Roller tappet for a fuel pump

Abstract

A roller tappet for a fuel pump is provided that has a guide housing which includes a drive-side and output-side section of the same external diameter, and a separate support body extending longitudinally through the guide housing. An upper face on the drive-side section carries a pin with a roller thereon. A lower face of the output-side section interacts at least indirectly with an arrangement for a pump piston. The drive-side section and the output-side section are axially spaced rings connected to one another via the support body. The support body has a first ring area with the upper face and a second ring area with the lower face. The first ring area is connected to an inner jacket of the drive-side section and the second ring area is connected to an inner jacket of the output-side section.

Claims

1. A roller tappet for an internal combustion engine, the roller tappet comprising: a guide housing including: a drive-side section having a first outer diameter, and an output-side section having a second outer diameter equal to the first outer diameter, the output-side section axially spaced from the drive-side section, a support body including: a first end defining first ring area configured to be fixed to the drive-side section and to receive a pin of a roller, and a second end defining a second ring area configured to be fixed to the output-side section and to receive a pump piston, wherein the first ring area is fixed to the second ring area via two longitudinal struts.

2. The roller tappet of claim 1, wherein the support body is produced in one piece from sheet steel by punching and bending.

3. The roller tappet of claim 1, wherein the first ring area is formed with two opposed flat, indented extensions respectively adjoined with the two longitudinal struts, each indented extension including a bore configured to receive the pin.

4. The roller tappet of claim 3, wherein the first ring area further comprises two opposed end faces configured to form a portion of the first ring area arranged outside of the two opposed flat, indented extensions.

5. The roller tappet of claim 4, wherein a first end face of the two opposed end faces is circumferentially offset from a second end face of the two opposed end faces.

6. The roller tappet of claim 4, wherein a first end face of the two opposed end faces engages a second end face of the two opposed end faces.

7. The roller tappet of claim 1, wherein the first ring area is configured to be fixed to a first inner jacket of the drive-side section and the second ring area is configured to be fixed to a second inner jacket of the output-side section.

8. The roller tappet of claim 1, wherein a sum of a first length of the two longitudinal struts radially covered by the drive-side section and a second length of the two longitudinal struts radially covered by the output-side section is less than an exposed length of the two longitudinal struts between the first drive-side section and the output-side section.

9. The roller tappet of claim 1, wherein the output-side section is formed with a transverse strut configured to abut against a lower axial face of the second ring area.

10. The roller tappet of claim 1, wherein at least one of the drive-side section or the output-side section is produced from sheet steel.

11. The roller tappet of claim 1, wherein the first ring area and the second ring area are respectively fixed to the drive-side section and the output-side section via welding, riveting, clipping, or press-fitting.

12. The roller tappet of claim 1, wherein: the first ring area comprises a first bore and a second bore configured to receive the pin, and the drive-side section comprises a third bore and a fourth bore respectively aligned with the first bore and the second bore.

13. The roller tappet of claim 1, wherein the output-side section comprises an anti-rotation body protruding from an outer jacket of the output-side section.

14. A tappet for an internal combustion engine, the tappet comprising: a drive-side housing having a first outer diameter, an output-side housing having a second outer diameter equal to the first outer diameter, the output-side housing axially spaced from the drive-side housing, and a support body including: a first ring area formed at a first end of the support body, the first ring area configured to be fixed to the drive-side housing, and a second ring area formed at a second end of the support body, the second ring area configured to be fixed to the output-side housing, wherein the first ring area is fixed to the second ring area via at least one longitudinal strut, and wherein the first ring area, the second ring area, and the at least one longitudinal strut are integrally formed from one piece.

15. The tappet of claim 14, wherein the first ring area, the second ring area, and the at least one longitudinal strut are integrally formed from one piece via bending of sheet steel.

16. The tappet of claim 15, wherein the drive-side housing and the output-side housing are formed as steel rings via a drawing process.

17. The tappet of claim 16, wherein the first ring area is configured to be fixed to a first inner jacket of the drive-side housing and the second ring area is configured to be fixed to a second inner jacket of the output-side housing.

18. The tappet of claim 17, wherein the output-side housing is formed with a transverse strut configured to abut against the second end of the support body.

19. The tappet of claim 17, wherein the first ring area is formed with two opposed flat, indented extensions each including a bore which are aligned so as to receive a pin of a roller.

20. A tappet for an internal combustion engine, the tappet comprising: a drive-side housing ring having a first outer diameter, an output-side housing ring having a second outer diameter equal to the first outer diameter, and a support body having: a first ring area configured to be fixed to the drive-side housing ring, the first ring area having two flat, indented extensions configured to receive a pin of a roller, and a second ring area configured to be fixed to the output-side housing ring, the second ring area axially spaced end from the first ring area, wherein the first ring area is fixed to the second ring area via at least one longitudinal strut, wherein the drive-side housing ring is axially spaced from the output-side housing ring such that a portion of the at least one longitudinal strut is exposed between the drive-side housing ring and the output-side housing ring in a longitudinal direction of the at least one longitudinal strut.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosure is explained with reference to the drawings.

(2) FIG. 1 shows a three-dimensional view of the roller tappet, partially broken up; and

(3) FIG. 2 shows the roller tappet in an exploded view.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(4) The figures show a roller tappet 1 for a fuel pump of an internal combustion engine. The roller tappet 1 is suitable for large installation spaces.

(5) The roller tappet 1 has a guide housing 2. This consists of a drive-side and an output-side section 3, 4 of the same external diameter. Both sections 3, 4 are separate and axially spaced rings made of sheet steel. A thin-walled and separate support body 5, likewise made of sheet steel, extends longitudinally through the two-part guide housing 2. The support body 5 carries a roller 9 on its upper face 7 on the drive-side section 3. The latter sits on a pin 21 which is inserted at the end into bores 20 of the support body 5.

(6) It can be seen that the support body 5 has a first ring area 12 with the upper face 7 and a second, axially spaced apart ring area 13 with the lower face 10. The ring areas 12, 13 are welded to the respective inner jackets 14, 15 of the sections 3, 4 and lie within their height. A one-piece connection of the ring areas 12, 13 is established via longitudinal struts 16 which extend from opposing inner faces 17, 18 of the ring areas 12, 13. As can best be seen in FIG. 1, the longitudinal struts 16 of the support body 5 are exposed over most of their length with respect to the sections 3, 4 of the guide housing 2.

(7) The aforementioned bores 20 for the pin 21 in the first ring area 12 lie in the circumferential section of the longitudinal struts 16, which are designed as planar, indented extensions 19. In alignment with these, the upper, drive-side section 3 has two bores 28. As shown in FIG. 1, the pin 21 does not protrude into these bores 28. The pin 21 can, however, sit in the bores 28, which would additionally fix the upper section 3.

(8) From FIG. 2 it can be seen that the support body 5, after punching of its contour, is simply bent around an imaginary center in the blank, which coincides with the axial line of its ring areas 12, 13 and at the same time of the roller tappet 1. End faces 22, 23 of the ring areas 12, 13 run towards one another in the final stage of the bending process, where the end faces 22 of the first, upper ring area 12 adjoin one another.

(9) As can also be seen from FIG. 2, the output-side section 4 of the guide housing 2 is provided in one piece with a transverse strut 25 at its output-side end 24. The areas lying on both sides of the transverse strut 25 are punched out. An arrangement 11 for a pump piston is formed on an underside 26 of the transverse strut 25. As shown, the second ring area 13 of the support body 5 rests with its lower face 10 on an inner surface 8 of the transverse strut 25.

(10) A separate anti-rotation body 6 also protrudes from an outer jacket 27 of the lower, output-side section 4 of the guide housing 2. It has a mushroom-shaped cross-section.

LIST OF REFERENCE CHARACTERS

(11) 1 Roller

(12) 2 Guide housing

(13) 3 Drive-side section

(14) 4 Output-side section

(15) 5 Support body

(16) 6 Anti-rotation body

(17) 7 Upper face

(18) 8 Inner face

(19) 9 Roller

(20) 10 Lower face

(21) 11 Arrangement

(22) 12 First ring area

(23) 13 Second ring area

(24) 14 Inner jacket

(25) 15 Inner jacket

(26) 16 Longitudinal strut

(27) 17 Inner face

(28) 18 Inner face

(29) 19 Extension

(30) 20 Bore

(31) 21 Pin

(32) 22 End face

(33) 23 End face

(34) 24 End

(35) 25 Transverse strut

(36) 26 Underside

(37) 27 Outer jacket

(38) 28 Bore