JPH0318098Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical background of the invention] The present invention relates to a die head of a thread cutting device.
In particular, it relates to improvements in die heads used for cutting tapered threads.

[Technical background of the invention]

When cutting a tapered thread in a pipe, a die head is generally used. In this case, a chaser (cutting blade) attached to the die head body is gradually moved in the radial direction according to the relative movement of the pipe and the die head in the axial direction. , it becomes necessary to vary the thread diameter. It is also necessary to select the initial chaser position depending on the radial size of the pipe to be threaded.

Therefore, a die head as shown in FIG. 5 has been developed as a die head capable of obtaining such an operation (Japanese Patent Application Laid-Open No. 57-66817).

In this die head 1, a transverse groove (not shown) is formed on the back surface of the chaser 2, and elongated blades 3 formed at an angle in the circumferential direction at different distances from the center are engaged with this transverse groove. It matches.
The blade 3 projects from a ring-shaped blade body 4, and the blade body 4 is connected by a lock pin 7 to a blade guide 6 rotatably fitted on the outside of a retaining ring 5. A groove 8 is provided in the circumferential direction in the portion of the outer peripheral surface of the blade guide 6 into which the lock pin 7 is inserted, and furthermore, lock holes 9 are bored at a predetermined interval in the upper end of the groove 8. ing. This lock hole 9 has a shape into which a lock collar 10 that is slidably fitted to the lock pin 7 is fitted, and the lock collar 10 is disposed between the lock knob 11 fixed to the upper end of the lock pin 7. It is pushed into the lock hole 9 by a spring 12 provided. Further, a spring 13 is disposed between the retaining ring 5 and the blade guide 6, and urges the blade guide 6 in the circumferential direction.

On the other hand, a guide groove 15 is formed in the outer peripheral end of the die head body 14 in the axial direction, and a copying body 17 having an inclined surface 16 on the upper surface is slidably mounted in the guide groove 15. The front end of the copying body 17 is connected to an intermediate portion of a bar-shaped release lever 18 that is disposed diametrically on the front surface of the die head main body 14. The release lever 18 is connected by sliding a pin 19 fixed to the front end of the copying body 17 into an elongated hole (not shown) formed longitudinally in the middle part of the release lever 18. This is done by combining the The upper part of the release lever 18 is rotatably fitted onto a pivot pin 21 supported at both ends by a pair of holders 20 fixed upwardly to the die head main body 14. A torsion spring 22 is attached to the pivot pin 21, and one end of the spring is brought into contact with the release lever 18. Also, release lever 1
At the lower part of the die head body 14, there is a rod-shaped stopper 23 disposed in the radial direction at the front center of the die head body 14.
They are rotatably connected via a pin 24. Reference numeral 25 denotes a head projecting from the blade guide 6, and a holder 26 is fitted onto the top of the head 25 in the axial direction of the die head body 14. A bolt 27 is attached to the front end of this holder 26, and this bolt 27 allows the copying rod 28 to be attached to the holder 2.
6 and is fixed to the front end of the holder 26 in a direction perpendicular to 6. An inclined surface 29 is formed at the tip of the copying rod 28 and is in contact with the inclined surface 16 on the upper surface of the copying body 17.

In this die head 1, as the tip of the pipe moves in the axial direction, the release lever 1
The thread cutting operation is performed by swinging the lever 8 and relative movement of the copying body 17 and the copying rod 28 attached to the middle of the release lever 18. To change the size of the taper screw, lift the lock collar 10, move the lock pin 7 circumferentially within the groove 8 of the blade guide 6 while inserting it into the blade body 4, and refit it into another lock hole 9. This is done by wearing the clothes.

[Problems with background technology]

However, in this die head 1,
Since a copying mechanism and a mechanism for selecting a chaser position are provided independently in the circumferential direction of the die head 1, the die head 1 becomes large in size and is complicated to handle. Further, since the blade body 5 and the blade guide body 6 were allowed to move relative to each other, the structure thereof was complicated.

[Purpose of invention]

The present invention has been devised in view of these points, and an object of the present invention is to provide a die head that has a simple structure, is suitable for miniaturization, and is easy to handle.

[Summary of the idea]

The present invention includes a die head body having an insertion hole through which a workpiece to be threaded is inserted, a plurality of chasers held in the die head body so as to be movable in the radial direction and having transverse grooves formed on the back surface thereof; A blade body that is rotatable around the workpiece and has a protruding blade that engages with the transverse groove, and opens and closes the chaser with respect to the workpiece depending on the direction of rotation, and the blade A blade guide body, which is formed protrudingly on the outer periphery of the body and has an arc-shaped guide slot having the same center as the blade body, and is tightened and fixed to the blade guide body at a predetermined position of the guide slot. ,
a copying collar on which a thread cutting guide surface extending in the axial direction of the die head body is formed; a first elastic pressure tool attached to the outer circumference of the die head body and urging the copying collar in the chaser opening direction; It is swingably supported on a pivot pin provided near the blade guide of the die head main body and perpendicular to the axial direction of the die head main body, and one end is engaged with the thread cutting guide surface and the other end is engaged with the thread cutting guide surface. The device includes an opening lever formed to protrude into the insertion hole, and a second elastic force urging the other end of the opening lever in a direction toward the die head body.

[Example of idea]

Hereinafter, the present invention will be explained based on embodiments shown in the drawings.

FIG. 1 is a schematic front view showing an embodiment of a die head of a thread cutting device according to the present invention, and FIG. 2 is a schematic left side sectional view of the die head of FIG.

In FIGS. 1 and 2, the reference numeral 30 represents a die head body, and a pipe 31, which is an object to be cut, is located in the center of the die head body 30.
An insertion hole 32 is provided through which the chaser 33 is inserted, and a plurality of chasers 33 are held movably in the radial direction. A transverse groove (not shown) is formed on the back surface of the chaser 33, and protruding blades 34 that are inclined in the circumferential direction at different distances from the center are engaged with the transverse groove. . This feather 34
is ring-shaped and protrudes from a blade body 36 arranged around a retaining ring 35 (FIG. 2). The blade body 36 is coaxial with the die head main body 30 and can be rotated relative to the die head body 30. For example, when the blade body 36 is rotated clockwise in FIG.
When the chaser 33 is guided by the blades 34 and moved toward the center in the radial direction, and is rotated counterclockwise in FIG. There is.

Further, a blade guide body 37 is provided on the upper side of the outer circumferential portion of the blade body 36 so as to protrude outward. The blade guide body 37 is formed with an arcuate guide hole 38 having the same center as the blade body 36 . Further, the blade guide body 37 includes a copying collar 39 having a substantially cylindrical shape.
(FIG. 2) is located above the die head main body 30 and is attached so that its axis is parallel to the axis of the die head. On the other hand, a lock collar 40 is provided on the opposite side of the blade guide 37.
Then, the lock collar 40 and the copy collar 39
A bolt 41 is inserted into an insertion hole formed in the center of the bolt 41 and extending in the axial direction, and a tightening lever 42 is screwed into a threaded portion 41a (FIG. 2) formed at the tip of this bolt 41. ing. By rotating and tightening the tightening lever 42, the copying collar 39 is fixed at a predetermined position on the blade guide 37. Note that details of the copying collar 39 will be described later.

On the other hand, on the upper side of the outer periphery of the die head main body 30,
A cylindrical body 43 extending along the direction of the guide slot 38
is formed. This cylindrical body 43 is opened on one side in the chaser circumferential direction. Further, a plunger 44 is inserted into the cylindrical body 43 so as to be freely protrusive from the opening. And plunger 4
A coil spring 45 is interposed between the plunger 4 and the cylindrical body 43, and the tip of the plunger 44 always urges the copying collar 39 in the chaser opening rotation direction.

In addition, on the upper side of the outer circumference of the die head main body 30,
A locking protrusion 46 is provided on the chaser opening direction side to limit the rotation angle of the copying collar 39.

On the other hand, a release lever 47 that constitutes a copying mechanism with the copying collar 39 is provided on the front side of the die head main body 30. This release lever 47
includes a swing plate 48 and an adjustment plate 49. The former swing plate 48 has a pivot pin 51 attached thereto with its middle extending across the mounting recess 50.
(Fig. 2). Further, as shown in FIG. 2, the swing plate 48 has a long hole 48a formed at its lower end. The latter adjustment plate 49 is attached to the swing plate 48 by a screw 52 inserted through the elongated hole 48a of the swing plate 48.
The release lever 47 configured in this manner has its upper end abutted against a thread cutting guide surface formed on the copying collar 39, which will be described later, and its lower end abutted against a thread cutting guide surface formed on the copying collar 39.
1 and is radially disposed so as to be engaged with the end of the first end. Further, a coil spring 53 is attached to the pivot pin 51 so as to return the release lever 47 to its original position after swinging.

Next, we will explain the copying collar 39.
As shown in FIGS. 3a and 3b, this copying collar 39
The main body 54, which has a substantially cylindrical shape, is provided with a slide guide portion 55, which has a substantially cylindrical shape, at its base end. Further, a guide surface 56 for straight thread cutting is formed on the upper part of the copying collar 39, and a guide surface 5 for tapered thread cutting is formed on the lower part thereof. The guide surface 56 for straight thread cutting consists of a stepped side surface extending in the axial direction of the copy collar 39, while the guide surface 57 for tapered thread cutting consists of a stepped section extending at a predetermined angle with respect to the axis of the copy collar 39. Consists of sides. The angle that the latter tapered thread cutting guide surface 57 makes with the axis of the copying collar 39 is usually 20°±.
It is said to be 15′. In this copying collar 39, either one of the linear thread cutting guide surface 5 and the longitudinal thread cutting guide 57 is selectively engaged (abutted) with the upper end of the release lever 47. There is.

Next, the operation and effects of this embodiment having such a configuration will be explained.

The pipe 31 is constructed using the die head according to this embodiment.
When cutting a taper thread, first, a die head is attached to a position in front of the chuck of a thread cutting device that is equipped with a chuck that grips the pipe 31 and moves it forward in the axial direction while rotating the pipe 31. Next, the pipe 31 to be threaded is gripped by the chuck. Also, depending on the size of the pipe 31 to be threaded,
The copying collar 39 is tightened and fixed to the blade guide 37 at a predetermined position in the guide elongated hole 38 . Next, the copying collar 39 and the blade guide 37 are integrally rotated in the chaser closing direction against the biasing force of the coil spring 45, and the tapered thread cutting guide surface 57 of the copying collar 39 and the upper end of the release lever 47 are connected. bring it into contact.

After making such adjustments, the chuck rotates the pipe 31 and moves it forward in the direction of the die head. As a result, the tip of the chaser 33 cuts a thread groove on the outer peripheral surface of the pipe 31, but at the same time, the tip of the pipe 31 cuts the opening lever 4.
The lower end of the die head 7 is pushed out from the die head main body 30 in the axial direction. And this release lever 47
The opening lever 47 swings about the pivot pin 51 by moving the lower end of the lever 47 in the axial direction. At this time, since the copying collar 39 is urged in the chaser opening rotation direction by the coil spring 45, the tapered thread cutting guide surface 57 of the copying collar 39 is always pressed against the upper end of the release lever 47.
Therefore, as the release lever 47 swings, the copying collar 39 moves in the chaser release rotation direction by the biasing force of the coil spring 45, so that the blade guide 4
0 and the blade body 36, the blade 34 moves to a position where its inclined surface increases the distance from the center of the die head, gradually moving the chaser 33 outward in the radial direction. Thus, a tapered thread is threaded on the outer periphery of the pipe 31.

Further, when the release lever 47 is further swung and the engagement between the release lever 47 and the copying collar 39 is released, the copying collar 39 is rapidly moved in the chaser opening rotation direction by the action of the coil spring 45. The blade guide body 37 and the blade body 36 are simultaneously rapidly rotated in the chaser opening rotation direction. This results in
the chaser 33 is suddenly moved radially outward;
The chaser 33 is pulled away from the outer peripheral surface of the pipe 31, and the thread cutting operation is completed.

After the pipe 31 is threaded, loosen the check and remove the pipe 31. As a result, the tip of the pipe 31 separates from the release lever 47, and the release lever 47 swings back to its original position due to the action of the torsion spring 53.

On the other hand, when cutting a straight thread in the pipe 31,
Thread cutting is performed by bringing the linear thread cutting guide surface 56 of the copying collar 39 into contact with the release lever 47.
In this case, the copying collar 39 does not move in the circumferential direction as the release lever 47 swings. Therefore, the blade guide body 37 that holds the copying collar 39,
The blade body 36 integrally formed with the blade guide body 37 is also not rotated. No radial movement of the chaser 33 takes place.

In addition, when changing the length of thread cutting, change the mounting position of the adjusting plate 49 of the release lever 47 to the swing plate (48), thereby adjusting the thread cutting guide surfaces 56, 5.
7 and the release lever 47 may be changed.
For example, in FIG. 2, if the adjustment plate 49 is moved toward the die head main body 30 and attached to the swing plate 48, the thread cutting guide surfaces 56, 57 and the release lever 4
Since the contact width with 7 becomes smaller, the length of the thread cut formed becomes smaller.

According to this embodiment configured in this way, the following effects can be obtained.

That is, in this embodiment, since the copying mechanism and the mechanism for selecting the chaser position are integrated, the die head is downsized and easy to handle. Furthermore, since the blade body 36 and the blade guide body 37 are integrated, the portions that move relative to each other are reduced.
Therefore, its structure is simple. Furthermore, a linear thread cutting guide surface 56 and a tapered thread cutting guide surface 57 are formed at the upper and lower portions of the copying collar 39, and since these are selectable, the application range of the die head is widened.

In this embodiment, the copying collar 39 is formed with a guide surface 56 for cutting a straight thread and a guide surface 57 for cutting a tapered thread. However, the copying collar of the present invention is not limited to such a structure. Either one of the thread cutting guide surface 56 or the tapered thread cutting guide surface 57 may be formed.

Further, FIG. 4 shows another release lever 47 used in the die head of this embodiment, in which the swing plate 5
An adjustment body 59 is attached to the lower side of 8 via a screw 60. A recess is formed on the lower side of the adjusting body 59, and the recess defines contact pieces 59a and 59b having different widths.

When using this release lever 47, the abutment pieces 59a, 59
If you select one of b as appropriate, you can use it. For example, when using the abutting piece 59b in FIG. 4, the screw 60 may be loosened and the adjusting body 54 may be rotated 180 degrees around the axis of the screw 60. In this case, the width of the contact between the thread cutting guide surfaces 56, 57 and the release lever 47 is larger than that when the contact piece 59a is used, so the length of the thread cutting that is formed becomes larger. .

(Effects of the invention) As explained above, the invention consists of a die head body in which an insertion hole is formed through which the workpiece to be threaded is inserted, and a transverse groove on the back surface of the die head body, which is held movably in the radial direction. A plurality of chasers are provided with blades that are rotatable around the workpiece and that engage with the transverse groove, and are provided with protruding blades that are rotatable around the workpiece, and that move the chasers toward the workpiece according to the direction of rotation. a blade body that opens and closes with respect to the blade body; a blade guide body in which an arcuate guide hole is formed protruding from the outer circumferential portion of the blade body and has the same center as the blade body; a copying collar which is tightened and fixed at a predetermined position of the guide slot and has a thread cutting guide surface extending in the axial direction of the die head body; A first biasing tool is swingably supported on a pivot pin provided in the vicinity of the blade guide of the die head body and perpendicular to the axial direction of the die head body, and one end thereof is connected to the threaded die head body. a release lever formed to be engaged with a guide surface and whose other end protrudes into the insertion hole; and a second release lever that urges the other end of the release lever in a direction toward the die head main body. Since it is equipped with a pressing tool, it has the following effects.

That is, since the copying mechanism and the cheeser position selection mechanism are integrated, the die head can be downsized and its handling can be facilitated. In addition, since the blade body and the blade guide move integrally, there is no relative movement between them, and therefore, compared to a conventional die head in which there is relative movement between the blade body and the blade guide, its structure is It becomes simple.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing an embodiment of the die head of the thread cutting device according to the present invention, FIG. 2 is a left side cross-sectional view of the die head in FIG.
Figures a and b are perspective views of the copying collar of the die head shown in Figure 1, Figure 4 is a schematic configuration diagram of another release lever attached to the die head shown in Figure 1, and Figure 5 is a partially cutaway view of the conventional die head. FIG. 30...Die head body, 31...Pipe, 3
2...Insertion hole, 33...Chiesa, 34...Blade, 36...Blade body, 37...Blade guide body, 38
... Guide slot, 39 ... Copy collar, 45 ... Coil spring, 47 ... Release lever, 53 ... Torsion spring.

Claims (1)

[Claims for Utility Model Registration] 1. A die head body formed with an insertion hole through which a workpiece to be threaded is inserted, and a plurality of die head bodies held movably in the radial direction and having transverse grooves formed on the back surface. a blade body that is rotatable around the cut object and has protruding blades that engage with the cross groove, and opens and closes the chaser with respect to the cut object according to the direction of rotation; a vane guide body having a circular arc-shaped guide slot formed protruding from the outer circumferential portion of the vane body and having the same center as the vane body; a tracing collar which is tightened and fixed and is formed with a thread cutting guide surface extending in the axial direction of the die head body; and a first tracing collar which is attached to the outside of the die head body and biases the guiding collar in the chaser opening direction. The pressing tool is swingably supported on a pivot pin provided near the blade guide of the die head body and perpendicular to the axial direction of the die head body, and one end engages with the thread cutting guide surface. and a second elastic member for urging the other end of the release lever in a direction toward the die head main body. A die head for a thread cutting device featuring: 2. A practical use characterized in that the copying collar is formed with thread cutting guide surfaces for tapered thread cutting and linear thread cutting, and these thread cutting guide surfaces are configured to be selectively engageable with a release lever. A die head for a thread cutting device according to claim 1 of the patent registration claim.