JP2019048352A - Method of manufacturing multi-thread female screw and tap tool - Google Patents

Abstract

To provide a method of manufacturing a multi-thread female screw and a tap tool that has excellent processing accuracy while reducing processing resistance during processing.SOLUTION: In formation of a multi-thread female screw M with a number of threads J, a tap tool T is inserted into a work W with a prepared hole M0 formed in advance, the tap tool T including Y threads of blades En for processing screw grooves Mn equivalent to a measure Y of the number of threads J which is a natural number larger than 1 and smaller than J, and being formed so that the Y threads of blades En are point symmetry relative to an axis X. Then, the tap tool T and the work W are relatively moved along the axis X while relatively being rotated around the axis X. Then, basic processing for forming a multi-thread female screw M of Y threads in the work W is executed (J/Y) times while positioning the blade En at a part where formation of the multi-thread female screw M has not finished in the prepared hole M0 by relatively rotating the tap tool T and the work W by an angle equivalent to a multiple of (360/J) degrees around the axis X.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for manufacturing a multi-threaded internal thread and a tap tool in which internal threads are formed by using a tap tool on a work in which a pilot hole is formed in advance, to form an internal thread having a plurality of threads.

  DESCRIPTION OF RELATED ART Conventionally, there exist some which were described in the following patent document 1, for example as what described the technique regarding the manufacturing method etc. of the multi-threaded internal thread which has several thread numbers.

  According to the technique described in Patent Document 1, a cylindrical tap tool having a helical thread on the outer peripheral surface is screwed into a pilot hole of a material to form a multi-threaded internal thread on the material. The tap tool used here has a smaller number of blades than the number of female threads formed in the material, and the distance along the circumferential direction of each blade is 360 ° divided by the number of female threads It is set to a multiple of.

  The tap tool is screwed into the lower hole formed in the material, and a thread groove smaller than the number of lines to be formed is formed in the material. Following this, the tap tool is rotated so that each blade of the tap tool is located at a portion of the inner circumferential surface of the hole where the internal thread is not formed. The rotation angle is a multiple of a value obtained by dividing 360 ° by the number of threads of the female screw to be formed. By screwing the tap tool into the lower hole in this state, an internal thread is formed in the remaining area.

  As described above, the technology of Patent Document 1 is to reduce the machining resistance of the tap tool by forming the multi-threaded internal thread while dividing the number of threads to be processed.

JP 2008-284571 A

  However, in the manufacturing method and the tap tool described in Patent Document 1, the number and arrangement of the blades to be functioned in one processing are not specified. For example, the number of blades of the blade is only smaller than the number of female threads. The arrangement interval along the circumferential direction between the blades is also a multiple of 360 degrees divided by the number of threads of the female screw. Therefore, for example, as shown in FIG. 2 of Patent Document 1, when the number of rows is 5, there may be a state where three blades are collected on one side of the circumference.

  When processing the material with such a tap tool, the processing load is concentrated on a partial region along the circumferential direction of the tap tool, so the tap tool is easily bent and deformed, and the processing accuracy of the female screw is deteriorated.

  In addition, when forming five internal threads, assuming that the number of blades of the tap tool is 3, in the second processing, one of the blades of the tap tool is one of the screw grooves formed in the first processing. Will be processed in layers. In this case, there is a possibility that the shape of the screw groove already processed once may be disturbed, and the shape of the screw groove of each strip may become uneven.

As described above, in the conventional method of manufacturing a multi-threaded internal thread, although the processing operation is improved by reducing the processing resistance, there is still room for improvement as to whether or not the multi-threaded internal thread with high accuracy is always formed. The
For these reasons, conventionally, there has been a demand for a method and tap tool for manufacturing multi-threaded internal threads with excellent machining accuracy while reducing machining resistance during machining.

(Feature configuration)
The characteristic configuration of the method for manufacturing multi-threaded internal thread according to the present invention is
When forming an internal thread with a thread number J,
For workpieces with pre-formed holes,
The Y-row blade is formed to process a thread groove of a submultiple Y which is a natural number greater than 1 and less than J of the number J, and the Y-row blade is formed to be point symmetrical with respect to the axis Insert the tap tool,
The tap tool and the work are fundamentally processed to relatively move the tap tool and the work along the axis while relatively rotating the tap tool and the work around the axis to form the female thread of the Y-strip on the work. Are relatively rotated by a multiple of (360 / J) degrees around the axis, and the blade is positioned at a portion of the pilot hole where the formation of the female screw is not completed (J / Y ) It is in the point to carry out.

(effect)
The tap tool used in the present manufacturing method is provided with a blade having a number Y of threads smaller than the number J of threads of the thread formed in the female screw, so that the machining resistance generated during one basic machining becomes small. Therefore, deformation such as twisting of the tap tool due to machining resistance is reduced, and the machining accuracy of the female screw is improved. Further, since the machining resistance is reduced, the required torque of the machining device can be reduced, and the multi-threaded internal thread can be machined efficiently.

  Furthermore, in the tap tool used in the present manufacturing method, the blades for Y strips are arranged so as to be point-symmetrical with respect to the axis. Therefore, since the machining resistance acting on the tap tool at the time of machining is distributed in a well-balanced manner around the axis, the tap tool is not bent and deformed at the time of machining, and an accurate thread groove can be formed.

  Moreover, since the number of blades of the blade formed on the tap tool is a divisor Y of the number J of female threads formed on the work, the shape of the already formed screw groove is disturbed when performing basic machining in multiple steps. You can proceed with processing so as not to Therefore, the precision of all the formed screw grooves is enhanced, and high quality multi-threaded internal thread can be obtained.

(Feature configuration)
In the manufacturing method of the multi-threaded internal thread according to the present invention, the tap tool is provided with a grip portion for gripping the tap tool and the blade of the Y strip as a second blade in a region adjacent to the grip portion. A second blade portion and an outer diameter dimension smaller than an outer diameter dimension of the second blade are provided in a region adjacent to the second blade portion on the opposite side to the grip portion, and the second blade portion A first blade having a number K of natural numbers equal to or less than the number J of the second blades and including one having continuous blade streaks, which is disposed point-symmetrically with respect to the axial center It is convenient to provide a first blade portion provided with

(effect)
When using the tap tool of the present method, when performing one basic processing, first, a screw groove is formed by the first blade formed at the tip of the tap tool. The outer diameter of the first blade is set smaller than that of the second blade, and it does not completely form the bottom of the female screw. The first blade is disposed point-symmetrically with respect to the axis, and the machining resistance acting on the tapping tool is disposed in a well-balanced manner around the axis. In addition, the number of first blades must be a natural number that is greater than the number of second blades and less than or equal to the number of female threads J. Therefore, the number and arrangement of the first blades are appropriately set according to the shape of the female screw, etc. can do.

  Following the processing of the first blade, the second blade performs processing. The second blade processes the Y groove thread groove which is a part of the J groove thread groove, and completely processes the tooth bottom to be formed.

  The first groove of the tap tool whose rotational phase has been changed in the second basic processing by processing the thread groove for K strips with the first blade with a small outer diameter is the screw groove formed in the first basic processing Guided by In the first basic processing, only the Y groove thread groove is completely processed by the second blade, but the other screw grooves are only shallowly processed by the first blade. Therefore, when performing the second basic processing, even if the first blade whose phase has been changed follows each screw groove, the first blade is a screw whose finish processing has been completed by the previous basic processing. It does not contact many areas of the groove.

  As described above, by using the tap tool of the present configuration, even when the thread grooves for Y strips are formed separately, the finishing process for each thread groove is performed once, and a multi-row internal thread with high accuracy is formed. be able to.

  Furthermore, by using the tap tool of this configuration, the phase of the tap tool is reliably set in the second and subsequent basic processings, and the degree of dependence on the phase setting of the tap tool on the processing machine is alleviated. Therefore, the cost of the processing facility can be reduced, and a highly accurate multi-threaded internal thread can be efficiently obtained.

(Feature configuration)
The characteristic configuration of the tapping tool for multi-row internal thread processing according to the present invention is
It has a blade and a grip to form a multi-row female screw with J number of threads,
The blade portion is
The second blade of Y strip for processing a thread groove of a submultiple Y which is a natural number greater than 1 and less than J of the number J is adjacent to the gripping portion in a state of point symmetry with respect to the axial center A second blade provided in the
The outer diameter dimension smaller than the outer diameter dimension of the second blade is provided in a region adjacent to the second blade portion on the opposite side to the grip portion, and has a blade streak continuous with the second blade. A first blade provided with a first blade which is a natural number more than the number of the second blades and not more than the number of the second blades and which is smaller than the number of the second blades and which is disposed point-symmetrically with respect to the axis It is in the point provided with

(effect)
The tap tool of this configuration is provided with only a Y-strip having a smaller number of thread grooves than the J-strip to be formed as the second blade, so that the machining resistance can be reduced. Moreover, since the second blades for Y strips are provided point-symmetrically with respect to the axial center, the occurrence of machining resistance is dispersed in a well-balanced manner around the axial center. For this reason, bending and twisting deformation do not occur in the tap tool during processing, and it is possible to form a multi-threaded internal thread with high accuracy.

  In addition, when using the tap tool of this configuration, a shallow thread groove is formed by the first blade having a number K of rows which is a natural number equal to or smaller than the number of second blades and is a natural number greater than the number of second blades in the first processing. Is formed, and the Y groove thread groove is completely finished to the bottom of the tooth to be formed by subsequent processing of the second blade.

  By processing the thread groove for K strips with the first blade having a small outer diameter, the first blade follows each thread groove at the time of the second processing. In this case, the first blade does not come in contact with the area of most of the screw grooves that has already been finished. That is, in the second and subsequent processes, the phase of the tap tool is reliably set, and the second and subsequent processes become accurate.

  By using the tap tool of this configuration as described above, even when multi-threaded female threads are divided and formed for each thread groove of Y threads, one finishing process for completing each thread groove is performed once, and the accuracy is high. An internal thread can be formed. Furthermore, since the dependency on the drive accuracy of the processing machine in setting the phase of the tap tool is alleviated, the cost of the processing facility can be reduced, and a highly accurate multi-row internal thread can be efficiently obtained.

An external view showing a tap tool according to a first embodiment Explanatory drawing which shows the manufacturing procedure of the multi-threaded internal thread which concerns on 1st Embodiment. An external view showing a tap tool according to a second embodiment Explanatory drawing which shows the manufacture procedure of the multi-threaded internal thread which concerns on 2nd Embodiment. Explanatory drawing which shows the structural example of the blade part in the tap tool of 2nd Embodiment

First Embodiment
A first embodiment of a method for manufacturing a tapping tool T for processing a multi-threaded internal thread M and a multi-threaded internal thread M according to the present invention will be described based on FIG. 1 and FIG. FIG. 1 is an external view showing the tap tool T, and FIG. 2 is an explanatory view showing a manufacturing procedure of the multi-threaded internal thread M. As shown in FIG.

(Appearance of tapping tool)
In the present embodiment, for example, an example in which a multi-strip internal thread M having four strips (M1 to M4) is cut and formed on the work W is shown. As shown in FIG. 1, the tap tool T used in the present embodiment is provided adjacent to the grip portion H formed on the base end side so as to be gripped by a machine tool or the like, and the workpiece W And a blade portion E for cutting and processing.

  The blade portion E is formed with, for example, two halves of blades E21 and E23 corresponding to four stripes which is the number of stripes J of the multi-strip female screw M to be formed. The two blades E21 and E23 are arranged symmetrically with respect to the axis X which is the rotation center. If symmetrical, the machining resistance at the time of machining acts in a well-balanced manner around the axis X in the circumferential direction. Therefore, the tap tool T is not bent or deformed during processing, or the rotational attitude is not disturbed, and the processing accuracy of the workpiece W is enhanced.

  As described above, in the tap tool T of the present embodiment, the blade E2n having a smaller number of rows Y than the number of rows J of the multi-row internal thread M to be manufactured is provided. However, when forming the multi-row internal thread M with the number of rows J, the number of rows Y of the blade E2n included in the tap tool T is a divisor of the number of rows J and is a natural number greater than 1 and smaller than J. As a result, the number of times of processing by the tap tool T becomes (J / Y) times, and the waste in which any of the screw grooves Mn is redundantly processed is eliminated. Incidentally, each processing is hereinafter referred to as basic processing.

(Manufacturing procedure of multi-row female screw)
FIGS. 2A to 2D show a manufacturing procedure of the multi-threaded internal thread M according to the first embodiment. Here, a case where a tap tool T provided with two blades E21 and E23 is used in order to form four multi-strip female threads M on a work W in which the lower hole M0 has been processed in advance. 2 (a) and 2 (b) are explanatory diagrams related to the first basic processing, and FIGS. 2 (c) and 2 (d) are explanatory diagrams related to the second basic processing. In an ordinary tap tool T, in order to facilitate cutting of the workpiece W, a tapered portion is provided near the tip so as to reduce the outer dimension so as to approach the tip.

  FIG. 2A shows a state immediately after the tapping tool T starts cutting the lower hole M0 of the workpiece W in the first basic processing. Thereafter, while the tap tool T is rotated around the axis X, the feeding operation is performed along the axis X. The relative rotational speed between the tap tool T and the work W at this time and the feed speed of the tap tool T along the axis X are preset according to the pitch of the multi-row internal thread M to be formed.

  FIG. 2B shows a state in which two thread grooves M1 and M2 are formed up to the end of the lower hole M0 of the workpiece W in the first processing. Since it is two screw grooves M1 and M3 to process and there are few numbers, the processing resistance which acts on the tap tool T is small. Therefore, the required rotational torque of the processing machine can be small, the holding power of the work W can be small, and a large-scale processing machine is not required. In addition, since the number of processed bars is small, the heat generation of the workpiece W is small at the time of processing, and the deformation of the workpiece W and the change in mechanical characteristics due to heat can be minimized.

  FIG. 2C shows a state in which the blades E21 and E23 are cut into the starting end of the lower hole M0 of the workpiece W in the second processing. After completion of the first basic machining, the tap tool T is rotated relative to the work W by a multiple of (360 / J) degrees, that is, 90 degrees, around the axis X, and the blades E21, E23. Is positioned in a portion of the lower hole M0 where the formation of the multi-threaded internal thread M is not completed. At this time, the processing machine (not shown) and the gripping device for the workpiece W grasp the posture of itself, and the relative angle between the tap tool T and the workpiece W is accurately set.

  FIG. 2D shows a state in which the second basic machining has been completed. As a result, four multi-strip female screws M are formed on the work W.

  By processing the number Y of threads smaller than the number J of threads of the thread groove Mn formed in the multi-threaded internal thread M in this way, the processing load at the time of one basic processing is reduced. Deformation and deterioration are prevented, and a multi-threaded internal thread M having an accurate shape is formed. The processing machine and the gripping device for the workpiece W are also simplified, and the processing of the multi-threaded internal thread M becomes efficient.

  Moreover, since the number of rows Y of the blade E2n formed on the tap tool T is a divisor of the number of rows J of the multi-thread female screw M formed on the work W, it has already been formed when dividing basic machining into multiple times. The shape of the thread groove Mn is not disturbed. Therefore, the precision of all the formed screw grooves Mn is enhanced, and a high quality multi-threaded internal thread M can be obtained.

Second Embodiment
A second embodiment of a method for manufacturing a tapping tool T for processing a multi-threaded internal thread M and a multi-threaded internal thread M according to the present invention will be described based on FIG. 3 and FIG. Also in this case, the number of threads J of the multi-threaded internal thread M is four.

(Appearance of tapping tool)
The external appearance of the tap tool T concerning 2nd Embodiment is shown in FIG. Of the blade portion E, at the tip end portion on the processing start side, four first blades E11 to E14 for processing are formed. This area is referred to as a first blade E1. A second blade portion E2 is formed on the side of the holding portion H continuously to the first blade portion E1. The second blade portion E2 here has two of the second blades E21 and E23. The second blades E21 and E23 are the same as the blades E21 and E23 in the first embodiment.
The two second blades E21 and E23 are formed continuously to the first blades E11 and E13. Note that all the first blades E11 to E14 are formed at point-symmetrical positions with respect to the axis X, and the two second blades E21 and E23 are also point-symmetrical with respect to the axis X.

  As shown in FIG. 3, the first blades E11 to E14 are formed in the tapered portion at the tip end, and the outer dimensions of the first blades E11 to E14 are smaller than the outer diameters of the second blades E21 and E23. Yes. Thus, for example, the depths of the screw grooves M1 to M4 processed by the first blades E11 to E14 are set to be a fraction of the depth of the completed screw grooves M1 to M4. By doing this, the machining resistance generated by the first blade E1 can be reduced, and the machining resistance in each basic machining can be suppressed low.

(Manufacturing procedure of multi-row female screw)
The manufacturing procedure of the multi-strip female screw M is shown in FIGS. 4 (a) to 4 (d). FIG. 4A shows a state in which the tap tool T bites into the lower hole M0 of the workpiece W. FIG. As shown in FIG. 4A, by forming all four first blades E11 to E14 in the first blade E1, four screw grooves to be formed at the start of the first basic processing All positions of M1 to M4 can be specified as the workpiece W.

  FIG.4 (b) has shown the state which is processing tap tool T by the 2nd blade part E2 for the lower hole M0 of the workpiece | work W. As shown in FIG. In the first basic processing, only the screw grooves M1 and M3 are finished.

  FIG. 4C shows a state in which the tap tool T bites into the workpiece W at the time of the second basic machining. At this time, the phase of the tap tool T is changed by 90 degrees. As a result, for example, the screw grooves M2 and M4 in the process of completion formed by the first blades E12 and E14 become guides when cutting the tap tool T in the second basic processing, and the screw grooves M2 and M4 have a phase again , And guides the first blades E11 and E13.

  FIG. 4D shows a state in which the tap tool T has been pulled out of the work W after the second basic machining is completed. As a result, the screw grooves M1 to M4 are finished on the work W.

  In the case of this embodiment, in the second basic processing, the screw grooves M2 and M4 formed in the first basic processing are not excessively processed. When the tap tool T is brought into contact with the workpiece W in the second basic processing, for example, the fixing of the rotational phase of the processing machine holding the tap tool T is loosened, whereby the positions of the first blades E11 and E13 are threaded M2, It is because it can align correctly to M4.

  Further, in the second basic processing, the first blades E11 and E13 follow the screw grooves M2 and M4 finished in the first basic processing, but in comparison with the depths of the screw grooves M2 and M4. Since the heights of the first blades E11 and E13 are low, the area of the surface of the screw grooves M2 and M4 that may be processed again by the first blades E11 and E13 is limited. Therefore, the thread groove Mn once finished and formed is not disturbed by the basic processing after the next time, and it is possible to obtain the multi-threaded internal thread M in a well-finished state. In addition, even when the multi-threaded internal thread M is divided into multiple processes, the relative position between the thread grooves Mn formed in each is accurately set, so it is possible to obtain the highly accurate multi-threaded internal thread M.

  Furthermore, when considering the machining resistance, in the second basic machining, the first blades E11 to E14 only follow the screw grooves M1 to M4 formed in the first basic machining, and only the second blades E21 and E23. Do new processing. Therefore, compared with the 1st basic processing accompanying processing with the 2nd blade E21 and E23, and processing with the 1st blade E11-E14, processing resistance which arises with the 2nd basic processing becomes smaller.

  That is, in the second basic processing, when processing with small processing resistance by the two second blades E21 and E23 is performed, a screw in which the four first blades E11 to E14 are formed in the first basic processing Since the grooves M1 to M4 are respectively copied, the processing position by the second blades E21 and E23 becomes extremely accurate. Therefore, by using the tap tool T of the present embodiment, machining of the multi-threaded internal thread M becomes efficient and highly accurate.

(Formation mode of the first blade and the second blade)
When constructing the tap tool T having the first blade E1 and the second blade E2, the following conditions are required for the configuration of each blade. For example, FIG. 5 shows a configuration example of the first blade E1 and the second blade E2 in the case where the number of threads J is eight.

  The number of threads Y of the second blade E2 is a natural number less than 2 and less than the number of threads J = 8 because the respective screw grooves Mn are not finished by being redundantly repeated by multiple basic machining by the second blade E2. And become a divisor of J. Therefore, in this case, the number of threads Y of the second blade E2 is two or four. The respective second blades E2n forming the second blade portion E2 are arranged point-symmetrically with respect to the axis X.

  On the other hand, the conditions for forming the first blade E1 are that all the second blades E2n are continuous and that they can be arranged point-symmetrically with respect to the axis X. Therefore, the number of stripes K of the first blade E1 is a natural number that is larger than the number of stripes Y of the second blade E2 and is the number of stripes J = 8 or less. In this case, the following variations can be obtained in the case of the number Y = 2 of the second blades E2 n and in the case of the number Y = 4.

  FIG. 5 schematically shows the positions of the first blade E1 n (black circle) and the second blade E2 n (white circle) formed on the outer peripheral surface of the tapping tool T. Among these, FIGS. 5 (a) to 5 (e) show the case where the number of threads Y of the second blade E2n is two. FIGS. 5 (a) and 5 (b) show the case where the number of rows K of the first blade E1n = 4, and FIGS. 5 (c) and 5 (d) indicate the number of rows K = 6, and FIG. It is a case of eight.

  On the other hand, in the case where the number of threads Y of the second blade E2n is four, as shown in FIG. 5 (f) and (g), the number K of threads for the first blade E1n is six and FIG. There are cases where the number of rows K = 8 as shown in FIG.

  With such a configuration, after the first basic machining is completed, the phase of the tap tool T is changed by an integral multiple of (360 / row number J) to obtain the first blade E1 n in the first basic machining. The second basic processing can be performed while using the thread groove Mn formed by the above as a guide. In that case, the thread groove Mn finished by the second blade E2n in the first basic processing is not redundantly processed in the second basic processing, and it is possible to obtain the multi-threaded internal thread M having a high finishing accuracy.

  In addition, the manufacturing method of the tap tool T and the multi-strip internal thread M according to the above embodiment is not limited to the one relating to the cutting tool T for cutting, and can be applied as the tapping tool T for roll forming.

  The present invention is widely applied to a method of manufacturing a multi-threaded internal thread forming a multi-threaded internal thread having a plurality of threads by using a tap tool to screw a workpiece having a pre-formed hole in advance and using the tap tool. Can.

E1 1st blade part E1n 1st blade E2 2nd blade part E2n 2nd blade En blade H grip part J number of threads K number of threads M multi-row internal thread M0 pilot hole Mn thread groove T tap tool W work X axis core Y number of threads

Claims (3)

When forming an internal thread with a thread number J,
For workpieces with pre-formed holes,
The Y-row blade is formed to process a thread groove of a submultiple Y which is a natural number greater than 1 and less than J of the number J, and the Y-row blade is formed to be point symmetrical with respect to the axis Insert the tap tool,
The tap tool and the work are fundamentally processed to relatively move the tap tool and the work along the axis while relatively rotating the tap tool and the work around the axis to form the female thread of the Y-strip on the work. Are relatively rotated by a multiple of (360 / J) degrees around the axis, and the blade is positioned at a portion of the pilot hole where the formation of the female screw is not completed (J / Y Method of multi-threaded internal thread). The tap tool is
A gripping portion for gripping the tap tool;
A second blade portion provided with the blade of the Y strip as a second blade in a region adjacent to the grip portion;
The outer diameter dimension smaller than the outer diameter dimension of the second blade is provided in a region adjacent to the second blade portion on the opposite side to the grip portion, and has a blade streak continuous with the second blade. A first blade provided with a first blade which is a natural number more than the number of the second blades and not more than the number of the second blades and which is smaller than the number of the second blades and which is disposed point-symmetrically with respect to the axis The method for manufacturing a multi-threaded internal thread according to claim 1, comprising: It has a blade and a grip to form a multi-row female screw with J number of threads,
The blade portion is
The second blade of Y strip for processing a thread groove of a submultiple Y which is a natural number greater than 1 and less than J of the number J is adjacent to the gripping portion in a state of point symmetry with respect to the axial center A second blade provided in the
The outer diameter dimension smaller than the outer diameter dimension of the second blade is provided in a region adjacent to the second blade portion on the opposite side to the grip portion, and has a blade streak continuous with the second blade. A first blade provided with a first blade which is a natural number more than the number of the second blades and not more than the number of the second blades and which is smaller than the number of the second blades and which is disposed point-symmetrically with respect to the axis A tap tool equipped with a part.

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