JPS6244117Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an intake system for a vertical internal combustion engine that uses exhaust heat to preheat intake air and prevent icing.

In particular, for vessels equipped with inboard and outboard motors or outboard motors, when trolling in humid and low temperature fishing, the slot valves and jets in the carburetor may freeze due to the moisture in the intake air. There is a risk that the throttle may become inoperable.
This may cause engine problems such as engine malfunction or stalling.

Furthermore, as a prior art for preheating this kind of intake air, there is a heat exchanger for taking out hot air in a warm air intake device described in Japanese Patent Application Laid-open No. 52-85619, but this is because the exhaust pipe at the heat exchanger part is constricted. In this configuration, the intake air is subjected to exhaust resistance, while the intake air to be warmed passes through the gap formed on the outer periphery of the narrowed exhaust pipe, so the intake air also receives resistance, and the heat exchanger section is separated from the cylinder to reduce the exhaust temperature. It is installed in the exhaust pipe that goes down.

The present invention has been developed in view of the above-mentioned points. A shielding plate is provided inside the exhaust cover of the exhaust passage provided in the cylinder, and the shielding plate allows the preheating of the air adjacent to the exhaust passage to be partitioned into the exhaust cover. In addition to forming a chamber, an air inlet is provided in the air preheating chamber,
By communicating this air preheating chamber with the intake system of an air cleaner or the like through a communication pipe, it can be used for inboard/outboard motors and outboard motors, making it possible to use the carburetor when trolling in humid, low-temperature fishing areas. The air sucked into the engine passes through the preheating chamber and is preheated by exhaust heat, preventing the throttle valve and jets in the carburetor from freezing and preventing engine troubles such as inability to operate the throttle, engine malfunction, and engine stalling. An object of the present invention is to provide an intake system for a vertical internal combustion engine that prevents dangers such as drifting due to

Another object of the present invention is to provide an intake system that can be implemented not only in the above-mentioned inboard/outboard motors and outboard motors, but also in general vertical internal combustion engines used in cold regions.

Next, an embodiment in which the present invention is applied to an outboard motor will be described with reference to the drawings.

An exhaust passage 1 is formed in a cylinder 3 having a water jacket 2;
An exhaust cover 4 having a concave portion constituting a part of the water jacket 2 is screwed onto the side surface of the cylinder 3, which has a recess formed therein, and closes the exhaust passage 1 in the outward direction. The shielding plate 5 is disposed on the joint surface between the exhaust cover 4 and the side surface of the cylinder 3 forming the exhaust passage 1 . This shielding plate 5 defines an air preheating chamber 6 adjacent to the exhaust passage 1 within the exhaust cover 4 .

The air preheating chamber 6 has one end opened to form an air inlet 7, and a heat sink 8 with a wide heat radiation area is fixed to the shielding plate 5 inside the air preheating chamber 6. It is protruding from the
The upstream end of the connecting pipe 9 is fitted into the upper opening on the other end side of the preheating chamber 6, and the air cleaner 1 is connected to the downstream side.
The air preheating chamber 6 is connected to the communication pipe 11 to which the air preheating chamber 6 is connected to the air cleaner 10 . The connecting portion between the communicating pipe 11 and the connecting pipe 9 is fastened by a clamp 12.

The air cleaner 10 has a cleaner housing 13 that is open on one side, and has an air intake port 14 in normal operation that communicates directly with the outside air, and an air intake port 15 in the case of preventing icing. A connecting pipe 16 is connected to the intake port 15, and the communicating pipe 11 is connected to this connecting pipe 16 and fastened with a clamp 17. In this air cleaner 10, a rotation switching body 19 having a communication port 18 is fitted into the cleaner housing 13 from the opening surface, and by aligning the communication port 18, the air intake ports 14 and 15 can be switched. ing. The rotation switching body 19 has an annular grip portion 20 carved with a knurl, and an exposed surface 21 with a mark 2 indicating the position of the communication port 18.
2 has been applied. On the other hand, the cleaner housing 13 has a projecting piece 23 projecting in the outer circumferential direction.
Markers 24 such as "Icing Prevention" and "Normal" are placed at each air intake port 14 and 15 position.

In the figure, reference numeral 25 is the filter element of the air cleaner, 26 is the carburetor, 27 is the cylinder head, 28 is the recoil starter, and 29
indicates a gasket.

Next, the operation of the present invention will be explained.

In the intake system of the outboard motor according to the embodiment of the present invention, the air intake port 14 during normal operation and the air intake port 15 during icing prevention can be changed by rotating the rotation switching body 19 of the air cleaner 10. can be switched freely. When the air intake port (for preventing icing) is switched to the air intake port 15, air is sucked from the suction port 7 into the preheating chamber 6 adjacent to the exhaust passage 1, and this intake air conducts the exhaust heat in the preheating chamber 6. The air is preheated by the air and sucked into the air cleaner 10 through the communication pipe 11. Therefore, even when trawling in a humid and low-temperature fishing industry, the air sucked into the carburetor 26 is warmed in advance, which prevents icing and improves atomization of the air-fuel mixture.

As explained above, according to the present invention, the air preheating chamber is provided in the cylinder and is adjacent to the exhaust passage formed in the cylinder, so that the loss of exhaust heat is small and the effect of preheating the intake air is large. In addition, by providing a heat sink on the shielding plate that partitions the exhaust passage and the air preheating chamber, the contact area on the air preheating chamber side can be increased and heat exchange efficiency can be improved. Since both the passage and the air preheating chamber have a passage structure with low flow resistance, there is no exhaust or intake resistance. Furthermore, there is an effect that the configuration for switching between the intake of preheated air for preventing icing and the air intake during normal operation can be easily configured.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view showing an embodiment of the device of the present invention, Fig. 2 is an enlarged sectional view taken along the - line in Fig. 1, Fig. 3 is an enlarged sectional view taken along the - line in Fig. 1, and Fig. 4 is an enlarged sectional view taken along the - line in Fig. 1. Figure 1 is an enlarged sectional view taken along the - line, Figure 5 is A in Figure 1.
It is a direction arrow diagram. In the figure, reference numeral 1 indicates an exhaust passage, 3 a cylinder, 4 an exhaust cover, 5 a shielding plate, 6 a preheating chamber, 7 an air intake port, 11 a communication pipe, and 10 and 26 an intake system.

Claims (1)

[Scope of utility model registration request] In a gasoline engine equipped with a carburetor, an exhaust passage whose outer surface is open is formed in the outer wall of the cylinder, and the opening of the passage is covered with an exhaust cover having a concave cross section and forming a part of the cylinder outer wall to close the opening. At the same time, a shielding plate is disposed at the joint between the opening end surface of the exhaust passage and the opening end surface of the exhaust cover to form an air preheating chamber partitioned and adjacent to the exhaust passage within the concave exhaust cover, and the air preheating chamber side is A heat dissipation plate is provided on the shielding plate, and one end of the air preheating chamber is used as an air intake port, while the other end is provided with an air intake for preventing icing of an air cleaner disposed upstream of the carburetor via a communication pipe. This air cleaner also has a normal air intake that communicates directly with the outside air, and is connected to the icing prevention air intake and the normal air by switching a switching member provided on the air cleaner. An intake device for a vertical internal combustion engine, characterized in that it is configured to switch between an intake port and an intake port.