Slide shoe for a piston for use in internal combustion engines

Abstract

A piston for an internal combustion engine has a sliding shoe carried in a force accumulator. The sliding shoe has a channel to transfer cooling oil into a hollow space. The force accumulator is located is a channel formed by the piston, and the sliding shoe is guided partially inside the force accumulator.

Claims

1. A piston for use in an internal combustion engine comprising: a piston upper part defining a hollow space; a piston lower part connected to the piston upper part, the piston lower part having a first wall and a second wall defining an elongate force accumulator channel radially spaced from a piston longitudinal axis, the piston lower part first wall further defining a central sleeve channel, the force accumulator channel is spaced radially outward from the central sleeve channel and radially separated by the piston lower part first wall; a force accumulator positioned in the force accumulator channel; and a sliding shoe comprising: a body having a first upwardly extending guide element axially and slidingly positioned in the central sleeve channel, the body and first upwardly extending guide element defining a sliding shoe central channel operative to allow passage of a medium through the sliding shoe to the piston upper hollow space; and a second upwardly extending guide element connected to the body positioned radially outward from the first upwardly extending guide element, the second upwardly extending guide element positioned in the force accumulator channel in biasing engagement with the force accumulator, the force accumulator operative to bias the sliding shoe away from the piston upper part.

2. The piston of claim 1 wherein the body is slidingly engaged with central sleeve channel.

3. The piston of claim 1 further comprising a disc positioned between the force accumulator and the second upwardly extending guide element.

4. The piston of claim 1 wherein the force accumulator channel is circumferentially positioned and radially outwardly spaced about the central sleeve channel.

5. The piston of claim 1 wherein the medium is cooling oil.

6. The piston of claim 1 wherein the sliding shoe body further comprises a retaining ring radially extending from the body first upwardly extending guide element, the retaining ring operable to prevent axial disengagement of the body from the central sleeve channel.

7. The piston of claim 1 wherein the force accumulator comprises a compression coil spring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The sliding shoe for a piston is further clarified using the Figures described in which:

(2) FIG. 1 shows a cross sectional view of a piston in accordance with the invention,

(3) FIG. 2 is an enlarged view of the area of the sliding shoe as detail II from FIG. 1; and

(4) FIG. 3 is an enlarged view of the guide for the sliding shoe as detail III from FIG. 2.

DETAILED DESCRIPTION

(5) In the following description of the Figures, terms such as top, bottom, left, right, front, rear, etc. refer solely to the representation and position of the device and other elements selected as an example in the respective Figures. These terms are not to be understood in a restrictive sense, that is to say these references can change as the result of different positions and/or mirror-image layout or similar.

(6) FIG. 1 shows a piston 1 that is made up of a piston lower part 2 and a piston upper part 3. The piston 1 possesses a sliding shoe 4. The sliding shoe 4 is pre-loaded by means of a force accumulator 5, designed as a compression spring, and further specifically as a coil spring. The pre-loading is effected against a connecting rod small end 8 in the case of a piston-connecting rod system. A disc 6, which transfers the forces from the force accumulator 5 to the sliding shoe 4, may be, but does not have to be, located between the force accumulator 5 and the sliding shoe 4. An optional retaining ring 7 is provided to prevent the sliding shoe 4 from falling out of the guide in the piston 1. The sliding shoe 4 with sliding elements 9 rests on the outer circumference of a connecting rod small end 8. The sliding shoe 4 has a central channel 10 to conduct a medium, for example, cooling oil, into a hollow space 11 of the piston 1. The channel 10 expands in a funnel shape towards the bottom (when viewing the Figures) in the direction of the connecting rod small end 8. As a result of the funnel-shaped construction, the medium can more easily reach the channel 10 from the connecting rod small end 8. The connecting rod small end 8 is supplied with the medium through a passageway in the connecting rod. The hollow space 10 is preferably located below the combustion chamber of the piston 1.

(7) FIG. 2 is a detail view of the area of the sliding shoe 4.

(8) FIG. 3 is a detail view of the guide for the sliding shoe 4. The guide for the sliding shoe 4 is provided by a radially circumferential channel 12. A radially circumferential guide element for the sliding shoe 4 is carried moveably in this channel 12. The channel 12 accommodates the force accumulator 5 and the disc 6. The disc 6 is supported on the guide element 13, and force from the force accumulator 5 drives the disc 6 towards the connecting rod small end 8. The force accumulator 5 is supported at an opposite end on the closed end area 14 of the channel 12. The sliding shoe 4 can additionally be, but does not have to be, guided in a central sleeve 15. This central sleeve is formed integrally with the piston lower part 2. The wall 16 of the central sleeve 15 simultaneously forms the boundary of the channel 12. The result of guiding the sliding shoe 4 and the central sleeve 15 in parallel in the channel 12 is a solid mount for the sliding shoe 4 in the piston 1.