When the workpiece is welded and heat treated by a high-frequency resistance welding machine, many electric resistance welded pipe manufacturers use the hydraulic cylinder for the purpose of improving the welding speed and improving the production efficiency. Today, let’s take a look at the types of hydraulic cylinders.
There are two types of hydraulic cylinders according to the form of motion: linear motion and swing. In the welding tooling, the linear motion type is mainly used, and the output is the axial force. The common forms of hydraulic cylinders for linear motion are as follows:
(1) Piston type The single piston rod hydraulic cylinder has a piston rod at one end.
(2) plunger type:
1. The plunger type hydraulic cylinder is a single-acting hydraulic cylinder. It can only achieve movement in one direction by hydraulic pressure. The return stroke of the plunger depends on other external forces or the weight of the plunger.
2. The plunger is supported only by the cylinder liner and is not in contact with the cylinder liner. The cylinder sleeve is easy to process, so it is suitable for long-stroke hydraulic cylinders.
3. The plunger is always under pressure during operation, so it must have sufficient stiffness.
4. The weight of the plunger is often large. When placed horizontally, it is easy to sag due to its own weight, causing the seal and the guide to wear on one side, so it is more advantageous for vertical use. The piston can only move in one direction, and the movement in the opposite direction needs to be done by external force. However, the stroke is generally larger than that of a piston hydraulic cylinder.
(3) Telescopic Retractable hydraulic cylinders have two or more stages of pistons. The sequence of piston extension is from large to small, and the order of empty retraction is generally from small to large. The telescopic cylinder can achieve a long stroke, while the retraction length is shorter and the structure is more compact. Such hydraulic cylinders are commonly used in construction machinery and agricultural machinery. There are a plurality of pistons that move in sequence, and the output speed and output force of each piston change when moving successively.
The high-frequency welding machine heats the workpiece and, if assisted by robotic welding fixtures, will make your welding process simpler and more intelligent. Therefore, it is very necessary to understand the principles of robotic welding fixture design. When designing robotic welding fixtures, we should pay attention to the following principles:
1. Clamping is reliable and the rigidity is appropriate. When clamping, the positioning position and geometry of the welding are not damaged. After clamping, neither the looseness of the weldment nor the excessive restraint of the weldment is produced, and a large stress is generated. In addition to reliable positioning and clamping, the fixture should also be easy to assemble and unload.
2. When designing the robot welding fixture, the structural scheme of the fixture must be matched with the output of the product, and the welding process analysis should be performed on the product.
3. In order to facilitate the control, the structure of the positioner and the clamping mechanism should not be too much on the same fixture, and only one power source should be selected as much as possible.
4. The robot welding tooling generally adopts the double-station form, that is, the robot is equipped with two sets of independent tooling. When the robot is welding, the worker unloads and assembles the tooling behind the baffle. After welding, it is transferred to the welding, so that the assembly, unloading and welding of the workpiece can be cross-over, which can greatly improve the utilization rate of the robot.
5. The fixture should have sufficient assembly and welding space. All positioning components and clamping mechanisms should be kept at an appropriate distance from the weld bead.
6. When clamping thin parts, limit the clamping force, or take the indenter stroke limit, increase the contact area of the indenter, and add copper and aluminum bushings.