JP2011001861A - Intake air quantity control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To overcome problems that a spring mechanism constituting a conventional turnout traveling mechanism (default mechanism) is constituted by a default lever and two winding springs, and the springs are arranged coaxially in series, a space for arranging the springs in the axial direction is required, a dimension of a throttle body is increased, and friction occurs due to sliding rotations of an outer circumference of a throttle shaft and an inner circumference of the default lever.SOLUTION: The default spring is constituted of a plate spring or the like, and has a fixed end integral with a throttle gear and a free end abutted to a stopper, and a return spring is arranged in parallel, and the axial length can be shortened, and the throttle body can be miniaturized. The contact part is reduced by securing a space between the spring and the throttle gear, and the contact part is reduced further by removing the default lever, reducing the friction.

Description

  The present invention relates to a throttle valve control device that controls the amount of intake air of an internal combustion engine in accordance with the operating state of the engine, and more particularly to a retreat travel mechanism when a throttle valve control device driven by a motor fails.

  In a so-called motor-driven throttle valve control device that drives and controls a throttle valve (throttle valve) by a DC motor or a stepping motor (hereinafter referred to as a motor), the vehicle can be safely operated even if the control circuit or the motor fails. In order to move to a place, it is necessary to equip a safety function that keeps the throttle valve opening at an opening that allows the vehicle to evacuate.

  In addition, when the engine key is off (in other words, when the electric actuator is de-energized), the throttle valve is stuck to the wall of the intake passage so that it cannot be opened by the motor torque at the start. In addition, a protective function for maintaining the throttle valve at a position opened from the fully closed position is necessary. Such a safety function and a protective function are called a retreat travel mechanism (or a default mechanism or an opener mechanism), and the opening at that time is called a retreat travel opening (or a default opening or an initial opening). Such a technique is composed of two springs as described in Japanese Patent Laid-Open No. 2000-110589 and a default lever that connects them, or as described in Japanese Patent Laid-Open No. 2002-256894. Some are composed of one spring.

JP 2000-110589 A JP 2002-256894 A JP 2004-169627 A JP 2008-190368 A

  In the conventional configuration, the mechanism is complicated because it is composed of two springs and a default lever that connects the two springs, and since the two springs are arranged in series, the dimension in the axial direction becomes long. In the case of a single spring without the default lever, it is difficult to reduce the size and simplification because the formation of the spring becomes complicated. Further, in the low opening range where the throttle valve rotates from the default opening to the fully closed state, there is a problem that friction occurs due to contact of the default lever or the spring.

  An object of the present invention is to configure a retreat travel mechanism by using a leaf spring whose configuration can be simplified.

  The above object of the present invention is to form a spring mechanism that constitutes a retreat travel mechanism by two leaf springs integrated with a throttle gear fixed to a throttle shaft, and a fixed end of the leaf spring is provided in the throttle body. A return spring that is fixed to the fixed immovable portion, the other free end is rotated through a leaf spring holding portion formed integrally with the throttle gear, and is held at the default opening degree by contacting the default stopper, The fixed end of the leaf spring is fixed to the leaf spring fixing portion provided on the throttle gear, and the other free end rotates together with the free spring end and contacts the default stopper to maintain the default opening. And a motor-driven throttle device for an internal combustion engine.

  According to the present invention configured as described above, the axial length as in the case of the coil spring is not required, and further, the springs are arranged in parallel, so that they can be arranged compactly and lightly around the rotation shaft of the throttle valve.

  In addition, the gear and the spring are integrated to facilitate assembly, and the spring structure is a leaf spring, so that the structure can be manufactured by press molding, and the formability and dimensional accuracy can be improved.

1 is a perspective view showing a motor-driven throttle device for an internal combustion engine according to Embodiment 1 of the present invention in a default opening state of a throttle valve. The front view in the default opening degree of FIG. The front view in the fully closed state of a throttle valve. The front view in the fully open state of a throttle valve. The perspective view which shows the motor drive type throttle device of the internal combustion engine which concerns on Example 2 of this invention in the default opening state of a throttle valve. The perspective view which shows the motor drive type throttle device of the internal combustion engine which concerns on Example 3 of this invention in the default opening state of a throttle valve. The perspective view which shows the motor drive type throttle device of the internal combustion engine which concerns on Example 4 of this invention in the default opening state of a throttle valve.

  Embodiments of the present invention will be described below on the basis of preferred embodiments of the present invention shown in the accompanying drawings.

  FIG. 1 is a schematic perspective view of a motor-driven throttle device for an internal combustion engine when a throttle valve is in a default opening state. FIG. 2 is a front view of the default opening state. FIG. 3 is a front view when the throttle valve is fully closed. FIG. 4 is a front view when the throttle valve is fully opened.

  As shown in FIG. 1, a throttle shaft 20 is rotatably held in the throttle body 10, and a throttle valve 30 is fixed thereto. The throttle valve 30 rotates in the throttle body internal air passage 11 to change the opening area. The driving torque of the electric motor 40 attached to the throttle body 10 is transmitted to the throttle shaft 20 via the speed reduction mechanism. The throttle gear 50 of the speed reduction mechanism is fixed to the end of the throttle shaft 20 protruding from the throttle body 10. With these configurations, the driving torque of the electric motor 40 is controlled, and the flow rate of air supplied to the engine is controlled by opening and closing the throttle valve 30.

  When the electric power supply to the electric motor 40 is cut off for some reason, a mechanism for holding the throttle valve 30 at the default opening is required so that retreating can be performed. This default mechanism is a mechanism for holding the throttle valve 30 at a default opening degree by a return torque of the spring, and mainly includes a return spring 60, a default spring 70, and a default stopper portion 12.

  In FIG. 1, the return spring 60 and the default spring 70 have a structure that avoids interference during the rotation of the spring by securing a gap in the axial direction with respect to the throttle gear 50. Each spring is the same whether it is arranged outside the throttle gear 50 or between the throttle gear 50 and the throttle body 10. Further, the same applies to the arrangement in which the return spring 60 and the default spring 70 are opposed to each other with the throttle gear 50 interposed therebetween.

  FIG. 2 shows a front view in the default opening state. The return spring 60 and the default spring 70 are arranged in parallel so as to avoid the throttle shaft 20. The return spring fixing end 61 is fixed to a spring fixing portion 13 formed on a part of the throttle body 10 so that the rotational direction and the radial direction are immovable. The other free end 62 is rotated and fixed from the free position A to the set position B contacting the default stopper portion 12 via the leaf spring restraining portion 51 integrated with the throttle gear 50. Next, the default spring fixed end 71 is fixed to a leaf spring fixing portion 52 integrated with the throttle gear 50 so that the rotational direction and the radial direction are immovable, and the other free end 72 is a free end 62 of the return spring. , Together with the return spring, it is rotated and fixed from the free position A to the set position B where it abuts on the default stopper portion 12.

  Next, the operation of the embodiment will be described.

  In FIG. 2, the closing direction torque TR of the throttle valve 30 acts on the return spring 60 by rotating from the free position A to the set position B contacting the default stopper portion. . The default spring 70 is rotated from the free position A to the set position B in contact with the default stopper portion, whereby the opening direction torque TD of the throttle valve 30 acts on the leaf spring fixing portion 52. Therefore, when the throttle shaft is used as a fulcrum, the closing direction torque TR is applied by the return spring 70 and the opening direction torque TD is applied by the default spring. If (closing direction torque TR)> (opening direction torque TD), the leaf spring restraining portion 51 is held in contact with the return spring free end 62, and the return spring free end 62 is the default stopper portion 12. Since it is held, the throttle valve 30 has a default opening.

  Next, the case where the throttle valve 30 operates in the range from the default opening to the fully closed will be described. FIG. 3 shows a front view with the throttle valve 30 fully closed. The drive torque from the electric motor 40 is transmitted to the throttle gear 50 through the speed reduction mechanism, and the throttle valve 30 is rotated in the closing direction. At this time, the rotation torque is transmitted to the default spring 70 through the leaf spring fixing portion 52, and therefore, deformation occurs, and an opening direction torque TD ′ is generated with respect to the throttle valve 20. By rotating against this rotational torque, the fully closed throttle gear end surface 53 and the fully closed stopper 14 of the screw assembled to the throttle body 10 come into contact with each other, and a mechanical fully closed position is set. At this time, since the return spring 60 is not deformed, the rotational torque is the same as that at the time of the default opening. Here, when the electric power supply to the electric motor 40 is cut off for some reason, the opening direction torque TD ′ generated by the deformation of the default spring 70 acts on the leaf spring fixing portion 52 to open the throttle valve 30. When the default opening is reached, the leaf spring restraining portion 51 abuts on the return spring free end 62, so that the default opening is maintained.

  Next, the case where the throttle valve 30 operates in the range from the default opening to the fully open will be described. FIG. 4 shows a front view with the throttle valve 30 fully opened. The drive torque from the electric motor 40 is transmitted to the throttle gear 50 through the speed reduction mechanism, and the throttle valve 30 is rotated in the opening direction. At this time, the rotational torque is transmitted to the return spring 60 via the leaf spring restraining portion 51, so that deformation occurs, and a closing direction torque TR ′ is generated with respect to the throttle valve 20. By rotating against this rotational torque, the throttle valve 30 opens and rotates to the requested throttle valve opening. At this time, since the default spring 70 is not deformed, the rotational torque is the same as that at the time of the default opening. Here, when the power supply to the electric motor 40 is cut off for some reason, the closing direction torque TR ′ generated by the deformation of the return spring 60 acts on the leaf spring restraining portion 51 to close the throttle valve 30. When the default opening is reached, the return spring free end 62 comes into contact with the default stopper 12 and is thus held at the default opening. In FIG. 4, the fully open stopper installed in the throttle body 10 is omitted.

  FIG. 5 is another embodiment of the present invention. In the first embodiment, the return spring 60 is a leaf spring, but this is an embodiment in which a coil spring is used. In the return spring 60 using a coil spring, as in the case of a leaf spring, the fixed end 61 is locked to the spring fixing portion 13 of the throttle body 10, and the free end is connected to the leaf spring holding portion 51 integrated with the throttle gear 50. Thus, the structure is in contact with the default stopper portion 12. On the other hand, the default spring is fixed to a leaf spring fixing portion 52 in which the default spring fixing end 71 is integrated with the throttle gear 50 in the same manner as in the first embodiment, and the other free end 72 contacts the default stopper portion 12. It has a structure.

  Since the other configuration is the same as that of (Example 1), the same reference numerals are assigned to the portions corresponding to (Example 1) in FIG. The operation is also the same as in (Example 1) and will not be described.

  FIG. 6 shows another embodiment of the present invention. In (Embodiment 1), the return spring and the default spring are separate parts, but this is an embodiment in which they are molded integrally. The return spring free end 62 and the default spring free end 72 are integrated, and the hook member 63 is formed by bending the spring member as shown in FIG. Here, as a method of integration, the same structure is used for welding. By integrating, the position of the default spring free end 72 is fixed, so the characteristics of the default spring 70 are further stabilized. In this embodiment, the fixed end 61 of the return spring is fixed to the spring fixing portion 13, and the default spring fixing end 71 is fixed to the leaf spring fixing portion 52. The spring hook portion 63 has a structure in which the return spring free end 61 abuts on the leaf spring restraining portion 51 and further abuts on the default stopper portion 12.

  Since the other configuration is the same as that of (Example 1), the same reference numerals are assigned to the parts corresponding to (Example 1) in FIG. The operation is also the same as in (Example 1) and will not be described.

  FIG. 7 shows another embodiment of the present invention. In (Embodiment 1), the return spring and the default spring are separate parts, but this is an embodiment in which they are molded integrally. The default spring 70 is formed by extracting and bending a part of the return spring free end 61. In this embodiment, the return spring fixing end 61 is fixed to the spring fixing portion 13, and the default spring fixing end 71 is fixed to the leaf spring fixing portion 52. Further, the return spring free end 61 abuts against the leaf spring restraining portion 51 and further abuts against the default stopper portion 12.

  Since the other configuration is the same as that of (Example 1), the same reference numerals are assigned to the portions corresponding to (Example 1) in FIG. The operation is also the same as in (Example 1) and will not be described.

  The summary of the embodiment described above is summarized as follows.

  In the motor-driven throttle device, a mechanism that enables retreat travel is necessary because the power supply to the electric motor is cut off for some reason. Conventionally, it is composed of a return spring and a default spring installed so as to sandwich a resin default lever. However, since these components are arranged in series on the same axis, a space is required. Further, when the default lever is in a low opening range from the default opening of the throttle valve to the fully closed position, there is a problem that friction is generated because the default lever rotates so as to slide on the outer periphery of the throttle shaft.

  According to the embodiment of the present invention, the function of the default lever can be provided by bringing the free end of the spring into contact with the default stopper, and it is caused by rubbing with the outer periphery of the throttle shaft when it occurs in the conventional default lever. Friction can be suppressed. In addition, by securing a gap in the axial direction so that the spring does not interfere with the throttle gear, it is possible to suppress the occurrence of friction caused by friction between the hook portion and the inner diameter portion of the coil and the spring guide portion, which has occurred in conventional coil springs. it can.

  By arranging the springs in parallel, the size can be reduced, and by adopting a leaf spring, the shape can be easily formed. Further, even when integrally molded, the structure can be formed only by bending or punching.

  In the above embodiment, since the spring mechanism capable of shortening the axial direction of the motor-driven throttle device can be provided, the gear case and the entire throttle body can be reduced in size. Further, even when a resin shaft is used, since the occurrence of friction is suppressed, problems such as wear are suppressed, so that a default mechanism can be established.

  The present invention can be used in a motor-driven throttle device for an internal combustion engine. The body of the throttle device may be metal or resin. The throttle shaft, throttle body, and gears may be metal or resin. There is no limitation on the type of motor, and the motor mounting position is not particularly limited.

DESCRIPTION OF SYMBOLS 10 Throttle body 11 Internal air passage 12 Default stopper part 13 Spring fixing part 14 Fully closed stopper 20 Throttle shaft 30 Throttle valve 40 Electric motor 50 Throttle gear 51 Leaf spring restraining part 52 Leaf spring fixing part 53 Fully closed throttle gear end surface 60 Return spring 61 Return spring fixed end 62 Return spring free end 63 Spring hook portion 70 Default spring 71 Default spring fixed end 72 Default spring free end A Free position B Set position TR Throttle valve closing direction torque TD by return spring Throttle valve opening direction by default spring Torque TD 'Torque valve opening direction torque TR' by deformation of default spring Throttle by deformation of return spring Valve closing direction torque

Claims (12)

A throttle device that is disposed in an air passage formed in a throttle body, includes a throttle valve that controls an intake air flow rate of an internal combustion engine, has a mechanism that transmits motor torque to the throttle shaft, and is driven to open and close by the motor. When the motor is de-energized, a spring force is generated to urge the throttle valve in the opening direction to a specific default opening larger than the fully closed position of the throttle valve, and from the fully opened throttle valve to the default opening. In the opening region of the one having a spring mechanism (default mechanism) that generates a spring force for urging the throttle valve in the closing direction,
It is composed of two leaf springs integrated with a throttle gear fixed to the throttle shaft, the stationary end of the leaf spring is fixed to a spring fixing portion which is a stationary portion provided in the throttle body, and the free end is A return spring that abuts on a default stopper that defines a default opening degree via a leaf spring restraining portion of the throttle gear, and a default that is fixed to a leaf spring fixing portion integrally formed with the throttle gear and abuts on the default stopper portion A motor-driven throttle device for an internal combustion engine, comprising a spring, wherein the return spring and the default spring are arranged in parallel. In claim 1,
A motor-driven throttle device for an internal combustion engine, wherein either one of the spring mechanisms is constituted by a leaf spring. In one of claims 1 and 2,
A motor-driven throttle device for an internal combustion engine, in which a leaf spring fixing portion or a leaf spring restraining portion is formed integrally with a part of the throttle gear. In claim 3,
A motor-driven throttle device for an internal combustion engine in which a part of the default spring is fixed to a leaf spring fixing portion of a throttle gear and rotates integrally. The motor-driven throttle device for an internal combustion engine according to claim 1 or 2, wherein the spring mechanism is held with a gap in a throttle shaft direction with respect to a throttle gear. In what is described in claim 1 or 2,
When the throttle valve rotates to the closed side from the default opening, the free end of the default spring is locked in contact with the default stopper, and is deformed until the throttle gear contacts the fully closed stopper. A motor-driven throttle device for an internal combustion engine. The motor-driven type of the internal combustion engine in which the free end of the default spring rotates away from the default stopper when the throttle valve rotates in an opening range larger than the default opening. Throttle device. 8. A motor-driven throttle device for an internal combustion engine that rotates to a rotational position of the throttle gear in a state where a fixed end of a leaf spring constituting the return spring is fixed to the spring fixing portion. . In what is described in claim 1 or 2,
The default spring is a motor-driven throttle device for an internal combustion engine provided in parallel with a return spring. In what is described in claim 1 or 2,
A motor-driven throttle device for an internal combustion engine having a mechanism for holding the default opening at a free end of a spring instead of a conventional resin default lever as the mechanism for holding the default opening. In what is described in claim 1 or 2,
A motor-driven throttle device for an internal combustion engine in which a combination of the springs is constituted by a plate spring and a coil spring. In what is described in claim 1 or 2,
A motor-driven throttle device for an internal combustion engine in which the spring mechanism is provided by one leaf spring or two leaf springs are joined and one end is locked to a default stopper.

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