JPS6363738B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a starting device for a carburetor that supplies a starting mixture to an engine using a carburetor. The first purpose is to improve starting performance by supplying injection into the intake tract, and the second purpose is to automatically operate the starting device to make starting and warm-up operation extremely easy. In addition, the third objective is to automatically reduce the mixture concentration during startup and warm-up after the engine has completely exploded, thereby improving engine warm-up performance and making it easier to operate. purpose.

An embodiment of the first invention will be described below with reference to FIG.

Reference numeral 1 denotes a carburetor main body which includes a mixing body 4 through which an intake passage 2 passes vertically, a mixing body 4 having a ventilate 3 in the middle thereof, and an air horn 6 having an opening 5 corresponding to the intake passage 2. be. A float chamber body 7 is formed on the right side of the mixing body 4, and the fuel in the fuel source is always stored and maintained at a constant liquid level XX by a float 8 and a float valve (not shown). be done. A crest valve 9 is rotatably supported on a shaft 10 in the intake passage 2 on the downstream side of the ventilator 3, and a constant liquid in the float chamber body 7 is supplied to the ventilator 3 through a mixing tube 11 and a main jet 12. The main nozzle 13 connected to the lower surface XX protrudes and opens.

A cylindrical starting fuel pump chamber 14 is formed in the side of the float chamber body 7, and this starting fuel pump chamber 14 is connected to the float via a starting fuel inlet passage 16 in which a fuel control jet 15 is disposed. It is connected to the chamber body 7 under a constant liquid level, and is also connected to the intake passage 2 via a starting fuel discharge passage 18 in which a discharge side check valve 17 is disposed.

The air horn 6 has a cylindrical control chamber 19.
A starting air passage 20 communicating with the atmosphere and a starting air mixture passage 21 communicating with the intake passage 2 are opened in the side wall of the control chamber 19. A starting control valve 22, which will be described later, is disposed in the starting fuel pump chamber 14 and the control chamber 19. That is, the starting control valve 22 is arranged in the starting fuel pump chamber 14, and the pump section 2 provides a pumping action to the starting fuel pump chamber 14.
3 and a starting air passage 20 arranged in the control room 19.
A control passage section 24 is integrally formed to communicate and cut off the starting mixture passage 21 and the starting fuel pump chamber 14. The starting control valve 22 is operated by an operating rod 27 via a check valve spring 28.

That is, the operating rod 27 is connected to the fuel passage section 2 from the outside.
The lower end of the check valve spring 28 presses the check valve 25, and the other end passes through the control chamber 19 and connects the air horn 6.
protrude to the outside of the body.

Furthermore, reference numeral 29 indicates that the check valve 25 is mechanically connected to the fuel passage section against the force of the check valve spring 28 at the end of the movement of the pumping action in which the pump section 23 of the starting control valve 22 pressurizes the starting fuel pump chamber 14. Starting fuel pump chamber 1 to open 26
It is an open rod that protrudes from the bottom of the 30
31 is a control valve spring that is compressed in the starting fuel pump chamber 14 and applies an upward force to the starting control valve 22, and 31 is a control valve spring that urges the discharge side check valve 17 in the closing direction. This spring 31 is a side spring, and its spring force is appropriately set so that the discharge side check valve 17 is opened only when the starting fuel pump chamber 14 is pressurized, and does not open due to negative pressure in the intake passage. do.

Next, the operation of the first invention will be explained.

When the engine is stopped, no operating force is applied to the operating rod 27, so the starting control valve 22
is at the upper limit position as shown in FIG. 1 due to the force of the control valve spring 30, and the control passage section 24 keeps the starting air passage 20 and the starting mixture passage 21 in a disconnected state, and the starting fuel pump chamber Starting fuel is stored in the engine 14 via a starting fuel inflow path 16 .

To start the engine, the driver senses a drop in the engine ambient temperature and presses the operating rod 27 downward against the spring force of the control valve spring 28.

According to this pressing of the operating rod 27, the downward pressing force of the operating rod 27 is transmitted from its lower end to the check valve spring 28, and further transmitted from the check valve 25 to the starting control valve 22. The starting control valve 22 then moves downward.

At this time, the fuel passage section 26 of the check valve 25
Closing force against (check valve spring 28
Since the pressing force (pushing force) is increased by the downward movement of the operating rod 27, the fuel passage portion 26 is kept closed. Therefore, by the downward movement of the starting control valve 22, the starting fuel pump chamber 14 is pressurized by the pump section 23, and this pressurized fuel is pumped against the spring force of the delivery side spring 31 to the opposite side. The stop valve 17 is opened and starting fuel is injected into the intake passage 2 from the starting fuel discharge passage 18 in advance.

When the starting control valve 22 reaches the final stage of its downward movement, the check valve 25 comes into contact with the opening rod 29, so that
Check valve 25 mechanically opens fuel passage 26.

When cranking is performed to start the engine in such a state, the intake passage 2 is
This negative pressure acts on the control passage section 24 from the starting mixture passage 21, so that this negative pressure sucks out fuel from the fuel passage section 26 and draws air out from the starting air passage 20. These mixtures form a starting mixture, which is sucked out into the intake passage 2 through the starting mixture passage 21 and combined with the fuel that has been injected into the intake passage 2 in advance. This makes it possible to supply the engine with a rich air-fuel mixture that is optimal for starting, thereby improving starting performance.

Next, the second invention will be explained with reference to FIG.

(Structures similar to those in FIG. 1 are denoted by the same reference numerals and explanations are omitted.) A movable iron core 42 is disposed corresponding to a fixed iron core 41 in a pipe 40, and a coil 43 is placed around the pipe 40. The electric circuit of the electromagnetic body 44 is connected to a main switch 45 that closes the contacts when the engine is running and opens when the engine is stopped, and a main switch 45 that closes the contacts when the engine is running and opens when the engine is stopped.
A power source 47 and a temperature sensing switch 46, which opens its contacts above a certain temperature and closes below a certain temperature, are arranged in series.

The end portion 4 of the movable core 42 of this electromagnetic body 44
2A and the upper end portion 27A of the operating rod 27 are connected to both ends of a transmission lever 49 whose intermediate portion is rotatably supported by a shaft 48.

According to the second invention, when the main switch 45 is closed in order to start engine operation when the engine ambient temperature is below a certain temperature, the temperature sensing switch 46 is already closed, so no current is applied to the coil 43. As a result, the movable core 42 moves upward. According to the upward movement of the movable iron core, the transmission lever 49 rotates counterclockwise and presses the operating rod 27 downward, and as in the first invention, the starting fuel pump chamber 14 is opened by the pump section 23. By communicating the pressure pump action and starting air mixture passage 21 with the starting air passage 20 and the control passage section 24, it is possible to automatically obtain good starting performance.

Then, when the ambient temperature of the engine rises and the warm-up operation ends, the temperature sensing switch 46 senses the temperature rise and opens its electric circuit, so the electromagnetic body 44
The magnetic attraction force disappears, and the starting control valve 22 moves upward by the spring force of the control valve spring 30, cutting off the starting air mixture passage 21, the starting air passage 20, and the control passage section 24, and starting. This is to cut off the supply of the air-fuel mixture to the engine, and from then on, the air-fuel mixture of the normally set concentration can be supplied to the engine. On the other hand, this starting control valve 2
According to the upward movement of 2, the open holding of the check valve 25 by the release rod 29 is released, the volume inside the starting fuel pump chamber 14 increases, and the pressure inside the chamber decreases, so that the check valve 25 and the discharge side check valve 17 are opened. is closed, and the fuel restricted by the fuel control jet 15 flows from the starting fuel inflow path 16 into the starting fuel pump chamber 14, thereby preparing for the next starting operation of the starting control valve 22.

Next, the third invention will be explained with reference to FIG.

50 is a valve seat 51 that connects an inflow path 52A and an outflow path 52.
A needle valve 54 is disposed corresponding to the valve seat, and the effective area of the valve seat 51 is made variable by a heat-sensitive expansion body 53 that operates by sensing the engine ambient temperature.

The thermosensitive expansion body 53 has a thermal expansion material such as ether or paraffin sealed in a sealed case 55, and an operating rod 56 is hermetically immersed in the case, and the needle valve is attached to the end protruding outside the sealed case 55. 54
Concatenate.

A spring 57 biases the needle valve 54 away from the valve seat 51. The inlet passage 52A and outlet passage 52B of the valve body 50 are connected to the starting mixture passage 21.

When the starting control valve 22 is operated to perform a starting operation as in the first and second inventions, the fuel in the starting fuel pump chamber 14 is injected into the intake passage 2 and the starting mixture passage is injected into the starting fuel pump chamber 14. A system is established in which starting air-fuel mixture can be supplied into the engine 21, and the engine can easily start starting in this state. However, after the engine has completely exploded, it is necessary to gradually reduce the concentration of the starting mixture, and it is desirable to completely cut off the supply of the starting mixture when the warm-up operation ends over time.

According to this third invention, attention is paid to the fact that as the engine warms up over time, the engine ambient temperature increases almost proportionally, and this temperature change is used to expand and contract the thermally expandable material to control the operating rod. 56 to the needle valve 54 as a stroke movement.

Therefore, during engine cranking and complete explosion, the late needle valve 54, where the engine atmosphere temperature is low, opens the valve seat 51 widely and supplies a larger amount of rich mixture than the starting mixture passage 21.

As the engine warms up over time, the engine ambient temperature rises, causing the thermal expansion material to expand and move the operating rod 56 to the left in the figure, causing the needle valve 5
4 reduces the opening of the valve seat 51 and finally closes the valve seat 51 by closing the needle valve 54 as the temperature rises, and gradually dilutes the starting air-fuel mixture during warm-up operation. It is possible to improve the maneuverability of the machine.

As described above, according to the carburetor starting device of the first invention, the starting fuel is communicated with the starting fuel under the constant liquid level of the float chamber body 7 via the starting fuel inflow path 16 and the starting fuel discharge path 18. A pump section 23 that provides a pumping action to the starting fuel pump chamber 14 connected to the intake passage 2 communicates with and shuts off the starting air passage 20 connected to the atmosphere and the starting air mixture passage 21 connected to the intake passage 2. Control passage section 2
4, and a fuel passage section 26 having one end connected to the starting fuel pump chamber 14 via a check valve 25 and the other end opening to the control passage section 24; control valve 22
An operating rod 27 that can apply operating force to the engine and increase the closing force of the check valve 25 when operated, and a control rod 27 that forcibly opens the check valve 25 at the end of the movement of the starting control valve 22 to supply starting fuel. Since the opening rod 29 is provided to maintain open communication between the pump chamber 14 and the fuel passage section 26, the starting control valve can be activated by operating the operating rod 27 when starting the engine at a low engine ambient temperature. 22 is moved to inject and supply starting fuel from the starting fuel pump chamber 14 into the intake passage 2 in advance, and at the same time, the starting air passage 20 and the starting air mixture passage 21 are placed in communication with each other at the control passage section 24. Therefore, when the engine is started, the injected fuel and the starting mixture sucked out from the starting mixture passage 21 are combined to supply a sufficiently rich starting mixture to the engine, and the startability is extremely high. It is reliable and easy.

According to the second invention, in addition to the first invention, since the electromagnetic body 44 is connected to the operating rod 27, the electromagnetic body 44 is automatically energized when the engine is started in a state where the engine ambient temperature is low. In particular, the degree of freedom in operating the operating rod 27 has been increased, and operability has been improved in products such as outboard motors that require remote control operation.

Furthermore, if a temperature sensing switch 46 is disposed in the electric circuit of the electromagnetic body 44, the starting control valve 22 can be automatically reset, and the operability is further improved. Problems such as engine stoppage and deterioration of fuel economy due to over-concentration of the air-fuel mixture due to forgetfulness can be completely eliminated.

Further, according to the third invention, since the heat-sensitive expansion body 53 is disposed in the starting mixture passage 21 of the first invention, in addition to the first effect, it is possible to reduce the time during warm-up operation after starting the engine. As the engine temperature rises, the amount of starting mixture flowing into the starting mixture passage 21 is gradually reduced, the starting mixture concentration is gradually reduced, and the warm-up At the end of the operation, the supply of the starting mixture from the starting mixture passage 21 can be cut off to maintain the mixture concentration at the normal setting, so warm-up operation can be made extremely good, especially during warm-up operation. It is possible to accelerate the engine inside the engine, and can be expected to significantly improve drivability.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of a starting device for a carburetor according to the present invention, FIG.
FIG. 3 is a longitudinal sectional view of a main part of an embodiment of a starting device for a carburetor showing the third invention. 2... Intake path, 7... Float chamber body, 16... Fuel inflow path for starting, 18... Fuel discharge path for starting, 20... Air passage for starting, 21...
Starting mixture passage, 24... Control passage section, 25...
...Check valve, 26...Fuel passage section, 29...
...Open rod, 44...Electromagnetic body, 53...Thermosensitive expansion body.

Claims (1)

[Claims] 1. A fuel control jet 15 is provided inside, a starting fuel inflow path 16 is connected to a constant liquid level below the float chamber body 7, and a discharge side check valve 1 is provided inside.
7, and a starting fuel discharge passage 18 connected to the intake passage 2 on the engine side via the throttle valve 9; and a starting fuel pump chamber 14 having an opening therein; a starting air passage 20 having one end connected to the atmosphere;
and a starting mixture passage 21 whose one end is connected to the intake passage 2 on the engine side from the throttle valve 9; 23 and starting air passage 20
and a control passage section 24 that controls communication and disconnection between the engine and the starting mixture passage 21, one end of which opens into the starting fuel pump chamber 14 via a check valve 25, and the other end of which opens into the control passage section 24. a starting control valve 22 comprising: a fuel passage section 26; which applies an operating force to the starting control valve 22 and elastically absorbs the closing force of the check valve 25 disposed in the fuel passage section 26 during the pressing operation; The operating rod 27 increased by the member; The check valve 25 is forcibly opened at the end of the pressing movement of the starting fuel pump chamber 14 by the pump part 23 of the starting control valve 22, and the starting fuel pump chamber 1 is opened.
4 and the fuel passage section 26 in communication with each other, and the operating rod 27 is used to control the starting control valve 22 at the beginning of the pressing movement of the starting fuel pump chamber 14 by the pump section 23 of the starting control valve 22. The air passage 20 and the starting mixture passage 21 are cut off by the control passage part 24, and the control passage part 24 and the starting fuel pump chamber 14 are cut off by the check valve 25. On the other hand, the operating rod 27 causes the starting air to be pumped at the end of the press movement of the starting fuel pump chamber 14 by the pump section 23 of the starting control valve 22. aisle 20
The starting fuel pump chamber 14 and the control passage 24 are brought into communication with each other through the control passage 24, and the check valve 25 is forcibly opened using the opening rod 29. Fuel passage section 26
A starting device for a carburetor that is maintained in communication via a. 2. A fuel control jet 15 is provided inside, a starting fuel inflow path 16 is connected below a constant liquid level of the float chamber body 7, and a discharge side check valve 1 is provided inside.
7, and a starting fuel discharge passage 18 connected to the intake passage 2 on the engine side via the throttle valve 9; and a starting fuel pump chamber 14 having an opening therein; a starting air passage 20 having one end connected to the atmosphere;
and a starting mixture passage 21 whose one end is connected to the intake passage 2 on the engine side from the throttle valve 9; 23 and starting air passage 20
and a control passage section 24 that controls communication and disconnection between the engine and the starting mixture passage 21, one end of which opens into the starting fuel pump chamber 14 via a check valve 25, and the other end of which opens into the control passage section 24. a starting control valve 22 comprising: a fuel passage section 26; which applies an operating force to the starting control valve 22 and elastically absorbs the closing force of the check valve 25 disposed in the fuel passage section 26 during the pressing operation; The operating rod 27 is increased by the member; At the end of the pressing movement of the starting fuel pump chamber 14 by the pump part 23 of the starting control valve 22, the check valve 25 is forcibly opened to open the starting fuel pump chamber 1.
4 and the fuel passage section 26 in a communicating state; and an open rod 29 that is made up of a fixed iron core 41, a movable iron core 42, and a coil 43 surrounding both iron cores, and a contact point is closed in the electric circuit of the coil 43 when the engine is operating; A main switch 45 that opens when the engine is stopped, a temperature sensing switch 46 that opens its contacts when the engine ambient temperature is above a certain temperature, and closes when it is below a certain temperature, and a power source 47 are arranged in series, and an electromagnetic body that is connected to the operating rod 27. 44
As the electromagnetic body 44 is driven, the operating rod 2
7, at the beginning of the pressing movement of the starting control valve 22 against the starting fuel pump chamber 14 by the pump section 23, the starting air passage 20 and the starting air mixture passage 21
The control passage section 24 shuts off the control passage section 24 and the starting fuel pump chamber 14, and the check valve 25 shuts off the control passage section 24 and the starting fuel pump chamber 14. On the other hand, when the electromagnetic body 44 is driven, the operation rod 27 causes the pump part 23 of the starting control valve 22 to act as a pressure pump.
At the end of the pressing movement against the starting fuel pump chamber 14, the starting air passage 20 and the starting mixture passage 21 are brought into communication through the control passage 24, and the check valve 25 is forcibly opened using the opening rod 29. A starting device for a carburetor which is opened to the outside and keeps a starting fuel pump chamber 14 and a control passage section 24 in communication via a fuel passage section 26. 3. A fuel control jet 15 is provided inside, a starting fuel inflow path 16 is connected to a constant liquid level below the float chamber body 7, and a discharge side check valve 1 is provided inside.
7, a starting fuel discharge passage 18 connected to the engine-side intake passage 2 through the throttle valve 9, and an open starting fuel pump chamber 14; a starting air passage 20 having one end connected to the atmosphere;
and a starting mixture passage 21 whose one end is connected to the intake passage 2 on the engine side from the throttle valve 9; 23 and starting air passage 20
and a control passage section 24 that controls communication and disconnection between the engine and the starting mixture passage 21, one end of which opens into the starting fuel pump chamber 14 via a check valve 25, and the other end of which opens into the control passage section 24. a starting control valve 22 comprising: a fuel passage section 26; which applies an operating force to the starting control valve 22 and elastically absorbs the closing force of the check valve 25 disposed in the fuel passage section 26 during the pressing operation; The operating rod 27 is increased by the member; At the end of the pressing movement of the starting fuel pump chamber 14 by the pump part 23 of the starting control valve 22, the check valve 25 is forcibly opened to open the starting fuel pump chamber 1.
4 and the fuel passage section 26 in a communicating state; and an open rod 29 that is arranged in the starting mixture passage 21 and sequentially controls the amount of starting mixture flowing through the starting mixture passage 21 according to the rise in the engine atmosphere temperature. Thermal expansion body 53 decreases
With the operation rod 27, the starting air passage 20 and the starting air mixture passage 21 are connected to the control passage part 24 at the beginning of the pressing movement of the starting control valve 22 against the starting fuel pump chamber 14 by the pump part 23. At the same time, the control passage section 24 and the starting fuel pump chamber 14 are cut off at the check valve 25, and the pump section 23 performs a pressurizing pump action on the starting fuel pump chamber 14. On the other hand, at the end of the pressing movement of the starting fuel pump chamber 14 by the pump section 23 of the starting control valve 22, the operating rod 27 closes the starting air passage 20.
The starting fuel pump chamber 14 and the control passage 24 are brought into communication with each other through the control passage 24, and the check valve 25 is forcibly opened using the opening rod 29. Fuel passage section 26
A starting device for a carburetor that is maintained in communication via a.