JPH0768905B2 - Engine intake system - Google Patents

Description

TECHNICAL FIELD The present invention relates to an intake device for an engine.

[Prior Art] Conventionally, an engine intake device is not provided with means for suppressing pressure fluctuation of intake pulsation pressure in an intake passage.

[Problems to be Solved by the Invention] Therefore, the above-mentioned conventional technique has the following problems.

Since the pressure fluctuation of the intake pulsation pressure in the intake passage is large and the intake negative pressure increases when the intake pulsation pressure falls, the air supply efficiency to the cylinder chamber decreases and the output performance of the engine is low.

Since the pressure fluctuation of the intake pulsation pressure in the intake passage is large, intake noise is large.

An object of the present invention is to suppress the pressure fluctuation of the intake pulsation pressure.

[Means for Solving the Problems] The present invention is characterized in that an intake device for an engine is configured as follows.

For example, as shown in FIGS. 1 to 3, the intake passage 11 is communicated with the cylinder chamber 2 of the engine 1, the pressure increase / decrease operating chamber 5 of the pressure increase / decrease device 4 is communicated with the intake passage 11, and the pressure increase / decrease device 4 is connected. In synchronization with the crankshaft 6, the pressure increasing / decreasing device 4 is configured to reduce the pressure of the intake passage 11 at the rising timing 8 of the intake pulsation pressure 7 of the intake passage 11 and increase the pressure at the falling timing 9.

The pressure increasing / decreasing device 4 may be, for example, a device for increasing / decreasing the pressure of the intake passage 11 by operating the diaphragm 23 as shown in FIG. 2 or a device for increasing / decreasing the pressure of the intake passage 11 by operating a blanker.

[Effect] The present invention has the following effects.

When the intake pulsation pressure in the intake passage falls, the pressure increase / decrease device increases the pressure in the intake passage to reduce the decrease in intake pulsation pressure.
Since the intake negative pressure is reduced, the efficiency of air supply to the cylinder chamber is increased, and the output performance of the engine can be improved.

When the intake pulsation pressure in the intake passage rises, the pressure increase / decrease device reduces the pressure in the intake passage to reduce the increase in the intake pulsation pressure. Is reduced to reduce the decrease of the intake pulsation pressure, and the fluctuation of the intake pulsation pressure 7 is reduced, so that the intake noise can be reduced.

The pressure booster / depressurizer operates at a speed corresponding to the rotation speed of the crankshaft, and the timing of operation of the pressure booster / pressure reducer is automatically adjusted according to changes in the engine speed, so that the operation of the pressure booster / pressure reducer is It can be performed at accurate timing regardless of the number of revolutions.

[Embodiment] An embodiment of the present invention will be described with reference to the drawings.

1 to 3 are views for explaining an engine air intake device of the present invention. FIG. 1 is a partially longitudinal sectional front view of the engine, FIG. 2 is a partially cutaway side view of the engine, and FIG. 6 is a graph showing a variation of intake pulsation pressure in an intake passage.

In FIG. 1 or 2, reference numeral 1 indicates an engine.

This engine 1 is a multi-cylinder diesel engine, and injects air from an air cleaner (not shown) through an intake passage 11 and an intake port 12 in an intake manifold 10 in order and into each cylinder chamber 2 to inject fuel into a fuel injection pump. The fuel is injected from the fuel injection nozzle 14 by the pumping force of 13 and burned, and the combustion gas is discharged from each cylinder chamber 2 to the exhaust port 15 and the exhaust manifold 16.
The exhaust passage 3 and the muffler 17 in the inside are sequentially passed to be discharged into the atmosphere.

Further, in the intake / exhaust operation, the rotational force of the crankshaft 6 is transmitted in order through the crank gear 18, the idle gear 19, and the valve gear 20, and the intake valve (not shown) and the exhaust valve 21 are opened and closed at predetermined timings. It is supposed to be done.

The intake passage 11 communicates with the cylinder chamber 2 of the engine 1,
The pressure increasing / decreasing working chamber 5 of the pressure increasing / decreasing device 4 is connected to the exhaust passage 11,
The pressure increasing / decreasing device 4 is timed in conjunction with the crankshaft 6, and the pressure increasing / decreasing device 4 reduces the pressure of the intake passage 11 at the rising timing 8 of the intake pulsation pressure 7 of the intake passage 11 shown in FIG. When the intake pulsation pressure 7 in the intake passage 11 is lowered, the pressure increasing / decreasing device 4 causes the intake passage to increase.
The pressure of 11 is increased to reduce the decrease of the intake pulsation pressure 7 to the state of the solid line to the state of the chain line, and the intake negative pressure is reduced.

Therefore, the efficiency of air supply to the cylinder chamber 2 is improved, and the output performance of the engine 1 can be improved.

In addition, as shown in FIG. 3, the intake pulsation pressure 7 in the intake passage 11 is increased.
At the rising timing 8 of the intake passage 3
Is reduced to reduce the rise of the intake pulsation pressure 7 to the state of the solid line to the state of the solid line, and at the time of the decrease 9 of the intake pulsation pressure 7 in the intake passage 11, Increase the intake passage 11 pressure to decrease the intake pulsation pressure 7.
Since the place that should be the state of the chain line is reduced to the state of the solid line and the fluctuation of the intake pulsation pressure 7 is reduced, the intake noise can be reduced.

Further, the pressure increasing / decreasing device 4 is interlocked at a speed corresponding to the rotation speed of the crankshaft 6, and the operation timing of the pressure increasing / decreasing device 4 is automatically adjusted according to the change in the rotation speed of the engine 1. The operation of the device 4 can be performed at an accurate timing regardless of the rotation speed of the engine 1.

The pressure increasing / decreasing device 4 has a pressure increasing / decreasing operating chamber 5 disposed below the interlocking crank 22, and a diaphragm 23 is attached to the upper surface of the pressure increasing / reducing operating chamber 5, and the interlocking crank 22 has a drive shaft 24 and a driven gear 25 on a crankshaft 6. And the diaphragm 23 is interlockingly connected to the interlocking crank 22 via the connecting rod 26, so that the diaphragm 23 is raised at the rising timing 8 of the intake pulsation pressure 7 of the intake passage 11, The intake air in 11 is sucked into the pressure-increasing / decreasing pressure working chamber 5 to reduce the pressure of the intake passage 11, and the diaphragm 23 is lowered at the time 9 of lowering the intake pulsation pressure 7 in the intake passage 11, and then the pressure-increasing / decreasing working chamber 5 is first moved. Intake passage for suctioned intake air 11
The air is discharged to the intake passage 11 to increase the pressure.

[Brief description of drawings]

1 to 3 are views for explaining an engine air intake device of the present invention. FIG. 1 is a partially longitudinal sectional front view of the engine, FIG. 2 is a partially cutaway side view of the engine, and FIG. 6 is a graph showing a variation of intake pulsation pressure in an intake passage. 1 ... Engine, 2 ... Cylinder chamber, 4 ... Increase / decrease device, 5 ... Increase / decrease operating chamber, 6 ... Crankshaft, 7 ... Intake pulsation pressure, 8 ... 7 rise timing, 9 ... The descent time of 7,
11 ... Intake passage.

Claims (1)

[Claims] 1. An intake passage 11 is connected to a cylinder chamber 2 of an engine 1, and a pressure increasing / decreasing working chamber 5 of a pressure increasing / decreasing device 4 is connected to the intake passage 11.
And the pressure increasing / reducing device 4 is timed and interlocked with the crankshaft 6, so that the pressure increasing / reducing device 4 moves the intake pulsation pressure 7 of the intake passage 11 at the rising timing 8 of the intake passage.
An intake system for an engine, characterized in that the pressure of 11 is reduced and the pressure of 11 is increased.