RU121767U1 - DEVICE FOR ROLLING HOLES - Google Patents

Abstract

A device for knurling holes, containing a cylindrical knurled head, guide bushings for entering the knurling head into the workpiece, which form a closed cavity with the surface to be processed, inside which there are balls magnetized by the knurled head made of high-strength hardened steel, upper and lower limiting elements that protect the balls from falling out from the knurled head in the axial direction.

Description

The invention relates to metal working and, in particular, to knurling heads for forming a surface microrelief.

A device for processing internal cylindrical surfaces is knurling (rolling) (A.S. 2285606 Popandopulo K.X., Usov V.V., Lichkovaha A.S.). Rolling for finishing processing of inner cylindrical surfaces), consisting of a loading device and two conical guides, on the cones of which balls are rolled. One of the conical guides is rigidly connected to the thrust of the load device, and the second is mounted with the possibility of longitudinal movement along it. Conical guides are located at an angle to a plane perpendicular to the axis of the thrust of the load device.

This design works as follows: due to the rotation of the rod around its axis, the conical guides also rotate, the action of which on the balls contributes to the rolling of the latter along an inclined section of the surface to be treated. Only part of the balls interacts with the surface to be treated, and the degree of introduction of each of them into the body of the surface being treated is different. Moreover, each of the balls twice during the movement in orbit gradually comes into contact with the treated surface and also gradually leaves it, providing a gentle processing mode with minimal tangential stresses, which makes it possible to vary the deformation force over a wide range.

The disadvantages of rolling is low productivity, since only part of the balls interacts with the surface to be treated.

Another well-known device is a device (Patent No. 2411118 Stepanov, Yu.S., Kirichek A.V.), comprising a housing in the form of a disk with radial deaf sockets in which deforming balls are located, a separator in the form of a ring with holes mounted on the periphery of the disk and pneumatic chamber. The housing is rotatable, and a flange is located at its end. The pneumatic chamber is mounted on the end of the housing in the flange using a bearing from the condition of ensuring its immobility during rotation of the housing. Holes are made in the bottom of the radial disc seats for connecting them to a pneumatic chamber. A groove in the form of a sector is made in the wall of the pneumatic chamber adjacent to the end face of the housing to provide open access for compressed air from the pneumatic chamber to several radial nests with deforming balls located in and close to the processing zone.

During operation, the elements (balls) are shifted in the radial direction under the action of centrifugal force and additional force R. Due to the value of h, an interference is created during processing. The case with elements rotates at high speed. At the same time, the elements inflict numerous blows on the surface of the part, plastically deforming the surface, and do not instantly bounce from it, but are pressed by the force P to the treated surface, preventing the elements from striking the bottom of the nests. This device is selected by the authors as a prototype.

The disadvantages of this device are the complexity and material consumption of the knurling structure due to the presence of a separator, in addition, sliding friction is present between the separator and the balls, which causes additional wear of the balls and energy costs.

The technical result of the utility model is to simplify the design of the knurling head, increase productivity and reduce energy consumption.

The technical result is achieved by the fact that the housing is cylindrical with upper and lower bounding elements and guides that form a closed cavity with balls on the surface to be machined.

The technical result is illustrated by the figures.

Figure 1 shows a General view of the knurling head; figure 2 processing scheme of a single ball (indenter).

The device comprises a knurling head 1, which enters the workpiece 2 through the guide bushings 3. Balls 4 made of high-strength hardened steel (for example, ШХ15) are magnetized by the head to hold them outside the guides. The limiting elements 5 prevent the balls 4 from falling out in the axial direction.

The device operates as follows: the knurling head 1 magnetizes the balls 4 (indenters) to prevent them falling out of the guide elements. After the knurling head has entered the guide sleeve, the reciprocating and rotational movements are communicated to it. Balls 4 having entered the workpiece, begin to roll freely on the work surface, crushing the stock and forming a microrelief and the surface of the knurling head. When the knob moves downward, the upper bounding element protects against axial loss, and when moving upward, the lower bounding element protects it. At the end of processing, the knurling head leads upward from the hole being machined - the balls are kept from falling out by magnetization of the head material.

To process the internal surfaces of parts in order to improve their quality and life, to apply a specific pattern (profile) to critical parts, for example, the internal surfaces of a cylinder block of a car, special methods are used: honing, knurling with special devices. The proposed utility model can replace both the honing process and knurling with other heads. As an example, processing can be performed on a 3M82 honing machine, with the following processing modes: peripheral speed of rotation of the machine spindle 0.5-0.58 m / s, reciprocating speed 0.2-0.25 m / s, time machining - 30 s, machining allowance of 0.02-0.1 mm The diameter of the balls (indenters) is 2 mm.

The proposed utility model allows balls (indenters) to move along an arbitrary trajectory on the surface being machined in the direction of least resistance - the principle of self-organization of systems (synergetics). The indenter himself “chooses” the optimal trajectory of his movement. The design of the knurling head is simplified and the coefficient of friction is sharply reduced due to the absence of a separator.

Claims (1)

A device for knurling holes containing a cylindrical knurling head, guide bushings for the knurling head to enter the workpiece, which form a closed cavity with the surface being machined, inside which are high-strength hardened steel balls magnetized by the knurling head, upper and lower limiting elements protecting the balls from falling out from the knob in the axial direction.