JPS6122073Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a damping force adjustment device for a front fork in a motorcycle or the like.

In general, motorcycles are equipped with front forks on both sides of the front wheels as shock absorber means, but these front forks are designed to improve riding comfort depending on the weight of the rider, the weight of luggage, and road conditions. It is preferable to make the damping force variable each time.

One of the devices configured to adjust this damping force is disclosed in, for example, Japanese Utility Model Application Publication No. 114252/1983. This damping force adjustment device has an oil hole in a seat pipe, a damping force adjustment pipe inserted into this seat pipe, and one of multiple orifices with different diameters bored in the circumferential direction of this adjustment pipe. The orifice is selected and placed opposite the oil hole to obtain a damping force according to the diameter of the selected orifice, and the adjustment pipe is rotated via an adjustment rod inserted above the seat pipe. However, in such a damping force adjustment device, since the adjustment rod is a rotating operation member, the adjustment rod requires a certain degree of rigidity, and in order to achieve this rigidity, it must be made thicker, which increases the weight. The disadvantage is that it increases costs.

Therefore, an object of the present invention is to provide a damping force adjusting device for a front fork that does not require much rigidity of the adjusting rod, can have a small diameter, is lightweight, and can reduce costs.

For this purpose, the present invention fixes a rotary valve, inserts an adjusting rod rotatably into the rotary valve, and selectively connects a notch provided in the adjusting rod to one of the plurality of orifices on the rotary valve side. It is characterized by being connected to.

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

In Figures 1 to 3, the front fork F has an inner tube 2 connected to the vehicle body via a piston 4 and a seal 21 slidably inserted into an outer tube 1 connected to the wheel side. An oil hole rod 9 and a hollow cylinder 3 are fixed upright from the center of the lower end of the tube 1, and the cylinder 3 extends into the inner tube 2, and the large diameter portion 5 at the upper end is connected to the inner periphery of the inner tube 2 through a seal portion 6. It is designed to come in sliding contact with the An upper oil chamber 10 and a lower oil chamber 11 are defined within the inner tube 2 and outer tube 1 by a piston 4, and these oil chambers 10 and 11 are opened and closed via a passage provided in the piston 4 and a valve mechanism 12. It is becoming more and more common.
An oil chamber 13 is defined within the cylinder 3, and a volume compensation gas chamber 35 is defined above the oil chamber 13 for compensating for changes in oil amount corresponding to the volume of movement of the inner tube 2.

A through hole 7 is bored in the lower part of the cylinder 3, and the two oil chambers 11 and 13 can communicate with each other through the through hole 7.

The oil hole rod 9 is a concave portion 15 at the lower end of the outer tube 1.
This oil hole rod 9 forms a collision mitigation mechanism that fits with the lock piece on the inner tube side and restricts the discharge flow of the oil chamber 11 when the inner tube 2 reaches near the maximum compression. Further, the lower part of the cylinder 3 is fitted into the oil hole rod 9, and a bolt 17 is screwed into the cylinder 3, the oil hole rod 9, and the lower part of the outer tube 1 via a screw 18, and the lower end flange 20 of this bolt 17 is It is hooked to the lower end step part of the outer tube 1 via a packing 19. Therefore, when the bolt 17 is rotated and the bolt 17 is screwed into the cylinder 3 via the screw 18, the cylinder 3 and the bolt 17 are screwed together.
are pulled together, and the cylinder 3, together with the oil hole rod 9, is pressed against the central recess 15 at the lower end of the outer tube 1, and conversely, the flange 20 of the bolt 17 is pressed against the stepped portion of the outer tube 1, and the cylinder 3 is pressed together with the oil hole rod 9. is combined with

A bracket 36 is provided on the outer periphery of the outer tube 1 so that a wheel can be mounted thereon.
Further, a spring 22 is interposed between the upper wall of the inner tube 2 and the upper end of the hollow cylinder 3 to constantly urge the inner tube 2 upward.

For example, three oil holes 14 are bored in the upper large diameter portion 5 of the hollow cylinder 3, and these oil holes 14 are connected to the upper oil chamber 1.
0 to the hollow cylinder 3 via the rotary valve 30
It is designed to communicate with the oil chamber 13 inside.

It is preferable that a spring, for example, be interposed as a cushion member in the upper part of the piston 4 to prevent collision when the piston 4 is extended.

Furthermore, a rotary valve 30 consisting of a hollow pipe-shaped valve body 31 is fixed within the large diameter portion 5 via a pin 10.

In the center of the valve body 31, one through hole 33 having a circular cross section is provided in the axial direction, and one or more holes 33a are provided on the outside of this through hole 33, and a plurality of orifices a having different inner diameters are provided in the radial direction. b, c...n are bored, and these orifices a, b, c...n open into each through hole 14, and one of them opens into the through hole 3.
By opening the orifice 3, a rebound damping force corresponding to the selected inner diameter of the orifice can be obtained. In this case, since the through hole 14 is provided in the large diameter portion 5, the damping force generating mechanism can be easily installed in the large diameter portion 5 opposite to the through hole 14, and the hollow cylinder 3 The strength can also be maintained.

In the rotary valve 30, the orifices a and b, b and c, . . . are formed at equal intervals, for example, at 90 degrees.

A rotating body 50 is rotatably inserted above or below the rotary valve 30 in the large diameter portion 5,
A detent mechanism 34 is incorporated in the rotary body 50, and an adjustment rod 32 having a semicircular cross section is fitted in the center of the rotary body 50 in the axial direction.
One or more through holes 51 facing the side through holes 33a are bored in the axial direction.

The detent mechanism 34 has positioning holes A, B, C... drilled in the large diameter portion 5 of the hollow cylinder 3 in the radial direction.
Drill N, and set the distance between holes A and B, B and C, etc., for example.
Orifices a and b are formed at equal intervals of 90 degrees.
. . . n and the positions of holes A, B . . . N can correspond to each other.

A hole is bored in the rotating body 50 in the radial direction, and a locking ball 37 and a spring 38 are interposed in this hole. , B...N so that the adjustment rod 32 can be positioned.

The upper end of the rotating body 50 is prevented from coming out upward from the hollow cylinder 3 by a stopper 39.

The lower part of the adjustment rod 32 is rotatably inserted into the central hole 33 in the rotary valve 30, and since the adjustment rod 32 has a semicircular cross section, the cutout surface of the adjustment rod 32 and the inside of the hole 33 A space is always formed between the circumferential surfaces along the axial direction.

Therefore, by rotating the adjusting rod 32, this space is opened or closed with any of the orifices a, b...n, and a damping force corresponding to the opened orifice is generated.

A sleeve 40 is fitted to the upper end of the inner tube 2 via a seal 41 , and an adjuster star boss 42 is rotatably held within this sleeve 40 via a seal 44 and a stopper 45 . The upper end of the adjusting rod 32 is fixed to the lower part of the adjusting rod 32 via a pin 43, and the adjuster star boss 4
2 rotates the adjustment rod 32.

A cap holding portion 46 is attached to the adjuster star boss 42.
extends upward, and this cap holding portion 4
Splines or knurling are carved on the outer periphery of 6, and an adjuster star cap 47 is connected via these splines or knurls, and the cap 47 can be attached and removed in the vertical direction, and when rotated, adjuster star boss 42, adjustment rod 32, etc. are designed to rotate in the same direction.

Marks such as numbers 1, 2, 3, 4, etc. are written on the top surface of the adjuster star cap 47, and the marks are formed at equal intervals of, for example, 60 degrees and unequal intervals of 180 degrees. The marks correspond to orifices a, b...n and holes A, B, C...N, respectively.

At the center of the adjuster star cap 47 is a screw 48.
are screwed together to prevent the cap 47 from coming off.

Next, we will discuss the operation.

In the above-mentioned front fork A, during compression operation, the piston 4 and the inner tube 2 descend,
Since the lower oil chamber 11 contracts, the oil discharged from the oil chamber 11 flows into the oil chamber 13 through the through hole 7, and the flow resistance of this through hole 7 generates a compression side damping force, and the oil from the passage of the piston 4 flows out into the oil chamber 13. Upper oil chamber 10 via valve 12
is discharged.

Also, in the extension operation, the piston 4 rises, the upper oil chamber 10 contracts, and the lower oil chamber 11 expands, but at this time, oil in the oil chamber 13 is sucked into the lower oil chamber 11 through the through hole 7 of the hollow cylinder 3. to prevent negative pressure. Also, the oil in the upper oil chamber 10 is supplied through the through hole 14 and orifices a and b.
...The oil chamber 13 via the through hole 33 from either of the n.
The damping force on the rebound side is generated by the flow resistance according to the diameter of this orifice.

When adjusting the damping force, rotate the adjuster star cap 47 so that the mark corresponding to the desired orifice faces the position display member, and the same amount adjustment rod 32 moves in the same direction via the boss 42 and rod 34. One of the orifices that rotates and corresponds to the mark is hole 3.
3, which generates a damping force depending on the diameter of the orifice. Also, at this time, the locking ball 37 of the detent mechanism 34 engages with the hole corresponding to the mark to maintain the position of the adjustment rod 32.

Next, FIGS. 4 to 6 relate to another embodiment of the present invention, in which the detent mechanism 34 is located within the boss 42, and substantially the same as in FIGS. 1 to 3.
Identical to the embodiment shown. Therefore, descriptions of the same mechanisms will be omitted.

That is, as shown in FIGS. 4 and 6, a spacer 55 is interposed between the boss 42 and the sleeve 40 and held by a knock pin 56, and holes P, Q corresponding to the orifices a, b...n are inserted into the spacer 55. ,R,S...
...N is drilled in the radial direction, and a day tent mechanism 34 consisting of a spring 38 and a ball 37 is placed inside the boss 42.
is included. Therefore, when the cap 47 is rotated, the boss 42 and the adjustment rod 32 are rotated, and at this time, the hole 33 faces one of the orifices a, b...n, so that a desired damping force can be obtained. On the other hand, in response to the rotation of the boss 42, the locking ball 37 fits into the hole facing the selected orifice among the holes P, Q...N, thereby positioning the adjustment rod 32.

In the case of the embodiments shown in FIGS. 1 to 3, the semicircular adjustment rod 32 is fitted to the rotating body 50 in the detent mechanism, so that when the adjustment rod 32 is rotated, this adjustment is performed. The acute angle part of the rod 32 is the rotating body 50
The sharp edge comes into contact with the hole of the adjusting rod 3, causing galling and biting, resulting in poor operability and impairing durability.However, in the embodiments shown in FIGS.
2 and the day tent mechanism 34 are separated, and the adjustment rod 32
Even if it has a semicircular cross section, there is no sharp edge contact, and the above-mentioned galling and biting phenomena do not occur.

As described above, the present invention rotatably inserts the adjusting rod 32 having a semicircular cross section into the circular through hole 33 in the valve body 31 of the rotary valve 30, and the through hole corresponds to the notch surface of the adjusting rod 32. 33 to orifice a, b...
... n can be selectively opened and closed, the adjustment rod 32 itself does not need to have great rigidity, and can therefore be formed thinly, reducing weight and cost. Further, since the rotary valve 30 is fixed and only the adjustment rod 32 and the detent mechanism 34 are rotated, the rotational operation force is relatively small, and the operability is improved.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of a front fork according to an embodiment of the present invention, FIG. 2 is a cross-sectional plan view taken along line A-A in FIG. 1, and FIG. 3 is a cross-sectional plan view taken along line B-B in FIG. , FIG. 4 is a longitudinal sectional front view of a front fork according to another embodiment of the present invention, and FIG.
FIG. 6 is a cross-sectional plan view taken along line C--D in FIG. 4. 1... Outer tube, 2... Inner tube, 3... Cylinder, 4... Piston, 5...
Large diameter part, 7...Through hole, 10, 11...Oil chamber, 30
... Rotary valve, 31 ... Valve body, 32 ... Adjustment rod, 33 ... Through hole, 42 ... Boss, a, b, c
...n...orifice.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) An inner tube is slidably inserted into an outer tube via a piston, and the upper large diameter portion of a hollow cylinder rising from the bottom of the outer tube slides into contact with the inner tube. The outer tube and the inner tube are divided into upper and lower oil chambers by a piston, and the upper oil chamber communicates with the oil chamber of the hollow cylinder through an oil hole and a rotary valve provided in the hollow cylinder, and the lower oil chamber The valve body of the rotary valve is fixed to the hollow cylinder at the front fork, which communicates with the oil chamber of the hollow cylinder through a through hole provided in the hollow cylinder. A through hole and a plurality of radial orifices opened in the through hole are bored, and one of the orifices is opened in the axial through hole with respect to the axial through hole. A damping force adjustment device for a front fork, in which an adjustment rod provided with a notched surface is rotatably inserted, and the upper end of the adjustment rod is connected to an adjuster star boss rotatably provided at the upper end of an inner tube. (2) The damping force adjusting device for a front fork according to claim 1, wherein the valve body is fixed within the large diameter portion of the hollow cylinder. (3) The front fork damping force adjusting device according to claim 1, wherein the adjusting rod is combined with a day tent mechanism. (4) The front fork damping force adjusting device according to claim 3, wherein the detent mechanism is provided within the large diameter portion of the hollow cylinder. (5) The damping force adjustment device for a front fork according to claim 3, wherein the daytent mechanism is provided in the upper boss interlocking with the adjustment rod.