JP2010110084A - Dc motor apparatus and window switching device equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a DC motor apparatus which can inexpensively control rotation of a DC motor with a simple structure and to provide a window switching device equipped with the DC motor apparatus. <P>SOLUTION: The DC motor apparatus includes the DC motor 1, an H bridge circuit 2 for switching a direction of rotation of the DC motor 1, a power supply part 3 for supplying current to the DC motor 1 through the H bridge circuit 2, and a control part (microprocessor 4) controlling the H bridge circuit 2. The control part detects a potential difference which periodically fluctuates between electrode terminals 15 of the DC motor 1 and controls the H bridge circuit 2 so that the DC motor 1 is stopped or it reversely rotates when it detects that a period of fluctuation of the potential difference between the electrode terminals 15 of the DC motor 1 changes at the time of positive rotation of the DC motor 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a DC motor device for controlling an automatic opening / closing operation of a power window, an electric sunroof or the like, and a window opening / closing device provided with the DC motor device.

  A DC motor can rotate a motor simply by applying a voltage between electrodes and supplying a direct current, and the number of rotations of the motor can be controlled by controlling the applied voltage. Widely used. For example, as an automatic opening / closing mechanism for a power window of an automobile, a DC motor device including a DC motor is installed on the door of the automobile.

  A DC motor device used for an automatic opening / closing mechanism of a power window of an automobile selects and controls either forward rotation or reverse rotation of a DC motor based on an operation signal input by an operation of a switch attached to a door. It has a function of stopping the rotation of the DC motor when the window glass is fully opened or fully closed. Furthermore, it has a function of stopping the rotation of the DC motor even when the neck or hand is pinched during the automatic opening / closing operation of the power window.

As a power window control device having such a function, a device that includes a pulse generator that repeatedly generates a pulse corresponding to the operation of a motor and measures the pulse period has been proposed (see Patent Document 1). .).
Japanese Patent No. 3917803

  However, the power window control device described in Patent Document 1 uses a gear crest attached to the rotation shaft of the motor, or uses a Hall IC and a sensor magnet to invert the magnetic field based on the rotation of the motor. Since it is provided with the pulse generator to detect, it will lead to a cost increase.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a DC motor device that can control the rotation of a DC motor at a low cost with a simple structure and a window opening / closing device including the DC motor device.

  The present invention provides a DC motor, an H bridge circuit for switching forward and reverse rotation of the DC motor, a power supply unit that supplies current to the DC motor via the H bridge circuit, and control of the H bridge circuit. And a control unit that detects a periodically varying potential difference between the electrode terminals of the DC motor and between the electrode terminals of the DC motor when the DC motor is rotating forward. The DC motor device is characterized by controlling the H-bridge circuit so as to stop or reversely rotate the DC motor when it detects that the period of fluctuation of the potential difference is changed.

  In addition, the present invention is a window opening and closing device comprising the DC motor device and a window member that opens and closes by forward and reverse rotation of the DC motor.

  According to the DC motor device of the present invention, the periodically varying potential difference between the electrode terminals of the DC motor is detected, and the variation period of the potential difference between the electrode terminals of the DC motor when the DC motor is rotating forward. When the change is detected, the H-bridge circuit is controlled so as to stop or reversely rotate the DC motor, so that the rotation of the DC motor can be controlled despite the inexpensive and simple structure.

  In addition, according to the window opening and closing device of the present invention, since the above-described DC motor device and the window member that opens and closes by forward and reverse rotation of the DC motor are provided, it is inexpensive to prevent the neck and hand from being caught in the window. A window opening and closing device can be realized.

  An embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic explanatory diagram of a DC motor device of the present invention, and FIG. 2 is an explanatory diagram of the internal structure of the DC motor shown in FIG.

  As shown in FIG. 1, a DC motor device according to the present invention supplies a current to a DC motor 1, an H bridge circuit 2 for switching forward and reverse rotation of the DC motor 1, and the DC motor 1 via the H bridge circuit 2. And a microprocessor 4 (control unit) that controls the H-bridge circuit 2. The control unit detects a periodically varying potential difference between the electrode terminals 15 of the DC motor 1. When it is detected that the cycle of the potential difference variation between the electrode terminals 15 of the DC motor 1 changes while the DC motor 1 is rotating forward, the H bridge circuit 2 is set so that the DC motor 1 is stopped or reversely rotated. It comes to control.

  The DC motor 1 is provided with a stator 11 having a substantially circular cross section, a plurality of permanent magnets 12 provided on the inner wall of the stator 11 at predetermined intervals in the circumferential direction, and the stator 11 so as to be rotatable forward and backward. The rotor 13, the brush 14 in contact with the commutator 131 constituting the rotor 13, and the electrode terminal 15 are included.

  The stator 11 is a housing that houses the permanent magnet 12 and the rotor 13 therein.

  In FIG. 2, two permanent magnets 12 are provided on the inner wall of the stator 11 with an interval of 180 degrees, one being an N pole permanent magnet and the other being an S pole permanent magnet.

  The rotor 13 is provided with three mushroom-like protrusions 133 that protrude in the radial direction from the rotary shaft 132 at intervals of 120 degrees. Each of the protrusions 133 is wound with a coil 134, and the rotary shaft A commutator 131 partitioned by three insulating parts 135 provided at intervals of 120 degrees is disposed at 132. And the coil 134 wound around each protrusion part 133 and the commutator 131 are electrically connected, and each protrusion part 133 forms an electromagnet. In FIG. 2, two of the three protrusions 133 form an N pole, and the rest form an S pole.

  The brush 14 is held by the electrode terminal 15 of the DC motor 1 and is disposed so as to contact the commutator 131.

  With such a configuration, when a direct current is supplied to the electrode terminal 15, an attractive force or a repulsive force is generated between the permanent magnet 12 and the projecting portion 133 serving as an electromagnet, so that the rotor 13 rotates. .

  Here, when a current is supplied to the coil 134 of the DC motor 1, a magnetic field is generated by the current, and the permanent magnet 12 and the projecting portion 133 are repeatedly moved closer to and away from each other. An electromotive force is generated. Therefore, as shown in FIG. 3, the potential difference periodically varies between the electrode terminals 15 of the DC motor 1.

  An H-bridge circuit 2 for switching between forward and reverse rotation of the DC motor 1 is electrically connected to the electrode terminal 15 of the DC motor 1.

  The H bridge circuit 2 is a switching element composed of four field effect transistors 2a, 2b, 2c, and 2d, and these field effect transistors 2a, 2b, 2c, and 2d are selected by a selection control signal supplied from the microprocessor 4. ON / OFF is selectively controlled. Specifically, when the gate voltages of the field effect transistors 2a and 2c are set to a logic high level and the gate voltages of the field effect transistors 2b and 2d are set to a logic low level, the DC motor 1 in FIG. Is supplied from left to right. When the gate voltages of the field effect transistors 2b and 2d are set to a logic high level and the gate voltages of the field effect transistors 2a and 2c are set to a logic low level, the DC motor 1 is turned on from the right in FIG. A current passing to the left is supplied. Further, when the gate voltages of the field effect transistors 2a and 2b are made the same and the gate voltages of the field effect transistors 2c and 2d are made the same, no current is supplied to the DC motor 1.

  The power supply unit 3 supplies current to the DC motor 1 via the H-bridge circuit 2, and from the power supply unit 3 by on / off selection control of the field effect transistors 2 a, 2 b, 2 c, and 2 d as described above. A current is supplied to the DC motor 1 along a desired path. Reference numeral 7 denotes a ground, which forms both positive and negative poles in relation to the power supply unit 3.

  The microprocessor 4 (control unit) detects a periodically changing potential difference between the electrode terminals 15 of the DC motor 1 and detects the potential difference between the electrode terminals 15 of the DC motor 1 when the DC motor 1 is rotating forward. When it is detected that the period of fluctuation has changed, a selection control signal for selectively controlling on / off of the field effect transistors 2a, 2b, 2c and 2d of the H-bridge circuit 2 is sent. That is, when the DC motor 1 is rotating forward as shown in FIG. 3 and detecting that the period of the potential difference variation between the electrode terminals 15 of the DC motor 1 changes as shown in FIG. The H bridge circuit 2 is controlled so that 1 is stopped or reversely rotated. The microprocessor 4 also has functions other than the above control.

  Here, when the cycle of the potential difference variation between the electrode terminals 15 of the DC motor 1 changes when the DC motor 1 is rotating forward, an excessive load is applied to the DC motor 1 and the rotational speed of the rotor 13 decreases. This is the case. For example, a DC motor device is used as a part of a window opening / closing device such as a power window, and a neck or a hand is caught during automatic opening / closing of the window.

  In the DC motor device according to the present invention, since the potential difference and the numerical value of the current are not detected, but the change in the period (frequency) of the potential difference is detected, it is necessary to provide an external resistor or the like. However, the rotation of the DC motor 1 can be controlled in spite of an inexpensive and simple structure.

  In addition, it is preferable that a differential amplifier circuit 5 is provided in a path through which information related to the period of variation in potential difference between the electrode terminal 15 of the DC motor 1 and the microprocessor 4 is sent as shown in FIG. .

  Further, a low pass filter 6 is provided between the electrode terminal 15 of the DC motor 1 and the microprocessor 4 as shown in FIG. 1 in order to remove chattering noise due to brush friction, coil switching, and the like. Is preferred. For example, the amplified signal is blocked by a low-pass filter from a motor rotation speed (3,000 rpm MAX) to a frequency signal of 165 Hz or higher. As a result, a frequency component that is longer than the period originally generated by the rotation of the DC motor 1 is removed.

  In addition, when a decoupling element is mounted between the electrode terminal 15 of the DC motor 1 and the microprocessor 4 and between the H bridge circuit 2 and the microprocessor 4, electromagnetic noise entering the microprocessor 4 is reduced. And the operation of the microprocessor becomes stable.

  Further, the present invention is a window opening / closing device (not shown) including the above-described DC motor device and a window member that opens and closes by forward / reverse rotation of the DC motor, and the power of the DC motor is transmitted by a gear and an equalizer arm. The windows are designed to open and close. For example, it is suitable for the window opening and closing device of the mechanism that keeps the window moving upward or downward automatically even when the switch is released, and it is inexpensive to prevent the neck and hands from being caught in the window A window opening and closing device can be realized.

It is a schematic explanatory drawing of the DC motor apparatus of this invention. It is explanatory drawing of the internal structure of the DC motor shown in FIG. It is explanatory drawing which shows the state from which an electrical potential difference fluctuates periodically between the electrode terminals of a DC motor. It is explanatory drawing which shows the state from which the period of the fluctuation | variation of the electric potential difference between the electrode terminals of DC motor changed.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... DC motor 11 ... Stator 12 ... Permanent magnet 13 ... Rotor 131 ... Commutator 132 ... Rotating shaft 133 ... Protruding part 134 ... Coil 135 ... Insulation Part 14 ... Brush 15 ... Input / output electrode 2 ... H bridge circuit 2a, 2b, 2c, 2d ... Field effect transistor 3 ... Power supply part 4 ... Microprocessor 5 ... Difference Dynamic amplification circuit 6 ... low-pass filter 7 ... ground

Claims (2)

A DC motor, an H bridge circuit for switching between forward and reverse rotation of the DC motor, a power supply unit that supplies current to the DC motor via the H bridge circuit, and a control unit that controls the H bridge circuit And the control unit detects a periodically varying potential difference between the electrode terminals of the DC motor, and the potential difference between the electrode terminals of the DC motor when the DC motor is rotating forward. A DC motor device that controls the H-bridge circuit to stop or reversely rotate the DC motor when it is detected that the cycle of fluctuation has changed. A window opening and closing device comprising: the DC motor device according to claim 1; and a window member that opens and closes by forward and reverse rotation of the DC motor.

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