JPH04203630A - Rotary damper - Google Patents

Abstract

PURPOSE:To secure such a damping torque characteristic that is more than that of a telescopic type damper by forming a clearance between the inner circumference of a casing and the outer circumference of a side plate, and molding this casing with deformable wall thickness, in a rotary damper which is interposed between a body and an axle of a vehicle. CONSTITUTION:Each of separator blocks 7A, 7B is attached tight to the inner part of a casing 2, and each of oil chambers A, B is partitioned off in space with a vane body part 5. For example, at time of operation at an expansion side where an upper arm 22 rotates its tip downward, the oil chamber A is contracted by relative rotation of a vane 4 of the casing 2, while the oil chamber B is expanded the other way, and a part of working oil in the oil chamber A flows into the oil chamber B through a rocking clearance (a) between the vane body part 5 and the casing 2, a peripheral clearance (b) between two side plates 6A and 6B, and other clearances (c) and (d), generating the expansion side damping force with flow resistance. In addition, up pressure in the oil chamber A acts on a relief valve 11 at a port 8A, pushing this relief valve 11 open at more than the specified value, and the working oil flows into the oil chamber B from the oil chamber A. As for a pressure receiving area, it is small in the port 8A and the expansion side damping force grows larger. In this connection, wall thickness in the casing 2 is made deformable with hydraulic pressure.

Description

[Detailed description of the invention] [Industrial application field] The present invention is installed between a vehicle body and an axle.

The present invention relates to a rotary damper that improves riding comfort and handling by attenuating energy such as vibrations from the road surface.

(Prior Art) When a rotary damper is installed on a vehicle, the rotary damper is interposed between the vehicle body and the axle to attenuate energy such as vibrations from the road surface.

For example, as shown in FIG. 7, the casing 2 of the rotary damper R is fixed to the vehicle body 20, and one end of the arm 22 is fixed to the swing shaft 1 of the rotary damper R with a spline or the like.
The other end of the arm 22 is pivotally connected to a bracket 23 provided on the axle 21 via a shaft 24, and when the arm 22 swings due to vibrations from the road surface, the swing shaft l rotates clockwise or counterclockwise. At this time, a vane interlocking with a swing shaft l provided in the casing 2 rotates to damp vibration energy.

(Problem to be solved by the invention) A conventional rotary damper has a cylinder, a pair of separate blocks provided in the cylinder, and side plates provided at both ends of the vane. The damping force is generated by the flow resistance of oil flowing between the side plate and the inner circumference of the casing, between each side plate and the side of the separate block, and between each side plate and the inner circumference of the casing, so it is equivalent to a general cylindrical damper. It is difficult to obtain a riding-type damping force characteristic, and in addition, it is also difficult to add a damping force adjustment mechanism due to the structure of the rotary damper.

Furthermore, the damping force depends on the passage resistance due to the gap between the vane and the casing and the gap between the side plate and the separate block, so if the viscosity of the hydraulic oil changes with temperature, the generated damping force will change, and the amount of change will change. is the length of the gap, in other words, the length of the oil passage is larger than the amount of change of the cylindrical damper.

Therefore, a first object of the present invention is to provide a rotary damper which can obtain damping force characteristics equal to or better than that of a cylindrical damper and which can also adjust the damping force.

Another object of the present invention is to provide a rotary damper that can reduce the amount of change in damping force characteristics even if the viscosity of the hydraulic oil changes depending on the temperature or the viscosity of the hydraulic oil.

(Means for Solving the Problem) In order to achieve the above first object, the first configuration of the present invention includes a casing, a pair of separate blocks provided on the inner periphery of the casing, and a pair of separate blocks provided inside the casing. A swing shaft having a vane rotatably inserted into the casing, a side plate provided at the end of the vane, a plurality of oil chambers defined in the casing by the separate block and the vanes, and the inner periphery of the casing and the vanes. between the outer periphery of the casing, the inner periphery of the casing and the outer periphery of the side plate, between the side plate side surface and the separate block side surface, and between the swing shaft and the separate block. The casing is formed with a deformable wall thickness or material, and the casing is expanded outward by applying internal pressure. The feature is that the gap between the side plate and the side plate can be varied according to the internal pressure.

Furthermore, in order to achieve the other object described above, a second configuration of the present invention includes a casing, a pair of separate blocks provided on the inner periphery of the casing, and a vane rotatably inserted into the casing. A plurality of oil chambers are defined in the casing by the swing shaft, a side plate provided at the end of the vane, a separate block and the vane, and between the inner periphery of the casing and the outer periphery of the vane. Damping force generation gaps are provided between the outer periphery of the side plate, between the side plate side surface and the separate block side surface, and between the swing shaft and the separate block to communicate the oil chambers with each other, and the oil Equipped with a relief valve installed in the passage that connects the chambers, the Severade block can be shaken! ! It is characterized by being molded from a material with a larger coefficient of thermal expansion than the shaft and side plates, so that the gap between the swing shaft and the separate block and the gap between the side plate and the separate block can be made variable depending on temperature changes. That is.

(Function) When the vane rotates, the oil in one oil chamber shrinks through the gap between the outer circumference of the vane, the gap between the outer circumference of each side plate and the inner circumference of the casing, and the gap between the side plate side surface and the separate block. A damping force is generated due to flow resistance flowing through each gap.

In this case, the gap around the outer circumference of the side plate becomes smaller as the vane rotates, and the damping force increases.

Furthermore, if the space between the side plate and the separate block and between the separate block and the swing shaft is made of a material with a large coefficient of thermal expansion, the separate block may swing as the temperature changes. It expands or contracts more than the dynamic shaft and the side plate to change the gap due to temperature, thereby reducing the amount of change in damping force caused by changes in the viscosity of the hydraulic oil due to temperature changes.

(Example) Embodiments of the present invention will be described below based on the drawings.

In Fig. 1, reference numeral 1 denotes a hollow swing shaft whose one end is inserted concentrically inside a casing 2, and the outer periphery of a rotating shaft IO that integrally forms a part of the swing shaft l. As shown in FIGS. 2 and 3, the vane 4 is integrally constructed.

The vane 4 has a plate-shaped vane main body 5 whose both ends are adjacent to the inner periphery of the casing 2 through a gap a for generating damping force, and a pair of disk-shaped vanes integrally fixed to both ends of the vane main body 5. It consists of side plates 5A and 6B, and a gap for generating a damping force is formed between the outer periphery of each side plate 6A and 6B and the inner periphery of the casing 2.

The rotating shaft 10 is rotatably supported by the casing 2 via the fish 9.

The casing 2 is hermetically sealed by a cover 15, and the swing shaft 1 freely swings through the cover 15 via the bush 3 and projects to the outside of the casing 2.

As shown in FIGS. 2 and 4, a pair of separate blocks 7A and 7B are fixedly attached to the inside of the casing 2 at a distance of 180", and the inside of the casing 2 is formed by the separate blocks 7A and 7B and the vane body 5. Vane body part 5
Two pairs of oil chambers A and B are defined on both sides of the oil chamber.

A gap between the outer periphery of the rotating shaft 10 and the inner periphery of the separate blocks 7A, 7B and between the outer surface of the side plates 6A, 6B and the outer surface of the separate blocks 7A, 7B communicates with each oil chamber A, B. Gaps c and d are formed for generating damping force.

Boats 8A and 8B are opened in one side plate 6B through these oil chambers A and B, respectively.

The boats 8A and 8B penetrate the side plate 6B and open on the opposite side, and a valve consisting of a relief valve 11 and a check valve 12 is provided between this opening and a passage 14 formed in the casing 2 outside the opening. V is provided.

The relief valve 11 and check valve 12 are connected to the side plate 6B.
The relief valve 11 is composed of a disk-shaped valve that is slidably fitted to a rotating shaft 10, which is a swinging shaft extending outward from the 100, and the relief valve 11 is oriented toward the side plate 6 so as to close the boats 8A and 8B by a leaf spring 13. energized.

Furthermore, the check valve 12 only allows oil to flow in the opposite direction without resistance.

In addition, the pressure receiving part lIA facing the port -8A of the relief valve 11
is formed in an annular groove, and is turned to the outside of the pressure receiving part 11B facing the boat 8B.

Therefore, the two oil chambers A communicate with each other via the pressure receiving part 11^, and the other two oil chambers B also communicate with each other via the pressure receiving part 11B.

In addition, the pressure receiving parts 11A and 118 have through holes 19A and +91
1 to the annular valve portion 12 of the check valve 12 on its outer side.
A, connected to 12B.

Each valve part 12A, 12B of the check valve 12 is a pressure receiving part 1.
1A, IIB closes when the pressure is higher than passage 14, and opens when the opposite is true.

Incidentally, when the relief valve 11 is opened, the relief valve 11 and the check valve 12 move together along the swinging portion l.

The passage 14 communicates with an oil reservoir chamber 17 formed inside the swing shaft 1 via a hollow rotating shaft 1O.

The oil sump chamber 17 is used for oil chambers A and B and the passage 14 due to temperature changes.
A gas chamber 17a filled with compressed air via a free piston 16 is provided inside.

Next, the basic operation will be explained.

For example, as shown in FIG.
Used to support the axle 21 relative to 0.

That is, for example, a swing shaft 1 is connected to the vehicle body 20, and the casing 2 is connected to the opposite end of the upper arm 22 that communicates with the axle 21.

In this case, during the overwhelming operation in which the upper arm 22 rotates its tip upward, the oil chamber B contracts and the oil chamber A expands due to the relative rotation of the casing 2 and vane 4.

As a result, a part of the hydraulic oil in the oil chamber B flows through the swing gap a between the vane body 5 and the casing 2 and the side plates 6^, 6.
The oil flows into the oil chamber A through the outer peripheral gap B and another gap C1d, and the flow resistance at that time generates an overwhelming damping force.

Also, the increased pressure in the oil chamber B acts on the relief valve 11 via the boat 8B, and when this pressure rises above a certain level, the relief valve 11 is pushed open, and the hydraulic oil in the oil chamber B is transferred to the boat 8A.
Then, the boat 8B becomes in communication and flows into the oil chamber A.

On the other hand, during the extension-side operation in which the tip of the upper arm 22 rotates downward, the oil chamber A contracts and the oil chamber B expands.

As a result, the hydraulic oil in the oil chamber A is removed from the above gap a.

It flows into the oil chamber B from b, c, and d while generating a rebound damping force, and when the pressure in the oil chamber A rises above a certain level, the relief valve 11 is pushed open via the boat 8A, and the pressure in the oil chamber A is increased. The hydraulic oil flows into the oil chamber B through communication between the boat 8A and the boat 8B.

The pressure receiving part 11B of the relief valve II facing the boat 8B is formed on the outside of the pressure receiving part 11A facing the boat 8A, and since the pressure receiving area is larger, the relief pressure when the relief valve 11 is opened is low, and therefore the generated attenuation is The force will be greater than the extension side or the overwhelm.

The relief pressure of the relief valve 11 can be set arbitrarily by changing the spring load of the leaf spring 13.

In this case, if the relief pressure is increased, the differential pressure between oil chambers A and B will increase, and a large load will be applied to the vane body 5 and the swing shaft l.In this rotary damper, the side plate 6A and 6B increases the rigidity of the vane main body 5, resulting in a structure that can sufficiently withstand high pressure, and it is possible to generate sufficient damping force without increasing the dimensions of the vane 4 or the swing axis l.

Next, the effects of gaps a, b, c, and d will be described.

In this case, the wall thickness of the casing 2 is formed to a thickness that can be deformed by the internal pressure of the oil chamber A or the oil chamber B.

Furthermore, in the present invention, in order to reduce the amount of change in damping force due to temperature changes, the separate blocks 7A and 7B are made of a material different from that of the rotating shaft 10 and the side plates 6^ and 6B, that is, a material with a larger thermal expansion coefficient than these. It is molded with

The damping torque is generated by the flow resistance between the outer circumferential gap a of the vane body 5 and the outer circumferential gaps of the side plates 6A and 6B.
Adjustment of the damping force characteristics is already managed in the gap.

The amount of oil leaking from the gap Q is expressed as Q=Wδ3/12ILJIXΔP ---' (1).

However, △P: Differential pressure IL (= νρ); Absolute viscosity ν; *Viscosity ρ: Density intersection; Gap length W: Gap width δ: Distance between PIRs of the vane main body 5 as shown in FIG. If it rotates clockwise from this position, the pressure in the oil chamber B will be high.

As the vane 4 rotates clockwise, the volume of the oil chamber B decreases, and at the same time, the width of the gap corresponding to the oil chamber B also decreases.

This means that in the above equation (1), the gap width W or the vane 4
This corresponds to decreasing with the rotation angle.

Therefore, if the amount of leakage is constant and the angular velocity of vane rotation is constant, W is the largest at the beginning of vane rotation, so ΔP is small, and as the vane rotates, ΔP increases,
The maximum value is reached at the end of the rotation stroke.

The same applies when rotating in the opposite direction.

Since the damping force is generated by ΔP, the damping force becomes higher as it approaches the end of the vane rotation angle, and a damping force characteristic that depends on the position of the vane can be obtained.

Therefore, when the rotary damper of the present invention is used in a vehicle suspension, the closer the suspension stroke end is, the higher the damping force is position-dependent.In other words, the smaller the suspension amplitude is, the lower the damping force is. Characteristics obtained.

In the above operation, if the wall thickness of the casing 2 corresponding to the outer periphery of the vane main body part 5 is formed with a deformable wall thickness or material, as shown in FIG. When the pressure is high, it bulges outward as shown in the exaggerated example.

At the beginning of the rotation of the vane 4, the oil chamber B is large and the range of pressure acting on the inner periphery of the casing 2 is wide, so the amount of outward deformation of the casing 2 is also large.

As the vane rotates, the applied pressure range decreases, and the amount of change in the radial direction also decreases as the rotation angle increases.

The deformation phenomenon of the casing 2 as described above has an effect on the damping torque, as it increases the gap interval δ in equation (1) above, so the damping torque is small at the initial position of the stroke, and the phenomenon occurs at the end of the stroke. The torque is increased, and the position-dependent damping force characteristics can be further improved.

As shown in equation (1), the gap interval δ affects the value of the differential pressure ΔP to the third power, so even small deformations are effective.

Further, since the differential pressure ΔP in equation (1) depends on the rotational angular velocity, when the rotational angular velocity is small, ΔP is small, and the amount of deformation of the casing 2 is small, and the damping torque is not affected by the deformation of the casing 2.

Conversely, as the rotational angular velocity increases, ΔP increases, the amount of casing deformation also increases, and the damping torque is affected by the casing deformation and becomes smaller than the value without deformation.

This relationship is shown in diagram W46, and if the casing 2 is appropriately deformed by the differential pressure ΔP, the relationship between the rotational angular velocity and the damping torque becomes an η-multiplying characteristic, and a characteristic equal to or better than that of a cylindrical damper can be obtained.

Next, the effects of gaps c and d will be described.

The above equation (1) also holds true for the gaps c and d, and when the kinematic viscosity ν changes, the distance δ between the gaps c and d changes.

For example, when one type of silicone oil is used as a hydraulic fluid, ν is 300% at a temperature of -30°C, and 30% at a temperature of 100°C.
It changes by about %.

At this time, if δ is constant, the generated damping torque will change by about 10 times.

Therefore, in the present invention, separate blocks 7A and 7R
expands or contracts depending on the temperature, and when the temperature rises, gaps c and d
The interval δ becomes smaller and becomes larger as the temperature becomes lower.

For this reason, temperature compensation is added to the gap flow in gaps c and d,
The flow rate change due to the gaps c and d is almost constant regardless of temperature change, and the change in the generated damping torque is also reduced.

The vane 4 and side plates 6A and 6B are made of #-based material (
Thermal expansion coefficient 11.7x 10-'), separate blocks 7A and 7B are made of aluminum material (thermal expansion coefficient 23Jx
10-'), if the gaps c and d are set to several gm, the variation in the damping torque generated can be reduced to about 50% or less compared to the case without temperature compensation.

(Effect of the invention) According to the present invention, there are the following effects.

(2) According to the invention of claim (1), since an arbitrary gap is formed between the inner periphery of the casing and the outer periphery of the side plate, damping force characteristics depending on the position of the vane can be obtained.

Moreover, since the casing is molded with a wall thickness or material that can expand outward under internal pressure, a damping torque that depends on the position of the vane corresponding to the wall thickness or material can be obtained, resulting in damping equal to or greater than that of a cylindrical damper. Torque characteristics can be obtained.

■ According to the invention of claim (2), the position-dependent damping torque characteristic described above can be obtained, and the size of the gap is changed by expanding or contracting the separate block in accordance with temperature changes, so that oil leakage due to temperature can be prevented. It is possible to reduce the amount of change in damping torque almost regardless of viscosity changes.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of a rotary damper according to an embodiment of the present invention, FIG. 2 is a cross-sectional side view of FIG. 1, FIG. 3 is a schematic perspective view of a vane, and FIG. 4 is a rotary damper of FIG. Hydraulic circuit diagram of the damper, Figure 5 is a schematic cross-sectional side view showing the deformed state of the casing during operation, Figure 6 is a graph of damping torque, and Figure 7 is a schematic side view showing the state of the rotary damper installed on the vehicle. It is a diagram. (Explanation of symbols) l... Swing shaft 2... Casing 4...
・Vane 5... Vane body part 6^, 6
B-・Sight brake) 11... Relief valve A, B-・
・Oil chamber v-...Valves a, b, c, d...
Gap agent Patent attorney Izumi Amano Figure 2 Figure 4 Figure 5 Rotational angular velocity

Claims (2)

[Claims] (1) A casing, a pair of separate blocks provided on the inner periphery of the casing, a swing shaft having a vane rotatably inserted into the casing, a side plate provided at the end of the vane, and a separate block. and a plurality of oil chambers defined in the casing by the vane, between the inner periphery of the casing and the outer periphery of the vane, between the inner periphery of the casing and the outer periphery of the side plate, and between the side surface of the side plate and the side surface of the separate block. , a damping force generation gap provided between the swing shaft and the separate block to communicate the oil chambers with each other, and a relief valve provided in a passage communicating the oil chambers, and a casing. A rotary damper characterized in that the casing is molded with a deformable wall thickness or material, and the casing is expanded outwardly by internal pressure to vary the gap between the casing and the side plate according to the internal pressure. (2) A casing, a pair of separate blocks provided on the inner periphery of the casing, a swing shaft having a vane rotatably inserted into the casing, a side plate provided at the end of the vane, and a separate block. and a plurality of oil chambers defined in the casing by the vane, between the inner periphery of the casing and the outer periphery of the vane, between the inner periphery of the casing and the outer periphery of the side plate, and between the side surface of the side plate and the side surface of the separate block. , a separate block comprising a damping force generation gap provided between the swing shaft and the separate block and communicating the respective oil chambers with each other, and a relief valve provided in a passage communicating the oil chambers. is made of a material with a larger coefficient of thermal expansion than the swing shaft and the side plate, and the gap between the swing shaft and the separate block and the gap between the side plate and the separate block can be made variable depending on temperature changes. A rotary damper characterized by