Gantry Frame Large Size Structure Member Submerged Arc Welding Machine

A. Background on LHG Gantry Frame Long Straight Longitudinal Seam Welding Machine:

1. Function of LHG Lamp Post Large Gantry BOX Submerged Arc Welding Equipment:

1) Task: This is a Special Purpose Welding Machine, for performing long and straight longitudinal submerged arc welding, on large size structure members, such as municipal use lamp post;

2) Welding Technology: In the welding procedure of lamp post, after longitudinal seam back welding, it is necessary to have finished cover welding in the form of SAW (Submerged arc welding), which has the good points of deep penetration, large melt width and good welding forming;

3) Workpieces: This LHG machine has wide adaptability, besides lamp post, it can also be used on all kinds of long and large diameter structure members;

2. Specifications of Applicable Workpiece in SAW Longitudinal Seam Large Pipe Welding Machine:

Typical lamp post for LHG machine: (Fig.1)

B. Structure of LHG Lamp Post SAW Longitudinal Seam Gantry Welding Machine:

Judging from its appearance, this large machine incorporates moving gantry box frame and Welding Turning Roll into an integral structure:

Design print of Wuxi JACK LHG model machine: (Fig.2)

1. Gantry Frame of Longitudinal Seam Submerged Arc Welding Equipment:

1) The large box gantry structure forms trunk of machine. It is assembled into shape from welding structure members. Fabrication of the box gantry has superior welding quality, making sure sufficient strength and rigidity, to hold up the entire set of mechanism, for carrying out long straight longitudinal submerged arc welding on large workpieces;

2) Movement of gantry frame along rails is double drive, driven under Y series motor reducer, and transmitted by means of high precision rack, making smooth and stable running of the entire machine;

2. Internal Elevating Platform of Gantry Frame Longitudinal Seam Welding Machine:

1)  The platform installed inside the box gantry frame is the executing unit on welding. Its elevation is for accommodating on various diameter of pipes:

Vertical view on motor drive elevating platform: (Fig.3)

As can be seen from the above sketch, welding system are put onto this platform, including:

a) SAW power supply;

b) SAW welding flux recycling unit and flux hopper;

c) SAW welding wire spool;

3. Workpiece Support Roller Bed in Gantry Frame Longitudinal Seam Large Pipe Welding Machine:

1) This unit is for holding on large size workpiece, like lamp post;

2) There are two sets of welding roller bed, located beneath the elevating platform, one is driving mode, and the other is idle. Considering long length of the workpiece, distance between the 2 sets of roller bed is adjustable:

Welding roller bed beneath the box frame: (Fig.4)

C. Main Units of LHG Gantry SAW Longitudinal Seam Large Pipe Welding Machine:

1.  LHG SAW Longitudinal Seam Special Purpose Welding Machine:

Has main units of:

1) Motor drive moving large BOX gantry frame, along rails;

2) Internal motorized elevating platform and horizontal beam;

3) Welding Roller Bed type workpiece supporting unit;

4) Welding system, including SAW power supply, SAW wire feeder, SAW flux recycling unit;

5) Drive and transmission system, guiding system;

6) Electric control system;

2. Welding Torch Adjustment Unit in SAW Gantry Long Straight Longitudinal Seam Welding Machine:

Structure of welding torch mechanism: (Fig.5)

1) Requirement: Considering this special purpose Welding Equipment can not only be used for welding electric light pole, but also other long and large workpieces, such as BOX Beam/ Girder. So, the welding torch should be capable of movement in extensive range;

2) For this reason, the front beam of the elevating platform is finely machined, and fit with precise linear ball bearing, for precisely guiding transverse long distance movement of the welding torch and its carriage:

Welding torch and its mounting beam, guiding precise linear rail: (Fig.6)

3. Welding Torch Carriage Movement in SAW Longitudinal Seam Gantry Welding Machine:

1) Drive: Movement of welding torch carriage is driven with motor reducer and transmitted with gear rack couple;

2) Precise Control: During operation, to make sure welding torch precise and accurate tracking on welding seam, there is a set of manual cross slide inching adjustment unit, making sure welding torch tip right above welding seam all the while;

3) SAW welding flux barrel and hopper are installed right above the welding carriage, and moves along together with the carriage, during welding operation. In this way, the welding flux hopper is always located directly above welding torch where ever it goes, making fluent conveying of flux without interruption;

4. Intermediate Elevation Platform in LHG Gantry Frame Longitudinal Seam Submerged Arc Welding Equipment:

1) Role: This is the working table and central unit of the machine. Considering large size of the box gantry frame, fully guaranteeing steady and stable elevation of platform is very important during its running;

2) Structure: For this purpose, there is one set of motor reducer at the middle of the platform, with a piece of shaft delivering transmission to its both sides;

3) Drive and Transmission: There are two sets of motor reducer (One set at each side) at both sides of the platform. To cater for different diameters of lamp post/ pipes, the platform can be moved up and down smoothly in constant speed, which is transmitted by means of leadscrew and nut couple:

Front view on motor drive elevating platform: (Fig.7)

4) Precise Guide on Platform Elevation: In this gantry frame large pipe SAW Longitudinal Seam Welding Machine, platform elevation is guided with precise machining guideway. The guideways are welded onto the four columns of the box gantry frame. Besides, guiding rollers of the guiderail has eccentric shaft, making sure inching adjustment on pressing condition of the guiding rollers;

Below sketch gives assembly way of the guideway and its guiding roller for the elevating platform: (Fig.8)

5. Workpiece Support in LHG Large Pipe SAW Longitudinal Seam Gantry Welding Machine:

Arrangement of lamp post with table and roller beds: (Fig.9)

1) Type: Seen from the above sketch, the long and large workpiece is supported with two sets of Roller Bed. Of which, the larger side is driving type, the smaller side is idle type, with adjusting leadscrew;

2) Way of Installation: To make sure perfect horizontal position of finished welding seam on lamp post, the drive section roller bed should be embedded inside a pit in workshop floor; The smaller side idle roller bed should be equipped with lifting function;

3) To fully guarantee horizontal levelness of finished welding seam, besides the adjustable span between the two rollers at idle side, a supporting rack should be used at its beneath;

6.  Safety Assurance Unit: At lateral side of the box gantry frame, there is a staircase surrounded with guardrail. Operator can climb onto the elevating platform in safe condition;

D. Operation of LHG Gantry Frame Longitudinal Seam Submerged Arc Welding Equipment:

1. Major Steps in Gantry Frame Large Pipe Welding Machine:

1) To start work, first drive BOX gantry to one end of the rails;

2) Hoist the workpiece onto its roller bed supporting units;

3) Revolve roller beds, making welding seam on workpiece right at the position of 12:00, for carrying out straight longitudinal welding;

4) Adjust position of welding torch, deploy welding flux, and start on SAW power supply, initiating official running;

2. Welding System in LHG Gantry Frame Longitudinal Seam Special Purpose Welding Machine:

The long straight longitudinal SAW calls for high standard and consistent welding operation:

1) Grounding cable is joint with workpiece from SAW power supply directly;

2) Reliable connection of welding circuit, together with stable current and voltage produces uniform high quality welding seams;

3) Control console of SAW welding power supply is installed on the front beam of elevating platform, for easy access and convenient operation.

E. Technical Parameters of LHG Gantry Frame Lamp Post SAW Longitudinal Seam Special Purpose Welding Machine: