KR20110063361A - Method and apparatus for production of a resin molded article, and manufacturing method of a turntable - Google Patents

Abstract

PURPOSE: A manufacturing method and device of resin molding products and manufacturing method of turn-table are provided to prevent the interruption between components and gate makes by preventing the protruding of the gate makes from the upper surface. CONSTITUTION: A manufacturing method is as follows. First and second molds are clamped to forms a cavity. Resin is injected to the cavity from a gate of the first mold in order to resin molding products. The first and second molds separate to make a gate mark(635) of the resin molding expose out. A holder(84) is inserted between the first and second molds. The holder is touched with the gate trace of the resin molding products. The gate mark is collapsed. The resin molding product is supported with the holder. The resin molding is ejected between the first and second molds.

Description

METHOD AND APPARATUS FOR PRODUCTION OF A RESIN MOLDED ARTICLE, AND MANUFACTURING METHOD OF A TURNTABLE}

The present invention relates to a method for producing a resin molded article by injection molding. Especially, this invention relates to the manufacturing method of the turntable provided in the motor for recording disk drive especially.

In a recording disk drive device in which recording disks can be replaced, a chucking device for chucking a recording disk is provided. The turntable of the chucking device is manufactured using injection molding of resin. This is intended to reduce the cost of manufacturing the turntable and to improve the shape precision. In the manufacture of turntables, in particular, the precision of vibration of the disk mounting surface on which the recording disk is mounted, the shape precision of the guide surface for guiding 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 Etc. are requested.

On the other hand, in injection molding using resin, when releasing a resin molded article from a metal mold | die, a gate trace is formed in a resin molded article. Such a gate trace is normally formed in the site | part which does not affect the shape of an important part in a resin molding.

For example, Japanese Unexamined Patent Application Publication Nos. 2001-37141 and 2003-299302 disclose that insert-molded rotor holders of a turntable and a motor are disclosed. Integral molding improves the rigidity of the turntable made of resin. In addition, by integral molding, it is possible to omit the step of combining the rotor holder and the turntable.

By the way, when the turntable or a part thereof is molded of resin, the gate traces are provided above or below the turntable. If the gate trace protrudes upward, it may interfere with the recording disk or the clamper of the recording disk. If the gate trace protrudes downward, there is a possibility that it will interfere with the stop of the motor. In the case of insert molding, in particular, since the thickness of the resin is thin, deep recesses cannot be provided around the gate traces. As a result, the gate traces easily protrude from the surface of the resin, and the gate traces interfere with the clamper and the stop.

In order to prevent product defects caused by protrusion of the gate traces, it is necessary to inspect the protrusion of the gate traces for the total number of turntables. When the gate trace protrudes from the surface of the resin, the work of crushing the gate trace is necessary.

This invention is made | formed in view of the said subject, and an object of this invention is to prevent protrusion of a gate trace.

The manufacturing method of the resin molded article which concerns on one side of this invention is a process of forming a cavity by shape | molding the 1st metal mold | die which has a gate, a 2nd metal mold | die, and injecting resin into the said cavity from the said gate, Molding a resin molded article, separating the first mold and the second mold, exposing a gate trace of the resin molded article, and inserting a holding tool between the first mold and the second mold. A step of crushing the gate trace by contacting the holding tool with the gate trace of the resin molded article, holding the resin molded article at the holding tool, and the holding tool And a step of taking out the resin molded article between the first mold and the second mold.

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

1 is a sectional view of a recording disk drive device;
2 is a longitudinal sectional view of a motor;
3 is a plan view of the turntable,
4 is a plan view of a turntable,
5 is a cross-sectional view of the turntable,
6 shows a flow of manufacture of a turntable;
7A is a view showing a state of manufacture of a turntable;
7b shows a state of manufacture of the turntable;
7C is a view showing a state of manufacture of a turntable;
7d shows a state of manufacture of the turntable;
7E is a view showing a state of manufacture of the turntable;
7F is a view showing a state of manufacture of a turntable;
8A is a sectional view of a holding tool;
8B is a front view of the holding tool;
9A is a view showing a turntable and a holding tool;
9B is a view showing a turntable and a holding tool;
10 is a view showing another example of the holding tool;
11 is a sectional view showing another example of the turntable and the holding tool;
12 is a view showing another example of a turntable;
13 is a view showing still another example of a turntable;
14 shows another example of a turntable.

In this specification, in the direction of the center axis of the motor, the rotating part side is simply referred to as "upper side", and the stopper side is simply referred to as "lower side". In addition, in description of this invention, when demonstrating the positional relationship or direction of each member from top to bottom, right and left, as a general rule, the positional relationship and direction are shown in drawing, and the positional relationship and direction when assembled to an actual apparatus are shown. It is not.

(Structure of Recording Disc Drive Unit)

1 is a cross-sectional view taken along a plane including a central axis of a recording disk drive device 10 including a motor according to an embodiment of the present invention. The recording disk drive apparatus 10 includes a motor 1, an access section 11, and a box-shaped housing 12 that accommodates them therein. In FIG. 1, the housing 12, the clamper 122 mentioned later, the clamp magnet 123, and the recording disk 9 are shown by the dashed-dotted 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 for reading and / or writing information about the recording disk 9. As the recording disc 9, for example, a removable disc (Blu-ray Disc, etc.) is used. 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 portion and a light receiving portion. The light emitting portion emits laser light toward the lower surface of the recording disk 9. The light receiving portion receives the reflected light from the recording disk 9.

The housing 12 is provided with a conveyance mechanism (not shown). By the conveyance mechanism, insertion of the recording disk 9 into the housing 12 and extraction from the housing 12 are performed. In the housing 12, a clamper 122 having a clamp magnet 123 is provided.

When the recording disk 9 is inserted, the disk center hole 91 in the center of the recording disk 9 is disposed above the turntable 13 of the motor 1. Then, the motor 1 rises, and the recording disc 9 is mounted on the turntable 13. As the clamp magnet 123 sucks the metal plate member of the turntable 13 from above, 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. At the same time, the head moving mechanism 112 moves the head 111 to the required position, and " read " and / or " write " of information on the recording disk 9 is performed. When the recording disc 9 is taken out, the clamper 122 is separated from the recording disc 9. Then, the motor 1 is lowered, and the recording disk 9 is disengaged from the turntable 13.

(Structure of the motor)

2 is a longitudinal cross-sectional view of the motor 1. The motor 1 is provided with the rotating part 2 which is a rotating assembly, the stop part 3 which is a fixed assembly, the turntable 13, and the bearing mechanism 4. As shown in FIG. The rotating part 2 is supported by the bearing mechanism 4 so that rotation is possible with respect to the stop part 3 above. The turntable 13 is provided at the upper end of the rotating part 2.

The rotating part 2 has a substantially cylindrical rotor holder 21 with a cover and an annular rotor magnet 22. The rotor magnet 22 is mounted on the inner side of the cylindrical portion of the rotor holder 21. The cylindrical shaft fixing part 23 is provided in the center of the rotor holder 21. The shaft 41 of the bearing mechanism 4 is inserted into the shaft fixing part 23 and fixed to the rotor holder 21.

The stop part 3 includes a substantially plate-shaped 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. The bearing mechanism 4 is attached to the center hole 311 of the base part 31. The stator 32 includes a stator core 321 and a plurality of coils 322 formed on the stator core 321. The stator core 321 is formed of a laminated steel sheet. The stator 32 is mounted on the outer surface of the cylindrical portion 421 of the sleeve holding portion 42. The stator 32 opposes the direction perpendicular to the central axis J1 with respect to the rotor magnet 22. In the drive of the motor 1, a magnetic action occurs between the rotor magnet 22 and the stator 32.

The bearing mechanism 4 is provided with the shaft 41, the bottomed cylindrical sleeve holding part 42, the sleeve 43, and the annular fall prevention member 44. As shown in FIG. At the distal end of the shaft 41, an annular groove 411 is formed. The sleeve 43 is formed of an oil-containing porous metal body. The sleeve holding portion 42 has a cylindrical portion 421, an annular stepped portion 422, and a bottom portion 423. In the stepped portion 422, the diameter becomes smaller 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 fall prevention member 44 is formed of elastic bodies, such as resin. The resin member 44 is mounted on the stepped portion 422. The inner end of the release preventing member 44 is located in the groove 411 of the shaft 41. This prevents the shaft 41 from coming out of the sleeve holding portion 42.

A disk-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 contacting the thrust plate 45. In addition, the shaft 41 is supported in the radial direction by the sleeve 43 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 of the inner side of the plate member 131 is shown by the broken line. The plate member 131 is made of a soft ferromagnetic material. The plate member 131 is molded by press working. The thickness of the plate member 131 is about 0.8 mm. The plate member 131 is an electrogalvanized steel sheet SECC, for example.

The plate member 131 is formed between the plate outer circumference 51, which is the outer circumference of the plate member 131, the plate center circumference 52, which is the center of the plate member 131, and the plate central circumference 52 and the plate outer circumference 51. A bent portion 53 is provided. The plate outer peripheral portion 51 is substantially perpendicular to the central axis J1. The plate center portion 52 is substantially perpendicular to the central axis J1 and is located above the plate outer peripheral portion 51. In the turntable 13, sufficient magnetic action can be caused between the clamp magnet 123 of FIG. 1 and the plate outer peripheral portion 51. For this reason, the plate member 131 should just be a soft ferromagnetic material, and an inexpensive material can also be selected. As a result, the turntable 13 is manufactured at low cost.

The central resin portion 132 is disposed at approximately the center of the plate member 131 and is formed by injection molding of resin. Thereby, the plate member 131 and the center resin part 132 become one component. The central resin portion 132 protrudes upward from the plate outer peripheral portion 51. Since the center resin portion 132 covers almost the entirety of the plate center portion 52 and the bent portion 53, the plate member 131 is prevented from being separated from the center 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, an approximately circular upper surface 632, and a plurality of claws 633. The whole central resin part 132 including these sites is formed as a single member. The resin cylindrical part 61 is located inside the plate center hole 55 provided in the substantially center of the plate member 131, and has the center resin through-hole 611 which penetrates the plate center hole 55. As shown in FIG. The upper portion of the shaft 41 is fixed to the central resin through hole 611.

The inclined surface 631 is an outer circumferential portion of the upper portion 63 of the central resin portion 132 and inclines so as to deviate from the central axis J1 as it goes downward from the outer edge of the upper surface 632. The bent part 53 of the plate member 131 is bent so that it may conform substantially to 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 serve as a portion separated from the central axis J1 in a downward direction from the inclined surface 631. The claw 633 does not need to be inclined as long as the claw 633 has a portion separated from the central axis J1 as it goes downward.

Hereinafter, the radial direction centering on the central axis J1 is simply called "diameter direction", and the circumferential direction centering on the center axis J1 is simply called "circumferential direction".

When the recording disc 9 of FIG. 1 is mounted on the turntable 13, the disc center hole 91 is guided to the claw 633 by the inclined surface 631, and the claw 633 is guided by the disc center hole 91. ) Then, the recording disk 9 is disposed on the plate member 131. Accurately, the recording disk 9 is mounted 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 part 134 may be only the plate member 131, and components other than the annular rubber 133 may be provided on the contrary.

In the state where the recording disc 9 is mounted on the disc mounting portion 134, the claw 633 is elastically deformed in the radial direction while being supported by the upper portion 63. By using the elastic deformation of the claw 633, the center of the recording disc 9 can be accurately positioned on the central axis J1. For this reason, even a recording disc such as a Blu-ray disc, which requires high careful performance, can be mounted on the turntable 13 with high accuracy.

3 and 4 are plan views of the turntable 13. In FIG. 4, the parallel oblique line is displayed on the center resin part 132. FIG. 5 is a cross-sectional view of the turntable 13 at the position of arrow A in FIG. 3. In FIG. 5, a part of the shape of the inner side of the plate member 131 is shown by the broken line. The same applies to the other drawings below.

As shown in FIG. 3 and FIG. 5, seven concave portions 634 concave downwards beyond these portions are provided on the upper surface 632 and the inclined surface 631 at equal intervals in the circumferential direction. As described later, during the injection molding of the central resin portion 132, the resin is injected into the cavity in the mold from the gate provided at the position corresponding to the recessed portion 634. When the molded article is separated from the mold, the resin is cut at the gate. Therefore, the convex gate trace 635 is formed in the recessed part 634. The recessed part 634 may be provided only in the upper surface 632, and may be provided only in the inclined surface 631. The gate trace 635 is located closer to the central axis J1 than the plurality of claws 633 in the radial direction. The gate trace 635 is located between the plurality of claws 633 in the circumferential direction.

As shown in FIG. 5, in the lower portion 64 below the plate member 131 of the central resin portion 132, the annular resin recess 641 concave upward from the periphery of the central resin through hole 611. Is prepared. In the injection molding of the central resin part 132, a plurality of types of pins are arranged in the cavity. In the annular resin concave portion 641, a plurality of concave portions 671 and 672 showing traces of these pins are formed.

The opening 54 is provided in the plate member 131 below the claw. As part of the central resin portion 132, a resin layer 65 is provided on the edge 541 of the opening 54. As a result, interference between the mold and the plate member 131 is prevented. Inside the resin layer 65, a claw position through hole 66 is formed which overlaps the claw 633 in a direction parallel to the central axis J1. The tip of the claw 633 is located in the claw position through hole 66. For one claw 633, one claw position through hole 66 corresponds.

(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. 6 and 7A to 7F. 7A to 7F show cross sections without displaying parallel oblique lines.

First, the conveyance mechanism suction-holds the plate member 131 which is a plate-shaped and disk-shaped metal member, and takes out it from a predetermined accommodating part. As shown in FIG. 7A, in a state where the central axis J1 of the plate member 131 is in the horizontal direction, the plate member 131 uses a movable die (using magnetic action or air suction force). 82) (step S11). In practice, a support pin for supporting the plate member 131 is provided in the movable die 82. The recessed portion 671 of FIG. 5 corresponds to the support pin.

The movable die 82 can move forward and backward with respect to the stationary die 81 by the advance mechanism 86. The movable die 82 and the plate member 131 are close to the stationary die 81 along the central axis J1. As shown in FIG. 7B, the stationary die 81 and the movable die 82 are shaped while sandwiching the plate member 131. A cavity 89 is formed between the stationary die 81 and the movable die 82 (step S12).

The stationary die 81 includes a flow path 812 for sending 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 trace 635 shown in FIG. In the cavity 89 from the gate 811, a resin heated to about 300 ° C. is injected at a high pressure (step S13). The resin is widened from the upper surface side of the plate member 131 to the lower surface side, that is, from right to left in FIG. 7B, and is completely filled in the entire cavity 89. The temperature of the metal mold | die is controlled at 80-90 degreeC.

When resin solidifies and the center resin part 132 is shape | molded in the center on the plate member 131, as shown in FIG. 7C, the movable metal mold 82 is isolate | separated from the fixed metal mold 81 (step S14). At this time, the turntable 13 is separated from the stationary mold 81 together with the movable mold 82. In addition, as shown in FIG. 7D, the eleven release pins 821 lightly press 11 places of the turntable 13, so that the turntable 13 is separated from the movable mold 82 (step S15). . In addition, although only one is shown in FIG. 7D, the some release pin 821 is provided in the circumferential direction centering on the center axis J1 actually.

As shown in FIG. 7E, the holding tool 84 attached to the arm 831 of the conveying mechanism 83 is inserted between the fixed mold 81 and the movable mold 82. As shown in FIG. 7F, the holding tool 84 can move toward the turntable 13 and pressurize the turntable 13 (step S16). At the same time, the holding tool 84 sucks and holds the turntable 13 (step S17).

8A is a sectional view of the holding tool 84. FIG. 8B is a front view of the holding tool 84, showing a shape seen from the left side of FIG. 8A.

The holding tool 84 includes an outer member 841 and an inner member 842. The outer member 841 is a substantially cylindrical shape with a bottom about the center axis J2. The inner member 842 is substantially cylindrical in shape and disposed in the outer member 841. The outer member 841 and the inner member 842 are formed of resin. The 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 air from the tube, intake air from the gap 852 is performed. As a result, the holding tool 84 sucks and holds the plate member 131 of the turntable 13.

In the center of the inner member 842, a recessed portion 853 for accommodating the central resin portion 132 of the turntable 13 is provided. In the recessed part 853, the projection 854 is provided in the several position of the circumferential direction centering on the center axis J2.

FIG. 9A is a diagram showing a state where the turntable 13 and the holding tool 84 face each other, and correspond to the state shown in FIG. 7E. When the metal mold | die separates and the gate trace 635 is exposed, as shown in FIG. 9A, the some processus | protrusion 854 of the holding | maintenance tool 84 is each to the some gate trace 635 of the center resin part 132, respectively. To face. Although the gate trace 635 is not limited to protruding higher than the upper surface 632 of the central resin portion 132, the case where the gate trace 635 protrudes above the upper surface 632 is depicted.

FIG. 9B is a diagram showing a state in which the holding tool 84 has moved toward the turntable 13, and corresponds to the state shown in FIG. 7F. When the holding tool 84 moves, the gate trace 635 collapses because the projection 854 contacts the gate trace 635. This prevents the gate trace 635 from protruding higher than the upper surface 632 of the central resin portion 132. At the same time, the turntable 13 is attracted and held by suction from the gap 852.

Suction from the gap 852 may be started before the gate trace 635 collapses. In addition, the suction from the gap 852 may be started after the gate trace 635 is collapsed and the gap 852 of the holding tool 84 is in contact with the turntable 13. As such, if the collapse of the gate trace 635 and the holding of the turntable 13 are performed substantially simultaneously, the term "simultaneous" need not be interpreted strictly.

The turntable 13 does not necessarily need to be released by the release pins 821. The holding tool 84 may directly hold and hold the turntable 13 on the movable die 82.

On the contrary, the holding tool 84 does not move toward the turntable 13, but the turntable 13 is pushed toward the holding tool 84 by holding the turntable 13 protruding from the release pin 821. It may be. In other words, the holding tool 84 and the turntable 13 may be moved relatively to each other.

When the turntable 13 is held by the holding tool 84, the transfer mechanism 83 moves the holding tool 84 so that the turntable 13 moves together with the holding tool 84 and the fixed mold 81. It takes out between the metal mold | die 82 (step S18). The turntable 13 taken out is accommodated in a predetermined container.

In practice, the arm 831 is provided with another holding tool for holding the plate member 131 together with the holding tool 84. When the holding tool 84 receives the turntable 13, another holding tool mounts the plate member 131 to the movable mold 82. And when the turntable 13 is accommodated in a predetermined container, the other holding | maintenance tool will hold the next plate member 131. As shown in FIG. As a result, a plurality of turntables 13 are sequentially manufactured with high efficiency. In addition, the annular rubber 133 is attached to the plate member 131 in a later step.

As described above, in the manufacture of the turntable 13, when the turntable 13 is taken out from the mold by the holding tool 84, the gate trace 635 is crushed by the holding tool 84. As a result, protrusion from the upper surface 632 of the gate trace 635 is prevented, and interference between the gate trace 635 and other structures such as a clamper is prevented. As a result, the process of checking the protrusion of the gate trace 635 and the secondary processing which collapses the protruding gate trace 635 become unnecessary. The manufacturing price of the turntable 13 is reduced. Poor appearance is also prevented.

Simultaneously with the collapse of the gate trace 635, the turntable 13 is held by the holding tool 84, thereby simplifying the operation of the mold and the conveying mechanism 83 of the manufacturing apparatus. In addition, by the suction, the turntable 13 is easily held by the holding tool 84.

The collapse of the gate trace 635 is performed at the projection 854. Therefore, the interference between the site around the gate trace 635 and the holding tool 84 can be easily avoided.

The protrusion of the gate trace 635 is likely to occur when a deep recess cannot be formed around the gate trace 635. In particular, when insert molding or out 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 collapse of the gate trace is particularly suitable for the production of such a resin molded article.

On the other hand, in the injection molding of the center resin part 132, in order to position the gate 811 above the plate member 131, resin can be filled in the space which forms a claw at an early time. Therefore, the lag 633 can be produced in the turntable 13 with high accuracy without any deterioration.

In addition, the gate trace 635 is arrange | positioned rather than the some claw 633 in the radial direction at the center axis J1 side. Thereby, resin can be easily filled in the site | part corresponding to the claw 633 of the cavity 89. As shown in FIG. In particular, since the gate is arranged so that the gate trace 635 is located between the plurality of claws 633 in the circumferential direction, the resin is more easily filled. The location of the weld line on the inclined surface 631 is also prevented.

When manufacturing the turntable, if the resin can be filled to the position of the claw 633 in the mold, the gate trace 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 effects on the manufacture of the turntable 13 are the same in the other examples below.

(Another example of the district)

10 is a diagram illustrating another example of the holding tool 84. The holding tool 84 has a mechanical zipper 843 and a zipper drive 844 instead of the outer member 841. Three or more mechanical zippers 843 are disposed around the central axis J2 at equal intervals. The mechanical zipper 843 advances and retracts about the central axis J2 by the zipper drive 844.

When the turntable 13 is held by the holding tool 84, the holding tool 84 is relatively close to the turntable 13. The protrusion 854 of the inner member 842 contacts the gate trace 635, and the gate trace 635 is collapsed by the protrusion 854. When the inner member 842 contacts the turntable 13, the mechanical zipper 843 moves toward the central axis J2. Thereby, the outer edge part of the turntable 13 is hold | maintained.

(Other examples of turntables and holding tools)

11 is a cross-sectional view illustrating another example of the turntable 13 and the holding tool 84. The turntable 13 does not have a plate member 131. The disc mounting portion 134 is made of resin. The central resin portion 132 does not have a claw 633. The gate trace 635 is formed on the upper surface of the disk mounting portion 134.

The holding tool 84 is provided with the outer member 841 and the inner member 842 similarly to FIG. 8A. The gap 852 is formed between the outer member 841 and the inner member 842. In this gap 852, suction to the turntable 13 of the holding tool 84 is performed. Thereby, the disk mounting part 134 is attracted and the turntable 13 is hold | maintained. The inner member 842 has a protrusion 854 at a position corresponding to the gate trace 635. As in FIG. 9B, the turntable 13 is held by the holding tool 84 at the same time as the collapse of the gate trace 635 by the projection 854.

The gate trace 635 may be formed on the turntable 13 as formed on the lower surface of the disk mounting portion 134.

(Other example of turntable 1)

12 is a diagram illustrating another example of the turntable 13. In FIG. 12, the disc portion 211, which is a cover portion of the rotor holder 21, serves as the plate member 131 of FIG. 2. The rotor holder 21 is a metal member which press-molded the plate-shaped member to the substantially cylindrical shape with a cover. The shape and other structure of the center resin part 132 are the same in FIG. Although the manufacturing method of the turntable 13 is substantially the same as the method shown in FIG. 6, the rotor holder 21 is mounted in a metal mold instead of the plate member 131, and the center resin part 132 is centered in the disk part 211. As shown in FIG. ) Is different from FIG. 6.

(Other example 2 of turntable)

13 is a diagram illustrating still another example of the turntable 13. In comparison with the turntable 13 of FIG. 12, in the turntable 13 of FIG. 13, resin is formed up to the outer circumferential portion and the cylindrical portion 212 of the disc portion 211 of the rotor holder 21. In the turntable 13 of FIG. 13, like the turntable 13 of FIG. 12, the resin may not be molded on the cylindrical portion 212. In other words, the resin is molded at a portion including the disc portion 211 perpendicular to the central axis of the rotor holder 21. Hereinafter, the resin on the disc part 211 is called "the disc-shaped resin part 130".

The disk mounting part 134 is comprised by the outer peripheral part of the upper surface of the disk shaped resin part 130, and the annular rubber 133. As shown in FIG. The disk mounting part 134 may be only a part of the disk-shaped resin part 130, and components other than the annular rubber 133 may be provided on the contrary. The shape and other structure of the center resin part 132 are the same as that of FIG. Although the manufacturing method of the turntable 13 is substantially the same as the method shown in FIG. 6, it differs from FIG. 6 in that the rotor holder 21 is attached to a metal mold | die, and the shape of the cavity formed is different.

The gate traces may be provided not only on the upper or lower surface of the central resin portion 132 but also on the upper surface of the disk mounting portion 134. When the gate traces are provided on the lower surface of the central resin portion 132, the gate traces can be prevented from interfering with the gate traces and the stator 32 of the motor 1. The same applies to the example shown in FIG. 12 and FIG. 14 described later.

(Other example 3 of turntable)

14 is a diagram illustrating still another example of the turntable 13. In the turntable 13 of FIG. 14, similar to the turntable 13 of FIG. 13, resin is formed up to the outer circumferential portion and the cylindrical portion 212 of the disc portion 211 of the rotor holder 21. Hereinafter, the resin on the disc part 211 is called "the disc-shaped resin part 130".

As in FIG. 13, the outer peripheral portion of the upper surface of the disc-shaped resin portion 130 becomes the disk mounting portion 134 or a part thereof. In the disk mounting portion 134, steel balls 135 for holding a balance when the motor is driven are accommodated.

Differently from FIG. 13, the central resin portion 132 is a separate member from the disc shaped resin portion 130. The center resin part 132 is urged upward by the spring 136 which is an elastic member. The claw is not provided in the center resin part 132, but the 1st inclined surface 71 and the 2nd inclined surface 72 are provided. The first inclined surface 71 is a conical surface having 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 for guiding the center hole of the recording disk 9.

Inside the central resin portion 132, a yoke 137 and a clamp magnet 138 are disposed. Yoke 137 is fixed to shaft 41. The clamp magnet 138 is secured to the yoke 137. When the clamper is lowered from above in the disk drive device, the recording magnet 9 is fixed on the disk mounting portion 134 by attracting the clamp magnet 138 and the clamper to each other. At this time, the central resin portion 132 slightly lowers while being careful of the recording disk 9.

In the case of FIG. 14, in the injection molding of the resin product shown in FIG. 6, the resin part on the rotor holder 21 except the center resin part 132 is shape | molded. Hereinafter, this resin part is called rotor resin part 73. When the integral part of the rotor holder 21 and the rotor resin part 73 is manufactured, the spring 136, the center resin part 132, the yoke 137, the clamp magnet 138, etc. are assembled, and the turntable 13 is performed. ) Is manufactured.

The rotor resin portion 73 is preferably provided with a gate trace on the upper surface. However, as shown in FIG. 14, when resin 731 is provided also in the lower side through the opening provided in the disk part 211 of the rotor holder 21, the gate trace will be shown in the lower surface of the rotor resin part 73. It may be provided.

(Variation)

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 die 82. The gate 811 may be provided in both the stationary die 81 and the movable die 82. The gate trace can be provided at various positions above or below the turntable 13. The plate member 131 and the rotor holder 21 may be attached to the fixing die 81.

The contact portion that collapses the gate trace may be a flat portion instead of the protrusion 854. Crushing of the gate traces and holding of the turntable 13 by the holding tool 84 may be performed separately.

Crushing of the gate trace by the holding tool can be used for the production of various resin molded articles other than the turntable 13.

The present invention can be used for the production of various resin products by injection molding.

1: motor 9: recording disc
10: recording disc drive device 11: access unit
12 housing 13 turntable
21: rotor holder 81: fixed mold
82: movable mold 83: conveyance mechanism
84: holding device 86: advance mechanism
89: cavity 91: disc center hole
130: disk-shaped resin portion 131: plate member
132: central resin portion 134: disk mounting portion
211: disc 631: slope
632: Top face 633: Claw
634 recesses 635 gate traces
811 gate 854 projection
J1: central axis S11 to S18: step

Claims (13)

Forming a cavity by molding the first mold having a gate and the second mold;
A step of molding a resin molded article by injecting a resin into the cavity from the gate;
Separating the first mold and the second mold to expose a gate trace of the resin molded article;
Inserting a holding tool between the first mold and the second mold;
Crushing the gate trace by bringing the holding tool into contact with the gate trace of the resin molded article;
Holding the resin molded article in the holding tool;
And taking out the resin molded article between the first mold and the second mold together with the holding tool.
Method for producing a resin molded article. The method of claim 1,
The process of collapsing the said gate trace and the process of holding the said resin molded article are performed simultaneously.
Method for producing a resin molded article. The method of claim 2,
In the step of crushing the gate traces, the holding tool adsorbs and holds the resin molded article
Method for producing a resin molded article. The method according to any one of claims 1 to 3,
The holding tool is provided with a projection to collapse the gate trace
Method for producing a resin molded article. The manufacturing method of the resin molded article of any one of Claims 1-3 is provided,
The resin molded article is a turntable provided in a motor for recording disk drive,
The gate trace is provided above or below the turntable.
Method of making a turntable. The method of claim 5, wherein
Before the process of forming the cavity, further comprising the step of attaching a metal member press-molded a plate or plate-shaped member to the first mold or the second mold,
In the step of molding the resin molded article, a resin is molded on the metal member.
Method of making a turntable. The method according to claim 6,
The metal member is approximately disk-shaped or substantially cylindrical with a lid,
In the step of molding the resin molded article, a central resin portion is molded in the center of the metal member,
The periphery of the said central resin part of the said metal member is a disk mounting part or a part in which a recording disk is mounted,
The central resin portion includes an approximately circular upper surface and an inclined surface that is separated from the central axis in a downward direction from the outer edge of the upper surface and guides the central hole of the recording disc.
Method of making a turntable. The method according to claim 6,
The metal member is approximately disk-shaped or substantially cylindrical with a lid,
In the step of molding the resin molded article, a disc-shaped resin portion is molded at a portion including a disc portion substantially perpendicular to the central axis of the metal member,
The outer peripheral portion of the upper surface of the disc-shaped resin portion is a disk mounting portion or part thereof on which a recording disk is mounted.
Method of making a turntable. The method of claim 8,
The central resin portion of the disc-shaped resin portion includes an approximately circular upper surface and an inclined surface that is separated from the central axis in a downward direction from the outer edge of the upper surface and guides the center hole of the recording disc.
Method of making a turntable. The method of claim 7, wherein
It is further provided with the some claw which has the part isolate | separated from the said center axis | shaft as said center resin part goes downward in an outer peripheral part,
The said gate trace is formed in the recessed part provided in the said upper surface or the said inclined surface, and is located in the said central axis side rather than the said some claw in radial direction.
Method of making a turntable. The method of claim 10,
In the circumferential direction, the gate trace is located between the plurality of claws
Method of making a turntable. A motor having a turntable manufactured by the manufacturing method of claim 5,
An access unit that reads and / or writes information to a recording disc mounted on the turntable;
A housing accommodating the motor and the access unit
Recording disc drive device. A first mold having a gate for injecting resin,
With the second mold,
A retraction mechanism for retracting the second mold relative to the first mold;
A holding tool for holding a resin molded article molded in a cavity between the first mold and the second mold after separation of the first mold and the second mold;
It is provided with the conveyance mechanism which takes out the said resin molded article between the said 1st metal mold | die and the said 2nd metal mold | die by moving the said holding tool,
The holding tool includes a contact portion that collapses the gate trace by contacting a gate trace of the resin molded article exposed after separation of the first mold and the second mold.
The manufacturing apparatus of a resin molded article.

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