JPH04319067A - Flaskless type casting line - Google Patents

Abstract

PURPOSE:To provide the line, in which molten metal can be exactly poured into the prescribed number of sprue to be poured in spite of variance of the sprue position. CONSTITUTION:An intermittent conveying device 3 intermittently conveys the flaskless sand mold line 200. TV cameras 4a, 4b (image pickup means) take image of boundary zone 300 between the adjoining sand molds at the prescribed number in the conveying sand mold line 200, and an arithmetic part 5 (boundary line decision means, sand mold width decision means and molten metal pouring position decision means) decides the boundary line at between the adjoining sand molds 100 by treating the image signal and decides the sand mold width in conveying direction from the width in conveying direction of the boundary line to two adjoining molds in the conveying direction and decides the present position in the conveying direction of the sprue 400 at the prescribed number from upstream end in the sand mold line as the molten metal pouring position based on the decided each sand mold width and these decided informations are outputted to a molten metal pouring machine, and the molten metal pouring machine executes the pouring of molten metal after shifting a pouring cylinder just above the sprue in the molten metal pouring position.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frameless casting line.

0002

[Prior Art] In a conventional frameless casting line, a sand mold making machine, a sand mold extruder, a pouring machine, a casting removal device, a sand recovery machine, etc. are arranged along an intermittent conveying device for conveying sand molds that is operated at intervals. has been done. The sand mold row on the intermittent conveying device is made up of frameless sand molds connected in a row, and a sprue that communicates with the internal cavity is opened at the center of the upper surface of the boundary between adjacent sand molds. Molten metal is sequentially poured into the second sprue from a pouring machine.

[0003] In this pouring process, it is natural that alignment between the pouring barrel and sprue of the pouring machine is very important, and Japanese Patent Application Laid-open No. 1150/1983 describes the piston of the press in the sand molding machine. The width of the sand mold is detected by the stroke, and the position of the sprue in the transport direction near the pouring machine is detected by the sum of the predetermined number of continuously detected piston strokes. The tip of the pouring tube is moved to align the pouring tube and sprue.

0004

[Problems to be Solved by the Invention] However, in the prior art, the piston stroke of the sand mold making machine described above is regarded as the sand mold width, and a predetermined sprue position is detected by the sum of the piston strokes.
There were the following problems. That is, the sand mold produced by the sand mold making machine is pressed against the end of the sand mold row by the sand mold extruder, but at this time, the sand mold shrinks and the width of each sand mold varies, and the sum thereof varies.

Second, in the apparatus disclosed in the above-mentioned publication, after the latest sand mold row is pressed against the end by the piston of the press of the sand mold making machine, this sand mold row is pushed out in the conveying direction, but there is an intermittency in the conveyance of the sand mold row. When using a conveyance device, there are variations in the conveyance distance each time with the intermittent conveyance device, so the width of N (N is plural) sand molds from the end of the sand mold row is calculated for each time of conveyance with the intermittent conveyance device. However, since the end position of the sand mold row could not be confirmed, the position of the sprue where the metal should be poured could not be determined.

The present invention has been made in view of the above problems, and provides a frameless casting method that allows pouring metal accurately into the sprue of a predetermined number of pouring points despite the above-mentioned variations in sprue position. Its purpose is to provide a line.

[0007]

[Means for Solving the Problems] The frameless casting line of the present invention includes a molding machine that molds sand molds, and an extruder that extrudes the molded sand molds in one direction to form rows of sand molds that are closely aligned with each other. , an intermittent conveying device for intermittently conveying the sand mold array in the sand mold array direction, and a pouring cylinder movable in the sand mold array direction to pour the melt into sprues opened at regular intervals on the upper surface of the sand mold array, from the extruder to the sand mold array. In a frameless casting line equipped with a pouring machine disposed at a predetermined distance in the sand mold arrangement direction, an imaging means for imaging a boundary area between adjacent sand molds in a row of sand molds being conveyed and outputting a video signal. a boundary line determining means for determining a boundary line by processing the video signal corresponding to the boundary area; and determining a sand mold width in the conveying direction from widths in the conveying direction of two boundary lines adjacent in the conveying direction. sand mold width determining means;
It is characterized by comprising pouring position determining means for determining the current position in the transport direction of the sprue at a predetermined point from the upstream end of the sand mold row as the pouring position based on the determined width of each sand mold, and outputting the determined pouring position to the pouring machine. It is said that

[0008]

[Operation] In the frameless casting line of the present invention, the intermittent conveying device intermittently conveys the frameless sand mold rows. The imaging means images the boundary area between adjacent sand molds of a predetermined number in the row of sand molds being conveyed, and the boundary line determining means processes the video signal to determine the boundary line between the adjacent sand molds. The sand mold width determining means determines the sand mold width in the transport direction from the width in the transport direction of two boundary lines adjacent in the transport direction, and the pouring position determining means determines the sand mold width upstream of the sand mold row based on the determined width of each sand mold. The current position in the transport direction of the sprue at a predetermined point from the end is determined as the pouring position and output to the pouring machine.The pouring machine moves the pouring cylinder directly above the sprue at the pouring position, and then starts pouring. implement.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1 and FIG. 2, which is a partially enlarged view of the most upstream part, this frameless casting line includes a sand mold making machine 1 that molds a sand mold, and a sand mold 100 that extrudes the molded sand mold 100 in one direction. An extruder (ejector) 2 that forms sand mold rows 200 in close contact with each other, an intermittent conveyance device 3 that intermittently transports the sand mold rows 200 in the arrangement direction, and a transfer between adjacent sand molds 100, 100 in the sand mold row 200 being transported. boundary area 3
TV cameras (imaging means in the present invention) 4a and 5b that take an image of 00 and output a video signal, and a calculation unit 5 that determines the sprue position based on the sand mold width calculated by processing the imaging means in the video signal. and a pouring machine 7 that pours metal into the sprue at the pouring position output from the calculation section 5.

As shown in FIG. 3, the sand molding machine 1 is disposed close to the end of the intermittent conveying device 3, and includes a hopper 11 above, presses 12 and 13 below the hopper 11, and presses 12 and 13 directly below the hopper 11. It consists of 14 elevators. The extruder 2 is provided below the press 13, and extrudes the molded sand mold forward in the conveying direction, so that the sand mold rows on the intermittent conveying device 3 are
This is a hydraulic drive device that presses against the end of the 00.

[0011] The intermittent conveyance device 3 is a so-called walking beam type conveyance device, and is operated in intervals, with an operating time of 2.2 seconds and a non-operational engine set to 8.8 seconds. Pouring metal and removing castings inside. On the intermittent conveyance device 1, there is a frameless sand mold row 200 formed by connecting approximately 200 sand molds 100 in a row.
is placed, and a cavity (not shown) for a cast product is provided at the boundary 300 between two adjacent sand molds 100.
A substantially rectangular sprue 40 is formed and communicates with each cavity.
0 is provided on the upper surface of the boundary portion 300 (see FIG. 1).
. The standard dimension of one sand mold 100 in the transport direction is, for example, approximately 4
0 cm, and the intermittent conveying device 3 advances the frameless sand mold row 200 by a distance equal to this dimension each time.

The TV cameras 4a and 5a have a built-in CCD area sensor, and are disposed on the side of the upstream portion of the intermittent conveyance device to image the boundary area 300 and send video signals via comparators 51 and 52. and sends it to the calculation section 5. The calculation unit 5 includes a microcomputer device 5 for image processing, and determines the sprue position based on the sand mold width calculated by processing the video signal. The calculation unit 5 also serves as a boundary line determining means, a sand mold width determining means, and a pouring position determining means in the present invention.

The pouring machine 7 is disposed a predetermined distance from the extruder in the sand mold arrangement direction. Further, the pouring machine 7 has a pouring cylinder 71 that is movable in the sand mold arrangement direction to pour the metal into sprues 400 that are opened at regular intervals on the upper surface of the sand mold row 3. The operation of the present invention will be explained with reference to FIGS. 3 to 8. First, the sand mold making machine 1 creates a sand mold.

That is, after performing a predetermined operation preparation operation (see FIG. 3), the frame 15 on which the elevator 14 is placed
Sand is dropped from the hopper 11 (see Figure 4). At this time, the front and rear of the frame 15 are surrounded by covers (not shown) to prevent sand from escaping from the front and rear of the frame 15. Next, press 12 inside this cover.
, 13 compress the sand inside the frame 15, and due to this compression, the front mold 16 and the rear mold 17 provided at the piston tips of the presses 12 and 13 form half cavities on the front and rear surfaces of the sand mold 101 (Fig. 5 reference). Next, presses 12 and 13
moves back and forth, and the elevator 14 lowers the frame 15 and the sand mold 101 inside it (see FIG. 6).

Next, the extruder 2 pushes the sand mold 101 forward to separate the sand mold 101 from the frame 15, and then,
A sand mold 101 is pressed against the rear surface of the sand mold 100 at the end of the sand mold row 100. Note that during this pressing, the extruder 2 detects a gap between the rear surface of the sand mold 100 and the front surface of the sand mold 101 using a photo-interrupter type optical sensor (not shown), and detects when this gap disappears. The extruder 2 is stopped after a slight delay from the start (see FIG. 7).

After that, as will be described later, the TV camera 4a,
The video signal captured by 4b is processed by the calculation unit 5 to calculate the pouring position, and then the pouring machine 7 is moved to align the tip of the pouring cylinder 71 directly above the calculated pouring position. Pour the hot water into the sprue at the specified number. Next, the extruder 2 is moved backward, the core is placed in the rear half-cavity, the elevator 14 is raised, and the intermittent conveyance device 3 is conveyed once (see FIG. 8).

Next, the operation of the calculation section 5 will be explained with reference to the flowchart shown in FIG. First, initial settings are made in S1, and the extruder 2 advances the latest sand mold and waits until it comes into contact with the end of the sand mold row and stops (S2). Next, one frame of video signals from each of the TV cameras 4a and 4b is output to the calculation section 5. Here, the TV camera 4a images the boundary area between the sand molds 100 and 101, and the TV camera 4b images the boundary between the sand mold 101 and the tip surface of the piston of the extruder 2 (S3
).

Next, the binary image signal of the TV camera 4a is processed by the two-dimensional image processing subroutine, and the sand mold 100 is
, 101 is determined (S4). Next, the distance L (see FIG. 10) between the determined boundary line 300 and the piston tip surface C (see FIG. 2) of the extruder 2 is determined (S5). Note that the standard distance L between the center points m1 and m2 (see Fig. 10) of the imaging screens of both TV cameras 4a and 4b is
Since o is fixed and known, the center point m1 and the boundary line 30
0 and the transport direction distance ΔL2 is determined, and L=Lo+Δ
Calculate the sand mold width from the formula L1+ΔL2.

Next, the width of each of the 10 sand molds from the end of the sand mold 100 is added to determine the position of the boundary line k between the 10th and 11th sand mold from the end of the sand mold row 100 (ie (Pouring position) is determined (S6). That is, if the sum of the widths of the 10 sand molds is A, the current position of the piston tip surface C currently being imaged by the TV camera 4b = center point m2
The position displaced by the distance A from +ΔL2 toward the downstream side in the conveyance direction is the position of the boundary line k.

Next, the position of the boundary line k is output to the pouring machine 7, and the pouring machine 7 calculates the difference between the current position of the tip of the pouring cylinder 71 in the transport direction and the position of the boundary line k. After moving by that difference, pour the molten metal into the sprue where it should be poured. In the above embodiment, one boundary line was the tip end surface of the piston of the extruder 2 (at the time when it stopped after moving forward), but of course, the boundary line
The boundary line between the N-th (N is an integer) sand mold of 00 and the N+1-th sand mold may be detected, and the distance between the two may be determined.

Next, the method of determining the boundary line 300 by the boundary line determination subroutine (S4) will be explained with reference to FIGS. 11 to 13.
Further explanation will be given based on. The binary video signal sent to the arithmetic unit 5 via the converter 51 is as shown in FIG. That is, since the boundary area 600 is recessed, the threshold value of the comparator 51 and the illumination adjustment result in a black level, and the surfaces of the sand molds 100 and 101 have a white level (see FIG. 12).

First, two edges 700 and 800 are extracted (S20). next. The average position x1m of the edge 700 in the horizontal direction of the screen and the average position x2m of the edge 800 in the horizontal direction of the screen are determined (S21
). This can be done by finding the position x2 of the edge 700 in the horizontal direction of the screen for each horizontal scanning line, calculating the average of each x1, and calculating the average of each x2.

Next, the obtained average position x1m and average position x
2m in the conveyance direction (horizontal direction of the screen) is determined as the boundary line position (S22). In this way, even if some error occurs in the edges 700 and 800, the influence of the error can be reduced by averaging. Note that, as shown in FIG. 14, after S21, x obtained for each horizontal scanning line
Check whether the distance between 1 and x2 is within a predetermined range (S31), and if it is, proceed to S22; if not, omit x1 and x2 of the horizontal scanning line and calculate the average value. It is also preferable not to use it for calculation (S32). In this way, erroneous detection due to landslides can be prevented.

[0024]

Effects of the Invention As explained above, the frameless casting line of the present invention images the boundary area between adjacent sand molds in a row of sand molds being conveyed, processes the image signal, and processes the image signal between adjacent sand molds. The sand mold length in the transport direction is determined from the width of the two boundary lines in the transport direction, and the pouring position is determined based on this sand mold length.

In particular, in the present invention, the width of the sand mold is measured after the latest sand mold is pressed against the end of the sand mold row by an extruder, so that the effect of shrinkage of the sand mold due to the above-mentioned pressing can be avoided. In addition, even though the sand mold row is transported by the intermittent transport device, the starting position of the sand mold row can be set to the boundary line position imaged by the imaging means, so even if the transport distance of each time of the intermittent transport device varies, The hot water position can be determined accurately.

[Brief explanation of drawings]

[Figure 1] Plan view of a row of unframed sand molds

[Fig. 2] Block diagram showing one embodiment of the present invention

[Figure 3] Process diagram showing the sand mold row production procedure

[Figure 4] Process diagram showing the sand mold row production procedure

[Figure 5] Process diagram showing the sand mold row production procedure

[Figure 6] Process diagram showing the sand mold row production procedure

[Figure 7] Process diagram showing the sand mold row production procedure

[Figure 8] Process diagram showing the sand mold row production procedure

[Figure 9] Flowchart showing the operation of the calculation unit

[Figure 10]
Diagram showing the imaging screen

[Fig. 11] Diagram showing the imaging screen

[Figure 12] Enlarged plan view of the boundary area

[Fig. 13] Flowchart showing the boundary line determination subroutine

[Fig. 14] Flowchart showing the boundary line determination subroutine

[Explanation of symbols]

Claims (1)

[Claims] 1. A molding machine that molds a sand mold, an extruder that extrudes the molded sand mold in one direction to form rows of sand molds that are in close contact with each other in a row, and an intermittent conveyance device that transports the rows of sand molds intermittently in the direction in which the sand molds are arranged. and a pouring tube that is movable in the direction of the sand mold arrangement to pour the metal into sprues opened at regular intervals on the upper surface of the sand mold row, and is disposed a predetermined distance away from the extruder in the direction of the sand mold arrangement. In a frameless casting line comprising a machine, an imaging means for capturing an image of a boundary area between adjacent sand molds in a row of sand molds being conveyed and outputting a video signal, and processing the video signal corresponding to the boundary area. a sand mold width determining means that determines a sand mold width in the transport direction from the width in the transport direction of two boundary lines adjacent in the transport direction; a pouring position determining means for determining the current position in the transport direction of the sprue at a predetermined value from the upstream end of the sand mold row as the pouring position, and outputting the determined pouring position to the pouring machine. .