JPS6140436Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thread cutting device that is attached to a lathe, particularly a bench race, and is suitable for cutting relatively short threads at the end of a material.

Conventionally, thread cutting has been performed by feeding a cutting tool at a constant speed based on a feed screw built into a lathe. To change the thread pitch, the gears are changed to change the ratio between the rotation of the workpiece and the feed speed of the cutting tool. For this purpose, many replacement gears are prepared. This was necessary, expensive, and the work of replacing gears was troublesome. As a result, general bench laces do not have feed screws or the like and cannot be threaded. There is also a bench race that is specially equipped with a feed screw or feed cam so that thread cutting can be performed, but this device requires a large number of feed screws or feed cams to accommodate changes in pitch. This was necessary, and it was very expensive and the work of changing the pitch was very troublesome.

Therefore, the present applicant has developed a case that rotatably supports the feed screw shaft, and also supports the sliding member connected to the cutting device in a slidable manner, and also allows the case to be removably screwed into the feed screw shaft. By connecting the half nut device and the sliding member with an adjustment link member and moving the link member to change the link ratio of the connecting point of the half nut device and the sliding member to the pivot pin, the pitch can be adjusted steplessly. We proposed a thread cutting device that can be modified very easily and can cut any pitch of threads, regardless of whether they are metric threads, inch threads, or worm threads (see Japanese Patent Application No. 79273/1983).

By the way, since this thread cutting device is configured such that the half nut device and the sliding member move together through a link member, the lateral feeding of the sliding member is started at the same time as the half nut device is engaged, and the half nut device is Because a sudden load is applied to the device, the half-nut device may not mesh smoothly with the feed screw shaft, and the end of thread cutting must coincide with the end of feed, which may limit the thread cutting stroke. is occurring.

In view of the above-mentioned circumstances, the present invention connects the link member so as to integrally interlock with the half-nut device and interlock with the sliding member so as to interlock only in one direction, and furthermore, the link member is connected so as to interlock with the half-nut device in one direction only. It is an object of the present invention to provide a thread cutting device configured such that a connecting pin of a sliding member and a link member face each other at a predetermined interval, thereby eliminating the above-mentioned drawbacks.

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the thread cutting device 1 is attached to the upper part of the headstock 3 of a general bench race 2 and is used. Become. As shown in FIG. 2, a main shaft 7 is rotatably supported by a bearing on the headstock 3 of the bench race 2, and a motor (not shown) is connected to the main shaft 7 via a belt and a step pulley 9. power is transmitted. Further, a screw hole 10 for attaching the overcut turret or a screw hole for attaching the cover is provided in the upper part of the headstock 3, and the base 11 of the thread cutting device 1 is attached to the screw hole 10 with bolts 12. It is being Further, a power take-off gear 15 is fixed to the main shaft 7 at the outer end of the headstock 3.
On the other hand, a case 17 is mounted on the base 11 of the thread cutting device 1.
is fixed to the case 17, and a feed screw shaft 19 having a predetermined pitch is supported by a thrust bearing 20 so as to be rotatable only by receiving thrust force on one side. Further, a gear 21 is fixed to one end of the screw shaft 19 protruding from the case 17, and the gear 21 is connected to idler gears 22, 23.
It is connected to the power take-off gear 15 via the gear 15, and the rotation of the gear 15 is transmitted while being decelerated. Furthermore, a half-nut device 25 is screwed onto the screw shaft 19, and the nut device 25 is connected to a dovetail 1 formed on the upper cover 17a of the case 17, as shown in detail in FIG.
It has a block 26 which is slidably supported on 7b. The block 26 has a return spring 27
The half nut piece 29 is slidably supported by a pin 30, and has a semicircular hole 26a that covers the feed screw shaft 19. There is. Further, the half nut piece 29 has an arcuate nut portion 29a that can be screwed into the screw shaft 19, and
9a is always urged by the spring 31 in the direction in which the threaded engagement with the screw shaft 19 is released. Also,
A roller pin 32 is fixed to the other side of the block 26, and the pin 32 abuts on the adjustment link block 33 and is held by a holding piece 35 so as to be integrally interlocked. On the other hand, on the back side of the case 17, a sliding block 36 is supported by dovetails 17c so that it can only slide freely, and a connecting pin 37 with a large diameter is implanted in the block 36. Connecting pin 3
A roller 37a is loosely fitted to the tip of the half nut device 7, and as shown in FIG. 2, the roller 37a faces the adjustment link block 33 at a predetermined distance c when the half nut device 25 is in its returned state. Furthermore, a cam follower 39 is slidably supported on the sliding block 36 and is in rolling contact with a cam 38, which will be described later.
The nut portion 29a can be screwed onto the threaded shaft 19 by swinging. On the other hand, the front side of the case 17 has a diagonal shape, that is, 45
A long hole 40 is bored at an angle of about 100 degrees, and a side plate 41 having a dovetail 41a is fixed along the long hole 40. An adjustment sliding plate 42 is provided on the dovetail 41a.
is slidably supported, and a pivot pin 43 that rotatably supports the adjustment link block 33 is fixed to the sliding plate 42. Further, a rod 45 is connected to the upper part of the sliding plate 42 so as to allow only rotation, and the rod 45 projects from the case 17 and extends obliquely upward, and has an adjustment knob 46 fixed at its tip. . Further, the knob 46 has a female thread 46a formed on its inner peripheral surface.
A is screwed into a threaded sleeve 47 fixed to the case 17 to constitute a dial gauge 49.
In addition, 50 in the figure is a stopper that restricts the downward adjustment position of the sliding plate 42. Further, as shown in detail in FIG. 5, the block 26 of the half nut device 25
A locking plate 52 is provided on the lower surface of the
is supported, and the locking plate 52 is supported by the spring 5
3, the locking claw 52a is connected to the half nut piece 2.
9 is biased to lock the downward protrusion 29b, and a contact pin 52b is implanted on the opposite side of the locking claw 52a. On the other hand, a release plate 57 is provided which is guided by a guide rod 55 implanted in the case 17 and is screwed onto an adjustment screw 56 rotatably supported by the case 17. 56, the position of which can be adjusted, and a release protrusion 57 that abuts against the abutment pin 52b.
a and half nut piece protrusion 29b,
It has a forcible release taper 57b for forcibly removing the nut portion 29a from the screw shaft 19. Further, as shown in FIGS. 6 to 8, the sliding block 3
A constant speed motor 59 with a speed reducer is fixed to the outside of the motor 5 via a bracket 36a.
9 drives a camshaft 60 extending across the bracket 36b of the block 36. The camshaft 6
A cam 38 for operating the nut piece 29 of the half-nut device 25 is fixed to the cam 38, and a cam 62 for operating the detent release solenoid 61 of the sliding block 36 is fixed to the tip of the cam 38.
A cutting cam 63 is fixed to the protruding tip of b. Further, the sliding block 36 extends in a bent manner along the side surface of the case 17, and a cutting table 66 constituting the cutting device 6 is slidably supported by a dovetail 65 on the side portion 36c of the block. The cutting table 66 is urged upward by a spring 67 (see FIG. 1), and has a lug 66a protruding from its rear side surface. On the other hand, a cutting arm 69 is rotatably supported on the sliding block 36 by a pin 67.
One end thereof is in rolling contact with the cutting cam 63, and the other end is in contact with the lug 66a via an adjustment bolt 70. Further, a cutting tool holder 71 is slidably supported on the side surface of the cutting table 66 by a dovetail 66b, and the holder 71 is also slidably supported by a dovetail 66b.
Its position is adjusted and fixed by a fine adjustment knob 72 having a screw rotatably supported by a bracket 66c fixed to the upper end of the cutting table 66. Furthermore, as shown in detail in FIG.
A locking plate 73 for preventing the sliding block 36 from returning is disposed at the lower end of the block 6 so as to be rotatable by a pin 75 and biased by a leaf spring 76 to a predetermined position where it comes into contact with a pin 77. The locking plate 73
At the end of cutting, that is, when the lateral movement of the sliding block 36 is completed, it engages with a locking pawl 79 fixed to the case 17 to hold the sliding block 36 and therefore the cutting table 66 in that position, and to stop the cutting. Simultaneously with the completion of the cut by the cam 63, the cam 62 excites the detent release solenoid 61 to release the engagement with the locking pawl 79. Note that the locking pawl 79 has a long hole 79a,
79a, and its position can be freely adjusted by the elongated hole 79a and the fixing bolt 80 according to the thread cutting stroke of the workpiece. Also, 81 in the figure
82 is a return spring tensioned between the sliding block 36 and the case 17, and 82 is in the return position, that is, when the connecting pin 37
This is an adjustment stopper that regulates the position to be at a predetermined position where it faces at a predetermined distance c. Further, 83 is a handle for manual cutting operation, furthermore, in FIG. 1, 85a is a start switch for the motor 59, 85b is an emergency stop switch, and 86
is a cutting tool attached to the cutting tool holder 71.

Since the present embodiment has the above-described configuration, the thread cutting device 1 is mounted on the headstock 3 of a general bench race 2, and the base 11 is attached to the mounting screw hole 10 of the overcut tool rest using bolts 12. It can be easily installed by fixing the Further, by attaching the power take-off gear 15 to the main shaft 7, the feed screw shaft 19 can be interlocked with the main shaft 7. In this state, when a workpiece is chucked onto the main shaft 7 of the bench race 2 and the main shaft 7 is rotated, the rotation of the main shaft 7 is reduced to 1/6 through the power take-off gear 15, idler gears 23, 22, and gear 21. The speed is reduced and transmitted to the feed screw shaft 19. In this state, when the start switch 85a is pressed, the motor 59 rotates, and the camshaft 60 is further rotated, causing the cam 38 to push the half nut piece 29 of the half nut device 25 through the follower 39 against the spring 31. Then, the nut portion 29a is screwed onto the screw shaft 19. At the same time, nut piece 2
The protruding portion 29b of 9 is caught on the locking pawl 52a of the locking plate 52 by the spring 53, and the nut portion 29a
It is held so that it is securely screwed onto the screw shaft 19. Then, as the screw shaft 19 rotates, the half nut device 25 moves to the right in FIG. Rotate. At this time, at the beginning of the movement of the half nut device 25, the link block 33 is moved at a predetermined interval c.
Therefore, the connecting pin 37 does not come into contact with the roller 37a,
No load is applied to the nut device 25, so the nut portion 29a meshes smoothly with the screw shaft and can be started easily. After the nut device 25 has moved a predetermined amount, the link block 33 comes into contact with the roller 37a, and the sliding block 36 is moved to the left against the spring 81. As a result, the cutting table 66 and the cutting tool holder 71 move together with the block 36, and the cutting tool 86 cuts into the workpiece by a predetermined cutting amount based on the cutting cam 63 to perform the first thread cutting. At this time, a load is generated in the feeding direction due to thread cutting, but the roller 37a of the connecting pin 37 and the roller pin 3 are attached to one side of the link block 33.
2 are in contact with each other, the load can be reliably received, and furthermore, the load acting on the screw shaft 19 via the half nut device 25 can also be reliably received by the thrust bearing 20.
Then, at the same time that the first stroke of thread cutting is completed, the pressure on the half nut piece 29 by the cam 38 is released, and the contact pin 52b of the locking plate 52 contacts the release protrusion 57a of the release plate 57, so that the locking plate 5
2 against the spring 53 to release the locking of the nut piece protrusion 29b by the locking pawl 52a. As a result, the half nut piece 29 is swung by the spring 31, and its nut portion 29a is unscrewed from the threaded shaft 19, and the half nut device 25 is returned to the initial predetermined position by the spring 27. At this time, if the nut part 29a is bitten by the screw shaft 19 and the nut piece 29 is not returned by the biasing force of the spring 31, the half nut device 25
As the nut advances further, the nut piece protrusion 29b releases the release plate 5.
7, and the protruding portion 2
9b is forcibly expanded to release the engagement of the nut portion 29a. Then, as the half nut device 25 returns, the link block 33 locks the holding piece 35.
The sliding block 36 is returned to one piece by holding the roller pin 32 by the locking plate 73.
9, it is left at the lateral feed end position. Then, the cutting cam 6 is driven by the motor 59.
3 rotates a predetermined angle and the arm 69 enters the recess d, the cutting table 66 is returned upward by the spring 67, and at the same time the cutting tool 86 is returned to the non-cutting position, the cam 62 activates the detent release solenoid 61. The magnet is energized to rotate the locking plate 73 against the leaf spring 76 to release the hook from the locking claw 79. Then, with the cutting tool 82 returned to the non-cutting position, the sliding block 36, therefore the cutting table 66, and the cutting tool holder 71 are moved to a predetermined position by the spring 81, that is, the connecting pin 37 is separated from the link block 33 by a predetermined distance c. and returned to a position facing each other. Then, the cutting cam 63 further rotates, and the arm 6
9 reaches the cutting land portion for the second stroke, and with the cutting table 66 lowered to the cutting amount for the second stroke, the half nut piece 29 of the half nut device 25 is again screwed into the screw shaft 19 by the cam 38, and as described above, Similarly, the sliding block 36 is moved to perform the second thread cutting process. In this way, thread cutting is performed a predetermined number of times, and when the final stroke of thread cutting is completed, the rotation of the motor 59 is stopped by a limit switch (not shown), and the thread cutting of the workpiece is completed.

To adjust the screw pitch, the adjustment knob 46 constituting the dial gauge 49 is rotated in accordance with the scale and set at a predetermined position. Then, the sliding plate 42 is moved along the dovetail 41a via the rod 45, and the sliding plate 4 is moved to the setting position corresponding to the knob 46.
Adjust and fix 2. As a result, the sliding plate 42
The adjustment link block 33 is moved via the pivot pin 43 fixed to the half nut device 25 to change the link ratio l ₁ :l ₂ from the pivot pin 43 to each pin 32, 37, thus changing the By changing the feed amount of the sliding block 36 relative to the feed amount, the thread pitch can be arbitrarily changed and adjusted regardless of whether it is a metric thread or an inch thread. In addition, at this time,
Since the sliding plate 42 is inclined at an angle of 45 degrees, the amount of movement of the sliding plate 42 can be adjusted using the link block 3.
The link ratio l ₁ :l ₂ of 3 can be increased by a factor of √2, making it possible to make fine adjustments easily and reliably, and when adjusting the screw pitch, that is, when the half nut device 25 is in the returned state. , since the link block 33 is at the same inclination as the adjusting movement direction of the sliding plate 42, the link block 33
Due to the movement of the connecting pin 37 and block 33,
Since the predetermined interval c does not change and the pin roller 37a and block 33 are not in contact with each other,
The link block 33 can be easily adjusted and moved.

As explained above, according to the present invention, the case 17 rotatably supports the feed screw shaft 19, the sliding member 36 connected to the cutting device 6 is slidably supported, and the feed screw shaft A half nut device 25 and a sliding member 3 that can be removably screwed into the half nut device 19
6 are connected by an adjustment link member 33, and the link member 33 is further moved to change the link ratio of the connection points 35, 37 of the half nut device 25 and the sliding member 36 with respect to the pivot pin 43. Therefore, the screw pitch can be changed and adjusted steplessly.
The adjustment link member 33 can be integrally linked with the half nut device 25, and can cut any type of thread including metric threads, inch threads, worm threads, and taper threads, and can adjust the thread pitch extremely easily. Sliding member 3
6 and are connected so as to interlock in only one direction, and furthermore, in the return position of the half nut device 25, the connecting pin 37 of the sliding member and the link member face each other with a predetermined distance c, When the half-nut device 25 is started, no load is applied to the nut device, the meshing with the feed screw shaft 19 is made smooth, and the half-nut device 25 can be started reliably.
Furthermore, when thread cutting is finished, only the half nut device 25 can be returned, leaving the sliding member 36 behind, and any thread cutting stroke within a predetermined range can be efficiently cut without damaging the cut thread by returning the tool. .

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a state in which a thread cutting device according to an embodiment of the present invention is attached to a bench race, and FIG.
3 is a sectional view taken along the line in FIG. 2, FIG. 4 is a sectional view taken along the line in FIG. 3, FIG. 5 is a view of the half nut device and release plate seen from below, and The figure is a plan view of the device, FIG. 7 is a rear sectional view thereof, and FIG. 8 is a side view thereof. 1... Thread cutting device, 2... Bench lace, 5
...Transverse feed device, 6... Cutting device, 17... Case, 19... Feed screw shaft, 25... Half nut device, 32... Connection point (roller pin), 33...
...Adjustment link member (block), 36...Sliding member (block), 37...Connection point (pin), 43...
...Pivot pin, c...predetermined interval.

Claims (1)

[Claims for Utility Model Registration] Consisting of a feeding device and a cutting device, a feed screw shaft is rotatably supported in a case, and a sliding member connected to the cutting device is slid in the axial direction of the feed screw shaft. The adjustment link member is rotatably supported by a pivot pin in a plane parallel to the axial direction of the feed screw shaft and the sliding direction of the sliding member, and is engaged with and disengaged from the feed screw shaft. A half nut device is freely screwed together, the half nut device and the sliding member are connected by the adjustment link member, and the link member is further moved to establish a connection point between the half nut device and the sliding member with respect to the pivot pin. In the thread cutting device configured to be able to change the link ratio of the half nut device, the adjustment link member is connected to the half nut device through an elongated hole and a pin, and is connected to the connecting pin of the sliding member. A feeding device for a screw cutting device, which is configured such that the connecting pin of the sliding member and the adjustment link member face each other at a predetermined interval in a return position of the half nut device.