JPS6221160Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a damping force adjusting device for a shock absorber that can adjust the damping force in response to an externally operated amount.

As a conventional shock absorber damping force adjusting device, for example, the one shown in FIG. 1 is known. To explain this, in the same figure,
1 is a cylinder, and inside this cylinder 1 is a piston 2.
A piston rod 3 having a diameter is inserted so as to be slidable left and right. This piston rod 3 is provided with a horizontal hole 6 and a vertical hole 7 that communicate with left and right liquid chambers 4 and 5 divided by the piston 2, and these holes 6 and 7 form an orifice. The piston rod 3 passes through the center of the bearings 8, 9 and an oil seal 10 which fluidly seals the upper end of the cylinder, and is fixed to an external support member 11 as will be described later.

A free piston 12 is loosely fitted below the cylinder 1 to define a gas chamber 13 below, and the cylinder bottom 14 is connected to the wheel side via a bracket 15.

A guide hole 17 is bored in the piston 3 in the axial direction, and a push rod 16 is inserted into the guide hole 17.
is slidably inserted into the rod 16, and a truncated conical tip 18 fixed to the lower end of the rod 16 projects into the horizontal hole 6 to change the opening area of the horizontal hole 6.

The piston rod 3 is screwed into a ring-shaped support member 11, and the screwed state is firmly held by a lock nut 19. A ring-shaped guide member 2 is attached to the left outer periphery of the support member 11 via a threaded portion 20.
1 are screwed together, and when the guide member 21 is rotated, the guide member 21 is guided by the support member 11 and moves in the axial direction. An outer cylinder 22 extends from the right outer periphery of the guide member 21, and a head cover 23 is connected to the left outer periphery of the guide member 21 via an O-ring 24 having a large frictional resistance.

There is a space 25 between the support member 11 and the guide member 21.
is formed in the upper part 11a of the support member 11 at the center of the end of the support member 11 and the space 2
A hole 26 opposite to 5 is bored in the vertical direction, and this hole 2
A pin serving as a stopper 27, which is locked at the center of the guide member 21, is movably fitted into the inside of the guide member 6.

The push rod 16 protrudes from the piston rod 3 while being supported by a bearing 28.
The tip of the rod 16 is always brought into contact with the center of the stopper 27 by a snap ring 29 as a spring receiver provided at the right end of the piston rod 6 and a spring 30 interposed between the piston rods 3.

A plurality of notches 31 facing in the axial direction are formed on the outer periphery of the support member 11, and a groove 32 is bored in the radial direction in the guide member 21, and a spring 3 is inserted into the groove 32.
The locking ball 34 pressed at step 3 is inserted. This ball 34 selectively fits into one of the notches 31 when the guide member 21 is rotated, so that the relative rotational position of the support member 11 and the guide member 21 does not easily shift at this time. . The positions of the notches 31 of the support member 11 are made to correspond to numbers or other marks provided on the outer cylinder 22, the head cover 23, or other external positions that are easy to detect, so that when a ball 34 is engaged with a certain notch 31, If you want to obtain the desired damping force, or if you want to further strengthen or weaken the damping force, rotate it to another display position.
The engagement position of the ball 34 can be changed.

A spring pin or a set screw serving as a stopper 35 is installed on the guide member 21 so as to protrude laterally, and a skirt portion 36 is provided to extend from the head cover 23 to the right by an arbitrary width. When rotated to a certain position, this skirt portion 36 abuts against the stopper 35 to prevent further rotation. The method of displaying the damping force is that a number indicating its strength is written on the outer periphery of the outer cylinder 22, and an arrow corresponding to this number is written on the skirt portion 36.
A predetermined damping force can be selected by arranging the arrow and the number opposite to each other. The center part of the head cover 23 fits into the stepped part of the upper part of the support member 11 without play, and upper mounting bolts 37 are welded to the upper surface of the head cover 23. are firmly fixed and maintain a concentric relationship with the support member 11.

By the way, in such a damping force adjustment device, a detent mechanism (positioning mechanism) is constituted by the locking ball 34 pressed by the spring 33 and the notch 31 of the guide member 21, and the amount of movement of the tip 18 is determined by the pitch of the threaded portion 20. It is determined by Therefore, the number of component parts of the detent mechanism increases, which increases the cost, and it is also necessary to increase the number of rotations of the guide member 21 relative to the unit movement of the tip 18. That is, there was a problem in that the operation for adjusting the opening area of the horizontal hole 6 was troublesome and time consuming.

On the other hand, as shown in FIG. 2, two triangular protruding cam protrusions 21a are arranged in series on the side of the guide member 21 in contact with the pin 27, as shown expanded in FIG. 3. is provided. In this damping force adjustment device, the guide member 21 is
By rotating the range, the pin 27 is urged against the spring 30 along the inclined surface of the cam projection 21a, and the opening area of the horizontal hole 6 by the tip 18 is efficiently adjusted. Therefore, the adjustment work is not troublesome. Furthermore, since the threaded portion 20 is not required as described above, the guide member 21 does not advance or retreat relative to the support member 11, and the notch 31 is made into a simple hole instead of a long groove, simplifying the machining work. There are advantages to

However, even with such a damping force adjustment device, the mechanism for advancing and retracting the push rod 16 is
The above detent mechanism is required, and the number of parts to be assembled for this purpose increases, making it difficult to realize cost reduction.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a damping force adjusting device for a shock absorber that simplifies the detent mechanism, has a small number of parts, can achieve low cost, and has excellent operability.

To achieve this objective, the structure of the present invention is such that a piston rod is slidably inserted into a cylinder via a piston, two liquid chambers are defined within the cylinder by the piston, and two liquid chambers are defined within the cylinder by the piston.
In a shock absorber damping force adjustment device, a damping force adjustment device for a shock absorber is provided with a movable push rod that forms a hole that communicates with two liquid chambers and adjusts the opening area of the hole, and the displacement of the push rod can be adjusted by external operation. A pin that is freely movable in the axial direction and whose rotation is restricted is supported by a spring at the end, and a guide member is rotatably arranged around the outer periphery of the piston rod, and a guide plate is integrally connected to this guide member. The guide plate is provided with an inclined surface and a cam projection having a plurality of grooves formed in the middle of the inclined surface, and the pin is selectively engaged with one of the grooves while slidingly contacting the inclined surface. It is characterized by the fact that

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

FIG. 4 is a sectional view showing the shock absorber damping force adjusting device of the present invention, and since the internal structure of the cylinder 1 and the mounting structure of the push rod 16 are substantially the same as those shown in FIG. Duplicate explanation of the configuration will be omitted. In FIG. 4, reference numeral 41 denotes a support member screwed onto one end of the piston rod 3, and a mounting bolt 42 is integrally connected to the end of this support member 41. Further, the support member 41 has an elongated hole 44 continuous with the cylindrical hole 43, and both ends of a pin 45 connected to the end of the push rod 16 are inserted through the elongated hole 44. Reference numeral 46 denotes a holding plate fixed to the support member 41 with a lock nut 47. A spring 48 is interposed between this holding plate 46 and the pin 45, and the pin 45 is always biased to the left of the elongated hole 44. has been done. Reference numeral 49 denotes a ring-shaped guide member integrated with the outer cylinder 22. The right end of this guide member 49 is in sliding contact with the surface of the holding plate 46, and a ring-shaped guide plate 50 is also provided at the left end opening of the guide member 49. is installed. The guide plate 50 is provided with two continuous ring-shaped inclined cam projections 51 as shown in FIGS. 5 and 6, and a plurality of grooves 5 are formed on the inclined surface of the cam projection 51.
2 is drilled. The inclined surface of this cam protrusion 51 comes into sliding contact with the pin 45, and the pin 45 slides into the groove 5.
2, the guide member 49,
The rotational position of the outer cylinder 22 is maintained, and the amount of protrusion and retraction of the push rod 16, i.e., the horizontal hole 1 of the piston rod 3, is maintained.
6 is maintained at a predetermined amount corresponding to the height of the groove 52. Note that 53 is a head cover.

In the damping force adjustment mechanism having such a configuration, when the outer cylinder 22 is rotated, the guide plate 50 is rotated in the same direction via the guide member 49, and at this time, the pin 45 moves on the inclined surface of the cam projection 51. It fits into the groove 52. In this case, the pin 45 moves from one groove 52 to another groove 52 and fits there, and the height position in the axial direction is displaced.
The push rod 3 that abuts is also displaced in either the left or right direction. As a result, the opening area of the horizontal hole 6 by the tip 18 is adjusted, and the piston 2 moves leftward or rightward in response to a liquid flow resistance corresponding to the opening area, thereby exhibiting a damping effect.

In addition, in the rotation operation of the outer cylinder 22, since one of the grooves 52 is elastically engaged with the pin 45, the adjustment of the protrusion and retraction of the push rod 16 and the positioning action of multiple stages are performed at the same time.
Therefore, the configuration of the detent mechanism is simplified,
It is possible to significantly reduce the cost of the damping force adjustment mechanism.

FIG. 7 shows another embodiment of the damping force adjustment mechanism. This uses the shock absorber shown in Fig. 4 upside down, and for this reason, the outer cylinder 22 is omitted to prevent dust and water from entering between the cylinder 1 near the lower part of the spring and the guide member 49. As shown, the space between them is sealed with a bellows-shaped rubber cylinder 54. The rest of the configuration is the same as that shown in FIG.

As described above, according to the present invention, the following effects can be obtained.

Since a plurality of grooves are provided on the inclined surface of the cam projection that drives the push rod, the grooves serve as a detent mechanism for the pin, and the drive member and detent mechanism can be constructed as a single component. Therefore,
There is no need to separately provide a detent mechanism in addition to the drive member as in the conventional case, the detent mechanism can be simplified, the number of parts is small, and costs can be reduced.

Since the pin moves along the inclined surface of the cam projection, the number of rotations of the guide member may be small relative to the unit movement of the push rod, resulting in good operability and speed.

Since the grooves that also serve as the detent mechanism are formed on the inclined surface of the cam protrusion, the height of each groove can be set to the height along the inclined surface.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional shock absorber damping force adjustment device, Fig. 2 is a sectional view showing another conventional example, and Fig. 3 is a developed view of the main parts of this other conventional example.
Fig. 4 is a sectional view showing one embodiment of the damping force adjustment device of the present invention, Fig. 5 is a developed view of the main parts, Fig. 6 is a perspective view of the guide plate, and Fig. 7 is a diagram showing another embodiment. FIG. 1... Cylinder, 2... Piston, 3... Piston rod, 4, 5... Liquid chamber, 6... Orifice, 16... Push rod, 45... Pin, 4
6... Holding plate, 48... Spring, 49... Guide member, 50... Guide plate, 51... Cam protrusion, 52... Groove.

Claims (1)

[Claims for Utility Model Registration] (1) A piston rod is slidably inserted into the cylinder via a piston, two liquid chambers are defined within the cylinder by the piston, and two fluid chambers are defined within the cylinder by the piston. In a damping force adjustment device for a shock absorber, a damping force adjustment device for a shock absorber is provided with a movable push rod that forms a hole communicating with a liquid chamber and adjusts the opening area of the hole, and the displacement of the push rod can be adjusted by external operation. A pin that is freely movable in the axial direction and whose rotation is restricted is supported by a spring, and a guide member is rotatably disposed around the outer periphery of the piston rod, and a guide plate is integrally connected to the guide member. The guide plate is provided with an inclined surface and a cam projection having a plurality of grooves formed in the middle of the inclined surface, and the pin is selectively engaged with one of the grooves while slidingly contacting the inclined surface. Shock absorber damping force adjustment device. (2) The shock absorber damping force adjusting device according to claim 1, wherein a spring is interposed between the pin and the fixed holding plate. (3) The shock absorber damping force adjusting device according to claim 1, wherein the groove and the pin also serve as a detent mechanism. (4) A shock absorber damping force adjusting device according to claim 1, wherein an outer cylinder is connected to a guide member.