JPH09314283A - Mold and method for coating seal agent to this mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the sticking-out of seal agent to a product forming part and the development of flash caused by shortage of spreading of the seal agent. SOLUTION: A width size (a) of a core print plane part 10 which has the relation of the plane at the angle to a mold joining direction and small set clearance size in the core print parts 5 of a core 4 forming a part of the mold joining surface 3a, is set to larger than a width size (b) of a standing-up position 11 which has a prescribed mechanism to the mold joining direction and large set clearance size. At the same time, the coating locus of the seal agent S at the core print plane part 10 is separated from the product forming part W as far as possible and set to the outer side from the coating locus at the standing-up part 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sand mold for casting and a method of applying a sealant to the sand mold, and particularly to a clearance portion formed between main molds and between mold matching surfaces of the main mold and the core. The present invention relates to a mold in which a viscous liquid sealant is interposed in a clearance portion thereof to prevent the molten metal from being inserted, and a method of applying the sealant to the mold.

[0002]

2. Description of the Related Art A main mold and a main mold constituting a sand mold for casting,
Alternatively, in order to prevent the molten metal from being inserted into a clearance portion formed between the mating surfaces of the main mold and the core, the clearance portion is conventionally sealed. As this sealing technique, it is general to set a set clearance dimension (gap) on the mold matching surface to be small enough not to allow the molten metal to enter (for example, 0.2 mm or less at the maximum), but it depends only on the clearance setting. This method is easy to implement and cost effective, but especially when the precision of the mold itself is low, such as in the case of a raw mold, the clearance dimension at the mold matching surface is small, so the mold matching portion locally abuts. As a result, a defect called so-called indentation, in which a part of the main mold collapses and falls, is frequently generated, which is not preferable.

For this reason, as another sealing technique for a mold, for example, as disclosed in Japanese Patent Laid-Open No. 4-356326, a concave groove is provided in the outer peripheral portion of the mold, and a gum-like self-shaped groove is formed in the concave groove. A seal which is filled with a hard sealant, or a seal made of a compressible material such as paper or pulp at the mold-matching portion between the core and the sand mold, as shown in JP-A-58-20348. In addition to the one in which a packing is interposed, a method of applying a viscous liquid sealing agent in a bead shape to a mold matching portion has been partially tried.

As a means for automating the application operation of the liquid sealant as described above, for example, a discharge gun is attached to the tip of an arm of an industrial robot and moved at a constant speed along a preset application locus. On the other hand, there has been proposed a system for supplying a fixed amount of a sealing agent contained in a tank to a discharge gun with a pump.

[0005]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention For example, the set clearance size at the mating surface of the mold molded by the high-pressure molding line of green sand used for casting of cast iron is set in consideration of the equipment accuracy at the time of mold matching, Generally, in the general plane portion (the surface perpendicular to the mold matching direction), as described above, 0 to 0.2.
While the value is relatively small, such as about mm, it is 0.3 for a so-called rising portion (face) having a predetermined gradient in the mold matching direction such as a skirting portion of a core or a portion having a complicated shape. It is set to a relatively large value of about 0.5 mm.

If a sealing agent is applied to such a mold in a bead shape and uniformly with the aim of the widthwise central portion of the mold matching surface by using the above-mentioned sealing robot, the set clearance size is inevitably increased. Since the crushing method of the sealant differs depending on the size, the sealant will not spread sufficiently in the part where the set clearance size is large, and conversely the sealant will spread too much in the part where the set clearance size is small. .

At the portion where the sealing agent is insufficiently spread, the clearance formed between the mating surfaces cannot be completely filled with the sealing agent, which causes the insertion of the flash into the clearance, and conversely In the portion where the over-spreading occurs, the sealing agent is squeezed out to the product area, resulting in lack of thickness of the cast product, which is not preferable.

The present invention has been made in view of the above problems, and inserts or lacks of a flash caused by an excess or deficiency of the spreading (crushing) of the sealant according to the size of the set clearance. An object of the present invention is to provide a mold and a method for applying a sealant to the mold so as to prevent the generation of meat.

[0009]

The invention according to claim 1 is characterized in that a viscous liquid sealant is interposed in the clearance portion formed between the main molds and between the mold mating surfaces of the main mold and the core. The clearance part is sealed,
This clearance part is a mold including a part where the set clearance size is partly large, and the width size of the part of the skirting part of the core forming the mold matching surface where the set clearance size is small. Is set to be larger than the width dimension of a portion having a large set clearance dimension.

According to a second aspect of the present invention, a portion of the invention according to the first aspect, in which the set clearance dimension is partially large, rises in the skirting portion having a predetermined gradient with respect to the mold matching direction. It is characterized by being a part.

The invention according to claim 3 relates to a mold including a part where a set clearance dimension is partially increased in a clearance part formed between the main molds and between the mold mating surfaces of the main mold and the core. When applying a viscous liquid sealant to the mating surface in a bead shape, apply the sealant to the outer part away from the product shape part in the part where the set clearance dimension is small in the skirting part of the core that becomes the mold matching surface. On the other hand, it is characterized in that the sealant is applied to the inner portion close to the product shape portion at the portion where the set clearance dimension is large.

According to a fourth aspect of the present invention, in the third aspect of the invention, a width dimension of a portion of the skirting board portion of the core forming the mold matching surface having a small set clearance dimension is set. It is characterized in that it is set to be larger than the width dimension of a portion having a large clearance dimension.

According to a fifth aspect of the invention, in the third or fourth aspect of the invention, the sealing agent is quantitatively supplied to the discharge gun supported at the tip of the robot arm of the sealing robot, while the sealing robot is autonomous. The operation is to move the discharge gun along a preset coating locus at a constant speed to perform the sealing agent coating operation.

Therefore, according to the first and second aspects of the invention, among the skirting parts of the core forming a part of the mold matching surface, for example, in a plane perpendicular to the mold matching direction. A width dimension of a portion having a small set clearance dimension as typified is set to be larger than a width dimension of a portion having a large set clearance dimension typified by a so-called rising portion having a predetermined gradient with respect to the mold matching direction. Therefore, for example, if it is assumed that the sealant is applied aiming at the widthwise center of the skirting board that will be the mold matching surface, the outside where the set clearance dimension is small is far from the product shape part. The sealant is applied to the portion, and conversely, the sealant is applied to the inner portion relatively close to the product shape portion in the portion where the set clearance dimension is large.

As a result, even if the area where the set clearance dimension is small and the area where the set clearance dimension is large inevitably differ in how the sealant is crushed during mold matching, the product will be manufactured regardless of the size of the set clearance dimension. It is possible to prevent the sealing agent from spreading to the boundary position with the shaped portion, and prevent the sealing agent from squeezing out toward the shaped portion of the product and insufficient expansion of the sealing agent that causes flashing.

The above is exactly the same for the invention according to claim 3 in which the application position of the sealing agent is positively changed according to the set clearance size.
In particular, as in the invention described in claim 4, when the width dimension of the skirting board is changed in accordance with the size of the set clearance dimension, the application position of the sealant is also positively changed, The above-mentioned effects of preventing the protrusion and the occurrence of flashing are more remarkable.

Further, in the invention according to claim 5, when the sealing robot is used for applying the sealing agent,
The application position of the sealing agent can be changed according to the size of the set clearance dimension as described above by simply discharging the sealing agent by a constant amount while moving the discharge gun at a constant speed.

[0018]

According to the first and second aspects of the present invention, the width dimension of a portion having a small set clearance dimension in the skirting part of the core which is a part of the mold matching surface has a large set clearance dimension. Since it is set larger than the width dimension of the part, if it is assumed that the sealant is applied aiming at the center part of the above width dimension, the part with a small set clearance dimension is relatively separated from the product shape part. It is possible to apply the sealant to the outer portion. As a result, the sealant can be expanded to the boundary position with the product shape section regardless of the size of the set clearance dimension, and the product lacks due to the sealant protruding to the product shape section side. By preventing the occurrence of flash and flash, casting quality is greatly improved.

Further, since the size can be used as it is without changing the set clearance size in the conventional mold matching portion, workability is not particularly deteriorated when the core is set.

According to the third aspect of the present invention, the sealant is applied to the outer portion relatively distant from the product shape portion in the portion where the set clearance dimension is small. The same effect as the invention described above can be obtained, and particularly when the width dimension of the skirting portion is changed according to the size of the set clearance dimension as in the invention described in claim 4, the above effect becomes more remarkable. Become.

According to the fifth aspect of the present invention, when the sealing agent application work is performed by the sealing robot, the set clearance is set as described above by merely discharging a fixed amount of the sealing agent while moving the discharging gun at a constant speed. The application position of the sealant can be changed according to the size.
In addition to the same effects as the invention according to claim 3 or 4,
There is an advantage that the coating position control and speed control on the sealing robot side can be simplified.

[0022]

1 to 3 are views showing a typical embodiment of the present invention, which is a mold for casting a hollow casting product W as shown in FIGS. The method of applying the sealant to the mold is shown.

The mold 1 is composed of an upper mold 2 and a lower mold 3 which are molded with green sand, and a core 4 which is also molded with green sand. The skirting part 5 is integrally formed to project. Then, by matching the skirting board portion 5 of the core 4 with the skirting board receiving portions 6 and 7 on the upper and lower molds 2 and 3 at the time of matching the upper and lower molds 2 and 3, a core is provided between the upper and lower molds 2 and 3. 4 is sandwiched and positioned and fixed, and at the same time, a space 8 serving as a product-shaped portion W is formed between the upper and lower molds 2 and 3.

Mold matching surfaces 2a, 3a of the upper and lower molds 2, 3
A clearance portion formed by butting each other, and a clearance portion formed by butting the skirting board receiving portions 6, 7 of the upper and lower molds 2, 3 and the skirting board portion 5 of the core 4 with each other. 1, a viscous liquid sealant S in a closed loop is applied to the entire peripheral edge of the product shape portion W so as to surround the product shape portion W to seal the clearance portion. There is. The viscous sealant S is a known one in which a refractory such as calcium carbonate and an oil component are kneaded, and an emulsifier or the like is added as necessary to adjust the viscosity.

More specifically, as shown in FIGS. 4 (A) and 4 (B), a general flat surface portion of the mold matching surfaces 2a and 3a, which is the clearance portion, which is perpendicular to the mold matching direction. 9 and the skirting board flat portion 10, the set clearance dimension C ₂ is set to about 0.2 mm, whereas the rising portion 11 of the skirting board portion 5 having a predetermined gradient in the mold matching direction Set clearance dimension C ₁
Is set to about 0.5 mm, which is larger than the general flat surface portion 9 and the baseboard flat surface portion 10 as in the conventional case, but they are abutted against each other while forming a part of the mating surfaces 2a and 3a. The width dimension a of the different skirting board receiving portions 6 and 7 and the skirting board flat portion 10 of the skirting board portion 5 is formed wider than the width dimension b of the rising portion 11.

The sealing agent S is uniformly applied in a bead shape on the respective mold-matching surfaces 2a and 3a by a predetermined discharge gun prior to the mold matching. However, as shown in FIG. 1, the application locus position is applied so that it is an outer position as far as possible from the product shape portion W on the general plane portion 9, while a baseboard having a predetermined gradient. The rising portion 11 of the portion 5 is applied to the inner portion as close as possible to the product shape portion W, and further, the wide baseboard 10 and the baseboard receiving portions 6 and 7 are applied with the sealant application trace position from the product shape portion W. It is applied to a position slightly outside the central portion of the width dimension so that the distance to is equal to that of the general flat surface portion 9.

According to the mold structure as described above, when the sealing agent S is applied to the respective mold matching surfaces 2a and 3a as described above and the molds are matched with each other, the general planes of the mold matching surfaces 2a and 3a are as described above. parts 9,9 clearance portion formed by each other, and the clearance portion formed by the skirting flat portion 10 and the skirting receiving portions 6 and 7, the setting as shown in FIG. 4 (B) clearance dimension C ₂ Since the sealant S is squeezed into a relatively wide area due to a small value, the rising clearance 11 of the skirting part 5 has a large set clearance dimension C ₁ as shown in FIG. The degree to which the sealant S is crushed becomes relatively small. On the other hand, as described above, in the portion where the degree of crushing of the sealant S is large and the portion where the degree of crushing is small, the application locus position of the sealant S itself is offset by a predetermined amount e, and the sealant S is crushed. In a portion having a small degree, that is, a portion corresponding to the rising portion 11 of the skirting portion 5, the application position of the sealant S is set to an inner portion relatively closer to the product shape portion W than other portions.

Therefore, regardless of the degree to which the sealant S is crushed, the edge portion of the crushed sealant S spreads to the boundary with the product shape portion W without excess or deficiency, and the sealant S spreads too much. It does not enter the product shape portion W, nor does the spreading of the sealing agent S become insufficient, and the occurrence of flashing on the mold matching surfaces 2a and 3a side does not occur.

FIG. 8 is a schematic plan view of the entire molding line for molding the sand mold 1 described above.

As shown in FIG. 8, in the lower mold forming step S1, the lower mold 3 which is a part of the mold 1 described above is molded by a known molding method with its mold matching surface facing downward, While being transported by a transporting means such as the above, it is turned upside down by a reversing machine in the reversing step S2 of the next step and then carried into the first sealing step S3. The lower mold 3 is a so-called framed type having a metal molding frame 13 as shown in FIG.

In the above-mentioned first sealing step S3, there is a sealant applying device 14 as shown in FIG. 9, and the lower die 3 has a mating surface with the skirting part 5 of the core 4 which is set in a later step. The sealant S is evenly applied in a bead shape to the portion to be formed, that is, the skirting board receiving portion 7 on the lower die 3 side.

As shown in FIG. 9, the sealant applicator 14 in the first sealing step S3 includes a joint type sealing robot 15 and a discharge gun (sealing) attached to the tip of the robot arm 16 and having a discharge amount control function. In addition to the (gun) 17, a fixed amount supply device 18 for the sealing material S, a robot control panel 19, a pump control panel 20, and the like are provided. The fixed amount supply device 18 for the sealing material S is a tank in which the sealing agent S is stored. 21 and a pump unit 22 and the like set on the upper surface of the tank 21. Since the locus data for applying the sealant S is stored and set in advance in the storage unit of the robot control panel 19 by teaching, the sealing robot 15 discharges by performing the playback operation of the sealing robot 15. While moving the gun 17 along the trajectory data, the sealing agent S is evenly applied in a bead shape to the portion of the lower mold 3 to be the mating surface with the core 4 with a thickness of 1 to 5 mm as described above. It will be.

In the first sealing step S3 of FIG. 8, the lower mold 3 which has been coated with the sealing agent S is transferred to the carriage of another conveyor in the transfer step S4, and then the core setting step S is performed.
5 is transported.

In the above-mentioned core setting step S5, as shown in FIG. 10, a sand core 4 molded in another core molding step on the lower mold 3 to which the sealant S has been applied in advance. Is positioned and fixed. Then, by interposing the sealing agent S on the mating surface between the lower mold 3 and the core 4, the gap between the mating surfaces is filled. And the lower mold 3 with the core 4 set
Is conveyed to the second sealing step S6.

In the second sealing step S6, as shown in FIG. 10, there is a sealant applying device 14 which is substantially the same as that of the first sealing step S3.
The sealing robot 15 constituting the sealant applicator 14 of No. 6 is a part of the lower mold 3 combined with the core 4 that is to be a mold matching surface with the upper mold 2 set in a later step, that is, the inside. The sealing agent S is beaded on the skirting board 10 of the skirting board 5 which should be the mating surface of the child 4 and the upper die 2 and the general plane 9 which is the mating surface of the lower die 3 and the upper die 2. Apply evenly on. The lower mold 3 thus coated with the sealant S
Is conveyed to the mold matching step S7.

On the other hand, in the upper mold making step S11, in parallel with the lower mold making step of the lower mold making step S1, the upper mold 2 having the casting frame 23 shown in FIG. After being molded by the molding method, it is conveyed to the position closest to the mold matching step S7 by a conveying means such as a conveyor in the same posture and is on standby.

Then, when the lower mold 3 combined with the core 4 as described above is carried into the mold matching step S7, the upper mold 2 is positioned and placed on the lower mold 3 so as to be superposed thereon. To be done. As a result, the sealing agent S previously applied to the mating surface between the core 4 and the upper mold 2 and the mating surface between the lower mold 3 and the upper mold 2 is interposed to fill the gaps between these mating surfaces.

From the above, the lower die 3, the core 4 and the upper die 2
Are combined with each other to complete the mold 1, and the mold 1 is finally transported to a pouring process which is a post process.

[Brief description of drawings]

FIG. 1 is an explanatory plan view of a mold showing a typical embodiment of the present invention.

FIG. 2 is a vertical sectional view of FIG.

3 is a cross-sectional view taken along the line CC of FIG.

FIG. 4 is an explanatory view showing how the sealant spreads according to the size of the set clearance dimension in the mold shown in FIGS.

5 is a plan view of a casting product cast by the mold of FIG. 1. FIG.

6 is a half sectional view of the casting product of FIG. 5 as seen from the front.

FIG. 7 is a half cross-sectional view of the casting product of FIG. 5 viewed from the right side.

FIG. 8 is an explanatory plan view of a high-pressure molding line for molding the mold of the present invention.

9 is an explanatory view of a first sealing step shown in FIG.

10 is an explanatory view of a second sealing step shown in FIG.

FIG. 11 is an explanatory diagram of a mold matching process shown in FIG. 8.

[Explanation of symbols]

1 ... Mold 2 ... Upper mold (main mold) 2a ... Mold matching surface 3 ... Lower mold (main mold) 3a ... Mold matching surface 4 ... Core 5 ... Baseboard part 6, 7 ... Baseboard receiving part 9 ... General plane part 10 ... skirting flat portion 11 ... rising portion 16 ... sealing robot 17 ... dispensing gun C _1, C ₂ ... set clearance dimension S ... sealant W ... product shape portion (cast products)

Claims (5)

[Claims] 1. The clearance portion is sealed by interposing a viscous liquid sealant in the clearance portion formed between the mold halves and between the mold matching surfaces of the main mold and the core. A mold including a portion where the set clearance dimension is partially increased, wherein the width dimension of the portion of the skirting board of the core forming the mold matching surface where the set clearance dimension is small is set to the set clearance dimension. A mold characterized by being set to be larger than the width dimension of a large part. 2. The part where the set clearance dimension is partly large is a rising part of the skirting part having a predetermined gradient with respect to the mold matching direction.
The template described. 3. A mold including a part where a set clearance dimension is partially increased in a clearance part formed between mold halves between main molds and between mold matching surfaces of the main mold and the core.
When applying a viscous liquid sealant to the mating surface in the form of beads, the sealant is applied to the outside of the product shape part at the part where the set clearance dimension is small in the skirting part of the core that becomes the mold matching surface. On the other hand, a method of applying a sealing agent to a mold, characterized in that the sealing agent is applied to an inner portion close to the product shape portion at a site where the set clearance dimension is large. 4. The width dimension of a portion having a small set clearance dimension in the skirting portion of the core forming the mold matching surface is set to be larger than the width dimension of a portion having a large set clearance dimension. The method for applying a sealing agent to a mold according to claim 3, 5. A sealing agent is supplied in a fixed amount to a discharge gun supported at the tip of a robot arm of a sealing robot, while the discharge gun is moved at a constant speed along a preset coating locus by the autonomous operation of the sealing robot. The method for applying a sealing agent to a mold according to claim 3 or 4, wherein a sealing agent application operation is performed.