JPH0231040A - Hydraulic buffer - Google Patents

Abstract

PURPOSE:To improve the cushioning property while receiving no influence of the ambient temperature by inserting a piston with a disk valve to contact and disconnect to both end surfaces so as to furnish two cylinder chambers, and converting the diameter of the linking passage between the both end surfaces responding to the load. CONSTITUTION:When the speed in the direction of the arrow is low in the extension of a piston 3, a pressure is inflicted to the oil filled in the holes 16a and 17a of disk valves 16 and 17 to bend a disk valve 15, and the oil flows to a cylinder chamber 6 through a passage 14. And when the speed is high, a disk valve 23 is bent and the oil flows to the cylinder chamber 6 through a passage 13. Moreover, when the operation stroke of the piston 3 is large, a position detecting spring 7 is geared with a pressing member 19 of a cylinder chamber 5, a projection 19a presses a disk valve 18, disk valves 15, 16, and 17 are bent altogether, and a more force to bend the disk valve 23 is required, making difficult to form the oil passage consequently. As a result, the size of the passage hole is changed gradually operating smoothly, when the time of the oil flow to the passage 13 is extended, and the operation of the disk valve 23 is converted to the operation of the oil passage. The operation manner is same when the oil flow time is contracted.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a hydraulic shock absorber used in a shock absorber or the like for suppressing or smoothly transmitting vibrations during running of an automobile or the like.

(Prior Art) Vibrations in automobiles and the like are damped using hydraulic shock absorbers depending on the magnitude of the vibrations, thereby making the ride more comfortable.

The structure of the hydraulic shock absorber is, for example, disclosed in Japanese Patent Publication No. 58-14939.
The device disclosed in the publication forms two cylinder chambers with a piston in a cylinder filled with oil, and connects the two cylinder chambers by providing a damping valve and a side passage that bypasses the damping valve in the piston part. There is.

When the piston is actuated, most of the oil in one cylinder chamber flows through the damping valve, and when the piston position is close to the end of the cylinder, the flow path of the damping valve is closed and the side passage is opened. Since it is a flow path, the damping force changes greatly depending on the viscosity of the oil.

In addition, the device disclosed in the U, S, P, -4095682 publication has a hollow piston rod with two chambers formed on the outside and inside of the piston rod, an opening hole in the center of the rod shaft, and a piston in the hollow part of the rod. A metering pin is inserted that connects and interlocks with the Since the metering pin is thin at the center and thicker at the tip and base, it has the ability to adjust the aperture depending on the position of the piston. This device allows the oil to pass between the outside and the inside of the lot through the aperture depending on the vibration of the piston, or the speed of the piston can be attenuated depending on the position of the piston by a throttle mechanism in the aperture.

(Problems to be Solved by the Invention) However, the above-described hydraulic shock absorber has the following problems.

In the former case, when the piston's operating speed is high,
When the oil flow path is switched, a sudden change in damping force occurs, resulting in poor cushioning properties in automobiles and the like. Moreover, the impact noise caused by sudden changes causes discomfort to passengers. In addition, leakage is likely to occur in the switching portion of the flow path as the temperature rises, and the damping force may decrease.

In the latter case, the damping force is adjusted by the viscous resistance of the oil at the aperture, but as the oil temperature increases, the viscous resistance decreases, so the throttling effect decreases when the device is in a high temperature state.

In consideration of the above, an object of the present invention is to provide a hydraulic shock absorber that is not affected by ambient temperature and has good cushioning properties.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides two cylinder chambers in the cylinder by slidingly fitting the piston into the cylinder, and forming two cylinder chambers on both end surfaces of the piston. An annular valve seat is formed to communicate the two cylinder chambers. providing an extension side passage and a contraction side passage with one end opening into the annular valve seat on the one side and the other end opening outside the annular valve seat on the other side;
In addition, a plurality of stacked disc valves are provided so as to be able to come into contact with and separate from both the valve seats, and the inner disc valve that contacts the valve seat among the stacked plurality of disc valves is bent inward of the valve seat. The other disc valve located on the outside is provided with a hole that is opened and closed by the valve seat of the inner disc valve, and the outside of at least one of the two stacked disc valves is provided with a hole that is opened and closed by the valve seat of the inner disc valve. The present invention is characterized in that a pressing member is provided so as to be able to come into contact with and separate from the pressing member, and an elastic member is extended in the cylinder chamber on the side where the pressing member is arranged so as to be able to come into contact with the pressing member.

(Function) In the hydraulic shock absorber configured as described above, when the piston speed is slow, the upstream disc valve at the time of extension is moved to the adjacent hole of the disc valve or the valve as the hydraulic pressure increases. When the parts are bent, they communicate to form an orifice. When the piston speed is high, the downstream disk valve opens during extension, oil moves through the extension passage, and the damping force increases. Furthermore, when the piston moves beyond a certain stroke, the pressing member engages with the elastic member extending into the cylinder chamber, and is pressed by the elastic force, so the flat surface is bent by being pressed by the upstream disc valve or the pressing member. Therefore, under the above-mentioned hydraulic pressure, the valve part does not bend any further, an orifice is hardly formed, and the damping force does not change suddenly.The same is true during contraction.

(Example) Hereinafter, five examples of the present invention will be explained based on FIGS. 1 to 6.

FIG. 1 schematically shows a hydraulic shock absorber 1 of the present invention.
A piston 3 is slidably inserted into the cylinder 2, and a piston rod 4 connected to the piston 3 protrudes from one side of the cylinder l.
It is divided into a first cylinder chamber 5 on the side of the piston rod 4 and a second cylinder chamber 6 on the opposite side, and a stretched eccentric position detection spring 7 is fitted into the first cylinder chamber 5. A compressed eccentric position detection spring 8 is fitted into the spring 8.

Figure 2 shows details of the main parts of the piston.

An annular groove 9, lO and a groove 9.1 are provided on both end surfaces of the piston 3.
An annular protrusion 11 on the outer periphery forming a 0.12-karat valve seat is formed. Further, an extension side path 13 is formed with one end opening into the groove lO and the other end opening outside the valve seat on the opposite side, and further, one end opening into the groove 9 and the other end opening outside the valve seat on the opposite side. A contraction side path 14 that opens to the outside of the valve seat is formed.

The disc valve 23 is made by stacking a plurality of flexible disc valves, and includes a first disc valve 15 having a substantially semicircular hole 15a as shown in FIG. 3, and a first disc valve 15 as shown in FIG. a second disc valve 16 having a hole 16a bored adjacent to the outer periphery of the hole 15a of the disc valve 15;
A third disk valve 17 having a hole 17a communicating with the hole 16a of the second disk valve 16 shown in FIG. 5 and a flat fourth disk valve 18 shown in FIG. 6 are stacked one after another, The first disk valve 15 side is mounted so as to abut against the annular protrusion 11.12 of the piston. The outer periphery of the hole 15a of the first disc valve 15 is sufficiently flexible under pressure, and forms a valve portion 15b shown in FIG. 3 by a dashed line.

Further, an annular pressing member 19 is inserted through the tip of the piston rod 4 so as to come into contact with the fourth disc valve 18 located on the outside. The pressing member 19 has an annular protrusion 19a formed on the side that contacts the fourth disc valve 18, and has an outer diameter that is similar to the extension side detection spring 7 (the contraction side detection spring 8).
), and the spring 20 provided on the inner peripheral side of the pressing member 19 causes the fourth disc valve 1
It is urged in the direction of retreating from 8. 21 is a stopper for the spring 20, and 22 is a disc valve 23.
It is a sotainer that holds the center, and 24 is a tightening nut.

Next, the action of this device when it is extended will be explained.

When the speed of the piston 3 is slow (when the operating stroke is small), pressure is applied to the oil filling the holes 16a and 17a of the disc valves (16, 17) provided in the first cylinder chamber 5. As the pressure increases, the disc valve 15 is pushed up, and the valve portion 15b of the hole 15a of the disc valve 15 is bent toward the groove 9 of the piston 3. In this way, an oil passage (orifice) is formed and oil flows through the contraction side path 14 to the second cylinder chamber 6.
flows to

When the speed of the piston 3 is high, the disc valve 23 that is in contact with the downstream side of the extension path I3 is bent by the hydraulic pressure and moves away from the annular protrusion 12 (opens), so oil is released from this gap. flows into the second cylinder chamber 6. In addition, since the damping force is proportional to the piston speed, the damping of the piston speed is also large in this case.Furthermore, when the operating stroke of the piston 3 is large, the elongated eccentric position detection spring 7 causes the pressure of the first cylinder chamber 5 to increase. engages member 19; When the fourth disc valve 18 is pressed by the annular protrusion 19a or the spring bias, both the second and third disc valves 15, 16, 17 are bent in a convex manner with respect to the groove 9. This is because the initial hydraulic pressure (when the piston speed is slow) requires a force to further deflect the convexly formed disc valve 23, so it is difficult to form an oil passage (orifice) due to the deflection. Oil is difficult to flow, so the time for oil' to flow into the extension path 13 is extended, and the damping force by the orifice is activated after the vibration becomes weaker than before. Furthermore, when the disc valve is shifted from operating to the orifice, the size of the hole in the oil passage gradually changes due to the deflection of the disc valve, so it operates smoothly even against vibrations.

The same thing happens when the device is deflated, so the explanation will be omitted.

Note that the hole to be drilled in the disc valve used is not limited to this example, and for example, the second disc valve 16 and the third disc valve 17 may be combined, and the first disc valve 15 has a large inner diameter. It can also be a board.

(Effects of the Invention) Since the present invention is configured as described above, the oil passage (orifice) formed by the hole in the disc valve is difficult to form when the operating stroke of the piston is large, and is arranged in the extension path. Since the opening load of the disc valve changes, the diameter of the oil passage changes in accordance with the load, making it possible to smoothly switch the damping force, thereby improving impact noise and ride comfort. Furthermore, since it is not affected by the viscous resistance of the oil passage (orifice), a stable damping force can be obtained even when the oil temperature changes.

[Brief explanation of the drawing]

FIG. 1 is a side view of a hydraulic shock absorber according to the present invention, FIG. 2 is a cross-sectional view of essential parts in an embodiment, and FIGS. 3 to 6 are plan views of each sheet member. 2...Cylinder 3...Piston 5.6...Cylinder chamber a, 8...Elastic member 9...@11...・・・
・1 annular protrusion ・・・・Extension side passage 14 ・・・・・・Compression side passage 2: 1 (15, 16, 17, 18) ・・・Disc valve 15a, 16a, 17a・...Disc valve hole 15b...Valve part 19...Press member

Claims (1)

[Claims] (1) A piston is slidably inserted into a cylinder to provide two cylinder chambers in the cylinder, annular valve seats are formed on both end surfaces of the piston, and one end communicates the two cylinder chambers. is provided with an extension side passage and a contraction side passage, each of which has an opening in the annular valve seat on the one side and the other end opens outside the annular valve seat on the other side, and a plurality of laminated disks. A valve is provided so as to be able to come into contact with and separate from both valve seats, and among the plurality of stacked disc valves, the inner disc valve that contacts the valve seat is provided with a valve seat that can be bent inward of the valve seat, and the outer disc valve is provided with a valve seat that can be bent inward of the valve seat. The other disc valve located at the inner disc valve is provided with a hole that is opened and closed by the valve seat of the inner disc valve, and a pressing member is provided on the outside of at least one of the two stacked disc valves so as to be able to come into contact with and separate from this. A hydraulic shock absorber, characterized in that an elastic member extends in a cylinder chamber on the side where the pressing member is disposed so as to be able to come into contact with the pressing member.