JPH057980A - Manufacture of long-sized roll mold and core - Google Patents

Abstract

PURPOSE:To reduce molding man-hour by using a sleeve provided with venting holes corresponding to the diameter and thickness of a long-sized roll, as a pattern and successively molding mold and core at the same time while sucking the air from the sleeve and reducing the pressure. CONSTITUTION:Pipes 7 for gas vent in the core 6, the sleeve pattern 1 and flasks 2 are concentrically arranged and self-curing molding sand is packed into a gap part between the pipes 7 for gas vent in the core 6 and the sleeve patterns 1 and into the gap part between the sleeve patterns 1 and the flasks 2. The air pressure in the sleeve patterns 1 is sucked, and after curing the molding sand, the pipes 7 for gas vent in the core 6 and the flasks 2 are shifted downward and the sleeve patterns 1 are drawn out from the mold. By successively molding the master mold and the core at the same time while sucking the air to reduce the pressure in the constitution, the molding man-hour is reduced. Further, since the short length of the sleeve patterns in axial direction is used, the pattern cost is reduced and shortening the time of delivery for the casing can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold (main mold) and a core manufacturing method used for casting a long roll in a papermaking machine part or the like.

[0002]

2. Description of the Related Art When a general mold including a long roll is manufactured, a main mold corresponding to an outer shell of a product and a core corresponding to a hollow portion are separately molded to manufacture a mold. In FIG. 3, after the flask 2 is installed in the current main mold making pit 4a, the main mold 1a is placed at the center of the flask 2.

In FIG. 4, after the core box 8 for the core is installed inside the core-forming pit 4b, the pipe 7 for degassing the core is placed at the center of the core box 8 for the core. Now, the organic self-hardening foundry sand and the inorganic self-hardening foundry sand have the property of self-hardening by the chemical reaction of the binder and the hardener. In continuous mold and core production, casting sand requires a long pot life (a time capable of holding about 90% of the properties of sand immediately after kneading) and a short hardening time. However, with the current technology, it takes a considerably long time before the molded sleeve model can be removed (moved). Therefore, both the main mold model and the core core box require the required length. Make a model using a model.

Next, a conventional mold making method will be described with reference to FIGS. In FIG. 3, the master model 1a has the actual size of the target long roll. After installing the flask 2 and the main mold 1a in the current main mold pit 4a,
The self-hardening molding sand kneaded by the sand kneading machine 5 is put into the space between the main mold model 1a and the casting frame 2. As a means for increasing the packing density of the mold 3, a vibration vibrator or manual work is performed to make the mold by squeezing.

Generally, the molding is started from the bottom of the molding frame 2, and when the molding for one frame is completed, the molding frame 2 of the second stage is set and the molding of the second stage is carried out by the above-mentioned method. . After that, molding is repeatedly performed to a required length, and when the molding is completed, the mold 3 is left for several hours to ten and several hours, and then the main mold model 1a is taken out from the mold 3. On the other hand, in FIG. 4, the self-hardening molding sand kneaded by the sand kneading machine 5 is put into the space between the core box 8 for cores of a predetermined length and the degassing pipe 7, and the vibration vibrator or the hand is used. After the molding sand is solidified by working to make the core 6, the core 6 is left for several hours to ten and several hours in the same manner as the main mold, and after confirming the hardening, the core 6 is taken out from the core box 8 for core.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
There are the following problems. (1) When manufacturing a long roll mold, it is necessary to manufacture the main mold model and the core box for the length of the target roll, and therefore the model material cost and the model manufacturing cost are significantly high. (2) In self-hardening molding sand, there is a time loss waiting for the mold to cure. (3) Since the mold and the core are separately molded, the number of molding processes increases. (4) The man-hours for removing the main mold and the core are required.

An object of the present invention is to solve the above problems in the prior art and to provide a simultaneous molding method for a mold (main mold) and a core by self-hardening molding sand.

[0008]

[Means for Solving the Problems] A sleeve with suction holes corresponding to the roll diameter and roll thickness of a long roll is used as a model,
The mold and the core are continuously molded simultaneously while suctioning under reduced pressure from the sleeve.

[0009]

[Function] The core degassing pipe, the sleeve model, and the casting frame are arranged concentrically, and the space between the core degassing pipe and the sleeve model and the space between the sleeve model and the casting frame are arranged. Then, self-hardening molding sand is filled in, and the sleeve model is suctioned under reduced pressure. After the molding sand is hardened, the core degassing pipe and the casting frame are moved downward to remove the sleeve model.

By repeatedly introducing and hardening the molding sand, the mold for the long roll and the core are simultaneously molded.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. 1 is a sleeve model having inner and outer diameters corresponding to the inner and outer diameters of the long roll to be cast, and shortening the axial length to a fraction of the length of the long roll. , Has a hollow jacket inside, has fine suction holes 15 on the inner and outer peripheral surfaces, and connects a suction pipe 13 to the upper part.

The mold making turntable 10 installed in the main mold making pit 4 having a depth suitable for the length of the long roll is lifted to a height corresponding to the axial length of the sleeve model 1. Position. First (bottom) flask 2
Is set on the molding turntable 10. The sleeve model 1 is set in the center of the flask 2 and held by the support device 12, and then the core degassing pipe 7 is set in the center of the sleeve model 1. When the preparation for molding is completed, the depressurizing device (not shown) is operated to suck the sleeve model 1 under reduced pressure through the suction pipe 13. Next, while rotating the molding turntable 10, the self-hardening molding sand is fed from the sand kneading machine 5 between the flask 2 and the sleeve model 1 and between the sleeve model 1 and the core degassing pipe 7. Continuously add to the void. The self-hardening molding sand that was put into the molding machine (vibrating vibrator, sand rammer, etc.) not shown
At the same time, the main mold side and the core side are simultaneously rammed or vibrated to continuously mold the mold 3 and the core 6.

The moisture contained in the binder and the moisture produced during the curing reaction of the molded self-hardening molding sand are decompressed through the suction hole 15 and the jacket 14 of the sleeve model 1 connected to the decompression device. Since it is sucked, the mold 3 and the core 6
The curing reaction is accelerated, and as a result, it is possible to secure the strength that allows the model 1 to be removed from the mold in a short time. Next, the molding turntable 10 is lowered by one frame, and the second flask 2 is set on the first flask 2. Thereafter, the continuous casting of the self-hardening molding sand and the continuous ramming are continuously performed so that the casting mold 3 having the required length is
Simultaneously molding the core 6 and the core 6 to manufacture the mold and the core.

Next, specific examples of the present invention will be described. The mold and core of the roll for a papermaking machine were molded by the manufacturing method of the present invention.

[0015]

[Table 1]

Under the self-hardening molding sand and reduced pressure suction conditions shown in Table 1, the mold and the core are continuously simultaneously molded, and molding is completed.
Vacuum suction was performed until 0 minutes, and the mold and core were removed from the mold about 60 minutes after completion of molding. When the mold size and the size of the long roll casting were measured, a good long roll mold according to the casting plan could be obtained.

[0017]

The method for producing a long roll mold and core according to the present invention includes a turntable that can be rotated and moved up and down, and inner and outer diameters corresponding to the inner and outer diameters of the long roll to be cast. A sleeve model having an axial length shorter than that of the same length roll, a decompression suction mechanism communicating with suction holes provided on the inner and outer peripheral surfaces of the sleeve model, and the inner diameter of the core as the pipe outer diameter. Provided with a core degassing pipe, and a casting frame divided in the axial direction with the mold outer diameter as the casting frame inner diameter, and supporting the sleeve model concentrically with respect to the turntable from above,
A core degassing pipe and a casting frame are concentrically placed on the turntable with a sleeve model sandwiched between them, and the turntable is rotated to provide a space between the core degassing pipe and the sleeve model and between the sleeve model and the casting mold. The self-hardening molding sand is put into the space between the frames from above to a predetermined height, and after the molding sand is hardened, the turntable is lowered together with the core degassing pipe and the molding frame, and the casting is performed. The following effects can be obtained by connecting the second molding frame above the frame and repeating the steps of charging and hardening the molding sand, lowering the turntable, and connecting the molding frame. (1) By continuously connecting the main mold and the core at the same time, it is possible to greatly reduce the number of molding processes. (2) Since a sleeve model having a short axial dimension is used instead of the actual model, the model cost can be greatly reduced. (3) Therefore, the delivery time of the casting can be shortened.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a final stage of manufacturing a mold and a core according to the present invention.

FIG. 2 is a side view in which a part of the sleeve model shown in FIG. 1 is cut away.

FIG. 3 is a vertical cross-sectional view showing a conventional mold making process.

FIG. 4 is a vertical cross-sectional view showing a conventional core molding.

[Explanation of symbols]

 1 Sleeve Model 2 Mold Frame 3 Mold 5 Sand Kneader 6 Core 7 Core Degassing Pipe 10 Molding Turntable 12 Supporting Device 13 Suction Pipe

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B22C 15/28 8315-4E

Claims (1)

Claims: 1. A turntable that can rotate and ascend / descend, and has an inner / outer diameter corresponding to the inner / outer diameter of a long roll to be cast. A short sleeve model, a decompression suction mechanism communicating with suction holes provided on the inner and outer peripheral surfaces of the sleeve model, a core degassing pipe whose inner diameter is the pipe outer diameter, and a mold outer Provided with a casting frame divided into an axial direction with a casting frame inner diameter, and supporting the sleeve model concentrically to the turntable from above,
A core degassing pipe and a casting frame are concentrically placed on the turntable with a sleeve model sandwiched between them, and the turntable is rotated to provide a space between the core degassing pipe and the sleeve model and between the sleeve model and the casting mold. The self-hardening molding sand is put into the space between the frames from above to a predetermined height, and after the molding sand is hardened, the turntable is lowered together with the core degassing pipe and the molding frame, and the casting is performed. A method for producing a long roll mold and core, characterized in that a second casting frame is connected above the frame, and casting sand is charged, hardened, the turntable is lowered, and the casting frame is connected repeatedly.