JPS6045760A - Starting device of internal-combustion engine - Google Patents

Abstract

PURPOSE:To surely supply starting fuel by electrically heating the auto-starter part of a carbureter. CONSTITUTION:When an engine is started, a suction pressure is induced via a suction pressure delay valve 20 into the chamber 16b of a diaphragm 16c to suck it against the force of a spring 16a. The rod on the diaphragm is therefore lifted to close a switch 16. Since a key switch 18 remains closed, a heater 14 carries a current to heat a thermo-wax 8. The thermo-wax 8 is expanded to push the end part of a rod which has an operating cam face at the other end thereof, whereby gradually closing a starting fuel supply valve. The starting fuel is kept to be supplied until the valve is closed completely. The heating under electrical control may provide reliability for the operation of a starting device in comparison with the ordinary heating performed by means of a heat pipe.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to an improvement in a starting device for an internal combustion engine, and more particularly, the invention relates to an improvement in a starting device for an internal combustion engine, and in particular, the heating of a temperature-sensitive wax in an auto starter (starting device) controlled by a temperature-sensitive wax is heated by electric heating. This invention relates to an autostarter for a carburetor of an internal combustion engine.

[Technical Background of the Invention] In an internal combustion engine such as a gasoline engine, an air-fuel mixture is created by mixing an appropriate amount of atomized or vaporized fuel with intake air.
It is sucked into a cylinder and combusted to generate power. The amount and mixture ratio of the air-fuel mixture must be appropriate depending on the operating condition of the engine. In particular, when the engine is started, temperature and other conditions are bad, and the operating conditions change rapidly over time, so it is necessary to quickly respond to this and supply an appropriate air-fuel mixture. A vaporizer is responsible for this difficult and important function.

The auto scooter (starting device) creates and supplies a rich mixture to the main passage of the carburetor when starting the engine, and aims to achieve the same effect as a commonly used choke valve. .

The present invention relates to an improvement in an autostark provided in a variable Henchuri type carburetor of, for example, a two-wheeled vehicle engine.

An example of a carburetor having an autostarter is shown in FIG. The autostarter plunger 2 is pushed up by a spring 4.6 when the engine is started (in a cold state), opens a passage for fuel and air-fuel mixture, and supplies a rich air-fuel mixture to the cylinder. As the engine warms up, the plunger 2 is pushed down by the wax piston 10 pushed out by the expansion of the temperature-sensitive wax 8, closing the fuel and mixture passages, and the autostarter stops supplying the rich mixture, and the mixture main passage Only the air-fuel mixture will be supplied.

Conventionally, a heat pipe 12 is used as a heat source for the temperature-sensitive wax 8 that controls the operation of the autostarter, and the heat pipe 12 is led from the cylinder head to the temperature-sensitive wax 8 to serve as a heat source for heating the temperature-sensitive wax 8.

[Problems with Background Art] However, in heating using a heat pipe, the amount of heating cannot be set very freely. In addition, heat pipes have a restriction that the heat transfer efficiency will decrease unless the low-temperature section is installed above the high-temperature section, so if a cylinder head is used as the heat source of the heat pipe, the vaporizer must be installed above the cylinder head. There is an additional restriction on the engine layout that it cannot be used. Although it is possible to use a heat source other than the cylinder head, this is disadvantageous in terms of structure since the temperature is not as high as that of the cylinder head.

[Purpose of the Invention] Therefore, the purpose of the present invention is to use an electric heater as a heat source for the temperature-sensitive wax in the internal combustion engine carburetor, thereby making it possible to freely set the engine layout and appropriate heating timing and heating amount. That is.

[Structure of the Invention] To achieve this object, the present invention is characterized in that, in a carburetor of an internal combustion engine having an auto scooter section controlled by a temperature sensing element, the heating means for the temperature sensing element is an electric heating type. shall be. Further, the electric heating method is characterized in that the circuit is configured to close after a delay time after the engine is started.

Further, the electric heating method is characterized in that the circuit is provided with a mechanism for preventing overheating of the temperature sensitive body.

[Embodiments of the Invention] The present invention will be described in detail below based on the drawings. FIG. 1 shows a conventional vaporizer with an auto starter, in which a heat pipe 12 serves as a heat source for temperature-sensitive wax 8 to heat and expand the wax, control the positions of a wax piston 10 and a starter plunger 2, and control the auto starter. It controls the operation and functions of the

FIG. 2 shows an embodiment of an auto scooter in which an electric heater according to the present invention is used as a heat source for temperature-sensitive wax in place of the conventional shield pipe.

The temperature-sensitive wax 8 is heated by an electric heater 14 disposed around the outer periphery of a wax pod 8a containing the wax. Of course, this electric heater 14 may be inserted into the wax 8 as a sheathed heater to prevent electric heat loss.

The electric heater circuit in Figure 2 includes a boost switch 1.
6 is provided, and even if the engine start switch 18 is closed and the engine is started, the boost switch 16 is normally biased downward by the spring 16a and is in the circuit state, so the power is not immediately turned off. No electricity flows through the heater circuit.

When the engine starts rotating, the intake passage becomes negative pressure, and the pressure of the negative pressure transmission delay valve 20 connected to the intake passage through a pipe gradually becomes negative and positive, and the boost switch 16 connected to it gradually becomes negative pressure.
The upper chamber 16b becomes a negative pressure, the contact is pushed up against the spring 16a by the diaphragm 16C, the boost switch 16 is closed, electricity flows to the electric heater 14, and heating of the wax is started. After the engine starts and negative pressure is generated in the intake pipe until the boost switch 16 closes,
The negative pressure transmission delay valve 20 is set to delay its operation. This closes the heater circuit after confirming that the engine has started completely.
If the engine fails to start or if the key is left in the engine and the engine does not start, do not allow electricity to flow to the heater circuit, and try to close the heater circuit while the generator is spinning sufficiently and there is no need to worry about the power supply. It is something to do.

FIG. 3 shows another delay time setting method provided in this electric heater circuit. After the engine starts, as the engine speed increases, the generator generated voltage increases, and when it reaches a certain threshold, the generator generated voltage signal enters the electrical delay circuit, and the electronic timer starts operating, and after a certain number of seconds. The timer is completed and the heater circuit is closed. Therefore, if the engine is stopped within this delay time, the voltage signal from the generator disappears, the electrical delay circuit stops operating and returns to its original state, and the electrical heater circuit will not close. After the engine is started again and it is confirmed that the generator has rotated for more than the delay time, electricity will flow to the heater circuit, so that the engine can be started reliably.

Next, before explaining Fig. 4, when heating temperature-sensitive wax with an electric heater, if the amount of heat generated by the heater is small, the temperature of the wax will rise slowly and the starter will work for a long time after starting, and the choke state will not stop. As a result, a so-called over-choke condition occurs, causing the engine to stall, the plug to shake,
Negative effects such as increased fuel consumption occur. On the other hand, if the heater generates a large amount of heat, the thermal response of the O1-starter improves, but the maximum temperature of the wax becomes high, which poses a problem in terms of the wax's secondary properties. Taking this point into consideration, it is necessary to appropriately set the amount of heat generated by the heater. In order to solve this problem, FIG. 4 shows an embodiment of means for setting the heat generation amount of the heater to a high value and canting it when unnecessary.

In FIG. 4, an overtemperature switch 22 is connected in series with the heater circuit.
will be established. The overheating switch 22 is activated when the temperature of the wax 8 increases, the wax piston 10 is pushed out, the starter switch plunger 2 is pushed down, and the starter is fully closed, and then the temperature of the wax 8 further increases and the wax piston 10 is pushed out. When this occurs, the overheating switch 22 is pushed up to open the circuit and no electricity flows through the heater circuit, thereby preventing unnecessary electrical heat from being applied and deterioration of the wax. Moreover, if this overheating switch 22 is provided,
The amount of heat generated by the heater can be determined by considering only the thermal responsiveness of the wax so that the starting device operates properly, and problems such as over-choking can also be solved.

Although not shown, more appropriate and economical control can be achieved by inserting a variable resistor into this electrical circuit and manually or automatically setting the current value depending on the outside temperature and other conditions. .

Furthermore, it is of course possible to reduce electricity consumption by using conventional heat pipe heating in combination with the electric heater heating according to the present invention.

[Effects of the Invention] As described in detail above, according to the present invention, the following effects can be achieved.

(1) Since the temperature-sensitive wax is heated by an electric heater, the engine layout can be freely designed.

Further, since the heating amount of the electric heater can be freely set, the operating amount, operating time, etc. of the starter can be freely set as desired, so that a good engine operating state can be obtained.

(2) With electric heaters that close the electric circuit after a delay after the engine starts, the heater circuit closes after confirming that the engine has started completely, so if you forget to put the key in. If the engine stalls repeatedly, raising the pantry can prevent problems such as poor starting.

(3) If the heater circuit is opened and closed in response to the operation of the temperature sensor to prevent overheating, the thermal responsiveness of the wax can be increased, unnecessary current can be canted, and wax deterioration can be prevented. It can be prevented.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway sectional view of a carburetor with a conventional starting device, Fig. 2 is a sectional view of a starting device according to the present invention, Fig. 3 is a graph of an electric heater delay circuit, and Fig. 4 is a graph of the invention. FIG. 3 is a sectional view of another embodiment of the invention. In the figure, 2 is a starter plunger, 8 is a temperature-sensitive wax, 10 is a wax piston, 12 is a heat pipe, 1
4 is an electric heater, 16 is a boost switch, 18 is a key switch, 20 is a negative pressure transmission delay valve, and 22 is an overheating switch.

Claims (1)

[Scope of Claims] 1. A starting device for an internal combustion engine, characterized in that a carburetor for an internal combustion engine has an auto starter section controlled by a temperature sensing element, characterized in that heating means for the temperature sensing element is of an electric heating type. 2. The internal combustion engine starting device according to claim 1, wherein the electric heating method is configured to close the circuit after a delay time after the engine is started. The starting device for an internal combustion engine according to claim 1, wherein the electric heating method is an electric heating method in which a circuit is provided with a mechanism for preventing overheating of a temperature sensitive element.