JPH0742634Y2 - Slitter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a slitter used, for example, for manufacturing a magnetic tape, and more particularly to improvement of a blade thereof.

[Conventional technology]

In recent years, cementation of various blades has been promoted, but slitters for magnetic tape production have also been cemented. This type of slitter includes a plurality of thin disk-shaped upper blades arranged at a predetermined interval, and a plurality of thick disk-shaped lower blades each of which has a tip end contacting one side surface. The wide magnetic film is cut into a predetermined width by contact between the upper blade and the lower blade.

The lower blade has a role of a cutting blade, a role of a spacer for controlling the tape width, and a role of stably running the tape. When the lower blade of such a slitter is made of cemented carbide, there are various problems. That is, the specific gravity of special steel, which is a conventional blade material, is 7.8 to 8.6, whereas that of cemented carbide (WC) is about 15. For this reason, if only the material is changed to cemented carbide with the conventional shape, not only the cost will increase, but also the weight will double and the mechanical structural strength of the slitter, such as the diameter of the blade mounting shaft, the wall thickness of the bearing of this shaft, It is necessary to increase not only the power source for driving the blade mounting shaft but also the slitter body becomes large.

Therefore, conventionally, a composite blade as disclosed in Japanese Patent Laid-Open No. 54-84670 has been proposed. In other words, it is a lower blade in which only the cutting edge portion of the lower blade is formed of cemented carbide and the portion other than the cutting edge portion, that is, the portion which becomes the spacer is formed of ceramics or a special cermet.

[Problems to be solved by the device]

However, the lower blade disclosed by the present applicant in JP-A-54-84670 is one in which the cutting edge portion is formed of cemented carbide and the spacer portion other than the cutting edge portion is formed of ceramics, The original purpose of providing a lower blade having no problem in weight, grindability, physical properties for an object to be cut, and the like has been achieved. On the other hand, however, the quality of the magnetic tape, which is the object to be cut, has improved dramatically. For this reason, high quality is required even for the lower blade with which the magnetic tape is in direct contact, and in particular, submicron finishing accuracy is required for the surface roughness and steps of the outer peripheral surface of the lower blade. . Therefore, it is required to be finer than the grain size of the crystal particles constituting the ceramics, and the ceramics sintered with the raw material powder having the submicron grain size has been demanded. As a result, there has been a problem that ceramics are more expensive than cemented carbide for the cutting edge.

Next, it has been proposed that the cutting edge portion is formed of ultra-high alloy, and the spacer portion other than the cutting edge portion is formed of a special cermet.
With a cermet of 0 mm or more, there is a risk of cracking during sintering, and sinter molding is difficult. Therefore, the spacer of the cermet is also more expensive than the ultra-high alloy of the cutting edge portion.

Further, when a cermet is ground with a cemented carbide grindstone, the grindstone does not fit and the cutting is bad, and if grinding the cemented carbide and the cermet at the same time, it takes a considerable amount of time for finish grinding, which is uneconomical.

The object of the present invention is to improve the above-mentioned drawbacks of the prior art, and
Compared with the lower blade made of cemented carbide as a whole, the weight can be reduced, the cost can be reduced, the grindability and wear resistance are excellent, and there is almost no step at the boundary between the cutting edge and the spacer portion. To provide a slitter.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention has a first blade supported by a first rotating shaft and having a thin-shaped cutting blade, and a cutting blade contacting the cutting blade of the first cutting blade. A slitter having a blade portion, a first blade having a relief groove for the cutting blade, and a second blade supported by a second rotating shaft, comprising a cutting blade portion of the second blade. It is characterized in that it is formed of cemented carbide and that parts other than the cutting edge portion are formed of powder sintered alloy.

[Action]

According to the above configuration, the cutting edge portion is formed of cemented carbide, and the portion other than the cutting edge portion is formed of the powder sintered alloy, so that the cutting edge portion and the portion other than the cutting edge portion have grindability and wear resistance. The sexes can be almost the same. As a result, when the cutting edge grinding is performed, the cutting blade portion and the portion other than the cutting blade portion are ground in the same manner,
Also, when actually cutting an object to be cut such as magnetic tape, the cutting edge and parts other than the cutting edge wear in the same way, and in both cases there is no step at the boundary between them. .

Moreover, the specific gravity of the powder sintered alloy is 7.8 to 8.6, and the specific gravity of the cemented carbide is about 15. Therefore, the weight of the second cutting tool can be reduced and the use of expensive cemented carbide can be eliminated. Since it can be limited to only the blade portion, the cost can be reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, the first rotary shaft 1 located above is rotatably supported at both ends by bearings 2 and 3, and a flange portion is provided between these bearings 2 and 3 in the vicinity of one bearing 2. Have four. A cylindrical collar 5 is fitted on the first rotary shaft 1 from the right side in the drawing, and the collar 5 is in contact with the flange portion 4. On the right side of the collar 5, a plurality of sets of cylindrical upper blade holders 6 and upper blades 7 as a first blade having a thin disk-shaped cutting blade are sequentially fitted, and further a collar 8 is fitted. The collars 5 and 8 on both ends, and the upper blade holder 6 and the upper blade 7 are tightened by the upper blade push nut 9 screwed into the first rotary shaft 1 and
It is fixed to the rotary shaft 1.

In the protruding portion from the bearing 3 on the right side of the first rotating shaft 1,
The gear 10 is fixed, and the gear 12 fixed to the right end of the second rotating shaft 11 located below is meshed with the gear 10. Slightly inward from both ends of the second rotary shaft 11,
The second rotary shaft 11 is rotatably supported by bearings 13 and 14, and the protrusion of the second rotary shaft 11 from the bearing 13 is connected to a drive source (not shown). As a result, the second rotating shaft 11 is rotated along with the rotation of the drive source.

In addition, between the bearings 13 and 14 of the second rotary shaft 11, the bearing 1
A flange portion 17 is provided in the vicinity of 3. A collar 18 fitted to the rotary shaft 11 is brought into contact with the flange portion 17 from the right side of the second rotary shaft 11, and the collar 18
A plurality of lower blades 19 as second blades are sequentially fitted on the right side of the, and collars 20 are further fitted, and collars at both ends of these collars are fitted.
The lower blades 18, 20 and the lower blade 19 are fixed to the second rotary shaft 11 by being tightened by a lower blade push nut 21 screwed into the second rotary shaft 11.

At this time, the cutting edge interval of each lower blade 19 is a dimension for cutting an object to be cut such as a magnetic film into a predetermined width, for example, 1/4 inch in the case of a magnetic tape for open reel, 1/2 in the case of a video tape.
It is set to inches, etc.

The lower blade 19, as shown in FIG.
The blade is divided into two parts on a plane orthogonal to the second rotation axis 13, and the portion contacting the upper blade 7 is a thin disk-shaped cutting blade portion 22 and the portion other than the cutting blade portion 22 is a spacer portion 23. ing.
The cutting edge portion 22 is formed of a cemented carbide, the spacer portion 23 is formed of a powder sintered alloy, and a small diameter portion forming an escape groove 24 for escaping the outer peripheral portion of the upper blade 7 is formed on one side surface. Have In the powder sintered alloy forming the spacer portion 23, C is 0.8 to 2.7 wt%, W is 1.5 to 15 wt%, and Mo is
1.3-9.5wt%, V 1-9.8wt%, Co 0 or 5-12w
t% and Cr are 3.7 to 5.3 wt%.

Incidentally, as described above, the cutting blade portion 22 made of cemented carbide and the lower blade made up of the spacer portion 23 made of powder sintered alloy.
A plurality of 19 are push nuts 21 stacked on the second rotating shaft 11.
After being fixed by, the outer periphery is ground by a cylindrical grinding machine, and the cutting edge portion 22 is ground. At this time, the powder-sintered alloy has substantially the same grinding characteristics as the cemented carbide and can be ground easily.

In the above configuration, in order to cut an object to be cut such as a magnetic film to manufacture a magnetic tape or the like, the second rotating shaft 11 is rotated by a drive source (not shown) and the gear 1
The first rotary shaft 1 is rotated via 2,10. When the object to be cut is inserted between the upper blade 7 and the lower blade 19 in this state, the object to be cut is cut into a predetermined width by the cutting edge portion 22 of the upper blade 7 and the lower blade 19. In this cutting, the outer periphery of the lower blade 19 is cylindrically ground as described above, and the wear resistance of the cutting edge portion 22 and the spacer portion 23 that configure the lower blade 19 are almost the same, so the cutting edge portion 22 Similarly, the spacer portion 23 is not worn and a step is not formed at the boundary between the two, and the object to be cut is not scratched.

Further, although the specific gravity of the powder sintered alloy is about 7.8 to 8 and the specific gravity of the cemented carbide is about 15, the cutting edge portion 22 made of the cemented carbide is relatively thin (for example, 5 mm), The space 22 made of powdered sintered alloy varies depending on the slit width, but this
In the case of 1/2 inch, since the thickness becomes thicker than the cutting edge portion 22 (7.7 mm), the weight of the lower blade 19 as a whole can be largely reduced as compared with the lower blade of cemented carbide. Therefore, high-speed cutting is possible without increasing the mechanical rigidity of the second rotating shaft 11 and the required power of the drive source.

Further, the cost of the lower blade 19 can be significantly reduced by reducing the expensive cemented carbide portion, and as a result, it is possible to save valuable resources such as tungsten having a small endowment amount.

The cutting edge portion 22 and the spacer portion 23 that form the lower blade 19 may be bonded or may not be bonded. Since there is no practical problem even if they are not bonded, it is more cost effective not to bond them.

Next, FIG. 5 shows another embodiment of the lower blade 19 used in the present invention, in which the cutting edge portion 22B is provided in a ring shape on the outer peripheral portion of one side surface of the lower blade 19 and most of the remaining portion. Is a spacer portion 23B. At this time, the cutting edge portion 22B is made of cemented carbide, and the spacer portion 23B is made of powder sintered alloy. Even with this configuration, the same effect as described above can be obtained. Further, according to this embodiment, the cemented carbide portion can be minimized.

Next, the lower blade shown in FIG. 5 was prototyped and its weight, thickness, surface roughness and cross-sectional shape were measured. The results will be described.

The prototype lower blade (hereinafter referred to as the prototype) has an outer diameter of 134 mm × an inner diameter of 100 mm × a thickness of 12.643 mm, and the cutting edge portion was bonded to the spacer portion with an adhesive. A thermosetting epoxy resin was used as the adhesive.

The measurement results are shown below.

(1) The weight of one prototype was 600 g on average.
If all lower blades of the same size are made of cemented carbide, the average weight per piece is 1050 g, so the prototype reduced the weight by about 40%.

(2) Thickness The thickness of the prototype was measured using an electric micrometer (tesatronics TTD20). As shown in FIG. 6, there were four measurement points along the circumferential direction of the lower blade, and the measurement was performed at the cutting edge portion (point A) and the spacer portion (point B) at each location.

The measurement results are shown in Table 1. In the table, the measurement results are shown by the difference between the measured values and the designed values (12.643 mm).
Further, R indicates a range of measured values, and indicates an average value of the measured values.

From Table 1, it was found that the average step between points A and B was about 0.3 μm.

(3) Surface Roughness Surface roughness was measured for the cutting edge part and the spacer part on the lap surface of the prototype, and the cutting edge part and the spacer part on the outer peripheral surface (for the positions of the lap surface and the outer peripheral surface, see No. 6). (See FIG. (A)). The measurement results are shown in FIGS. 7 to 14. Here, FIGS. 7 and 11 show the surface roughness of the cutting edge portion on the lapping surface, FIGS. 8 and 12 show the surface roughness of the spacer portion on the lapping surface, and FIGS. The drawings show the surface roughness of the cutting edge portion on the outer peripheral surface, and FIGS. 10 and 14 show the surface roughness of the spacer portion on the outer peripheral surface. The above measurement results are summarized in Table 2.

From Table 2, it was found that the surface roughness of the cutting edge portion was good on the lap surface and the surface roughness of the spacer portion was good on the outer peripheral surface (however, the difference was slight).

(4) Cross-sectional shape The cross-sectional shape of the prototype lap surface and outer peripheral surface was measured (room temperature 22c at the time of measurement). The measurement results are shown in FIGS. 15 to 22. Here, FIGS. 15 to 18 show the cross-sectional shape of the lap surface, and FIGS. 19 to 22 show the cross-sectional shape of the outer peripheral surface.

From these figures, it can be seen that there is almost no step at the boundary between the cemented carbide and the powder sintered alloy.

[Effect of device]

As described above, according to the present invention, since the parts other than the cutting edge part of the second cutting tool are made of the powder sintered alloy, the weight of the slitter is largely reduced as compared with the lower cutting edge of the cemented carbide. In addition, the slitter cost can be reduced.

Further, since the powder grindability of the powder sintered alloy is almost the same as that of the cemented carbide, the cutting edge portion and the portion other than the cutting edge portion are ground in the same manner during the cutting of the cutting edge, and a step is formed at the boundary between the two Of course, it is also possible to shorten the grinding time.

Furthermore, the wear resistance of the powder sintered alloy in contact running of the magnetic tape is almost the same as that of cemented carbide, so even if it is used as the lower blade of the slitter for a long period of time, the parts other than the cutting edge are the same. As described above, it is possible to prevent scratches on an object to be cut, such as a magnetic tape, without causing a step difference at the boundary between the two.

[Brief description of drawings]

1 to 4 show one embodiment of a slitter according to the present invention. FIG. 1 is an overall schematic configuration diagram, FIG. 2 is an enlarged sectional view of a lower blade portion, and FIG. 3 is an upper blade and FIG. 4 is a perspective view of the lower blade, FIG. 4 is a sectional view of the lower blade, FIG. 5 is a sectional view showing another embodiment of the lower blade, and FIG. 6 is a sectional view showing a thickness measurement point and a plan view. FIG. 14 to FIG. 14 are diagrams showing the measurement results of the surface roughness, and FIG. 15 to FIG. 22 are diagrams showing the measurement results of the cross-sectional shape. 1 ... 1st rotating shaft, 6 ... upper blade holder, 7 ... 1st
Upper blade as a knife of 11 ... Second rotary shaft, 19 ... Second
Lower blade as a blade of, 22,22B ... Cut blade, 23,23B ... Spacer and mounting.

Claims (2)

[Scope of utility model registration request] 1. A first blade having a thin cutting blade and supported by a first rotating shaft, and a cutting blade portion in contact with the cutting blade of the first blade, and the first blade. A slitter having a relief groove for the cutting edge of the blade and supported by a second rotating shaft, wherein the cutting edge portion of the second blade is formed of cemented carbide. At the same time, the slitter is characterized in that a portion other than the cutting edge portion is formed of a powder sintered alloy. 2. The slitter according to claim 1, wherein the powdered sintered alloy contains 0.8 to 2.7 wt% of C and 1.5 to 15 wt% of W.
%, Mo is 1.3 to 9.5 wt%, V is 1 to 9.8 wt%, Co is 0 or 5 to 12 wt%, and Cr is 3.7 to 5.3 wt%.