JP2002323133A - Wire for pressure ring, pressure ring and method of making the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of chips or the like at coiling times or the like of a wire for a pressure ring, facilitate discrimination of the upper/lower in two surfaces which serve as the upper/lower surface of a ring in the wire for the pressure ring, and to provide a method of making the pressure ring using the wire for the pressure ring and the pressure ring of high performance at a low cost. SOLUTION: A surface 2, serving as the external peripheral surface of a ring of a wire 1, is formed with a tapered surface 2A, a flat surface 2B, and an end part outside protrusion preventing surface 2C. The end part outside protrusion preventing surface 2C is recessed to the side of a surface 3 serving as an internal peripheral surface of the ring from the flat surface 2B. The width of the flat surface 2B is 0.05 to 0.3 mm, and the tilt angle of the tapered surface 2A is 0.5 to 5 deg.. The upper/lower angular part of the surface 2 serving as the external peripheral surface of the ring in the wire 1 is formed chamfered, the chamfer 6 on the upper side is larger than the chamfer 7 on the lower side. A surface 4, serving as an upper surface of the ring, is formed with a recessed groove 8 along the longitudinal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire for manufacturing a pressure ring used in an internal combustion engine, a compressor, and the like, a pressure ring, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Improvements in the strength, wear resistance, seizure resistance, gas sealability, and oil scraping ability of piston rings have also been made in response to recent high output, low fuel consumption, long life, and compliance with exhaust gas regulations of internal combustion engines. And low cost is required. In order to satisfy these requirements, the material of the piston ring has been shifted from cast iron to steel. In the pressure ring, valve spring steel is used and hard Cr plating is applied, or stainless steel is used and nitriding is applied. These pressure ring manufacturing methods include a step of coiling (spiral winding) a band-shaped wire, a step of cutting the coiled wire to obtain a ring, a step of performing a surface treatment on the ring, and a surface treatment step. Polishing the upper and lower surfaces of the ring, the outer peripheral surface, and the end surface of the abutment before or after the step (a). In the manufacture of the ring, it is desirable that the cross-sectional shape of the strip-shaped wire be as close as possible to the shape of the completed ring, since subsequent processing can be simplified. JP-A-8-2
No. 96497 describes a wire having an irregular cross-sectional shape, and the outer peripheral surface of the ring is formed into a tapered shape or a barrel shape to greatly reduce the processing.

[0003]

A pressure ring having a tapered outer peripheral shape is provided with a flat portion to secure an initial contact with the inner peripheral surface of the cylinder. However,
In the prior art such as Japanese Patent Application Laid-Open No. 8-296497, there is no recognition of the importance of providing a flat portion on the outer peripheral surface of the ring of the wire, and the value of the flat portion and tolerance are described in the specification of the cross-sectional shape of the wire. Therefore, a flat portion is provided by polishing such as lapping during finishing. Therefore, much time is required for polishing the flat portion. In addition, in the conventional wire rod described above, since the end of the tapered surface is sharp, chipping or damage occurs when the end of the tapered surface comes into contact with the jig during coiling of the wire or subsequent polishing. There is. On the other hand, since the inclination angle of the tapered surface is small, it is difficult to distinguish between the upper and lower surfaces on the upper and lower surfaces of the ring. As a result, when processing is performed in a state where the upper and lower surfaces are inverted in the processing step, or when a mark indicating the upper surface is erroneously displayed on the lower surface, the pressure ring is attached to the piston in the opposite direction. .

[0004] The present invention has been made in view of the above points, and an object of the present invention is to cause chipping or flaws in the end portion of the outer peripheral surface of the ring when coiling or polishing a wire. The object of the present invention is to provide a wire for a pressure ring which prevents the occurrence of the pressure. Another object of the present invention is to provide a wire for a pressure ring in which upper and lower surfaces can be easily distinguished from each other on the upper and lower surfaces of the ring. Still another object of the present invention is to provide a method for manufacturing a pressure ring using the wire for a pressure ring, and an inexpensive and high-performance pressure ring obtained by the method.

[0005]

The present invention employs the following means in order to solve the above-mentioned problems. That is, the wire for a pressure ring of the present invention is formed by a flat surface and a tapered surface which is inclined toward the surface which becomes the inner peripheral surface of the ring and is continuous with the flat surface. The width of the flat surface is 0.05 to 0.3 mm, and the inclination angle of the tapered surface is 0.5 to 5 ° (claim 1).

According to the above configuration, in a manufacturing process such as a coiling process and a polishing process, the jig and the wire come into contact with each other via the flat surface of the wire, and the wire is chipped as compared with a conventional tapered surface alone. And the occurrence of scratches can be prevented. In addition, when performing surface treatment such as nitriding treatment, hard Cr plating, PVD,
In the case of the conventional taper surface alone, chipping is likely to occur at the sharp edge portion. However, in the case of the present invention, since the flat surface following the taper surface is provided, the occurrence of chipping in the surface treatment portion can be prevented. In addition, since a flat surface is provided in advance on the wire, polishing time such as lapping of the flat surface can be reduced. Also,
The tapered surface may be a plastically processed surface at the time of roll forming or drawing by a die, and can be sufficiently coped with without post-processing. In the above, if the flat surface is less than 0.05 mm, chipping or scratching is likely to occur. If it exceeds 0.3 mm, the oil scraping ability of the completed ring is reduced.
Note that the width of the flat surface is more preferably in the range of 0.05 to 0.2 mm. The inclination angle of the tapered surface is more preferably in the range of 1.0 to 3.5 °.

[0007] The wire rod of the present invention is intended to prevent the end of the flat surface of the surface to be the outer peripheral surface of the ring from bulging outward during coiling and causing chipping or damage in a subsequent process.
Preferably, the following solution is taken. That is, the surface serving as the outer peripheral surface of the ring includes an end outer protrusion preventing surface for preventing the end from protruding outward during coiling of the wire, and the end outer protrusion preventing surface is the flat surface. And is retracted from the flat surface to the surface that is the inner peripheral surface of the ring (claim 2). It is preferable that the end outside protrusion prevention surface is formed, for example, as an inclined curved surface or an inclined plane.

[0008] In the above, the width of the end outer projection preventing surface is 0.04 mm or less, and the inner side surface of the ring in the range of 0.01 to 0.04 mm from the end of the flat surface. Is preferably in the range of 0.001 to 0.005 mm (claim 3). In addition, the displacement to the surface side which becomes the inner peripheral surface of the ring is 0.002 to 0.005 mm.
Is more preferably within the range.

From the viewpoint of preventing chipping and the like, it is preferable to form a chamfer on at least one of the upper and lower corners formed by the outer peripheral surface of the ring and the upper and lower surfaces of the ring. ). The chamfer is an arc-shaped chamfer (see Fig. 1)
Or a straight chamfer (see FIG. 4). However, in some cases, the chamfer is not formed. In particular, the chamfer at the lower edge of the outer periphery of the pressure ring affects the blow-by amount, so that it is desirable that the chamfer be small.

Since the inclination angle of the tapered surface is as small as 0.5 to 5 °, it is difficult to visually discriminate the upper and lower surfaces of the upper and lower surfaces of the ring. Therefore, the following configuration is preferable. That is, chamfers are formed at upper and lower corners formed by the surface that becomes the outer peripheral surface of the ring and the surfaces that become the upper and lower surfaces of the ring.
The chamfer is formed to be larger than the chamfer on the side which is the lower surface of the ring (claim 5).

In the above, the width of the chamfer on the surface side, which is the lower surface of the ring, in the axial direction after the ring is manufactured is a (mm), and the chamfer on the surface side, which is the upper surface of the ring, is axial after the ring is manufactured. Direction width b (m
m), when the width in the radial direction is c (mm), it is preferable that at least one of b> a + 0.1 mm and c> a + 0.1 mm is satisfied (claim 6).

As described above, by making the upper chamfer less influential on the ring function, the upper and lower surfaces of the wire can be easily distinguished, and confusion between the upper and lower surfaces in the processing step can be prevented. Further, it is possible to prevent a mark for displaying the upper surface from being erroneously displayed on the lower surface. The smaller the chamfer on the lower surface side is, the more effective the oil scraping effect is. for that reason,
The above a is preferably 0.15 mm or less.

In order to make it easy to determine the upper and lower surfaces of a wire,
The following measures can also be taken. That is, a concave groove is formed along the longitudinal direction on the surface that becomes the upper surface of the ring (claim 7). The sectional shape of the concave groove is not particularly limited, and is formed in an arc shape, a rectangular shape, or the like.

In the above, the groove has a width of 0.05.
０．２0.25 mm, the depth is 0.1ｍｍ0.3 mm, and the center in the width direction of the concave groove is located within the range of 0.5 mm from the center in the width direction of the upper surface of the ring. (Claim 8).

FIG. 1 shows a typical example of the cross-sectional shape of a wire rod. In addition, for example, the shapes shown in FIGS. 5 to 7 are used.

As the material of the wire, titanium or aluminum can be used in addition to steel such as valve spring steel, tool steel, and stainless steel.

As a method for producing a wire, a drawing method using a die or a forming method using a roll is used.

The production of the pressure ring of the present invention includes the steps of coiling the above-mentioned wire for a pressure ring, cutting the coiled wire to obtain a ring, performing a surface treatment on the ring, and a surface treatment step. Polishing the upper and lower surfaces of the ring, the outer peripheral surface, and the end face of the abutment before or after the step (Claim 10).

According to the above-described manufacturing method, the tapered surface of the ring outer periphery is either a plastically worked surface during roll forming or die drawing forming, or a surface which has been subjected to surface treatment on the plastically worked surface, and a flat surface is formed by lapping or the like. A pressure ring which is a polished surface or a surface on which a surface treatment has been performed can be obtained. This eliminates the need for polishing the tapered surface, shortens the time required for polishing the flat surface, and provides an inexpensive pressure ring. In addition, as the above-mentioned surface treatment, phosphate film treatment, triiron tetroxide film treatment,
Hard Cr plating, nitriding, PVD or the like is appropriately used.

[0020]

FIG. 1 is a longitudinal sectional view showing an embodiment of a wire rod according to the present invention, FIG. 2 is an enlarged view of a part of FIG. 1, and FIG. 3 is a part of a pressure ring manufactured using the above-mentioned wire rod. FIG.

The wire 1 is made of tool steel and is manufactured by die drawing. The wire 1 has the cross-sectional shape shown in FIG. 1 and has a surface 2 serving as an outer peripheral surface of the ring, a surface 3 serving as an inner peripheral surface of the ring, a surface 4 serving as an upper surface of the ring, and a surface 5 serving as a lower surface of the ring. It is composed of The surface 2, which is the outer peripheral surface of the ring, is formed by a tapered surface 2A, a flat surface 2B, and an end outside projection preventing surface 2C. Tapered surface 2
A is continuous with the flat surface 2B and is inclined toward the surface 3 which is the inner peripheral surface of the ring. The inclination angle of the tapered surface 2A is 2 °.
The width of the flat surface 2A is 0.2 mm. The end outer protrusion prevention surface 2C is a smooth inclined surface continuous with the flat surface 2B,
It is recessed from the flat surface 2B to the surface 3 which is the inner peripheral surface of the ring. The end outer protrusion prevention surface 2C is 0.01 mm from the end of the flat surface 2B, has a displacement of 0.001 toward the surface 3 that becomes the inner peripheral surface of the ring, and 0.04 mm from the end of the flat surface 2B. 0.005mm displacement to the inner surface 3
It is.

Arc-shaped chamfers 6 and 7 are formed at upper and lower corners formed by a surface 2 which is an outer peripheral surface of the ring and surfaces 4 and 5 which are upper and lower surfaces of the ring. The chamfer 6 of the upper corner is formed larger than the chamfer 7 of the lower corner. The width a of the lower chamfer 7 in the axial direction after ring production is 0.15 mm, and the width b of the upper chamfer 6 in the axial direction after ring production is 0.3.
mm, and the width c in the radial direction is 0.3 mm.

A concave groove 8 having an arc-shaped cross section is formed along the longitudinal direction on the surface 4 serving as the upper surface of the ring. The groove 8 has a width of 0.1 mm and a depth of 0.1 mm.
Center in the width direction coincides with the center in the width direction of the surface 4 serving as the upper surface of the ring.

A pressure ring was manufactured using the wire 1 described above. That is, the wire 1 is coiled, and the coiled wire 1 is cut to obtain a ring. Next, the upper and lower surfaces, the outer peripheral surface, and the end face of the abutment are polished. The outer peripheral surface of the ring is polished only for a flat surface. Polishing of the tapered surface is not performed. After polishing, the surface of the ring is subjected to a treatment with triiron tetroxide film. FIG. 3 shows the completed pressure ring 9. Numeral 10 denotes a ferric oxide film.

Next, in the process of manufacturing the pressure ring using the wire for a pressure ring of the present invention, the results of investigating the rate of occurrence of chips and flaws are shown in Table 1. In Table 1, H,
The unit of h, a, b, c, d, and e is mm, and the unit of θ is degree.

As shown in Table 1, when the wire for a pressure ring according to the present invention is used, the rate of occurrence of chips and scratches is reduced as compared with the case where a conventional wire is used. Also,
In the wire rod of the present invention, the upper and lower surfaces can be easily distinguished from each other on the upper and lower surfaces of the ring.

[0027]

[Table 1]

The cross-sectional shape of the wire is not limited to the shape shown in FIG. 1, and for example, the shapes shown in FIGS. FIG. 5 has a tapered cutout surface 11 at the corner between the surface 3 serving as the inner peripheral surface of the ring and the surface 4 serving as the upper surface of the ring (inner cut shape). FIG.
Has a step-shaped notch surface 12 at the end on the side 3 serving as the inner peripheral surface of the ring in the surface 4 serving as the upper surface of the ring (inner cut shape). FIG. 7 has a step-shaped cutout surface 13 at the end on the side 5 serving as the lower surface of the ring in the surface 2 serving as the outer peripheral surface of the ring (undercut shape).

In FIGS. 4 and 5 to 7, the end outer projection preventing surface 2C is a smooth inclined surface continuous with the flat surface 2B, as shown in an enlarged manner in FIG. ,
It is retracted from the flat surface 2B toward the surface 3 which is the inner peripheral surface of the ring.

[0030]

As described above, the wire for a pressure ring according to the present invention can prevent chipping or damage during coiling or polishing. Further, the upper and lower surfaces of the ring can be easily distinguished from the upper and lower surfaces. In addition, an inexpensive and high-performance pressure ring can be manufactured using the pressure ring wire of the present invention.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a wire rod of the present invention.

FIG. 2 is an enlarged view of a part of FIG.

FIG. 3 is a longitudinal sectional view showing a part of a pressure ring manufactured using the wire.

FIG. 4 is a longitudinal sectional view showing another example of chamfering in the wire rod of the present invention.

FIG. 5 is a longitudinal sectional view showing another sectional shape of the wire rod of the present invention.

FIG. 6 is a longitudinal sectional view showing still another sectional shape of the wire rod of the present invention.

FIG. 7 is a longitudinal sectional view showing still another sectional shape of the wire rod of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wire rod 2 The surface which becomes the outer peripheral surface of a ring 2A Tapered surface 2B The flat surface 2C The surface which prevents an end outside projection 3 The surface which becomes the inner peripheral surface of a ring 4 The surface which becomes the upper surface of a ring 5 The surface which becomes the lower surface of a ring 6, 7 chamfering Reference Signs List 8 concave groove 9 pressure ring 10 triiron tetroxide coating 11, 12, 13

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masao Ishida 1-9-9 Yaesu, Chuo-ku, Tokyo Imperial Piston Ring Co., Ltd. F term (reference) 3J044 AA18 BA03 CB04 CB12 DA09 DA16 4E070 AA02 AB10 AC03

Claims (10)

[Claims] 1. A surface serving as an outer peripheral surface of a ring includes: a flat surface;
A tapered surface that is inclined toward the inner peripheral surface of the ring and is continuous with the flat surface, the flat surface has a width of 0.05 to 0.3 mm, and the tapered surface has an inclination. A wire for a pressure ring having an angle of 0.5 to 5 °. 2. A surface serving as an outer peripheral surface of a ring is provided with an end outside projection preventing surface for preventing an end portion from projecting outside during coiling of a wire, and the end outside projection preventing surface is provided with: 2. The wire for a pressure ring according to claim 1, wherein the wire is provided continuously with the flat surface, and is retracted from the flat surface toward a surface which is an inner peripheral surface of the ring. 3. The end outside projection preventing surface has a width of 0.04 mm or less, and is 0.0 mm from an end of the flat surface.
The wire for a pressure ring according to claim 2, wherein a displacement to a surface side serving as an inner peripheral surface of the ring in a range of 1 to 0.04 mm is in a range of 0.001 to 0.005 mm. 4. A chamfer is formed on at least one of upper and lower corners formed by a surface to be an outer peripheral surface of the ring and surfaces to be upper and lower surfaces of the ring. Or the wire for a pressure ring according to 3. 5. A chamfer is formed at upper and lower corners formed by a surface serving as an outer peripheral surface of the ring and surfaces serving as upper and lower surfaces of the ring. The wire for a pressure ring according to claim 1, wherein the wire is formed to be larger than a chamfer on a surface side serving as a lower surface of the ring. 6. A width of a chamfer on a surface side serving as a lower surface of a ring, which is in an axial direction after manufacturing the ring, is a (mm), and a direction in which a chamfer on a surface side serving as an upper surface of the ring is an axial direction after manufacturing the ring. Where b (mm) and c (mm) the width in the radial direction, b> a + 0.1
6. The pressure ring wire according to claim 5, wherein at least one of mm and c> a + 0.1 mm is satisfied. 7. The ring according to claim 1, wherein a concave groove is formed along a longitudinal direction on a surface serving as an upper surface of the ring.
A wire for a pressure ring according to any one of the above. 8. The groove has a width of 0.05 to 0.25 m.
m, the depth is 0.1 to 0.3 mm, and the center in the width direction of the concave groove is located within a range of 0.5 mm from the center in the width direction of the surface serving as the upper surface of the ring. The wire for a pressure ring according to claim 7, characterized in that: 9. A pressure ring having a tapered surface and a flat surface on an outer periphery, wherein the tapered surface is a plastically processed surface or a surface obtained by performing a surface treatment on the plastically processed surface, and the flat surface is a polished surface. A pressure ring characterized by having a surface or a polished surface subjected to a surface treatment. 10. A step of coiling the wire for pressure ring according to claim 1, a step of cutting the coiled wire to obtain a ring, a step of subjecting the ring to a surface treatment, Polishing the upper and lower surfaces, the outer peripheral surface, and the abutment end surface of the ring before or before or after the processing step.