JP2841473B2 - Engine electromagnetic valve control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic valve control device for an engine that opens and closes intake and exhaust valves by electromagnetic force.

[Conventional technology]

2. Description of the Related Art Conventionally, as an engine for controlling the supply timing of intake air, for example, there is an engine disclosed in Japanese Patent Application Laid-Open No. 55-148892. The engine has a control valve disposed in an intake port or an intake pipe communicating with the intake port, and an adjusting means for adjusting the opening / closing timing of the control valve. By doing so, the fuel consumption rate at partial load is improved. The engine closes the intake and control valves at the end of the intake stroke at full load,
At a partial load, the control valve is closed during the intake stroke and the intake valve is closed at the end of the intake stroke.

As a valve mechanism of an internal combustion engine, for example,
There is one disclosed in Japanese Patent Publication No. 58-183805. A valve mechanism of the internal combustion engine electrically drives an intake valve and an exhaust valve based on a detection signal of a detector that detects an operation state of the internal combustion engine, that is, a detector that detects a rotation state of a crankshaft and a detection signal of an accelerator opening degree detector. It is operated by means.

Further, an electronically controlled engine that controls intake and exhaust valves according to the operating state of the engine is disclosed in, for example, Japanese Patent Laid-Open No. 59-1623.
No. 12 discloses this. The electronically controlled engine controls opening and closing of intake and exhaust valves of the engine by electromagnetic force. The operating state and the atmospheric state of the engine are input, and the intake and exhaust valves are sampled at predetermined crank angles.
Means for determining the opening / closing timing of the exhaust valve, lift characteristics, on / off time ratio, and injection amount of the injector, means for outputting a drive signal to the solenoid of the intake / exhaust valve at every predetermined crank angle, and opening of the intake valve Means for sometimes outputting a drive signal to the injector.

[Problems to be solved by the invention]

By the way, the intake and exhaust cycles of a 4-cycle engine
Generally, as shown by the dotted line in FIG. 2 or FIG. 1, in the intake stroke, at the same time as the intake valve is opened, the piston descends from the top dead center TDC, and air at atmospheric pressure is sucked into the cylinder. . Next, the intake valve is closed, the piston rises from the bottom dead center BDC in the compression stroke, the air-fuel mixture is compressed, and the temperature and pressure rise. Shortly before top dead center TDC at the end of the compression stroke, the air-fuel mixture is ignited or ignited, and moves to a work stroke, ie, an expansion stroke, where the piston is pushed down by high-pressure gas generated by combustion to perform work. Next, the exhaust valve is opened, and the process moves to the exhaust stroke by the upward stroke of the piston, and the exhaust gas in the cylinder is exhausted out of the combustion chamber.

However, at the time of blowdown, when the load of the engine is high, 5 to 6 kg / cm ² of exhaust gas is blown out to the exhaust pipe. However, power loss occurs due to the movement of pushing back pressure in the exhaust stroke of the engine cycle, that is, negative work (second example). Oblique line A in the figure
Part).

By the way, the required performance of the engine is required to be more compact and to have a larger output in the future. Further, the performance of the engine is required to have a high torque at a low speed, an improvement in performance due to an increase in the amount of work, and an improvement in fuel efficiency, that is, no output loss.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems. The intake and exhaust valves are made of a lightweight material such as a ceramic material, and are opened and closed by electromagnetic force to control opening and closing timing and valve lift. The intake and exhaust valves can be controlled independently of the rotation of the crankshaft. With an adiabatic engine, heat is less dissipated even at a partial load, so that the mixture can be burned well even at a low compression ratio. It is an object of the present invention to provide an electromagnetic valve control device for an engine.

The engine, who burned in a low pressure low temperature, because it is effective in reducing emissions, such as NO _X, the pressure at the end intake stroke by controlling the closing timing to close the intake valve before the intake stroke ends It becomes negative pressure, the intake air flow rate is reduced, and combustion is performed in a state where the compression end temperature is low, so that the maximum pressure can be reduced. If the engine is burned in the above condition, the pressure change during the expansion stroke will cause B.C.
In DC, the pressure is close to the atmospheric pressure, and as a result, the work expanding in the exhaust pipe from the blowdown to the atmospheric pressure can be converted into actual work. That is, if the electromagnetic valve control device for an engine according to the present invention is used, the work stroke can be extended and the power loss due to negative work can be reduced.

[Means for solving the problem]

In order to achieve the above object, the present invention provides an electromagnetic valve driving device that opens and closes an intake / exhaust valve that opens and closes a port with respect to a cylinder by electromagnetic force, and detection means for detecting engine load and intake air temperature. The valve of the intake valve for reducing a compression ratio in response to a detection signal whose engine load detection value is equal to or lower than a predetermined load and a detection signal whose intake air temperature detection value is higher than a predetermined temperature. And a controller for closing the intake valve in the middle of the intake stroke and performing control to close the intake valve at a steady timing in response to another detection signal.

In the electromagnetic valve control device for an engine, it is preferable that the valve closing timing during the intake stroke of the intake valve is set to around 50 ° before the end of the intake stroke.

Further, the electromagnetic valve control device of this engine is applied to the opening and closing operation of an intake valve in an insulated engine.

[Action]

The electromagnetic valve control device for an engine according to the present invention is configured as described above, and operates as follows.

This electromagnetic valve control device for an engine responds to an engine load detection value detected by an engine load detecting means that is lower than a predetermined set load, and detects an intake air temperature detected value by a detection means detecting an intake air temperature. In order to reduce the compression ratio in response to the detection signal at or above the set temperature, the valve closing timing of the intake valve is controlled to be closed during the intake stroke, for example, around 50 ° before the end of the intake stroke.

That is, the electromagnetic valve control device of this engine operates at a predetermined low load and at a time when the combustion state is stable at a predetermined temperature or higher, so that the intake valve is closed early by closing the intake valve early to reduce the compression ratio. At the bottom dead center BDC at the beginning of compression by reducing the flow rate, a negative pressure is set, and the maximum pressure during combustion is reduced to expand to almost the atmospheric pressure at the end of the work stroke. Gas energy can be used, and the pressure in the combustion chamber at the bottom dead center BDC at the beginning of the compression stroke and the end of the expansion stroke is reduced to near atmospheric pressure to reduce the back pressure in the exhaust stroke and push the back pressure in the exhaust stroke Reduces power loss due to pumping work.

That is, if the electromagnetic valve control device of this engine is used, the power loss in the area A, which is the motion for pushing out the back pressure in the exhaust stroke shown by the dotted line in FIG. 2 or FIG. 1, is reduced, and as shown in FIG. Thus, the performance of the engine can be improved without losing the workload, and the maximum pressure can be reduced.

In addition, when other signal values of the engine, for example, when the engine is under a high load, the intake valve is closed at a steady time, for example, at a time immediately before the intake valve enters a compression stroke and changes to a positive pressure. The same output as the operation of the engine cycle can be secured.

In addition, since the electromagnetic valve control device of this engine was applied to the opening and closing operation of the intake valve of the heat-insulated engine, the heat-dissipation from the combustion chamber was small when the load was low in the heat-insulated engine. Even before the end of the process, the combustion state can be maintained well even if the intake air amount decreases and the pressure becomes low, so that an extremely optimal engine cycle can be achieved.

〔Example〕

Hereinafter, an embodiment of an electromagnetic valve control device for an engine according to the present invention will be described with reference to the drawings. FIG. 1 shows a PV diagram for a Miller cycle engine incorporating an electromagnetic valve control device according to the present invention.

In FIG. 1, in order to explain the operation cycle of the engine, a change in the gas state in the cylinder in one cycle is shown, and the volume V is plotted on the horizontal axis and the pressure P is plotted on the vertical axis. Here, since the pressure receiving area of the piston is constant, the horizontal axis can indicate the position of the piston stroke.
TDC at top dead center and BDC at top right
Position. The piston stroke is a function of the crank angle, and the pressure P on the horizontal axis is plotted as the crank angle.

The intake / exhaust cycle of a 4-cycle engine of a Miller cycle engine incorporating the engine electromagnetic valve control device will be described.

In the intake stroke of the engine cycle, the intake valves by the electromagnetic valve drive apparatus is opened at point a, in the open state of the intake valve, the piston descends from the top dead center TDC, the intake air from the intake port is the atmospheric pressure P ₀ of the near It is sucked into the cylinder by pressure. During the intake stroke, for example, at around 50 ° (point b in the figure) at the crank angle before the end of the bottom dead center BDC, the electromagnetic valve driving device is operated to close the intake valve. Although the intake valve is closed and intake air is not supplied from the intake port into the cylinder, the piston continues to descend to the bottom dead center BDC.
Decreases and volume V increases to point c. Thus, intake air in the cylinder ends the intake stroke and lower than the atmospheric pressure P ₀ by adiabatic expansion.

Next, the cycle shifts to the compression stroke, but the intake valve and the exhaust valve are closed, and the bottom dead center BD
The piston rises from C. and the cylinder pressure rises from point c to point b.
Along the lines of return to the state of the atmospheric pressure P _0. Intake air in the cylinder, the cylinder pressure is adiabatically compressed along from the point c to a line of the point b is adiabatically compressed up to the point d through the atmospheric pressure P ₀ and temperature and pressure increases. End of compression stroke Top dead center TD
At C., the mixture is ignited or ignited and moves to the work process. Air mixture cylinder pressure in the combustion reaches the highest pressure P _MAX, combustion period along from the point d to a line of the point e terminates. Here, the cylinder pressure of the maximum pressure P _MAX that appears during the combustion period shows a value P ′ _MAX higher than the maximum pressure P _{MAX in} the conventional engine cycle as shown by the dotted line in FIG. In the engine, the maximum pressure can be kept low by reducing the intake air flow and expanding to the bottom dead center BDC.

Next, in the work stroke, that is, the expansion stroke, the piston is pushed down by the high-pressure gas generated by combustion along the line from the point e to the point f to perform work. The work process goes on,
The exhaust gas lowers the piston while burning afterwards, but the end of the work process is almost the atmospheric pressure of the bottom dead center BDC (corresponding to the point f).
It is continued up to the P _0. Therefore, the expansion stroke is completed in a state where the amount of heat dissipated by the self-expansion of the combustion gas generated by the blowdown of the exhaust gas is reduced. Here, the start timing of the exhaust stroke, cylinder pressure, in the conventional engine cycle, as indicated by a dotted line in FIG. 1, the atmospheric pressure P ₀
Although it shows a higher value, in the engine cycle according to the present invention, the cylinder internal pressure returns to almost the state of the atmospheric pressure P ₀ ,
At the point f, the exhaust valve is opened, the exhaust stroke is performed along the line from the point f to the point a, and the exhaust gas that has worked is exhausted into the cylinder, that is, outside the combustion chamber.

By controlling the solenoid valve control device of this engine to advance the closing timing of the intake valve, the power loss (shaded area A in FIG. 2) generated by the motion of pushing out the back pressure during the exhaust stroke in the conventional engine cycle is performed. Alternatively, the negative part of the dotted line in FIG. 1) can be eliminated, and the cycle loss of the engine can be reduced. Moreover, by controlling the closing timing of the intake valve in accordance with the operating state of the engine, operation can be achieved with a good engine cycle. For example, when the combustion state is stable at a partial load of the engine and at a temperature equal to or higher than a predetermined temperature, in order to reduce the compression ratio, the closing timing of the intake valve is advanced to reduce the intake air flow rate, thereby reducing the compression end temperature. Even when the pressure is low, combustion is performed smoothly, the work stroke is extended, the gas energy is converted into work, the exhaust pressure is reduced to near atmospheric pressure, and the bottom dead center at the beginning of the compression stroke and at the end of the expansion stroke. By reducing the pressure inside the combustion chamber at BDC to near atmospheric pressure, the back pressure in the exhaust stroke is reduced, the power loss due to the pumping work that pushes the back pressure in the exhaust stroke is reduced, and the amount of work can be increased.

Also, the electromagnetic valve control device of this engine is extremely preferable when applied to the opening and closing operation of an intake valve of an insulated engine. In an insulated engine, heat dissipation from a combustion chamber at a partial load is small, so that a low compression ratio is used. Even in the state, good operation of the engine can be performed. Moreover, since the maximum gas pressure or P _MAX in the cylinder is kept low as compared to a conventional engine, there is no need also to reinforce the strength in the structure of the engine, the adiabatic engine is the optimal operating cycle.

Next, an example of an electromagnetic valve driving device capable of opening and closing an intake valve and an exhaust valve in the electromagnetic valve control device of the engine will be described with reference to FIG.

As shown in FIG. 3, the electromagnetic valve driving device is incorporated in the engine 13 so as to be applied to an intake / exhaust valve that opens and closes the port 6 with respect to a cylinder. The main part is conceptually shown in a state where it is taken out of the engine 13. The fuel injection device 21 for controlling the fuel supplied to the engine 13 has an injection nozzle 12, which penetrates into the intake port 6 from above the cylinder head 3, and the fuel injected from the nozzle hole flows into the cylinder. Spray is introduced. The fuel injection device 21 is controlled by a command from the controller 15 to inject a predetermined amount of fuel. Further, a rotation sensor 14 is provided for the output shaft of the engine 13 to detect the engine speed. The detected value of the engine speed, that is, the rotation signal is transmitted to the controller 15.
Is input to The intake valve 1 is made of a ceramic material, is guided by a valve guide 16 fixed to the cylinder head 3, and is slidably disposed in a vertical direction.

When the intake valve 1 rises or falls, the valve face 17 of the intake valve 1 is moved to the intake port 6 of the cylinder head 3.
The intake port 6 is opened and closed by coming into contact with or detaching from the valve seat 18 installed in the valve. Therefore, the amount of air taken into the cylinder of the engine 13 is controlled by the opening / closing operation or opening / closing amount of the intake port 6. A mover 19 made of a magnetic material such as soft iron is fixed to an upper end 23 of the intake valve 1, and the mover 19 is provided with a mover coil 24. In addition, a stator 25 made of a magnetic material such as soft iron is mounted on the cylinder head 3 above the mover 19, and the stator 25 is provided with a stator coil 20. . Therefore, when the mover coil 24 and the stator coil 20 are energized / cut off, the stator 25 attracts / separates the mover 19 and drives the intake valve 1 up and down. The valve spring seat 11 and the mover 19 formed on the upper surface of the cylinder head 3
A valve spring 26 is disposed between the valve spring 26 and the valve spring 26. Therefore, the intake valve 1 is normally closed by the spring force of the valve spring 26.

Further, the intake / exhaust valve which is operated by electromagnetic force is made of a ceramic material for the purpose of reducing the weight of the intake / exhaust valve itself, and the valve face 17 of the intake / exhaust valve and the valve stem 2 are formed. In order to prevent iron powder or the like from adsorbing to the sliding portion, it is preferable that the sliding portion is made of a nonmagnetic ceramic material. If iron powder or the like is adsorbed on the sliding portion of the valve face 17 and the valve stem 2, the suction / exhaust valve deteriorates the tightness of the suction / exhaust port, and the frictional resistance of the sliding portion increases, resulting in seizure. An undesired condition occurs. Therefore, in order to operate the intake / exhaust valve by electromagnetic force, a movable element 19 made of a magnetic material is separately provided at the upper end of the intake / exhaust valve. By configuring the intake and exhaust valves as described above, the controlled current from the controller 15 is controlled by the mover coil 24 and the stator coil 20.
When the power is turned on or off, the stator 25 can separate or move the mover 19 against the urging force of the spring 26, so that the intake valve 1 descends or rises and the intake valve 1 The valve face 17 can open or close the intake port 6.

This electromagnetic valve drive is composed of a position sensor 4, a load sensor
5, The controller 15 receives each detection signal detected by the temperature sensor 7 and the rotation sensor 14, and responds to each detection signal detected by the controller 15 to fix the stator coil 20 and the movable coil 24 in the valve lifter 10 of the electromagnetic valve driving device. A current can be supplied to the valve to excite the electromagnet to drive the valve.

The load sensor 5 of the engine 13 detects the engine load, and detects the amount of fuel supplied from the injection nozzle 12 of the fuel injection device 21 to the engine 13 or the amount of depression of the accelerator pedal 28. Can be detected. In other words, the load sensor 5
It can be constituted by a sensor for detecting the amount of fuel supplied to the engine 13 and / or a sensor for detecting the amount of depression of the accelerator pedal 28. Therefore, by inputting a signal of the amount of fuel supplied to the engine 13 and / or the amount of depression of the accelerator pedal 28 to the controller 15 as a load signal of the engine, the amount of fuel absorbed and absorbed
The electromagnetic valve of the exhaust valve can be controlled.

The position sensor 4 of the engine 13 detects the position of the stroke of the piston, and can detect the stroke by detecting the crank angle.

A temperature sensor 7 is provided to detect the temperature of the intake air. Further, an intake flow rate sensor 9 is provided in an intake passage forming the intake port 6. The intake flow rate sensor 9 detects, for example, an air flow hitting a heating wire through an electric current based on a change in the resistance value of the heating wire, and a signal from the intake flow rate sensor 9 is input to an intake flow rate processing device of the controller 15. The amount of intake air passing through the intake port 6 can be detected.

The controller 15 is composed of a microcomputer,
It has a central control unit for performing arithmetic processing, various memories for storing arithmetic processing procedures, control means, etc., input / output ports, and the like. When various signals from the various sensors described above are input, the signals are stored in the memory. The processing is performed according to the above procedure, and a control command is issued to the electromagnetic coils 20 and 24 for the valve operating mechanism for opening and closing the intake valve 1 and the exhaust valve to control the opening and closing of the intake and exhaust valves. In addition, the controller 15
Is configured not only to perform the opening / closing operation of the intake / exhaust valves described above, but also to calculate valve opening, valve lift, fuel injection timing and the like, and to issue a control command. In the figure, reference numeral 27 denotes a battery, which serves as a power source for the controller 15, various valves and other coils. Although only the intake valve 1 is shown in the drawing, this electromagnetic valve driving device is also electromagnetically driven for the exhaust valve, and the configuration of the exhaust system in which the exhaust valve is disposed is connected to the exhaust port. The flow sensor and the injection nozzle are not provided.

Next, the electromagnetic valve driving device that can be incorporated in the engine with the electromagnetic valve driving device is configured as described above, and an example of the operation of the engine with the electromagnetic valve driving device will be described with reference to the drawings. FIG. 4 is a processing flow chart showing an example of the operation of an engine with an electromagnetic valve driving device that can incorporate the electromagnetic valve control device.

In the engine control device according to the present invention, in order to control the valve timing and the like of the intake valve 1 and the exhaust valve in an optimal state, the command from the controller 15 is used.
The operation of each valve lifter 10 of the intake valve 1 and the exhaust valve is controlled by an electromagnetic force. That is, since the valve lifter 10 can be controlled independently of the rotation of the crankshaft, the amount of intake air and the amount of exhaust gas into the combustion chamber 8, the time of intake of intake air into the combustion chamber 8, and the degree of exhaust gas exhaust from the combustion chamber 8 The valve timing of the intake valve and exhaust valve is controlled by the engine
The engine 13 is adjusted to an optimum state according to the rotation speed, and is controlled so that the engine 13 can operate satisfactorily.

With the start of the engine 13, the drive of the electromagnetic valve driving device is controlled, and the intake valve 1 and the exhaust valve are opened and closed. As a first step, by driving the engine 13,
The engine load L _E is detected by the load sensor 5, and inputs a detection signal to the controller 15. Further, the temperature T _A of intake air detected by the temperature sensor 7, and inputs a detection signal to the controller 15 (step 40). Controller 15
Sends a command to each of the valve lifters 10 of the intake valve 1 and the exhaust valve in response to each detection signal, and applies a higher current to the stator coil 20 and the mover coil 24 in each of the valve lifters 10 of the intake valve 1 and the exhaust valve. The following processing is performed to open and close both valves by operating them.

In step 40, it is determined greater than or not a predetermined load L _E1 that the detected engine load L _E is pre-computed by the load sensor 5 (step 41). That is, when the intake valve 1 is closed, when the engine 13 is at a low load and the temperature is high, the piston is closer to the bottom dead center BDC than when the engine 13 is at a high load, that is, 50 hours before the end of the intake stroke. It is preferable to close the valve near ゜ because the compression ratio can be reduced.
In order to control the closing timing of the intake valve 1, the intake valve 1
The load of the engine 13 to be applied when the operating state of the engine 13 changes is set to a predetermined load _LE1 in advance. When the load of the engine 13 is high, the process proceeds to step 43.

Then, it is determined whether the temperature T _A of intake air detected by the temperature sensor 7 is higher than the predetermined temperature T _A1, which is previously calculated (step 42). There immediately, when the intake air temperature T _A in cold or the like is low, the temperature of the combustion chamber even not be maintained too high, the combustion in the low compression ratio is undesirable not smoothly, the intake air temperature T _A When the temperature is lower than a predetermined temperature T _A1 , the intake valve 1 is not closed at an early time to perform combustion at a normal compression ratio. Opening / closing control is performed so that the intake valve 1 is closed at a timing immediately before the pressure changes to a positive pressure after entering the compression stroke.

Engine load L _E is lower than the predetermined load L _E1, and when the intake air temperature T _A is lower than the predetermined temperature T _A1 is electromagnetic in normal valve opening and closing timing of the closing timing of the intake valve 1, the intake valve 1 In order to control the valve operation by electromagnetic force by the valve lifter 10 of the valve driving device, the crank angle, that is, the stroke position of the piston is detected by the position sensor 4 and the detected position is input to the controller 15 (step 43). Furthermore, the valve lifter 10 of the intake valve 1
That is, the drive conditions of the valve drive system are checked (step
44).

If there is no abnormality in the driving conditions of the valve drive system of the intake valve 1, the valve opening timing, valve timing, valve lift amount, valve timing, and the like are determined based on each detection signal detected by the position sensor 4 by the electromagnetic force. The opening time is determined, and opening / closing is controlled by a command from the controller 15 (step 45). It is determined whether or not to continue driving the engine 13 (step 46). If the engine 13 is to be continuously driven, the process returns to the first step 40. If the driving of the engine 13 is to be stopped, the electromagnetic valve is stopped. The control of the driving device ends.

Further, in step 41, it is determined the engine load L _E is smaller than the predetermined load L _E1, and in step 42, when the intake air temperature T _A is determined to be higher than the predetermined temperature T _A1 is It is determined that the engine 13 is in a low load state and the temperature in the combustion chamber is maintained at a predetermined temperature or higher, and the intake valve 1 is closed early to cut the amount of intake air to a low pressure state to change the compression ratio. Therefore, the combustion state of the engine can be maintained sufficiently satisfactorily, so that the closing timing of the intake valve 1 is closed during the intake stroke, for example, around 50 ° before the end of the intake stroke. In order to operate the valve lifter 10, the crank angle, that is, the stroke position of the piston is detected by the position sensor 4.
The detection signal is input to the controller 15 (step 4
7). Further, the driving conditions of the valve lifter 10 of the electromagnetic valve driving device of the intake valve 1, that is, the valve driving system are checked (step 48).

If there is no abnormality in the driving conditions of the valve drive system of the intake valve 1, the closing timing of the intake valve 1 is determined during the intake stroke, for example, based on a detection signal detected by the position sensor 4 by the electromagnetic force. The valve timing, valve lift, and valve opening time for closing around 50 ° before the end of the intake stroke are determined, and opening and closing are controlled by a command from the controller 15 (step 49).

Next, it is determined whether or not to continue driving the engine 13 (step 50). If the engine 13 is to be continuously driven, the process returns to the first stepper 40, and
When stopping the driving of 13, the control of the electromagnetic valve driving device is ended.

〔The invention's effect〕

As described above, the electromagnetic valve control device for an engine according to the present invention includes an electromagnetic valve driving device that opens and closes an intake / exhaust valve with an electromagnetic force, detection means for detecting an engine load and an intake air temperature, and each of the detection means. In order to reduce the compression ratio in response to a detection signal in which the detected engine load value is equal to or less than a predetermined set load and the detected intake air temperature value is equal to or higher than a predetermined set temperature, the valve closing timing of the intake valve is determined during the suction stroke. And a controller for controlling the closing of the intake valve at a steady time in response to another detection signal, so that when the engine is partially loaded and the temperature of the intake air is higher than a predetermined temperature. The intake valve is closed early to reduce the intake air flow to reduce the compression ratio. At the bottom dead center BDC at the start of compression, a negative pressure is applied. The high pressure low, the end point of the power stroke inflated to exhaust pressure near about atmospheric pressure, thereby available stripped gas energy of the conventional exhaust pipe,
At the beginning of the compression stroke and at the end of the expansion stroke, the pressure in the combustion chamber at the bottom dead center BDC is brought to near atmospheric pressure to reduce the back pressure in the exhaust stroke, and the pumping work that pushes the back pressure in the exhaust stroke, that is, by the negative work Power loss can be reduced.

That is, as shown by the area A in FIG. 2 or as shown by the dotted line in FIG. 1, the power loss, which is the motion of pushing back pressure in the exhaust stroke, is reduced, and the work is increased as described above. Improve the performance of

The valve closing timing of the intake valve in the middle of the intake stroke is preferably around 50 ° before the end of the intake stroke, but may be freely changed depending on the engine operating condition in some cases.

In addition, since the maximum gas pressure in the cylinder is reduced as compared with the conventional engine, there is no need to reinforce the structural strength of the engine. For example, it is optimal for an insulated engine.

Further, when other signal values of the engine, for example, when the engine is under a high load or when the engine is cold, control is performed to close the intake valve at a steady time, for example, at a time immediately before entering the compression stroke and changing to a positive pressure. Since the engine is operated in a normal engine cycle by increasing the compression ratio, a satisfactory combustion state can be maintained, and the same output as in the conventional cycle operation can be secured. Therefore, a state in which combustion can be satisfied can be ensured in all regions of the engine operating state, and the engine performance can be improved.

Furthermore, since the electromagnetic valve control device of this engine was applied to the opening and closing operation of the intake valve of an insulated engine, heat dissipation from the combustion chamber during partial load in an insulated engine was small,
Therefore, the combustion temperature is secured, and even before the intake stroke ends, the combustion state can be maintained satisfactorily even when the intake air amount is reduced and the pressure becomes low due to a decrease in the intake air amount, so that an extremely optimal engine cycle can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory diagram for explaining a PV diagram of an embodiment of an electromagnetic valve control device for an engine according to the present invention,
FIG. 2 is a schematic explanatory view for explaining a PV diagram of a conventional engine, FIG. 3 is an explanatory view showing an example of an electromagnetic valve driving device incorporated in an electromagnetic valve control device for an engine according to the present invention, and FIG. FIG. 4 is a processing flow chart showing an example of the operation of the engine control device incorporating the electromagnetic valve driving device. 1 ... intake valve, TDC ... top dead center, BDC ... bottom dead center, 4 ... position sensor, 5 ... load sensor, 7 ... temperature sensor, 10 ... valve lifter (electromagnetic valve drive), 13 ......
Engine, 14 ... Rotation sensor, 15 ... Controller.

Claims (3)

(57) [Claims] An electromagnetic valve driving device for opening and closing an intake / exhaust valve for opening and closing a port with respect to a cylinder by electromagnetic force, detecting means for detecting an engine load and an intake air temperature, and an engine based on the detecting means. In order to reduce the compression ratio in response to a detection signal in which the detected load value is equal to or less than a predetermined set load and the detected intake air temperature value is equal to or higher than the predetermined set temperature, the valve closing timing of the intake valve is set during the suction stroke. And a controller that performs control to close the intake valve at a steady time in response to another detection signal. 2. The electromagnetic valve control device for an engine according to claim 1, wherein the valve closing timing of the intake valve during the intake stroke is set to around 50 ° before the end of the intake stroke. 3. The electromagnetic valve control device for an engine according to claim 1, wherein the electromagnetic valve control device is applied to an opening and closing operation of an intake valve in an insulated engine.