CN111911282A - Electric control valve system for two-stage turbocharger of engine and control method - Google Patents

Abstract

The invention discloses an electric control valve system and a control method for an engine two-stage turbocharger. The end of an output shaft is embedded with an external spur gear, and the left end of a deceleration and torque-increasing mechanism is provided with an internal spur coaxial with the external spur gear. Cylindrical gear, between the external spur gear and the internal spur gear, there is a planetary gear that meshes with both the external spur gear and the internal spur gear, which plays the role of power transmission and high speed deceleration and torque increase of the stepping motor. effect. The deceleration and torque-increasing mechanism and the motion conversion mechanism of the present invention convert the step-by-step rotary motion on the stepping motor into the linear motion of the screw ejector rod, and at the same time play the role of deceleration and torque-increasing, and finally act on the valve plate by the screw ejector rod, Push the valve plate to rotate, the electric control valve can realize adjustable opening and closing, the adjustment opening degree is more than 60°, occupying a small space, not easy to interfere, easy to assemble and disassemble, flexibly adjust the rotation angle of the stepping motor, and realize deceleration and torque increase through the transmission mechanism , motion conversion, so as to adjust the opening of the corresponding valve.

Description

Electronic control valve system and control method for engine secondary turbocharger

technical field

The invention relates to the technical field of turbocharging of internal combustion engines, in particular to an electronically controlled valve system and a control method for a secondary turbocharger of an engine.

Background technique

There are many ways to boost the engine. At present, the research of supercharging technology by researchers still takes turbocharging as the main direction, but there are many other supercharging methods with diversified characteristics. Due to the inherent shortcomings of traditional turbochargers, it is difficult to take into account the boost ratio required by the high and low speed conditions of the engine within the flow range of the turbocharger. The pressure system came into being.

The specific working principle of the two-stage adjustable supercharging system is as follows: when the diesel engine is at a low speed, the exhaust gas flow first passes through the high-pressure stage turbine, the electronically controlled valve is closed at this time, and then passes through the low-pressure stage turbine; when the diesel engine rotates at a high speed, The electronically controlled valve of the turbocharger is opened, and part of the exhaust gas flow directly enters the low-pressure turbo expansion through the bypass branch, and the two-stage supercharging effect can be achieved. The engine has different requirements for boost pressure under different working conditions, and the opening of the bypass valve can be controlled to achieve different boost ratios of the high and low pressure turbochargers. On the other hand, the bypass valve can play the role of overload protection, because the high-pressure stage turbocharger is closer to the exhaust gas flow, the exhaust energy is large, and the supercharger is damaged. When the exhaust gas flow energy is too high, adjust the turbine bypass. The opening of the through valve can protect the high pressure turbocharger from overspeeding. The low-pressure turbocharger operates smoothly and maximizes the use of exhaust energy.

Obviously, the use of a suitable two-stage supercharging system control method can improve the torque and maximum power of the compression ignition engine, reduce fuel consumption, and improve power performance under low-speed conditions. If the two-stage supercharger system is to be used in vehicles, more in-depth experimental research must be carried out for variable working conditions. At present, the control valve of the turbocharger is a pneumatic valve. The pneumatic valve is controlled by an external air source in the laboratory. Manually control the ball valve on the gas circuit to change the pressure of the gas circuit to realize the action of the valve actuator and finally realize the opening and closing of the valve. However, the pneumatic valve is not suitable for the study of two-stage pressurization under variable working conditions. The pneumatic valve has the following defects: the pressure of the air circuit is controlled by the ball valve, the opening angle of the ball valve is difficult to accurately control, and the pressure of the external air source is due to the intermittent operation of the air pump. Sexual work causes the pressure fluctuation of the surge tank, which further increases the difficulty of control; due to the need to control the valve opening angle through the ball valve in real time during the high-speed operation of the engine, the response time of manual control is too slow. Therefore, the control of the electronically controlled valve of the turbocharger is bound to be a difficult point in future research.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problems, the purpose of the present invention is to provide an electronically controlled valve system and a control method for an engine two-stage turbocharger, wherein the deceleration and torque-increasing mechanism and the motion conversion mechanism convert the stepping rotary motion on the stepping motor into a screw top. The linear movement of the rod part also plays the role of deceleration and torque increase. Finally, the screw ejector rod acts on the valve plate to push the valve plate to rotate. The electric control valve can realize adjustable opening and closing, and the adjustment opening is more than 60°. Simple, small size, small footprint, not easy to interfere, easy to assemble, disassemble and arrange.

In order to realize the above-mentioned technical purpose and achieve the above-mentioned technical effect, the present invention is realized through the following technical solutions:

An electronically controlled valve system for an engine two-stage turbocharger includes a stepper motor fixed on a support plate, a deceleration and torque increase mechanism, a motion conversion mechanism and a screw connected to the end of the stepper motor in turn from left to right. The ejector rod; the deceleration and torque increase mechanism is a spur gear transmission part, the motion conversion mechanism is a screw drive pair, the stepping motor includes an output shaft at the end, and the end of the output shaft is embedded in an external spur gear gear, the left end of the deceleration and torque-increasing mechanism is provided with an inner spur gear coaxial with the outer spur gear, and between the outer spur gear and the inner spur gear The outer spur gear and the inner spur gear are meshed with the planetary gear, which plays the role of power transmission, deceleration and torque increase of the stepping motor at high speed.

Further, a sealing cover is provided outside the inner spur gear.

Further, it also includes a drive system, which includes a host computer, a 51 single-chip microcomputer, a stepper motor controller, a 24v regulated power supply, a trapezoidal gear rod, a universal joint transmission mechanism, and an electric control valve.

Further, the output shaft is a spline shaft.

Further, the side of the support plate is provided with a stepper motor connection hole, the bottom is provided with a support hole, a stepper motor mounting seat is provided at the connection between the stepper motor and the support plate, and the stepper motor passes through the The stepper motor mounting seat and the stepper motor connection hole are fixed on the support plate to ensure the stability of the entire system.

Further, the diameter of the stepper motor connection hole is 6mm, and the diameter of the support hole is 12mm.

Further, the deceleration and torque-increasing mechanism is integrally cast with the motion conversion mechanism.

Further, the stepping motor model is 57HS22-A.

Further, the planetary gear is fixed on the planet carrier, the planet carrier is fixedly connected with the engine, and the motion conversion mechanism is a ball screw.

A control method for an electronically controlled valve system for a secondary turbocharger of an engine, comprising the following steps: a valve opening requirement is given by the host computer, a control signal is obtained through calculation, and is transmitted to the 51 single-chip microcomputer through a serial port, and the 51 The single-chip microcomputer calculates the pulse signal and discovery signal that needs to be transmitted to the stepping motor controller through the program and then transmits it to the stepping motor controller. The stepping motor controller passes the internal circuit and program to the 51 The 5v signal given by the single-chip microcomputer is converted into a pulse signal output to the stepper motor to control the rotation angle of the stepper motor, and the circular motion of the stepper motor is rotated through the deceleration and torque increase mechanism and the motion conversion mechanism. The linear motion is transmitted to the screw ejector rod. The screw ejector rod acts as an output mechanism and is connected to the valve plate on the engine exhaust system. The screw ejector rod drives the valve to open and close to change the opening degree of the valve plate.

The beneficial effects of the present invention are:

The deceleration and torque-increasing mechanism and the motion conversion mechanism of the present invention convert the step-by-step rotary motion on the stepping motor into the linear motion of the screw ejector rod, and at the same time play the role of deceleration and torque-increasing, and finally act on the valve plate by the screw ejector rod, Push the valve plate to rotate, the electric control valve can realize adjustable opening and closing, and the adjustment opening degree is above 60°; the sealing cover can play a certain sealing protection function to prevent the entry of sundries, so that the system can be fully lubricated; the output shaft is a flower The key shaft can greatly reduce the vibration of the motor output shaft, and at the same time realize the power transmission within a small angle variation range, to prevent control accuracy problems caused by improper installation angle of the support plate or loosening of the fixing nut; the drive system is output through the computer Control signal, precise opening angle control, fast execution, short response time, real-time control, stepper motor with self-locking function, no opening angle fluctuation caused by fluctuation of intake pressure, simple mechanism, no need for external air source, etc. , the power supply can be directly borrowed from the vehicle battery; the structure is simple, the size is small, the space is small, the interference is not easy, and it is easy to assemble, disassemble and arrange.

The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly, and implement it according to the content of the description, the preferred embodiments of the present invention are described in detail below with the accompanying drawings. Specific embodiments of the present invention are given in detail by the following examples and the accompanying drawings.

Description of drawings

Fig. 1 is the structural representation of the present invention;

Fig. 2 is the front view of Fig. 1;

Fig. 3 is the top view of Fig. 1;

Figure 4 is a schematic diagram of the meshing of the outer spur gear and the inner spur gear with the planetary gear;

FIG. 5 is a program control logic diagram of the present invention.

Description of the labels in the figure:

1. Stepper motor, 2. Support plate, 3. Screw ejector rod, 4. Movement conversion mechanism, 5. Deceleration and torque increasing mechanism, 6. Sealing cover, 7. External spur gear, 8. Internal spur gear , 9, planetary gear.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

Referring to Figures 1 to 4, an electronically controlled valve system for an engine secondary turbocharger includes a stepper motor 1 fixed on a support plate 2, and is connected to the end of the stepper motor 1 in turn from left to right. The deceleration and torque-increasing mechanism 5, the motion conversion mechanism 4 and the screw jack 3; the deceleration and torque-increasing mechanism 5 is a spur gear transmission, the motion conversion mechanism 4 is a screw drive pair, and the stepping motor 1 includes an output shaft at the end, The output shaft is a spline shaft, the end of the output shaft is embedded with an external spur gear 7, the left end of the deceleration and torque increasing mechanism 5 is provided with an internal spur gear 8 coaxial with the external spur gear 7, and the external spur gear 7 is connected to the A planetary gear 9 meshing with both the outer spur gear 7 and the inner spur gear 8 is arranged between the inner spur gear 8, which plays the role of power transmission and deceleration and torque increase of the stepping motor 1 at high speed. The wheel 9 is fixed on the planet carrier, the planet carrier is fixedly connected with the engine, and the model of the stepper motor 1 is 57HS22-A.

Further, the inner spur gear 8 is provided with a sealing cover 6 outside, which can play a certain sealing protection function, prevent the entry of sundries, and make the system fully lubricated.

Further, it also includes a drive system, which includes a host computer, a 51 single-chip microcomputer, a stepper motor controller, a 24v regulated power supply, a trapezoidal gear rod, a universal joint transmission mechanism, and an electric control valve.

Further, the side of the support plate 2 is provided with a stepper motor connection hole, the bottom is provided with a support hole, the stepper motor 1 and the support plate 2 are connected with a stepper motor mount, and the stepper motor 1 passes through the stepper motor mount. The connecting hole with the stepping motor is fixed on the support plate 2 to ensure the stability of the whole system. The diameter of the connecting hole of the stepping motor is 6mm, and the diameter of the support hole is 12mm.

Further, the deceleration and torque-increasing mechanism 5 and the motion conversion mechanism 4 are integrally cast.

The invention includes three parts: the selection of the motor, the selection of the deceleration and torque-increasing mechanism, and the selection of the motion conversion mechanism.

Because the pulse signal of the stepping motor can be directly converted into the rotation of the stepping motor, the control process can be completed only by the single-chip system, the overall structure is simple, the cost is low, and no A/D converter is required; the deceleration and torque increasing mechanism 5 is a straight tooth Cylindrical gear transmission parts, the gear transmission power range is large, the structure is compact, the transmission speed range is wide, the transmission is stable, accurate and reliable, the instantaneous transmission ratio is constant, and the transmission ratio can be larger, and the transmission ratio can reach 7~8. In multi-stage transmission, it still has high efficiency and reliability, and the structure is simple and easy to design and manufacture; the motion conversion mechanism 4 is a screw drive pair, including a sliding screw and a ball screw. The sliding screw has a simple structure and is easy to process. Friction transmission leads to large frictional resistance, easy to wear and glue during the working process, and the life is shorter than that of the ball screw. The ball screw transmits movement through rolling friction, with a small friction coefficient and high efficiency. Long, the disadvantage is that its self-locking ability is poor, and the ball screw is preferred from the perspective of productization.

A control method for an electronically controlled valve system for a secondary turbocharger of an engine, comprising the following steps: a host computer gives a valve opening requirement, obtains a control signal through calculation, transmits it to a 51 single-chip microcomputer through a serial port, and the 51 single-chip microcomputer calculates through a program The pulse signal and discovery signal that need to be transmitted to the stepper motor controller are then passed to the stepper motor controller. The stepper motor controller converts the 5v signal given by the 51 single-chip microcomputer into the output to the stepper motor 1 through the internal circuit and program. The pulse signal controls the rotation angle of the stepping motor 1, and through the deceleration and torque increasing mechanism 5 and the motion conversion mechanism 4, the circular motion of the stepping motor 1 is turned into a linear motion and transmitted to the screw ejector rod 3, and the screw ejector rod 3 is used as an output mechanism. It is connected with the valve plate on the engine exhaust system, and drives the valve to open and close through the screw ejector rod 3 to change the opening degree of the valve plate.

Referring to Fig. 5, the program control logic of the present invention is as follows:

Turn on the communication function, wait for the command from the host computer, call the main function from the program, set the communication working mode of the single-chip microcomputer, judge whether the system is in an idle state, perform the next control in the idle state, read the target value, the flag position is 0, and the reception interrupt is closed. , to judge whether the input parameters have changed, if there is a change, go to the next step, compare the input angle a with the last input angle b to get the difference c, and judge whether the difference is positive or negative. Control, and then carry out the pulse calculation program. If it is a positive value, directly prepare for pulse calculation and transmission, convert the obtained difference c to the required number of pulses d, and send it to the stepper motor controller for execution.

The electric control valve of the present invention can realize adjustable opening and closing, and the adjustment opening degree is above 60°. At the same time, it plays the role of deceleration and torque increase, and then compensates for the deviation of the angle of the two axes through the universal joint transmission mechanism, and finally acts on the valve plate through the screw ejector rod 3 to push the valve plate to rotate. The screw top rod 3 can directly exert force on the outer paddle of the electronically controlled valve plate to push the inner valve plate to rotate, similar to the throttle paddle of an internal combustion engine.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. An electronically controlled valve system for an engine two-stage turbocharger, characterized in that it comprises a stepper motor (1) fixed on a support plate (2), and is sequentially connected to the stepper motor (1) from left to right. 1) The deceleration and torque-increasing mechanism (5), the motion conversion mechanism (4) and the screw jack (3) at the end; the deceleration and torque-increasing mechanism (5) is a spur gear transmission, and the motion conversion mechanism ( 4) It is a screw drive pair, the stepper motor (1) includes an output shaft at the end, the end of the output shaft is embedded in an external spur gear (7), and the left end of the deceleration and torque increasing mechanism (5) is provided with The inner spur gear (8) is coaxial with the outer spur gear (7), and the outer spur gear (7) and the inner spur gear (8) are provided with an internal spur gear (8). A planetary gear (9) in which the outer spur gear (7) and the inner spur gear (8) both mesh. 2 . The electronically controlled valve system for an engine two-stage turbocharger according to claim 1 , wherein a sealing cover ( 6 ) is provided outside the inner spur gear ( 8 ). 3 . 3. The electronically controlled valve system for an engine two-stage turbocharger according to claim 2, further comprising a drive system, the drive system comprising a host computer, a 51 single-chip microcomputer, a stepper motor controller, and a 24v voltage regulator Power supply, trapezoidal rack and universal joint transmission mechanism and electric control valve. 4 . The electronically controlled valve system for an engine two-stage turbocharger according to claim 3 , wherein the output shaft is a spline shaft. 5 . 5 . The electronically controlled valve system for an engine two-stage turbocharger according to claim 4 , wherein the support plate ( 2 ) is provided with a stepper motor connection hole on the side and a support hole on the bottom. 6 . A stepper motor mount is provided at the connection between the stepper motor (1) and the support plate (2), and the stepper motor (1) is fixed to the stepper motor via the stepper motor mount and the stepper motor connection hole. on the support plate (2). 6 . The electronically controlled valve system for an engine two-stage turbocharger according to claim 5 , wherein the diameter of the stepper motor connection hole is 6 mm, and the diameter of the support hole is 12 mm. 7 . 7 . The electronically controlled valve system for an engine two-stage turbocharger according to claim 6 , wherein the deceleration and torque-increasing mechanism ( 5 ) and the motion conversion mechanism ( 4 ) are integrally cast. 8 . 8 . The electronically controlled valve system for an engine two-stage turbocharger according to claim 7 , wherein the stepping motor ( 1 ) has a model of 57HS22-A. 9 . 9 . The electronically controlled valve system for an engine two-stage turbocharger according to claim 8 , wherein the planetary gear ( 9 ) is fixed on the planet carrier, the planet carrier is fixedly connected with the engine, and the moving The conversion mechanism (4) is a ball screw. 10. A control method for an electronically controlled valve system for an engine two-stage turbocharger according to claim 9, characterized in that it comprises the following steps: a valve opening requirement is given by the host computer, and a control signal is obtained by calculation , transmitted to the 51 single-chip microcomputer through the serial port, the 51 single-chip microcomputer calculates the pulse signal and discovery signal that needs to be transmitted to the stepper motor controller through the program, and then transmits it to the stepper motor controller, and the stepper motor The controller converts the 5v signal given by the 51 single-chip microcomputer into a pulse signal output to the stepper motor (1) through the internal circuit and program to control the rotation angle of the stepper motor (1), and increases the rotation angle through the deceleration. The torsion mechanism (5) and the motion conversion mechanism (4) convert the circular motion of the stepping motor (1) into linear motion and transmit it to the screw ejector rod (3), the screw ejector rod (3) As an output mechanism, it is connected with the valve plate on the exhaust system of the engine, and the valve plate is driven to open and close through the screw ejector rod (3) to change the opening degree of the valve plate.

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