JPS61132094A - Device of driving dc brushless motor for inspection - Google Patents

Abstract

PURPOSE:To inspect a motor with a simple structure by obtaining signals of rotating sped and direction from a rotating pulse output circuit having a drive device for inspecting a motor. CONSTITUTION:When connectors 3, 7, 8 are connected and a voltage is applied to a DC power source 1, a brushless motor 10 rotates. The rotating speed at that time can be measured by a digital tachometer 2. An output from a position sensor 12 provided in a brushless motor 10 is inputted to a transistor drive circuit 4, logically processed, output to a transistor switching circuit 6, and a voltage is sequentially applied to the field winding 11 of the motor 10. A rotating pulse output circuit 5 judges whether the outputs of the circuit 4 are produced in the prescribed sequence or not to detect the rotating malfunction.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an inspection drive device for inspecting the rotational speed and rotational direction of a DC brushless motor in the production process of the motor. It is something.

Conventional technology The conventional method for testing the rotation speed of a DC brushless motor is to fix a disk-shaped jig with reflective tape attached to the motor output shaft to reflect light, rotate it at the same time as the motor, and place it opposite the reflective disk. The rotational speed is measured by the pulse output of a photoelectric detector placed in the center.

Alternatively, a method has been used in which a rotation detector such as a rotary encoder is connected to the motor output shaft and the rotation speed and rotation direction are determined from the output signal of the detector.

Problems to be Solved by the Invention However, in the inspection process for mass-producing brushless motors, the conventional method involves individually connecting discs or rotary encoders to the output shaft of the motor, and removing them after inspection. The necessary inspection was time-consuming.

In addition, when installing a disc or detector on the motor output shaft, in order to minimize mechanical loss to the motor, it is necessary to install it in a way that does not disrupt the dynamic balance, so special measures must be taken to ensure positioning and balance. I had to think of a suitable device.

The present invention has been made to improve these points,
It is an object of the present invention to provide a drive device for testing a brushless motor that can determine the number of rotations and the direction of rotation without attaching any disk or detector to the output shaft of the motor.

Means for Solving the Problems In order to solve the above problems, the present invention focuses on the rotation principle of DC brushless motors, and instead of directly obtaining signals for measuring the rotation speed and direction of rotation from the output shaft of the motor. Signals regarding the number of rotations and the direction of rotation are obtained from a rotation pulse output circuit provided in a drive device for motor inspection.

Effect of the present invention The transistor drive circuit of a DC brushless motor inputs a position signal of the rotor of the motor, outputs a transistor output switching signal, and changes the field of the front distribution motor by the switching action of the transistor that receives the signal. Focusing on the fact that voltages are applied to the magnetic windings in a predetermined order, a rotating magnetic field is formed, and the rotor is driven to rotate. A signal synchronized with the switching of the transistor is output only when the signals are output in a predetermined order, and this signal is used as a rotation signal.

Embodiment FIG. 1 is a block diagram showing an embodiment of a DC brushless motor drive device equipped with a rotation synchronization pulse generation circuit according to the present invention.

In FIG. 1, 1 is a DC power supply for driving a motor, 2 is a digital tachometer, 9 is a drive device for testing a DC brushless motor, and 1o is a brushless motor to be inspected.

In the above configuration, when each device is connected with the connectors 3, 7.8 as shown in FIG. A DC pulse corresponding to the number of rotations is outputted, and the number of rotations can be easily measured using the digital tachometer 2.

The brushless motor 1o shown in Fig. 1 is a DC motor in which the brushes and commutator are replaced with a position sensor and a semiconductor electronic circuit, and the position sensor uses three Ho elements to detect the position of the rotor. And Ill. The output of the position sensor 12 is input to the transistor drive circuit 4, subjected to logic processing, and output to the transistor switching circuit 6. Voltage is applied to the field winding 11 of the brushless motor 10 in a predetermined order, causing rotation. This is an electric motor in which the rotor is rotationally driven by a layered magnetic field.

Therefore, in order to check the rotational state of the brushless motor 1o, it is sufficient to check whether the transistors are switched in a predetermined order. The rotational pulse output circuit 5 determines whether the output of the transistor drive circuit 4 is in a predetermined order at points a, b', and a, and if it is in the predetermined order, outputs two pulses every time the rotor rotates once. The logic circuit is configured such that the output signals are generated in a predetermined order, and the output signals are not generated except in a predetermined order.

FIG. 2 shows a of the transistor drive circuit 4 when the brushless motor 10 is rotating counterclockwise.

This shows the output status at each point b and c, and it is normal if there is a falling pulse at point b between the falling edge at point a and the falling edge at point 0.

Therefore, the pulse d is created using the falling edge of point a and the falling edge of point b, and the logical product of the pulse of d and the pulse of 5, which is an inversion of b, is output to e. It was designed to do so. This pulse e is generated twice per rotation of the rotor, and by outputting this signal to the digital tachometer 2, it is possible to measure the number of rotations i of the shiftless motor 1o.

FIG. 3 shows the output states of points a, b, and c when the brushless electric motor 4y1o rotates clockwise. In the case of clockwise rotation, when the d pulse and the b pulse are ANDed, the output θ is not generated, and it can be determined that the rotation is abnormal.

Effects of the Invention As is clear from the above explanation, according to the present invention, when inspecting the number of rotations and the direction of rotation of a brushless motor, it is possible to detect things that conventionally could not be done without attaching a detector such as Ioj et al. to the motor shaft. The present invention is extremely useful in practical terms because it allows for easy inspection by simply connecting a tachometer to the output terminal of the drive device for DC brushless motor inspection without the need for a device.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a brushless motor inspection drive device according to an embodiment of the present invention, FIG. 2 is a waveform diagram inside the brushless motor drive device when the brushless motor is rotating normally, and FIG. 3 is the same waveform diagram. FIG. 4 is a waveform diagram inside the drive device when the brushless electric motor is rotating in reverse. 5... Rotation pulse output circuit, 6...1. , transistor switching circuit, 9... drive device for brushless motor inspection, 1o... brushless motor. Name of agent: Patent attorney Toshio Nakao and 1 other person
2 Figure e Figure 3 ξ □

Claims (1)

[Claims] A drive device for testing a DC brushless motor, characterized in that the drive device for testing a DC brushless motor incorporates a signal output circuit that determines the rotational direction of the motor and generates a DC pulse in synchronization with the rotation of the motor.