JP2000125592A - Drive for motor and radiator cooling system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive for motor capable of attaining cost reduction in a circuit, and provide the drive for motor and a radiator cooling system which can reduce the number of harnesses connected to the motor. SOLUTION: The data from the sensor S1 of a motor 2 is read by a logic circuit 4 through harnesses A1 to A3. The timing of a switching circuit in a drive circuit 6 is controlled, so that the rotational speed of the motor 2 becomes a preset rotational speed from the data. In the drive circuit 6, the motor 2 and a motor 3 without sensors are connected, in parallel through harnesses B1 to B3 to deliver drive current to the motors 2, 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor driving device, and more particularly to a radiator cooling system for an automobile using the driving device.

[0002]

2. Description of the Related Art An electric fan for cooling a radiator of an automobile is blown in a direction expanding with respect to an axis in a single case, resulting in poor cooling efficiency. Must be increased, resulting in vibration and noise.

[0003] In recent years, dual fan motors have been implemented in order to solve the above-mentioned drawbacks.
Two fans are juxtaposed and the directions of rotation are reversed to achieve efficient cooling. In this case, since the amount of air blown to the object to be cooled is greatly increased, the rotation speed of each fan motor can be reduced, and as a result, low vibration and low noise can be realized.

FIG. 3 shows such a radiator cooling system of the dual fan motor type. The radiator cooling system includes a power supply 1 for supplying electric power, a motor 2 having a rotor position detection sensor S1 for detecting a rotor position and rotating a fan F1, and a rotor position detection sensor S2 for similarly detecting a rotor position. A motor 3 for rotating the fan F2; a logic circuit 4 supplied with power from the power supply 1 and connected to the rotor position detection sensor S1; and a power supply supplied from the power supply 1 and the rotor position detection sensor S2. , A drive circuit 6 for flowing a drive current for operating the motor 2, and a drive circuit 7 for flowing a drive current for operating the motor 3. The logic circuits 4 and 5 and the drive circuits 6 and 7 constitute a motor driving device 8.

In such a radiator cooling system, the logic circuit 4 detects the rotation speed of the motor 2 based on sensor signals input from the rotor position detection sensor S1 through the harnesses A1 to A3, and the detected rotation speed is used by the user. Drive circuit 6 so that
Controls the drive current sent to the motor 2 through the harnesses B1 to B3. The logic circuit 5 detects the rotation speed of the motor 3 based on the sensor signals input from the rotor position detection sensor S2 through the harnesses A4 to A6, and drives the motor 3 so that the detected rotation speed becomes the speed set by the user. The drive current sent from the circuit 7 to the motor 3 through the harnesses B4 to B6 is controlled.

[0006]

As described above, in the conventional radiator cooling system of the dual fan motor type,
Since the logic circuits for controlling the rotation of the two motors are separately provided, it is necessary to connect the motors 2 and 3 to the logic circuits 4 and 5 separately.

For this reason, harnesses A1 to A3 connected between the rotor position detection sensor S1 of the motor 2 and the logic circuit 4 and sending sensor signals to the logic circuit 4, and between the rotor position detection sensor S2 of the motor 3 and the logic circuit 5 Harnesses A4 through to which sensor signals are sent to the logic circuit 5
A6 was required, and the number of harnesses increased.
Further, as described above, since the dedicated logic circuits 4 and 5 are used for the motors 2 and 3, respectively,
The cost of the circuit inside was high.

An object of the present invention is to provide a motor driving device in which the cost of the circuit is reduced. Also,
An object of the present invention is to provide a motor drive device and a radiator cooling system in which the number of harnesses connected to the motor is reduced.

[0009]

According to a first aspect of the present invention, there is provided a motor driving device for detecting a rotation speed of a first motor, wherein the first speed is detected in accordance with an output of the first speed detection device. And a drive circuit for generating a drive current for driving the second motor and also driving the second motor by the drive current.

A motor driving device according to a second aspect of the present invention includes a rotation speed detecting means for detecting a rotation speed of the first motor;
A first drive circuit for generating a drive current for driving the first motor in accordance with the output of the rotation speed detecting means; and a first drive circuit for driving a second motor in accordance with the output of the rotation speed detecting means. And a second drive circuit for generating a drive current.

According to a third aspect of the present invention, there is provided a radiator cooling system for mounting the motor driving device according to the first or second aspect outside an engine room, and for cooling the radiator on a rotating shaft of each of the motors. Wear the fan,
Storing the motor and the fan in an engine room,
In order to rotate the fan, a drive current is supplied to the motor from a driving device of the motor via a harness.

A radiator cooling system according to a fourth aspect is the radiator cooling system according to the third aspect, wherein the number of blades of a fan attached to the first motor and the second motor is the same. The size of the blade of the fan attached to the second motor is set to be smaller than the size of the blade of the fan attached to the first motor.

A radiator cooling system according to a fifth aspect of the present invention is the radiator cooling system according to the third aspect, wherein the shape and size of the blades of the fans attached to the first motor and the second motor are the same. At one time, the number of blades of the fan attached to the second motor is set to be smaller than the number of blades of the fan attached to the first motor.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a cooling system including a motor driving device used in the present embodiment.

The radiator cooling system using the motor driving device according to the present embodiment includes a power supply 1 for supplying electric power, and a rotor position detection sensor S for detecting the position of the rotor.
1, a three-phase DC motor 2 for rotating the fan F1
A three-phase DC motor 3 for rotating a fan F2, a logic circuit 4 supplied with power from the power supply 1 and connected to the rotor position detection sensor S1, and a drive current for operating the motors 2 and 3 And a drive circuit 6 for flowing. Therefore, the motor driving device 8
Is composed of a logic circuit 4 and a drive circuit 6. In this cooling system, the motor driving device 8 is mounted outside the engine room, and the motors 2, 3 and the fans F1, F2 are housed in the engine room for cooling the radiator.

In the cooling system having such a configuration,
When the motor 2 is driven, the logic circuit 4 uses a sensor signal transmitted from the rotor position detection sensor S1 installed in the motor 2 through the harnesses A1 to A3, and the logic circuit 4 uses the sensor signal.
The phase difference between the rotation speed of the rotor (not shown) rotating in the inside and the rotating magnetic field is detected. Further, the logic circuit 4
Then, the rotational speed of the rotor detected as described above is relatively compared with a preset rotational speed, and the drive current output from the drive circuit 6 is controlled so that the rotor rotates at the preset rotational speed. . Specifically, the ON / OFF timing of an output switch provided in the drive circuit 6 is controlled. The logic circuit 4 calculates a load on the fan F1 rotated by the motor 2 based on the simultaneously detected phase shift of the rotor, and outputs a drive current having an output level corresponding to the load. The circuit 6 is controlled.

As described above, the drive circuit 6 controlled by the logic circuit 4 includes a bridge circuit (not shown) composed of switching elements such as FETs and bipolar transistors, and the harness B1 is provided by the bridge circuit. ON / OFF operation of the drive current output to each of B3 to B3. In this way, by turning on / off the drive current, the motors 2 and 3 connected to the harnesses B1 to B3 respectively allow the drive current to flow through the two-phase coils among the three phases and also cause the remaining one-phase coils to receive the drive current. It operates in such a relationship that no drive current flows.
The drive circuit 6 is turned ON / OFF at the timing set by the logic circuit 4 so that the drive current does not flow through the three-phase coils in the motors 2 and 3 in order, so that the By deflecting the magnetic field, the rotor is rotated at a set rotational speed.

In the drive circuit 6, a drive current corresponding to the load applied to the fan F1 can be supplied to the motor 2 by a signal input from the logic circuit 4. At this time, a drive current corresponding to the load applied to the fan F1 is also supplied to the motor 3 connected to the drive circuit 6 in parallel with the motor 2 as in the case of the motor 2. Therefore, the load on the fan F2 is
When the load becomes larger than the load applied to 1, the phase shift of the motor 3 with respect to the rotating magnetic field of the rotor may not be eliminated because the motor 3 is not feedback-controlled by the logic circuit 4 like the motor 2.

Therefore, in order to improve the starting characteristics of the motor 3, the load on the fan F2 rotated by the motor 3 is always made lighter than the load on the fan F1. Therefore, the fan F1 and the fan F2
When a blade having the same shape is attached to the
Set the number of blades to 7 and set the number of blades for fan F2 to 5
The number of blades attached to the fan F2 is set to be smaller than the number of blades attached to the fan F1 so that the number of blades is set to one. When the same number of blades are attached to the fan F1 and the fan F2, the size of the blade attached to the fan F2 is set to be smaller than the size of the blade attached to the fan F1.

In the present embodiment, a motor having the rotor position detecting sensor S1 is used as the motor 2, but a sensorless motor having no rotor S1 may be used. At this time, the harness A1
The voltage induced in the one-phase coil in which no current flows among the three-phase coils of the motor 2 through A3 is sent to the logic circuit 4 as a signal. A technique for detecting the rotation speed of such a sensorless motor is described in, for example, Japanese Patent Publication No. 6-22390.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a block diagram illustrating a radiator cooling system including a motor driving device used in the present embodiment.

The cooling system using the motor driving device according to the present embodiment includes a power supply 1 for supplying electric power, a motor 2 having a rotor position detecting sensor S1 for detecting the position of the rotor and rotating the fan F1, and a fan F2. , A logic circuit 4 supplied with power from the power supply 1 and connected to the rotor position detection sensor S1, and a drive circuit for supplying a drive current under the control of the logic circuit 4 to operate the motor 2. 6 and
And a drive circuit 7 for flowing a drive current under the control of the logic circuit 4 to operate the motor 3. The motor driving device 8 includes a logic circuit 4 and drive circuits 6 and 7. In this cooling system, the motor driving device 8 is mounted outside the engine room, and the motors 2, 3 and the fans F1, F2 are housed in the engine room for cooling the radiator.

In the cooling system having such a configuration,
Similar to the first embodiment, when the motor 2 is driven, a sensor signal transmitted from the rotor position detection sensor S1 installed in the motor 2 through the harnesses A1 to A3 is used.
The logic circuit 4 detects a rotational speed of a rotor (not shown) rotating in the motor 2 and a phase shift with respect to a rotating magnetic field. Further, the logic circuit 4 makes a relative comparison between the rotation speed of the rotor detected as described above and the set rotation speed, and the drive circuits 6 and 7 control the rotation of the rotor at the set rotation speed. The ON / OFF timing of the output drive current is controlled. The logic circuit 4 calculates a load on the fan F1 rotated by the motor 2 based on the simultaneously detected phase shift of the rotor, and outputs a drive current having an output level corresponding to the load. The circuits 6 and 7 are controlled.

As described above, the drive circuits 6 and 7 controlled by the logic circuit 4 include therein a bridge circuit (not shown) including a switching element such as an FET or a bipolar transistor. An ON / OFF operation of the drive current output to each of the harnesses B1 to B6 is performed. By performing the ON / OFF operation of the drive current in this manner, the harness B
The motors 2 and 3 connected to the harnesses B1 to B3 and the harnesses B4 to B6 operate so that the drive current flows through the two-phase coils of the three phases and the drive current does not flow through the remaining one-phase coils. . The drive circuits 6, 7 are turned ON / OF at the timing set by the logic circuit 4.
F control so that the drive current does not flow through the three-phase coils in the motors 2 and 3 in order, so that the motors 2 and 3
By deflecting the magnetic field in 3, the rotor is rotated at a set rotational speed.

Further, the drive circuit 6 can supply the motor 2 with a drive current of an output level corresponding to the load applied to the fan F1 by a signal input from the logic circuit 4. At this time, similarly to the motor 2, a drive current whose output level is changed according to the load on the fan F1 is also supplied from the drive circuit 7 to the motor 3 connected to the drive circuit 7. Therefore, when the load on the fan F2 is larger than the load on the fan F1, the phase shift of the motor 3 with respect to the rotating magnetic field of the rotor of the motor 3 is not performed because the motor 3 is not feedback-controlled by the logic circuit 4 as in the motor 2. May not be resolved.

Therefore, similarly to the first embodiment, the motor 3
Fan F1 and fan F
In the case where the blades of the same shape are attached to
The number of blades attached to the fan F2 is made smaller than the number of blades attached to the fan F1 so that one blade is set to seven and five to the fan F2, so that the load on the fan F2 is reduced. When the same number of blades are attached to the fan F1 and the fan F2, the size of the blade attached to the fan F2 is set to be smaller than the size of the blade attached to the fan F1 to reduce the load applied to the fan F2. .

In this embodiment, a motor having a rotor position detecting sensor is used for the motor 2 as in the first embodiment, but a sensorless motor having no such sensor is used. May be used.

[0028]

According to the motor driving device of the present invention, the logic circuit as the rotation speed detecting means for detecting the rotation speed of the motor is different from the conventional motor driving device.
Since the configuration is such that one is eliminated, it is possible to reduce the cost of the circuit in the drive device of the motor.

According to the motor driving device of the second aspect, the drive circuits for driving the first motor and the second motor are each configured as a separate drive circuit. When an abnormality occurs, the first motor can be continuously driven in a state where the second motor is disconnected.

According to the radiator cooling system of the present invention, the logic circuit in the drive unit of the motor used in the radiator cooling system is deleted from the conventional one, so that it is mounted outside the engine room. It is possible to reduce the number of harnesses connecting the drive device for the motor and the motor housed in the engine room.

According to the radiator cooling system of the fourth aspect, the size of the blade of the fan attached to the second motor is smaller than the size of the blade of the fan attached to the first motor. Since the load on the second motor is less than the load on the first motor, the second motor
The starting characteristics of the motor are improved.

According to the radiator cooling system of the fifth aspect, the number of blades of the fan attached to the second motor is made smaller than the number of blades of the fan attached to the first motor. Since the load on the motor is less than the load on the first motor, the starting characteristics of the second motor are improved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a radiator cooling system according to a first embodiment.

FIG. 2 is a block diagram showing a configuration of a radiator cooling system according to a second embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional radiator cooling system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power supply 2, 3 Motor 4, 5 Logic circuit 6, 7 Drive circuit 8 Motor drive device A1-A6 Harness B1-B6 Harness S1, S2 Rotor position detection sensor F1, F2 Fan

Claims (5)

[Claims] A rotational speed detecting means for detecting a rotational speed of a first motor; a drive current for driving the first motor in accordance with an output of the rotational speed detecting means;
And a drive circuit for driving the second motor also by the drive current. 2. A rotation speed detection means for detecting a rotation speed of a first motor, and a first drive circuit for generating a drive current for driving the first motor in accordance with an output of the rotation speed detection means. And a second drive circuit for generating a drive current for driving a second motor in accordance with an output of the rotation speed detecting means. 3. The motor drive device according to claim 1 or 2 is mounted outside an engine room, and a fan for cooling a radiator is mounted on a rotating shaft of each of the motors. A radiator cooling system, wherein a drive current is supplied from a drive device of the motor to the motor via a harness in order to house the fan in an engine room and rotate the fan. 4. When the number of blades of the fan attached to the first motor and the second motor is the same, the size of the blade of the fan attached to the second motor is changed to the first motor. The radiator cooling system according to claim 3, wherein the radiator cooling system is set to be smaller than a size of a blade of a fan attached to the motor. 5. When the shape and size of the blades of the fan attached to the first motor and the second motor are the same, the number of blades of the fan attached to the second motor is reduced to the first number. 4. The number of blades of the fan attached to the motor is set to be smaller than the number of blades.
The radiator cooling system according to 1.