JPH02256824A - Passage opening adjusting device for spiral suction port of direct ignition type diesel engine - Google Patents

Abstract

PURPOSE:To generate a sufficient swirl at a low speed, in spite of a comparatively large passage opening, by constituting a passage opening adjusting device in such a way that its movement of advance/retreat can be adjusted from the underside of an intake-air introducing passage toward the top-face side. CONSTITUTION:A passage opening adjusting device 18 is supported on the lower part of the side wall of an intake-air introducing passage 15 via a horizontal supporting shaft 19, in such manner that it can be freely rocked up and down, and the advance or retreat of the device 18 from the underside 15a of the intake-air introducing passage 15 toward the top-face side 15b thereof can be adjusted. The horizontal supporting shaft 19 is controlled in its rotation by an actuator in such a manner that the more the speed decreases, the more the passage opening adjusting device 18 is projected upward, thereby the passage opening is reduced. Accordingly, if the passage opening adjusting device 18 is projected upward to reduce the passage opening, the intake-air flow, whose velocity is increased, goes into the upper part of a spiral chamber 16, sufficiently swirls till it reaches a valve port 8, and goes into a cylinder chamber 17.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a passage opening adjustment device for a spiral intake port of a direct injection diesel engine.

(Prior art) Conventionally, as the above-mentioned passage opening adjustment device, the devices shown in Figs.
There is one shown in the figure. This connects the intake introduction path 12 of the spiral intake port 11 to the spiral chamber 13 and the valve port 14.
A passage opening adjuster 16 is provided in the intake introduction passage 12 so as to be able to swing around a vertical axis parallel to the valve axis, and the passage opening can be reduced at low speeds. , the intake flow velocity here is increased, thereby stably generating a swirl in the spiral chamber 13.

(Problem to be Solved by the Invention) When reducing the passage opening degree in this way, in the conventional structure described above, the intake air flow is biased toward the side wall of the intake air introduction passage 12 as a whole, so that the spiral chamber 13 The intake air flow that enters the upper part has a large axial distance to the valve port 14, so the number of turns is large, but the intake air flow that enters the lower part of the spiral chamber 13 reaches the valve port 14 without sufficiently turning. The intake air flows into the cylinder chamber 15, and in order to obtain a sufficient overall swirling force, it is necessary to sufficiently narrow the passage opening and increase the intake flow velocity.

In other words, as a result of greatly restricting the passage opening in order to generate sufficient swirl at low speeds, the intake air filling efficiency tends to decrease and the maximum torque in the low rotation range tends to decrease.

The present invention has been made in view of this situation, and by simply making improvements to the passage opening adjustment section, it is possible to generate sufficient whirl while keeping the passage opening relatively large at low speeds. The purpose of this invention is to provide a passage opening adjustment device for a spiral-shaped intake port of a direct injection diesel engine that can improve combustion efficiency in the low rotation range and intake air filling efficiency all at once. do.

(Means for Solving the Problems) The characteristic configuration of the present invention for achieving the above object is to communicate the intake air introduction passage of the spiral intake port of the direct injection diesel engine to the cylinder chamber via the spiral chamber and the valve port. In the passage opening adjustment device for the spiral-forming sport of the MF & injection JT type diesel ennon, which is configured by providing the intake introduction passage with an adjustable passage opening, the passage opening adjustment is possible by adjusting the opening of the intake passage. The main feature is that it is configured to be adjustable and movable forward and backward from the bottom side toward the top side.

(Function) According to the characteristic configuration described above, when the passage opening adjustment is made to protrude from the bottom side of the intake introduction passage to the top side in order to increase the intake air flow velocity in the intake introduction passage at low speeds, the main intake air flow is You will enter the spiral chamber by leaning towards the upper side. In other words, the main intake flow with increased flow velocity enters the upper portion of the spiral chamber having a large distance from the valve port in the centroidal direction, and the number of turns to reach the valve port increases.

Therefore, the intake speed to provide the necessary swirl in the cylinder chamber may be lower than when the number of turns is small; in other words, the necessary swirl can be obtained without reducing the passage opening degree.

(Example) Embodiments of the present invention will be described below based on the drawings.

Figure 3 shows the entire cross section of the direct injection air-cooled diesel Ennon E, and the reference numeral 1 in the figure indicates the crankcase;
2 is a crankshaft, 3 is a piston, 4 is a cylinder, 5 is a cylinder head, 6 is an intake valve, 7 is a spiral type intake port, 8 is a valve port, 9 is an exhaust valve, 10 is an exhaust port, 11 is a valve port, 12 is a flywheel equipped with a centrifugal 7 ann 13;
14 is a spiral casing for guiding cooling air.

Figure 2 shows a cross section of 5 parts of the cylinder head.
The intake air introduction passage 15 of the spiral intake port 7 is communicated with the cylinder chamber 17 via the spiral chamber 16 and the valve port 8, and the intake air introduction passage 15 is provided with a passage opening adjustment tool 18.
is provided.

The passage opening degree adjuster 18 is supported at the lower part of the side wall of the intake air introduction passage 15 via a horizontal support shaft 19 so as to be able to swing vertically. It can be adjusted forward and backward. One horizontal support shaft is connected to a solenoid, a diaphragm operated by intake negative pressure, or the oil pressure of a lubricating oil supply pump so that the lower the speed, the more the passage opening adjuster 18 is operated upward to reduce the passage opening. The rotation is controlled by an actuator (not shown) such as a diaphragm operated by a diaphragm. Note that the reference numeral 20 in FIG. 1 is an injection nozzle mounting hole.

Therefore, when the passage opening degree adjuster 18 is projected upward and the passage opening degree is decreased, the intake air whose flow velocity has increased due to the decrease in the passage opening degree enters the upper part of the spiral chamber 16 and reaches the valve port 8. In the meantime, it turns sufficiently and flows into the cylinder chamber 17.

Note that the passage opening degree adjuster 18 is connected to the intake air introduction passage 1 as shown in the figure.
The pond may be partially provided on one side (outward side of turning) in the width direction of the wheel 5, or may be provided over the entire width in the width direction.

(Effects of the Invention) As is clear from the above description, in the present invention, the intake air at low speeds is biased toward the upper surface of the passage by the passage opening adjustment device so that it enters the viral chamber again. Sufficient swirl can be generated even at a low flow rate while reaching the valve opening at the bottom of the viral chamber, and as a result, the necessary swirl can be generated without making the passage opening too small, improving intake air filling efficiency. This makes it possible to increase the maximum torque in the low rotation range.

[Brief explanation of drawings]

Figures 1 to 3 show embodiments of the present invention, with Figure 1 being a cross-sectional plan view of the cylinder head, Figure 2 being a perspective view of the spiral intake port, and Figure 3 being a longitudinal side view of the engine. be. Further, FIG. 4 is a cross-sectional plan view of a cylinder head portion in a conventional structure, and FIG. 5 is a perspective view of its intake port. ? ...Spiral type suction port, 15...Intake introduction passage, 15a...Bottom surface, 15b...Top surface, 16...Spiral chamber, 17...Cylinder chamber, 18...Passage opening degree Adjustment tool, E...Engine. Patent applicant Kubota Iron Works Co., Ltd. Figure 2 Figure 3

Claims (1)

[Claims] 1. The intake air introduction passage 15 of the spiral intake port 7 of the direct injection diesel engine E is communicated with the cylinder chamber 17 via the spiral chamber 16 and the valve port 8, and a passage is opened in the intake air introduction passage 15. In the passage opening adjustment device for the spiral intake port of a direct injection diesel engine, the passage opening adjustment tool 18 is configured to be able to adjust the opening of the air intake passage 15. A passage opening adjustment device for a spiral intake port of a direct injection diesel engine, characterized in that it is configured to be adjustable and movable toward the 15b side.