High-efficiency and high-power electromagnetic drive head

Abstract

The present invention relates to a high-efficiency, high-power electromagnetic drive head, comprising a housing and a coil, a moving iron core, a static iron core, and a magnetic isolation tube arranged vertically coaxially with the housing. The static iron core comprises a first static iron core and a second static iron core. The main body of the first static iron core is tubular and sleeved on the outer side of the upper portion of the magnetic isolation tube, with its lower end lower than the lower end of the second static iron core. The second static iron core is fixedly mounted in the upper portion of the magnetic isolation tube. The moving iron core is located below the second static iron core and is slidably connected to the magnetic isolation tube. Under normal conditions, a first working air gap is left between the top surface of the moving iron core and the lower end of the first static iron core, and a second working air gap is left between the top surface and the lower end of the second static iron core, and the second working air gap is larger than the first working air gap. This electromagnetic drive head can significantly improve starting power / maximum power output.

Description

Technical Field

[0001] The present invention relates to a high-efficiency and high-power electromagnetic driving head, which can be mainly used as an electromagnetic prime mover for driving high-power electromagnetic valves and other mechanisms / devices. Background Art

[0002] The existing electromagnetic drive device (or electromagnetic drive head, or electromagnetic head) for driving mechanisms / devices such as solenoid valves is usually mainly composed of a coil, a moving iron core and a static iron core. A magnetic isolation tube is provided in the shell of the electromagnetic head. The coil and the coil frame for installing and fixing the coil are arranged in the shell space outside the magnetic isolation tube. A junction box is installed on the outside of the shell. The wiring terminal of the coil is arranged in the junction box, and the external power supply is connected through the junction box. The static iron core and the moving iron core are arranged in the magnetic isolation tube, wherein the static iron core is fixedly installed on the upper part of the magnetic isolation tube, and the moving iron core is located below the static iron core, slidingly cooperates with the inner wall of the magnetic isolation tube, and can move up and down in the magnetic isolation tube. The lower end of the magnetic isolation tube is installed on the magnetic isolation tube seat. The magnetic isolation tube base is provided with a connection structure, such as a flange, for connecting to other devices. During use, the solenoid is fixedly mounted on the valve body or other device to be driven via the magnetic isolation tube base. The lower end of the moving iron core is connected to the movable part / input component of the valve body or other driven device (e.g., the valve stem or valve disc of a solenoid valve). When the coil is energized, the static and moving iron cores attract each other, and the moving iron core drives the valve stem or other movable part upward to an upper limit position (e.g., contacting the lower end of the static iron core). When the coil is de-energized, the moving iron core moves downward under the action of a return coil spring and / or gravity to a lower limit position (usually defined by the valve body or other driven device). This prior art has a drawback because, during startup, the distance between the static and moving iron cores (commonly referred to as the working air gap) is at its maximum, minimizing power. However, the power demand of the driven device is often at its maximum at this time due to factors such as static friction. Therefore, to effectively drive the driven device, the power of the solenoid at its minimum power must meet the maximum power demand of the driven device. This significantly increases the size and material cost of the solenoid, and also results in unnecessary energy consumption. Summary of the Invention

[0003] The purpose of the present invention is to improve the driving force of an electromagnetic drive head when starting.

[0004] The technical solution of the present invention is: a high-efficiency and high-power electromagnetic drive head, provided with a shell and a coil, a moving iron core, a static iron core and a magnetic isolation tube arranged vertically coaxially with the shell, the coil, the moving iron core and the static iron core are installed in the shell, the coil is wrapped around the outside of the magnetic isolation tube and is fixedly installed on the coil frame, the magnetic isolation tube passes through the magnetic isolation tube through-hole on the bottom plate of the shell, its top end is fixedly connected to the top plate of the shell, and the bottom end is located outside the shell, the static iron core includes a first static iron core and a second static iron core, the main body of the first static iron core is tubular, sleeved on the outside of the upper part of the magnetic isolation tube, located between the coil and the magnetic isolation tube, its lower end is lower than the lower end of the second static iron core, the second static iron core and the moving iron core are arranged in the magnetic isolation tube, the second static iron core is fixedly installed in the upper part of the magnetic isolation tube, the moving iron core is located below the second static iron core, and slides with the inner wall of the magnetic isolation tube. Under normal conditions, a first working air gap is left between its top surface and the lower end of the first static iron core.

[0005] Preferably, a circular disk-shaped structure is provided on the top of the first static iron core, and the top disk-shaped structure of the first static iron core extends radially outward from the top of the main body of the first static iron core, and its upper surface is in contact with the inner surface of the top plate of the shell.

[0006] Preferably, a magnetic conductive sleeve is provided in the shell, and the magnetic conductive sleeve is located at the connection position between the shell bottom plate and the magnetic isolation tube. The main part of the magnetic conductive sleeve is in the shape of a sleeve and is sleeved on the magnetic isolation tube. The top height is lower than the top surface height of the moving iron core under normal conditions, and a circular disk-shaped structure is provided at the bottom. The bottom disk-shaped structure of the magnetic conductive sleeve extends radially outward from the bottom end of the main part of the magnetic conductive sleeve, and its lower surface is in contact with the inner surface of the bottom plate of the shell.

[0007] Preferably, the housing is composed of a main housing with an open bottom and a housing cover covering the open bottom of the main housing.

[0008] Preferably, a vertical screw is provided on the top of the second static iron core, and the vertical screw passes through the screw hole in the center of the top plate of the shell. A fastening nut is screwed on the outer side of the vertical screw, and the second static iron core is fastened to the shell through the fastening nut.

[0009] Preferably, a junction box is installed on the side wall of the housing, and a connection terminal for connecting an external power cable is provided in the junction box. The connection terminal is connected to the coil via a wire passing through the side wall of the housing.

[0010] Preferably, the vertical dimension of the first working air gap is 2-3 mm under normal conditions.

[0011] Preferably, by setting the cross-section of the first static iron core, the cross-section of the second static iron core and the vertical dimensions of the first working air gap and the second working air gap under normal conditions, the suction force between the moving iron core and the static iron core during startup is 1.5-2.5 times the suction force between the moving iron core and the static iron core when the top surface of the moving iron core and the lower end of the first static iron core are at the same height.

[0012] Preferably, a coil spring disengagement device is provided between the movable iron core and the second static iron core, which tends to push the movable iron core and the second static iron core apart when the movable iron core and the second static iron core are in an engaged state.

[0013] Preferably, the coil spring disengagement device includes a coil spring and a disengagement pin, the moving iron core is provided with a spring mounting hole located on its axis, the disengagement pin is in the shape of a cylindrical step that is thin at the top and thick at the bottom, the top of the spring mounting hole is in the shape of a necking corresponding to the disengagement pin, the inner diameter of the necking is slightly larger than the outer diameter of the upper part of the disengagement pin and smaller than the outer diameter of the lower part of the disengagement pin, the coil spring is located in the spring mounting hole and is in a pre-compressed state, its top is pressed against the bottom of the disengagement pin, and its bottom is pressed against the bottom of the spring mounting hole.

[0014] The beneficial effects of the present invention are as follows: since the first static iron core and the second static iron core are provided, and the first working air gap between the first static iron core and the moving iron core is significantly smaller than the second working air gap between the second static iron core and the moving iron core at startup, the suction force between the first static iron core and the moving iron core will be significantly greater than the suction force of the second static iron core (equivalent to the static iron core under the prior art), thereby significantly increasing the power at startup, and thus, compared with the prior art, a smaller electromagnetic head can drive a larger load. At the same time, when the moving iron core and the second static iron core are attracted, the force between the first static iron core and the moving iron core is very small and can basically be ignored. From the entire upward movement process of the moving iron core, the amplitude of the power change is also significantly reduced, which is conducive to reducing the speed of the moving iron core. The impact force when it is attracted to the second static iron core prolongs the service life and is also beneficial to reduce unnecessary power consumption; since the first static iron core is tubularly sleeved on the outside of the second static iron core, the power generated by the first static iron core (the suction force between it and the moving iron core) and the power generated by the second static iron core are evenly distributed in the circumferential direction, and the effects are consistent, both vertically upward, and the circumferential balance of the magnetic field is not destroyed due to the setting of the two static iron cores. The cross-sectional size ratio of the two static iron cores can be appropriately selected according to the magnetic field characteristics, the magnetic flux of the two static iron cores can be reasonably distributed according to actual needs, and the working air gap of the first static iron core at startup can be reasonably set, thereby optimizing the power change curve of the electromagnetic head during the entire attraction process and further improving the power characteristics.

[0015] By improving the static iron core, the present invention can obtain greater starting power / maximum power output while keeping other parts basically unchanged, reduce the variation range of power output during the operation, improve the effective utilization rate of power, meet higher load driving requirements, help reduce the volume of the electromagnetic head, reduce manufacturing costs, reduce space occupancy, reduce unnecessary energy waste, improve energy efficiency, and adapt to various corresponding electromagnetic drive occasions, especially high-power load equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the present invention in a power-off / non-operating state;

[0017] Figure 2 It is a schematic diagram of the present invention when it is initially started;

[0018] Figure 3 This is a schematic diagram of the present invention after the top of the moving iron core passes over the lower end of the first static iron core;

[0019] Figure 4 It is a schematic diagram of the present invention when the moving iron core and the second static iron core are in the attracted state. DETAILED DESCRIPTION

[0020] See also Figure 1-4 The present invention provides a high-efficiency and high-power electromagnetic drive head, which is provided with a shell 30 and a coil (or excitation coil) 26, a moving iron core 23, a static iron core and a magnetic isolation tube 38 arranged vertically coaxially with the shell (the central axis is located on the same vertical straight line). The coil, moving iron core and static iron core are installed in the shell, and the coil is wrapped around the outside of the magnetic isolation tube and fixedly installed on the coil frame 36. The magnetic isolation tube passes through the magnetic isolation tube through-hole on the bottom plate of the shell, and its top end is fixedly connected to the top plate of the shell, and the bottom end is located outside the shell. It can usually be fixedly installed on the magnetic isolation tube seat 39, or installed on other fixing parts. In this case, the other fixing parts used to install the magnetic isolation tube can be regarded as magnetic isolation tube seats. The specific installation method can be based on actual needs, for example, the corresponding connection structure of the device driven by the electromagnetic head.

[0021] There are two static iron cores, including a first static iron core 21 and a second static iron core 22. The main part of the first static iron core is tubular and is sleeved on the outside of the upper part of the magnetic isolation tube, located between the coil and the magnetic isolation tube, and its lower end is lower than the lower end of the second static iron core. The second static iron core and the moving iron core are usually cylindrical and are arranged in the magnetic isolation tube, wherein the second static iron core is fixedly installed in the upper part of the magnetic isolation tube, and the moving iron core is located below the second static iron core and slides with the inner wall of the magnetic isolation tube. A first working air gap H1 is left between its top surface and the lower end of the first static iron core under normal conditions (in the non-powered state, or when the moving iron core is in a low position, that is, at the lower limit of its vertical movement range). Therefore, it is inevitable that a second working gap H2 is left between the top surface of the moving iron core and the lower end of the second static iron core under normal conditions, and the vertical dimension of the second working gap is larger than the vertical dimension of the first working gap.

[0022] The magnetic isolation tube seat may be provided with a central through hole, and the lower end of the magnetic isolation tube is inserted into and fixed (for example, welded) on the central through hole of the magnetic isolation tube seat, thereby achieving fixed installation of the magnetic isolation tube on the magnetic isolation tube seat.

[0023] The bottom of the magnetic isolation tube seat may be provided with a flange structure 40 for installation on other devices (for example, the valve body of a solenoid valve). Other forms of connection structures may also be provided for installation on other devices according to actual needs.

[0024] The bottom surface of the magnetic isolation tube seat may be provided with a vertical annular flange, a groove or a tongue and groove, etc. for fastening with other devices (for example, a socket on other devices).

[0025] The top of the first static iron core can be provided with (or is provided with) a circular disk-shaped structure. The top disk-shaped structure of the first static iron core extends radially outward from the top of the main part of the first static iron core, and its upper surface is in contact with the inner surface (lower surface) of the top plate of the shell to facilitate magnetic conduction and magnetic binding.

[0026] A magnetic conductive sleeve 33 may be provided in the shell, and the magnetic conductive sleeve is located at the connection position between the shell bottom plate and the magnetic isolation tube. The main part of the magnetic conductive sleeve is in the shape of a sleeve and is sleeved on the magnetic isolation tube. The top height of the magnetic conductive sleeve is lower than the top surface height of the moving iron core under normal conditions, and the bottom thereof is provided with a circular disk-shaped structure. The bottom disk-shaped structure of the magnetic conductive sleeve extends radially outward from the bottom end of the main part of the magnetic conductive sleeve, and the lower surface thereof is in contact with the inner surface (upper surface) of the bottom plate of the shell to facilitate magnetic conduction and magnetic binding.

[0027] The housing may be composed of a main housing (or housing body) with an open bottom and a housing cover 31 covering the open bottom of the main housing to facilitate assembly of components within the housing.

[0028] The shell cover is a magnetic conductive cover, and the magnetic isolation tube through hole on the shell is located in the middle of the shell cover.

[0029] The outer edge of the shell cover can be provided with a short cylindrical connection structure, which is tightly inserted into the bottom opening of the main shell to facilitate connection and magnetic conduction.

[0030] A support sleeve 35 may be provided between the shell cover and the magnetic isolation tube seat. The support sleeve is sleeved on the magnetic isolation sleeve located between the shell cover and the magnetic isolation tube seat. The top end of the support sleeve is connected to the bottom surface (lower surface) of the shell cover, and the bottom end is connected to the top surface of the magnetic isolation tube seat, forming a support between the shell and the magnetic isolation tube seat to effectively hold the magnetic isolation tube.

[0031] The main part of the coil frame should usually be cylindrical and mounted on the outside of the magnetic isolation sleeve. The upper and lower ends of the coil frame are respectively provided with circular upper and lower baffles. The coil is wound in the annular space between the upper and lower baffles of the coil frame. The coil frame can be fixed on the magnetic isolation tube and / or the shell in any appropriate manner.

[0032] A vertical screw may be provided on the top of the second static iron core, which passes through a screw hole provided in the center of the top plate of the shell, and a fastening nut 32 is screwed onto the outer side of the vertical screw. The fastening nut is used to fasten the second static iron core to the shell. This fixing method can effectively avoid deformation or hindrance to the movement of the moving iron core that may be caused by other fixing methods (for example, welding in the magnetic isolation tube), and is easy to operate.

[0033] The vertical dimension of the first working air gap (the corresponding spacing under normal conditions) is preferably 2-3 mm to obtain sufficiently large starting power. The vertical dimension of the second working air gap can be set according to actual needs to ensure that the moving iron core has the required movement range.

[0034] When the above-mentioned setting method of the first working air gap is not suitable or needs further optimization, for example, for a high-power and large-volume electromagnetic head, the first static iron core cross-section, the second static iron core cross-section and the vertical dimensions of the first working air gap and the second working air gap under normal conditions can be set (selected) so that the suction force between the moving iron core and the static iron core at startup is 1.5-2.5 times the suction force between the moving iron core and the static iron core when the top surface of the moving iron core and the lower end of the first static iron core are at the same height. In other words, based on the requirement that the suction force between the moving iron core and the static iron core at startup is 1.5-2.5 times the suction force between the moving iron core and the static iron core when the top surface of the moving iron core and the lower end of the first static iron core are at the same height, the relative proportions between the first static iron core cross-section, the second static iron core cross-section and the vertical dimensions of the first working air gap and the second working air gap under normal conditions are determined. On this basis, the first static iron core cross-section, the second static iron core cross-section and the vertical dimensions of the first working air gap and the second working air gap under normal conditions can be selected based on the moving iron core stroke range (the range of up and down movement) and other factors. Since the reverse force on the electromagnetic head when it is started (for example, the static friction force or the self-sealing pressure of the medium of the valve involved during the start-up) is usually significantly greater than the reverse force on the electromagnetic head during the movement after the start-up and sufficient acceleration is required, the power requirement on the start-up will be significantly greater than the power requirement during the movement. According to experiments, it is appropriate to set the power on the start-up to 1.5-2.5 times the power on the movement in common applications. Under the structure of the present invention, the position where the moving iron core is least attracted by the static iron core during the movement is the position when the top surface of the moving iron core and the lower end of the first static iron core are at the same height. Therefore, it is appropriate to set the relevant dimensions of the relevant parts according to the above method. When it is necessary to increase the power on the start-up, the vertical dimension of the first working air gap can be reduced and / or the cross-sectional area of the first static iron core can be increased. The increase in the cross-sectional area of the second static iron core can increase the suction between the moving iron core and the static iron core when the top surface of the moving iron core and the lower end of the first static iron core are at the same height, but it does not contribute much to the suction on the moving iron core during the start-up.

[0035] A coil spring disengagement device is preferably provided between the movable iron core and the second static iron core, which tends to push the movable iron core and the second static iron core apart when the movable iron core and the second static iron core are in an engaged state, so as to achieve rapid and effective separation.

[0036] The coil spring disengagement device may include a coil spring 46 and a disengagement pin 48. The moving iron core is provided with a spring mounting hole located on its axis. The disengagement pin is in the shape of a cylindrical step that is thin at the top and thick at the bottom. The top of the spring mounting hole is in the shape of a necking corresponding to the disengagement pin. The inner diameter of the necking is slightly larger than the outer diameter of the upper part of the disengagement pin (a fitting gap is left between the two to allow the disengagement pin to slide up and down) and smaller than the outer diameter of the lower part of the disengagement pin (which can effectively prevent the lower part of the disengagement pin from moving upward). The coil spring is located in the spring mounting hole and is in a pre-compressed state. Its top presses against the bottom of the disengagement pin, and its bottom presses against the bottom of the spring mounting hole. Based on the convenience of processing and assembly, the spring mounting hole can be first processed into a through hole, and the disengagement pin and the coil spring can be installed from the bottom of the spring mounting hole. Then, the screw can be screwed on the bottom to form the bottom of the spring mounting hole. The screw can be a screw of equal diameter, and the pre-compression degree of the coil spring can be adjusted by adjusting the screw-in depth of the screw. When appropriate, the bottom of the through hole can also be blocked with an element driven by the electromagnetic head (for example, the valve stem or valve disc directly connected to the lower end of the moving iron core in the electromagnetic valve), and the lower end of the coil spring directly rests on the element.

[0037] The height (vertical dimension) of the upper part (the thinner cylindrical part) of the disengagement pin is greater than (slightly greater than) the length (vertical dimension) of the shrinkage at the top of the spring mounting hole. Therefore, under normal circumstances, the top end of the disengagement pin is partially exposed from the spring mounting hole. When the moving iron core and the second static iron core are attracted, the top end of the disengagement pin is pressed into the mounting coil spring hole by the bottom surface of the second static iron core. Under the action of the coil spring, the disengagement pin applies an upward pushing force to the static iron core, and the lower end of the coil spring applies a downward pushing force to the moving iron core. By appropriately selecting the elasticity and pre-compression degree of the coil spring, the magnitude of the force can be controlled so that it does not hinder the attraction of the moving and static iron cores when power is applied, and can effectively push the moving iron core away from the static iron core when power is not applied.

[0038] A junction box 29 may be mounted on the side wall of the housing. The junction box is provided with connection terminals for connecting external power cables. The connection terminals are connected to the coils via wires passing through the side wall of the housing.

[0039] When this electromagnetic head is applied to a solenoid valve, the lower end of the moving iron core can be connected to the opening and closing member 44 of the valve. The lower end of the opening and closing member is provided with a sealing member 41, which is used to form a valve sealing pair with the corresponding valve seat on the valve body. When the coil is not energized, the moving iron core is in a low position, and the sealing member is pressed on the valve seat, so that the sealing surface on the sealing member is connected with the sealing surface on the valve seat, cutting off the medium channel, and making the valve (corresponding sealing pair) in a closed state. When the coil is energized, the moving iron core drives the starting member to move up to a high position, and a gap appears between the sealing member and the valve seat, so that the valve (corresponding sealing pair) is in an open state.

[0040] The sealing member can be embedded in the lower end surface (bottom surface) of the opening and closing member.

[0041] An annular stepped groove for embedding a sealing member may be provided on the lower end face of the opening and closing member, the inner diameter of the annular stepped groove being smaller than the outer diameter, the sealing member being in the shape of a stepped column with a larger upper portion and a smaller lower portion, the upper portion of which is located in the inner portion of the annular stepped groove, and the lower portion is located in the outer portion of the annular stepped groove, the outer portion of the annular stepped groove being provided with an internal thread, and a compression sleeve 42 being screwed thereon, the upper end face of the compression sleeve being pressed against the annular stepped groove and the reducing end face of the sealing member (the end face formed at the boundary between the two sections), thereby achieving fixation of the sealing member on the annular stepped groove.

[0042] The materials for each component can be selected based on their required magnetic properties. The compression sleeve, opening and closing member, magnetic isolation pipe seat, support sleeve, magnetic isolation pipe, release pin, and spring are preferably made of diamagnetic materials; the magnetic conductive sleeve and housing (including the main housing and housing cover) are preferably made of paramagnetic materials; and the moving iron core, first static iron core, and second static iron core are preferably made of soft magnetic materials.

[0043] The working process involved in the present invention is mainly as follows:

[0044] See also Figure 1 When not working, the coil is not energized. This state can be called normal. The moving iron core is at a low position (or the lower limit of the moving range), and the gap between it and the two static iron cores is the largest. Among them, the gap between it and the first static iron core (the gap between the top surface of the moving iron core and the lower end of the corresponding static iron core) is the first working air gap H1, and the gap between it and the second static iron core is the second working air gap H2.

[0045] See also Figure 2 When starting, the coil is energized and a magnetic field is generated in the inner hole of the coil. The magnetic circuit is divided into two loops: the magnetic lines of force of one loop pass through the moving iron core, the first working gap H1, the first static iron core, the main shell, the magnetic cover, the lower magnetic sleeve, through the magnetic isolation tube wall and return to the moving iron core; the magnetic lines of force of the other loop pass through the moving iron core, the second working air gap H2, the second static iron core, the main shell, the magnetic cover, the magnetic sleeve, through the magnetic tube wall and return to the moving iron core.

[0046] Under the action of magnetic lines of force (magnetic field), the attraction force generated on the first working air gap H1 between the moving iron core and the first static iron core is F1, and the moving iron core is attracted by the first static iron core; the attraction force generated on the second working air gap H2 between the moving iron core and the second static iron core is F2, and the moving iron core is attracted by the second static iron core; the moving iron core generates a solenoid force F4 under the action of the magnetic field of the inner hole of the coil in the magnetic isolation tube, driving the moving iron core to approach the second static iron core. Therefore, the moving iron core starts to start (which can be called a one-time start) under the combined action of F1, F2 and F4 in the magnetic isolation tube, forming an upward trend or upward acceleration, driving the moving iron core to approach the second static iron core. The driving force (combined force) of one start is: F 初 =F1+F2+F4.

[0047] See also Figure 3 When the moving iron core moves up to a certain extent under the joint action of F1, F2 and F4, the height of the top surface of the moving iron core is consistent with the height of the lower end of the first static iron core, the first working air gap H1 between the moving iron core and the first static iron core is closed, and the second working air gap H2 becomes (renamed as) the third working air gap H3, which can be regarded as the end of the movement process of the moving iron core under the joint action of F1, F2 and F4. At this time, the third working air gap between the moving iron core and the second static iron core is H3, and the suction force generated by the second static iron core in the third working air gap H3 is F3. The moving iron core is mainly attracted by the second static iron core, and the suction force of the first static iron core on the moving iron core can be roughly ignored. Under the joint action of the suction force F3 generated by the third working air gap H3 and the solenoid force F4, the moving iron core moves toward the second static iron core (which can be called secondary start), and the driving force (combined force) of the secondary start is F 终 =F3+F4.

[0048] See also Figure 4 When the moving iron core moves up and is attracted to the second static iron core, the moving iron core is at a high position and cannot move further up. The moving process of the moving iron core under the joint action of F3 and F4 ends, and the third working air gap H3 disappears.

[0049] When the coil is powered off, the attraction between the moving iron core and the two static iron cores and the solenoid force in the magnetic isolation tube disappear (there may be a small residual magnetic attraction), and the moving iron core moves down under the action of its own weight and spring force and returns to Figure 1 The status shown.

[0050] Unless otherwise specified or one preferred or optional technical means is a further limitation of another technical means, the preferred and optional technical means disclosed in the present invention can be arbitrarily combined to form several different technical solutions.

Claims

1. An efficient and high-power electromagnetic drive head, comprising a housing and a coil, a moving iron core, a static iron core, and a magnetic isolation tube arranged vertically coaxially with the housing. The coil, moving iron core, and static iron core are installed within the housing. The coil surrounds the outside of the magnetic isolation tube and is fixedly mounted on a coil frame. The magnetic isolation tube passes through a magnetic isolation tube through-hole on the bottom plate of the housing. The top end of the magnetic isolation tube is fixedly connected to the top plate of the housing, and the bottom end is located outside the housing. The static iron core includes a first static iron core and a second static iron core. The main part of the first static iron core is tubular and is sleeved on the outer side of the upper part of the magnetic isolation tube. It is located between the coil and the magnetic isolation tube, and its lower end is lower than the lower end of the second static iron core. The second static iron core and the moving iron core are arranged in the magnetic isolation tube. The second static iron core is fixedly installed in the upper part of the magnetic isolation tube. The moving iron core is located below the second static iron core and slides with the inner wall of the magnetic isolation tube. Under normal conditions, a first working air gap is left between its top surface and the lower end of the first static iron core, and a second working air gap is left between its top surface and the lower end of the second static iron core. When starting, the first working air gap between the first static iron core and the moving iron core is significantly smaller than the second working air gap between the second static iron core and the moving iron core, and the suction force between the first static iron core and the moving iron core is significantly greater than the suction force of the second static iron core.

2. The high-efficiency and high-power electromagnetic drive head according to claim 1, characterized in that A circular disk-shaped structure is provided on the top of the first static iron core. The disk-shaped structure on the top of the first static iron core extends radially outward from the top of the main body of the first static iron core, and its upper surface is in contact with the inner surface of the top plate of the shell.

3. The high-efficiency and high-power electromagnetic drive head according to claim 1, characterized in that A magnetic conductive sleeve is provided in the shell, and the magnetic conductive sleeve is located at the connection position between the shell bottom plate and the magnetic isolation tube. The main part of the magnetic conductive sleeve is in the shape of a sleeve and is sleeved on the magnetic isolation tube. The top height of the magnetic conductive sleeve is lower than the top surface height of the moving iron core under normal conditions, and the bottom of the magnetic conductive sleeve is provided with a circular disk-shaped structure. The bottom disk-shaped structure of the magnetic conductive sleeve extends radially outward from the bottom end of the main part of the magnetic conductive sleeve, and its lower surface is in contact with the inner surface of the bottom plate of the shell.

4. The high-efficiency and high-power electromagnetic drive head according to claim 1, characterized in that The housing is composed of a main housing with an open bottom and a housing cover covering the open bottom of the main housing.

5. The high-efficiency and high-power electromagnetic drive head according to claim 1, characterized in that A vertical screw is provided on the top of the second static iron core. The vertical screw passes through a screw hole in the center of the top plate of the shell. A fastening nut is screwed on the outer side of the vertical screw, and the second static iron core is fastened to the shell through the fastening nut.

6. The high-efficiency and high-power electromagnetic drive head according to claim 1, characterized in that A junction box is installed on the side wall of the shell. The junction box is provided with a connection terminal for connecting an external power supply cable. The connection terminal is connected to the coil via a wire passing through the side wall of the shell.

7. The high-efficiency, high-power electromagnetic drive head according to any one of claims 1 to 6, characterized in that The vertical dimension of the first working air gap is 2-3 mm.

8. The high-efficiency, high-power electromagnetic drive head according to any one of claims 1 to 6, characterized in that By setting the cross-section of the first static iron core, the cross-section of the second static iron core and the vertical dimensions of the first working air gap and the second working air gap under normal conditions, the suction force between the moving iron core and the static iron core during startup is 1.5-2.5 times the suction force between the moving iron core and the static iron core when the top surface of the moving iron core and the lower end of the first static iron core are at the same height.

9. The high-efficiency, high-power electromagnetic drive head according to any one of claims 1 to 6, characterized in that A coil spring disengagement device is provided between the movable iron core and the second static iron core, which tends to push the movable iron core and the second static iron core apart when the movable iron core and the second static iron core are in an attracted state.

10. The high-efficiency and high-power electromagnetic drive head according to claim 9, characterized in that The coil spring disengagement device includes a coil spring and a disengagement pin. The moving iron core is provided with a spring mounting hole located on its axis. The disengagement pin is in the shape of a cylindrical step that is thin at the top and thick at the bottom. The top of the spring mounting hole is in the shape of a necking corresponding to the disengagement pin. The inner diameter of the necking is slightly larger than the outer diameter of the upper part of the disengagement pin and smaller than the outer diameter of the lower part of the disengagement pin. The coil spring is located in the spring mounting hole and is in a pre-compressed state. Its top is pressed against the bottom of the disengagement pin, and its bottom is pressed against the bottom of the spring mounting hole.

Images