JP3750909B2 - Tapping jig - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tapping jig for tapping by attaching to a lathe.
[0002]
[Prior art]
When tapping, as shown in FIG. 3, first, the tapered shank 6 of the dedicated drill holder 5 is attached to the spindle 4 on the core push stand 3 side with respect to the work 2 attached to the spindle chuck 1 of the lathe. Then, a pilot hole 9 is drilled in the workpiece 2 with a drill 8 attached to the drill chuck 7 on the tip side. Thereafter, the drill holder 5 is removed from the spindle 4 and replaced with a tap holder 10, the tapered shank 11 is reattached to the spindle 4, and then the tap 12 at the tip is bitten into the pilot hole 9 of the workpiece 2. Tapping.
[0003]
[Problems to be solved by the invention]
By the way, in the said conventional method, since the drill exclusive holder 5 and the tap exclusive holder 10 have the taper shanks 6 and 11, respectively, they must be attached to the spindle 4 of the core push stand 3, and the tap exclusive holder 10 is drilled. It cannot be attached to the drill chuck 7 of the dedicated holder 5. Therefore, it is necessary to reattach each of them to the spindle 4 of the tailstock 3 and use the drill dedicated holder 5 and the tap dedicated holder 10 with much trouble. Further, since the core presser 3 is manually reciprocated during tapping, there is also a problem that it is difficult to increase the accuracy of the thread groove formed in the workpiece 2. The present invention aims to solve such problems.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the tapping jig according to the invention of the present application is for a workpiece attached to a lathe spindle, after drilling a pilot hole with a drill attached to a core push pad via a dedicated drill holder, In the tapping jig used when tapping with a tap attached instead of a drill to the core press stand,
A chuck grip portion attached to the chuck of the drill dedicated holder;
A cylindrical fixed collet provided integrally with the chuck gripping part,
A movable collet that is coaxial with the fixed collet and is movable back and forth via a guide member and provided with a tap mounting portion at one end, and
The movable collet and the fixed collet are arranged in the axial direction, and when the movable collet is retracted, one end is in contact with one end of the fixed collet so as to form one substantially cylindrical shape, and each axial center portion of the movable collet and the fixed collet A shaft hole side that is open toward the other side is provided on each side, and the movable collet is pulled toward the fixed collet side by locking both ends of the spring between the spring locking members inserted into the respective shaft holes from the side. Spring-biased in the direction ,
One end side of the guide member is fixed to the outer peripheral portion of the fixed collet, and the other end side is fitted to the outer peripheral portion of the movable collet so as to guide the movable collet so that the movable collet can advance and retreat in parallel with the axial direction of the movable collet and the fixed collet. Provided,
Attach the chuck holding part of the fixed collet to the holder dedicated to the drill of the core push stand, push the tip of the tap attached to the movable collet into the pilot hole of the work, and rotate the spindle to screw down the tap. Encroach into the hole, move the movable collet forward from the fixed collet by the amount of threading while being guided by the guide member against the spring, and then move the movable collet back to the fixed collet by the restoring force of the spring while rotating the work in reverse It is characterized in that the tap is extracted from the work by making it.
[0005]
Furthermore, the scale which displays the progress of a tapping with respect to either the said movable collet in the said invention, or a fixed collet can also be provided .
[0006]
【The invention's effect】
The tapping jig according to the present invention is provided with a chuck gripping portion on a fixed collet, and this chuck gripping portion is attached to a dedicated drill holder that is mounted in advance on a lathe core support for mounting a pilot hole drill. It can be attached to the drill chuck of the dedicated holder. Therefore, the tapping jig can be attached to the drill chuck as it is without exchanging the dedicated drill holder after drilling the pilot hole as in the prior art, so that it is not time-consuming to set up the tool.
In addition, a fixed collet and a movable collet that moves forward and backward are provided, and a spring that urges the movable collet in the pulling direction toward the fixed collet is provided, so the movable collet resists the tension of the spring during tapping. When the tapping is completed, the movable collet is quickly retracted by the restoring force of the spring and comes out of the work. Therefore, it is not necessary to manually reciprocate the core push table as in the prior art, and the accuracy of the thread groove can be easily increased. In addition, if the scale which displays the separation amount with the other side is provided in a movable collet or a fixed collet, the progress of tap processing can be easily confirmed by this scale.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment will be described below with reference to the drawings. FIG. 1 is an external view of a tapping jig according to the present embodiment, FIG. 2 is a cross-sectional view corresponding to line 2-2, and FIG. 3 is a diagram for explaining a lathe machining method. The same parts as those in the conventional example are denoted by the same reference numerals and the description thereof is omitted.
[0008]
As shown in FIGS. 1 and 2, this tapping jig 13 has a chuck holding part 20 (which is shown as a part A in FIG. ), A cylindrical fixed collet 21 in which the chuck grip 20 is integrally formed at one end, a movable collet 22 having a substantially cylindrical shape which is movable forward and backward on the same axis with respect to the fixed collet 21, The movable collet 22 includes a joint portion 23 formed integrally and projecting toward one end side of the movable collet 22, and a tap attachment chuck portion 27 attached to the joint portion 23.
[0009]
The tap attaching chuck portion 27 fixes the tap 12 on one end side in the axial direction, and is integrally provided with a joint protrusion 25 protruding from the other end side, and the joint protrusion 25 is formed in the axial direction from the distal end side of the joint portion 23. The movable collet 22 is detachable by fitting into the formed hole 24 and fixing with a pin 26 from the side.
[0010]
As is apparent from FIG. 2, the movable collet 22 has one end fixed to the fixed collet 21 side and a guide that slidably fits the other ends of a plurality of guides 28 provided parallel to the axial direction. It has a hole 29 and is movable forward and backward with respect to the fixed collet 21 while being guided by the guide 28.
[0011]
Further, shaft holes 30 and 31 are formed in the shaft center portions of the fixed collet 21 and the movable collet 22, and the coil spring 32 is inserted in a tensioned state therein, and both ends of the pins 33 and 34 are inserted from the side. The movable collet 22 is moved and urged to the fixed collet 21 side by being locked to.
[0012]
As is clear from FIG. 1, a scale 35 is provided on the side surface of the movable collet 22 so that the distance from the fixed collet 21 can be grasped by a pointer 36 extending from the fixed collet 21 side.
[0013]
Next, the operation of this embodiment will be described. In FIG. 3, when the drilling of the dedicated drill holder 5 by the drill 8 is completed, the drill chuck 7 of the dedicated drill holder 5 is loosened and the drill 8 is removed. Instead, the chuck gripping portion 20 of the tapping jig 13 is removed from the drill chuck. Attach to 7 and fix. Since the chuck holding portion 20 has a substantially triangular cross section and can be fixed by the drill chuck 7, the tapping jig 13 is attached to the drill chuck 7 of the dedicated drill holder 5.
[0014]
The tap 12 is attached to the tap attachment chuck portion 27 of the tap processing jig, and in this state, the tap 12 is moved toward the work 2 rotating integrally with the spindle chuck 1, and the tip of the tap 12 is moved to the pilot hole 9 of the work 2. When pushed in, tapping is started.
[0015]
As the threading progresses, the tap 12 bites into the pilot hole 9 of the workpiece 2, so that the movable collet 22 moves forward while being guided by the guide 28 against the elasticity of the coil spring 32 and gradually moves away from the fixed collet 21. .
[0016]
This separation amount is proportional to the threading depth and can be visually recognized from the scale 35 and the pointer 36, so that the progress of tapping can be easily recognized by the separation amount of the movable collet 22. Therefore, when it is confirmed from the display of the scale 35 and the pointer 36 that a predetermined threading amount has been reached, the tapping can be stopped accurately.
[0017]
Thereafter, when the workpiece 2 is reversed, the movable collet 22 is fed out of the workpiece 2 and pulled by the coil spring 32, so that the movable collet 22 quickly moves back to the fixed collet 21 side, and the tap 12 is moved from the workpiece 2. Get out.
[0018]
For this reason, it is not necessary to manually move the tap 12 as in the prior art, and the tap 12 is sent out in accordance with the reverse rotation of the work 2. Therefore, an excessive force is not applied to the tapped thread groove, and the thread groove is highly accurate. Can be formed.
[0019]
Thus, according to this tap processing jig 13, by providing the chuck gripping part 20, the drill holder 5 can be attached to the drill chuck 7 of the drill holder 5 without removing it from the core push stand 3. Therefore, it takes time to set up the tool conversion as in the prior art.
[0020]
The present invention is not limited to the above-described embodiments, and can be applied and modified in various ways. For example, an appropriate spring such as a leaf spring can be used instead of the coil spring 32. Also, the scale 35 provided on the fixed collet 21 side, may be provided guidance to the movable collet 22 side.
[Brief description of the drawings]
1 is an external view of a tapping jig according to an embodiment. FIG. 2 is a cross-sectional view corresponding to line 2-2. FIG. 3 is a diagram for explaining tapping.
1: spindle chuck, 2: workpiece, 3: core pusher, 5: drill holder, 7: drill chuck, 8: drill, 9: pilot hole, 10: tap holder, 12: tap, 13: tapping 20: chuck holding part, 21: fixed collet, 22: movable collet, 27: chuck part for tapping, 32: coil spring, 35: scale

Claims (2)

The workpiece mounted on the lathe spindle is drilled with a drill attached to the core press through a dedicated drill holder, and then tapped with a tap attached to the core press instead of the drill. In the tapping jig used at the time of
A chuck gripping portion mounted to the chuck before Symbol drill dedicated holder,
A cylindrical fixed collet provided integrally with the chuck gripping part,
A movable collet that is coaxial with the fixed collet and is movable back and forth via a guide member and provided with a tap mounting portion at one end, and
The movable collet and the fixed collet are arranged in the axial direction, and when the movable collet is retracted, one end is in contact with one end of the fixed collet so as to form one substantially cylindrical shape, and each axial center portion of the movable collet and the fixed collet A shaft hole side that is open toward the other side is provided on each side, and the movable collet is pulled toward the fixed collet side by locking both ends of the spring between the spring locking members inserted into the respective shaft holes from the side. Spring-biased in the direction ,
One end side of the guide member is fixed to the outer peripheral portion of the fixed collet, and the other end side is fitted to the outer peripheral portion of the movable collet so as to guide the movable collet so that the movable collet can advance and retreat in parallel with the axial direction of the movable collet and the fixed collet. Provided,
Attach the chuck holding part of the fixed collet to the holder dedicated to the drill of the core push stand, push the tip of the tap attached to the movable collet into the pilot hole of the work, and rotate the spindle to screw down the tap. Encroach into the hole, move the movable collet forward from the fixed collet by the amount of threading while being guided by the guide member against the spring, and then move the movable collet back to the fixed collet by the restoring force of the spring while rotating the work in reverse A tap processing jig characterized in that the tap is extracted from the work by causing the tap to be removed .   The tapping jig according to claim 1, wherein a scale for displaying a tapping progress is provided on either the movable collet or the fixed collet.

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