Hydraulic control system of heavy-load mechanical equipment

Abstract

The invention belongs to the field of mechanical equipment, and particularly relates to a hydraulic control system of heavy-load mechanical equipment. The hydraulic module is used for providing hydraulic power for heavy-load mechanical equipment; the hydraulic oil inlet pipeline is used for conveying hydraulic oil in the hydraulic oil tank to the hydraulic module; the hydraulic oil return pipeline is used for conveying the hydraulic oil in the hydraulic module back to the hydraulic oil tank; the air pressure balancing device is used for balancing air pressure inside and outside the hydraulic oil tank; and the oil foam eliminating device is used for eliminating oil foam in the hydraulic oil tank. The air bag is protected through the cover cap, the air bag has enough protection space in the cover cap, in addition, the inner supporting frame is further arranged to prevent blockage, and air in the oil tank can be simply and rapidly replaced with inert gas; by arranging the oil foam eliminating device, oil foam in the hydraulic oil tank can be effectively eliminated, the defoaming effect is good, and therefore the stability of hydraulic transmission of the hydraulic module can be effectively kept.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical equipment, and in particular to a hydraulic control system for heavy-duty mechanical equipment. Background Art

[0002] Heavy-duty mechanical equipment, referred to as heavy equipment, is generally controlled and driven by hydraulic equipment. Hydraulic equipment is a device that transmits energy through fluid.

[0003] At present, the hydraulic oil in the oil tank of most hydraulic equipment / systems is connected to the atmosphere of the external environment, because it is necessary to maintain the air pressure balance inside and outside the oil tank, thereby maintaining the stability and precise transmission of the hydraulic system.

[0004] However, the hydraulic system generates heat during operation, and the temperature difference between the inside and outside will cause the inner wall of the oil tank to be covered with condensed water, which will mix into the hydraulic oil, causing the water content in the hydraulic oil to exceed the standard, causing harm. The current conventional practice is to replace the hydraulic oil regularly and then remove the water; however, the disadvantage of this method is that the hydraulic oil needs to be replaced frequently and the cost is high.

[0005] To solve this problem, some designs have been proposed. The oil tank is made into a closed type and a buffer device is installed to balance the air pressure inside and outside the oil tank. For example, the "A hydraulic oil tank system for preventing condensation water" disclosed in the publication (announcement) number: CN112610546A includes a hydraulic oil tank and an air bag. The hydraulic oil tank is provided with an oil suction port, an oil return port and a refueling port, and the side wall or top wall of the oil tank above the highest liquid level of the hydraulic oil tank is connected to the air bag through a connecting pipe, and a switch valve is provided on the connecting pipe; the hydraulic oil tank is filled with hydraulic oil, and the remaining space inside the hydraulic oil tank and the inside of the air bag are filled with dry air or dry inert gas.

[0006] However, when the inventors conducted a reproduction study on the technology, they found that, firstly, if the volume of the hydraulic oil in the oil tank changes greatly, the air bag may block the exchange air holes. In addition, there is no mention of how to empty the gas in the oil tank and inflate it. Most importantly, because it is a closed environment, the hydraulic oil will flow back and forth at high speed, and the hydraulic oil will produce a large amount of foam (oil foam) in the oil tank. These foams are very difficult to defoam in a closed environment, especially during long-term continuous operation. A thick layer of oil foam will float on the surface of the hydraulic oil in the oil tank, and too much oil foam will be sucked into the hydraulic equipment, which may affect the stability of the hydraulic transmission and challenge the precise control of the hydraulic force. Therefore, how to quickly defoam the oil foam on the surface of the hydraulic oil in the oil tank has become a problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0007] The object of the present invention is to provide a hydraulic control system for heavy-duty mechanical equipment to solve the above-mentioned problems.

[0008] The purpose of the present invention is to provide a hydraulic control system for heavy-duty mechanical equipment, which can be achieved through the following technical solutions:

[0009] A hydraulic control system for heavy-duty mechanical equipment includes a hydraulic module for providing hydraulic power to the heavy-duty mechanical equipment, a hydraulic oil tank, a hydraulic oil inlet pipeline for conveying the hydraulic oil in the hydraulic oil tank to the hydraulic module, a hydraulic oil return pipeline for conveying the hydraulic oil in the hydraulic module back to the hydraulic oil tank, and also includes an air pressure balancing device for balancing the air pressure inside and outside the hydraulic oil tank, and an oil foam eliminating device for eliminating oil foam in the hydraulic oil tank.

[0010] Furthermore, a tank top is provided on the top of the hydraulic oil tank, and the air pressure balancing device includes a gas cylinder storing inert gas, a cover installed above the tank top, a first solenoid valve installed in the center of the tank top, a spherical airbag, an inner support frame located in the airbag, a second solenoid valve installed in the center of the top of the airbag, a third solenoid valve installed on the top of the cover, an upper vertical pipe for connecting the third solenoid valve with the second solenoid valve, and a lower vertical pipe located below the second solenoid valve, the lower end of the cover is sealed and connected to the tank top to form an activity chamber, and the first solenoid valve is installed in the center of the top of the airbag. A connecting rod is fixedly installed between the second solenoid valve and the inner wall of the cover, the upper end of the lower vertical pipe is connected with the lower end of the second solenoid valve, the lower end of the lower vertical pipe extends into the interior of the inner support frame, the lower end of the inner support frame is fixedly connected to the top of the box, a buffer space is surrounded between the airbag and the top of the box, the buffer space and the inner cavity of the hydraulic oil tank are connected or closed through the first solenoid valve, and the buffer space and the second solenoid valve are connected through the lower vertical pipe; a pressure reducing valve is arranged at the bottle mouth of the gas cylinder, and the pressure reducing valve is connected with the third solenoid valve.

[0011] Furthermore, an inner mounting ring is embedded in the center of the airbag, the inner mounting ring is connected to the airbag as a whole, a mounting hole adapted to the lower vertical tube is provided in the center of the inner mounting ring, the outer circumference of the airbag is integrally connected to an outer mounting ring, the outer mounting ring is sealingly connected to the box top, and the inner mounting ring is fixedly connected to the connecting rod.

[0012] Furthermore, the inner support frame includes at least four arc-shaped rods arranged in a central symmetrical manner, the upper ends of the arc-shaped rods are fixedly connected to the lower part of the lower vertical pipe, and the lower ends of the arc-shaped rods are fixedly connected to the box top.

[0013] Furthermore, a fourth solenoid valve connected to the inner cavity of the hydraulic oil tank is installed on the outer side of the hydraulic oil tank.

[0014] Furthermore, the oil foam elimination device includes megasonic probes arranged in an array, the megasonic probes include a probe body, a probe head, and a hollow spiral tube sleeved on the outside of the probe body, the hollow spiral tube is a cylindrical spiral structure, the tail end of the hollow spiral tube is welded to the head end of the probe body, the tail end of the probe body is sleeved with a hard rubber sleeve, the hard rubber sleeve is connected to the probe body as a whole, and the head end of the hollow spiral tube is fixedly connected to the hard rubber sleeve; the probe bodies of all megasonic probes are arranged inside the hydraulic oil tank, and the probe heads are located outside the hydraulic oil tank; the interior of the hollow spiral tube is filled with mercury, and the ratio of the volume of mercury in the hollow spiral tube to the volume of the hollow spiral tube is x, x=0.73.

[0015] Furthermore, the side wall of the hydraulic oil tank is provided with a through hole matching the hard rubber sleeve, the hard rubber sleeve is inserted into the through hole and sealed, and a flange is installed between the probe head and the hard rubber sleeve.

[0016] Furthermore, when the oil foam elimination device is started, the frequency of the megasonic waves emitted by the probe body is 8.6 MHz or 10.3 MHz, and the frequencies of the megasonic waves emitted by two adjacent probe bodies are not equal, so that the hydraulic oil inside the hydraulic oil tank is defoamed.

[0017] Furthermore, a pressure gauge for monitoring the internal air pressure of the hydraulic oil tank is installed on the outer wall of the hydraulic oil tank.

[0018] Furthermore, the inert gas is nitrogen or argon.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The hydraulic control system of the heavy-duty mechanical equipment described in the present invention protects the airbag by a cover. The airbag has sufficient protection space inside the cover. In addition, an internal support frame is provided to prevent blockage. The air in the oil tank can be simply and quickly replaced with an inert gas. The oil foam eliminating device is provided to effectively eliminate the oil foam in the hydraulic oil tank, and the defoaming effect is good, thereby effectively maintaining the stability of the hydraulic transmission of the hydraulic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a structural schematic diagram of a hydraulic control system for a heavy-duty mechanical equipment according to the present invention;

[0022] Figure 2 It is a connection diagram of the hydraulic oil tank and the air pressure balancing device of the present invention;

[0023] Figure 3 is a schematic diagram of the airbag of the present invention when viewed from above;

[0024] Figure 4It is a structural schematic diagram of the oil foam elimination device of the present invention;

[0025] Figure 5 This is a photo of the oil foam layer observed on the side wall of a simulated oil tank when the existing ultrasonic rod was tested at 200kHz;

[0026] Figure 6 It is a curve graph of x value and oil foam layer area. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0028] The following detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0029] In the description of the embodiments of the present application, it should be noted that if the terms "upper", "lower", "left", "right", "horizontal", "inner", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invented product is usually placed when used. It is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0030] In the description of the embodiments of the present application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0031] Example 1

[0032] like Figure 1 As shown, a hydraulic control system for heavy-duty mechanical equipment includes a hydraulic module 10 for providing hydraulic power to the heavy-duty mechanical equipment, a hydraulic oil tank 20, a hydraulic oil inlet pipeline 11 for conveying the hydraulic oil in the hydraulic oil tank 20 to the hydraulic module 10, and a hydraulic oil return pipeline 12 for conveying the hydraulic oil in the hydraulic module 10 back to the hydraulic oil tank 20.

[0033] The hydraulic control system of the heavy-duty mechanical equipment further includes an air pressure balancing device 30 for balancing the air pressure inside and outside the hydraulic oil tank 20 , and an oil foam eliminating device for eliminating oil foam in the hydraulic oil tank 20 .

[0034] like Figure 2 As shown, a tank top 21 is arranged on the top of the hydraulic oil tank 20, and the air pressure balance device 30 includes a gas cylinder storing an inert gas, a cover installed above the tank top 21, a first solenoid valve 39 installed in the center of the tank top 21, a spherical airbag 32, an inner support frame 33 located in the airbag 32, a second solenoid valve 36 installed in the center of the top of the airbag 32, a third solenoid valve 38 installed on the top of the cover, an upper vertical pipe 37 for connecting the third solenoid valve 38 with the second solenoid valve 36, and a lower vertical pipe 34 located below the second solenoid valve 36. The lower end of the cover is sealed and connected to the tank top 21 and encloses an activity chamber 31. A connecting rod 35 is fixedly installed between the second solenoid valve 36 and the inner wall of the cover, the upper end of the lower vertical pipe 34 is connected to the lower end of the second solenoid valve 36, the lower end of the lower vertical pipe 34 extends into the interior of the inner support frame 33, the lower end of the inner support frame 33 is fixedly connected to the box top 21, a buffer space is surrounded between the airbag 32 and the box top 21, the buffer space and the inner cavity of the hydraulic oil tank 20 are connected or closed through the first solenoid valve 39, and the buffer space and the second solenoid valve 36 are connected through the lower vertical pipe 34; a pressure reducing valve is provided at the bottle mouth of the gas cylinder, and the pressure reducing valve is connected to the third solenoid valve 38.

[0035] like Figure 3 As shown, to facilitate the installation of the airbag 32, an inner mounting ring 321 is embedded in the center of the airbag 32, and the inner mounting ring 321 is connected to the airbag 32 as a whole. A mounting hole 322 adapted to the lower vertical tube 34 is provided in the center of the inner mounting ring 321, and an outer mounting ring 333 is integrally connected to the outer circumference of the airbag 32, and the outer mounting ring 333 is sealed and connected to the box top 21, and the inner mounting ring 321 is fixedly connected to the connecting rod 35.

[0036] like Figure 4As shown, the oil foam elimination device includes megasonic probes 50 arranged in an array, the megasonic probes 50 include a probe body 51, a probe head 52, and a hollow spiral tube 53 sleeved on the outside of the probe body 51, the hollow spiral tube 53 is a cylindrical spiral structure, the tail end of the hollow spiral tube 53 is welded to the head end of the probe body 51, the tail end of the probe body 51 is sleeved with a hard rubber sleeve 55, the hard rubber sleeve 55 is connected to the probe body 51 as a whole, and the head end of the hollow spiral tube 53 is fixedly connected to the hard rubber sleeve 55; the probe bodies 51 of all megasonic probes 50 are arranged inside the hydraulic oil tank 20, and the probe heads 52 are located outside the hydraulic oil tank 20. The hollow spiral tube 53 is filled with mercury, and the ratio of the volume of mercury in the hollow spiral tube 53 to the volume of the hollow spiral tube 53 is x, x=0.73.

[0037] The megasonic probe consisting of the probe body 51 and the probe head 52 is purchased from Shijiazhuang Jingsuo Electronics Co., Ltd.

[0038] First, the hydraulic oil tank 20 and the buffer space are filled with inert gas, and the air pressure in the hydraulic oil tank 20 is initially at normal pressure; when the hydraulic module 10, the hydraulic oil inlet pipeline 11, the hydraulic oil return pipeline 12, etc. are in the process of hydraulic transmission operation, the liquid level of the hydraulic oil in the hydraulic oil tank 20 fluctuates continuously, the air pressure in the hydraulic oil tank 20 fluctuates continuously, and the airbag 32 contracts and expands continuously, so that the air pressure in the hydraulic oil tank 20 is maintained in a dynamic balance at normal pressure. In this way, the hydraulic transmission needs of the hydraulic module 10 are met. At the same time, the hydraulic oil tank 20 can be in a closed state, and there is almost no water vapor in the air therein, and no condensed water is generated, thereby significantly delaying the frequency of replacement of the hydraulic oil.

[0039] In some other embodiments, a fourth solenoid valve 22 communicating with the inner cavity of the hydraulic oil tank 20 is installed on the outer side of the hydraulic oil tank 20 .

[0040] Secondly, at the beginning, it is necessary to replace all the air in the hydraulic oil tank 20 with inert gas. This can be done by first closing the second solenoid valve 36, opening the first solenoid valve 39 and the fourth solenoid valve 22, and then using a vacuum pump to connect the fourth solenoid valve 22. When the air pressure in the hydraulic oil tank 20 is evacuated to a vacuum degree of -91.3 kPa, a part of the airbag 32 falls onto the inner support frame 33, which can effectively prevent the airbag 32 from clogging the first solenoid valve 39; thereafter, the first solenoid valve 39 is closed, and the vacuum pump continues to evacuate until the vacuum degree reaches -10 kPa, then the evacuation is stopped; the fourth solenoid valve 2 is closed. 2. Open the valve on the gas cylinder and the third solenoid valve 38. The inert gas in the gas cylinder passes through the third solenoid valve 38, the upper vertical pipe 37, the second solenoid valve 36, and the lower vertical pipe 34, thereby rushing into the buffer space. At the same time, open the first solenoid valve 39 until the air pressure in the hydraulic oil tank 20 returns to normal pressure. Finally, open the fourth solenoid valve 22, and continue to use the vacuum pump to evacuate the hydraulic oil tank 20 for 3 to 5 minutes. After the evacuation is completed, close the fourth solenoid valve 22, and the air pressure in the hydraulic oil tank 20 returns to normal pressure. Close the second solenoid valve 36, the third solenoid valve 38, and the valve on the gas cylinder. In the above process, due to the obstruction of the inner support frame 33, the airbag 32 will not cause blockage of the lower end of the lower vertical pipe 34.

[0041] In some embodiments, in order to facilitate observation of the air pressure in the hydraulic oil tank 20 , a pressure gauge for monitoring the air pressure inside the hydraulic oil tank 20 is installed on the outer wall of the hydraulic oil tank 20 .

[0042] Example 2

[0043] Based on Example 1, the inner support frame 33 includes at least four arc-shaped rods arranged in a central symmetrical manner, the upper ends of the arc-shaped rods are fixedly connected to the lower part of the lower vertical pipe 34, and the lower ends of the arc-shaped rods are fixedly connected to the box top 21.

[0044] The inner support frame 33 with such a structure can avoid blockage caused by excessive contraction of the airbag 32.

[0045] Example 3

[0046] For easy installation, the side wall of the hydraulic oil tank 20 is provided with a through hole matching the hard rubber sleeve 55 , the hard rubber sleeve 55 is inserted into the through hole and sealed, and a flange 54 is also installed between the probe head 52 and the hard rubber sleeve 55 .

[0047] Example 4

[0048] In Example 1, the oil foam elimination device is started, the frequency of the megasonic waves emitted by the probe body 51 is 8.6 MHz or 10.3 MHz, and the frequencies of the megasonic waves emitted by two adjacent probe bodies 51 are not equal, so as to perform a foam elimination operation on the hydraulic oil inside the hydraulic oil tank 20 .

[0049] For example, four rows of megasonic probes 50 are arranged inside the hydraulic oil tank 20, with six megasonic probes 50 in each row, and the distance between two adjacent megasonic probes 50 is 36 cm. Calculated from the bottom row, the megasonic frequency emitted by the first probe body 51 is 8.6 MHz, the megasonic frequency emitted by the second probe body 51 is 10.3 MHz, the megasonic frequency emitted by the third probe body 51 is 8.6 MHz, the megasonic frequency emitted by the fourth probe body 51 is 10.3 MHz, and so on.

[0050] The megasonic probe 50 can complete the defoaming operation by being started for 10 minutes every hour.

[0051] The interior of the hollow spiral tube 53 is not filled with mercury, and mercury will continue to fluctuate under the impact of sound waves, so that more complex vibrations or even resonance can be generated with the help of the hollow spiral tube 53, which is conducive to defoaming. In addition, the Brinell hardness of the hard rubber sleeve 55 is 85 degrees. The main function of the hard rubber sleeve 55 is to reduce the impact of mercury or sound wave rebound force, and effectively prevent a large amount of oil foam from adhering to the inner wall of the hydraulic oil tank 20.

[0052] Example 5

[0053] The difference between this example and Example 4 is that the hollow spiral tube 53 is not provided in this example, and the rest is the same.

[0054] Example 6

[0055] The difference between this example and Example 4 is that in this example, two hollow straight tubes are used to replace the hollow spiral tube 53, and the sum of the volumes of the two hollow straight tubes is equal to the hollow spiral tube 53, and the rest are the same.

[0056] Example 7

[0057] The difference between this example and Example 4 is that the frequency of the megasonic waves emitted by the probe body 51 of this example is 8.6 MHz, and the rest are the same.

[0058] Example 8

[0059] The difference between this example and Example 4 is that the frequency of the megasonic waves emitted by the probe body 51 of this example is 10.3 MHz, and the rest are the same.

[0060] Example 9

[0061] The difference between this example and Example 4 is that carbon dioxide is used instead of the inert gas, and the rest is the same.

[0062] Example 10

[0063] The difference between this example and Example 4 is that the Brinell hardness of the hard rubber sleeve 55 in this example is 70 degrees, and the rest are the same.

[0064] Embodiment 11

[0065] The difference between this example and Example 4 is that a metal sleeve is used to replace the hard rubber sleeve 55, and the rest is the same.

[0066] The test results of Examples 4 to 11 according to the "Defoaming Simulation Test" are shown in Table 1:

[0067]

[0068]

[0069] Example 12

[0070] It was found in the experiment that the mercury content inside the hollow spiral tube 53 and the different x values ​​would have a great influence on the area of ​​the oil foam layer. The specific results are shown in Figure 6 .

[0071] Depend on Figure 6 It can be seen that x is preferably 0.73.

[0072] 《Defoaming simulation test》

[0073] A hole is opened in the side wall of the hydraulic oil tank, and then filled with tempered glass to make a simulated oil tank for easy observation (the tempered glass area on the top of the simulated oil tank is 0.5m 2 ). The water content of the hydraulic oil in operation is 0.05%. Take photos to observe whether there is an oil foam layer on the liquid surface, and calculate the area of ​​the oil foam layer by the grid method; the thickness of the oil foam layer on the edge of the tempered glass is also calculated by the grid method. Due to the limitation of the field of view, the area of ​​the oil foam layer observed is less than 0.5m 2 In each test, the defoaming operation was carried out for 30 minutes, and then photos were taken and measured. The test was repeated 5 times and the average value was taken.

[0074] In the experiment, it was found that if ultrasonic defoaming is used, that is, the existing ultrasonic rod is used or the existing ultrasonic rod is used to replace the megasonic probe rod 50, the ultrasonic frequency ranges from 20 to 200kHz, and it is found that the defoaming operation cannot be completed. After consulting the data, the inventor speculates that ultrasonic waves will produce a strong cavitation effect, causing the bubbles to break; however, ultrasonic waves will cause more bubbles to be generated; generally there are three processes: the formation, growth and violent collapse of cavitation bubbles into small bubbles. Figure 5 This is a photo of the oil foam layer observed on the side wall of a simulated oil tank when an existing ultrasonic rod was tested at 200kHz.

[0075] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0076] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A hydraulic control system for a heavy-duty mechanical equipment, comprising a hydraulic module (10) for providing hydraulic power to the heavy-duty mechanical equipment, a hydraulic oil tank (20), a hydraulic oil inlet pipeline (11) for conveying hydraulic oil in the hydraulic oil tank (20) to the hydraulic module (10), and a hydraulic oil return pipeline (12) for conveying hydraulic oil in the hydraulic module (10) back to the hydraulic oil tank (20), characterized in that: It also includes an air pressure balancing device (30) for balancing the air pressure inside and outside the hydraulic oil tank (20), and an oil foam eliminating device for eliminating oil foam in the hydraulic oil tank (20).

2. A hydraulic control system for heavy-duty mechanical equipment according to claim 1, characterized in that: The top of the hydraulic oil tank (20) is provided with a tank top (21), and the air pressure balancing device (30) comprises a gas cylinder storing an inert gas, a cover installed above the tank top (21), a first solenoid valve (39) installed in the center of the tank top (21), a spherical crown-shaped air bag (32), an inner support frame (33) located in the air bag (32), a second solenoid valve (36) installed in the center of the top of the air bag (32), a third solenoid valve (38) installed on the top of the cover, an upper vertical pipe (37) for connecting the third solenoid valve (38) and the second solenoid valve (36), and a lower vertical pipe (34) located below the second solenoid valve (36), wherein the lower end of the cover is sealedly connected to the tank top (21) and encloses an activity chamber (3 1), a connecting rod (35) is fixedly installed between the second solenoid valve (36) and the inner wall of the cover, the upper end of the lower vertical pipe (34) is connected to the lower end of the second solenoid valve (36), the lower end of the lower vertical pipe (34) extends into the interior of the inner support frame (33), the lower end of the inner support frame (33) is fixedly connected to the box top (21), a buffer space is surrounded between the airbag (32) and the box top (21), the buffer space and the inner cavity of the hydraulic oil tank (20) are connected or closed through the first solenoid valve (39), and the buffer space and the second solenoid valve (36) are connected through the lower vertical pipe (34); a pressure reducing valve is arranged at the bottle mouth of the gas cylinder, and the pressure reducing valve is connected to the third solenoid valve (38).

3. A hydraulic control system for heavy-duty mechanical equipment according to claim 2, characterized in that: An inner mounting ring (321) is embedded in the center of the airbag (32), and the inner mounting ring (321) is connected to the airbag (32) as a whole. A mounting hole (322) adapted to the lower vertical pipe (34) is provided in the center of the inner mounting ring (321). An outer mounting ring (333) is integrally connected to the outer periphery of the airbag (32), and the outer mounting ring (333) is sealed and connected to the box top (21). The inner mounting ring (321) is fixedly connected to the connecting rod (35).

4. A hydraulic control system for heavy-duty mechanical equipment according to claim 2, characterized in that: The inner support frame (33) comprises at least four arc-shaped rods arranged in a centrally symmetrical manner, the upper ends of the arc-shaped rods are fixedly connected to the lower part of the lower vertical pipe (34), and the lower ends of the arc-shaped rods are fixedly connected to the box top (21).

5. The hydraulic control system for heavy-duty mechanical equipment according to claim 1, characterized in that: A fourth solenoid valve (22) is installed on the outer side of the hydraulic oil tank (20) and is in communication with the inner cavity of the hydraulic oil tank (20).

6. The hydraulic control system for heavy-duty mechanical equipment according to claim 1, characterized in that: The oil foam elimination device comprises megasonic probes (50) arranged in an array, the megasonic probes (50) comprising a probe body (51), a probe head (52), and a hollow spiral tube (53) sleeved on the outside of the probe body (51), the hollow spiral tube (53) being a cylindrical spiral structure, the tail end of the hollow spiral tube (53) being welded to the head end of the probe body (51), the tail end of the probe body (51) being sleeved with a hard rubber sleeve (55), the hard rubber sleeve (55) being sleeved on the outside of the probe body (51), and the hollow spiral tube (53) being sleeved on the outside of the probe body (51). 5) is connected to the probe body (51) as a whole, and the head end of the hollow spiral tube (53) is fixedly connected to the hard rubber sleeve (55); the probe body (51) of all megasonic probes (50) is arranged inside the hydraulic oil tank (20), and the probe head (52) is located outside the hydraulic oil tank (20); the hollow spiral tube (53) is filled with mercury, and the ratio of the volume of mercury in the hollow spiral tube (53) to the volume of the hollow spiral tube (53) is x, x=0.

73.

7. A hydraulic control system for heavy-duty mechanical equipment according to claim 6, characterized in that: The side wall of the hydraulic oil tank (20) is provided with a through hole matching the hard rubber sleeve (55), the hard rubber sleeve (55) is inserted into the through hole and sealed, and a flange (54) is also installed between the probe head (52) and the hard rubber sleeve (55).

8. The hydraulic control system for heavy-duty mechanical equipment according to claim 6, characterized in that: When the oil foam elimination device is activated, the megasonic wave frequency emitted by the probe rod body (51) is 8.6 MHz or 10.3 MHz, and the megasonic wave frequencies emitted by two adjacent probe rod bodies (51) are not equal, thereby performing a foam elimination operation on the hydraulic oil inside the hydraulic oil tank (20).

9. The hydraulic control system for heavy-duty mechanical equipment according to claim 1, characterized in that: An air pressure gauge for monitoring the internal air pressure of the hydraulic oil tank (20) is installed on the outer wall of the hydraulic oil tank (20).

10. The hydraulic control system for heavy-duty mechanical equipment according to claim 2, characterized in that: The inert gas is nitrogen or argon.

Images