JPH0452044A - Manufacture of mold - Google Patents

Abstract

PURPOSE:To reduce pattern cost and molding man-hour and to shorten mold shake-out man-hour and sand removal man-hour by causing chemical reaction medium gas to flow into the mold completed with molding, continuously making the molds, locally heating, shifting flasks while curing and continuously making the molds and cores simultaneously. CONSTITUTION:While rotating the flask 2 by turning a turn table 10 for molding, molding sand for gas curing is continuously charged into cavity part in a sleeve pattern 1 for long length roll and mold 2 and into cavity part in a pipe 7 for gas vent from a continuous sand kneader. Master mold side and core side are rammed at the same time to continuously make the molds. At the time, when the molding in the flask almost is completed, by allowing the prescribed quantity of chemical reaction medium gas to flow through a gas supplying pipe 13, the mold 3 and the core 8 are cured with the chemical reaction only at the peripheral part of gas exhaust holes 14. Successively, the turn table 10 is descended by the range, which the mold cures, and the molding for the next flask is executed in the same way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a mold for a long roll applied to paper manufacturing machine parts and the like.

[Conventional technology]

Conventionally, when manufacturing long rolls and other general molds, a main mold corresponding to the outer shell of the product and a core corresponding to the hollow part are separately molded.

There are a wide variety of foundry sands that can be used to make molds for long rolls, etc., but there are issues with quality, man-hours, and cost.

Self-hardening sand is often used from the viewpoint of the environment and mold filling properties.

An example of a conventional mold manufacturing method using self-hardening molding sand is shown in FIGS. 3 and 4. Fig. 3 is a sectional view showing the main mold molding, and Fig. 4 is a cross-sectional view showing the core molding. Place it in the center of 2. In FIG. 4, after the core box 6 is installed in the core molding pit 4a, the core vent hole 7 is placed in the center of the core box 6 and fixed. .

Next, to explain its effect, in Fig. 3,
The main mold model 1a is a model of casting dimensions of the target long roll (
Processing allowance and amount of shrinkage are taken into consideration). After installing the casting flask 2 and the main mold model 1a in the main mold molding bit 4, the sand mixer 5
The self-hardening molding sand kneaded in step 1 is sequentially introduced into the gap between the main mold model J, a and the flask 2 along the outer periphery of the main mold model 1a. As a means of increasing the filling density of the mold, compaction is performed using a vibration vibrator or by hand; however, for boat fishing, after molding one mold from the lower part of the mold 2, The method is to set the steps and mold again.

When the molding to the required long roll length is completed, the mold 3
After leaving it for several hours to more than ten hours until it hardens, the main mold 1a is taken out from the mold 3.

On the other hand, in FIG. 4, after installing a core box 6 for a predetermined length and a gas venting pipe 7 in a core molding pit 4a, a core 8 is molded in the same manner as the mold 3 for the main mold. do.

[Problem to be solved by the invention]

By the way, in the conventional mold manufacturing method as mentioned above,
When manufacturing a mold for a long roll, it is necessary to manufacture a main mold model and a core box for the length of the target roll, which has the problem of significantly increasing model material costs and model manufacturing costs. .

In addition, when applying self-hardening foundry sand to long roll molds,
The main mold and core are molded separately, which not only increases the number of molding steps, but also makes it impossible to remove the mold until it hardens due to the chemical reaction between the binder and hardener in the mixed sand.
There are problems such as a loss of waiting time for the mold to harden and an increase in the number of man-hours for cutting out the model.

When using molding sand that uses a clay-based binder, the number of man-hours required to install and dry drying equipment for molds and cores increases, as well as the number of man-hours required for paring molds and removing sand from products, as well as environmental deterioration. be.

The present invention solves the above-mentioned problems, makes it possible to manufacture long roll molds using self-hardening sand, and reduces model costs, molding man-hours, mold disassembly man-hours, sand removal man-hours, etc. The aim is to provide a new method for manufacturing molds.

[Means to solve the problem]

In order to achieve the above object, the mold manufacturing method of the present invention includes:
A main mold modeled on a short sleeve for a long roll corresponding to the roll diameter and roll wall thickness is provided with air supply and exhaust means for chemical reaction medium gas, and the chemical reaction medium gas is vented into the mold after molding. , a long roll mold of the required length is manufactured by continuously molding the mold while curing the mold.

In addition, in order to heat the self-hardening foundry sand to be used and harden it quickly, a part of the sleeve model for the long roll is equipped with hot air or means for blowing hot air, and the formed mold is locally heated and hardened. However, it is also possible to gradually move the casting flask and continuously mold the mold and core of the required size at the same time to produce a mold of the required length.

As a means for blowing the hot air or warm air into the mold and the core, it is effective and preferable to use an air permeable mold for the whole or part of the sleeve model mold.

[Operation] The mold manufacturing method of the present invention described above uses a short sleeve as a model in place of the main mold model and the core box, instead of molding the main mold and core with a cutting machine as in the prior art. , the casting flask is set on the molding turntable installed in the main molding pit, the sleeve model for the long roll is set and supported in the center of the flask, and then the pipe for degassing the core is set. After setting it in the center of the sleeve model, while rotating the υ casting flask by rotating the turntable for molding, apply gas-hardening or self-hardening molding sand to the gap between the sleeve model and the flask, and between the sleeve model and the gas vent. The material is poured into the cavity of the pipe and molded using an automatic molding machine such as a vibrator to form a mold.

When the molding of the first flask is completed, in the case of gas-hardening foundry sand, a predetermined amount of chemical reaction medium gas is vented into the lower part of the sleeve model, and this chemical reaction medium gas permeates into the mold and core. , hardens by chemical reaction around the exhaust hole. In this case, the upper side of the sleeve model where the exhaust hole is not provided remains uncured.

In addition, when self-hardening molding sand is used, hot air or hot air is vented into the molding part for a predetermined period of time through a hot air or hot air ventilation mechanism provided in the sleeve model, and a part of the mold and core are shattered by this blowing. harden.

Next, when using molding sand of any of the above properties, place the next molding flask on top of the molded flask, lower the turntable a predetermined amount to the extent that the mold has hardened, and carry out the same procedure as described above. The method is used to form the legal frame.

Thereafter, continuous sand injection, continuous mold filling, and intermittent blowing of chemical reaction medium gas or hot air (warm air) are repeated and continued, and a main mold and core of the required length can be manufactured by simultaneous molding. In addition, in order to omit the exhaust hole of the sleeve model,
It is also preferable to use an air-permeable mold in the part of the sleeve model where hot air is blown.

〔Example〕

One embodiment of the present invention will be described below with reference to the drawings.
In Figure 1 showing the simultaneous molding work of the main mold and core, 1
2 is a sleeve model for a long roll, and 2 is a casting flask. A molding turntable 10 installed in a main molding bit 4 is rotated and raised to a predetermined height, and the flask 2 is set on the table. Next, the long roll sleeve model 1 is placed in the casting flask 2.
, and hold it by the support device 12. Next, the degassing pipe 7 of the core 8 is set at the center of the long roll sleeve model 1.

When the preparation for molding is completed, the rotary shaft 11 is rotated, and while the molding flask 2 is rotated by the rotation of the molding turntable 10, a continuous sand kneader (not shown) continuously mixes the long roll sleeve model 1 and the casting mold. Gas-hardening molding sand or self-hardening molding sand is poured into the gap of the frame 2 and the gap between the long roll model 1 and the gas venting pipe 7. The thrown gas-hardening molding sand or self-hardening molding sand is used to ram the main mold side and the core side simultaneously using an automatic molding machine (not shown) (vibrator-air rammer, etc.) to continuously form molds. .

When the molding of the first flask is almost completed, in the case of gas-hardening foundry sand, the chemical reaction medium gas is supplied through the chemical reaction medium gas supply pipe 13 connected to the long roll sleeve model IK. Vent the specified amount. The chemical reaction medium gas penetrates into the mold 3 and the core 8 through the jacket part 15 and the exhaust hole 14 of the sleeve model 1 for long rolls shown in the second figure, and the mold 3 and the core 8 penetrate around the exhaust hole 14. It is only cured by a chemical reaction. In this case, since the exhaust hole 14 is not provided on the upper side of the long roll sleeve model 1, the sand in this part can remain unhardened.

On the other hand, when self-hardening molding sand is used, when the first casting flask 2 is finished molding, a hot air generator (not shown) is used to mold the long roll sleeve model 1 in the same manner as described above. Hot air is ventilated for a predetermined period of time through a hot air supply pipe 13 attached to the chamber. Hot air sleeve model 1 for long rolls
It is blown into the mold 3 and the core 8 through the jacket part 15 and the exhaust hole 14.

Since self-hardening foundry sand such as Fran sand and Daical sand has the property of self-hardening due to dehydration, the mold 3 and core 8 harden even when hot air is blown into them.

Next, in each of the above cases, after setting the second flask 2 on top of the molding flask 2, the turntable 10 is lowered by a predetermined amount (the range where the mold has hardened), and the Shape the legal frame using the following method. Hardening has hardly progressed in the area of the long roll sleeve model 1 where the exhaust hole 14 is not provided, so even if new gas-hardening foundry sand or self-hardening foundry sand is poured, the area near the connection part of the flask 2 will remain unaffected. There are no problems caused by fat content.

Thereafter, the mold 3 and core 8 of the required length can be manufactured by repeating and continuing continuous sand injection, continuous mold filling, and intermittent chemical reaction medium gas ventilation or hot air blowing.

FIG. 5 shows an example in which an air-permeable mold 16 is used in the part of the sleeve model 1 for long rolls required for blowing hot air in order to omit the exhaust hole 14 of the sleeve model 1 for long rolls. .

Next, a specific example of implementing the present invention will be described.

A When using gas-curable foundry sand (Example 1) In the production of molds for long rolls for paper making machines, the gold box method (Isoquia) was used with gas-curable foundry sand,
While simultaneously molding the main mold and core, amine gas is vented to the lower part of the molded part and the gas is cured.
It was possible to mold the main mold and core of the required length at the same time.

(Example 2) As a result of adopting the 802 gas curing Bardock method (SO2 process) in the production of a mold for a long roll for a paper manufacturing machine, simultaneous molding of the main mold and core was realized.

B When using self-hardening foundry sand When manufacturing a mold for a long roll for a paper making machine using Fran sand shown in Table 1, applying the mold hardening conditions shown in Table 2 resulted in continuous simultaneous production of the mold and core. The molding could be realized, and the mold and core had the specified dimensions.

Table 1: Applicable sand formulation wt% Table 2: Curing conditions [Effects of the invention] Since the present invention is constructed as described above, it produces the effects described below.

In contrast to the conventional method of separately molding the main mold and core in mold manufacturing for long rolls, the present invention enables mold production by simultaneous molding of the main mold and core.

Furthermore, by using a short sleeve as a model, continuous molding of the main mold and core of the required length can be realized.

Therefore, the effects of greatly reducing model material costs and model manufacturing costs, reducing mold manufacturing man-hours, shortening casting manufacturing time, and reducing product finishing man-hours are significant.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing the state of simultaneous molding of the main mold and core according to the present invention, FIG. 2 is a partially cutaway enlarged cross-sectional view of the sleeve model for a long roll according to the present invention, and FIG. FIG. 4 is a vertical cross-sectional view showing conventional main mold molding, FIG. 4 is a vertical cross-sectional view showing conventional core molding, and FIG. 5 is a sleeve model for a long roll using a partially air-permeable mold according to the present invention. A cross-sectional view is shown. DESCRIPTION OF SYMBOLS 1... Sleeve model for long roll, 1a... Model for main mold, 2... Casting flask, 3... Mold, 4... Bit for main mold making, 4a... Core making Bit, 5... Sand kneading machine, 6... Core/sheath for core, 7... Pipe for degassing, 8... Core, 9... Cavity, 1o... Turn for molding. Table, 11...Rotating shaft, 12...
・Support device, 13...Chemical reaction medium gas or hot air supply pipe 4...Exhaust hole, 5...Jakerat part, 6...Air delivery mold part.

Claims (3)

[Claims] (1) In a mold manufacturing method in which a short sleeve corresponding to the roll diameter and roll wall thickness is used as a model and a mold for a long roll is manufactured using the model, the chemical reaction of the gas-hardening molding sand used as the molding sand In order to realize instant hardening, the sleeve model is equipped with air supply and exhaust means for chemical reaction medium gas, and while the chemical reaction medium gas is vented to the mold in the completed molding area and cured, the main mold and core are continuously moved. A mold manufacturing method characterized by simultaneous molding and making a mold of a predetermined length. (2) Using a short sleeve corresponding to the roll diameter and roll wall thickness of a long roll as a model, the main mold and core are continuously molded at the same time, and the main mold and core of a predetermined length are manufactured as one unit. In the long roll mold manufacturing method, self-hardening molding sand is applied as the molding sand, and in order to realize early hardening of the self-hardening molding sand, the sleeve model is provided with a hot air or a mechanism for venting hot air, Venting hot air or hot air to the completed part,
A mold manufacturing method in which molds and cores of required dimensions are continuously manufactured by gradually moving a casting flask while partially curing the mold and core. (3) The mold manufacturing method according to claim 2, wherein an air-permeable mold is used for the entire or part of the sleeve model mold as a means for blowing hot air or hot air into the mold and the core to harden the mold.