Air filter for engineering machinery and automatic control system and method

Abstract

The invention relates to an air filter for engineering machinery and an automatic control system and method.The air filter comprises an air filter body, a first-stage filtering structure, a second-stage reverse blowing filter element, a first resistance heater, a second resistance heater, an air outlet pipe and a reverse blowing air pipe are arranged in the air filter body, the first-stage filtering structure is arranged at an air inlet, and the second-stage reverse blowing filter element is connected with a motor to rotate; a plurality of air outlet holes are formed in the air outlet end of the blowback air pipe; and the resistance heater II is arranged at the air outlet holes of the blowback air pipe. The air filter body is provided with the two stages of filter elements, the first-stage filter element is the rotational flow pipe assembly and can improve the dust removal rate, the second-stage filter element is the rotatable reverse blowing filter element and can improve the reverse blowing efficiency, and meanwhile the air filter body is further provided with the resistance heater used for heating and drying sucked air; two groups of air filters are arranged in the automatic control system, a plurality of sensors, electromagnetic valves and other electrical elements are arranged, two air filter automatic switching modes are achieved through an automatic control method, the working efficiency of the equipment is improved, and the service life of the equipment is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of engineering machinery, and in particular to an air filter, an automatic control system and a method for engineering machinery. Background Art

[0002] The cleaning and maintenance of diesel engine air intake filters in the construction machinery industry is a recognized market problem. Operators lack awareness of engine protection and fail to maintain the engine in a timely manner, which often leads to diesel engine cylinder scuffing. To reduce human risks and labor costs, many companies have introduced backflush air filters, which use high-pressure gas to backflush at the end of the operation to expel dust.

[0003] However, because the air intake system is a negative pressure system, the current back-blowing air filter can only be back-blown using compressed air when the engine is stopped. It may not be able to be cleaned in time, resulting in large intake resistance and an alarm. At the same time, it can only be back-blown once with compressed air after the engine stops operating. It cannot continuously clean the dust and the effect is poor. There is no physical pre-filtration structure, and the main filter element accumulates dust too quickly, shortening the blockage alarm time. There is no relatively complete back-blowing system control logic to automatically monitor, manage and protect the engine intake system. In addition, it cannot adapt to humid or cold equipment application environment conditions. The filter element may fail in humid environmental conditions. At startup, the intake resistance may be too large and an alarm may be sounded, or ice may appear at low temperatures and the same alarm may be sounded. At this time, back-blowing will not be very effective. Summary of the invention

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

[0005] The present invention is implemented by the following technical scheme: an air filter for engineering machinery, comprising an air filter body, the air filter body comprising an upper shell and a lower shell, the upper end of the upper shell is provided with an end cover, the lower end of the upper shell is connected to the lower shell by a mounting flange, the upper part of the lower shell is an air inlet, a primary filtering structure is provided in the air filter body at a position close to the air inlet, the lower part of the lower shell is a conical ash collector of the primary filtering structure, and a dust discharge valve is provided at the lower end of the conical ash collector; an air outlet pipe is also provided in the air filter body, a hollow cylindrical secondary back-blowing filter element is provided at the upper part of the air outlet pipe, the secondary back-blowing filter element is connected to a motor for rotation, and a resistance heater I is provided at the air inlet end of the air outlet pipe; a back-blowing air pipe is provided inside the air outlet pipe, a plurality of air outlet holes are provided at the air outlet end of the back-blowing air pipe, and a resistance heater II is wrapped at the position where the air outlet holes are provided in the back-blowing air pipe, and a plurality of back-blowing ash discharge ports and ash discharge valves used during back-blowing are provided outside the air filter body.

[0006] Furthermore, the air inlet is a mesh structure arranged in a ring shape.

[0007] The primary filtering structure is a cyclone assembly, which is arranged in a circle in the lower shell. The lower end of the conical ash collector is provided with a cyclone ash discharge port connected to a dust discharge valve.

[0008] An upper tray and a lower tray are respectively disposed at the upper and lower ends of the secondary back-blowing filter element, an upper bearing and a lower bearing are disposed at the connection between the secondary back-blowing filter element and the upper tray and the lower tray, and a motor for controlling the rotation of the secondary back-blowing filter element is disposed at the upper end of the air filter body.

[0009] The air filter body is evenly distributed with four back-blowing ash discharge ports below the mounting flange. The material of the ash discharge valve is rubber. The structure of the ash discharge valve is a normally closed trumpet shape. The ash discharge valve is closed when the air filter is operating and is opened during back-blowing.

[0010] An automatic control system for an air filter for engineering machinery comprises two air filters, both upper ends of which are connected to motors, one of the air filters is provided with a relative humidity sensor, the air 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 provided at the air inlet of the safety air filter, the air outlet end of the safety air filter is respectively connected to a turbocharger and an air compressor, the air inlet end of the turbocharger is provided with a pressure sensor, the air compressor is connected to an electromagnetic clutch, the air outlet end of the air compressor is connected to a gas cylinder via a solenoid valve and a one-way valve, the air outlet end of the gas cylinder is connected to a back-blowing air pipe of the air filter, and the air inlet end of the back-blowing air pipe of each air filter is provided with a one-way valve and a solenoid valve.

[0011] A one-way valve is provided at the air inlet end of the air compressor.

[0012] An automatic control method for an air filter for engineering machinery, which adjusts the working mode according to temperature, humidity and pressure values, specifically includes: A. After the equipment is powered on for 2 seconds, the temperature sensor collects the gas temperature of the safety air filter intake pipe; if the temperature is ≤-15℃, the resistance heater I is turned on to assist the engine intake heating to improve the low-temperature starting performance, and it is turned off after receiving the engine start signal; B. When the relative humidity collected by the relative humidity sensor is ≥60%, or the temperature collected by the temperature sensor is ≤0℃, the resistance heater II is turned on, the motors I and II are turned on, and the solenoid valves I and II are turned on, and the solenoid valves III and IV are closed to perform back-blowing and drying operations; when the relative humidity drops below 60% and the temperature is greater than 0℃, the resistance heater II, motor I and II are turned off, and the solenoid valves I and II are closed, and the solenoid valves III and IV are turned on; C. After the engine is started, when the solenoid valve III is opened and the solenoid valve IV is closed, the air filter I works normally; When Pa-Pc>P0, Pa is the value of pressure sensor Ⅰ, Pc is the value of pressure sensor Ⅲ, P0 is the negative pressure limit of back-blowing 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 back-blowing, and motor Ⅰ is turned on at the same time, rotating forward for 30 seconds and reverse for 30 seconds to back-blow through centrifugal force and compressed air; When Pb-Pc>P0, Pb is the value of pressure sensor Ⅱ, solenoid valve Ⅲ is opened in sequence, and solenoid valve Ⅳ is closed. At this time, air filter Ⅰ works normally, solenoid valve Ⅱ is opened for backwashing, and motor Ⅱ is turned on at the same time, rotating forward for 30 seconds and reverse for 30 seconds. After the backwashing limit value is cycled n times in sequence, an alarm is issued to prompt the replacement of the backwashing filter element.

[0013] When Pa-Pc>P1 or Pb-Pc>P1, P1 is the replacement limit of the safety filter element, and an alarm prompts to replace the safety filter element.

[0014] When Pd<P2, Pd is the value of pressure sensor IV, P2 is the set value of back-blowing compressed air pressure, the electromagnetic clutch and electromagnetic valve V are opened at the same time, otherwise they are closed at the same time to keep the back-blowing air source sufficient and stable.

[0015] The present invention has the following advantages: the air filter, automatic control system and method for engineering machinery of the present invention, the air filter body is provided with a two-stage filter element, the first-stage filter element is a cyclone tube assembly, which can improve the dust removal rate and delay the dust accumulation speed of the back-blowing filter element, and the second-stage filter element is a rotatable back-blowing filter element to improve the back-blowing efficiency. At the same time, the air filter body is also provided with a resistance heater for heating and drying the inhaled gas; two groups of air filters are arranged in the automatic control system, and a number of electrical components such as sensors and solenoid valves are provided. Through the automatic control method, the two air filter automatic switching modes are realized, so as to achieve the effect of performing the filter element back-blowing operation while the engine is working normally, and also solve the problem that the filter element may fail in humid and low-temperature environmental conditions, thereby improving the working efficiency and service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the accompanying drawings described below are only some embodiments. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0017] In the attached picture: Figure 1 is a schematic diagram of an air filter of the present invention; Figure 2It is a schematic diagram of the internal structure of the air filter of the present invention; Figure 3 It is a schematic diagram of the automatic control system of the air filter of the present invention; Figure 4 is a schematic diagram of an automatic air filter control method of the present invention; Figure 5 It is a structural schematic diagram of the cyclone tube assembly of the present invention; Figure 6 It is a structural schematic diagram of the ash discharge valve of the present invention.

[0018] In the figure: 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 cover, 11-2, air filter body, 11-3, mounting flange, 11-4, back-blowing ash discharge port, 11-5, air inlet, 11-6, swirl tube assembly, 11-7, swirl tube ash discharge port, 11-8, air outlet pipe, 11-9, lower tray, 11-10, resistance heater I, 11-11, back-blowing air pipe, 11-12, lower bearing, 11-13, resistance heater II, 11-14, secondary back-blowing filter element, 11-15, upper bearing, 11-16, upper tray, 11-17, dust discharge valve, 11-18, ash discharge valve.

[0019] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0020] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0021] In the description of the present invention, it should be noted that the directions or positional relationships indicated by terms such as “upper”, “lower”, “front”, “back”, “left”, “right”, “vertical”, “inside” and “outside” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] like Figure 1 to Figure 2 An air filter for engineering machinery shown in the figure comprises an air filter body 11-2, the air filter body 11-2 comprises an upper shell and a lower shell, the upper end of the upper shell is provided with an end cover 11-1, the lower end of the upper shell is connected to the lower shell through a mounting flange 11-3, the upper part of the lower shell is an air inlet 11-5, a primary filtering structure is provided in the air filter body 11-2 near the air inlet 11-5, the lower part of the lower shell is a conical ash collector of the primary filtering structure, and a dust exhaust valve 11-17 is provided at the lower end of the conical ash collector; an air outlet pipe 11-1 is also provided in the air filter body 11-2 8. A hollow cylindrical secondary back-blowing filter element 11-14 is provided at the upper part of the air outlet pipe 11-8, and the secondary back-blowing filter element 11-14 is connected to a motor for rotation, and a resistance heater I 11-10 is provided at the air inlet end of the air outlet pipe 11-8; a back-blowing air pipe 11-11 is provided inside the air outlet pipe 11-8, and a plurality of air outlet holes are provided at the air outlet end of the back-blowing air pipe 11-11, and a resistance heater II 11-13 is wrapped at the portion where the air outlet holes are provided in the back-blowing air pipe 11-11, and a plurality of back-blowing ash discharge ports 11-4 and ash discharge valves 11-18 used during back-blowing are provided outside the air filter body 11-2. The air filter of the present invention has a back-blowing air pipe 11-11 arranged on the central axis of the air filter, the end of the back-blowing air pipe is a mesh structure fixed inside the air outlet pipe 11-8, and two groups of resistance heaters 11-10 / 11-13 are arranged on the back-blowing air pipe path to dry the back-blowing filter element and heat the engine intake air in cooperation with the back-blowing air pipe. like Figure 1 to Figure 2The air filter for engineering machinery shown in the figure has an air inlet 11-5 of a mesh structure arranged in an annular shape. The air inlet of the air filter of the present invention is a mesh structure, the annular arrangement has a large ventilation area, and a swirl tube assembly is arranged on one side of the air inlet to increase the air intake efficiency.

[0024] like Figure 1 to Figure 2 and Figure 5 An air filter for construction machinery is shown, wherein the primary filtering structure is a cyclone tube assembly 11-6, and the cyclone tube assembly 11-6 is arranged in a circle in the lower shell. The lower end of the conical ash collector is provided with a cyclone tube ash discharge port 11-7 connected to a dust discharge valve 11-17. The present invention has a swirl tube assembly 11-6 distributed in an annular manner on the inner side of the air inlet, which filters out 95% of large dust particles through the centrifugal force of air flow rotation and the gravity of the dust itself, and discharges the dust through the dust discharge valve at the bottom swirl tube dust discharge port, thereby improving the dust removal efficiency of the air filter. The swirl tube assembly includes an inner tube and an outer tube, and a gap is provided between the inner tube and the outer tube. The lower end of the inner tube is connected to the outer tube through a swirl fin, and the upper gap between the swirl fins is the air inlet. After the air enters the swirl tube from the air inlet, the swirl fins generate centrifugal force, so that more than 90% of the large dust particles are discharged through the tube wall to the bottom dust discharge valve for discharge, and the gas enters the back-blowing air filter through the inner tube to achieve preliminary filtration of the gas, which is beneficial to improving the dust removal efficiency of the air filter.

[0025] like Figure 1 to Figure 2 An air filter for engineering machinery is shown, wherein the upper and lower ends of the secondary back-blowing filter element 11-14 are respectively provided with an upper tray 11-16 and a lower tray 11-9, an upper bearing 11-15 and a lower bearing 11-12 are provided at the connection between the secondary back-blowing filter element 11-14 and the upper tray 11-16 and the lower tray 11-9, and a motor for controlling the rotation of the secondary back-blowing filter element 11-14 is provided at the upper end of the air filter body 11-2. The secondary back-blowing filter element of the present invention is provided with a slewing mechanism, the secondary back-blowing filter element is installed between the lower tray and the upper tray, and a lower bearing and an upper bearing are respectively provided at the upper and lower ends, which are respectively fixed on the air filter body and the end cover, and the motor provided outside the air filter body provides power to drive the secondary back-blowing filter element to rotate, and the problem of poor back-blowing effect is solved by the assistance of the rotating centrifugal force of the filter element, thereby improving the back-blowing efficiency.

[0026] like Figure 1 to Figure 2 and Figure 6The air filter for engineering machinery shown in the figure has four back-blowing ash discharge ports 11-4 evenly distributed below the mounting flange 11-3. The material of the ash discharge valve 11-18 is rubber. The structure of the ash discharge valve 11-18 is a normally closed trumpet. The ash discharge valve 11-18 is closed when the air filter is in operation and is opened during back-blowing. The air filter body of the present invention is provided with a mounting flange. Four back-blowing ash discharge ports are evenly distributed at 90° at the bottom of the flange. An ash discharge valve is provided on the back-blowing ash discharge port. The dust discharge valve is made of rubber and has a V-shaped cross-section. It is in a normally closed state. When the air filter is working normally, the inside of the air filter is in a negative pressure state, the ash discharge port is sucked in, and the dust discharge valve is always kept closed; during back-blowing, the inside is positive pressure, and the ash discharge port is opened to discharge ash.

[0027] like Figure 3The automatic control system of an air filter for engineering machinery shown in the figure includes two air filters, both of which are connected to motors at their upper ends, one of which is provided with a relative humidity sensor 16, the outlet pipe of each air filter is connected to a safety air filter 10 through a pressure sensor and a solenoid valve, the air inlet of the safety air filter 10 is provided with a temperature sensor 15, the outlet end of the safety air filter 10 is respectively connected to a turbocharger 14 and an air compressor 8, the air inlet end of the turbocharger 14 is provided with a pressure sensor, the air compressor 8 is connected to an electromagnetic clutch 6, the outlet end of the air compressor 8 is connected to a gas cylinder 7 through a solenoid valve and a one-way valve, the outlet end of the gas cylinder 7 is connected to the back-blowing air pipe of the air filter, and the air inlet end of the back-blowing air pipe of each air filter is provided with a one-way valve and a solenoid valve. The air inlet end of the air compressor 8 is provided with a one-way valve. Two air filters are selected on the engine intake management system of the present invention. The two air filters are placed in parallel. By switching between them, the engine can be cleaned without stopping. Specifically, they are air filter Ⅰ11-A and air filter Ⅱ11-B. The upper parts of air filter Ⅰ11-A and air filter Ⅱ11-B are respectively connected with motor Ⅰ12-A and motor Ⅱ12-B. A relative humidity sensor is installed on air filter Ⅰ11-A for collecting the relative humidity of the gas entering the air filter. A pressure sensor Ⅰ13-A and a solenoid valve Ⅲ3 are provided at the air outlet of air filter Ⅰ11-A. A pressure sensor Ⅱ13-B and a solenoid valve Ⅳ4 are provided at the air outlet of air filter Ⅱ11-B. The pipelines are merged after solenoid valve Ⅲ3 and solenoid valve Ⅳ4. After the pipelines are merged, a temperature sensor 15 is provided. The temperature sensor 15 is used to detect the temperature entering the engine 9, so as to facilitate timely detection of temperature abnormalities and facilitate subsequent operations. A safety air filter 10 is connected in series after the temperature sensor 15. After that, it is divided into two paths. One path is provided with a pressure sensor Ⅲ13-C and then enters the engine turbocharger 14; the other path is provided with a one-way valve Ⅳ17-D and then connected to the air inlet of the air compressor 8. The input shaft of the air compressor 8 is connected to the electromagnetic clutch 6, and its clutch is controlled by the pressure feedback signal; the outlet of the air compressor 8 is connected to the gas cylinder 7, and the electromagnetic valve Ⅴ5 and the one-way valve Ⅲ17-C are provided in the middle. The gas cylinder is provided with a pressure sensor Ⅳ13-D to monitor the pressure of the gas cylinder. The gas outlet of the gas cylinder 7 is divided into two paths and connected to two air filters respectively. The back-blowing air pipe of the air filter provides back-blowing air for the two air filters. Specifically, a solenoid valve I1 and a one-way valve I17-A are provided on the branch connected to the air filter I11-A, and a solenoid valve II2 and a one-way valve II17-B are provided on the branch connected to the air filter II11-B. By operating the solenoid valve I1 and the solenoid valve II, the back-blowing of the air filter I11-A or the air filter II11-B is controlled, wherein the solenoid valve I1, the solenoid valve II, the solenoid valve III3 and the solenoid valve IV4 are one-position three-way solenoid reversing valves.

[0028] like Figure 4The automatic control method of an air filter for engineering machinery shown in the figure adjusts the working mode according to the temperature, humidity and pressure value, and specifically includes: A. After the equipment is powered on for 2 seconds, the temperature sensor 15 collects the gas temperature of the intake pipe of the safety air filter 10; if the temperature is ≤-15℃, the resistance heater Ⅰ11-10 is turned on to assist the engine intake heating to improve the low-temperature starting performance, and it is turned off after receiving the engine start signal; after the equipment is powered on, the temperature sensor is used to detect the intake temperature first. If the intake temperature is too low, the resistance heater Ⅰ is turned on to assist the heating to increase the intake temperature until the engine start conditions are met, and then the resistance heater Ⅰ is turned off; 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°C, the resistance heater II 11-13 is turned on, the motor I 12-A and the motor II 12-B are turned on, and 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 closed to perform backwash drying operation; when the relative humidity drops below 60% and the temperature is greater than 0°C, the resistance heater II 11-13, the motor I 12-A and the motor II 12-B are turned off, and the solenoid valve I 1 and the solenoid valve II 2 are closed, and the solenoid valve III 3 and the solenoid valve IV 4 are turned on; after the system is in operation, if the temperature and humidity do not meet the standards, the reversal 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 for normal operation; C. After the engine 9 is started, when the solenoid valve III3 is opened and the solenoid valve IV4 is closed, the air filter I11-A works normally; When Pa-Pc>P0, Pa is the value of pressure sensor Ⅰ13-A, Pc is the value of pressure sensor Ⅲ13-C, P0 is the negative pressure limit of back-blowing air filter, solenoid valve Ⅳ4 is opened in sequence, and solenoid valve Ⅲ3 is closed. At this time, air filter Ⅱ11-B works normally, solenoid valve Ⅰ1 is opened for back-blowing, and motor Ⅰ12-A is turned on at the same time, rotates forward for 30 seconds and reverses for 30 seconds to back-blow through centrifugal force and compressed air; during the operation of the system, the system pressure is detected in real time through various pressure sensors. When the pressure difference between pressure sensor Ⅰ13-A and pressure sensor Ⅲ13-C is greater than the negative pressure limit of back-blowing air filter, air filter Ⅰ11-A needs to be closed and back-blown to reduce the dust density on the secondary back-blowing filter element, thereby reducing the normal intake pressure of air filter Ⅰ11-A; When Pb-Pc>P0, Pb is the value of pressure sensor Ⅱ13-B, solenoid valve Ⅲ3 is opened in sequence, and solenoid valve Ⅳ4 is closed. At this time, air filter Ⅰ11-A works normally, solenoid valve Ⅱ2 is opened for back-blowing, and motor Ⅱ12-B is turned on at the same time, rotating forward for 30 seconds, reverse for 30 seconds, and circulates the back-blowing limit value n times in sequence, and then an alarm prompts to replace the back-blowing filter element. When the pressure of air filter Ⅱ11-B is too high, the back-blowing principle is the same as that of air filter Ⅰ11-A.

[0029] When Pa-Pc>P1 or Pb-Pc>P1, P1 is the replacement limit of the safety filter element body, and an alarm prompts to replace the safety filter element. The present invention is provided with an alarm system. When the pressure difference between the pressure sensor Ⅰ13-A and the pressure sensor Ⅲ13-C or the pressure difference between the pressure sensor Ⅱ13-B and the pressure sensor Ⅲ13-C is greater than the replacement limit of the safety filter element body, the safety filter element needs to be replaced to improve the safety of the system.

[0030] When Pd<P2, Pd is the value of pressure sensor IV13-D, P2 is the set value of back-blowing compressed air pressure, electromagnetic clutch 6 and electromagnetic valve V5 are opened at the same time, otherwise they are closed at the same time, so as to keep the back-blowing gas source sufficient and stable. The present invention is provided with a safe use procedure of the gas cylinder. When the pressure of the gas cylinder is less than the back-blowing compressed air pressure, the gas cylinder needs to be inflated so that the system can operate normally.

[0031] An air filter for engineering machinery of the present invention is provided with a cyclone tube assembly. By adding a cyclone tube pre-filter structure, the initial filtration of heavy dust is strengthened and the dust accumulation speed of the back-blowing filter element is delayed; the secondary back-blowing filter element is connected with a rotating device, and the problem of poor back-blowing effect is solved by the rotating centrifugal force of the filter element; two sets of resistance heating devices and automatic control logic are also provided to adapt to the humid or cold equipment application environment conditions, and solve the problem that the filter element may fail and the back-blowing fails in the humid and low-temperature environment conditions; the automatic control system and method of the air filter for engineering machinery of the present invention are provided with two sets of air filter assemblies, sensors and electromagnetic valve components, and through the complete back-blowing system control protection program, the two air filters automatically switch modes, and the engine intake system is automatically monitored, managed and protected, so as to reduce the labor cost of equipment maintenance, realize the back-blowing operation of the filter element while the engine works normally, and improve the equipment attendance efficiency; in addition, the present invention adds an electromagnetic clutch structure of the engine air compressor to control the back-blowing compressed air pressure, and protects the back-blowing filter element while providing stable back-blowing compressed air.

[0032] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0033] In addition, those skilled in the art will understand that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments also means being within the scope of protection of the present invention and forming different embodiments. For example, in the above embodiments, those skilled in the art can use them in combination according to the known technical solutions and the technical problems to be solved by this application.

[0034] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this patent can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.

Claims

1. An air filter for engineering machinery, characterized in that: The invention comprises an air filter body (11-2), wherein the air filter body (11-2) comprises an upper shell and a lower shell, wherein the upper end of the upper shell is provided with an end cover (11-1), and the lower end of the upper shell is connected to the lower shell via a mounting flange (11-3), and the upper part of the lower shell is an air inlet (11-5), and a primary filtering structure is provided in the air filter body (11-2) at a position close to the air inlet (11-5), and the lower part of the lower shell is a conical ash collector of the primary filtering structure, and a dust exhaust valve (11-17) is provided at the lower end of the conical ash collector; an air outlet pipe (11-8) is also provided in the air filter body (11-2), and the air outlet pipe (11- A hollow cylindrical secondary back-blowing filter element (11-14) is provided on the upper part of the air filter body (11-8), the secondary back-blowing filter element (11-14) is connected to a motor for rotation, and a resistance heater I (11-10) is provided at the air inlet end of the air outlet pipe (11-8); a back-blowing air pipe (11-11) is provided inside the air outlet pipe (11-8), a plurality of air outlet holes are provided at the air outlet end of the back-blowing air pipe (11-11), and a resistance heater II (11-13) is wrapped around the portion of the back-blowing air pipe (11-11) where the air outlet holes are provided, and a plurality of back-blowing ash discharge ports (11-4) and ash discharge valves (11-18) used during back-blowing are provided outside the air filter body (11-2).

2. An air filter for engineering machinery according to claim 1, characterized in that: The air inlet (11-5) is a mesh structure arranged in a ring shape.

3. The air filter for engineering machinery according to claim 1, characterized in that: The primary filtering structure is a cyclone tube assembly (11-6), the cyclone tube assembly (11-6) is arranged around a circle in the lower shell, and the lower end of the conical ash collector is provided with a cyclone tube ash discharge port (11-7) connected to a dust discharge valve (11-17).

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

5. The air filter for engineering machinery according to claim 1, characterized in that: The air filter body (11-2) is evenly distributed with four back-blowing ash discharge ports (11-4) below the mounting flange (11-3); the ash discharge valve (11-18) is made of rubber; the structure of the ash discharge valve (11-18) is a normally closed trumpet shape; the ash discharge valve (11-18) is closed when the air filter is operating, and is opened during back-blowing.

6. An automatic control system using the air filter for construction machinery according to claim 1, characterized in that: The invention comprises two air filters, each of which is connected to a motor at its upper end, one of which is provided with a relative humidity sensor (16), the outlet pipe of each air filter being connected to a safety air filter (10) via a pressure sensor and a solenoid valve, the air inlet of the safety air filter (10) being provided with a temperature sensor (15), the outlet end of the safety air filter (10) being respectively connected to a turbocharger (14) and an air compressor (8), the air inlet end of the turbocharger (14) being provided with a pressure sensor, the air compressor (8) being connected to an electromagnetic clutch (6), the outlet end of the air compressor (8) being connected to a gas cylinder (7) via a solenoid valve and a one-way valve, the outlet end of the gas cylinder (7) being connected to a back-blowing air pipe of the air filter, and the air inlet end of the back-blowing air pipe of each air filter being provided with a one-way valve and a solenoid valve.

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

8. An automatic control system method for an air filter for construction machinery using claim 6, characterized in that: Adjust the working mode according to the temperature, humidity and pressure values, including: A. After the device is powered on for 2 seconds, the temperature sensor (15) collects the gas temperature of the air intake pipe of the safety air filter (10); if the temperature is ≤ -15°C, the resistance heater I (11-10) is turned on to assist the engine intake heating to improve the low-temperature starting performance, and then 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°C, 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 closed to perform back-blowing and drying operations; when the relative humidity drops below 60% and the temperature is greater than 0°C, 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 closed, and the solenoid valve III (3) and the solenoid valve IV (4) are turned on; C. After the engine (9) is started, when the solenoid valve III (3) is opened and the solenoid valve IV (4) is closed, the 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), P0 is the negative pressure limit of back-blowing 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 back-blowing, and motor Ⅰ (12-A) is turned on at the same time, rotating forward for 30 seconds and reverse for 30 seconds to back-blow 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 backwashing, and motor Ⅱ (12-B) is turned on at the same time, rotating forward for 30 seconds and reverse for 30 seconds. After the backwashing limit value is cycled for n times, an alarm is issued to prompt the replacement of the backwashing filter element.

9. An automatic control method for an air filter for engineering machinery as claimed in claim 8, characterized in that: When Pa-Pc>P1 or Pb-Pc>P1, P1 is the replacement limit of the safety filter element, and an alarm prompts to replace the safety filter element.

10. An automatic control method for an air filter for engineering machinery as claimed in claim 8, characterized in that: When Pd < P2, Pd is the value of pressure sensor IV (13-D), P2 is the set value of back-blowing compressed air pressure, the electromagnetic clutch (6) and the electromagnetic valve V (5) are opened at the same time, otherwise they are closed at the same time, so as to keep the back-blowing air source sufficient and stable.

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