RU2096166C1 - Method of moulding abrasive tool - Google Patents

Abstract

FIELD: abrasive industry. SUBSTANCE: method comprises rolling abrasive mixture into plates, cutting out rings blank from the plates, assembling the ring to provide a stack on the rod, packing the stack, and pressing. EFFECT: simplified method. 2 dwg

Description

 The invention relates to the abrasive industry, namely the manufacture of predominantly large-sized abrasive wheels on a volcanic bond.

A known method of manufacturing an abrasive tool (grinding and polishing wheels) on a volcanic bond with an outer diameter of more than 250 mm, a height of more than 100 mm, including preparing the abrasive mixture, rolling the mixture into plates, cutting rings out of them, a set of rings of a bag consisting of 2 30 or more rings, subsequent compression of the bag in the mold on the presses and vulcanization of the presses [1]
The disadvantage of this method is the large percentage of defective defects in the form of a layer along the lateral contact planes of individual rings. Moreover, these defects can only be detected in the operations of mechanical turning of circles after vulcanization in diameter with a diamond tool.

 The closest in technical essence and the achieved effect to the proposed is a method of forming an abrasive tool on a volcanic bond, including rolling the abrasive mixture into flat billets with a thickness of about 10 mm or more, cutting down from these header rings with an outer diameter of 250 500 mm or more and an inner diameter of 127 365 mm, a set of these rings on the core and the lower mold ring [2] In this case, when a set (approximately 8 31 rings) each subsequent ring is compacted to remove air on the surfaces of their contact, smoothing aniem palms of the hands. Then, the package assembled on the rod is installed in the mold matrix, manually sealed using the upper ring of the mold, after which the package is pressed with a force of, for example, 630 tons.

 A significant disadvantage of this method is the insufficient preliminary manual sealing of the rings on the core of the mold before the main pressing operation. Part of the air remains on the contact surfaces of the rings; in the process of pressing, the air interferes with the compression of the rings on separate sections of the contact surfaces. It is not possible to eliminate air during the subsequent sintering operation and therefore there are delamination defects on the finished products.

 The objective of the proposed invention is to eliminate this drawback, namely reducing the bundle of the finished abrasive tool.

The problem is achieved in that in the method of forming an abrasive tool on a volcanic bond, including rolling the abrasive mixture into plates, cutting ring blanks from a plate, assembling rings into bags on a core, pre-compaction and further pressing into a mold, according to the invention, pre-compaction on the press outside the matrix with a force of (0.1 0.2) P _p , where P _{p is the} pressing force in the mold.

 When pre-pressing in the claimed modes, there is an almost complete removal of air from the contact surfaces of the rings, as a result of which the further separation reduces the separation.

 With a pre-pressing force of less than 0.1, complete removal of air from the contact surfaces of the rings is not ensured, and the reject percentage is not reduced.

 With a pressing force of more than 0.2, a barrel is formed on the bag and the bag is not included in the mold matrix for final pressing.

 In FIG. 1 shows a bag before pressing, FIG. 2 bags after pre-pressing.

 In FIG. 1, 2 are marked: 1 mold core, 2 lower mold ring, 3 upper mold ring, 4 pack of 13 rings, 5 barrel on the pack after pressing.

 The method is as follows.

After rolling the abrasive mixture into plates and cutting down from the plates of the rings 4, they are collected on the rod 1 and the lower ring 2 of the mold. Then, a force P equal to (0.1, 0.2) P _{p is} applied to the upper ring 3, and the assembled pack of rings 4 is pre-pressed. After that, the previously sealed pack of rings 4 on the rod 1 is installed in the mold, where it is finally molded.

According to the proposed method, vulcanite bonded grinding wheels with an outer diameter of 500 mm, an inner diameter of 305 mm and a thickness of 250 mm were made. The pressing force in the mold was 630 tons. The preliminary pressing was carried out on a press without a matrix with a force of 0.08 P _p , 0.15 P _n , 0.2 and 0.25 P _p .

The test data showed that when pre-pressing with a force of 0.08 P _{p the} separation of the finished circles was 40% at 0.1 P _p 0.2; at 0.15 P _p 19%
at 0.2 _p - 13% and at 0.25 _p it was not possible to set the packet of rings into the matrix (the “barrel” interfered).

 The proposed method is advisable to use in the abrasive industry to obtain large-sized polishing and grinding abrasive tools on a volcanic bond in the form of circles such as PP and PVD.

Claims (1)

A method of forming an abrasive tool, in which a vulcanite molding abrasive mixture is taken, rolled into plates, annular blanks are cut from the plates, which are assembled into a bag on a rod, after which the bag is pre-compacted and finally pressed into a mold, characterized in that the ring bag preforms are pre-compacted on a press without a matrix with a force P (0.1 0.2) P _p , where P _{p is the} pressing force in the mold.

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