Method for manufacturing a piston indicator for a camshaft

Abstract

A method for manufacturing a position indicator sensor wheel for a camshaft is disclosed. The position indicator includes an axially extending passage for connecting to the camshaft and at least one radially projecting tooth. The method includes providing a sheet from a sheet material; introducing the passage into the sheet; and roughening a radial inner surface of the passage in at least one rough portion.

Claims

1. A method for manufacturing a position indicator sensor wheel for a camshaft, wherein the position indicator comprises an axially extending passage for connecting to the camshaft and at least one radially projecting tooth, the method comprising: providing a sheet from a sheet material, introducing the passage into the sheet, and roughening a radial inner surface of the passage in at least one rough portion.

2. The method according to claim 1, wherein the radial inner surface of the passage is roughened in at least two rough portions spaced apart from one another in a circumferential direction, the at least two rough portions separated from one another by unroughened smooth portions in the circumferential direction.

3. The method according to claim 1, wherein on the at least one rough portion the radial inner surface is shot-blasted with a roughening material for roughening.

4. The method according to claim 3, wherein the roughening material used for shot-blasting differs from the sheet material.

5. The method according to claim 3, wherein the roughening material is composed of steel.

6. The method according to claim 1, wherein the sheet material is a sheet made of steel.

7. The method according to claim 1, wherein roughening the radial inner surface includes introducing at least one embossment into the at least one rough portion.

8. The method according to claim 7, wherein into the at least one rough portion at least one dot embossment is introduced.

9. The method according to claim 7, wherein the at least one rough portion is knurled for roughening.

10. The method according to claim 1, wherein the at least one rough portion is roughened such that the at least one rough portion has a mean roughness depth between 5 and 30.

11. A position indicator for a camshaft, wherein the position indicator is manufactured in accordance with the method according to claim 1.

12. A method for manufacturing a camshaft for an internal combustion engine, comprising: providing a shaft, providing a position indicator, the position indicator including an axially extending passage for connecting to the shaft and at least one radially projecting tooth, wherein providing the position indicator includes: providing a sheet from a sheet material, introducing the passage into the sheet, and roughening a radial inner surface of the passage in at least one rough portion, joining the position indicator with the shaft via the passage, so that the position indicator is connected to the shaft so as to be axially fixed and non-rotatable.

13. The method according to claim 12, wherein the position indicator is joined with the shaft at room temperature.

14. The method according to claim 12, wherein the position indicator is joined with the shaft via a press fit.

15. The method according to claim 12, wherein roughening the radial inner surface of the passage includes roughening the radially inner surface in at least two rough portions spaced apart from one another in a circumferential direction and separated from one another by an unroughened smooth portion in the circumferential direction.

16. The method according to claim 12, wherein the sheet material is made of cold-formable steel.

17. The method according to claim 12, wherein the position indictor is joined with the shaft via a longitudinal press-fit.

18. A camshaft for an internal combustion engine, comprising: a shaft, a position indicator, the position indicator including an axially extending passage and at least one radially projecting tooth, the passage having a radial inner surface provided with at least one roughened portion, wherein the position indicator is joined with the shaft via the passage so as to be axially fixed and non-rotatable.

19. The camshaft according to claim 18, wherein the radial inner surface of the passage includes at least two rough portions spaced apart from one another in a circumferential direction and separated from one another by an unroughened smooth portion in the circumferential direction.

20. The camshaft according to claim 18, wherein the position indicator is press-fitted to the shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) It shows, in each case schematically

(2) FIG. 1 a highly simplified section through a camshaft having a position indicator,

(3) FIG. 2 an isometric view of the position indicator.

DETAILED DESCRIPTION

(4) A position indicator 1, as is shown in the FIGS. 1 and 2, is employed in a camshaft 100 shown in FIG. 1 in a greatly simplified manner. In the exemplary embodiment shown in FIG. 1, the camshaft 100 purely exemplarily comprises a single shaft 101, with which the position indicator 1 is joined. It is also conceivable that the camshaft 102 comprises shafts (not shown) which are arranged within one another and are adjustable relative to one another. The shaft 101 is rotatable about an axial axis of rotation 200 and during the operation rotates about the axis of rotation 200. The position indicator 1 is joined with a shaft 101 of the camshaft 100 so as to be non-rotatable and axially fixed. For this purpose, the position indicator 1 comprises an axial passage 9 which in the state joined with the shaft 101 assumes the function of a joint seat 2, by means of which the position indicator 1 is joined with the shaft 101. In the present context, the passage 9 and the joint seat 2 are to be understood as corresponding to one another. The camshaft 1, further, comprises cam bodies 102 that are non-rotatably connected to the shaft 101, which in an associated internal combustion engine which is not otherwise shown can actuate valves. In FIG. 1, a single such cam body 102 is shown.

(5) The directions stated here relate to the axial axis of rotation 200 of the shaft 101, which corresponds to the axis of rotation 200 of the position indicator 1. Accordingly, axial runs parallel, in particular coaxially to the axis of rotation 200. Further, radial runs transversely to the axis of rotation 200 or transversely to axial. In addition, the circumferential direction 200 runs so as to surround the axis of rotation 200.

(6) During the operation, the position indicator 1 rotates with the shaft 101 and interacts with a sensor 103, in order to determine the relative rotary position of the camshaft 100, in particular of the cam bodies 102. For this purpose, the position indicator 1 has a contour that changes in the circumferential direction 200. As is evident in particular from FIG. 2, the position indicator 1 for this purpose comprises at least one radially projecting tooth 3. Thus it is possible for example to control the camshaft 100 and/or the associated internal combustion engine that is not shown.

(7) In the exemplary embodiment shown in FIG. 2, the position indicator 1 purely exemplarily comprises four such teeth 3, wherein the teeth 3 are separated from one another in the circumferential direction 201 by tooth gaps 4. In the shown exemplary embodiment, the teeth 3 purely exemplarily extend differently in the circumferential direction 201.

(8) The position indicator 1 is manufactured from a sheet, i.e. is in particular a sheet position indicator 1. For manufacturing the position indicator 1, a sheet from a sheet material is provided. The joint seat 2 is advantageously manufactured in that initially a passage (not shown) is introduced into the sheet, for example punched. The passage 6 is expanded and calibrated to form the joint seat 2 using a calibrating mandrel that is not shown. The joint seat 2 is introduced in the shown exemplary embodiments in such a manner that the joint seat 2 is formed in an axially projecting flange 5. Further, the sheet is formed and cut free in such a manner that the teeth 3 and the tooth gaps 4 are formed. The passage 9, which then assumes the function of the joint seat 2, has a radial inner surface 6. As is merely evident from FIG. 2, the inner surface 6 is roughened in at least one portion 7, which in the following is also referred to as rough portion 7. Thus, a more stable non-rotatable and axially fixed connection between the position indicator 1 and the shaft 101 and thus an altogether more stable tight fit of the position sensor 1 on the shaft 101 materialises. At the same time, the position indicator 1 is cost-effective and has a reduced weight. Preferably, the inner surface 6 is roughened in the at least one rough portion 7 in such a manner that the at least one rough portion 7 has a mean roughness depth Rz between 5 and 30.

(9) Advantageously, the sheet is a formable preferably cold-formable steel. For example, the sheet consists of a steel according to DIN 10130, in particular steel according to DC01 to DC04.

(10) Basically, the entire inner surface 6 of the joint seat 2 can be roughened.

(11) In the exemplary embodiment shown in FIG. 2, at least two rough portions 7 are introduced into the inner surface 6. In FIG. 2, the rough portions 7 are indicated in a simplified manner by circles. The rough portions 7 are separated from one another in the circumferential direction 201 by portions 8, which are unroughened, i.e. free of such roughening and are also referred to as smooth portions 8 in the following. In the shown exemplary embodiment, rough portions 7 and smooth portions 8 thus alternate in the circumferential direction 201. In the shown exemplary embodiments, the rough portions 7 are additionally introduced locally and at points in the inner surface 6.

(12) The respective rough portions 7 can be introduced into the inner surface 6 in any way.

(13) At least one of the rough portions 7, in particular all rough portions 7, can be shot-blasted with a roughening material for roughening. This means that at least one of the rough portions 7, in particular the respective rough portion 7, is manufactured by means of shot-blasting with the roughening material. The roughening material is preferentially distinct from the sheet material and preferably likewise a steel.

(14) At least one of the rough portions 7, advantageously the respective rough portions 7, can alternatively or additionally be manufactured by an embossment of the inner surface 6. This means that in at least one of the at least one rough portions 7, advantageously in the respective rough portions 7, at least one embossment is introduced for roughening. The embossment can be a dot embossment. Likewise, the embossment can be a knurling. This means that at least one of the rough portions 7 is knurled for roughening.

(15) The position indicator 1, in particular the inner surface 6 with the at least one rough portion 7 allows joining the position indicator 1 with the shaft 101 by a press fit, wherein the press fit can take place at room temperature. The position indicator 1 is preferably joined with the shaft 101 by means of a longitudinal press fit.