JP2006246560A - Rotor manufacturing method of permanent magnet motor and curing degree prediction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor manufacturing method of a permanent magnet motor that can make a permanent magnet firmly adhere to a magnet storage hole formed at a rotor without causing the leakage of an adhesive to the outside, when adhesion-fixing the permanent magnet to the magnet storage hole formed at the rotor, can set a curing condition, and can shorten a manufacturing time of the rotor, and a curing degree prediction method. <P>SOLUTION: The rotor manufacturing method comprises: an adhesive injection step that injects the adhesive into a slot formed at a rotor core; a magnet insertion step that inserts the permanent magnet into the slot; an installation step that superimposes and fixes an end plate on the rotor core and blocks the slot; an inverting preheating step that holds the rotor at a temperature higher than a normal temperature and lower than the curing start temperature of the adhesive in a state that the top and the bottom of the rotor are inverted different form a state in the adhesive injection step; an erecting preheating step that holds the rotor at a preheating temperature by returning the top and the bottom of the rotor back to the same state in the adhesive injection step; and a thermosetting step that thermally cures the adhesive in the slot by heating the rotor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a rotor of a permanent magnet motor including a permanent magnet, and a curing degree prediction method used in the manufacturing method for predicting the curing degree of an adhesive. More specifically, the present invention relates to a method for manufacturing a rotor of a permanent magnet motor and a method for predicting the degree of cure by bonding and fixing a permanent magnet in a storage hole provided in the rotor core.

  For example, there is a permanent magnet type rotor manufactured by providing a magnet housing hole in a rotor core formed of laminated steel sheets or the like and inserting and fixing a permanent magnet therein. In such a rotor, as a conventional method for fixing a magnet, for example, there is a method in which an adhesive is injected into a magnet housing hole provided in a rotor core and a permanent magnet is inserted into the magnet housing hole for adhesion. is there. Furthermore, in order to arrange the permanent magnet at an appropriate position in the magnet housing hole, various devices have been devised in the shape of the housing hole (see, for example, Patent Document 1 and Patent Document 2).

  Further, in such a rotor, it is also important to increase the bonding area of the adhesive. Therefore, the present inventor proposed in an earlier application (see Japanese Patent Application No. 2004-119934) that an adhesive and a magnet are inserted into a magnet housing hole, and then the core is turned upside down and cured. According to this method, the adhesive accumulated in the lower part of the magnet housing hole can be attached to the upper part along the magnet, so that a strong and uniform adhesive state can be obtained. In addition, the application incorporates a pre-heating process that heats the adhesive to an extent that it does not cure, and improves the fluidity of the adhesive and turns the core up and down to spread the adhesive along the magnet before the curing process. I also proposed that.

In addition, when using adhesives, it is important to understand the curing conditions in the thermosetting process. Conventionally, as an adhesive curing condition, an adhesive manufacturer generally presents a standard curing condition in the form of a curing temperature and a holding time at the temperature. That is, it is a condition that if it is kept at a predetermined temperature for a predetermined time, it is almost cured. However, in the actual process, it takes time to raise the temperature from room temperature to the specified temperature and the cooling time after curing. Therefore, the setting that reliably includes the curing conditions recommended by the manufacturer takes too much time for the thermosetting process. . For this reason, we have sought a method for shortening the processing time by conducting curing experiments under various conditions and examining the cured state of the adhesive.
JP-A-5-207692 JP 2001-352702 A

  However, the conventional rotor manufacturing method described above has the following problems. When the preheating process is performed by reversing the top and bottom of the core as previously proposed by the present inventor, the bubbles generated in the adhesive are located at the bottom of the magnet housing hole (disposed above during the preheating process). It collects in. After that, if the thermosetting process was performed immediately after returning the top and bottom of the core, hardening might start before the bubbles could rise above the magnet housing hole. For this reason, the bubbles are expanded by heat while remaining in the vicinity of the central portion of the magnet housing hole, and the adhesive around the bubbles may be pushed out from between the laminated surfaces of the core and leak to the outside. In particular, when the sealing degree at both ends in the core stacking direction is high, the bubble moving speed becomes slow, and this phenomenon tends to occur.

  In addition, if a preheating process is added to the rotor manufacturing process, the time required for the entire permanent magnet bonding process is increased accordingly. For this reason, there is a problem that the manufacturing time of the rotor as a whole becomes long. In addition, it became more difficult to predict the curing conditions, and it was necessary to conduct a curing test with a large number of test pieces. Therefore, there is a problem that setting the curing conditions takes time and labor.

  The present invention has been made to solve the above-described problems of the prior art. That is, the problem is that when the permanent magnet is bonded and fixed to the magnet housing hole formed in the rotor, the adhesive can be firmly bonded without leaking to the outside, and the setting of the curing conditions and the manufacturing time of the rotor can be shortened. An object of the present invention is to provide a method for manufacturing a rotor of a permanent magnet motor and a method for predicting the degree of cure.

  In order to solve this problem, the rotor manufacturing method of the permanent magnet motor of the present invention includes an adhesive injection process for injecting an adhesive into a slot formed in the rotor core, and a magnet for inserting the permanent magnet into the slot. A method for manufacturing a rotor of a permanent magnet motor, comprising: an insertion step; an attachment step in which an end plate is stacked and fixed on a rotor core to close the slot; and a thermosetting step in which the adhesive in the slot is thermally cured by heating the rotor. The rotor is maintained at a preheating temperature higher than normal temperature and lower than the adhesive curing start temperature, with the rotor upside down as compared with the adhesive injection process between the mounting process and the thermosetting process. Erecting preheating process to maintain the rotor at the preheating temperature by returning the top and bottom of the rotor to the same state as in the adhesive injection process. And it has a door.

  According to the method for manufacturing a rotor of a permanent magnet motor of the present invention, since the inverted preheating step is provided after the mounting step, the adhesive is spread along the permanent magnet. Furthermore, since it has an erecting preheating process, bubbles generated in the adhesive are moved upward. Therefore, even if the bubbles are thermally expanded in the thermosetting process, they are easily pushed out and there is no possibility of pushing out the adhesive. Thus, when the permanent magnet is bonded and fixed to the magnet housing hole formed in the rotor, the rotor manufacturing method of the permanent magnet motor can be firmly bonded without leakage of the adhesive to the outside.

The method of manufacturing a rotor of a permanent magnet motor according to the present invention includes an adhesive injection step of injecting an adhesive into a slot formed in the rotor core, a magnet insertion step of inserting a permanent magnet into the slot, and an end plate on the rotor core. A method of manufacturing a rotor of a permanent magnet motor, comprising: an attaching step for fixing the two layers and closing the slot; and a thermosetting step for thermosetting the adhesive in the slot by heating the rotor. There is a preheating process in which the rotor is maintained at a preheating temperature higher than normal temperature and lower than the curing start temperature of the adhesive between the processes, and the upper and lower sides of the rotor are reversed from the previous stage of the preheating process. The latter stage of the preheating step may be performed by returning the upper and lower portions of the rotor to the same state as in the adhesive injection step.
Even in this case, the same effect as described above can be obtained.

Further, in the present invention, it is desirable that the thermosetting process is performed at a temperature higher than the curing start temperature of the adhesive, and the top and bottom of the rotor are in the same state as in the adhesive injection process.
In this way, even when the rotor is set to a temperature higher than the curing start temperature, the adhesive does not leak to the outside.

Further, in the present invention, the thermosetting process is performed by integrating the square of the temperature value × the first coefficient + the temperature value × the second coefficient + the third coefficient over a period in which the rotor temperature is equal to or higher than the curing start temperature of the adhesive. It is desirable to carry out with a temperature pattern in which the value is equal to or greater than the determination threshold value.
In this way, an appropriate temperature pattern in the thermosetting process can be easily predicted. Therefore, it is not necessary to perform many curing experiments, and the time required for setting the curing conditions and manufacturing the rotor can be shortened.

  The present invention also relates to a curing degree prediction method for predicting the degree of curing of the adhesive in the thermosetting process in which the adhesive in the slot is thermally cured by heating the rotor, and the temperature of the rotor is bonded to the adhesive. The integrated value of the square of the temperature value x first coefficient + temperature value x second coefficient + third coefficient over a period that is equal to or higher than the curing start temperature of the agent is compared with the determination threshold value, and the integrated value is determined. If the threshold value is not less than the threshold value, it is determined that the curing is sufficient.

  According to the method for manufacturing a rotor of a permanent magnet motor and the method for predicting the degree of hardening of the present invention, when the permanent magnet is bonded and fixed to the magnet housing hole formed in the rotor, the adhesive can be firmly bonded without leaking to the outside and cured. Setting conditions and manufacturing time of the rotor can be shortened.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best mode for embodying the present invention will be described in detail with reference to the accompanying drawings. In this embodiment, the present invention is applied to a method of manufacturing an inner rotor of a motor.

  As shown in FIGS. 1 and 2, the rotor 1 used in this embodiment has a flange 11a extending radially outward from a central rotor shaft 11, and a core receiver 11b having an L-shaped cross section is formed at the tip thereof. Yes. A ring-shaped magnet end 12 is attached to the lower step portion of the core receiver 11b, and a rotor core 13 in which a plurality of electromagnetic steel plates 13a are stacked is provided. Further, holes are formed at the same positions in the respective electromagnetic steel sheets 13a, and the slots 14 are formed by overlapping the holes. A permanent magnet 16 is fixed inside the slot 14 by an adhesive 15. Here, as shown in FIG. 1, since the slot 14 is formed slightly wider than the permanent magnet 16, an adhesive column 14 a is formed on the side of the permanent magnet 16.

  Further, as shown in FIG. 2, an end plate 17 is overlaid on the upper side of the rotor core 13 in the figure, and the rotor core 13 is covered. Further, the thin steel plates 18 and 19 are stacked in contact with both ends of the electromagnetic steel plate 13a in the stacking direction, and both ends of the slot 14 are closed. Here, both the magnet end 12 and the end plate 17 are made of aluminum or the like, and are formed of a material having a higher coefficient of thermal expansion than the rotor core 13. On the other hand, the thin steel plates 18 and 19 are made of SUS or the like and have substantially the same thermal expansion coefficient as that of the rotor core 13. Further, the both surfaces of the thin steel plates 18 and 19 are coated with a fluororesin so that the adhesive between the thin steel plates 18 and 19 and the rotor core 13 by the adhesive 15 is prevented. The adhesive 15 used here is, for example, an epoxy adhesive 15. In FIG. 1, the end plate 17 and the thin steel plate 18 are omitted.

  Next, a method for manufacturing the rotor 1 of this embodiment will be described. This manufacturing method is performed according to the following procedure. First, the assembly process of the rotor 1 shown in FIG. 3 is performed. Next, the inverted preheating process shown in FIG. 4 is performed. Next, an upright preheating process shown in FIG. 5 is performed. Finally, the thermosetting process shown in FIG. 6 is performed. Hereafter, each process is demonstrated one by one.

  First, the assembly process of the rotor 1 will be described with reference to FIG. In the assembly process, as shown in FIG. 3A, the magnet end 12, the thin steel plate 19, and the plurality of electromagnetic steel plates 13 a are fitted into the core receiver 11 b of the rotor shaft 11 to form the rotor core 13. Further, a predetermined amount of adhesive 15 is injected into the slot 14. Then, the permanent magnet 16 is inserted into the slot 14.

  Next, as shown in FIG. 3B, the end plate 17 is attached. The end plate 17 is a ring-shaped thick plate, and the inner peripheral side thereof is chamfered to form a wedge-shaped caulking portion. In this step, the thin steel plate 18 and the end plate 17 are stacked on the laminated electromagnetic steel plates 13a, and the upper end portion of the core receiver 11b is bent and crimped by a mandrel 20 or the like. As a result, the slot 14 filled with the adhesive 15 is hermetically closed by the thin steel plates 18 and 19. In this state, the adhesive 15 has accumulated in a relatively lower portion in the slot 14 and has not yet been cured. Thus, the assembly process of the rotor 1 is completed. This assembly process is the same as the conventional process.

  Next, the inverted preheating process will be described with reference to FIG. This process is for spreading the adhesive 15 in the slot 14 over a wide range. Therefore, first, as shown in FIG. 4A, the assembled rotor 1 is turned upside down and held at the preheat temperature. That is, the rotor 1 turned upside down from the state in the previous assembly process is placed in the constant temperature enclosure 21, and the inside of the constant temperature enclosure 21 is heated by the heater 22. Here, the heating temperature in the constant temperature enclosure 21 is set to about 40 to 80 ° C., and the heating process is performed for about 30 minutes.

  In this process, since the end plate 17 is made of aluminum, the end plate 17 is thermally expanded as compared with the rotor core 13. Here, the end plate 17 is formed so that the outer peripheral side thereof is in close contact with the rotor core 13. Therefore, as shown in FIG. 4B, the inner peripheral side of the rotor 1 is slightly lifted by this thermal expansion. FIG. 4B is a cross-sectional view seen in the direction along the permanent magnet 16, and the left side in the figure is the inner peripheral side of the rotor 1. On the other hand, a thin steel plate 18 is inserted between the end plate 17 and the rotor core 13, and a thin steel plate 19 is inserted between the magnet end 12 and the rotor core 13, and these have a thermal expansion coefficient substantially equal to that of the rotor core 13. Therefore, the airtightness of the slot 14 is maintained by the thin steel plates 18 and 19. Therefore, the adhesive 15 does not leak out of the slot 15 even if it is reversed in this way.

  This preheating temperature is a temperature at which the curing of the adhesive 15 does not start and a temperature at which the viscosity of the adhesive 15 decreases. Therefore, as shown in FIG. 4B, the adhesive 15 flows and moves downward in the slot 14 due to gravity (that is, above the slot 14 in the normal position). And it spreads evenly in the gap between the inner wall of the slot 14 and the permanent magnet 16. At this time, bubbles may be formed inside the adhesive 15. In particular, it occurs remarkably in the column 14a. During the inverted preheating process, the bubbles rise inside the adhesive 15 and reach the vicinity of the thin steel plate 19 as shown in FIG.

  When this inverted preheating process is completed, an upright preheating process is performed next. That is, the rotor 1 is turned upside down again and held at the preheat temperature as shown in FIG. The preheating temperature condition is the same as that of the inverted preheating step of FIG. Therefore, here, after the inverted preheating process, it is only necessary to reverse the rotor 1 upside down while keeping the holding temperature unchanged. Thereby, as shown in FIG. 5 (b), the bubbles in the adhesive 15 rise again and gather in the vicinity of the thin steel plate 18.

  Next, a thermosetting process is performed as shown in FIG. Here, three heaters 22 installed on the upper and lower sides and the outer peripheral side of the rotor 1 are used, and heating is performed at a temperature of about 200 ° C. The rotor 1 remains in the normal position. Again, there is no need to lower the holding temperature from the erecting preheating step of the previous step, and heating may be performed as it is. The adhesive 15 in the slot 14 spreads over the entire permanent magnet 16 by the previous inverted preheating process and erecting preheating process, and quickly loses fluidity by this heating. Therefore, the spread adhesive 15 does not come down again.

  Bubbles generated in the adhesive 15 are accumulated in the upper portion of the slot 14 as shown in FIG. 5B by the upright preheating process of the previous stage. A portion of it escapes from the slot 14 by further heating here. Further, as shown in FIG. 6B, even if the thermal expansion is performed while remaining in the upper portion of the slot 14, the adhesive 15 is not pushed out from the rotor core 13 at this position. Therefore, since the adhesive 15 is cured in a state where it spreads over the entire surface of the permanent magnet 16 without leaking to the outside, the adhesive 15 can be firmly bonded. The rotor 1 is completed when the adhesive 15 is cured.

  Next, the time required for the thermosetting process, which is the final process, will be described. As mentioned in the background art, the adhesive manufacturer provides standard curing conditions in the form of curing temperature and holding time at that temperature. For the epoxy adhesive 15 used in this embodiment, standard curing conditions of, for example, 120 ° C. for 60 minutes or 150 ° C. for 30 minutes are proposed. In contrast, in the manufacturing method of the present embodiment, first, heating is performed from a normal temperature state or a preheating temperature, and the temperature is increased to about 200 ° C., which is the upper limit of heating of the rotor 1, exceeding the curing start temperature of the adhesive 15. After that, it is allowed to cool for a predetermined time. After that, the process is carried out according to the procedure of cooling to room temperature by forced cooling.

Here, the present inventor has found that the retention time can be approximately expressed by a quadratic function of the retention temperature by plotting the curing conditions of the adhesive according to the retention temperature and the retention time (see FIG. 7). From this, it was found that the degree of curing of the adhesive can be approximated fairly well by the left side P1 of the following equation.
P1 = ∫ (α × Ti ² + β × Ti + γ)
Here, Ti is the temperature of the adhesive, and α, β, and γ are experimentally determined constants. The integration is performed over a period in which the temperature Ti is equal to or higher than the curing start temperature of the adhesive. Actually, the integrated value P2 may be obtained by the following equation by measuring the temperature at an appropriate sampling interval.
P2 = Σ (α × Ti ² + β × Ti + γ)

  In the adhesive 15 used this time, the curing start temperature was 120 ° C. When the sampling interval was 1 minute, α was 0.00121, β was −0.29543, and γ was 19.1. When the manufacturer standard curing conditions described above were applied, P2 = 64.3 (120 ° C. for 60 minutes) and P2 = 60.3 (150 ° C. for 30 minutes). Therefore, in the adhesive 15 of this embodiment, the determination threshold value is set to 60, and it is determined that the curing is sufficient if the temperature pattern satisfies P2 ≧ 60. As an example of a temperature pattern that satisfies this condition, a temperature pattern S (P2 = 61.6) as shown in FIG. 8 was found, and a curing experiment based on this temperature pattern S was performed. As a result, when the cured state of the adhesive 15 was confirmed, it was confirmed that a sufficient cured state was obtained.

  That is, it was found that the temperature pattern should be set so that the integrated value P2 is 60 or more as a condition for curing the adhesive 15 of the present embodiment. Thus, since the heat curing conditions can be determined using the temperature pattern, the time required for the heat curing process can be shortened. Furthermore, since it is not necessary to conduct experiments using a large number of test pieces, the cost and time for setting the curing conditions were reduced.

  In this embodiment, as shown in FIG. 9, small protrusions 16 a may be provided above and below the permanent magnet 16. In this way, the adhesive 15 can flow not only in the vertical direction but also in the horizontal direction through the periphery of the protrusion 16a in the inverted preheating process and the erecting preheating process. Accordingly, the adhesive 15 can be spread more smoothly on the entire surface of the permanent magnet 16. In particular, since a sufficient amount of the adhesive 15 can be disposed between the permanent magnet 16 and the thin steel plates 18 and 19, a more reliable bonding state can be obtained.

  Furthermore, the slots 14 are relatively large, and there are cases where two permanent magnets 16 are inserted in combination in each slot 14. In this case, as shown in FIG. 10, small protrusions 16 a may be formed at positions shifted from each other on the upper and lower surfaces of the permanent magnet 16. In particular, as shown in FIGS. 10 (a) and 10 (c), the permanent magnets 16 are preferably arranged at diagonal positions in the upper and lower surfaces. Here, FIG. 10A is a diagram when FIG. 10B is viewed from above, and FIG. 10C is a diagram when FIG. 10B is viewed from below.

  In this way, when two permanent magnets 16 are stacked, they can be stably arranged as shown in FIG. Furthermore, since an appropriate gap can be provided between the two permanent magnets 16, the adhesive 15 can be disposed also in this gap, and the two permanent magnets 16 can be securely bonded to each other. it can. The shape of these protrusions 16a is not limited to the hemispherical shape shown in the figure, and may be any shape such as a prism, a pyramid, a cylinder, or a cone.

  As described in detail above, according to the method for manufacturing the rotor 1 of the present embodiment, since the inverted preheating process and the erecting preheating process are performed after the assembly process of the rotor 1, the surface of the permanent magnet 16 is spread over a wide range. An adhesive 15 can be attached. Furthermore, bubbles generated in the adhesive 15 are collected near the upper surface of the rotor 1 during the erecting preheating process. Even if the bubbles collected near the upper surface expand during the next thermosetting process, there is no risk of pushing the adhesive 15 out.

  Furthermore, since the relationship between the temperature and time required for the thermosetting of the adhesive 15 is approximated by a quadratic expression, it can be easily predicted whether or not the determination threshold value is exceeded by calculating the integrated value P2 of the temperature pattern. it can. Since the curing start temperature is known for each type of adhesive, it is easy to calculate the integrated value P2 of each temperature pattern as long as each coefficient α, β, γ is obtained according to the type of adhesive. is there. Furthermore, it is easy to set a threshold value for determination from the standard curing conditions. Therefore, experiments with a large number of test pieces are not required, and curing conditions can be set at a low cost and in a short time. This also makes it possible to easily find a temperature pattern that shortens the time required for the thermosetting process, and to shorten the time required for the entire manufacturing process of the rotor 1. For these reasons, when the permanent magnet 16 is bonded and fixed to the slot 14 formed in the rotor 1, the adhesive 15 can be firmly bonded without leaking to the outside, and the setting of curing conditions and the manufacturing time of the rotor 1 can be shortened. It is a manufacturing method.

In addition, this form is only a mere illustration and does not limit this invention at all. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof.
For example, although the thin steel plate 18 is sandwiched between the end plate 17 and the rotor core 13 in this embodiment, the thin steel plate 18 is not necessary when the end plate 17 has substantially the same thermal expansion coefficient as that of the electromagnetic steel plate 13a. In the present embodiment, the thin steel plate 19 is sandwiched between the magnet end 12 and the rotor core 13, but the thin steel plate 19 is not necessary when the magnet end 12 has substantially the same thermal expansion coefficient as that of the electromagnetic steel plate 13a.
Further, for example, the temperature pattern in the thermosetting process is not limited to the temperature pattern S illustrated in FIG. 8 as long as the integrated value P2 is equal to or greater than the threshold value.

It is a top view which shows the rotor which concerns on this form. It is sectional drawing which shows the rotor which concerns on this form. It is explanatory drawing which shows an assembly process among the manufacturing methods of a rotor. It is explanatory drawing which shows an inverted preheating process among the manufacturing methods of a rotor. It is explanatory drawing which shows an erecting preheating process among the manufacturing methods of a rotor. It is explanatory drawing which shows the thermosetting process among the manufacturing methods of a rotor. It is a graph which shows the hardening conditions of an adhesive agent. It is a graph which shows the hardening conditions of an adhesive agent. It is explanatory drawing which shows the example of the shape of a permanent magnet. It is explanatory drawing which shows the example of the shape of a permanent magnet. It is explanatory drawing which shows the example of the shape of a permanent magnet.

Explanation of symbols

1 Rotor 13 Rotor Core 14 Slot 15 Adhesive 16 Permanent Magnet 17 End Plate

Claims (5)

An adhesive injection step of injecting an adhesive into a slot formed in the rotor core, a magnet insertion step of inserting a permanent magnet into the slot, an attachment step of fixing the end plate over the rotor core and closing the slot, A method for manufacturing a rotor of a permanent magnet motor, comprising: a thermosetting step of thermosetting the adhesive in the slot by heating the rotor;
Between the mounting step and the thermosetting step,
An inverted preheating step of maintaining the rotor at a preheating temperature higher than normal temperature and lower than the curing start temperature of the adhesive, with the rotor being turned upside down with the adhesive injection step;
A method for manufacturing a rotor of a permanent magnet motor, comprising: an erecting preheating step for returning the upper and lower portions of the rotor to the same state as in the adhesive injection step and maintaining the rotor at a preheating temperature. An adhesive injection step of injecting an adhesive into a slot formed in the rotor core, a magnet insertion step of inserting a permanent magnet into the slot, an attachment step of fixing the end plate over the rotor core and closing the slot, A method for manufacturing a rotor of a permanent magnet motor, comprising: a thermosetting step of thermosetting the adhesive in the slot by heating the rotor;
A preheating step of maintaining the rotor at a preheating temperature higher than normal temperature and lower than the curing start temperature of the adhesive between the attachment step and the thermosetting step;
The first stage of the preheating process is performed with the rotor upside down reversed from the time of the adhesive injection process,
A rotor manufacturing method for a permanent magnet motor, characterized in that the latter stage of the preheating step is performed by returning the top and bottom of the rotor to the same state as in the adhesive injection step. In the rotor manufacturing method of the permanent magnet motor according to claim 1 or 2,
A method of manufacturing a rotor for a permanent magnet motor, wherein the thermosetting step is performed at a temperature higher than the curing start temperature of the adhesive, and the upper and lower sides of the rotor are in the same state as in the adhesive injection step. In the rotor manufacturing method of the permanent magnet motor according to any one of claims 1 to 3, the thermosetting step includes
Over a period when the rotor temperature is equal to or higher than the curing start temperature of the adhesive,
A method of manufacturing a rotor for a permanent magnet motor, characterized in that the temperature value square is multiplied by a first pattern + first coefficient + temperature value * second coefficient + third coefficient. In a curing degree prediction method for predicting the degree of curing of the adhesive in the thermal curing process in which the adhesive in the slot is thermally cured by heating the rotor,
Over a period when the rotor temperature is equal to or higher than the curing start temperature of the adhesive,
The integrated value of the square of temperature value x first coefficient + temperature value x second coefficient + third coefficient is compared with the judgment threshold value,
If the integrated value is equal to or greater than the judgment threshold, it is judged that curing is sufficient.
If the integrated value is less than the determination threshold, it is determined that the curing is insufficient.

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