JP4574360B2 - Intake manifold - Google Patents

Description

  The present invention relates to an intake manifold of an engine.

Conventionally, for example, as disclosed in Patent Document 1, a PCV valve provided at the outlet of a gas-liquid separation part of a rocker cover and an intake manifold are connected by a hose, and blow-by gas from the engine side is connected to the PCV valve. There is an engine that is configured to lead the intake manifold through a hose and re-burn the blow-by gas in the engine.
JP-A-8-93436

  In the conventional configuration described above, the hose is connected to the intake manifold to circulate the blow-by gas. Therefore, the hose is an engine external pipe. Therefore, the blow-by gas is cooled in a low temperature region such as a cold region, and the blow-by gas is cooled. There is a problem that oil and moisture in the gas may freeze and block the blow-by gas passage, and there is a problem that the number of parts increases, the assembly work becomes complicated and the production cost increases. It was.

The present invention has been devised in view of the above-described conventional problems, and is an intake manifold that can prevent freezing of oil and moisture in blow-by gas, reduce the number of parts, and eliminate the complexity of assembly work. According to a first aspect of the present invention, a blow-by gas passage through which blow-by gas passes is formed in a support member that is integrally formed with the intake manifold and is attached to and supported by the engine. And an intake manifold provided with a through-hole that communicates and connects the intake passage formed in the intake manifold ,
The intake manifold has a throttle body mounting portion for mounting a throttle body,
The throttle body mounting portion is formed with a cooling water passage for circulating engine cooling water to prevent freezing of the throttle valve in the throttle body.
The support member is integrally formed with the throttle body mounting portion,
A through hole that connects the blow-by gas passage and the intake passage is formed in the vicinity of the cooling water passage .

According to a second aspect of the present invention, the through hole is formed to open at a right angle to the intake passage so that the blow-by gas is blown from a direction perpendicular to the flow direction of the intake air flowing through the intake passage. That is.

According to a third aspect of the present invention, the through hole is formed to open in parallel with the intake passage so that the blow-by gas is blown out along a flow direction of the intake air flowing through the intake passage.

  According to a fourth aspect of the present invention, the support member is formed in a covered cylindrical shape with the lower side open, and is attached to the rocker cover with a bolt, and the seat surface on the outer periphery of the lower end contacting the rocker cover is screwed into the bolt. The bolt holes are set at substantially the same distance with the bolt hole as the center.

In the present invention, a blow-by gas passage through which blow-by gas passes is formed in a support member that is integrally formed with the intake manifold and is attached to and supported by the engine, and is formed in the blow-by gas passage and the intake manifold. An intake manifold provided with a through-hole communicating with the intake passage ,
The intake manifold has a throttle body mounting portion for mounting a throttle body,
The throttle body mounting portion is formed with a cooling water passage for circulating engine cooling water to prevent freezing of the throttle valve in the throttle body.
The support member is integrally formed with the throttle body mounting portion,
By forming a through hole that connects the blow-by gas passage and the intake passage in the vicinity of the cooling water passage, no external piping such as a conventional hose is required, reducing the number of parts and assembling. Work complexity can be eliminated, and blow-by gas can be passed through the intake passage by effectively using the inside of the support member.
In addition, the cooling water passage circulates the cooling water warmed by cooling the engine, so that the heat of the cooling water is transmitted from the cooling passage to the through-hole provided nearby, and the blow-by gas passage is warmed, Oil and moisture in blow-by gas will not freeze in a low temperature region such as in a cold region.

The through hole is formed so as to open at a right angle to the intake passage so that the blow-by gas is blown out from a direction perpendicular to the flow direction of the intake air flowing through the intake passage. By returning blow-by gas at right angles to the flow of intake air flowing through the passage, the intake air and blow-by gas mix well in the intake manifold, and the blow-by gas can be returned evenly to each branch pipe of the intake manifold It becomes.

The through hole is formed so as to open in parallel with the intake passage so that the blow-by gas is blown out along the flow direction of the intake air flowing through the intake passage. By returning the blow-by gas toward the downstream in parallel with the flow, the upstream throttle valve is not contaminated by the blow-by gas even when the intake air is blown back to the upstream side.

  Further, the support member is formed in a covered cylindrical shape with the lower side open, and is attached to the rocker cover with a bolt, and the seat surface on the outer periphery of the lower end that comes into contact with the rocker cover is substantially centered around the bolt hole into which the bolt is screwed. By setting the same distance, the frictional force acts evenly on the entire circumference of the lower end seating surface of the support member and the contact surface of the rocker cover, and the bolt does not loosen due to engine vibration or the like. Can be stably attached to the rocker cover.

Embodiments of the present invention will be described below with reference to the drawings.
As shown schematically in FIG. 1, the internal combustion engine cooling system includes a radiator 20, a water pump 22, a cylinder block 23, a cylinder head 1, an outlet 24, and the like.
In the figure, the cooling water cooled by the radiator 20 flows into the water pump 22 through the thermostat 21 and is pumped from the water pump 22 into the cylinder block 23 and the water jacket of the cylinder head 1. 1 is cooled.

  Cooling water (hot water) whose temperature has been increased by cooling the cylinder block 23 and the cylinder head 1 returns to the radiator 20 through the outlet 24 and is cooled again by the heat radiation action of the radiator 20. Further, the cylinder block 23 and the cylinder head 1 are cooled, and a part of the cooling water (hot water) whose water temperature has risen is configured to be supplied from the outlet 24 to the throttle body mounting portion 7 and the heater core 25. .

FIG. 2 is a schematic perspective view of an intake manifold attached to the engine.
In the figure, a rocker cover 2 is provided on the upper surface of a cylinder head 1 constituting the engine, and an intake manifold 4 is attached to the upper surface of the rocker cover 2 with bolts using a plurality of support members 3 and 3. ing.

  In this intake manifold 4, a surge tank 5 and four branch pipes 6, 6, 6, 6 extending from the surge tank 5 are integrally formed of resin, and a throttle valve (not shown) is disposed upstream of the surge tank 5. A throttle body mounting portion 7 is provided for mounting a throttle body with a lid. A cylindrical support member 8 with a lid is formed integrally with the throttle body mounting portion 7. In addition, a seat bolt 9 is inserted from above, the seat bolt 9 is fastened to the rocker cover 2, and the support member 8 is attached to and supported by the rocker cover 2.

FIG. 3 shows an enlarged cross-sectional configuration view of the support member 8 and the throttle body mounting portion 7 as viewed from the right side, and FIG. FIG. 3 is also a cross-sectional view taken along line AA in FIG.
As shown in the figure, the throttle body attaching portion 7 is provided with a cooling water passage 10 for circulating engine cooling water in order to prevent the freezing of the throttle valve in the attached throttle body.
An intake passage R that communicates from the throttle body mounting portion 7 to the surge tank 5 and sucks intake air is formed inside, and is opened to communicate with the intake passage R in a direction perpendicular to the blow-by gas passage 15 (through). Hole) is formed penetrating from the support member 8 side to the throttle body mounting portion 7 side.

In order to allow the blow-by gas passage 15 (through hole) to penetrate from the side surface side of the support member 8, a blind plug 16 is fitted in the hole formed in the support member 8 and closed.
The blow-by gas passage 15 is formed in the vicinity of the cooling water passage 10 described above, and the cooling water heated by cooling the engine is circulated through the cooling water passage 10 to cool the heat of the cooling water. It is transmitted from the water passage 10 to the throttle body mounting portion 7 so that the entire throttle body mounting portion 7 is warmed, and the entire throttle body mounting portion 7 is warmed so that the blow-by gas passage 15 is also warmed. The oil and moisture in the blow-by gas blown into the intake passage R through the blow-by gas passage 15 in a low temperature range such as in the case of being freezing.

The support member 8 integrated with the throttle body mounting portion 7 is formed in a covered cylindrical shape with the lower end opened, and an O-ring 11 is fitted on the seating surface on the outer periphery of the lower end, and the O-ring 11 is interposed. Thus, the seating surface on the outer periphery of the lower end of the support member 8 is attached in contact with the upper surface of the rocker cover 2.
That is, the seat bolt 9 is inserted into the center from the upper surface side of the support member 8, the lower end of the seat bolt 9 is screwed into the bolt hole 2 a formed in the rocker cover 2, and the seat bolt 9 is tightened. As a result, the support member 8 is fixed on the rocker cover 2.

  In addition, it is set so that the seat surface of the lower end outer periphery of the supporting member 8 may be located on a substantially concentric circle centering on the bolt hole 2a. That is, the seat surface on the outer periphery of the lower end of the support member 8 is set to have substantially the same distance with the bolt hole 2a as the center, and one support bolt 9 is tightened to place the support member 8 on the rocker cover 2. When mounted and fixed, it is configured so that a frictional force acts evenly on the contact surface between the rocker cover 2 and the entire circumference of the seating surface at the outer periphery of the lower end of the support member 8. The seated bolt 9 is configured so that no load is applied to the seated bolt 9 in the rotational direction or shearing direction, and the seated bolt 9 is not loosened.

  In addition, the shape of the support member 8 is not limited to a covered cylindrical shape, and may be formed in a covered rectangular tube shape whose lower end is opened. Similarly, the distance from the bolt hole 2a to the seating surface on the outer periphery of the lower end is set to be substantially the same, and the looseness of the bolt 9 with the seat can be prevented.

In the state where the support member 8 is mounted on the rocker cover 2, a blowby gas passage space 8a through which blowby gas can pass is formed in the support member 8, and the blowby gas passage space 8a is formed in the blowby gas passage space 8a. The PCV valve 12 provided on the rocker cover 2 is arranged.
The blow-by gas that has passed through the gas-liquid separation passage 14 constituted by the rocker cover 2 and the baffle plate 13 below the PCV valve 12 is guided through the PCV valve 12 into the blow-by gas passage space 8a. .

In the gas-liquid separation passage 14, the blow-by gas (unburned gas) generated in the crankcase of the engine contains engine oil such as mist, so that the blow-by gas containing oil enters the throttle body. In order to prevent adhesion, it is provided for separating the oil of blow-by gas.
Further, the PCV valve 12 is blow-by because the engine rotation becomes unstable if the intake manifold 4 is sucked into the intake manifold 4 more than necessary when idling or decelerating in the intake manifold 4 where the throttle valve is closed. It is provided to limit the maximum gas flow rate.

  In this example, the blow-by gas leaking little by little from the gap between the piston or piston ring of the engine and the cylinder is introduced into the blow-by gas passage space 8a in the support member 8 through the gas-liquid separation passage 14 and the PCV valve 12, and further blow-by gas is supplied. The blow-by gas is introduced into the intake passage R through the gas passage 15, and the intake air and the blow-by gas sucked in the intake passage R are mixed, and the blow-by gas is recombusted in the engine. Since the blow-by gas passage 15 is opened at a right angle to the intake passage R so that the blow-by gas is blown from a direction perpendicular to the flow direction of the intake air flowing through the intake passage R, the blow-by gas can be satisfactorily taken into the intake air. It can be mixed.

  In addition, in the structure of this example, the hose etc. which let blow-by gas pass through conventionally are unnecessary, the number of parts can be reduced, and blow-by gas can be passed by utilizing the inside of the support member 8 effectively. By simply attaching the support member 8, a circulation path of blow-by gas can be formed, the assembling work and the like can be facilitated, and the cost can be reduced.

  Further, as described above, the heat of the cooling water passing through the cooling water passage 10 warms the blow-by gas passing through the blow-by gas passage 15 and can prevent freezing of oil and moisture in the blow-by gas.

Next, what is shown in FIGS. 5 and 6 is a second embodiment. FIG. 5 is a cross-sectional view taken along the line AA in FIG. 6, and FIG. .
The difference from the structure shown in FIGS. 3 and 4 is that a parallel blowby gas passage 15a (through hole) is formed in communication with the downstream of the blowby gas passage 15 (through hole) in a perpendicular direction.
The parallel blowby gas passage 15a is formed in parallel to the flow direction of the intake air flowing through the intake passage R, and is opened so that blowby gas can be blown out along the flow direction of the intake air flowing through the intake passage R. Yes.

When the parallel blowby gas passage 15a is formed, a blind plug 18 is fitted and closed in a hole formed in a direction perpendicular to the blowby gas passage 15, and a blind plug 17 is also formed at the opening end of the blowby gas passage 15. It is inserted and closed.
The blow-by gas that has flowed into the support member 8 through the blow-by gas passage space 8a passes through the blow-by gas passage 15 and further passes through the parallel blow-by gas passage 15a in the perpendicular direction to the intake passage R in parallel with the intake air. It is blown out inside. The other structure is the same as that of the said FIG.3 and FIG.4.

  5 and 6, the blowby gas can be returned in parallel with the flow direction of the intake air flowing through the intake passage R, and the blowby gas is thus blown out along the flow direction of the intake air. With this configuration, it is possible to prevent the throttle valve from being contaminated by blow-by gas when the intake air is blown back.

It is a schematic block diagram of the cooling system of an internal combustion engine. It is a perspective view of an intake manifold attached to an engine. FIG. 5 is an enlarged cross-sectional configuration diagram viewed from the side of the throttle body mounting portion and the support member in FIG. 1, and shows a cross section taken along line AA in FIG. 4. It is the BB sectional view taken on the line of FIG. It is an expanded sectional block diagram corresponding to FIG. 3 of 2nd Example. It is the BB sectional drawing of FIG. 5 made to respond | correspond to FIG. 4 of 2nd Example.

DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Rocker cover 3 Support member 4 Intake manifold 5 Surge tank 6 Branch pipe 7 Throttle body attachment part 8 Support member 8a Blow-by gas passage space 9 Seated bolt 10 Cooling water passage 11 O-ring 12 PCV valve 13 Baffle plate 14 Air Liquid separation passage 15 Blow-by gas passage ( through hole )
15a Parallel blow-by gas passage ( through hole )
16, 17, 18 Blind plug R Intake passage

Claims (4)

A blow-by gas passage through which blow-by gas passes is formed in a support member that is integrally formed with the intake manifold and is attached to and supported by the engine, and the blow-by gas passage and the intake passage formed in the intake manifold, An intake manifold provided with a through-hole that communicates with each other,
The intake manifold has a throttle body mounting portion for mounting a throttle body,
The throttle body mounting portion is formed with a cooling water passage for circulating engine cooling water to prevent freezing of the throttle valve in the throttle body.
The support member is integrally formed with the throttle body mounting portion,
An intake manifold formed by forming a through hole in communication with the blow-by gas passage and the intake passage in the vicinity of the cooling water passage . The through hole, to the flow direction of the intake air flowing through the intake passage, so that the blow-by gas from the perpendicular direction is blown out, according to claim 1 comprising formed to perpendicularly opened to said intake passage Intake manifold. The intake manifold according to claim 1 , wherein the through hole is formed to open in parallel with the intake passage so that the blow-by gas is blown out along a flow direction of intake air flowing through the intake passage. The support member is formed in a covered cylindrical shape with the lower side open, and is attached to the rocker cover with a bolt,
The intake manifold according to any one of claims 1 to 3 , wherein the seating surface on the outer periphery of the lower end in contact with the rocker cover is set at substantially the same distance centering on a bolt hole into which the bolt is screwed.

Images