JP5484502B2 - Core manufacturing equipment - Google Patents

Description

  The present invention relates to an apparatus for manufacturing a core used when manufacturing a cast product such as a non-ferrous casting and an iron casting by a shell mold casting method, and in particular, sand in a molding chamber formed between molds. Relates to a core manufacturing apparatus in which a plurality of molding chambers having the same shape are formed between molds.

  A core manufacturing apparatus using a blowing method generally includes a pair of molds that can be brought into and out of contact with each other in a horizontal direction, a heating unit that heats the molds to a required temperature, a sand tank above the mold, and a sand tank. A blow unit is provided between the molds, receives a fixed amount of sand from a sand tank, and blows and fills the sand into a plurality of molding chambers between the molds. As a conventional blow unit, there is no specific publicly known document such as a patent gazette, but as shown in FIG. 7, a blow unit 55 that has been conventionally used is an outer case 57 and an outer case. A blow pipe 58 that extends in the vertical direction within 57 and receives the supply of sand from the sand tank 56, and is provided with, for example, two molding chambers 60 of the mold 51 from the blow port 59 at the lower end of the blow pipe 58. 60, sand is blown and filled into two sand filling ports 62, 62 penetrating through the bottom wall portion 57o of the outer case 57 corresponding to the openings 61, 61, respectively.

  In the conventional blow unit 55, when sand is blown and filled by the blow pipe 58, the sand S is discharged from the blow port 59 at the lower end of the blow pipe 58 in a pile shape on the bottom wall portion 57 o of the outer case 57. Shaped sand S is blown into the two molding chambers 60, 60 from the two sand filling ports 62, 62 penetrating the outer case bottom wall 57o by the pressure air from the blow pipe 58. However, since the two molding chambers 60, 60 are blown and filled by the blow port 59 of one blow pipe 58, the height from the outer case bottom wall portion 57o to the blow port 59 at the lower end of the blow pipe 58 is increased. Since the sand S discharged from the blow port 59 onto the outer case bottom wall portion 57o is in a large pile state, the large pile-like sand S is blown into the blow pipe. Evenly blown possible for two sand filling port 62, 62 is difficult in air pressure, susceptible to differences in loading of the sand to the two molding chambers 60, 60.

  Further, as shown in FIG. 7, when the two sand filling ports 62, 62 are not in the bilaterally symmetric position but in the asymmetrical position around the position directly below the blow pipe 58, it can be understood by referring to FIG. 7. In addition, since the left sand filling port 62 is close to the position directly below the blow pipe 58 with respect to the figure, the height of the sand S piled on the left sand filling port 62 is high, and the right sand filling port 62 is. Is far from the position directly below the blow pipe 58, the height of the sand S piled up on the right sand filling port 62 is considerably lower than that on the left side. The filling flow rate of the sand S to be blown and filled in 60 becomes smaller than the filling flow rate of the sand S to be blown and filled into the molding chamber 60 from the sand filling port 62 on the left side, and in the molding chamber 60 having the smaller filling amount, After the molding density of sand S becomes low, Together with a part is likely to occur peel back flake off the child, the strength of the core is weak, thus causing a decrease in quality.

  In view of the above problems, the present invention can blow and fill sand from a blow tube evenly and densely into a plurality of molding chambers formed in a mold, thereby eliminating the occurrence of peelback and molding. An object of the present invention is to provide a core manufacturing apparatus capable of increasing the strength and improving the quality of a core to be manufactured.

Means for solving the above problems will be described with reference numerals in the embodiments described later. The invention according to claim 1 is a pair of molds 1a and 1b that can be moved toward and away from each other in the horizontal direction. A pair of molds 1a, 1b in which a plurality of molding chambers 2 are formed between the molds 1a, 1b, heating means for heating the molds 1a, 1b to a required temperature, and a sand tank above the molds 1a, 1b 5 and 6, between sand tanks 5 and 6 and molds 1a and 1b, and receives a constant supply of sand A and B from sand tanks 5 and 6, and this sand A and B is placed between both molds 1a and 1b. In a core manufacturing apparatus comprising blow units 7 and 8 for blowing and filling a plurality of molding chambers 2
The blow units 7 and 8 are formed from an outer case 35, a main blow pipe 36 that extends in the vertical direction in the outer case 35, receives the supply of sand from the sand tanks 5 and 6, and a lower end portion of the main blow pipe 36. A plurality of branch pipes 37 that are branched downward by the number corresponding to the chamber 2, and each branch pipe 37 has a blow port 38 at the lower end of the outer case 35 corresponding to the opening 3 of each molding chamber 2. It is provided at a required height position close to the sand filling port 39 at a position directly above the sand filling port 39 penetrating the bottom wall portion 35o.

  In the core manufacturing apparatus according to claim 1, the main blow pipe 36 of the blow units 7 and 8 is supported on the upper side in the outer case 35, and the plurality of branch pipes 37 and 37 are: The main blow pipe 36 is formed by branching downward from a separate connection cylinder 48 and is connected to the lower end of the main blow pipe 36 so as to be vertically movable and connected. The cylindrical portion 48 is supported on the lower side in the outer case 35 so as to be movable up and down, and the height η of the blow port 38 can be adjusted by moving the connecting cylindrical portion 48 up and down. To do.

  According to a third aspect of the present invention, in the core manufacturing apparatus according to the second aspect, the connecting tube portion 48 is a screw vertically interposed between the bottom wall portion 48a and the bottom wall portion 35o of the outer case 35. The shaft 64 is supported so as to be movable up and down.

  The effect of the invention by the above-described solution means will be described with reference numerals in the embodiments described later. According to the invention according to claim 1, each branch pipe 37 has a blow port 38 at the lower end thereof in each molding chamber. 2 is provided at a required height position close to the sand filling port 39 at a position directly above the sand filling port 39 penetrating the outer case bottom wall portion 35o corresponding to the opening 3 of each of the two branches. The sands A and B discharged from the blow port 38 of the pipe 37 onto the outer case bottom wall portion 35o are in a relatively small pile state, so that the relatively small piles of sand A and B are in the main blow pipe 36. By the air pressure, each molding chamber 2 is accurately blown and filled from the corresponding sand filling port 39 of the outer case bottom wall portion 35o through the opening 42 of the damper 40. Therefore, the sands A and B from the main blow pipe 36 can be uniformly and densely filled into the two molding chambers 2 and 2 of the molds 1a and 1b, so that a part of the core is formed after molding. As a result, it is possible to produce a high-quality core with high density and excellent strength while eliminating the occurrence of peel-back that peels off.

  According to the invention of claim 2, the main blow pipe 36 of the blow units 7, 8 is supported on the upper side in the outer case 35, and the plurality of branch pipes 37, 37 are separate from the main blow pipe 36. The connecting cylinder part 48 is formed to branch downward from the connecting cylinder part 48. The connecting cylinder part 48 is connected to the lower end part of the main blow pipe 36 so as to be movable up and down, and the connecting cylinder part 48 is connected to the lower side in the outer case 35. Since the height η of the blow port 38 can be adjusted by moving the connecting tube portion 48 up and down, the sand filling from the blow port 38 can be performed by changing and adjusting the height η of the blow port 38. It is possible to adjust the filling flow rate of the sand filled into the molding chamber 2 through the port 39, and to produce the core N having an appropriate filling density according to the material of the sand, the type of the core to be molded, and the like.

  According to the invention of claim 3, by using the screw shaft 64, the structure of the height adjusting means of the blow port 38 is simplified, and the height η of the blow port 38 is easily adjusted by a simple operation. can do.

It is a perspective view which shows the whole core manufacturing apparatus which concerns on this invention. It is a partial cross section front view which shows the blow unit and metal mold | die of the same core manufacturing apparatus. It is a partial cross section side view showing the blow unit and a metallic mold. (a-1) is an explanatory diagram for explaining the operation of the core manufacturing apparatus, (a-2) is a sectional view of the mold, (b-1) is an explanatory diagram for explaining the operation following (a-1) (B-2) are sectional views of the blow unit and the mold. (a-1) is explanatory drawing explaining operation | movement following FIG. 4, (a-2) is sectional drawing of a metal mold | die, (b-1) is explanatory drawing explaining operation | movement following (a-1). (B-2) are sectional views of the blow unit and the mold. (a) is a front sectional view showing the core formed in the mold, (b) is a sectional side view showing the core, and (c) is an external view of the core taken out from the mold. It is sectional explanatory drawing which shows the conventional blow unit.

  A preferred embodiment of the present invention will be described below with reference to the drawings, and a preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a core composed of two layers, an inner layer and an outer layer. The core manufacturing apparatus which manufactures is shown with the perspective view. The core manufacturing apparatus includes a pair of molds 1a and 1b that can be brought into and out of contact with each other in the horizontal direction, and the two mold chambers 1a and 1b are formed between the molds 1a and 1b. 2 and 2 with the openings 3 and 3 facing upward (see (a-1) and (a-2) in FIG. 4) and the positions with the openings 3 and 3 facing downward (see (a-) in FIG. 1) and (a-2)), and a heating means (not shown) for heating the molds 1a and 1b to a required temperature. ), A movable frame 4 movable above the molds 1a and 1b in the same direction as the mold contact / separation direction, and a predetermined pitch P before and after the movable frame 4 is moved on the upper side of the movable frame 4 The outer layer sand tank 5 and the inner layer sand tank 6 and the sand receiving position for receiving a fixed amount of sand directly below the both sand tanks 5 and 6 and directly above the joined molds 1a and 1b. The outer layer blow unit 7 and the inner layer blow unit 8 are capable of advancing and retreating in a direction perpendicular to the moving direction of the movable frame 4 with respect to the filling position where the sand is blown and filled into the molding chambers 2 of the molds 1a and 1b from the opening 3. It is comprised by.

  The pair of molds 1a and 1b are arranged so that their joint surfaces (anastomosis planes) F and F are positioned on a plane perpendicular to the horizontal plane, and one mold 1a includes both molds 1a and 1a, 1b is a fixed mold attached to a mold attachment frame 9a that can be rotated at a fixed position on one end side of a horizontal axis G that passes through the center of each of the central axes 1b, and the other mold 1b includes a horizontal rotation axis G and It is a movable mold attached to a rotatable mold attachment frame 9b that moves in parallel. Although not shown, heating means for heating the molds 1a and 1b to a required temperature is provided inside the mold mounting frames 9a and 9b.

  A pair of guide bars 20, 20 are arranged in parallel on both sides of the horizontal rotation axis G of both molds 1a, 1b, and one end side of both guide bars 20, 20 is integrally connected to the mold mounting frame 9a. The other end sides of the guide bars 20 and 20 are slidably penetrated to the mold mounting frame 9b, and are integrally connected to a rotating frame 21 on the other end side of the horizontal rotation axis G. .

  As shown in FIG. 1, both mold mounting frames 9a and 9b to which the molds 1a and 1b are attached are both rotating shafts (one rotating shaft is indicated by 12 and the other rotating shaft is disposed on the horizontal rotating axis G. The rotating shaft of the cylinder 17 is fixedly connected to the piston rod 17b of the cylinder 17 installed horizontally on the one base 15 of the device frame 14. The piston rod 17b passes through the center of the rotating frame 21, the cylinder tube 17a is fixed on the base 16 by a bracket 18, and the other rotating shaft (not shown) Is supported by a bearing (not shown). Therefore, by the operation of the cylinder 17, the mold mounting frame 9b moves forward and backward with respect to the mold mounting frame 9a, so that the mold 1b contacts and separates from the mold 1a.

  As shown in FIG. 1, a pinion 19 is attached to the other rotating shaft (not shown), and a rack 23 meshing with the pinion 19 is interlocked with a cylinder (not shown) installed on the base 16. The rack 23 is moved by a predetermined stroke by the operation of the cylinder, and the pinion 19 is reversed, whereby the molds 1a and 1b are reversed from the upward position to the downward position and from the downward position to the upward position. It is like that.

  The movable frame 4 shown in FIG. 1 is moved toward and away from the molds 1a and 1b by guide rails 53 and 53 arranged so as to extend in the left-right direction along the upper vertical frames 51 and 52 of the apparatus machine frame 14. It is slidably supported in the same direction as the direction and is driven by a driving cylinder 49.

  Although the two sand tanks 5 and 6 of the outer layer sand tank 5 and the inner layer sand tank 6 are illustrated in a floating state in FIG. 1, the movable frame is actually moved by a tank support mechanism (not shown). 4 is fixed at a predetermined pitch P before and after the movable frame moving direction so as to move integrally with the movable frame 4 in the same direction as the mold contacting / separating direction. The outer layer sand tank 5 and the inner layer sand tank 6 are respectively provided at the sand receiving position directly below the outer layer sand unit 5 and the inner layer blow unit 8 from the lower end supply ports 5a and 5a. A predetermined amount of inner layer sand is supplied.

  As shown schematically in FIGS. 1 and 3, the two blow units 7, 8, the outer layer blow unit 7 and the inner layer blow unit 8, are each provided with a pair of guide rails 31, 31 arranged on the movable frame 4. And two drive cylinders 33 and 34 which are suspended in a slidably supported state by 32 and 32 and are installed in parallel with each other on the movable frame 4, directly below the sand tanks 5 and 6. The sand receiving position that receives a fixed amount of sand is driven forward and backward with respect to the sand filling position that is positioned directly above both molds 1a and 1b in the joined state.

  Further, as shown in FIGS. 2 and 3, the outer layer blow unit 7 and the inner layer blow unit 8 extend in the vertical direction in the outer case 35 and the outer case 35, and sand A main blow pipe 36 that receives supply, two branch pipes 37 and 37 that are bifurcated downward from the lower end of the main blow pipe 36, and a pressure air supply means (not shown), and each branch pipe 37 includes: The blow port 38 at the lower end approaches the sand filling port 39 at a position directly above the sand filling port 39 penetrating the bottom wall portion 35o of the outer case 35 corresponding to the opening 3 of each molding chamber 2. The required height η is provided.

  Describing in more detail about each of the blow units 7 and 8, as shown in FIGS. 2 and 3, the outer case 35 includes a cylindrical main body 35a and a box-shaped base 35b provided on the lower side of the cylindrical main body 35a. The cylindrical main body 35a is detachably attached to the upper part of the box-shaped base 35b. The main blow pipe 36 is inserted concentrically into the cylindrical main body 35a of the outer case 35 from above, and as shown in FIG. The main blow pipe 36 is inserted into the cylindrical main body 35a from the upper end opening 46 thereof at the intervals of 90 ° in the direction. The main blow pipe 36 is suspended at a fixed position in the cylindrical main body 35a as shown in FIG. 2 by being engaged with the inner peripheral step 47a of the cylindrical peripheral wall 47 projecting around the upper end opening 46 of the main body 35a. I am trying to hold it.

  As shown in FIGS. 2 and 3, the two branch pipes 37, 37 are branched into a bifurcated shape integrally from a bottomed cylindrical connecting cylinder 48 having a diameter larger than the outer diameter of the main blow pipe 36. The main blow pipe 36 and the both branch pipes 37, 37 are formed so that the blow port 38 at the lower end of each branch pipe 37 is directly above the sand filling port 39 penetrating the outer case bottom wall portion 35o. At the position of the required height η that is concentric with the sand filling port 39 and held by a screw shaft 64 described later. As shown in FIG. 2, the bottomed cylindrical connecting tube portion 48 is externally fitted to the lower end portion of the main blow tube 36 so as to be movable up and down, and the inner peripheral surface of the connecting tube portion 48 is connected to the main blow tube. A seal member 63 that seals the gap between the outer peripheral surface of the lower end portion of the pipe 36 is attached to the upper end portion of the inner peripheral surface of the connection tube portion 48, and the bottom wall portion 48a of the connection tube portion 48 is in the center of the outer case bottom wall. The upper end portion of the screw shaft 64 erected at the central portion of the portion 35 o is screwed, and the nut member 65 screwed to the screw shaft 64 is turned, whereby the connecting tube portion 48 is connected to both the branch pipes 37, 37. In addition, the height η of the blow port 38 of the branch pipe 37 from the outer case bottom wall portion 35o can be adjusted. When the height η of the blow port 38 is adjusted relatively significantly, the screw shaft 64 is appropriately replaced with a relatively long one or a relatively short one.

  The height η of the blow port 38 from the outer case bottom wall portion 35o is changed to the required height depending on the material of the sand, the type of the core to be molded, etc., but if this height η is increased, The flow rate of sand filling the molding chamber 2 from the blow port 38 of the branch pipe 37 through the sand filling port 39 is increased, and when the height η is decreased, the flow rate of sand is decreased. As shown in this embodiment, in the case of a core manufacturing apparatus that manufactures a core consisting of two layers of an inner layer and an outer layer, the outer layer blow unit 7 sets the height η of the blow port 38 of the branch pipe 37 to be relatively high. Thus, the sand filling flow rate is increased, and in the inner layer blow unit 8, the height η of the branch pipe 37 blow port 38 is set lower than that of the outer layer blow unit 7 to reduce the sand filling flow rate. .

  In this embodiment, as shown in FIG. 2, the main blow pipe 36 of each of the blow units 7 and 8 is located at the center position in the outer case 35 and moves up and down with respect to the lower end portion of the main blow pipe 36. The two branch pipes 37 and 37 branched from the connecting cylinder portion 48 that can be connected are symmetrical with respect to the axis of the main blow pipe 36, but this happens to happen in the molds 1a and 1b. The two molding chambers 2 and 2 to be formed are located symmetrically with respect to the centers of the molds 1a and 1b, and penetrate the bottom wall portion of the outer case corresponding to the openings 3 and 3 of the molding chambers 2 and 2. This is because the provided sand filling ports 39 are provided symmetrically with respect to the center position in the outer case 35. Therefore, if the two molding chambers 2 and 2 are located in the left-right asymmetric position with respect to the mold center, the two branch pipes 37 and 37 are also correspondingly provided. It is formed in an asymmetric shape with respect to the axis of the blow tube 36. In short, the blow port 38 of each branch pipe 37 corresponds to the opening 3 of each molding chamber 2 at a position directly above the sand filling port 39 provided through the bottom wall portion 35 o of the outer case 35. It is important that it is provided at the required height position close to it.

  As shown in FIGS. 2 and 3, the bottom wall portion 35 o of the outer case 35 is provided with an opening / closing damper 40 that opens and closes a sand filling port 39 penetrating the bottom wall portion 35 o. When the damper 40 is driven by the damper driving cylinder 41 to a position where the opening 42 coincides with the sand filling port 39 of the outer case bottom wall portion 35o as shown by the solid line in FIGS. The filling port 39 is opened so that the molding chamber 2 of the molds 1a and 1b can be filled with sand, and the sand filling port 39 is closed by being driven as shown in phantom lines. The damper driving cylinder 41 is installed on a bracket 43 attached to the box-shaped base 35b.

The outer layer sand tank 5 is the outer layer thermosetting resin-coated sand that forms the outer layer of the core, and the inner layer sand tank 6 is the inner layer thermosetting resin coated sand that forms the inner layer of the core. It is appropriately supplied and stored by sand supply means. The outer layer thermosetting resin-coated sand is formed with a larger particle size index than the inner layer thermosetting resin-coated sand. The thermosetting resin-coated sand for the outer layer requires strength enough to withstand pouring, and therefore has a relatively higher strength than the inner layer thermosetting resin-coated sand, specifically, a bending strength of 30 kgf / cm ² or more. Designed to. The amount of thermosetting resin used depends on the refractory particles (type and particle size) and thermosetting resin (type) selected in consideration of the required strength and other mold characteristics (low thermal expansion, etc.). In general, it is in the range of 1 to 10% by weight with respect to the refractory particles, and the range is preferable in consideration of the ease of manufacturing the thermosetting resin-coated sand and the stability of the quality. Is 2 to 6% by weight.

  Moreover, the particle size index of the thermosetting resin-coated sand for the outer layer is generally 80 or more, and preferably in the range of 90 to 160 in view of the ease of production of the thermosetting resin-coated sand. A large particle size index means fine particles, and a small particle size index means coarse particles. As the thermosetting resin-coated sand for the outer layer, a slow-setting thermosetting resin-coated sand having a curing time of 80 seconds or more, particularly 90 seconds or more is preferable from the viewpoint of thinning of the outer layer and close bonding of the inner layer. is there. The curing time means the time from when the thermosetting resin-coated sand is filled in an annular mold (50 mmΦ × 5 mm) placed on a 250 ° C. hot plate until the surface is not pierced with a needle.

On the other hand, the thermosetting resin-coated sand for the inner layer has a relatively lower strength than the thermosetting resin-coated sand for the outer layer, specifically a bending strength of 30 kgf / cm ² in order to impart good disintegration to the mold. Or less, preferably 20 Kgf / cm ² or less. The amount of thermosetting resin used depends on the refractory particles (type and particle size) and thermosetting resin (type) selected in consideration of mold disintegration and gas defects (suppression of generation). Generally, it is less than 2% by weight based on the refractory particles, and the lower limit is about 0.5% by weight from the viewpoint of the reinforcing effect of the outer layer. Further, the thermosetting resin-coated sand for the inner layer is generally set to a particle size index (less than 80) smaller than the thermosetting resin-coated sand for the outer layer from the viewpoint of gas defects (high air permeability), It is in the range of 20-50.

  Next, the operation of the core manufacturing apparatus configured as described above will be described with reference to FIGS. A series of operations as will be described below is performed according to a program previously incorporated in the computer.

  First, referring to FIG. 1 and FIG. 4 (a-1), the mold 1a attached to the fixed mold mounting frame 9a is separated as shown in the phantom line of FIG. The mold 1b is moved close to the mold 1a by extending the mold mounting frame 9b to which the mold 1b is mounted by the cylinder 17, and the both molds 1a and 1b are joined. At this time, the movable frame 4 is in a position as shown in FIG. 1, that is, a position where the molds 1a and 1b can be filled with sand when the outer layer blow unit 7 advances from the sand receiving position to the sand filling position. At this time, the outer layer blow unit 7 and the inner layer blow unit 8 are respectively in the sand receiving positions directly below the outer layer sand tank 5 and the inner layer sand tank 6 as shown in FIG. 4 (a-1). Waiting after receiving a predetermined amount of sand.

  From the state where both molds 1a and 1b are joined as described above, first, the outer layer blow unit 7 is shown in FIG. 4 (a-1) from the sand receiving position as shown in FIG. 4 (b-1). Advancing to such a sand filling position, the thermosetting resin-coated sand A for outer layers is blown and filled into the molding chambers 2 and 2 from the upward openings 3 and 3 of the heated molds 1a and 1b. In this blowing and filling, as shown in FIGS. 2 and 3, the outer layer thermosetting resin-coated sand A in the main blow pipe 36 is divided into two branch pipes 37, 37, and the blow ports 38, 38 through the openings 42 and 42 of the damper 40 opened from the sand filling ports 39 and 39 of the case bottom wall 35o while being discharged in a pile from the bottom wall 35o of the outer case 35 from 38 respectively. 2 and 2 are blown and filled.

  In this case, as can be seen from FIGS. 2 and 3, each branch pipe 37 has a blow port 38 at the lower end thereof penetrating into the bottom wall portion 35 o of the outer case 35 corresponding to the opening 3 of each molding chamber 2. Since it is provided at a required height η close to the sand filling port 39 and concentrically with the sand filling port 39, it is provided on the outer case bottom wall portion 35o from each blow port 38. The outer layer thermosetting resin-coated sand A to be discharged is in a relatively small piled state, and therefore the relatively small piled sand A corresponds to the outer case bottom wall portion 35o by the air pressure in the main blow pipe 36. The molding chamber 2 is filled accurately and with high density from the sand filling port 39 through the openings 42 of the damper 40. If the height η of the blow port 38 is set to be relatively high, the flow rate of sand filling the molding chamber 2 from the blow port 38 of the branch pipe 37 through the sand filling port 39 becomes relatively large, and If the height η is set relatively low, the flow rate of the sand is relatively small. In this case, since the outer layer of the core is formed, the height η of the blow port 38 is set relatively high, By increasing the filling flow rate of the sand A, higher density can be filled, and the strength of the formed outer layer can be further increased.

  As described above, the outer layer resin-coated sand A of the outer layer blow unit 7 is divided into two molding chambers between the molds 1a and 1b by the branch pipes 37 and 37 branched from the lower end of the main blow pipe 36. By blowing and filling 2, both the molding chambers 2, 2 are filled with the outer layer thermosetting resin-coated sand A evenly and densely. A state in which the molding chambers 2 and 2 are filled with the outer layer thermosetting resin-coated sand A is shown in FIG. At this time, the outer layer thermosetting resin-coated sand A receives heat from the molds 1a and 1b heated to a predetermined temperature, and the outer layer portion in contact with the wall surface of the molding chamber 3 is cured by a predetermined thickness. The interior is in an uncured state.

  After the outer layer blow unit 7 is filled with the outer layer thermosetting resin-coated sand A in the molding chambers 2 and 2 of the molds 1a and 1b at the sand filling position, as shown in FIG. The molds 1a and 1b retreat to the sand receiving position, and the molds 1a and 1b are reversed so that the openings 3 and 3 are directed downward by the mold reversal driving means including the pinion 19, the rack 23, and the cylinder. The thermosetting resin-coated sand A for use is discharged downward from the openings 3 and 3, so that the cores are respectively placed in the molding chambers 2 and 2 of the molds 1a and 1b as shown in FIG. 5 (a-2). Outer layers a and a are formed. The outer layer blow unit 7 that has moved back to the sand receiving position is supplied with the outer layer thermosetting resin-coated sand A by the outer layer sand tank 5.

  As described above, when the molds 1a and 1b discharge the uncured outer layer thermosetting resin-coated sand A in the molding chambers 2 and 2 and then reversely return to the position where the opening 3 faces upward, the movable frame 4 moves in the direction of the arrow in FIG. 5 (b-1) by a stroke corresponding to the pitch P (see FIG. 1) of the sand tanks 5 and 6, as shown in FIG. 5 (b-1). The inner layer blow unit 8 that has been waiting at the sand receiving position moves forward from the phantom line illustrated position of FIG. 5 (b-1) to the sand filling position illustrated by the solid line. , 1b, the inner layer thermosetting resin-coated sand B is blown and filled into the outer layers a and a already formed in the molding chambers 2 and 2 through the upward openings 3 and 3 in the molding chambers 2 and 2, respectively.

  The blow filling of the inner layer thermosetting resin-coated sand B by the inner layer blow unit 8 in this case is the same as the blow filling of the outer layer thermosetting resin coated sand A by the outer layer blow unit 7 described above. 2 and FIG. 3, each branch pipe 37 has a sand filling port 39 in which a blow port 38 at the lower end of the branch tube 37 is provided in the outer case bottom wall portion 35 o so as to correspond to the opening 3 of each molding chamber 2. Sand B discharged from each blow port 38 onto the outer case bottom wall portion 35o is provided at a position having a required height η close to the sand filling port 39 and concentric with it. Therefore, the small piled sand B is passed through each opening 42 of the damper 40 from the corresponding sand filling port 39 of the outer case bottom wall portion 35o by the air pressure in the main blow pipe 36. Inside molding chamber 2 Is accurate and densely packed already formed in the outer layer a. Here, in order to form the inner layer b of the core, the height η of the blow port 38 is set lower than that of the blow unit 7 for the outer layer, and the filling flow rate of the sand B is made relatively small. Can be effectively packed to the density. Thus, the inner layer thermosetting resin-coated sand B filled in the outer layers a and a of the molding chambers 2 and 2 of the molds 1a and 1b forms inner layers b and b integrated with the outer layers a and a, respectively. As shown in FIG. 5 (b-2), two cores N and N each having an outer layer a and an inner layer b are formed.

  As shown in FIG. 5 (b-1), the inner layer blow unit 8 is filled with the inner layer thermosetting resin-coated sand B in the molding chambers 2 and 2 of the molds 1a and 1b, respectively. (b-1) The position indicated by the solid line in FIG. 5B is moved back to the sand receiving position directly below the inner layer sand tank 6 indicated by the phantom line in FIG. Receive the supply. As shown in FIG. 6 (a), the molds 1a and 1b in which the core N composed of the outer layer a and the inner layer b is formed in the molding chamber 2 are contracted by the cylinder 17 shown in FIG. As shown in FIG. 6C, the two cores N and N are taken out by being separated from each other by the operation of pulling away the movable side mounting frame 9b. This completes the series of core manufacturing processes.

  As described above, according to the core manufacturing apparatus according to the present invention, the blow units 7 and 8 extend in the vertical direction within the outer case 35 and the outer case 35, and are sand A from the sand tanks 5 and 6. , B, and two branch pipes 37, 37 branched from the lower end of the main blow pipe 36. Each branch pipe 37 has a blow port 38 at its lower end, and each molding Since it is directly above the sand filling port 39 penetrating the outer case bottom wall 35o corresponding to the opening 3 of the chamber 2 and is provided at a required height position close to the sand filling port 39, The sands A and B discharged from the blow port 38 of each branch pipe 37 onto the outer case bottom wall portion 35o are in a relatively small pile state. Therefore, the relatively small piles of sand A and B are the main blow pipe 36. The outer case bottom wall 3 by the air pressure inside It is accurately and densely packed for each forming chamber 2 through the respective openings 42 of the o damper 40 from the corresponding sand filling port 39. Accordingly, the sand A and B from the main blow pipe 36 can be blown and filled evenly and densely into the two molding chambers 2 and 2 of the molds 1a and 1b by the branch pipes 37 and 37, respectively. It is possible to produce a high-quality core N with no strong peel-back that causes a part of the core to be peeled off.

  In the above core manufacturing apparatus, the main blow pipe 36 of the blow units 7 and 8 is suspended on the upper side in the outer case 35, and the plurality of branch pipes 37 and 37 are connected separately from the main blow pipe 36. The connecting cylinder part 48 is formed so as to branch downward from the cylinder part 48, and is connected to the lower end part of the main blow pipe 36 so as to be vertically movable, and the connecting cylinder part 48 is formed on the lower side in the outer case 35. Since the height η of the blow port 38 can be adjusted by moving the connecting cylinder portion 48 up and down, the height η of the blow port 38 can be changed and adjusted. The core flow rate of the sand filled into the molding chamber 2 through the sand filling port 39 can be adjusted to increase or decrease, and a core N having an appropriate filling density according to the type of sand, type of core to be molded, etc. is manufactured. Can do.

  Further, the upper end portion of the screw shaft 64 erected at the center portion of the outer case bottom wall portion 35 o is screwed into the center of the bottom wall portion 48 a of the connecting tube portion 48, and is screwed onto the screw shaft 64. By turning the nut member 65, the connecting cylinder portion 48 can be moved up and down together with the two branch pipes 37, 37, so that the height η of the blow port 38 can be easily adjusted by a simple operation. In this embodiment, the screw shaft 64 is fixed, the connecting tube portion 48 is supported by the nut member 65 screwed to the screw shaft 64, and the connecting tube portion 48 is moved up and down by rotating the nut 65. However, a nut member is fixedly provided on the bottom wall portion 48a of the connecting tube portion 48, and the upper end portion side of the screw shaft is screwed to the nut member, and the lower end portion of the screw shaft is connected to the outer case 35. If pivotally supported on the bottom wall portion 35o, the connecting tube portion 48 can be moved up and down by rotating the screw shaft. In any case, by using the screw shaft, the structure becomes simple and the height η of the blow port 38 can be adjusted by a simple operation. In addition, when the height η of the blow port 38 is significantly adjusted, the screw shaft 64 may be appropriately replaced with a relatively long one or a relatively short one.

  In the core manufacturing apparatus of the above-described embodiment, the two branch pipes 37 and 37 are branched in a bifurcated manner from the lower end portion of the main blow pipe 36, but the branch pipe 37 is branched into two. The invention is not limited to this, and it may be branched into three or more and blown and filled with sand into three or more molding chambers.

  In the above-described embodiment, the core manufacturing apparatus for manufacturing the core N composed of the two layers of the outer layer a and the inner layer b has been described. Of course, the present invention is not limited to a single layer core or a hollow core. The present invention is also applied to a core manufacturing apparatus that manufactures a child.

1a, 1b Mold 2 Mold molding chamber 3 Molding chamber opening 5, 6 Sand tank 7, 8 Blow unit 9a, 9b Mold mounting frame 35 Blow unit outer case 35o Outer case bottom wall 36 Main blow pipe 37 Branch pipe 38 Blow port 39 Sand filling port 40 Damper 48 Connection cylinder part 64 Screw shaft 65 Nut member A Outer layer thermosetting resin coated sand B Inner layer thermosetting resin coated sand a Core outer layer b Core inner layer N core

Claims (3)

A pair of molds that can be brought into and out of contact with each other in the horizontal direction, a pair of molds in which a plurality of molding chambers are formed between the molds, heating means for heating the molds to a required temperature, and above the molds In a core manufacturing apparatus comprising a sand tank and a blow unit that receives a constant amount of sand from the sand tank and blows and fills the sand into a plurality of molding chambers between the molds. ,
The blow unit is branched downward by the number corresponding to the molding chamber from the outer case, the main blow pipe extending in the vertical direction in the outer case and receiving the supply of sand from the sand tank, and the lower end of the main blow pipe. A plurality of branch pipes, each branch pipe has a blow port at the lower end thereof directly above the sand filling port provided in the bottom wall portion of the outer case corresponding to the opening of each molding chamber, A core manufacturing apparatus provided at a required height position close to the sand filling port.   The main blow pipe of the blow unit is supported on the upper side in the outer case, and the plurality of branch pipes are formed by branching downward from a connecting cylinder part separate from the main blow pipe. The cylinder part is connected to the lower end part of the main blow pipe so as to be movable up and down, and the connection cylinder part is supported on the lower side in the outer case so as to be movable up and down, and the connection cylinder part is moved up and down. The core manufacturing apparatus according to claim 1, wherein a height of the blow port can be adjusted.   The said connection cylinder part is supported by the screw shaft perpendicularly interposed between the bottom wall part and the bottom wall part of the said outer case so that an up-and-down movement is possible. Core manufacturing equipment.

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