JPH073005Y2 - Intake heating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an intake air heating device for an engine. More particularly, it relates to a device for heating intake air in the intake manifold and slow fuel passages of a carburetor.

[Conventional technology]

2. Description of the Related Art Conventionally, during warm-up operation of an engine, the intake manifold is heated with warm water of cooling water after cooling the engine body to improve atomization of fuel. One example is shown in FIG. 3. In FIG. 3 (a), in an engine equipped with an engine body 1, an intake manifold 2, and a carburetor 3, the engine cooling water W from a radiator 4 is after cooling the engine. The water becomes hot water and returns to the radiator 4, and a part of the hot water enters the water jacket 26 provided in the intake manifold 2 through the thermo valve 8 to heat the intake air. While the engine is warming up, the intake air is heated with hot water in this way, and after warming up, a thermo valve (intake hot water heating control valve) 8 that automatically controls the amount of water according to the temperature of the hot water acts and the water jacket 26 The amount of hot water entering is controlled, and the filling efficiency is improved. FIG. 3 (b) shows a sectional view of the thermovalve. The arrow W in the figure indicates the direction of flow of hot water.

Further, conventionally, in order to improve the vaporization and atomization of the fuel ejected from the slow fuel passage of the carburetor and to prevent the freezing (icing) of the fuel, the passage for guiding the engine cooling water (hot water) is provided in the carburetor. It is known that the slow fuel passage is provided close to the slow fuel passage on a flange portion of the carburetor, and the slow fuel passage is heated by the cooling water. For example
Japanese Patent No. 59-131951 and Japanese Utility Model Laid-Open No. 60-52376 disclose ideas relating to this.

[Problems to be solved by the device]

The means for heating the intake manifold by using the warm water of the cooling water in the above-mentioned conventional intake air heating device to promote atomization of the fuel and the means for heating the slow fuel passage of the carburetor are separate for each engine. Are provided as means for controlling each of them. For this reason, when both heating devices are installed in the same engine as it is, more piping is required for the cooling water passage, and an additional control mechanism such as a thermo valve is required, which complicates the device. Failures are also likely to occur.

In the present invention, it is an object of the present invention to combine the above two means into one means to obtain an efficient heating device with a simple device to reduce the cost.

[Means for Solving the Problems]

In order to solve the above problems, in the present invention, an intake manifold and a carburetor of an engine having a cooling water passage for introducing cooling water of an engine body into an intake manifold and a carburetor in order to heat intake air. In this intake air heating device, the cooling water passage of the heating portion of the intake manifold is divided into a first passage and a second passage, and the engine cooling water that exits the engine body and is introduced into the intake manifold heating portion is The first passage, the intake heating portion of the carburetor, and the second passage are arranged in this order so as to circulate through the passages that surround the intake manifold heating portion and are arranged in series, and then return to the engine body via the thermo valve. An intake air heating device for an engine is provided.

[Action]

After the engine is started, the cooling water that has warmed up the engine body in warm-up operation first passes through the first passage, then reaches the intake heating part of the carburetor, then passes through the second passage, and passes through the thermo valve and the engine. It circulates in the cooling water passage in the order of returning to the main body, and the intake air of the intake manifold is heated through the inside wall of the intake pipe during that time to promote the atomization of the fuel, and the fuel of the slow fuel system of the carburetor is promoted. Improves vaporization and prevents its freezing. The circulation amount of the hot water is controlled by the thermo valve, the warm-up of the engine is completed, the normal operation state is entered, and when the temperature of the cooling water rises above a predetermined value, the thermo valve is closed and the circulation of the hot water is stopped.

〔Example〕

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of an intake air heating device according to the present invention, and FIG. 2 is an explanatory view of a cooling water flow system of an engine including the intake air heating device.

In FIG. 2, 1 is an engine body, 2 is an intake manifold, 3 is a carburetor, 4 is a radiator, 5 is a water pump, 6 is a thermostat housing, 7 is a thermostat, 9 is 1 and 4, 10 is 4 and so on. 6 and 11 are 6 and 5, 12 is 5 and 1
The water passages connecting each of them, 13 is a water bypass,
The above is the same as the arrangement of the cooling system found in a general engine.

The structure of the intake air heating device according to the present invention will now be described with reference to FIGS. 1 and 2. 28 is a cylinder head, 29 is an intake valve, and the cooling water heated by the engine body 1 is introduced to the intake air heating device 30. A water passage 14 is provided, and the water passage 14 communicates with the first passage 21. The first passage is divided by the partition wall 20 into the second passage.
It is separated from the passage 22 and communicates with the water passage 15. Water passage 15
Extends in the direction of the carburetor 3 through the pipe wall of the intake manifold 2 and enters the flange portion 24 from the primary 29p side of the carburetor main body 25, communicates with the carburetor intake air heating portion 19 provided therein, and vaporizes the same. The intake air heating section 19 communicates with the water passage 16 on the secondary 25s side of the carburetor body 25, the water passage 16 communicates with the second passage 22 through the inside of the pipe wall of the intake manifold 2, and further with the second passage.
The passage 22 communicates with the thermo valve 8 via the water passage 17, and further communicates with the thermostat housing 6 via the water passage 18. In this way, from the water passage 14 to the thermostat housing 6
A series circulation route of hot water is formed. In the figure, arrow W indicates the direction in which engine cooling water (warm water) flows, and 23 indicates a heat insulator of the carburetor.

The operation of the intake air heating device having the above-described structure will be described. First, the hot water that has entered the first passage 21 heats the intake air in the intake manifold 2 with the hot water, and then passes through the water passage 15, where the intake air is further taken. After heating, the carburetor intake air heating unit 19 heats the slow fuel passage of the carburetor, and then the hot water passes through the water passage 16, at which time the intake air in the intake manifold 2 is heated again and returned to the second passage. After further heating the intake manifold 2, the thermo valve 8 is entered. The thermo-valve 8 is automatically opened / closed by the temperature of the hot water after the engine is warmed up, and the amount of hot water circulating in the water passage in the intake air heating device 30 is controlled. That is, after the engine is started, the engine is warmed up, the temperature of the hot water rises, and especially after the engine is in a state where it can continue normal operation without promoting the atomization of fuel by heating the intake air, the thermo valve 8 is used. The flow of hot water is stopped, the heating of intake air is stopped, expansion of the volume of intake air is suppressed, and filling efficiency is improved. The control set value of this thermo valve is usually 50 to 60 ° C, and the thermo valve closes when the temperature exceeds this value.

As described above, heating of the intake manifold portion and heating of the carburetor flange portion, which have conventionally been performed separately, are performed by combining them into one means by providing a series of circulating water passages arranged in series. It is possible to simultaneously control the heating by means of one thermo valve, which simplifies the device, reduces the cost, and prevents malfunctions.

In addition, warm water is the first to heat the intake manifold heating unit 27 intake air.
The heating is performed through a wide range of the inner wall of the intake pipe that surrounds the intake manifold heating unit 27 by performing it when flowing through the passage 21, the water passage 15, the water passage 16, and the second passage 22, so that a small amount of hot water can be circulated. The atomization of fuel is efficiently promoted.

In addition, although a two barrel type carburetor is taken as an example in the present embodiment, the present invention is not limited to this and can be applied to other types of carburetors.

[Effect of device]

 The following effects can be obtained by implementing the present invention.

(1) Simultaneous heating of the carburetor flange portion and the intake manifold portion by means of one series of circulating water passages by one means simplifies the device, prevents failures, and reduces costs.

(2) Since the intake air in the intake manifold is heated through the inner wall of the intake pipe over a wide range, the atomization of fuel can be efficiently promoted by circulating a small amount of warm water.

(3) Since the hot water that has exited the engine body is first supplied only to the first passage side and then the hot water is supplied to the carburetor, compared to the case where hot water is supplied to the entire intake manifold heating section, the temperature Can supply cooling water without deterioration to the vaporizer,
Early heating of the carburetor can be achieved at the time of cold start.

[Brief description of drawings]

FIG. 1 is a sectional view of an intake air heating device according to an embodiment of the present invention,
2 is an explanatory view of a cooling water running water system of an engine including the intake air heating device of FIG. 1, FIG. 3 shows an intake air heating device according to a conventional example, (a) is an explanatory view of the cooling water running water system, (b) Shows a sectional view of the thermovalve. 1 ... Engine body, 2 ... Intake manifold, 3 ... Vaporizer,
8 ... Thermo valve, 19 ... Intake heating part, 20 ... Partition wall, 21 ... First passage, 22 ... Second passage, 27 ... Intake manifold heating part, 30
… Intake heating device, W… Engine cooling water.

Claims (1)

[Scope of utility model registration request] 1. An intake manifold for an engine and an intake heating device for a carburetor having a cooling water passage for introducing cooling water of an engine body to an intake manifold and a carburetor for heating intake air, comprising: A partition is provided in the cooling water passage to divide it into a first passage and a second passage, and the engine cooling water that exits the engine body and is introduced into the intake manifold heating portion is the first passage, the intake heating portion of the carburetor, and the An intake air heating apparatus for an engine, configured to circulate through a path surrounding the intake manifold heating section in series in the order of a second path and then return to the engine body via a thermo valve.