MULTI-PART ROLLER TAPPET

Abstract

A roller tappet, in particular for a high-pressure fuel pump, is provided that is guided in the direction of the longitudinal axis thereof in a housing receptacle and is driven translatably in the longitudinal direction by cams of a camshaft. The roller tappet has a tappet body. This tappet body has a tappet skirt, a pump piston contact point (9), and a rotatably mounted roller (4), by which the roller tappet is supported on the camshaft. The tappet body has a guide cylinder (1), which is mounted in the housing receptacle and on which the roller (4) is supported, and a cup-shaped sleeve (7) having the pump piston contact point (9), which cup-shaped sleeve is supported in the guide cylinder (1) by a radial ring (8). A cylindrical constriction (5) is formed in the guide cylinder (1) in the region of the radial ring support.

Claims

1. A roller tappet for a high-pressure fuel pump, which is adapted to be guided in a direction of a longitudinal axis thereof in a housing receptacle and is adapted to be driven displaceably in a longitudinal direction by cams of a camshaft, the roller tappet comprising: a tappet body including a tappet skirt, a pump piston contact point, and a rotatably mounted roller, via which the roller tappet is supported on the camshaft, the tappet body further comprises: a guide cylinder which is adapted to be mounted in the housing receptacle and on which the roller is supported, a cup-shaped sleeve having the pump piston contact point and arranged inside the guide cylinder, a radially outwardly oriented radial ring on the sleeve located between axial ends of the sleeve, a cylindrical constriction located on the guide cylinder, a constriction groove inside the constriction of the guide cylinder, and the radial ring of the cup-shaped sleeve is attached to an inner casing of the constriction groove.

2. The roller tappet as claimed in claim 1, wherein the constriction has a depth and axial extent such that a widening of a region thereof resulting from the support of the radial ring on the guide cylinder remains arranged inside the remaining casing surface(s) of the guide cylinder.

3. The roller tappet as claimed in claim 1, wherein the constriction groove is stamped inside the constriction.

4. A roller tappet for a high-pressure fuel pump, the roller tappet comprising: a tappet body including: a guide cylinder which is adapted to be mounted in a housing receptacle and on which a roller that is adapted to contact a cam is rotatably supported, a cup-shaped sleeve having a pump piston contact point and arranged inside the guide cylinder, a radially outwardly oriented radial ring on the sleeve located between axial ends of the sleeve, a cylindrical constriction on the guide cylinder, a constriction groove inside the cylindrical constriction of the guide cylinder, and the radial ring of the cup-shaped sleeve is attached to an inner casing of the constriction groove.

5. The roller tappet of claim 4, further comprising an interference fit between the constriction groove and the radial ring.

6. The roller tappet of claim 4, wherein the cylindrical constriction has a depth and axial extent such that a widening of a region thereof resulting from the support of the radial ring on the guide cylinder remains arranged inside a remaining casing surface of the guide cylinder.

7. The roller tappet of claim 4, wherein the cylindrical constriction is located at a medial position.

8. The roller tappet of claim 4, wherein the roller is located at least partially within the guide cylinder.

9. The roller tappet of claim 4, wherein the pump piston contact point is located within the guide cylinder.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The disclosure is described in the drawings:

[0012] FIG. 1 shows a perspective exterior view of a roller tappet with a partial section through the tappet,

[0013] FIG. 2 shows the section through the roller tappet with a cross-section through the roller, and

[0014] FIG. 3 shows a section through the roller tappet which is rotated through 90 relative to FIG. 2.

DETAILED DESCRIPTION

[0015] In FIGS. 1 to 3, reference sign 1 designates a guide cylinder, on which a pin 2 is pivotably mounted; said pin supports a bearing sleeve 3 which in turn supports a roller 4. In its casing region, the guide cylinder 1 has a constriction 5 which can be produced by rolling. Furthermore, a constriction groove 6 is machined, either by stamping or also by rolling, into the constriction and hence also extends inwardly. A cup-shaped sleeve 7 is inserted in the guide cylinder 1 and, in addition to a longitudinal support on the guide cylinder 1 in the region of the roller 4, has a radial ring 8, the outer surface of which is fitted precisely into the finely machined inner casing of the constriction groove 6. At its end facing away from the roller 4, the cup-shaped sleeve 7 furthermore has a pump piston contact point 9 which, in its shape and strength, is adapted to the forces for the pump piston. The radial ring 8 may be pressed, welded, glued or otherwise attached in the inner casing of the constriction groove 6. The constriction 5, in conjunction with the support of the radial ring 8 on the constriction groove 6, receives a component deformation within the constriction 5 which remains inside the casing of the guide cylinder 1.

LIST OF REFERENCE SIGNS

[0016] 1) Guide cylinder

[0017] 2) Pin

[0018] 3) Bearing sleeve

[0019] 4) Roller

[0020] 5) Constriction

[0021] 6) Constriction groove

[0022] 7) Cup-shaped sleeve

[0023] 8) Radial ring

[0024] 9) Pump piston contact point