JP2001010320A - Hydraulic buffer for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic buffer for a vehicle to simplify structure and form the buffer in a compact manner and firmly couple a subtank to a cylinder body. SOLUTION: In a hydraulic buffer 1 for a vehicle provided with a subtank 3 positioned separably from a cylinder body 2, a rod member 18 is situated at a cylinder body 2. One end of a fit-in member 22 extending in a direction in which it crosses the axis of the rod member 18 is rotatably held in a fitted-in state and the subtank 3 is mounted on the other end part of the fit-in member 22. An oil chamber S1 in the cylinder body 2 and an oil chamber S3 in the subtank 3 are brought into intercommunication through oil passages 18a and 22a formed in the rod member 18 and the fit-in member 22. This constitution, since the oil passages 18a and 22a to effect intercommunication between the oil chambers S1 and S3 of the cylinder body 2 and the subtank 3 are formed in the rod member 18 and the fit-in member 22, functions the fit-in member 22 as both a rotation detent member and a communication member, reduces the number of parts by eliminating need for a hose and forms the buffer in a compact manner as a result of the structure of the hydraulic buffer 1 being simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle hydraulic shock absorber having a sub-tank separate from a cylinder body.

[0002]

2. Description of the Related Art A hydraulic shock absorber used as a suspension system for a vehicle such as an automobile generates a required damping force due to a flow loss (energy loss) of hydraulic oil filled in a cylinder. Absorbs and reduces the impact received from the road surface via the wheels.

[0003] In such a hydraulic shock absorber,
Since the volume occupied by the hydraulic oil in the cylinder is increased or decreased by the stroke volume of the piston rod protruding and retracting from the cylinder, it is necessary to absorb this increase or decrease in volume by compressing and expanding the gas.

Therefore, a hydraulic shock absorber in which a sub-tank having a gas chamber is formed separately from the cylinder main body and this sub-tank is attached to the cylinder main body has been proposed and has already been put to practical use.

[0005]

By the way, in a vehicle hydraulic shock absorber having a separate sub-tank, a fitting member is fitted and held on a rod member, and the sub-tank is attached to the fitting member and a cylinder is provided. A configuration was adopted in which a flexible hose was connected to the fitting member to allow the oil chambers of the main tank and sub tank to communicate with each other. This increased the number of parts and required a hose connection structure, complicating the structure. There was a problem of doing.

[0006] In addition, a configuration in which the sub-tank is directly connected to the cylinder body by screw connection has been adopted. However, in this configuration, since the screw fixing portion needs to be thick, the hydraulic shock absorber becomes larger and heavier. There was a problem.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a hydraulic shock absorber for a vehicle which has a simple and compact structure and can firmly connect a sub-tank to a cylinder body.

In a conventional vehicle hydraulic shock absorber adopting a structure in which a sub-tank is attached to a fitting member fitted to a rod member, the sub-tank is fixed to the vehicle body, and the sub-tank and the cylinder body are flexible. Since there is no means for restricting the rotation of the cylinder body, the rotation of the cylinder body is restricted by the pulling force of the hose, which reduces the durability of the hose. Was causing it.

Accordingly, an object of the present invention is to provide a hydraulic shock absorber for a vehicle which can reliably restrict the rotation of the sub-tank without depending on the pulling force of other parts and can prevent interference with other parts. To provide equipment.

[0010]

According to a first aspect of the present invention, there is provided a vehicle hydraulic shock absorber having a sub-tank separate from a cylinder body, wherein a rod member is provided above the cylinder body. The rod member is rotatably fitted at one end of a fitting member extending in a direction intersecting the axis of the rod member, and the sub-tank is attached to the other end of the fitting member. And an oil chamber in the cylinder main body and an oil chamber in the sub-tank communicate with each other through oil passages formed in the fitting member.

According to a second aspect of the present invention, in the first aspect, a regulating member fixed to the vehicle body is brought into contact with the fitting member to regulate the rotation of the fitting member and the sub tank. It is characterized by doing so.

According to a third aspect of the present invention, in the first or second aspect of the present invention, a throttle member having an opening area adjustable from outside the axial direction of the rod member is provided in the oil passage formed in the rod member. It is characterized by having.

According to a fourth aspect of the present invention, in the first, second or third aspect of the present invention, the main body of the sub-tank and the fitting member are formed separately, and both are connected.

Therefore, according to the first aspect of the present invention, since the oil passage for connecting the cylinder body and the respective oil chambers of the sub-tank is formed in the rod member and the fitting member, the fitting member also serves as the communication member. This eliminates the need for a conventional hose or the like, reduces the number of parts, and simplifies the structure of the hydraulic shock absorber. Further, since the sub-tank is fixed to the cylinder body via a rod member and a fitting member instead of the conventional screw fixing, the fixing portion can be made thinner to make the hydraulic shock absorber compact, and the sub-tank can be formed. It can be firmly connected to the cylinder body via the rod member and the fitting member.

According to the second aspect of the invention, the regulating member fixed to the vehicle body is brought into contact with the fitting member to regulate the rotation of the fitting member and the sub tank attached thereto. In addition, the rotation of the sub-tank is reliably controlled without depending on the pulling force of other parts, and interference with other parts is prevented. If the restricting member fixed to the vehicle body is brought into contact with the distal end of the fitting member, the torque for restricting the rotation of the sub tank can be reduced.

According to the third aspect of the present invention, since the regulating member fixed to the vehicle body is provided at a position separated from the rod member, the opening area of the throttle member is changed from outside the rod member in the axial direction. The damping force can be adjusted with good workability.

According to the fourth aspect of the present invention, since the main body of the sub-tank and the fitting member are formed separately and connected to each other, the main body of the sub-tank is changed by changing the length of the fitting member for each model. Can be shared with other models.

[0018]

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

FIG. 1 is a longitudinal sectional view of a hydraulic shock absorber for a vehicle according to the present invention, FIG. 2 is an enlarged sectional view of the upper part of the hydraulic shock absorber, FIG. 3 is a sectional view taken along line AA of FIG. 2, and FIG. FIG. 3 is a sectional view taken along line BB of FIG.

A vehicle hydraulic shock absorber 1 according to the present embodiment is used for a strut type suspension system of a four-wheeled vehicle, and is separately provided on an upper side of a cylinder body 2 as shown in FIG. The body sub-tank 3 is attached.

In the cylinder body 2, an outer cylinder 5 is slidably fitted on the outer periphery of the cylinder 4 from below, and a hollow piston rod 6 is provided inside the outer cylinder 5 along its axis. The lower part is fixed by the plate 7 and stored. The piston rod 6 is inserted into the cylinder 4 from below, and a piston 8 that fits on the inner periphery of the cylinder 4 so as to be slidable up and down is connected to the upper end thereof by a nut 9. Incidentally, caps 10 and 11 are fitted on the inner periphery of the lower end of the cylinder 4, respectively.
The piston rod 6 is inserted into the cylinder 4 through the center of these caps 10 and 11.

In the cylinder 4, upper and lower oil chambers S1 and S2 are defined by the piston 8, and each of the oil chambers S1 and S2 is filled with hydraulic oil.

The piston 8 is provided with a plurality of oil holes 8a and 8b, and a plate-like valve 1 for opening and closing the oil holes 8a and 8b respectively on upper and lower surfaces thereof.
2 and 13 are respectively attached.

An orifice 14 is provided above the inside of the piston rod 6, and the opening area of the orifice 14 is adjusted by an adjusting rod 15 inserted into the piston rod 6 from below. That is, the adjustment rod 15
Is screwed to the inner circumference of the upper end of the piston rod 6, and when the adjustment rod 15 is rotated by the adjustment dial 16 attached to the lower end, the adjustment rod 1
5 moves up and down in the piston rod 6, and its sharply tapered upper end protrudes and retracts with respect to the orifice 14, whereby the opening area of the orifice 14 is adjusted as described above. A plurality of oil holes 6a are formed below the position where the orifice 14 of the piston rod 6 is provided.

On the other hand, a cylindrical boss member 17 is attached to the inner periphery of the upper end of the cylinder 4.
The outer periphery of the lower end of the rod member 18 is screwed onto the inner periphery of the rod member 18. Incidentally, as shown in FIG.
Reference numeral 8 denotes a rotation stopper screw 44 screwed to both sides from the lateral direction, and the rotation stopper screw 44 is prevented from coming off by a spring receiver 19 fitted on the outer periphery of the boss member 17. A cushion spring 21 is stretched between the spring receiver 19 fitted on the outer circumference of the boss member 17 and a spring receiver 20 screwed on the outer circumference of the outer cylinder 5 so as to be vertically adjustable. .

By the way, as shown in detail in FIG. 2, the base end of the fitting member 22 is provided on the outer periphery of the rod member 18 through the upper and lower O-rings 46 around the axis of the rod member 18 (horizontally). The fitting member 22 is rotatably fitted and held.
The upper part of the sub tank 3 is located at the tip (free end) of FIG.
4 and two bolts 23 as shown in FIG. The rod member 18 is formed with a plurality of (four in the present embodiment) engagement holes 18d for inserting a tool for screwing the rod member 18 into the boss member 17. The hole 18d is covered by the fitting member 22.

Here, as shown in FIG.
Is formed by attaching a cap 25 to the upper end of a cylinder 24, and a free piston 26 is fitted inside the cylinder 24 so as to be slidable up and down. The sub tank 3 is partitioned by the free piston 26 into an upper oil chamber S3 and the lower portion of the gas chamber S _G, the oil chamber S3, hydraulic oil is filled, the gas chamber S _G nitrogen ( A stable inert gas such as N ₂ gas is sealed.

The oil chamber S1 of the cylinder body 2 and the oil chamber S3 of the sub-tank 3 are connected to an oil passage 18a formed at the center of the rod member 18 and an oil passage 22a formed at the fitting member 22. And both oil passages 18
a, 22a are a plurality of oil holes 1 formed in the rod member 18.
8b communicate with each other.

As shown in detail in FIG. 2, the oil passage 18a formed in the rod 18 is
7 is provided so as to be sandwiched between a cylindrical holder 28 and a nut member 29 at the top and bottom. An oil hole 27a is formed in the center of the throttle member 27, and a plurality of small holes 27b are formed around the oil hole 27a. Have been. A plate-shaped valve 30 for opening and closing the oil hole 27a is in contact with the upper surface of the throttle member 27 by a spring 31. One end (upper end) of the spring 31 is screwed into the holder 28 so as to be vertically movable. It is received by the adjusting rod 32. A ring-shaped valve 44 for opening and closing the small hole 27 b is urged by a spring 45 on the lower surface of the throttle member 27. Note that the upper end of the adjustment rod 32 faces a circular hole 18c formed through the center of the upper axis of the rod member 18.

Here, the throttle member 27 is provided below the rod member 18 and a small-diameter circular hole 18c for inserting a tool for operating the adjustment rod 32 from outside is formed in the upper half of the rod member 18. By reducing the diameter of the upper half of the rod member 18, the upper mounting portion of the hydraulic shock absorber 1 can be made compact.

The throttle member 27 and the valve 3
0, 44, springs 31, 45, adjustment rod 32, etc., constitute a damping force adjustment mechanism.

The hydraulic shock absorber 1 for a vehicle shown in FIG. 1 configured as described above is fixed to the vehicle body 34 by attaching the rod member 18 to the vehicle body 34 via a spherical bearing 33 as a pin joint member. The lower portion is connected to wheels (not shown) via brackets 35 and 36 connected to the outer periphery of the outer cylinder 5. In FIG. 1,
37 is a bump stopper and 38 is a lock nut.

A plate 39 is attached to the vehicle body 34 by a plurality (three in the illustrated example) of bolts 40 and nuts 41. The rod member 18 of the hydraulic shock absorber 1 is mounted on the plate 39 by a spherical bearing 33. A plurality of bolts 42 are attached to the vehicle body 34, and a regulating member 43 is attached to the vehicle body 34 together with the plate 39 by bolts 40 and nuts 41, and at a predetermined angular position of the regulating member 43 as shown in FIG. Is two contact parts 4
3a is integrally provided vertically downward. The two contact portions 43a of the regulating member 43 come into contact with the side portions of the arm member 22 as shown by a chain line in FIG.
2 and rod member 1 of sub tank 3 attached to it
The rotation around the center 8 is restricted to the angle range α shown in FIG.

Next, the operation of the hydraulic shock absorber 1 will be described.

When the piston rod 6, the piston 8 and the outer cylinder 5 of the cylinder body 2 move upward with respect to the cylinder 4 integrally from the expansion state shown in FIG. The hydraulic oil in the chamber S1 passes through the oil hole 8a of the piston 8, pushes and opens the valve 13 with its pressure, flows into the lower oil chamber S2, and forms in the orifice 14 and the piston rod 6 provided in the piston rod 6. The oil flows into the lower oil chamber S2 through the plurality of oil holes 6a. Further, an amount of hydraulic oil corresponding to the stroke volume of the piston rod 6 entering the cylinder 4 flows from the oil chamber S1 through the oil passage into the oil chamber S3 in the sub-tank 3, and corresponds to the inflow amount of the hydraulic oil. free piston 26 by a stroke that moves downward in the sub-tank 3 is to compress the gas in the gas chamber S _G, the hydraulic oil in the oil chamber S1 is the process through a circular hole formed in the center of the valve 44 to The valve 30 is pushed open from the oil hole 27a of the throttle member 27 to flow into the oil chamber S3.

Thus, a predetermined damping force is generated in the hydraulic shock absorber 1 by the flow loss (energy loss) in each part due to the flow of the hydraulic oil in the above-described compression stroke. Is absorbed by the road surface via the wheels and is absorbed and reduced.

As described above, the adjusting dial 16 is operated to rotate the adjusting rod 15, and the tip of the adjusting rod 15 is made to protrude and retract from the orifice 14, thereby changing the opening area of the orifice 14. As a result, the flow resistance of the hydraulic oil passing through the orifice 14 changes, and the damping force is adjusted.

Further, a tool (not shown) is inserted through a circular hole 18c opened at the upper end of the rod
When the adjusting rod 32 is turned externally, the adjusting rod 32 is
And the length of the spring 31 compressed between the valve and the valve 30 changes, and the set load of the spring 31 changes. The flow resistance changes and the damping force is adjusted.

On the other hand, in the extension stroke in which the piston rod 6, the piston 8, and the outer cylinder 5 move downward integrally with the cylinder 4, the hydraulic oil in the lower oil chamber S2 in the cylinder 4 is filled with the oil hole of the piston 8. 8b, the valve 12 is pushed open by that pressure and flows into the upper oil chamber S1 through the oil hole 6a formed in the piston rod 6 and the orifice 14, while flowing into the upper oil chamber S1. Further, an amount of hydraulic oil corresponding to the retraction stroke volume of the piston rod 6 from the cylinder 4 is transferred from the oil chamber S3 in the sub tank 3 to the oil passages 22a,
It flows into the oil chamber S1 in the cylinder 2 through 18a, although the gas by a stroke corresponding to the inflow of hydraulic oil free piston 26 moves upwards to the gas chamber S _G in the sub-tank 203 is expanded, In this process, the hydraulic oil in the oil chamber S3 in the sub tank 3 passes through the small hole 27b of the throttle member 27 and the valve 44.
To open and flow into the oil chamber S1 of the cylinder 2.

Thus, a predetermined damping force is generated in the hydraulic shock absorber 1 by the flow loss (energy loss) in each part due to the flow of the hydraulic oil in the above-described extension stroke, and the same as in the compression stroke. By this damping force, the impact that the vehicle body 34 receives from the road surface via the wheels is absorbed and mitigated.

By operating the adjustment dial 16 and turning the adjustment rod 15, the damping force during the extension stroke can be adjusted in the same manner as described above.

As described above, in this embodiment, the sub-tank 3 is attached to the other end of the fitting member 22 which is rotatably held at one end with respect to the rod member 18, and the oil in the cylinder main body 2 and the sub-tank 3 Since the oil passages 18a and 22a for communicating the chambers S1 and S3 are formed in the rod member 18 and the fitting member 22, respectively, the fitting member 22 also serves as the communication member, and a conventional hose or the like becomes unnecessary. The number of parts is reduced, and the structure of the vehicle hydraulic shock absorber 1 is simplified. Since the sub tank 3 is fixed to the cylinder main body 2 via the rod member 18 and the fitting member 22 instead of the conventional screw fixing, the fixing portion can be thinned to make the hydraulic shock absorber 1 compact. The sub tank 3 can be connected to the rod member 18 and the fitting member 2.
2 can be firmly connected to the cylinder body 2.

Further, according to the present embodiment, the regulating member 43 fixed to the vehicle body 34 is brought into contact with the fitting member 22 to rotate the fitting member 22 and the sub-tank 3 attached thereto. Since the regulation is performed, the rotation of the sub tank 3 is reliably regulated without depending on the pulling force of another component (such as a conventional hose), and interference with the other component is prevented. In the present embodiment, since the contact portion 43a of the regulating member 43 fixed to the vehicle body 34 is brought into contact with the tip end of the fitting member 22, the fitting member 22 and the sub tank 3
Torque for restricting the rotation of the motor can be reduced. Further, since one end of the fitting member 22 is rotatably fitted to and held by the rod member 18, the sub tank 3 attached to the fitting member 22 is also rotatably supported with respect to the rod member 18. After assembling the vehicle hydraulic shock absorber 1, the sub tank 3 can be rotated within a predetermined range by overcoming the friction caused by the O-ring 46, and can be arranged at an appropriate position.

Further, in the present embodiment, the vehicle body 34
Since the regulating member 43 fixed to the side is provided at a position separated from the rod member 22, the adjusting rod 32 is turned from the outside in the axial direction of the rod member 22 to move the adjusting rod 32 up and down. Since the damping force is adjusted by changing the opening area of the damper, the adjustment of the damping force can be performed with good workability while avoiding interference with the regulating member 43.

Further, in this embodiment, since the sub-tank 3 and the fitting member 22 are formed separately and are connected by bolts 23, the length of the fitting member 22 is changed for each model. Thus, the sub tank 3 can be shared by various models. In addition, sub tank 3
The cap 25 may be integrated, and the cylinder 24 of the sub tank 3 may be screwed onto the cap 25.

[0046]

As is apparent from the above description, according to the present invention, in a vehicle hydraulic shock absorber having a subtank separate from a cylinder body, a rod member is provided on an upper portion of the cylinder body. One end of a fitting member extending in a direction intersecting the axis of the member is rotatably fitted and held, and the sub-tank is attached to the other end of the fitting member. Since the oil chamber in the cylinder body and the oil chamber in the sub-tank are communicated with each other through oil passages respectively formed in the members, the structure of the vehicle hydraulic shock absorber can be simplified to reduce its size. In addition to this, there is an effect that the sub tank can be firmly connected to the cylinder body.

Further, according to the present invention, since the regulating member fixed to the vehicle body is brought into contact with the fitting member to regulate the rotation of the fitting member and the sub-tank, the tension force of the other parts is reduced. The effect is obtained that the rotation of the sub-tank can be surely regulated without depending on it and interference with other parts can be prevented.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a vehicle hydraulic shock absorber according to the present invention.

FIG. 2 is an enlarged sectional view of an upper portion of a vehicle hydraulic shock absorber according to the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is an enlarged sectional view taken along line AA of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic shock absorber for vehicles 2 Cylinder main body 3 Subtank 6 Piston rod 8 Piston 18 Rod member 18a Oil passage 22 Fitting member 22a Oil passage 27 Throttle member 34 Body 43 Restriction member S1, S2 Oil chamber in cylinder body S3 Inside sub tank Oil chamber

Claims (4)

[Claims] 1. A vehicle hydraulic shock absorber having a sub tank separate from a cylinder body, wherein a rod member is provided on an upper portion of the cylinder body, and the rod member is fitted to the rod member in a direction intersecting the axis thereof. One end of the member is rotatably fitted and held, the sub-tank is attached to the other end of the fitting member, and the inside of the cylinder body is connected via oil passages formed in the rod member and the fitting member, respectively. A hydraulic shock absorber for a vehicle, characterized in that the oil chamber of (1) communicates with the oil chamber in the sub tank. 2. The vehicle according to claim 1, wherein a regulating member fixed to the vehicle body is brought into contact with said fitting member to regulate rotation of said fitting member and said sub-tank. For hydraulic shock absorber. 3. The hydraulic pressure for a vehicle according to claim 1, wherein a throttle member whose opening area is adjustable from outside the axial direction of the rod member is provided in the oil passage formed in the rod member. Shock absorber. 4. The hydraulic shock absorber for a vehicle according to claim 1, wherein the main body of the sub-tank and the fitting member are formed separately and connected to each other.