MANUFACTURING PROCESS FOR CASTING MOLD

Abstract

Providing a manufacturing process for a mold suitable for high-mix / low-volume. In the dividing process, mold joining surfaces of the upper and lower molds are each formed by dividing, and cavities C1 and C2 are formed by dividing with reference to the mold joining surfaces of the upper and lower molds, respectively. At least three points PU1 to PU3 that are not on a straight line on the mold joining surface of the lower mold, which is placed on a seating surface in the mold joining process, are measured, and the Z coordinates of the respective points are detected. Furthermore, at least three points PL1 to PL3 that are not on a straight line on the mold joining surface of the upper mold gripped by a gripper arm are measured, and the Z coordinates of the respective points are detected. Then, mold joining is carried out in which a parallel position of the mold joining surfaces SmU and SmL of the upper and lower molds is maintained.

Description

Technical area

[0001] The present invention relates to a manufacturing method for a casting mold. More specifically, it relates to a manufacturing method for a casting mold in which a sand block is prepared by mixing molding sand and a binder, filling / compressing and curing it in a mold frame, and removing it from the mold frame, and a sand mold is produced by a dividing process and a mold bonding process. background

[0002] Regarding the above-mentioned manufacturing method for a casting mold, Patent Literature 1 is known regarding the division process, and Patent Literature 2 is known regarding the mold joining process. In the former case, a sand block forming mold is combined with division to shorten the division process. In the latter case, reference pattern blocks 24 to 27 and reference patterns 28 to 31 used as forming molds are formed in a sand mold, and the sand mold is joined based on the reference patterns.

[0003] However, even this state of the art cannot adequately meet the needs of high-mix / low-volume production of cast products. In the first case, the molding shape of the sand block cannot correspond to a high-mix production. In the second case, a final dimension match is required during the molding of the sand block. In a low-volume production, the precision of the reference samples cannot be guaranteed due to dimensional deviations associated with the hardening conditions. Citation listPatent literature Patent Literature 1: Patent Publication No. JP 2017-131901 A Patent Literature 2: PCT Publication No. JP 2019-536636 A Summary of the inventionTechnical problem

[0004] Taking these conventional circumstances into account, the present invention aims to provide a manufacturing method for a mold suitable for high-mix / low-volume. Solution to the problem

[0005] To achieve this object, the characteristic structure of the manufacturing method for a casting mold according to the present invention is that in a method in which a sand block is prepared by mixing molding sand and binder, filling / compressing and curing in a mold frame and removing it from the mold frame, and a sand mold is prepared by a dividing process and a mold joining process, a robot-operated machining head by which a division of the sand block and a division of an upper and lower mold are carried out, a robot-operated gripper arm that grips the upper mold and connects mold joining surfaces that form a cavity in the upper and lower molds, and a coordinate measuring sensor that detects coordinates by bringing at least the upper mold gripped by the gripper arm into contact with detector pieces,wherein the side surfaces of the sand mold have a slope at which the opposite sides approach each other as they approach the mold connection surface, and gripping surfaces of the gripping arm also have the same slope as the side surfaces of the sand mold, the Z-axis, which defines the Z-coordinate, is aligned in the vertical direction, the machining head forms the mold connection surfaces of the upper and lower molds by cutting in the cutting process, and forms the cavity by cutting with reference to the mold connection surfaces of the upper and lower molds, and in the mold connection process, at least three points that do not lie on a straight line on the mold connection surface of the lower mold, which is placed on a support surface, are measured and the Z-coordinates of the respective points are detected, and after at least three points,which do not lie on a straight line on the mold connection surface of the upper mold gripped by bringing the gripping surfaces of the gripping arm into contact with the side surfaces, and the Z-coordinates of the respective points were detected, a mold connection is made in which a parallel position of the mold connection surfaces of the upper and lower molds is maintained.

[0006] With this structure, the cavity is formed accurately even if the finished dimensions are different after the hardening of the sand block, because the machining head forms the mold connecting surfaces of the upper and lower molds by cutting in the cutting process, and the cavity is formed by cutting with reference to the mold connecting surfaces of the upper and lower molds.Furthermore, mold joining of the upper and lower molds can be performed accurately regardless of the position of the lower mold, since in the mold joining process, at least three points that are not on a straight line on the mold joining surface of the lower mold that is placed on a seating surface are measured and the Z coordinates of the respective points are detected, and after at least three points that are not on a straight line on the mold joining surface with the upper mold gripped by bringing the gripping surfaces of the gripper arm into contact with the side surfaces are measured and the Z coordinates of the respective points are detected, the mold joining by the gripper arm is performed while maintaining a parallel position of the mold joining surfaces of the upper and lower molds.Since the molding from a sand block can be used together for different casting molds, different sand molds can be produced only by cutting them up, so that a high-mix / low-volume requirement can be met.

[0007] In this characteristic, there should be X and Y coordinates which define the transverse direction by the X and Y axes orthogonal to the Z axis, and at least two transverse direction alignment surfaces which are aligned with each other at the intersection angle of the X and Y axes are formed by the machining head in the dicing process near the mold connecting surfaces of the upper and lower molds, each by dicing, in the mold connecting process, the X and Y coordinates of the respective transverse direction alignment surfaces are detected at the upper and lower molds, and a mold connection is carried out by means of the gripper arm by aligning the transverse direction alignment of the upper and lower molds.These characteristics enable precise cross-directional alignment, with one cross-directional alignment surface being divided while dividing the other cross-directional surfaces is not required, thus minimizing the amount of sand to be divided.

[0008] At least one of the at least two transverse alignment surfaces should be provided at two or more locations that are spaced apart (a transverse alignment surface is divided at two or more locations and the transverse alignment surfaces are spaced apart). By providing at least one of the transverse alignment surfaces at two or more locations, an inclination of an edge on the transverse alignment surface side can be detected, thus making the mold connection in the transverse direction more accurate.

[0009] The sand blocks forming the upper and lower molds each show a convex polygon in plan view, wherein the transverse direction alignment surfaces can be formed at a corner of the convex polygon.

[0010] The convex polygon may be a rectangle, with the transverse alignment surface formed at adjacent corners and opposite corners of the rectangle with different division lengths, and with the same division length for the upper and lower molds. According to this structure, the rotational position difference between the upper and lower molds can be immediately detected visually or by image recognition during mold connection. Detection is particularly easy when a transverse alignment surface is formed at all corners of the sand mold.

[0011] In addition to the two transverse alignment surfaces, at least two other transverse alignment surfaces may be present near the mold connection surfaces of the upper and lower molds machined by the robot, all of which are not parallel to each other. Confirmation of the mold connection should be performed by detecting the X and Y coordinates of two points on the other transverse alignment surfaces for the upper and lower molds, respectively. This enables confirmation of the mold connection accuracy, any cutting deviation, etc.

[0012] When the robot divides, the upper surface of the sand blocks should be a structural surface of the cavity. Vertical wall sections should be provided on the side surfaces near the bottom of the sand blocks. Alignment pieces should be brought into contact with the vertical wall sections and serve as a reference for their horizontal coordinates when the robot divides. According to this structure, by reducing the inclination of the sand block, more accurate alignment with the coordinates is possible, thereby aiming to reduce the amount of division. That is, assuming a case where the sand block is inclined to the coordinates, an increase in the amount of division is required to ensure precision, whereas the present invention reduces this requirement.

[0013] A coordinate measuring sensor which measures coordinates by bringing the lower mold into contact with the detector pieces is provided on the gripper arm, wherein, after the lower mold has been placed on a placement surface on which the lower mold is placed, the respective coordinates of the lower mold placed on the placement surface are detected by means of the coordinate measuring sensor, and another coordinate measuring sensor is provided at a location connected to the placement surface on which the lower mold is placed, and the respective coordinates of the upper mold in the gripped state of the upper mold are detected by means of the other coordinate measuring sensor at the upper mold which has been gripped by the gripper arm.According to this structure, the lower mold has its respective coordinates measured in the state placed on the mounting surface, and the upper mold has its respective coordinates measured in the state gripped by the gripper arm. By detecting the positional relationship between the two, variable factors can be minimized during mold joining, so that the mold joining can be performed accurately. Advantageous effects of the invention

[0014] According to the above characteristic structure of the mold manufacturing method according to the present invention, it is achieved that a mold manufacturing method can be provided that can meet a high-mix / low-volume requirement through rational cutting and mold joining. Furthermore, according to another characteristic structure of the present invention, minimizing the amount of cutting of the sand mold and rationalizing processing makes it possible to meet a high-mix / low-volume requirement even better.

[0015] Other objects, structures and effects of the present invention will become apparent from the following details of the forms for carrying out the invention. Character list Fig. 1 is an explanatory view that provides an overview of the entire process. Fig. 2 are views showing a molding process, wherein (a) is a longitudinal cross section of a disassembled molding die, (b) is a longitudinal cross section during molding, and (c) is a plan view in a state of the molding die being removed. Fig. 3 shows a dicing device for performing a dicing process, wherein (a) is a side view and (b) is a plan view of a base. Fig. 4 shows a mold joining device for performing a mold joining process, wherein (a) is a plan view and (b) is a front view. Fig. 5 shows the environment of the gripper arm in Fig. 4, where (a) is a front view and (b) is a top view. Fig. 6 is a perspective view of a sand mold. Fig. 7 is a front view of the sand molds. Fig. Figure 8 is an unfolded top view of the sand molds with the Y-axis as the axis of symmetry. Fig. 9 are views showing the alignment sequence of the coordinates of the upper mold and lower mold, wherein (a) shows the state before the coordinate alignment and (b) after the coordinate alignment, respectively. Description of the embodiments

[0016] Next, the present invention will be explained in more detail with reference to the accompanying drawings. The manufacturing method for a casting mold according to the present invention (overall manufacturing process ST001) has as in Fig. 1 shows a molding process ST100, in which a sand block is produced by mixing molding sand and binder, filling / compressing, and curing in a mold frame, a cutting process ST200, in which sand molds are formed from the sand block by cutting, and a mold joining process ST300, in which the cut upper and lower molds are connected to each other. As processing device 100, a Fig. 2 shown shaping device 110, a in Fig. 3 shown cutting device 120 and one in Fig. 4 and Fig. 5 is used. As the robot 101 of the device 100, a cutting robot 121 is used for the cutting device 120 and a cutting robot 131 is used for the cutting device 130. However, a common robot may also be used and only one processing head or one gripper arm may be exchanged as an accessory.

[0017] A lower mold forming process ST110, a lower mold splitting process ST210, and a lower mold cleaning process ST310 are performed in sequence. Likewise, an upper mold forming process ST130, an upper mold splitting process ST230, and an upper mold cleaning process ST330 are performed in sequence, followed by an upper / lower mold joining process ST350. Fig. Figures 6 to 9 describe a sand mold. First, the sand mold is divided and then joined, and the manufacturing processes are explained in turn. Batch processing can also involve forming upper and lower molds in large quantities, separating them, and storing them at a primary location. Cleaning and joining of the upper and lower sand molds can be performed as needed.

[0018] One in Fig. The sand mold M shown in Figures 6 to 9 comprises an upper mold MU and a lower mold ML. Mold connecting surfaces Sm, at which the upper and lower molds are connected, are an upper mold-mold connecting surface SmU and a lower mold-mold connecting surface SmL, respectively. In these drawings, an X, Y, and Z axes intersecting at a 90-degree angle and their origin O are shown, wherein the direction of the axis is basically the same as that in Fig. 2 to 5. The Z-axis represents the top-bottom direction and is generally vertical, although there is no restriction thereto. Furthermore, the X and Y axes represent the transverse direction and are generally horizontal, although there is no restriction thereto. A cavity C is formed in the upper and lower molds, with an upper cavity C1 and a lower cavity C2 together forming the cavity C. A sprue W1 and a pouring channel (gate) W3 are formed on the upper mold, which continue into a pouring channel W2 and supply molten metal into the cavity C located further forward.

[0019] In the respective sand molds, vertical wall sections Sv rise from a base surface Sb, to which gently inclined side surfaces Ss adjoin the mold connection surface Sm. The vertical wall sections Sv are used, as described below, for transverse alignment during cutting. The gently inclined wall sections Ss serve as a lifting slope to facilitate removal of the sand mold from the forming mold for gripping by the gripper arm described below, and to prevent transverse alignment surfaces from protruding laterally and becoming damaged. This basic structure is the same for the sand block.

[0020] The mold connection surfaces are the upper mold-to-mold connection surface SmU and the lower mold-to-mold connection surface SmL, which are provided on the upper and lower molds, respectively. Using the upper mold-to-mold connection surface SmU and the lower mold-to-mold connection surface SmL, by detecting the Z-axis position at at least three points PU1 to PU3 and PL1 to PL3 that are not on a straight line, a mold connection can be performed in which the upper mold-to-mold connection surface SmU and the lower mold-to-mold connection surface SmL are kept parallel to each other.If these three points PU1 to PU3 and PL1 to PL3 are provided near the corners of the upper and lower molds, respectively, interference with the cavity C is prevented, and in addition, by making the respective points farther apart from each other, the respective inclinations of the upper mold-to-mold connecting surface SmU and the lower mold-to-mold connecting surface SmL can be determined more accurately.

[0021] During mold connection, the position and orientation of the upper and lower molds in the transverse direction are detected and corrected by the transverse direction alignment surfaces. X-axis transverse direction alignment surfaces SUWX1 and SLNX2 for detecting displacement in the X-axis direction are surfaces along the Y-axis. Likewise, Y-axis transverse direction alignment surfaces SUWY1 and SLNY2 for detecting displacement in the X-axis direction are surfaces along the X-axis. Furthermore, the respective transverse direction alignment surfaces on the left side of the paper surface are in Fig. 6 to 9 are wider than the cross-direction alignment surfaces on the right side. For example, the width on the left side is 55 mm and the width on the right side is 35 mm, but there is no limitation. Therefore, the first ones with the third letter W are designated as wide cross-direction alignment surfaces SUW and SLW, and the last ones with the third letter N are designated as narrow cross-direction alignment surfaces SUN and SLN.

[0022] The wide and narrow widths of the transverse direction alignment surfaces are designed to align the upper and lower molds without causing misalignment of the upper and lower molds. Fig. 8, the left side is the wide transverse alignment surface, and the right side is the narrow transverse alignment surface. Furthermore, at all opposite angles, the wide transverse alignment surface and the narrow transverse alignment surface are arranged opposite each other. This arrangement allows for immediate detection of any alignment surface defects if the stacked upper and lower molds are misaligned. This detection can be done visually or automatically using image recognition.

[0023] Following the above specifications, X-axis transverse direction alignment surfaces SUWX1 and SLNX2 and Y-axis transverse direction alignment surfaces SUWY1 and SLNY2 are defined. Furthermore, as an exemplary representation, the upper wide first X-axis transverse direction alignment surface SUWX1 and the lower narrow second Y-axis transverse direction alignment surface SLNY2 are defined.

[0024] Next, the contents of the respective processes and the production facilities used for them are explained in turn.

[0025] First, the forming device 110 used in the forming process ST100 comprises, as shown in Fig. 2, a molding mold 111, a compression platen 112, a lower platen 113, and a molding sand supply device and a swingable compression device, which are not shown. The molding mold 111 is used for an upper block BU and a lower block BL, but only one alignment pin 113b is provided in common for the lower platen 113, and a sprue mold 113a is provided only for the upper block BU. By using the mold in common for the upper block BU and the lower block BL as much as possible, it is intended to reduce molding deviations. Furthermore, the provision of the sprue mold 113a reduces the amount of cutting of the sand mold, and since inverted cutting from the back is not required for cutting the sprue, the man-hours for sand mold production are reduced.

[0026] The dicing device 120 used in the dicing process ST200 comprises, as shown in Fig. 3, a dicing robot 121, a foundation floor 124, a seating surface 125, and alignment pieces 126. The dicing robot 121 has a multi-joint arm 121b on a base pedestal 121a, which is connected to the foundation floor 124 and the seating surface 125, and can freely move a machining head 122, which rotates a tool 123 such as a cutting device, in the X, Y, and Z directions.

[0027] The origin O of the coordinate axes is set to match the alignment pieces 126 of the seating surface 125. For ease of understanding, in the drawings, the origin O on the seating surface 125 is defined at the intersection point of an extension of an X-axis alignment piece 126X for alignment in the X-axis direction along the Y-axis and an extension of a Y-axis alignment piece 126Y for alignment in the Y-axis direction along the X-axis. In the respective sand molds, vertical wall portions Sv rise from a bottom surface Sb, and by bringing both alignment pieces 126 and pressing pieces 127 into contact, the transverse direction position of the sand blocks is adjusted to the origin O, so that the amount of fragmentation is minimized.Specifically, the vertical wall sections Sv are fixed and supported by both an X-axis alignment piece 126X and two Y-axis alignment pieces 126Y, and by approaching and bringing into contact an X-axis pressing piece 127X and a Y-axis pressing piece 127Y to the vertical wall sections Sv on the respective opposite edge sides, the inclination in the X and Y directions is regulated.

[0028] If the cutting sequence is to first cut the lower mold ML and then cut the upper mold MU, the upper mold MU can be directly used for mold joining after cleaning in the subsequent mold joining process, which has the advantage of shortening the process, but the cutting sequence is not limited to this. When cutting the respective locations, it is preferable to first cut the mold joining surfaces SmU and SmL of the respective sand blocks BU and BL, and then cut the transverse direction alignment surfaces SU and SL, the cavity C, the runner W2, and so on. If cutting is performed with reference to the mold joining surfaces SmU and SmL, the cavity C, the runners W2 and W3, etc., are formed accurately as a whole, and reliable alignment in the transverse direction is also achieved.

[0029] The mold connecting device 130 used in the lower mold cleaning process ST310, the upper mold cleaning process ST330 and the upper / lower mold mold connecting process ST350 comprises, as shown in Fig. 4 and Fig. 5, the mold joining robot 131, an air cleaning cell 133, a foundation floor 134, a support surface 135, a first coordinate measuring sensor 136 and a second coordinate measuring sensor 137.

[0030] The mold connecting robot 131 comprises, on a base pedestal 131a, a gripper arm 132 at the front end of an arm 131b, the front end of which is freely movable in three-dimensional directions. The gripper arm 132 can grip the sand mold M between an opposing pair of gripping surfaces 132a by approaching and distancing a pair of gripping pieces. The side surfaces Ss of the sand mold M, unlike the vertical wall sections Sv, have a taper, in which the opposite sides approach each other following the approach to the mold connecting surfaces Sm. The gripping surfaces 132a have the same taper, wherein in particular, due to the gripping surfaces 132a as in Fig. 5 in the downward state of the mold connecting surface Sm of the upper mold MU are brought into contact with the side surfaces Ss, a downward positional shift of the upper mold MU can be prevented.

[0031] The air cleaning cell 133 serves to clean the fragmentation waste, such as sand grains, adhering to the sand mold M. The cleaning is carried out by blowing away the fragmentation waste by means of an air stream from an air nozzle 133b provided below an air cleaning chamber 133a and having a plurality of air openings.

[0032] The mold connecting robot 131 and the support surface 135 are provided on the foundation floor 134. Furthermore, the first coordinate measuring sensor 136 is provided on the gripper arm 132, and the second coordinate measuring sensor 137 (another coordinate measuring sensor) is provided on the foundation floor 134. The first and second coordinate measuring sensors 136, 137 each detect spatial coordinates of an object in contact on the X, Y, and Z coordinate axes with detector pieces 136a and 137a. The coordinate positions of the respective surfaces Sm, SU, and SL are detected by the first coordinate measuring sensor 136 of the gripper arm 132 for the sand mold M on the support surface 135, and by the second coordinate measuring sensor 137 on the foundation floor 134 for the sand mold M gripped by the gripper arm 132.

[0033] In this setup, after the lower mold cleaning process ST310 and the upper mold cleaning process ST330, the coordinates in the respective processes are acquired, and based on the results, the upper / lower mold joining process ST350 is executed. The upper mold cleaning process ST330 is similar to the lower mold cleaning process ST310, with only different sections described below.

[0034] In the lower mold cleaning process ST310, first, the lower mold ML, in which the dicing process is completed, is placed with the mold joining surface Sm facing upward on one of the first to third seating surfaces 135a to c of the seating surface 135. Then, the positions of the plurality of transverse-direction joining surfaces SL are measured by the detector pieces 136a of the first coordinate measuring sensor 136, the lower mold ML is gripped by the gripper arm 132, inversely rotated about an inverse axis parallel to the X-axis, and introduced into the air cleaning chamber 133a of the air cleaning cell 133, where an air flow is directed from the lower side onto surfaces including the shape of the cavity C by means of the air nozzle 133b, and cleaning is performed.

[0035] Subsequently, it is again placed around the inverse axis with the mold connection surface Sm facing upward onto one of the first to third seating surfaces 135a to c of the seating surface 135. Then, by means of the detector pieces 136a of the first coordinate measuring sensor 136 of the gripper arm 132, the positions of the mold connection surfaces Sm and the transverse direction alignment surfaces SL are measured as described below, and the mold connection is started.

[0036] The upper mold cleaning process ST330 is similar up to the cleaning stage, but differs in the following points. The upper mold MU gripped by the gripper arm 132 is brought close to the detector pieces 137a of the second coordinate measuring sensor 137 on the foundation floor 134 with the mold joining surface Sm facing downwards, the positions of the mold joining surfaces Sm and the transverse direction alignment surfaces SL are measured as described below, and the mold joining is initiated.

[0037] With regard to the mold connection surfaces Sm, the upper mold connection surface SmU, as shown in Fig. 7 and Fig. 8, the Z coordinates of at least three points PU1 to 3 that are not on the same straight line are detected. Similarly, for the lower mold connecting surface SmL, the Z coordinates of at least three points PL1 to 3 that are not on a straight line are detected. Even if different positions are selected in the transverse direction, the position of the upper surface MU is finally determined by the mold connecting robot 131, as in the following example. Fig. 9 is set so that the inclination of the lower mold connecting surface SmL and the inclination of the upper mold connecting surface SmU are parallel, and the two mold connecting surfaces SmU and SmL are approximated and connected.

[0038] For the transverse direction alignment surfaces SU and SL, as in Fig. 7 and Fig. 8, two locations of the Y-axis transverse direction alignment surfaces SUWY1, SUWY2, SLWY1, SLWY2 and one location of the X-axis transverse direction alignment surfaces SUNX1, SLNX1 are measured for each of the upper and lower molds MU and ML. Then, the joining robot 131 adjusts the posture of the upper mold MU so that the positions of the respective alignment surfaces of the upper mold MU and the lower mold ML coincide, and the two mold joining surfaces SmU and SmL are approximated and joined.

[0039] If only the transverse direction is required, one location on the X transverse direction alignment surface and one on the Y transverse direction alignment surface is sufficient for the upper and lower molds MU and ML, respectively. However, by measuring two locations on the Y transverse direction alignment surfaces SUWY1, SUWY2, SLWY1, and SLWY2 at spaced locations, tilt in the vicinity of an axis parallel to the Z axis can be corrected.

[0040] Regarding the alignment of the coordinates in the mold connection, by measuring the transverse direction alignment surfaces SLWX1, SLWY1, SLWY2 and the three points PL1 to 3 on the lower mold connection surface SmL of the lower mold ML in Fig. 7 and Fig. 8 the position and location of in Fig. 9(a), which are defined by the side surfaces and the mold connection surface SmL of the lower mold ML, to the X, Y, and Z coordinate axes of the mold connection device 130 shown by dashed lines. Likewise, the position and location of Fig. 9(a) shown Xu, Yu and Zu coordinate axes defined by the side surfaces and the mold connecting surface SmU of the upper mold MU, to the X, Y and Z coordinate axes shown by dashed lines (where -Z is the negative direction of Z and -ZI is the negative direction of ZI, and respective illustrated vectors are substantially equal).

[0041] Subsequently, the position and attitude of the gripper arm 132 of the mold joining robot 131 are adjusted, and by adjusting the attitude and approaching such that the XI, YI and ZI coordinate axes coincide with the Xu, Yu and Zu coordinate axes, the coordinates are aligned and an accurate mold joining can be performed.

[0042] Furthermore, as a transverse direction coordinate control after the mold connection, as in Fig. 7 and Fig. As shown in Figure 8, one location of the Y-axis transverse direction alignment surfaces SUNY2, SLNY2 and one location of the X-axis transverse direction alignment surfaces SUNX2, SLNX2 were measured for the upper and lower molds MU and ML, respectively. The matching of these upper and lower coordinates enables precise control of the mold connection.

[0043] After this mold joining process, the mold M is transported to a known casting process. Starting from the sprue W1 side, pouring takes place and the mold is completed.

[0044] Finally, other embodiments of the present invention will be explained. The present invention is not limited to the above and following embodiments and can be modified as long as it does not deviate from the gist of the present invention. In the following explanations, the same components as in the above embodiment are provided with the same adjustments.

[0045] The X, Y, and Z axes do not necessarily have to be at a 90-degree angle to each other, but acquiring the coordinates is easier if they are at a 90-degree angle to each other. As long as the intersection angle of the cross-direction alignment surfaces is equal to the intersection angle of the X and Y axes, alignment is possible by acquiring the coordinates of only one axis direction of either the X or Y axis.

[0046] Mold connection control becomes more convenient when the positions of the X, Y, and Z coordinate axes are detected by appropriate coordinate conversion using a known method. For example, in the ST300 mold connection process, if the lower mold-to-mold connection surface SmL is not parallel to the XY plane, the upper mold-to-mold connection surface SmU can be kept parallel to the lower mold-to-mold connection surface SmL by performing coordinate conversion of the XY plane from the origin O with the lower mold-to-mold connection surface SmL as the reference surface, setting the vertical axis orthogonal to it, and detecting by measuring the three points in the vertical direction.Likewise, when a surface defined by the lower wide first and second Y-axis transverse direction alignment surfaces SLNY1, Y2 is not parallel to the XZ plane, the respective transverse direction alignment surfaces can be detected by a coordinate conversion of the X-axis and Y-axis from the origin O with the lower wide first and second Y-axis transverse direction alignment surfaces SLNY1, Y2 as reference surfaces.

[0047] The above selection of the cross-direction alignment surfaces are merely examples, and a cross-direction alignment surface of any corner can be selected.

[0048] In the above embodiment, sand blocks were used which are substantially square in plan view, but the shape of the sand blocks can be changed as appropriate, e.g., into a rectangle, triangle, or a polygon with more corners.

[0049] The mold connection surface is a continuous surface at a single location on the upper and lower molds, but it can also be divided into two or more locations. In the latter case, three points can be measured at one location on the upper and lower mold connection surfaces, or three points can be measured on the respective divided mold connection surfaces. The positions of the mold connection surfaces to be aligned should be parallel on the upper and lower molds. The alignment procedure in Fig. According to Figure 9, for the Z coordinates of at least three points PU1 to PU3 and PL1 to PL3 that are not on a straight line, it is not necessary to select locations at the transverse direction positions of the respective top and bottom sand molds that have the same coordinates. However, if the top and bottom sand molds are selected at the transverse direction positions that have the same coordinates, and the relationship between the measurement points on the Z axis at the respective locations is determined, it becomes easier to derive the inclination of the mold connection surfaces SmU and SmL, and the control parameters of the mold connection are also simplified.

[0050] With respect to the at least three points PU1 to PU3 and PL1 to PL3 that are not on a straight line, four or more points may be measured. By means of a mathematical and geometric method such as estimating a surface by measuring at least four points and eliminating points where deviation is suspected, the upper and lower mold connection surfaces can be estimated and approximated in a parallel state, without being limited to the method for adjusting the coordinates in Fig. 9 exists. Industrial applicability

[0051] The present invention can be used as a manufacturing method for a casting mold. It is particularly suitable for high-mix / low-volume production, and can also provide a casting mold with a low dimensional deviation. List of reference symbols 100 processing equipment 101 Robots 110 Shaping device 111 Shaping mold 112 compression plate 113 Lower plate 113a sprue mold 113b Alignment pin 120 cutting device 121 cutting robots 121a base socket 121b Arm 122 machining head 123 tools 124 Foundation soil 125 contact area 126 alignment piece 126X X-axis alignment piece 126Y Y-axis alignment piece 127 Pressure piece 127X X-axis pressure piece 127Y Y-axis pressure piece 130 mold connection device 131 mold joining robots 131a base socket 131b Arm 132 gripper arm 132a Gripping surface 133 Air purification cell 133a Air purification chamber 133b Air nozzle 134 Foundation soil 135 contact surface 135a to c First to third contact surface 136 First coordinate measuring sensor 136a Detector piece 137 Second coordinate measuring sensor (other coordinate measuring sensor) 137a Detector piece B Sand block BU Upper Block BL Lower Block M sand mold MU Upper Form ML Lower Form SmU upper mold-to-mold connection surface SmL lower mold-mold connection surface O XYZ origin (reference of spatial coordinates), Z axis (vertical axis), X and Y axes orthogonal to the Z axis (transverse axes) C Cavity C1 Upper cavity C2 Lower cavity W1 sprue W2 pouring channel W3 Pouring channel (sprue) SU, SL transverse direction alignment surface SU Upper Transverse Alignment Surface SL Lower Transverse Alignment Surface Ss side surface Sv Vertical wall section Sb floor area SUW, SLW Width of transverse direction alignment surface SUN, SLN Narrow cross-direction alignment surface SUWX1, SLNX2 X-axis transverse direction alignment surface SUWY1, SLNY2 Y-axis transverse direction alignment surface SUWX1 (Example) Upper wide first X-axis cross direction alignment surface SLNY2 (Example) Lower narrow second Y-axis cross-direction alignment surface PU1 to PU3, PL1 to PL3 At least three points that do not lie on a straight line ST001 Overall manufacturing process ST100 molding process ST110 Lower mold forming process ST130 Upper-Mold Forming Process ST200 cutting process ST210 Lower-mold cutting process ST230 Upper-mold cutting process ST300 mold joining process ST310 Lower mold cleaning process ST330 Upper-Mold Cleaning Process ST350 Upper / Lower Mold Joining Process

Claims

[1] A manufacturing method for a casting mold, in which a sand block is produced by mixing molding sand and binder, filling / compressing and curing in a mold frame and removing it from the mold frame, and a sand mold is produced by a dividing process and a mold joining process, a robot-operated machining head by which a division of the sand block and a division of an upper and lower mold are carried out, and a robot-operated gripper arm which grips the upper mold and connects mold joining surfaces which form a cavity in the upper and lower molds, and a coordinate measuring sensor which detects coordinates by bringing at least the upper mold gripped by the gripper arm into contact with detector pieces, wherein side surfaces of the sand mold have a slope,in which, following the approach to the mold connection surface, the opposite sides approach each other, and gripping surfaces of the gripper arm also have the same inclination as the side surfaces of the sand mold, the Z-axis, which determines the Z coordinate, is aligned in the vertical direction, the machining head forms the mold connection surfaces of the upper and lower molds by dividing them in the dividing process, and with reference to the mold connection surfaces of the upper and lower molds, forms the cavity by dividing them, and in the mold connection process, at least three points that do not lie on a straight line on the mold connection surface of the lower mold, which is placed on a support surface, are measured and the Z coordinates of the respective points are recognized, and after at least three points,which do not lie on a straight line on the mold connection surface of the upper mold gripped by bringing the gripping surfaces of the gripping arm into contact with the side surfaces, and the Z-coordinates of the respective points were detected, a mold connection is made in which a parallel position of the mold connection surfaces of the upper and lower molds is maintained. [2] A manufacturing method for a casting mold according to claim 1, wherein there are X and Y coordinates which define the transverse direction by the X and Y axes orthogonal to the Z axis, and at least two transverse direction alignment surfaces which are aligned with each other at the intersection angle of the X and Y axes are formed by the machining head in the dicing process near the mold joining surfaces of the upper and lower molds, respectively by dicing, in the mold joining process, the X and Y coordinates of the respective transverse direction alignment surfaces are detected at the upper and lower molds, respectively, and by means of the gripper arm, a mold joining is carried out by adjusting the transverse direction position of the upper and lower molds. [3] A manufacturing method for a mold according to claim 2, wherein at least one of the transverse direction aligning surfaces is provided at two or more locations spaced apart. [4] A manufacturing method for a casting mold according to claim 3, wherein the sand blocks constituting the upper and lower molds each show a convex polygon in plan view, and the transverse direction alignment surfaces are formed at a corner of the convex polygon. [5] A manufacturing method for a casting mold according to claim 4, wherein the convex polygon shows a rectangle, and the transverse direction alignment surface is formed at adjacent corners and opposite corners of the rectangle with a different division length and at the upper and lower molds respectively with the same division length. [6] A manufacturing method for a casting mold according to claim 2, wherein, apart from the two transverse direction alignment surfaces near the mold joining surfaces of the upper and lower molds machined by the robot, there are at least two other transverse direction alignment surfaces each of which does not become parallel to each other, and by detecting the X and Y coordinates of two points on the other transverse direction alignment surfaces in each of the upper and lower molds, confirmation of the mold joining is carried out. [7] A manufacturing method for a casting mold according to claim 2, wherein, in the cutting by the robot, the upper side of the sand blocks is a structural surface of the cavity, vertical wall portions are provided on side surfaces near the bottom of the sand blocks, and alignment pieces are brought into contact with the vertical wall portions and serve as a reference for their horizontal coordinates in the cutting by the robot. [8] A manufacturing method for a casting mold according to any one of claims 1 to 7, wherein a coordinate measuring sensor which measures coordinates by bringing into contact with the detection pieces is provided on the gripping arm, by means of the coordinate measuring sensor, after the lower mold is placed on a seating surface on which the lower mold is placed, the respective coordinates of the lower mold placed on the seating surface are detected, and another coordinate measuring sensor is provided at a position connected to the seating surface on which the lower mold is placed, and by means of the other coordinate measuring sensor, on the upper mold which has been gripped by the gripping arm, the respective coordinates of the upper mold in the gripped state of the upper mold are detected.

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