JP5031700B2 - Sand mold manufacturing method and jig - Google Patents

Description

  The present invention relates to a method for producing a sand mold and a jig used in the method. In particular, the present invention relates to a method of manufacturing a sand mold with a hot water insulation sleeve whose upper end is closed, and a treatment for fixing the hot water insulation sleeve so as not to be detached from the casting model during the production process. It relates to ingredients.

  A mold is required to make a casting. Also, a casting model in the shape of a casting is required to make a mold. To make a mold using a casting model, place the casting model in a metal frame, pour casting sand into the metal frame, wrap the model in sand, squeeze the sand to create a sand mold, and then remove the casting model from the sand mold. Go away, and leave this as a mold, leaving a mold cavity in the shape of a casting.

  Usually, a hot water insulation sleeve is attached to the mold. The hot-water insulation sleeve is attached to prevent the molten metal from being cooled and contracted to form shrinkage when a casting is made in the mold cavity of the mold. The hot water insulation sleeve is attached above and / or to the side of the mold cavity, and the interior of the hot water insulation sleeve communicates with the mold cavity. The action of the hot-water insulation sleeve is to accommodate molten metal during casting and maintain the contained metal in a molten state for as long as possible so that the molten metal can be replenished to the casting side.

  The mold is automatically made by a molding machine. In the molding machine, first, the hot water insulation sleeve is fixed to the casting model, the casting sand is dropped around them in the metal frame, and the dropped sand is clamped around the hot water insulation sleeve and the casting model to form the sand mold. create. Moreover, sand mold may be made by blowing casting sand with a strong pressure. At this time, the hot water insulation sleeve is sometimes put on the cast model, but sometimes the whole is rotated by 90 degrees from this state, and the hot water insulation sleeve is connected to the side of the cast model, Sometimes it is placed on its side. This is to drop the foundry sand evenly above and below the cast model. Furthermore, in order to pack sand without gaps, the whole may be vibrated. As described above, the hot water insulation sleeve is subjected to various forces in the molding machine, and is thus easily moved from a predetermined position.

  Therefore, in order to efficiently create a sand mold by a molding machine, it is necessary to firmly fix the hot water insulation sleeve to the casting model. However, this fixation must be easy to separate after sand casting. This is because, after making the sand mold, the casting model is removed from the sand mold, but the hot-water insulation sleeve must remain in the sand mold. Thus, the hot-water insulation sleeve needs to be firmly fixed to the mold model and must be easily separated from the casting model. For this reason, various methods have been devised for fixing the hot water insulation sleeve to the cast model.

  As described above, the hot-water insulation sleeve must supply the molten metal contained therein to the casting, so the lower end must be open and communicate with the mold cavity where the casting is made. . On the other hand, there are a case where the upper end of the hot-water insulation sleeve is fully closed and a case where a hole is made there. Further, there are cases where the lower end of the hot-water insulation sleeve has a large opening with the same size as the inner diameter of the cylinder, and a case where the opening is narrower than the inner diameter of the cylinder.

  Japanese Patent Laid-Open No. 3-142037 proposes a method of fixing a hot water insulation sleeve to a cast model when using a hot water insulation sleeve having a large opening at the lower end and a hole at the upper end. . The method is a method using a jig Z as shown in FIG. However, in this proposal, there is a gap that can slide between the hole opened at the upper end of the hot water insulation sleeve and the upper portion P of the jig Z. If this is received, the hot water insulation sleeve floats along the upper part P of the jig Z and is separated from the casting model, so this fixing method is not satisfactory.

  Therefore, at the site, a rubber band is wound around a part of the upper part P of the jig Z to fill a gap between the hole provided at the upper end of the hot water insulation sleeve and the upper part P, and the hot water is generated by sliding friction of the rubber band. An attempt was made to fix the heat insulation sleeve to the jig Z. However, it is difficult to wind the rubber band around the upper part P to a thickness that just fills the gap. If the thickness is too large, it becomes difficult to insert the upper part P into the hole, and conversely if the thickness is too small. I can't close the gap. In addition, the rubber band has poor durability, so it needs to be replaced frequently, so that this attempt has a problem that it is not suitable for practical use.

  In general, when a hot water insulation sleeve having a hole at the upper end is used, sand is likely to enter the hot water insulation sleeve through the hole when making a sand mold in the molding machine. Since the sand that has entered falls into the mold cavity where the casting is made, or enters the casting with the flow of molten metal, the casting causes a sand bite defect. For this reason, it is preferable to use a hot water insulation sleeve whose upper end is fully closed.

However, it is generally difficult to secure the hot-water insulation sleeve whose upper end is fully closed so as not to be separated from the jig by being firmly fixed to the jig. Until now, as shown in FIG. 2, a rod-shaped body 1 having a small-diameter portion 2 at the top and a donut-shaped rubber ring C fixed to the tip of the small-diameter portion 2 has been used as a jig. In this jig, the small-diameter portion 2 is inserted into a recess E provided on the inner surface of the upper end of the hot water insulation sleeve D, and the hot water insulation sleeve D falls off the jig by bringing the ring C into close contact with the wall surface of the depression E. Came not to come. However, the ring C was not satisfactory because the locking force was uneven and the durability was poor, so it had to be replaced frequently. Therefore, the emergence of alternative methods has been desired.
JP-A-3-142037

  This invention was born in response to the above-mentioned demand. That is, the present invention uses a hot water insulation sleeve closed at the upper end, and is intended to make it easy to make a sand mold with a hot water insulation sleeve by using a molding machine after fixing it to a casting model. .

  This inventor tried to achieve the above-mentioned object by improving a jig for fixing the hot-water insulating sleeve to the cast model.

  The inventor considered that a spring wire was used instead of the rubber ring and that the hot-water insulating sleeve was not pulled out of the jig by the elasticity of the spring wire. As a conventional jig, a rod-shaped body with a small-diameter portion attached to the upper end is used as a main body, a plurality of spring wires extending in the direction of the rod axis are fixed to the side surface of the small-diameter portion, and the spring wire is attached around the rod-shaped body. Arranged at equal intervals in the direction and made a structure in which the central part of each spring wire protrudes outwardly with elasticity. The present inventors have found that the above-mentioned demand can be satisfied when the hot water insulation sleeve is fixed to the cast model using the jig having this structure.

  In the jig having the above structure, the spring wire extends in the direction of the rod axis and protrudes outward. Therefore, by adjusting the elastic force protruding outward of the spring wire, the protrusion of the spring wire is suppressed and the jig is pressed. Can be easily inserted into the hot-water insulation sleeve, and the hot-water insulation sleeve can be held by the spring wire so that the jig can be easily removed from the hot-water insulation sleeve. The elasticity of the spring wire protruding outward can be easily adjusted by changing the material, shape, size and number of spring wires. On top of that, unlike the rubber ring, the spring wire has no uneven locking force and has sufficient durability, so it does not need to be replaced frequently. Based on such confirmation, the present invention has been completed.

  The above-described spring wire need not be a wire, and may be a belt-like one. The spring wire does not need to be made of metal, particularly steel, and can be made of a hard synthetic resin having a high elasticity such as polycarbonate. In addition, the spring wires may be formed separately one by one in the direction of the rod axis. Alternatively, two spring wires that are diametrically opposed around the rod axis may be configured as a single wire. it can. Including such various cases, the above-described spring wire will be referred to as a strip.

  In one aspect, the present invention provides a jig for fixing a hot water insulation sleeve to a cast model when a sand mold is manufactured. The jig has a small-diameter portion at one end of the rod-shaped body, and a plurality of strips extending in the axial direction of the rod-shaped body are fixed on the side surface of the small-diameter portion at equal intervals in the circumferential direction of the rod-shaped body. Is protruded outward elastically, and a fixing portion to the cast model is provided at the other end of the rod-shaped body.

  In another aspect, the present invention provides a method for producing a sand mold with a hot water insulation sleeve using the above-described jig. In this case, the hot-water insulating sleeve used is closed at the upper end, and a recess is formed on the inner surface of the closed end. The recess is for accommodating the small diameter portion of the jig together with the strip attached thereto. The accommodated strip acts to press the wall surface of the dent with elasticity to fix the hot water insulation sleeve to the jig.

  In this way, the sand mold manufacturing method provided by the present invention is provided with a small-diameter portion at one end of the rod-shaped body, and a plurality of surfaces extending in the axial direction of the rod-shaped body with the same interval in the circumferential direction of the rod-shaped body on the side surface of the small-diameter portion Fix the strips and use each jig to elastically project outwards as a jig, fix the other end of the rod-shaped body to the cast model, stand the jig on the cast model, and keep the hot water warm A recess is provided on the inner surface of the closed end of the sleeve, the hot water insulation sleeve is placed on the jig, and the small diameter portion of the jig enters the depression of the hot water insulation sleeve together with the strip, and the strip is depressed. The hot water insulation sleeve is fixed to the jig by pressing the wall of the mold, and in this state in the molding machine, the casting model and the hot water insulation sleeve are filled with casting sand to create a sand mold, and then the sand mold is cured. The tool is removed together with the cast model to form a sand mold.

  In the jig for fixing the hot-water insulation sleeve according to the present invention, since the small-diameter portion is provided at one end of the rod-like body and the fixing portion to the cast model is provided at the other end, the fixture can be easily attached to the cast model. Can be attached. In addition, a plurality of strips extending in the axial direction of the rod-shaped body are fixed to the side surface of the small diameter portion, and each strip is elastically projected outward. It is possible to easily cover the hot water insulation sleeve.

  In this case, as the hot-water insulation sleeve, one end is closed and a hollow is provided on the inner surface of the closed wall, so that the small-diameter portion of the jig can be accommodated together with the strip in the hollow. Since the accommodated strips are fixed at equal intervals in the circumferential direction of the rod-shaped body, the small-diameter portion is held at the center in the recess, and the jig is removed from the hot water insulation sleeve by the pressing force of the strips. Hold so that it does not escape. Thus, the hot water insulation sleeve is firmly held by the jig by the elasticity of the strip. Therefore, a sand mold with a hot water insulation sleeve can be easily made by a molding machine.

  When the cast model is removed after the sand mold is made, the jig is fixed to the cast model, while the hot water insulation sleeve is only held by the elasticity of the strip, so the jig is pressed. It is separated from the hot water insulation sleeve and extracted from the sand mold together with the casting model. Thus, this jig facilitates making a sand mold with a hot water insulation sleeve in the molding machine.

  Moreover, according to the sand mold manufacturing method of the present invention, since the above-described jig is used, the other end of the rod-shaped body can be easily fixed to the cast model. Then, a jig will be in the state which made the rod-shaped body stand upright on the casting model. This jig has a structure in which a small diameter portion is provided at the upper end, and a plurality of strips extending in the axial direction of the rod-shaped body are fixed to the side surface of the small diameter portion. Therefore, the jig can be easily covered with the hot water insulation sleeve.

  As the hot-water insulation sleeve, one end is closed and a hollow is provided on the inner surface of the closed end, so when the hot-water insulation sleeve is put on a jig, the small diameter portion is accommodated in the depression. Since the strip fixed to the side surface of the small diameter portion extends in the axial direction of the rod-shaped body, the strip can be easily accommodated in the recess. Then, since the strip is protruded outward by the elastic force, the side wall of the depression is pressed by the elastic force, and thereby the hot water insulating sleeve is fixed to the jig. Since the plurality of strips are fixed at equal intervals in the circumferential direction of the rod-shaped body, the rod-shaped body is held at the center of the recess. Thus, the hot water insulation sleeve is firmly fixed to the jig. Therefore, even if the casting sand is roughly dropped or sprayed around the hot water insulation sleeve and the cast model, the hot water insulation sleeve does not move away from the cast model. Therefore, a sand mold with a hot water insulation sleeve can be easily made by a molding machine.

The jig is mechanically fixed to the cast model with screws, for example, and on the other hand, it is only locked to the hot water insulation sleeve by the elasticity of the strip, so that a sand mold is made. After that, when the feeder model is removed from the sand mold, the jig can be easily removed from the sand mold together with the cast model. In this way, a sand mold with a hot water insulation sleeve can be easily made.
The present invention provides such an effect.

  An embodiment of the present invention will be described with reference to the drawings as follows. In that case, FIG. 3 is a side view of the jig according to the present invention. FIG. 4 is an enlarged view of a part of the jig shown in FIG. FIG. 5 is a side view of the strip used in the present invention. FIG. 6 is a partially cutaway side view of the upper end of another jig according to the present invention. FIG. 7 is a side view of another strip used in the jig according to the present invention. FIG. 8 is a cross-sectional view of a hot water insulation sleeve fixed to a jig by the method of the present invention. FIG. 9 is a perspective view of still another jig according to the present invention.

  As shown in FIG. 3, the jig according to the present invention is provided with a small-diameter portion 2 at the upper end of the rod-shaped body 1, and the strips 3, 3 extending in the axial direction of the rod-shaped body 1 are fixed to the side surfaces of the small-diameter portion 2. The strips 3 and 3 are elastically projected outward, and a screw 4 is provided at the lower end. The strips 3 and 3 are attached at equal intervals in the circumferential direction of the rod-like body 1. The screw 4 is a fixing part for fixing the rod-shaped body 1 to the casting model.

  As shown in FIG. 4, each strip 3 is formed of a strip-shaped peeler and is curved in a generally U shape in the longitudinal direction, and in close contact with the inner surface of the depression of the hot water insulation sleeve in the width direction. It is curved in a slightly arc shape so that it can be made. The upper end 32 and the lower end 33 are fixed to the side surface of the small-diameter portion 2 by, for example, welding or adhesion so that the strips 3 and 3 have a central shape 31 protruding outward. However, the lower end 33 of each strip 3 may be in a state in which it can move freely only by being close to the side surface of the small diameter portion 2.

  FIG. 5 shows other strips 3 and 3 that can be used in the jig according to the present invention. The strips 3 and 3 shown in FIG. 5 are the same as those shown in FIGS. 3 and 4 in that the strips 3 and 3 are curved in the shape of a dogleg in the longitudinal direction. Is different in that it is circular. Further, the strips 3 and 3 in FIG. 5 are different from those shown in FIGS. 3 and 4 in that both the upper end 32 and the lower end 33 are bent inward.

  The strip 3 shown in FIG. 5 is fixed to the small-diameter portion 2 indicated by a one-dot chain line as shown. That is, the strip 3 is fixed by welding or adhesion in a hole having an upper end 32 formed in the side surface of the small diameter portion 2, so that the central portion 31 protrudes outward most. The lower end 33 of the strip 3 is pushed into the hole 22 drilled in the side surface of the small-diameter portion 2 so that it can advance and retreat within the hole 22. In this way, the strip 3 is elastically protruded from the central portion 31 and is easily moved inward.

  FIG. 6 is a partially cutaway side view of the upper part of another jig according to the present invention. The strips 3 and 3 in FIG. 6 are integrally fixed to an annular ring 5 whose upper end circumscribes the side surface of the small diameter portion 2. The annular ring 5 is securely fixed to the small-diameter portion 2 at an appropriate position by forming the small-diameter portion 2 in a truncated cone shape having a diameter that decreases toward the tip. In this way, the upper ends of the strips 3 are fixed to the small-diameter portion 2 by the annular ring 5 and are bent in the shape of a dogleg in the longitudinal direction so that the central portion 31 protrudes most outward. The lower end 33 of each strip 3 is bent inward and is inserted into the hole 22 formed in the side surface of the small diameter portion 2 in the same manner as the strip 3 shown in FIG. It is made free.

  The strip 3 shown in FIG. 7 is peculiar in that it is configured in a shape in which two strips are connected. That is, the strip 3 is formed in a shape in which two strips that are diametrically opposed around the small-diameter portion 2 indicated by a one-dot chain line are connected at the upper end. In other words, a single steel wire is used, bent in a substantially U shape in the longitudinal direction, the U-shaped central piece 34 straddles the upper end of the small diameter portion 2, and both end pieces on the side surface of the small diameter portion 2. The two strips 3 and 3 are formed by being bent along the diametrically opposed portions and bent so as to be strips.

  Each of the strips 3 and 3 is fixed to the small diameter portion as shown in FIG. In FIG. 7, the small-diameter portion 2 is indicated by a one-dot chain line. In this case, the strips 3 and 3 are fixed to the small-diameter portion 2 by fitting a U-shaped central piece 34 into a groove 21 formed in the tip surface of the small-diameter portion 2. Further, the lower ends of the strips 3 and 3 are bent inward and inserted into holes 22 formed in the side surface of the small diameter portion 2 as in the strips shown in FIGS. .

  Each strip 3, 3 is made of a highly elastic material, extends in the axial direction of the small diameter portion 2, is curved in a longitudinal shape, and the central portion 31 protrudes outward most. Therefore, when the jig is inserted into the sleeve by bending the central portion 31 inward, each strip 3 presses the inner wall surface of the sleeve with a strong force. It cannot be easily escaped from. In particular, when the lower ends of the strips 3 are fixed without being fixed, it is easy to give an appropriate balance between the ease of insertion and the difficulty of escape.

  This jig is fixed on the casting model by screwing the screw 4 shown in FIG. 3 into the casting model X. Then, the jig is fixed on the casting model in a state where the rod-like body 1 is erected with the small diameter portion 2 first. For this reason, this jig can be easily covered with the hot water insulation sleeve.

  FIG. 8 shows a state in which the jig is covered with a hot water insulation sleeve. The hot water insulation sleeve D has the same structure as that shown in FIG. 2, and has a recess E on the inner surface of the closed end. In this recess E, the strip 3 of the jig according to the present invention is bent and the small diameter portion 2 enters. In this state, the protruding portion of the strip 3 presses the wall surface of the depression E with elasticity. For this reason, the hot water insulation sleeve D is firmly held by the jig, and the hot water insulation sleeve D is not easily detached from the jig.

  For this reason, in the state shown in FIG. 8, this is rotated by 90 degrees in the direction of arrow L so that the hot water insulation sleeve D is tilted sideways, and the hot water insulation sleeve D and the casting model X are surrounded. Even if the foundry sand is dropped and damped, the hot water insulating sleeve D does not move away from the cast model X. Further, the foundry sand does not enter the hot water insulation sleeve D. Therefore, according to the method of the present invention, a sand mold can be easily and reliably made by a molding machine.

  In this way, after the sand mold is made, when the cast model is removed from the sand mold, the jig is fixed to the cast model with screws, etc., so that the jig is removed from the sand mold together with the cast model, and on the other hand, the hot water insulation sleeve On the other hand, since it is only fixed by the pressing force due to the elasticity of the strip, the hot water insulation sleeve remains in the sand mold. Therefore, a sand mold provided with a hot water insulation sleeve is obtained. Thus, according to the method of the present invention, it is possible to easily make a sand mold with a hot water insulation sleeve by a molding machine.

  Although FIG. 8 shows a jig provided with two strips, the number of strips can be further increased since the two strips are the minimum. FIG. 9 shows a jig according to the present invention in which four strips 3 are attached. The strip 3 of FIG. 9 is made of one steel wire by connecting two strips that are diametrically opposed to each other as in the strip 3 of FIG. The steel wire is fitted into a groove 21 that has a center side cut into the top surface of the small diameter portion 2 and is perpendicular to the top surface. Further, the lower end of each strip 3 is bent inward and inserted into a through hole provided in the small diameter portion 2.

It is sectional drawing which showed the conventional method which fixes a feeder hot-water insulation sleeve to a casting model. It is sectional drawing which showed the other conventional method which fixes a feeder hot-water insulation sleeve to a casting model. It is a side view of the jig concerning this invention. FIG. 4 is a partially enlarged view of the jig shown in FIG. 3. It is a side view of the strip used in this invention. It is a partially notched side view of the upper end part of the other jig | tool which concerns on this invention. It is a side view of the other strip used for the jig | tool which concerns on this invention. It is sectional drawing of the hot water insulation sleeve fixed to the jig | tool by this invention method. It is a perspective view of another jig concerning this invention.

Explanation of symbols

1 Rod-shaped body 2 Small diameter part 3 Strip 4 Fixed part (screw)
5 ring 21 groove 22 hole 31 central portion 32 upper end 33 lower end 34 central piece

Claims (4)

A small-diameter portion is provided at one end of the rod-shaped body , a groove is formed on the tip surface of the small-diameter portion, and a central piece of an elastic strip bent in a U-shape is placed in the groove and positioned on both sides of the central piece. The two pieces are suspended along the side surface of the small diameter portion, the lower end is inserted into the hole formed in the side surface of the small diameter portion, the strip is fixed to the small diameter portion, and each strip is elastically projected outward. The jig is used as a jig, the other end of the rod-shaped body is fixed to the casting model, the jig is erected on the casting model, and a depression is provided on the inner surface of the closed end of the hot water insulation sleeve to keep the hot water insulation. Cover the sleeve with the above-mentioned jig, let the small diameter part of the jig enter the recess of the hot water insulation sleeve together with the strip, and the strip presses the wall surface of the depression to fix the hot water insulation sleeve to the jig, In this state in the molding machine, make a sand mold by filling the casting model and the hot water insulation sleeve around the casting sand, and then cast the jig from the sand mold. Drained off together with the mold, characterized in that the sand molds, the production method of the sand molds with feeder insulation sleeve. A small diameter portion is provided at one end of the rod-shaped body, a plurality of elastic strips extending in the axial direction of the rod-shaped body are arranged on the side surface of the small diameter portion at equal intervals in the circumferential direction of the rod-shaped body, and the upper end of each strip is Fix to the ring that circumscribes the side of the small-diameter part, and insert the lower end of each strip into the hole drilled in the side of the small-diameter part to fix each strip to the small-diameter part, and elastically remove each strip The jig projecting in the direction is used as a jig, the other end of the rod-shaped body is fixed to the casting model, the jig is erected on the casting model, and a recess is provided on the inner surface of the closed end of the hot water insulation sleeve. The hot water insulation sleeve is put on the above jig, the small diameter part of the jig is moved into the depression of the insulation hot water sleeve together with the strip, and the strip presses against the wall surface of the depression to fix the hot water insulation sleeve to the jig. In this state in the molding machine, fill the foundry sand and the hot water insulation sleeve with casting sand to make a sand mold. Rear sand mold from the jig the drained off together with the casting model, characterized by the sand molds, the production method of the feeder warmth sleeved sand molds. This jig is used to fix the hot water insulation sleeve to the cast model. A small-diameter part is provided at one end of the rod-shaped body, a groove is formed on the tip of the small-diameter part, and the groove is bent in a U-shape. Put the central piece of the elastic strip, hang the two pieces located on both sides of the central piece along the side of the small diameter part, and insert the bottom end into the hole drilled in the side of the small diameter part. Fixing jig for hot water insulation sleeve, which is fixed to a small diameter part, each strip is elastically projected outward, and a fixing part to a cast model is provided at the other end of the rod-shaped body. Ingredients. A jig for fixing the hot water insulation sleeve to the cast model, provided with a small-diameter portion at one end of the rod-shaped body, and at the side of the small-diameter portion with an equal interval in the circumferential direction of the rod-shaped body, A plurality of elastic strips extending in the direction are arranged, the upper end of each strip is fixed to a ring circumscribing the side surface of the small-diameter portion, and the lower end of each strip is inserted into a hole drilled in the side surface of the small-diameter portion. A hot-water insulation sleeve characterized in that each strip is fixed to a small-diameter portion , each strip is elastically projected outward, and a fixing portion for a cast model is provided at the other end of the rod-shaped body. Fixing jig.

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