Burner chip, and attachment structure thereof

Abstract

To provide a burner chip capable of achieving a longer service life by preventing a burner plate from being baked to an attachment hole, and to provide an attachment structure thereof.SOLUTION: A burner chip 10 comprising: a body part 12 provided with an ignition port 12a on one end side, that is attached to a burner plate 1 used for heating a core die 31 in a freely attaching / detaching manner; and a bolt shaft part 14 provided with an opening 14a at an opening end, that is continuously formed on the other end side of the body part 12 comprises a chip body 11 whose gas passage 11a connected to the opening 14a from the ignition port 12a, an inner diameter part 21 where the bolt shaft part 14 is screwed, and an outer diameter part 24 where a screw part is formed; and comprises a non-ferrous metal adapter part 20 freely attached / detached to an attachment hole 1a provided to the burner plate 1 in an opening manner.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cylindrical burner tip that is detachably attached to a burner plate used for heating a core die, and to an attachment structure thereof. [Background technology]

[0002] As shown in Figures 9(a) and (b), in this type of conventional burner tip, a burner tip 103 is directly screwed into a mounting hole 102 provided in a burner plate 101 (see, for example, Patent Document 1). Typically, a plurality of mounting holes 102 are provided in the burner plate 101, and by adjusting the number and positions of the mounting holes used for ignition and the mounting holes 102 to be blocked with plugs (not shown in Figure 9), it is possible to adjust the flame power according to the type of core die (not shown in Figure 9).

[0003] The burner tip 103 includes a main body 103a having an ignition port 103d, and a bolt shank 103b connected to the main body 103a and having an opening 103e at its open end. The main body 103a and the bolt shank 103b communicate with each other, forming a gas flow passage 103c inside. A press-in member 104 having a plurality of gas vent holes 104a is attached inside the main body 103a. The two-dot chain line with arrows in the figure indicates the flow of gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 2997420 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, most conventional burner tips are made of iron, and in this case, the burner plate is also made of iron, so when the iron pieces are screwed together at high temperatures of nearly 300°C, the problem of seizing (galling) occurs. To prevent this, there is a method of applying a seizing prevention agent such as molybdenum or fluorine to prevent direct contact between the iron pieces, but the effect of this agent decreases with repeated use, so it is necessary to continue applying it. If the burner tip is made of stainless steel, the rust problem can be solved, but stainless steel and iron can also seize. When this seizing occurs, the burner tip that is screwed into the mounting hole of the burner plate becomes bonded, and in the worst case, the burner tip cannot be removed from the mounting hole, and the burner plate, which does not actually need to be replaced, must be replaced with a new one.

[0006] The present invention has been proposed in consideration of the above circumstances, and its object is to provide a burner tip and its mounting structure that can prevent burning into the mounting hole of the burner plate and thereby extend its life. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the burner tip of the present invention is a cylindrical burner tip that can be attached and detached to a burner plate used to heat a core mold, and is characterized in that it comprises a main body portion having an ignition port at one end, a bolt shank portion connected to the other end side of the main body portion and having an opening at an open end, a tip body in which a gas flow path is formed leading from the ignition port to the opening, and an adapter portion made of a non-ferrous metal that has an inner diameter portion into which the bolt shank portion is screwed and an outer diameter portion formed with a threaded portion, and is attached and detached to a mounting hole opened in the burner plate. Effect of the Invention

[0008] Since the present invention has the above-mentioned configuration, it is possible to suppress seizure of the burner plate to the mounting hole and to achieve a longer life. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a schematic explanatory diagram of a core die heating device showing the use state of a burner plate equipped with a burner tip according to an embodiment of the present invention. [Diagram 2] FIG. 2(a) is a perspective view of the front surface side of a burner plate, and FIG. 2(b) is a perspective view showing the inside (rear surface side) of the same burner plate. [Diagram 3] FIG. 2 is an explanatory diagram of a burner tip, in which (a) is a perspective view of a tip body which is a constituent member of the burner tip, and (b) is a perspective view of the adapter part of the same. [Figure 4] FIG. 1(a) is a front view of the tip body, and (b) and (c) are perspective views of two types of embolisms having different shapes. [Diagram 5] 13(a) and (b) are perspective views showing two examples of burner tip installation procedures, (c) is a perspective view showing an example of a removal procedure, and (d) is a perspective view showing the attached state of the embolism. [Figure 6] FIG. 2 is a vertical cross-sectional view showing the attached state of the burner tip. [Figure 7] 11A and 11B are explanatory views of a burner tip according to another embodiment, in which (a) is a perspective view of a tip body which is a constituent member of the burner tip, and (b) is a perspective view of an adapter part of the same. [Figure 8] 8(a) to 8(c) are schematic plan views illustrating an outline of a procedure for attaching the burner tip shown in FIG. [Figure 9] 1A is a partial perspective view showing a mounting state of a burner tip according to the related art, and FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. A burner tip 10 according to this embodiment is used in a core manufacturing device 30 for a core 5 for forming a hollow portion of a casting (not shown), and more specifically, is attached to a heating burner plate 1 used in the core manufacturing device 30 (shell machine).

[0011] First, the basic configuration of the burner tip 10 according to this embodiment will be described. The burner tip 10 is a cylindrical tip material that is detachably attached to the burner plate 1 used to heat the core die 31, and is composed of two members, a tip body 11 and an adapter part 20. The tip body 11 of the burner tip 10 has a main body part 12 having an ignition port 12a at one end, and a bolt shank part 14 that is connected to the other end side of the main body part 12 and has an opening 14a at the open end. A gas flow path 11a that leads from the ignition port 12a to the opening 14a is formed in the tip body 11. The adapter part 20 of the burner tip 10 has an inner diameter part 21 into which the bolt shank part 14 is screwed and an outer diameter part 24 in which a thread part is formed, and is detachably attached to the mounting hole 1a opened in the burner plate 1.

[0012] Next, the detailed configuration of the burner tip 10 and the mounting structure of the burner tip 10 to the burner plate 1 will be described in further detail with reference to Figs.

[0013] First, we will explain the core manufacturing equipment 30 that uses the burner plate 1. Figure 1 is a schematic explanatory diagram of the core manufacturing equipment 30 to which the burner plate 1 equipped with a burner tip 10 is attached. The core manufacturing equipment 30 is an apparatus that manufactures a core 5 by filling a core mold 31 with molding sand (resin-coated sand) and firing it.

[0014] The core manufacturing equipment 30 is composed of two separate molding machines 30A, a fixed side (left side in the figure) and a movable side (right side in the figure). The fixed side and the movable side are paired, and a core die 31 is disposed on each of the fixed side and the movable side, which are joined together to form the core 5. A cylinder device (not shown) is connected to the movable side, and the two core dies 31 are joined together by operating the cylinder device.

[0015] The core 5 shown in the center of Figure 1 is the core 5 to be manufactured. The core 5 is a mold for forming the hollow portion of the final product, a hollow casting (not shown), and it has various shapes according to the shape of the hollow portion. The core 5 in the example shown is substantially rectangular parallelepiped. A plurality of protrusions 6 are formed on each of the two side surfaces of the core 5 as the core 5 is molded.

[0016] The molding machine 30A includes a core die 31, a die base plate 32 to which the rear part of the core die 31 is fixed, a die mounting frame 33 to which an end part of the die base plate 32 is fixed from behind, and a base plate 34 to which the rear part of the die mounting frame 33 is fixed. The molding machine 30A further includes, in a space 36 surrounded by the die base plate 32, the die mounting frame 33, and the base plate 34, an extrusion plate 37 to extrude the core die 31, and a burner plate 1 connected to the rear side of the extrusion plate 37 with a gap therebetween.

[0017] A plate push-out rod 35 is connected to the burner plate 1 so as to pass through the base plate 34, and a push-out pin 38 facing forward is fixed to the push-out plate 37. The burner plate 1 is pushed out by the pushing action of the plate push-out rod 35, and at the same time, the push-out plate 37 and the push-out pin 38 are pushed forward.

[0018] This ejection pin 38 has the role of pressing the protrusion 6 formed on the side of the molded core 5 through the core die 31, and this ejection action causes the molded product, that is, the core 5, to be removed from the core die 31 and taken out.

[0019] Furthermore, one end of a return pin 39 is fixed to the push-out plate 37, and the other end of the return pin 39 protruding from the joint surface of the core die 31 by the pushing operation comes into contact with the joint surface of the opposing core die 31 when the core die 31 (fixed die 31A, movable die 31B) are joined to each other by a cylinder device (not shown), and is pushed back, returning the push-out plate 37 to its original position. Note that the return pin 39 may be provided with a spring that assists in pushing back the push-out plate 37.

[0020] A plurality of burner tips 10 for heating the core die 31 from behind with a flame F are attached in a dotted manner on the burner plate 1, and the burner tips 10 are replaced according to the shape and configuration of the core die 31. Specifically, when the core die 31 is changed, the position of the ejection pin 38 provided on the core die 31 changes. Therefore, in accordance with the position of the ejection pin 38, a plug 8 is attached to the mounting hole 1a arranged at the position where the ejection pin 38 is provided, and a burner tip 10 is attached to the mounting hole 1a arranged at the position where the ejection pin 38 is not provided. When manufacturing the core 5, it is necessary to ignite the burner tip 10 and heat the core die 31 to a high temperature of 300 degrees, so the burner tip 10 is required to be easily attached and detached, while being fire-resistant enough to withstand a harsh high-temperature environment and having a configuration that does not cause burning.

[0021] 2(a) and (b), a plurality of mounting holes 1a for mounting burner tips 10 are provided on the surface of burner plate 1. Mounting holes 1a communicate with gas supply passage 1b provided inside burner plate 1. In addition, gas supply port 1c is provided on the side of burner plate 1. Burner tips 10 can be attached and detached to the plurality of mounting holes 1a of burner plate 1.

[0022] Next, detailed configurations of multiple types of burner tips 10 and plugs 8 will be described. Fig. 3 is an exploded perspective view showing an example of the burner tip 10. Fig. 4(a) is a front view showing an example of a tip body 11 used in the burner tip 10. Figs. 4(b) and (c) are perspective views showing two examples of the plugs 8.

[0023] As described above, the burner tip 10 is formed by combining the tip body 11 and the adapter part 20, which are separate from each other, in a freely separable manner. The tip body 11 includes a main body part 12 and a bolt shaft part 14, and is preferably made entirely of stainless steel. On the other hand, the adapter part 20 is made of a material different from the tip body 11 to prevent seizure. Specifically, if the tip body 11 is made of stainless steel or iron, the adapter part 20 is made of a non-ferrous metal such as brass. If the tip body 11 is made of stainless steel, the tip body 11 can be made of a long-lasting tip body 11 that is highly fire-resistant and wear-resistant and does not rust easily. The adapter part 20 is not particularly limited as long as it is made of a non-ferrous metal, and may be brass, copper alloy, aluminum alloy, fire-resistant synthetic resin, ceramic, etc. For example, if the adapter part 20 is made of brass, it can be manufactured more cheaply than stainless steel and is easy to process, so that it is easy to mass-produce a product with good precision. Brass is also suitable for the adapter part 20 because it does not rust easily and has fire resistance, although not as much as stainless steel. Furthermore, by making the adapter part 20 out of a non-ferrous metal such as brass, it is not only difficult for the adapter part 20 to burn with the tip body 11, but also difficult for the adapter part 20 to burn into the mounting hole 1a by making the burner plate 1 and the adapter part 20 out of materials other than iron, and the mounting hole 1a is less likely to be damaged. Therefore, according to the burner tip 10 of this embodiment, not only the life of the burner tip 10 but also the life of the burner plate 1 can be extended.

[0024] Conventional burner tips were consumables that had to be replaced when used under high heat and deteriorated, but in this embodiment, the adapter part 20 that is directly attached to the mounting hole 1a of the burner plate 1 is made of non-ferrous metal such as brass, and the tip body 11 with the ignition port 12a is made of highly fire-resistant stainless steel or iron, making it possible to replace only the adapter part 20, for example, because it is severely damaged. Also, depending on the arrangement of the burner tips 10, there are places that are prone to severe damage, so it becomes possible to replace only the adapter part 20 or tip body 11 there with a new one.

[0025] As shown in Fig. 6 etc., the main body 12 of the tip body 11 is a hollow body having an ignition port 12a, and a press-in member 18 having a gas vent hole 18a is press-fitted and attached in a freely detachable manner in the hollow portion 12b. The outer shape of the main body 12 is preferably a hexagonal column shape for ease of operation, but may be other shapes such as a cylinder. The hollow portion 12b of the main body 12 is a cylindrical space in accordance with the shape of the press-in member 18 to be disposed, but is not limited to this.

[0026] The bolt shank 14 of the tip body 11 has an inner space 14b and a threaded portion formed on the outer surface. The inner space 14b communicates with the hollow portion 12b of the body portion 12 via a gap portion 14c. In other words, a gas flow path 11a including a gas vent hole 18a of the press-in member 18 is formed in the internal space from the opening 14a of the bolt shank 14 to the ignition port 12a of the body portion 12.

[0027] The press-in member 18 includes a disk-shaped substrate 18b disposed on the inner bottom 12c with an insertion opening of the main body 12 of the tip body 11, an adjustment plate 18c having a smaller diameter than the substrate 18b, and a connecting shaft 18d connecting the substrate 18b and the adjustment plate 18c at the center, and is formed in an "E" shape in cross section. As the gas vent holes 18a, a main gas vent hole 18aa is formed in the connecting shaft 18d, and a side gas vent hole 18ab is formed in the adjustment plate 18c.

[0028] The gas that flows through the inner space 14b of the bolt shank 14 and the gap 14c of the inner bottom 12c with an insertion opening of the main body 12 is divided and passes through the main gas vent 18aa and the side gas vent 18ab, the gas that passes through the main gas vent 18aa proceeds toward the ignition port 12a, and the gas that passes through the side gas vent 18ab passes through the outer periphery of the adjustment plate 18c and proceeds toward the ignition port 12a. The gas that passes through the main gas vent 18aa and the gas that passes through the side gas vent 18ab join together near the ignition port 12a and reach the ignition port 12a.

[0029] The inner bottom 12c with the insertion opening of the main body 12 is provided with the above-mentioned gap 14c. By providing this gap 14c and providing the adapter 20, even if the diameter dimension Y of the inner space 14b is configured to be smaller than the diameter dimension Y' of the conventional opening 103e (see FIG. 9(b)), the flow of gas through the side gas vent 18ab is not hindered, and a high output of heat can be supplied to the core die 31. In addition, in the development of the burner tip 10 equipped with the adapter 20, the components of the core manufacturing device 30 and the burner plate 1 were required to be configured with the height dimension of the tip body 11 itself being as unchanged as possible from the conventional product in order to use the conventional products in the same manner as before. Therefore, by forming the gap 14c, which is a narrow space, at a position that does not hinder the flow of gas through the side gas vent 18ab, the difference between the height dimension X of the main body 12 and the height dimension X' of the main body 103a of the conventional product could be suppressed to about 5 mm.

[0030] 3 and 4(a), the outer diameter of main body 12 in tip body 11 is larger than the outer diameter of bolt shank 14. Tip body 11 is attached to mounting hole 1a of burner plate 1 via adapter portion 20, so tip body 11 can be formed so that the inner diameter of adapter portion 20 and the outer diameter of bolt shank 14 match.

[0031] Specifically, since the burner plate 1 is used in combination with the burner tip 10 and the plug 8, if it is assumed that a general-purpose plug 8 (for example, one with an outer diameter of M8 or PT1 / 4) is used, then it is sufficient to use a burner tip 10 having a matching mounting hole 1a.

[0032] As described above, the adapter part 20 has threads formed inside and outside the cylindrical body, with the inner diameter part 21 being a female thread part into which the bolt shaft part 14 of the tip body 11 is screwed, and the outer diameter part 24 being a male thread part into which the bolt shaft part 14 of the tip body 11 is screwed, and the outer diameter part 24 being a male thread part into which the bolt shaft part 14 of the tip body 11 is screwed. A driver groove 25 is formed on the upper surface of the adapter part 20 (the surface disposed on the front surface side of the burner plate 1).

[0033] Figures 4(b) and (c) are perspective views showing two examples of plug 8. Both are configured to prevent gas from passing through, and have a threaded portion formed on the outer diameter surface. The plug 8 in Figure 4(b) has a head 8a at the top (the portion disposed on the surface side of the burner plate 1), and gas flow is blocked by this head 8a. A driver groove 8b is formed on the surface of the head 8a. The plug 8 in Figure 4(c) has a bottom 8c, and an operating hole 8d for a hexagonal wrench is formed at the top, reaching the inner bottom, and gas flow is blocked by this bottom 8c.

[0034] The plug 8 may be one that is directly attached to the mounting hole 1a of the burner plate 1, or one that is attached via an adapter part 20. The former and latter have different dimensional relationships with other components. The following dimensional relationships (1) and (2) are based on the dimensions of the plug 8, which is a general-purpose product (for example, an outer diameter of M8 or PT1 / 4).

[0035] (1) When the plug 8 (outer diameter is PT1 / 4) is directly attached Inner diameter of mounting hole 1a, outer diameter of adapter part 20: 12 mm (matching the outer diameter of plug 8) Inner diameter of adapter portion 20, outer diameter of bolt shaft portion 14: for example, about 6, 7 mm Outer diameter of main body 12: for example, about 14 to 16 mm

[0036] (2) When the plug 8 (outer diameter is M8) is attached via the adapter part 20 Inner diameter of mounting hole 1a, outer diameter of adapter part 20: for example, about 12 mm Inner diameter of adapter part 20, outer diameter of bolt shaft part 14: 8 mm (matching the outer diameter of plug 8) Outer diameter of main body 12: for example, about 14 to 16 mm

[0037] Next, the manner of using the burner tip 10 and the plug 8 will be described with reference to Fig. 5 and Fig. 6. Fig. 5(a)-(c) are perspective views showing the procedure for attaching and detaching the burner tip 10, and Fig. 5(d) is a perspective view showing the attached state of two types of plugs 8. Fig. 6 is a longitudinal cross-sectional view of the essential parts showing the attached state of the burner tip 10.

[0038] As shown in Fig. 5(a), the burner tip 10 can be attached to the mounting hole 1a with the adapter part 20 attached to the tip body 11 as a single unit. Alternatively, as shown in Fig. 5(b), the adapter part 20 can be first attached to the mounting hole 1a, and then the tip body 11 can be attached to the inner diameter part 21 of the already attached adapter part 20.

[0039] When the burner tip 10 is attached to the burner plate 1, as shown in Figure 6, the adapter portion 20 is screwed into the mounting hole 1a of the burner plate 1, and the bolt shaft portion 14 of the tip body 11 is screwed into the inner diameter portion 21 of the adapter portion 20, forming a double screwed relationship.

[0040] 5(c), the burner tip 10 can be removed by removing only the tip body 11 while leaving the adapter part 20 in the mounting hole 1a. Of course, the burner tip 10 may be removed as a single unit.

[0041] As shown in Fig. 5(c), if only the tip body 11 is removed, only the tip body 11 can be replaced with respect to the adapter part 20 remaining on the burner plate 1. Leaving the adapter part 20 in this way makes it convenient, for example, to replace the tip body 11 or to replace a deteriorated tip body 11 with a new tip body 11, and allows the burner tip 10 to be used in the same manner as before. In addition, damage to the mounting hole 1a of the burner plate 1 can be reduced, and from this viewpoint, the life of the burner plate 1 can be extended.

[0042] As shown in Fig. 6, if the bolt shank 14 of the tip body 11 and the inner diameter portion 21 of the adapter portion 20 are formed into a tapered screw shape (see the two-dot chain line in Fig. 6), and the outer diameter portion 24 of the adapter portion 20 and the mounting hole 1a of the burner plate 1 are formed into a normal screw shape that is not tapered screw shape, then the tip body 11 can be easily removed alone when removing the tip body 11. Even if the adapter portion 20 rotates together with the tip body 11 during the removal operation, if the adapter portion 20 that protrudes due to the rotation is held by a tool or the like, the tip body 11 alone can be easily removed.

[0043] In addition, the outer diameter portion 24 of the adapter part 20 and the mounting hole 1a of the burner plate 1 may also have a tapered screw-fit relationship. By making these into a tapered screw-fit, it is possible to prevent the adapter part 20 from passing through the mounting hole 1a of the burner plate 1 when attaching the adapter part 20 to the burner plate 1.

[0044] In addition, when the chip body 11 and the adapter portion 20 are attached to the mounting hole 1a while being integrated as shown in Figure 5(a), if the outer diameter of the main body portion 12 (the distance between the opposing vertices of the regular hexagon) is larger than the outer diameter of the adapter portion 20, i.e., the inner diameter of the mounting hole 1a of the burner plate 1, as shown in Figures 3 and 6, in other words, if the shape and dimensions of the main body portion 12 are such that it cannot be inserted into the mounting hole 1a, then the main body portion 12 can act as a stopper when screwed into the mounting hole 1a, thereby preventing the adapter portion 20 from passing through the mounting hole 1a during the screwing operation.

[0045] Furthermore, if the outer diameter portion 24 of the adapter portion 20 and the mounting hole 1a of the burner plate 1 are in a tapered screw-fit relationship, the inner diameter of the opening of the mounting hole 1a will be larger than the outer diameter of the tip of the adapter portion 20, and the inner diameter of the opening on the upper side of the adapter portion 20 will be larger than the outer diameter of the tip of the bolt shank portion 14 of the tip body 11, so that the opening side can guide the insertion side, making the installation operation easier.

[0046] As described above, the burner tip 10 of this embodiment has an attachment structure that includes a separate adapter part 20 and attaches the tip body 11 to the burner plate 1 via the adapter part 20. Therefore, if the adapter part 20 is left attached to the attachment hole 1a, a replacement tip body 11 can be easily attached.

[0047] Moreover, Fig. 5(d) is a diagram showing the installation state of two types of plugs 8. The plug 8 on the left side of this figure is installed in the mounting hole 1a of the burner plate 1 via an adapter part 20 (see the two-dot chain line). On the other hand, the plug 8 on the right side of this figure is installed directly in the mounting hole 1a of the burner plate 1. The two examples shown in Fig. 5(d) correspond to the plugs 8 shown in Figs. 4(a) and (b).

[0048] If the mounting structure is such that the plug 8 is mounted in the mounting hole 1a via the adapter part 20, the plug 8 and burner plate 1 that have been used in the past cannot be used as is. However, if the burner plate 1 and burner tip 10 are prepared so that the plug 8, which is a general-purpose product, can be used and the inner diameter of the mounting hole 1a of the burner plate 1 matches the outer diameter of the adapter part 20, and the adapter part 20 is left in the mounting hole 1a, it is possible to easily replace the tip body 11 / tip body 11 and the tip body 11 / plug 8.

[0049] Furthermore, if the mounting structure is such that the plug 8 is directly mounted in the mounting hole 1a, the plug 8 and burner plate 1 that have been used in a corresponding manner in the past can be used as a pair as is. If the components are in such a corresponding relationship, the adapter part 20 can be operated without leaving it in the mounting hole 1a when replacing the plug 8. Even if the adapter part 20 remains attached, it is possible to easily remove only the adapter part 20 with a tool, so there is no particular problem. In any case, by preparing the burner tip 10 and burner plate 1 to match the diameter of the plug 8, which is a general-purpose product, the plug 8, which is a general-purpose product, can be used as in the past.

[0050] Next, a burner tip 10 according to another embodiment will be described with reference to FIGS.

[0051] In this burner tip 10, threaded portions 15, 22 having threads formed thereon and unthreaded screw receiving portions 16, 23 having no threads formed thereon are alternately formed along the circumferential direction over substantially the entire axial length of both the bolt shank 14 of the tip body 11 and the inner diameter portion 21 of the adapter portion 20. The threaded portions 15, 22 and the screw receiving portions 16, 23 are each formed linearly without distortion along the axial direction. In the illustrated example, two each of the threaded portions 15, 22 and the screw receiving portions 16, 23 are formed (see Figs. 7 and 8).

[0052] The bolt shank 14 and the inner diameter portion 21 are adapted to slide and engage with each other, with the threaded portions 15, 22 sliding into the mating threaded portions 23, 16, and the threaded portions 16, 23 sliding into the mating threaded portions 22, 15 (see Figures 7 and 8(a)). In other words, the bolt shank 14 is engaged with the inner diameter portion 21 simply by aligning and inserting it, without being screwed into it. When the bolt shank 14 is screwed in from this engaged state (in the example of Fig. 8(a) and Fig. 8(b), it is sufficient to rotate it 90°), the threaded portions 15 and 22 mesh with each other, and the bolt shank 14 and the inner diameter portion 21 are fixed to each other (see Fig. 7 and Fig. 8(b)(c)). Therefore, with this configuration, it can be attached in two steps, "insertion" and "90° rotation", and removed in two steps, "90° rotation" and "removal". In other words, when the tip body 11 is attached and removed while the adapter part 20 is attached to the mounting hole 1a, it can be easily attached and removed without relying on the tapered screw structure, which makes it much easier to replace the burner tip 10. Furthermore, in repeated tests by the inventors, it was confirmed that if the tip body 11 and the adapter part 20 are engaged as shown in Fig. 8(c), the engagement relationship does not loosen and a strong engagement state can be maintained even when used under high heat.

[0053] As mentioned above, the burner tip 10 needs to be replaced according to the shape and configuration of the core die 31, and since this replacement work is very time-consuming, a burner tip that can be simplified has been conventionally demanded. However, since the burner tip needs to be able to withstand harsh environments under high temperatures and be firmly attached to the burner plate, it has been difficult to achieve both ease of attachment and detachment. According to the embodiment of the burner tip 10 shown in Figures 7 and 8, the above-mentioned structure not only allows the burner tip to be separated into the tip body 11 and the adapter part 20, but also makes it possible to eliminate the need for the work of rotating the burner tip 360° multiple times and screwing it in.

[0054] In the above embodiment, a core manufacturing device 30 for making the hollow part of a casting by the shell molding method is shown, and the burner tip 10 and burner plate 1 used therein are described, but the present invention is not limited to the illustrated example, and the split mold structure may be any type, whether vertically or horizontally split. The configuration of the burner plate 1 is also not limited to the illustrated example, and the arrangement of the mounting holes 1a of the burner tip 10, and the shapes and configurations of the burner tip 10, the tip body 11, and the adapter part 20 are also not limited to the illustrated example. [Explanation of symbols]

[0055] 1 burner plate 1a Mounting hole 8 Embolism 10 Burner Tip 11 Tip body 11a Gas flow path 12 Main body 12a ignition port 14 Bolt shank 14a aperture 15 Thread forming part 16 Screw receiving part 20 Adapter part 21 Inner diameter 22 Thread forming part 23 Screw receiving part 24 Outer diameter part 30 Core manufacturing equipment 31 Core mold

Claims

1. A cylindrical burner tip that is detachably attached to a burner plate used to heat a core die, a tip body having a body portion having an ignition port at one end and a bolt shank portion connected to the other end side of the body portion and having an opening at an open end, the tip body having a gas flow passage formed from the ignition port to the opening; A burner tip characterized in that it is equipped with an adapter portion made of a non-ferrous metal having an inner diameter portion into which the bolt shank is screwed and an outer diameter portion having a threaded portion formed thereon, and which is freely attachable and detachable to a mounting hole opened in the burner plate.

2. In claim 1, A burner tip characterized in that the outer dimensions of the main body portion in a plan view are larger than the outer dimensions of the adapter portion in a plan view.

3. In claim 1, A burner tip characterized in that the bolt shank and the inner diameter portion are shaped to have a tapered threaded engagement.

4. In claim 1, A burner tip characterized in that the adapter portion is made of brass.

5. In claim 1, The bolt shank and the inner diameter portion are alternately provided with a threaded portion and a threaded receiving portion not having a threaded portion along a circumferential direction, A burner tip characterized in that the bolt shank and the inner diameter portion are engaged with each other and are axially slidable.

6. A burner tip mounting structure comprising: the burner tip according to any one of claims 1 to 5; and the burner plate.

7. In claim 6, A plug for closing the mounting hole can be attached to the mounting hole, 2. A burner tip mounting structure, comprising: a plug, instead of the tip body, attached to the mounting hole via the adapter.

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