JP3596255B2 - Freezing prevention structure for negative pressure take-out part in intake manifold - Google Patents

Description

[0001]
TECHNICAL 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 having a negative pressure take-out portion, and more particularly to a freeze prevention structure of a negative pressure take-out portion.
[0002]
[Prior art]
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 that the internal combustion engine takes in per cycle is substantially proportional to the absolute pressure in the intake manifold. In such a type of fuel injection device, 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, in cold weather such as winter, when the temperature around the negative pressure take-out part is extremely low and the air in the intake manifold is humid, the moisture contained in the air condenses, It freezes at the negative pressure outlet. Therefore, there is a disadvantage that the pressure sensor cannot detect an accurate intake pipe pressure, so that an appropriate air-fuel ratio cannot be secured, and the driving performance deteriorates.
[0004]
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 to prevent freezing of the pressure guiding tube, as disclosed in Japanese Utility Model Application Laid-Open No. 63-121734. An antifreezing device for a pressure sensor has been proposed.
[0005]
[Problems to be solved by the invention]
However, in the above-described freeze prevention device for the pressure sensor, a heating device must be separately provided, and there is a problem that the number of components increases and the number of assembling steps 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.
[0006]
The present invention has been made in view of such circumstances, and has as its object to prevent freezing of a negative pressure take-out part in an intake manifold that can prevent freezing of a negative pressure take-out part without changing the intake pipe pressure. It is to provide structure.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 is provided with a plurality of distribution pipes for introducing air into an internal combustion engine mounted such that the cylinders are arranged in the vehicle traveling direction, and a resin-made vehicle having a negative pressure take-out portion . In the intake manifold, while providing a shielding member that shields the traveling wind from the vehicle traveling direction toward the negative pressure take-out part, the rearmost distribution pipe in the traveling direction of the vehicle projects more rearward in the traveling direction than the shielding member. By forming, the last distribution pipe and the shielding member form an air stagnation portion, and a negative pressure take-out portion is provided in the stagnation portion on the rear side in the vehicle traveling direction of the shielding member. The gist of the invention is that the air connector is formed integrally with the pipe and connects the throttle body and the surge tank .
[0008]
According to this configuration, a portion that can stagnate the air is formed by the distribution pipe and the shielding member at the rearmost portion of the intake manifold, and it is possible to prevent cold air from hitting the negative pressure extracting portion when the vehicle travels in winter or the like. , Freezing is prevented. Further, since the negative pressure take-out section is not heated, the pressure in the intake pipe is not changed.
[0010]
Further , it is not necessary to separately provide a shielding member, and cost increase is suppressed.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment in which the present invention is embodied in a resin intake manifold will be described with reference to the drawings.
[0012]
FIG. 1 shows an intake manifold 1 according to the present embodiment. The intake manifold 1 is formed of a thermoplastic resin for use in a six-cylinder engine as an internal combustion engine, and includes a mounting plate 2, an air connector 3, a surge tank 4, distribution pipes 5A, 5B, 5C, 5D, 5E, 5F and an intake port plate 6 are provided.
[0013]
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 to a surge connector via an air connector 3 having a cylindrical shape. It is connected to the tank 4. Six distribution pipes 5A, 5B, 5C, 5D, 5E, 5F are connected to the surge tank 4.
[0014]
The end of each distribution pipe 5A, 5B, 5C, 5D, 5E, 5F is connected to an intake port plate 6 having intake ports 7 (FIG. 2) arranged at substantially equal intervals. The intake port plate 6 is connected to a combustion chamber (not shown) of the engine via an intake port (not shown).
[0015]
Therefore, the air taken in from the outside air intake (not shown) provided in the vehicle is guided to the surge tank 4 through the air connector 3 from the air cleaner, the throttle body and the like. 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).
[0016]
The distribution pipes 5A, 5B, 5C and the distribution pipes 5D, 5E, 5F are formed symmetrically in the traveling direction of the vehicle. The distribution pipe 5A is at the head in the vehicle traveling direction, and the distribution pipe 5F is at the rear 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 stagnant portion that can stagnate air is formed by the distribution pipe 5F and the abdomen 3A of the air connector 3.
[0017]
In the staying portion, a negative pressure extracting portion 10 for a sensor and a negative pressure extracting portion 11 for a brake boost are formed on the abdomen 3A of the air connector 3. 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.
[0018]
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 protrude rearward in the traveling direction of the vehicle in the traveling direction of the vehicle, and a stagnant 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. For this reason, it is possible to prevent cold air from hitting the negative pressure extracting portions 10 and 11, the pressure guiding tube 12, and the pressure sensor 13 during running of the vehicle in winter or the like, thereby preventing freezing.
[0019]
Also, since it is not necessary 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. Can be detected, so that an appropriate air-fuel ratio can be secured, and the driving performance can be improved.
[0020]
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 manifold 3 is integrally formed with the air connector 3 as a shielding member, it is not necessary to separately provide a shielding member, thereby suppressing an increase in cost.
[0021]
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.
[0023]
【The invention's effect】
As described in detail above, according to the first aspect of the present invention, it is possible to prevent the negative pressure extracting portion from freezing without changing the intake pipe pressure.
[0024]
Further , it is not necessary to separately provide a shielding member, so that cost increase can be suppressed.
[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;
3 ... air connector as shielding member, 5A, 5B, 5C, 5D, 5E, 5F ... distribution pipe, 10, 11 ... negative pressure take-out part.

Claims (1)

A plurality of distribution pipes for introducing air to an internal combustion engine mounted such that the cylinders are lined up in the vehicle traveling direction, and a resin intake manifold for a vehicle having a negative pressure take-out unit,
A shielding member for shielding traveling wind from the vehicle traveling direction toward the negative pressure take-out portion is provided, and a rearmost distribution pipe in the traveling direction of the vehicle is formed to protrude more rearward than the shielding member in the traveling direction. Thereby, a stagnant portion of air is formed by the rearmost distribution pipe and the shielding member, and the negative pressure take-out portion is provided in the stagnation portion on the rear side in the vehicle traveling direction of the shielding member ,
The above-mentioned shielding member is formed integrally with the above-mentioned distribution pipe, and is a freeze prevention structure of a negative pressure take-out part in an intake manifold which is an air connector which connects a throttle body and a surge tank .

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