Patent Document

BACKGROUND OF THE INVENTION 
     The present invention relates to a throttle control device and, particularly, to a control device having an accelerator operating system, a throttle operating system, a constant speed running control system and a traction control system. 
     Traction control for starting of an automobile has been performed by either (a) decreasing the depression of an acceleration pedal when a tire slip occurs, (b) performing slip control by means of an anti-skid brake control, or (c) decreasing a throttle opening by means of a constant speed running device, and the throttle control and the slip limiting control by a brake have been performed separately. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a throttle control device which is ganged with a slip limiting control to form a total traction control system. 
     The throttle control device according to this invention is constituted by an acceleration system, a constant speed running system, and a traction control system whose movable elements are connected to each other by wires so that the respective movable elements are ganged together. 
     In the present invention, the movable member of the acceleration system is moved correspondingly to the amount of depression of the acceleration pedal of the system through an acceleration wire, and the movable member of the throttle system is also moved through the throttle wire to open a throttle valve during a usual running control. Under a constant speed running control, an actuator moves the movable member of the constant running system through a constant speed wire and the movable member of the throttle system through the throttle wire, to control the opening of the throttle valve. On the other hand, under traction control, when a tire slip occurs due to an abrupt depression of the accelerator pedal, it is detected by a slip detector upon which a traction clutch is turned on to move the movable element thereof through the traction wire to thereby control the throttle valve opening through the movable element of the throttle such that the valve opening is reduced. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The single FIGURE shows a construction of an embodiment of a throttle control device according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     In the single Figure which shows a construction of an embodiment of the throttle control device according to the present invention, an acceleration pedal 1 is linked to an acceleration link 2 to which an end of an acceleration wire 3 is connected. An end of a pedal return spring 4 is connected to the acceleration link 2 to bias it in a return direction so that it is normally in an initial, idle position defined by a stopper 5. The acceleration wire 3 is disposed in an acceleration wire guide 6 movably therethrough and has one end connected to an acceleration movable element 7 which is biased in a return direction by a return spring 8 so that it is normally in an initial position defined by a stopper 9. A reference numeral 10 depicts an acceleration sensor provided on the movable element 7. A throttle link 11 is connected to a throttle valve (not shown) and has a movable portion to which one end of a throttle wire 12 is connected. The other end of the throttle wire 12 is connected to one end of a movable element 16. The throttle wire 12 is movable in a throttle wire guide 13. A reference numeral 30 depicts a stopper for restricting a maximum stroke position of the movable element 16. The throttle valve is biased in a closing direction by a throttle return spring 15 connected to the movable portion of the throttle link 11 so that it is in an initial position defined by a throttle link stopper 14. A reference numeral 28 depicts an intermediate disc which is provided coaxially with a shaft portion 16c of the movable element 16 in contact with a front end flange 16a thereof. An intermediate spring 29 is provided between the intermediate disc 28 and a rear flange 16b of the movable element 16. The intermediate spring 29 has a spring constant which is at least 1.5 times that of the throttle return spring 15. 
     A reference numeral 31 is a throttle sensor provided on the rear flange 16b of the movable element 16. A wire 17 for constant speed running has one end connected to a constant speed clutch 18 connected (cruise control) to an actuator 19 and the other end connected to a movable element 21 for constant speed to which a return spring 20 is connected to bias it in a resetting direction so that it is normally in an initial position defined by a stopper 22. The wire 17 is movable in a wire guide 23. 
     A traction wire 24 has one end connected to a traction clutch 25 connected to the actuator 19 and the other end connected to a movable element 33 for traction control. The wire 24 is connected to one end of a traction spring 26 and biased thereby to a traction side. The traction wire 24 is guided in a traction wire guide 27. 
     An operation of the throttle control device constructed as above will be described. 
     (I) Normal Running Control 
     When the acceleration pedal 1 is depressed during a 
     normal running condition, a torque is transmitted through the acceleration link 2 connected thereto to the acceleration wire 3, so that the latter is pulled in a direction shown by a solid arrow. When the depressing force applied to the pedal 1 is larger than the spring force of the return spring 8, the movable element 7 is shifted rightwardly together with the acceleration wire 3 so that a compression force is applied to the intermediate spring 29 through the intermediate disc 28. However, since the intermediate spring 29 is not compressed due to its high spring constant, and movable element 16 is shifted rightwardly, and the throttle wire 12 is pulled rightwardly to drive the throttle valve in an opening direction through the throttle link 11. As a result, an automobile speed is controlled correspondingly to the opening of the throttle. 
     (II) Constant Speed Running Control 
     Under a constant speed running condition, the clutch 18 is energized and the wire 17 is pulled in a solid arrow direction by the actuator 19 corresponding to a deviation of the vehicle speed from a set value. Therefore, the movable element 21 is shifted rightwardly and the throttle movable element 16 is also shifted rightwardly. As a result, the throttle wire 12 is pulled rightwardly to drive the throttle valve in the opening direction through the throttle link 11, and, when the speed deviation becomes zero, the opening of the throttle valve at this time is maintained to set the constant speed running condition. 
     Assuming that outputs of the acceleration sensor 10 and the throttle sensor 31 are depicted by S1 and S2, respectively, the following conditions are established, where S0 is an aimed throttle opening, S0&#39; is a controlled throttle opening and ΔS is a width of control. 
     
         ______________________________________At a start of constant speed running                 S2 = S0     (1)During constant speed running control                 S2&#39; = S0 ± Δ S                             (2)At an end of constant speed running                 S2&#34; = S0&#39; ≃ S0                             (3)______________________________________ 
    
     (III) Traction Control 
     Under a start condition of an automobile having a manual shift, a tire slip occurring due to an abrupt depression of the accelerator pedal 1 is detected by a slip detector provided on a brake system in response to which the traction clutch 25 is energized and the traction wire 24 is pulled in a direction shown by the solid arrow until the slip detection signal disappears regardless of the amount of depression of the acceleration pedal 1. Therefore, the movable element 33 is shifted leftwardly to control the throttle to reduce its opening defined by the depressed pedal 1 through the movable element 16 and, when the opening reaches an initial throttle opening, the traction control is terminated. 
     Assuming that outputs of the acceleration sensor 10 and the throttle sensor 31 are depicted by S1 and S2, respectively, the following conditions are established. 
     
         ______________________________________At a start of traction control               S1 = S2 = S0  (4)During a traction control               S2&#39; = S0 - Δ S                             (5)At an end of traction control               S2&#34;= S0&#39; = S0 (6)______________________________________ 
    
     where S0 is an initial opening, S0&#39; is a controlled opening and ΔS is a width of control. 
     When the acceleration pedal 1 is depressed continuously during the traction control, the intermediate spring 29 is compressed and the reactive force thereof is transmitted to the acceleration pedal 1. Therefore, the pedal feels heavy to an operator and he removes his foot to close the throttle valve. 
     (IV) Initial Condition 
     Under a control-free condition where none of the controls (I), (II), (III) and (IV) is performed or a power switch is turned off, the throttle valve is kept at closed condition or at minimum opening condition. Therefore, there is no such condition provided as an abrupt starting of the automobile. 
     As described hereinbefore, according to the present invention which is a throttle control device, either one of the normal running control, the constant speed running control and the traction control can be performed and under the initial condition the throttle valve is kept closed or substantially closed. Therefore, there is no uncontrolled starting of the automobile, resulting in an essentially safe automobile. Further, since all of the driving of the device is performed by wires, the device itself can be made compact, providing a high freedom of arrangement thereof. In addition, since the acceleration opening (or a shift amount of the acceleration wire ) and the throttle opening (or a shift amount of the throttle wire ) are detected by the acceleration sensor and the throttle sensor, respectively, and the throttle opening control is performed according thereto, the control itself becomes highly accurate.

Technology Category: 7