JPH0138362Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a damping force adjustment device in a hydraulic shock absorber.

In hydraulic shock absorbers used in rear suspensions of two-wheeled vehicles, etc., it is desirable to be able to arbitrarily adjust damping force characteristics depending on road surface conditions, rider preference, and the like. For this purpose, the damping force can be increased by fitting the adjusting rod concentrically into the piston rod, exposing the lower end of the adjusting rod to the damping force generation mechanism of the piston, and rotating the upper end of the adjusting rod from the outside. There are things that are configured to be adjusted. There are various types of rotation operation means, but a pinion gear is fixed to the upper end of the adjustment rod, and a rack slidably provided in a housing attached to the upper end of the piston rod is meshed with the pinion gear. Means of rotating the adjusting rod via a pinion gear by externally manipulating the rack are generally well known. Conventionally, in this type of gear type ratchet mechanism, it has been difficult to set the rotation angle in one stroke of the rack.

This invention proposes a damping force adjustment device for a hydraulic shock absorber with the aim of solving the above-mentioned difficulties, and includes a connecting member having a disk shape having a central axis and having a lower end of the central axis fixed to the upper end of the adjustment rod; A pinion gear provided on the upper surface of the connecting member so as to be rotatably fitted around the center shaft, a permanent magnet held non-rotatably above the pinion gear, and a hole drilled in the pinion gear. A permanent magnet pin is fitted in the inner part, and a hole is provided in the connecting member, and the connecting member and pinion gear are integrated and separated by the magnetic force between the permanent magnet and the pin, making it easy to mesh with the pinion gear. The gist is that a ratchet mechanism is provided that rotates the connecting member by a predetermined angle in one stroke.

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

FIG. 1 is a partially longitudinal front view showing the main parts of a hydraulic shock absorber, in which 1 is a cylinder filled with oil;
A piston 2 is slidably fitted into the cylinder 1, and the piston 2 has an oil hole 3 and a disk valve 4 on its upper surface. A piston rod 5 supporting the piston 2 is tubular in shape, has an oil hole 6 on its side surface, has an open lower end, and communicates via an oil passage 7 with a valve chamber formed on the inner circumferential side of the lower end of the piston 2. . A valve 8 is rotatably fitted into the valve chamber, and is non-rotatably connected to the lower end of an adjusting rod 9 which is rotatably fitted into the piston rod 5. Further, the lower end of the valve chamber is closed and an oil hole 10 is eccentrically bored therein. FIG. 8 shows a sectional view taken along the line A-A in FIG.
13, 14, 15, and 16 are bored, and the orifice 16 and the oil hole 10 are in communication with each other. Therefore, during the compression stroke of this shock absorber, the valve 4 opens and the hydraulic oil in the lower oil chamber flows through the oil hole 3 to the upper oil chamber, so a relatively small damping force is obtained, and the expansion During stroke, the hydraulic oil in the upper oil chamber flows through oil hole 6, oil passage 7, orifice 16, and oil hole 10.
Since the damping force is generated by flowing into the lower oil chamber through the oil holes, the damping force can be adjusted by rotating the adjustment rod 9 to change the size of the orifice facing the oil hole 10. In this embodiment, damping force adjustment in the extension stroke has been described, but it goes without saying that the damping force adjustment can also be applied to the compression stroke.

In the above-mentioned hydraulic shock absorber, the piston rod 5
A support frame 19 and a nut 20 for fixing the spring receiver 17, the housing 18, and the spring receiver 17 are sequentially screwed onto the upper end, and the spring receiver 17 is connected to a spring receiver (not shown) provided on the outer periphery of the cylinder 1. A vehicle body suspension spring 40 is stretched between them. The housing 18 has its lower end fixedly supported by the upper end of the piston rod 5, and its mounting arm 21
is fastened to the support frame 19 via fixing screws 22. Reference numeral 23 denotes a mounting bracket, the lower end of which is attached to the support frame 19 on the outer circumferential side, and the lower end of which is attached to the nut 2 on the inner circumferential side.
The cylinder 1 is supported and fixed at the cylinder 1, and its upper part is attached to the vehicle body, and the lower end of the cylinder 1 is supported by an axle.

FIG. 2 shows an enlarged view of the housing 18, and FIG. 3 shows a sectional view taken along line BB in FIG. Inside the housing 18 are a connecting member 24 having a disk shape having a central axis, and a pinion gear 25 and a permanent magnet 26 which are sequentially provided on the upper surface of the connecting member 24 with the central axis rotatably fitted onto the outside. are fitted. The connecting member 24 has a lower end of its central axis coaxially fixed to the upper end of the adjustment rod 9. The pinion gear 25 is slidably provided in the housing 18 and is moved forward by external pressure.
A rack 27 is engaged, which is configured to move backward by being urged in the opposite direction by a return spring 26'. The permanent magnet 26 has a housing 1
8. A locking bolt 28 inserted from the outer wall is provided. Note that 29 is an O-ring, 30 is a positioning hole, and 31 is a pipe for introducing external pressure to the base end of the rack hole 27, which is attached to the housing 18 via a flange. FIG. 4 is an exploded perspective view showing the ratchet mechanism provided in the rack and pinion mechanism constructed as described above, in which a permanent magnet pin 33 is fitted into a hole 32 formed in the pinion gear 25. At the same time, a plurality of holes 34, 3 are formed at equal intervals in the circumferential direction of the upper surface of the connecting member 24.
5, 36, 37, 38, and 39 are arranged.
FIG. 5 is a plan view showing each member in FIG. 4, FIG.
FIG. 7 is an explanatory view showing the operating state of the ratchet mechanism. The operation of this damping force adjusting device will be described below, assuming that the permanent magnet 26, pinion gear 25, connecting member 24, and valve 8 are positioned as shown in FIGS. 5 and 8.

The pin 33 fitted into the hole 32 of the pinion gear 25 has an S pole at its upper end, and is connected to the permanent magnet 2.
6, a repulsive force is generated, and the lower end of the pin 33 fits into the hole 34 of the connecting member 24, as shown in FIG. Therefore, when the external pressure introduced from the pipe 31 acts on the base end of the rack 27 in the direction of the arrow, the rack 27 moves forward and is integrated with the pinion gear 25 through the pin 33. The connecting member 24 rotates counterclockwise. If rotated 60 degrees, pin 33 becomes permanent magnet 26
Since it faces the N pole side of the pin 33, an attractive force is generated and the pin 33
The lower end of the connecting member 24 separates from the hole 34 and the seventh
It will look like the figure. Therefore, when the external pressure is removed, the rack 27 moves back due to the spring reaction force of the return spring 26', and only the pinion gear 25 rotates 60 degrees clockwise and returns to its original position. Thus, one stroke of the rack 27 has been completed, but since the connecting member 24 has been rotated 60 degrees counterclockwise, the valve 8, which is integrated with the connecting member 24 through the adjustment rod 9, has also rotated 60 degrees, and the orifice is rotated 60 degrees. An orifice 15 instead of 16 communicates with the oil hole 10. When the rack 27 moves forward next time, the lower end of the pin 33 is connected to the connecting member 27.
The valve 8 is inserted into the hole 39 and operates in the same manner as described above.
Convert the orifice. As above, easy 2
Since the valve 8 can be rotated by 60 degrees in one stroke of 7 to freely select any orifice, good damping force adjustment can be performed. In this embodiment, the rotation angle of the rack 27 in one stroke was set to 60 degrees, but depending on the conditions such as the number of orifices provided in the valve, it may be possible to divide the rack into equal angles, such as 90 degrees, 120 degrees, and 180 degrees. The magnetic pole of the permanent magnet may be selected according to the set angle, and instead of the permanent magnet 26 divided into two parts, it may be set at a predetermined position on the non-magnetic disc 26' as shown in Fig. 5a. Permanent magnets 26″, 26 with N and S poles, respectively
may be buried. The external pressure introduced into the proximal end of the rack 27 may be either hydraulic pressure or pneumatic pressure, and the external pressure introduced into the base end of the rack 27 may be either hydraulic pressure or pneumatic pressure. There is no problem even if other means are used, such as configuring the rack 27 to move forward and backward by providing it. In addition, as a matter of course, the housing 18,
The connecting member 24, pinion gear 26, etc. are connected to the pin 33.
Made of non-magnetic material that does not affect the operation of the device.

As described above, this invention has a ratchet mechanism that makes it easy to set the rotation angle in one stroke of the rack, so the damping force can be adjusted very quickly and accurately. In addition, the above ratchet mechanism uses magnetic force between magnets, so it is compact and has excellent durability, and the damping force adjustment device made of this rack and pinion mechanism can be applied to various hydraulic shock absorbers. It has a great effect.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing one embodiment of this invention, Fig. 2 is an enlarged view of the main part of Fig. 1, and Fig. 3 is an enlarged view of the main part of Fig. 2.
Fig. 4 is an exploded perspective view showing the ratchet mechanism which is the main part of this invention, Fig. 5 is a plan view showing each member of Fig. 4, and Fig. 5a is a permanent magnet section. 6 and 7 are explanatory diagrams showing the operating state of the same ratchet mechanism, and FIG. 8 is a sectional view taken along the line AA in FIG. 1. 1...Cylinder, 2...Piston, 5...Piston rod, 8...Valve, 9...Adjustment rod,
10... Oil hole, 11, 12, 13, 14, 15,
16... Orifice, 18... Housing, 24
... Connecting member, 25 ... Pinion gear, 26,2
6″, 26…Permanent magnet, 27…Rack, 2
8... Locking bolt, 32... Hole, 33...
Pin, 34, 35, 36, 37, 38, 39...
hole.

Claims (1)

[Scope of utility model registration request] In a hydraulic shock absorber having a structure in which the damping force is adjusted by the rotation of an adjusting rod that is inserted into a piston rod, a connecting member is formed in the shape of a disk having a central axis, and the lower end of the central axis is fixed to the upper end of the adjusting rod. , a pinion gear which is sequentially provided on the upper surface of the connecting member with the central shaft rotatably fitted on the outside, and a housing that meshes with the pinion gear and is fixed to the upper end of the piston rod. A rack that is movably provided and moves forward and backward; a permanent magnet that is non-rotatably held above the pinion gear; a pin of the permanent magnet is fitted into a hole drilled in the pinion gear; During the forward stroke, the pin faces the same pole side of the permanent magnet and generates a repulsive force, and the lower end of the pin fits into the hole provided in the connecting member, uniting the pinion gear and the connecting member to rotate a predetermined angle. During the backward stroke of the same rack, the pin faces the opposite polarity side of the permanent magnet, creating an attractive force, the lower end of the pin separates from the hole in the connecting member, and only the pinion gear rotates in the opposite direction, returning to its original position. 1. A damping force adjustment device for a hydraulic shock absorber, comprising a ratchet mechanism configured to return.