Post-pouring mold removal device and post-pouring mold removal method

Abstract

Provided is a post-pouring mold removal device using an electric motor that can solve the problem of installation space and reduce equipment costs and running costs.　The post-pouring mold removal device comprises: an electric motor; a lifting frame that is capable of pressing and lowering the upper surface of a sand mold portion of the post-pouring mold; an arm member which swings in the vertical plane and in which a fulcrum serving as a rotation center, a force point to which the driving force of the electric motor is applied, and an operating point that rotates on the basis of a driving force applied to the force point are set, the operating point is disposed above the lifting frame, and at least the force point is disposed at a position displaced from above the lifting frame; a driving force transmission mechanism provided between the electric motor and the force point of the arm member; a link member that links the operating point of the arm member and the lifting frame at the top of the lifting frame; and a lowering restriction device that comes into contact with a casting frame and restricts the lowering of the casting frame when the lifting frame is lowered.

Description

Apparatus and method for removing poured mold

[0001] The present invention relates to a mold removal device for removing a poured mold from a molding flask, and a mold removal method using the device.

[0002] A conventional method for removing a poured mold from a flask involves using a cylinder device to drop the mold directly below the flask, which then drops the poured mold onto a recovery device, such as a shake-out machine or a vibrating conveyor, and transports it to the next process where it is deburred and inspected.

[0003] This method requires a large amount of power to remove the mold from the flask, so a hydraulic cylinder is generally used.

[0004] However, hydraulic cylinders require a hydraulic unit to operate and control the cylinder, and the hydraulic pump motor is often constantly running during production, which poses the problem of high power consumption.For this reason, in recent years, non-hydraulic cylinders have been studied with the aim of saving energy by reducing power consumption, and efforts are being made to electrify actuators.

[0005] Taking into consideration the characteristics of extrusion of a poured mold, the inventors have proposed an extrusion device (punch down) for a poured mold as described in Patent Document 1. This extrusion device for a poured mold generates a large amount of pressure with a short stroke at the beginning of removal, and then generates a slightly longer stroke, although not as much force, to eject the mold (sand mold portion) downward, which is an excellent device that meets the functions required during extrusion.

[0006] Patent application 2022-132217

[0007] However, the poured mold ejection device of Patent Document 1 has a structure in which the main part of the drive mechanism that transmits the driving force from the electric motor as an extraction force is limited to being located directly above the lifting frame that extracts the mold. This creates a problem of space restrictions when installing the device. There was also a demand for an electric motor with a smaller torque to reduce equipment costs and running costs.

[0008] The present invention has been made in view of the above-mentioned problems of the prior art, and its object is to provide an apparatus and method for removing a poured mold which eliminates the problem of installation space in a mold removal device using an electric motor and which is capable of reducing equipment costs and running costs.

[0009] The poured mold extractor of the first aspect of the present invention comprises an electric motor, a lifting frame that can be lowered by pressing against the top surface of the sand mold portion that is inside the flask of the poured mold, and an arm member that extends laterally and has a fulcrum that serves as the center of rotation, a force point to which the driving force of the electric motor is applied, and a point of action that rotates based on the driving force applied to the force point,

[0010] The system comprises an arm member whose point of application is located above the lifting frame and whose force point is at least located away from the top of the lifting frame and which swings within an imaginary vertical plane; a drive force transmission mechanism provided between the electric motor and the force point of the arm member; a link member extending vertically above the lifting frame and connecting the point of application of the arm member to the lifting frame; and a descent restriction device that abuts against the molding flask when the lifting frame is lowered to restrict the descent of the molding flask.

[0011] This allows the area around the force point PF, which is equipped with the main drive mechanism, to be located away from the position directly above the mold extrusion position, thereby eliminating the problem of limited installation space. Furthermore, because the arm member is configured to operate on the principle of leverage, a low-torque electric motor can be used at the force point, making it possible to select an inexpensive electric motor, thereby reducing equipment costs and running costs during use.

[0012] According to the second aspect of the poured mold removal apparatus of the present invention, in the apparatus of the first aspect, the drive force transmission mechanism comprises a first mechanism that generates the force necessary to shift the sand mold portion formed in the molding flask downward from the molding flask, and a second mechanism that moves the sand mold portion shifted by the first mechanism further downward, wherein the force generated by the first mechanism for shifting is greater than the force generated by the second mechanism for moving the sand mold portion downward, and the speed at which the second mechanism moves the sand mold portion downward is faster than the speed at which the first mechanism shifts it.

[0013] According to this, when a load is applied to a force point using the principle of leverage, a first mechanism is used to shift a sand mold portion formed in the flask downward from the flask, which requires a large force, and a second mechanism, which operates faster, is used to move the sand mold portion shifted by the first mechanism downward.

[0014] In this way, the high load region where the load is lowered at a slow speed and the low load region where the load is lowered at a high speed can be made to function efficiently according to the load required to remove the mold, without changing the output of the electric motor itself, which is the driving source.

[0015] According to a third aspect of the poured mold removal apparatus of the present invention, in the apparatus of the second aspect, the first mechanism comprises a rotating arm whose tip rotates at a predetermined radius when driven by the electric motor, and the second mechanism comprises a first link member whose base end is connected to the tip of the rotating arm and which is wound around the rotating arm so that its tip rotates at a radius larger than the radius of rotation of the rotating arm.

[0016] With this, the high load range for slow lifting is achieved by rotating the rotary arm and winding up the first link member, and the low load range for fast lifting is achieved by winding up the point of force of the arm member with the first link member that is wound up on the rotary arm and has a tip end with a larger radius of rotation than the rotary arm.

[0017] According to the fourth aspect of the present invention, in the apparatus for removing a poured mold, in the apparatus of the first aspect of the present invention, the fulcrum of the arm member is provided between the force point and the point of action, and the fulcrum has two fulcrums: a first fulcrum and a second fulcrum that is positioned closer to the force point than the first fulcrum, and the first fulcrum is used when shifting the sand mold portion formed in the molding flask downward from the molding flask, and the second fulcrum is used in place of the first fulcrum when moving the shifted sand mold portion further downward.

[0018] According to this, when the same arm member is used and the first fulcrum is used, the point of application is closer and the point of force is farther away than when using the second fulcrum, so that, according to the principle of leverage, the point of application tends to generate a large force despite a short travel distance.When the second fulcrum is used, it is difficult to generate a large force at the point of application, but the travel distance is long and the downward movement speed can be increased.

[0019] According to the fifth aspect of the present invention, in the apparatus for removing a poured mold of the fourth aspect of the present invention, the first and second fulcrums are provided with rollers having rotation axes extending in a direction perpendicular to the vertical plane in which the arm members swing, and receiving parts each having a crescent-shaped recess corresponding to the outer periphery of the roller, the crescent-shaped recess removably supporting the outer periphery of the roller in the vertical direction.

[0020] With this, even when the first fulcrum and the second fulcrum each serve as a fulcrum, the freely rotating roller and the receiving portion corresponding to the shape of the roller prevent the center of rotation of the arm member from becoming misaligned.The first fulcrum and the second fulcrum, which do not cause such misalignment, can be easily and smoothly switched between them.

[0021] According to the sixth aspect of the apparatus of the present invention, in the poured mold removal apparatus of the fifth aspect of the present invention, a roller guide is provided at the first fulcrum to guide the trajectory of the roller that has come off the receiving portion.

[0022] According to this, when the effective fulcrum switches to the second fulcrum, the roller that was the first fulcrum moves away from the receiving part, but the trajectory of movement is regulated by the roller guide, so that stable and safe movement can be achieved.

[0023] According to the seventh aspect of the present invention, in the poured mold removal apparatus of the first aspect of the present invention, an upward force generating device is provided which generates an upward force that reduces the downward force generated at the application point of the arm member by the weight of the lifting frame and the link member.

[0024] If the weight of the lifting frame and the link members creates a large downward force, the lifting frame may descend faster than the drive shaft during the process of lowering the filled mold, which could cause problems with the operation of the drive transmission mechanism.

[0025] Specifically, the rotating arm, the first link member, and the second link member are smoothly wound up from a linearly extended state by the rotation of the rotating arm.

[0026] However, if the descending speed of the lifting frame becomes faster than the rotation of the rotating arm, the straight extension cannot be maintained, and bending occurs due to slack between the rotating arm and the first link member, and between the first link member and the second link member, hindering smooth winding operation.

[0027] The upward force generating device prevents the descending speed of the lifting frame from becoming faster than the rotation speed of the rotating arm, thereby realizing a smooth winding operation.

[0028] According to an eighth aspect of the poured mold removing apparatus of the present invention, in the apparatus of the seventh aspect of the present invention, the upward force generating device generates an upward force by the gravity of a weight via a pulley.

[0029] This makes it possible to reduce the downward force that affects the operation of the drive force transmission mechanism by using a simple mechanism that uses the gravity of the weight, without providing a dedicated device for generating drive force.

[0030] According to a ninth aspect of the present invention, in the apparatus for removing a poured mold of the third aspect of the present invention, the rotating arm, the arm member, and the link member move on the same plane, which allows the rotating arm, the arm member, and the link member to be arranged compactly, thereby saving space.

[0031] According to a tenth aspect of the present invention, there is provided a poured mold removal method using the apparatus of the first aspect, which comprises a shifting step of relatively shifting the sand mold portion in the vertical direction to remove it from the molding flask, and a downward moving step of moving the sand mold portion shifted in the shifting step downward with a force smaller than that used in the shifting step and at a speed greater than that used in the shifting step.

[0032] This allows for a large force to be applied to the force point using the principle of leverage in the shifting process, which shifts the sand mold portion formed in the flask upward from the flask. Furthermore, a high speed can be achieved in the downward movement process, which moves the shifted sand mold portion downward. This allows for efficient work that is well suited to the mold removal process.

[0033] FIG. 1 is a schematic diagram, seen from the front, partially in cross section, of a first embodiment of the apparatus for removing a poured mold of the present invention. FIG. 1 is a cross-sectional view taken along the line II-II in FIG. 1. FIG. 2 is a schematic diagram of a pulley shown in plan view. FIG. 1 is a cross-sectional view taken along the line IV-IV in FIG. 1. FIG. 1 is a cross-sectional view taken along the line V-V in FIG. 1. FIG. 2 shows the state after the rotating arm has been rotated 180 degrees from its initial position. FIG. 3 shows the state after the rotating arm has been rotated 360 degrees from its initial position, the sand mold portion has been removed, and the casting has been dropped. FIG. 3 is a schematic diagram, seen from the front, partially in cross section, of a second embodiment of the apparatus for removing a poured mold of the present invention. FIG. 4 shows the state after the rotating arm has been rotated 180 degrees from its initial position, the sand mold portion has been removed, and the casting has been dropped.

[0034] First Embodiment A first embodiment of the poured mold removing apparatus according to the present invention will be described below with reference to FIGS. 1 to 7. FIG.

[0035] 1, the horizontal direction extending from side to side is referred to as the X-axis direction, and the horizontal direction perpendicular to the X-axis direction is referred to as the Y-axis direction. Furthermore, if a virtual center line is considered for a tangible object, the side closer to the center line is referred to as the inside, and the side farther from the center line is referred to as the outside.

[0036] As shown in Figure 1, the poured mold removal device 1 in this embodiment includes a support stand 2, an electric motor EM, a drive force transmission mechanism 3, an arm member 4, a link member 5, a lifting frame 6, and a descent restriction device 7.

[0037] (Support pedestal) The support pedestal 2 supports the electric motor EM and the shaft support member 25 on its upper surface. The support pedestal 2 is made of, for example, iron and includes a support column 21, an upper support base 23, an upper support column 24, and a top plate 22. As shown in FIG. 1 , the upper part of the support pedestal 2 is formed in a two-step staircase shape with the left side higher in the X-axis direction.

[0038] The four support pillars 21 are made of, for example, iron and formed into rod shapes with square cross sections. The four support pillars 21 are erected from the floor surface BF and extend to the height of an upper support base 23, which will be described later.

[0039] The upper support base 23 is formed of, for example, a rectangular iron plate and is arranged horizontally with its long sides extending along the X-axis direction. The tips of the left-side support columns 21 are connected to the two left-side corners of the upper support base 23 in Figure 1. The upper support base 23 has a large opening 2a through which the lifting frame 6 (described later) passes, and a small opening 2b through which the connected first link member 31 and second link member 32 (described later) pass.

[0040] The large opening 2a has an opening in the X-axis direction that is the distance between two adjacent columns 21 minus the length of one column 21, and an opening in the Y-axis direction that is the distance between two adjacent columns 21 (see FIG. 2). The small opening 2b has a rectangular shape extending along the X-axis. A pair of electric motors EM are arranged on either side of the small opening 2b (see FIG. 5).

[0041] (Upper Supports) As shown in Fig. 1, the upper supports 24 are erected on the upper support base 23 and support the top plate 22. In Fig. 1, the two upper supports 24 on the left are provided at the corners of the upper support base 23, and the two upper supports 24 on the right are provided adjacent to the open end of the large opening 2a. The tip of each upper support 24 is connected to the lower corner of the top plate 22.

[0042] (Top Plate) The top plate 22 supports the shaft support member 25, the upward force generator 8, and the guide portion 64. The top plate 22 is formed of, for example, a rectangular thick iron plate. As shown in FIG. 2 , the top plate 22 is provided with a first opening 2c through which the link member 5 passes and a second opening 2d through which the wire rope 83 of the pulley 81 passes.

[0043] The first opening 2c is formed in the top plate 22 at a position slightly shifted to the right of the center in the X-axis direction (see FIG. 5), and has a rectangular shape that is slightly elongated in the Y-axis direction.

[0044] 2, the second openings 2d are provided on both sides of the first opening 2c and the cylindrical portion 64a of the guide portion 64 in the Y-axis direction. The second openings 2d are formed by small circular holes aligned in the Y-axis direction.

[0045] As shown in Fig. 4, bearing members 105 are provided at the opening ends aligned in the Y-axis direction of the small opening 2b on the lower right surface of the support pedestal 2 in Fig. 1. These bearing members 105 rotatably support a drive rotation shaft EMb, which will be described later. Of the bearing members 105, the bearing member 105 on the right side in Fig. 4 is provided with a regulating roller 105a, which will be described later. In Fig. 4, a rotation angle sensor (not shown) is provided on the left side next to the bearing member 105, which detects the rotation angle, rotation direction, and rotation speed of the rotation arm 30 and transmits the detected values ​​to a control device (not shown).

[0046] (Electric Motor) As shown in FIG. 4, two electric motors EM are fixed to the upper support base 23 with their output shafts EMa facing each other. As the electric motors EM, for example, servo motors are used. When using two electric motors EM to swing the arm member 4, it is desirable to drive one of the two electric motors EM as a master and the other as a slave in order to synchronously control these electric motors EM. Note that, in some cases, inverter-controlled motors can also be used as these electric motors EM.

[0047] The output shafts EMa of the two electric motors EM are connected to a single rotary drive shaft EMb via couplings. A pair of rotary arms 30 (described below) are attached to the rotary drive shaft EMb so as to be aligned in the direction in which the rotary drive shaft EMb extends and are non-rotatable relative to each other. The rotary arms 30 form part of a drive force transmission mechanism 3 (described below).

[0048] (Driving Force Transmission Mechanism) The driving force transmission mechanism 3 transmits the driving force of the electric motor EM to the arm member 4. As shown in FIG. 1 , the driving force transmission mechanism 3 of the first embodiment includes a rotating arm 30, a first link member 31, and a second link member 32.

[0049] (Rotating Arm) The rotating arm 30 is, for example, two oval iron plates arranged opposite each other and mounted around a drive rotation shaft EMb connected to the output shafts EMa of the two electric motors EM so as not to rotate relative to the drive shaft EMb, as shown in Fig. 4. As shown in Fig. 1, each oval plate of the rotating arm 30 has an acutely pointed top at one end and a semi-disk-shaped protrusion at the other end that forms part of the first connecting part FCP.

[0050] The drive rotation shaft EMb is rotatably supported by a bearing member 105 that is fixed to the upper support base 23 and is provided with a ball bearing (see FIG. 4). The bearing members 105 are provided in pairs with the rotation arm 30 in between, and a restricting roller 105a is provided protruding from one of the bearing members 105. The restricting roller 105a is provided to come into contact with an arc-shaped portion ASP of a first link member 31 (described later) to guide the rotation of the first link member 31.

[0051] The first connecting portion FCP connects the rotating arm 30 to a first link member 31, which will be described later. As shown in Fig. 4 , the first connecting portion FCP of the rotating arm 30 has connecting holes (not shown) formed in two plates, and a pivot pin AP passes through the connecting holes. The pivot pin AP passes through a lower connecting hole (not shown) of the first link member 31, which will be described later, and supports the first link member 31 rotatably with respect to the rotating arm 30.

[0052] 1, a locking portion LP is formed on one end of the rotating arm 30 where the top is provided, on the side in the direction of rotation when the rotating arm 30 winds up the first link member 31. The locking portion LP has a linear edge formed from the top to the base, and abuts against a locked portion LEP of the first link member 31, which will be described later. By abutting the locked portion LEP against the locking portion LP in this way, the first link member 31 can be wound up neatly onto the rotating arm 30.

[0053] (First Link Member) The first link member 31 connects the rotary arm 30 and the second link member 32. The first link member 31 is formed of, for example, a single iron plate.

[0054] As shown in Figure 4, the first link member 31 is arranged so that the end connected to the rotating arm 30 is sandwiched between two plates of the rotating arm 30. A lower connecting hole (not shown) is formed in the first connecting part FCP on the rotating arm 30 side of the first link member 31, and a bearing that rotatably supports the pivot pin AP is provided in the lower connecting hole (not shown). The distance L1 from the center of the drive rotation shaft EMb to the center of the lower connecting hole (the center of the first connecting part FCP) is the rotation radius of the rotating arm 30 (see Figure 6). The rotating arm 30 corresponds to the first mechanism.

[0055] The end of the first link member 31 that is connected to the rotating arm 30 side is bent along the winding direction, as shown in Fig. 1. The inner periphery of the bent end of the first link member 31 is formed with a recess 31a that is curved to follow the outer periphery of the drive rotating shaft EMb.

[0056] An arc-shaped portion ASP is formed on the outer peripheral edge of the first link member 31 when it is wound up. This arc-shaped portion ASP constitutes part of the circumference when it rotates around the drive rotation shaft EMb, and a regulating roller 105a formed on the bearing member 105 rolls on this arc-shaped portion ASP. The regulating roller 105a is brought into rolling contact with the first link member 31, thereby guiding the first link member 31 so that it rotates smoothly.

[0057] An arm AM extending linearly is formed on the side of the first link member 31 facing the second link member 32, and an upper connecting hole (not shown) is provided at the tip of the arm AM, as shown in Figure 1. A connecting hole (not shown) is provided at the end of the second link member 32, which will be described later, facing the first link member 31. A second connecting part SCP is formed by the upper connecting hole at the tip of the arm AM, the connecting hole at the end of the second link member 32 facing the first link member 31, and the pivot pin AP that communicates with these upper connecting holes and the connecting holes.

[0058] The arm AM of the first link member 31 has a central portion provided with latching portions LEP protruding along the Y-axis direction on both sides of the plate material. The latching portions LEP are formed in a rectangular column shape. When the rotating arm 30 rotates, for example, 180 degrees from the initial position, the latching portions LEP come into contact with the latching portions LP, as shown in FIG. 6, and the first link member 31 itself begins to rotate around the drive rotation shaft EMb. The rotation radius of the first link member 31 is a length L3 from the center of the drive rotation shaft EMb to the center of the second connecting portion SCP (see FIG. 6). This L3 is the length L1 minus the length L2 from the center of the first connecting portion FCP to the center of the second connecting portion SCP (see FIGS. 1 and 6). The first link member 31 corresponds to the second mechanism.

[0059] (Second Link Member) As shown in FIGS. 1 and 4, the second link member 32 is integrally formed by connecting two plate materials BM bent into a boomerang shape with a short cylindrical connecting member CM.

[0060] A connecting hole (not shown) is formed at each upper end of the second link member 32. A third connecting part TCP is formed by connecting holes (not shown) formed at the force point PF of the arm member 4 and the pivot pin AP communicating with these connecting holes. A ball bearing is provided in the connecting hole formed at the force point PF of the arm member 4, and the arm member 4 and the second link member 32 are connected so as to be rotatable relative to each other.

[0061] (Arm member) As shown in Figure 1, the arm member 4 in the first embodiment has a point of action PA between a force point PF connected to the second link member 32 and a fulcrum F provided on an axial support member 25 erected on the upper left end surface of the top plate 22 of the support frame 2.

[0062] The arm member 4 is, for example, a single, elongated plate member made of iron, and has a shape in which the width gradually increases from both ends toward a portion in the middle corresponding to the application point PA. By extending laterally, the arm member 4 laterally shifts the force point PF and the fulcrum F from the link member 5 located directly below the application point PA. Therefore, "extending laterally" in this application document means that the arm member 4 is provided so that the force point PF and the fulcrum F provided on the arm member 4 can be positioned away from the link member 5.

[0063] A connecting hole (not shown) is provided in a portion of the arm member 4 corresponding to the force point PF, and a connecting hole (not shown) is provided in a portion of the arm member 4 corresponding to the action point PA. These connecting holes are provided with, for example, ball bearings.

[0064] 5, a rotation shaft 4d integral with the arm member 4 is provided protruding from both sides in the Y-axis direction at the portion corresponding to the fulcrum F. The rotation shaft 4d is composed of a thick shaft portion on the base end side and a thin shaft portion on the tip end side, and the thin shaft portion is supported in a support hole provided in the shaft support member 25 of the top plate 22. A ball bearing is provided in the support hole.

[0065] For example, the arm member 4 is provided with a rotation angle sensor (not shown) that detects the rotation direction, rotation speed, rotation position, etc. and transmits them to the control device.

[0066] (Link Member) The link member 5 connects the application point PA of the arm member 4 with the upper part of the lifting frame 6, and transmits force so that the swinging motion of the arm member 4 becomes the downward motion of the lifting frame 6. As shown in Figure 2, the link member 5 is made up of two opposing elongated rectangular plate-like bodies 5a, which are connected with a gap between them by short cylindrical connecting members 5b provided at three locations, and the two plate-like bodies 5a form an integrated link member 5.

[0067] At the upper end of the link member 5, an upper through-hole 5c is formed through each of the two plate-like bodies 5a, and a pivot pin member SPM passes through the upper through-hole 5c. At the upper end of the link member 5, the end of the arm member 4 on the application point PA side is sandwiched between the two plate-like bodies 5a, and the link member 5 is connected so that it is held between them. At the lower end of the link member 5, a lower through-hole 5d is formed through each of the two plate-like bodies 5a, and a pivot pin member SPM passes through the lower through-hole 5d. At the lower end of the link member 5, the link member 5 is connected so that a connecting portion 63 of the lifting frame 6, which will be described later, is sandwiched between the two plate-like bodies 5a.

[0068] (Lifting Frame) The lifting frame 6 presses against the sand mold portion SM provided in the molding flask CF of the poured mold PM to extract the sand mold portion SM from the molding flask CF. The lifting frame 6 includes a lifting section 61, a pressure plate 62, a connecting section 63, and a guide section 64 (see FIGS. 2 and 6).

[0069] (Elevation Section) The elevation section 61 is formed in a rectangular cylindrical shape with a top, and has partition plates 61a provided inward from parallel walls facing each other in the X-axis and Y-axis directions. The two partition plates 61a intersect in a cross shape. The lower end of the partition plate 61a is formed so that its end face coincides with the lower end of the rectangular cylindrical wall. The partition plate 61a reinforces the pressure plate 62, which will be described later, and prevents the pressure plate 62 from deforming due to pressure during extraction.

[0070] The pressure plate 62 is made of, for example, iron and is formed of a square or rectangular plate material. The pressure plate 62 is formed to have dimensions corresponding to the lower surface of the sand mold portion SM. As shown in FIG. 2, a pair of guide rod connecting portions 61b protruding outward along the Y-axis direction are provided on the upper part of the lifting unit 61, and the lower ends of guide rods 64b of the guide unit 64, which will be described later, are connected to the guide rod connecting portions 61b.

[0071] (Guide Section) The guide section 64 guides the vertical movement of the lift section 61. As shown in Fig. 2, the guide section 64 includes a cylindrical section 64a and a guide rod 64b.

[0072] The cylindrical portions 64a are made of, for example, iron and formed into a cylindrical shape. As described above, they are arranged side by side along the Y-axis direction on both sides of the through-hole 22a formed in the top plate 22. The lower portion of each cylindrical portion 64a is penetrated and fixed to the top plate 22, and a flange portion 64a1 is provided around the outer periphery of the upper portion exposed from the top plate 22. Guide rods 64b are slidably inserted into the cylindrical portions 64a. The guide rods 64b are made of, for example, iron and formed into a rod shape with a circular cross section. Their lower ends are connected to the guide rod connectors 61b. The pair of guide rod connectors 61b are provided on the upper portion of the lifting unit 61 so as to protrude outward in the Y-axis direction. (Upward Force Generating Device) The upward force generating device 8 offsets the downward force applied to the drive force transmission mechanism 3 by the weight of components such as the lifting frame 6, the link member 5, and the guide rod 53 that moves up and down in conjunction with these components.

[0073] As shown in Fig. 2, the upward force generator 8 includes a pulley 81, a weight 82, a wire rope 83, and a guide bar 84. The upward force generator 8 generates an upward force by the gravity of the weight 82 via the pulley 81. As shown in Fig. 3, the pulleys 81 are provided on both sides of the first opening 2c in positions aligned in the Y-axis direction with respect to the first opening 2c of the tabletop 22. The pulley 81 is a fixed pulley that is journaled on a pulley base 811 protruding from the upper surface of the tabletop 22 by a pulley shaft 812 extending in the Y-axis direction.

[0074] As shown in Fig. 3, a wire rope 83 is hung around the outer periphery of the disk-shaped pulley 81. As shown in Fig. 2, the inner end of the wire rope 83 is connected to the pulley rope connecting part 65 provided at the guide rod connecting part 61b of the lifting frame 6, and the outer end of the wire rope 83 is connected to the weight 82 via a bracket. The wire rope 83 is inserted through a hole in the second opening 2d provided in the top plate 22 and hangs down.

[0075] 5, the weight 82 is formed in a rectangular parallelepiped shape, and each of the side surfaces aligned in the X-axis direction has a guide groove 82a recessed therein so as to extend vertically. The guide grooves 82a are provided closer to the lifting frame 6 than the bracket of the weight 82, and protrusions 84a of the guide bars 84 are slidably inserted into the guide grooves 82a.

[0076] The guide bars 84 are formed as long plates with rectangular cross sections on both sides of the weight 82 aligned in the X-axis direction, and have protrusions 84a that protrude toward the weight 82. The guide bars 84 extend vertically, and the lower ends of the guide bars 84 are fixed in a state in which they penetrate the top plate 22. The guide bars 84 suppress wobbling when the weight 82 moves up and down, and guide the weight 82 so that it moves up and down quickly and smoothly.

[0077] (Pulley rope connection part) The lifting frame 6 is provided with a pulley rope connection part 65. As shown in Figure 2, the pulley rope connection part 65 is formed from a plate material with a rectangular cross section that is long in the vertical direction, and is assembled to the tip parts of the two guide rod connection parts 61b. The pulley rope connection part 65 extends in the Y-axis direction, and both ends protrude beyond the lifting part 61. Connection holes are provided at both ends, and the inner ends of the wire ropes 83 are connected to the connection holes as described above.

[0078] (Descent Restriction Device) The descent restriction device 7 supports only the flask CF from below during mold removal, and is used when the sand mold section SM is removed downward from the flask CF by the lifting frame 6. As shown in Figure 1, the descent restriction device 7 of the first embodiment corresponds to the roller conveyor RC of the carry-in / carry-out device IOC, which performs the two functions of transporting the flask CF and restricting the downward movement of the flask CF.

[0079] The roller conveyor RC includes a pair of roller support members RCa extending along the Y-axis direction, and a plurality of rollers RCb arranged side by side along the Y-axis direction inside the roller support members RCa.

[0080] The roller conveyor RC carries the poured mold PM (with flask) to the removal position and carries the flask CF from which the mold (sand mold portion SM) has been removed for reuse. Each roller RCb is formed in a disk shape and has a short cylindrical mounting portion and a flange portion. Each roller RCb is rotatably supported on a rotation shaft extending in the X-axis direction provided on the roller support member RCa. At the position where extrusion occurs, a vibrating conveyor VC is provided below the roller conveyor RC.

[0081] (Vibration Conveyor) The vibration conveyor VC extends along the X-axis direction and vibrates the casting CT and molding sand contained in the extracted sand mold portion SM so that they separate. The vibration conveyor VC is a well-known technique, so a description thereof will be omitted.

[0082] (Operation) The operation of the poured mold extractor 1 configured as described above will be described below with reference to Figures 1, 6, and 7. First, in the initial position, as shown in Figure 1, the first connecting part FCP of the rotating arm 30 is located directly above the drive rotation shaft EMb. As a result, the first link member 31 and the second link member 32 are extended upward in a straight line.

[0083] 1, and holds the lifting frame 6 at its raised end via a link member 5. The pressure plate 62 of the lifting frame 6 faces, with a gap between them, the upper surface of the sand mold portion SM of the poured mold PM that has been carried into the position where the extraction operation will be performed.

[0084] Next, the control device drives the electric motor EM to rotate the rotating arm 30 clockwise 180 degrees, as shown in Figure 6, and move the first connecting part FCP to directly below the drive rotation axis EMb (shifting process). From the initial position to 180 degrees, the first connecting part FCP moves with a rotation radius equal to the distance L1 between the drive rotation axis EMb of the rotating arm 30 and the first connecting part FCP. At that time, the force point PF descends a distance approximately twice L1.

[0085] During this descent, the upward force generator 8 prevents the descent speed of the lifting frame 6 from becoming faster than the rotation speed of the drive rotation shaft EMb. The sand portion SM of the poured mold PM is separated from the molding flask CF and shifted, completing the initial process.

[0086] Next, as shown in Figure 7, the control device further rotates the rotating arm 30 clockwise from the initial position to a position of 360 degrees. From 180 degrees to 360 degrees, the force point PF descends as the second connecting portion SFC rotates with a rotation radius of L3 (movement process). L3 is the distance between the second connecting portion SFC and the first connecting portion FFC minus L1 from L2.

[0087] Since L3 is a longer distance than L1, the force point PF moves down a long distance at a high speed. Since the torque of the electric motor EM is constant, the load applied to the force point PF is smaller than when rotating 180 degrees from the initial position.

[0088] When the sand mold section SM is removed from the molding flask CF, the casting CT contained in the sand mold section SM falls onto the vibrating conveyor VC, where it is vibrated to separate the casting CT from the sand and transport it to the mold break-up process. In this way, the removal work can be performed in accordance with the initial process (shifting process), which requires a large force, and the removal completion process (moving process), which requires a high speed, without any special control of the electric motor EM.

[0089] As is clear from the above description, the poured mold removal device 1 comprises: an electric motor EM; a lifting frame 6 that can raise and lower the device by pressing against the top surface of the sand mold portion SM that is inside the molding flask CF of the poured mold PM; and an arm member 4 that extends laterally and has a fulcrum F that serves as the center of rotation, a force point PF to which the driving force of the electric motor EM is applied, and an action point PA that rotates based on the driving force applied to the force point PF, the action point PA being located above the lifting frame 6 and at least the force point PF being located at a position away from the top of the lifting frame 6, and that swings within an imaginary vertical plane.

[0090] The lifting frame 6 is provided with a drive force transmission mechanism 3 disposed between the electric motor EM and the force point PF of the arm member 4, a link member 5 extending vertically above the lifting frame 6 and connecting the force point PA of the arm member 4 to the lifting frame 6, and a descent restriction device 7 which abuts against the outer periphery of the flask CF when the lifting frame 6 descends to restrict the descent of the flask CF.

[0091] This allows the area around the force point PF, which includes the main mechanical components, to be located away from the position directly above where the mold (sand mold portion SM) is pushed out, thereby eliminating the problem of limited installation space. Furthermore, because the arm member 4 is configured to operate on the principle of leverage, a small-torque electric motor EM can be used at the force point PF, making it possible to select an inexpensive electric motor EM, thereby reducing equipment costs and running costs during use.

[0092] In the poured mold removal device 1 of the first embodiment, the drive force transmission mechanism 3 includes a first mechanism (rotating arm 30) that generates the force required to shift the sand mold section SM formed within the molding flask CF downward from the molding flask CF, and a second mechanism (first link member 31) that moves the sand mold section SM shifted by the first mechanism (rotating arm 30) further downward.

[0093] The force generated by the first mechanism (rotating arm 30) to shift the mold portion SM is greater than the force generated by the second mechanism (first link member 31) to move the mold portion SM downward, and the speed at which the sand mold portion SM is moved downward by the second mechanism (first link member 31) is greater than the speed at which the sand mold portion SM is shifted by the first mechanism (rotating arm 30).

[0094] In this way, when a large force is required in the removal operation, the first mechanism (rotating arm 30) is activated, and when a high speed is required, the second mechanism (first link member 31) is activated. In this way, the operation corresponding to the removal operation of the poured mold can be realized without special control of the electric motor EM.

[0095] In this way, the high load region where the motor is lowered at a slow speed and the low load region where the motor is lowered at a high speed can be made to function efficiently according to the load required to remove the mold (sand mold portion SM) without changing the output of the electric motor EM itself, which is the driving source.

[0096] The first mechanism also includes a rotating arm 30 whose tip rotates at a predetermined radius when driven by the electric motor EM, and the second mechanism includes a first link member 31 whose base end is connected to the tip of the rotating arm 30 and which is wound around the rotating arm 30 so that its tip rotates at a radius larger than the radius of rotation of the rotating arm 30.

[0097] According to this, the high load range where the lift is performed at a low speed is achieved by rotating the rotary arm 30 and winding up the first link member 31. The low load range where the lift is performed at a high speed can be achieved by winding up the force point PF of the arm member 4 with the first link member 31, which is wound around the rotary arm 30 and has a tip end with a larger radius of rotation than the rotary arm 30.

[0098] In addition, the poured mold removal device 1 of the first embodiment is equipped with an upward force generating device 8 that generates an upward force that reduces the downward force generated at the application point PA of the arm member 4 by the weight of the lifting frame 6 and the link member 5.

[0099] If the weight of the components including the lifting frame 6 and the link members 5 generates a large downward force, the speed at which the lifting frame 6 descends may become faster than the rotational speed of the drive shaft EMb during the process of lowering the poured mold PM. In such a case, the operation of the drive mechanism may be impaired.

[0100] Specifically, the rotating arm 30 , the first link member 31 and the second link member 32 are smoothly wound up in a linearly stretched state by the rotation of the rotating arm 30 .

[0101] However, if the descending speed of the lifting frame 6 becomes faster than the rotation of the rotating arm 30, the linearly extended state cannot be maintained, and bending occurs due to slack between the rotating arm 30 and the first link member 31, and between the first link member 31 and the second link member 32, hindering smooth winding operation.

[0102] The upward force generating device 8 prevents the descending speed of the lifting frame 6 from becoming faster than the rotation speed of the rotating arm 30, thereby realizing a smooth winding operation.

[0103] Furthermore, the upward force generating device 8 generates an upward force by the gravity of the weight 82 via the pulley 81 .

[0104] This makes it possible to reduce the downward force that affects the operation of the driving force transmission mechanism 3 using a simple mechanism that uses the gravity of the weight 82, without providing a dedicated device for generating driving force.

[0105] Furthermore, in the poured mold extractor, the rotating arm 30, arm member 4, and link member 5 are configured to rotate or swing on the same imaginary plane (a vertical plane in this embodiment), which allows the rotating arm, arm member, and link member to be arranged compactly, thereby saving space.

[0106] Second Embodiment Next, a second embodiment of the poured mold removal apparatus will be described below with reference to Figures 8 and 9. In the second embodiment, the poured mold removal apparatus 201 is provided with a receiving portion RP on the support frame 202, and the structure of the drive force transmission mechanism 203 is different. The arm member 204 is structurally different in that it has two points that can serve as fulcrums F. The lifting frame 206 is structurally different. The above points are the differences from the first embodiment, but the rest of the configuration is the same, so further description will be omitted.

[0107] The support frame 202 supports the electric motor EM, the receiving part RP, the loading / unloading device IOC (roller conveyor RC), etc. The support frame 202 is assembled into a rectangular parallelepiped shape that is long in the X-axis direction by six lower support columns 2021, upper support columns 2022 that are provided continuously with the lower support columns 2021, and a plurality of vertical and horizontal bars in a plan view.

[0108] A shelf 202a is provided in the middle of the right side in Fig. 8, and two electric motors EM are installed on the shelf 202a with their output shafts facing each other. A roller support member RCa of the loading / unloading device IOC extending in the Y-axis direction is disposed in the middle of the left side in Fig. 8.

[0109] A rectangular top plate 202b extending along the Y-axis direction is supported by a not-shown top support column at the upper end of the support frame 202. As shown in Fig. 8, the top plate 202b is provided with a first receiving portion RP1 and a second receiving portion RP2 that protrude downward and receive a first roller RL1 and a second roller RL2, respectively, which will be described later.

[0110] (Receiving portion) The receiving portion RP has a first receiving portion RP1 and a second receiving portion RP2. The first receiving portion RP1 and the second receiving portion RP2 are formed from a pair of rectangular plate members. The first receiving portion RP1 and the second receiving portion RP2 are plate members that protrude downward from the top plate 202b, and as shown in FIG. 8, a half-moon-shaped recess RPa is formed in the lower portion of each of the first receiving portion RP1 and the second receiving portion RP2.

[0111] A first roller RL1 and a second roller RL2, which will be described later, are detachably supported in these half-moon shaped recesses RPa.

[0112] (Driving Force Transmission Mechanism) The driving force transmission mechanism 203 includes a rotating arm 2030 and a connecting link member 2031. The rotating arm 2030 is connected to a driving rotation shaft EMb connected to the output shafts of the two electric motors EM so as not to rotate relative to the driving rotation shaft EMb.

[0113] (Rotating Arm) In the second embodiment, the rotating arm 2030 is made of, for example, iron and is formed of two long plate-like members that gradually become thinner toward the tip. A connecting hole (not shown) that forms part of the first connecting part TFCP is formed at the tip, and the rotating arm 2030 is connected to the connecting link member 2031 at the first connecting part TFCP.

[0114] (Connecting Link Member) The connecting link member 2031 is made of, for example, iron and is formed from a single boomerang-shaped plate material with a bent middle portion. As shown in Fig. 8, a lower connecting hole is formed at the end of the connecting link member 2031 on the rotating arm 2030 side, and this lower connecting hole is connected to a connecting hole (not shown) of the rotating arm 2030 by a pivot pin AP to form a first connecting part TFCP.

[0115] The reason for bending the middle portion of the connecting link member 2031 is to prevent the middle portion of the connecting link member 2031 from coming into contact with the drive rotation shaft EMb when the rotating arm 2030 is positioned at the upper end vertical position.

[0116] The rotating arm 2030 and the connecting link member 2031 are connected to each other so as to be rotatable within a virtual vertical plane in which the rotating arm 2030 rotates. An upper connecting hole (not shown) is provided at the end of the connecting link member 2031 on the arm member 204 side, and forms part of the second connecting part TSCP.

[0117] (Arm Member) The arm member 204 in the second embodiment is made of, for example, iron, and the main body portion on the link member 5 side is formed from a single long plate material. The end portion on the side of the force point PF described below is made of two short plate materials that are bonded together by, for example, welding so that the base ends are sandwiched between the main body portion.

[0118] A connecting hole (not shown) is provided at the tip of the arm member 204 on the connecting link member 2031 side, and a pivot pin AP that communicates with an upper connecting hole of the connecting link member 2031, which is a single plate material, is inserted to connect the arm member 204 to the link member 2031. The upper connecting hole, the connecting hole, and the pivot pin AP form a second connecting part TSCP. The pivot pin AP inserted into the center of the second connecting part TSCP is set as the force point PF. The pivot pin AP of the connecting part that connects the arm member 204 and the link member 5 is set as the application point PA.

[0119] The arm member 204 is provided with a first roller RL1 (corresponding to the first fulcrum FF) located closer to the load point PA and a second roller RL2 (corresponding to the second fulcrum SF) located closer to the force point PF.

[0120] (Rollers) As described above, the rollers include the first roller RL1 and the second roller RL2. As shown in Fig. 8, the first roller RL1 and the second roller RL2 are each provided with a rotation support shaft RLs (corresponding to a rotation shaft) that penetrates the arm member 204 at a right angle and is fixed so as to extend horizontally. The rotation support shaft RLs is provided so as to be perpendicular to the vertical plane in which the arm member 204 swings.

[0121] The first roller RL1 and the second roller RL2 each include a roller body and a ball bearing portion.

[0122] The pair of roller bodies are formed, for example, in the shape of disks, and are arranged to sandwich the arm member 204 from both sides. A flange portion is provided around the inside of the outer periphery of each disk (on the arm member 204 side). The flange portion restricts lateral movement of the roller RL by the inside of the contact point of the receiving portion RP abutting against the flange portion.

[0123] The disc-shaped roller body has a fitting hole at its center into which the rotation support shaft RLs is fitted, and a ball bearing is installed in the fitting hole. The rotation support shafts RLs provided on the first roller RL1 and the second roller RL2 can be considered as the first fulcrum FF and the second fulcrum SF. However, in this specification, the roller bodies and rotation support shafts RLs of the first roller RL1 and the second roller RL2 are considered to be supported as a whole, including the roller bodies and rotation support shafts RLs, so that a force is generated based on the principle of a lever, and the first roller RL1 is designated as the first fulcrum FF and the second roller RL2 is designated as the second fulcrum SF.

[0124] 8 and 9, the roller guide RG is formed of two rectangular iron plates, each of which has an opening OH through which the outer periphery of the first roller RL1 is inserted to move along an arc-shaped track. The second roller RL2 is supported by the receiving portion RP, and when the effective fulcrum F switches from the first roller RL1 to the second roller RL2, the roller guide RG guides the first roller RL1 to move downward along the track.

[0125] 2 can be used as the upward force generating device 8. The upward force generating device 8 cancels out the downward force generated by the weight of parts such as the lifting frame 206, the link member 5, and a guide rod (not shown) that moves up and down in conjunction with these.

[0126] Furthermore, when the first roller RL1 or the second roller RL2 functions as an effective fulcrum F, the weight of the weight 82 is set so that an upward pressing force is generated to prevent the first roller RL1 from coming off the first receiving portion RP1 and the second roller RL2 from coming off the second receiving portion RP2.

[0127] 8, the lifting frame 206 in the second embodiment includes an extraction plate 2062 and a support plate 2063. The extraction plate 2062 is formed, for example, from a rectangular iron plate, and is adapted to abut against the upper surface of the sand mold portion SM formed inside the molding flask CF.

[0128] The upper surface of the extraction plate 2062 is supported by a support plate 2063. The support plate 2063 is made of, for example, iron and formed into a thick rectangular plate. The support plate 2063 prevents the extraction plate 2062 from being deformed by the force applied to the extraction plate 2062 when the mold (sand mold portion SM) is shifted and removed downward from the molding flask CF, thereby enabling smooth shifting and downward removal operations.

[0129] (Operation) The operation of the poured mold extractor 201 configured as described above will be described below with reference to Figures 8 and 9. In its initial position, the rotating arm 2030 is positioned vertically below the drive rotation shaft EMb. The connecting link member 2031 extends upward from the tip of the rotating arm 2030, pulling down the force point PF of the arm member 204.

[0130] This position is the counterclockwise rotation end of the arm member 204. The first fulcrum FF of the arm member 204 is received by the receiving portion RP and serves as an effective fulcrum F. The point of application PA and the lifting frame 206 are at the upper end position.

[0131] The poured mold PM (SM / CF) is carried by the roller conveyor RC to the position where the extraction work is performed. The extraction plate 2062 of the lifting frame 6 faces the upper surface of the sand mold portion SM with a gap therebetween.

[0132] Next, as shown in FIG. 9, the control device rotates the rotary arm 2030 clockwise by 180 degrees and positions it vertically above the drive rotation shaft EMb.

[0133] The force point PF rises, and the arm member 204 switches the effective fulcrum F from the first fulcrum FF to the second fulcrum SF during rotation, causing the point of application PA to rotate counterclockwise. Since the radius of rotation is longer when the second fulcrum SF is the effective fulcrum F than when the first fulcrum FF is the effective fulcrum F, the point of application PA and the lifting frame 6 move by a large distance and quickly.

[0134] In this way, in the early stage of the extraction work (shifting process), by setting the effective fulcrum F as the first fulcrum FF, a strong force can be exerted over a short moving distance. Then, in the later stage of the extraction work (moving process), by setting the effective fulcrum F as the second fulcrum SF, a state in which the force is small but the moving distance is long and fast can be achieved.

[0135] As is clear from the above description, in the poured mold removal device 201 of the second embodiment, the arm member 204 has a fulcrum F that is located between the force point PF and the action point PA, and the fulcrum F has two fulcrums: a first fulcrum FF and a second fulcrum SF that is located closer to the force point PF than the first fulcrum FF. The first fulcrum FF is used when shifting the sand mold portion SM formed in the molding flask CF downward from the molding flask CF, and the second fulcrum SF is used in place of the first fulcrum FF when moving the shifted sand mold portion SM further downward.

[0136] According to this, when the first fulcrum FF is used in the arm member 204, the point of application PA is closer and the point of force PF is farther away compared to the second fulcrum SF, so that, according to the principle of leverage, a large force is likely to be generated at the point of application PA, even though the travel distance is short. When the second fulcrum SF is used, a large force is unlikely to be generated at the point of application PA, but a large travel distance can be ensured, and the downward movement speed can be increased.

[0137] Furthermore, according to the poured mold removal device 201, the first fulcrum FF and the second fulcrum SF are provided with a roller RL having a rotation axis (rotation support axis RLs) extending along a direction perpendicular to the vertical plane in which the arm member 204 swings, and a receiving part RP having a crescent-shaped recess RPa corresponding to the outer periphery of the roller RL, and which removably supports the outer periphery of the roller RL in the vertical direction by the crescent-shaped recess RPa.

[0138] With this, the freely rotating roller RL and the receiving portion RP corresponding to the shape of the roller RL prevent the center of rotation of the arm member 204 from becoming misaligned even when the first fulcrum FF and the second fulcrum SF each serve as an effective fulcrum F. This makes it possible to easily and smoothly switch between the first fulcrum FF and the second fulcrum SF, which are in a state where no misalignment occurs.

[0139] Further, a roller guide RG is provided at the first support point FF to guide the path of movement of the roller RL that has come off the receiving portion RP.

[0140] According to this, when the effective fulcrum F switches to the second fulcrum SF, the first roller RL1, which was the first fulcrum FF, moves away from the receiving part RP, but the trajectory of movement is regulated by the roller guide RG, so that stable and safe movement can be achieved.

[0141] Although the upward force generating device 8 is configured by the weight 82 via the pulley 81 in the above embodiment, it is not limited to this. For example, a counterbalance valve may be used. The counterbalance valve uses a hydraulic cylinder to receive the back pressure generated by the weight of the parts including the lifting frame, thereby preventing the lifting frame from falling.

[0142] The present invention is not limited to the above-described embodiments shown in the drawings, but can be modified appropriately within the scope of the present invention.

[0143] 1: poured mold removal device, 3: driving force transmission mechanism, 31: first link member (driving force transmission mechanism), 32: second link member (driving force transmission mechanism), 4: arm member, 5: link member, 6: lifting frame, 62: pressure plate, 7: descent restriction device, 8: upward force generator, 81: pulley, 82: weight, 83: wire rope, 201: poured mold removal device, 203: driving force transmission mechanism, 2030: rotating arm (driving force transmission mechanism), 2031: connecting link member (driving force transmission mechanism) structure), 204: arm member, 206: lifting frame, 2062: extraction plate, CF: molding flask, EM: electric motor, EMa: output shaft, EMb: drive rotation shaft, F: fulcrum, FF: first fulcrum, SF: second fulcrum, PA: point of action, PF: force point, PM: poured mold, RC: roller conveyor (descent restriction device), RP: receiving part, RP1: first receiving part, RP2: second receiving part, RL: roller, RL1: first roller, RL2: second roller, RLs: rotation support shaft (rotation shaft), SM: sand mold part.

Claims

1. A poured mold removal device comprising: an electric motor; a lifting frame that presses against the top surface of the sand mold portion that is inside the flask of the poured mold, thereby enabling it to be lowered; an arm member that extends laterally and has a fulcrum that serves as the center of rotation, a force point to which the driving force of the electric motor is applied, and a point of action that rotates based on the driving force applied to the force point, the arm member having the force point located above the lifting frame and at least the force point located in a position away from the top of the lifting frame, so that the arm member swings within an imaginary vertical plane; a drive force transmission mechanism provided between the electric motor and the force point of the arm member; a link member that extends vertically above the lifting frame and connects the force point of the arm member to the lifting frame; and a descent restriction device that abuts against the flask when the lifting frame is lowered, thereby restricting the descent of the flask.

2. The device according to claim 1, wherein the drive force transmission mechanism comprises a first mechanism that generates a force necessary to displace the sand mold portion formed in the molding flask downward from the molding flask, and a second mechanism that moves the sand mold portion displaced by the first mechanism further downward, the force generated by the first mechanism for displacement is greater than the force generated by the second mechanism for downward movement, and the speed at which the sand mold portion is moved downward by the second mechanism is faster than the speed at which it is displaced by the first mechanism.

3. The device described in claim 2, wherein the first mechanism comprises a rotating arm whose tip rotates at a predetermined radius when driven by the electric motor, and the second mechanism comprises a first link member whose base end is connected to the tip of the rotating arm and which is wound around the rotating arm so that its tip rotates at a radius larger than the radius of rotation of the rotating arm.

4. The device described in claim 1, wherein the arm member has a fulcrum that is provided between the force point and the point of action, the fulcrum having two fulcrums: a first fulcrum and a second fulcrum that is positioned closer to the force point than the first fulcrum, the first fulcrum being used when shifting the sand mold portion formed in the molding flask downward from the molding flask, and the second fulcrum being used in place of the first fulcrum when moving the shifted sand mold portion further downward.

5. The device according to claim 4, wherein the first and second fulcrums are provided with rollers having rotation axes extending in a direction perpendicular to the vertical plane in which the arm members swing, and receiving parts each having a crescent-shaped recess corresponding to the outer periphery of the roller, the crescent-shaped recess removably supporting the outer periphery of the roller in the vertical direction.

6. The device according to claim 5, wherein a roller guide is provided at the first fulcrum to guide the path of movement of the roller that has come off the receiving portion.

7. The apparatus according to claim 1, further comprising an upward force generating device that generates an upward force that reduces the downward force generated at the application point of the arm member by the weight of the lifting frame and the link member.

8. The device according to claim 7, wherein the upward force generating device generates an upward force by the gravity of a weight via a pulley.

9. The apparatus of claim 3, wherein said rotating arm, said arm member and said link member move in the same plane.

10. A method for removing a poured mold using the poured mold removal device of claim 1, comprising: a shifting step in which the driving force of the electric motor is transmitted to the lifting frame via the driving force transmission mechanism and the arm member, thereby relatively shifting the sand mold portion in the vertical direction to remove it from the molding flask; and a downward movement step in which the sand mold portion shifted in the shifting step is moved downward with a force smaller than that used in the shifting step and at a speed greater than that used in the shifting step.

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