JPH03155455A - Flaskless type casting line - Google Patents

Abstract

PURPOSE:To accurately take out a casting by measuring upper face of a sand mold with a temp. measuring instrument, deciding the position at the specific distance from one end of the remaining high temp. range removed with high range component as sprue center and taking out a casting. CONSTITUTION:The sand mold upper face temp. measuring instrument 3 measures the surface temp. of flaskless sand mold 51. By removing the high temp. range in the outputted signal, influence of less high temp. material caused by flowing out of molten metal is eliminated and the position at the specific distance from the one end of the high temp. range in the remaining output is decided as the center position of sprue 54. By this method, the influence of low temp. material caused by covering of the sand can be eliminated. A micro computing unit 4 shifts the pulling-out device 2 to the optimum pulling-out position, and by working arms 22, 23, casting design part 56 in the casting A is held and pulled up to take out the casting. As the taking-out position of casting A is accurately estimated, even if there are the various kinds of variations, the product can be surely taken out without damaging the product.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a frameless casting line, and more particularly to a frameless casting line that allows good casting removal.

[Prior art] In a conventional frameless casting line, a sand molding machine, a pouring machine, a casting removal device, a sand recovery machine, etc. are arranged along a conveyor device that is operated at intervals, but the working environment is hot. The situation is not good from the viewpoint of safety and dust, and for this reason, automation of the work has been expected in recent years.

Various types of conventional casting removal devices are known.

The casting removal equipment currently in common use includes a drum cooler located at the end of the conveyor system. When a sand mold is put into this rotating drum cooler, the sand mold is separated into castings and sand. In addition, a casting removal device is also in practical use that separates the casting from the sand by dropping the sand mold onto a photographic sieve provided at the end of the conveyor device.

Also, Utsukai Showa 63-6146.163260゜1700
The device disclosed in Japanese Patent No. 66.252666 has a casting removal device disposed facing the terminal end of the conveyor device, and this casting removal device has a placing arm that is pierced into the sand mold portion below the casting, and It has a pressing arm that sticks into the upper sand mold part. When taking out the casting, after sticking the eight arms into the zero, both arms are relatively moved in a direction close to each other to grip the casting in the vertical direction, and then both arms are rotated or translated in a horizontal plane. and taking out the castings.

[Problems to be Solved by the Invention] However, in a casting removal device that uses a drum cooler or a vibrating screen, the posture and position of the castings to be removed are unstable.
The next hand picking of the castings (for example, placing them on a casting conveyor) could not be automated and had to be done manually. As a result, workers are forced to work under a poor environment.

The casting removal devices disclosed in the above-mentioned publications are intended to solve the drawbacks of the casting removal devices described above and take out castings in a constant posture, but they have the following problems.

The first problem is that the resting position of the sand mold changes with the interval operation of the conveyor device. That is, the individual sand molds constituting the frameless sand mold row are compressed in the transport direction by the impact force at the time of starting and stopping during transport. Furthermore, the distance traveled by the conveyor device at one time is not strictly constant, and as a result of this, the resting position of the sand mold that has reached the bottom of the casting extraction device varies. If the resting position of each sand mold changes under the casting removal device, even if the extraction arm always sticks into the sand mold by a constant depth, the relative position of the extraction arm and the casting in the transport direction will become unstable, causing problems in subsequent handling. Problems arise. For example, when placing a molded casting on a casting conveyor, it is difficult to place the casting unless the casting is always gripped at a certain position (generally at the tip) of the handling arm. Furthermore, there are cases where the casting in the sand mold is incompletely caught by the handling arm, and in this case too, the casting fails to be removed.

The second problem is that openings, shifts, and collapses may occur at the boundaries between the individual sand molds that make up the frameless sand mold row, as shown in Figure 5, which may result in misalignment of the casting. This may result in failure in ejection or damage to the casting by the handling arm.

The third problem is that the casting removal device is configured to grip the casting (particularly the product part) with a large gripping force in the vertical direction and remove it from the sand mold, so the handling arm may damage the casting. It is a certain thing.

This probability increases if the casting surface to be gripped is not flat in the horizontal direction or if the area of the casting surface to be gripped is insufficient. Furthermore, when casting many types of castings using different sand molds on the same flaskless casting line, it is not easy to grasp the castings each having a different shape.

The present invention has been made in view of these problems, and an object of the present invention is to provide a frameless casting line that can reliably take out castings from sand molds in a certain posture that is advantageous for handling, and that does not damage the castings. is the issue that needs to be solved.

[Means for Solving the Problems] The frameless casting line of the present invention includes a conveyor device that intermittently conveys a frameless sand mold row consisting of a plurality of sand molds connected in a line in the advancing direction and each having a sprue, and the conveyor. a casting extraction device that is disposed at the end of the device and includes a scooping arm that extracts the casting from the sand mold; and a sand mold that is disposed close to the upstream side of the casting extraction device in the conveying direction and includes a sprue. a sand mold top surface temperature measuring device that measures infrared rays emitted from each part of the top surface at least in the transport direction; a low pass filter that removes high frequency components from a sand mold top surface temperature signal output from the sand mold top surface temperature measuring device; A sprue that extracts a high-temperature region by binarizing the temperature image of the top surface of the sand mold in the direction at a specific threshold temperature, and determines a position separated from at least one end of the high-temperature region by a specific distance in the conveying direction as the center position of the sprue. The present invention is characterized in that it includes a position determining means, and an extraction arm driving means for moving the drafting arm to an optimal extraction position in the conveying direction calculated from the center position of the sprue.

The specific threshold temperature may be a preset constant temperature, or may be a variable threshold temperature that is linked to changes in room temperature.

The specific distance may be a fixed distance set in advance, or
The distances may be equal from both ends of the high temperature region.

The sprue position determining means determines the position based on the sand mold top surface temperature signal output from the sand mold top surface temperature measuring device.

It is characterized by being equipped with a pre-low-pass filter that removes high frequency components.

As the sand mold upper surface temperature measuring device, a combination of a radiation thermometer or an infrared sensor that detects the temperature at one point on the upper surface of the sand mold, and a moving device that moves these sensors in the conveying direction with respect to the sand mold can be used.

Furthermore, an infrared linear imager that conveys an image in the transport direction across the sprue, or an infrared area imager that decoys the upper surface of the sand mold including the sprue can be used. When detecting a temperature image of the upper surface of the sand mold using an infrared linear imager or an infrared area imager, illumination of the upper surface of the sand mold with infrared rays having the same wavelength band should be prohibited.

[Operation] The conveyor device intermittently conveys the frameless sand mold rows. In a frameless sand mold row consisting of a plurality of sand molds connected in a row in the direction of travel, sprues are provided regularly (generally at regular intervals) on the top surface of the sand mold, and the sand mold top surface temperature measuring device measures the temperature on the top surface of the sand mold including the sprue gates. The temperature of each part is measured at least in the conveyance direction.The sprue position determination means binarizes the measured top surface temperature image of the sand mold at a specific threshold temperature, extracts a high temperature area, and sets a predetermined position of the high temperature area in the conveyance direction. It is determined as the center position of the sprue.

Since the sprue center position and the casting removal position are set in advance to be a certain distance apart, the casting removal position in the transport direction can be accurately estimated based on the determination of the sprue center position. As a result, based on the obtained information regarding the casting extraction position, the extraction arm driving means controls the extraction arm of the casting extraction device to reliably extract the casting regardless of fluctuations or variations in the extraction position in the conveyance direction.

In particular, in this invention, the sprue position determination means removes the high frequency component from the sand mold top surface temperature signal output from the sand mold top surface temperature measuring device, and processes the low frequency component of the extracted sand mold top surface temperature signal. Determine the sprue center position. Therefore, the high-frequency one-tone component included in the sand mold upper surface temperature signal is removed, and the sprue center position can be accurately determined.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

This frameless casting line includes a conveyor device 1, a casting extraction device 2, a sand mold upper surface temperature measuring device 3, a low-pass filter 6, an A/D converter 7, a sprue position determination means, and an extraction arm driving means. (See Fig. 1).

The conveyor device 1 consists of a conventional belt conveyor, the distal end of which is shown in FIGS. 1, 7 and 8. During interval operation, the conveyor device 1 removes the casting and detects the center position of the sprue. Then, the conveyor device 1 advances the frameless sand mold row 5 by a distance equal to the regular conveyance direction dimension LO of one sand mold 51 during one operation time. A frameless sand molding machine and a pouring machine (not shown) are installed on the upstream side of the conveyor device 1, and at the end of the conveyor device 1, about 50 m from the pouring machine is installed for cooling the poured metal.
A casting extraction device 2 and a sand mold upper surface temperature measuring device 3 are installed separately, and a sand grain collecting device @ 8 with a built-in sand recovery conveyor is installed at the end of the conveyor device 1. On the conveyor device 1, a frameless sand mold row 5 formed by connecting approximately 180 sand molds 51 in a row is placed. cavity 5
3 is formed, and a substantially rectangular sprue 54 communicating with the cavity 53 is provided on the upper surface of the boundary portion 52 (see FIG. 1). Also, a runner 55 leading from the sprue 54 to the cavity 53
A plan portion 56 extends in the horizontal direction perpendicular to the conveyance direction in the middle of the conveyance direction.
The molten metal poured from the sprue 54 is cooled and solidified, and a total of four cast iron castings (product parts) A are cast. A casting is formed. Therefore, in the following explanation, the sprue 5
4. The runner 55 and the plan part 56 refer to the castings therein. The regular dimension LO of each sand mold 51 in the conveyance direction is approximately 28 cm.
One side of the sprue 54 is initially formed to be about 8 cm, and the plan part 56 constitutes a part of the casting.

The casting extraction device 2 is movably supported by a rail 20 disposed above the end of the conveyor device 1, and has a structure in which it runs by itself on the rail 20 (see FIGS. 7 and 8). 〉.The tip of the rail 20 extends above the center in the left-right direction of the conveyor device 1, the center of the rail 20 curves upward in the figure in a horizontal plane, and the end of the rail 20 extends in the conveying direction. It forms a nearly right angle and is close to a hanger conveyor (not shown).A pair of extraction arms 22 and 23 are provided on the lower surface of the casting extraction device 2 and protrude downward.
These arms 22 and 23 face each other in the extending direction of the rail 20, and the relative distance is variable by a hydraulic cylinder (not shown) built into the casting extraction device 2. Also,
Two arms 22, 23 are arranged alternately (see Fig. 6), and projections on which the plan parts 56 are placed are formed at the tips of the arms 22, 23 in opposite directions. . Note that the current position of the casting extraction device 2 is constantly detected using an encoder (not shown) and is input to the microcomputer device 3. The casting device 2 delivers the used casting to a robot (not shown) in a fixed posture, and this robot hangs the received casting onto a hanger conveyor (not shown). Then, the casting extraction device 2 that has handed over the casting to the robot automatically moves back to its reference position x 2, and then is guided by the microcomputer device 4 to the optimal usage position.

The sand mold upper surface temperature measuring device 3 consists of a radiation thermometer section installed at the end of the conveyor system @1, and a moving device section that moves this radiation thermometer section back and forth in the conveying direction once every period of suspension of operation. The infrared rays emitted from the upper surface of the sand molds of the frameless sand mold array 51 are detected in the transport direction by being disposed facing downward above the center in the left-right direction of the device 1 . The moving device section is provided with a rotary encoder (not shown) that outputs the current position of the radiation thermometer section in the transport direction. Therefore, while moving, the sand mold upper surface temperature measuring device 3
1. The upper surface temperature and the current position in the conveying direction are stored in the microcomputer device 4.
Output to. The sand mold upper surface temperature measuring device 3 is arranged at a sensor reference position x 1 upstream from the reference position @ . The sensor is configured to move by 0.75 LO in the upstream direction and the downstream direction from the sensor reference position x1 in the - times of measurement. This is because the detection operation of the sprue center position m and the casting operation are performed in parallel while the conveyor device 1 is out of operation. Therefore, this sensor reference position ×
1 to the sprue center position is ΔX, it can be seen that the casting device 2 only needs to be moved by ΔX in the transport direction in the next casting extraction. In this case, the positional shift of the sand mold 51 during the movement of the sand mold 51 from below the sand mold upper surface temperature measuring device 3 to below the casting processing device 2 is ignored. As described above, the size of the sand mold upper surface temperature measuring device 3 in the conveyance direction that allows image transfer is set larger than the conveyance direction dimension LO of the sand mold 51, so that at least one sprue 54 can be completely imaged. ing. According to actual measurements, the temperature of the upper surface of the sand mold 51 is 200°C or less, and the temperature of the sprue 54 is about 500'C. The thickness is set to about .8 μm, and more preferably about 2 μm to 1 μm. In such a wavelength band, the energy of the infrared rays generated from the sand is minute, which is advantageous for separating the sand from the sprue.

The results of actual measurements of the temperature on the top surface of the sand mold are shown below.

Gate center position: 391°C to 567°C, average 494°C Sand surface near gate: 78°C to 173°C, average 130°C Sand surface between gates: 77°C to 149°C, average 114°C The above-mentioned variations in temperature are due to the elapsed time since the start of the line, fluctuations in temperature, fluctuations in various line speeds, and the like.

The low-pass filter 6 blocks the high-frequency component of the signal voltage (sand mold top-surface temperature signal) output from the sand mold top surface temperature measuring device 3, and transmits only the low-frequency component VL to the A/D converter 7.
send to This high frequency component contains many noise voltages caused by variations in infrared radiation intensity due to roughness of the sand surface, variations in infrared absorption due to water vapor emitted from the sand mold, sand covering of the sprue, etc. Therefore, the cutoff frequency of the low-pass filter 6 is set to a value that cuts off high-frequency noise components due to these causes. A/D converter 7
A/D converts the low frequency component VL and inputs it to the microcomputer device 4 as a digital sand mold top surface temperature signal vdd.

The microcomputer device 4 calculates the center position m of the sprue (see FIG. 10) by processing the digital sand mold top surface temperature signal Vdd, and calculates the position of the casting plan part 56 (
It has a function of determining the casting extraction position (extraction position) and moving the casting extraction device 2 above this handling position. Then, the microcomputer device 4 lowers the casting extraction device 2 and sticks the pair of extraction arms 22, 23 into both sides of the drafting part 56 in the conveyance direction (see FIG. 2), and then moves the extraction arms 22, 23 close to each other. direction (see Fig. 3), and
to grasp. Next, after pulling up the casting extraction device 2 (
4), along the rail 20, and hooked onto a hanger on a hanger conveyor (not shown) by a robot (not shown).

The detailed operation of the microcomputer device 4 is shown in FIGS. 9 and 10 below.
This will be explained with reference to the signal waveform diagram shown in FIG. 1 and the flowchart shown in FIG.

First, initial settings are made in S10, and the system waits until the conveyor start signal S1 is input (S12>. Conveyor start signal S
1 and the conveyor stop signal S2 are input to the microcomputer device 4 from a central control device (not shown) that controls the conveyor device 1. When the conveyor start signal S1 is input, after ε seconds have elapsed (S14), if the conveyor stop signal S2 is input before 10 seconds have elapsed (316), the process advances to S20, and a state where the conveyor stop signal S2 is not input. When 10 seconds have passed (S16), the conveyor start signal S1 input in 312
It is determined that this is not a normal signal and the process returns to S12.

By implementing steps 312 to S16, it is possible to prevent the casting extraction device 2 from operating due to an abnormal conveyor activation signal S1 other than during normal interval operation.

When the conveyor stop signal @S2 is input (S18), the digital sand mold top surface temperature signal Vdd is received from the sand mold top surface temperature signal device @3 via the comparator 6 and the A/D converter 7 (S20>, and the received digital sand mold top surface temperature signal V
dd is processed to neutralize the intermediate position in the transport direction of the sprue 54, that is, the sprue center position m, and the transport direction coordinates 1 and L2 of this sprue center position m are determined (see FIG. 10). However, the transport direction coordinates 1 and L2 indicate the distance from the sensor reference position x1. Note that this sprue center position calculation subroutine is executed as follows. That is, the input digital sand mold top surface temperature signal Vdd is binarized using a preset threshold voltage Vt to obtain a binarized signal Vd, and the high temperature region Sm corresponding to the level 1 region of the binarized signal Vd is The midpoint between the rising edge and the falling edge is determined as the sprue center position m. Note that in this example, the threshold voltage yt corresponds to the threshold temperature Tt (300° C.).

In FIG. 1, two sprue center positions m are detected by one imaging, but if the sprue center position m is located near the sensor reference position X1 (the center of the image carrying area), 1
One sprue center position m is detected by imaging twice. However, when detecting two sprue center positions m using one eye image, the sprue center position m on the downstream side in the transport direction is the sprue center position m to be detected this time. If one end of the high-temperature region Sm (see Figure 10) hangs over either end of the image transport region, the center position of this high-temperature region Sm cannot be detected accurately; (Il
The center position m of the high temperature area (gate area>Sm) on the upstream side in the feeding direction is determined.

Next, the difference (L2-
xl) in the transport direction (
S24). This is because the casting extraction device 2 is located downstream by two sand molds 51. When reaching this target position (326), the casting extraction device 2 performs the above-mentioned casting extraction (S28).

As explained above, the frameless casting line of this embodiment is
As a sprue position determination means, the center position of the high temperature region 3 m exceeding a preset threshold temperature Tt is determined as the sprue center @ m
For example, the sprue 54
Determining the sprue position is easier and more accurate than when determining the front end or short end of the sprue and recognizing it as the sprue position.

In addition to the method described above, a method of determining the highest temperature point may be used to determine the sprue center position m. However, when considering variations in temperature on the surface of the sprue 54 due to sand cover, etc., the most advantageous method is to find the center point of the high temperature region Sm above the threshold temperature Tt.

Furthermore, as the above-mentioned sand mold upper surface temperature measuring device 3, a radiation type temperature sensor that reciprocates in the conveying direction to detect the temperature of each part of the upper surface of the sand mold may be used.

In the above embodiment, the arm is extracted from the top down and the arm is pierced, but it is also possible to pierce the arm from the side and extract it upward as a modified form.

Furthermore, according to this embodiment, before the sand mold upper surface temperature signal V outputted from the sand mold upper surface temperature signal device M3 is binarized using the threshold voltage yt and the high temperature region Sm is extracted, the sand mold upper surface each part signal @V is Since the included high-frequency noise components are removed, both ends of the high temperature region Sm can be accurately determined, and as a result, the sprue center position @m can be accurately determined.

To explain further, the boundary between the sprue 54 and the upper surface of the sand mold 51 is almost the end of the high temperature region Sm, but accurate detection of this boundary is not so easy. That is, as shown in FIGS. 12 and 13, casting grains may be scattered on the upper surface of the sand mold 51 near this boundary due to lifting weight, and the sprue surface near this boundary may be covered with sand. There is. As a result, the sand mold upper surface temperature signal V has a small high temperature region vm due to the uplift and a small low temperature region VV due to sand covering, and the intersection point between the boundary and the threshold voltage Vt changes.

In this embodiment, these small high temperature regions Vm and small low temperature regions V
Focusing on the fact that V has a high frequency band, we cut them off with a low-pass filter, so we can accurately measure high-temperature regions [
It becomes possible to distinguish 3m.

[Effects of the Invention] As explained above, the frameless casting line of the present invention is provided with a sand mold upper surface la image device or a sand mold upper surface temperature measuring device at the end of the conveyor device and upstream of the mold extraction device, so that individual Since the sprue position is detected, the casting removal position is determined from the detected sprue position, and the handling device is aligned, the casting is handled, so that the following effects can be achieved.

(1) It is possible to accurately estimate the casting extraction position,
As a result, it becomes possible to reliably extract the casting regardless of fluctuations or variations in the position of the casting. Further, since the posture of the extracted casting is always constant and the casting can be gripped or placed with a fixed portion of the extraction arm, subsequent handling work is simplified and automation thereof is facilitated. Further, in the present invention, since the casting extraction position is determined from the sprue position that is integrated with the casting, it is possible to reliably determine the invisible casting extraction position.

(2) According to the present invention, since the casting extraction device is accurately guided and guided to the cutting part of the casting, it is possible to grasp the plan part formed integrally with the sprue, and it is possible to grasp the casting part and the like, unlike the conventional casting product. There is no need to hold the part vertically and there is no chance of damaging it.

Further, when changing the shape of a cast product part, there is no need to take the above-mentioned grip into consideration.

(3) In addition to placing the casting extraction device at the end of the conveyor device and discharging the castings horizontally in the conveying direction as in the past, it is also possible to extract the castings to the left and right or above the conveyor device. As a result, the degree of freedom in arranging the casting extraction device increases. This is possible because the position of the casting in the transport direction, which tends to fluctuate, can be accurately determined.

In particular, in the frameless casting line of the present invention, the sprue position determination means extracts the sprue position after removing the high frequency component from the sand mold top surface temperature signal output from the sand mold top surface temperature measuring device. Furthermore, the following effects can be achieved.

(4) Before binarizing the sand mold top surface temperature signal output from the sand mold top surface temperature measuring device at a specific threshold temperature and extracting the high temperature region, high-frequency noise components included in the sand mold top surface temperature image are removed. Therefore, both ends of the high-temperature region can be accurately determined, and as a result, the center position of the sprue can be accurately determined despite dripping and sand covering near the boundary between the sprue and the top surface of the sand mold.

[Brief explanation of the drawing]

FIGS. 1 to 4 are block diagrams sequentially showing the casting extraction operation in an embodiment of the frameless casting line of the present invention, and FIG.
The figure is a schematic perspective view showing an example of a sand mold abnormality in a row of frameless sand molds, FIG. 6 is a plan view of casting A in FIG. 1, FIG. 7 is a plan view of the end of the conveyor device 1, and FIG. A side view of the end of the device 1, FIG. 9 is a temperature distribution diagram on the top surface of the sand mold of the frameless sand mold row 5 at the end of the conveyor device 1, FIG. 10 is a signal waveform diagram showing signal waveforms of each part, and FIG. 11 is a microcontroller 5 is a flowchart of the device 4. FIG. 12 is an enlarged sectional view of the vicinity of the sprue 54, and FIG. 13 is a waveform diagram of the sand mold upper surface temperature signal V in the vicinity of the sprue 54. 1... Conveyor device 2... Casting extraction device 3... Sand mold upper surface temperature measuring device 4... Microcomputer device (gate position determination means) (Extraction arm driving means) 6... Low pass filter taste powder

Claims (1)

[Claims] (1) A conveyor device that intermittently conveys a frameless sand mold row consisting of a plurality of sand molds connected in a line in the traveling direction and each having a sprue, and a conveyor device that is disposed at the end of the conveyor device and extracts castings from the sand mold. a sand mold upper surface temperature that is disposed close to the upstream side of the casting extraction device in the conveyance direction and that measures infrared rays emitted from various parts of the upper surface of the sand mold, including the sprue, at least in the conveyance direction; a measuring device; a low-pass filter that removes high-frequency components from the sand mold top surface temperature signal output from the sand mold top surface temperature measuring device; a sprue position determination means for extracting a high-temperature region using the high-temperature region, and determining a position separated from at least one end of the high-temperature region by a specific distance in the conveyance direction as the center position of the sprue; and an optimal conveyance direction calculated from the sprue center position. A frameless casting line characterized in that it is equipped with an extraction arm driving means for moving the extraction arm to an extraction position.