Recently, I was attracted by a "cockroach robot", which is said to be able to squeeze its body into a small space when scientists study cockroaches and still maintain movement.
According to this feature, scientists have made a device with an exoskeleton similar to a plate, which allows robots to manipulate objects very easily without extreme precision, currently including soft robots (Soft Robotics) and imperial robots Many companies, including Empire Robotics, have begun selling soft claws, which are expected to be used in earthquake search and rescue in the future. As a machinist, I remembered the soft claws used for machining.
The soft claw can fit the surface of the workpiece to the greatest extent, which can not only ensure the transmission of greater torque, but also avoid the workpiece from being pinched. These advantages are incomparable to the hard claw.
01
What should I pay attention to when making soft claws?
√Selection of soft claw material
"Soft" here means: good processing performance does not mean that it must be lower than the hardness of the workpiece. For mass production, the hardness of soft jaws will have a great impact on the stability of processing. Choosing soft jaw materials with a higher hardness than the workpiece will not only improve the service life of the soft jaws, but also have a positive effect on the stability of processing. Impact.
√The installation position of the soft jaw on the chuck
Any T-block exceeding the maximum diameter of the chuck is not allowed, which would be a great safety risk.
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√Pressure and position when using the claw trimmer
It is recommended that the pressure during use is close to the pressure during workpiece processing. The chuck is in the middle of the range of motion during processing, and the direction of the clamping force when repairing the jaws is consistent with the direction of the workpiece clamping force.
√Effect of chuck diameter and rotational speed on clamping force
Due to the effect of centrifugal force, when the chuck operates at high speed, the clamping force will be greatly reduced (please refer to the description on the chuck for details).
Special Note:
▪Make the inner hole the same size as the diameter of the workpiece to reduce the possibility of pinching the workpiece.
▪Add undercuts to ensure repeated positioning of workpieces.
▪Remove the burrs and sharp corners on the soft claws (be careful not to scratch your hands).
▪Selection of soft jaw size.
▪Soft jaws should hold at least 1/3 of the length of the workpiece.
02
Special workpieces need to know some special knowledge
When processing thin-walled or ring-shaped workpieces, overcoming the deformation of the workpiece is the first problem to be faced. The key is to choose the type of soft jaws and the appropriate chuck pressure.
Under the same chuck pressure, the fan-shaped soft jaw has a larger contact area than the standard soft jaw, which means that the pressure on the workpiece is more uniform, while the standard soft jaw will appear in the following situation: Improper selection of workpiece deformation.
The actual situation may not be as obvious as shown in the picture, but when other conditions are the same except for the different types of soft jaws, there are still cases where the degree of deformation of the workpiece varies by dozens of times.
03
Marking and claw repair should be kept in mind
Regardless of whether it is a fan-shaped soft jaw or a standard soft jaw, it will need to be rebuilt due to excessive wear of the soft jaw or the replacement of processed parts. There are many benefits to doing. Remember: it should be stamped, and the marker pen is used lazily in the picture, please don't learn.
Increases the number of uses of the soft claw; more detailed markings also reduce the likelihood of misuse.
Next is the choice of claw trimmers.
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Generally speaking, the claw trimmer on the left trims the inner claws, and the one on the right trims the outer claws
When the two kinds of claw trimmers cannot meet the conditions, we need to make a special claw trimming part, such as processing the lower ring to repair the outer claw.
When the part that needs to be clamped is relatively long, the workpiece and the soft jaws will not fit completely, which is commonly known as "bell mouth". The specific performance is that there is a gap between the top of the soft jaws and the workpiece.
The most effective solution is: process a taper on the soft jaw, measure the size of the gap with a feeler gauge, measure the length of the clamp, and then calculate the size of the taper.
