JPH07191048A - Revolutions sensor device - Google Patents

Abstract

PURPOSE:To enable a revolutions sensor device to change the number of signal pulses per one revolution by only changing the fitting state of a sensor. CONSTITUTION:A revolutions sensor device is constituted by combining a gear 10 having different numbers of teeth depending upon positions in the direction of its rotating shaft and a sensor section 12 the detecting section 11 of which is deviated from the center axis of the section 12. Since the sensor section 12 is fitted by turning the section 12 against the center axis of a sensor, the number of teeth to be detected is switched and the number of signal pulses per one rotation can be easily changed without changing parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotational speed sensor device for detecting rotational displacement using an electromagnetic circuit.

[0002]

2. Description of the Related Art In recent years, a non-contact type detection device has been strongly demanded as a rotation speed sensor device having a long life and high reliability. Among several methods that strongly realize the non-contact type detection device, the magnetic type device has the advantages of excellent environmental resistance and relatively low cost. Has been applied to various uses.

A magnetic type rotation speed sensor device will be described below with reference to the drawings. FIG. 4 is a cross-sectional view of a prime mover such as a vehicle. In FIG. 4, reference numeral 1 denotes a prime mover portion for driving a vehicle or the like, and has a gear 3 for driving wheels at an end portion of the prime mover portion 1 where a prime mover shaft 2 extends. Reference numeral 4 denotes a sensor portion provided on the outer end surface of the gear 3 in the circumferential direction, which detects the rotation speed of the gear 3 to detect the speed of the vehicle or the like.

A conventional magnetic rotation speed sensor device will be described below with reference to the drawings. FIG. 5 is a partial cross-sectional view of a conventional magnetic rotation detection device. In FIG. 5, reference numeral 5 denotes a gear which has an uneven portion 6 to be detected in the circumferential direction and which is provided at an end portion of an engine shaft of a prime mover or the like. Reference numeral 7 denotes a sensor portion, which has a magnet 8 inside and a detection portion 9 at the end portion not in contact with the detection target portion 6 in the diametrical direction of the gear 5.

The operation of the conventional magnetic rotation speed sensor device constructed as described above will be described.

By detecting the magnetic field generated by the magnet 8 inside the sensor unit 7 by the detecting unit 9 of the sensor unit 7 by detecting the magnetic field change which changes with the movement of the position of the concave and convex detected portion of the gear 5. , An electric signal corresponding to the rotation state of the gear 5 was obtained.

[0007]

However, in the above-mentioned conventional configuration, the number of signal pulses for one rotation of the gear 5 is
Since the detected part 6 has only one pattern of unevenness, it is set to a certain value. Therefore, when the number of signal pulses per rotation of the gear 5 is changed in order to distinguish the type of product or the application, the gear itself must be replaced with one having a desired change in the number of rotations. There was a problem that the complexity of management and the design on the premise of incorporating various kinds of gears were required.

The present invention solves the above-mentioned conventional problems and provides a rotation speed sensor device in which the number of signal pulses per rotation can be easily changed only by changing the mounting state of the sensor section. Is.

[0009]

In order to solve this problem, a rotation speed sensor device according to the present invention comprises a rotating body which rotates together with a rotating shaft, and a plurality of rows to be detected provided on the outer circumferential surface of the rotating body. And a sensor section for detecting at least one row of the detected section at a position that does not contact the detected section in the circumferential direction of the rotating body, and the sensor section detects any one row of the detected sections. It has a fixing means for positioning and fixing.

[0010]

The rotation speed sensor device according to the present invention has one part depending on the part.
By changing the mounting position of the sensor part by combining the gear with different number of teeth per rotation and the sensor part where the detection part is eccentric, the number of teeth of the detected part to be detected changes. The number of signal pulses per rotation can be easily changed without replacement.

[0011]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial sectional view of a rotation speed sensor device according to an embodiment of the present invention. The same parts as those in the conventional technique are designated by the same reference numerals, and detailed description thereof will be omitted. In FIG. 1, reference numeral 10 denotes a gear of a magnetic metal rotating body having a plurality of rows of concave and convex portions to be detected 11 on the outer circumferential surface in the circumferential direction and provided at the end of an engine shaft of a prime mover or the like. . Reference numeral 12 denotes a sensor unit mounted on a casing 13 of the transmission that shifts the rotation of the prime mover with a screw 15 via a ring 14 of a wheel. The sensor unit 12 has a magnet 7 inside and a rotating shaft 1 of the gear 10.
A detection unit 8 for detecting at least one row of the detection target portions 11 is provided at a position not contacting the detection target portions 11 in the diametrical direction.

FIG. 2 is a partial sectional view taken along line XY of FIG. In FIG. 2, reference numeral 17 is a fixing means for housing the sensor unit 12 and fixing it to the housing 13. Reference numeral 18 is a detection point of the detection unit 8 provided in the sensor unit 12. The detection point 18 is provided at a position displaced from the central axis 16 by a length L. 10 is a gear, the first groove 21 and the second groove 2
The second and third grooves 23 are provided. In the cross section of the first groove 21, the second groove 22, and the third groove 23 of the gear 10,
The number of teeth differs by A / 2, A, 2A (A is an arbitrary constant). Therefore, the detection point 1 of the sensor unit 12
The number of signal pulses per rotation is respectively A
/ 2, A, 2A can be changed.

In addition to the method of moving the fixing means 17 in the rotation axis direction of the gear 10 when switching the number of pulses, the fixing means 17 can be set by setting L shown in FIG. 2 to an appropriate length. By mounting the fixing means 17 by rotating it by a certain angle with respect to the central axis 16, the detection point 18 can be moved, and the same effect can be obtained. With this method,
The number of holes 19 and 20 for attaching the fixing means 17 may be one, and a sealing structure using the ring 14 or the like can be easily realized.

(Embodiment 2) Another embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a partial sectional view showing the structure of a rotation speed sensor device according to another embodiment of the present invention. The same parts as those in the conventional technique are designated by the same reference numerals, and detailed description thereof will be omitted. In FIG. 3, reference numeral 21 denotes a plurality of rows of concave and convex first and second detected parts 22 and 23 having different diameters with respect to the circumference on the outer circumferential surface in the circumferential direction. It is a gear provided at the end of the engine shaft. 12 is a sensor unit. The sensor unit 12 has a magnet (not shown) inside, and a detection unit (not shown) that detects the detection target 22 at a position not in contact with the detection target 22 in the diameter direction of the rotation axis of the gear 21. )have.

With this configuration, the sensor section 12 has a distance G between the detection section and the detected surface 22 of the gear 21 to be detected,
When the distance between the rotation axis (not shown) of the gear 21 and the sensor detection surface is X and the first detection surface 22 of the gear 21 is R1, the relational expression of “X ≦ R1 + G” is satisfied, and The detected part 22 of is detected.

On the other hand, when the distance X between the rotation axis of the gear 21 and the sensor detection surface is "R1 + G≤X≤R2 + G", the sensor section 12 can detect the teeth of height R1-R0. No, only the teeth of height R2-R0 are detected.

That is, by changing the air gap between the sensor portion 21 and the gear 21, it becomes possible to switch the signal pulse per rotation. The change of the air gap can be easily realized by a method of sandwiching a spacer in the mounting portion of the sensor unit 12.

In each of the first and second embodiments, the case where the number of signal pulses is reduced by half has been shown, but it is possible to combine various signal pulse numbers by changing the shape of the gear. Needless to say.

[0021]

As described above, according to the present invention, a gear-like rotating body having different numbers of teeth in the cross section when the cross-sectional position in the plane perpendicular to the rotation axis is different, and the center of the detection end surface. By combining with a magnetic sensor for detecting the irregularities of the rotating body, which has a detecting portion at a position deviated from the position, the number of signal pulses per one rotation of the rotating body can be determined without changing the components. The present invention realizes an excellent rotation speed sensor device that can be switched only by itself.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a rotation speed sensor device according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view taken along the same XY direction.

FIG. 3 is a partial cross-sectional view of a rotation speed sensor device according to another embodiment of the present invention.

FIG. 4 is a sectional view of a rotation speed sensor device.

FIG. 5 is a partial cross-sectional view of a conventional rotation speed sensor device.

[Explanation of symbols]

 10 Gear 11 Detected Part 12 Sensor Part 17 Fixing Means

Claims (4)

[Claims] 1. A rotating body that rotates with a rotating shaft, a plurality of rows of detected parts provided on the outer circumferential surface of the rotating body, and a position that does not contact the detected part in the circumferential direction of the rotating body. A rotation speed sensor device, comprising: a sensor unit that detects at least one row of the detected portion; and a fixing unit that positions and fixes the sensor portion so as to detect any one row of the detected portions. 2. The detected parts having different distances from the central axis of the rotating body to the outer circumferential surface are provided.
The rotation speed sensor device described. 3. A transmission housing, a transmission having a gear and a rotation shaft inside the transmission housing, a rotating body that rotates with the gear in the transmission, and a circumference or an end surface of the rotating body. A plurality of concentrically provided detection sections, a sensor section that detects at least one row of the detection sections at a position that does not contact the detection section in the circumferential direction of the rotating body, and the sensor section is housed. And a fixing unit for fixing the fixing unit to the transmission casing so as to eccentrically detect the detection point of the sensor unit. 4. A rotating body made of magnetic metal, a plurality of rows of detected portions provided on the outer circumferential surface of the rotating body, and the portion of the rotating body which is not in contact with the detected portion in the circumferential direction. 4. The rotation speed sensor device according to claim 1, further comprising a sensor unit that magnetically detects at least one row of the detection unit.