Accessory for segment keys cutting

Contents

Contents:

1.2. Purpose and design of the product

1.3. Manufacturing Type and Assembly Organizational Form

1.4. Drawing and Specification Analysis

1.5. Analysis of workability of the article design

1.6 Selection of methods to ensure assembly accuracy

1.7. Establishing the procedure for picking the product and compiling the process diagram of assembly

1.8. Analyzing Layout Variants of an Assembly

1.9. Development of process route of assembly

1.10. Purpose of process bases

1.11. Equipment selection

1.12. Determination of operating modes of assembly equipment

1.13. Checking the quality of the joint assembly

1.14. Normalization of assembly works time

1.15. Design Assembly Operations

1.16. Development of diagrams and selection of equipment for monitoring

1.17. Processing of process documentation

2.1. Source Data

2.2. Define Production Type

2.3. Purpose and design of the product

2.4. Drawing and Specification Analysis

2.5. Analysis of existing process plan

2.6. Procurement Selection

2.7. Purpose of process bases

2.8. Select how to treat individual surfaces

2.9. Process Route Development

2.10. Equipment selection

2.11. Selecting a Cutting Tool and Auxiliary Tool

2.12. Selection of fixtures

2.13. Calculation and selection of allowances

2.14 Mechanical Operations Design

2.15. Calculation of cutting modes

2.16. Checking Operation for Processing Accuracy

2.17. Functional Surface Quality Check

Introduction

1. Purpose and design of the product

device for cutting segment keys is intended for production of segment keys from blanks (finished washers) on horizontal milling machine. Housing (1) is the basic part, by means of which the accessory is installed on the machine table and fixed by means of bolted connections. Using centering keys, the assembly unit is centered on the machine table.

In the housing (1), with the help of screws (15), there is a mounting (3) installed, which serves to rest the blank against the end of the block. Grip 2 connected by pin 8 with piston 5 of reverse cylinder is fitted in housing 1. Slot for centering and free working stroke of disk cutter is made in both tack (2) and device (3). Blank is installed on prism (9), which is attached to housing by screws (14) and pins (19). Clamping of several blanks installed on prism (9) is performed by tack under action of hydraulic pressure on piston. Spring (7) returns grip to initial position after pressure is released in cylinder. Disk cutter is centered along axis of prism (9) and slot of installation (3) by means of probe. Cover (4) is installed in housing (1) by bolts (10) to seal oil in the housing. Ring (18) is installed in piston (5) as sealing ring. Also, rings (17) are installed as seals between piston and cover.

Housing (1), cover (4) are made of material SCH 1532 GOST 141254; grip (2), mounts (3), piston (5), washer (6), stud (8), prism (9) are made of steel 20 GOST 105060; spring (7) is made of 65G steel GOST 105060.

Overall dimensions of product 212kh80kh101mm.

Weight of the accessory is 7.22 kg (calculated in COMPAS3D).

The main bases of the device are:

Housing surface by means of which the assembly unit is installed on the machine table (housing base)

- Surfaces of slots for centering keys.

The assembly drawing shows sets of auxiliary bases, namely:

Prismatic Surface Intersection Line and Grip End

End of gripping and Axis of installation slot

The disc cutter is positioned by means of an installation slot, and the depth of milling is controlled by the probe.

Processing of process documentation

After the calculation and explanatory note is complete and the graphic part consisting of the assembly process diagram and the assembly process flow diagram is executed, it is necessary to fill in the operation map and sketch map for operations.

Requirements for construction and filling-in of operating cards are given in Table 2 of GOST 3.1407-86. For documents designed for other assembly methods, including main and related processes and operations, the need to specify the appropriate modes, their composition and design is established by the document developer.

Recording of operations and transitions in documents should be performed as per GOST 3.170379 - for locksmith and assembly works.

After all components and auxiliary materials have been specified, we proceed to the description of the operations themselves.

Source Data

The following are used as input data for process design of Prism part manufacturing:

Drawing of "Prism" detail (Appendix No. 2);

The production program is 15,000 pieces per year;

Background materials;

Materials of design technology practice;

Define Production Type

Task: You want to define the manufacturing type for the Prism part with an annual production program of N = 15000 pieces.

Based on item 1.3, the production type for the assembly of the article "Device for cutting segment keys" is medium-sized. Since the Prism part in the assembly unit is one, you can not perform additional calculations, conclude that the type of production of the part will also be medium-sized.

Drawing and Specification Analysis

Task: You want to analyze the part drawing and its process requirements.

The Prism part drawing has a sufficient number of views and sections that fully define the shape of the part with the required dimensions with their limit deviations. Surface feature and location deviations are implicit and correspond to the service purpose of the part.

Make sure that the dimensions are sufficient and correct:

- check the correctness of the tolerance of perpendicular to the main plane of the prism and mounting holes for pins, since it is not explicitly indicated, then the tolerance should be within the range of 14 qualitas of accuracy and not more than 0.2. In accordance with GOST 2464381, 0.2 mm is assigned to the size of 16 mm, therefore, the tolerance meets the requirements given to the part.

- check accuracy of ∅6+0,012 size. An interference shaft is installed in this hole. In accordance with the reference book [Sofkov], select the landing with interference H7/p6. In accordance with the manual [Soft] deviation H7 has a tolerance of + 0.012, therefore, the tolerance is assigned correctly.

- check roughness of setting planes Ra 0.32; in accordance with GOST 1219666, the mounting surfaces of the stationary prism have a roughness of 0.40, which corresponds to the assigned one in the drawing.

- check roughness of installation surface of prism Ra 0.32; in accordance with GOST 1219666, the installation surface of the prism has a roughness of 0.40, which corresponds to the assigned one in the drawing.

Unspecified dimensional limit deviations correspond to OST 1.7625378, which is similar to the deviations taken by the ECU of the CMEA for the 14th accuracy quota.

Select how to treat individual surfaces

Task: According to the drawing and technical requirements for the manufacture of the part, and based on the analysis performed in item 2.5, it is necessary to assign methods of treatment of all surfaces.

For the main functional surfaces, namely inclined planes (2), the following requirements are established: accuracy quota 7 and surface quality not higher than Ra 0.4 μm. These requirements can be met with the following machining sequence []:

- rough milling Ra 2512.5mkm, quota 1412;

- finishing milling Ra 12.56.3 μm, quota 1311;

- grinding rough Ra 6.30.4 mcm, quota 9-8;

- grinding pure Ra 3.20.2 mcm, quota 7-6;

- fine grinding Ra 1.60.1 mcm, quota 6;

This machining order allows you to achieve the required dimension accuracy and surface quality.

Similarly to this operation, we assign machining methods to other surfaces.

Process Route Development

Task: To develop a technological route for processing the Prism part in medium-scale production conditions.

Based on the analysis of the basic technological process, the processing is carried out in the following sequence: initially, the workpiece is milled on the surface (5) and drilled, the holes (3) are grilled and flowed, then the surfaces (6, 7, 8, 9, 10) are milled. Then, slot (1) and inclined surfaces of prism (2) are processed. Drill holes (4, 3) Then there is a control operation, and then the part is subjected to heat treatment - cementation with subsequent hardening, then the holes are ground and the surfaces of the prism (2, 6) are ground.

The route includes the following operations: operation 05 - milling drill (machining scheme - single, multi-tool); 10 - milling (machining scheme - single-seat, multi-tool); operation 15 - drill (processing scheme - single, multi-tool), operation 20 - control; step 25 - quenching; step 30 - grinding; step 35 - grinding (machining scheme - single-seat, multi-tool). This is followed by washing, control and other auxiliary operations.

Selecting a Cutting Tool and Auxiliary Tool

Task: Based on the basic process, it is necessary to check and assign a cutting and auxiliary tool for the machining operations proposed in item 2.5.

In new technological process for grinding operation we use the following tools: Circle grinding software 250х32х76 25A 25 CM12 of GOST 242483;

magnetic table ZD711AF is used to secure parts;

for the test the accessory for the test is used (refer to Appendix), Angle meter UM127 GOST 537888.

Similarly, we select a tool for other operations

Selection of fixtures

Task: In accordance with paragraph 2.5., a machine tool must be selected to equip operation 10.

This operation performs rough and finish milling of prism surfaces. A machine tool should be assigned to treat the sloping surfaces of the prism because the machining occurs at an angle to the base surface.

As initial data for selection of fixture we have:

- vertical cantilever cutting machine 6M12P

- Basing occurs on machined surfaces

- Largest size of clamped blank 85x54x130mm

We select the accessory for basing on the plane and two holes, which corresponds to GOST 31.0151.0190.

Mechanical Operations Design

Task: According to the selected surface treatment methods assigned by the process bases and the new version of the process route, it is necessary to develop the structure and composition of the process operations.

At step 10, the mounting plane of the prism, the inclined (working) prism surfaces, and the non-working prism surfaces are milled. Complete processing is carried out from one installation, with sequential treatment of each surface with the corresponding tool. For medium-scale production conditions, a Wide-universal milling machine with a 6DM80Sh rotary head is effective, using an end cutter with a cylindrical shank 22200042 GOST17025-71 as a cutting tool. As well as a special device for installation and basing. The use of this machine, tool and cutting tool allows to achieve the specified accuracy. Processing can be performed in 8 process transitions.

Initially, the blank is installed in the accessory and fixed with grips to the stepped hole Ø16mm. At the transition 1 the mill, we rough the prism ends with the dimensions 84 + 0.52 and 85 + 0.52. At the transition, the 2 performs rough and finishing treatment of the upper end of the prism, maintaining the size 30,+,0,092. At junction 3 we perform rough and finishing treatment of the slot, maintaining dimensions 100.06 and 240.19. At the transition 4, rough and finishing of the inclined surfaces of the prism is carried out, withstanding dimensions of 90° ± 05 '40 ± 0,0125. After machining, detach, remove, and perform proper inspection. In accordance with GOST 3.10279, we choose the name of the machining - milling. We form the structure of the transaction record and make it into operational cards (OK). We also develop an operational sketch with the designation of machined surfaces, technological bases, technological dimensions and the resulting roughness. Sketches are also included in Appendix 1 and in sketch maps

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