JPH11141419A - Freezing preventing structure of negative pressure take-out part in intake manifold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the freezing of a negative pressure take-out part without changing the pressure of an intake pipe. SOLUTION: A mounting plate 2 connected to the upstream parts of an intake passage is connected to a surge tank 4 through a cylindrical air connector 3. Distribution pipes 5A, 5B, 5C, 5D, 5E, 5F are connected to the surge tank 4, and each terminal part of each distribution pipe is connected to an intake port plate 6. The intake port plate 6 is connected to the combustion chamber of an engine through an intake port. The backmost distribution pipe 5F in a direction that a vehicle travels is formed by being projected to the rear of the direction that the vehicle travels so as to be projected further than the belly part 3A of the air connector 3, and a remaining part is formed by the distribution pipe 5F and the belly part 3A of the air connector 3. In the remaining part, negative pressure take-out parts 10, 11 are formed in the belly part 3A, and the negative pressure removing part 10 is connected to a presser sensor 13 through a connecting pipe 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake manifold for a vehicle having a plurality of distribution pipes for introducing air into an internal combustion engine and a negative pressure take-out portion, and more particularly to a negative pressure take-out portion. To a freezing prevention structure.

[0002]

2. Description of the Related Art In recent years, some internal combustion engines of vehicles are equipped with an electronically controlled fuel injection device as a countermeasure against problems such as harmful exhaust components and fuel consumption rate. Among the electronically controlled fuel injection devices, there is a type that utilizes the fact that the amount of air sucked per cycle by the internal combustion engine is substantially proportional to the absolute pressure in the intake manifold. In the fuel injection device of this type, a negative pressure extracting portion is provided in the intake manifold to guide the intake pipe pressure to a pressure sensor.

[0003] By the way, when the temperature around the negative pressure take-out portion is extremely low in cold weather such as winter, and when the air in the intake manifold is humid, moisture contained in the air condenses and this dew condensation occurs. Moisture is frozen at the negative pressure outlet. Therefore, there is a disadvantage that the pressure sensor cannot accurately detect the intake pipe pressure, so that an appropriate air-fuel ratio cannot be secured, and the driving performance deteriorates.

In order to solve the above-mentioned problem, a heating mechanism is provided for a pressure guiding tube for guiding an intake pipe pressure to a pressure sensor, as disclosed in Japanese Utility Model Laid-Open No. 63-121732.
A freezing prevention device for a pressure sensor that prevents freezing of a pressure guiding tube has been proposed.

[0005]

However, in the above-described freeze prevention device for the pressure sensor, a heating device must be provided separately, and there is a problem that the number of parts increases and the number of assembling steps also increases. Further, since the gas guided to the pressure sensor is heated by the heating mechanism, the gas expands, and it is not possible to detect an accurate pressure of the gas, and thus it is impossible to secure an appropriate air-fuel ratio.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a negative pressure extraction unit in an intake manifold which can prevent freezing of a negative pressure extraction unit without changing the intake pipe pressure. To provide an antifreezing structure.

[0007]

According to a first aspect of the present invention, there is provided an intake manifold for a vehicle having a plurality of distribution pipes for introducing air into an internal combustion engine and a negative pressure take-out portion. In the advancing direction, while forming the rearmost distribution pipe so as to protrude backward in the traveling direction, a shielding member is provided on the rearmost distribution pipe,
The gist of the invention is that a negative pressure extracting portion is provided on the rear side of the shielding member in the vehicle traveling direction.

[0008] According to this structure, a portion capable of holding air is formed by the distribution pipe and the shielding member at the rearmost portion of the intake manifold, so that cold air hits the negative pressure take-out portion during running of the vehicle in winter or the like. Is prevented,
Freezing is prevented. In addition, since the negative pressure outlet is not heated, the intake pipe pressure does not change.

According to a second aspect of the present invention, in the anti-freezing structure of the negative pressure take-out portion of the intake manifold according to the first aspect, the intake manifold is made of a resin material, and the shielding member is formed integrally with the distribution pipe. The gist is that it is an air connector.

[0010] According to this configuration, there is no need to separately provide a shielding member, and an increase in cost is suppressed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a resin intake manifold will be described below with reference to the drawings.

FIG. 1 shows an intake manifold 1 according to this embodiment. This intake manifold 1
It is molded from a thermoplastic resin for a six-cylinder engine as an internal combustion engine, and has a mounting plate 2, an air connector 3, a surge tank 4, and distribution pipes 5A, 5B, 5C, 5
D, 5E, 5F and an intake port plate 6.

The mounting plate 2 is a portion connected to an upstream part (not shown) of an intake passage such as a throttle body on which a throttle valve is pivotally supported. The mounting plate 2 is connected via an air connector 3 having a cylindrical shape. And surge tank 4
It is connected to the. Six distribution pipes 5 for surge tank 4
A, 5B, 5C, 5D, 5E, 5F are connected.

Each distribution pipe 5A, 5B, 5C, 5D, 5E,
At the end of 5F, intake ports 7 arranged at approximately equal intervals
It is connected to the intake port plate 6 having (FIG. 2). The intake port plate 6 is connected to a combustion chamber (not shown) of the engine via an intake port (not shown).

Accordingly, air taken in from an outside air intake (not shown) provided in the vehicle is guided from an air cleaner, a throttle body, or the like to the surge tank 4 through the air connector 3. The air introduced into the surge tank 4 is sent from the distribution pipes 5A, 5B, 5C, 5D, 5E, 5F to each combustion chamber (not shown).

The distribution pipes 5A, 5B, 5C and the distribution pipes 5D, 5D
E and 5F are formed symmetrically in the traveling direction of the vehicle. The distribution pipe 5A is at the head in the vehicle traveling direction,
The distribution pipe 5F is the last in the vehicle traveling direction. The distribution pipe 5A is formed to protrude forward in the vehicle traveling direction. The distribution pipe 5F is formed to protrude rearward in the vehicle traveling direction so as to protrude beyond the abdomen 3A of the air connector 3 as a shielding member. Therefore, a stagnation portion that can stagnate the air is formed by the distribution pipe 5F and the abdomen 3A of the air connector 3.

Then, the air connector 3
In the abdomen 3A, a negative pressure extracting portion 10 for a sensor and a negative pressure extracting portion 11 for a brake boost are formed. The negative pressure extracting unit 10 is connected to a pressure sensor 13 fixed on a mounting unit 14 via a pressure guiding tube 12.

As described above, according to the resin intake manifold of the present embodiment configured as described above, the following effects can be obtained. In the intake manifold 1 of the present embodiment, the rearmost distribution pipe 5F is formed so as to project rearward in the traveling direction of the vehicle in the traveling direction of the vehicle, and a stagnation portion for restraining air with the abdomen 3A of the air connector 3 is formed. . In the stagnant portion, negative pressure extracting portions 10 and 11 were formed in the abdomen 3A of the air connector 3, and a pressure guiding tube 12 and a pressure sensor 13 were provided in the stagnant portion. Therefore, when the vehicle travels in winter or the like, the negative pressure extraction units 10 and 11 and the pressure guiding pipe 12
Further, it is possible to prevent cold air from hitting the pressure sensor 13 and prevent freezing.

Since there is no need to provide a heating mechanism in the pressure guiding tube 12, the air guided to the pressure sensor 13 does not expand, and the pressure in the intake manifold 1 does not change. Accurate pressure can be detected, so that an appropriate air-fuel ratio can be secured, and driving performance can be improved.

Further, since it is not necessary to provide a heating mechanism in the pressure guiding tube 12, an increase in the number of parts and an increase in the number of assembling steps can be suppressed. In addition, in the present embodiment, since the air intake connector 3 as a shielding member is implemented in the resin intake manifold 1 integrally formed, it is not necessary to separately provide a shielding member, and it is possible to suppress an increase in cost.

The above embodiment may be modified as follows, and the same operation and effect can be obtained in such a case. In the above embodiment, the embodiment is embodied as the intake manifold 1 for six cylinders, but may be embodied as an intake manifold corresponding to an arbitrary number of cylinders.

In the above embodiment, the resin intake manifold 1 in which the air connector 3 is integrally formed is embodied, but the resin or metal intake manifold in which the air connector is formed separately may be embodied. In this case, for example, a shielding plate may be provided in the distribution pipe as a shielding member.

[0023]

As described above in detail, according to the first aspect of the present invention, freezing of the negative pressure extracting portion can be prevented without changing the intake pipe pressure.

According to the invention described in claim 2, according to claim 1,
In addition to the effects of the present invention, it is not necessary to separately provide a shielding member, and it is possible to suppress an increase in cost.

[Brief description of the drawings]

FIG. 1 is a plan view of a resin intake manifold according to an embodiment.

FIG. 2 is a bottom view of the same resin intake manifold.

FIG. 3 is a side view of the same resin intake manifold.

[Explanation of symbols]

3. Air connector as shielding member, 5A, 5B, 5
C, 5D, 5E, 5F ... distribution pipes, 10, 11 ... negative pressure outlets.

Claims (2)

[Claims] 1. An intake manifold for a vehicle having a plurality of distribution pipes for introducing air into an internal combustion engine and having a negative pressure take-out portion, wherein a rearmost distribution pipe in a traveling direction of the vehicle is moved in the traveling direction. And a shielding member is provided on the rearmost distribution pipe, and a negative pressure extracting portion of the intake manifold provided with the negative pressure extracting portion on the rear side in the vehicle traveling direction of the shielding member. Anti-freeze structure. 2. The structure for preventing freezing of a negative pressure take-out part in an intake manifold according to claim 1, wherein the intake manifold is made of a resin material, and the shielding member is an air connector formed integrally with the distribution pipe.