Electronic throttle control system and method for suction and pressure conveying vehicle

Abstract

A suction and pressure feeding vehicle electronic throttle control system and method, the suction and pressure feeding vehicle electronic throttle control system, the switch input terminal X1 of the PLC programmable controller is connected to the OUT1 normally open point of the vacuum pump tachometer, the switch input terminal X0 of the PLC programmable controller is connected to the OUT1 normally open point of the gear pump tachometer, the switch output terminals Y0 and Y1 of the PLC programmable controller are respectively connected to the coil ends of the K1 relay and the K2 relay, the speed IN end of the vacuum pump tachometer is connected to the signal output end of the proximity switch 1, +MV and 0V are respectively connected to the normally open contact and normally closed contact of the K1 relay and the K2 relay, and the common end of the contact of the K1 relay and the K2 relay is connected to the root terminal of the DC motor in the motor potentiometer. The control system of the present invention determines the output stop signal according to the relationship between the real-time speed of the engine and the upper limit set by the tachometer, so as to simplify the control system, reduce costs, and facilitate maintenance.

Description

Technical Field

[0001] The invention relates to the field of suction and pressure conveying vehicles, and in particular to an electronic throttle control system and method for a suction and pressure conveying vehicle. Background Art

[0002] The suction and pressure conveyor is a special vehicle for transporting steelmaking dust in steel mills. The vacuum pump provides a negative pressure gas source for the suction and pressure conveyor when sucking (loading). The gear pump provides power for the hydraulic system of the suction and pressure conveyor, which is used to lift the tank and lift the legs. The power of the vacuum pump and gear pump is provided by the vehicle's own engine. The engine speed is controlled by the electronic throttle connected to the ECU module. This electronic throttle is divided into two types: inside the vehicle and outside the vehicle. Ordinary special vehicles generally have only one power take-off output terminal, while the suction and pressure conveyor has two power take-off output terminals due to work needs. The operator selects the corresponding power take-off by pressing different switches in the cab. The outside electronic throttle is an electronic throttle controller of the ECU module that is controlled by the operator outside the vehicle by rotating the potentiometer. The voltage output by the center tap of the potentiometer changes, thereby controlling the engine speed. The higher the voltage output by the potentiometer, the larger the engine throttle and the higher the engine speed.

[0003] When driving a vacuum pump or a gear pump, the engine speed needs to be adjusted to different rated working speeds to achieve optimal working efficiency. The common manual throttle adjustment is that the operator rotates the electronic throttle knob, observes the electronic tachometer, and stops turning the knob when the speed reaches the requirement; in a control system with automatic throttle adjustment, when the engine speed is adjusted in manual mode, the potentiometer is rotated clockwise, and the voltage output by the center tap of the potentiometer is loaded into the analog voltage input module of the on-board PLC control system, and then the analog voltage output module outputs the changing voltage signal to the electronic throttle controller of the ECU module, observes the tachometer, and stops turning the knob when the speed reaches the requirement, thereby realizing manual engine speed adjustment; in automatic throttle adjustment, when the program runs to the throttle adjustment step, the analog voltage output module outputs the set voltage to the electronic throttle controller of the ECU module according to the agreed speed, thereby realizing automatic engine speed adjustment.

[0004] The current suction and pressure conveyor control system design is based on Siemens S7-200 SMART PLC (such as Figure 1), Siemens S7-200 SMART PLC signal board is designed with expandable communication ports, digital channels, and analog channels. Its CPU module body is equipped with an Ethernet interface as standard, which integrates powerful Ethernet communication functions. The touch screen and computer can communicate through the Ethernet interface, and networking is easy. When in use: use the PLC analog input module to collect the output voltage of the manual throttle adjustment knob, and then use the PLC analog output module to output the analog voltage to realize the manual throttle adjustment function; in automatic control, the PLC outputs the set analog voltage through the analog output module to realize the control of the engine throttle. The real-time engine speed signal is collected by the speed sensor. The pulse signal is input to the PLC high-speed switch interface. After calculation by the PLC, the speed value is displayed on the touch screen A. All control processes and states are concentrated on a touch screen A (the effective length and width of the display screen is 220x150mm). B is the control twist, and the control system is more complex. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and to provide an electronic throttle control system and method for a suction and pressure conveying vehicle, which is a simplified control system designed based on a domestic PLC with only switch input and output without using a PLC analog module.

[0006] The technical solution of the present invention is: an electronic throttle control system for a suction and pressure feeding vehicle, characterized in that: it includes a PLC programmable controller, a vacuum pump tachometer, a gear pump tachometer, a motor potentiometer, a proximity switch 1, a K1 relay, a K2 relay, a vacuum pump speed sensor, an electronic throttle controller, a gear pump speed sensor, and a proximity switch 2. The PLC programmable controller has only switch input / output terminals, the switch input terminal X1 of the PLC programmable controller is connected to the OUT1 normally open point of the vacuum pump tachometer, the switch input terminal X0 of the PLC programmable controller is connected to the OUT1 normally open point of the gear pump tachometer, and the switch output terminals Y0 and Y1 of the PLC programmable controller are respectively connected to the coil terminals of the K1 relay and the K2 relay. Connect, the speed IN end of the gear pump tachometer is connected to the signal output end of the proximity switch 1, the speed IN end of the vacuum pump tachometer is connected to the signal output end of the proximity switch 2, +MV and 0V are respectively connected to the normally open contact and normally closed contact of the K1 relay and the K2 relay, the common end of the K1 relay and the K2 relay contact is connected to the root terminal of the DC motor in the motor potentiometer, among the three terminals of the potentiometer in the motor potentiometer, the upper end is connected to +MV, the lower end is connected to 0V and connected to the negative end of the electronic throttle controller, the center tap POT end is connected to the control end of the electronic throttle controller, the vacuum pump speed sensor is fixed on the output shaft of the power take-off 1 of the engine, the gear pump speed sensor is fixed on the output shaft of the power take-off 2 of the engine, M=5.

[0007] The + and - poles of the power supply of the PLC programmable controller, vacuum pump tachometer, gear pump tachometer, proximity switch 1 and proximity switch 2 are connected to the system power supply +24V and GND respectively.

[0008] The distance between the vacuum pump speed sensor and the first sensing surface of the proximity switch is 5-8 mm, and the distance between the gear pump speed sensor and the second sensing surface of the proximity switch is adjusted to 5-8 mm.

[0009] The motor potentiometer is a device that is driven by a DC motor to rotate the potentiometer. When the DC motor rotates forward, the potentiometer rotates clockwise, and the voltage at the middle tap end of the POT gradually increases, and can reach a maximum of 5V. When the DC motor rotates reversely, the potentiometer rotates counterclockwise, and the voltage at the middle tap end of the POT gradually decreases, and can reach a minimum of 0V. The potentiometer rotation handle can be manually rotated and adjusted by hand, and the effect is the same as that of DC motor drive, and these two driving modes do not affect each other. The results of manual mechanical rotation and DC motor rotation of the potentiometer are the same; the vacuum pump tachometer receives a pulse speed signal through the speed IN terminal. When the received speed signal value reaches or exceeds the value set by the electronic tachometer, the OUT1 normally open contact is closed, and it is usually in a disconnected state; the electronic throttle controller is a device that comes with the chassis vehicle. When the voltage at the center tap POT input terminal changes from 0.35V to 3.75V, the engine speed will change from idle to maximum speed, and the higher the voltage, the higher the speed.

[0010] A method for controlling an electronic throttle of a suction and pressure conveying vehicle, wherein a speed control process of a vacuum pump driven by an engine power take-off includes:

[0011] 1) After the system is powered on, the output terminal Y1 of the PLC programmable controller 1 is connected, and the normally open point of the K2 relay connected to it is energized. At this time, the power supply flowing through the motor potentiometer DC motor is negative at the top and positive at the bottom. The DC motor rotates in the opposite direction, driving the potentiometer to rotate counterclockwise until the potentiometer is at 0 point, and stops after T seconds. The output of the motor potentiometer center tap POT terminal is 0V, and the voltage control terminal voltage of the electronic throttle controller is also 0V. At this time, the electronic throttle controls the engine to be in idle state; T=10. According to the technical indicators of the motor potentiometer: the potentiometer rotation speed is 12±3sec / 300° (4.5V DC), that is, the motor is driven by a 4.5V DC voltage. It takes 12 seconds for the DC motor to rotate from zero to 300 degrees, and the motor input voltage is 4-6V DC. It is tested with a 5V voltage and a stopwatch. It actually takes only 9.5 seconds from 0-300°, that is, the full stroke does not exceed 10 seconds. The PLC program is set to run in reverse for 10 seconds after power-on (Y1 has output). After 10 seconds, the program stops the Y1 output, and the power supply on the DC motor is negative on the top and negative on the bottom. The DC motor stops rotating due to no voltage.

[0012] 2) When the automatic throttle control is running, the output terminal Y0 of the PLC programmable controller is connected, and the normally open point of the K1 relay connected to it is energized. At this time, the power flowing through the motor potentiometer DC motor is positive at the top and negative at the bottom. The DC motor rotates forward, and the motor drives the potentiometer to rotate clockwise. The output voltage of the potentiometer POT terminal continues to increase, the engine throttle gradually increases, and the engine speed continues to increase. The proximity switch for monitoring the engine speed provides a pulse signal to the vacuum pump tachometer. When the pulse received by the vacuum pump tachometer reaches the set value, its upper limit OUT1 normally open point closes and provides an in-place signal to the PLC programmable controller switch input X1 terminal. Then the PLC programmable controller switch output terminal Y0 is disconnected, the motor potentiometer stops working, and the engine speed is maintained at the current speed; the speed control process of the gear pump driven by the engine's power take-off 2 is the same as the speed control process of the vacuum pump driven by the engine's power take-off 1.

[0013] A graphical control panel for a suction and pressure conveying vehicle comprises a panel without a touch screen, wherein the upper part of the panel is integrated with three control lines for the loading, unloading and dust removal operations of the suction and pressure conveying vehicle, the three control lines being a loading control line, a unloading control line and a dust removal control line, each of which is provided with a sensor and a valve; each of which is provided with indicator lights of three different colors for distinguishing each of the control lines; the loading control line also has a vacuum pump tachometer, and the unloading control line also has a gear pump tachometer as described above; the vacuum pump tachometer and the gear pump tachometer are placed on the upper part of the panel, and the lower part of the panel is integrated with a potentiometer rotating handle as described above for the motor potentiometer.

[0014] Through research, the inventor discovered that the electronic throttle control system used in the suction and pressure conveying vehicle uses a control system without an automatic control function, which is simple. However, if the throttle knob on the control panel was not reset to zero during the last manual operation but was at a certain rotation angle when the system was just powered on, the engine speed will increase rapidly when switching to the external throttle control. This situation will cause the load driven by the power take-off to malfunction, and the output speed will increase instantaneously, causing the torque to increase instantaneously, which will cause the output drive shaft of the power take-off to break or the meshing gears inside the gear pump to be damaged.

[0015] Based on this, the present invention provides a control method, which uses a domestic PLC with only switch input and output as the control core of the system and is applied to the electronic throttle control system of the suction and pressure conveying vehicle. The control system of the present invention can control the manual or automatic operation of the electronic throttle. The control method includes:

[0016] First, the electronic throttle control voltage is reset to zero to put the engine in an idle state; the relationship between the current engine speed and the upper limit set by the tachometer is obtained; and the output stop signal is determined based on the relationship between the engine speed and the upper limit of the tachometer.

[0017] On the other hand, an embodiment of the present invention provides an electronic throttle control system for a suction and pressure conveying vehicle, which can control the control voltage of the electronic throttle controller. The control system can determine the output stop signal based on the relationship between the real-time engine speed and the upper limit set by the tachometer.

[0018] Based on the above technical solution, the control system and control method provided by the present invention can determine the output stop signal according to the relationship between the real-time engine speed and the upper limit set by the tachometer, so as to simplify the control system, reduce costs and facilitate maintenance.

[0019] In the prior art, once a touch screen fails, for example, the touch screen goes black, the entire system cannot be used, and a new touch screen needs to be purchased for replacement, and it can only be used again after the filling procedure. The maintenance cycle is about one month, which seriously affects the user's use. In view of the above problems in the prior art, if any component in the solution of the present invention fails, only the corresponding component needs to be replaced, and the control system cost and maintenance cost are greatly reduced, and there is no need to change the software, and the maintenance is convenient and fast. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of an existing control panel;

[0021] Figure 2 It is a schematic diagram of the principle of the electronic throttle control system of the suction and pressure conveying vehicle of the present invention;

[0022] Figure 3 It is a schematic diagram of a graphical control panel of the suction and pressure conveying vehicle of the present invention;

[0023] Figure 4 It is a control flow diagram of the electronic throttle control system of the suction and pressure conveying vehicle of the present invention. DETAILED DESCRIPTION

[0024] The invention is further described below in conjunction with the accompanying drawings and specific embodiments. The suction and pressure conveying vehicle generally uses the chassis vehicle's own engine to drive the vacuum pump through the power take-off 1 and the gear pump through the power take-off 2 during operation, and the engine speed needs to be adjusted to their different rated working speeds to achieve the best working efficiency. The engine speed is achieved by adjusting the output voltage of the center tap of the electronic throttle potentiometer outside the vehicle. When the output voltage is high, the throttle becomes larger and the engine speed increases accordingly. When the output voltage is low, the throttle becomes smaller and the engine speed decreases accordingly. Due to the control of the engine ECU, when the electronic throttle output voltage is lower than 0.35V, the engine is switched to idle mode. When the electronic throttle output voltage reaches 3.75V, the engine is controlled to reach the maximum speed.

[0025] The control system of the present invention can control the speed of the engine. This embodiment also provides an electronic throttle control system. Figure 2The control system is composed of a PLC programmable controller 1, a vacuum pump tachometer 2, a gear pump tachometer 3, a motor potentiometer 4, a proximity switch 1 5, a K1 relay 6, a K2 relay 7, a vacuum pump speed sensor 8, an electronic throttle controller 9, a gear pump speed sensor 10, and a proximity switch 2 11.PLC programmable controller 1 is the core of the control system, X0 and X1 terminals are PLC switch input terminals, Y0 and Y1 terminals are PLC switch output terminals; vacuum pump tachometer 2 receives pulse speed signal through speed IN terminal, when the received speed signal value reaches or exceeds the value set by the electronic tachometer, OUT1 normally open contact closes, usually in disconnected state; motor potentiometer 4 is a device driven by DC motor to rotate potentiometer, when DC motor rotates forward, potentiometer rotates clockwise, POT middle tap voltage gradually increases, the highest can reach 5V, when DC motor reverses, potentiometer rotates counterclockwise, POT middle tap voltage gradually decreases, the lowest can reach 0V, the potentiometer rotary handle can also be manually used The effect is the same as that of DC motor drive, and the two driving modes do not affect each other. The results of manual mechanical rotation and DC motor rotation potentiometer are the same. The middle tap POT, 0V end and electronic throttle controller 9 input end are connected, and the engine speed can be controlled by the POT voltage change; proximity switch 1 5 and proximity switch 2 11 are a kind of non-contact inductive proximity switch. When the vacuum pump speed sensor 8 or gear pump speed sensor 10 on the output shaft of the engine power take-off 1 or the engine power take-off 2 rotates, the sensing end face of the proximity switch 5 or the proximity switch 11 is periodically triggered, so that the proximity switch outputs a pulse signal; K1 relay 6 and K2 relay 7 drive the DC motor in the motor potentiometer 4, and its control process When Y0 and Y1 of PLC programmable controller 1 have no output, the normally closed points of K1 and K2 are both connected to the power supply 0V. At this time, the upper and lower ends of the DC motor in the motor potentiometer 4 are both 0V, and the DC motor does not rotate. When Y0 of PLC programmable controller 1 has output, the coil of K1 relay 6 is energized, the normally open contact is closed, and the normally closed contact is disconnected. The upper end of the DC motor in the motor potentiometer 4 is +5V and the lower end is 0V. The DC motor rotates forward, driving the potentiometer to rotate clockwise, and the voltage of the center tap POT terminal will continue to rise. Similarly, when Y1 of PLC programmable controller 1 has output, the coil of K2 relay 7 is energized, the normally open contact is closed, and the normally closed contact is disconnected. The upper end of the DC motor in the motor potentiometer 4 is 0V and the lower end is +5V. When the voltage of the center tap POT terminal is +5V, the DC motor reverses and drives the potentiometer to rotate counterclockwise. The voltage of the center tap POT terminal will continue to decrease and eventually reach 0V. The function of the vacuum pump speed sensor 8 and the gear pump speed sensor 10 is to sense the speed signal of the engine's power take-off 1 or power take-off 2 to the sensing surface of the proximity switch 1 5 and the proximity switch 2 11 in an inductive manner, so that the proximity switch 1 5 and the proximity switch 2 11 can output the corresponding speed pulse signal to the vacuum pump tachometer 2 and the gear pump tachometer 3 signal input speed IN terminal. The electronic throttle controller 9 is a built-in device of the chassis vehicle. When the voltage of its POT input terminal changes from 0.35V to 3.75V, the engine speed will change from idle to maximum speed, and the higher the voltage, the higher the speed.The above description is about the role and function of each component in the control system and the change in the working process, which is an explanation for a better understanding of the present invention. The control system includes a PLC programmable controller 1, a vacuum pump tachometer 2, a gear pump tachometer 3, a motor potentiometer 4, a proximity switch 1 5, a K1 relay 6, a K2 relay 7, a vacuum pump speed sensor 8, an electronic throttle controller 9, a gear pump speed sensor 10, and a proximity switch 2 11. The switch input terminal X1 of the PLC programmable controller 1 is connected to the normally open point OUT1 of the vacuum pump tachometer 2, and X0 is connected to the normally open point OUT1 of the gear pump tachometer 3. The output terminals Y0 and Y1 of the PLC programmable controller 1 are respectively connected to the coil ends of the K1 relay 6 and the K2 relay 7. The speed IN end of the vacuum pump tachometer 2 is connected to the signal output end of the proximity switch 5. +5V and 0V are respectively connected to the normally open contact and normally closed contact of the K1 relay 6 and the K2 relay 7. The contact common end of relay 1 6 and relay K2 7 is connected to two wiring terminals of the DC motor in the motor potentiometer 4. Among the three terminals of the potentiometer in the motor potentiometer 4, the upper end is connected to +5V, the lower end is connected to 0V and connected to the negative end of the electronic throttle controller 9, and the center tap POT end is connected to the control end of the electronic throttle controller 9. The vacuum pump speed sensor 8 is fixed on the output shaft of the power take-off 1, and the spacing between the vacuum pump speed sensor 8 and the sensing surface of the proximity switch 1 5 is adjusted to 5mm. The gear pump speed sensor 10 is fixed on the output shaft of the engine power take-off 2, and the spacing between the gear pump speed sensor 10 and the sensing surface of the proximity switch 2 11 is adjusted to 5mm. The power supply + and - poles of the PLC programmable controller 1, the vacuum pump tachometer 2, the gear pump tachometer 3, the proximity switch 1 5, and the proximity switch 2 11 are respectively connected to the system power supply +24V and GND, so the power supply is a general conventional connection and is not shown in the figure.

[0026] Figure 2 The control system shown is only a specific form of implementing the technical solution of the present invention. It can realize the electronic throttle control of the suction and pressure conveying vehicle, and control different engine speeds under the dual power take-off state. The control system can control the speed of the suction and pressure conveying vehicle engine and is suitable for the technical solution of the present invention. Figure 2It is an embodiment of the present invention, which adopts a graphical operation panel. As an implementation scheme of the technical solution of the present invention, the control system adopts a motor potentiometer of model RD16812MG098 as an engine electronic throttle voltage adjustment actuator, an NPN inductive proximity switch as a sampling device for the engine output speed signal, a high-precision motor tachometer of model SCN-P71 with upper and lower limit outputs as a feedback device for the engine output speed, and a domestic PLC with only switch input and output as the control core of the system. The following describes the working process of the vacuum pump speed control system driven by the engine's power take-off 1, and the gear pump speed control process driven by the engine's power take-off 2 is the same:

[0027] 1) After the system is powered on, the output terminal Y1 of the PLC programmable controller 1 is connected, and the normally open point of the K2 relay 7 connected to it is energized. At this time, the power supply flowing through the motor potentiometer DC motor is negative at the top and positive at the bottom. The DC motor rotates in the opposite direction, driving the potentiometer to rotate counterclockwise until the potentiometer is at 0 point, and stops after 10 seconds. The output of the motor potentiometer center tap POT terminal is 0V, and the voltage control terminal voltage of the electronic throttle controller 9 is also 0V. At this time, the electronic throttle controls the engine to be in idle state.

[0028] 2) When the automatic throttle control is running, the output terminal Y0 of the PLC programmable controller 1 is connected, and the normally open point of the K1 relay 6 connected to it is energized. At this time, the power supply flowing through the motor potentiometer DC motor is positive at the top and negative at the bottom. The DC motor rotates forward, and the motor drives the potentiometer to rotate clockwise. The output voltage of the potentiometer POT terminal continues to increase, the engine throttle gradually increases, and the engine speed continues to increase. The proximity switch 5 for monitoring the engine speed provides a pulse signal to the vacuum pump tachometer 2. When the pulse received by the vacuum pump tachometer 2 reaches the set value, its upper limit OUT1 normally open point closes, and provides an arrival signal to the switch input X1 terminal of the PLC programmable controller 1, then the switch output terminal Y0 of the PLC programmable controller 1 is disconnected, the motor potentiometer 4 stops working, and the engine speed is maintained at the current speed.

[0029] Figure 3 In the figure, the graphical control panel of the suction and pressure conveying vehicle includes a panel without a touch screen. The upper part of the panel is integrated with three control lines for the suction and pressure conveying vehicle loading, unloading and dust removal operations. The three control lines are the loading control line, the unloading control line and the dust removal control line. Each control line has sensors and valves; each control line also has three different color indicator lights for distinguishing each control line. There is also a vacuum pump tachometer 2 in the loading control line, and a gear pump tachometer 3 in the unloading control line. The vacuum pump tachometer 2 and the gear pump tachometer 3 are placed on the upper part of the panel 1, and the lower part of the panel is integrated with the potentiometer rotating handle of the motor potentiometer 4.

[0030] Below Figure 2 The electronic throttle control system shown in the figure introduces a control method of the control system. A control method is applied to a control system that can control the engine speed. Figure 4 In the first implementation of the control method, the control method of the electronic throttle control system includes:

[0031] When the control system is powered on for the first time, the motor potentiometer rotates in the opposite direction for 10 seconds, and the electronic throttle controller controls the engine to be in idle state; when the control mode is automatic, the relationship between the set upper limit speed required and the current actual engine speed is determined. If the current actual engine speed is less than the upper limit speed set by the tachometer, the control system executes the operation of increasing the engine speed; if the current actual engine speed is greater than or equal to the upper limit speed set by the tachometer, the control system executes the operation of closing the motor potentiometer so that it no longer rotates forward.

[0032] It should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although the present invention has been described in detail in this specification with reference to the above embodiments, it should be understood by those skilled in the art that the present invention can still be modified or replaced by equivalents, and all technical solutions and improvements thereof that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. An electronic throttle control system for a suction and pressure conveying vehicle, characterized in that: The invention comprises a PLC programmable controller (1), a vacuum pump tachometer (2), a gear pump tachometer (3), a motor potentiometer (4), a proximity switch 1 (5), a K1 relay (6), a K2 relay (7), a vacuum pump speed sensor (8), an electronic throttle controller (9), a gear pump speed sensor (10), and a proximity switch 2 (11). The PLC programmable controller (1) has only a switch input / output terminal. The switch input terminal X1 of the PLC programmable controller (1) is connected to the normally open point OUT1 of the vacuum pump tachometer (2). The switch input terminal X0 of the PLC programmable controller (1) is connected to the normally open point OUT1 of the gear pump tachometer (3). The switch output terminals Y0 and Y1 of the PLC programmable controller (1) are connected to the coil ends of the K1 relay (6) and the K2 relay (7) respectively. The speed IN end of the gear pump tachometer (3) is connected to the signal output end of the proximity switch 2 (11). The speed IN end of the vacuum pump tachometer (2) is connected to the signal output end of the proximity switch 1 (5). +MV and 0V are connected to the normally open contact and normally closed contact of the K1 relay (6) and the K2 relay (7) respectively. The common end of the contacts of the K1 relay (6) and the K2 relay (7) is connected to two wiring terminals of the DC motor in the motor potentiometer (4). Among the three terminals of the potentiometer in the motor potentiometer (4), the upper end is connected to +MV, the lower end is connected to 0V and connected to the negative end of the electronic throttle controller (9), and the center tap POT end is connected to the control end of the electronic throttle controller (9). The vacuum pump speed sensor (8) is fixed on the output shaft of the power take-off 1 of the engine, and the gear pump speed sensor (10) is fixed on the output shaft of the power take-off 2 of the engine.

2. The electronic throttle control system for the suction and pressure conveying vehicle according to claim 1 is characterized in that: The + and - poles of the power supply of the PLC programmable controller (1), the vacuum pump tachometer (2), the gear pump tachometer (3), the proximity switch 1 (5), and the proximity switch 2 (11) are connected to the system power supply +24V and GND respectively.

3. The electronic throttle control system for the suction and pressure conveying vehicle according to claim 1 is characterized in that: The distance between the vacuum pump speed sensor (8) and the sensing surface of the proximity switch 1 (5) is 5-8 mm, and the distance between the gear pump speed sensor (10) and the sensing surface of the proximity switch 2 (11) is adjusted to 5-8 mm.

4. The electronic throttle control system for the suction and pressure conveying vehicle according to claim 1 is characterized in that: The motor potentiometer (4) is a device that is driven by a DC motor to rotate the potentiometer. When the DC motor rotates forward, the potentiometer rotates clockwise, and the voltage at the middle tap end of the POT gradually increases, and can reach a maximum of MV. When the DC motor rotates reversely, the potentiometer rotates counterclockwise, and the voltage at the middle tap end of the POT gradually decreases, and can reach a minimum of 0V. The potentiometer rotary handle can be manually rotated and adjusted, and the effect is the same as that of DC motor drive. The two driving modes do not affect each other, and the results of manual mechanical rotation and DC motor rotation of the potentiometer are the same. The vacuum pump tachometer (2) receives the pulse speed signal through the speed IN terminal. When the received speed signal value reaches or exceeds the value set by the electronic tachometer, the normally open contact of OUT1 is closed, and it is usually in the open state.

5. The electronic throttle control system for the suction and pressure conveying vehicle according to claim 1 is characterized in that: The electronic throttle controller (9) is a built-in device of the chassis vehicle. When the voltage at the center tap POT input terminal changes from 0.35V to 3.75V, the engine speed will change from idle speed to maximum speed, and the higher the voltage, the higher the speed.

6. A method for controlling an electronic throttle of a suction and pressure conveying vehicle, using the electronic throttle control system of a suction and pressure conveying vehicle according to any one of claims 1 to 5, characterized in that: The speed control process of the vacuum pump driven by the engine power take-off includes 1) After the system is powered on, the output terminal Y1 of the PLC programmable controller (1) is connected, and the normally open point of the K2 relay (7) connected to it is energized. At this time, the power supply flowing through the motor potentiometer DC motor is negative at the top and positive at the bottom. The DC motor rotates in the opposite direction, driving the potentiometer to rotate counterclockwise until the potentiometer reaches 0 point, and stops after T seconds. The output of the motor potentiometer center tap POT terminal is 0V, and the voltage control terminal voltage of the electronic throttle controller (9) is also 0V. At this time, the electronic throttle controls the engine to be in an idle state; 2) When the automatic throttle control is in operation, the output terminal Y0 of the PLC programmable controller (1) is connected, and the normally open point of the K1 relay (6) connected thereto is energized. At this time, the power supply flowing through the motor potentiometer DC motor is positive at the top and negative at the bottom. The DC motor rotates in the positive direction, and the motor drives the potentiometer to rotate clockwise. The output voltage of the potentiometer POT terminal continues to increase, the engine throttle gradually increases, and the engine speed continues to increase. The proximity switch 1 (5) for monitoring the engine speed provides a pulse signal to the vacuum pump tachometer (2). When the pulse received by the vacuum pump tachometer (2) reaches the set value, its upper limit OUT1 normally open point closes, and provides a reach signal to the switch input X1 terminal of the PLC programmable controller (1). Then, the switch output terminal Y0 of the PLC programmable controller (1) is disconnected, the motor potentiometer (4) stops working, and the engine speed is maintained at the current speed. The speed control process of the gear pump driven by the second power take-off of the engine is the same as the speed control process of the vacuum pump driven by the first power take-off of the engine.

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