WO2021220586A1 - Sand mold shaping device - Google Patents

Abstract

This sand mold shaping device (10) comprises: a blow head (48) that retains wet sand; and a blow plate unit (56) that is provided between the blow head and a forming mold (20). The blow plate unit comprises: a sand introduction path (86) through which passes the wet sand blown into the forming mold from the blow head by compressed air supplied by the blow head; and at least one compressed air introduction path (P1, P2) that blows compressed air towards the wet sand blown into the forming mold through the sand introduction path. An acute angle is formed between a blow-in direction (X) for the wet sand into the forming mold from the blow head via the sand introduction path, and a blow-in direction (Y1, Y2) for the compressed air blown towards the wet sand via the at least one compressed air introduction path .

Description

Sand molding equipment

The present invention relates to a sand molding device, and more specifically, to a sand molding device for molding a sand mold by blowing wet sand into a molding mold.

A molding device for molding a sand mold is disclosed in, for example, Patent Document 1. The molding apparatus disclosed in Patent Document 1 blows wet sand from a blow head into a molding die (core mold main body) via a blow plate to form a sand mold. In this molding device, a blow nozzle and an air sleeve for air ejection are provided in the core sand introduction passage of the blow plate through which the blown sand passes, and the air is blown out horizontally through the blow nozzle and the air sleeve. The compressed air stirs the wet sand flowing in the core sand introduction passage.

Jikkenhei No. 3-31047

However, wet sand has high viscosity and poor filling property, so it may block a narrow flow path or the like. Therefore, in the molding apparatus of Patent Document 1, when molding a sand mold having a complicated shape, it may not be possible to fill every corner of the cavity of the molding mold with wet sand.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a sand molding apparatus capable of suitably filling a molding mold with wet sand when the wet sand is blown into a molding mold to mold a sand mold. To do.

The specification of the present application discloses the sand molding apparatus described in the following items.

[Item 1]
It is a sand molding device that molds sand molds by blowing wet sand into the molding molds.
A blow head that holds the wet sand and
A blow plate unit provided between the blow head and the molding die,
With
The blow plate unit is
A sand introduction passage through which the wet sand blown from the blow head into the molding die by compressed air supplied to the blow head, and a sand introduction passage through which the wet sand passes.
At least one compressed air introduction passage that blows compressed air toward the wet sand that is blown into the mold through the sand introduction passage.
Have,
The direction of blowing the wet sand from the blow head through the sand introduction passage to the mold and the direction of blowing compressed air from the blow head toward the wet sand through the at least one compressed air introduction passage. A sand molding device whose angle is set to an acute angle.

In the sand molding apparatus according to the embodiment of the present invention, the wet sand blown from the blow head toward the molding mold is opened in the sand introduction passage and the molding mold by the compressed air blown from the compressed air introduction passage of the blow plate unit. It is agitated in the vicinity of the part and blown into the molding mold while being finely dispersed. The angle between the blowing direction of wet sand from the blow head to the molding die through the sand introduction passage and the blowing direction of compressed air toward the wet sand through the compressed air introduction passage is set to a sharp angle. As a result, the compressed air from the compressed air introduction passage functions to push the wet sand into the molding mold from behind, so that the filling property of the wet sand into the cavity of the molding mold is improved. Therefore, since the molding die can be suitably filled with wet sand, even a sand mold having a complicated shape can be suitably molded.

[Item 2]
The sand introduction passage includes an inlet portion located on the blow head side and an outlet portion located on the molding mold side.
The sand molding apparatus according to item 1, wherein the opening area of the outlet portion is larger than the opening area of the entrance portion.

If the opening area of the outlet of the sand introduction passage is larger than the opening area of the entrance, the flow velocity of the wet sand passing through the sand introduction passage becomes slower at the outlet than at the entrance. Therefore, the wet sand collides with each other in the sand introduction passage and is further agitated, and is further dispersed at the outlet portion wider than the inlet portion. As a result, the straightness of the wet sand is lowered, and the lump of the wet sand can be prevented from sticking (sticking) to the mold, so that a molded product (sand mold) having good mold releasability can be obtained.

[Item 3]
It is a sand molding device that molds sand molds by blowing wet sand into the molding molds.
A blow head that holds the wet sand and
A blow plate unit provided between the blow head and the molding die,
With
The blow plate unit is
A sand introduction passage through which the wet sand blown from the blow head into the molding die by compressed air supplied to the blow head, and a sand introduction passage through which the wet sand passes.
At least one compressed air introduction passage that blows compressed air toward the wet sand that is blown into the mold through the sand introduction passage.
Have,
The sand introduction passage includes an inlet portion located on the blow head side and an outlet portion located on the molding mold side.
A sand molding device in which the opening area of the outlet portion is larger than the opening area of the entrance portion.

In the sand molding apparatus according to the embodiment of the present invention, the wet sand blown from the blow head toward the molding mold is opened in the sand introduction passage and the molding mold by the compressed air blown from the compressed air introduction passage of the blow plate unit. It is agitated in the vicinity of the part and blown into the molding mold while being finely dispersed. Since the opening area of the outlet portion of the sand introduction passage is larger than the opening area of the inlet portion, the flow velocity of the wet sand passing through the sand introduction passage becomes slower at the outlet portion than at the inlet portion. Therefore, the wet sand collides with each other in the sand introduction passage and is further agitated, and is further dispersed at the outlet portion wider than the inlet portion. As a result, the straightness of the wet sand is lowered, and the lump of the wet sand can be prevented from sticking (sticking) to the mold, so that a molded product (sand mold) having good mold releasability can be obtained.

[Item 4]
The sand molding apparatus according to item 2 or 3, wherein the opening area of the outlet portion is larger than the sum of the opening area of the inlet portion and the diameter area of the outlet of the at least one compressed air introduction passage.

If the opening area of the outlet of the sand introduction passage is larger than the sum of the opening area of the inlet and the diameter of the outlet of the compressed air introduction passage, the difference between the opening area of the inlet and the opening area of the outlet is further increased. Since it can be made larger, the wet sand passing through the sand introduction passage can be further agitated and dispersed. Therefore, it is possible to further prevent the lump of wet sand from sticking to the molding die.

[Item 5]
The sand molding apparatus according to any one of items 2 to 4, wherein the wet sand contains an inorganic binder.

Inorganic binders are generally binding. Therefore, when the wet sand contains an inorganic binder, if the wet sand adheres to the mold, it becomes difficult for the sand mold to be released from the mold, and if the mold is forcibly released, the sand mold may be broken. Since the opening area of the outlet portion is larger than the opening area of the inlet portion, even when the wet sand contains an inorganic binder, the wet sand can be sufficiently agitated and dispersed, so that the wet sand can be dispersed. It is possible to preferably prevent the lumps from sticking to the molding die.

[Item 6]
The at least one compressed air introduction passage is a plurality of compressed air introduction passages.
The sand molding apparatus according to any one of items 1 to 5, wherein the plurality of compressed air introduction passages are formed so that compressed air blown from the plurality of compressed air introduction passages collide with each other.

By blowing compressed air from a plurality of compressed air introduction passages so as to collide with each other, it is possible to further promote agitation and dispersion of wet sand. Therefore, the molding die can be more preferably filled with wet sand.

[Item 7]
The blow plate unit is
A blow plate provided between the blow head and the molding die,
Hollow cylindrical bush and
Have,
The blow plate has a communication hole for communicating the blow head and the molding die.
The sand molding apparatus according to any one of items 1 to 6, wherein the bush is provided in the communication hole of the blow plate and has the sand introduction passage.

When the blow plate unit adopts a configuration having a blow plate provided between the blow head and the molding die and a hollow cylindrical bush, the desired molding can be performed simply by replacing the bush provided in the communication hole of the blow plate. It can easily correspond to the conditions and the type of molded product (sand mold) to be obtained.

[Item 8]
The sand molding apparatus according to item 7, wherein the at least one compressed air introduction passage is formed from the blow plate to the bush.

When a compressed air introduction passage is formed from the blow plate to the bush (that is, includes a "first part" formed on the blow plate and a "second part" formed on the bush), the bush is replaced. Only by itself, conditions such as the blowing direction of compressed air to the sand introduction passage can be easily changed.

[Item 9]
The sand molding apparatus according to item 8, wherein the blow plate unit further includes a vent plug arranged in a portion of the at least one compressed air introduction passage formed in the bush.

By arranging the vent plug in the part (second part) formed in the bush of the compressed air introduction passage, the pneumatic equipment can be protected from the wet sand invading the compressed air introduction passage.

[Item 10]
The at least one compressed air introduction passage is a plurality of compressed air introduction passages.
The sand molding apparatus according to item 8 or 9, wherein the bush is a groove formed in an annular shape on the outer periphery and has a groove forming a part of the plurality of compressed air introduction passages.

When there are a plurality of compressed air introduction passages, if the bush is a groove portion formed in an annular shape on the outer periphery and has a groove portion forming a part of the plurality of compressed air introduction passages, one first portion. Compressed air can be supplied to the plurality of second portions through the groove portion. Therefore, it is not necessary to separately form the first portion on the blow plate with respect to the plurality of second portions formed on the bush. Therefore, when a plurality of sand introduction passages are provided in the blow plate unit, a plurality of bushes can be arranged in close proximity to each other.

According to the embodiment of the present invention, there is provided a sand mold molding apparatus capable of suitably filling the mold with wet sand when the wet sand is blown into the mold to mold the sand mold.

It is a figure which shows typically the sand molding apparatus 10 by embodiment of this invention, and is the cross-sectional view seen from the front direction. It is a figure which shows typically the sand molding apparatus 10, and is the cross-sectional view seen from the side. It is sectional drawing which shows typically the main part of the blow head 48, the blow plate unit 56, and the molding die 20. It is a top view which shows the bush 60 schematically. It is sectional drawing which shows typically the bush 60. It is a figure which shows typically the behavior of wet sand. It is sectional drawing which shows typically the main part of the sand molding apparatus 10a by another embodiment of this invention. It is sectional drawing which shows typically the main part of the sand molding apparatus 10b according to still another embodiment of this invention. It is sectional drawing which shows typically the main part of the sand molding apparatus 10c according to still another embodiment of this invention. It is sectional drawing which shows typically the main part of the sand molding apparatus 10d by still another Embodiment of this invention. It is sectional drawing which shows typically the main part of the sand molding apparatus 10e according to still another embodiment of this invention. It is sectional drawing which shows typically the main part of the sand molding apparatus 10f according to still another embodiment of this invention. FIG. 5 is a cross-sectional view taken along the line FF'in FIG. 8A. It is sectional drawing which shows typically the main part of the sand molding apparatus 10g by still another Embodiment of this invention. 9 is a cross-sectional view taken along the line GG'in FIG. 9A. It is sectional drawing which shows typically the bush 60g of the sand molding apparatus 10g. It is sectional drawing which shows the example which arranged a plurality of bushes 60g in close proximity to blow plate unit 58g.

Hereinafter, the sand molding apparatus according to the embodiment of the present invention will be described with reference to the drawings.

1A and 1B show the sand molding apparatus 10 according to the embodiment of the present invention. 1A and 1B are views schematically showing the sand molding apparatus 10, and are a cross-sectional view seen from the front direction and a cross-sectional view seen from the side, respectively.

The sand molding device 10 is a device for molding a sand mold by blowing wet sand into the molding mold 20. As shown in FIGS. 1A and 1B, the sand molding apparatus 10 includes a blow head 48 for holding wet sand and a blow plate unit 56 provided between the blow head 48 and the molding mold 20.

The sand molding device 10 includes an upper frame 12 supported by a pair of columns (not shown). The upper frame 12 extends in the left-right direction. A through hole 14 penetrating in the vertical direction is formed in the vicinity of the right end portion of the upper frame 12. The through hole 14 is provided at a position corresponding to the filling position.

The blow head 48 is held by a dolly (not shown) suspended from the upper frame 12. The dolly reciprocates along the upper frame 12 between the filling position and the replenishment position on the left side of the filling position. At the replenishment position, wet sand is supplied from the mixer to the blow head 48 via a hopper (both not shown). The wet sand contains a water-soluble inorganic binder, for example, kneaded sand containing a binder containing sodium silicate as a main component.

At the filling position, a pair of columns 16a and 16b are erected at intervals in the front-rear direction. Columns 16a and 16b are, for example, prismatic. The vicinity of the upper part of the columns 16a and 16b is connected by a rotating shaft 18. A mold holding portion 22 for holding the molding mold 20 is attached to the rotating shaft 18.

Cavities 24a and 24b are formed in the upper part and the lower part of the molding die 20, respectively. An opening 26a connected to one cavity 24a is formed on the upper surface of the molding die 20, and an opening 26b connected to the other cavity 24b is formed on the lower surface of the molding die 20.

At the filling position, a hollow cylindrical sleeve 28 is inserted into the through hole 14 of the upper frame 12. A ring-shaped member 30 is attached to the lower end of the sleeve 28. A seal member 32 is provided on the lower surface of the ring-shaped member 30. The sleeve 28 is formed so that the inner diameter increases downward.

A crimping cylinder 34 is attached to the upper end of the sleeve 28. The crimping cylinder 34 includes a cylinder body 36, an intake pipe 38, two exhaust pipes 40a and 40b, two silencers 42a and 42b, and the like. The intake pipe 38 is connected to the surge tank 44, and air is supplied to the surge tank 44 through the pipe 46. In the surge tank 44, the pressure of air is adjusted, and compressed air for sand filling is supplied from the surge tank 44 to the crimping cylinder 34.

The crimping cylinder 34 causes the sleeve 28, the blow head 48, and the blow plate unit 56 to be brought into close contact with the molding die 20 or separated from the molding die 20 by moving a rod (not shown) extending from the cylinder body 36 in the vertical direction. Or something. That is, at the time of sand filling, the rod extending from the cylinder body 36 descends and pushes down the sleeve 28, the blow head 48 and the blow plate unit 56 to bring them into close contact with the molding die 20. After that, when the blow valve (not shown) is opened, the compressed air in the surge tank 44 flows as blow air to the blow head 48 through the intake pipe 38, the cylinder body 36, and the rod. After filling with sand, the blow valve is closed and the residual pressure in the crimping cylinder 34 is released to the atmosphere through the exhaust pipes 40a and 40b and the silencers 42a and 42b. After that, the rod of the crimping cylinder 34 rises, and the sleeve 28, the blow head 48, and the blow plate unit 56 are separated from the molding die 20.

The blow head 48 is formed in a hollow shape, and includes a head middle portion 50, a head upper portion 52, and a head lower portion 54. The middle part 50 of the head and the upper part 52 of the head are connected to each other in the direction of blowing wet sand into the molding die 20 (indicated by an arrow X in FIG. 3B described later), and the middle part 50 of the head and the lower part 54 of the head are also connected in the same direction. Connected to each other.

The central part 50 of the head is formed in a hollow cylindrical shape. Further, the central portion 50 of the head is formed so that the inner diameter thereof is substantially constant. The head upper portion 52 is formed in a hollow cylindrical shape. Further, the head upper portion 52 is formed so that the inner diameter increases from the upper side to the lower side. At the boundary between the head upper portion 52 and the head middle portion 50, the inner surfaces of both are continuously connected. The lower portion 54 of the head is formed in a hollow cylindrical shape. At the boundary between the lower portion 54 of the head and the middle portion 50 of the head, the inner surfaces of both are continuously connected. The lower part 54 of the head is formed so as to expand downward in the front view as shown in FIG. 1A and narrow downward in the side view as shown in FIG. 1B. A cooling path through which the cooling liquid flows may be formed in each of the central portion 50 of the head, the upper portion 52 of the head, and the lower portion 54 of the head. As the coolant, for example, water, oil, ethylene glycol or the like is used.

A blow plate unit 56 is provided so as to cover the lower surface of the blow head 48. At the filling position, the blow plate unit 56 is located between the blow head 48 and the mold 20.

The configuration of the blow plate unit 56 will be described more specifically with reference to FIG. FIG. 2 is a cross-sectional view schematically showing a main part of a blow head 48, a blow plate unit 56, and a molding die 20.

As shown in FIG. 2, the blow plate unit 56 includes a square plate-shaped blow plate 58 and a hollow cylindrical bush 60. The blow plate 58 is provided on the lower surface of the blow head 48, and is located between the blow head 48 and the mold 20 at the filling position. The blow plate 58 has a communication hole 62 in the center thereof for communicating the blow head 48 and the mold 20. The communication hole 62 is formed in a substantially columnar shape, and has a large diameter portion 62a at the upper end portion thereof. The shape and inner diameter of the communication hole 62 are substantially the same as the outer diameter and outer diameter of the bush 60. Therefore, when the bush 60 is fitted into the communication hole 62, the upper surface of the blow plate 58 and the upper surface of the bush 60 are flush with each other, and the lower surface of the blow plate 58 and the lower surface of the bush 60 are flush with each other.

Further, the blow plate 58 has first passage portions 64a and 64b and second passage portions 66a and 66b through which compressed air passes. The first passage portions 64a and 64b and the second passage portions 66a and 66b are formed inside the blow plate 58 slightly upward in the vertical direction.

The first passage portions 64a and 64b are formed so as to extend from one side surface (left side surface in this example) of the blow plate 58 to the right inside the blow plate 58. The first passage portions 64a and 64b are formed substantially parallel to each other with the communication hole 62 interposed therebetween. The second passage portion 66a extends from the vicinity of the right end portion of the first passage portion 64a at right angles to the first passage portion 64a and rearward, and communicates the first passage portion 64a with the communication hole 62. The second passage portion 66b extends from the vicinity of the right end portion of the first passage portion 64b at right angles to the first passage portion 64b and forward, and communicates the first passage portion 64b with the communication hole 62. Therefore, in a plan view, the first passage portion 64a and the second passage portion 66a form a substantially L-shaped passage, and the first passage portion 64b and the second passage portion 66b form a substantially L-shaped passage. Is formed, and the second passage portions 66a and 66b are provided on the same straight line. As shown in FIG. 1A, an intake pipe 68 is connected to one end (left end) of the first passage portions 64a and 64b, respectively. The two intake pipes 68 are connected to one intake pipe 72 via a joint 70. The intake pipe 72 is connected to a pressure adjusting unit 74 having a valve, and air is supplied to the pressure adjusting unit 74 through the pipe 76. In the pressure adjusting unit 74, the pressure of air is adjusted, and compressed air is supplied from the pressure adjusting unit 74 into the blow plate 58.

Further, a cooling passage 78 through which the cooling liquid flows is formed inside the blow plate 58. The cooling passage 78 is substantially U-shaped in a plan view. An annular groove 80 is formed on the lower surface of the blow plate 58 so as to surround the communication hole 62. A seal member 82 is fitted in the groove 80.

The specific configuration of the bush 60 will be described with reference to FIGS. 3A and 3B. FIG. 3A is a top view schematically showing the bush 60, and FIG. 3B is a cross-sectional view schematically showing the bush 60.

The bush 60 has a flange portion 84 provided at the upper end portion thereof and a sand introduction passage 86 penetrating in the vertical direction. The sand introduction passage 86 has an inlet portion 88 located on the blow head 48 side, an outlet portion 90 located on the molding mold 20 side, and a diameter-expanded portion 92 whose inner diameter increases downward from the inlet portion 88. It includes a portion 93 having the same diameter and which is formed downward from the portion 92 and has the same inner diameter. Further, the bush 60 has third passage portions 94a and 94b for communicating the second passage portions 66a and 66b of the blow plate 58 with the sand introduction passage 86. The third passage portions 94a and 94b are formed so that the compressed air blown from the third passage portions 94a and 94b into the sand introduction passage 86 collide with each other. Speaking from the side, as shown in FIG. 3B, the third passage portions 94a and 94b extend obliquely downward toward the sand introduction passage 86. In plan view, as shown in FIG. 3A, the third passage portions 94a and 94b are provided on substantially the same straight line.

As shown in FIG. 2, the compressed air introduction passage P1 is formed by the first passage portion 64a, the second passage portion 66a, and the third passage portion 94a, and similarly, the first passage portion 64b, the second passage portion 66b, and the second passage portion 66b. The compressed air introduction passage P2 is formed by the three passage portions 94b. In other words, the compressed air introduction passages P1 and P2 are formed from the blow plate 58 to the bush 60. In this way, the blow plate unit 56 is formed through the sand introduction passage 86 through which the wet sand blown from the blow head 48 into the molding mold 20 by the compressed air supplied to the blow head 48 passes and the sand introduction passage 86 through the sand introduction passage 86. It has compressed air introduction passages P1 and P2 for blowing compressed air toward the wet sand blown into the 20. The compressed air introduction passages P1 and P2 are formed so that the compressed air blown from the compressed air introduction passages P1 and P2 collide with each other.

As shown in FIG. 3B, the wet sand is blown into the mold 20 from the blow head 48 through the sand introduction passage 86, and the wet sand passes through the third passage portion 94a (compressed air introduction passage P1). The angle D1 formed with the blowing direction Y1 of the compressed air toward the direction is set to an acute angle (that is, D1 is more than 0 ° and less than 90 °). Similarly, the angle D2 formed by the blowing direction X and the blowing direction Y2 of the compressed air toward the wet sand through the third passage portion 94b (compressed air introduction passage P2) is an acute angle (that is, D2 is more than 0 ° and 90 °). Less than). In the illustrated example, the blowing direction X is downward (directly downward), and the angles D1 and D2 are set to about 30 °, respectively.

In the bush 60, the opening area Ao of the outlet portion 90 is larger than the opening area Ai of the inlet portion 88. Further, the opening area Ao of the outlet portion 90 is the opening area Ai of the inlet portion 88 and the diameter areas Aa and Ab of the outlets 95a and 95b of the third passage portions 94a and 94b (compressed air introduction passages P1 and P2), respectively. Greater than the sum of. However, the opening area Ao of the outlet portion 90 is preferably less than three times the total of the above.

In the bush 60, the diameter A of the inlet portion 88 is, for example, 5 mm or more. The angle B of the enlarged diameter portion 92 is 0 ° or more and less than 180 °. The diameter C of the third passage portions 94a and 94b is, for example, 1 mm or more. The diameter E of the outlet portion 90 is larger than the diameter A of the inlet portion 88. In the sand introduction passage 86 of the bush 60, the corners are preferably smooth.

The bush 60 is formed of, for example, a metal material or a fluororesin such as PTFE. When the bush 60 is made of fluororesin, the sticking of wet sand to the bush 60 can be suppressed.

Next, the operation of the sand molding device 10 will be described.

As shown in FIGS. 1A and 1B, at the filling position, the blow head 48 and the blow plate unit 56 are located between the sleeve 28 and the mold 20. The sleeve 28 is pushed down by the rod of the crimping cylinder 34, the lower surface of the sleeve 28 is connected to the upper head 52 of the blow head 48 via the ring-shaped member 30 and the seal member 32, and further, the sleeve 28 and the blow head 48 are connected. And the blow plate unit 56 is pushed down and comes into close contact with the molding die 20. After that, when the blow valve is opened, the compressed air in the surge tank 44 is blown into the blow head 48 via the compression cylinder 34 as blow air. As a result, the wet sand in the blow head 48 is supplied to the cavity 24a of the mold 20 through the sand introduction passage 86 of the blow plate unit 56. At this time, compressed air is blown from the compressed air introduction passages P1 and P2 of the blow plate unit 56 toward the wet sand blown into the mold 20 through the sand introduction passage 86.

Here, the behavior of wet sand will be described with reference to FIG. In FIG. 4, the white arrows indicate how the wet sand mass gradually becomes finer.

First, the wet sand extruded from the blow head 48 into the sand introduction passage 86 of the bush 60 by the compressed air is dispersed into small lumps while diffusing because the flow path is expanded by the enlarged diameter portion 92 of the bush 60.

Almost at the same time that the wet sand is blown from the blow head 48 into the sand introduction passage 86 of the bush 60, the arrows Y1 and the arrow Y1 and the compressed air introduction passages P1 and P2 in the blow plate unit 56 enter the sand introduction passage 86 of the bush 60. Compressed air is blown in the direction indicated by Y2. As a result, the wet sand is agitated and becomes finer lumps and sand grains to be filled in the molding die 20.

After filling with sand, the blow valve is closed, and the residual pressure in the crimping cylinder 34 is released to the atmosphere through the exhaust pipes 40a and 40b and the silencers 42a and 42b. After that, the rod of the crimping cylinder 34 rises, the sleeve 28, the blow head 48, and the blow plate unit 56 are separated from the molding die 20, and further, the head upper portion 52 of the blow head 48 and a member (sleeve 28, etc.) above it. The connection with is disconnected. After that, the blow head 48 and the blow plate unit 56 are temporarily retracted from the filling position by the dolly, and the rotating shaft 18 is rotated to invert the molding die 20. Then, the cavity 24a is located on the lower side, while the cavity 24b is located on the upper side.

Then, again, the blow head 48 and the blow plate unit 56 are moved to the filling position by the dolly. At the filling position, the operation is the same as described above, and the sand filling operation for the cavity 24b of the molding die 20 is performed. After that, the blow head 48 and the blow plate unit 56 are retracted from the filling position by the trolley, and the sand mold, which is a molded product, is removed from the cavities 24a and 24b of the molding mold 20 at the filling position.

The above operation is repeated a desired number of times.

In the sand molding apparatus 10 according to the embodiment of the present invention, the wet sand blown from the blow head 48 toward the molding mold 20 is introduced by the compressed air blown from the compressed air introduction passages P1 and P2 of the blow plate unit 56. It is agitated in the passage 86 and in the vicinity of the opening 26a (26b) of the molding die 20 and blown into the molding die 20 while being finely dispersed. The blowing direction X of the wet sand from the blow head 48 to the mold 20 through the sand introduction passage 86, and the blowing directions Y1 and Y2 of the compressed air toward the wet sand through the compressed air introduction passages P1 and P2. Since the angles D1 and D2 to be formed are set to sharp angles, the compressed air from the compressed air introduction passages P1 and P2 acts to push the wet sand into the molding die 20 from the rear, so that the cavity 24a of the molding die 20 is formed. The filling property of wet sand with respect to (24b) is improved. Therefore, since the molding die 20 can be suitably filled with wet sand, even a sand mold having a complicated shape can be suitably molded. In the sand molding apparatus 10 according to the embodiment of the present invention, the pressure of the compressed air blown from the compressed air introduction passages P1 and P2 and the pressure of the compressed air supplied to the blow head 48 are relatively low (for example, about 0.3 MPa). Even if there is, the mold 20 can be suitably filled with wet sand.

Further, in the sand molding apparatus 10 according to the embodiment of the present invention, the opening area Ao of the outlet portion 90 of the sand introduction passage 86 is larger than the opening area Ai of the inlet portion 88 (that is, the flow path expands), so that sand is formed. The flow velocity of the wet sand passing through the introduction passage 86 is slower at the outlet portion 90 than at the inlet portion 86. Therefore, the wet sand collides with each other in the sand introduction passage 86 and is further agitated, and is further dispersed at the outlet portion 90 wider than the inlet portion 88. As a result, the straightness of the wet sand is lowered, and the lump of the wet sand can be prevented from sticking (sticking) to the molding mold 20, so that a molded product (sand mold) having good mold releasability can be obtained.

When the opening area Ao of the outlet 90 of the sand introduction passage 86 is larger than the sum of the opening area Ai of the inlet 88 and the diameter areas Aa and Ab of the outlets 95a and 95b of the compressed air introduction passages P1 and P2, respectively. Since the difference between the opening area Ai of the inlet portion 88 and the opening area Ao of the outlet portion 90 can be further increased, the wet sand passing through the sand introduction passage 86 can be further stirred and dispersed. Therefore, it is possible to further prevent the lump of wet sand from sticking to the molding die 20.

Inorganic binders are generally binding. Therefore, when the wet sand contains an inorganic binder, if the wet sand adheres to the mold 20, it becomes difficult for the sand mold to be released from the mold 20, and if the mold is forcibly released, the sand mold may be broken. be. Since the opening area Ao of the outlet portion 90 is larger than the opening area Ai of the inlet portion 88, the wet sand can be sufficiently agitated and dispersed even when the wet sand contains an inorganic binder. , It is possible to preferably prevent the lump of wet sand from sticking to the mold 20.

As illustrated, when the blow plate unit 56 has a plurality of compressed air introduction passages P1 and P2, the compressed air is blown from the plurality of compressed air introduction passages P1 and P2 so as to collide with each other, thereby causing wet sand. Stirring and dispersion can be further promoted. Therefore, the molding die 20 can be more preferably filled with wet sand.

When the blow plate unit 56 adopts a configuration having a blow plate 58 provided between the blow head 48 and the molding die 20 and a hollow cylindrical bush 60, the bush 60 provided in the communication hole of the blow plate 58 is provided. By simply replacing it, it is possible to easily correspond to the desired molding conditions, the type of molded body (sand mold) to be obtained, and the like.

Further, when the compressed air introduction passages P1 and P2 are formed from the blow plate 58 to the bush 60, that is, the "first portion" formed in the blow plate 58 (specifically, the first passage portions 64a and 64b). And the second passage portion 66a, 66b) and the "second portion" (specifically, the third passage portion 94a, 94b) formed in the bush 60 are included, and sand is introduced only by replacing the bush 60. Conditions such as the blowing direction of compressed air with respect to the passage 86 can be easily changed.

FIG. 5A shows a sand molding apparatus 10a according to another embodiment of the present invention. The sand molding device 10a shown in FIG. 5A is, so to speak, a “short bush type”, and includes a blow plate unit 56a instead of the blow plate unit 56 of the sand molding device 10 shown in FIG. 2 and the like.

The blow plate unit 56a includes a square plate-shaped blow plate 58a and a hollow cylindrical bush 96. The blow plate 58a has a communication hole 98 in the center thereof that allows the blow head 48 and the mold 20 to communicate with each other. The communication hole 98 is formed in a substantially columnar shape, and has a large diameter portion 98a at the upper end thereof. The shape and inner diameter of the large diameter portion 98a of the communication hole 98 are substantially the same as the outer diameter and outer diameter of the bush 96, and the bush 96 is fitted into the large diameter portion 98a.

Further, the blow plate 58a includes the compressed air introduction passages P3 and P4. The compressed air introduction passage P3 is formed by a first passage portion 64a similar to the blow plate 58 and a second passage portion 100a. The compressed air introduction passage P4 is formed by a first passage portion 64b similar to the blow plate 58 and a second passage portion 100b.

The second passage portion 100a extends from the vicinity of the right end portion of the first passage portion 64a at a right angle to the first passage portion 64a and diagonally backward and downward, and communicates the first passage portion 64a with the communication hole 98. The second passage portion 100b extends from the vicinity of the right end portion of the first passage portion 64b at a right angle to the first passage portion 64b and diagonally forward and downward, and communicates the first passage portion 64b with the communication hole 98. Therefore, in terms of side view, the second passage portions 100a and 100b extend obliquely downward toward the communication hole 98. In a plan view, the first passage portion 64a and the second passage portion 100a form a substantially L-shaped compressed air introduction passage P3, and the first passage portion 64b and the second passage portion 100b form a substantially L-shape. The compressed air introduction passage P4 is formed, and the second passage portions 100a and 100b are provided on substantially the same straight line. The second passage portions 100a and 100b are formed so that the compressed air blown from the second passage portions 100a and 100b into the communication hole 98 (sand introduction passage) collides with each other. In other words, the compressed air introduction passages P3 and P4 are formed so that the compressed air blown from the compressed air introduction passages P3 and P4 collide with each other.

Further, inside the blow plate 58a, a substantially U-shaped cooling passage 102 through which the cooling liquid flows is formed. Further, similarly to the blow plate 58, an annular groove 80 is formed on the lower surface of the blow plate 58a so as to surround the communication hole 98, and the seal member 82 is fitted in the groove 80.

The bush 96 is formed shorter than the bush 60 of the sand molding device 10. The bush 96 has a flange portion 104 provided at the upper end portion thereof and a through hole 106 penetrating in the vertical direction. The through hole 106 has an inlet portion 108 located on the blow head 48 side and a diameter-expanded portion 110 extending downward from the inlet portion 108. The bush 96 is fitted into the large diameter portion 98a of the communication hole 98 so that the upper surface of the bush 96 and the upper surface of the blow plate 58a are flush with each other. The communication hole 98 and the through hole 106 in the state where the bush 96 is fitted into the large diameter portion 98a form a sand introduction passage corresponding to the sand introduction passage 86 of the sand molding apparatus 10.

Since the other configurations of the sand molding device 10a are the same as those of the sand molding device 10, the overlapping description thereof will be omitted. The same effect as that of the sand molding device 10 can be obtained in the sand molding device 10a.

FIG. 5B shows a sand molding apparatus 10b according to still another embodiment of the present invention. The sand molding device 10b shown in FIG. 5B is, so to speak, a “bushless type”, and includes a blow plate unit 56b instead of the blow plate unit 56a of the sand molding device 10a shown in FIG. 5A.

The blow plate unit 56b is different from the blow plate unit 56a in that it does not have a bush. That is, in the blow plate unit 56b, a portion of the blow plate unit 56a corresponding to the bush 96 is integrally formed as a part of the blow plate unit 56b. Therefore, the sand introduction passage 86b of the sand molding apparatus 10b is formed by the communication holes of the blow plate unit 56b. Since the other configurations of the blow plate unit 56b are the same as those of the blow plate unit 56a, the overlapping description thereof will be omitted. The same effect as that of the sand molding device 10a can be obtained in the sand molding device 10b.

FIG. 6A shows a sand molding apparatus 10c according to still another embodiment of the present invention. The sand molding device 10c shown in FIG. 6A is, so to speak, an “opening direct injection type”, and includes a blow plate unit 56c instead of the blow plate unit 56 of the sand molding device 10 shown in FIG. 2 and the like. Further, in the present embodiment, a molding die 20c different from the molding die 20 shown in FIG. 2 or the like is used.

The blow plate unit 56c is formed in a square plate shape thinner than the blow plate unit 56. The blow plate unit 56c has a sand introduction passage 86c in the center thereof. The sand introduction passage 86c is formed by a communication hole that communicates the blow head 48 and the mold 20c. The sand introduction passage 86c has an inlet portion 112 on the blow head 48 side and a diameter-expanded portion 114 extending downward from the inlet portion 112. The depth (vertical dimension) of the opening 116 of the molding die 20c is set to be larger than that of the opening 26a of the molding die 20.

In the sand molding apparatus 10c, compressed air introduction passages P5 and P6 are formed from the blow plate unit 56c to the molding mold 20c. The compressed air introduction passage P5 is formed by a first passage portion 118a and a second passage portion 120a formed in the blow plate unit 56c, and a third passage portion 122a formed in the molding mold 20c. Similarly, the compressed air introduction passage P6 is formed by the first passage portion 118b and the second passage portion 120b formed in the blow plate unit 56c, and the third passage portion 122b formed in the molding mold 20c.

The first passage portions 118a and 118b are formed so as to extend from one side surface of the blow plate unit 56c (the left side surface in this embodiment) to the right inside the blow plate unit 56c. The first passage portions 118a and 118b are formed parallel to each other with the sand introduction passage 86c interposed therebetween. The second passage portion 120a extends from the vicinity of the right end portion of the first passage portion 118a at a right angle to the first passage portion 118a and diagonally backward and downward, and is exposed on the lower surface of the blow plate unit 56c. The second passage portion 120b extends from the vicinity of the right end portion of the first passage portion 118b at a right angle to the first passage portion 118b and diagonally forward and downward, and is exposed on the lower surface of the blow plate unit 56c.

In a state where the blow plate unit 56c is crimped to the molding die 20c, the third passage of the molding die 20c communicates with the second passage portion 120a and the opening 116 and is located on the extension line of the second passage portion 120a. The portion 122a is formed. Similarly, in a state where the blow plate unit 56c is crimped to the molding die 20c, the molding die 20c communicates with the second passage portion 120b and the opening 116 and is located on the extension line of the second passage portion 120b. A third passage portion 122b is formed.

Therefore, as shown in FIG. 6A, in a state where the blow plate unit 56c is crimped to the molding die 20c, the second passage portions 120a and 120b and the third passage portions 122a and 122b have openings in the side view. It extends diagonally downward toward 116. In a plan view, a substantially L-shaped compressed air introduction passage P5 is formed by the first passage portion 118a, the second passage portion 120a, and the third passage portion 122a, and the first passage portion 118b, the second passage portion 120b, and the third passage portion 120b are formed. A substantially L-shaped compressed air introduction passage P6 is formed by the third passage portion 122b, and the second passage portions 120a and 122a and the third passage portions 120b and 122b are provided on substantially the same straight line. The third passage portions 122a and 122b are formed so that the compressed air blown from the third passage portions 122a and 122b into the opening 116 collide with each other. In other words, the compressed air introduction passages P5 and P6 are formed so that the compressed air blown from the compressed air introduction passages P5 and P6 collide with each other. Similar to that shown in FIG. 1A, an intake pipe 68 is connected to one end (left end) of the passages 118a and 118b, respectively.

Further, a substantially U-shaped cooling passage 124 through which the cooling liquid flows is formed inside the blow plate unit 56c. Further, an annular groove 126 is formed on the lower surface of the blow plate unit 56c so as to surround the sand introduction passage 86c, and the seal member 128 is fitted in the groove 126. An annular groove 130 is formed on the upper surface of the molding die 20c at a position corresponding to the groove 126. Therefore, in a state where the blow plate unit 56c is crimped to the molding die 20c, the sealing member 128 fits into the groove 126 and the groove 130 and seals between the blow plate unit 56c and the molding die 20c.

Since the other configurations of the sand molding device 10c are the same as those of the sand molding device 10, the overlapping description thereof will be omitted. The same effect as that of the sand molding device 10 can be obtained in the sand molding device 10c.

FIG. 6B shows a sand molding apparatus 10d according to still another embodiment of the present invention. The sand molding apparatus 10d shown in FIG. 6B is, so to speak, a “crimp surface direct injection type”, and includes a blow plate unit 56d instead of the blow plate unit 56c of the sand molding apparatus 10c shown in FIG. 6A. Further, in the present embodiment, a molding mold 20d different from the molding mold 20c shown in FIG. 6A is used.

The blow plate unit 56d has a second passage portion 132a and 132b different from the second passage portions 120a and 120b of the blow plate unit 56c. Further, the molding mold 20d has third passage portions 134a and 134b different from the third passage portions 122a and 122b of the molding mold 20c. Therefore, the sand molding device 10d has compressed air introduction passages P7 and P8 different from the compressed air introduction passages P5 and P6 of the sand molding device 10c.

The compressed air introduction passage P7 is formed by the first passage portion 118a, the second passage portion 132a, and the third passage portion 134a, and the compressed air introduction passage P8 is formed by the first passage portion 118a, the second passage portion 132b, and the third passage. It is formed by the part 134b. The second passage portion 132a extends from the vicinity of the right end portion of the first passage portion 118a at right angles to the first passage portion 118a and downward, and is exposed on the lower surface of the blow plate unit 56d. The second passage portion 132b extends from the vicinity of the right end portion of the first passage portion 118b at right angles to the first passage portion 118b and downward, and is exposed on the lower surface of the blow plate unit 56d.

In a state where the blow plate unit 56d is crimped to the molding die 20d, the third passage portion 134a is formed on the upper surface of the molding die 20d so as to communicate the second passage portion 132a and the opening 116a. Similarly, in a state where the blow plate unit 56d is crimped to the molding die 20d, the third passage portion 134b is formed on the upper surface of the molding die 20d so as to communicate the second passage portion 132b and the opening 116b.

Therefore, as shown in FIG. 6B, in a state where the blow plate unit 56d is crimped to the molding die 20d, the third passage portions 134a and 134b extend diagonally downward toward the opening 116 in terms of side view. That is, the third passage portions 134a and 134b extend diagonally downward toward the opening 116. In a plan view, a substantially L-shaped compressed air introduction passage P7 is formed by the first passage portion 118a, the second passage portion 132a, and the third passage portion 134a, and the first passage portion 118b, the second passage portion 132b, and the third passage portion 132b are formed. A substantially L-shaped compressed air introduction passage P8 is formed by the third passage portion 134b, and the third passage portions 134a and 134b are provided on substantially the same straight line. The third passage portions 134a and 134b are formed so that the compressed air blown from the third passage portions 134a and 134b into the opening 116 collide with each other. In other words, the compressed air introduction passages P7 and P8 are formed so that the compressed air blown from the compressed air introduction passages P7 and P8 collide with each other.

Since the other configurations of the sand molding device 10d are the same as those of the sand molding device 10c, the overlapping description thereof will be omitted. The same effect as that of the sand molding device 10c can be obtained in the sand molding device 10d.

FIG. 7 shows a sand molding apparatus 10e according to still another embodiment of the present invention. In this embodiment, a molding die 20e different from the molding die 20 shown in FIG. 2 or the like is used.

The molding die 20e has an opening 136 different from the opening 26a of the molding die 20. The opening area of the opening 136 is smaller than the opening area of the opening 26a. The opening area of the opening 136 may be about one-fourth of the opening area Ao of the outlet 90 of the bush 60.

Since the other configurations of the sand molding device 10e are the same as those of the sand molding device 10, the overlapping description thereof will be omitted. The same effect as that of the sand molding device 10 can be obtained in the sand molding device 10e.

Although the case where the blow plate unit has two compressed air introduction passages is illustrated, the number of compressed air introduction passages is not limited to two. The blow plate unit may be provided with only one compressed air introduction passage, or may be provided with three or more compressed air introduction passages. However, the number of compressed air introduction passages is preferably 2 or more.

8A and 8B show a sand molding apparatus 10f according to still another embodiment of the present invention. FIG. 8A is a cross-sectional view schematically showing a main part of the sand molding apparatus 10f, and FIG. 8B is a cross-sectional view taken along the line FF'in FIG. 8A. The sand molding apparatus 10f shown in FIGS. 8A and 8B includes a blow plate unit 56f instead of the blow plate unit 56 of the sand molding apparatus 10 shown in FIG. 2 and the like.

The blow plate unit 56f includes a square plate-shaped blow plate 58f and a hollow cylindrical bush 60f. The blow plate 58f has a groove portion 138 and a passage portion 140 in place of the first passage portions 64a and 64b and the second passage portions 66a and 66b of the blow plate 58. The bush 60f differs from the bush 60 in that it has four passages 94a, 94b, 94c and 94d.

The groove portion 138 is formed in an annular shape in the communication hole 62 of the blow plate 58f at a position corresponding to the outer opening of the passage portion 94a to 94d of the bush 60f. The passage portion 140 is formed in a straight line so as to communicate the groove portion 138 and the front surface of the blow plate 58f. Similar to the sand molding device 10 shown in FIG. 2, an intake pipe 68 as shown in FIG. 1A is connected to one end of the passage portion 140. The intake pipe 68 is connected to one intake pipe 72 via a joint 70. The four passage portions 94a to 94d of the bush 60f are provided at substantially equal intervals. The passage portions 94a to 94d are formed so that the compressed air blown from the passage portions 94a to 94d into the sand introduction passage 86 collide with each other. The bush 60f is arranged so that none of the passage portions 94a to 94d is located on the extension line of the passage portion 140 of the blow plate 58f. In the sand molding device 10f, the compressed air introduction passage is formed by the passage portions 94a to 94d of the bush 60 and the passage portions 140 and the groove portions 138 of the blow plate 58f.

Since the other configurations of the sand molding device 10f are the same as those of the sand molding device 10, the overlapping description thereof will be omitted.

In the sand molding device 10f, compressed air is supplied into the blow plate 58f via the intake pipe 68. The compressed air goes around the outer circumference of the bush 60f through the passage portion 140, passes through the groove portion 138, and flows into the sand introduction passage 86 inside the bush 60f from each of the passage portions 94a to 94d.

The same effect as that of the sand molding device 10 can be obtained in the sand molding device 10f.

The bush used in the sand molding apparatus 10f may be formed with two or more passage portions so that the compressed air blown into the sand introduction passage 86 from each passage portion collides with each other.

10 g of a sand molding apparatus according to still another embodiment of the present invention will be described with reference to FIGS. 9A, 9B and 9C. FIG. 9A is a cross-sectional view schematically showing a main part of the sand molding apparatus 10g, and FIG. 9B is a cross-sectional view taken along the line GG'in FIG. 9A. FIG. 9C is a cross-sectional view schematically showing a bush 60 g of a sand molding device 10 g.

The sand molding apparatus 10g shown in FIGS. 9A, 9B and 9C includes a blow plate unit 56g instead of the blow plate unit 56f of the sand molding apparatus 10f shown in FIG. 8A and the like.

The blow plate unit 56 g includes a square plate-shaped blow plate 58 g and a hollow cylindrical bush 60 g. The blow plate 58 g has a passage portion 140. The bush 60g has a groove portion 142 and passage portions 144a and 144b.

The groove 142 of the bush 60g is formed in an annular shape on the outer circumference of the bush 60g. The passage portion 140 of the blow plate 58g is formed in a straight line so as to communicate the groove portion 142 and the front surface of the blow plate 58g. The groove portion 142 communicates the passage portion 140 of the blow plate 58g with the passage portions 144a and 144b of the bush 60g. The passage portions 144a and 144b of the bush 60g are formed so that the compressed air blown from the passage portions 144a and 144b into the sand introduction passage 86g collide with each other.

The sand introduction passage 86g is the same as the inlet portion 88 located on the blow head 48 side, the outlet portion 90 located on the molding mold 20 side, and the same diameter portion 93 extending downward from the inlet portion 88 and having the same inner diameter. It has a diameter-expanded portion 92 that extends downward from the diameter portion 93.

In the sand molding device 10g, a plurality of compressed air introduction passages are formed by the passage portion 140 of the blow plate 58g, the groove portion 142 of the bush 60g, and the passage portions 144a and 144b. Therefore, the groove 142 of the bush 60 g forms a part of these compressed air introduction passages.

As shown in FIG. 9C, the blow plate unit 56g has a vent plug 59 arranged in each of the passage portions 144a and 144b of the bush 60g (that is, in the portion of the compressed air introduction passage formed in the bush 60g). Have more.

By arranging the vent plug 59 in the portion of the compressed air introduction passage formed in the bush 60 g as in the present embodiment, the pneumatic device can be protected from the wet sand invading the compressed air introduction passage.

As a method of protecting the pneumatic equipment from the wet sand that invades the compressed air introduction passage, it is conceivable to wrap a filter (for example, wire mesh) around the outer circumference of the bush. However, if such a method is adopted, the filter is easily displaced when the bush is attached to the blow plate, and the workability is lowered. On the other hand, when the vent plug 59 is used as illustrated, such a problem does not occur.

Further, in the present embodiment, the bush 60g is a groove portion 142 formed in an annular shape on the outer periphery, and has a groove portion 142 forming a part of a plurality of compressed air introduction passages. As a result, one "first part" (a part formed in the blow plate 58g) of the compressed air introduction passage is compressed with respect to a plurality of "second parts" (a part formed in the bush 60g) through the groove portion. Can supply air. Therefore, it is not necessary to separately form the first portion in the blow plate 58 g with respect to the plurality of second portions formed in the bush 60 g. Therefore, when a plurality of sand introduction passages 86 g are provided in the blow plate unit 58 g, as shown in FIG. 10, a plurality of bushes 60 g can be arranged in close proximity to each other. On the other hand, when the groove portion 138 is provided in the blow plate 58f as in the sand molding apparatus 10f shown in FIG. 8A or the like, when a plurality of sand introduction passages 86g are provided, a space for providing the groove portion 138 for each sand introduction passage 86g. It is difficult to arrange a plurality of bushes 60f in close proximity to each other because it is necessary to secure the above. The number and arrangement of the plurality of bushes 60g (that is, the number and arrangement of the plurality of sand introduction passages 86) are not limited to the example shown in FIG.

In the above-described embodiment, the blowing direction X is downward (vertical direction), but the present invention is not limited to this. The blowing direction X may be diagonally downward.

Further, in the above-described embodiment, the bush has the enlarged diameter portion 92 and the same diameter portion 93, but is not limited thereto. In the bush, an enlarged diameter portion having an inner diameter widened from the inlet portion 88 to the outlet portion 90 may be formed. Further, the bush may be formed in a square cylinder shape.

The outlet of the compressed air introduction passage (the end on the sand introduction passage side) may be provided at the same diameter portion of the sand introduction passage, or may be provided at the enlarged diameter portion of the sand introduction passage.

The blow head and the blow plate unit may be integrally formed. Further, the blow plate unit and the molding die may be integrally formed.

As described above, the sand molding apparatus 10 according to the embodiment of the present invention is a sand molding apparatus that blows wet sand into the molding mold 20 to form a sand mold, and includes a blow head 48 that holds the wet sand. A blow plate unit 56 provided between the blow head 48 and the molding die 20 is provided, and the blow plate unit 56 is provided from the blow head 48 to the molding die by compressed air supplied to the blow head 48. A sand introduction passage 86 through which the wet sand blown into the 20 passes, and at least one compressed air introduction passage P1 for blowing compressed air toward the wet sand blown into the mold 20 through the sand introduction passage 86. (P2), the blowing direction X of the wet sand from the blow head 48 through the sand introduction passage 86 to the molding mold 20, and the at least one compressed air introduction passage P1 (P2). The angle D1 (D2) formed with the blowing direction Y1 (Y2) of the compressed air passing through the wet sand toward the wet sand is set to a sharp angle.

In the sand molding apparatus 10 according to the embodiment of the present invention, the wet sand blown from the blow head 48 toward the molding mold 20 is sanded by the compressed air blown from the compressed air introduction passage P1 (P2) of the blow plate unit 56. It is agitated in the introduction passage 86 and in the vicinity of the opening 26a of the molding die 20 and blown into the molding die 20 while being finely dispersed. The blowing direction X of the wet sand from the blow head 48 to the molding mold 20 through the sand introduction passage 86 and the blowing direction Y1 (Y2) of the compressed air toward the wet sand through the compressed air introduction passage P1 (P2). Since the angle D1 (D2) formed with the sand is set to a sharp angle, the compressed air from the compressed air introduction passage P1 (P2) acts to push the wet sand into the molding mold 20 from the rear, so that the molding mold The filling property of wet sand with respect to the cavity 24a of 20 is improved. Therefore, since the molding die 20 can be suitably filled with wet sand, even a sand mold having a complicated shape can be suitably molded.

In a certain embodiment, the sand introduction passage 86 includes an inlet portion 88 located on the blow head 48 side and an outlet portion 90 located on the molding mold 20 side, and the opening area Ao of the outlet portion 90 is defined as. It is larger than the opening area Ai of the entrance portion 88.

When the opening area Ao of the outlet 90 of the sand introduction passage 86 is larger than the opening area Ai of the inlet 88, the flow velocity of the wet sand passing through the sand introduction passage 86 becomes slower at the outlet 90 than at the inlet 88. .. Therefore, the wet sand collides with each other in the sand introduction passage 86 and is further agitated, and is further dispersed at the outlet portion 90 wider than the inlet portion 88. As a result, the straightness of the wet sand is lowered, and the lump of the wet sand can be prevented from sticking (sticking) to the molding mold 20, so that a molded product (sand mold) having good mold releasability can be obtained.

The other sand molding device 10 according to the embodiment of the present invention is a sand molding device that blows wet sand into the molding mold 20 to form a sand mold, and has a blow head 48 for holding the wet sand and the blow head. A blow plate unit 56 provided between the 48 and the mold 20 is provided, and the blow plate unit 56 is blown from the blow head 48 into the mold 20 by compressed air supplied to the blow head 48. A sand introduction passage 86 through which the wet sand passes, and at least one compressed air introduction passage P1 (P2) for blowing compressed air toward the wet sand blown into the mold 20 through the sand introduction passage 86. The sand introduction passage 86 includes an inlet portion 88 located on the blow head 48 side and an outlet portion 90 located on the molding mold 20 side, and the opening area Ao of the outlet portion 90 is , It is larger than the opening area Ai of the entrance portion 88.

In another sand molding apparatus 10 according to the embodiment of the present invention, the wet sand blown from the blow head 48 toward the molding mold 20 is driven by the compressed air blown from the compressed air introduction passage P1 (P2) of the blow plate unit 56. , Is stirred in the sand introduction passage 86 and in the vicinity of the opening 26a of the molding die 20 and is blown into the molding die 20 while being finely dispersed. Since the opening area Ao of the outlet 90 of the sand introduction passage 86 is larger than the opening area Ai of the inlet 88, the flow velocity of the wet sand passing through the sand introduction passage 86 is slower at the outlet 90 than at the inlet 88. Become. Therefore, the wet sand collides with each other in the sand introduction passage 86 and is further agitated, and is further dispersed at the outlet portion 90 wider than the inlet portion 88. As a result, the straightness of the wet sand is lowered, and the lump of the wet sand can be prevented from sticking (sticking) to the molding mold 20, so that a molded product (sand mold) having good mold releasability can be obtained.

In a certain embodiment, the opening area Ao of the outlet portion 90 is the opening area Ai of the inlet portion 88 and the diameter area Aa (Ab) of the outlet 95a (95b) of the at least one compressed air introduction passage P1 (P2). Greater than the sum of.

When the opening area Ao of the outlet 90 of the sand introduction passage 86 is larger than the sum of the opening area Ai of the inlet 88 and the diameter area Aa (Ab) of the outlet 95a (95b) of the compressed air introduction passage P1 (P2). Since the difference between the opening area Ai of the inlet portion 88 and the opening area Ao of the outlet portion 90 can be further increased, the wet sand passing through the sand introduction passage 86 can be further stirred and dispersed. Therefore, it is possible to further prevent the lump of wet sand from sticking to the molding die 20.

In certain embodiments, the wet sand comprises an inorganic binder.

Inorganic binders are generally binding. Therefore, when the wet sand contains an inorganic binder, if the wet sand adheres to the mold 20, it becomes difficult for the sand mold to be released from the mold 20, and if the mold is forcibly released, the sand mold may be broken. be. Since the opening area Ao of the outlet portion 90 is larger than the opening area Ai of the inlet portion 88, the wet sand can be sufficiently agitated and dispersed even when the wet sand contains an inorganic binder. , It is possible to preferably prevent the lump of wet sand from sticking to the mold 20.

In a certain embodiment, the at least one compressed air introduction passage is a plurality of compressed air introduction passages P1 and P2, and the plurality of compressed air introduction passages P1 and P2 are from the plurality of compressed air introduction passages P1 and P2. The compressed air blown in is formed so as to collide with each other.

By blowing compressed air from a plurality of compressed air introduction passages P1 and P2 so as to collide with each other, it is possible to further promote agitation and dispersion of wet sand. Therefore, the molding die 20 can be more preferably filled with wet sand.

In a certain embodiment, the blow plate unit 56 includes a blow plate 58 provided between the blow head 48 and the molding mold 20, and a hollow cylindrical bush 60, and the blow plate 58 is a blow plate 58. It has a communication hole for communicating the blow head 48 and the molding die 20, and the bush 60 is provided in the communication hole of the blow plate 58 and has the sand introduction passage 86.

When the blow plate unit 56 adopts a configuration having a blow plate 58 provided between the blow head 48 and the molding die 20 and a hollow cylindrical bush 60, the bush 60 provided in the communication hole of the blow plate 58 is provided. By simply replacing it, it is possible to easily correspond to the desired molding conditions, the type of molded body (sand mold) to be obtained, and the like.

In certain embodiments, the at least one compressed air introduction passage P1 (P2) is formed from the blow plate 58 to the bush 60.

The compressed air introduction passage P1 (P2) includes a "first portion" formed in the blow plate 50 and a "second portion" formed in the bush 60 (that is, a "first portion" formed in the blow plate 50). By simply replacing the bush 60, conditions such as the direction Y1 (Y2) of the compressed air blown into the sand introduction passage 86 can be easily changed.

In certain embodiments, the blow plate unit 56 further comprises a vent plug 59 disposed in a portion of the at least one compressed air introduction passage formed in the bush 60g.

By arranging the vent plug 59 in the portion (second portion) formed in the bush 60 g of the compressed air introduction passage, the pneumatic equipment can be protected from the wet sand invading the compressed air introduction passage.

In a certain embodiment, the at least one compressed air introduction passage is a plurality of compressed air introduction passages, and the bush 60g is a groove 142 formed in an annular shape on the outer periphery of the plurality of compressed air introduction passages. It has a groove 142 that constitutes a part.

When there are a plurality of compressed air introduction passages, if the bush 60g is a groove portion 142 formed in an annular shape on the outer periphery and has a groove portion 142 forming a part of the plurality of compressed air introduction passages, one. Compressed air can be supplied from the first portion to the plurality of second portions via the groove portion 142. Therefore, it is not necessary to separately form the first portion on the blow plate 58 with respect to the plurality of second portions formed on the bush 60 g. Therefore, when a plurality of sand introduction passages 86 g are provided in the blow plate unit 56, a plurality of bushes 60 g can be arranged in close proximity to each other.

According to the embodiment of the present invention, there is provided a sand mold molding apparatus capable of suitably filling the mold with wet sand when the wet sand is blown into the mold to mold the sand mold.

10, 10a, 10b, 10c, 10d, 10e, 10f, 10g Sand mold molding equipment 20, 20c, 20d, 20e Molding molds 26a, 26b, 116, 136 Openings 48 Blow heads 56, 56a, 56b, 56c, 56d, 56f , 56g Blow plate unit 58, 58a, 58f, 58g Blow plate 60, 60f, 60g, 96 Bush 62, 98 Communication holes 86, 86b, 86c, 86g Sand introduction passage 88, 108, 112 Entrance 90 Exit 95a, 95b Outlet Ai Inlet opening area Ao Outlet opening area Aa, Ab Outlet diameter area B, D1, D2 Angles P1, P2, P3, P4, P5, P6, P7, P8 Compressed air introduction passage X Wet condition Sand blowing direction Y1, Y2 Compressed air blowing direction

Claims (10)

1. It is a sand molding device that molds sand molds by blowing wet sand into the molding molds.
   A blow head that holds the wet sand and
   A blow plate unit provided between the blow head and the molding die,
   With
   The blow plate unit is
   A sand introduction passage through which the wet sand blown from the blow head into the molding die by compressed air supplied to the blow head, and a sand introduction passage through which the wet sand passes.
   At least one compressed air introduction passage that blows compressed air toward the wet sand that is blown into the mold through the sand introduction passage.
   Have,
   The direction of blowing the wet sand from the blow head through the sand introduction passage to the mold and the direction of blowing compressed air from the blow head toward the wet sand through the at least one compressed air introduction passage. A sand molding device whose angle is set to an acute angle.
2. The sand introduction passage includes an inlet portion located on the blow head side and an outlet portion located on the molding mold side.
   The sand molding apparatus according to claim 1, wherein the opening area of the outlet portion is larger than the opening area of the entrance portion.
3. It is a sand molding device that molds sand molds by blowing wet sand into the molding molds.
   A blow head that holds the wet sand and
   A blow plate unit provided between the blow head and the molding die,
   With
   The blow plate unit is
   A sand introduction passage through which the wet sand blown from the blow head into the molding die by compressed air supplied to the blow head, and a sand introduction passage through which the wet sand passes.
   At least one compressed air introduction passage that blows compressed air toward the wet sand that is blown into the mold through the sand introduction passage.
   Have,
   The sand introduction passage includes an inlet portion located on the blow head side and an outlet portion located on the molding mold side.
   A sand molding device in which the opening area of the outlet portion is larger than the opening area of the entrance portion.
4. The sand molding apparatus according to claim 2 or 3, wherein the opening area of the outlet portion is larger than the sum of the opening area of the inlet portion and the diameter area of the outlet of the at least one compressed air introduction passage.
5. The sand molding apparatus according to any one of claims 2 to 4, wherein the wet sand contains an inorganic binder.
6. The at least one compressed air introduction passage is a plurality of compressed air introduction passages.
   The sand molding apparatus according to any one of claims 1 to 5, wherein the plurality of compressed air introduction passages are formed so that compressed air blown from the plurality of compressed air introduction passages collide with each other.
7. The blow plate unit is
   A blow plate provided between the blow head and the molding die,
   Hollow cylindrical bush and
   Have,
   The blow plate has a communication hole for communicating the blow head and the molding die.
   The sand molding apparatus according to any one of claims 1 to 6, wherein the bush is provided in the communication hole of the blow plate and has the sand introduction passage.
8. The sand molding apparatus according to claim 7, wherein the at least one compressed air introduction passage is formed from the blow plate to the bush.
9. The sand molding apparatus according to claim 8, wherein the blow plate unit further has a vent plug arranged in a portion of the at least one compressed air introduction passage formed in the bush.
10. The at least one compressed air introduction passage is a plurality of compressed air introduction passages.
    The sand molding apparatus according to claim 8 or 9, wherein the bush is a groove portion formed in an annular shape on the outer periphery and has a groove portion forming a part of the plurality of compressed air introduction passages.
    
    
    
    

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