JPH0212097Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a safety device for a constant speed driving system for an automobile that causes the automobile to run at a predetermined speed.

Conventionally, this type of constant speed driving system for automobiles uses a comparator to compare a set speed signal set to a desired speed with an actual vehicle speed signal corresponding to the current vehicle speed, and outputs the result from the comparator. There is a known system in which a servo motor is driven by a control signal corresponding to the difference between a set speed signal and an actual vehicle speed signal to control the valve opening of a throttle valve so that the vehicle runs at a set speed ( For example, in 1977
−120027).

By the way, in the above-mentioned constant speed driving system for an automobile, the opening degree of the throttle valve changes depending on the engine load of the automobile, and the heavier the engine load, the larger the opening degree of the throttle valve becomes.

For this reason, when the engine load increases, for example when the car is climbing a slope, the throttle valve opening will increase, but if the engine load is extremely large, the throttle valve opening will not be fully open. Even when the servo motor is eventually locked, a current continues to flow through the servo motor in the direction of increasing the valve opening, and there is a risk that the servo motor may be burnt out.

The present invention was developed in view of the above-mentioned circumstances regarding constant speed driving systems for automobiles, and is a constant speed driving system for automobiles that prevents the motor from seizing due to the motor lock of the motor linked to the throttle when the throttle is fully opened. The purpose is to provide safety equipment.

Therefore, the present invention is designed to transmit the driving force of the motor to the throttle in a constant speed driving system for automobiles, which compares the set vehicle speed and the actual vehicle speed, and uses the motor to drive the engine throttle opening according to the difference. a clutch mechanism disposed within the throttle link system that disconnects the transmission of the driving force of the motor to the throttle and causes the motor to idle; a rotating member that interlocks with the opening and closing of the throttle; The present invention is characterized by comprising a limit switch that is opened and closed when the moving member reaches a fully open throttle position, and a clutch control circuit that operates the clutch mechanism in response to a signal from the limit switch.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a block diagram of a constant speed driving system for automobiles to which the present invention is applied.

In FIG. 1, 11 is a vehicle speed detector (not shown) for detecting the actual vehicle speed of a car, 12 is a multiplier, 13 is a speed register, 14 is a control switch, 15 is a cancel switch, 16 is a command decoder, and 17 is a control logic. , 18 is a pulse converter, 19 is an output driver, and 20 is a servo motor.

The vehicle speed detector 11 includes, for example, a reed switch that is turned on and off by a magnet co-rotating with the axle of the vehicle (not shown), and outputs an actual vehicle speed signal S having a frequency proportional to the actual vehicle speed of the vehicle to the multiplier 12.

The multiplier 12 converts the actual vehicle speed signal S into a digital signal S' that can be input to the control logic 17 and temporarily stores it in the speed register 13.

On the other hand, the command decoder 16 receives an acceleration (Acc) signal a input from the control switch 14,
The deceleration (COAST) signal b, the return (RESUME) signal c, and the brake signal d input from the cancel switch 15 are decoded, and a set vehicle speed signal e is given to the control logic 17.

The control logic 17 compares the set vehicle speed signal e inputted from the command decoder 16 with the digital signal S' representing the actual vehicle speed inputted from the speed register 13, and sends a difference signal f representing the difference to the pulse converter 18. Output.

The output of the pulse converter 18 is input to an output driver 19, which causes the servo motor 20 to rotate in accordance with the difference signal f between the set vehicle speed signal e and the digital signal S' representing the actual vehicle speed. Direction (forward, reverse) and rotation are controlled.

The above multiplier 12, speed register 13, command decoder 16, control logic 17, pulse converter 18, and output driver 19 constitute one control unit, which is a circuit mainly composed of a microcomputer and its input/output interface circuit. It can be configured by

In the present invention, in a constant speed driving system for an automobile having the above configuration, as shown in FIG. 2, an accelerator link 31 is connected to a throttle valve (not shown) to open and close the throttle valve. A cam 33 is attached to the shaft 32 of the throttle valve, and a limit switch 34 is attached near the cam 33 so that its push rod 35 is pressed when the throttle valve is fully opened.

The above limit switch 34 is the accelerator link 3
The support plate 3 is attached to the support plate 36 that supports the shaft 32 of the
It is fixed at 6.

On the other hand, the planetary gear mechanism 41, which constitutes a part of the mechanism for transmitting the rotational output of the servo motor 20 to the shaft 32 of the accelerator link 31, has its input shaft 42 and output shaft 43 connected to the signal of the limit switch 34. An electromagnetic clutch 44 is provided for coupling and disconnecting.

The electromagnetic clutch 44 is a limit switch 34.
Output driver 19 to which the output signal of
When the push rod 35 of the limit switch 34 is pressed by the cam 33, the electromagnetic clutch 44 disconnects the input shaft 42 and output shaft 43 of the planetary gear mechanism 41.

The planetary gear mechanism 41 includes a sun gear 45 fixed to one end of an input shaft 42, planet gears 46, 46 that mesh with the sun gear 45 and revolve around it while rotating, and these planet gears 46, 46 mesh with each other. The output shaft 43 and a disc 48 rotatably supporting the planetary gears 46, 46 are coupled and disconnected by the electromagnetic clutch 44.

The input shaft 42 of the planetary gear mechanism 41 includes an output pinion 51 of the servo motor 20, a pinion 52 that meshes with the output pinion 51, and a pinion 52 that meshes with the output pinion 51.
a worm gear 53 attached to one end and a worm wheel 54 meshing with the worm gear 53;
The rotational output of the servo motor 20 that has been decelerated is transmitted.

The rotation of the output shaft 43 of the planetary gear mechanism 41 is controlled by a rotating plate 55 attached to one end of the output shaft 43, a rotating plate 56 attached to one end of the shaft 32 of the accelerator link 31, and a rotating plate 56 attached to one end of the shaft 32 of the accelerator link 31. The throttle link 58 formed by the wire 57 connecting the plates 55 and 56 connects the accelerator link 3.
1 of the shaft 32.

If the constant speed driving system for a car has the above configuration, when the throttle valve is not fully opened when the car is running at a constant speed, the cam 3 attached to the shaft 32 of the accelerator link 31
3 is the push rod 35 of the limit switch 34
is not pressed.

Therefore, the output driver 19 energizes the electromagnetic clutch 44 to connect the input shaft 42 and output shaft 43 of the planetary gear mechanism 41, and the valve opening of the throttle valve is controlled by the servo motor according to the engine load. 20, the car runs at a constant speed.

Now, in the above condition, the engine load increases,
When the servo motor 20 moves the throttle valve to the fully open position, the cam 33 attached to the shaft 32 of the accelerator link 31 switches the limit switch 34.
Press the push rod 35.

The output driver 19, as described above,
When the push rod 35 of the limit switch 34 is pressed by the cam 33, the electromagnetic clutch 44 is deenergized by the signal from the limit switch 34, and the input shaft 42 and output shaft 4 of the planetary gear mechanism 41 are
Separate from 3.

As mentioned above, the input shaft 42 of the planetary gear mechanism 41
When the servo motor 20 and the output shaft 43 are separated, the servo motor 20 can freely rotate, and even if the engine load increases, the servo motor 20 will not be locked due to the throttle valve being fully opened.

Although the basic embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, instead of the control unit 21 as shown in FIG. The present invention can also be applied to a constant speed driving system for automobiles using a feedback circuit according to the present invention.

As is clear from the above detailed description, the present invention provides a clutch mechanism in the throttle link system that transmits the driving force of the motor that drives the engine throttle to the throttle, and the clutch mechanism is installed in the throttle link system to transmit the driving force of the motor that drives the engine throttle to the throttle. Since the transmission of the motor's driving force to the throttle is disconnected during subsequent overcontrol, when the engine load increases during constant speed driving and the throttle valve opens fully, the motor is disconnected from the throttle and the motor becomes free. This makes it possible to eliminate motor burnout and wasteful power consumption due to motor lock, and also to prevent excessive force from being applied to the motor's power transmission system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a constant speed driving system for an automobile to which the present invention is applied, and FIG. 2 is an explanatory diagram of a power transmission mechanism from a servo motor to an accelerator link. 11... Vehicle speed detector, 14... Control switch, 15... Cancel switch, 16...
Command decoder, 17... Control logic, 20... Servo motor, 31... Accelerator link, 33... Cam, 34... Limit switch, 44... Electromagnetic clutch, 58... Throttle link.

Claims (1)

[Scope of utility model registration request] In a constant speed driving system for an automobile that compares a set vehicle speed and an actual vehicle speed and drives the throttle opening of the engine by a motor according to the difference, a throttle link system that transmits the driving force of the motor to the throttle; The throttle link system includes a clutch mechanism that disconnects the transmission of the driving force of the motor to the throttle and causes the motor to idle; a rotating member that is linked to the opening and closing of the throttle; 1. A safety device for a constant speed driving system for an automobile, comprising: a limit switch that is opened and closed by the limit switch; and a clutch control circuit that operates the clutch mechanism in response to a signal from the limit switch.