Method and device for separating aluminum chips from aluminium cast sand

Abstract

To surely separate chips from cast sand containing the chips resulting from cutting an unnecessary part from an aluminum cast product.SOLUTION: This method hot-dries cast sand containing aluminum chips resulting from cutting an unnecessary part from a n aluminum cast molding, separates sand of the cast sand and the aluminum chips, and separately recovers them. The hot-drying is performed by forming an air duct 14 that covers a conveyance path and by a dry conveyor 12 having a hot-air blower 16 for supplying hot air disposed in the air duct 14. The sand and the aluminum chips are separated by a separation conveyor 23 provided with a sifting floor 29b for sifting and separating only the sand in the cast sand made of mesh or a punch medal on an upper side and conveying the aluminum chips and a receiving floor 29a for receiving and conveying the sifted sand.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method and device for separating aluminum chips from molding sand for aluminum casting. [Background technology]

[0002] Conventionally, in low-pressure casting methods using cores for complex structures such as intake manifolds for automobile engines, the thickness of the removed parts, which are unnecessary parts other than the molded product, such as the sprue and the molten metal, is thick, and they are cut off with a cutter to be separated from the product.

[0003] For this reason, aluminum chips are mixed in when core sand is recovered. When using it as recycled sand, it is desirable to separate it from the sand in terms of the quality of the sand mold and effective use of the aluminum raw material. However, due to factors such as processing costs, the sand is often recycled with the aluminum chips still included.

[0004] On the other hand, Patent Document 1 is known as an apparatus for separating aluminum ingots that are mixed into the molding sand obtained by disassembling the mold after sand casting of an aluminum product. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Utility Model Application Publication No. 56-169943 Summary of the Invention [Problem to be solved by the invention]

[0006] The inventions disclosed in the above patent documents are directed to preventing damage to the furnace materials of a melting furnace caused by the aluminum ingots containing mineral components of the foundry sand together with the aluminum ingots when used aluminum casting sand is disassembled and recovered, and then aluminum ingots such as aluminum lumps and burrs remaining in the recovered sand are separated, recovered, and reused.

[0007] Furthermore, since the device of the present invention is intended for molding sand containing relatively large lumps of aluminum ingot, separation of the sand and the aluminum lumps is relatively easy.

[0008] However, as mentioned above, in the case of aluminum products with complex shapes produced by the low-pressure casting method using a core, when a large amount of chips is mixed in with the core sand, the cutting oil used when cutting with a cutter often causes clumps of sand and chips to form, or the two become stuck together by the oil, or the sand and chips become clumped together, resulting in a problem that the sand and aluminum chips cannot be sufficiently separated. [Means for solving the problem]

[0009] The method of the present invention for solving the above problems is characterized in that, first, molding sand containing aluminum chips produced by cutting off unnecessary parts of a molded product after casting an aluminum part is dried with hot air, and the sand and aluminum chips of the molding sand are separated and recovered separately.

[0010] Secondly, the hot air drying is performed by the drying conveyor 12 having an air duct 14 that covers the transport path and a hot air blower 16 that supplies hot air into the air duct 14.

[0011] Thirdly, the sand and aluminum chips are separated by a separating conveyor 23 equipped with a sieve bed 29b on the upper side made of mesh or punched metal which sifts and separates only the sand in the casting sand and transports the aluminum chips, and a receiving bed 29a which receives and transports the sieved sand.

[0012] Fourthly, a vibrating conveyor is used as the sorting conveyor 23.

[0013] The equipment of the present invention is characterized in that it comprises, firstly, a hopper 7 into which molding sand containing aluminum chips after casting of aluminum parts is input and which supplies the molding sand to a drying process, a drying conveyor 12 which receives the molding sand discharged from the hopper 7, transports it to the next process, and is arranged in combination with a hot air blower 16 which supplies hot air into an air duct 14 which covers the transport path, and a separating conveyor 23 which receives the molding sand dried on the drying conveyor 12 on the downstream side, transports it to the next process, and separates the sand and aluminum chips in the molding sand and collects them separately.

[0014] Secondly, the foundry sand is used in low-pressure casting using a core, and is characterized by containing cutting chips produced when unnecessary parts other than the product are cut away.

[0015] Thirdly, the separating conveyor 23 is characterized in that it is provided with a sieve bed 29b on the upper side made of mesh or punched metal that sifts and separates only the sand in the foundry sand, and a receiving bed 29a that receives and transports the sand that has passed through.

[0016] Fourthly, the sorting conveyor 23 is a vibrating conveyor.

[0017] Fifthly, a transfer conveyor 21 is provided between the drying conveyor 12 and the separating conveyor 23 to relay the foundry sand sent from the drying conveyor 12 and send it to the separating conveyor 23. Effect of the Invention

[0018] According to the method and apparatus of the present invention configured as described above, chips can be efficiently and easily separated from molding sand for aluminum casting without the need for equipment with particularly new functions, thereby preventing deterioration of the quality of the sand mold due to the inclusion of chips and contributing to the effective use of aluminum materials.

[0019] In particular, the use of cooling and lubricating fluid during cutting with a cutter makes it easy to break up and disperse the sand lumps and separate the sand and chips, and the vibrating conveyor ensures that these can be separated and collected separately. [Brief description of the drawings]

[0020] [Figure 1] FIG. 2 is a front view showing an example of a connection arrangement of each processing machine, illustrating an overview of the device of the present invention. [Diagram 2] FIG. 1 is a flow diagram illustrating the method of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The drawings show one embodiment of the present invention. The apparatus shown in FIG. 1 is equipped with a hopper device 1 which collects used foundry sand after demolding and feeds it by a conveyor or the like (not shown).

[0022] The hopper device 1 is provided with a hopper 7 having an opening 2 in the shape of a box frame, for example, with each side being 1,300 mm square, at the top, a convergence case 3 having an inverted trapezoidal cross section on the bottom, and an axle case 6 at the bottom of the convergence case 3, which supports a spiral shaft 4 in the left-right direction.

[0023] A motor 8 for driving the spiral shaft 4, for example at 200 mm and 30 rpm, is provided at the left protruding end of the shaft case 6, and a discharge port 9 for discharging downward the casting sand delivered by the spiral shaft 4 from inside the hopper 7 is provided at the right protruding end. The hopper 7 is attached to and supported on a machine frame 11.

[0024] On the downstream side (right side) of the hopper device 1 and below the discharge outlet 9, there is disposed the starting end of a drying conveyor 12, which is a belt conveyor using, for example, a hinge-type steel belt for transporting chips, die-cast parts, etc., and which receives the foundry sand discharged from the discharge outlet 9 and transports it to the next process downstream. A guide frame 13 is attached to the upper outer periphery of the conveyor to prevent the supplied foundry sand from spilling out.

[0025] Furthermore, the transport path of the conveyor is covered with a tunnel-shaped air duct 14 that runs along the longitudinal direction, and a hot air blower 16 is disposed at its downstream opening end, with an exhaust port 17 of the hot air blower 16 opening toward the downstream opening end of the air duct 14. Hot air is sent into the air duct 14 in the opposite direction to the transport direction of the casting sand by the conveyor, and the casting sand is dried by the hot air as it is transported.

[0026] In the illustrated example, the machine frame 18 of the drying conveyor 12 and the machine frame 19 of the hot air blower 16 are separate, but not only the two, but also the entire separating device may be an integrated frame that can be assembled and disassembled. 2 It is possible to supply hot air from room temperature to about 350°C at an air volume of about 1 / min.

[0027] Below the end of the drying conveyor 12, there is installed a transfer conveyor 21 consisting of an inclined conveyor with a Z-shaped frame which receives the transported foundry sand while it is being dried at its start end and carries it up to a high position at the rear (downstream side). This conveyor generally uses a hinge-type steel belt conveyor capable of transporting chips, scrap, die-cast products, etc. A guide frame 22 is provided on the outer periphery of the upper surface (conveyance path side) of the transfer conveyor 21 to prevent cargo from spilling. In this conveyor, the dried foundry sand which has been heated and made easier to crush is crushed to a certain extent and separated from the sand and chips while being transported to the next process.

[0028] Furthermore, a separating conveyor 23 consisting of a vibrating conveyor is arranged below the upper end downstream of the transfer conveyor 21, which receives the foundry sand mixed with chips from the end of the transfer conveyor 21 at its starting end (upstream end) and separates and recovers the chips and sand at the end while performing final separation.

[0029] The sorting conveyor 23 has a box-shaped enclosed sorting body 27 attached to a body frame 24 via coil springs and other elastic members 26, and a back-and-forth reciprocating vibrator 28 attached to the bottom side of the sorting body 27.

[0030] The separator 27 is further provided with a lower receiving bed 29a constituting a bottom plate, and a flat sieve bed 29b made of mesh or punched metal or the like, which is arranged in parallel on the receiving bed 29a. Both bed materials simultaneously move back and forth (left and right in the drawing) by, for example, about 1 to 2 cm, to transport the transported material (casting sand) downstream at a speed of about 20 m / min.

[0031] When the foundry sand is transferred from the transfer conveyor 21 to the sorting conveyor 23, it is first received by the upper sieve bed 29b and transported downstream. The return vibration of the sieve bed 29b separates the sand from the chips mixed in the foundry sand. The aluminum chips consisting of crescent-shaped cutting pieces are left on the sieve bed 29b and transported downstream, but the fine sand is sieved and falls onto the receiving bed 29a, and is sent downstream by the vibration of the receiving bed 29a.

[0032] At the end of the receiving bed 29a and the sieve bed 29b, outlets 31a and 31b are installed facing downwards to collect and discharge the sand and chips transported separately from the surfaces of both beds. Below the outlets 31a and 31b, there are provided recovery sections 32a and 32b consisting of a transport path to the next process or a recovery container for separately collecting the sand and chips discharged from the outlets 31a and 31b.

[0033] As described above, according to the present invention, foundry sand after demolding, including chips resulting from cutting of castings after casting in a low-pressure aluminum casting method or the like, can be charged into the hopper 7, dried with hot air by the drying conveyor 12, and then crushed, and the sand and chips can be separated and recovered while being vibrated and transported by the separating conveyor 23.

[0034] In the above-mentioned device, the transfer conveyor 21 is interposed between the drying conveyor 12 and the sorting conveyor 23. However, it is also possible to use an inclined conveyor (not shown) with a higher end (downstream end) as the drying conveyor 12 to directly supply hot-air dried foundry sand to the sorting conveyor 23, or to install the sorting conveyor 23 at a lower position than the drying conveyor 12 shown in the figure, thereby directly supplying foundry sand from the drying conveyor 12 to the sorting conveyor 23. [Explanation of symbols]

[0035] 7. Hopper 12 Drying conveyor 14 Air Duct 16 Hot air blower 21 Transfer Conveyor 23 Sorting conveyor 29a Receiving bed 29b Sieve bed

Claims

1. A method for separating aluminum chips from foundry sand for aluminum casting, in which foundry sand containing aluminum chips resulting from the cutting of unnecessary parts of a molded product after casting of an aluminum part is dried with hot air, and the sand and aluminum chips of the foundry sand are separated and separately recovered.

2. 2. The method for separating aluminum chips from molding sand for aluminum casting according to claim 1, wherein the hot air drying is performed by a drying conveyor (12) having an air duct (14) covering the conveying path and a hot air blower (16) for supplying hot air into the air duct (14).

3. 2. The method for separating aluminum chips from foundry sand for aluminum casting according to claim 1, wherein the separation of the sand and the aluminum chips is carried out by a separation conveyor (23) provided with a sieve bed (29b) on the upper side made of mesh or punched metal for sieving and separating only the sand in the foundry sand and transporting the aluminum chips, and a receiving bed (29a) for receiving and transporting the sieved sand.

4. 4. The method for separating aluminum chips from molding sand for aluminum casting according to claim 3, wherein a vibrating conveyor is used as the separating conveyor (23).

5. This aluminum chip separation device for molding sand for aluminum casting comprises: a hopper (7) into which molding sand containing aluminum chips after casting of aluminum parts is input and which supplies the molding sand to a drying process; a drying conveyor (12) which receives the molding sand discharged from the hopper (7), transports it to the next process, and is arranged in combination with a hot air blower (16) which supplies hot air into an air duct (14) covering the transport path; and a separating conveyor (23) which receives the molding sand dried on the drying conveyor (12) downstream, transports it to the next process, and separates the sand and aluminum chips in the molding sand and collects them separately.

6. 6. The aluminum chip separating device for aluminum casting molding sand according to claim 5, wherein the molding sand is used molding sand produced by a low-pressure casting method using a core, and contains chips produced when unnecessary parts other than the product are cut off.

7. 6. The aluminum chip separating device for aluminum casting molding sand as claimed in claim 5, wherein the separating conveyor (23) is provided with a sieve bed (29b) made of mesh or punched metal on the upper side for sieving and separating only the sand in the molding sand, and a receiving bed (29a) for receiving and transporting the sand that has passed through.

8. 8. The apparatus for separating aluminum chips from molding sand for aluminum casting according to claim 5, wherein the separating conveyor (23) is a vibrating conveyor.

9. 8. The aluminum chip separating device for aluminum casting molding sand according to claim 5, further comprising a transfer conveyor (21) interposed between the drying conveyor (12) and the separating conveyor (23) for relaying the molding sand sent from the drying conveyor (12) and sending it to the separating conveyor (23).

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