JPH09234547A - Mold forming device and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent the flow-out of molding sand from a nozzle after blowing the molding sand and to unnecessitate negative pressure source, etc., conventionally needed to prevent the flow-out of the molding sand. SOLUTION: In this mold forming device, the mold is formed by inserting the nozzle 14n by a prescribed depth to a molding sand blowing hole Ka in a forming mold K and blowing the molding sand into a cavity in the forming mold K from this nozzle with pressure gas. The device is provided with a molding sand discharging hole 14K formed on the side surface of the nozzle in the direction where the molding sand does not naturally drop, and guide means 14a, 14t, 14r for guiding the molding sand discharged from the molding sand discharging hole 14k to the front part of the nozzle 14n.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding die in which a molding sand is blown into a cavity of a molding die by inserting a nozzle into a molding sand blowing port at a predetermined depth and then pressurizing the molding sand from the nozzle. The present invention relates to a mold forming apparatus and a mold forming method for forming a mold.

[0002]

2. Description of the Related Art A conventional mold forming apparatus related to this is described in Japanese Patent Application Laid-Open No. 6-210401, and a longitudinal sectional view of a main part thereof is shown in FIG. The mold forming apparatus 1 includes a blow head (not shown) that collects molding sand on a blow plate 2, and a nozzle body 4 that is attached to the blow plate 2 and blows the molding sand in the blow head into a mold K. It has and. A male screw 4m is formed on the outer surface of the upper portion of the nozzle body 4, and the male screw 4m is screwed into the female screw hole 2w of the blow plate 2 so that the nozzle body 4 is blown by the blow plate 2.
Attached to In addition, the nozzle body 4 has a male screw 4
A flange portion 4f is provided below m, and a nozzle portion 4n is coaxially attached below the flange portion 4f.

An exhaust passage 4r is formed in the flange portion 4f in the radial direction, and the exhaust passage 4r communicates with a foundry sand passage 4t of the nozzle body 4 via an air vent 4a. A negative pressure source (not shown) is connected to the exhaust passage 4r. further,
A ring-shaped packing 4p for ensuring airtightness between the nozzle body 4 and the mold K is provided on the lower surface of the flange portion 4f.
Is installed.

In order to blow the molding sand into the mold K, first, the blow plate 2 is lowered with respect to the mold K to insert the nozzle portion 4n into the blowing port Ka of the mold K, and further,
The packing 4p of the flange 4f is brought into contact with the surface of the mold K. As a result, the space between the nozzle body 4 and the mold K is sealed, and the tip end surface of the nozzle portion 4n becomes substantially continuous with the cavity molding surface Kc. In this state, when compressed air is blown into the blow head, the molding sand is blown from the blow head into the cavity of the mold K through the molding sand passage 4t of the nozzle body 4. Then, when the blowing of the molding sand is completed, the compressed air supplied to the blow head is stopped. Also,
Negative pressure is applied to the exhaust passage 4r of the nozzle body 4, and the foundry sand in the foundry sand passage 4t is adsorbed by the air vent 4a and held at this position. This prevents the molding sand from flowing out of the nozzle body 4. Then, in this state, by raising the blow plate 2, the nozzle portion 4n is pulled out from the blowing port Ka of the mold K, and the blowing operation of the foundry sand is completed.

When the blowing operation of the foundry sand is completed, the blow plate 2, the nozzle body 4 and the like traverse and separate from the mold K, and a shaping pin (not shown) is inserted into the blowing port Ka of the mold K. To be done. Then, the shaping pin presses the molding sand that has flowed slightly out of the tip of the nozzle portion 4n and has a convex shape. In this way, when the mold (core) is molded after a predetermined time has elapsed, the mold K is opened and the mold is taken out. At this time, the core is pushed out of the mold K by the shaping pin or the like inserted into the blow-in port Ka of the mold K.

[0006]

However, the mold forming apparatus 1 uses a method of preventing the casting sand from flowing out from the nozzle body 4 by setting the exhaust passage 4r to a negative pressure, so that the compressed air source is used. Besides, a negative pressure source is required and the equipment cost increases. In addition, the outflow of the foundry sand may not be stopped due to the stop of the negative pressure source or the clogging of the air vent 4a, and the reliability is low. Further, in addition to the nozzle body 4 and the like, a shaping pin (pushing pin) and a drive mechanism therefor are also required, so that the equipment becomes large and the cost becomes high.

According to the first to fourth aspects of the present invention, the facility cost can be reduced by preventing the foundry sand from flowing out of the nozzle with a simple structure without providing a negative pressure source or the like. The purpose is to improve the reliability of the nozzle. The invention according to claim 5 is
In addition to the object of the invention described in claims 1 to 4, it is an object to effectively cool the nozzle so that molding sand does not solidify in the nozzle. The invention described in claim 6 and claim 7
In addition to the object of the invention as set forth in claim 5, by providing a nozzle or the like with the function of an extruding pin, the extruding pin conventionally required can be omitted, and the object is to make the equipment compact and reduce the cost. To do.

[0008]

The above-mentioned problems can be solved by a mold forming apparatus and a mold forming method having the following respective structures. That is, the mold molding apparatus according to claim 1 inserts a nozzle into the molding sand blowing port of the molding die to a predetermined depth, and blows molding sand into the cavity of the molding die from the nozzle by pressure gas. In the mold forming device for molding the mold, the molding sand is formed in the side surface of the nozzle by directing the direction in which the molding sand does not fall naturally, and the molding sand discharged from the molding sand discharge hole is the nozzle. And a guide means for leading forward. Claim 1
According to the mold forming apparatus described in, since the molding sand discharge hole is formed on the side wall surface of the nozzle so that the molding sand does not fall naturally, after the supply of the pressure gas is stopped, the molding sand is discharged from the nozzle. It does not flow out through the foundry sand discharge holes. Therefore, unlike the conventional case, a negative pressure source or the like for stopping the outflow of the foundry sand is not required, and the equipment cost can be reduced. Further, since the method of stopping the outflow of the foundry sand by setting the direction of the foundry sand discharge hole, the structure is simple and troubles such as failure are eliminated and the reliability of the nozzle is improved.
Further, since the molding sand discharged from the side surface of the nozzle can be guided to the front of the nozzle by the guide means, it is not necessary to project the tip of the nozzle into the cavity of the molding die. The foundry sand discharge holes include not only circular holes but also square holes and holes of various shapes.

The mold forming apparatus according to claim 2 is
In the mold forming device for inserting a nozzle to the molding sand blowing port of the molding die at a predetermined depth, and for molding the molding sand by blowing the molding sand into the cavity of the molding die from the nozzle by the pressure gas, the nozzle is The casting sand passage is formed in a spiral shape so that the casting sand does not naturally drop from the casting sand discharge hole of the nozzle. According to the molding apparatus of claim 2, since the foundry sand passage is formed in a spiral shape with a predetermined inclination so that the foundry sand does not fall naturally, the foundry sand is provided after the supply of the pressure gas is stopped. Does not flow out of the foundry sand discharge hole of the nozzle. Therefore, it is possible to obtain the same effect as that of the invention described in claim 1.

Further, the mold forming apparatus according to claim 3 is
In the mold forming device for inserting a nozzle to the molding sand blowing port of the molding die at a predetermined depth, and for molding the molding sand by blowing the molding sand into the cavity of the molding die from the nozzle by the pressure gas, the nozzle is A plug member for closing the molding sand discharge hole of the nozzle with its own weight, and a gas blowing means for lifting the plug sand from the molding sand discharge hole to open the molding sand discharge hole. To do. According to the molding apparatus of claim 3, when the blowing of the gas to the plug material is stopped, the molding sand discharge holes of the nozzles are blocked by these plug materials, so that the molding sand flows out from the nozzle. Disappears. Therefore, it is possible to obtain the same effect as that of the invention described in claim 1.

The mold forming apparatus according to a fourth aspect of the present invention is
In a molding machine for inserting a nozzle to a casting sand blowing port of a molding die at a predetermined depth, and blowing molding sand from the nozzle into a cavity of the molding die by a pressure gas to mold a casting mold, the casting of the nozzle It is characterized in that a mechanism for blowing a pressure gas from the sand discharge hole into the nozzle is provided. According to the molding apparatus of claim 4, by blowing the pressure gas into the nozzle from the molding sand discharge hole after blowing the molding sand, the molding sand left in the nozzle by this pressure gas is returned to the blow head side. be able to. Therefore, it is possible to prevent the molding sand from flowing out from the molding sand discharge hole of the nozzle. In addition, the method of blowing the molding sand into the nozzle by changing the flow of the pressure gas used to blow the molding sand into the molding die, which is a different driving source as in the past, is a method of blowing the molding sand into the nozzle. It eliminates the need for a pressure source and reduces equipment costs. Further, since the same driving source as that for blowing the molding sand is used to prevent the molding sand from flowing out, the reliability of the nozzle is also improved. Further, the trouble that the foundry sand hardens in the nozzle does not occur.

The mold forming apparatus according to a fifth aspect of the present invention is
The mold forming apparatus according to claim 1, 2 or 3, or 4, wherein a gas supply means for supplying a gas to a cylinder housing the nozzle and a gap between the cylinder and the nozzle. And have. According to the mold forming apparatus of the fifth aspect, the gas can be supplied to the gap between the cylindrical body and the nozzle, so that the nozzle can be cooled. For this reason, the trouble that the molding sand hardens in the nozzle hardly occurs. The tubular body includes not only a tubular body but also all tubular bodies such as a square tubular body.

The mold forming method according to claim 6 is
A nozzle is inserted at a predetermined depth to the molding sand blowing port of the molding die, and the molding sand is blown from the nozzle into the mold cavity by a pressure gas to mold the molding die, at the time of mold opening, It is characterized in that the mold is extruded from the molding die at the tip of the nozzle or the tip of the cylinder that houses the nozzle. According to the method of molding a mold according to claim 6, since the mold can be extruded by the nozzle or the cylinder that houses the nozzle, the extruding pin of the mold and the mechanism for moving the extruding pin are not required, and the equipment cost is reduced. Can be reduced.

The mold forming apparatus according to claim 7 is
The mold forming apparatus according to claim 1, 2 or 3, or 4 or 5, wherein a molded mold is pushed from a mold at the tip of the nozzle or the tip of the cylinder. It is characterized in that a pressing surface for taking out is formed. According to the casting apparatus of claim 7,
By pressing the mold with the pressing surface formed at the tip of the nozzle or the tip of the cylinder, the mold can be extruded from the mold. That is, it becomes possible to implement the invention described in claim 6 with the mold forming apparatus of the present invention.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A mold forming apparatus according to a first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Here, FIG. 1 is an overall vertical cross-sectional view of the mold forming apparatus according to the present embodiment, and FIG. 2 is a view taken in the direction of arrow II in FIG. The mold forming apparatus 10 includes a blow head 13 that collects the molding sand on the blow plate 12, and a nozzle body 14 that blows the molding sand in the blow head 13 into the mold K.

The blow head 13 is a container having a closed structure, and a replenishment pipe 13p for replenishing the foundry sand is connected to the upper surface of the container. The supply pipe 13p
Is provided with a valve 13v so that the inside of the blow head 13 can be maintained in a sealed state. In addition, the supply pipe 13
Next to p, an air pipe 13a for supplying compressed air into the blow head 13 is connected via an air valve 13b. An opening 13k is formed at the center of the lower surface of the blow head 13, and the nozzle portion 14n of the nozzle body 14 is vertically connected to the opening 13k.

The nozzle body 14 has a blow head 13
14n for passing the foundry sand from No. 1 and its nozzle 1
The outer cylinder 14t covers 4n, and the base end (upper part) of the outer cylinder 14t communicates with the blow pipe 14a provided on the lower surface of the blow head 13. A ring-shaped plate 14r having an opening having a diameter smaller than the outer diameter of the nozzle portion 14n is attached to the tip (lower end) of the outer cylinder 14t. Here, the blow pipe 1
Compressed air is supplied to 4a via a blow valve 14b.

The nozzle portion 14n of the nozzle body 14 is formed in a pipe shape, and its base end portion is connected to the opening 13k of the blow head 13 as described above. Also,
The tip (lower end) of the nozzle portion 14n has a conical lid 14e.
And a molding sand discharge hole 14k is formed at the joint between the lid 14e and the pipe. A plurality of foundry sand discharge holes 14k of the nozzle portion 14n are formed at equal intervals in the circumferential direction, and as shown in FIG. Here, the angle θ is set in consideration of the wall thickness t of the nozzle portion 14n so that the molding sand can form a repose angle α at the position of the molding sand discharge hole 14k. The angle of repose α of the foundry sand is about 25 °.

The nozzle body 14 is a blow plate 12
The nozzle body 14 is inserted into the open hole 12c of the blow plate 12, and the tip side of the nozzle body 14 projects below the blow plate 12 by a predetermined dimension. The space between the nozzle body 14 and the opening 12c of the blow plate 12 is sealed by a ring-shaped sealing material 12s. Further, on the lower surface of the blow plate 12, a ring-shaped crimp packing 12p is also mounted around the opening 12c. The blow plate 12 can be moved up and down together with the blow head 13 and the nozzle body 14 attached to the blow plate 12. Then, the blow plate 12 descends with respect to the mold K and the nozzle body 1
When the tip end of 4 is inserted into the blow-in opening Ka of the die K and the pressure-bonding packing 12p comes into contact with the surface of the die K, the blow-out opening Ka of the die K and the nozzle body 14 are sealed together. The tip surface of the nozzle body 14 becomes substantially continuous with the cavity molding surface Kc.

Next, the mold forming apparatus 1 according to the present embodiment.
The operation of 0 will be described. First, when the molding sand is supplied into the blow head 13 by the valve 13v, the blow plate 12 is lowered and the tip end side of the nozzle body 14 is inserted into the blowing port Ka of the mold K. Then, in a state where the pressure-bonding packing 12p of the blow plate 12 is in contact with the surface of the mold K, the lowering of the blow plate 12 is stopped and the space between the blow-in port Ka of the mold K and the nozzle body 14 is sealed. . Further, in this state, the tip surface of the nozzle body 14 becomes substantially continuous with the cavity molding surface Kc.

Next, the blow valve 14b is opened to allow compressed air to pass through the outer cylinder 14t, and the air valve 13b is opened to supply compressed air into the blow head 13. When compressed air is supplied into the blow head 13, the molding sand in the blow head 13 passes through the nozzle portion 14n and is extruded from the molding sand discharge hole 14k. Further, the molding sand pushed out from the molding sand discharge hole 14k is blown into the cavity of the mold K from the opening of the ring-shaped plate 14r of the outer cylinder 14t by the compressed air passed through the outer cylinder 14t.

In this way, when the molding sand is filled with the molding sand after a certain period of time, the air valve 13b is closed and the blow valve 14b is closed. As a result, no pressure is applied to the molding sand in the blow head 13, and the molding sand in the nozzle portion 14n forms a repose angle α at the position of the molding sand discharge hole 14k and the nozzle portion 14n.
The outflow of foundry sand from is stopped. In this state, the blow plate 12 is lifted to move the nozzle body 14
Is pulled out from the blow-in port Ka of the mold K. Then, when the blow head 13 and the nozzle body 14 are transported to the standby position, the blow valve 14b is opened and the outer cylinder 1 is opened.
Compressed air is passed through 4t to cool the nozzle body 14. That is, the nozzle portion 14n corresponds to the nozzle of the present invention, and the outer cylinder 14t, the blow pipe 14a, and the blow valve 1 are provided.
4b etc. function as a guide means and a gas supply means of the present invention.

As described above, according to the molding apparatus 10 of this embodiment, the molding sand discharge hole 14k of the nozzle portion 14n is formed.
Since the molding sand is manufactured so that the repose angle α can be formed at that position, the molding sand in the nozzle portion 14n does not flow out from the molding sand discharge hole 14k of the nozzle after the molding sand is blown. Further, since the angle of repose is used to prevent the casting sand from flowing out, there is no fear of failure and the reliability of the nozzle portion 14n is improved. Further, since a special drive source such as a negative pressure source which has been conventionally required for preventing the outflow of the foundry sand is not required, the facility cost can be reduced. In addition, the outer cylinder 14t
Since the molding sand discharged from the side surface of the nozzle portion 14n can be guided to the front of the nozzle portion 14n by such guide means, it is not necessary to project the tip of the nozzle body 14 into the cavity of the mold K. Further, the nozzle unit 1
Since 4n is cooled by the compressed air passing through the outer cylinder 14t, the trouble that the molding sand is hardened in the nozzle portion 14n hardly occurs.

[Second Embodiment] Next, a mold forming apparatus according to a second embodiment of the present invention will be described with reference to FIG. The mold forming device 30 according to the present embodiment is the first
The structure of the nozzle body 14 and the seal structure for the mold K in the mold forming apparatus 10 according to the second embodiment are modified, and other structures are the same as those of the mold forming apparatus 10 according to the first embodiment. is there. The nozzle body 34 of the mold forming apparatus 30 is formed in a tubular shape, and a plug 36 having a spiral groove 36m around the periphery thereof is inserted and fixed to the tip end portion thereof. The spiral groove 36m functions as a passage for foundry sand, and the inclination angle θ and the passage length of the spiral groove 36m are set to values such that the foundry sand can form a repose angle α.

Further, the nozzle body 34 has a plug 3
A disk-shaped flow straightening plate 38 is attached to the tip of 6. A plurality of through holes 38a are formed in the rectifying plate 38 in the circumferential direction, and the through holes 38a make it difficult for the foundry sand to diffuse. Therefore, the sand on the product surface can be adjusted, and no unevenness is formed on the surface when the product is completed. A flange-shaped seal member 3 is provided around the nozzle body 34.
9 is attached. The seal member 39 has a structure capable of sliding in the axial direction with respect to the nozzle body 34, and a seal ring 39 is provided between the seal member 39 and the nozzle body 34.
It is sealed by s. In addition, the seal member 3
The lower surface of 9 is a crimp packing 3 surrounding the blow-in opening Ka of the mold K.
9p is attached. That is, the through hole 38a formed in the rectifying plate 38 functions as the foundry sand discharge hole of the present invention.

Next, the mold forming apparatus 3 according to the present embodiment.
The operation of 0 will be described. First, when the molding sand is supplied into the blow head 33, the blow head 33 descends and the nozzle body 34 is inserted into the blowing port Ka of the mold K. The nozzle body 34 is further inserted into the blow-in port Ka of the mold K in a state where the crimp packing 39p of the seal member 39 is in contact with the surface of the mold K, and the tip end surface of the nozzle body 34 is a cavity molding surface. The lowering of the blow head 33 stops at a position where it is almost continuous with Kc.

Next, compressed air is supplied into the blow head 33, and the molding sand is blown into the cavity of the mold K through the through hole 38a of the nozzle body 34 by the pressure of the compressed air. Then, when the filling of the molding sand is completed, the supply of compressed air to the blow head 33 is stopped.
As a result, no pressure is applied to the foundry sand, the foundry sand forms a repose angle α at the position of the spiral groove 36 m of the nozzle body 34, and the outflow from the nozzle body 34 is stopped.

As described above, the method of stopping the outflow of the molding sand from the nozzle main body 34 by forming the angle of repose α in the molding sand at the position of the spiral groove 36m is adopted, so that there is no fear of failure and the nozzle is The reliability of the main body 34 is improved. Further, a special drive source such as a negative pressure source, which has been conventionally required, is not required. Further, since the tip of the nozzle body 34 has a flat portion, it can be used as a product extruding pin. Further, since the seal member 39 has a structure that can slide in the axial direction with respect to the nozzle body 34, the amount of insertion of the nozzle body 34 into the mold K can be adjusted.

[Third Embodiment] Next, a mold forming apparatus according to a third embodiment of the present invention will be described with reference to FIG. Here, FIG. 3 is a longitudinal sectional view of a main part of the mold forming apparatus according to the present embodiment. The mold forming apparatus 20 according to the present embodiment is the mold forming apparatus 10 according to the first embodiment.
The structure of the nozzle body 14 is modified, and other structures are the same as those of the mold forming apparatus 10 according to the first embodiment. The nozzle body 24 of the mold forming apparatus 20 is formed in a tubular shape, and a ring-shaped plate 24r having an opening 24k is fixed to the tip of the nozzle body 24. Further, a disc-shaped first metal net 24a is attached on the ring-shaped plate 24r, and a plurality of steel balls 25 are stored on the first metal net 24a so as to be movable upward. However, in the state where no force is applied to push up the steel balls 25, the steel balls 25 are densely packed at the tip of the nozzle body 24 due to their own weight, and no gap is formed through which the molding sand can pass.

A small air pipe 26 is arranged inside the nozzle body 24 in parallel with the inner wall surface, and an air outlet 26a is formed on the tip side surface of the small air pipe 26. The air outlet 26a is the air outlet 2
The air blown out from 6a is directed in a direction in which each steel ball 25 can be pushed up. Therefore, when the air is blown out from the air outlet 26a, each steel ball 25 bounces and a gap is created between the steel balls 25 so that the foundry sand can pass through the gap. Further, above the position of the steel balls 25, a second wire netting 24b is attached to prevent the steel balls 25 from jumping up. That is, the plurality of steel balls 25 correspond to the plug material of the present invention, and the small air piping 26 corresponds to the gas spraying means of the present invention. The opening 24k at the tip of the nozzle body 24 and the first wire netting 24a correspond to the foundry sand discharge hole of the present invention.

Next, the mold forming apparatus 2 according to the present embodiment.
The operation of 0 will be described. First, when the molding sand is supplied into the blow head, the blow plate 22 descends and the tip side of the nozzle body 24 is inserted into the blow-in port Ka of the mold K. Then, the compression packing 2 of the blow plate 22
With 2p in contact with the surface of the mold K, the lowering of the blow plate 22 is stopped, and the space between the blower opening Ka of the mold K and the nozzle body 24 is sealed. Further, in this state, the tip end surface of the nozzle body 24 is the cavity molding surface K.
It becomes almost continuous with c.

Next, compressed air is passed through the small air pipe 26, and each steel ball 25 is pushed up by the air blown from the air outlet 26a, and the opening of the nozzle body 24 is opened. Further, by supplying compressed air into the blow head, the molding sand in the blow head is blown into the cavity of the mold K through the opening of the nozzle body 24 which is opened. In this way, when the molding sand is filled in the mold K after a certain period of time, the supply of compressed air to the blow head and the small air pipe 26 is stopped. As a result, the openings 24k of the nozzle body 24 are closed by the steel balls 25, and the outflow of the foundry sand from the nozzle body 24 is stopped.

As described above, when the blowing of the air to the steel balls 25 is stopped, the openings 24k of the nozzle body 24 are blocked by the steel balls 25, so that the casting sand is blown by the casting sand after the blowing of the casting sand. There will be no outflow from 24. That is, a special drive source such as a negative pressure source, which has been conventionally required to prevent the foundry sand from flowing out, becomes unnecessary.

[Fourth Embodiment] Next, a mold forming apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. The mold forming device 40 according to the present embodiment includes a blow head 43 for accumulating foundry sand, and the blow head 43.
And a nozzle body 44 for blowing the molding sand therein into the mold K. The blow head 43 is a container having a closed structure, and an air pipe 43a for supplying compressed air into the container 43 is connected to the upper surface of the blow head 43. Further, the air pipe 43a has an air valve 43b and an air release valve 4
3x and is installed. An opening 43k is formed in the blow head 43 just below the fall prevention plate 43d.
The nozzle portion 44n of the nozzle body 44 is connected to the opening 43k.

The nozzle body 44 has a blow head 43.
It is composed of a pipe-shaped nozzle portion 44n for passing the molding sand from No. 4 and an outer cylinder 44t covering the nozzle portion 44n. The outer cylinder 44t is a member for air-cooling the nozzle portion 44n and returning the molding sand in the nozzle portion 44n to the blow head 43 side, and the tip of the outer cylinder 44t is shown in FIG. 5 (C). As shown in FIG. In addition, the outer cylinder 44
An orifice-shaped plate 44f is attached to the inner side of the front end of t, and the base end (upper part) of the outer cylinder 44t is further mounted.
In the blow head 43, as shown in FIG.
Blow piping 44a provided on the lower surface of is connected. Here, compressed air is supplied to the blow pipe 44a from a blow valve (not shown).

On the lower surface of the blow head 43, a ring-shaped pressure-bonding packing 43p is mounted so as to surround the nozzle body 44, and the nozzle body 44 is provided with a blow port Ka of the mold K.
The blow-in port K with a predetermined amount inserted into
It is possible to seal between a and the nozzle body 44.

Next, the mold forming apparatus 4 according to the present embodiment.
The operation of 0 will be described. First, when the molding sand is supplied to the blow head 43, the blow head 43 descends and the nozzle body 44 is inserted into the blowing port Ka of the mold K. Then, in a state where the pressure-bonding packing 42p of the blow head 43 is in contact with the surface of the mold K, the lowering of the blow head 43 is stopped, and the blowing port Ka of the mold K and the nozzle body 4 are stopped.
4 is sealed. Further, in this state, the tip surface of the nozzle body 44 becomes substantially continuous with the cavity molding surface Kc.

Next, the air valve 43b is opened with the atmosphere release valve 43x of the blow head 43 closed, and compressed air is supplied into the blow head 43. As a result, the molding sand in the blow head 43 is pressed, passes through the opening 43k, and is blown into the cavity of the mold K through the nozzle portion 44n. In this way, when the molding sand is filled with the molding sand, the air valve 43b is closed and the atmosphere opening valve 43x is opened. Next, compressed air is supplied from the blow valve to the blow pipe 44a, and the air is caused to flow to the outer cylinder 44t of the nozzle body 44. Then, the air is bent inside the outer cylinder 44t by the ring-shaped plate 44f as shown by the arrow in FIG. 5C, and is blown inside from the tip of the nozzle portion 44n. As a result, the foundry sand in the nozzle portion 44n is blown up into the blow head 43 and is collected by the blow head 43.

As described above, after the molding sand is blown, the molding sand left in the nozzle portion 44n is returned to the blow head 43 by the air pressure, so that the molding sand is not hardened in the nozzle portion 44n. . Further, the mechanism for preventing the outflow of the foundry sand from the nozzle portion 44n becomes simple, and a special drive source such as a negative pressure source which is conventionally required is not necessary.

[Fifth Embodiment] Next, FIGS.
A mold forming apparatus according to a fifth embodiment of the present invention will be described based on FIG. Mold forming apparatus 50 according to the present embodiment
Is a blow head 53 for accumulating the molding sand, and a nozzle body 60 for blowing the molding sand in the blow head 53 into the mold K.
And The blow head 53 is a container having a hermetic structure including a horizontal blow plate 53p and a case 53c that covers the blow plate 53p. The case 53c has an upper surface for supplying compressed air into the container 53. The air pipe 53a is connected to an exhaust pipe 53x for opening the inside of the container 53 to the atmosphere. An air valve 53b is provided in the middle of the air pipe 53a.
Is attached, and an atmosphere release valve 53y is attached in the middle of the exhaust pipe 53x. An opening 53k is formed in the blow plate 53p just below the fall prevention plate 53d, and the nozzle body 60 is connected to the opening 53k.

The nozzle body 60 has a blow head 53.
It is composed of a pipe-shaped nozzle portion 62 through which the foundry sand of FIG. The nozzle portion 62 is a straight pipe having a flange 62f at the upper end, and the flange 62f allows the blow plate 5
It is vertically connected to the position of the opening 53k of 3p. The outer cylinder 64 is a member having a structure substantially the same as the outer cylinder 44t in the fourth embodiment, and is connected to an unillustrated pushing mechanism. Then, the outer cylinder 64 can be moved up and down independently of the nozzle portion 62 by the operation of the pushing mechanism. This allows the outer cylinder 64 to extrude the molded mold w from the mold K.

A ring portion 64r is formed on the outer cylinder 64, and the nozzle portion 6 is provided on the ring portion 64r.
2 is slidably inserted coaxially. A first seal ring 64s is mounted inside the ring portion 64r to seal between the outer cylinder 64 and the nozzle portion 62. In addition, the ring portion 64 of the outer cylinder 64
r is a short tube 6 that connects the inside and outside of the outer cylinder 64 to each other.
4b is formed in the radial direction, and an air blow pipe (not shown) is connected to the short pipe 64b. Further, an orifice-shaped plate 64f serving as a pressing surface when the mold is extruded from the mold K is attached to the tip (lower end) of the outer cylinder 64.

The outer cylinder 64 is adapted to be inserted into the through hole 56k of the crimping plate 56 for sealing the blow-in port Ka of the mold K. The crimping plate 56 is provided with a second seal ring 56s for sealing between the outer cylinder 64 and the crimping plate 56 on the inner wall surface of the through hole 56k.
A pressure-bonding packing 56p for sealing between the mold K and the pressure-bonding plate 56 is provided around the lower side of k.

Next, the mold forming apparatus 5 according to the present embodiment.
The operation of 0 will be described based on FIGS. When the molding sand is supplied to the blow head 53 and the mold K is clamped, compressed air is supplied from the air blow pipe into the outer cylinder 64 of the nozzle body 60. As a result, as shown in FIG. 7, air is allowed to pass between the outer cylinder 64 of the nozzle body 60 and the nozzle portion 62, and the nozzle portion 62 is cooled.

Next, the blow head 53 and the pressure bonding plate 5
6 is lowered and the nozzle body 60 is inserted into the blow-in port Ka of the mold K, and the pressure-bonding packing 56p of the pressure-bonding plate 56 is also inserted.
Comes into contact with the surface of the mold K. In this state, the tip end surface of the nozzle body 60, that is, the portion of the plate 64f of the outer cylinder 64 becomes substantially continuous with the cavity molding surface Kc, and the blower opening Ka of the mold K and the nozzle body 6 are made.
The space between 0 and 0 is sealed. The plate 64f portion of the outer cylinder 64 is similar to that of the fourth embodiment.
The dimension D is projected from the tip of the nozzle portion 62.

Next, when the supply of compressed air from the air blow pipe to the nozzle body 60 is stopped and the atmosphere opening valve 53y of the blow head 53 is closed, the air valve 53b of the blow head 53 is opened. Be done. As a result, compressed air is supplied into the blow head 53, and as shown in FIG.
The molding sand in 3 passes through the opening 53k and is blown into the cavity of the mold K through the nozzle portion 62 of the nozzle body 60. In this way, when the mold K is filled with the molding sand, the air valve 53b is closed and the air release valve 53y is opened.
Is opened. Next, compressed air is supplied to the nozzle body 60 from the air blow pipe, and air is caused to flow between the outer cylinder 64 and the nozzle portion 62. Then, the air is bent inside the outer cylinder 64 by the plate 64f as shown by the arrow in FIG. 9, and is blown into the inside from the tip of the nozzle portion 62. As a result, the foundry sand in the nozzle portion 62 is blown up into the blow head 53, and the blow head 53
Will be collected.

In this way, when the casting sand is solidified and the mold w is molded after a predetermined time elapses, the mold K is opened. At this time, as shown in FIG. 10, the pushing mechanism operates to lower the outer cylinder 64 of the nozzle body 60, and the mold w is pressed by the outer cylinder 64 and pushed out of the mold K. For this reason, the push pin and the mechanism for moving the push pin, which have been conventionally required, are not required, and the equipment can be made compact and the cost can be reduced.

Although the embodiments of the present invention have been described above, the embodiments of the present invention have the following various technical matters in addition to the technical matters described in the claims. Is added. (1) In the mold forming apparatus according to claim 1, the guide means includes a tubular body that houses the nozzle, and a gas supply means that supplies gas to a gap between the tubular body and the nozzle.
A mold forming apparatus comprising: Therefore, not only can the molding sand be guided to the front of the nozzle, but also the nozzle can be cooled. (2) In the molding apparatus according to claim 2, the molding sand passage is formed by inserting a plug having a spiral groove at the tip of the nozzle. Therefore, the inclination and length of the foundry sand passage can be freely set. (3) In the molding apparatus according to the fourth aspect, an outer cylinder through which gas is passed is provided around the nozzle, and the tip of the outer cylinder projects beyond the tip of the nozzle. Mold forming equipment. Therefore, for the nozzle,
Gas can be blown efficiently with a simple structure.

[0049]

According to the present invention, since the molding sand in the nozzle does not flow out from the opening of the nozzle after the molding sand is blown, it is conventionally necessary to prevent the molding sand from flowing out. No special drive source such as a pressure source is required, which reduces equipment costs and improves nozzle reliability.

[Brief description of drawings]

FIG. 1 is an overall vertical cross-sectional view of a mold forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a view taken in the direction of the arrow II in FIG.

FIG. 3 is a longitudinal sectional view of a main part of a mold forming apparatus according to a second embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of an essential part of a mold forming apparatus according to a third embodiment of the present invention.

FIG. 5 is an overall vertical cross-sectional view of a mold forming apparatus according to a fourth embodiment of the present invention.

FIG. 6 is an overall vertical cross-sectional view of a mold forming apparatus according to a fifth embodiment of the present invention.

FIG. 7 is a vertical cross-sectional view showing an operation of the mold forming apparatus according to the fifth embodiment of the present invention.

FIG. 8 is a vertical cross-sectional view showing an operation of the mold forming apparatus according to the fifth embodiment of the present invention.

FIG. 9 is a vertical cross-sectional view showing an operation of the mold forming apparatus according to the fifth embodiment of the present invention.

FIG. 10 is a vertical cross-sectional view showing an operation of the mold forming apparatus according to the fifth embodiment of the present invention.

FIG. 11 is a longitudinal sectional view of a main part of a conventional mold forming apparatus.

[Explanation of symbols]

 K Mold (molding die) Ka Blowing port α Angle of repose 14 Nozzle body 14n Nozzle portion 14k Foundry sand discharge hole 14t Outer cylinder (guide means, gas supply means) 14a Blow piping (guide means, gas supply means) 14b Blow valve ( Guide means, gas supply means) 24k Opening hole (casting sand discharge hole) 24a First wire mesh (casting sand discharge hole) 25 Steel ball (plug material) 26 Small air piping (gas blowing means) 36 Plug 36m Spiral groove ( Foundry sand passage) 38a Through hole (foundry sand discharge hole) 64 Outer cylinder 64f Plate (pressing surface)

Front Page Continuation (72) Inventor Kiyoshi Iwata 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (72) Inventor Setsuzo Takahashi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Koji Sano Toyo Sanki Co., Ltd. 84 Kawazoe, Otakamachi, Midori-ku, Nagoya, Aichi

Claims (7)

[Claims] 1. A mold forming apparatus for forming a mold by inserting a nozzle into a molding sand blowing port of a molding die to a predetermined depth and blowing molding sand into the cavity of the molding die from the nozzle by pressure gas. A casting sand discharge hole formed on the side surface of the nozzle in a direction in which the casting sand does not naturally fall, and guide means for guiding the casting sand discharged from the casting sand discharge hole to the front of the nozzle. A mold forming apparatus characterized by having. 2. A mold forming apparatus for forming a mold by inserting a nozzle into a molding sand blowing port of a molding die to a predetermined depth and blowing molding sand into the cavity of the molding die from the nozzle by pressure gas. A molding machine, wherein a molding sand passage is formed in a spiral shape in the nozzle so that the molding sand does not naturally drop from a molding sand discharge hole of the nozzle. 3. A mold forming apparatus for forming a mold by inserting a nozzle into a molding sand blowing port of a molding die to a predetermined depth and blowing molding sand from the nozzle into the cavity of the molding die by pressure gas. The nozzle is provided with a plug material that closes the molding sand discharge hole of the nozzle with its own weight, and a gas blowing unit that lifts the plug sand from the molding sand discharge hole to open the molding sand discharge hole. A mold forming device characterized in that 4. A mold forming apparatus for forming a mold by inserting a nozzle into a molding sand blowing port of a molding die to a predetermined depth and blowing molding sand from the nozzle into a cavity of the molding die by pressure gas. A mold forming apparatus comprising a mechanism for blowing a pressure gas into the nozzle from a molding sand discharge hole of the nozzle. 5. The mold forming apparatus according to claim 1, 2, 3 or 4, wherein a gas is stored in a tubular body that houses the nozzle, and a gap between the tubular body and the nozzle. And a gas supply means for supplying the gas. 6. A mold molding method in which a nozzle is inserted into a molding sand blowing port of a molding die to a predetermined depth, and molding sand is blown into the cavity of the molding die from the nozzle by the molding gas to blow molding sand from the nozzle. A method of molding a mold, wherein a mold is extruded from a mold at the tip of a nozzle or the tip of a cylinder that houses the nozzle when the mold is opened. 7. The mold forming apparatus according to claim 1, 2 or 3, or 4 or 5, wherein a mold is formed at the tip of the nozzle or the tip of the cylindrical body. A mold forming apparatus, wherein a pressing surface for extruding the mold from the mold is formed.