JPS61287888A - Hydraulic shock absorber for suspending rear wheel of two-wheel barrow - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hydraulic shock absorber that variably controls damping force in accordance with the amount of displacement of a wheel relative to a vehicle body.

(Prior art and its problems) In general, hydraulic shock absorbers installed in motorcycles, etc., generate damping force according to the contraction speed of the damper, but when cornering or when the vehicle is loaded.

To improve the ground contact of the wheels when the weight is large,
Alternatively, when the impact received by the wheel is large, the damping force can be increased according to the displacement It of the IIL wheel (the yield of the damper) in order to effectively absorb and alleviate the impact and prevent the piston from bottoming out. desirable.

Conventionally, as this type of hydraulic shock absorber, for example, JP-A-55-
The device disclosed in Japanese Patent No. 15372 is equipped with a variable damping mechanism in a tank that stores excess hydraulic oil corresponding to the volume of piston rod penetration into the damper, and this variable damping mechanism is applied to the excess hydraulic oil flowing into the tank. It is designed to adjust the resistance to the gas flow, and is linked to a 7-Lee piston that defines a gas chamber inside the tank. Since this 7-Lee piston is displaced as surplus hydraulic oil flows in, the damping force can be automatically increased according to the amount of contraction of the damper.

However, since the position of the 7 Leviston in the tank changes depending on the temperature of the gas chamber, there is a problem that the liquid reduction force characteristics differ depending on the temperature conditions of the tank.
Furthermore, since the pulp mechanism is installed inside the tank, there is a problem in that it is difficult to adjust the damping force characteristics from the outside.

Additionally, the applicant has already proposed a system that automatically increases the damping force according to the internal pressure of the tank.
It was undeniable that the damping force characteristics were influenced by the temperature conditions of the tank (Japanese Unexamined Patent Publication No. 57-76338,
(Refer to Publication No.-118946).

The present invention aims to solve the above problems.

(Means for Solving Problem 7α) The present invention connects a damper between a vehicle body and an unsprung member that is linked to the displacement of a wheel, and drains excess hydraulic oil corresponding to the volume of penetration of the piston rod of the damper. In a hydraulic shock absorber equipped with a gamma-sealed tank for storing surplus hydraulic oil, the tank is connected to either the vehicle body or the unsprung member, and the tank has a variable range for varying the resistance applied to the flow of the surplus hydraulic fluid. A detection rod interlocked with the 1f variable damping mechanism is slidably protruded from the tank, and this detection rod is connected to either the unsprung member or the vehicle body.

(Function) In this way, by connecting the detection loft protruding from the tank to the unsprung member approximately parallel to the damper, the variable damping mechanism directly detects the displacement of J1! through the detection rod, and The damping force can be stably controlled depending only on the displacement of the wheel without being affected by the internal temperature, and the detection a
The length of the protruding part of the Rad can be adjusted from the outside!
If a mechanism is provided, the damping force characteristics can be easily changed.

(Example) Hereinafter, an example of the present invention will be described based on the accompanying drawings.

As shown in FIG. 1, a damper 34 is connected between a vehicle body 31 of a two-wheeled vehicle and a swing arm (unsprung member) 33 that supports a rear wheel 32.

A tank 35 for storing surplus hydraulic oil of the damper 34 is formed separately from the damper 34, and the damper 34 is connected to the hose 3.
communicate with each other via 7.

One end of the tank 35 is pivotally connected to the vehicle body 31 via a pin 38, while the detection rod 14 slidably protruding from the tank 35 is pivotally connected to the swing 7-m 33 via a pin 39.

As shown in FIG. 2, the tank 35 has a 7-Lee piston 2 slidably housed in a cylindrical tank body 1 with a bottom.
This defines a gas chamber A that encloses high-pressure gas and an oil reservoir chamber B that stores excess hydraulic oil from the damper 34.

An end cap 8 is attached to the open end of the tank body 1 via an O-ring 26 and a snap ring 9, and the hose 37 is connected to the end cap 8 via a connector 28.

An oil seal case 2° is screwed into the end cap 8, and is tightened and fixed via a lock nut 23. The detection rod 14 is slidably passed through the end cap 8 via an oil seal 21.

An annular F is connected between the outer peripheral surface of the detection rod 14 and the inner peripheral surface of the end cap 8 and communicates with the damper 34 via a hose 37.
Define JI darkness G.

An annular valve seat 10 is fixed to the inside of the end cap 8 via a retaining ring 13, and a check pulp 1 is attached to this valve seat 10 via a spring 12.
Place 1. This check pulp 11 opens to the hydraulic oil returning from the oil reservoir chamber B to the damper 34.

Two tapers ttI1151L extending in the axial direction are formed on the outer circumferential surface of the tip yas of the detection rod 14, and an annular gap G and an oil reservoir chamber Bt-shield are formed between the tapers ffl15a and the inner circumferential surface of the valve seat 10. A variable orifice F is configured. .

The tapered groove 15m has one end tapered, and the area of the variable orifice F that opens between the detection arad 14 and the inner peripheral surface of the valve seat 10 as the detection a-rad 14 enters the tank 35. is gradually reduced, so that the damping force applied to the excess hydraulic oil flowing into the oil reservoir chamber B can be increased.

An annular valve seat 16 is fixed to the inside of the end cap 8 via a ring plate 17, and this valve seat 1 (
) is provided with a relief pulp 18 that is seated via a relief spring 19. One end of the relief spring 19 is supported by an oil seal case 20.

An annular gap C is defined between the relief pulp 1 and the oil seal case 20, and the detection rod 14 has a through hole 15b communicating with the rod in the lateral direction, and a through hole 15b connected to the through hole 15b and penetrating in the axial direction. A hole 15c is formed. This results in
vinegar! 7-7 When the pulp 18 opens, excess hydraulic oil from the damper 34 flows from the annular gap G to the annular gap C1 through hole 15b,
15c and flows into the oil reservoir chamber F3. In other words, the relief pulp 18 applies a predetermined damping force to the excess hydraulic oil flowing into the oil reservoir chamber B bypassing the taper ttIt15a.

A bracket 6 for pivotally supporting the bin 39 is screwed onto the base end of the detection pin 14, and is tightened and fixed via a lock nut 25. By changing the screwing position of this bracket 6, the initial position of the detection rod I#14 on the valve seat 10 can be adjusted.

The protrusion of the detection rod 14 and the lock nut 25 are covered with a bellows-shaped dust cover 24.

A bracket 6 for pivotally supporting the bottle 48 is integrally formed at one end of the tank body 1. In addition, 4 in the figure is pulp for gas filling. .

This is how vI is constructed, and the operation will be explained next.

For example, if the rear wheel 2 hits a bump in the road,
As the damper 34 contracts, surplus hydraulic oil corresponding to the intrusion volume of the piston rod (not shown) is guided from the damper 34 to the tank 35 via the hose (7). The excess hydraulic oil flows into the annular gap G via the 7-connector 28, and then flows from the annular gap G through the tapered groove 15a into the oil reservoir chamber F3, and the pressure in the annular gap G increases beyond the set value. Then, the relief pulp 18 opens against the relief spring 19 and flows into the oil reservoir chamber B through the annular gap C and the through holes 15b and 15e.

On the other hand, since the detection rod 14 is attached to the swing arm 33 substantially parallel to the damper 34, the tank body 14
go inside. As a result, when the average stroke of the damper 34 is within a predetermined range, the opening area of the taper rlIt15a formed in the detection port γ door 14 is reduced by the inner peripheral surface of the valve seat 10, and the taper groove 15a (variable orifice F ) increases the resistance applied to excess hydraulic fluid passing through the pump, and blocks this flow near the maximum stroke.

As a result, FIG. 3 shows that the contraction speed of the damper 34 is V, , V
, , V, respectively, show the damping force characteristics according to the stroke amount of the damper 34 under certain conditions, but when the stroke amount of the damper 34 is within a predetermined range of S-R, the overwhelming damping force of the damper 34 is It can be increased depending on the stroke amount.

The scales on top of this, the rear wheels? (2 strokes,
By transmitting the damping force control to Of'41 orifice through the link formation of swing arm: ): (and detection loft 14 or C), the damping force is controlled stably without being affected by the temperature conditions of tank; You can hit it by

By loosening the lock nut 25 and adjusting the screwing position of the detection port γ door 14 with respect to the bracket 6, the eight points at which the damping force begins to increase in the figure can be easily changed.

In addition, by adjusting the lock nut 2: () and adjusting the screwing position of the oil seal case 20 with respect to the end cap 8, the valve opening pressure of the relief pulp 18 changes, and the increase in damping force ends at R5 in FIG. (The valve opening (top) of relief pulp 1B can be easily changed.

On the other hand, when the damper 2 (4) is operated on the extension side, the hydraulic oil in the oil reservoir 15 opens the check pulp 11 and flows into the annular gap G with almost no resistance, and flows through the hose 3'l to the damper: (
Returning to 4, taper tilt 15 acas /l/
If released from the shielding by Shibuto 1 (), oil sump chamber B
The hydraulic oil also flows into the annular gap G from the tapered groove 15&.

Next, another embodiment shown in FIG. 4 will be described.

Two tapered grooves 15a are formed on the outer circumferential surface of the detection rod 14, and through holes 15b and 15e are formed to communicate the tapered grooves 15a to the oil reservoir chamber B.

The pulp sear 10 is press-fitted into the end cap 8 and opens and closes the tapered groove 15a with its inner peripheral surface.

A check pulp 11 urged by a beam 7 spring 12 is disposed on the valve seat 10 via a retaining ring 42, and a relief pulp 18 is disposed opposite to the check pulp 11 to seat it. The relief pulp 18 is locked to the valve seat 10, while one end of a relief spring 19 that urges the relief pulp 18 is supported by a retaining ring 44 via a retainer 43.

In this case, when the check pulp 11 and the relief pulp 18 come into contact with each other, communication between the oil reservoir chamber B and the annular gap C can be cut off, so that the valve seats on which each is seated can be eliminated, making these pulp devices more compact. It is possible.

Next, another embodiment shown in FIG. 5 will be described.

The detection rod 14 is formed with a through hole 15b that penetrates in the lateral direction, and a small hole 51 that is connected to the through hole 15b and penetrates in the axial direction. In the middle of this pore 41, a seat part 52 whose diameter expands stepwise is formed, and a ball-shaped relief pulp 53 is seated on this seat 1 part 52, and a relief which urges the Koori I No. 7 pulp 53 is formed. 5. Arranging the Spring 54 One end of the relief spring 54 is supported by a ring net 54 that is screwed into the shaft hole 51.

The tapered groove 15a formed in the detection rod 14 is opened and closed by the inner peripheral surface of the valve seat 10.
A check pulp 11 seated at 0 is disposed.

In this case as well, by housing the relief pulp 53 in the detection rod 14, the pulp apparatus can be made more compact.

(Effects of the Invention) As described above, the present invention connects a tank separate from the damper to either the vehicle body side or the unsprung member, and attaches the detection rod that protrudes freely from the tank and controls the damping force to the spring. Since either the lower member or the vehicle body side is driven by the other, the damping force can be stably controlled depending only on the wheel displacement 1 without being affected by the temperature conditions of the tank, etc. The deflation force characteristics can be easily changed by adjusting the length from the outside.

[Brief explanation of drawings]

FIG. 1 is a side view showing an embodiment of the present invention, PIS 2 is a sectional view of the tank, and FIG. 3 is a graph showing damping force characteristics. FIG. 4 is a sectional view showing another embodiment. FIG. 5 is a sectional view showing still another embodiment 6 1...Tank body, 6...Bracket, 14...
Detection rod, 15a... Taper groove, 31... Middle rest, 32... Rear wheel, 33... Swing arm, 34...
...damper, 35...tank, A...gas chamber, B
...Oil sump chamber, F...Variable orifice 14...Checkpoint, 7 dos 31...Car body 32...Ira wheel 33...Swing arm 34...Tamper 35... ·tank

Claims (1)

[Claims] In a hydraulic shock absorber, a damper is connected between a single unit and an unsprung member that is linked to the displacement of a wheel, and a tank is equipped with a gas-filled tank that stores surplus hydraulic oil corresponding to the volume of penetration of the piston rod of the damper. A variable damping mechanism is connected to either the vehicle body or the unsprung member, and the tank is provided with a variable damping mechanism that varies the resistance given to the flow of the excess hydraulic oil, and a detection rod that is linked to the variable damping mechanism is attached to the tank. 1. A hydraulic shock absorber for a rear wheel suspension of a two-wheeled vehicle, characterized in that the detection rod is slidably protruded from the unsprung member and connected to the other of the vehicle body.