JPS60129042A - Production of dental reamer or file - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a dental reamer or file with good sharpness, which is used for cleaning the root canal of a tooth and has a blade shape that has a larger rake angle than the conventional one and a smaller relief angle than the conventional one. Regarding the manufacturing method.

Dental reamers or files (hereinafter referred to as reamers) are:
As shown in Figure 1(a), the rotation (3a) is used to remove unfavorable factors from within the root canal of tooth 1 and at the same time smooth the root canal wall. Rotation direction when using a reamer) It has the function of cutting the root canal wall 2 by pushing and pulling and enlarging the root canal. In other words, the reamer not only has a good sharpness that allows the root canal to be enlarged smoothly in a short time, but also is strong enough to prevent it from bending into the root canal, and can withstand chemical solutions, dry heat, and disinfection. Austenitic stainless steel is generally used in cases where high corrosion resistance is particularly required. Usually, the cross section of the blade part is triangular or square as shown in FIGS. 1(b) and 1(c), and the blade is formed into a spiral strip as shown in FIG. 1(0)3. Incidentally, the rake angles of these reamers are both negative, with the former being 130 degrees and the latter being 45 degrees.

On the other hand, in general cutting, it is known that in order to improve the sharpness of a cutting tool against a workpiece, the rake angle is positive. Therefore, in the case of the above-mentioned dental reamer, if the rake angle is set in the positive direction, the root canal wall of the tooth can be cut with good cutting ability. However, when cutting and enlarging the root canal wall with a reamer, it is necessary to ensure that the reamer does not break during cutting.To do this, it is necessary to make the cross-sectional area of the reamer too small and to make the reamer itself too hard. Excessive amounts must be avoided as much as possible.

In order to solve the above-mentioned demands, the present applicant first devised a dental reamer having a larger rake angle and a smaller clearance angle than the conventional one, and filed an application (Utility Application No. 55-114025).
issue). Fig. 2 (b) and Fig. 3 (b) are cross-sectional views of the blade of Isono's dental reamer, in which polygon abc in Fig. 2 (b) and polygon abed in Fig. 3 (b) are shown. This corresponds to its cross-sectional shape.

The present invention was made to manufacture an improved dental reamer as described above, and firstly, a reamer! The applicant's patent 115293 applies to the material (straight round wire or square wire, etc.)
8 (Japanese Patent Publication No. 57-43386), the finished product has a triangular or square cross section with a shaft diameter larger by the amount of crushing and smaller shaft diameter than the final shaft diameter, and a predetermined shape. forming a columnar body having a longitudinal shape;
Next, the reamer or A method of manufacturing a dental reamer or file having a predetermined tip angle and a predetermined shaft diameter, and a large rake angle (compared to conventional methods) and a small clearance angle compared to conventional methods, by crushing the cutting edge corner of the file. This is what we provide.

Hereinafter, the present invention will be described with reference to examples.

FIG. 2 is a diagram showing an embodiment of the present invention, and shows a method of manufacturing a reamer from a columnar body having a triangular cross section.

FIG. 5(a) is a side view showing a state in which a columnar body is processed by a processing die, and FIG. 2(b) and FIG. In the same figure (a),
Reference numeral 4 denotes a columnar body having a triangular cross section and having a predetermined longitudinal shape, which is ground slightly larger by the amount of crushing and making it smaller than the shaft diameter of the finished reamer, and is usually made of austenitic stainless steel.

Reference numeral 5 denotes a single frame-shaped processing mold, which is installed at a fixed position. Reference numeral 5a denotes a square processing section, in which the columnar body 4 is subjected to a desired processing. Therefore, a material with high hardness and wear resistance is desirable. In the figure (b), ΔA'B'C' corresponds to this. 5b is a circular hole through which the columnar body 4 can pass. Reference numeral 6 denotes a holder that firmly holds the end portion 4a of the columnar body 4, and allows it to be forcibly rotated in a certain direction 6a and moved by being pulled in a direction 6b (path shown).

Now, with the end 4a of the columnar body 4 firmly held in the holder 6 and the columnar body 4 inserted into the processing mold 5 as shown in FIG. Move it by towing it in the direction 6b. Then, in the circular hole 5b of the processing die 50, the columnar body 4 rotates without receiving any resistance.
In the square processing portion 5a (△A'B'C'), the cutting edge corner A of the columnar body 4.

B and C are each pressed in a direction opposite to the rotational direction of the machining reservoir (opposite to the rotational direction when using a reamer) and are crushed and twisted, forming a cross section of polygon abC in the figure (b). That is, the flanks of the cutting edge corners A, B, and C are bent outward (or curved depending on the tool) near the cutting edge corners, and the scooping surfaces are curved inward near the cutting edge corners. Here, the double length of the line segment 6 connecting the center O of the columnar body and the corner a is the predetermined shaft diameter (circumscribed circle diameter) of the reamer.

Incidentally, in this case, the scooping angle 10ad is naturally larger than the conventional negative scooping angle 30 degrees. Since the rake angles mentioned above all have negative values, the rake angle of reamer abc is larger than that of conventional products, and as a result, chips flow out easily υ
, the cutting resistance is reduced and the root canal wall 2 can be cut well. In addition, if the amount of crushing is to be extremely large, the rake angle can be set to a positive value, but experiments have shown that a positive rake angle has the disadvantage of digging into the root canal wall too much.

In this example, the size of the machining angle A'B'C' for the columnar body ABC is set so that the scooping angle o a d is approximately 10 degrees and the clearance angle LB'af is approximately 40 degrees. For example, the cutting edge angle d a B' is LOa d + L Oa B' = 10° + 50° - 6
At 0°, the angle of the cutting edge is the same as that of conventional products, but since the shape angle is suitable for receiving force, the strength of the cutting edge becomes that much stronger. Coupled with the increase in hardness due to work hardening of the corner of the cutting edge, cutting of the root canal wall becomes even better. At this time, work hardening occurs only at the corner of the cutting edge, and the center of the reamer is hardly work hardened as in conventional reamers, so the reamer itself does not lose its flexibility and toughness, and only the corner of the cutting edge has strength and strength. surface] resulting in increased durability.

The above-mentioned effects can be exerted on the entire reamer by moving the columnar body 4.

Next, FIG. 3 is a diagram showing another embodiment of the present invention, showing a method of manufacturing an improved reamer from a columnar body having a square cross section. Figure 3(a) is a side view corresponding to Figure 2(a), Figure 3(b) is a side view corresponding to Figure 2(b), and Figure 3(→ corresponds to Figure 2(c)). This figure is different from the case shown in Figure 2.The columnar body 4' has a square cross section, the square processing part of the processing mold 5' has a square shape, and the opening A'B'C'D' (see figure (b)) corresponds to this.

In this embodiment as well, as in the case of FIG. 2, FIG.
, ), when the holder 6 is rotated in a certain direction 6a and pulled and moved in the direction 6b, the corner ends A, B, C, and D of the columnar body 4' are moved in the opposite direction to the rotation direction. The polygon ab in the figure (b)
Form a cross section of cd. That is, the flanks of the corner ends A, B, C, and D are bent outward near the corner of the cutting edge, and the scooping surfaces are curved inward at the corner of the cutting edge. Here, ac, l) d is the predetermined shaft diameter (circumscribed circle diameter) of the beam.

Incidentally, in this case, the rake angle ffoae allows better cutting of the tree and the root canal wall 2 compared to the conventional one.

In this embodiment, the scooping corner 0ae is approximately 25 degrees, and the clearance corner B'
If machining type A'B'C'D' is selected for the columnar body ABCD such that af is approximately 25 degrees, the cutting edge angle L e a B' will be L 0ae-14Qa13' = 25° + 65° - 900
Although it is no different from the conventional product, the effect can be enjoyed in the same way as in the case of FIG. Further, the above-mentioned effect can be applied not only to the movement of the columnar body 4 but also to the entire reamer, as in the case of FIG. 2.

The above-mentioned embodiment shows a case in which the processing mold is formed as a single body, and a processing mold is used in which a square processing part for processing the columnar body is provided above a circular hole through which the columnar body can pass. This will be referred to as the first embodiment.

Based on this first embodiment, ■2/1o of the draft S0 standard.

In order to make a No. 100 basic cross-section triangular reamer with a 16wn cutting edge in Theno and -, we experimented with a type with a triangular corrugated part with a circumscribed circle diameter of 1.6 mm, and found that the beginning of the twist was as follows.
In order to finish the diameter to 1.32mm, it is appropriate to make a triangular shape with a circumscribed circle diameter of 1.34mm, and for the end part of the screw, to finish the diameter to 1.00mm, it is appropriate to use a triangular columnar body with a diameter of 1.06mm. When this was formed by grinding and then twisted, the rake angle was approximately -21° at the beginning of the twist as shown in Fig. 2 (d)), and the rake angle was approximately -21° at the end of the twist. Figure 2 of about 00 (,
).

In this way, in the single processing type, the rake angle and clearance angle change depending on the change in diameter from the beginning of the twist to the end of the twist. Furthermore, for example, a thin No. 30 gluer with a taper of 2/100,
The length of 16 mm is 0.62 mm in diameter at the beginning of the twist.
Even if it is processed using a mold with a triangular torsion part of the circumscribed circle having the same diameter as , the inscribed circle of this mold is 0.62 sin 30° = 0
．． The length is 31 mm, and 0830 at the end of the twisting shaft rotates freely and cannot be twisted. In other words, in order to insert a columnar body, it is necessary that the diameter of the circumscribed circle of the machining mold similar to the cross section of the columnar body be larger than that of the finished reamer, and in order to twist it, the diameter of the inscribed circle must be smaller than the diameter of the finished reamer. B. With the unitary processing type, it is not possible to process the twist start portion and twist end portion of No. 30 because there is no mold that satisfies this condition. By the way, regarding the above circumscribed circle and inscribed circle,
In the case of a rectangular cross section, the former is the smallest of the circles that pass through at least three vertices, and the latter is the largest of the circles that touch at least three sides.

Therefore, when the machining die is made up of multiple tools, the size of the machining die is regulated by the copying die, and the size of the machining die and the movement position of the columnar body are kept in a constant relationship, the second An example will be described.

Figure 4 is a diagram showing one embodiment of the above, and shows a method for manufacturing an improved columnar body from a columnar body having a triangular cross section. Part plan view, (C)
FIG. 2 is a plan view showing a processing die.

In FIG. 4A, reference numeral 4 denotes the previously described columnar body having a triangular cross section, the end of which is firmly held by a holder 6.

Reference numeral 7 denotes a movable body, on which a holder 6 is forcibly rotatable (not shown) and a copying die 8 is fixedly installed. The moving body 7 is movable in a direction perpendicular to the base 22 (not shown). One surface of the copying hood 8 is in contact with an adjustable stroke 2 nog 11, and the other surface 8a is in contact with a tip 9a of a piston 9 that fits into a cylinder 10. When the copying die 8, which is rotatably attached to the base 22 by a shaft 10a, moves, the piston tip 9a is displaced by the surface 8a, and this displacement passes through the lever 14 and the lever 13 to the processing die tool 1.
2a. Piston 9 and lever 14 are connected to shaft 14a
The lever 14 and the lever 13 are rotatably connected to a shaft 15. Furthermore, the lever 14 is rotatably mounted to a shaft 19'.

The surface 8a of the copying die 8 is determined based on the taper of the reamer. The machining die 12 consists of tools 12a, 12b, and 12c (see the same figure).
The tool 12b is attached to the lever 16, and the tool 12e is attached to the lever 18.
The lever 16 is fixed to the base 22 by a bolt 17, and the lever 18 is rotatably attached to the base 22 by a shaft 19. Also, Reno-13 and 18 have spring 20
It is being towed by J21.

By the way, the tool 12b of the processing die 12 is fixed to the base 22 by the renocouple 16. The tool 12a is the lever 13
Since the piston 9 is connected to the piston 9 by the lever 14, the reamer chi/? When the tool 12a is given a displacement such that In this case, the tool 12a performs a lateral displacement in the same way as the vertical displacement a, but these are caused by the oscillation of the lever 13 with the shaft 15 as a fulcrum and the restraint by the spring 20.
It is possible to move from the position -1 (solid line) to the position 12a-2 (dotted line) without any problem. In this case, the tool 12C moves from a position of 912 cm1 (solid line) to 12 cm2 (
(dotted line) by a displacement a. In reality, 12C
Since point B' also moves somewhat due to the neck of
6. It is better to install it in the same way as in 18. In this way, the processing die 12 can always maintain the required size that matches the reamer's chi. Tool 12 here!
, 12b.

Due to the movement of 12C, △A'B'C' (Fig. 2 (
This corresponds to △A'pc in b). ) to △'1B'C'1 and the center of the potting mold will shift, but since the displacement due to the betenok is small compared to the length of the columnar body, there will be no problem on the solid line. .

Next, the operation of this embodiment will be described. First, the position of the copying die 8 and the size of the processing die 12 are adjusted to a predetermined relationship, and the columnar body 4 is attached to the holder 6. Next, move the holder 6 in a predetermined direction 6.
Forced rotation is given to a, and the moving body 7 is moved in the direction of 6b. Then, the copying die 8 applies a displacement to the piston tip 9a in accordance with the tenor 9 of the reamer and the necessary amount of cutting edge crushing. In response to this, lever 14 and lever 13 actuate tool 1.
The required displacement is transmitted to 2a. Further, the tool 12c is displaced in accordance with the displacement of the tool iza, and the processing mold 12 is formed into a required size.

Due to the above-mentioned action, the columnar body 4 is always subjected to p-processing using the processing die 12 of an appropriate size. As a result, it is possible to obtain a reamer having a larger rake angle and a smaller clearance angle than the conventional reamer as described in the case of FIG. Furthermore, in the case of this embodiment, compared to the case where the single-piece processing die described above was used, the finishing series reamer's chi/? It is possible to carry out machining that is more in accordance with changes in the shaft diameter due to the change in shaft diameter, and the effects of the present invention can be enjoyed even more markedly.

FIG. 5 is a diagram showing another embodiment, showing a method for manufacturing a lumber from a columnar body with a rectangular cross section, in which (a) is a side view of the main part, and (b) is a plan view of the main part. , (C) is a plan view showing the processing die.

As is clear from the drawing, in the case of a rectangular cross section, the number of tools for the machining die 12' is four (see figure (C)), and in tool adjustment, the tool 12'b is fixed, the tool 12'e is moved laterally, and the tool 12'e is moved laterally. In addition to the vertical and horizontal movement of the tool 12'a, the tool 12'd also needs to be moved vertically. Therefore, in addition to the adjustment system of the tool 12'a using the copying die 8, the piston 9, the levers 14, 13, etc., the copying die 8', the piston 9', the lever 14',
An adjustment system for tool 12'd using 13' etc. was provided ((b
) see figure). The operation is almost the same as in the case described above. Also in the case of this embodiment, the same operation and effect as in the case of FIG. 4 can be enjoyed.

In the description of the above embodiment and FIGS. 4 and 5, the tool was expanded and contracted by the oscillation υ method to form a triangular or quadrangular machining area. For example, in FIG. 4(C), the tool 12a is A'
In the B' force direction, the tool 12e can also be configured to move in parallel in the C'B' direction.

The first embodiment uses the unitary processing mold shown in FIGS. 2 and 3, and the copying mold 8 shown in FIGS. 4 and 5 is used to expand and contract the processing mold according to the position in the length direction of the columnar body. In contrast to the second embodiment shown below, the third embodiment shown below is an example in which the size of the processing die is expanded and contracted in accordance with the cross-sectional size of the twisted portion of the columnar body, and specifically, As shown in FIG. 6(a), there is a measuring part 121L-A protruding from the tip of the tool and a processing part 12a.
-B is provided, and the measurement part 12a-A measures the size of the columnar body in the twisted part (distance from the center to the side), and the processing part 12a-B, which is a certain dimension larger than this, is near the cutting edge of the surface that will become the flank surface. This is an embodiment in which the corner portion of the cutting edge is crushed and twisted by applying a twisting force to the cutting edge. That is, at the tip of each tool 12a, 12b, etc. of the divided processing die,
A measuring section A1 and a processing section B are provided.
This is an example of manufacturing a reamer with improved rake angle and clearance angle as described above by gripping a columnar body as shown in b) and twisting it in the state shown in Fig. 6 (,) formed by the processing section at that time. . The feature of this third embodiment is that it is possible to easily form a processed portion that follows the size of the columnar body without using a separate copying die. In other words, the third embodiment uses a mold that is a certain dimension larger than the size of the columnar body, and is not a certain proportion larger, so it is not the single body processing S-t'zF & end of the first embodiment, but it is the same as the original one. The improvement in scooping angle relief angle is small in the thick part, and the improvement is large in the tapered part. In the above explanation and FIG. 6, the processing mold for the size of the columnar body is formed by the step between the measuring part A and the processing part B of the processing mold, but the measuring part can be used as an electrical or photoelectric sensor part. Of course, it is also possible to embed a sensor in the processing section itself and determine the size of the processing section based on the sensing of this sensor section.

In this case, there is no longer a limitation that the processed portion is a certain size larger than the size of the columnar body.

The present invention has the above-mentioned configuration, operation and effect, and first grinds a columnar body having a cross section larger than the finished series reamer shaft diameter by the amount of crushing and making it smaller, and having a predetermined lengthwise shape. The columnar body is formed into a polygon by processing, etc., and then the columnar body is pulled and moved by rotating the inner side of the processing die that forms the square shape provided at a certain position. A torsional force is applied only near the cutting edge on the surface that becomes the flank to crush the corner of the cutting edge, and it has a predetermined taper and a predetermined shaft diameter, and the rake angle is larger than before, and the clearance angle is smaller than before. Dental reamers or files can be manufactured. In addition, when using a single processing die, the purpose can be achieved with a relatively simple device, and when using a processing die consisting of multiple tools, the shaft diameter can be achieved by adjusting the finish reamer or file taper. It is possible to perform processing that is more in line with changes in the temperature, and is expected to have the effect of being able to manufacture reamers or files with higher precision.

Furthermore, it is manufactured using a single-piece processing die of the first embodiment and a processing die of a fixed size larger than the size of the columnar body of the twisting portion shown in FIG. 6 of the third embodiment. A reamer with a small root part and a large tip part with improved scooping angle and relief angle has a reamer blade length of 16 pieces, but is mainly used with only a sharp tip, so it scoops the entire surface evenly. It can be used in the same way as a reamer or file to improve the relief angle, and in cases where you want to cut the original material (such as the so-called avical sheet type pear ridge, which is a reamer with a cutting edge only at the tip). , it has characteristics that are more effective than those that are uniformly improved as a whole. In addition, the processing die that is expanded and contracted by the copying die 8 of the second embodiment can be adjusted by adjusting the copying die 8.
It is possible to manufacture the same product as in the third embodiment, and conversely, by greatly improving the scooping angle relief angle of the original thick part and reducing the improvement of the tip, the root canal near the apex can be made softer.
It is also possible to manufacture a special file for the purpose of mainly shaving the flared part without shaving it.

The above explanation has mainly been about improving the rake angle relief angle in rotary cutting, ie, reaming, but the rake angle relief angle in push-pull cutting, ie, filing, is an angle in the longitudinal section. FIG. 7 is a longitudinal section of a reamer and file made from a columnar body with a triangular cross section.

FIG. 7(a) shows a conventional reamer and FIG. 7(b) shows a reamer having an improved rake angle and clearance angle manufactured by the method of the present invention.

As an example of a file, the scooping angle is 110° and the conventional product is -30°.
200% improvement over °. That is, the present invention is also effective in filing.

Furthermore, as shown in Fig. 8 (,), by twisting a columnar body with an equilateral triangular cross section using a right triangular processing die with one angle of 60°, the two cutting edges can be twisted in the same manner as when twisted using an equilateral triangular processing die. It is also possible to set the rake angle and relief angle, and the other cutting edge to have a rake angle and relief angle different from the other two cutting edges. Further, as shown in FIG. 8(b), by twisting a columnar body having a rhombic cross section using a non-diamond-shaped parallelogram processing die, it is possible to improve the rake angle clearance angle of only the two cutting edges. That is, by twisting a cross-sectional shape similar to the cross-sectional shape of a columnar body using a gouging die, it is possible to manufacture a reamer or file having the respective characteristics.Of course, the columnar body is limited to equilateral triangles and squares. figure,
It may be an isosceles triangle, a rhombus, a rectangle, or a polygon with a partially curved line. This is possible regardless of whether it is a single piece or a telescoping type.

[Brief explanation of the drawing]

Figure 1 shows a conventional dental reamer; (a) is a front view, (b) and (c) are cross-sectional views, and (b) is a triangular cross-section.
c) shows the case of a rectangular cross section. 2 and 3 are diagrams showing the case where a single-piece processing mold, which is an embodiment of the present invention, is used, respectively. FIG. 2 is a diagram illustrating a method for manufacturing the same, in which (a) is a side view, (b) is a cross-section AA in (a), and (C) is a cross-section BB in (,). FIG. 4 and FIG. 5 are diagrams each showing another embodiment of the present invention in which a processing die that expands and contracts in accordance with the position in the length direction of a columnar body made up of a plurality of tools is used. is a cross-sectional triangle,
FIG. 5 is a diagram showing a method of manufacturing a dental reamer from a columnar body with a square cross section, and in both figures (a) is a side view of the main part ((
(b) is a plan view of the main part, and (C) is an enlarged plan view of the processing mold. Figure 6 shows an embodiment of the pond according to the present invention, in which a processing mold corresponding to the size of the twisted part of the columnar body is used, (a) is a front view thereof, and (b) is a measurement part. , and is a sectional view taken along line A-A in FIG. Also (C
) The figure shows the processed part, and is a sectional view taken along line BB in figure (a). FIG. 7 shows a reamer manufactured by the method according to the present invention. Vertical cross-sectional views of files, (a) is the conventional example, (
b) was produced by the method of the present invention. FIG. 8 is a diagram showing an embodiment in which the processing mold has a cross-sectional shape similar to that of the columnar body, and (a) shows an equilateral triangular columnar body with an angle of 60°.
(b) is a diagram showing a diamond-shaped columnar body processed using a non-diamond-shaped parallelogram type to improve the rake angle and relief angle of the two cutting edges. 4.4'...Columnar body, 5, 5'...Processing mold, 6.
... Holder, 7... Moving body, 8, 8'... Copying type,
9, 9'... Piston, 11... Stopper, 12
, l 2'... processing type, 13.13'. 14, 14', 16, 18... lever, 20, 2
1゜21'...Spring, 22...Base. Patent Applicant Matsutani Manufacturing Co., Ltd. Agent Takao Suzuki Figure 1 Figure 2 B Figure 3 B-J A-I Figure 6 Figure 7

Claims (1)

[Scope of Claims] (1) It has a triangular or quadrangular cross section with a shaft diameter that is larger by the amount that the shaft diameter of the finished series reamer or file is crushed and becomes smaller, and has a predetermined longitudinal shape. The finishing JIJ-ma or For processing molds that are larger than the file shaft diameter and whose diameter of the inscribed circle (in the case of a square, the largest of the circles touching at least three sides) is smaller than the finishing series or file shaft diameter, the inside A method for manufacturing a dental reamer or file having a larger rake angle and a smaller relief angle than conventional methods, characterized by twisting the cutting edge while rotating it while continuously crushing the corner part. /2) The processing die has a similar shape or a dissimilar shape to the cross-sectional shape of the columnar body. A method for manufacturing a dental reamer or file according to claim 1, characterized in that: (3) The method for manufacturing a dental tool or file according to claim 2, wherein the processing mold is made of a single piece. (4) A dental reamer according to claim 2, wherein the processing mold is expandable and contractible, and expands and contracts in accordance with the position of the columnar body in the longitudinal direction; How the file is manufactured. (5) The processing mold is expandable and contractible, and the processing mold expands and contracts to a size corresponding to the cross-sectional size of the columnar body in the twisted portion. A method of manufacturing a dental reamer or file.