CN221054034U - Air filtering structure on hydraulic oil tank - Google Patents

Abstract

The application relates to the technical field of hydraulic oil tank filtering systems, in particular to an air filtering structure on a hydraulic oil tank, which comprises a filtering device connected to a hydraulic oil tank vent, wherein the filtering device comprises a connecting cylinder directly connected with the hydraulic oil tank vent and a first filtering component arranged at the end part of the connecting cylinder far away from the vent, a second filtering component is arranged outside the first filtering component and comprises an air filter element sleeved outside the first filtering component, a protection component used for blocking large-particle pollutants is arranged outside the air filter element, an air flow channel for air circulation is formed between the protection component and the air filter element, and an air flow opening for air flow is arranged between the protection component and the air filter element and at a position close to the connecting cylinder. The application has the effects of improving the efficiency of filtering air and prolonging the service life of the filter element.

Description

Air filtering structure on hydraulic oil tank

Technical Field

The application relates to the technical field of hydraulic oil tank filtering systems, in particular to an air filtering structure on a hydraulic oil tank.

Background

The main effect of hydraulic tank is to store fluid, in addition plays the heat dissipation to fluid, impurity deposit and make the air in the fluid escape etc. and whether according to the oil tank liquid level with the atmosphere communicate with each other, the oil tank can divide into open and closed two kinds, and open oil tank is arranged in general hydraulic system, generally is arranged in large-scale construction vehicle, needs to use hydraulic oil to control the motion of equipment like: large-scale construction vehicles such as excavators; closed tanks are used in hydraulic systems under water and with stringent requirements for working stability and noise.

The hydraulic oil tank mainly comprises main components such as a oiling joint, an air filter, a thermometer, a liquid level meter, a filter, a tank body, a blow-down valve and the like, and an oil suction pipe and an oil return pipe are designed in the tank body so as to ensure that the hydraulic oil tank has the function of supplementing or recovering oil for a hydraulic system. In order to adjust the internal and external pressure difference in the hydraulic oil tank, an air vent is often required to be arranged on the oil tank, and the air vent enables the inside of the hydraulic oil tank to be communicated with the outside atmosphere so as to meet the requirements of the oil tank in the oil transportation and oil return processes, and meanwhile, the air entering the oil tank needs to be kept clean, so that hydraulic oil cannot be polluted. In the hydraulic system, the working oil is purified in a quite important link, and the air filter can keep the oil in the oil tank clean, so that dirt particles can be prevented from entering the oil tank from the outside, and the working period and the service life of the oil and elements can be prolonged, thereby ensuring the normal operation of the hydraulic system.

In the related art, in order to guarantee that the air in the entering hydraulic tank keeps clean constantly, can install air cleaner in the air vent department generally to filter the air in entering the oil tank, current when filtering air, outdoor dust impurity can directly adsorb on air cleaner's the filter core, after long-time use, can block up the filter core, accelerate the filter core and lose effect.

Disclosure of utility model

In order to improve the efficiency of filtering air and the service life of a filter element, the application provides an air filtering structure on a hydraulic oil tank.

The application provides an air filtering structure on a hydraulic oil tank, which adopts the following technical scheme:

The utility model provides an air filter structure on hydraulic tank, includes the filter equipment of connection in hydraulic tank air vent department, filter equipment includes the connecting cylinder of being connected with hydraulic tank air vent lug connection and installs the first filter component that keeps away from the air vent tip at the connecting cylinder, the outside of first filter component is provided with the second filter component, the outside air filter core at first filter component is established including the cover to the second filter component, air filter core's externally mounted has the protection subassembly that is used for blockking big particle pollutant, form the air current passageway that supplies the circulation of air between protection subassembly and the air filter core to be provided with the air current opening that supplies the air flow between protection subassembly and the air filter core and be close to the position department of connecting cylinder.

Through adopting above-mentioned technical scheme, when filtering the air that enters into hydraulic tank, the outside protective component can filter external large granule impurity earlier, then the air of preliminary filtration flows into the air current passageway from the air current opening part, then filters the dust impurity in the air through the second filter component, finally carries out the filtration at last through first filter component, and the clean air of filtration finally enters into hydraulic tank, through the above-mentioned filtration structure of setting, has improved the efficiency of filtered air; in the filtering process, the annular air filter element plays a role in filtering dust impurities, so that the dust impurities can be adsorbed on the air filter element, and the annular air filter element sleeved on the first filtering component can allow outside air to enter the hydraulic oil tank from the periphery, and can filter more air in unit time, thereby meeting the normal work of the hydraulic system; the protective component is arranged outside the air filter element, so that the air filter element can block a large amount of particle impurities, and the air filter element can be used for a longer time.

Optionally, the protection subassembly includes the cover and establishes the protective housing in the outside of air filter, the protective housing is inside cavity and one side open-ended structure, the opening of protective housing sets up towards the connecting cylinder to the lower extreme opening edge of protective housing is less than air filter's lower extreme edge.

Through adopting above-mentioned technical scheme, can mix dust and granule impurity in the air at the external air in-process of inhaling, because the lower limb of protecting crust is less than air filter's lower extreme edge, make the air of mixed impurity only flow into inside from the lower extreme of protecting crust, at the air that contains impurity in the flow in-process, can produce the collision with the protecting crust, great granule impurity can be popped out under the effect of striking after the protecting crust, thereby realized filtering the effect of partly great granule impurity, and can prevent that granule impurity from directly contacting with air filter.

Optionally, the protecting shell is in a truncated cone shape, and the protecting shell is in a structure with a small upper end and a large lower end.

Through adopting the technical scheme, after the outside air containing impurities is in contact with the outer wall of the protective shell, the particle impurities in the air can be thrown off or impacted to the protective shell along the shape of the protective shell under the action of inertia, and the particle impurities are ejected out of the position far away from the protective shell, so that larger particle impurities are prevented from being accumulated at the position around the protective shell; through the structure of the protecting shell with the small upper part and the big lower part, the air flow opening at the lower end of the protecting shell can be made to be relatively larger, so that the air flow with larger flow rate can be filtered.

Optionally, the first filter component includes the first filter screen of installing in the connecting cylinder upper end and fixes the fixed ring of connection in first filter screen upper end, the fixed ring of connection is connected with the protecting crust.

Through adopting above-mentioned technical scheme, when filtering the air that contains impurity, because the outside of first filter component is encircleed and is provided with air filter, the first filter screen of setting and the fixed ring of connection can provide the support to air filter on the one hand, let air filter better filter impurity air, on the other hand, in air through air filter can flow into hydraulic tank through first filter screen to first filter screen can also filter once more air after the air filter filters, play fine filtration's effect at last.

Optionally, be fixed with annular backup pad on the outer wall of connecting cylinder, the air filter lower extreme is installed in the backup pad.

Through adopting above-mentioned technical scheme, after the air filter cover is established on first filter screen, air filter's lower extreme can support in the backup pad, provide the support for air filter to the backup pad that sets up can play the effect of location, after the air filter lower extreme is installed in the backup pad, makes air filter can accomplish the parcel on first filter screen, lets the air after the air filter filters can enter into hydraulic tank through first filter screen.

Optionally, the second filter component comprises a reinforcement arranged on the air filter element, the reinforcement comprises a lower supporting fixing ring which is sleeved outside the connecting cylinder in a sliding manner and an upper supporting fixing ring which is sleeved on the first filter screen in a sliding manner, and the air filter element is positioned between the upper supporting fixing ring and the lower supporting fixing ring.

Through adopting above-mentioned technical scheme, the reinforcement that sets up has increased air filter's structural strength, lets air filter can be all the time around setting up in the outside of first filter screen, when installing air filter, makes second filter component slip cap establish on first filter screen, after air filter uses for a long time, can conveniently change air filter.

Optionally, a second filter screen is sleeved outside the air filter element, and the second filter screen is located between the upper support fixing ring and the lower support fixing ring.

Through adopting above-mentioned technical scheme, outside air filters the preceding through air filter, carries out preliminary filtration through the second filter screen line that sets up earlier, can filter in advance to some large granule impurity, avoids large granule impurity direct adsorption to air filter on, in addition, the second filter screen that sets up cooperates with last support solid fixed ring and lower support solid fixed ring to connect into whole, improved the intensity of second filter element, avoid when installing air filter, go up support solid fixed ring and lower support solid fixed ring and extrude air filter.

Optionally, be provided with the sealing member between first filter component and the second filter component, the sealing member seals the gap of the both ends position department about just being close to between air filter core and the first filter screen.

Through adopting above-mentioned technical scheme, the sealing member that sets up can seal the gap between first filter component and the second filter component, prevents that external air from entering into hydraulic tank from the gap of these two places not through filtering.

Optionally, the protection subassembly still includes the mounting that fixes the protecting crust, the mounting is including setting up at the inside mount of first filter screen, mount one end is fixed with the connecting cylinder, the mount upper end is provided with fixing bolt, fixing bolt upwards passes mount, connection solid fixed ring and protecting crust to threaded connection has fixation nut on the fixing bolt, fixation nut compresses tightly on the protecting crust.

Through adopting above-mentioned technical scheme, the mounting that sets up can fix the protecting crust of outside, makes it can dismantle to fix on first filtration subassembly, makes things convenient for the staff to change air filter element.

Optionally, the connecting cylinder is sleeved with a hoop near the outside of the vent.

Through adopting above-mentioned technical scheme, the staple bolt that sets up can make convenient dismantlement of filter equipment in hydraulic tank's air vent department, installs and overhauls more conveniently.

In summary, the present application includes at least one of the following beneficial technical effects:

1. According to the filter device provided by the application, when the air containing impurities in the outside is filtered, the protective shell can play a role in preliminary filtration, stone particles or massive impurity particles in the air are filtered firstly, then smaller dust and impurity particles can be filtered by the second filter screen and the air filter element, finally, the filtered clean air can enter the hydraulic oil tank through the first filter screen, the first filter screen can also be used for filtering the air again, and the air containing impurities can be filtered cleanly through the three-layer filter structure arranged from outside to inside;

2. the protective shell on the filtering device can prevent large particle impurities in the air from being directly adsorbed on the second filter screen and the air filter element, so that the service life of the air filter element is prolonged.

Drawings

Fig. 1 is a schematic overall structure of a first embodiment of the present application.

Fig. 2 is a schematic view of an integrated air filter cartridge according to an embodiment of the present application.

FIG. 3 is a schematic diagram of an embodiment of the present application incorporating a first filter assembly and a second filter assembly.

FIG. 4 is a schematic view showing an oil-repellent plate and a purge ring according to an embodiment of the present application.

Reference numerals illustrate: 1. a connecting cylinder; 11. a support plate; 12. an oil-resistant plate; 2. a first filter assembly; 21. a first filter screen; 22. connecting a fixed ring; 3. a second filter assembly; 31. an air filter element; 32. a reinforcement; 321. an upper support fixing ring; 322. a lower support fixing ring; 33. a second filter screen; 4. a protective assembly; 41. a protective shell; 411. a cleaning ring; 42. a fixing member; 421. a fixing frame; 422. a fixing bolt; 423. a fixing nut; 5. an air flow channel; 6. an air flow opening; 7. a seal ring; 8. and (5) hooping.

Detailed Description

The application is described in further detail below with reference to fig. 1-4.

The embodiment of the application discloses an air filtering structure on a hydraulic oil tank.

In a large-scale construction vehicle, a hydraulic system for controlling various mechanical devices is generally provided, and when the hydraulic system is operated, the oil level in a hydraulic oil tank is raised or lowered in accordance with the operation process, in order to ensure the normal operation of the hydraulic system, a vent hole communicated with the outside is generally formed in the hydraulic oil tank, when the oil level in the oil tank is raised, air is discharged from inside to outside, and when the oil level in the oil tank is lowered, air is sucked from outside to inside.

Example 1

Referring to fig. 1, an air filtering structure on a hydraulic oil tank includes a filtering device connected to a vent of the hydraulic oil tank, and can filter outside air by the filtering device, thereby avoiding outside impurities from being inhaled into the hydraulic oil tank.

Referring to fig. 1 and 2, the filtering device comprises a connecting cylinder 1 which is in a cylindrical structure and is vertically arranged, the lower end of the connecting cylinder 1 is detachably fixed at a vent, a first filtering component 2 is arranged at the upper end of the connecting cylinder 1, a second filtering component 3 is arranged outside the first filtering component 2 in a surrounding manner, and the outside air is subjected to double-layer filtering through the arranged first filtering component 2 and second filtering component 3, so that impurities in the outside air are prevented from being sucked into a hydraulic oil tank; the first filter component 2 comprises a first filter screen 21 arranged at the upper end of the connecting cylinder 1, the first filter screen 21 is of a cylindrical structure, the lower end of the first filter screen 21 can be in plug-in connection with the connecting cylinder 1, an annular connecting fixing ring 22 is fixed at the upper end of the first filter screen 21, and when outside air is filtered, outside particle impurities can be isolated by the first filter screen 21 and prevented from entering a hydraulic oil tank.

Referring to fig. 1 and 2, the second filter assembly 3 includes an air filter 31 installed outside the first filter 21, the air filter 31 has a cylindrical structure, the air filter 31 is sleeved on the first filter 21, and an inner wall of the air filter 31 is attached to an outer wall of the first filter 21, in the embodiment of the present application, the air filter 31 can be selected according to an environment where a construction vehicle is constructed, and the air filter 31 can be a paper filter, a chemical fiber filter, a mesh filter, etc., so long as the filter can be used to filter dust impurities in air; the cross section of the air filter element 31 is wavy, so that the area for filtering dust and impurities can be increased when air is filtered, the flow rate of air flow passing through the air filter element in a unit time period can be increased, the filtering efficiency is improved, and in addition, the strength of the air filter element 31 can be improved due to the wavy cross section; the second filter component 3 further comprises a reinforcement 32 for reinforcing the air filter element 31, the reinforcement 32 comprises an upper supporting fixing ring 321 arranged at the upper end of the air filter element 31 and a lower supporting fixing ring 322 arranged at the lower end of the air filter element 31, the cross sections of the upper supporting fixing ring 321 and the lower supporting fixing ring 322 are U-shaped, openings of the upper supporting fixing ring 321 and the lower supporting fixing ring 322 are arranged in opposite directions, the air filter element 31 is located between the upper supporting fixing ring 321 and the lower supporting fixing ring 322 and is fixedly connected with the upper supporting fixing ring 321 and forms an integral structure, the upper supporting fixing ring 321 can be slidably sleeved outside the connecting fixing ring 22, the lower supporting fixing ring 322 can be slidably sleeved outside the connecting cylinder 1, the structural strength of the air filter element 31 is increased through the arranged reinforcement 32, the air filter element 31 can be always arranged outside the first filter screen 21 in a surrounding mode, and the second filter component 3 is slidably sleeved on the first filter screen 21 when the air filter element 31 is installed.

Referring to fig. 2 and 3, the second filter assembly 3 further includes a second filter screen 33 wrapped outside the air filter element 31, the upper end of the second filter screen 33 is inserted and matched in the upper support fixing ring 321, the lower end of the second filter screen 33 is inserted and matched in the lower support fixing ring 322, external air is initially filtered through a set second filter screen 33 line before being filtered through the air filter element 31, and some large-particle impurities can be filtered out first, so that the large-particle impurities are prevented from being directly adsorbed on the air filter element 31, in addition, the set second filter screen 33 is matched with the upper support fixing ring 321 and the lower support fixing ring 322 and connected into a whole, the strength of the second filter assembly 3 is improved, and the upper support fixing ring 321 and the lower support fixing ring 322 are prevented from extruding the air filter element 31 when the air filter element 31 is installed; in the embodiment of the present application, the mesh diameter of the second filter screen 33 is larger than the mesh diameter of the first filter screen 21, so that the first filter screen 21 can play a role in final filtration protection, and air passing through the first filter screen 21 can directly enter the hydraulic oil tank.

The annular supporting plate 11 which is horizontally and outwards extended is fixedly connected to the outer wall of the connecting cylinder 1, after the second filter assembly 3 is installed outside the first filter screen 21, the lower supporting and fixing ring 322 can be installed on the supporting plate 11 to integrally provide support for the second filter assembly 3 and also can play a role in positioning, and after the lower supporting and fixing ring 322 is installed on the supporting plate 11, the second filter assembly 3 is proved to be installed in place, so that the condition of inaccurate installation position is avoided; in the embodiment of the present application, the height of the second filter screen 33 is the same as that of the air filter screen 31, and the height of the second filter screen 33 and the air filter screen are greater than that of the first filter screen 21, and when the first filter assembly 2 is installed, the air filter screen 31 can fully cover the meshes of the first filter screen 21, so that air which is not filtered by the second filter assembly 3 is prevented from directly entering the hydraulic oil tank through the first filter screen 21.

Referring to fig. 2 and 3, a protection assembly 4 is installed at the outside of the second filter assembly 3, the protection assembly 4 includes a protection case 41 covered at the outside of the second filter assembly 3, the protection case 41 is of a structure having an inner hollow and one end opened, and the opened side of the protection case 41 is disposed downward, the upper inner surface of the protection case 41 is attached to the connection fixing ring 22, the lower end edge of the protection case 41 is lower than the lower end edge of the air filter 31, when the protection case 41 is covered at the outside of the second filter assembly 3, an annular air flow channel 5 is formed between the protection case 41 and the air filter 31, and an air flow opening 6 through which external air flows toward the air filter 31 is formed between the opened side of the protection case 41 and the air filter 31, when the external air is inhaled into the hydraulic oil tank, the external air flows into the air flow channel 5 from the air flow opening 6, and is then filtered once through the second filter screen 33, the air filter 31 and the first filter screen 21, and finally the filtered clean air is inhaled into the hydraulic oil tank; the protective shell 41 is of a round table-shaped structure with a small upper end and a large lower end, in the process of filtering outside air, the lower end edge of the protective shell 41 is matched with the lower end edge structure of the air filter element 31, outside air can only enter through the air flow opening 6, in the process of entering outside air through the air flow opening 6, some larger particle pollutants can be thrown away in advance after impacting the outer wall of the protective shell 41 due to inertia effect through the round table-shaped structure of the protective shell 41 and fall outside the protective shell 41, when the larger particle pollutants are sucked into the protective shell 41, small stone particles can impact the inner wall of the shell and pop out, so that dust particles are attached to the inner wall of the protective shell 41, the filtering efficiency is improved, and through the conical structural design of the protective shell 41, preliminary physical filtration is performed, and more large particle impurities are prevented from being sucked into the protective shell 41.

Referring to fig. 2 and 3, the protection assembly 4 further includes a fixing member 42 fixing the protection case 41, the fixing member 42 includes a fixing frame 421 vertically disposed inside the first filter screen 21, the fixing frame 421 is V-shaped, and an opening of the fixing frame 421 is disposed downward, a lower end of the fixing frame 421 is fixed to an inner wall of the connection cylinder 1, a fixing bolt 422 vertically penetrates through an upper end of the fixing frame 421, the fixing bolt 422 is located at an axis of the connection cylinder 1, the fixing bolt 422 penetrates through the fixing frame 421, the connection fixing ring 22 and the protection case 41 in sequence, the fixing bolt 422 penetrates through a center of the connection fixing ring 22, and the fixing bolt 422 penetrates through the protection case 41, a fixing nut 423 is connected to the fixing bolt 422 and is located on an outer thread of the protection case 41, and the fixing nut 423 can be screwed onto the protection case 41, when the protection case 41 is installed, a worker buckles the protection case 41 on the connection fixing ring 22, then penetrates the fixing bolt 422 onto the fixing frame 421, and finally screws the fixing nut 423 onto the fixing bolt 422.

The first filtering component 2 and the second filtering component 3 are provided with sealing pieces, the sealing pieces comprise a pair of flexible sealing rings 7, the two sealing rings 7 are symmetrically arranged at the upper end and the lower end of the air filter element 31, the sealing ring 7 at the upper end is positioned between the protective shell 41 and the upper supporting fixed ring 321, the sealing ring 7 at the lower end is positioned between the supporting plate 11 and the lower supporting fixed ring 322, when the second filtering component 3 and the protective shell 41 are installed, the two sealing rings 7 are gradually compressed in the process of tightening the fixed nut 423, so that a gap between the protective shell 41 and the upper supporting fixed ring 321 and a gap between the supporting plate 11 and the lower supporting fixed ring 322 are in a sealed state, and external air is prevented from entering a hydraulic oil tank from the gaps at the two positions without being filtered; the outer wall of the connecting cylinder 1, which is close to the vent, is sleeved with the anchor ear 8, and when the filtering device is installed at the vent of the hydraulic oil tank, the connecting cylinder 1 is spliced and matched at the vent, and then the anchor ear 8 is screwed, so that the filtering device is firmly connected with the hydraulic oil tank.

The implementation principle of the air filtering structure on the hydraulic oil tank provided by the embodiment of the application is as follows: when the air entering the hydraulic oil tank is filtered, the filtering of large-particle impurities is carried out through the protective shell 41, then the dust is filtered through the second filter screen 33 and the air filter element 31, and then the air which is filtered and catches up is entering the hydraulic oil tank through the first filter screen 21, so that the normal work of a hydraulic system is met.

Example 2

Referring to fig. 1 and 4, this embodiment is different from embodiment 1 in that a plurality of oil-proof plates 12 are fixedly connected to the inner wall of the connecting cylinder 1, the plurality of oil-proof plates 12 are all inclined downward, and the plurality of oil-proof plates 12 are disposed in opposite directions on the outer wall far away from the connecting cylinder 1 and partially overlap each other, the plurality of oil-proof plates 12 form curved passages inside the connecting cylinder 1, and when oil in the hydraulic oil tank is sucked and discharged, if too much oil in the hydraulic oil tank is sprayed outward, the oil is blocked by the disposed oil-proof plates 12, so that the oil is prevented from being sprayed into the air filter element 31.

Fixedly connected with cleans ring 411 on the inner wall of protecting crust 41, clean ring 411 is made by flexible material, a plurality of clean ring 411 evenly set up from top to bottom to clean ring 411 keeps away from the one side of protecting crust 41 inner wall and all inclines down to set up and support to second filter screen 33, set up the opening that supplies the air current to pass through on cleaning ring 411, avoid appearing the problem that the air input reduces, misplacement setting between the upper and lower adjacent clean ring 411, in the hydraulic tank in the in-process of breathing in and exhausting, clean ring 411 can take place crooked elastic deformation, the inboard edge of clean ring 411 that supports on second filter screen 33 can clean the surface of second filter screen 33, clean the dust that will attach, improve filter equipment's life, avoid needing frequent change.

The implementation principle of the embodiment 2 is as follows: the cleaning ring 411 can clean the surface of the second filter screen 33 in the process of air suction and exhaust inside the hydraulic oil tank, so that the particulate impurities and dust are prevented from being attached to the second filter screen 33 for a long time, and the oil-proof plate 12 can prevent oil in the hydraulic oil tank from splashing to the air filter element 31, so that the process quantity performance of the air filter element 31 is reduced.

The above embodiments are not intended to limit the scope of the present application, so: all equivalent changes in structure, shape and principle of the application should be covered in the scope of protection of the application.

Claims (10)

1. An air filtering structure on hydraulic tank, its characterized in that: including connecting the filter equipment in hydraulic tank air vent department, filter equipment includes connecting cylinder (1) and installs first filter component (2) of keeping away from the air vent tip at connecting cylinder (1) with hydraulic tank air vent lug connection, the outside of first filter component (2) is provided with second filter component (3), second filter component (3) are including the cover and establish at the outside air filter core (31) of first filter component (2), the externally mounted of air filter core (31) has protection component (4) that are used for blockking big particle pollutant, form air flow channel (5) that supply the circulation of air between protection component (4) and air filter core (31) to be provided with between protection component (4) and air filter core (31) and be close to the position department of connecting cylinder (1) and supply air flow's air current opening (6).

2. An air filtering structure on a hydraulic oil tank according to claim 1, wherein: the protection component (4) comprises a protection shell (41) which is covered outside the air filter element (31), the protection shell (41) is of a structure with a hollow inside and one side open, the opening of the protection shell (41) is arranged towards the connecting cylinder (1), and the edge of the opening of the lower end of the protection shell (41) is lower than the edge of the lower end of the air filter element (31).

3. An air filtering structure on a hydraulic oil tank according to claim 2, wherein: the protective shell (41) is in a truncated cone shape, and the protective shell (41) is of a structure with a small upper end and a large lower end.

4. An air filtering structure on a hydraulic oil tank according to claim 1, wherein: the first filter assembly (2) comprises a first filter screen (21) arranged at the upper end of the connecting cylinder (1) and a connecting fixing ring (22) fixed at the upper end of the first filter screen (21), and the connecting fixing ring (22) is connected with the protective shell (41).

5. An air filtering structure on a hydraulic oil tank according to claim 1, wherein: an annular supporting plate (11) is fixed on the outer wall of the connecting cylinder (1), and the lower end of the air filter element (31) is mounted on the supporting plate (11).

6. An air filtering structure on a hydraulic oil tank according to claim 1, wherein: the second filter component (3) comprises a reinforcing member (32) arranged on the air filter element (31), the reinforcing member (32) comprises a lower supporting and fixing ring (322) which is sleeved outside the connecting cylinder (1) in a sliding mode and an upper supporting and fixing ring (321) which is sleeved on the first filter screen (21) in a sliding mode, and the air filter element (31) is located between the upper supporting and fixing ring (321) and the lower supporting and fixing ring (322).

7. An air filtering structure on a hydraulic oil tank according to claim 1, wherein: the outside cover of air filter core (31) is equipped with second filter screen (33), second filter screen (33) are located between upper support solid fixed ring (321) and lower support solid fixed ring (322).

8. An air filtering structure on a hydraulic oil tank according to claim 1, wherein: a sealing piece is arranged between the first filtering component (2) and the second filtering component (3), and the sealing piece seals a gap between the air filter element (31) and the first filter screen (21) and close to the upper end and the lower end.

9. An air filtering structure on a hydraulic oil tank according to claim 1, wherein: the protection subassembly (4) is still including carrying out fixed mounting (42) to protecting crust (41), mounting (42) are including setting up at inside mount (421) of first filter screen (21), mount (421) one end is fixed with connecting cylinder (1), mount (421) upper end is provided with fixing bolt (422), fixing bolt (422) upwards pass mount (421), connection solid fixed ring (22) and protecting crust (41) to threaded connection has fixation nut (423) on fixing bolt (422), fixation nut (423) compress tightly on protecting crust (41).

10. An air filtering structure on a hydraulic oil tank according to claim 1, wherein: the connecting cylinder (1) is sleeved with a hoop (8) near the outside of the vent.