Browse Prior Art Database

Two-step Anvil Valve Control for Matrix Drill Tool

IP.com Disclosure Number: IPCOM000120411D
Original Publication Date: 1991-Apr-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 2 page(s) / 66K

Publishing Venue

IBM

Related People

Acciai, M: AUTHOR [+4]

Abstract

Disclosed is a process to decrease the anvil cycle time on a matrix drill tool by decreasing the response time from the control signal to the actual time the anvil begins to move.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 60% of the total text.

Two-step Anvil Valve Control for Matrix Drill Tool

      Disclosed is a process to decrease the anvil cycle time
on a matrix drill tool by decreasing the response time from the
control signal to the actual time the anvil begins to move.

      When doing matrix drilling using an IBM Matrix Drill Tool, the
panel to be drilled is clamped in place by a hydraulic anvil.  The
hydraulic fluid is ported to the anvil cylinders by an
amplifier-driven hydraulic servo valve.  The amplifier receives a +
or - 10-volt input which is controlled by the up/down command signal
from the host controller.  The anvil is either in the up (clamped) or
down (unclamped) position.

      Anvil flight time was minimized through increased hydraulic
pressure and flow, but the majority of lost time was due to the
response of the anvil servo valve.  It was found that response from
full open in the up position to full open in the down position was
2.5 to 3 times longer than if the valve went from the zero (null)
position to the full open position.  The valve could not be put at
null, however, as the anvil would lose clamping force due to leakage.
It was discovered through experimentation that clamping force could
be maintained with only minor hydraulic flow once the anvil had
clamped.  To gain the required response time a two-step anvil circuit
was designed that would give an initial full open signal to the valve
to go closer to but not at the null position.  Anvil response time
(clamp t...