JP4630638B2 - Hydraulic shock absorber - Google Patents

Description

The present invention relates to a double-cylinder strut type hydraulic shock absorber used as a vehicle suspension device provided with a function as a steering damper in a cylinder .

  Conventionally, in a vehicle such as an automobile, the force that turns the steered wheel from the steered wheel side is input as a so-called kickback due to road surface irregularities and obstacles during traveling, so that the impact is mitigated. A steering damper is provided for this purpose.

As this steering damper, what is provided in the steering shaft part which connects the steering wheel and the gear box shown in Patent Document 1, and what is provided between the power cylinder shown in Patent Document 2 and a switching valve for switching the power cylinder Etc. can be illustrated.
Japanese Patent Laid-Open No. 7-40840 (FIG. 1) Japanese Patent Laid-Open No. 2001-301632 (FIG. 1)

  The steering damper configured as described above is not particularly problematic, but when it is provided between the steering shaft portion or between the power cylinder and the switching valve, an extra component that appears on the appearance. Therefore, the space efficiency is poor and the mountability to the vehicle is reduced accordingly.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a double-cylinder strut type hydraulic shock absorber that is used as a suspension device having a steering damper function that can be easily mounted on a vehicle body by reducing extra components that appear on the exterior. It is to be.

In order to achieve the above object, the means of the present invention includes a cylinder, a piston rod which is inserted and retracted through the piston into the cylinder and connected to the vehicle body, and is separated from the cylinder through the piston. The rod side chamber and the anti-rod side chamber, the extension side port and the pressure side port formed in the piston and communicating with the rod side chamber and the anti rod side chamber, and the outlet end of the extension side port and the pressure side port are provided to be openable and closable. In the double-cylinder strut type hydraulic shock absorber provided with an expansion side valve and a pressure side valve, the cylinder and the piston rod rotate relatively when the steering wheel is steered from the steering wheel side. A damping force generating member that generates a damping force in conjunction with the cylinder when rotating is provided in the rod side chamber or the anti-rod side chamber.
In this case, the damping force generating portion includes a plurality of semi-cylindrical body portions that rotatably contact the outer periphery of the piston rod, and a plurality of fins that extend from each body portion in the diameter direction and are fixed to the inner peripheral surface of the cylinder. It is preferable that it is comprised by the part and the orifice drilled in each fin part.
Similarly, the damping force generating member may be composed of a plurality of fin portions projecting inward from the inner peripheral surface of the cylinder and an orifice drilled in the central portion of the fin portion.
The fin member is preferably made of a shape memory alloy, and its shape is preferably deformed according to the oil temperature in the cylinder.

According to the present invention, when a force for turning the steered wheel from the steered wheel side is input as a so-called kickback due to road surface irregularities or obstacles during traveling, the fixed piston rod is used as the center of rotation. The cylinder rotates.
At this time, since the damping force generation member of the present invention is provided in the rod side chamber or the anti-rod side chamber in the cylinder, the damping force generation member generates a damping force in conjunction with the cylinder by the rotation of the cylinder, Mitigates the above kickback.

  Therefore, according to this hydraulic shock absorber, the steering damper function can be provided without having extra components that appear on the exterior as in the prior art, so that the mountability to the vehicle body can be improved.

Hereinafter, an embodiment in which the present invention is embodied in a strut-type hydraulic shock absorber used in a suspension device on the steering wheel side of an automobile will be described with reference to the drawings.
As shown in FIG. 1, the basic structure of the hydraulic shock absorber according to the present invention includes an inner cylinder 3 as a cylinder, and a piston rod 4 that is inserted into the inner cylinder 3 via a piston 5 so as to be retractable and connected to a vehicle body. The rod side chamber R and the anti-rod side chamber P separated from each other through the piston 4 in the inner cylinder 3 and the expansion side port and the pressure side formed in the piston 5 and communicating the rod side chamber R and the anti-rod side chamber P. A port 18 and an extension side valve 21 and a pressure side valve 20 provided at the outlet ends of the extension side port and the pressure side port 18 so as to be openable and closable, respectively, and when the steering wheel is steered from the steering wheel side , This is a double-cylinder strut type hydraulic shock absorber in which the cylinder 3 and the piston rod 4 rotate relatively.
The present invention is characterized in that a damping force generating member that generates a damping force in conjunction with the inner cylinder 3 when the inner cylinder 3 is rotated is provided in the rod side chamber R or the anti-rod side chamber P. is there.
This will be described in detail below.

  As shown in FIG. 1, the hydraulic shock absorber 1 includes an outer cylinder 2 provided with a knuckle bracket (not shown) at the lower end, an inner cylinder 3 as a cylinder inserted into the outer cylinder 2, and the inner cylinder 3. A piston rod 4 protruding and retracting from the inside, a piston 5 connected to the base end of the piston rod 4 (referring to the lower side in FIG. 1) and separating the inner cylinder 3 into a rod side R chamber and an anti-rod side P chamber, A rod guide 9 arranged at the opening end of the cylinder 3 to guide the piston rod 4, a fin member 8 as a damping force generating member of the present invention provided on the lower surface of the rod guide 9, A stopper member 6 provided on the base end side and a cylindrical rebound cushion 7 placed on the upper surface of the stopper member 6 are provided, and the piston rod 4 is fixed to the vehicle body in a non-rotatable manner. In the above-mentioned outer cylinder And the inner cylinder 3 in accordance with the steering by the rotation mechanism (not shown) rotatably attached to the rotation about said piston rod 4.

  Hereinafter, in detail, the outer cylinder 2 and the inner cylinder 3 are arranged concentrically, and the rod guide 9 is fitted over the inner periphery of the end of the outer cylinder 2 and the end of the inner cylinder 3. .

  As shown in FIG. 2, the fin member 8 includes a main body portion 12 having a semi-cylindrical shape in which a metal plate is curved and formed in substantially the same shape as the outer peripheral surface of the piston rod 4, and two fin members 8 extending in the diameter direction from the main body portion 12. The fin member constituting body 14 composed of two fin portions 13 is combined, and the fin member constituting body 14 composed of the two members is integrated by joining the opposing fin portions 13 together by welding or the like. It has become.

  Then, the outer peripheral end of the fin portion 13 is fixed to the inner peripheral surface of the inner cylinder into which the piston 5 and the piston rod 4 are inserted in advance by press fitting, welding, or caulking, etc. The fin member 8 is fixed to the lower surface of 9, and the piston rod 4 slides inside the main body 12 of the fin member 8.

  As shown in FIG. 1, the fin portion 13 is formed in a front rectangular shape, and an orifice 15 is formed in the approximate center thereof. The inner cylinder 3 and the outer cylinder 2 are formed around the piston rod 4 as a rotation center. The hydraulic oil in the inner cylinder 3 passes through the orifice 15 when it rotates, so that a damping force is generated.

The stopper member 6 is formed in a cylindrical shape having a flange portion 11 at the upper portion thereof, and is inserted into the piston rod 4 and fixed to the upper portion of the piston 5 serving as the base end side of the piston rod 5 by welding or the like.

  The rebound cushion 7 is formed in a cylindrical shape from natural rubber, synthetic rubber or synthetic resin, and is movably mounted on the flange portion 11.

  The piston 5 is inserted into the base end side mounting portion of the piston rod 4, and the piston 5 is fixed to the piston rod 4 by screwing a nut 17.

  The piston 5 is provided with a pressure side port 18 on the outer peripheral side and an expansion side port (not shown) on the inner peripheral side, and the pressure side port 18 is closed on the rod side chamber R surface of the piston 5 so as to be openable and closable. A pressure side valve 20 is provided, and an extension side valve 21 that closes the extension side port in an openable and closable manner is provided on the surface of the piston 5 opposite to the rod side chamber P.

  In the hydraulic shock absorber 1 configured as described above, when a force for turning the steered wheel from the steered wheel side is input as a so-called kickback due to road surface irregularities or obstacles during traveling, the fixed state The outer cylinder 2 and the inner cylinder 3 rotate and rotate relative to each other with the piston rod 4 as a rotation center.

  At this time, since the fin member 8 as the damping force generating member of the present invention is provided on the lower surface of the rod guide 9, the hydraulic oil in the inner cylinder 3 is rotated with the rotation of the outer cylinder 2 and the inner cylinder 3. Passes through the orifice 15 provided in the fin member 8, a damping force is generated, and the kickback is eased.

  Therefore, according to this hydraulic shock absorber 1, since it is possible to have a steering damper function without having extra components that appear on the exterior as in the prior art, it is possible to improve mountability to the vehicle body.

  Further, since the fin portion 13 has a flat plate shape, a large resistance is generated when the outer cylinder 2 and the inner cylinder 3 are rotated, and a damping force is likely to be generated. Since it does not become resistance, it can prevent reliably affecting the damping force requested | required as the hydraulic shock absorber 1. FIG.

  In addition, this invention is not limited to said embodiment, For example, it can also be changed and actualized as follows.

  1) In the present embodiment, the damping force generating member is provided on the lower surface of the rod guide 9. However, the present invention is not limited to this and may be provided in the anti-rod side chamber P.

  2) In the present embodiment, the number of the fins 13 of the damping force generation unit is two. However, the present invention is not limited to this, and may be four, one, three or more as shown in FIG.

  3) In the present embodiment, the fin portion 13 is rectangular with a metal plate material, but is not limited to this shape or material. For example, the fin portion 22 is formed of a shape memory alloy and the hydraulic oil temperature is When the temperature is low, the cross-section arc shape shown in FIG. 5 may be used to reduce the resistance, and when the hydraulic oil temperature is high, the cross-section straight line shown in FIG. 4 may be used to increase the resistance.

  In this way, the resistance during steering can be reduced when the hydraulic oil temperature is low, and the steering holding force can be improved when the hydraulic oil temperature is high.

  At this time, if the second fin portion 23 is provided on the piston rod 4 side as shown in FIG. 6, a larger damping force can be generated when the hydraulic oil temperature is high as shown in FIG.

  4) In the present embodiment, the double cylinder type strut type hydraulic shock absorber 1 is embodied. However, a single cylinder type strut type hydraulic shock absorber may be embodied.

  5) In the present embodiment, the present invention is embodied in the hydraulic shock absorber 1 for an automobile, but may be embodied in other vehicle hydraulic shock absorbers.

It is principal part sectional drawing of the hydraulic shock absorber which shows one embodiment of this invention. It is a top view which shows the fin member of FIG. It is a top view of the fin part which shows another example of the present invention. It is a top view of the fin part which similarly shows another example of the present invention. It is a top view of the fin part which shows another example of this invention and shows the deformation | transformation state of FIG. It is a top view of the fin part which similarly shows another example of the present invention. It is a top view of the fin part which shows another example of this invention and shows the deformation | transformation state of FIG.

Explanation of symbols

1 Hydraulic shock absorber 3 Inner cylinder (cylinder)
4 Piston rod 5 Piston 8 Fin member (Damping force generating member)
9 Rod guide 12 Body portion 13 Fin portion 14 Fin member structure 15 Orifice 22 Fin portion P Non-rod side chamber R Rod side chamber

Claims (4)

A cylinder, a piston rod that is inserted into and retracted through the piston through the piston and connected to the vehicle body, a rod side chamber and an anti-rod side chamber separated through the piston in the cylinder, and the piston are formed. provided and the extension side port and the compression side port that communicates the said rod-side chamber and the anti-rod side chamber, and the extension side valve and the compression side valve respectively openably provided at the outlet end of the expansion side port and the compression side port, from the steering wheel side In the double-cylinder strut type hydraulic shock absorber in which the cylinder and the piston rod rotate relatively when the steering wheel is steered, a damping force is generated in conjunction with the cylinder when the cylinder is rotated. A double-cylinder strut type hydraulic shock absorber in which a damping force generating member is provided in a rod side chamber or an anti-rod side chamber. The damping force generating portion includes a plurality of semi-cylindrical body portions that rotatably contact the outer periphery of the piston rod, a plurality of fin portions that extend in a diametrical direction from each body portion and are fixed to the inner peripheral surface of the cylinder, 2. The double-cylinder strut type hydraulic shock absorber according to claim 1, wherein the double cylinder type strut type hydraulic shock absorber is constituted by an orifice formed in each fin portion. 2. The multi-cylinder type according to claim 1, wherein the damping force generating member is composed of a plurality of fin portions projecting inward from the inner peripheral surface of the cylinder and an orifice drilled in a central portion of the fin portion. strut-type hydraulic shock absorber. The multi-cylinder strut type hydraulic shock absorber according to claim 2 or 3, wherein the fin member is formed of a shape memory alloy, and the shape of the fin member is deformed according to the oil temperature in the cylinder.

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