JP2665565B2 - Cutlery for planing wood - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial applications In the wood processing and similar processing fields, blades suitable for performing flat-cutting by super-finishing planes, disk planes, hand planes, etc. It is suitable for super-finished planing machines of the so-called auto return type, which are cut during one-way feeding (cutting feeding) and conveyed while rubbing the cutting edge from the flank side during reverse feeding (returning). Regarding cutlery.

2. Description of the Related Art Research has been conducted to apply the PVD method, which has been successful as a coating technique to steel cutting tools, particularly a method called ion plating, to cutting wood and the like. For example, (1) Saw tips with self-sharpening characteris-
tics, Eber Kirbach et al., 8th Wood machining Semi
ner Abstract "Wood Industry"'86 .4.P40 In this report, we used cemented carbide chips as a base material and sawed Al ₂ O ₃ -T
The results show that self-polishing characteristics can be obtained by performing iC (CVD method) coating. However, they point out that this self-polishing property is still unsatisfactory for practical use, and that a base material that synchronizes the wear rate of the base material and the coating layer best should be used.

(2) "Performance of TiN-coated tools in Wood c
utting '' MSSulonen, Surface and Coating Technolong
y 33 C'87 P141-P151 This report describes TiN coating on cemented carbide and high speed steel. The cemented carbide chip was coated with TiN (ion plating method) 0.7-1.0μm to reduce the scooping surface wear by 50% when cutting the hard board, but when cutting the particle board, paper board and plywood , There was no coating effect,
In addition, the result of cutting the spruce with a high-speed steel cutter having the same coating shows that the scooping surface wear was reduced by about 20% as compared with the untreated blade, but none of them showed much effect.

(3) "Wear characteristics of TiN-coated high-speed steel bits" Kaoru Banshoya et al., Proceedings of the 38th Annual Meeting of the Japan Wood Science Society (1988) About 2μm with TiN (ion plating)
After drilling holes in merapi, spruce, semi-hardboard and plywood, there is no noticeable difference in wear progression compared to untreated bits. Woodworking bits have good results as in the field of metal cutting. It was not. As described above, it is difficult to apply the conventional coating technology to wood cutting as it is.

Problems to be Solved by the Invention In the field of wood cutting, unmanned, automatic operation and high-precision, high-operation processing are being pursued. Cutting tools are changed from high-speed steel to cemented carbide, and from re-sharpening dies. The trend is to shift to the throw-away replacement blade method, and it is an issue to reduce the ratio of the blade cost to the production value. In addition, in order to effectively use the PVD method, which has been used in steel cutting tools, steel sheet shearing tools, and slitter knives for papermaking, for wood finishing cutters, it is necessary to find coating materials and techniques suitable for this application. It is an issue.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and has as its object the purpose of mass production with high cost, low blade sharpness by polishing, and long life wood planing. It is intended to provide a knife.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a cutting tool for wood planing using any one of high-speed steel, tool steel such as high chromium alloy tool steel as a cutting tool base material, Either the flank surface or the scooping surface includes at least Cr ₂ N or a chromium nitride layer composed of a mixture of CrN or Cr ₂ N and a crystal structure exhibiting a clear X-ray diffraction peak on the (200) plane. The layer is coated by the ion plating method to a thickness of 0.2 to 6.0 μm, so that the uncoated surface is preceded by abrasion.

Action Cr ₂ N or clear X-ray diffraction intensity is shown on the flank or scooping surface of the finishing plane blade by arc discharge ion plating method etc. (20
0) what chromium nitride layer consisting of a mixture of CrN or CrN and Cr ₂ N crystal structure of the surface fold-out is that is coated, for example, in 0.3μm thickness Doing attachment timber finish cutting the superfinishing planer, A beautiful finished cut surface can be obtained with a long service life due to the self-polishing property in which the sharpened cutting edge is regenerated in advance of wear of the uncoated scooping surface or flank surface.

Embodiment First, the process of solving the problem will be described. By applying hard chrome plating or coating with vanadium carbide by the molten salt method on the flank of the blade, the scooping surface is selectively worn, and the self-polishing characteristic that the sharp edge is regenerated generates a beautiful cutting surface. We succeeded in obtaining the longevity (Japanese Wood Processing Technology Association 5th Conference Lecture Abstracts).

However, if the flat surface is cut by the auto return method (Fig. 1), which has recently become the mainstream in the cutting method of a super-finished planing machine, using a cutting tool coated with hard chrome on the flank, the feeding belt will Pressure (blade length 250mm
Because the work material is conveyed while strongly pressing the cutting edge from the flank side of the cutting tool, the microcracks unique to hard chrome plating develop in the vicinity of the cutting edge of the hard chrome coating layer on the flank side. However, it was found that the material was worn out by the minute dropping and that the self-polishing property was not sufficiently exhibited. Also, when hard chrome is coated on the scooping surface of the blade, tensile stress acts on the scooping surface due to the bending action by the back force at the time of cutting, similarly micro cracks develop and are worn out by minute falling off, and the self-polishing characteristics are sufficient. Not demonstrated. Also, hard chrome plating has poor uniform electrodeposition properties, so in order to obtain a uniform film thickness over the entire length of the blade, it is necessary to make the current density distribution uniform according to the shape of the blade, and the productivity is not necessarily good. There was another problem.

In addition, since the molten salt method is processed at a high temperature of 800 to 1000 ° C., it is necessary to perform quenching and tempering after that, and there is a problem in mass production such that distortion is easily generated.

As a result of further research, tool steels such as high-speed tool steel and high chromium alloy tools were used as test specimen base metals, and TiN, TiC, VN and ZN were formed by the PVD method.
As a result of coating the nN on the flank and cutting the wood after confirming that the desired substance was coated by an X-ray diffraction method, almost no wear suppressing effect was recognized.

However, in order to execute the arc discharge ion plating method, which is a kind of PVD method, chromium is evaporated and ionized by arc discharge and N ₂ is introduced as a reaction gas under a condition shown in Table 1 in a vacuum chamber, and a negative voltage is applied. Chromium nitride layer thickness 0.2 ~ 6.0μ on flank of knives with SKH-51, SKS-2 as base material
m, and the coated surface was measured by the X-ray diffraction method. As shown in FIG. 2 to FIG.
(200) plane and (111) (110) (112) (002) planes of Cr ₂ N have clear diffraction peaks, so it was confirmed that the desired substance was coated. As a result, a good wear suppressing effect was confirmed.

Furthermore, the same effect is obtained by applying the same coating by thermionic activation ion plating method, in which the chromium in the crucible is evaporated by resistance heating and ionized by thermal filament, and the HCD method, in which chromium is evaporated and ionized using an enamel cathode gun, etc. Was confirmed.

The reason why chromium nitride is effective for planing wood is that the mechanical abrasion effect is small in wood cutting,
On the other hand, the deterioration of the surface layer of the cutting edge due to chemical reactions such as corrosion and oxidation greatly contributes to the progress of abrasion. Therefore, not only hardness but also chemical stability such as corrosion resistance and oxidation resistance are reduced. It is necessary to suppress wear, and it has been found that the properties of chromium, which is an additive element to steel and cemented carbide, which has a large effect of imparting corrosion resistance and oxidation resistance, advantageously act.

The coating layer thickness is regulated for the following reasons.

・ Cutting performance when chromium nitride exceeds 6.0μm Cutting tools for planing wood may cut Apitan and Merapi (South Sea), which contain silica (SiO ₂ ) in the work material. The silica contained therein causes the cutting edge to be worn more than when cutting a general material.

Table 2 shows the chromium nitride (CrN) layer thickness (scooping surface coating) and the amount of retreat of the cutting edge when cutting Apiton material, and Figs. 5 and 6 show the cutting die. Table 2 also shows the amount of retreat of the cutting edge of the untreated SKH-51 finish plane blade, but the cutting edge wear state is almost similar to the shape shown in FIG. From this result, as the scooping surface coating layer thickness becomes thicker, the retreat amount of the cutting edge is smaller and wear is reduced,
On the other hand, the tip of the cutting edge tends to crack due to the internal stress in the coating layer according to the layer thickness, the layer is damaged, the sharpness deteriorates, and when the layer thickness exceeds 6.0 μm, the cutting depth of the work material is poor The function of pressing the cutting surface works, and the cutting surface is poor, and is not suitable as a finish plane blade. In general wood finishing, a sharper cutting edge is usually required, so the upper limit of the layer thickness is 6.0 μm.

・ Cutting performance with less than 0.2μm of chromium nitride In rotary cutting, no good wear-reducing effect was observed with a chrome nitride layer thickness of 0.5μm or less. Since there was no intermittent impact, the wear of the cutting edge was slow, and the wear suppressing effect was obtained even with a relatively thin layer thickness.

However, if the thickness is less than 0.2 μm, the chromium nitride coating layer is worn away at an early stage of cutting and the base material is exposed. Subsequent cutting has the same form of wear as untreated, and untreated 1.5
Only about twice the cutting performance can be obtained. Therefore, the lower limit of the film thickness is 0.2 μm.

From the above results, the practical coating layer thickness is 0.2 ~
6.0 μm. As a wood planing blade, a thing that wears the edge well like Apiton material, a thick layer is suitable, but in general, the sharpness is very required in finish cutting. 3.0 μm is preferred.

-Test 1-In wood finish cutting, the edge line roughness after polishing is important, so that the cutting ability by polishing was confirmed.

Sample blade A: Base metal SKH-51 finish plane blade CrN1.0μm coating Sample blade B: Base material SKH-51 finish plane blade CrN1.7μm coating Sample blade C: Base material SKH-51 finish plane blade Untreated blade FIG. 7 shows the results obtained by coating the edge portion and polishing from the flank side, and measuring the edge line roughness using a surfcom manufactured by Tokyo Seimitsu Co., Ltd.

In the case of the unprocessed one (knife C), traces of the grinding edge of the cutting edge generated by rough sharpening remain after the finish sharpening and are transferred to the finished surface.

The coated material (knife A, B) does not produce sharpening during rough sharpening, and therefore has no trace of sharpening after finishing sharpening, so that a beautiful finished surface can be obtained.

In the blade B, slight spilling of the blade edge is recognized due to the effect of the coating film thickness increasing.

From the above, it was confirmed that the sharpness of the coated blade was improved by polishing. In particular, in the case of finish cutting in which a high-quality cutting surface is required, improvement of the initial sharpness is very effective.

-Test 2-Cutting life test by auto return flat milling Sample blade D: Base material SKH-51 finish plane blade CrN 1.7 µm scooping surface coating Sample blade E: Base material SKH-51 finish plane blade No treatment Work material: Spruce Diagonal angle: 25 ° Cutting speed: 65m / min Depth of cut: 0.06mm As shown in Fig. 8, in the case of cutting with an untreated blade E, the cutting edge becomes round at a cutting length of 1000m, and from the condition of the cutting surface It is considered a general cutting life.

As shown in FIG. 9, the blade D coated on the scooping surface had an effect of suppressing abrasion even after cutting 2,000 m, and the cutting edge was maintained sharp because of the self-polishing property, so that continuous cutting was possible.

From the above, it is estimated that the improvement of the cutting life by the scooping surface coating is at least twice as long as that of the non-treatment, and that the life is considerably long from the abrasion state and the like.

-Test 3-Cutting life test by auto return flat milling Sample blade F: Base material SKS-2 Finish plane blade CrN 0.72μm flank surface coating Sample blade F: Base material SKH-51 Finish plane blade No treatment Work material: Spruce Diagonal angle: 25 ° Cutting speed: 65m / min Depth of cut: 0.06mm As shown in Fig. 8, in the case of cutting with an untreated blade E, the cutting edge becomes round at a cutting length of 1000m, and from the condition of the cutting surface It is considered a general cutting life.

As shown in FIG. 10, the blade F coated on the flank had an effect of suppressing abrasion even after cutting 1000 m, and the cutting edge was sharpened by the self-polishing property, so that the cutting edge could be further cut continuously.

From the above, it is supposed that the improvement of the cutting life by flank coating of SKS-2 material, which is a cheap material, is at least about the same as that of SKH-51 material without treatment, and the life is considerably long from the abrasion state.

-Test 4-Auto return flat cutting life test Sample G: Base material SKH-51 Back blade integrated type spare blade (Fig. 11) Cr ₂ N
1.3μm, flank coating Tool to be tested H: Base metal SKH-51 Back blade integrated type spare blade No treatment Work material: spruce Slant angle: 25 ゜ Cutting speed: 65m / min Depth of cut: 0.06mm Untreated blade In the cutting by H, as shown in FIG. 12, a rounded edge is observed at a cutting length of 1000 m, which is regarded as a general cutting life.

As shown in FIG. 13, the cutting with the flank-coated blade G has an effect of suppressing abrasion even after cutting 2,000 m, and the self-polishing property has a sharp edge and a good cut surface, so that further continuous cutting is possible. It is estimated from the abrasion state that the life is considerably long.

In addition, as a blade, it can be applied to the super-finishing plane blade shown in FIG. 1 of a re-grinding type which has been widely used in the past. Also, it can be applied to a super-finished plane blade of a back blade superimposed type replacement blade (FIG. 14).

The flank coating on the integrated blade is, for example, a gap formed between the rake surface and the flank surface when the scoop surface is directly attached by contacting the scoop surface with a cylindrical jig, so a coating layer is also formed on the scoop surface. Is done. Therefore, it is possible to prevent the coating on the scooping surface by performing jig processing to reduce the gap between the scooping surface and the jig surface of the integrated replaceable blade. As another method, a masking substance is mainly applied on the scooping surface before coating, and then the flank is sharpened and polished to perform a predetermined coating.

Effects of the Invention As described above, the present invention has the following effects.

Since it contains a chromium nitride layer, the properties of the additive elements that impart corrosion and oxidation resistance to steel and cemented carbide have an advantageous effect, and the surface layer of the cutting edge due to chemical reactions such as corrosion and oxidation due to components contained in wood. Less alteration of

The chromium nitride Cr ₂ N and (200) crystal structure representing a distinct X-ray diffraction peaks at surface CrN or CrN and Cr ₂ N corrosion such as a mixing of the above, moderate and oxidation resistance Because of the hardness, and the coating by the ion plating method does not have microcracks as in the hard chromium plating layer, even if it is coated on either the scooping surface or the flank surface, the wood is an auto return type finisher Even when flat-cutting, there is no micro-dropping, good wear control effect is exhibited, and the coating is applied only on one side with a film thickness of 0.24μm to 6.0μm, so the wear is applied to the non-coated side ahead of the coated side. Wear is suppressed on the coating surface side, the roundness of the cutting edge is kept to a minimum, and sharpness is maintained. Therefore, even if high speed steel or the like is used as the base material and the flank or scooping surface is coated, a beautiful and highly accurate cut surface without fluffing, reverse blindness, misalignment, etc. can be obtained. The sharpness lasts longer and the base material can be made of a relatively inexpensive material such as SKS, resulting in lower costs including coating costs. Further, since the cutting edge is sharp, cutting power and cutting noise can be reduced.

[Brief description of the drawings]

FIG. 1 is a view showing a cutting portion of an auto return type finishing plane machine,
2, 3, and 4 are diagrams showing the X-ray diffraction intensity of the coated surface, and FIG. 5 is a diagram of the state of wear of the cutting edge after cutting the apiton material 1000m when the scooping surface is coated with 2.8 μm.
Fig. 6 is a diagram showing the wear state of the cutting edge after cutting 1,000 m of Apiton material when the scooping surface is coated with 5.5 µm. Fig. 7 is a cutting tool.
FIG. 8 shows the edge line roughness of A, B and C, and FIG.
9 is a diagram of the wear of the cutting edge after cutting 1000 m of spruce material, FIG. 9 is a diagram of the wear of the cutting edge after cutting 2000 m of spruce material of the cutting tool D having a 1.7 μm coating on the scooping surface, and FIG. 10 is a coating of 0.72 μm on the flank surface. Of the blade edge after cutting 1000 m of spruce material of the cutting tool F, FIG. 11 is a view of a replaceable blade integrated with a back blade, and FIG. 12 is a cutting tool H of FIG. 11 after cutting 1000 m of spruce material. FIG. 13 is a view showing the state of wear of the cutting edge, FIG. 13 is a view showing the state of wear of the cutting edge after cutting the spruce material by 2000 m, and the flank is similarly coated with 1.3 μm. FIG.

 ─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-2-175858 (JP, A) JP-A 64-87202 (JP, A) JP-A 2-129360 (JP, A) Actual development Sho-62- 188306 (JP, U) Actual flat 2-106305 (JP, U) Actual public Sho 61-986 (JP, Y2)

Claims (1)

(57) [Claims] Claims: 1. A cutting tool for wood planing using one of tool steels such as high-speed steel and high chromium alloy tool steel as a base material, wherein at least one of a flank surface and a scooping surface has at least Cr ₂ N.
C of crystal structure showing a clear X-ray diffraction peak on the (200) plane
rN or CrN and Cr ₂ N the layer comprising chromium nitride layer consisting of a mixture of coated by ion plating method 0.2~6.0μm thickness, that wear of the uncoated surface is configured to preceding Characteristic wood planing knife.