JPH0619668B2 - Movable iron core type electromagnet actuator - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a movable iron core type electromagnet actuator, and more particularly to a movable iron core type electromagnet actuator having a large acting force, stability and excellent controllability. is there.

(Prior Art) In recent years, along with the progress of control technology, progress has been made in automation in the industrial world, and various automatic control devices that support it have been developed. In particular, industrial robots have been steadily achieving results, as can be seen in, for example, the transfer and weighting of workpieces in an assembly plant and the welding work in automobile manufacturing lines. Motors having rotors such as DC servo motors and AC servo motors are widely used as actuators for such industrial robots.

(Problems to be Solved by the Invention) However, not only the DC servo motor but also a motor having a general rotor has a direction of magnetic flux orthogonal to a direction of acting force, as is clear from Fleming's left-hand rule. It has a drawback that its own weight ratio, that is, the acting force per unit weight is small. In this respect, by using the electromagnet actuator in which the direction of the magnet and the direction of the acting force are parallel, the self-weight ratio can be improved to 100 to 200 times that of the DC servo motor.

However, the attractive force of the electromagnet in this type of conventional electromagnet actuator is proportional to the square of the current flowing in the coil,
Since it is inversely proportional to the square of the gap length, it is non-linear and unstable, and there is a problem in controllability, and it is merely used for simple control modes such as solenoid valves and solenoid relays.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned problems and to provide a movable iron core type electromagnetic actuator which is stable and has a good controllability while generating a large acting force per unit weight.

(Means for Solving Problems) In order to solve the above problems, the present invention provides a drive source,
A pair of magnetic plates connected to the drive source and driven in synchronization, and an actuating member located between the magnetic plates and provided with a pair of electromagnets back to back and movable in a linear direction,
A detector for detecting the state displacement amount of the actuating member, and reading the detected state displacement amount to obtain a deviation between the target position of the actuating member and the actual position of the actuating member, and a voltage based on the deviation. An electronic control device that outputs a command and a current control device that adjusts the exciting current of each electromagnet based on the voltage command are provided, and the operating member is directly driven by the electromagnetic force generated between the magnetic plate and the electromagnet. It is something that is done.

(Operation) FIG. 1 is an overall configuration diagram of the movable iron core type electromagnet actuator of the present invention.

As shown in this figure, a pair of electromagnets 1a, 1b is provided with an operating member 1 attached back to back, and this operating member 1 is arranged so as to be movable in a linear direction. Further, the magnetic plates 2a and 2b are movably arranged so as to face the electromagnets 1a and 1b. The power from the drive source 7 is transmitted to the magnetic plates 2a and 2b through the synchronizer 8 and drives them in synchronization.

First, when a movement command to the target position is given to the actuating member 1, a voltage command Cs is given from the electronic control unit 5 to the drive source 7, and the power of the drive source 7 passes through the synchronizer 8 to the magnetic plates 2 a ,.
2b, the magnetic plates 2a and 2b move in a linear direction in synchronization. In response to this, the operating member 1 moves. Then, the displacement amount of the operating member 1 is detected by the position detector 3 and read by the electronic control unit 5. On the other hand, the exciting currents of the electromagnets 1a and 1b are detected by the current detectors 4a and 4b and read into the electronic control unit 5. The electronic control unit 5 obtains the deviation between the target position and the actual position of the operating member 1 and outputs the voltage commands C _A and C _B to the current control units 6a and 6b based on this deviation. In the current control devices 6a and 6b, the electromagnets 1a and 1b are based on the voltage commands C _A and C _B.
The exciting current is adjusted to control the movable member 1 to the target position.

This operation is repeated between the pair of electromagnets 1a and 1b.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings. The "movable iron piece type electromagnet actuator", which is the basic type of the present invention, has already been proposed and previously filed by the same inventor / applicant as the present application.

FIG. 2 is a configuration diagram of an embodiment of the movable iron core type electromagnet actuator of the present invention.

First, the configuration of the movable iron core type electromagnet actuator will be described. In the figure, 11 is an actuating member, which is installed so as to be movable in a linear direction. Although not shown, the actuating member is provided with an actuator that is integrally driven with the actuating member. Reference numerals 11a and 11b are a pair of electromagnets provided back to back on the operating member 11. Reference numerals 12a and 12b denote magnetic plates movably provided at positions facing the electromagnets 11a and 11b, respectively. Reference numeral 13 denotes a position detector that detects the amount of displacement of the operating member 11, for example, a potentiometer,
14a and 14b are current detectors composed of Hall elements that detect the exciting current of the electromagnets, and 15 is an electronic control unit, such as a central processing unit (CPU) 15-1 and an I / O port 15-.
2, memory (MEM) 15-3, comparator 15-4, observer 15-5, manual data input device (M
DI) 15-6, display 15-7, etc.,
The displacement amount of the operating member 11 and the exciting currents of the electromagnets 11a and 11b are read, and the voltage commands C _A , C _B , and C _S are output. The comparator 15-4 and the observer 15-5 do not necessarily have to have a hardware configuration. 16a, 16
b receives the voltage commands C _A and C _B and receives electromagnets 11a and 11b.
2 is a pair of DC choppers that adjust the exciting current of the. Although not shown, the DC chopper is, for example, a transistor chopper, that is, a DC chopper that applies a PWM signal adjusted by the voltage commands C _A and C _B to the base of a transistor incorporated in a bridge to drive the base is used. it can. On the other hand, 17 is a servo motor, and 18 is a synchronizing device for receiving energy from the servo motor and transmitting this energy to the magnetic plates 12a and 12b and synchronizing them, for example, both are driven simultaneously. Rack gears are used. The exciting current of the electromagnets is made to flow in advance so that the gaps between the electromagnets and the magnetic plate are almost equal.

Next, the operation of the movable iron core type electromagnet actuator will be described.

As described above, the actuating member 11 provided with the electromagnets 11a and 11b is movable in the linear direction. Therefore, when a command to drive the operating member 11 to the target position is given, for example, the command is a voltage command C _S from the electronic control unit 15 to the servo motor 17 via the I / O port 15-2.
Given as. Then, the servo motor 17 is driven, and the power from the servo motor 17 is transmitted to the magnetic plates 12a and 12b via the synchronizer 18, and both are driven in synchronization. Then, these magnetic plates 12a, 12b
The actuating member 11 also starts moving toward the target position in response to the movement. The torque in this case is the electromagnet 11a.
And the magnetic plate 12a and the attraction force between the electromagnet 11b and the magnetic plate 12b. The displacement amount of the operating member 11 is detected by the position detector 13 and read into the electronic control unit 15.
In the electronic control unit 15, the target position of the operating member 11 is set in advance in the COM 15-4 as a reference value by the MDI 15-6.
The deviation from 1 is obtained, and based on this deviation, the voltage command C _A ,
Output C _B. The DC choppers 16a and 16b receive the voltage commands C _A and C _B and adjust the exciting current of each electromagnet to control the operating member 11 to the target position.

This operation is repeated between the pair of magnetic plates 12a and 12b.

Here, the relationship between the electromagnetic action force and the gap length in the electromagnetic operating unit will be described. FIG. 3 shows an electromagnet device, that is,
The dimensions of the electromagnet and the magnetic plate are shown in units of mm.
The iron core is 60 in the Z direction and the magnetic body is 140 in the Z direction. The number of turns of the coil is 1840 on one side. The exciting current is the rated current 4A. The gap length of the magnetic body is equivalently reduced and the attractive force is increased. The central part is thickened to make it larger. The magnetic plates 12a, 12b and the electromagnets 11a, 11
By adjusting the air gap with b, it is possible to improve the magnetic balance and prevent step-out of the actuator due to too large air gap when either one of the electromagnetic actuating parts is fixed. can do. In addition, the gap between the electromagnet and the magnetic plate is the operating member 11
It is obvious that it has a buffer function when it is over-shorted.

FIG. 5 is a configuration diagram of an embodiment of an electromagnetic actuating portion of this actuator. FIG. 5 (a) is a diagram showing a state in which the actuating member 21 is located on the most B side, and FIG. 5 (b) is actuating. Member 21
It is a figure which shows the state located in the most A side. In this figure, 21 is an actuating member, 21a and 21b are a pair of electromagnets provided back to back on the actuating member 21, and 22 is a bearing, which movably supports the actuating member 21 in a linear direction with respect to a fixed portion. Reference numerals 23a and 23b are rotary shafts, and 24a and 24b are magnetic plates composed of eccentric members whose radii continuously change around the rotary shafts 23a and 23b. It should be noted that an exciting current is made to flow in the electromagnets in advance so that the gaps between the magnetic plates and the electromagnets become substantially equal.

Next, the operation of this electromagnetic operating unit will be described. As shown in FIG. 5 (a), the magnetic plate 24b is located at the starting point. On the other hand, the magnetic plate 24a is arranged at a position where the rotation angle of the rotating shaft is delayed by about 90 degrees from the magnetic plate 24b. Therefore, the rotating shafts 23a and 23b synchronously rotate in the direction of the arrow, and the operating member 21 also moves correspondingly. That is, the attraction force acts between each electromagnet and the magnetic plate, and the operating member can be controlled to a desired position.

FIG. 6 is a configuration diagram of another embodiment of the electromagnetic actuating portion of this actuator. FIG. 6 (a) is a diagram showing a state in which the actuating member 31 is located on the leftmost side, and FIG. 6 (b) is an actuating operation. Member 3
It is a figure showing the state where 1 is located in the rightmost side. In this figure, 31 is an operating member, 31a and 31b are operating members 3
1 is a pair of electromagnets provided back to back, and 32 is a bearing, which supports the actuating member 31 movably in a linear direction with respect to the fixed portion. 33a and 33b are electromagnets 31
a and 31b, which are magnetic plates disposed to face each other, 34
a and 34b are drive members in which rack gears are formed,
Magnetic plates 33a and 33b are provided at the tip portions. 35a,
Reference numeral 35b denotes a drive gear, for example, a pinion gear, which is configured to rotate in the same direction and at the same speed in synchronization with the power from the servomotor.

Next, the operation of the actuating portion of the actuator will be described.
a, 35b are driven, and by this drive, the magnetic plates 33a, 3b
3b also moves, and the actuating member 31 also moves accordingly.
This actuating member 31 is feedback-controlled and moved to the target position, but this control method is the same as that of the above-mentioned embodiment, and therefore its explanation is omitted.

In addition, in the present invention, since the gap between the electromagnet and the magnetic plate can be used so as to be as small as possible, a strong acting force can be obtained as apparent from FIG. Therefore, it is possible to obtain an actuator as a power source that requires strong power. When the moving distance of the operating member is short, the magnetic plate does not drive,
It is also possible that only the actuating member is actuated by the exciting coil of the electromagnet. Needless to say, the program of the operating member can be controlled by preliminarily storing a program in the memory of the electronic control unit.

Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made, which are not excluded from the scope of the present invention.

(Effects of the Invention) As described in detail above, according to the present invention, the actuating member is driven by utilizing the large attractive force between the electromagnet and the magnetic plate that face each other, and the stable and good controllability is achieved. A movable iron core type electromagnetic actuator can be provided.

In particular, in the present invention, since the gaps between the electromagnets and the magnetic plate can be moved in a state where the gaps between the electromagnets and the magnetic plates are substantially equal, it is easy to keep the magnetic balance and the gap between the one electromagnet and the magnetic plate is too wide. It is possible to avoid an uncontrollable state of the operating member and a delay in control response, and it is not necessary to provide auxiliary means such as a spring. In addition, since a balanced suction force is working, it is also strong against external disturbances.

As described above, according to the present invention, the actuator of the robot can be utilized by taking advantage of the fact that the acting force is large, stable, and excellent in controllability.
It is suitable for use in vibration exciters and vibration isolator.

As described above, the present invention has various advantages, and the effects brought by the present invention are remarkable.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a movable iron core type electromagnet actuator of the present invention, FIG. 2 is a configuration diagram of an embodiment of the actuator, FIG. 3 is a dimensional diagram of an electromagnetic device, and FIG. 4 is an attraction force and a gap length. 5 is a configuration diagram of an embodiment of an electromagnetic actuating portion of the actuator, and FIG. 6 is a configuration diagram of another embodiment of an electromagnetic actuating portion of the actuator. 1, 11 ... Actuating member, 1a, 1b, 11a, 11b ...
... electromagnets, 2a, 2b, 12a, 12b ... magnetic plates,
3, 13 ... Position detectors, 4a, 4b, 14a, 14b
...... Current detectors, 5, 15 ...... Electronic control devices, 6a, 6
b, 16a, 16b ... current control device, 7 ... drive source,
8, 18 ... Synchronizer, 17 ... Servo motor.

Claims (3)

[Claims] 1. A drive source; (b) a pair of magnetic plates connected to the drive source and driven in synchronization; (c) a pair of electromagnets located between the magnetic plates and back to back. And an actuating member that is movable in a linear direction and is provided in (d) a detector that detects the amount of state displacement of the actuating member, and (e) reads the detected amount of state displacement, and a target position of the actuating member. Obtaining the deviation between the actual positions of the actuating members,
An electronic control device that outputs a voltage command based on the deviation and (f) a current control device that adjusts the excitation current of each electromagnet based on the voltage command are provided, and (g) occurs between the magnetic plate and each electromagnet. A movable iron core type electromagnetic actuator characterized in that the actuating member is directly driven by an electromagnetic force. 2. The pair of magnetic plates have shafts pivotally supported,
The movable iron core type electromagnet actuator according to claim 1, characterized in that it is an eccentric member whose radius from the axis changes continuously. 3. The movable iron core type electromagnet actuator according to claim 1, wherein the pair of magnetic plates are arranged so as to be movable in a linear direction.