JP2011147951A - Method for making mold, and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold making apparatus whose miniaturization can be achieved, in which a cleaning operation can be easily performed and by which equipment cost can be reduced. <P>SOLUTION: The mold making apparatus 2 includes an underlaying frame progression/retreat apparatus 14 progressing/retreating an underlaying frame 8 between a retreat position whose upper edge face coincides with the upper face of a master plate 36 and a progression position located at the pattern side than the above upper face. The underlaying frame progression/retreat apparatus includes: a first shaft member 42 fixed to the underlaying frame and projecting to the lower part than the lower face of the master plate; a second shaft member 30 provided at a squeeze table 6 movably up and down so as to be confronted with the first shaft member; and an energizing member 32 provided in a space between the squeeze table and the second shaft member, and increasing the underlaying frame to the progression position via the first member when the master plate is placed on the squeeze table by holding the second shaft member at an increasing edge position. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mold making method for squeezing from both the back side and the model surface side of a mold, and a mold making apparatus for carrying out the method.

  Conventionally, in molding, the strength of the mold has been increased by hardening the foundry sand inserted into the casting frame by squeezing a squeeze head from the back side of the mold. However, the back of the casting sand close to the squeeze head that the squeeze head hits is strongly squeezed, resulting in uneven strength of the mold. Since the effect of a squeeze is not effective, high shape accuracy cannot be obtained for the mold. Therefore, in addition to the squeeze from the back side of the mold, so-called double squeeze is also performed in which the squeeze is performed from the model surface side. According to Patent Document 1 that discloses such a double squeeze, a lower frame, a casting frame that has an inner surface along the inner surface of the lower frame and is placed on the upper surface of the lower frame, A base (master plate) that is movably fitted up and down relative to the lower frame and the casting frame along the inner surface of the lower frame and the casting frame, and fixed to the upper surface of the base A mold making apparatus comprising a model surface plate, a lower pressure head (squeeze table) for supporting the base from below, and an upper pressure head (squeeze head) located above the casting frame. The base has a stopper portion (stop portion), the lower end of the lower frame forms a bottom surface capable of contacting the upper surface of the stopper portion, and the lower frame has a rod portion and the rod portion. A pin member (shaft member) having a head portion formed at the lower end, and the upper end of the rod portion is fixed to the underlaying frame. Extending downward and penetrating the stopper portion of the base, the head portion is engaged with the lower surface of the stopper portion, and further interposed between the lower frame and the upper surface of the stopper portion of the base. The one provided with a biasing member is described.

  And, the vertical distance between the surface of the model surface plate and the lower end surface of the casting frame was kept equal to the vertical distance between the bottom surface of the underlay frame and the upper surface of the stopper portion of the base. In the state, the molding sand is filled into the space formed by the inner surface of the casting frame, the inner surface of the underlaying frame, and the upper surface of the model surface plate, and the position of the surface of the model surface plate is the bottom surface of the casting frame. Cast sand by lowering the upper pressure head (squeeze head), raising the lower pressure head (squeeze table), or lowering the upper pressure head and raising the lower pressure head until the position coincides with the vertical direction. Squeeze from the back side as well as from the model side. And after one process from filling of casting sand to mold release is completed, the molding apparatus automatically restores to a state where casting sand filling can be started by the cooperative action of the biasing member and the pin member (shaft member). It is described.

Japanese Patent No. 3342673

  However, in Patent Document 1, since the urging member is housed in the master plate (base) main body, an upper and lower space for incorporating the urging member is required, and the overall size of the master plate increases, resulting in an increase in size of the apparatus. As a result, there is a problem that the weight of the apparatus increases. Further, at the end of molding, the casting frame installation surface of the lower frame is in a state of being raised by the squeeze allowance on the model surface side with respect to the model surface. Therefore, when the molding sand pieces remaining on the upper surface of the model platen are cleaned by air blow after molding, the bottom frame raised by the squeeze amount becomes a barrier and the casting sand cannot be blown away. There was a risk of defects. Further, there are cases where a large number of spare master plates are held depending on the production system. In such a case, there is a problem that incorporating the urging members in all the master plates increases the equipment cost.

  The present invention has been made in view of such conventional problems, and an object of the present invention is to realize a mold making method and apparatus capable of realizing downsizing of the apparatus, facilitating cleaning work, and reducing equipment costs. Is to provide.

  The structural feature of the invention according to claim 1 is that a squeeze table and a squeeze head that are opposed to each other along a molding path and relatively moved forward and backward by a driving device, and a model mounted on the squeeze table and raised and lowered. A master plate attached to the upper surface, a lower frame provided on the master plate so as to be movable in the direction of the molding path surrounding the model, a casting frame that can be placed on the lower frame, An upper frame that can be placed on a casting frame, and a tip of a piston rod provided on the squeeze head is in contact with the upper surface of the upper frame, thereby restricting the upward movement of the upper frame relative to the squeeze head. Cylinder device enabling and lower frame advancement / retraction operation for moving the lower frame forward and backward between a retreat position where the upper end surface coincides with the upper surface of the master plate and a forward position positioned on the model side from the upper surface In the mold making apparatus, the lower frame advancement / retraction device includes a first shaft member that is fixed to the lower frame and protrudes downward from a lower surface of the master plate, and the first shaft member is disposed on the squeeze table. A second shaft member provided so as to be movable up and down, and between the squeeze table and the second shaft member, and by holding the second shaft member at the rising end position, the master And an urging member that raises the lower frame to the forward position via the first member when the plate is placed on the squeeze table.

  The structural feature of the invention according to claim 2 is that, in claim 1, the underlay frame advancement / retraction device includes a stop portion provided on the first shaft member, and a stop portion provided on the master plate. And a stop portion for positioning the underlaying frame at the retracted position by contact.

  A structural feature of the invention according to claim 3 is that, in claim 2, the first shaft member is fitted to the stop portion so as to be vertically movable.

  According to a fourth aspect of the present invention, there is provided a structural feature of the invention according to any one of the first to third aspects, wherein a casting frame delivery device for delivering a casting frame to and from the squeeze table in the molding path is provided. After completion, before retracting the squeeze table and delivering the casting frame to the casting frame delivery device, the underlaying frame is advanced by the repulsive force of the urging member to release the model from the mold. It is.

  According to the first aspect of the present invention, when the master plate is placed on the squeeze table, the first shaft member comes into contact with the second shaft member held at the rising end position by the biasing member, and the first shaft The member is pushed up by the urging force of the urging member to raise the lower frame to the forward position. In this manner, the advancing operation of the lower frame is performed using the urging force of the urging member. Also, when performing the model surface side squeeze, the squeeze table is relatively lifted to move the model surface plate upward, but the piston rod lowered to the point where it abuts the upper surface of the upper frame is against the squeeze head. Therefore, the lower frame is relatively retracted to the retracted position against the urging force of the urging member. Thereby, a lower frame, a casting frame, and an upper frame are hold | maintained in the state pressed strongly by the biasing member, and a model surface side squeeze can be performed.

  In this case, since the urging member that urges the lower frame is not provided on the master plate as in the conventional case but is provided on the squeeze table, the height of the master plate that affects the height of the mold making apparatus is reduced. It can be formed low, and the mold making apparatus can be miniaturized.

  In addition, when the squeeze table on which the master plate is placed is lowered and the placed master plate and the squeeze table are separated, the first shaft member is lowered away from the second shaft member, and the lower frame is Retreats by its own weight to the retreat position. Therefore, the upper surface of the lower frame and the upper surface of the master plate coincide with each other and become flat, so that the remaining foundry sand by air blow or the like can be easily blown off during cleaning. Thereby, it can prevent that the product defect by a residual casting sand piece arises.

  Moreover, since it is not necessary to incorporate a biasing member for each master plate as in the prior art, the equipment cost can be reduced.

  According to the second aspect of the present invention, in the underlaying frame advancing / retreating device, the underlaying frame is positioned in the retracted position by the contact between the stop portion provided on the first shaft member and the stop portion provided on the master plate. . By making the stop portion and the stop portion come into contact in this way, the underlaying frame can be reliably positioned at the retracted position, and this stop portion is provided on the first shaft member to stop the master plate. Since a dedicated part for contacting the part is not required, a mold making apparatus having a simple structure can be obtained.

  According to the invention of claim 3, since the first shaft member is fitted and guided to the stop portion so as to be movable up and down, the second shaft member is connected to the first shaft member like a squeeze from the model surface side. Even when a large force is applied from the underlaying frame, the model surface side squeeze is surely transmitted by reliably transmitting the force between the second shaft member and the underlaying frame without impairing the direction of the force. Can do.

  According to the invention of claim 4, the squeeze table or the squeeze head is brought close to each other to squeeze the foundry sand to form a mold, and after the squeeze is finished, the squeeze table is moved backward to receive the cast frame in the cast frame delivery device. Before delivery, the lower frame is moved forward by the repulsive force of the urging member so that the model is released from the mold. For example, the cast frame placed horizontally due to deterioration of the roller conveyor of the cast frame delivery device, etc. Even if it can no longer be maintained, the model can be released from the mold in a state in which the casting frame is maintained horizontally without being affected by such a casting frame delivery device. In this way, it has a simple structure that uses the repulsive force of the urging member, and by releasing the mold while keeping the casting frame horizontal, the occurrence of corner breakage of the mold and edge breakage of the projections can be prevented. be able to.

The schematic diagram which shows the Example of the casting_mold | template shaping apparatus of this invention. The elements on larger scale of a lower frame advance / retreat apparatus. The figure which shows the process of superposing | polymerizing each frame and throwing in casting sand. The figure which shows the preliminary | backup squeeze performed from the back side. The figure which shows a model surface side squeeze. The finished back side squeeze is shown. The figure which shows the state from which a model is released | separated from a casting_mold | template. The figure which shows the state which returned the squeeze table to the descending end and squeezed.

  An embodiment using a mold making apparatus according to the present invention will be described below with reference to the drawings. The mold making apparatus 2 includes a squeeze table 6 that moves the model platen 4 up and down along a vertical molding route, a lower frame 8 that surrounds the model platen 4, and a casting frame 10 that is placed on the lower frame 8. And the upper frame 12 placed on the casting frame 10, the forward position where the upper end of the lower frame 8 is positioned closer to the model side than the surface of the model surface plate 4, and the retracted position corresponding to the surface of the model surface plate The squeeze table 6 opposes the lower frame advance / retreat device 14 that moves forward and backward, the foundry sand supply device 18 that feeds the molding sand 16 into the molding space formed by the lower frame 8, the casting frame 10, the upper frame 12, and the like. A squeeze head 20 is provided for squeezing from the back the foundry sand 16 in the molding space, which is indexed to a position and raised by raising the squeeze table 6.

  The squeeze table 6 is formed in a rectangular cross section, and is fixed to the upper end of the piston 26 of the lower cylinder device 24 fixed to the device main body 22 so as to advance and retract in the vertical direction. At the four corners of the squeeze table 6, as shown in FIG. 2, cylindrical members 28 that constitute a part of the lower frame advance / retreat device 14 and have a bottom and a guide hole 28 a at the top are disposed. A second shaft member 30 having a flange portion 30a at the lower portion is fitted into the cylindrical member 28 so as to be vertically movable in the guide hole 28a, and the lower surface of the flange portion 30a of the second shaft member 30 and the upper surface of the bottom portion of the cylindrical member 28 are inserted. A coil spring 32 as an urging member is fitted between the two. These second shaft members 30 are urged in the forward direction by a coil spring 32, and are held at the rising end position by the upper surface of the flange portion 30a coming into contact with the lower surface of the edge portion of the guide hole 28a of the cylindrical member 28. When held at the raised end position, the tip end position of the second shaft member 30 is configured to coincide with the upper surface of the squeeze table 6.

  A master plate exchanging device 34 is disposed above the squeeze table 6 as shown in FIG. The master plate exchanging device 34 has a pair of roller conveyors 34a provided in the device main body 22 and extending in parallel with each other in the horizontal direction. The roller conveyor 34a is configured to removably support the lower surfaces of both sides of a stop portion 38 provided in a flange shape below the rectangular parallelepiped master plate 36. The master plate 36 is positioned at an exchange position facing the squeeze table 6 by a stop device (not shown) on the roller conveyor 34a, and is detachably mounted on the squeeze table 6 raised by the lower cylinder device 24. ing.

  A model surface plate 4 to which a model 40 is attached is fixed on the upper surface of the master plate 36, and a lower frame 8 is mounted on the outer periphery of the model surface plate 4 so as to be able to advance and retreat in the vertical direction around the model surface plate 4. ing. First shaft members 42 project downward from the four corners of the lower framing frame 8, and each first shaft member 42 is positioned at a position facing the second shaft member 30. Each first shaft member 42 is fitted into an upper and lower guide hole 38 a (see FIG. 2) penetrating the stop portion 38 of the master plate 36 so as to be movable up and down. A hook-shaped stop portion 44 is provided at the upper intermediate portion of the first shaft member 42, and the lower surface of the stop portion 44 contacts the upper surface of the stop portion 38 of the master plate 36, so that the first shaft member 42 is The provided underlaying frame 8 is configured not to move relatively downward from the retracted position. These first shaft members 42 are in a state of protruding downward from the lower surface of the master plate 36 with the stop portion 44 in contact with the stop portion 38. When the master plate 36 is exchanged by the master plate exchanging device 34, a gap is formed between the lower end of the first shaft member 42 and the tip of the second shaft member 30 as shown in FIG. ing. Further, when the squeeze table 6 is raised by driving the lower cylinder device 24 and the master plate 36 is placed in a state where the upper surface of the squeeze table 6 is in contact with the lower surface of the master plate 36, the second squeeze table 6 is provided. The tip end of the shaft member 30 is in contact with the lower end of the first shaft member 42, and the first shaft member 42 is raised by the biasing force of the coil spring 32 biasing the second shaft member 30 upward. Advance to the forward position.

  The casting frame 10 placed on the lower filling frame 8 is held by a casting frame delivery device 46 above the lower filling frame 8 in FIG. The frame delivery device 46 includes a pair of roller support members 48a extending in parallel to each other in the horizontal direction (a direction perpendicular to the roller conveyor 34a of the master plate changer 34), and a plurality of the steel frame delivery devices 46 facing the inside of the roller support members 48a. It has an upper roller conveyor 48 composed of rollers 48b that are rotatably provided. The upper roller conveyor 48 supports the lower surfaces of both sides of the casting frame 10 so as to be detachable above the master plate changing device 34. Next, the cast frame 10 to be cast is positioned on the upper roller conveyor 48 by a stop device (not shown) at a cast frame delivery position facing the squeeze table 6 in the molding path, and is raised by the lower cylinder device 24. The lower frame 8 fitted to the master plate 36 placed on the table 6 is raised to the forward position by the lower cylinder device 24, and the cast frame 10 is placed on the casting frame contact surface (upper surface) of the lower frame 8. Is received from the upper roller conveyor 48. The upper frame support member 50 is provided on the casting frame delivery device 46 so as to protrude upward from the upper part of each roller support member 48a, and the upper frame support member 50 supports the upper frame 12 from below. The upper frame support member 50 is a bar having a tapered guide at the tip, and the tip of the upper frame support member 50 is engaged with and disengaged from the respective support holes 12 a provided at the four corners of the lower surface of the upper frame 12. Fit as possible. The upper frame support member 50 is formed longer than the height of the casting frame 10, and supports the upper frame 12 with a gap between the upper surface of the casting frame 10 and the lower surface of the upper frame 12. . The overlay frame 12 placed on the cast frame 10 is held above the cast frame 10 by the overlay frame support member 50. As the squeeze table 6 is raised by the lower cylinder device 24, the master plate 36 is placed on the squeeze table 6, and the casting frame 10 is placed on the lower frame 8 that is raised to the forward position by the coil spring 32 of the lower frame advance / retreat device 14. The overlay frame 12 is sequentially polymerized.

  A shuttle device 52 that moves in the horizontal direction is provided above the device main body 22, and the foundry sand supply device 18 and the squeeze head 20 are juxtaposed with the shuttle device 52. The foundry sand supply device 18 and the squeeze head 20 are positioned by being indexed to a sand supply position and a squeeze position by a shuttle cylinder 52a of the shuttle device 52, respectively.

  The foundry sand supply device 18 is provided with a shutter (not shown) composed of a plurality of bottom plates at the lower end of the container main body for storing the foundry sand 16, and the shutter is rotated around a horizontal axis by a not-shown rotating device. When the bottom plate of the shutter is turned to the horizontal state, the foundry sand 16 is stored, and when the bottom plate is turned to the vertical state, the foundry sand 16 falls. When indexed to the sand supply position by the shuttle device 52, the foundry sand supply device 18 faces the lower frame 8, the cast frame 10, and the upper frame 12 that are superposed, and the weighed foundry sand 16. Into the frame.

  As shown in FIG. 1, the squeeze head 20 has a squeeze plate portion 54 that can be inserted into a superposed frame and presses the upper surface of the foundry sand 16 in the frame raised by the squeeze table 6 rising. is doing. On the four corners of the squeeze head 20, upper frame stoppers 56 are provided. The upper frame stopper 56 has a hydraulic cylinder mechanism including a downward piston portion 56a that advances and retreats downward. The lower end of the downward piston portion 56 a can come into contact with the upper end of the upper frame 12. The hydraulic cylinder mechanism is communicated with the hydraulic pump 60. An electromagnetic switching valve 62 is provided between the hydraulic cylinder mechanism and the hydraulic pump 60, and the hydraulic pressure is controlled by opening and closing the electromagnetic switching valve 62. In addition, an electromagnetic switching valve 64 is provided in the middle of the hydraulic cylinder mechanism and the electromagnetic switching valve 62, and these solenoid switching valve 62 and electromagnetic switching valve 64 can pressurize, release, and maintain the state of the upper frame stopper 56. Done.

  For example, when the downward piston portion 56a of the upper frame stopper 56 is pressurized downward, the electromagnetic switching valve 62 is positioned at a position communicating with the hydraulic pump 60 at the right position, and the electromagnetic switching valve 64 is set at the block position at the right position. Position. When the downward piston portion 56a is in an open state where no pressure is applied, the electromagnetic switching valve 62 is positioned at the left block position, and the electromagnetic switching valve 64 is positioned at the left drain position. When maintaining the downward piston portion 56a not to move up and down, both the electromagnetic switching valve 62 and the electromagnetic switching valve 64 are positioned at the block position.

  Next, the operation of the mold making apparatus configured as described above will be described below with reference to the drawings. First, as shown in FIG. 1, the foundry sand supply device 18 is indexed to the sand supply position by the shuttle device, and is disposed above the squeeze table 6. At that time, between the squeeze table 6 and the foundry sand supply device 18, the master plate 36 placed on the master plate changer 34, the model platen 4 placed and fixed on the master plate 36, the model platen 4 An underlaying frame 8 surrounding the model 40, the model surface plate 4 and the master plate 36 fixed to the board surface is arranged. Further, the upper frame 12 supported by the upper frame support member 50 and the casting frame 10 held at the delivery position of the casting frame delivery device 46 are disposed above the lower construction frame 8. In the lower frame advance / retreat apparatus 14, the second shaft member 30 is held at the rising end by the biasing force of the coil spring 32. In the first shaft member 42, the lower surface of the stop portion 44 abuts on the upper surface of the stop portion 38 of the master plate 36 to hold the lower frame 8 in the retracted position, and the lower end protrudes below the lower surface of the master plate 36. .

  Next, as shown in FIG. 3, the lower cylinder device 24 is driven to raise the squeeze table 6. First, the master plate 36 is placed on the squeeze table 6. At this time, the tip end of the second shaft member 30 held at the rising end comes into contact with the lower end of the first shaft member 42, and the first shaft member 42 is biased upward, whereby the stop portion 44 is stopped. And the underlay frame 8 is positioned at the advanced position.

  Next, when the squeeze table 6 is further raised, the casting frame 10 is received from the casting frame delivery device 46, and the casting frame 8 is placed on the upper surface (casting frame contact surface) of the lower frame 8. Further, by raising the squeeze table 6, the upper frame 12 is received from the upper frame support member 50 and the upper frame 12 is placed on the upper surface of the casting frame 10. In this way, a molding space is formed by the inner surfaces of the polymerized lower frame 8, the cast frame 10, and the upper frame 12, and the surfaces of the model surface plate 4 and the model 40.

  Next, the foundry sand 16 weighed and stored in the foundry sand supply device 18 is thrown into the molding space by the bottom plate of the shutter being turned vertically by the turning device of the foundry sand supply device 18. The

  Next, as shown in FIG. 4, the squeeze head 20 is indexed to the squeeze position by driving the shuttle cylinder 52 a (see FIG. 1) of the shuttle device 52 and faces the squeeze table 6.

  Next, as shown in FIG. 4, the lower cylinder device 24 is driven to further raise the squeeze table 6, so that the squeeze head 20 is inserted into the upper part of the upper frame 12 until the squeeze head 20 is inserted into the upper frame 12. 10. Raise the upper frame 12 and the model platen 4. The electromagnetic switching valve 62 is held at the left block position, and the electromagnetic switching valve 64 is held at the left drain position. As a result, the downward piston portion 56a of the upper frame stopper 56 becomes movable in a state where the tip is in contact with the upper frame 12, and the downward piston portion 56a can move relative to the squeeze head 20. . Then, the squeeze table 6 is further raised, and a back side squeeze squeeze is performed from the back side of the mold to be molded. By this preliminary squeeze, it is possible to ensure the uniformity of compaction during the back side squeeze for finishing in the subsequent process.

  Next, as shown in FIG. 5, the electromagnetic switching valve 64 is switched to the right block position. Thereby, the backward movement of the downward piston portion 56a of the upper frame stopper 56 is restricted, and the upward movement of the upper frame 12 relative to the squeeze head 20 is restricted. In this state, the lower cylinder device 24 is driven to raise the squeeze table 6 so that the upper surface of the master plate 36 (the surface of the model surface plate 4) matches the upper surface of the lower frame 8 (the contact surface of the casting frame). The model surface side squeeze is performed by moving it until it reaches (retracted position). In this way, the upper frame 12 that contacts the downward piston portion 56a that is restricted from retreating, and the casting frame 10 and the lower frame 8 that overlap with the upper frame 12 are restricted from rising. The master plate 36 is raised relative to the lower frame 8 until the upper surface of the stop portion 38 of 36 and the lower surface of the stop portion 44 of the first shaft member 42 come into contact with each other. Then, the lower frame 8 is relatively retracted until the upper surface of the lower frame (casting frame contact surface) and the upper surface of the master plate 36 (the surface of the model surface plate 4) coincide.

  Next, as shown in FIG. 6, the electromagnetic switching valve 64 is switched to the left drain position. As a result, the downward piston portion 56a of the upper frame stopper 56 is in a state of being able to advance and retreat in a state where the tip is in contact with the upper frame 12. In this state, the lower cylinder device 24 is driven to further raise the squeeze table 6, and the lower frame 8, the cast frame 10, the upper frame 12, and the model surface plate 4 are raised to perform the finishing rear side squeeze.

  When the rear side squeeze is completed, the squeeze table 6 is lowered by the lower cylinder device 24 as shown in FIG. Then, the lower frame 8 is relatively raised to the forward position by the urging force of the coil spring 32, and the casting frame 10 placed on the lower frame 8 is also raised with respect to the master plate 36, the model surface plate 4, and the model 40. Therefore, the model 40 and the model surface plate 4 are released from the mold 66 before the casting frame 10 is delivered to the casting frame delivery device 46.

  Then, as shown in FIG. 8, the squeeze table 6 is further lowered, the upper frame 12 is placed on the upper frame support member 50 and separated from the casting frame 10, and the casting frame 10 is received by the casting frame delivery device 46. By being handed over, it leaves the underlaying frame 8. The cast frame (including the mold) placed on the cast frame delivery device 46 is conveyed to an unillustrated pouring station by the upper roller conveyor 48. Before the squeeze table 6 is lowered to the lower end, the master plate 36 is transferred onto the master plate changer 34.

  When the squeeze table 6 is positioned at the descending end, the electromagnetic switching valve 62 is switched to the hydraulic pump communication position at the right position, and the electromagnetic switching valve 64 is switched to the block position at the right position, thereby returning the downward piston portion 56a to the descending end. Let Then, if the upper mold was previously formed, the master plate 36 to which the lower mold model was attached was positioned at the replacement position, and the empty casting frame 10 was positioned at the casting frame delivery position. The above cycle is repeated.

  According to the mold making apparatus 2 configured as described above, when the master plate 36 is placed on the squeeze table 6, the first shaft member 30 is held on the second shaft member 30 held at the rising end position by the coil spring 32. 42 abuts and the first shaft member 42 is pushed up by the urging force of the coil spring 32 to raise the lower frame 8 to the advanced position. In this way, the forward movement of the lower frame 8 is performed using the biasing force of the coil spring 32. Further, when the model surface side squeeze is performed, the squeeze table 6 is relatively lifted to move the model surface plate 4 upward, but the downward piston portion 56a that has been lowered to contact with the upper surface of the upper frame 12 is provided. The squeeze head 20 is held so as not to be able to advance and retract, and against the biasing force of the coil spring 32, the lower overlay frame 8 is relatively retracted to the retracted position. Thereby, the lower frame 8, the cast frame 10, and the upper frame 12 are hold | maintained in the state pressed strongly by the coil spring 32, and can perform a model surface side squeeze. Thus, with the simple structure of the coil spring 32, the lower frame 8 can be easily and reliably advanced and retracted between the forward position and the backward position.

  In this case, since the coil spring 32 for biasing the underlay frame 8 and the cylindrical member 28 into which the coil spring 3 is inserted are provided not on the master plate 36 but on the squeeze table 6 as in the prior art, the mold making process is performed. The height of the master plate 36 that directly affects the height of the apparatus 2 can be formed low, and the mold making apparatus 2 can be downsized.

  Further, the squeeze table 6 on which the master plate 36 is placed is lowered, and the placed master plate 36 and the squeeze table 6 are separated, whereby the first shaft member 42 is separated from the second shaft member 30 and lowered. The underlaying frame 8 is retracted by its own weight to the retracted position. Therefore, since the upper surface of the underlaying frame 8 and the upper surface of the master plate 36 coincide and become flat, the remaining foundry sand due to air blow or the like can be easily blown off during cleaning. Thereby, it can prevent that the product defect by a residual casting sand piece arises.

  Further, since it is not necessary to incorporate the coil spring 32 for each master plate 36 as in the prior art, the equipment cost can be reduced.

  In the lower frame advance / retreat apparatus 14, the stop frame 44 provided on the first shaft member 42 and the stop portion 38 provided on the master plate 36 come into contact with each other to position the lower frame 8 in the retracted position. In this way, the stop frame 44 and the stop portion 38 are brought into contact with each other, so that the lower frame 8 can be reliably positioned at the retracted position, and the stop portion 44 is provided on the first shaft member 42. In addition, since a dedicated part for contacting the stop portion 38 of the master plate 36 is not required, a mold making apparatus having a simple structure can be obtained.

  In addition, since the first shaft member 42 is guided by being fitted to the stop portion 38 so as to be movable up and down, the second shaft member 30 and the lower overlay are formed on the first shaft member 42 like a squeeze from the model surface side. Even when a large force is applied from the frame 8, the model surface side squeeze can be surely transmitted by reliably transmitting the force between the second shaft member 30 and the underlaying frame 8 without impairing the direction of the force. Can do.

  Further, the squeeze table 6 or the squeeze head 20 are brought close to each other to squeeze the foundry sand 16 to form a mold 66. After the squeeze is completed, the squeeze table 6 is moved backward to receive the casting frame 10 by the casting frame delivery device 46. Before delivery, the lower frame 8 is moved forward by the repulsive force of the coil spring 32 so that the model 40 is released from the mold 66. For example, the upper frame conveyor 48 of the casting frame delivery device 46 is placed due to deterioration or the like. Even if the cast frame 10 cannot be kept horizontal, the model 40 is released from the mold 66 in a state in which the cast frame 10 is kept horizontal without being affected by the cast frame delivery device 46. can do. In this way, it has a simple structure using the repulsive force of the coil spring, and by releasing the mold 10 while keeping the casting frame 10 horizontal, it is possible to prevent the occurrence of corner chipping of the mold 66 and edge breakage of the protrusions. be able to.

  In the above embodiment, the urging member is a coil spring, but is not limited to this. For example, a leaf spring material, a rubber material, an air spring, etc. cause elastic deformation when loaded, and the generated elastic deformation Any device may be used as long as it generates an urging force.

  Further, the upper frame support member is a bar projectingly provided on the roller support member of the cast frame delivery device. However, the upper frame support member is not limited to this, and for example, a frame material capable of supporting the lower end of the upper frame in a detachable manner. But you can.

  Thus, the specific configuration described in the above-described embodiment is merely an example of the present invention, and the present invention is not limited to such a specific configuration. Various embodiments can be adopted without departing from the scope.

DESCRIPTION OF SYMBOLS 2 ... Mold making apparatus, 4 ... Model surface plate, 6 ... Squeeze table, 8 ... Lower frame, 10 ... Cast frame, 12 ... Upper frame, 14 ... Lower frame advance / retreat apparatus, 18 ... Foundry sand supply apparatus, 20 ... squeeze head, 30 ... second shaft member, 32 ... biasing member (coil spring), 36 ... master plate, 36a ... stop portion, 40 ... model, 42 ... first shaft member, 44 ... stop portion, 46 ... casting frame Delivery device, 56 ... upper frame stopper, 56a ... piston rod (downward piston portion), 66 ... mold.

Claims (4)

A squeeze table and a squeeze head that are moved forward and backward relative to each other along a molding route, a master plate mounted on the squeeze table and mounted on the upper surface, and a model mounted thereon. A surrounding frame provided on the master plate so as to be movable in the direction of the molding path, a casting frame that can be placed on the lower building frame, and a building frame that can be placed on the casting frame; A cylinder device provided on the squeeze head, the tip of a piston rod being in contact with the upper surface of the upper frame, and capable of restricting the upward movement of the upper frame relative to the squeeze head; and the lower frame In a mold making apparatus comprising: a lower frame advancement / retraction device that moves back and forth between a retreat position where the upper end surface coincides with the upper surface of the master plate and a forward position located on the model side from the upper surface;
The lower frame advancement / retraction device includes a first shaft member fixed to the lower frame and protruding downward from a lower surface of the master plate;
A second shaft member provided on the squeeze table so as to be vertically movable facing the first shaft member;
When the master plate is placed on the squeeze table, the first member is provided between the squeeze table and the second shaft member, and holds the second shaft member in the raised end position. And a biasing member that raises the underlaying frame to the forward position via a mold.   2. The lower frame advancement / retraction device according to claim 1, wherein the lower frame is positioned at the retracted position by contacting a stop portion provided on the first shaft member and the stop portion provided on the master plate. A mold making apparatus comprising: a stop portion that performs the above-described operation.   3. The mold making apparatus according to claim 2, wherein the first shaft member is fitted to the stop portion so as to be movable up and down. In any 1 item | term of the Claims 1 thru | or 3, the cast frame delivery apparatus which delivers a cast frame between the said squeeze tables in the said shaping path is provided,
After the squeeze is completed, before the squeeze table is retracted and the casting frame is transferred to the casting frame delivery device, the lower frame is advanced by the repulsive force of the urging member to release the model from the mold. A mold making method characterized by the above.

Images