Tappet for acting on a pump piston of a high-pressure fuel pump

Abstract

The disclosure relates to a tappet for acting on a pump piston of a high-pressure fuel pump of an internal combustion engine. The tappet includes a tubular housing, and at the upper annular end face of the tubular housing, two surfaces which are indented relative to the outer casing of the housing and comprise a pin that supports a cam roller, lie diametrically opposite each other. An upper end face of a transverse beam lies against axial inner end faces of the two surfaces. A transverse beam lower end face, which faces a lower annular end face of the housing, is provided with a pin, which protrudes from the housing and is surrounded by a spring plate supported against the inner casing of the housing. A sleeve-like inner collar of the spring plate guides the unstepped pin.

Claims

1. A tappet configured for acting on a pump piston of a high-pressure fuel pump of an internal combustion engine, the tappet comprising: a tubular housing having two surfaces arranged diametrically opposite each other at an upper annular end face of the tubular housing, the two surfaces: i) indented relative to an outer casing of the tubular housing, and ii) comprising a first pin supporting a cam follower roller; a transverse beam having: an upper end face configured to lie against axial inner end faces of the two surfaces; and a lower end face facing a lower annular end face of the tubular housing is provided with a non-stepped second pin protruding from the tubular housing; and a spring plate attached to an inner casing of the tubular housing, the spring plate having: a sleeve-like inner collar configured to guide the non-stepped second pin, the sleeve-like inner collar having an annular end face facing the transverse beam in a direction of the inner casing of the tubular housing; and a wedged piece bent in a direction of the transverse beam and extending from the annular end face of the sleeve-like inner collar, and the transverse beam configured to be held relative to the two surfaces via an annular tip of the wedged piece and the non-stepped second pin configured as an adapter piece arranged between the tappet and the pump piston.

2. The tappet according to claim 1, wherein the axial inner end faces of the two surfaces are curved and complementary to at least a portion of the upper end face of the transverse beam.

3. The tappet according to claim 1, wherein the spring plate is spaced apart from the lower end face of the transverse beam via the annular tip.

4. The tappet according to claim 1, wherein the spring plate is attached to the inner casing of the tubular housing via an annular collar of the spring plate.

5. The tappet according to claim 4, wherein the annular collar of the spring plate is welded to the inner casing of the tubular housing.

6. The tappet according to claim 1, wherein the spring plate is provided with circumferentially distributed perforations.

7. The tappet according to claim 1, wherein the non-stepped second pin is longitudinally secured via a snap ring clip.

8. A tappet configured for acting on a pump piston of a high-pressure fuel pump of an internal combustion engine, the tappet comprising: a tubular housing having first and second indented surfaces arranged diametrically opposite each other at a first end of the tubular housing, the first and second indented surfaces configured to receive a first pin supporting a cam follower roller; a transverse beam having: an upper end face configured to engage: i) a first axial inner end face of the first indented surface, and ii) a second axial inner end face of the second indented surface; and a lower end face configured to engage a second pin, the second pin protruding beyond a lower annular end face of the tubular housing; a one-piece spring plate disposed within the tubular housing, the one-piece spring plate having: an annular collar configured to attach the one-piece spring plate to an inner casing of the tubular housing; and a sleeve-like inner collar configured to guide the second pin.

9. The tappet according to claim 8, wherein the first and second indented surfaces extend from an upper annular end face of the tubular housing.

10. The tappet according to claim 8, wherein the second pin is longitudinally secured via a snap ring clip.

11. The tappet according to claim 8, wherein the annular collar points downward and bears against the inner casing of the tubular housing.

12. The tappet according to claim 8, wherein the first and second axial inner end faces are curved.

13. The tappet according to claim 12, wherein portions of the upper end face that engage the first and second axial inner end faces are curved.

14. A tappet configured for acting on a pump piston of a high-pressure fuel pump of an internal combustion engine, the tappet comprising: a tubular housing having first and second indented surfaces arranged diametrically opposite each other at a first end of the tubular housing, the first and second indented surfaces configured to receive a first pin supporting a cam follower roller; a transverse beam having: an upper end face configured to engage: i) a first axial inner end face of the first indented surface, and ii) a second axial inner end face of the second indented surface; and a lower end face configured to engage a second pin, the second pin protruding beyond a lower annular end face of the tubular housing; a spring plate disposed within the tubular housing, the spring plate having a wedged piece comprising: a sleeve-like inner collar configured to guide the second pin, the sleeve-like inner collar having an annular end face; and from the annular end face, the spring plate extends radially outward and upward toward the lower end face of the transverse beam such that an annular tip is formed, the annular tip configured to rest against the lower end of the transverse beam; and from the annular tip, the spring plate extends radially outward and downward toward the lower annular end face of the tubular housing such that an annular collar is formed, the annular collar pointing downward and configured to attach the spring plate to an inner casing of the tubular housing.

15. The tappet according to claim 14, wherein the annular collar is attached to the inner casing of the tubular housing via welding.

16. The tappet according to claim 14, wherein the annular collar is attached to the inner casing of the tubular housing via a press-fit.

17. The tappet according to claim 1, wherein: when the spring plate is attached to an inner casing of the tubular housing in a first attached position, the non-stepped second pin protrudes beyond the annular tip of the spring plate to engage the lower end face of the transverse beam, the non-stepped second pin configured to protrude beyond the annular tip of the spring plate via the pump piston; and when the spring plate is attached to an inner casing of the tubular housing in a second attached position, the non-stepped second pin and spring plate are both engaged with the lower end face of the transverse beam, the non-stepped second pin configured to engage the lower end face via the pump piston.

18. The tappet according to claim 3, wherein the spring plate is continuously spaced apart from the lower end face of the transverse beam via the annular tip.

19. The tappet according to claim 8, wherein the second pin is not a pump piston of the high-pressure fuel pump.

20. The tappet according to claim 14, wherein: from the annular end face, the spring plate extends radially outward and upward at an angle toward the lower end face of the transverse beam, and from the annular tip, the spring plate extends radially outward and downward at an angle toward the lower annular end face.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) In the drawings:

(2) FIG. 1 shows the tappet in a spatial, partially broken open view, and

(3) FIG. 2 shows the tappet according to FIG. 1 in an exploded view.

DETAILED DESCRIPTION

(4) From FIGS. 1, 2, a tappet 1 is removable. This serves to load a pump piston of a high-pressure fuel pump of an internal combustion engine. The tappet 1 has a tube-like housing 2 made of thin-walled sheet steel with a height-to-diameter ratio in the range of about 1. In other words, the housing 2 is comparatively short.

(5) At an upper annular end face 3 of the housing 2, two surfaces 5 indented relative to an outer casing 4 of the housing 2 lie diametrically opposite one another. In these surfaces 5 sits a pin 7, which carries a cam follower roller 6 mounted on roller bearings. A comparatively narrow transverse beam 9 rests with its upper end face 10 on axial, secant-like inner end faces 8 of the surface 5, thus facing away from the upper annular end face 3. As can best be seen from FIG. 2, an upper end face 10 of the transverse beam 9 has a concave profile which is complementary to the inner end faces 8 of the surface 5. The transverse beam 9 has a width which corresponds approximately to the length of the surface 5.

(6) A pin 13 (see in particular FIG. 1) is seated on a lower end face 12 of the transverse beam 9, which faces a lower annular end face 11 of the housing 2. This protrudes beyond the lower annular end face 11 of the housing 2. The pin 13 is surrounded and guided by an inner collar 16 of a spring plate 15. The spring plate 15 consists of sheet steel.

(7) From an annular end face 17 of the inner collar 16 facing the transverse beam 9, the spring plate 15 is continued radially in the direction of the inner casing 14 of the housing 3 with a wedged piece 19 which has a bent profile in the direction of the transverse beam 9. Radially on the outside, the wedged piece 19 transitions into an annular collar 21 pointing downward, which bears against the inner casing 14 of the housing 2 and is welded to it. At the same time, the wedged piece 19 rests via its annular tip 20 against the lower end face 12 of the transverse beam 9 (see FIG. 1) and ultimately braces it against the surface 5.

(8) Alternatively, the spring plate 15 with its annular tip 20 can also be slightly spaced apart from the wedged piece 19. In this design, a certain angular mobility of the transverse beam 9 with the pin 13 seated on it is made possible in relation to the surface 5 for the purpose of compensating for perpendicularity errors in the drive.

(9) As shown in FIG. 2, the spring plate 15 is provided with a plurality of circular perforations 22 for media to pass through when the tappet 1 is in oscillating operation.

(10) In addition, FIG. 1 shows that the pin 13 is captively secured on the spring plate 15 by a snap ring clip 18.

(11) It should be noted that the pin 13 is a very simple extension of the tappet 1 and ultimately acts as an adapter piece between the tappet 1 and the pump piston and does not represent the pump piston.

LIST OF REFERENCE SYMBOLS

(12) 1 Tappet 2 Housing 3 Upper annular end face 4 Outer casing 5 Surface 6 Cam follower roller 7 Pin 8 Inner end face 9 Transverse beam 10 Upper end face 11 Lower annular end face 12 Lower end face 13 Pin 14 Inner casing 15 Spring plate 16 Inner collar 17 Annular end face 18 Snap ring clip 19 Wedged piece 20 Annular tip 21 Annular collar 22 Perforation