JP2009299639A - Throttle valve control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid a valve full open state and an engine over revolution condition when abnormality occurs on wiring connected to a motor for driving a throttle valve in a throttle valve control device controlling only drive in a valve open direction. <P>SOLUTION: In an electronic control unit 10A as the throttle valve control device controlling throttle opening by driving the motor 3 only in the open direction resisting elastic repulsion force of a spring member always energizing the throttle valve 4 in a close direction, a high side switch 13 and a voltage detection circuit 12 detecting ground side voltage of the motor 3 in the middle of a battery plus side wiring of the motor 3, and a wiring abnormality determination means determining based on the detection data whether abnormality occurs in wiring connected to the motor 3 are provided, and electric power supply to the motor 3 is shut off by the high side switch 13 when the wiring abnormality determination means determines that abnormality occurs in the wiring. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a throttle valve control device, and more particularly to a throttle valve control device that opens and closes a throttle valve installed in an intake system of an engine by electronic control of an actuator.

  In recent years, in order to perform engine control with high accuracy, instead of mechanically opening and closing the throttle valve by the driver's accelerator operation, an electronically controlled throttle (electronically controlled governor) that is electronically opened and closed by an electronic control unit has been developed. It is popular. For example, an engine system equipped with an electronically controlled throttle as described in Japanese Patent Laid-Open No. 2-57436 and shown in FIG. 3 has been widely put into practical use.

  In such an engine system having an electronically controlled throttle, a detection signal is input from an engine speed detection device 5 attached to the engine 1 to an electronic control unit 10C as a throttle valve control device, and the detected engine speed data. Based on the above, the electronic control unit 10C drives and controls the motor 3 in a direction to keep the desired rotational speed constant, thereby adjusting the opening of the throttle valve 4.

  The control of the throttle valve 4 by the electronic control unit 10C generally performs drive control in the opening direction and the closing direction of the valve while switching the forward / reverse rotation of the motor 3 with an H bridge circuit. On the other hand, a spring 40 that normally biases the throttle valve 4 in the closing direction is provided as in the engine system shown in the layout diagram of FIG. An electronically controlled throttle that controls the drive only in the opening direction is also known.

However, in the case of such a one-way control type electronically controlled throttle, the electronic control unit 10B as the throttle valve control device has only a circuit for controlling the motor 3 in the opening direction as shown in the circuit layout diagram of FIG. For example, when the wiring (harness wire) for driving the motor 3 is short-circuited to the ground at point A, the motor 3 always moves in the opening direction, so that the throttle valve 4 is fully opened and the engine is over-rotated. There is a problem of falling into a state.
Japanese Patent Laid-Open No. 2-57436

  The present invention is intended to solve the above-described problems, and in the case where an abnormality occurs in the wiring connected to the motor for driving the throttle valve in the throttle valve control device that controls only the driving in the valve opening direction. Another object of the present invention is to avoid a situation in which the throttle valve is fully opened to prevent the engine from over-rotating.

  Therefore, the present invention adjusts the power input state from the battery to the motor so that the throttle valve disposed in the intake passage of the engine is always urged in the closing direction in the opening direction against the elastic repulsion force of the spring member. In the throttle valve control device for controlling the throttle opening only by driving the motor, the switch means arranged in the middle of the plus (+) side wiring of the battery in the motor and the ground (G) side voltage of the motor It is provided with voltage detection means for detecting and wiring abnormality determination means for determining whether or not an abnormality has occurred in the wiring connected to the motor from the detection data by the voltage detection means, and the abnormality has occurred in the wiring When the determination is made, the power supply to the motor is cut off by the switch means.

  For example, when a wiring trouble occurs, such as when the motor wiring is short-circuited to the ground side, the throttle valve is fully open in the conventional throttle valve control device, the wiring abnormality determination means in the present invention By determining that the abnormality has occurred in the wiring, the power supply to the motor is cut off using the switch means, so that the throttle valve can be reliably prevented from being fully opened.

  Further, in this throttle valve control device, the switch means is a high-side switch and can be controlled by the CPU, and is built in the casing together with a circuit constituting the voltage detection means, and is integrated into one electronic control unit as a whole. By doing so, it becomes easy to make the entire control device compact, and the power supply to the motor is surely cut off.

  By providing the wiring abnormality judging means and the switch means to cut off the power supply to the motor in a predetermined situation, when an abnormality occurs in the wiring connected to the motor for driving the throttle valve, the valve is fully opened. It is assumed that the engine will not fall into an overspeed condition.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 2 is a layout diagram of an engine system in which the throttle valve control device of the present embodiment is arranged. The hardware configuration other than the electronic control unit 10A as the throttle valve control device in the present embodiment has been described above. This is common with an engine system provided with an electronic control unit 10B as a conventional throttle valve control device.

  In this embodiment, the case where the throttle valve control device of the present invention is mounted on an engine system in which fuel is supplied to the engine 1 by the injector 8 and ignited by the spark plug 7 will be described. The same applies to the case of.

  The electronic control unit 10A, which is a throttle valve control device to which the engine speed detection signal detected by the engine speed detection device 5 is input, maintains the optimum speed constant by the engine 1 from the detected engine speed data. In this direction, the throttle valve 4 disposed in the intake passage 2 is controlled to be opened and closed by the motor 3. Note that the throttle body, the throttle valve 4, the motor 3, and the spring 40 that biases the throttle valve 4 in the closing direction, which constitute a part of the intake passage 2, are combined into one part.

  The electronic control unit 10A controls the drive of the motor 3 only in the opening direction of the throttle valve 4. The valve closing direction opposite to this is mechanically operated by a spring 40. By adjusting the balance between the elastic repulsive force and the driving force of the motor 3, the throttle valve 4 can be opened and closed.

  In the conventional example, as shown in the circuit layout diagram of FIG. 4, the ground (G) side of the motor 3 is activated by the drive transistor 14 in the electronic control unit 10B, and a current is supplied to the motor 3, and this is operated as a valve. Although the control is performed so that the motor is driven in the opening direction, in this system, since the wiring connected to the motor 3 is short-circuited to the ground, the current always flows through the motor 3, so that the throttle valve 4 is always operated. The engine was fully open and had a problem with engine overspeed.

  On the other hand, in the electronic control unit 10A as the throttle valve control device of the present embodiment shown in the circuit arrangement diagram of FIG. 3, the plus (+) side wiring in the battery of the motor 3 is not directly connected to the motor 3. Instead, it is once taken into the electronic control unit 10A (inside the casing), and the plus (+) side voltage of the battery is supplied to the motor 3 via the high side switch 13 as a switch means that can be controlled by the CPU 11A. Characterized by dots.

  Further, a voltage detection circuit 12 as a voltage detection means for detecting the voltage on the ground side of the motor 3 is built in the electronic control unit 10A so that the voltage at the point A of the wiring (harness wire) connected to the motor 3 is detected. It has become. Based on the voltage data detected by the voltage detection circuit 12, the electronic control unit 10A has detected an abnormality in the wiring of the motor 3, such as when the wiring abnormality determination means has short-circuited to the ground side at the point A of the wiring. It comes to judge.

  The wiring abnormality determination means can be realized by the voltage detection circuit 12 as well as being constituted by a dedicated circuit or the like, but operates the high side switch 13 according to the determination result as described below. In view of necessity, what is functionally realized by the CPU 11A and a program is preferable from the viewpoint of simplification of the apparatus.

  When it is determined that an abnormality has occurred in the wiring in the electronic control unit 10A, the power supply path on the battery + side of the motor 3 is interrupted by the high side switch 13 and the power supply to the motor 3 is stopped. It is like that. As a result, the throttle valve 4 moves in the valve closing direction by the urging force of the spring 40, so that it is possible to effectively avoid a situation in which the engine 1 falls into an over-rotation state, and fail safe can be executed reliably.

  Note that the electronic control unit 10A described above is configured such that each means for performing such a function is accommodated in one unit and is compact as a whole, so that a small arrangement space is sufficient, and The above-described operation and effect can be easily realized simply by disposing this in the engine system.

  As described above, with respect to the throttle valve control device that controls only the drive in the valve opening direction, according to the present invention, when an abnormality occurs in the wiring connected to the motor for driving the throttle valve, the situation where the valve is fully opened is described. It was avoided and the engine was not over-rotated.

1 is a circuit layout diagram according to an embodiment of the present invention. FIG. 2 is a layout diagram of an engine system common to the present embodiment and a conventional example. The layout of the engine system of a prior art example. The circuit arrangement figure of a prior art example.

Explanation of symbols

  1 engine, 2 intake passage, 3 motor, 4 throttle valve, 5 engine rotation speed detection device, 10A electronic control unit, 11A CPU, 12 voltage detection circuit, 13 high side switch, 14 drive transistor, 40 spring

Claims (2)

  By adjusting the power input state from the battery to the motor, the motor is driven only in the opening direction against the elastic repulsion force of the spring member that constantly urges the throttle valve disposed in the intake passage of the engine in the closing direction. In the throttle valve control apparatus for controlling the throttle opening by this, the switch means arranged in the middle of the plus (+) side wiring of the battery in the motor, and the voltage detection means for detecting the ground (G) side voltage of the motor Wiring abnormality determining means for determining whether an abnormality has occurred in the wiring connected to the motor from the detection data by the voltage detection means, and when determining that an abnormality has occurred in the wiring, A throttle valve control device characterized in that power supply to the motor is cut off by a switch means. The switch means comprises a high-side switch and can be controlled by a CPU, and is housed in a casing together with a circuit constituting the voltage detection means, and is integrated into one electronic control unit as a whole. Item 2. The throttle valve control device according to Item 1.

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