An air cleaner for a construction machine, an automatic control system and method

Abstract

An air filter, automatic control system, and method for engineering machinery are disclosed. The air filter body contains a primary filtration structure, a secondary backflush filter element, a resistance heater I, a resistance heater II, an outlet pipe, and a backflush pipe. The primary filtration structure is located at the air inlet. The secondary backflush filter element is connected to a motor for rotation. The outlet end of the backflush pipe has several outlet holes. The resistance heater II is located at the outlet hole of the backflush pipe. The air filter body of this invention has two filter elements: the primary filter element is a cyclone tube assembly, which improves the dust removal rate; the secondary filter element is a rotatable backflush filter element, which improves the backflush efficiency. The air filter body also includes resistance heaters for heating and drying the intake air. The automatic control system includes two sets of air filters and several sensors and solenoid valves, etc. Through automatic control, the two air filters can be automatically switched, improving the equipment's working efficiency and service life.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, specifically to an air filter, automatic control system, and method for engineering machinery. Background Technology

[0002] Cleaning and maintaining diesel engine intake filters in the construction machinery industry is a recognized market challenge. Operators often lack awareness of engine protection and fail to maintain them in a timely manner, leading to frequent instances of diesel engine cylinder scoring. To reduce human-caused risks and labor costs, many companies have introduced backflushing air filters, which use high-pressure gas to backflush the filters at the end of the operation to remove dust.

[0003] However, because the intake system is a negative pressure system, this type of backflushing air filter can only be backflushed with compressed air when the engine is off. This may result in insufficient dust removal, leading to high intake resistance and alarms. Furthermore, it can only be backflushed once with compressed air after the engine stops operating, resulting in poor continuous dust removal. It also lacks a physical pre-filtration structure, causing the main filter element to accumulate dust too quickly, shortening the clogging alarm time. Additionally, it lacks a relatively complete backflushing system control logic for automatic monitoring, management, and protection of the engine intake system. Moreover, it cannot adapt to humid or cold operating environments. In humid conditions, the filter element may fail, potentially causing excessive intake resistance and alarms during startup. Similarly, freezing at low temperatures may trigger the same alarm, in which case backflushing is ineffective. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an air filter, automatic control system and method for engineering machinery with simple structure and good effect.

[0005] This invention is achieved through the following technical solution: an air filter for engineering machinery, comprising an air filter body, the air filter body including an upper shell and a lower shell, the upper end of the upper shell being provided with an end cap, the lower end of the upper shell being connected to the lower shell via a mounting flange, the upper part of the lower shell being an air inlet, the air filter body having a primary filtration structure located near the air inlet, the lower part of the lower shell having a conical dust collector for the primary filtration structure, the lower end of the conical dust collector being provided with a dust discharge valve; the air filter body also having an air outlet pipe, the upper part of the air outlet pipe having a hollow cylindrical secondary back-blowing filter element, the secondary back-blowing filter element being connected to a motor for rotation, the air inlet end of the air outlet pipe being provided with a resistance heater I; the air outlet pipe having a back-blowing air pipe inside, the air outlet end of the back-blowing air pipe having several air outlet holes, the portion of the back-blowing air pipe having air outlet holes being wrapped with a resistance heater II, and the air filter body having several back-blowing dust discharge ports and dust discharge valves for use during back-blowing.

[0006] Furthermore, the air inlet is a ring-shaped mesh structure.

[0007] The primary filtration structure is a cyclone tube assembly, which is arranged around the lower housing. The lower end of the conical dust collector is provided with a cyclone tube dust discharge port connected to the dust discharge valve.

[0008] The upper and lower ends of the secondary backflush filter element are respectively provided with an upper tray and a lower tray. The connection between the secondary backflush filter element and the upper tray and the lower tray is provided with an upper bearing and a lower bearing. The upper end of the air filter body is provided with a motor to control the rotation of the secondary backflush filter element.

[0009] The air filter body has four back-blowing ash discharge ports evenly distributed below the mounting flange. The ash discharge valve is made of rubber and has a normally closed horn-shaped structure. The ash discharge valve is closed when the air filter is in operation and opens when back-blowing.

[0010] An automatic control system for an air filter used in engineering machinery includes two air filters, each with a motor connected to its upper end. One air filter is equipped with a relative humidity sensor. The outlet pipe of each air filter is connected to a safety air filter via a pressure sensor and a solenoid valve. A temperature sensor is installed at the inlet of the safety air filter. The outlet of the safety air filter is connected to a turbocharger and an air compressor. The inlet of the turbocharger is equipped with a pressure sensor. The air compressor is connected to an electromagnetic clutch. The outlet of the air compressor is connected to an air cylinder via a solenoid valve and a check valve. The outlet of the air cylinder is connected to the backflush pipe of the air filter. The inlet of the backflush pipe of each air filter is equipped with a check valve and a solenoid valve.

[0011] The air compressor is equipped with a one-way valve at the air inlet.

[0012] An automatic control method for an air filter used in construction machinery adjusts the operating mode based on temperature, humidity, and pressure values, specifically including:

[0013] A. Two seconds after the device is powered on, the gas temperature in the safety air filter intake pipe is collected by the temperature sensor. If the temperature is ≤-15℃, the resistance heater I is turned on to provide auxiliary heating for the engine intake air and improve low-temperature start performance. It is turned off after receiving the engine start signal.

[0014] B. When the relative humidity sensor collects a relative humidity of ≥60%, or the temperature sensor collects a temperature of ≤0℃, the resistance heater II is turned on, motor I and motor II are turned on, and solenoid valves I and II are turned on at the same time, while solenoid valves III and IV are turned off to perform back-flushing drying operation; when the relative humidity drops below 60% and the temperature is above 0℃, the resistance heater II, motor I and motor II are turned off, and solenoid valves I and II are turned off at the same time, while solenoid valves III and IV are turned on.

[0015] C. After the engine starts, when solenoid valve III opens and solenoid valve IV closes, air filter I works normally;

[0016] When Pa-Pc>P0, Pa is the value of pressure sensor I, Pc is the value of pressure sensor III, and P0 is the negative pressure limit of the backflush air filter. Solenoid valve IV is opened in sequence, and solenoid valve III is closed. At this time, air filter II works normally, solenoid valve I is opened for backflush, and motor I is turned on, rotating forward for 30 seconds and then in reverse for 30 seconds to perform backflush through centrifugal force and compressed air.

[0017] When Pb-Pc>P0, Pb is the value of pressure sensor II. Solenoid valve III is opened sequentially, and solenoid valve IV is closed. At this time, air filter I works normally, solenoid valve II is opened for backflushing, and motor II is turned on. It rotates forward for 30 seconds and then reverses for 30 seconds. After the backflushing limit is cycled n times, an alarm prompts to replace the backflushing filter element.

[0018] When Pa-Pc > P1 or Pb-Pc > P1, P1 is the replacement limit for the safety filter element, and an alarm will be triggered to indicate that the safety filter element needs to be replaced.

[0019] When Pd < P2, Pd is the value of pressure sensor IV, and P2 is the set value of backflush compressed air pressure. The electromagnetic clutch and solenoid valve V open simultaneously, and vice versa, to keep the backflush air supply sufficient and stable.

[0020] The present invention has the following advantages: The air filter, automatic control system, and method for engineering machinery of the present invention have two-stage filter elements in the air filter body. The first-stage filter element is a cyclone tube assembly, which can improve the dust removal rate and slow down the dust accumulation rate of the back-blowing filter element. The second-stage filter element is a rotatable back-blowing filter element, which improves the back-blowing efficiency. At the same time, the air filter body is also equipped with a resistance heater for heating and drying the intake gas. The automatic control system is equipped with two sets of air filters and several sensors and solenoid valves and other electrical components. Through the automatic control method, the two air filters can be automatically switched, achieving the effect of back-blowing the filter element while the engine is working normally. It also solves the problem that the filter element may fail in humid and low-temperature environments, improving the working efficiency and service life of the equipment. Attached Figure Description

[0021] The accompanying drawings, as part of this invention, are provided to further illustrate the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0022] In the attached diagram:

[0023] Figure 1 This is a schematic diagram of the air filter of the present invention;

[0024] Figure 2 This is a schematic diagram of the internal structure of the air filter of the present invention;

[0025] Figure 3 This is a schematic diagram of the automatic control system for the air filter of the present invention;

[0026] Figure 4 This is a schematic diagram of the automatic control method for air filters according to the present invention;

[0027] Figure 5 This is a schematic diagram of the cyclone tube assembly of the present invention;

[0028] Figure 6 This is a schematic diagram of the ash discharge valve of the present invention.

[0029] In the diagram: 1. Solenoid Valve I, 2. Solenoid Valve II, 3. Solenoid Valve III, 4. Solenoid Valve IV, 5. Solenoid Valve V, 6. Electromagnetic Clutch, 7. Gas Cylinder, 8. Air Compressor, 9. Engine, 10. Safety Air Filter, 11-A. Air Filter I, 11-B. Air Filter II, 12-A. Motor I, 12-B. Motor II, 13-A. Pressure Sensor I, 13-B. Pressure Sensor II, 13-C. Pressure Sensor III, 13-D. Pressure Sensor IV, 14. Turbocharger, 15. Temperature Sensor, 16. Relative Humidity Sensor, 17-A. Check Valve I, 17-B. Check Valve II 17-C, One-way valve III; 17-D, One-way valve IV; 11-1, End cap; 11-2, Air filter body; 11-3, Mounting flange; 11-4, Backflush ash discharge port; 11-5, Air inlet; 11-6, Cyclone tube assembly; 11-7, Cyclone tube ash discharge port; 11-8, Air outlet pipe; 11-9, Lower tray; 11-10, Resistance heater I; 11-11, Backflush air pipe; 11-12, Lower bearing; 11-13, Resistance heater II; 11-14, Secondary backflush filter element; 11-15, Upper bearing; 11-16, Upper tray; 11-17, Dust discharge valve; 11-18, Ash discharge valve.

[0030] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0032] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] like Figures 1 to 2 An air filter for engineering machinery is shown, comprising an air filter body 11-2. The air filter body 11-2 includes an upper shell and a lower shell. The upper end of the upper shell is provided with an end cap 11-1, and the lower end of the upper shell is connected to the lower shell via a mounting flange 11-3. The upper part of the lower shell is an air inlet 11-5. The air filter body 11-2 has a primary filtration structure located near the air inlet 11-5. The lower part of the lower shell is a conical dust collector for the primary filtration structure, and the lower end of the conical dust collector is provided with a dust discharge valve 11-17. The air filter body 11-2 also has an air outlet pipe 11- 8. The upper part of the air outlet pipe 11-8 is provided with a hollow cylindrical secondary back-blowing filter element 11-14. The secondary back-blowing filter element 11-14 is connected to a motor for rotation. The air inlet end of the air outlet pipe 11-8 is provided with a resistance heater I 11-10. The inside of the air outlet pipe 11-8 is provided with a back-blowing air pipe 11-11. The air outlet end of the back-blowing air pipe 11-11 is provided with several air outlet holes. The part of the back-blowing air pipe 11-11 with air outlet holes is wrapped with a resistance heater II 11-13. The outside of the air filter body 11-2 is provided with several back-blowing ash discharge ports 11-4 and ash discharge valves 11-18 used during back-blowing. The air filter of the present invention includes a backflush pipe 11-11 mounted on its central shaft. The end of the backflush pipe has a mesh structure and is fixed inside the outlet pipe 11-8. Two sets of resistance heaters 11-10 / 11-13 are mounted along the path of the backflush pipe to dry the backflush filter element and heat the engine intake air.

[0035] like Figures 1 to 2The air filter for engineering machinery shown has an air inlet 11-5 with a ring-shaped mesh structure. The air filter of this invention has a mesh structure for its air inlet, a large ventilation area due to the ring-shaped arrangement, and a swirl tube assembly on one side of the air inlet, which increases air intake efficiency.

[0036] like Figures 1 to 2 and Figure 5 The air filter for engineering machinery shown has a primary filtration structure of a cyclone tube assembly 11-6, which is arranged around the lower housing. The lower end of the conical dust collector is provided with a cyclone tube dust discharge port 11-7 connected to a dust discharge valve 11-17. This invention features a cyclone tube assembly 11-6 arranged in a ring on the inner side of the air inlet. This assembly filters out 95% of large dust particles through the centrifugal force of the rotating airflow and the gravity of the dust particles themselves. The dust particles are then discharged through the dust discharge valve at the bottom of the cyclone tube, improving the dust removal efficiency of the air filter. The cyclone tube assembly includes an inner tube and an outer tube with a gap between them. The lower end of the inner tube is connected to the outer tube via cyclone fins. The upper gap between the cyclone fins serves as the air inlet. Air enters the cyclone tube through the inlet and passes through the cyclone fins, generating centrifugal force that causes over 90% of large dust particles to be discharged through the tube wall to the bottom dust discharge valve. The gas then passes through the inner tube into the backflushing air filter, achieving preliminary filtration and improving the dust removal efficiency of the air filter.

[0037] like Figures 1 to 2 The air filter for engineering machinery shown has an upper tray 11-16 and a lower tray 11-9 at its upper and lower ends, respectively, for the secondary backflush filter element 11-14. An upper bearing 11-15 and a lower bearing 11-12 are provided at the connection between the secondary backflush filter element 11-14 and the upper and lower trays 11-16 and 11-9. A motor for controlling the rotation of the secondary backflush filter element 11-14 is located at the upper end of the air filter body 11-2. The secondary backflush filter element of this invention is equipped with a rotation mechanism. The secondary backflush filter element is mounted between the lower and upper trays, with lower and upper bearings respectively fixed to the air filter body and end cap. Power is provided by a motor located outside the air filter body, driving the secondary backflush filter element to rotate. The centrifugal force of the rotating filter element helps to solve the problem of poor backflush effect, improving backflush efficiency.

[0038] like Figures 1 to 2 and Figure 6The air filter for engineering machinery shown has four back-blowing ash discharge ports 11-4 evenly distributed below the mounting flange 11-3 on the air filter body 11-2. The ash discharge valve 11-18 is made of rubber and has a normally closed horn shape. The ash discharge valve 11-18 is closed when the air filter is in operation and opens during back-blowing. The air filter body of this invention is provided with a mounting flange, and four back-blowing ash discharge ports are evenly distributed at 90° intervals at the bottom of the flange. Each back-blowing ash discharge port is equipped with an ash discharge valve made of rubber with a V-shaped cross-section. It is normally closed. When the air filter is working normally, the inside of the air filter is under negative pressure, the ash discharge ports are closed, and the ash discharge valve remains closed. During back-blowing, the inside is under positive pressure, and the ash discharge ports open to discharge ash.

[0039] like Figure 3An automatic control system for an air filter used in construction machinery is shown, comprising two air filters, each with a motor connected to its upper end. One air filter is equipped with a relative humidity sensor 16. The outlet pipe of each air filter is connected to a safety air filter 10 via a pressure sensor and a solenoid valve. A temperature sensor 15 is installed at the inlet of the safety air filter 10. The outlet of the safety air filter 10 is connected to a turbocharger 14 and an air compressor 8. The inlet of the turbocharger 14 is equipped with a pressure sensor. The air compressor 8 is connected to an electromagnetic clutch 6. The outlet of the air compressor 8 is connected to a gas cylinder 7 via a solenoid valve and a check valve. The outlet of the gas cylinder 7 is connected to the backflush pipe of the air filter. The inlet of the backflush pipe of each air filter is equipped with a check valve and a solenoid valve. The inlet of the air compressor 8 is equipped with a check valve. The engine intake management system of this invention uses two air filters, which are placed in parallel. By switching between them, the engine can be cleaned without stopping the engine. Specifically, there are two air filters: air filter I11-A and air filter II11-B. Motors I12-A and II12-B are respectively connected to the upper parts of air filter I11-A and air filter II11-B. A relative humidity sensor is installed on air filter I11-A to collect the relative humidity of the air entering the air filter. Pressure sensor I13-A and solenoid valve III3 are installed at the outlet of air filter I11-A. Pressure sensor II13-B and solenoid valve IV4 are installed at the outlet of air filter II11-B. The pipelines after solenoid valves III3 and IV4 are merged. After the pipelines are merged, a temperature sensor 15 is installed. The temperature sensor 15 is used to detect the temperature of the air entering the engine 9, so as to facilitate the timely detection of temperature abnormalities and facilitate subsequent operations. A safety air filter 10 is connected in series after the temperature sensor 15. The air compressor then splits into two paths. One path, equipped with pressure sensor Ⅲ13-C, enters the engine turbocharger 14. The other path, equipped with one-way valve Ⅳ17-D, connects to the air intake of the air compressor 8. The input shaft of the air compressor 8 is connected to the electromagnetic clutch 6, which is controlled by a pressure feedback signal. The outlet of the air compressor 8 connects to the gas cylinder 7, with solenoid valve Ⅴ5 and one-way valve Ⅲ17-C in between. Pressure sensor Ⅳ13-D is installed on the gas cylinder to monitor its pressure. The outlet of the gas cylinder 7 splits into two paths, each connecting to a separate air filter. The backflush pipe of the filter provides backflush air to the two air filters. Specifically, the branch connecting air filter I11-A is equipped with solenoid valve I1 and check valve I17-A, and the branch connecting air filter II11-B is equipped with solenoid valve II2 and check valve II17-B. By operating solenoid valve I1 and solenoid valve II, the backflush of air filter I11-A or air filter II11-B is controlled. Among them, solenoid valve I1, solenoid valve II, solenoid valve III3 and solenoid valve IV4 are one-position three-way solenoid directional valves.

[0040] like Figure 4The method shown is an automatic control method for an air filter used in construction machinery, which adjusts the working mode according to temperature, humidity, and pressure values, specifically including:

[0041] A. Two seconds after the device is powered on, the gas temperature in the intake pipe of the safety air filter 10 is collected by the temperature sensor 15. If the temperature is ≤-15℃, the resistance heater I 11-10 is turned on to provide auxiliary heating for the engine intake air and improve low-temperature starting performance. It is turned off after receiving the engine start signal. After the device is powered on, the intake air temperature is first detected by the temperature sensor. If the intake air temperature is too low, the resistance heater I is turned on to provide auxiliary heating to increase the intake air temperature until the engine start conditions are met. Then the resistance heater I is turned off.

[0042] B. When the relative humidity sensor 16 collects a relative humidity ≥ 60%, or the temperature sensor 15 collects a temperature ≤ 0℃, the resistance heater II11-13 is turned on, motors I12-A and II12-B are turned on, and solenoid valves I1 and II2 are turned on, while solenoid valves III3 and IV4 are turned off to perform back-flushing drying. When the relative humidity drops below 60% and the temperature is above 0℃, the resistance heater II11-13, motors I12-A and II12-B are turned off, and solenoid valves I1 and II2 are turned off, while solenoid valves III3 and IV4 are turned on. After the system is running, if the temperature and humidity do not meet the requirements, the reverse system of the air filter is started to perform reverse drying until the temperature and humidity requirements are met, and then the air filter is started to operate normally.

[0043] C. After engine 9 is started, when solenoid valve Ⅲ3 is opened and solenoid valve Ⅳ4 is closed, air filter Ⅰ11-A works normally;

[0044] When Pa-Pc>P0, Pa is the value of pressure sensor I13-A, Pc is the value of pressure sensor III13-C, and P0 is the negative pressure limit of the backflushing air filter. Solenoid valve IV4 is opened sequentially, and solenoid valve III3 is closed. At this time, air filter II11-B operates normally, solenoid valve I1 opens for backflushing, and motor I12-A starts, rotating forward for 30 seconds and then reverse for 30 seconds to perform backflushing using centrifugal force and compressed air. During system operation, the system pressure is monitored in real time by various pressure sensors. When the pressure difference between pressure sensor I13-A and pressure sensor III13-C exceeds the negative pressure limit of the backflushing air filter, air filter I11-A needs to be closed, and backflushing of air filter I11-A is required to reduce the dust density on the secondary backflushing filter element, thereby reducing the normal intake pressure of air filter I11-A.

[0045] When Pb-Pc>P0, Pb is the value of pressure sensor II13-B. Solenoid valve III3 opens sequentially, and solenoid valve IV4 closes. At this time, air filter I11-A operates normally, solenoid valve II2 opens for backflushing, and motor II12-B starts, rotating forward for 30 seconds and then reverse for 30 seconds, cycling this backflushing cycle n times until an alarm sounds, prompting the replacement of the backflushing filter element. When the pressure in air filter II11-B is too high, the backflushing principle is the same as for air filter I11-A.

[0046] When Pa-Pc > P1 or Pb-Pc > P1, P1 is the replacement limit for the safety filter element, and an alarm is triggered to indicate that the safety filter element needs to be replaced. This invention includes an alarm system. When the pressure difference between pressure sensor I13-A and pressure sensor III13-C, or the pressure difference between pressure sensor II13-B and pressure sensor III13-C, exceeds the replacement limit for the safety filter element, the safety filter element needs to be replaced to improve the safety of the system.

[0047] When Pd < P2, where Pd is the value of pressure sensor Ⅳ13-D and P2 is the set value of backflush compressed air pressure, electromagnetic clutch 6 and electromagnetic valve V5 open simultaneously; conversely, they close simultaneously to maintain a sufficient and stable backflush air supply. This invention includes a safe operating procedure for the gas cylinder. When the gas cylinder pressure is lower than the backflush compressed air pressure, the gas cylinder needs to be refilled to ensure normal system operation.

[0048] This invention discloses an air filter for engineering machinery, comprising a cyclone tube assembly. By adding a cyclone tube pre-filtration structure, the initial filtration of heavy ash is enhanced, slowing down the ash accumulation rate of the backflushing filter element. The secondary backflushing filter element is connected to a rotating device, which uses the centrifugal force of the filter element's rotation to assist in solving the problem of poor backflushing effect. It also includes two sets of resistance heating devices and automatic control logic to adapt to humid or cold equipment application environments, addressing the problem of filter element failure and backflushing failure in humid and low-temperature environments. The automatic control system and method for the air filter for engineering machinery of this invention includes two sets of air filter assemblies, sensors, and solenoid valve components. Through a complete backflushing system control and protection program, and two automatic switching modes for the two air filters, it automatically monitors, manages, and protects the engine intake system, reducing the labor costs of equipment maintenance and enabling filter element backflushing operations while the engine is operating normally, thus improving equipment uptime efficiency. Furthermore, this invention adds an electromagnetic clutch structure to the engine air compressor to control the backflushing compressed air pressure, providing stable backflushing compressed air while protecting the backflushing filter element.

[0049] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0050] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this invention and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

[0051] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An air filter for engineering machinery, characterized in that: The air filter includes an air filter body (11-2), which comprises an upper housing and a lower housing. The upper housing has an end cap (11-1) at its upper end and is connected to the lower housing via a mounting flange (11-3). The upper part of the lower housing is an air inlet (11-5). The air filter body (11-2) contains a primary filtration structure near the air inlet (11-5). The lower part of the lower housing contains a conical dust collector for the primary filtration structure, with a dust discharge valve (11-17) at its lower end. The air filter body (11-2) also contains an air outlet pipe (11-8). 8) The upper part is provided with a hollow cylindrical secondary back-blowing filter element (11-14). The secondary back-blowing filter element (11-14) is connected to a motor for rotation. The air inlet end of the air outlet pipe (11-8) is provided with a resistance heater I (11-10). The air outlet pipe (11-8) is provided with a back-blowing air pipe (11-11) inside. The air outlet end of the back-blowing air pipe (11-11) is provided with several air outlet holes. The part of the back-blowing air pipe (11-11) with air outlet holes is wrapped with a resistance heater II (11-13). The air filter body (11-2) is provided with several back-blowing ash discharge ports (11-4) and ash discharge valves (11-18) for use during back-blowing.

2. The air filter for engineering machinery as described in claim 1, characterized in that: The air inlet (11-5) has a ring-shaped mesh structure.

3. An air filter for engineering machinery as described in claim 1, characterized in that: The primary filtration structure is a cyclone tube assembly (11-6), which is arranged around the lower housing. The lower end of the conical dust collector is provided with a cyclone tube dust discharge port (11-7) connected to the dust discharge valve (11-17).

4. An air filter for engineering machinery as described in claim 1, characterized in that: The upper and lower ends of the secondary backflush filter element (11-14) are respectively provided with an upper tray (11-16) and a lower tray (11-9). The connection between the secondary backflush filter element (11-14) and the upper tray (11-16) and the lower tray (11-9) is provided with an upper bearing (11-15) and a lower bearing (11-12). The upper end of the air filter body (11-2) is provided with a motor to control the rotation of the secondary backflush filter element (11-14).

5. An air filter for engineering machinery as described in claim 1, characterized in that: The air filter body (11-2) has four back-blowing ash discharge ports (11-4) evenly distributed below the mounting flange (11-3). The ash discharge valve (11-18) is made of rubber and has a normally closed horn shape. The ash discharge valve (11-18) is closed when the air filter is in operation and opened when back-blowing.

6. An automatic control system using the air filter for construction machinery as described in claim 1, characterized in that: It includes two air filters, each with a motor connected to its upper end. One of the air filters is equipped with a relative humidity sensor (16). The outlet pipe of each air filter is connected to a safety air filter (10) via a pressure sensor and a solenoid valve. The inlet of the safety air filter (10) is equipped with a temperature sensor (15). The outlet of the safety air filter (10) is connected to a turbocharger (14) and an air compressor (8). The inlet of the turbocharger (14) is equipped with a pressure sensor. The air compressor (8) is connected to an electromagnetic clutch (6). The outlet of the air compressor (8) is connected to a gas cylinder (7) via a solenoid valve and a check valve. The outlet of the gas cylinder (7) is connected to the backflush pipe of the air filter. The inlet of the backflush pipe of each air filter is equipped with a check valve and a solenoid valve.

7. The automatic control system for an air filter for engineering machinery as described in claim 6, characterized in that: The air compressor (8) is equipped with a one-way valve at the air inlet end.

8. An automatic control system method using an air filter for engineering machinery as described in claim 6, characterized in that: The operating mode is adjusted according to temperature, humidity, and pressure values, specifically including: A. After the device is powered on for 2 seconds, the gas temperature of the safety air filter (10) intake pipe is collected by the temperature sensor (15); if the temperature is ≤-15℃, the resistance heater I (11-10) is turned on to provide auxiliary heating for the engine intake and improve the low temperature start performance. It is turned off after receiving the engine start signal. B. When the relative humidity collected by the relative humidity sensor (16) is ≥60%, or the temperature collected by the temperature sensor (15) is ≤0℃, the resistance heater II (11-13) is turned on, the motor I (12-A) and the motor II (12-B) are turned on, and at the same time the solenoid valve I (1) and the solenoid valve II (2) are turned on, and the solenoid valve III (3) and the solenoid valve IV (4) are turned off to perform back-blowing drying operation; when the relative humidity drops below 60% and the temperature is greater than 0℃, the resistance heater II (11-13), the motor I (12-A) and the motor II (12-B) are turned off, and at the same time the solenoid valve I (1) and the solenoid valve II (2) are turned off, and the solenoid valve III (3) and the solenoid valve IV (4) are turned on. C. After the engine (9) is started, when solenoid valve III (3) is opened and solenoid valve IV (4) is closed, air filter I (11-A) works normally; When Pa-Pc>P0, Pa is the value of pressure sensor I (13-A), Pc is the value of pressure sensor III (13-C), and P0 is the negative pressure limit of the backflush air filter. Solenoid valve IV (4) is opened in sequence, and solenoid valve III (3) is closed. At this time, air filter II (11-B) works normally, solenoid valve I (1) is opened for backflush, and motor I (12-A) is opened. It rotates forward for 30 seconds and reverses for 30 seconds to backflush through centrifugal force and compressed air. When Pb-Pc>P0, Pb is the value of pressure sensor II (13-B). Solenoid valve III (3) is opened in sequence, and solenoid valve IV (4) is closed. At this time, air filter I (11-A) works normally, solenoid valve II (2) is opened for backflushing, and motor II (12-B) is opened. It rotates forward for 30 seconds and then reverses for 30 seconds. After the backflushing limit is cycled n times, an alarm prompts to replace the backflushing filter element.

9. The automatic control method for an air filter for engineering machinery as described in claim 8, characterized in that: When Pa-Pc > P1 or Pb-Pc > P1, P1 is the replacement limit for the safety filter element, and an alarm will be triggered to indicate that the safety filter element needs to be replaced.

10. The automatic control method for an air filter for engineering machinery as described in claim 8, characterized in that: When Pd < P2, Pd is the value of pressure sensor Ⅳ (13-D), P2 is the backflush compressed air pressure setting value, electromagnetic clutch (6) and electromagnetic valve Ⅴ (5) open at the same time, and vice versa, to keep the backflush air source sufficient and stable.

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