JPH0689660B2 - Engine with extraction / pressurization mechanism - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an engine with an extraction / pressurizing and pushing mechanism that promotes combustion of the engine, improves output, and improves durability of the engine.

[Conventional technology]

In order to improve the output of the engine and improve the durability, it is necessary to increase the average pressure in the cylinder and keep the maximum pressure low during the period when the engine does work. It is effective to accelerate and shorten the combustion period. Then, conventionally, various measures have been taken to promote combustion.

In particular, in a diesel engine, fuel is directly injected into the combustion chamber, so it is necessary to promote the mixing of combustion and air.Therefore, special measures are taken in the shape of the combustion injection device, the combustion air supply device, or the combustion chamber to burn the fuel. Turbulence is generated in the indoor air.

For example, in a fuel injection device, there is known a method of injecting fuel at a high pressure exceeding several hundreds of atmospheric pressure to atomize the fuel and generate a strong turbulent flow in the air in the combustion chamber due to high-speed movement of the fuel particles. ing.

As for the combustion air supply device, there is known a system in which the intake port and the intake valve have a special shape, a swirling motion is given to the air in the combustion chamber, and the swirling motion is used for mixing fuel and air.

As for the shape of the combustion chamber, a method of providing a squish area in a direct injection diesel engine is used.

[Problems to be solved by the invention]

However, in the method of injecting fuel at high pressure among the above-mentioned conventional methods, turbulent flow is attenuated at the end of fuel injection, and sufficient turbulent flow is obtained in the time required for turbulent flow after fuel injection. Have a problem that can not be.

Further, the above-mentioned method of improving the combustion air supply device inevitably has a problem that the resistance to the air flow increases and the intake air amount decreases.

The method of providing the squish area has a problem that the turbulent flow is generated only at around the top dead center of the piston.

The present invention solves the above problems, and provides an engine capable of promoting combustion by generating turbulence at the timing of combustion and simultaneously supplying additional oxygen. Is.

[Means for solving problems]

In the engine of the present invention, the extraction valve and the high pressure gas valve are provided in communication with the combustion chamber of the engine, and the high pressure gas generator is provided in communication with the extraction valve, and the high pressure gas generator and the high pressure gas valve are connected to each other. A heat exchanger is provided between the compressed air extracted through the extraction valve during the compression stroke of the engine and further pressurized by the high pressure gas generator, and the compressed air is heated to an appropriate temperature by the heat exchanger. After the control, it is characterized by causing the combustion chamber of the engine to recirculate via a high pressure gas valve.

[Action]

In the present invention, the high-pressure gas valve can be opened and closed during the combustion period to push high-pressure pressurized air into the combustion chamber during combustion, and turbulent flow can be generated in the combustion chamber at the most effective time for combustion. , It is also possible to supply additional oxygen at the same time, promote combustion, and increase the average pressure in the cylinder.
The maximum pressure is kept low to improve output and durability.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of an engine with an extraction / pressurizing and pushing mechanism according to the present invention.

The engine 1 comprises a combustion chamber 9 surrounded by a cylinder 11 and a piston 12 arranged so as to make a reciprocating motion in the cylinder 11, and communicates with the combustion chamber 9 so that one or several intakes are provided. A port and an exhaust port are provided, and an intake valve or an exhaust valve is arranged at each port. In the present invention, the pressurized air pushing port 3 and the bleeding port 14 are provided separately from the intake port and the exhaust port, and the high pressure gas valve 4 and the bleeding valve 5 are arranged in the ports 13 and 14, respectively.
The high pressure gas valve 4 and the extraction valve 5 are electromagnetic valves. The extraction port 14 is connected to the pump chamber 10 of the high-pressure gas generator 2, and the pump chamber 10 is connected to the pressurized air pushing port 13 via the control valve 7, the check valve 8 and the heat exchanger 3. Further, the pump chamber 10 is provided with a relief valve 6 composed of an electromagnetic valve. As the high-pressure gas generator 2, a compressor driven by utilizing a part of power generated by the engine 1 is used. Alternatively, a compressor driven by using other power may be used.

The operation of the engine 1 of the present invention is divided into three operation modes according to the usage mode of the high pressure gas generator 2, the high pressure gas valve 4, the bleeding valve 5, and the relief valve 6.

The first mode is a feature of the engine 1 of the present invention, and is a case where the engine 1 is operated at a relatively high load and is a bleed / pressurize pushing mode,
The second mode is a normal engine operation mode in which neither bleeding nor pressurization is performed, and the third mode is a case where the engine is operated at a relatively low load and only bleeding and escape are performed.

When operating in the extraction / pressurization pushing mode, which is the first operation mode, the cylinder 11 compressed in the compression stroke is used.
A part of the air therein is extracted by opening the extraction valve 5, introduced into the pump chamber 10 of the high-pressure gas generator 2, and pressurized in the pump chamber 10. Since the air introduced into the pump chamber 10 is the air compressed in the compression stroke of the engine 1 as described above, it is introduced at a high pressure of about 40 atm.
It is possible to easily pressurize the pump chamber 10 to a high pressure of over 200 atm. The air pressurized in the pump chamber 10 to the set pressure of the pressure regulating valve 7 opens the pressure regulating valve 7 and the check valve, and is discharged to the heat exchanger 3. The discharged air exchanges heat with a refrigerant or the like in the heat exchanger 3, the temperature is adjusted, and the air is stored at a predetermined pressure and temperature. The high-pressure gas valve 4 opens at a predetermined engine rotation angle during the combustion period of the engine 1, high-pressure air is recirculated to the combustion chamber 9 during the combustion period, and a strong turbulent flow occurs in the combustion chamber 9 and oxygen is generated. It is replenished and combustion is accelerated.

In order to reduce the load on the high-pressure gas generator 2 and to introduce a sufficient amount of air into the pump chamber 10, it is effective to provide an intercooler between the extraction valve 5 and the pump chamber 10. Further, the function of the pressure regulating valve 7 can also function as the check valve 8, and in that case, the pressure regulating valve 7 need not be provided.
Moreover, the pressure of the air in the heat exchanger 3 can also be controlled by controlling the extraction valve 5 and the high-pressure gas valve 4, and the pressure regulating valve 7 is not necessary in this case as well.

In the second operation mode, the extraction valve 5 and the high pressure gas valve 4 are both closed, the high pressure gas generator 2 is not operated, and the engine is operated in a conventionally well known mode.

Next, in a third operation mode in which the engine is operated at a relatively low load, the high pressure gas valve 4 is closed, the predetermined rotation angle extraction bleed valve 5 and the relief valve 6 of the engine 1 are opened and closed, and the engine 1 and the high pressure are released. The air pressurized by the gas generator 2 is released to the exhaust pipe through the relief valve 6, the compression work of the engine 1 is reduced, and the efficiency of the engine is improved.

FIG. 3 shows an engine operation mode map which is divided into three regions according to the engine load and the engine rotation speed and executed in each region.

In the region A where the engine load is relatively high between the line I and the line II, the engine 1 is operated in the first extraction / pressurization pushing mode, and high-pressure air is pushed into the combustion chamber 9 during the combustion period. As a result, combustion is promoted and high engine output is obtained. In the region B between the line II and the line III, the second normal operation mode is operated. In the region C where the engine load is small, which is shown below the line III, the engine 1 is operated in the mode in which only the third extraction and escape are performed, the friction of the engine 1 is reduced, and the engine 1 is operated efficiently. It should be noted that a plurality of maps are prepared as the engine operation mode maps so that different maps can be used according to changes in the accelerator opening.

FIG. 4 shows whether or not the control for selecting the operation mode according to the engine load and the engine rotation speed (hereinafter, referred to as "rotation / load control") is executed depending on whether the engine temperature is high or low. In order to protect the engine 1, when the engine temperature is low, such as during cold start, and when the engine temperature is high, such as when the engine 1 is operating in an overload condition, Do not execute control.

FIG. 2 shows a control circuit used to control the engine 1 of the present invention as shown in FIGS. 3 and 4, and includes a high pressure gas valve 4 and a bleed valve which are solenoid valves. 5,
The opening / closing timing of the relief valve 6 is optimized.

A signal indicating whether each of the high-pressure gas valve 4, the bleeding valve 5, and the relief valve 6 is open or closed is input to the CPU and stored therein. Further, a signal indicating the engine speed and a signal indicating the engine load are input to the CPU, and the current operating state of the engine 1 is in any one of the three regions A, B, C shown in FIG. It is decided whether there is. A signal indicating the cooling water temperature corresponding to the engine temperature is input to the CPU, and it is determined whether or not the temperature of the engine 1 is in a condition for executing control by rotation / load.

If the engine temperature is at a stable temperature of the engine 1 in a steady operation state and the region determined by the engine load and the engine rotation speed is in the region A of FIG. 3, the high pressure gas generator 2 is driven, The opening / closing time of the high pressure gas valve 4 and the extraction valve 5 is determined based on the rotation angle signal of the engine 1 input to the CPU, and the opening / closing signal is output to the high pressure gas valve 4 and the extraction valve 5 to control by rotation / load. Is executed. That is, the extraction valve 5 is opened and closed in the compression stroke of the engine, and a part of the compressed air is extracted and introduced into the pump chamber 10 of the high-pressure gas generator 2. Further, the high pressure gas valve 4 is opened and closed during the combustion period of the engine, and the air pressurized to a high pressure is pushed into the combustion chamber 9. A signal indicating the temperature and pressure of the air supplied to the engine 1, that is, an intake air temperature and an intake pressure is input to the CPU, and the period in which the bleeding valve 5 is opened is corrected based on the signals indicating the temperature and the pressure. The amount of air introduced into the pump chamber 10 of the high-pressure gas generator 2 is controlled to an appropriate amount according to the state of the air supplied to the cylinder 11 of the engine 1. Next, when the region determined by the CPU based on the signal indicating the engine rotation speed and the engine load is in region B of FIG. 3, or the engine determined based on the signal indicating the temperature of the cooling water. When the temperature of 1 is lower than or higher than the normal steady operating temperature, a signal for closing the high pressure gas valve 4, the extraction valve 5, and the relief valve 6 is output. Further, the high pressure gas generator 2 is not operated.

CP depending on signals indicating engine speed and engine load
When the region determined by U is the region C below the line III in FIG. 3, a close signal is output to the high pressure gas valve 4, and the bleeding valve 5 and the relief valve 6 are driven by the engine rotation. An opening / closing signal synchronized with the angle is output to perform proper bleeding and escape.

A signal indicating the accelerator opening is also input to the CPU, and in response to changes in the accelerator opening, the operation mode map described in FIG. 3 is changed, a new operating area of the engine 1 is determined, and the driver's intention is changed. For example, optimal control is performed in accordance with acceleration-oriented or deceleration-oriented.

FIG. 5 is a diagram showing a change in the pressure in the cylinder 11 of the engine 1 with respect to the engine rotation angle of the engine 1. The pressure change of the engine 1 of the present invention is shown by a solid line to show the pressure change of the engine conventionally used. It is indicated by a broken line. The period indicated by a is a period in which the bleeding valve 5 is open and bleeding is performed, the period indicated by b is a period in which pressurized air is pushed in, and the period indicated by c is Combustion chamber 9
It shows the combustion period within. In the engine 1 of the present invention, the combustion period c is the combustion period c ′ of the conventional engine.
Further, the pressure of the engine 1 of the present invention is slightly lower than the pressure of the conventional engine during the period of bleeding, and the average pressure during combustion is equal to that during combustion of the conventional engine. It can be seen that the pressure of the engine 1 of the present invention is lower than that of the conventional engine with respect to the maximum pressure and the maximum pressure.

As described above, in the engine 1 of the present invention, the combustion in the combustion chamber 9 can be controlled, and the average pressure in the cylinder 11 can be reduced while reducing the maximum pressure in the cylinder 11 that affects the durability of the engine 1. By maintaining a high level, it is possible to increase the work amount, that is, to obtain a high output.

The present invention can also be applied to an engine equipped with a supercharger, and the high-pressure gas generator 2 can be used as a gas generator for an exhaust brake.

〔The invention's effect〕

As described above, according to the present invention, the extraction air 5 and the high-pressure gas valve 4 are provided in communication with the combustion chamber 9 of the engine, and the high-pressure gas generator 2 is provided in communication with the extraction valve 5, and the high-pressure gas is provided. A heat exchanger 3 is provided between the generator 2 and the high pressure gas valve 4.
The compressed air extracted through the extraction valve 5 during the compression stroke of the engine is further pressurized by the high pressure gas generator 2 and the pressurized air is controlled by the heat exchanger 3 to an appropriate temperature. Since it is recirculated to the combustion chamber 9 of the engine 1 via the high pressure gas valve 4, turbulent flow can be generated in the combustion chamber 9 at the most effective time for combustion, and at the same time, additional oxygen can be supplied. The combustion is promoted, the average pressure in the cylinder 11 is increased, and the maximum pressure is suppressed to be low, so that the output is improved and the durability is improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an engine with an extraction / pressurizing and pushing mechanism of the present invention, and FIG. 2 is a control circuit for optimizing the opening / closing timing of a solenoid valve used in the engine of the present invention. FIG. 3 is a diagram showing an example, FIG. 3 is a diagram for explaining an engine operating mode executed in each region by dividing the engine operating region into three regions according to the engine load and the engine rotation speed, and FIG. 4 is an engine. FIG. 5 is a diagram showing a region where control by rotation / load is applied to temperature, and FIG. 5 is a diagram showing pressure in a cylinder with respect to a rotation angle of an engine. 1 ... Engine, 2 ... High-pressure gas generator, 3 ... Heat exchanger, 4 ... High-pressure gas valve, 5 ... Exhaust valve, 6 ... Escape valve, 7 ... Control valve, 8 ... Check Valve, 9 ... Combustion valve, 10 ...
… Pump chamber, 11 …… Cylinder, 12 …… Piston, 13 ……
Pressure pushing port, 14 …… Bleed port.

Claims (1)

[Claims] 1. An extraction valve and a high-pressure gas valve provided in communication with a combustion chamber of an engine, a high-pressure gas generator installed in communication with the extraction valve, a high-pressure gas generator and the high-pressure gas valve. And a heat exchanger provided between the bleeding valve and the bleeding valve, and the compressed air extracted through the bleeding valve during the compression stroke of the engine is further pressurized by the high-pressure gas generator, and is pressurized. An engine with a bleed / pressurizing mechanism that recirculates air to the combustion chamber of the engine via a high-pressure gas valve.