Development of Drilling Tool

Introduction

The intensification of production in mechanical engineering is inextricably connected with the technical re-equipment and modernization of production based on the application of the latest achievements in science and technology. Technical re-equipment, preparation of production of new types of mechanical engineering products and modernization of production facilities inevitably include the processes of designing technological equipment and their manufacture.

In the total amount of technological equipment, about 50% are machine tools. The use of machine tools allows:

1) reliably base and secure the machined part with preservation of its stiffness during machining;

2) stable provision of high quality of machined parts with minimum dependence of quality on qualification of the worker;

3) increase productivity and facilitate working conditions of the worker as a result of mechanization of devices;

4) to expand technological capabilities of the used equipment.

There are a number of requirements for the efficient use of machine tools and machine tools.

To ensure high accuracy of workpieces processing, accessories must be made with high accuracy. Basing and anchoring errors shall be minimized. The design of the tool shall not be the most flexible link of the tool-tool-tool-part system in order to use the full capacity of the machine in draft operations and to ensure high accuracy in finishing operations. The tool shall provide good tool accessibility, i.e. the ability of the tool to approach as many workpiece surfaces as possible. The fixtures shall reduce the clamping time of the workpiece. In order to reduce the time for re-installation of machines, the devices should provide the possibility of their quick change or re-installation.

The purpose of this work is to develop a machine tool for processing holes of the "Cup" part in a drilling operation.

1. Technical characteristics

Eight 15 + 0.27 mm diameter holes and three 10 + 0.22 mm diameter M12 thread holes shall be designed (step 040).

The workpiece is machined on a 2L53U radial drilling machine using a conductor. The use of a specialized device (PR) will reduce the labor intensity of processing at this operation, reduce piece time, and increase the stability of the accuracy parameters of the operation.

Overall dimensions of the conductor 260x173 mm.

Bushing material: Steel U10 GOST 143599, plates: Steel 20X GOST 454371.

In this case, a cover conductor (conductor with removable cover) is used. The accessory consists of two parts: the upper - is decorated as an overhead conductor, the lower - a support.

The part is placed between the conductor bushing located above it and the installation place adjacent to the table. The upper part of the conductor (conductor plate) is connected to the lower stud.

In order to guide the cutting tool, conductor sleeves are provided in the conductor body, which ensure accurate processing of the holes in accordance with the drawing. The design and dimensions of these bushings are standardized. They are:

- permanent - used in conductors for small-scale production when treating the hole with one tool;

- quick shifting with a lock - in conductors for mass and large-scale production.

The bushings are made of U10 or 20X steel and heat treated to give them the necessary hardness.

To reduce wear of bushings and decrease displacement of axis of processed hole due to possible skew of tool in bushing, clearance is left between its lower end and surface of blank. Then the chips do not pass through the bushing, but are dropped to the side. When drilling cast iron, clearance is taken from 0.3 to 0.5 mm.

When drilling steel and viscous materials (copper, aluminum and other alloys), the gap increases to the size of the diameter.

The correct arrangement of the workpieces to be treated relative to the tool in the conductors is provided by the mounting supports. These include pins and plates.

Pins are used with flat (I), spherical (II) and notched (III) heads. The former are designed to install blanks with treated surfaces, the latter and the third are designed to install blanks with unprocessed surfaces.

Mounting plates are fixed in conductor housing by two or three screws.

If there is an allowance on the surface of the workpiece to be treated, which must be removed in subsequent operations, adjustable supports are used.

Conductor plates are used for installation of conductor bushings in their holes.

Depending on the method of connection to the conductor housing, conductor plates are divided into:

- permanent,

- rotatable,

- volumetric,

- suspended

- lifting.

Permanent plates are made integral with conductor body or rigidly connected to it by welding or screws.

Rotary plates rotate on axis relative to conductor body during installation and removal of machined part.

Removable plates are made separately from housing. Part is fixed in conductor, detachable plate is installed, and after treatment detachable plate is removed.

Suspended conductor plates have two holes along their edges, with which they are installed on lower ends of two guide chips and fixed with nuts. Upper ends of rockers freely enter holes of bushings pressed into holes of housing of multi-spindle drilling head, which is fixed on sleeve of machine spindle.

Lifting conductor plates have two holes along their edges, with which they are installed on upper ends of two guide chips and fixed with nuts. Lower ends of guide chips enter holes of conductor body. Lifting and lowering of guide chips with conductor plate is performed from pneumatic drive.

The use of conductors eliminates the need to mark, place center holes, reconcile workpieces when attaching and other operations related to marking drilling. Therefore, they are widely used in mass production and mass production.