JP2009127449A - Variable valve gear, actuator control device and turning angle sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a variable valve gear capable of controlling a turning angle of a control shaft with a simple constitution. <P>SOLUTION: This variable valve gear includes the control shaft 12 for variably setting a lift quantity of a valve, a motor 14 for rotating the control shaft 12, and a speed reduction mechanism 18 for transmitting rotation of the motor 14 to the control shaft 12 by reducing a speed, and includes a male screw member 24 having an outer peripheral surface forming a male screw and rotating together with an output shaft 16 of the motor 14, a female screw member 26 having a hole forming a female screw threadedly engaging with the male screw member 24 and linearly moving in its rotary shaft direction by rotating the male screw member 24, an output detecting means for detecting output corresponding to a position of the female screw member 26, and a control means for controlling the turning angle of the control shaft 12 based on the output detected by the output detecting means. A variable resistor 28 is desirably used as the output detecting means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a variable valve operating device, an actuator control device, or a rotation angle sensor, and more particularly to an actuator sensor structure suitable for use in a variable valve operating device capable of changing a valve lift amount.

  Conventionally, for example, as disclosed in Japanese Patent Application Laid-Open No. 2005-248849, by rotating a control shaft of a variable valve mechanism by a motor, the lift amount of the valve can be set variably according to the rotation angle. Variable valve gears that can be used are known. This apparatus includes a rotation angle sensor that changes the output according to the rotation position of the control shaft, and is configured to appropriately drive the motor so that the detected rotation position matches the target position.

JP 2005-248849 A

  By the way, during the normal operation of the engine, the control shaft of the variable valve gear rotates only about 60 degrees. For this reason, it is difficult to accurately detect the rotation angle in the configuration in which the rotation angle of the control shaft is directly detected using the rotation angle sensor disposed on the control shaft, as in the conventional variable valve device. Become. For this reason, in order to improve detection accuracy, an expensive rotation angle sensor having high resolution has to be used.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a variable valve apparatus that can control the rotation angle of a control shaft with a simple configuration. It is another object of the present invention to provide an actuator control device that can control the rotation angle of the actuator with a simple configuration, or a rotation angle sensor used therefor.

In order to achieve the above object, a first invention is a variable valve gear,
A variable valve operating apparatus comprising: a control shaft for variably setting a lift amount of a valve; a motor for rotating the control shaft; and a speed reducing mechanism for decelerating the rotation of the motor and transmitting it to the control shaft. In
A male screw member having an outer peripheral surface on which a male screw is formed and rotating together with the output shaft of the motor;
A female screw member that has a hole in which a female screw to be screwed with the male screw member is formed, and that moves linearly in the rotation axis direction by rotating the male screw member;
Output detecting means for detecting an output corresponding to the position of the female screw member;
Control means for controlling the rotation angle of the control shaft based on the output detected by the output detection means;
It is characterized by providing.

According to a second invention, in the first invention,
The output detection means includes a variable resistor that changes a resistance value corresponding to a moving position of the female screw member.

According to a third invention, in the second invention,
The control means feedback-controls the rotation angle of the motor so that the output detected by the output detection means coincides with the output corresponding to the target rotation angle of the control shaft.

In order to achieve the above object, a fourth invention is an actuator control apparatus,
A control device for an actuator driven by a motor,
A male screw member having an outer peripheral surface on which a male screw is formed and rotating together with the output shaft of the motor;
A female screw member that has a hole in which a female screw to be screwed with the male screw member is formed, and that moves linearly in the rotation axis direction by rotating the male screw member;
Output detecting means for detecting an output corresponding to the position of the female screw member;
Control means for controlling the rotation angle of the motor based on the output detected by the output detection means;
It is characterized by providing.

In order to achieve the above object, a fifth invention is a rotation angle sensor,
A male screw member having an outer peripheral surface on which a male screw is formed and rotating together with the output shaft of the motor;
A female screw member that has a hole in which a female screw to be screwed with the male screw member is formed, and that moves linearly in the rotation axis direction by rotating the male screw member;
Output detecting means for detecting an output corresponding to the position of the female screw member;
It is characterized by providing.

  According to the first invention, when the motor is rotated to rotate the control shaft of the variable valve mechanism, the male screw member rotates with the rotation of the motor. On the other hand, the female screw member screwed with the male screw member moves in the axial direction of the male screw member according to the rotation angle of the male screw member. For this reason, according to the present invention, the rotation angle of the control shaft can be detected by detecting the output corresponding to the position of the female screw member, so the rotation angle of the control shaft can be accurately controlled with a simple configuration. can do.

  According to the second invention, the movable terminal of the variable resistor is attached to the female screw member, and when the female screw member moves in the axial direction of the male screw member, the movable terminal moves together with this and the resistance value is variable. It is comprised so that. For this reason, according to this invention, the output according to the position of a female screw member is detectable via the said variable resistor.

  According to the third invention, the rotation angle of the motor is feedback-controlled so that the output according to the position of the female screw member becomes an output value corresponding to the target rotation angle of the control shaft. For this reason, according to the present invention, the rotation angle of the control shaft can be accurately controlled.

  According to the fourth invention, when the motor is rotated to drive the actuator, the male screw member rotates with the rotation of the motor. On the other hand, the female screw member screwed with the male screw member moves in the axial direction of the male screw member according to the rotation angle of the male screw member. For this reason, according to the present invention, since the rotation angle of the motor can be detected by detecting the output corresponding to the position of the female screw member, the rotation angle of the actuator can be accurately controlled with a simple configuration. Can do.

  According to the fifth invention, when the motor is rotated, the male screw member rotates with the rotation of the motor. On the other hand, the female screw member screwed with the male screw member moves in the axial direction of the male screw member according to the rotation angle of the male screw member. For this reason, according to the present invention, the rotation angle of the motor can be accurately detected by detecting the output corresponding to the position of the female screw member.

  Embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited to the following embodiments.

Embodiment [Configuration of Embodiment]
FIG. 1 shows an overall configuration diagram for explaining a system configuration of the present embodiment. As shown in this figure, the system of the present embodiment includes a variable valve mechanism 10. For example, the variable valve mechanism 10 changes a rocking amount or rocking timing of a rocker arm (not shown) according to a rotation angle of a control shaft 12 to be described later, thereby changing a valve amount such as a lift amount, a working angle, or a valve timing. It is comprised so that the valve opening characteristic of can be changed continuously. Specifically, the variable valve mechanism 10 in the present embodiment is configured using a known technique as described in, for example, Japanese Patent Application Laid-Open No. 2005-248849.

  Further, as shown in FIG. 1, the variable valve mechanism 10 of the present embodiment includes a control shaft 12. The variable valve mechanism 10 is provided with a motor 14 for driving the control shaft 12 to rotate at an arbitrary angle. The motor 14 includes an output shaft 16 that can rotate forward and backward depending on the energized state. As shown in FIG. 1, the output shaft 16 transmits a large rotational torque to the control shaft 12 while rotating around the axis AA.

  Further, a speed reduction mechanism 18 is interposed between the motor 14 and the control shaft 12. The speed reduction mechanism 18 transmits a large rotational torque to the control shaft 12 while reducing the rotational output of the motor 14. Specifically, as shown in this figure, the speed reduction mechanism 18 includes a worm shaft 20 attached to the output shaft 16 of the motor 14 and a worm wheel 22 fixed to the outer peripheral side of the control shaft 12. Yes.

  The worm shaft 20 is arranged coaxially with the output shaft 16 of the motor 14 and rotates together with the output shaft 16. The worm shaft 20 is held in mesh with the worm wheel 22.

  On the other hand, the worm wheel 22 is formed as a flat gear part having a substantially sector shape, and protrudes outward in the radial direction from the control shaft 12. The worm wheel 22 is rotationally driven by the motor 14 via the worm shaft 20 and rotates together with the control shaft 12.

  Further, the system of the present embodiment includes a male screw member 24 formed integrally with the worm shaft 20 described above. Male thread processing is applied to the outer peripheral surface of the male thread member 24. The male screw member 24 is arranged coaxially with the output shaft 16 of the motor 14 together with the worm shaft 20, and is configured to rotate with the output shaft 16.

  A female screw member 26 is screwed into the male screw portion of the male screw member 24. More specifically, the female screw member 26 includes a hole in which an inner peripheral surface is subjected to female screw processing, and the female screw portion of the hole is screwed into the male screw portion of the male screw member 24. Yes. The female screw member 26 is connected to a movable terminal 29 of a variable resistor 28 described later. For this reason, when the male screw member 24 rotates about the axis AA, the female screw member 26 itself moves in the direction of the axis AA without rotating.

  In the system according to the present embodiment, the variable resistor 28 is fixed in the vicinity of the female screw member 26. The variable resistor 28 includes a movable terminal 29 that can move in the direction of the axis AA. The movable terminal 29 of the variable resistor 28 is fixed to the female screw member 26. For this reason, when the position of the female screw member 26 moves, the resistance value of the variable resistor 28 changes.

  The system of the present embodiment also includes a driver 34 for supplying driving power to the motor 14, a battery 36 as driving power, and an amplifier 32 for sending an operation command to the driver 34. Further, the system of the present embodiment includes an ECU (Electronic Control Unit) 30 as the control device. The ECU 30 specifies the optimum lift amount based on the operating state of the engine and the like, and calculates a target rotation angle of the motor 14 for realizing the lift amount.

[Operation in the embodiment]
Next, the operation of the system of this embodiment will be described with reference to FIG.

(Change operation of valve lift)
In order to decrease the lift amount of the valve, the motor 14 is operated to rotate the output shaft 16 in the direction of decreasing the lift amount. The rotation of the output shaft 16 is transmitted to the worm wheel 22 via the worm shaft 20. Thereby, the control shaft 12 of the variable valve mechanism 10 is rotationally driven together with the worm wheel 22 in the lift decreasing direction, and the lift amount of the valve decreases in accordance with the rotation angle of the control shaft 12.

  On the other hand, when increasing the lift amount of the valve, the output shaft 16 of the motor 14 is rotated in the increasing direction of the lift amount. As a result, the control shaft 12 of the variable valve mechanism 10 is driven to rotate in the lift increasing direction via the speed reduction mechanism 18, and the lift amount of the valve increases in accordance with the rotation angle of the control shaft 12.

(Control shaft rotation angle control operation)
When the lift amount of the valve is specified based on the operating state of the engine, rotation control of the control shaft is executed in order to realize the lift amount. More specifically, the motor 14 is appropriately driven so that the actual rotation angle of the control shaft 12 coincides with a target rotation angle for realizing a desired lift amount.

  Here, since the rotation angle of the control shaft 12 used in the normal lift amount variable operation is in the range of about 60 degrees, the configuration that directly detects the rotation angle of the control shaft 12 accurately detects the rotation angle. It becomes difficult.

  Therefore, in the present embodiment, the resistance value of the variable resistor 28 is changed according to the rotation angle of the motor 14. More specifically, as described above, the male screw member 24 is disposed on the output shaft 16 of the motor 14. For this reason, when the male screw member 24 is rotated by the rotation of the output shaft 16 of the motor 14, the female screw member 26 that is screwed to the male screw member 24 moves in the direction of the axis AA. A movable terminal 29 of a variable resistor 28 is attached to the female screw member 26. For this reason, the resistance value of the variable resistor 28 can be changed according to the rotation angle of the motor 14.

  The output of the variable resistor 28 is sent to the amplifier 32 as position feedback information of the control shaft 12. Specifically, for example, a voltage value of 2V to 8V is output according to the resistance value of the variable resistor 28. In addition, the ECU 30 calculates an output (for example, a voltage value of 2V to 8V) corresponding to the rotation angle target value of the control shaft 12 specified based on the operating state, and sends it to the amplifier 32. The amplifier 32 compares these output values and outputs an operation command corresponding to the difference to the driver 34. The driver 34 supplies drive power corresponding to the supplied operation command from the battery 36 to the motor 14.

  As described above, according to the system of the present embodiment, the output voltage value from the variable resistor 28 can be directly used as the control physical quantity, so that the rotation angle of the control shaft 12 can be performed without performing processing such as signal conversion. Can be controlled to a desired rotation angle. Further, since the operation of the variable resistor 28 is performed by utilizing the rotation of the motor 14 before being decelerated by the speed reduction mechanism 18, a sufficient amount of movement of the movable terminal 29 is ensured and the detection accuracy is effectively improved. Can be made.

  Note that the rotation angle variable range of the control shaft 12 in the variable valve mechanism 10 varies depending on the engine on which the variable valve device is mounted. Therefore, when the rotation angle variable range of the control shaft 12 is different, the pitch of the male screw member 24 and the female screw member 26 is changed. Specifically, when the rotation angle variable range of the control shaft 12 is narrow, by increasing the pitch of the male screw member 24 and the female screw member 26, the variable range of the variable resistor 28 is widened and the detection resolution is maintained. can do.

  In the above-described embodiment, the worm shaft 20 and the worm wheel 22 are used as the speed reduction mechanism 18, but the speed reduction mechanism used in the present invention is not limited to this. That is, as long as the rotation of the output shaft 16 of the motor 14 is decelerated and transmitted to the control shaft 12, a configuration in which a plurality of gears are further interposed may be used, or another reduction mechanism may be used.

  In the above-described embodiment, the male screw member 24 is formed integrally with the worm shaft 20 and is attached to the output shaft 16 of the motor 14. However, the mounting location of the male screw member 24 is the output of the motor 14. It is not limited to the same axis and axis. That is, as long as high-speed rotation of the motor 14 is transmitted, the motor 14 may be arranged on a shaft different from the output shaft 16 and transmit power through a gear.

  Further, in the above-described embodiment, the movable terminal 29 of the variable resistor 28 is attached to the female screw member 26 and a voltage corresponding to the position of the female screw member 26 is output. The configuration for detecting the position of is not limited to this. That is, the output according to the position of the female screw member 26 may be detected using another known method.

  In the above-described embodiment, the rotation angle of the control shaft 12 in the variable valve mechanism 10 is controlled. However, the control target of the present invention is not limited to the variable valve mechanism 10. That is, it may be used for a control device for another actuator that is driven by a motor and requires control of the rotation angle. Moreover, the structure including the male screw member 24, the female screw member 26, and the variable resistor 28 may be used for other purposes as a sensor for detecting the rotation angle.

It is a whole block diagram for demonstrating the system configuration | structure of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Variable valve mechanism 12 Control shaft 14 Motor 16 Output shaft 18 Deceleration mechanism 20 Worm shaft 22 Worm wheel 24 Male screw member 26 Female screw member 28 Variable resistor 29 Movable terminal 30 ECU (Electronic Control Unit)
32 Amplifier 34 Driver 36 Battery

Claims (5)

A variable valve operating apparatus comprising: a control shaft for variably setting a lift amount of a valve; a motor for rotating the control shaft; and a speed reducing mechanism for decelerating the rotation of the motor and transmitting it to the control shaft. In
A male screw member having an outer peripheral surface on which a male screw is formed and rotating together with the output shaft of the motor;
A female screw member that has a hole in which a female screw to be screwed with the male screw member is formed, and that moves linearly in the rotation axis direction by rotating the male screw member;
Output detecting means for detecting an output corresponding to the position of the female screw member;
Control means for controlling the rotation angle of the control shaft based on the output detected by the output detection means;
A variable valve operating apparatus comprising:   2. The variable valve operating apparatus according to claim 1, wherein the output detecting means includes a variable resistor that changes a resistance value corresponding to a moving position of the female screw member.   The control means feedback-controls the rotation angle of the motor so that the output detected by the output detection means coincides with the output corresponding to the target rotation angle of the control shaft. The variable valve operating apparatus according to 2. A control device for an actuator driven by a motor,
A male screw member having an outer peripheral surface on which a male screw is formed and rotating together with the output shaft of the motor;
A female screw member that has a hole in which a female screw to be screwed with the male screw member is formed, and that moves linearly in the rotation axis direction by rotating the male screw member;
Output detecting means for detecting an output corresponding to the position of the female screw member;
Control means for controlling the rotation angle of the motor based on the output detected by the output detection means;
An actuator control device comprising: A male screw member having an outer peripheral surface on which a male screw is formed and rotating together with the output shaft of the motor;
A female screw member that has a hole in which a female screw to be screwed with the male screw member is formed, and that moves linearly in the rotation axis direction by rotating the male screw member;
Output detecting means for detecting an output corresponding to the position of the female screw member;
A rotation angle sensor comprising:

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