Patent Grant
11364537
The present invention relates to a method and a flaskless molding line for reducing a mold shift of a cope and a drag that have been molded by a flaskless molding machine and have been assembled.
A conventional flaskless molding machine has been publicly disclosed by which, after a cope and a drag have been simultaneously molded, they are assembled. Then they are stripped from an upper flask and a lower flask so that only the cope and drag are taken out from the molding machine (for example, see Patent Literature 1).
In a flaskless molding line that has such a flaskless molding machine a mold shift of a cope and a drag may occur when operating the line. Conventionally, an operator determines a cause of the mold shift each time a mold shift occurs. Thus, there have been problems, such as a long time being spent for determining the cause or no proper action being taken when the cause is not known.
The present invention was conceived in view of the above problems. The objectives of it are to provide a method for reducing the occurrences of a mold shift of a cope and a drag by estimating the cause of the mold shift based on measurements to take a proper action, and a flaskless molding line that uses that method.
Patent Literature
[Patent Literature 1]
Japanese Patent No. 2772859
To achieve the above-mentioned objects, a method of a first aspect of the present invention, for example, as in
By the above configuration, since the cause of the mold shift is quantitatively estimated based on the specific data obtained at positions where a mold shift may occur to see if the specific data are within an allowable range, a proper action can be taken to reduce the occurrences of a mold shift of a cope and a drag. Here, the “positions where a mold shift may occur” is a position where some operation is carried out during a process for manufacturing or taking out the cope and the drag, such as molding a cope and a drag or transporting a cope and a drag. It denotes a route for transporting a cope and a drag, a means for operating on them, etc. The “specific data obtained at positions where a mold shift may occur” are data that relate to the cause of a mold shift on the route or the means, such as data on adhesion of dirt, an acceleration of means for transporting the cope and drag, etc.
The method of a second aspect of the present invention further comprises, for example, as in
The method of a third aspect of the present invention further comprises, for example, as in
The method of a fourth aspect of the present invention further comprises, for example, as in
By the method of a fifth aspect of the present invention, for example, as in
By the method of a sixth aspect of the present invention, for example, as in
By the method of a seventh aspect of the present invention, for example, as in
By the method of an eighth aspect of the present invention, for example, as in
By the method of a ninth aspect of the present invention, for example, as in
The method of a tenth aspect of the present invention, for example, as in
A flaskless molding line of an eleventh aspect of the present invention comprises, for example, as in
By this configuration, during the process for manufacturing or taking out the cope and the drag that have been manufactured by a flaskless molding machine and assembled, it can be determined in real time if a mold shift has occurred in the current cycle based on whether the specific data that are obtained at positions where a mold shift may occur are within the allowable range. Thus, in the flaskless molding line an action can be quickly taken based on the determination and a mold shift can be prevented in the middle of a cycle.
The flaskless molding line of a twelfth aspect of the present invention, for example, as in
By the flaskless molding line of a thirteenth aspect of the present invention, for example, as in
By the flaskless molding line of a fourteenth aspect of the present invention, for example, as in
By the flaskless molding line of a fifteenth aspect of the present invention, for example, as in
The flaskless molding line of a sixteenth aspect of the present invention further comprises, for example, as in
By the method of the present invention for reducing occurrences of a mold shift of a cope and a drag that have been molded by a flaskless molding machine and have been assembled or by the flaskless molding line of the present invention, the cause of the mold shift is quantitatively estimated based on the specific data obtained at positions where a mold shift may occur. The specific data are determined to see if they are within an allowable range. Thus, a proper action can be taken to reduce the occurrences of a mold shift of a cope and a drag.
The basic Japanese patent application, No. 2017-202337, filed Oct. 19, 2017, is hereby incorporated by reference in its entirety in the present application.
The present invention will become more fully understood from the detailed description given below. However, the detailed description and the specific embodiments are only illustrations of the desired embodiments of the present invention, and so are given only for an explanation. Various possible changes and modifications will be apparent to those of ordinary skill in the art on the basis of the detailed description.
The applicant has no intention to dedicate to the public any disclosed embodiment. Among the disclosed changes and modifications, those which may not literally fall within the scope of the present claims constitute, therefore, a part of the present invention in the sense of the doctrine of equivalents.
The use of the articles “a,” “an,” and “the” and similar referents in the specification and claims are to be construed to cover both the singular and the plural form of a noun, unless otherwise indicated herein or clearly contradicted by the context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the invention, and so does not limit the scope of the invention, unless otherwise stated.
Below the embodiments of the present invention are discussed with reference to the drawings. In the drawings, the same or corresponding members are denoted by the same reference numbers. Thus, duplicate descriptions are omitted. First, with reference to
The means 300 for transporting the cope and the drag places the cope 1 and the drag 2 that have been sent from the flaskless molding machine 200 onto a carriage 310 with a molding board (see
As in
The plate 110 for passing the mold is a flat plate that is located between the plate 210 for receiving the mold and the means 300 for transporting the cope and the drag so that the upper surface of it is at almost the same height as that of the plate 210 and that of the means 300 (in this embodiment, the upper surface of the carriage 310 with the molding board {see
The cylinder 120 for pushing out the mold is shown as being contracted in
At the tip of the cylinder 120 for pushing out the mold the pushing plate 122 is attached to push the cope 1 and the drag 2. The pushing plate 122 has almost the same width (the Y-direction in
A laser-type displacement 140 is provided above the plate 110 for passing the mold and the means 300 for transporting the cope and the drag to measure a step between them. In
A device 160 for blowing air is provided along the plate 210 for receiving the mold and the plate 110 for passing the mold. The device 160 for blowing air has multiple air nozzles 162 to remove fouling that is attached to the upper surface of the plate 210 for receiving the mold and the plate 110 for passing the mold by blowing air. In
With reference to
The flaskless molding machine 200 introduces the molding sand 290 into a space for a cope and a drag that are surrounded by the upper flask 250 (see
As in
As in
The cope 1 and the drag 2 that have been stripped from the upper flask 250 and the lower flask 240 are received by the plate 210 for receiving the mold. The plate 210 for receiving the mold can be vertically moved by means of a cylinder 218 for the plate for receiving the mold. As in
With reference to
The means 300 for transporting the cope and the drag has a scraper 330 to clean the groove and the upper surface of the carriage 310 with the molding board. The scraper 330 has a scraper 332 for the groove that has a steel plate to remove sand, etc., that adheres to the groove on the upper surface of the carriage 310 with the molding board. The steel plate is held by rubber. It also has a scraper 334 for the upper surface that has a steel plate to remove sand, etc., that adheres to the upper surface of the carriage 310 with the molding board. The steel plate is held by rubber. It also has a scraper 336 for finishing that contacts the groove and the upper surface of the carriage 310 with the molding board to carry out the finishing of the cleaning. It also has a touch-activated switch 338, which is the means for measuring fouling on the means for transporting the cope and the drag, to detect fouling on the groove and the upper surface of the carriage 310 with the molding board. The touch-activated switch 338 is a switch wherein, when a protruding object (fouling) adheres to the groove or the upper surface of the carriage 310 with the molding board, a plate inclines by touching the protruding object to contact a needle contact, to detect the fouling. The means for measuring fouling on the means for transporting the cope and the drag may be another known means that can measure a protruding object that adheres to the groove and the upper surface of the carriage 310 with the molding board. It may have a laser-type displacement sensor to measure fouling on the groove and the upper surface of the carriage 310 with the molding board. The laser-type displacement sensor may be similar to the two-dimensional laser-type displacement sensor 124 of the means for measuring fouling on the plate for receiving the mold, the means for measuring fouling on the plate for passing the mold, the means for measuring a difference between the level of the plate for receiving the mold, and the level of the plate for passing the mold, etc.
The scraper 332 for the groove, the scraper 334 for the upper surface, the scraper 336 for finishing, and the touch-activated switch 338, are attached to a bar 344 for suspending the scrapers. The bar 344 for suspending the scrapers is hung from a carriage 342 that slides by means of a lateral cylinder 340 on a rail 351 that is attached to a beam 352 of a frame. The beam 352 of a frame spans a pair of columns 350 of a frame that are disposed at both ends of the beam 352. By contracting and elongating the lateral cylinder 340, the scraper 332 for the groove, the scraper 334 for the upper surface, the scraper 336 for finishing, and the touch-activated switch 338, reciprocate in the width-direction of the carriage 310 with the molding board.
With reference to
It is preferable that both the scraper 330 and the cleaning means 360 are equipped with the means 300 for transporting the cope and the drag of the flaskless molding line 100. If both are so equipped, the scraper 330 or the cleaning means 360 that is located downstream has preferably the means for measuring fouling on the means for transporting the cope and the drag, but this is not essential. The means 300 for transporting the cope and the drag may have either the scraper 330 or the cleaning means 360. If either one is provided, the scraper 330 or the cleaning means 360 has the means for measuring fouling on the means for transporting the cope and the drag. As in
The device 3 for detecting a mold shift as in
As in
Next, with additional references to
A determination that a mold shift has occurred can be carried out as follows. For the cope 1, the distance S1 to the point 1a, the distance S2 to the point 1b, and the distance S3 to the point 1c, are measured by the first means 4 for measuring the distance, the second means 5 for measuring the distance, and the third means 6 for measuring the distance, respectively. The position of the center and the angle of rotation of the cope 1 are calculated based on the measured distances S1, S2, S3.
Next, the device 3 for detecting a mold shift is lowered by a cylinder for moving up and down, which is not shown. Then, for the drag 2, the distance S4 to the point 2a, the distance S5 to the point 2b, and the distance S6 to the point 2c, are measured by the first means 4 for measuring the distance, the second means 5 for measuring the distance, and the third means 6 for measuring the distance, respectively. The measurements up to this measurement are carried out while the cope 1 and the drag 2 stop during the intermittent transportation. The position of the center and the angle of rotation of the drag 2 are calculated based on the measured distances S4, S5, S6.
Next, the coordinates of the four corners of the rectangles are calculated based on the positions of the centers and the angles of rotations of the cope 1 and the drag 2. The horizontal distances between the four corresponding corners of the cope 1 and the drag 2 are calculated. In this embodiment, the allowable range for the horizontal distances is 0.5 mm or less. Thus, the allowance is 0-0.5 mm. The distances of the four corners are checked to see if they are within the allowable range to determine if a mold shift has occurred. In this embodiment, if the distance of any one of the four corners is over the allowable range, a mold shift is determined to have occurred. However, if the distances of two corners, three corners, or all four corners, are over the allowable range, a mold shift may be determined to have occurred. Alternatively, if the mean value or root-sum-square value of the distances of the four corners is over the allowable range, a mold shift may be determined to have occurred. Alternatively, a mold shift may be determined to have occurred by using the distances between the centers and the difference between the angles of rotations.
For the cope 1 and the drag 2 in which no mold shift has been determined to have occurred, the size (the area and the height) of fouling on the plate 210 for receiving the mold that the cope 1 and the drag 2 have passed is measured by the two-dimensional laser-type displacement sensor 124 that is attached to the pushing plate 122, which sensor is the means for measuring fouling on the plate for receiving the mold. At Step 11, the specific data on the size is compared with the allowable range. For example, at first the allowable range is determined to be 25 mm2 or less for the area and 5 mm or less for the height. If the measured values are within the allowable range, go to Step 12 (downward in the flowchart) without any change. In this embodiment when both the area and the height are within the allowable range, the size of the fouling is determined to be within the allowable range. However, this is not essential. If the obtained data are outside the allowable range, air is blown out by the device 160 for blowing air to remove fouling on the plate 210 for receiving the mold. On the returning movement of the cylinder 120 for pushing out the mold (contracting the cylinder), fouling on the plate 210 for receiving the mold is measured. If the fouling remains on the returning movement (the obtained data are outside the allowable range), notify an operator by using a panel, an indicating light, etc. That is, since the fouling cannot be cleaned by only blowing air, an operator is requested to clean the plate 210 for receiving the mold. Then, go to Step 12.
At the next step, Step 12, the data on fouling on the plate 110 for passing the mold, i.e., the size (the area and the height) of fouling as the specific data, are compared with the allowable range. The data on the plate 110 for passing the mold through which the cope 1 and the drag 2 have passed are obtained by the two-dimensional laser-type displacement sensor 124, which is the means for measuring fouling on the plate for passing the mold, which sensor is attached to the pushing plate 122. For example, at first the allowable range is determined as 25 mm2 or less for the area and 5 mm or less for the height. If the measured values are within the allowable range, go to Step 13 (downward in the flowchart) without any change. If the obtained data are outside the allowable range, air is blown out by the device 160 for blowing air to remove fouling on the plate 110 for passing the mold. On the returning movement of the cylinder 120 for pushing out the mold (contracting the cylinder) fouling on the plate 110 for passing the mold is measured. If the fouling remains on the returning movement (the obtained data are outside the allowable range), notify an operator by using a panel, an indicating light, etc. That is, since the fouling cannot be cleaned by only blowing air, an operator is requested to clean the plate 110 for passing the mold. Then, go to Step 13.
At the next step, Step 13, fouling on the carriage 310 with the molding board, as the specific data, is measured by the touch-activated switch 338 of the scraper 330, as the means for measuring fouling on the means for transporting the cope and the drag, to see if fouling exists. If no fouling exists (if the touch-activated switch 338 is off), go to Step 14 (downward in the flowchart) without any change. If fouling exists (if the touch-activated switch 338 is on), notify an operator by using a panel, an indicating light, etc., and request that he or she clean the carriage 310 with the molding board, since the fouling remains after cleaning by the scraper 330 or the cleaning means 360. Incidentally, imaging the upper surface of the carriage 310 with the molding board after cleaning may be used to see if fouling exists.
If fouling exists, the time that has elapsed from the finishing of the pouring to the shake-out is determined to see if it is within the normal cooling time. The fouling, i.e., molding sand, hardens over time. However, if the elapsed time is within the normal cooling time, it can be removed by the scraper 330 and the cleaning means 360. Thus, if the fouling cannot be removed even when the elapsed time is within the normal cooling time, the scraper 330 and the cleaning means 360 are estimated to have deteriorated. For example, if the number of determinations that the fouling cannot be removed even when the elapsed time is within the normal cooling time accumulates, or continuously accumulates to reach five or more times, then notify an operator by using a panel, an indicating light, etc., and request that she or he check the wear of the scraper 330 and the cleaning means 360. If the time that has elapsed from the finishing of the pouring to the shake-out is not within the normal cooling time, for example, being left uncontrolled from a closing time to a starting time of the plant, the operating condition of the scraper 330 has changed, since the fouling has probably hardened. Above, the scraper 330 has been discussed. However, for the cleaning means 360 the speed that the rotating brush 370 rotates may be increased, or the speed of the carriage 310 with the molding board to pass the cleaning means 360 may be decreased. Then go to Step 14.
At the next step, Step 14, the data on fouling on the lower squeezing board 220 that have been obtained by the means 226 for measuring fouling on the lower squeeze board, i.e., the size (the area and the height) of fouling as the specific data, are compared with the allowable range. For example, at first the allowable range is determined as 25 mm2 or less for the area and 5 mm or less for the height. If the measured values are within the allowable range, go to Step 15 (downward in the flowchart) without any change. If the obtained data are outside the allowable range, notify an operator by using a panel, an indicating light, etc., and request that she or he clean the lower squeezing board 220.
If the obtained data are outside the allowable range, a difference between the temperature of the lower squeezing board 220 measured by the thermometer 224 and the temperature of the molding sand (sand for molding) 290 measured by the device 270 for automatically measuring the properties of the molding sand, as the specific data, is determined to see if it is within the allowable range. For example, the allowable range may be determined to be 15° C. or less. When the difference between the temperature of the molding sand 290 and that of the lower squeezing board 220 becomes large, dew may be formed on the surface of the lower squeezing board 220 so that the molding sand 290 easily adheres to the surface. Thus, the difference between the temperature of the molding sand 290 and that of the lower squeezing board 220 is determined to see if it is within the allowable range. If it is within the allowable range, then the molding sand 290 adheres to the lower squeezing board 220 without dew. Thus, notify an operator by using a panel, an indicating light, etc., and request that she or he adjust the content of the molding sand 290, such as active clay and fine powder.
If the difference in temperatures is outside the allowable range, it is determined that molding should be stopped until the difference becomes within the allowable range. If it is determined that the molding be stopped, heat the lower squeezing board 220 by a heater 222 to cause the difference to be within the allowable range. If it becomes within the allowable range, go to Step 15. If molding is not stopped and if the lower squeezing board 220 is not heated by the heater 222, the molding sand 290 is cooled to be, for example, 30° C. or lower, for example, by blowing cooled air toward it. If the temperature of the molding sand 290 reaches the set value or becomes below the set value, return to the step of determining if the difference in temperature is within the allowable range. If the lower squeezing board 220 is not heated by the heater 222 and if the molding sand 290 is not cooled, notify an operator by using a panel, an indicating light, etc., to request that the operator clean the lower squeezing board 220 every cycle. Then, go to Step 15.
At the next step, Step 15, the allowable range is widened for items where fouling has been determined to be outside the allowable range at Step 11-Step 14 or where fouling has been determined to exist, even when no mold shift is determined to have occurred. That is, when no mold shift occurs although fouling that is outside the allowable range exists, the allowable range may be inappropriate. For example, say the allowable range is increased by 10%. In this way, by feeding back a result of the determination on a mold shift, the allowable range can be optimized.
At Step 15, if all data on fouling are within the allowable range, no action is carried out. After Step 15 is finished, return to Step 1 for the next cope 1 and drag 2.
If a mold shift is determined to have occurred at Step 1, go to Step 2, which is shown in
Next, Steps 31-36 as in
At Step 32, impacts on the pushing plate 122 that have been measured by the means 128 for measuring an impact on the pushing plate are determined to see if they are within the allowable range. The measured impacts are impacts in the direction of elongation and contraction of the cylinder 120 for pushing out the mold (the X-direction) and the vertical direction (the Z-direction). Since the means 128 for measuring an impact on the pushing plate that is used at Step 31 is a three-dimensional acceleration sensor, it can be used for measuring the impacts in the X- and Z-directions. If fouling exists on the plate 210 for receiving the mold or the plate 110 for passing the mold on which the cope 1 and the drag 2 are pushed out, or if there is a difference between the level of the plate 210 for receiving the mold and that of the plate 110 for passing the mold or between that of the plate 110 for passing the mold and that of the carriage 310 with the molding board, the cope 1 and the drag 2 receive an impact when they pass over the fouling or the difference in the levels. That impact is transmitted to the pushing plate 122. The impact remarkably appears in the direction for pushing out (the X-direction) and the vertical direction (the Z-direction). Thus, the impacts on the pushing plate 122 show a possibility that fouling exists on the plate 210 for receiving the mold or the plate 110 for passing the mold or a possibility that there is a difference in the levels. The allowable range is, for example, 2G or less. If both impacts on the pushing plate 122 in the X- and Z-directions are within the allowable range, go to the next step, Step 33 (downward in the flowchart). If at least one of the impacts on the pushing plate 122 is outside the allowable range, go to Steps 41-48 as in
At Step 33, the size of fouling on the lower squeezing board 220 is determined to see if it is within the allowable range. If it is within the allowable range, go to the next step, Step 34 (downward in the flowchart). The determination at Step 33 is carried out in a similar way as discussed at Step 14. If it is outside the allowable range, a procedure that is similar to the procedure that is discussed at Step 14 is carried out. Then, go to Step 34.
At Step 34, a waveform of a fluid pressure that drives the cylinder 120 for pushing out the mold, which waveform is measured by the means 126 for measuring a waveform of the cylinder for pushing out a mold, is determined to see if it is within the allowable range. For example, if the fluctuation in the waveform of the fluid pressure during the transportation of the cope 1 and the drag 2 is within ±10% of the normal waveform, it is within the allowable range. If it is within the allowable range, go to the next step, Step 35 (downward in the flowchart). If fouling exists on the plate 210 for receiving the mold or the plate 110 for passing the mold or if there is a difference between the level of the plate 210 for receiving the mold and that of the plate 110 for passing the mold or between that of the plate 110 for passing the mold and that of the carriage 310 with the molding board, a resistance against pushing out the cope 1 and the drag 2 that differs from that at a normal operation occurs. Thus, the fluid pressure fluctuates. Thus, if the waveform of the fluid pressure is outside the allowable range, it is assumed that fouling or a difference in the levels exists at the position that is calculated by the encoder 130. So an operator must be notified and requested to clean or carry out maintenance. Then, go to the next step, Step 35. Incidentally, when the elongation and contraction of the cylinder 120 for pushing out the mold is an electric type, the waveform of the current is measured instead of the waveform of the fluid pressure. When it is an air-pressure type, the waveform of the air pressure in the cylinder 120 for pushing out the mold is measured.
At Step 35, the impact applied to the plate 210 for receiving the mold, which impact has been measured by the means 212 for measuring an impact on the plate for receiving a mold, is determined to see if it is within the allowable range. Here, the impact is a vertical impact (the Z-direction). For example, the allowable range is 2G or less. If the impact is within the allowable range, go to the next step, Step 36 (downward in the flowchart). As discussed with reference to
At Step 36, the position where the impact was detected, or the waveform of the fluid pressure was within the allowable range but was large at Step 31, Step 32, or Step 34, is calculated by the encoder 130 so that the allowable range at that position is narrowed. That is, if that position is the plate 210 for receiving the mold, the allowable range for the size of fouling on the plate 210 for receiving the mold is narrowed. If that position is the step between the plate 210 for receiving the mold and the plate 110 for passing the mold, the allowable range for the difference in their levels is narrowed. If that position is the plate 110 for passing the mold, the allowable range for the size of fouling on the plate 110 for passing the mold is narrowed. If that position is the step between the plate 110 for passing the mold and the carriage 310 with the molding board, the allowable range for the difference in their levels is narrowed. For example, at Step 31 the allowable range is narrowed from 2G or less to 1.9 G or less. Here, the impact or the waveform is regarded as being large when it is, for example, 80% or more, or 90% or more, of the allowable range. Alternatively, it may be the value that has the highest ratio of the obtained specific data to the allowable range. After Step 36, return to Step 1 for checking the next cope 1 and drag 2.
Next, with reference to
At Step 42, the impact on the plate 210 for receiving the mold is determined to see if it is within the allowable range. If it is within the allowable range, go to the next step, Step 43 (downward in the flowchart). If it is outside the allowable range, the operation for stripping the cope and the drag from the flasks is adjusted. Then, go to Step 43. Since at Step 42 the process that is the same as that at Step 35 is carried out, a duplicate discussion is omitted.
At Step 43, the size of the fouling on the plate 210 for receiving the mold is determined to see if it is within the allowable range as at Step 11. If it is within the allowable range, go to the next step, Step 44 (downward in the flowchart). If it is outside the allowable range, the process that is discussed at Step 11 is carried out. Then go to the next step, Step 44.
At Step 44, the size of the fouling on the plate 110 for passing the mold is determined to see if it is within the allowable range as at Step 12. If it is within the allowable range, go to the next step, Step 45 (downward in the flowchart). If it is outside the allowable range, the process that is discussed at Step 12 is carried out. Then go to the next step, Step 45.
At Step 45, it is determined if fouling on the carriage 310 with the molding board exists, as at Step 13. If no fouling exists, go to the next step, Step 46 (downward in the flowchart). If fouling exists, the process that is discussed at Step 13 is carried out. Then go to the next step, Step 46. Incidentally, similar to Step 13, an image recognition of the upper surface of the carriage 310 with the molding board after cleaning may be used to see if fouling exists.
At Step 46, the difference between the level of the plate 210 for receiving the mold and that of the plate 110 for passing the mold that has been measured by the means 124 for measuring a difference between the level of the plate for receiving the mold and the level of the plate for passing the mold is determined to see if it is within the allowable range. For example, the allowable range may be ±0.3 mm or less. If the difference is within the allowable range, go to the next step, Step 47 (downward in the flowchart). If it is outside the allowable range, notify an operator by using a panel, an indicating light, etc., to adjust the stopper bolt 214 of the plate 210 for receiving the mold, to modify the level of the plate 210 for receiving the mold when it is lowered. Alternatively, the operation of an actuator 218 that vertically moves the plate 210 for receiving the mold may be adjusted. Incidentally, the plate 110 for passing the mold is generally fixed so that its level cannot be adjusted. Then, go to the next step, Step 47. Incidentally, instead of measuring the difference between the level of the plate 210 for receiving the mold and that of the plate 110 for passing the mold by the means 124 for measuring a difference between the level of the plate for receiving the mold and the level of the plate for passing the mold, it may be determined if the difference is within the allowable range by measuring the weight of molding sand that has been shaved off when the cope 1 and the drag 2 are pushed out from the plate 210 for receiving the mold to the plate 110 for passing the mold. That is, when they are pushed over the step, i.e., the difference in the levels, the drag 2 is shaved off by the step so that a part of the molding sand drops through the gap between the plate 210 for receiving the mold and the plate 110 for passing the mold. Such molding sand is collected in a container to be weighed by a load cell, etc., to determine the difference in the levels.
At Step 47, the difference between the level of the plate 110 for passing the mold and that of the carriage 310 with the molding board that has been measured by the means 140 for measuring a difference between the level of the plate for passing the mold and the level of the means for transporting the cope and the drag is determined to see if it is within the allowable range. For example, say the allowable range is ±0.3 mm or less. If the difference is within the allowable range, go to the next step, Step 48 (downward in the flowchart). If it is outside the allowable range, notify an operator by using a panel, an indicating light, etc., to modify the level of the rail 320. The main reason to increase the difference between the level of the plate 110 for passing the mold and that of the carriage 310 with the molding board is that the rollers 312 of the carriage 310 with the molding board or the rail 320 has been worn out after being used for a long time. Thus, for example, a spacer (not shown) is inserted under the rail 320 to modify its level. Then, go to the next step, Step 48. Incidentally, similar to Step 46, instead of measuring the difference between the level of the plate 110 for passing the mold and that of the carriage 310 with the molding board by the means 140 for measuring a difference between the level of the plate for passing the mold and the level of the means for transporting the cope and the drag, it may be determined if the difference is within the allowable range by measuring the weight of molding sand that has been shaved off when the cope 1 and the drag 2 are pushed out from the plate 110 for passing the mold to the carriage 310 with the molding board.
At Step 48, the specific data are determined to see if any part of them is outside the allowable range at Steps 41-44, 46, and 47. If all parts of them are within the allowable range, then, since nevertheless a mold shift has occurred (determined at Step 1), the allowable ranges at the positions where the impact has been measured during pushing out the cope 1 and the drag 2 are to be narrowed. For example, at Step 31 the allowable range of 2 G is narrowed to be 1.9 G. The “positions where the impact has been measured during pushing out the cope 1 and the drag 2” are, for example, on the plate 210 for receiving the mold, on the plate 110 for passing the mold, on the carriage 310 with the molding board, or the step between them. Such a position can be determined by the encoder 130. In this way, by determining a position where a cause of a mold shift may exist and by narrowing the allowable range at that position, the allowable range can be modified to achieve an appropriate range. If at least one part of the specific data is outside the allowable range at any of Steps 41-44, 46, and 47, go to Step 1 for the next cope 1 and drag 2.
Next, with reference to the flowchart in
First, at Step 51, the size of the fouling on the lower squeezing board 220 that has been measured by the means 226 for measuring fouling on the lower squeeze board is determined to see if it is within the allowable range. When the mold of the previous cycle has been squeezed, the flasks 240, 250 (see
Next, at Step 52, a difference in the temperature of the lower squeezing board 220 that is measured by the means 224 for measuring the temperature of the lower squeeze board and the temperature of the molding sand 290 that is measured by the means 270 for measuring the temperature of the molding sand is determined to see if it is within the allowable range. The molding sand 290 is conveyed by the conveyor 280, that is, it is to be molded. The allowable range is, for example, 15° C. or less. However, it may be modified at the step of modifying the allowable range. If it is within the allowable range, go to the next step, Step 53 (downward in the flowchart). If it is outside the allowable range, it is determined if molding should be stopped until the difference becomes within the allowable range. If the molding is stopped, the lower squeezing board 220 is heated by the heater 222. When the difference becomes within the allowable range, go to the next step, Step 53. If molding is not stopped and the lower squeezing board 220 is not heated by the heater 222, then, for example, cooling air is blown toward the molding sand 290 so that the temperature of the molding sand 290 becomes, for example, 30° C. or less. When the temperature of the molding sand becomes the set temperature or less, return to the step of determining if the difference in temperatures is within the allowable range. If the lower squeezing board 220 is not heated by the heater 222 and the molding sand 290 is not cooled, go to Step 53. Incidentally, even when the difference between the temperature of the lower squeezing board 220 and that of the molding sand 290 is outside the allowable range, it is possible to go to the next step without any action because of the plan for operating. When molding cannot be stopped due to time constraints, go to the next step even when the fouling may exist on the lower squeezing board 220 when molding the cope 1 and drag 2 at the next cycle. In this case, at Step 51 for the next cycle, the size of the fouling may possibly be outside the allowable range. So an operator should be notified by using a panel, an indicating light, etc., to remove the fouling, etc.
Next, at Step 53, the cope 1 and the drag 2 are molded by the flaskless molding machine 200. After removing the matchplate, the cope 1 and the drag 2 are assembled.
At Step 54, the size of the fouling on the plate 210 for receiving the mold that has been measured by the means 124 for measuring fouling on the plate for receiving the mold is determined to see if it is within the allowable range. Incidentally, at Step 54, the data are used that were obtained when the cylinder 120 for pushing out the mold was caused to contract (in the returning movement) at the previous cycle (the process for the cope 1 and the drag 2 that were molded at the cycle that is previous to the cope 1 and the drag 2 that were molded at Step 53). The allowable range is, for example, 25 mm2 or less for an area and 5 mm or less for a height. However, they may be modified at the step of modifying the allowable range. If it is within the allowable range, go to the next step, Step 55 (downward in the flowchart). If it is outside the allowable range, notify an operator by using a panel, an indicating light, etc., to remove the fouling by blowing air by the device 160 for blowing air or to clean the fouling. Then, go to the next step, Step 55.
At Step 55, the plate 210 for receiving the mold is lifted to contact the bottom of the cope 1 and the drag 2. Next, at Step 56, the cope 1 and the drag 2 in the upper flask 250 and the lower flask 240 are downwardly pushed by the cylinder 230 for stripping the mold through the plate 232 for pushing the mold, to be stripped. At Step 57, the impact that is applied to the plate 210 for receiving the mold when stripping the cope 1 and the drag 2 is measured by the means 212 for measuring an impact on the plate for receiving a mold. When the plate 210 for receiving the mold on which the cope 1 and the drag 2 are placed is lowered to the lowest position, the stripping operation is completed (Step 58). When the stripping operation is completed, go to the next step, Step 59 (downward in the flowchart).
At Step 59 the size of the fouling on the plate 110 for passing the mold is determined to see if it is within the allowable range. The size was measured by the means 124 for measuring fouling on the plate for passing the mold when the cylinder 120 for pushing out the mold was caused to contract at the previous cycle (the process for the cope 1 and the drag 2 that were molded at the cycle that is previous to the cope 1 and the drag 2 that were molded at Step 53). The allowable range is, for example, 25 mm2 or less for an area and 5 mm or less for a height. However, they may be modified at the step of modifying the allowable range. If it is within the allowable range, go to the next step, Step 60 (downward in the flowchart). If it is outside the allowable range, notify an operator by using a panel, an indicating light, etc., to remove the fouling by blowing air by the device 160 for blowing air or to clean the fouling. Then, go to the next step, Step 60.
At Step 60, for example, as in
At Step 61, the difference between the level of the plate 210 for receiving the mold and that of the plate 110 for passing the mold is determined to see if it is within the allowable range. The difference was measured by the means 124 for measuring a difference between the level of the plate for receiving the mold and the level of the plate for passing the mold when the cylinder 120 for pushing out the mold was caused to contract at the previous cycle (the process for the cope 1 and the drag 2 that were molded at the cycle that is previous to the cope 1 and the drag 2 that were molded at Step 53). The allowable range is, for example, ±0.3 mm or less. However, it may be modified at the step of modifying the allowable range. If it is within the allowable range, go to the next step, Step 62 (downward in the flowchart). If it is outside the allowable range, notify an operator by using a panel, an indicating light, etc., to adjust the stopper bolt 214 of the plate 210 for receiving the mold or the actuator of the plate 210 for receiving the mold, i.e., to adjust the operation of the cylinder 218 for the plate for receiving the mold (see
At Step 62, the difference between the level of the plate 110 for passing the mold and that of the upper surface of the carriage 310 with the molding board is determined to see if it is within the allowable range. The difference has been measured by the means 140 for measuring a difference between the level of the plate for passing the mold and the level of the means for transporting the cope and the drag. The allowable range is, for example, ±0.3 mm or less. However, it may be modified at the step of modifying the allowable range. If it is within the allowable range, go to the next step, Step 63 (downward in the flowchart). If it is outside the allowable range, notify an operator by using an indicating light, etc., to adjust the level of the rail 320 for the carriage 310 with the molding board in a similar way as discussed at Step 47. Then, go to the next step, Step 63.
At Step 63, the cope 1 and the drag 2 are pushed out from the plate 210 for receiving the mold to the carriage 310 with the molding board via the plate 110 for passing the mold by means of the cylinder 120 for pushing out the mold. At that time, if the fouling at Step 54 or 59 or the difference in the levels at Step 61 or 62 is within the allowable range but is near the threshold, it is better to push them out at a speed that is slower than the normal speed, to reduce the possibility of a mold shift of the cope 1 and the drag 2. For example, assume that the allowable range is ten and that the cautionary range is 8-9. If a value is in the cautionary range, the motion of the cylinder 120 for pushing out the mold is slowed.
Next, at Step 64, the impacts (the X-direction and the Z-direction) of the cope 1 and the drag 2 are measured while they are being pushed out. The impacts are measured by the means 128 for measuring an impact on the pushing plate that is attached to the pushing plate 122 at the tip of the cylinder 120 for pushing out the mold. The measured values together with the information on the position that is calculated by the encoder 130 are linked to (associated with) the cope 1 and the drag 2 and recorded at the controller 700.
Next, at Step 65, a mold shift is detected by the device 3 for detecting a mold shift, to see if a mold shift occurs. For example, if a misalignment at any of the four corners exceeds the allowable range, it is determined that a mold shift has occurred. However, this is not essential. It may be determined by another method as discussed at Step 1. The allowable range is, for example, 0.5 mm or less. If it is within the allowable range, the cope 1 and the drag 2 are evaluated as having no problem, and are transported (Step 66), so that molten metal is poured into them. Then proceed to the next cycle (Step 67).
If the misalignment is outside the allowable range, a mold shift is considered to have occurred, so that the allowable range for the specific data is narrowed. At the step of preventing a mold shift, the fouling has been removed and the operator has been notified of the difference in the levels (the step), to eliminate the cause of a mold shift at Step 51, Step 52, Step 54, Step 59, Step 60, Step 61, and Step 62. Nevertheless, a mold shift has occurred. Thus, the allowable range has not been appropriate. So, the position where the impact was measured (the plate 210 for receiving the mold, the step between the plate 210 for receiving the mold and the plate 110 for passing the mold, the plate 110 for passing the mold, or the step between the plate 110 for passing the mold and the carriage 310 with the molding board), is determined. The position where the impact occurred while pushing out the mold can be determined by the encoder 130. Alternatively, for the impact applied to the plate 210 for receiving the mold that has been measured at Step 57, the allowable range for it is narrowed. Further, even when the difference between the temperature of the molding sand 290 and that of the lower squeezing board 220 is within the allowable range, the fouling exists on the lower squeezing board 220. Then, notify an operator by using the indicating light, etc., to request that the content of the active clay and the fine powder of the molding sand 290 be modified. If molten metal is poured into the cope 1 and the drag 2 where a mold shift has occurred, instructions are given to carefully check the product on the inspection line. If it is not poured, instructions to change a molding plan are given, since an additional cope 1 and drag 2 must be molded. Then, go to the next step.
Next, with reference to
When the operation is shifted to the step of preventing a mold shift, the number q to count the operations of the step of preventing a mold shift is set to be zero (0). The number p to count the mold shifts even when the obtained data (the specific data) are within the allowable range is set to be zero (0). When the step of preventing a mold shift is carried out, one (1) is added to the number q. If a mold shift occurs even when the obtained data are within the allowable range at the step of preventing a mold shift, one (1) is added to the number p. If the number p exceeds the set number p0 or if the ratio of errors that is calculated by the equation, {the number p to count a mold shift even when the obtained data are within the allowable range/the number q to count the step of preventing a mold shift}, exceed the set value q0, then the operation is shifted to the step of modifying the allowable range. The set number p0 is, for example, 5. The set value (the threshold) q0 for the ratio of errors is, for example, 1%.
This embodiment has a step of estimating the cause of a mold shift during the operation of the flaskless molding line 100. By this configuration, the possibility of a mold shift can be reduced by taking appropriate measures. Further, it has a step of measuring the specific data at the position that may be a cause of a mold shift and a step of optimizing the allowable range to be used to determine if the specific data can be a cause of a mold shift. Thus, the cause of a mold shift can be definitely determined based on numerical data. Further, after the allowable ranges have been optimized, if a cause of a mold shift is found by using the allowable ranges, the operation to eliminate the cause is carried out. Thus, a mold shift can definitely be prevented. After the allowable ranges are determined to be optimized, they are checked to see if they are appropriate, while the operation is carried out. If the allowable range is determined not to be appropriate, the allowable range is again modified. Thus the allowable ranges are maintained to be appropriate.
The sequence of the steps that are above discussed can be arbitrarily changed. The allowable ranges that are above discussed are merely examples, and can be changed depending on the flaskless molding line.
The main reference numbers that are used in the specification and the drawings are listed below.
| Number | Date | Country | Kind |
|---|---|---|---|
| JP2017-202337 | Oct 2017 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2018/026282 | 7/12/2018 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2019/077818 | 4/25/2019 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3556196 | Eugen | Jan 1971 | A |
| 4724886 | Sjodahl | Feb 1988 | A |
| 20180326475 | Sakai | Nov 2018 | A1 |
| Number | Date | Country |
|---|---|---|
| 107848023 | Mar 2018 | CN |
| 2777844 | Sep 2014 | EP |
| H 04181003 | Jun 1992 | JP |
| 2772859 | Jul 1998 | JP |
| 2002-028754 | Jan 2002 | JP |
| 2013-25255 | Dec 2013 | JP |
| WO 2016193790 | Dec 2016 | WO |
| WO 2017122510 | Jul 2017 | WO |
| WO-2017122510 | Jul 2017 | WO |
| Entry |
|---|
| International Search Report for PCT/JP2018/026282 dated Aug. 14, 2018. |
| Office Action in corresponding Application No. JP 2017-202337 dated Aug. 11, 2020. |
| Number | Date | Country | |
|---|---|---|---|
| 20210187598 A1 | Jun 2021 | US |
