SU679380A1 - Apparatus for abrasive centrifugal machining - Google Patents

Description

The invention relates to the field of finishing a free abrasive and can be used in the bearing industry, in the aviation industry, in the automotive industry and in other sectors of the industry. There are known devices for abrasive centrifugal processing in a rotating drum of parts that receive additional movement by means of air nozzles installed tangentially to the cylindrical surface of drum 1 and the disadvantage of these devices is that frequent impact of balls hinders the quality of their balls. The purpose of the present invention is to improve the quality of machining parts, such as balls. The goal is achieved by the fact that the device is equipped with a cylindrical shell, concentrically installed inside the drum, forming with it a working cavity in which the processed balls are placed, and on the cylindrical surfaces of the drum and the shell, cutouts and notches are made according to the configuration of the balls. and the nozzle holes are made in the shape corresponding to the cut-outs of the cylindrical surface of the drum. Fig. 1 shows the device in cross section; Fig. 2 shows section A-A of Fig. 1, with the cover removed; on fig.Z - section bb of figure 1, rotated (with a different form of parts). A device for centrifugal abrasive machining of ball-like parts comprises a hollow drum 1 mounted rotatably on a stationary shaft 2. On the cylindrical surface of the drum 1 there are notches 3, made in a shape corresponding to the configuration of the parts being machined 4, the latter protruding above the outer cylindrical surface of the drum 1 , to which tangentially or at an angle is installed on the casing of the nozzle 5 for supplying jets of the medium under pressure. For the purpose of uniform interaction of these jets and parts, the shape of tips of nozzles 5 corresponds to notches 3 on the cylindrical surface of the drum. To prevent the workpieces from falling out under the effect of weight forces from the notches 3, a fixed shell 6 installed concentrically with it is provided inside the drum 1, in which a loading window 7 is provided that is closed by the valve 8. The shell 6 has a surface profile that fits the details 4, and the shell is installed. Thus, there is a gap d in its profile and children pressed to the slot.

The bottoms of the workpieces and the abrasive paste (powder) on the end surface of the drum 1 are slotted 9. The space between the inner surface of the drum 1 and the shell 6 forms a cavity 10, which, together with the notches 3, forms the working area. To prevent noise, drum 1 is enclosed in housing 11.

The device works as follows.

In the drum 1, the machined parts 4 are laid. Dp of this, open the valve 8 and combine the loading window 7 of the shell 6 with some cutout 3 in the drum 1. Then, through one of the slots 9 and the loading window 7, lay part 4, and then, aligning the following cuts 3 with boot window 7, install the valve 8 and the casing 11 with nozzles 5.

. When the drum rotates at an angular velocity to in the direction of arrow C along with the parts, the latter are pressed by the corresponding notches 3 under the action of the inertia force. When steady rotation of the drum 1 towards him from the nozzles 5 serves the medium jets under pressure p. In addition to the inertia force, the pressure from the jets undergoes contact with the nozzles 5, and the detals will come out of contact with the walls of the notches 3 and will be jerked off in the direction of the center of rotation, turning under the action of the force of the same jet, directed rio to the tangent surface of the treated the details. Then, as the distance from the nozzle 5 is reached, the children under the action of centrifugal force again press against the corresponding notch 3. With the passage of the subsequent nozzles, the movement of the part is repeated again. Periodic displacement of parts in the direction of arrows F in combination with their rotation around its own axis along arrow E. leads to the interaction of parts with cut surfaces 3.

The processing time of the part is determined by the angular speed and rotation of the drum (4-5 thousand rev / min), as well as the number of nozzles.

During the rotation of the drum 1, the finishing paste is pressed against the inner surface of the drum by the action of inertial forces, and at the moment of separation of the part from the walls of the recess 3 enters the gap between them.

Thus, the rotation of the workpiece occurs in combination with intermittent contact with the walls of the cut-outs 3 in the presence of an abrasive (refining) paste that is constantly in the contact zone. This helps to obtain the necessary parameters and reduce the surface roughness of the workpiece. If necessary, the abrasive powder can be fed through the nozzles 5 together with the pressure medium.

In order to ensure a guaranteed rupture of the contact of the notches 3 with the parts 4 being processed at the time of their passage near the nozzles 5, the angular velocity ijo of the rotation of the drum is selected according to the calculation formula;

. . - JTF llfrb

where p is the pressure of the jet supplied

from the nozzle,

) - the angular velocity of the drum, m is the mass of the workpiece, D is the diameter of the centers of the parts

This inequality can be sustained either by changing the pressure of the jet at a constant value of ω, or by adjusting it at a constant value of p, or by simultaneously adjusting the values of p ia.

After the machining of parts is completed, they are unloaded in the same way as during loading, only all actions are performed in the reverse order.

The device provides processing of the outer surface of parts such as rotation bodies of various configurations, but it is necessary to ensure the appropriate configuration of the notches 3 and the shape of the shell 6.

The use of the proposed invention can significantly improve the quality and performance of machining parts.

Claims (1)

Invention Formula A device for abrasive centrifugal processing in a rotating drum of parts that receive additional movement by means of air nozzles mounted tangentially to the cylindrical surface of the drum, characterized in that, for the purpose of quality processing of parts, such as rotation bodies, for example balls, the device is provided with a cylindrical shell that is concentrically mounted inside drum image with him