JP5772488B2 - Core sand removal method - Google Patents

Description

  The present invention relates to a core sand removal method, and more particularly, to a core sand removal method for dropping core sand by applying mechanical external force such as hammering or vibration.

  Conventionally, as a core sand dropping method in a cast product, a mechanical external force such as hammering or vibration is applied to drop the core sand in the cast product (see Patent Document 1).

  This is because a metal piece is inserted into the hollow part of the core sand and mechanical external force such as hammering or vibration is applied to cause the metal piece to vibrate in the hollow part of the core sand so as to collapse the core sand. ing.

JP-A-10-286665

  However, in the above conventional example, a metal piece is inserted into the hollow portion of the core sand, and the metal piece is vibrated in the hollow portion of the sand core to collapse the core sand. For this reason, in order to reuse core sand, the operation | work which isolate | separates the metal piece which is a foreign material from core sand after a core collapse | crumbles was required, and there existed a malfunction which an operation process increased. Moreover, the metal piece which is a foreign material may remain in a casting product, and there exists a possibility that product quality may fall.

  Then, this invention is made | formed in view of the said problem, and it aims at providing the core sand removal method suitable for refine | miniaturizing core sand, without mixing a foreign material.

  The present invention includes a striking step of striking a cast product coarse material filled with a sand core and having a sand discharge port with a predetermined impact force, and a predetermined amount of core preset in the cast product rough material after the striking step. And a vibration process for applying vibration to the rough cast product in a state in which the sand remains and is retained.

  Therefore, in the present invention, the friction between the core sands can be ensured in the entire process of the vibration process, and the core sand is refined without leaving a small core lump at the end of the vibration process. be able to.

The schematic block diagram of the core sand removal apparatus which shows one Embodiment of this invention. Process drawing which shows the process of a core sand removal method. The flowchart which shows the control routine of an opening-and-closing lid apparatus. The time chart which shows the change of the residual amount and discharge | emission amount of core sand. Explanatory drawing which shows the state of the sand core contained in the cast product coarse material after casting. Explanatory drawing explaining the state of the core sand crushed by the striking process. Explanatory drawing explaining the state of core sand by a vibration process. The time chart which shows another method of ensuring predetermined amount of core sand in a cast product rough material.

  Hereinafter, the core sand removing method of the present invention will be described based on one embodiment. FIG. 1 is a schematic view of a core sand removing device 1 for carrying out a core sand removing method to which the present invention is applied.

  In FIG. 1, a core sand dropping device 1 clamps and supports a cast product coarse material 2 having a sand core 3 therein, and applies an external force by vibration to the cast product coarse material 2 and a clamp. And a hammer device 5 for applying an external force by striking the cast product rough material 2.

  The hammer device 5 connects an air hammer 51 that applies a striking external force to the cast product rough material 2, a pneumatic source 52 that is connected to the air hammer 51 and supplies pressurized air to the air hammer 51, and a pneumatic source 52 and the air hammer 51 are connected to each other. And an electromagnetic on-off valve 53 disposed in the pipeline. The hammer device 5 operates the air hammer 51 by supplying pressurized air from the air pressure source 52 to the air hammer 51 via the electromagnetic on-off valve 53, and applies impact to the cast product rough material 2 by impact. It is what is letting.

  The vibration device 4 includes a clamp arm 41 that clamps and supports the cast product coarse material 2 from above and below, and a vibration motor (not shown) that applies a vibration force in the arrow direction to the cast product coarse material 2 via the clamp arm 41. And a main body 42 with a built-in. The vibration device 4 is normally used to vibrate the clamp arm 41 by operating a vibration motor and apply an external force due to vibration to the supported cast product coarse material 2. The vibration device 4 includes an opening / closing lid device 6 that is installed on the clamp arm 41 and opens and closes the sand discharge port 21 of the cast product coarse material 2. The opening / closing lid device 6 can close the sand discharge port 21 of the cast product coarse material 2 by advancing the lid member 62 by the actuator 61, and the sand discharge port of the cast product coarse material 2 by retreating the cover member 62. 21 can be opened.

  Generally, in casting of an aluminum alloy or the like, a sand core 3 is used as a method for forming a hollow portion inside a cast product. The sand core 3 is formed by solidifying the core sand with a binder, set in a mold, cast by pouring molten metal into the mold, and after casting, the sand core 3 is cast together with the casting. Taken from. The sand core 3 remaining inside the casting is generally made into core sand by applying mechanical external force such as hammering / vibration to the casting to form core sand. It is discharged to the outside of the casting through the mouth 21).

  FIG. 2 shows a sand removal process by the core sand removal method according to the present embodiment. The sand dropping process includes a work setting process S1, a striking process S2, a vibration process S3, a discharging process S4, and a work resetting process S5. In the work setting step S <b> 1, the rough cast product 2 is clamped and supported from above and below by the clamp arm 41 of the vibration device 4. In the striking step S2, the air hammer 51 of the hammer device 5 is actuated on the clamped cast product rough material 2 to repeatedly exert a striking external force. In the vibration step S3, a vibration external force is applied to the cast product rough material 2 in a state where a predetermined amount of core sand is secured by the blocking operation by the opening / closing lid device 6 from the vibration device 4 for a predetermined time. In the discharging step S <b> 4, the core sand that has become granular due to the opening of the opening / closing lid device 6 is discharged. In the work reset process S5, the cast product coarse material 2 from which the core sand is discharged is unclamped from the vibration device 4 and carried out.

  The remaining amount of core sand remaining in the cast product rough material 2 is estimated by subtracting the amount of core sand discharged from the sand discharge port 21 from the total amount of core sand constituting the sand core 3. can do. The remaining amount of core sand remaining in the cast product coarse material 2 is also estimated by measuring the reaction force against the vibration input by the vibration device 4 and measuring the weight of the cast product coarse material 2 itself. be able to.

  The opening / closing lid device 6 is controlled to be opened / closed by a control routine of the opening / closing lid device 6 that is operated between the end of the striking step S2 shown in FIG. 3 and the vibration step S3, and is closed at the start stage of the discharging step S4 → Open controlled. That is, in the control routine of the opening / closing lid device 6 shown in FIG. 3, the discharged amount of core sand discharged is detected in step S11, and the detected discharge amount of core sand is preset in step S12. It is determined whether or not the amount is between the upper limit amount and the lower limit amount. When the discharge amount of the core sand detected in step 12 has not reached the remaining amount between the preset upper limit amount and lower limit amount, the current processing step is terminated. When the detected discharge amount of the core sand reaches an amount between a preset upper limit amount and lower limit amount, the routine proceeds to step 13 where the open / close lid device 6 is closed and the processing step is ended.

  FIG. 4 is an explanatory diagram showing the steps of sand removal to be performed with time on the horizontal axis for the cast product coarse material 2 clamped and supported by the clamp arm 41 of the vibration device 4 from the upper and lower surfaces. . In FIG. 4, the vertical axis indicates the remaining amount of core sand remaining in the cast product coarse material 2 (upper AG) and the amount of discharged core sand (lower ag). Show.

  As shown in FIG. 5, the cast product coarse material 2 clamped and supported by the clamp arm 41 of the vibration device 4 is present in a state in which the sand core 3 is solidified in the space by the binder. . The amount of core sand in the space of the cast product coarse material 2 is indicated by point A at time t0 in the figure.

  In the striking step S2, the hammer 1 of the hammer device 5 is actuated in a state in which the sand discharge port 21 that does not actuate the opening / closing lid device 6 is opened, and the hammering force 2 is applied to the cast product rough material 2 multiple times. . When a plurality of external impact forces are applied, the sand core 3 provided inside the cast product coarse material 2 can efficiently break the sand core 3 into a relatively large lump as shown in FIG. it can.

  At the time point t1 when the striking step S2 is completed, a part of the sand core 3 becomes a small core sand 31 by being crushed into a relatively large lump, and is discharged from the sand discharge port 21. For this reason, when the amount of core sand discharged from the sand discharge port 21 is relatively large (solid line state in the figure), the discharge amount of the core sand 31 is between the preset upper limit amount and lower limit amount. The amount is reached (b and B points in the figure). In this case, the opening / closing lid device 6 is operated, the sand discharge port 21 is closed, and the discharge of the core sand 31 in the vibration step S3 is blocked. However, when the amount of core sand discharged from the sand discharge port 21 is relatively small (broken line state in the figure), the amount of core sand 31 discharged is an amount between a preset upper limit amount and lower limit amount. In this case, the opening / closing lid device 6 is kept open.

  In this striking step S2, the crushed relatively large lump is in a state where it can move freely in the space. In this way, when the crushed lump can move freely within the casting hollow part, the blow becomes difficult to be transmitted to the core sand 31 and the large lump cannot be made fine, and all the core sand 31 is blown. Therefore, it is difficult to discharge the fine core sand 31.

  In the vibration process S3, the vibration motor of the vibration device 4 is actuated to vibrate the clamp arm 41 and apply an external force due to vibration to the supported cast product rough material 2 over a predetermined time. In this method of applying vibration, the acceleration applied to the cast product coarse material 2 and the sand core 3 is small as compared with the method of applying impact, and the sand core 3 taken out from the mold is almost completely clogged. In FIG. 5, the sand core 3 cannot be crushed. However, in the present embodiment, the core sand 31 in the space of the cast product coarse material 2 is crushed to some extent in the striking step S2, so that the core sand 31 lump, the friction between the core sands 31 and the space between them. Friction with the casting surface that constitutes, and the lump of core sand 31 is gradually reduced.

  In this vibration process S3, when the sand discharge port 21 is opened without operating the opening / closing lid device 6, the core sand 31 is discharged, and the core remaining in the cast product coarse material 2 remains. The remaining amount of sand 31 is small. In this case, there is a problem that the friction between the core sands 31 is lost, and a small lump of core sand 31 remains as indicated by the broken line BG in the figure.

  However, in the present embodiment, as indicated by a solid line BC in FIG. 4, the sand discharge port 21 is closed by the opening / closing lid device 6, so that the remaining amount of the core sand 31 is set to a predetermined predetermined amount. Set to quantity.

  In addition, the vibration process S3 is executed in a state where the remaining amount of the core sand 31 at the start of the vibration process S3 is B ′, the open / close lid device 6 is maintained in the open state, and the sand discharge port 21 is open. Then, the core sand 31 that has become granular is discharged from the sand discharge port 21. Note that, as described above, even when the remaining amount of the core sand 31 at the start of vibration is large at point B ′, if the sand discharge port 21 remains open, the core sand 31 is discharged. Will progress. Then, the remaining amount of the core sand 31 remaining in the cast product rough material 2 becomes small, the friction between the core sands 31 disappears, and the remaining amount in the figure is shown by a broken line B′-E′-G. This causes a problem that a lump of small core sand 31 remains.

  However, in the present embodiment, at the time point t3 (points e and E in the figure) when the discharge amount between the upper limit amount and the lower limit amount set in advance with the passage of time is reached, the sand discharge port is opened by the opening / closing lid device 6. 21 is closed and the discharge is blocked. As a result, as indicated by a broken line B′-E-C, the remaining amount of the core sand 31 is set to a predetermined predetermined remaining amount.

  Further, the opening / closing lid device 6 is maintained in an open state with the remaining amount of the core sand 31 at the start of the vibration step S3 being B ', and the vibration step S3 is started in a state in which the sand discharge port 21 is open. If it does, discharge | emission of the refined core sand 31 may advance rapidly. In such a case, the core sand amount detected to be discharged exceeds the predetermined upper limit and is discharged (point e'E ', time point t2), and the opening / closing lid device 6 is closed at the subsequent time point t2. There is. As described above, when the core sand 31 is excessively discharged, the excessively discharged core sand 31 is returned to the space of the cast product coarse material 2 (point F), and the core sand 31 remains. The amount is a predetermined remaining amount set in advance (B'-E'-FC).

  As described above, in the present embodiment, the remaining amount of the core sand 31 in the space of the cast product coarse material 2 in the vibration process S3 is ensured to be a predetermined predetermined amount. For this reason, the friction between the core sands 31 can be secured in the entire course of the vibration step S3, without causing a problem that a small lump of core sand 31 remains at the end of the vibration step S3, The core sand 31 can be refined. The predetermined remaining amount set in advance is preferably 10% or more because the core sand hardly comes out when it falls below 10% of the initial weight of the core sand 3 after casting in the cast product coarse material 2. If the predetermined remaining amount set in advance is 30% or more, it is more preferable because sufficient friction between core sands can be secured. The appropriate value of the predetermined remaining amount set in advance is different depending on the shape of the work (core part), and is thus obtained in advance by experiments.

  In the discharging step S4 (time t4-t5), the opening / closing lid device 6 is opened, and the core sand 31 in the space of the cast product coarse material 2 is discharged via the sand discharge port 21. The core sand 31 in the space of the cast product coarse material 2 is sufficiently miniaturized because vibration is applied in a state where the remaining amount is ensured to a predetermined remaining amount. For this reason, the core sand 31 can be smoothly discharged from the space of the cast product coarse material 2 without clogging the sand discharge port 21 (point CD in the figure). Even when the core sand 31 is completely discharged (time t5), a small amount of fine core sand may remain in the space of the cast product coarse material 2. Such fine core sand 31 can be discharged from the space of the cast product coarse material 2 to the outside by air blowing.

  In the work reset process, the cast product coarse material 2 from which the core sand 31 is discharged is unclamped from the vibration device 4 and carried out.

  In the above embodiment, as a means for retaining and retaining a predetermined amount of the core sand 31 of the cast product coarse material 2, a means for retaining and retaining a predetermined amount by closing the sand discharge port 21 with the opening / closing lid device 6. explained. However, as shown in FIG. 8, the opening / closing lid device 6 may not be used. That is, in FIG. 8, when the core sand 31 of the cast product coarse material 2 is reduced from a predetermined amount, the discharged core sand 31 is removed from the cast product coarse material 2 every time the core sand 31 is reduced from the predetermined amount. It is designed to return to the child space. In the illustrated solid line example, the return is made only once at the time point t3. However, as shown by the broken line, the return may be made a plurality of times. The core sand 31 to be returned is not limited to that discharged from the sand discharge port 21 of the cast product coarse material 2. For example, a hopper storing the core sand 31 is disposed above the cast product coarse material 2. The core sand 31 may be supplied from the hopper every time it is reduced from a predetermined amount.

  In the present embodiment, the following effects can be achieved.

  (A) A hitting step S2 in which the cast product coarse material 2 filled with the sand core 3 and having the sand discharge port 21 is hit with a predetermined impact force, and after the hitting step S2, the cast product coarse material 2 is preset. And vibrating step S3 that vibrates the cast product coarse material 2 with vibration in a state in which a predetermined amount of core sand 31 remains and is retained. For this reason, the friction between the core sands 31 can be secured in the entire course of the vibration step S3, without causing a problem that a small lump of core sand 31 remains at the end of the vibration step S3, The core sand 31 can be refined and can be smoothly discharged from the inside of the cast product coarse material 2.

  (A) The remaining core core 31 of the cast product coarse material 2 is retained and retained by returning the core sand 31 discharged from the sand discharge port 21 of the cast product coarse material 2 into the cast product coarse material 2 again. Made. That is, by supplying the core sand 31 to the cast product rough material 2 again, the core sand 31 necessary for reducing the lump by friction is replenished, and the core sand 31 remaining as a lump is eliminated and fine. And can be smoothly discharged from the inside of the cast product coarse material 2.

  (C) Remaining and holding the core sand 31 of the cast product coarse material 2 returns the core sand 31 discharged from the sand discharge port 21 of the cast product coarse material 2 to the cast product coarse material 2 and casts it again. This is done by closing the sand discharge port 21 of the coarse product 2. That is, by keeping the core sand 31 discharged from the sand discharge port 21 inside the cast product coarse material 2, the core sand 31 remaining as a lump is eliminated even if the amount of sand supplied is small. And can be smoothly discharged from the inside of the cast product coarse material 2. Moreover, even when the size of the sand discharge port 21 is large and the supplied core sand 31 is immediately discharged, the above-described effects can be exhibited.

  (D) The core sand 31 of the cast product coarse material 2 is retained and retained by closing the sand discharge port 21 at the time of starting the vibration process S3. For this reason, the same effect as described above can be obtained without supplying the core sand 31 discharged from the sand discharge port 21 again.

  (E) Remaining / holding of the core sand 31 of the cast product coarse material 2 is performed when the core sand 31 discharged from the sand discharge port 21 of the cast product coarse material 2 reaches a preset amount. This is done by closing the mouth 21. For this reason, the same effect as described above can be obtained without supplying the core sand 31 discharged from the sand discharge port 21 again.

DESCRIPTION OF SYMBOLS 1 Core sand removal apparatus 2 Cast product coarse material 3 Sand core 4 Excitation apparatus 5 Hammer apparatus 6 Opening and closing cover apparatus 21 Sand discharge port 31 Core sand 41 Clamp arm 42 Main body 51 Air hammer 52 Air pressure source 53 Electromagnetic switching valve 61 Actuator 62 Lid member

Claims (5)

A striking step of striking a cast product coarse material filled with a sand core and having a sand discharge port with a predetermined impact force;
And a vibration step of applying vibration to the cast product coarse material in a state in which a predetermined amount of core sand is retained and retained in the cast product coarse material after the hitting step. The core sand removal method.   The core sand that remains in the cast product coarse material is retained and retained by returning the core sand discharged from the sand discharge port of the cast product coarse material into the cast product coarse material again. Item 1. The core sand removing method according to Item 1.   Remaining and retaining the core sand of the cast product coarse material, the core sand discharged from the cast product coarse material discharge port is returned to the cast product coarse material and the cast product coarse material discharge port is used. The core sand removing method according to claim 1, wherein the core sand removing method is performed by closing.   2. The core sand dropping method according to claim 1, wherein the core sand remaining and retained in the cast product coarse material is made by closing a sand discharge port at the time of starting the vibration process S <b> 3.   The core sand remaining and retained in the cast product coarse material is closed by closing the sand discharge port when the core sand discharged from the cast product coarse material discharge port reaches a preset amount. The core sand removing method according to claim 1.

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