JPH0640344U - Intake manifold - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an intake manifold that prevents fuel from entering the exhaust gas circulation passage of an exhaust gas recirculation device formed in the intake manifold. [Structure] First connected to a vaporizer for atomizing fuel
A carburetor mounting portion 9 having a port 11 and a second port 12 formed therein, an intake port 10 communicating with the first and second ports 11 and 12 and a cylinder, and an intake port near the carburetor mounting portion 9. The exhaust gas recirculation passage 8 of the exhaust gas recirculation device 6 whose opening communicates with the opening 10, and the portion of the intake port 10 above the opening A that faces the opening A at the peripheral portion of the second port 12. , Exhaust port 10 and opening A
A partition wall 15 that separates the two is formed.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an intake manifold for an engine having a carburetor as a fuel supply device and having an exhaust gas recirculation device.

[0002]

[Prior art]

 A carburetor that is a carburetor is used as a fuel supply device, and in an engine having an exhaust gas recirculation device, a carburetor is attached to an intake manifold that communicates with a cylinder. Then, fuel is injected from this carburetor to generate an air-fuel mixture, and the generated air-fuel mixture is distributed substantially evenly in the cylinders. Further, the exhaust gas recirculation path (EGR flow path) of the exhaust gas recirculation device is integrally formed in this intake manifold near the intake port connected to each cylinder and the carburetor mounting portion so that one end thereof is opened. . That is, it is arranged above the intake port.

In the intake manifold having such a structure, a projecting wall called a “sag wall” is formed in the vicinity of the opening of the EGR passage to prevent the injected fuel from directly flowing into the EGR passage. There is.

[0004]

[Problems to be solved by the device]

 In the structure of the intake manifold described above, since the protruding wall is formed at the opening of the EGR passage, it is possible to prevent the fuel from directly flowing into the EGR passage by this protruding wall, but it is possible to prevent the fuel from adhering to the inner wall of the intake manifold. The fuel in the intake manifold becomes liquid and the fuel is rolled up due to the pressure change, and the rolled-up fuel enters the EGR passage and accumulates in the same passage.

When the exhaust gas recirculation device (EGR) operates with the fuel accumulated in the EGR passage, the fuel accumulated with the exhaust gas flowing in the exhaust gas circulation passage (EGR passage) moves to the intake port side. Since it will be injected, there is a risk of causing engine stall in the worst case due to temporary excess fuel.

[0006]

[Means for Solving the Problems]

 Therefore, in the intake manifold of the present invention, a carburetor mounting portion formed with a first port and a second port connected to a carburetor that atomizes fuel and sends it to the cylinder of the engine, and the first and second ports described above. An exhaust port that communicates with the intake port that communicates with the cylinder via an intake valve, and an opening that communicates with the intake port near the carburetor mounting part that exhaustively recirculates the exhaust gas of the engine to the intake side. The exhaust gas circulation passage of the gas recirculation device is provided, and the exhaust port and the above-mentioned exhaust port are provided in a portion of the intake port above the opening, the portion being opposed to the opening at the peripheral portion of the second port. A partition wall separating the opening was formed.

[0007]

[Action]

 Peripheral portion of the second port located in the intake port above the opening of the exhaust gas circulation path of the exhaust gas recirculation device that communicates with the intake port near the carburetor mounting portion Since the partition wall that separates the exhaust port and the opening is formed, even if the fuel directly injected from the carburetor and the liquid fuel that remains in the exhaust manifold roll up, the exhaust gas circulation path for that fuel Invasion into the area is blocked.

[0008]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. In FIG. 2, reference numeral 1 indicates a four-cylinder engine (hereinafter referred to as "engine"). The engine 1 is provided with an intake manifold 3 that guides the air-fuel mixture to the cylinder 2 on the intake side, and an exhaust manifold 5 that guides the exhaust gas G to the exhaust pipe 4 on the exhaust side. The engine 1 is equipped with an exhaust gas recirculation device 6 (hereinafter referred to as “EGR device 6”) that recirculates exhaust gas to the intake manifold 3 to suppress the production of nitrogen oxides.

The EGR device 6 includes a bypass passage 4 a connected to the exhaust pipe 4 and an exhaust gas circulation passage 8 (hereinafter referred to as “EGR passage 8” formed in the intake manifold 3 and connected to the bypass passage 4 a via an EGR valve 7). And a portion of the exhaust gas G is supplied to the intake manifold 3 by operating the EGR valve 7 in a timely manner.

The intake manifold 3 has a carburetor (not shown), which is a carburetor for vaporizing fuel, and a mounting portion 9, an intake port 10 communicating with the cylinder 2 via an intake valve (not shown), an intake port 10 and an EGR valve. EGR passages 8 communicating with 7 are formed integrally with the manifold 3. Further, the exhaust manifold 3 is provided with the manifold 3 and a cooling system thermostat 13 for cooling the engine 1.

The mounting portion 9 is arranged at a gathering portion of the intake ports 10, and has a first port 11 and a second port 12 which are respectively connected to a medium-low barrel and a medium-high speed barrel of a carburetor (not shown). It is formed so as to open from the seat surface 9a. The first and second ports 11 and 12 communicate with the intake port 10 as shown in FIG.

A cooling water passage 14 connected to a cooling system via a thermostat 13 is formed on the outer surface of the intake port 10 to cool the air-fuel mixture passing through the intake port 10 and mix it into the cylinder 2. The efficiency of filling air is improved.

As shown in FIG. 1, a flange portion 8b is formed at one end 8a of the EGR passage 8 and is connected to the EGR valve 7 shown in FIG. 1, and the other end 8b is provided at the exhaust port 10b. An opening A is provided at the collecting portion of the above and is connected, and the opening A communicates with the intake port 10. The opening position of the opening A is below the second port 12.

In the intake port 10 located above the opening A of the EGR flow path 8, as shown in FIGS. 3 and 4, the partition wall 15 faces the opening A at the peripheral portion of the second port 12. It is located at the position where The partition wall 15 is formed with a width reaching from the inner wall surface 10a of the exhaust port 10 to the inner end 12a of the second port 12, and has a structure for partitioning the second port 12 and the opening portion A.

In the intake manifold 3 thus configured, when the engine 1 is started and fuel is sprayed from a carburetor (not shown), the fuel is mixed with air to form an air-fuel mixture. At this time, the injected fuel is repelled by the partition wall 15 and cannot directly enter the EGR flow path 8. The generated air-fuel mixture is sucked into the cylinder by a negative pressure in the cylinder 2 when the intake valve (not shown) is opened during the engine intake stroke and is burned.

The burned air-fuel mixture becomes exhaust gas G and is exhausted into the atmosphere through the exhaust manifold port 5 through the exhaust pipe 4 in the engine exhaust process. Further, at this time, when the EGR valve 7 operates, part of the exhaust gas G flows into the EGR passage 8 from the bypass passage 4a via the valve 7. As shown in FIG. 4, the inflowing exhaust gas G flows from the intake port 10 into the cylinder 2 after being mixed with the air-fuel mixture generated by reaching the inside of the intake port 10 through the opening A of the other end 8b of the flow path. go. At this time, since the fuel injected from the carburetor is not accumulated in the EGR passage 8, the air-fuel mixture sent to the cylinder 2 does not become excessive in fuel.

Further, even if the pressure inside the intake manifold 3 changes due to opening and closing of a throttle valve (not shown), and the fuel that adheres to the inner wall of the intake manifold 3 and becomes liquid and flows through the wall surface is rolled up, the partition wall 15 Since the opening A is partitioned by the above, it is possible to prevent the fuel from entering the EGR passage 8.

Further, since the partition wall 15 allows the fuel to flow into the EGR passage 8 from the opening A of the EGR passage 8, the EGR passage 8 can be arranged below the intake port 10, and the EGR passage 8 can be arranged below the intake port 10. The degree of freedom in designing the arrangement of the flow path 8 increases.

[0019]

[Effect of device]

 As described above, according to the present invention, it is possible to prevent the fuel from entering the exhaust gas circulation passage from the inside of the intake manifold. Can be prevented.

[Brief description of drawings]

FIG. 1 is a plan view showing an intake manifold according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of an engine in which the intake manifold shown in FIG. 1 is used.

3 is a cross-sectional view of the intake manifold shown in FIG.

FIG. 4 is a partially enlarged view of an exhaust gas circulation path and a partition wall, which are essential parts of the present invention.

[Explanation of symbols]

 1 Engine 2 Cylinder 3 Intake Manifold 6 Exhaust Gas Recirculation Device 8 Exhaust Gas Circulation Path 9 Vaporizer Attachment 10 Intake Port 10a Exhaust Port Inner Wall Surface 11 First Port 12 Second Port 12a Second Port Inner End 15 Partition Wall A Aperture

Claims (1)

[Scope of utility model registration request] 1. A carburetor mounting portion having a first port and a second port connected to a carburetor for atomizing fuel into an engine cylinder and communicating with the first and second ports. Exhaust gas from an exhaust gas recirculation device that recirculates the exhaust gas of the engine to the intake side in a timely manner and the intake port that communicates with the cylinder via an intake valve and the opening of the intake port that communicates with the intake port near the carburetor mounting portion An intake manifold having a gas circulation path, wherein the exhaust port and the opening are provided in a portion of the intake port above the opening that faces the opening in a peripheral portion of the second port. An intake manifold characterized by the formation of partition walls.