WO2011063143A1

WO2011063143A1 - Drive system

Info

Publication number: WO2011063143A1
Application number: PCT/US2010/057270
Authority: WO
Inventors: Randall Lynn Soultz; Daniel Churchill Friday
Original assignee: Marion Glass Equipment And Technology Company Inc.
Priority date: 2009-11-18
Filing date: 2010-11-18
Publication date: 2011-05-26

Abstract

Systems and methods for controlling glassmaking machines containers are described. A system of PLCs generates a series of master virtual axis data and, as a function of that series, generates a series of slave virtual axis data tailored for specific subsystems. The slave virtual axis is electronically "trimmed" (phase-shifted) and/or electronically geared (temporally scaled) to shift and/or scale operation relative to the master virtual axis. The master drive receives feedback from the machines as to the position, velocity, acceleration, and state (e.g., temperature) of their components. It uses that data to consistently check that requested operations are fulfilled and components are operating within the bounds of safety and demanded performance.

Description

DRIVE SYSTEM

Reference to Related Applications

This is an international application based on, and claiming priority to, U.S. Provisional Patent Application No. 61/262,357, filed November 18, 2009, titled "Drive System." This application is also related to U.S. Provisional Application No. 60/864,889 (filed November 8, 2006, with title "Glass Container Forming Controller") and U.S. Patent Application No. 11/937,331 (filed November 8, 2007, with title "Glass Container Forming Controller").

Technical Field

The present disclosure relates to the manufacture or shaping of glass and supplementary processes in the manufacture or shaping of glass. While particularly, it relates to electric or electronic systems for synchronizing or controlling mechanisms specially adapted for glass-blowing machines. The disclosure also relates to automatic electronic controllers that automatically adjust to have performance which is optimum according to some pre-assigned criterion.

Brief Description of Drawings

Fig. 1 is a schematic diagram of a machine for making glass containers for use with an illustrated embodiment.

Fig. 2 is a block diagram of controllers and devices showing signal flow according to one illustrated embodiment.

Fig. 3 is a block diagram of controllers and devices showing signal flow according to a second illustrated embodiment. Description of Embodiments

For the purpose of promoting an understanding of the principles of the present invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will, nevertheless, be understood that no limitation of the scope of the invention is thereby intended; any alterations and further modifications of the described or illustrated embodiments, and any further applications of the principles of the invention as illustrated therein are contemplated as would normally occur to one skilled in the art to which the invention relates.

Generally, the disclosed system controls operations of a glass container forming machine and related peripheral equipment used in the manufacture of glass containers. A main, master drive sends a series of data characterizing a "virtual axis," which herein means a series of data that electronically imitates one or more virtual axes according to its programming and possibly additional inputs. The data are not timing pulses perse, but reflect the state of a virtual motor, including in various embodiments its position, velocity, and/or acceleration at a particular (explicit or implicit) time. Secondary drives may each generate one or more secondary virtual axes based on the series of virtual axis data from the master drive. The secondary drive virtual axis data may be phase-shifted (i.e., temporally shifted ahead or backward) or electronically geared (i.e., scaled in a time domain) relative to the master drive virtual axis data. Receivers of virtual axis data at particular subsystems of the glass container manufacturing system translate the virtual axis data into control information for the real machines. A safety matrix limits the position, speed, acceleration, and other parameters of operation of the machines being controlled to within desired limits.

This illustrated embodiment controls an "individual section" ("IS") machine that implements any of the variety of techniques known for converting a gob of molten glass into a formed article. The present control system (also known as a "drive system") for controlling the position, speed, and acceleration of various components of the glass making system is integrated with an event timing system and synchronizes the position, speed, direction, acceleration, and operational state of various AC and servo motors to position and move the mechanisms correctly. As with any continuous process, each machine has only a certain time window in which to complete each step of its process before the next cycle begins. This "machine cycle" for any given drive may be referenced to a 360° circle, which in many prior systems was a physical drum that rotated and generated timing signals as a function of its position in a 360° rotation. The present system provides controls that are easier to modify and collect state information for signal processing and process controls. Using PLCs makes the system more responsive and accurate in its measurements, which improves safety as well.

Figure 1 illustrates a portion of a container-making process that is controlled by one embodiment of the present control system. In the system, feeder bowl 20 is fed by a continuous supply of molten glass. Feeder

mechanism drive 25 allows one or more streams of molten glass to escape through the bottom of feeder bowl 20. Shears 30 are driven by shear drive 35 to cut each stream into gobs, sometimes two, three, or more at a time, which fall to gob distributor 40. Gob distributor drive 45 rotates gob distributor 40 so that each set of gobs is directed to an IS machine 50. The IS machine 50 forms each gob into a hollow container using techniques that are within the knowledge of those skilled in the art, often including their own timing subsystems, mechanical gearing, and the like. Under the control of IS controllers 55, IS machines 50 form containers and place them onto main conveyor 60, which carries them in the direction of arrow A under the control of main conveyor drive 65.

Beyond the end of the row of IS machines 50, containers on main conveyor 60 encounter ware transfer wheel 70, which is controlled by transfer wheel drive 75. Ware transfer wheel 70 moves containers from main conveyor 60 onto cross conveyor 80, which is controlled by cross conveyor drive 85. Cross conveyor 80 moves the containers in the direction of arrow B toward the stacker 90, which is controlled by stacker drive 95. Stacker 90 ensures that the containers are properly spaced and moves them one row at a time onto lehr conveyor 97. Lehr conveyor 97 takes the formed containers into lehr 99, where the containers are annealed to strengthen the glass, as is known in the art.

Figure 2 illustrates the control structure 100 for this exemplary system. Control system 100 in this embodiment includes drive system 110, which provides virtual axis data to the feeder mechanism drive 25, shear drive 35, gob distributor drive 45, ETimer 150, main conveyor drive 65, transfer wheel drive 75, cross conveyor drive 85, and stacker drive 95. In some embodiments, a master virtual axis data stream is sent from drive system 110 to each of the other drive units, and those other drive units send status information back. The returned status information in various embodiments includes signals acknowledging receipt of the virtual axis data and other communications from drive system 110, signals indicating position of one or more physical components of the device being controlled by the drive, signals indicating the speed or velocity of one or more components of the device being controlled by the drive, signals indicating the acceleration of one or more components of the device being controlled by the drive, signals indicating an alarm or other alert associated with the controlled device, signals indicating one or more other measurements of parameters of operation of the controlled device, and other signals as will occur to those skilled in the art. Drive system 110 uses these return signals and a "safety matrix" to manage the operation of the overall system 10 safely and efficiently, as discussed further herein.

ETimer 150 generates a secondary, synchronized virtual axis, in part as a function of the series of master virtual axis data from the main drive system 110. One or more of the synchronized virtual axis data streams output from ETimer 150 are, in some embodiments, offset from the master feeder virtual axis streams from the master drive 110 with, for example, a fixed-time offset that is automatically generated, with or without an additional "trim"

adjustment input by the operator based on observation of the machine in operation. In this embodiment, which includes a "tandem" IS machine, the master virtual axis from drive system 110 causes a second, synchronized virtual axis to be generated by ETimer 150. ETimer 150 can generate this second virtual axis with a phase offset from the master virtual axis. This secondary virtual axis is also returned to master drive system 110 as information about the timing for the second portion of the tandem machine.

In some embodiments, a mechanical and/or electrical input means is available for operators of the machine to adjust the relative timing of one or more subsystems relative to the synchronized master virtual axis. In some of these embodiments, for example, a knob can be turned, slider moved, or digital control adjusted to set a phase offset for the secondary virtual axis signals going to IS machines 55 relative to the synchronized master virtual axis. In other embodiments, such an adjustment is available at each IS machine 55 to create a phase offset for its operation relative to the primary or secondary virtual axis.

In some embodiments, one or more of the drives are implemented as or with programmable logic controllers (PLCs) and servo and/or AC motors configured to implement the timing features described herein as will occur to those having ordinary skill in the art in view of this disclosure. This

programmability gives the drives the advantage of operation in a mode based on entirely digital timing, a mode that is generally a digital equivalent of classical "timing drum"-based timing, or hybrid thereof. For example, the timing of some synchronization pulses may be governed by a "virtual axis" generated at a particular offset from some other timing axis in the system. In other parts of the system's timing a signal is offset by some number of clock cycles or amount of time. This flexibility, along with application of virtual axis technology, enables systems to have tremendous flexibility and optimized, yet safe operation that has not previously been available in glass container manufacturing systems.

In some systems that use virtual axes, such as that illustrated in Fig. 2, a master drive 110 sends master virtual axis data 111 to slave drives 25, 35, 45, 65, 75, 85, 95, and ETimer 150. Feeder mechanism drive 25 sends feeder slave timing signals 21 to feeder bowl 20, and those slave timing signals can be programmed as a secondary virtual axis that might be a simple pass-through of master virtual axis 111, or might be "trimmed," or adjusted, to be generated either earlier than the master virtual axis is expected to pass a reference phase or after it reaches that phase by some selected amount.

Similarly, drives 35, 45, 65, 75, 85, and 95 send slave virtual axis data 31, 41, 61, 71, 81, and 91 to their respectively controlled devices. Each slave virtual axis may be a passed-through copy of the master virtual axis 111, or may be trimmed (phase-shifted) in time, or electronically geared (time-scaled), or the result of some other function of the master virtual axis and other information as will occur to those of ordinary skill in the art in view of this disclosure.

Likewise, ETimer 150 sends secondary virtual axis data 151 to each IS controller 55, which in turn send distinct IS timing signals 51a, 51b, 51c, 5 Id, 51e, and 5 If to respective IS machines 50. Secondary virtual axis 151 in some embodiments is a virtual axis offset from master virtual axis 111, and the IS timing signals 51a, 51b, etc. can be offset from secondary virtual axis 151.

Using this hierarchical method, such embodiments achieve new flexibility, yet maintain the control, safety, and feedback abilities described herein.

In some embodiments of this system 100, a control panel 112 associated with drive system 110 collects and displays enough information for a control room operator to determine that a change in offset is needed and specify that offset from that control panel. In some of these embodiments, the same synchronized master virtual axis 111 is sent to all subsystem drives 25, 35, 45, 65, 75, 85, 95, and ETimer 150, and any specified offset is applied by the subsystem drive circuitry or mechanism. In other embodiments, as suggested by the architecture shown in Fig. 3, drive system 110 sends a differently timed virtual axis to each subsystem drive.

In many of these embodiments, a significant amount of information is fed back from each machine to master drive 110 regarding the position, speed, acceleration, and condition of various components therein. Similarly, acknowledgments of commands (including, for example, acknowledgments of the synchronized master virtual axis) are returned to master drive 110. A human operator at such a control console 112 can specify a production rate in units such as containers per minute. The system then automatically

determines, based on various combinations of programmed, user-entered, and feedback data, the timing, position, speed, and acceleration of mechanical movements in the system needed to achieve that production rate. In some embodiments, the system is also programmed with a "safety matrix," which defines safe limits on various input and output parameters and combinations thereof. Drive system 110 in these embodiments establishes timing signals and control parameters so that the safety limits are observed, and safely halts operation when bounds are exceeded. Physical limits and control limits of the various components in the system can be observed, too, to maximize

production and efficiency while maintaining equipment reliability and safe operation.

In certain existing technology, glassmaking equipment control systems are either PC-based or use dedicated, embedded control systems.

Communications between machines are either sent through discrete wires or serial communication protocols. Preferred embodiments of the present system, on the other hand, use programmable logic controllers (PLCs) such as the Allen- Bradley ControlLogix family of PLCs.

In some embodiments of the disclosed systems, one or more of the virtual axes that are broadcast pass through fiber optic or Ethernet lines, and the drives are configured in a master-slave relationship. These high-speed connections enable the physical axes of motors and actuators in the various subsystems to remain synchronized, while system engineers and operators can still manipulate each virtual axis with different properties while maintaining reference to the master virtual axis.

All publications, prior applications, and other documents cited herein are hereby incorporated by reference as if each had been individually incorporated and fully set forth. While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered illustrative and not restrictive in character, it being understood that only preferred embodiments have been shown and described, and that all changes and modifications that come within the spirit of the invention are desired to be protected.

Claims

What is claimed is:

1. A system for manufacturing glass containers, comprising:

a master drive that produces a series of master virtual axis data;

a secondary drive that:

receives the master virtual axis data;

sends a series of secondary virtual axis data, representing timing based on the master virtual axis and shifted by a phase adjustment, to an individual section (IS) machine; and sends feedback data about the state of the IS machine to the master controller;

wherein the master drive automatically responds to the feedback data.

2. The system of claim 1, wherein the secondary virtual axis is electronically geared relative to the master virtual axis.

3. The system of claim 1, wherein the phase adjustment is derived from input by a user.

4. The system of claim 1, wherein the master drive and secondary drive are programmable logic controllers.

5. The system of claim 1, further comprising fiber optic lines through which the master virtual axis data and feedback data pass.

6. A method of manufacturing glass containers, comprising:

sending a series of master virtual axis data corresponding to a master virtual axis from a master controller to a slave controller to a plurality of drives; sending a first series of secondary virtual axis data characterizing a first secondary virtual axis from the slave controller to a first set of one or more drives controlling a first set of one or more devices that handle glass or partially manufactured glass containers, at least one of which is an individual section (IS) machine.

7. The method of claim 6, wherein the sending steps include transmitting the master virtual axis data and the secondary virtual axis data through fiber optic media.

8. The method of claim 6, wherein the sending steps include transmitting the master virtual axis data and the secondary virtual axis data through Ethernet media.

9. The method of claim 6, wherein the first series of secondary virtual axis data is effective to control the speed of the one or more devices as a multiple of the speed of the master virtual axis, where the multiple is not one.

10. The method of claim 6, wherein the drives each comprise a PLC.

11. The method of claim 6, wherein the first secondary virtual axis is phase-shifted from the master virtual axis

12. The method of claim 6, further comprising:

sending a second series of secondary timing pulses characterizing a second virtual drive axis to a second set of one or more drives controlling a second set of one or more devices that handle glass or partially manufactured glass containers.