The present invention relates to abrasive tools and method of manufacturing of the abrasive tools.
Abrasive tools, for example diamond tools, are known, which have a tool body and abrasive-containing pellets attached to the tool body. Each of the abrasive-containing pellets in the known abrasive-containing tools contains a plurality of abrasive grains connected with each other by a binder composed for example of a metal powder, a resin, etc. The abrasive-containing pellets are connected with the tool body by an adhesive layer.
The known abrasive-containing tools cited hereinabove have however disadvantages in that the connection of the abrasive-containing pellets to the tool body is not sufficiently strong to execute the processes of machining of corresponding parts with high pressures and high speeds, since the machining with these high parameters results in detaching of the abrasive-containing pellets from the tool body. Also, this does not allow to use such abrasive tools until the abrasive-containing pellets are completely worn out and the whole quantity of the diamond grains is utilized.
Accordingly, it is an object of the present invention to provide an abrasive-containing element, an abrasive tool with a plurality of abrasive-containing elements, and a method of manufacturing the same, which avoid the disadvantages of the prior art.
In keeping with these objects and with others which will become apparent herein after, one feature of the present invention resides briefly stated, in a abrasive-containing element having a pellet provided with an abrasive-containing layer and an abrasive-free layer, and at least one holding member having one end connected with the abrasive free-layer of the pellet and a shaft introducible into a tool body to connect the abrasive-containing element with the tool body.
When the abrasive-containing element is designed according to the present invention, it ensures a strong connection of the pellets to the tool body, thus allowing a high-pressure high-speed machining of parts with an abrasive tool equipped with such abrasive-containing elements, and at the same time it also ensures a long service life of the abrasive-containing elements till the abrasive-containing layers of their pellets are completely used.
According to a further feature of the present invention the holding member can have a head provided at its one end and embedded in the abrasive-free layer of the pellet, and the shaft can be threaded and screwable into the tool body.
According to a further feature of the present invention the head of the holding member embedded in the abrasive-free layer of the pellet can have a cross-section narrowing from the one end of the holding member towards the treaded shaft.
According to a further feature of the present invention the abrasive-containing element having a pellet provided with an abrasive-containing layer and an abrasive-free layer, has more than one holding member each having one end connected with the abrasive-free layer of the pellet and the shaft introducible into a tool body.
According to a further feature of the present invention, an abrasive tool is provided which contains a tool body and a plurality of abrasive-containing elements connected to the tool body and each having a pellet provided with an abrasive-containing layer and an abrasive-free layer and at least one holding member having one end connected with the abrasive-free layer of the pellet and a shaft introducible into the tool body.
According to a further feature of the present invention, a method of manufacturing a diamond tool is provided, which contains the steps of making a tool body, making a plurality of abrasive-containing elements and each having a pellet provided with an abrasive-containing layer and an abrasive-free layer and at least one holding member having one end connected with the abrasive-free layer of the pellet and a shaft, and the shaft of the holding member of each of the abrasive-containing elements is introduced into the tool body to connect the abrasive-containing elements with the tool body.
The present invention will be described in detail hereinbelow with the reference to the accompanying drawings.
An abrasive-containing element in accordance with one embodiment of the present invention is shown in
The pellet 2 is provided with an abrasive-containing layer 4 and an abrasive-free layer 5. The abrasive-containing layer 4 of the pellet 2 has a plurality of abrasive grains, for example diamond grains 6 embedded in a binder 7 which can be composed of metal, resin, or other materials.
The holding member 3 has a first end 8 connected with the abrasive-free layer 5 of the pellet 2 and another opposite end 9 with which it is insertable into a tool body, as well be explained in detail hereinbelow. The first end 8 preferably has a head portion 10 which narrows towards a shaft 11 of the holding member. The shaft 11 of the holding member 3 can be provided with a thread 12 so that it can be screwed into the tool body. The head portion 10 connects the pellet 2 of the abrasive-containing element 1 with the holding member 3.
The abrasive-containing element in accordance with another embodiment of the present invention is shown in
An abrasive-containing element in accordance with a further embodiment of the present invention is shown in
An abrasive-containing element in accordance with a further embodiment of the present invention is shown in
According to a very important feature of the present invention, the first end 8 with a part of the head portion 10 of the holding member 3, 3′, 3″,3′″ is arranged exclusively in the abrasive-free layer 5 of the pellet 2, 2′,2″,2′″ and does not extend into its abrasive-containing layer 4. As a result, the abrasive-containing element 1, 1′, 1″, 1′″ can be used for machining of a part until all abrasive grains in the whole volume of the abrasive-containing layer 4 are utilized. The holding member 3, 3′, 3′″, 3′″ thus not only ensures a strong connection of the pellet 2, 2′,2′″,2″″ to the tool body, thus allowing a high-pressure high-speed machining of parts with an abrasive tool equipped with such abrasive-containing elements, but it also ensures a long service life of the abrasive-containing elements till the abrasive-containing layer 4 of its pellets is completely used, and thus the longer service life of the abrasive tool as a whole.
A holding member 3 is introduced into the mold, as well as mixtures with compositions to make an abrasive-free layer 5 and an abrasive-containing layer 4 into a thusly formed mold cavity. Then an upper mold part 14, or 14′, or 14″, depending on a desired shape of the abrasive-containing elements, is introduced into the opposite end of the mold. Under the action of correspondingly selected pressure and temperature, an abrasive-containing element according to the present invention is thusly produced. An abrasive-containing tool is produced by introducing a plurality of the thusly made abrasive-containing elements into a body of the tool with the use the their holding members.
The present invention is not limited to the details shown since various modifications and structural changes are possible without departing from the spirit of the present invention.