JPH085326Y2 - Vaporizer heating device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a carburetor heating device for improving startability of an engine.

[Conventional technology]

In the case of a carburetor mounted on an engine of an automobile, a motorcycle, an automobile, a three-wheeled vehicle, or the like, when the fuel vaporizes, the latent heat of vaporization is deprived from the surroundings, and the outside air temperature is low. (For example, 2 ° C. to 5 ° C. or less), the inside of the intake passage may be too cold, and it may take time to start the engine.

Therefore, in order to improve engine startability in cold weather,
A method of heating the entire carburetor by guiding the heated air flow to the carburetor surface when passing through the surface of the radiator or engine (JP-A-62-26354), vaporizing the cooling water (hot water) from the radiator Method of introducing into the vessel and heating, or
A method of mounting a heating wire heater near the float chamber of the vaporizer (Japanese Patent Laid-Open No. 62-26352) has been proposed.

However, the method of introducing hot air or hot water from a radiator or the like is not very effective at the time of engine start when the radiator itself is cooling to near the outside temperature, and moreover, it takes a considerable time to effectively heat the carburetor after the engine starts. I need it.

Also, in the method of directly heating with a heating wire heater, etc.,
-A temperature sensor is required to control OFF, which complicates the device structure and increases the cost.

By the way, in a cooling system of a water-cooled engine, an in-line type thermostat valve is provided on the outlet side of a water jacket formed in a cylinder or a cylinder head, and when the temperature of the cooling water falls below a certain value, the thermostat valve is opened to cool the cooling water. Is used to circulate the heat to the radiator.

Therefore, as a measure to improve the conventional heating device for the carburetor, a bypass water passage for returning the carburetor from the upstream side of the thermostat valve (outlet side of the water jacket) is provided, and engine cooling water (hot water) flowing through the bypass water passage is provided. It is conceivable to adopt the method of loosening the carburetor.

In this method, it is preferable to adopt a structure in which hot water (engine cooling water) is circulated by providing a water passage of, for example, a diameter of about 2 mm through a desired portion of the carburetor main body (for example, near a place such as a bypass port where temperature tends to be low) .

[Technical issues to be solved by the invention]

By the way, when constructing the heating device of this type of carburetor, it is common to connect the bypass water passage on the side returning from the carburetor to the downstream side of the thermostat valve.

On the other hand, a water pump for circulating the cooling water is provided at the inlet side of the water jacket of the engine and is configured to suck the cooling water cooled by the radiator and pump the cooling water into the water jacket. There is.

However, in the general arrangement of the bypass water channel as described above, since the pump suction force acts through the radiator with a large pressure loss, due to the pressure loss of the radiator, sufficient warm water is passed through the bypass water channel during cold weather. In some cases, the carburetor cannot be warmed early and the startability in cold weather may be insufficiently improved.

As a countermeasure, increasing the inner diameter of the bypass canal may be considered, but this is disadvantageous in layout.

Further, in the conventional vaporizer heating device, even if the bypass channel is closed when the outside air is at a high temperature, heat transfer due to convection or conduction of cooling water in the bypass channel upstream of the vaporizer is completely blocked. Therefore, it is not possible to reliably prevent the heat of the cooling water from being transferred to the vaporizer, which may cause percolation.

[Means for solving problems]

The present invention has been made in view of the above prior art,
According to the present invention, the engine has a suction port for sucking the cooling water circulated from the engine water jacket through the thermostat valve and the radiator, and a discharge port for pumping the sucked cooling water to the water jacket. In a warming device for a carburetor of an engine equipped with a water pump, for introducing a cooling water flow passage formed near a fuel supply port of the carburetor and cooling water from the water jacket into the passage of the carburetor. A forward bypass water channel, a return bypass water channel for returning cooling water from the passage of the carburetor to the suction port of the pump, a water channel, and two nip portions and a suction connection of the water pump. And a joint member having an outlet part that is provided, and the cooling water temperature is provided in the middle of the forward bypass water channel. A temperature-sensing on-off valve that automatically closes and stops the bypass flow of cooling water when the temperature exceeds a preset temperature near the closing temperature of the thermostat valve, and the radiator is provided at one nip portion of the joint member. By connecting the cooling water channel for introducing the circulated cooling water and connecting the outlet side of the return bypass water channel to the other nipple part of the joint member, the pressure difference between the inlet and outlet of the bypass water channel is maximized. By ensuring a sufficient amount of circulation of the cooling water for heating that is made as large as possible and circulates in the passage of the carburetor, it is possible to warm the carburetor early even in cold weather and improve startability. When the temperature is high, the heat transfer to the carburetor due to convection and conduction of the cooling water on the upstream side of the carburetor is cut off, and the bypass water passage is cut off and cut off against the temperature of the cooling water. Can be controlled with an accuracy, warming device of the carburetor that can reliably prevent percolation generation is obtained Toto to improve the heating efficiency of the vaporizer.

〔Example〕

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

FIG. 1 shows the overall structure of a carburetor heating device according to the present invention.

In FIG. 1, an engine 1 connects a crankshaft 3 axially supported in a crankcase 2 and a piston 5 fitted in a cylinder 4 with a connecting rod 6, and a top surface of the piston 5 and a cylinder head 7 are connected to each other. The combustion chamber 8 is formed between them.

The illustrated engine 1 is a water-cooled engine, and a cylinder 2
A water jacket 9 is formed in the cylinder head 7 at a position surrounding the combustion chamber 8.

Cooling water is fed to the water jacket 9 from a lower part by a water pump 10 driven by the engine 1,
After flowing upward, it is sent out from the upper surface of the cylinder head 7.

Two outlet holes 11 and 12 communicating with the water jacket 9 are formed on the upper surface of the cylinder head 7, and one of the outlet holes 11 is provided with a hose 14 for guiding cooling water coming out of the water jacket 9 toward a radiator 13. It is connected.

The water passage from the outlet hole 11 to the radiator 13 is composed of two hoses 14 and 15, and a thermostat valve is provided between them.
16 are connected.

The thermostat valve 16 is in a closed position when the cooling water temperature is below a set value (for example, 70 ° C.), and is in an open position when the cooling water temperature exceeds the set value to circulate the cooling water (warm water) to the radiator 13. .

The cooling water flowing through the radiator 13 and cooled is sucked by the water pump 10 through the hose 17 on the return side, and the engine 1 is restarted.
It is sent into the water jacket 9 of.

The engine 1 has an air cleaner 18 and a carburetor.
19 is connected through the intake passages 20 and 21, and the air-fuel mixture created by the vaporizer is supplied into the combustion chamber 8.

Another outlet hole 12 formed on the upper surface of the cylinder head 7 is a bypass water passage (hose) for circulating the cooling water coming out of the water jacket 9 to the vaporizer 19.
22 is connected, and the cooling water branched from the bypass water passage 22 flows through a water passage (passage) 23 formed in the carburetor 19, and then the return bypass water passage (hose) 24 is passed through to the water pump 10 Returned to the entrance (suction port).

In this way, the engine cooling water coming out of the water jacket 9 is passed through the bypass water channels 22, 23 and 24 to the carburetor 19
A warming device for a carburetor that is circulated to a carburetor, which has a configuration in which a bypass water passage 24 on the return side from the carburetor 19 is connected to a suction port (inlet) of the water pump 10.

 FIG. 2 is a sectional view showing a main part of the vaporizer 19.

In FIG. 2, an intake passage 26 for introducing air from the air cleaner 18 (FIG. 1) into the engine 1 (combustion chamber 8).
A slide piston 27 is slidably attached across the slide piston 27, and a jet needle 28 attached to the slide piston 27 adjusts the opening degree of a main nozzle 30 leading to a float chamber (fuel reservoir) 29.

When the engine speed is high and the intake negative pressure is strong, the slide piston 27 is pulled upward in FIG. 2, the opening of the main nozzle 30 is increased, and the fuel supply amount is increased.

A butterfly valve type throttle valve 31 is provided downstream of the slide piston 27 in the intake passage 26.

The throttle valve 31 is normally opened and closed by a driver's throttle operation via a wire (not shown).

A bypass port 32 for supplying fuel during idling and low speed operation is formed at a position slightly downstream of the closed position of the throttle valve 31, and the bypass port 32 is provided with a bypass jet 33 and a fuel passage 34 through which a float chamber is inserted. I am familiar with 29.

In the vicinity of the bypass port 32 of the carburetor 19, a passage (water passage) 23 forming a part of the bypass water passages 22, 23, 24 (FIG. 1) is formed.

The passage 23 is formed of a hole having a diameter of about 2 mm, for example.

The passage 23 is formed through the carburetor main body (aluminum die casting) at a portion such as the vicinity of the bypass port 32 where the latent heat of vaporization is easily deprived to lower the temperature or in the vicinity thereof. Bypass channels 22 and 24
(Fig. 1) are connected.

FIG. 3 is a longitudinal sectional view showing details of the thermostat valve 16 in FIG.

In FIG. 3, the thermostat valve 16 has an opening / closing valve mechanism housed in cases 35 and 36 forming a part of a water channel, and an inlet nipple for connecting the hoses 14 and 15 to the cases 35 and 36, respectively. The structure has a portion 37 and an outlet nipple portion 38.

The thermostat valve 16 is of a wax type, and includes a container 39 in which wax is enclosed, a piston 40 whose protrusion length changes from the container 39 due to a change in volume of the wax, and a valve member 41 fixed to the container 39. The movable portion composed of (1) is elastically held by a spring (45) against a fixed frame part composed of a valve seat member (42), a piston stop (43) and a spring receiver (44).

FIG. 4 is a longitudinal sectional view showing the water pump 10 in FIG. 1 and its related parts.

In FIG. 4, the water pump 10 has an impeller 52 axially supported in a pump casing 51 fixed to the side surface of the crankcase 2, and a pump drive shaft 53 which is axially supported in the crankcase 2 and rotates with engine rotation. By rotating the impeller 52 at
The cooling water is sucked from 54 and the cooling water is discharged from a discharge port 55 formed in the radial direction of the casing 51.

A joint member 58 forming a water channel is connected to the suction port 54 of the casing 51. The joint member is provided with two nipples 56 and 67 and an outlet which is hermetically connected to the suction port 54 of the water pump 10.

Return hose from radiator 13 to one nipple 56
17 (FIG. 1) is connected, and the other side nipple 57 is connected to the bypass water passage 24 (FIG. 1) on the return side from the carburetor 19.

A discharge port 55 of the casing 51 is connected to a lower end inlet 60 of the water jacket 9 (usually provided on the recinder 4) via a hose 59, and cooling water discharged from the water pump 10 is supplied to the engine 1. It is sent into the water jacket 9.

Returning to FIG. 1, a bypass water passage 22 for circulating the cooling water coming out of the water jacket 9 to the carburetor 19, that is, a bypass water passage connecting the water jacket outlet hole 12 of the cylinder head 7 and the passage 23 inlet of the carburetor 19. (Hose) 22
A temperature detection type on-off valve 61 that automatically closes and stops the bypass flow when the cooling water temperature becomes equal to or higher than a set temperature (for example, 70 ° C.) is provided in the middle of.

The on-off valve 61 may be, for example, a thermostat valve 16
An on-off valve similar to the above or a check valve using a shape memory alloy can be used.

When the engine 1 is started, the water pump 10
Is driven and the engine cooling system is activated.

When the temperature of the cooling water is lower than the set temperature (for example, 70 ° C.) immediately after the start-up, the thermostat valve 16 is in the closed position shown by the solid line in FIG. 3, and the cooling water is not circulated to the radiator 13 and is cooled by the engine 1. Used for cooling, vaporizer 19
Since the temperature detection type on-off valve (check valve) 61 provided in the bypass water passage 22 to the is open below the set temperature (for example, 70 ° C.), the cooling water (hot water) is circulated to the carburetor 19, By heating the carburetor 19, engine startability can be improved and smooth start-up and operation can be maintained even in cold weather.

When the temperature of the cooling water rises and exceeds the set value, the thermostat valve 16 opens as shown by the chain double-dashed line in FIG. 3, and the cooling water that has become high temperature flows to the radiator 13 to lower the temperature and the water jacket. It is sent into the inside 9 and the heating of the engine 1 is prevented (water cooling).

When the temperature of the cooling water rises and the startability can be ensured even in cold weather, the opening / closing valve 61 of the bypass water passage 22 is closed, and the circulation of the cooling water (hot water) to the carburetor 19 is blocked.

This prevents percolation that may occur when circulating hot cooling water into the vaporizer 19.

The temperature detection type on-off valve 61 also has a function of preventing the heat of the high-temperature cooling water whose temperature is further increased in the engine 1 from being transmitted to the carburetor 19 when the temperature of the atmosphere is high.

That is, in the above-described embodiment, since the temperature detection type on-off valve 61 is provided at the position on the upstream side of the carburetor 19 in the bypass water passage, if the on-off valve 61 is closed when the outside air is at high temperature, the temperature of the engine 1 is further increased. It is possible to prevent the heat of the high-temperature cooling water on the upstream side of the vaporizer 19 that has been raised from being transferred to the vaporizer 19 by convection or conduction, and it is possible to further prevent the occurrence of percolation.

Further, the relationship between the opening / closing operation of the opening / closing valve 61 and the cooling water temperature can be easily controlled with high accuracy, and the vaporizer can be efficiently heated.

Further, according to the embodiment described above, in constructing the heating device of the carburetor that circulates the engine cooling water coming out of the water jacket 9 of the engine 1 to the carburetor 19 through the bypass channels 22, 23, 24, Since the bypass water passage 24 on the return side from the carburetor 19 is directly connected to the suction port 54 of the water pump 10 through the joint member 58, the negative suction force in the suction port 54 at which the pump suction force is the strongest is generated. It becomes possible to circulate the cooling water by utilizing the.

Therefore, it becomes possible to efficiently heat the vaporizer 19 by securing a sufficient amount of circulating water to be circulated from the water jacket 9 to the vaporizer 19.

That is, the water passage (passage) 23 in the carburetor 19 has an extremely small diameter and is often long for the diameter, so that the flow resistance in the passage 23 becomes large, and therefore,
In order to secure the amount of circulating water required to heat the vaporizer 19, it is necessary to set the pressure difference between the inlet and the outlet of the bypass channels 22, 23, 24 sufficiently large.

Therefore, in the above-described embodiment, the inlets of the bypass channels 22, 23, 24 are connected to the outlet holes 12 of the water jacket 9, and the outlets of the bypass channels are subjected to the strongest negative pressure suction force as described above. Since it directly communicates with the suction port 54 of 10, the pressure difference between the inlet and the outlet can be made sufficiently large. Therefore, by ensuring a sufficient amount of circulating water from the water jacket 9, it is possible to avoid Also, it becomes possible to warm the carburetor 19 early and improve the startability.

[Effect of device]

As is clear from the above description, according to the present invention, the suction port for sucking the cooling water circulated from the water jacket of the engine through the thermostat valve and the radiator and the discharge port for pumping the sucked cooling water to the water jacket are provided. In the warming device of the carburetor of the engine, which has a water pump driven by the engine,
A passage for circulating cooling water formed near the fuel supply port of the carburetor, a forward bypass passage for introducing cooling water from the water jacket into the passage of the carburetor, and cooling water from the passage of the carburetor. A return bypass water channel for returning the water to the suction port of the water pump, a joint member that constitutes the water channel and has two nip portions and an outlet portion that is hermetically connected to the suction port of the water pump,
A temperature detection type on-off valve which is provided in the middle of the forward bypass water passage and automatically closes and stops the bypass flow of the cooling water when the cooling water temperature becomes equal to or higher than a preset temperature near the closing temperature of the thermostat valve, And a cooling water passage for introducing cooling water circulated through the radiator to one of the nip portions of the joint member, and the outlet side of the return bypass water passage to the other nip portion of the joint member. Therefore, by maximizing the pressure difference between the inlet and outlet of the bypass water channel and securing a sufficient circulation amount of the cooling water for heating to flow through the carburetor passage, the carburetor can be warmed early even in cold weather. The startability can be improved, and when the temperature of the atmosphere is high, the heat transfer to the vaporizer due to the convection and conduction of the cooling water on the upstream side of the vaporizer is blocked, and the percolation is performed. Warming apparatus of carburetor can be further prevented raw is provided.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an overall configuration of a vaporizer heating device according to the present invention, and FIG. 2 is a vertical sectional view of the vaporizer in FIG.
FIG. 3 is a vertical sectional view of the thermostat valve in FIG.
The drawing is a vertical cross-sectional view of the water pump and related parts in FIG. 1 ... Engine, 4 ... Cylinder, 7 ... Cylinder head, 9 ... Water jacket, 10 ... Water pump, 13 ...
… Radiator, 16 …… thermostat valve, 19 …… carburetor, 22,23,24 …… bypass channel, 54 …… suction port,
55 …… Discharge port, 56,57 …… Nipple part, 58 …… Joint member, 61 …… Temperature detection type on-off valve.

Claims (1)

[Scope of utility model registration request] 1. A suction port (54) for sucking cooling water circulated from a water jacket (9) of an engine (1) through a thermostat valve (16) and a radiator (13) and the sucked cooling water. In a warming device for an engine carburetor having a water pump (10) driven by an engine, the heating device for the carburetor (19) having a discharge port (55) for pressure-feeding to the carburetor (19) is provided near the fuel supply port. A passage (23) for circulating cooling water to be formed; a forward bypass water passage (22) for introducing cooling water from the water jacket (9) into the passage (23) of the carburetor (19); A return bypass water channel (24) for returning the cooling water from the passage (23) of (19) to the suction port (54) of the water pump (10), and two nipple portions (56, 56) forming a water channel. 57) and the water A joint member (58) having an outlet that is hermetically connected to the suction port (54) of the pump (10), and provided in the middle of the forward bypass water passage (22), and the cooling water temperature is the thermostat valve (16). A temperature detection type opening / closing valve (61) that automatically closes and stops the bypass flow of the cooling water when the temperature exceeds a set temperature near the closing temperature of the joint member (58). A cooling water passage (17) for introducing the cooling water circulated through the radiator (13) is connected to 56), and the joint member (58)
To the other bypass nipple (57) of the return bypass channel (2
4) A vaporizer heating device characterized by connecting the outlet side.