JPS61282670A - Spacer expander for assembled piston ring - Google Patents

Abstract

PURPOSE:To provide a stable surface pressure for a side rail by forming an inner peripheral bent part having an inclined surface for pressing the inner periphery of the side rail, outer peripheral shelf part for loading the side rail and slits onto a band plate. CONSTITUTION:A space expander 12 has an inner peripheral bent part 13 as the inclined surface 14 obtained by bending the upper and lower parts of the spherical side edge of a band plate towards the inner peripheral side. Further, a supporting part 16 for supporting the upper and lower inner peripheral bent parts is provided. Further, the outer peripheral shelf part 18 which is formed by cutting the supporting part 16 at a certain intervals from the center part in the circumferential direction and vertically erecting the cut parts is provided. Though the inclined surface 14 of the inner peripheral bent part 13 contacts with the circumference of a side rail 26 and performs pressing in the vertical direction and the outer circumferential direction, a uniform surface pressure can be provided over the whole periphery, since the inner peripheral bent part 13 exists except in the little part of the slits 20 and 22.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a spacer expander for a combination piston ring used for flIW4 oil control in a reciprocating internal combustion engine. This invention relates to a spacer-expander for placing two side rails and pressing them in the outer circumferential direction and the upper and lower surfaces of a ring groove.

<Prior Art> As a spacer expander for a piston ring, there is a spacer expander that has a flat shelf portion partially bent and erected toward the outer periphery. It is disclosed in. By plane-supporting the upper and lower side rails by the flat shelf portion, they provide stable blood pressure over the entire circumference of the upper and lower surfaces of the side rails, and therefore have excellent sealing performance on the upper and lower surfaces of the ring groove.

<Problems to be Solved by the Invention> However, in the above-mentioned conventional device, the part that contacts the inner circumference of the side rail is cut out by about 50% of the entire circumference, which makes it difficult to connect the side rail to the cylinder wall. The surface pressure applied toward the surface was not uniform over the entire circumference, and therefore the oil scraping effect was insufficient.

Therefore, an object of the present invention is to solve the above-mentioned problems and provide a spacer expander that can provide stable blood pressure to the side rail both in the vertical direction (piston axial direction) and in the outer circumferential direction. .

<Means for Solving the Problems> In order to achieve this object, the spacer expander of the present invention presses the inner periphery of the side rail, which is formed by bending the upper and lower sides of the strip plate toward the inner periphery. an inner circumferential bending part having an inclined surface for the purpose of bending, a supporting part that connects and supports the upper and lower inner circumferential bending parts, which is made up of the central part of the strip plate; By cutting it off and opening both sides toward the outer circumference, and standing upright on the outer circumferential side at the upper and lower edges of the support part, the outer shelf section is used for placing side rails. It is composed of slits cut in alternating symmetrical patterns and slits cut out in the radial direction of the inner circumferential bent portion above and below the outer circumferential shelf.

Preferably, the inner circumferential bent portion includes a flat portion bent at right angles to the inner circumferential side behind the inclined surface, and the central portion of the supporting portion is The vertical width of the spacer expander is changed by bending the spacer expander toward the outer circumference or the inner circumference along the circumferential direction.

<Function and Examples> The first to fourth embodiments and their operations will be described with reference to the drawings.

A first embodiment is shown in FIGS. 1-3. That is, as shown in the partial perspective view of FIG. 1, the spacer expander 12
Bend the top and bottom of both side edges of the strip plate toward the inner periphery to form the inclined surface 1.
4, the inner circumferential bent portion 13.13, and the upper and lower inner circumferential bent portions 1
3. A supporting part 16 that is located between 13 and connected to support them, and a supporting part 1 that is separated from the center part at regular intervals in the circumferential direction and opened on both sides toward the outer periphery.
Peripheral shelf section 18.18, erected at right angles at the upper and lower edges of 6.
...has... In addition, in order to bend the spacer expander 12 in an annular shape, adjacent outer peripheral shelf portions 18, 18
The inner circumferential bent portion 1 is alternately symmetrical and perpendicular to the circumferential direction between
3, a slit 20.20 cut to a depth of about 2/3 of the support part 16, and a slit 20.20, which is cut to a depth of about 2/3 of the support part 16, and a slit 20.20, which is cut into the inner peripheral bent part 13 at the top and bottom of the outer peripheral shelf part 18 in the radial direction (direction perpendicular to the circumferential direction). There are slits 22, 22, . . . Furthermore, windows 24 are naturally formed by erecting the outer peripheral shelf 18, and these windows function as oil discharge ports.

Although not shown, the spacer expander 12 having such a configuration is formed in an annular shape as a whole,
Like a normal piston ring, it has a seam portion separated at one location of the bearing portion 16.

FIG. 2 shows a side rail 26 placed on the outer periphery shelf 18 of the spacer expander 12 shown in FIG.
There is a cross-sectional view showing the state in which it slides. The inclined surface 14 of the inner periphery bending part 13 contacts the inner periphery of the side rail 26 and presses it in the vertical direction and the outer periphery direction, but since the inner periphery bending part 13 exists except for a small part of the slit 20. It can provide uniform blood pressure all around the circumference.

Since the upper and lower outer peripheral shelves 18 provide planar support for the upper and lower surfaces of the side rails 26, they also provide stable surface pressure and improve the sealing performance on the upper and lower surfaces of the ring groove. In addition, the outer peripheral shelf 18
generates a reaction force against the force that bends the spacer expander 12 into an annular shape, giving the expander 12 good elasticity.

The spacer expander 12 shown in FIG. 1 is obtained by press-molding the strip-shaped plate material shown in FIG. 3. That is, in a strip plate in which slits 20, 22 and an 11-shaped notch are formed in the central portion, the upper and lower edges 13' are moved toward the inner circumference along lines A-A and B-B, and into an H-shaped notch. It is obtained by bending the enclosed portion 18' toward the outer periphery.

A second embodiment is shown in FIGS. 4-6. The difference from the first embodiment is that a flat portion 15 bent at right angles toward the inner circumference is formed behind the inclined surface 14 and included in the inner circumference bent portion 13 . By doing so, as shown in FIG. 5, the flat portion 15 comes into surface contact with the upper and lower surfaces of the piston ring groove 28, resulting in a more stable mounting state. Further, like the outer peripheral shelf portion 18, the flat portion 15 generates a reaction force against the force that bends the spacer expander 12 into an annular shape, so that the elasticity of the spacer expander 12 is improved. Furthermore, since the slit 22 can be formed deep into the support portion 16, distortion of the expander 12 is eliminated.

The spacer extract Panda 12 shown in FIG. 4 is obtained by press-molding the strip material shown in FIG. 6. That is, the third
The top and bottom widths are thicker than those in the picture (pre-slit 20 mm).
．． 22, and a strip plate with an H-shaped notch formed in the center, move the upper and lower edges 13' toward the inner circumference along lines A-A, B-B, and C-C1D-D, and into the H-shaped notch. It is obtained by bending the enclosed portion 18' toward the outer periphery.

A third embodiment is shown in FIGS. 7 and 8. The basic configuration is the same as that of the second embodiment, but the vertical width of the spacer expander 12 is reduced by bending the center portion of the support portion 16 toward the outer circumferential side along the circumferential direction. By doing this, it is possible to cope with the case where the vertical width of the ring groove is made smaller than in the second embodiment without changing the basic structure.

A fourth embodiment is shown in FIGS. 9 and 10.

Contrary to the third embodiment, the vertical width of the spacer expander 12 is reduced by bending the central portion of the support portion 16 inward along the circumferential direction.

<Effects of the Invention> As described above, the spacer expander of the present invention has the following effects. In other words, (1) there is a sloped surface that contacts the inner circumference of the side rail and presses it vertically and outwardly over almost the entire circumference, so the contact rate is high, and therefore it is possible to provide uniform blood pressure and reduce surface pressure. becomes smaller, reducing wear on the side rail and spacer expander. (a) Since the outer peripheral shelf supports the upper and lower surfaces of the side rail, it provides stable surface pressure and improves the sealing performance on the upper and lower surfaces of the ring groove. (3) When the side rail receives pressure from the cylinder wall, the side rail The inclined surface that the inner periphery of the ring contacts is also pushed toward the inner periphery, and as a result, a force acts in the direction in which the upper and lower outer peripheral shelves are vertically separated from each other, improving the sealing performance of the upper and lower surfaces of the ring groove. (4) Ring If the width of the groove in the vertical direction is small, it can be easily mounted by bending the central portion of the support.

[Brief explanation of drawings]

Fig. 1 is a partial perspective view of the first embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view showing its usage, Fig. 3 is a plan view showing the strip plate material of the first embodiment, and Fig. 4 is a partial perspective view of the first embodiment of the present invention. A partial perspective view of the second embodiment,
Fig. 5 is a longitudinal cross-sectional view showing its usage state, Fig. 6 is a plan view showing the strip plate material of the second embodiment, Fig. 7 is a partial perspective view of the third embodiment, and Fig. 8 is its usage state. 9 is a partial perspective view of the fourth embodiment, and FIG. 10 is a longitudinal sectional view showing its use. In the figure, numeral 12 is a spacer expander, 13
14 is an inclined surface, 15 is a flat portion, 16 is a support portion, 18 is an outer shelf portion, 20.22 is a slit, and 26 is a side rail. Figure 3 Figure 5 Figure 6 Figure 8 Figure 2G

Claims (4)

[Claims] (1) In a spacer expander for a combination piston ring on which the two upper and lower side rails that slide with the cylinder are mounted and externally stretched, the spacer expander is made by bending the strip plate at the top and bottom of both side edges inward. formed by
An inner periphery bent part having an inclined surface for pressing the inner periphery of the side rail, a bearing part made up of the central part of the strip plate and connecting and supporting the upper and lower inner periphery bent parts, and a supporting part that extends in the circumferential direction. The outer shelf section is separated from the center part at regular intervals, opened on both sides toward the outer circumference side, and erected on the outer circumferential side at the upper and lower edges of the support part for the purpose of placing a side rail, and the space between the adjacent outer circumferential shelves sections. A spacer for a combination piston ring, characterized in that it is composed of slits cut symmetrically and alternately at right angles to the circumferential direction, and slits cut radially in the bent part of the inner circumference above and below the shelf part of the outer circumference. Expander. (2) The spacer expander for a combined piston ring according to claim 1, wherein the inner circumferential bent portion includes a flat portion bent at right angles to the inner circumferential side behind the inclined surface. (3) A spacer expander for a combined piston ring according to claims 1 and 2, characterized in that the central portion of the support portion is bent toward the outer circumferential side along the circumferential direction. (4) A spacer expander for a combined piston ring according to claims 1 and 2, characterized in that the central portion of the support portion is bent inward along the circumferential direction.