High Precision Flexible Welding Fixture And Special Welding Machine

A. Application of Welding Fixture and Various Special Welding Machine:

1. Functions: Welding equipment are widely used in wide variety of manufacturing sectors. These welding tools mainly involve 2 functions:

1) Welding Fixture: Fix firmly workpieces of different structures and dimensions during welding, especially irregular structure members;

2) Welding Machine: Perform different welding technology, especially niche technique, such as strap cladding, on different workpieces, especially special workpieces, such as mini-tubes;

2. Common Points on Technical Features:

1) Usually with value chain of engineering to order: Specifically designed based on customer demand;

2) Usually tailor made, which involves numerous deep communication between developers and users, to get ideal effect.

B. Roller Hard Surfacing Machine:

The machine on roller Built-up welding at Wuxi JACK workshop: (Fig.1)

1. Usage of Roller Strap Cladding Machine:

1) Background: Rollers of rolling mill usually exhibit issue of abrasion and worn after certain period of use. To make it gaining original hardness and strength, built-up welding, or hard surfacing is necessary;

2) Function: The machine is developed for this purpose: For built-up welding, or hard surfacing, on cylindrical body;

3) Welding Technique: Either SAW (Submerged arc welding) surfacing, or gas shielded surfacing;

4) Other Workpieces: With its welding head replaced, this welding equipment can also be applied in longitudinal and or circumferential welding of revolving parts;

2. Technical View on Roller Built-up Welding Machine:

1) Roller Fixture: During work, workpiece is clamped with a three claw chuck, with its rotating speed stepless adjustable controlled with A.C. inverter --- This rotating speed is also welding speed;

2) Hard Surfacing: Meanwhile, together with workpiece revolve, welding head moves in constant speed, which is set in the form of uniform pitch, and accomplishes hard surfacing job on the surface of the revolving workpiece;

3) Other Operations Available: To acquire additional functions beside built-up welding, this machine can also be equipped with supporting function units, such as electric arc swing, milling unit, etc.;

4) Different Diameters: To accommodate on changeable diameter of workpiece, welding head can be moved up and down with motor drive, together with anti-collision protection ability;

5) Electric control system has the core elements of PLC and inverter, realizing the function of preset and displaying of speed, rpm and displacement, catering for demand on various welding technique, making high automation working process of this Roller Hard Surfacing Machine;

6) Swing amplitude and frequency of welding head in the process of built-up welding is managed with special mechanism and controlled with PLC;

7) Welding wire feeder is also controlled with PLC, together with its protection function of ceasing operation, in case of electric arc breaking;

8) Duty cycle of welding system is 100%, meeting the demand of long time large current built-up welding.

3. Structure of Roller Strap Cladding Machine:

1) Main Units: Mechanical frame, welding system, and electric control system;

2) Mechanical frame: An integral entity, including workpiece holding bed, door or gantry, head stock and tail stock;

3) Stationary gantry serves as hanging support and movement guide of welding head;

4) Head stock is fixed type, integrated with electric control board, as well as the three claw chuck of workpiece;

5) Tail stock can move along machine bed, suitable for varying length of workpiece. Its transverse movement is transmitted with leadscrew, and guided with sliding bush;

6) Welding System of Roller Hard Surfacing Machine:

a)  Includes: Hard surfacing power supply, control console, welding head and its welding wire feeder;

b)  The control console, welding head and its welding wire feeder are integrated into an integral unit of moving carriage, moving along guiderail of gantry frame, in the process of built-up welding;

7) Electric control system has its control board fit at its head stock for easy access, with a remote panel for operating process;

8) This machine is custom made, of which parameters vary on specific size of workpiece and corresponding hard surfacing demand.

C. High Precision Small Pipe Welding Positioner:

1.  Usage of Small Pipe Welding Positioner:

1) This Wuxi JACK small welding equipment with high precision: (Fig.2)

2) Background: This is a custom made small Welding Machine. It is produced for a welding laboratory in a Chinese University, renowned for their welding major and department;

3) Function and Workpiece: For fulfilling small tube high precision welding, with small tubes in diameter scope of Φ10~ Φ100mm, thickness below 1mm;

2. Technical Features and Parameters of Small Pipe Welding Positioner:

1) Welding Modes: Plasma welding, vacuum electron beam welding, which deliver welding effect of high precision;

2) Workpiece revolve features in stable and very extensive speed range:

To be specific,

a) For Φ6mm diameter mini tube, its rotary linear speed is 0.834 ~1.668mm/sec., or 50 ~100mm/min., or revolution speed of 2.65 ~ 5.3rpm;

b) For Φ150mm diameter small tube, its min. rotary linear speed is 0.95mm/sec., or 57mm/min., or revolution speed of 0.12rpm;

c) Summing up, the revolution speed range for small pipe high precision welding has specification of 0.12 ~ 6 rpm;

3. Structure and Operation of Small Pipe Welding Positioner:

1) Drive: To acquire high precision welding on small pipes, servo motor is introduced, delivering wide speed range under constant output torque;

2) Welding Fixture: Small tube is fixed into a three claw chuck fixture: (Fig.3)

3) Motion: The entire welding unit integrating servo motor, chuck and workpiece can be moved along equipment bed, with manual turning by means of handwheel, and transmitted through leadscrew;

4) Guideway for leading this manual movement is of high precision type: (Fig.4)

5) Compact Dimension: Considering small size of tubes, this Small Pipe Welding Positioner has compact size, and is portable for easy relocation;

6) The delicate and fine production of this special made welding equipment, makes sure required high precision welding on small pipes.

D.  Various Special Design Welding Fixture:

Wuxi JACK welding fixing unit: (Fig.5)

1. Function: In essence, welding fixture is requisite assistant unit, supporting on workpiece fix. Its application makes welding operation convenient and user friendly;

2. Characteristic: It is usually special design, differed from case to case;

3. Benefits from Welding Fixture:

1) In Welding Machine, workpieces can be positioned and secured into ideal position for welding,

2) Delivering the highest degree of welding quality;

3) Having operator working in most comfortable ergonomics condition, in the case of manual welding;

4) Welding on irregular seam in irregular shape workpiece, maintain on tightly securing workpiece;

4. Applicating Scenarios Typical for Welding Fixture:

1) Piece welding of two or more workpieces, which calls for precise control and management on position;

2) Inspection on welding and or assembled finished workpiece, especially for those with certain difficult access without changing orientation, need to firmly clamp workpiece;

3) Besides welding, can also be used in assembly / painting/ testing steps;

5. The industries see frequent application of welding fixture include: Vehicle, Construction Machinery, Steel Structure, Rail Transportation, Bicycle, Motorcycle, Pressure Vessel, Frame and Tank, Robot Welding, Metal Furniture, Equipment Assembly, Sheet Metal Processing, Industrial Pipeline, etc.;

6. Technical Features of Welding Fixture:

1) The most salient characteristic is its tailor made in all application cases. In other words, every batch of such weld fixing unit is designed and produced, dedicate for current use only. No two sets of welding fixture from different working site are identical with each other;

2)  Positioning Precision of Welding Fixture:

Differs with specific application situation:

a) Some weld member fixing unit just for fixing the workpiece into place, such as for welding structure members;

b) Some welding fixtures poses positioning accuracy of tolerance ±1mm for its use, such as for welding cabs (Operating station) in Construction Machinery.

c) In the later type, series of advanced technology need to be utilized in the process of welding fixture development, such as the 3D design and validation, CMM measurement (Coordinate Measuring Machine), etc.;

3) Use of welding fixture is usually by hand: It tightens workpiece with quick clamps: (Fig.6)

4) Regular Check: As a sophisticated mechanism, especially those with high tolerance of positioning precision, welding fixture need to be maintained carefully in its daily use, being validated for its precision periodically (Half a year or every quarterly), by professional organization.