U.S. patent application number 09/863563 was filed with the patent office on 2002-01-31 for machine tool with servo drive mechanism.
This patent application is currently assigned to Davenport Industries, LLC.. Invention is credited to Muscarella, Patrick L., Patridge, Steven K..
Application Number | 20020010991 09/863563 |
Document ID | / |
Family ID | 24419788 |
Filed Date | 2002-01-31 |
United States Patent
Application |
20020010991 |
Kind Code |
A1 |
Muscarella, Patrick L. ; et
al. |
January 31, 2002 |
Machine tool with servo drive mechanism
Abstract
A machine tool has a cam shaft and indexing drive mechanism
which is driven by a servomotor and is therefore adapted for
operation within a wide range of operational parameters. An encoder
mechanism provides feedback to the servo drive mechanism to effect
operational control. The machine tool further comprises a variable
frequency drive motor which operates the spindles of the machine
tool independently of the cam shaft and indexing drive. A
servo-operated threading mechanism is operable at one or more
workstations of the machine tool to provide threading of parts
manufactured thereby. A computer control system controls and
monitors the entire operation of the machine tool.
Inventors: |
Muscarella, Patrick L.;
(Penfield, NY) ; Patridge, Steven K.; (Webster,
NY) |
Correspondence
Address: |
Michael A. O'Neil
Michael A. O'Neil, P.C.
Suite 1030
5949 Sherry Lane
Dallas
TX
75225
US
|
Assignee: |
Davenport Industries, LLC.
|
Family ID: |
24419788 |
Appl. No.: |
09/863563 |
Filed: |
May 23, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09863563 |
May 23, 2001 |
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09769189 |
Jan 25, 2001 |
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6263553 |
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09769189 |
Jan 25, 2001 |
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09604484 |
Jun 27, 2000 |
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6219895 |
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Current U.S.
Class: |
29/38B ; 29/38A;
82/118; 82/129 |
Current CPC
Class: |
B23Q 5/341 20130101;
Y02P 70/167 20151101; Y10T 82/2524 20150115; B23Q 5/36 20130101;
Y02P 70/10 20151101; B23Q 5/10 20130101; G05B 2219/50233 20130101;
Y10T 29/513 20150115; B23Q 15/013 20130101; B23Q 39/044 20130101;
Y10T 82/2502 20150115; Y10T 29/5128 20150115; B23Q 5/28 20130101;
Y10T 29/5129 20150115 |
Class at
Publication: |
29/38.00B ;
29/38.00A; 82/118; 82/129 |
International
Class: |
B23B 009/10; B23B
013/04; B23Q 007/02 |
Claims
What is claimed is:
1. In a machine tool of the type wherein lengths of bar stock are
rotated about longitudinal axes and machining tools are actuated by
cams to engage the machining tools with the rotating bar stock to
effect machining thereof, the improvement comprising: a plurality
of working spindles each for receiving a length of bar stock
therein and each defining an axis of rotation of its respective
length of bar stock; a variable frequency spindle drive motor; a
gear train operatively connecting the variable speed spindle drive
motor to the working spindles to effect rotation of the working
spindles and the lengths of bar stock carried thereby about the
axes of rotation defined by the working spindles; a first cam shaft
extending parallel to the axes of rotation defined by the working
spindles; a plurality of first cams mounted on the first cam shaft
for rotation thereby to cause operation of first machining tools
thereby machining the lengths of bar stock carried by the working
spindles during rotation thereof under the action of the variable
frequency spindle drive motor; an indexing mechanism driven by the
first cam shaft for sequentially indexing each of the working
spindles through a plurality of workstations; a second cam shaft
extending perpendicularly to the axes of rotation defined by the
working spindles; a plurality of second cams mounted on the second
cam shaft for rotation thereby to cause operation of second
machining apparatus thereby machining the lengths of bar stock
carried by the working spindles during rotation thereof under the
action of the variable frequency spindle drive motor; a servomotor;
a gear train operatively connecting the servomotor to the first and
second cam shafts to effect rotation of the first and second cams
and to effect operation of the indexing mechanism independently of
the operation of the variable frequency spindle drive motor; and a
programmable logic controller for controlling the operation of the
variable frequency spindle drive motor and the servomotor.
2. The improvement according to claim 1 further including an
absolute encoder driven by the first cam shaft under the action of
the servomotor for producing an output indicative of the operation
of the servomotor and for directing the output to the programmable
logic controller.
3. The improvement according to claim 2 further including a
threading mechanism for performing machining of the lengths of bar
stock and a servomotor for operating the threading mechanism under
control of the programmable logic controller.
Description
TECHNICAL FIELD
[0001] This invention relates generally to machine tools, and more
particularly to a machine tool having a servo drive mechanism for
the cam shafts and the indexing mechanism of the machine tool and a
variable frequency drive motor for the spindles of the machine
tool.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] The Davenport Model B screw machine is one of the world's
most popular machine tools. Although completed in 1927, the design
of the Model B has withstood the test of time and continues to
compete favorably with computer controlled machine tools introduced
much more recently. Perhaps this is because the Model B is
economical to purchase and use and highly reliable in
opera-ion.
[0003] The present invention comprises an improvement over the
Davenport Mode B. While preserving many features of the Model B,
the machine tool of the present invention differs therefrom by
providing a servo mechanism for operating the cam shafts and the
indexing mechanism of the machine tool. The machine tool of the
present invention further differentiates over the prior art by
providing a variable frequency drive motor for operating the
spindles of the machine tool. The machine tool of the present
invention further differentiates over the prior art by providing a
servo mechanism for performing threading operations. The machine
tool of the present invention further differs from the prior art in
that it is provided with a computer controlled system which
controls and monitors the entire operation of the machine tool.
[0004] In accordance with the broader aspects of the invention, a
machine tool is provided with a cam shaft and indexing drive
mechanism which is independent from the spindle drive mechanism.
The cam shaft and indexing drive mechanism is driven by a
servomotor and is therefore adapted for operation within a wide
range of operational drive mechanism to effect operational
control.
[0005] The machine tool of the present invention further comprises
a variable frequency drive motor which operates the spindles o the
machine tool. In this manger the rotational speed of the spindles
is precisely controlled.
[0006] The machine tool of the present invention further comprises
a servo-operated threading mechanism. The threading mechanism is
operable at one or more workstations of the machine tool to provide
threading or parts is manufactured thereby.
[0007] The machine tool of the present invention further comprises
a computer control system which controls and monitors the entire
operation of the machine tool. In particular, the computer control
system regulates the operation of the cam shaft and indexing servo
mechanism, controls the operation of the threading servo mechanism,
and controls the operation of the variable frequency spindle drive
motor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] A more complete understanding of the invention may be had by
reference to the following Detailed Description, when taken in
conjunction with the accompanying Drawings, wherein:
[0009] FIG. 1 is a top view of a machine tool incorporating the
present invention;
[0010] FIG. 2 is a side view of the machine tool of FIGURE FIG. 3
is a side view similar to FIG. 2 further illustrating certain
components of the machine tool;
[0011] FIG. 4 is an exploded perspective view illustrating the
spindle drive mechanism, the cam shaft and indexing servo drive
mechanism, and a bracket assembly which supports the spindle drive
mechanism and the cam shaft and indexing servo mechanism;
[0012] FIG. 5 is a perspective view illustrating the cam shaft and
indexing servo drive mechanism of the present invention;
[0013] FIG. 6 is a top view of the cam shaft and indexing servo
drive mechanism of the present invention;
[0014] FIG. 7 is a perspective view illustrating component parts of
the indexing system of the machine tool of the present
invention;
[0015] FIG. 8 is a perspective view illustrating the servo
threading mechanism of the present invention;
[0016] FIG. 9 is a perspective view illustrating the spindle drive
mechanism of the machine tool of the present invention;
[0017] FIG. 10 is a schematic illustration of the control system of
the machine tool of the present invention;
[0018] FIG. 11 is a front view of the control panel of the machine
tool of the present invention;
[0019] FIG. 12 is a side view of the control panel of FIG. 11;
[0020] FIG. 13 is a flowchart illustrating the several modes of
operation of the machine tool of the present invention;
[0021] FIG. 14 is a flowchart illustrating the automatic operation
sequence of the machine tool of the present invention;
[0022] FIG. 15 is a flowchart illustrating the dry-run operation
sequence of the machine tool of the present invention;
[0023] FIG. 16 is a flowchart illustrating the single step
operation sequence of the machine tool of the present
invention;
[0024] FIG. 17 is a flowchart illustrating the various operational
menus which are utilized to setup, control, and diagnose the
operation of the machine tool of the present invention;
[0025] FIG. 18 is flowchart illustrating the stock depletion
operation sequence of the machine tool of the present invention;
and
[0026] FIG. 19 is a flowchart illustrating the operation and
control of the servo threading mechanism of FIG. 8.
DETAILED DESCRIPTION
[0027] Referring now to the Drawings, and particularly to FIGS. 1
and 2 thereof, there is shown a machine tool 30 incorporating the
present invention. The machine tool 30 is of the type commonly
known as a screw machine and includes a base or frame 32 comprising
a pan 34 which serves as a coolant reservoir for the machine tool
30.
[0028] A lubricating fluid pump assembly 40 is situated at one end
of the machine tool 30. The lubricating fluid pump assembly 40
functions to direct lubricating fluid to all of the operating
components of the machine tool 30. A coolant pump assembly 42 is
located adjacent the lubricating fluid pump assembly 40. The
coolant pump assembly 42 functions to withdraw coolant from the pan
34 and to circulate coolant to all of the machining tools operated
by the machine tool 30.
[0029] The machine tool 30 includes a variable frequency spindle
drive motor 44 and a servo drive motor 46 which operates the cam
shafts and the indexing mechanism of the machine tool 30. As is
best shown in FIG. 34, the spindle drive motor 44 and the servo
drive motor 46 are supported on a bracket 48 which is in turn
supported by the base or frame 32 of the machine tool 30.
[0030] Referring to FIGS. 5 and 6, the servomotor 46 is operatively
connected to a gear box 56 which in turn drives a bevel gearset 58
through a coupling 60.
[0031] The bevel gearset 58 directs operating power from the
servomotor 46 to a drive shaft 66 and to a drive shaft 68 extending
perpendicularly to the drive shaft 66. The drive shaft 66 extends
to a rear worm 70 which drives a gear 72. The gear 72 causes
rotation of an end cam shaft 74 which in turn rotates a plurality
of tool spindle cams 76.
[0032] The drive shaft 68 drives a front worm 80 which drives a
gear 82. The gear 82 in turn drives a side cam shaft 84 to cause
rotation of a plurality of cross slide cars 86 and a locating cam
88. The drive shaft 84 also causes rotation of a chuck and feed cam
90 and an absolute encoder 92.
[0033] FIG. 7 illustrates the indexing mechanism of the machine
tool 30. In addition to rotating the drive shaft 84, the gear 82
which is driven by the worm 80 (not shown in FIG. 6) drives the
operating component of a Geneva mechanism 100. Thus, upon each
complete revolution of the gear 82, the Geneva mechanism 100 is
advanced one segment which, in the case of the machine tool 30,
comprises 1/5 of the complete revolution.
[0034] A gear 102 is secured to the driven component of the Geneva
mechanism 100 for rotation therewith. The gear 102 is mounted in
mesh with a gear 104 which is secured to the spindle mechanism 106
of the machine tool 30. The spindle mechanism 106 comprises five
spindles. Thus, the Geneva mechanism 100 functions to sequentially
advance each spindle of the spindle mechanism 106 from one
workstation to the next.
[0035] A lever 108 is actuated by the locating cam 88. The lever
108 has a jaw 110 at the distal end thereof. The locating Cam 88
functions to selectively engage the jaw 110 with a plurality of
teeth 112 projecting from the spindle mechanism 106. In this manner
locating cam 88 and the lever 108 function to engage the jaw 110
with the teeth 112 thereby precisely locating the spindle mechanism
106 at each workstation or the machine tool 30.
[0036] Referring to FIG. 1, 2, and 8, the machine tool 30 further
includes a servo thread cutting assembly 120. The servo thread
cutting assembly 120 includes a servomotor 122 which drives a gear
box 124. The function of the servomotor 122 and the gear box 124 is
to engage one or more thread cutting tools with one or more work
pieces at one or more workstations comprising the machine tool 30.
In this manner, threads are cut in or on each work piece in
accordance with the requirements of a particular machining
operation. The gear box 125 is adapted to move the thread cutting
tools into and out of engagement with the work piece at different
speeds. Typically, disengagement of the thread cutting tools from
the work pieces is carried out at much faster rate as compared with
the actual thread cutting operation.
[0037] Referring to FIG. 9, the machine tool 30 further includes a
spindle drive assembly 130. The variable frequency spindle drive
motor 44 is operatively connected to a shaft 132 through a coupling
135. The shaft 132 drives a gear 136 which drives a gear 138. The
gear 138 in turn drives a gear 140 which drives a ring gear
142.
[0038] The ring gear 142 has an external portion which is driven by
the gear 140 and an internal portion which drives a plurality of
spindle gears 144. The spindle gears 144 each drive a working
spindle 146. As will be understood by those skilled in the art,
lengths of bar stock which are to be machined by the machine tool
30 extend through and are rotated by the working spindles 146 about
longitudinal axes defined by the working spindles 146.
[0039] Referring to FIGS. 10-19, inclusive, the machine tool 30
further comprises a control system 160 which controls both the
speed of the working spindles motor and the speed rotation of the
camshafts. By controlling these functions electronically, a greater
range of feeds and speeds is achieved allowing optimization of the
machine cycle, thus increasing throughput. The motion control
system 160 consists of:
[0040] A Programmable Logic Controller (PLC) 162
[0041] A Machine Management Interface (MMI) 164
[0042] A 2-Axis Motion Module 166
[0043] The Servomotor 46
[0044] The Variable Frequency Spindle Drive Motor 44
[0045] The Servomotor 122
[0046] The PLC 162 monitors machine inputs and outputs, provides
logic solve, and monitors tool-life counters and machine faults.
Spare I/O is allocated for addition of short part detection, broken
tool detection, and other options. The PLC 162 stores cycle data in
a battery backed RAM which is passed to the MMI 164 and motion
module 166 on machine power-up.
[0047] The MMI 164 allows selection of the various operational
modes of the machine tool 30, annunciates faults, sets/monitors
servo positioning and feed-rate, sets/monitors spindle speeds,
displays machine diagnostics, and simplifies programmability of the
machine cycle.
[0048] The motion module 166 controls the profile and feed of the
servo motor rotating the side and end camshafts and the speed of
the main spindle based on numerical data entered via the MMI
164.
[0049] The servomotor 44 drives the side and end camshafts 84 and
74 in a cyclic manor, cycling the machining tools through their
profile. The use of the servomotor 44 eliminates the need for
high/low speed and starting clutches. Positioning of the servomotor
is tracked with the absolute encoder 92.
[0050] The variable frequency spindle drive 44 controls the speed
of the main spindle via input from the MMI, eliminating the need to
change gears to achieve various speeds, as well as allowing for a
greater range of speeds.
[0051] Referring to FIG. 13, the control system 160 provides seven
modes of operation, selectable via the MMI: 164 which are:
[0052] Continuous Jog
[0053] Incremental Jog
[0054] Automatic (Production Mode)
[0055] Dry-Run
[0056] Step
[0057] Setup
[0058] Diagnostic
[0059] The Continuous Jog Mode allows manual jogging of the Side
and End camshafts 84 and 74 at a predetermined speed set by the MMI
164. Rotation of the camshafts allows the machining tools to move
in and out over their cam profile. Jogging of the main spindle
motor 44 is accomplished via a two-position selector switch on the
MMI 164.
[0060] The Incremental Jog Mode allows jogging of the side and end
camshafts 84 and 74 to a preset value (set in cam hundredths)
entered in the MMI 164. Each time the Jog push button at the MMI
164 station is activated, the camshafts will increment the
programmed distance.
[0061] The Automatic Mode (FIG. 14) is the production mode of the
machine tool 30. In this mode, the servomotor 46 cyclically
performs the predetermined profile set via the MMI 164, in turn
cycling the machining tools through their cam profile. Automatic
operation is initiated via the Cycle Start push button on the MMI
164. The machine will continually cycle until the operator presses
the Cycle Stop push button, which stops the cycle with the tools at
the cycle start position (75 cam hundredths).
[0062] The Dry-Run Mode (FIG. 15) operates identically to Automatic
Mode with the exception that the part and tool life counters are
not incremented. The purpose of this mode is to allow warm up of
the machine with out cutting parts. This is achieved by lifting the
collet latch and locking it in the raised position.
[0063] The Step Mode (FIG. 16) steps through the motions of a
cycle, one at a time, to allow inspection of the part at each step
of the process. Each time the Cycle Start push button is pressed,
the cycle will step through the next move, retract the tools to a
clear position, and then stop the spindles. At this time the setup
person may open the cutting chamber door and visually inspect the
parts in the spindle, making adjustments as required.
[0064] The Setup Mode allows the operator to enter data pertaining
to the motion profile desired via the MMI 104. Speeds, feeds, and
positional information are specified, and then passed to the PLC
162 and motion control 166 for execution during the operating
cycle.
[0065] The Diagnostic Mode allows access to items not normally
required by the operator. Items such as machine parameters, I/Q
diagnostics, and drive parameters can be viewed/changed via this
mode. Homing of the machine is also performed in this mode, but the
use of an absolute encoder makes this necessary only when the servo
motor 46 has been removed from the machine.
[0066] The positional units of the Servomotor 46 are specified in
cam hundredths (3.60.degree.). One complete rotation of the
camshaft equates to 100-cam hundredths (3600.degree.). The working
portion of the cycle (low speed) is between 92 and 59 cam
hundredths. The indexing portion of the cycle (high speed) may be
defined between 50 and 92.5 cam hundredths. The setup person will
specify the working and indexing portions of the cycle by defining
these positions in setup mode.
1 Machine Specifications Electrical Specifications 1. Incoming
Power 230 VAC, 60 Amps, 3.o slashed. 2 Control Voltage 24 VDC
Control System Specifications 1. TSX Premium CPU (PLC) TSX-P57102M
2. 26W Power Supply, 110/220VAC TSX-PSY2600M 3. TSX Premium 6 Slot
Rack TSXRKY6 4. 2-Axis Motion Module TSXCAY21 5. 16pt. 24VDC
Discrete Input Module TSXDEY16D2 6. 16pt. 24VDC Discrete Output
Module TSXDSY16T2 7. Modbus Plus PCMCIA Card TSX-MBP100 8. I/O
Module Terminal Strip (2) TSXBLY01 9. Magelis Operator Interface
(MMI) XBT-F011110 10. Magelis PC Cable XBT-Z915 11. PLC Battery
TSXPLP01 Main Spindle Motor Specifications 1 10HP Motor,
208/230/46OVAC,1720RPM Magnetek E357 2. Altivar 58 10HP Variable
Freguency Drive ATV58HD12M2ZU 3. Altivar 58 Modbus Plus
Communication Card VW3-A58302U 4. Dynamic Breaking Resistor
VW3-A66714 Side & End Camshaft Motor Specifications 1 CGP34
Servo Motor, 323 in-lbs S76DE01P010 2. M100D 20 A Cyberline Servo
Drive 610MDC22031 3. 25' CGP Power Cable MC-PSSA-025 4. 25' CGP
Feedback Cable MC-SSSA-025
[0067] All electrical controls are located in a 30"w.times.36"h
.times.12"d machine electrical enclosure. The main operator MMI
station 164 is a 20"w.times.20"h.times.12"d pendant capable of
reaching the front and rear of the machine. Emergency stop push
buttons are located permanently at the front and rear stations.
[0068] Machine I/O Specifications
[0069] Inputs:
[0070] Input Card Slot 1:
[0071] %I1.0-Front Station Emergency Stop Push Button
[0072] %I1.1-Rear Station Emergency Stop Push Button
[0073] %I1.2-MMI Station Emergency Stop Push Button
[0074] %I1.3-Cycle Start Push Button
[0075] %I1.4-Cycle Stop Push Button
[0076] %I1.5-Spindle Jog Selector Switch
[0077] %I1.6-Spare
[0078] %I1.7-Spare
[0079] %I1.8-Coolant/Mist Collector On
[0080] %I1.9-Coolant/Mist Collector Overload Tripped
[0081] %I1.10-Attachment Motor On (Optional)
[0082] %I1.11-Attachment Motor Overload Tripped (Optional)
[0083] %I1.12-Spare
[0084] %I1.13-Spare
[0085] %I1.14-Spare
[0086] %I1.15-Spare
[0087] Input Card Slot 2:
[0088] %I2.0-Low Lube Switch
[0089] %I2.1-Coolant Pressure OK
[0090] %I2.2-Lube Pressure OK
[0091] %I2.3-Broken Cut Off Switch
[0092] %I2.4-Rear Cam Switch (Servo Home)
[0093] %I2.5-Stock Depletion Switch (Optional)
[0094] %I2.6-Broken Tool Detect Switch (Optional)
[0095] %I2.7-Short Part Detected Signal (Optional)
[0096] %I2.8-Collet Latch Raised Switch
[0097] %I2.9-Collet Latch Lowered Switch
[0098] %I2.10-Spare
[0099] %I2.11-Spare
[0100] %I2.12-Spare
[0101] %I2.13-Spare
[0102] %I2.14-Spare
[0103] %I2.15-Spare
[0104] Inputs Via Modbus Plus MMI
[0105] %M-Lube Start/Stop Push Button (from Magelis
[0106] via MB+)
[0107] %M-Coolant Start/Stop Push Button (from Magelis via MB+)
[0108] %M-Jog "+" Push Button (from Magelis via MB+)
[0109] %M-Jog "-" Push Button (from Magelis via MB+)
[0110] %M-Fault Reset Push Button (from Magelis via MB-)
[0111] %M-Main Motor On (from Spindle Drive via MB+)
[0112] %M-Main Motor Overload Tripped (from Spindle Drive via
MB+)
[0113] %M-Short Part Bypass Push Button (from Magelis via MB+)
[0114] Output Card Slot 3:
[0115] %Q3.0-Machine Not In Cycle Stack Light (Red)
[0116] %Q3.1-Machine Fault Stack Light (Yellow)
[0117] %Q3.2-Machine In Cycle Stack Light (Green)
[0118] %Q3.3-Lube Motor Start Relay
[0119] %Q3.4-Coolant/Mist Collector Contactor
[0120] %Q3.5-Attachment Motor Contactor (optional)
[0121] %Q3.6-Collet Latch Raise Solenoid
[0122] %Q3.7-Programmable Air Blast Solenoid (Optional)
[0123] %Q3.8-Short Part "Read" Signal (Optional)
[0124] %Q3.9-Short Part "Reset" Signal (Optional)
[0125] %Q3.10-Spare
[0126] %Q3.11-Spare
[0127] %Q3.12-Spare
[0128] %Q3.13-Spare
[0129] %Q3.14-Scare
[0130] %Q3.15-Spare
[0131] Machine Operation
[0132] Machine Software
[0133] The motion application includes initialization, manual
operation, automatic operation and exception processing. Upon
system power up, the motion controller initializes all system
parameters according to the values held before power down by
polling the PLC register database. Once initialization has been
completed, a mode of operation is selected via the MMI. FIG. 12
displays the various mode selections available.
[0134] The PLC 162 processes I/O and solves logic for power
distribution, air, lubrication, safety interlocks, cycle counters,
cycle timers, and mode selection. A portion of the ladder logic is
devoted to deriving process signals to interlock and coordinate the
ladder logic and motion programs.
[0135] Referring to FIGS. 11 and 12, the MMI 164 is the means of
controlling the machine. The MMI 164 is located on a pendant arm,
which rotates from the front to the rear of the machine. Via the
MMI control panel, the operator can:
[0136] Select machine modes of operation.
[0137] Edit, store, and view various machine parameters.
[0138] Access full system fault monitoring.
[0139] Access help screens available within the MMI.
[0140] Continuous Jog Mode
[0141] When "Continuous Jog Mode" is selected, "Continuous Jog" is
displayed on the MMI 164 to indicate the control is in "Continuous
Jog Mode". While the control is in "Continuous Jog" the jog buttons
on the MMI 164 become active, and the "Cycle Start" and "Cycle
Stop" push buttons become inactive. In this mode, the operator can
jog either the cam axis via push buttons or the main spindle via
selector switch on the MMI 164. Speeds of the cam axis and main
spindle are set in the machine parameters.
[0142] By pressing the "Jog +" or "Jog -" push button, the cam axis
will continually jog at a parameter set speed in the respective
direction until the push button is released.
[0143] Also while in "Continuos Jog", the "Spindle Run-Stop"
selector switch is active. When this switch is in the "Run"
position, the work spindles will continually revolve at a parameter
set speed, until returning the switch to the "Stop" position.
[0144] Incremental Jog Mode
[0145] When "Incremental Jog Mode" is selected, "Incremental Jog"
is displayed on the MMI 164 to indicate the control is in
"Incremental Jog Mode". While the control is in "Incremental Jog"
the jog buttons on the MMI 164 become active, and the "Cycle Start"
and "Cycle Stop" push buttons become inactive. In this mode, the
operator can jog either the cam axis via push buttons or the main
spindle via selector switch on the MMI 164. Speeds of the cam axis
and main spindle are set in the machine parameters.
[0146] In this mode, the operator enters the desired jog increment
Nor the cam axis in the MMI 164 (in cam hundredths), and then
presses either the "Jog +" or "Jog -" push button. The cam axis
will move the programmed jog increment in the respective direction
and stop.
[0147] The spindle jog functions in the same manor as it does in
"Continuous Jog". With the "Spindle Run-Stop" selector switch in
the "Run" position, the work spindles will continually revolve at a
parameter set speed, until returning the switch to the "Stop"
position.
[0148] Auto Mode (FIG. 14)
[0149] When "Automatic Mode" is selected, "Auto Mode" is displayed
on the MMI 164 to indicate the controller is in "Auto Mode". While
the control is in "Auto Mode", the jog buttons on the MMI 164
become inactive, and the "Cycle Start" and "Cycle Stop" push
buttons become active. Provided valid cycle data has been entered
and initial conditions exist, machine cycle will commence once the
"Cycle Star" push button is activated.
[0150] The cycle starts by reversing the cam axis at jog speed to
the cycle start position (75 cam hundredths). The main spindle is
then commanded to cycle speed. Once the spindle reaches speed, the
cam axis will move to the work position at jog speed, and then
begin the profile specified by the cycle data. The servo speeds
used for the two parts of the cycle are calculated based upon the
values entered for the "Work Position", "Work Time", "Index
Position", and "Index Time".
[0151] The machine cycles through the specified profile,
incrementing the "Parts Cut" and "Tool Life" counters, until one of
the following conditions occur:
[0152] An "Emergency Stop" push button is actuated.
[0153] The "Cycle Stop" push button is actuated.
[0154] The "Parts Cut" counter reaches its preset value.
[0155] The "Tool Life" counter reaches its preset value.
[0156] A fault condition exists.
[0157] When an "Emergency Stop" push button is actuated, all motion
ceases immediately. Actuation of the "Cycle Stop" push button, the
"Parts Cut" counter reaching its preset value, or the "Tool Life"
counter reaching its preset value all cause the machine to stop at
the cycle start position (75 cam hundredths) Depending on the
severity of the fault condition, the machine may return to the
cycle start position (75 cam hundredths), or motion may cease
immediately.
[0158] Dry-Run Mode (FIG. 15)
[0159] When "Dry-Run Mode" is selected, "Dry-Run" is displayed on
the MMI 164 to indicate the controller is in "Dry-Run Mode". While
the control is in "Dry Run", the jog buttons on the MMI 164 become
inactive, and the "Cycle Start" and "Cycle Stop" push buttons
become active. Provided valid cycle data has been entered and
initial conditions exist, machine cycle will commence once the
"Cycle Start" push button is activated. This cycle is intended to
warm the machine up before going into production.
[0160] Unlike "Auto Mode", in "Dry Run" the collet latch mechanism
on the chuck and feed cam is raised via solenoid so that stock will
not be fed to the machine. The cycle starts by reversing the cam
axis at jog speed to the cycle start position (75 hundredths), if
necessary. The main spindle is then commanded to cycle speed. Once
the spindle reaches speed, the cam axis will move to the work
position at jog speed, and then begin the profile specified by the
cycle data. The servo speeds used for the two parts of the cycle
are calculated based upon the values entered for the "Work
Position", "Work Time", "Index Position", and "Index Time".
[0161] The machine will continually cycle through the specified
profile identical to "Auto Mode", but the controller will not
increment the "Parts Cut" or "Tool Life" counters. Cycle will
continue until one of the following conditions occur:
[0162] An "Emergency Stop" push button is actuated.
[0163] The "Cycle Stop" push button is actuated.
[0164] A fault condition exists.
[0165] When an "Emergency Stop" push button is actuated, all motion
ceases immediately. Actuation of the "Cycle Stop" push causes the
machine to stop at the cycle start position (75 hundredths).
Depending on the severity of the fault condition, the machine may
return to the cycle start position (75 hundredths), or motion may
cease immediately.
[0166] Step Mode (FIG. 16)
[0167] When "Step Mode" is selected, "Step Mode" is displayed on
the MMI 164 to indicate the controller is in "Step Mode". While the
control is in "Step", the jog buttons on the MMI 164 become
inactive, and the "Cycle Start" and "Cycle Stop" push buttons
become active. Provided valid cycle data has been entered and
initial conditions exist, machine cycle will commence once the
"Cycle Start" push button is activated. This cycle allows the
operator to inspect the part at each step of the process.
[0168] Similar to "Auto Mode", the cycle starts by reversing the
cam axis at jog speed to the cycle start position (75 cam
hundredths). The main spindle is then commanded to cycle speed.
Once the spindle reaches speed, the cam axis will move to the work
position at jog speed, and then begin the profile specified by the
cycle data. The servo speeds used for the two parts of the cycle
are calculated based upon the values entered for the "Work
Position", "Work Time", "Index Position", and "Index Time".
[0169] The machine cycles through one rotation of the cam axis,
performing the specified profile, and then stop, allowing the
operator to inspect the part. By re-activating the "Cycle Start"
push button, the machine will pass through another rotation of the
cam axis and stop. This is continued until the operator is
satisfied that all tools are properly set. The controller will not
increment the "Parts Cut" or "Tool Life" counters in this mode.
[0170] Operation of the machine in Step Mode continues until:
[0171] An "Emergency Stop" push button is actuated.
[0172] The "Cycle Stop" push button is actuated.
[0173] A fault condition exists.
[0174] When an "Emergency Stop" push button is actuated, all motion
ceases immediately. Actuation of the "Cycle Stop" push causes the
machine to stop at the cycle start position (75 hundredths).
Depending on the severity of the fault condition, the machine may
return to the cycle start position (75 hundredths), or motion may
cease immediately.
[0175] Setup Mode (FIG. 17)
[0176] When "Setup Mode" is selected, "Setup Mode" is displayed on
the MMI 164 to indicate the controller is in "Setup Mode". The
machine cycle is controlled via parameter input to the MMI 164.
When the control is in "Setup Mode", these values may be changed.
Valid data must be entered in these parameters before machine cycle
is allowed. Listed below, are the seven parameters related to the
machine cycle:
2 Work Position-the position at which the control commands the cam
axis to work speed (cutting speed). Minimum Value 0.0 cam
hundredths Maximum Value 99.9 cam hundredths Work Time-the amount
of time for the cam axis to travel between the "Work Position" and
"Index Position". Minimum Value 0.40 seconds Maximum Value 60.00
seconds Index Position-the position at which the control commands
the cam axis to index speed. Minimum Value 0.0 cam hundredths
Maximum Value 99.9 cam hundredths Index Time-the amount of time for
the cam axis to travel between the "Index Position" and "Work
Position". Minimum Value 0.40 seconds Maximum Value 2.00 seconds
Main Spindle Speed-the speed at which the spindles will turn during
cycle. Minimum Value 200 RPM Maximum Value 4000 RPM Stock
Position-the position at which the machine will stop when stock
depletion is sensed. Minimum Value 0.0 cam hundredths Maximum Value
99.9 cam hundredths Stock Depletion Check Position-the position at
which the machine will check if stock depletion is sensed. Minimum
Value 0.0 cam hundredths Maximum Value 99.9 cam hundredths Air
Blast Start Position (Optional)-the position at which the optional
programmable air blast will start. Minimum Value 0.0 cam hundredths
Maximum Value 99.9 cam hundredths Air Blast Stop Position
(Optional)-the position at which the optional programmable air
blast will stop. Minimum Value 0.0 cam hundredths Maximum Value
99.9 cam hundredths Parts to Cut-the number of parts to cut for
this job. Cycle will stop upon reaching this value. Minimum Value 1
Maximum Value 99999999 Tool Life End Spindle #1 Counter-the number
of parts before checking tool wear for End Spindle #1. Cycle will
stop upon reaching this value. Minimum Value 1 Maximum Value
99999999 Tool Life Cross Slide #1 Counter-the number of parts
before checking tool wear for Cross Slide #1. Cycle will stop upon
reaching this value. Minimum Value 1 Maximum Value 99999999 Tool
Life End Spindle #2 Counter-the number of parts before checking
tool wear for End Spindle #2. Cycle will stop upon reaching this
value. Minimum Value 1 Maximum Value 99999999 Tool Life Cross Slide
#2 Counter-the number of parts before checking tool wear for Cross
Slide #2. Cycle will stop upon reaching this value. Minimum Value 1
Maximum Value 99999999 Tool Life End Spindle #3 Counter-the number
of parts before checking tool wear for End Spindle #3. Cycle will
stop upon reaching this value. Minimum Value 10 1 Maximum Value
99999999 Tool Life Cross Slide #3 Counter-the number of parts
before checking tool wear for Cross Slide #3. Cycle will stop upon
reaching this value. Minimum Value 1 Maximum Value 99999999 Tool
Life End Spindle #4 Counter-the number of parts before checking
tool wear for End Spindle #4. Cycle will stop upon reaching this
value. Minimum Value 1 Maximum Value 99999999 Tool Life Cross Slide
#4 Counter-the number of parts before checking tool wear for Cross
Slide #4. Cycle will stop upon reaching this value. Minimum Value 1
Maximum Value 99999999 Tool Life End Spindle #5 Counter-the number
of parts before checking tool wear for End Spindle #5. Cycle will
stop upon reaching this value. Minimum Value 1 Maximum Value
99999999 Tool Life Cross Slide #5 Counter-the number of parts
before checking tool wear for Cross Slide #5. Cycle will stop upon
reaching this value. Minimum Value 1 Maximum Value 99999999
[0177] Machine Parameters
[0178] Cam Axis Jog Speed--the speed at which the cam axis will
jog.
[0179] Main Spindle Jog Speed--the speed at which the main spindle
motor will jog.
[0180] Absolute Encoder Offset--the number of encoder counts
required to zero the cam axis.
[0181] Cam Axis Home Position--home position of the cam axis.
[0182] Cam Axis Start Position--the cam axis will travel in reverse
to this position at cycle start.
[0183] Cam Axis Torque Limit--torque limit of the cam axis.
[0184] Main Spindle Gear Ratio--the gear ratio between the main
spindle motor and the center shaft.
[0185] Short Part Read Position (Optional)--the position which
sends the "read" signal to the short part detector option.
[0186] Maintenance Timer Preset--the time interval in hours at
which routine maintenance is required. The machine will
automatically interrupt cycle upon reaching the timer preset.
[0187] Tool Life Warning Period--the number of parts desired as a
pre-warning period before cycle is interrupted by the tool life
counter.
[0188] Machine Diagnostics (FIG. 17)
[0189] Operator Prompting and System Fault Monitoring
[0190] The lower portion of the MMI 164 has been reserved for
operator prompts and fault annunciation. Upon occurrence of any
fault or operator prompt, the system will immediately display a
message on the MMI 164. The operator can clear the message by
pressing the"Message Reset" push button. If the condition still
exists, the message will reappear until cleared by the
operator.
[0191] While the cam axis is moving, whether it is in jog or
automatic operation, the controller will constantly monitor the
torque commanded to the motor. If the torque exceeds the "Torque
Limit" parameter, a fault will occur and immediately halt the cam
axis and shut down the main spindle.
[0192] Counters and Timers (FIG. 17)
[0193] The control system of the machine is equipped with various
counters and timers to monitor tool life, parts cut, maintenance
time, etc. This menu appears when the "Counter Menu" soft key in
the "Diagnostic Menu" is pressed. The counters and timers available
are as follows:
[0194] Parts Counter A--is a general purpose counter that will
simply count the total parts cut since the last time it was reset.
The counter resets via soft key. The operator may use this counter
for anything desired.
[0195] Parts Counter B--is a general purpose counter that will
simply count the total parts cut since the last time it was reset.
The counter resets via soft key. The operator may use this counter
for anything desired.
[0196] Parts Remaining Counter--displays the number of parts
remaining to cut for the active job. The counter is set at compile
to the value entered in the "Parts to Cut" parameter, and will
count down from that value. The counter resets via soft key.
[0197] Cycle Timer--displays the cycle time of parts cut on the
machine.
[0198] Maintenance Timer--displays the time interval in hours since
routine maintenance was last performed. The machine will
automatically Interrupt cycle upon reaching the timers preset which
is set in the machine parameters. The timer resets via soft
key.
[0199] Total Hours of Operation Timer--displays the total hours the
machine has been under automatic operation. This timer will not
reset.
[0200] Tool Life Counter--displays the number of parts remaining to
cut before checking tool wear. The counter is set at compile to the
value entered in the "Tool Life Counter" parameter, and will count
down from that value. A pre-warning period (set by the "Tool Life
Warning Period" parameter) is specified to prompt the operator that
cycle is about to be interrupted. The counter resets via soft
key.
[0201] Referring to FIG. 18, there is shown the stock depletion
operation sequence of the control system 160 of the machine tool
30. When the bar stock which is utilized in the operation of the
machine tool 30 becomes depleted, the stock depletion operation
sequence illustrated in FIG. 18 functions to interrupt operation of
the machine tool 30 to allow the depleted stock to be replaced.
When replacement of the depleted stock has been accomplished, the
stock depletion operation sequence monitors the operation of the
machine tool 30 until a stock depletion condition is again
recognized, whereupon the sequence is repeated.
[0202] FIG. 19 illustrates the control system for the servo thread
cutting assembly 120 which is illustrated in FIGS. 1, 2, and 8, and
described hereandabove in conjunction therewith. As will be
apparent from FIG. 19, the control system 160 of the machine tool
130 does not permit simultaneous turning and tapping of the same
part. It is possible, however, to simultaneously turn one part and
tap a second part, or to simultaneously turn both parts, or to
simultaneously tap both parts. All of the foregoing operations are
regulated and controlled in accordance with the provisions
illustrated in FIG. 19.
OPERATION
[0203] Referring to FIG. 9, operation of the machine tool 30 begins
with the installation of bar stock in of the five working spindles
146. Each length of bar stock is retained by conventional collet
stock. From time to time the lengths of bar stock are moved
longitudinally relative to the working spindles 146 by conventional
stock pushers. The lengths of bar stock received in the working
spindles 140 are rotated about their longitudinal axes by the
variable frequency spindle drive motor 44 with the speed of
rotation being determined by the programming of the control system
160 of the machine tool 30.
[0204] Referring to FIG. 5, the lengths of bar stock received in
the working spindles 146 extend parallel to the cam shaft 84 and
perpendicular to the cam shaft 74. The servomotor 46 operates the
cam shaft 84 to effect rotation of the cams 86. The cams 86 operate
levers which in turn carry tooling adapted to effect machining of
the bar stock. That is, the cams 86 operate through their
respective levers to move the tooling into and out of engagement
with the bar stock as the bar stock is rotated by the spindle drive
motor 44. In this manner the external surfaces of the lengths of
bar stock are machined in accordance with the requirements of a
particular machine operation.
[0205] Similarly, the cams 76 are rotated by the cam shaft 74 under
the action of the servomotor 46. The cams 76 operate levers which
carry tooling suitable for the machining of the lengths of bar
stock received in the working spindles 146. For the most part the
tooling carried by the levers which are actuated by the cam 76 is
utilized to perform drilling, tapping and other internal machining
operations, it being understood that both the tooling carried by
the levers which are actuated by the cams 86 and the tooling
carried by the levers which are actuated by the cams 76 are adapted
for a wide variety of machining operations all of which are well
known in the art.
[0206] Referring to FIG. 7, the servomotor 46 also operates the
indexing mechanism of the machine tool 30. Thus, during each
complete revolution of the cam shaft 84, the indexing mechanism
functions to index the spindle mechanism 106 one step. After five
successive steps, the spindle mechanism 106 has been returned to
its original positioning. In this manner the five lengths of bar
stock which are carried by the working spindles 146 are
successfully moved through five workstations comprising the
machining tool 30.
[0207] The servomotor 46 also rotates the chuck and feed cam 90.
The function of the chuck and feed cam 90 is to open the chucks or
collets which hold the bar stock being machined and to activate the
stock pushers, thereby positioning fresh bar stock for
machining.
[0208] Although preferred embodiments of the invention have been
illustrated in the accompanying Drawings and described in the
foregoing Detailed Description, it will be understood that the
invention is not limited to the embodiments disclosed but is
capable of numerous rearrangements, modification, and substitutions
of parts and elements without departing from the spirit of the
invention.
* * * * *