KR100954152B1 - Apparatus and method for skip-notching stator core - Google Patents

Abstract

A skip notching device for a stator core according to the present invention is a notching device for a stator core including an upper mold, a lower mold, and a rotating die in which the core is seated and rotated by one step. Punching control bar to move forward and backward, the control groove formed at the front end of the punching control bar, when the upper mold is located in the bottom dead center in the state inserted into the control groove, the perforation does not proceed, the state in contact with the punching control bar When the upper mold is located at the bottom dead center, the punch punched, the input unit for inputting the skip notching number, the control unit for controlling the forward or backward of the forward and backward movement means according to the number of times input from the input unit, and the upper mold And detection means for detecting the number of times located at the bottom dead center.

Description

Apparatus and Method for Skip-Notching Stator Core}

TECHNICAL FIELD This invention relates to the apparatus for notching in the thin steel plate which comprises a stator core. More specifically, the present invention provides a method of fixing holes to be drilled in a thin layer (hereinafter referred to as thin steel sheet) cores that constitute a laminated structure of a stator stack used in a large electric motor or an industrial generator. A skip notching device for a stator core that can be punched at intervals. The invention also includes a method of skip notching a stator core.

General motor manufacturing techniques, in particular the manufacturing techniques for the mutual bonding consisting of cores of several thin steel sheet layers, are well known to those skilled in the art, and those skilled in the art mostly use the same manufacturing techniques. As an exception, optimization steps are used depending on design constraints and manufacturing practices performed by each manufacturer.

For example, a known method for manufacturing a rotor stack is as follows.

The outer stator and the inner rotor are all made up of thin steel sheets stacked in slots, each with a coil in the rotor slot. There is no example where each phase of three phases is one coil, and the number of slots of the rotor is 24, 36, 48, 64… since at least some coils are used. And many hundreds. The coils of each phase are arranged by moving 120 ° in the space. There are two types of rotors called unsealed copper rods or cages in which castings of aluminum are put into slots and windings made of three-phase windings. On the other hand, the stator may be located inside and the rotor may be located outside.

A two-pole electric motor generates a two-pole rotating magnetic field. When the width of the coil is cut in half and the number of coils is doubled, a four-pole rotating magnetic field is generated. By narrowing the width of the coil further, it is possible to make 6 poles, 8 poles, and so on. The larger the number of poles, the slower the rotational magnetic field is, and the speed of the rotor also rotates accordingly.

In addition, when a three-phase voltage is applied to the three-phase winding of the rotor, a three-phase current flows into the rotor to create a magnetic field. The speed Nn becomes 120 f / p revolutions per minute when p is the pole number and f is the frequency. If the rotor is in an electrically closed circuit, current flows and rotates as an electric motor due to electromotive force in the rotor conductor generated by the rotor field.

The direction of rotation is the same as that of the rotating magnetic field, but the speed of the rotor is slower than that of the rotating magnetic field. This difference is called slip, and the value of this slip has a great effect on the operation of the motor. For example, when the slip approaches zero, the output approaches zero. In general, the slip value at the specified output is about a few percent of the rotor speed.

The above is the same whether the rotor is a cage type or a winding type. In general, three-phase induction motors are squirrel-shaped and have four poles, and the speed is almost 1,500 rpm. The squirrel cage motor is suitable for driving at constant speed. The winding type comes out through the collector ring and the brush which the three-phase terminal was installed in the shaft.

By connecting a resistor with an appropriate value to this three-phase terminal, the speed can be controlled, the inrush current at start-up can be reduced, and the torque can be increased. There are many ways to control the speed of a squirrel motor, but it is very difficult to adjust it freely like a DC motor. In addition, the small induction motor is a single phase used with a voltage of 100 or 200 V in a single phase, and examples thereof include a washing machine, a fan, a refrigerator, a pump, and the like. These are all single phase induction motors, output is less than 750W, and stator cages are almost the same as three phase motors.

An example of the configuration on the rotor side is to place the main winding and the auxiliary winding 90 degrees apart from each other. The power supply voltage is applied directly to the main winding and through the capacitor and the switch. The reason for this is that the main winding alone does not start even when a voltage is applied, so that the auxiliary winding is made to create starting torque. Furthermore, by inserting a condenser, the characteristic when starting can be improved. When the stator rotates at high speed after starting, the rotation is continued even without the auxiliary winding, so it is attached to the rotor side.

However, since many holes (holes for winding coils) are formed continuously in the core of a thin steel plate constituting a laminated structure of a rotor stack used in a large electric motor, it is difficult to control the speed of the rotor. In addition, there is a problem that a lot of inrush current at start-up, and torque is also small.

Accordingly, holes need to be formed at regular intervals (skips), and the present inventors propose a skip notching apparatus and method for cores capable of manufacturing a core having such a skipped hole shape.

The present invention provides a method and method for skipping notching a stator core, which improves workability and productivity by punching holes formed in a core of a thin steel sheet forming a laminated structure of a stator stack used in a large electric motor to have a uniform pattern. Its purpose is to provide.

The above object of the present invention can be achieved by the present invention described below.

In the skip notching device of the stator core according to the present invention, in the notching device of the stator core consisting of an upper mold, a lower mold, and a rotating die on which the core is seated and rotates by one step,

A punching adjustment bar installed at one side of the upper mold and moving forward and backward by means of forward and backward movement means;

An adjusting groove formed at one front end of the punching adjusting bar;

If the upper mold is located in the bottom dead center in the state inserted into the adjustment groove is not punched, the punch is punched when the upper mold is in the bottom dead center in contact with the punching adjustment bar;

An input unit to input the skip notching number;

A controller for controlling the forward or backward movement of the forward and backward moving means according to the number of times input by the input unit; And

Detection means for detecting a number of times the upper die is located at the bottom dead center;

Characterized in that consists of.

In the present invention, a taper may be formed on both sides of the adjusting groove to facilitate the operation of the punch.

The front and rear movement means of the present invention may be composed of a solenoid valve which is operated by receiving an electrical signal from the control unit, and a pneumatic cylinder which is operated back and forth by the direction of the pneumatic pressure flowing in accordance with the operation of the solenoid valve.

As an example, the detecting means of the present invention may be a sensor installed at one side of the crankshaft for driving the upper die and detecting the rotation of the crankshaft.

The skip notching method of the stator core according to the present invention,

A first step of inputting a skip notching number to an input unit;

A second step of advancing the punching adjustment bar by the control unit so as to allow perforation of the punch;

A third step in which the upper mold is perforated at the bottom dead center and the rotating die rotates by one step;

A fourth step of detecting the number of perforations by the detection means and repositioning the punching adjustment bar so that the punch is not perforated when the control unit punches the skip notch the number of times;

A fifth step in which the upper die is repeatedly positioned as many times as the skip notching input at the bottom dead center while the punch control bar is backward, and the rotary die rotates by one step at the same time; And

A sixth step of repeating the second to fifth steps until the rotating die is rotated 360 degrees;

Characterized in that consists of.

By punching holes drilled in a core of a thin steel sheet constituting a laminated structure of a stator stack used in a large electric motor or an industrial generator to have a predetermined skip interval, the workability and productivity can be improved. Have

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the present invention.

1 is a cross-sectional view schematically showing a skip notching device according to the present invention, Figures 2 and 3 is a view showing an example of the punching adjustment bar and the front and rear adjustment means of the skip notching device according to the present invention, Figure 2 is a side view 3 is a rear view, and FIG. 4 is a view showing a part of a stator core skip skipped by a skip notching apparatus according to the present invention.

 As shown in Figure 1, the improved stator stack manufacturing apparatus 1 according to the present invention is large, upper mold 10, lower mold 20, rotary die 50, punch 120, punching adjustment bar 110, a forward and backward movement means, a detection means, a control unit 200, and an input unit 400.

The upper mold 10 of the present invention is to move up and down, when the upper mold moves from the top dead center to the bottom dead center so that the punch 120 installed below the upper mold 10 exerts pressure on the lower mold 20. Thus, the holes 41 are punched one by one into the core 40 shown in FIG. 4. The upper mold 10 is generally connected to the rotating crankshaft 30 to drive the vertical movement. Detailed connection relation and structure between the crankshaft and the upper die is obvious to those skilled in the art, so a detailed description thereof will be omitted.

The rotary die 50 rotates by one step with the core 40 seated thereon. As used herein, "step" refers to the spacing between the holes to be drilled in the core, that is, the spacing between adjacent holes and the holes. Therefore, the rotary die 50 rotates by one step during the one-stroke movement of the upper die and serves to move the perforation point of the core. The rotary die 50 may be driven by a servo motor or the like, and since the rotation mechanism is obvious to those skilled in the art, a detailed description thereof will be omitted.

Since the skip notching device according to the present invention is a device for drilling a core used in a large motor or an industrial generator or the like, it takes a method of perforating by rotating by one hole. For example, if the number of holes to be drilled in the core is 36, the rotation angle of one step is 360/36 = 10 degrees.

In the conventional general notching apparatus, it is possible to drill a continuous hole, but the present invention enables a so-called 'skip notching' operation. For example, in the case of the core shown in FIG. 4, five steps of perforations are made and five holes are successively punched, and then five steps are not perforated and perforations are repeated for five subsequent steps. have. As such, the work in which the perforation is not made during a certain step is defined as 'skip notching' in the present specification. Hereinafter, the detailed configuration of the present invention for such skip notching will be described in detail.

Referring back to FIG. 1, the punch 120 connected to the lower portion of the upper mold 10 is punched in a core located in the lower mold 20 when the upper mold 10 reaches the bottom dead center. . The present invention installs a punching adjustment bar 110 to move back and forth on the upper portion of the punch 120, the adjustment groove 111 formed in one end of the punching adjustment bar 110 (see Figs. 2 and 3) is a punching adjustment bar It is configured to be positioned above the punch 120 and moved by the forward and backward movement of the 110. For reference, in the present specification, the 'moving back and forth' direction is defined by the arrow direction shown on the right side of the punch 120 in FIG. 1 as the 'forward' direction, and the opposite direction is used as the 'reverse' direction.

By doing so, when the adjusting groove 111 is located on the upper portion of the punch 120, when the upper die 10 reaches the bottom dead center, the punch 120 does not press the lower die 20 so that punching is not made. Do not. This enables the skip notching operation. On the contrary, when the punching adjustment bar 110 moves forward and the position of the adjustment groove 111 is shifted from the punch 120, when the upper mold 10 reaches the bottom dead center, the upper portion of the punch 120 is a punching adjustment bar ( 120 is supported by the lower mold 20 so that the perforation is made.

Such a punching adjustment bar 120 is moved back and forth by the front and rear movement means installed on one side of the upper mold (10). The forward and backward movement means should be electrically controllable according to the number of skips. In the present invention, the pneumatic cylinder 150 and the solenoid valve 100 connected to the pneumatic cylinder 150 is configured as an example of the front and rear movement means. The back and forth movement of the punching adjustment bar 120 is determined according to the direction of the compressed air flowing into the pneumatic cylinder 150. The direction of the compressed air is controlled by the operation of the solenoid valve 100, the solenoid valve 100 is electrically connected to the control unit 200 of the present invention, the solenoid valve 100 in accordance with the signal of the control unit 200 ) Works. As such, the pneumatic cylinder 150 is operated by the operation of the solenoid valve 100, and accordingly, the punching adjustment bar 110 moves forward and backward.

The input unit 400 of the present invention is electrically connected to the control unit 200 and is a part for inputting the skip notching number, and may be configured using a known means used in the art, such as a dip switch.

In the present invention, the detection means detects one cycle of the upper die 10. As an example for this purpose, the sensor 300 is installed on the crankshaft 30 that drives the vertical movement of the upper mold 10, and detects one rotation of the crankshaft, and sends this signal to the controller 200. As another example, the one-step signal from the servo motor of the rotary die 50 may be directly received by the controller 200 and used.

When the skip notching operation is made through the configuration as described above.

For example, if a skip notching value is input as 5 to the input unit 400, a perforated core may be obtained in the form shown in FIG. 4. When the skip notching value input to the input unit 400 is 5, the control unit 400 operates the solenoid valve 100 to advance the punching adjustment bar 110 by the pneumatic cylinder 150. At this time, since the adjustment groove 111 is not located at the rear of the punch 120, when the upper mold 10 is located at the bottom dead center, it is punched in the core 40 to form a hole 41, and the upper mold 10 is again located at the top dead center. When passing through this one stroke, the sensor 300 installed in the crankshaft 30 detects a perforation once and transmits a signal to the control unit. When the 5 stroke is repeated, the control unit 200 operates the solenoid valve 100 again so that the punching adjustment bar 110 is reversed by the pneumatic cylinder 150. In this state, since the adjustment groove 111 is located at the upper portion of the punch 120, even when the upper mold comes to the bottom dead center, the perforation is not made. That is, skip notching is performed and this number is also detected by the sensor 300. As described above, one step operation of the servo motor (not shown) of the rotary die 50 may be directly transmitted to the control unit by the detection means other than the sensor 300 as an electrical signal.

Meanwhile, the taper 112 may be formed at both ends of the adjustment groove 111 as shown in FIG. 2. Since the adjusting groove 111 is in friction with the punch 120 during the forward and backward movement, it is preferable to form the taper 112 at both ends of the adjusting groove 111 to prevent abrasion due to friction. As another example, the taper 112 may have a rounded surface.

 In the above, the configuration and operation of the skip notching apparatus according to the present invention have been described. Hereinafter, each step of the skip notching method according to the present invention will be described.

 First, the skip notching number is input to the input unit 400. When the skip notching number is input, the controller 200 sends an electrical signal to the solenoid valve 100 to advance the pneumatic cylinder 150 to advance the punching control bar. In this state, punching is possible. That is, when the upper mold is located at the bottom dead center, the punch 120 drills the core and holes are formed. At the same time, the rotating die rotates by one step.

At this time, the number of perforations is detected by the detection means. For example, the sensor 300 installed on the crankshaft detects one rotation of the crankshaft and transmits the signal to the controller. When the received signal reaches the input skip notching number, the control unit moves back the punching adjustment bar 110 so as not to be punched.

In the next step, while the punching adjustment bar is reversed, the upper die is repeatedly positioned at the bottom dead center by the number of skip notching inputs, and at the same time, the rotating die rotates by one step. The number of skip notchings is similarly detected by the detecting means.

This notching and skip notching operation is performed repeatedly until the rotating die is rotated 360 degrees.

As described above, simple modifications or changes of the skip notching device and the skip notching method according to the present invention can be easily performed by those skilled in the art, and all such modifications or changes are included in the scope of the present invention. It can be seen as.

1 is a schematic cross-sectional view of a skip notching apparatus according to the present invention.

2 and 3 is a view showing an example of the punching adjustment bar and the front and rear adjustment means of the skip notching device according to the present invention, Figure 2 is a side view, Figure 3 is a rear view.

4 is a view showing a part of the stator core skip skip operation by the skip notching device according to the present invention.

<Brief description of the major symbols in the drawings>

1: skip notching device 10: upper mold

20: lower mold 30: crankshaft

40: core 41: hole

50: rotary die 100: solenoid valve

110: punching adjustment bar 111: adjustment groove

112: taper 150: pneumatic cylinder

200: control unit 300: sensor

400: input unit

Claims (5)

In the notching device of a stator core consisting of an upper mold, a lower mold, and a rotating die in which the core is seated and rotated by one step, A punching adjustment bar installed at one side of the upper mold and moving forward and backward by means of forward and backward movement means; An adjusting groove formed at one front end of the punching adjusting bar; If the upper mold is located in the bottom dead center in the state inserted into the adjustment groove is not punched, the punch is punched when the upper mold is in the bottom dead center in contact with the punching adjustment bar; An input unit to input the skip notching number; A controller for controlling the forward or backward movement of the forward and backward moving means according to the number of times input by the input unit; And Detection means for detecting a number of times the upper die is located at the bottom dead center; Skip notching device of the stator core comprising a. The skip notching apparatus of the stator core according to claim 1, wherein a taper is formed on both sides of the adjusting groove to facilitate the operation of the punch. According to claim 1, wherein the front and rear movement means is a solenoid valve which is operated by receiving an electrical signal from the control unit; And Pneumatic cylinder which is operated back and forth by the direction of the pneumatic pressure flowing in accordance with the operation of the solenoid valve; Skip notching device of the stator core comprising a. 2. The skip notching device according to claim 1, wherein the detection means is a sensor provided on one side of a crank shaft for driving the upper die and detecting the rotation of the crank shaft. A first step of inputting a skip notching number to an input unit; A second step of advancing the punching adjustment bar by the control unit so as to allow perforation of the punch; A third step in which the upper mold is perforated at the bottom dead center and the rotating die rotates by one step; A fourth step of detecting the number of perforations by the detection means and repositioning the punching adjustment bar so that the punch is not perforated when the control unit punches the skip notch the number of times; A fifth step in which the upper die is repeatedly positioned as many times as the skip notching input at the bottom dead center while the punch control bar is backward, and the rotary die rotates by one step at the same time; And A sixth step of repeating the second to fifth steps until the rotating die is rotated 360 degrees; Skip notching method of the stator core comprising a.

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