Conductor - drawings

Contents

Introduction

1 General information about the fixture

1.1 Purpose and principle of operation

1.2 Conductor Assembly Sequence

2 Technical requirements for parts

2.1 Surface roughness selection

2.2 Material Selection of Parts

3 Surface classification

3.1 Peculiarities of parts connection

3.2 Surfaces

4 Substantiation of selection of fits, limit deviations of dimensions

List of sources used

APPENDIX A

Introduction

Machine tools are additional equipment for metal cutting machines designed to connect workpieces and cutting tools to the machine. All of them are divided into two main groups: general-purpose devices and special-purpose devices.

The main feature of general-purpose devices is broad versatility; they are designed for use in handling different parts. This allows you to release significant series. This group of devices includes, for example, cartridges, centers, driving devices, lunettes, tool holders, dividing heads, etc.

The main feature of a special device is its suitability for only one operation of a certain process. The manufacturing requirement is measured in units and therefore the fixture is designed in the tool shop of the plant.

a) Design features.

- the first and main feature of designing a special device is to take into account specific production conditions (accuracy of operation, program of parts release).

- the second feature is the relatively short time spent on design.

-the third feature is that the design of drawings is based on wide use in the process of manufacturing assemblies (joint processing of parts, post-assembly processing, etc.)

b) requirements for devices.

Each requirement for the device must be fulfilled by the simplest means.

1. The design must meet its purpose - to ensure the highest productivity.

2. The design shall ensure the specified accuracy of the part in the operation.

3. The design shall be easy to use. This broad requirement covers a number of narrower ones;

A) safety in operation;

B) ease of installation and removal of the part;

C) easy cleaning from chips;

D) absence of detachable parts that can be lost.

The devices mainly distinguish three main varieties, similar in terms of application.

1. Lathe devices - for lathe, turret, round grinding machines, etc. General in use:

a) Connect the part to the spindle of the machine;

b) rotate during part machining (main motion).

2. Milling tools - for milling machines, boring machines, flat grinding machines, etc. Common in their application:

a) associate the part with the machine table;

b) move at low speed or are not movable.

3. Accessories - conductors - for drilling machines. General application:

a) linking the part to the machine table;

b) are equipped with conductor bushings .

1 General information about the fixture

1.1 Purpose and principle of operation

Conductor is used for drilling of hole f20 in "Fork" part and consists of one assembly unit, 12 parts and 26 standard items.

On the conductor plate, five bolts pos.16 and two pins pos.39 attach the rack pos.1. Conductor plate pos.6 is installed on post, where conductor bushing pos.24 is fixed with screw pos.21. It serves to guide the tool and in addition to that the tool does not take away an additional conductor bushing is installed pos.23.

The workpiece is based on f24, on the bottom plane and on the radius R10. It is installed on support pos.4, floating prism pos.3, rests against prism pos.7 and is clamped by grip pos.8. When the nut (29) is turned, the grip is lowered on the machined part and the part is clamped. After the nut is drilled by reverse rotation, the grip is lifted and the part is removed by turning it to the pin of thrust pos.41. To keep the floating prism of position 3 in the lower position, a latch of position 11 is provided, which rotates on the axis of position 10. To attach the conductor to the machine table, there are three slots on the plate.

1.2 Conductor disassembly sequence

The conductor in question is easily disassembled in detail

if repair or write-off is required. To do this, remove the post (1) sequentially, remove two bolts (15) and two pins (39) from the conductor plate (6). Before that remove the screw (21) that attaches the conductor bushing (24) and the adapter bushing (25).

To remove the rack itself, remove two screws pos.16 and two pins pos.39 .

The prefabricated clamp is disassembled in detail by removing the screw pos.29, washers pos.35.36, grip pos.8, washer pos.34, spring pos. 32, nut pos.28 and stud itself pos.38. Separately disconnect the grip from nut pos.27 and support pos.30.

The floating position 3 prism and the spring pos.31 are freely removed.

The support pos.4 and thrust pos.7 prism are removed due to removal of screws pos.19,20 and pins pos.40. The cover pos.2.

The remaining individual small parts of the conductor such as, stop pins pos.41, axis pos.9, bushing pos.10, latch pos.11 are removed separately

To facilitate the disassembly process, you can start from the base of the conductor when the bolts, screws, pins are removed and as a whole is released from the parts, and then only the "assembly units" are disassembled in detail.

2.2 Material Selection of Parts

The assembly unit of the rack pos.1 has a welded structure. Therefore, parts included in the assembly unit are made of steel 20 according to GOST 105088. High-quality carbon steel 20 is not expensive and has good weldability properties. Used without heat treatment.

Parts pos.3,4,7 are made of steel of 40X grade GOST 454371. Steel 40X alloyed, structural. It is used where increased strength is required. Steel hardens well.

Parts pos.2,6,8,5,10,11,12 are made of steel 45 GOST 105088. These parts require increased strength and the steels 45 are well hardened.

Bushings, pos.23; 24; 25 is made of carbon, tool steel, where high hardness wear resistance and heat resistance are required.

Spring pos.31; 32 are made of 65G steel, where strength, elasticity, endurance, high resistance to small plastic deformations in conditions of long-term loading are needed .

Fasteners screws, bolts, nuts, washers, hairpins, make of steel 45, 40H with a hardness of HRCe of 32.38.

3 Surface classification

3.1 Peculiarities of parts connection

When assembling, the main work type is to perform various part connections. Two or more parts (or assemblies) can be assembled in the form of a fixed or movable joint.

In case of fixed connection, assembled parts or assembly units maintain unchanged mutual position.

With movable connection, mating parts have the possibility of certain mutual movement.

In addition, the connections can be non-detachable (non-detachable) or disassembled (detachable). Non-detachable connections are used in cases when disassembly of connected parts is not provided during operation of the machine. If according to operating conditions it is necessary to disassemble the connections, they are performed disassembled.

Fixed joints can be non-detachable and disassembled. Fixed indiscriminate connections are carried out in various ways: welding (electric and gas); soldering (soft and hard solder); riveting; press fit; heating the female part and cooling the male part.

Riveting (in addition to the low-performance manual method) is carried out by pneumatic and electric hammers, electromechanical, pneumatic and pneumohydraulic presses, riveting machines (Fig. 280). The latter are the most productive, moreover, during their operation there are no adverse effects that are created during other riveting methods (noise, stress, fatigue of workers, etc.).

Press fit may be performed by pressing or pressing the part. When pressed, the male part (shaft) under pressure of the press is inserted into the hole of the female part (bushing, pulley, gear wheel). When pressing, on the contrary, the female part (bushing) is fitted with its hole on the male part (shaft).

The method of fitting by heating the female part is used mainly for bushings of large diameters with a small length. In this method of connection, the female part (bushing, etc.), in a heated state, is freely put on the male part (shaft) and, when cooled, is compressed, firmly tightly connected to the latter, forming a press fit.

Large parts are heated by electric current by resistance or induction method.

If according to production conditions (dimensions, part configuration, etc.) the heating of the female part is unacceptable or difficult, then the connection can be made by cooling the male part (shaft). In this method, the male part (shaft) is cooled to the required low temperature. When cooling, the male part is compressed, its dimensions decrease, and it freely enters the hole of the paired part (bushing) with which it mates. When the temperature of the cooled part rises to ambient temperature, the coupled parts will be firmly connected.

At a normal shop temperature of 18-20 ° C and cooling the part to - 100 ° C, a shrinkage of 0.01-0.02 mm for every 100 mm can be obtained, which is enough to obtain the required tension.

Fixed detachable connections are made by connecting mating parts with fits: blind, tight, tense, tight, threaded fasteners (bolts, screws, studs), by fitting on a cone.

Threaded fasteners, that is, connections by means of threaded articles, are mainly used when mating flat surfaces. To obtain the density of the compound, gaskets (made of leather, rubber, soft metals) are used.

Taper fit is used for tight joints undergoing frequent and rapid disassembly.

Mobile connections are disassembled (non-detachable mobile connections are rare). Movable connections are made during movable landings: sliding, movement, running, light-running, etc., as well as when connecting ball, conical and screw surfaces.

In this design of the proposed conductor, there is a non-detachable connection of pos.1 strut, since a welded connection is used.

Fixed disassembling connections are made by fastening connections such as screws, bolts, pins, nuts.

The fit in the conductor between the mating parts is mainly transient and with a gap, since during operation there is wear of the parts and their replacement with new ones.