JP2000117394A - Flaskless type molding machine and flaskless type molding method using this - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding machine having a structure, in which the compacting force of molding sand particularly in the outer peripheral portion can sufficiently and stably be obtd. when a flaskless type mold is molded. SOLUTION: Squeeze plates 19, 19 for applying the compacting force to the molding sand 38 filled up in molding frames 10, 12 are divided into the center portion 40 and the outer peripheral portion 42. These portions are independently driven and then, the mutually different compacting pressures in the center portion 40 and the outer peripheral portion 42 can be acted on the molding sand 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding technique of a frameless mold having no mold, and more particularly to a frameless mold capable of stably molding a target mold with excellent compaction strength. And a molding method.

[0002]

2. Description of the Related Art Conventionally, as one type of a frameless mold making machine, as described in Japanese Patent Application Laid-Open No. 8-323449, a pattern is formed at one opening of a mold having a cylindrical frame shape. The plates are overlapped and a squeeze plate is fitted from the other opening of the mold to form a molding space between the opposing surfaces of the pattern plate and the squeeze plate in the mold, and the squeeze plate is placed on the pattern plate side. There is known a frameless mold molding machine that is configured to form a mold in which the shape of a model provided on a pattern plate is transferred by compacting a molding sand filled in a molding space by driving the mold forward. ing.

In such a frameless mold, since it is used after being removed from the mold after molding, it is important to secure the strength by sufficiently compacting the molding sand.

[0004] However, in a conventional frameless mold molding machine employing a squeeze plate having a single structure with a flat pressing surface, it is sometimes difficult to efficiently compact the molding sand by advancing the squeeze plate. there were. In particular,
In the outer peripheral part near the formwork, in addition to the effects of friction and stress propagation characteristics between the formwork and the molding sand, the effective compaction force is stabilized by the movement resistance of the molding sand by the model protruding from the pattern plate. In some cases, it is difficult to secure a sufficient mold strength, and in some cases, the shape and size of a model that can be set are greatly limited.

[0005]

Here, the present invention has been made in view of the above-mentioned circumstances, and a problem to be solved is to avoid molding sand compaction defects and the like particularly in the outer peripheral portion, It is an object of the present invention to provide a frameless mold making machine capable of stably producing a frameless mold having good strength, and an advantageous method of producing a frameless mold using such a frameless mold making machine.

[0006]

A feature of the present invention relating to a frameless mold molding machine is to solve the above problem.
A pattern plate is superimposed on one opening of a mold having a cylindrical frame shape, and a squeeze plate is fitted from the other opening of the mold to form the pattern plate and the squeeze in the mold. A molding space is formed between the opposing surfaces of the plates, and the squeeze plate is driven forward to the pattern plate side to compact the molding sand filled in the molding space. The plate is divided into at least a central portion and an outer peripheral portion, and the central portion and the outer peripheral portion can be independently displaced forward on the pattern plate side, and the respective forward driving forces exerted on the central portion and the outer peripheral portion Are provided independently of each other.

[0007] In the mold making machine having the structure according to the present invention, the squeeze plate which exerts compaction pressure on the molding sand is divided into at least a central portion and an outer peripheral portion. The central part and the outer peripheral part can be displaced forward independently of each other,
Compaction pressure exerted on the foundry sand by the outer periphery,
Since the compaction pressure exerted on the molding sand by the central part can be adjusted separately, both the central part and the peripheral part of the mold can be adjusted according to the shape and size of the model formed on the pattern plate and the condition of the molding sand. Thus, an effective compaction pressure can be applied to each of the molds, and thus a frameless mold that is fully compacted as a whole can be stably manufactured.

In the present invention, any of conventionally known molds and pattern plates can be used. For example, a pair of molds are axially overlapped and held with the pattern plate interposed therebetween. At the same time, a squeeze plate is fitted from each axially outer opening of each frame body, and the molding sand filled in the molding space in each frame body is compacted, so that a pair of frameless molds that are mutually matched are simultaneously formed. A structure or the like designed to be molded can be suitably adopted. Also, for example, under a state in which both side openings of the mold held so that the central axis extends in the horizontal direction are covered with a pattern plate and a squeeze plate, the molding space is supplied to the molding space through a supply port opened vertically above the mold. Employing a structure in which molding sand is filled and compacted is also effective for further improving the compacting property of the mold by improving the filling property of molding sand.

The driving means for applying a driving force to the squeeze plate includes a first driving means capable of directly controlling a driving force applied to a central portion of the squeeze plate, and a first drive means for controlling an outer peripheral portion of the squeeze plate. Preferably, it comprises a second drive means capable of directly controlling the applied driving force, whereby the compaction pressure exerted on the molding sand by the central part and the molding sand by the outer peripheral part. Can be easily controlled independently of one another with great freedom. As the first and second driving means, for example, any of a hydraulic cylinder and an electric motor can be adopted. Further, by employing various driving force reducing means using a spring, a link mechanism, or the like, it is possible to apply different driving forces to the central portion and the outer peripheral portion of the squeeze plate by one driving means. .

More specifically, the driving means is interposed, for example, between a support member fixedly disposed on the mold and a central portion of the squeeze plate. A first drive mechanism for driving in the approach / separation direction with respect to the pattern plate, interposed between a central portion of the squeeze plate and the outer peripheral portion of the squeeze plate, and On the other hand, a second driving mechanism for driving in the approaching / separating direction with respect to the pattern plate may be advantageously included.

Further, the outer peripheral portion of the pattern plate which can be displaced independently from the central portion includes, for example, an outer peripheral edge slidably in contact with an inner peripheral surface of the formwork, and extends in the circumferential direction along the outer peripheral edge. It is advantageously formed with an annular structure that extends continuously with a substantially constant width over the entire circumference. Further, in this case, both the outer peripheral portion and the central portion of the pattern plate are brought into sliding contact with the inner peripheral surface of the outer peripheral portion of the mold or the pattern plate during forward drive. In order to prevent molding sand and the like from entering between the sliding contact surfaces, for example, it is desirable to dispose a seal member on each outer peripheral edge of the outer peripheral portion and the central portion of the pattern plate.

Further, in the frameless mold molding machine having the structure according to the present invention, for example, the outer peripheral portion of the squeeze plate is constituted by a plurality of outer peripheral divided bodies divided at a plurality of positions in a circumferential direction, A configuration in which each of the outer peripheral division bodies can be independently displaced forward on the pattern plate side, and a forward driving force exerted on each of the outer peripheral division bodies by the driving means can be set independently of each other. It is preferably adopted. If such a configuration is adopted, for example, since the protrusion amount and shape of the model are partially deviated or complicated, even in the outer peripheral portion of the molding space, the filling property and the tightening of the molding sand in the circumferential direction are partially performed. Even in the case where the transmission of the compaction pressure is poor, the compaction of the molding sand in the circumferential direction can be made uniform by mutually adjusting the forward driving force applied to each outer peripheral divided body. Further, the uniformity of compaction of the entire mold can be realized. In the case where a plurality of outer divided bodies are employed as described above, a plurality of divided drive units which can directly control the driving force applied to each outer divided body are used as driving means for applying a driving force to the squeeze plate. It is desirable to employ means. Also, the central portion of the squeeze plate can be divided into a plurality of portions that can be advanced and displaced independently of each other, and these divided portions can apply different pressures to the molding sand. is there.

Further, in the frameless molding machine having the structure according to the present invention, the pressing area of the outer peripheral portion of the squeeze plate against the molding sand is 5% to 35% of the total pressing area of the squeeze plate against the molding sand. It is desirable to set so that However, the pressing area of the outer peripheral portion is too large relative to the total pressing area of the squeeze plate, or even too small, because it becomes difficult to adjust the compaction force exerted on each part of the mold, especially This is because the compaction force in the outer peripheral portion of the mold is likely to be insufficient.

A feature of the present invention relating to a method of molding a frameless mold is that the molding space is filled with molding sand by using a frameless mold molding machine having a structure according to the present invention as described above. After that, when the squeeze plate is driven forward to the pattern plate side to form a frameless mold by compacting the molding sand filled in the molding space, the central portion and the outer peripheral portion of the squeeze plate are formed. Simultaneously, after the central portion reaches a preset pressure, only the outer peripheral portion is further driven forward until the pressure reaches a preset pressure separately from the central portion.

According to the method of the present invention, first, the central portion and the outer peripheral portion of the squeeze plate are integrally driven to move forward, so that the molding sand filled in the casting flask is pressed against the pressing surface of the squeeze plate. After being pressed and compacted by the whole, the outer peripheral portion is further driven forward with respect to the central portion, so that a greater pressing force acts on the outer peripheral portion of the molding sand filled in the flask. I'm sullen. Therefore, ultimately, a large compaction force is exerted also on the outer peripheral portion of the molding sand filled in the flask, so that insufficient compaction of the outer peripheral portion is avoided, and the overall It is possible to obtain a highly compacted frameless mold. In addition, the pressure preset in the central portion and the outer peripheral portion of the squeeze plate is a final target value of the compaction force (pressing force) per unit area exerted on the surface of the molding sand by the central portion and the outer peripheral portion. Say.

Further, the present invention relating to a method of molding a frameless type mold, uses a frameless type mold molding machine having a structure according to the present invention as described above, and fills the molding space with molding sand.
When the squeeze plate is driven to the pattern plate side and the molding sand filled in the molding space is compacted to form a frameless mold, the pressure exerted on the molding sand by the squeeze plate is applied to the center. After individually setting the central portion and the outer peripheral portion, forward drive of the central portion and the outer peripheral portion is simultaneously started, and the central portion and the outer peripheral portion are independently displaced until the respective set pressures are reached. A method of forming a frame mold is also characterized.

According to the method of the present invention, when compacting the foundry sand, the central portion and the outer peripheral portion of the squeeze plate are simultaneously started to be driven forward, and are independently displaced in accordance with each set pressure. As a result, the central portion and the outer peripheral portion of the squeeze plate can be quickly advanced to the final position, whereby the molding cycle of the mold can be improved. The set pressure of the central portion and the set pressure of the outer peripheral portion of the squeeze plate are set in accordance with the shape and size of the model formed on the pattern plate, so that the central portion and the outer peripheral portion of the mold can be sufficiently compacted. To be,
It is set arbitrarily for each. Specifically, for example, the set pressure of the outer peripheral portion is set to be larger than that of the central portion, so that a larger pressing force than the central portion is applied to the outer peripheral portion of the molding sand filled in the flask. It is also possible to advantageously prevent insufficient compaction of the outer peripheral part. Further, for example, when there is a portion having a large protrusion height in a part of the model, it is also possible to set the set pressure of the central portion to be larger than that of the outer peripheral portion. Insufficient compaction due to the part where the diameter is large or due to the next phenomenon can be advantageously prevented.

Further, in forming the frameless mold according to the method of the present invention as described above, in any case, the outer peripheral portion of the squeeze plate is protruded from the central portion and is driven forward toward the pattern plate. rear,
A molding method in which the outer peripheral portion is once retracted to the side away from the pattern plate, and then the central portion and the outer peripheral portion of the squeeze plate are driven forward toward the pattern plate side according to the method described above is suitably adopted. You.

If such a method is adopted, the outer peripheral portion of the squeeze plate is driven forward and then retracted,
Precompression (preliminary compaction) is applied to the outer peripheral portion of the molding sand filled in the formwork. Thereafter, the method of the present invention as described above is performed again, so that the outer peripheral portion of the mold can be further improved. It can be highly compacted, and in particular, it is possible to exert a large compaction force or compaction action on the outer peripheral portion of the mold without setting the driving force on the outer peripheral portion of the squeeze plate so much. Become.

In this case, in particular, the pressure when the outer peripheral portion is driven forward in the pre-compression and the pressure when the outer peripheral portion is driven forward in accordance with the above-described method are adjusted to different values. Is desirable. Specifically, for example, at the time of pre-compression, the pressure exerted on the molding sand by the outer peripheral portion of the squeeze plate can be set to be smaller than the set pressure at the time of final compaction. An effective compacting effect of the mold is exhibited.

Further, the present invention relates to a method of molding a frameless mold, wherein the molding space is filled with molding sand using a frameless mold molding machine having a structure according to the present invention as described above, and then the squeeze plate is molded. At the time of forming the frameless mold by compacting the molding sand filled in the molding space, the outer peripheral portion of the squeeze plate is independently driven forward from the central portion. Further, a method of molding a frameless mold in which only the central portion is driven forward while the outer peripheral portion is held at a predetermined pressure.

According to the method of the present invention, since the outer peripheral portion of the mold is compacted before the central portion, the compacting force of the molding sand by the forward drive of the squeeze plate exerts a force on the outer peripheral portion. , The outer periphery can be more preferentially compacted.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIG. 1 schematically shows the entire structure of a frameless mold making machine having a structure according to the present invention. In such a frameless mold making machine, the upper frame 10 and the lower frame 12 as molds each have a substantially rectangular cylindrical frame shape, and the guide bar 1 provided on the support base 16 is provided.
4 support the movable members 4 so as to be movable toward and away from each other. The upper frame 10 and the lower frame 12
Is supported by a reversing cylinder 18.
It can be reciprocated about 90 degrees in the direction of the arrow in the figure. Further, as shown by the phantom line in the drawing, at the rotation position of the support base 16 where the upper frame 10 and the lower frame 12 are superimposed in the horizontal direction, the upper frame 10 and the lower frame 12 Located on both sides in the superposition direction,
An upper squeezing device 20 and a lower squeezing device 22 each having a squeeze plate 19 are provided, respectively, and a blowing device 23 is provided above the upper frame 10 and the lower frame 12. . Meanwhile,
As shown by a solid line in the drawing, the upper frame 10 and the lower frame 12 are superimposed on each other at the rotation position of the support base 16 where the upper frame 10 and the lower frame 12 are vertically superimposed. A mold removing device 24 and a mold receiving device 26 are disposed on both sides in the direction.

When molding a mold by the frameless mold molding machine having such a structure, first, when the support base 16 is rotated as shown by a solid line in FIG. As shown in the drawing, a model 28 molded into a required casting shape is integrally formed at a central portion between the opposing surfaces of the upper frame 10 and the lower frame 12 by a pattern transfer device (not shown). Flat plate pattern plate 3
0 is guided and positioned, and the pattern plate 3
The upper frame 10 and the lower frame 12 are overlapped with 0 therebetween. Thereby, both the upper frame 10 and the lower frame 12 are in one opening (the opening which is overlapped with each other).
It is covered with the pattern plate 30 and closed in a hermetically closed manner.

Thereafter, as shown in FIG. 3, the support base 16 is turned to a turning position as shown by a virtual line in FIG. The squeeze plates 19 and 19 of the upper squeezing device 20 and the lower squeezing device 22 are fitted into the respective outer openings, and the openings are covered to cover the inside of the upper frame 10 and the lower frame 12. A predetermined molding space 34, 34 is formed, respectively. Also, there, the squeeze plate 19 of the upper squeeze device 20 includes:
The sprue bar 35 is fixed by screwing or the like and stands upright substantially perpendicular to the pressing surface against the molding sand, and the tip end surface thereof is brought into contact with the pattern plate 30 in the molding space 34.

Then, in such a state, in the peripheral walls of the upper frame 10 and the lower frame 12, through the sand supply ports 36 opened vertically upward, respectively, into the molding spaces 34, 34. From the blow device 23, the casting sand 3
8 are supplied and filled. Further, after the molding sand 38 is filled, the squeeze plates 19, 19 of the upper and lower squeezing devices 20, 22 are displaced in a direction approaching each other with a predetermined pressure, and the molding sand 38 is compressed and filled. , Molding sand 38 is compacted in each molding space 34, and the upper mold and the lower mold as molds are respectively
It is molded.

After the molding of the upper and lower dies, the squeeze plates 19 and 19 of the upper and lower squeezing devices 20 and 22 are released from the mold, and the support 16 is moved to the position shown in FIG. It is turned to the turning position shown by the solid line. When the upper frame 10 and the lower frame 12 are separated from each other, the pattern plate 30 having the model 28 is die-cut from the upper die and the lower die.
After placing the core as necessary, again the upper frame 10 and lower frame 1
2 are superimposed, and the upper mold and the lower mold are pulled out onto the mold receiving device 26 by the mold removing device in a state where they are superimposed on each other, whereby the desired frameless mold is obtained. is there. In addition, a low friction inner layer 32 (see FIGS. 4 and 5) is generally provided on the inner peripheral surfaces of the upper and lower frames 10 and 12 in order to improve the mold removability of the molded mold. The inner peripheral surface 33 is provided with a removal taper that expands in the removal direction.

By the way, the squeeze plates 19, 19 mounted on the upper and lower squeeze devices 20, 22 of the mold making machine having such a structure have substantially the same structure as each other. It is shown in FIG. The squeeze plate 19 has a center plate 40 as a center portion having a substantially thick rectangular flat plate shape, and a rectangular frame shape or a rectangular cylindrical shape. An outer peripheral frame 42 as an outer peripheral portion disposed so as to surround the outer periphery of the outer peripheral frame 40. One surface of each of the central plate 40 and the outer peripheral frame 42 in the axial direction constitutes a wall surface of the molding space 34. A pressing surface that exerts a compacting force on the molding sand 38 is formed by the two pressing surfaces 44 and 46 in cooperation with each other. The central plate 40 and the outer peripheral frame 42 are formed of a metal material having sufficient strength so as to exert an effective compacting force on the molding sand 38.

The outer peripheral surface 48 of the central plate 40 is slightly smaller than the inner peripheral surface 50 of the outer peripheral frame 42, and the outer peripheral surface of the central plate 40 is Since a slight gap exists between the surface 48 and the inner peripheral surface 50 of the outer peripheral frame 42 over the entire circumference in the circumferential direction,
The central plate 40 and the outer peripheral frame 42 are used by the vertical squeeze device 2.
In the axial direction (the left and right direction in FIGS. 4 and 5), which is the driving direction by 0, 22, relative displacement can be made smoothly and mutually. In addition, on the back surface (the surface opposite to the pressing surface 44) of the central plate 40,
As shown in FIG. 5, an appropriate number of guide rods 51 are provided.
A guide bush 53 through which the guide rod 51 is inserted is fixed to the rear surface of the outer peripheral frame 42 while projecting in the axial direction of the central plate 40. Then, based on the axial guiding action of the guide rod 51 by the guide bush 53, the center plate 40 and the outer peripheral frame 42 are coaxially aligned with each other, and can be relatively displaced smoothly in the axial direction. . Further, the central plate 40 has a rectangular cross-section at the outer peripheral corner on the pressing surface 44 side over the entire circumference, and is fitted over the notch so as to be continuous over the entire circumference in the circumferential direction. The sealing member 52 is extended,
It is fixed to the center plate 40 by bolts. The outer peripheral portion of the seal member 52 projects outward from the outer peripheral surface 48 of the central plate 40 and comes into contact with the inner peripheral surface 50 of the outer peripheral frame 42, so that the casting between the central plate 40 and the outer peripheral frame 42 is performed. The entry of sand and the like is prevented.

Further, the outer peripheral surface 54 of the outer peripheral frame 42 is slightly smaller than the inner peripheral surface 33 of the upper and lower frames 10 and 12 into which the outer peripheral frame 42 is fitted.
2 is fitted, there is a slight gap between the outer peripheral surface 54 of the outer peripheral frame 42 and the inner peripheral surface 33 of the upper and lower frames 10 and 12 over the entire circumference in the circumferential direction. Reference numeral 42 allows the upper and lower frames 10 and 12 to be smoothly displaced relative to each other in the axial direction which is the driving direction of the upper and lower squeezing devices 20 and 22. Similarly to the central plate 40, the outer peripheral frame 42 has a rectangular outer peripheral portion on the pressing surface 46 side which is cut out in a rectangular cross section over the entire circumference. A seal member 56 extending continuously over the entire circumference is mounted and fixed to the outer peripheral frame 42 by bolts. The outer peripheral portion of the seal member 56 protrudes outward from the outer peripheral surface 54 of the outer peripheral frame 42 and comes into contact with the inner peripheral surface 33 of the upper and lower frames 10, 12, whereby the outer peripheral frame 42 and the upper and lower frames 10, 12 are formed. Intrusion of casting sand and the like into the gap is prevented. In addition, the sealing member 5
The members 2 and 56 are made of a resin or rubber material having appropriate elasticity so that the close contact with the outer peripheral frame 42 and the upper and lower frames 10 and 12 can be advantageously maintained with excellent durability. Is preferably adopted.

A rigid first connecting member 58 having a substantially gate shape is fixed to the back surface (the surface opposite to the pressing surface 44) of the central plate 40 by bolts at the tip portions of both legs 60,60. The distal end of the piston rod 66 of the first hydraulic cylinder mechanism 64 as the first driving means is fixed to the top plate 62 of the first connecting member 58 by bolts. The first hydraulic cylinder mechanism 64 is
A backward-acting cylinder mechanism, comprising a support member 6 of a molding machine main body.
8 is provided with a cylinder body 70 fixed to the
By controlling the supply and discharge of hydraulic oil to and from the cylinder body 70, the piston rod 66 is caused to protrude / retract. When the piston rod 66 of the first hydraulic cylinder mechanism 64 is caused to protrude, the driving force is transmitted to the center plate 40 via the first connecting member 58. 40 is pushed into the upper and lower frames 10 and 12,
The compacting force against is exerted. In addition, as is clear from this, the center plate 40
The pressing force exerted on the molding sand 38 by the pressing surface 44 can be directly controlled by adjusting the oil pressure supplied to the first hydraulic cylinder mechanism 64.

On the other hand, the back surface of the outer peripheral frame 42 (the pressing surface 46)
On the other side, a rigid second connection member 72 having a substantially gate shape is provided on both leg portions 74 and 7 via a rectangular frame-shaped support metal member 71 for supporting the guide bush 53.
4 is bolted at the tip. The top plate portion 76 of the second connection member 72 passes through the first connection member 58 fixed to the center plate 40, and is substantially the same as the top plate portion 62 of the first connection member 58. It extends in an orthogonal direction.
Then, the top plate 7 of the second connecting member 72 is opposed to the inner surface (the surface on the side of the center plate 40) of the top plate 62 of the first connecting member 58.
6 is brought into contact with the outer surface (the surface opposite to the center plate 40), the projecting driving force of the piston rod 66 by the first hydraulic cylinder mechanism 64 is applied to the first connecting member 58.
, The outer peripheral frame 42 is driven forward together with the central plate 40 and pushed into the upper and lower frames 10 and 12. In addition,
At the time of such forward drive, the pressing surface 46 of the outer peripheral frame 42 is maintained in a state of slightly projecting forward from the pressing surface 44 of the center plate 40.

Further, on the back side of the center plate 40, a second hydraulic cylinder mechanism 78 as a second driving means is disposed, and the cylinder body 80 is bolted to a center portion of the center plate 40. Have been. The piston rod 82 of the second hydraulic cylinder mechanism 78 is
0 (the direction in which the central plate 40 is pulled out of the upper and lower frames 10 and 12).
The two protruding distal ends are fixed to the top plate 76 of the second connecting member 72 fixed to the outer peripheral frame 42 by bolts. The second hydraulic cylinder mechanism 78 is a backward-acting cylinder mechanism, and controls the supply / discharge of hydraulic oil to / from the cylinder body 80 so that the piston rod 82 is caused to protrude / retract. . When the piston rod 82 of the second hydraulic cylinder mechanism 78 is retracted, the driving force is transmitted from the support metal member 71 to the outer peripheral frame 42 via the second connecting member 72. The outer peripheral frame 42 is pushed into the upper and lower frames 10 and 12 so that a compacting force against the molding sand 38 is exerted. Further, when the outer peripheral frame 42 is driven by the second hydraulic cylinder mechanism 78, the outer peripheral frame 42 is independent of the center plate 40 by separating the second connecting member 72 from the first connecting member 58. The center plate 40 is relatively driven forward.

The center plate 40 is held in a state where a predetermined pressing force is applied to the molding sand 38 by the driving force of the first hydraulic cylinder mechanism 64, or is fixed at a fixed position. By operating the second hydraulic cylinder mechanism 78 in the state of being held by holding the outer peripheral frame 42 further forward with respect to the central plate 40, the pressing surface 46 of the outer peripheral frame 42 A larger compaction force than the pressing surface 44 is exerted on the molding sand 38. As is apparent from this, the pressing force exerted on the molding sand 38 by the pressing surface 46 of the outer peripheral frame 42 reduces the hydraulic pressure supplied to the second hydraulic cylinder mechanism 78 while the center plate 40 is positioned. By adjusting, it can be controlled directly.

Therefore, in the mold making machine provided with the upper and lower squeezing devices 20 and 22 having the above-described structure, the pressure of the outer peripheral portion rather than the central portion of the pressing surface of the casting sand 38 by the squeeze plate 19, that is, the pressure. Foundry sand 3
8, the pressing force per unit area can be set large, whereby compaction strength can be advantageously obtained at the outer peripheral portion of the mold.

The transmission of the driving force to the outer peripheral frame 42 by the first hydraulic cylinder mechanism 64 is performed by the top plate portions 62 and 76 of the first connecting member 58 and the second connecting member 72 as described above.
In addition to the direct contact of the second hydraulic cylinder mechanism 78, for example, in a situation where the top plate portions 62, 76 of the first connecting member 58 and the second connecting member 72 are not in contact with each other, It can also be realized via

Hereinafter, the vertical squeezing device 20 as described above,
A specific example of the molding method using 22 will be described.

First, as described above, the pattern plate 30
After holding the upper and lower frames 10 and 12 superimposed in the axial direction with a horizontal state therebetween, as shown in FIG.
The mold spaces 34, 34 are formed by fitting the squeeze plates 19, 19 of the respective mold spaces 34, 34.
The molding sand 38 is supplied to and filled into the mold 34. In addition,
When the casting sand 38 is filled, the center plate 40 and the outer peripheral frame 42 constituting the squeeze plate 19
It is desirable that the relative positions are set so that the positions 4 and 46 are substantially flush. The pressing surface 46 of the outer peripheral frame 42 is
If the outer peripheral frame 42 protrudes greatly from the pressing surface 44 of 0, there is a possibility that it is difficult to obtain an effective compacting force without sufficiently securing a protruding stroke amount of the outer peripheral frame 42 in a subsequent process. 42 is retracted from the pressing surface 44 of the central plate 40, the outer peripheral frame 4
This is because the resistance force at the time of the projecting operation of 2 becomes large.

Next, as shown in FIG. 8, the first hydraulic cylinder mechanism 64 is operated to operate the first hydraulic cylinder mechanism 78 without operating the piston rod 82 in the second hydraulic cylinder mechanism 78. By applying the driving force of the cylinder mechanism 64 to both the central plate 40 and the outer peripheral frame 42, the central plate 40 and the outer peripheral frame 42 are integrally driven forward. Thus, the molding sand 3 filled in each molding space 34
A substantially constant pressure is applied to the end face of the squeeze plate 19 by the entire surface of the squeeze plate 19, and the first compaction step is performed. In the first compaction step, for example, by controlling the driving force of the first hydraulic cylinder mechanism 64 or the like, the pressure acting on the molding sand 38 is reduced to the pressure set on the central plate 40. Until it reaches.

Thereafter, as shown in FIG. 9, the piston rod 66 of the first hydraulic cylinder mechanism 64 is locked to prevent the displacement of the center plate 40, and the second hydraulic cylinder mechanism 78 is stopped. To apply a driving force from the second hydraulic cylinder mechanism 78 to the outer peripheral frame 42, thereby applying a greater driving force to the outer peripheral frame 42 than the center plate 40, and It is driven forward independently of the plate 40. As a result, the outer peripheral portion pressed by the pressing surface 46 of the outer peripheral frame 42 is closer to the end surface of the molding sand 38 filled in each molding space 34 than to the central portion pressed by the pressing surface 44 of the central plate 40. ,
The second stage compaction step is performed by applying greater pressure.

The moving stroke of the central plate 40 and the outer peripheral frame 42 in the first and second compaction steps can be controlled by the stroke (position) of the central plate 40 and the outer peripheral frame 42. However, the first hydraulic cylinder mechanism 64 and the second hydraulic cylinder mechanism 78
Is desirably controlled by the operating oil pressure (pressing force) in the step (1), whereby the target compaction force or the pressing force per unit area can be stably applied to the molding sand 38.

In the mold obtained through the first and second compaction steps as described above, a large pressing force is applied to the outer peripheral portions near the upper and lower frames 10 and 12 in the second compaction step. Is applied, the outer peripheral portion is compacted with a sufficiently large compacting force, so that a fully compacted mold can be stably manufactured as a whole. is there.

It is to be noted that the molding sand 3
8 and the ratio of the pressing force applied to the molding sand 38 by the pressing surface 46 of the outer peripheral frame 42 are determined by the area ratio of the pressing surface 44 of the central plate 40 to the pressing surface 46 of the outer peripheral frame 42 and the pattern plate. 30, the shape and size of the model 28,
Although it is appropriately set according to the shape and size of the upper and lower frames 10 and 20 and is not limited, in general, in order to obtain an effective compacting force over the entire mold, The pressing force (pressure) per unit area by the pressing surface 46 of the outer peripheral frame 42 is 1.5 to 2.5 with respect to the pressing force (pressure) per unit area by the pressing surface 44 of the central plate 40.
It is desirable to set the value to about twice.

In the above-described embodiment, the first-stage compaction step in which the center plate 40 and the outer peripheral frame 42 are integrally driven forward and the second-stage compaction step in which only the outer peripheral frame 42 is driven forward are described. Was adopted, but instead,
The operation of the first hydraulic cylinder mechanism 64 and the second hydraulic cylinder mechanism 78 is independently controlled until the target final pressure is reached from the start of the compaction process shown in FIG. It is also possible to separately drive the plate 40 and the outer peripheral frame 42 forward, and finally obtain a compaction completed state as shown in FIG. By adopting such a single-stage compaction process, the advance speed of the outer peripheral frame 42 having a large stroke amount is set to be greater than the center plate 40 from the beginning, and from the start to the end of compaction of the molding sand. Shortening of the required time can be realized.

Alternatively, a pre-compression step can be performed prior to the above-described compaction step. Specifically, first, at the start of the compaction process, as shown in FIG. 10, the second hydraulic cylinder mechanism 78 is locked while the piston rod 66 of the first hydraulic cylinder mechanism 64 is locked. By operating, only the outer peripheral frame 42 is
It is driven forward by a predetermined amount independently of zero. afterwards,
The outer peripheral frame 42 is temporarily separated from the pattern plate 30 by the second hydraulic cylinder mechanism 78 (the upper and lower frames 1).
(In the direction of withdrawing from the center plate 0, 12).
By returning the pressure surfaces 44 and 46 of the outer frame 42 to the initial state of being substantially flush with each other, as shown in FIG. 11, the state of starting the compaction process is returned. And then further,
For example, as shown in FIGS.
The target mold is obtained by performing the compacting step and the like consisting of the second step. If such a precompression step is adopted, the outer peripheral portion of the mold is preliminarily compacted before the compaction step, and in the compaction step, the outer peripheral frame 42 is retracted in the precompression step. After the casting sand has been filled into the cavity 84 formed in the outer peripheral portion of the mold,
Further, since the compaction is performed, a greater compaction force can be applied to the outer peripheral portion.

Although the embodiments of the present invention have been described in detail above, these are merely examples, and the present invention
By specific description in such a specific form,
It is not to be construed as limiting.

For example, in the above-described embodiment, the molding sand is blow-filled into the molding space through a sand supply port opened vertically upward while a pair of molds are superimposed in the horizontal direction. A concrete example of the present invention applied to a vertical blow molding machine in which molding sand is compacted by a pair of squeeze plates 19 and 19 arranged opposite to each other is shown. In a state in which the mold frames are vertically overlapped with each other, the molding sand is blow-filled into the molding space through a sand supply opening positioned in the horizontal direction, and a pair of squeeze plates 19 are vertically opposed to each other. , 19 can be applied to a horizontal blow molding machine or the like in which molding sand is compacted.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements and the like can be implemented in an embodiment,
It goes without saying that all such embodiments are included in the scope of the present invention without departing from the spirit of the present invention.

[0050]

As is apparent from the above description, in the frameless mold molding machine having the structure according to the present invention, the squeeze plate which is fitted into the opening of the mold and exerts a compacting force on the molding sand is provided. The outer peripheral portion can be independently displaced from the central portion, and the pressure exerted on the molding sand by the outer peripheral portion can be set independently of the pressure exerted on the molding sand by the central portion. By adjusting the pressure of the mold and the central part according to the shape and size of the mold, the condition of the mold sand, etc., it is possible to obtain a sufficient compaction force over the entire mold. Can be stably formed.

Further, according to the method of the present invention, the frameless molding machine having the structure according to the present invention is advantageously used, and the compaction pressures set respectively for the outer peripheral portion and the central portion are efficiently reduced. Therefore, it is possible to advantageously and stably produce a sufficiently compacted mold as a whole.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing the entire structure of a frameless mold making machine as one embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining one process of molding by the frameless mold molding machine shown in FIG.

FIG. 3 is an explanatory diagram for explaining a molding step following the step shown in FIG. 2;

FIG. 4 is a partially cutaway explanatory view showing an enlarged main part of the squeezing device in the frameless mold making machine shown in FIG. 1;

5 is a partially cutaway top view showing a main part of the squeezing device shown in FIG. 4;

FIG. 6 is a front view of a squeeze plate included in the squeeze device shown in FIG.

FIG. 7 is a process explanatory view for explaining a compaction operation of foundry sand by the squeeze device shown in FIG. 4;

FIG. 8 is an explanatory view of the compaction step following FIG. 7;

FIG. 9 is an explanatory view of the compaction step following FIG. 8;

FIG. 10 is a process explanatory view for explaining a pre-compression operation that can be employed in the present invention.

FIG. 11 is an explanatory view of a pre-compression step following FIG. 10;

[Explanation of symbols]

 Reference Signs List 10 upper frame 12 lower frame 19 squeeze plate 20 upper squeeze device 22 lower squeeze device 30 pattern plate 34 molding space 38 molding sand 40 center plate 42 outer peripheral frame 44 central pressing surface 46 outer peripheral pressing surface 64 first hydraulic cylinder mechanism 78 second Hydraulic cylinder mechanism

 ──────────────────────────────────────────────────続 き Continued on front page F-term (reference) 4E093 HB03 4E094 AA02 AA35

Claims (8)

[Claims] 1. A pattern plate is superimposed on one opening of a mold having a cylindrical frame shape, and a squeeze plate is fitted from the other opening of the mold to form the squeeze plate in the mold. A frameless mold mold in which a molding space is formed between the opposing surfaces of the pattern plate and the squeeze plate, and the squeeze plate is driven forward to the pattern plate side to compact the molding sand filled in the molding space. In the machine, the squeeze plate is divided into at least a central portion and an outer peripheral portion, and the central portion and the outer peripheral portion are independently displaceable to the pattern plate side and extended to the central portion and the outer peripheral portion. A frameless mold making machine characterized by comprising a drive means capable of setting each forward drive force independently of each other. 2. The squeeze plate, wherein the driving means is interposed between a support member fixedly disposed with respect to the mold and a central portion of the squeeze plate. A first drive mechanism for driving in the approach / separation direction, and a pattern plate interposed between a central portion of the squeeze plate and the outer peripheral portion of the squeeze plate; Approaching /
The frameless mold molding machine according to claim 1, further comprising: a second driving mechanism that is driven in a separating direction. 3. An outer peripheral portion of the squeeze plate is constituted by a plurality of outer peripheral divided bodies divided at a plurality of positions in a circumferential direction, and each of the outer peripheral divided bodies can be independently displaced forward on the pattern plate side. 3. The frameless mold making machine according to claim 1, wherein a forward driving force applied to each of the outer peripheral divided bodies by the driving means can be set independently of each other. 4. 4. After filling the molding space with molding sand by using the frameless mold molding machine according to any one of claims 1 to 3, the squeeze plate is driven forward to the pattern plate side, When molding the frameless mold by compacting the molding sand filled in the molding space, the central portion and the outer peripheral portion of the squeeze plate were simultaneously driven forward, and the central portion reached a preset pressure. After that, only the outer peripheral portion is further driven forward until the pressure reaches a preset value separately from the central portion, and the molding method of a frameless mold is further characterized. 5. After filling the molding space with molding sand using the frameless mold molding machine according to claim 1, the squeeze plate is driven to the pattern plate side. When molding a frameless mold by compacting the molding sand filled in the molding space, the pressure exerted on the molding sand by the squeeze plate is set separately in the central portion and the outer peripheral portion,
Start the forward drive of the central part and the outer peripheral part at the same time,
A method of molding a frameless mold, wherein the central portion and the outer peripheral portion are independently displaced until respective set pressures are reached. 6. After filling the molding space with molding sand by using the frameless mold molding machine according to any one of claims 1 to 3, the squeeze plate is driven forward to the pattern plate side, When molding the frameless mold by compacting the molding sand filled in the molding space, the outer peripheral portion of the squeeze plate is driven forward independently of the central portion, and the outer peripheral portion is pressed at a preset pressure. A molding method of a frameless mold, wherein only the central portion is driven forward while being held. 7. When molding a frameless mold according to the method according to claim 4 or 5, the outer peripheral portion of the squeeze plate is made to protrude from the central portion and is driven forward toward the pattern plate, and then the outer peripheral portion is formed. The part is once retracted to the side away from the pattern plate, and then, according to the method of claim 4 or 5,
A method of molding a frameless mold, wherein a central portion and an outer peripheral portion of the squeeze plate are driven forward toward the pattern plate. 8. The forward drive of the outer peripheral portion, which is performed prior to the forward drive of the squeeze plate according to the method of claim 4 when molding the frameless mold according to the method of claim 7. 8. The molding method for a frameless mold according to claim 7, wherein the pressure at the time and the pressure during the forward driving of the outer peripheral portion according to the method according to claim 4 or 5 are adjusted to different values. .