JPS6027743Y2 - Shock absorber damping force adjustment device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a damping force adjusting device for a shock absorber used in a vehicle or the like.

A shock absorber is attached to the front fork of a two-wheeled vehicle, for example, and suppresses the movement of the suspension spring. By quickly damping vibrations, shock absorbers reduce shock on rough roads and improve tire grounding, improving handling stability. It is one of the important parts of a vehicle.

In high-speed on-road vehicles (usually road-driving motorcycles), the damping force of the shock absorber has a sensitive effect on handling stability, so it is necessary to adjust it according to driving conditions such as loaded weight and road surface conditions. .

In this case, the damping force of the shock absorber is adjusted by providing a bypass passage for the orifice through which the pressure-side hydraulic oil flows, and by varying the opening area of this bypass passage.

A shock absorber damping force adjustment device that has been commonly used in the past is composed of an opening area variable mechanism that changes the opening area of the bypass passage, and a positioning mechanism that maintains the opening position of this opening area variable mechanism. There is.

However, the damping force adjustment device having the above configuration is extremely complicated because it uses a variable hole orifice, etc. in the variable opening area mechanism, and also has a positioning mechanism to maintain the opening position of the variable opening area mechanism. Since this requires a separate component, it has various drawbacks, such as being disadvantageous for miniaturization and being expensive.

Therefore, the present invention provides a rotary valve having multiple orifice holes with different opening areas in the bypass passage of the shock absorber, and also uses orifice holes that are not used to generate damping force to perform positioning. Provided is a damping force adjustment device for a shock absorber that can be made smaller and lower in price.

Hereinafter, the shock absorber damping force adjusting device according to the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a cutaway sectional view of essential parts showing an embodiment of the shock absorber damping force adjustment device according to the present invention. It has a cylinder 1 with which a piston 5 provided in the cylinder slides.

The inner and outer cylinders 3 are connected through a passage 4 provided in a part of the cylinder 1.
, 2 and an oil chamber B in the cylinder 1 are in communication with each other.

During the compression operation of the shock absorber, part of the oil in the oil chamber A flows into the oil chamber above the piston 5, and at the same time, the intrusion volume of the inner cylinder 3 flows into the oil chamber B through the passage 4.

Also, the oil chamber A expands when the shock absorber extends.
The oil in the oil chamber B is taken in through the passage 4.

Therefore, the rotary valve 4 provides resistance to the flow of hydraulic oil when the shock absorber is compressed and expanded, thereby obtaining a damping force.

On the other hand, at one end of the outer cylinder 2, that is, at the compression end side of the piston 5, there is provided a damping force adjustment section 6 whose outer periphery is partially thickened.

This damping force adjustment 6 is made by a hole 7 opened from the outer periphery to reach the oil chamber A, and a hole 8 which also communicates from the outer periphery to the oil chamber B.
A hole 9 is formed to reach the hole 7, and a hole 10 is formed to pass through the hole 9 laterally and communicate with the hole 7.

Blind plugs 11 and 12 are press-fitted into the outer opening ends of the holes 7 and 10, respectively, to close them.

On the other hand, a rotary valve 14 sealed by an O-ring 13 is inserted into the hole 9, and its distal end engages with a step 15 in the hole 9, and its outer end is prevented from being removed by a snap ring 16. .

In this case, the rotary valve 14 is a cylindrical body whose outer end is closed, and orifice holes 17 to 19 are formed at 90° intervals on its outer periphery.

The orifice holes 17 to 19 have a diameter of 17>
19, and is formed to be substantially coaxial with the hole 10 when the rotary valve 14 rotates.

Therefore, holes 7, 10 . Orifice holes 17 to 19 of rotary valve 14 facing hole 10, rotary valve 1
4 and the hole 8 are the passage 4 of the shock absorber 1.
This constitutes a bypass passage for hydraulic oil.

Reference numeral 20 is a steel ball whose one end is pressed against the surface of the rotary valve 14, that is, the orifice hole, by a compression spring 21 that engages with the blind plug 12, and prevents rotation of the rotary valve 14 and closes the orifice holes 17 to 19.
It constitutes a positioning member that determines the position of.

In the shock absorber damping force adjusting device configured as described above, when an external force is applied to the shock absorber 1 with the rotary valve 14 set to the state shown in the figure,
The hydraulic oil in the oil chamber A is compressed by the piston 5.

This compressed hydraulic oil in the oil chamber A is supplied to the oil chamber B via the main passage passing through the passage 4, and a damping force is generated by resistance based on a predetermined constant opening degree of the passage 4. .

On the other hand, since the orifice hole 17 with the largest diameter provided in the rotary valve 14 is located in the bypass passage, the hydraulic oil in the oil chamber A is supplied to the oil chamber B via the orifice hole 17 and the hole 8. be done.

Therefore, in this state, a resistance corresponding to the sum of the openings of the passage 4 and the orifice hole 17 is applied to the hydraulic oil, and a corresponding damping force is generated.

Since the rotary valve 14 has the largest diameter orifice hole 17 interposed in the bypass passage, the overall resistance is the smallest, and accordingly, the damping of the shock absorber 1 is also the minimum value in the adjustment range.

Next, insert a flathead screwdriver or the like into the groove 22 formed on the outer end of the rotary valve 14 and turn it 90 degrees to the right.
When rotated, the steel ball 2 is inserted into the orifice hole 18.
0 is inserted to determine the position.

In this case, the peripheral surface of the rotary valve 14 facing the hole 10 constituting the bypass passage becomes a portion P without an orifice hole as shown in FIG.

Therefore, the bypass passage is completely closed by the P section of the rotary valve 14.

As a result, the only passage connecting the oil chamber A and the oil chamber B is the main passage passing through the passage 4, and the maximum damping force is generated due to the resistance based on the predetermined opening degree of the passage 4.

Next, when the rotary valve 14 is further rotated 900 turns to the right, the steel ball 20 is dropped into the orifice hole 17 and positioned, and the orifice hole 19
faces the hole 10 for the bypass passage.

Therefore, the opening degree of this bypass passage is the orifice hole 19.
Therefore, a moderate damping force will be generated as a whole.

- In this way, by rotating the rotary valve 14, the opening degree of the bypass passage is adjusted in three steps every 90 degrees, and the unused orifice holes 17 to 19 are utilized to ensure reliable positioning. It is done.

In this case, when the rotary valve 14 rotates,
After the steel ball 20 rides on the circumferential surface of the rotary valve 14, it is dropped into the next orifice holes 17 to 19, so the steel ball 20 moves in the direction in which the spring 21 is biased, corresponding to the opening of the orifice hole. It turns out.

Therefore, when the steel ball 20 is brought close to the inner diameter of the hole 10, there is no escape route for the oil that has entered the space between the blind stopper 12 and the steel ball 20, and the steel ball 20 can be moved smoothly. It may disappear.

In such a case, a positioning member 23 having an oil passage is used as shown in FIG.

This positioning member 23 has a cylindrical shape, and has a tapered surface 24 formed at its tip.

In this case, the diameter of the tip is made such that it can be inserted into any of the orifice holes 17 to 19 provided in the rotary valve 14 and engaged with the tapered surface 24.

Further, a flat surface 25 is formed on two opposing surfaces of the positioning member 23, and a space 26 is formed between the flat surface 25 and the inner wall of the hole 10.

When using the positioning member 23 configured in this way, since the space 26 is always provided between the inner wall of the hole 10 and the positioning member 23, this space 26 constitutes an oil passage and is used for positioning. To smoothly move a member 23.

In the above embodiment, three orifice holes are provided around the rotary valve, but the present invention is not limited to this. It is not limited to a number.

Further, in the above embodiment, only the case where the positioning member is provided at a position facing the bypass passage has been described, but the present invention is not limited to this, and the orifice of the rotary valve is located in the bypass passage. The positioning member may be disposed at a position facing the unused orifice hole of the rotary valve in this state.

As explained above, the present invention controls the opening degree of the bypass passage by interposing a rotary valve having a plurality of orifice holes with different opening areas in the bypass passage of a shock absorber, and also controls the opening degree of the bypass passage. Since the rotary valve is positioned by inserting a positioning member into the rotary valve, the opening adjustment mechanism of the bypass passage becomes extremely simple compared to the conventional structure. Since positioning can be performed using an unused orifice, it has the excellent effect of providing an inexpensive damping force adjustment device for a shock absorber that is suitable for downsizing.

[Brief explanation of drawings]

Fig. 1 is a cutaway sectional view of essential parts showing an embodiment of the shock absorber damping force adjustment device according to the present invention, Fig. 2 is a sectional view of the orifice hole of the rotary valve shown in Fig. 1, and Fig. 3 4 is a sectional view of a main part showing another embodiment of the damping force adjusting device for a shock absorber according to the present invention, and FIG. 4 is a sectional view of a positioning member portion shown in FIG. 3. 1... Shock absorber, 2, curved outer cylinder, 3
...Inner cylinder, 4...Passage, 5...
Zeston, 6... Damping force adjustment section, 7-10...
... Hole, 11, 12 ... Blind plug, 14 ...
... Rotary valve, 7-19 ... Orifice hole, 20 ... Steel ball, 21 ...
... Spring, 23 ... Positioning member, 2
4...Tapered surface, 25...Flat surface, 26
······space.

Claims (1)

[Scope of utility model registration request] A bypass passage is formed that bypasses the passage that communicates the lower oil chamber of the piston that slides in the cylinder and the oil chamber inside the cylinder, and by changing the opening area of this bypass passage, the damping force can be adjusted according to operating conditions. In the damping force adjustment device for a shock absorber, a rotary valve having a plurality of orifice holes having different opening areas is interposed in the bypass passage, and the rotary valve is engaged with an unused orifice hole that does not face the bypass passage. A damping force adjusting device for a shock absorber, characterized in that a positioning member is provided so as to adjust the damping force of a shock absorber.