JP3060078B2 - Damping force adjustable hydraulic shock absorber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping force adjusting type hydraulic shock absorber used for a suspension system of a vehicle such as an automobile.

[0002]

2. Description of the Related Art Hydraulic shock absorbers used in suspension systems for vehicles such as automobiles are provided with a damping force that can be appropriately adjusted according to road surface conditions, running conditions, etc., in order to improve ride comfort and steering stability. There is a damping force adjustable hydraulic shock absorber.

As this type of hydraulic shock absorber, for example, as disclosed in Japanese Utility Model Publication No. Sho 59-22359 and Japanese Utility Model Publication No. Sho 60-37477, a plurality of passages communicate between two partitioned chambers. And a damping force generating mechanism (for example, an orifice, a disc valve) for generating a damping force by controlling the flow of an oil liquid generated in the passage by sliding of a piston in a cylinder, and providing one of the passages with an electromagnetic valve In some cases, the damping force can be adjusted by opening and closing selectively. An electromagnetic valve for opening and closing the passage is configured to open the passage by energizing a valve body that is urged by a coil spring or the like to block the passage, by energizing the solenoid.

By the way, when controlling the damping force characteristics of the hydraulic shock absorber according to the running condition of the vehicle, the road surface condition, etc., generally, when the vehicle is running normally, the softness of the damping force is small so that the riding comfort is improved, When braking, turning, traveling at high speed, and the like, the steering characteristics are improved as a hardware characteristic having a large damping force. Therefore, in a general use condition of a vehicle, the soft characteristic is set more than the hard characteristic, and the total setting time is longer.

However, in the conventional damping force-adjusting hydraulic shock absorber, when the solenoid is not energized, the valve body closes the passage by the coil spring and has a hard characteristic. There is a problem that power consumption increases if the setting time is long.

On the other hand, as compared with the above-mentioned conventional example, the solenoid valve for opening and closing the passage is configured such that its valve body is urged in the valve opening direction by a spring, so that a soft characteristic is obtained without energizing the solenoid. In some cases, hardware characteristics are provided while power is supplied. According to this configuration, the power supply time can be reduced and the power consumption can be reduced in a general vehicle use situation where the setting time of the soft characteristic is long.

[0007]

In the above-described damping force-adjustable hydraulic shock absorber, if the solenoid cannot be energized due to disconnection or the like, the hydraulic shock absorber is required to ensure good steering stability. It is desirable that the damping force characteristic is fixed on the hard characteristic side.

However, in the above-mentioned conventional type in which the solenoid has a soft characteristic in a state where power is not supplied to the solenoid, there is a problem that the damping force characteristic is fixed to the soft characteristic side when the current cannot be supplied to the solenoid.

The present invention has been made in view of the above points, and the damping force characteristic becomes a hard characteristic in a state where power is not supplied, and the damping force adjustment type hydraulic shock absorber requires less power consumption in a general use situation. The purpose is to provide a vessel.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method of sliding a piston in a cylinder.
By controlling the flow of the oil liquid generated in the oil liquid passage communicating between the two chambers to generate a damping force, and adjusting the passage area of the bypass passage communicating between the two chambers with a damping force adjusting valve. In a damping force adjusting type hydraulic shock absorber capable of adjusting a damping force, the damping force adjustment valve includes a guide member and a shutter each having an opening that can be aligned with each other.
One of the guide member and the opening of the shutter
It is substantially triangular, and the other is moved by the movement of the shutter.
Are arranged so as to be movable across the substantially triangular opening from the hard characteristic position of the bottom side to the hard position of the top side through the middle of the soft characteristic position, further, the hard characteristic the shutter of the bottom side A spring for biasing to the position side,
Characterized in that against the biasing force of the spring and a proportional solenoid actuator for displacing the shutter.

[0011]

With this configuration, when the solenoid is not energized, the damping force adjusting valve is actuated by the biasing force of the spring.
The opening of the shutter and guide member has a substantially triangular bottom
When the solenoid is energized,
The shutter is displaced so that these openings have a substantially triangular bottom.
In matched becomes soft characteristic position, further increasing the energizing current, and the shutter is displaced in proportion to the current, this
Then, the opening area is reduced, and it is moved to a hard characteristic position on the top side of the substantially triangular shape . Therefore, the damping force characteristic is a hard characteristic when the solenoid is not energized, and becomes a soft characteristic when energized, and as the energizing current increases, the damping force increases in proportion to the current and becomes a hard characteristic.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. In FIG. 1, the right side of the paper shown in FIG. 1A shows a state of hard characteristics (a state in which the solenoid is not energized), and the left side of the paper shown in FIG. 1B shows a state of soft characteristics. , (C) shows the state of the medium characteristic, and the left side of the paper shown in (d) shows the state of the hard characteristic.

As shown in FIG. 1, in a hydraulic shock absorber 1, a piston 3 is slidably fitted in a cylinder 2 filled with an oil liquid, and the piston 3 divides the inside of the cylinder 2 into a cylinder upper chamber 2a. And a lower chamber 2b. A cylindrical passage member 4 having a flange portion 4a formed on one end side is inserted into the piston 3, and a cylindrical large-diameter passage member 5 is screwed and fixed on the other end side. One end of a piston rod 6 is screwed to the flange portion 4a of the small diameter passage member 4, and the other end of the piston rod 6 extends to the outside of the cylinder 2.

The piston 3 is provided with main oil passages 7, 8 for communicating the upper cylinder chamber 2a and the lower cylinder chamber 2b. On the end surface of the piston 3 on the side of the cylinder upper chamber 2a, there is provided a damping force generation mechanism 9 including a disk valve and an orifice for controlling the flow of the oil in the main oil passage 7 to generate a damping force. On the end face of the piston 3 on the side of the cylinder lower chamber 2b, a damping force generating mechanism 10 including a disk valve and an orifice for controlling the flow of the oil in the main oil passage 8 to generate a damping force is provided.

The piston rod 6 is provided with an oil liquid passage 11 having one end communicating with the inside of the small-diameter passage member 4 and the other end opening to the side wall of the piston rod 6. The member 5 and the oil liquid passage 11 form a bypass passage 12 that connects the cylinder upper chamber 2a and the cylinder lower chamber 2b.

The large-diameter passage member 5 has an orifice for controlling the flow of the oil liquid from the cylinder upper chamber 2a to the cylinder lower chamber 2b of the bypass passage 12 to generate a damping force, and a damping force generated by a disk valve. A mechanism 13 and a check valve mechanism 14 that allows the flow of the oil liquid from the cylinder lower chamber 2b side to the cylinder upper chamber 2a are provided. The damping force generating mechanism 13
Damping force generating mechanisms 9 and 10 for the main oil passages 7 and 8 of the piston 3
The flow resistance (damping force) is set smaller than that.

In the oil passage 11 of the piston rod 6, there is provided a cylindrical guide member 15 for dividing the oil passage 11 into a cylinder upper chamber 2a and a cylinder lower chamber 2b. The chamber 2a side and the cylinder lower chamber 2b side communicate with each other through an opening 16 provided in a side wall of the guide member 15. The shape of the opening 16, as shown in FIG. 3, a large opening area of the lower (bottom side), the opening area as going to the upper (top) has a substantially triangular shape smaller. In the guide member 15, a bottomed cylindrical shutter 17 is slidably fitted. The shutter 17 is provided with an annular groove 18 as an opening along the outer periphery thereof, and an oil liquid passage 19 penetrating the side wall of the guide member 15 in the groove 18.
The shutter 17 has an oil liquid passage 20 penetrating the bottom thereof.
Is provided. Then, the guide member 15 and the shutter 17
The damping force adjusting valve is constituted by the above, and the opening 16 of the guide member 15 and the groove 18 of the shutter 17 are aligned, so that the cylinder upper chamber 2a side and the cylinder lower chamber 2b side in the liquid passage 11 communicate with each other. The upper cylinder chamber 2a and the lower cylinder chamber 2b are connected by a bypass passage 12. In addition, the groove 18 is formed in the bypass passage 12 approximately three times as the shutter 17 slides.
The hard characteristic position (a) below (bottom side) (see FIGS. 1 and 3) and the hard characteristic position above (top side) (d) (see FIGS. 2 and 3) the rectangular opening 16 therebetween. ) To communicate with each other with a passage area corresponding to the position. 1 and 2, 21 is a guide member.
15 is a support member for fixing 15.

Between the shutter 17 and the support member 21, a spring 22 for urging the shutter 17 to the lower hard characteristic position (a) side.
Is provided. One end of a rod 23 is connected to the bottom of the shutter 17, and the other end of the rod 23 is slidably inserted into the support member 21 and extends along the axis of the piston rod 6 and is built into the piston rod 6. Is connected to the plunger 25 of the proportional solenoid actuator 24. Then, by energizing the solenoid 26 of the proportional solenoid actuator 24, the solenoid 26 attracts the plunger 25 and moves upward, and moves the shutter 17 upward against the elastic force of the spring 22. .

The proportional solenoid actuator 24 generates a suction force proportional to the current supplied to the solenoid 26, and the shutter is moved to a position where the suction force and the elastic force of the spring 22 are balanced.
17 is displaced. And the solenoid
When the current supplied to the shutter 26 is a predetermined small current, the shutter 17 is displaced to the soft characteristic position (b) to maximize the passage area between the opening 16 and the groove 18. The shutter 17 is displaced upward to reduce the passage area (see FIGS. 2 and 3 (c)), and the shutter 17 is closed (FIG. 2).
And (d) of FIG. 3). In the drawing, 27 is a base plunger, and 28 is a lead wire for supplying electricity to the solenoid 26.

FIG. 4 shows the characteristics of the proportional solenoid actuator 24 and the spring 22. In FIG. 4, I ₁ , I ₂ , I
₃ indicates that the shutter 17 is located at each of the positions (b), (c),
(D) shows the relationship between the displacement of the shutter and the attraction force of the solenoid when a current necessary for the displacement is applied,
Shows the relationship between the displacement of the shutter 17 and the elastic force of the spring 22. A indicates the proportional range in which the range in which the attraction force is proportional to the energizing current, that is, the range in which the displacement of the shutter 17 is proportional to the current is limited due to the structure of the solenoid.

The operation of the embodiment constructed as described above will be described below.

When power is not supplied to the solenoid 26, the shutter
17 is at the lower hard characteristic position (a) shown in FIGS. 1 and 3 by the elastic force of the spring 22, and the bypass passage 12 is closed. Therefore, with the sliding of the piston 3 due to the expansion and contraction of the piston rod 6, the oil liquid in the cylinder 2 flows through the main oil liquid passages 8, 9 and the damping force generating mechanisms 9, 10
Generates a relatively large damping force. Therefore, the damping force characteristic becomes a hard characteristic.

When a predetermined small current is supplied to the solenoid 26, the shutter 17 is moved by the attraction force of the proportional solenoid actuator 24 to the soft characteristic position (b) shown in FIGS.
And the bypass passage 12 is opened. At this time, the opening 16
When the piston 3 slides due to the expansion and contraction of the piston rod 6, the oil in the cylinder 2 flows through the bypass passage 12 and the damping force generating mechanism 13 is activated during the extension stroke. Check valve mechanism during circulation and contraction stroke
14 and generate a relatively small damping force. Therefore,
The damping force characteristic is a soft characteristic.

When the energizing current to the solenoid 26 is further increased, the shutter 17 is further displaced upward as shown in the position (c) of FIGS. 2 and 3 by the attraction force of the proportional solenoid actuator 24, and is proportional to the energizing current. As a result, the passage area of the bypass passage 12 decreases continuously. Therefore, with the sliding of the piston 3 due to the expansion and contraction of the piston rod 6, the oil liquid in the cylinder 2 flows through the bypass passage 12 and flows through the damping force generating mechanism 13 during the extension stroke, and the check valve mechanism during the contraction stroke. 14 and generates a greater damping force than when the shutter 17 is at the position (b). Therefore, the damping force characteristic is a medium characteristic intermediate between the soft characteristic and the hard characteristic.

When the energizing current to the solenoid 26 is further increased, the shutter 17 is further moved upward by the attraction force of the proportional solenoid actuator 24, and
Is displaced to the upper hard characteristic position (d) shown in FIG. Therefore, as in the case where the solenoid 26 is not energized, the oil liquid in the cylinder 2 flows through the main oil liquid passages 8, 9 as the piston 3 slides due to the expansion and contraction of the piston rod 6, and the damping force generating mechanisms 9, 10 Generates a relatively large damping force. Therefore, the damping force characteristic becomes a hard characteristic.

As described above, when the current supplied to the solenoid 26 is zero, the hard characteristic is obtained, when the current is a predetermined small current, the soft characteristic is obtained, and when the current is more than the predetermined small current, the damping force generated in proportion to the current is continuous. And hard characteristics.

Therefore, in the case of the soft characteristic which is frequently used in a general use condition of a vehicle, a small current may be supplied, so that the power consumption is small. In the case where the current cannot be supplied due to a disconnection or the like, the characteristic becomes a hard characteristic. Operation stability can be ensured.

In this embodiment, the opening 16 has a shape as shown in FIG. 3. However, the shape is not limited to this, and any other shape can be used as long as the passage area changes similarly in accordance with the displacement of the shutter 17. Shape may be sufficient.

In this embodiment, the communication between the opening 16 and the groove 18 is cut off at the two hard characteristic positions (a) and (d) sandwiching the opening 16, and the bypass passage 12 is completely closed. The opening 16 and the groove 18 partially communicate with each other at the hard characteristic positions (a) and (d), and a small amount of oil flows from the bypass passage 12. May be set as hardware characteristics. Moreover, the damping force characteristics of the lower hard characteristic position (a) and the upper hard characteristic position (d) do not necessarily have to be the same. It may have a force characteristic.

[0030]

As described above in detail, according to the damping force adjustable hydraulic shock absorber of the present invention, the damping force adjusting valve, a guide member and a shutter having a mutually alignable openings respectively The guide member and the opening of the shutter
Is substantially triangular on one side, and the shutter moves
The other side passes through the intermediate soft characteristic position from the bottom characteristic position to the top side from the bottom characteristic position across the substantially triangular opening.
It is arranged so that it can be moved to the hard position of
A spring for biasing the shutter to the hard characteristic position side of the bottom side, in <br/> of and a proportional solenoid actuator for displacing the shutter against the biasing force of the spring, the damping force characteristics Is a hard characteristic when the solenoid is not energized, becomes a soft characteristic when energized, and when the energized current increases, the damping force increases continuously in proportion to the current, resulting in a hard characteristic. As a result, the soft characteristic can be obtained by applying a small current, so that the power consumption can be reduced in a general vehicle use condition, and the hardware characteristic can be reduced when the current cannot be supplied due to disconnection or the like. And has an excellent effect that good steering stability can be secured.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a state where hard characteristics (shutter displacement is zero) and soft characteristics are set in one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a state where a medium characteristic and a hard characteristic are set in one embodiment of the present invention.

FIG. 3 is an explanatory view showing a passage area of an opening of a shutter and a guide member of the damping force adjusting valve of the apparatus of FIGS. 1 and 2;

FIG. 4 is a diagram showing a relationship between a displacement of a shutter of a damping force adjusting valve of the apparatus of FIGS. 1 and 2, an elastic force of a spring, and an attraction force with respect to a current supplied to a proportional solenoid actuator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Damping force adjustment type hydraulic shock absorber 2 Cylinder 2a Upper cylinder chamber 2b Lower cylinder chamber 3 Piston 8, 9 Main oil liquid passage 12 Bypass passage 15 Guide member 16 Opening 17 Shutter 18 Groove (opening) 22 Spring 24 Proportional solenoid actuator

Continuation of front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16F 9/00-9/58 B60G 17/08

Claims (1)

(57) [Claims] 1. A bypass passage that controls a flow of an oil liquid generated in an oil liquid passage communicating between two chambers by sliding a piston in a cylinder to generate a damping force, and that communicates between the two chambers. A damping force-adjustable hydraulic shock absorber in which the damping force can be adjusted by adjusting the passage area of the damping force adjusting valve, wherein the damping force adjusting valve has a guide member having openings that can be aligned with each other. and and a shutter, the guide portion
One of the openings of the material and shutter has a substantially triangular shape.
The movement of the shutter causes the other to have the substantially triangular opening.
It can be moved from the hard characteristic position on the bottom side to the hard position on the top side through the middle soft characteristic position across the part
It is arranged to further comprises a spring for biasing the shutter to <br/> hard characteristic position side of the bottom side, and a proportional solenoid actuator for displacing the shutter against the biasing force of the spring damping force adjustable hydraulic shock absorber, characterized in that there.