APPARATUS FOR CONTROLLING THROTTLE VALVE

Abstract: A throttle valve (2) of a car engine is operated by an electronic control. A wire cable (11) is extended between an accelerator pedal (19) and a motor (15) con­ trolled depending upon the driving conditions, a block (13) being disposed in contact with the wire cable, and the throttle valve (2) being opened and closed by the block (13). Ac­ cordingly, not only the optimum control of the throttle valve can be attained by driving the block taking the driv­ ing conditions into consideration but also in the case where the motor (15) is out of order, the throttle valve can be controlled by actuation of the block through the wire cable by the accelerator pedal, so that driving the car is still possible.

Description: BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to an apparatus for controlling a throttle valve in a car engine in accordance with the preamble of claim 1. Description of the Prior Art Recently, in order to improve a driving feeling and a roadablity of a car, an apparatus for controlling a throttle valve, in which an accelerator pedal is not connected with the throttle valve by means of the conventional simple mechanical means such as a wire cable but an electronic device is disposed between the accelerator pedal and the throttle valve to open and close the throttle valve in view of a driving condition of an engine and a traveling condition of a car in addition to a quantity of the accelerator stepped-in, has been developed. This apparatus for controlling a throttle valve requires a number of various kinds of driving information sensors including a sensor for detecting the quantity of an accelerator stepped-in and also an actuator for operating the throttle valve rind an electronic control device for treating signals from the respective sensors and controlling said actuator are required, so that it becomes remarkably complicated in comparison with the conventional ones using merely a wire cable. As a result, an important problem occurs in the security of reliability. That is to say, a so-called fail-safe mechanism for preventing a state, in which a car is run away due to a trouble in this electronic control device or the throttle valve is suddenly closed to suddenly brake the car during its high-speed travel, is indispensable. The fail-safe mechanism of the conventional electronic control device of this type, in which a return spring for returning the throttle valve to a closed position when a trouble has occurred is mounted on a throttle shaft, has been proposed. However, said conventional fail-safe mechanism has shown problems in that when the actuator is once fallen into a state impossible in action, the car can be prevented from running away but the travel of the car can not be maintained, whereby the car can not be moved to an appointed place for repairing; there is the possibility that the car is suddenly braked to be bumped from behind during its high-speed travel; and the like. The document JP-A-6 175 023 describes an apparatus for prevention of slipping of drive wheels upon acceleration. A throttle valve is opened by a throttle lever fixed to a throttle shaft which is pulled by means of an accelerator cable. The accelerator cable extends from an accelerator pedal via two pulleys to the throttle lever. Each pulley is mounted on a displace lever and both displace levers are moveable by an actuator for changing the distance between the pulleys. A similar apparatus is described in FR 2 535 263 where one moveable displace lever is used to adjust the distance between the two pulleys. The document WO 88/02 063 reflects a prior art according to Article 54 (3) EPC and describes a throttle valve controller with first and second drive motors, each driving a pulley. A first wire extends from a first pulley via a block to a second pulley. A second wire extends from the block to a throttle pulley fixedly mounted on a throttle shaft for rotating a throttle valve. Stepping-in of an accelerator pedal is controlled by a sensor and an arithmetic control unit controls the two motors. The GB 2 146 384 A describes a vehicle speed controller including a bowden cable which is connected at one end to an accelerator and at the other end to a throttle valve of the vehicle engine. An actuator drives a lever which is associated with a bowden cable via a pulley. The JP-A-59122 742 describes a throttle valve control device having two pulleys mounted on a motor shaft, which have projecting pieces which are engaged together upon rotation of the pulleys. The document JP-A-62-101 847 describes a throttle opening control device having a cylindrical body which is secured coaxially with an output shaft of a motor. A middle portion of a wire which connects a throttle valve with an accelerator pedal is winded plural times on a groove which is formed in a spiral form on the outer circumference of the cylindrical body. The patent specification AT 266 622 describes an apparatus for controlling a throttle valve of an engine wherein an accelerator lever and a controlling motor are mechanically connected by wires and levers to adjust the throttle valve. A driver can use a switch to control the controlling motor if the accelerator lever is not stepped in. It is the object of the present invention to provide an apparatus having an improved minute control for adjusting the position of the throttle valve. This object is solved by the apparatus according to claim 1. Further advantages and embodiments of the invention will more fully be apparent from the following detailed description with accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing a construction of an apparatus for controlling a throttle valve according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS The preferred embodiments of the present invention are below concretely described. Referring now to Fig. 1 which is a block diagram showing a construction of an apparatus for controlling a throttle valve according to the present invention, reference numeral 1 designates an air inlet pipe of an engine (not shown) and reference numeral 2 designates a throttle valve disposed in said air inlet pipe 1. The throttle valve 2 is fixedly mounted on a shaft 3 so that the valve 2 may be opened and closed by rotating said shaft 3. The shaft 3 is provided with a pulley 4 fixedly mounted thereon and a throttle wire 5 is extended around a groove of the pulley 4. In addition, a return spring 6, which is fixedly mounted on the pulley 4 at one end thereof, surrounds the shaft 3 and said return spring 6 is connected with a fixed end of the engine at the other end thereof so as to give a torque for returning the throttle valve 2 in the closing direction and give a tension to the throttle wire 5. The shaft 3 is provided with an openness sensor 7 for detecting an openness of the throttle valve 2 at a pointed end thereof. On the other hand, reference numeral 8 designates an accelerator lever connected with an accelerator pedal 19 and provided with a spring 9 for returning the accelerator lever 8 to the original position and an accelerator pedal sensor 10 for detecting a quantity of the accelerator pedal 19 stepped-in. In addition, one end of a wire cable 11 is fixedly mounted on the accelerator lever 8, the other end of said wire cable 11 being fixedly mounted on a motor pulley 14 through a pulley 12 and a block 13. Said motor pulley 14 is fixedly mounted on a shaft of a motor 15, the pulley 12 and the motor 15 being mounted on a base 16. The block 13 comprises a central shaft 131, said central shaft 131 being inserted into a groove 161 formed in the base 16 so as to be slidable in the up and down direction. In addition, the central shaft 131 is provided with a hook 132 engaged therewith, said throttle wire 5 being wound around this hook 132 with one end thereof fixedly mounted on the hook 132. In addition, reference numeral 17 designates a driving condition-detection sensor comprising various kinds of sensors for detecting for example a rotational speed of an engine, a traveling speed, skid of wheels and the like and puts out them to a controller 18. The controller 18 controls the motor 15 on the basis of the quantity of the accelerator stepped-in from the accelerator pedal sensor 10, the informations from the driving condition-detecting sensor 17 and the input from the throttle valve openness sensor 7. In operation, upon stepping-in the accelerator pedal 19, the wire cable 11 is pulled in the left direction by the motion of the accelerator lever 8. In addition, upon rotating the motor pulley 14 in the direction shown by an arrow A by means of the motor 15, the block 13 disposed so as to be brought into contact with the wire cable 11 is pulled up. Provided that a moving speed of the wire cable 11 by the accelerator lever 8 is Va, a moving speed of the wire cable 11 by the motor pulley 14 being Vm, and a moving speed of the throttle wire 5 mounted on the block 13 being Vs, a relation of Vs = (Va + Vm)/2 holds good. Since the throttle wire 5 is wound around the pulley 4 with one end thereof fixedly mounted on the pulley 4 and the pulley 4, the shaft 3 and the throttle valve 2 are integrally moved, finally the throttle valve 2 is operated by both the accelerator lever 8 (the accelerator pedal 19) and the motor 15. Since the moving speed of the wire cable 11 by the motor pulley 14 is proportional to the revolving speed of the motor 15, various kinds of driving operations, which have never been attained in the case where merely the accelerator pedal is stepped-in, can be attained by controlling the revolving speed of the motor 15. For example, in the case where a great acceleration is desired, a car can be smoothly started by increasing the revolving speed of the motor 15. On the contrary, in the case where there is the possibility of skidding, such as the case where a car is started on a frozen road and the like, the car can be smoothly started by reducing the revolving speed or reversing the revolution of the motor 15 according to circumstances. In addition, it is also possible to select the driving range showing the best engine efficiency in the travel of a car. Besides, these actions are carried out by treating the informations from the accelerator sensor 10, the throttle openness sensor 7 and the driving condition-detecting sensor 17 by means of the controller 18. In addition, with this apparatus for controlling a throttle valve, the throttle valve 2 is operated by both the accelerator lever 8 and the motor 15, as above described, so that even in the case where the motor system became uncontrollable at the worst, the throttle operation can be attained to an extent that the travel of a car can be maintained merely by means of the accelerator pedal 19 by suitably setting a diameter of the motor pulley 14, whereby the fail-safe can be secured. Although the motor pulley 14 is directly connected with the motor 15 in this preferred embodiment, the motor pulley 14 may be connected with the motor 15 through a worm-gear. As above described, according to the present invention, the throttle valve is adapted to be opened and closed by the block disposed in contact with the wire cable extended between the accelerator pedal and the motor, so that not only the travel of a car, which is optimum for the driving conditions, can be attained but also the travel of a car is possible even in the case where the motor system is out of order.

Claims: Apparatus for controlling a throttle valve (2) which is fixedly mounted on a shaft (3) and which is opened and closed by rotating the shaft (3), the apparatus comprising an accelerator pedal (19), a wire cable (11) one end thereof is connected to the accelerator pedal (19), a motor (15) which is controlled by driving information of a car, a motor pulley (14) being connected to the motor (15), a block (13) which is disposed in contact with the shaft (3) for rotating the shaft and which is disposed in contact with the wire cable (11) and driven by the wire cable (11), characterized in that, the other end of the wire cable (11) is fixedly mounted on the motor pulley (14) via a further pulley (12) and the block (13), the motor pulley is driveable by the motor (15), said further pulley (12) and said motor pulley (14) are mounted on a base (16) a pulley (4) is fixedly mounted on the shaft (3) and biased by a return spring (6), a throttle wire (5) is provided one end thereof is fixedly mounted on the block (13) and the other end thereof is fixedly mounted on the pulley (4), the block (13) is moveably mounted on the base (16) to be pulled up by the wire cable (11) if the accelerator pedal (19) is stepped in and/or the motor (15) rotates the motor pulley (14). An apparatus for controlling a throttle valve as set forth in Claim 1, in which said motor pulley (14) is fixedly mounted on a shaft of the motor (15). An apparatus for controlling a throttle valve as set forth in Claim 1, in which said motor (15) is connected with said motor pulley (16) through a worm-gear. An apparatus for controlling a throttle valve as set forth in Claim 1, in which said driving informations of a car comprise at least one of a revolving speed of an engine, a traveling speed of a car, skid of wheels, a quantity of accelerator stepped-in and an openness of a throttle valve (2).

Inventors: SHIRAKAWA, HIROYUKI C/O HIMEJI SEISAKUSHO
Applicants: MITSUBISHI DENKI KABUSHIKI KAISHA
Application year: 1988
Main classification: F02D11
IPC codes: F02D11, F02D9