JPH0435555Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a first idle device for an LPG engine. Note that the term "fast idle device" refers to an idle device intended to improve the startability of the engine at low temperatures and to prevent the engine from stalling.

(Prior art) Generally, engines that use gasoline as fuel are equipped with a choke mechanism as a means of temporarily supplying a rich mixed gas when starting the engine, thereby speeding up the warm-up time of the engine. It's becoming like that. On the other hand, in engines that use LPG as fuel, it is difficult to supply the appropriate gas mixture using the chiyork mechanism due to the structure of the fuel system (regulator, carburetor).
LPG-specific engines usually do not have a chiyoke mechanism.

(Problems that the invention aims to solve) For the above reasons, LPG engine cars have poor warm-up performance and take a long time to warm up, especially at low temperatures. There is a problem that the engine will stop unless you keep pressing the accelerator pedal until the plane is ready. Therefore, when working on industrial vehicles such as forklifts and shovel loaders equipped with LPG engines, it is necessary to work on them while depressing the accelerator pedal after starting the engine, or wait for it to warm up before starting work. Nakatsuta.

Therefore, an object of the present invention is to provide a fast idle device for an LPG engine that can eliminate the above-mentioned conventional problems.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a first idle device for an LPG engine that moves the throttle valve to the opening side separately from the throttle valve actuation system by the accelerator pedal. While installing an electromagnetic solenoid to operate, a water temperature detector for detecting water temperature is installed in the engine, and when the water temperature is below a set value on the low temperature side, the electromagnetic solenoid is actuated by a signal from the water temperature detector. The opening of the throttle valve is increased from the normal idle opening, and when the water temperature exceeds a set value on the high temperature side, the operation of the electromagnetic solenoid is stopped and the throttle valve returns to the normal idle opening. It is characterized by

(Function) The first idle device for an LPG engine configured as described above responds to a signal from the water temperature detector that detects this when the engine water temperature is lower than the set value on the low temperature side when the engine is started. Based on this, the electromagnetic solenoid is activated and acts to make the opening of the throttle valve larger than the normal idling opening. When the water temperature rises and exceeds the high temperature set value, the electromagnetic solenoid stops operating.
The throttle valve returns to its normal idle opening.

(Example) In addition, when restarting the engine after stopping it once, or when starting it in a high outside temperature such as in the summer, if the engine water temperature is higher than the low temperature setting value, the above It does not operate.

Embodiments of the present invention will be specifically described below with reference to the drawings. In Fig. 1, 1 is a carburetor, 2 is a throttle valve, 3 is a torsion spring that always acts to close the throttle valve 2, and 4 is an accelerator link connected to the shaft of the throttle valve 2. , one end is connected to an accelerator operating member (not shown) such as an accelerator pedal or an accelerator lever, for example, by a cable 5.

Reference numeral 6 denotes a first idle electromagnetic solenoid attached to the carburetor 1 via a suitable bracket (not shown), and its actuator 6a
is opposed to one end of the accelerator link 4 so as to be able to approach and separate from it, and when actuated, the actuator 6a protrudes and pushes the accelerator link 4 in the valve opening direction. That is, the electromagnetic solenoid 6 is assembled independently from the valve operating system. Furthermore, a water temperature detector for detecting the water temperature of the engine is installed on the engine side for controlling the electromagnetic solenoid, and in this embodiment, this water temperature detector includes two water temperature switches 7, one for low temperature and one for high temperature. It consists of 8.

As shown in FIG. 2, the electromagnetic solenoid 6 and two water temperature switches 7 and 8 are connected in series to a battery 10 via a key switch 9.
The low-temperature water temperature switch 7 is set to turn ON when the engine water temperature is below the set temperature on the low-temperature side (for example, 30°C), and is set to turn OFF when it is higher than that. It is set to turn on when the temperature is below a set temperature (e.g. 80°C) and turn off when it is above that temperature. Further, a self-holding relay R is connected in parallel to the electromagnetic solenoid 6, and a normally open contact Ra of the relay R is connected in parallel to a water temperature switch 7 for low temperature.

This embodiment is configured as described above,
When the engine water temperature is low (below 30℃), switch the water temperature switch 7 for low temperature and the water temperature switch 8 for high temperature.
are both ON. Therefore, if you operate the key switch 9 to start the starter and start the engine in this state, when the key switch 9 returns to the ON position (ignition position) after starting the engine, the electromagnetic solenoid 6 will be energized. Therefore, the actuator 6a of the electromagnetic solenoid 6 protrudes, pushes the accelerator link 5, and rotates the throttle valve 2 in the opening direction. That is, since the throttle valve 2 has a larger opening than the normal idling opening, the engine is operated at a higher rotational speed than the normal idling. At this time, relay R is also energized and its normally open contact Ra is ON.
becomes.

However, when the engine water temperature rises and exceeds the set temperature on the low temperature side, the low temperature water temperature switch 7 is activated.
It turns OFF, but at this time the normally open contact of relay R
Since Ra is in the ON state, the operation of the electromagnetic solenoid 6 is maintained. When the water temperature exceeds 80°C, which is the set temperature on the high-temperature side, the high-temperature switch 8 for high temperature is turned off and the power to the electromagnetic solenoid 6 is cut off.
a pulls in and leaves the accelerator link 4. Therefore, the throttle valve 2 is returned to its normal idle opening degree by the action of the torsion spring 3, and the rotation of the engine is reduced to the normal idle rotation speed.

This device will not operate if the water temperature at engine start is higher than the set temperature on the low temperature side, and when the electromagnetic solenoid 6 is in the non-operating state,
Opening and closing of the throttle valve 2 by external operation performed from the accelerator pedal via the cable 5 is not hindered in any way.

In this embodiment, two water temperature switches 7 and 8, one for low temperature and one for high temperature, are used as water temperature detectors, but the present invention is not limited to this. For example, a thermistor can be used as a temperature sensor to detect changes in water temperature. It is possible to change the form so that the electromagnetic solenoid 6 is controlled ON/OFF via an external circuit based on a resistance change corresponding to the resistance change. Furthermore, the set temperatures on the low-temperature side and the high-temperature side of the water temperature are merely examples, and are not limited thereto. Furthermore, the object of operation of the electromagnetic solenoid 6 for fast idle is not limited to the accelerator link 4; the point is that when it is not activated, it does not interfere with the external operation of the throttle valve 2, and when it is activated, it does not interfere with the external operation of the throttle valve 2. There is no problem as long as the structure can be rotated.

(Effect of the invention) As detailed above, according to the invention, LPG
When starting an engine that uses fuel as fuel, the throttle valve opening can be made larger than the normal idling opening to increase the idling speed, so there is no need to keep pressing the accelerator pedal, etc. like in the past. In addition to solving the problem of the engine stopping when the engine stops, it also improves warm-up performance and shortens the warm-up time.
Also, when applied to LPG engines of industrial vehicles,
This makes it possible to carry out cargo handling operations without having to warm up the system, which helps improve work efficiency.

Furthermore, in the device of the present invention, the electromagnetic solenoid is operated to increase the opening of the throttle valve when the engine water temperature is below the low temperature set value, and this operation is continued until the water temperature reaches the high temperature set value. It is something.

In other words, the electromagnetic solenoid is controlled by two set values, a low temperature set value and a high temperature set value. Therefore, if the water temperature exceeds the low temperature set value when the engine is started, , the electromagnetic solenoid will not operate. Therefore, simply 1
Compared to a control method based on two set values, the water temperature is relatively high when restarting after an interruption in operation or when starting in high outside temperatures such as in the summer. When the value is within the range, it is possible to avoid unnecessary increases in idle speed, which is effective in improving fuel efficiency.

This is particularly effective in the case of industrial vehicles, such as forklifts, where the engine frequently starts and stops.

[Brief explanation of the drawing]

FIG. 1 is a front view showing an embodiment of the fast idle device of the present invention, and FIG. 2 is an electric circuit diagram for controlling an electromagnetic solenoid. 1... Carburetor, 2... Throttle valve, 4... Accelerator link, 6... Electromagnetic solenoid, 7, 8... Water temperature switch.

Claims (1)

[Scope of utility model registration request] An electromagnetic solenoid is installed to operate the throttle valve to the open side, separate from the throttle valve actuation system by the accelerator pedal, and a water temperature detector is installed in the engine to detect the water temperature, and the water temperature is set to the low temperature side. When the water temperature is below a set value on the high temperature side, the electromagnetic solenoid is activated by a signal from the water temperature detector to increase the opening of the throttle valve from the normal idle opening, and when the water temperature exceeds a set value on the high temperature side, the electromagnetic solenoid is activated. The first idle device for an LPG engine is configured to stop the throttle valve and return the throttle valve to a normal idle opening.