JPH022672B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) This invention can be attached to a belt polishing machine etc. to remove metals.
The present invention relates to an abrasive belt used for grinding and polishing wood, etc., and provides an abrasive belt with excellent abrasive power and durability. (Prior technology) An abrasive belt uses high-hardness abrasive grains made of molten alumina, silicon carbide, alumina, zirconia, etc., arranged in a predetermined particle size, on the surface of a paper or woven fabric base material using an adhesive such as phenolic resin or glue. It is coated and fixed in a single layer or at most 2 to 3 layers to form an endless belt, and most abrasive belts are so-called closed coats in which the surface of the base material is completely covered with abrasive grains. It is a type. In actual polishing work, fracture of the abrasive grain cutting edge during the initial stage of polishing is unavoidable due to the structure of the polishing belt, and because the number of applied abrasive grains is large, the amount of active abrasive grains decreases as the polishing time progresses. As the number of abrasive grains increases rapidly, the flank wear area of the abrasive grains also increases, resulting in a significant increase in polishing resistance and a decrease in polishing ability in a relatively short period of time. Furthermore, when the workpiece is a soft material, grinding chips are often generated, and these chips firmly adhere between the abrasive grains, resulting in a so-called clogging phenomenon, resulting in a rapid decline in polishing ability. There are many. Therefore, the current situation is that even if only a small portion of the tip of the abrasive cutting edge is used, the service life is reached when most of the abrasive grains remain on the base material. In order to eliminate the above-mentioned drawbacks, open-coated abrasive belts are used in which abrasive grains are attached to about 50 to 80% of the base material area. However, although this type has good chip ejection, due to its structure, the load applied to each abrasive cutting edge is large, so the abrasive cutting edge is crushed in the initial stage of polishing, and the abrasive grains are not consumed effectively. Due to its lack of rigidity as an abrasive tool compared to closed-coat types, it has a shorter lifespan than closed-coat types, and is limited to very narrow applications such as light grinding of woodworking and polishing of soft metals. On the contrary, an attempt was made to apply a large number of abrasive grains, control the adhesive strength of the abrasive grains to the base material, and use up the abrasive grains until there were no more on the base material, while allowing the abrasive grains that had done some work to fall off appropriately. However, it is not easy to optimally control the adhesive strength; if it is too strong, the above-mentioned phenomenon will occur, and if it is too weak, the abrasive grains will fall off significantly. However, with an abrasive belt coated and fixed in two to three layers, this method cannot be expected to extend its life. As described above, in conventional abrasive belts, expensive abrasive grains are not effectively utilized, which is a major factor in increasing the cost of belt grinding processing as well as having drawbacks in terms of performance. (Problems to be Solved by the Invention) The present invention solves the drawbacks of the conventional abrasive belts described above, namely, the increase in the total area of abrasive flank wear during the middle and later stages of polishing due to the large amount of abrasive grains being applied. This causes a decrease in polishing power and the occurrence of machining burn, leading to the end of the service life when only a portion of the abrasive grains are used, such as the tips of the abrasive grains, and the clogging phenomenon caused by the polishing chips, which decreases the polishing ability and shortens the service life. In addition, if you apply less abrasive grains to reduce the number of active abrasive grains, the load applied to each abrasive cutting edge will be large, which will cause the abrasive cutting edge to break up greatly in the early stage of polishing, and the abrasive will This abrasive belt has significantly greater durability because it does not wear out effectively, and also solves the problem that the rigidity of the abrasive belt is insufficient compared to the closed coat type due to its structure, making it difficult to make sufficient cuts in the middle and later stages of polishing. This is what we are trying to provide. (Means for Solving the Problems) In order to solve the above-mentioned drawbacks of conventional abrasive belts, the present inventors have conducted various studies and found that the present inventors have developed a new abrasive belt with a Mohs hardness of 2 to 7 and with approximately the same particle size as the abrasive grains. An abrasive belt in which abrasive grains are coated alone or mixed with abrasive grains and low-hardness mineral particles are applied and fixed to the entire surface of the belt base material, which is pre-patterned with low-hardness mineral particles in round, square, or diagonal striped patterns. This suppresses the increase in the number of active abrasive grains, and the low hardness mineral particles do not inhibit the polishing action, making effective use of the abrasive grains, dramatically improving durability compared to conventional methods. This is what I found. The present invention will be explained below based on the drawings. 1st
1 and 2 are enlarged sectional views of the abrasive belt of the present invention. First, low-hardness mineral particles 3 having approximately the same particle size as the abrasive grains 2 and having a Mohs hardness of 2 to 7 are applied to the surface of a belt base material 1 such as woven fabric or paper that has been treated to suit the purpose.
Patterns such as circles, squares, and diagonal stripes are created and fixed at pitches of mm or less. To pattern low-hardness mineral particles, apply the adhesive 4 in a predetermined pattern using a stamping roll such as an intaglio or letterpress, and then apply the low-hardness mineral particles to the adhesive-applied area using an electrostatic coating method or gravity falling method. , stick. Next, after applying adhesive 4 to the entire surface using a conventional method, abrasive grains 2 are applied uniformly and densely using an electrostatic coating method, and then an upper layer adhesive 4 is applied to firmly fix each particle. , as an abrasive belt. In FIG. 2, the same particles as the low-hardness mineral particles 3 previously patterned are mixed with abrasive grains 2, uniformly and densely applied to the entire surface, and fixed. When patterning low-hardness mineral particles on a belt base material, the shape of the pattern, pitch interval, and area ratio to the base material should be such that the contact is smooth and the shock caused by intermittent contact is small when polishing with an abrasive belt. It must satisfy the objectives of not causing clogging, controlling the number of working abrasive grains so that wear and tear of the abrasive grains progresses smoothly, and effectively consuming and utilizing the abrasive grains to the end. . The shape of the pattern may be any suitable shape, such as a round or square plover pattern as shown in A, B, and C of FIG. 3, or a diagonal striped pattern. The repeating interval of the pattern, that is, the pitch, is 20mm.
Preferably within If it exceeds 20 mm, the workpiece will be hit intermittently during use, making smooth polishing impossible. Furthermore, the area occupied by the low-hardness mineral particles to be patterned on the surface of the base material is preferably in the range of 30 to 70%. If it is less than 30%, there are too few abrasive grains applied on top, and the number of abrasive grains that work in the initial stage of polishing is small and the polishing force is small, but on the other hand, the abrasive grains are consumed and the first layer of abrasive grains become active. On the contrary, the number of active abrasive grains increases at this stage, resulting in the same drawbacks as the conventional closed coat type. In addition, if it exceeds 70%, the number of abrasive grains on the surface is too large even though two layers are applied, which also causes the same drawbacks as the conventional closed coat type. The abrasive grains used in polishing belts are fused alumina, silicon carbide, alumina zirconia, etc., and the hardness of these abrasive grains is 8 on the old Mohs hardness scale.
That's all. In addition to the above abrasive grains, so-called superabrasive grains such as diamond abrasive grains can also be effectively used as the abrasive grains used in the present invention. Suitable low-hardness mineral particles to be patterned in advance are mineral particles with a former Mohs hardness of 2 to 7, and gypsum, cryolite, borax, barite, fluorite, wollastonite, feldspar, silica, etc. are effective. Available. If the hardness is less than 2, it is too soft and cannot firmly support the abrasive grains applied to the top layer.If the hardness is higher than 7, which is close to the hardness of the abrasive grain, the upper abrasive grains will wear out and cause damage to the lower layer. When the abrasive grains perform a polishing action, abrasion and fracture do not proceed any further than the abrasive grains, resulting in the same drawbacks as the conventional closed coat type. In addition, these low-hardness mineral particles are
It must not have any negative chemical effects on the processed product. The grain size of the abrasive grains used in the polishing belt is specified in JIS R 6001, but in the present invention, if the grain size of the abrasive grains is, for example, #60, it is desirable that the grain size of the low hardness mineral particles is approximately #60.
Even if the particle size is smaller or larger than this, the action and effect of the present invention cannot be expected. In addition, after patterning and fixing the low-hardness mineral particles, abrasive grains are applied to the entire surface alone or a mixture of the low-hardness mineral particles and the abrasive grains is applied, and the mixing ratio of both is 10:0 to 10:0 by volume.
A range of 3:7 is preferred. This ratio depends on the type, hardness, friability, and
In order to control the number of abrasive grains that act on the workpiece in relation to the area ratio occupied by the belt base material, and to maintain the polishing action for a long time by effectively abrading and abrading the abrasive grain cutting edge without crushing it. Mixing ratios up to 3:7 are useful for purposes of the present invention. The superiority of the abrasive belt of the present invention will be specifically explained below with reference to Examples. Example 1 A cotton cloth base material treated to suit the purpose using colored alumina abrasive #46 as the abrasive grains and feldspar (hardness 6) adjusted to approximately #46 as the low-hardness mineral particles. After applying the phenolic resin adhesive in a diagonal striped pattern upward to the left using a letterpress coating roll, the feldspar particles were applied using a gravity fall method. At this time, the pitch of the striped pattern is 15 mm, and the particle adhesion area is 7.5 mm.
The width of the non-adhesive part was 7.5 mm. After drying and fixing, adhesive is applied to the entire surface, and particles made by mixing colored alumina abrasive grains and feldspar in a volume ratio of 1:1 are applied using an electrostatic coating method.Finally, a top coat adhesive is applied to each particle. was firmly fixed to form an abrasive belt. Example 2 Colored alumina abrasive material #46 was used as the abrasive grains, and fluorite (hardness 4) whose particle size was adjusted to approximately #46 was used as the low-hardness mineral particles, and a cotton fabric base was treated to suit the purpose. After applying phenolic resin adhesive to the material using a letterpress coating roll in a 5mmφ round shape with 7mm pitch spacing, fluorite particles were applied.
It stuck. Next, after applying adhesive to the entire surface of the base material, colored alumina abrasive grains are applied individually using an electrostatic coating method, and finally, a top coat adhesive is applied to firmly adhere each particle to the abrasive belt. did. In order to conduct a comparative test with the abrasive belts obtained in Examples 1 and 2, a closed coat type (conventional general product) with a coating density of 100% using #46 and colored alumina abrasive grains, and Examples An abrasive belt with the same diagonal striped pattern as in No. 1 was prepared by coating only #46 colored alumina abrasive grains in one layer without using low-hardness mineral particles, and with a coating density of 50%. A comparative test was conducted by polishing stainless steel SUS304 with these polishing belts, and the results are shown in Table 1 as a ratio when the conventional general product is set as 100.

[Table] (Effects of the Invention) As is clear from the results in Table 1, when comparing the total polishing amount and life time of the conventional general product and the present invention's abrasive belt, the present invention's abrasive belt is superior to the conventional general product. Performance has improved by 60-80% compared to conventional products.
In particular, compared to an abrasive belt with a diagonal striped pattern and a coating density of 50%, the amount of abrasiveness and service life was two to three times greater.
This is a result of the effective use of abrasive grains, which is the objective of the present invention. After the abrasive grains fixed to the convex portions of the pattern are abraded by the abrasive action, low-hardness mineral particles appear on the surface. , the low-hardness mineral particles are moderately crushed by contact with the workpiece, and the wear is greater than that of the abrasive grains, and the polishing action of the abrasive grains fixed in the patterned recesses is not inhibited until the end.Moreover, the structure of the abrasive belt Because of its high rigidity, the drop in polishing power is suppressed, and the abrasive grains are effectively worn down to the end, resulting in improved durability.

[Brief explanation of drawings]

Fig. 1 is an enlarged sectional view of an abrasive belt of the present invention, Fig. 2 is an enlarged sectional view of an abrasive belt according to another embodiment of the invention, and Fig. 3 is an enlarged sectional view of an abrasive belt according to another embodiment of the present invention. It is a top view which shows some examples. 1... Belt base material, 2... Abrasive particles (abrasive grains),
3...Low hardness mineral particles, 4...Adhesive.

Claims (1)

[Scope of Claims] 1. In an abrasive belt in which abrasive particles (hereinafter referred to as abrasive grains) are coated and fixed on a belt base material, low-hardness mineral particles having a Mohs hardness of 2 to 7 and having approximately the same particle size as the abrasive grains are applied. Polishing characterized by applying and fixing abrasive grains alone or in combination with abrasive grains and the above-mentioned low-hardness mineral particles on the entire surface of a belt base material that has been patterned and fixed in advance in round, corner, or diagonal striped patterns. belt. 2. Round low hardness mineral particles with a pitch of within 20 mm.
The abrasive belt according to claim 1, which uses a belt base material which has been patterned in advance with corners, diagonal stripes, etc. and is fixed. 3. The abrasive belt according to claim 1, wherein the area occupied by the patterned and fixed low-hardness mineral particles is 30 to 70% of the area of the base material. 4 The mixing ratio of the abrasive grains and the low-hardness mineral particles applied to the entire surface of the belt base material on which the low-hardness mineral particles are patterned and fixed in advance is 10:0 to 3:7 in terms of volume ratio.Claim 1 Abrasive belt as described in section.