Patent Grant
10427206
The present invention relates to a target wheel for a camshaft phaser assembly.
Camshaft phaser assemblies are well known in the automotive field. It is also known to include a target wheel in camshaft phaser assemblies to determine an angular position of a phaser rotor. Known camshaft phaser assemblies including target wheels are disclosed in U.S. Pat. Nos. 7,305,949 and 6,609,498.
Target wheels are often formed from bent sheet metal to reduce pressing forces and maintain a relatively low rotating inertia. Sensor tabs can be formed around an outer periphery of the target wheel. A position sensor is arranged adjacent to the sensor tab to detect an angular position of a phaser rotor. Due to handling during installation, these types of targets wheels can undergo deformation. These target wheels may also include relatively brittle or weak tabs, or undergo installation issues. Any one of these issues can result in timing problems for the target wheel, and impact the ability of an associated sensor to detect a position of the camshaft.
One type of known sensor tab for target wheels includes rolled edges. However, these known types of sensor tabs result in outer corners formed by the rolled edges that have a relatively large radius. The relatively large radius caused by these rolled edges causes a delayed reading of the position of the sensor tab.
It would be desirable to provide an improved profile for sensor tabs of a target wheel that avoids inaccurate or delayed reading of a relative position of the sensor tabs to a sensor.
A method of forming a target wheel for a camshaft phaser assembly is disclosed. The method includes: (i) providing a sheet metal body, and (ii) stamping the sheet metal body to form at least one sensor tab along a radially outer edge of the sheet metal body. The at least one sensor tab includes a medial flange positioned between first and second axially extending edges. The at least one sensor tab includes: at least one inner corner defined between the medial flange and at least one of the first axially extending edge or the second axially extending edge, and at least one outer corner defined between the medial flange and at least one of the first axially extending edge or the second axially extending edge. The method includes (iii) forming a groove in the at least one inner corner.
In one embodiment, the at least one outer corner has a first radius prior to step (iii), and the at least one outer corner has a second radius that is less than the first radius after step (iii).
The groove formation results in material of the sheet metal body being forced from the inner corner to the outer corner, resulting in a smaller radius for the curvature defined by the outer corner between the medial flange and one of the axially extending edges.
In one embodiment, a target wheel for a camshaft phaser assembly is disclosed. The target wheel includes a sheet metal body including at least one sensor tab formed along a radially outer edge of the sheet metal body. The at least one sensor tab includes a medial flange positioned between first and second axially extending edges. The at least one sensor tab includes at least one inner corner defined between the medial flange and at least one of the first axially extending edge or the second axially extending edge. At least one outer corner is defined between the medial flange and at least one of the first axially extending edge or the second axially extending edge. A groove is formed in the at least one inner corner.
In one embodiment, the groove provides a localized reduced thickness of the sheet metal body at the at least one inner corner relative to areas of the sheet metal body away from the at least one inner corner.
The foregoing Summary and the following detailed description will be better understood when read in conjunction with the appended drawings, which illustrate a preferred embodiment of the invention. In the drawings:
Certain terminology is used in the following description for convenience only and is not limiting. The words “front,” “rear,” “upper” and “lower” designate directions in the drawings to which reference is made. The words “inwardly” and “outwardly” refer to directions toward and away from the parts referenced in the drawings. “Axially” refers to a direction along the axis of a shaft. A reference to a list of items that are cited as “at least one of a, b, or c” (where a, b, and c represent the items being listed) means any single one of the items a, b, or c, or combinations thereof. The terminology includes the words specifically noted above, derivatives thereof and words of similar import.
Referring to
In one embodiment, a sensor 18 is positioned adjacent to the target wheel 20. In one embodiment, the sensor 18 is positioned axially adjacent to the target wheel 20. The sensor 18 determines a position of the target wheel 20 based on positions of tabs formed on the target wheel 20. The sensor 18 can include any type of known sensor configuration, including an associated micro-processor based controller, CPU, data, and other electronic components.
The target wheel 20 includes a plurality of sensor tabs 22 along a radially outer edge 24 of the target wheel 20. Each of the sensor tabs 22 includes rolled edges with a medial flange 26 positioned between first and second axially extending edges 28a, 28b. These first and second axially extending edges 28a, 28b are also known as falling and rising edges. The sensor tab 22 includes at least one inner corner 30a defined between the medial flange 26 and at least one of the first axially extending edge 28a or the second axially extending edge 28b. The sensor tab 22 includes at least one outer corner 30b defined between the medial flange 26 and at least one of the first axially extending edge 28a or the second axially edge 28b.
In one embodiment, a method of forming a target wheel 20 for a camshaft phaser assembly 10 is disclosed. The method includes providing a sheet metal body, and stamping the sheet metal body to form at least one sensor tab 22 along a radially outer edge 24 of the sheet metal body. In one embodiment, the at least one sensor tab 22 includes two sensor tabs 22.
As shown in
In one embodiment, the method includes forming a groove 34 in the at least one inner corner 30a′ such that the at least one outer corner 30b′ defines a second radius (R2) that is less than the first radius (R1). As shown in
In one embodiment, the groove 34 is formed via stamping. One of ordinary skill in the art would recognize that a variety of formation processes could be used to form the groove 34.
By pushing material from the inner corner 30a to the outer corner 30b′, an associated sensor 18 can obtain a more reliable and accurate reading of the sensor tabs 22 due to a relatively thicker profile of the outer corner 30b′. This formation process avoids reading delays for the associated sensor 18 when detecting the sensor tab 22.
In one embodiment, the second radius (R2) is 40%-70% of the first radius (R1). In one embodiment, the first radius (R1) is 1.6 mm-2.0 mm. In one embodiment, the second radius (R2) is 0.8 mm-1.2 mm. One of ordinary skill in the art would understand that the radius of the outer corner 30b′ can be varied depending on a specific application. The present disclosure is generally directed to reducing a radius of the outer corner 30b′.
In one embodiment, the groove 34 has a depth of 0.3 mm-0.6 mm. In one embodiment, the groove has a length of 0.1 mm-0.5 mm. One of ordinary skill in the art would understand that the depth of the groove 34 can be varied depending upon a specific application.
One of ordinary skill in the art would understand that the formation methods for making the target wheel 20 and the associated features of the sensor tab 22 can include known manufacturing processes, such as disclosed in U.S. Pat. No. 8,171,902, which is incorporated by reference as if fully set forth herein. In one embodiment, the target wheel 20 is formed via a deep-drawing method, including a deep-drawing stamp, mold, mandrel, holder, etc.
In one embodiment, a target wheel 20 for a camshaft phaser assembly 10 is provided. The target wheel 20 includes a sheet metal body including at least one sensor tab 22 formed along a radially outer edge 24 of the sheet metal body. The at least one sensor tab 22 includes a medial flange 26 positioned between first and second axially extending edges 28a, 28b. The at least one sensor tab 22 includes at least one inner corner 30a defined between the medial flange 26 and at least one of the first axially extending edge 28a or the second axially extending edge 28b, and at least one outer corner 30b defined between the medial flange 26 and at least one of the first axially extending edge 28a or the second axially extending edge 28b.
As shown in
Although the groove 34 is generally shown on an inner face of the medial flange 26, one of ordinary skill in the art would understand that the groove 34 can be formed on an inner face of the axial edges 28a, 28b.
The present disclosure generally discloses reducing a curvature of an edge of a sensor stab for a target wheel to reduce reading delays between the target wheel and an associated sensor. The present disclosure reduces reading delays by forcing material of the sensor tab from an inner corner/region of the tab to an outer corner/region of the sensor tab, thereby provided a thicker profile to the outer corner/region. Therefore, more material of the sensor tab is provided in a region of the associated sensor to provide a quicker and more reliable reading.
Having thus described the present invention in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the invention, could be made without altering the inventive concepts and principles embodied therein. It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. The present embodiment and optional configurations are therefore to be considered in all respects as exemplary and/or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein.
| Number | Name | Date | Kind |
|---|---|---|---|
| 6609498 | Mathews et al. | Aug 2003 | B2 |
| 7305949 | McCarthy et al. | Dec 2007 | B2 |
| 7614370 | Fischer | Nov 2009 | B2 |
| 8171902 | Weber | May 2012 | B2 |
