JP2008151078A - Engine air-intake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine air-intake device whose productivity can be improved while stabilizing air-fuel mixture combustion by the generation of a tumble. <P>SOLUTION: There are provided air-intake device of an engine 1 in which an air-intake passage 24 that communicates with a combustion chamber S is made up of an independent air-intake passage 22A within an air-intake manifold 22 and an air-intake port 9 and a fuel injection valve 21 is fitted on at an air-intake side of a cylinder head 8 and besides an air-intake control valve 25 and a partition wall 27a are provided in the air-intake passage 24. In the engine air-intake device, an air-intake control valve 25 is arranged at a downstream side of the independent air-intake passage 22A of the air-intake manifold 22. Then, a port liner 27 built up by integrating the partition wall 27a and a cylindrical passage 27b circularly encompassing the partition wall is inserted from an end face of the air-intake side of the cylinder head 8 into the air-intake port 9 to dispose an downstream-side end face of the passage 27b at a position where the end face does not interfere with fuel spray f subjected to injection from the fuel injection valve 21 and besides downstream-side end face of the partition wall 27a is protruded from the downstream-side end face of the passage 27b to the downstream side thereof. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention includes an intake control valve for deflecting the flow of intake air to the upper surface side of the intake passage, and a partition wall that divides the intake passage downstream of the intake control valve into upper and lower portions, and from the intake passage to the combustion chamber. The present invention relates to an engine intake device that induces a tumble flow in inflowing intake air.

  In order to purify the exhaust gas in the engine, it is effective to retard the ignition timing immediately after starting the engine to raise the exhaust gas temperature and to activate the catalyst for purifying the exhaust gas at an early stage.

  However, if the ignition timing is retarded immediately after the engine is started, the combustion of the air-fuel mixture becomes unstable. For this reason, combustion is stabilized by inducing a tumble flow (longitudinal vortex flow) in the intake air flowing into the combustion chamber. An example is shown in FIG.

  FIG. 9 is a longitudinal sectional view of a cylinder head portion showing a conventional engine intake device. The cylinder head 108 is formed with an intake port 109 and an exhaust port 110 for each cylinder. The intake manifold 122 is connected to the intake port 109. Although not shown, an exhaust manifold connected to the exhaust port 110 is connected to the exhaust side end face of the cylinder head 108. In the figure, reference numeral 130 denotes a plug hole for inserting an unillustrated spark plug.

  Incidentally, the intake passage 124 for introducing intake air into the combustion chamber S formed in the cylinder head 108 is constituted by an independent intake passage 122A in the intake manifold 122 and an intake port 109 formed in the cylinder head 108. An intake control valve 125 that rotates up and down about a shaft 126 is provided at a lower portion of the downstream end of the independent intake passage 122A of the intake manifold 122. An intake port 109 is provided at the upstream end of the intake port 109 of the cylinder head 108. A partition wall 127 is provided to divide the upper and lower sides.

  Thus, when the ignition timing is retarded immediately after engine startup for the purpose of purifying exhaust gas, the combustion of the air-fuel mixture in the combustion chamber S becomes unstable, so that the intake control valve 125 is centered on the shaft 126. The upper passage is pivoted up to the position of the partition wall 127, and the lower passage partitioned vertically by the partition wall 127 of the intake port 109 is closed by the intake control valve 125. Therefore, the intake air (fresh air) flowing through the independent intake passage 122A of the intake manifold 122 toward the combustion chamber S is deflected to the upper surface side of the intake passage 124 by the intake control valve 125 and the intake port 109 is partitioned. Although it flows through the upper channel | path divided | segmented up and down by the wall 127, since it restrict | squeezes at this time, the flow velocity is raised. Then, an air-fuel mixture is formed by injecting an appropriate amount of fuel from a fuel injection valve (not shown) into the intake air whose flow velocity is increased in this way, and this air-fuel mixture flows into the combustion chamber S vigorously. Tumble of the air-fuel mixture is generated in S, and combustion of the air-fuel mixture is stably performed by this tumble.

  In addition, in Patent Document 1, a rotary type intake control valve is rotatably disposed in the bottom wall of the cylinder head near the intake valve of the intake port, and combustion of the air-fuel mixture tends to become unstable. Proposals have been made to stably perform lean combustion by reducing the opening area of the intake port by using an intake control valve at a low intake air amount to increase the flow velocity of intake air and generating tumble of the air-fuel mixture in the combustion chamber.

Patent Document 2 proposes a technique in which a partition plate for vertically dividing the intake port of the cylinder head is cast at the same time as the cylinder head is cast.
JP-A-6-101486 JP 2004-211683 A

  However, in the intake device disclosed in Patent Document 1, since the intake control valve is built in the cylinder head, there is a problem that the structure of the cylinder head is complicated and its manufacturing cost is increased.

  On the other hand, in the intake device shown in FIG. 9, the intake control valve 125 is provided on the intake manifold 122 side, and only the partition wall 127 needs to be formed in the intake port 109 of the cylinder head 108. Although the problem that the structure is complicated does not occur, since the partition wall 127 is formed integrally with the cylinder head 108, there is a problem that the cylinder head 108 is not easily manufactured and the productivity is poor.

  In addition, in the air intake device disclosed in Patent Document 2, the partition plate is configured separately from the cylinder head, and this partition plate is cast at the same time as the cylinder head is cast. Is likely to occur, and productivity may deteriorate.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an engine intake device capable of improving productivity while stabilizing combustion of an air-fuel mixture by generation of tumble. There is.

In order to achieve the above object, according to the first aspect of the present invention, an intake manifold is attached to an intake side end face of a cylinder head, and an intake passage communicating with a combustion chamber is formed in the independent intake passage and the cylinder head in the intake manifold. An intake port, and a fuel injection valve is attached to the intake side of the cylinder head, while an intake control valve for deflecting the flow of intake air to the upper surface side of the intake passage and the intake control valve A partition wall that divides the downstream intake passage vertically, and an engine intake device that induces a tumble flow in the intake air flowing from the intake passage into the combustion chamber,

The intake control valve is disposed at the downstream end of the independent intake passage of the intake manifold, and a port liner formed by integrating the partition wall and a cylindrical passage portion annularly surrounding the partition wall is provided as an intake air of the cylinder head. Inserted from the side end face into the intake port, the downstream end face of the passage portion is positioned at a position not interfering with the fuel spray injected from the fuel injection valve, and the downstream end portion of the partition wall is placed in the passage It protruded from the downstream end surface of the part to the downstream side.

  The invention according to claim 2 is the invention according to claim 1, wherein a flange is integrally formed on the outer periphery of the upstream end of the port liner, and a ring-shaped seal member is integrally attached to the flange. It is characterized by.

  According to a third aspect of the present invention, in the first aspect of the invention, the port liner is integrally formed at the downstream end of the intake manifold.

  According to the first aspect of the present invention, the intake control valve is disposed at the downstream end of the independent intake passage of the intake manifold, and the partition wall and the cylindrical passage portion that annularly surrounds the partition wall are integrated. Since the liner is inserted into the intake port from the intake side end face of the cylinder head, there is no need to form a partition wall integrally with the cylinder head by casting or the like, and the structure of the cylinder head is simplified and easy to manufacture. And the productivity of the intake device is increased.

  Further, the downstream end face of the passage portion of the port liner is positioned at a position where it does not interfere with the fuel spray injected from the fuel injection valve, and the downstream end portion of the partition wall is projected from the downstream end face of the passage portion to the downstream side. Therefore, the fuel spray injected in a conical shape from the fuel injection valve does not collide with the partition wall to form a wall flow, and a mixture of the desired air-fuel ratio is formed and the partition wall is as downstream as possible. Thus, a strong tumble flow is generated in the cylinder to stabilize the combustion of the air-fuel mixture in the combustion chamber.

  As described above, the structure of the cylinder head can be simplified to increase the productivity of the intake device, and the shape and dimensions of the port liner can be optimized to stabilize combustion of the air-fuel mixture.

  According to the second aspect of the present invention, since the seal member is integrally attached to the flange portion integrally formed on the outer periphery of the upstream end portion of the port liner, the number of parts is reduced and the assembly work of the seal member is performed. Sexuality is enhanced. In addition, the positioning of the liner and the sealing are simultaneously performed by the flange portion, the seal structure of the attachment portion to the cylinder head end face of the intake manifold is simplified, and the productivity of the intake manifold and the cylinder head is enhanced.

  According to the third aspect of the present invention, since the port liner is integrally formed at the downstream end of the intake manifold, the number of parts is reduced and the productivity of the intake device is increased. Further, the wall surface of the intake passage extending from the intake control valve to the partition wall becomes smooth, the occurrence of turbulent flow is suppressed, the tumble generated in the cylinder is strengthened, and the combustion of the air-fuel mixture is further stabilized.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Embodiment 1>
1 is a longitudinal sectional view of an engine showing an intake device according to Embodiment 1 of the present invention, FIG. 2 is a front view of a port liner, FIG. 3 is a sectional view taken along line AA in FIG. 2, and FIG. It is a longitudinal cross-sectional view which shows the integration to a cylinder head.

  The engine 1 according to the present embodiment is an in-line four-cylinder engine, and the cylinder block 2 is provided with four cylinders 3 (only one is shown in FIG. 1) arranged in parallel in the direction perpendicular to the paper surface of FIG. . A piston 4 is fitted in each cylinder 3 so as to be slidable up and down, and each piston 4 is connected to a crankshaft 6 via a connecting rod 5. A crankcase 7 is attached to the lower part of the cylinder block 2, and the crankshaft 6 is arranged in the crankcase 7 in the direction perpendicular to the paper surface of FIG. The reciprocating linear motion of the upper and lower sides is converted into rotational motion of the crankshaft 6 by the connecting rod 5.

  The cylinder head 8 attached to the upper surface of the cylinder block 2 has an intake port 9 and an exhaust port 10 for each cylinder. One end of each of the intake port 9 and the exhaust port 10 is combusted. The chamber S is open. The openings of the intake port 9 and the exhaust port 10 to the combustion chamber S are opened and closed by the intake valve 11 and the exhaust valve 12 at appropriate timings.

  That is, the intake valve 11 and the exhaust valve 12 are slidably held by the valve guides 13 and 14 press-fitted into the cylinder head 8, and the valve lifters 15 and 16 are respectively crowned on the upper portions thereof. The intake valve 11 and the exhaust valve 12 are urged to close by valve springs 17 and 18, respectively. The intake lift cams 15 and 16 are provided with intake cams that are arranged to be rotatable in the direction perpendicular to the plane of FIG. An intake cam 19a and an exhaust cam 20a formed integrally with the shaft 19 and the exhaust cam shaft 20 are in contact with each other. Here, the intake camshaft 19 and the exhaust camshaft 20 are rotationally driven by the crankshaft 6, and the intake valve 11 and the exhaust valve 12 are respectively provided at appropriate timings by the intake cam 19a and the exhaust cam 20a formed integrally therewith. Are opened and closed, whereby the required gas exchange is performed in each cylinder 3.

  A fuel injection valve (injector) 21 for injecting an appropriate amount of fuel into the intake port 9 at an appropriate timing is attached to each cylinder on the intake side of the cylinder head 8.

  Incidentally, the intake port 9 formed for each cylinder is opened on the intake side end face of the cylinder head 8, and an intake manifold 22 connected to the intake port 9 is attached to the intake side end face. Here, a flange 22 a is formed at one end of each intake manifold 22, and a heat-resistant seal ring 23 is fitted on the joint surface of the flange 22 a, and the intake action is caused by the sealing action of the seal ring 23. Leakage of intake air from the joint surface between the manifold 22 and the cylinder head 8 is prevented. Although not shown, a throttle body and an air cleaner are attached to the upstream end of the intake manifold 22.

  Thus, an independent intake passage 22 A is formed in the intake manifold 22, and the independent intake passage and the intake port 9 of the cylinder head 8 constitute an intake passage 24 communicating with the combustion chamber S. An intake control valve 25 for deflecting the flow of intake air to the upper surface side of the intake passage 24 is provided at the lower portion of the downstream end of the independent intake passage 22A of the intake manifold 22 so as to be rotatable up and down about the shaft 26. It has been.

  A port liner 27 is inserted from the intake side end face of the cylinder head 8 at the upstream end of the intake port 9 of the cylinder head 8. Here, as shown in FIGS. 2 and 3, the port liner 27 is configured by integrating a flat partition wall 27a and a cylindrical passage portion 27b that surrounds the partition wall 27a in an annular shape. As shown in FIG. 4, a recess 9 a for assembling the port liner 27 is formed on the upstream side of the intake port 9 of the cylinder head 8.

  The port liner 27 is made of, for example, resin, and is inserted into the recessed portion 9a of the intake port 9 of the cylinder head 8 in the direction of the arrow and assembled before the intake manifold 22 is attached to the cylinder head 8, as shown in FIG. Thereafter, the intake manifold 22 is attached to the intake side end face of the cylinder head 8. Here, as shown in FIG. 1, the passage portion 27 b of the port liner 27 is configured such that its downstream end face is located at a position where it does not interfere with the conical fuel spray f injected from the fuel injection valve 21. The downstream end of the partition wall 27a protrudes from the downstream end face of the passage portion 27b to the downstream side by a predetermined length (maximum length within a range not interfering with the fuel spray f injected from the fuel injection valve 21). ing.

  On the other hand, an exhaust manifold (not shown) connected to the exhaust port 10 is attached to the exhaust side end face of the cylinder head 8, and although not shown, a catalytic converter and an exhaust pipe are connected to the exhaust manifold.

  Thus, when the engine 1 is started, intake air (fresh air) flows toward the combustion chamber S in the intake passage 24 due to the cranking negative pressure generated in the cylinder 3 of each cylinder. An appropriate amount of fuel is injected from the fuel injection valve 21 to form a mixture of desired air-fuel ratio (A / F), and this mixture enters the cylinder 3 when the intake valve 11 is opened in the intake stroke. Inflow. The air-fuel mixture flowing into the cylinder 3 is compressed by the piston 4 in the compression stroke in which the intake valve 11 and the exhaust valve 12 are closed, and then ignited and burned by an ignition plug (not shown) immediately before the piston 4 reaches top dead center. The piston 4 is lowered by receiving a high combustion pressure on the upper surface thereof, and the exhaust valve 12 is opened in the exhaust stroke in which the piston 4 goes up after passing through the bottom dead center. The exhaust gas is discharged from the exhaust manifold (not shown) to the atmosphere through the catalytic converter and the exhaust pipe.

  By the way, when the ignition timing is retarded immediately after the start of the engine 1 for the purpose of purifying exhaust gas, combustion of the air-fuel mixture in the combustion chamber S becomes unstable, so the intake control valve 25 is centered on the shaft 26. The passage is rotated upward to the position of the partition wall 27 a of the port liner 27, and the passage below the intake port 9 partitioned up and down by the partition wall 27 a is closed by the intake control valve 25. Therefore, the intake air (fresh air) flowing through the independent intake passage 22A of the intake manifold 22 toward the combustion chamber S is deflected to the upper surface side of the intake passage 24 by the intake control valve 25 and the intake port 9 is partitioned. Although it flows through the upper channel | path divided up and down by the wall 27a, since it restrict | squeezes at this time, the flow velocity is raised. An air-fuel mixture is formed by injecting an appropriate amount of fuel from the fuel injection valve 21 into the intake air whose flow velocity is increased in this way, and this air-fuel mixture flows into the combustion chamber S vigorously. 1 generates a tumble of the air-fuel mixture as indicated by the arrow in FIG. 1, and the combustion of the air-fuel mixture is stably performed by this tumble.

  As described above, in the present embodiment, the intake control valve 25 is disposed at the downstream end of the independent intake passage 22A of the intake manifold 22, and the partition wall 27a and the cylindrical passage portion 27b that annularly surrounds the partition wall 27a. Is inserted into the intake port 9 from the intake side end face of the cylinder head 8, so that it is not necessary to form the partition wall 27a integrally with the cylinder head 8 by casting or the like. The structure of the head 8 is simplified, the manufacture thereof is facilitated, and the productivity of the intake device is increased.

  Further, the downstream end face of the passage portion 27b of the port liner 27 is positioned at a position where it does not interfere with the fuel spray f injected from the fuel injection valve 21, and the downstream end portion of the partition wall 27a is connected to the downstream end face of the passage portion 27b. The fuel spray f injected in a conical shape from the fuel injection valve 21 does not collide with the partition wall 27a to form a wall flow, and a desired air-fuel ratio mixture is formed. By extending the partition wall 27a as far downstream as possible, a strong tumble flow can be generated in the cylinder 3, whereby the combustion of the air-fuel mixture in the combustion chamber S is stabilized.

  Thus, in the present embodiment, the structure of the cylinder head 8 can be simplified to increase the productivity of the intake device, and the shape and dimensions of the port liner 27 can be optimized to stabilize combustion of the air-fuel mixture. .

<Embodiment 2>
Next, a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 5 is a longitudinal sectional view of a cylinder head portion showing an intake device according to the present embodiment, FIG. 6 is a front view of a port liner, and FIG. 7 is a sectional view taken along line BB in FIG. The same elements as those shown in FIGS. 1 to 4 are denoted by the same reference numerals, and description thereof will be omitted below.

  This embodiment is characterized in that a flange portion 27c is integrally formed on the outer periphery of the upstream end portion of the port liner 27, and a ring-shaped seal member 28 is integrally attached to the flange portion 27c. Is the same as in the first embodiment. Here, as shown in FIG. 5, the joint end face of the flange 22a of the intake manifold 22 is formed with a recess 22b for accommodating the flange portion 27c of the port liner 27, and the port liner 27 is provided with the flange portion 27c. Is positioned by abutting against the intake side end face of the cylinder head 8.

  Thus, according to the present embodiment, since the seal member 28 is integrally attached to the flange portion 27c integrally formed on the outer periphery of the upstream end portion of the port liner 27, the number of parts is reduced and the seal Assembling workability of the member 28 is improved. Further, the flange 27c simultaneously positions and seals the port liner 27, simplifies the seal structure of the attachment portion of the intake manifold 22 to the end face of the cylinder head 8, and increases the productivity of the intake manifold 22 and the cylinder head 8. It is done.

  In this embodiment, the concave portion 22b for accommodating the flange portion 27c of the port liner 27 is formed on the intake manifold 22 side. However, the concave portion for accommodating the flange portion 27c of the port liner 27 is provided on the cylinder head 8 side. Even if formed, the same effect can be obtained.

<Embodiment 3>
Next, Embodiment 3 of the present invention will be described with reference to FIG.

  FIG. 8 is a longitudinal sectional view of a cylinder head portion showing the intake device according to the present embodiment. In this figure, the same elements as those shown in FIGS. The re-explanation about them is omitted.

  The present embodiment is characterized in that the port liner 27 is formed integrally with the downstream end of the intake manifold 22, and the other configuration is the same as that of the first embodiment.

  Thus, according to the present embodiment, since the port liner 27 is integrally formed at the downstream end of the intake manifold 22, the number of parts is reduced and the productivity of the intake device is increased. Further, the wall surface of the intake passage 24 extending from the intake control valve 25 to the partition wall 27a becomes smooth, the occurrence of turbulence is suppressed, the tumble generated in the cylinder 3 is strengthened, and the combustion of the air-fuel mixture is further stabilized. Figured.

It is a longitudinal cross-sectional view of the engine which shows the intake device which concerns on Embodiment 1 of this invention. It is a front view of the port liner of the air intake device according to Embodiment 1 of the present invention. It is the sectional view on the AA line of FIG. It is a longitudinal cross-sectional view which shows the assembly to the cylinder head of the port liner in the intake device which concerns on Embodiment 1 of this invention. It is a longitudinal cross-sectional view of the cylinder head part which shows the intake device which concerns on Embodiment 2 of this invention. It is a front view of the port liner of the intake device which concerns on Embodiment 2 of this invention. It is the BB sectional view taken on the line of FIG. It is a longitudinal cross-sectional view of the cylinder head part which shows the intake device which concerns on Embodiment 3 of this invention. It is a longitudinal cross-sectional view of a cylinder head portion showing a conventional engine intake device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Cylinder block 3 Cylinder 4 Piston 5 Connecting rod 6 Crankshaft 7 Crankshaft 8 Cylinder head 9 Intake port 9a Intake port recessed part 10 Exhaust port 11 Intake valve 12 Exhaust valve 13,14 Valve guide 15,16 Valve lifter 17,18 Valve Spring 19 Intake cam shaft 19a Intake cam 20 Exhaust cam shaft 20a Exhaust cam 21 Fuel injection valve 22 Intake manifold 22A Intake manifold independent intake passage 22a Intake manifold flange 22b Intake manifold recess 23 Seal ring 24 Intake passage 25 Intake control valve 26 Shaft 27 Port liner 27a Port liner partition wall 27b Port liner passage portion 27c Port liner flange 28 Seal member f Fuel spray S Combustion chamber

Claims (3)

An intake manifold is attached to the intake side end face of the cylinder head, and an intake passage communicating with the combustion chamber is constituted by an independent intake passage in the intake manifold and an intake port formed in the cylinder head, and is provided on the intake side of the cylinder head. While the fuel injection valve is attached, the intake passage includes an intake control valve for deflecting the flow of intake air to the upper surface side of the intake passage and a partition wall that divides the intake passage downstream of the intake control valve vertically. An engine intake device that induces a tumble flow in the intake air flowing into the combustion chamber from the intake passage;
The intake control valve is disposed at the downstream end of the independent intake passage of the intake manifold, and a port liner formed by integrating the partition wall and a cylindrical passage portion annularly surrounding the partition wall is provided as an intake air of the cylinder head. Inserted from the side end face into the intake port, the downstream end face of the passage portion is positioned at a position not interfering with the fuel spray injected from the fuel injection valve, and the downstream end portion of the partition wall is placed in the passage An air intake device for an engine, wherein the air intake device projects from the downstream end face of the portion to the downstream side.   The engine intake device according to claim 1, wherein a flange portion is integrally formed on the outer periphery of the upstream end portion of the port liner, and a ring-shaped seal member is integrally attached to the flange portion. 2. The engine intake system according to claim 1, wherein the port liner is integrally formed at a downstream end of the intake manifold.

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