JPH05332451A - Side rail for combination oil ring and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide the side rail for combination oil ring, of which abrasion resistance is improved and of which attacking property to a piston is reduced to eliminate the generation of groove abrasion phenomenon of a piston ring groove and which can prevent the abnormal abrasion of the piston ring and the lowering of function of lubricating oil consumption quantity therewith, and the manufacture for obtaining the side rail having these advantages efficiently. CONSTITUTION:A side rail for combination oil ring has an ionitride layer 1 only on the contact surface with the inner surface of a cylinder and the contact surface with a spacer expander. In the case where an annular side rail base material 2 for combination oil ring has an abutment port part 10, the side rail is held under the condition that the abutment port part 10 is closed, and in the case where a spiral side rail base material for combination oil ring is used, the side rail is held under the contracted condition, and ionitriding is applied to the surface of the side rail for combination oil ring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side rail for a combined oil ring and a method for manufacturing the same, and more particularly to a piston formed on a piston which is excellent in wear resistance and has a reduced attack on the piston. A side rail for a combined oil ring that does not roughen the ring groove, and therefore prevents abnormal wear of the piston ring groove and accompanying functional deterioration of the amount of lubricating oil consumed, and manufacturing that enables efficient production of this side rail for a combined oil ring. With respect to the method.

[0002]

2. Description of the Related Art A combined oil ring is widely used as a piston ring mounted on a piston constituting an automobile engine, particularly a four-cycle engine.

As shown in FIG. 5, this combined oil ring comprises a spacer expander 100 and a pair of side rails 101a and 101b.
Spacers a and 101b are separated by the spacer expander 100 in the axial direction of the piston 110 and are pressed and urged toward the cylinder inner peripheral surface 120.

By the way, in the combined oil ring having such a structure, the wear resistance of the sliding surface is required to be improved with the recent increase in the output and rotation of the automobile engine. For example, as shown in FIG. 6, for example, a combined oil ring using a side rail in which a nitride layer 102 is formed on the entire peripheral surface of a base material 101 is known. And the side rail with such a configuration,
For example, it is manufactured by adopting a gas nitriding method, a salt bath nitriding method or the like to form a nitride layer on the entire peripheral surface of the base material.

[0005]

However, the combined oil ring constituted by using the conventional side rail having the nitrided layer on the entire peripheral surface of the base material has the following problems.

That is, when the side rail has a nitrided layer on the entire peripheral surface of the base material, such side rail is combined with the spacer expander and mounted in the piston ring groove formed in the piston, The wear resistance of the contact surface with the spacer expander (inner peripheral surface of the side rail) and the contact surface with the inner peripheral surface of the cylinder (outer peripheral surface of the side rail) is significantly improved when actually sliding in the cylinder. However, the hardness of the upper and lower surfaces of the side rails that come into contact with the piston will be increased more than necessary, and as a result, the aggression of the side rails against the piston will be increased carelessly and the piston ring groove will be roughened. There was a problem that it would end up. When the piston ring groove is roughened, there is an adverse effect that abnormal wear of the piston ring groove and increase of lubricating oil consumption are caused.

The present invention has been made under such circumstances, and an object of the present invention is to improve wear resistance and not to cause so-called groove roughening phenomenon of the piston ring groove, and therefore the piston ring. It is an object of the present invention to provide a side rail for a combined oil ring that prevents abnormal wear of a groove and a functional decrease in the amount of lubricating oil consumed accompanying it, and a manufacturing method capable of efficiently obtaining a side rail having such advantages.

[0008]

The structure of the present invention for achieving the above-mentioned object is to form an oil ring in combination with a spacer expander and to separate the piston ring by the spacer expander in the sliding direction. In addition, in the side rail for a combined oil ring that is pressed and urged against the inner peripheral surface of the cylinder, the combined oil has an ion nitriding layer only on the contact surface with the inner peripheral surface of the cylinder and the contact surface with the spacer expander. In the method of manufacturing a side rail for a combined oil ring, which is a side rail for a ring and is subjected to an ion nitriding treatment on the side rail base material for a combined oil ring, Hold the mouth closed and then attach to the side rail base material for the combined oil ring. The side rail base material for the combined oil ring is a method for manufacturing the side rail for the combined oil ring, characterized in that the ion nitriding treatment is performed only on the contact surface with the cylinder inner peripheral surface and the contact surface with the spacer expander. In a method of manufacturing a side rail for a combined oil ring for forming an ion nitride layer, an ion nitriding treatment is performed on the outer peripheral surface and the inner peripheral surface of a spiral side rail for a combined oil ring base material, and then the side surface for the combined oil ring. For a combination oil ring, which is characterized in that the rail base material is cut at predetermined intervals to form a side rail base material for a combined oil ring, and a mating portion is formed at an end of the side rail base material for the combined oil ring. It is a manufacturing method of a side rail.

[0009]

According to the above construction, the contact surface with the spacer expander (the inner peripheral surface of the side rail) and the contact surface with the inner peripheral surface of the cylinder (the outer periphery of the side rail) are required to have excellent wear resistance. The ion nitride layer is formed only on the surface. As a result, the abrasion resistance of the side rails against sliding is significantly improved as compared with the case where the ion nitride layer is not formed. On the other hand, in this side rail, an ion nitriding layer is formed on the surface that comes into contact with the piston when it is mounted in the piston ring groove formed on the piston in combination with the spacer expander, that is, on the upper surface and the lower surface of the side rail. Not formed. Therefore, the aggression of the side rails against the piston does not inadvertently increase. As a result, in the piston ring groove formed in the piston, occurrence of so-called groove roughening phenomenon due to contact with the side rail is prevented. Therefore, it is possible to prevent the occurrence of adverse effects such as abnormal wear of the piston ring groove and an increase in the amount of lubricating oil consumed due to the occurrence of the groove roughening phenomenon.

Further, in such a side rail, when the abutment portion is formed on the annular side rail base material for the combined oil ring, the abutment portion is held in a closed state, and then, It is efficiently manufactured by performing ion nitriding treatment only on the contact surface (outer peripheral surface) with the cylinder inner peripheral surface and the contact surface (inner peripheral surface) with the spacer expander in the side rail base material for the combined oil ring.

Further, such a side rail uses a side rail base material for a spiral combination oil ring,
Ion nitriding treatment is performed on the outer peripheral surface and the inner peripheral surface of the spiral side rail base material for the combined oil ring, and then the side rail base material for the combined oil ring is cut at predetermined intervals to form the combined oil ring. It can be manufactured efficiently by using the side rail base material and forming the abutment portion at the end of each side rail base material for the combined oil ring.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the side rail for the combined oil ring is provided with the ion nitride layer 1 only on the contact surface with the spacer expander (inner peripheral surface) and the contact surface with the cylinder inner wall (outer peripheral surface). It is a thing.

The side rail base material 2 for a combined oil ring in which the ion nitride layer 1 is formed only on the inner peripheral surface and the outer peripheral surface in this manner is made of martensitic stainless steel.

The ion nitride layer 1 provided on the outer peripheral surface and the inner peripheral surface of the side rail base material 2 for a combined oil ring made of such a material is usually formed by performing an ion nitriding treatment.

Here, the ion nitriding treatment means low pressure H ₂ ,
300-1200V with the furnace wall as the anode and the side rail base material 2 for the combined oil ring as the cathode in the N ₂ gas atmosphere
The ionized N is accelerated and collides with the cathode, and the side rail base material 2 for the combined oil ring is heated and N penetrates into the side for the combined oil ring. The nitride layer 1 is formed on the surface of the rail base material 2.

Specifically, as shown in FIG. 2, when the side rail base material 2 for the combined oil ring has the abutment portion 10, the abutment portion 10 is closed. In addition, several side rail base materials 2 for combined oil rings are bundled and held by, for example, a work clamp in a state where both side surfaces (upper surface and lower surface) where the ion nitride layer 1 does not need to be formed are stacked, and in that state A plurality of side rail base materials 2 for combined oil rings are put in a furnace and subjected to ion nitriding treatment to form an inner peripheral surface of each side rail base material 2 for combined oil rings (a spacer when mounted in a piston ring groove). The ion nitride layer 1 is formed on the surface that contacts the expander) and the outer peripheral surface (the surface that contacts the cylinder inner peripheral surface when mounted in the piston ring groove).

The side rail for the combined oil ring having the ion nitride layer 1 only on the inner and outer peripheral surfaces is
For example, as shown in FIG. 3, a spiral combination side rail base material 3 for an oil ring is used, and the side rail base material 3 for a combined oil ring is held in a contracted state by, for example, a work clamp, and as it is inside the furnace. The inner peripheral surface (the surface that comes into contact with the spacer expander when mounted in the piston ring groove) and the outer peripheral surface (piston An ion nitriding layer is formed on the surface which comes into contact with the inner peripheral surface of the cylinder when it is mounted in the ring groove, and then the side rail base material 3 for the combined oil ring is cut at predetermined intervals to form the combined oil ring. It is also efficient to use the side rail base material 2 and form the mating portion 10 at the end of each side rail base material 2 for the combined oil ring. It can be produced.

Next, a combination oil ring formed by using the side rail for combination oil ring of the present invention and a combination oil ring formed by using the conventional side rail for combination oil ring in which a nitride layer is formed on the entire circumferential surface. about,
Compare in detail. Experimental Example 1 A plurality of side rail base materials 2 for combined oil rings, which are made of martensitic stainless steel and have an abutment portion formed at an end thereof, are attached to both side surfaces with the respective abutment portions closed. The stacked and bundled state is held by a work clamp, put into the furnace as it is, and subjected to ion nitriding treatment to form the ion nitride layer 1 only on the inner and outer peripheral surfaces of the side rail base material 2 for each combined oil ring. , A plurality of side rails for combined oil rings were created.

The side rail for a combined oil ring obtained as described above is combined with a spacer expander made of stainless steel and having a nitride layer formed on the entire peripheral surface to form a combined oil ring. Was mounted in the piston ring groove of each piston constituting a 4-cylinder gasoline engine, and an actual machine test was performed to evaluate whether or not a so-called groove roughening phenomenon occurred in the piston ring groove. The results are shown in Table 1.

The actual machine test was conducted under the following conditions. Actual machine test conditions -Internal combustion engine: displacement 2000cc, 4-cylinder gasoline engine-Durability condition: Full / 6000r.pm-Operating time: 200 hours

[0021]

[Table 1] Experimental Example 2 In Experimental Example 1, instead of the side rail for the combined oil ring having the ion nitride layer 1 only on the inner peripheral surface and the outer peripheral surface, the conventional side rail for the combined oil ring having the nitrided layer on the entire peripheral surface is used. Other than that, a combined oil ring was prepared in the same manner as in Experimental Example 1, and an actual machine test was performed on this combined oil ring in the same manner as in Example 1. The results are shown in Table 1. Experimental Example 3 The same actual machine test as in Experimental Example 1 was conducted, and the results of the lubricating oil consumption measured before and after the above-mentioned durability are shown in FIG. 4 as the evaluation of the lubricating oil consumption. Experimental Example 4 The same actual machine test as in Experimental Example 2 was performed, and the results of the lubricating oil consumption measured before and after the above durability as the evaluation of the lubricating oil consumption are shown in FIG. Examination of Results As is apparent from Table 1, in Experimental Example 1, no so-called groove roughness was observed in the piston ring groove in each piston, whereas in Experimental Example 2, the piston of three pistons out of four pistons So-called groove roughness occurred in the ring groove.

Further, as is clear from FIG.
No deterioration was observed before and after the endurance test, whereas in Experimental Example 4, an increase in the lubricating oil consumption was observed before and after the endurance test. From these results, the side rail for the combined oil ring of the present invention does not cause so-called groove roughness in the piston ring groove formed in the piston and does not cause an increase in the amount of lubricating oil consumed. confirmed.

[0023]

EFFECTS OF THE INVENTION According to the present invention, since it has the above-mentioned structure, it is excellent in wear resistance and reduces the aggressiveness to the piston, and so-called groove roughness is formed in the piston ring groove formed in the piston. It is possible to provide a side rail for a combined oil ring that does not cause abnormal wear of the piston ring groove and thus does not cause an increase in the amount of lubricating oil consumed with it.
It is possible to provide a method for manufacturing a side rail for a combined oil ring, which can efficiently obtain a side rail for a combined oil ring having such advantages.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a side rail for a combined oil ring of the present invention.

FIG. 2 is a plan view showing an embodiment of a side rail for a combined oil ring of the present invention.

FIG. 3 is an explanatory view showing a state in which a spiral side rail base material for a combined oil ring that may be used in the method for manufacturing a side rail for a combined oil ring of the present invention is held in a contracted state.

FIG. 4 is a graph showing the relationship between the amount of lubricating oil consumed before and after the endurance when an actual machine test was performed on each of the side rail for combined oil ring of the present invention and the conventional side rail for combined oil ring.

FIG. 5 is a cross-sectional explanatory view showing an example of a mounted state of a combined oil ring.

FIG. 6 is an explanatory sectional view showing a conventional example of a side rail for a combined oil ring.

[Explanation of symbols]

 1 ... Ion nitriding layer 2 ... Side rail base material for combined oil ring 3 ... Side rail base material for combined oil ring

Claims (3)

[Claims] 1. A side rail for a combined oil ring, which is combined with a spacer expander to form an oil ring, which is separated by the spacer expander in a sliding direction of a piston and is biased by an inner peripheral surface of a cylinder. 2. A side rail for a combined oil ring according to, wherein an ion nitriding layer is provided only on the contact surface with the inner peripheral surface of the cylinder and the contact surface with the spacer expander. 2. A method for manufacturing a side rail for a combined oil ring, which comprises subjecting a side rail base material for a combined oil ring to an ion nitriding treatment, wherein an annular side rail base material for a combined oil ring having a mating portion is used. Is maintained in a closed state, and then ion nitriding is performed only on the contact surface with the cylinder inner peripheral surface and the contact surface with the spacer expander of the side rail base material for the combined oil ring. Manufacturing method of side rails for rings. 3. A method of manufacturing a side rail for a combined oil ring, wherein an ion nitriding layer is formed on a side rail base material for a combined oil ring, wherein an outer peripheral surface and an inner peripheral surface of a spiral side rail base material for the combined oil ring are formed. Then, the side rail base material for the combined oil ring is cut at a predetermined interval to form a side rail base material for the combined oil ring, which is further fitted to the end of the side rail base material for the combined oil ring. A method for manufacturing a side rail for a combined oil ring, characterized by forming a mouth portion.