Pre-combustion chamber apparatus having changeability

Pre-combustion chamber apparatus having changeability of indirect injection type diesel engine

1 is a view showing a pre-chamber variable apparatus of an indirect injection type diesel engine according to the present invention.

2 is a block diagram showing the control logic of the present invention.

3 is a view showing a conventional indirect injection type diesel engine.

Explanation of symbols for the main parts of the drawing

One : Cylinder head 2 : Cylinder block

3 : Piston 4 : Pre-combustion chamber

5 : Neck part 6 : Fuel injection nozzle

7 : Spark plug 8 : Variable pre-combustion chamber

9 : Piston 10 : Solenoid mechanism

11 : Plunger 12 : Electromagnet

13 : Return spring 14 : Electronic control device

15 : water temperature sensor 16 : rotation speed sensor

17 : Accel position sensor 18 : Atmospheric pressure sensor

<background-art><p>The present invention relates to a prechamber variable device for an indirect injection type diesel engine.</p><p>Diesel engines that have a high compression ratio and use diesel oil as fuel have a direct injection method that directly injects fuel into the combustion chamber of the cylinder and an indirect injection method that injects fuel into the pre-combustion chamber with a pre-chamber communicating with the combustion chamber of the cylinder head. have.</p><p>In the case of the direct injection type engine (DI engine), the price is high, but various control of the combustion control method is possible. It is more advantageous than a direct injection engine.</p><p>However, in the case of the engine 20 of the indirect injection type as shown in FIG. 3 , since the volume of the pre-chamber 21 is improved and the same, when it is in an idle operation (idle operation) state or in a full-load operation state, Since the compression ratio is always the same, for optimal combustion in the entire operation range of the engine, the combustion control method that can reduce the exhaust gas emission is limited because it is necessary to respond only by adjusting the amount of injected fuel and adjusting the fuel injection timing. Despite the advantage of a cheap engine, due to the policy of strengthening regulations, it is almost out of date.</p><p>The reason for this is that a large amount of smoke is generated at low speed and fuel efficiency is lowered at high speed as an attempt is made to achieve optimum combustion using only the change in fuel amount in a state with the same compression ratio over the full-load operation range from idling. The inability to prevent the phenomenon has forced it to fall behind the much more expensive direct-injection engine.</p></background-art><tech><p>The present invention has been proposed in view of the above points, and its purpose is to install a variable pre-chamber connected to the existing pre-chamber so that the compression ratio can be adjusted, thereby enabling adjustment of the compression ratio and the fuel/air mixture ratio, thereby reducing the generation of soot at low speed. An object of the present invention is to provide a prechamber variable device for an indirect injection type diesel engine that can significantly reduce and improve fuel efficiency at high speeds.</p><p>In order to achieve the above object, the present invention is an indirect injection type diesel engine comprising a pre-chamber installed in a cylinder head, and an injection nozzle for injecting fuel into the pre-combustion chamber,</p><p>a variable prechamber installed in communication with the prechamber separately from the prechamber;</p><p>a solenoid mechanism operative to change the volume of the variable prechamber;</p><p>and an electronic control unit (ECU) that controls to reduce or enlarge the volume of the variable pre-chamber by opening and closing the power supply to the solenoid mechanism according to the operating conditions of the engine.</p></tech>

<p>Hereinafter, the configuration of the present invention will be described with reference to the accompanying drawings.</p><p>1 is a view showing a pre-chamber variable device of an indirect injection type diesel engine according to the present invention, and FIG. 2 is a block diagram showing the control logic of the present invention.</p><p>In the drawings, reference numerals 1, 2, and 3 denote a cylinder head, a cylinder block, and a piston, respectively.</p><p>A pre-chamber 4 is formed on one side of the cylinder head 1, and the pre-chamber 4 is configured to communicate into the cylinder through a neck 5 inclined to induce compression and swirl of the combustion gas.</p><p>A fuel injection nozzle 6 and a spark plug 7 are mounted on the upper portion of the pre-combustion chamber 4, and a variable pre-chamber 8 communicating with the pre-combustion chamber 4 is installed on one side of the pre-combustion chamber 4, have.</p><p>The internal volume V of this variable pre-chamber 8 is changed by the movement of the piston 9, and the variable operation is achieved by the solenoid mechanism 10. As shown in FIG. The piston 9 is integrally formed with the tip of the plunger 11 of the solenoid mechanism 10, and the plunger 11 is attracted by the excitation of the electromagnet 12 or a return spring when the magnetism of the electromagnet 12 is erased. It is returned to the original position by the restoring force of (13).</p><p>The solenoid mechanism 10 is operated on/off according to the control of the electronic control device 14, and the electronic control device 14 includes a water temperature sensor 15, a rotation speed sensor 16, an accelerator position sensor 17 and Control of the solenoid mechanism (10) is performed based on the detection information from the atmospheric pressure sensor (18).</p><p>The operation process of the present invention as described above will be described with reference to FIG. 2 .</p><p>When the coolant temperature detected by the water temperature sensor 15 is in a cold start state lower than normal, the electronic control device 14 receives this information and supplies power to the solenoid mechanism 10 to turn it on.</p><p>When power is supplied to the solenoid mechanism 10, the electromagnet 12 is excited, and accordingly, the plunger 11 moves forward. ) moves in the direction of compression to decrease its internal volume (V).</p><p>When the internal volume (V) of the variable pre-combustion chamber 8 is minimized, the compression ratio rises during the compression stroke, and at the same time, the fuel/air mixture ratio is increased, thereby inducing complete combustion and reducing the generation of excessive diesel engine soot in the beginning. will do</p><p>Another driving condition for reducing the internal volume of the variable pre-chamber 8 is when the engine speed detected from the engine speed sensor 16 is in a low speed or idle driving state, the acceleration information detected from the accelerator position sensor 17 is low. When the level is accelerated, and when the atmospheric pressure detected from the atmospheric pressure sensor 18 is low, etc., it is possible to obtain a low-temperature starting effect and a notice compensation effect.</p><p>However, when the coolant temperature detected by the water temperature sensor 15 is high, when the engine operation condition detected by the rotation speed sensor 16 is high speed, when the accelerator position sensor 17 detects that acceleration is in progress, and when the atmospheric pressure sensor 18 When the detected atmospheric pressure is high, the electronic control device 14 controls to cut off the power supply to the solenoid mechanism 10, and accordingly, the piston 9 is retracted and returned by the elastic force of the return spring 13 to return to the variable pre-combustion chamber. The internal volume (V) of (8) is increased.</p><p>When the internal volume of the variable pre-chamber 8 is increased, the compression ratio and the fuel/air ratio are lowered, and there is an effect of improving the fuel efficiency as well as the effect of compensating for the tropical area.</p>

<p>According to the present invention as described above, a variable pre-chamber whose internal volume is changed according to the operating conditions of the engine is provided to communicate with the pre-chamber of a diesel engine, and information detected from a water temperature sensor, a rotation speed sensor, an accelerator position sensor, and an atmospheric pressure sensor. By controlling the solenoid mechanism so that the electronic control device changes the internal volume of the variable pre-chamber, the internal volume of the variable pre-chamber is reduced in idle driving of the engine, cold start, and high-altitude operation with low atmospheric pressure, thereby increasing the compression ratio and fuel/air mixing ratio. The emission of soot from the diesel engine is reduced, and by expanding the internal volume of the variable pre-combustion chamber during high-speed operation of the engine, the compression ratio and the fuel/air mixture ratio are lowered, thereby reducing fuel efficiency.</p>