SU984709A1 - Trepanning drill apparatus - Google Patents

Description

(5) DEVICE FOR RING DRILLING

 The invention relates to metal cutting and can be used to make deep holes in difficult-to-cut materials. A device for hole drilling is known, comprising a chuck for fastening a part, a rotatably mounted center, provided with a shank for mounting in a tailstock and a supporting hole drill bit; 11. A disadvantage of the known devices is that at the end of the drilling process, the core cut from the workpiece, lost in connection with the main part, under the influence of the preserved circumferential speed and centrifugal force makes a random motion, striking the tool, which leads to premature failure tool and makes the process unreliable. In addition, the core and the main part need to be repaired to remove the undercut, which is obtained as a flush as a result of the fracture of the machined surface before the tool exits. The purpose of the invention is improving the reliability and durability of the tool. This goal is achieved by TeMj that. The device for hole drilling is provided with an additional spring-loaded center, which is installed in the cartridge coaxially with the main core and opposite to it. FIG. 2 is a general view of a device for hole drilling designed for turning group machines / FIG. -2 is a section A-A in FIG. 1) in FIG. 3 is a general view of an annular drilling device for drilling machines.

The device consists of a two-support centering element 1 and an annular drill bit 2 mating with it by a sliding fit.

A double-support centering element has a shank for mounting it into a tailstock or a revolver head, and on the other hand, a rotating center 3 for placing it in the center hole of the part +. The drill bit 2 is a pipe with a flange that holds it to the body. 5, having a longitudinal through groove, a Bronze spindle sleeve 6 is inserted into the body along a tight fit, while the inner surface of the sleeve is designed so that after installing it into the body, it mates with a two-support center element by sliding fit.

The annular drill 2 assembled with the body 5 and the spindle sleeve 6 are put on the two-support centering element 1, after which the body 5 and the spacing sleeve 6 are compressed with strut bolts 7 to the full relief of the split sleeve of the two-support centering element, while allowing them to move relative to each other in the direction of the longitudinal axis

The double-support centering element 1 is drilled to supply a lubricating cooling fluid to the cutting zone through the nozzle 8. The housing 5 has holes for the drive pins 9 of the holder 10. In the machine spindle 11, a guide sleeve 12 is mounted, in which a spring-loaded center 13 is placed, mated with the guide sleeve along a sliding fit and having the ability to move along the spindle axis within the desired limits. In order to avoid turning the center 13 relative to the guide sleeve 12, pin 1 is pressed into it, which fits into the corresponding groove of sleeve 12,.

Thus, the center 13 can rotate with the spindle 11, and their axes coincide.

The device works as follows.

The pre-centered part is mounted on the center 13 and pressed by the rotating center 3 by pushing the two-support centering element 1 towards the details. whether using tailstock quill or machine turret. In this case, the axis of the ring drill 2 and the axis of the part are aligned with the axis of the spindle, and the double-support centering element gets a firm support through the rotating center 3. The centered part is clamped in the cam chuck 15 to transfer torque to it.

The working feed of the core drill 2 is carried out with the help of a holder 10 fixed in the tool holder of the machine through the driving pins 9. At the end of the cutting process, the main part remains fixed in the three-jaw chuck 15 and the cut-out core is clamped

the center 13 and the rotating center 3, while they perform a synchronous rotation.

When the two-centering element 1 is retracted together with the annular drill 2, the spring 16 expands and moves the center 13, the output cuts the core from the main part, after which it is removed - then the main part is removed,

In FIG. 3, a double-support centering element 1 is associated with a pneumatic cylinder 17 (can be used, a spring mechanism, or any other drive) and has the possibility of longitudinal movement during operation. The body 5 with an annular drill 2 and a split sleeve 6 is fixedly mounted on the table of the machine 18, and the sleeve 6 is pressed through the pressure plate 19 with bolts 20,

f

The device works as follows.

The pre-centered part k is installed on the rotating center 3 and, by lowering the quill with a spindle-split 11, presses it with the center 13 to the rotating center 3. This achieves the alignment of the axes of the double-support centering element 1 with a circular drill 2 and the part C along the spindle axis. The part is then secured in a three-jaw chuck. The two-support centering element 1 with the piston of the pneumatic cylinder 17 is located

Claims (1)

at this time in the extreme upper position. The spindle revolutions and work are included. When moving parts C down, it presses on the double-support centering element 1 and, overcoming the resistance of the pneumatic cylinder 17, lowers it down. At the end of the process of drilling work cut-offs, the Porschet with the double-support centering element returns to its original position, raising the part and machine quill. Next, the machine quinol is raised by the operator, while the cut core is pushed out by the spring-loaded center 13 O and cannot fall out, since it remains fixed between the center 13 and the rotating center 3 until removed by the operator. Then the main part K is removed, the force of the pneumatic cylinder is chosen so that it It ensured the transfer of the required torque from the center 13 to the cut rod in the process of removing the undercut, which is formed at the end of drilling. The feed force of the machine must exceed the axial component of the cutting force and the force of the pneumatic cylinder. Thus, the presence of an additional center allows, prior to final fixing of the part, to press it along the center holes previously made in it and to locate the axis of rotation of the part with the tool axis, which creates favorable conditions for cutting the tool. At the end of the drilling process, when the cut-out core is separated from the main part, it remains in the pressed-down state and rotates with the main part synchronously, keeping the position of its axis unchanged. This eliminates the impact of the core on the tool and prevents it from breaking, and also allows the cutting tool to remove the scarring that forms on the core or main part as a result of destruction at the end of machining the cut lintel when it becomes thin and does not withstand the axial component of the cutting force. Claims An annular drilling device comprising a chuck for fastening a part, a rotatably mounted center, equipped with a shank for insertion into a tailstock and a supporting annular drill bit, characterized in that, in order to increase the reliability and durability of the tool, the device is provided with an additional spring-loaded center , established in the cartridge co-coherently to the main and opposite euu directional. Sources of information, given in the consideration during the examination 1. Scherbakov ON, Edigarov A, C, Kohl Purpose drilling on lathes, - Mashinostroitel, 1977 №9, p. ,