JPH02240456A - Combination oil ring - Google Patents

Abstract

PURPOSE:To prevent abnormally stepped wearing in upper and lower surfaces of an oil ring groove by combining a spacer expander and a side rail fitted to the oil ring groove and providing a slit in an abutment part of the side rail. CONSTITUTION:Two upper and lower side rails 10 are combined with a spacer expander 15, when the rails and the expander are fitted to an oil ring groove 32 of a piston 15, the side rail 10 is pressed by a pad part 16 of the spacer expander 15 and brought into contact with an internal surface of a cylinder 20. Even when an abutment part 12 is pressed by the pad part 16, a slit 13, being provided in the peripheral direction from an end face of the abutment part 12, generates thickness smaller in a radial direction than in the other accordingly even small receiving force, applying a surface pressure to a cylinder internal peripheral surface and a side pressure to oil ring groove upper and lower surfaces 34, 34. The side pressure, being small, prevents the abutment part 12 from abnormally wearing the oil ring groove upper and lower surfaces 34. While the surface pressure of the abutment part 12 is equal to or smaller than the other part, but the abutment part 12, coming into surely contact with the internal peripheral surface of the cylinder 20, almost prevents a seal function from deteriorating.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a combination oil ring consisting of a spacer expander and a side rail that is fitted into an oil ring groove of a piston of an internal combustion engine.

[Prior Art] In recent years, in order to improve the wear resistance of the side rails of combination oil rings, hardening treatments such as full-surface nitriding have been increasingly performed. However, this also increased the aggressiveness of the side rail against the sliding counterpart, especially the upper and lower surfaces of the piston ring groove. During operation of the internal combustion engine, if the butt part of the spacer expander is located on the inner circumferential side of the abutment of the side rail, the surface pressure of the abutment against the cylinder increases as shown in Figure 5, and based on this, the oil ring The lateral pressure on the upper and lower surfaces of the groove also increases. As a result, the first abutment part slides under strong pressure on the upper and lower surfaces of the oil ring groove, so regardless of the fuel used (unleaded gasoline, LPG, diesel oil), as shown in Figures 6 and 7, the upper and lower surfaces of the oil ring groove Abnormal stepped wear in the circumferential direction occurs. When this abnormal wear occurs, oil escapes from there, which not only increases oil consumption, but also obstructs the circumferential movement of the oil ring, which increases the number of vertical scratches on the cylinder.

In order to solve this problem, Utility Model Application No. 60-102446 and Utility Model Application No. 63-34343 cut out the inner periphery of the abutment of the side rail, and installed a spacer expander located on the inner periphery of the abutment. It is proposed to prevent an increase in surface pressure at the abutment area due to the butt part.

[Problems to be Solved by the Invention] In the side rail proposed above, when the butt part of the spacer expander is accommodated in the cutout on the inner peripheral side of the abutment, there is almost no relative movement between the side rail and the spacer expander. There was a problem in that the inner circumferential surface portion of the side rail that was in contact with the oil ring was fixed, and abnormal wear occurred in that portion, reducing the function of the oil ring.

The present invention has been made in view of the above, and its purpose is to eliminate abnormal steps on the upper and lower surfaces of the oil ring groove due to the side rail joints without restricting the relative movement between the side rail and spacer expander of the combined oil ring. The purpose is to prevent sticking and wear.

[Means for Solving the Problems] In order to achieve the above object, the means adopted by the present invention is to provide a combination oil ring consisting of a spacer expander and a side rail, as shown in the embodiment of FIG. This is because a slit 13 extending in the circumferential direction from the end face is provided in the abutment part 12 of the IO. The amount of cutting to form the slit 13 is set so that the contact pressure at the abutment part is the same as or smaller than the contact pressure at other parts, but the position T of the distance from the inner circumference to the slit on the end face is 1/3 to 2/3 of the radial thickness of the side rail (surin)
It is desirable that the radial width X of 13 is 50p or more, and the circumferential length Y of 13 is 1111T.
It is desirable to set this in correlation with

[Operation] When the combined oil ring is fitted into the oil ring groove of the piston, the side rail is stretched by the spacer expander and comes into pressure contact with the inner peripheral surface of the cylinder. As shown in FIG. 5, in the conventional oil ring, the surface pressure at the abutment part is maximum, but as shown in FIG. Therefore, the lateral pressure of the abutment part pushing the upper and lower surfaces of the oil ring groove is also equal to or smaller than the lateral pressure of other parts, so the side rail is Even if the abutment and the upper and lower surfaces of the oil ring groove slide,
Abnormal stepped wear does not occur on the upper and lower surfaces of the oil ring groove.

Furthermore, as the surface pressure on the cylinder at the side rail abutment and the lateral pressure on the upper and lower surfaces of the oil ring groove decrease, not only does the frictional resistance between the inner circumferential surface of the cylinder and the upper and lower surfaces of the oil ring groove against the rotational movement of the side rail decrease, but also the spacer Since the frictional resistance with the butt portion of the expander is also reduced, the side rail can rotate freely relative to the spacer expander during operation of the internal combustion engine.

[Example] The oil ring of the present invention will be explained based on an example shown in the drawings.

As shown in FIGS. 2 and 3, a slit 13 is provided in the abutment portion 12 of the side rail 10, extending in the circumferential direction from the end surface thereof. 3 and 1 measured from the inner circumference of the side rail
The distance T to 3 is 1 of the radial thickness of the side rail 10.
73 to 2/3, and the radial width X of the slit 13 is preferably 50 uL or more.Also, the length Y extending in the circumferential direction from the end surface of the slit 13 is related to the distance 1, but the spacer extract The pitch is set to be greater than the pitch of the bat portion te of the panda 15. The slitting of the side rail abutment is not performed after the side rail is machined into a perfect circle, but after winding and cutting the steel ribbon, and after the slitting, the abutment is machined into a perfect circle. During use, the inner diameter of the end of the side rail is larger at the abutment part than at other parts, and the ends of the slits 13 on both sides are in contact with each other.

Two upper and lower side rails 10 and spacer expander 1
5 are combined and fitted into the oil ring groove 32 of the piston 30, the side rail 10 is attached to the spacer expander 15.
The abutment part 12 is pressed by the butt part 16 and comes into contact with the inner circumferential surface of the cylinder 20, but the abutment part 12 is not directly pressed by the butt part IB, or
Even if it is pushed, since the radial thickness is smaller than other parts, the force received from the butt part 12 is small, and surface pressure is applied to the inner peripheral surface of the cylinder, and lateral pressure is applied to the lower surface of the oil rift groove.

However, since the lateral pressure is small, the abutment part 12 will not abnormally wear the upper and lower surfaces 34 of the oil ring groove.0 The abutment part 12 has a contact pressure that is the same as or smaller than that of other parts, but the cylinder Since the inner circumferential surface of 20 is securely contacted, it can be said that there is almost no deterioration in the sealing function.

Even if the inner circumferential side of the abutment part 12 contacts the butt part 16, the contact pressure is small, and the outer circumferential side contacts the inner circumferential surface of the cylinder 20 with a small surface pressure, so that the wear resistance against movement of the side rail IO in the circumferential direction is also small. , the side rail lO rotates smoothly not only with respect to the oil ring groove 32 but also with respect to the spacer expander 15 inside the oil ring vII32.

Since the inner circumferential side of the side rail 10 is uniformly smooth and does not restrict the pad portion 16 of the spacer expander 15 at all, the relative movement between the side rail and the spacer expander is restricted and abnormal wear of both is prevented. do not have.

Next, a comparative test conducted to confirm the effects of the combination oil ring of the present invention will be described. Outer diameter 85
An example of the present invention was one in which a slit was provided at the abutment of a side rail having a thickness of 2.65 mm in the radial direction, and a conventional example was one in which no slit was provided. The distance from the inner circumference of the slit on the end face is 1/3 of the radial thickness of the side rail, and the radial @X of the slit is 0.
The length Y extending in the circumferential direction from the end surface is 8 mm. When the contact pressure of the example and the conventional example was measured, the contact pressure of the abutment part of the conventional one was 2.0Kg/mm'', but the contact pressure of the abutment part of the example was 1.5Kg/mm''. m m
'Met. As described above, it was confirmed that the surface pressure of the abutment portion of the example was approximately 25% lower than that of the conventional example.

Although a combination oil ring consisting of a spacer expander and two side rails placed above and below the spacer expander is shown as an example, the present invention provides a combination oil ring consisting of a spacer expander and one side rail placed above it. It goes without saying that the scales can also be applied to rings.The slits in the embodiment extend linearly with the same width from the end face of the side rail, but the slits may extend from the end face in a curved manner, for example, in an arc shape. Further, the width of the slit is not the same, and may be reduced or enlarged as it extends.

[Effects of the Invention] As mentioned above, since the combination oil ring of the present invention has a slit extending circumferentially from the end face at the abutment of the side rail, the abutment can be applied to the inner circumference of the cylinder with relatively small surface pressure and side pressure. surface and the upper and lower surfaces of the oil ring groove, respectively. Therefore, even if the side rail abutment and the upper and lower surfaces of the oil ring groove slide in the circumferential direction, the upper and lower surfaces of the oil ring groove will not experience abnormal stepped wear, and the side rail abutment will not break. The excellent effect of reducing lubricant consumption during operation can be obtained.

Further, since the side rail abutment portion contacts the inner peripheral surface of the cylinder and the upper and lower surfaces of the oil ring groove with a relatively small surface pressure, the rotational movement of the side rail accompanying the reciprocating movement of the piston is made extremely smooth. by this.

Since the combination oil ring quickly adapts to the oil ring groove, it also has the special effect of reducing initial lubricating oil consumption.

Furthermore, the inner periphery of the side rail in contact with the butt part of the spacer expander is smooth and the two move relative to each other without being restrained, so the contact area between the pad part and the inner periphery of the side rail will not wear out abnormally. The function of the oil ring will not be deteriorated.

[Brief explanation of drawings]

FIG. 1 is an enlarged plan view of a side rail abutment used in the combination oil ring of the present invention, FIG. 2 is an enlarged plan view of essential parts of an embodiment of the combination oil ring of the present invention, and FIG. An enlarged sectional view taken along the line m-■ in the figure, Figure 4 is the side rail surface pressure distribution diagram of Figure 1, Figure 5 is the side rail surface pressure distribution diagram of the conventional side rail, Figures 6 and 7 are the piston. FIG. 6 is an enlarged front view and a plan view showing abnormal stepped wear in the oil ring groove. In the figure, numeral 10 is a side rail, 12 is an abutment,
13 is a slit, 15 is a spacer expander, 16 is a pad portion, 20 is a cylinder, 30 is a piston, 32 is an oil ring groove, and 34 is an upper and lower surface of the oil ring groove. Applicant Nippon Piston Ring Co., Ltd. Agent Hajime Kawakami (1 other person) Figure 1 3 Figure 7

Claims (1)

[Claims] 1) A combination oil ring consisting of a spacer expander and a side rail fitted into an oil ring groove of a piston, characterized in that a slit extending circumferentially from the end surface is provided at the abutment part of the side rail. Combination oil ring.