JPH088361Y2 - Inverted front fork - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an inverted front fork that doubles as a shock absorber and a fork that is interposed between a vehicle body of a motorcycle or the like and an axle to damp vibrations from the road surface.

[Conventional technology]

A front fork of this kind is, for example, Jitsuko Sho 63-1662.
An upright front fork disclosed in Japanese Patent No. 8 is known.

In this front fork, the inner tube of the vehicle body is slidably inserted into the outer tube of the wheel side, the hollow rod stands up from the center of the lower part of the outer tube, and the upper piston of the hollow rod makes sliding contact with the inner circumference of the inner tube. An oil lock case with an oil lock chamber is provided inside the lower part of the tube, an oil hole rod is provided on the outer periphery of the lower end of the hollow rod, and the oil lock case gradually fits with the oil hole rod at the time of maximum compression and the oil lock pressure is increased. It is designed so that the cushion effect by

[Problems to be solved by the device]

However, in recent years, there has been a demand for the use of a so-called inverted front fork in which an outer tube is provided on the vehicle body side and an inner tube is connected to the wheel side due to the external appearance preference of the front forks and motorcycles to which the front forks are attached. Therefore, if it is attempted to use the upright front fork as it is as an inverted front fork, since the upper inside of the outer tube becomes a gas chamber for compensating the change in the oil amount during the expansion and contraction operation, the oil hole rod does not come into contact with the oil. No
There is a problem that the oil lock cannot be reliably performed.

Further, in the above-mentioned conventional structure, since there is a valve and an oil hole above the oil lock case, oil may leak from the valve and the oil hole, and a sufficient oil lock may not be effective.

Therefore, the object of the present invention is to allow the oil hole rod to come into contact with oil at the time of maximum compression, to prevent oil leakage, and to ensure the effect of the oil lock pressure, and also to allow the outer and inner tubes to slide smoothly. Is to provide an inverted front fork that can.

[Means for solving the problem]

In order to achieve the above object, the structure of the present invention is such that the inner tube of the wheel is slidably inserted into the outer tube of the vehicle body, and the lower piston portion of the hollow rod concentrically provided in the center of the outer tube is the inner tube. A suspension spring for biasing the hollow rod and the outer tube in the extension direction is interposed between the lower portion of the inner tube and the piston portion of the hollow rod, and a gas chamber and an oil chamber are defined inside the outer tube. In an inverted front fork, an oil lock case with an oil lock chamber is erected on the upper end of the inner tube, and an oil hole rod facing the oil lock chamber is provided on the outer circumference of the hollow rod, and the position of the oil hole rod is set. Is set below the oil level in the oil chamber in the outer tube at the time of maximum compression, and the outer tube and inner tube are A gap is provided between the, is characterized in that communicates with the oil chamber in the outer tube through a port provided with the gap on the upper and the oil lock case of the inner tube.

[Action]

At the time of compression, the oil hole rod rushes into the oil and fits into the oil lock case while in contact with the oil to generate the oil lock pressure and to make the cushion effective. In addition, oil is introduced into the gap through the port, allowing the inner and outer tubes to slide smoothly.

〔Example〕

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

Inner tube 2 on the wheel side is slidably inserted into outer tube 1 on the vehicle body side, outer tube 1 is connected to the vehicle body side via brackets 15 and 16, and inner tube 2 is connected to the axle via axle bracket 18. Has been done.

A hollow rod 8 is bolted to the upper part of the outer tube 1.
The hollow rod 8 is connected to the inner circumference of the inner tube 2 through a piston ring 20. The hollow rod 8 is connected to the inner tube 2 through a piston ring 20.

A suspension spring 21 is interposed between the lower portion of the inner tube and the piston portion 19 to constantly urge the hollow rod 8 and the outer tube 1 in the extending direction.

A cylindrical oil lock case 5 having an oil lock chamber 6 provided inside the upper end of the inner tube 2 is erected, and the oil lock case 5 is held by caulking the tip of the inner tube 2.

A piston 22 is provided inside the lower portion of the oil lock case 5 and slidably contacts the outer periphery of the hollow rod 8, and an oil chamber 23 is defined between the piston 22 and the piston portion 19 of the hollow rod 8.

A reservoir composed of a gas chamber 25 and an oil chamber 26 is defined in the outer tube 1 above the oil lock case 5, and the oil surface of the oil chamber 26 extends from the most extended position shown in FIG. To rise.

The inner oil chamber 2 and the hollow rod 8 have a lower oil chamber.
28 and an upper gas chamber 27 are partitioned, and the oil chamber 28 communicates with the oil chamber 23 via an orifice 29 provided in the hollow rod 8.
The gas chamber 27 and the oil chamber 28 communicate with the reservoir via a port 30 provided in the hollow rod 8.

A cushion spring 24 is provided in the oil chamber 23 so that the cushion at the time of extension is effective.

An oil hole rod 9 is fixed to the outer periphery of the upper portion of the hollow rod 8 via a snap ring 10, and the oil hole rod 9 faces the oil lock chamber 6 of the oil lock case 5.

A step portion 13 is formed on the inner circumference of the upper portion of the outer tube 1, and the step portion 13 serves as a stopper which engages with the upper end caulked portion 14 of the inner tube 2 at the time of maximum compression.
However, as a stopper, the oil hole rod 9 is opposed to the caulking portion 14.
A flange may be formed at the upper end of the.

A lubrication gap 3 is formed between the outer circumference of the inner tube 2 and the inner circumference of the outer tube 1, and this clearance 3 is provided on the upper portion of the inner tube 2 and on the upper portion of the oil lock case 5. 7 to communicate with the inlet of the oil lock chamber 6 and the oil chamber 26.

At the time of extension, the hollow rod 8 rises, the oil in the oil chamber 23 flows out from the orifice 29 into the oil chamber 28, and a damping force is generated, and at the time of maximum extension, the spring 24 abuts the piston 22 to activate the cushion. During compression, the hollow rod 8 descends, and the oil in the oil chamber 28 flows out from the orifice 29 into the oil chamber 23. Oil corresponding to the volume of penetration of the inner tube 2 and the hollow rod 8 is introduced into the reservoir through the port 30 and is filled with oil up to the oil surface 26a. As the oil descends, it penetrates into the oil hole rod 9 into the oil.

The oil lock chamber 6 of the oil lock case 5 is always in oil, and the oil hole rod 9 is located in the oil lock chamber 6 from the vicinity of the time of maximum compression.
The oil is discharged upward from the outer periphery of the cylinder, and an oil lock pressure is generated to activate the cushion.

Further, since the oil is always supplied to the gap 3 through the ports 4 and 7, the outer tube 1 and the inner tube 2 can be smoothly slid.

[Effect of device]

 The present invention has the following effects.

The oil lock case is always in oil, and the oil hole rod penetrates into the oil at the time of maximum compression.Therefore, when the oil hole rod is fitted into the oil lock chamber of the Oime lock case, the oil lock pressure is surely generated. , You can use the cushion.

The port provided on the upper part of the oil lock case communicates with the oil chamber in the outer tube above the oil lock chamber, so oil does not leak after the oil hole rod is fitted into the oil lock chamber, making sure Can generate oil lock pressure. Moreover, this oil lock pressure does not flow out into the gap through the port, and therefore does not act on the seal or the like that defines the gap, so that it is possible to prevent the seal from coming off.

Oil is always guided through the port to the gap,
It can be used as lubricating oil, and the inner tube and outer tube can slide smoothly.

[Brief description of drawings]

The accompanying drawings are partial front elevational views of an inverted front fork according to an embodiment of the present invention. 1 ... Outer tube, 2 ... Inner tube, 3
...... Gap 5 ...... oil lock case, 6 ...... oil lock chamber, 7 ...... port, 8 ...... hollow rod, 9 ...... oil hole rod, 19 ...... piston part, 21 ...... suspension spring, 26a ...
…Oil surface.

Claims (1)

[Scope of utility model registration request] 1. A wheel-side inner tube is slidably inserted into a vehicle-body-side outer tube, and a lower piston portion of a hollow rod concentrically provided in the center of the outer tube is slidably contacted with the inner tube to form a lower portion of the inner tube. In an inverted front fork in which a suspension spring for urging the hollow rod and the outer tube in the extending direction is interposed between the hollow rod and the piston portion of the hollow rod, an oil lock case having an oil lock chamber at the upper end of the inner tube And an oil hole rod facing the oil lock chamber is provided on the outer circumference of the hollow rod, and the position of the oil hole rod is set below the oil level at the time of the most compression in the oil chamber in the outer tube. Make a gap between the tube and the inner tube, and keep this gap above the inner tube and above the oil lock case. Inverted front fork, characterized in that communicates with the oil chamber in the outer tube through a port provided in the.