JP6750578B2 - shock absorber - Google Patents

Description

This invention relates to a shock absorber.

For example, Patent Document 1 discloses a shock absorber including a non-seating type damping force generating valve (a damping force generating valve for very low speed). The damping force generation valve includes a sealing ring (opposing member) and a non-seated leaf valve including a leaf (leaf valve element) opposed to the sealing ring via a clearance. The clearance (shortest distance) between the leaf and the sealing ring is about 10 μm.

JP, 2016-173140, A

As described in Patent Document 1, the clearance between the leaf of the non-seated leaf valve and the sealing ring facing the leaf is extremely small. When manufacturing a shock absorber, it is generally difficult to assemble the leaf having a thin plate thickness so that the above-mentioned minimum clearance is satisfied.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method of manufacturing a shock absorber capable of improving the assembling property of a non-seating type damping force generating valve.

A shock absorber manufacturing method according to the present invention includes a shock absorber including a non-seating damping force generating valve that includes a sealing ring and a non-seating leaf valve that includes a leaf that faces the sealing ring via a clearance. Is a manufacturing method.
The manufacturing method,
A forming step of integrally forming the sealing ring and the leaf through a cut for separating the sealing ring and the leaf,
An assembling step of assembling the non-seated leaf valve including the leaf in a state of being integrated with the sealing ring with the piston of the shock absorber;
A fixing step of fixing the sealing ring to the piston,
After the assembling step and the fixing step, by applying a load to the leaf, a separation step of separating the leaf and the sealing ring at the cut line,
Equipped with.

According to the present invention, a non-seated leaf valve including a leaf in a state of being integrated with a sealing ring through a cut is assembled to a piston, and after the sealing ring is fixed to the piston, in a separation step. The leaf and the sealing ring are separated from each other at the break. As a result, the leaf and the sealing ring can be assembled to the piston so that a very small clearance can be satisfied, without requiring a highly precise radial positioning step of the sealing ring, which is difficult to mechanize. Therefore, according to the present invention, the assembling property of the non-seating type damping force generating valve can be improved.

It is a sectional view showing composition around a piston of a shock absorber concerning an embodiment of the invention. It is sectional drawing which expanded and represented the structure around the damping force generating valve for minute low speeds shown in FIG. It is a perspective view for explaining the composition of the plate member manufactured by the formation process concerning this embodiment. It is the figure which looked at the plate-shaped member shown in FIG. 3 from the axial direction of a piston. It is a top view showing the example of the shape of the leaf (maximum leaf) of another non-seated leaf valve according to the present invention. It is a top view showing the example of the shape of the leaf (maximum leaf) of further another non-seated leaf valve concerning the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, in the following embodiments, when the number of each element, the number, the amount, the range, etc. is referred to, the reference is made unless otherwise specified or in principle specified by the number. The present invention is not limited to the number. Further, the structures and the like described in the embodiments below are not necessarily essential to the present invention, unless otherwise specified or clearly specified in principle.

1. Overall Structure of Shock Absorber FIG. 1 is a sectional view showing a structure around a piston 14 of a shock absorber 10 according to an embodiment of the present invention. As shown in FIG. 1, the shock absorber 10 includes a cylinder 12 and a piston 14 arranged in the cylinder 12. The piston 14 is fitted to the inner wall of the cylinder 12 so as to be capable of reciprocating. The cylinder 12 is filled with oil as a working liquid. The shock absorber 10 is applied to a vehicle as an example.

The piston 14 includes a rod portion 14R extending along the axis of the cylinder, and a piston body 14M attached to the lower end of the rod portion 14R. The upper end of the rod portion 14R is connected to a vehicle body (not shown) outside the cylinder 12, and the lower end of the cylinder 12 is connected to an unsprung member (not shown) of the vehicle.

As shown in FIG. 1, the piston body 14M is provided with a damping force generation valve 16 for extension stroke, a damping force generation valve 18 for compression stroke, and a damping force generation valve 20 for very low speed. Each of these damping force generation valves 16, 18 and 20 is configured to generate a damping force according to the speed of the piston 14. The damping force generation valves 16, 18 and 20, and the main body 14MM and the sub-body 14MS of the piston body 14M are attached to the rod portion 14R by a nut 24 that is screwed into a male screw 22 provided at the lower end of the rod portion 14R. It is attached to the lower end.

2. Structure around damping force generating valve for very low speed The damping force generating valve 20 for very low speed is a non-seating type damping force generating valve having a double-opening structure, and is suitable when the speed of the piston 14 is in a very low speed region. It is configured to generate force. FIG. 2 is an enlarged cross-sectional view of the structure around the very low speed damping force generating valve 20 shown in FIG.

As shown in FIG. 2, the very low speed damping force generation valve 20 includes a non-seated leaf valve 26 and a sealing ring 28. The non-seated leaf valve 26 includes a plurality of (for example, 5 sets) annular plate-shaped leaves 26 a, 26 b 1, 26 b 2, 26 c 1 and 26 c 2 having different radial lengths of the piston 14 stacked in the axial direction of the piston 14. Is configured. Hereinafter, among these leaves 26a and the like, the leaf 26a having the longest radial length of the piston 14 is referred to as a "maximum leaf 26a". The leaves 26b1 and 26b2 are configured to function as one leaf by combining two leaf elements as an example.

More specifically, one (one example) spacer 30 is arranged to provide a gap between the largest leaf 26a and the leaf 26b1 and between the largest leaf 26a and the leaf 26b2. This gap is provided in order to make it difficult to adsorb two adjacent leaves when the non-seated leaf valve 26 elastically deforms.

A leaf 26c1 is arranged on the surface of the leaf 26b1 opposite to the surface in contact with the spacer 30. Similarly, a leaf 26c2 is arranged on the surface of the leaf 26b2 on the side opposite to the surface in contact with the spacer 30. Two spacers 32 are arranged between the leaf 26c1 and the sub body 14MS, and one spacer 32 is arranged between the leaf 26c2 and the nut 24.

With the above configuration, each leaf 26a of the non-seated leaf valve 26 is cantilevered at the inner edge in the radial direction of the piston 14 while being sandwiched between the spacers 30 and 32 and the sub body 14MS and the nut 24. It is supported. The leaves 26a and the like are elastically deformed by the differential pressure generated in the cylinder 12 as the shock absorber 10 expands and contracts.

The maximum leaf 26a faces the sealing ring 28 via the clearance C. More specifically, the sealing ring 28 is arranged so as to face the free end of the maximum leaf 26a on the radially outer side of the non-seated leaf valve 26, and forms a clearance C with the free end. There is. The clearance C is a minimum clearance of about 10 μm that is required for the damping force generation valve 20 to appropriately suppress the oil leakage flow rate in a very low speed region so as to exhibit desired damping force characteristics.

The sealing ring 28 is formed of a substantially rigid material and has an annular plate shape. The sealing ring 28 is fixed by the ring fixing nut 34 while being sandwiched between the sub body 14MS and the ring fixing nut 34.

3. Method of manufacturing shock absorber 3-1. Problems in Manufacturing Shock Absorber When manufacturing the shock absorber 10, it is difficult to assemble the thin leaf maximum leaf 26a and the like so that the minimum clearance C is satisfied.

Specifically, it is required that the maximum leaf 26a be inserted and assembled inside the sealing ring 28 that requires the minimum clearance C. However, it is difficult to position the sealing ring 28 in the radial direction during such assembling work. Therefore, it is difficult to mechanize the above assembling work (automation of assembling), and instead of this, for example, the following work by human hands is required. That is, after the non-seated leaf valve 26 including the maximum leaf 26a is fixed to the piston 14 by the nut 24, the sealing ring 28 is pressed against the sub-main body 14MS while adjusting the position in the radial direction, and the sealing ring 28 is pressed. It is necessary to fix the ring fixing nut 34 while paying attention not to shift it in the radial direction. Therefore, there is a concern that the assembly cost will increase. Further, it is necessary to perform grinding in order to ensure the accuracy of the outer diameter of the largest leaf 26a and the inner diameter of the sealing ring 28 with high accuracy, which may increase the processing cost.

3-2. Each step of the characteristic manufacturing method according to the embodiment The manufacturing method of the shock absorber 10 according to the present embodiment includes a forming step, an assembling step, a fixing step, and a separating step shown below.

3-2-1. Forming Process FIG. 3 is a perspective view for explaining the configuration of the plate-shaped member 36 manufactured by the forming process according to the present embodiment, and FIG. 4 illustrates the plate-shaped member 36 shown in FIG. It is the figure seen from the direction. The plate-shaped member 36 shown in FIGS. 3 and 4 has a portion corresponding to the maximum leaf 26a and the sealing ring 28 via a cut 38 for separating the plate-shaped member 36 into the maximum leaf 26a and the sealing ring 28. Has a portion corresponding to. In this example, the cut 38 is formed in a circular shape centered on the axial center of the piston 14. In the forming step, the plate-like member 36 in which the maximum leaf 26a and the sealing ring 28 are physically integrated via the cut 38 is thus formed.

In the example shown in FIGS. 3 and 4, the cut 38 is formed over the entire boundary (entire circumference) between the portion corresponding to the maximum leaf 26a and the portion corresponding to the sealing ring 28. However, the cut 38 is only required to prevent the plate-shaped member 36 from separating into the maximum leaf 26a and the sealing ring 28 before proceeding to the separation step described below. Therefore, the break 38 may be provided, for example, in a part of the boundary, and the remaining boundary where the break 38 is not provided may be separated into the maximum leaf 26 a and the sealing ring 28.

3-2-2. Assembling Step In this assembling step, after the forming step, the non-seated leaf valve 26 including the maximum leaf 26a (that is, the plate member 36) integrated with the sealing ring 28 is attached to the spacer 30 and the spacer. This is a step of assembling with the rod portion 14R of the piston 14 together with 32.

More specifically, the sub-body 14MS is followed by two spacers 32, a leaf 26c1, a leaf 26b1, a spacer 30, a plate member 36 (the sealing ring 28) so that the arrangement order shown in FIG. The nut 24 is tightened with the maximum leaf 26a), the spacer 30, the leaf 26b2, the leaf 26c2, and the spacer 32 inserted in the rod portion 14R in this order. As a result, the non-seated leaf valve 26 is fixed to the piston 14.

3-2-3. Fixing Step This fixing step is a step of fixing the sealing ring 28 to the piston 14 after the assembling step. More specifically, the ring fixing nut 34 is tightened with the sealing ring 28 integrated with the largest leaf 26a being sandwiched between the sub body 14MS and the ring fixing nut 34. By this fixing step, not only the portion corresponding to the maximum leaf 26a of the plate-shaped member 36 but also the portion corresponding to the sealing ring 28 of the plate-shaped member 36 is fixed to the piston 14 by the above-mentioned assembly process.

3-2-4. Separation Step This separation step is a step of separating the maximum leaf 26a and the sealing ring 28 with the cut 38 as a boundary by applying a load to the maximum leaf 26a after the fixing step. As shown in FIGS. 3 and 4, the cut 38 has a circular shape. Therefore, the separation step yields a maximum leaf 26a having a circular outer edge portion in the shape of a circle, and a corresponding sealing ring 28 having a radially inner edge portion having a circular shape.

4. Effect of the method for manufacturing the shock absorber according to the embodiment According to the method for manufacturing the shock absorber 10 according to the present embodiment described above, the maximum leaf 26a and the sealing ring 28 are formed as the plate-shaped member 36 via the cut 38. After being assembled to the piston 14 in an integrated state, they are separated. As a result, the maximum leaf 26a and the sealing ring 28 that satisfy the extremely small clearance C can be obtained while eliminating the need for a highly accurate radial positioning process of the sealing ring 28, which is difficult to mechanize. This enables mechanization (automatic assembly) of the non-seated leaf valve 26 and the sealing ring 28, so that the assembly cost can be kept low. Further, since it is not necessary to grind the outer diameter of the maximum leaf 26a and the inner diameter of the sealing ring 28 with high accuracy, it is possible to suppress the processing cost.

5. Other Shape Examples As described above, the maximum leaf 26a is assembled to the piston 14 in a state where it is integrated with the sealing ring 28 through the cut 38, whereby the radial positioning step of the sealing ring 28 is performed. Can be eliminated. Accordingly, the shape of the non-seated leaf valve (in particular, the leaf that faces the sealing ring through the clearance) does not need to be circular. Therefore, the shape of the leaf according to the present invention may be, for example, various shapes as described below, instead of the above-described circular shape, and other than the examples shown below, for example, a rectangular shape. May be. By adopting such an example of another shape, more complicated characteristics can be given to the damping force generating valve including the non-seated leaf valve.

5-1. Example of Oval Shape FIG. 5 is a plan view showing an example of the shape of a leaf (maximum leaf) 44 of another non-seated leaf valve according to the present invention. The plate-shaped member 40 of this example has a portion corresponding to the largest leaf 44 and a portion corresponding to the sealing ring 46 via the elliptical cut 42. When a shock absorber is manufactured using this plate member 40, an elliptical maximum leaf 44 can be obtained.

5-2. Example of Petal Shape FIG. 6 is a plan view showing an example of the shape of a leaf (maximum leaf) 54 of still another non-seated leaf valve according to the present invention. The plate-shaped member 50 of this example has a portion corresponding to the largest leaf 54 and a portion corresponding to the sealing ring 56 via the petal-shaped cut 52. When a shock absorber is manufactured using this plate-shaped member 50, a petal-shaped maximum leaf 54 can be obtained.

10 Shock Absorber 12 Cylinder 14 Piston 14M Piston Body 14MM Main Body 14MS Main Body 14MS Sub Body 14R Piston Rod 16 Damping Force Generating Valve for Extension Stroke 18 Damping Force Generating Valve for Compression Stroke 20 Damping Force Generating Valve for Minute Slowness 24 Nut 26 Non-seated leaf valve 26a, 44, 54 Maximum leaf 28, 46, 56 Sealing ring 30 Spacer 32 Spacer 34 Ring fixing nut 36, 40, 50 Plate-shaped member 38, 42, 52 Cut

Claims (1)

A ring for sealing,
A non-seated leaf valve including a leaf facing the sealing ring through a clearance;
A method for manufacturing a shock absorber comprising a non-seated damping force generation valve comprising:
A forming step of integrally forming the sealing ring and the leaf through a cut for separating the sealing ring and the leaf,
An assembling step of assembling the non-seated leaf valve including the leaf in a state of being integrated with the sealing ring with the piston of the shock absorber;
A fixing step of fixing the sealing ring to the piston,
After the assembling step and the fixing step, by applying a load to the leaf, a separation step of separating the leaf and the sealing ring at the cut line,
A method of manufacturing a shock absorber, comprising:

Images