JP2004345027A - Assembly broaching tool, and broaching method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an assembly broaching tool, and a broaching method, in which axial machining vibration due to elongation by a tensile load is not generated even with a large machining load to prevent bad effects of cutting edge chipping due to vibration on tool life or product quality. <P>SOLUTION: A front grip part 1, a cylindrical part 3 continuous from the front grip part 1, a small diameter rod shaft part 6 protruded from the cylindrical part 3, and a hollow cylindrical assembly 4 provided with a number of cutting edges 16 of cemented carbide engaged in the small diameter rod shaft part 6 are integrally provided in a main body 5 of alloy steel. A preload P is applied in axial direction to the hollow cylindrical assembly 4 by double nuts 2(a) and 2(b) engaged with male threads 18 provided in the small diameter rod shaft part 6 close to a cylindrical or circular assembly rear end part to fix it. The preload P is set as P>W to a cutting load W in a broach advancing direction in broaching. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembling broach tool and a broaching method used for broaching spline holes, round holes, and the like.
[0002]
2. Description of the Related Art As a conventional assembly type inner surface broach, when it is desired to change the material of a cutting edge and a grip portion of a broaching tool, for example, an assembly broach as shown in FIG. was there. In such an assembly broach, broaching is usually performed by pulling a front grip portion.
[0003]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2002-137118
[0004]
However, in the assembling broach of Patent Document 1, as shown in FIG. 5, a hollow cylindrical member 32 having a cutting edge 31 is fixed to a set bolt 24 with a small diameter via a pressing member 33. The method of obliquely inserting and inserting and fixing the V-groove 26 provided in the rod-shaped shaft portion 25 in a diagonal direction has been employed, but there is a problem that the set bolt 24 is loosened. In addition, depending on the processing load, the small-diameter rod-shaped shaft portion 25 passing through the inside of the front grip portion 27 or the hollow cylindrical member 32 having the cutting edge 31 may be elongated due to a tensile load, thereby causing axial processing vibration. There is. In particular, when the machining load is large, a vibrant vibration occurs, which has an adverse effect on the tool life and the quality of the processed product. Particularly, in the case of a broach having a carbide cutting edge, there is a problem that the cutting edge is chipped by vibration.
[0005]
The object of the present invention is to solve the problems of the prior art, even when the processing load is large, the front grip portion, or the expansion due to the tensile load of the small-diameter rod-shaped shaft portion passing through the inside of the hollow cylindrical member having a cutting edge is caused. An object of the present invention is to provide an assembling broaching tool and a broaching method which do not generate machining vibrations in the axial direction, and do not adversely affect the tool life or the quality of a workpiece due to chipping due to the vibration.
[0006]
According to the first aspect of the present invention, an alloy steel body, a front grip portion, and a front grip portion provided integrally with the alloy steel body, respectively. A cylindrical portion provided with a plurality of guide portions on the outer periphery, a small-diameter rod-shaped shaft portion protruding from the cylindrical portion, and a hollow cylindrical shape provided with a number of carbide cutting edges fitted to the small-diameter rod-shaped shaft portion or The small-diameter rod-shaped shaft near the rear end of the hollow cylindrical or ring-shaped assembly, comprising at least one or more ring-shaped assemblies and a rear grip formed at the rear end of the small-diameter rod-shaped shaft. An assembly broach in which a preload is axially applied to the hollow cylindrical or ring-shaped assembly by a nut that is screwed into a male screw provided in the assembly broach. It is set so that P> W with respect to the cutting load W. It solved the problem of the present invention described above by assembling broaching tool and broaching method.
According to the second aspect of the present invention, an alloy steel main body, a front grip portion, a small-diameter rod-shaped shaft portion following the front grip portion, each of which is provided integrally with the alloy steel main body, A hollow cylindrical portion provided with a plurality of guide portions fitted on a rod-shaped shaft portion on the outer periphery thereof and at least one hollow cylindrical or ring-shaped assembly provided with a large number of cutting blades made of carbide; A rear cylinder portion having a vertical receiving surface that can be in close contact with the rear end surface of the assembly formed integrally with the rod-shaped shaft end portion, and a rear grip portion that follows the rear cylinder portion; An assembly broach in which a preload is applied in the axial direction to the hollow cylindrical or ring-shaped assembly by a nut that is screwed with a male screw provided on a small-diameter rod-shaped shaft in the vicinity, and the preload is applied to the broach. For cutting load W in the broaching direction by machining And to solve the problems of the present invention described above by the set assembled broaching tool and broaching method such as a P> W.
[0007]
According to the conventional products, one or more hollow cylindrical or ring-shaped assemblies having a front grip portion and a small-diameter rod-shaped shaft portion and provided with a large number of cutting edges are fitted to the small-diameter rod-shaped shaft portion. In the processing using an assembly broach fixed by applying a preload in the axial direction, when the front grip portion is pulled and processed, a tensile load is applied to the small-diameter rod-shaped shaft portion, and when the processing load is larger than the preload load, It is considered that an axial clearance is generated between the solid and the fixing member of the small-diameter rod-shaped shaft portion, the axial rigidity is extremely reduced, and processing vibration peculiar to broaching is increased.
On the other hand, according to the first and second aspects of the present invention, in the present invention, a nut which is screwed with a male screw provided on a small-diameter rod-shaped shaft part is axially attached to a hollow cylindrical or ring-shaped assembly. The preload is fixed by applying a preload P, and the preload P is set such that P> W with respect to the cutting load W in the broaching direction by broaching. Therefore, the preload does not completely disappear during the processing. If a small amount of preload remains, there is no axial clearance between the assembly and the nut that is the fixing member for the small-diameter rod-shaped shaft, and the rigidity in the axial direction is the rigidity of the small-diameter rod-shaped shaft alone. Rather, the assembly broach has a rigidity that is obtained by adding a small-diameter rod-shaped shaft portion and a hollow cylindrical or ring-shaped assembly, so that the amplitude of vibration can be reduced to a small level.
[0008]
Preferably, according to the first aspect of the present invention, by disposing a flat spring between the nut and the rear end of the hollow cylindrical or ring-shaped assembly, the load during machining is varied by applying a preload. Even if the pressure is stable, it can be maintained.
More preferably, in the second invention as set forth in claim 1, the preload P is set by a plurality of set bolts provided at right angles on the circumference of an annular nut end face screwed with a male screw provided on the small-diameter rod-shaped shaft portion. Each end is provided by pressing a collar disposed between the rear end of the hollow cylindrical or ring-shaped assembly and the annular nut, so that a relatively large preload can be applied. Can receive a large load due to broaching. While checking the runout accuracy of the broach with a large number of set bolts provided on the circumference of the end face of the annular nut, tightening in a well-balanced manner improves the assembling accuracy of the broach and allows the use of many set bolts. Loosening is less likely to occur.
More preferably, in the first invention according to claim 1, the collar and the rear end of the hollow cylindrical or ring-shaped assembly disposed between the rear end of the hollow cylindrical or ring-shaped assembly and the annular nut. By disposing the flat spring between the portion and the portion, a stable pressing force can be maintained even if the load during machining is changed by applying a preload.
[0009]
Preferably, according to the second aspect of the present invention, by disposing a flat spring between the nut and the front end of the hollow cylindrical portion, a stable pressing force can be obtained even when a load during machining is changed by applying a preload. Can be kept.
More preferably, in the second invention as set forth in claim 5, the preload P is a number of set bolts provided at right angles on a circumference of an end face of an annular nut screwed with a male screw provided on the small diameter rod-shaped shaft portion. Since each end is provided by pressing a collar disposed between the front end of the hollow cylindrical portion and the annular nut, a relatively large preload can be applied, and the broach applies a large load due to broaching. Can receive. While checking the runout accuracy of the broach with a large number of set bolts provided on the circumference of the end face of the annular nut, tightening in a well-balanced manner improves the assembling accuracy of the broach and allows the use of many set bolts. Loosening is less likely to occur.
More preferably, in the second aspect of the present invention, the spring is disposed between the collar disposed between the front end of the hollow cylindrical portion and the annular nut and the front end of the hollow cylindrical portion, whereby the preload is reduced. , A stable pressing force can be maintained even if the load during processing fluctuates.
Preferably, the nut is a double nut according to claim 1 or 5, so that the nut can be held even when a strong preload is applied.
[0010]
FIG. 1A is a schematic side view of an assembly broaching tool according to a first embodiment of the present invention. The left half shows a schematic front view, and the right half shows a schematic sectional view. . As shown in FIG. 1 (a), an assembled broach tool according to an embodiment of the first invention of the present invention comprises an alloy steel main body 5 and a front grip provided integrally with the alloy steel main body 5, respectively. Part 1, a cylindrical part 3 provided with a plurality of guide parts 15 on the outer periphery following the front grip part 1, a small-diameter rod-shaped shaft part 6 protruding from the cylindrical part 3, and a cemented carbide fitted to the small-diameter rod-shaped shaft part 6. A hollow cylindrical or ring-shaped assembly 4 (which may be composed of two or more) provided with a large number of cutting edges 16 made of stainless steel, and a rear grip 17 formed at the rear end of the small-diameter rod-shaped shaft. Have. The double cylindrical nuts 2 (a) and 2 (b) which are screwed with the male screw 18 provided on the small diameter rod-shaped shaft portion 6 near the rear end of the cylindrical or ring-shaped assembly form a shaft on the hollow cylindrical or ring-shaped assembly 4. It is an assembly broach fixed by applying a preload P in the direction. The preload P is set so that P> W with respect to the cutting load W in the broaching direction by broaching.
[0011]
That is, a compression load B is applied to the assembly 4 as a preload, and a tensile load A is applied to the shaft portion 6 as a preload, so that the assembly 4 and the broach main body 5 are integrated. At this time, the load A and the load B have the same magnitude and become forces in opposite directions, and are in balance with each other. In this embodiment, the magnitude of the load A or B, that is, the preload P is set to 5 tons.
Using such a broach, the work pre-processed with leaving a shaving margin on the involute spline tooth surface was heat-treated to a hardness of 60 HRC, and then the spline tooth surface was subjected to broach finishing. In order to control the processing load, the number of teeth of the involute spline to be processed was changed, and experiments were performed with the processing load of W = 3 tons, 4 tons, 5 tons, and 6 tons. FIG. 3 shows the results of measurement with the acceleration sensor. As a result, it was confirmed that, as predicted, when the setting of the preload P was set to P> W, especially at 5 tons or less, the machining vibration became extremely small.
[0012]
FIG. 1B is a schematic sectional view of an assembly broaching tool according to a second embodiment of the present invention. As shown in FIG. 1 (b), an assembled broaching tool according to a second embodiment of the present invention has an alloy steel main body 19 and a front grip provided integrally with the alloy steel main body 19, respectively. Portion 8, a small-diameter rod-shaped shaft portion 10 following the front grip portion 8, a hollow cylindrical portion 9 provided with a plurality of guide portions 20 fitted on the small-diameter rod-shaped shaft portion 10 on the outer periphery, and a number of cuts made of carbide. A hollow cylindrical or ring-shaped assembly 11 provided with a blade 21 (may be composed of two or more), and a rear portion of the assembly 11 integrally formed at an end of the rod-shaped shaft portion 10 of the alloy steel main body 19. Male screw provided on the small-diameter rod-shaped shaft portion 10 near the front end of the hollow cylindrical portion 9, having a rear cylindrical portion 13 having a vertical receiving surface 12 that can be in close contact with the end surface, and a rear grip portion 22 following the rear cylindrical portion 13. Hollow cylindrical shape by double nuts 14 (a) and 14 (b) screwed with Alternatively, it is an assembly broach in which the ring-shaped assembly 11 is fixed by applying a preload P in the axial direction, and the preload P is set so that P> W with respect to the cutting load W in the broaching direction by broaching. Have been. That is, a compressive load B is applied to the hollow cylindrical or ring-shaped assembly 11 and a tensile load A is applied to the rod-shaped shaft portion 10 as a preload, and the cylindrical portion formed integrally with the assembly 11 and the alloy steel main body 19 is formed. 13 are integrated. Even in the broach having such a configuration, as in the embodiment of FIG. 1A, when the setting of the preload P is set to P> W, the machining vibration is reduced.
[0013]
FIG. 1 (c) is a schematic sectional view of an assembly broaching tool according to another embodiment of the second invention of the present invention, and differs from the assembly broaching tool shown in FIG. 1 (b) by double nuts 14 (a) and 14 (a). By disposing the flat spring 40 between (b) and the front end of the hollow cylindrical portion 9, a stable pressing force can be maintained even if the load during machining is changed by applying a preload. The same construction is also applied to the assembling broach tool shown in FIG. 1 (a), between the rear end of the hollow cylindrical or ring-shaped assembly 4 and the double nuts 2 (a), 2 (b). Can be implemented.
[0014]
FIG. 2 is a side view of an assembly broaching tool according to still another embodiment of the second invention of the present invention. The left half shows a schematic side view, and the right half shows a schematic cross-sectional view. 1 (b), an annular nut 41 screwed with a male screw 23 provided on the small-diameter rod-shaped shaft portion 10 instead of the nut 14 (a) is screwed into the end face circle of the annular nut 41. Each end of a large number of set bolts 42 provided at right angles on the circumference presses a collar 43 disposed between the front end of the hollow cylindrical portion 9 and the annular nut 41, so that a preload P is applied. A large preload can be applied. Similar to the assembly broaching tool shown in FIG. 1C, a flat spring 44 is arranged between the collar 43 pressed by the annular nut 41 and the front end of the hollow cylindrical portion 9. While checking the run-out accuracy of the broach with a large number of set bolts 42 provided on the circumference of the end face of the annular nut 41 and tightening in a well-balanced manner, the assembling accuracy of the broach is improved and a large number of set bolts 42 can be used. The loosening of the set bolt 42 is less likely to occur. The preload P is set such that P> W with respect to the cutting load W in the broaching direction by broaching. That is, a compressive load B is applied to the hollow cylindrical or ring-shaped assembly 11 and a tensile load A is applied to the rod-shaped shaft portion 10 as a preload, and the cylindrical portion formed integrally with the assembly 11 and the alloy steel main body 19 is formed. 13 are integrated. Even in the broach having such a configuration, as in the embodiment of FIG. 1A, when the setting of the preload P is set to P> W, the machining vibration is reduced.
The same configuration is also applied to the assembling broach tool shown in FIG. 1A by using an annular nut (not shown) that is screwed with a male screw 18 provided on the small-diameter rod-shaped shaft portion 6 near the rear end of the cylindrical or ring-shaped assembly. The same can be achieved by disposing a collar and applying a preload P to the hollow cylindrical or ring-shaped assembly 4 in the axial direction.
[0015]
3 (a) is an enlarged bottom view of the annular nut 41 shown in FIG. 2, (b) is a schematic side view of the annular nut 41 shown in (a), and (c) is an enlarged schematic top view of the flat spring 44 shown in FIG. In the figure, the flat springs 44 are shown in an extended state, respectively. A set bolt 42 is provided on the annular nut 41. In the schematic side view shown in (b), a typical set bolt tap hole 46 is indicated by a one-dot chain line. In the embodiment shown in FIGS. 2 and 3, the annular nut 41 is provided with a screw hole 47 into which a screw (not shown) for preventing loosening is screwed so that the annular nut 41 is not loosened. . A screw (not shown) presses the male screw 18 provided on the small-diameter rod-shaped shaft portion 6 with a soft alloy (not shown) interposed at the tip of the screw hole 47 to prevent the annular nut 41 from loosening.
In FIGS. 1 (a) and 1 (b), the nuts 2 (a), 2 (b), 14 (a) and 14 (b) are double nuts, so that they can be held even when a strong preload is applied. it can.
[0016]
[Effects of Embodiments of First and Second Inventions] Since the configuration of the first and second embodiments of the present invention is adopted, in each of the assembly broaches, the preload P is set in the direction of movement of the broach by broaching. Since the cutting load W was set so as to satisfy P> W, it was possible to prevent a decrease in rigidity due to preload loss. As a result, the occurrence of machining vibration can be suppressed, and good machining quality can be obtained. In addition, chipping of the cutting edge due to vibration with the broach of the carbide cutting edge was reduced, and the life was improved.
[Brief description of the drawings]
1A is a schematic side view of an assembly broaching tool according to an embodiment of the first invention of the present invention, in which a left half is a schematic front view, a right half is a schematic sectional view, and FIG. A schematic sectional view of an assembly broaching tool according to a second embodiment of the present invention is shown, and (c) is a schematic sectional view of an assembly broaching tool according to another embodiment of the second invention of the present invention.
FIG. 2 is a schematic sectional view of an assembly broaching tool according to still another embodiment of the second invention of the present invention.
3A is an enlarged right side view of an annular nut 41 shown in FIG. 2, FIG. 3B is a schematic top view of FIG. 2A, and FIG. 3C is an enlarged schematic view of a flat spring 44 shown in FIG. In the top view, the flat spring 44 is shown in an extended state.
FIG. 4 shows an experiment in which the number of teeth of an involute spline to be machined is changed by using the assembly broaching tool of FIG. 7 is a graph showing a result of measuring a processing vibration on a table on which a workpiece is placed with an acceleration sensor.
FIG. 5 is a schematic side view of a conventional assembly broaching tool, in which an upper half shows a schematic front view and a lower half shows a schematic sectional view.
[Explanation of symbols]
1, 8 · · · front gripping part 2 (a), 2 (b), 14 (a), 14 (b) · · · nut 3 · · · cylindrical part 4, 11 · · · hollow cylindrical or ring provided with many cutting edges -Shaped assemblies 5, 19-alloy steel body 6, 10,-small-diameter rod-shaped shaft part 13,-rear cylindrical part 9,-hollow cylindrical part 15, 20,-guide part 16, 21,-cutting edge 17, 22 Rear grip part 18, 23 Male screw 40, 44 provided on small-diameter rod-shaped shaft part Flat spring 41 Ring nut 42 Set bolt 43 Collar P Preload W broach Cutting load in the broaching direction by machining

Claims (10)

An alloy steel body, a front grip portion provided integrally with the alloy steel body, a cylindrical portion provided with a plurality of guide portions following the front grip portion on an outer periphery, and a small-diameter rod projecting from the cylindrical portion. A shaft portion, at least one or more hollow cylindrical or ring-shaped assemblies provided with a number of carbide cutting edges fitted to the small-diameter rod-shaped shaft portion, and after being formed at the rear end of the small-diameter rod-shaped shaft portion; A grip portion; and a nut that is screwed into a male screw provided on the small-diameter rod-shaped shaft portion near the rear end of the hollow cylindrical or ring-shaped assembly. An assembly broach, wherein the preload is set to satisfy P> W with respect to a cutting load W in the broaching direction by broaching. The broaching tool according to claim 1, wherein a flat spring is disposed between the nut and the rear end of the hollow cylindrical or ring-shaped assembly. The preload load P is such that each end of a large number of set bolts provided at right angles on the circumference of an end face of an annular nut screwed with a male screw provided on the small-diameter rod-shaped shaft portion is formed after the hollow cylindrical or ring-shaped assembly. An assembly broach tool according to claim 1, wherein the tool is provided by pressing a collar disposed between an end and the annular nut. A flat spring is disposed between the collar disposed between the rear end of the hollow cylindrical or ring-shaped assembly and the annular nut and the rear end of the hollow cylindrical or ring-shaped assembly. An assembly broach tool according to claim 3, wherein The alloy steel main body, the front grip portion, which is provided integrally with the alloy steel main body, a small-diameter rod-shaped shaft portion following the front grip portion, and a plurality of guide portions respectively fitted to the small-diameter rod-shaped shaft portion. At least one or more hollow cylindrical or ring-shaped assemblies provided with a hollow cylindrical portion provided on the outer periphery and a plurality of cutting edges made of carbide, and the set integrally formed at the end of the rod-shaped shaft portion of the main body. It has a rear cylindrical portion having a vertical receiving surface that can be in close contact with the three-dimensional rear end surface, and a rear grip portion following the rear cylindrical portion, and is screwed with a male screw provided on a small diameter rod-shaped shaft portion near the front end of the hollow cylindrical portion. A preload applied axially to the hollow cylindrical or ring-shaped assembly by a nut to be fixed, wherein the preload P is P with respect to a cutting load W in the broaching direction by broaching. Assembly blow set to be> W Tool. The assembly broaching tool according to claim 1, wherein a flat spring is disposed between the nut and the front end of the hollow cylindrical portion. The preload load P is such that each end of a number of set bolts provided at right angles on the circumference of an end face of an annular nut screwed with a male screw provided on the small-diameter rod-shaped shaft portion has the front end of the hollow cylindrical portion and the annular nut. 2. The assembly broaching tool according to claim 1, wherein the tool is provided by pressing a collar disposed therebetween. The broaching tool according to claim 3, wherein a spring is disposed between the collar disposed between the front end of the hollow cylindrical portion and the annular nut and the front end of the hollow cylindrical portion. The assembly broach tool according to claim 1 or 5, wherein the nut is a double nut. A broaching method using the assembly broaching tool according to any one of claims 1 to 8.

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