JPH0610870U - Rotation sensor magnetic ring - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent deterioration such as cracks in the main body of the magnetic ring when it is press-fitted into the member to be detected. [Structure] The magnetic ring body 5 is formed of a resin material containing a magnetic material. The press-fitting portion 6 is formed of a resin material that does not contain a magnetic material and has high strength against stress.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotation sensor used for a vehicle wheel speed sensor or the like, and more particularly to a magnetic ring of a rotation sensor for detecting a rotation state by a magnetic detection method.

[0002]

[Prior art]

 As a rotation sensor used for automobile wheel speed sensors, a magnetic ring with multiple poles magnetized in the outer peripheral area is attached to the rotating shaft as the detected member, while the magnetic detection element is fixed facing the outer peripheral surface of the magnetic ring. There is a device that is attached to the member on the side to determine the rotation speed of the rotating shaft from the change in the magnetic flux detected by the magnetic detection element.

In recent years, as a magnetic ring of this type of rotation sensor, a so-called plastic magnet formed of a resin material containing a magnetic material has been widely used.

Incidentally, this related technique is disclosed in, for example, Japanese Utility Model Laid-Open No. 2-85661.

[0005]

[Problems to be solved by the device]

 However, since the magnetic ring made of resin contains a magnetic material such as metal, its strength against stress is weak, and when press-fitting to a member to be detected such as a rotating shaft, cracks etc. occur due to the stress. There is a possibility. As a mounting means for the member to be detected, in addition to press fitting, other modes such as bolt tightening can be considered, but in order to obtain high mounting accuracy relatively easily, press fitting is necessary, and from this viewpoint as well. The structural improvement of the above magnetic ring is desired.

Therefore, the present invention is intended to provide a magnetic ring made of resin for a rotation sensor, which does not cause deterioration such as cracks even if it is press-fitted into a detected part.

[0007]

[Means for Solving the Problems]

 According to the present invention, as a means for solving the above-mentioned problems, the press-fitting portion for the detected member is formed of a resin material different from that of the magnetic ring body.

[0008]

【Example】

 Next, an embodiment of the present invention will be described with reference to FIGS.

In the drawings, reference numeral 1 is a resin magnetic ring according to the present invention. As shown in FIG. 3, the magnetic ring 1 constitutes a rotation sensor together with the magnetic detection element 3 attached to the fixed member 2 and is integrally press-fitted onto the outer periphery of the rotary shaft 4 as the detected member. It can be attached to. As shown in FIGS. 1 and 2, the magnetic ring 1 includes a magnetic ring main body 5 which is multi-pole magnetized so that different magnetic poles (N pole and S pole) appear alternately along the circumferential direction. The magnetic ring body 5 is made of a resin material containing a magnetic body, and the press-fitting portion 6 is made of a resin material different from that of the magnetic ring body 5. More specifically, it is made of a resin material that does not contain a magnetic material and has high strength against stress. Further, the press-fitting portion 6 is provided with a plurality of arc-shaped meat-thief holes 7 along the circumferential direction, and the flexure deformation of the inner periphery of the press-fitting portion 6 is allowed by the meat-thief hole 7. There is. In manufacturing the magnetic ring 1, the magnetic ring body 5 is formed in advance, and the magnetic ring body 5 and the press-fitting portion 6 are integrated by insert molding.

Due to the above-mentioned configuration, most of the stress generated when the magnetic ring 1 is press-fitted into the rotary shaft 4 is due to the elasticity of the resin material itself forming the press-fitting portion 6 and the meat-thief hole 7. Absorbed by action and. Therefore, almost no stress is generated in the magnetic ring main body 5 which contains a magnetic material and has a relatively low strength against stress, and there is no fear that the magnetic ring main body 5 is deteriorated by cracks or the like.

The embodiment of the present invention is not limited to that shown in FIGS. 1 to 3, and for example, the press-fitting portion is provided on the outer peripheral side of the magnetic ring main body, and the magnetic ring is provided inside the annular portion of the detected member. May be attached.

[0012]

[Effect of device]

 As described above, the present invention makes it possible to increase the strength of the press-fitting portion without changing the performance of the magnetic ring body by forming the press-fitting portion for the detected member with a resin material different from the magnetic ring body. , When it is press-fitted into the detected member, deterioration such as cracks will not occur.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Magnetic ring, 5 ... Magnetic ring main body, 4 ... Rotation shaft (member to be detected), 6 ... Press fitting part.

Claims (1)

[Scope of utility model registration request] 1. A magnetic ring for a rotation sensor, comprising: a magnetic ring for a rotation sensor, which is made of a resin material; and a press-fitting portion for the member to be detected is made of a resin material different from that of the magnetic ring body.