressing means is provided between the side wall and the other end side wall to press and urge the plate toward the other end side wall, and the plate is relatively non-linearly moved in the axial direction with respect to a temperature change on the other end side wall of the housing. With the configuration provided with a temperature compensation mechanism that changes the gap nonlinearly, the temperature compensation mechanism By moving the plates in a non-linear manner relative to each other in the axial direction, the gap between the two plates is changed in a non-linear manner, so that the viscous resistance due to the relative rotation of the two plates is changed. This makes it possible to perform a correction corresponding to a typical change in damping force. According to a second aspect of the present invention, in the rotary damper according to the first aspect, the outer peripheral side temperature compensating member and the inner peripheral side temperature compensating member constituting the temperature compensating mechanism are made of materials having mutually different linear expansion coefficients in the axial direction. The temperature compensating member and the inner peripheral side temperature compensating member face each other in the axial direction with a predetermined clearance at a low temperature, and the temperature compensating member has a larger linear expansion coefficient because the clearance is buried due to a temperature rise. In this configuration, the engagement portion for moving the temperature compensating member in the plate direction is formed, so that the rate of change of the damping force correction characteristic with respect to the temperature change at the time when the clearance is filled can be changed. Therefore, the damping force correction for the temperature change can be performed non-linearly, and accordingly, the correction corresponding to the non-linear damping force change due to the temperature change of the viscous fluid can be performed. Effect is obtained that it becomes capacity. Further, since the temperature compensating mechanism has only a mechanical configuration, the configuration is simple and the cost can be reduced. According to a third aspect of the present invention, there is provided the rotary damper according to the second aspect, wherein the plurality of engaging portions are formed in a stepwise manner, and the clearance of each of the engaging portions is set to gradually increase as going in the plate direction. As a result, the rate of decrease of the gap with respect to the temperature rise can be changed in a direction to decrease in two steps, so that it is possible to perform a correction that can further cope with a nonlinear damping force change due to a temperature change of the viscous fluid. Is obtained. Claim 4
In the rotary damper described in claim 1, the low temperature side temperature compensating member and the high temperature side temperature compensating member constituting the temperature compensating mechanism are formed in a ring shape from materials having different linear expansion coefficients in a radial direction. A low-temperature cam surface for converting a change in radial dimensional shrinkage of the low-temperature temperature compensating member due to a temperature drop into an axial movement is formed between the inner peripheral edge of the member at the end surface side wall and the end surface side wall. Between the outer peripheral edge of the end face side wall and the end face side wall, a high temperature side cam surface for converting a change in radial dimensional expansion of the high temperature side temperature compensating member due to a temperature rise into an axial movement is formed. Since the correction change rate of the damping force is different between the low temperature side temperature change and the high temperature side change of the viscous fluid, the damping force correction for the temperature change can be performed in a non-linear manner. Effect that permits correction corresponding to non-linear damping force change due to the change. In addition, since the temperature compensation mechanism has only a mechanical configuration, the configuration is simple, and since both temperature compensation members are ring-shaped, processing is easy, accuracy is easily obtained, and the temperature compensation mechanism is thin in the axial direction. Since the radial dimensional change amount due to the temperature change can also be amplified to a large axial movement amount, the effect that the axial direction can be made compact can be obtained. In addition, the amount of axial movement of the two temperature compensating members can be used for damping force correction, so that the amount of correction can be increased, and each coefficient of linear expansion of the two temperature compensating members can be changed, and / or By changing the inclination angle, the correction amount on the low temperature side and the high temperature side can be set independently and freely, so that the damping force change characteristic with respect to the temperature change can be easily and freely tuned. Is obtained. According to a fifth aspect of the present invention, in the rotary damper according to the fourth aspect, the low-temperature-side cam surface and the high-temperature-side cam surface are formed as curved surfaces, so that a damping force correction for a temperature change is performed in a curved line. Accordingly, an effect is obtained that the fluctuation of the damping force with respect to the temperature change can be almost completely corrected. According to a sixth aspect of the present invention, there is provided the rotary damper according to the first aspect, further comprising a temperature detecting unit configured to detect a temperature of the viscous fluid, wherein the temperature compensating mechanism is configured to respond to a temperature change of the viscous fluid detected by the temperature detecting unit. By configuring the actuator and the control unit to nonlinearly change the gap by nonlinearly moving the plate relatively in the axial direction, the damping force correction for the temperature change is performed in a curved line. An effect is obtained that the damping force fluctuation can be almost completely corrected.

[Brief description of the drawings]

FIG. 1 is an overall cross-sectional view showing a state at a low temperature in a rotary damper according to a first embodiment of the present invention (S1--FIG. 2 and FIG. 3);
FIG. 3 is a cross-sectional view taken along line S1.

FIG. 2 is a sectional view taken along line S2-S2 in FIG.

FIG. 3 is a sectional view taken along line S3-S3 in FIG.

FIG. 4 is a plan view showing a set spring.

FIG. 5 is a sectional view taken along line S5-S5 in FIG. 4;

FIG. 6 is an enlarged sectional view of a main part showing details of a temperature compensating member at a low temperature according to the first embodiment of the invention;

FIG. 7 is an enlarged sectional view of a main part showing details of a temperature compensating member at room temperature according to the first embodiment of the invention;

FIG. 8 is a main part enlarged sectional view showing details of a temperature compensating member at the time of high temperature according to the first embodiment of the invention;

FIG. 9 is a variable characteristic diagram of generated torque (damping force) with respect to a change in both clearances between the rotary shaft side annular plate and the annular housing side annular plate according to the first embodiment of the present invention.

FIG. 10 is a diagram illustrating a viscosity change characteristic and a clearance variable characteristic of a viscous fluid with respect to a temperature change according to the first embodiment of the invention;

FIG. 11 is a fragmentary cross-sectional view showing a structure and an operating state of a temperature compensation mechanism in a rotary damper according to a second embodiment of the present invention.

FIG. 12 is a diagram illustrating a viscosity change characteristic and a clearance variable characteristic of a viscous fluid with respect to a temperature change according to the second embodiment of the present invention;

FIG. 13 is an overall cross-sectional view showing a state of the rotary damper according to the third embodiment of the present invention at normal temperature (S1 in FIGS. 2 and 3);
FIG. 3 is a cross-sectional view taken along line -S1.

FIG. 14 is a main part enlarged sectional view showing details of a temperature compensating member at room temperature according to Embodiment 3 of the present invention.

FIG. 15 is an enlarged sectional view of a main part showing details of a temperature compensating member at a low temperature according to a third embodiment of the invention;

FIG. 16 is an enlarged cross-sectional view of a main part showing details of a temperature compensating member at a high temperature according to a third embodiment of the invention;

FIG. 17 is a diagram illustrating a viscosity change characteristic and a clearance variable characteristic of a viscous fluid with respect to a temperature change according to the third embodiment of the present invention.

FIG. 18 is a damping force characteristic diagram with respect to a temperature change according to the third embodiment of the present invention.

FIG. 19 is an enlarged sectional view of a main part showing details of a temperature compensating member at room temperature according to Embodiment 4 of the present invention.

FIG. 20 is a diagram illustrating a clearance variable characteristic with respect to a temperature change according to the fourth embodiment of the present invention;

FIG. 21 is an overall cross-sectional view showing a state at a low temperature in a rotary damper according to a fifth embodiment of the invention (S1--FIG. 2 and FIG. 3);
FIG. 3 is a cross-sectional view taken along line S1.

[Explanation of symbols]

A Closed chamber 1 Rotary shaft 2 Annular housing (housing) 2c Left end side wall 2d Right end side wall 2e Cylindrical part (cylindrical part) 3 Rotary shaft side annular plate (Rotary shaft side plate) 8 Annular housing side annular plate (Housing side plate) 11 Set Spring (Pressing Means) 12 Outer Peripheral Temperature Compensation Member 12a Engagement Step (Engagement Part) 12b First Engagement Step (Engagement Part) 13 Inner Perimeter Temperature Compensation Member 13a Engagement Step (Engagement) 13b 2nd engaging step (engaging part) 16 low temperature side temperature compensating member 17 high temperature side temperature compensating member 21 temperature sensor (temperature detecting means, temperature compensating mechanism) 22 controller (controlling means, temperature compensating mechanism) 23 driving Unit (control means, temperature compensation mechanism) 23 Piezoelectric element (actuator, temperature compensation mechanism)

Claims (6)

[Claims] 1. A housing in which outer peripheral sides of both side walls are connected by a cylindrical portion, a rotating shaft provided in the housing so as to be rotatable relative to the housing and prevented from moving in the axial direction, A sealed chamber filled with a viscous fluid is formed between the rotating shaft and the housing. In the sealed chamber, the inner periphery of the housing cylindrical portion and the outer periphery of the rotating shaft are provided alternately in the axial direction, and the side surfaces of both are provided. A housing side plate and a rotating shaft side plate facing each other with a predetermined gap, wherein the housing side plate and the rotating shaft side plate are provided so as to be capable of transmitting rotation to the housing cylinder or the rotating shaft, respectively. At least one of the housing-side plate and the rotating shaft-side plate is provided so as to be movable in the axial direction. A pressing means is provided between one end face of the housing and one end face side wall of the housing to press and bias the plate in the direction of the other end face side wall, and the other end face side wall of the housing is provided with a plate against temperature change. A rotary damper, comprising: a temperature compensating mechanism that non-linearly changes the gap by relatively moving non-linearly in the axial direction. 2. The housing side plate and the rotating shaft side plate are provided so as to be capable of transmitting rotation to the housing cylinder portion or the rotating shaft and moving in the axial direction, respectively. Pressing means for pressing and urging the plate in the direction of the other end face side wall is provided between one end face of the housing and one end face side wall of the housing, and the housing side plate and the rotating means are provided on the other end face side wall of the housing. A temperature compensating mechanism comprising an outer peripheral temperature compensating member and an inner peripheral temperature compensating member which abuts on the other end surfaces of the shaft side plate to receive the axial movement, respectively, is interposed, and the two temperature compensating mechanisms are configured. The outer-peripheral-side temperature compensating member and the inner-peripheral-side temperature compensating member are made of materials having different linear expansion coefficients in the axial direction. The temperature compensating member and the inner peripheral side temperature compensating member have a predetermined clearance at a low temperature and face in the axial direction, and the temperature compensating member has a larger linear expansion coefficient because the clearance is buried due to a temperature rise. 2. The rotary damper according to claim 1, wherein an engagement portion for moving the temperature compensating member in a plate direction is formed. 3. The rotary according to claim 2, wherein a plurality of said engaging portions are formed in a stepwise manner, and a clearance of each of said engaging portions is set so as to gradually increase as going in a plate direction. damper. 4. The housing-side plate and the rotating shaft-side plate are provided so as to be capable of transmitting rotation to the housing cylinder portion or the rotating shaft and moving in the axial direction, respectively. Pressing means for pressing and urging the plate in the direction of the other end face side wall is provided between one end face of the housing and one end face side wall of the housing, and the other end face side wall of the housing is annular at the set intermediate temperature. A temperature compensating mechanism comprising a low temperature side temperature compensating member and a high temperature side temperature compensating member which abuts on the other end surfaces of the housing side plate and the rotating shaft side plate to receive axial movement, respectively, is interposed. The temperature compensating member and the high temperature side temperature compensating member are formed in a ring shape from materials having different linear expansion coefficients in the radial direction. A low-temperature cam surface is formed between the inner peripheral edge of the low-temperature temperature compensating member and the end surface of the low-temperature temperature compensating member to convert a change in radial dimensional shrinkage of the low-temperature temperature compensating member due to a temperature drop into an axial movement. A high-temperature side cam surface is formed between the outer peripheral edge of the high-temperature side temperature compensating member and the end surface side wall to convert a change in radial dimensional expansion of the high-temperature side temperature compensating member due to a temperature rise into an axial movement. The rotary damper according to claim 1, wherein: 5. The rotary damper according to claim 4, wherein said low-temperature side cam surface and said high-temperature side cam surface are formed as curved surfaces. 6. A temperature detecting means for detecting a temperature of the viscous fluid, wherein the temperature compensating mechanism non-linearly moves the plate in an axial direction according to a temperature change of the viscous fluid detected by the temperature detecting means. 2. The rotary damper according to claim 1, comprising an actuator and control means for changing the gap in a non-linear manner by moving the gap.