JPS59108854A - Carburetor controlling apparatus - Google Patents

Abstract

PURPOSE:To permit the temperature of the engine cooling water to be raised slowly even if rising-up of the engine cooling water temperature is rapid, by simply coating the outer peripheral surface of a wax valve with synthetic resin film, in an apparatus for controlling a carburetor on the basis of the variation of the temperature of the engine cooling water. CONSTITUTION:A wax valve 34 is inserted into a large-diameter hole 32 on a carburetor controller 30, and a push rod 35 operated by the wax valve 34 is inserted into a small-diameter hole 33. The outer peripheral surface of a flange part 34a positioned on a temperature sensing part 34b side with respect to an O- ring 45 and the all outer peripheral surface of the temperature sensing part 34b are covered with a film 46 made of synthetic resin material. Cooling water is introduced from a cooling-water feeding pipe 49a through the film 46 for heating the wax valve 34. The temperature of the temperature sensing part 34b slowly rises in comparison with the temperature of the engine cooling water, and the push rod 35 is shifted leftward to gradually reduce the amount of fuel supplied from a nozzle 23.

Description

[Detailed description of the invention] The present invention relates to a carburetor control device for an internal combustion engine.

In conventional internal combustion engines, the engine cooling water temperature increases as the engine warms up, so engine warm-up control is often performed based on changes in the engine cooling water temperature. A carburetor control device is known in which a fast idle cam is actuated by a wax valve. In this way, engine cooling water is often used for engine warm-up control because it is easier to handle than using electrical means or engine lubricating oil, and it also simplifies the structure of the warm-up control device. This is because it can be done. However, in recent years, engines have become lighter, and engine structures have been designed to reduce the amount of engine cooling water as much as possible, so the engine cooling water temperature rises much faster during warm-up compared to before, and therefore the engine The increase in engine cooling water temperature is no longer able to cope with the progress of warm-up. As a result, as mentioned above, for example, if the fast idle cam is activated depending on the engine cooling water temperature, the fast idle cam will be released before the first engine has warmed up sufficiently, causing the engine speed to drop and the engine to slow down. This causes the problem that it stops.

The present invention makes it possible to perform engine warm-up control based on engine cooling water temperature in accordance with the progress of engine warm-up even when the engine cooling water temperature rises quickly during warm-up operation. An object of the present invention is to provide a vaporizer control device that achieves the following.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, 1 is a carburetor main body, 2 is an intake passage extending vertically, 3 is a suction piston that moves laterally within the intake passage 2, and 4 is a needle attached to the tip surface of the suction piston 3. , 5 is suction piston 3
6 is a throttle valve provided in the intake passage 2 downstream of the suction piston, and 7 is a carburetor float chamber. A venturi portion 8 is formed between the front end surface of the spacer 5 and the spacer 5 . A hollow cylindrical casing 9 is fixed to the carburetor body 1, and a guide sleeve 10 extending in the axial direction of the casing 9 inside the casing 9 is attached. A bearing 12 with a number of poles 11 is inserted into the guide sleeve IO, and the outer end of the guide sleeve 10 is closed by a blind cover 13. On the other hand, a guide rod 14 is fixed to the suction piston 3, and the guide rod 14 is inserted into the bearing 12 so as to be movable in the axial direction of the guide rod 14. Since the suction piston 3 is thus supported by the casing 9 via the bearing 12, the suction piston 3 can move smoothly in its axial direction. The inside of the casing 9 is provided with a negative pressure chamber 1 by the suction piston 3.
5 and an atmospheric pressure chamber 16, and a compression spring 17 is inserted into the negative pressure chamber 15 to constantly press the suction piston 3 toward the pentier section 8. The negative pressure chamber 15 is connected to the air vent 8 through a suction hole 18 formed in the suction piston 3, and the atmospheric pressure chamber 16 is connected to the air hole 19 upstream of the suction piston 3 through an air hole 19 formed in the carburetor body 1. It is connected within the intake passage 2.

On the other hand, a fuel passage 20 extending in the axial direction of the needle 4 is formed in the carburetor main body l so that the needle 4 can enter therein, and a metering jet 21 is provided within this fuel passage 20. The fuel passage 20 upstream of the metering jet 21 is connected to the float chamber 7 via a fuel pipe f22 extending downward, and the fuel in the float chamber 7 is sent into the fuel passage 20 via this fuel pipe f22. It will be done. Furthermore, a hollow cylindrical nozzle 23 coaxially arranged with the fuel passage 20 is fixed to the spacer 5 . This nozzle 23 protrudes from the inner wall surface of the spacer 5 into the pentier portion 8, and the nozzle 23
The upper half of the tip further protrudes from the lower half toward the suction piston 3.

The needle 4 extends through the nozzle 23 as well as the metering jet 21, and the fuel is metered into the nozzle 23 through the annular gap formed between the needle 4 and the metering jet 21.
The air is supplied into the intake passage 2 from the air.

As shown in FIG. 1, an annular air passage 24 is formed around the metering jet 12, and a plurality of air bleed holes 25 are formed in the metering jet 21 to communicate the annular air passage 24 with the inside of the metering jet 21. Formed on the inner peripheral wall surface. The annular air passage 24 is connected to an air bleed passage 26 formed within the carburetor body l. Also, weighing Geno) 2
An auxiliary air bleed hole 27 is formed in the earth wall surface of the fuel passage 20 one downstream, and this auxiliary air bleed hole 27 is connected to the air bleed passage 26 .

As shown in FIG. 1, an intake passage 2 is provided at the upper end of the spacer 5.
A raised wall 29 is formed that projects inward in the horizontal direction,
Flow rate control is applied between this raised wall 29 and the tip of the suction piston 3. When engine operation is started, air flows downward within the intake passage 2. At this time, the airflow is restricted between the suction piston 3 and the protrusion 29, so that negative pressure is generated in the penetrating portion 8, and this negative pressure is led into the negative pressure chamber 15 through the suction hole 18. The suction piston 3 is arranged so that the pressure difference between the negative pressure chamber 15 and the atmospheric pressure chamber 16 becomes an almost constant pressure determined by the spring force of the compression spring 17, that is, the negative pressure inside the pliers part 8 becomes almost constant. Move to.

On the other hand, a carburetor control device 30 is attached to the carburetor main body 1. A large diameter hole 32 and a small diameter hole 33 are formed in the housing 31 of this vaporizer control device 30 and communicate with each other, and a wax valve 34 is operated in the large diameter hole 32 and a wax valve 34 is operated in the small diameter hole 33. Pushed bush rod 35
is inserted. The bushing rod 35 has a pair of bulges 36 , 37 arranged at a distance from each other, and an internal chamber 38 formed between the bulges 36 , 37 is formed in the housing 31 of the carburetor control device 30 . The raised wall 29 is connected to the intake passage 2 upstream of the raised wall 29 through an air bleed hole 39 and an air bleed hole 4o formed in the carburetor main body 1. The inner end 37a of the enlarged portion 37 is formed into a conical shape, and an air bleed hole 41 whose opening area is controlled by the conical inner end 37& is formed in the housing 31 of the carburetor control device 1i30. . An air bleed jet 42 is inserted into this air bleed hole 41,
Furthermore, this air bleed hole 41 is connected to an air bleed passage 26 formed within the carburetor body 1. The outer end of the ampulla 37 protrudes outward from the housing 31, and the ampulla 37
A disk-shaped head 43 is integrally formed at the tip. Further, the protruding outer end of the enlarged portion 37 is surrounded by a sealing member 44 fixed to the housing 31.

On the other hand, the wax valve 34 fitted into the large-diameter hole 32 of the vaporizer control device 30 has a flange portion 3 formed in the center thereof.
4m, and a temperature sensing portion 34b having an outer diameter smaller than the flange portion 34a, and the flange portion 34a has an outer diameter smaller than the inner diameter of the large diameter hole 32. An annular groove 34c extending over the outer periphery is formed on the outer peripheral surface of the flange portion 34a, and a QIJ ring 4 is inserted into the annular groove 34c.
5 is fitted. As shown in FIG. 1, in this embodiment, the outer peripheral surface of the flange portion 34a located on the temperature sensing portion 34b side with respect to the O-ring 45 and the entire outer peripheral surface of the temperature sensing portion 34b are coated with a coating 46 made of a synthetic resin material. covered by. On the other hand, inside the large diameter hole 32! A lug 47 is screwed on and the wax valve 34 is held fixed in place by this plug 47. The temperature sensing part 34b covered by the outer cover 46 and the plug 4
An engine cooling water introduction chamber 48 is formed between 7 and 7, and a cooling water supply pipe 49a is connected to this cooling water introduction chamber 48. The cooling water supplied into the cooling water introduction chamber 48 through the cooling water supply pipe 49a heats the wax valve 34 through the coating 46, and then is discharged from the cooling water discharge hole 49b (FIG. 2).

On the other hand, referring to FIGS. 2 to 5, the housing 31
Does it act as a pidet? A seat 50 is screwed on, and a cam 51 and a hinge lever 52 are rotatably attached to this 3j bolt 50. The leno-52 has an L-shaped part 52b spaced 7'c from its middle part 52m, and these parts are connected to each other by the middle part 52a, the L-shaped part 52b, and the ViU-shaped part 52c. A bin 53 is fixed to the intermediate part 52a and the L-shaped part 52b and extends through them, and a roller 54 is rotatably mounted on the bin 53. A tension spring 56 is tensioned between the tip 52d of the lever 52 and the bottle 55 fixed to the housing 32, and the spring force of the tension spring 56 causes the row 254 to constantly move against the f' isk-shaped head of the rod 35. 43. On the other hand, an arm portion 52e is integrally formed at the tip of the L-shaped portion 52b of the lever 52, and an arm portion 51m facing the arm portion 52e is also integrally formed at the end of the cam 51. An adjustment screw 57 is inserted into a hole (not shown) formed in the arm 51a of the cam 51, and the tip of the adjustment screw 57 is screwed onto the arm 52e of the lever 52.

Therefore, by turning this adjustment screw 57, the lever 5
2 and the relative position of the cam 51 can be adjusted. Note that a compression spring 58 for preventing the adjustment screw 57 from loosening is inserted between the arm portion 51m and the arm portion 52e. The rotational force of the lever 52 is transmitted to the cam 51 via the adjustment screw 57, and when the lever 52 is rotated clockwise in FIG. 2, the cam 51 is also rotated clockwise.

On the other hand, as shown in FIG. 2, the valve shaft 6 of the throttle valve 6
A lever 61 is fixed to the lever 61, and a pin 63 that can be engaged with the cam surface 62 of the cam 51 is fixed to the tip of the lever 61. As can be seen from FIG. 2, the radius r of the cam surface 62 measured from the pole 50 gradually decreases in the counterclockwise direction.

FIG. 2 shows a state where the engine temperature is low, and at this time the throttle valve 6 is held open by the action of the cam 51. When the engine is started and the engine cooling water temperature rises, the bushing rod 3 is heated by the action of the wax valve 34.
5 moves to the left in FIG. As a result, since the lever 52 is rotated counterclockwise, the cam 51 is also rotated counterclockwise, and thus the throttle valve 6
will be gradually closed. As mentioned above, the disc-shaped head 43 of the bushing rod 35 and the lever 52
Since a row 254 is provided between them, when the bushing rod 35 moves to the left in FIG. 2, the lever 52 rotates smoothly. Then, when the engine warms up, cam 5
1 and the lever 52 are released, and the throttle valve 6 is thus closed to the idling opening degree. On the other hand, when the engine is started, the engine cooling water temperature rises,
This causes the bushing rod 35 to move to the second position as described above.
When moving to the left in the figure, the amount of air supplied into the internal chamber 38 through the air bleed hole 40 and the air bleed hole 41 increases, and thus the air bleed passage is supplied from the internal chamber 38 through the air bleed hole 39. The amount of air supplied into 26 increases. Therefore, since the amount of air supplied into the fuel passage 20 from the air bleed holes 25, 27 increases, the amount of fuel supplied from the nozzle 23 gradually decreases, and thus the air-fuel mixture supplied into the engine cylinder gradually decreases. becomes thinner.

As shown in FIG. 1, the temperature sensing portion 34b of the wax valve 34
is heated by engine cooling water through the coating 46. Therefore, the temperature of the temperature sensing portion 34b rises more slowly than the engine cooling water temperature. Furthermore, as can be seen from FIG. 1, since there is a gap between the outer peripheral surface of the flange portion 34a of the wax valve 34 and the inner peripheral surface of the large diameter hole 32, heat is transferred from the housing 31 to the wax valve 34. It's getting harder to do. Therefore, even if the engine cooling water temperature rises quickly, the temperature sensing portion 34b
temperature rises slowly to 35 days
moves to the left more slowly than the rise in engine cooling water temperature. As a result, as the engine warms up, the soot valve 6 is gradually closed and the amount of fuel supplied from the nozzle 23 is gradually reduced.

Another embodiment is shown in FIG. In this embodiment, substantially the entire outer peripheral surface of the wax valve 34 is covered with the coating 46. In yet another embodiment shown in FIG. 7, a cup-shaped wax valve holder 20 is fitted into the large diameter hole 32 so as to surround the temperature sensing portion 34b of the wax valve 34. This wax valve holder 2o has a thick part 71 at one end.
An O-ring 73 is placed in an annular groove 72 formed on the outer peripheral surface of 1.
is inserted.

In each of the embodiments shown in FIGS. 1, 6, and 7, the coating 46 can be formed by simply immersing the wax valve 34 in molten synthetic resin.
can be formed very easily. Furthermore, the operational response of the wax valve 34 to a rise in engine cooling water temperature can be made faster or slower simply by changing the thickness of the coating 46. Therefore, by simply changing the thickness of the coating 46, the operational response of the wax valve 34 can be optimally set. can do.

As described above, according to the present invention, by simply coating the outer peripheral surface of the wax valve with a synthetic resin film, even if the engine cooling water temperature rises quickly, the engine can be cooled as the engine warms up. Since the water temperature can be raised slowly, stable warm-up operation can be ensured.

[Brief explanation of drawings]

Fig. 1 is an overall view of the carburetor according to the present invention, Fig. 2 is an overall view of the vaporizer control device, Fig. 3 is a plan view taken along arrow 1■ in Fig. 2, and Fig. 4 is Fig. 3. FIG. 5 is a sectional view taken along the line ■--■ in FIG. 3, FIG. 6 is a side sectional view of another embodiment of the carburetor control device, and FIG.
The figure is a side sectional view of yet another embodiment of the carburetor control device. 30... Carburizer control device, 32... Large diameter hole, 33...
...Small diameter hole, 34...Wax valve, 34b...Temperature sensing part, 46...Coating, 48...Cooling water introduction chamber.

Claims (1)

[Claims] In a carburetor control device that controls a carburetor by a wax valve that responds to engine cooling water temperature, the wax valve is fitted into a hole formed in a housing of the carburetor control device, and at least one of the wax valves is A carburetor control device in which the outer circumferential surface of the temperature sensing portion is covered with a synthetic resin coating, and engine cooling water is guided into the hole in the circumference of the synthetic resin coating.