JPH0746625Y2 - Car height adjuster - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a vehicle height adjusting device used as a rear cushion for a motorcycle.

(Prior Art) Conventional hydraulic shock absorbers used as rear cushions for motorcycles have not only a damping force generating function but also a function of automatically adjusting the vehicle height when the cushion sinks due to loading or the like. To make it happen, for example
A hydraulic shock absorber with a vehicle height adjusting mechanism, which is provided with a vehicle height adjusting mechanism and a damping force generating mechanism as described in Japanese Patent No. 01901, is known.

(Problems to be solved by the invention) The vehicle height adjusting mechanism of the hydraulic shock absorber with the vehicle height adjusting mechanism described above is provided with a pressure accumulating chamber formed of a spring adjuster and an adjuster guide at the lower outer periphery of the cylinder, and is arranged from the upper side to the lower side in the cylinder. Insert the piston rod with half the hollow part,
The hollow part of the piston rod is inserted into the hollow part of the cylinder to connect the hollow part of the piston rod to the accumulator, and the hollow part of the piston rod operates from the upper oil chamber to the hollow part. A check valve that allows the flow of oil and a check valve that allows the flow of hydraulic oil from the hollow part of the piston rod to the accumulator chamber are installed in the hollow rod. Also becomes expensive.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides an inner cylinder inside an outer cylinder, and an inner cylinder inner circumference is provided at the tip of a rod inserted into the inner cylinder from above. A piston that slides on the surface is attached, and a jack cylinder is attached to the outer periphery of the lower end of the outer cylinder.The jack piston is slidably fitted in the jack cylinder. In a vehicle height adjusting device having one end supported and the other end connected to the rod, a bottom oil chamber forming a jack cylinder chamber communicating with an oil chamber of the jack cylinder is defined at the bottom of the outer cylinder. A bottom piece is installed inside the bottom cylinder, and a check bar that allows oil flow from the inner cylinder to the bottom oil chamber is installed in this bottom piece. Oil in the inner cylinder from the oil passage between the outer cylinder and the inner cylinder, and the return oil passage that connects the bottom valve oil chamber and the oil chamber in the inner cylinder through the throttle. Second valve unit oil passages with check valves that allow oil flow to the chamber are formed,
In addition, a free piston that closes the return oil passage is provided between the bottom piece and the piston in a range lower than a predetermined stroke position of the piston, and an oil hole that communicates an oil chamber inside and outside the inner cylinder is provided in the inner cylinder. It was formed at a position within the sliding range.

(Operation) When the piston slides under the oil hole in the inner cylinder due to the load, the return oil passage of the bottom piece is closed by the free piston, and the piston pressure acting on the oil chamber in the inner cylinder bottoms during the compression stroke. The first valve unit of the piece acts on the jack cylinder via the oil passage and the bottom oil chamber, the jack piston is pushed out to increase the reaction force of the suspension spring, and the second valve unit in the extension stroke including the vehicle height increase accompanying this. Hydraulic oil is supplemented from the oil passage to the oil chamber in the inner cylinder to increase the vehicle height quickly, and when the piston is located above the oil hole when the load is removed, the piston pressure is Since it acts on the oil reservoir through the jack cylinder, the jack cylinder does not receive piston pressure,
Also, since the free piston opens the return oil passage of the bottom piece, when the jack piston is being pushed out, the hydraulic oil in the jack cylinder receives the damping force from the return oil passage of the bottom piece and the bottom oil chamber and the inner cylinder. The vehicle height is reduced by being returned to the oil reservoir through the inner oil chamber, and the piston is constantly adjusted to the oil hole position of the inner cylinder to maintain a constant vehicle height.

(Embodiment) An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of a vehicle height adjusting device according to the present invention, and FIGS. 2 and 3 are enlarged sectional views of a main part of FIG. 1 showing different operating states of the device.

In this vehicle height adjusting device, an inner cylinder 2 is provided in an outer cylinder 1, a rod 3 is inserted into the inner cylinder 2 from above, and a lower end portion of the rod 3 has an inner peripheral surface of the inner cylinder 2. The piston 4 is slidably contacted with the inner cylinder 2 and a position detecting oil hole 5 for detecting the position of the piston 4 is formed in the inner cylinder 2 at a desired position. (Hereinafter, referred to as "in-cylinder oil chamber".) S1 and in-cylinder oil chamber S1 and an oil chamber (hereinafter referred to as "oil reservoir chamber") S2 between outer cylinder 1 and inner cylinder 2 are communicated with each other. There is.

A rod guide 7 for guiding the rod 3 is fitted on the inner peripheral surface of the upper end portion of the outer cylinder 1, and the upper end portion of the inner cylinder 2 is mounted on the outer peripheral surface of the lower end portion of the rod guide 7.
Further, an oil seal 8 which is in sliding contact with the outer peripheral surface of the rod 3 is fitted on the inner peripheral surface of the upper end portion of the outer cylinder 1. Also,
An upper bracket 10 for attaching to the vehicle body is attached to the upper end of the rod 3, and a stopper rubber 11 is attached to the outer peripheral portion of the rod 3 on the lower surface of the upper bracket 10, and the upper spring is attached to the lower end of the upper bracket 10. Sheet
12 is locked.

A lower bracket 15 for attaching to a wheel is attached to a lower end portion of the outer cylinder 1, and a cylinder body 16 is mounted on a bottom surface of the lower bracket 15 to form a jack chamber S3, and a side surface of the cylinder body 16 is provided. Has an oil hole 18 communicating between the inside and the outside thereof, and a check valve unit 20 including a first valve unit 21 and a second valve unit 22 is arranged above the cylinder 16.

In the first valve unit 21, the first bottom piece 23 is fitted on the inner peripheral surface of the lower end portion of the outer cylinder 1, and the central portion of the first bottom piece 23 returns the jack chamber S3 to the inner cylinder oil chamber S1. A return control orifice 24 for controlling the amount of oil is formed, and in the first bottom piece 23, an oil chamber in the cylinder is formed around the orifice 24.
An oil hole 25 is formed through S1 and the jack chamber S3.
A plate attached to the lower surface of the first bottom piece 23 in 25
A check ball 28 biased upward by a spring 27 provided between the check ball 28 and 36 is provided.

The second valve unit 22 has a second bottom piece 30 fitted between the inner peripheral surface of the lower end portion of the outer cylinder 1 and the first bottom piece 23 of the first valve unit 21. 1st bottom piece 23 of 1 valve unit 21
An oil hole 31 that communicates with the oil chamber S1 in the cylinder and the jack chamber S3 is formed through the oil hole 25, and an oil groove 32 that communicates with the oil hole 31 is formed on the lower surface of the second bottom piece 30. The 2 bottom piece 30 is formed with an oil hole 33 that passes through the oil hole 31 and the oil groove 32 and passes through the in-cylinder oil chamber S1 and the oil reservoir chamber S2, and in this oil hole 33, the first bottom piece 23 is formed. Check ball 35 urged upward by a spring 34 that is interposed between
Is intervening.

In addition, the second bottom piece 30 of the second valve unit 22.
The lower end of the inner cylinder 2 is fitted to the upper end of the inner cylinder 2, and the free piston 36 is arranged in the inner cylinder 2.
At the lower end of the free piston 36, the first bottom piece 23
Install a rubber sheet 37 for contacting the opening of the controller orifice 24 of the
Is a position detecting spring 38 which is interposed between the piston 4 and
It is supported by a position detecting spring 39 provided between the second bottom piece 30 and the second bottom piece 30.

A jack cylinder 41 is fitted on the outer peripheral surface of the lower end portion of the outer cylinder 1, and a jack piston 42 is slidably fitted between the inner peripheral surface of the jack cylinder 41 and the outer peripheral surface of the outer cylinder 1. A suspension spring 43 is provided between the upper end of the piston 42 and the upper spring seat 22 locked by the upper bracket 20, and the lower end of the outer cylinder 1 has a jack chamber S3 and a lower side of the jack piston 42. An oil hole 44 communicating with the jack inner chamber S4 located at is formed, and a blow orifice 45 is formed at a position corresponding to the upper inside of the jack cylinder 41 of the outer cylinder 1. In addition, high pressure O is applied to the inner peripheral surface of the jack piston 42 downward.
A ring 46 is fitted and a low pressure O-ring 47 is fitted on the upper side.

The operation of the vehicle height adjusting device configured as described above will be described below.

First, when the sinking is small due to a small load, the piston 4 in the inner cylinder 2 strokes above the position detecting oil hole 5 of the inner cylinder 2, so when the piston 4 moves downward. The hydraulic oil in the cylinder oil chamber S1 flows into the oil reservoir S2 through the oil hole 5, and when the piston 4 moves upward, the hydraulic oil in the oil reservoir S2 moves through the oil hole 5 into the cylinder. Since the first check valve 31 does not open in any case after flowing into the oil chamber S1, the working oil does not flow into the jack inner chamber S4 and the jack piston 42 does not rise.

On the other hand, when the subsidence becomes large (the vehicle height becomes low) due to an increase in the loading amount and the like, the piston in the inner cylinder 2 strokes below the position detecting oil hole 5 of the inner cylinder 2. Therefore, as shown in FIG. 3, when the piston 4 moves downward, the cylinder internal oil chamber S1
The hydraulic pressure in the cylinder oil chamber S1 increases from the oil hole 31 of the second valve unit 21 to the oil hole of the first valve unit 21.
The check ball 28 is pushed down against the urging force of the spring 27 through 25 to open the check ball 28.
Of the hydraulic fluid flows into the jack chamber S3 through the oil holes 31 and 35, and further into the jack internal chamber S4 through the oil holes 18 and 44, so that the jack piston 42 is pushed up and the suspension spring 43.
The set load of is increased and the vehicle height is increased. At this time,
The hydraulic oil is throttled and returned from the jack chamber S3 to the in-cylinder oil chamber S1 via the control orifice 24 to prevent the vehicle height from rising rapidly.

Then, when the set load of the suspension spring 43 increases and the vehicle height rises, the rod 3 rises along with the piston, the hydraulic oil in the jack chamber S3 returns to the cylinder internal oil chamber S1 through the return control orifice 24, The hydraulic oil in the jack inner chamber S4 enters the jack chamber S3 through the oil hole 44 and the orifice
Since it escapes into the in-cylinder oil chamber S1 via 24, the jack piston 42 descends. At this time, the return of the hydraulic oil from the in-cylinder oil chamber S1 from the jack chamber S3 is throttled by the orifice 24 to prevent a sudden decrease in vehicle height.

By repeating such operations, the vehicle height is maintained constant regardless of the loaded weight.

In this case, when the piston 4 moves up below the position detecting oil hole 5, the check ball of the second valve unit 22 is
Since 35 moves downward against the urging force of the spring 34 and opens, the working oil in the oil reservoir S2 is transferred to the oil hole 33, the oil groove 32 and the oil hole.
It flows into the oil chamber S1 in the cylinder through 31 and does not hinder the upward movement of the piston 4.

In addition, when the piston 4 makes a stroke with a certain amount of depression or more due to an increase in the loaded weight and the like,
As shown in the figure, the position detecting spring 38 is compressed by the piston 4, the reaction force of the position detecting spring 38 lowers the free piston 36, compresses the position detecting spring 39, and returns by the rubber sheet 37 of the free piston 36. The upper opening of the control orifice 24 is closed, and the hydraulic oil in the jack chamber S3 returns and does not get into the in-cylinder oil chamber S1 through the control orifice 24. Therefore, since the hydraulic oil continues to flow into the jack chamber S3 due to the downward movement of the piston, the jack piston 42 rapidly rises, and the vehicle height can be returned to a constant state in a short time.

Further, when the O-ring 46 on the inner peripheral surface of the jack piston 42 rises above the blow orifice 45 of the outer cylinder 1, the working oil in the jack inner chamber S4 returns to the oil reservoir chamber S2 via the blow orifice 45, The jack piston 42 is prevented from rising excessively.

(Effect of the Invention) As described above, according to the present invention, the bottom piece that defines the bottom oil chamber is attached to the bottom of the outer cylinder, and the bottom piece is provided with the check valve. Since the second valve unit oil passage and the return oil passage communicating with each other through the throttle are respectively formed, and the free piston for closing the return oil passage is provided in a certain range, the oil hole is formed in the inner cylinder. When the piston slides under the oil hole of the inner cylinder due to the load, the return oil passage of the bottom piece is closed by the free piston, and the piston pressure acting on the oil chamber in the inner cylinder is reduced by the free piston during the compression stroke. It acts on the jack cylinder via the first valve unit oil passage and the bottom oil chamber, and the jack piston is pushed out to increase the reaction force of the suspension spring. In the extension stroke including the vehicle height increase, the hydraulic oil is supplemented from the second valve unit oil passage to the oil chamber in the inner cylinder to increase the vehicle height quickly, and when the load is removed, the piston has the same oil hole. When it is located above, the jack cylinder does not receive the piston pressure because the piston pressure acts on the oil reservoir through the oil hole.Because the free piston opens the return oil passage of the bottom piece, the jack piston Is being pushed out, the hydraulic oil in the jack cylinder is returned to the oil reservoir via the bottom oil chamber and the oil chamber in the inner cylinder while receiving the damping force from the return oil passage of the bottom piece, and the vehicle height is reduced. As a result, the piston is constantly adjusted to the oil hole position of the inner cylinder and kept at a constant vehicle height.

Therefore, the vehicle height adjusting device according to the present invention has a remarkable effect that the vehicle height can be kept constant with good responsiveness by the configuration including the bottom piece having the check valve and the throttle and the free piston.

[Brief description of drawings]

FIG. 1 is a sectional view of a vehicle height adjusting device according to the present invention, and FIGS. 2 and 3 are enlarged sectional views of a main part of FIG. 1 showing different operating states of the device. In the drawings, 1 is an outer cylinder, 2 is an inner cylinder, 3 is a rod, 4 is a piston, 5 is an oil hole in the inner cylinder, 16 is a cylinder, 20 is a check valve unit, and 23
Is the first bottom piece, 24 is the return control orifice, 27 and 34 are springs, 28 and 35 are check balls, 31 is oil hole, 32 is oil groove, 33 is oil hole, 36 is free piston, 37 is rubber sheet, 38 and 39 are position detecting springs, 41 is a jack cylinder, 42 is a jack piston, 43 is a suspension spring, S1 is an oil chamber in the cylinder, S2 is an oil reservoir chamber, S3 is a jack chamber, and S4 is a jack inner chamber.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area F16F 9/58

Claims (1)

[Scope of utility model registration request] 1. An inner cylinder is provided in an outer cylinder, and a rod, which is inserted from the upper side of the inner cylinder, is provided with a piston slidably contacting an inner peripheral surface of the inner cylinder, and a lower end portion of the outer cylinder. A jack cylinder is mounted on the outer periphery, and a jack piston is slidably fitted in the jack cylinder. The jack piston supports one end of a suspension spring and connects the other end to the rod. In the vehicle height adjusting device consisting of, a bottom piece defining a bottom oil chamber forming a jack cylinder chamber communicating with the oil chamber of the jack cylinder is attached to the bottom of the outer cylinder, and in the bottom piece, A first valve unit oil passage equipped with a check valve that allows an oil flow from the inner cylinder to the bottom oil chamber, and the bottom oil chamber and A second valve provided with a return oil passage that communicates with the oil chamber in the inner cylinder via a throttle, and a check valve that allows an oil flow from the oil reservoir between the outer cylinder and the inner cylinder to the oil chamber in the inner cylinder. Each unit oil passage is formed, and a free piston that closes the return oil passage is provided between the bottom piece and the piston within a range lower than a predetermined stroke position of the piston, and the inner cylinder has oil chambers inside and outside the free piston. A vehicle height adjusting device characterized in that an oil hole communicating with each other is formed at a position within a sliding range of a piston.