JP2007328892A - Reel and recording tape cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reel and a recording tape cartridge which can improve the strength of the hub and lengthen the life of the metal die for molding the hub. <P>SOLUTION: By providing lightening holes 40A in the axial direction of the hub 40, shrinkage can be prevented on the surface of the hub 40 even when making it thick. Since the holes 40A are made almost cylindrical in shape, they can be formed by using round pins in the metal die for molding the hub 40. The round pins have a smaller sliding resistance than square pins, and the mold-releasing is improved when taking out the molds from the metal die while lengthening the life of the metal die. Further, the round pins are easy for machining as compared with the square pins and reduce the metal die costs. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a reel and a recording tape cartridge around which a recording tape such as a magnetic tape is wound.

  As an external recording medium such as a computer, for example, a recording tape cartridge in which a reel on which a magnetic tape is wound is accommodated in a case is known. The reel includes a hub that forms an axial center of the reel and on which the magnetic tape is wound around the outer periphery, and an upper flange and a lower flange that project radially outward from both axial ends of the hub.

  Conventionally, a recording tape in which a recording tape such as a magnetic tape used as a data recording / reproducing medium of a computer or the like is wound around a single reel and the reel is rotatably accommodated in a case made of a synthetic resin. Cartridges are known. The leading end (free end) of the recording tape is provided with a leader member such as a leader pin, a leader tape, or a leader block. The leader member provided on the drive device side pulls out the leader tape from the opening of the recording tape cartridge. The recording tape fixed thereto is wound around a take-up reel on the drive device side.

  In such a recording tape cartridge reel, the recording tape is usually wound around the outer peripheral surface of the hub. An upper flange and a lower flange are provided at the top and bottom of the hub, respectively, and the recording tape is held so that the height position of the recording tape in the vertical direction is regulated and the winding shape is good. Stability is improved, and further, excessive damage is prevented when not in use.

  By the way, the hub is often formed in a bottomed cylindrical shape that is open on one side in the axial direction and closed on the other side. The hub formed in such a bottomed cylindrical shape is easily deformed on the opening end side having low strength due to the winding pressure of the magnetic tape. Thus, when a hub deform | transforms, the flange provided in the opening end side of this hub deform | transforms in the direction which contacts the width direction edge part (edge) of a magnetic tape.

  For this reason, for example, in Patent Document 1, a plurality of reinforcing ribs extending along the axial direction of the hub and extending toward the axial center of the hub are formed on the inner peripheral surface of the hub, and adjacent reinforcing ribs are formed. The strength of the hub is improved by providing a reinforcing wall member that connects the tip portions and faces the inner peripheral surface of the hub.

However, in order to provide the reinforcing rib and the reinforcing wall member as described above, in the mold for forming the hub, a plurality of corners for providing a space surrounded by the adjacent reinforcing rib and the reinforcing wall member are provided. A pin is required, but the shape is complicated and the processing cost of the mold becomes high. Further, by providing a plurality of square pins, the releasability when the hub is released from the mold is deteriorated, and the life is shortened.
JP 2005-339668 A

  An object of the present invention is to obtain a reel and a recording tape cartridge that can improve the strength of the hub and extend the life of a mold for molding the hub in consideration of the above facts.

  To achieve the above object, according to the first aspect of the present invention, in the reel, a hub around which the recording tape is wound, a first flange integrally formed on one end side of the hub, and the other end of the hub. A plurality of hollow portions formed in a plurality of recesses along the axial direction of the hub, and a width of the recording tape wound around the hub and welded to the end surface of the other end of the hub And a second flange for holding the direction end portion together with the first flange.

  In the first aspect of the invention, the first flange is integrally formed on one end side of the hub, and the second flange is welded to the end face on the other end side of the hub. A plurality of hollow portions having a substantially cylindrical shape are formed in the end surface on the other end side of the hub along the axial direction of the hub.

  For example, if the thickness of the hub is thicker than the flange, there is a concern that the outer peripheral surface of the hub may sink due to heat shrinkage after molding, but a hollow portion is provided along the axial direction of the hub. As a result, sink marks can be prevented from occurring on the outer peripheral surface of the hub. In other words, the thickness of the hub can be made larger than the thickness of the flange, and the strength of the hub can be improved.

  Furthermore, by making the shape of the lightening portion into a substantially columnar shape, the die for forming the hub uses a round pin to form the lightening portion. The round pin has a sliding resistance smaller than that of the square pin, and the releasability when the molded product is released from the mold is improved, and accordingly, the life of the mold can be improved. Further, the round pin is easier to process than the square pin, and the die cost can be reduced.

  According to a second aspect of the present invention, in the reel according to the first aspect, the thinned portions are arranged in a line along the circumferential direction of the hub.

  According to a third aspect of the present invention, in the reel according to the first aspect, the thinned portions are arranged in a staggered manner along the circumferential direction of the hub.

  According to a fourth aspect of the present invention, in the reel according to any one of the first to third aspects, the diameter of the thinned portion is about 30 to 40% of the thickness of the hub. .

  In the invention according to the fourth aspect, the diameter of the lightening portion suitable for preventing sink marks generated on the outer peripheral surface of the hub is defined.

  According to a fifth aspect of the present invention, in the reel according to any one of the first to fourth aspects, the hole area of the cutout portion / the cross-sectional area of the hub is about 15%. .

  If the diameter of the thinned portion is too large with respect to the thickness of the hub, the strength of the hub cannot be maintained. Defines the cross-sectional area of the hub.

  According to a sixth aspect of the invention, a recording tape cartridge includes the reel according to any one of the first to fifth aspects.

  Since the present invention has the above configuration, the strength of the hub can be improved, and the life of the mold for molding the hub can be extended.

  A reel 10 according to an embodiment of the present invention will be described with reference to FIGS. First, the substantially entire configuration of the recording tape cartridge 12 to which the reel 10 is applied will be described, and then the reel 10 will be described in detail. For convenience of explanation, the loading direction of the recording tape cartridge 12 to the drive device indicated by the arrow A is the front direction (front side), and the arrow B and arrow C directions orthogonal to the arrow A are the right direction and the upward direction, respectively.

(Configuration of recording tape cartridge)
FIG. 1 is an exploded perspective view of the recording tape cartridge 12. The recording tape cartridge 12 is configured by rotatably accommodating a single reel 10 around which a magnetic tape T as a recording tape, which is an information recording / reproducing medium, is wound in a substantially rectangular case 14 in plan view. Yes.

  An opening 16 for drawing the magnetic tape T out of the case 14 is provided at the front end of the right side wall of the case 14. The opening 16 is closed by a door 18 when the recording tape cartridge 12 (magnetic tape T) is not used, and is opened within the drive device when the recording tape cartridge 12 is used.

  A leader pin 20 as a leader member is attached to the tip of the magnetic tape T. The leader pin 20 is formed in a small columnar shape, and flange portions 20A provided at both longitudinal ends projecting up and down from the widthwise end portion of the magnetic tape T are hooked on the drawing member of the drive device. Thus, the magnetic tape T is pulled out from the case 14.

  The case 14 is configured by joining an upper case 22 and a lower case 24. The upper case 22 is configured by a substantially frame-shaped peripheral wall 22B erected along the outer edge of the top plate 22A having a substantially rectangular shape in plan view, and the lower case 24 is a bottom plate having a shape substantially corresponding to the top plate 22A. A peripheral wall 24B is erected along the outer edge of 24A. The case 14 has a substantially box-like shape in which the upper case 22 and the lower case 24 are joined by ultrasonic welding, screwing or the like with the opening end of the peripheral wall 22B and the opening end of the peripheral wall 24B abutting each other. Is formed.

  The opening 16 is formed in a substantially rectangular shape in a side view, and opens rightward at the front end of the right side wall 14A (the right side wall of the case 14 including the peripheral wall 22B and the peripheral wall 24B) along the arrow A direction in the case 14. Yes. The top plate 22A and the bottom plate 24A are provided with pin receiving recesses 26 for receiving the flange portions 20A of the upright leader pins 20, respectively. Each pin receiving recess 26 is also opened rightward in the vicinity of the front end of the opening 16 so that the leader pin 20 can enter and leave the case 14 via the opening 16.

  Further, a leaf spring 28 is attached near the front end of the case 14, and the leaf spring 28 is provided with a pair of upper and lower arms 28 </ b> A. The leaf spring 28 is configured to hold the leader pin 20 against the case 14 by engaging the tip of each arm 28 </ b> A with the flange portion 20 </ b> A of the leader pin 20. This holding state is configured to be released by pulling the leader pin 20 rightward with a force equal to or greater than a predetermined value.

  The door 18 for opening and closing the opening 16 is formed in a substantially rectangular flat plate shape capable of closing the opening 16 alone. The upper and lower ends of the door 18 slidably enter guide grooves 30 provided on the top plate 22A and the bottom plate 24A along the open surface of the opening 16 and the right side wall 14A.

  Thus, the door 18 is configured to be able to selectively take a closed position for closing the opening 16 and an open position for opening the opening 16 by sliding in the front-rear direction while being guided by the guide groove 30. . The door 18 is biased forward by a coil spring 32 which is a biasing member provided between the case 14 and is normally positioned at the closed position by this biasing force. At the front end of the door 18, an operation portion 18 </ b> A is provided so as to protrude rightward, and the door 18 is moved to the open position against the urging force of the coil spring 32 by pressing the operation portion 18 </ b> A rearward. Can be done.

  Further, a gear opening 34 for exposing a reel gear 50 (see FIG. 2), which will be described later, of the reel 10 is provided at the center of the bottom plate 24A of the case 14. The reel 10 is configured to be driven to rotate in a non-contact manner in the case 14 by rotating a drive gear of a drive device meshed with the reel gear.

  Further, the case 14 is provided with a guide regulating wall 36 that is partially erected from the top plate 22A and the bottom plate 24A along a circumference coaxial with the gear opening 34 and is configured to abut the upper and lower ends. . The guide regulating wall 36 is configured to prevent the dust 10 and the like from entering the installation area of the reel 10 while suppressing the rattling of the reel 10 and having the end portions continuous to the peripheral walls 22B and 24B.

(Reel configuration)
2 and 3 are sectional views of the reel 10. The reel 10 is roughly divided into an annular upper flange 48, a substantially cylindrical hub 40, and a substantially disk-shaped lower flange 46. The hub 40 and the lower flange 46 include, for example, 10% glass reinforcing fiber. It is integrally formed of a resin such as polycarbonate.

  The thickness of the hub 40 is about 3.5 to 4.5 times the thickness of the lower flange 46. In addition, a columnar hollow hole (thickening part) 40A is formed along the axial direction at the center part in the radial direction of the hub 40, and at a predetermined pitch in a line along the circumferential direction of the hub 40. Several are arranged. As an example, the outer diameter φ of the hub 40 is 440 mm, the wall thickness t is 4 mm, the hole diameter φ of the hollow hole 40A is 1.5 mm, and the number of holes is 40.

  On the other hand, an annular positioning rib 48 </ b> A hangs down from the central portion of the upper flange 48, and can be disposed inside the inner peripheral surface of the hub 40. An annular welding rib (not shown) projects from the center of the upper flange 48 outside the positioning rib 48A, and engages the positioning rib 48A of the upper flange 48 on the inner peripheral surface of the hub 40. When the welding rib is melted by ultrasonic welding or the like with the welding rib in contact with the upper end surface of the hub 40, the upper flange 48 is welded to the hub 40.

  As described above, the upper flange 48 is integrated with the lower flange and the hub 40 in a state where the upper flange 48 is coaxially disposed on the lower flange and the hub 40. The magnetic tape T is wound around the outer peripheral surface of the hub 40, and the lower flange 46 and the upper flange 48 are displaced in the width direction of the magnetic tape T wound around the hub 40 (the axial direction of the hub 40). To regulate.

  On the other hand, an annular reel gear 50 is provided on the outer surface (lower surface) of the center portion of the lower flange 46. The reel gear 50 is exposed from the gear opening 34 of the case 14 (see FIG. 1) and moves relative to the rotation shaft of the drive device along the axial direction so that the reel gear 50 moves relative to the drive gear provided at the tip of the rotation shaft. Engagement and disengagement are possible.

  A reel plate 52 made of a magnetic material is integrally provided inside the reel gear 50 in the radial direction by insert molding. The reel plate 52 is configured to be attracted and held in a non-contact manner by a magnet provided at the tip of the rotating shaft.

  Further, a lock mechanism (not shown) for preventing the reel 10 from rotating when the magnetic tape T is not used is provided inside the inner surface (upper surface) of the lower flange 46. The lock mechanism has a lock member that is prevented from rotating with respect to the case 14, and supports the lock member so as to be able to contact and separate from the reel 10. Further, the lock member engages with an engagement portion (not shown) of the lower flange 46 by contact and separation with respect to the reel 10 and releases the rotation lock position where the rotation of the reel 10 with respect to the case 14 is prevented. Thus, the release position allowing the rotation of the reel 10 can be taken.

  For this reason, the lower flange 46 is provided with an engaging portion with which the lock member is engaged, and an operation hole 54 is formed for the lock release member of the drive device to operate the lock member from the outside. In this embodiment, the configuration in which the operation hole 54 is provided in the formation part of the reel gear 50 is illustrated. However, for example, the operation hole 54 may be provided in the central portion of the center portion of the lower flange 46.

  As described above, the lower flange 46 has a function in which the reel gear 50 is formed and rotational force is transmitted from the drive device, a function of closing the gear opening 34 of the case 14 when not in use, and a lock member to engage the reel 10. A function for preventing rotation of the case 14 is performed.

  Next, the operation of the embodiment of the present invention will be described.

  The reel 10 shown in FIGS. 1 and 2 has a case 14 when a recording tape cartridge 12 is loaded into a drive device when information is recorded on the magnetic tape T or when information recorded on the magnetic tape T is reproduced. The rotation lock with respect to is released, and the reel 10 rotates in the case 14 by rotating the rotating shaft meshing with the reel gear 50.

  At this time, the leader pin 20 already taken out from the opening 16 is held on the take-up reel of the drive device, and the take-up reel rotates in synchronism with the reel 10 so that the magnetic tape T is sequentially drawn out from the case 14. It is. A recording / reproducing head arranged along a predetermined tape path writes information on the magnetic tape T or reads information recorded on the magnetic tape T. After use of the magnetic tape T, the reel 10 returns to the initial state of winding the magnetic tape T.

  By the way, in the present invention, as shown in FIGS. 2 and 3, a lightening hole 40 </ b> A is provided along the axial direction of the hub 40. In order to improve the strength of the hub 40, the thickness of the hub 40 is about 3.5 to 4.5 times the thickness of the lower flange 46. However, when the thickness of the hub 40 is increased, molding is performed. There is a concern that sinking may occur on the outer peripheral surface of the hub 40 due to subsequent heat shrinkage. However, it is possible to prevent sink marks on the outer peripheral surface of the hub 40 by providing the lightening holes 40 </ b> A along the axial direction of the hub 40. In other words, the thickness of the hub 40 can be increased and the strength of the hub 40 can be improved by providing the lightening holes 40A along the axial direction of the hub 40.

  Further, by making the shape of the lightening hole 40A into a substantially cylindrical shape, a metal mold (not shown) for forming the hub 40 uses a round pin to form the lightening hole 40A. The round pin has a smaller sliding resistance than the square pin, and the releasability when the molded product is released from the mold is improved. For this reason, the lifetime of a metal mold | die can be improved. Further, the round pin is easier to process than the square pin, and the die cost can be reduced.

  By the way, in order to suppress deformation due to sink marks or the like of the hub 40, the hole diameter of the lightening hole 40A is preferably about 30 to 40% of the thickness of the hub 40. However, in order to increase the rigidity of the hub 40, it is preferable that the hole diameter 40A has a small hole diameter and a small number of holes. For this reason, it is necessary to obtain an appropriate condition of the lightening hole 40A for satisfying the above condition with respect to the thickness of the hub 40.

  For example, FIG. 4 and FIG. 5 show the deformation amount of the hub when a predetermined surface pressure is applied to the upper end surface of the hub having a thickness of 4 mm and a thinned portion provided in the center in the radial direction. FIG. 4 shows the results obtained by measuring the deformation amount of the hub by changing the hole diameter, assuming that the number of holes of the lightening holes is 40, and FIG. 5 shows the results obtained according to the hole diameter and the number of holes. The result of measuring the deformation amount of the hub by changing the number of holes with the hole diameter of the hollow hole being 1.5 mm is shown.

  As can be seen from FIG. 4 and FIG. 5, when a predetermined surface pressure is applied to the upper end surface of the hub in a state where no hole is formed, the deformation amount of the hub is about 0.03 mm, It can be seen that changing the hole diameter has a greater effect on the hub than changing the number of lightening holes.

  Next, FIG. 6 shows the result of obtaining the deformation amount of the hub by changing the ratio of the total area of the hollow holes to the cross-sectional area of the hub. Here, it can be seen that if the total area of the hollow holes / the cross-sectional area of the hub exceeds 0.15, the deformation amount of the hub exceeds 0.07 mm.

  For this reason, it is necessary to make the total area of the hollow holes / the cross-sectional area of the hub up to about 15%. However, as described above, when considering sinking of the hub 40, the original purpose of preventing sinking of the hub 40 can be achieved when the total area of the hollow holes / cross-sectional area of the hub is too small. It will disappear. For this reason, it is preferable that the total area of the hollow holes / the cross-sectional area of the hub be about 10 to 15%.

  Here, assuming that a predetermined surface pressure acts on the upper end surface of the hub 40, considering the rigidity of the hub 40, the lightening hole 40A is formed in the central portion in the radial direction of the hub 40. You may arrange | position in the radial inside of the hub 40, or the outer side.

  Furthermore, in this embodiment, as shown in FIG. 3 and FIG. 7, the lightening holes 40A are provided in a row along the circumferential direction of the hub 40, but as shown in FIG. It is also possible to arrange the hollow holes 40A alternately on the inside so as to form a staggered pattern.

  Further, in each of the above embodiments, the example in which the reel 10 is applied to the recording tape cartridge 12 configured by housing a single reel in the case 14 is shown, but the present invention is not limited to this, for example, The reel 10 may be applied to a two-reel type recording tape cartridge in which two reels are accommodated in a case.

  Furthermore, although the case where the hub is integrally formed with the lower flange has been described in this embodiment, the hub may be integrally formed with the upper flange.

1 is an exploded perspective view showing an overall configuration of a recording tape cartridge according to an embodiment of the present invention. It is a schematic sectional drawing of the reel which concerns on embodiment of this invention. It is a perspective view of the hub of a reel concerning an embodiment of the invention. It is a graph which shows the result of having changed the hole diameter and measuring the deformation amount of the hub, assuming that the number of the hollow holes of the hub of the reel according to the embodiment of the present invention is 40. It is a graph which shows the result of having measured the deformation amount of the hub by changing the number of holes and setting the hole diameter of the hollow hole of the hub of the reel according to the embodiment of the present invention to φ1.5 mm. It is a graph which shows the result of having calculated | required the deformation amount of the hub by changing the ratio of the total area of the hollow hole with respect to the cross-sectional area of the hub of the reel which concerns on embodiment of this invention. It is a top view of the hub of the reel which concerns on embodiment of this invention. It is a top view which shows the modification of the hub of the reel which concerns on embodiment of this invention.

Explanation of symbols

10 reel 12 recording tape cartridge 40 hub 40A lightening hole (thickening part)
46 Lower flange (first flange)
48 Upper flange (2nd flange)

Claims (6)

A hub around which recording tape is wound;
A first flange integrally formed on one end of the hub;
On the end face on the other end side of the hub, a plurality of hollow portions having a substantially cylindrical shape that are recessed in a plurality along the axial direction of the hub;
A second flange that is welded to an end face on the other end side of the hub and holds the widthwise end of the recording tape wound around the hub together with the first flange;
A reel comprising:   The reel according to claim 1, wherein the thinned portions are arranged in a line along a circumferential direction of the hub.   The reel according to claim 1, wherein the thinned portions are arranged in a staggered manner along a circumferential direction of the hub.   The reel according to any one of claims 1 to 3, wherein a diameter of the lightening portion is about 30 to 40% of a thickness of the hub.   The reel according to any one of claims 1 to 4, wherein a hole area of the lightening portion / a cross-sectional area of the hub is about 10 to 15%.   A recording tape cartridge comprising the reel according to claim 1.

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