JP2886372B2 - Manufacturing method of compression ring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a process for the preparation of compression-rings for internal combustion engine or compressor.

[0002]

2. Description of the Related Art In recent years, a compression ring has been subjected to a nitriding treatment. Nitriding is performed by gas nitriding or salt bath nitriding. According to this method, not only the outer peripheral surface but also the upper and lower surfaces and the inner peripheral surface are nitrided.

[0003]

As described above, since nitriding enters the entire circumference of the cross section of the ring, when the ring having a small ring width and having a notch at the end of the joint is subjected to thick nitriding, the end of the joint is cut off. The brittleness of the notched portion having a small area is increased by nitriding, the strength is reduced, and there is a possibility that the notched portion may be broken. Therefore, it is not possible to meet the demand for a thinner ring and higher wear resistance.

[0004] It is an object of the present invention to provide a compression ring having a notch at the end of the abutment to meet the demand for a thinner ring and wear resistance while maintaining breaking strength.

[0005]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
In addition, the present invention provides a step of coiling and forming a steel wire,
Cut the coil material obtained by the coiling molding
A step of obtaining a ring having an abutment;
Forming a notch in the portion,
Nitriding process to form a nitrided layer only on the outer peripheral surface
And subjecting the nitrided ring to a soft surface treatment.
At least the upper and lower surfaces of the lower surface and the inner peripheral surface are soft surface treatments.
Forming a physical layer and finishing the soft surface-treated ring
And a step of performing processing. Above
Alternatively, the following may be performed. That is, coiling steel wire
And forming by the coiling molding.
Ion nitriding treatment of the coil material
Forming a nitrided layer and cutting the coil material after nitriding.
Obtaining a ring having an abutment, and an abutment of the ring
A step of notching the end, and a
Of the upper and lower surfaces and the inner peripheral surface
Forming a soft surface treatment layer on at least the upper and lower surfaces,
Subjecting the soft surface treatment ring to a finishing process.
It is characterized by that. Furthermore, you may do the following
No. That is, the step of coiling and forming a steel wire,
Cut the coil material obtained by the coiling molding
A step of obtaining a ring having an abutment;
A step of forming a nitrided layer only on the outer peripheral surface by performing a nitriding treatment
And performing a notch process at the joint end of the nitride ring
And subjecting the notched ring to soft surface treatment
At least one of the upper and lower surfaces and the inner peripheral surface
A step of forming a surface treatment layer;
And performing a finishing process.

[0006]

As the soft surface treatment, a phosphate film treatment, a ferrox film treatment, a sulfide film treatment, a tin plating, a soft alloy plating, a copper plating, a fluoride resin film treatment, or a composite film treatment of these is performed. .

[0008]

The compression ring is provided with an ion-nitrided layer only on the outer peripheral surface, so it has good wear resistance against sliding with the cylinder, and the upper and lower surfaces or the upper and lower surfaces and the inner peripheral surface have a soft surface treatment layer. Since it is formed, it has excellent corrosion resistance and can prevent abnormal wear of the oil ring groove.

[0009] By selecting an ion nitriding treatment having a processing directivity as the nitriding treatment, the upper and lower surfaces and the inner peripheral surface of the compression ring are nitrided without performing a special nitridation preventing treatment or a removal treatment of the nitrided layer. Instead, nitriding can be easily performed only on the outer peripheral surface. Also, since nitriding can be performed only on the outer peripheral surface, even if a notch is provided at the end of the joint and thick nitriding is applied to a ring with a small ring width, the breaking strength of the notch with a small cross-sectional area at the end of the joint is maintained. Thus, a ring having a small ring width, breaking strength, and excellent wear resistance can be obtained. In particular, a ring width of 1.2 mm or less,
The effect is great when the nitride layer thickness is 70 μm or more.

[0010]

In FIG. 2, an outer peripheral surface of an aluminum alloy piston 1 has two compression ring grooves 2A,
3A and one oil ring groove 4A are formed. The top ring 2 is formed in the uppermost compression ring groove 2A, the second ring 3 is formed in the compression ring groove 3A below the compression ring groove 2A, and the oil ring groove 4A is formed in the lower compression ring groove 3A. Is provided with an oil ring 4.

The top ring 2 has a barrel-shaped outer periphery and a right-angled abutment structure. The ion nitriding layer 5 is formed only on the outer peripheral surface, and is pressed against the inner wall surface 20 of the cylinder 19. The upper and lower surfaces of the ring and the inner peripheral surface form a soft surface treatment layer 21.

The second ring 3 has a structure having a notch at the end of the abutment, the ion nitriding layer 6 is formed only on the outer peripheral surface, and is pressed against the inner wall surface 20 of the cylinder 19. The upper and lower surfaces of the ring and the inner peripheral surface form a soft surface treatment layer 22.

As shown in FIG. 1, the abutment structure of the second ring 3 has a cutout 9 which is open to the outer peripheral surface of the ring and the abutment end surface 8 on the upper surface of the ring at one end of the abutment. And a notch is also formed at the other end of the joint,
A projecting portion 11 disposed in the notch 9 is formed so as to protrude at a position facing the notch 9 on the abutting end face 10 of the abutting end. The notch 9 and the protruding portion 11 have the same triangular cross section in the radial direction, and the slope 13 of the protruding portion 11 is disposed on the slope 12 of the notch 9. It is attached to the ring groove 3A with a predetermined gap. Although the cross-sectional shapes of the notch 9 and the protruding portion 11 are triangular in the above description, the present invention is not limited to this, and other shapes such as a rectangular shape may be used.

The oil ring 4 is a two-piece steel combination oil ring, which is fitted on an oil ring main body 16 having rails 14 and 15 on the upper and lower sides and having an approximately I-shaped cross section and an inner periphery of the oil ring main body 16. The rails 14 and 15, each of which has a hard chrome plating 18 formed on the outer peripheral surface thereof, are pressed against the inner wall surface 20 of the cylinder 19 by the coil expander 17. Oil ring body 1
The surface other than the outer peripheral surface of No. 6 forms a soft surface treatment layer 23.

Hereinafter, an example of a method for manufacturing the second ring 3 will be described. Martensitic stainless steel wire rod
Make coil material by coiling , cut it and
After obtaining the ring having an abutment joint, subjected to notch processing abutment end, then the stack form by inserting a plurality of-ring on the outer circumference of the cylindrical jig, it ends in the axial direction by the clamp disc After fastening and fixing, the outer peripheral surface was subjected to nitriding treatment in an ion nitriding furnace. Conditions of the ion nitriding, for example, ambient gas composition nitrogen: hydrogen = 7: Thus 3 work temperature 500 ° C., to obtain an ion nitriding layer of H V 700 or more depth 70μm in the ring outer peripheral surface.

The ion nitriding of the outer peripheral surface can be performed at the stage of the coil material .

In the ion nitriding, since the discharge occurs only on the outer peripheral surface of the work, the outer periphery of the ring is nitrided, but the upper and lower surfaces are in contact with each other with no gap, and the inner periphery is in contact with the cylindrical surface of the jig. Therefore, no discharge occurs, and a ring having no nitrided layer on the upper, lower, and inner peripheral surfaces can be obtained.

After the ion nitriding treatment, soft surface treatment layers were formed on the upper and lower surfaces and the inner peripheral surface. Soft surface treatments include phosphate coating, ferrox coating, sulfide coating,
A tin plating, a soft alloy plating, a copper plating, a fluororesin coating treatment, or a combination of these treatments is applied.

Thereafter, finishing was carried out by a conventional method.

The structure of the abutment end to which the present invention is applied is not limited to the structure shown above, but may be, for example, those shown in FIGS. 3, 4 and 5. The one shown in FIG. 3 is a stepped joint structure, which has a cutout portion 30 at the lower part of one joint end and a notch 31 at the upper part of the other joint end. The protrusions 32 and 33 at the abutment ends are vertically arranged. The ion nitriding layer 6A is formed only on the outer peripheral surface of the ring, and the upper and lower surfaces of the ring and the inner peripheral surface are formed of a soft surface treatment layer 22A. Is formed.

FIGS. 4 and 5 show an abutment end structure as a ring detent, and FIG. 4 shows a side detent.
Notches 34, 35 are provided at the upper end of the two ends, and a detent pin 36 (projecting into the ring groove of the piston) is disposed in each of the notches 34, 35. The upper and lower surfaces of the ring and the inner peripheral surface form a soft surface treatment layer 22B, and FIG. 5 shows the inner peripheral detent, and a notch is formed at the inner peripheral end of both ends. 3
7 and 38, and a non-rotating pin 39 (protruding from the ring groove of the piston) is arranged in the cutouts 37 and 38. The ion nitrided layer 6C is formed only on the outer peripheral surface of the ring.
Is formed, and the upper and lower surfaces of the ring and the inner peripheral surface are formed of a soft surface treatment layer 2.
2C is formed.

In the above description, an example is shown in which the abutment end structure having the notch is applied to the second ring 3, but it goes without saying that the present invention can be applied to other compression rings such as a top ring. And in that case,
An ion nitriding layer is formed only on the outer peripheral surface of the ring, and a soft surface treatment layer is formed on the upper and lower surfaces of the ring or on the inner and outer surfaces of the ring.

[0023]

[0024]

As described above, according to the present invention, nitriding can be easily performed only on the outer peripheral surface requiring abrasion resistance by ion nitriding. Also, since nitriding can be performed only on the outer peripheral surface, even if a notch is provided at the end of the joint and thick nitriding is applied to a ring with a small ring width, the breaking strength of the notch with a small cross-sectional area at the end of the joint is maintained. Thus, a ring having a small ring width, breaking strength, and excellent wear resistance can be obtained. Change
And soft surface treatment on the upper and lower surfaces or the upper and lower surfaces and the inner peripheral surface.
As a result, it has excellent corrosion resistance and abnormal wear of the ring groove.
A ring that can be prevented is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an abutment portion of a second ring.

FIG. 2 is a sectional view of a main part of a piston inserted into a cylinder.

FIG. 3 is a front view showing a joint portion of a ring.

FIG. 4 is a front view showing a joint portion of a ring.

FIG. 5 is a plan view showing a joint portion of a ring.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Piston 2 Top ring 2A Top ring groove 3 Second ring 3A Second ring groove 4 Oil ring 4A Oil ring groove 5, 6, 6A, 6B, 6C Ion nitriding layer 8, 10 Abutment end face 9 Notch 11 Projection 12, 13 Bevel 16 Oil ring main body 17 Coil expander 18 Hard chrome plating 19 Cylinder 20 Cylinder inner wall surface 21, 22, 22A, 22B, 22C, 23 Soft surface treatment layer 30, 31, 34, 35, 37, 38 Notch 32, 33 Projection 36, 39 Lock pin

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16J 9/00-9/28

Claims (4)

(57) [Claims] 1. A step of coiling and forming a steel wire rod.
Cut the coil material obtained by the coiling molding
A step of obtaining a ring having an abutment;
Forming a notch in the portion,
Nitriding process to form a nitrided layer only on the outer peripheral surface
And subjecting the nitrided ring to a soft surface treatment.
At least the upper and lower surfaces of the lower surface and the inner peripheral surface are soft surface treatments.
Forming a physical layer and finishing the soft surface-treated ring
And a step of processing.
Method for manufacturing shock rings. 2. A step of coil forming a steel wire rod.
The coil material obtained by coiling
Forming a nitrided layer only on the outer peripheral surface by performing
Cut the coil material after nitriding to form a ring with a joint
A step of obtaining and a step of performing notch processing at the end of the abutment of the ring.
The softened surface is applied to the notched ring.
At least the upper and lower surfaces of the inner and outer surfaces
Forming a surface treatment layer; and the soft surface treatment ring.
Subjecting the surface to a finishing process.
Production method of compression ring. 3. A step of coiling and forming a steel wire.
Cut the coil material obtained by the coiling molding
A step of obtaining a ring having an abutment;
A step of forming a nitrided layer only on the outer peripheral surface by performing a nitriding treatment
And performing a notch process at the joint end of the nitride ring
And subjecting the notched ring to soft surface treatment
At least one of the upper and lower surfaces and the inner peripheral surface
A step of forming a surface treatment layer;
A step of performing a finishing process.
Manufacturing method of the restoring ring. 4. The soft surface treatment is a phosphate film treatment,
Rox coating, sulfide coating, tin plating, soft
Alloy plating, copper plating, fluororesin coating treatment, or
Claims characterized by these composite coating treatments
Manufacture of compression rings according to 1, 2, or 3
Method.