JPH0510712A - Rotary sensor - Google Patents

Abstract

PURPOSE:To realize the thinning and miniaturization of a rotary sensor. CONSTITUTION:A base plate integrated form base member 12 serving both as a first support member whose purpose is to fit a magnetic detection element 7, and a second support member whose purpose is to fit a circuit constitution component 10, is prepared. And the magnetic detection element 7 and the rotation constitution member 10 are commonly fitted to a member 12 surface opposite to a motor main body 3. As a result, thickness of a rotary sensor in the rotary shaft direction can be made small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation sensor used for detecting the rotational speed and rotational position of a rotating body such as an output shaft of various engines and rotating shafts of various motors.

[0002]

2. Description of the Related Art When detecting the number of rotations or the rotational position of a rotating body, for example, a change in magnetism is detected by a magnetic detection element such as an MR element or a Hall element, converted into an electric signal and output. ing.

FIG. 4 shows such a detection principle.
At least one pair of magnetic poles N and S are arranged on the outer peripheral surface of the cylindrical rotating body, for example, the magnetic drum 1, and the magnetic detecting element 7 is arranged via the magnetic pole surface and a predetermined gap G. The rotating shaft 2 of the magnetic drum 1 is coupled to a rotating shaft of a motor (not shown) or the like, and when the magnetic drum 1 starts rotating, the magnetic poles N, S
The magnetism generated from the changes.

This change in magnetism is detected by the magnetic detecting element 7, which is converted into an electric signal and a substantially sinusoidal signal as shown in FIG. 5 is output. The output signal is subjected to signal processing to detect the rotation speed and rotation position of the motor based on the signal processing.

FIG. 3 is a sectional view showing the structure of a conventional rotation sensor. Reference numeral 1 is a magnetic drum having a large diameter portion 1A and a small diameter portion 1B, and the outer peripheral surface of the large diameter portion 1A is as shown in FIG. At least one pair of magnetic poles N and S are arranged in the shaft, and the rotary shaft 5 of the motor main body 3 is fitted into the through hole 8 provided in the central portion thereof so that the rotational force is transmitted from the motor main body 3. Is configured. Reference numeral 4 denotes a base member which is mounted around a small diameter portion 1B of the magnetic drum 1 via a slide bearing 6, and is arranged at a desired position on one surface of the base member 4 so as to face the magnetic pole surface of the large diameter portion 1A of the magnetic drum 1. The magnetic detection element 7 is attached so that

A circuit board 9 is mounted on the other surface of the base member 4, on which circuit components 10 necessary for operating the rotation sensor are mounted. Reference numeral 11 denotes a damper spring mounted between the motor main body 3 and the base member 4 so that even if the runout of the rotating shaft 5 occurs, the damper spring 11 is made to follow the runout so that the distance between the magnetic drum 1 and the magnetic detecting element 7 is always constant. It is used for holding and consists of coil springs or leaf springs. The circuit board 9
Is attached to the base member 4 by adhesion, screwing, or the like.

[0007]

By the way, in the conventional rotation sensor, the base member 4 for mounting the magnetic detecting element 7 and the circuit board 9 for mounting the circuit component 10 are used and arranged. However, there is a problem that it is difficult to reduce the size and size in the direction of the rotation axis.

That is, two kinds of members 4 and 9 are stacked in the direction of the rotation axis, and the circuit component 10 is further mounted on the circuit board 9.
As a result, the thickness dimension in the direction of the rotation axis is unavoidably increased. In addition, an extra step for attaching the circuit board 9 to the base member 4 is required.

The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a rotation sensor which can be made thinner and smaller in the rotation axis direction.

[0010]

In order to achieve the above object, the present invention provides a rotating body attached to a rotating shaft of a rotating source,
In a rotation sensor having at least a detection element that is arranged so as to face the surface of the rotating body through a predetermined gap and detects a rotation amount and outputs an electric signal corresponding to the rotation amount, the rotation source is provided along the rotation axis. Is provided around the rotating body at a position on the opposite side via a bearing, and is provided with a plate-shaped supporting member to which the detection element and the circuit component are commonly attached at this predetermined position. .

[0011]

The plate-like support member, to which the detection element and the circuit component are commonly attached, is arranged around the rotating body on the side opposite to the rotation source along the rotation axis via the bearing. As a result, it is not necessary to separately prepare members for mounting the detection element and the circuit component, respectively, so that the rotation sensor can be made thin and small.

[0012]

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

FIG. 1 is a sectional view showing an embodiment of a rotation sensor of the present invention. A magnetic drum 1 has a large diameter portion 1A and a small diameter portion 1B, and a concave portion 1C is formed inside the large diameter portion 1A. There is.
At least one pair of magnetic poles N and S are arranged on the outer peripheral surface of the large-diameter portion 1A of the magnetic drum 1 as shown in FIG. The rotary shaft 5 of 3 is fitted in, and the rotational force is transmitted from the motor main body 3.

Reference numeral 12 denotes a substrate-integrated base member made of, for example, aluminum having excellent heat dissipation properties, and is located at a position along the rotating shaft 5 opposite to the motor main body 3 and the magnetic drum 1 is provided.
Is attached to the periphery of the bearing via a slide bearing 6. In this case, the end portion of the sliding bearing 6 is arranged so as to partially face the concave portion 1C inside the large diameter portion 1A of the magnetic drum 1.

At a desired position on the surface of the substrate-integrated base member 12 facing the motor main body 3, the magnetic detecting element 7 is disposed so as to face the magnetic pole surface of the large diameter portion 1A of the magnetic drum 1.
Is installed. The circuit component 10 is mounted at another position on the same surface. FIG. 2 shows an outline of the bottom structure of the substrate-integrated base member 12, which is a circuit component 10 (P1, P2, necessary for operating the rotation sensor).
P3, ...) Are mounted in an arbitrary arrangement. As the circuit component 10, an electronic component such as a diode including a resistor, a capacitor, an inductor, a transistor, and an IC is used.

Reference numeral 11 denotes a damper spring mounted between the motor main body 3 and the base member 4 so that even if a runout of the rotating shaft 5 occurs, the damper spring is made to follow the runout, so that the distance between the magnetic drum 1 and the magnetic detecting element 7 is increased. It is used to keep constant, and consists of coil springs and leaf springs.

Next, the operation of this embodiment will be described.

A substrate-integrated base member 12, which also serves as a first supporting member for mounting the detecting element and a second supporting member for mounting the circuit component, is used, and the motor main body 3 is provided along the rotary shaft 5. Is mounted around the magnetic drum 1 at a position on the opposite side via a slide bearing 6.

The magnetic detection element 7 and the circuit component 10 are commonly attached to the surface of the substrate-integrated base member 12 facing the motor body 3.

According to the structure of this embodiment, it is not necessary to separately prepare and stack the base member for mounting the magnetic detecting element 7 and the circuit board for mounting the circuit component 10 as in the conventional case. Since the magnetic detection element 7 and the circuit component 10 are commonly attached by using the substrate-integrated base member 12 which also has the functions of both members, the thickness dimension in the rotation axis direction can be reduced. Therefore, the rotation sensor can be made thinner and smaller in the rotation axis direction.

Further, by using a member having excellent heat dissipation property such as aluminum as the substrate-integrated base member 12, the heat generated in a large number of circuit components 10 can be quickly dissipated.

Further, by using the substrate-integrated base member 12, the circuit board 9 is connected to the base member 4 as in the conventional case.
Since an extra step for mounting the device is unnecessary, work such as bonding or screwing can be omitted, and the number of steps does not increase.

[0023]

As described above, according to the present invention, a plate-like support member having a function of mounting a magnetic detection element and a circuit component is used, and the magnetic detection element and the circuit component are commonly mounted on this support member. Since the rotation sensor is attached to, the rotation sensor can be made thinner and smaller in the rotation axis direction.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a rotation sensor of the present invention.

FIG. 2 is a bottom view showing a plate-shaped support member used in the rotation sensor of this embodiment.

FIG. 3 is a cross-sectional view showing a conventional sensor.

FIG. 4 is an explanatory diagram of the principle of magnetic detection.

FIG. 5 is a signal waveform diagram output from the magnetic detection element.

[Explanation of symbols]

1 magnetic drum 7 Magnetic detection element 10 Circuit components 12 Base material with integrated board

Claims (3)

[Claims] 1. A rotating body attached to a rotating shaft of a rotating source, and a detecting element which is arranged so as to face the surface of the rotating body through a predetermined gap and detects a rotation amount and outputs an electric signal corresponding thereto. In a rotation sensor having at least
A plate-like support member is arranged around the rotary body at a position opposite to the rotation source along the rotary shaft via a bearing, and the detection element and the circuit component are commonly attached to the predetermined position. A rotation sensor characterized by being provided. 2. The plate-shaped supporting member comprises a first supporting member for mounting a detection element and a second supporting member for mounting a circuit component, which are integrated with each other. Rotation sensor. 3. The rotation sensor according to claim 1, wherein the detection element and the circuit component are mounted on a surface of the plate-shaped support member facing the rotation source.