Improved electromagnetic pilot valve for mining

Abstract

This invention provides an improved electromagnetic pilot valve for mining applications, relating to the field of electromagnetic pilot valves. This improved electromagnetic pilot valve for mining includes a directional valve body and an electromagnetic pilot assembly. The electromagnetic pilot assembly includes an electromagnetic pilot unit, a manual operation unit, and a multi-stage protection unit. The electromagnetic pilot unit is mounted on the directional valve body and is used to control the opening and closing of the pilot orifice. The multi-stage protection unit is also mounted on the directional valve body, and both the electromagnetic pilot unit and the manual operation unit are located within the multi-stage protection unit. This improved electromagnetic pilot valve for mining, by setting up a multi-stage protection unit, protects the electromagnet and valve stem from a primary, secondary, and tertiary cover. Therefore, even in the harsh environment of coal mines, dust is less likely to enter the valve stem area. The manual operation lever is also protected by a tertiary cover and a protective plate, ensuring smooth operation and preventing jamming. Thus, compared to existing technologies, it simultaneously protects both the manual operation unit and the electromagnetic pilot unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electromagnetic pilot valve, in particular to a mine improved electromagnetic pilot valve. BACKGROUND

[0002] The electromagnetic pilot valve is also called pilot electromagnetic valve. When power is on, the valve rod is lifted by electromagnetic force, and the pilot valve port is opened. At this time, the upper cavity of the electromagnetic valve is relieved through the pilot hole, and a low-high pressure difference is formed around the main valve core. Under the action of the pressure difference, the fluid pressure pushes the main valve core to move upward to open the main valve port. When power is off, the valve rod is reset under the action of spring force and gravity of the main valve core, the pilot hole is closed, and the main valve core moves downward to close the main valve port. The pressure in the upper cavity of the electromagnetic valve rises, and the fluid pressure pressurizes the main valve core, so that the sealing is better.

[0003] When the mine electromagnetic pilot valve is applied in coal mines, metal mines and other harsh environments, it often faces the following typical problems. Due to the harsh environment, the valve core is prone to jamming and the pilot hole is prone to blockage in high-dust mine environment, affecting the response speed (such as the action time is delayed from milliseconds to seconds). Moisture corrosion: when the humidity is > 90%, the coil insulation level is insufficient (such as below H level) and is prone to rust, and the service life is shortened by more than 50%. The electromagnetic pilot valve often appears damaged or often needs emergency manual control in coal mines. The manual control structure is complex, the environmental adaptability is poor, and dust blockage is prone to occur, so the operation cannot be timely in emergency state, and the risk level will increase.

[0004] Publication (announcement) No. CN106090397A provides a mine electromagnetic pilot valve manual mechanism, a push rod is arranged in the electromagnetic pilot valve, a fixed shell is arranged on the electromagnetic pilot valve, a top rod is arranged in the fixed shell, a spring is arranged between the top rod and the fixed shell, the spring is sleeved on the top rod, the fixed shell is provided with a dust cover, the top of the top rod is provided with a connecting structure, the top of the dust cover is provided with a through hole, the connecting structure passes through the through hole, and the dust cover and the connecting mechanism are sealingly connected, the fixed shell is hingedly connected with a pressing handle, the bottom of the pressing handle is provided with a pressure head, and the pressure head and the connecting structure are correspondingly arranged.

[0005] In the mine electromagnetic pilot valve manual mechanism, the pressing handle operation form is adopted, which is convenient and fast. At the same time, the dust cover is extruded together with the top rod cap and the top rod, and then the pressure ring is pressed into the fixed shell. This structure form has excellent performance in waterproof and dustproof, and greatly improves the service life.

[0006] In the above scheme, only the fixed shell is provided with a dust cover corresponding to the ejector rod, and the rest of the ejector rod is not treated for dust and water resistance. When the handle is pressed, the dust cover is pressed completely. Because the humidity in the mine is high, and some liquids have strong corrosiveness to rubber, the service life of the dust cover is relatively low. If local cracks occur, the valve rod may not be pressed in an emergency. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application provides an improved electromagnetic pilot valve for mining, which solves the problems in the above background art.

[0008] To achieve the above object, the present application is implemented by the following technical scheme: an improved electromagnetic pilot valve for mining, comprising a reversing valve body and an electromagnetic pilot assembly, the electromagnetic pilot assembly comprising an electromagnetic pilot unit, a manual operation unit and a multi-stage protection unit; the electromagnetic pilot unit is installed on the reversing valve body and is used to control the opening and closing of the pilot hole; the multi-stage protection unit is installed on the reversing valve body, and the electromagnetic pilot unit and the manual operation unit are both inside the multi-stage protection unit; the manual operation unit is used to manually control the opening and closing of the pilot hole by the electromagnetic pilot unit; and the multi-stage protection unit is used to protect the electromagnetic pilot unit.

[0009] Preferably, the electromagnetic pilot unit comprises an electromagnet, a valve rod, a closure and auxiliary ejector rods, the closure is connected with the reversing valve body, the valve rod passes through the closure and is in sealed sliding connection with the closure, and the auxiliary ejector rods are provided in multiple numbers and are all fixed around the outside of the valve rod; the electromagnet is suspended above the valve rod; and the electromagnet can attract the valve rod to move upward.

[0010] Preferably, the multi-stage protection unit comprises a primary cover, the primary cover is fixed and sealed above the closure, the upper end of the valve rod and the lower end of the electromagnet are both in a cavity between the primary cover and the closure, the electromagnet is fixed and sealed with the upper end of the primary cover, and the upper ends of the auxiliary ejector rods all pass through the primary cover and are in sealed sliding connection with the primary cover.

[0011] It also comprises a secondary cover, which covers the outside of the primary cover; the upper and lower ends of the secondary cover are both in sealed connection with the primary cover by using elastic sealing covers; and the upper ends of the auxiliary ejector rods are fixed with the inner top wall of the secondary cover.

[0012] It also comprises a tertiary cover, which covers the outside of the secondary cover; the lower end of the tertiary cover is fixed and sealed with the closure; and the upper end of the tertiary cover is fixed and sealed with the primary cover.

[0013] Preferably, the primary cover is fixedly provided with a dust ring at the positions corresponding to the positions where the auxiliary ejector rods pass through.

[0014] Preferably, the outer wall of the tertiary cover is provided with two detachable protection plates, the protection plates are magnetically attracted in the outer wall of the tertiary cover and are flush with the outer wall of the tertiary cover, and the bottom ends of the outer walls of the protection plates are both provided with friction grooves.

[0015] Preferably, the manual operation unit comprises a toothed plate, a gear and a manual operation rod, the toothed plate and the gear are both installed on the bottom end side of the primary cover, the toothed plate is slidably connected to the gear, the gear is rotatably connected to the toothed plate, the lower end of the manual operation rod is fixed to the gear spindle for controlling the rotation of the gear, and the outer wall of the secondary cover is fixedly installed with a pin shaft corresponding to the upper end of the toothed plate, the toothed plate can push the pin shaft to lift the secondary cover when moving upward.

[0016] Preferably, the outer wall of the secondary cover is installed with an elastic power-off trigger corresponding to the manual operation rod, which can extend to push the manual operation rod after power-off.

[0017] Preferably, the manual operation rod is provided with a protection plate, and the elastic power-off trigger can push the manual operation rod to open the protection plate.

[0018] Preferably, the reversing valve body comprises a valve body and a pilot cavity, a pilot hole is arranged at the bottom of the pilot cavity, a closure is sealingly fixed above the pilot cavity, a cavity is formed between the closure and the pilot cavity, the lower end of the valve rod is located in the closure and the pilot cavity, and the valve rod is connected to the bottom of the pilot cavity by a spring, so that the bottom of the valve rod can be tightly attached to the pilot hole for sealing the pilot hole when the valve rod is not subjected to the attraction of the electromagnet.

[0019] Compared with the prior art, the present application has the following advantages:

[0020] 1. The improved mine electromagnetic pilot valve is provided with multiple protection units, and the electromagnet and the valve rod are jointly protected by the primary cover, the secondary cover and the tertiary cover, so that there are multiple protection layers, the position of the valve rod is not easy to enter dust in the harsh environment of the coal mine, even if emergency manual operation is needed, the manual operation rod is protected by the tertiary cover and the protection plate, is not affected by the coal ash, and is smoothly operated and not easy to be stuck, so that the effect of protecting the manual operation unit and the electromagnetic pilot unit is achieved.

[0021] 2. The improved mine electromagnetic pilot valve is provided with a manual operation unit, the manual operation rod is in a hidden state in the normal running state, the protection plate protects the manual operation rod to prevent the position of the manual operation rod from entering the coal ash, and the manual operation rod can move out of the tertiary cover in the case of power-off, so that rapid operation can be realized, and if the prior art wants to protect the manual operation rod, the manual operation rod is not easy to operate, and the mechanical unit can be quickly operated and well protected. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structural schematic view of the present application;

[0023] Figure 2 It is a structural sectional view of the present application;

[0024] Figure 3 This is a schematic diagram of the structure of the electromagnetic pilot component of the present invention;

[0025] Figure 4 This is a schematic diagram of the electromagnetic pilot unit of the present invention;

[0026] Figure 5 This is a diagram showing the internal structure of the electromagnetic pilot unit of the present invention;

[0027] Figure 6 For the present invention Figure 5 Enlarged view of the structure at point A in the middle;

[0028] Figure 7 For the present invention Figure 5 Enlarged view of the structure at point B;

[0029] Figure 8 This is a schematic diagram of the structure of the primary and secondary covers of the present invention;

[0030] Figure 9 This is a schematic diagram of the structure of the primary cover and electromagnet of the present invention;

[0031] Figure 10 This is a schematic diagram of the electromagnet and valve stem of the present invention.

[0032] In the picture:

[0033] 1. Reversing valve body;

[0034] 101. Valve body; 102. Pilot chamber;

[0035] 2. Electromagnetic pilot assembly;

[0036] 201. Electromagnetic pilot unit;

[0037] 2011, Electromagnet; 2012, Valve stem; 2013, Sealer; 2014, Auxiliary push rod;

[0038] 202. Manual operation unit;

[0039] 2021, Gear plate; 2022, Gear; 2023, Manual operating lever; 2024, Pin;

[0040] 203. Multi-level protection unit;

[0041] 2031, Level 1 cover; 2032, Level 2 cover; 2033, Elastic sealing cover; 2034, Level 3 cover; 2035, Dustproof ring; 2036, Protective plate; 2037, Friction groove; 2038, Elastic power-off trigger. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0043] It should be noted that all directional indications in the embodiments of this application are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0044] In this application, unless otherwise expressly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0045] Furthermore, the use of terms such as "first" and "second" in this application is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed in this application.

[0046] like Figures 1-10 As shown, an improved electromagnetic pilot valve for mining includes a directional valve body 1 and an electromagnetic pilot assembly 2. The electromagnetic pilot assembly 2 includes an electromagnetic pilot unit 201, a manual operation unit 202, and a multi-stage protection unit 203. The electromagnetic pilot unit 201 is installed on the directional valve body 1 and is used to control the opening and closing of the pilot orifice. The multi-stage protection unit 203 is installed on the directional valve body 1. Both the electromagnetic pilot unit 201 and the manual operation unit 202 are located inside the multi-stage protection unit 203. The manual operation unit 202 is used to manually control the opening and closing of the pilot orifice by the electromagnetic pilot unit 201. The multi-stage protection unit 203 is used to seal and protect the electromagnetic pilot unit 201.

[0047] The electromagnetic pilot valve is divided into a main valve part and a pilot control part, the main valve part is a reversing valve body 1, and the pilot control part is an electromagnetic pilot assembly 2, the main valve part includes a main valve core: a large-size valve core driven by a pilot pressure, directly controlling a main oil way flow. A main valve spring: used for main valve reset or keeping a default state always open / always closed. A damping hole / throttle hole: balancing pressure, avoiding shock caused by too fast main valve action.

[0048] The main valve core of the reversing valve body 1 adopts a spool valve type structure, a taper surface seal is used for a high-pressure overflow valve or a one-way valve, and the sealing property is good. The operation principle is that the pilot valve sets a pressure, when the system pressure exceeds the set value, the pilot valve is opened, oil flows through the damping hole, and the pressure difference between the two ends of the main valve core makes the main valve core open and release pressure.

[0049] The manual control device of the current electromagnetic pilot valve generally directly drives the internal electromagnetic valve, direct driving will inevitably cause mechanical connection, and the mechanical connection is easy to enter coal powder and moisture when running in a coal mine, therefore, in the case of long-term non-use in harsh conditions, the manual control device is likely to be stuck or difficult to control.

[0050] In an optional embodiment, the electromagnetic pilot unit 201 includes an electromagnet 2011, a valve rod 2012, a closure 2013 and auxiliary jacks 2014, the closure 2013 is connected with the reversing valve body 1, the valve rod 2012 passes through the closure 2013 and is in sealed sliding connection therewith, the auxiliary jacks 2014 are provided in plurality and are all fixed around the outside of the valve rod 2012, and the electromagnet 2011 is suspended above the valve rod 2012 and can attract the valve rod 2012 to move upward.

[0051] In this embodiment, the closure 2013 can replace the structure near the pilot hole on the traditional main valve, the closure 2013 can be detached from the reversing valve body 1 and is suitable for modular use in the later stage, when the closure 2013 is installed on the main valve, mainly forming a cavity for pilot pressure relief.

[0052] In an optional embodiment, the multi-stage protection unit 203 includes a primary cover 2031, the primary cover 2031 is fixed and sealed above the closure 2013, the upper end of the valve rod 2012 and the lower end of the electromagnet 2011 are both in the cavity between the primary cover 2031 and the closure 2013, the electromagnet 2011 is fixed and sealed with the upper end of the primary cover 2031, and the upper ends of the auxiliary jacks 2014 all pass through the primary cover 2031 and are in sealed sliding connection therewith;

[0053] Further including a secondary cover 2032, the secondary cover 2032 is covered outside the primary cover 2031, the upper and lower ends of the secondary cover 2032 are both in sealed connection with the primary cover 2031 through elastic sealing covers 2033, and the upper ends of the auxiliary jacks 2014 are fixed with the inner top wall of the secondary cover 2032;

[0054] Still further comprising a third cover 2034, the cover is outside the second cover 2032, the lower end of the third cover 2034 is sealed and fixed with the closure 2013, and the upper end of the third cover 2034 is sealed and fixed with the first cover 2031.

[0055] In this embodiment, the first cover 2031 is responsible for directly protecting the valve rod 2012, and the main up-and-down movement of the valve rod 2012 is always within the first cover 2031. The auxiliary ejector rod 2014 serves as a component that moves synchronously with the valve rod 2012, and the upper end of the auxiliary ejector rod 2014 moves outside the first cover 2031.

[0056] The second cover 2032 is concentrically arranged with the first cover 2031. Because the elastic sealing cover 2033 is arranged, the second cover 2032 is separated from the outside no matter how it moves up and down, and the air, dust and moisture outside cannot enter the second cover 2032.

[0057] The third cover 2034 is concentrically arranged outside the second cover 2032, so the elastic sealing cover 2033 connected to the second cover 2032 is basically not affected by the corrosive gas and corrosive moisture from the outside, and the valve rod 2012 has three more layers of protection than the prior art.

[0058] In an optional embodiment, the first cover 2031 is fixedly installed with a dust ring 2035 corresponding to the position through which the auxiliary ejector rod 2014 passes.

[0059] In this embodiment, the dust ring 2035 can isolate dust in the sliding component, and the inside of the dust ring 2035 is further provided with an oil scraping ring, which mainly plays a lubricating and dust isolating effect.

[0060] In an optional embodiment, the outer wall of the third cover 2034 is provided with two detachable protective plates 2036, the protective plates 2036 are magnetically attracted to the outer wall of the third cover 2034 and flush with the outer wall thereof, and the bottom end of the outer wall of the protective plates 2036 is provided with a friction groove 2037.

[0061] In this embodiment, the outer wall of the third cover 2034 is provided with a through groove with the same shape as the protective plate 2036, the rear end of the through groove is provided with a magnetic boss, the protective plate 2036 is attracted by the boss when placed inside the through groove, and the protective plate 2036 is flush with the outer wall of the third cover 2034 after being placed inside the through groove. The friction groove 2037 on the protective plate 2036 can realize the effect of manually removing and installing the protective plate 2036.

[0062] In an alternative embodiment, the manual operation unit 202 comprises a toothed plate 2021, a gear 2022 and a manual operation lever 2023, the toothed plate 2021 and the gear 2022 are both installed on the bottom end side of the primary cover 2031, the toothed plate 2021 is slidingly connected to the primary cover 2031, the gear 2022 is rotatably connected to the primary cover 2031, the gear 2022 is engaged with the toothed plate 2021, the lower end of the manual operation lever 2023 is fixed to the main shaft of the gear 2022 for controlling the rotation of the gear 2022, the outer wall of the secondary cover 2032 is fixedly installed with a pin shaft 2024 corresponding to the upper end of the toothed plate 2021, the pin shaft 2024 can be lifted when the toothed plate 2021 moves upward.

[0063] In the embodiment, the toothed plate 2021 is externally sleeved with a sliding sleeve, the sliding sleeve is connected to the bottom side of the primary cover 2031, the toothed plate 2021 and the sliding sleeve are oiled, the upper end of the toothed plate 2021 is provided with a groove, the groove corresponds to the pin shaft 2024, when the toothed plate 2021 rises, the pin shaft 2024 can enter the groove, when the manual operation lever 2023 is upward, there is a gap distance between the toothed plate 2021 and the pin shaft 2024, the gear 2022 has resistance when rotating, which can make the manual operation lever 2023 hover at a fixed position.

[0064] In an alternative embodiment, the outer wall of the secondary cover 2032 is provided with an elastic power-off trigger 2038 corresponding to the manual operation lever 2033, which can be extended to lift the manual operation lever 2023 after power-off.

[0065] In the embodiment, the elastic power-off trigger 2038 stores elastic potential energy by using a spring, releases energy when power-off, drives mechanical components to act, and the action is to extend the inner core, which can lift the manual operation lever 2023 when extending.

[0066] In an alternative embodiment, the manual operation lever 2023 corresponds to the protection plate 2036, when the elastic power-off trigger 2038 lifts the manual operation lever 2023, the manual operation lever 2023 can lift the protection plate 2036.

[0067] In the embodiment, the manual operation lever 2023 is attached to the protection plate 2036, when the manual operation lever 2023 moves slightly by a certain angle, the protection plate 2036 is opened.

[0068] In an alternative embodiment, the reversing valve body 1 comprises a valve body 101 and a pilot cavity 102, a pilot hole is provided at the bottom of the pilot cavity 102, a closure 2013 is sealed and fixed above the pilot cavity 102, an air cavity is formed between the closure 2013 and the pilot cavity 102, the lower end of the valve rod 2012 is in the closure 2013 and the pilot cavity 102, the valve rod 2012 is connected with the bottom of the pilot cavity 102 by a spring, when the valve rod 2012 is not affected by the suction force of the electromagnet 2011, the spring can make the bottom of the valve rod 2012 tightly adhere to the pilot hole for sealing the pilot hole.

[0069] In this embodiment, the pilot cavity 102 and the closure 2013 can form a modular assembly, which is convenient to disassemble from the main valve.

[0070] Working principle

[0071] Normal use: when the valve needs to be opened, the electromagnet 2011 is energized to attract the valve rod 2012 to move upward, at this time the pilot hole is opened, the pressure above the main valve core is less than the pressure below it, so the main valve core will gradually open, when the valve is closed, the electromagnet 2011 is de-energized, under the influence of the spring, the valve rod 2012 will move downward to close the pilot hole, at this time the pressure above the main valve core begins to be greater than the pressure below it, so the main valve core will gradually close, under the influence of the pressure, the main valve core will gradually achieve complete sealing;

[0072] Power off: after power off, the core shaft of the elastic power-off trigger 2038 will be affected by the internal spring to stretch from inside to outside, thereby changing the length, so as to push the manual operating rod 2023, the manual operating rod 2023 will open outward when it is pressed, at this time the movement of the tooth plate 2021 has not contacted the pin shaft 2024, until the manual operating rod 2023 opens to push the protection plate 2036 from the third cover 2034, at this time the manual operating rod 2023 is exposed outside the third cover 2034;

[0073] Manual operation: manually press the two manual operating rods 2023, at this time the gear 2022 will engage the tooth plate 2021 to move upward, the tooth plate 2021 gradually pushes the pin shaft 2024, then the pin shaft 2024 moves upward with the secondary cover 2032, when the secondary cover 2032 moves upward, it drives the valve rod 2012 to move upward through the auxiliary push rod 2014, thereby slowly opening the pilot hole, after the pilot hole is opened, the function in the above normal use can be realized.

[0074] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the specification.

[0075] In addition, the technical solutions among various embodiments can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, nor is it within the protection scope required by the present application.

[0076] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A mine improved electromagnetic pilot valve, comprising a reversing valve body (1) and an electromagnetic pilot assembly (2), characterized in that: The electromagnetic pilot assembly (2) comprises an electromagnetic pilot unit (201), a manual operation unit (202) and a multi-stage protection unit (203); the electromagnetic pilot unit (201) is installed on the reversing valve body (1) and used for controlling the opening and closing of the pilot hole; the multi-stage protection unit (203) is installed on the reversing valve body (1); the electromagnetic pilot unit (201) and the manual operation unit (202) are both inside the multi-stage protection unit (203); the manual operation unit (202) is used for manually controlling the opening and closing of the pilot hole by the electromagnetic pilot unit (201); and the multi-stage protection unit (203) is used for sealingly protecting the electromagnetic pilot unit (201); The electromagnetic pilot unit (201) comprises an electromagnet (2011), a valve rod (2012), a sealer (2013) and auxiliary jacks (2014); the sealer (2013) is connected with the reversing valve body (1); the valve rod (2012) passes through the sealer (2013) and is sealingly and slidably connected with the sealer (2013); the auxiliary jacks (2014) are provided in plurality and are all fixed around the outside of the valve rod (2012); the electromagnet (2011) is suspended above the valve rod (2012); and the electromagnet (2011) can attract the valve rod (2012) to move upward; The multi-stage protection unit (203) comprises a first cover (2031); the first cover (2031) is fixed and sealed above the sealer (2013); the upper end of the valve rod (2012) and the lower end of the electromagnet (2011) are both in a cavity between the first cover (2031) and the sealer (2013); the electromagnet (2011) is sealingly fixed with the upper end of the first cover (2031); and the upper ends of the auxiliary jacks (2014) all pass through the first cover (2031) and are sealingly and slidably connected with the first cover (2031); The multi-stage protection unit (203) further comprises a second cover (2032) which is covered outside the first cover (2031); the upper and lower ends of the second cover (2032) are both sealingly connected with the first cover (2031) by elastic sealing covers (2033); and the upper ends of the auxiliary jacks (2014) are fixed with the inner top wall of the second cover (2032); The multi-stage protection unit (203) further comprises a third cover (2034) which is covered outside the second cover (2032); the lower end of the third cover (2034) is sealingly fixed with the sealer (2013); and the upper end of the third cover (2034) is sealingly fixed with the first cover (2031). The manual operation unit (202) comprises a toothed plate (2021), a gear (2022) and a manual operation rod (2023), the toothed plate (2021) and the gear (2022) are both installed on the bottom end side of the primary cover (2031), the toothed plate (2021) is slidably connected with the primary cover (2031) up and down, the gear (2022) is rotatably connected with the primary cover (2031), the gear (2022) is engaged with the toothed plate (2021), the lower end of the manual operation rod (2023) is fixed with the main shaft of the gear (2022), for controlling the rotation of the gear (2022), the outer wall of the secondary cover (2032) is fixedly installed with a pin shaft (2024) at the position corresponding to the upper end of the toothed plate (2021), when the toothed plate (2021) moves upwards, the pin shaft (2024) can be pushed to make the secondary cover (2032) lift up.

2. The improved electromagnetic pilot valve for mine use according to claim 1, characterized in that: The primary cover (2031) is fixedly installed with a dust ring (2035) at the position corresponding to the auxiliary ejector rod (2014).

3. The improved electromagnetic pilot valve for mine use according to claim 2, characterized in that: The outer wall of the tertiary cover (2034) is provided with two detachable protection plates (2036), the protection plates (2036) are magnetically attracted to the outer wall of the tertiary cover (2034) and are flush with the outer wall, and the bottom end outer wall of the protection plate (2036) is provided with a friction groove (2037).

4. The improved electromagnetic pilot valve for mine use according to claim 3, characterized in that: The outer wall of the secondary cover (2032) is installed with an elastic power-off trigger (2038) corresponding to the manual operation rod (2023), which can push the manual operation rod (2023) after power-off.

5. The improved electromagnetic pilot valve for mine use according to claim 4, characterized in that: The manual operation rod (2023) corresponds to the protection plate (2036), when the elastic power-off trigger (2038) pushes the manual operation rod (2023), the manual operation rod (2023) can push open the protection plate (2036).

6. The improved electromagnetic pilot valve for mine use according to claim 1, characterized in that: The reversing valve body (1) comprises a valve body (101) and a pilot cavity (102), a pilot hole is arranged at the bottom of the pilot cavity (102), a closure (2013) is sealingly fixed above the pilot cavity (102), a cavity is formed between the closure (2013) and the pilot cavity (102), the lower end of a valve rod (2012) is in the closure (2013) and the pilot cavity (102), the valve rod (2012) is connected with the bottom of the pilot cavity (102) by a spring, when the valve rod (2012) is not attracted by an electromagnet (2011), the spring can make the bottom of the valve rod (2012) tightly adhere to the pilot hole, for sealing the pilot hole.

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