JPH0951663A - Reciprocal linear motion actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a return spring by setting the distance between adjacent poles of a stator equal to the distance between adjacent different poles of a mover and shifting the center of each pole of the mover, at the dead point thereof, axially from the center of corresponding pole of the stator. SOLUTION: When the number of poles (n) of a stator 2 is 2, i.e., in the case of two poles, a mover 9 comprising a permanent rod magnet sequentially magnetized with (n+1), i.e., 3, different poles of N, S, N poles in the axial direction is employed as a plunger. Stoppers 7 are disposed at the dead points of axial reciprocation of the mover 9 and the interpole distance of the stator 2 is matched with the interpole distance of adjacent N and S poles of the mover 9. At the dead points of axial reciprocation of the mover 9, the center of each pole of the mover 9 is shifted axially from the center of facing pole of the stator 2. A permanent magnet bearing having inner surface magnetized with same polarity as the corresponding pole of the mover 9 is employed as the bearing 6 for the mover 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating linear motion actuator, and more particularly to a reciprocating linear motion actuator used for a pachinko ball.

[0002]

2. Description of the Related Art Generally, there are a motor type, a rotary actuator type, and a linear movement solenoid type as reciprocating linear motion actuators that provide a reciprocating motion force for hitting a pachinko machine.

In the motor type, a return spring is wound by a cam and then released to obtain a hitting force.

In the rotary actuator type, a striking force is obtained by a rotating torque, and a return spring returns it to a fixed position.

In the linear solenoid type, a striking force is obtained by a plunger attraction force, and a return spring returns it to a fixed position.

FIG. 14 shows a conventional linear motion solenoid type actuator. Reference numerals 1 and 2 denote outer and inner circumferential stators, respectively.
Reference numeral 3 is a stator winding wound around the inner peripheral stator 2, 4 is a rotor shaft extending through the stators 1 and 2, and 5 is a plunger connected to one end of the rotor shaft 4. 6 is a bearing for movably supporting the mover shaft 4 and the plunger 5 in the axial direction, 7 is a stopper fixed to the tip of the mover shaft 4 and the rear end of the plunger 5, and 8 is a stator. 1 is a return spring inserted between the end surface of the stopper 1 and one side surface of the stopper 7.

[0007]

However, in the above-mentioned motor type and rotary actuator type, the striking point is not stable because the distance between the shaft center and the striking point is large due to the circular arc motion. There is also a problem of the settling of the return spring.

The linear solenoid type has a problem that the life of the slide bearing is short in addition to the settling of the return spring.

The present invention has been made to eliminate the above disadvantages.

[0010]

The reciprocating linear motion actuator of the present invention is excited by alternating currents of positive and negative polarities n (n is 2).
Or an integer greater than or equal to 2) poles, a mover magnetized to n + 1 different poles, and a stopper for the mover arranged at the dead center position of the reciprocating movement of the mover. The distance between the adjacent poles of the stator is equal to the distance between the adjacent different poles of the mover, and the center of each magnetic pole of the mover at the dead center position of the mover corresponds to each pole of the stator. It is axially displaced from the center of.

The moving element is movably supported by a bearing of a permanent magnet, and the inner surface of the permanent magnet is magnetized to have the same polarity as that of the corresponding portion of the moving element.

The bearing of the permanent magnet supports either the lower surface or the upper and lower surfaces of the moving element.

The supporting surface of the moving element by the bearing of the permanent magnet is either a flat surface or a curved surface.

The bearing of the permanent magnet is an annular body surrounding the moving body, and its cross section is either circular, oval or prismatic.

In the reciprocating linear motion actuator of the present invention, since the reciprocating linear motion is magnetically performed without using the spring, the problem of the settling of the spring and the hitting point becoming unstable can be solved.

Further, since it is a magnetic levitation bearing, there is little friction, and since there is no sliding portion, the problem of bearing life can be relieved.

[0017]

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

In the present invention, as shown in FIG. 1, when the number of magnetic poles of the stator 2 is n (n is 2 or an integer of 2 or more), for example, 2 poles, n + 1 are sequentially axially used as a plunger.
A mover 9 composed of rod-shaped permanent magnets magnetized to have different poles, for example, N, S, and N poles, and three poles is used, and stoppers 7 and 7 are arranged at the axially reciprocating dead center positions of the mover 9, respectively. , The distance between the poles of the stator 2 is made to match the distance between the adjacent N and S magnetic poles of the mover 9.

At the dead center position of the reciprocating movement of the moving element 9, the center of each magnetic pole of the moving element 9 is axially displaced from the pole center of the stator 2 facing the moving element.

As the bearing 6 of the moving element 9, as shown in FIG. 2, a bearing of a permanent magnet whose inner surface is magnetized to have the same polarity as the magnetic pole of the corresponding moving element 9 is used.

Incidentally, the bearing 6 of the permanent magnet may have a circular, oval or prismatic cross section corresponding to the moving element 9, and the lower surface or the upper and lower surfaces of the moving element 9 may be flat or curved. You may make it support by the support surface of.

Further, the stator winding 3 is a single winding (unifilar winding) or a multiple winding (bifilar winding).
Can be done.

FIG. 3 shows the relationship between the time t and the drive current flowing through the stator winding 3, where A is the non-excitation state, B is the (+) excitation state, and C is the (-) excitation state.

4 to 6 are explanatory views of the positional relationship between the stator and the moving element and the moving force in the reciprocating linear motion actuator of the present invention with respect to FIG. 2, and FIG. 4 is the moving element in the non-excitation state. Holding force T _D and its direction, FIG. 5 is a holding force T _H when the stator is excited and its direction, and FIG. 6 is a holding force T _D and T _D.
The resultant force T _{T of H} and its direction are shown.

7 to 13 are explanatory views of the relationship between the set positions of the mover and the stopper with respect to the stator and the holding forces T _D and T _T during the hold to move of the mover.

The magnitude and direction of the holding force represent the magnitude and direction of the force when the center S pole of the three poles of the mover is displaced.

[0027]

As described above, according to the reciprocating linear motion actuator of the present invention, the moving element can be held in the non-energized state at the dead center positions thereof without using the spring for restoration. Further, due to the deviation of the magnetic poles of the stator pole and the mover, moving torque in the direction of deviation is generated, no return spring is required, and the polarity and timing of the drive current flowing through the stator winding 3 are arbitrarily selected. The mover can be driven very easily, and its hold position can be set arbitrarily.

Further, since the mover and the bearing are magnetized to have the same polarity, there is little friction due to the magnetic repulsive force between the mover and the bearing, and it is possible to provide an actuator with a long life, which is suitable for hitting a pachinko machine. Has the benefit of.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a reciprocating linear motion actuator of the present invention.

FIG. 2 is an explanatory view of a bearing portion of the reciprocating linear motion actuator of the present invention.

FIG. 3 is an explanatory diagram showing a relationship between a time t and a drive current supplied to a stator winding in the reciprocating linear motion actuator of the present invention.

FIG. 4 is an explanatory diagram of a positional relationship between a stator and a mover and a moving force in the reciprocating linear motion actuator of the present invention.

FIG. 5 is a diagram for explaining the relationship between the positional relationship between the stator and the mover and the moving force in the reciprocating linear motion actuator of the present invention.

FIG. 6 is an explanatory diagram of a positional relationship between a stator and a mover and a moving force in the reciprocating linear motion actuator of the present invention.

FIG. 7 is a diagram for explaining the relationship between the set positions of the mover and the stopper with respect to the stator and the hold-move of the mover.

FIG. 8 is a diagram for explaining the relationship between the set positions of the mover and the stopper with respect to the stator and the hold-move of the mover.

FIG. 9 is a diagram for explaining the relationship between the set positions of the mover and the stopper with respect to the stator and the hold-movement of the mover.

FIG. 10 is a diagram for explaining the relationship between the set positions of the mover and the stopper with respect to the stator and the hold-move of the mover.

FIG. 11 is a diagram for explaining the relationship between the set positions of the mover and the stopper with respect to the stator and the hold-move of the mover.

FIG. 12 is a diagram for explaining the relationship between the set positions of the mover and the stopper with respect to the stator and the hold-move of the mover.

FIG. 13 is a diagram for explaining the relationship between the set positions of the mover and the stopper with respect to the stator and the hold-move of the mover.

FIG. 14 is a vertical sectional front view of a conventional reciprocating linear motion actuator.

[Explanation of symbols]

 1 Outer peripheral side stator 2 Inner peripheral side stator 3 Stator winding 4 Moving element shaft 5 Plunger 6 Bearing 7 Stopper 8 Return spring 9 Moving element

Claims (5)

[Claims] 1. A stator of n (n is 2 or an integer of 2 or more) poles excited by alternating positive and negative currents, a mover magnetized to n + 1 different poles, and a reciprocating movement of the mover. It consists of a stopper for the mover placed at the dead point position of
The distance between adjacent poles of the stator is equal to the distance between adjacent different poles of the mover, and the center of each magnetic pole of the mover at the dead center position of the mover corresponds to each of the stators. A reciprocating linear motion actuator characterized by being axially displaced from the center of the pole. 2. The moving element is movably supported by a bearing of a permanent magnet, and the inner surface of the permanent magnet is magnetized to have the same polarity as that of the corresponding portion of the moving element. A reciprocating linear motion actuator according to Item 1. 3. The reciprocating linear motion actuator according to claim 1, wherein the bearing of the permanent magnet supports either the lower surface or the upper and lower surfaces of the moving element. 4. The reciprocating linear motion actuator according to claim 3, wherein a supporting surface of the moving element supported by the bearing of the permanent magnet is either a flat surface or a curved surface. 5. The reciprocating linear motion according to claim 1, wherein the bearing of the permanent magnet is an annular body surrounding the moving body, and its cross section is any one of a circular shape, an oval shape and a prism shape. Activator.