JPH1193635A - Breather device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the freezing of moisture in the blow-by gas in a device, in which the blow-by gas inside of a crank chamber is led to an air intake passage from a blow-by gas passage so as to be combusted in a combustion chamber, by forming a joint for connecting an air intake passage and the blow-by gas passage to each other of a member having a heat insulating property. SOLUTION: A carburetor 4 is connected to an air intake port of a cylinder head of an engine main body, and an air intake pipe 6 is connected to an inlet of the carburetor 4 through a flange 5. A joint 7 is arranged in the flange 5, and an outlet side of a blow-by gas passage 8 is connected to the joint 7. At this stage, the joint 7 is formed of a member having a heat insulating property such as synthetic resin and ceramic. An inlet side of the blow-by gas passage 8 is connected to an oil separating device, and the oil separating device is communicated with a crank chamber. With this structure, moisture in the blow-by gas passing through inside of the joint 7 is hard to be frozen, and discharge of the blow-by gas from the crank chamber to the carburetor 4 side is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breather device for guiding blow-by gas to a combustion chamber of an engine via an intake passage for combustion.

[0002]

2. Description of the Related Art Conventionally, there has been a method in which blow-by gas in a crankcase is directly discharged into the atmosphere to adjust the pressure in the crankcase. However, the blow-by gas contaminates the atmosphere. For this reason, a system in which the blow-by gas is guided to an intake passage through a blow-by gas passage and burned in a combustion chamber has been adopted.

[0003]

However, gasoline
In an engine or the like, a carburetor is disposed in the intake passage, and the carburetor is cooled by heat of vaporization of fuel. Then, the cold heat is transmitted to the joint connecting the blow-by gas passage and the intake passage, so that the joint is cooled. For this reason, immediately after a cold start, the moisture contained in the blow-by gas freezes in the joint and adheres to the inner surface of the joint.

[0004] Then, the inside of the joint is blocked by ice adhering to the inner surface of the joint, so that blow-by gas is not discharged from the crank chamber and the pressure in the crank chamber becomes excessive, which may cause a decrease in engine performance. there were. SUMMARY OF THE INVENTION It is an object of the present invention to prevent a joint connecting a blow-by gas passage and an intake passage from being blocked by ice, and to reliably discharge blow-by gas from a crank chamber to an intake passage.

[0005]

[Means for Solving the Problems]

[Claim 1] The invention of claim 1 is configured as follows, for example, as shown in FIGS. 1 and 2, in order to achieve the above object. In a breather device of an engine in which blow-by gas in a crank chamber is guided to an intake passage (6) through a blow-by gas passage (8), the blow-by gas is burned in a combustion chamber.
Joint (7) connecting the blow-by gas passage (8)
Is composed of a member having heat insulation properties. In addition,
As the joint (7), a member having heat insulation such as synthetic resin or ceramic is applied.

[Claim 2] In order to achieve the above object, according to the invention of claim 2, for example, as shown in FIG.
It is configured as follows. The blow-by gas in the crank chamber is supplied to the intake passage through the blow-by gas passage (8).
In the breather device of the engine in which the blow-by gas is burned in the combustion chamber by leading to (6),
A water jacket (18) is provided at a joint (17) connecting the intake passage (6) and the blow-by gas passage (8), and the engine cooling water is circulated through the water jacket (18).

[0007]

[Action]

[Claim 1] The invention of claim 1 is, for example, shown in FIGS.
As shown in FIG. The blow-by gas in the crank chamber is introduced into the blow-by gas passage (8) through a gas passage in the engine, a cylinder head cover, and the like. Then, the blow-by gas is introduced into the intake passage (6) through the blow-by gas passage (8), and is guided to the combustion chamber together with the intake gas and the vaporized gas of the fuel to burn.

On the other hand, the vaporization of the fuel in the vaporizer (4) cools the vaporizer (4) and the intake passage (6) with heat of vaporization, and the cold heat is cooled by the intake passage (6) and the blow-by gas passage ( 8) to the joint (7) that connects the same. However, the joint (7) is not cooled much by its heat insulating action. As a result, the blow-by gas passing through the joint (7) becomes difficult to be cooled, and the moisture contained in the blow-by gas freezes to form the joint.
(7) is prevented from adhering to the inner surface.

[Claim 2] The invention of claim 2 has substantially the same operation as the invention of claim 1,
For example, as shown in FIG. That is, when the engine cooling water circulates through the water jacket (18) provided in the joint (17), the joint (17) is heated by the heat of the engine cooling water. by this,
Moisture contained in blow-by gas freezes and joints
(7) is prevented from adhering to the inner surface.

[0010]

【The invention's effect】

[Claim 1] The invention of claim 1 has the following effects because it is configured and operates as described above. Although the vaporizer and the intake passage are cooled by the heat of vaporization of the fuel in the vaporizer, the joint that connects the intake passage and the blow-by gas passage can prevent the joint from being cooled. It is possible to prevent the moisture contained in the gas from freezing inside the joint and attaching to the inner surface of the joint, thereby blocking the joint.
Therefore, the blow-by gas can be reliably discharged from the crank chamber and burned in the combustion chamber. Thereby, the pressure in the crank chamber is appropriately adjusted, and the engine performance can be maintained.

[Claim 2] The invention of claim 2 has the following effects because it is configured and operates as described above. Since the joint is actively heated with the engine cooling water, blow-by gas passing through the joint is also warmed. Therefore, the moisture contained in the blow-by gas is reliably prevented from freezing, and the joint can be more reliably prevented from being blocked with ice. As a result, the blow-by gas can be more reliably discharged from the crank chamber, the pressure in the crank chamber can be more reliably adjusted, and the engine performance can be more reliably maintained.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a breather device for an engine according to the present invention will be described below with reference to FIGS. 1A and 1B show a joint according to the present invention. FIG. 1A is a view showing a state in which the joint is attached to a flange, and FIG.
1 (C) is a cross-sectional view taken along line CC of FIG. 1 (B). FIG. 2 is a plan view of the engine according to the present invention.

[0013] The engine body (1) is a cylinder block.
(2) and a cylinder head (3), and a carburetor (4) is connected to an intake port (not shown) of the cylinder head (3). Flange (5) at the inlet of the vaporizer (4)
And an intake pipe [intake path] (6). A joint (7) is arranged on the flange (5),
The outlet side of the blow-by gas passage (8) is connected to the joint (7). The joint (7) is made of a heat-insulating member such as a synthetic resin or ceramic. The joint (7) connects the intake pipe (6) to the blow-by gas passage (8).

The inlet side of the blow-by gas passage (8)
Oil separator (1) located on the cylinder head cover (9)
Connected to 2). The oil separating device (12) communicates with a crank chamber (not shown). In addition, the intake pipe (6)
Is connected to an air supply device (not shown) composed of an air cleaner or the like. A gasket (13) is interposed between the vaporizer (4) and the flange (5).

As described above, since the joint (7) is formed of a member having heat insulating properties, the carburetor (4) and the intake pipe are formed.
(6) is cooled by the heat of vaporization of the fuel in the carburetor (4), and even if the cold heat is transmitted to the joint (7), the joint (7) is not cooled much by the heat insulating action. As a result, the blow-by gas passing through the joint (7) is less likely to be cooled, and the moisture contained in the blow-by gas is less likely to be frozen.
It is possible to prevent the blow-by gas from being exhausted from the crank chamber to the carburetor (4) side due to the inside being blocked with ice.

Next, a second embodiment of the breather device for an engine according to the present invention will be described with reference to FIG. 3A is a longitudinal sectional view showing a joint according to the second embodiment, FIG. 3B is a view taken along the line BB of FIG. 3A, and FIG. It is a schematic diagram explaining connection of a joint concerning an embodiment, and a water jacket of an engine main part.

The joint (17) is provided with a water jacket (18) along the outer peripheral surface thereof. The water jacket (18) is connected to the engine via a water supply pipe (19) and a drain pipe (20). Cooling water recirculates. That is,
The inlet of the water supply pipe (19) communicates with a bypass (22) connecting the outlet (24) of the water jacket of the engine body (1) and the inlet of the water pump (21). The outlet of the pipe (20) communicates with the outlet side of the water pump (21).

A partition plate (18a) is provided in the water jacket (18) of the joint (17), and as shown by an arrow in FIG. 3B, the partition plate (18a) is provided. Partition between the outlet of the water supply pipe (19) and the inlet of the drainage pipe (20), from the water supply pipe (19) to the water jacket.
The engine cooling water flowing into (18) flows in the circumferential direction of the joint (17), and is then discharged from the drain pipe (20).

As described above, a part of the engine cooling water warmed by the engine body (1) flows back to the water jacket (18) of the joint (17), and the joint (17) is formed by the engine cooling water. As it is warmed, joint (1
7) The blow-by gas passing through the inside is not cooled, and the moisture contained in the blow-by gas is hard to freeze.

In the above description, the inlet of the water supply pipe (19) is connected to the bypass (22). This is because when the engine is cold, such as immediately after a cold start, the moisture contained in the blow-by gas tends to freeze, but at that time, the thermostat (23) is closed, so the engine body ( This is because the engine cooling water from the water jacket of 1) does not flow to the radiator (25) but flows to the bypass passage (22). In other words, the communication point at the inlet of the water supply pipe (19) may be any point where the engine cooling water warmed by the water jacket of the engine body (1) flows, and for example, the outlet (24) of the water jacket of the engine body (1). ).

In the above description, the joint (17)
The engine coolant flowing into the water jacket (18) flows in the circumferential direction of the joint (17), but is not limited to this.The heat of the engine coolant is transmitted to the joint (17). The water jacket (18) may be provided only on a part of the outer periphery of the joint (17), as long as the joint (17) can be warmed. Further, instead of the water jacket (18) of the joint (17), an oil jacket may be provided along the outer peripheral surface of the joint (17), and engine oil may be returned to the oil jacket.

[Brief description of the drawings]

FIG. 1 shows a first embodiment of a breather device for an engine according to the present invention, and FIG. 1 (A) shows a state in which a joint according to the first embodiment is attached to a flange. 1 (B) is a view taken along line BB of FIG. 1 (A), and FIG.
(C) is a sectional view taken along line CC of FIG. 1 (B).

FIG. 2 is a plan view of an engine according to the present invention.

FIG. 3 shows a second embodiment of a breather device for an engine according to the present invention, and FIG. 3 (A) is a longitudinal sectional view showing a joint according to the second embodiment, and FIG. 3 (B). FIG. 3A is a view taken along line BB of FIG. 3A, and FIG. 3C is a schematic view for explaining connection between the joint according to the second embodiment and a water jacket of an engine body.

[Explanation of symbols]

6 ... intake pipe (intake path), 7 · 17 ... joint, 8 ... blow-by gas passage, 18 ... joint water jacket.

Claims (2)

[Claims] 1. A breather device for an engine, wherein a blow-by gas in a crank chamber is guided to an intake passage (6) through a blow-by gas passage (8) so that the blow-by gas is burned in a combustion chamber. A breather device for an engine, wherein a joint (7) for connecting the intake passage (6) and the blow-by gas passage (8) is made of a member having heat insulation. 2. A breather device for an engine in which blow-by gas in a crank chamber is guided to an intake passage (6) through a blow-by gas passage (8) to burn the blow-by gas in a combustion chamber. A water jacket (18) is provided at a joint (17) connecting the passage (6) and the blow-by gas passage (8), and engine cooling water is circulated through the water jacket (18). Engine breather device.