JPS582010B2 - Thread groove processing device using tap - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thread groove machining device for facilitating the engagement of a tap in a tapping operation.

In conventional tapping work, the workpiece is drilled with a drill, and in order to make it easier for the tap to bite into the prepared hole, a tapping machine or screw pusher is used to make the feed pitch on the drive side and the thread pitch the same. However, this method can only be used for tapping a special panel or a comparatively small-diameter prepared hole, and is not used for tapping large-diameter screw holes such as cylinder covers of marine engines or flanges of tanks of nuclear power equipment. Since it cannot be used for this purpose, the tap may not engage properly, resulting in idling or thinning of the thread, resulting in a lower thread, which reduces engagement with the male thread, resulting in weaker threads and poor accuracy. However, there were drawbacks such as poor accuracy because the guide screw errors and tap errors found in conventional tapping attachments were not absorbed.

The present invention aims to eliminate these drawbacks and provides a thread groove machining device using a tap that can improve workability and thread accuracy in tapping work of large diameter holes.

An embodiment of the present invention will be described below based on the drawings.

In the drawing, 1 is a tap biting processing device, 2 is a drive shaft, and 3 is a driven shaft. The drive shaft 2 and the driven shaft 3 are connected by a clutch 4, and a guide nut 7 is attached to the tap 6 on the driven shaft 3 side. Further, a drum 8 is rotatably fitted on the outer periphery of the guide nut 7 and the drive shaft 2, and a brake ring 9 with a protrusion 10 inserted into a fixed rod 11 is mounted on the outer periphery of the drum 8. It is fitted.

1A is the axis of the tap biting processing device 1.

The drive shaft 2 forms a tapered part that connects to the main shaft of a drilling machine, etc., and has a hole 2A in which the main shaft is fixed with a screwdriver approximately in the center, and a screw 2B for a ring that sets a torque limiter. A recess 2E is bored into which the spline shaft fits.

Note that the above spindle moves a certain distance in the direction of its axis (slopping).
is made possible.

2c is a cap-shaped cylindrical portion provided at the tip of the drive shaft 2, and the shaft center 1
A through hole 2 is provided in the flange of the cylindrical portion 2c.
A plurality of D are provided.

Reference numeral 12 denotes a spline shaft, which is fitted and implanted into the recess 2E, and whose other end is slidably fitted into the torque limiter ring 13.

The tip 13B of the torque limiter ring 13 is connected to the clutch 4.
The other end 13C is provided with a plurality of compression springs 14 set in the through hole 2D of the cylindrical portion 2C, each having a torque corresponding to the cutting resistance generated during tapping.

Note that the compression spring 14 is compressed by the spring housing 15 and the screw 2
The pressing force is adjusted by a torque setting ring 16 screwed onto B.

The driven shaft 3 is connected to the drive shaft 2 via a torque limiter ring 13.
The other end is connected to the tap socket 17 through the socket holder 20, and the tap 6 is disposed at the tip.The tap socket 17 is fitted into the tongue portion 6A of the tap 6, and the set screw 18 It is stuck in place.

The tap socket 17 is integrally provided with a spline shaft 17A, which is fitted into the socket holder 20.

Further, a tapered portion 19 is provided on the outer periphery of the socket holder 20, and comes into contact with a tapered portion 22 formed inside the driven holder 21, thereby making it possible to center the socket holder 20 and the driven holder 21.

Then, by screwing the socket holder presser 23 to the driven holder 21, the socket holder 20 and the driven holder 21 are
Further, the socket holder 20 and the driven holder 21 are firmly fixed by a holder fixing bolt 24.

Further, the end surface 21A of the driven holder 21 fits into the uneven surface of the tip 13B of the torque limiter ring 13 and becomes integral.
It constitutes the clutch 4.

A bearing 25 is provided between the driven holder 21 and the cylindrical portion 2C to ensure smooth rotation.

A radial bearing 26 is fitted onto the outer peripheral surface of the cylindrical portion 2C, and allows the drum 8 to rotate freely via a bearing sleeve 27.

The thrust bearing intermediate ring 28 and the thrust receiver 29 are rotated with respect to each other via bearings 30, and the end faces of the thrust receivers 29 are prevented from moving by a C-shaped retaining ring 31.

The guide nut 7 is made removable by a guide presser 36.

Further, a flange portion 33 projects from the guide nut 7.

A sleeve 34 is provided to cover the outside of the driven shaft 3 and connects the guide nut 7 and the drum 8.

34A is an end of the sleeve 34 on the guide nut 7 side, into which a torque bin 35 is fitted, and the end 34A and the flange 33 are integrally connected by a guide nut holder 36.

34B is the end of the sleeve 34 on the drum 8 side;
It is connected to the lower surface of the driven shaft side by a key or pin 37, and is integrally held by a sleeve holder 38.

Further, the sleeve 34 is provided with a plurality of through holes 34C in the circumferential direction for adjusting the screw 18 of the tap socket 17.

The drum 8 is rotatable by a radial bearing 26 provided between the drum 8 and the cylindrical portion 2C, and is held by a brake ring 9 fitted externally.

The brake ring 9 has a C-shaped cylindrical shape with a part cut out, and a plurality of grooves 40 are cut in the vicinity of this notch 43, and a tightening screw 42 is attached to a protrusion 41 for tightening the brake ring 9. The other end has a protrusion 10 with a groove 10A formed thereon, and a fixing rod 11 is clamped thereto.

Note that one end of this fixed rod 11 is attached to the machine body (not shown).

Next, the working order of the present invention will be explained.

First, the tap biting processing device 1 is connected to the main shaft of the drilling machine (
(not shown) from below, and the tap 6 at the tip is brought into contact with a pilot hole drilled in a workpiece (not shown) with a drill or the like to align the tap axis 1A with the hole axis.

Then, rotate the brake ring 9 with it released,
After confirming the tapping position, tighten the tightening screw 42, the brake ring 9 tightens the drum 8, and the sleeve 2
1 to secure the nut 7.

Therefore, when the drive shaft 2 fitted to the main shaft of a drilling machine etc. rotates, the rotation is transmitted to the driven holder 21 by the clutch mechanism of the torque limiter ring 13 fitted to the spline shaft 12 embedded in the drive shaft 2. The tap 6 fitted in the tap socket 17 is rotated while being guided by the guide nut 7 via the spline shaft 17 fitted in the socket holder 20 integrated by the tapered part 19 of the driven holder 21. It can bite smoothly into the prepared hole of the workpiece.

Therefore, after cutting 3 to 4 threads of the screw and creating a path for the screw to bite, loosen the screw 42 and attach the brake ring 9 to the drum 8.
When released from the guide nut 7, the guide nut 7 rotates together with the tap 6, and a tapping operation similar to the conventional manual tapping operation can be performed, so that the tapping operation of the first tap can be performed subsequently.

At this time, the guide nut 7, sleeve 34, and drum 8 rotate together and move forward in the screw tightening direction, and the drive shaft 2, which holds the drum 8 in the axial direction, also moves in the axial direction. Since it is fixed to the main shaft of the drill press, the entire processing device 1 moves forward in the direction of driving the screw.

Also, if an abnormal torque exceeding the set torque is applied to the tap 6 during tapping work, the compression spring 14 acts on the clutch 4 and only the drive shaft 2 idles, so the tap 6 and the processing device stop, and the tap 6 Damage can be prevented.

In the above configuration, the tap 6 attached to the tap biting processing device 1 has been described as an ordinary tap, but it is also possible to use a tap 44 with a guide screw.

As described above, according to the thread groove machining device using a tap of the present invention, when the tap is inserted into the prepared hole, the brake band is tightened to fix the guide nut, and the tap is guided by the guide nut and inserted into the prepared hole. Definitely bites in.

In addition, when performing the original tapping operation, if the brake band is released to free the guide nut, the tap will be guided along the guide thread groove formed when it bites, which will affect the thread error of the guide nut. Highly accurate thread grooves can be obtained.

Furthermore, remarkable practical effects can be expected, such as easy cutting of threads by simply replacing the tap and guide nut according to the thread diameter.

[Brief explanation of drawings]

FIG. 1 is a cutaway longitudinal sectional front view showing the structure of the present invention, FIG. 2 is a perspective view of the main part, and FIG. 3 is a drawing showing the structure of another tap. 1...Tap biting processing device, 1A...Axis center,
2... Drive shaft, 2C... Cylinder part, 2E... Recessed part, 3
... Driven shaft, 4 ... Clutch, 6 ... Tap, 7
...Guide nut, 8.Drum, 9.Brake ring, 10.Protrusion, 11.Fixing rod,
12...Spline shaft, 13...Torque limiter ring, 13B...Tip part, 14...Compression spring, 15
...Spring housing, 16...Torque setting ring, 17...
- Tap socket, 19... Tapered part, 20... Socket holder, 21... Follower holder, 21A... End face, 22... Taper part, 23... Socket holder holder, 24... Holder fixing bolt, 32... Guide screw portion, 34... Sleeve.

Claims (1)

[Claims] 1 A cylindrical portion is formed at the tip of the drive shaft, the rear end of the driven holder is rotatably held on the inner periphery of the tip of the cylindrical portion, and a torque limiter is provided in the cylindrical portion to connect the drive shaft and the driven holder. A socket holder having a tapered part for axial alignment is attached to the tip of the driven holder, a tap socket for holding a tap is held in the socket holder so as to be slidable in the axial direction, and the tip is The rear end of the sleeve located near the outer circumferential thread of the tap is rotatably supported on the outer periphery of the drive shaft tip cylinder part, and a guide nut that is screwed into the thread of the tap is attached to the tip of the sleeve. A brake ring is arranged around the outer periphery of the sleeve to prevent the tap and the guide nut from rotating together when the sleeve is tightened by the brake ring, and to prevent the tap and the guide nut from rotating together when the sleeve is released by the brake ring. A thread groove machining device using a tap, characterized in that it allows co-rotation with the tap.