JP4609789B2 - Internal broaching method - Google Patents

Description

The present invention relates to an inner surface broaching method for performing broaching by gripping a front grip part and a rear grip part of an inner surface broach tool.

  Conventionally, when inner surface broaching is performed using an inner surface broach tool, a front gripping portion gripping device 52 as shown in FIG. 11 has been used as described in the prior art of Patent Document 1. The front gripping part gripping device 52 has a structure in which a shank insertion hole 54 is provided in a main body 53, and four claws 55 can project into the shank insertion hole 54 radially on the axis of the main body 53. Yes. The front grip portion 56 to be clamped has a constricted portion 57 at one end in the longitudinal direction. The front grip 56 is inserted into the insertion hole 54, and the sleeve 58 is slid to the distal end side (upward in the figure) of the main body 53, whereby the claw 55 pushes the constricted portion 57 from four directions. As a result, the front grip 56 is clamped to the main body 53 via the claw 55 in the insertion hole 54. A spring 59 returns the sleeve 58 to the rear end side (downward in the figure) of the main body 53. Further, as a method for restricting the front gripping portion 56 in the broach rotation direction, as shown in FIG. 12, a single flat 40 is provided in the front gripping portion 56, and after inserting the front gripping portion 56 into the main body 53, the pin 67 is inserted into the main body 53. The thing inserted in the pin hole 68 of 53 is disclosed.

  Further, in Patent Document 2, as a gripping device for a front grip portion, a first constriction portion and a second constriction portion provided in a front grip portion are provided as a lower nail provided in a main body of the front grip portion gripping device, and A front gripping portion gripping device is disclosed in which each is clamped on an upper claw and the broach axis direction and broach rotation direction of the broach tool are regulated.

Further, in Japanese Patent Application No. 2003-49583 filed earlier by the applicant, tapered portions are provided at the front grip portion and the rear grip portion of the broach tool, and a pull head having a tapered surface that complements the tapered portion is pressed against the front grip portion. There is a broach tool gripping device that regulates the broach axis direction and the broach axis perpendicular direction of the broach tool by clamping.
JP-A-6-126526 JP 2003-165018 A

  However, when the front gripping part gripping device 52 as in Patent Document 1 is used, even if the claw 55 comes into contact with the constricted part 57 of the front gripping part 56 as shown in FIG. There is a gap in the broach axis direction between them, and the front gripping part 56 moves and vibrates in the broach axis direction with the main body 53 during broaching, which adversely affects the workpiece machining accuracy and the life of the broach tool. Was given. Further, regarding the regulation of the broach rotation direction, as shown in FIG. 12, a gap 69 for inserting the pin 67 is required, and this broach between the front grip 56 and the main body 53 during the broaching process. It moved or vibrated in the direction of rotation, which had a bad influence on the workpiece machining accuracy and broach tool life.

  Further, the front gripping part gripping device described in Patent Document 2 is focused on suppressing vibrations in the broaching axial direction and the rotation direction of the broaching tool, and is clamped only on the front gripping part side of the broaching tool. ing. For this reason, especially in the case of broaching high hardness materials where the hardness of the workpiece exceeds 45 HRC (Rockwell hardness C scale: the same applies hereinafter), the radial load applied to the broaching tool also increases. Even so, a front gripping device that can be fixed and clamped is expected.

  Further, the broaching tool gripping device of Japanese Patent Application No. 2003-49583 is configured to clamp both the front gripping part and the rear gripping part of the broaching tool. It is necessary to make the clamping force larger than the cutting load so that a gap is not generated in the tapered portion even if the broach tool extends in the axial direction during processing. For this reason, when the cutting force is large, a high-power clamping device using a hydraulic cylinder or the like is required, and the pull head may be enlarged. For this reason, the broach tool holding device which is not influenced by the cutting force at the time of broaching is expected.

The present invention has been made in order to solve the problems of the prior art, and can fix and clamp the broach axis direction and the axis perpendicular direction of the broach tool to suppress vibrations in the broach axis direction, the axis orthogonal direction and the rotational direction. Another object of the present invention is to provide a broaching method in which the gripping device does not increase in size even in broaching with a large cutting force.

For this reason, in the present invention, a rear grip having a front grip portion, a tapered portion that is adjacent to the constricted portion and expands in a direction opposite to the front grip portion, and a shoulder portion that is located on the front grip side of the constricted portion. An inner surface broach tool provided with a gripping part, and two or more claws capable of coming into contact with the front gripping part, and the front gripping part is pressed against the claws of the lower gripping device during clamping. A lower gripping device that fixes and clamps the direction perpendicular to the broach axis of the front gripping portion, two or more upper gripping device claws that can come into contact with the tapered portion of the rear gripping portion, and a lower portion of the upper gripping device main body The shoulder surface of the broach tool has a load receiving surface that can be pressed, and at the time of clamping, the tapered portion of the broach tool is pressed against the claw of the upper gripping device, and the load receiving surface is pressed against the shoulder surface. An upper gripping device that fixes and clamps the broaching axis direction and the broaching axis perpendicular direction of the rear gripping portion, and clamps the rear guiding portion of the broaching tool with the upper gripping device and unloads the lower gripping device. Clamp, after attaching the non-machined workpiece made of a high hardness material having a hardness of 45 to 65 HRC (Rockwell hardness C scale) and having a hollow cylindrical shape, raise the non-machined workpiece, insert the front gripping part, The lower gripping device is lifted, the front gripping portion is clamped by the lower gripping device, the broaching axis direction and the broaching axis perpendicular direction of the rear gripping portion are fixed by the upper gripping device, and at the same time the front gripping portion is fixed by the lower gripping device. Only the direction perpendicular to the broach axis of the gripping part is fixed, and a compression load is applied to the inner surface broaching tool while the rear gripping part and the front gripping part are fixed simultaneously. Thus, the raw workpiece is broached, and after the broaching, the upper gripping device is unclamped, and the lower gripping device is moved downward to take out the processed workpiece. The inner surface broaching method was used. That is, when clamping an internal broach tool having a front grip portion and a rear grip portion, only the direction perpendicular to the broach axis of the front grip portion of the internal broach tool is gripped and fixed by the lower gripping device provided on the broaching machine, and at the same time the upper grip The device grips and fixes the broach axis direction and the axis perpendicular direction of the rear grip portion of the broach tool. The clamp in the broach axial direction of the upper gripping device is regulated by pressing the shoulder surface provided at the rear grip portion against the load receiving surface of the upper gripping device. Thereby, even during broaching, the broach axis direction and the axis perpendicular direction of the inner surface broach tool are fixed, so that they do not vibrate or move. Also, the friction force that clamps the inner gripper tool of the lower gripping device and upper gripping device suppresses vibration in the broach rotation direction of the broach tool, so that the inner surface broach tool moves or vibrates in the broach rotation direction during broaching. Absent.

Further, by pressing the pawl provided on the front one hair-portion lower gripping device, with respect to vibrations that occur during broaching, broach axis perpendicular direction before gripping portion of the inner surface broaching tool is regulated so as not to move or vibrate .

Further, by pressing the claw provided on the upper gripping device against the tapered portion of the rear grip portion of the inner surface broach tool, the rear grip portion of the inner surface broach tool acts to be pulled toward the upper grip device side of the broaching machine. Furthermore, by pressing the shoulder surface of the rear gripping part against the load receiving surface of the upper gripping device, the inner broaching tool is moved in the direction of the broaching axis and the axis perpendicular to the rear gripping part of the broaching tool against vibrations that occur during broaching. Regulate not to vibrate or move.

Furthermore, since the inner surface broaching tool is subjected to a compressive load, and the inner surface broaching method is used to process a high-hardness material having a hardness of 45 to 65 HRC, the work described above can be solved. It was.

As described above, according to the present invention, the front gripping portion, the tapered portion that is adjacent to the constricted portion and expands in the opposite direction to the front gripping portion, and the shoulder portion that is located on the front gripping side of the constricted portion, An inner surface broaching tool having a rear grip portion, and two or more claws capable of coming into contact with the front grip portion, and the front grip portion is pressed against the claws of the lower gripping device at the time of clamping. Accordingly, the lower gripping device that fixes and clamps the direction perpendicular to the broach axis of the front gripping portion, the claws of two or more upper gripping devices that can be brought into contact with the tapered portion of the rear gripping portion, and the upper gripping device The lower part of the body has a load receiving surface to which the shoulder surface of the broach tool can be pressed, and at the time of clamping, the tapered portion of the broach tool is pressed against the claw of the upper gripping device and the load receiving surface is pressed against the shoulder surface. An upper gripping device that fixes and clamps the broaching axis direction and the broaching axis perpendicular direction of the rear gripping portion, and clamps the rear guide portion of the broaching tool with the upper gripping device, After unclamping and attaching a non-machined workpiece made of a high hardness material having a hardness of 45 to 65 HRC (Rockwell hardness C scale) into a hollow cylindrical shape, the unprocessed workpiece is raised, and the front gripping part is inserted, The lower gripping device is lifted, the front gripping portion is clamped by the lower gripping device, the broaching axis direction and the broaching axis perpendicular direction of the rear gripping portion are fixed by the upper gripping device, and at the same time, the lower gripping device Only the direction perpendicular to the broach axis of the front gripping part is fixed, and a compression load is applied to the inner surface broaching tool while the rear gripping part and the front gripping part are fixed simultaneously. The raw workpiece is broached, and after the broaching, the upper gripping device is unclamped, and the lower gripping device is moved downward to take out the processed workpiece. Since the broaching tool does not vibrate or move in the broach axis direction, the axis perpendicular direction and the rotation direction during broaching, the workpiece can be machined with high accuracy and the inner broaching tool used is also long. It was possible to have a lifetime. Furthermore, it was possible to provide a broaching machine in which the gripping device does not increase in size even in the case of broaching with a large cutting force.

The hardness of the workpiece is a hollow cylindrical shape is a inner surface broaching method of the high-hardness material 45～65HRC, since the inner surface broaching method of machining a workpiece as take compressive load to the blanking Roach tool Even when broaching high-hardness materials with a hardness of 45 to 65 HRC, the broach tool does not vibrate or move in the direction of the broach axis, the direction perpendicular to the axis and the direction of rotation, and the workpiece can be machined with high accuracy. Broach tools could also have a long life.

  Embodiments of the present invention will be described below with reference to the drawings. 1 is an elevational half sectional view of an upper gripping device showing an embodiment of the present invention, FIG. 2 is an elevational half sectional view of a lower gripping device showing an embodiment of the present invention, and FIG. 4 is a sectional view taken along line BB in FIG. 1, FIG. 5 is a sectional view taken along line CC in FIG. 2, and FIG. 6 is DD in FIG. FIG. 7A is a front view of a broach tool used in the embodiment of the present invention, FIG. 7B is a left side view of FIG. 8A, and FIG. It is a fragmentary sectional view which shows the state which used the up-and-down holding apparatus of this invention for the broaching machine.

  A detailed configuration of the upper gripping device 64 will be described with reference to FIG. As shown in FIG. 1, the claw 25 of the upper gripping device 64 used in the present invention is shown in an open state (unclamped state) in the right half sectional view and in a closed state (clamped state) in the left half sectional view. Yes. The upper gripping device 64 includes a constricted portion 7 provided in the longitudinal direction of the rear gripping portion 6, a tapered portion 8 adjacent to the constricted portion 7, and a shoulder surface located on the front gripping portion side of the constricted portion 7 (not shown). The rear grip 6 having 9 is clamped. The upper gripping device 64 is movably fitted in the radial hole 4 of the upper gripping device main body 1, and a claw 25 whose inner end portion 5 can come into contact with the tapered portion 8 of the rear gripping portion 6, and the rear gripping. A load receiving surface 10 that is in contact with the shoulder surface 9 of the portion. An escape groove 11 having a tapered portion 12 is provided on the inner surface of the sleeve 2. Further, as shown in FIG. 4, the restriction of the rear gripping portion 6 in the broach rotation direction is restricted by a notch 35 provided in the broach and a pin 24 provided in the upper gripping device main body 1. Also, as shown in FIG. 3, the two claws 25 are arranged opposite to each other so as to balance the load, but the number of claws does not have to be particular to two, and depending on the cutting load, it is three or more. Also good.

  As shown in the left half of FIG. 1, the rear grip 6 is clamped by pushing down the sleeve 2 to the lower gripping device side (downward) by an air cylinder (not shown). As a result, the outer end 72 of the claw 25 is brought into contact with the taper portion 12 provided in the relief groove 11 of the sleeve 2, and the taper portion of the rear grip portion 6 is interposed via the taper portion 12 by the pressing force of the air cylinder. 8 is pushed up to the upper gripping device side (upward). Then, the shoulder surface 9 of the rear grip portion is pressed against the load receiving surface 10 of the upper gripping device, whereby the broach axial direction and the axis perpendicular direction of the rear grip portion 6 are fixed and clamped. At this time, even if the clamping force of the claw 25 is smaller than the cutting force at the time of broaching, the rear grip portion 6 is fixed and clamped by the upper gripping device 64, but the broach axial direction generated at the time of broaching In addition, a force that suppresses vibration in the direction perpendicular to the axis is at least necessary. In this embodiment, the clamping force in the direction perpendicular to the broach axis of the rear grip portion 6 of the claw 25 is set to about 1/10 of the cutting load during broaching. This clamping force may be stronger or weaker depending on the broaching object, but need not be larger than the cutting load. In the present embodiment, the clamping is performed by the force of the air cylinder, but it goes without saying that other means such as a spring may be used. Further, as shown in the right half of FIG. 1, the unclamp of the broach moves the sleeve 2 to the upper gripping device side (upward) by an air cylinder (not shown), and the claw 25 is fitted in the relief groove 11 of the sleeve 2. This is done by setting the

  Next, a detailed configuration of the lower gripping device 63 will be described with reference to FIG. As shown in FIG. 2, the claw 33 of the lower gripping device 63 used in the present invention shows an open state (unclamped state) in the right half sectional view and a closed state (clamped state) in the left half sectional view. Yes. The lower gripping device 63 clamps the front grip portion 19 provided with the cylindrical portion 20. The lower gripping device 63 includes a lower gripping device main body 16, a sleeve 17 that is fitted to the outer periphery 38 of the lower gripping device main body 16, and is installed so as to be vertically movable, and two claws 33. Is provided with a relief groove 22 having a tapered portion 23. The claw 33 is movably fitted in the radial hole 18 of the lower gripping device main body 16 so that the inner end portion 13 can come into contact with the cylindrical portion 20 of the front grip portion 19. At this time, the rotation direction of the front grip portion 19 is restricted by a notch 27 provided in the front grip portion and a pin 39 provided in the lower gripping device main body 16 as shown in FIG. Further, as shown in FIG. 6, when clamping the cylindrical portion 20 of the front grip portion 19, the two claws 33 are arranged to face each other so that a load balance can be obtained. Note that the number of claws need not be limited to two, and may be three or more depending on the cutting load.

Further, the clamping of the front gripping portion 19 is performed by pushing up the sleeve 17 to the upper gripping device side (upward) by the spring 32 as shown in the left half of FIG. 2 (clamped state). As a result, since the outer end 31 of the claw 33 is in contact with the tapered portion 23 provided in the relief groove 22 of the sleeve 17, the constricted portion 20 is moved through the tapered portion 23 by the push-up force of the spring 32. Pressurize inward and clamp the front grip 19. The clamping force at this time is strong enough to suppress the vibration of the front grip portion 19 only in the direction perpendicular to the broach axis. In this embodiment, the clamping force is about 1/10 of the cutting load. Sometimes it may be weak. Further, as shown in the right half of FIG. 2 (unclamped state), the lower gripping device is unclamped by moving the sleeve 17 toward the lower gripping device (downward) and fitting the claw 33 into the relief groove 23 of the sleeve 17. This is done by setting it in a clogged state. In this embodiment, the clamping is performed by the spring 32, but other means such as an air cylinder may be used. In this embodiment, the front grip portion 19 provided with the constricted portion 20 is used. However, the present invention only requires that the front grip portion is pressed inward by the claw 33 and clamped by fixing the direction perpendicular to the broach axis. The present invention is not limited to the provision of the constricted portion.

  Next, FIG. 8 shows an example in which the inner surface broaching of the high-hardness material is performed on the broaching machine using the above-described upper gripping device 64 and lower gripping device 63 of the present invention. The workpiece 82 to be machined is made of carburized steel that has been carburized and quenched to a surface hardness of 60 HRC after pre-broaching with the allowance remaining on the spline hole tooth surface. As shown in FIG. 7, the broach tool for machining this workpiece is a super-grid arranged on the bar-shaped main body 13, the front grip portion 19, the rear grip portion 6, the front guide 51, the rear guide 34, and the dimension order. The inner broach tool 60 is provided with a hard alloy cutting edge 50.

  As shown in FIG. 8, the front gripping portion 19 of the inner surface broach tool 60 is clamped by the claw 33 of the lower gripping device 63 while the cylindrical portion 20 is fixed by the spring 32 through the sleeve 17. Further, the rear gripping portion 6 is clamped by the air cylinder 71 by the claw 25 of the upper gripping device 64 through the tapered portion 12 of the sleeve 2. The upper gripping device main body 1 is fixed to a machine column (not shown) via a sufficiently rigid upper bracket 65. The lower gripping device 63 is guided by a rigid rail guide (not shown), and is fixed to a moving table 79 that is installed below the lower gripping device main body 16 so as to be movable up and down. In a state where the front gripping portion 19 and the rear gripping portion 6 of the inner surface broach tool 60 are fixed and clamped by the lower gripping device 63 and the upper gripping device 64, the broach axis direction, the broach axis right angle, and the broach rotation direction of the inner surface broach tool 60. The backlash will disappear, and it will be firmly fixed with proper grasping power. The workpiece 82 before broaching is placed on a workpiece placing table 81 fixed to the workpiece moving table 80, and the front guide 51 of the inner surface broach tool 60 is inserted into the workpiece machining groove 81. Broaching is performed by moving the workpiece 82 from this state to the position of the rear guide 34 by using a driving device (not shown). After the machining of the final cutting edge 62 of the broach, the workpiece is decelerated and indicated by a two-dot chain line 83. Stop at the specified position. During this time, since the inner surface broach tool 60 is firmly clamped by the upper gripping device 63 and the lower gripping device 64, the vibration of the inner surface broach tool 60 due to broaching is extremely small.

  The workpiece 82 after broaching is taken out by unclamping the upper gripping device 64 and moving the lower gripping device 63 clamping the inner surface broach tool 60 downward. Further, the next unprocessed workpiece is attached by raising the lower gripping device 63 and clamping the inner surface broach tool 60 with the upper gripping device 64 and unclamping the lower gripping device. The gripping device is replaced, and the lower gripping device 63 and the workpiece moving table 80 are moved downward. After attaching the unprocessed workpiece, the workpiece moving table 80 is moved upward, the workpiece is inserted into the inner surface broach tool, the lower gripping device is lifted, the workpiece is inserted into the front guide 51 of the inner surface broach tool 60, and the grip after the broach is held. The part is clamped by the upper gripping device 64 to be in the state of FIG. 8 again, and broaching can be repeated.

  In this embodiment, the upper gripping device 64 shown in FIG. 1 is used as the upper gripping device. However, any upper clamp device may be used as long as it can firmly clamp the broaching axis direction and the axis perpendicular direction of the rear gripping portion 6, and other clamping forms are also possible. Conceivable. Another example is shown below. FIG. 9 is a partial cross-sectional view showing another example of the upper gripping device of the present invention, and FIG. 10 is a cross-sectional view (clamped state) taken along line EE in FIG. As shown in the left half of FIG. 9, the upper gripping device 99 presses the claw 92 provided on the upper gripping device main body 90 against the tapered portion 8 of the constricted portion 7 of the rear gripping portion 6 with a spring 93, and The shoulder surface 9 is pressed against the load receiving surface 96 of the upper gripping device main body 90 to clamp the broach axis direction and the axis perpendicular direction. Further, as shown in FIG. 10, the sleeve 91 is provided with relief grooves 43 and 44 on the inner peripheral surface. By rotating the lever 45 by a cylinder (not shown) in the direction of the arrow 46, the relief groove is indicated by a dotted line. At the positions 47 and 48 shown, the claw 92 fits into the escape groove, and the rear grip 6 is unclamped.

  In this embodiment, an example of broaching using a workpiece moving broaching machine has been shown. However, the workpiece moving table is fixed, the broach is clamped by the upper gripping device and the lower gripping device, and the upper gripping device and It goes without saying that the same effect can be obtained even if the lower gripping device is processed by being moved synchronously to the lower gripping device side (downward) by the NC device.

  The workpiece was processed by the broaching machine shown in FIG. 8 described in the embodiment of the present invention. As a result, the vibration generated in the internal broach tool was extremely small, and the chip was not chipped and the life was long. In addition, since the inner broach tool is completely fixed and stationary and the machining is performed, the position of the broach is kept unchanged even during machining, and the workpiece machining accuracy is improved.

It is an elevational half sectional view of the upper gripping device showing an embodiment of the present invention. It is an elevational half sectional view of the lower gripping device showing an embodiment of the present invention. It is AA arrow sectional drawing (clamp state) of FIG. It is a BB arrow directional cross-sectional view of FIG. It is CC sectional view taken on the line of FIG. FIG. 3 is a sectional view taken along line D-D in FIG. 2 (clamped state). (A) is a front view of the broach tool used by embodiment of this invention, (b) is a left view of (a). It is a fragmentary sectional view which shows the state which used the up-and-down holding apparatus of this invention for the workpiece moving type broaching machine. It is a fragmentary sectional view of the upper gripping device which shows another example of an embodiment of the invention. FIG. 10 is a cross-sectional view taken along line EE in FIG. 9. It is a fragmentary sectional view which shows the front grip part holding | gripping apparatus of a prior art example. It is FF arrow directional cross-sectional view of FIG.

Explanation of symbols

1 Upper gripping device body 6 Rear grip
7 Constricted portion 8 Tapered portion 9 Shoulder surface 10 Load receiving surface 15 Broaching machine 19 Front grip portion 25, 33 Claw 60 Inner surface broaching tool 63 Lower gripping device 64 Upper gripping device 82 Workpiece

Claims (1)

A front grip portion, a tapered portion adjacent to the constricted portion and having a diameter expanding in a direction opposite to the front grip portion, and a rear grip portion having a shoulder portion located on the front grip side of the constricted portion. An internal broach tool,
It has two or more claws that can come into contact with the front gripping part, and the front gripping part is pressed against the claws of the lower gripping device at the time of clamping, so that the direction perpendicular to the broach axis of the front gripping part is fixed. A lower gripping device for clamping;
A clamp having two or more upper gripping device claws capable of coming into contact with the tapered portion of the rear gripping portion, and a load receiving surface to which the shoulder surface of the broach tool can be pressed against the lower portion of the upper gripping device main body; Sometimes the taper part of the broach tool is pressed against the claw of the upper gripping device and the load receiving surface is pressed against the shoulder surface, and the upper part that clamps the rear grip part in the direction of the broach axis and the direction perpendicular to the broach axis. A gripping device,
The back guide part of the broaching tool is clamped by the upper gripping device, the lower gripping device is unclamped, and is processed into a hollow cylinder with a high hardness material having a hardness of 45 to 65 HRC (Rockwell hardness C scale). After attaching the workpiece, the unprocessed workpiece is raised, the front gripping portion is inserted, the lower gripping device is lifted, and the front gripping portion is clamped by the lower gripping device,
The upper gripping device fixes the broach axis direction and the broach axis perpendicular direction of the rear grip portion, and at the same time, the lower grip device fixes only the direction of the front grip portion perpendicular to the broach axis, and the rear grip portion and the front grip portion. Broaching the raw workpiece so that a compressive load is applied to the inner surface broach tool while simultaneously fixing the parts,
An inner surface broaching method, wherein after the broaching, the upper gripping device is unclamped and the lower gripping device is moved downward to take out the processed workpiece.

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