JPH0534900B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application This invention relates to a method for driving a linear motor.

b. Prior Art A linear motor, for example a linear pulse motor, is conventionally driven by a control circuit as shown in FIG. That is, the control device 1 outputs a pulse signal (distance and direction) to the drive circuit 3, and the drive circuit 3 uses this pulse signal to control the movable element (primary A predetermined excitation current is supplied to each phase on the side) to drive it.

Linear motors, especially linear pulse motors, have the following characteristics: oven loop control is possible, errors in positioning do not accumulate, displacement proportional to the frequency of input pulses can be obtained, and speed can be controlled over a wide range. In addition, linear motors provide direct linear motion and do not require a motion conversion mechanism.
In recent years, it has come to be used in the fields of information equipment and industrial machinery because it has superior advantages such as a significant reduction in the number of parts, a corresponding reduction in the space it occupies, and ease of maintenance.

In particular, there is a demand for miniaturization in the field of information equipment, and linear motors are designed to meet this demand.However, the drive circuit and the movable element of the motor are generally connected by a flat cable, Sufficient space for movement was required.

C. Problems to be solved by the invention As mentioned above, the linear motor drive circuit and the motor mover (primary side) are generally connected by a flat cable with core wires corresponding to the number of phases of the motor. The cable is required to be sufficiently flexible so as not to hinder the movement of the movable element of the motor. Therefore, the flat cable requires sufficient space to move with the movable element, which conflicts with the demand for miniaturization of the device, and also because the cable repeatedly bends and stretches. There was a problem of rapid damage and deterioration.

This invention has been made by focusing on the above-mentioned problems. In other words, the motor drive circuit is
The object of the present invention is to provide a method for driving a linear motor that meets the demand for miniaturization by attaching the cable to the movable element of the motor and eliminating the need for a conventional multicore flat cable.

d. Means for Solving the Problems In order to achieve the above object, the present invention provides a method in which a motor drive circuit is attached to a movable element of a linear motor, and the electric power supplied to the drive circuit and the drive circuit are controlled. The signals are supplied by the same feed path along the stator of the linear motor.

e Effect With this configuration, the electric power supplied to the linear motor is directly supplied from the drive circuit attached to the movable element. Therefore, there is no need for long multi-core flat cables as in the past.
The space required for this is significantly reduced. The drive circuit attached to the mover can be easily miniaturized by using an IC for the distribution circuit and cooling the power transistor in the excitation circuit by running ventilation.

The power necessary for the drive circuit is collected from a power supply path provided along the stator, for example by a brush provided on the movable element, and is supplied to the drive circuit.
Furthermore, signals for controlling the drive circuit are transmitted by commonly using the power supply line as a carrier wave transmission line. Therefore, there is no need to provide a separate signal line.

f Example Next, an example of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the invention. That is, the DC power supply 1 supplies the necessary DC to the control device 3, and also supplies the current necessary for driving the motor to the drive circuit 9 attached to the movable element 7 of the linear pulse motor via the power supply path 5. Control device 3
outputs the direction and amount of movement of the motor as a pulse signal.

This pulse signal is transmitted to the FM modulation circuit 11, for example.
It is FM modulated at , passes through the capacitor C, passes through the feed line 5, and is transmitted to the FM demodulation circuit 13 mounted on the movable element 7, where it becomes the original pulse signal.
Input to drive circuit 9. The drive circuit 9 uses input pulses to generate signals via the built-in distribution circuit and excitation circuit.
Excitation current is supplied to each phase winding 15 of the movable element in a predetermined order, and the movable element 7 is moved to the commanded position. The modulation of the signal may be AM or PCM modulation.

Two power supply methods are illustrated in FIGS. 2 and 3. That is, in the one shown in FIG. 2, a power supply path 5 is provided along the stator 17 of the linear pulse motor, and the roller 1
Brush 2 provided on mover 7 supported by 9
1 to collect current. In the one shown in FIG.
The left and right portions of the movable roller 19 that are in contact with the rollers 19 that support the rollers 19 are electrically separated, and this is used as a power supply path, and current is collected from the left and right rollers 19 that are insulated from each other by an insulator 25 on the movable element. be.

In addition to the above methods, there are also methods for using a combination of a guide rail and rollers or brushes, or a combination of an overhead wire and a pantograph. Furthermore, this method can be applied not only to linear pulse motors but also to linear DC motors.

g. Effects of the invention As understood from the above explanation, this invention has the configuration described in the claims.
According to this method, the movable element and the drive circuit are integrated, and the conventional multi-core flat cable is not used, so the device can be made smaller and maintenance is also easier.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of this invention;
3 and 3 are explanatory diagrams of two embodiments of the power feeding method of the present invention, and FIG. 4 is an explanatory diagram of a conventional method for driving a linear pulse motor. The same reference numerals in the figures indicate the same or equivalent items. (Explanation of symbols representing main parts of drawings) 1
...DC power supply, 3...Control device, 5...Power supply path, 7...Mover of linear pulse motor, 9...Drive circuit, 11
...FM modulation circuit, 13...FM demodulation circuit, 15...mover winding, 17...stator of linear pulse motor,
19... Support roller of mover, 21... Current collection brush, 23, 25... Insulator.

Claims (1)

[Claims] 1. A motor drive circuit is attached to the movable element of the linear motor, and power to be supplied to the drive circuit and signals for controlling the drive circuit are supplied through the same power supply path along the stator of the linear motor. A method of driving a linear motor characterized by: