JPH0725233U - Intake port for tumble generation - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to reliably generate tumble in an operating region that requires tumble, including extremely low load, and promote combustion improvement. A step 10 is provided in the intake port 2 in the vicinity of the intake valve 2a on the inner wall surface on the convex side of the bent portion so that the intake flow is diverted.
EC provided with a jet port 11 facing the above, and an air passage 12 communicating with the jet port 11 in the middle of a control system of the engine.
It is configured to communicate with the intake passage 4 upstream of the throttle valve 5 via a valve 13 whose opening and closing is controlled by U8.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an intake port that generates tumble, and more particularly, to a tumble generation port mechanism that causes a tumble in a combustion chamber by providing a step in the intake port to cause the intake flow to flow unevenly.

[0002]

[Prior art]

 As a means for improving the combustion of an engine, various methods have heretofore been proposed in which an auxiliary air intake passage is provided in the vicinity of an intake valve and a tumbling is caused in the combustion chamber by a jet flow flowing from the auxiliary air intake passage into the combustion chamber.

FIG. 4 shows an example of the conventional example. As shown in FIG. 4, a main intake passage c having an injector d is communicated with an intake valve b of a cylinder a, and the main intake passage c is connected to the main intake passage c. A first intake throttle valve e and a second intake throttle valve f are provided upstream of the intake throttle valve, and a sub intake passage g having a small inner diameter is branched from a main intake passage c upstream of the intake throttle valve e. In addition, the structure is such that they merge again near the intake valve b. With this configuration, the opening of the intake throttle valve e is throttled when the load is low, and the flow velocity of the air flowing from the auxiliary intake passage g into the cylinder a is increased, so that the jetted intake air flows into the cylinder a and the inside wall of the cylinder a is awakened. A collision tumble (vertical swirl) is generated (described in Japanese Utility Model Laid-Open No. 59-156122).

[0004]

[Problems to be solved by the device]

 By the way, in the case of an intake mechanism in which the jet from the auxiliary intake passage causes tumble as in the above-mentioned conventional example, when the intake air amount is extremely small, such as when the load is extremely low, the effect is not exhibited. There was a problem that tumble did not occur indoors.

The present invention has been devised to solve the above-mentioned problems, and reliably causes tumbles in an operating region that requires tumbles including extremely low loads to improve combustion. The purpose is to promote.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a step in an intake port having a curved portion that communicates with an intake valve of a cylinder, in which an intake flow is diverted to a convex inner wall surface of the curved portion near the intake valve. In addition to the above-mentioned step, an injection port facing the step is provided upstream of the step, and an air passage communicating with the injection port is provided on the way with a valve that is controlled to open and close by an ECU provided in an engine control system. The control valve from the ECU opens the valve in at least the operating region when the load is high, so that the jet flow ejected from the jet port is described above. It is characterized in that it comes into contact with the step.

[0007]

[Action]

 Based on the above configuration, in the low load operation region, a part of the intake flow hits the convex inner wall surface of the intake port, that is, the step provided on the inner peripheral side wall surface of the curved portion, and the concave side of the curved portion, that is, the outer periphery. It drifts toward the inner wall surface. Due to the uneven flow, the entire intake flow is unevenly distributed in the direction of the outer peripheral side wall surface, so that the intake flow flows into the combustion chamber along the outer peripheral side wall surface and reliably causes tumble in the combustion chamber. In the medium / high load operating range, a valve is opened by a control signal from the ECU, and the jet flow ejected from the injection port is brought into contact with the step so that the area from the injection port to the step has an air barrier shape. To prevent the intake flow from hitting the step. As a result, the intake flow does not flow unevenly and flows into the combustion chamber to prevent the charging efficiency from decreasing.

[0008]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an intake system to which a tumble generating port mechanism according to the present invention is applied. Reference numeral 1 is a cylinder head that forms an upper portion of an engine body, and the cylinder head 1 has an engine through an intake valve 2a. An intake port 2 having a bent portion opening to the combustion chamber and an exhaust port 3 having a bent portion opening to the engine combustion chamber via an exhaust valve 3a are formed.

An intake passage 4 communicates with the intake port 2, and a throttle valve 5 and an injector 6 are provided downstream of the throttle valve 5 in the intake passage 4. Further, a bypass passage 7 communicates with the intake passage 4 extending upstream and downstream of the throttle valve 5, and in the middle of the bypass passage 7 is controlled by an ECU 8 provided in a control system of the engine. The ISC valve 9 is interposed.

In the present invention, a step 10 is provided in the intake port 2 so as to make the intake flow uneven. The step 10 is formed in the vicinity of the intake valve 2a, and the inner surface of the convex side of the bent portion of the intake port 2, that is, as shown in FIG. 2 which is a sectional view taken along the line AA of FIG. It is formed on the inner wall surface on the inner circumference side. By providing the step 10, a part of the intake airflow flowing into the intake port 2 hits the step 10 and is diverted toward the concave side of the intake port 2, that is, toward the outer peripheral side of the intake port 2, and the entire intake flow is taken by the divergence. Unbalanced flow to the outer peripheral side of port 2. In addition, an injection port 11 that faces the step is provided upstream of the step 10 by a required distance, and an air passage 12 that communicates with the injection port 11 is provided, and a valve 13 that is controlled to open and close by an ECU 8 is interposed midway through the throttle valve. 5 is connected to the intake passage 4 upstream.

Next, the operation of the present invention will be described with reference to FIGS. 3 (A) and 3 (B). When the engine is operating at a low load where tumble generation is required, as shown in FIG. 3 (A), part of the intake flow flowing into the intake port 2 is the inner wall surface of the intake port 2 on the inner peripheral side. By hitting the step 10 provided in the intake port 2, the flow is eccentric to the outer peripheral side of the intake port 2 as indicated by the arrow in the figure. The uneven flow causes the entire intake flow to be unevenly distributed to the outer peripheral side of the intake port 2, so that the intake flow flows toward the center of the combustion chamber along the inner wall surface of the outer peripheral side of the intake port 2 and causes tumble in the combustion chamber. . After that, the tumble collapses in the latter half of the compression stroke, and the intake flow combusts turbulently, so that the combustion speed is fast and the combustion is stable, so that the combustion is greatly improved.

When the engine is operating under medium or high load where tumble generation is unnecessary, the valve 13 is opened by the control signal from the ECU and the jet flow is made to flow into the intake port 2 from the injection port 11. Since the jet port 11 is opened to face the step, the jet abuts the step 10 as shown in FIG. 2 (B), and an air barrier is formed in the region α from the jet port to the step. Then, make sure that the intake flow does not hit the step. As a result, the intake air flows into the combustion chamber without uneven flow and prevents the charging efficiency from decreasing.

[0013]

[Effect of device]

 As described above, according to the present invention, by providing a step in the intake port, the intake flow is diverted at the time of low load that requires tumble generation, and tumbling is reliably generated in the combustion chamber. As a result, combustion is improved, and the effects of low fuel consumption and high output are obtained. Further, at the time of medium / high load where tumble generation is not required, the jet flow is brought into contact with the step to prevent the intake flow from being lopsided, so that the reduction of the filling efficiency can be prevented.

[Brief description of drawings]

FIG. 1 is a block diagram of an intake system to which a tumble generating port mechanism according to the present invention is applied.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3A is an explanatory view of the operation of the tumble generation port mechanism according to the present invention. FIG. 3B is an operation explanatory view of the tumble generation port mechanism according to the present invention.

FIG. 4 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 1 Cylinder head 2 Intake port 2a Intake valve 3 Exhaust port 3a Exhaust valve 4 Intake passage 5 Throttle valve 6 Injector 7 Bypass passage 8 ECU 9 ISC valve 10 Step 11 Jet port 12 Air passage 13 Valve α area

Claims (1)

[Scope of utility model registration request] 1. A step for deflecting an intake air flow is provided on a convex inner wall surface of the bent portion near the intake valve in an intake port having a bent portion communicating with the intake valve, and a required distance from the step. An intake passage upstream of the throttle valve is provided with an injection port facing the step upstream, an air passage communicating with the injection port, and an air passage in the middle of which a valve that is controlled to open and close by an ECU provided in an engine control system is interposed. Is characterized in that, at least in an operating region under high load, the valve is opened by a control signal from the ECU so that the jet flow ejected from the injection port comes into contact with the step. Intake port for tumble generation.