GALLERY-COOLED PISTON WITH A FUNNEL-SHAPED INLET INTO THE COOLING GALLERY

Abstract

A gallery-cooled piston with a cooling gallery or a cooling chamber in the region of the piston crown of the gallery-cooled piston. At least one opening having a funnel-shaped inlet is provided from an inner region of the gallery-cooled piston to the cooling gallery or the cooling chamber. A funnel-shaped tube is inserted into and fixed in the at least one opening after the production of the gallery-cooled piston.

Claims

1. A gallery-cooled piston having a cooling gallery positioned in the region of a piston crown the gallery-cooled piston defining at least one opening extending from an inner region of the gallery-cooled piston to the cooling gallery and having a funnel-shaped inlet, characterized in that a funnel-shaped tube is inserted and fixed in the at least one opening after the gallery-cooled piston has been produced.

2. The gallery-cooled piston of claim 1, characterized in that the funnel-shaped tube is pressed into the at least one opening.

3. The gallery-cooled piston of claim 1, characterized in that the funnel-shaped tube is fixed in the at least one opening by a snap-on connection.

4. The gallery-cooled piston of claim 1, characterized in that the funnel-shaped tube is fixed in the at least one opening by welding.

5. The gallery-cooled piston of claim 1, characterized in that the funnel-shaped tube axially projects beyond an entrance region of the at least one opening into the cooling gallery.

6. A method for producing a funnel-shaped tube for use in the gallery-cooled piston of claim 1, characterized in that the funnel-shaped tube is produced by rolling a sheet metal material which has been cut to size.

7. The method of claim 6, characterized in that after rolling, joint edges of the funnel-shaped tube are fastened to one another by a joining process point by point or in sections or over an entire length of the joint edges.

8. The method of claim 7, characterized in that after rolling, the joint edges of the funnel-shaped tube are arranged in an overlapping manner.

9. The gallery-cooled piston of claim 1, characterized in that latching lugs are formed in a wall of the funnel-shaped tube.

10. The gallery-cooled piston of claim 2, characterized in that the funnel-shaped tube is fixed in the at least one opening by welding.

11. A gallery-cooled piston for use in an internal combustion engine comprising: a piston crown defining a cooling gallery and an inner region, the piston crown defining at least one opening in communication with the cooling gallery and the inner region; and a funnel-shaped tube axially positioned in the at least one opening and fixed to the piston crown, the funnel-shaped tube operable to allow a cooling medium to pass between the cooling gallery and the inner region.

12. The piston of claim 11 wherein the funnel-shaped tube further comprises: a single piece of sheet material having joint edges connected to one another to form the funnel shaped tube.

13. The piston of claim 12 wherein the funnel-shaped tube joint edges are connected together by welding.

14. The piston of claim 11 wherein the funnel-shaped tube further comprises a pair of latching lugs formed in a circumferential wall of the funnel-shaped tube, the latching lugs extending radially outward from a longitudinal axis of the funnel-shaped tube.

15. The piston of claim 14 wherein the latching lugs are positioned diametrically opposite one another.

16. The piston of claim 15 wherein the funnel-shaped tube includes a length between opposite ends of the funnel-shaped tube, the latching lugs are positioned at a mid-point along the length between the opposite ends.

17. The piston of claim 15 wherein the at least one opening further defines recesses positioned to receive the respective latching lugs through the recesses to fix the funnel-shaped tube to the piston crown.

18. The piston of claim 11 wherein the funnel-shaped tube includes a first end an opposite second end, the funnel-shaped tube is positioned and fixed to the piston crown having the first end extending axially into the cooling gallery.

19. The piston of claim 18 wherein the piston crown further comprises a banking region extending into the cooling gallery around the at least one opening.

20. The piston of claim 18 wherein the funnel-shaped tube second end axially extends into the interior region.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Exemplary embodiments of the invention are shown in simplified form in the drawings. In the drawings:

[0014] FIG. 1 is a perspective view of a funnel-shaped tube;

[0015] FIG. 2 is a cross-sectional view taken along line A-A in FIG. 5.

[0016] FIG. 3 is a front view of the funnel-shaped tube in FIG. 1.

[0017] FIG. 4 is a cross-sectional view taken along line B-B in FIG. 3.

[0018] FIG. 5 is a rotated top view of FIG. 3.

[0019] FIG. 6 is a bottom view of FIG. 3.

[0020] FIG. 7 is a front view of a gallery-cooled piston.

[0021] FIG. 8 is a bottom view of the gallery-cooled piston in FIG. 7.

[0022] FIG. 9 is a cross-sectional view taken along line C-C in FIG. 8.

[0023] FIG. 10 is a rotated cross-sectional view taken along line D-D in FIG. 8.

DETAILED DESCRIPTION

[0024] In FIGS. 1 to 6 the funnel-shaped tube which is produced separately from the main piston body, in particular the piston blank, is designated 1 and depicted in multiple views and in two sections. The funnel-shaped tube 1 is produced from a suitable sheet metal material, for example, by a rolling process. The joint edges designated 2 and 3 can be arranged in an overlapping or abutting manner in this case. In both cases, either a joining process for connecting the two joint edges 2 and 3 can be omitted, or it can take place point by point, in sections, or over the entire length. In the exemplary embodiment according to FIGS. 1 to 6, the joint edges 2 and 3 overlap, a joining process for connecting the two joint edges 2 and 3 being omitted. Two projecting latching lugs 4 and 5 are provided roughly in the center of the longitudinal extent of the funnel-shaped tube 1. The two latching lugs 4 and 5 are diametrically opposite one another in this exemplary embodiment. More than two latching lugs, or similar, can of course also be provided over the circumference of the funnel-shaped tube 1 and/or the axial extent thereof. Recesses which preferably have a ring-shaped design and which are assigned to the latching lugs 4 and 5 can be provided in the opening of the gallery-cooled piston. By means of these latching means, in particular latching lugs 4, 5, or similar, the funnel-shaped tube 1 is inserted in the opening in the piston blank, which opening may be cylindrical or have another shape, e.g. conical, and fastened there. The funnel-shaped tube 1 can also be fixed by a joining method, e.g. spot welding or continuous welding, by an adhesive process, or similar. The latching means, in particular the latching lugs 4 and 5, moreover cause the funnel-shaped tube 1 to be fixed in the opening in the piston blank in such a manner that said funnel-shaped tube 1 can no longer move from the opening into the inner region of the gallery-cooled piston.

[0025] The gallery-cooled piston shown in FIGS. 7 to 10 is designated 6. The gallery-cooled piston 6 has bolt bores 7, via which it is connected to a connection rod of the internal combustion engine (not shown). The bolt bores 7 are arranged in the wall of the inner region 8 of the gallery-cooled piston 6. A cooling gallery 9, which extends as far as the piston crown 10, is attached to the inner region 8. Two openings 11, 12 in which funnel-shaped tubes 1 are inserted and fixed in accordance with the previously described measures are provided between the cooling gallery 9 and the inner region 8 of the gallery-cooled piston 6.

[0026] The tubes 1 are depicted in cylindrical-shaped form in FIGS. 8 and 10. However, they are actually funnel-shaped tubes, or corresponding variations, which may also be in the shape of a cone or truncated cone.

LIST OF REFERENCE SIGNS

[0027] 1 funnel-shaped tube [0028] 2, 3 joint edges [0029] 4, 5 latching lugs [0030] 6 gallery-cooled piston [0031] 7 bolt bore [0032] 8 inner region [0033] 9 cooling gallery [0034] 10 piston crown [0035] 11, 12 openings