JPS5983847A - Hydraulic shock absorber - Google Patents

Abstract

PURPOSE:To make the damping force of a shock absorber adjustable in a smooth manner, by continuously varying the opening area of an orifice, which interconnects both upper and lower fluid chambers of a cylinder, on an incline formed in an adjuster attendant upon its rotation. CONSTITUTION:A through hole 9 interconnecting an upper fluid chamber 4 and a lower fluid chamber 5 an orifice 20 both are formed in a stud 7 which links a piston rod 2 and a piston 3 together, and an adjuster 14 is housed rotatably inside the stud 7. At a side part of the through hole 9 in the adjuster 14, there is formed with an incline 21 in order to continuously vary an opening area of the orifice 20 following rotation in the adjuster 14. Therefore, through a chock opening part formed by those of the orifice 20 and the incline 21, the bypass circulation of hydraulic fluid flowing between both upper and lower chambers 4 and 5 is controlled, so that damping force can be varied in a continuous manner.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is arranged between a vehicle body such as an automobile and an axle portion. This invention relates to a hydraulic shock absorber whose damping force can be adjusted.

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

First, to explain this, 1 is a cylinder filled with hydraulic fluid, and 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 separates the inside of the cylinder 1 into two chambers, an upper liquid chamber 4 and a lower liquid chamber 5, and a space between the upper and lower liquid chambers 4 and 5. This is a piston equipped with a damping force generating means 6 which generates flow resistance to the flowing hydraulic fluid.

Reference numeral 7 denotes a stud which is fully connected to the piston rod 2 and the piston 3, and is formed into a cylindrical shape as a whole, and communicates the adjuster accommodating portion 8 and the adjuster-like portions 8 with the lower liquid chamber 5. An axial through hole 9 is provided. The cylindrical wall portion 7a of the stud 7 is provided with orifices 10 and 11 that open into the upper liquid chamber 4.

12 are bored, and these orifices 10, 11
.

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 is rotatably accommodated, which is rotatably driven by a motor 13 housed in the hollow interior of the piston rod 2. The adjuster 14 has an axial through hole 15 that opens toward the lower liquid chamber 5, and this through hole 15 and the orifices 10, 11 of the stud 7.

Communication hole 16 that can selectively communicate with any one of 12
or is formed.

According to this configuration, due to the vertical movement of the piston rod 2 accompanied by the piston 3, the hydraulic fluid is supplied between the upper and lower fluid chambers 4 and 5 via the damping force generating means 6 provided on the piston 3. While it is possible to obtain a predetermined damping force by direct flow,
Motor 1 based on control signals from a controller not shown
3 to rotate the adjuster 14 by a predetermined angle, and select an orifice having a desired opening diameter among the communication hole 16 provided in the adjuster 14 and the plurality of orifices 10, 11, 12 provided in the stud 7, For example, by communicating with the orifice 10, a part of the working fluid flowing between the upper and lower liquid chambers 4 and 5 is bypassed through the orifice 10, thereby reducing the attenuation. The damping force obtained by the force generating means 6 can be adjusted to achieve a desired damping force adjustment.

By the way, in such a conventional hydraulic shock absorber, as described above, in order to adjust the damping force, the opening diameters, that is, the opening areas of the studs 7 are arranged so that they are mutually spaced in the circumferential direction, as shown in FIG. A plurality of different (three in this example) orifices 10, 11, and 12i are drilled in the regulator 14, and the orifice 14 has a diameter equal to or at least the largest diameter of the orifice 10 of the oriSwiss IQ, 11°12. A configuration is adopted in which a communicating hole 16 with a larger diameter than that is bored. Therefore, according to the conventional hydraulic shock absorber having such a configuration, the orifices 10 having different opening diameters are formed in the stud 7,
11, 12 is selected by rotating the regulator 14 to adjust the desired damping force.
9, the range of options for adjusting the damping force is narrow.

Further, according to the conventional hydraulic shock absorber, for example, as shown in FIG.
From the low damping force setting position where the communication hole 16 is located,
As shown in FIG. 4, when switching to the medium damping force setting position where the communication hole 16 of the regulator 14 is located in the orifice 11 with the second largest opening diameter, the adjustment is performed as shown in FIG. The communication hole 16 of the child 14 is located on the inner surface 7b of the stud 7 between the orifice 10 with the largest opening diameter and the orifice 11 with the second largest curved diameter, so that each orifice 10
, 11, and 12 are all closed, and therefore, the flow of fluid that should flow between the upper SG chamber 4 and the lower liquid chamber 5 through the orifices 10, 11, and 12' of the stud 7 is completely blocked. There are situations where this happens. When such a situation occurs, at that moment, the damping force suddenly increases,
As a result, there is a drawback that the riding comfort and running stability of the vehicle are seriously impaired.

``Also, according to the conventional hydraulic shock absorber, when switching from the low damping force setting position (see Figure 2) to the high damping force setting position h, as shown in Figure 3, the second The damping force must be fully adjusted once through the orifice 11 with the large opening diameter, and then at the orifice 12 with the smallest opening diameter. Therefore, the desired orifice 11 is selected by repeating the opening and closing operations of the orifice. Therefore, there is a drawback that it is not possible to set a desired damping force while continuously increasing or decreasing the damping force.

Furthermore, in the conventional hydraulic shock absorber, orifices 10 and 11 having different opening diameters are installed at a predetermined distance in the circumferential direction of the stud 7 in order to make the opening surface of the orifice variable.
, 12 with precise dimensions, each orifice 10, 11.

The drilling work for the 12 holes is complicated, which increases the cost, and there are disadvantages in that the drilling accuracy and the position of each orifice are likely to vary.

The present invention has been proposed in view of such conventional drawbacks, and provides a hydraulic shock absorber that can smoothly adjust damping force and thus improve ride comfort and running stability of a vehicle. The purpose is to provide the following.

Another object of the present invention is to provide a hydraulic shock absorber that has a simple structure and can reduce costs.

Hereinafter, embodiments of the present invention will be described according to one embodiment.

Note that the same components as those in the conventional example described above are given the same reference numerals, and redundant explanation thereof will be omitted.

Fig. 5 is a sectional view showing the main parts of the hydraulic shock absorber of this discovery J, and Fig. 9 is a sectional view taken along the vn-vu line in Fig. 5. As shown in Fig. 5, the piston rod 2 and The cylindrical wall portion 7a of the cylindrical stud 7, which is fully connected to the piston 3, includes:
Unlike the conventional example, one orifice 20 that opens into the upper liquid chamber 4 is provided. Further, the adjuster 1 is rotatably accommodated in the adjuster accommodating portion 8 of the stud 7.
4, an inclined surface 21 is formed on the side of the through hole 9 to continuously change the opening area of the orifice as the adjuster 14 rotates. By driving the adjuster 14 itself seven times relative to the opening of the orifice, the inclined surface 21 continuously closes or closes the opening of the orifice 20 with the outer peripheral surface 14a of the adjuster 14. Continuously change the opening area of the soft opening part formed by opening and adding the orifice described in P3iJ,
The penetrating oil passage 6a constitutes the damping force generating means 6, 6 provided in the piston 3 in h1j.

By bypassing a portion of the working fluid flowing between the upper and lower liquid chambers 4 and 5 through the opening portion of the throttle p, the damping force generating means 6 and 6 are
It was formed in order to adjust the damping force obtained in the above to a pure force. The inclined surface 21 'ti jru l'J straightener 14 formed with such a purpose is axially upwardly moved by the spring force of the coil spring A acting on the seven flange 14b formed on the body of the aligner 14. It is housed in the adjuster accommodating portion 8 with no gap between its outer circumferential surface 14a and the inner surface of the adjuster receiving portion 8. This adjusts the orifice 2o
This is to enable reliable and accurate opening and closing on the outer circumferential surface 14a of No. 4.

Note that one end 7C of the stud 7 is attached to the piston rod 2 and is secured to the lower end of the cylindrical portion 2a by a screw member 24 screwed into a cylindrical portion driver fixed to the outer periphery of the cylindrical portion 2a of the piston rod 2. It is tightened and fixed in place. On the other hand, the damping force generating means 6, 6 have several through oil passages 5a, 6a in the piston body 3a constituting the intangible part of the piston 3, and an opening in either one of these through oil passages 6a, 5a. It is composed of pulp plates 61) and 6b whose ends can be closed.

Next, the operation of the hydraulic shock absorber according to the present invention having the above configuration will be explained.

In the state shown in FIGS. 5 and 7, the orifice 20 provided in the stud 7 is connected to the outer peripheral surface 14 of the regulator 14.
Since it is not completely blocked by &, the opening area of the ^1j orifice addition is maximum. Therefore, in this state, a part of the working fluid flowing between the upper and lower liquid chambers 4 and 5 via the damping force generating means 6 and 6 passes through the orifice 20 by bypass. Therefore, the damping force can be adjusted to the lowest value.

Next, from this state, when the motor 13 is rotated ha and the adjuster 14 is rotated via its vertical movement shaft 13 a, the PL adjuster 14 is moved into the adjuster housing 8 provided in the stud 7. As the adjuster 14 begins to rotate gradually, the orifice is gradually closed off by the outer circumferential surface 14a of the adjuster 14. Therefore, the opening area of the diaphragm opening formed by the inclined surface 21 formed on the orifice adjustment adjuster 14 gradually becomes smaller.

Therefore, as the opening area of the diaphragm opening becomes smaller, the difference between the upper and lower liquid chambers 4 and 5.

The flow of the hydraulic fluid passing through the bypass through this throttle opening is gradually restricted. Therefore, the flow rate passing through the damping force generating means 6, 6 provided in the piston 3 gradually increases, and the flow resistance force, that is, the damping force, gradually increases. FIG. 8 shows a state in which the adjuster 14 has been rotated approximately (A) degrees from the low damping force setting position shown in FIGS. 6 and 7, and the adjuster 14 has been set to the medium damping force setting position. ing.

Thereafter, when the adjuster 14 is further rotated, the opening area of the diaphragm opening portion becomes further narrower. When the m = child 7 is further rotated approximately 90 degrees from the medium damping force setting position shown in Fig. 8 by drawing stitches, the opening area of the cut-out drawing force opening portion becomes approximately 90 degrees. It will be at or close to zero. Therefore, the hydraulic fluid flows through the throttle opening portion.

is limited to almost complete or close to it. Therefore, it will be set at a high damping force position.

Note that if the adjuster 14 is further rotated or reversed in the opposite direction, the aperture area of the diaphragm aperture portion will gradually increase, contrary to the case described above. The damping force can be continuously shifted from the high damping force setting position to the low damping force setting position so as to completely reduce the damping force.

Further, since the adjuster 14 can completely stop rotating at any position based on a control signal from a controller (not shown), the size of the diaphragm opening bottom portion can be arbitrarily set. , the damping force can be adjusted steplessly without increasing it.

As described above, in this embodiment, by fully rotating the adjuster 14, the opening area of the orifice provided in the stud 7 connecting the piston rod 2 and the piston 3 can be adjusted to the area on the side of the through hole 9. It can be continuously increased or decreased by the sloped surface 21 provided, and therefore, the upper and lower trough liquid chambers 4, 5 can be continuously increased or decreased by the orifice and through the throttle opening portion formed by the sloped surface 21. It is possible to continuously control the bypass flow of the working fluid flowing between the two.

Further, according to this embodiment, it is not necessary to form a plurality of orifices having different circumferential diameters at predetermined intervals in the circumferential direction of the stud, as in the conventional case. By forming one orifice 20 and forming an inclined surface 21 on the side of the through hole 9 of the adjuster 140, the desired purpose can be achieved, so it is a hydraulic buffer that is inexpensive and suitable for mass production. All equipment can be provided.

In addition, in the embodiment shown in FIGS. 5 to 9, the adjuster 1
Although the inclined surface 21 of the adjuster 14 is formed into a flat shape cut linearly, the present invention is not limited to this example. For example, as shown in FIG. The slope 21A'i may be formed to change the rate of change in the opening area of the aperture 9 with respect to the rotation angle of the adjuster 14.

As is clear from the above description, the present invention provides a regulator for
The entire sloped surface is formed on the side of the through hole provided in the stud,
As the adjuster rotates, the area of the aperture opening formed by the orifice provided in the stud and the inclined curve is continuously changed;
By controlling the damping force obtained by the damping force generating means provided on the piston using the inclined surface, the damping force can be smoothly adjusted in all grooves. Therefore, it is possible to prevent sudden changes in damping force while rotating the adjuster to select the desired damping force, unlike in the past, thereby improving vehicle riding comfort and driving stability. It is possible to provide a hydraulic shock absorber that can be achieved.

Furthermore, according to the present invention, the orifice formed on the stud and the sloped surface formed on the adjuster can form an aperture sealing part that covers a predetermined opening area.
To provide a hydraulic shock absorber which is free from the constraint of having to accurately form all Oriswiss studs having a predetermined opening surface and tN at predetermined intervals in the circumferential direction, and is therefore suitable for cost reduction and mass production. be able to.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the main parts of an example of a conventional hydraulic shock absorber, Figure 2 is a cross-sectional view taken along the line FIG. 4 is a sectional view showing the state in which the adjuster is rotated to the position just before reaching the damping force setting position; FIG. 6 is a partially omitted perspective view showing an example of a regulator, FIG. 7 is a sectional view taken along the vn-vn line in FIG. 5, and FIG. Similarly, FIG. 9 is a cross-sectional view showing the adjuster rotated to the adjusted consonant damping force setting position, FIG. 9 is a cross-sectional view showing the adjuster rotated to the high damping force setting position, and FIG. It is a partially omitted perspective view showing a modified example. 1... Cylinder, 2... Piston Rondo, 3...
Piston, 4... Upper liquid chamber, 5... Lower liquid chamber, 6.
... Damping force generating means, 7 ... Stud, 8 ... Adjuster housing part, 9 ... Through hole, 10, 11, 12, 20.
... Orifice, 13 ... Motor, 14 ... Adjuster, 21, 21A ... Inclined surface. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) A cylinder filled with hydraulic fluid, a piston rod that extends sealingly through one end of the cylinder, and a piston rod that is slidably inserted into the cylinder to allow two upper and lower hydraulic fluids to flow inside the cylinder. The upper part is separated into a chamber,
a piston equipped with a damping force generating means that allows limited flow of working fluid between the respective lower liquid chambers; a stud that connects the piston and the piston rond to each other and has an adjuster housing section therein; an adjuster rotatably housed in an adjuster accommodating portion of the stud;
In the hydraulic shock absorber, the hydraulic shock absorber is formed with an axial through hole that communicates between the regulator housing section and the lower liquid chamber, and an oriswiss that communicates between the regulator housing section and the front elevational liquid chamber. A hydraulic shock absorber characterized in that a sloped surface is formed on the through-hole side portion of the regulator to continuously change the opening area of the orifice as the regulator rotates.