KR20240014284A - Stator core induction heating apparatus of drive motor - Google Patents

Abstract

The present invention relates to an induction heating device for the stator core of a drive motor for an electric vehicle, which can improve insulation performance by increasing the impregnation of the varnish by heating the core by induction heating when coating varnish on the copper wire wound on the stator core. , an induction heating unit that heats the inside of the stator core to harden the varnish coated on the copper wire, an induction power supply unit that is electrically connected to the induction heating unit to supply power, and is connected to the induction heating unit. It is characterized by including a cooler that supplies cooling water to the induction heating unit.

Description

Stator core induction heating device for drive motor {STATOR CORE INDUCTION HEATING APPARATUS OF DRIVE MOTOR}

The present invention relates to an induction heating device for the stator core of a drive motor. More specifically, when coating a varnish on a copper wire wound on a stator core, the core is heated by induction heating to improve insulation performance by increasing the impregnation of the varnish. This relates to a stator core induction heating device for a drive motor for an electric vehicle.

Recently, active research and development is being conducted on automobiles that use combustion engines and on other types of automobiles that are environmentally friendly and fuel efficient, such as hybrid automobiles or electric automobiles.

Hybrid cars drive the vehicle with two power sources by linking a conventional engine and a motor driven by electric energy, while electric cars are driven only by a motor driven by electric energy, thereby reducing environmental pollution caused by exhaust gases. Due to the effect of improving fuel efficiency, it has established itself as a next-generation alternative vehicle that has recently been in the spotlight, especially in the United States and Japan.

These hybrid vehicles and electric vehicles are equipped with a high-capacity battery as a driving source for driving the electric motor, which supplies power to the motor when necessary and charges the battery with electrical energy generated from the regenerative power source when the vehicle decelerates or stops. .

Such an electric motor for a vehicle can be largely composed of a rotor equipped with a plurality of magnetic materials such as permanent magnets, a stator that generates electromagnetic force to rotate the rotor, and a motor housing that supports the rotating operation of the rotor and the stator. there is.

Here, motor bearings are mounted on both sides of the motor housing to rotate and support the rotor.

Specifically, looking at the function of the motor bearing, the motor bearing enables rotational movement of the rotor using the force generated by the electromagnetic force between the stator and the rotor, and supports and maintains the rotor in the radial direction. This maintains the air gap in the radial distance between the stator and the rotor, and measures the rotation position by positioning the resolver stator fixed to the resolver rotor and housing cover of the rotor in the axial direction to provide a motor rotation control signal. make it happen

Figure 1 is a photograph showing a part of the stator core of a conventional square copper wire winding motor, and Figure 2 is a partial radial cross-sectional view showing the shape of the core slot of the conventional stator core. As shown in Figures 1 and 2, slot insulating paper 14 is essential to secure insulation performance before the hairpins 16 are inserted into the core slot 12 of the stator core 10. .

However, the stator structure of such a conventional copper square wire winding motor is excessively bent in the process of forming the copper square wire 16, as shown in FIG. 1, so the insulation performance is lower than that of the general distributed winding method, and copper square wire is used for insulation. There is a manufacturing difficulty in that the spacing (A) of (16) must be kept constant, and the angular copper wires (16) are arranged irregularly due to the slight empty space (B) as shown in Figure 2, resulting in angular copper wires ( 16) There is a problem that the spacing (A) between them is difficult to keep constant. In addition, there is a drawback in that productivity is reduced because the slot insulating paper has to be coated on the surface of the stator core and then waited for it to harden.

Republic of Korea Patent Publication No. 10-2013-0119098

Therefore, the present invention was devised to solve the above-mentioned problems, and its purpose is to heat the stator core to a desired temperature in a short period of time by heating the stator core using an induction heating method when coating the varnish on the copper wire of the stator core. The aim is to provide a stator core induction heating device for a drive motor that can improve core quality and productivity.

An induction heating device for the stator core of a drive motor according to an embodiment of the present invention to achieve the above object includes an induction heating unit that heats the inside of the stator core to harden the varnish coated on the copper wire, and the induction heating unit It may include an induction power supply unit that is electrically connected to the heating unit to supply power, and a cooler that is connected to the induction heating unit and supplies cooling water to the induction heating unit.

The induction heating unit is connected to the induction power supply and generates a high-frequency induction current, and includes an induction current generator connected to the induction current generator, a support bar connected to the induction current generator, and wound around the support bar to generate an induction current generated by the induction current generator. It may include an induction heating coil for preheating and hardening the varnish supplied and coated on each copper wire.

The induction heating coil can control the temperature balance of varnish molding by adjusting the number of turns and spacing around the support bar.

The high-frequency induction current generated from the induction heating unit can preheat the stator core to 55°C to 65°C before coating the copper wire with varnish.

The induction heating unit may allow a pause time without generating an induction current after the primary heating and after the secondary heating to reduce the temperature deviation of the stator core and achieve thermal balance.

A rotating part that rotates the stator core may be installed on the outside of the stator core so that it is heated to a uniform temperature when heated by an induction current generated in the induction heating part, thereby increasing the varnish impregnation efficiency.

As described above, according to the stator core induction heating device for the drive motor according to the present invention, when varnish is coated on the surface of each copper wire wound on the stator core, an induction heating unit is placed inside the stator core to heat the stator core through an induced current. Induction heating can improve the insulation performance by increasing the impregnation of the varnish.

Figure 1 is a photograph showing a part of the stator core of a conventional square copper wire winding motor.
Figure 2 is a partial radial cross-sectional view showing the shape of the core slot of a conventional stator core.
Figure 3 is an overall configuration diagram showing the stator core induction heating device of a drive motor according to the present invention.
Figure 4 is a perspective view showing the induction heating portion of the stator core induction heating device of the drive motor according to the present invention.
Figure 5 is a front view showing the induction heating unit according to Figure 4.
Figure 6 is a side view showing the induction heating unit according to Figure 4.
Figure 7 is a side view showing another example of an induction heating unit according to the present invention.
Figure 8 is a side view of the rotating part for rotating the stator core of the stator core induction heating device of the drive motor according to the present invention combined.
Figure 9 is a thermal image image of heating the stator core of the drive motor according to the present invention with the stator core induction heating device.

Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

In the drawings, embodiments of the present invention are not limited to the specific form shown and are exaggerated for clarity. Although specific terms are used in this specification, they are used for the purpose of describing the present invention, and are not used to limit the meaning or scope of rights of the present invention described in the claims.

In this specification, the expression 'and/or' is used to mean including at least one of the components listed before and after. Additionally, the expression 'connected/coupled' is used to include being directly connected to another component or indirectly connected through another component. In this specification, singular forms also include plural forms unless specifically stated in the phrase. Additionally, elements, steps, operations and elements referred to as 'comprise' or 'comprising' as used in the specification mean the presence or addition of one or more other components, steps, operations and elements.

Additionally, expressions such as 'first, second', etc. are expressions used only to distinguish a plurality of components and do not limit the order or other characteristics between the components.

In the description of the embodiments, each layer (film), region, pattern or structure is “on” or “under” the substrate, each side (film), region, pad or pattern. The description of being formed in "includes being formed directly or through another layer. The standards for top/top or bottom/bottom of each floor are explained based on the drawing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

Figure 3 is an overall configuration diagram showing the stator core induction heating device for a drive motor according to the present invention, Figure 4 is a perspective view showing the induction heating portion of the stator core induction heating device for a drive motor according to the present invention, and Figure 5 is a It is a front view showing the induction heating unit according to FIG. 4, FIG. 6 is a side view showing the induction heating unit according to FIG. 4, FIG. 7 is a side view showing another example of the induction heating unit according to the present invention, and FIG. 8 is a side view showing another example of the induction heating unit according to the present invention. It is a side view of the rotating part for rotating the stator core of the stator core induction heating device of the driving motor according to the invention, and Figure 9 is a thermal image image of heating the stator core with the stator core induction heating device of the driving motor according to the present invention. am.

The stator core induction heating device for a drive motor according to the present invention serves to coat the varnish (V) for insulation on the copper angle wire (2) wound within the stator core (1) of a drive motor used in electric vehicles, etc. At this time, the rectangular copper wire (2) wound inside the stator core (1) may be wound with a thick rectangular wire in a hairpin manner. In addition, the rectangular copper wire (2) manufactured in the shape of a hairpin is inserted into the stator core (1). It can be wound by welding one end.

3 to 9, the stator core induction heating device of the drive motor according to the present invention includes an induction heating unit 100 that heats the stator core 1 using induction heating, and the induction heating unit 100. It may include an induction power supply unit 200 that supplies power, and a cooler 300 that cools the induction heating unit 100.

The induction heating unit 100 is connected to the inside of the stator core 1 and can harden the varnish V coated on the square copper wire 2 wound inside the stator core 1 through induction heating. Meanwhile, at least one induction heating unit 100 can be installed to simultaneously heat a plurality of stator cores 1.

4 to 6, the induction heating unit 100 may include an induction current generator 110, a support bar 120, and an induction heating coil 130.

The induced current generator 110 is electrically connected to the inductive power supply unit 200 to generate a high-frequency induced current. The induced current generator 110 is preferably a device that generates an induced current according to the capacity of the stator core 1.

The support bar 120 is connected to the front of the induction current generator 110 and can support the induction heating coil 130 that receives the induction current generated by the induction current generator 110. Additionally, the support bar 120 may have a straight shape or an 'L' shape as shown in FIG. 7 depending on the installation of the stator core 1.

The induction heating coil 130 is wound around the support bar 120 and connected to the induction current generator 110 and the induction current supply pipe 140, so that the induction current generated by the induction current generator 110 is connected to the induction current supply pipe 140. It is possible to cure the varnish (V) coated on the square copper wire (2) by heating the stator core (1). At this time, the induction current generated from the induction heating coil (130) is generated in the square copper wire (2). Heat is generated directly, so no heat is generated in the induction heating coil 130 itself. That is, the induction heating coil 130 is inserted into the square copper wire 2 inside the stator core 1, and the supplied induction current is The copper wire (2) is heated to harden the varnish (V).

In addition, the induction heating coil 130 can control the overall temperature balance of varnish (V) molding by adjusting the number of turns and the spacing of the induction heating coil 130 around the support bar 120.

Conditions for forming the varnish (V) by preheating and heating the stator core (1) using induction heating through the induction heating unit (100) are shown in Table 1 below.

Stator core preheating and heating cycle time hour detail temperature 60 seconds Preheat 60℃ 10 minutes varnish injection 1 minute 40 seconds primary heating 120℃ 10 seconds downtime 30 seconds secondary heating 150℃ 10 seconds downtime 30 seconds 3rd heating 170℃

As shown in Table 1 above, varnish (V) is injected into the square copper wire (2) with a high-frequency induction current supplied through the induction heating coil (130) of the induction heating unit (100) to heat the stator core (2) before coating by 55%. After preheating to ℃ ~ 65℃, varnish (V) is injected. In this way, by preheating the stator core 1 before injecting the varnish V, the impregnability of the varnish V can be improved.

Thereafter, as shown in FIG. 9, the varnish (V) is injected and heated in 1st, 2nd, and 3rd stages to approximately 170°C, a temperature at which the varnish (V) hardens. At this time, after the primary heating and secondary heating, an induced current is not generated and a pause time is provided to allow time for thermal equilibrium.

In this way, a pause is provided between each heating of the stator core 1 to prevent induced current from being generated, thereby creating a temperature deviation and achieving thermal balance, thereby allowing the varnish V to be evenly coated throughout.

The induction power supply unit 200 is electrically connected to the induction heating unit 100 and supplies power. At this time, since the induction power supply unit 200 is already widely used, a detailed description thereof will be omitted.

The cooler 300 is connected to the induction power supply unit 200 and to the induction heating unit 100 to supply cooling water to the induction heating unit 100 to prevent damage due to deterioration.

On the outside of the stator core 1, when the stator core 1 is heated by the induction current generated in the induction heating unit 100, the stator core is heated to a uniform temperature to increase the varnish (V) impregnation efficiency. A rotating part 400 that rotates (1) may be installed. The rotating part 400 surrounds the outside of the stator core 1 and rotates as the motor M is driven to rotate the stator core 1.

Meanwhile, the stator core 1 may be equipped with an infrared thermometer 500 to inspect the temperature of the stator core 1 preheated through the induction heating unit 100. In addition, a monitoring unit 600 may be provided to monitor data transmitted to and received from the infrared thermometer 500 and measured by the infrared thermometer 500 in real time.

The operation status according to the stator core induction heating device of the drive motor of the present invention composed of the above device is as follows.

The surface of the square copper wire (2) wound inside the stator core (1) may be coated with varnish (V) for insulation. In order to coat the varnish (V) on the copper angle wire (2), the stator core (1) is preheated and heated to harden the varnish (V) on the copper angle wire (2).

Accordingly, the induction heating coil 130 is charged into the inside of the square copper wire 2 wound on the stator core 1 and the induction current generator 110 is operated to generate high frequency and induction heating through the induction current supply pipe 140. The induced current transmitted to the coil 130 is transmitted to the angle copper wire 2 to preheat and heat the stator core 1.

At this time, with the induction heating coil 130 inserted into the square copper wire 2 of the stator core 1, the induction heating coil 130 is used before injecting the varnish V into the square copper wire 2. After preheating the stator core (1) to a certain temperature with electric current, varnish (V) is injected, the stator core (1) is heated to a certain temperature, and the varnish (V) is hardened and coated on the square copper wire (2) to form a varnish. The impregnation efficiency of (V) can be increased. In addition, when the stator core 1 is preheated through the induction heating coil 130 and then heated to a certain temperature to cure the varnish (V), a pause time during which induction current is not supplied after the first and second heating is required. As a result, thermal balance is achieved throughout the copper wire (2), so that the varnish (V) can be formed smoothly.

In addition, by rotating the stator core 1 with the rotating unit 400, the stator core 1 can be heated to a more uniform temperature, thereby improving the impregnation efficiency of the varnish V.

In this way, when coating the varnish (V) on the square copper wire (2) of the stator core (1), the stator core (1) is heated using induction heating by the induction heating unit (100), thereby heating the stator core (1). It can be heated in a short time, accurate temperature control is possible, and it is possible to maintain a certain time and temperature, thereby increasing work efficiency and molding efficiency of varnish (V).

In the above detailed description of the present invention, only special embodiments thereof have been described. However, it should be understood that the present invention is not limited to the particular form mentioned in the detailed description, but rather is understood to include all modifications, equivalents and substitutes within the spirit and scope of the present invention as defined by the appended claims. It has to be.

That is, the present invention is not limited to the specific embodiments and descriptions described above, and various modifications may be made by anyone skilled in the art without departing from the gist of the present invention as claimed in the claims. is possible, and such modifications fall within the scope of protection of the present invention.

1: stator core 2: square copper wire
100: induction heating unit 110: induction current generator
120: support bar 130: induction heating coil
140: Inductive current supply pipe 200: Inductive power supply unit
300: Cooler 400: Rotating unit
500: Infrared thermometer 600: Monitoring unit

Claims (6)

An induction heating unit that heats the inside of the stator core to harden the varnish coated on each copper wire;
an induction power supply unit electrically connected to the induction heating unit to supply power; and
A stator core induction heating device for a drive motor comprising a cooler connected to the induction heating unit and supplying cooling water to the induction heating unit. According to claim 1,
The induction heating unit,
an induced current generator connected to the inductive power supply to generate a high-frequency induced current;
A support bar connected to the induced current generator; and
An induction heating coil connected to the induction current generator, wound around a support bar, supplied with an induction current generated by the induction current generator, and used to preheat and harden the varnish coated on each copper wire. A stator core induction heating device for a drive motor comprising a. According to claim 2,
The induction heating coil is a stator core induction heating device for a drive motor, characterized in that the temperature balance of varnish molding is adjusted by adjusting the number of turns and spacing around the support bar. The method of claim 1 or 2,
A stator core induction heating device for a drive motor, characterized in that the stator core is preheated to 55°C to 65°C before coating the angle copper wire with varnish using a high-frequency induction current generated in the induction heating unit. The method of claim 1 or 2,
The induction heating unit is a stator core induction heating device for a drive motor, characterized in that the induction heating unit does not generate an induced current and provides a rest time after the first heating and the second heating to reduce the temperature deviation of the stator core and achieve thermal balance. According to claim 1,
Stator core induction of a drive motor, characterized in that a rotating part is installed on the outside of the stator core to rotate the stator core so that it is heated to a uniform temperature when heated by the induction current generated from the induction heating part and thus increases the varnish impregnation efficiency. Heating device.

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