JPH09308211A - Actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the weight of a body, calorific value and manufacturing man-hour by using at least one of two magnetic resistance sections to couple two magnetic pole pieces, as a high magnetic resistance section where magnetic saturation takes place when the actuator is in operation, and placing a separate cylindrical magnetic path for the coupling magnetic path. SOLUTION: An actuator body 1 is mechanically integrated with magnetic pole pieces 2, 3 with auxiliary air gaps 11-1, 11-2 having a small cross-sectional area in-between. A core is shaped into a cylinder, and is made of members 12a, 12b separate from the body with an air gap 13 in-between. Thus, the operation of the actuator is characterized in that the auxiliary air gaps 11-1, 11-2 integrally cause magnetic saturation and thus the actuator is provided with a function as magnetic resistance, and that magnetic energy is stored in the air gap 13 and thus the actuator is provided with a spring function. Since the core is cylindrical and made of separate members, electromagnetic coils require less wires and calorific value is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator for a throttle that can control its position according to a coil current without a spring.

[0002]

2. Description of the Related Art A throttle actuator needs to move a moving body (for example, a rotor) according to a driving force (a magnetomotive force source) according to the magnitude of a current. Generally, in this type of technique, the rotor is stopped by using a spring that generates a reaction force proportional to the rotor position, but the applicant has proposed an actuator that does not require a spring, for example, Japanese Patent Application No. 7-56686. (Referred to as prior art) has already been proposed.

An outline of the prior art will be described with reference to FIG. In FIG. 4, the actuator body 1 is formed of a symmetrical yoke member and has two magnetic pole pieces 2 and 3 and connecting members 4a and 4b. A main air gap 5 is provided between the magnetic pole pieces 2 and 3, and sub air gaps 6-1 and 6-2 are provided on both sides of the main air gap.

A rotor 7 made of a permanent magnet is arranged in the main air gap 5 and is configured to rotate via a shaft 8. Reference numeral 9 is an electromagnetic coil (magnetomotive force source).
Therefore, when the electromagnetic coil 9 is not energized, the magnetic flux emitted from the N pole of the rotor returns to the S pole via a part of the magnetic pole pieces 2 and 3 on both sides, and stops at the position shown in the figure to stabilize. The state is maintained.

When the electromagnetic coil 9 is energized, the magnetomotive force generated here is generated in the main air gap 5 and the sub air gaps 6-1 and 6-2, which are magnetic resistances in the magnetic path, and in the magnetic resistance gap 10. And the rotor 7 stops at a position where these energies are minimized. Then, the energy stored here becomes a source of reaction force and functions like a spring. These have been fully explained in the prior art.

[0006]

In the case of the above device, FIG.
As shown in the side view of (b), the yoke members are laminated, and as can be seen from FIG. 4 (a), the electromagnetic coil 9 provided at the connecting portion must be rectangular.

When the electromagnetic coil has a rectangular shape, more wire is required to obtain the same magnetomotive force than in the case of a cylindrical coil, which increases not only the weight but also the amount of heat generation. Also, the number of man-hours for adjusting the coaxiality of the magnetic pole pieces 2 and 3 and the rotor 7 and the air gap 10 by the two yoke members becomes a problem.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an actuator for a throttle in which the weight of the main body is reduced, the heat generation amount is reduced, and the number of manufacturing steps is reduced.

[0009]

An actuator according to [Claim 1] of the present invention has two magnetoresistive portions on both sides of a main air gap to form two opposing pole pieces.
A magnetic resistance is provided in a magnetic path that magnetically connects the two magnetic pole pieces, a magnetomotive force source made of a coil is provided in the connection magnetic path position, and a permanent magnet that rotates integrally with the drive shaft is provided in the main air gap. In the actuator provided with the rotor, the at least one of the two magnetoresistive portions is
The two magnetic pole pieces are connected as a high magnetic resistance portion in which magnetic saturation occurs when the actuator operates, and a separate cylindrical magnetic path (core) is provided in the connecting magnetic path.

The actuator according to [Claim 2] of the present invention is the same as [Claim 1], except that instead of the cylindrical magnetic path which is a separate body, the whole is made into one cylindrical magnetic path. A magnetic resistance was provided between at least one side surface of the magnetic path (core) and the side surface of the magnetic path connected to the magnetic pole piece.

In the actuator according to [Claim 3] of the present invention, one of the two magnetoresistive portions is an air gap in [Claim 1] or [Claim 2].

[0012]

FIG. 1 is a block diagram showing an embodiment of an actuator according to [claim 1]. In FIG. 1, the same functional portions as those in FIG. 4 are designated by the same reference numerals and the description thereof will be omitted. First, the main body 1 is the sub air gap 11-
1, 11-2 have a narrow cross-sectional area and are mechanically integrated with the magnetic pole pieces 2, 3.

This is because magnetic saturation occurs when the actuator operates. In addition, the core 12 is formed in a cylindrical shape into separate bodies 12a and 12b, and an air gap 13 is provided between them.

Therefore, as an operation, the sub air gap 11
-1, 11-2 integrally function as a magnetic resistance by causing magnetic saturation, and the air gap 1
The magnetic energy is stored in 3 to have a spring function, and the action of the actuator itself is as shown in the conventional example.

According to the present embodiment, since the core is formed as a cylindrical separate body, not only the number of wires of the electromagnetic coil is small, but also the amount of heat generated is reduced, and the main body is integrated. Manufacturing man-hours and adjustment become easy.

FIG. 2 is a configuration diagram showing an embodiment of an actuator according to [claim 2]. In FIG. 2, FIG.
The same functional parts as in FIG.

The characteristic feature of FIG. 2 is that the magnetic path (core) 14 to be connected is made into a cylindrical shape and one side surface of this cylindrical magnetic path (core) is connected to the magnetic pole piece. An air gap 13-1 is provided between the side surface and the side surface. The operation of this embodiment is substantially the same as that of FIG. 1, and as a result, the same effect is obtained.

FIG. 3 is a configuration diagram showing an embodiment of an actuator according to [claim 3]. In FIG. 3, FIG.
The same functional parts as in FIG.

The characteristic feature of the present embodiment is that one of the two magnetoresistive portions is used as the air gap 14, and the other points are the same as in FIG. According to the present embodiment, the same effect as that of FIG. 1 can be obtained.

[0020]

As described above, according to the present invention, 2
Since a magnetic pole (yoke) is integrally formed via two high magnetic resistance portions, a cylindrical core is inserted at the connection position of the yoke members, and a magnetomotive force source consisting of a coil is provided at this position, the main body At the same time, the amount of heat generated was reduced, and the number of manufacturing steps and adjustments were reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an actuator according to [claim 1] of the present invention.

FIG. 2 is a configuration diagram showing an embodiment of an actuator according to [claim 2] of the present invention.

FIG. 3 is a configuration diagram showing an embodiment of an actuator according to [claim 3] of the present invention.

FIG. 4 is a diagram showing a conventional device.

[Explanation of reference numerals] 1 main body 2,3 magnetic pole pieces 4a, 4b connecting member 5 main air gap 6-1, 6-2 sub air gap 7 rotor 8 shaft 9 electromagnetic coil 10, 13, 14 air gap 11-1, 11-2 High magnetic resistance part 12 cores

Claims (3)

[Claims] 1. A pair of magnetic pole pieces facing each other having two magnetic resistance portions on both sides of a main air gap are formed, and a magnetic resistance is provided in a magnetic path magnetically connecting the two magnetic pole pieces, In an actuator in which a magnetomotive force source made of a coil is provided at the connection magnetic path position and a rotor made of a permanent magnet that rotates integrally with the drive shaft is provided in the main air gap, at least one of the two magnetic resistance portions is An actuator characterized in that the two magnetic pole pieces are connected as a high magnetic resistance portion in which magnetic saturation occurs when the actuator operates, and the connecting magnetic path including a magnetomotive force source has a separate structure. 2. The actuator according to claim 1, wherein a magnetic resistance is formed between at least one side surface of the separate connecting portion and a magnetic path side surface connected to the magnetic pole piece. 3. The actuator according to claim 1, wherein one of the two magnetic resistance portions is an air gap.