Tappet for a fuel pump or for a valve drive

Abstract

The disclosure proposes a tappet with a housing which is composed of a drive-side and an output-side section. The drive-side section, at its outer end, has a roller and the output-side section, at its outer end, has a contact area for a follower part. The separate sections are axially spaced apart from one another and are connected to one another by a central rod piece.

Claims

1. A tappet of an internal combustion engine, the tappet comprising: a housing including: a drive-side section having: a first external diameter; and a first outer end having a roller; and an output-side section axially spaced from the drive-side section, the output-side section having: a second external diameter equal to the first external diameter; and a second outer end having a contact area configured to engage a follower, wherein the drive-side section and the output-side section are connected to one another via a central rod, and wherein the central rod includes a first central rod extension and a second central rod extension respectively protruding from the drive-side section and the output-side section such that a first end face of the first central rod extension is joined with a second end face of the second central rod extension.

2. The tappet of claim 1, wherein the drive-side section is formed as a cup-shaped hollow body having a base and an outer end, the base facing away from the outer end, and the first central rod extension extends from the base.

3. The tappet of claim 1, wherein the output-side section is formed as a cup-shaped hollow body having a base, an outer side of the base having a contact surface configured for contacting the follower, wherein the second central rod extension extends from an inner side of the base.

4. The tappet of claim 1, wherein the first end face is joined with the second end face via a weld.

5. The tappet of claim 1, wherein the drive-side section has two diametrically opposed flat surfaces, each flat surface having a bore configured to receive an axle supporting a rolling or sliding bearing of the roller.

6. The tappet of claim 5, wherein each flat surface extends in the second direction so as to form a roof above the first outer end.

7. The tappet of claim 1, wherein at least one of the drive-side or output-side sections is manufactured from sheet steel.

8. The tappet of claim 1, wherein the first central rod extension is formed integrally with a base of the drive-side section.

9. The tappet of claim 1, wherein the second central rod extension extends from an inner side of a base of the output-side section and through an open inner end of the output-side section.

10. A tappet of an internal combustion engine, the tappet comprising: a housing having: a drive-side section including a first guide shroud having a first outer diameter; an output-side section including a second guide shroud axially spaced from the first guide shroud, the second guide shroud having a second outer diameter equal to the first outer diameter; and a central rod configured to connect the drive-side section to the output-side section, the central rod extending from a first base of the drive-side section to a second base of the output-side section, wherein the drive-side section is shaped as a first cup-shaped hollow body including a first closed end defining the first base, wherein the output-side section is shaped as a second cup-shaped hollow body including a second closed end defining the second base, and wherein the first and second cup-shaped hollow bodies open in a same direction.

11. The tappet of claim 10, wherein the first base includes through-openings configured to convey a fluid.

12. The tappet of claim 10, wherein the central rod comprises a first central rod extension and a second central rod extension respectively extending from the first base and the second base.

13. The tappet of claim 12, wherein the first central rod extension is joined with the second central rod extension via a weld.

14. The tappet of claim 10, wherein a longitudinal length of the central rod is greater than a diameter of the central rod.

15. A tappet of an internal combustion engine, the tappet comprising: a housing having: a first cup-shaped hollow body opening in a first direction; a second cup-shaped hollow body opening in the first direction, the second cup-shaped hollow body axially spaced from the first cup-shaped hollow body; and a central rod configured to connect a first base of the first cup-shaped hollow body to a second base of the second cup-shaped hollow body.

16. The tappet of claim 15, wherein the first cup-shaped hollow body has a first guide shroud with a first axial length, and the second cup-shaped hollow body has a second guide shroud with a second axial length, and wherein an axial length of the central rod is greater than the first axial length and the second axial length.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The disclosure is explained with reference to the figures. In the figures:

(2) FIG. 1 shows a spatial view of a tappet for a high-pressure fuel pump;

(3) FIG. 2 shows a longitudinal section through the abovementioned tappet; and,

(4) FIG. 3 shows a longitudinal section as mentioned above, but rotated by 90°.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(5) A tappet 1 for a high-pressure fuel pump of an internal combustion engine is shown. The tappet 1 has a two-part, built-up 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 designed as cup-shaped hollow bodies. The upper, drive-side section 3 is essentially formed from a standard pump tappet body. The lower, output-side section 4, on the other hand, is shown as a standard cup tappet body shortened in height, as is used in directly actuated valve drives. Both sections 3, 4 are open in the same direction upwards, i.e., in the cam or drive direction.

(6) At its outer end 5, the drive-side section 3 has a roller 6 mounted on an axle 21 via a rolling bearing 20 (needle bearing). At the end, the axle 21 is seated in bores 19 of flat surfaces 18. These start from an outer end 5 of the drive-side section 3 and, as disclosed in FIG. 3, extend over more than half the height of a guide shroud 25 of the drive-side section 3. FIG. 1 best shows that each of the above-mentioned flat surfaces 18 runs in a segment 22 raised like a roof in relation to the outer end 5 of the drive-side section 3, in which segment 22 the respective bore 19 is located in sections.

(7) The output-side section 4 has, at its closed outer end 7, which thus lies on its base 15, a contact area 8 for a pump piston as a follower part.

(8) As can be seen, the separate sections 3, 4 are clearly spaced apart from one another axially and are connected to one another by a central rod piece 9.

(9) This rod piece 9 is composed of two extensions 10, 11. The integrally connected rod-like extension 10 extends from the base 14 of the upper section 3 in the direction of the lower section 4. At the same time, from an inner side 17 of a base 15 of the lower section 4, an integrally formed, likewise rod-like extension 11 extends through the latter. The extensions 10, 11 are connected by a welding 23 in the region of their adjoining terminal ends 12, 13.

(10) The tappet 1 is ideal for long installation lengths; here with pump drives. Guide shrouds 25, 26 of its sections 3, 4 have the same outer diameter and can be ground in one go.

(11) In FIG. 2, through-openings 24 are also shown in the base 14 of the drive-side section 3. These provide an unhindered passage of oil or fuel or air (here the keyword is: “prevention of inflation”) and can also lie in the base 15 of the output-side section 4.

LIST OF REFERENCE SYMBOLS

(12) 1 Tappet 2 Housing 3 Drive-side section 4 Output-side section 5 Outer end 6 Roller 7 Outer end 8 Contact area 9 Rod piece 10 Drive-side section extension 11 Output-side section extension 12 Terminal end 13 Terminal end 14 Drive-side section base 15 Output-side section base 16 Outer side 17 Inner side 18 Flat surface 19 Bore 20 Rolling bearing 21 Axle 22 Segment 23 Welding 24 Through-opening 25 Guide shroud 26 Guide shroud