JPH0525045U - Variable damping force buffer - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a damping force variable shock absorber capable of preventing deterioration of dimensional accuracy due to deformation of an adjuster, enabling downsizing of a stopper member, and increasing versatility of applicable shock absorber size. [Arrangement] An adjuster 12 rotatably provided in a through hole 3b of a stud 3 and having flat surface portions 12e, 12e formed parallel to the side surface thereof, and a flat surface portion 12e of the adjuster 12,
12e is rotated and fixed in the large-diameter hole 3h of the stud 3 on the same plane as 12e, and the flat portions 12e and 12e abut on the inner peripheral side of the central hole 19a through which the adjuster 12 is inserted. Protrusion stoppers 19c, 1 that regulate the range
And plate 19 with 9c.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a shock absorber that can be used in a vehicle suspension and that can change the damping force range.

[0002]

[Prior Art]

 As a conventional damping force type shock absorber, for example, the one described in Japanese Utility Model Laid-Open No. 63-33038 or Japanese Utility Model Laid-Open No. 63-33040 is known.

This conventional damping force variable type shock absorber includes an expansion side damping valve that generates a damping force by limiting the flow of a fluid between two chambers defined at the time of extension of the shock absorber, and a shock absorber. A compression side damping valve that generates a damping force by limiting the flow of fluid between the two chambers defined during the pressure stroke, a bypass flow path that bypasses both damping valves and communicates between the two chambers, An adjuster having a variable throttle section arranged in the bypass channel and capable of changing the channel cross-sectional area, and changing the throttle opening of the variable throttle section by rotating the regulator. The flow passage cross-sectional area of the bypass flow passage was changed by this, and thereby the damping force range on the extension side and the compression side could be changed.

Then, the positioning pin is press-fitted and fixed in the lateral hole formed in the radial direction on the adjuster side, and the positioning pin abuts on the outer peripheral stud side. The structure is such that a stopper member for restricting the rotation range of the adjuster is provided.

[0005]

[Problems to be solved by the device]

 However, in such a conventional damping force type shock absorber, since the positioning pin is used as a means for restricting the rotating range of the adjuster, the lateral hole formed in the adjuster is On the other hand, there is a problem that a step of press-fitting the positioning pin is required, and the impact force at the time of press-fitting causes the adjuster to deform such as runout or bending, which may deteriorate the dimensional accuracy. It was

Further, since the positioning pin is projected to the outer periphery of the adjuster, the outer shape of the stopper member becomes large, which causes a problem of poor versatility of the applied shock absorber size.

The present invention has been made by paying attention to the above-mentioned conventional problems, can prevent deterioration of dimensional accuracy due to deformation of the adjuster, can downsize the stopper member, and can be applied to the shock absorber size. It is an object of the present invention to provide a damping force variable type shock absorber capable of enhancing the versatility of the above.

[0008]

[Means for Solving the Problems]

 In order to achieve the above-mentioned purpose, In the damping force variable type shock absorber of the present invention, And a valve body that divides the inside of the cylinder into two chambers, A tubular member provided at the axial center of the valve body, Rotatably provided in the hollow portion of the tubular member, A regulator having a notched flat portion on one side thereof, A port formed by radially penetrating the peripheral wall of the tubular member; Is formed on the regulator that matches the port, A communication passage that forms a variable throttle with the port based on the rotation of the adjuster; A flow path communicating between the two chambers via the port and the communication passage, Positioned and fixed to a tubular member on the same plane as the flat portion of the adjuster, The means is provided with a stopper member having a protrusion that regulates the rotation range of the adjuster by contacting the flat portion on the inner peripheral side of the central hole through which the adjuster is inserted.

[0009]

[Action]

 In the variable damping force type shock absorber of the present invention, the throttle opening degree of the variable throttle portion interposed in the middle of the flow path is changed by rotating the adjuster, whereby the damping force range of the shock absorber is changed. Can be changed.

The adjuster has its rotation range restricted by the flat portion of the adjuster contacting the protrusion of the stopper member. The protrusion has a notch shape on one side of the adjuster. Since the stopper member is formed so as to project to the flat portion side, the outer diameter of the stopper member can be reduced, and thus the versatility of the applied shock absorber size can be increased.

Further, when the stopper is formed, only the flat portion is formed in a notched shape on the adjuster side, and there is no need for a step of press-fitting a pin that gives an impact to the adjuster. It is possible to avoid deterioration of the dimensional accuracy due to the deformation of the adjuster that occurs.

[0012]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the configuration of the embodiment will be described. FIG. 1 is a cross-sectional view showing a main part of a damping force variable type shock absorber according to an embodiment of the present invention, in which 1 denotes a cylindrical cylinder. The cylinder 1 is divided into an upper chamber A and a lower chamber B by a piston (valve body) 2 slidably mounted, and both chambers A and B are filled with fluid such as oil.

The piston 2 is attached to a tip small diameter portion 3 a of a stud (cylindrical member) 3. The stud 3 is screwed and attached to the outer peripheral threaded portion 18a of the rebound stopper 18 which is screwed and attached to the tip threaded portion 17a of the piston rod 17.

That is, the pressure side check body 7, the pressure side check valve 8, the washer 5a, the collar 4a, the washer 5b, the pressure side damping valve 6, the piston 2, the extension side damping valve 9, and the washer 5c are attached to the tip small diameter portion 3a of the stud 3. The extension side check body 10, the extension side check valve 11, the washer 5d, and the collar 4b are sequentially mounted, and finally they are fastened with the nut 16.

Further, the stud 3 has a through hole (hollow portion) 3b formed in the shaft core portion thereof, and the first port 3c, the first port 3c, and the first port 3c in order from the top in a state of penetrating the peripheral wall in the diameter direction. Two ports 3d, a third port 3e, a fourth port 3f and a fifth port 3g are provided. The second port 3d and the third port 3e are formed at the same axial position. Further, only the second port 3d and the fourth port 3f are formed at the same position in the circumferential direction, but the other first, third, and fifth ports 3c, 3e, and 3g are at positions shifted in the circumferential direction. Is formed (see FIGS. 4, 5 and 6).

Further, an adjuster 12 is rotatably provided in the through hole 3b of the stud 3 by being sandwiched between an annular upper bush 13 and a lower bush 14. The adjuster 12 is formed in a tubular shape having a hollow portion 12a whose lower end communicates with the lower chamber B at the axial center portion, and the peripheral wall thereof has the first port 3c and the hollow portion. First lateral hole 12b communicating with 12a, vertical groove (communication passage) 12c communicating with second port 3d, fourth port 3f, and fifth port 3g, and third port 3e communicating with hollow portion 12a. A second lateral hole (communication passage) 12d is formed.

In the embodiment of the present invention, there are four flow paths shown in the drawing as the flow paths through which the fluid can flow. That is, the inside and the outer peripheral portion of the extension side damping valve 9 are opened from the position of the extension side inner groove 2f and the extension side first flow path D reaching the lower chamber B and the second port 3d and the fourth port 3f are passed. Then, the outer peripheral portion of the extension side damping valve 9 is opened from the position of the extension side outer groove 2g to reach the lower chamber B via the extension side second flow path E, the second port 3d and the fifth port 3g. The expansion-side check valve 11 is opened to reach the lower chamber B, and the expansion-side third flow passage F is provided, and the bypass passage G is provided to the lower chamber B via the third port 3e and the hollow portion 12a.

On the other hand, there are three flow paths shown in the figure as paths through which the fluid can flow in the pressure stroke. That is, the compression-side damping valve 6 is opened to the upper chamber A, and the pressure-side check valve 8 is opened to the upper chamber A via the hollow portion 12a and the first port 3c. The pressure side second flow path J and the bypass flow path G reaching the upper chamber A via the hollow portion 12a and the third port 3e.

A large diameter hole 3h having a diameter larger than that of the through hole 3b is formed on the upper end surface side of the stud 3, and a large diameter hole 3h is formed between the annular bottom portion of the large diameter hole 3h and the annular lower end surface of the rebound stopper 18. The upper bush 13 and the stopper plate (stopper member) 19 are provided in a sandwiched state in this order. The upper bush 13 accommodates a thrust washer 20 and a steel plate thrust washer 21 made of a low friction material on the lower end surface facing the upper end surface of the adjuster 12, and the upper end of the adjuster 12 can be rotatably inserted. A large diameter hole 13a is formed.

Further, the stopper plate 19 is for restricting the rotation range of the adjuster 12 in order to set the origin of the step motor, and as shown in FIGS. 2 and 3, the upper end of the adjuster 12 is adjusted. It is formed in an annular shape having a central hole 19a for rotatably inserting the portion, and a pair of semi-circular protrusions (positioning protrusions) 19b are formed on the outer peripheral portion so as to face each other in the radial direction. A pair of stopper portions (projections) 19c are formed on the inner peripheral portion so as to face each other in the radial direction. Further, on the inner peripheral wall surface of the large diameter hole 3h, semicircular positioning vertical grooves 3j, 3j capable of mounting and locking both semicircular projections 19b are formed by drilling.

On the other hand, the upper end of the adjuster 12 inserted into the through hole 19a is formed into a flat plate having a pair of parallel flat parts (flat parts) 12e, 12e by cutting both side surfaces. In addition, the rotation range is regulated by contacting the two flat portions with the stopper portions 19c.

Further, the rotation of the adjuster 12 is performed by the control rod 15, which extends through the through hole 17b of the piston rod 17 and extends to the upper end. A step motor provided on a vehicle body mounting portion (not shown) 17 allows step rotation.

Based on the rotation of the adjuster 12, the damping force position can be switched to any position within the range of the three positions shown in FIGS. 4 to 6.

First, in the first damping force position shown in FIG. 5, all of the first to fifth ports 3c, 3d, 3e, 3f, 3g are opened, and the four flow paths D, E in the extension stroke are described. , F, G, and all three flow paths H, J, G in the pressure stroke are allowed to flow.

Further, in the second damping force position shown in FIG. 4, only the first port 3c is opened, and the other second to fifth ports 3d, 3e, 3f, 3g are closed, and the first extension side first. The flow path D, the pressure-side first flow path H, and the pressure-side second flow path J can flow.

Further, in the third damping force position shown in FIG. 6, the second port 3c, the fourth port 3f and the fifth port 3g are opened, and the first port 3c and the third port 3e are closed, The expansion side first to third flow paths D, E, F and the compression side first flow path H are allowed to flow.

When the adjuster 12 is rotated counterclockwise to switch from the first damping force position shown in FIG. 5 to the second damping force position shown in FIG. 4, the second to fifth ports are rotated. The opening degree can be narrowed to change the flow passage cross-sectional areas of the bypass flow passage G, the expansion-side second flow passage E, and the expansion-side third flow passage F so as to decrease.

When the adjuster 12 is rotated clockwise to switch from the first damping force position shown in FIG. 5 to the third damping force position shown in FIG. 6, the first port and the third port are rotated. The degree of opening can be reduced so that the flow passage cross-sectional areas of the bypass flow passage G, the pressure-side second flow passage J, and the extension-side third flow passage F can be reduced.

As described above, the expansion side / pressure side common variable throttle portion R is formed between the third port 3e and the second lateral hole 12d, and the expansion side first variable throttle portion R is formed between the second port 3d and the vertical groove 12c. 1 variable throttle S is formed, a stretch side second variable throttle T is formed between the fourth port 3f and the vertical groove 12c, and a third stretch variable side is formed between the fifth port 3g and the vertical groove 12c. The throttle portion U is formed, and the pressure side variable throttle portion V is formed between the first port 3c and the first lateral hole 12b.

Next, the operation of the embodiment will be described. (A) At the time of starting damping force control When starting damping force control of the shock absorber, first, the origin of the step motor is set. In other words, the origin of this step motor is set to rotate the adjuster 12 side to the basic origin position because the step motor itself can rotate 360 degrees and there is no basic zero point. Then, a large drive current is supplied to the step motor for a predetermined time until the flat portions 12e, 12e of the adjuster 12 contact the stopper portions 19c, 19c of the stopper member 19. Then, by rotating the step motor from this origin position by a predetermined step, switching to an arbitrary damping force position is performed.

(B) At the time of controlling the first damping force position At the first damping force position shown in FIG. 5, all of the first to fifth ports 3c, 3d, 3e, 3f, 3g are opened, and the extension stroke is performed. All of the four flow paths D, E, F, and G in FIG. 3 and the three flow paths H, J, and G in the pressure stroke can flow. Therefore, during the extension stroke, in the low piston velocity range, the fluid flows through the bypass passage G having the smallest flow resistance, and as the piston velocity increases, the extension side third passage F, the extension side second passage E, The flow starts in the order of the stretch-side first flow path D, whereby the damping force range of the stretching process is in the soft range. On the other hand, during the pressure stroke, in the low piston velocity range, the fluid flows through the bypass passage G having the smallest flow resistance, and as the piston velocity increases, the pressure side second flow passage J and the pressure side first flow passage D are separated. The circulation starts in order, and as a result, the damping force range of the pressure stroke also becomes a soft range.

(C) At the time of controlling the second damping force position At the second damping force position shown in FIG. 4, only the first port 3c is opened and the other second to fifth ports 3d, 3e, 3f, 3g are closed. Therefore, the expansion-side first flow passage D 1, the compression-side first flow passage H, and the compression-side second flow passage J can flow. Therefore, during the extension stroke, the fluid opens the extension-side damping valve 9 and flows through the extension-side first flow path D, whereby the damping force range of the extension stroke is in the hard range. On the other hand, during the pressure stroke, in the low piston speed range, the fluid flows through the pressure side second flow path J having a small flow resistance, and in the high piston speed range flows through the pressure side first flow path H, whereby the damping of the pressure stroke occurs. The force range is in the soft range.

(D) At Third Damping Force Position Control At the third damping force position shown in FIG. 6, the second port 3c, the fourth port 3f, and the fifth port 3g are opened, and the first port 3c and the third port are opened. 3e is closed, and the expansion side first to third flow paths D, E, F and the compression side first flow path H are allowed to flow. Therefore, during the extension stroke, in the low piston velocity range, the fluid flows through the extension side third flow passage F having a small flow resistance, and as the piston velocity increases, the extension side second flow passage E and the extension side first flow passage As a result, the damping force range of the extension stroke becomes a soft range. On the other hand, at the time of the pressure stroke, the fluid opens the pressure side damping valve 6 and flows through the pressure side first flow path H, whereby the damping force range of the pressure stroke becomes a hard range.

(E) During control between first damping force position and second damping force position The adjuster 12 is rotated counterclockwise in order to switch from the first damping force position shown in FIG. 5 to the second damping force position direction shown in FIG. When it is rotated to, the opening degree of the second to fifth ports is narrowed, and the flow path cross-sectional area of the bypass flow path G, the expansion side second flow path E, and the expansion side third flow path F is reduced. Therefore, the damping force of the stroke gradually increases in proportion to the decrease in the flow passage cross-sectional area. That is, by rotating the adjuster 12 counterclockwise from the first damping force position position, the damping force range on the compression stroke side remains in the soft range state, and only the damping force range on the extension stroke side is set in the hard range direction. Can be changed to.

(F) During Control Between First Damping Force Position and Third Damping Force Position The adjuster 12 is turned clockwise to switch from the first damping force position shown in FIG. 5 to the third damping force position direction shown in FIG. As it is rotated, the openings of the first port and the third port are reduced, and the flow passage cross-sectional areas of the bypass flow passage G, the pressure side second flow passage J, and the extension side third flow passage F decrease. Therefore, the damping force of the pressure stroke gradually increases in proportion to the reduction of the flow passage cross-sectional area. In other words, by rotating the adjuster 12 clockwise from the first damping force position position, the damping force range on the extension stroke side remains in the soft range state, and only the damping force range on the pressure stroke side is set to the hard range. You can change the direction.

As described above, in the damping force variable shock absorber of this embodiment, when the damping force range on the process side of either the extension stroke or the pressure stroke is the hard range, Since the damping force range is always in the soft range, it has the characteristic that a comfortable ride and steering stability can be ensured even for road surface inputs that combine low and high frequencies. is doing.

The adjuster 12 has its rotation range restricted by the flat surface portion 12e of the adjuster 12 contacting the stopper portion 19c of the stopper member 19, and the stopper portion 19c includes the adjuster 12c. Since the stopper member 19 is formed so as to project to the side of the flat surface portion 12e formed by cutting on both side surfaces, the outer diameter of the stopper member 19 can be reduced, thus increasing the versatility of the applicable shock absorber size. It has the feature of being able to.

Further, since only the flat surface portion is cut on the adjuster 12 side and there is no need for a step of press-fitting a pin that gives an impact to the adjuster 12, there is a possibility that the adjuster 12 may be deformed during the press-fitting step. It has a feature that deterioration of dimensional accuracy can be avoided.

Although the embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and there are design changes and the like within a range not departing from the gist of the present invention. Even included in the present invention.

For example, in the embodiment, the case where the adjuster is rotated is shown, but the rotation and the axial slide can be combined.

Further, in the embodiment, the piston is shown as the valve body, but it can be applied to other things such as a base that defines a chamber inside the cylinder and a reservoir chamber outside the cylinder.

[0042]

[Effect of the device]

 As described above, in the damping force variable type shock absorber of the present invention, the adjuster which is rotatably provided in the hollow portion of the tubular member and has the notched flat portion formed on one side surface thereof, Positioned and fixed to a tubular member on the same plane as the flat part of the adjuster, the flat part abuts on the inner peripheral side of the central hole through which the adjuster is inserted, and the protruding part that regulates the rotation range of the adjuster By adopting a means that includes a stopper member having, the flat plate part is only machined on the adjuster side, and there is no need for a process such as press fitting of a pin that gives an impact to the adjuster. The effect that the deterioration of the dimensional accuracy due to the deformation of the adjuster caused in the process can be avoided can be obtained.

Further, since the protruding portion of the stopper member is formed so as to protrude toward the flat portion formed in the notch shape on one side of the adjuster, the outer diameter of the stopper member can be reduced, This has the effect of increasing the versatility of the applied buffer size.

[Brief description of drawings]

FIG. 1 is a cross-sectional view (cross section P-P in FIG. 2) showing a main part of a damping force variable shock absorber according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line CC of FIG.

FIG. 3 is an exploded perspective view of an adjuster portion.

FIG. 4 is a sectional view showing a second damping force position position,
(A) is a sectional view taken along the line K-K in FIG. 1, and (b) is a line L-L and M in FIG.
-M sectional view, (C) is an N-N sectional view of FIG.

FIG. 5 is a sectional view showing a first damping force position position,
(A) is a sectional view taken along the line K-K in FIG. 1, and (b) is a line L-L and M in FIG.
-M sectional view, (C) is an N-N sectional view of FIG.

FIG. 6 is a cross-sectional view showing a third damping force position position,
(A) is a sectional view taken along the line K-K in FIG. 1, and (b) is a line L-L and M in FIG.
-M sectional view, (C) is an N-N sectional view of FIG.

[Explanation of symbols]

 A Upper chamber B Lower chamber F Expansion side third flow path (flow path) G Bypass flow path (flow path) J Pressure side second flow path (flow path) R Expansion side / pressure side common variable throttle section S Expansion side first variable Throttle portion U Expansion third variable throttle portion V Pressure side variable throttle portion 1 Cylinder 2 Piston (valve body) 3 Stud (cylindrical member) 3b Through hole (hollow portion) 3c 1st port 3d 2nd port 3e 3rd port 3f 4th port 3g 5th port 12 Adjuster 12c Vertical groove (communication passage) 12d Second lateral hole (communication passage) 12e Flat surface portion (flat portion) 19 Stopper plate (stopper member) 19a Central hole 19c Stopper portion (projection portion)

Claims (1)

[Scope of utility model registration request] 1. A valve body having a cylinder defined by two chambers, a tubular member provided at an axial center of the valve body, and rotatable in a hollow portion of the tubular member. An adjuster provided with a notched flat portion on one side thereof, a port formed by radially penetrating the peripheral wall of the tubular member, and an adjuster matching the port, A communication passage that forms a variable throttle portion with the port based on the rotation of the adjuster, a flow passage that communicates between the two chambers via the port and the communication passage, and a flat surface of the flat portion of the adjuster A stopper member that is positioned and fixed to the upper tubular member, and that has a protrusion that restricts the range of rotation of the adjuster by contacting the flat portion on the inner peripheral side of the central hole through which the adjuster is inserted. A variable damping force type shock absorber.