This application is based upon and claims the benefit of priority from Japanese patent application No. 2021-189255, filed on Nov. 22, 2021, the disclosure of which is incorporated herein in its entirety by reference.
The present disclosure relates to an apparatus and a method for manufacturing a reactor.
Japanese Unexamined Patent Application Publication No. 2013-149841 discloses a method for manufacturing a reactor including a primary molding step and a secondary molding step. According to the technique described in Japanese Unexamined Patent Application Publication No. 2013-149841, a common mold can be used for both primary and secondary molding.
In the secondary molding step, when a resin preferentially enters an outer peripheral side of the core, the core cannot be supported against a resin pressure, and therefore, there is a problem that a high stress is generated in the core, and thus the core is cracked.
The present disclosure has been made in order to solve such a problem, and an object of the present disclosure is to provide an apparatus and a method for manufacturing a reactor capable of preventing a core from being cracked due to a resin pressure during molding.
In an example aspect of the present disclosure, an apparatus for manufacturing a reactor provided with a core includes: a mold including a cavity for housing the core.
The mold includes a core support pin brought into contact with the core and configured to support the core against a resin pressure during molding,
resin flow paths during molding include an inner flow path passing through inside the core and an outer flow path passing through outside the core, and
the core support pin is disposed at a position where a width of the inner flow path is greater than a width of the outer flow path.
In another example aspect of the present disclosure, a method for manufacturing a reactor provided with a core includes:
molding a molded article by using a mold including a cavity for housing the core.
The mold includes a core support pin brought into contact with the core for supporting the core against a resin pressure during molding,
resin flow paths in the molding of the molded article include an inner flow path passing through inside the core and an outer flow path passing through outside the core, and
the core support pin is disposed at a position where a width of the inner flow path is greater than a width of the outer flow path.
According to the present disclosure, it is possible to provide an apparatus and a method for manufacturing a reactor capable of preventing a core from being cracked due to a resin pressure during molding.
The above and other objects, features and advantages of the present disclosure will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present disclosure.
First, the contents of the study conducted by the inventor of the present application will be described.
The mold 200 includes a cavity for housing the core 10. For example, a pair of E-shaped cores 10 are inserted into the cavity. The core 10 may be a sintered product obtained by sintering a compact.
The base core 11 includes a connection part 111a for connecting the middle leg core 12 to the outer leg core 13a, and a connection part 111b for connecting the middle leg core 12 to the outer leg core 13b. Hereinafter, when the connection parts 111a and 111b are not distinguished from each other, they may be simply referred to as the connection parts 111.
Widths of the outer leg cores 13a and 13b (e.g., the length thereof in the X direction) are smaller than a width of the middle leg core 12. In a reactor of a smaller size, the outer leg core 13 may become thinner, and thus the outer leg core 13 may be broken during molding.
Returning to
In order to prevent the core 10 from being cracked, the inventor studied the relationship between the size of each flow path 30 and the cracking modes of the core 10.
A mode 2 occurs also when the outer flow path 32 is filled with a resin first. In the mode 2, the base core 11 is pressurized in the Y direction as indicated by the arrow, and a high stress is generated in a part X2. A possible cause of the mode 2 may be because there is no support mechanism inside the base core 11.
A mode 3 occurs when the core 10 is filled with a resin first from an upper side of the core 10. In the mode 3, the core 10 is pressurized downward as indicated by the arrow, and a high stress is generated in a part X3. A possible cause of the mode 3 may be because there is no support mechanism on a lower side of the core 10 (e.g., on the negative direction side of the Z-axis).
The inventor of the present application arrived at the present disclosure according to the embodiment based on the above study. Hereinafter, the present disclosure will be described through an embodiment of the disclosure, but the disclosure according to the claims is not limited to the following embodiment. Further, not all of the configurations described in the embodiment are essential as means for solving the problem.
A manufacturing apparatus according to a first embodiment will be described below with reference to the drawings.
The mold 100 includes core support pins 110a, 110b, 110c, 110d, 110e, 110f, and 110g. Hereinafter, when the core support pins 110a, 110b, 110c, 110d, 110e, 110f, and 110g are not distinguished from each other, they may be referred to simply as the core support pins 110. Since a resin does not flow into parts of the mold 100 that are in contact with the core support pins 110, windows corresponding to the core support pins 110 are formed in a molded article.
The core support pins 110 are in contact with the core 10 and support the core 10 against the resin pressure during molding. The core support pins 110a, 110b, 110c, and 110d support the outer leg core 13 against the resin pressure indicated by the arrows in the ±X direction during molding. The core support pins 110e, 110f, and 110g support the base core 11 against the resin pressure indicated by the arrows in the ±Y direction during molding. The downward arrow indicates that the resin pressure is received from both of the two inner flow paths 31. The core support pins 110e and 110f support the connection part 111 included in the base core 11.
The core support pins 110a, 110b, 110c, 110d, 110e, and 110f are located at positions where the widths of the inner flow paths 31 are greater than that of the outer flow path 32. Some of the core support pins 110 (e.g., the core support pin 110e) may be disposed at other positions.
In the mold 100, the width W2 of the inner flow path 31a in the X direction is greater than the width W1 of the outer flow path 32 in the X direction. In other words, a width of the above-mentioned gap is greater than the width of the flow path outside the outer leg core 13a. In such a case, the outer leg core 13a of the core 10 is pressurized in the direction indicated by the leftward arrow. The core support pin 110a supports the outer leg core 13a against the pressure in the direction of the leftward arrow to prevent deformation of the outer leg core 13a.
Similarly, the width of the inner flow path 31a in the Y direction is greater than the width of the outer flow path 32 in the Y direction. Accordingly, the base core 11 of the core 10 is pressurized in the direction indicated by the upward arrow. The core support pin 110f supports the base core 11 against the pressure in the direction of the upward arrow to prevent the deformation of the base core 11.
The mold 100 is designed in such a way that the widths of the inner flow paths 31 become greater than the width of the outer flow path 32, so that the core 10 can be prevented from being deformed inward and broken. The core 10 is supported from the outside by the core support pins 110, and thus the mold 100 can prevent the core 10 from being deformed outward and broken. Therefore, the manufacturing apparatus according to the first embodiment can prevent the core 10 from being broken by the resin pressure during molding.
Next, a preferred dimensional relationship of the flow paths 30 will be described with reference to
Referring to
Referring to
Referring to
In the manufacturing apparatus according to the first embodiment, since the size of the inner flow path is larger than that of the outer flow path, a resin is first injected into the inside of the core 10, and the core subjected to the resin pressure is supported by the pins provided in the mold. Therefore, the manufacturing apparatus according to the first embodiment can prevent the core 10 from being broken by reducing the deformation of the core and reducing the stress inside the core.
Note that the present disclosure is not limited to the above-described embodiment, and may be suitably modified without departing from the spirit.
From the disclosure thus described, it will be obvious that the embodiments of the disclosure may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure, and all such modifications as would be obvious to one skilled in the art are intended for inclusion within the scope of the following claims.
Number | Date | Country | Kind |
---|---|---|---|
2021-189255 | Nov 2021 | JP | national |