JPH02207165A - Cooling structure of fuel supply device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] <Industrial Field of Application> The present invention relates to a cooling structure for a fuel supply device having a fuel storage tank near the intake passage of an engine, and particularly relates to a cooling structure for a fuel supply device that is equipped with a fuel storage tank near the intake passage of an engine. Regarding the structure for cooling.

<Prior art> For example, in an automobile engine that uses a carburetor as a fuel supply system, for a while after the engine is stopped, the temperature of the engine body rises and the temperature inside the carburetor, its internal float chamber, and fuel passage increases. As the fuel temperature rises and bubbles are generated, hot restart performance tends to decrease and idling after restart tends to become unstable. Also, if the vaporizer is heated more than necessary, the material forming the vaporizer will deteriorate. Therefore, as disclosed in Japanese Utility Model Application Publication No. 54-180840, conventional methods have been to cover the float chamber and fuel passage with a heat insulating material, or to open the engine cooling fan for a while after stopping. A technology was used to cool the engine room and prevent the temperature of the carburetor and its internal fuel from rising. Additionally, a technology was adopted to prevent vapor lock by attaching a vapor separator to the vaporizer to separate the bubbles generated inside from the fuel.

However, since each of the above-mentioned technologies does not directly actively cool the carburetor or the fuel inside it, it is difficult to maintain the carburetor and the fuel inside it at a desired temperature using a single technology. Therefore, in reality, multiple of the above technologies are used together. Therefore, the structure becomes complicated, the vaporizer becomes large, and the manufacturing cost tends to rise.

<Problems to be Solved by the Invention> In view of the problems of the prior art, the main object of the present invention is to provide a fuel supply system having a fuel storage tank near the intake passage of an engine, and to simplify the internal fuel supply system. An object of the present invention is to provide a cooling structure for a fuel supply device that can maintain a desired temperature with a flexible structure.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, an object of the present invention is to provide a cooling structure for a fuel supply device having a fuel storage tank near an engine, the cooling structure including a water storage tank; A water jacket provided around the storage tank, a passage that supplies cooling water from the water storage tank to the water jacket, a passage that returns cooling water from the water jacket to the water storage tank, and either of the passages. This is achieved by providing a cooling structure for a fuel supply device characterized by having a pump provided on one side and selectively circulating cooling water depending on the fuel temperature in the storage tank. In particular, an air hole is provided in the upper part of the water jacket, the water tank is provided at a position where the water level of the internal cooling water is lower than the lower end of the water jacket, and both ends of the cooling water supply passage are connected to the water tank. openings at the lower end of the water jacket and the upper end of the water jacket;
It is preferable that both ends of the cooling water return passage open to a lower end in the water jacket and an upper end in the water storage tank, and the cooling water is circulated so that a gap is secured in the upper part of the water jacket.

<Operation> In this way, the carburetor or throttle body and its internal fuel can be maintained at a desired temperature by selectively circulating the cooling water according to the fuel temperature inside the carburetor or throttle body. Can be done.

<Embodiments> Hereinafter, preferred embodiments 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 equipped with a cooling structure according to the present invention. Inside this vaporizer 1, a first
The intake passage 2 extending in the vertical direction in the figure communicates with the atmosphere via an air cleaner (not shown) at its upper side.
The lower side communicates with the combustion chamber of the engine via an intake valve. Further, a choke valve 3 made of a butterfly valve is provided on the second-stream side of the intake passage 2, and a throttle valve 4 made of a butterfly valve is similarly provided on the downstream side of the intake passage 2. Further, a venturi portion 5 is formed in the middle portion of the intake passage 2, and a main nozzle 6 is provided protruding from the venturi portion. This main nozzle 6 is connected to a float chamber 7, which serves as a storage tank, and is replenished with fuel from a fuel tank (not shown) via a fuel passage and a float valve linked to a float.

On the other hand, the cooling structure based on the present invention includes a water jacket 8 that is constructed around the float chamber 7 of the vaporizer 1 and has an air hole 8a at the upper end, a water storage tank 9, and a A cooling water return passage 10 that opens at the lower end and the upper end of the water storage tank 9; a cooling water supply passage 11 that opens near the lower end of the water storage tank 9 and the upper end of the water jacket 8; A pump 12 is provided in the intermediate portion and selectively supplies cooling water from the water tank 9 to the water jacket 8 via the passage.

Here, the water storage tank 9 is a relatively cold place, and the water level of the cooling water stored therein is lower than the lower end of the water jacket 8, as shown by the imaginary line in FIG. placed in position.

Pump 12 is connected to power supply 14 via relay 13. This relay 13 is configured to selectively drive the pump 12 in conjunction with a temperature switch 15 that is turned on when the engine cooling water temperature rises instead of the fuel temperature in the float chamber.

Next, the operation procedure of this embodiment will be explained.

First, when the temperature of the carburetor 1 is low, that is, when the temperature of the engine cooling water is low, the temperature switch 15 is turned off, so the L NO 13 is also turned off, and the pump 12 is stopped. At this time, the water jacket 8 does not contain cooling water and is filled with air, so it functions as a heat insulator.

When the temperature of the carburetor 1 rises and the fuel temperature in the float chamber 7 rises, that is, when the engine coolant temperature rises by -1, the temperature switch 15 turns on, the relay 13 turns on, and the pump 12 is powered on. is supplied to operate the pump. Then, the cooling water is supplied to the water jacket 8 via the supply passage 11, and at the same time, the cooling water returns from the water jacket 8 to the water storage tank 12 via the return passage 10, so that the cooling water flows between the water storage tank 9 and the water jacket 8.
and cools the vicinity of the float chamber 7 appropriately.

Here, by adjusting the amount of cooling water supplied from the diameter of the return passage 10 and the supply passage 1 into the water jacket 8, a gap 8b functioning as an evaporation chamber is secured in the upper part of the water jacket 8 for cooling. The heat of vaporization of water can be used, further improving cooling capacity.

Then, when the temperature of the carburetor 1 gradually decreases, that is, when the engine coolant temperature decreases, the temperature switch 15 and the relay 13 are turned off and the pump 12 is stopped. Then, the cooling water is not supplied to the water jacket 8 from the water storage tank 9 side, and all the cooling water returns from the water jacket 8 to the water storage tank 9 via the return passage 10. Therefore, as described above, the water jacket 8 functions as a heat insulating material 7, and there is no need to worry about cooling the vaporizer 1 more than necessary.

It goes without saying that 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 may be cooled. You may also do this. Further, in this embodiment, dedicated cooling water for cooling the vaporizer is used, but in reality, for example, the window washer fluid and its tank may also be used.

Furthermore, in this embodiment, a switch that detects the temperature of the engine cooling water is used as the temperature switch, but it can also be used as a switch for the engine cooling fan, or a separate switch or sensor that directly detects the temperature of the carburetor or its internal fuel. etc. may be provided.

[Effects of the Invention] As described above, according to the present invention, it is possible to directly and actively cool a fuel supply device such as a carburetor or a fuel injection device and its internal fuel with a simple structure.
It is possible to control the temperature of these within a desired range, and not only can an air-fuel ratio corresponding to the engine temperature be obtained, but also it is possible to prevent the materials forming the carburetor and throttle body from deteriorating due to temperature changes. From the above, the effects of the present invention are extremely large.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a vaporizer equipped with a cooling structure according to the present invention. 1... Vaporizer 7... Flow I/Chamber 8...
・Water jacket 8a...Air hole 8b...Gap 9...Water tank 10...Return passage 11...Supply passage
12...Pump 13...Relay 14
...Power supply 15...Temperature switch

Claims (4)

[Claims] (1) A cooling structure for a fuel supply device including a fuel storage tank near the engine, comprising: a water storage tank, a water jacket provided around the storage tank, and cooling water from the water storage tank to the water jacket. a passage for returning cooling water from the water jacket to the water storage tank; a passage provided in either one of the passages and selectively circulating the cooling water depending on the fuel temperature in the storage tank; What is claimed is: 1. A cooling structure for a fuel supply device, characterized in that it has a pump. (2) An air hole is opened in the upper part of the water jacket, the water tank is provided at a position where the water level of the internal cooling water is lower than the lower end of the water jacket, and both ends of the cooling water supply passage are connected to the water jacket. It opens at the lower end of the water storage tank and the upper end of the water jacket, and both ends of the cooling water return passage open at the lower end of the water jacket and the upper end of the water storage tank, and the cooling water return passage opens at the lower end of the water jacket and the upper end of the water jacket. The cooling structure for a fuel supply device according to claim 1, characterized in that a space is provided in the upper part. (3) The cooling structure for a fuel supply device according to claim 1 or 2, wherein the fuel supply device has a carburetor. (4) The cooling structure for a fuel supply device according to claim 1 or 2, wherein the fuel supply device includes a fuel injection device.