JPS6221154Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a shock absorber used in a rear suspension of a two-wheeled vehicle or the like.

Hydraulic shock absorbers are used as shock absorbers for motorcycles, etc., and these hydraulic shock absorbers function as dampers by filling a cylinder with hydraulic oil and sliding a piston equipped with a damping force generator inside the cylinder. It's forcing me.

The above-mentioned hydraulic shock absorbers only have a buffering effect using incompressible oil as a medium, but in order to improve the ride comfort and handling of motorcycles, they combine gas and liquid with highly compressible gas sealed in the cylinder. have been proposed and put into practical use.

In such a combined air/liquid type buffer,
Its function as a damper is to cause oil to flow through a small diameter orifice drilled in the piston (or annular plate valve), creating a pressure difference before and after the orifice, so the energy lost here causes an increase in oil temperature. In motorcycles, oil temperature changes can reach around 150°C in shock absorbers used for off-road vehicles, and even on-road vehicles need to consider temperature changes up to around 100°C.

By the way, in conventional shock absorbers of this type, the change in oil temperature causes a change in the volume of the gas, and this causes a change in the spring characteristics of the gas, resulting in a change in ride comfort between the early and late stages of operation when operated for a long time. There is a problem with this.

The present invention was made to improve the above problems, and its purpose is to install a damper cylinder that generates heat due to damping force and a cylinder that functions as a gas spring side by side, and to attach each cylinder to a common mounting member. To provide a shock absorber which can be mounted and supported on the vehicle body side and wheel side.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a longitudinal sectional side view of the shock absorber according to the present invention.
1 is a first cylinder that performs the gas spring function, and the bottom of the cylinder body 2 is closed with a bottom piece 3.
An outer cylinder 4 is fitted into the upper part of the cylinder body 2 so as to be slidable in the axial direction.A large diameter part 4a is provided at the lower part of the outer cylinder 4, and a sliding guide 5 with respect to the cylinder body 2 is provided on the inner periphery of the large diameter part 4a. , an oil seal 6 is attached below this. The upper end of the outer cylinder 4 is closed with a lid 7.
The outer cylinder and the upper end of a piston rod 8 which runs vertically inside the cylinder body are fixed to the center of the cylinder, and a bound rubber 9 is attached to the lower side of the lid 7 around the upper end of the piston rod 8. A piston 10 is fixed to the lower end of the piston rod 8, and the piston 10 is slidably fitted into the cylinder body 2. A return coil spring 12 is installed between the lower surface of the piston 10 and the spacer 11 on the bottom piece 3. The piston 10 is provided with an axial oil passage 10a, a rebound rubber 13 is disposed on the upper surface of the piston 10 so as to surround the rod 8, and the upper end of the main body 2 is closed with a rod guide 14. ing. The main body 12 is filled with oil 15 up to a predetermined level for the purpose of lubrication during sliding of the piston 10 and rust prevention of the coil spring 12.
is not necessarily necessary.

The above oil level 15a in the outer cylinder 4 of the first cylinder 1
A gas chamber 16 is formed above, and gas such as air is sealed in the gas chamber 16, and the gas is supplied through an air valve 17 provided in a part of the lid 7 and a passage 18 provided in the lid 7.
The gas is supplied into the gas chamber 16 through the gas chamber 16.
A dust boot 19 made of a flexible elastic membrane material or the like is disposed surrounding the bottom piece 3 at the lower end of the main body 2 and the large diameter portion 4a at the bottom of the outer cylinder 4.

An axle side mounting bracket 21 is fixed to the bottom of the first cylinder 1, and the bracket 21 has a downward groove shape as shown in FIG. The bracket 21 is integrally provided with a rearward extending portion 22. On the other hand, the lid body 7 of the outer cylinder 4 is provided with a bracket part 23 extending upward, for example, integrally molded, and this part 23 is used as a vehicle body side mounting part, and this part is provided with a vehicle body side mounting hole 23a, and the outer cylinder 4 It has an upwardly extending portion 24 extending rearward.

A second cylinder 31 is arranged in parallel adjacent to the first cylinder 1, and the main body 3 of the second cylinder 31 is
The top and bottom of the main body 32 are closed by a bottom piece 33 and a lid 34, a piston 35 is slidably inserted into the main body 32, and a rod 36 is connected to the piston 35 at its upper end.
The piston 35 is provided with a valve 37 that opens the orifice during the compression stroke and a valve 38 that opens the orifice during the tension stroke to form a damping force mechanism. A rebound spring 39 is interposed between the lower surface of 35 and the bottom piece 33, and an oil seal 45 is further attached to the bottom piece 33. Hydraulic oil 40 is sealed inside the main body 32, and
A chamber 41 is formed above the piston rod, but this chamber 41 does not have a gas spring function and is used to absorb the amount of oil equivalent to the volume of the piston rod during the compression process.

The lower end portion of the piston rod 36 extending downward passes vertically into the mounting hole 22b provided in the upper piece 22a of the bracket extension portion 22, and a screw 3 is pre-inserted into this portion.
6a and tightened with nuts 25 and 26 so as to sandwich the upper piece 22a above and below. On the other hand, a supporting portion 42 is provided protrudingly on the lid body 34, and this portion 42 is attached to the left and right pieces 24a, 24 of the bifurcated extending portion 24 of the bracket 23.
A collar 43 is fitted around the middle or lower part of the support part 42, and a rubber bushing 44 with a flange is attached above the collar 43 for heat insulation so as to surround the collar 43. Threaded part 42
The washer 28 and the nut 2 are attached to the extending portion 24 via a.
Tighten at 7. Although the rubber bushing 44 is not necessarily required, considering that the external temperature of the second cylinder body 32 reaches 150°C to 160°C, it is preferable to insert it for heat insulation. If so, it is not limited to rubber. In addition, if it is an elastic body such as a rubber bush, cylinder 1,
31 manufacturing errors can be absorbed during assembly.

Next, to describe its function and effect, the first cylinder 1 and the second cylinder 31 are mounted on a common bracket 2.
1 and 23, they perform compression and tension movements as one unit, and obtain a buffering effect by the spring action of the gas in the gas chamber 16 of the first cylinder 1. Also, the second cylinder 3
A hydraulic damping force is obtained at the orifice by opening and closing valves 37 and 38 by sliding the piston 35 in the valve 1. By the way, as mentioned above, the oil temperature rises due to the hydraulic damping effect, but since the damping force cylinder is separate from the air spring cylinder and is defined in parallel, heat propagation to this cylinder is suppressed, and the cylinder Heat conduction is blocked and suppressed by the gap between the two, and furthermore, the heat propagated from the cylinder 31 via the bracket 23 is blocked by the heat insulating part 44, and the heat due to the hydraulic damping action is conducted to the air spring side. will be blocked and suppressed as much as possible.

Although the embodiments have been described in detail above, the damping force side cylinders may be arranged vertically in reverse, the hydraulic damping force mechanism is optional, and furthermore, as described above, the oil in the air spring side cylinder is not necessarily required.

As is clear from the above, according to the present invention, in a shock absorber that uses both gas and liquid, the heat conduction to the air spring side of the heat generated due to the hydraulic damping action is blocked and suppressed as much as possible.
It suppresses changes in the spring characteristics on the gas side to obtain stable gas spring characteristics, prevents changes in ride comfort between the early and late stages of operation, maintains a constant stable ride comfort and cushioning performance, and In addition to being advantageous in terms of safety, it has many advantages such as being able to be achieved simply by arranging the gas springs and the damping force generators side by side so that they can be integrally supported.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a longitudinal sectional side view of the buffer, Fig. 2 is a plan view of the same, and Fig.
The figure is a view of the main parts in the three directions of the arrows in FIG. 1. In the drawings, 1 is a cylinder device for a gas spring, 10 is a piston, 6 is a return spring, 16 is a gas chamber, 8 is a rod, 31 is a cylinder device for damping force generation, 35 is a piston, and 37 and 38 are damping force generation mechanisms. , 36 are rods, and 21, 22, 23, 24 are mounting members.

Claims (1)

[Claims for Utility Model Registration] In a two-wheeled vehicle or the like in which a shock absorber having two cylinder devices arranged side by side is suspended between the vehicle body and the axle, the first cylinder device is filled with gas and one end extends in the axial direction. A gas spring function is generated by the reciprocating movement within the cylinder of the piston, which is equipped with a rod that extends in the axial direction, and a second cylinder device is filled with hydraulic oil, and the cylinder of the piston is equipped with a rod that extends in the axial direction at one end. one end of the cylinder of each cylinder device and one end of the rod are connected and integrated by a common mounting member, and one end of the cylinder of one of the two cylinder devices is protruded from one end of the cylinder. , and a collar is fitted into the support portion attached to the mounting member, and a heat insulating material such as an elastic body is interposed between the collar and the mounting member to surround the collar and block heat generation due to hydraulic damping action. A vehicle shock absorber characterized by being equipped with a shock absorber.