JPS6233049Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an arrangement structure of a ventilation pipe for blow-by gas of an engine used in, for example, a cab-over type automobile.

[Conventional technology]

The ventilation pipe that connects the engine body and the intake system passage in order to introduce the blowby gas from the engine into the intake system passage is susceptible to freezing due to condensed water separated and liquefied from the blowby gas during cold weather such as winter.

[Problem that the invention attempts to solve]

As a result of the coagulated water freezing in this way, the diameter of the pipe is narrowed and the blow-by gas flow path is obstructed. In particular, when an engine is mounted on a cab-over type automobile as shown in Fig. 3 disclosed in Utility Application No. 17784, a carburetor b and an air cleaner c are mounted on the engine body a which is left tilted. The ventilation pipes must be arranged horizontally at approximately the same height, and as a result, the distance between the engine body a and the air cleaner c is relatively increased. The length of d also increases, and the heat dissipation between them increases.Therefore, there is a problem that the moisture remaining in the blow-by gas tends to condense in the ventilation pipe d, and the condensed moisture tends to freeze. Freezing prevention was requested.

[Purpose of invention]

The present invention is based on the idea of connecting a ventilation pipe and an exhaust gas recirculation pipe with elasticity using a clamp made of a spring material with good conductivity. The object of the present invention is to provide a ventilation pipe arrangement structure (hereinafter referred to as structure) for blow-by gas that can prevent moisture from freezing and meet the above requirements.

[Means for solving problems]

Since the present invention can meet the above requirements, the engine main body 2 and the air cleaner 4 are connected to the flexible portion 1 as described above.
A blow-by gas supply whose one end is connected to the engine body 2 is connected to the upstream side of the flexible portion 11 of the intake path 12 that supplies air from the air cleaner 4 to the engine body 2 using a pipe 10 having a The other end of the supply ventilation pipe 5 is connected to the exhaust gas recirculation pipe 6 which connects the exhaust system path 17 and the intake system path 12, and the ventilation pipe 5 is connected to the ventilation pipe 5 with good heat transfer properties. The clamps 35 are made of a spring material and are connected with spring properties.

[Effect]

Since the exhaust gas recirculation pipe 6 and the ventilation pipe 5 can exchange heat via the clamp 35, the heat of the exhaust gas passing through the exhaust gas recirculation pipe 6 liquefies the moisture in the blow-by gas. , which can prevent freezing and smooth the flow of blow-by gas.

Furthermore, since the pipe 6 for exhaust gas recirculation and the ventilation pipe 5 are connected with each other with spring properties, the ventilation pipe 5 is connected to the exhaust gas recirculation pipe 5 as the engine body 2 and the air cleaner 4 move relative to each other during running.
Even if the ventilation pipe 5 is displaced, the ventilation pipe 5 will not be damaged and the risk of gas leakage can be prevented.

〔Example〕

One embodiment will be described below based on the drawings.

The figure shows engine body 2 on a cab-over type car.
The ventilation pipe 5 and the exhaust gas recirculation pipe 6 are arranged so as to have a heat exchange relationship. The carburetor 3 is connected to the engine body 2 via an intake manifold 7, and has a flexible portion 9 formed with a bellows portion between the carburetor 3 and the air cleaner 4, and a flexible portion 9 on the upstream side of the flexible portion 9. A pipe 11 having a cylindrical portion 10 disposed in the cylindrical portion 10 is used for communication. Therefore, it is obvious that the air cleaner 4 is connected to the engine main body 2 so as to be relatively movable. The space between the air cleaner 4 and the intake manifold 7 constitutes an intake system path 12 that supplies intake air to the engine body 2.

The ventilation pipe 5 has one end connected to a discharge port 16 of an oil separator 15 provided in the cylinder head cover 13 of the engine body 2, and the other end communicated with the cylindrical portion 10 of the pipe 11. Then, the blow-by gas leaking into the engine body 2 is sent to the intake system path 12 and re-burned in the cylinder. The oil separator 15 has, for example, a maze-like passage, and can separate mist-like oil in the blow-by gas into gas and liquid, and return the liquefied oil to the engine body 2. Further, the other end of the ventilation pipe 5 can be directly connected to the air cleaner 4 as illustrated by the dashed line.

The exhaust gas recirculation pipe 6 is connected to the exhaust system path 1.
7 For example, a base pipe 2 whose one end is attached to the base of the exhaust manifold 19 by a flange.
0, and a pipe 23 which has one end connected to a branch pipe of an exhaust gas recirculation valve 21 attached to the other end of the base pipe 20 and whose other end leads to the downstream side of the intake system path 12, for example, the carburetor 3, and is inert. circulating and feeding a part of the exhaust gas to the intake system path 12;
It constitutes a so-called exhaust gas recirculation device that can lower the temperature during combustion and reduce the production of NOx by mixing it into the intake air-fuel mixture.

The clamp 35 is formed using a spring material with good heat conductivity such as metal, and has recesses 31 and 31 on opposite sides for pipe insertion as illustrated in FIG. 2, and is screwed together using a bolt 32. By forming the other ends of the clamp pieces 33 and 34 into a U-shape that can be pushed out, the reflux pipe 6 and the ventilation pipe 5 have a spring property. and combine them.

However, in the structure of this embodiment, even in cold weather such as winter, the ventilation pipe 5 is heated by the exhaust gas recirculation pipe 6 through which the high temperature exhaust gas discharged from the exhaust gas 17 passes. It prevents the moisture in the blow-by gas from liquefying inside, and also prevents the liquefied coagulated water from freezing inside, and can immediately evaporate even when it freezes, such as when the blow-by gas is stopped. This helps purify exhaust gas, and also improves engine performance and life by smoothing out blow-by gas.

Furthermore, since the clamp 35 has spring properties, the displacement of the ventilation pipe 5 caused by the relative movement between the engine body 2 and the air cleaner 4 during running etc. can be absorbed by the elastic deformation of the clamp pieces 33 and 34. This prevents damage to the attachment part to the gas recirculation pipe 6.

Note that the air cleaner 4 can be divided into two parts, and
Filter element 2 is placed inside the lower box parts 26 and 27.
9 is shown as an example, other types of air cleaners may be used, and the clamp 35 may be formed so that a metal material is interposed only in the heat exchange-related and springy portions.

[Effects of the invention] As mentioned above, the structure of the invention connects the exhaust gas recirculation pipe and the ventilation pipe so that they have a heat exchange relationship. It prevents the moisture inside from freezing and even when it freezes, it can be immediately evaporated and sent to the intake system, which not only helps purify exhaust gas but also improves engine performance, and in particular can reduce the overall height of the engine equipment. . In addition, since the ventilation pipe and the heat exchange pipe are connected with spring properties, the connection between the two becomes flexible, eliminating the risk of gas leakage due to breakage of the ventilation pipe. As a result, the ventilation pipe can be suitably employed in an engine device used in a cab-over type automobile or the like in which the ventilation pipe extends in the lateral direction.

[Brief explanation of the drawing]

The first is a front view showing an embodiment of the present invention, the second is a perspective view illustrating the heat exchange relationship between the ventilation pipe and the exhaust gas recirculation pipe, and the third is a front view illustrating the conventional structure. It is a diagram. 2... Engine body, 3... Carburetor, 4... Air cleaner, 5... Ventilation pipe, 6... Exhaust gas recirculation pipe, 11... Flexible part, 12... Intake system path, 17... Exhaust system path, 35... Clamp .

Claims (1)

[Scope of utility model registration request] A blowby connecting the engine body and the air cleaner using a pipe having a flexible portion, and having one end connected to the engine body on the upstream side of the flexible portion of the intake path that supplies air from the air cleaner to the engine body. While connecting the other end of the ventilation pipe for gas supply, a clamp made of a spring material with good heat conductivity is used to connect the exhaust gas recirculation pipe that connects the exhaust path and the intake path to the ventilation pipe. Ventilation pipe arrangement structure for Barrow By-Gas, which is made up of elastically bonded ventilation pipes.