JPS5844011Y2 - Shock absorber for vehicles - Google Patents

Description

[Detailed description of the invention] The present invention relates to a shock absorber using a fluid for vehicles such as automobiles, and in particular, it is possible to obtain a desired damping force by changing the viscosity of the fluid by utilizing changes in the temperature of the fluid. Regarding shock absorbers.

Among the various performances required of automobiles and other vehicles, ride comfort and handling stability are controlled by the suspension, and in particular the characteristics of its main components, springs and shock absorbers. Power can be said to control these things.

However, ride comfort and handling stability are generally contradictory to each other, and it is extremely difficult to obtain a suspension that satisfies both.

Especially when driving on a highway or in a city area, like a car.
In order to satisfy ride comfort and handling stability on all of these different driving roads, such as ordinary paved roads and gravel roads, it is necessary to use springs and springs that have characteristics suitable for each driving road. It is necessary to adopt a suspension equipped with a shock absorber, and it is impossible to satisfy this requirement with a spring or shock absorber having a fixed spring constant or damping force.

If we can obtain a spring or shock absorber whose spring constant or damping force can be changed according to driving conditions, the above-mentioned requirements can be satisfied, and the spring and shock absorber can be linked to each other. Since the suspension moves, if one of the characteristics can be changed, the performance of the suspension can be changed, thereby meeting the above-mentioned demands.

In other words, when it comes to shock absorbers, damping force is reduced to improve easterly comfort in urban areas and low-speed driving where it is easy to ensure steering stability, and on highways where it is easy to ensure ride comfort. At high speeds, it would be ideal to have a vehicle with a large damping force to improve steering stability.

There have been shock absorbers that can change the damping force in the past, but this conventional example mechanically adjusts a valve that controls the degree of freedom of movement of the fluid in the cylinder, and changes the degree of freedom of movement of the fluid to achieve damping. It changes the force, and this adjustment work could not be done without removing the shock absorber from the car body, or even crawling under the car body.

Therefore, the adjustment work is extremely complicated, requiring special tools, and has the drawback that the damping force of the shock absorber cannot be quickly changed in response to changes in driving conditions due to differences in driving routes, etc. Ta.

The purpose of the present invention is to provide a shock absorber for vehicles that eliminates this drawback, and its features include a cylinder filled with an appropriate fluid, and a shock absorber that is positioned within the cylinder and is moved relative to the cylinder by vibrations of the vehicle. At least a pair of orifices extending in the thickness direction, which are provided at the tip of a piston rod that moves cyclically, and a valve provided corresponding to each orifice to control opening and closing of the pair of orifices in accordance with the movement of the piston rod. a heating member for heating the fluid sealed in the cylinder; a fluid temperature detection member for detecting the temperature of the fluid sealed in the cylinder; and a fluid temperature control device for receiving a temperature detection signal and controlling the operation of the heating member to set the temperature of the fluid to a desired value based on this signal.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Reference numeral 1 denotes a cylinder, and this cylinder 1 is formed into a double-barrel type consisting of an inner cylinder 2 and an outer cylinder 3, and a cylinder head 4 is fitted to the upper end of the cylinder in order to close the cylinder and prevent fluid leakage, which will be described later. It is fixed.

The cylinder 1 is filled with a fluid 5 such as oil, which has a gap in the upper part of the outer cylinder 3 and has a large viscosity change due to temperature changes.

A disk-shaped closing member 6 is fitted and fixed to the lower end of the inner cylinder 2, and the closing member 6 has three orifices 7.8a and 8b extending in the thickness direction thereof.

The orifice 1 is always open, and the orifices 8a and 8b have valves 9 at opposite openings.
By arranging a and 9b so that they can be opened and closed,
The flow of the fluid 5 between the two cylinders 2 and 3 is controlled according to the fluid pressure within the inner cylinder 2.

A piston rod 10 is tightly fitted into the cylinder head 4 so as to be able to freely slide through the cylinder head 4, and a piston 11 is attached to the tip of the piston rod so as to be in sliding contact with the inner circumferential surface of the inner cylinder 2. .

This piston 11 is provided with three orifices 12.13a and 13b extending in the thickness direction thereof.

The orifice 12 is always open, and the orifices 13a and 13b, which are a pair of orifices, are provided with valves 14a and 14b at opposite openings, respectively, so that they can be opened and closed. The piston 11 controls the flow of the fluid 5 between an upper chamber 15 and a lower chamber 16 defined within the inner cylinder 2 in accordance with the fluid pressure.

Reference numeral 17 denotes a cylinder cover fixed to the upper end of the piston rod 10, and the inner circumferential surface of the hanging portion thereof slides into contact with an O-ring 18 fitted and fixed to the upper end of the outer cylinder 3.

Reference numeral 19 denotes a ring integrally formed at the upper end of the piston rod 10, and is attached to a vehicle body (not shown).

Reference numeral 20 is a ring fixed to the lower surface of the outer cylinder 3, and is attached to an appropriate member (not shown) of the suspension, such as a suspension linkage.

21 is an electric heater which is a heating member fixed to the inner bottom surface of the outer cylinder 3; 22 is a resistance thermometer which is a fluid temperature detecting member fixed to the inner peripheral surface of the lower end of the outer cylinder 3; 23 is the electric heater 21; A battery 24 serving as a power source is a main switch that is controlled to be turned on and off in conjunction with a starting switch (not shown) of the vehicle.

Reference numeral 25 denotes a fluid temperature control device comprising an operating section 26 such as a dial or a slide knob, and a control section 21 comprising a known electronic circuit whose operation is controlled by operating the operating section 26.

This fluid temperature control device 25 controls the fluid temperature by appropriately operating its operating section 26 and setting a fluid temperature corresponding to a viscosity that should produce a damping force suitable for the running conditions of the enclosed fluid 50 as a reference value. When the temperature value detected by the resistance thermometer 22 is lower than the reference value, the electric heater 21 is activated to increase the fluid temperature, and on the contrary, the detected temperature value is lower than the reference value. If the fluid temperature is higher than that, the electric heater 21 is stopped and the fluid temperature is controlled to be lowered.

These members and devices are connected as shown in the figure to form a control circuit, and include the electric heater 21 and the resistance thermometer 22.
The lead wire is drawn out from the lower end of the outer cylinder 3, and this drawn-out portion is sealed by a suitable sealing member 28 to prevent the fluid 5 from leaking.

The fluid temperature control device 25 is arranged so that its operating section 26 can be operated from the driver's seat of the vehicle, and the fluid temperature control device 25 is equipped with a device that facilitates the aforementioned reference value setting operation. In order to do this, the operation unit 26 is provided with a scale that numerically displays reference values corresponding to the fluid temperature in multiple stages, and a text display that roughly corresponds to the reference values with the driving conditions.

Next, the operation of this embodiment will be explained.

First, the general operation of the shock absorber in this embodiment will be explained.

When the piston rod 10 moves in the extending direction relative to the cylinder 1, that is, in the upward direction in the figure (as shown), the piston 11 accompanying the piston rod 10
If the moving speed of the piston 1 is slow and the fluid pressure in the upper chamber 15 does not reach a predetermined pressure, the fluid 5 flows only from the orifice 12 from the upper chamber 15 to the lower chamber 16.
When the moving speed of the fluid 5 increases and the fluid pressure reaches a predetermined pressure, the valve 14a is opened and the fluid 5 flows from the upper chamber 15 to the lower chamber 16 also through the orifice 13a.

The resistance force generated when the piston moves becomes a damping force.

An amount of fluid 5 equal to the volume extracted from the inner cylinder 2 by the piston rod 10 pushes open the valve 9b from within the outer cylinder 3 and flows into the inner cylinder 2 without resistance.

In addition, inside the outer cylinder 3, the air at the upper part of the outer cylinder 3 expands so as to replenish the outflow amount of the fluid 5, and the piston rod 10 contracts in the direction relative to the cylinder 1, i.e. When moving in the vertical direction in the figure, the piston 11 also moves in the same direction, so the lower chamber 16 is pressurized and the upper chamber 15 becomes under negative pressure.

Therefore, the fluid 5 in the lower chamber 16 pushes open the valve 14b into the upper chamber 15 and flows into the upper chamber 15 without resistance.
The fluid pressures in the lower chamber 16 and the lower chamber 16 are approximately the same.

On the other hand, the fluid 5 corresponding to the volume that has entered the inner cylinder 2 of the piston rod 10 passes through the orifice 7 into the lower chamber 16.
The air flows out into the outer cylinder 3, and the air above the outer cylinder 3 is compressed.

When the piston speed increases and the fluid pressure in the lower chamber 16 reaches a predetermined pressure, the valve 9a is opened and the fluid 5 flows out from the lower chamber 16 to the outer cylinder 3 through the orifice 8a as well.

The resistance force when the piston moves becomes a damping force.

Next, the operation of changing the damping force in this embodiment will be explained.

When you turn on the vehicle's starting switch, main switch 2
4 is turned on and the control circuit is closed.

When you want to change the damping force according to changes in driving conditions,
The operation unit 26 may be appropriately operated to match the reference value of the fluid temperature control device 250 with the fluid temperature of the enclosed fluid 5 that produces a viscosity corresponding to a desired damping force determined in advance through experiments or the like. .

As mentioned above, the damping force is determined by the moving speed of the piston 11, and this moving speed changes depending on the viscosity of the fluid.Furthermore, since the viscosity changes depending on the fluid temperature and has a corresponding relationship, this A desired damping force can be obtained by setting the fluid temperature to a desired value.

Therefore, by the above-described operation, the temperature of the fluid 5 is controlled to correspond to the set reference value, and a desired damping force can be obtained by controlling the temperature of the fluid 5.

In this way, according to the present invention, the desired damping force can be obtained by operating the fluid temperature control device from the driver's seat of the vehicle without applying any mechanical operations to the shock absorber. It is possible to easily change the damping force of the shock absorber during vehicle operation to obtain the optimal ride comfort and handling stability, and to compensate for performance deterioration due to long-term use of the shock absorber by adjusting the damping force. This has the effect of extending the service life.

Note that the present invention is not limited to the above-mentioned embodiments; for example, the cylinder can be of a double-barrel type filled with one type of fluid such as oil, or of a single-barrel type filled with oil and gas. Also, it goes without saying that the heating member and fluid temperature detection member are not limited to the above-mentioned electric heater and resistance thermometer. Of course, it is not limited to.

Furthermore, the fluid temperature control device may be linked to the vehicle speed detection device to automatically control the damping force in accordance with the vehicle speed.

[Brief explanation of the drawing]

The figure shows a preferred embodiment of the present invention, and is a schematic diagram showing the inside of a shock absorber and a control circuit. 1...Cylinder, 2...Inner cylinder, 3.
...Outer cylinder, 5...Fluid, 6...
Closing member, γ... Orifice, 8 a t 8
b... Orifice, 9a, 9b... Curved valve, 10... Piston rondo, 11... Curved histone, 12... Orifice, 13a, 13b...
Curved orifice, 14 a t 14 b... Valve, 21... Electric heater, 22...
Arc resistance thermometer, 25... Curved fluid temperature control device, 26...
...Operation unit, 27...Control unit.

Claims (1)

[Scope of utility model registration request] A cylinder filled with an appropriate fluid, and a piston located at the tip of a piston rond that moves relative to the cylinder due to vibrations of the vehicle.
A piston having at least a pair of orifices extending in the thickness direction, a valve provided corresponding to each orifice to control opening and closing of the pair of orifices in accordance with the movement of a piston rond, and a fluid sealed in the cylinder. a heating member for heating the fluid sealed in the cylinder; a fluid temperature detection member for detecting the temperature of the fluid sealed in the cylinder; and a temperature detection signal from the fluid temperature detection member; and a fluid temperature control device for controlling the operation of the heating member so as to set the irritability of the heating member to a desired value.