SU268871A1 - - Google Patents

Description

The invention relates to machine tools.

The main author's certificate describes a semi-automatic thread-cutting device containing a shaft with a flange bearing a tool holder, on which a multi-stage gearbox and a reversing device rigidly connected to it are mounted. For automatic feeding and removal of the tool from the cutting zone, the tool holder is provided with a slide, the movement drive of which is kinematically connected with the reversing device. The incision of the tool after each pass is provided by means of a ratchet mechanism that interacts with the reversing device by means of a coping disk.

In order to feed the cutter to a plunging at an angle equal to half the angle of the thread profile, the flange of the proposed device is provided with a slider bearing the cutter, the guides of which are inclined to the axis of rotation of the device at an appropriate angle. Periodic movement of the slider to the plunging and retraction during the return stroke is made in the form of a disk stepped cam associated with a ratchet wheel, interacting with the stops located on the fixed case. The gearshift switching mechanism of the gearbox is designed as spring-loaded shtyry, interacting with a cylindrical cam located inside the drive shaft, and the reverse mechanism: complete in the form of two coaxial gears; with an exhaust pin, the plug of which is placed in the closed guide groove of KOf

devices.

FIG. 1 shows a longitudinal section of the proposed device; in fig. 2 - A-A in FIG. one; in fig. 3 shows a section BB in FIG. 2; in fig. 4 - section BB in fkg. 3;

in fig. 5 and 6 - section G-D in FIG. 1 - two positions of cam interaction with a slider.

The device consists of a housing 1 inserted by a conic shank into the spindle

machine tool. On the flange 2 attached to the housing 1, a slider 3 is fixed, carrying the tool holder 4. The slider 3 is installed at an angle to the axis of rotation of the device and is spring-loaded 5 to a disk stepped cam 6 connected to a ratchet wheel 7, which interacts via a spring loaded bar 8 and dog 9 with stops 10 and 11 mounted on housing 1. In order to provide the required thread and change it, the device is equipped with a gearbox consisting of: leading gears 12, 13, driven scissors 14, gear block 15, 16, 17. Mechanism gear switching p The cage is designed as a cylindrical cam 18, internally connected with a roller 20 having a head 21 at the end. The cam 18 interacts with the drive gears 12, 13 of the gearbox by means of spring-loaded pins 22. The reciprocating motion of the cutter is provided by a reversing mechanism consisting of gears 23-24, gears 25-26, tongs 27, spindle 28 placed in the groove of the flange 2 and rigidly connected with the driven gear 14 of the gearbox of the flange 29. From the machine spindle (not shown) rotation is transmitted to housing 1, with which the gear 13 rotates, the gear 16 rotates around its axis, and together with the gear the entire gear block 15-17. At the same time, the gear wheel 15 turns the idle gear 12, and the gear 17 drives the driven gear 14. Change the number of teeth and the drive module 12, 13 and the driven gear 14, as well as the gear unit 15, 16, 17. To change the gear ratio, you need to check the roller head 21 20. By means of the cardan joint of the rollers 20 and 19 through the faceted surface of the latter, rotation is transmitted to the cylindrical cam.

18, having a faceted hole through which the roller makes axial movements

19. The cam 18 with its surface acts on the spring-loaded pins 22, alternately interacting with the grooves of the driving gears 12 and 13.

When moving the driven gear 14, the flange 29 rotates, in the slot of which a key 27 is placed.

In the position shown in FIG. 1, the key 27 is in the groove of the gear 23, which coincides with the groove of the gear 24. Rotating, the flange 29 rotates the gear 23 around its axis by means of the key 27, and through the gears 25, 26 the gear 24 receives the rotation in the opposite direction. After 180 °, the keyways of the wheels 23 and 24 will again coincide, the key 18 will engage with the wheel 24 and lead it in the opposite direction. After 180 °, the cycle is repeated. Together with the wheels 23 and 24, the alternating sign is made by the gear 25 with the lead screw 28. The latter is screwed into the flange 2, which carries the slider 3 with the tool holder 4. At the beginning of movement of the tool holder, a support 10 acts on the spring-loaded pin 8, which also

11, is rigidly connected to the housing 1 and, in one cycle of operation of the reversing device, performs one revolution around the axis of rotation. Under the action of the stop 10, the rod 8 moves to the rotation chain and through the pawl 9 rotates the ratchet wheel 7 together with the cam 6. Once a certain protrusion of the cam 6 is aligned with the corresponding section of the slide 3, the movement of the rod 8 is colored and, when the tool holder 4 is further down, the tool holder 4 cuts into workpiece. Before the start of the reverse, another stop stops And, set in such a way that the rod 8 moves to the center further than the stop 10. The cam 6 rotates, its protrusion diverges from the slider 3 and under the action of the spring 5 the slider is thrown all the way into the hollow. Cam projections are on different

distances from its own axis of rotation, therefore, with each subsequent downward movement of the tool, the tool moves further away from the center of rotation, performed a stepped plunge.

Subject invention

Claims (4)

1. Semi-automatic thread-cutting device according to ed. St. No. 339351, characterized in that, in order to supply a cutting tool for cutting at an angle equal to half the angle the thread profile, the flange is provided with a slider bearing a cutter, the guides of which are inclined to the axis of rotation of the device at an appropriate angle. 2. The device according to claim 1, characterized in that the mechanism for the periodic movement of the slide to the plunging and retraction during the reverse stroke is made in the form of a disk stepped cam associated with a ratchet wheel, interacting with the stops located on the stationary case. 3. The device according to claim 1, characterized in that the mechanism for switching gears of the gearbox is made in the form of spring-loaded pins interacting with a cylindrical cam located inside the drive shaft. 4. The device according to claim 1, characterized in that the reversal mechanism is made in the form of two coaxial gear wheels with an exhaust key, the ton of which is placed in a closed guide slot on the body of the device. 75 14 / E f 19 FIG. 2 26 FS / e 3 Phiez ten Fi / g.