JPH03155452A - Flaskless type casting line - Google Patents

Abstract

PURPOSE:To make sure of taking-out work by molding with positional relation of a sprue and casting design part in each sand mold having different cavity specified to the same, picking up image of the sand mold surface, deciding the position of sprue, shifting taking-out arms to the optimum position and taking out a casting. CONSTITUTION:A sand mold upper face temp. measuring instrument 3 measures the surface temp. of flaskless sand mold 51, and a micro-computing unit 4 calculates center position of the sprue 54 and indicates so that a pulling-out device 2 shifts to the optimum pulling-out position on rails 20. When the pulling- out device 2 reaches the prescribed position, the arms 22, 23 are worked to hold the casting design part 56 in the casting A and after pulling up, this is shifted along the rails 20 to take out the casting A. The sand is conveyed with a conveyor 1 and sent to a recovery device. 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 hall 1. A pouring machine, a casting removal device, a sand collecting machine, etc. are arranged, but the working environment is not good from a thermal and dust standpoint, so 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 You can see the suppression arm being pierced by the sand mold above. When taking out the casting, after sticking the platform arm into the hole, 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 photographic sieve, the posture and position of the casting to be taken out are uncertain;
The subsequent handling 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 poor conditions.

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. Moreover, 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 removal 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 an extracted casting on a casting conveyor, it is difficult to place the casting unless the casting is always gripped at a certain position (generally the tip) of the extraction arm. Furthermore, there are cases where the casting in the sand mold is incompletely caught by the extraction arm, and in this case too, the casting fails to be extracted.

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 extraction or damage to the casting by the scooping 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 pull it out of the sand mold, so there is a possibility that the casting 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 sand mold making device that is disposed at the starting end of the device and that molds the same positional relationship between the sprue and the extraction portion of each sand mold having different cavities; A casting extraction device comprising an extraction arm that engages with a return position of a drafting part to remove 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 conveyance direction and includes a sprue. a sand mold top surface imaging device that captures a pupil image of the top surface; a sprue position determination means that determines the position of the sprue in the conveyance direction from the imaged sand mold top surface image; The invention is characterized by comprising an extraction arm driving means for moving the extraction arm.

As the sand mold top surface imaging device, a linear imager that images the sand mold in the transport direction across the sprue, or an area imager that images the sand mold top surface including the sprue can be used. It is also possible to combine an optical sensor that images a point on the top surface of the sand mold with a moving device that moves the sensor in the transport direction with respect to the sand mold. Since each of these image or light sensors detects visible light or infrared light, the upper surface of the sand mold is illuminated by an illumination device.

Further, as the sand mold top surface imaging device, a sand mold top surface temperature measuring device that measures the temperature of each part of the top surface of the sand mold in a non-contact manner can be employed. As this sand mold upper surface temperature measuring device, it is possible to use 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 transport direction relative to the sand mold. Furthermore, an infrared linear imager that captures an image in the transport direction across the sprue, or an infrared area imager that captures an R image of 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. Note that the cavity here means a cavity for casting a product part of the casting.

[Operation] The conveyor device intermittently conveys the frameless sand mold rows. Sprues are provided regularly (generally at regular intervals) on the top surface of the sand molds of a frameless sand mold row consisting of a plurality of sand molds connected in a row in the traveling direction, and the sand mold top surface imaging device captures the top surface of the sand mold including the sprues. Take an image. The sprue position determining means processes the imaged top surface image of the sand mold to determine the position of the sprue in the transport direction. Since the sprue position and the casting extraction position are set in advance to be a certain distance apart, the casting extraction position in the transport direction can be accurately estimated based on the determination of the sprue position. Based on the information regarding the extraction position of the casting, the centering arm driving means controls the double extraction arm of the casting extraction device to change the extraction position in the conveying direction.
To reliably extract castings regardless of variations.

Particularly, in the present invention, the sand mold making apparatus molds sand molds having different cavities with the same relative positional relationship between the sprue and the extracted portion of the plan part. Therefore, even if the shape of the product part of the casting is different, the casting extraction device can accurately grasp or place the cutting part of the plan part at the tapping position determined by detecting the sprue position, and dump the casting. put out.

[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 sand mold making device 9, a casting extraction device 2, a sand mold upper surface temperature measuring device 3, a low pass filter 6, an A/D converter 7,
It consists of a microcomputer device 4 which also serves as sprue position determining means and duplicating 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. The conveyor device 1 is operated in intervals, with the operation time set to 2.2 seconds and the operation stop period set to 8 seconds.
During this period of suspension of operation, the casting is removed and the center position of the sprue is detected. 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. On the upstream side of the conveyor device 1, there is a sand mold making device 9 and a pouring machine (
(not shown) is provided at the end of the conveyor device 1.
A casting extraction device 2 and a sand mold upper surface temperature measuring device 3 are installed approximately 50 m away from the pouring machine to cool the poured metal, and a sand recovery device 8 with a built-in sand recovery conveyor is installed at the end of the conveyor system @1. It is set up. Approximately 20
A frameless sand mold row 5 formed by connecting 0 sand molds 51 in a row is placed, and a cavity 53 for a cast product is formed at the boundary 52 between two adjacent sand molds 51. A substantially rectangular sprue 54 communicating with the sprue 53 is provided on the upper surface of the boundary portion 52 (see FIG. 1). In addition, a plan part 56 extending in the horizontal direction perpendicular to the conveying direction is formed in the middle of the runner 55 from the sprue 54 to the cavity 53, and the molten metal poured from the sprue 54 is cooled and solidified to form a total of 4 molten metal.
Each cast iron casting (product part) A is cast, and castings are also formed in the sprue 54, runner 55, and plan part 56. Therefore, in the following explanation, the sprue 54, the runner 55
and the design part 56 means the casting therein. Each sand mold 51
The normal dimension Lo in the conveyance direction is approximately 280 m, and each side of 1054 is initially formed to be approximately 8 cm, and the plan portion 56 constitutes an extracted portion of the casting.

The sand molding device 9 is arranged at the starting end of the conveyor device 1. This sand mold making device 9 is a device that molds sand molds 51 on the conveyor device 1 during a period when the conveyor device 1 is stopped, and then presses the molded sand molds 51 one after another against the end of the frameless sand mold row 5. Since the details are well known, the explanation will be omitted.

However, the important point is that this sand molding device 9
Despite the change in the shape of No. 3, from the sprue 54 to the plan portion 5.
The shape of the cavity portion up to No. 6 remains unchanged at all times.

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 is curved upward in the figure in a horizontal plane, and the end of the rail 20 is approximately perpendicular to the conveyance direction. It is located 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 project 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 drawing device 2 delivers the drawn casting in a constant posture to a robot (not shown), and this robot hangs the received casting onto a hanger conveyor (not shown). Then, the casting extraction device @ 2 that 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 optimum extraction position.

The sand mold upper surface temperature measuring device 3 consists of a radiation thermometer section provided at the end of the conveyor device 1, and a moving device section that moves the radiation thermometer section back and forth in the conveying direction once every outage period. 1, and detects infrared rays emitted from the upper surface of the sand molds of the frameless sand mold row 51 in the transport direction. 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 disposed at a sensor reference position x1 upstream from the reference position x2 of the casting drawing device 2 by a distance equal to the conveying direction dimension (2Lo) of the two sand molds. The sensor is configured to move by 0.75 Lo in the upstream direction and the downstream direction with respect to the sensor reference position x 1 as the center during the - times of measurement. This is because the operation of detecting the sprue center position m and the operation of pulling out the casting are performed in parallel during the period when 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 in the next casting extraction, it is sufficient to move the casting drawing device 2 by ΔX in the conveying direction. In this case, the positional shift of the sand mold 51 while the sand mold 51 moves from the top of the sand mold upper surface temperature measuring device 3 to the bottom of the casting pulling device 2 is ignored. As described above, the imageable size of the sand mold upper surface temperature measuring device 3 in the conveyance direction is set larger than the conveyance direction dimension LO of the sand mold 51, and at least one sprue 54 can be completely imaged. There is. Note that, 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 s μm, 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 the temperature of each part are due to the elapsed time since the start of the line, fluctuations in temperature, fluctuations in various line speeds, etc.

The low-pass filter 6 cuts off the high frequency component of the output signal voltage (sand mold top surface temperature signal) (2) from the sand mold top surface temperature measuring device 3 and sends only the low frequency component VL to the A/D converter 7. The A/D converter 7 converts the low frequency component VL into an A/D converter.
It is converted and inputted 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 upper surface temperature signal dd, and determines the position of the casting design part 56 (
It has a function of determining the double ejecting position) and moving the casting extractor 2 above this ejecting position. Then, the microcomputer device 4 lowers the casting extraction device 2, thrusts the pair of extraction arms 22, 23 into both sides of the drafting part 56 in the conveying direction (see FIG. 2), and then moves the extraction arms 22, 23 close to each other. Move in the direction (see Figure 3), planning section 56
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 using the SIO, 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 bag @ (not shown) that controls the conveyor device 1. When the conveyor start signal S1 is input, after 4 seconds have passed (S14), if the conveyor stop signal S2 is input before 10 seconds (316>), the process advances to 320, and when the conveyor stop signal S2 is not input, the process goes to 320. After seconds have passed (
316), 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 (318), the digital sand mold top surface temperature signal Vdd is received from the sand mold top surface temperature measuring device 3 via the comparator 6 and the A/D converter 7 (S20>, and the received digital sand mold top surface temperature signal ■ d
d is processed to calculate an intermediate position in the conveying direction of the sprue 54, that is, a sprue center position m, and the conveying direction coordinates 1 and L2 of this sprue center position m are determined (see FIG. 10). however,
The transport direction coordinate positions L1 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 upper surface temperature signal Vdd is converted to 21a with a preset threshold voltage Vt to obtain a binary signal Vd, and the rise of the high temperature region Sm corresponding to the level 1 region of the binary signal Vd is The midpoint between the edge and the falling edge is determined as the sprue center position m. In this example, the threshold voltage yt corresponds to the threshold temperature Tt (300° C.). In addition, in Fig. 1, two sprue centers are captured by one imaging.
However, if the sprue center position m is located near the sensor reference position x 1 (in the center of the imaging area), one sprue center position m is detected by one imaging. However, when detecting two sprue center positions m by one imaging, the sprue center position m on the downstream side in the transport direction is the sprue center position m to be detected this time. And high temperature area S
If one end of m (see Figure 10) hangs over either end of the l1ffl image area, the center position of this high-temperature area Sm cannot be detected accurately; The center position m of the high temperature area (gate area) Sm on the side) 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 this target position is reached (S26>, the casting extraction device 2 performs the above-mentioned casting removal (828>).

As explained above, the frameless casting line of this embodiment is
As a sprue position determination means, the center position of a high temperature region Sm exceeding a preset threshold temperature Tt is determined as a sprue center position m.
For example, the sprue 54
Determining the sprue position is easier and more accurate than determining the front end or rear end of the sprue and setting 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, in this embodiment, the sand mold making device 9
Even if the shape of the sprue 3 is changed, the shape and relative positional relationship of the sprue 54 and the plan part 56 remain unchanged, making it convenient for manufacturing various casting products.

[Effects of the Invention] As explained above, the frameless casting line of the present invention detects the position of each sprue by providing a sand mold upper surface image device at the end of the conveyor device and upstream of the mold extraction device. Since the casting extraction position is determined from the detected sprue position and the casting is extracted upward by the extraction device, 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 center the casting regardless of fluctuations or variations in the position of the casting. In addition, the posture of the extracted casting is always constant, and the exposed part of the casting can be grasped or placed with a fixed part of the extraction arm, making subsequent handling operations easier and automation easier. Become.

Furthermore, in the present invention, since the casting extraction position (the position of the extraction part of the plan part) 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 to the extraction part of the plan part, there is no need to hold the casting product part vertically as in the past, and there is no possibility of damaging it. do not have. Furthermore, since the design part can be formed directly below the sprue, the depth of piercing can be reduced when the arm is extracted from above.

(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 side of the conveyor device or to the top. 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, since the sand molding device molds the sprue and the extracted portion of the draft part in the same relative positional relationship, the following effects can be further achieved.

(4) Castings of various shapes can be reliably extracted from various sand molds having different cavity shapes with the same operation.

Furthermore, in order to reliably extract castings of various shapes from the sand molds in a frameless casting line for multi-product casting, and to handle them reliably after extraction, the position of the extraction part of the plan section (especially the position in the conveyance direction) must be adjusted. ) is required to be detected accurately before pouring out. To do this, the relative positional relationship between the sprue and the extracted part of the plan part is always kept constant, the sprue position is detected, and the position of the sprue is detected from the detected sprue position. The simplest and most accurate method is to determine the position of the extracted portion of the plan section.

[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 an abnormality in the sand mold being applied to the frameless sand mold row, FIG. 6 is a plan view of the casting A shown in FIG. 1, FIG. Figure 8 shows conveyor device 1
9 is a temperature distribution diagram on the upper 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 at each part, and a flow chart of the first conveyor device 4 It is. 1... Conveyor device 2... Casting extraction device 3... Sand mold top surface temperature measuring device (sand mold top surface imaging device) 4... Microcomputer device (gate position determination means) (Extracting arm drive means) Figure 1 shows the microcomputer device

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 disposed at the starting end of the conveyor device and having mutually different cavities. a sand mold making device that creates the same positional relationship between the sprue of each sand mold and the extracted portion of the pattern portion; A casting extraction device equipped with an extraction arm for extracting a casting; a sand mold top surface imaging device disposed close to the upstream side of the casting extraction device in the conveying direction and capturing an image of the top surface of the sand mold including the sprue; and the imaged top surface of the sand mold. A sprue position determination means for determining the position of the sprue in the conveyance direction from an image, and an extraction arm driving means for moving the extraction arm to an optimal extraction position in the conveyance direction calculated from the sprue position. Frameless casting line.