Mold molder and mold molder method

Abstract

The invention provides a casting mold molding device and a casting mold molding method, which can reduce the driving force required for rising an extrusion table and realize large energy conservation. The present invention is a casting mold molding machine for molding a casting mold by compressing casting sand filled in a casting frame, the casting mold molding machine being provided with: a pressure application unit that comes into contact with the casting sand; an extrusion table which is provided so as to face the pressure application unit and on which a carrier plate on which the casting frame overlaps is mounted; and a pressurization driving device which is provided above the pressurization implementation unit, and which causes the pressurization implementation unit to approach the extrusion table to compress the casting sand filled in the casting frame, the extrusion table being provided with: an extrusion table raising / lowering device which raises the extrusion table from the standby position to a compression start position above the standby position; and a descending restricting device for restricting the descending of the pressing table against the pressing force during compression by the pressing driving device in the pressing table which is lifted to the compression starting position.

Description

Technical Field

[0001] The present invention relates to a molding machine using a mold of foundry sand and a mold molding method for using the molding machine. Background Art

[0002] As shown in Patent Document 1, there are described a foundry sand filling device for filling a casting frame with foundry sand and a mold forming machine for compressing the foundry sand in the casting frame.

[0003] The foundry sand filling device disclosed in Patent Document 1 is an excellent method for improving filling performance by allowing foundry sand to naturally fall from just above a mold placed at the bottom of a mold forming space, and is therefore currently widely used.

[0004] Prior art literature

[0005] Non-patent literature

[0006] Patent Document 1: Japanese Patent No. 5596986 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, according to Patent Document 1, when the extrusion table is raised at the molding position (extrusion position), the rising distance of the extrusion table is the sum of the rise to the position where the upper end contacts the pressing portion (pressurization implementation portion) after filling with foundry sand (foundry sand filling position, compression start position) and the subsequent extrusion rise, and these are raised by a single cylinder. The power of the extrusion cylinder is equivalent to the foundry sand pressure, but the rise to the aforementioned foundry sand filling position is only the weight of the table and the carrier plate, which is significantly smaller than the foundry sand pressure. Therefore, when rising to the position where the foundry sand contacts the pressing portion, excessive driving force is used to achieve the rise, and energy is wasted during the rise, so further improvements are desired.

[0009] The present invention has been completed in view of the above-mentioned existing problems, and its purpose is to provide the following casting mold machine and casting mold method: since the driving force required for raising the extrusion table is reduced to the amount required to overcome the weight of the extrusion table and the carrier plate, no large driving force for extrusion is generated, thereby achieving significant energy saving.

[0010] Means used to solve problems

[0011] According to a first aspect of the present invention, a mold-making machine is a mold-making machine for compressing foundry sand filled in a casting frame to form a mold, wherein the mold-making machine includes: a pressurizing portion that contacts the foundry sand; a pressing table that is provided opposite to the pressurizing portion and on which a carrier plate on which the casting frame overlaps is placed; and a pressurizing drive device that is provided above the pressurizing portion and compresses the foundry sand filled in the casting frame by bringing the pressurizing portion close to the pressing table.

[0012] The extrusion table is provided with: an extrusion table lifting device which raises the extrusion table from a standby position to a compression start position above the standby position; and a descent limiting device which limits the descent of the extrusion table by overcoming the pressing force during compression by the pressurizing drive device when the extrusion table is raised to the compression start position.

[0013] Thus, the pressing table and carrier plate can be raised to the compression start position using a small driving force. When high-force compression is required, the descent limiting device can overcome the compression force of the pressurizing drive device. Since the pressing table and carrier plate can be raised to the compression start position using a small driving force instead of a large one, power waste can be reduced, thereby lowering running costs.

[0014] According to the second aspect of the present invention, in addition to the first aspect of the casting mold machine, the pressurizing portion is provided separately from the pressurizing drive device and is movable between a retreat position away from the pressurizing drive device and a squeezing position where the pressurizing portion can be squeezed by pressurizing the pressurizing drive device.

[0015] As a result, the pressurization applying portion, which is a moving portion, is separated from the pressurization driving device and thus becomes compact, thereby enabling miniaturization of the driving device for movement and saving of the space required for movement.

[0016] According to the third aspect of the present invention, in addition to the casting mold machine of the first aspect or the second aspect, the descent limiting device includes a support member that is detachably provided below the extrusion stage that has risen to the compression start position to limit the descent of the extrusion stage.

[0017] Thus, with the simple structure of the support member provided below the pressing stage, it is possible to restrain the pressing stage from descending while overcoming the large pressing force acting during pressing.

[0018] According to a fourth aspect of the present invention, in addition to the third aspect of the casting mold machine, the support member is provided with a biasing portion that biases the support member in a direction toward the extrusion stage.

[0019] Thus, the force-applying portion creates a gap at the lower end of the support member. This allows the support member to be easily inserted under the pressing table. Furthermore, the force-applying portion can be compressed by the pressure applied during pressing, eliminating the gap at the lower end and ensuring a tight fit.

[0020] According to the fifth aspect of the present invention, in addition to the first aspect of the casting mold machine, a pressure transmission portion is provided between the pressurizing portion and the pressurizing drive device, and a retraction device that can retract according to the distance between the pressurizing portion and the pressurizing drive device or the pressurizing force is provided on the pressurizing force transmission portion.

[0021] Thus, even if the extrusion stroke height fluctuates when the foundry sand is pressurized, it is possible to pressurize at a predetermined pressure. In addition, it is possible to absorb the overload on the pressurizing drive device generated during extrusion.

[0022] According to a sixth aspect of the present invention, a mold making method is a mold making method using a mold making machine that compresses the casting sand filled in the casting frame to form the mold, the mold making machine comprising: a pressurizing portion that contacts the casting sand; a pressing table that is provided opposite to the pressurizing portion and on which a carrier plate on which the casting frame overlaps is arranged; and a pressurizing drive device that is provided above the pressurizing portion and compresses the casting sand filled in the casting frame by bringing the pressurizing portion close to the pressing table.

[0023] Furthermore, the mold forming method comprises: an extrusion table raising step, in which the extrusion table is raised from a standby position to a compression starting position above the standby position; and an extrusion table descent limiting step, in which, in the extrusion table raised to the compression starting position, the descent of the extrusion table is limited by overcoming the pressing force during compression by the pressurizing drive device.

[0024] Thus, the pressing table and carrier plate can be raised to the compression start position using a small driving force. When a large compression force is required, the descent limiting device can overcome the compression force of the pressurizing drive device. This allows the pressing table and carrier plate to be raised to the compression start position using a small driving force instead of a large one, thus reducing power waste and running costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram showing an embodiment of a mold making device using the mold making machine of the present invention, as seen from the front.

[0026] Figure 2 yes Figure 1 AA section view in.

[0027] Figure 3 This is a diagram showing a state where the extrusion stage is raised to the extrusion start position and the foundry sand filling unit is positioned at the extrusion position.

[0028] Figure 4 yes Figure 3 EE cross-sectional view in.

[0029] Figure 5 This figure shows a state where a support member is fitted under the raised pressing table and foundry sand is put into the mold forming space.

[0030] Figure 6 yes Figure 5 FF cross-sectional view in.

[0031] Figure 7 This is a diagram showing a state where the pressurizing unit is positioned at the pressing position.

[0032] Figure 8 This figure shows a state in which the pressurizing applying portion is pressurized by driving the pressurizing driving device and the mold surface and back surface pressurization are performed.

[0033] Figure 9 This figure shows a state in which the pressurizing drive device is raised and the supporting member is removed from below the pressing stage.

[0034] Figure 10 This is a diagram showing a state in which the pressurizing portion is raised to release the mold.

[0035] Figure 11 This figure shows a state in which the extrusion table is lowered and the upper sand filling frame, the casting frame, and the lower sand filling frame are disassembled.

[0036] Figure 12 This is an enlarged view showing a portion of the descent restricting device in cross section.

[0037] Figure 13 yes Figure 1 BB cross-section view in.

[0038] Figure 14 yes Figure 1 CC section view in.

[0039] Figure 15 It means in Figure 14 A cross-sectional view showing a state in which the support member is embedded under the extrusion stage.

[0040] Figure 16 yes Figure 2 DD cross-sectional view in.

[0041] Figure 17 This is a front schematic diagram showing another example of a mold molding machine. DETAILED DESCRIPTION

[0042] (Implementation Method)

[0043] The following is based on Figures 1 to 16 An embodiment of a mold making apparatus 1 using a mold making machine 5 according to the present invention will be described.

[0044] like Figure 1 As shown, the mold making apparatus 1 in the embodiment includes a carrier plate replacing device 2 , a casting frame carrying-in device 3 , a mold carrying-out device 4 , and a mold making machine 5 .

[0045] In addition, Figure 1 In the diagram, the horizontal direction extending from side to side is the X direction, and the horizontal direction perpendicular to the X direction is the Y direction. When there is an object being transported, consider the imaginary center line along the transport direction, with the side closer to the center line being the "inside" and the side farther away being the "outside."

[0046] In addition, in the conveyance of the casting frame MF, the conveyance starting point side is referred to as the upstream side, and the conveyance end point side is referred to as the downstream side.

[0047] (Carrier board replacement device)

[0048] The carrier plate replacing device 2 replaces the upper mold carrier plate CU and the lower mold carrier plate CD used in the mold molding machine 5 .

[0049] like Figure 14 As shown, the carrier plate exchange device 2 includes: a rotating shaft 21; a shaft support member 22, which is supported by the rotating shaft 21 so as to be rotatable in a horizontal plane; and arm-shaped end holding portions 23, which are parallel to each other and fixed to the two ends of the shaft support member 22. The end holding portions 23 rotate back and forth 180 degrees between the molding position MMP where the mold molding machine 5 is located and the handover position PSP where the carrier plate CU / CD is exchanged (see FIG. Figure 1 ).

[0050] The carrier plate exchanger 2 is a known technology, so detailed description thereof will be omitted. Japanese Patent No. 6577321 is an example of a known technology that describes the carrier plate exchanger 2.

[0051] A casting frame carrying-in device 3 and a casting mold carrying-out device 4 are provided above the molding position MMP of the carrier plate changing device 2 .

[0052] (Casting frame carrying device, casting mold carrying device)

[0053] The casting frame carrying-in device 3 carries the casting frame MF used for molding to the vicinity of the carrying-in / out position IOP located above the molding position MMP.

[0054] The mold unloading device 4 unloads the mold MWF with the casting frame after molding from the loading and unloading position IOP toward the downstream side to the next step.

[0055] The casting frame loading device 3 and the casting mold unloading device 4 are roller conveyors, each comprising a support member 31a extending in the Y direction and a plurality of rollers 31b disposed opposite each other on the inner side of the support member 31a. The loaded casting frame MF is transported by arranging a plurality of them, for example, using a pusher and a buffer device (not shown).

[0056] The casting frame MF carried into the carrying-in / out position IOP is delivered to the mold molding machine 5 .

[0057] (Molding Machine)

[0058] The mold forming machine 5 forms a superimposed frame PMF (see FIG. 1 ) by overlapping the casting frame MF, the lower filling frame ULF, and the upper filling frame OLF on the carrier plate CU / CD. Figure 3 ), the casting sand CS put into the superposition frame PMF is squeezed and compacted to form a casting mold MWF with a casting frame (refer to Figure 11 ).

[0059] like Figure 1 As shown, the mold molding machine 5 includes a pressurizing section 51 and a pressurizing section lifting device 52 (see Figure 2 ), extrusion table 53, extrusion table lifting device 54, descent limiting device 55, pressurizing drive device 59, pressurizing implementation part / casting sand filling part switching device 58.

[0060] (Pressure application part)

[0061] like Figure 1 As shown, the pressurizing unit 51 includes a pressing foot 511 and a lifting frame 512 .

[0062] The pressing foot 511 includes a substantially cubic abutting portion 511a and a rod-shaped rod portion. The abutting portion 511a is arranged in a rectangular shape when viewed from below, and the casting sand CS is pressurized by the lower surface of the abutting portion 511a.

[0063] The lifting frame 512 is made of, for example, iron and formed into a quadrilateral three-dimensional shape. Inside the lifting frame 512 , a plurality of cylinder portions 512 a formed into a cylindrical shape and extending in the vertical direction are arranged in a rectangular shape in a plan view.

[0064] Each cylinder 512a is provided corresponding to a compression foot 511, with the upper end of the rod of the compression foot 511 serving as a piston. The multiple cylinders 512a are connected by a first fluid path FP1, and hydraulic pressure is evenly distributed across all cylinders 512a. The cylinders 512a are connected to the hydraulic pump HP via the first fluid path FP1, with a first solenoid-operated switching valve SSV1 interposed between the cylinders 512a and the hydraulic pump HP.

[0065] The cylinders 512a are filled with hydraulic oil above the pistons. When the compression pin 511 compresses the casting sand CS through its lower end, the pressure is determined by the hydraulic pressure within the cylinders 512a (i.e., the back pressure acting on the pistons). The multiple cylinders 512a are connected to a single hydraulic pump HP via a first fluid path FP1.

[0066] A first pressure sensor PS1 is provided between the cylinder 512a and the first solenoid switching valve SSV1. The first pressure sensor PS1 detects the pressure on the back-pressure side of the cylinder 512a. A branch hydraulic path connected to the first pressure control valve PC1 is provided between the first pressure sensor PS1 and the hydraulic pump HP. The first pressure control valve PC1 operates as a pressure reducing valve that reduces pressure based on a specified pressure value commanded by a connected pressure command amplifier PCA. The operation of the first solenoid switching valve SSV1 is controlled by a control device (not shown).

[0067] (Pressure application part lifting device)

[0068] Although the height position of the pressurizing section 51 is not shown in the figure, the pressurizing section lifting device 52 moves the pressurizing section 51 up and down between a casting sand approach position and a holding position.

[0069] The foundry sand approach position is, for example, a position where the contact portion 511a can approach until just before contact with the upper end surface of the foundry sand CS introduced into the mold shaping space US. The holding position is above the foundry sand approach position and is a position held when the pressurizing unit 51 is laterally moved by, for example, the pressurizing unit / casting sand filling unit switching device 58 described later.

[0070] Since the pressurizing unit lifting device 52 only moves the pressurizing unit 51 up and down, the load force is only the weight of the pressurizing unit 51. In this way, since a large driving force such as that used for pressing is not required, a small and low-cost driving device can be used, which can reduce running costs.

[0071] like Figure 2 As shown, the pressurizing part lifting device 52 includes a support frame 521, a lifting cylinder device 522, and a guide support rod 523 (see Figure 1 ).

[0072] The support frame 521 is installed above a movable base 581 of the pressurizing unit / casting sand filling unit switching device 58 described later. The support frame 521 is made of iron, for example, and is formed into a rectangular frame with an inner side open. The pressurizing unit 51 is supported on the movable base 581 via the support frame 521.

[0073] The front end of a support rod 522a of a cylinder device 522 is connected to the lower surface of the central portion of the support frame 521, which forms a side extending in the X direction. The cylinder portion 522b of the cylinder device 522 is assembled so as to penetrate the moving base 581.

[0074] The lift cylinders 522b are connected to the hydraulic pump via a fluid supply pipe (not shown). An electromagnetic switching valve (not shown) is provided between the lift cylinders 522b and the hydraulic pump, and the operation of the electromagnetic switching valve is controlled by a control device (not shown).

[0075] The upper end of the guide support rod 523 is connected to the lower surface of the central portion of the support frame 521 , which is a side extending in the Y direction.

[0076] The lower end of the guide support rod 523 is connected to the upper surface of the lifting frame 512, and the lower portion of the middle portion is slidably inserted into the support cylinder 523a provided on the moving base 581.

[0077] (Extrusion table)

[0078] The pressing table 53 is used to place the carrier plate CU / CD on which the mold CM and the mold platform MSP are fixed. During pressing, it faces the pressing part 51 and becomes a receiving part of the pressing force. The pressing table 53 is stacked with the carrier plate CU / CD, the casting frame MF, the lower sand filling frame ULF and the upper sand filling frame OLF on top of it to form a superimposed frame PMF (see Figure 3 Then, the casting sand CS is put into the formed superposition frame PMF, and the pressing table 53 and the pressurizing part 51 are relatively close to each other to perform pressing.

[0079] like Figure 2 As shown, the extrusion stage 53 includes an extrusion stage body 531 and a stage support portion 532. The extrusion stage body 531 is made of, for example, iron and has a rectangular thick plate shape.

[0080] like Figure 1 As shown, lower hydraulic cylinders 533 are installed at the four corners of the extrusion stage body 531. The lower hydraulic cylinders 533 have a bottom and a guide hole at the top. A shaft member 533a, which has a flange (piston) at the bottom, is inserted into the guide hole so that it can move up and down. When the shaft member 533a is retracted to the lowest end of the lower hydraulic cylinder 533, the front end of the shaft member 533a is aligned with the upper surface of the extrusion stage body 531.

[0081] The shaft member 533a contacts a support rod member UFM of a lower fill frame ULF described later to raise the upper end of the lower fill frame ULF from the upper surface of the pattern stage MSP, thereby ensuring a lower extrusion amount.

[0082] The lower hydraulic cylinder 533 is connected to a hydraulic pump (not shown) at the upper and lower parts.

[0083] Since the lower hydraulic cylinder 533 and the hydraulic circuit are well-known technologies, detailed description thereof will be omitted. As a document describing these technologies, for example, Japanese Patent No. 5995542 can be cited.

[0084] The stage support portion 532 is made of, for example, iron and is formed into a vertically extending cylindrical shape. The stage support portion 532 is connected to the center of the bottom of the extrusion stage body 531. A support base portion 534 is provided opposite to the lower end of the stage support portion 532.

[0085] The support base portion 534 is made of, for example, iron and formed in a short cylindrical shape, and is fixed to the base BS.

[0086] When the pressing stage 53 is at the rising end (compression start position CSP) (refer to Figure 4 ), between the lower end of the table support portion 532 and the upper end of the support base portion 534, the support member 551 of the descent restriction device 55 described later is detachably embedded (refer to Figure 5 ).

[0087] (Extrusion table lifting device)

[0088] like Figure 4 As shown, the extrusion table lifting device 54 raises and lowers the extrusion table 53 between a standby position SBP located at a lower end and a compression start position CSP located above the standby position SBP.

[0089] When the extrusion table 53 rises, the casting frame MF and the upper filling frame OLF are sequentially overlapped with the lower filling frame ULF set on the carrier plate CU / CD to form a superposition frame PMF, forming a mold shaping space US (refer to Figure 3 ).

[0090] like Figure 1 as well as Figure 2 As shown, the extrusion table lifting device 54 includes a hydraulic cylinder device 541 and a guide device 542 .

[0091] The hydraulic cylinder device 541 is provided in a pair in the Y direction while holding the table support portion 532. The hydraulic cylinder device 541 is provided vertically and includes a hydraulic cylinder portion 541a and a piston portion 541b (see Figure 4 ).

[0092] The hydraulic cylinder 541a is made of, for example, iron and is formed into a bottomed, square tube. The hydraulic cylinders 541a are arranged in pairs, sandwiching the platform support 532. The lower ends of the paired hydraulic cylinders 541a are fixed to the base BS, while the rods of the pistons 541b move vertically through the openings at the upper ends. The distal ends of the rods of the pistons 541b are connected to the bottoms of the respective pressing platforms 53.

[0093] The hydraulic cylinder 541a is connected to a hydraulic pump (not shown) via a fluid supply pipe (not shown). An electromagnetic switching valve (not shown) is provided between the hydraulic cylinder 541a and the hydraulic pump. The operation of the electromagnetic switching valve is controlled by a control device (not shown).

[0094] The guide devices 542 respectively hold two hydraulic cylinder devices 541 and are arranged in parallel along the X direction, and are arranged at four locations in total (see Figure 14 ).

[0095] The guide device 542 guides the pressing table 53 so that it moves up and down in the vertical direction.

[0096] The guide device 542 includes a cylindrical portion 542a and a guide rod portion 542b. The lower end of the cylindrical portion 542a is fixed to the upper surface of the base BS. The guide rod portion 542b is slidably fitted into the cylindrical portion 542a, and the front end is connected to the bottom of the extrusion stage body 531.

[0097] (Supporting member)

[0098] The support member 551 is inserted between the lower end of the table support portion 532 and the upper end of the support base portion 534 provided on the base BS, thereby limiting the descent of the extrusion table 53 (descent limiting device 55). This can overcome the pressure applied by the pressurizing drive device 59, eliminating the need for the extrusion table lifting device 54 to generate a large driving force for raising and lowering the extrusion table 53.

[0099] Therefore, running costs can be significantly reduced.

[0100] like Figure 12 as well as Figure 14 As shown, the support member 551 includes a support member main body 551 a , a cylindrical guide portion 551 b , a coil spring 551 c as a biasing portion, and a sliding mechanism 552 .

[0101] The support member main body 551a is made of, for example, iron and formed in a cylindrical shape, and has a flange portion 551f provided on the outer periphery at a height of about one-third of the entire length from the lower end.

[0102] like Figure 14 As shown, the cylindrical guide portion 551b is made of iron, for example, and is formed into a square cylindrical shape. The support member body 551a is slidably fitted into the through hole of the cylindrical guide portion 551b. Figure 12As shown, in the lower portion of the inner periphery of the cylindrical guide portion 551b, the diameter of the inner peripheral wall is formed to be larger, and a flange portion 551f and a coil spring 551c described later are fitted therein.

[0103] The lower end of the cylindrical guide portion 551b is provided with a through-hole of the same diameter as the upper portion. A compressed coil spring 551c is sandwiched between the bottom wall 551w and the flange 551f around the inner side of the through-hole. The coil spring 551c biases the support member body 551a toward the pressing platform 53 (upward).

[0104] The support member body 551 a is lifted by a predetermined length due to the biasing force of the coil spring 551 c , and the lifted distance creates a gap between the lower end of the support member body 551 a and the upper end of the support base 534 .

[0105] (Sliding mechanism)

[0106] like Figure 13 as well as Figure 14 As shown, the sliding mechanism 552 includes a connecting portion 552a, a sliding rod 552b, a moving guide rail 552c, a rotating wheel 552d, a crank arm 552e, and a groove portion 552f. The sliding mechanism 552 forms a cross-crank sliding mechanism in which the axes of the two sliding pairs intersect at right angles.

[0107] The connecting portion 552a connects the cylindrical guide portion 551b and the sliding rod 552b. The connecting portion 552a is formed into a U-shape when viewed from above, with both ends of the U-shape connected to the opposite side of the rotating shaft 21 of the carrier exchanger 2 relative to the lower portion of the cylindrical guide portion 551b. One end of the sliding rod 552b, described later, is connected to the surface of the connecting portion 552a extending in the Y direction.

[0108] The slide bar 552b is made of, for example, iron and is formed of a long plate extending in the X direction. The slide bar 552b is provided so as to have a rectangular longitudinal cross section with the long sides in the longitudinal direction.

[0109] like Figure 13 As shown, a pair of rotating wheels 552d having a rotation axis extending outward in the Y direction are provided below the cylindrical guide portion 551b. The rotating wheels 552d move in the X direction on a pair of moving rails 552c fixed to a structure not shown.

[0110] The slide bar 552 b is also provided with at least one pair of rotating wheels (not shown), and similarly moves along the X direction on the moving rail 552 c .

[0111] A groove 552f is provided at the other end of the slide rod 552b. The groove 552f is arranged in parallel in the X direction and includes two guide rails 552g extending in the vertical direction.

[0112] A guide roller 552 r is fitted into the groove portion 552 f , and the guide roller 552 r is provided at the front end of a crank arm 552 e rotated by the electric motor 553 .

[0113] The crank arm 552e rotates, causing the guide roller to move up and down relative to the groove portion 552f, and the slide rod 552b to linearly reciprocate along the X direction.

[0114] like Figure 14 as well as Figure 15 As shown, the support member body 551a is reciprocated between a support position SP, where it is embedded between the table support portion 532 and the support base portion 534, and a support preparation position SRP, which is offset from the support position SP, by the sliding mechanism 552. When positioned at the support preparation position SRP, a portion of the lower portion of the table support portion 532 is inserted into the U-shaped space of the connecting portion 552a.

[0115] (Upper sand filling frame holding part)

[0116] The upper filling frame holding portion 56 holds the upper filling frame OLF above the loading / unloading position IOP and the molding position MMP.

[0117] like Figure 1 As shown, the upper filling frame holding portion 56 includes a locking portion 561 , a locking rod 562 , and a locking spring 563 .

[0118] Two pairs of locking portions 561 are arranged in the X direction inside the four pillars of the structure. A plate of a predetermined length is provided protruding inward from the locking portions 561. Each locking portion 561 has a locking hole extending vertically therethrough.

[0119] A locking rod 562 to be described later is slidably inserted into each locking hole.

[0120] The locking rod 562 is made of iron, for example, and is formed into a rod shape. Figure 3 As shown, the locking rod 562 has an upper flange portion 562a at its upper end and a lower flange portion 562b at its lower end. For example, a nut fastened to a male thread portion formed on the locking rod 562 can be used as the lower flange portion 562b.

[0121] A locking spring (coil spring) 563 is provided between the lower flange portion 562b and the sliding support portion OLF2 of the upper sand filling frame OLF (described later). When the upper sand filling frame OLF is positioned above a predetermined height, the locking rod 562 slides in the locking hole of the locking portion 561 and moves upward. When the upper sand filling frame OLF is positioned below a predetermined height, the locking spring 563 applies an upward biasing force to the upper sand filling frame OLF.

[0122] (Upper sand filling frame)

[0123] The upper filling frame OLF is stacked on the casting frame MF to ensure the amount of extrusion when extrusion is performed from the back side of the mold CM. In addition, "extrusion from the back side of the mold (back side extrusion)" refers to the extrusion of the casting sand CS by pressurizing the casting sand CS from above with respect to the casting sand CS injected into the mold forming space US with the mold CM arranged below.

[0124] like Figure 1 as well as Figure 3 As shown, the upper filling frame OLF of this embodiment includes an upper filling frame body OLF1, a sliding support portion OLF2, an upper contact portion OLF3, a lower contact portion OLF4, and a guide wall OLF5.

[0125] The upper sand filling frame body OLF1 is made of, for example, iron and is formed in a short rectangular frame shape.

[0126] The slide support part OLF2 is formed with a flange portion protruding outward from the upper end of the upper sand filling frame body OLF1, and a through support hole OLF6 is formed at the end in the X direction. The through support hole OLF6 is formed so that the periphery of the hole is raised upward.

[0127] The locking rod 562 is slidably inserted into the through-hole OLF6. The locking spring (coil spring) 563 is fitted between the lower flange 562b of the locking rod 562 and the lower outer surface of the through-hole OLF6 of the sliding support part OLF2.

[0128] like Figure 1 As shown, upper contact portions OLF3 are protrudingly provided at four corners of the upper surface of the slide support portion OLF2 at positions facing the lower surfaces of the four corners of the lift frame 512 .

[0129] Lower contact portions OLF4 are protrudingly provided at four corners of the lower surface of the slide support portion OLF2 at positions facing the four corner upper surfaces of the casting frame MF.

[0130] The guide wall OLF5 is fitted externally to the lower end portion of the hopper 571 of the foundry sand filling unit 57 arranged in the X direction to prevent the thrown foundry sand CS from protruding and falling.

[0131] The guide walls OLF5 are formed in pairs at predetermined heights along the vertical direction on both sides of the upper end extending in the Y direction of the upper sand filling frame body OLF1. Figure 2 As shown, the length of the guide wall OLF5 in the Y direction is set to be the same as the length of the end of the slide support portion OLF2. It communicates with a casting sand receiving chute 572 described later.

[0132] Next, the lower fill frame ULF will also be described.

[0133] (Bottom sand filling frame)

[0134] The lower filling frame ULF ensures the extrusion amount from the mold surface side. In addition, "extrusion from the mold surface side (mold surface extrusion)" refers to the extrusion of the casting sand CS injected into the mold shaping space US from the bottom where the mold CM is arranged.

[0135] The lower sand filling frame ULF is made of, for example, iron and formed into a rectangular frame. It is mounted on the upper outer periphery of the carrier plate CU / CD so as to be movable in the vertical direction. Support rod members UFM are mounted at the four corners of the lower sand filling frame ULF so as to protrude downward. Each support rod member UFM faces a shaft member 533a mounted on the pressing table 53.

[0136] When the lower filling frame ULF is at its lowered position relative to the carrier plate CU / CD, its upper end is aligned with the top surface of the pattern platform MSP. The support rod member UFM abuts against the shaft member 533a, pushing it upward. This moves the upper end of the lower filling frame ULF to a position higher than the top surface of the pattern platform MSP, ensuring sufficient extrusion capacity.

[0137] (Filling part for casting sand)

[0138] like Figure 2 as well as Figure 3 As shown, the foundry sand filling unit 57 includes a hopper 571 that stores foundry sand CS required for primary mold formation as a unit, abuts against the upper surface of the upper sand filling frame OLF, and feeds the foundry sand CS into the mold formation space US.

[0139] The hopper 571 has a chute that contacts the upper surface of the upper sand filling frame OLF, and is provided with a plurality of gate plates 571b that partition the interior into upper and lower parts. The area above the gate plates 571b serves as a sand measuring portion for storing the foundry sand CS.

[0140] The foundry sand CS is conveyed by a conveying device (not shown) and stored in a sand measuring unit.

[0141] The gate plates 571b are made of, for example, iron and are formed into flat plates. Multiple gate plates 571b are arranged adjacent to each other. Each gate plate 571b is attached to a horizontal axis passing through the center, with the horizontal axes being parallel to each other within an imaginary plane. Furthermore, each gate plate 571b rotates about the horizontal axis using a rotating device (not shown).

[0142] If the gate 571b is positioned in a horizontal position, the interior of the hopper 571 is partitioned into upper and lower parts, and the foundry sand CS can be retained. If the gate 571b is rotated and positioned in a vertical position, the retained foundry sand CS naturally falls and is injected into the mold forming space US (see Figure 5 ).

[0143] Furthermore, when the lower end of the hopper 571 is moved to switch to the pressurizing unit 51 after the foundry sand CS is introduced into the mold forming space US, the excess foundry sand CS that has protruded upward from the upper sand filling frame OLF is scraped off and dropped into the foundry sand receiving chute 572. The foundry sand CS dropped into the foundry sand receiving chute 572 is transported by a conveyor (not shown) and reused.

[0144] (Pressure application unit / casting sand filling unit switching device)

[0145] The pressurizing section / foundry sand filling section switching device 58 moves one of the pressurizing section 51 and the foundry sand filling section 57 so as to be positioned at the pressing position PP.

[0146] The pressurizing unit / casting sand filling unit switching device 58 includes a movable base 581 (see Figure 2 ), roller conveyor 582 (refer to Figure 1 ), side roller 583 (refer to Figure 1 ), guide groove 584, crank arm 585, electric motor 586 (refer to Figure 16 ).

[0147] The movable base 581 is made of iron and is formed into a rectangular frame shape that is long in the Y direction. Figure 2 As shown, a pressurizing unit 51 is assembled on the left side, and a casting sand filling unit 57 is assembled on the right side. Figure 1 As shown, protrusions 581b are formed at the lower portions of both ends of the moving base 581 in the X direction, and the protrusions 581b extend in the Y direction. These protrusions 581b serve as portions to be placed on a roller conveyor 582 described later.

[0148] As described above, the lifting cylinder 522b of the pressurizing unit lifting device 52 is assembled in a state of passing through the movable base 581 (see Figure 2 ).

[0149] like Figure 1 As shown, the roller conveyor 582 includes a roller support member 582a extending in the Y direction and a plurality of rollers 582b.

[0150] The roller support member 582a is made of, for example, iron and is formed into a strip having a rectangular longitudinal cross-section. It is fixed to the support column of the structure so as to extend along the Y-axis. The plurality of rollers 582b are each formed into a disc shape, and a rotation shaft protruding along the X-axis is rotatably provided inside the paired roller support members 582a.

[0151] Side rollers 583 are arranged in pairs above the roller support member 582a, sandwiching the movable base 581 from both sides in the X direction. Multiple pairs of side rollers 583 are arranged in a row along the Y direction. Each side roller 583 is rotatably supported by a vertically extending rotation axis provided in the structure. The side rollers 583 rotate by contacting the outer side surfaces of the movable base 581 extending in the Y direction, thereby enabling smooth movement of the movable base 581.

[0152] The guide groove 584 is an end portion of the movable base 581 on the side of the casting sand filling portion 57 and is provided at Figure 1 The right end of the . Figure 2 As shown, the guide groove 584 includes a guide post 584a and a pair of guide bars 584b vertically erected on the movable base 581. A guide roller 585a provided at the front end of a crank arm 585 described below is rotatably fitted into the guide groove 584.

[0153] The base end of the crank arm 585 is connected to an electric motor 586 (see FIG. Figure 16 ) is connected to the output shaft of the crank arm 585, and the crank arm 585 is rotated by the drive of the electric motor 586. The electric motor 586 can rotate forward and reverse, and the rotation of the electric motor 586 is controlled by a control device omitted from the figure.

[0154] The pressurizing unit / sand filling unit switching device 58 constitutes a cross slide mechanism, and the movable base 581 moves by rotating the crank arm 585. Thus, either the pressurizing unit 51 or the sand filling unit 57 is switched so that either one faces the pressing position PP.

[0155] (Pressure drive device)

[0156] The pressurizing drive device 59 pressurizes the pressurizing portion 51 from above toward the pressing stage 53 to pressurize the casting sand CS introduced into the mold forming space US.

[0157] The pressurizing drive device 59 includes a swing arm 591 , a drive pinion 592 , a link member 593 , and a sliding member 594 .

[0158] The swing arm 591 includes an arc portion 591a, a pin gear 591b arranged along the arc portion 591a, and an arm portion 591c, whose base end is pivotally supported by a rotating shaft on the structure and is continuous with one end of the arc portion 591a. The swing arm 591 is formed by two opposing plates of the same shape, with the pin gear 591b located on the outer sides of each plate.

[0159] The arc portion 591a is formed by, for example, a circumferential portion corresponding to approximately 50 degrees of a circle having a radius of the arm portion 591c. A driving pinion 592 connected to the output shaft of the electric motor 595 meshes with the pin gear 591b.

[0160] A servo motor, for example, is used as the electric motor 595. The motor's rotational axis is mounted on a support support SS vertically disposed on the upper surface of the top portion TP of the structure, extending in the X direction. The drive pinion 592 is mounted such that its rotational axis extends in the Y direction via a reduction gear (not shown).

[0161] A connecting shaft 591e is provided near the rotation shaft 591d of the arm portion 591c, and one end of the link member 593 is rotatably connected to the connecting shaft 591e. The other end of the link member 593 is connected to the sliding member 594 via the connecting shaft 593e.

[0162] The sliding member 594 is inserted into a slot GV provided through the top TP. The sliding member 594 has a bottomed rectangular cylindrical sliding body 594a and a short cylindrical contact body 594b provided on the bottom lower surface of the sliding body 594a.

[0163] Rollers 594c are arranged in the up-down direction at both ends of the sliding body 594a in the X direction.

[0164] The slot GV is formed in a rectangular shape, and a guide plate GV1 is provided vertically on the inner wall facing the X direction. The roller 594c of the sliding body 594a rotates in contact with the inner wall of the guide plate GV1, guiding the sliding body 594a to move vertically.

[0165] The abutment body 594b abuts against an upper end of a retracting device 60 to be described later.

[0166] (Retraction device)

[0167] The retraction device 60 is installed between the pressurizing unit 51 and the pressurizing drive unit 59. When the foundry sand is pressurized, the extrusion stroke height is slightly changed, so that the pressure required for extrusion can be maintained at the predetermined pressure. It also absorbs any overload on the electric motor 595 that may occur during extrusion.

[0168] The retraction device 60 includes an abutment column 602 and a retraction cylinder 601. The abutment column 602 is made of, for example, iron and is formed into a cylindrical shape, and a flange portion corresponding to a piston is provided at the lower end thereof. The abutment column 602 corresponds to a pressure transmitting portion.

[0169] The retraction cylinder 601 is provided at the center of the upper end of the lifting frame 512. The lower portion of the abutment column 602 is retractably fitted into the upper end opening. The retraction cylinder 601 communicates with the hydraulic pump HP via the second fluid path FP2.

[0170] A second pressure sensor PS2, a second solenoid-operated switching valve SSV2, and a check valve NRV are installed between the retraction cylinder 601 and the hydraulic pump HP. A branch line connected to the relief valve RV is provided in the second fluid path FP2 between the second pressure sensor PS2 and the second solenoid-operated switching valve SSV2. The second pressure sensor PS2 detects back pressure within the retraction cylinder 601, and the relief valve RV reduces overload caused by compression.

[0171] (Control device)

[0172] A control device (not shown) mainly controls the operations of the following devices.

[0173] The electric motor 586 of the pressurizing implementation part / casting sand filling part switching device 58, the rotation of the gate 571b of the casting sand filling part 57, the lifting and lowering of the hydraulic cylinder device 541 based on the extrusion table lifting device 54, the electric motor 553 in the sliding mechanism 552 of the descent limiting device 55, the electric motor 595 in the driving pinion 592 of the pressurizing drive device 59, the switching of the first electromagnetic switching valve SSV1 of the pressurizing implementation part 51, the switching of the second electromagnetic switching valve SSV2 of the retraction device 60, etc.

[0174] (Work)

[0175] The following reference Figures 1 to 11 、 Figures 14 to 16 The operation of the mold making apparatus 1 configured as described above will be described.

[0176] exist Figure 1 The upper mold carrier CU is positioned at the molding position MMP. The extrusion table is positioned at the standby position SBP (refer to Figure 2 ).

[0177] like Figure 2 As shown, the casting frame MF is positioned at the carrying-in / out position IOP above the upper mold carrier plate CU. An upper sand filling frame OLF is held above the casting frame MF.

[0178] A foundry sand filling unit 57 is positioned above the upper sand filling frame OLF, and a primary amount of foundry sand CS is stored in an upper portion of a hopper 571 .

[0179] The pressurizing unit 51 holds the contact body 594 b of the sliding member 594 at the raised end, and is positioned above the hopper 571 .

[0180] Next, the control device drives the hydraulic cylinder device 541 of the extrusion table lifting device 54 to raise the extrusion table 53 from the standby position SBP to the compression start position CSP (extrusion table raising process / refer to Figure 4 ).

[0181] In addition, the control device switches the electromagnetic switching valve (not shown) to increase the hydraulic pressure of the lower hydraulic cylinder 533 of the extrusion table 53, thereby raising the shaft member 533a. Then, the shaft member 533a is brought into contact with the lower end of the support rod member UFM of the lower sand filling frame ULF. The upper end portion ULFT of the lower sand filling frame ULF rises from the upper end surface MSPT of the model platform MSP, generating an extrusion amount (refer to Figure 4 ).

[0182] Thus, the lower sand filling frame ULF, the casting frame MF and the upper sand filling frame OLF overlap to form a superimposed frame PMF, which together with the model platform MSP forms a mold shaping space US (refer to Figure 3 ).

[0183] Next, the control device drives the slide mechanism 552 of the descent restricting device 55 to move the support member 551 from the support preparation position SRP to the support position SP (see FIG. Figure 14 as well as Figure 15 ). Thus, the support member 551 is arranged between the lower end of the table support portion 532 and the upper end of the support base portion 534 (Extrusion table lowering restriction process / refer to Figure 5 as well as Figure 6 ).

[0184] At this time, the support member 551 is biased upward by the coil spring 551c, moving so as to form a lower gap between the support member 551 and the support base 534. Therefore, when inserting the support member 551, the support member 551 can be inserted with an upper gap between the upper end of the support member 551 and the lower end of the stage support 532. After insertion, simply lowering the pressing stage 53 allows the support member 551 to support the applied force by easily and tightly contacting the lower end of the stage support 532 and the upper end of the support base 534 without any gap.

[0185] In addition, if Figure 5 As shown, the control device rotates the shutter 571b of the foundry sand filling portion 57 by 90 degrees, and causes the retained foundry sand CS to fall into the mold forming space US.

[0186] Next, if Figure 7As shown, the control device drives the pressurizing part / casting sand filling part switching device 58 to position the pressurizing part 51 from the retreat position RTP to the extrusion position PP opposite to the extrusion stage 53 (see Figure 2 The extrusion stage lifting device 54 is driven to lower the extrusion stage 53 so as to eliminate the gap, thereby bringing the support member 551, the stage support portion 532, and the support base portion 534 into close contact.

[0187] Next, if Figure 8 As shown, the control device drives the electric motor 595 of the pressurizing drive device 59 to rotate the swing arm 591 to the opposite end. This pressurizes the pressurizing portion 51 and squeezes the casting sand CS in the mold forming space US.

[0188] A retraction device 60 is provided between the pressurizing drive device 59 and the pressurizing unit 51. Therefore, even if the extrusion stroke height fluctuates at the end of pressurizing the foundry sand CS, pressurization can be performed at a predetermined pressure. Furthermore, any overload on the pressurizing drive device 59 generated during extrusion can be absorbed.

[0189] Extrusion is performed by performing both model surface extrusion from below the model surface and back surface extrusion from the back surface of the model surface, so-called double extrusion.

[0190] During pattern surface extrusion, while the pressure applying unit 51 is applying pressure to the upper surface of the casting sand CS, the pressure within the lower hydraulic cylinder 533 of the extrusion table 53 is reduced, allowing the shaft member 533a to retract. The lifting frame 512 of the pressure applying unit 51 is then brought into contact with the upper abutment portion OLF3 of the upper sand filling frame OLF, causing the overlap frame PMF to slide downward relative to the pattern platform MSP. The amount of sliding corresponds to the amount of extrusion achieved by the lower sand filling frame ULF. When the lower end of the casting frame MF and the upper surface of the pattern platform MSP are aligned in height, the sliding of the overlap frame PMF is stopped. This achieves pattern surface extrusion, which applies pressure to the casting sand MS from the pattern surface side.

[0191] During back pressing, the upper surface of the foundry sand CS is further pressurized by the pressing pins 511 of the pressurizing unit 51. Each pressing pin 511 presses at the same pressure, but the amount of entry into the foundry sand CS can be varied according to the shape of the mold, etc., to achieve balanced pressing.

[0192] Since dual extrusion of both mold surface extrusion and back surface extrusion is a well-known technique, detailed description thereof will be omitted.

[0193] Next, if Figure 9 As shown, the control device drives the pressurizing drive device 59 in the backward direction, so that the sliding member 594 moves upward.

[0194] Then, the slide mechanism 552 of the descent restricting device 55 is driven to move the support member 551 from the support position SP to the support preparation position SRP.

[0195] Next, if Figure 10 As shown, the control device drives the extrusion table lifting device 54 to lower the extrusion table 53.

[0196] As the pressing table 53 descends, the overlapping upper filling frame OLF, casting frame MF, and lower filling frame ULF are removed in sequence.

[0197] Next, if Figure 11 As shown, the control device lowers the pressing table 53 to the standby position SBP, and the swing arm 591 of the pressurizing drive device 59 also retreats to the initial position before pressurization.

[0198] Furthermore, the mold MWF with the casting frame after demolding is carried out from the carrying-in / out position IOP.

[0199] The same process is repeated below.

[0200] As is clear from the above description, the mold making machine 5 of the present embodiment is a mold making machine 5 that compresses the casting sand CS filled in the casting frame MF to form the mold MWF, wherein the mold making machine 5 includes: a pressurizing section 51 that contacts the casting sand CS; a pressing table 53 that is arranged opposite to the pressurizing section 51 and on which the carrier plate CU / CD overlapping the casting frame MF is placed; and a pressurizing drive device 59 that is arranged above the pressurizing section 51 and compresses the casting sand CS filled in the casting frame MF by bringing the pressurizing section 51 close to the pressing table 53.

[0201] The extrusion table 53 is equipped with: an extrusion table lifting device 54, which raises the extrusion table 53 from the standby position SBP to the compression start position CSP above the standby position SBP; and a descent limiting device 55, which, when the extrusion table 53 rises to the compression start position CSP, overcomes the compression force applied by the pressurizing drive device 59 during compression and limits the descent of the extrusion table 53.

[0202] Thus, the pressing table 53 and the carrier plate CU / CD can be raised to the compression start position CSP with a small driving force. When compression with a large force is required, the pressing force of the pressing drive device 59 can be overcome by the descent limiting device 55. In this way, since the raising to the compression start position CSP can be achieved with a small driving force instead of a large driving force, power waste can be reduced, thereby reducing running costs.

[0203] The pressurizing section 51 is provided separately from the pressurizing drive device 59 and is movable between a retreat position RTP away from the pressurizing drive device 59 and a pressing position PP where the pressurizing drive device can pressurize the pressurizing device.

[0204] As a result, the pressurizing section 51 serving as the moving portion is separated from the pressurizing drive device 59 and thus becomes compact, thereby enabling miniaturization of the drive device for movement and saving of the space required for movement.

[0205] The descent restricting device 55 includes a support member 551 , which is provided to be removable from under the pressing stage 53 after the pressing stage 53 has been raised to the compression start position CSP, thereby restricting the descent of the pressing stage 53 .

[0206] Thus, with the simple structure of the support member 551 provided below the pressing stage 53 , it is possible to restrict the downward movement of the pressing stage 53 against the large pressing force acting during the pressing.

[0207] Furthermore, the support member 551 is provided with a coil spring 551 c (biasing portion) that urges the support member 551 in a direction toward the pressing stage 53 .

[0208] Thus, the coil spring 551c creates a gap on the lower end side of the support member 551. Therefore, the support member 551 can be easily inserted under the pressing stage 53. Then, the coil spring 551c is compressed by the pressure applied during pressing, thereby eliminating the gap on the lower end side and achieving close contact.

[0209] In addition, an abutment column 602 (pressurization force transmission portion) is provided between the pressurization implementation portion 51 and the pressurization drive device 59 , and a retraction cylinder portion 601 that can retract according to the distance between the pressurization implementation portion 51 and the pressurization drive device 59 or the pressurization force is provided on the abutment column 602 .

[0210] Thus, even if the extrusion stroke height fluctuates when the foundry sand CS is pressurized, it can be pressurized at a predetermined pressure. In addition, it is possible to absorb the overload on the pressurizing drive device generated during extrusion.

[0211] In addition, in the above embodiment, the retraction device 60 is provided between the pressurizing drive device 59 and the pressurizing implementing portion 51, but the present invention is not limited thereto. Figure 17 As shown, the retracting device 160 may be provided on the lifting frame 152 of the pressurizing portion 151 and retracted at a position where the upper sand filling frame OLF is pressurized.

[0212] In the retraction device 160 of this example, retraction cylinders 1601, which are hydraulic cylinders, are installed at the four corners of the lifting frame 1512, and contact columns 1602 are brought into contact with the upper contact portion OLF3 of the upper sand filling frame OLF. This prevents overloading of the electric motor during compression and allows pressurization at a predetermined pressure even when the height fluctuates.

[0213] In addition, in the above embodiment, both the mold surface extrusion from the mold surface toward the top and the back extrusion from the top toward the bottom of the mold surface are performed, but the present invention is not limited thereto. For example, a mold molding machine that only performs back extrusion can also use the descent control device 55.

[0214] The present invention is not limited to the embodiments described above and shown in the drawings, but can be implemented with appropriate modifications within the scope of the present invention.

[0215] Description of Reference Numerals

[0216] 5: Mold forming machine; 51: Pressurization implementation unit; 53: Extrusion table; 54: Extrusion table lifting device; 55: Descending limiting device; 551: Support member; 551c: Coil spring (force applying unit); 59: Pressurization drive device; 60: Retraction device; 601: Retraction cylinder (retraction device); 602: Pressurization force transmission unit; CS: Casting sand; CSP: Compression start position; MF: Casting frame; MSP: Model platform; MWF: Mold with frame; PP: Extrusion position; RTP: Retraction position; SBP: Standby position; CU: Carrier plate for upper mold; CD: Carrier plate for lower mold; CU / CD: Carrier plate.

Claims

1. A mold-making machine for compressing casting sand filled in a casting frame to form a mold, wherein: The mold molding machine has: a pressurizing portion in contact with the foundry sand; a pressing platform, which is arranged opposite to the pressurizing portion and is used to carry the carrier plate overlapped by the casting frame; and A pressurizing drive device is provided above the pressurizing unit and compresses the casting sand filled in the casting frame by bringing the pressurizing unit close to the extrusion table. The extrusion station is equipped with: an extrusion table lifting device for raising the extrusion table from a standby position to a compression start position above the standby position; and A descent restricting device restricts descent of the pressing table by overcoming the pressing force applied by the pressurizing drive device to compress the foundry sand when the pressing table has ascended to the compression start position.

2. The mold forming machine according to claim 1, wherein: The pressurizing portion is provided separately from the pressurizing drive device and is movable between a retreat position away from the pressurizing drive device and a pressing position where the pressurizing portion can be pressed by the pressurizing drive device.

3. The casting molding machine according to claim 1 or 2, wherein: The descent restricting device includes a support member that is detachably provided below the pressing stage that has ascended to the compression start position and restricts descent of the pressing stage.

4. The mold forming machine according to claim 3, wherein: The support member is provided with a biasing portion that biases the support member in a direction toward the pressing stage.

5. The casting molding machine according to claim 1, wherein A pressurizing force transmitting portion is provided between the pressurizing implementing portion and the pressurizing driving device. The pressurizing force transmitting portion is provided with a retracting device that can be retracted according to the distance between the pressurizing applying portion and the pressurizing driving device or the pressurizing force.

6. A method for molding a mold, wherein the method uses a mold molding machine that compresses the casting sand filled in the casting frame to mold the mold, the mold molding machine comprising: a pressurizing portion that contacts the casting sand; a pressing table that is disposed opposite to the pressurizing portion and on which a carrier plate on which the casting frame overlaps is disposed; and a pressurizing drive device that is disposed above the pressurizing portion and compresses the casting sand filled in the casting frame by bringing the pressurizing portion close to the pressing table, wherein: The casting molding method comprises: a pressing table raising step of raising the pressing table from a standby position to a compression start position above the standby position; and The extrusion table descent limiting step includes limiting descent of the extrusion table by overcoming the pressing force of the pressurizing drive device during compression of the foundry sand in the extrusion table that has been raised to the compression start position.

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