1. Workpiece Information

Rango de diámetro: 600 mm – 1400 mm

Longitud de pulido efectiva: ≤ 2500 mm

Peso de la pieza de trabajo: ≤ 1000 kg

Grinding requirement: Surface polishing of circumferential weld seams, cylinder body, and end caps via production line

Surface finish: ≤ Ra 0.8 μm (no spiral marks allowed)

Tiempo de ciclo: 10–13 minutes per piece (based on cylinder size for acceptance)

2. Grinding System Composition and Process Flow

System Configuration:

Cylinder Belt Grinding Machine ×1

Cylinder Brushing Machine ×1

CNC End Cap Polishing Machine ×1

Process Steps:

Loading Rack:

For placing LNG cylinders before grinding (single station)

Includes lifting roller conveyor

Manual positioning and weld seam preparation

Cylinder Belt Grinding:

Cylinder belt grinding machine

Equipped with 2 grinding heads + 1 traversing mechanism

Cylinder Brushing:

Cylinder brushing (drawing) machine

Equipped with 2 brushing heads + 1 traversing mechanism

Uses non-woven or wire drawing wheels

End Cap Polishing:

CNC polishing machine for end caps

Equipped with 2 rotary grinding heads + 2 traversing mechanisms

Unloading Rack:

For collecting finished cylinders (single station)

Polishing line dimensions (L × W × H): 17.5 m × 2.5 m × 3.6 m

Proceso de pulido:

1. Loading the Cylinder (Loading Rack):

The cylinder is placed on the loading rack, and the “roller mode”is selected. The lifting roller table rises and rotates the cylinder. At this stage, the operator manually grinds the circumferential weld seam

After completion, the workpiece transfer function is activated. The roller table lowers, and the cylinder is conveyed horizontally into the main polishing line.

2. Belt Grinding (Cylinder Belt Grinding Machine):

Once the conveying mechanism of the cylinder belt grinding machine receives the cylinder, it lowers the workpiece. The cylinder is then rotated by the roller support system, while two belt grinding heads simultaneously polish the cylinder surface.

After grinding, the conveying mechanism lifts the cylinder and transfers it to the next station.

3. Brushing/Finishing (Cylinder Brushing Machine):

The conveying mechanism receives and lowers the workpiece. The cylinder is again rotated by the roller support system, and two wide brushing heads (drawing wheels) polish the cylinder.

Once the brushing is complete, the conveying mechanism lifts the cylinder and transfers it to the next station.

4. End Cap Polishing (End Cap Polishing Machine):

The conveying mechanism receives and lowers the cylinder. It is rotated by the roller support system, while two sets of **three-axis polishing heads polish the front and rear end caps** of the cylinder simultaneously.

After polishing, the conveying mechanism lifts and transfers the finished cylinder to the unloading rack, completing the entire polishing process.

Note

All grinding heads move along the cylinder length, while the cylinder rotates horizontally along its axis.

The conveying rollers used throughout the process (including loading and unloading racks) adopt horizontal support conveying** for smooth transfer.

3. Introduction to the machines used for grinding

1、 Double-headed belt polishing machine

Double-headed belt polishing machine

1.1 Grinding action

According to the different sizes of workpieces, the PLC controls the automatic positioning of the grinding head. After the workpiece enters the polishing machine, the internal conveying device of the machine positions the workpiece, the roller motor starts flexibly, drives the workpiece to rotate, the grinding head floats open, and the grinding head starts grinding. The two grinding heads grind the barrel body at the same time. After grinding, the grinding head automatically lifts up and the grinding head motor turns off. The positioning stopper returns to its original position, and the “conveying mechanism” rises to transfer the workpiece to the next grinding process.

Note: Grinding and conveying are all automatically controlled by PLC

1.2  Machine structure

The machine covers an area of ​​approximately 3500*2500*3600 in length*width*height. The machine structure configuration is shown in the table below.

The hanging plate and small column mechanism are enhanced, using 1 set of walking mechanism + 2 sets of standard grinding heads (as shown in the figure)

The width of the sanding belt is 100mm, and the two sets of sanding belt grinding heads are installed with different sanding belts for simultaneous grinding.

1.3  Machine parts information

1.4  Grinding head introduction

Grinding head assembly (two sets)

This grinding head assembly can be used with different consumables such as abrasive belts, flap wheels, wire wheels, etc. There is a floating cylinder at the end to provide sufficient floating pressure during grinding. In addition, the hanging plate and small column can flexibly adjust the relative position of the grinding head and the workpiece under the control of the PLC system to adapt to the grinding of workpieces of different specifications.

1.5  Workpiece rotation, conveying, and hand-stop components

Workpiece bottom frame

1. Workpiece rotating driving wheel group, 2. Workpiece rotating driven wheel group, 3. Workpiece conveying assembly, 4. Workpiece hand stop

The center distance between the workpiece rotating driving and driven wheel groups is adjustable, servo controlled, and electrically adjusted to adapt to the grinding of workpieces of different diameters.

The position of the workpiece rotating driven wheel is adjusted by manual screw and placed at the circumferential weld to avoid wheel marks on the cylinder.

The conveying assembly is designed with pneumatic lifting, which rises during conveying and falls during workpiece grinding, and the conveying wheel group is designed with a torque limiting mechanism. When the workpiece reaches the specified position and is blocked by the hand stop assembly, the conveying wheel will slip and idle to prevent impact on the workpiece, thereby causing damage to the workpiece surface.

The hand stop assembly is equipped with a pneumatic lifting function, which rises during conveying and falls during grinding, and the relative contact position between the hand stop wheel and the workpiece is adjustable to avoid the elbow welded on the workpiece.

1.6. Control method

Single machine: Xinjie touch screen + Xinjie PLC servo multi-axis control, complete workpiece positioning, rotation, and grinding;

Online: The master control cabinet PLC host computer controls the feeding and unloading, single machine processing start and stop, and information collection;

Forced: The conveying mechanism is always lifted, the conveying wheel rotates, and it is forced to pass through the equipment.

2、Cylinder double-head wire drawing machine

The gantry, bottom frame, conveying mechanism, rolling table mechanism, grinding head body, control method, etc. are consistent with the [cylinder double-headed abrasive belt polishing machine]

The hanging plate and small column mechanism are enhanced, using 1 set of walking mechanism + wide wire drawing wheel double grinding head (as shown in the figure)Cylinder double-head wire drawing machine*1

2.1  machine structure

L*W*H:3500*2500*3600，

2.2  machine parts information

3、CNC tank head polishing machine

The width of the main frame and gantry is increased to 4500mm, and a set of three-axis grinding heads are used to polish the heads at the front and rear ends.

3.1  machine structure

3.2  machine parts information

 3.3  Tank head grinding head introduction

Head polishing grinding head assembly (two sets)

The main function of this grinding head assembly is the same as that of the cylinder grinding head. The difference is that this grinding head has an additional set of displacement mechanisms (an additional set of rotating axes on the servo control) to facilitate grinding the end head of the workpiece. The status of each grinding head during grinding is shown in the figure below.

3.4  control method

Stand-alone: 2 sets of domestic GUGE three-axis CNC systems (crossbeam up and down, crossbeam left and right, grinding head angle servo control), workpiece positioning, rotation, grinding;

Online: master control cabinet PLC host computer controls inlet and outlet conveying, stand-alone CNC head processing;

Forced: The conveying mechanism is always raised, the conveying wheel rotates, and forced to pass through the equipment.

4. Loading and unloading rack

4.1  loanding rack

Gas cylinder roller conveyor line + lifting roller mechanism
Length, width and height: 3000*600*700mm

1. Select “roller mode”, the lifting roller is lifted, driving the tank body to rotate (3 rpm), and the girth weld is manually polished;
2. Select “feed start”, the lifting roller falls, and the cylinder body is horizontally transported into the polishing line.

4.2  unloading rack

Standard gas cylinder roller conveyor line
L*W*H: 2200*600*700mm

5. 3 sets of host housing (enclosed housing with dust suction port）

Note: The housing is equipped with a dust suction port

6. List of main components