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(11) | EP 0 864 370 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Method for detecting the displacement of a coating pattern and method for correcting said displacement |
| (57) The object of the present invention is to provide a method for detecting the coating
delay inherent in the operation of a spray gun and/or the deviation of the actual
coating pattern from a supposedly ideal coating pattern, and moreover a method for
automatically correcting the coating pattern deviation, when applying a coating material
(16) such as an adhesive or a coating agent by spraying it from a spray gun (3) onto
a workpiece (2) being moved by a conveyer (1) or the like. The method for detecting the displacement of a coating pattern and for the correction of said displacement when spray coating moving workpieces with a coating material from a spray gun is characterized in that the deviation value of the actual coating time from the set coating time value is determined by comparing the set coating time values (T1 and T2) to open and close the spray gun, which have been input in advance in the controller (10) of the coating system, with the actual coating time information (ts and t2) obtained from the sensor (21) used to monitor the state of said spray coating procedure. |
[0001]
[Technical Field of the Invention]
[0001] The present invention pertains to a method for detecting the displacement of a coating pattern and a method for correcting said displacement, in which the coating delay inherent in the spray gun or the deviation of an actual coating pattern from a supposedly ideal coating pattern are detected when applying a coating material such as an adhesive or a coating agent by spraying it from a spray gun onto workpieces being moved by a conveyer or the like, then the deviation is corrected automatically.
[0002]
[Conventional Techniques]
[0002] A conventional method for spray coating moving workpieces with a coating material such as an adhesive or a coating agent from a spray gun will be explained with reference to Figures 4 and 5. In this case, the application of an adhesive as the coating material will be described for the sake of convenience. In the figures, 1 represents a conveyer device, said conveyer device 1 advancing in the direction of the arrow by the application of a driving source which is not illustrated. 2 is a workpiece being moved by the foregoing conveyer device 1, and said workpieces 2 are continuously supplied at given intervals. 3 is a spray gun for spraying an adhesive 5 which is pressure fed from an adhesive feed device 4, toward the workpiece 2. Said spray gun 3 will be described in detail later, but an air-driven spray gun is used as an actual example.
[0003]
[0003] 6 is an electromagnetic valve [solenoid valve? -- Tr. Ed.], said electromagnetic valve 6 turning on and off the supply of air 8 from an air supply 7 for driving the spray gun 3, and thus controlling the operation of the spray gun 3. 9 is a speed sensor for detecting the speed of the conveyer 1, then the signal detected by said speed sensor 9 is input and processed in a control device 10 and monitored by a speed meter incorporated in the control device 10.
[0004]
[0004] 11 is a work sensor that detects the presence of the workpiece 2. Said work sensor 11 senses the leading end of the moving workpiece 2, transmits a signal, then stops transmitting the signal at the point when the workpiece 2 is detected. Furthermore, the work sensor 11 is installed at a position up-stream by a set distance "a" from the location of the center of the nozzle of the spray gun 3, because of structural limitations at the installation site [presumably the limitation is the installation space that is available -- Tr. Ed.]. That is, the distance "a" is the distance between the work sensor 11 and the spray gun 3.
[0005] The structure and action of the aforementioned spray gun 3 are as follows (with reference to Figure 4): If the electromagnetic valve 6 is turned on and air 8 is supplied from the air supply 7 to the spray gun 3, the piston 12 of the spray gun 3 is pushed up against the force of a spring 13, a needle 14 which is directly connected to the piston 12 is also pushed up, the needle valve mechanism is opened, and the adhesive 5 gushes out of the nozzle of the spray gun 3 onto the workpiece 2, and is thus applied to the workpiece 2. 16 indicates the adhesive applied to the workpiece 2.
[0006]
[0006] If the electromagnetic valve 6 is turned off and the air pressure which has kept the piston 12 up is released, the piston 12 is pushed down by the restoring force of the spring 13, the needle valve mechanism is closed, and spraying of the adhesive 5 ends. The restoring force of the spring 13 can be adjusted by the distance that screw 15 is screwed in or out.
[0007]
[0007] An air-driven spray gun is described in this example, however, not only air-driven spray guns but also electromagnetic direct-acting spray guns can be used. It is also true, however, that electromagnetic direct-acting spray guns are disadvantageous from the standpoint of the space they take up, since a large electromagnetic coil is needed to provide a given driving force when handling a fluid of high viscosity and at high pressure such as an adhesive. In contrast to this, air-driven spray guns can be designed to be small and compact, which is advantageous when handling fluids of high viscosity and at high pressure.
[0008]
[0008] When applying an adhesive by a coating device constructed in this way, the speed v of the conveyer 1 is first set with reference to the preceding process and subsequent process, which are not illustrated. This speed v is input to the control device 10 artificially or as a relevant indication signal from the preceding or subsequent process device. The non-illustrated driving device for the conveyer 1 is then adjusted to operate at speed v based on the speed v indication signal from the control device 10. The speed v of the conveyer 1 is monitored by the speed meter in the control device 10 as a signal from the speed sensor 9.
[0009]
[0009] Next, the adhesive coating location of the workpiece 2 is determined. Specifically, a coating start position A that is a certain distance b away from the leading end of the workpiece 2, and a distance "c" over which the adhesive is to be applied to the workpiece 2 are determined. These location values are then input by calculating the time it takes for the coating start position A to advance to a location directly under the spray gun 3 after the leading end of the workpiece has been detected by the work sensor 11, i.e., time T1 during which the coating start position A advances by the distance "a" from the nozzle center position of the spray gun 3 to the work sensor 11, and time T2 (corresponding to distance "c") during which the spray gun 3 is kept open and the adhesive is applied, i.e., the values T1 and T2 are input artificially into the control device 10.
[0010]
[0010] Specifically, the time T1 during which the coating start position A advances to the nozzle center position of the spray gun after the leading end of the workpiece is detected by the work sensor 11, is the distance "a + b" divided by the speed v being monitored by the speed sensor 9, and calculated as
. The time T2 during which the spray gun 3 is kept open, is the distance "c" over which the adhesive is applied divided by the speed v being monitored by the speed sensor 9, i.e., it can be calculated as
.
[0011]
[0011] Once these values, i.e., the speed v, time T1, and time T2, have been set in the control device 10, the coating work begins. If the leading end of the workpiece 2 is detected (i.e., a trigger signal is generated) by the work sensor 11, the control device 10 transmits an "open" signal to the electromagnetic valve 6 after time lapse T1 after the leading end of the workpiece 2 has been detected, which opens the electromagnetic valve 6. The air 8 for driving the spray gun 3 is then supplied to the spray gun 3; the piston 12 of the spray gun 3 is pushed up against the force of the spring 13; the needle 14 directly connected to the piston 12 is also pushed up and the needle valve mechanism is opened; and the adhesive 5 gushes out of the nozzle of the spray gun 3 onto the workpiece 2 and is thus applied to the workpiece 2.
[0012]
[0012] When time T2 elapses from the start of coating, the control device 10 ceases actuation of the electromagnetic valve 6 and thus turns off the electromagnetic valve 6, so that the air pressure which has kept the piston 12 up, is released, the piston 12 is pushed down by the restoring force of the spring 13, the needle valve mechanism is closed, and coating with the adhesive is terminated.
[0013]
[0013] In this way, one work cycle of applying the adhesive is completed. Then, when the work sensor 11 detects the leading end of the next workpiece 3 [sic; 2? -- Tr. Ed.] (i.e., a trigger signal is generated), another work cycle of the aforesaid coating is begun, and said work cycles are repeated until the work is interrupted.
[0014]
[Problems to be Solved by the Invention]
[0014] However, various problems are associated with the coating method mentioned above. For example, and even though the coating process must be started at a position which is distance b away from the leading end of the workpiece 2, i.e., coating start position A, and even though the coating must be applied over distance "c", the actual coating process starts the coating pattern where the start of coating is delayed by distance "d" with respect to the intended coating start position A, and ends the coating pattern with the end of coating being delayed by distance "e" with respect to the intended coating end position B, as shown in Figure 4.
[0015]
[0015] Displacements of the coating pattern of this kind are inherent to the use of the spray gun. They are caused by factors such as the time it takes for the piston 12 to be pushed up against the force of the spring 13 after the driving air is supplied. In the case of an air-driven spray gun, the sliding resistance of the piston 12 and the needle 14, the distance "h" from the nozzle tip to the workpiece, and the pressure of the coating fluid, tend to vary in a delicate and indirect manner due to the passage of time and/or friction. Accordingly, even a spray gun produced under the best quality control conditions cannot avoid this delay in the coating time, even though there are some differences from one individual product to another. A coating delay of this kind also occurs even if an electromagnetic direct-acting spray gun is used, although there are some differences in the delay value.
[0016]
[0016] This shifting of the coating pattern causes the same delay times when seen in terms of time, but does not vary with respect to a change in [the conveying] speed. However, when seen in terms of the magnitude of the delay, i.e., in terms of the coating pattern, the displacement of the coating pattern appears to be proportionately larger with respect to the speed as the production speed increases. Furthermore, apart from the operational delay of the actual spray gun, there can even be a displacement of the coating pattern due to factors such as system failure. Recently, even higher speeds are being sought after from the standpoint of productivity, and pattern displacements of the kind discussed above are the notable causes of lower quality in products that require coating quality of high precision. Clearly, then, improvements are sorely needed.
[0017]
[0017] In order to remedy these problems caused by coating pattern displacements, the following method has already been used: a trial coating run is carried out and the results are examined visually by the worker. The distance of the delay from the ideal coating position to the actual coating position is measured and used to calculate the delay time, then time T1 and time T2 that have been set in the control device 10 are corrected manually by the worker. Operations like this take a lot of time and labor, e.g., a tremendous amount of time used to be required when starting production of a new product, changing the coating pattern, or repairing or exchanging the spray gun. Furthermore, visual examination can be difficult depending on the type of workpiece and/or the type of coating material, which make it difficult to make highly accurate corrections.
[0018]
[0018] The present invention was developed in response to these problems, thus the goal of the present invention is to provide a method for detecting the coating delay inherent in the use of a spray gun and/or the displacement of an actual coating pattern from a supposedly ideal coating pattern, and also to provide a method for automatically correcting said displacement, when applying a coating material such as an adhesive or a coating agent by spraying it from a spray gun onto workpieces being moved by a conveyer or the like.
[0019]
[An Approach to Solving the Problems]
[0019] To solve the aforementioned problems, the following methods have been developed and make up the present invention. In a method for spray coating moving workpieces with a coating material from a spray gun, the present invention pertains to a method for detecting the displacement of the coating pattern, characterized in that the deviation value of the actual coating time from a set coating time value is determined by comparing the set coating time values to open and close the spray gun, which have been set in advance in a device for controlling the coating device, with the actual coating time information obtained from a sensor used to monitor the state of the spray coating procedure.
[0020]
[0020] Also, in a method for spray coating moving workpieces with a coating material from a spray gun, the present invention pertains to a method for correcting the displacement of the coating pattern, characterized in that the deviation value of the actual coating time from the set coating time value is determined by comparing the set coating time values to open and close the spray gun, which have been set in advance in a device for controlling the coating device, with the actual coating time information obtained from a sensor for monitoring the state of the spray coating procedure; and in that said controlling device is configured so as to output a spray signal to the spray gun by altering the set coating time value by the determined deviation.
[0021]
[Mode of Carrying Out the Invention]
[0021] The mode of carrying out the present invention will now be described. The present invention pertains to a method for detecting the displacement of a coating pattern and a method for correcting said displacement as part of a method for spray coating moving workpieces with a coating material from a spray gun by the procedure mentioned earlier, and hence can provide a spray coating method of extremely high quality with no coating delay. Specifically, the set coating time value at a line speed v that has been set in a control device for a coating line, based on the design value for a coating pattern, i.e., time (T1) until the spray start signal is output to the spray gun after the workpiece is detected by the work sensor, and time (T2) during which the spray gun is carrying out the spray coating process, are compared with the actual coating time information (ts and t2) obtained from a sensor used to monitor the state of the coating spray process in accordance with the above-mentioned times, then the respective deviations are determined, whereby the displacement of the coating pattern can be detected. Moreover, the positional deviation value of the coating pattern is fed back to the set coating time value, then the set coating time value is shifted and modified by said deviation value, whereby the ideal coating pattern can always be obtained automatically.
[0022]
[Actual Example]
[0022] The invention method for detecting the displacement of a coating pattern and the method for correcting said displacement in a method for spray coating moving workpieces with a coating material from a spray gun will now be described in concrete terms with reference to the figures which show an actual example of these methods. Figure 1 is an explanatory diagram which illustrates the principal components needed to carry out the present invention. Figure 2 is an explanatory perspective diagram which illustrates the principal components of the present invention, similar to those of Figure 1. Figure 3 is a diagram which illustrates the various operations involved in the coating work of the present invention as time charts. Parts which have the same function as in the conventional technique are given the same symbols, and will be described as simply as possible.
[0023]
[0023] Furthermore, the case of applying an adhesive as the coating material will be described here for the sake of convenience, as in the explanation of the conventional technique described previously. In Figures 1 and 2, symbol 1 represents a conveyer device, and said conveyer device 1 is made to advance in the direction of the arrow by a driving source, which is not illustrated. 2 is a workpiece being moved by the foregoing conveyer device 1, and said workpieces 2 are continuously supplied at given intervals. 3 is a spray gun for spraying an adhesive 5 which is pressure fed from an adhesive feed device 4, toward the workpiece 2. Said spray gun 3 will be described in detail later, but an air-driven spray gun is used as one actual example.
[0024]
[0024] 6 is an electromagnetic valve, and said electromagnetic valve 6 turns on and off the supply of air 8 from an air supply 7 for driving the spray gun 3, and thus controls the operation of the spray gun 3. 9 is a speed sensor for detecting the speed of the conveyer 1, then the signal detected by said speed sensor 9 is input and processed in a control device 10, and monitored by a speed meter incorporated in the control device 10. In this case, a speed sensor that is configured to transmit the number of pulses in proportion to the speed or the moving distance is suitable as the speed sensor 9.
[0025]
[0025] 11 is a work sensor that detects the presence of the workpiece 2. Said work sensor 11 detects the leading end of the moving workpiece 2, transmits a signal (trigger signal), then stops transmitting the signal at the point when the workpiece 2 is no longer detected. Furthermore, the work sensor 11 is installed at a position upstream by distance "a" from the location of the center of the nozzle of the spray gun 3, because of structural limitations at the installation site. That is, the distance "a" is the distance between the work sensor 11 and the spray gun 3.
[0026]
[0026] 21 is a sensor used to monitor the adhesive 16 being applied to the surface of the workpiece 2. Said sensor 21 detects the leading end of the adhesive 16 applied on the surface of the workpiece 2, transmits a signal, then stops transmitting the signal at the point when the adhesive 16 is no longer detected, i.e., the application of the adhesive is ended. Furthermore, the sensor 21 is installed at a position downstream by distance "f" from the location of the center of the nozzle of the spray gun 3, because of structural limitations at the installation site. That is, the distance "f' is the distance from the spray gun 3 to the sensor 21.
[0027]
[0027] The structure and action of the aforementioned spray gun 3 are as follows (with reference to Figure 1): If the electromagnetic valve 6 is turned on and air 8 is supplied from the air supply 7 to the spray gun 3, the piston 12 of the spray gun 3 is pushed up against the force of a spring 13, a needle 14 directly connected to the piston 12 is also pushed up, the needle valve mechanism is opened, and the adhesive 5 gushes out of the nozzle of the spray gun 3 onto the workpiece 2, and is thus applied to the workpiece 2. 16 indicates the adhesive applied to the workpiece 2, i.e., a coating pattern. If the electromagnetic valve 6 is turned off and the air pressure which has kept the piston 12 up is released, the piston 12 is pushed down by the restoring force of the spring 13, the needle valve mechanism is closed, and the spraying of the adhesive 5 ends. The restoring force of the spring 13 can be adjusted by the distance that screw 15 is screwed in or out.
[0028]
[0028] An air-driven spray gun is described in this example, however an air-driven spray gun is not the only choice, e.g., an electromagnetic direct-acting spray gun may also be used. It is also true, however, that electromagnetic direct-acting spray guns are disadvantageous from the standpoint of installation space, since a large electromagnetic coil is needed to provide a given driving force when handling a fluid of high viscosity and at high pressure such as an adhesive. In contrast to this, air-driven spray guns can be designed to be small and compact, which is advantageous when handling fluids of high viscosity and at high pressure.
[0029]
[0029] When applying an adhesive by a coating device constructed in this way, the speed v of the conveyer 1 is first set with reference to the preceding process and subsequent process, which are not illustrated. This speed v is input to the control device 10 artificially or as a relevant indication signal from the preceding or following process device. The nonillustrated driving device for the conveyer 1 is then adjusted to operate at speed v based on the speed v indication signal from the control device 10. The speed v of the conveyer 1 is monitored by the speed meter in the control device 10 as a signal from the speed sensor 9.
[0030]
[0030] Next, the adhesive coating location of the workpiece 2 is determined. Specifically, a coating start position A that is a certain distance "b" away from the leading end of the workpiece 2, and a distance "c" over which the adhesive is to be applied to the workpiece 2 are determined. These location values are then input by calculating the time it takes for the coating start position A to advance to a location directly under the spray gun 3 after the leading end of the workpiece has been detected (i.e., a trigger signal is transmitted) by the work sensor 11, i.e., time T1 during which the coating start position A advances to directly below the nozzle by the distance "a" from the work sensor 11 to the nozzle center position of the spray gun 3, and time T2 (corresponding to distance "c") during which the spray gun 3 is kept open and the adhesive is applied, i.e., the values T1 and T2 are input artificially into the control device 10.
[0031]
[0031] Specifically, the time T1 during which the coating start position A advances to the nozzle center position of the spray gun after the leading end of the workpiece is detected by the work sensor 11, is the distance a + b divided by the speed v being monitored by the speed sensor 9, and calculated as
. The time T2 during which the spray gun 3 is kept open, is the distance "c" over which the adhesive is applied divided by the speed v being monitored by the speed sensor 9, i.e., it can be calculated as
.
[0032]
[0032] Furthermore, time T1 and time T2 may be calculated by the arithmetic function of the control device 10, by feeding the distance data (magnitude), i.e., distances a, b, and c, directly into the control device 10. These values, i.e., speed v, time T1, and time T2 are set in the control device 10 as basic data, and stored in a memory device in the control device 10.
[0033]
[0033] Next, the control device 10 calculates a coating pattern such that the intended ideal adhesive coating pattern is shifted to a location based on the sensor 21 which monitors the state of the coating procedure. In this case, the valve to be determined by calculation is the time Ts it takes the start point A of the adhesive to be applied to reach the location of the sensor 21 after the trigger signal.
[0034]
[0034] In concrete terms, time Ts during which the coating start position A advances to the location of the sensor 21 after the leading end of the workpiece is detected (i.e., a trigger signal is transmitted) by the work sensor 11, is the distance
divided by the speed v being monitored by the speed sensor 9, and can be calculated as
.
[0035]
[0035] Here, Ts may be calculated by the arithmetic function of the control device 10 by feeding the distance data (magnitude) a, b, c, and f directly into the control device 10 in much the same way as the aforementioned time T1 and time T2. This value, i.e., time Ts, is set in the control device 10 as basic data and thus stored in a memory device in the control device 10.
[0036]
[0036] When coating work begins and the leading end of the workpiece 2 conveyed by the conveyer 1 is detected by the work sensor 11, the controller 10 transmits an open signal to the electromagnetic valve 6 after the lapse of time T1 after the leading end of the workpiece 2 has been detected, and opens the electromagnetic valve 6. The air 8 for driving the spray gun 3 is then supplied to the spray gun 3; the piston 12 is pushed up against the force of the spring 13; the needle 14 directly connected to the piston 12 is also pushed up and the needle valve mechanism is opened; and the adhesive 5 flows out of the nozzle of the spray gun 3 with great force onto the workpiece 2, and is thus applied to the workpiece 2.
[0037]
[0037] When time T2 elapses from the start of coating, the controller 10 stops the actuation of the electromagnetic valve 6 and turns off the electromagnetic valve 6, so that the air pressure which has kept the piston 12 up, is released. The piston 12 is then pushed down by the restoring force of the spring 13, and the needle valve mechanism is closed, so that coating of the adhesive ends.
[0038]
[0038] When the adhesive actually applied on the surface of the workpiece 2, i.e., the coating pattern 16, advances to the location of the sensor 21 used to monitor the state of the coating procedure, the sensor 21 will detect the leading end of the adhesive 16 and transmits a signal. The controller 10 then measures time ts from the trigger signal, i.e., the detection of the workpiece 2 by the work sensor, to the detection of the leading end of the adhesive 16 by the sensor 21. If the sensor 21 detects the terminal end of the adhesive 16 in a similar manner and the signal transmission of the sensor 21 is stopped, the coating time t2 from the actual start of coating of the adhesive on the workpiece 2 to the completion of coating is measured.
[0039]
[0039] In the controller 10, the measured time ts is compared with the previously set and stored time Ts, and the difference Δt1 between these two is calculated as an arithmetic operation. Similarly, the time T2 and time t2 are compared, and their difference Δt2 is calculated. That is,
(which corresponds to d in the figure), and
are calculated. The values Δt1 and Δt2 are thus displacement information on the coating pattern.
[0040]
[0040] If the value of Δt1 or Δt2 deviates from the value determined in advance, the operation is judged as a coating error, and the signal thereof can be used as an information signal to turn on an alarm lamp, or to stop the line, or to remove the subject workpiece downstream from the production line as a product to be rejected.
[0041]
[0041] Furthermore, if the adhesive is not applied at all for some reason, such as system failure, no signal will be produced from the sensor 21; accordingly, the values Δt1 and Δt2 will not be calculated. The arithmetic function of the controller 10 can be set up so as to also judge a case of this kind as a coating error, and then output an error signal.
[0042]
[0042] These relationships are illustrated in Figure 3. In other words, Figure 3 shows the various coating work operations in the form of time charts, where "i" [i, ro, ni, ho, etc. are essentially characters in the Japanese syllabary -- Tr. Ed.] shows the operation of the work sensor 11, where the signal rise point x works as the trigger signal. "Ro" shows the intended coating pattern, which is designed so that an open signal will be sent to the electromagnetic valve after the time lapse T1 from the trigger signal x, and a close signal will be sent to the electromagnetic valve after time T2. "Ha" shows the actually sprayed and coated state from the spray gun, where d and e indicate deviations from the intended coating pattern values. "Ni" shows the state where the intended coating pattern is shifted to the location of the sensor 21, where Ts indicates the time from the trigger signal x to the time the leading end of the ideal coating pattern reaches the location of the sensor 21. "Ho" shows the operation of the sensor 21, where ts indicates the time from the trigger signal x to the time the sensor detects the actual coating start position, and t2 indicates the time from the actual coating start detected by the sensor 21 to the end of the coating process.
[0043]
[0043] And the aforementioned Δt1 and Δt2 are displacement information on the coating pattern, and at the same time Δt1 and Δt2 are also the correction times for the next coating cycle. Δt1 is fed back as the correction time for time T1 during which the coating start position A advances to the nozzle center position of the spray gun after the leading end of the workpiece has been detected by the work sensor 11, and time T1 is automatically corrected. Also Δt2 is fed back as the correction time for time T2 during which the spray gun 3 is kept open, and time T2 is automatically corrected.
[0044]
[0044] In other words, if the value of Δt1 is minus, the value of T1 is decreased by that fraction, and the open signal of the electromagnetic valve is forwarded by the value of Δt1; if the value of Δt1 is plus, the value of T1 is increased by that fraction, and the open signal of the electromagnetic valve is delayed by the value of Δt1. Similarly, if the value of Δt2 is minus, the value of T2 is decreased by that fraction, and the close signal of the electromagnetic valve is forwarded by the value of Δt2; and if the value of Δt2 is plus, the value of T2 is increased by that fraction, and the close signal of the electromagnetic valve is delayed by the value of Δt2.
[0045]
[0045] In this way, one cycle of the work of applying the adhesive ends, and when the work sensor 11 detects the leading end of the next workpiece 3 [sic; 2? -- Tr. Ed.] (i.e., a trigger signal is generated), the aforesaid coating cycle is started again. And this time the coating work is carried out with the values corrected by the previous coating cycle, i.e., T1 + (Δt1) and T2 + (Δt2), then these T1 + (Δt1) and T2 + (Δt2) values are stored temporarily in the controller 10 until the next correction command signal is input. Then, when the next correction signal is input, these values are replaced by the latest values corrected by that signal.
[0046]
[Advantages of the Invention]
[0046] As described above, the present invention can detect the deviation value of the actual coating time from the set coating time value as coating pattern displacement detection information, by comparing the actual coating time obtained from the sensor used to monitor the state of the coating procedure, with the set coating time value of the spray gun that has been input in the controller for a system for spray coating moving workpieces with a coating material from a spray gun, and can also automatically correct the coating delay or coating pattern deviation in the spray coating method, because it is arranged so as to output open and shut signals to the spray gun from the controller by automatically shifting and correcting the set coating time values by the deviation values, thus coating work of high quality, which always conforms to the intended coating pattern values, can be carried out.
[Brief Description of the Figures]
[Figure 1]
[0047] An explanatory diagram which illustrates the principal components of the invention method needed for spray coating moving workpieces with a coating material from a spray gun.
[Figure 2]
[0048] An explanatory perspective diagram which illustrates the principal components of the invention method needed for spray coating moving workpieces with a coating material from a spray gun.
[Figure 3]
[Figure 4]
[0050] An explanatory diagram of a conventional method for spray coating moving workpieces with a coating material from a spray gun.
[Figure 5]
[0051] An explanatory perspective diagram of a conventional method for spray coating moving workpieces with a coating material from a spray gun.
[Description of the Symbols]
[0052] (1) conveyer device; (2) workpiece; (3) spray gun; (6) electromagnetic valve; (9) speed sensor; (10) controller; (11) work sensor; (16) coating material applied; (21) sensor; (a) distance from the work sensor to the spray gun; (b) intended distance from the leading end of the coating material to the coating start position; (c) intended distance from the coating start position to the coating end position; and (f) distance from the spray gun to the sensor.
1. In a method for spray coating moving workpieces with a coating material from a spray
gun, a method for detecting the displacement of the coating pattern, characterized
in that the deviation value of the actual coating time from the set coating time value
is determined by comparing the set coating time values to open and close the spray
gun, which have been set in advance in a device for controlling the coating device,
with the actual coating time information obtained from a sensor for monitoring the
state of the spray coating procedure.
2. In a method for spray coating moving workpieces with a coating material from a spray
gun, a method for correcting the displacement of the coating pattern, characterized
in that the deviation value of the actual coating time from the set coating time value
is determined by comparing the set coating time values to open and close the spray
gun, which have been set in advance in a device for controlling the coating device,
with the actual coating time information obtained from a sensor for monitoring the
state of the spray coating procedure; and in that said controlling device is configured
so as to output a spray signal to the spray gun by altering the set coating time value
by the determined deviation.
[Detailed Description or the Invention]
[Detailed Description or the Invention]