JPH0451229Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a damping force adjustment device for a hydraulic shock absorber that is interposed between the body and axle of a vehicle such as an automobile or a motorcycle and damps vibrations from the road surface. .

[Prior Art] In this type of conventional hydraulic shock absorber, a piston rod is movably inserted into a cylinder via a piston, and the piston divides the cylinder into two upper and lower oil chambers, and the two oil chambers are connected to the piston. They communicate through a passage provided in the piston rod, and a leaf valve is provided at the passage opening end of the piston so as to be openable and closable, and a valve is provided in the middle of the passage of the piston rod.

When adjusting the damping force using a valve installed in the middle of the piston rod passage, the adjustment device is
For example, a technique disclosed in Japanese Utility Model Application Publication No. 59-146636 is known.

The above conventional technology uses a needle valve as a valve seat, and this needle valve is fitted into a thin hollow portion at the lower end of a push rod which is inserted into the center hole of the piston rod so as to be able to move up and down, and the outer end of the push rod is connected to the outer end bracket of the piston rod. It engages an adjustment nut screwed nearby, and also seals a temperature compensation liquid inside the connection between the push rod and the needle valve, and this liquid is introduced through a hole in the side of the push rod and then through this hole. It is sealed by fitting a plug or a steel ball from the side, and the vertical position of the push rod and needle valve is regulated by the position of the adjustment nut, thereby setting the opening area of the passage by the needle valve.
Furthermore, when the oil temperature in the cylinder rises, the temperature compensating fluid also expands, causing the needle valve to descend and narrow the opening area of the passage.

[Problems to be solved by the invention] However, in the above technology, when filling the liquid for temperature compensation, a rope ball or the like is press-fitted into a hole provided on the outer surface of the cylindrical push rod, so the rope ball may slip. Press-fitting is extremely difficult.

Furthermore, even after press-fitting steel balls, etc., when inserting the push rod into the piston rod, the steel balls may interfere with the inner surface of the piston rod, causing damage or causing the push rod to buckle due to friction.

SUMMARY OF THE INVENTION An object of the present invention is to provide a damping force adjustment device for a hydraulic shock absorber that allows a plug such as a steel ball to be smoothly and quickly attached to a liquid introduction hole when a temperature compensation liquid is sealed.

[Means for solving the problem] In order to achieve the above purpose, the configuration of the present invention is as follows.
A piston rod is movably inserted into the cylinder via a piston, the piston partitions two oil chambers within the cylinder, a passage is provided in the piston rod to communicate the two oil chambers, and a needle valve is installed in the middle of the passage. In a hydraulic shock absorber, the needle valve is vertically movable and the needle valve is driven vertically from the outside via a control rod to adjust the opening area of the passage.The control rod is rotatably inserted into the piston rod. It consists of a rotary rod and a hollow adjusting screw that fits into the rotary rod in an odd shape and is screwed into the piston rod so that it can move vertically and in the rotational direction, and is connected to the adjusting screw through a small hole. Two upper and lower holes are formed in series, a needle valve is inserted into the lower hole so as to be movable up and down, and a liquid for temperature compensation is filled, and a plug member is introduced into the small hole through the upper hole. is press-fitted, and a rotary rod is further fitted into the upper hole.

[Function] When a steel ball or the like is pushed through the axial hole in the adjuster screw, the steel ball or the like does not slip and is smoothly and quickly press-fitted into the small hole while being centered.

[Example] An example of implementing the present invention will be described below with reference to the drawings.

A piston rod 3 is movably inserted into the cylinder 1 via a piston 2, and the piston 2 defines two upper and lower oil chambers 4 and 5 within the cylinder 1.

The piston rod 3 is connected to the vehicle body through a bracket 6 at the outer end, and the lower part of the cylinder 1 is connected to the axle side through the bracket.

The piston 2 is formed with an expansion port 7 and a pressure port 8, which are passages that communicate the two oil chambers 4 and 5, and an expansion side valve 9 is provided on the lower mouth end seat of the expansion port 7 so as to be openable and closable. A compression side valve 10 is provided on the upper mouth end seat of 8 so as to be openable and closable, and when the oil is extended, the oil in the upper oil chamber 4 bends the expansion side valve 9 through the expansion port 7, flows out into the lower oil chamber 5, and Rebound damping force is generated by the valve 9, and the lower oil chamber 5 is activated during compression.
The oil flows from the pressure port 8 into the upper oil chamber 4 by deflecting the pressure side valve 10, and the pressure side valve 10 generates a compression side damping force.

The piston rod 3 may be formed of a single hollow cylindrical body, but in this embodiment, the piston rod 3 is formed of a hollow cylindrical body 3a.
and a center rod 3b screwed into the lower part of the main body 3a.

The center rod 3b has two oil chambers 4 and 5, upper and lower.
A large hole 12 and a small hole 13 in the axial direction and a horizontal hole 14 in the radial direction are formed to communicate with each other.
6 is disposed in the seat at the mouth end of the small hole 13 so as to be openable and closable, and by adjusting the needle valve 15 up and down, the opening area of the small hole 13 is adjusted, and by squeezing the oil flowing through the small hole 13, it is possible to adjust the opening area according to the orifice characteristics. A damping force is generated.

Center rod 3b has stopper 17 and spacer 1.
8, compression side valve 10, piston 2, and expansion side valve 9
A spacer 19, a stopper 20, and a nut 21 are inserted in series, and these members are caulked with a caulking portion 22.

A cap 23 is press-fitted into the upper part of the cylinder 1 via a stop ring 24 and a seal 25.
The piston rod 3 slides on a bearing 31 provided on the inner periphery of the cap 23.

A main seal 28, a stopper 29, and a cushion rubber 30 are held at the lower part of the cap 23, and a dust seal 27 is attached to the upper part of the cap 23 via a support member 26, and the dust seal 27 is in sliding contact with the outer periphery of the piston rod 3.

A bump stopper 32 having a through hole 33 provided in the cylinder 1 is attached above the cap 23.

A bracket 6 including an eye 6a is screwed onto the upper end of the piston rod 3, and a bump rubber 35 is attached to the lower part of the bracket 6 via a nut 34.

A small hole 36 and a screw hole 37 are formed in series in the main body 3a of the piston rod 3 along the axial direction. The adjusting screw 39 is screwed together so as to be movable in the rotational and axial directions, and the adjusting screw 39 can move up and down within the range between the end surface 40 of the screw hole 37 and the upper end of the center rod 3b.

A small diameter hole 41 is provided in the adjustment screw 39.
Two holes 43 and 44 are formed which communicate in series through the holes. Inside the upper oil escape hole 44,
The tip fitting portion 45 of the rotary rod 38 is connected to the hole 44.
The rotary rod 38 and adjusting screw 39 form a control rod 60. The cross sections of the hole 44 and the fitting part 45 are formed in a rectangular, elliptical, or star shape, and when the rotary rod 38 is rotated, the rotational force is directly transmitted to the adjusting screw 39. The screws can also rotate in the same direction and can also move in the axial direction along the fitting portion 45.

The upper part of the rotary rod 38 is rotatably supported via a bush 46 and an O-ring 47, and is fitted into the center of a disc-shaped adjuster 49 in an odd shape.

The adjuster 49 is rotatably inserted into a hole 51 formed in the bracket 6 in a radially tapered shape, and the upper surface of the adjuster 49 is rotatably inserted into a stopper 48 formed of resin or the like provided above the hole 51. held in contact.

A groove 52 may be provided on the lower surface of the adjuster 49, and a positioning mechanism may be configured in combination with a locking ball (not shown) or the like.

Since the adjuster 49 is constructed from a thin disc, the axial diameter of the hole 51 into which it is inserted may be small, and the axial length of the bracket 6 can be shortened since it is not limited by space.

When the adjuster 49 is rotated from the outside, its rotational force is transmitted to the control rod 60, and the adjuster screw 39 and needle valve 15 are displaced in the axial direction.

The upper part of the needle valve 15 guided into the large hole 12 of the center rod 3b is fitted into the lower hole 43 of the adjusting screw 39 so as to be able to move up and down.
Temperature compensation liquid 5 is placed above this needle valve 15.
0. For example, grease or oil is sealed.

The needle valve 15 moves up and down in conjunction with the adjusting screw 39.

After the needle valve 15 is press-fitted into the lower part of the adjusting screw 39, the liquid 50 is introduced into the hole 43 through the upper hole 44, and then a plug member made of a steel ball 42 or the like is press-fitted through the hole 44 along the axial direction. By fitting this into the small diameter hole 41, leakage of the liquid 50 is prevented.

At this time, since a tapered surface 61 is provided at the bottom of the hole 41, when the steel ball 42 is pushed in, it moves along this tapered surface 61 and is guided to the center of the hole 41 while automatically centering. to fit.

Since the plug member such as the steel ball 42 is sealed inside the adjusting screw 39, it does not interfere with the inner periphery of the piston rod 3 when the adjusting screw 39 moves into the piston rod 3.

Next, we will discuss damping force adjustment.

For example, when the adjuster 49 is rotated clockwise, the rotary rod 38 and the adjuster screw 39 rotate in the same direction, and the adjuster screw 39 is raised via the screw, and at this time, the needle valve 15 is also raised. Therefore, the opening area of the seat portion of the small hole 13 by the valve body 16 becomes large, and a damping force corresponding to the orifice characteristic is generated.

Conversely, when the adjuster 49 is rotated counterclockwise, the needle valve 15 is lowered and the valve body 16 narrows the small hole 13.

As described above, when the oil temperature in the oil chambers 4 and 5 rises due to outside air, vibration, etc. with the opening area set, the temperature of the liquid 50 also rises, and the liquid 50 expands, causing the needle valve 15 to close. Descend, small hole 13
automatically compensates for changes in damping force due to temperature changes.

The needle valve 15 is located in the hole 12 of the center rod 3b.
Since it is guided up and down along the direction, reliable centering is possible.

[Effects of the invention] According to the invention, a liquid for temperature compensation is formed in the adjusting screw, and the plug member is press-fitted into the small hole through the axial hole for introducing this liquid to seal it. The plug member does not slip and is smoothly and quickly installed in the small hole. In particular, when a tapered surface is provided at the bottom of the hole, the plug member can be centered and guided smoothly into the small hole.

The plug member installed in the adjusting screw does not interfere with the inner periphery of the piston rod, and does not adversely affect the installation and movement of the adjusting screw.

[Brief explanation of the drawing]

The accompanying drawing is a partially cutaway longitudinal sectional front view of a hydraulic shock absorber according to an embodiment of the present invention. 1... Cylinder, 2... Piston, 3... Piston rod, 4, 5... Oil chamber, 13, 14... Passage, 15... Needle valve, 38... Rotary rod, 39... Adjustment screw , 42...
Small hole, 43, 44...hole, 50...liquid, 60...
...control rod.

Claims (1)

[Claims for Utility Model Registration] (1) A piston rod is movably inserted into the cylinder via a piston, the piston partitions two oil chambers within the cylinder, and the piston rod has a passage that communicates the two oil chambers. A hydraulic shock absorber is provided with a needle valve movable up and down in the middle of the passage, and the needle valve is driven vertically from the outside via a control rod to adjust the opening area of the passage. It consists of a rotary rod whose rod is rotatably inserted into the piston rod, and a hollow adjusting screw which is fitted in an odd shape to the rotary rod and is screwed into the piston rod so as to be movable in the vertical and rotational directions, Two holes connected by a small hole are formed in series in the adjusting screw,
A needle valve is inserted into the lower hole so as to be movable up and down, and a liquid for temperature compensation is sealed, a plug member introduced through the upper hole is press-fitted into the small hole, and a rotary valve is inserted into the upper hole. A damping force adjustment device for a hydraulic shock absorber, characterized by fitting a rod. (2) The damping force adjusting device for a hydraulic shock absorber according to claim 1, wherein a tapered surface is formed at the lower part of the upper hole. (3) The damping force adjusting device for a hydraulic shock absorber according to claim 1, wherein the liquid is grease or oil.