JP3010090U - Rotor for rotation sensor - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a rotor for a rotation sensor, which is smaller and lighter than a conventional product, more accurately detects a pulse signal at the time of detection, improves rust prevention, and is cheaper. [Structure] A thin plate-shaped metal magnetic body is formed into an uneven shape on the outer circumference and the inner circumference, formed into an annular shape, and surrounded by a resin.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotor for a wheel rotation sensor such as an anti-lock brake system, and more particularly to an improvement of a magnetic rotation sensor configured by using a metal magnetic material.

[0002]

[Prior art]

 Conventionally, rotation detection of a wheel used in an automobile anti-lock brake system or the like is performed by a metallic rotation sensor rotor 5 having only unevenness or a gear shape on its outer periphery as shown in FIG. In the example, in the rotation speed sensor, an electromagnetic pickup is provided opposite to the rotor 5 for the rotation sensor, the change in magnetic flux density due to the rotation of the rotor 5 for the rotation sensor is detected by the electromagnetic pickup, and the pulse signal synchronized with the rotation speed is detected. The rotation is detected by outputting as. However, the product obtained by this conventional method is heavier by the thickness of the inner peripheral surface A of the metal formed into a flat circular shape, and when the rotor 5 for the rotation sensor is further exposed, the excellent rust prevention effect is obtained. Therefore, there is a disadvantage that a special surface treatment is required even in the processing step, and the cost becomes high. Further, as shown in FIG. 5, there is a conventional method in which the iron pieces 7 are embedded at equal intervals on the outer periphery of the rotation sensor rotor 6 formed of resin 8 to detect rotation, but with the iron piece 7, the rotation sensor rotor 6 is used. The iron piece 7 in the rotor 6 for the rotation sensor becomes large against the magnetic force at the time of detection required for the above, and the weight cannot be reduced. Further, the same excellent rust prevention effect as the conventional method is required. . The above-mentioned drawbacks can be cited.

[0003]

[Problems to be solved by the device]

 Therefore, the problem to be solved by the present invention is to solve the above-mentioned drawbacks, it is small and has a strong magnetic force, it is possible to detect the pulse signal at the time of detection more accurately, and it is also lightweight and has improved rust prevention. And to provide a rotation sensor rotor at a lower cost.

[0004]

In order to solve the above problems, according to the present invention, a rotor for a rotation sensor 1 which has conventionally been provided with an uneven or toothed shape only on the outer circumference is provided with an outer circumference and an inner circumference of a thin metal magnetic body 2. The rotation sensor rotor 1 is made thin by forming the circumference to have an uneven shape, and the circumference thereof is surrounded by a synthetic resin 3.

[0005]

[Action]

 The present invention is a hub in which a rotor 1 for a rotation sensor, which is formed by annularly forming a thin and thin metal magnetic body 2 on its outer and inner circumferences and is surrounded by a synthetic resin 3, is provided on an axle (drive shaft) 10. Press into 11 and fix. As a result, the rotation sensor rotor 1 rotates together with the axle (drive shaft) 10 and is synchronized with the rotation of the axle (drive shaft) 10 by the electromagnetic pickup 9 provided at a constant distance from the rotation sensor rotor 1. The generated electromotive force is generated and output as a pulse signal to detect rotation.

[0006]

【Example】

 The present invention will be described below with reference to the drawings.

First Embodiment FIG. 1 is a partial perspective view showing a rotor 1 for a rotation sensor used in the present invention as a first embodiment, and FIG. 2 is a front view showing the rotor 1 for a rotation sensor. It is a thing. In the first embodiment, the rotor 1 for a rotation sensor has a metal magnetic body 2 made of a steel plate made of SPCC material, which is formed into an uneven shape by press working, and is further formed into a ring shape. Enclose with polyphenylene sulfide resin. In this case, the molding method is as follows. First, the outer diameter of the metal magnetic body 2 formed into the concavo-convex shape is fixed in the mold and the synthetic resin 3 (fiber reinforced resin) is injected to form the inner diameter and the end surface. Further, in the next second step, contrary to the first step, the inner diameter of the metal magnetic body 2 is fixed in the mold, and the synthetic resin 3 (fiber reinforced resin) is injected to the outer diameter and the first step. Molded the opposite end face. The above means is used.

Second Embodiment FIG. 3 is a front view of a rotation sensor rotor 21 according to a second embodiment. In the second embodiment, the inner circumference of the rotation sensor rotor 21 based on the first embodiment is shown. At least, insert-mold the steel ring 4 made of SPCC material.

Usage Example 1 FIG. 6 is a partial cross-sectional front view showing a usage example of the rotor 1 for a rotation sensor formed in the first and second embodiments. Shaft 11 is press-fitted into a hub 11 and rotates together with an axle (drive shaft) 10, and a magnetic field is created by a magnet in an electromagnetic pickup 9 provided in the vicinity of the rotation sensor rotor 1. The electromotive force is generated in the electric wire in the coil by the movement of the magnetic metal 2 as a conductor in the magnetic field (Faraday's law of electromagnetic induction). In addition, the electromotive force changes the distance B from the rotational speed sensor 9 due to the unevenness of the metal magnetic body 2 according to Lenz's law. Therefore, the electromotive force increases or decreases and is output as a pulse signal, so that the rotational speed can be detected.

[0010]

[Effect of device]

 In the present invention, since the outer and inner circumferences of the thin plate-shaped metal magnetic body 2 are formed in a concavo-convex shape in the first and second embodiments, the thickness is thin, so that the weight can be reduced as compared with the conventional example 1, and thus the cost It can also be reduced. In addition, since the metal magnetic body 2 is surrounded by the resin 3 so as to have a great rust preventive force, the working process can be simplified, mass productivity can be improved, and the manufacturing cost can be reduced. Furthermore, the annular metal magnetic body 2 in the embodiment of the present invention forms a discontinuity in which a number of iron pieces 7 are embedded in the outer periphery of the rotation sensor rotor 6 at regular intervals, as shown in FIG. Compared to the above, since the magnetization energy is stronger and the magnetic flux also increases, the electromotive force as described in Use Example 1 becomes higher, and by outputting a highly accurate pulse signal that is not affected by noise, rotation can be detected more accurately. It is possible. In the second embodiment, by providing the steel ring 4 on the inner circumference of the rotation sensor rotor 21, it is possible to improve the strength against a pressure input during mounting.

[Brief description of drawings]

FIG. 1 is a partial perspective view showing a first embodiment of the present invention.

FIG. 2 is a front view showing the first embodiment of the present invention.

FIG. 3 is a front view showing a second embodiment of the present invention.

FIG. 4 is a partial front view showing Conventional Example 1 of the present invention.

FIG. 5 is a partial front view showing a second conventional example of the present invention.

FIG. 6 is a partially sectional front view showing an example of use of the present invention.

FIG. 7 is a partial front view showing an example of use of the present invention.

[Explanation of symbols]

 1 ... Rotation sensor rotor 2 ... Metal magnetic body 3 ... Resin 21 ... Rotation sensor rotor 4 ... Steel ring 5 ... Rotation sensor rotor 6 ... Rotation sensor Rotor 7 ... Iron piece 8 ... Resin 9 ... Electromagnetic pickup 10 ... Axle (drive shaft) 11 ... Hub A ... Inner peripheral surface B ... Distance to rotor for rotation sensor

Claims (2)

[Scope of utility model registration request] 1. A rotor 1 for a rotation sensor, characterized in that an outer periphery and an inner periphery of a thin plate-shaped metal magnetic body 2 are formed in an uneven shape. 2. The rotor 1 for a rotation sensor according to claim 1, wherein the thin plate-shaped metal magnetic body 2 is surrounded by a synthetic resin 3.