JPH0722032U - Engine intake system - Google Patents

Abstract

(57) [Abstract] [Purpose] An engine that has a relatively simple structure and that is capable of generating a strong tumble flow in the cylinder during the intake stroke of the engine while sufficiently maintaining the function of the intake valve. Provide an intake device. [Structure] A deflector plate 13 is provided for deflecting an intake air flow passing through an intake port 8 of an engine to a central portion side of a combustion chamber 7 to generate a tumble flow in the cylinder 4. The intake air of the engine mounted on the valve stem portion 6a of the intake valve 6 facing the inside of the intake port 8 so as to be rotatable relative to the intake port 8 while being prevented from rotating by engagement with the guide rib 8b formed on the curved inner wall surface 8a of the intake port 8. apparatus.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an engine intake device capable of generating a strong tumble flow in a cylinder during an engine intake stroke.

[0002]

[Prior art]

 In the engine operating region, where the throttle opening is small and the intake air amount is small accordingly, in the low load region, the air-fuel mixture is generally set rich to stabilize combustion, resulting in poor fuel efficiency and emissions. Tend to do. Therefore, as a measure for improving the fuel consumption and the emission as described above, a technique of generating a tumble flow in the intake mixture in the cylinder has been generally known. The generation of this tumble flow swirls the intake air-fuel mixture along the axial direction of the cylinder, and the tumble flow collapses in the latter half of the compression stroke to generate strong turbulence, and this turbulent mixture is ignited. By doing so, turbulent combustion with high combustion speed and stable combustion can be obtained, which is particularly effective for improving combustion in the low and medium load regions of the engine.

Such a tumble flow can be generated by sucking the intake flow passing through the intake port into the cylinder as a deflected flow closer to the center of the combustion chamber. Therefore, conventionally, various intake devices have been proposed that generate a deflected flow for generating a tumble flow in the intake port (see Japanese Utility Model Publication No. 59-156122 and Japanese Utility Model Publication No. 63-48920). .

In the intake device described in Japanese Utility Model Laid-Open No. 59-156122, the vicinity of the intake port is divided into a main intake passage and an auxiliary intake passage, and a low engine load is placed in the main intake passage. An on-off valve that closes in the region is installed.In the low-load region of the engine where this on-off valve is closed, a tumble flow is generated by sucking the air-fuel mixture into the cylinder as a deflected flow from only the auxiliary intake passage. It was done. Further, in the intake device described in Japanese Utility Model Laid-Open No. 63-48920, a rectifier formed integrally with the valve head of the intake valve causes the intake flow passing through the intake port to be biased toward the center of the combustion chamber. It is designed to be inhaled inside.

[0005]

[Problems to be solved by the device]

 By the way, the intake device described in Japanese Utility Model Laid-Open No. 59-156122 has a structure that requires a partition wall for partitioning the vicinity of the intake port into a main intake passage and a sub intake passage, and an opening / closing valve for the main intake passage. Therefore, the structure is relatively complicated. Further, in the intake device disclosed in Japanese Utility Model Laid-Open No. 63-48920, the intake valve has a rectifying portion integrally formed with the intake valve for diverting the intake air flow in the intake port toward the center of the combustion chamber. There is a problem that it cannot rotate around the axis of the valve system and uneven wear occurs on the contact surfaces of the valve head and the valve seat, impairing the function of the intake valve.

Therefore, the present invention has a relatively simple structure and is capable of generating a strong tumble flow in the cylinder during the intake stroke of the engine while sufficiently maintaining the function of the intake valve. An object is to provide an intake device.

[0007]

[Means for Solving the Problems]

 To this end, the present invention provides a deflector plate that allows the intake flow passing through the intake port of the engine to be deflected toward the center of the combustion chamber to generate a tumble flow in the cylinder. The means is that the valve stem is mounted on the valve stem portion of the intake valve facing the inside of the intake port so as to rotate relative to itself while being prevented from rotating by engagement with the guide rib formed on the inner wall of the port.

[0008]

[Action]

 In the engine intake system according to the present invention which employs such means, the intake flow passing through the intake port during the intake stroke of the engine is distributed to the deflector plate attached to the valve stem portion of the intake valve facing the intake port. Since the fluid is guided and drifts toward the center of the combustion chamber and is sucked into the cylinder, a strong tumble flow is generated in the cylinder.

[0009] Here, since the flow diverter plate is engaged with the guide rib in the intake port and is prevented from rotating, and is attached so as to be rotatable relative to the valve stem portion of the intake valve, the intake valve is Since the valve stem is rotated around the axis of the valve stem in accordance with the opening / closing operation, uneven wear of the contact surfaces of the valve head and the valve seat is prevented.

[0010]

【Example】

 Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings. In FIG. 1, which shows an overall schematic structure of an engine intake device according to one embodiment, reference numeral 1 denotes an engine body in which a cylinder head 3 is connected to a cylinder block 2, and a piston 5 slides in a cylinder 4 of the cylinder block 2. It is movably fitted.

Further, the cylinder head 3 is formed with an intake port 8 communicating with the combustion chamber 7 via an intake valve 6 and an exhaust port 10 communicating with the combustion chamber 7 via an exhaust valve 9. . An end portion of an intake manifold 11 for distributing the air-fuel mixture is connected to the cylinder head 3 continuously with the intake port 8. An ignition plug 12 is installed in the center of the combustion chamber 7.

At the valve stem portion 6 a of the intake valve 6 that faces the intake port 8, there is a deflector plate 13 that causes the mixed airflow passing through the intake port 8 to flow toward the center of the combustion chamber 7. It is installed.

FIG. 2 shows the appearance of the flow diverter plate 13. This has a form in which a cylindrical portion 13b having a fitting hole 13a bulges in the central portion with its axis tilted. A guide groove 13d is formed in the peripheral edge of the continuous brim-shaped main body 13c on the inclined side of the cylindrical portion 13b. As shown in FIG. 3, the deflector plate 13 has a fitting hole 13a so as to cover a large-diameter shaft portion 6c connecting the valve stem portion 6a of the intake valve 6 and the valve head 6b. A stop ring 15 such as a C-shaped ring, which is loosely fitted to the valve stem portion 6a so as to be rotatable relative to the valve stem portion 6a and is attached to the valve stem portion 6a together with the wave washer 14, and a step portion 6d on the large diameter shaft portion 6c side. Held in between.

On the other hand, as shown in FIG. 1, a guide rib 8b slidably engaged with the guide groove 13d of the flow diverter plate 13 is provided on the wall surface 8a of the intake port 8 on the inner side of the bend. The deflector plate 13 in which the guide groove 13d is engaged with the guide rib 8b is in a state in which the main body 13c is inclined so that the mixed airflow passing through the suction port 8 is biased toward the center of the combustion chamber 7. It is prevented from rotating around and can be moved up and down together with the valve stem portion 6a in this state.

Next, the operation of the intake system for the engine according to the present embodiment configured as described above will be described. In the present embodiment, during the intake stroke of the engine with the intake valve 6 open, the intake air-fuel mixture that has flowed into the intake port 8 from the intake manifold 11 is located in the center of the combustion chamber 7 along the main body 13c of the flow diverter plate 13. Unbalanced flow to the department side. This deflected flow of the intake air-fuel mixture is sucked into the cylinder 4 along the cylinder wall surface on the exhaust valve 9 side from the center of the combustion chamber 7 as shown by the arrow in FIG. By reversing on the upper surface of 5, the tumble flow of the intake air-fuel mixture is generated in the cylinder 4.

Then, the tumble flow of the intake air-fuel mixture generated in the cylinder 4 collapses and becomes turbulent in the latter half of the compression stroke of the engine, so that stable and rapid turbulent combustion is performed. The thermal efficiency is improved, the fuel efficiency is greatly improved, and the exhaust emission is improved.

Here, the drift plate 13 is engaged with a guide rib 8b in the intake port 8 to prevent rotation, and is attached to the valve stem portion 6a of the intake valve 6 so as to be rotatable relative thereto. Therefore, the intake valve 6 can be rotated around the axis of the valve stem portion 6a according to the opening / closing operation. Therefore, uneven wear of the contact surface between the valve head 6b of the intake valve 6 and the valve seat 16 is prevented in advance, and the function of the intake valve 6 is sufficiently maintained.

Structurally looking at the present embodiment, the flow diverter plate 13 is attached to the intake port 8 while being prevented from rotating by engagement with the guide rib 8b formed on the inner wall surface 8a of the intake port 8 which is bent. Since it suffices to relatively rotatably mount the valve stem portion 6a of the intake valve 6 facing inside, a partition for partitioning the vicinity of the intake port 8 into a main intake passage and an auxiliary intake passage, and an opening / closing valve for the main intake passage are required. The structure is relatively simple compared to the conventional structure.

[0019]

[Effect of device]

 As described above, according to the present invention, during the intake stroke of the engine, the intake air flow passing through the intake port is guided by the deflector plate that is attached to the valve stem portion of the intake valve and faces the intake port, and is guided to the center of the combustion chamber. It is sucked into the cylinder while being partially biased. Therefore, a strong tumble flow can be generated in the cylinder during the intake stroke of the engine.

Here, the deflector plate is engaged with a guide rib in the intake port and is prevented from rotating, and is attached so as to be rotatable relative to the valve stem portion of the intake valve. It rotates around the axis of the valve stem according to the opening / closing operation. Therefore, uneven wear of the contact surface between the valve head of the intake valve and the valve seat is prevented, and the function of the intake valve can be sufficiently maintained.

Structurally, in the present invention, the present invention mainly includes a deflector plate that is relatively rotatably attached to a valve stem portion of an intake valve while being prevented from rotating by a guide rib of an intake port. Therefore, the structure is relatively simple as compared with the conventional example of the structure that requires the partition wall that divides the vicinity of the intake port into the main intake passage and the sub intake passage and the opening / closing valve of the main intake passage.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the overall schematic configuration and operation of an embodiment of an engine air intake device according to the present invention.

FIG. 2 is an external perspective view of a deflector plate in one embodiment.

FIG. 3 is a cross-sectional view showing a mounting structure for a deflector plate in one embodiment.

[Explanation of symbols]

 1 Engine Body 2 Cylinder Block 3 Cylinder Head 4 Cylinder 5 Piston 6 Intake Valve 6a Valve Stem Part 6b Valve Head 6c Large Diameter Shaft 6d Step 7 Combustion Chamber 8 Intake Port 8a Bending Inner Wall Surface 8b Guide Rib 9 Exhaust Valve 10 Exhaust Port 11 Intake Manifold 12 Spark Plug 13 Drift Plate 13a Fitting Hole 13b Cylinder 13c Main Body 13d Guide Groove 14 Wave Washer 15 Stop Ring 16 Valve Seat

Claims (1)

[Scope of utility model registration request] 1. A deflector plate is provided for biasing an intake air flow passing through an intake port of an engine toward a central portion of a combustion chamber to generate a tumble flow in a cylinder. The deflector plate is an inner wall of the intake port. An intake device for an engine, wherein the intake device is mounted on a valve stem portion of an intake valve facing an intake port while being prevented from being rotated by engagement with a guide rib formed on the engine.