JP2003154188A - Washing machine having dc brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of input terminals of a microcomputer to be occupied by signal lines from the output terminals of sensor circuit by reducing connections between the output terminals of the sensor circuits and the microcomputer by transmitting rotor position information which is acquired in the output terminals of the plurality of sensor circuits, through a single signal line in a washing machine having a DC brushless motor equipped with the plurality of sensor circuits for detecting the position of a rotor. SOLUTION: A resistor 18 is connected to a power source 17 for a sensor circuit in each of a plurality of sensor circuits 11, 12 and 13 for detecting the rotor position of the DC brushless motor, and resistors 14, 15 an 16 having different resistance values are connected between the other terminal of this resistor 18 and the respective output terminals of the sensor circuits 11, 12 and 13. In the resistors 14, 15 and 16, the parallel resistance values of arbitrary two resistors are different from the resistance value of the other resistor depending on the combination of high and low voltages outputted from the sensor circuits 11, 12 and 13 and the voltage in the joining paint between the resistor 18 and the resistors 14, 15 and 16 is defined as rotor position detection output.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing machine having a DC brushless motor equipped with a plurality of sensor circuits for detecting a rotor position.

[0002]

2. Description of the Related Art In recent years, a washing and dewatering tub constituting a washing machine,
Further, a mainstream is one in which a DC brushless motor drives an agitating blade rotatably provided on the inner bottom portion of the washing / dehydrating tub.

In this DC brushless motor, the rotor is composed of a permanent magnet, has a sensor circuit for detecting the position of the rotor, and is driven by an inverter circuit.

Conventionally, a sensor circuit for detecting the rotor position of a DC brushless motor of this type has been constructed as shown in FIG. The configuration will be described below.

As shown in FIG. 3, when the DC brushless motor has three phases and eight poles, three sensors are used, and three sensor circuits 1, 2 and 3 output the output as shown in FIG. 4 in accordance with the rotation of the rotor. Is getting Incidentally, the sensor usually obtains a high or low output as shown in FIG. 4 by adding an electronic circuit to the sensor. Here, the sensor and its electronic circuit will be referred to as a sensor circuit. The drive coil of the DC brushless motor is driven according to the timing and level of the output level change of the sensor circuits 1, 2, and 3.

The sensor circuits 1, 2, 3 are composed of Hall ICs that output high and low signals.
The output of is often configured so that the collector of the transistor is opened (hereinafter referred to as an open collector). Therefore, the resistors 4, 5, and 6 are connected to the outputs of the sensor circuits 1, 2, and 3 to be connected to the sensor circuit power supply 7, and outputs are obtained from the output terminals of the sensor circuits 1, 2, and 3.
The outputs of the three sensor circuits 1, 2 and 3 are input to the microcomputer 8 and are calculated in the microcomputer 8 to output control signals from the output of the microcomputer 8 to the motor drive circuit and the motor 9.

The sensor circuits 1, 2, and 3 are on a first printed circuit board (not shown) arranged near the rotor of the motor, and the output of each sensor circuit 1, 2, and 3 is from the motor. Is often connected by a lead wire to a second printed circuit board (not shown) at a remote position.

Since the motor is attached to the washing / dehydrating tub, mechanical vibration is constantly generated during the washing operation. When the printed circuit board on which the components are mounted is fixed to the motor, the components themselves are vibrated due to the vibration. Since the reliability of the printed circuit board will be reduced due to vibrations such as the occurrence of defective products or pattern breaks in the soldered parts of the parts, place the printed circuit board in a vibration-free place to prevent it from being adversely affected by vibrations. ing.

The minimum required sensor circuits 1, 2,
Only 3 is mounted on the printed circuit board and directly attached to the motor.

[0010]

However, in the above-described conventional configuration, the sensor circuits 1, 2, and 3 have three outputs, and in order to input them to the microcomputer 8,
Three terminals were required as inputs to the microcomputer 8, and three lines were required to connect the output terminals of the sensor circuits 1, 2, 3 and the input terminals of the microcomputer 8.

Therefore, many input terminals of a circuit for receiving a sensor signal such as the microcomputer 8 are occupied, and
Since 3 lines are required to connect the printed circuit boards, a large number of lead wires and terminals for the connector connecting the lead wires and the printed circuit board are required. Moreover, the connectors are those that realize electrical connection by contact. Therefore, there are problems that the fact that there are many contact points basically includes the cause of the defect.

The present invention is to solve the above-mentioned conventional problems, and transmits rotor position information obtained at the output terminals of a plurality of sensor circuits using a single signal line, and the output terminals of the sensor circuits and a microcomputer. It is intended to reduce the number of connections between terminals and the number of occupied input terminals of a microcomputer.

[0013]

To achieve the above object, the present invention connects a resistor to a sensor circuit power source of a plurality of sensor circuits for detecting the rotor position of a DC brushless motor, and connects the resistor to the other end of the resistor. It is configured such that a plurality of resistors having different resistance values are connected to the respective output terminals of the sensor circuit, and the plurality of resistors can be connected to any two resistors depending on the combination of the high and low voltages of the output of the sensor circuit. The rotor position detection output is the voltage at the connection point between the resistance connected to the power supply for the sensor circuit and the resistance connected to the output terminal of the sensor circuit, with the parallel resistance value and the resistance value of other resistances being different. .

Thus, the rotor position information obtained at the output terminals of the plurality of sensor circuits can be transmitted by using the single signal line, and the connection between the output terminals of the sensor circuit and the microcomputer can be reduced. Therefore, the number of occupied input terminals of the microcomputer can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention comprises a plurality of sensor circuits for detecting the rotor position of a DC brushless motor, a sensor circuit power supply, and a resistor connected to the sensor circuit power supply. , A plurality of resistors having different resistance values connected between the other end of the resistor and each output terminal of the sensor circuit, the plurality of resistors being a combination of high and low voltages of the output of the sensor circuit. To make the parallel resistance value of any two resistors different from the resistance value of the other resistor, and the connection point between the resistor connected to the sensor circuit power supply and the resistor connected to the output terminal of the sensor circuit respectively. The voltage is used as the rotor position detection output, and the rotor position information obtained at the output terminals of multiple sensor circuits can be transmitted using a single signal line. Black can be reduced connections between computers, it is possible to reduce the occupation numbers of the input terminals of the microcomputer.

According to a second aspect of the present invention, a plurality of sensor circuits for detecting the rotor position of the DC brushless motor, a sensor circuit power source, a resistor connected to the sensor circuit power source, and the other end of the resistor are provided. A resistor connected between each of the output terminals of the sensor circuit so that the parallel resistance value of any two resistors and the resistance value of another resistor are different by a combination of high and low voltages of the output of the sensor circuit. A first printed circuit board on which a plurality of resistors having different values, a resistor connected to the sensor circuit and a power source for the sensor circuit, and a plurality of resistors connected to an output terminal of the sensor circuit are mounted, and the power source for the sensor circuit And a lead wire connecting the first printed circuit board and the second printed circuit board, the power source for the sensor circuit on the second printed circuit board. The voltage at the connection point between the connected resistors and the multiple resistors connected to the output terminal of the sensor circuit is used as the rotor position detection output, and the output voltage of the multiple sensor circuits can be a single signal voltage. The output signal line of the sensor circuit between the first printed board and the second printed board can be single.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) As shown in FIG. 1, sensor circuits 11, 12, 13 detect the position of a rotor constituted by a permanent magnet of a DC brushless motor (not shown) for driving a washing machine. Then, a high or low level signal is output to that output. Resistance 14, 1
Reference numerals 5 and 16 are connected to the output terminals of the sensor circuits 11, 12 and 13, respectively. Then, these have different resistance values, and the parallel resistance values of arbitrary two resistors and the resistance values of other resistors, which are generated by a combination of high and low voltages generated by the sensor circuits 11, 12, and 13 outputs. Are different.

The resistor 18 has a sensor circuit power source 17 at one end.
And the other end is connected to the other ends of the resistors 14, 15, 16 and this connection point is referred to as point A.

The operation of the above configuration will be described. The outputs of the sensor circuits 11, 12, and 13 output high and low levels in accordance with the rotation of the DC brushless motor, as described in the conventional example and shown in FIG. In other words, there are three states in which any one is low, or three states in which any two are low, and a total of six different states are output, and these six states are output according to the rotation of the rotor. Individual states occur repeatedly.

Here, the voltage generated at the point A corresponds to the voltage of the sensor circuit power supply 17 and the resistance 18 and the resistances 14, 15 and 16.
The value is divided by the resistance value of any one of the resistors or the resistance value of the parallel resistor of the two resistors. Resistors 14, 15, 1
Since 6 is a different resistance value, and the parallel resistance value of the two resistors and the resistance value of the other one resistor are also different values, the generated voltages in the six states do not become the same voltage and are different from each other. Voltage.

As a result, the three sensor circuits 11, 1
The output voltages of 2 and 13 can be different voltages at a single point at point A, and the resistor 18 connected to the sensor circuit power supply 17 and the resistor 14 connected to the output terminals of the sensor circuits 11, 12, and 13, respectively, Connection point with 15 and 16 (A
Point) voltage can be used as the rotor position detection output, and the rotor position information obtained at the output terminals of the sensor circuits 11, 12, 13 can be transmitted using a single signal line. The connection between the output terminals of 11, 12, and 13 and the microcomputer can be reduced, and the number of input terminals occupied by the microcomputer can be reduced.

(Embodiment 2) As shown in FIG. 2, the first printed circuit board 19 has sensor circuits 11, 12, 13 and resistors 14, 15, 16, 18 mounted thereon. The second printed circuit board 20 mounts the sensor circuit power supply 17. The lead wire 21 connects the sensor circuit power supply 17 and the resistor 18, and the lead wire 22 connects the negative side terminal of the sensor circuit power supply 17 and the negative side power supply terminals of the sensor circuits 11, 12, and 13. .

The lead wire 23 transmits point A onto the second printed circuit board 20, and the point transmitted point A onto the second printed circuit board 20 is referred to as point B. The motor control circuit 24 is composed of a circuit having a control signal generating unit such as a microcomputer in the input unit and a motor drive circuit in the output unit. 25 is a motor.

The operation of the above configuration will be described. The voltage at the point A can be taken out as the voltage at the point B on the second printed circuit board 20 through the lead wire 23. As a result, the sensor circuits 11, 12, 13 which are rotor position information
Output voltage can be transmitted to the second printed circuit board 20 by a single lead wire 23.

This signal is input to the motor control circuit 24 having a microcomputer or the like, and the motor control circuit 24
The calculation processing is carried out inside, and a control signal is output to the motor 25.

Normally, the sensor circuits 11, 12 and 13 are attached near the rotor in the motor, and since the motor is fixed to the washing / dehydrating tank, the sensor circuits 11, 12 and 13 are constantly vibrated.
The circuit for controlling and driving the motor based on the outputs of 2 and 13 is mounted on the second printed circuit board 20 which does not vibrate, so that the sensor circuit 11 from the point B, as in this embodiment,
By obtaining the outputs of 12 and 13, the plurality of signal lines from the sensor circuit output terminal, which are conventionally required, can be made into a single signal line, and the number of connection lines can be reduced.

[0028]

As described above, according to the first aspect of the present invention, the plurality of sensor circuits for detecting the rotor position of the DC brushless motor, the sensor circuit power supply, and the sensor circuit power supply are provided. And a plurality of resistors having different resistance values connected between the other end of the resistor and each output terminal of the sensor circuit, the plurality of resistors being a high output of the sensor circuit, Depending on the combination of the low voltages, the parallel resistance value of any two resistors is made different from the resistance values of the other resistors, and a resistor connected to the sensor circuit power supply and a resistor connected to the output terminal of the sensor circuit, respectively. Since the voltage at the connection point of is the rotor position detection output, the rotor position information obtained at the output terminals of the multiple sensor circuits can be transmitted using a single signal line,
It is possible to simplify the design by reducing the number of patterns in the printed circuit board design and reduce the cost by reducing the area of the printed circuit board. Also, conventionally, it was necessary to have multiple input terminals for the circuit that receives the rotor position detection signal. Since the number of input terminals is single, the number of input terminals can be reduced, the number of circuits can be reduced, and thus the price can be reduced. In addition, when the circuit that receives the signal is a microcomputer, the number of required terminals may increase due to the recent increase in functions. However, in such a case, an additional circuit may be added, or Although one microcomputer may be added, the present invention makes it possible to delete an additional circuit or to abolish another microcomputer, thereby reducing the cost of parts.

According to a second aspect of the invention, a plurality of sensor circuits for detecting the rotor position of the DC brushless motor, a power source for the sensor circuit, a resistor connected to the power source for the sensor circuit, and the resistor. Connected between the other end of the sensor circuit and each output terminal of the sensor circuit, and the parallel resistance value of any two resistors and the resistance value of another resistor differ depending on the combination of the high and low voltages of the output of the sensor circuit. A plurality of resistors having different resistance values, a resistor connected to the sensor circuit and the sensor circuit power supply, and a plurality of resistors connected to the output terminal of the sensor circuit, and a first printed circuit board, A second printed circuit board on which a power source for a sensor circuit is mounted; and a lead wire connecting the first printed circuit board and the second printed circuit board, and the sensor on the second printed circuit board is provided. Since the voltage at the connection point of the resistor connected to the circuit power supply and the plurality of resistors connected to the output terminal of the sensor circuit is the rotor position detection output, the output voltage of the plurality of sensor circuits should be a single signal voltage. The output signal line of the sensor circuit between the first printed circuit board and the second printed circuit board can be made single, and the first printed circuit board mounted with the sensor circuit arranged near the rotor of the motor is Since other circuits are not installed from the viewpoint of vibration, the rotor position information signal obtained from the sensor circuit is the second vibration-free signal.
Of the sensor circuit according to the present invention, wherein a control signal for motor control is created on the second printed circuit board based on the rotor position detection signal. By using a single signal line from, it is possible to reduce the number of lead wires and the connectors that connect the lead wires to the printed circuit board, and it is possible to reduce the number of parts and the printed circuit board area, thus reducing the price. can do. Further, the chance of contact failure of the connector connecting the lead wire and the printed circuit board is also reduced due to the decrease in the number, and the reliability can be improved.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a main part of a washing machine having a DC brushless motor according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a main part of a washing machine having a DC brushless motor according to a second embodiment of the present invention.

FIG. 3 is a circuit diagram of a main part of a washing machine having a conventional DC brushless motor.

FIG. 4 is an output waveform diagram of a sensor circuit of a washing machine having the same DC brushless motor.

[Explanation of symbols]

11 sensor circuit 12 sensor circuits 13 Sensor circuit 14 Resistance 15 Resistance 16 resistance 17 Sensor circuit power supply 18 Resistance

Claims (2)

[Claims] 1. A plurality of sensor circuits for detecting a rotor position of a DC brushless motor, a power source for the sensor circuit, a resistor connected to the power source for the sensor circuit, another end of the resistor and outputs of the sensor circuit. A plurality of resistors having different resistance values connected between the terminals and the plurality of resistors, wherein the plurality of resistors have a parallel resistance value of two arbitrary resistors and others depending on a combination of high and low voltages of the output of the sensor circuit. Washing having a DC brushless motor in which the resistance values of the resistors are different and the voltage at the connection point between the resistor connected to the sensor circuit power supply and the resistor connected to the output terminal of the sensor circuit is used as the rotor position detection output. Machine. 2. A plurality of sensor circuits for detecting the rotor position of a DC brushless motor, a sensor circuit power source, a resistor connected to the sensor circuit power source, the other end of the resistor and each output of the sensor circuit. A plurality of resistors having different resistance values, which are connected between the terminals and have a parallel resistance value of any two resistors different from a resistance value of other resistors by a combination of high and low voltages of the output of the sensor circuit; A first printed circuit board on which the sensor circuit and a resistor connected to the sensor circuit power source and a plurality of resistors connected to the output terminals of the sensor circuit are mounted; and a second printed circuit on which the sensor circuit power source is mounted. Substrate, first printed circuit board and second
A lead wire connected to the printed circuit board of
A washing machine having a DC brushless motor that uses a voltage at a connection point of a resistor connected to the power source for the sensor circuit and a plurality of resistors connected to the output terminal of the sensor circuit on the printed circuit board as a rotor position detection output.