JP2011116063A - Method of manufacturing resin molding, method of manufacturing apparatus and turntable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent product defect due to protrusion of gate mark in a method of manufacturing a resin molding. <P>SOLUTION: The method of manufacturing a resin molding includes processes of: forming a cavity by mold clamping a first mold having a gate and a second mold; molding the resin molding by injecting resin from the gate into the cavity; exposing the gate mark 635 of the resin molding by separating the first mold from the second mold; inserting a holding tool 84 between the first mold and second mold; crushing the gate mark by making the holding tool abut on the gate mark of the resin molding; holding the resin molding with the holding tool; and taking out the resin molding together with the holding tool from between the first mold and second mold. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a resin molded product by injection molding, and more particularly to a method for manufacturing a turntable provided in a motor for driving a recording disk.

  In the recording disk drive device in which the recording disk can be replaced, a chucking device for chucking the recording disk is provided. The turntable of the chucking device is manufactured using resin injection molding. As a result, the cost of manufacturing the turntable can be reduced and the shape accuracy can be improved. In particular, the deflection accuracy of the disk mounting surface on which the recording disk is mounted, the shape accuracy of the guide surface that guides the recording disk to the disk mounting surface, and the coaxiality of the rotation axis of the recording disk and the rotation axis of the motor are matched. Alignment accuracy is required.

  On the other hand, in resin injection molding, when a resin molded product is released from a mold, a gate mark is formed on the resin molded product. Such a gate mark is usually formed at a site that does not affect the important shape of the resin molded product.

Japanese Patent Application Laid-Open Nos. 2001-37141 and 2003-299302 disclose an insert-molded turntable and a rotor holder of a motor. The integral molding improves the rigidity of the resin turntable. Further, it is possible to omit the step of combining the rotor holder and the turntable by integral molding.
JP 2001-37141 A JP 2003-299302 A

  By the way, when a turntable or a part thereof is molded with resin, a gate mark is provided on the upper side or the lower side of the turntable. If the gate mark protrudes upward, it may interfere with the recording disk or the clamper of the recording disk. If the gate mark protrudes downward, it may interfere with the stationary part of the motor. In particular, in the case of insert molding, since the thickness of the resin is thin, a deep recess cannot be provided around the gate trace. As a result, the gate mark tends to protrude from the surface of the resin.

  In order to prevent product defects due to the protrusion of the gate trace, it is necessary to inspect the protrusion of the gate trace on the total number of turntables. When it protrudes, it is necessary to crush the gate mark.

  The present invention has been made in view of the above problems, and an object thereof is to prevent the protrusion of a gate mark.

  The method of manufacturing a resin molded product according to one aspect of the present invention includes a step of clamping a first mold having a gate and a second mold to form a cavity, and resin from the gate into the cavity. A step of molding a resin molded product, a step of separating the first mold and the second mold and exposing a gate mark of the resin molded product, and the first mold, A step of inserting a holder between the second mold, a step of crushing the gate mark by bringing the holder into contact with the gate mark of the resin molded product, and the holder A step of holding the resin molded product, and a step of taking out the resin molded product together with the holder from between the first mold and the second mold.

  According to the present invention, the protrusion of the gate trace can be prevented. This eliminates the step of inspecting the protrusion of the gate trace and the step of crushing the protruding gate trace.

FIG. 1 is a cross-sectional view of a recording disk drive device. FIG. 2 is a longitudinal sectional view of the motor. FIG. 3 is a plan view of the turntable. FIG. 4 is a plan view of the turntable. FIG. 5 is a cross-sectional view of the turntable. FIG. 6 is a diagram showing a flow of manufacturing the turntable. FIG. A is a figure which shows the mode of manufacture of a turntable. FIG. B is a figure which shows the mode of manufacture of a turntable. FIG. C is a figure which shows the mode of manufacture of a turntable. FIG. D is a figure which shows the mode of manufacture of a turntable. FIG. E is a figure which shows the mode of manufacture of a turntable. FIG. F is a diagram showing a state of manufacturing the turntable. FIG. A is a cross-sectional view of a holder. FIG. B is a front view of a holder. FIG. A is a figure which shows a turntable and a holder. FIG. B is a figure which shows a turntable and a holder. FIG. 10 is a diagram illustrating another example of the holder. FIG. 11 is a cross-sectional view illustrating another example of the turntable and the holding tool. FIG. 12 is a diagram illustrating another example of the turntable. FIG. 13 is a diagram showing still another example of the turntable. FIG. 14 is a diagram showing still another example of the turntable.

  In this specification, the rotating part side in the central axis direction of the motor is simply referred to as “upper side”, and the stationary part side is simply referred to as “lower side”. In the description of the present invention, when the positional relationship and direction of each member are described in the upper, lower, left, and right directions, the positional relationship and direction in the drawing are shown in principle, and the positional relationship and direction when incorporated in an actual device are shown. It is not a thing.

(Structure of recording disk drive)
FIG. 1 is a cross-sectional view taken along a plane including a central axis of a recording disk drive apparatus 10 including a motor according to an embodiment of the present invention. The recording disk drive device 10 includes a motor 1, an access unit 11, and a box-shaped housing 12 that accommodates them. In FIG. 1, the housing 12, a clamper 122 (described later), a clamp magnet 123, and the recording disk 9 are indicated by a two-dot chain line. The motor 1 is held by the chassis 121. The access unit 11 includes a head 111 and a head moving mechanism 112. The head 111 is an optical pickup mechanism that reads and / or writes information on the recording disk 9. For example, a Blu-ray disc is used as the recording disc 9. The head moving mechanism 112 moves the head 111 with respect to the motor 1 and the recording disk 9. The head 111 has a light emitting part and a light receiving part. The light emitting unit emits laser light toward the lower surface of the recording disk 9. The light receiving unit receives reflected light from the recording disk 9.

  The housing 12 is provided with a transport mechanism (not shown). The recording disk 9 is inserted into and removed from the housing 12 by the transport mechanism. A clamper 122 having a clamp magnet 123 is provided in the housing 12.

  When the recording disk 9 is inserted, the disk center hole 91 at the center of the recording disk 9 is disposed above the turntable 13 of the motor 1. Then, the motor 1 is raised and the recording disk 9 is placed on the turntable 13. The clamp magnet 123 attracts the metal plate member of the turntable 13 from above, whereby the recording disk 9 is clamped on the turntable 13 by the clamper 122.

  In the recording disk drive device 10, the recording disk 9 is rotated by the motor 1, and the head moving mechanism 112 moves the head 111 to a required position, and information is read from and / or written to the recording disk 9. When the recording disk 9 is taken out, the clamper 122 is separated from the recording disk 9, the motor 1 is lowered, and the recording disk 9 is removed from the turntable 13.

(Motor structure)
FIG. 2 is a longitudinal sectional view of the motor 1. The motor 1 includes a rotating unit 2 that is a rotating assembly, a stationary unit 3 that is a fixed assembly, a turntable 13, and a bearing mechanism 4. The rotating part 2 is supported by the bearing mechanism 4 so as to be rotatable above the stationary part 3. The turntable 13 is provided at the upper end of the rotating unit 2.

  The rotating unit 2 includes a lid-shaped substantially cylindrical rotor holder 21 and an annular rotor magnet 22. The rotor magnet 22 is attached to the inner surface of the cylindrical portion of the rotor holder 21. A cylindrical shaft fixing portion 23 is provided at the center of the rotor holder 21. The shaft 41 of the bearing mechanism 4 is inserted into the shaft fixing portion 23 and fixed to the rotor holder 21.

  The stationary part 3 includes a substantially plate-like base part 31, a stator 32, and a circuit board 33. The circuit board 33 is disposed on the base portion 31. The base portion 31 is made of metal, and the bearing mechanism 4 is attached to the central hole 311 of the base portion 31. The stator 32 includes a stator core 321 and a plurality of coils 322 formed on the stator core 321. Stator core 321 is formed of a laminated steel plate. The stator 32 is attached to the outer surface of the cylindrical portion 421 of the sleeve holding portion 42. The stator 32 faces the rotor magnet 22 in a direction perpendicular to the central axis J1. When the motor 1 is driven, a magnetic action is generated between the rotor magnet 22 and the stator 32.

  The bearing mechanism 4 includes a shaft 41, a bottomed cylindrical sleeve holding portion 42, a sleeve 43, and an annular retaining member 44. An annular groove 411 is formed at the lower end of the shaft 41. The sleeve 43 is formed of an oil-containing porous metal body. The sleeve holding part 42 has a cylindrical part 421, an annular step part 422, and a bottom part 423. In the stepped portion 422, the diameter decreases from the lower end of the cylindrical portion 421 toward the central axis J1. The bottom part 423 closes the lower end of the sleeve holding part 42 below the step part 422.

  The retaining member 44 is formed of an elastic body such as resin and is placed on the stepped portion 422. The inner end of the retaining member 44 is located in the groove 411 of the shaft 41. Thereby, the shaft 41 is prevented from coming out of the sleeve holding portion 42. A disc-shaped thrust plate 45 is provided inside the bottom portion 423. When the motor 1 is driven, the shaft 41 is stably supported in the thrust direction by the tip of the shaft 41 coming into contact with the thrust plate 45. Further, the shaft 41 is supported by the sleeve 43 in the radial direction via oil.

  The turntable 13 includes an annular plate member 131, an annular central resin portion 132, and an annular rubber 133. In FIG. 2, a part of the shape on the back side of the plate member 131 is indicated by a broken line. The plate member 131 is made of a soft ferromagnetic material and is molded by press working. The thickness of the plate member 131 is about 0.8 mm. The plate member 131 is, for example, an electrogalvanized steel sheet (SECC).

  The plate member 131 includes a plate outer peripheral portion 51 that is an outer peripheral portion of the plate member 131, a plate central portion 52 that is a central portion of the plate member 131, and a bent portion that is located between the plate central portion 52 and the plate outer peripheral portion 51. 53. The plate outer peripheral portion 51 is substantially perpendicular to the central axis J1. The plate central portion 52 is substantially perpendicular to the central axis J1 and is located above the plate outer peripheral portion 51. In the turntable 13, a sufficient magnetic action can be exerted between the clamp magnet 123 of FIG. For this reason, the plate member 131 should just be a soft ferromagnetic material, and an inexpensive material can also be selected. Thereby, the turntable 13 is manufactured at low cost.

  The central resin portion 132 is disposed substantially at the center of the plate member 131 and is formed by resin injection molding. Thereby, the plate member 131 and the center resin part 132 become one component. The central resin portion 132 projects upward from the plate outer peripheral portion 51. Since the central resin portion 132 covers almost the entire plate central portion 52 and the bent portion 53, the plate member 131 is prevented from being separated from the central resin portion 132. The central resin portion 132 is formed of a resin material such as polycarbonate (PC), for example.

  The central resin portion 132 includes a resin cylindrical portion 61, an inclined surface 631, a substantially circular upper surface 632, and a plurality of claws 633. The entire central resin portion 132 including these portions is formed as a continuous member. The resin cylindrical portion 61 has a central resin through-hole 611 that is located inside the plate central hole 55 provided in the approximate center of the plate member 131 and penetrates the plate central hole 55. The upper part of the shaft 41 is fixed to the central resin through hole 611.

  The inclined surface 631 is an outer peripheral portion of the upper portion 63 of the central resin portion 132 and is inclined so as to be separated from the central axis J1 as it goes downward from the outer edge of the upper surface 632. The bent portion 53 of the plate member 131 is bent so as to approximately follow the outer peripheral shape of the inclined surface 631.

  The plurality of claws 633 are provided at a plurality of locations on the inclined surface 631, and are portions away from the central axis J <b> 1 as it goes downward from the inclined surface 631. If the nail | claw 633 has a site | part which leaves | separates from the central axis J1 as it goes below, the nail | claw 633 does not need to incline as a whole. Hereinafter, the radial direction centered on the central axis J1 is simply referred to as “radial direction”, and the circumferential direction centered on the central axis J1 is simply referred to as “circumferential direction”.

  When the recording disk 9 of FIG. 1 is attached to the turntable 13, the disk center hole 91 is guided to the claw 633 by the inclined surface 631, and the claw 633 contacts the disk center hole 91. The recording disk 9 is disposed on the plate member 131. Precisely, the recording disk 9 is placed on the annular rubber 133 on the plate member 131. In other words, the disk mounting portion 134 is formed around the central resin portion 132 by the plate member 131 and the annular rubber 133. The disk mounting portion 134 may be only the plate member 131, and conversely, components other than the annular rubber 133 may be provided.

  In a state where the recording disk 9 is placed on the disk placing portion 134, the claw 633 is elastically deformed radially inward while being supported by the upper portion 63. By utilizing the elastic deformation of the claw 633, the center of the recording disk 9 can be accurately positioned on the central axis J1. For this reason, even a recording disc such as a Blu-ray disc requiring high alignment performance can be attached to the turntable 13 with high accuracy.

  3 and 4 are plan views of the turntable 13. In FIG. 4, the central resin portion 132 is shaded in parallel. FIG. 5 is a cross-sectional view of the turntable 13 at the position of the arrow A in FIG. In FIG. 5, a part of the shape on the back side of the plate member 131 is indicated by a broken line. The same applies to the other figures below. As shown in FIGS. 3 and 5, the upper surface 632 and the inclined surface 631 are provided with seven concave portions 634 that are recessed downward across the portions in the circumferential direction at equal intervals. As will be described later, at the time of injection molding of the central resin portion 132, the resin is injected from a gate provided at a position corresponding to the recess 634 into a cavity in the mold. When the molded product is separated from the mold, the resin is cut at the gate, so that a convex gate mark 635 is formed in the concave portion 634. The recess 634 may be provided only on the upper surface 632 or may be provided only on the inclined surface 631. The gate mark 635 is located closer to the central axis J1 than the plurality of claws 633 in the radial direction. Further, the gate mark 635 is located between the plurality of claws 633 in the circumferential direction.

  As shown in FIG. 5, an annular resin recess 641 that is recessed upward around the central resin through-hole 611 is provided in the lower portion 64 below the plate member 131 of the central resin portion 132. At the time of injection molding of the central resin portion 132, a plurality of types of pins are arranged in the cavity, and the annular resin recess 641 is formed with a plurality of recesses 671 and 672 that indicate pin marks.

  The plate member 131 is provided with an opening 54 below the claws, and a resin layer 65 is provided on the edge 541 of the opening 54 as a part of the central resin portion 132. Thereby, interference with a metal mold | die and the plate member 131 is prevented. A claw position through hole 66 that overlaps the claw 633 and the direction parallel to the central axis J1 is formed inside the resin layer 65. The tip of the claw 633 is located in the claw position through hole 66. One claw position through hole 66 corresponds to one claw 633.

(Manufacture of turntables)
Next, the flow of manufacturing the turntable 13 and the main configuration of the manufacturing apparatus will be described with reference to FIGS. A thru | or FIG. A description will be given with reference to FIG. FIG. A thru | or FIG. In F, a cross section is shown without parallel oblique lines.

  First, the plate member 131, which is a plate-shaped and disk-shaped metal member, is sucked and held by the transport mechanism and taken out from a predetermined accommodating portion. FIG. As shown in A, with the central axis J1 of the plate member 131 oriented in the horizontal direction, the plate member 131 is attached to the movable mold 82 using a magnetic action, air suction force, or the like ( Step S11). Actually, a support pin for supporting the plate member 131 is provided in the movable mold 82. The recess 671 in FIG. 5 corresponds to the support pin.

  The movable mold 82 can be advanced and retracted with respect to the fixed mold 81 by an advance / retreat mechanism 86. The movable mold 82 and the plate member 131 approach the fixed mold 81 along the central axis J1. FIG. As shown in B, the fixed mold 81 and the movable mold 82 are clamped while the plate member 131 is sandwiched between the fixed mold 81 and the movable mold 82. A cavity 89 is formed between the fixed mold 81 and the movable mold 82 (step S12).

  The fixed mold 81 includes a flow path 812 that sends resin into the cavity 89 and a gate 811 of the flow path 812. The position of the gate 811 corresponds to the position of the gate mark 635 shown in FIG. Resin heated to about 300 ° C. is injected from the gate 811 into the cavity 89 at a high pressure (step S13). The resin is from the upper surface side to the lower surface side of the plate member 131, that is, FIG. It spreads from the right side to the left side in B, and the entire cavity 89 is completely filled. The temperature of the mold is controlled to 80 to 90 ° C.

  When the resin is solidified and the central resin portion 132 is molded at the center on the plate member 131, FIG. As shown in C, the movable mold 82 is separated from the fixed mold 81 (step S14). At this time, the turntable 13 is separated from the fixed mold 81 together with the movable mold 82. And FIG. As shown in D, the turntable 13 is separated from the movable mold 82 by the eleven release pins 821 lightly pressing 11 portions of the turntable 13 (step S15). Note that FIG. Although only one is shown in D, in practice, a plurality of release pins 821 are provided in the circumferential direction about the central axis J1.

  FIG. As shown in E, the holder 84 attached to the arm 831 of the transport mechanism 83 is inserted between the fixed mold 81 and the movable mold 82. FIG. As shown in F, the holder 84 moves toward the turntable 13 and is pressed against the turntable 13 (step S16). At the same time, the holder 84 sucks and holds the turntable 13 (step S17).

  FIG. A is a cross-sectional view of the holder 84. FIG. FIG. B is a front view of the holder 84, FIG. A view from the left side of A is shown.

  The holder 84 includes an outer member 841 and an inner member 842. The outer member 841 has a substantially cylindrical shape with a bottom centered on the central axis J2. The inner member 842 is substantially cylindrical and is disposed in the outer member 841. The outer member 841 and the inner member 842 are made of resin. A through hole 851 is provided in the upper part of the outer member 841. A tube (not shown) is connected to the through hole 851. An annular gap 852 is provided between the inner member 842 and the outer member 841. By exhausting from the tube, intake is performed from the gap 852. As a result, the holder 84 sucks and holds the plate member 131 of the turntable 13.

  In the center of the inner member 842, a recess 853 for receiving the central resin portion 132 of the turntable 13 is provided. In the recess 853, protrusions 854 are provided at a plurality of circumferential positions around the central axis J2.

  FIG. A is a figure which shows the state which the turntable 13 and the holder 84 oppose, FIG. Corresponds to E. When the mold is separated and the gate mark 635 is exposed, FIG. As shown to A, the some protrusion 854 of the holder 84 opposes the some gate mark 635 of the center resin part 132, respectively. Although the gate mark 635 does not necessarily protrude higher than the upper surface 632 of the central resin portion 132, FIG. In A, the case where it protrudes from the upper surface 632 is drawn.

  FIG. FIG. 7B is a diagram illustrating a state in which the holder 84 has moved toward the turntable 13, and FIG. Corresponds to F. When the holder 84 moves, the gate mark 635 is crushed by the protrusion 854 coming into contact with the gate mark 635. This prevents the gate mark 635 from protruding higher than the upper surface 632 of the central resin portion 132. At the same time, the turntable 13 is sucked and held by suction from the gap 852.

  The suction may be started before the gate mark 635 is crushed, or may be started after the gate mark 635 is crushed and the gap 852 of the holder 84 and the turntable 13 come into contact with each other. As described above, if the crushing of the gate mark 635 and the holding of the turntable 13 are performed substantially simultaneously, the term “simultaneously” does not need to be strictly interpreted.

  The turntable 13 may not be released by the release pin 821, but the holder 84 may directly hold the turntable 13 on the movable mold 82 by suction. On the contrary, the holding tool 84 does not move toward the turntable 13, but the turntable 13 is pushed and held toward the holding tool 84 by protruding the release table 821. Also good.

  When the turntable 13 is held by the holder 84, the transport mechanism 83 moves the holder 84, so that the turntable 13 together with the holder 84 is taken out from between the fixed mold 81 and the movable mold 82 (step). S18), stored in a predetermined container.

  Actually, the arm 831 is provided with another holder that holds the plate member 131 together with the holder 84. When the turntable 13 is received by the holder 84, another holder attaches the plate member 131 to the movable mold 82. Then, when the turntable 13 is accommodated in a predetermined container, another holder holds the next plate member 131. Thereby, a plurality of turntables 13 are sequentially manufactured efficiently. The annular rubber 133 is affixed to the plate member 131 in a later step.

  As described above, in manufacturing the turntable 13, the gate mark 635 is crushed by the holder 84 when the holder 84 takes out the turntable 13 from the mold. Thereby, the protrusion of the gate mark 635 from the upper surface 632 is prevented, and interference between the gate mark 635 and other components such as a clamper is prevented. As a result, the step of inspecting the protrusion of the gate mark 635 and the secondary processing for crushing the protruding gate mark 635 are not required. The manufacturing cost of the turntable 13 is reduced. Appearance defects are also prevented.

  Since the turntable 13 is held by the holder 84 simultaneously with the crushing of the gate mark 635, the operation of the mold of the manufacturing apparatus and the transport mechanism 83 is simplified. Furthermore, the turntable 13 is easily held by the holder 84 by suction.

  Since the crushing of the gate mark 635 is performed by the protrusion 854, interference between the portion around the gate mark 635 and the holder 84 can be easily avoided.

  The protrusion of the gate mark 635 is likely to occur when a deep recess cannot be formed around the gate mark 635. In particular, when insert molding or outsert molding is performed on a metal member, the thickness of the resin becomes thin, and it becomes difficult to provide a deep recess around the gate trace. Therefore, the crushing of the gate mark is particularly suitable for manufacturing such a resin molded product.

  On the other hand, in the injection molding of the central resin portion 132, since the gate 811 is positioned above the plate member 131, the space for forming the claws can be filled with the resin at an early stage. Therefore, the claw 633 can be manufactured with high accuracy without causing sink marks. Further, the gate mark 635 is disposed on the central axis J1 side with respect to the plurality of claws 633 in the radial direction. Thereby, the resin can be easily filled in the portion corresponding to the claw 633 of the cavity 89. In particular, since the gate is disposed so that the gate mark 635 is positioned between the plurality of claws 633 in the circumferential direction, the resin is more easily filled. It is also possible to prevent the weld line from being positioned on the inclined surface 631.

  If the resin can be filled up to the nail 633, the gate mark may be provided on the lower surface of the central resin portion 132. The same applies to FIGS. 12 and 13 described later.

  The above-described operation and effects relating to the manufacture of the turntable 13 are the same in the following other examples.

(Other examples of holders)
FIG. 10 is a diagram illustrating another example of the holder 84. The holder 84 includes a mechanical chuck 843 and a chuck driving unit 844 in place of the outer member 841. Three or more mechanical chucks 843 are arranged at equal intervals around the central axis J2. The mechanical chuck 843 is advanced and retracted with respect to the central axis J2 by the chuck driving unit 844.

  When the turntable 13 is held by the holder 84, the holder 84 approaches relatively to the turntable 13. The protrusion 854 of the inner member 842 contacts the gate mark 635 and the gate mark 635 is crushed. When the inner member 842 comes into contact with the turntable 13, the mechanical chuck 843 moves toward the central axis J2. Thereby, the outer edge part of the turntable 13 is hold | maintained.

(Other examples of turntables and holders)
FIG. 11 is a cross-sectional view showing another example of the turntable 13 and the holder 84. The turntable 13 does not have the plate member 131. The disk mounting part 134 is formed of resin. The central resin part 132 does not have the claw 633. The gate mark 635 is formed on the upper surface of the disk mounting unit 134.

  The holder 84 is shown in FIG. Similar to A, an outer member 841 and an inner member 842 are provided. Suction is performed from the gap 852 between the outer member 841 and the inner member 842. Thereby, the disk mounting part 134 is sucked and the turntable 13 is held. The inner member 842 has a protrusion 854 at a position corresponding to the gate mark 635. FIG. Similar to B, the turntable 13 is held by the holder 84 simultaneously with the crushing of the gate mark 635 by the protrusion 854.

  The turntable 13 may be molded so that the gate mark 635 is formed on the lower surface of the disk mounting portion 134.

(Another example of turntable 1)
FIG. 12 is a diagram illustrating another example of the turntable 13. In FIG. 12, the disk part 211 which is a cover part of the rotor holder 21 of the motor 1 plays the role of the plate member 131 of FIG. The rotor holder 21 is a metal member obtained by press-molding a plate-like member into a substantially cylindrical shape with a lid. The shape and other structures of the central resin portion 132 are the same as those in FIG. The manufacturing method of the turntable 13 is the same as that of FIG. 6 except that the rotor holder 21 is attached to the mold instead of the plate member 131 and the central resin portion 132 is molded at the center of the disk portion 211.

(Other example 2 of turntable)
FIG. 13 is a view showing still another example of the turntable 13. The turntable 13 in FIG. 13 is different from the turntable 13 in FIG. The resin may not be molded on the cylindrical portion 212. In other words, the resin is molded at a portion including the disk portion 211 perpendicular to the central axis of the rotor holder 21. Hereinafter, the resin on the disk portion 211 is referred to as “disk-shaped resin portion 130”.

  The disk mounting part 134 is configured by an outer peripheral part on the upper surface of the disk-shaped resin part 130 and an annular rubber 133. The disk mounting part 134 may be only a part of the disk-shaped resin part 130, and conversely, parts other than the annular rubber 133 may be provided. The shape and other structures of the central resin portion 132 are the same as those in FIG. The manufacturing method of the turntable 13 is the same as that of FIG. 6 except that the rotor holder 21 is attached to the mold and the shape of the formed cavity is different.

  The gate mark may be provided not only on the upper surface or the lower surface of the central resin portion 132 but also on the upper surface of the disk mounting portion 134. When the gate trace is provided on the lower surface of the central resin portion 132, the gate trace can be crushed to prevent interference between the gate trace and the stator 32 of the motor 1. The same applies to FIG. 12 and FIG. 14 described later.

(Turntable other example 3)
FIG. 14 is a view showing still another example of the turntable 13. In the turntable 13 of FIG. 14, the resin is formed up to the outer peripheral portion of the disk portion 211 of the rotor holder 21 and the cylindrical portion 212 as in the turntable 13 of FIG. 13. Hereinafter, the resin on the disk portion 211 is referred to as “disk-shaped resin portion 130”. Similar to FIG. 13, the outer peripheral portion of the upper surface of the disk-shaped resin portion 130 becomes the disk mounting portion 134 or a part thereof. A balance steel ball 135 is accommodated in the disk mounting portion 134.

  Unlike FIG. 13, the central resin portion 132 is a separate member from the disk-shaped resin portion 130. The central resin portion 132 is biased upward by a spring 136 that is an elastic member. The central resin portion 132 is not provided with claws but is provided with a first inclined surface 71 and a second inclined surface 72. The first inclined surface 71 is a conical surface with a gentle inclination. The second inclined surface 72 extends downward from the outer edge of the first inclined surface 71. The second inclined surface 72 is a conical surface having a larger inclination than the first inclined surface 71. The first inclined surface 71 and the second inclined surface 72 constitute a disk guide portion that guides the center hole of the recording disk 9.

  A yoke 137 and a clamp magnet 138 are disposed inside the central resin portion 132. The yoke 137 is fixed to the shaft 41. The clamp magnet 138 is fixed to the yoke 137. When the clamper descends from above in the disk drive device, the clamp magnet 138 and the clamper attract each other, whereby the recording disk 9 is fixed on the disk mounting portion 134. At this time, the central resin portion 132 is slightly lowered while aligning the recording disk 9.

  In the case of FIG. 14, in the resin product injection molding shown in FIG. 6, the resin portion on the rotor holder 21 excluding the central resin portion 132 is molded. Hereinafter, this resin portion is referred to as a rotor resin portion 73. When the integrated body of the rotor holder 21 and the rotor resin portion 73 is manufactured, the turn table 13 is manufactured by assembling the spring 136, the central resin portion 132, the yoke 137, the clamp magnet 138, and the like.

  The rotor resin portion 73 is preferably provided with a gate mark on the upper surface. However, as illustrated in FIG. 14, when the resin 731 is also provided on the lower side through the opening provided in the disk portion 211 of the rotor holder 21, a gate mark is provided on the lower surface of the rotor resin portion 73. Good.

(Modification)
As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible.

  For example, the gate 811 may be provided in the movable mold 82. The gate 811 may be provided on both the fixed mold 81 and the movable mold 82. The gate mark can be provided at various positions on the upper side or the lower side of the turntable 13. The plate member 131 and the rotor holder 21 may be attached to the fixed mold 81.

  The contact portion that crushes the gate mark may be a flat portion instead of the protrusion 854. The crushing of the gate mark and the holding of the turntable 13 by the holder 84 may be performed separately.

  The crushing of the gate mark by the holder can be used for manufacturing various resin molded products other than the turntable 13.

  The present invention can be used for manufacturing various resin products by injection molding.

DESCRIPTION OF SYMBOLS 1 Motor 9 Recording disk 10 Recording disk drive device 11 Access part 12 Housing 13 Turntable 21 Rotor holder 81 Fixed mold 82 Movable mold 83 Conveyance mechanism 84 Holder 86 Advance / retreat mechanism 89 Cavity 91 Disk center hole 130 Disc-shaped resin part 131 Plate Member 132 Central resin part 134 Disk placing part 211 Disk part 631 Inclined surface 632 Upper surface 633 Claw 634 Recessed part 635 Gate mark 811 Gate 854 Projection J1 Central axis S11 to S18 Steps

Claims (13)

Forming a cavity by clamping a first mold having a gate and a second mold;
Injecting resin from the gate into the cavity to mold a resin molded product,
Separating the first mold and the second mold, and exposing a gate mark of the resin molded product;
Inserting a holder between the first mold and the second mold;
Crushing the gate mark by bringing the holder into contact with the gate mark of the resin molded product; and
Holding the resin molded product with the holder;
A step of taking out the resin molded product together with the holder from between the first mold and the second mold;
A method for producing a resin molded product.   The method for producing a resin molded product according to claim 1, wherein the step of crushing the gate trace and the step of holding the resin molded product are performed simultaneously.   The method for producing a resin molded product according to claim 2, wherein in the step of crushing the gate mark, the holding tool adsorbs and holds the resin molded product.   The manufacturing method of the resin molded product in any one of Claim 1 thru | or 3 with which the said holder is provided with the processus | protrusion which crushes the said gate trace. A method for producing a resin molded product according to any one of claims 1 to 4,
The resin molded product is a turntable provided in a motor for driving a recording disk,
A method for manufacturing a turntable, wherein the gate mark is provided on an upper side or a lower side of the turntable. A step of attaching a metal member obtained by press-molding a plate-like or plate-like member to the first die or the second die before the step of forming the cavity;
The method for manufacturing a turntable according to claim 5, wherein a resin is molded on the metal member in the step of molding the resin molded product. The metal member is substantially disc-shaped or substantially cylindrical with a lid,
In the step of molding the resin molded product, a central resin portion is molded at the center of the metal member,
The periphery of the central resin part of the metal member is a disk mounting part on which a recording disk is mounted or a part thereof,
The turntable according to claim 6, wherein the central resin portion includes a substantially circular upper surface and an inclined surface that guides the central hole of the recording disk away from the central axis as it goes downward from the outer edge of the upper surface. Production method. The metal member is substantially disc-shaped or substantially cylindrical with a lid,
In the step of molding the resin molded product, a disk-shaped resin portion is molded in a portion including a disk portion approximately perpendicular to the central axis of the metal member,
The method for manufacturing a turntable according to claim 6, wherein the outer peripheral portion of the upper surface of the disk-shaped resin portion is a disk mounting portion on which a recording disk is mounted or a part thereof.   The central resin portion of the disk-shaped resin portion includes a substantially circular upper surface, and an inclined surface that is separated from the central axis and guides the central hole of the recording disk as it goes downward from the outer edge of the upper surface. The manufacturing method of the turntable of description. The central resin portion further includes a plurality of claws having a portion away from the central axis as it goes downward in the outer peripheral portion,
The turntable according to claim 7 or 9, wherein the gate mark is formed in a recess provided on the upper surface or the inclined surface, and is located on the central axis side with respect to the plurality of claws in a radial direction. Manufacturing method.   The method for manufacturing a turntable according to claim 10, wherein the gate mark is located between the plurality of claws in a circumferential direction. A motor comprising a turntable manufactured by the manufacturing method according to any one of claims 5 to 11,
An access unit for reading and / or writing information to and from a recording disk placed on the turntable;
A housing for housing the motor and the access unit;
A recording disk drive device comprising: A first mold having a gate for injecting resin;
A second mold,
An advancing and retracting mechanism for advancing and retracting the second mold with respect to the first mold;
A holder for holding a resin molded product molded in a cavity between the first mold and the second mold after separation of the first mold and the second mold;
A transport mechanism for taking out the resin molded product from between the first mold and the second mold by moving the holder;
With
A resin molded product comprising a contact portion that crushes the gate mark by contacting the gate mark of the resin molded product exposed after separation of the first mold and the second mold. Manufacturing equipment.

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