JP2012148328A - Casting method, and heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for removing a subject adhered to a casting die without using powder.SOLUTION: The casting method for manufacturing a cast product, chemically reactive to an alkaline solvent, includes: an application step (S16) of applying the alkaline solvent to at least a part of a cavity forming surface of a casting mold; a recovery step (S18) of recovering gas generated in the application step; and a heating step (S32) of heating at least a part of a casting apparatus by using heat generated by burning the gas recovered in the recovery step.

Description

  The present specification discloses a casting method and a heating apparatus.

  In the casting process, the molten metal is poured into the cavity of the casting mold, and the molten metal is solidified to produce a cast product. When the molten metal solidifies, it is baked on the casting mold, and after the cast product is taken out from the casting mold, a part of the casting material may remain attached to the casting mold. When the casting process is performed with the casting material attached to the casting mold, the quality of the cast product is degraded.

  Patent Document 1 discloses a technique for removing an object attached to a casting mold. In the technique of Patent Document 1, an object attached to the casting mold is removed by injecting titanium powder into the casting mold.

JP-A-9-295320

  In the technique of Patent Document 1, it is necessary to inject powder at a high speed in order to remove an object attached to a casting mold. For this reason, there exists a possibility that powder may fly around a casting mold. Therefore, it is desirable to remove the object attached to the casting mold by a method other than spraying the powder.

  On the other hand, when the casting apparatus before the casting process is at a low temperature, the molten metal does not flow smoothly through the casting apparatus, so that the quality of the cast product is deteriorated. For this reason, it is necessary to heat casting apparatuses, such as a casting mold and a sleeve, before pouring a molten metal. The present specification provides a technique for skillfully solving both of removing an object attached to a casting mold without injecting powder into the casting mold and heating the casting apparatus.

  The inventors of the present invention have noted that one type of casting product uses a casting material that causes a chemical reaction with an alkaline solvent. Casting materials that cause a chemical reaction with an alkaline solvent are, for example, aluminum alloys and magnesium alloys. In such a casting material, the casting material adhering to the casting mold can be removed by using an alkaline solvent. On the other hand, the substance generated by the chemical reaction between the casting material and the alkaline solvent has potential energy, and the potential energy can be extracted as combustion heat. Based on such knowledge, the inventors have created a technique for heating a casting apparatus using the result of removing an object attached to a casting mold, as described below.

  The technology disclosed in this specification is a casting method for producing a cast product of a casting material that chemically reacts with an alkaline solvent. This casting method includes a coating process, a recovery process, and a heating process. In the applying step, an alkaline solvent is applied to at least a part of the cavity forming surface of the casting mold. In the recovery step, a gas containing a component generated by causing a chemical reaction between the alkaline solvent and the casting material on the cavity forming surface is recovered. In the heating step, at least a part of the casting apparatus is heated using heat generated by burning the gas recovered in the recovery step.

  In the above casting method, the casting material adhering to the casting mold is removed by causing a chemical reaction between the casting material adhering to the casting mold and the alkaline solvent. According to this structure, the casting material adhering to the casting mold can be removed without spraying the powder onto the casting mold. In the above casting method, the casting apparatus is heated using the combustion heat of the gas generated by the chemical reaction between the casting material and the solvent. According to this configuration, the gas generated by removing the casting material adhering to the casting mold can be used effectively. In the heating step, it is preferable to heat at least one of the sleeve and the casting mold in the casting apparatus.

  The above casting method may further include a specific step of specifying the amount of gas recovered by the recovery step. The amount of cast material adhering to the casting mold can be estimated from the amount of gas recovered, and the casting state can be further estimated from the result.

  Said casting method may further comprise the specific process which specifies the component contained in the gas collect | recovered by a collection process. The state of casting can also be estimated from the gas component. For example, foreign matters other than the casting material may adhere to the casting mold, and gas may be generated by a chemical reaction between the foreign matter and the solvent. By specifying the substance contained in the gas recovered by the recovery process, it is possible to determine whether or not foreign matter is attached to the casting mold. Note that the component is typically identified by using a gas sensor that reacts to each of a plurality of components that are assumed to be contained in the gas. Instead of the gas sensor, an odor sensor may be adopted to specify (including estimation) a component from the gaseous odor.

  A heating apparatus for realizing the above casting method is also novel and useful. This heating apparatus includes a recovery unit and a heating unit. The recovery unit recovers a gas containing a substance generated by causing a chemical reaction between the alkaline solvent and the casting material on the cavity forming surface by applying an alkaline solvent to the cavity forming surface of the casting mold. The heating unit heats at least a part of the casting apparatus by using heat generated by burning the collected gas.

  According to the technique disclosed in this specification, the casting material attached to the casting mold can be removed, and the casting apparatus can be heated using the gas generated by the removal. That is, the technique disclosed in this specification obtains a part of energy (fuel) necessary for heating the casting apparatus from the process of removing the casting material. For this reason, the fuel which should be supplied from the outside in order to heat a casting apparatus can be reduced.

The casting mold and heating apparatus of an Example are shown. The flowchart which shows a casting method is shown. The casting mold and heating apparatus of a modification are shown.

  The casting apparatus 10 is an apparatus for producing an aluminum alloy casting product. As shown in FIG. 1, the casting apparatus 10 includes a movable mold 12, a fixed mold 14, and a sleeve 18. The movable mold 12 is pressed and separated from the fixed mold 14. When the movable mold 12 is crimped to the fixed mold 14, a cavity is formed by the cavity forming surface 12 a of the movable mold 12 and the cavity forming surface 14 a of the fixed mold 14. A sleeve 18 for injecting molten aluminum alloy into the cavity is attached to the fixed mold 14.

  The heating device 50 includes a cover 52, a passage tube 54, a gas measurement unit 56, a heating unit 58, and a coating device 70. The coating device 70 is operated by an operator. The coating device 70 applies an alkaline solvent (for example, sodium hydroxide aqueous solution) to the cavity forming surfaces 12a and 14a in a state where the movable mold 12 and the fixed mold 14 are separated from each other. The coating device 70 may be configured separately from the heating device 50. Moreover, the small piece which the code | symbol X of FIG. 1 shows typically represents the molten metal (aluminum alloy) which adhered and solidified to the type | mold at the time of casting.

  The cover 52 has a hollow partial spherical shape, and the lower end and the upper end are open. The cover 52 is disposed above the gap between the movable mold 12 and the fixed mold 14 when the solvent is applied by the coating device 70.

  One end of a passage tube 54 is connected to the opening at the upper end of the cover 52. The passage tube 54 has a cylindrical shape, and a heating unit 58 is connected to the other end of the passage tube 54. The heating unit 58 stores the gas flowing in from the passage pipe 54 and burns the stored gas.

  A gas measuring unit 56 is attached at an intermediate position of the passage tube 54. The gas measurement unit 56 includes a gas sensor 56a, a flow meter 56b, and a control unit 56c. The gas sensor 56 a specifies a component contained in the gas that passes through the passage pipe 54. The flow meter 56b measures the flow rate (ie, volume) of the gas flowing through the passage tube 54. The gas sensor 56a and the flow meter 56b are each connected to the control unit 56c. The control unit 56c stores a database 56d. In the database 56d, the correspondence between the mass of the aluminum alloy consumed for the reaction in the reaction between the aluminum alloy of the same type as the aluminum alloy used for casting and the alkaline solvent and the composition and volume of the gas generated by the reaction is recorded. ing.

  The operator stores the database 56d in the control unit 56c before using the heating device 50 in the actual casting device 10. Specifically, the worker applies an alkaline solvent to an aluminum alloy having a known mass. An operator measures the volume of gas (that is, hydrogen) generated until the aluminum alloy and the solvent undergo a chemical reaction and all of the aluminum alloy is dissolved. The operator performs the same experiment on a plurality of aluminum alloys having different masses, and measures the volume of the generated gas. The operator records the experiment result in the database 56d. As a result, the correspondence between the mass of the aluminum alloy consumed for the reaction and the component and volume of the gas generated by the reaction is recorded in the database 56d.

  Next, the casting method will be described. A flowchart of the casting method is shown in FIG. 2 is premised on starting after the cast product is taken out of the mold in the previous casting step (S34 and S36 in FIG. 2). That is, the process of the flowchart of FIG. 2 starts from a state where the movable mold 12 and the fixed mold 14 are open. In addition, the following process may be implemented whenever it casts a cast product, and may be implemented after casting a some cast product continuously.

  In S16, the coating device 70 applies an alkaline solvent to the cavity forming surfaces 12a and 14a. More specifically, the operator arranges the cover 52 above the gap between the movable mold 12 and the fixed mold 14, and then operates the coating device 70 to thereby apply an alkaline solvent to the cavity forming surfaces 12a and 14a. Apply.

  When a solvent is applied to the aluminum alloy X (see FIG. 1) attached to the cavity forming surface 14a, the aluminum alloy X and the solvent cause a chemical reaction to generate hydrogen. This hydrogen contains an aluminum component (ie, aluminum vapor). Since the generated hydrogen is lighter than the atmosphere, it flows upward. The generated hydrogen is collected by the cover 52 and collected in the passage pipe 54 (S18). The hydrogen recovered in the passage pipe 54 passes through the gas sensor 56 a and the flow meter 56 b disposed in the passage pipe 54 and is stored in the heating unit 58.

  When the application of the solvent by the coating device 70 is started, the gas sensor 56a analyzes (specifies) the component contained in the gas (S20). The gas sensor 56a supplies the component identification result to the control unit 56c. The gas sensor 56a executes a process of specifying a component at a predetermined time interval until a stop instruction is acquired from the control unit 56c.

  In S22, the control unit 56c displays the specific result acquired from the gas sensor 56a, that is, the component of the gas that has passed through the passage tube 54. In S24, when it is determined that the recovered gas contains aluminum as a result of component identification, the control unit 56c determines the flow rate of gas per unit time measured by the flow meter 56b (that is, the amount of gas passing through the passage pipe 54) Start volume). The control unit 56c integrates the gas flow rate measured by the flow meter 56b until the specific result of the gas sensor 56a does not contain aluminum. The controller 56c notifies the operator when the gas flow rate measured by the flow meter 56b decreases. For example, the control unit 56c may notify the worker by sounding a buzzer. When notified from the control unit 56c, the operator operates the coating device 70 to finish the application of the solvent to the cavity forming surfaces 12a and 14a.

  When the specific result acquired from the gas sensor 56a does not contain aluminum, the control unit 56c supplies a stop instruction to the gas sensor 56a. As a result, the gas sensor 56a stops specifying the gas component. In S26, the control unit 56c specifies the integration result of the flow rate measured by the flow meter 56b as the volume of hydrogen generated by causing a chemical reaction between the aluminum alloy and the solvent.

  Next, in S28, the control unit 56c estimates the mass of the aluminum alloy adhering to the cavity forming surfaces 12a and 14a. Specifically, the control unit 56c refers to the database 56d and identifies the mass of the aluminum alloy corresponding to the hydrogen volume identified in S26. The controller 56c determines the mass of the identified aluminum alloy as the estimated mass of the aluminum alloy that has adhered to the cavity forming surfaces 12a and 14a. When the hydrogen volume specified in S26 is not recorded in the database 56d, the control unit 56c executes the following process. That is, the control unit 56c specifies the mass of the aluminum alloy that is associated with the hydrogen volume that is close to the hydrogen volume specified in S26 among the hydrogen volumes recorded in the database 56d. Next, the control unit 56c estimates the mass of the aluminum alloy using the identified mass. In S30, the control unit 56c displays the estimated mass of the aluminum alloy.

  According to this configuration, the operator can check the estimated value of the mass of the aluminum alloy displayed on the flow meter 56b, that is, the mass of the aluminum alloy attached to the cavity forming surfaces 12a and 14a. The operator can appropriately determine whether or not the release agent should be applied by confirming the adhesion amount of the aluminum alloy. For example, if the adhesion amount of the aluminum alloy is larger than usual, the operator can determine that the release agent should be applied. In addition, when surface treatment for preventing seizure is performed on the cavity forming surfaces 12a and 14a, the worker has deteriorated the surface treatment if the adhesion amount of the aluminum alloy is larger than usual. It can be judged.

  In addition, the solvent applied to the cavity forming surfaces 12a and 14a and flowing to the lower side of the casting apparatus 10 is recovered and reused. For this reason, there is a possibility that the alkali component contained in the solvent is reduced and no chemical reaction occurs with the aluminum alloy. When the adhesion amount of the aluminum alloy estimated in S28 is smaller than usual, it can be determined that the worker and the solvent are deteriorated and no chemical reaction occurs with the aluminum alloy.

  Next, in S <b> 32, the heating unit 58 burns the stored hydrogen to heat the sleeve 18. In another embodiment, the heating unit 58 may heat the movable mold 12 and the fixed mold 14. Alternatively, the heating unit 58 may heat a container for pouring the molten metal into the sleeve 18.

  After a part of the casting apparatus such as the sleeve 18 is heated, the movable mold 12 and the fixed mold 14 are pressure-bonded. Thereafter, an aluminum alloy is injected from the sleeve 18 into the cavity (S34). Next, after a predetermined time has elapsed, the movable mold 12 is separated from the fixed mold 14 and the cast product is taken out from the cavity (S36). Thus, a cast product is manufactured.

  In the above casting method, an alkaline solvent is applied to the cavity forming surfaces 12a and 14a to react the aluminum alloy attached to the cavity forming surfaces 12a and 14a with the solvent, thereby removing the aluminum alloy. According to this configuration, the aluminum alloy can be removed without spraying powder onto the aluminum alloy attached to the cavity forming surfaces 12a and 14a. For this reason, there is no worry that the injected powder hits the human body. Moreover, according to this structure, compared with the structure which sprays and removes a powder to an aluminum alloy, an aluminum alloy can be removed neatly.

  Moreover, in said casting method, the casting apparatus 10 is heated by burning the hydrogen which generate | occur | produced by reaction of an aluminum alloy and a solvent. According to this structure, the fuel which should be supplied in order to heat the casting apparatus 10 can be reduced.

  If foreign matter such as dust adheres to the cavity forming surfaces 12a and 14a, the foreign matter and the solvent may cause a chemical reaction to generate gas. In this case, in the gas sensor 56a, components other than aluminum are specified. The operator can confirm whether or not a foreign substance is attached to the cavity forming surfaces 12a and 14a by confirming the gas component displayed on the control unit 56c.

The modifications of the above embodiment are listed below.
(1) About the heating apparatus 150 (FIG. 3) of a modification, a different point from the heating apparatus 50 of an Example is demonstrated. As shown in FIG. 3, the heating device 150 according to the modified example includes a portion of the cavity forming surfaces 12a and 14a to which the solvent is applied by a coating device (not shown) (a portion to which the aluminum alloy X is attached in FIG. 3). ) Is provided above the cover 152. Further, the heating device 150 includes a heating unit 158 disposed in the sleeve 18 from the cavity forming surface 14a side. The cover 152 and the heating unit 158 are connected by a passage tube 154. Although not shown, the heating device 150 may include a gas measurement unit similar to the heating device 50.

(2) The above casting method is used to remove the aluminum alloy X adhering to a casting mold for producing an aluminum alloy casting product. However, the target casting material is not limited to an aluminum alloy. The above casting method can also be used for a casting mold for producing a casting product of another material (for example, magnesium alloy) that causes a chemical reaction with an alkaline solvent.

(3) The heating devices 50 and 150 heat the sleeve 18 or the movable mold 12 and the fixed mold 14. That is, the heating devices 50 and 150 heat at least a part of the casting device 10. The heating devices 50 and 150 may heat the casting device 10 from which the aluminum alloy is removed, that is, a casting device other than the casting device 10 to which an alkaline solvent is applied.

(4) The heating devices 50 and 150 may include a suction unit that sucks the gas into the passage tubes 54 and 154 via the covers 52 and 152.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

DESCRIPTION OF SYMBOLS 10: Casting apparatus 12: Movable type | mold 12a, 14a: Cavity formation surface 14: Fixed type | mold 18: Sleeve 50: Heating device 52: Cover 54: Passage pipe 56: Gas measuring part 56a: Gas sensor 56b: Flowmeter 56c: Control part 58 : Heating unit

Claims (5)

A casting method for producing a casting product of a casting material that chemically reacts with an alkaline solvent,
An application step of applying an alkaline solvent to at least a part of the cavity forming surface of the casting mold;
A recovery step of recovering a gas containing components generated by a chemical reaction between the alkaline solvent and the casting material on the cavity forming surface;
And a heating step of heating at least a part of the casting apparatus using heat generated by burning the gas recovered in the recovery step.   The casting method according to claim 1, further comprising a specific step of specifying a recovery amount of the gas recovered by the recovery step.   The casting method according to claim 1, further comprising a specific step of specifying a component contained in the gas recovered by the recovery step.   The casting method according to any one of claims 1 to 3, wherein the heating step heats at least one of the sleeve and the casting mold in the casting apparatus. A recovery unit that recovers a gas containing a substance generated by causing a chemical reaction between the alkaline solvent and the casting material on the cavity forming surface by applying an alkaline solvent to the cavity forming surface of the casting mold,
A heating apparatus comprising: a heating unit that heats at least a part of the casting apparatus using heat generated by burning the collected gas.

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