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, 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 having: a second external diameter equal to the first external diameter; and, a second outer end having a contact area for a follower, and, the drive-side section and the output-side section are axially spaced apart from one another and are connected to one another by a central rod.

2. The tappet of claim 1, wherein a first central rod extension protrudes from the drive-side section and a second central rod extension protrudes from the output-side section, the first, central rod extension extending in a first direction toward the output-side section, and the second central rod extension extending in a second direction toward the drive-side section, and end faces of each of the first and second central rod extensions are joined together to form the central rod.

3. The tappet of claim 2, 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.

4. The tappet of claim 2, 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.

5. The tappet of claim 2, wherein the first and second central rod extensions are joined by a weld.

6. The tappet of claim 2, 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.

7. The tappet of claim 6, wherein each flat surface extends in the second direction to form a roof.

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

9. (canceled)

10. The tappet of claim 2, wherein the first central rod extension is formed integrally with a base of the drive-side section.

11. The tappet of claim 2, 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.

12. A tappet of an internal combustion engine, 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 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 between a first base of the drive-side section and a second base of the output-side section; and, the first guide shroud and the second guide shroud forming an empty space extending radially from an outer surface of the central rod to a third outer diameter, the third outer diameter equal to the first outer diameter.

13. The tappet of claim 12, wherein the drive-side section is shaped as a first cup-shaped hollow body and the output-side section is formed as a second cup-shaped hollow body, and the first base forms a first closed side of the first cup-shaped hollow body, and the second base forms a second closed side of the second cup-shaped hollow body.

14. The tappet of claim 13, wherein the first base includes through-openings configured to fluidly connect the empty space to the first cup-shaped hollow body.

15. The tappet of claim 13, wherein the first cup-shaped hollow body and the second cup-shaped hollow body open in a same direction.

16. The tappet of claim 15, wherein the central rod comprises a first central rod extension extending from the first base and a second central rod extension extending from the second base.

17. The tappet of claim 16, wherein the first and second central rod extensions are joined together by a weld.

18. The tappet of claim 12, wherein a longitudinal length of the central rod is greater than a diameter of the central rod.

19. A tappet of an internal combustion engine, 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 formed separately 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.

20. The tappet of claim 19, wherein the first cup-shaped hollow body has a first guide shroud, and the second cup-shaped hollow body has a second guide shroud, and an axial length of the central rod is longer than a first axial length of the first cup-shaped hollow body and a second axial length of the second cup-shaped hollow body.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The disclosure is explained with reference to the figures. In the figures:

[0017] FIG. 1 shows a spatial view of a tappet for a high-pressure fuel pump;

[0018] FIG. 2 shows a longitudinal section through the abovementioned tappet; and,

[0019] FIG. 3 shows a longitudinal section as mentioned above, but rotated by 90°.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] 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.

[0021] 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.

[0022] The output-side section 4 has, at its closed outer end 7, which thus lies on its base 14, a contact area 8 for a pump piston as a follower part.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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

[0027] 1 Tappet [0028] 2 Housing [0029] 3 Drive-side section [0030] 4 Output-side section [0031] 5 Outer end [0032] 6 Roller [0033] 7 Outer end [0034] 8 Contact area [0035] 9 Rod piece [0036] 10 Drive-side section extension [0037] 11 Output-side section extension [0038] 12 Terminal end [0039] 13 Terminal end [0040] 14 Drive-side section base [0041] 15 Output-side section base [0042] 16 Outer side [0043] 17 Inner side [0044] 18 Flat surface [0045] 19 Bore [0046] 20 Rolling bearing [0047] 21 Axle [0048] 22 Segment [0049] 23 Welding [0050] 24 Through-opening [0051] 25 Guide shroud [0052] 26 Guide shroud