JPS6342140B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic shock absorber with adjustable damping force, which is disposed between a vehicle body such as an automobile and an axle.

BACKGROUND ART Hydraulic shock absorbers whose damping force can be adjusted according to driving conditions and the like have been known in the past in order to improve the ride comfort or driving stability of automobiles. 1st
The figure shows the configuration of such a conventional hydraulic shock absorber.

First, to explain this, numeral 1 is a cylinder filled with hydraulic fluid, and numeral 2 is a piston rod that protrudes through one end of the cylinder 1 in a sealing manner. 3 is slidably inserted into the cylinder 1, and the inside of the cylinder 1 is connected to an upper liquid chamber 4 and a lower liquid chamber 5.
The piston is separated into two chambers, and is equipped with a damping force generating means 6 that creates a flow resistance to the working fluid that is displacing and flowing between the upper and lower fluid chambers 4 and 5.

7 is formed into a cylindrical shape as a whole, and inside it,
It includes an adjuster housing part 8 and an axial hole 9 that communicates the inside of the adjuster housing part 8 with the lower liquid chamber 5.
The stud 7 connects the piston rod 2 and the piston 3, and the cylindrical wall 7a of the stud 7 includes:
Orifice 10,1 opening into the upper liquid chamber 4
1 and 12 are drilled, and these orifices 1
0, 11, and 12 are arranged in the circumferential direction with mutually different opening diameters, as shown in FIG.

In the adjuster accommodating portion 8 of the stud 7, an adjuster 14 which is rotatably driven by a motor 13 constituting a rotational drive mechanism 17 housed inside the hollow interior of the piston rod 2 is rotatably housed. This adjuster 14 has an axial through hole 15 that opens toward the front lower liquid chamber 5, and this through hole 15.
and orifices 10, 11, 12 of said stud 7.
A communication hole 1 that can selectively communicate with any one of the
6 is formed (see Figure 2).

On the other hand, reference numeral 18 denotes a reduction gear part which together with the motor 13 constitutes the rotation drive mechanism 17, and the rotational force from the motor 13 is attenuated and transmitted to the adjuster 14 by the reduction action of the damping gear part 18. It's summery. Reference numeral 19 denotes a rotational angle position detector housed in the piston rod 2 between the rotational drive mechanism 17 and the adjuster 14. The rotational angle position of the rotating shaft 18a provided in the rotating shaft 18a is detected. Further, 20 is an angle setting device disposed outside the cylinder 1 to set the angle at which the adjuster 14 should rotate, and 21 is an angle setting signal from this angle setting device 20 and an angle setting signal from the rotation angle position detector 19. This is a signal comparator that compares the rotation angle position detection signal of the rotation angle position detection signal. Furthermore, 22 is a rotation control circuit that drives and controls the rotation drive mechanism 17 in accordance with the output signal from the signal comparator 21.

In addition, 23 is a coil spring loaded between the adjuster 14 and the stud 7, and 24 is the adjuster 14.
A sealing member 25 sealing the space between the adjuster 14 and the piston rod 2 is a lubricating plate for smooth rotation of the adjuster 14.

In such a configuration, the up and down movement of the piston rod 2 together with the piston 3 causes a displacement flow of the working fluid between the upper and lower fluid chambers 4 and 5 via the damping force generating means 6 provided on the piston 3. This makes it possible to obtain damping force. On the other hand, if the angle setting device 20 is operated according to the driving condition of the vehicle, the angle setting signal selected and set by the angle setting device 20 and the angular position detection signal detected from the rotational angular position detection sensor 19 are output as signals. The motor 13 is rotated by the rotation control circuit 22 by an amount corresponding to the signal difference compared by the comparator 21, and the regulator 14 connected to the motor 13 via the damping gear part 18 is rotated at a predetermined angle. By rotating, the communication hole 16 provided in the adjuster 14 communicates with an orifice (for example, orifice 10) having a desired opening diameter among the plurality of orifices 10, 11, 12 provided in the stud 7, Therefore, the upper part,
A part of the working fluid displacing and flowing between the lower liquid chambers 4 and 5 can be bypassed through the orifice 10, thereby adjusting the damping force obtained by the damping force generating means 6 to a desired level. damping force can be obtained.

By the way, the damping force obtained by the damping force generating means 6 is obtained by the flow resistance of a hydraulic fluid having a certain viscosity.The viscosity of this hydraulic fluid changes depending on the temperature, and when the temperature of the hydraulic fluid changes, the damping force decreases. may vary slightly. In other words, in the conventional hydraulic shock absorber, even if the damping force of the hydraulic shock absorber is set at a desired position by operating the angle setting device 20, the damping force within the cylinder 1 is As the temperature of the hydraulic fluid changes, the viscosity of the hydraulic fluid increases or decreases, resulting in a corresponding increase or decrease in damping force, thus reducing the desired damping value. There were cases where a damping force different from the force was generated. As mentioned above, this includes multiple orifices 10, 11, 1.
There are many inconveniences when attempting to select the most preferable damping force by subtly changing the damping force using 2.

Recently, a temperature sensor that can detect the temperature of the hydraulic fluid has been installed inside the cylinder 1, so that even if the temperature of the hydraulic fluid changes, the appropriate damping force is always maintained stably according to the vehicle's driving conditions. Although the resulting hydraulic shock absorber has already been proposed by the applicant, this shock absorber does not have a structure in which the rotation angle position detector 19, the rotation drive mechanism 17, etc. are housed within the piston rod 2. Since the technology of providing a temperature sensor in such a hydraulic shock absorber has not yet been developed, its development has been desired.

The present invention has been made in view of these conventional drawbacks and demands for development, and includes a temperature sensor for detecting the temperature of the hydraulic fluid in the cylinder, which is provided in the piston rod that accommodates a rotational angle position detector, etc. The purpose of this study is to propose a hydraulic shock absorber that allows damping force to be corrected due to temperature changes, and that allows the desired damping force based on the design standard to be obtained even when the temperature of the working fluid changes. It is something to do.

Hereinafter, one embodiment of the present invention will be described based on the drawings. Note that the same reference numerals are given to the same components as those of the conventional example, and redundant explanation thereof will be omitted.

FIG. 3 is a sectional view of essential parts showing an embodiment of the hydraulic shock absorber according to the present invention.

In FIG. 3, numeral 26 is a temperature sensor that detects the temperature of the hydraulic fluid in the cylinder 1 and inputs the temperature data as a temperature detection signal to the rotation control circuit 22. 2) inside the support case body 19a that constitutes the outer frame of the rotation angle detector 19. As the temperature sensor 26, a temperature sensing element configured to convert temperature into an electrical quantity and extract it as an electrical signal, such as a thermistor, thermocouple material, resistance temperature detector, etc., is used. A temperature sensor harness 27 and a rotation angle position detector harness 28 are wired between the temperature sensor 26 and the rotation control circuit 22 through the inside of the piston rod 2. The terminal portion 27a of this temperature sensor harness 27 is connected to the rotational drive mechanism 1.
7 and the temperature sensor 26 at a position close to the terminal 31 for extracting the rotation angle position detection signal obtained from the slider 30 sliding on the upper part of the conductive pattern formed on the insulating substrate 29. connected. The reason why the temperature sensor 26 and the terminal part 27a of the temperature sensor harness 27 are connected at a position near the rotation angle position detector 19 is that the terminal part 27a is connected to the temperature sensor 26 and the The rotational angle position detector harness 28 is connected to the extraction terminal 31 at the same time, thereby simplifying and speeding up the wiring work for each harness 27, 28.

According to the hydraulic shock absorber having such a configuration, the rotation control circuit 22 is driven based on the angle setting signal selected by the angle setting device 20, and the control circuit 22 drives the motor 13 and deceleration which constitute the rotation drive mechanism 17. Since the rotating shaft 18a of the gear portion 18 rotates around the bearing 32, the adjuster 1
4 is rotated by the amount set by the angle setting device 20, so that a desired damping force corresponding to the driving condition of the vehicle can be obtained.

Further, according to the hydraulic shock absorber according to this embodiment, the temperature of the hydraulic fluid in the cylinder 1 is measured indirectly by the temperature sensor 26 provided inside the support case body 19a of the rotation angle position detector 19. The temperature data detected by the temperature sensor 26 is sent to the rotation control circuit 22 as a temperature detection signal.
Therefore, the adjuster 14 can be rotated to a desired position by the rotation control circuit 22 and the rotation drive mechanism 17 in response to this temperature detection signal.

In this case, if the temperature of the hydraulic fluid is high, the viscosity of the hydraulic fluid will be low, so the communication hole (not shown) provided in the regulator 14 is connected to each orifice (not shown) provided in the stud. , rotate it toward the smaller diameter orifice. On the other hand, if the temperature of the hydraulic fluid is low, the viscosity of the hydraulic fluid will be high.
The communication hole of the adjuster 14 is rotated in the direction of the larger diameter orifice among the orifices of the stud.

In this way, the regulator 14 can be rotated by a predetermined amount in response to changes in the temperature of the hydraulic fluid, and the communicating hole provided therein can be brought into communication with the orifice of a desired diameter. By correcting changes in damping force, a desired damping force can be stably obtained.

Furthermore, according to the hydraulic shock absorber according to this embodiment,
Since the temperature sensor 26 is provided within the piston rod 2, the temperature of the hydraulic fluid within the cylinder 1 can be detected accurately, albeit indirectly.

Furthermore, according to the hydraulic shock absorber according to the present embodiment, the support case body 1 of the rotation angle position detector 19
Since the temperature sensor 26 is provided in the temperature sensor 9a, the connection of the terminal part 27a of the temperature sensor harness 27 to the temperature sensor 26 is made by connecting the rotation angle position detection harness 2.
Since this can be done simultaneously with the connection to the extraction terminal 31 of No. 8, the wiring work can be simplified and speeded up.

As is clear from the above description, the present invention provides a temperature sensor in the piston rod that detects the temperature of the hydraulic fluid and inputs the detection signal to the rotation control circuit that controls the rotation drive mechanism. The desired damping force can be stably ensured regardless of temperature changes, and the damping force can be obtained in accordance with the driving conditions of the vehicle.

Furthermore, the present invention includes a temperature sensor for detecting the temperature of the working fluid in the cylinder in the piston rod that houses and arranges the rotational angle position detector, the rotational drive mechanism, etc.
Since it is provided together with the rotation angle position detector, etc., the harness for the temperature sensor and the harness for the rotation angle position detector can be connected and wired at the same time.
Therefore, connection and wiring work for each harness can be easily and quickly performed.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional hydraulic shock absorber, a part of which includes an electric circuit, Fig. 2 is a cross-sectional view taken along the line - - in Fig. 1, and Fig. 3 is a main part of the hydraulic shock absorber according to the present invention. FIG. 2 is a cross-sectional view showing a portion of the device, including a part of an electric circuit. 1...Cylinder, 2...Piston rod, 3...
...Piston, 4...Upper liquid chamber, 5...Lower liquid chamber,
6... Damping force generating means, 7... Stud, 8...
Adjuster housing portion, 9... shaft hole, 10, 11, 12...
... Orifice, 13 ... Motor, 14 ... Adjuster, 15 ... Through hole, 16 ... Communication hole, 17 ... Rotation drive mechanism, 19 ... Rotation angle position detector, 19
a...Support case body, 20...Angle setting device, 2
1...Signal comparator, 22...Rotation control circuit, 26
...Temperature sensor.

Claims (1)

[Scope of Claims] 1. A cylinder filled with hydraulic fluid, a removable piston rod that extends through one end of the cylinder in a liquid-tight manner, and a piston rod that is slidably inserted into the cylinder and that is inserted into the cylinder. a piston which is separated into two upper and lower liquid chambers, and is equipped with a damping force generating means that allows limited flow of hydraulic fluid displacing between these two liquid chambers; A cylindrical stud that connects the piston rod and has a shaft hole whose one end opens into the lower liquid chamber and a plurality of orifices that can communicate the shaft hole and the upper liquid chamber, and a cylindrical interior of the stud. an adjuster rotatably housed in the piston rod and having a communication hole capable of communicating with any one of the plurality of orifices; a rotary drive mechanism housed in the piston rod and rotatably driving the adjuster;
a rotational angular position detector that is housed between the rotational drive mechanism and the adjuster and detects the rotational angular position of a rotational shaft provided in the rotational drive mechanism; an angle setting device for setting the angle at which the rotation angle should be rotated; a signal comparator for comparing the angle setting signal from the angle setting device with a rotation angle position detection signal from the rotation angle position detector; and the signal comparator. and a rotation control circuit that controls the rotation drive mechanism according to an output signal from the cylinder, the temperature of the hydraulic fluid in the cylinder is detected and the detected signal is input to the rotation control circuit. A hydraulic shock absorber characterized in that a temperature sensor is provided within the piston rod. 2. The hydraulic shock absorber according to claim 1, wherein the temperature sensor is provided within a support case main body that constitutes an outer frame of the rotational position detector.