JP4383203B2 - Leader tape, leader tape cutting machine, method for cutting both ends of a leader tape raw material, and magnetic tape cartridge - Google Patents

Description

  The present invention relates to a leader tape, a leader tape cutting machine, a method for cutting both ends of a leader tape raw material, and a magnetic tape cartridge, and more particularly, to a magnetic tape wound around a reel in a single tape cartridge. In addition, the present invention relates to processing of both ends of a leader tape for joining a leader tape to a leader pin by ultrasonic welding and a cutting method for obtaining the same.

  Conventionally, as a magnetic tape cartridge used as a recording medium of a computer or the like, a magnetic tape cartridge in which a magnetic tape is wound around one reel and the reel is rotatably accommodated inside a cartridge case composed of an upper cartridge and a lower cartridge. There is.

  In use, this magnetic tape cartridge is used by pulling out the magnetic tape from the opening of the cartridge case. When not in use, the magnetic tape is completely wound on the reel, and the leader tape joined to one end of the magnetic tape (the engaging means provided in the device such as a computer is connected to the magnetic tape). Engaging means for introducing the tape into the tape path) is locked to the end surface portion of the cartridge case, and the reel is locked by a locking means such as a reel lock so that the reel does not rotate unexpectedly. The opening is closed by a lid that can be freely opened and closed.

FIG. 7 is a conceptual perspective view of a state in which one end of the leader tape is joined to the leader pin and the other end is joined to the magnetic tape.
In the figure, 140 is a leader tape made of polyethylene terephthalate (PET), 140a is a cutting end (first cutting portion) that has been cut, and 140b is tightly wound around a leader pin 21a (also shown in FIG. 1). A winding part (non-cutting part), 140c is a central part (non-cutting part), and 140d is a rear end part (second cutting part) subjected to cutting.
As shown in the figure, the leader pin 21a is tightly wound in the vicinity (140b) of the leader tape 140 in the vicinity of the tip, and the tip (140a) is ultrasonically welded to the leader tape (140c) of the non-winding part. The leader tape 140 has a thickness t2 in the original state before being subjected to cutting, but the welding side of the distal end portion 40a is cut to ensure bonding by ultrasonic welding. Furthermore, it is tapered so as to taper toward the tip. When the thickness of the leader tape tip 140a is t1, and the thickness of the leader tape 140c at the non-winding portion is t2, t1 <t2.

  On the other hand, the rear end portion 140 d of the leader tape 140 is joined to the magnetic tape 60 by the splicing tape 64. The leader tape 140 has a thickness t2 in the original state before cutting, but in order to ensure the joining of the splicing tape 64 to the magnetic tape 60, the magnetic tape 60 at the rear end portion 140d of the leader tape 140 is secured. The taper processing is performed so that the thickness of the taper gradually decreases to t3. That is, t3 <t2. By such a taper portion, there is no step at the joint portion between the leader tape 140d and the magnetic tape 60, so that stable running is possible.

Conventionally, a mechanical cutting method has been proposed in order to taper both ends of a PET raw material having a thickness t2. As described in Patent Document 1, the mechanical cutting method is such that the tip of the leader tape is mechanically cut into a tapered shape by rotating a cylindrical end mill with a certain angle with respect to the rotation axis of the roller. To be processed.
JP 2000-111591 A

FIG. 8 shows an end mill that performs cutting at the front end and cutting at the rear end by a conventional method. In the figure, 140 is a raw fabric, 140a is a first cutting portion indicated by hatching (leader portion of the leader tape), 140d is a second cutting portion indicated by hatching (rear end portion of the leader tape), 142 is a metal roll, 143, Reference numeral 143 denotes a cylindrical end mill. The end mill 143 is a continuous blade. End mill 143 is may be placed in the same position in the transfer direction of the raw sheet 140, but it may also be placed is divided into upstream and downstream of the transfer direction (Here, for easy understanding, the same position This is shown in the example shown in FIG. Further, the length of the original fabric 140 in the width direction is the same as or slightly longer than the leading end portion 140a to the trailing end portion 140d of the leader tape in FIG.

  As shown in the figure, the rotation axis of the end mill 143 is not parallel to the rotation axis of the metal roll 142 but has an angle, so that the portion to be cut 140a indicated by hatching is tapered by the rotation of the cylindrical end mill 143. To be mechanically cut. By appropriately setting this angle and moving the end mill 143 in the original fabric direction, the cut portions 140a and 140b of the original fabric 140 can be tapered by a desired amount. In this way, the original fabric 140 on which the parts to be cut 140a and 140b are formed is punched to the full width direction of the original fabric 140 as indicated by a dotted line with a press machine to obtain the leader tape 40 (see FIG. 7). The punched leader tape is wound with a leader pin at its winding part 140b and joined with the opposing leader tape by ultrasonic welding at its leading part 140a to firmly fix the leader pin, and spliced at its rear end part 140d. The tape 64 is joined to the magnetic tape.

  In the conventional leader tape, since the same end mills 143 and 143 are used at the leading end and the trailing end of the leader tape in this way, naturally, the same surface roughness is formed and used. This is because there is no need to replace one of the end mills 143 and 143 with another end mill.

  However, when the present applicant observed the joining state of the leading end of the leader tape and the joining state of the trailing end, it was found that each had optimum surface roughness and the values were not the same. As a result of searching for the reason, the former is a method in which the leader tapes are joined to each other by ultrasonic welding, and the latter is joined by splicing, and the joining method is different by ultrasonic welding and splicing. It has been found that there should be an optimum surface roughness range for each.

The present invention solves these problems, and provides a leader tape cutting machine that finds an optimum surface roughness range for ultrasonic welding and splice bonding and can perform cutting to such an appropriate surface roughness. The purpose is to do.

In order to solve the above-mentioned problems, the invention of the leader tape according to claim 1 is a leader tape in which the leading ends are joined to each other by ultrasonic welding and the trailing end is joined to the leading end of the magnetic tape by a splice. The both ends are each mechanically cut, and the surface roughness of the end portion on the ultrasonic welding side is larger than the surface roughness of the end portion on the splice side .

According to a second aspect of the present invention, in the leader tape of the first aspect, the surface roughness RZ (RZ is RZ-JIS standard) of the end portion on the splice side is 2 μm <RZ ≦ 5 μm .

  The invention according to claim 3 is the leader tape according to claim 1 or 2, wherein the both ends are each cut into a taper shape.

The invention of the leader tape cutting machine according to claim 4 is characterized in that both ends of the raw material of the leader tape are joined with each other by ultrasonic welding and the rear end is joined to the front end of the magnetic tape by a splice. Each of the first end mill and the second end mill, wherein the first end mill cuts the end portion on the ultrasonic welding side, and the second end mill removes the end portion on the splice side. Cutting is performed, and the cutting roughness by the first end mill is larger than the cutting roughness by the second end mill .

According to a fifth aspect of the present invention, in the leader tape cutting machine according to the fourth aspect, the cutting roughness RZ (RZ is RZ-JIS standard) by the second end mill is 2 μm <RZ ≦ 5 μm .

A magnetic tape cartridge according to a sixth aspect of the present invention is the magnetic tape cartridge according to the first or second aspect, wherein the leading end is wound around a winding member and joined by ultrasonic welding. And a magnetic tape wound around a magnetic tape reel and joined to the leader tape by a splice.

According to the leader tape of the first aspect, since the surface roughness of the end portion on the ultrasonic welding side is larger than the surface roughness of the end portion on the splice side , each can take an optimum value.
According to the invention described in claim 2, since the surface roughness RZ of the end portion on the splice side is 2 μm <RZ ≦ 5 μm , the optimum value can be easily determined.
According to the third aspect of the present invention, since both ends are each cut into a taper shape, the joining portion becomes smooth without a step and a strong joining is achieved.
According to the invention of the cutting machine described in claim 4, since the cutting roughness by the first end mill is larger than the cutting roughness by the second end mill , the end portion on the ultrasonic welding side can be obtained by using this cutting machine. It is possible to manufacture a leader tape whose surface roughness is larger than the surface roughness of the end portion on the splice side .

According to the invention described in claim 5, the surface roughness RZ by the cutting machine can be easily set to the optimum value.
According to the sixth aspect of the present invention, a magnetic tape cartridge having a strong bonding force between the joint portion between the leader pin and the leader tape and the joint portion between the magnetic tape and the leader tape can be obtained.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.
FIG. 1 is an exploded perspective view of a magnetic tape cartridge according to an embodiment of the present invention. In the magnetic tape cartridge 1 shown in FIG. 1, a magnetic tape 20 is wound around one reel 3 formed by, for example, ultrasonic bonding of an upper reel 4 and a lower reel 5, and this reel 3 is used as an upper cartridge 2a and a lower cartridge 2b. Are rotatably housed in a cartridge case fastened by screws 19.

  In the reel 3, the upper reel 4 has an upper flange 4a, and a concave portion is provided at the center thereof. And the gear part 4b is formed in the outer periphery of this upper flange 4a. A ring-shaped bearing 6 is press-fitted and fixed in a circular rib formed in the recess, and a spring plug 7 is press-fitted and fixed in a hole in the center of the bearing. A reel spring 8 is attached to the spring plug 7 to press the reel 3 downward and hold it rotatably.

  The reel 3 is locked so as not to rotate unexpectedly by a reel lock 32 appropriately biased by a reel lock spring 12 when the cartridge is not used. The tip of the magnetic tape 20 is joined to the leader tape 21 by a splice, and the leader tape 21 is locked to the tip of the leader tape 21 by ultrasonic welding. When the magnetic tape cartridge 1 is not in use, the magnetic tape 20 is completely wound around the reel 3, and the leader pin 21a is locked to the front end portion of the hook 18 incorporated near the side of the cartridge. Has been.

  A lid 30 that can be opened and closed in the cartridge plane direction is attached to the opening 26 through which the magnetic tape 20 is drawn out by being appropriately urged by a lid spring 15 for urging the lid. Further, the leader tape 21 that engages with the engaging means (for example, leader pin) for introducing the magnetic tape 20 into the tape path of the apparatus has different roughness at the front end and the rear end defined by the present invention. Thus, the joints between the leader pin 21a and the magnetic tape 20 can be joined more strongly.

Next, an example of a method for producing the leader tape will be described with reference to FIG.
As shown in FIG. 2, a PET original fabric 40 having a thickness larger than that of a magnetic tape is wound around a supply roll 41, and the original fabric 40 supplied from the supply roll 41 is first a first metal roll 42. And the first end mill 43, the second metal roll 45 and the second end mill 46, and finally the take-up roll 48.
For the material to be cut, it is better not to cut the dimension in the longitudinal direction accurately, but to make a slightly larger cutting part in the longitudinal direction and adjust the dimensions by press cutting at the final press stage. .

  Also, instead of the machining step as shown in FIG. 2, after the portion to be cut is tapered by the second end mill 46, a cleaning roll is provided to clean the surface of the original fabric, and press punching is performed immediately thereafter. Can be a continuous process.

FIG. 3 is a view showing an end mill according to the present invention for cutting each of the leading end portion and the trailing end portion of the leader tape.
In the figure, reference numeral 40 denotes an original fabric, 40a denotes a first cutting portion (leading end portion of the leader tape) indicated by hatching, 40b denotes a winding portion wound around the leader pin, 40c denotes a central portion, and 40d denotes a second cutting portion indicated by hatching. (Rear end portion of the leader tape), 42 is a metal roll, 143 is a conventionally used continuous blade end mill, and 43 is a two blade end mill employed in the present invention.
The length in the width direction of the original fabric 40 is the same as or slightly longer than the length from the leading end 40a to the trailing end 40d of the leader tape.

  As shown in the figure, the rotation axes of the end mills 43 and 143 are not parallel to the rotation axis of the metal roll 42 but have an angle, so that the parts to be cut indicated by hatching by the rotation of the cylindrical end mills 43 and 143 are shown. 40a and 40b are mechanically cut into a tapered shape. By appropriately setting this angle and moving the end mills 43 and 143 in the original fabric direction, the cut portions 40a and 40b of the original fabric 40 can be tapered by a desired amount. In this way, the raw fabric 40 on which the cut portions 40a and 40b are formed is punched to the full width of the original fabric 40 as indicated by a dotted line with a press machine to obtain the leader tape 40. The punched leader tape is wound with a leader pin at its winding part 40b and joined with the opposite leader tape by ultrasonic welding at its leading part 40a to firmly fix the leader pin, and then spliced at its rear end part 40d. The tape 64 is joined to the magnetic tape.

The raw 40 is transported 1.0m~2.0m / min neighborhood, and by rotating in 10k~20krpm end mill results of an experiment, the cutting surface roughness RZ (RZ by end mill 143 of the continuous blade RZ-JIS standard) was 5 to 15 μm .
On the other hand, in the case of the end mill 43 of two blades surface roughness RZ was 2~5μ m. Even with the same two-blade end mill 43, the surface roughness RZ is different from 2 μm because the feed rate of the raw fabric 40 is about half that of 5 μm, or the rotation speed of the end mill is about doubled. By making it.

The leader tape according to the present invention is thus formed with different surface roughnesses by using different types of end mills 43 and 143 at the leading end and the trailing end of the leader tape. That is, the end mill 143 can have a surface roughness RZ of 15 to 5 μm, and the end mill 43 can have a surface roughness RZ of 5 μm or less.
In the case of the ultrasonic welding side, it was found that the surface roughness RZ of the end portion should be 5 μm <RZ ≦ 10 μm, and the surface roughness RZ of the end portion on the splice side should be 5 μm or less.

Therefore, the reason why it is preferable that the leading end of the leader tape is 5 μm <RZ ≦ 10 μm and the trailing end is 2 μm <RZ ≦ 5 μm will be described.
4A and 4B are cross-sectional views of the leader tape. FIG. 4A is a cross-sectional view of the rear end portion of the leader tape, and FIG. 4B is a cross-sectional view of the front end portion. Further, in (a), (b) if the surface roughness RZ of the rear end portion of the leader tape is 2.mu. m, (ii) if the surface roughness RZ is 5 [mu] m, (iii) the surface roughness RZ Each shows a case of 10 μm .

That's the surface roughness RZ is 2.mu. m in (a), the surface is lacking in tip resistance, be bonded over at the splice 64 thereon, physical engagement of the leader tape 40d and splices 64 (i.e. The leader tape 40 is not stabbed into the splice 64), and since the unevenness of the leader tape 40 is low, the contact area and contact resistance of each other are small, and strong bonding strength and durability cannot be obtained. There was found.

On the other hand, when the surface roughness RZ of (b) is a leader tape 40 of 5 [mu] m, since the surface irregularities are pointed higher tip, when joined over at the splice 64 thereon, first leader tape 40 tip The tip part of the tape is pierced into the splice 64 to obtain the strength by mechanical coupling with each other, and since the unevenness of the leader tape 40 is deep, the mutual contact area and contact resistance are increased, and strong bonding strength and durability are obtained. Turned out to be.

However, as shown in (c), when the surface roughness RZ of the leader tape 40 of the 10 [mu] m, the tip of the tip of the leader tape 40 to obtain a greater strength by mutual mechanical coupling pierced into the splice 64 However, conversely, when the splice is joined and pressed with a splice, the protrusion K protrudes outward from the end of the leader tape, which is a disadvantage that must be avoided.
Therefore, the overall result shows that the surface roughness RZ of (b) is preferably 2 μm <RZ ≦ 5 μm .

FIG. 4B is a cross-sectional view of the tip of the leader tape.
On the other hand, the tip 40a of the leader tape is not spliced but joined to the leader tape 40c by ultrasonic welding. In this case, the surface roughness RZ of the end portion is preferably 5 μm <RZ ≦ 10 μm. If the surface roughness RZ is within this range, the surface irregularity is high and the tip is sharp, and the tip tape 40s is pierced into the leader tape 40c by being covered and pressed by the leader tape. First, strength is obtained by mutual mechanical coupling, and then the tip portion 40s pierced by ultrasonic welding is melted in the inside so that it is difficult to escape, so it is assumed that strong joint strength and durability will be obtained. It is. In addition, it was confirmed that the fluff standing when pressed melts by ultrasonic welding and does not remain as fluff.
Thus, it was found that a surface roughness RZ of 5 μm <RZ ≦ 10 μm formed by the continuous blade end mill 143 is not suitable for splice bonding but is suitable for ultrasonic welding.

  Therefore, according to the present invention, the surface roughness RZ of the tip of the leader tape 40 is 10 μm to 5 μm, which can be achieved by using a continuous blade end mill. Further, the surface roughness RZ of the rear end of the leader tape 40 is 5 μm or less. This can be achieved by using an end mill having 2 to 4 blades instead of a continuous blade. In this case, it was obtained by transferring the leader tape at about 1.5 m / min and rotating the end mill at about 15000 rpm.

FIG. 5 is a conceptual perspective view showing a state in which the leader tape cut in this manner is joined to the leader pin at the front end and to the magnetic tape at the rear end.
In the drawing, 40 is a leader tape made of polyethylene terephthalate (PET), 40a is a tip portion (first cutting portion) subjected to cutting (5 μm <RZ ≦ 10 μm), and 40b is a leader pin 21a (also shown in FIG. 1). Winding portion (non-cutting portion) tightly wound around (with), 40c is a central portion (non-cutting portion), and 40d is a rear end portion (second cutting portion) subjected to cutting (5 μm or less).

As shown in the drawing, the leader pin 21a is tightly wound in the vicinity (40b) of the leader tape 40, and the tip (40a) is ultrasonically welded to the non-winding leader tape (40c). Furthermore, it is tapered so as to taper toward the tip. If the thickness of the leader tape tip 40a is t1, and the thickness of the unwrapped leader tape 40c is t2, then t1 <t2.
As described above, since the distal end portion 40a is cut so that 5 μm <RZ ≦ 10 μm, strong bonding by ultrasonic waves can be obtained.

On the other hand, the splicing tape 64 is joined to the rear end portion 40 d of the leader tape 40 on the surface roughness of 5 μm or less, thereby joining to the magnetic tape 60. The leader tape 62 has a thickness t2 in the original state before being subjected to the cutting process, but in order to ensure the joining of the splicing tape 64 to the magnetic tape 60, the magnetic tape 60 at the rear end portion 40d of the leader tape 40 is secured. The taper processing is performed so that the thickness of the taper gradually decreases to t3. That is, t3 <t2. With such a tapered portion, there is no step at the joint between the leader tape 62 and the magnetic tape 60, so that stable running is possible.
In addition, since the surface is subjected to cutting so as to be 5 μm or less, strong joining with the splicing tape 64 is obtained.

FIG. 6 is a diagram showing the processing results obtained with the two-blade and four-blade employed in the present invention. The two-blade end mill 43 of (1) and the four-blade end mill 43 ′ of (2). The cutting edge shown at 143 in FIG. 3 is different from the spiral one. By using such an end mill, a leader tape composed of irregularities of the cut portions at regular intervals can be obtained. The concave / convex spacing (pitch) of the cutting portion cut by the four-blade end mill 43 ′ is L / 2, and is naturally half the concave / convex spacing (pitch) L of the cutting portion cut by the two-blade end mill 43. The unevenness spacing of the cutting part is determined by the relative speed between the feed speed of the original fabric 40 and the rotation speed of the end mill 43.
Here, an end mill having a number of blades of 2 to 4 is used, the raw fabric (leader tape) 40 is transported in the vicinity of 1.0 m to 2.0 m / min, and the end mill is rotated in the vicinity of 10 to 20 krpm. I try to let them. In this way, the cross-section of both the two blades and the four blades was within the range of the surface roughness RZ as shown by hatching at the bottom of the figure of 5 μm or less.

  In addition, as a means for performing taper processing by cutting, a method has been shown so far in which a substantially cylindrical end mill has a predetermined angle with respect to a rotation shaft of a roller that supports the original fabric. The end mill itself may be tapered and a method of cutting the raw material at the tapered portion may be employed.

  As a result of such taper processing, the thickness of the tip of the leader tape gradually decreases, but generally the thickness of the leader tape is about 100 to 200 μm, which is considerably thicker than the thickness of the magnetic tape. However, the thickness is gradually reduced only to 2 to 10 times the thickness of the magnetic tape, but if it has converged to such a thickness difference, a desired effect can be obtained.

  Furthermore, the present invention is not limited to the above-described embodiments, and appropriate modifications and improvements can be made based on the spirit of the present invention. For example, the shape of the end mill that cuts the taper portion is not limited to the above-described shape, and it is also possible to provide a step portion at the tip of the end mill so that the tapered portion is inclined.

  As described above, according to the present invention, there is provided a leader tape cutting machine that can find the optimum surface roughness range for ultrasonic welding and splice bonding, and can perform cutting to such an appropriate surface roughness. I was able to get it.

1 is an exploded perspective view of a magnetic tape cartridge according to the present invention. It is the schematic for demonstrating the manufacturing method of a leader tape. It is a figure which shows the end mill which concerns on this invention for each cutting of the front-end | tip part and rear-end part of a leader tape. It is sectional drawing of each front-end | tip and rear end of the leader tape which concerns on this invention, (a) is sectional drawing of the rear-end part of a leader tape. It is a conceptual perspective view which shows the state which the leader tape which concerns on the cutting process of this invention was joined to the leader pin at the front-end | tip, and the magnetic tape at the rear end. It is a figure which shows the processing result obtained by the 2 blade and 4 blades employ | adopted by this invention, (1) is a 2 blade end mill, (2) is a 4 blade end mill. It is a conceptual perspective view which shows the state which the leader tape which concerns on the conventional cutting process was joined to the leader pin at the front-end | tip, and the magnetic tape at the rear end. The end mill which performs cutting of a front-end | tip part and cutting of a rear-end part by the conventional method is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Magnetic tape cartridge 2 Cartridge 2a Upper cartridge 2b Cartridge 3 Reel 4 Upper reel 4a Upper flange 4b Gear part 5 Lower reel 6 Bearing 7 Spring plug 8 Reel spring 12 Reel lock spring 15 Lid spring 18 Hook 19 Screw 20 Magnetic tape 21 Leader tape 21a Leader pin 26 Opening portion 30 Lid 32 Reel lock 40 Raw material 40a made of PET Tip end portion 40b subjected to cutting (5 μm <RZ ≦ 10 μm) Leader pin winding portion 40c Central portion (non-cutting portion)
40d Rear end portion 40s subjected to cutting (2 μm ≦ RZ ≦ 5 μm) Pointed end portion 41 Feeding roll 42 First metal roll 43 First end mill 45 Second metal roll 46 Second end mill 48 Winding roll

Claims (6)

Leader tape for joining the front ends to each other by ultrasonic welding, and joining the rear end to the front end of the magnetic tape with a splice,
The leader tape, wherein both ends are mechanically machined, and the surface roughness of the end portion on the ultrasonic welding side is larger than the surface roughness of the end portion on the splice side . 2. The leader tape according to claim 1, wherein a surface roughness RZ (RZ is RZ-JIS standard) of an end portion on the splice side is 2 μm <RZ ≦ 5 μm .   The leader tape according to claim 1 or 2, wherein the both ends are cut into a tapered shape. Leaders where the leading ends are joined to each other by ultrasonic welding and the ends of the leading end of the leader tape are joined to each other by a splice with the leading end butting the leading end of the magnetic tape by a first end mill and a second end mill, respectively. A tape cutting machine,
The first end mill cuts the end portion on the ultrasonic welding side, the second end mill cuts the end portion on the splice side, and the cutting roughness by the first end mill is the cutting roughness by the second end mill. Leader tape cutter characterized by being larger than the above . 5. The leader tape cutter according to claim 4, wherein a cutting roughness RZ (RZ is RZ-JIS standard) by the second end mill is 2 μm <RZ ≦ 5 μm .   The leader tape according to claim 1 or 2, wherein the leading end is wound around a drawing member and joined by ultrasonic welding, a single magnetic tape reel, one is wound around the single magnetic tape reel, and the other is the leader tape And a magnetic tape joined by a splice.

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