JPS6222016B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a damping force adjustment device for a shock absorber, and more specifically, an orifice provided in a piston rod is made variable by external operation, thereby making it possible to switch the damping force into multiple stages. This invention relates to a damping force adjustment device for a type of shock absorber that is provided with an end bolt.

The damping force adjustment method for this kind of conventional shock absorber is to make the fixed orifice in the piston variable.This means that the oil passage area of the horizontal hole in the piston rod can be made variable by the tip at the tip of the push rod. ing. To operate the push rod, the guide is rotated by an external operation, and the guide is moved by the threaded portion.At this time, the stopper that is in contact with the push rod is moved, and this stopper is in contact with the push rod, which allows the guide to rotate and move linearly. Accordingly, the push rod moves via the stopper, and as a result, the tip at the tip approaches or moves away from the opening of the through hole, thereby changing the oil passage area of the side hole.In other words, the push rod can be moved by external operation. By moving the tip of the fixed orifice, the fixed orifice is varied and the damping force is adjusted according to the opening area of this orifice. However, this conventional method requires a large number of parts and is complex.
Due to the tolerances of the piston rod, push rod, and other parts, it is necessary to correct the position of the piston rod horizontal hole and the tip, and there is also the drawback that the external guide adjustment mechanism is large and increases the basic length of the shock absorber itself. In order to solve these drawbacks, the applicant has developed a shock absorber damping force adjustment device that is compact and does not require position correction. A piston rod is slidably inserted into the cylinder via a piston, and this piston rod has a vertical hole and a horizontal hole that communicate with the liquid chamber divided by the piston, and these two holes connect the fixed orifice. The piston rod protrudes from the cylinder and is fixed to an external bracket via a support part, the rod is rotatably inserted into the piston rod via a bearing, and the cylindrical body fixed to this rod is It is rotatably arranged in the vertical hole, and the cylinder body has a plurality of orifices smaller than the horizontal hole and each having a different inner diameter bored at a position facing the horizontal hole. The orifice selectively communicates with the lateral hole, thereby making the oil passage area of the lateral hole variable and adjusting the damping force in accordance with the orifice. However, this adjustment method has a complicated structure because the operating section is built into the bracket or cover, which is the mounting eye, and is not suitable for a shock absorber equipped with an end bolt. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a damping force adjusting device which is suitable for use with a shock absorber provided with an end bolt and is simple in construction and operation.

An embodiment of the present invention will be described below with reference to the drawings.

A piston rod 3 is slidably inserted into the cylinder 1 via a piston 2, and the piston 2 partitions two upper and lower oil chambers 4 and 5 into the cylinder 1, and a free piston 6 is loosely fitted into the cylinder 1. A gas chamber 7 is defined below the free piston 6.

On the head side of the cylinder 1, there is a seal part 8 and a lid body 9.
A piston rod 3 passes through the seal portion 8 and the lid 9, and a housing 10 is fixed to the tip of the piston rod 3 by welding or the like.
The housing 10 is fixed to the inner periphery of the cover cap 11 by screws or other methods and is held by a pin 27, and the lower end of the cover cap 11 is connected to the cylinder 1.
An end bolt 13 is fixed to the upper end of a cover 12 which is disposed concentrically with the cover cap 11, and an end bolt 13 is connected to the central upper end of the cover cap 11, either integrally or by some other method. A passage 14 is bored in the piston 2 to communicate the two oil chambers 4 and 5, and a leaf valve 15 is disposed at the mouth end of the passage 14 so as to be openable and closable.

The piston rod 3 has a vertical hole 16 and a horizontal hole 17 through which the two oil chambers 4 and 5 communicate, and these two holes 16 and 17 form a fixed orifice.
Holes 18 and 19 are bored in the center of the piston rod 3, and a rod 20 is rotatably inserted into these holes 18 and 19 via bearings, and a cylindrical body 21 fixed to the rod 20 is inserted into the vertical hole. 16 so as to be rotatable. The cylindrical body 21 has a horizontal hole 1
A plurality of orifices 22a, 22 smaller than the horizontal hole 17 and each having a different inner diameter are arranged opposite to the horizontal hole 17.
b...22n are bored, and one of these orifices 22a, 22b...22n selectively communicates with the horizontal hole 17 according to the rotation of the cylinder 21, thereby making the oil passage area of the horizontal hole 17 variable. The damping force is adjusted in accordance with the orifices 22a, 22b...22n.

A groove 24 is carved in the lower end of the rod 20 to
1, and also forms a flange 25 at the upper end,
A hole or notch 26 is bored at an eccentric position of this flange 25 (FIGS. 4 and 5).

On the other hand, vertical holes 28 and 29 are provided in the center of the housing 10, cover cap 11, and end bolt 13.
The operating rod 30 is rotatably inserted into these holes 28 and 29 and the hole 19 of the piston rod 3, and the pin 31 provided at the lower end of the rod 30 is fitted into the hole 26 of the rod 20. , the two rods 20 and 30 are designed to rotate integrally.

A flange 32 provided on the operating rod 30 is rotatably inserted into a space within the housing 10, and one or more holes 33 are bored in the flange 32, and a detent ball 34 is disposed in the hole 33. ing. A spring 35 is disposed in the space inside the housing 10, and a groove 36 corresponding to the detent ball 34 is formed on the end surface of the housing 10.
4 is adapted to be selectively fitted into one of the grooves 36.

The operating rod 30 projects outward from the end bolt 13, and a knob member 38 is attached to a groove portion 37 at the tip, and when the knob member 38 is rotated, the cylinder body 21 is rotated via the rods 20, 30. There is.

In the damping force adjusting device described above, when the operating rod 30 is rotated through the knob member 38 against the spring 35 and the detent ball 34, the rod 20 connected to the pin 31 through the hole 26 rotates in the same direction. The cylindrical body 21 is thereby rotated, and one of the orifices 22a, 22b, . At this time, the detent ball 34 fits into another groove 36 to restrict the movement of the rods 20, 30 and the cylinder 21.

In the above device, by rotating the knob member 38 using, for example, a number or an arrow as a landmark, one of the desired orifices 22a, 22b...22n is made to face the horizontal hole 17, thereby controlling the oil passing area. A damping force commensurate with this orifice can be obtained, but since the orifices 22a, 22b...22n have a smaller diameter than the horizontal hole 17, the passage relationship can be secured even if the opposing positions are slightly shifted in the rotational direction or axial direction. .

According to the present invention, the number of parts is reduced compared to conventional devices. Orifices 22a, 22 of cylinder body 21
By making the diameter of b...22n smaller than that of the horizontal hole 17, the passage relationship can be ensured even if the opposing positions are slightly shifted. Therefore, if the tolerances of each part are properly taken, there is no need to correct the position between the orifices 22a, 22b, . . . 22n and the horizontal hole 17. Furthermore, since the holding portions such as the operating rod 30 are housed compactly within the housing 10, the structure is simple and the longitudinal dimension is short, thereby minimizing the increase in the basic length of the shock absorber itself. Adjustments are made at the tip of the end bolt, which is advantageous in terms of waterproofness, rust prevention, and dust resistance. The type that uses a piston rod to insert the rod has misalignment due to machining a long hole, and has poor workability and requires high workability and precision. These problems were solved by using a prevention mechanism. Since the housing 10 is welded to the upper end of the piston rod 3, a decrease in strength due to welding can be prevented, and the pressure resistance strength of the cylinder will not be adversely affected. If the end bolt 13 and cover cap 11 are integrally molded, no joining means such as welding is required, and assembly and processing are easy. A detent mechanism is provided within the space of the housing to position the rod and operating rod, thereby maintaining the position of the rod, operating rod, and selected orifice in position.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional side view of a shock absorber according to an embodiment of the present invention, Figs. 2 and 3 are side views and a plan view of the operating rod, and Figs. 4 and 5 are side views and a plan view of the rod. It is a diagram. 3...Piston rod, 10...Housing,
DESCRIPTION OF SYMBOLS 11... Cover cap, 13... End bolt, 25... Flange, 26... Hole, 30... Operation rod, 31... Pin, 38... Knob member.

Claims (1)

[Scope of Claims] 1 A vertical hole and a horizontal hole are bored in the piston rod to communicate two liquid chambers, and a cylindrical body is rotatably inserted into the vertical hole. The cylindrical body is rotatably driven by an external operation through the cylindrical body, and a plurality of orifices smaller than the lateral hole and each having a different inner diameter are spaced apart from each other, and one of these orifices is selectively moved to face the lateral hole by an external operation. In the shock absorber, a housing is fixed to the piston rod, a cover cap is fixed to this housing, and an end bolt is connected to the cover cap. An operating rod is rotatably inserted into the cover cap and the end bolt, the lower end of the operating rod is connected to the rod at an eccentric position, and a day tent mechanism is provided for positioning the rod and the operating rod within the space of the housing. Built-in shock absorber damping force adjustment device. 2. The rod is provided with a flange, a hole is provided at an eccentric position of the flange, and a pin is protruded from an end of the operating rod at an eccentric position, and the pin is fitted into the hole, as claimed in claim 1. damping force adjustment device for the shock absorber. 3. The shock absorber damping force adjusting device according to claim 1, wherein the cover cap and the end bolt are integrally molded. 4. The damping force adjusting device for a shock absorber according to claim 1, wherein an operating rod protrudes from the end bolt and a knob member is coupled to the operating rod.