JPH04203540A - Damping force adjusting type hydraulic buffer - Google Patents

Abstract

PURPOSE:To carry out the selection of damping force at different speed by installing a shutter for setting the damping force to soft when a passage between two chambers is opened and far setting the damping force to hard when the passage is closed and setting the flow resistance which acts in the switching of the shutter from hard to soft, larger than the flow resistance which acts in the reverse switching. CONSTITUTION:When a shutter 47 is set on a valve seat 32 and a bypass passage 13 is cut off, a hard state is generated, while if the shutter 47 is separated from the valve seat 32 and the bypass passage 13 is in opened state, a soft stage is generated. In the switching from the hard state to the soft state, oil tends to flow into the bypass passage 13 from a space 45, passing through an orifice 36, and a large flow resistance is generated, and the selection speed is reduced. Since, in the switching from the soft state to the hard state, a passage 37 is in opened state, oil passes through the passage 37 having a large sectional area from the orifice 36, and flows into the space 45 from the bypass passage 13. Since, at this time, the passage 37 has the smaller flow resistance than that of the orifice 36, the selection speed is increased.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a damping force adjustable hydraulic shock absorber, which is used particularly in vehicles, etc., and is a hydraulic shock absorber that can adjust the damping force depending on the road surface conditions during driving. Regarding shock absorbers.

(Prior art) Hydraulic shock absorbers used in vehicles, etc. have been proposed in the past to be able to adjust damping force as appropriate to improve ride comfort and handling stability depending on road conditions, etc. ing.

This type of damping force adjustable hydraulic shock absorber has Japanese Patent Application Laid-Open No. 2-1
As disclosed in Japanese Patent No. 59436, damping force is achieved by connecting two divided chambers through a plurality of passages and controlling the flow of oil produced in the passages by the sliding of a piston in a cylinder. By providing a damping force generating mechanism (for example, an orifice, etc.) that generates a
There are some that allow you to switch between different types of damping force and adjust the damping force.

(Invention or problem to be solved) In general, it is necessary to switch from a "soft" state to a "heart" state quickly and to switch from a "hard" state to a "soft" state slowly; ”
What is needed is an adjustable damping force hydraulic shock absorber that switches between two types of damping forces at different speeds: state and "soft" state.

In other words, while the vehicle is rolling, the hydraulic shock absorber is in a "hard" state, but if the outer wheel goes over a protrusion at this time, the vehicle suddenly switches from the "hard" state to the "soft" state. It may become unstable and the pressure fluctuations in the hydraulic shock absorber may become large, causing abnormal vibrations.

On the other hand, it is preferable to switch from the "soft J state" to the "hard" state as quickly as possible since the vehicle will be switched in a stable direction.

However, the above-mentioned conventional damping force adjustable hydraulic shock absorber simply switches between two types of damping force, a "hard" state and a "soft" state, by opening and closing the passage using a solenoid valve. , the switching speed is the same, which does not meet the above need.

Therefore, the present invention has been made to satisfy the above-mentioned needs, and can easily be divided into two states: "hard" state and "soft" state.
It is an object of the present invention to provide a damping force adjustable hydraulic shock absorber that can switch to different types of damping force at different speeds.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides communication between two partitioned chambers through a plurality of passages, and an oil liquid generated in the passages by sliding of a piston in a cylinder. A damping force adjustable hydraulic shock absorber is provided with a damping force generating mechanism that generates a damping force by controlling the flow of the passage, and the damping force can be adjusted by selectively opening and closing the passage. and a shutter that lifts off and lands on this valve seat to open and close this passage, and sets the damping force to a "soft" state when it is open and to a "hard" state when it is closed. A first flow resistance that works when switching from the "soft" state to the "hard" state, and a second flow resistance that works when switching from the "soft" state to the "hard" state, and the first flow resistance is replaced by the second flow resistance. By setting the resistor to be larger than the resistance, switching from the "hard" state to the "soft" state is relatively slow, and switching from the "soft" state to the "hard" state is relatively fast.

(Function) In the present invention configured as described above, the shutter has "
A first flow resistance that works when switching from the "hard" state to the "soft" state and a second flow resistance that works when switching from the "soft" state to the "hard J state are provided, and the first flow resistance is replaced by the second flow resistance. Since it is set larger than the flow resistance, the switching from the hard J state to the "soft" state can be relatively slow, and the switching from the "soft" state to the "hard" state can be relatively fast.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. Fig. 1 is a vertical cross-sectional view of the hydraulic shock absorber, Fig. 2 is a cross-sectional view of the main parts showing its operating state, Fig. 3 is an external view of the shutter, and Fig. 4 is a gloss diagram along line A-A in Fig. 3. , FIG. 5, and FIG. 6 are schematic diagrams for explaining the operation of the damping force adjusting valve, respectively.

First, the configuration of the embodiment will be explained with reference to FIG. The hydraulic shock absorber l is a double cylinder type, with an inner cylinder (cylinder) 2
A piston 3 is slidably fitted into the inner cylinder 2, and the inside of the inner cylinder 2 is divided by the piston 3 into an upper cylinder chamber 4 shown on the upper side in the figure and a lower cylinder chamber 5 shown on the lower side. piston 3
is attached to the outer periphery of a passage member 8 consisting of a large-diameter cylinder 6 and a small-diameter cylinder 7 screwed thereto using a nut 9, and the large-diameter cylinder 6 of the passage member 8 is One end is screwed onto the other end of the piston rod 10 which projects outward.

Further, a passage 11 is formed in the piston rod 10 for communicating the inside of the passage member 8 with the cylinder upper chamber 4, and this passage 11 is provided with a damping force adjusting valve 12 which will be described in detail later.
It is opened and closed by The interior of the passage member 8 and the passage 11 of the piston rod 10 constitute a bypass passage 13 that communicates the cylinder upper chamber 4 and the cylinder lower chamber 5.

The piston 3 has a first extension passage 14 and a twelfth contraction passage 15, which communicate the cylinder upper chamber 4 and the cylinder upper chamber 5 with each other. side passage 1
A damping force generating mechanism 16 consisting of a disc valve and an orifice passage is provided in the lower cylinder chamber 5 of No. 4 to generate a damping force by controlling the flow of oil produced during the extension process of the hydraulic shock absorber 1. and the first contraction side passage 15
On the 4th side of the 7th room of the cage, there is a
A damping force generator 11117 consisting of a disc huff is provided to generate a damping force by controlling the flowing oil.

An annular member 18 that blocks the bypass passage 13 is fitted inside the passage member 8, and the annular member M#18 has a second extension that communicates the insides of the large-diameter cylinder 6 and the small-diameter cylinder 7. A side passage 19 and a second contraction side passage 20 are formed. Therefore, inside the small diameter cylinder 7 of the second extension side passage 19, there is a disc valve and an orifice passage for controlling the flow of oil produced during the extension process and generating a damping force. A damping force generating mechanism 21 is provided in the second contraction side passage 200 on the inside side of the large diameter cylinder 6 to allow oil to flow from the inside of the small diameter cylinder 7 to the inside of the large diameter cylinder 6. A check valve 22 is provided that allows the oil to flow and restricts the flow of the oil in the opposite direction. Note that the disc valve of the damping force generation mechanism 21 provided in the second extension side passage 19 of the annular member I8 is the same as the damping force generation mechanism provided in the first extension side passage 14 of the screwdriver 3. It is set to open with a smaller pressure difference than the No. 16 disc valve. Further, the damping force generating mechanism 21 and the check valve 22 are attached to the annular member 18 by a port 23 and a nut 24.

A body part 25 that can generate a damping force during the contraction process is provided on the lower side of the inner cylinder 2, and this body part 25 includes a partition member 26 that blocks communication between the inner and outer cylinders,
Disk hull controls for controlling the flow of liquid that occurs during the contraction process are provided in the outer cylinders 29 of the third expansion side passage 27 and the third contraction side passage 28 formed in the partition member 26. 1 and an orifice passage, and an i provided on the inner cylinder 2 side of the third extension passage 27.
It also allows oil to flow from the outer cylinder 29 to the inner cylinder 2.

A back pressure valve 3 that regulates the flow of oil from the inside @ 2 to the outside @ 29
1.

Next, the damping force adjustment valve 12 will be explained. A valve seat 32 is provided in the passage 11 formed in the piston rod 1o. A shutter (valve body) 47 that opens and closes the bypass passage 13 is always urged toward the valve seat 32 by a spring member 48 disposed within a space 45 defined by the shutter 47 and the support member 34. A shaft 49 is slidably fitted into the shutter 47, and a washer 50 is attached to the lower end of the shaft 49.
The shutter 47 is pulled up as the height increases. Furthermore, an orifice 36 is formed between the inner periphery of the shutter 47 and the shaft 49 to constantly communicate the space 45 and the bypass passage 13, and a passage is formed between the outer periphery of the shutter 47 and the branch member 34. 37 is formed.

This passage 37 is closed when the shirt valve 47 is closed (
(See FIGS. 1, 3, and 4), and is configured to open when the shutter valve 47 is open (see FIGS. 2, 3, and 4).

A plunger 51 made of a magnetic material and attached to the shaft 49 is inserted into one solenoid 52 and an annular permanent magnet 53 provided below the solenoid. This permanent magnet 53 has an S pole on the inner circumferential side facing the plunger 51 and an N pole on the outer circumferential side. A base 41 made of a magnetic material is disposed above the solenoid 52, and the plunger 51 is regulated to move between the support member 34 and the base 41. A sleeve 56 made of a non-magnetic material is interposed between the plunger 51, the solenoid 52, and the permanent magnet 53, and both ends of the sleeve 56 are fitted into the support member 34 and the base 41 in a fluid-tight manner. A lead wire 54 connected to the solenoid 52 is resin-molded on the upper surface of the base 41, and is passed through the piston wand 10 and connected to the switch 55 outside the hydraulic shock absorber 1.
It is connected to a battery 44 (see FIG. 5) via a battery 44 (see FIG. 5).

Next, the effect will be explained. Solenoid 5 as shown in Figure 5
2 is connected to the battery 44, the solenoid 52 generates a magnetic field in the direction shown by the broken line, which is strengthened by the magnetic field generated by the permanent magnet 53 shown by the dashed line. Against base 41
The valve element 47 is moved upward until it comes into contact with the valve element 47, and the valve element 47 is separated from the valve seat 32, thereby opening the bypass passage 13. After that, when the power supply is stopped, the plunger 51 is held in that position by the magnetic field of the permanent magnet 53, and the shutter 47
is maintained in a state where it is separated from the valve seat 32 (the state shown in FIG. 2).

Here, if the bypass passage 13 is open, during the extension process, a small damping force ("soft" During the contraction process, a small damping force ("soft" state) is generated by the damping force generating mechanism 30 provided in the third contraction side passage 28 of the partition member 26 of the body portion 25.

Next, when the solenoid 52 is connected to the battery 44 as shown in FIG. 6, the solenoid 52 generates a magnetic field in the direction shown by the broken line, which is canceled out by the magnetic field generated by the permanent magnet 53 shown by the dashed line. , the biasing force of the spring member 48 becomes greater and the plunger 51 is lowered, the shutter 47 is seated on the valve seat 32, and the bypass passage 13 is blocked. At this time, since the shutter 47 and the shaft 49 are slidable and the shaft 49 can descend even after the shutter 47 contacts the valve seat 32, the plunger 51 cannot be brought into contact with or close to the support member 34. I can do it. Therefore, the plunger 51 and the support member 34 are attracted to each other by the magnetic field of the permanent magnet 53, and the plunger 51 is firmly held in that position.

Thereafter, when the power supply is stopped, the plunger 51 is held in that position by the magnetic field of the permanent magnet 53, and the shutter 47 remains seated on the valve seat 32 (the state shown in FIG. 1).

Here, if the bypass passage 13 is blocked in this way,
During the elongation process, the first elongation side passage 14 of the piston 3
A large damping force ("hard" state) is generated by the damping force generating mechanism 16 provided in the piston 3, and during the contraction process, it is generated by the damping force generating mechanism 17 provided in the first compression side passage 15 of the piston 3. Damping force and body part 25
The damping force generating mechanism 30 provided in the third contraction side passage 28 of the partition member 26 generates a large damping force (a "hard" state) which is added to the damping force.

In this way, by using the solenoid 52, the permanent magnet 53, and the spring member 48, the respective magnetic fields cooperate to move the plunger 51 and open the bypass passage 13 according to the direction of current flow to the solenoid 52. By opening and closing, the damping force can be adjusted, and furthermore, even if the power supply is stopped, the plunger 51 is held by the permanent magnet 53, so that the valve can be kept open or closed.

Next, the opening/closing speed of the shutter 47 will be explained. -L
mentioned. When the shutter 47 is seated on the valve seat 32 (7) and the bypass passage 13 is blocked, the shutter 47 is closed and in a "hard" state. When the bypass passage 13 is open, the shutter 47 is open and in a "soft" state.

When switching from the "hard" state to the "soft" state, oil attempts to flow from the space 45 to the bypass passage 13 through the orifice 36, creating a large flow resistance and slowing down the switching speed.

On the other hand, when switching from the "soft" state to the "hard" state, the passage 37 is open, so oil passes through the passage 37, which has a larger cross-sectional area than the orifice 36, and enters the space 45 from the bypass passage 13. flows. At this time,
Since the passage 37 has a smaller flow resistance than the orifice 36,
The switching speed becomes relatively fast.

(Effects of the Invention) As explained above, according to the present invention, the first flow resistance that acts on the shutter when switching from the "hard" state to the "soft" state, and the first flow resistance that acts when switching from the "soft" state to the "hard" state. Since the first flow resistance is set larger than the second flow resistance, "Bar 1"
The switching from the ``soft'' state to the ``soft'' state is relatively slow, and the switching from the ``soft'' state to the ``hard j'' state is relatively fast.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing an embodiment of the damping force adjustable hydraulic shock absorber of the present invention, Fig. 2 is a cross-sectional view of the main part showing its operating state, Fig. 3 is an external view of the gloss, and Fig. 4 is A-A in Figure 3.
A sectional view of the shutter taken along a line, and FIGS. 5 and 6 are schematic diagrams for explaining the operation of the damping force adjusting valve, respectively. 1... Hydraulic shock absorber, 2... Inner cylinder (cylinder), 3...
... Piston, 12 ... Damping force adjustment valve, 32 ... Valve seat, 34 ... Support member, 36 ... Orifice, 37
...Aisle, 47...Shutter. Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A damping force generation system that connects two partitioned chambers through a plurality of passages, and generates a damping force by controlling the flow of oil generated in the passages due to the sliding of a piston in a cylinder. In the damping force adjustable hydraulic shock absorber, the damping force can be adjusted by selectively opening and closing the passage, and the damping force adjustable hydraulic shock absorber includes a valve seat in the passage, and a mechanism that opens and closes the passage by seating on and taking off from the valve seat. A shutter is provided that sets the damping force to a "soft" state when the shutter is opened and a damping force to the "hard" state when the shutter is closed, and the shutter is provided with a first flow that acts when switching from the "hard" state to the "soft" state. By providing a resistance and a second flow resistance that acts when switching from the "soft" state to the "hard" state, and setting the first flow resistance larger than the second flow resistance, the "hard" state can be switched from the "soft" state to the "soft" state. It is relatively slow to switch from the “soft” state to the “hard” state.
A damping force adjustable hydraulic shock absorber that is characterized by relatively quick switching between states.