JP3342673B2 - Mold molding apparatus and molding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus and a molding method, and more particularly to a molding apparatus and a molding method capable of obtaining sufficient hardness not only on the back side of the mold but also on the model side.

[0002]

2. Description of the Related Art Casting sand charged in a casting frame placed on a model surface plate is placed on the surface of the model surface plate (hereinafter referred to as the model surface side).
Various techniques have been disclosed for squeezing from both sides of the surface and the opposite side (hereinafter referred to as the back side). Each of these aims to mold a mold having sufficient hardness not only on the back side of the flask but also on the model side, and various devices have been devised mainly by means of pressing from the model side. . For example, Japanese Patent Publication No. 47-356
According to No. 50, the casting frame 4 is sent to the filling position by the cylinder 8, and the filling frame 3 is pushed up. at the same time,
It is fed to a predetermined position by the piston 7 of the press table to secure the amount of molding sand compression on the model surface side. According to JP-A-56-1245, the lower filling frame 10 is projected upward by the drive unit 12 with respect to the model plate 7 or the compression table 4 to secure the amount of compression on the model surface side. I have.

[0003]

However, in the conventional method represented by the above, it is necessary to operate the filling frame by a special device, which leads to an increase in equipment cost and a troublesome repair due to the complexity of the device. I cannot avoid it. SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to enable squeezing from both sides with a simple apparatus and method.

[0004]

In order to solve the above-mentioned problems, a mold making apparatus according to the present invention has a filling frame and an inner surface along the inner surface of the filling frame. A cast flask placed thereon, a base mounted on the fill frame and the fill frame along the inner surface of the cast frame so as to be movable up and down relatively to the fill frame, and an upper surface of the base A model platen fixed to the base, a lower pressurizing head supporting the base from below, and an upper pressurizing head located above the casting flask, wherein the base is a stopper portion. And a lower end of the filling frame forms a bottom surface capable of contacting the upper surface of the stopper portion, and the filling frame has a pin member having a rod portion and a head portion formed at the lower end of the rod portion. The rod portion has an upper end fixed to the filling frame, extends downward, penetrates a stopper portion of the base, and the head portion is The lower surface and engaged, characterized by further comprising a compressible elastic member interposed between said Sheng frame and the upper surface of the base of the stopper portion.

In practicing the present invention, at least one of the lower pressure head and the upper pressure head can be vertically movable. Further, the compressible elastic member may be a compression coil spring, and the compression coil spring may be arranged such that a rod portion of the pin member is used as a central axis of the coil.

[0006] In the mold making method according to the present invention, the vertical distance between the plate surface of the model platen and the lower end surface of the flask is determined by using the mold molding apparatus described above. A space formed by the inner surface of the casting frame, the inner surface of the filling frame, and the upper surface of the model platen while being held at a distance equal to the vertical direction between the upper surface of the stopper portion of the base and the upper surface. Until the upper pressurizing head is lowered or the lower pressurizing head is raised until the position of the surface of the model platen coincides with the position of the lower end surface of the casting frame in the vertical direction. ,
Alternatively, the casting sand is squeezed from the surface of the model surface plate by lowering the upper pressure head and raising the lower pressure head.

[0007] By adjusting the length of the rod portion of the pin member, it is possible to adjust the compression allowance of the foundry sand when squeezing from the surface of the model surface plate. Also,
The length of the rod portion of the pin member may be the sum of the compression allowance at the time of squeezing from the surface of the model surface plate and the length determined by the mold making apparatus.

[0008]

The mold forming apparatus according to the present invention is a very simple apparatus provided with a compressible elastic member such as a compression coil spring and a pin member. This utilizes the restriction by the pin member of the compression allowance. Using this device, make the vertical distance between the surface of the model platen and the lower end of the casting frame equal to the vertical distance between the bottom surface of the filling frame and the upper surface of the stopper of the base. In a state where the molding sand is filled in the space defined by the inner surface of the casting frame, the inner surface of the filling frame, and the upper surface of the model surface plate, and the position of the surface of the model surface plate is By lowering the upper pressing head, or lowering the lower pressing head, or lowering the upper pressing head and lowering the pressing head, the molding sand is removed not only on the back side until the position of the end face matches in the vertical direction. , Squeeze from the model side. Thus, when one step from the filling of the molding sand to the release is completed, the molding apparatus automatically restores to a state in which the molding sand can be filled by the cooperative action of the elastic member and the pin member. As described above, squeezing from both sides of the back surface and the model surface can be automatically and repeatedly performed by a simple device, so that equipment costs and repair costs can be significantly reduced. The compression allowance of the molding sand during squeezing from the model surface side can be adjusted by changing the length of the rod portion of the pin member.

[0009]

FIG. 1 is a block diagram showing an embodiment of the present invention.
A description will be given based on FIG. As shown in FIG. 1, the mold making apparatus according to the present invention includes a filling frame 1 and a support portion 1 a having an inner surface along the inner surface of the filling frame 1 and forming an upper edge of the filling frame 1.
A casting frame 2 placed on the upper surface of the base, a base 3 movably fitted up and down relative to the filling frame 1 and the casting frame 2 along the inner surfaces of the filling frame 1 and the casting frame 2, A model surface plate 4 fixed to the upper surface of the base 3, a lower pressure head 5 for supporting the base 3 from below, and an upper pressure head 6 located above the flask 2 are provided.

The lower pressure head 5 is supported from below by a squeeze cylinder 7 which operates up and down by hydraulic pressure. The upper pressure head 6 and the sealed end of the cylinder portion 8 a of the stopper cylinder 8 are both fixed to the lower surface of the upper frame 9. The lower end of the rod portion of the piston 8b of the stopper cylinder 8 is opposed to the upper surface of the upper edge 2a of the flask 2 so as to be able to abut. Cylinder part 8a of stopper cylinder 8
The upper chamber of the piston 8b is connected to a hydraulic path (not shown) via a hydraulic pressure switching valve 10, and by closing the valve 10, the position of the piston 8b is fixed.
By opening 0, the fixation of the piston 8b is released.

The base 3 has a stopper 3a formed so as to protrude in the lateral direction, and the lower end of the filling frame 1 forms a bottom surface 1b which can contact the upper surface of the stopper 3a. The upper end of the rod part 11a of the pin member 11 is fixed to the support part 1a of the filling frame 1. The rod portion 11a extends downward and penetrates the stopper portion 3a of the base 3, and the upper surface of the head portion 11b formed at the lower end thereof is engaged with the lower surface of the stopper portion 3a. Further, the rod portion 11a of the bin member 11 is provided between the support portion 1a of the filling frame 1 and the upper surface of the stopper portion 3a of the base 3.
A compression coil spring 12 serving as a compressible elastic member is provided around the center of the body. The stopper 3a, the pin member 11, and the compression coil spring 12 are
Usually, at least one each is provided at each of the four corners of the filling frame 1, but only the compression coil spring 12 may be additionally provided.

At the time of molding by using the mold molding apparatus of the present invention, first, the board surface 4a of the model
Distance between the lower surface of the lower edge portion 2b or the surface of the model surface 4a and the upper surface of the supporting portion 1a of the filling frame 1, that is, a compression allowance (squeeze margin) when squeezing on the model surface side. )
Must be kept equal to the distance between the bottom surface 1b of the filling frame 1 and the upper surface of the stopper 3a of the base 3 (indicated by H in the drawing). This is the pin member 11
The length of the rod portion 11a is set to a predetermined size, and
This can be achieved by the repulsive force of the compression coil spring 12 interposed between the lower surface of the support portion 1a and the upper surface of the stopper portion 3a of the base 3.

Next, a molding process by the present molding apparatus will be described with reference to FIG. FIG. 2A shows a first step, in which casting sand 13 is charged into the casting flask 2. As described above, the apparatus in this step includes the bottom 1b of the filling frame 1 and the stopper 3 of the base 3.
The distance from the upper surface of a is equal to the compression allowance at the time of squeezing from the model surface side, and is kept at a value of H. In the apparatus in this state, molding sand 13 is filled into a space formed by the inner surface of the casting frame 2, the inner surface of the filling frame 1, and the upper surface of the model platen 4. In this case, the molding sand 13 to be filled is
Are raised, including the amount corresponding to the compression allowance by squeezing from the back side, which is the next step.

FIG. 2B shows a second step in which squeezing is performed from the back side. That is, the hydraulic pressure switching valve 10 is opened, the upper chamber of the cylinder portion 8 a of the stopper cylinder 8 is opened, the squeeze cylinder 7 is raised, and the casting sand 13 is directed toward the upper pressing head 6 by the lower pressing head 5. Squeezing from the back side is performed by compressing. In this case, the lower end of the piston 8b of the stopper cylinder 8 is in contact with the upper surface of the upper edge 2a of the flask 2.

FIG. 2C shows a third step in which squeezing is performed from the model surface side. That is, the hydraulic switching valve 10
Is closed, the position of the piston 8b of the stopper cylinder 8 is fixed, and the squeeze cylinder 7 is further raised by a distance H. Since the position of the casting flask 2 is fixed, the filling frame 1 does not move, 3 rises with respect to the filling frame 1 and the base 3
The upper surface of the stopper portion 3a comes into contact with the bottom surface 1b of the filling frame 1, and the ascent of the base 3 is stopped. At this time, the surface 4a of the model surface plate 4 rises by the distance H with respect to the filling frame 1 in the same manner. Thus, the surface 4a of the model base 4 and the lower surface of the lower edge 2b of the casting flask 2 are at the same level, and the squeezing of the compression allowance H from the model surface is completed.

FIG. 2D shows a fourth step in which the state of the stopper cylinder 8 is maintained in the third step and the squeeze cylinder 7 is lowered. The frame 1 is raised, the mold is separated from the model platen 4, and the mold release is completed. The figure shows the switching valve 10 in preparation for the next step.
Indicates an open state.

In the above embodiment, both the squeeze from the back side and the squeeze from the model side are performed by raising the lower pressurizing head 5 with the position of the upper pressurizing head 6 fixed. The squeeze from the lower pressurizing head 5 can be performed by fixing the position of the lower pressurizing head 5 and lowering the vertically movable upper pressurizing head 6. 6 can be lowered and squeezed from the model side by raising the lower pressure head 5.

The compression allowance H from the model side is determined by the pin member 11.
Can be adjusted by changing the length of the rod portion 11a. In other words, the rod portion 1 of the pin member 11
The length of 1a is the compression allowance H from the model surface side and the rod part 1
It is equal to the sum of the length from the fixed end located at the upper end of 1a to the bottom surface 1b of the filling frame 1 and the thickness of the stopper 3a of the base 3 (the latter two values are determined for each mold making apparatus). .

The opening and closing of the hydraulic pressure switching valve 10, the raising, lowering and raising amounts of the squeeze cylinder 7 and the upper pressurizing head 6,
The descending amount and the like can be controlled by automatic control means (not shown) according to respective preset programs.

In the above embodiment, a metal compression coil spring is used as the compressible elastic member. Instead, a cylindrical rubber spring, a pneumatic spring in which air is sealed in a sealed hollow rubber. Or the like, or the characteristics of each spring can be set as appropriate. Further, in the above-described embodiment, hydraulic pressure is used to operate the cylinders, but compressed air may be used instead of hydraulic pressure.

As described above, according to the present invention, squeezing from both sides of the back surface and the model surface can be performed by an extremely simple mold making apparatus having a compressible elastic member such as a compression coil spring and a pin member. it can. When one step from the filling of the molding sand to the mold release is completed, the molding apparatus automatically restores to a state where the molding sand filling can be started by the cooperative action of the elastic member and the pin member. Can be repeated. In this way, according to the mold making apparatus of the present invention, equipment costs and repair costs can be significantly reduced as compared with the conventional apparatus.

[Brief description of the drawings]

FIG. 1 is a schematic vertical sectional view of a mold making apparatus according to the present invention.

FIG. 2 is a schematic vertical sectional view of a mold forming process performed by the mold forming apparatus shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fill frame, 1a ... Bearing part, 1b ... Bottom surface, 2 ... Cast frame, 2a
... upper edge, 2b ... lower edge, 3 ... base, 3a ... stopper, 4 ... model surface plate, 4a ... board surface, 5 ... lower pressure head, 6
... upper pressure head, 7 ... squeeze cylinder, 8 ... stopper cylinder, 9 ... upper frame, 10 ... hydraulic switching valve,
11: Pin member, 11a: Rod portion, 11b: Head portion, 12: Coil spring, 13: Foundry sand, H: Compression allowance.

Claims (7)

(57) [Claims] 1. A filling frame, a casting frame having an inner surface along the inner surface of the filling frame and mounted on an upper surface of the filling frame; A base movably fitted up and down relative to the filling frame and the molding flask, a model surface plate fixed to an upper surface of the base, and a lower pressure head for supporting the base from below And an upper pressure head located above the casting frame, wherein the base has a stopper portion, and a lower end of the filling frame can contact an upper surface of the stopper portion. Forming a bottom surface, and the filling frame includes a pin member having a rod portion and a head portion formed at the lower end of the rod portion. The rod portion has an upper end fixed to the filling frame and extends downward. The head portion penetrates through the stopper portion of the base, the head portion engages with the lower surface of the stopper portion, and further the upper frame and the upper surface of the stopper portion of the base. Characterized by comprising a compressible elastic member interposed between the mold forming apparatus. 2. The mold making apparatus according to claim 1, wherein at least one of the lower pressure head and the upper pressure head is vertically movable. 3. The molding apparatus according to claim 1, wherein the compressible elastic member is a compression coil spring. 4. The mold making apparatus according to claim 3, wherein the compression coil spring is arranged with a rod portion of the pin member as a center axis of the coil. 5. The vertical distance between the plate surface of the model platen and the lower end surface of the casting frame is defined as the vertical distance between the bottom surface of the filling frame and the upper surface of the stopper portion of the base. In a state in which the molding sand is filled in a space formed by the inner surface of the casting frame, the inner surface of the filling frame, and the upper surface of the model surface plate, and the surface of the model surface plate Until the position of the upper pressure head coincides with the position of the lower end surface of the flask in the up-down direction, or the lower pressure head rises, or the upper pressure head lowers and the lower pressure head. The method according to claim 1, wherein the molding sand is squeezed from the surface of the model platen by raising the mold sand. 6. The compression allowance of the molding sand at the time of squeezing from the surface of the model platen is adjusted by adjusting the length of the rod portion of the pin member. 3. The method of molding a mold according to item 1. 7. The length of the rod portion of the pin member is a sum of a compression allowance at the time of squeezing from the surface of the model platen and a length determined by the mold making apparatus. The molding method according to claim 6.