CN105649763B

CN105649763B - Mountain cross-country device with high output torque and low noise

Info

Publication number: CN105649763B
Application number: CN201610041294.1A
Authority: CN
Inventors: 杨炳
Original assignee: Zhejiang Trail Blazer Manufacturing Co ltd
Current assignee: ZHEJIANG TRAIL-BLAZER MANUFACTURING Co.,Ltd.
Priority date: 2016-01-21
Filing date: 2016-01-21
Publication date: 2021-05-28
Anticipated expiration: 2036-01-21
Also published as: CN105649763A

Abstract

The invention discloses a mountain cross-country device with high output torque and low noise, which comprises a mountain cross-country vehicle and an engine connected with the mountain cross-country vehicle, wherein the engine is used for driving the mountain cross-country vehicle and comprises a power part, an oil injection system and a hydraulic part, the hydraulic part comprises a compression cavity, a pump cavity, a return cavity and a hydraulic loop, the compression cavity is arranged at the rear part of the engine, and is provided with a first oil port and a second oil port, the first oil port and the second oil port are respectively connected with a compression energy accumulator through a first control valve and a second control valve, the pump cavity is respectively connected with a low-pressure oil way and a high-pressure oil way through a one-way valve, and the low-pressure oil way and the low-pressure energy accumulator are; and a pressure reducing valve is arranged on an oil pipeline from the high-pressure energy accumulator to the cylinder body, and a starting valve is arranged on the oil pipeline between the compression energy accumulator and the high-pressure energy accumulator. The mountain cross-country device has the advantages of simple structure, convenience in manufacturing, high scavenging efficiency, stable performance and large output torque, and a complete control system and a position detection system are designed.

Description

Mountain cross-country device with high output torque and low noise

Technical Field

The invention relates to the field of mountain cross-country, in particular to a mountain cross-country device with high output torque and low noise.

Background

A mountain cross-country device mainly refers to a mountain cross-country vehicle and plays an important role in aspects of fire fighting, sports, mining and the like, and the mountain cross-country device plays an obvious role in treating fires in environments such as villages, forests, mountains and the like.

How to further reduce mountain cross-country device, mainly the work energy consumption of mountain cross-country car improves work efficiency, is the problem that people are always concerned about. The existing mountain off-road vehicle is basically driven by an engine, and the existing engine generally has the problems of too complex structure, inaccurate control, insufficient output torque and the like, so that the performance of the mountain off-road vehicle can be improved from the aspect.

Disclosure of Invention

In order to solve the problems, the invention provides a mountain cross-country device which is compact in structure, accurate in control, stable in performance and large in output torque.

The purpose of the invention is realized by adopting the following technical scheme:

a mountain cross-country device with high output torque and low noise comprises a mountain cross-country vehicle and an engine connected with the mountain cross-country vehicle, wherein the engine is used for driving the mountain cross-country vehicle, and is characterized in that the engine comprises a power part, an oil injection system and a hydraulic part, the power part comprises an air inlet check valve, a power piston, a combustion chamber, an oil injector and a scavenging port, the hydraulic part comprises a compression cavity, a pump cavity, a return cavity and a hydraulic loop, the compression cavity is arranged at the rear part of the engine and provided with a first oil port and a second oil port, the first oil port and the second oil port are respectively connected with a compression energy accumulator through a first control valve and a second control valve, the pump cavity is respectively connected with a low-pressure oil way and a high-pressure oil way through the check valve, the high-pressure oil way is used for supplying oil to a load of the engine, and the, an oil return check valve is arranged on the return control valve in a bypass way; the return cavity is directly connected with the high-pressure energy accumulator, a pressure reducing valve is arranged on an oil pipeline from the high-pressure energy accumulator to the cylinder body, the pressure reducing valve is kept open under starting working conditions and fire working conditions, and the pressure reducing valve is closed under normal working conditions; the compression energy accumulator is communicated with the high-pressure energy accumulator through an oil pipeline, and the oil pipeline between the compression energy accumulator and the high-pressure energy accumulator is provided with a starting valve which is used for improving the compression ratio of the engine under the starting working condition and is closed under the normal working condition; the high-pressure oil way is connected with a load energy accumulator, and a path is led out from the rear of the pressure reducing valve and is connected with the compression energy accumulator; the tail end of the engine is provided with a hydraulic balloon, the hydraulic balloon is filled with pressure oil injected in advance, the bottom of the hydraulic balloon is connected with a low-pressure energy accumulator through an oil pipeline, and a spring type safety valve is arranged between the hydraulic balloon and the low-pressure energy accumulator; an inclined dead zone oil port is arranged at the upper left of the hydraulic balloon, the straight line of the inclined dead zone oil port is tangent to the hydraulic balloon, the dead zone oil port and the compression energy accumulator are connected through a dead zone return electromagnetic valve arranged between the dead zone oil port and the compression energy accumulator, and under the working condition of fire, when the tail end of the piston assembly is located at the dead zone position between the second oil port and the hydraulic balloon, the piston assembly returns to the ideal bottom dead center area between the second oil port and the first oil port by opening the dead zone return electromagnetic valve to start the next stroke; the fuel injection system is a high-pressure common-rail type electronic control injection system and comprises a high-pressure oil pump, a common-rail pipe, an electronic control fuel injector, a pressure sensor and an electronic control unit, when an engine works, fuel enters the high-pressure oil pump through a filter under the action of the fuel delivery pump, low-pressure fuel is changed into high-pressure fuel after the high-pressure oil pump is compressed, the high-pressure fuel is input into the common-rail pipe by the high-pressure oil pump, the electronic control unit receives feedback of the pressure sensor and controls a pressure limiting valve in the common-rail pipe to adjust and keep constant pressure value in a rail, and then the high-pressure fuel is input into the electronic control fuel injector to wait for a fuel injection instruction of;

the engine also comprises a position detection system, the position detection system detects and sends out signals when the piston assembly reaches a top dead center position, a bottom dead center position and a feed-forward position through a linear displacement sensor and a position trigger sensor, the feed-forward position is positioned on one side between the top dead center position and the bottom dead center position and close to the top dead center position and is used for controlling the closing of the first control valve when a working condition piston compression stroke is started, and the feed-forward position is determined according to the speed value of the piston and matched with the position detection system; the engine also comprises a constant pressure driving system, the constant pressure driving system comprises an engine and a hydraulic variable motor, and the output oil pressure is kept constant through the motor driving torque and the load resisting torque; the hydraulic variable motor is driven by output high-pressure oil and is connected with a load through a speed reducer, and the discharge capacity of the hydraulic variable motor is automatically adjusted along with the change of working pressure;

the engine further comprises a starting control system, a normal work control system and a fire-extinguishing control system:

the starting control system is used for controlling the starting condition of the engine: when a starting signal is sent out, the starting valve and the pressure reducing valve are opened, the pressure of the compression energy accumulator is increased due to the fact that the compression energy accumulator is communicated with the high-pressure energy accumulator, and the compression ratio of the engine is improved; the engine control unit detects signals of the displacement sensor, if the detection result shows that the piston assembly is at a bottom dead center, the first control valve and the second control valve are opened, the piston assembly starts a compression stroke under the action of the compression energy accumulator, if the piston assembly is not at the bottom dead center, the return control valve is opened firstly, hydraulic oil in the pump cavity and the compression cavity is discharged through the low-pressure oil way, the piston assembly returns to the bottom dead center under the action of the pressure of the high-pressure energy accumulator, the return control valve is closed, and the compression stroke is started again; when the piston reaches a feed-forward position, the second control valve is closed, when the piston reaches a top dead center, the first control valve is closed, the return control valve is opened, after the piston assembly returns to the bottom dead center again, the return control valve is closed, the piston assembly completes a working cycle, the pressure and temperature value in the cylinder when the piston assembly reaches the top dead center are recorded in the process, when the frequency valve opening signal is sent again, whether the cylinder pressure and temperature recorded in the previous cycle meet the ignition condition of diesel oil or not is judged, if the cylinder pressure and temperature do not meet the ignition condition, the working process is repeated, and when the pressure and temperature meet the ignition condition, the control process of normal working is started;

and the normal work control system is used for controlling the normal working condition of the engine: after the engine enters a normal working condition, the starting valve and the pressure reducing valve are closed, the first control valve is kept in a normally open state, after a starting signal is sent, the second control valve is opened, hydraulic oil in the compression energy accumulator firstly enters the compression cavity through the second control valve to push the piston assembly to move towards the top dead center, after the first oil port is opened, the second control valve is closed, the compression cavity is communicated with the compression energy accumulator through the first oil port, when the piston assembly reaches an oil injection position, a sensor is triggered to generate an oil injection signal, the oil injection quantity is controlled to enable the ratio of the compression time to the expansion time to be equal to the ratio of the volume change of two strokes of the hydraulic pump, so that the expansion flow quantity is equal to the compression flow quantity to reduce the output flow pulsation of the engine, the fuel injection process is completed by an oil injection system, the fuel burns near the top dead center to release heat, and stabilizes at bottom dead center before the second control valve opens again;

the misfire control system is used for controlling the misfire condition of the engine: in the working process of the engine, after a starting signal is sent out, the position of the piston assembly is detected once, if the frequency and the frequency change rate of the engine are both smaller than set values, the position of the piston assembly is detected, if the piston assembly is not at the bottom dead center position and the cylinder temperature and cylinder pressure are smaller than a fire catching value, the engine is considered to fire in the previous cycle, at the moment, the first control valve is closed, the pressure reducing valve and the return control valve are opened, the piston assembly returns to the bottom dead center position, then the first control valve is opened, the next starting pulse signal is waited, and the engine moves according to the normal working cycle.

The invention has the beneficial effects that: 1. the hydraulic system can supply oil to the load in the compression and expansion processes, and can effectively prevent the phenomenon of oil mixing due to pressure mixing between the systems; the output flow pulsation and the noise are reduced by matching with each energy accumulator; aiming at the operation characteristics of the engine under various working conditions, a new control system is designed, so that the operation of the engine can be controlled more accurately and effectively; 2. a feed-forward position is added between the upper dead point and the lower dead point, the frequency valve is closed when the piston assembly reaches the feed-forward position under the starting working condition, and the switch valve is closed after the piston assembly reaches the upper dead point, so that the speed of a compression stroke is ensured, the resistance of an expansion stroke is reduced, the working efficiency of the engine is improved on the whole, and the stroke time is shortened; 3. the compression ratio of the engine is increased by controlling the starting valve between the high-pressure energy accumulator and the compression energy accumulator, the output oil pressure is not influenced to generate oil pressure pulsation, the starting valve is closed after normal working conditions, the traditional method for increasing the compression ratio of the oil station system is replaced, and the method has the characteristics of economy, practicability and simple structure; 4. in order to avoid the false opening of the return control valve and improve the precision degree of fire judgment, the cylinder temperature cylinder pressure and the position of a piston assembly are taken as the main judgment basis of fire, meanwhile, the delay of the reduction of the cylinder temperature is considered, a feed-forward signal of frequency and frequency change rate (or displacement change rate) is added, namely, the frequency and the frequency change rate are judged to be smaller than a set value firstly, then whether the piston is at the position of a bottom dead center is judged, and if not, the return control valve is opened; 5. a new hydraulic balloon type buffer device and an auxiliary overpressure prevention device thereof are designed, so that the functions of buffering and overpressure prevention are achieved, and meanwhile, a certain supplement effect on the hydraulic loss of an engine can be achieved; 6. through the setting of dead band hydraulic fluid port and dead band return solenoid valve, can effectively solve piston assembly and hardly get back to the problem that the lower stroke started at the dead band position, reduce the peristaltic time after piston assembly got into the dead band through tangent hydraulic fluid port setting simultaneously, further improve the whole efficiency of engine.

Drawings

The invention is further illustrated by means of the attached drawings, but the embodiments in the drawings do not constitute any limitation to the invention, and for a person skilled in the art, other drawings can be obtained on the basis of the following drawings without inventive effort.

FIG. 1 is a schematic structural diagram of an engine of the mountain cross-country device;

FIG. 2 is a schematic diagram of a fuel injection system;

FIG. 3 is a schematic diagram of the ideal bottom dead center region and the location of the dead band.

Reference numerals: 1-a compression chamber; 2-a second control valve; 3-a first control valve; 4-a compression accumulator; 5-a first oil port; 6-a second oil port; 7-pump chamber; 8-a high pressure accumulator; 9-air inlet one-way valve; 10-a power piston; 11-a combustion chamber; 12-a fuel injector; 13-a scavenging port; 14-a return cavity; 15-a return piston; 17-a return control valve; 18-a low pressure accumulator; 19-a compression piston; 21-return check valve; 22-a pressure relief valve; 23-starting a valve; 24-a load accumulator; 25-high pressure oil circuit; 26-low pressure oil circuit; 27-a hydraulic balloon; 28-mechanical safety valve; 29-an oil transfer pump; 30-a filter; 31-a high pressure oil pump; 32-common rail pipe; 33-an electrically controlled fuel injector; 34-a dead zone oil port; 35-dead zone return electromagnetic valve; a-ideal bottom dead center region; b-dead zone.

Detailed Description

The invention is further described with reference to the following examples.

Example 1: as shown in fig. 1-3, the mountain cross-country device with high output torque and low noise comprises a mountain cross-country vehicle and an engine connected with the mountain cross-country vehicle, wherein the engine is used for driving the mountain cross-country vehicle, the engine comprises a power part, an oil injection system and a hydraulic part, the power part comprises an air inlet check valve 9, a power piston 10, a combustion chamber 11, an oil injector 12, a scavenging port 13, a return piston 15 and a compression piston 19, the hydraulic part comprises a compression cavity 1, a pump cavity 7, a return cavity 14 and a hydraulic loop, the compression cavity 1 is arranged at the rear part of the engine, a first oil port 5 and a second oil port 6 are arranged on the compression cavity, the first oil port 5 and the second oil port 6 are respectively connected with a compression energy accumulator 4 through a first control valve 3 and a second control valve 2, the pump cavity 7 is respectively connected with a low-pressure oil path 26 and a high-pressure oil path 25, the high-pressure oil way 25 is used for supplying oil to the engine load, the low-pressure oil way 26 is provided with a return control valve 17 and a low-pressure energy accumulator 18, and the return control valve 17 is also provided with an oil return one-way valve 21 by way of a bypass; the return cavity 14 is directly connected with the high-pressure energy accumulator 8, and an oil pipeline from the high-pressure energy accumulator 8 to the cylinder body is provided with a pressure reducing valve 22; the compression energy accumulator 4 is communicated with the high-pressure energy accumulator 8 through an oil pipeline, and a starting valve 23 is further arranged on the oil pipeline between the compression energy accumulator 4 and the high-pressure energy accumulator 8; the high-pressure oil way 25 is connected with a load accumulator 24, and a path is led out from the rear of the pressure reducing valve 22 and is connected with the compression accumulator 4; the oil injection system is a high-pressure common-rail type electric control injection system.

The tail end of the engine is provided with a hydraulic balloon 27, the hydraulic balloon 27 is filled with pressure oil which is injected in advance and has certain pressure, the bottom of the hydraulic balloon 27 is connected with the low-pressure energy accumulator 18 through an oil pipeline, and when the load pressure is suddenly reduced or the oil injection quantity is overshot to cause the piston to pass through the second oil port 6 at a higher speed, the hydraulic balloon 27 can play a good buffering role and basically cannot generate a rebound effect; meanwhile, in order to prevent the hydraulic balloon 27 from being broken by overpressure, a spring-type safety valve 28 is arranged between the hydraulic balloon 27 and the low-pressure accumulator 18, once the spring-type safety valve 28 of the overpressure of the hydraulic balloon 27 is automatically opened and the pressure is buffered by the low-pressure accumulator 18, the hydraulic balloon 27 can play a certain role in supplementing a hydraulic system of an engine. The upper left side of the hydraulic balloon 27 is provided with an inclined dead zone oil port 34, the straight line of the inclined dead zone oil port is tangent to the hydraulic balloon 27, the dead zone oil port 34 is connected with the compression energy accumulator 4 through a dead zone return electromagnetic valve 35 arranged between the dead zone oil port 34 and the compression energy accumulator, and under the working condition of fire, when the tail end of the piston assembly is located in a dead zone B between the second oil port 6 and the hydraulic balloon 27, the piston assembly returns to an ideal bottom dead center area A between the second oil port 6 and the first oil port 5 by opening the dead zone return electromagnetic valve 35 to start the next stroke.

The high-pressure accumulator 8 serves for: firstly, when the engine is stopped, the piston assembly can be stopped at the position of the lower dead point, and the creeping is reduced; and secondly, under the starting working condition of the engine and the occurrence of a fire accident, the piston assembly is pushed to return to the position of the bottom dead center, so that the engine can continue to start the next cycle.

The engine also comprises a position detection system, the position detection system detects signals when the piston assembly reaches a top dead center position, a bottom dead center position and a feed-forward position through a linear displacement sensor and a position trigger sensor, the feed-forward position is positioned on one side between the top dead center position and the bottom dead center position and close to the top dead center position and is used for controlling the first control valve 3 to close when a working condition piston compression stroke is started, and the feed-forward position is determined according to the speed value of the piston and matched with the position detection system.

The fuel injection system comprises a high-pressure oil pump 31, a common rail pipe 32, an electric control fuel injector 33, a pressure sensor and an electronic control unit, when the engine works, fuel enters the high-pressure oil pump 31 through a filter 30 under the action of a fuel delivery pump 29, low-pressure oil is changed into high-pressure oil after being compressed by the high-pressure oil pump 31 and is input into the common rail pipe 32 by the high-pressure oil pump 31, in the common rail pipe 32, the electronic control unit receives feedback of the pressure sensor and controls a pressure limiting valve to adjust the pressure value in a rail and keep the pressure value constant, and then the high-pressure oil which is relatively stable and has certain pressure is input into the electric control fuel injector 33 to wait for a fuel injection instruction of the electronic control unit.

The engine is also provided with a constant pressure driving system which mainly comprises the engine and a hydraulic variable motor, and the constant of the output oil pressure is kept through the driving moment of the motor and the load resisting moment. The hydraulic variable motor is driven by output high-pressure oil and is connected with a load through a speed reducer, and the discharge capacity of the hydraulic variable motor is automatically adjusted along with the change of working pressure. The hydraulic variable motor is mechanically connected with a load, and the rotating speeds of the hydraulic variable motor and the load are equal; under the condition of stable operation, the driving torque of the motor is equal to the load resisting torque in opposite directions, and when the resistance is increased, the driving torque of the motor is smaller than the load resisting torque, so that the rotating speed of the motor is reduced. Since the flow rate of the output hydraulic oil is not changed, the flow resistance of the output hydraulic oil increases under the condition of increasing the back pressure, thereby causing the pressure in the system to increase. At this time, the variable mechanism of the hydraulic motor receives the feedback of the pressure increasing signal and adjusts the pressure increasing signal to increase the self-displacement, and the flow of the motor is increased under the condition of reducing the rotating speed, so that the flow resistance of the oil liquid is reduced, and the constant of the output oil liquid pressure of the engine is kept. Meanwhile, as the displacement is increased, the driving torque of the motor is increased and gradually balanced with the load resisting torque, and the system achieves a stable working state again. Similarly, when the load resistance is reduced and the hydraulic motor drive torque is greater than the load resistance torque, the motor speed is increased, causing a reduction in pressure within the hydraulic system. At the moment, the displacement of the hydraulic variable motor is adjusted in the direction of reducing, so that the driving torque and the load resisting torque are balanced, and the pressure in the system is kept constant while the system works stably.

the starting control system is used for controlling the starting condition of the engine: when a starting signal is sent out, the starting valve 23 and the pressure reducing valve 22 are opened, the pressure of the compression energy accumulator 4 is increased due to the communication with the high-pressure energy accumulator 8, and the compression ratio of the engine is improved; the engine control unit detects signals of the displacement sensor, if the detection result shows that the piston assembly is at a bottom dead center, the first control valve 3 and the second control valve 2 are opened, the piston assembly starts a compression stroke under the action of the compression energy accumulator 4, if the piston assembly is not at the bottom dead center, the return control valve 17 is firstly opened, hydraulic oil in the pump cavity 7 and the compression cavity 1 is discharged from the low-pressure oil way 26, the piston assembly returns to the bottom dead center under the action of the pressure of the high-pressure energy accumulator 8, the return control valve 17 is closed, and then the compression stroke is started; when the speed of the piston is reduced to a certain set value, the piston is considered to reach a feedforward position, the second control valve 2 is closed at the moment, after the piston reaches a top dead center, the first control valve 3 is closed, and the return control valve 17 is opened, so that the control mode of closing the first control valve 3 and the second control valve 2 step by step not only ensures the speed of a compression stroke, but also reduces the resistance of an expansion stroke; and after the piston assembly returns to the bottom dead center again, closing the return control valve 17, completing a working cycle by the piston assembly, recording the pressure and temperature values in the cylinder when the piston assembly reaches the top dead center in the process, judging whether the cylinder pressure and temperature recorded in the previous cycle meet the ignition condition of the diesel oil or not when the opening signal of the second control valve 2 is sent again, and repeating the working process until the pressure and temperature meet the ignition condition and then starting to enter the control process of normal working if the pressure and temperature in the cylinder are lower.

And the normal work control system is used for controlling the normal working condition of the engine: after the engine enters a normal working condition, the starting valve 23 and the pressure reducing valve 22 are closed, the first control valve 3 is kept in a normally open state, after a starting signal is sent, the second control valve 2 is opened, hydraulic oil in the compression energy accumulator 4 firstly enters the compression cavity 1 through the second control valve 2 to push the piston assembly to move towards a top dead center, after the first oil port 5 is opened, the second control valve 2 is closed, the compression cavity 1 is communicated with the compression energy accumulator 4 through the first oil port 5, when the piston assembly reaches an oil injection position, a sensor is triggered to generate an oil injection signal, the oil injection quantity is controlled to enable the ratio of compression time and expansion time to be equal to the ratio of volume changes of two strokes of a hydraulic pump, so that the expansion flow and the compression flow are basically equal to reduce the output flow pulsation of the engine, the fuel injection process is completed through an oil injection system, the fuel burns to release heat near the top dead center, and the piston assembly returns to, and stabilizes at bottom dead center before the second control valve 2 opens again.

The misfire control system is used for controlling the misfire condition of the engine: in the working process of the engine, after a starting signal is sent out, the position of the piston assembly is detected once, if the frequency and the frequency change rate of the engine are both smaller than set values, the position of the piston assembly is detected, if the piston assembly is not at the bottom dead center position and the cylinder temperature and cylinder pressure are smaller than a misfire value, the engine is considered to be on fire in the previous cycle, at the moment, the first control valve 3 is closed, the pressure reducing valve 22 and the repositioning control valve 17 are opened, the piston assembly is repositioned to the bottom dead center position, then the first control valve 3 is opened, the next starting pulse signal is waited, and the engine moves according to the normal working cycle.

The second control valve 2 adopts a high-frequency electro-hydraulic servo valve with the maximum flow rate of 250L/min and the opening pulse width of 10ms, the electro-hydraulic servo valve is a hydraulic control valve which receives an analog quantity electric control signal, outputs the change along with the size and the polarity of the electric control signal and has quick dynamic response and good static characteristics, such as: high resolution, small hysteresis, good linearity, etc. When the electro-hydraulic servo valve with the maximum flow rate of 250L/min and the opening pulse width of 10ms is used, the length of the acceleration section of the piston assembly is increased to about 5 times of the original length, and the time used for the compression stroke is obviously reduced, so that the motion period is reduced by nearly 7ms compared with the original length, the maximum working frequency of the engine is obviously improved, and an unexpected effect is achieved.

Example 2: as shown in fig. 1-3, the mountain cross-country device with high output torque and low noise comprises a mountain cross-country vehicle and an engine connected with the mountain cross-country vehicle, wherein the engine is used for driving the mountain cross-country vehicle, the engine comprises a power part, an oil injection system and a hydraulic part, the power part comprises an air inlet check valve 9, a power piston 10, a combustion chamber 11, an oil injector 12, a scavenging port 13, a return piston 15 and a compression piston 19, the hydraulic part comprises a compression cavity 1, a pump cavity 7, a return cavity 14 and a hydraulic loop, the compression cavity 1 is arranged at the rear part of the engine, a first oil port 5 and a second oil port 6 are arranged on the compression cavity, the first oil port 5 and the second oil port 6 are respectively connected with a compression energy accumulator 4 through a first control valve 3 and a second control valve 2, the pump cavity 7 is respectively connected with a low-pressure oil path 26 and a high-pressure oil path 25, the high-pressure oil way 25 is used for supplying oil to the engine load, the low-pressure oil way 26 is provided with a return control valve 17 and a low-pressure energy accumulator 18, and the return control valve 17 is also provided with an oil return one-way valve 21 by way of a bypass; the return cavity 14 is directly connected with the high-pressure energy accumulator 8, and an oil pipeline from the high-pressure energy accumulator 8 to the cylinder body is provided with a pressure reducing valve 22; the compression energy accumulator 4 is communicated with the high-pressure energy accumulator 8 through an oil pipeline, and a starting valve 23 is further arranged on the oil pipeline between the compression energy accumulator 4 and the high-pressure energy accumulator 8; the high-pressure oil way 25 is connected with a load accumulator 24, and a path is led out from the rear of the pressure reducing valve 22 and is connected with the compression accumulator 4; the oil injection system is a high-pressure common-rail type electric control injection system.

The second control valve 2 adopts a high-frequency electro-hydraulic servo valve with the maximum flow of 200L/min and the opening pulse width of 15ms, the electro-hydraulic servo valve is a hydraulic control valve which receives an analog quantity electric control signal, outputs the change along with the size and the polarity of the electric control signal and has quick dynamic response and good static characteristics, such as: high resolution, small hysteresis, good linearity, etc. When the electro-hydraulic servo valve with the maximum flow rate of 200L/min and the opening pulse width of 15ms is used, the length of the acceleration section of the piston assembly is increased to about 6 times of the original length, and the time for the compression stroke is obviously reduced, so that the motion period is reduced by nearly 10ms compared with the original length, the maximum working frequency of the engine is obviously improved, and an unexpected effect is achieved.

Example 3: as shown in fig. 1-3, the mountain cross-country device with high output torque and low noise comprises a mountain cross-country vehicle and an engine connected with the mountain cross-country vehicle, wherein the engine is used for driving the mountain cross-country vehicle, the engine comprises a power part, an oil injection system and a hydraulic part, the power part comprises an air inlet check valve 9, a power piston 10, a combustion chamber 11, an oil injector 12, a scavenging port 13, a return piston 15 and a compression piston 19, the hydraulic part comprises a compression cavity 1, a pump cavity 7, a return cavity 14 and a hydraulic loop, the compression cavity 1 is arranged at the rear part of the engine, a first oil port 5 and a second oil port 6 are arranged on the compression cavity, the first oil port 5 and the second oil port 6 are respectively connected with a compression energy accumulator 4 through a first control valve 3 and a second control valve 2, the pump cavity 7 is respectively connected with a low-pressure oil path 26 and a high-pressure oil path 25, the high-pressure oil way 25 is used for supplying oil to the engine load, the low-pressure oil way 26 is provided with a return control valve 17 and a low-pressure energy accumulator 18, and the return control valve 17 is also provided with an oil return one-way valve 21 by way of a bypass; the return cavity 14 is directly connected with the high-pressure energy accumulator 8, and an oil pipeline from the high-pressure energy accumulator 8 to the cylinder body is provided with a pressure reducing valve 22; the compression energy accumulator 4 is communicated with the high-pressure energy accumulator 8 through an oil pipeline, and a starting valve 23 is further arranged on the oil pipeline between the compression energy accumulator 4 and the high-pressure energy accumulator 8; the high-pressure oil way 25 is connected with a load accumulator 24, and a path is led out from the rear of the pressure reducing valve 22 and is connected with the compression accumulator 4; the oil injection system is a high-pressure common-rail type electric control injection system.

The second control valve 2 adopts a high-frequency electro-hydraulic servo valve with the maximum flow of 220L/min and the opening pulse width of 20ms, the electro-hydraulic servo valve is a hydraulic control valve which receives an analog quantity electric control signal, outputs the change along with the size and the polarity of the electric control signal and has quick dynamic response and good static characteristics, such as: high resolution, small hysteresis, good linearity, etc. When the electro-hydraulic servo valve with the maximum flow rate of 220L/min and the opening pulse width of 20ms is used, the length of the acceleration section of the piston assembly is increased to about 7 times of the original length, and the time for the compression stroke is obviously reduced, so that the motion period is reduced by nearly 12ms compared with the original length, the maximum working frequency of the engine is obviously improved, and an unexpected effect is achieved.

Example 4: as shown in fig. 1-3, the mountain cross-country device with high output torque and low noise comprises a mountain cross-country vehicle and an engine connected with the mountain cross-country vehicle, wherein the engine is used for driving the mountain cross-country vehicle, the engine comprises a power part, an oil injection system and a hydraulic part, the power part comprises an air inlet check valve 9, a power piston 10, a combustion chamber 11, an oil injector 12, a scavenging port 13, a return piston 15 and a compression piston 19, the hydraulic part comprises a compression cavity 1, a pump cavity 7, a return cavity 14 and a hydraulic loop, the compression cavity 1 is arranged at the rear part of the engine, a first oil port 5 and a second oil port 6 are arranged on the compression cavity, the first oil port 5 and the second oil port 6 are respectively connected with a compression energy accumulator 4 through a first control valve 3 and a second control valve 2, the pump cavity 7 is respectively connected with a low-pressure oil path 26 and a high-pressure oil path 25, the high-pressure oil way 25 is used for supplying oil to the engine load, the low-pressure oil way 26 is provided with a return control valve 17 and a low-pressure energy accumulator 18, and the return control valve 17 is also provided with an oil return one-way valve 21 by way of a bypass; the return cavity 14 is directly connected with the high-pressure energy accumulator 8, and an oil pipeline from the high-pressure energy accumulator 8 to the cylinder body is provided with a pressure reducing valve 22; the compression energy accumulator 4 is communicated with the high-pressure energy accumulator 8 through an oil pipeline, and a starting valve 23 is further arranged on the oil pipeline between the compression energy accumulator 4 and the high-pressure energy accumulator 8; the high-pressure oil way 25 is connected with a load accumulator 24, and a path is led out from the rear of the pressure reducing valve 22 and is connected with the compression accumulator 4; the oil injection system is a high-pressure common-rail type electric control injection system.

The second control valve 2 adopts a high-frequency electro-hydraulic servo valve with the maximum flow of 270L/min and the opening pulse width of 25ms, the electro-hydraulic servo valve is a hydraulic control valve which receives an analog quantity electric control signal, outputs the change along with the size and the polarity of the electric control signal and has quick dynamic response and good static characteristics, such as: high resolution, small hysteresis, good linearity, etc. When the electro-hydraulic servo valve with the maximum flow rate of 270L/min and the opening pulse width of 25ms is used, the maximum flow rate of the second control valve 2 is increased to about 7.5 times of the original acceleration segment length of the piston assembly, and the time for a compression stroke is obviously reduced, so that the motion period is reduced by about 12ms compared with the original motion period, the maximum working frequency of the engine is obviously improved, and an unexpected effect is achieved.

Example 5: as shown in fig. 1-3, the mountain cross-country device with high output torque and low noise comprises a mountain cross-country vehicle and an engine connected with the mountain cross-country vehicle, wherein the engine is used for driving the mountain cross-country vehicle, the engine comprises a power part, an oil injection system and a hydraulic part, the power part comprises an air inlet check valve 9, a power piston 10, a combustion chamber 11, an oil injector 12, a scavenging port 13, a return piston 15 and a compression piston 19, the hydraulic part comprises a compression cavity 1, a pump cavity 7, a return cavity 14 and a hydraulic loop, the compression cavity 1 is arranged at the rear part of the engine, a first oil port 5 and a second oil port 6 are arranged on the compression cavity, the first oil port 5 and the second oil port 6 are respectively connected with a compression energy accumulator 4 through a first control valve 3 and a second control valve 2, the pump cavity 7 is respectively connected with a low-pressure oil path 26 and a high-pressure oil path 25, the high-pressure oil way 25 is used for supplying oil to the engine load, the low-pressure oil way 26 is provided with a return control valve 17 and a low-pressure energy accumulator 18, and the return control valve 17 is also provided with an oil return one-way valve 21 by way of a bypass; the return cavity 14 is directly connected with the high-pressure energy accumulator 8, and an oil pipeline from the high-pressure energy accumulator 8 to the cylinder body is provided with a pressure reducing valve 22; the compression energy accumulator 4 is communicated with the high-pressure energy accumulator 8 through an oil pipeline, and a starting valve 23 is further arranged on the oil pipeline between the compression energy accumulator 4 and the high-pressure energy accumulator 8; the high-pressure oil way 25 is connected with a load accumulator 24, and a path is led out from the rear of the pressure reducing valve 22 and is connected with the compression accumulator 4; the oil injection system is a high-pressure common-rail type electric control injection system.

The second control valve 2 adopts a high-frequency electro-hydraulic servo valve with the maximum flow rate of 230L/min and the opening pulse width of 30ms, the electro-hydraulic servo valve is a hydraulic control valve which receives an analog quantity electric control signal, outputs the change along with the size and the polarity of the electric control signal and has quick dynamic response and good static characteristics, such as: high resolution, small hysteresis, good linearity, etc. When the electro-hydraulic servo valve with the maximum flow rate of 230L/min and the opening pulse width of 30ms is used, the length of the acceleration section of the piston assembly is increased to about 8 times of the original length, and the time of a compression stroke is obviously reduced, so that the motion period is reduced by nearly 14ms compared with the original length, the maximum working frequency of the engine is obviously improved, and an unexpected effect is achieved.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the protection scope of the present invention, although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A mountain cross-country device with high output torque and low noise comprises a mountain cross-country vehicle and an engine connected with the mountain cross-country vehicle, wherein the engine is used for driving the mountain cross-country vehicle, and is characterized in that the engine comprises a power part, an oil injection system and a hydraulic part, the power part comprises an air inlet check valve, a power piston, a combustion chamber, an oil injector and a scavenging port, the hydraulic part comprises a compression cavity, a pump cavity, a return cavity and a hydraulic loop, the compression cavity is arranged at the rear part of the engine and provided with a first oil port and a second oil port, the first oil port and the second oil port are respectively connected with a compression energy accumulator through a first control valve and a second control valve, the pump cavity is respectively connected with a low-pressure oil way and a high-pressure oil way through the check valve, the high-pressure oil way is used for supplying oil to a load of the engine, and the, an oil return check valve is arranged on the return control valve in a bypass way; the return cavity is directly connected with the high-pressure energy accumulator, a pressure reducing valve is arranged on an oil pipeline from the high-pressure energy accumulator to the cylinder body, the pressure reducing valve is kept open under starting working conditions and fire working conditions, and the pressure reducing valve is closed under normal working conditions; the compression energy accumulator is communicated with the high-pressure energy accumulator through an oil pipeline, and the oil pipeline between the compression energy accumulator and the high-pressure energy accumulator is provided with a starting valve which is used for improving the compression ratio of the engine under the starting working condition and is closed under the normal working condition; the high-pressure oil way is connected with a load energy accumulator, and a path is led out from the rear of the pressure reducing valve and is connected with the compression energy accumulator; the tail end of the engine is provided with a hydraulic balloon, the hydraulic balloon is filled with pressure oil injected in advance, the bottom of the hydraulic balloon is connected with a low-pressure energy accumulator through an oil pipeline, and a spring type safety valve is arranged between the hydraulic balloon and the low-pressure energy accumulator; an inclined dead zone oil port is arranged at the upper left of the hydraulic balloon, the straight line of the inclined dead zone oil port is tangent to the hydraulic balloon, the dead zone oil port and the compression energy accumulator are connected through a dead zone return electromagnetic valve arranged between the dead zone oil port and the compression energy accumulator, and under the working condition of fire, when the tail end of the piston assembly is located at the dead zone position between the second oil port and the hydraulic balloon, the piston assembly returns to the ideal bottom dead center area between the second oil port and the first oil port by opening the dead zone return electromagnetic valve to start the next stroke; the fuel injection system is a high-pressure common-rail type electronic control injection system and comprises a high-pressure oil pump, a common-rail pipe, an electronic control fuel injector, a pressure sensor and an electronic control unit, when an engine works, fuel enters the high-pressure oil pump through a filter under the action of the fuel delivery pump, low-pressure fuel is changed into high-pressure fuel after the high-pressure oil pump is compressed, the high-pressure fuel is input into the common-rail pipe by the high-pressure oil pump, the electronic control unit receives feedback of the pressure sensor and controls a pressure limiting valve in the common-rail pipe to adjust and keep constant pressure value in a rail, and then the high-pressure fuel is input into the electronic control fuel injector to wait for a fuel injection instruction of;

the engine further comprises a normal operation control system and a misfire control system:

the misfire control system is used for controlling the misfire condition of the engine: in the working process of the engine, after a starting signal is sent out, the position of a piston assembly is detected once, if the frequency and the frequency change rate of the engine are both smaller than set values, the position of the piston assembly is detected, if the piston assembly is not at the bottom dead center position and the cylinder temperature and cylinder pressure are smaller than a fire catching value, the engine is considered to fire in the previous cycle, at the moment, a first control valve is closed, a pressure reducing valve and a return control valve are opened, the piston assembly returns to the bottom dead center position, then the first control valve is opened, the next starting pulse signal is waited, and the engine moves according to the normal working cycle;

the second control valve adopts a high-frequency electro-hydraulic servo valve with the maximum flow rate of 270L/min, and the opening pulse width of the high-frequency electro-hydraulic servo valve is 10 ms; the system also comprises a starting control system for controlling the starting working condition of the engine: when a starting signal is sent out, the starting valve and the pressure reducing valve are opened, the pressure of the compression energy accumulator is increased due to the fact that the compression energy accumulator is communicated with the high-pressure energy accumulator, and the compression ratio of the engine is improved; the engine control unit detects signals of the displacement sensor, if the detection result shows that the piston assembly is at a bottom dead center, the first control valve and the second control valve are opened, the piston assembly starts a compression stroke under the action of the compression energy accumulator, if the piston assembly is not at the bottom dead center, the return control valve is opened firstly, hydraulic oil in the pump cavity and the compression cavity is discharged through the low-pressure oil way, the piston assembly returns to the bottom dead center under the action of the pressure of the high-pressure energy accumulator, the return control valve is closed, and the compression stroke is started again; when the piston reaches the feedforward position, the second control valve is closed, when the piston reaches the top dead center, the first control valve is closed, the return control valve is opened, after the piston assembly returns to the bottom dead center again, the return control valve is closed, the piston assembly completes a working cycle, in the process, the pressure and temperature value in the cylinder when the piston assembly reaches the top dead center are recorded, when the frequency valve opening signal is sent again, whether the cylinder pressure and temperature recorded in the previous cycle meet the ignition condition of diesel oil or not is judged, if the cylinder pressure and temperature do not meet the ignition condition, the working process is repeated until the pressure and temperature meet the ignition condition, and then the control process of normal working is started.