Mold preheating system and positioning device

Abstract

To provide a mold preheating system and a positioning device which can efficiently arrange burners.SOLUTION: A mold preheating system includes a casting mold 1 for obtaining a cast product by supplying molten metal to a cavity part 2 formed of an upper mold 3 and a lower mold 4, a mold preheating device 10 for preheating the casting mold 1, and a positioning device 30 which is mounted between the upper mold 3 and the lower mold 4, and supports the mold preheating device 10. The mold preheating device 10 includes a burner 11 for upper mold preheating which preheats the upper mold 3, and a burner 12 for lower mold preheating which preheats the lower mold 4. The positioning device 30 has: a lower mold engagement part 36 which is engaged with the lower mold 4; an upper mold regulation part 37 which is engaged with the upper mold 3, and regulates a relative position of the upper mold 3 with respect to the lower mold 4 ; a burner positioning part 40 for upper mold preheating which positions the position of the burner 11 for upper mold preheating with respect to the upper mold 3; and a burner positioning part 50 for lower mold preheating which positions the position of the burner 12 for lower mold preheating with respect to the lower mold 4.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a mold preheating system and a positioning device. [Background technology]

[0002] Conventionally, casting dies are known in which molten metal is supplied into a cavity formed by an upper die and a lower die to obtain a cast product. In such casting dies, a burner is provided to preheat the casting die in advance, and the die is heated to a desired temperature before the molten metal in the melting furnace is supplied, thereby reducing the number of preheating steps (for example, Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 7-98259 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in order to obtain a sufficient preheating effect with a small amount of air-fuel mixture, it is necessary to arrange the burners at appropriate intervals from each part of the mold. Therefore, there is room for further improvement in order to obtain good quality casting products in a short time from the first time without performing trial castings. An object of the present invention is to provide a mold preheating system and a positioning device that enable efficient arrangement of burners. [Means for solving the problem]

[0005] In order to solve the above problems, the mold preheating system of the present invention includes a casting mold for supplying molten metal to a cavity formed by an upper mold and a lower mold to obtain a casting product, a mold preheating device for preheating the casting mold, and a positioning device placed between the upper mold and the lower mold for supporting the mold preheating device. The mold preheating device includes an upper mold preheating burner for preheating the upper mold and a lower mold preheating burner for preheating the lower mold, and the positioning device includes a lower mold engaging portion for engaging with the lower mold, an upper mold regulating portion for engaging with the upper mold to regulate the relative position of the upper mold with respect to the lower mold, an upper mold preheating burner positioning portion for positioning the position of the upper mold preheating burner with respect to the upper mold, and a lower mold preheating burner positioning portion for positioning the position of the lower mold preheating burner with respect to the lower mold. Effect of the Invention

[0006] According to the present invention, a mold preheating system and a positioning device are provided that allow efficient arrangement of burners. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a vertical cross-sectional view of the mold preheating system according to the embodiment of the present invention in a state where the casting mold is opened. [Diagram 2] FIG. 2 is a perspective view showing the mold preheating device with the front and rear burner tips removed for explanation. [Diagram 3] FIG. 2 is a perspective view showing the overall configuration of a positioning device used in the mold preheating system. [Figure 4] FIG. 2 is a perspective view showing a state in which the mold preheating device is supported by the positioning device. [Diagram 5] FIG. 4 is a plan view showing a state in which the mold preheating device is supported by the positioning device. [Figure 6] FIG. 11 is an exploded perspective view illustrating a state in which a positioning device supporting a mold preheating device is attached to a casting mold in the mold preheating system according to the embodiment. [Figure 7] 1 is a vertical cross-sectional view of a state in which a positioning device for supporting a mold preheating device is mounted between an upper mold and a lower mold of a casting mold. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Embodiment] Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate. The same components are given the same reference numerals, and duplicated descriptions will be omitted. In the description, the same components are given the same reference numerals, and duplicated descriptions will be omitted. For convenience of description, when describing directions, the directions indicated by the arrows in FIG. 1 are referred to as "up, down, left, right," and the front side of the paper in FIG. 1 is referred to as "front," and the back side of the paper is referred to as "rear."

[0009] [Mold preheating system] The mold preheating system 100 of the present invention shown in Fig. 1 includes a casting mold 1 for obtaining a cast product by supplying molten metal to a cavity 2 as a hollow space formed by an upper mold 3 and a lower mold 4. The casting mold 1 includes an opening / closing mechanism (not shown) for changing the vertical distance between the upper mold 3 and the lower mold 4 by moving the upper mold 3 in the vertical direction. The opening and closing mechanism changes the mold open state in which the upper mold 3 is separated upward from the lower mold 4 to a mold closed state in which the upper mold 3 is moved downward and brought into contact with the lower mold 4. Next, molten metal supplied from a melting furnace 5 provided below the lower mold 4 is poured into the cavity portion 2 through a molten metal supply passage 6, and low-pressure casting is performed. The die preheating system 100 performs a preheating process to preheat the casting die 1 before low pressure casting. The die preheating system 100 of the embodiment includes a die preheating device 10 that completes the preheating process of the upper die 3, the lower die 4, and the molten metal supply passage 6 in a short time, eliminating the need for waste casting, and a positioning device 30 that is placed between the upper die 3 and the lower die 4 and supports the die preheating device 10.

[0010] [Casting mold] A convex portion 3a that forms the product shape of a casting product is provided on the upper mold 3 of the casting mold 1. The convex portion 3a in the embodiment has a rectangular truncated shape with substantially flat outer peripheral walls 3b arranged on all four sides and tapered inwardly as it extends downward. Furthermore, four convex engaging portions (guide posts) 3j are protruding from the lower surface 3c of the upper mold 3 at each of the four corners. Engaged portions (guide portions) 4j are recessed and formed at each of the four corners of the upper surface 4f of the outer periphery of the lower mold 4. Each engaging portion 3j guides the upper mold 3 when the mold is opened or closed, and engages with the engaged portions 4j in the mold clamped state.

[0011] The lower die 4 of the casting mold 1 is further provided with a slide mold section 7 which is horizontally movable in the lateral opening direction. The slide mold section 7 is provided so as to be able to slide horizontally from the center of the cavity section 2 to approach and separate from each other. The slide mold section 7 forms an internal space of the cavity section 2 in the mold closed state, and shapes the uneven shape of the side surface of the casting product. Furthermore, when the slide mold section 7 slides outward in the mold open state, at least one side surface is opened, allowing the casting product to be easily removed.

[0012] A concave portion 4a is formed in the slide mold portion 7 of the lower mold 4. The upper portion of the concave portion 4a opens its upper opening upward and slopes inward as it approaches downward. In addition, the internal space of the cavity portion 2 is formed in the lower portion of the concave portion 4a and is surrounded by a side wall 4b. When the upper mold 3 is lowered from the mold open state, the convex portion 3a is accommodated in the concave portion 4a, and the casting mold 1 is closed in the vertical direction.

[0013] A plurality of gates 14 are formed on the bottom wall of the lower mold 4. The gates 14 are formed at four locations approximately equally spaced apart along the inner peripheral wall 15a of the intermediate stalk 15 when viewed from above, and communicate with the melting furnace 5 arranged below the lower mold 4 via the molten metal supply passage 6. The melting furnace 5 sends molten metal, which is a molten metal material, from bottom to top at a relatively low pressure and at a low speed into the cavity portion 2 through a molten metal supply passage 6 provided between the melting furnace 5 and the casting mold 1. The molten metal supply passage 6 has a cylindrical intermediate stalk 15 at its upper end. The upper end surface of the intermediate stalk 15 is connected to the lower surface of the bottom wall 4c of the lower mold 4. The molten metal pushed up from the melting furnace 5 through the intermediate stalk 15 is distributed to each of the four gates 14 and sent into the cavity portion 2. The molten metal poured into the cavity portion 2 hardens as it cools, becoming a cast product.

[0014] [Mold preheating device] The die preheating device 10 is interposed between the upper die 3 and the lower die 4 in an open state before low-pressure casting, and preheats the casting die 1 to a desired temperature by ejecting flames from multiple burner tips. 2 has an upper die preheating burner 11 arranged along the outer peripheral wall 3b of the convex portion 3a to preheat the outer peripheral wall 3b, a lower die preheating burner 12 arranged inside the concave portion 4a to preheat the side wall 4b of the concave portion 4a, and a piping branch section 23 connected to the upper die preheating burner 11 and the lower die preheating burner 12. The die preheating device 10 also has a middle stalk preheating burner 13.

[0015] The upper mold preheating burner 11 has upper mold piping 11c surrounding at least three of the multiple outer peripheral walls 3b formed on the convex portion 3a of the upper mold 3. The upper die pipe 11c has two straight pipes 11f arranged parallel to the left and right outer peripheral walls 3b of the convex portion 3a with a predetermined interval between them. Each straight pipe 11f has a first row burner tip 11a and a second row burner tip 11b that eject flames toward two surfaces located on the left and right opposite sides of the outer peripheral wall 3b, and a front burner tip 11d and a rear burner tip 11e. Note that the front burner tip 11d and the rear burner tip 11e are omitted in Figs. 2 and 4 (see Fig. 5). In the embodiment, the first row burner tip 11a, the second row burner tip 11b, the front burner tip 11d and the rear burner tip 11e are arranged toward four surfaces, but this is not particularly limited. For example, two or three surfaces may be used, as long as the flames are ejected toward at least two surfaces.

[0016] Furthermore, the piping branching section 23 is connected to a mixture supplying device 20 (see FIG. 5) that supplies a mixture of air and combustion gas (hereinafter, also referred to as a mixture) via the mold piping 22. The piping branching section 23 distributes the mixture supplied from the mixture supplying device 20 to each straight pipe 11f, 11f of the upper mold piping 11c. Then, flames are ejected from the first row burner tips 11a and the second row burner tips 11b obliquely upward so as not to be localized, thereby uniformly preheating a wide range on the lower end surface 3f of the convex portion 3a and the four surfaces of the outer peripheral wall 3b.

[0017] The lower die preheating burner 12 also has a lower die pipe 12b that branches downward from the pipe branching section 23 and bends horizontally. The lower die pipe 12b extends horizontally to the middle of the space in the cavity section 2 of the lower die 4, and has a crank shape with its tip 12c bent downward. The burner tip assembly 12a of the lower die preheating burner 12 is connected to the tip 12c of the lower die pipe 12b. The burner tip assembly 12a has a rectangular parallelepiped shape with multiple burner tips assembled together. Then, the inner wall including the side wall 4b of the lower mold 4 is uniformly preheated by the flames ejected from each burner tip of the burner tip assembly 12a.

[0018] Furthermore, the intermediate stalk preheating burner 13 is located below the mold piping 22 and has an intermediate stalk piping 24 to which the mixture is separately supplied from the mixture supply device 20. The intermediate stalk piping 24 is connected to the straight pipe 11f and a intermediate stalk piping branch section 26 that extends horizontally at a constant interval in the vertical direction. The intermediate stalk piping branch section 26 has branch pipes 26a, 26a that branch out toward both the left and right sides of the cavity section 2 and are arranged in parallel at a predetermined interval. An L-shaped pipe 25, which is L-shaped when viewed from the front, is connected to the tip 26b of each branch pipe 26a, perpendicular to the extension direction. A supported portion 25a is provided at the round tubular outer end of each L-shaped pipe 25. The supported portion 25a protrudes outward in the left-right direction from the tip 26b of the branch pipe 26a (see FIG. 5).

[0019] 2, the lower end 25b of each L-shaped pipe 25 is connected to a tip mounting pipe 28 that branches out into front and rear and extends downward. A plurality of supply path burner tips 27 are attached to the outer surfaces of the lower parts of the four tip mounting pipes 28. In the embodiment, three supply path burner tips 27 are provided on each tip mounting pipe 28 so as to protrude along the tube axis direction, and the flame ejection direction is oriented to intersect with the radial direction of the intermediate stalk 15. In general, if the flame of the supply passage burner tip 27 is directed in a direction perpendicular to the inner peripheral wall 15a, the inner peripheral wall 15a may become locally hot and may be damaged. In contrast, the intermediate stalk preheating burner 13 of the embodiment has tip mounting pipes 28 inserted into the intermediate stalk 15 from multiple gates 14 (see FIG. 1), and ejects flames from each supply passage burner tip 27 rotated in the circumferential direction along the inner circumferential wall 15a. In other words, the supply passage burner tip 27 ejects flames in a direction intersecting the radial direction of the intermediate stalk 15, and can preheat the inner circumferential wall 15a evenly.

[0020] [Positioning device] 3, the positioning device 30 of the embodiment includes a base 31 placed on the upper surface of the lower mold 4. A front-rear frame 32 and a left-right frame 33 are provided on the lower part of the base 31. The orthogonal intersecting portions 31b to 31e are connected to each other to form a generally rectangular frame shape in plan view having a square opening 31f. Of these, the front and rear frames 32 have a long plate-like front frame material 32a and a rear frame material 32b with an L-shaped cross section. Additionally, the left and right frames 33 each have a left frame material 33a and a right frame material 33b with an L-shaped cross section.

[0021] The lower part of the base 31 has a flat lower surface 31a having approximately the same size as the periphery of the upper surface 4f of the lower die 4. The base 31 is placed on the lower die 4 in a stable state with at least a part of the lower surface 31a overlapping in the vertical direction parallel to the upper surface 4f of the lower die 4. As a result, the space within the cavity portion 2 and the opening 31f of the base 31 are aligned, and the space above the base 31 and the spaces within the lower mold 4 and the intermediate stalk 15 are communicated in the vertical direction via the opening 31f.

[0022] Further, at three of the four intersections of the stand 31, ie, intersections 31b, 31c, and 31e, upper die regulating portions 37 that engage with the upper die 3 to regulate the relative position of the upper die 3 with respect to the lower die 4 are provided. The upper die regulating portion 37 of the embodiment includes three cylindrical portions 34, 34, 35 protruding upward from each of the intersections 31b, 31c, 31e, and a round hole 38 recessed downward from the upper end of each of the cylindrical portions 34, 34, 35. In the preheating process, the lower surface 3c of the upper die 3 comes into contact with the upper ends of the cylindrical portions 34, 34, 35. At this time, the round holes 38 engage with engagement portions (guide posts) 3j protruding from the upper die 3 (see FIG. 7). Then, by adjusting a predetermined vertical dimension H1 from the upper end of the cylindrical portion 34 etc. to the lower surface 31a of the stand 31, the movement of the upper die 3 approaching the lower die 4 can be stopped at a desired position. Therefore, when the stand 31 is interposed between the lower die 4 and the upper die 3 in the preheating process, the distance between the upper die 3 and the upper die preheating burner 11 positioned and fixed to the stand 31 can be regulated to a desired size.

[0023] In the positioning device 30 of the embodiment, the vertical dimension H1 of the cylindrical portion 34 etc. shown in FIG. 3 is set to be smaller than the separation dimension H2 (see FIG. 1) between the upper mold 3 and the lower mold 4 when the molds are opened to the maximum extent, such as when removing a casting product. A separation dimension H3 (see FIG. 7) between the upper mold 3 and the lower mold 4 in the preheating step is set to be smaller than a separation dimension H2 (see FIG. 1) in the mold open state. This allows the distance between the upper die preheating burner 11 and the convex portion 3a of the upper die 3 to be accurately regulated, and allows them to approach each other to a desired distance position.

[0024] Furthermore, lower die engaging parts 36, 36 are respectively provided to protrude from each of the intersections 31b, 31c of the base 31. The lower die engaging parts 36 are cylindrical and protrude downward from the lower surface side of the front and rear frames 32. Each lower die engaging part 36 is provided so as to be continuous in the up-down direction with each of the cylindrical parts 34, 34, with the central axis line coinciding with each other. Then, each lower die engaging part 36 is inserted into and engaged with the engaged part 4j of the lower die 4 when the base 31 is placed on the lower die 4 (see FIG. 6). At this time, the lower die engaging parts 36, 36 are easily inserted into the engaged part 4j at only two points. Therefore, the installation and removal of the base 31 can be easily performed.

[0025] As shown in Figure 3, the positioning device 30 of the embodiment includes an upper mold preheating burner positioning section 40 that positions the position of the upper mold preheating burner 11 relative to the upper mold 3, a lower mold preheating burner positioning section 50 that positions the position of the lower mold preheating burner 12 relative to the lower mold 4, and an intermediate stalk preheating burner positioning section 60. Of these, the upper mold preheating burner positioning portion 40 has a pair of left and right base end side pipe holding portions 42, 42 and a tip end side pipe holding portion 44, 44. The base end side pipe holding portions 42 are provided on both the left and right sides of the pipe branch portion 23 in the horizontal direction. The base-end pipe holding portion 42 has a rear long plate 42a that protrudes upward from the upper surface of the rear frame material 32b, and a U-shaped branch pipe receiving portion 42b that is formed at the upper end of the rear long plate 42a and is open upward. The branch pipe receiving portion 42b engages and holds from above the base portions of the upper mold piping 11c of the upper mold preheating burner 11, which are connected to the piping branch portions 23 from the left and right (see FIG. 4).

[0026] Further, the tip side pipe holding portions 44, 44 hold the positions of the straight pipes 11f near the tip sides thereof spaced apart from the pipe branch portion 23. The tip-side pipe holding portion 44 has a pair of front long plates 44a protruding upward from positions spaced apart to the left and right on the upper surface of the front frame material 32a, and a U-shaped straight pipe receiving portion 44b formed at the upper end of each front long plate 44a and open upward. Each branch pipe receiving portion 42b engages with and holds the tip end side of each straight pipe 11f of the upper mold preheating burner 11 from above (see FIG. 4).

[0027] Furthermore, the vertical positions of the branch pipe receiving portion 42b and the straight pipe receiving portion 44b are aligned at the same height in the same horizontal plane, so that the upper mold preheating burner positioning portion 40 can hold the upper mold preheating burner 11 at a desired height and horizontally.

[0028] In the embodiment, the upper mold preheating burner positioning portion 40 has the out-of-plane directions of the rear long plate 42a and the front long plate 44a differing from each other by 90 degrees (see Figs. 3 and 5). This restricts the movement of the upper mold pipe 11c held by the branch pipe receiving portion 42b in the front-rear direction, and restricts the movement of each straight pipe 11f held by the straight pipe receiving portion 44b in the left-right direction (see Figs. 4 and 5). Therefore, the front-rear and left-right positions of the upper mold preheating burner 11 are accurately determined so as to be at the desired position and angle.

[0029] The lower-die preheating burner positioning portion 50 has a lower-die piping holding portion 52 that holds the lower side of the lower-die piping 12b that is horizontally extended below the piping branch portion 23. The lower die pipe holding portion 52 of the embodiment has an extension plate 52a that is generally L-shaped in side view and extends from between the rear long plates 42a, 42a on the upper surface of the rear frame material 32b toward the center of the opening 31f, and a lower support portion 52b that is U-shaped and opens upward at the upper end portion bent upward of the extension plate 52a. Of the lower die pipe holding portion 52, the vertical dimension of the extension plate 52a is shorter than the vertical dimension of the base end pipe holding portion 42. As a result, the lower die pipe 12b (see FIG. 4) held by the lower support portion 52b is arranged parallel to the branch pipe support portion 42b at a predetermined interval in the vertical direction.

[0030] The lower mold preheating burner 12 is supported at two points: the piping branching portion 23 and a lower support portion 52b that holds the lower side of the lower mold piping 12b that branches downward from the piping branching portion 23. Therefore, the lower die piping 12b is stably extended horizontally into the space within the cavity portion 2 of the lower die 4, and the burner tip assembly 12a can be accurately suspended at the desired central position within the space.

[0031] Furthermore, the positioning device 30 is equipped with a middle stalk preheating burner positioning portion 60. The middle stalk preheating burner positioning portion 60 holds the middle stalk preheating burner 13, which is inserted downward from both the left and right sides of the lower mold preheating burner 12 (see FIG. 3), in a position within the middle stalk 15 that provides good preheating efficiency. The intermediate stalk preheating burner positioning portion 60 in this embodiment has a vertical holding portion 62 that regulates the vertical position of the supply line burner tip 27 relative to the molten metal supply line 6, and a tilt prevention holding portion 64 that holds the intermediate stalk piping 24 or the intermediate stalk piping branch portion 26 to prevent the intermediate stalk piping 24 from tilting.

[0032] Of these, the vertical holding portion 62 has an intermediate short plate 62a protruding upward from the upper surfaces of the left frame member 33a and the right frame member 33b, and a U-shaped support pipe receiving portion 62b formed at the upper end of the intermediate short plate 62a and open upward. As shown in Fig. 4, the intermediate stalk pipe branch section 26 is provided with a pair of support pipe sections 24a, 24a that protrude horizontally to the left and right. Each support pipe section 24a in the embodiment is supported on the frame 31 and extends to the outside across the left frame member 33a and the right frame member 33b. Each support pipe receiving portion 62b receives and holds the corresponding support pipe portion 24a in the up-down direction (see FIG. 6).

[0033] The tilt prevention holder 64 holds both sides of the intermediate stalk pipe branch portion 26, which is formed by branching the intermediate stalk pipe 24 shown in FIG. 3 to the left and right, from below. The anti-tilt holder 64 has a rear short plate 64a that protrudes upward from the upper surface of the rear frame material 32b, and a U-shaped intermediate stalk receiving portion 64b that is formed at the upper end of the rear short plate 64a and is open upward. In this embodiment, the longitudinal (vertical) dimensions of the middle short plate 62a and the rear short plate 64a are set shorter than the longitudinal dimensions of the front long plate 44a and the rear long plate 42a.

[0034] In the intermediate stalk preheating burner positioning portion 60 of the embodiment, the out-of-plane directions of the intermediate short plate 62a and the rear short plate 64a are offset by 90 degrees from each other (see Figs. 3 and 5). This restricts the movement of the supported portion 25a held by the support pipe receiving portion 62b in the front-rear direction, and restricts the movement of the intermediate stalk piping branch portion 26 held by the left and right intermediate stalk receiving portions 64b, 64b in the left-right direction. Therefore, the front-rear, left-right, and up-down positions of the intermediate stalk preheating burner 13 are accurately maintained at the desired positions.

[0035] For example, when the position of the intermediate stalk receiving portion 64b changes in the vertical direction, the support pipe portion 24a rotates with the support pipe receiving portion 62b as a fulcrum, causing the tip mounting pipe 28 to tilt from the vertical direction. For this reason, in this embodiment, the vertical positions of the support pipe receiving portion 62b and the intermediate stalk receiving portion 64b are aligned horizontally and set to the same height, so that the tip mounting pipe 28 hangs down vertically. As a result, as shown in FIG. 1, the tip mounting pipe 28 is inserted at an angle straight down from the gate 14 into the intermediate stalk 15 and held at a desired height.

[0036] [Preheating process] 4 and 5, the upper die preheating burner 11 and the lower die preheating burner 12 of the die preheating device 10 are supported by the upper die preheating burner positioning portion 40 and the lower die preheating burner positioning portion 50 of the positioning device 30. In addition, the middle stalk preheating burner 13 is supported by the middle stalk preheating burner positioning portion 60. In the preparation stage for the preheating process shown in FIG. 6, the upper mold preheating burner 11, the lower mold preheating burner 12 and the intermediate stalk preheating burner 13 are supported by a positioning device 30 and interposed between the upper mold 3 and the lower mold 4 in the mold open state. As shown in Figure 7, when the stand 31 of the positioning device 30 is placed on the upper surface 4f of the lower mold 4, the three lower mold engaging portions 36 of the stand 31 are guided and engaged in the vertical direction with respect to the engaged portions (guide portions) 4j recessed in the four corners of the upper surface 4f of the lower mold 4. As a result, the base 31 of the positioning device 30 is positioned and fixed horizontally at a desired position in the up-down, front-back and left-right directions relative to the lower mold 4 without tilting.

[0037] In addition, the lower surface 31a of the base 31 in the embodiment is placed so as to be at least partially parallel to the upper surface 4f of the lower die 4 in the vertical direction. Therefore, the base 31 is further stably positioned and fixed on the lower die 4 without wobbling. In general, for example, if the lower part of the stand 31 is unsteady at the engagement portion with the upper side surface 4f of the lower die 4 due to dimensional errors or the like, the position of the upper die preheating burner 11 held on the upper part of the stand 31 will be significantly affected and will fluctuate. In contrast, the positioning device 30 of the embodiment has the lower side surface 31a of the stand 31 in a parallel and flush state with the upper side surface 4f, and is stably placed on the lower die 4, improving the positional accuracy of the upper part.

[0038] Furthermore, the two lower die engaging parts 36 protruding from the lower surface 31a of the base 31 easily engage with the engaged parts 4j, respectively. Therefore, the space in the cavity 2 and the opening 31f of the base 31 match up in the vertical direction, and the lower die preheating burner 12 and the intermediate stalk preheating burner 13 can be easily inserted and positioned from the upper space of the base 31 toward the space in the lower die 4 and the intermediate stalk 15.

[0039] Next, when the upper mold 3 is lowered from the mold open state in the mold clamping direction to approach the lower mold 4 by using the opening / closing mechanism, three of the four engagement parts 3j protruding from the four corners of the lower surface 3c of the upper mold 3 engage with the respective round holes 38 recessed in the upper end of each of the cylindrical parts 34, 34, 35, as shown in Fig. 6. At this time, the base 31 is stably placed on the lower mold 4 and engaged in the correct position. Therefore, each engagement part 3j is easily inserted and engaged with each of the round holes 38 that exist on the same central axis as the cylindrical parts 34, 34, 35.

[0040] 7, in the preparation stage for the preheating step, the lowering position of the upper die 3 is restricted by the vertical dimension H1 of each of the cylindrical portions 34, 34, 35. In addition, the upper ends of the cylindrical portions 34, 34, 35 support the upper die 3 from below at three points. For example, when supporting at multiple points such as four points, if the dimensional accuracy is low, not all of the engaging parts will be aligned in one plane, resulting in gaps. In this embodiment, the upper die regulating portion 37 supports the upper die 3 at three points. Therefore, all of the engaging parts will always be engaged evenly in one plane. Also, each engaging portion 3j will accurately match and engage with the round hole 38. Therefore, it is possible to reduce the tolerance between the engaging portions 3j and the round holes 38, and further improve the positional accuracy of the upper part of the stand 31.

[0041] In the preheating step, each of the cylindrical portions 34, 34, 35 is sandwiched between the upper die 3 and the lower die 4 to restrict the downward movement of the upper die 3. As a result, the downward movement of the upper die 3 is stopped at a desired vertical position, and the separation dimension H3 between the upper die 3 and the lower die 4 is maintained at a desired size. For example, the upper mold preheating burner 11 supported at a desired position by the positioning device 30 can accurately position each of the first row burner tips 11a and second row burner tips 11b, each of which has improved positioning accuracy, close to the area to be preheated, such as the outer peripheral wall 3b of the convex portion 3a of the upper mold 3, and at a desired relative angle. This improves preheating efficiency compared to the case where sufficient positional accuracy is not provided and the burner tip must be spaced apart to avoid contact with the inner wall of the cavity portion 2. Also, the spacing dimension H3 between the upper die 3 and the lower die 4 shown in Fig. 7 can be made smaller than the spacing dimension H2 in the further mold-open state shown in Fig. 1. This reduces the amount of heat escaping from the gap between the upper die 3 and the lower die 4, further improving preheating efficiency.

[0042] The lower mold preheating burner 12 of the embodiment is positioned at a plurality of positions by the lower mold pipe holding portion 52 and the pipe branching portion 23 provided in the lower mold preheating burner positioning portion 50 of the positioning device 30 shown in Fig. 3. The pipe branching portion 23 is held at both left and right sides by the base end side pipe holding portions 42, 42 of the upper mold preheating burner positioning portion 40. Therefore, as shown in Fig. 4, the lower mold pipe 12b is stably extended in the horizontal direction to the inside of the recessed portion 4a, and the lower mold pipe 12b has the burner tip assembly portion 12a connected to the crank-shaped tip 12c accurately positioned at the middle position between the opposing both side wall surfaces in the cavity portion 2 (see Fig. 7). Therefore, the flames ejected from the multiple burner tips of the burner tip assembly 12a can preheat each side wall surface uniformly and efficiently.

[0043] Furthermore, the intermediate stalk preheating burner positioning portion 60 shown in Fig. 3 accurately positions and holds the intermediate stalk preheating burner 13 by a plurality of vertical direction holding portions 62 and tilt prevention holding portions 64 provided on the intermediate stalk preheating burner positioning portion 60 of the positioning device 30 (see Fig. 4). Therefore, as shown in Fig. 7, in the preheating process, the tip mounting pipe 28 is inserted and fixed at a desired height position without tilting in the intermediate stalk 15. Therefore, the supply path burner tips 27 attached to the tip mounting pipe 28 can be directed to the desired positions and angles. Therefore, the intermediate stalk 15 and the molten metal supply passage 6 can be sufficiently preheated without the intermediate stalk preheating burner 13 being in contact with the wall surface of the intermediate stalk 15.

[0044] [Low pressure casting process] After the preheating process is completed, the opening and closing mechanism temporarily moves the upper mold 3 upward as shown in FIG. 1 to open the mold, and removes the positioning device 30, the upper mold preheating burner 11, the lower mold preheating burner 12, and the intermediate stalk preheating burner 13 from between the upper mold 3 and the lower mold 4. Next, low pressure casting is performed. In the low pressure casting process, the opening and closing mechanism first moves the upper mold 3 downward, and the upper mold 3 and the lower mold 4 are clamped together. The molten metal is then pushed up from the melting furnace 5 through the stalk portion and intermediate stalk 15 (not shown), and is distributed from the four gates 14 and sent into the cavity portion 2. The molten metal poured into the cavity portion 2 is cooled through the casting mold 1 and hardens to become a cast product. The opening and closing mechanism again moves upper die 3 upward to the mold open state. Then, the casting product is removed from between upper die 3 and lower die 4 of casting mold 1.

[0045] As described above, the mold preheating system 100 of the embodiment includes a casting mold 1 that supplies molten metal to a cavity portion 2 formed by an upper mold 3 and a lower mold 4 to obtain a casting product, a mold preheating device 10 that preheats the casting mold 1, and a positioning device 30 that is placed between the upper mold 3 and the lower mold 4 and supports the mold preheating device 10. The die preheating device 10 includes an upper die preheating burner 11 that preheats the upper die 3, and a lower die preheating burner 12 that preheats the lower die 4. The positioning device 30 includes a lower die engaging portion 36 that engages with the lower die 4, an upper die regulating portion 37 that engages with the upper die 3 to regulate the relative position of the upper die 3 with respect to the lower die 4, an upper die preheating burner positioning portion 40 that positions the position of the upper die preheating burner 11 with respect to the upper die 3, and a lower die preheating burner positioning portion 50 that positions the position of the lower die preheating burner 12 with respect to the lower die 4.

[0046] In the embodiment of the mold preheating system 100 configured in this manner, the burners can be arranged efficiently. Specifically, when the positioning device 30 is placed on the lower die 4 as shown in FIG. 6, the lower die engaging portion 36 engages with the lower die 4 to regulate the position of the positioning device 30 in the horizontal and vertical directions. Therefore, the lower-mold preheating burner 12 positioned by the lower-mold preheating burner positioning portion 50 shown in FIG. 3 is disposed at an appropriate position for preheating the lower mold 4 (see FIG. 4). In addition, the upper die regulating portion 37 of the positioning device 30 engages with the upper die 3 to regulate the distance between the lower die 4 and the upper die 3 at a constant value. Therefore, the upper die preheating burner 11 positioned by the upper die preheating burner positioning portion 40 is disposed at an appropriate position for preheating the upper die 3. For example, as shown in FIG. 7, even if the convex portion 3a of the upper mold 3 is convex downward, the upper mold preheating burner 11 can be positioned in an appropriate position facing the outer wall 3b so as to surround the convex portion 3a, thereby enabling efficient preheating.

[0047] Furthermore, the positioning device 30 regulates the position between the upper mold preheating burner 11 and the lower mold preheating burner 12. This prevents the upper mold preheating burner 11 and the lower mold preheating burner 12 from interfering with each other within the limited space of the cavity portion 2. Also, they can be efficiently arranged so that the flames ejected from each burner tip are not directed toward the other burner. Therefore, a sufficient preheating effect can be obtained with a small amount of air-fuel mixture, and a cast product of good quality can be obtained in a short time from the first casting without the need for waste casting.

[0048] As shown in FIG. 1, the upper mold 3 is provided with a convex portion 3a that forms the product shape, and the lower mold 4 is provided with a concave portion 4a that accommodates the convex portion 3a. The upper mold preheating burner 11 has an upper mold piping 11c (see FIG. 4) that surrounds at least three of the multiple outer peripheral walls 3b formed on the convex portion 3a, a first row burner tip 11a and a second row burner tip 11b that eject flames from the upper mold piping 11c toward at least two of the outer peripheral walls 3b, and a piping branch portion 23 to which a mold piping 22 that supplies a mixture to the upper mold piping 11c is connected. The positioning device 30 has a base end pipe holding portion 42 that positions and holds the pipe branch portion 23, and a tip end pipe holding portion 44 that holds the upper mold pipe 11c at a position spaced apart from the pipe branch portion 23.

[0049] The piping branching section 23 is stably positioned and held by the base end side piping holder 42, and the straight pipe 11f of the upper die piping 11c is stably positioned and held by the tip end side piping holder 44 at a position near the tip end separated from the piping branching section 23. Therefore, the upper die preheating burner 11 can uniformly and quickly preheat from an appropriate position with good thermal efficiency without bringing the flame into contact with the surface of the upper die 3. In addition, even if the convex portion 3a is convex downward, the upper die preheating burners 11 can be disposed at appropriate positions so as to surround the convex portion 3a. Therefore, by efficiently preheating the corners or recessed corners of the convex portion 3a, which are difficult to preheat due to their uneven shape, it becomes possible to suppress hardening of the molten metal and improve the fluidity.

[0050] The mold preheating device 10 further includes a melting furnace 5 provided below the lower mold 4, and a molten metal supply passage 6 that supplies the molten metal in the melting furnace 5 to the cavity portion 2. The lower mold 4 is provided with a plurality of gates 14 that communicate with the molten metal supply passage 6, and the molten metal supply passage 6 is provided with an intermediate stalk 15 that distributes the molten metal to the plurality of gates 14. The mold preheating device 10 is further provided with a burner 13 for preheating the intermediate stalk. Furthermore, the intermediate stalk preheating burner 13 has a piping for the intermediate stalk 24 located below the upper mold preheating burner 11, a piping branch section 26 for the intermediate stalk that connects the piping for the intermediate stalk 24, and a burner tip 27 for the supply path that is provided on the piping for the intermediate stalk 24 and inserted into the intermediate stalk 15 from the cavity section 2 via the sprue 14. The positioning device 30 is equipped with a vertical holding portion 62 that regulates the vertical position of the supply line burner tip 27 relative to the molten metal supply line 6, and a tilt prevention holding portion 64 that holds the intermediate stalk piping 24 or the intermediate stalk piping branch portion 26 to prevent the intermediate stalk piping 24 from tilting.

[0051] Even if the gate 14 is relatively narrow, the supply passage burner tip 27 is not tilted by the vertical direction holder 62 and the tilt prevention holder 64, and is inserted to the middle position in the molten metal supply passage 6 in the proper vertical direction. Therefore, in the preheating process, the intermediate stalk preheating burner 13 does not interfere with the periphery of the gate 14 and the inner peripheral wall 15a of the intermediate stalk 15, and the supply passage burner tip 27 is held in a position with good preheating efficiency. Therefore, the intermediate stalk 15 provided in the molten metal supply passage 6 is preheated evenly and efficiently from the inside by the flame ejected from the supply passage burner tip 27. For example, the intermediate stalk 15 has a function of temporarily storing the molten metal rising from the melting furnace 5 below through the molten metal supply passage 6 and uniformly filling it toward the cavity portion 2 of the casting mold 1. The intermediate stalk 15 is efficiently preheated by the intermediate stalk preheating burner 13 positioned at an appropriate location, so that the temperature of the intermediate stalk 15 is raised early, enabling the molten metal to pass through it smoothly.

[0052] 4, the lower-mold preheating burner 12 has a lower-mold piping 12b branched downward from the piping branching portion 23 of the upper-mold preheating burner 11, which extends horizontally to a middle position in the space of the cavity portion 2 of the lower mold 4, and a tip 12c is bent downward to form a crank shape. The lower-mold preheating burner 12 is connected to the tip 12c of the lower-mold piping 12b, and has a burner tip assembly 12a where a plurality of burner tips are assembled. The lower die preheating burner positioning portion 50 has a lower die piping holding portion 52 that holds the piping branch portion 23 .

[0053] As shown in Fig. 1, the lower mold 4 is connected to a melting furnace 5 at its bottom, and is also affected by the preheating of the intermediate stalk 15, so that the temperature rises easily. For this reason, by arranging a burner tip assembly 12a at a central position in the space within the cavity portion 2 of the lower mold 4 and adjusting the firepower, the cavity portion 2 can be preheated evenly. The burner tip assembly 12a is inserted at a central position in the cavity portion 2 so that it is spaced a predetermined distance from the side walls 4b located on both sides, with multiple burner tips assembled on the side so that the inner walls, such as the side walls 4b of the slide mold portion 7, can be preheated evenly. At this time, the piping branching portion 23 is held from below by the lower die piping holding portion 52 of the lower die preheating burner positioning portion 50 and accurately positioned. This makes it easy to adjust the flame power so that it is uniform.

[0054] Furthermore, the upper die 3 is provided with a plurality of engaging portions (guide posts) 3j, and the outer periphery of the lower die 4 is provided with a plurality of engaged portions (guide portions) 4j that guide the upper die 3 when the die is opened and closed. The lower die engaging portions 36 engage with the engaged portions 4j, and the upper die regulating portions 37 engage with the engaging portions 3j in a state in which the lower die engaging portions 36 are engaged with the engaged portions 4j. Therefore, by utilizing the plurality of engaging portions 3j and engaged portions 4j used when the die is closed, the positioning accuracy can be further improved.

[0055] The positioning device 30 shown in Fig. 7 is placed between the upper die 3 and the lower die 4 to support the die preheating device 10 (see Figs. 3 and 4). The positioning device 30 has a lower die engaging portion 36 that engages with the lower die 4, an upper die regulating portion 37 that engages with the upper die 3 to regulate the relative position of the upper die 3 with respect to the lower die 4, an upper die preheating burner positioning portion 40 that positions the position of the upper die preheating burner 11 provided in the die preheating device 10 with respect to the upper die 3, and a lower die preheating burner positioning portion 50 that positions the position of the lower die preheating burner 12 provided in the die preheating device 10 with respect to the lower die 4.

[0056] In addition, the positioning device 30 has a vertical holding portion 62 that regulates the vertical position of the intermediate stalk preheating burner 13 provided in the mold preheating device 10, and a tilt prevention holding portion 64 that prevents the intermediate stalk preheating burner 13 from tilting. This allows the positioning device 30 to efficiently position multiple burner tips, which in turn provides practically beneficial effects such as a sufficient preheating effect with even less air-fuel mixture and a high-quality casting product can be obtained in a short time from the first casting without the need for waste casting.

[0057] The present invention is not limited to the above-described embodiment, and various modifications are possible. The above-described embodiment is exemplified to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to delete a part of the configuration of each embodiment, or to add or replace other configurations. Possible modifications of the above-described embodiment are, for example, as follows.

[0058] The positioning device 30 of this embodiment includes a middle stalk preheating burner positioning portion 60. However, this is not particularly limited. For example, the middle stalk preheating burner positioning portion 60 may not be present. Furthermore, the shapes, numbers, and materials of the upper mold preheating burner positioning portion 40, the lower mold preheating burner positioning portion 50, and the middle stalk preheating burner positioning portion 60 are not particularly limited.

[0059] Furthermore, in the positioning device 30, the upper die regulating parts 37 are formed at three points and the lower die engaging parts 36 are formed at two points, but this is not particularly limited. In other words, the shape, number and material of the upper die regulating parts 37 or the lower die engaging parts 36 are not particularly limited. [Explanation of symbols]

[0060] 1 Casting mold 2 Cavity 3 Upper mold 4 Lower mold 11 Upper mold preheating burner 12 Lower mold preheating burner 36 Lower die engagement part 37 Upper die control section 40 Upper mold preheating burner positioning part 50 Lower die preheating burner positioning part

Claims

1. a casting die for supplying molten metal into a cavity formed by an upper die and a lower die to obtain a casting product; A mold preheating device for preheating the casting mold; a positioning device disposed between the upper mold and the lower mold and supporting the mold preheating device; A mold preheating system comprising: The mold preheating device includes an upper mold preheating burner for preheating the upper mold and a lower mold preheating burner for preheating the lower mold, The positioning device includes: A lower die engagement portion that engages with the lower die; an upper die regulating portion that engages with the upper die to regulate a relative position of the upper die with respect to the lower die; an upper mold preheating burner positioning portion that positions the upper mold preheating burner relative to the upper mold; a lower die preheating burner positioning portion for positioning the lower die preheating burner relative to the lower die, The upper die is provided with a convex portion that forms a product shape, the lower mold is provided with a recessed portion in which the protruding portion is accommodated, the upper mold preheating burner has an upper mold pipe surrounding at least three outer peripheral walls among the multiple outer peripheral walls formed on the convex portion, a burner tip that ejects a flame from the upper mold pipe toward at least two outer peripheral walls, and a pipe branching portion that connects a mold pipe that supplies a mixture to the upper mold pipe, the upper mold preheating burner positioning portion has a base end side pipe holding portion that positions and holds the pipe branching portion, and a tip end side pipe holding portion that holds the upper mold pipe at a position separated from the pipe branching portion, The base end side pipe holding portion has a rear long plate protruding upward, and a U-shaped branch pipe receiving portion formed at an upper end of the rear long plate and open upward, A mold preheating system characterized in that the tip side piping holding portion has a front long plate protruding upward, and a U-shaped straight pipe receiving portion formed at the upper end of the front long plate and open upward.

2. 2. The mold preheating system according to claim 1, wherein the out-of-plane directions of the rear long plate and the front long plate are offset by 90 degrees from each other.

3. A melting furnace provided below the lower mold; A molten metal supply passage for supplying the molten metal in the melting furnace to the cavity portion, The lower mold has a plurality of gates communicating with the molten metal supply passage, The molten metal supply passage has an intermediate stalk for distributing the molten metal to the plurality of gates; The mold preheating device further includes a middle stalk preheating burner, The intermediate stalk preheating burner includes an intermediate stalk pipe located below the upper mold preheating burner, a intermediate stalk pipe branch portion connecting the intermediate stalk pipe, and a supply path burner tip provided on the intermediate stalk pipe and inserted into the intermediate stalk from the cavity portion through the sprue, The positioning device has a burner positioning portion for intermediate stalk preheating, The mold preheating system according to claim 1 or 2, characterized in that the intermediate stalk preheating burner positioning portion comprises a vertical holding portion that regulates the vertical position of the burner tip for the supply path relative to the molten metal supply path, and a tilt prevention holding portion that holds the intermediate stalk piping or the intermediate stalk piping branch portion to prevent the intermediate stalk piping from tilting.

4. the lower die preheating burner has a crank-shaped lower die pipe that branches downward from the pipe branching portion of the upper die preheating burner and extends horizontally to an intermediate position in the space of the lower die, and has a downwardly bent tip, and a burner tip assembly that is connected to the tip of the lower die pipe and has a plurality of burner tips assembled therein; The positioning device has a burner positioning portion for intermediate stalk preheating, 2. The mold preheating system according to claim 1, wherein the intermediate stalk preheating burner positioning portion has a lower mold piping holding portion that holds the lower mold piping.

5. The upper die is provided with a plurality of guide posts, A plurality of guide portions are provided on an outer periphery of the lower mold to guide the upper mold when the mold is opened or closed, The lower die engagement portion engages with the guide portion, 2. The mold preheating system according to claim 1, wherein the upper mold regulating portion engages with the guide post when the lower mold engaging portion is engaged with the guide portion.

6. A positioning device that is placed between an upper mold and a lower mold and supports a mold preheating device, A lower die engagement portion that engages with the lower die; an upper die regulating portion that engages with the upper die to regulate a relative position of the upper die with respect to the lower die; an upper mold preheating burner positioning unit that positions a position of an upper mold preheating burner provided in the mold preheating device relative to the upper mold; a lower die preheating burner positioning unit that positions a lower die preheating burner provided in the die preheating device relative to the lower die, the upper mold preheating burner positioning portion has a base end side pipe holding portion which positions and holds a pipe branching portion which distributes the mixture to the upper mold pipe of the upper mold preheating burner, and a tip end side pipe holding portion which holds the upper mold pipe at a position separated from the pipe branching portion, The base end side pipe holding portion has a rear long plate protruding upward, and a U-shaped branch pipe receiving portion formed at an upper end of the rear long plate and open upward, A positioning device characterized in that the tip side piping holding portion has a front long plate protruding upward, and a U-shaped straight pipe receiving portion formed at the upper end of the front long plate and open upward.

7. A positioning device that is placed between an upper mold and a lower mold and supports a mold preheating device, A lower die engagement portion that engages with the lower die; an upper die regulating portion that engages with the upper die to regulate a relative position of the upper die with respect to the lower die; an upper mold preheating burner positioning unit that positions a position of an upper mold preheating burner provided in the mold preheating device relative to the upper mold; a lower die preheating burner positioning unit that positions a lower die preheating burner provided in the die preheating device relative to the lower die, The positioning device is characterized by having a vertical holding portion that regulates the vertical position of an intermediate stalk preheating burner provided in the mold preheating device, and a tilt prevention holding portion that prevents the intermediate stalk preheating burner from tilting.

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