JPS6149255B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to glass manufacturing equipment and, more particularly, to a control system for monitoring and controlling the processing of glass sheets in a glass processing environment.

Curved tempered glass is widely used in the side and rear windows of vehicles to increase vandal resistance and to complement and aesthetically complement the shape of the vehicle opening and the overall design of the vehicle. ing. Furthermore, if there are scratches or defects on the surface of the glass sheet where you look out, you will not be able to clearly see outside through the window, so such surfaces must be free of scratches and defects.

To bend and strengthen a glass sheet, heat the glass sheet to approximately 566°C to 649°C (1050°C to
The glass must be heated to a deformation temperature point of 1200°), bent into the desired shape, and quickly cooled with a jet of air to strengthen the glass. Strengthening in this way significantly increases the mechanical strength and fracture resistance of the glass, and even if it breaks, it will not break as large as non-strengthened glass, but into relatively small, sharp pieces.

No. 4,282,026, entitled "Apparatus for Bending and Strengthening Glass," dated Aug. 4, 1981, is incorporated herein by reference. The patent discloses a glass transport apparatus that includes a furnace, the housing of which defines a heating chamber for heating the glass while it is being fed along a roller hearth conveyor. The upwardly open lower part of the furnace housing and the fixed roof of the furnace housing together with the vertically movable side door form a heating chamber. The lower ends of the doors meet with the upper ends of the side walls in the lower portion of the housing to form side slots through which the ends of the elongated conveyor rolls project outwardly from the heating chamber. The ends of the conveyor rolls are supported by continuous drive loops in the form of chains or solid steel belts, which are slidably driven on external support surfaces extending laterally in the slots to support and friction the rolls. Drive. A vacuum holder is arranged above the conveyor roll in the heating chamber and has a downwardly facing inner surface in which narrow openings are provided at certain distances. A vacuum is drawn within these narrow openings to receive the heated glass sheet from the conveyor and support the glass sheet on the conveyor, ready for bending the glass sheet.

Prior art patents disclose glass sensors that sense the position of individual glass sheets transported by a glass transport mechanism in a glass processing environment without the need for mechanical contact with the glass sheets.
For example, US Pat. No. 3,372,016 to Rahrig et al. discloses providing a glass sheet-sensing photocell in the cooling region of a glass sheet strengthening and conveying device. Similarly, Stickel et al., US Pat. No. 3,459,529, discloses providing a glass sheet bending device with a photocell in the bending region to sense the glass sheet. US Pat. No. 3,522,029 to Carson et al. discloses placing a glass sheet sensing photocell near the heating area of a glass sheet shaping device.

The aforementioned U.S. patent, entitled "Apparatus for Bending and Strengthening Glass," discloses a photoelectric sensor for sensing moving sheets of glass, which uses a heater that heats the glass sheets as they are carried by a conveyor. placed indoors.

In order to precisely determine the position of the glass sheet so that it can be processed and/or placed under automated control without causing damage to the glass sheet or the glass processing equipment, it is necessary to The glass sheet must be accurately sensed as it moves through the processing environment. For example, in order to simultaneously pick up a pair of glass sheets from the conveyor and place them side by side when the conveyor is in constant operation, the position of the pair of glass sheets must be precisely known.

It is an object of the present invention to provide an improved control system for monitoring and controlling the processing of conveyed glass sheets in glass processing systems operating at relatively high production rates, both for glass sheets and for glass bending and strengthening systems. It is an object of the present invention to provide a control system with signal processing means that allows a glass bending and strengthening system to bend and strengthen glass sheets without causing damage.

To achieve this objective, the control system of the present invention comprises sensor means positioned along the conveying path to sense the glass sheet as it is conveyed by the roller conveyor of the glass processing system. ing. The sensor means generates a glass sense signal upon sensing each glass sheet. The control system of the present invention also includes signal generating means connected to the roll conveyor for generating a transport signal corresponding to the distance that the glass sheet is conveyed along the transport path. processing the glass sensing signal and the transfer signal to generate a control signal to a roll actuator of a glass processing system for actuating a plurality of rolls on a roller conveyor adjacent to the glass bending apparatus to control the movement of the rolls and the glass sheet thereon; Signal processing means are also provided for controlling the conveying condition of the glass sheets on the other rolls of the conveyor, regardless of the conveying condition of the glass sheets on the other rolls of the conveyor.

In a preferred embodiment, the sensor means includes an energy source arranged on one side of the glass transport path for generating radiant energy across the glass transport path, and a glass transport for receiving the generated radiant energy. and an energy receiving device located on the opposite side of the road.

Preferably, said signal processing means generates a control signal to said roll actuator such that it can initially adjust a downstream glass sheet relative to its corresponding upstream glass sheet as required.

The sensor means is positioned at a predetermined position along the length of the heating chamber downstream of the glass loading station to sense the glass sheet as it is being transported. The signal processing means is responsive to the glass sensing signal and the transfer signal of the sensor means to move each sensed glass sheet to the glass pick-up device without causing damage to either the glass bending equipment or the glass sheet at the glass bending station. Generates control signals to the glass bending equipment and roll actuators of the system to be picked up.

Preferably, the signal processing means is a programmable data processor capable of accepting various set points corresponding to various physical parameters of the glass bending and strengthening system from an interconnected operator console.

A number of advantages are achieved when this type of control system of the invention is applied to glass bending and strengthening applications. First of all, the number of hardware and control equipment in the furnace environment is minimized, i.e. the glass processing environment is only equipped with sensor means, including a photoelectric sensor pair, and signal generation means, including an incremental encoder. All other controls of the control system, including the operator console and other various control circuits, which are not required, can be located away from the furnace environment, eg, in an operator control room. Second, for this intended use, the control system of the present invention provides considerable flexibility, i.e., the position of the photoelectric sensor pair can be varied along the length of the conveyor, thus requiring no hardware. The set points used by the control system can be varied so that they do not need to be changed.

Objects, features and advantages of the invention will become apparent from the following detailed description of embodiments of the invention, taken in conjunction with the accompanying drawings.

1 and 2, the glass loading device 11, which monitors the position of the glass sheet,
Roll actuator 13, glass bending equipment, and a pair of glass bending ring and cooling units 12 and 14
A control system according to the present invention for controlling a glass processing apparatus such as is indicated generally by the reference numeral 10. Glass conveying equipment is equipped with roll shifters or roll positioning drives, both of which were introduced in 1981.
No. 310,332 entitled “Roll Actuator for a Glass Sheet Conveyor in a Glass Bending System,” filed October 13, 2013 (U.S. Pat. No. 4,360,374)
It is of the general type disclosed in No.
When the roll actuator 13 takes the form of a roll shifter, the roll shifter generally includes a roll connector 15 and an associated actuator 16 for actuating the roll connector to shift the shiftable roll 26'.

When roll actuator 13 takes the form of a roll positioning drive, this positioning drive generally includes a continuous drive loop 15 and an associated drive for driving this drive loop 15 to rotate roller 26'. mechanism 16.

As mentioned above, in glass bending and strengthening applications, a pair of glass sheets G and
The roll actuator 13 is configured to substantially reduce relative movement between the roll actuator 13 and G' to prevent roll damage.
The operation of is controlled by a control system 10.
The operation of repositioning the leading glass sheet G and the trailing glass sheet G' with respect to each other in order to prepare them for simultaneous bending can also be done by shifting the leading glass sheet G with respect to the trailing glass sheet G'. can be done.

Glass bending apparatus 17 is of the general type disclosed in US Pat. No. 4,282,026, entitled "Apparatus for Bending and Strengthening Glass," dated August 4, 1981.

Such a glass processing system includes a furnace 18 . This furnace 18 receives at a loading station 20 individual glass sheets to be bent and strengthened. Furnace 18 is configured to once heat the glass and then bend the glass at bending station 22 as disclosed in the aforementioned patent entitled "Apparatus for Bending and Strengthening Glass."

The conveyor is indicated generally by the reference numeral 24 and includes a plurality of conveyor rolls 26 of fused silica particles sintered together.

A continuous drive loop 28 in the form of a chain or solid steel belt rests on the pulley 30.
At one end of the conveyor 24, a pulley 30 is connected to a driven pulley 31 by a cross shaft 32. The drive mechanism 34 drives the pulley 30 by a digital drive motor such as a DC motor 36. A pulley 35 is attached to the shaft 37 of the motor 36, and the pulley 35 is connected to the pulley 35 and the pulley 31. chain 3 hanging on
8 so that the drive loop 28 is pulled over the support surface and thus both ends of the roll 26 are frictionally driven.

As can be seen in FIG. 2, the vacuum holder 40 of the apparatus 17 is placed in the heating chamber of the furnace at the glass bending station 22. Vacuum holder 40, described in detail in the above-referenced patent entitled "Apparatus for Bending and Strengthening Glass", is a vacuum holder that bends two sheets of glass at a time by using a vacuum at a glass take-up or bending station. receive. The vacuum holder 40 is raised and lowered by a holder lifting unit 44 of the glass taker 17, which unit is of the general type disclosed in the aforementioned patent entitled "Apparatus for Bending and Strengthening Glass."

Glass loading device 11 typically supports a pair of glass sheets G and G' on a horizontal conveyor 24 and then transfers the sheets G and G' onto conveyor 2.
The glass loader 41 is equipped with a glass loader 41 for unloading the glass. Each glass loader 41 has a glass sheet G
and G', to a retracted position for lowering the glass sheets G and G' onto the conveyor 24. Each support actuator (not shown) is actuated by air directed along line 50 from a compressed air source 52, which is actuated by control system 10.

Control system 10, in its preferred form, includes a commercially available incremental encoder 56 mounted on shaft 37 of motor 36 to sense the angular displacement of shaft 37. This incremental encoder 56 can withstand the normal high operating temperatures in a furnace environment. Due to the high temperature of the furnace environment, encoders using semiconductor components are generally unsuitable.

Incremental encoder 56 generates a glass transport signal on line 58 in the form of a shaft position signal.
The incremental encoder 56 is connected to the shaft 3 of the motor 36.
7 is the glass sheet, for example 0.25mm (0.01 inch)
It generates a shaft position signal in the form of a pulse each time it rotates sufficiently to cause movement.

The shaft position signal from incremental encoder 56 is received by a programmable control computer or unit 88. The control computer 88 uses the shaft position signal as an interrupt request signal to decrement various timing counters in its RAM memory in response to the movement of the conveyor 24. In particular, when control computer 88 receives a shaft position signal from encoder 56 indicating forward movement of conveyor 24, various timing counters within control computer 88 are counted down. Other functions and operation of control computer 88 are discussed below.

Control system 10 also includes a photoelectric sensor pair 62. The sensor pair 62 includes an energy radiating source unit 66 electrically connected to a power source 70 to generate radiated electromagnetic energy in the form of a modulated infrared energy beam, and by a mounting assembly 67. It is removably mounted on one side of the conveyor 24. Sensor pair 62 also includes an energy receiving unit 72 adapted to receive and respond to a predetermined threshold level of modulated infrared energy generated by source unit 66 and mounted. It is removably attached to the opposite side of conveyor 24 by assembly 76 . If the modulated infrared energy received by this receiving unit 72 is less than a predetermined level, then
A glass sensing signal is generated by this receiving unit 72. The signal generated by this receiving unit 72 is then demodulated by a demodulator 80 and input to the control computer 88 in a form that the control computer 88 can understand. Receiving unit 72 includes a phototransistor that receives and is responsive to the modulated infrared energy generated by source unit 66. Source unit 66 includes a photodiode that emits modulated infrared energy that is received by receiver unit 72.

Photodiodes and phototransistors using modulated infrared energy are particularly suitable for sensing glass in glass processing environments.
For example, such phototransistors are insensitive to incoming infrared energy generated by the sun, light bulbs, or other heat sources such as furnace 18.

An operator interface in the form of a teletype unit 87 or an operator console inputs the following data to a control computer 88: Rolls 2 whose glass sheets can be controlled individually by actuating roll actuators 13.
a first set of numerical data corresponding to the longitudinal distance between the position on 6' and the photoelectric sensor 72, the bending position relative to the downstream glass sheet (i.e.
a second set of numerical data corresponding to the longitudinal distance between the photoelectric sensor 72 and the position at which the glass bending device 17 lifts or removes the downstream glass sheet from the conveyor 24; and the glass loading station 20 and the glass bending station 20; A third set of numerical data corresponding to the required distance between the pair of glass sheets G and G' at both positions.

As previously mentioned, the operator begins operation of the control system by first entering various set points into the control unit 88 via the teletype 87. Information or data entered by teletype 87 is accepted by block 92, which includes an input/store routine. The software represented by block 92 accepts the following information from the teletype 87: the first set of numerical data, the glass sheet as it is first placed on the conveyor 24 by the glass loader 11; the distance between the energy receiving unit 72 and the bending position of the glass bending device 17; and the desired distance between the pair of glass sheets.

When the operator enters this data into the control system and conveyor 24 begins to operate, the output from encoder 56 appears on line 58 and is processed by block 94, an interrupt encoder processor. This interrupt encoder processor 94
starts the operation of the various counters in the software by first resetting them. When the glass transfer signal from encoder 56 is sensed along line 58, control is automatically switched to interrupt encoder processor 94 and all counters connected to interrupt encoder processor 94 are sensed along line 58. is decremented each time an encoder pulse is received. Once all counters connected to the interrupt encoder processor have been decremented, control is returned to the software interrupt routine.

After the conveyor 24 has moved the distance set by the operator as described above, the load/track routine in block 96 sends a load control signal to the glass loader 11 along line 98. The set value is stored in a RAM memory (not shown) and read from this RAM memory into a counter (not shown) in block 96;
This is done by interrupt encoder processor 94 after each pair of glass sheets G and G' is unloaded onto conveyor 24.
is reduced by

At the same time that the load control signal is sent to the loader 11, the load/track routine 96 flags the RAM tracking buffer 100. This RAM tracking buffer 100 is a FIFO (first in, first out) buffer that determines whether a pair of glass sheets G and G' unloaded onto the conveyor should be bent in the first glass bending ring/cooling unit 12 or in the second glass bending ring/cooling unit 12. The glass bending ring/cooling unit 14 indicates whether the glass should be bent. At the same time that the RAM tracking buffer 100 is flagged by the load/track routine 96, any old flags previously present in the RAM tracking buffer 100 are removed.

Thereafter, the loading/tracking routine 96 continues to load glass sheet pairs G and G' by controlling the glass loader 11 and each loaded glass sheet pair G and G' is stored in the RAM tracking buffer 100. .

When the first downstream glass sheet G is sensed by the radiant energy receiving unit 72, a glass sense signal is generated by the unit 72, which signal is received by the glass detection routine 102. This glass detection routine 102
The infrared energy reception of the unit 72 is cut off during conveyor travel for a predetermined number of inches in order to prevent the infrared energy reception of the unit 72 from being cut off by an undersized glass sheet or other object. Preferably, it includes a software filter to determine whether or not the The glass detection routine 102 also determines whether the infrared energy beam is detected by the unit 7 until it is again interrupted by the upstream glass sheet G' or another object.
2 also includes a software filter for determining whether infrared energy has been received during at least a predetermined number of inches of conveyor travel. In this way, even if there is a wobble in the advancement of the glass sheet and infrared energy is momentarily received by unit 72, the signal from unit 72 will be transmitted to the upstream glass sheet G'. Control unit 8 to mean immediately after G
8 will not be misjudged.

When the glass detection routine 102 determines that a glass sheet has been detected, a flag for that pair of glass sheets is placed in the RAM by the load/track routine 96.
removed from tracking buffer 100. The glass type detection routine 104 detects whether the pair of glass sheets should be bent by the first glass bending ring and cooling unit 12 or by the second glass bending ring and cooling unit 14. The routine 102 is instructed.

The glass detection routine 102 performs the first glass bending routine 102 after determining whether the bending operation is to be performed on either the first or second glass bending ring and cooling units 12 and 14 according to the flags set in the RAM tracking buffer. Ring/cooling unit 12
or second glass bending ring/cooling unit 14
A ring/cooling control signal is sent to either of the two.
A control signal is sent on either line 105 or 107 depending on whether units 12 or 14 are selected.

When the glass detection routine 102 determines that a downstream glass sheet G is detected, the glass detection routine 102 sets the G position counter 106 to accurately track this downstream glass sheet.
The glass detection routine 102 detects a glass sheet.
Once we determine that we have detected G′, we use this same information as
G′ position counter 108 is input. Additionally, the glass detection routine 102 detects the upstream glass sheet.
When G' is detected, the glass detection routine 102
picks up the distance between the unit 62 and the position of the vacuum holder 40 that picks up the glass sheet G' at the upstream position and inputs it into the counter 110.

A position counter tracks both glass sheets to a position such that the downstream glass sheet G is on roll 26' and the upstream glass sheet G' is approaching but has not yet reached roll 26'. When this occurs, a spacing correction value is calculated by the roll actuation routine 114. This determines the actual spacing between both glass sheets from the position counters G and G',
This is done by comparing the setpoint values already entered by the teletype. Appropriate control signals are generated on line 112 from the roll actuation routine 114. This control signal actuates roll actuator 13, which actuates roll 26' to modify the spacing between glass sheets G and G'.

When both glass sheets G and G' are on roll 26', roll actuation routine 114 starts at line 1.
12 to generate an appropriate second control signal. This signal causes roll actuator 13 to actuate roll 26' to prepare for a slow stroke cycle. The pick counter 110 is modified to represent the distance the glass is moved by this pre-slow stroke.

When the pick up counter 110 counts up to zero, the pick up routine 116 returns to line 1.
18 to the holder lifting unit 44 for generating a pick control signal. As pick up counter 110 counts down to zero, roll actuation routine 114 starts on line 11.
2 to the roll actuator 13 so that the roll 26' moves the upstream glass sheet shown in FIG. Relative movement between glass sheets G and G' is substantially reduced, preventing scratches on the glass and reducing wear on vacuum holder 40. This is described in detail in the aforementioned patent application entitled "Roll Actuator for a Glass Sheet Conveyor in a Glass Bending System."

After the slow cycle when glass sheets G and G' are picked up, but before the next glass sheet reaches roll 26', roll actuation routine 114 generates a fourth control signal on line 112. , causes the roll actuator 13 to move the roll 26' to a central "home" position so that it is ready for another cycle when the roll actuator 13 assumes the form of a roll shifter.

In this way, the control system 10 controls the glass loading apparatus 11 by monitoring the glass sheets G and G' and controlling their processing with high precision.
Coordinates the operation of the glass processing machine, including the roll actuator 13, the glass bending apparatus 17, and the glass bending ring and cooling units 12,14.

In summary, the present invention provides important advantages over control systems other than the present invention. The first effect is that only a limited number of elements are placed and operated within the furnace environment. Most control hardware is located remote from the furnace environment, such as in a process control room. A second advantage of the present invention is the flexibility of the control system when the control system of the present invention is applied to such purposes. In particular, the sensor pair 62 can be repositioned along the length of the conveyor 24 and the control system 10 can still function without extensive hardware changes. Additionally, the position of the glass loading station can be changed along the length of the conveyor 24 without extensive hardware changes. The third effect of the present invention is that the conveyor 24 is stopped and the conveyor 24 is
The control system of the present invention allows for accurate monitoring of the position of pairs of glass sheets on conveyor 24 so that the glass sheets do not need to be picked up from the conveyor.

Although the present invention has been described above, it should be understood that the terms used herein are for descriptive purposes only and are not intended to be limiting. Although many changes and modifications of the invention may be made from the above description, it is intended that all changes and modifications made within the spirit and scope of the invention be encompassed within the scope of the following claims.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the control system of the present invention combined with a glass bending and strengthening system, FIG. 2 is a top view of the control system of the present invention combined with a glass bending and strengthening system, and FIG. FIG. 3 is a diagram showing a control program executed by the control system of the invention. 10... Control system of the present invention, 11... Glass loading device, 13... Roll actuator, 12, 14
...Glass bending ring/cooling unit, G,
G'...Glass sheet, 17...Glass bending device, 18...Furnace, 20...Glass loading station, 22...Glass bending station, 24...
Conveyor, 26, 26'... Roll, 28... Drive loop, 30... Pulley, 34... Drive mechanism,
40... Vacuum holder, 41... Glass loader, 4
4... Holder lifting unit, 47... Housing, 56... Incremental encoder, 62... Sensor pair, 88... Control computer.

Claims (1)

[Claims] 1. Processing of a glass sheet in a glass processing system in which the glass sheet is conveyed by a horizontal roller conveyor, and the glass sheet is received from a certain roll of the roller conveyor by a glass bending device to bend the glass sheet. A control system for monitoring and controlling the control system, the control system being disposed along the conveying path of the glass sheet and comprising a sensor means and a signal generating means connected to the roller conveyor, the sensor means being connected to the roller conveyor. detecting the glass sheet as the glass sheet is conveyed by the roller conveyor past the roller conveyor and generating a glass sensing signal upon sensing the glass sheet, said signal generating means being configured to detect the glass sheet as it is conveyed by the roller conveyor; processing the glass sensing signal and the transport signal corresponding to each glass sheet in a control system adapted to generate a corresponding transport signal;
A control signal is generated to a roll actuator of the glass processing system that operates a plurality of rolls adjacent to the glass bending apparatus, thereby controlling the movement of the rolls and the conveyance of the glass sheet thereon. A control system comprising programmable signal processing means for controlling the conveyance state of the glass sheet on the roll regardless of the conveyance state of the glass sheet. 2. The processing of glass sheets in a glass processing system in which the glass sheets are conveyed on driven rolls of a horizontal roller conveyor, and the glass sheets are vertically removed from one roll of the roller conveyor by a glass bending device and bent. A control system for monitoring and controlling the process, the control system comprising sensor means disposed along the conveying path of the glass sheet and signal generating means connected to the roll conveyor; detecting the glass sheet as the glass sheet is conveyed by the roller conveyor past the roller conveyor and generating a glass sensing signal upon sensing the glass sheet, said signal generating means being configured to detect the glass sheet as it is conveyed by the roller conveyor; In a control system adapted to generate a corresponding transfer signal,
Processing the glass sensing and transfer signals corresponding to each glass sheet to provide control signals to the glass bending apparatus and a roll actuator of the glass processing system that operates a plurality of rolls adjacent the glass bending apparatus. and thereby controlling the glass bending apparatus to remove each glass sheet from the adjacent rolls substantially reducing relative horizontal movement between each glass sheet and the glass bending apparatus. A control system characterized by comprising a signal processing means as described above. 3. Each pair of glass sheets is conveyed by the driven rolls of a horizontal roller conveyor and removed from one roll of this roller conveyor by a glass bending device, which rolls each pair of glass sheets into an elongated heating chamber. monitoring the relative position of pairs of glass sheets in a type of glass bending and strengthening system in which the glass sheets of each pair are transported along their length to a glass bending station where each pair of glass sheets is lifted by said glass bending apparatus; and a control system for controlling the heating chamber, the control system comprising: sensor means disposed at predetermined positions along the length of the heating chamber; and signal generating means connected to the roller conveyor; senses the glass sheet as it is conveyed by the conveyor and generates a glass sensing signal, and the signal generating means generates a transport signal corresponding to the distance that the glass sheet is conveyed along the conveyor path. a roll of the glass bending and strengthening system configured to process the glass sensing and transfer signals corresponding to each respective glass sheet to operate a plurality of rolls adjacent the glass bending apparatus; generating a control signal to an actuator for causing a downstream glass sheet of a pair of glass sheets to be supported by the adjacent rolls to move the downstream glass sheet to a desired position relative to the upstream glass sheet; a program for controlling the movement of the adjacent rolls and the conveying state of the glass sheet thereon, regardless of the conveying state of the glass sheet on the other rolls of the conveyor, so as to appropriately pick up the pair of glass sheets; 1. A control system characterized by comprising a signal processing means of the formula. 4. The sensor means comprises an energy emitting source placed on one side of the glass sheet conveyance path and an energy receiving device placed on the opposite side of the conveyance path to receive the radiated energy, the receiving device 4. A control system as claimed in claim 1, 2 or 3, wherein the glass sensing signal is generated when the receipt of energy thereby is interrupted by a glass sheet. 5. The signal generating means comprises encoder means associated with the output shaft of the drive motor of the roller conveyor, the encoder means generating a signal representative of the angular displacement of the output shaft. 3. The control system according to item 1 or 3.