SU917941A1 - Self-centering chuck - Google Patents

Description

(54) SELF-CENTERING CARTRIDGE

one

The invention relates to mechanical engineering, in particular, to tooling metal-cutting machine tools, and can be used to install and process precise parts such as rotary bodies on turning and grinding machines, for example, when threading grinding roller screw gears.

Known self-centering cartridges containing.casing, separator with balls, which are wedged on a cone, the centerpiece and clamping the product when the separator 1 is forced to move.

It is also known a device, in the annular channels of the casing of which a separator with balls is placed, and in the mechanical grooves - clamping elements 2. This device is taken as a prototype.

In the device of the prototype, at the moment of pinching between the conical surface, the part and the separator, instead of rolling the balls cleanly, they slide with considerable effort. In this case, intense rapid wear of the balls and working surfaces occurs, as a result of which the accuracy of centering after

several such installations are lost, which is unacceptable when machining high-precision parts.

The purpose of the invention is to increase the durability of the cartridge.

This goal is achieved by the fact that the cartridge is provided with an axially and axially displaced lever placed in a step-like guide arranged in the housing,

10 of two parts, one of which has a curvilinear section protruding beyond the body of the cartridge, and is connected to the second with the possibility of adjustment in length; while on the front end of the separator is made a groove.

FIG. 1 shows a longitudinal section of a self-centering cartridge; in fig. 2 - view A of FIG. one; in fig. 3 is a section BB of FIG. one.

20 A self-centering cartridge includes a housing 1, in the exact opening of which a separator 2 with balls 3 is placed, which are located in annular channels 4. On one side of the housing there is a flange 5, on the other, a clamp 6 connected to the housing with a nut 7 and a stud 8 .

The housing has a stepped guide, formed by a longitudinal 9 and 10 radial holes. A lever 11 is installed in the longitudinal opening 9 with the possibility of longitudinal and angular movement protected from rotation by the shank of the screw 12. One part of the lever has a curved section extending beyond the housing I, and a radius end 13 which enters the groove 14 at the front end of the separator 2.

At the threaded end of the lever 11, the tip 15 is mounted, protected from self-unscrewing by the spring 16. In the radial hole 10, there is a hinged lever 17, which is acted upon by the spring 18 placed in the plug 19.

The separator 2 is axially spring-loaded by a spring 20 with a tip 21. In the housing 1 and the separator 2 there are coincident windows 22.

The workpiece 23, for example, a ball nut, is inserted into the space between the balls 3. The flange 5 is the stop and a part for fastening the entire cartridge to the machine faceplate (not shown).

The cartridge works as follows.

In the absence of parts 23, the separator 2 under the influence of the spring 20 occupies the extreme right position. In this case, the balls 3 are located in the channels 4, the lever 11 is also in the extreme right position, and its tip 15 is in the longitudinal hole, the lever 17 is rotated in the radial hole 10 by the action of the spring 18 until it stops against the wall. The nut 7 is pressed, the clamp b is turned down. When the part 23 is installed, it freely passes between the balls 3, which are grooved into the channels 4, until the shoulder of the part 23 resists in the convex curvilinear section of the lever 11. Under the pressure of the part 23, the lever 11 begins to move progressively in the stepped hole. At the same time, the radius end 13 of the lever 11, located in the end groove 14, presses on the end face of the separator 2, which also begins to move along the axis, dragging the balls 3 from the annular channels to the working surface of the cylindrical opening of the housing 1.

At the moment of rolling out the balls 3 onto the working surface of the housing, a friction bond arises between the outer surface of the part 23, the balls 3 and the inner surface of the housing. Due to the radial tension in this joint, the balls 3 begin to roll without slipping. The speed of axial movement of the separator 2 is halved compared to

speed of the pushing collar of the detail installed in the cartridge. The position of the tip 15 is precisely adjusted at the threaded end of the lever 11 so that at the moment the balls roll out of the channels 4 onto the working surface of the housing opening 1, the tip 15 slides into the opening 10, and the angular rotation of the lever 11 begins instead of its translational motion. Therefore, the axial pressure of the collar of the part 23 through the lever 11 to the end of the separator 2 stops.

Thus, despite the speed of movement of the separator with balls reduced by two times, the latter go without sliding, since they do not experience any axial pressure from the part. The lever 17 rotates and compresses 18, which creates an ejector force on the tip 15, which is necessary for the subsequent return of the lever 11 after removing the part 23.

Due to the presence of the window 22, the ball cartridge makes it possible to additionally expose the oval window 23 at the corner, without disturbing its centering, which is necessary when threading the ball nuts from the window and thread positioning conditions. Zazhi.mov mrzhet be a few.

The technical and economic effect of the invention is to increase the durability of the cartridge in accuracy.

Claims (2)

1. The patent of Germany No. 2048783,. 49a 7/06, published 1970. 2. Drawing. Sh., Odes80X10 Sky Plant Precision Machines, 1979 (prototype). 1 191817Yu 5 fug.