pneumatic circuits for industrial applications

PNEUMATIC CIRCUITS FOR INDUSTRIAL APPLICATIONS

PNEUMATIC CIRCUIT FOR PICK AND PLACE ROBOT GRIPPER ACTUATION 

(DESIGN OF PNEUMATIC ROBOT GRIPPER)

1. Functional and Operational Requirements

• Pneumatic robot gripper, as the name suggests, works with compressed air. The pneumatic grippers are used in robots for pick and place applications.

• The gripper is an end effector that uses mechanical fingers actuated by a pneumatic circuit to grasp an object. A typical two-jaw cam-operated rotary gripper is shown in Fig.16.8(a). In this, there is a cam and follower arrangement, often using a spring- loaded follower, which can provide the opening and closing of the gripper. The movement of cam in one direction would force the gripper to open, while the movement of the cam in opposite direction causes the spring to force the gripper to close.

2. Circuit

Fig.16.8 illustrates a simple pneumatic circuit for pick and place robot gripper actuation. This circuit employs a solenoid-operated spring-offset 5/2 DC valve, two flow control valves, and a two-jaw cam-operated gripper.

3. Operation

Extension: When the 5/2 DC valve is shifted to its left mode (i.e., the solenoid is energized), air flows to the blind end of the cylinder via the flow control valve FCV1. This air flow extends the cylinder and thus the actuating force (Fo) is applied on the cam of the gripper. The cam in turn actuates the gripper jaws so that grip the object.

Retraction: When the 5/2 DC valve is shifted to its right mode (i.e., the solenoid is de- energized), air flows to the rod end of the cylinder and hence the cylinder retracts, so that the gripper ungrips the object. The air from the blind end of the cylinder is exhausted to the atmosphere through the flow control valve FCV1.

It may be noted that the extending speed of the cylinder and the actuating force can be regulated by just regulating the air flow in the flow control valves.