JPH0213573B2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method of manufacturing a dental bur.

(Prior Art) A dental bur is constructed by fixing abrasive grains to a base metal made of a thin rod. The shape of this base metal differs depending on the application, but for example, the base metal 11 shown in FIG.
Tapered part 1 whose diameter gradually decreases from the tip to the tip
3, and a spherical portion 14 formed at the tip of this tapered portion 13. A part of the spherical part 14 and the tapered part 13 becomes a cutting part 15, and abrasive grains 17 such as diamond grains are fixed thereto to enable cutting.

When manufacturing such a dental bur, base metal 1
After cleaning 1, a masking 16 (electrical insulating film) is applied. That is, a masking liquid such as resist ink or the like is applied to a portion of the shank portion 12 other than the root end portion 12a (which becomes a current-carrying portion in the plating process) and the cut portion 15, or a masking tape is wrapped around the portion.

Next, the current-carrying part 12a of the base metal 11 is sandwiched and supported by a jig 100 that also serves as one electrode, and the cutting part 15 is immersed in an electrolytic solution 101 (plating solution), and a large number of abrasive grains 17 are immersed in the cutting part 15. In this state, the other electrode plate 1 is placed on the cathode of the jig 100.
By connecting 02 to the anode and applying electricity, a metal plating layer is deposited on the cutting part 15, and
The abrasive grains 17 are fixed by this plating layer.

(Problems to be Solved by the Invention) In the above method, the base metal 11 is masked one by one, and the abrasive grains 17 are fixed to the base metal 11 one by one by the plating method. The sex was very bad.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and the gist thereof is to have a gripping shank part on the base side, and to cut from this shank part to the tip side. In a manufacturing method for a dental bur, in which abrasive grains are fixed to a thin bar-shaped base metal having a part by a plating method, the shank part of the plurality of base metals is supported by a jig that also serves as an electrode, and the jig is Electrical insulation is achieved by connecting the electric wires connected to the power supply, and immersing the parts of the base metal other than the cutting part and the jig in masking liquid with the shank part facing down and the cutting part facing up. Masking is applied to the base metal, and then the cut part of the base metal is immersed in the plating liquid with the shank part facing up and the cut part facing down, and is also immersed in a large number of abrasive grains. The method of manufacturing a dental bur is characterized in that a plating layer is deposited on the cutting part by applying electricity to the base metal through an electric wire and a jig, and the abrasive grains are fixed to the cutting part with the plating layer.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 5. Base metal 11 used in this example
are the same as the base metal 11 in FIG. 8, so the same numbers are given in the figure and detailed explanation thereof will be omitted.

In the figure, 20 is a jig. This jig 20 also serves as an electrode, and has a pair of metal support plates 21 and 22 as shown in FIG. 4. A crimp terminal 25 is fixed to one support plate 21 with a bolt 26, and an electric wire 27 is attached to this crimp terminal 25.
The ends of are connected. An insertion hole 21a is formed in one support plate 21, and a screw hole 22a is formed in the other support plate 22. Each support plate 21,
A large number of V-grooves 21b, 21b are formed on the opposing surfaces of 22, respectively.

With the shank portion 12 of the base metal 11 inserted into the V grooves 21b and 22b of the jig 20, the bolt 24
(FIG. 1, FIG. 2) is the insertion hole 21a of the support plate 21.
By inserting the support plate 21 and screwing it into the screw hole 22a of the other support plate 22, both the support plates 21 and 22 are connected, and the base metal 11 is supported. Note that the base metal 11 is cleaned before being supported by the jig 20. Further, the base metal 11 is supported so that all protruding lengths from the jig 20 are equal.

Next, masking processing is performed as shown in FIG. That is, masking liquid 31 is placed in tank 30.
to accommodate. Then, a large number of base metals 11 are supported by the jig 20 as described above, and the base metals 11 and the jig 20 are placed in the masking liquid 31 with the shank portion 12 facing down and the cutting portion 15 facing upward. Soak. At this time, the cutting portion 15 protrudes from the surface of the masking liquid 31. By pulling up the jig 20 and drying the masking liquid 31 adhering to the base metal 11, the masking 16 is applied to the base metal 11 except for the cut portion 15, as shown in FIG. 3a. Although not clearly shown in the figure, it goes without saying that the part of the shank portion 12 that is in contact with the jig 20 is not masked, and the jig 20 and the base metal 11 are in direct contact without the masking 16 interposed therebetween. The current state is maintained.

Next, as shown in FIG. 2, abrasive grains 17 such as diamond grains are fixed to the cut portion 15 by a plating method. That is, the tank 40 contains an electrolyte 41. An unglazed container 42 that is permeable to ions is housed in the tank 40, and the abrasive grains 1 are contained in the container 42.
7 is accommodated. Further, an electrode plate 45 is arranged inside the tank 40 . After the above masking process, with the large number of base metals 11 supported on the jig 20,
Place the shank portion 12 on top and the cutting portion 15 on the bottom.
Then, the tip side of the base metal 11 including the cutting part 15 is immersed in the electrolyte 41, and a large number of abrasive grains 17
bury it inside. In this state, the electric wire 27 connected to the jig 20 is connected to the cathode of the power source, and the electrode plate 4
Connect 5 to the anode and turn on electricity. As a result,
As shown in FIG. 3b, a plating layer is deposited on the cutting part 15 of the base metal 20, and the abrasive grains are separated by this plating layer.
7 is fixed. Note that even if immersed in the electrolytic solution 41, parts other than the cutting part 15 are masked 16.
is applied, so the precipitation of the plating layer and the abrasive grains 17
No fixation is performed.

When fixing the abrasive grains, the shank part 12 of the base metal 11
are securely fixed within the V-grooves 21b and 22b, and the contact between the jig 20 and the shank portion 12 is good. Therefore, there is no contact failure as in the conventional method shown in FIG. 8, and problems such as discoloration of a part of the shank portion 12 due to the heat caused by a large current flowing locally do not occur. Furthermore, even if the electrolyte splashes and adheres to the shank portion 12, the entire shank portion 12 is covered with the masking 16.
No plating layer is deposited. Note that the accuracy of the shank portion is extremely strict, approximately ±5 μm. This is because it is necessary that accidents do not occur even when rotating at high speed, and that it is necessary to easily attach and detach the handpiece and to be completely fixed to the handpiece that serves as the gripping portion of the rotating mechanism. Since the plating layer is not deposited on the shank portion 12 as described above, it is possible to prevent the shank portion 12 from becoming thicker, and there is no need to chemically polish or electrolytically polish the base metal 11 to remove the discolored portion or plating layer. This polishing can prevent the diameter of the shank portion 11 from becoming thinner. Therefore, the shank portion 12 can be made highly accurate.

Note that during the above-mentioned masking process, there are cases where the masking liquid 31 does not enter between the V grooves 21b and 22b of the jig 20 and the root side of the shank portion 12 is not masked. The electrolyte 41 dries at the openings at both ends of the V-grooves 21b and 22b, closing these openings or reducing the opening area, so even if the electrolyte 41 splashes, it can be reliably prevented from entering. can be prevented from precipitating.

After the abrasive grains 17 have been fixed, the masking 16 is removed by a known method to obtain a dental bur 10 as a final product, as shown in FIG. 3c.

The present invention is not limited to the above embodiments, and various embodiments are possible. For example, the shank portion 12 of the base metal 11
If the diameters of the V-grooves 21b and 22b are very slightly different from each other, by attaching conductive rubber to the inner surface of at least one of the V-grooves 21b and 22b, the slight difference in diameter can be absorbed and the support and contact of the shank portion 12 can be improved. It can be done better.

In addition, a normal dental bur has a cutting part extending a predetermined length from the tip of the base metal, and the same method as in the above-described embodiment can be used for manufacturing the bur. As a dental bur for special purposes, it is also possible to have a non-cutting part extending over a predetermined length from the tip and a cutting part between the non-cutting part and the shank part. The present invention can also be applied to the production of such special dental burs. That is, before or after the masking process as shown in FIG. 1, the uncut portion of the tip is masked. This masking process for the non-cutting parts can be done by immersing the non-cutting parts at the tips of the base metals in masking liquid while supporting a large number of base metals with a jig, or by painting them one by one with a brush, etc. You may. The other steps are the same as in the previous example.

Further, when performing base plating treatment before the abrasive grain fixing step, the base metal is immersed in an electrolytic solution in the same manner as in the abrasive grain fixing step.

FIGS. 6 and 7 show a jig 5 different from the above embodiment.
Indicates 0. This jig 50 has a support block 51 for supporting the base metal 11 and a guide plate 52 for guiding the base metal 11. These support plate 51 and guide plate 52 are connected by bolts 53. connected. A large number of elongated storage chambers 54 are formed in the support block 51, and both ends of the storage chambers 54 are open (the openings are designated by reference numerals 54a and 54b).
). Inside the storage chamber 54 is a conductive plate spring 55.
is formed. The leaf spring 55 has a base 55a disposed on one side of the opening 54a, and both side pieces 55b extending in the longitudinal direction of the storage chamber 54 from the base 55a. The base 55a has an opening 5.
An electric wire 57 inserted from 4a is soldered. The leaf spring 55 is connected to the cathode of a power source via this electric wire 57. On the other hand, a guide hole 58 is formed in the guide plate 52, and this guide hole 58 communicates with the storage chamber 54 via an opening 54b. The guide hole 58 is approximately equal in diameter to the shank portion 12 of the base metal 11. and,
The shank portion 12 of the base metal 11 is inserted through the guide hole 58 and press-fitted between the both side pieces 55b of the leaf spring 55. Thereby, the base metal 11 is supported. At this time, the shank portion 12 is positioned against the base portion 55a of the leaf spring 55, and is supported by the guide hole 58 without lateral vibration. In this example,
The root side of the shank portion 12 is not masked.

(Effects of the Invention) As explained above, in the method of the present invention, a large number of base metals are supported by a jig to which electric wires are connected, and are immersed in a masking liquid except for the cut portion on the tip side, and then The cut part is immersed in the abrasive grains while being immersed in the plating liquid in the opposite direction, and electricity is applied to the base metal through the electric wire and jig to deposit a plating layer on the cut part, and this plating layer is used to polish the abrasive. Since the grains are fixed to the cutting part, not only can multiple base metals be masked at once, but
Abrasive grains can be fixed to multiple cutting parts at once. Moreover, the masking process and the abrasive grain fixing process can be performed continuously without attaching or detaching the base metal using a jig between these two processes. Therefore, the productivity of dental burs can be significantly improved.

[Brief explanation of drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is a diagram showing a masking process, FIG. 2 is a diagram showing a process of fixing abrasive grains to a base metal by electroplating, 3A to 3C are diagrams explaining the state of the base metal in order, FIG. 4 is an exploded perspective view of the jig, and FIG. 5 is an enlarged sectional view showing the state of support of the base metal by the jig,
FIG. 6 is a perspective view showing another aspect of the jig, FIG. 7 is a sectional view thereof, and FIG. 8 is a diagram showing a process of fixing abrasive grains by a conventional method. 10...Dental bur, 11...Base metal, 12...
shank part, 15... cutting part, 16... masking, 17... abrasive grain, 20, 50... jig, 27,
57... Electric wire, 31... Masking liquid, 41...
Electrolyte solution (Metsuki solution).

Claims (1)

[Claims] 1. In a method for manufacturing a dental bur, in which abrasive grains are fixed by a plating method to a thin bar-shaped base metal having a shank part for gripping on the base side and a cutting part on the tip side of the shank part, a plurality of Support the shank part of the base metal with a jig that also serves as an electrode, and connect the electric wire connected to the power supply to the jig. Apply masking to the base metal for electrical insulation by immersing the parts other than the cut part and the jig in masking liquid. Next, place the base metal with the shank part facing up and the cutting part facing down. While the cut part is immersed in the plating liquid and buried in a large number of abrasive grains, electricity is applied to the base metal through the electric wire and jig to deposit a plating layer on the cut part, and this plating layer is used to polish the abrasive. A method for manufacturing a dental bur, characterized by fixing grains to a cutting part.