Air pressure balance system, engineering machinery, control method, storage medium and chip

Abstract

An embodiment of the present invention provides an air pressure balance system, engineering machinery, control method, storage medium and chip. The system includes a hydraulic oil tank, having an exhalation port, an intake port and a pressure measuring port; a first sensor, arranged at the pressure measuring port; an air cylinder; an electromagnetic reversing valve, having first, second and third interfaces, the first interface is connected to the outside, the second interface is connected to the exhalation port, and the third interface is connected to the air cylinder; a second sensor, arranged at the air cylinder; a proportional throttle valve, connected to the air cylinder and the intake port; a controller, connected to the first sensor to determine the first air pressure of the hydraulic oil tank, connected to the second sensor to determine the second air pressure of the air cylinder, connected to the electromagnetic reversing valve and the proportional throttle valve, the controller controls the opening and closing of the electromagnetic reversing valve or the proportional throttle valve according to the first air pressure and the second air pressure, so that the absolute value of the difference between the first air pressure and the initial air pressure is not greater than the first threshold value, and the second air pressure is within a preset range.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of air pressure balance, and in particular, to an air pressure balance system, an engineering machine, an air pressure balance control method, a computer-readable storage medium, and a chip. Background Art

[0002] According to statistics, more than 70% of the faults in hydraulic systems are caused by the contamination of hydraulic oil. Therefore, it is particularly important to control the contamination of hydraulic oil. Mining equipment is used in very harsh working conditions and is often used in dusty, high temperature, humid environments. During the operation of the equipment, in order to maintain the pressure balance inside and outside the hydraulic oil tank, the hydraulic oil tank needs to frequently exchange gas with the external environment. During the gas exchange process, fine solid particles and water vapor that are not filtered out by the filter element will enter the interior of the hydraulic oil tank with the air, causing the solid contamination level of the hydraulic oil to exceed the standard, the oil quality to deteriorate rapidly, and increase the number of faults in the hydraulic system.

[0003] In order to solve the above problems, mining equipment in related art adopts a pressure-maintaining hydraulic oil tank equipped with a breathing valve. This type of hydraulic oil tank can directly exchange air with the outside world. Summary of the invention

[0004] In order to solve or improve at least one of the above technical problems, an object of an embodiment of the present invention is to provide an air pressure balancing system.

[0005] Another object of an embodiment of the present invention is to provide an engineering machine having the above-mentioned air pressure balancing system.

[0006] Another object of an embodiment of the present invention is to provide a gas pressure balance control method.

[0007] Another object of an embodiment of the present invention is to provide a computer-readable storage medium.

[0008] Another object of an embodiment of the present invention is to provide a chip.

[0009] To achieve the above-mentioned purpose, an embodiment of the first aspect of the present invention provides an air pressure balancing system, including: a hydraulic oil tank for storing hydraulic medium, the hydraulic oil tank having an exhalation port, an inhalation port and a pressure measuring port; a first sensor, arranged at the pressure measuring port, the first sensor being used to monitor the air pressure in the hydraulic oil tank; an air storage cylinder for storing gas; an electromagnetic reversing valve, the electromagnetic reversing valve having a first interface, a second interface and a third interface, the first interface being connected to the outside, the second interface being connected to the exhalation port, and the third interface being connected to the air storage cylinder; a second sensor being arranged at the air storage cylinder, the second sensor being used to monitor the pressure in the air storage cylinder air pressure; a proportional throttle valve connected to the air reservoir, the proportional throttle valve connected to the air intake port; a controller connected to a first sensor to determine a first air pressure of the hydraulic oil tank, the controller connected to a second sensor to determine a second air pressure of the air reservoir, the controller connected to the electromagnetic reversing valve, and the controller connected to the proportional throttle valve, the controller can control the opening and closing of the electromagnetic reversing valve or the proportional throttle valve according to the first air pressure and the second air pressure, so that the absolute value of the difference between the first air pressure and the initial air pressure of the hydraulic oil tank is not greater than a first threshold value, and the second air pressure is within a preset range.

[0010] According to the embodiments of the air pressure balancing system provided by the present invention, on the first hand, air can circulate between the air storage cylinder and the hydraulic oil tank, and the hydraulic oil tank does not directly exchange gas with the outside world, thereby minimizing the possibility of external air contaminating the hydraulic system; on the second hand, the hydraulic oil tank, air storage cylinder and other components can be arranged separately, which is conducive to rational layout in a small space and convenient installation; on the third hand, the relative pressure of the air in the hydraulic oil tank is very small, almost zero, and the pressure load applied to the inner wall of the hydraulic oil tank can be ignored, which is conducive to extending the service life of the hydraulic oil tank; on the fourth hand, there is no air back pressure in the hydraulic oil tank, and the return oil pipeline of the pump and valve group is smooth, which is conducive to the stable operation of the system; on the fifth hand, the air pressure balancing system can be applied to engineering machinery with extremely harsh working conditions, and has wider versatility.

[0011] Specifically, the air pressure balance system includes a hydraulic oil tank, a first sensor, an air reservoir, an electromagnetic reversing valve, a second sensor, a proportional throttle valve and a controller. The hydraulic oil tank is used to store hydraulic medium, and the hydraulic medium can be a medium such as hydraulic oil. Optionally, the hydraulic oil tank has an oil suction port and an oil return port, and the hydraulic medium flows from the oil suction port to the hydraulic system, and the hydraulic medium can flow back to the hydraulic oil tank from the oil return port. Further, the hydraulic oil tank has an exhalation port, an air intake port and a pressure measuring port. Optionally, the exhalation port, the air intake port and the pressure measuring port are all located at the top of the hydraulic oil tank. The exhalation port is connected to the gas in the hydraulic oil tank, and the air intake port is connected to the gas in the hydraulic oil tank. Further, the first sensor is arranged at the pressure measuring port. The first sensor is used to monitor the air pressure in the hydraulic oil tank. The air reservoir is used to store gas. Further, the electromagnetic reversing valve has a first interface, a second interface and a third interface. The first interface of the electromagnetic reversing valve is used to communicate with the outside world, the second interface of the electromagnetic reversing valve is used to communicate with the exhalation port of the hydraulic oil tank, and the third interface of the electromagnetic reversing valve is used to connect with the air reservoir. The third interface is selectively connected to the first interface or the second interface. When the third interface is connected to the first interface, the electromagnetic reversing valve is in the first position, and the electromagnetic reversing valve is connected to the outside world; when the third interface is connected to the second interface, the electromagnetic reversing valve is in the second position, and the electromagnetic reversing valve is connected to the exhalation port.

[0012] Further, the second sensor is provided in the air reservoir. The second sensor is used to monitor the air pressure in the air reservoir. The proportional throttle valve is connected to the air reservoir, and the proportional throttle valve is connected to the air intake port of the hydraulic oil tank. Further, the controller is connected to the first sensor to determine the first air pressure of the hydraulic oil tank. The controller can obtain the first air pressure information about the hydraulic oil tank from the first sensor, and the controller determines the first air pressure of the hydraulic oil tank according to the first air pressure information. Further, the controller is connected to the second sensor to determine the second air pressure of the air reservoir. The controller can obtain the second air pressure information about the air reservoir from the second sensor, and the controller determines the second air pressure of the air reservoir according to the second air pressure information. Further, the controller can control the opening and closing of the electromagnetic reversing valve or the proportional throttle valve according to the first air pressure and the second air pressure. Specifically, it is determined whether the second air pressure is within a preset interval, and a first judgment result is generated, the left end point of the preset interval is the second threshold value, and the right end point of the preset interval is the third threshold value. In other words, it is determined whether the second air pressure is not less than the second threshold value and not greater than the third threshold value at the same time, and a first judgment result is generated. If the first judgment result is yes, the electromagnetic reversing valve is controlled to be in the second position, at which time the third interface is connected to the first interface, and the electromagnetic reversing valve is connected to the exhalation port; if the first judgment result is no, the electromagnetic reversing valve is controlled to be in the first position, the third interface is connected to the first interface, the electromagnetic reversing valve is connected to the outside, and the outside gas enters the air reservoir until the first judgment result is yes. It is worth noting that the air reservoir is connected to the safety valve. When the pressure in the air reservoir exceeds the third threshold, the safety valve is connected to the outside to keep the second air pressure within the preset range. Therefore, the air pressure in the air reservoir (the second air pressure) generally does not exceed the third threshold. Further, it is determined whether the absolute value of the difference between the first air pressure and the initial air pressure of the hydraulic oil tank is greater than the first threshold, and a second judgment result is generated. If the second judgment result is yes, it is further determined whether the air pressure difference is a negative value, and a third judgment result is generated; if the second judgment result is no, the first air pressure and the air pressure difference are continued to be obtained. If the third judgment result is yes, it means that the air pressure (first air pressure) in the hydraulic oil tank is negative pressure and the air pressure change value is greater than the first threshold value. The controller controls the proportional throttle valve to open so that the compressed air in the air reservoir enters the hydraulic oil tank until the absolute value of the air pressure difference is not greater than the first threshold value. If the third judgment result is no, it means that the air pressure in the hydraulic oil tank is positive pressure and the air pressure change value is greater than the first threshold value. The controller controls the air compressor to extract the gas in the hydraulic oil tank until the absolute value of the air pressure difference is not greater than the first threshold value. Finally, it is judged again whether the second air pressure is less than the second threshold value to generate the sixth judgment result.If the sixth judgment result is yes, the electromagnetic reversing valve is controlled to be in the first position, the third interface is connected to the first interface, the electromagnetic reversing valve is connected to the outside world, and the controller controls the air compressor to extract gas from the outside atmosphere; if the sixth judgment result is no, the air pressure is balanced.

[0013] By operating the controller to control the opening and closing of the electromagnetic reversing valve or the proportional throttle valve, air pressure balance is achieved, the absolute value of the difference between the first air pressure and the initial air pressure of the hydraulic oil tank is not greater than the first threshold, and the second air pressure is within a preset range.

[0014] In the technical solution defined in the present invention, on the first aspect, air can circulate between the air reservoir and the hydraulic oil tank, and the hydraulic oil tank does not directly exchange gas with the outside world, thereby minimizing the possibility of external air contaminating the hydraulic system; on the second aspect, the hydraulic oil tank, air reservoir and other components can be arranged separately, which is conducive to rational layout in a small space and convenient installation; on the third aspect, the relative pressure of the air in the hydraulic oil tank is very small, almost zero, and the pressure load applied to the inner wall of the hydraulic oil tank can be ignored, which is conducive to extending the service life of the hydraulic oil tank; on the fourth aspect, there is no air back pressure in the hydraulic oil tank, and the return oil pipeline of the pump and valve group is smooth, which is conducive to the stable operation of the system; on the fifth aspect, the air pressure balance system can be applied to engineering machinery with extremely harsh working conditions, and has wider versatility.

[0015] In addition, the above technical solution provided by the present invention may also have the following additional technical features:

[0016] In the above technical solution, the first interface is connected to the outside world through the first air path, and the second interface is connected to the exhalation port through the second air path. When the third interface is connected to the first interface, the solenoid reversing valve is in the first position, and the solenoid reversing valve is connected to the outside world; when the third interface is connected to the second interface, the solenoid reversing valve is in the second position, and the solenoid reversing valve is connected to the exhalation port.

[0017] In this technical solution, the first interface of the electromagnetic reversing valve is used to communicate with the outside world, the second interface of the electromagnetic reversing valve is used to communicate with the exhalation port of the hydraulic oil tank, and the third interface of the electromagnetic reversing valve is used to connect with the air reservoir. The third interface is selectively connected to the first interface or the second interface, so that the air reservoir can selectively communicate with the hydraulic oil tank or the outside atmosphere through the electromagnetic reversing valve to achieve the purpose of dynamic adjustment and control.

[0018] The above technical solution also includes: an air compressor connected to the third interface, and the air compressor is connected to the air storage cylinder.

[0019] In this technical solution, the air pressure balance system also includes an air compressor. Specifically, the air compressor is connected to the third interface of the electromagnetic reversing valve, and the air compressor is connected to the air cylinder. When the electromagnetic reversing valve is in the first position, the electromagnetic reversing valve is connected to the outside world, and the air compressor extracts the outside atmosphere and compresses it, and then delivers the compressed gas to the air cylinder. When the electromagnetic reversing valve is in the second position, the electromagnetic reversing valve is connected to the exhalation port, and the air compressor extracts the gas in the hydraulic oil tank and compresses it, and then delivers the compressed gas to the air cylinder. By setting up an air compressor, the air can be compressed, and the air is in a compressed state in the air cylinder, which can reduce the volume of the air cylinder and the volume of the hydraulic oil tank. The hydraulic oil tank, air cylinder and other components can be arranged separately, which is conducive to rational layout in a small space and convenient installation.

[0020] The above technical solution also includes: an oil removal filter, which is arranged in the second gas path.

[0021] In the technical solution, the air pressure balance system also includes an oil removal filter. Specifically, the oil removal filter is arranged in the second air path. When the third interface is connected to the second interface, the electromagnetic reversing valve is in the second position, and the electromagnetic reversing valve is connected to the exhalation port. After the air compressor extracts the gas in the hydraulic oil tank for compression, the compressed gas is delivered to the air storage cylinder. When the air compressor extracts the gas in the hydraulic oil tank, some oil mist or water droplets will be attached, and the oil removal filter can filter out this part of the oil mist or water droplets. Specifically, the oil removal filter is mainly composed of a cyclone separation section, an inertial demister pre-filter box, a fine filter element, a drain valve, a pressure and temperature gauge, and the air carrying oil and water enters the oil removal filter in a tangential direction from the intake pipe. The mixture is separated by the cyclone of the oil removal filter, and part of the hydraulic oil and water are separated. After that, the gas and liquid are further separated under the action of inertial collision. After the pre-filter box, the dust with larger particle size in the gas is filtered out, which plays a protective role for the post-stage fine filter element. The gas passes through the fine filter element, and solid particles with a particle size greater than 1 micron are filtered out; the oil mist and water mist with a tiny particle size are collected on the fine filter element and condensed into larger droplets, which settle to the bottom of the fine filter tube under the action of gravity. The separated oil and water are discharged from each sewage outlet, and the gas is output from the gas outlet at the top.

[0022] The above technical solution also includes: an air filter, which is arranged in the first air path.

[0023] In the technical solution, the air pressure balance system also includes an air filter. Specifically, the air filter is arranged in the first air path. When the third interface is connected to the first interface, the electromagnetic reversing valve is in the first position, and the electromagnetic reversing valve is connected to the outside. After the air compressor extracts the external gas and compresses it, the compressed gas is delivered to the air storage cylinder. The air filter is used to filter impurities in the air to avoid contaminating the hydraulic system.

[0024] In the above technical solution, the proportional throttle valve is connected to the air storage cylinder through the third air path, and the air pressure balance system also includes: an air dryer, which is arranged in the third air path.

[0025] In this technical solution, the air pressure balance system also includes an air dryer. Specifically, the proportional throttle valve is connected to the air reservoir through the third air circuit. The air dryer is arranged in the third air circuit. The air pressure (first air pressure) in the hydraulic oil tank is a negative pressure and the air pressure change value is greater than the first threshold value. The controller controls the proportional throttle valve to open so that the compressed air in the air reservoir enters the hydraulic oil tank until the absolute value of the air pressure difference is no greater than the first threshold value. The air dryer is used to remove impurities such as water mist in the gas to reduce the possibility of polluting the hydraulic system.

[0026] The above technical solution also includes: an oil-water separator connected to the air compressor, and the oil-water separator is connected to the air storage cylinder.

[0027] In this technical solution, the air pressure balance system also includes an oil-water separator. Specifically, the oil-water separator is connected to the air compressor, and the oil-water separator is connected to the air storage cylinder. After the air compressor compresses the gas, the compressed gas needs to pass through the oil-water separator in the process of being transported to the air storage cylinder. The oil-water separator is used to separate the oil and water entrained in the gas to ensure the purity of the gas and reduce the possibility of impurities entering the hydraulic oil tank with the gas and contaminating the hydraulic system.

[0028] The above technical solution also includes: a one-way valve connected to the air compressor, the one-way valve is connected to the air storage cylinder through a fourth air path, and the gas can flow from the air compressor to the air storage cylinder through the one-way valve.

[0029] In this technical solution, the air pressure balance system also includes a one-way valve. Specifically, the one-way valve is connected to the air compressor. Optionally, an oil-water separator is arranged between the one-way valve and the air compressor, that is, the oil-water separator is connected to the air compressor, and the oil-water separator is connected to the one-way valve. Furthermore, the one-way valve is connected to the air cylinder through a fourth air path, and the gas can flow from the air compressor to the air cylinder through the one-way valve. By providing a one-way valve, the gas in the air cylinder can be prevented from flowing back to the air compressor, and the resistance encountered by the air compressor in the process of delivering gas to the air cylinder can also be reduced.

[0030] The above technical solution also includes: a safety valve connected to the fourth gas path, and the safety valve is connected to the outside.

[0031] In this technical solution, the air pressure balance system further includes a safety valve. Specifically, the safety valve is connected to the fourth air path, and the safety valve is communicated with the outside. The air reservoir is connected to the safety valve, and when the pressure in the air reservoir exceeds the third threshold, the safety valve is communicated with the outside to keep the second air pressure within a preset range, so that the air pressure in the air reservoir (the second air pressure) generally does not exceed the third threshold.

[0032] The above technical solution also includes: a drain valve, which is arranged on the air storage cylinder.

[0033] In the technical solution, the air pressure balance system further includes a drain valve. Specifically, the drain valve is arranged on the air storage cylinder. Optionally, the drain valve is located at the bottom of the air storage cylinder. The drain valve can regularly discharge condensed water at the bottom of the air storage cylinder.

[0034] In the above technical solution, the hydraulic oil tank also has an oil filling port and an exhaust port. The oil filling port is arranged at the top of the hydraulic oil tank, and the exhaust port is arranged at one side of the hydraulic oil tank.

[0035] In this technical solution, when the hydraulic oil tank is used for the first time, the exhaust port is opened, hydraulic oil is added from the oil filling port, the liquid level is observed through the oil window, and after the liquid level reaches the required height, the exhaust port and the oil filling port are closed.

[0036] In the above technical solution, the hydraulic oil tank also has an oil window, which is arranged on one side of the hydraulic oil tank; or the hydraulic oil tank also has an oil suction port and an oil return port, which are arranged on one side of the hydraulic oil tank and the oil return port is arranged on the other side of the hydraulic oil tank.

[0037] In this technical solution, by providing an oil window, the staff can observe the liquid level through the oil window.

[0038] Furthermore, the hydraulic oil tank has an oil suction port and an oil return port, and the working medium in the hydraulic oil tank can flow to the hydraulic system through the oil suction port, and the hydraulic medium can flow back to the inside of the hydraulic oil tank through the oil return port. By arranging the oil suction port and the oil return port on opposite sides of the hydraulic oil tank, on the one hand, it is conducive to a reasonable spatial layout to avoid interference between the oil suction line and the oil return line; on the other hand, the oil suction port and the oil return port are far away from each other, which is used to prevent or reduce the impact of bubbles caused by splashing on the oil pump and the oil circuit; furthermore, the temperature of the working medium can be reduced to a certain extent.

[0039] An embodiment of the second aspect of the present invention provides an engineering machinery, comprising: a frame; and a pneumatic balance system in any of the above embodiments, wherein a hydraulic oil tank, an air storage cylinder and a controller of the pneumatic balance system are all connected to the frame.

[0040] According to an embodiment of the engineering machinery of the present invention, the engineering machinery includes a frame and the air pressure balance system in any of the above embodiments. The hydraulic oil tank, air reservoir and controller of the air pressure balance system are all connected to the frame. The air pressure balance system in the present invention can be applied to engineering machinery with extremely harsh working conditions, such as mining equipment, etc., and has wider versatility.

[0041] Among them, since the engineering machinery includes any of the air pressure balance systems in the first aspect above, it has the beneficial effects of any of the above embodiments, which will not be described in detail here.

[0042] An embodiment of the third aspect of the present invention provides a gas pressure balance control method, which is used for a controller of a gas pressure balance system in any of the above embodiments, comprising: obtaining first air pressure information about a hydraulic oil tank of the gas pressure balance system from a first sensor of the gas pressure balance system, and obtaining second air pressure information about an air storage cylinder of the gas pressure balance system from a second sensor of the gas pressure balance system; determining the first air pressure of the hydraulic oil tank according to the first air pressure information, and determining the second air pressure of the air storage cylinder according to the second air pressure information; judging whether the second air pressure is within a preset interval, and generating a first judgment result, wherein the left end point of the preset interval is a second threshold value, and the right end point of the preset interval is a third threshold value; if the first judgment result is yes, then controlling the electromagnetic reversing valve of the gas pressure balance system to be in the second position; if the first judgment result is no, then controlling the electromagnetic reversing valve of the gas pressure balance system to be in the first position, and controlling the air compressor of the gas pressure balance system to extract gas from the outside atmosphere until the first judgment result is yes; subtracting the initial air pressure of the hydraulic oil tank from the first air pressure to obtain an air pressure difference; judging whether the absolute value of the air pressure difference is greater than the first threshold value, and generating a second judgment result; if the second judgment result is yes , then further determine whether the air pressure difference is a negative value, and generate a third determination result; if the second determination result is no, then return to subtracting the initial air pressure of the hydraulic oil tank from the first air pressure to obtain the air pressure difference; if the third determination result is yes, then open the proportional throttle valve of the air pressure balance system to allow the compressed air in the air reservoir to enter the hydraulic oil tank; determine whether the absolute value of the air pressure difference is not greater than the first threshold value, and generate a fourth determination result; if the fourth determination result is yes, then close the proportional throttle valve; if the fourth determination result is no, then return to open the proportional throttle valve of the air pressure balance system; if the third determination result is no , then control the air compressor to extract the gas in the hydraulic oil tank; determine whether the absolute value of the air pressure difference is not greater than the first threshold value, and generate a fifth judgment result; if the fifth judgment result is yes, turn off the air compressor; if the fifth judgment result is no, return to control the air compressor to extract the gas in the hydraulic oil tank; determine whether the second air pressure is less than the second threshold value, and generate a sixth judgment result; if the sixth judgment result is yes, return to control the electromagnetic reversing valve of the air pressure balance system to be in the first position, and control the air compressor of the air pressure balance system to extract gas from the outside atmosphere; if the sixth judgment result is no, the air pressure is balanced.

[0043] According to an embodiment of the air pressure balance control method of the present invention, the air pressure balance control method is used in a controller of an air pressure balance system in any of the above embodiments. The specific steps of the air pressure balance control method include:

[0044] The first step is to obtain first air pressure information about the hydraulic oil tank of the air pressure balance system from a first sensor of the air pressure balance system, and obtain second air pressure information about the air reservoir of the air pressure balance system from a second sensor of the air pressure balance system. The controller obtains the pressure information from the sensor and analyzes the pressure information;

[0045] The second step is to determine the first air pressure of the hydraulic oil tank according to the first air pressure information, and determine the second air pressure of the air reservoir according to the second air pressure information. The controller can determine the real-time air pressure in the hydraulic oil tank or the air reservoir according to the acquired pressure information;

[0046] The third step is to determine whether the second air pressure is within the preset interval and generate a first judgment result. The left end point of the preset interval is the second threshold value, and the right end point of the preset interval is the third threshold value. Determine whether the air pressure (second air pressure) in the air reservoir is not less than the second threshold value and not greater than the third threshold value. Set the maximum air pressure in the air reservoir to a fixed value P max , the minimum air pressure is a fixed value P min , the second air pressure is P2. This step is used to determine P min ≤P2≤P max ;

[0047] Step 4: If the first judgment result is yes, the electromagnetic reversing valve of the air pressure balance system is controlled to be in the second position. If the air pressure in the air reservoir (the second air pressure) is not less than the second threshold value and not greater than the third threshold value, the controller controls the electromagnetic reversing valve to be in the second position, at which time the third interface is connected to the first interface, and the electromagnetic reversing valve is connected to the exhalation port;

[0048] Step 5. If the first judgment result is no, then the electromagnetic reversing valve of the air pressure balance system is controlled to be in the first position, and the air compressor of the air pressure balance system is controlled to extract gas from the outside atmosphere until the first judgment result is yes. If the second air pressure is not within the preset interval, it can be understood that the air pressure in the air cylinder is lower than the second threshold at this time. Then the controller controls the electromagnetic reversing valve to be in the first position, the third interface is connected to the first interface, the electromagnetic reversing valve is connected to the outside world, and the outside gas enters the air cylinder until the first judgment result is yes. It is worth noting that the air cylinder is connected to the safety valve. When the pressure in the air cylinder exceeds the third threshold, the safety valve is connected to the outside world to keep the second air pressure within the preset interval. Therefore, the air pressure in the air cylinder (the second air pressure) generally does not exceed the third threshold.

[0049] Step 6, subtracting the initial air pressure of the hydraulic oil tank from the first air pressure to obtain an air pressure difference;

[0050] Step 7: Determine whether the absolute value of the air pressure difference is greater than the first threshold value, and generate a second judgment result. Determine whether the absolute value of the difference between the first air pressure and the initial air pressure is greater than a preset value. The first air pressure is P1, and P1 is a positive or negative value. Set the minimum starting pressure difference of the controller to △P, and △P is a positive value. The control target of the controller is -△P≤P1≤+△P(|P1|≤△P);

[0051] Step 8: If the second judgment result is yes, further judge whether the air pressure difference is a negative value, and generate a third judgment result. If the absolute value of the air pressure difference is greater than the first threshold, the controller needs to adjust the air pressure in the hydraulic oil tank, and further judge whether the first air pressure is positive or negative of P1;

[0052] Step 9: If the second judgment result is no, return to subtract the initial air pressure of the hydraulic oil tank from the first air pressure to obtain the air pressure difference. If the absolute value of the air pressure difference is not greater than the first threshold, the controller does not need to adjust the air pressure in the hydraulic oil tank. At this time, the controller continues to obtain the first air pressure and the air pressure difference;

[0053] Step 10: If the third judgment result is yes, the proportional throttle valve of the air pressure balance system is opened to allow the compressed air in the air reservoir to enter the hydraulic oil tank. If the air pressure in the hydraulic oil tank (the first air pressure) is negative pressure and the air pressure change value is greater than the first threshold, the controller controls the proportional throttle valve to open to allow the compressed air in the air reservoir to enter the hydraulic oil tank until the absolute value of the air pressure difference is no greater than the first threshold;

[0054] Step 11: determine whether the absolute value of the air pressure difference is not greater than the first threshold value, and generate a fourth determination result. Based on the fourth determination result, the controller determines whether to continue to open the proportional throttle valve;

[0055] Step 12: If the fourth judgment result is yes, close the proportional throttle valve. If the air pressure in the hydraulic oil tank (the first air pressure) is negative pressure and the air pressure change value is not greater than the first threshold, the controller does not need to adjust the air pressure in the hydraulic oil tank, and the proportional throttle valve is closed at this time;

[0056] Step 13: If the result of the fourth judgment is no, then return to open the proportional throttle valve of the air pressure balance system. If the air pressure (first air pressure) in the hydraulic oil tank is negative pressure and the air pressure change value is greater than the first threshold, the controller controls the proportional throttle valve to open so that the compressed air in the air reservoir enters the hydraulic oil tank until the absolute value of the air pressure difference is no greater than the first threshold;

[0057] Step 14: If the third judgment result is no, the air compressor is controlled to extract the gas in the hydraulic oil tank. If the air pressure in the hydraulic oil tank is positive pressure and the air pressure change value is greater than the first threshold, the controller controls the air compressor to extract the gas in the hydraulic oil tank until the absolute value of the air pressure difference is not greater than the first threshold;

[0058] Step 15: determine whether the absolute value of the air pressure difference is not greater than the first threshold value, and generate a fifth judgment result. Based on the fifth judgment result, the controller determines whether to continue to turn on the air compressor;

[0059] Step 16: If the result of the fifth judgment is yes, turn off the air compressor. If the air pressure change value in the hydraulic oil tank is not greater than the first threshold value, the controller does not need to adjust the air pressure in the hydraulic oil tank, and the controller turns off the air compressor;

[0060] Step 17: If the result of the fifth judgment is no, then return to control the air compressor to extract the gas in the hydraulic oil tank. If the pressure change value in the hydraulic oil tank is greater than the first threshold, the controller needs to adjust the air pressure in the hydraulic oil tank, and at this time the controller controls the air compressor to continue to turn on;

[0061] Step 18, judging whether the second air pressure is less than the second threshold value, and generating the sixth judgment result. After the controller controls the proportional throttle valve to open, the compressed air in the air reservoir enters the hydraulic oil tank, and the air pressure in the air reservoir will decrease. To avoid the second air pressure being too low, the sixth judgment result is generated;

[0062] Step 19: If the result of the sixth judgment is yes, the electromagnetic reversing valve of the air pressure balance system is returned to the first position, and the air compressor of the air pressure balance system is controlled to extract gas from the outside atmosphere. If the air pressure in the air reservoir is lower than the second threshold, the controller controls the electromagnetic reversing valve to be in the first position, the third interface is connected to the first interface, the electromagnetic reversing valve is connected to the outside, and the outside gas enters the air reservoir until the result of the sixth judgment is no;

[0063] Step 20: If the sixth judgment result is no, the air pressure is balanced. At this time, the absolute value of the difference between the first air pressure and the initial air pressure of the hydraulic oil tank is not greater than the first threshold, and the second air pressure is within the preset range, indicating that the air pressure is balanced.

[0064] In the technical solution defined in the present invention, air can circulate between the air storage cylinder and the hydraulic oil tank, and the hydraulic oil tank does not directly exchange gas with the outside world, thereby minimizing the possibility of external air contaminating the hydraulic system.

[0065] An embodiment of the fourth aspect of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the air pressure balance control method in the above embodiment are implemented.

[0066] An embodiment of the fifth aspect of the present invention provides a chip, which includes a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the steps of the air pressure balance control method in the above embodiment.

[0067] Additional aspects and advantages of embodiments of the present invention will become apparent in the following description or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 A schematic diagram of an air pressure balancing system according to an embodiment of the present invention is shown;

[0069] Figure 2 A schematic diagram of a hydraulic oil tank according to an embodiment of the present invention is shown;

[0070] Figure 3 A schematic diagram of an engineering machine according to an embodiment of the present invention is shown;

[0071] Figure 4 A flow chart of a gas pressure balance control method according to an embodiment of the present invention is shown.

[0072] in, Figures 1 to 3 The corresponding relationship between the reference numerals and the component names is as follows:

[0073] 100: air pressure balance system; 110: hydraulic oil tank; 111: exhalation port; 112: inlet port; 113: pressure measuring port; 114: oil filling port; 115: exhaust port; 116: oil window; 117: oil suction port; 118: oil return port; 121: first sensor; 122: oil removal filter; 123: air filter; 124: air compressor; 125: oil-water separator; 126: one-way valve; 130: air reservoir; 140: solenoid reversing valve; 151: second sensor; 152: proportional throttle valve; 153: air dryer; 154: safety valve; 155: drain valve; 161: first air path; 162: second air path; 163: third air path; 164: fourth air path; 170: controller; 200: construction machinery; 210: frame. DETAILED DESCRIPTION

[0074] In order to more clearly understand the above-mentioned purposes, features and advantages of the embodiments of the present invention, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0075] In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the embodiments of the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present application is not limited to the specific embodiments disclosed below.

[0076] Refer to the following Figures 1 to 4 The following describes an air pressure balance system 100 , an engineering machine 200 , an air pressure balance control method, a computer-readable storage medium, and a chip provided according to some embodiments of the present invention.

[0077] Embodiment 1

[0078] like Figure 1 and Figure 2 As shown, an air pressure balance system 100 provided by an embodiment of the present invention includes a hydraulic oil tank 110, a first sensor 121, an air reservoir 130, an electromagnetic reversing valve 140, a second sensor 151, a proportional throttle valve 152 and a controller 170. The hydraulic oil tank 110 is used to store hydraulic medium, and the hydraulic medium can be a medium such as hydraulic oil. Optionally, the hydraulic oil tank 110 has an oil suction port 117 and an oil return port 118, and the hydraulic medium flows from the oil suction port 117 to the hydraulic system, and the hydraulic medium can flow back to the hydraulic oil tank 110 from the oil return port 118. Further, the hydraulic oil tank 110 has an exhalation port 111, an air suction port 112 and a pressure measuring port 113. Optionally, the exhalation port 111, the air suction port 112 and the pressure measuring port 113 are all located at the top of the hydraulic oil tank 110. The exhalation port 111 is connected to the gas in the hydraulic oil tank 110, and the air suction port 112 is connected to the gas in the hydraulic oil tank 110. Further, the first sensor 121 is provided at the pressure measuring port 113. The first sensor 121 is used to monitor the air pressure in the hydraulic oil tank 110. The air cylinder 130 is used to store gas. Further, the electromagnetic reversing valve 140 has a first interface, a second interface and a third interface. The first interface of the electromagnetic reversing valve 140 is used to communicate with the outside world, the second interface of the electromagnetic reversing valve 140 is used to communicate with the exhalation port 111 of the hydraulic oil tank 110, and the third interface of the electromagnetic reversing valve 140 is used to connect with the air cylinder 130. The third interface is selectively connected with the first interface or the second interface. When the third interface is connected with the first interface, the electromagnetic reversing valve 140 is in the first position, and the electromagnetic reversing valve 140 is connected with the outside world; when the third interface is connected with the second interface, the electromagnetic reversing valve 140 is in the second position, and the electromagnetic reversing valve 140 is connected with the exhalation port 111.

[0079] Further, the second sensor 151 is provided in the air reservoir 130. The second sensor 151 is used to monitor the air pressure in the air reservoir 130. The proportional throttle valve 152 is connected to the air reservoir 130, and the proportional throttle valve 152 is connected to the air intake port 112 of the hydraulic oil tank 110. Further, the controller 170 is connected to the first sensor 121 to determine the first air pressure of the hydraulic oil tank 110. The controller 170 can obtain the first air pressure information about the hydraulic oil tank 110 from the first sensor 121, and the controller 170 determines the first air pressure of the hydraulic oil tank 110 according to the first air pressure information. Further, the controller 170 is connected to the second sensor 151 to determine the second air pressure of the air reservoir 130. The controller 170 can obtain the second air pressure information about the air reservoir 130 from the second sensor 151, and the controller 170 determines the second air pressure of the air reservoir 130 according to the second air pressure information. Further, the controller 170 can control the opening and closing of the electromagnetic reversing valve 140 or the proportional throttle valve 152 according to the first air pressure and the second air pressure. Specifically, it is determined whether the second air pressure is within a preset interval, and a first judgment result is generated, the left end point of the preset interval is the second threshold value, and the right end point of the preset interval is the third threshold value. In other words, it is determined whether the second air pressure is not less than the second threshold value and not greater than the third threshold value, and a first judgment result is generated. If the first judgment result is yes, the electromagnetic reversing valve 140 is controlled to be in the second position, at which time the third interface is connected to the first interface, and the electromagnetic reversing valve 140 is connected to the exhalation port 111; if the first judgment result is no, the electromagnetic reversing valve 140 is controlled to be in the first position, the third interface is connected to the first interface, the electromagnetic reversing valve 140 is connected to the outside, and the outside gas enters the gas storage cylinder 130 until the first judgment result is yes. It is worth noting that the air reservoir 130 is connected to the safety valve 154. When the pressure in the air reservoir 130 exceeds the third threshold, the safety valve 154 is connected to the outside world to keep the second air pressure within the preset range. Therefore, the air pressure (second air pressure) in the air reservoir 130 generally does not exceed the third threshold. Further, it is determined whether the absolute value of the difference between the first air pressure and the initial air pressure of the hydraulic oil tank 110 is greater than the first threshold, and a second judgment result is generated. If the second judgment result is yes, it is further determined whether the air pressure difference is a negative value, and a third judgment result is generated; if the second judgment result is no, the first air pressure and the air pressure difference are continuously obtained. If the third judgment result is yes, it means that the air pressure (first air pressure) in the hydraulic oil tank 110 is a negative pressure and the air pressure change value is greater than the first threshold, and the controller 170 controls the proportional throttle valve 152 to open, so that the compressed air in the air reservoir 130 enters the hydraulic oil tank 110 until the absolute value of the air pressure difference is not greater than the first threshold.If the third judgment result is no, it means that the air pressure in the hydraulic oil tank 110 is positive pressure and the air pressure change value is greater than the first threshold value. The controller 170 controls the air compressor 124 to extract the gas in the hydraulic oil tank 110 until the absolute value of the air pressure difference is not greater than the first threshold value. Finally, it is judged again whether the second air pressure is less than the second threshold value to generate the sixth judgment result. If the sixth judgment result is yes, the electromagnetic reversing valve 140 is controlled to be in the first position, the third interface is connected to the first interface, the electromagnetic reversing valve 140 is connected to the outside world, and the controller 170 controls the air compressor 124 to extract gas from the outside atmosphere; if the sixth judgment result is no, the air pressure is balanced.

[0080] By operating the controller 170 to control the opening and closing of the electromagnetic reversing valve 140 or the proportional throttle valve 152, air pressure balance is achieved, the absolute value of the difference between the first air pressure and the initial air pressure of the hydraulic oil tank 110 is not greater than the first threshold, and the second air pressure is within a preset range.

[0081] In the technical solution defined in the present invention, on the first hand, air can circulate between the air storage cylinder 130 and the hydraulic oil tank 110, and the hydraulic oil tank 110 does not directly exchange gas with the outside world, thereby minimizing the possibility of external air polluting the hydraulic system; on the second hand, the hydraulic oil tank 110, the air storage cylinder 130 and other components can be arranged separately, which is conducive to rational layout in a small space and convenient installation; on the third hand, the relative pressure of the air in the hydraulic oil tank 110 is very small, almost zero, and the pressure load applied to the inner wall of the hydraulic oil tank 110 can be ignored, which is conducive to extending the service life of the hydraulic oil tank 110; on the fourth hand, there is no air back pressure in the hydraulic oil tank 110, and the return oil pipeline of the pump and the valve group is smooth, which is conducive to the stable operation of the system; on the fifth hand, the air pressure balance system 100 can be applied to engineering machinery 200 with very harsh working conditions, and has wider versatility.

[0082] Embodiment 2

[0083] The first interface is connected to the outside world through the first gas circuit 161, and the second interface is connected to the exhalation port 111 through the second gas circuit 162. When the third interface is connected to the first interface, the electromagnetic reversing valve 140 is in the first position, and the electromagnetic reversing valve 140 is connected to the outside world; when the third interface is connected to the second interface, the electromagnetic reversing valve 140 is in the second position, and the electromagnetic reversing valve 140 is connected to the exhalation port 111. The first interface of the electromagnetic reversing valve 140 is used to communicate with the outside world, the second interface of the electromagnetic reversing valve 140 is used to communicate with the exhalation port 111 of the hydraulic oil tank 110, and the third interface of the electromagnetic reversing valve 140 is used to connect with the air reservoir 130. The third interface is selectively connected to the first interface or the second interface, so that the air reservoir 130 can selectively communicate with the hydraulic oil tank 110 or the outside atmosphere through the electromagnetic reversing valve 140 to achieve the purpose of dynamic adjustment and control.

[0084] Furthermore, if Figure 1 As shown, the air pressure balance system 100 also includes an oil removal filter 122. Specifically, the oil removal filter 122 is arranged in the second air path 162. When the third interface is connected to the second interface, the electromagnetic reversing valve 140 is in the second position, and the electromagnetic reversing valve 140 is connected to the exhalation port 111. The air compressor 124 extracts the gas in the hydraulic oil tank 110 for compression, and then delivers the compressed gas to the air storage cylinder 130. When the air compressor 124 extracts the gas in the hydraulic oil tank 110, some oil mist or water droplets will be attached, and the oil removal filter 122 can filter out this part of the oil mist or water droplets. Specifically, the oil removal filter 122 is mainly composed of a cyclone separation section, an inertial demister pre-filter box, a fine filter element, a drain valve, a pressure and temperature gauge, and the air carrying oil and water enters the oil removal filter 122 in a tangential direction from the air inlet pipe. The mixture is separated by the cyclone of the oil removal filter 122, and part of the hydraulic oil and water are separated. After that, the gas and liquid are further separated under the action of inertial collision. After passing through the pre-filter box, the dust with larger particle size in the gas is filtered out, which plays a role in protecting the subsequent fine filter element. The gas passes through the fine filter element, and solid particles with a particle size greater than 1 micron are filtered out; the oil mist and water mist with tiny particle size are collected on the fine filter element and condensed into larger droplets, which settle to the bottom of the fine filter tube under the action of gravity. The separated oil and water are discharged from each sewage outlet, and the gas is output from the gas outlet at the top.

[0085] Further, the air pressure balance system 100 also includes an air filter 123. Specifically, the air filter 123 is arranged in the first air path 161. When the third interface is connected to the first interface, the electromagnetic reversing valve 140 is in the first position, and the electromagnetic reversing valve 140 is connected to the outside. The air compressor 124 extracts external gas for compression and then delivers the compressed gas to the air storage cylinder 130. The air filter 123 is used to filter impurities in the air to avoid contaminating the hydraulic system.

[0086] Embodiment 3

[0087] like Figure 1As shown, the air pressure balance system 100 further includes an air compressor 124. Specifically, the air compressor 124 is connected to the third interface of the electromagnetic reversing valve 140, and the air compressor 124 is connected to the air reservoir 130. When the electromagnetic reversing valve 140 is in the first position, the electromagnetic reversing valve 140 is connected to the outside world, and the air compressor 124 extracts the outside atmosphere and compresses it, and then delivers the compressed gas to the air reservoir 130. When the electromagnetic reversing valve 140 is in the second position, the electromagnetic reversing valve 140 is connected to the exhalation port 111, and the air compressor 124 extracts the gas in the hydraulic oil tank 110 and compresses it, and then delivers the compressed gas to the air reservoir 130. By setting up the air compressor 124, the air can be compressed. The air is in a compressed state in the air cylinder 130, which can reduce the volume of the air cylinder 130 and the volume of the hydraulic oil tank 110. The hydraulic oil tank 110, the air cylinder 130 and other components can be arranged separately, which is conducive to rational layout in a small space and convenient installation.

[0088] Furthermore, the air pressure balance system 100 further includes an oil-water separator 125. Specifically, the oil-water separator 125 is connected to the air compressor 124, and the oil-water separator 125 is connected to the air storage cylinder 130. After the air compressor 124 compresses the gas, the compressed gas needs to pass through the oil-water separator 125 in the process of being transported to the air storage cylinder 130. The oil-water separator 125 is used to separate the oil and water entrained in the gas, ensure the purity of the gas, and reduce the possibility of impurities entering the hydraulic oil tank 110 with the gas and contaminating the hydraulic system.

[0089] Further, the air pressure balance system 100 further includes a one-way valve 126. Specifically, the one-way valve 126 is connected to the air compressor 124. Optionally, the oil-water separator 125 is disposed between the one-way valve 126 and the air compressor 124, that is, the oil-water separator 125 is connected to the air compressor 124, and the oil-water separator 125 is connected to the one-way valve 126. Further, the one-way valve 126 is connected to the air storage cylinder 130 through the fourth air path 164, and the gas can flow from the air compressor 124 to the air storage cylinder 130 through the one-way valve 126. By providing the one-way valve 126, the gas in the air storage cylinder 130 can be prevented from flowing back to the air compressor 124, and the resistance encountered by the air compressor 124 in the process of delivering the gas to the air storage cylinder 130 can also be reduced.

[0090] Further, the air pressure balance system 100 further includes a safety valve 154. Specifically, the safety valve 154 is connected to the fourth air path 164, and the safety valve 154 is in communication with the outside. The air reservoir 130 is connected to the safety valve 154. When the pressure in the air reservoir 130 exceeds the third threshold, the safety valve 154 is in communication with the outside to keep the second air pressure within a preset range. Therefore, the air pressure (second air pressure) in the air reservoir 130 generally does not exceed the third threshold.

[0091] Further, the air pressure balance system 100 further includes a drain valve 155. Specifically, the drain valve 155 is disposed on the air storage cylinder 130. Optionally, the drain valve 155 is located at the bottom of the air storage cylinder 130. The drain valve 155 can discharge condensed water at the bottom of the air storage cylinder 130 periodically.

[0092] Embodiment 4

[0093] like Figure 1 As shown, the air pressure balance system 100 also includes an air dryer 153. Specifically, the proportional throttle valve 152 is connected to the air reservoir 130 through the third air path 163. The air dryer 153 is arranged in the third air path 163. The air pressure (first air pressure) in the hydraulic oil tank 110 is a negative pressure and the air pressure change value is greater than the first threshold value. The controller 170 controls the proportional throttle valve 152 to open so that the compressed air in the air reservoir 130 enters the hydraulic oil tank 110 until the absolute value of the air pressure difference is not greater than the first threshold value. The air dryer 153 is used to remove impurities such as water mist in the gas to reduce the possibility of polluting the hydraulic system.

[0094] Embodiment 5

[0095] like Figure 2 As shown, the hydraulic oil tank 110 also has an oil filling port 114 and an exhaust port 115. The oil filling port 114 is arranged at the top of the hydraulic oil tank 110, and the exhaust port 115 is arranged at one side of the hydraulic oil tank 110. When the hydraulic oil tank 110 is used for the first time, the exhaust port 115 is opened, hydraulic oil is added from the oil filling port 114, and the liquid level is observed through the oil window 116. When the liquid level reaches the required height, the exhaust port 115 and the oil filling port 114 are closed.

[0096] In another embodiment, the hydraulic oil tank 110 further has an oil window 116, and the oil window 116 is disposed on one side of the hydraulic oil tank 110. By providing the oil window 116, the staff can observe the liquid level through the oil window 116.

[0097] In another embodiment, the hydraulic oil tank 110 has an oil suction port 117 and an oil return port 118, and the working medium in the hydraulic oil tank 110 can flow to the hydraulic system through the oil suction port 117, and the hydraulic medium can flow back to the inside of the hydraulic oil tank 110 through the oil return port 118. By arranging the oil suction port 117 and the oil return port 118 on opposite sides of the hydraulic oil tank 110, on the one hand, it is conducive to a reasonable spatial layout to avoid interference between the oil suction pipeline and the oil return pipeline; on the other hand, the oil suction port 117 and the oil return port 118 are far away from each other, which is used to prevent or reduce the impact of bubbles caused by splashing on the oil pump and the oil circuit; furthermore, the temperature of the working medium can be reduced to a certain extent.

[0098] Embodiment 6

[0099] like Figure 3 As shown, an engineering machine 200 provided by one embodiment of the present invention includes a frame 210 and a gas pressure balance system 100 in any of the above embodiments. The hydraulic oil tank 110, the air reservoir 130 and the controller 170 of the gas pressure balance system 100 are all connected to the frame 210. The gas pressure balance system 100 in the present invention can be applied to engineering machines 200 with extremely harsh working conditions, such as mining equipment, etc., and has wider versatility.

[0100] Embodiment 7

[0101] like Figure 4 As shown, an air pressure balance control method provided by an embodiment of the present invention is used in a controller of an air pressure balance system in any of the above embodiments. The specific steps of the air pressure balance control method include:

[0102] S402, obtaining first air pressure information about a hydraulic oil tank of the air pressure balance system from a first sensor of the air pressure balance system, and obtaining second air pressure information about an air reservoir of the air pressure balance system from a second sensor of the air pressure balance system. The controller obtains pressure information from the sensor and analyzes the pressure information;

[0103] S404, determining the first air pressure of the hydraulic oil tank according to the first air pressure information, and determining the second air pressure of the air reservoir according to the second air pressure information. The controller can determine the real-time air pressure in the hydraulic oil tank or the air reservoir according to the acquired pressure information;

[0104] S406, determine whether the second air pressure is within a preset interval, generate a first judgment result, the left end point of the preset interval is the second threshold, and the right end point of the preset interval is the third threshold. Determine whether the air pressure (second air pressure) in the air reservoir is not less than the second threshold and not greater than the third threshold. Set the maximum air pressure in the air reservoir to a fixed value P max , the minimum air pressure is a fixed value P min , the second air pressure is P2. This step is used to determine P min ≤P2≤P max ;

[0105] S408, if the first judgment result is yes, the electromagnetic reversing valve of the air pressure balance system is controlled to be in the second position. If the air pressure in the air reservoir (the second air pressure) is not less than the second threshold value and not greater than the third threshold value, the controller controls the electromagnetic reversing valve to be in the second position, at which time the third interface is connected to the first interface, and the electromagnetic reversing valve is connected to the exhalation port;

[0106] S410, if the first judgment result is no, then the electromagnetic reversing valve of the air pressure balance system is controlled to be in the first position, and the air compressor of the air pressure balance system is controlled to extract gas from the outside atmosphere until the first judgment result is yes. If the second air pressure is not within the preset interval, it can be understood that the air pressure in the air cylinder is lower than the second threshold at this time, then the controller controls the electromagnetic reversing valve to be in the first position, the third interface is connected to the first interface, the electromagnetic reversing valve is connected to the outside world, and the outside gas enters the air cylinder until the first judgment result is yes. It is worth noting that the air cylinder is connected to the safety valve. When the pressure in the air cylinder exceeds the third threshold, the safety valve is connected to the outside world to keep the second air pressure within the preset interval. Therefore, the air pressure in the air cylinder (the second air pressure) generally does not exceed the third threshold;

[0107] S412, subtracting the initial air pressure of the hydraulic oil tank from the first air pressure to obtain an air pressure difference;

[0108] S414, determine whether the absolute value of the air pressure difference is greater than the first threshold value, and generate a second judgment result. Determine whether the absolute value of the difference between the first air pressure and the initial air pressure is greater than a preset value. The first air pressure is P1, and P1 is a positive or negative value. Set the minimum starting pressure difference of the controller to △P, and △P is a positive value. The control target of the controller is -△P≤P1≤+△P(|P1|≤△P);

[0109] S416, if the second judgment result is yes, then further judge whether the air pressure difference is a negative value, and generate a third judgment result. If the absolute value of the air pressure difference is greater than the first threshold value, the controller needs to adjust the air pressure in the hydraulic oil tank, and further judge whether the first air pressure is positive or negative of P1; if the second judgment result is no, then return to subtract the initial air pressure of the hydraulic oil tank from the first air pressure to obtain the air pressure difference (return to step S412). If the absolute value of the air pressure difference is not greater than the first threshold value, the controller does not need to adjust the air pressure in the hydraulic oil tank. At this time, the controller continues to obtain the first air pressure and the air pressure difference;

[0110] S418, if the third judgment result is yes, then open the proportional throttle valve of the air pressure balance system to allow the compressed air in the air reservoir to enter the hydraulic oil tank. If the air pressure in the hydraulic oil tank (the first air pressure) is negative pressure and the air pressure change value is greater than the first threshold, the controller controls the proportional throttle valve to open to allow the compressed air in the air reservoir to enter the hydraulic oil tank until the absolute value of the air pressure difference is no greater than the first threshold;

[0111] S420, determining whether the absolute value of the air pressure difference is not greater than the first threshold value, and generating a fourth determination result. Based on the fourth determination result, the controller determines whether to continue to open the proportional throttle valve;

[0112] S422, if the fourth judgment result is yes, then close the proportional throttle valve. If the air pressure (first air pressure) in the hydraulic oil tank is a negative pressure and the air pressure change value is not greater than the first threshold, the controller does not need to adjust the air pressure in the hydraulic oil tank, and closes the proportional throttle valve at this time; if the fourth judgment result is no, return to open the proportional throttle valve of the air pressure balance system (return to step S418). If the air pressure (first air pressure) in the hydraulic oil tank is a negative pressure and the air pressure change value is greater than the first threshold, the controller controls the proportional throttle valve to open, so that the compressed air in the air cylinder enters the hydraulic oil tank until the absolute value of the air pressure difference is not greater than the first threshold;

[0113] S424, if the third judgment result is no, then control the air compressor to extract the gas in the hydraulic oil tank. If the air pressure in the hydraulic oil tank is positive pressure and the air pressure change value is greater than the first threshold, the controller controls the air compressor to extract the gas in the hydraulic oil tank until the absolute value of the air pressure difference is not greater than the first threshold;

[0114] S426, determining whether the absolute value of the air pressure difference is not greater than the first threshold value, and generating a fifth determination result. Based on the fifth determination result, the controller determines whether to continue to turn on the air compressor;

[0115] S428, if the fifth judgment result is yes, then turn off the air compressor. If the change value of the air pressure in the hydraulic oil tank is not greater than the first threshold value, the controller does not need to adjust the air pressure in the hydraulic oil tank, and the controller turns off the air compressor at this time; if the fifth judgment result is no, then return to control the air compressor to extract the gas in the hydraulic oil tank (return to step S424). If the change value of the air pressure in the hydraulic oil tank is greater than the first threshold value, the controller needs to adjust the air pressure in the hydraulic oil tank, and the controller controls the air compressor to continue to turn on;

[0116] S430, determining whether the second air pressure is less than the second threshold value, and generating a sixth determination result. After the controller controls the proportional throttle valve to open, the compressed air in the air reservoir enters the hydraulic oil tank, and the air pressure in the air reservoir will decrease. To prevent the second air pressure from being too low, a sixth determination result is generated;

[0117] S432, if the sixth judgment result is no, the air pressure is balanced. At this time, the absolute value of the difference between the first air pressure and the initial air pressure of the hydraulic oil tank is not greater than the first threshold, and the second air pressure is within the preset range, indicating that it is in an air pressure balance state; if the sixth judgment result is yes, then the electromagnetic reversing valve of the air pressure balance system is returned to be in the first position, and the air compressor of the air pressure balance system is controlled to extract gas from the outside atmosphere (return to step S410). If the air pressure in the air storage cylinder is lower than the second threshold, the controller controls the electromagnetic reversing valve to be in the first position, the third interface is connected to the first interface, the electromagnetic reversing valve is connected to the outside, and the outside gas enters the air storage cylinder until the sixth judgment result is no.

[0118] In the technical solution defined in the present invention, air can circulate between the air storage cylinder and the hydraulic oil tank, and the hydraulic oil tank does not directly exchange gas with the outside world, thereby minimizing the possibility of external air contaminating the hydraulic system.

[0119] Embodiment 8

[0120] An embodiment of the present invention provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps of the air pressure balance control method in the above embodiment are implemented.

[0121] Embodiment 9

[0122] An embodiment of the present invention provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the steps of the air pressure balance control method in the above embodiment.

[0123] Embodiment 10

[0124] like Figure 1 As shown, the air pressure balance system 100 is composed of a hydraulic oil tank 110, an oil removal filter 122, an air filter 123, an electromagnetic reversing valve 140, an air compressor 124, an oil-water separator 125, a one-way valve 126, a safety valve 154, an air pressure sensor (a second sensor 151), an air storage cylinder 130, a drain valve 155, a controller 170, an air dryer 153, a proportional throttle valve, and a micro-pressure sensor (a first sensor 121). Figure 2 As shown, the hydraulic oil tank 110 includes an oil return port 118 , an exhaust port 115 , an oil filling port 114 , an exhalation port 111 , an intake port 112 , a pressure measuring port 113 , an oil window 116 and an oil suction port 117 .

[0125] The first port of the oil removal filter 122 is connected to the exhalation port 111 of the hydraulic oil tank 110 through a pipeline. The second port of the oil removal filter 122 is connected to the first port of the electromagnetic reversing valve 140 through a pipeline. The first port of the air filter 123 is connected to the atmosphere. The second port of the air filter 123 is connected to the second port of the electromagnetic reversing valve 140 through a pipeline. The third port of the electromagnetic reversing valve 140 is connected to the first port of the air compressor 124 through a pipeline. The second port of the compressor is connected to the first port of the oil-water separator 125 through a pipeline. The second port of the oil-water separator 125 is connected to the first port of the check valve 126 through a pipeline. The second port of the check valve 126 is connected to the first port of the air reservoir 130 through a pipeline. The first port of the safety valve 154 is connected to the atmosphere, and the second port of the safety valve 154 is connected to the pipeline between the second port of the check valve 126 and the first port of the air reservoir 130 through a pipeline. The air pressure sensor is installed on the air reservoir 130. The drain valve 155 is installed on the air storage cylinder 130, and the second port of the air storage cylinder 130 is connected to the first port of the air dryer 153 through a pipeline. The second port of the air dryer 153 is connected to the first port of the proportional throttle valve through a pipeline, and the second port of the proportional throttle valve is connected to the air intake port 112 of the hydraulic oil tank 110 through a pipeline. The micro-pressure sensor is installed on the pressure measuring port 113 of the hydraulic oil tank 110, and the controller 170 is connected to the electromagnetic reversing valve 140, the air compressor 124, the air pressure sensor, the proportional throttle valve, and the micro-pressure sensor through the control circuit.

[0126] When the hydraulic oil tank 110 is used for the first time, the exhaust port 115 is opened, hydraulic oil is added from the oil filling port 114, and the liquid level is observed through the oil window 116. When the liquid level reaches the required height, the exhaust port 115 and the oil filling port 114 are closed.

[0127] The oil removal filter 122 removes the oil mist in the air flowing out of the hydraulic oil tank 110 from the exhalation port 111 .

[0128] The air filter 123 removes solid particles and water vapor in the air. min (second threshold), the air compressor 124 draws air from the external environment through the air filter 123 and replenishes it into the air storage cylinder 130.

[0129] The solenoid reversing valve 140 is controlled by the controller 170. When the control signal of the controller 170 is not received, the solenoid reversing valve 140 works in the right position (the second position), so that the second port of the oil removal filter 122 is connected to the first port of the air compressor 124, and the air compressor 124 draws air from the upper part of the hydraulic oil tank 110; when the control signal of the controller 170 is received, the solenoid reversing valve 140 works in the left position (the first position), so that the second port of the air filter 123 is connected to the first port of the air compressor 124, and the air compressor 124 draws air from the external environment.

[0130] The air compressor 124 is controlled by a controller 170 to control the start and stop and the rotation speed of the air compressor 124. When the rotation speed of the air compressor 124 increases, the air intake volume increases, and when the rotation speed decreases, the air intake volume decreases.

[0131] The oil-water separator 125 filters out condensed water and oil mist in the air output by the air compressor 124 .

[0132] The one-way valve 126 allows air to flow into the air reservoir 130 in one direction.

[0133] When the internal pressure of the air storage cylinder 130 exceeds a set value, the safety valve 154 will automatically open and discharge excess air, thus providing a safety protection function.

[0134] The air pressure sensor measures the pressure of the air inside the air storage cylinder 130 in real time and feeds it back to the controller 170 .

[0135] The air cylinder 130 stores compressed air. The air for breathing in the hydraulic oil tank 110 circulates between the air cylinder 130 and the hydraulic oil tank 110 without exchanging with the outside air, thus minimizing the pollution caused by the outside air; the air is in a compressed state in the air cylinder 130, thus reducing the volume occupied by the air for breathing.

[0136] The drain valve 155 can periodically drain the condensed water at the bottom of the gas storage cylinder 130 .

[0137] The air dryer 153 removes moisture from the compressed air output from the air storage cylinder 130 .

[0138] The proportional throttle valve is controlled by the controller 170, which controls the opening size of the valve core of the proportional throttle valve, thereby controlling the size of the compressed air flow rate. When the proportional throttle valve works in the left position, the valve core is completely closed, and when it works in the right position, the valve core is completely open.

[0139] The micro-pressure sensor measures the pressure of the air above the hydraulic oil tank 110 in real time and feeds it back to the controller 170. The micro-pressure sensor can detect positive pressure and negative pressure.

[0140] The controller 170 sets the maximum air pressure in the air reservoir 130 to a fixed value Pmax , the minimum air pressure is a fixed value P min The pressure value fed back by the air pressure sensor in real time is P2; the pressure change difference of the air above the hydraulic oil tank 110 detected by the micro-pressure sensor is set to P1, and P1 is a positive value or a negative value. The minimum starting pressure difference of the controller 170 is set to △P (first threshold value), and △P is a positive value. The control target of the controller 170 is -△P≤P1≤+△P.

[0141] According to the embodiments of the air pressure balance system, engineering machinery, air pressure balance control method, computer-readable storage medium and chip of the present invention, on the first aspect, air can circulate between the air reservoir and the hydraulic oil tank, and the hydraulic oil tank does not directly exchange gas with the outside world, thereby minimizing the possibility of external air contaminating the hydraulic system; on the second aspect, the hydraulic oil tank, air reservoir and other components can be arranged separately, which is conducive to rational layout in a small space and convenient installation; on the third aspect, the relative pressure of the air in the hydraulic oil tank is very small, almost zero, and the pressure load applied to the inner wall of the hydraulic oil tank can be ignored, which is conducive to extending the service life of the hydraulic oil tank; on the fourth aspect, there is no air back pressure in the hydraulic oil tank, and the return oil pipeline of the pump and valve group is smooth, which is conducive to the stable operation of the system; on the fifth aspect, the air pressure balance system can be applied to engineering machinery with very harsh working conditions and has wider versatility.

[0142] In the present invention, the terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance; the term "plurality" refers to two or more, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0143] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “front” and “back” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention.

[0144] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0145] The above 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 variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An air pressure balance system, characterized in that: include: A hydraulic oil tank (110) for storing hydraulic medium, wherein the hydraulic oil tank (110) has an exhalation port (111), an inhalation port (112) and a pressure measuring port (113); A first sensor (121), disposed at the pressure measuring port (113), the first sensor (121) being used to monitor the air pressure in the hydraulic oil tank (110); A gas storage cylinder (130) for storing gas; an electromagnetic reversing valve (140), the electromagnetic reversing valve (140) having a first interface, a second interface and a third interface, the first interface being in communication with the outside, the second interface being in communication with the exhalation port (111), and the third interface being connected with the air storage cylinder (130); A second sensor (151) is provided in the air storage cylinder (130), and the second sensor (151) is used to monitor the air pressure in the air storage cylinder (130); A proportional throttle valve (152) connected to the air storage cylinder (130), the proportional throttle valve (152) being connected to the air intake port (112); A controller (170) is connected to the first sensor (121) to determine the first air pressure of the hydraulic oil tank (110), the controller (170) is connected to the second sensor (151) to determine the second air pressure of the air storage cylinder (130), the controller (170) is connected to the electromagnetic reversing valve (140), and the controller (170) is connected to the proportional throttle valve (152). The controller (170) can control the opening and closing of the electromagnetic reversing valve (140) or the proportional throttle valve (152) according to the first air pressure and the second air pressure, so that the absolute value of the difference between the first air pressure and the initial air pressure of the hydraulic oil tank (110) is not greater than a first threshold value, and the second air pressure is within a preset range.

2. The air pressure balance system according to claim 1, characterized in that: The first interface is connected to the outside world via a first air path (161), and the second interface is connected to the exhalation port (111) via a second air path (162). When the third interface is connected to the first interface, the electromagnetic reversing valve (140) is in a first position, and the electromagnetic reversing valve (140) is connected to the outside world; when the third interface is connected to the second interface, the electromagnetic reversing valve (140) is in a second position, and the electromagnetic reversing valve (140) is connected to the exhalation port (111).

3. The air pressure balance system according to claim 1, characterized in that: Also includes: An air compressor (124) is connected to the third interface, and the air compressor (124) is connected to the air storage cylinder (130).

4. The air pressure balance system according to claim 2, characterized in that: Also includes: An oil removal filter (122) is provided in the second gas path (162).

5. The air pressure balance system according to claim 2, characterized in that: Also includes: An air filter (123) is provided in the first air path (161).

6. The air pressure balancing system according to any one of claims 1 to 5, characterized in that: The proportional throttle valve (152) is connected to the air storage cylinder (130) via a third air path (163), and the air pressure balance system further comprises: The air dryer (153) is provided in the third air path (163).

7. The air pressure balance system according to claim 3, characterized in that: Also includes: The oil-water separator (125) is connected to the air compressor (124), and the oil-water separator (125) is connected to the air storage cylinder (130).

8. The air pressure balance system according to claim 3, characterized in that: Also includes: A one-way valve (126) is connected to the air compressor (124). The one-way valve (126) is connected to the air storage cylinder (130) via a fourth air path (164). Gas can flow from the air compressor (124) to the air storage cylinder (130) via the one-way valve (126).

9. The air pressure balance system according to claim 8, characterized in that: Also includes: The safety valve (154) is connected to the fourth gas path (164), and the safety valve (154) is in communication with the outside world.

10. The air pressure balancing system according to any one of claims 1 to 5, characterized in that: Also includes: A drain valve (155) is provided on the gas storage cylinder (130).

11. The air pressure balancing system according to any one of claims 1 to 5, characterized in that: The hydraulic oil tank (110) further comprises an oil filling port (114) and an exhaust port (115); the oil filling port (114) is arranged at the top of the hydraulic oil tank (110), and the exhaust port (115) is arranged at one side of the hydraulic oil tank (110).

12. The air pressure balancing system according to any one of claims 1 to 5, characterized in that: The hydraulic oil tank (110) further comprises an oil window (116), and the oil window (116) is arranged on one side of the hydraulic oil tank (110); or the hydraulic oil tank (110) further comprises an oil suction port (117) and an oil return port (118), and the oil suction port (117) is arranged on one side of the hydraulic oil tank (110), and the oil return port (118) is arranged on the other side of the hydraulic oil tank (110).

13. An engineering machine, characterized in that: include: A frame (210); According to any one of claims 1 to 12, the hydraulic oil tank (110), the air storage cylinder (130) and the controller (170) of the air pressure balancing system are all connected to the frame (210).

14. A method for controlling air pressure balance, characterized in that: A controller for a gas pressure balancing system according to any one of claims 1 to 12, comprising: Acquire first air pressure information about a hydraulic oil tank of the air pressure balance system from a first sensor of the air pressure balance system, and acquire second air pressure information about an air reservoir of the air pressure balance system from a second sensor of the air pressure balance system; Determine a first air pressure of the hydraulic oil tank according to the first air pressure information, and determine a second air pressure of the air reservoir according to the second air pressure information; Determine whether the second air pressure is within a preset interval, and generate a first determination result, wherein the left end point of the preset interval is a second threshold value, and the right end point of the preset interval is a third threshold value; If the first judgment result is yes, the electromagnetic reversing valve of the air pressure balance system is controlled to be in the second position; if the first judgment result is no, the electromagnetic reversing valve of the air pressure balance system is controlled to be in the first position, and the air compressor of the air pressure balance system is controlled to extract gas from the outside atmosphere until the first judgment result is yes; Subtracting the initial air pressure of the hydraulic oil tank from the first air pressure to obtain an air pressure difference; Determine whether the absolute value of the air pressure difference is greater than a first threshold value, and generate a second determination result; If the second judgment result is yes, further judging whether the air pressure difference is a negative value, and generating a third judgment result; if the second judgment result is no, returning to the step of subtracting the initial air pressure of the hydraulic oil tank from the first air pressure to obtain the air pressure difference; If the third judgment result is yes, opening the proportional throttle valve of the air pressure balance system to allow the compressed air in the air reservoir to enter the hydraulic oil tank; determining whether the absolute value of the air pressure difference is not greater than the first threshold, and generating a fourth determination result; If the fourth judgment result is yes, then close the proportional throttle valve; if the fourth judgment result is no, then return to opening the proportional throttle valve of the air pressure balance system; If the third judgment result is no, controlling the air compressor to extract gas from the hydraulic oil tank; determining whether the absolute value of the air pressure difference is not greater than the first threshold, and generating a fifth determination result; If the fifth judgment result is yes, then turn off the air compressor; if the fifth judgment result is no, then return to controlling the air compressor to extract the gas in the hydraulic oil tank; determining whether the second air pressure is less than a second threshold, and generating a sixth determination result; If the sixth judgment result is yes, the electromagnetic reversing valve controlling the air pressure balance system is returned to the first position, and the air compressor of the air pressure balance system is controlled to extract gas from the outside atmosphere; if the sixth judgment result is no, the air pressure is balanced.

15. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the air pressure balance control method according to claim 14 are implemented.

16. A chip, characterized in that: The chip includes a processor and a communication interface, the communication interface is coupled to the processor, and the processor is used to run a program or instruction to implement the steps of the air pressure balance control method as described in claim 14.

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