JPH0361659A - Start-up assisting device for engine - Google Patents

Abstract

PURPOSE:To start an engine which uses kerosene, alcohol, etc., as fuel without using auxiliary fuel by installing a heat storage body in an intake passage between a caburetor and a combustion chamber and heating the heat storage body. CONSTITUTION:A start assisting device 10 is arranged in an intake passage 40 between a carburetor 20 and the combustion chamber 31 of an engine body 30, and has a heating block 11 as heat storage body and a heat shielding body 12 installed on the periphery of the heating block 11, and a glow plug 14 is screwed onto the lower part side of the heat shielding body 12, and when the glow plug 14 is put into electric conduction, the heating block 11 is heated. Therefore, the engine which uses the fuel having the low evaporation perfor mance such as kerosene can be started without using the auxiliary fuel such as gasoline. Further, since fuel is evaporated by the stored heat energy of the heat storage body, the lowering of temperature is prevented even if the fuel having a low temperature acts onto the heat storage body, and the engine can be provided with the superior starting performance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a starting assist device for an engine that uses kerosene, alcohol, or the like as fuel.

[Conventional technology]

Some outboard motors use kerosene engines that use kerosene as fuel.

As is well known, kerosene is less volatile than gasoline.

Therefore, in conventional kerosene engines, a highly vaporizable auxiliary fuel such as gasoline is used to start the engine, and the fuel is switched to kerosene when the engine is sufficiently warmed up.

[Problem to be solved by the invention]

However, when auxiliary fuel is used as a starting means, two types of fuel must be prepared, which is complicated.

In view of this situation, an object of the present invention is to provide a kerosene slave device.

[Means to solve the problem]

The starting assist device according to the present invention includes a heat storage body disposed in an intake passage located between a carburetor break and a combustion chamber, and a heating means for heating the heat storage body.

[Effect]

Fuel flowing out from the carburetor is vaporized by the heat storage energy of the heat storage body, and this vaporized fuel is supplied to the combustion chamber.

Embodiment f] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of a starting assist device according to the present invention applied to an outboard motor that uses kerosene as fuel.

This starting assist device 10 is disposed in an intake passage 4o located between a carburetor brake 20 and a combustion chamber 31 of an engine body 30, as shown in FIG.

As shown in FIG. 1, this starting device 1o includes a heating block 11, which is a heat storage body, arranged along the intake passage 40, and a heat insulator 12 provided around the heating block 11. have.

The heating block 11 is made of aluminum or aluminum alloy, and is provided with a groove 11a having a semicircular cross section along the intake passage 40 on its upper surface.

On the other hand, the heat insulator 12 is made of ceramic, and is provided with a grooved line 12g having a semicircular cross section at a portion of the heating block 11 that faces the grooved line 11a.

Each of the grooves 11a and 12a constitutes a passage 13 having a circular cross section by its inner peripheral surface, and the entrance of the passage 13 is connected to the intake passage 40 on the side of the carburetor 20 shown in FIG. are respectively connected to passages 40 on the combustion chamber 31 side shown in the figure.

When connecting the passage 13 and the intake passage 40 on the side of the combustion chamber 31, a gasket 50 made of rubber or the like is inserted between them.
is intervened. This gasket 50 has an opening 51 that has approximately the same diameter as the passage 13 and has a wall portion 51a formed at the bottom thereof. Therefore, when this gasket 50 is installed, the wall portion 51a is formed at the bottom of the exit of the passage 13. It will stand out.

Note that, as described later, this wall portion 51a functions as a baffle plate that prevents fuel from flowing out.

A plurality of glow plugs 14 serving as heating elements are screwed onto the lower side of the heat insulating body 12. Each of these glow plugs 14 has a heater (not shown) attached to its tip located within the heating block 11, so that when the glow plugs 14 are energized, the heating block 11 is heated.

As will be described later, the pump 15 shown in FIG. 1 is used as a means to compensate for a fuel shortage in the passage 13 when starting the engine, and is connected to the passage 13 via a pipe 16.

FIG. 3 illustrates means for controlling the glow plug 14 and pump 15. In the figure, a temperature sensor 101 detects the outside air temperature around the engine, and a temperature sensor 102 detects the heat generation temperature of the heating block 11. Further, the voltage detection unit 103 receives the generated voltage of an alternator (not shown) operated by the engine, and detects that a starting operation has been performed.

In this embodiment, a thermocouple is used as the temperature sensor 102.

The operation of this embodiment will be explained below.

Now, when the push button switch 104 for starting preheating is operated after turning on the power switch (not shown), a flip-flop (hereinafter abbreviated as FF) 105 is set and its Q
The logic level of the output becomes "1".

As a result, a switch element 106 such as a transistor is closed, and energization to the glow plug 14 is started via this switch element 106. By energizing the glow plug 14, the temperature of the heating block 11 is gradually increased, and this temperature is detected by the temperature sensor 102.

By the way, when the outside temperature is low, the temperature of the kerosene flowing into the passage 13 via the carburetor 20 is also low. Therefore, in this case, it is necessary to set the heating temperature of the heating block 11 high in order to promote the vaporization of kerosene. on the other hand,
On the contrary, if the outside temperature is high, the heating block 11
The temperature may be set lower than when the temperature is low.

A comparison unit 107 to which the output signals of the temperature sensors 101 and 102 are applied sets a target temperature of the heating block 11 that matches the outside temperature detected by the sensor 101, and compares this target temperature with the heating block 11 detected by the sensor 102. The function is to compare the temperature of

That is, for example, if the outside temperature is about 20°C, the target temperature is set to about 280°C, and if the outside temperature is about 120°C.
If the target temperature is approximately 350° C., the target temperature is compared with the temperature detected by the sensor 102.

When the temperature of the heating block reaches the target temperature due to the heat generation action of the glow plug 14, a heating completion signal is output from the comparator 107, which sets the FF 108 and sets the logic level of its Q output to "1". Become.

A motor drive circuit 109, a switch element 110, and a timer 112 are connected to the Q output of the FF 108, respectively.

1 (3) When the FF 108 is set, the pump drive circuit 109 operates the pump 15 for a short period of time, thereby supplying kerosene equivalent to an ice cube into the passage 13.Then, this kerosene is heated to the target temperature. It is vaporized by a heated heating block.

In addition, with the setting operation of the FF 108, the switch element 1
10 is closed, the start ready lamp 111 is lit, and at the same time, the timer 112 is activated.

After confirming that the start ready lamp 111 is lit,
When the outboard motor glue coil starter is pulled, the kerosene already vaporized in the passage 13 and the kerosene introduced into the passage 13 from the carburetor 20 and vaporized are introduced into the combustion chamber 31 of the engine shown in FIG. This will start the engine.

Note that, since the heating block 11 has a heat storage function, even if -kerosene is introduced into the passage 13, a significant temperature drop does not occur.

The voltage detection unit 103 creates a trigger signal based on the output voltage of an alternator (not shown) generated in conjunction with the operation of the recoil starter, and causes this trigger signal to act on the timer 113.

Therefore, the timer 113 is started almost simultaneously with the operation of the recoil starter.

The timer 113 outputs a time-up signal indicating the completion of starting the engine after the time (for example, 2 minutes) has passed, and this signal is sent to the FF 105 via the OR circuit 114.
and is added to FF 108 as a reset signal.

Thus, after the engine is started, the FFs 105 and 108 are reset together, and as a result, the supply of electricity to the glow plug 14 is stopped and the start ready lamp 111 is turned off.

By the way, if the coil starter is not operated for a long time after the start preparation section lamp 111 is lit, the FFs 105 and 108 are reset by the action of the timer 112.

In other words, the timer 112 is activated when preparations for starting are completed, and thereafter, it measures a set time (for example, 2 minutes), but if a starting operation is performed by the recoil starter during this timing operation, the timer 112 will time out. It is reset by the output signal of the voltage detection section 103 before. Therefore, only when the starting operation is not performed within the time set by the timer 112 after the start preparation is completed, the timer 112 outputs a time-up signal, and this time-up signal is sent to the FF 105 and FF108
to be reset.

Thus, according to this embodiment, the inconvenience that the glow plug 14 is operated to generate heat for a long time because the starting operation is not performed can be avoided.

By the way, in the above embodiment, a small amount of kerosene is supplied into the passage 13 by the pump 15 before starting in order to improve the startability, but it is also possible to improve the startability without using the pump 15. For example, starting performance can be improved by pressurizing the fuel tank or lowering the float of the carburetor to cause fuel to overflow from the carburetor brake at the time of starting.

Of course, if sufficient air-fuel mixture can be introduced into the passage 13 at the initial stage of startup by operating the recoil starter, the pump 1
It is also possible to omit the 5th grade.

Further, in the above embodiment, as shown in FIG.
The gasket 50 equipped with a is used to prevent the low-temperature air-fuel mixture from directly flowing into the engine at the initial stage of startup. In other words, the low-temperature air-fuel mixture is heated by heating pro 1. Since the air-fuel mixture tends to pass over the four grooves 11a of the air-fuel mixture 11, by using the gasket 50 having the wall portion 51a, it is possible to prevent this low-temperature air-fuel mixture from flowing into the combustion chamber 31.

Note that instead of providing the wall portion 51a, one or more wavy protrusions may be provided on the upper surface of the heating block 11. In this case, the wavy protrusions are parallel to the end surface of the heating block 11. It is formed. In the above embodiment, the starting operation is detected using the output voltage of the alternator, but it is of course possible to detect the starting operation based on the engine speed, and in this case, the output of the engine speed sensor is used to detect the starting operation. is applied to the voltage detection section 103.

The starting assist device of the above embodiment can quickly start the engine without using auxiliary fuel such as gasoline, and can start the engine in about 90 seconds at an outside temperature of -20° C., for example.

The present invention is effective not only for kerosene engines but also as a starting device for diesel engines, engines using alcohol fuel, etc.

〔Effect of the invention〕

According to the present invention, an engine that uses a fuel with low vaporizability such as kerosene can be started without using an auxiliary fuel such as gasoline. Moreover, since the fuel is vaporized using the heat storage energy stored in the heat storage body, even if low-temperature fuel acts on the heat storage body, the temperature decrease is small, and therefore good startability can be imparted to the engine.

[Brief explanation of drawings]

Fig. 1 is a perspective view conceptually showing an embodiment of the starting aid device according to the present invention, Fig. 2 is a conceptual diagram showing the arrangement position of this starting aid device, and Fig. 3 is the energization time of the glow plug. FIG. 2 is a block diagram showing an example of means for controlling the above. 10... Starting aid device, 11... Heating block, 1
1a, 12a...concave stripe, 12...insulator, 13...
・Passage, 14...Glow plug, 15...Pump,
20... Carburetor, 30... Engine body, 3
DESCRIPTION OF SYMBOLS 1... Combustion chamber, 40... Intake passage, 50... Packing, 51a... Wall part, 101, 102... Temperature sensor, 103... Voltage detection part, 105, 108...
Flip-flop, 105.110...Switch element, 107...Comparison section, 111...Start preparation completion lamp, 112, 113...Timer. Applicant Suzuki Automobile Industry Co., Ltd.

Claims (1)

[Scope of Claims] An engine starting assist device comprising: a heat storage body disposed in an intake passage located between a carburetor and a combustion chamber; and heating means for heating the heat storage body.