JPH0331613Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Field of Application) The present invention relates to a constant speed running device for an automobile, and particularly to one that prevents the operation of a diaphragm in view of the delay in its operation in cold weather.

(Prior art) A constant speed driving device for an automobile is a device that maintains a set vehicle speed set in the controller by controlling a throttle valve with a controller via an actuator to drive at a constant speed. When a set signal is output to the controller when the desired running speed is reached during driving, the set vehicle speed is memorized, this set vehicle speed is compared with the detected vehicle speed, and the throttle valve is activated via the actuator based on this comparison value output. It is controlled so that it runs at a constant speed.

In conventional constant speed driving systems, a release signal is output to the controller to cancel constant speed driving control at any time other than when the main switch is turned off or the clutch pedal is depressed. For example, Japanese Patent Application Laid-Open No. 141880/1983 describes a system in which a release signal is output to cancel constant speed driving control even when the stop lamp is lit or when the fuse of the stop lamp circuit is blown, in order to prevent dangerous conditions such as runaway. ing.

By the way, a rubber diaphragm is usually built into the actuator of a constant speed traveling device, and the pressure is adjusted by introducing negative pressure of intake air or atmospheric air into a negative pressure introduction working chamber facing the diaphragm through a solenoid valve controlled by a controller. As a result, the opening and closing of the throttle valve is controlled via the diaphragm, but when it is cold, the diaphragm hardens and its elastic modulus increases significantly, causing a delay in its operation and causing the constant speed traveling device to malfunction. There is a problem.

(Purpose of the invention) This invention was made in view of the above problems.
An object of the present invention is to provide a constant speed driving device for an automobile that can prevent constant speed driving control in cold weather.

(Structure of the invention) The constant speed driving device for an automobile according to the invention includes an actuator that has a diaphragm connected to a throttle valve of an automobile engine and controls the throttle valve with the diaphragm, and a vehicle speed for constant speed driving. A constant speed traveling device for an automobile, comprising a vehicle speed setting means for setting a vehicle speed, and a control means for controlling the actuator in response to an output signal from the vehicle speed setting means, the constant speed traveling device detecting a temperature near a diaphragm of the actuator. A temperature detecting means is provided, and a constant speed running preventing means is provided for receiving an output signal from the temperature detecting means and outputting a signal for preventing operation of the actuator to the control means.

In the above configuration, the temperature near the diaphragm of the actuator is detected by the temperature detection means, and when the temperature is below a set value (for example, -20°C), the control means receives an output signal from the temperature detection means and is transferred from the constant speed running prevention means to the control means. A signal is output to prevent the actuator from operating, and control by the constant speed traveling device is released.

(Effects of the invention) Since the invention is constructed and operates as described above, there is a danger that the constant speed traveling device may malfunction due to a delay in the operation of the diaphragm caused by hardening of the diaphragm of the actuator in cold weather, causing the car to run out of control. It is possible to eliminate this problem and improve its safety.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

The constant speed running device of this automobile is shown in Figures 1 and 2.
As shown in the figure, a control device 5 is connected via a main switch 4 to an output line 3 led out from a power source 1 via an ignition switch 2, and includes a set switch 6 and a coast switch as vehicle speed setting means. 7. The solenoid 11 of the actuator 10 receives each output signal of the resume switch 8 and the output signal of the reed switch 9 of the vehicle speed sensor.
A control device 5 that outputs to each of a, 12a, and 13a.
and the above-mentioned set switch 6, coast switch 7, and resume switch 8 as vehicle speed setting means.
, a temperature switch 14 as a blocking means, a brake switch 15 and a clutch switch 16 as release means, and an actuator 10 having a diaphragm 18 connected to a throttle valve 17 of a carburetor.

The control device 5 is composed of a logic circuit whose main part is, for example, a TTL integrated circuit.

The set switch 6 is connected between the set signal input terminal of the control device 5 and the ground.
It is set to turn ON when the desired vehicle speed is reached within the Km/H vehicle speed range, and to drive at a constant speed at the moment the switch is turned OFF.

The above-mentioned coast switch 7 is connected between the coast signal input terminal of the control device 5 and the ground, and is set to decelerate by continuing to turn it on while driving at a constant speed, and to drive at a constant speed at the moment the vehicle is turned off. It is.

The above-mentioned resume switch 8 is connected between the resume signal input terminal of the control device 5 and the ground, and when the constant speed traveling control is canceled by other than the operation of the main switch 4, by turning it on, the constant speed before the cancellation is resumed. This is to return the vehicle to running speed.

The structure of the actuator 10 will be explained with reference to FIG. 2. A rubber diaphragm 18 is disposed inside a casing 19.
An annular base end 20 of the casing 19 is fixed near the center of the inner circumferential surface of the casing 19 by a fixing ring 21 that also serves as a sealing member, and the diaphragm 18
The inside is divided into a first chamber 22 that is airtight to the outside and a second chamber 23 that communicates with the outside through an opening 24, and is interposed between the diaphragm 18 and the casing 19 in the first chamber 22. The diaphragm 18 is elastically biased toward the second chamber 23 by a return spring 25 made of a compression coil spring, and the diaphragm 18 is pushed inside the second chamber 23.
The base end of a rod 27 arranged concentrically with the axis of the casing 19 is connected to the disk 26 fixed to the central wall of the casing 19, and the rod 27 is slidably inserted through the end wall 19b of the casing 19. and casing 19
The other end of the rod 27 is connected to the throttle valve 17 of the carburetor via a release wire 28 or the like.

End wall 19 of the casing 19 on the first chamber 22 side
A is formed inwardly in a concave shape, and three sets of solenoid valves 11, 12 (not shown) are installed in this part from the outside.
is installed. That is, the upstream passage 29a of the negative pressure introduction solenoid valve 11 is communicated with the first chamber 22, the downstream passage 29b is communicated with the intake manifold through the piping 30, and the valve body 31 is connected to the downstream passage 29b.
The solenoid 11a is biased by a spring to the valve seat 32 of the solenoid 11a.
When energized, the valve opens and intake negative pressure is introduced into the first chamber 22.

The upstream passage 33a of the first vent solenoid valve 12 is open to the atmosphere through the communication hole 34, the downstream passage 33b is communicated with the first chamber 22, and the valve body 35 approaches and separates from the valve seat 36 of the downstream passage 33b. The valve element 35 is biased to open by a tension spring, and is configured to close when the solenoid 12a is energized.

The second vent solenoid valve is provided below both of the solenoid valves 11 and 12, and its structure is similar to the first vent solenoid valve 12, and only its solenoid 13a is shown in FIG.

The solenoids 11a, 12a, 13a are connected to respective output terminals 11b, 12b, 13b of the control device 5, and their other ends are connected to the end of the output line 3 facing the power supply of the main switch 4.

Next, a clutch switch 16 that is turned on when the clutch is pressed as a means for canceling the constant speed running control, a brake switch 15 that is turned on when the brake is pressed, and a temperature near the actuator 10 that is used as a blocking means and a temperature detection means. Temperature switches 14 that turn on when the temperature drops below a set temperature (for example, -20° C.) are connected in parallel with each other, and are connected between the output line 3 and the release signal input terminal of the control device 5.

For example, as shown in FIG. 3, the temperature switch 14 has a resistor 37 and a thermistor 38 connected in series between the output line 3 and the ground, and an intermediate connection point between them.
It is connected to the base of the NPN transistor 39 and its collector is connected to the output line 3 via a current reducing resistor 40, while its emitter is connected to the control device 5.
It is configured by connecting to the release signal input terminal of.

As shown in FIG. 4, a thermistor 38a and a resistor 37a are connected in series between the output line 3 and the ground, and their intermediate connection point is connected to the base of a transistor 39a, and the collector is connected to the output line through a resistor 40a. 3, and its collector may be connected to the release signal input terminal.

However, the thermistor 38 is attached to the end wall 19a of the casing 19 facing into the first chamber 22 of the actuator 10 so as to respond to the temperature near the diaphragm 18 of the actuator 10, but the characteristics of the thermistor 38 are as follows: In relation to this, it is necessary to set the base current so that when the temperature falls below the set temperature, the base current flows and the transistor is activated.

However, in place of the thermistor 38 above, approximately -20
A temperature sensing element such as a crite resistor (CTR) having a sudden change in resistance around .degree. C. may be used, or the temperature switch 14 may be a bimetallic switch that turns on at around -20.degree.

Note that the output circuits 41, 42, 4 from the control device 5
3 are connected to an inhibitor switch, a stop lamp switch and a vehicle speed switch, respectively.

Next, the operation of the constant speed traveling device will be explained.

In the control device 5, the detection signal from the reed switch 9 of the vehicle speed sensor and the set vehicle speed signal set by the set switch 6 are compared, and when the vehicle speed is less than the set value, each solenoid 11a, 12a
As a result, the negative pressure introduction solenoid valve 11 is opened and the first vent solenoid valve 12 is closed, and intake negative pressure is introduced into the first chamber 22 of the actuator 10 and the slot The tuttle valve 17 is operated to increase the opening degree, and the vehicle speed increases.

When the vehicle speed becomes higher than the set value, the solenoids 11a and 12a are not energized, the negative pressure introduction solenoid valve 11 is closed, the first vent solenoid valve 12 is opened, and the negative pressure in the first chamber 22 of the actuator 10 is closed. The pressure is relieved, and the throttle valve 17 is operated to decrease the opening degree via the diaphragm 18, thereby reducing the vehicle speed.

When maintaining the vehicle speed, solenoid 12a is energized without energizing solenoid 11a, both solenoid valves 11 and 12 are closed, and throttle valve 17 is held in that position.

As described above, the control device 5 controls the opening and closing of each solenoid valve to control the vehicle to travel at a constant speed.

In addition, clutch switch 1 is used as a release means.
6. When either the brake switch 15 or the temperature switch 14 as a blocking means is turned on, no electricity is applied to any of the solenoids 11a, 12a, 13a, the negative pressure introduction solenoid valve 11 is closed, and the first vent solenoid is closed. Valve 12 and second
The vent solenoid valve is opened, constant speed driving control is canceled, and the throttle valve 17 is operated by the accelerator pedal.

However, the solenoid valve for the second vent is normally closed and is opened only when a release signal from the clutch switch 16 brake switch 15 or temperature switch 14 is output to the control device 5; This is provided in advance so that the constant speed traveling control can be reliably canceled even when the solenoid valve 12 fails.

Regarding the temperature switch 14 shown in FIG. 3 above, the resistance value of the thermistor 38 increases as the temperature decreases, and when the temperature is below the set temperature (for example -20°C), the resistance value of the thermistor 38 exceeds the set value and the base current increases. As a result, the transistor 39 is activated and a release signal is output to the control device 5.

Regarding the temperature switch 14 shown in FIG. 4, when the temperature is below the set temperature, the base voltage decreases, the transistor 39a becomes non-conductive, the collector voltage increases, and a release signal is output to the control device 5.

According to the vehicle constant speed traveling device of the above embodiment,
By simply installing a temperature switch with an extremely simple configuration, when the temperature drops below the set temperature in cold weather and the operation of the diaphragm becomes unstable, it prevents the constant speed running device from operating, eliminating the risk of runaway and other safety issues. You can improve your sexuality.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a schematic circuit diagram of a constant speed traveling device, Fig. 2 is a vertical cross-sectional view of an actuator connected to a throttle valve, and Figs. 3 and 4. are each a circuit diagram of a temperature switch. 5...Control device, 6...Set switch, 7...
...Coast switch, 8...Regium switch, 10...Actuator, 14...Temperature switch, 17...Throttle valve, 18...Diaphragm.

Claims (1)

[Claims for Utility Model Registration] An actuator having a diaphragm connected to a throttle valve of an automobile engine and controlling the throttle valve with the diaphragm, a vehicle speed setting means for setting the vehicle speed for constant speed driving, A constant speed driving device for a motor vehicle, comprising: a control means for controlling the actuator in response to an output signal from the vehicle speed setting means; 1. A constant speed traveling device for a motor vehicle, comprising constant speed traveling inhibiting means for receiving an output signal from the actuator and outputting a signal for inhibiting operation of the actuator to the control means.