JPH0765544B2 - Cooling structure of fuel supply device - Google Patents

Description

The present invention relates to a cooling structure for a fuel supply device having a fuel storage tank in the vicinity of an intake passage of an engine, and more particularly to a fuel structure inside the storage tank. It relates to a cooling structure.

<Prior Art> For example, in an automobile engine in which a carburetor is used as a fuel supply device, the carburetor and its internal float chamber and fuel passage are accompanied by a temperature rise of the engine body for a while after the engine is stopped after operation. The fuel temperature rises and air bubbles are generated, so that the hot restartability tends to deteriorate, and idling after restart tends to become unstable. If the vaporizer is heated more than necessary, the material forming the vaporizer deteriorates. Therefore, as disclosed in Japanese Utility Model Laid-Open No. 54-180840, conventionally, the periphery of the float chamber and the fuel passage is covered with a heat insulating material, or the engine cooling fan is driven for a while after being stopped. The technology was used to cool the inside of the engine room and prevent the temperature of the carburetor and its internal fuel from rising. Further, a technique has also been adopted in which a vapor separator is attached to a vaporizer to separate bubbles generated inside from the fuel to prevent vapor lock.

However, since each of the above techniques does not directly and positively cool the vaporizer and its internal fuel, it is difficult to maintain the vaporizer and its internal fuel at a desired temperature with a single technique. Therefore, actually, a plurality of the above techniques are used together. Therefore, there is a problem that the structure becomes complicated, the vaporizer becomes large, and the manufacturing cost tends to increase.

<Problems to be Solved by the Invention> In view of the problems of the prior art as described above, a main object of the present invention is to provide a fuel supply device including a fuel storage tank in the vicinity of an intake passage of an engine and a simple internal fuel thereof. Another object of the present invention is to provide a cooling structure for a fuel supply device that can maintain a desired temperature with a different structure.

[Configuration of the Invention] <Means for Solving the Problems> According to the present invention, such a purpose is to provide a cooling structure for a fuel supply device having a carburetor or a fuel injection device having a fuel storage tank near the engine. A water jacket provided around the storage tank and having an air hole in the upper portion, and a water reservoir for cooling water provided at a position where the inner water surface is lower than the lower end portion of the water jacket. , Both ends are opened at a lower end in the water tank and an upper end in the water jacket, a cooling water supply passage for supplying cooling water from the water tank to the water jacket, and both ends in the water jacket. A cooling water return passage that opens at the lower end and the upper end of the water storage tank and returns cooling water from the water jacket to the water storage tank, and is installed in either one of the both passages. And a pump that selectively circulates cooling water in accordance with the fuel temperature in the storage tank, a void is secured in the upper portion of the water jacket during cooling water circulation by the pump, and cooling water circulation This is achieved by providing a cooling structure for a fuel supply device, which is capable of returning most of the cooling water in the water jacket to the water tank when stopped.

<Operation> In this way, the cooling water is selectively circulated between the water jacket and the water tank according to the fuel temperature inside the carburetor or the throttle body, so that the internal fuel of the carburetor or the throttle body is Can be cooled with a high cooling capacity, and when it is cold, cooling water can be removed from the water jacket and the inside can be filled with air to prevent overcooling, so the fuel inside the carburetor and throttle body can always be maintained at the desired temperature. can do.

<Embodiment> Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view schematically showing a vaporizer 1 having a cooling structure according to the present invention. Inside the vaporizer 1
The intake passage 2 extending in the vertical direction in the drawing communicates with the atmosphere via an air cleaner (not shown) on the upper side thereof,
The lower side communicates with the combustion chamber of the engine via an intake valve. Further, a choke valve 3 made up of a butterfly valve is provided at an upstream side portion of the intake passage 2, and a throttle valve 4 made up of a butterfly valve is provided at a downstream side portion of the intake passage 2 as well. Further, a venturi portion 5 is formed in the middle of the intake passage 2, and the main nozzle 6 is formed in the venturi portion.
Is projected. The main nozzle 6 is connected to a float chamber 7 serving as a storage tank in which fuel is replenished from a fuel tank (not shown) via a fuel passage and a float valve which is interlocked with the float.

On the other hand, the cooling structure according to the present invention includes a water jacket 8 which is formed around the float chamber 7 of the carburetor 1 and has an air hole 8a at the upper end, a water tank 9, and a water jacket 8. A cooling water return passage 10 opening at the lower end and the upper end of the water tank 9, and a cooling water supply passage 11 opening near the lower end of the water tank 9 and the upper end of the water jacket 8.
And a pump 12 provided in the middle of the cooling water supply passage 11 and selectively supplying cooling water from the water tank 9 to the water jacket 8 via the passage. Here, the water tank 9 is a relatively cold place, and the water level of the cooling water stored therein is lower than the lower end portion of the water jacket 8 as shown by the imaginary line in FIG. It is arranged in a position.

The pump 12 is connected to a power supply 14 via a relay 13.
This relay 13 is a temperature switch 15 that turns on when the engine coolant temperature rises instead of the fuel temperature in the float chamber.
The pump 12 is selectively driven in conjunction with.

Next, the operating procedure of this embodiment will be described.

First, when the carburetor 1 is at a low temperature, that is, when the engine cooling water temperature is low, the temperature switch 15 is off, so the relay 13 is also off, and the pump 12 is stopped. At this time, since the water jacket 8 does not have cooling water and is filled with air, it functions as a heat insulating material.

When the temperature of the carburetor 1 rises and the fuel temperature in the float chamber 7 rises, that is, when the engine cooling water temperature rises, the temperature switch 15 turns on, the relay 13 turns on, and power is supplied to the pump 12. The pump operates.
Then, the cooling water is supplied to the water jacket 8 through the supply passage 11, and at the same time, the cooling water returns from the water jacket 8 to the water tank 12 through the return passage 10, so that the cooling water is supplied to the water tank 9 and the water jacket 8. And the vicinity of the float chamber 7 are suitably cooled.

Here, by adjusting the diameter of the return passage 10 and the amount of cooling water supplied from the supply passage 11 into the water jacket 8, a gap 8b functioning as an evaporation chamber is secured in the upper portion of the water jacket 8 and the cooling water is secured. The heat of vaporization can be used, and the cooling capacity is further improved.

Then, when the temperature of the carburetor 1 gradually decreases, that is, when the engine cooling water temperature decreases, the temperature switch 15 and the relay 13
Turns off and pump 12 stops. Then, the cooling water is not supplied from the water tank 9 side to the water jacket 8, and all the cooling water returns from the water jacket 8 to the water tank 9 through the return passage 10. Therefore, as described above, the water jacket 8 functions as a heat insulating material, and there is no fear of cooling the carburetor 1 more than necessary.

Needless to say, the present invention is not limited to the above-described embodiment and can be applied in various ways. For example, in this embodiment, the carburetor is cooled, but the vicinity of the injection nozzle of the fuel injection device is cooled. It may be done. Further, in this embodiment, the exclusive cooling water for cooling the carburetor is used, but in practice, for example, the window washer liquid and its tank may be used together. Further, in the present embodiment, a switch for detecting the temperature of the cooling water of the engine is used as the temperature switch, but a switch and a sensor for detecting the temperature of the carburetor or the fuel inside the carburetor can also be used as the switch of the engine cooling fan. Etc. may be provided.

As described above, according to the present invention, it is possible to directly and positively cool a fuel supply device such as a carburetor and a fuel injection device and its internal fuel with a simple structure.
These can be temperature-controlled in a desired range, an air-fuel ratio corresponding to the engine temperature can be obtained, and deterioration of the material forming the carburetor and the slot body due to temperature changes can be prevented. From the above, the effect of the present invention is extremely large.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a vaporizer having a cooling structure according to the present invention. 1 ... Vaporizer, 7 ... Float chamber 8 ... Water jacket 8a ... Air hole, 8b ... Void 9 ... Water tank, 10 ... Return passage 11 ... Supply passage, 12 ... Pump 13 ... Relay, 14 …… Power supply 15 …… Temperature switch

Claims (1)

[Claims] 1. A cooling structure for a fuel supply device having a carburetor or a fuel injection device having a fuel storage tank near an engine, the cooling structure being provided around the storage tank and having an air hole formed in an upper portion thereof. A water jacket, a water tank for cooling water provided at a position where the water surface inside is lower than the lower end of the water jacket, and both ends are opened at the lower end of the water tank and the upper end of the water jacket. A cooling water supply passage for supplying cooling water from the water tank to the water jacket; both ends open at a lower end of the water jacket and an upper end of the water tank, and from the water jacket to the water tank And a cooling water return passage for returning the cooling water to the inside of the storage tank, and the cooling water is circulated selectively depending on the fuel temperature in the storage tank. A pump that allows the cooling water to be circulated in the water jacket even when the cooling water is circulated by the pump, and most of the cooling water in the water jacket can be returned to the water tank when the cooling water circulation is stopped. Characteristic fuel supply device cooling structure.