JPS63234886A - Low-speed high-torque motor - Google Patents

Abstract

PURPOSE:To enhance the stability of a circuit and miniaturize an equipment and contrive a performance to be easily regulated, by setting a controlling circuit having a function for correcting a rotor position and current command phase in digital system. CONSTITUTION:A low-speed and high-torque motor 1 is provided with and is composed of a speed detecting encoder 5 consisting of an encoder rotary- section 5a and an encoder sensor section 5b, and a controlling circuit 6. The rotary section 5a is fixed on a shaft A, and reference pulse signal and incremental signal are recorded. These signals are read out by the sensor section 5b and are transmitted to the controlling circuit 6. The incremental signal is gradually multiplied by four in the circuit 6 and is transmitted to a phase correcting section and a speed controlling section. At the phase correcting section, with a DIPSW, a counter set-value is changed, and an input incremental-pulse number to reference pulse and an output count number are changed, and phase is corrected. In the meantime, the position of a rotor 3a and current command phase are corrected by phase-matching the induced voltage signal of a stator coil 2b and controlling circuit current command with the DIPSW.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a low-speed, high-torque motor, and in particular, it improves the stability of the circuit against disturbance noise and slight voltage fluctuations compared to the past, and also reduces the size of the equipment. At the same time, the performance WRm
The present invention relates to an improvement of a low-speed, high-torque motor that can easily perform the following operations.

[Conventional technology]

As a high torque motor for robots, it was first developed in Japanese Patent Application Laid-Open No. 59
A motor described in Japanese Patent No. -63974 has been proposed.

The motor described in the publication has teeth on the rotor and stator, and by arranging the stator on the inner and outer peripheries of the rotor, it is possible to obtain a very large torque.

By the way, the present inventors have proposed a motor for office equipment such as copying machines, which outputs high torque that cannot be obtained with conventional DC motors, as shown in Figs. 3 and 4, although it does not require as much torque as for robots. We have developed motors.

That is, FIG. 3 is a control block diagram of a conventional low-speed high-torque motor, and FIG. 4 is a partially vertical front view of a motor incorporating the control system shown in FIG. 3. 1 is the general term for motor, 2a is the stator, 2b
is a stator coil, 3a is a rotor, 3b is a rotor magnet, 4 is a shaft, 5 is a speed detection encoder, 5a
5b is a part of the encoder sensor, 6 is the encoder rotating part, and 5b is the encoder sensor part.
7 is a control circuit, 7 is a rotor position detector, 7a is a position detection sensor, 7b is a position detection rotor magnet, and 7c is a sensor coil. Stepping motors are installed on the inner periphery of the stator 2a and the outer periphery of the rotor 3a, respectively. It has teeth like this.

[Problem that the invention seeks to solve]

However, the conventional low-speed, high-torque motors shown in FIGS. 3 and 4 have the following problems.

That is, in the low-speed high-torque motor shown in FIGS. 3 and 4, (1) due to the rotation of the position detection rotor magnet part 7b,
The induced voltage generated in the sensor coil 7C is integrated, and this is used as the current command for the control circuit 6. Conventionally, the integrator output, that is, the current command offset level, fluctuates due to slight noise or fluctuations in the control section voltage. There was a problem that the control state of the motor 1 became unstable.

(2) Also, in the conventional case, as shown in FIG.

It is necessary to arrange the dedicated rotor position detector 7 in series with the motor 1, which increases the axial length of the motor 1 as a whole, which is a cause of hindering miniaturization of the motor 1.

(3) Furthermore, conventionally, the position of the rotor 3a and the induced voltage phase of the sensor coil 7c are determined by manual positioning when the stators (2a, 7a) of the motor part and the sensor part are assembled into the housing. However, accurate positioning cannot be achieved with this alone, so in addition to incorporating a phase correction circuit into the control circuit 6, phase correction is performed by changing the sum of the two-phase integrator outputs. However, since the output of the motor 1 changes due to this phase correction, an output correction is further required to make the output value of the motor 1 constant.

The present invention was made as a result of studies to solve the problems of the prior art described above, and its purpose is to improve the stability of the circuit against disturbance noise and slight voltage fluctuations compared to the prior art. At the same time, we aim to increase the size of equipment and reduce the size of equipment.
The present invention aims to provide an improved low-speed, high-torque motor whose performance can be easily adjusted.

[Means for solving problems]

In order to achieve the above object, a low speed high torque motor according to the present invention includes a motor section, a speed detection encoder, and a control circuit, and the encoder has a reference signal generation function according to the number of rotor poles, Furthermore, the control circuit has a function of making the ratio of the number of encoder reference signals and the number of incremental signals per rotation of the rotor into an integer, and the control circuit has a function to set the ratio of the number of encoder reference signals and the number of incremental signals per rotation of the rotor to an integer. Set the number of divisions according to the previous encoder signal ratio,
It is characterized by having a function of digitally correcting the rotor position and current command phase.

That is, in the present invention.

(1) A digital quantity written in memory in advance.

The speed detection encoder pulse is used to read out the rotor position, and this is DA-converted and used as a current command.

(2) In addition, in the present invention, the reading reference position of the current command digitally written in the memory in advance can be determined by adding a pulse generation function of the same number as the rotor peak per rotation to the speed detection encoder. can get.

(3) Furthermore, in the present invention, the relationship between the rotor position and the current command phase can be matched by digitally correcting the memory recording signal readout phase with respect to the reference pulse using an external dip switch.

[Effect]

According to one aspect of the present invention, according to the configuration (1) described in the section [Means for solving the problem], the current command is digitally recorded in the memory in advance.
A stable command value can be obtained without changing due to external noise or slight voltage fluctuations. On the other hand, by adopting the above-mentioned configuration, the present invention provides a current command original signal generation function of the rotor position detection function and current command original signal generation function that are required in conventional low-speed high-torque motors. No longer needed.

The present invention also relates to the same paragraph [Means for solving the problems]
According to the description in item (2), since a reference signal corresponding to the rotor position can be obtained from the speed detection encoder, the rotor position detection sensor itself becomes unnecessary, and the motor can be made smaller in the axial direction.

Furthermore, according to the description in item (3) of the same item [Means for solving the problem], the present invention not only adjusts the correlation between the rotor position and the current command phase, but also allows the adjustment to be limited to Since only the phase is corrected and there is no level change, there is no need for a conventional output correction circuit to adjust the correlation between the rotor position and the current command phase.

〔Example〕

Hereinafter, the present invention will be explained based on an embodiment shown in FIGS. 1 and 2. FIG. 1 is a control block diagram most characteristically representing the low-speed high-torque motor according to the present invention, and FIG. 2 is a partially vertical front view of a motor incorporating the control system shown in FIG. 1. FIG.

In FIGS. 1 and 2, the same reference numerals as those of the conventional low-speed high-torque motor shown in FIGS. 3 and 4 refer to the same parts.
In other words, 1 is a general term for motors.

2a is a stator, 2b is a stator coil, 3a is a rotor, 3b is a rotor magnet, 4 is a shaft, 5 is a speed detection encoder, 5a is an encoder rotation part, 5b is a part of an encoder sensor, 6 is a control circuit, and the stator 2a
The inner periphery of the rotor 3a and the outer periphery of the rotor 3a each have teeth like a stepping motor, and in the case of this embodiment, the number of rotor teeth of the two-phase motor shown in the drawings is 90. The rotating part 5a of the speed detection encoder 5 is rigidly fixed to the shaft 4, and the encoder rotating part 5a receives a reference pulse signal of 90 per rotation and an incremental signal (2520) which is an integral multiple of the reference pulse signal and which is sufficiently larger than the reference pulse signal (2520). is recorded. Then, the two types of signals are read out by the encoder sensor part 5b and sent to the control circuit 6. The incremental signal is multiplied by 4T in the control circuit 6 and sent to the speed control section and phase correction section as shown in FIG.
In the phase correction section, the number of input incremental pulses and the number of output counts relative to the reference pulse can be changed by changing the counter setting value using the DIPSW, thereby making it possible to perform phase correction. In FIG. 1, the memory stores a half-wave sine wave at the ratio of the encoder incremental signal to the reference signal (252 in the example).
An approximate digital amount divided by 0/90X4=112) is recorded, and this recorded value is read out according to the output count number of the phase correction section, and is DA-converted and used as a current command.

On the other hand, the position of the rotor 3a and the current command phase can be corrected by externally driving each motor and transmitting the induced voltage signal generated in the stator coil 2b and the control circuit current command to a synchroscope or the like. This is done by displaying the signal and adjusting the phase using DIPSW.

The present invention has the above-mentioned configuration, and although some parts overlap with the above description, the effects of the present invention will be summarized as follows: (1) Digital data written in memory in advance The amount is read out according to the position of the rotor 3a using encoder pulses for speed detection, and this is converted from D to A to be used as a current command. That is, according to the present invention, since the current command is digitally recorded in the memory in advance, a stable command value can be obtained without being changed by external noise or slight voltage fluctuations. On the other hand, by adopting the above-mentioned configuration, the present invention provides a current command original signal generation function of the rotor position detection function and current command original signal generation function that are required in conventional low-speed high-torque motors. No longer needed.

(2) In addition, in the present invention, the read reference position of the current command digitally written in the memory in advance adds a pulse generation function to the speed detection encoder 5 for the same number as the number of rerotor poles per rotation. This can be done by That is, according to the present invention, since a reference signal corresponding to the position of the rotor 3a is obtained from the speed detection encoder 5, the rotor position detection sensor itself becomes unnecessary, and the motor 1 can be made smaller in the axial direction. I can do it,
According to the prototype, the axial length of the product could be reduced by about 10 to 15%.

(3) Furthermore, in the present invention, the relationship between the position of the rotor 3a and the current command phase can be matched by digitally correcting the memory recording signal readout phase with respect to the reference pulse using an external dip switch.

That is, according to the present invention, not only is the correlation between the position of the rotor 3a and the current command phase adjusted, but the adjustment is only a phase correction and there is no level change.
A conventional output correction circuit is not required to adjust the correlation between the position of the rotor 3a and the current command phase.

In addition, in this embodiment, the information written to the memory of the two-phase motor does not necessarily have to be two types, SIN and CO5, but the information written to the memory may be SIN only, and the CoS may be created by a phase correction circuit. The advantage is that when assembling the motor, there is no confusion in work due to the use of two types of memory with the same appearance.

[Invention is effective]

The present invention is as described above, and as is clear from the explanation of the illustrated embodiments, according to the present invention, the stability of the circuit against disturbance noise and slight voltage fluctuation is increased compared to the conventional one, and the stability of the equipment is improved. It is possible to obtain an improved low-speed, high-torque motor that is smaller in size and whose performance can be easily adjusted.

[Brief explanation of the drawing]

1 to 2 show one embodiment of the present invention, FIG. 1 is a control block diagram most characteristically representing the low speed high torque motor according to the present invention, and FIG. 2 is a control block diagram shown in FIG. 1. Fig. 3 is a control block diagram of a conventional low-speed high-torque motor; Fig. 4 is a partially longitudinal front view of a motor incorporating the control system shown in Fig. 3; be. DESCRIPTION OF SYMBOLS 1...Motor, 2a...Stator, 2b...Stator coil, 3a...Rotor, 3b...Rotor magnet, 4...Shaft, 5...Encoder for speed detection, 5a... - Encoder rotating part, 5b... Part of encoder sensor, 6... Control circuit. C

Claims (1)

[Claims] 1. It has a motor part, an encoder for speed detection, and a control circuit, and the encoder has a reference signal generation function according to the number of rotor poles, and furthermore, the number of encoder reference signals and the number of incremental signals per rotor rotation. The control circuit has a function to set the ratio of the sine wave current command to an integer, and the control circuit has a function to set the number of sine wave divisions of the memory for generating a sine wave current command placed in the control circuit to a number corresponding to the previous encoder signal ratio, and A low-speed, high-torque motor characterized by having a function to digitally correct the position and current command phase.