JP2005081468A - Broaching method and composite internal broaching tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a broaching method and a composite internal broaching tool at a low cost, including a cutting blade having a flank without a straight land used in finishing a high-hardness material having a hardness of 45 to 65 HRC, and compensating dimensions of the cutting blade decreased by re-grinding the flank of the cutting blade. <P>SOLUTION: In this broaching method, first blade groups 5, 6 and 7 having a cutting blade including final finishing size blades 15, 16 are planted in a plurality of grooves 2, 3 and 4 formed extending in the longitudinal direction in the circumference of a shaft 50 of a bar-like broaching tool body 1, and second blade groups 52, 53 and 54 having at least one or more final finishing size blades 20, 21 are provided in the rear of the first blade group after re-grinding, thereby broaching. This composite internal broaching tool 55 is used in the broaching method. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a broaching method and an assembly-type inner surface broach tool used for machining internal gears, spline grooves, ball spline grooves, etc., and in particular, a broach tool in which a blade group having cutting edges is implanted on the shaft of the broach body The present invention relates to a broaching method and an assembly type internal broach tool.

Conventional assembly type internal broaching tools are used for broaching of large-diameter internal gears, etc. Among these broaching tools, blade-type tools are used for finishing in grooves 31 provided in the main body 30 as shown in FIG. There is a structure in which a blade 33 having a blade 32 is fitted and fixed by a set bolt 34 (for example, Patent Document 1). In such a finishing broach cutting edge, a straight land 38 having a clearance angle of 0 ° is provided between a rake face 36 and a clearance face 37 of the cutting edge 35 as shown in FIG. 2). As a result, when the cutting edge 35 is worn out, the rake face 36 is reground, and even if the rake face 36 is retracted to the position of the rake face 39 indicated by a dotted line, the machining dimension change is within the range of the straight land 38. I can not. However, when broaching a high hardness material with a hardness of 45 to 65 HRC (Rockwell hardness C scale), if the straight land 38 is attached with a clearance angle of 0 ° as shown in FIG. 11, the rubbing at the straight land portion is abnormal. Since the roughness of the processed surface is deteriorated, the straight land 38 cannot be attached. Therefore, when machining a hard material, the flank 41 of the finishing broach cutting edge 40 as shown in FIG. 8 has no straight land, that is, the flank 41 of the cutting edge 40 is formed with an inclined surface having a clearance angle β. A broaching tool is used.
Japanese Utility Model Publication No. 1-12904 Japanese Utility Model Publication No. 57-57876

  However, if the rake face 42 is reground when the cutting edge 40 is worn and the rake face 42 is retracted to the position of the rake face 43 indicated by a dotted line, the workpiece is reduced by the amount indicated by b. If the dimensional tolerance width of the product is small, there is a problem that the number of regrinds is small. In particular, when an expensive material such as cemented carbide or CBN is used for the blade material, there is a serious problem in terms of cost.

  An object of the present invention is to solve such problems of the prior art, and includes a cutting edge having a flank without a straight land used for finishing a hard material having a hardness of 45 to 65 HRC. An object of the present invention is to provide a broaching method and an assembled inner surface broach that can compensate for the reduced cutting edge size by regrinding the rake face of the cutting edge in an assembled inner surface broach tool at a low cost.

  In the present invention, it is a processing method for finishing a high hardness material having a hardness of 45 to 65 HRC, and a plurality of grooves formed to extend in the longitudinal direction on the circumference of a shaft of a rod-shaped broach tool body. A first blade group having a cutting edge including a final finishing dimension blade is implanted, and a second blade group having at least one final finishing dimension blade is provided at the rear of the first blade group after re-grinding. Thus, the above-described problem has been solved by providing a broaching method for performing broaching. That is, the first blade group having the final finished dimension blade is implanted in the broach body, and after a certain amount of machining, the rake face of the worn cutting edge is reground. However, since the flank face of the cutting edge has a structure without a straight land, the broach cutting edge size is negative. At this time, if the dimension of the workpiece is out of the range of the product tolerance, the broach life is reached. However, in the present invention, the first blade group is not discarded at this point, and a new one is added behind the first blade group. A second blade group having a final finished dimension blade is installed to enable continuous machining. If the second blade group is not used when the first blade group is new, there is no risk of scratching the cutting edge due to rubbing or the like. Further, when an expensive cemented carbide or CBN is used for the first and second blade group materials, the cost merit by increasing the number of re-grinding is particularly great. In addition, in the text, there is a description of the front part, the rear part, or the front and the rear with respect to the broach tool or the blade group. However, all of these notations have the front or front as the broach cutting direction and the rear side or the rear as the opposite side.

  In addition, a broach which is provided with a spacer having the same longitudinal length as that of the second blade group at the rear portion of the first blade group before regrinding and which replaces the spacer with the second blade group after regrinding the first blade group. A processing method was defined (claim 2). That is, when the broach is new, the second blade group is not used, and instead, a spacer having the same longitudinal length is provided behind the first blade group for processing. After a certain amount of machining, when the wear part of the cutting edge is reground, the first blade group is not discarded when the broach cutting edge dimension is out of the product tolerance range and the broach life is reached. The spacer at the rear of the same row of the blade group is replaced with the second blade group to allow continuous machining. Since the second blade group is not used when the first blade group is new, there is no fear of scratching the cutting edge due to rubbing or the like.

  In addition, after regrinding the first blade group, the segment in front of the first blade group that has been divided or divided into at least two segments in the longitudinal direction is discarded, and the rear of the first blade group is discarded. A broaching method is provided in which the second blade group is provided at the rear of the segment. That is, when the broach is new, the second blade group is not used, but after re-grinding the cutting edge, the front segment of the segment divided into two or more is discarded, and the final finish is newly added to the rear of the rear segment. A second blade group having a dimension blade is installed.

  More preferably, the broaching method is such that the longitudinal length of the front segment is the same as the longitudinal length of the second blade group. As a result, since the longitudinal length of the second blade group newly installed in the broach body at the rear part of the front segment and the rear segment which are no longer necessary is the same, What is necessary is just to provide a 2nd blade group in the rear part of a back segment.

  Furthermore, the broach tool used in the broaching method described above is implanted in a rod-shaped broach tool body and a plurality of grooves formed to extend in the longitudinal direction on the circumference of the axis of the broach tool body, and is reground. Assembly type internal broaching tool for finishing a high-hardness material having a hardness of 45 to 65 HRC, comprising a first blade group having a sharp cutting edge and a second blade group provided at the rear of the first blade group And it was set as the assembly-type inner surface broach tool used for the broach processing method as described in any one of Claim 1 thru | or 4 mentioned above (Claim 5). In other words, even if the final cutting edge size of the first blade group is negative enough to deviate from the product tolerance due to regrinding, the second blade group having the final finishing dimension blade is newly installed, so that it is processed to a predetermined size. The

  More specifically, a first broaching tool body having a rod-like broaching tool main body and a plurality of grooves formed so as to extend in the longitudinal direction on the circumference of the axis of the broaching tool main body and reground. An assembly-type inner surface broaching tool for finishing a high-hardness material having a hardness of 45 to 65 HRC, comprising: a blade group; and a second blade group provided at the rear of the first blade group, wherein the second blade The group is an assembly type internal broach tool having at least one or more final finished size blades (Claim 6).

  The second blade group is an assembly-type inner surface broach tool having at least one adjustment blade in front of the final finish size blade. In other words, the effect of the final cutting edge size of the first blade group after re-grinding is eliminated by providing an adjusting blade in front of the final finishing size blade of the second blade group in which cutting edges are arranged in order of dimensions. .

  Further, the material of the first blade group and the second blade group is cemented carbide or CBN (claim 8). Thereby, it becomes more suitable for the finish broaching of a hard material.

  As described above, according to the present invention, it is a processing method for finishing a high-hardness material having a hardness of 45 to 65 HRC, and is formed to extend in the longitudinal direction on the circumference of the shaft of the rod-shaped broach tool body. A first blade group having a cutting edge including a final finishing dimension blade in a plurality of grooves, and a second blade having at least one final finishing dimension blade at the rear of the first blade group after re-grinding. This is a broaching method in which a group of blades is provided to perform broaching, thus providing a low-cost broaching method that can compensate for the reduced cutting edge size by regrinding the rake face of the cutting edge without straight lands. (Claim 1).

  In addition, a broach which is provided with a spacer having the same longitudinal length as that of the second blade group at the rear portion of the first blade group before regrinding and which replaces the spacer with the second blade group after regrinding the first blade group. Since the processing method is adopted, the first blade group is not discarded, and a second blade group having a final finish dimension blade is newly installed behind the first blade group to enable continuous processing. As a result, the service life can be extended and the blade group having cutting edges can be made cheaper than a new work. Further, since the second blade group is not used when the first blade group is new, it is not necessary to worry that the cutting blade is damaged by rubbing or the like (claim 2).

  In addition, after regrinding the first blade group, the segment in front of the first blade group that has been divided or divided into at least two segments in the longitudinal direction is discarded, and the rear of the first blade group is discarded. Since the broaching method is to provide the second blade group at the rear of the segment, the second blade group is not used when the broach is new. After re-grinding the cutting edge, it is divided into two or more to shorten the cutting edge life. The reached front segment is discarded, and the second blade group having a shorter length in the longitudinal direction than the first blade group is installed at the rear of the rear segment, so that it can be processed to a predetermined size. In addition, it is less expensive than the new first blade group.

  In addition, since the broaching method in which the longitudinal length of the front segment is the same as the longitudinal length of the second blade group is used, the second blade group is disposed on the rear portion of the rear segment as it is after the front segment is discarded. The number of teeth of the broach after re-grinding, the entire length of the cutting edge, and the position can be made the same and stable machining can be performed, and the reassembly work is facilitated.

  A first blade group having a rod-shaped broach tool body, a first blade group having cutting edges implanted and reground in a plurality of grooves formed to extend in the longitudinal direction on the circumference of the axis of the broach tool body; An assembly type internal broaching tool for finishing a high hardness material having a hardness of 45 to 65 HRC, comprising: a second blade group provided at the rear of the first blade group; Since it is an assembly-type inner surface broach tool used in any one of the broaching methods, even if the final cutting edge dimension of the first blade group is deviated to the extent that it deviates from the product tolerance by re-grinding, a new final finishing dimension is newly created. Since the second blade group having blades is installed, it can be processed into a predetermined dimension.

  A first blade group having a rod-shaped broach tool body, a first blade group having cutting edges implanted and reground in a plurality of grooves formed to extend in the longitudinal direction on the circumference of the axis of the broach tool body; An assembly-type inner surface broaching tool for finishing a high hardness material having a hardness of 45 to 65 HRC, comprising: a second blade group provided at a rear portion of the first blade group; and the second blade group includes at least one Because it is an assembly-type internal broach tool with more than one final finished size blade, even if the broach cutting edge size is out of the product tolerance range due to regrind of the cutting edge after broaching, it will be a new final A second blade group having a finish dimension blade can be processed into a predetermined dimension. In addition, since a second blade group having a length in the longitudinal direction shorter than that of the first blade group can be newly provided, the cost is lower and more advantageous than the new production of the first blade group.

  In addition, since the second blade group is an assembly-type inner surface broach tool having at least one adjustment blade in front of the final finish size blade, the final blade size of the first blade group varies due to regrinding. However, a stable workpiece machining dimension can be obtained by the adjusting blade of the second blade group and the final finished size blade.

  In addition, since the material of the first blade group and the second blade group is cemented carbide or CBN, the number of re-grinding of the expensive cemented carbide or CBN can be reduced even when finishing the hard material. The cost merit due to the increase is particularly large (claim 8).

  A first embodiment of the present invention will be described. FIG. 1A is a partial cross-sectional side view of a broach tool showing a first embodiment of the present invention, FIG. 1B is a cross-sectional view taken along line AA of FIG. 1A, and FIG. FIG. 2A is an enlarged side view of the first blade of FIG. 1, FIG. 2B is a sectional view taken along line BB of FIG. 1A, and FIG. 3A is FIG. A partial cross-sectional side view of a broaching tool in which a new second blade group is implanted, (b) is a cross-sectional view taken along the line DD of (a), and FIG. 9 is used in the description of the first embodiment of the present invention. It is a top view of the workpiece | work to do. In the first embodiment of the present invention, when the first blade group is new, the second blade group is not used. Instead, the spacer having the same longitudinal length as the second blade group is used as the first blade group. Broaching in a state of being provided behind the group. Then, after machining a certain amount, the wear part of the cutting edge of the first blade group is reground, and when the broach cutting edge dimension is outside the product tolerance range and the broach life is reached, the first blade group is Without being discarded, the spacer in the rear row of the first blade group is replaced with the second blade group and installed, and the number of regrinds can be increased to further perform broaching.

  The broach tool exemplified in the first embodiment of the present invention is a broach tool for finishing the three CVT ball grooves 44, 45, 46 of the workpiece 82 shown in FIG. The workpiece 82 to be machined has a hardness of 58 to 62 HRC by carburizing and quenching, and the CVT ball grooves 44, 45, 46 are pre-worked on the wall portion of the center hole 81 with a normal broach leaving a finishing allowance. The CVT ball grooves 44, 45, 46 are used for a movable sheave of a continuously variable transmission pulley apparatus having a movable sheave slidably supported on a shaft portion of a fixed sheave via a ball spline. As shown in FIGS. 1A, 1 </ b> B, and 1 </ b> C, the broach tool 51 has a plurality of grooves 2, 3, 4 extending in the longitudinal direction on the outer circumferential surface of the shaft 50 of the broach body 1. The first blade groups 5, 6, and 7 having the cutting edge 12 are implanted in the groove and fixed by fixing bolts 8, 9, and 10, respectively. A front guide 11 is provided in front of each of the first blade groups 5, 6, and 7 to determine and guide the phase of the pre-work groove of the workpiece and the broach cutting edge 12. Spacers 58, 59, 60 are respectively implanted in the grooves 2, 3, 4 behind the first blades 5, 6, 7 and fixed by fixing bolts 61, 62, 63. The broach tool 51 in this state is pulled out in the direction of the front guide 11, and the CVT ball grooves 44, 45, and 46 shown in FIG.

  After a certain amount of broaching with this broach tool 51, the worn cutting edges 12 of the first blade groups 5, 6 and 7 are reground. As shown in FIGS. 2A and 2B, the cutting edge 12 is raised from the first edge 14 to the final finishing edges 15 and 16 having the same shape. In addition, each cutting edge is assumed to have no straight land in order to ensure a sharpness in broaching of a hard material. When the first blade group 5, 6, 7 having the cutting edge 12 is subjected to a certain amount of finishing of the CVT ball grooves 44, 45, 46, the cutting edge of the cutting edge 12 is worn and the sharpness is deteriorated. Therefore, the rake face 42 is reground and reused. However, by cutting the rake face by w so that the wear part is eliminated, the cutting edge 12 is shaped as indicated by a dotted line. At this time, since the straight land is not provided, the dimensions of the final finished dimension blades 15 and 16 are reduced by b, and the groove dimension of the workpiece is also left uncut by b as compared to when the cutting edge 12 is new. When the re-grinding is repeated, the b dimension increases, and when the b dimension deviates from the product standard value of the workpiece, the life of the broach is reached. Normally, in this state, the first blade group 5, 6, 7 is discarded. However, in the first embodiment of the present invention, the spacers 58, 59, 60 provided behind the first blade groups 5, 6, 7 as shown in FIG. 1 are adjusted as shown in FIG. A broaching tool 55 is provided in place of the second blade group 52, 53, 54 made of cemented carbide having the blades 18, 19 and the final finished dimension blades 20, 21. As a result, the first blade groups 5, 6, and 7 are continuously used without being discarded. The second blade groups 52, 53, 54 are respectively implanted in the grooves 2, 3, 4 similarly to the spacers described above, and are fixed by fixing bolts 61, 62, 63. Even if the final finishing dimension blades 15 and 16 of the first blade group 5, 6 and 7 are dispersed by regrinding by the adjusting blades 18 and 19, stable workpiece machining dimensions can be obtained.

  Next, a second embodiment of the present invention will be described. 4A is a partial cross-sectional side view of a broach tool showing a second embodiment of the present invention, and FIG. 4B is a partial cross-sectional side view of the broach tool in which a new second blade group is implanted in FIG. FIG. Note that parts similar to those described above are denoted by the same reference numerals, and a part of the description is omitted. An example in which the workpiece shown in FIG. 9 is used will be described. In the second embodiment of the present invention, the first blade group described in the first embodiment is divided. In the second embodiment of the present invention, as shown in the broach tool 98 of FIG. 4A, the first blade groups 5, 6, and 7 are made of the first segment 90 and the second segment made of cemented carbide. The segment 91 is divided. Also in this case, as described above, after the broaching, the second segment having the new final finished size blades 20 and 21 behind the first segment 90 and the second segment 91 which have been reground and have a broach life. The workpiece is processed into a predetermined dimension by implanting the blade groups 52, 53, and 54. The first segment 90 and the second segment 91 are continuously used without being discarded.

  Next, a third embodiment of the present invention will be described. FIG. 5 (a) is a partial cross-sectional side view of a broach tool showing a third embodiment of the present invention, and FIG. 5 (b) is a partial cross-sectional side view of the broach tool in which a new second blade group is implanted in (a). FIG. Note that parts similar to those described above are denoted by the same reference numerals, and a part of the description is omitted. An example in which the workpiece shown in FIG. 9 is used will be described. In the third embodiment of the present invention, after a certain amount of broaching, the cutting edge of the first blade group is reground and cut into segments that have reached the cutting edge life and segments that can be reused. Dividing and discarding the front segment that has reached the cutting edge life, and then providing a second blade group with a new final finished size blade at the rear of the segment behind the remaining first blade group Broaching is performed. As shown in FIG. 5 (a), unlike the first and second embodiments of the present invention, the broach tool 65 of the third embodiment of the present invention is provided in front of the shaft 50 without providing a spacer. Only the guide 11 and the first blade group 23 made of cemented carbide are implanted. After a certain amount of broaching, the rake face of the worn part of the cutting edge 67 of the first blade group 23 is reground. At this time, if the cutting edge outer diameter of the cutting edge 67 deviates from the product tolerance, the first half portion 26 of the first blade group 23 is cut, and a new final finished dimension cutting edge 20 shown in FIG. , 21 to secure the space so that the second blade group 52, 53, 54 can be implanted. After that, the divided rear segment 24 is used as the first blade group 24 shown in FIG. 5B, and is planted on the shaft 50 so as to be in contact with the front guide 11. The blade groups 52, 53, and 54 are implanted on the shaft 50 to form a broach tool 66. Further, the segment 26 in front of the cut first blade group 23 is discarded.

  Next, a fourth embodiment of the present invention will be described. 6A is a partial cross-sectional side view of a broach tool showing a fourth embodiment of the present invention, and FIG. 6B is a partial cross-sectional side view of a broach tool in which a new second blade group is implanted in FIG. FIG. Note that parts similar to those described above are denoted by the same reference numerals, and a part of the description is omitted. An example in which the workpiece shown in FIG. 9 is used will be described. In the third embodiment of the present invention, the broach tool 65 shown in FIG. 5A uses only the first blade group 23 for the shaft 50, but in the fourth embodiment of the present invention, the broaching tool 65 shown in FIG. As shown in the broach tool 48 a), the first blade group is divided into a first segment 92 and a second segment 93 made of cemented carbide. In this case, the first half portion 94 of the first segment 92 that has reached the end of its life after broaching is cut and discarded, and the first blade group 92 is left as shown in the broach tool 49 of FIG. The rear half portion 95 is planted so as to contact the front guide 11. Next, the second segment 93 is implanted in the rear part of the rear half part 95, and the second blade groups 52, 53, 54 are implanted in the rear part of the second segment. Since the broach tool 49 has new final finish size blades 20 and 21 in the second blade groups 52, 53 and 54, the workpiece can be continuously processed to a predetermined size. Further, the cut first half portion 94 of the cut first segment 92 is discarded.

  Next, a fifth embodiment of the present invention will be described. 7A is a partial cross-sectional side view of a broach tool showing a fifth embodiment of the present invention, and FIG. 7B is a partial cross-sectional side view of the broach tool in which a new second blade group is implanted in FIG. FIG. Note that parts similar to those described above are denoted by the same reference numerals, and a part of the description is omitted. An example in which the workpiece shown in FIG. 9 is used will be described. In the fifth embodiment of the present invention, a group of blades having cutting edges is not divided after re-grinding, but is divided into two or more segments in advance. In the fifth embodiment of the present invention, when the broaching tool 70 shown in FIG. 7 is new, the first blade group 23 of the broaching tool 65 of FIG. It is characterized by being divided into two segments 78 and 79 made of hard alloy. The first segment 78 in FIG. 7A is implanted in series with the second segment 79. After a certain amount of broaching with this broaching tool 70, the wear portion of the cutting edge 80 is ground again, and then the outer diameter of the cutting edge 73 of the first segment 78 deviates from the product tolerance. Sometimes the first segment 78 is discarded. Next, the reusable second segment 79 is brought into contact with the front guide 11 to form a first blade group 75 (79) shown in FIG. A broaching tool 71 provided with a second blade group 52, 53, 54 having 21. With this broach tool 71, the workpiece can be continuously processed to a predetermined dimension.

  In the above-described embodiment of the present invention, the second blade groups 52, 53, and 54 to be newly implanted after re-grinding are composed of two final finish size blades 20, 21 and two adjustment blades 18, 19. Although it comprised, the number of final finishing dimension blades does not need to stick to two sheets, What is necessary is just one or more sheets. The adjusting blades 18 and 19 are not essential, but are preferably installed. In the above-described embodiment of the present invention, an example of a ball spline groove broach having three circumferences is shown. However, the number of grooves is not limited to three, and other shapes of groove broach such as an involute tooth profile. It goes without saying that the same applies to the above. In the above-described embodiment of the present invention, the material of the blade is a cemented carbide, but it may be CBN.

(A) is the partial cross section side view of the broach tool which shows 1st embodiment of this invention, (b) is the sectional view on the AA line of (a), (c) is the CC line of (a). It is sectional drawing. (A) is an enlarged side view of the 1st braid | blade of FIG. 1, (b) is the BB sectional drawing of (a). (A) is the fragmentary sectional side view which implanted the new 2nd blade group in the broach tool of FIG. 1, (b) is the DD sectional view taken on the line of (a). (A) is a partial cross-sectional side view of a broach tool showing a second embodiment of the present invention, (b) is a partial cross-sectional side view of a broach tool in which a new second blade group is implanted in (a). is there. (A) is a partial cross-sectional side view of a broach tool showing a third embodiment of the present invention, (b) is a partial cross-sectional side view of a broach tool in which a new second blade group is implanted in (a). is there. (A) is a partial cross-sectional side view of a broach tool showing a fourth embodiment of the present invention, (b) is a partial cross-sectional side view of a broach tool in which a new second blade group is implanted in (a). is there. (A) is a partial cross-sectional side view of a broach tool showing a fifth embodiment of the present invention, (b) is a partial cross-sectional side view of a broach tool in which a new second blade group is implanted in (a). is there. It is an enlarged side view of the cutting edge used for broaching of a high hardness material. It is a top view of the workpiece | work used by description of embodiment of this invention. It is sectional drawing of the broach tool by which the blade group was planted by the axis | shaft of the broach main body. It is an enlarged side view of the cutting edge which has a straight land.

Explanation of symbols

1 Body 2, 3, 4 Grooves 5, 6, 7 First blade group 11 Front guide 15, 16 Final finish dimension blade 17 of first blade group Cutting edge 18, 19 Adjusting blade 20, 21 Second blade group Final finishing dimensions of blade 50 Shaft 52, 53, 54 Second blade group 55 Assembly type inner surface broach tool 58, 59, 60 Spacer 61, 62, 63 Fixing bolt

Claims (8)

A processing method for finishing a high hardness material having a hardness of 45 to 65 HRC,
A first blade group having a cutting edge including a final finish dimension blade is implanted in a plurality of grooves formed so as to extend in the longitudinal direction on the circumference of the shaft of the rod-shaped broach tool body, and after the regrind, A broaching method comprising performing a broaching process by providing a second blade group having at least one or more final finished size blades at the rear part of the first blade group.   A spacer having a length in the longitudinal direction identical to that of the second blade group is provided at the rear part of the first blade group before re-grinding, and the spacer is moved to the second blade group after re-grinding the first blade group. The broaching method according to claim 1, wherein   After re-grinding the first blade group, discard the segment in front of the first blade group that has been or has been previously divided into at least two or more segments in the longitudinal direction; The broaching method according to claim 1, wherein the second blade group is provided at a rear portion of a rear segment.   The broaching method according to claim 3, wherein a longitudinal length of the front segment and a longitudinal length of the second blade group are the same. A rod-shaped broach tool body,
A first blade group having cutting edges implanted and reground in a plurality of grooves formed to extend in the longitudinal direction on the circumference of the axis of the broach tool body;
An assembly type internal broach tool for finishing a high hardness material having a hardness of 45 to 65 HRC, comprising a second blade group provided at the rear of the first blade group,
The assembly-type inner surface broach tool used for the broaching method as described in any one of Claims 1 thru | or 4. A rod-shaped broach tool body,
A first blade group having cutting edges implanted and reground in a plurality of grooves formed to extend in the longitudinal direction on the circumference of the axis of the broach tool body;
An assembly type internal broach tool for finishing a high hardness material having a hardness of 45 to 65 HRC, comprising a second blade group provided at the rear of the first blade group,
The assembly type inner surface broaching tool, wherein the second blade group has at least one or more final finished size blades.   7. The assembly type inner surface broaching tool according to claim 6, wherein the second blade group has at least one adjustment blade in front of the final finish size blade. The assembly type inner surface broaching tool according to claim 6 or 7, wherein a material of the first blade group and the second blade group is cemented carbide or CBN.

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