Motor drive unit

Abstract

To provide a motor drive device capable of controlling switching of a rotation direction of a DC motor only with five lines that communicate with a main body control circuit and the motor drive device.SOLUTION: A motor drive device includes: a speed command value generation unit for generating a speed command value sp for giving instruction in rotation speed of a DC motor 3 from a speed command input VSP within a range of a lower threshold voltage to an upper threshold voltage; a speed command discrimination unit 44 for discriminating a rotation direction switching command included in the speed command input VSP based on an input pattern of the speed command input VSP exceeding a command discrimination threshold voltage higher than the upper threshold voltage; a rotation direction setting unit 45 for setting a rotation direction of the DC motor 3 to either a clockwise CW or a counterclockwise CCW and switching a set rotation direction when a rotation direction switching command is discriminated by the speed command discrimination unit 44; and a rotation control unit 47 for rotating the DC motor 3 in a rotation direction set by the rotation direction setting unit 45 at a rotation speed of the speed command value sp.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a motor drive device that is provided in a motor device having a motor and drives the motor based on an externally supplied power supply and control signals. [Background technology]

[0002] 4, a motor device 2 equipped with a motor drive device 4 that drives a DC motor 3 based on supplied power and control signals is used in various electrical appliances 1 (see, for example, Patent Document 1). The motor drive device 4 is provided in the motor device 2 as a semiconductor IC for driving a motor. The motor drive device 4 has terminals connected to the DC motor 3, such as a U-phase output U, a V-phase output V, a W-phase output W, a U-phase Hall element signal input HU, a V-phase Hall element signal input HV, and a W-phase Hall element signal input HW. The motor drive device 4 also has terminals for inputting and outputting power supplies and control signals, such as a DC power supply input VBB, a control circuit power supply input VCC, a ground connection COM, a speed command input VSP, a rotation speed detection output FG, and a rotation direction setting input signal CW / CCW.

[0003] There may be an agreement between a motor manufacturer that produces motor device 2 and a set manufacturer that produces electrical equipment 1 (main body control circuit 11) that uses the motor device, that signals are exchanged over a total of five wires to operate motor device 2. In such an agreement, the five wires are DC power supply input VBB, control circuit power supply input VCC, ground connection COM, speed command input VSP, and rotation speed detection output FG.

[0004] The five wires specified do not include the rotation direction setting input signal CW / CCW. Therefore, the rotation direction setting input signal CW / CCW is generally set when the motor drive semiconductor IC is mounted on the circuit board, and is used to fix the rotation direction of the DC motor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-312338 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, there has been a demand for the ability to control the switching of the rotation direction of the DC motor 3 by control on the side of the electric device 1 (main body control circuit 11).

[0007] An object of the present invention is to provide a motor drive device that can control switching of the rotation direction of a DC motor 3 using only five lines for communication between a main body control circuit 11 and a motor drive device 4. [Means for solving the problem]

[0008] A motor drive device of the present invention is a motor drive device that controls the rotational speed of a motor based on a speed command input, and is characterized by comprising: a speed command value generation unit that generates a speed command value that indicates the rotational speed of the motor from the speed command input within a range from a lower threshold voltage to an upper threshold voltage; a command discrimination unit that discriminates a rotation direction switch command included in the speed command input based on another command input pattern of the speed command input that exceeds a command discrimination threshold voltage that is higher than the upper threshold voltage; a rotation direction setting unit that sets the rotation direction of the motor to either clockwise or counterclockwise and switches the set rotation direction when the rotation direction switch command is discriminated by the command discrimination unit; and a rotation control unit that rotates the motor in the rotation direction set in the rotation direction setting unit at a rotational speed of the speed command value. [Effects of the Invention]

[0009] According to the present invention, it is possible to control the switching of the rotation direction of the DC motor 3 using the speed command input VSP included in the five signal lines that communicate between the main body control circuit and the motor drive device. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a block diagram showing a configuration of an embodiment of a motor drive device according to the present invention; [Figure 2] 2 is a block diagram showing the configuration of a speed command determination unit shown in FIG. 1. FIG. [Figure 3] FIG. 1 is a diagram showing an example of an input pattern of a speed command input VSP. [Figure 4] 1 is a block diagram showing an example of the configuration of an electrical device including a motor device; DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, components having similar functions will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0012] Referring to FIG. 1, the motor drive device 40 of this embodiment includes a power supply circuit 41, an inverter 42, a driver 43, a speed command determination unit 44, a rotation direction setting unit 45, a position estimation unit 46, and a rotation control unit 47.

[0013] The power supply circuit 41 is a voltage regulator that generates an internal power supply voltage from the control circuit power supply input VCC.

[0014] The inverter 42 includes bridge-connected switch elements, converts the DC power supply input VBB into AC driving power (U-phase output U, V-phase output V, W-phase output W), and supplies the converted driving power to the DC motor 3.

[0015] Referring to FIG. 2, the speed command determination unit 44 includes a speed command value generation unit 441 that generates a speed command value sp from a speed command input VSP, a voltage division circuit 442 that divides the speed command input VSP, and a voltage division circuit 443 that divides the voltage of the speed command input VSP and converts the voltage divided by the voltage division circuit 442 into a preset reference potential V ref and a command discrimination unit 444 that discriminates other commands included in the speed command input VSP based on the output of the comparator 443.

[0016] The rotation speed of the DC motor 3 is controlled by a speed command input VSP. The speed command value generator 441 generates a speed command value VSP based on a lower threshold voltage V spL ~Upper threshold voltage V spH The speed command input VSP within the range is AD converted to generate a speed command value sp that indicates the rotation speed of the DC motor 3, and the generated speed command value sp is output to the rotation control unit 47.

[0017] The comparator 443 detects whether the speed command input VSP is higher than the upper threshold voltage V spH Higher than the maximum rated voltage V H The command discrimination threshold voltage V is set to a value lower than th , the voltage divider circuit 442 outputs a Hi-level signal. ref The speed command input VSP is the command discrimination threshold voltage V th When the voltage exceeds this level, the comparator 443 outputs a Hi level signal.

[0018] The command discrimination unit 444 determines the output pattern of the Hi level signal output from the comparator 443, i.e., the command discrimination threshold voltage V th The command discriminator 444 discriminates other commands included in the speed command input VSP based on the input pattern of the speed command input VSP that exceeds the threshold value. Note that the discrimination by the command discriminator 444 is performed when the motor drive device 40 is started up.

[0019] As shown in FIG. 3(a), the command discrimination unit 444 determines whether the speed command input VSP is greater than or equal to the command discrimination threshold voltage V th and the Hi level signal output from the comparator 443 continues for a predetermined time Ta or more, the other command included in the speed command input VSP is determined to be a test mode command, and a test mode indication signal test is output to the rotation control unit 47.

[0020] 3(b), the command discriminator 444 determines whether the speed command input VSP is greater than or equal to the command discrimination threshold voltage V thIf the speed command input VSP periodically exceeds the predetermined value, and the Hi level signal output from the comparator 443 continues to be a pulse of a predetermined time Tb shorter than the predetermined time Ta for a preset number of times (for example, four times), the other command included in the speed command input VSP is determined to be a rotation direction switch command, and a rotation direction switch instruction signal switch is output to the rotation direction setting unit 45.

[0021] If the command discriminator 444 can discriminate between the test mode command and the rotation direction change command, the command discrimination threshold voltage V th There is no particular limitation on the input pattern of the speed command input VSP that exceeds the command discrimination threshold voltage V. For example, th The speed command input VSP may be distinguished by any one or a combination of the pulse width, duty, pulse amplitude, and number of pulses of the input pattern.

[0022] The rotation direction setting unit 45 sets the rotation direction of the DC motor 3 to either clockwise (CW) or counterclockwise (CCW). The rotation direction setting unit 45 switches the set rotation direction when a rotation direction switching instruction signal switch is input from the command discrimination unit 444. When the rotation direction is set to clockwise (CW), the rotation direction setting unit 45 switches the rotation direction to counterclockwise (CCW) when a rotation direction switching instruction signal switch is input, and when the rotation direction is set to counterclockwise (CCW), the rotation direction setting unit 45 switches the rotation direction to clockwise (CW).

[0023] Based on the U-phase Hall element signal input HU, the V-phase Hall element signal input HV, and the W-phase Hall element signal input HW input from the DC motor 3, the position estimation unit 46 estimates the position of the rotor relative to the stator of the DC motor 3 and outputs a position estimation signal to the rotation control unit 47.

[0024] In addition, the position estimation unit 46 generates a rotation speed detection output FG for monitoring the rotation speed of the DC motor 3 based on the U-phase Hall element signal input HU, the V-phase Hall element signal input HV, and the W-phase Hall element signal input HW input from the DC motor 3.

[0025] The rotation speed detection output FG generated by the position estimation unit 46 has two different specifications corresponding to the rotation direction (CW or CCW) of the DC motor 3 set in the rotation direction setting unit 45. For example, when the rotation direction setting unit 45 sets the rotation direction to clockwise (CW), the first specification of the rotation speed detection output FG is set to output four pulses per rotation of the DC motor 3. When the rotation direction setting unit 45 sets the rotation direction to counterclockwise (CCW), the second specification of the rotation speed detection output FG is set to output 12 pulses per rotation of the DC motor 3. Note that the two different specifications of the rotation speed detection output FG may be used as long as the rotation direction of the DC motor 3 can be determined by the equipment of the assembly manufacturer using the rotation speed detection output FG. Therefore, the two different specifications of the rotation speed detection output FG may be determined by any one or a combination of pulse width, duty, pulse amplitude, and pulse count.

[0026] Based on the speed command value sp input from the speed command value generation unit 441 and the position estimation signal input from the position estimation unit 46, the rotation control unit 47 outputs to the driver 43 a drive control signal for rotating the DC motor 3 in the rotation direction (CW or CCW) set in the rotation direction setting unit 45 at the rotation speed of the speed command value sp, and the driver 43 generates a drive signal for driving and controlling the inverter 42 and outputs the generated drive signal to the inverter 42.

[0027] Furthermore, when the test mode instruction signal test is input from the command discriminator 444, the rotation controller 47 outputs to the driver 43 a drive control signal for rotating the DC motor 3 in a preset test mode.

[0028] As described above, according to this embodiment, the motor drive device 40 controls the rotation speed of the DC motor 3 based on the speed command input VSP, which is an analog voltage, and the lower threshold voltage V spL ~Upper threshold voltage V spH a speed command value generator 441 that generates a speed command value sp that indicates the rotation speed of the DC motor 3 from a speed command input VSP within the range ofspH A command discrimination threshold voltage V th a rotation direction setting unit 45 that sets the rotation direction of the DC motor 3 to either clockwise (CW) or counterclockwise (CCW) and switches the set rotation direction when the command determining unit 444 determines that a rotation direction switching command is present; and a rotation control unit 47 that rotates the DC motor 3 in the rotation direction set in the rotation direction setting unit 45 at a rotation speed of the speed command value sp. With this configuration, the switching of the rotation direction of the DC motor 3 can be controlled using the speed command input VSP included in the five signal lines agreed upon between the motor manufacturer and the set manufacturer.

[0029] Furthermore, in this embodiment, the command discrimination unit 444 discriminates the test mode command based on another command input pattern different from the other command input pattern for discriminating the rotation direction switching command, and when the command discrimination unit 444 discriminates the test mode command, the rotation control unit 47 rotates the DC motor 3 in a preset test mode. With this configuration, a test mode command and a rotation direction change command can be received by the speed command input VSP.

[0030] Furthermore, according to this embodiment, a position estimation unit 46 is provided that estimates the position of the rotor relative to the stator of the DC motor 3 based on an input signal from the DC motor 3 and outputs a rotation speed detection output FG for monitoring the rotation speed of the DC motor 3, and the position estimation unit 46 outputs a rotation speed detection output FG of different specifications depending on the rotation direction set in the rotation direction setting unit 45. With this configuration, the rotation direction of the DC motor 3 can be determined by the rotation speed detection output FG included in the five signal lines agreed upon between the motor manufacturer and the assembled product manufacturer.

[0031] Although the present invention has been described above with reference to specific embodiments, it goes without saying that the above embodiments are merely examples and can be modified and implemented without departing from the spirit of the present invention. [Explanation of symbols]

[0032] 1. Electrical equipment 2. Motor device 3 DC motors 4, 40 Motor drive unit 11 Main control circuit 41 Power supply circuit 42 Inverter 43 Driver 44 Speed ​​command judgment section 45 Rotation direction setting section 46 Position estimation part 47 Rotation control section 441 Speed ​​command value generation unit 442 voltage divider circuit 443 Comparator 444 Command determination section

Claims

1. A motor drive device that controls the rotation speed of a motor based on a speed command input, a speed command value generating unit that generates a speed command value that indicates a rotation speed of the motor from the speed command input within a range from a lower threshold voltage to an upper threshold voltage; a command discrimination unit that discriminates a rotation direction switching command included in the speed command input based on another command input pattern of the speed command input that exceeds a command discrimination threshold voltage that is higher than the upper threshold voltage; a rotation direction setting unit that sets the rotation direction of the motor to either clockwise or counterclockwise, and switches the set rotation direction when the command discrimination unit discriminates that the rotation direction is switched; a rotation control unit that rotates the motor in the rotation direction set by the rotation direction setting unit at the rotation speed of the speed command value.

2. the command discrimination unit discriminates a test mode command based on the other command input pattern different from the other command input pattern for discriminating the rotation direction switching command, 2. The motor drive device according to claim 1, wherein the rotation control unit rotates the motor in a preset test mode when the command discrimination unit discriminates that the test mode command is issued.

3. a position estimating unit that estimates a position of a rotor relative to a stator of the motor based on an input signal from the motor and outputs a rotation speed detection output for monitoring the rotation speed of the motor; 3. The motor drive device according to claim 1, wherein the position estimation unit outputs the rotation speed detection output in a different format depending on the rotation direction set in the rotation direction setting unit.

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