KR100627245B1 - A composit magnet linearly adjustable magneticity power and lift having the magnet, and method for control a number of lifted sheets - Google Patents

Abstract

The present invention relates to an Alnico magnet having a residual magnetic flux density of 10 kG or more, coercive force of 700 to 800 Oe or less, and having a nearly linear demagnetization curve, using AlNiCo magnets as a variable magnet that can be controlled by current. It is constructed using Nd-Fe-B magnet. A variable magnet is a composite magnet made by combining two or more magnets. For example, the first magnet is composed of a first magnet and a second magnet, and the first magnet is an Alnico5 magnet, a residual magnetic flux density of 13.5 kG, and a coercive force of 800 Oe. The second magnet is an Alnico2 magnet, which is an Alnico 2 series magnet having a residual magnetic flux density of 6.5 kG and a coercive force of 500 Oe.

Alnico magnet, permanent magnet for hoist

Description

MAGNET LINEARLY ADJUSTABLE MAGNETICITY POWER AND LIFT HAVING THE MAGNET, AND METHOD FOR CONTROL A NUMBER OF LIFTED SHEETS}

1 is a side cross-sectional view of a hoisting magnet of the present invention

Fig. 2Alnico Magnet Potato Characteristics

3 is a graph comparing the potato characteristics of the present invention and the conventional hoist

Figure 4 Potato Characteristic Curve Graph of Multiple Alnicos

The present invention provides a hoisting magnet capable of linearly changing the potato characteristics of a variable magnet, and a hoisting magnet and hoisting machine for applying adsorption and detachment of a load by a desired amount (quantity), and controlling the number of hoists using the same. It is about a method.

The utility model control device for hoisting has been disclosed in Registration Utility Model Utility Utility No. 0248250 to sense the magnetic force state of the hoist and to appropriately control the strength of the magnetic force according to the load.

This device is characterized in that the magnetic magnet for hoisting magnet generated by the solenoid coil, the permanent magnet hoisting magnet combined with the permanent permanent magnet and the variable permanent magnet generating magnetic flux by the solenoid coil, and the magnetic flux density of the hoisting magnet A magnetic detector for detecting, a current detector for detecting the magnitude of the current flowing through the solenoid coil, a magnetic control unit for controlling the magnetic force of the hoisting magnet by flowing a current through the solenoid coil, and the hoisting magnet to carry the load. An operation device for controlling adsorption and desorption, a central control unit for receiving signals from the magnetic force detector and the current detector, and generating a control signal for controlling the magnetic force control unit according to an operation signal of the operation unit; Display device that displays status to determine safe magnetic force status It has been made.

In addition, Utility Model Registration No. 20-0157844, filed and registered on December 24, 1996, discloses a control device for a permanent magnet hoisting machine. A step set value selected by the maximum suction switch and the removable switch; A ramp signal generator for adjusting the acceleration / deceleration output according to the characteristics of each magnet; A voltage adder that adds an output value of the ramp signal generator and a minimum set value for setting a minimum output during movement; A waveform transformer which, when sent to the gate trigger waveform generator of the silicon controlled rectifier according to the result of the voltage adder, converts the waveform generated by the trigger waveform generator into a waveform capable of turning on the silicon controlled rectifier; A current signal amplifier for amplifying a current generated from a thyristor module by a current sensor while a silicon controlled rectifier is turned on as an output of the waveform transformer and amplifying the current to a voltage corresponding to an input of a controller; The present invention relates to a control device for a permanent magnet hoist, characterized in that it is composed of a microcomputer to perform magnetization and demagnetization by the signal of the time set value for setting the time to send the output and the output of the switch signal.

These conventional hoisting magnets and control devices utilize one of the characteristics of the residual magnetic flux density and the coercive force of the hoisting permanent magnet itself. That is, by designing an appropriate adsorption force using the characteristics of the residual magnetic flux density, it can be said that a satisfactory operation for the application of adsorption and desorption of the designed heavy material.

A magnet having a strong adsorption force was fabricated using an alnico magnet having a residual magnetic flux density of 13 kG and a coercive force of 750 Oe. It was used for the simple operation of adsorption of heavy steel bars such as slabs, billets, bars, etc., by transport and desorption.

As shown in FIG. 1, the conventional hoisting magnet and its control apparatus use Sm2Co17-type magnets of magnetism in the variable magnets 3 and 3 ', and alnico in the stationary magnets 4 and 4'. The magnetic circuit is constructed using a magnet, and the main purpose is to increase the hoisting capacity of the hoist.

In the prior art, since the polarity of the variable magnets 3 and 3 'must be changed by applying electric power to the solenoid coils 2 and 2' for the adsorption and desorption of the variable magnets 3 and 3 ', Current had to be applied.

For example, the amount of current to be applied in order to convert the polarity of the Sm2Co17 magnet used in the conventional invention is 640 ~ 950 kA per 1m because the coercive force of the Sm2Co17 magnet is 8000 ~ 15,000 Oe. If the hoist is applied to several necessary industrial sites, it will face the problem of supplying tremendous power.

When the conventional Sm2Co17 is used, the maximum hoisting capacity is improved to about 12 to 13 tons, but the amount of current input is about 400 to 600 (A).

In addition, it was possible only for simple transfer operations through the adsorption and desorption of heavy materials such as slabs, hot coils, various round bars and reinforcing bar bundles.

Steel plate such as iron plate may be adsorbed and transported several sheets at once and sent at once, but it may be necessary to drop one or two sheets or only an appropriate amount at a suitable place during adsorption and transfer of several iron plates.

In addition, when a plurality of iron plates are stacked, only a few of them need to be adsorbed and moved. However, in the case of a plurality of iron plates overlapping with conventional hoisting machines, it is inconvenient to separate and adsorb the amount to be physically adsorbed. Precise magnetic force control that can be dropped only one by one was very inconvenient. For example, in Tables 1 and 2, in case of using a conventional Alnico 5 magnet alone, the voltage applied to the electromagnet coil is adsorbed due to the difference of several volts or 2 is adsorbed in order to bond the 6mm iron plate as desired. It is very difficult to control while giving the voltage difference between male bolts, and if you try to drop the iron plate by demagnetizing, there is no voltage difference that is impossible to select and drop one sheet.

In addition, the conventional hoisting magnet has to use a material having a large residual magnetic flux in order to generate a strong adsorptive force, and a lot of power is required to demagnetize the magnet for the hoisting magnet which saves energy.

The present invention is to provide a hoisting magnet and a hoist using the hoisting magnet, which is precisely controlled to reduce the power of magnetizing and demagnetizing, and to adsorb and desorb unit quantities of loads compared to the prior art. It is desirable to provide a hoist that enables to perform necessary work with a current of about one tenth, thereby realizing power saving and improving work convenience and efficiency in an industrial site in which several hoisting machines are installed.

As shown in Fig. 1, the hoisting magnet of the present invention includes a pole [6 or less (6 '), which is a conductor that allows magnetic flux to pass well, and the same as that of the pole 6, Solenoid coils (excitation coils 2) around the core 3 made of a permanent magnet attached to the side and a core 3 made of a material having a residual magnetic flux density above a predetermined value attached to the top of the pole 6. The coils are wound to the outside of the variable magnets (2, 3), the fixed magnet (4) and the variable magnets (2, 3) whose magnitude and direction of the residual magnetic flux are determined according to the direction and polarity of the current flowing through the coil (2). A magnet for a hoist, which is attached to and forms a magnetic path and includes a yoke 1 for coupling and supporting a pole, a stationary magnet, and a variable magnet.

A lower plate 5 of a nonmagnetic material is provided on the lower surface of the yoke 1 to block the influence of the leakage magnetic flux of the stator magnet.

The core 3 of the variable magnet is a composite magnet made by superimposing two or more magnets having different magnetization characteristics. The core 3 of the variable magnet is magnetized by flowing a positive current in a coil wound around the core and demagnetizing by flowing a reverse current. Synthetic flux with the stator magnet output from the pole has a potato characteristic that is almost linearly demagnetized against the magnetic force demagnetizing.

The core 3 of the variable magnet is composed of a first magnet a made of a material having a high residual magnetic flux density and a second magnet b made of a material having a smaller residual magnetic flux density than the first magnet a. When the demagnetizing current flowing through the coil 2 wound around (3) flows, the synthetic magnetic flux with the stator magnet 4 output from the pole 6 has a potato characteristic linearly demagnetized by the magnetic force demagnetizing.

The first magnet (a) and the second magnet (b), which are the core 3 of the variable magnet, are Al-Ni-Co magnets, and the stator magnets are realized in the actual product of the present invention by using Nd-Fe-B magnets. I was.

Specifically, the first magnet is an Alnico 5 (US standard number) magnet, has the same area as the core 3, has a length of half the length of the core, the residual magnetic flux density is 13.5 kG, and the coercive force is 800 Oe. Use 5 series magnets.

The second magnet is an Alnico2 magnet, which has the same area as the core 3 and has a length that is half the length of the core, so that when the two first magnets are combined, the second magnet becomes the core of the variable magnet. The second magnet is an Alnico 2 series magnet with a residual magnetic flux density of 6.5 kG and a coercive force of 500 Oe.

Alnico magnets with a residual magnetic flux density of 10 kG or more, coercive force of 700 to 800 Oe or less, and almost linear demagnetization curves were suitable for realizing the present invention. Since it is not yet possible to synthesize, a composite magnet of desired characteristics was developed through a combination of two or more alnico magnets having various magnetization characteristics.

As shown in Fig. 3, the characteristics of the composite magnets made of alnico magnets change the residual magnetic flux density while varying the reverse voltage range from 0 to 250 (V). Indicates.

Using the hoisting magnet described above, a hoist using a permanent magnet capable of adsorbing or detaching as many sheets as necessary from a plurality of iron plates can be realized. This hoist can precisely control the magnetization and the amount of demagnetization of the variable magnet as described later using a magnetic force control device as described in the prior art.

The control test of magnetic force through the control of the number of steel sheets shows that the range of the number control has become very wide. When 6 sheets of 6 mm plates and 2 sheets of 10 mm plates are adsorbed one by one, up to 280 (V) range, and when six sheets are adsorbed and desorbed one by one at the same time, it is expanded to the range of reverse voltage 160 (V), resulting in reliable control. Compared to the Alnico magnets of Alnico 5 series, the control section was expanded to about 3.8 times when adsorbed and 2.2 times when desorbed. At the same time, two sheets of alnico magnets of the Alnico 5 series were not simultaneously adsorbed or desorbed two or three sheets at a time.

The specific configuration and experimental example are as follows.

The magnetic pole arrangement of the first magnet, the second magnet (also referred to as an alnico composite magnet), and the Nd-Fe-B magnet is arranged as shown in Fig. 1 (may be arranged to be opposite polarity). As shown in FIG. 1, the lower surface is disposed to be the north pole, and the solenoid coil 2 'is disposed so that the upper surface becomes the north pole when the current is applied as shown in FIG.

The stationary magnets 4 and 4 'of Nd-Fe-B are arranged on the side of the poles 6 and 6', and the variable magnets 3 and 3 'of the Alnico composite magnet are placed on the poles 6 and 6'. After placement on the top of), the amount of effective magnetic flux can be controlled with less current by winding the solenoid coil around it.

Since the amount of current requires 55.7 kA per m for the coercive force 700 Oe, only one tenth of the current is required compared to the prior art.

A rare earth Nd-Fe-B magnet was disposed in contact with the slope of the square poles 6 and 6 '. The magnetic circuit was constructed by enclosing the non-contacting opposite side of the alnico variable magnet and the Nd-Fe-B magnet and the yoke (1). In addition, the Alnico composite magnet has a residual magnetic flux density of 13.5 kG and a coercive force of Alnico-5 series of Alnico magnets and residual magnetic flux so that the linear residual magnetic flux density changes according to the amount of control voltage (or current). Alnico 5 series and eggs using Alnico composite magnets (3, 3 ') combined with Alnico 2 series alnico magnets with a density of 6.5 kG and a coercive force of 500 Oe. Permanent magnets with intermediate potato properties of Nico 2 series were obtained.

Figure 2 is a graph showing the potato characteristics according to the grade of the Alnico magnets, Figure 3 is a graph showing the potato characteristics of the composite magnet of the present invention, Figure 4 is a graph showing the potato characteristics of various kinds of magnets.

In FIG. 3, a conventional hoisting machine (alnico 5 series alone) using an alnico magnet of alnico 5 series (based on MMPA code) having a residual magnetic flux density of 13.5 kG and a coercive force of 800 Oe is produced. Alnico is a combination of alnico magnets of 13.5 kG residual magnetic flux and 800 Oe coercive force and alnico magnets of 6.5 kG residual magnetic flux density and 500 Oe coercive force. The present invention using a composite magnet (alnico composite magnet) was produced to compare the characteristics of the conventional hoist and the hoist of the present invention to the potato characteristics and magnetic force control.

After assembling the hoist of both models, put 100% of rated current into solenoid coil and make the variable magnets (3, 3 ') fully adsorbed, and then reverse the voltage (or current) to -10 (V) to solenoid coil. ) And then apply -20 (V) little by little to apply 100% reverse voltage to complete desorption, and measure the magnetic flux of poles 6 and 6 ' The curve was completed. It is possible to determine the magnitude of residual magnetic flux density of the hoist according to the application amount of reverse voltage (or reverse current) in the state of adsorbing the object, and to determine the amount of current to be injected to induce partial desorption of steel materials. Can be.

In the potato characteristic shown in FIG. 3, the magnetic field generation range of the general purpose hoist using the Alnico 5 series magnet alone has a maximum magnetic flux density of 17.0 kG and the magnetic flux density is high, so the adsorption force is strong, but the magnetic flux generated by applying voltage (or current) The range that can be controlled is made possible in the range of 0 ~ 70 (V) and has a narrow adjustment range.

On the other hand, the hoisting magnet of the present invention using the Alnico composite magnet can control the maximum magnetic flux density of 11.0 kG to the range of 0 ~ 170 (V), the control range is wide and is much expanded compared to the prior art Able to know.

In the following table, four steel plates 6mm x 1220mm x 1220mm thick and two steel plates 10mm x 1220mm x 1200mm thick are stacked using these two hoisting machines, and then each sheet is individually adsorbed and six sheets are removed at the same time. This is data obtained by experiment of desorption.

Adsorption control test Thickness of iron plate Conventional Magnets (Alnico 5 Series Only) Magnet of the present invention (alnico composite magnet) Remarks 6 mm 50 (V) 50-100 (V) 6 mm 57 (V) 110 ~ 130 (V) 6 mm 65 (V) 130 ~ 140 (V) 6 mm 67 (V) 150 ~ 170 (V) 10 mm 74 (V) 200 ~ 280 (V) 10 mm 82 (V) 300 or more (V)

Note) The order of individual adsorption from 1 sheet of 6 mm.

Desorption Control Test Thickness of iron plate                                              Conventional Magnets (Alnico 5 Series Only) Magnet of the present invention (alnico composite magnet) Remarks                                              6 mm 88 (V) 170 or more (V) 6 mm 88 (V) 140 ~ 160 (V) 6 mm 78 (V) 130 ~ 140 (V) 6 mm 78 (V) 120 ~ 130 (V) 10 mm 77 (V) 110 ~ 120 (V) 10 mm 65 (V) 50-100 (V)

Note) Individual removal order starting with 1 sheet of 10mm.

In this test, the demagnetization curve of the hoisting machine using the Alnico 5 series magnet is inclined as shown in Fig. 2, so that the adsorption control voltage range of the iron plate is narrow, and when detaching, two or three 6 mm plates are simultaneously removed. While it is almost impossible to control, the hoisting machine using the Alnico composite magnet of the present invention has a smooth slope of the potato curve so that smooth control is possible at the time of adsorption and desorption. Maintained.

 Since the amount of current to be applied in order to change the polarity of the Sm2Co17 magnet used in the conventional invention is 8000 to 15,000 Oe, the coercive force of the Sm2Co17 magnet is required, so 640 to 950 kA per meter is required. If there is a problem to supply a tremendous power, but the maximum hoisting capacity of 8 tons using the Alnico composite material of the present invention, when using a 4-pole hoisting machine, the hoist using Alnico composite magnet is 220 (V) to 36.4 (A Power saving effect is great as long as it is current.

In addition, in the case of iron plate transfer work, it is possible to adsorb and desorb up to 1 sheet, which is the minimum unit, which is flexible and very convenient.

In addition, it is easy to adsorb or desorb as much as the desired amount (long life) of the steel plate for the simple transfer operation through the adsorption and desorption of heavy materials such as slabs, hot coils, various round rods or reinforcing bar bundles.

Claims (8)

Paul, a ceramic chain that passes magnetic flux well, A fixed magnet made of a permanent magnet attached to the side of the pole, A variable magnet attached to an upper portion of the pole and capable of changing magnetic flux density, In the hoisting magnet, which is attached to the outside of the staging magnet and the variable magnet to form a magnetic path, including a pole, the fixed magnet, and the yoke for coupling and supporting the variable magnet, The variable magnet comprises a core and a solenoid coil wound around the core, and the core is an AlNiCo composite magnet manufactured by superposing a first magnet and a second magnet having different magnetization properties, wherein the core of the variable magnet is a residual magnetic flux. A first magnet made of a material having a high density and a second magnet made of a material having a lower residual magnetic flux density than the first magnet, Potatoes which have a linearly smooth potato with respect to the magnetic force demagnetized by the magnetic flux output from the pole when magnetizing by flowing a current in a forward direction to a coil wound around the core and then demagnetizing a current in a reverse direction. Hoisting magnet characterized by having characteristics The method according to claim 1, The stator magnet is a hoisting magnet, characterized in that the Nd-Fe-B magnet The method according to claim 2, The first magnet is an Alnico5 series magnet, and the second magnet is an Alnico2 series magnet. The method according to claim 2, The first magnet and the second magnet has the same area as the core is to be 1/2 of the core length, The first magnet is an Alnico 5 series magnet having a residual magnetic flux density of 13.5 kG and a coercive force of 800 Oe, The second magnet is a magnet for a hoist, characterized in that the magnetic flux density is 6.5 kG, the Alnico 2 series magnet having a coercive force of 500 Oe A hoist using a permanent magnet, characterized in that the magnet for a hoist according to any one of claims 1 to 4 can be adsorbed or desorbed as many as necessary from a plurality of iron plates. As a magnet for hoist which can configure magnetic circuit with variable magnet, stator magnet, pole and hoist case, and control the amount of magnetic flux generated by variable magnet by winding solenoid coil around the variable magnet, It is a composite alnico magnet composed of a combination of alnico magnets, has a residual magnetic flux density of 10 kG, a coercive force of 700 to 800 Oe, and has a characteristic of almost linearly decreasing the magnetic flux density with respect to the change in magnetic force for potatoes. The magnet for the hoist. delete As a method for controlling the number of hoisting using a magnet having a potato characteristic that is linearly smooth potato according to claim 1, 2, 3, 4 and 6, A method of controlling the number of detachable sheets by applying a voltage corresponding to the number of possible rolls determined according to each potato characteristic value.

Images