JPH0965635A - Linear driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of large impact sounds so that a large driving force can be obtained in an initial stage by providing first and second magnetic pole which are held at a prescribed wheel base from an actuator, made of annular magnetic materials, and have the same width which is equal to the wheel base and six exciting coils which excite the first and second magnetic poles. SOLUTION: Side plates 3a and 3b are respectively fixed to the left and right sides of a cylindrical enclosure 2 and an actuator 1 is linearly driven leftward and rightward. Loads are successively connected to the end section of the actuator 1. The cylinder 2 which is made of a soft magnetic material as the enclosure becomes a magnetic path. Annular magnetic poles 4a and 4b are provided on the inner peripheral surface of the cylinder 2 in projecting states. The magnetic poles 4a and 4b have the same width and the separating distance between the poles 4a and 4b is set as a pole width, and then, an annular coil 5a is mounted between the poles 4a and 4b. A prescribed load 5 can be driven by repeatedly conducting six exciting coils by successively inputting input pulses to the coils one set by one set, with one set being composed of six input pulses.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for automatically reciprocating a required member by a set stroke during an assembly operation automatically by a member of a mechanical device.

[0002]

2. Description of the Prior Art There are electromagnetic plungers to achieve the same purpose. There is also an apparatus for moving members by rotating rollers arranged side by side.

[0003]

The known electromagnetic plunger has the following problems to be solved. First problem Generates a loud impetus when activated. Second problem The stroke of the actuator cannot be selected to have an arbitrary size and cannot reciprocate. Third Problem The moving stroke of the actuator cannot be increased. Fourth Problem There is a disadvantage that the driving force is small at the beginning when the driving force is most required, and the driving force at the end of the operation becomes the maximum driving force when it is not required so much. Fifth Problem A means for linearly increasing in response to a current flowing without saturating the driving force is required.

[0004]

[Means for Solving the Problems] An actuator, which is supported so as to be able to move left and right in the direction of the central axis of an outer casing, and an annular soft magnetic body held at a predetermined distance between the axes, The first and second magnetic poles having the same width as the distance between the first and second magnetic poles are provided.
The above-mentioned outer casing in which six sets of magnetic poles each having a soft magnetic material serving as the magnetic path of the second magnetic pole are fixed to the inner peripheral surface along the axial direction at a predetermined distance, and the first and second magnetic poles. 6 exciting coils that excite the coil and a plurality of soft coils that are fixed coaxially with the above-mentioned actuator at the same pitch and have a width substantially equal to the distance between the outer sides of the first and second magnetic poles. A magnetic cylinder,
A means for holding the outer circumference of the soft magnetic material cylinder and the inner circumferences of the first and second magnetic poles facing each other with a slight gap therebetween, and detecting the relative position of the magnetic pole and the soft magnetic material cylinder in the axial direction. By energizing the corresponding exciting coil by the position detection signal obtained by or the set electric signal obtained in order, the soft magnetic cylinder and the first magnetic pole are completely opposed to each other and the magnetic path is closed, A magnetic attraction force is generated between the second magnetic pole and the soft magnetic cylinder by the magnetic flux to generate a relative driving force by 2/3 of the magnetic pole width, and a corresponding magnetic pole is generated by an exciting coil that is sequentially energized. The energization control circuit generates a relative driving force in one direction by a magnetic attraction force with the soft magnetic material column.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to FIG. Since the same symbols in the drawings are the same members or members that have the same function, duplicate description will be omitted. FIG. 1 is a diagram showing the appearance. Side plates 3a and 3b are fixed to the left and right of the cylindrical outer casing 2, and the actuator 1 (cylindrical) is linearly driven left and right. A load (not shown) is connected to the end of the operator 1. FIG. 2 is a cross-sectional view of FIG. In FIG. 2, the soft magnetic cylinder 2 serves as a magnetic path that also serves as an outer casing. An annular magnetic pole 4 is provided on the inner peripheral surface of the cylinder 2.
a, 4b are provided to protrude. The magnetic poles 4a and 4b have the same width, and the distance between them is the magnetic pole width.
An annular exciting coil 5a is mounted between 4b.

Although not shown, the side plates 3a and 3b described above are fastened to both sides of the cylinder 2. The hole in the center of each of the side plates 3a and 3b serves as a bearing, and supports the cylinder 1 which is an actuator made of a soft magnetic material so as to slide left and right. Actuator 1
, Soft magnetic material cylinders 1a, 1b, 1c, ... Having a large diameter are made by cutting, and the width of the cylinder is made equal to the distance between the outer sides of the magnetic poles 4a, 4b. This equal meaning is at least equalized, and it does not matter if it is increased by some length. The outer circumference of the cylinders 1a, 1b, 1c, ... And the magnetic poles 4a,
A load 5 is continuously provided at the right end of the cylinder 1 so as to face the inner circumference of 4b with a gap of 0.1 to 0.2 mm.

Magnetic poles 4c and 4 having the same structure as the magnetic poles 4a and 4b.
d, magnetic poles 4e and 4f, magnetic poles 4g and 4h, magnetic poles 4i and 4
j and magnetic poles 4k and 4l are fixed inside the outer casing 2 as shown in the figure. The relative position of each magnetic pole and each cylinder is as shown in the figure. The distance between the outer sides of each pair of magnetic poles (for example, the one indicated by the arrow a) is the magnetic pole width. As shown, the cylinders 1a have their right ends facing the left ends of the magnetic poles 4c. The outer surface of the cylinder 1a faces the magnetic pole 4d via a gap. The means for achieving the above configuration will be described below. The soft magnetic material ring 4a is formed, and is inserted and fixed inside the outer casing 2. Next, the exciting coil 5a, which is wound in an annular shape and solidified with plastic, is inserted into the outer casing 2, and then the soft magnetic material circular ring 4b is formed, which is inserted and fixed inside the outer casing 2.
The other magnetic poles 4c and 4d, their exciting coil 5b, and the like can also be configured as shown by the means described above.

The terminals of the exciting coils 5a, 5b, ...
It is led out from the pores provided in the. When the exciting coil 5b is energized, the magnetic flux passes through the magnetic pole 4c → the cylinder 1a → the magnetic pole 4d → the outer casing 2 → to form a closed circuit, so that the amount of the magnetic flux is large. Therefore, the driving force of the cylinder 1 acting as the actuator in the direction of the arrow b is It becomes large and drives the load 5 in the same direction. In the above-described operation, the lines of magnetic force between the cylinder 1a and the magnetic poles 4d are perpendicular to the facing surface and there is no attraction force in the direction of the arrow b, but since the facing area of the void is large, the magnetic resistance is remarkably small and the amount of lines of magnetic force is large. These lines of magnetic force become large leakage magnetic flux in the opposing portions of the ends of the cylinder 1a and the magnetic pole 4c, and contribute greatly to the driving force in the direction of arrow b. Therefore, there is a feature that it is possible to obtain a driving force which is about six times that of a conventional linear drive device of this type.

The graph of FIG. 3 is a graph of the load driving force, where the horizontal axis is the movement distance of the actuator 1 and the vertical axis is the suction force. In a known electromagnetic plunger, the initial attractive force is small as shown by the curve 7, and the final attractive force is maximum. In the device of the present invention, as shown by the curve 8, the initial suction force is large and then gradually decreases. Therefore, there is a feature that a large load can be driven. The above operation will be described with reference to FIG. In FIG. 4, the magnetic pole 4c and the cylinder 1a show a cross section,
Magnetic force lines 9a, 9b, 9c indicated by arrows are generated at the facing portions of the ends. At this time, the magnetic pole 4c is excited to the N pole, and the cylinder 1a is excited to the S pole by magnetic induction. Line of magnetic force 9a at the facing portion
Has little effect on the suction force in the direction of arrow b,
The attraction force in the direction of arrow b is obtained by the magnetic force line 9c. The attraction force by the magnetic force line of the arrow 9a is proportional to the square of the current of the exciting coil, and the attraction force by the magnetic force line of the arrows 9b and 9c is proportional to the first power of the current. When the gap length becomes 0.1 mm or less, the magnetic force line of the arrow 9a becomes perpendicular to the facing surface and the suction force disappears. Therefore, as shown by the curve 8 in the graph of FIG. 3, the initial suction force is large and the suction force is flat. There is a characteristic that becomes.
As can be understood from the above description, by controlling the energization,
There is a feature that the load can be linearly driven in a silent mode with a large initial driving force.

In FIG. 2, when the exciting coil 5b is energized, the actuator 1 is driven by ⅔ of the magnetic pole width in the direction of the arrow b, and when the exciting coil 5c is energized next, the magnetic pole width of 2 is further increased.
It is driven by / 3. As described above, by energizing the exciting coil in the order of symbols 5b → 5c → 5d → ...
The actuator 1 is driven in the direction of arrow b by 2/3 of the magnetic pole width. Therefore, a linear stepping motor can be constructed by utilizing an electric circuit for energizing a well-known stepping motor. The order of energization in this case is as described above, but if the order of energization is reversed, it is driven in the opposite direction. It is also possible to fix the actuator 1 to the main body and drive the outer casing 2 left and right. In this case, the load is mounted on the outer casing 2.

The exciting coil is represented by the symbols 5b → 5c → 5d → 5a.
When the actuator 1 is energized, the actuator 1 is step-driven in the direction of the arrow b, but the energization of the exciting coil 5a causes the actuator 1 and the magnetic pole to return to the relative positions in FIG. Therefore, the step operation can be continuously performed by energizing the excitation coil in the order of symbols 5b → 5c → 5d →. The actuator 1 can be reciprocated, but a spring can be provided on the actuator 1 to spring back.

As shown by the dots between the cylinders 1a, 1b, ..., By filling and solidifying with a plastic material, the actuator 1 becomes a single cylinder. In this case, by coating a slidable plastic material on the outer circumference, the bearing of the cylindrical actuator becomes each magnetic pole, and there is an advantage that the bearing of the actuator 1 is not particularly required. In FIG. 2, the case where the cylinder 1a starts from the position shown in the direction of the arrow b has been described, but when the cylinder 1a starts from the position of the dotted line C, the order of energizing the exciting coil is 5a → 5b.
→ 5c → ... 5a → 5b → ... The above-mentioned energization can be performed by the pulse output of a well-known pulse oscillator.

As can be understood from the above description, the required load 5 is driven by forming a set of six input pulses and repeatedly energizing each of the six exciting coils with the input pulses sequentially input. You can By reversing the order of the exciting coils by the input pulse, the exciting coils 5f → 5e →
Actuator 1 by energizing 5d → 5c → 5b → 5a
Is driven to the left. It is also possible to provide a spring in the operator 1 and to spring back to the original position by cutting off the energization of the exciting coil after the operation of the operator 1 is completed.

The above-mentioned operation fixes the actuator 1 to the main body,
It can also be carried out by supporting the cylinder 2 so as to be movable left and right and mounting a load on the cylinder 2. Next, a case where the device of FIG. 2 is operated as a linear motor will be described. Circular pores are provided in the cylinder 2 serving as the outer casing, and coils (10 to 20 turns) 10a, 10b, ...
10f are arranged at a pitch of 2/3 of the magnetic pole width. Column 1
The outside of a faces the coils 10a, 10b, ... Through a slight gap. A high-frequency current of about 1 to 5 megacycles is applied to each coil, and when the coil surface faces the outside of the cylinder 1a, copper loss increases and impedance changes. A position detection signal of the cylinder 1a, that is, the actuator 1 can be obtained by this change.

Next, the description will be made with reference to FIG. In FIG. 5, symbol 10 is an oscillation circuit of 1 megacycle, the output of which is applied to a bridge circuit composed of a coil 10a and resistors 15a, 15b, 15c, and diodes 11a, 11
b, the operational amplifier 13 through the capacitors 12a and 12b
Inputs are equal and their outputs are held low. Block circuits indicated by symbols 14a, 14b, 14c, 14d, and 14e have exactly the same configuration as the circuit including the coil 10a described above.
0b, 10c, 10d, 10e and 10f.
When the coil 10a of FIG. 2 faces the end of the cylindrical surface by moving the cylinder 1a to the right, the impedance decreases due to the eddy current loss of the cylindrical surface, and the energizing current increases. Therefore, since the input of the + terminal of the operational amplifier 13 in FIG. 5 increases and its output is converted to a high level, the output terminal 18a of the flip-flop circuit (hereinafter abbreviated as F circuit) 16a is also converted to a high level.

When the cylinder 1a in FIG. 2 further moves by ⅔ of the magnetic pole width, the outside surface of the cylinder 1a faces the coil 10b, and the lower input of the F circuit 16a becomes high level. Although not shown in the figure, the inputs of the F circuits 16a, 16b, ... Are converted into a short pulse input by a known means. Therefore, the output of the block circuit 14a causes the output of the terminal 18a to disappear and the output of the terminal 18b. Convert. For the same reason, the outputs of the block circuits 14b, 14c, 14d, 14e by the coils 10c, 10d, 10e, 10f sequentially obtain the outputs of the terminals 18c, 18d, 18e, 18f. 18f are energized to excite the exciting coils 5a, 5b, ..., 5f of FIG. 2 so that the cylinders 1a, 1b, 1c, 1d, 1e are attracted and driven by the magnetic poles in the direction of arrow b. Can form a linear motor. As described above with reference to FIG. 4, the driving force has the effect of being significantly increased. As in the case of the stepping motor, the operator 1 can be driven leftward by reversing the order of energizing the exciting coil.

[0017]

EXAMPLE With the construction shown in FIG. 1, when the outer casing 2 has a diameter of 60 mm and a length of 250 mm, the maximum driving force of the actuator 1 is 20 kg and the energization of the exciting coil is 200 ampere-turn.

[0018]

A cylindrical stepping motor or a linear motor can be constructed by linearly driving a forward drive of a load silently. It is possible to obtain a linear drive device having a large initial drive force and a small decrease in the drive force thereafter. The driving force has the effect of being about six times that of the conventional means.

[Brief description of drawings]

FIG. 1 is an external view of the apparatus of the present invention.

FIG. 2 is a sectional view of the apparatus of the present invention.

FIG. 3 is a graph of a moving distance of an actuator and a driving force.

FIG. 4 is an explanatory diagram of a magnetic flux generated by a magnetic pole.

FIG. 5: Energization control circuit diagram for excitation coil

[Explanation of symbols]

 1 Cylindrical actuator 1a, 1b, ... Soft magnetic cylinder 2 Soft magnetic cylinder outer casing 4a, 4b, 4c, 4d, ... Magnetic poles 3a, 3b Side plate 5 Loads 5a, 5b, 5c, ... Exciting coils 7, 8 Curve of attraction force 9a, 9b, 9c Curve of attraction force 10a, 10b, 10c, ... Position detection coil 10 Oscillator 13 Operational amplifier 16a, 16b, 16c, ... Flip-flop circuit

Claims (1)

[Claims] 1. An actuator, which is supported so as to be able to move to the left and right in the direction of the central axis of the outer casing, and an annular soft magnetic material held at a predetermined axial distance, and is the same as the axial distance. First width
The six magnetic poles having the second magnetic pole and the soft magnetic material serving as the magnetic paths of the first and second magnetic poles are fixed to the inner peripheral surface along the axial direction at a predetermined distance. The outer casing, the six exciting coils that excite the first and second magnetic poles, are fixed coaxially with the above-described actuator at the same pitch, and
A plurality of soft magnetic material cylinders having a width substantially equal to the distance between the outer sides of the first and second magnetic poles, and inner circumferences of the first and second magnetic poles facing the outer circumferences of the soft magnetic material cylinders. Corresponding to the means for holding and to face each other with a slight gap, and the position detection signal obtained by detecting the relative position of the magnetic pole and the soft magnetic cylinder in the axial direction, or the electric signal obtained in the set order. By energizing the exciting coil, the soft magnetic cylinder and the first magnetic pole are completely opposed to each other to close the magnetic path, and the magnetic flux causes a magnetic attraction force between the second magnetic pole and the soft magnetic cylinder. Is generated and a relative driving force is generated by 2/3 of the magnetic pole width, and a relative driving force is generated in one direction by the magnetic attraction force between the corresponding magnetic poles and the soft magnetic material column by the exciting coil that is sequentially energized. And a power generation control circuit for generating the generated current. Drive.