Required Components Access to the following components is needed to complete thi

Question

Required Components Access to the following components is needed to complete this activity: Hydraulic power unit System relief valve Manually operated, three-position, four-way directional control valve with open center. Sequence valve Double acting cylinder Hydraulic motor Pressure gauges Manifolds Hoses What determines the maximum force that can be generated by the cylinder without activating the motor? What causes the pressure readings on gauge 2 during extension of the cylinder? Why are the pressures during cylinder retraction generally higher than during cylinder extension? Do these differences have anything to do the operation of the basic sequence circuit? Why is cracking pressure used rather than full-flow pressure when setting up a sequence valve? Based on the test circuit, explain why sequence valves need to be externally drained. Design a sequence circuit for a system containing two cylinders. The sequence of cylinder movement should be: cylinder 1 extends cylinder 2 extends, cylinder 2 retracts, cylinder 1 retracts.

Explanation / Answer

Cylinders may be sequenced by restricting flow to one cylinder. One method of restricting flow is with backpressure check valves. They prevent flow until a set pressure is reached. In this circuit, cylinder 1 extends and retracts ahead of cylinder 2. Sequence valves Several cylinders can be connected to move in sequence on forward and return strokes. In this circuit, a clamp must close before a drill descends. On the return stroke, the drill must pull out of the work before the clamp opens. The sequence valves are arranged to cause pressure buildup when one cylinder completes its stroke, the valve opens to allow flow to the other cylinder. Electrical control Limit switches momentarily actuated by the cylinders control the solenoid valves to sequence this circuit. Solenoid a is energized by a pushbutton to initiate movement 1. At the completion of movement 1, limit switch E is actuated to energize solenoid c, initiating movement 2. At the end of movement 2, limit switch F is actuated to energize solenoid b, initiating movement 3. At the end of this movement, limit switch G is actuated to energize solenoid d, initiating movement 4. The sequence valves prevent a pressure drop in either cylinder while the other operates.

Related Questions

Navigate

• Browse (All)
• Browse R
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.