JPH05269546A - Molding device and molding method - Google Patents

Abstract

PURPOSE:To provide a molding device and a molding method, by which the suitable and sufficient molding compactness can be obtd. without adverse molding compactness at near the upper and lower surfaces, near the flask edge and the joining part between patterns, etc., in the mold. CONSTITUTION:At the lower part of the pattern 1, the base part 1b having height according to the compressive quantity of the molding sand 8 is arranged, and this pattern 1 is arranged on the pattern base board 2 or an auxiliary flask 3 is laid on the pattern base board 2, and a movable base board 4 cutting off the shape of the base part 1b (the shape of the lower end part of the pattern 1) is arranged in this auxiliary flask 3. Then the molding sand 8 charged into the molding flask 7 on the auxiliary flask 3 is pressurized from the lower part by the movable base board 4 and from the upper part by a squeeze head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold making apparatus and a method of using this apparatus, that is, a mold making method using this apparatus.

[0002]

2. Description of the Related Art As a mold for producing castings, a model surface plate on which a model is conventionally arranged is generally mounted on a table of a molding machine, a molding frame is placed on the model surface plate, and inside the molding frame, After casting the molding sand in the sand tank provided above, the molding sand is compressed by the squeeze head of the molding machine and the mold is clamped.After that, the model is extracted and the upper mold and lower mold are molded respectively. Is going.

However, according to the above conventional molding method,
When the molding sand is pressed with a uniform pressure by the squeeze head, the upper part of the model is close to the squeeze head, so mold clamping is good, but the upper part of the model surface plate far from the squeeze head (the parting surface side of the mold) The mold is not tightly clamped on the side surface of the model and the corner of the model platen and the model, and the corner (frame edge) between the model platen and the casting frame is the worst.

If there is such a part with poor mold clamping,
There is a possibility that the mold may be dropped during the die cutting, and in particular, the corner portions of the model surface plate and the model are chipped off, resulting in poor die cutting. In addition, if there is a part where mold clamping is poor and mold hardness is low, mold casting occurs in that part after pouring, and dimensional accuracy deteriorates, or flash occurs in the above-mentioned chipped corners In addition to degrading the quality of the steel, a lot of man-hours are required for casting finish such as removal of flash.

In order to improve the non-uniformity of mold clamping as described above, for example, a so-called multi-squeeze head type molding machine in which the squeeze head of the molding machine is divided into a plurality of pieces has been developed (for example, see Japanese Utility Model Publication No. 52-18969). Although a tentative effect has been obtained, such a squeeze method is still insufficient. For this reason, the Jolt squeeze method in which a Jolt was added to the above method was adopted, but although this method had a considerable effect in improving mold clamping, a pin for positioning the model surface plate and the casting frame, The bushes and other jigs and tools are greatly worn, and a lot of man-hours and costs are required for maintenance and noise and vibration due to jolts are generated, which requires a lot of labor and cost.

As a molding method for solving the problems of the squeeze method and the jolt squeeze method, there is a so-called pattern squeeze method in which the molding sand put in the casting frame is raised in the casting frame and pressed from below. It was developed (see Japanese Patent Publication No. 59-27266). According to this method, sand on the frame edge is tightly tightened and a considerable effect can be obtained, but in the case where multiple models are arranged on the model surface plate, so-called tightening of the so-called stripe part between the models still remains. There is a problem of being bad. The present invention can eliminate the above problems to obtain a mold of proper mold clamping, and a mold making apparatus that can contribute to the production of high quality castings with less occurrence of die casting and flashing, It is an object of the present invention to provide a method of using this apparatus, that is, a method of molding a mold using this apparatus.

[0007]

The present invention has been made in order to achieve the above object, and the device of the present invention has the same plane shape as the plane shape of the lower end of the model, On a model surface plate on which a model having a base having a height corresponding to the amount of compression of the model is arranged below, an auxiliary frame having the same height as the base of the model is placed, and the planar shape of the base of the model is set. It is characterized in that the movable platen having a planar shape other than the above is provided with a mechanism in which the movable platen is movably installed in the auxiliary frame through a rod penetrating the model platen.

The first method of the present invention as a method of using the above apparatus is to place the casting frame on the auxiliary frame of the above apparatus, insert the molding sand, and then raise the movable platen to move upward. The pressure is applied to the molding sand from below while the pressure is applied by the squeeze head, and the molding sand is pressed from above via the squeeze head. The second of the method of the present invention is the first above.
When carrying out the method of, further comprising placing a molding frame on the molding frame and charging the molding sand into the molding frame, and having a step of pressurizing the molding sand from above via a squeeze head. It is a feature.

[0009]

The device of the present invention has a movable platen that can move up and down in a plane shape excluding the plane shape of the base of the model. During molding, the casting is placed in the auxiliary frame and the casting frame placed on the auxiliary frame. After the sand is charged and filled, the movable platen is raised and the squeeze head above receives pressure to pressurize the molding sand in the casting frame, and the mold can be sufficiently clamped up to the shimmer portion of the model. Further, since the molding sand is pressed from above by the squeeze head, the mold is sufficiently clamped up to the upper surface of the model close to the squeeze head. Therefore, the mold clamping of the entire mold is properly and sufficiently performed.

[0010]

Embodiments of the present invention will be described below with reference to FIGS. FIG. 1 is a cross-sectional view of a main part of the mold making apparatus.
5 to 5 are cross-sectional views of main parts showing a molding process using this apparatus. The mold making machine of the present invention shown in FIG. 1 has the same shape as the plane shape of the lower end portion 1a of the model 1 and conforms to the compression amount of the foundry sand (determined experimentally to obtain a proper mold clamping). An auxiliary frame 3 having the same height as the height of the base 1b of the model 1 (that is, the compression amount of the foundry sand) is placed on the model surface plate 2 on which the model 1 having the height base 1b is arranged below. It is set up.

Further, inside the auxiliary frame 3, the model 1
The movable surface plate 4 having a planar shape other than the planar shape of the base portion 1b, that is, the planar through hole 4 of the lower end portion 1a of the model 1.
The movable surface plate 4 having a has the base portion 1b fitted into the through hole 4a, and is movable up and down to the upper surface of the auxiliary frame 3, that is, the lower end portion 1a of the model 1 via the rod 5 penetrating the model surface plate 4. It is provided.

Thus, the model surface plate 2 is mounted on a machine frame of a mold making apparatus (not shown), and the rod 5 is also a piston rod 5a and a frame body 5b of a cylinder (not shown). It goes up and down in the direction of the arrow. Further, a squeeze head is provided above the mold making apparatus so as to be vertically movable.

Next, one embodiment of a method of using the above-described mold making apparatus, that is, a method of making a mold using this mold making apparatus will be described. First, in molding a mold (upper mold), as shown in FIG. 2, a casting frame 7 suitable for molding by the model 1 is used, and the casting frame 7 is placed on the auxiliary frame 3 and then, From the sand tank (not shown), the molding sand 8 is put into the flask 7 and filled. Then squeeze head 6
Is lowered and applied to the upper surface of the molding sand 8.

Then, as shown in FIG. 3, the movable platen 4 is raised via the rod 5. Due to this rise, the squeeze head 6 receives upward pressure when the molding sand 8 is compressed, and the molding sand 8 is pressed from below. FIG. 3 shows a state in which the movable platen 4 is raised to the height of the auxiliary frame 3 and the molding sand 8 is compressed. Next, as shown in FIG. 4, the molding sand 8 is pressed from above via the squeeze head 6. FIG. 4 shows a state in which the molding sand 8 is compressed by this pressurization to a position slightly lower than the upper surface of the casting frame 7.

The upper surface of the molding sand 8 is slightly lower than the upper surface of the casting frame 7 as shown in FIG. 4 due to the compression by the squeeze head 6, but in the case of the above-mentioned upper mold making, this state may occur. However, in the case of the lower die, since it is inverted after the die is removed, the lowered portion after inversion becomes a cavity, which is inconvenient in casting production. Therefore, in the case of the lower mold making, as shown in FIG. 5, the filling frame 9 is further placed on the molding frame 7, the molding sand 8 is charged up to the upper surface of the molding frame 7 or more, and compressed by the squeeze head 6. After that, the upper surface of the molding sand 8 is set to be higher than the upper surface of the casting frame 7.

After the molding sand 8 charged in the casting frame 7 is compressed as described above, the movable platen 4 is held in the same position, and the squeeze head 6 is lifted to remove the pressing force. Die-cutting is performed in the same manner as in the past to complete the molding of the upper die and the lower die. The mold thus molded was able to perform proper and sufficient mold clamping up to the shim portion 1c between the models 1 and 1, together with the mold clamping in the upper and lower surfaces of the mold and in the vicinity of the frame edge.

[0017]

As described above, according to the present invention, it is possible to obtain proper and sufficient mold clamping for the entire mold from the vicinity of the upper and lower surfaces of the mold to the frame edge and the shim portion of the model. Therefore, the unevenness of mold clamping, the occurrence of mold bulging and the like due to insufficient mold flash, and the like, while improving the quality of the casting, it is possible to reduce the number of man-hours for the casting finish for removing and correcting the flash etc. It is effective.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an apparatus showing an embodiment of the present invention.

FIG. 2 is a sectional view of a key portion showing a first step of an embodiment of the method of the present invention.

FIG. 3 is a sectional view of an essential part, showing the same second step.

FIG. 4 is a sectional view of an essential part, showing the same third step.

FIG. 5 is a sectional view of a key portion showing a third step of another embodiment.

[Explanation of symbols]

 1 Model 1a Lower end 1b Base 2 Model surface plate 3 Auxiliary frame 4 Movable surface plate 5 Rod 6 Squeeze head 7 Casting frame 8 Foundry sand 9 Filling frame

Claims (3)

[Claims] 1. A model surface plate provided with a model having the same planar shape as that of the lower end portion of the model and having a base portion having a height corresponding to the amount of compression of the foundry sand under the model surface plate, An auxiliary frame having the same height as the base is placed, and a movable surface plate having a planar shape other than the planar shape of the base of the model is freely movable up and down in the auxiliary frame via a rod penetrating the model surface plate. A mold making apparatus comprising a mechanism installed in the mold. 2. A molding frame is placed on the auxiliary frame of the mold making apparatus according to claim 1, after which the molding sand is thrown in, and then the movable platen is raised and pressure is received by an upper squeeze head. A method of molding a mold, comprising: pressing the molding sand from below and pressing the molding sand from above via the squeeze head. 3. The method according to claim 1, further comprising a step of placing a molding frame on the molding frame, charging the molding sand into the molding frame, and pressurizing the molding sand from above via a squeeze head. Two
The method for molding a mold according to.