JPS623703B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a gas-curing mold making device that blows molding sand into a mold using compressed air to form a mold, and then hardens the mold by blowing hardening gas into the mold. In particular, the present invention relates to a molding apparatus having a feature of shaping means for a mold surface at an injection port of a mold.

BACKGROUND ART A gas-curing mold making apparatus includes (a) a mold having a cavity for molding a mold and a blowing port communicating with the cavity, (b) a mold opening/closing device for opening and closing the mold, and (c) Usually, it is constructed to include a sand blowing device having a sand blowing nozzle that can be brought into close contact with the blowing port, and (d) a hardening gas supply device having a gashing head that can be brought into close contact with the blowing port.

In this molding device, the sand blowing nozzle is separated from the blowing port after sand is blown into the sand, but this alone does not make the mold surface inside the blowing port flat. For this reason, after the sand blowing nozzle is separated from the blowing port, it is common practice to scrape the surface of the mold inside the blowing port with a scraping device. but,
This work is troublesome, and the leveled surface of the mold often remains uneven and has a poor texture, which often requires repair after molding.

Japanese Patent Publication No. 50-38056 describes a method that can solve this problem. After the sand blowing nozzle is separated from the blowing port of the mold, an extrusion pin for extruding the mold is inserted into the blowing port to flatten the surface of the mold inside the blowing port.

Problems to be Solved by the Invention In this way, the mold surface inside the nozzle can be easily shaped. However, if the mold making device is a gas hardening type, after shaping, the ejector pin should be removed from the nozzle. After removing it from the mold and retracting it to a position where it does not get in the way, the gashing head is brought into close contact with the blowing hole to blow in hardening gas, and after curing, the ejecting pin is inserted into the blowing hole again to push the mold out of the cavity. This creates a problem in that it takes extra time to move the extrusion pin, lengthens the molding cycle time, and reduces work efficiency.

Means for solving the problem The present invention has been made with the aim of solving this problem, and for that purpose, the above-mentioned (a) type, (b) type
In a gas curing mold making device equipped with a mold opening/closing device, (c) a sand blowing device, and (d) a curing gas supply device,
A pressing member is inserted into the gas outlet of the gas supplying head of the curing gas supply device to flatten the mold surface within the injection port, with the gas supplying head in close contact with the injection port. The pressing member is attached via an actuator that moves the pressing member between an operating position where it is inserted into the air inlet and a retracted position where it is removed from the air inlet.

Function In the mold making device according to the present invention, after the sand blowing device blows sand into the blowing port of the mold and the sand blowing nozzle is separated from the blowing port, the gassing head is brought into close contact with the sand blowing port. It will be done. At this point, the pressing member is held in the retracted position, but after the gushing head is brought into close contact with the inlet, the actuator is operated to fit the pressing member into the inlet, and the mold is placed inside the inlet. Shape the surface flat. Subsequently, the pressing member is moved to the retracted position, the blowing port is opened with a sufficient flow path area, and then the hardening gas is injected.

Effects of the Invention As described above, since the mold surface is shaped by the pressing member while the gushing head remains in close contact with the blowing port, the moving distance of the pressing member is extremely small, and the above-mentioned extrusion Compared to the case using pins, the time required to shape the mold surface is significantly shortened, and the efficiency of molding work can be improved.

Further, since the moving distance of the pressing member is small, the actuator can be simple with a small stroke, and the above effects can be obtained while avoiding a significant increase in device cost.

It is also possible to shape the mold surface by disposing the pressing member in a relatively immovable manner on the gassing head, but in this case, the pressing member remains in the inlet when hardening gas is injected, and the pressing member While it is necessary to supply the curing gas from the gap between the outer circumferential surface and the inner circumferential surface of the blowing port, in the molding device according to the present invention, the pressing member is removed from the blowing port when curing gas is injected. , the curing gas can be supplied to the inlet at a sufficient flow rate.

Embodiment Hereinafter, an example of the case where the present invention is applied to a gas-curing mold-making apparatus for molding a core will be described based on the drawings.

In the horizontally split side-blow type core making apparatus shown in FIG. 1, reference numeral 2 denotes a bed, on which a lower die plate 4 is fixed. A lower mold 6 is removably attached to the lower die plate 4, and an upper mold 8 is arranged above it. Upper mold 8
is removably attached to the upper mold die plate 10, and this upper mold die plate 10 is fixed to a rod 16 of a mold opening/closing cylinder 14 installed on the upper plate 12. ,
The lower mold 6 and the upper mold 8 are opened and closed. The upper board 12 is integrally connected to the bed 2 by a machine frame 18. In the mold closed state, a cavity 20 corresponding to the core to be molded is formed by the lower mold 6 and the upper mold 8, and the mold 6,
A blowing port 22 for blowing molding sand or hardening gas into the cavity 20 is formed on the mold matching surface 8 in a direction perpendicular to the mold opening/closing direction.

A blow head 24 for supplying molding sand is provided on the sides of the lower mold 6 and upper mold 8. The blow head 24 is arranged such that the blow port 26 at its tip is concentric with the blow port 22 formed by the lower mold 6 and the upper mold 8. Above this blow head 24 is a hopper 28 that accommodates foundry sand.
The blow head 24 is supported along with the hopper 28 so as to be movable in the horizontal direction by rollers 34 on a rail 32 fixed to the machine frame 18 and an arm 30 extending downward from the upper plate 12. There is. The blow head 24 has a rod 38 of a blow head moving cylinder 36 attached to the machine frame 18.
is fixed, and the blow head 24 is driven by a cylinder 36 to be advanced toward the blowing openings 22 of the molds 6, 8, or to be retracted from its advanced position.

Note that when the blowhead 24 is in the retracted position, sand is dropped into the blowhead 24 by a shutter (not shown) that communicates with the hopper 28 when the blowhead 24 is in the retracted position, but when it is in the forward position, the communication between the two is cut off. , sand can be blown into the mold cavity 20 from the blow head 24 using blown air. blow head 24
A blow air supply hose 39 for this purpose is connected to the blow head 2, and the blow air pressurized and compressed by a compressor etc. is supplied to the blow head 2 through this hose 39.
4 will be introduced.

A cylinder 40 for raising and lowering the gassing head is fixed to the upper plate 12, and a rod 42 of this cylinder 40
An elevating frame 44 is fixed to the tip. A gassing head 46 is attached to the lifting frame 44.
is guided by a guide member (not shown) so as to be able to slide in the horizontal direction (in the left-right direction in FIG. Insert between
Will be taken off. The amount of vertical movement is such that when the gushing head 46 is at the lower limit position, the mold blowing port 22
It is set up so that it can face the

A gas supply hose 48 is attached to the gassing head 46.
is connected, and a curing gas generated by a gas generator (not shown) is guided to the gassing head 46 through this gas supply hose 48. TEA (triethylene amine) gas is used as the curing gas, and the above-mentioned foundry sand is mixed with appropriate resins added and kneaded accordingly.

By the way, the blow head 24 also shown in FIG.
needless to say, functions as a sand blowing nozzle, but as is clear from FIG. It is designed so that two cores can be obtained in one molding process. Correspondingly, the blow head 24 is also provided with a pair of sand blowing sections, so that sand can be blown into each of the cavities 20 at the same time.

During sand blowing, each tip of the blow head 24 is fitted into the blow ports 22 of the molds 6 and 8, each having a circular cross section. As shown in FIG. 2, the tip of the blow head 24 is formed into a stepped cylindrical shape, and the outer diameter of the fitting portion 50 closest to the tip is slightly smaller than the diameter of the mold blowing port 22. The inset part 5
A shoulder surface 52 is formed next to the blow head 24, and this shoulder surface 52 closely contacts and contacts the end surfaces of the molds 6 and 8 around the blow port 22, thereby regulating the fitting dimension of the blow head 24. This amount of insertion is set to be slightly shallower than the core dimension, and the limit of the amount of sand blown into the cavity 20 is such that the end surface of the blown sand almost matches the opening end surface of the blowing port 26 of the blow head 24. Or, it is adjusted so that it slightly enters the inside of the air inlet 26. Note that the blown air that is blown into the cavity 20 together with the sand is from the mold 6,
The material is released from the mold through a number of air bands (not shown) formed at 8.

As shown in FIGS. 2 and 3, the blow head 24
The gashing head 46, which is provided between the molds 6 and 8, is shaped like a container and is provided with a gas outlet 53 that is open to the molds 6 and 8. A movable plate 54 is fitted inside the gas outlet 53,
A pair of pressing heads 56 for shaping the inlet trace are fixed to both ends of the movable plate 54 so as to protrude toward the molds 6 and 8.

The movable plate 54 and the pressing head 56 are provided so as to be movable relative to the gushing head 46 in a direction parallel to the center line of the blowing ports 22 of the molds 6 and 8.
It is connected via a movable plate 54 to one end of a bellows 58 disposed therein. The movable plate 54 is in a state parallel to the opening surface of the air inlet 22,
The front end of the bellows 58 is fixed at the center, and the rear end of the bellows 58 is fixed to the center of the inner wall of the gassing head 46.

Pressurized air is supplied into the bellows 58 from a pressure source (not shown) through an air passage 60 formed in the gassing head 46 and an air supply/discharge hose 62 connected to the air passage 60. By switching a pressure source or a valve provided in the air supply path, air is discharged from the inside of the bellows 58, which contracts based on its own elasticity, through the hose 62 and the like. Based on the expansion and contraction of the bellows 58 in the center line direction as the air is supplied and discharged, the movable plate 54 and the pressing head 56 are horizontally moved toward the molds 6 and 8, independently of the operation of the gushing head 46. to be made to do so, or to be kept away from it.

The pressing head 56 is driven by a bellows 58 and fitted into the blowing ports 22 of the molds 6 and 8 after sand is blown into the sand. Therefore, it has a circular cross-sectional shape corresponding to the shape of the blow-in ports 22, and its center line is parallel to that of each blow-in port 22 and is spaced apart by the same distance. Also, the pressing head 5
The outer diameter of the blower 6 is of course slightly smaller than the diameter of the inlet 22, but is of course larger than the diameter of the inlet 26 of the blow head 24.

The fitting dimensions of the pressing head 56 are the same as those of the movable plate 5.
The front surface of the mold 4 is regulated by coming into contact with the end surface around the blowing port 22 of the molds 6 and 8, and the press head 56 is regulated so as to match the outer dimensions of the molded core.
The dimensions of the core of the inlet hole are set with high accuracy by inserting and sand pressing.
This is slightly deeper than the fitting dimension of the blow head 24, and therefore, the sand at the blow hole trace is pushed into the cavity 20 that much deeper, resulting in a further improvement in sand filling performance.

The above pressing force is applied to the pressing head 56 by:
Although the bellows 58 is as described above, the bellows 5
By using 8 as an actuator,
Compared to cylinders, etc., the structure is simpler and more compact, sufficient pressing force can be obtained, and the pressing mechanism can be constructed at low cost with fewer troubles. The working surface 64 of the pressing head 56 that presses sand is shown in FIGS. 2 and 3.
As is clear from the figure, it has a planar shape perpendicular to the center line of the blowing port 22, but it can be changed as appropriate depending on the end face shape of the intended core.

A pair of guide pins 66 are erected at the lower corners of both ends of the movable plate 54 in the vicinity of the pressing head 56. The guide pin 66 protrudes toward the molds 6 and 8, and the press head 5
6 etc. are provided parallel to the direction in which they are moved, and their tips are tapered. on the other hand,
As shown in FIG. 3, the lower mold 6 near the air inlet 22
A pair of guide pin holes 68 are formed in which each of the guide pins 66 can fit. When the press head 56 is inserted into the air inlet 22, the engagement between the guide pin 66 and its pin hole 68 causes
The pressure head 56 is positioned and guided. As a result, the pressing head 5
6 and the air inlet 22 can be aligned with high precision, and the clearance between them for easy fitting can be minimized. As a result, a highly accurate molded surface can be obtained without any protrusion (burr) occurring on the molded surface formed by the blow hole traces caused by the pressing head 56.

The opening end surface of the gassing head 46 has a
The seal member 7 surrounds the movable plate 54.
0 is attached. The seal member 70 is brought into close contact with the periphery of the blowing port 22 when the gashing head 46 itself is moved toward the molds 6 and 8, and controls the movement limit of the gashing head 46. It serves to maintain airtightness between the blowing ports 22 of the molds 6 and 8 and the gassing head 46 when hardening gas is blown into the molds. Furthermore, a sufficient clearance is provided between the inner surface of the opening of the gas outlet 53 of the gassing head 46 and the movable plate 54 to allow passage of the hardening gas, from which the gas is blown out.

The cylinder 36 shown in FIG. 1 which drives the blow head 24 and the like is also used as a drive mechanism for moving the gassing head 46 toward and away from the molds 6 and 8. That is, gassing head 4
6 is brought close to and in close contact with the air inlet 22, the back surface 72 of the gashing head 46 in the lowered state
When the tip of the blow head 24 is brought into contact and pushed forward, while it is moved away from the blowing port 22,
An engaging member 74, shown in FIG. , it is starting to pull back. When the blowhead 24 moves forward, the engagement member 74 and the blowhead 24 are allowed to move relative to each other without interfering with each other.

Next, the operation of the apparatus configured as described above will be explained.

As shown in FIG. 1, when the upper mold 8 and the lower mold 6 are clamped by the mold opening/closing cylinder 14 and the gushing head 46 is in the raised position, the blow head 24 is first moved from its moving cylinder 36. The insertion portion 5 shown in FIG. 2 is moved forward by the actuation.
0 is fitted into the inlet 22 of the molds 6 and 8, and the shoulder surface 52 is brought into close contact with the periphery of the inlet 22. In this state, blown air is introduced into the blow head 24 from the blown air supply hose 39 shown in FIG.
At this time, communication between the hopper 28 and the blow head 24 is cut off as described above.

When the sand is sufficiently filled to the tip of the blowing port 26 of the blowhead 24, the sand blowing is stopped, and the blowhead 24 is separated from the molds 6, 8 and further retreated to the rear end position shown in FIG. The blowing ports 22 of the molds 6 and 8 are left with sand blown surfaces, that is, blowing port traces.

Next, by the operation of the cylinder 40 for lifting and lowering the gasssing head, the gashing head 46 is moved to the molds 6 and 8.
is lowered to a position facing the air inlet 22,
Therefore, the movable plate 54 and the pressing head 56 shown in FIGS. 2 and 3 are also moved to a position where the center line of the air inlet 22 and the pressing head 56 are aligned. In this way, the pressing head 56
There is an advantage that the drive mechanism of the gassing head 46 can be used when lowering the gasket.

Thereafter, the blow head 24 is moved forward again, and by pushing the back surface 72 of the gashing head 46, the gashing head 46 is guided by a guide member (not shown) and moved forward, as shown in FIG. The sealing member 70 closely contacts and contacts the periphery of the air inlet 22 . At this time, the movable plate 54
A portion of the guide pin 66, which is fixed to the press head 56, is fitted into the pin hole 68 shown in FIG.

In this state, pressurized air is introduced into the bellows 58 through the air supply/discharge hose 62 and the like. As shown in FIG. 4, based on the extension of the bellows 58, the movable plate 54 is moved (advanced) while being guided by the guide pin 66 that engages with the pin hole 68 until it comes into contact with the molds 6 and 8. Accordingly, the pair of pressing heads 56 are fitted into the blowing ports 22 of the molds 6 and 8 with high precision. This fitting dimension is
As mentioned above, the depth is slightly deeper than that of the blowhead 24.

By inserting the pressing head 56, the sand at the inlet hole is pressed and flattened by the pressing head 56, and at the same time, the core dimension in the direction parallel to the center line of the inlet 22 is accurately ensured. When shaping the inlet trace in this way, the sand in the vicinity is pushed slightly into the cavity 20 by the pressing head 56, so that the filling performance of the sand is also improved.

When the pressurized air in the bellows 58 is discharged after shaping the inlet trace by the pressing head 56, the bellows 58 returns to its original shape by its own restoring force, and the movable plate 54 separates and retreats from the molds 6 and 8. I am made to do so. At the same time, the pressing head 56 is also pulled back to the opening of the gassing head 46 and removed from the air inlet 22, allowing the next injection of curing gas. Since the pressing head 56 and the like are provided on the gassing head 46, the time required from forming the inlet trace to starting gas injection can be extremely short.

Thereafter, the gassing head 46 is moved to the seal member 7.
0, through the gas supply hose 48 shown in FIG.
A curing gas, such as the TEA gas, is supplied into the gassing head 46. The gas is the gas outlet 53
The core is blown into the cavity 20 through the blowing port 22 from the gap between the inner surface of the mold and the movable plate 54, and the core after the blowing hole trace has been shaped is hardened.

After the curing is completed, when the blow head 24 is moved back, the gashing head 46 is also moved back via the engagement member 74 fixed to the gashing head 46, and is separated from the molds 6,8. When the blow head 24 reaches its retraction limit, the gushing head 46 is raised to its raised position and the first
The state shown in the figure will be reached.

The hardened core is cut out by a conventional method, and the desired cores are successively molded in the same manner.

In the above explanation, the pressing head, which is movable relative to the gushing head, is driven by a bellows and fitted into the mold's blowing port, but instead of the bellows, it is also driven by the fluid pressure. A diaphragm, a cylinder, or the like, which is actuated by the actuator, may be used, and mechanical means such as a cam or a linkage mechanism may also be used.
It is desirable to select which one to adopt depending on the degree of pressing force required.

It goes without saying that the present invention can be implemented in various other ways without departing from the scope of the claims.

[Brief explanation of the drawing]

FIG. 1 is an overall view showing an example of a mold making apparatus which is an embodiment of the present invention. FIG. 2 is a partially sectional view showing an enlarged view of the main parts in FIG.
Figure 2 is a cross-sectional view. FIG. 4 is a partial sectional view corresponding to FIG. 2 showing the operating state when forming the blow hole trace. 6: Lower mold, 8: Upper mold, 14: Mold opening/closing cylinder,
20: Cavity, 22: Inlet (of mold), 2
4: Blow head, 39: Blow air supply hose,
46: Gassing head, 54: Movable plate,
56: Pressing head (pressing member), 58: Bellows.

Claims (1)

[Scope of Claims] 1. A mold having a cavity for molding a mold, a blowing port communicating with the cavity, a mold opening/closing device for opening and closing the mold, and sand having a sand blowing nozzle that can be brought into close contact with the blowing port. In a gas hardening type mold making device comprising a blowing device and a hardening gas supply device having a gashing head that can be brought into close contact with the gashing port, the hardening gas supply device may be fitted into the gas blowing port of the gashing head. The pressing member for flattening the mold surface inside the blowing hole is moved between an active position where the pressing member is inserted into the blowing hole and a retreat position where it is removed from the blowing hole with its gushing head in close contact with the blowing hole. A mold making device characterized in that it is attached via an actuator. 2. The mold making device according to claim 1, wherein the actuator is a bellows that is connected at one end to the gushing head and at the other end to the pressing member, and is expanded and contracted by supplying and discharging compressed air. .