A lifting electromagnet and control method for accurately sucking multiple steel plates

Abstract

The present invention discloses a lifting electromagnet and control method for accurately lifting multiple steel plates. The lifting electromagnet includes a top plate and at least one electromagnet group fixed to the top plate, each electromagnet group having multiple different electromagnets. The electromagnet includes a hollow inner magnetic pole, an outer magnetic pole, a coil, and a junction box. The coil is wound around the hollow inner magnetic pole and connected to the junction box, and the outer magnetic pole is arranged on the periphery of the coil. The outer magnetic poles of different electromagnets have different wall thicknesses. The lifting electromagnet disclosed in the present invention is provided with at least one electromagnet group, each electromagnet group having multiple different electromagnets, and the outer magnetic poles of different electromagnets have different wall thicknesses, thereby achieving the suction and lifting of steel plates of different thicknesses, thereby accurately lifting multiple steel plates.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic suction and lifting equipment, and in particular to a lifting electromagnet for accurately sucking and lifting multiple steel plates and a control method. Background Art

[0002] Lifting electromagnets for lifting steel plates have been widely used. Traditional lifting electromagnets for lifting steel plates usually do not have the requirement to accurately lift the number of steel plates during operation. However, with the development of unmanned operations, many work sites have required the precise lifting of multiple steel plates of the same or different thicknesses. At present, there is no method in the world that can solve the problem of precise lifting of multiple steel plates, let alone lifting electromagnets that can accurately lift multiple steel plates. Summary of the Invention

[0003] The invention provides a lifting electromagnet for accurately sucking and lifting multiple steel plates, which can realize the accurate sucking and lifting of multiple steel plates.

[0004] The technical means adopted by the present invention are as follows:

[0005] A lifting electromagnet for accurately lifting multiple steel plates comprises a top plate and at least one electromagnet group fixed to the top plate, each electromagnet group having a plurality of different electromagnets;

[0006] The electromagnet includes a hollow inner magnetic pole, an outer magnetic pole, a coil and a junction box, the coil is wound around the hollow inner magnetic pole and connected to the junction box, and the outer magnetic pole is arranged on the outer periphery of the coil;

[0007] The wall thickness of the outer magnetic poles of different electromagnets is different.

[0008] Furthermore, the hollow inner magnetic pole and the outer magnetic pole of the same electromagnet have the same magnetic pole area.

[0009] Furthermore, the wall thickness of the outer magnetic poles of different electromagnets is 1t, 2t, 3t…nt;

[0010] Where n is the number of electromagnets in each electromagnet group;

[0011] t is the thinnest thickness of the sucked steel plate.

[0012] Furthermore, the coils of the same electromagnets in different electromagnet groups are connected in series.

[0013] A method for controlling a lifting electromagnet for accurately sucking and lifting multiple steel plates comprises the following steps:

[0014] Step 1: Obtain the number of steel plates to be lifted and the thickness of each steel plate;

[0015] Step 2: Calculate the required wall thickness of the outer magnetic pole of the electromagnet according to the number of steel plates to be sucked and the thickness of each steel plate;

[0016] Step 3: Control different electromagnets in the electromagnet group to work according to the wall thickness of the outer magnetic pole of the electromagnet required by calculation.

[0017] Furthermore, the wall thickness of the outer magnetic pole of the electromagnet required for calculation according to the number of the suction and lifting steel plates and the thickness of each steel plate is calculated by formula (1),

[0018] (d1+d2+d3…d m-1 +0.4×d m )≤D≤(d1+d2+d3…d m-1 +d m ) (1)

[0019] Where: m is the number of steel plates that need to be sucked and lifted;

[0020] d1, d2, d3…d m-1 d m The thickness of each steel plate that needs to be lifted from the end close to the electromagnet to the end away from the electromagnet;

[0021] D is the required wall thickness of the outer pole of the electromagnet.

[0022] Compared with the prior art, the lifting electromagnet disclosed in the present invention can accurately suck and lift multiple steel plates by setting up at least one group of electromagnet groups, each group of electromagnet groups has multiple different electromagnets, and the outer magnetic pole wall thickness of different electromagnets is different, thereby realizing the suction and lifting of steel plates of different thicknesses, thereby accurately sucking and lifting multiple steel plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a front view of the lifting electromagnet disclosed in the present invention for accurately sucking multiple steel plates;

[0024] Figure 2 for Figure 1 Bottom view of

[0025] Figure 3 for Figure 1 A top view of the wiring box is not shown;

[0026] Figure 4 for Figure 1 Left view of .

[0027] In the figure: 1, top plate, 11, lifting ear, 2, electromagnet group, 2-1, first electromagnet, 2-2, second electromagnet, 2-3, third electromagnet, 2-4, fourth electromagnet, 20, hollow inner magnetic pole, 21, outer magnetic pole, 22, coil, 23, junction box. DETAILED DESCRIPTION

[0028] like Figures 1 to 4 The lifting electromagnet disclosed in the present invention for accurately sucking and lifting multiple steel plates comprises a top plate 1 and at least one electromagnet group 2 fixed on the top plate 1, wherein each electromagnet group 2 comprises a plurality of different electromagnets;

[0029] The electromagnet includes a hollow inner magnetic pole 20, an outer magnetic pole 21, a coil 22 and a junction box 23. The coil 22 is wound around the hollow inner magnetic pole 20 and connected to the junction box 23. The outer magnetic pole 21 is arranged on the outer periphery of the coil 22.

[0030] The wall thickness of the outer magnetic poles 21 of different electromagnets is different.

[0031] Specifically, in this embodiment, there are three groups of electromagnet groups 2 on the top plate 1, and each group of electromagnet groups 2 has four different electromagnets, namely the first electromagnet 2-1, the second electromagnet 2-2, the third electromagnet 2-3 and the fourth electromagnet 2-4. The multiple groups of electromagnet groups are arranged in sequence from one end to the other end of the top plate. The number of electromagnet groups and the number of electromagnets in each electromagnet group can be designed as needed; the electromagnet includes a hollow inner magnetic pole 20, an outer magnetic pole 21, a coil 22 and a junction box 23, the coil 22 is wound on the hollow inner magnetic pole 20 and connected to the junction box 23, and the outer magnetic pole 21 is arranged on the outer periphery of the coil 22.

[0032] When using the lifting electromagnet disclosed in the present invention to lift steel plates, the magnetic lines of force always pass through areas with low magnetic resistance when passing through the ferromagnetic material being attracted. At the same time, when lifting multiple steel plates, the air gap magnetic resistance of each steel plate is very large, so the magnetic lines of force always reach the second layer of steel plates after the first layer of steel plates is saturated, and then overcome the air gap magnetic resistance between the first and second layers of steel plates. The same is true for the third and fourth layers of steel plates. Moreover, the most important thing is that if the outer magnetic pole of the electromagnet reaches magnetic saturation first in the magnetic circuit passing through the magnetic lines of force, then even if the magnetic potential is increased, the number of magnetic lines of force passing through the outer magnetic pole will not increase, thus limiting the number of magnetic lines of force passing through the attracted steel plate, making it unable to overcome the air gap between the steel plates and attract the steel plate below. Since at least one group of electromagnet groups is provided in the present application, and each group of electromagnet groups contains a plurality of different electromagnets, the outer magnetic pole wall thicknesses of different electromagnets are different, so that the outer magnetic poles of different electromagnets have different numbers of magnetic lines of force when the magnetic circuit passing through the magnetic lines of force reaches saturation, thereby being able to suck and lift steel plates of different total thicknesses. When it is necessary to suck and lift steel plates of different thicknesses, different electromagnets are controlled to work to achieve precise suction and lifting of multiple different steel plates.

[0033] Furthermore, the hollow inner magnetic pole and the outer magnetic pole of the same electromagnet have the same magnetic pole area.

[0034] Furthermore, the wall thickness of the outer magnetic poles of different electromagnets is 1t, 2t, 3t…nt;

[0035] Where n is the number of electromagnets in each electromagnet group;

[0036] t is the thinnest thickness of the sucked steel plate.

[0037] By sequentially adjusting the outer magnetic pole wall thickness to 1t, 2t, 3t, and so on, more precise control is achieved to precisely lift and hold different numbers of steel plates. In this embodiment, the outer magnetic pole wall thickness of electromagnet 2-1 is set to t, the outer magnetic pole wall thickness of electromagnet 2-2 is twice that of electromagnet 2-1 and is set to 2t, the outer magnetic pole wall thickness of electromagnet 2-3 is three times that of electromagnet 2-1 and is set to 3t, and the outer magnetic pole wall thickness of electromagnet 2-4 is four times that of electromagnet 2-1 and is set to 4t.

[0038] Furthermore, the coils of the same electromagnets in different electromagnet groups are connected in series. Specifically, in this embodiment, the three coils of the first electromagnet are connected in series and then connected to the junction box, the three coils of the second electromagnet are connected in series and then connected to the junction box, the three coils of the third electromagnet are connected in series and then connected to the junction box, and the three coils of the fourth electromagnet are connected in series and then connected to the junction box. The series connection of the coils of the same electromagnets in different electromagnet groups can reduce the number of control circuits of the electromagnets by the electronic control device and reduce the total output current, making it easier for the electronic control device to control the electromagnets.

[0039] A method for controlling a lifting electromagnet for accurately sucking and lifting multiple steel plates comprises the following steps:

[0040] Step 1: Obtain the number of steel plates to be lifted and the thickness of each steel plate;

[0041] Step 2: Calculate the required wall thickness of the outer magnetic pole of the electromagnet according to the number of steel plates to be sucked and the thickness of each steel plate;

[0042] Step 3: Control different electromagnets in the electromagnet group to work according to the wall thickness of the outer magnetic pole of the electromagnet required by calculation.

[0043] Furthermore, the wall thickness of the outer magnetic pole of the electromagnet required for calculation according to the number of the suction and lifting steel plates and the thickness of each steel plate is calculated by formula (1),

[0044] (d1+d2+d3…d m-1 +0.4×d m )≤D≤(d1+d2+d3…d m-1 +d m ) (1)

[0045] Where: m is the number of steel plates that need to be sucked and lifted;

[0046] d1, d2, d3…d m-1 d m The thickness of each steel plate that needs to be lifted from the end close to the electromagnet to the end away from the electromagnet;

[0047] D is the required wall thickness of the outer pole of the electromagnet.

[0048] The above method can achieve accurate suction and lifting of different numbers of steel plates.

[0049] Example 1

[0050] In this embodiment, the wall thicknesses of the hollow inner magnetic poles and outer magnetic poles of the four different electromagnets are different. Taking the thickness of the suction and lifting steel plate as 6mm-60mm as an example, the thicknesses of the outer magnetic poles of the four different electromagnets in the present invention are as follows: the outer magnetic pole wall thickness of the first electromagnet is 6mm, the outer magnetic pole wall thickness of the second electromagnet is 12mm, the outer magnetic pole wall thickness of the third electromagnet is 18mm, and the outer magnetic pole wall thickness of the fourth electromagnet group is 24mm.

[0051] If the outer magnetic pole wall thickness of the first electromagnet is 6mm, the first electromagnet can only accurately lift steel plates with a minimum thickness of 6mm or more. When lifting steel plates with a thickness of more than 6mm, even if the electromagnet's magnetic potential is increased, the outer magnetic pole is already saturated, and the magnetic lines of force are unable to penetrate the first steel plate and reach the second steel plate. Even if some leakage magnetic flux reaches the second steel plate, it is unable to lift the second steel plate. If two steel plates with a thickness of 6mm are to be lifted, a second electromagnet is used. The outer magnetic pole wall thickness of the second electromagnet is 12mm. The second electromagnet can only accurately lift two steel plates with a minimum thickness of 6mm. When lifting two steel plates with a thickness of more than 6mm, even if the electromagnet's magnetic potential is increased, the outer magnetic pole is already saturated, and the magnetic lines of force, after penetrating the first steel plate to reach the second steel plate, are unable to penetrate the second steel plate to reach the third steel plate. Even if some leakage magnetic flux reaches the third steel plate, it is unable to lift the third steel plate. If you need to lift three 6mm thick steel plates, use the third electromagnet. The outer magnetic pole wall thickness of the third electromagnet is 18mm, and the third electromagnet can accurately lift three steel plates with a minimum thickness of 6mm. If you need to lift four 6mm thick steel plates, use the fourth electromagnet. The outer magnetic pole wall thickness of the fourth electromagnet is 24mm, and the fourth electromagnet can only accurately lift four steel plates with a minimum thickness of 6mm.

[0052] The area of ​​the hollow inner magnetic pole of the electromagnet is the same as the area of ​​the outer magnetic pole, and the thickness of the steel plate of the hollow inner magnetic pole can be calculated based on this.

[0053] The formula for the electromagnet's suction force is: F = (B / 5000)²S, where B is the magnetic flux density at the contact surface between the electromagnet and the steel plate, and S is the contact area. To achieve the required suction force, S must be increased. This means that multiple electromagnets of each type are required to achieve the required suction area S. Similarly, the length and width of each electromagnet must also be set to achieve the required suction force.

[0054] Corresponding relationship between suction and lifting steel plate and electromagnet

[0055] First electromagnet (side pole thickness 6mm): 1 piece of 6mm-12mm thick steel plate;

[0056] Second electromagnet (side pole thickness 12mm): 2 steel plates of 6mm-8mm thickness, 1 steel plate of 12mm-24mm thickness;

[0057] The third electromagnet (side pole thickness 18mm): 3 6mm-7mm thick steel plates, 2 9mm-12mm thick steel plates, 1 24mm-36mm thick steel plate;

[0058] The fourth electromagnet (side pole thickness 24mm): 4 6mm-7mm thick steel plates, 3 8mm-10mm thick steel plates, 2 13mm-17mm thick steel plates, and 1 36mm-60mm thick steel plate.

[0059] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A lifting electromagnet for accurately lifting multiple steel plates, characterized by: It includes a top plate and at least one electromagnet group fixed on the top plate, each electromagnet group having a plurality of different electromagnets; The electromagnet includes a hollow inner magnetic pole, an outer magnetic pole, a coil and a junction box, the coil is wound around the hollow inner magnetic pole and connected to the junction box, and the outer magnetic pole is arranged on the outer periphery of the coil; The wall thickness of the outer magnetic poles of different electromagnets is different; The wall thickness of the outer magnetic poles of different electromagnets is 1t, 2t, 3t…nt; Where n is the number of electromagnets in each electromagnet group; t is the thinnest thickness of the sucked steel plate.

2. The lifting electromagnet for accurately lifting multiple steel plates according to claim 1 is characterized in that: The hollow inner magnetic pole and the outer magnetic pole of the same electromagnet have the same magnetic pole area.

3. The lifting electromagnet for accurately lifting multiple steel plates according to claim 2 is characterized in that: The coils of the same electromagnets in different electromagnet groups are connected in series.

4. A method for controlling a lifting electromagnet for accurately sucking and lifting multiple steel plates as claimed in claim 1, characterized in that: The following steps are included: Step 1: Obtain the number of steel plates to be lifted and the thickness of each steel plate; Step 2: Calculate the required wall thickness of the outer magnetic pole of the electromagnet according to the number of steel plates to be sucked and the thickness of each steel plate; The wall thickness of the outer magnetic pole of the electromagnet required for calculation is calculated according to the number of steel plates to be sucked and the thickness of each steel plate by formula (1). <h2 style=";text-align:left;direction:ltr">(d1+d2+d3…d<h2 style=";text-align:left;direction:ltr"> m-1 <h2 style=";text-align:left;direction:ltr"> +0.4×d<h2 style=";text-align:left;direction:ltr"> m <h2 style=";text-align:left;direction:ltr"> )≤D≤(d1+d2+d3…d)<h2 style=";text-align:left;direction:ltr"> m-1 <h2 style=";text-align:left;direction:ltr"> +d<h2 style=";text-align:left;direction:ltr"> m <h2 style=";text-align:left;direction:ltr"> )(1) Where: m is the number of steel plates that need to be sucked and lifted; d1, d2, d3…d m-1 d m The thickness of each steel plate that needs to be lifted from the end close to the electromagnet to the end away from the electromagnet; D is the required wall thickness of the outer magnetic pole of the electromagnet; Step 3: Control different electromagnets in the electromagnet group to operate according to the calculated required wall thickness of the outer magnetic pole of the electromagnet.

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