MX2008001897A - Method and device for molding cope and drag. - Google Patents

Abstract

A method and a device for molding a cope and a drag capable of preventing a warpage from occurring on molded cope and drag or a match plate from being damaged. In the method, the match plate (1) is held by upper and lower flasks (2, 3), and upper and lower squeeze means (4, 5) are inserted into the opening parts of the upper and lower flasks without match plate to form cope and drag molding spaces. Next, a foundry sand is filled in these cope and drag molding spaces and the upper and lower squeeze means are advanced to the match plate to squeeze the foundry sand in the cope and drag molding spaces for molding the cope and drag. The method is characterized in that the upper and lower squeeze means are advanced to the match plate while a difference between an upper squeeze force and a lower squeeze force is maintained within a predetermined allowable range.

Description

METHOD FOR BUILDING UPPER AND LOWER MOLDS AND A RESPECTIVE APPARATUS FIELD OF THE INVENTION This invention relates to the method for constructing upper and lower molds and a respective apparatus. BACKGROUND OF THE INVENTION Some methods for manufacturing upper and lower molds are publicly known. One of them comprises the steps for holding an adjustment plate between the box and the drag flasks, by inserting pressure means in the respective openings of the box and drag flasks, whose openings are opposite to the adjustment plate, therefore defining the upper and lower molding spaces, then providing molding sand to the lower and upper molding spaces, and causing the upper and lower pressing means to move forward to the adjustment plate to press the molding sand into the upper spaces and lower molding to obtain upper and lower molds without flasks. (See International Publication No. O2005 / 05825 Al).

However, the conventional method for constructing upper and lower molds comprising the above steps can cause differences between the pressures applied to the upper and lower pressing means when the pressure means move forward towards the adjustment plate, this is caused due to differences in forward speeds or pressures for the upper and lower pressure means, to the difference of the patterns on both sides of the adjustment plate, to the difference of the thickness of the upper and lower molds, to the Density difference of the molding sand filling the upper and lower molding spaces, etc. Therefore, the upper and lower pressures provided by the means of transport, whose pressures cause the upper and lower pressures to move forward, may be different, and if so, one of the pressures will be very strong. As a result, the method has problems that can result in the mold becoming deformed, or, in the worst case, that the adjustment plate breaks.

SUMMARY OF THE INVENTION This invention was created to solve these drawbacks. Its purpose is to provide a method for manufacturing upper and lower molds and their respective apparatus that can prevent the mold from sagging and the adjustment plate to break. To achieve this, the method for manufacturing upper and lower molds of the claim comprises the steps for holding the adjustment plate between the box and drag flasks, inserting upper and lower pressing means into the respective openings of the box and drag flasks. , whose openings are opposite to the adjustment plate, thus defining the upper and lower molding spaces, and then providing molding sand to the upper and lower molding spaces and causing the pressure means | The upper and lower plates move forward to the adjustment plate to press the molding sand to the upper and lower molding spaces, where during the step of causing the upper and lower pressing means to move forward of the plate. Adjust the difference between the pressures of the upper and lower molding spaces is kept within a predetermined tolerance. Further, the apparatus for manufacturing upper and lower molds of claim 2 is an apparatus for holding the adjustment plate between the box and carry flasks, by inserting the upper and lower pressing means into the respective openings of the box flasks. and dragging, where the openings are opposite to the adjustment plate, therefore the upper and lower molding spaces are defined to then provide molding sand to the upper and lower molding spaces, and causing the upper pressure means and lower ones move forward to the adjustment plate to press the molding were in the upper and lower molding spaces. The apparatus comprises the upper and lower means which cause the upper and lower pressing means to move back and forth from the adjustment plate the means for measuring the upper and lower pressure which are installed in the upper and lower means and which they measure the respective pressures when the sand is pressed, and means of transmitting commands that determines the difference between the values measured by the means measuring the upper and lower pressure and compares them with the predetermined tolerance. If the difference is greater than the tolerance, the command transmission means will send a command to the driving means to stop causing the driving means having the highest pressure to move forward, until the difference is within the default tolerance. The inventions comprising the aforementioned components cause the upper and lower pressing means to move forward towards an upper and lower driving means, so that they press the molding sand in the upper and lower molding spaces. During this period, the difference between the upper and lower pressures is determined based on the result of the measurement of its upper and lower measuring means and compared with a predetermined tolerance. If the difference is greater than the predetermined tolerance, a command transmission means will send a command to the driving means to stop the driving means, which has a higher pressure, to move forward until the difference is within the default tolerance. In this invention, each of the upper and lower driving means is a hydraulic cylinder with a hydraulic power source or an electric cylinder with an energy unit. If the driving means without hydraulic cylinders, each of the upper and lower measuring means is a pressure sensor installed in the hydraulic power unit that measures the oil pressure or a load cell that measures the strength of the hydraulic cylinder. If they are electric cylinders with one unit of energy, then each of the measuring means is a voltmeter installed in the power source that measures the voltage, or a load cell that measures the force of the electric cylinder. An ammeter can be used instead of a voltmeter. The apparatus for manufacturing upper and lower molds is that which produces upper and lower molds of tight flasks, or one that manufactures the upper and lower molds without flasks. As is clear from the explanation above, the method of claim 1 comprises the steps for securing an adjustment plate between the box and entrainment flasks, by inserting the upper and lower pressing means into the respective openings of the box flasks. and dragging, whose openings are opposite to the adjustment plate, therefore, the upper and lower molding spaces are defined, to then provide the molding sand to the upper and lower molding spaces and causing the upper pressure means and lower ones move forward toward the adjustment plate to tighten the molding sand in the upper and lower molding spaces, where during the step which causes the upper and lower pressing means to move forward toward the adjustment plate the difference between the pressures of the upper and lower molding spaces remains within the predetermined tolerance. Therefore, because the upper and lower pressing means can be moved forward towards the adjustment plate under the conditions that the upper and lower pressing means are balanced, that is, the difference is kept within the predetermined tolerance , the mold can be prevented from buckling, or the adjustment plate can be prevented from breaking.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a schematic diagram of an apparatus for manufacturing upper and lower molds of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Now, the modality of an apparatus for manufacturing upper and lower molds, referred to in Figure 1, will be analyzed. As presented in Figure 1, this apparatus comprises an adjustment plate 1, box and drag flasks 2 and 3, means of upper and lower pressures 4 and 5, hydraulic cylinders 7 and 8 with a hydraulic power unit 6, upper and lower pressure sensors 9 and 10, and a command transmission means 11. Hydraulic cylinders 7 and 8 have functions for the upper and lower driving means causing the upper and lower pressing means 4 and 5 to move back and forth from the adjustment plate 1. The upper and lower pressure sensors 9 and 10 are installed in the power unit 6 and have functions in the upper and lower pressure measuring means which measure the respective pressures when the sand is pressed. The command transmission means 11 determines the difference between the values measured by the upper and lower pressure sensors 9 and 10 and compares them with the predetermined tolerance. If the difference is greater than the predetermined tolerance, the means 11 will send a command to the hydraulic power unit 6 so that it stops which causes any of the hydraulic cylinders 7 or 8 having the highest pressure to move forward until the difference is within the predetermined tolerance. In addition, the hydraulic power unit 6 has two shift valves 13 and 14. Each valve activates an oil supply to the respective port of the hydraulic cylinders 7 and 8, this oil is supplied from an oil pump 12. The apparatus comprising the aforementioned components hold the adjustment plate 1 between the box and drag flasks 2 and 3. Then, the apparatus inserts the pressure means 4 and 5 into the respective openings of the box and drag flasks 2 and 3, which The openings are opposite to the adjustment plate 1, so that the upper and lower molding spaces are defined in this way. Then, molding sand is provided to the upper and lower molding spaces. Then, this causes the pressure means 4 and 5 to move towards the adjustment plate 1 to press the molding sand and manufacture upper and lower molds. When the molding sand in the upper and lower molding spaces is pressed, the pressure sensors 9 and 10 measure the pressures of the hydraulic cylinders 7 and 8, send the measurement values the command transmission means 11. Then, the command transmission means 11 determines the difference between the pressures of the hydraulic cylinders 7 and 8. If the difference is greater than the predetermined tolerance, the means 11 will send a command to change the valve 13 or 14 of the hydraulic power unit 6 and change the position of the valve to stop, causing any of the cylinders 7 or 8 that have the highest pressure to move forward until the difference is within tolerance. After that, while the molding sand in the upper and lower molding spaces is pressed, the oil pressure in the cylinder 7 or 8 having the lowest pressure is increased.

When the pressure differences in the cylinders 7 and 8 are within the predetermined tolerance, the position of the change valve 13 or 14 will be changed and any of the cylinders 7 or 8 that have the highest pressure will be reset to move forward. By repeating these operations and maintaining the difference of the upper and lower pressures within the predetermined tolerance, the molding sand in the upper and lower molding spaces is pressed and, therefore, the pressure will be complete.

Claims (8)

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as a priority: CLAIMS

1. A method for manufacturing upper and lower molds comprising the steps for holding an adjustment plate between the box and drag flasks, inserting upper and lower pressing means into the respective openings of the box and drag flasks, whose openings are opposite to the adjustment plate, therefore, by defining the upper and lower molding spaces, then supplying molding sand to the upper and lower molding spaces and causing the upper and lower pressing means to move forward towards the plate of adjustment for pressing the molding sand in the upper and lower molding spaces, where during the step causing the upper and lower pressing means to move towards the adjustment plate, the difference between the pressures of the molding spaces higher and lower stays within the predetermined tolerance.

2. An apparatus for manufacturing upper and lower molds is an apparatus for holding an adjustment plate between the box and drag flasks, by inserting the upper and lower pressing means into the respective openings of the box and drag flasks, these openings are opposite to the adjustment plate, which defines the upper and lower molding spaces, to then supply the molding sand in the upper and lower molding spaces and causing the upper and lower pressure means to move towards the adjustment plate for pressing the molding sand into the upper and lower molding spaces, which comprises the upper and lower means causing the respective upper and lower pressing means to move back and forth from the adjustment plate., and means of transmission of commands that determines the difference between the values measured by the upper pressure measurement means and lower and compares them with the predetermined tolerance, and if the difference is greater than the tolerance, the means of transmission of commands will send a command to the driving means so that they stop which causes that the driving means that have the highest pressure move forward until the difference is within the predetermined tolerance.

3. - The apparatus for manufacturing upper and lower molds according to claim 2, characterized in that the upper and lower driving means are hydraulic cylinders with a hydraulic power unit, and the upper and lower pressure measuring means are pressure sensors that They are installed in the hydraulic power unit.

4. - The apparatus for manufacturing upper and lower molds according to claim 3, characterized in that the pressure sensors are load cells that measure the strength of the hydraulic cylinders.

5. The apparatus for manufacturing upper and lower molds according to claim 2, characterized in that the upper and lower conducting means are electric cylinders with power unit and the upper and lower pressure measuring means are voltmeters installed in the unit of energy.

6. The apparatus for manufacturing upper and lower molds according to claim 5, characterized in that the upper and lower pressure measuring means are load cells that measure the force of the electric cylinders.

7. The apparatus for manufacturing upper and lower molds according to claim 2, characterized in that the upper and lower conduction means of the power unit and the upper and lower pressure measuring means are ammeters that are installed in the unit. of energy.

8. - The apparatus for manufacturing upper and lower molds according to claim 7, characterized in that the upper and lower pressure means are load cells that measure the strength of the electric cylinders.