JPH0645607Y2 - Supercharger for vehicle - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a supercharger for a vehicle, in particular, preventing deterioration of the function of a PCV valve, and causing moisture in blow-by gas to adversely affect the operation of an internal combustion engine. The present invention relates to a supercharging device for a vehicle, which can prevent the occurrence of the above and improve the operating state of the internal combustion engine, and also can simplify the configuration and reduce the cost.

[Conventional technology]

In an internal combustion engine, blow-by gas leaking from the combustion chamber through the gap between the piston and the cylinder wall into the crankcase is generated. Since this main component is an unburned gas and contains a large amount of HC, it is necessary to lead it to the combustion chamber again and reburn it. For this reason, there is a blow-by gas recirculation mechanism, and as a generally used method, the negative pressure of the intake system of the internal combustion engine is used to suck air into the air cleaner, the intake passage, or both, and recirculates during intake air to recirculate again. It is led to the combustion chamber and burned. Further, a PCV valve is provided in the blow-by gas recirculation mechanism in order to adjust the amount of recirculation of blow-bycus to the intake system.

In such a blow-by gas recirculation mechanism 50, as shown in FIG. 4, the air cleaner 14 and the inside of the cylinder head cover 52 of the internal combustion engine 2 are communicated with each other by a venturation three-way hose 54, and the PCV valve 30 is connected to the carburetor 10. Some are arranged in the manifold collecting portion A of the intake passage 4 on the downstream side. Reference numeral 12 is a throttle valve.

Further, in the internal combustion engine, a supercharger having a compressor provided in the intake passage and a turbine provided in the exhaust passage is provided to increase the amount of air supplied to the internal combustion engine and improve the output of the internal combustion engine.

As such an internal combustion engine with a supercharger, for example, Japanese Patent Laid-Open No.
-291723 is disclosed. The one described in this publication connects the upstream side and the downstream side of the supercharger with a bypass passage, and a bypass control valve is provided in the bypass passage.
Then, by closing the bypass under the non-operating condition of the supercharger, which is adjacent to the condition for switching the supercharger from stopped to activated, the rotor speed at the next transition to the supercharger operating condition is maintained high. , To suppress the occurrence of shock.

[Problems to be solved by the invention]

However, in the conventional device, when the location of the PCV valve is not appropriate, there is an inconvenience that the water in the blow-by gas freezes in the PCV valve and its function deteriorates, and the water discharged from the PCV valve is When the internal combustion engine is stopped, etc., it flows into the throttle valve side of the carburetor and freezes,
This causes malfunctions such as poor operation of the throttle valve, deterioration of startability, and deterioration of operating conditions of the internal combustion engine.

[Purpose of device]

Therefore, the purpose of this invention is to eliminate the above-mentioned inconveniences.
A supercharging pressure control valve that controls the supercharging pressure in the intake passage on the downstream side of the supercharger is provided in the middle of the bypass passage, and blow-by gas is blown into the bypass passage communicating from the supercharging pressure control valve to the intake passage on the upstream side of the supercharger. By providing the PCV valve of the reflux mechanism, the PCV valve is prevented from freezing and the function of the PCV valve is fully exerted, and the moisture in the blow-by gas is prevented from adversely affecting the operation of the internal combustion engine. The purpose of the present invention is to realize a vehicle supercharger that can be inexpensive and have a simplified structure.

[Means for solving problems]

In order to achieve this object, the present invention provides a bypass passage that connects the upstream side and the downstream side of the supercharger of the intake passage, and the supercharger in the intake passage on the downstream side of the supercharger is provided in the bypass passage. A supercharging pressure control valve for controlling the pressure is provided, and the supercharging pressure control valve is connected to the bypass passage communicating with the intake passage on the upstream side of the supercharger in the blow-by gas recirculation mechanism.
It is characterized by having a PCV valve.

[Action]

According to the configuration of this invention, since the PCV valve is provided in the bypass passage communicating from the supercharging control valve to the intake passage on the upstream side of the supercharger, the PCV valve is a high temperature mixture from the downstream side of the supercharger. While being heated by, the moisture of the blow-by gas from the PCV valve is efficiently discharged by the mixed air flow from the supercharging control valve. As a result, it is possible to prevent the PCV valve from freezing so that the function of the PCV valve is fully exerted, and the moisture of the blow-by gas is prevented from adversely affecting the operation of the internal combustion engine, and the internal combustion engine can be operated satisfactorily. .

〔Example〕

Embodiments of the present invention will be described in detail and specifically below with reference to the drawings.

1 to 3 show an embodiment of this invention. In the figure, 2 is an internal combustion engine, 4 is an intake passage, 6 is a combustion chamber,
8 is a supercharger, 10 is a carburetor, 12 is an intake throttle valve, 14 is an air cleaner, and 16 is an exhaust passage. The supercharger 8 is provided in the intake passage 4 downstream of the carburetor 10. As a result, the intake passage 4 is divided into a first intake passage 4-1 on the upstream side of the supercharger 8 and a second intake passage 4-2 on the downstream side of the supercharger 8.

In the first intake passage 4-1 and the second intake passage 4-2,
The respective ends of the bypass passages 18 that bypass the supercharger 8 communicate with each other. The second intake passage 4-2 is formed by, for example, the intake manifold 20, as shown in FIG. Also,
A supercharging pressure control valve 22 that controls the supercharging pressure of the second intake passage 4-2 on the downstream side of the supercharger 8 is provided in the middle of the bypass passage 18. As a result, the bypass passage 18 is the first bypass passage 18 between the second intake passage 4-2 and the boost pressure control valve 22.
-1 and a second bypass passage 18-2 between the supercharging pressure control valve 22 and the first intake passage 4-1 are configured separately. The second bypass passage 18-2, as shown in FIG.
Is formed into 24.

In addition, in this embodiment, as shown in FIG.
At the bottom 24a of the passage wall 24 forming the bypass passage 18-2, a water storage portion 26 for retaining the water in the blow-by gas is formed.

The supercharging pressure control valve 22 holds the supercharging pressure, which is the intake pipe pressure in the second intake passage 4-2, at a predetermined value, and the supercharging pressure equal to or higher than the predetermined value is on the downstream side of the supercharger 8. Second intake passage 4-
When acting on No. 2, it allows the pressurized mixture to flow from the first bypass passage 18-1 to the second bypass passage 18-2.

Further, in this embodiment, as shown in FIGS. 1 to 3, the PCV valve 30 of the blow-by gas recirculation mechanism 28 is set to the second position.
Bypass passage 18-2 midway or the second bypass passage
Provided near the outlet 32 of 18-2.

On the other hand, the float chamber 34 of the vaporizer 10 is connected to a leak passage 36 for introducing the intake pressure on the upstream side of the vaporizer 10 in order to maintain the pressure of the float chamber 34. Also, this leak passage
A ball vent valve (BVV) 38 that adjusts the leak pressure is installed in the middle of 36.

The float chamber 34 of the vaporizer 10 has a pressure introducing passage 40.
Through the second intake passage 4-2. In the middle of the pressure introducing passage 40, an electric pressure switching valve 42 that is turned on by a starter signal and a water temperature detecting valve 46 that senses and operates the cooling water temperature of the cooling water passage 44 are provided in series. As a result, when the internal combustion engine 2 is cold started, the pressure in the float chamber 34 of the carburetor 10 is increased to increase the fuel supply.

Next, the operation of this embodiment will be described.

When the internal combustion engine 2 operates, the air flowing from the air cleaner 14 through the first intake passage 4-1 and the float chamber of the carburetor 10
The mixture with fuel from 34 is pressurized by the supercharger 8 and supplied to the internal combustion engine 2 via the second intake passage 4-2.

When the boost pressure in the second intake passage 4-2 becomes higher than a predetermined value, the boost pressure control valve 22 causes the first bypass passage 18-
1 operates to connect the second bypass passage 18-2 with each other, and recirculates the air-fuel mixture pressurized from the second intake passage 4-2 side to the first intake passage 4-1 side.

At this time, the pressurized air-fuel mixture becomes high in temperature, and the first and second
Since the PCV valve 30 provided in the second bypass passage 18-2 is heated because it flows through the bypass passages 18-1 and 18-2, it is possible to prevent the inconvenience that the PCV valve 30 freezes. The function of the PCV valve 30 can be satisfactorily secured.

Further, when water in the blow-by gas is present in the PCV valve 30, the water can be smoothly scavenged by the mixed airflow flowing out from the supercharging pressure control valve 22, and the water can be converted into water droplets to some extent. Therefore, it is possible to prevent the internal combustion engine 2 from being adversely affected.

Furthermore, when the outlet 32 of the second bypass passage 18-2 is provided so as to be directed to the supercharger 8 side, the water discharged from the PCV valve 30 does not easily flow to the carburetor 10 side, Vaporizer 10
There is no inconvenience such as the intake throttle valve 12 being frozen.

Furthermore, as shown in FIG. 3, the second bypass passage 18-2
If the water reservoir 26 is formed in the bottom portion 24a of the passage wall 24 forming the recess, the water retained in the water reservoir 26 can be discharged at once when the supercharging pressure becomes high. The scavenging of water can be effectively performed.

As a result, the water in the blow-by gas can be discharged without adversely affecting the operation of the internal combustion engine 2, and the operation of the internal combustion engine 2 can be satisfactorily secured.

Further, since the PCV valve 30 can be heated by the high temperature air-fuel mixture, there is no need to install the PCV valve 30 on the intake passage 4, the installation is simple, and the PCV valve 30 freezes for a long time. Can be solved at low cost.

[Effect of device]

As is clear from the above detailed description, according to the present invention,
A supercharging pressure control valve that controls the supercharging pressure in the intake passage on the downstream side of the supercharger is provided in the middle of the bypass passage, and blow-by gas is blown into the bypass passage communicating from the supercharging pressure control valve to the intake passage on the upstream side of the supercharger. By providing the PCV valve of the reflux mechanism, it is possible to prevent the PCV valve from freezing to fully exhibit the function of the PCV valve and to prevent the moisture in the blow-by gas from adversely affecting the operation of the internal combustion engine. Moreover, the structure can be simplified and the cost can be reduced.

[Brief description of drawings]

FIGS. 1 to 3 show an embodiment of the present invention, FIGS. 1 and 2 are schematic views of a supercharging device for a vehicle, and FIG. 3 is a schematic sectional view of a portion to which a PCV valve is attached. FIG. 4 is a schematic view of a conventional blow-by gas recirculation device. In the figure, 2 is an internal combustion engine, 4 is an intake passage, 8 is a supercharger, 10 is a carburetor, 18 is a bypass passage, 22 is a supercharging pressure control valve, 26 is a water reservoir, 28 is a blowby gas recirculation mechanism, 30
Is a PCV valve, 32 is an outlet, and 36 is a leak passage.

Claims (1)

[Scope of utility model registration request] 1. A supercharging device for controlling a supercharging pressure in the intake passage downstream of the supercharger, wherein a bypass passage communicating between the upstream side and the downstream side of the supercharger of the intake passage is provided. A supercharging device for a vehicle, wherein a pressure control valve is provided, and a PCV valve of a blow-by gas recirculation mechanism is provided in the bypass passage communicating from the supercharging pressure control valve to the intake passage on the upstream side of the supercharger. .