CN110671200A

CN110671200A - Plunger type compression ratio variable control system of engine

Info

Publication number: CN110671200A
Application number: CN201910781740.6A
Authority: CN
Inventors: 王明中
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-08-14
Filing date: 2019-08-14
Publication date: 2020-01-10

Abstract

The invention relates to the field of fuel oil engines, in particular to a variable compression ratio system of an engine, which comprises a variable pressure cylinder and a driving device, wherein the variable pressure cylinder is arranged on the top end of a cylinder cover, a variable pressure plunger is arranged in the variable pressure cylinder, a thread groove is arranged on the variable pressure plunger, a thread is arranged on a transmission screw, the lower end of the transmission screw enters the thread groove of the variable pressure plunger, the top end of the transmission screw is connected with a stepping motor, the transmission screw is driven to rotate by the stepping motor, when the system works, a gas pressure sensor detects the inlet pressure and inputs a signal into a controller, the controller drives the stepping motor to ensure that the lower end of the transmission screw upwards pulls the variable pressure plunger out of the variable pressure cylinder when the transmission screw rotates forwards, the lower end of the variable pressure cylinder can form a gas pressure regulating chamber, and the system enables the compression ratio of gas to be changed through the lifting motion of the, thereby enabling a controllable control of the compression ratio.

Description

Plunger type compression ratio variable control system of engine

Technical Field

The invention relates to the field of fuel engines, in particular to a variable compression ratio system of an engine.

Background

The existing solution is a variable compression ratio technology, the working principle is that a wedge-shaped sliding block is arranged between a cylinder body and a cylinder cover, so that the relative position of a combustion chamber and the top surface of a piston is changed, thereby changing the compression volume and the compression ratio, but the structure is complex, the positions and the shapes of the cylinder body and the cylinder cover need to be changed, and the engine is not beneficial to the manufacturing of the engine and the later maintenance operation.

The second scheme of the prior art is that an eccentric ring is added into a big end of a crankshaft connecting rod and is controlled to rotate through a gear, so that the top dead center position of a piston is changed, the compression ratio is changed, but the processing requirement of the technology on a crankshaft is high, the mechanism for connecting the crankshaft with the eccentric ring is complex, the crankshaft and the gear and the mechanism for connecting the eccentric ring inside the crankshaft are easily damaged due to insufficient strength when the crankshaft rotates at a high speed, the maintenance and replacement cost is high, and the later-stage application is not facilitated.

The third scheme of the prior art is that a set of multi-link mechanism and a control shaft are additionally arranged on an original crank-link mechanism, the position of the multi-link mechanism changes to change the position of the top dead center of a piston, but the mechanism needs an additional linkage structure to drive, the structure is more and large, the volume and the weight of an engine can be increased when the multi-link mechanism is applied to a multi-bar engine, the variable end of the multi-link mechanism is arranged on a crankshaft, and extra unbalanced vibration can be caused when the crankshaft runs at a high speed, so that the overall strength of the mechanism is reduced, the comfort of a vehicle is reduced, and the multi-link mechanism is not beneficial to large-batch application.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a plunger type compression ratio variable control system of an engine, which comprises a variable pressure device and a control device, wherein the variable pressure device and the control device are arranged on a cylinder cover, the variable pressure cylinder is arranged at the top end of the cylinder cover, a variable pressure plunger is arranged in the variable pressure cylinder, a thread groove is arranged on the variable pressure plunger, a thread is arranged on a transmission screw rod, the thread is matched with the thread of the thread groove in the variable pressure plunger, the lower end of the transmission screw rod enters the variable pressure plunger, the top end of the transmission screw rod is connected with a stepping motor, the transmission screw rod is driven to rotate by the stepping motor, when the system works, a gas pressure sensor arranged on an air inlet channel detects the air inlet pressure, when the air inlet pressure reaches a set value, the pressure sensor inputs a, when the stepping motor drives the transmission screw to rotate forwards, the lower end of the transmission screw pulls the variable pressure plunger upwards out of the variable pressure cylinder, the lower end of the variable pressure cylinder can form a gas pressure regulating chamber, air entering the cylinder from the air inlet channel can be regulated through the gas pressure regulating chamber when compressed by the piston, the higher the air inlet pressure detected by the pressure sensor is, the larger the distance of the stepping motor driving the variable pressure plunger upwards pulling out is controlled by the controller, the volume of the combustion chamber is increased after the piston reaches the top dead center, the compression ratio of the gas is reduced, the variable pressure plunger is pushed into the variable pressure rod after the air inlet pressure detected by the pressure sensor is reduced, the volume of the combustion chamber is reduced, the compression ratio of the gas is increased, therefore, the gas compression ratio in the cylinder can be balanced or controllable through the space generated by the gas pressure regulating chamber, and the danger that the turbocharging system, the system changes the compression ratio of gas through the adjustment of the variable pressure plunger in the variable pressure bar, and does not cause change and power consumption to the traditional motion mechanism.

Drawings

The invention is explained in further detail below with reference to the drawings.

Figure 1 is a schematic diagram of the overall structure of the system,

figure 2 is a mechanical block diagram of the system,

figure 3 is a schematic side view of the system,

figure 4 is a diagram of the variable pressure ram ascent operation of the system,

fig. 5 is a control circuit diagram of the system.

Detailed Description

As can be seen from figure 1, the system is formed by installing a pressure regulating device at the top end of a cylinder cover, the system drives a transmission screw rod through a stepping motor to enable a variable pressure plunger piston to move up and down in a variable pressure cylinder, the compression volume and the compression ratio of a cylinder are regulated through a gas pressure regulating chamber generated at the lower end of the variable pressure plunger piston, the cylinder cover (1) is provided with an air inlet (2) and an air outlet (3), the air inlet and the air outlet are respectively provided with an air inlet valve rod (4) and an air outlet valve rod (5), a valve is driven to move by a valve driving device (6), the middle and outer sides of the air inlet and the air outlet on the cylinder cover are provided with a variable pressure lever (7), the variable pressure cylinder is of a cylindrical structure, an inner cylinder is communicated with a valve chamber at the lower end of the cylinder cover, the variable pressure lever (7), the outer diameter of the variable pressure plunger is the same as the inner diameter of the variable pressure cylinder, dynamic sealing is realized by the variable pressure plunger and the variable pressure cylinder, a sealing ring (9) is arranged at the lower end of the variable pressure plunger (8) and used for enhancing the sealing performance between the variable pressure cylinder and the variable pressure plunger, a thread groove (10) is arranged at the center of the variable pressure plunger, the upper end opening and the lower end of the thread groove are sealed, threads are arranged on the periphery of the thread groove, threads are arranged on a transmission screw (11), the threads on the periphery of the thread groove (10) are matched with the threads on the transmission screw (11), the lower end of the transmission screw is screwed into the thread groove on the variable pressure plunger by the threads, when the transmission screw (11) rotates left and right, the variable pressure plunger (8) can move up and down in the variable pressure cylinder (7) under the push-pull acting force of the threads on the transmission screw (11), a, the upper end of the limiting wheel is provided with a sealing ring (14), the transmission screw rod can only rotate but cannot move up and down under the limiting action of the limiting wheel, a coupler (16) is arranged on an output shaft at the upper end of the synchronous chain wheel and an output shaft of the stepping motor (15), the stepping motor (15) drives the transmission screw rod (11) to rotate forward and backward when the equipment works, so that a variable pressure plunger (8) is driven to move up and down in a variable pressure cylinder (7), a gas pressure sensor (17) is arranged on an air inlet channel of the engine and used for detecting the gas pressure in the air inlet channel in real time and inputting a detected signal into a controller (18), the controller is arranged on a machine body of the engine and is connected with the gas pressure sensor (17), the stepping motor (15) and a storage battery of an automobile by leads, the controller is a control center of the system, and is internally provided with a signal processing, the signal processing unit is used for processing signals detected by the gas pressure sensor (17) to form driving signals of the stepping motor driver, the output signals are amplified by the signal amplifying unit and then input into the stepping motor driver, a forward and reverse rotation driving power supply output by the stepping motor driver is connected with the stepping motor through a lead, forward and reverse rotation of the stepping motor is controlled to run, and the working procedure of the controller (18) is as follows; the gas pressure sensor (17) detects the inlet pressure of the gas inlet channel in real time, the controller does not act when the pressure is a normal pressure value, the signal processing unit outputs a forward rotation signal to the stepping motor driver when the pressure exceeds a set value, the stepping motor driver processes the signal and drives the stepping motor to rotate in the forward direction, the variable pressure plunger (8) can be lifted from the variable pressure cylinder (7) to the upper end through the transmission screw (11), when the gas pressure sensor (17) detects the pressure drop of the gas inlet channel or the set value is recovered, the signal processing unit outputs a reverse rotation signal to the stepping motor driver, the stepping motor driver processes the signal and drives the stepping motor to rotate in the reverse direction, the variable pressure plunger (8) is pushed downwards into the variable pressure cylinder (7) under the linkage action of the transmission screw, and the controller controls the number of forward and reverse rotation of the stepping motor by the signal input by the signal processing unit, when the larger the air inlet pressure is detected, the larger the signal value input by the signal processing unit into the stepping motor driver is, the more the forward rotation number signal input by the stepping motor driver into the stepping motor is, so as to drive the variable pressure plunger to lift to the corresponding position, when the air inlet pressure is reduced, the stepping motor driver inputs the reverse power supply signal into the stepping motor, at the moment, the stepping motor drives the variable pressure plunger to push into the variable pressure cylinder, so as to control the high and low position of the variable pressure plunger in the variable pressure cylinder through the detected air inlet pressure, a display screen and an adjusting button are arranged outside the controller, the detection value of the air pressure sensor and the driving value of the stepping motor can be adjusted through the adjusting button, when the crankshaft drives the connecting rod (19) to enable the piston (20) to lift to the top dead center in the engine operation, the air in the air cylinder (21) is compressed, when the air pressure in the air inlet channel is at the normal pressure value, when the gas pressure in the gas channel is increased after the turbocharging system works, the volume of the air entering the cylinder is increased, the controller drives the stepping motor (15) to lift the pressure-changing plunger (8) upwards through the transmission screw (11), the bottom end of the pressure-changing cylinder (7) can form a gas pressure-regulating chamber after the pressure-changing plunger moves upwards, so that the compression volume at the top of the cylinder is increased, the compression volume of the cylinder can be changed by the up-and-down movement of the pressure-changing plunger in the pressure-changing cylinder, and the compression ratio in the cylinder can be always in the optimal state when the engine operates at normal pressure and the turbocharging system is intervened.

As can be seen from figure 2, the top end of the cylinder cover (1) is provided with an air inlet (2), an air outlet (3), an oil nozzle hole (22), a spark plug hole (23) and a pressure changing bar (7), the pressure changing cylinder (7) is positioned on one side of the air inlet and the air outlet and forms an integral structure with the cylinder cover, the pressure changing cylinder is a hollow cylinder, the inner diameter of the pressure changing cylinder is smooth, the inner diameter of the pressure changing cylinder is communicated with a valve chamber at the lower end of the cylinder cover (1), a pressure changing plunger (8) is a cylinder, the outer diameter of the pressure changing plunger is the same as the inner diameter of the pressure changing cylinder, the pressure changing plunger and the pressure changing cylinder realize dynamic sealing, the lower end of the pressure changing plunger is provided with a sealing ring (9) for enhancing the sealing performance of the pressure changing cylinder and the pressure changing plunger, the pressure changing plunger can slide up and down in the pressure changing cylinder, the lower end of the pressure changing cylinder, the center of the pressure-changing plunger (8) is provided with a thread groove (10), the threads on the transmission screw (11) are matched with the threads of the thread groove, the lower end of the transmission screw is screwed into the thread groove on the pressure-changing plunger by the threads, when the transmission screw rotates left and right, the pressure-changing plunger (8) can ascend or descend in the pressure-changing cylinder (7) by the thread groove, the top end of the outer side of the pressure-changing cylinder (7) is provided with a limit pin (25), the top end of the outer side of the pressure-changing plunger (8) is provided with a limit card (26), the limit pin and the limit card are contacted with each other, so that the pressure-changing plunger can slide up and down in the pressure-changing cylinder without rotating left and right, the transmission screw (11) is provided with a synchronous sprocket (12), when the system is applied to a multi-cylinder integrated engine, the synchronous sprockets on a, the top end of the synchronous chain wheel is provided with a limiting wheel (13), the limiting wheel can enable a transmission screw rod (11) to rotate left and right and cannot move up and down after being matched with a limiting groove (28) in a shell of a cylinder cover, a sealing ring (14) is arranged at the upper end of the limiting groove, a stepping motor (15) is installed on the shell of the cylinder cover through an installation support, an output shaft of the stepping motor is connected with the top end of the transmission screw rod through a coupler (16), and when the stepping motor rotates, the transmission screw rod (11) can be driven to rotate so that a variable pressure plunger (8) can move up and down in a variable pressure cylinder (7.

As can be seen from fig. 3, the upper end of the cylinder cover (1) is provided with a spark plug (29), an exhaust port (3) and a variable pressure cylinder (7), the variable pressure cylinder and the horizontal plane of the cylinder cover are arranged at an angle of 50-70 degrees, the upper end of the variable pressure cylinder (7) is provided with a variable pressure plunger (8) and a transmission screw (11), and a stepping motor (15) is arranged on the shell of the cylinder cover and used for driving the transmission screw to rotate.

As can be seen from the figure 4, when the variable pressure plunger (8) is lifted upwards from the variable pressure cylinder (7) through the transmission screw rod (11) after the stepping motor (15) rotates, the lower end of the variable pressure cylinder can form a gas pressure regulating chamber (27), the lower end of the gas pressure regulating chamber is connected with the compression space of the cylinder, the compression volume of the cylinder can be changed by adjusting the ascending and descending height of the variable pressure plunger, and the compression ratio of gas in the cylinder after the piston reaches the top dead center is adjusted.

It can be seen from fig. 5 that the controller (18) is a circuit control center of the system, an input end (30) of the controller is connected with a storage battery of the vehicle by a lead for obtaining a working power supply, a signal acquisition end is connected with the gas pressure sensor (17) by a lead for acquiring the gas pressure of an engine gas inlet, an output end is connected with the stepping motor (15) by a lead for controlling the lifting action of the variable pressure plunger, the controller is provided with a display screen (31) and an adjusting button (32), the display screen is used for displaying various data, and the adjusting button is used for adjusting a detection value of the gas pressure sensor and a driving value of the stepping motor.

When the system works, the gas pressure in an air inlet passage of an engine is detected in real time by a gas pressure sensor (17), when the gas pressure in the air inlet passage is at normal pressure (natural air suction), a controller (18) does not act, a pressure-changing plunger (8) is at the lowest position of a pressure-changing cylinder (7) at the moment, the engine can complete the working stroke of air suction, compression, work and exhaust, when the rotating speed of the engine is increased and the pressure of the air inlet passage is increased (turbocharging intervention), the gas pressure sensor (17) inputs the detected data into the controller (18), the controller processes the pressure value of the gas and outputs a forward rotation power supply signal to a stepping motor (15), when the stepping motor rotates clockwise, a transmission screw (11) is driven by a coupler (16) to lift the pressure-changing plunger (8) upwards from the pressure-changing cylinder (7), and the lower end of the pressure-changing plunger can form a gas pressure adjusting chamber (27), when the piston reaches the top dead center, the compression volume of the cylinder can be increased through the gas pressure regulating chamber, the high-pressure air with large volume sucked in the cylinder still keeps the set compression ratio after being regulated through the gas pressure regulating chamber, the controller outputs a counterclockwise reverse power supply to the stepping motor (15) after the gas pressure sensor detects that the pressure of the gas inlet channel is reduced, the stepping motor pushes the variable-pressure plunger (8) to the low position of the variable-pressure cylinder (7) through the transmission screw rod after reversing, the compression volume in the cylinder is reduced at the moment, the volume of the gas sucked in the gas inlet channel is reduced after the gas pressure is reduced, the compression ratio balance is still kept through the regulation of the gas pressure regulating chamber, so that the set gas compression ratio is still kept in the cylinder when the engine is in a natural suction state and a turbo-charging state, the device operates independently when the system is applied to a single-cylinder engine, and synchronous chain wheels (12) of a, one stepping motor can drive a plurality of systems to synchronously operate.

The system utilizes the variable pressure cylinder added at the top end of the cylinder cover to adjust the compression volume and the gas compression ratio inside the cylinder, does not change the prime power system of the engine, can freely change the compression volume and the compression ratio inside the cylinder through the variable pressure plunger and the variable pressure cylinder when the engine runs, does not generate extra power consumption and abnormal vibration source to the power system of the engine, is simpler and more practical compared with the traditional mode of changing the compression ratio by changing a mechanical motion mechanism, effectively improves the working efficiency and the safety performance of the engine, has simple structure, comprises variable pressure plunger, transmission screw and stepping motor as motion parts, has higher mechanical strength of the parts, has more economic value compared with the traditional structure, is controlled by an independent control system, does not change the circuit structure of the engine, can be installed by replacing the cylinder cover of the original engine during later installation, therefore, the method has stronger compatibility.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A plunger type compression ratio variable control system of an engine comprises a transformation device and a control device which are arranged on a cylinder cover, wherein the transformation device comprises a transformation cylinder (7), a transformation plunger (8), a transmission screw (11) and a stepping motor (15), and is characterized in that the transformation cylinder is provided with a plunger piston; the top end of the cylinder cover (1) is provided with a pressure changing lever (7), the pressure changing cylinder (7) is positioned on one side of an air inlet and an air outlet, the pressure changing cylinder is a hollow cylinder, the inner diameter of the pressure changing cylinder is smooth, the inner diameter of the pressure changing cylinder is communicated with an air valve chamber at the lower end of the cylinder cover (1), the pressure changing plunger (8) is a cylinder, the outer diameter of the pressure changing cylinder is the same as the inner diameter of the pressure changing cylinder, the pressure changing cylinder and the pressure changing cylinder realize dynamic sealing, the lower end of the pressure changing plunger (8) is provided with a sealing ring (9), the pressure changing plunger can slide up and down in the pressure changing cylinder, the center of the pressure changing plunger (8) is provided with a thread groove (10), a thread on a transmission screw (11) is matched with the thread of the thread groove, the lower end of the transmission screw is screwed into the thread groove on, a synchronous chain wheel (12) is arranged on the transmission screw rod (11), a limiting wheel (13) is arranged at the top end of the synchronous chain wheel, the transmission screw rod (11) can rotate left and right and cannot move up and down after the limiting wheel is matched with a limiting groove (28) in a shell of the cylinder cover, a sealing ring (14) is arranged at the upper end of the limiting groove, a stepping motor (15) is installed on the shell of the cylinder cover through an installation support, and an output shaft of the stepping motor is connected with the top end of the transmission screw rod through a coupler (16).

2. The plunger compression ratio variable control system of an engine according to claim 1, characterized in that; the control device is composed of a gas pressure sensor (17) and a controller (18), wherein the gas pressure sensor (17) is installed on a gas inlet channel of the engine and used for detecting gas pressure in the gas inlet channel in real time, the controller is installed on a machine body of the engine and connected with the gas pressure sensor (17), a stepping motor (15) and a storage battery of the automobile through leads, and a display screen and an adjusting button are arranged outside the controller.

3. The plunger compression ratio variable control system of an engine according to claim 1, characterized in that; the working mode of the pressure changing device is that a stepping motor drives a transmission screw to enable a pressure changing plunger to move up and down in a pressure changing cylinder, and a gas pressure regulating chamber generated at the lower end of the pressure changing plunger is used for regulating the compression volume and the compression ratio of a cylinder.

4. The plunger compression ratio variable control system of an engine according to claim 1, characterized in that; the variable pressure cylinder and the horizontal plane of the cylinder cover are arranged at an angle of 50-70 degrees.

5. The plunger compression ratio variable control system of an engine according to claim 1, characterized in that; when the system is applied to a multi-cylinder engine, synchronous chain wheels on a plurality of devices are connected by using synchronous chains, and a stepping motor drives variable-pressure plungers on a plurality of cylinder heads to synchronously move.

6. The plunger compression ratio variable control system of an engine according to claim 1, characterized in that; the variable pressure cylinder (7) and the cylinder cover (1) are of an integral structure.

7. The plunger compression ratio variable control system of an engine according to claim 2, characterized in that; the controller (18) is a circuit control center of the system, the input end (30) of the controller is connected with a storage battery of the vehicle through a lead, the signal acquisition end is connected with the gas pressure sensor (17) through a lead, the output end is connected with the stepping motor (15) through a lead, a signal processing unit, a signal amplification unit and a stepping motor driver are arranged inside the controller, and a display screen (31) and an adjusting button (32) are arranged outside the controller.

8. The plunger compression ratio variable control system of an engine according to claim 2, characterized in that; the working procedure of the controller (18) is as follows;

1. the gas pressure sensor (17) detects the inlet pressure of the air inlet channel in real time, the controller does not act when the pressure is a normal pressure value,

2. when the gas pressure in the gas inlet passage exceeds a set value, the signal processing unit outputs a forward rotation signal to the stepping motor driver, the stepping motor driver processes the signal and drives the stepping motor to rotate in the forward direction, the variable pressure plunger (8) is lifted from the variable pressure cylinder (7) to the upper end through the transmission screw rod (11),

3 when the gas pressure sensor (17) detects the pressure drop of the gas inlet or recovers the set value, the signal processing unit outputs a reverse signal to the stepping motor driver, the stepping motor driver processes the signal and then drives the stepping motor to rotate in the opposite direction, and the transmission screw pushes the variable pressure plunger (8) downwards into the variable pressure cylinder (7).

9. The plunger compression ratio variable control system of an engine according to claim 2, characterized in that; the controller works in such a way that the signal processing unit inputs a signal of the stepping motor driver to control the number of forward and reverse rotation turns of the stepping motor, when the higher the intake pressure is detected, the larger the signal value of the signal processing unit input to the stepping motor driver is, the more forward rotation turn signals are input to the stepping motor by the stepping motor driver, and when the intake pressure is reduced, the more reverse power supply signals are input to the stepping motor by the stepping motor driver.

10. The plunger compression ratio variable control system of an engine according to claim 2, characterized in that; the outside of controller is equipped with display screen and adjustment button, can adjust gas pressure sensor's the detection numerical value and step motor's drive numerical value through adjustment button.