SU1710207A1 - Self-centering lathe chuck - Google Patents

Abstract

The invention relates to a machine tool industry, specifically to devices for securing blanks on a lathe spindle. The purpose of the invention is the expansion of technological capabilities by ensuring the rotation of the cams at angles less than 180 °. In the housing 1 there are slides 2 on which rotary cams 3 are mounted. They are fixed on the semi-shafts 4 and 5 connected by a helical gear. On the slots of the half-shaft 5, the half-coupling-gear 8 is rotatably mounted, and the half-coupling 7 is connected with the half-shaft 5 by a splined connection. Couplings 7 and 8 constitute a cam clutch. On the half-shaft 4, the shoulder-restraint 9 of the stroke and the step 11 entering the cavity of the half-shaft 4 are made. The half-coupling-gear 8 is rotated from the gear 12 connected by a non-braking screw gear with the rod 13. The clamping of the workpiece is carried out by the rod 16 through the wedge mechanism. If it is necessary to rotate the cams 3, air is fed into the left cavity of the cylinder 14. At the same time, the rod 13, moving to the right, turns gear 12 and coupling half-gear 8, Semi-5 gets axial displacement due to the presence of a helical gear connecting half-shafts 4 and 5. However, axial the movement of the half-shaft 5 is limited by the shoulder-restraint 9, therefore the axial movement gets the half-roll 4 until the locking pin 19 comes out of the hole in the cam 3, but the spring-loaded lock-20 keeps it from turning, The half-roll 4 continues to move until the step 11 rests against the inner end of the cavity in half-shaft 4. Thereafter, the resistance of the retainer 20 is overcome and the cam 3 starts turning until the finger 19 is installed against the next slot in the cam 3. This moment coincides with the end of the piston stroke of the cylinder 14 Since the piston stroke is controlled by the stop 21, it is possible for the cam to rotate by an angle smaller than 180 °, which expands the technological capabilities of the cartridge. 1 il.slsoyu XI

Description

The invention relates to a machine tool industry, specifically to devices for securing blanks to a spindle & amping machine.

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The aim of the invention is the expansion of technological capabilities by ensuring that the cams rotate on angles smaller than 180 °.

The drawing shows the proposed cartridge with drives for clamping and rotating the cams, a slit.

The cartridge includes a housing 1 with radially movable sliders 2 and rotatable brackets 1 / cabs 3 located on them, behind- mounted on the semi-rolls 4 (on the right end of the composite shaft). Semi-4 is threaded with a slotted semi-thread by thread.

5, on the slots of which a half-spring 7 is spring-loaded with a spring 6, connected by means of end teeth with a half-gear 8, freely set on the outer diameter of the slotted half-shaft 5. The latter is equipped with a shoulder-restraint 9 of the stroke located between the end of the stepped hole in the slider 2 and the end the guide sleeve 10, pressed into the hole of the slider 2. At the right end of the half-shaft 5 there is a step 11, the diameter of which is larger than the thread diameter. The half-coupling gear 8 of each cam is engaged with the sun wheel 12, which is connected via a non-braking thread to the rod 13 of the cylinder 14 and installed in the bore of the flange 15 between its bottom and the end face of the body 1 of the cartridge. Inside the stem 13 there is a ta-bar 16 of the clamping cylinder 17, associated with a wedge sleeve 18, interacting with sliders 2 of the cartridge. The clamping cams 3 are fixed against rotation by means of a fixed 19 and spring-loaded 20 fixing fingers. The first one is cut and has a cylindrical shape, and the second one has a spherical head. The holes for these fingers, respectively, have a cylindrical and conical shape and are located on different diameters. The number of the first is equal to the number of the second. The number of fixing holes in the cam, i.e. The number of fixed cam positions can be from 2 to 8. Adjustable stops 21 are located in the right wall of the drive cylinder 14. The piston stroke of the drive cylinder 14 is determined based on the guaranteed rotation of the splined yale 5 by 1.5 turns.

The cartridge works as follows.

After completion of the treatment by supplying compressed air to the left cavity of the clamping cylinder 17, the part is unclamped and removed from the cartridge. Next, to rotate the cams 3 to a new position, compressed air is supplied to the left cavity of the drive cylinder 14. At the same time, the rod 13, moving to the right, rotates the sun wheel 12 clockwise (when observed from the toe of the spindle) and the half-coupling gears due to the non-braking thread. 8 is also clockwise. Since the movement of the spline half-ala 5 is axially limited by the shoulder-limiter 9 of the stroke, and the half-4 does not have the ability to rotate, the latter moves to the right as the splined half-shaft 5 rotates until the fixing hole of the clamping cam completely disappears from the fixing pin 19 At this moment, the cam 3 should turn, but the spring-loaded pin 20 holds it from the turn. The half-4, pushing further, reaches the stop on the inner end of the shoulder 11 of the splined half shaft 5. Thereafter, the force of the spring-loaded ltsa 20 is overcome and the cam 3 is rotated to its next condominium conical opening with a spring-loaded locking finger 20..Pri following this cylindrical opening cam positioned against the locking bolt 19. This moment coincides with the end of the stroke of the piston of the cylinder 14 and therefore the cams 3 are rotated no further. The whole process

5, uncoupling the cams takes 1.5 revolutions or less of the splined half shaft 5. In one turn of the last / o, the cam 3 is disengaged from the fcks-finger 19 (its height is somewhat less

0 thread pitch in the connection of the slotted half-shaft 5 with half-shaft 4). The remaining | 2 turns rotate the cam at a maximum angle of 180 ° (double-cam cam rotation). To ensure that the cam lobes are 1/3, 1/4, 1/6 and 1/8 turns, the spline half 5 turns 4/3, 5/4, 7/6 and 9/8 turns, respectively. For this, the piston stroke of the cylinder 14 is controlled by the stops 21,

To fix the cam 3 after their turn, the air is fed into the right cavity of the cylinder, indra 14, and the solar mirror 12 turns in the opposite direction,

5, the spline half 5 also rotates in the opposite direction and, screwing into the threaded hole of the half 4, retracts it. At the same time, the cylindrical opening of the cam matches with the finger 19, and

0, the finger 20 is sunk into the body of the slider 2. The slotted half 5 continues to rotate until the cam 3 is fully tightened to the end of the slider 2. After this, the sun wheel 12 continues to rotate due to the 5th half of the half-coupling-caster 8, which creates a certain moment under the action of the spring 6 zat zhki The rotation of the sun wheel 12 stops when the piston stops in the rear cover of the cylinder 14. The cartridge gear module is selected on the basis that its stroke cams (slide 2) must be less than the full height of the tooth so that the kinematic chain does not break when clamping the part when unclenched

5 half-coupling gears hooks to the full height, providing the necessary strength characteristics when turning and fixing cams.

Thus, the design allows to expand the technological capabilities

by turning it to angles less than 180 °.

Claims (1)

Claims The turning self-centering chuck, comprising a housing, sliders with wedge surfaces and connected with a turning mechanism cams installed in drive shafts placed in sliders, characterized in that, in order to expand technological capabilities by providing turning cams at angles smaller than 180 °, the rotation mechanism of each cam is equipped with a cam clutch consisting of two half-couplings that are spring-loaded relative to each other, and each drive shaft is made of two connected helical gears cottages, one of which contains splines, a shoulder stop, and a protrusion entering the cavity made in the other half, with a gear ring connected to the turn mechanism on one half coupling and this coupling half is mounted on the slots of the semi-shaft with rotation, and in the other half coupling there is a slotted hole designed to interact with the slots of the semi-shaft. 67 W 2 20, ////