An engine with a plurality of operating modes including operation by compressed air

[0013] In FIG. 1, a piston 10 reciprocating in a cylinder 11 is shown, and a variable-volume combustion chamber 12 is defined by the piston. Two intake valves 13 and 14 control the flow of supercharged air to the combustion chamber 12. The gas flow control valve 15 controls the flow of pressurized air to and out of the pressure vessel 16, as will be described later. The exhaust valve 17 controls the combusted gas to flow out of the combustion chamber from the exhaust passage 18, which exhausts the exhaust gas to the atmosphere. The injector 33 injects fuel into the combustion chamber and also includes a spark plug.

[0014] Each of the four valves 13, 14, 15 and 17 is connected to each of the four hydraulic actuators 19, 20, 21 and 22, which control the four electrically operated valves 23 associated with it one by one. , 24, 25, and 26 will open and close the valves 13, 14, 15 and 17. Each control valve 23, 24, 25, 26 is also connected to a source 27 of pressurized hydraulic oil (for example, a pump) and a discharge device for pressurized liquid (for example, an oil pan from which the pump absorbs liquid). The control valves 23, 24, 25, and 26 are all controlled by electrical signals generated by an electronic controller 29, which also generates a control signal, which is linked to a number of engine operating parameters (by a number of unshown sensors). The detected) correlation is related to the position of the piston 10 in the cylinder 11 detected by the rotation sensor 30 which is connected to the crankshaft 31 and is driven to rotate through the connecting rod 32 connected to the piston 10.

[0015] Each control valve such as 23 can be connected to the upper chamber of an associated actuator such as 19 to receive pressurized liquid from the pump 27, and at the same time connected to the lower chamber of the associated actuator to return the liquid to the oil pan 28, thereby driving the associated valve For example, 13 is open. Each control valve such as 23 can also be connected to the lower chamber of the associated actuator such as 19 to receive the pressurized liquid from the pump 27, and at the same time connected to the upper chamber of the associated actuator to return the liquid to the oil pan 28, thereby driving the relevant The valve, for example, 13 is closed.

[0016] An engine provided with pistons 10 and cylinders 11 will have, for example, three other cylinders, each of which has respective reciprocating pistons, all of which are connected to a common crankshaft 31, and each cylinder has the above-mentioned hydraulic pressure. The valves are actuated, all of which are controlled by a common electronic controller 29.

[0017] The use of the above-mentioned engine in automobiles will now be explained.

[0018] Under normal operating conditions, each cylinder of the engine will operate according to a standard four-stroke. During the intake stroke, the intake valves 13 and 14 are opened to allow charge air to enter the combustion chamber with the injector 33, which injects fuel into the received air, and then injects the fuel in the following compression stroke The mixture with air is compressed, and then the spark plug 33 is ignited, and the ignited gas is expanded during the power stroke, and the exhaust valve 17 is then opened during the exhaust stroke to allow the combusted gas to be discharged from the combustion chamber. The controller 29 keeps the gas flow control valve 15 closed during the entire process of the four-stroke operation.

[0019] In the partial load/low load state, only two of the four cylinders operate in the above-mentioned manner according to the standard four-stroke. The other two cylinders, such as cylinder 11, become compressors which will now be described. First, the controller 29 detects whether there is a suitable partial load condition based on the received signal. The controller 29 will then control the actuators 19, 20, 21, 22 so that the intake valves 13 and 14 are opened during each downstroke of the piston 10 to allow air to be drawn into the combustion chamber 12. The injector 33 remains inactive to pressurize the pressurized clean air in the combustion chamber 12 in each upstroke of the piston 10. Next, the controller 29 opens the gas flow control valve 15 during the upward stroke so as to allow the pressurized air in the combustion chamber 12 to be discharged into the pressure vessel 16 storing the pressurized gas.

[0020] When the engine is operated with two cylinders of compressed air, each of the remaining cylinders operating according to the four-stroke operation starts the compressed air cylinder. By making the combustion cylinder work harder, NO x Compared with the hydrocarbon emissions, all cylinders are operated under standard four-stroke operation at part load. The electronic controller 29 will estimate how much power output is required based on the engine under the given operating conditions, and then determine whether the required power can be provided by operating a partial number of cylinders.

[0021] When the engine is decelerating and the engine needs to be braked, then the electronic controller 29 can change all the cylinders to another mode, in which they operate as the above-mentioned compressors, each in each downstroke The piston sucks in air, pressurizes the air in the subsequent upward stroke, and then discharges the pressurized air into the pressure vessel 16. The momentum of the vehicle provides energy for the compression of air. The compression of air absorbs the kinetic energy of the vehicle, so this makes the vehicle slow down very effectively.

[0022] The pressure sensor 34 measures the gas pressure in the combustion chamber 12. The pressure sensor 35 measures the pressure of the compressed air stored in the pressure container 16. The pressure sensors 34 and 35 transmit the measured signals to the electronic controller 29. When the pressure of the compressed air in the variable-volume combustion chamber, for example 12, is greater than the pressure in the pressure vessel 16, the electronic controller 29 only opens each gas flow Control valve such as 15. Then when the container 16 is fully pressurized, the electronic controller 29 keeps the gas flow control valve such as 15 closed, and as the air is trapped, all the intake and exhaust valves of a specific cylinder are also kept closed, where the variable The volumetric combustion chamber acts as a gas spring (when, for example, two cylinders are active and the other two cylinders are inactive, this is preferable in a partial load condition), or alternatively, the electronic controller 29 will operate to open the intake valve And an exhaust valve to allow the air to be compressed, and then the compressed air is discharged to the exhaust device (this is preferable when the vehicle is decelerating). In addition, compressed air can be discharged into the atmosphere through the intake system under the control of intake valves such as 13, 14 because it is clean air. This has the advantage of avoiding cold air passing through the catalytic converter in the engine exhaust system (this will have an effect on the temperature of the catalytic converter falling below its operating temperature.)

[0023] Preferably, the vehicle on which the engine is operating has an automatic transmission. Therefore, during the braking process of the vehicle, the gearbox will automatically change to the low speed ratio or the lowest speed ratio, thereby increasing the rotation ratio, so that the work of compressed air is completed and thus regenerative braking is achieved. Since the speed ratio changes continuously with the speed of the vehicle, a continuously variable gearbox would be ideal. Electric drive can be used, but any automatic gearbox is sufficient.

[0024] In the case of a four-wheel drive gearbox, if the energy transfer rate exceeds the force required to lock the wheels of one of the axles, the braking energy can still be distributed between the other axles and the engine acting as a compressor. The continuously variable gearbox can also be configured to change the gear ratio in order to deliver more regenerative braking power when the brake is applied (under the control of the electronic control system).

[0025] When the engine works as a compressor during braking, two strokes are used. In each downward stroke of the piston in the cylinder, air is drawn into each working cylinder, and in each upward stroke of the piston in the cylinder, Compressed air is discharged from each working cylinder.

[0026] Once the stored compressed air has accumulated in the pressure vessel 16, the compressed air can be used to start the engine. This may be possible when the vehicle is initially started or when the vehicle is traveling slowly along traffic conditions. In this mode of operation, the engine will operate as a pneumatic engine and the controller 29 will close the intake valve (e.g. 13, 14) of each cylinder, and then will control the opening and closing of the gas flow control valve 15 and the exhaust valve 17 Closed, so that compressed air is allowed to enter the combustion chamber 12 from the pressure vessel 16 to push the piston 10 downward, and then the expanded gas is discharged from the combustion chamber 12 to the exhaust device 18 in the subsequent upward stroke. Alternatively, the clean expanded gas can be exhausted to the atmosphere via the intake system under the control of intake valves such as 13, 14.

[0027] Since the stored energy of the compressed gas is permanently available, in order to start the vehicle during operation, it is ideal to use the compressed gas during the starting of the engine. This will help to improve emissions, as emissions are usually poor during engine startup. In addition, the stored compressed gas allows the vehicle to start without clutch. However, before the internal combustion engine drives the vehicle, the internal combustion engine must be allowed to burn and rotate. When compressed air is used to drive the piston during the start-up process, the piston of the engine can be connected to the drive shaft, so no clutch operation is required.

[0028] It must be taken into account that when the vehicle starts from a standstill, the engine may be operated so that it starts in pneumatic mode and then transitions to a low-load state, in which two cylinders can be pneumatically operated, and the other two can be four-stroke by the internal combustion engine Operate, and then all cylinders operate in four strokes as the vehicle accelerates.

[0029] The use of the engine of the present invention can eliminate the need for the engine to run idling. When the vehicle stops, the engine stops. When the vehicle needs to start moving again, the engine can first be operated in a pneumatic mode, as described above. All in all, this eliminates the idling of the engine and makes the fuel efficient.

[0030] The electronic controller 29 will continue to monitor the level of gas stored in the pressure vessel 16 and will change the operation of the engine to provide compressed gas to the pressure vessel whenever it notices that the stored gas supply is exhausted.

[0031] It is to be considered that the container 16 is a lightweight plastic pressure container which will contain 10-20 bar of compressed air. The size of the container is such that the stored compressed gas is sufficient to enable the vehicle to travel 3-5 miles. A typical container can store 140 liters of compressed air.

[0032] In a variant of the above system, the second pump can be used to increase the pressure of the compressed gas from the 20 bar provided when the engine is operating in pneumatic mode to 200 bar. However, this involves additional complexity, as there must be a heavier storage container (e.g. steel) and an independent compressor driven by the engine must be used.

[0033] Another purpose of the second pump is to increase the air pressure after the air is output from the cylinder, and before the air is compressed in the cylinder of the engine, the engine-driven supercharger (or the electronically driven supercharger) can be used to compress the air.

[0034] In the above-mentioned operation of the engine started by compressed air, each working cylinder has been described as running two strokes, where the compressed air expands the gas with each downstroke of the piston in the working cylinder, and the expanded gas follows The piston is discharged every upstroke in the working cylinder. However, a four-stroke can be used for each working cylinder, where the intake valve opens during the intake stroke, and then the supercharged air introduced via the intake valve is compressed during the compression stroke, and then the pressurized gas is introduced during the power stroke Work the cylinder and expand. Finally, the expanded gas exits the working cylinder during the exhaust stroke, either through the exhaust valve or enters the intake system through one or more intake valves. The use of four strokes can increase the efficiency of the engine.

[0035] The pressurized gas stored in the pressure vessel can be burned in the cylinder instead of being expanded, and a direct fuel injection system is provided for it, in which fuel is directly delivered to the working cylinder to mix it with the air in the cylinder. This has the ability to enhance performance from the original position of the vehicle started by the engine of the present invention. Moreover, if the engine is a turbocharger, the use of pressurized gas from the container can reduce the lag typically caused by a turbocharger engine. In order to allow this possibility, the engine needs to operate in a four-stroke, in which in each intake stroke, supercharged air is introduced into the cylinder from a pressure vessel of pressurized air via a gas flow control valve. The full charge air can be provided from the container, or alternatively, the intake valve is opened at the beginning of the intake stroke, and then as the gas flow control valve opens in the latter part of the intake stroke, the intake valve Close to introduce air at boost pressure. The intake valve and the gas flow control valve will not be opened at the same time. When all the charge air comes from the pressure vessel of the charge gas, the intake valve remains closed during the entire process of each intake stroke.

[0036] Using multi-cylinder cylinders can achieve double (or triple) compression and expansion. If these cylinders are connected in an appropriate manner through their external pipes, the air can be compressed to the first level in the first cylinder, then compressed to the second level in the second cylinder, and then in the third The air is compressed to a higher level in the cylinder. Similarly, the compressed air from the container can be expanded to a first degree in one of the cylinders, and then discharged as the discharged gas expands again to a higher second degree in the other cylinder, and finally, twice The discharged gas expands to the third degree again in another cylinder. This is only possible in engines with pistons that move in phase with respect to each other in a specific way, but will increase efficiency when possible.

[0037] Although it has been described above that the present invention can be implemented in a piston engine, the present invention can also be used in any rotating device such as a rotary engine (like a Wankel engine) or any other variable having a combustion chamber or compression chamber can be used. Volumetric cavity engine. Therefore, in the case of a rotary engine, the "stroke" involved in the description and claims should be understood as including the time to increase the volume of the combustion chamber in the engine and the time to decrease the volume of the combustion chamber in the engine. There is no piston sliding. "Downstroke" should be understood to include the time to increase the volume of the variable volume combustion chamber in a pistonless engine. "Upstroke" should be understood to include the time to reduce the volume of the variable volume combustion chamber in a pistonless engine.

[0038] Compared with a vehicle driven by the engine of the present invention and a vehicle driven by a combination of an internal combustion engine and an electric motor, the structure of the present invention is simpler. There is no need for generators or motors or batteries. Each of these items is also expensive, so the present invention has the advantage of lower cost.

[0039] image 3 The preferred valve mechanism used in the above-mentioned internal combustion engine is shown to control the flow rate of pressurized gas from the variable volume combustion chamber (for example, 12) to the pressure vessel 16.

[0040] The key is to provide a valve mechanism to control the flow of pressurized gas without having to use a high spring load, so that the poppet valve ( image 3 115) to shut out the air pressure acting on the back of the valve head 115A.

[0041] The valve mechanism includes a balance piston 116 which is mounted on the valve stem 115 and moves together with the valve stem. The balance piston 116 can slide in the valve stem cavity 117 provided on the cylinder head 118. The spring 119 is arranged in the valve stem cavity 117 and acts between the lower surface of the cavity 117 and the balance piston 116 to bias the poppet valve 115 to a position close to the delivery port to prevent air from entering the combustion chamber 112 and the air storage ( image 3 Not shown in) flow between.

[0042] In addition from image 3 It can be seen that in order to open the valve stem 115 to allow air to flow between the combustion chamber 112 and the air reservoir along the delivery passage 121, the actuator piston 120 of the hydraulic actuator strikes the end of the valve stem 115. It can be seen from this figure that the seal 122 prevents air from flowing out of the valve stem cavity 117 through the balance piston 116.

[0043] The valve stem cavity 117 is connected to the delivery channel 121 via a connection channel 123, and an isolation valve 124 is provided in the connection channel. The operation of the isolation valve 124 is controlled by an electronic controller (not shown in the figure).

[0044] The force acting on the back surface of the valve head 115A is equal to the product of Px (VS supply pressure) and the back surface area of ​​the poppet valve 115, that is, Av. This force is counteracted by the balancing force applied to the balancing piston 116 in the valve mechanism. This balancing force is the product of the supply pressure Px and the area Ap. of the balancing piston. Therefore, the area Ap. of the balance piston is selected to be equal to or substantially equal to the area Av. Therefore, the force acting on the balance piston 116 cancels or substantially cancels the force on the back of the poppet valve 115.

[0045] Since the force balance is adopted in the valve mechanism, a small valve spring force can be used, so the poppet valve 115 can be operated almost without the action of a hydraulic actuator.

[0046] in image 3, An isolation valve 124 is shown. The valve can be used to maintain the air pressure in the valve stem cavity 117. It can be used to change the balance between the opening force applied to the valve head 115A and the valve closing force acting on the underside of the balance piston 116. However, this isolation valve is optional. It can make the pipe 123 maintain a permanent connection between the valve stem cavity 117 and the delivery channel 121, so the same pressure is always applied to the back of the valve head 115A and the balance piston 116 .

[0047] As mentioned above, two airtights 122 are required. One of the seals slides at the interface between the balance piston 116 and the surrounding cavity. The other seal is fixed in the assembly consisting of the poppet valve 115, the valve lock plate 125 and the balance piston 116.

[0048] image 3 The main advantage of the valve mechanism in is that enabling the hydraulic actuator 120 to overcome the preload of the spring 119 to open the valve requires lower hydraulic pressure (and therefore requires less power). Therefore, more energy is saved (for example, during braking) without causing waste in the hydraulic actuation system.

[0049] As described above, when the pressure Pp in the cylinder 112 is equal to the gas pressure Px in the delivery passage 121, the poppet valve 115 will ideally open, thereby minimizing throttling (and therefore pumping) loss, and thus saving energy to the greatest extent .