JP2005319773A - Resin molded article, mold and recording tape cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a resin molded article capable of forming the inner face side or the outer face side at right angles and whose design aspect is taken into consideration. <P>SOLUTION: A condition provided with a draft angle can be made by changing an inclination of a parting face PL of the outer face and the inner face between a main body part 40 and a folding part 42 to the mold releasing direction of a mold 46 molding a door member 30. It is possible thereby to make an angle constituted by the outer face of the main body part 40 and the outer face of the folding part 42 at right angles, and when the door member 30 is fitted to a case, the outer face of the folding part 42 does not dent to the peripheral wall of the case and the appearance of the whole case can be held. In addition, a gate 68 connecting a runner 54 with a gate port 66 is curved and it is tapered off with becoming to the gate port 66 side to get in the inner face side of the main body part 40, and a resin is fed directly into the main body part 40, so that a mark of the gate can not be generated on the outer face side of the main body part 40 and the folding part 42. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resin molded product, a mold, and a recording tape cartridge using the resin molded product.

  For example, a recording tape cartridge 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 synthetic resin case. An opening for drawing the recording tape to the outside is formed (for example, Japanese Patent Application No. 2004-50169).

  The opening is formed at the corner of the case formed so that the adjacent front wall and side wall are orthogonal to each other, and the leader tape is fixed to the end of the recording tape and arranged along the side wall from the opening. Is to be pulled out. The opening can be opened and closed by a door member formed in an L shape with the main body and the bent portion. When the recording tape cartridge is not used, the opening is closed, and the recording tape cartridge is used. Sometimes the opening is opened.

  Here, a shaft support is provided at the end of the main body of the door member so as to be rotatably supported with respect to the case so as to open and close a part of the opening located on the front wall side of the case. It has become. On the other hand, the bent portion covers the remaining part of the opening located on the side wall of the case and is locked to the inner edge of the opening.

By the way, as shown in FIG. 12, when making the main-body part 204 shape | molded along the direction orthogonal to the moving direction (arrow A direction) of the metal mold | die 202 which shape | molds the door member 200, a metal mold | die is made. In order to release the door member 200 from the mold 202 due to the structure of 202, it is necessary to provide so-called draft angles (θ ₁ , θ ₂ ) in the bent portion 206.

  That is, the angle formed by the outer surface of the main body portion 204 and the outer surface of the bent portion 206 is smaller than 90 ° (the inner surface of the main body portion 204 and the inner surface of the bent portion 206 are formed. The angle becomes greater than 90 °). For this reason, when the opening part of a case (illustration omitted) is obstruct | occluded with the door member 200, the door member 200 will be in the state slightly dented from the front wall or side wall of the case, and is unpreferable on an external appearance.

  On the other hand, in the gate method in which resin is injected into the mold 202 when the door member 200 is molded, the door member 200 is exposed to the exterior of the case, and therefore a gate port (resin injection port) is provided in a portion other than the design surface. Must be provided.

  Here, if a gate port is provided on the upper surface of the bearing portion 208 of the door member 200, the orientation (flow) of the resin is inclined with respect to the longitudinal direction of the door member 200, so warping or twisting is caused. There is a problem that it is likely to occur and the dimensional stability of the door member 200 is not good. Further, since the pressure applied by molding is the largest at the gate port, residual stress tends to occur. Thus, when residual stress is generated around the gate opening, cracks are generated due to changes over time, and the periphery of the gate opening becomes brittle.

  In view of the above facts, the present invention has an object to obtain a resin molded product that can form the inner surface side or the outer surface side at a right angle and that takes the design surface into consideration.

  The invention according to claim 1 is composed of a main body portion and a bent portion, is an L-shaped resin molded product in a side view, and an angle formed by an outer surface of the main body portion and the bent portion; At least one of the angles formed by the inner surface of the main body portion and the bent portion is formed at a right angle, and a gate mark in which resin is injected is provided on the inner surface side or the outer surface side that does not become the design surface of the main body portion and the bent portion. It is characterized by.

  In the first aspect of the present invention, at least one of an angle formed by the outer surface of the main body portion and the bent portion forming the L shape in a side view and an angle formed by the inner surface of the main body portion and the bent portion is set. It is formed at a right angle.

  For example, when an opening provided in a corner portion of a case formed in a state in which adjacent peripheral walls are orthogonal to each other is closed with this resin molded product, the angle formed by the outer surface of the main body portion and the bent portion is set at a right angle. By forming, the resin molded product can be flush with the peripheral wall of the case, and the aesthetic appearance of the entire case is maintained.

  In addition, the angle formed by the outer surface of the main body portion and the bent portion is set to a right angle, and the angle formed by the inner surface of the main body portion and the bent portion is set to a right angle, thereby making it possible to steal meat for providing a draft angle. Since it is not necessary to provide, the functional design dimension of the door member can be secured.

  Furthermore, a trace of a gate port into which resin is injected, that is, a so-called gate trace, is provided on the inner surface side or the outer surface side that does not become the design surface of the main body portion and the bent portion. In other words, in a mold for molding a resin molded product, by providing a gate port for injecting resin on the opposite side of the design surface of the resin molded product, there is no gate mark on the design surface side of the resin molded product. The appearance of the entire case is improved, not just the resin molded product.

  According to a second aspect of the present invention, in the resin molded product according to the first aspect, the gate mark is provided at the center of one end of the main body in the longitudinal direction.

  In the invention according to claim 2, the resin for molding the resin molded product by providing the gate mark at the center of one end in the longitudinal direction of the main body, that is, by providing the gate port at the center of one end of the main body in the longitudinal direction. Since this orientation occurs along the longitudinal direction of the resin molded product, the dimensional stability of the resin molded product can be obtained.

  The invention according to claim 3 is a mold that is configured by a main body portion and a bent portion, and that molds an L-shaped resin molded product in a side view, at least with respect to the mold release direction of the mold. A parting surface is formed such that an outer surface or an inner surface of the main body portion and the bent portion is inclined.

  In order to release the resin molded product from the mold due to the structure of the mold when the main body is molded along the direction orthogonal to the mold release direction of the mold for molding the resin molded product. Therefore, it is necessary to provide a so-called draft angle at the bent portion.

  However, in the invention according to claim 3, at least the main body portion is formed by forming the parting surface so that at least the outer surface or the inner surface of the main body portion and the bent portion is inclined with respect to the mold release direction. The outer surface or the inner surface of the bent portion can be in a state in which a draft angle is provided in the mold release direction from the mold.

  That is, a draft can be substantially obtained only by changing the inclination of at least the outer surface or inner parting surface of the main body portion and the bent portion. Thereby, the angle comprised by the outer surface or inner surface of a main-body part and a bending part can be made into a right angle.

  Invention of Claim 4 WHEREIN: In the metal mold | die of Claim 3, the runner in which resin flows, the said main-body part, and the gate port located in the inner surface side or outer surface side which does not become the design surface of the said bending part are provided. The gate to be connected is curved and formed so that the gate opening side is tapered.

  In the invention according to claim 4, by forming the gate connecting the runner through which the resin flows and the gate port located on the opposite side of the design surface of the resin molded product, the gate port side is tapered, There is no need to provide a so-called discard boss on the opposite side of the design surface of the resin molded product. For this reason, there is no need for gate cutting in a state where the resin molded product is released from the mold, and workability is improved.

  The invention according to claim 5 includes a case in which a reel on which a recording tape is wound is rotatably accommodated, and an opening formed at a corner of the case and capable of pulling out the recording tape. In the recording tape cartridge, the door member that opens and closes the opening is the resin molded product according to claim 1 or 2.

  According to a fifth aspect of the present invention, there is provided a door member that is formed at a corner portion of a case in which a reel around which a recording tape is wound is rotatably accommodated, and that opens and closes an opening through which the recording tape can be drawn. By using the resin molded product according to 2, an effect similar to that of the first aspect can be obtained.

  Since the present invention has the above-described configuration, in the inventions according to claims 1 and 5, the openings provided at the corners of the case formed in a state where the adjacent peripheral walls are orthogonal to each other are closed with this resin molded product. In this case, the resin molded product can be flush with the peripheral wall of the case, so that the aesthetic appearance of the entire case is maintained. In addition, the angle formed by the outer surface of the main body portion and the bent portion is set to a right angle, and the angle formed by the inner surface of the main body portion and the bent portion is set to a right angle, thereby making it possible to steal meat for providing a draft angle. Since it is not necessary to provide, the functional design dimension of the door member can be secured. Furthermore, by providing a gate port for injecting resin on the opposite side of the design surface of the resin molded product, no gate marks are generated on the design surface side of the resin molded product, so that not only the resin molded product but also the entire case Improving the aesthetics.

  In the invention according to claim 2, since the orientation of the resin for molding the resin molded product occurs along the longitudinal direction of the resin molded product by providing the gate port in the center of one end portion in the longitudinal direction of the main body, the resin Dimensional stability of the molded product can be obtained.

  In the invention according to the third aspect, the draft can be substantially obtained only by changing the inclination of the parting surfaces of the main body part and the bent part. Thereby, the angle comprised by a main-body part and a bending part can be made into a right angle.

  In the invention according to claim 4, by forming the gate connecting the runner through which the resin flows and the gate port located on the opposite side of the design surface of the resin molded product, the gate port side is tapered, Since there is no need to provide a so-called discard boss on the opposite side of the design surface of the resin molded product, there is no need for gate cutting when the resin molded product is released from the mold, and workability is improved.

  First, an outline of a recording tape cartridge according to an embodiment of the present invention will be described. For convenience of explanation, the loading direction of the recording tape cartridge into the drive device is indicated by an arrow A, which is the forward direction. Moreover, the arrow B is set to the left direction, and the front / rear, left / right, and upper / lower directions are expressed based on the arrow B. In the following, the “radial direction” refers to a direction parallel to a direction radially outward from the axial center line of the reel accommodated in the case.

  As shown in FIG. 1, the recording tape cartridge 10 has a substantially rectangular box-shaped case 12. In this case 12, an upper case 14 and a lower case 16 made of a resin such as PC are connected to a peripheral wall 14B erected on the periphery of the top plate 14A and a peripheral wall 16B erected on the periphery of the bottom plate 16A. In the contacted state, they are joined by ultrasonic welding, screwing or the like.

  In the case 12, only one reel (not shown) around which a recording tape T such as a magnetic tape is wound is rotatably accommodated. In addition, an opening 20 is formed in the vicinity of the corner portion 12C on the left front side of the recording tape cartridge 10 for drawing out the recording tape T wound around the reel to the outside.

  That is, an opening 20 is formed across the front wall 12A and the left side wall 12B adjacent to each other in a state orthogonal to the corner part 12C. The leader tape 22 is pulled out.

  The leader tape 22 is a drawn member with which a drawing member (not shown) of the drive device is engaged in order to pull out the recording tape T, and a hole 22A for engaging the drawing member is formed near the tip of the leader tape 22. Yes. Overhanging portions 22B projecting in the vertical direction are formed on both the upper and lower sides slightly closer to the rear than the tip of the hole 22A. The overhanging portion 22 </ b> B is housed (inserted) in housing recesses 24 formed on the inner surface of the upper case 14 and the inner surface of the lower case 16, whereby the leader tape 22 is held in the case 12.

  The opening 20 is closed by the door member 30 when the recording tape cartridge 10 is not used. The door member 30 includes a main body portion 40 and a bent portion 42, has substantially the same shape and size as the opening 20, and is formed at a right angle in a side view. The door member 30 is preferably molded from an olefin resin such as POM, but may be molded from a resin such as PC.

  In addition, a support shaft 26 serving as a pivot point of the door member 30 is provided so as to protrude from the front wall 12 </ b> A side of the upper case 14 and the lower case 16. The support shaft 26 has a cylindrical boss 26A on the upper case 14 side and a columnar boss 26B on the lower case 16 side. The tip (upper end) of the boss 26B on the lower case 16 side is fitted into the boss 26A on the upper case 14 side, whereby the support shaft 26 is configured. Therefore, the diameter of the boss 26B is slightly smaller than the diameter of the boss 26A.

  Further, in the vicinity of the right end portion of the inner surface of the door member 30 (a position shifted to the left by a predetermined distance from the right end portion), three flat plate-like bearing portions 32 project in parallel. The bearing portions 32 project from both upper and lower end portions of the inner surface of the door member 30 and a midway portion slightly shifted from the center, and each bearing portion 32 has a through hole that is loosely fitted to the support shaft 26. Is drilled. Therefore, the door member 30 is rotatably supported by inserting the support shaft 26 into each through hole.

  In addition, annular convex portions 34 are formed around the through holes on the upper surface of the bearing portion 32 at the upper end and the lower surface of the bearing portion 32 at the lower end, respectively. The annular protrusions 34 come into contact with the upper case 14 and the lower case 16, respectively, so that the space between the upper end surface 30 </ b> A of the door member 30 and the upper case 14, and the lower end surface 30 </ b> B of the door member 30 and the lower case 16. A gap of about 0.3 mm to 0.5 mm is formed between the two.

  Further, on the inner surface of the door member 30 between the bearing portions 32, a raised portion 36 having an arc shape in a plan view along the peripheral surface of the support shaft 26 is formed. An opening / closing member (not shown) of the drive device engages (contacts and presses) on the back side of the raised portion 36, that is, near the right end portion of the outer surface of the door member 30 (right side including the bearing portion 32). The engaging recess (not shown) having a predetermined depth is formed.

  Further, a winding portion 28 </ b> A of a torsion spring 28 that constantly biases the door member 30 in the closing direction of the opening 20 is inserted into the support shaft 26. That is, the winding portion 28A of the torsion spring 28 is inserted and attached to the boss 26B having a smaller diameter while being held between the bearing portion 32 at the lower end portion and the bearing portion 32 at the midway portion. Yes. One end side of the torsion spring 28 is locked to a screw boss 38 (a screw boss protruding from the lower case 16) of the case 12, and the other end side is a right edge of the raised portion 36. It is locked to.

  Further, a stopper piece 44 is erected at the central portion of the right end portion of the inner surface of the door member 30, and a surface facing the bent portion 42 is formed in parallel with the bent portion 42. The stopper piece 44 can come into contact with the screw boss 38, and the movement of the door member 30 in the opening direction is restricted while the stopper piece 44 is in contact with the screw boss 38.

  With the configuration as described above, when the recording tape cartridge 10 is not used (not loaded in a drive device not shown), the door member 30 closes the opening 20 by the urging force of the torsion spring 28. The leader tape 22 is arranged along the left side wall 12B by holding (inserting) and holding the protruding portion 22B in the storage recess 24, and the reel is prevented from inadvertent rotation. .

  On the other hand, when data is recorded on the recording tape T of the recording tape cartridge 10 or data recorded on the recording tape T of the recording tape cartridge 10 is reproduced, the recording tape cartridge 10 is loaded into the drive device. That is, the recording tape cartridge 10 is inserted into the loading port (not shown) of the drive device from the front wall 12A side.

  Along with this loading, the door member 30 rotates about the support shaft 26 against the biasing force of the torsion spring 28, the opening 20 is opened, and the drawer member (not shown) of the drive device is the left side wall 12B. It approaches the opening 20 from the side and engages with the hole 22 </ b> A of the leader tape 22. At this time, since the leader tape 22 stands by in the state of being close to the left side wall 12B, the drawing member can be reliably engaged with the hole 22A. Thus, when the drawing member is engaged with the hole 22 </ b> A, the drawing member is separated from the opening 20, whereby the leader tape 22 is drawn from the case 12.

  Next, a mold structure of a door member according to an embodiment of the present invention will be described.

  FIG. 3 shows a state in which the mold 46 for molding the door member 30 is clamped. The mold 46 includes a movable mold 48 and a fixed mold 50, and the movable mold 48 is movable in the direction of arrow A. Further, the fixed side mold 50 has a sprue 52 (a portion where the resin flows into the mold by joining with a nozzle of a molding machine) and a runner 54 (a resin between the sprue and the gate port of the molded product). A flow path) is provided. Here, since two door members 30 are formed, the runners 54 are formed so as to branch from the sprue 52 and away from each other.

  On the other hand, the movable mold 48 is provided with a cold slug well 62 on the opposite side of the sprue 52 with the runner 54 interposed therebetween, and the tip of the flowing resin flows between the sprue 52 and the runner 54. Therefore, the tip of the resin is stored in the cold slag well 62 so that the cooled resin does not enter the cavity 64 (the space provided for molding the door member 30). Further, by causing the cold slag well 62 to bite into the movable mold 48, when the movable mold 48 moves, the sprue 52 and the runner 54 are moved together with the movable mold 48 side. be able to.

  Further, the movable die 48 is provided with a protruding pin template (not shown) to which a protruding pin 56 is attached to release the sprue 52 and the runner 54 from the movable die 48, and the door member 30 is movable. Protruding pin mold plates 60 to which protruding pins 58 for releasing from the side mold 48 are attached are respectively provided, and are movable along the arrow A direction with respect to the movable side mold 48. .

  Here, the parting surface PL (of the door member 30) so that the outer surfaces of the main body 40 and the bent portion 42 are inclined with respect to the mold release direction (arrow A direction) of the mold 46 for forming the door member 30. Form). That is, by changing the inclination of the outer surface of the main body portion 40 and the bent portion 42 and the parting surface PL of the inner surface, the outer surface of the main body portion 40 and the bent portion 42 is changed with respect to the releasing direction from the mold 46. Thus, a draft can be provided.

  Thereby, the angle formed by the outer surface of the main body 40 and the outer surface of the bent portion 42 can be made to be a right angle, and the outer surface of the bent portion 42 is not recessed with respect to the left side wall 12B of the case 12. Twelve aesthetics are preserved.

  In addition, the angle formed by the outer surface of the main body 40 and the outer surface of the bent portion 42 is set to a right angle, and the angle formed by the inner surface of the main body 40 and the inner surface of the bent portion 42 is set to a right angle. Since it is not necessary to provide meat stealing for the gradient, the functional design dimensions of the door member 30 can be ensured.

  By the way, by forming the parting surface PL so that the outer surfaces of the main body portion 40 and the bent portion 42 are inclined with respect to the mold release direction (arrow A direction) of the mold 46 for molding the door member 30. The main body 40 and the bent portion 42 substantially obtain a draft angle. In this case, the stopper piece 44 is formed so that the surface facing the bent portion 42 is parallel to the bent portion 42. Therefore, it becomes an undercut portion (a portion protruding or recessed with respect to the mold release direction). For this reason, the protruding pin 56 is used, the shape of the stopper piece 44 is processed into the protruding pin 56, and the stopper piece 44 is formed and released from the protruding pin 56 (described later).

  On the other hand, the outer surfaces of the main body portion 40 and the bent portion 42 of the door member 30 are exposed to the outer appearance of the case 12, and therefore, in the mold 46, the gate port 66 ( In the case of a resin injection port or a molded product, a gate mark 70 (see FIG. 2) must be provided.

  Here, since the recording tape enters and exits the bent portion 42 side, it is not functionally preferable that a gate mark is generated in the bent portion 42. For this reason, it is desirable to provide the gate port 66 in the main body 40. On the other hand, since the gate port 66 is subjected to the largest pressure by molding, residual stress is likely to occur.

  For this reason, if a residual stress is generated around the gate port 66, cracks are generated due to changes over time, and the periphery of the gate port 66 becomes brittle. Therefore, it is necessary to avoid a stressed portion such as the bearing portion 32. is there. Further, in consideration of the orientation (flow) of the resin, it is better to cause the orientation of the resin along the longitudinal direction of the door member 30.

  Therefore, it is desirable to provide a gate port 66 (see FIG. 2, gate mark 70) at the center of the inner surface of the main body 40, whereby the influence of residual stress can be reduced, and the orientation of the resin is the door. Since it will be in the state along the longitudinal direction of the member 30, problems, such as curvature or a twist, will not arise, but dimensional stability can be ensured.

  By the way, when the gate port 66 is provided on the inner surface side of the main body 40, a submarine gate (or tunnel gate) is generally conceivable. In this case, a so-called discard boss (not shown) must be provided. For this reason, after the door member 30 is released, the discarded boss must be gate-cut, which is troublesome.

  Therefore, the gate 68 connecting the runner 54 and the gate port 66 is curved and tapered toward the gate port 66 side so as to be submerged into the inner surface side of the main body portion 40, and directly without using a disposal boss. Resin can be injected into the portion 40. As a result, there is no need to provide a discarded boss, and therefore, there is no need for gate cutting when the door member 30 is released from the mold 46, and workability is improved.

  Next, operation | movement of the metal mold | die of the door member which concerns on one Embodiment of this invention is demonstrated.

  FIG. 3 shows a state in which a mold 46 for molding the door member 30 is clamped and a resin is filled in a cavity (a space formed by the mold 46) 64. In addition, since the name of each part of the door member 30 and the name of the cavity constituted by the mold 46 for molding the door member 30 are the same, hereinafter, in order to avoid confusion, hereinafter, when showing the mold side, after the name It is described as an area.

  As shown in FIG. 4, the movable mold 48 is moved, and the sprue 52, the runner 54, and the door member 30 are moved together with the movable mold 48, and are released from the fixed mold 50. Then, as shown in FIG. 5, the protruding pin 56 moves toward the movable side mold 48, and the sprue 52 and the runner 54 are protruded through the cold slug well 62. Here, since the gate 68 is tapered on the gate port 66 side, the gate 68 is easily broken from the gate port 66 of the door member 30 by the pressing force of the protruding pin 56.

  Next, the gate 68 broken from the gate port 66 must be extracted from the gate region 69. For this reason, the gate region 69 is curved and tapered toward the gate port 66 side.

  Further, as shown in FIGS. 6 and 7, the runner 54 has a length that can be bent and deformed, and the gate 68 is pulled out from the gate region 69 while the runner 54 itself is bent by the pressing force from the protruding pin 56. 68 can be reliably released from the gate region 69. Then, with the gate 68 released from the gate region 69, the sprue 52 and the runner 54 can be released from the movable mold 48 as shown in FIG.

  Next, as shown in FIGS. 9 to 11, the protruding pin template 60 to which the protruding pin 58 protruding the door member 30 is attached moves toward the movable mold 48 side. Here, the protruding pin 58 has a tip protruding and inclined toward the runner 52 side with respect to the moving direction of the pin template 60, and a base protruding in a direction perpendicular to the moving direction of the pin template 60. On the other hand, it can slide.

  By the way, the shape of the stopper piece 44 is processed in the protruding pin 56, and the stopper piece 44 is formed by the protruding pin 56. Further, the protruding pin 56 is arranged only on the stopper piece 44 side of the door member 30 so as to press one end side of the door member 30 in the longitudinal direction.

  Since the center of gravity of the door member 30 is in the vicinity of the central portion in the longitudinal direction, when one end of the door member 30 in the longitudinal direction protrudes and is pressed by the pin 56, a moment around the protruding pin 56 is generated and the stopper piece 44 is moved by its own weight. The tip of the protruding pin 56 comes off.

   Thus, the stopper piece 44 which is an undercut part is formed, and the stopper piece 44 can be easily released. At this time, by taking out the door member 30 by the automatic take-out machine, the door members 30 separated from the movable mold 48 are prevented from contacting each other, and the design surface is not damaged.

  Here, the gate mark 70 (see FIG. 2) is disposed on the inner surface side of the door member 30 without providing a discard boss (in order not to leave the gate mark 70 on the design surface side of the door member 30, In order to provide the gate port 66 on the inner surface side of the door member 30), the gate region 69 is curved and is embedded in the inner surface side of the door member 30. Since the inner diameter dimension in each cross section differs depending on the material, it is not specified.

  In addition, here, a so-called two-stage extrusion method in which the molded product is ejected in two steps is used. However, if the sprue 52, the runner 54, the gate 68 and the door member 30 can be released from the movable mold 48 Of course, the present embodiment is not limited to this embodiment, and may be protruded once.

  Further, in the method of releasing the stopper piece 44, the protruding pin 56 is inclined and is simply released from the protruding pin 56 using the moment acting on the door member 30, but the stopper piece 44 which is an undercut portion is used. However, the present invention is not limited to this as long as it can be released. For example, you may use the core for ribs as described in Unexamined-Japanese-Patent No. 2000-238047 for which this applicant has already applied. Further, a slide core may be used although the cost is slightly increased.

  In the present embodiment, the configuration in which the recording tape cartridge 10 has the leader tape 22 is exemplified. However, the present invention is not limited by the shape of the case 12 and the drawing structure of the magnetic tape T (configuration of the leader member). Absent. Therefore, for example, the recording tape cartridge 10 may have a configuration in which a small cylindrical leader pin is attached to the tip of the magnetic tape T as a leader member.

  In the above embodiment, the magnetic tape T is used as the recording tape. However, the present invention is not limited to this, and the recording tape is a long tape capable of recording information and reproducing the recorded information. Needless to say, the recording tape cartridge according to the present invention is applicable to any recording / reproducing type recording tape.

  Furthermore, the resin molded product of the present invention is not limited to the door member of the recording tape cartridge, and can be applied to any L-shaped resin molded product.

1 is a perspective view showing an external appearance of a recording tape cartridge provided with a door member according to an embodiment of the present invention. It is a perspective view which shows the door member which concerns on embodiment of this invention. It is a plane sectional view explaining operation of a metallic mold which molds a door member concerning an embodiment of the invention. It is a plane sectional view explaining operation of a metallic mold which molds a door member concerning an embodiment of the invention. It is a plane sectional view explaining operation of a metallic mold which molds a door member concerning an embodiment of the invention. It is a plane sectional view explaining operation of a metallic mold which molds a door member concerning an embodiment of the invention. It is a plane sectional view explaining operation of a metallic mold which molds a door member concerning an embodiment of the invention. It is a plane sectional view explaining operation of a metallic mold which molds a door member concerning an embodiment of the invention. It is a plane sectional view explaining operation of a metallic mold which molds a door member concerning an embodiment of the invention. It is a plane sectional view explaining operation of a metallic mold which molds a door member concerning an embodiment of the invention. It is a plane sectional view explaining operation of a metallic mold which molds a door member concerning an embodiment of the invention. It is a plane sectional view which shows the metal mold | die which shape | molds the conventional door member.

Explanation of symbols

10 Recording Tape Cartridge 12 Case 20 Opening 30 Door Member (Resin Molded Product)
40 body part 42 bent part 46 mold 66 gate port 68 gate 69 gate region (gate)
70 Gate trace

Claims (5)

Consists of a body part and a bent part, and is an L-shaped resin molded product in side view,
At least one of the angle formed by the outer surface of the main body portion and the bent portion and the angle formed by the inner surface of the main body portion and the bent portion is formed at a right angle and does not become the design surface of the main body portion and the bent portion. A resin molded product characterized in that a gate mark obtained by injecting resin is provided on the inner surface side or the outer surface side.   The resin molded product according to claim 1, wherein the gate mark is provided at a center of one end of the main body in the longitudinal direction. A mold that is composed of a main body part and a bent part and molds an L-shaped resin molded product in a side view,
A mold, wherein a parting surface is formed so that at least an outer surface or an inner surface of the main body portion and the bent portion is inclined with respect to a mold release direction of the mold.   The gate that connects the runner through which the resin flows and the main body portion and the gate port located on the inner surface side or the outer surface side that does not become the design surface of the bent portion is formed so as to be curved and the gate port side is tapered. The mold according to claim 3. A case in which a reel around which a recording tape is wound is rotatably accommodated;
An opening formed in a corner of the case and capable of pulling out the recording tape;
A recording tape cartridge comprising:
A recording tape cartridge, wherein the door member for opening and closing the opening is the resin molded product according to claim 1.

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