JPS5865369A - Manufacture of one-side keystone type piston ring having streaks on outer peripheral surface - Google Patents

Abstract

PURPOSE:To form uniform streaks on the outer pheripheral surface of a piston ring, by at first forming a slit on the annular ring having a rectangular cross- section, then forming said streaks on side surface simultaneously with tilting said surface so that its diameter decreases downward, subsequently forming a slant surface along the inner peripheral edge of the ring. CONSTITUTION:The outer and the inner peripheral surfaces 1a and 1b of the annular ring 1 having a rectangular cross-section are worked, and a part of the annular ring 1 is cut to form a slit. When a number of minute streaks are formed on the outer peripheral surface 1a, working is performed by slightly tilting the outer peripheral surface 1a simultaneously so that the diameter of the ring is reduced downward. Then, an slant surace 3 is formed on the inner peripheral edge part of the upper surface of the annular ring 1. As a result of this, the outer peripheral surface 1a is twisted, and the outer peripheral surface 1a of the annular ring 1 is formed into cylindrical form. Lastly, the surface of the annular ring 1 including the outer peripheral surface 1a is wrapping-processed, and the one-side keystone type piston ring having streaks on the outer peripheral surface is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides a piston ring that is fitted into a groove formed on the outer circumferential surface of the piston and slides against the inner circumferential surface of the cylinder as the piston moves. The present invention relates to a method for manufacturing a single-sided keystone type screw F ring having a slope (1) on the inner peripheral edge of the upper surface of the ring.

The space between the outer peripheral surface of the piston and the inner peripheral surface of the cylinder cannot be made completely airtight, and a small gap exists.

Prevent the pressure inside the combustion chamber from escaping outside through this gap.
In order to do this, a groove is formed on the outer circumferential surface of the piston over the entire circumference, and a screw ring is fitted into this groove, and the outer peripheral edge of the screw ring is elastically protruded out of the groove to open the cylinder. The piston is in sliding contact with the inner circumferential surface of the piston to maintain airtightness between the inner circumferential surface of the cylinder and the outer circumferential surface of the piston.

By the way, the outer circumferential surface of such a piston ring comes into sliding contact with the inner circumferential surface of the cylinder at high speed when the internal combustion engine is operating, so if there is no oil film on the contact surface, scuffing will occur on the inner circumferential surface of the cylinder. . In order to prevent the occurrence of this scuffing, the piston ring (2) has many minute scratches formed on the outer circumferential surface of the piston ring that comes into contact with the inner circumferential surface of the cylinder, and the piston ring (2) retains the lubricating oil within these scratches. Among such screw F rings having striations on the outer peripheral surface, a single-sided keystone-shaped screw ring having an inclined surface formed only on the inner peripheral edge of the upper surface was manufactured in a conventional manner.

That is, as shown in FIGS. 1 and 2, first, a ring 1 having a rectangular cross section is made, and the outer circumferential surface 11 of this ring l is cam-processed, and then the inner circumferential surface 1. Process b. Next, as shown in No. 3111J, a large number of minute scratches are formed on the outer circumferential surface l& of the ring l, where a part of the ring l is cut to form the abutment 2.

An inclined surface 3 is formed on the inner peripheral edge of the upper surface of the ring 1, and then the surface of the ring 1 including the outer peripheral surface is subjected to a lapping treatment to form a piston ring.

However, the single-sided kissin-type screw-on ring which is formed by the above-mentioned process and has striations on its outer circumferential surface has the following disadvantages.

That is, when the slope 3 is formed on one side of the outer circumferential surface 1& of the ring l after forming the grooves, the entire ring l is distorted by one strain, and the outer circumferential surface 11L also becomes #! As shown exaggerated in Figure 5,
The outer diameter becomes smaller towards the top 3) <It is slightly inclined as shown. When the final lapping process is performed with the outer circumferential surface la tilted in this way, the lower culm of the outer circumferential surface 1a is shaved off longer, and as a result, the depth of the striations 4 increases from top to bottom as shown in Figure 6. In some cases, it gradually leaks towards the end, and there are no streaks at the bottom end.

As described above, if the depths of the striations are uneven, or if the striations are partially absent, the oil retaining effect of the striations will be insufficient, and prevention of scuffing will be incomplete.

The present invention aims to provide a method for manufacturing a single-sided keystone type piston ring having striations on the outer circumferential surface, which does not cause such unevenness of striations and can completely prevent the occurrence of scuffing.

Below is the manufacturing method of the present invention! 12 dawn.

In the manufacturing method of the present invention, first, as shown in FIGS. 1 and 2, a ring l having a rectangular cross section is made, and after processing the outer circumferential surface 1& and inner circumferential surface 1b of this circle Ill, As shown in the third factor, a part of the circle TR1 is cut (4) to form an opening 2. Next, a large number of fine scratches are formed on the outer circumferential surface l&, but at the same time, the outer lit W
As shown in FIG. 7, the a s a is machined so as to be slightly inclined so that the diameter decreases downward. This outer peripheral surface 1. After the taper processing step and the striation processing step a are completed, an inclined surface (FIGS. 4 and 5) 3 is formed in the WRI 1 portion within the upper surface of the circle 1lIl. When this inclined surface 3 is formed,
The entire circle Ill generates a strain in which the outer circumferential surface 1a is twisted and inclined upward so that the outer circumferential surface 1a has a small diameter C;
Since the surface is tilted downward in advance so that it has a small diameter, the outer circumferential surface is not sloped as shown in Figure 4.
Nl is applied in a cylindrical shape. After forming the inclined surface 3, the surface of the ring l including the outer circumferential surface l& is subjected to lapping treatment to complete a single-sided keystone type piston ring having striations on the outer circumferential surface. During this lapping process, since the outer circumferential surface l& of the circle l1111 is formed into a cylindrical shape without inclination, the surface portion (5) is scraped off uniformly over the entire surface of the outer circumferential surface la. As shown in FIG. 8, the depth of 4 is substantially uniform over the entire outer circumferential surface 1;

In addition, when forming the inclined surface 3 only on one side of the circle 'g41, the angle at which the outer circumferential surface 1m is inclined due to the distortion of the ring 1 is the outer diameter 47-1 width 2. In the case of a screw ring with an o-1 thickness of 1.9 m and an abutment gap of 0.25 m5, the gap is 9 for the abutment.
9' at 0° position, 180'' to joint φ port - position f5'
It is appropriate to set the angle number 25' to 40' so that the outer circumferential surface is inclined in the opposite direction at the same time as the groove is processed. If this inverted bond slope angle is less than 5', the angle is too small and it is not possible to cancel out the distortion during machining of the inclined surface 3. On the other hand, if it is more than 40', the angle is too large and the This is because the streaks on the upper side of the outer peripheral surface disappear after the lapping process 11.

According to the method of manufacturing a single-sided keystone piston ring having striations on the outer peripheral surface of the present invention, uniform striations can be formed on the outer peripheral surface (6) as described above. The piston ring q has an excellent oil retaining effect and can effectively prevent scuffing.

[Brief explanation of the drawing]

1st~. Figure 4 shows the manufacturing process of a single-sided keystone type piston rig. Figure 1 is a single-sided view of the ring body, and Figure 2 is an enlarged AA cross-sectional view of Figure 1, group 3v! J is a plan view of the annular body forming the abutment, No. 4 is a cross-sectional view similar to Fig. 2 showing the cross section of the piston ring with keystone processing, and Fig. 5 shows the state of distortion of the outer circumferential surface due to Keith F〉 processing. Cross section, city 6
The figure shows an enlarged longitudinal section of the outer circumferential surface of a piston ring manufactured by the conventional method. Definitely! ! 1, FIG. 8 is an enlarged vertical cross-sectional view of the outer surface of a shilling manufactured by Akira Honda's method. l: circular ring, 1m: outer peripheral surface, 1b + inner peripheral surface, 2: abutment,
3: Inclined surface, 4: Streak. ()) Figure 1 Figure 182 3rdrI! J ""

Claims (1)

[Claims] The outer peripheral surface (la) and the inner peripheral surface (1b) of a ring (1) with a rectangular cross section
) and then cut a part to form an abutment (2), and then the outer circumferential surface, (la) l, and a large number of fine scratches (4).
After forming a circular ring (1) and slightly tilting the outer circumferential surface (la) upward so that the diameter becomes smaller, a circular ring (1) is formed.
A method for producing a single-sided keystone piston ring having striations on the outer circumferential surface, which comprises forming an inclined surface (3) on the inner peripheral edge of the upper surface, and then lapping the surface of the ring (1) including the outer circumferential surface (1&). .