JP4426718B2 - Damping valve structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a damping valve structure, and more particularly to an improvement of a damping valve structure in a hydraulic shock absorber.
[0002]
[Prior art and its problems]
For example, in a hydraulic shock absorber that is disposed between the vehicle body and the axle of a vehicle and absorbs road surface vibration by generating damping force during expansion / contraction operation, when the expansion / contraction operation is performed in the middle / high speed range beyond the low speed range Of course, it is set so as to generate a predetermined amount of damping force, but on the other hand, it also generates a predetermined amount of damping force when the telescopic operation is performed in the low to low speed region. It is considered preferable to be set.
[0003]
For this reason, various damping valve structures have been proposed so far that can generate a damping force of a predetermined magnitude during expansion and contraction operation from a very low speed range to a low speed range. For example, as shown in FIG. In the damping valve structure, it may be pointed out that the productivity in the hydraulic shock absorber as the final product is likely to be lowered.
[0004]
That is, the damping valve structure of this conventional example is embodied in the piston portion of the hydraulic shock absorber as shown in FIG. 5, but the piston 1 that is the valve seat member that constitutes this piston portion is provided. Is provided with a rear valve 2 that enables a damping force to be generated in a low speed range exceeding a very low speed range.
[0005]
The back valve 2 is a poppet 2a that is opened in the piston 1 so as to open and close the downstream end, which is the upper end in the drawing, in the subport 1b that is an outer port that allows communication between the upper side and the lower side. The poppet 2a has an urging spring 2b that urges the poppet 2a from behind.
[0006]
At this time, the urging spring 2b in the rear valve 2 is composed of a coil spring, and has different lengths so that each spring force is divided, and is arranged on the so-called rear side of the rear valve 2. It is assumed that it is housed in the housing 3 to be made.
[0007]
Incidentally, in this conventional proposal, the main valve that is opened in the piston 1 and closes the downstream side end that is the lower end in the figure in the main port 1a that is the inner port that allows communication between the upper side and the lower side so as to be opened and closed. 4 is formed with a choke path formed by a notch groove 4a communicating with the main port 1a.
[0008]
Therefore, when assembling the above-described back valve 2 to the piston 1, the housing 3 must be arranged so as to correspond to the arrangement state of the biasing springs 2b having different lengths. In order to avoid the problem, so-called labor is required, and as a result, the productivity of the hydraulic shock absorber as the final product is easily lowered.
[0009]
The present invention has been developed in view of the above-described circumstances, and the object of the present invention is to enable generation of a predetermined damping force as well as to reduce productivity in the hydraulic shock absorber. An object of the present invention is to provide a damping valve structure that is optimal for expecting improved versatility in the hydraulic shock absorber.
[0010]
[Means for Solving the Problems]
In order to achieve the above-described object, the configuration of the present invention basically includes a damping that generates a predetermined damping force during expansion / contraction operation in a hydraulic shock absorber in which the upper end side is connected to the vehicle body side and the lower end side is connected to the axle side. The valve seat member that separates and seats the main valve and the rear valve has a main port and a sub port that allow communication between the upper and lower sides, and the downstream end of the main port can be opened and closed. An annular leaf valve in which the closed main valve has a choke path communicating with the main port, and a rear valve that closes the downstream end of the subport so as to be openable and closable is seated on the downstream end of the subport, and the annular leaf valve In a damping valve structure having a ring seat adjacent to the back surface, a plurality of annular leaf valves in which main valves are stacked are used. Together, while by forming a choke passage to the annular leaf valve comprising a plurality which is the laminated, ring seat in the rear valve and comprising a plurality of cutout portions to permit deflection of the annular leaf valve.
[0011]
Then, in the configuration described above, more specifically, a plurality of cutout portions of the is in the Amblyseius the length of a in the circumferential direction on the outer peripheral side of the ring seat.
[0012]
Further, the valve seat member is a piston in the piston portion of the hydraulic shock absorber, or a valve disk in the base valve portion of the hydraulic shock absorber.
[0013]
Further, in the rear valve , a centering member is provided adjacent to the rear surface of the ring seat , and a ring is provided on the outer periphery of the centering member, while an annular leaf valve is provided adjacent to the centering member and the rear surface of the ring. Suppose that
[0014]
At this time, the outer diameter of the ring is the same as the outer diameter of the ring seat, and the outer diameter of the annular leaf valve adjacent to the back surface of the ring is the same as the outer diameter of the ring. It may be larger than the outer diameter.
[0015]
The annular leaf valve adjacent to the back surface of the ring may be a laminated annular leaf valve formed by laminating a plurality of sheets, and the thickness of the ring is equal to or greater than the thickness of the centering member. It is also good.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
In the following, the present invention will be described based on the illustrated embodiment. In the illustrated damping valve structure, the upper end side is connected to the vehicle body side of a vehicle (not shown) and the lower end side is also an axle (not shown). The hydraulic shock absorber connected to the side is embodied in a piston portion that generates a predetermined damping force during an expansion / contraction operation.
[0017]
At this time, the piston 1 constituting this piston portion is slidably received in a cylinder 5 whose lower end side is connected to the axle side of the vehicle, while the piston rod 6 whose upper end side is connected to the vehicle body side of the vehicle. It is assumed that the front end fitting portion 6a is fixedly held.
[0018]
The piston 1 is a valve seat member in the damping valve structure, and has a main port 1a that is an oblique port that allows communication between the upper portion and the lower portion thereof, and a subport 1b that is also an oblique port. A main valve 7 that closes the downstream side end that is the lower end in the drawing of the main port 1a so as to be openable and closable is provided adjacently, and the rear valve 8 that closes the downstream end that is the upper end of the subport 1b in the drawing so as to be openable and closable. Next door.
[0019]
At this time, in the present invention, the main valve 7 is composed of a plurality of stacked annular leaf valves 71, 72, 73, and the plurality of annular leaf valves 71, 72, 73 are stacked. The inner peripheral end is fixed and the outer peripheral end is freely distributed.
[0020]
The main valve 7 is provided with a support 75 urged from the back side by a biasing spring 74 on the outer peripheral side of the rear surface which is the lower end surface in the figure.
[0021]
Therefore, the main valve 7 is urged from the back side by the urging spring 74 through the support 75. Therefore, the spring force of the urging spring 74 is set appropriately. Thus, it is possible to embody the generation of damping force during the extension side operation from the low speed to the medium to high speed range.
[0022]
On the other hand, even in the present invention, the main valve 7 has a choke path (not shown) communicating with the main port 1a, and this choke path is used when the hydraulic shock absorber is extended and contracted in a very low speed region. A damping force is generated.
[0023]
At this time, this choke path is formed in the above-described plurality of stacked annular leaf valves 71, 72, 73 in the present invention.
[0024]
That is, among the plurality of annular leaf valves 71, 72, 73, the intermediate annular leaf valve 72 has a substantially choke path in cooperation with the upper and lower annular leaf valves 71, 73 in the adjacent drawing. A notch 72a is formed, and this notch 72a communicates with the main port 1a via a hole 71a formed in the annular leaf valve 71 adjacent to the intermediate annular leaf valve 72 from above in the drawing. If so.
[0025]
Therefore, when the hydraulic shock absorber is expanded and contracted in a very low speed region, the hydraulic oil passes through the choke path formed by the above-described notch portion 72a. Therefore, the linear characteristic, that is, the linear characteristic is attenuated. As a result, a preferable vibration absorption can be realized as compared with a case where a damping force in a very low speed region is obtained by an orifice having a square characteristic.
[0026]
The choke path is formed in a plurality of stacked annular leaf valves 71, 72, 73 constituting the main valve 7. That is, the choke path is constituted by a notch 72a formed in the annular leaf valve 72. Therefore, it is advantageous in that the choke path can be easily formed as compared with the conventional example in which the notch groove 4a is formed in the main valve 4 to form the choke path.
[0027]
On the other hand, the back valve 8 has an annular leaf valve 81 which is fixed to the downstream end of the sub-port 1b (see FIG. 1) and is seated in a manner that allows the outer peripheral end to be freely fixed, and is also fixed to the inner peripheral end and freely free from the outer peripheral end. In this manner, the annular leaf valve 81 has a ring seat 82 adjacent to the back surface which is the upper end surface in the drawing.
[0028]
As shown in FIG. 3, the ring seat 82 includes a plurality of notches 82 a, 82 b, and 82 c that are intermittently formed in the circumferential direction and allow the annular leaf valve 81 to bend. It is said.
[0029]
At this time, the respective notches 82a, 82b, 82c have different lengths in the circumferential direction. In the drawing, the length L at the notch 82a is maximized, and the length S at the notch 82c is increased. It is assumed that the length M at the notch portion 82b is set to the minimum between the so-called lengths L and S.
[0030]
Therefore, in the annular leaf valve 81 in which the annular seat 82 formed as described above is provided adjacent to the back surface, when the hydraulic pressure from the subport 1b acts on the pressure receiving surface which is the lower end surface in FIG. The part facing the notch 82a having the maximum length L bends, the part facing the notch 82b having the long length M is bent next as the oil amount increases or the hydraulic pressure increases, and finally the minimum length is obtained. The part facing the notch 82c of S is bent, so that it is in a fully open state.
[0031]
By the way, when the annular leaf valve 81 is bent all around and is in the fully open state, the outer peripheral side end is also bent in the ring seat 82.
[0032]
As a result, in the above-described rear valve 8, the rigidity in the annular leaf valve 81 and the ring seat 82, and further, the so-called depth in the notches 82a, 82b, and 82c of the ring seat 82 are variously selected. The generation of the damping force in the low speed range after the very low speed range can be realized, and at the same time, the change width can be reduced to realize the generation of the damping force having a smooth, ie, linear characteristic.
[0033]
In addition, in the case of the rear valve 8 described above, it is possible to generate a damping force in this kind of low speed range. For example, compared to the conventional example, the valve configuration is simplified, and therefore If the stacking order of the annular leaf valve 81 and the ring seat 82 is not wrong when the piston 1 is installed next to the piston 1, it is difficult to cause a wrong combination of the valves, and positioning is not required for the horizontal rotational position. This is advantageous in that the valve assembly operation can be performed quickly.
[0034]
When the rear valve 8 having the annular leaf valve 81 and the plate-shaped ring seat 82 is provided adjacent to the piston 1 and embodied in the piston portion, the biasing force comprising a poppet and a coil spring is provided. Compared to the case of a conventional example having a spring, it is advantageous in that the length in the axial direction of the piston portion in the extending direction of the piston rod 6 can be reduced.
[0035]
Incidentally, as shown in the figure, a centering member 83 is provided adjacent to the back surface of the ring seat 82 constituting the back valve 8 and a ring 84 is interposed on the outer periphery of the centering member 83, while the centering member 83 and An annular leaf valve 85 is provided adjacent to the back surface of the ring 84.
[0036]
At this time, the outer diameter of the ring 84 is the same as the outer diameter of the ring seat 82, and the outer diameter of the annular leaf valve 85 is the same as the outer diameter of the ring 84 in the drawing. Of course, it may be larger than the outer diameter of the ring 84 in view of its function.
[0037]
Although the annular leaf valve 85 is a laminated annular leaf valve formed by laminating a plurality of sheets, the annular leaf valve 85 may be composed of a single annular leaf valve, although not shown. .
[0038]
Incidentally, when the annular leaf valve 85 is formed of a laminated annular leaf valve, it is possible to embody generation of a damping force after the middle speed region that cannot be realized by the rear valve 8 having the above-described configuration.
[0039]
By the way, as shown in FIG. 4, the ring 84 is provided adjacent to the upper end surface on the outer peripheral side of the annular seat 82 which is the lower side in FIG. It sometimes rises at the same time and functions to bend the outer peripheral side end of the annular leaf valve 85.
[0040]
Therefore, although the thickness of the ring 84 is the same as the thickness of the centering member 83 interposed inside the ring 84 in the drawing, it is not shown in the figure. It may be thicker than the thickness of the member 83.
[0041]
By making the thickness of the ring 84 equal to or greater than the thickness of the centering member 83, the ring 84 applies an initial load to the annular leaf valve 85 in advance. The cracking pressure in the annular leaf valve 85 can be increased as compared with the case where no is provided.
[0042]
Therefore, in the rear valve 8 having the ring 84 and the annular leaf valve 85, by changing only the thickness of the ring 84 without changing the rigidity or the number of the annular leaf valves 85, the annular leaf is changed. It is possible to increase the cracking pressure in the valve 85, which is advantageous in that the change of the cracking pressure can be realized by a simple measure.
[0043]
In addition, when the thickness of the ring 84 is changed to be increased, the cracking pressure in the lower annular seat 82, that is, the annular leaf valve 81 urged by the annular seat 82 is increased. Therefore, it is also advantageous in that the damping force when the outer peripheral end of the annular leaf valve 81 is pressed against the valve seat member and is greatly bent over the entire circumference can be increased. Become.
[0044]
Incidentally, since the centering member 83 described above is arranged to position the ring 84 at a predetermined position, the planar shape is changed to the circular shape shown in FIG. 4 as long as it fulfills its function. Although not shown, it is needless to say that other arbitrary shapes such as a cross shape and a star shape may be set.
[0045]
As described above, the annular leaf valve 81 is gradually opened by using the plurality of notches 82a, 82b, and 82c in the ring seat 82, but the annular leaf valve 81 is not fully opened at once. In other words, as long as the state is fully opened in a stepwise manner, although not shown in the drawing, there is one notch portion in the ring seat 82, so that the annular leaf valve 81 is said to be in a fully open state in a stepwise manner. Of course it is also good.
[0046]
When there is one notch portion in the ring seat 82, although not shown, the notch portion is set to be spiral, that is, set to increase the notch depth of the notch portion as it advances in the circumferential direction. In this case, the annular leaf valve 81 can be fully opened stepwise as compared with the case where the notch depth is the same.
[0047]
Further, the above description has been made on the case where the damping valve structure according to the present invention is embodied in the piston portion of the hydraulic shock absorber. However, from the intention of the present invention, although not shown, The damping valve structure may be embodied in the base valve portion of the hydraulic shock absorber, and it goes without saying that the operation and effect in this case are the same as described above.
[0048]
【The invention's effect】
As described above, in the present invention, since the damping force in the very low speed region in the hydraulic shock absorber is obtained by the choke path, a linear characteristic, that is, a linear characteristic damping force is obtained, and the slow speed is reduced. Compared to the case where the damping force in the region is obtained by an orifice having a square characteristic, it is possible to realize preferable vibration absorption, as well as to be formed in one annular leaf valve in which choke paths are stacked. Since it consists of a notch part, compared with the case where the choke path which consists of a notch groove is formed in a main valve like the prior art example, there exists an advantage that formation of a choke path becomes easy.
[0049]
Further, in the present invention, the annular seat adjacent to the rear surface of the annular leaf valve constituting the rear valve has a plurality of notches that allow the annular leaf valve to bend in the circumferential direction. When the plurality of cutouts have different circumferential lengths, the so-called opening operation of the annular leaf valve can be gradually shifted to the fully open state by permuting the lengths of the cutouts. Therefore, by variously selecting the so-called depth of the annular leaf valve and the so-called depth of the notch, it is possible to generate a damping force in the low speed range after the very low speed range. It is possible to realize a damping force generation that is small and smooth, that is, linear.
[0050]
In addition, since the above-described rear valve has an annular leaf valve and a ring seat adjacent to the rear surface of the annular leaf valve, the conventional rear valve urges the poppet and the poppet from behind. There is an advantage that the length in the axial direction of the piston portion in the extending direction of the piston rod can be reduced as compared with the case where the biasing spring made of a coil spring is provided.
[0051]
In the above-described rear valve, the valve configuration is simpler than that of the conventional example. Therefore, when the valve is installed next to the valve seat member, even the stacking order of the annular leaf valve and the ring seat is wrong. Otherwise, it is difficult to cause a wrong combination of the valves, and there is an advantage that the valve assembling work can be quickly performed because positioning is not required for the rotational position in the horizontal direction.
[0052]
In the present invention, a centering member is provided adjacent to the back surface of the ring seat constituting the back valve, and a ring is interposed on the outer periphery of the centering member, while the centering member and the back surface of the ring are annular. If the leaf valve is installed next to the rear valve, in addition to the generation of damping force in the low speed region, the generation of damping force in the middle speed region and later can be realized, in that case, Even if the number of the centering member and the annular leaf valve adjacent to the back of the ring increases, as described above, the conventional back valve has a biasing spring comprising a poppet and a coil spring that biases the poppet from behind. The piston in the extending direction of the piston rod is of course easier to assemble than if it has There is an advantage capable of decreasing the length in the axial direction of.
[0053]
Not only that, if the thickness of the ring is equal to or greater than the thickness of the inner centering member, the cracking pressure in the annular leaf valve stacked on the back surface of the ring can be made higher. Change the cracking pressure of the annular leaf valve stacked on the back of the ring with a simple measure that changes only the thickness of the ring without changing the rigidity and number of the annular leaf valve stacked on the back of the ring. There are advantages you can do.
[0054]
When the ring thickness is changed so as to increase, it is possible to increase the cracking pressure in the lower ring seat, that is, the annular leaf valve urged to the ring seat. There is also an advantage that the damping force can be further increased when the outer peripheral end of the leaf valve is pressed against the valve seat member and greatly bent over the entire circumference.
[0055]
[0056]
[Brief description of the drawings]
FIG. 1 is a partial longitudinal sectional view showing a state in which a damping valve structure according to an embodiment of the present invention is embodied in a piston portion of a hydraulic shock absorber.
2 is a partial longitudinal sectional view showing an enlarged main part in FIG. 1; FIG.
3 is a plan view showing a ring seat and an annular leaf valve below the ring seat at the position AA in FIG. 1; FIG.
4 is a view showing a ring and a centering member inside thereof at the position of the line BB in FIG. 1, as in FIG.
FIG. 5 is a view similar to FIG. 1 showing a state in which a damping valve structure as a conventional example is embodied in a piston portion of a hydraulic shock absorber.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Piston 1a Main port 1b Sub port 5 Cylinder 6 Piston rod 6a Tip fitting part 7 Main valve 8 Rear valve 71,72,73,81,85 Annular leaf valve 71a Hole 72a, 82a, 82b, 82c Notch part 74 Energizing spring 75 Support 82 Ring seat 83 Centering member 84 Ring

Claims (2)

A damping valve structure that generates a predetermined damping force during expansion / contraction operation in a hydraulic shock absorber whose upper end side is connected to the vehicle body side and whose lower end side is connected to the axle side, and a valve seat member for separating and seating the main valve and the rear valve is A main port and a sub port that allow communication between the upper side and the lower side, and a main valve that closes the downstream end of the main port so as to be openable and closable have a choke path that communicates with the main port, while downstream of the sub port. A main valve in a damping valve structure having an annular leaf valve in which a rear valve for closing and closing the side end is seated on and off the downstream end of the subport and an annular seat adjacent to the rear surface of the annular leaf valve Is made up of a plurality of annular leaf valves stacked together. While by forming a road, ring seat and having a plurality of cutouts to permit deflection of the annular leaf valve in the rear valve, there notch of the plurality of the outer peripheral side of the ring seat of the circumferential length A damping valve structure characterized by being divided into sections . In the back valve, a centering member is provided next to the back of the ring seat and a ring is interposed on the outer periphery of the centering member, while an annular leaf valve is provided next to the centering member and the back of the ring. The damping valve structure according to claim 1.

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