Mold for casting a housing and method for opening and closing the mold

Abstract

The application is a casting mold of a shell mold, comprising a main mold plate with a combined cavity and a combined core held in the combined cavity, the combined cavity comprises a main core cavity formed by inward extension on one side of the main mold plate, a water inlet cavity on one side of the main core cavity and communicated with the main core cavity, and a water outlet cavity on the other side of the main core cavity and arranged opposite to the water inlet cavity and communicated with the main core cavity, the combined core comprises a main core held in the main core cavity, a water inlet core held and inserted in the water inlet cavity and contacted with one side of the main core, and a water outlet core held and inserted in the water outlet cavity and contacted with the other side of the main core, the combined cavity is closed in the main mold plate in a ring structure, the combined cavity further comprises a core groove arranged between the main core cavity and the water outlet cavity and connecting the main core cavity and the water outlet cavity, and the combined core further comprises an independent core arranged in the core groove.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mold, in particular to a casting mold of a shell mold and a mold opening and closing method thereof. BACKGROUND

[0002] The existing production process of the shell mainly includes: two half type wax blank bonding assembly one forming of investment casting and parting after forging / stamping and then welding forming.

[0003] When the two half type wax blank process is adopted, the shell needs to be divided into two halves to complete the wax blank, and then fixed and assembled by using an adhesive. During the assembly process of the two half wax blanks, the shell is prone to deformation, misplacement and internal cavity gap, and the bonding is prone to be out of position, resulting in casting defects such as shell inclusion and shrinkage.

[0004] When the steel plate parting welding process is adopted, the shell is formed by welding each part. The product size precision error is large; the welding marks need to be polished; the welding seam is prone to pores, slag inclusion, cracks and incomplete welding at the welding root; and the crystal organization of the welding position changes, resulting in reduced corrosion resistance and mechanical properties of the product.

[0005] Therefore, the existing two half type wax blank process and the steel plate parting welding process cannot guarantee the quality of the shell.

[0006] Meanwhile, the shell belongs to a complex structure product. From the perspective of casting, the complex structure inevitably leads to uneven wall thickness, which causes more casting problems and difficulties due to the obstruction of the flow of stainless steel liquid in the mold cavity. In addition, uneven wall thickness of the product increases the single weight of the product and increases the cost. Therefore, from the perspective of production efficiency and production cost, local weight reduction design is needed to ensure the uniformity of the wall thickness of the product and to reduce the single weight of the product as much as possible. Since the shell is formed by one-time casting, the casting process is as follows: first, inject paraffin into a closed casting mold to form a wax mold with a 1:1 ratio of the shell; and then cast a stainless steel shell. In order to design the shell with uniform wall thickness and weight reduction, the shell mold should also be designed with weight reduction structure. When the stainless steel shell with local weight reduction structure is cast, in order to design the core to match the weight reduction structure at the special position, the reasonable structure of the core at the weight reduction position needs to be considered to facilitate the assembly and demolding of the core.

[0007] Therefore, it is necessary to provide a new casting mold of a shell mold and a method thereof to overcome the above-mentioned defects. SUMMARY

[0008] The present application relates to the technical field of mold, in particular to a casting mold of a shell mold and a mold opening and closing method thereof.

[0009] The purpose of the present application is achieved by the following technical solution one: a casting mold (1000) of a shell mold, comprising a main mold plate (200) with a combined cavity and a combined core (100) clamped in the combined cavity, the combined cavity comprises a main core cavity (203) formed by extending inward on one side of the main mold plate (200), a water inlet cavity (204) located on one side of the main core cavity (203) and communicating with the main core cavity (203), and a water outlet cavity (205) located on the other side of the main core cavity (203) and opposite to the water inlet cavity (204) and communicating with the main core cavity (203), the combined core (100) comprises a main core (1) clamped in the main core cavity (203), a water inlet core (2) clamped and inserted in the water inlet cavity (204) and contacting one side of the main core (1), and a water outlet core (3) clamped and inserted in the water outlet cavity (205) and contacting the other side of the main core (1), the combined cavity further comprises a core groove (2064) provided between the main core cavity (203) and the water outlet cavity (205) and connecting and transitioning the main core cavity (203) and the water outlet cavity (205), and the combined core (100) further comprises an independent core (7) provided in the core groove (2064).

[0010] Further, the combined cavity of the main mold plate (200) further comprises a check port cavity (206) located between the main core cavity (203) and the water outlet cavity (205) and communicating with the core groove (2064), and the combined core (100) further comprises a check port core (4) clamped in the check port cavity (206) and contacting one side of the main core (1).

[0011] Further, the check port cavity (206) communicates with the water outlet cavity (205) and is opposite to the core groove (2064), and the cross-sectional width of the independent core (7) perpendicular to the axial direction of the check port cavity (206) is adapted to the radial width of the check port core (4).

[0012] Further, the independent core (7) is a wedge-shaped structure, and the independent core (7) is made of special silica gel.

[0013] Further, the hardness of the independent core (7) is 26 to 29.

[0014] Further, the main core (1) comprises a water outlet contact portion (52) inclined downward from one side of the main core (1) and contacting the independent core (7), and the independent core (7) is attached to the bottom surface of the side of the water outlet contact portion (52) facing the water inlet core (2).

[0015] Further, the check valve core (4) is provided with a second groove along the axial direction of the check valve cavity (206), the water outlet contact part (52) is provided with a through hole, the independent core (7) is provided with a second convex ring part, the check valve core (4) passes through the through hole and makes the second groove cooperate with the second convex ring part.

[0016] Further, the main core (1) comprises a mounting part (12) and a step part (13) fixed in the main core cavity (203), the step part (13) comprises a first base (131) and a second base (132) extending downward from the first base (131), and the combined core (100) further comprises a rubber sleeve core sleeved on the main core (1), which is made of silica gel.

[0017] Further, the hardness of the rubber sleeve core ranges from 20 to 25 and 35 to 37.

[0018] Further, the water outlet contact part (52) is integrally formed with the rubber sleeve core and is made of the same material.

[0019] Further, the rubber sleeve core comprises an upper ring chamber rubber sleeve (5) sleeved on the first base (131) and a lower ring chamber rubber sleeve (6) sleeved on the second base (132), and the water outlet contact part (52) extends downward from the part of the upper ring chamber rubber sleeve (5) sleeved on the main core (1) to one end of the core groove (2064) in a slanting manner.

[0020] Further, the lower ring chamber rubber sleeve (6) extends upward in a slanting manner on the side opposite to the water outlet contact part (52) to form a water inlet contact part (62) in contact with one end of the water inlet core (2).

[0021] Further, the check valve core (4) is further provided with a first groove parallel to the second groove along the axial direction of the check valve cavity (206), the water outlet contact part (52) is provided with a first convex ring part in the through hole, and the first groove and the first convex ring part are fixedly matched.

[0022] Further, the size of the part of the combined core (100) exposed outside the main body template (200) is greater than the size of the part of the combined core (100) located inside the main body template (200), the cross section of the part of the combined core (100) exposed outside the main body template (200) is substantially circular or rectangular, and the cross section of the part of the combined core (100) exposed outside the main body template (200) is attached to the end face outside the main body template (200).

[0023] The purpose of the present application is realized by the following technical scheme two: a mold closing method of the casting mold of the shell mold, comprising the following steps:

[0024] The upper ring chamber rubber sleeve (5) is sleeved on the first base (131) of the main core (1), and the lower ring chamber rubber sleeve (6) is sleeved on the second base (132) of the main core (1), and the main core (1) is loaded into the main core chamber (203);

[0025] The independent core (7) is loaded at the bottom of the check core (4), and then the check core (4) is loaded into the check core cavity (206), and the independent core (7) is located in the core groove (2064) so that the check core (4) is arranged to the accurate position;

[0026] The water outlet core (3) is loaded into the water outlet cavity (205), so that one side of the water outlet core (3) abuts against the check core (4);

[0027] The water inlet core (2) is loaded into the water inlet cavity (204);

[0028] The upper and lower covers of the main body template (200) are closed, and the mold closing assembly of the casting mold of the shell mold is completed.

[0029] The purpose of the present application is realized by the following technical scheme three: a mold opening method of the casting mold of the shell mold, comprising the following steps:

[0030] The main body template (200) is separated from top to bottom;

[0031] The water inlet core (2) is extracted;

[0032] The water outlet core (3) is extracted in two parts;

[0033] The main core (1) is extracted, at this time, the upper ring chamber rubber sleeve (5) and the lower ring chamber rubber sleeve (6) sleeved on the first base (131) and the second base (132) lose support;

[0034] The check core (4) is extracted;

[0035] The upper ring chamber rubber sleeve (5), the lower ring chamber rubber sleeve (6) and the independent core (7) are clamped out of the check core cavity (206).

[0036] In the casting mold of the shell mold of the present application, when the mold core is used to make the wax blank, the connecting transition groove (2064) with a triangular cross section is arranged between the main core cavity (203) and the water outlet cavity (205), the combined core (100) further comprises an independent core (7) arranged in the connecting transition groove (2064), the independent core 7 is a wedge-shaped rubber pad, which is attached to the bottom of the water outlet contact part 52 of the upper ring chamber rubber sleeve 5, and plays a role in occupying the space to manufacture the wax mold cavity, ensure uniform wall thickness and reduce the product weight. The wedge-shaped rubber pad is attached to the bottom of the water outlet contact part of the upper ring chamber rubber sleeve 5, embedded in the mold, and plays a role in occupying the space during the wax injection process. After the wax type is solidified, the wedge-shaped rubber pad is clamped out through the check valve by using tweezers and other tools during the core pulling process, so as to manufacture the wax mold cavity and ensure the purpose of reducing weight and uniform wall thickness. And the casting mold of the shell mold can obtain a complete wax blank, and the shell of the water meter is not easy to appear deformation, misplacement, inclusion, shrinkage and other casting defects when the complete wax blank is used for casting. At the same time, the combined core for producing the shell of the water meter does not need to be split welded, and the welding seam does not appear, so as to ensure the product quality of the shell of the water meter. And the casting mold of the shell mold can make the wax blank one-time forming, reduce the wax blank manufacturing link, improve the production efficiency of the wax blank, and further improve the production efficiency of the shell of the water meter. BRIEF DESCRIPTION OF DRAWINGS

[0037] Figure 1 It is a perspective view of the casting mold of the shell mold of the first embodiment of the present application.

[0038] Figure 2 It is a perspective exploded view of the casting mold of the shell mold of the first embodiment of the present application.

[0039] Figure 3 It is a perspective view of the lower mold plate in the casting mold of the shell mold of the first embodiment of the present application.

[0040] Figure 4 It is a front view when the combined core is separated in the first embodiment of the present application.

[0041] Figure 5 It is a perspective view of part of the combined core in the first embodiment of the present application.

[0042] Figure 6 It is a sectional view when the combined core is inserted into the main mold plate in the first embodiment of the present application.

[0043] Figure 7 It is a perspective view of the shell manufactured by the casting mold of the shell mold.

[0044] Figure 8 A sectional view of a housing manufactured for a casting mold of a housing mold.

[0045] Figure 9 A perspective view of a casting mold of a housing mold in the second embodiment.

[0046] Figure 10 A perspective exploded view of a casting mold of a housing mold in the second embodiment.

[0047] Figure 11 An enlarged view of a lower mold plate in Figure 10

[0048] Figure 12 A front view of a combined core assembly in the second embodiment.

[0049] Figure 13 A top view of a main core separated from other combined cores in the second embodiment.

[0050] Figure 14 A sectional view of a combined core held to the main mold plate in the second embodiment.

[0051] Figure 15 A perspective exploded view of a combined core in the second embodiment.

[0052] Figure 16 An exploded view of a main core side block of a main core in the second embodiment.

[0053] Figure 17 A combined view and exploded view of a check port core and a core in the second embodiment.

[0054] Figure 18 A perspective exploded view of a combined core in the second embodiment. DETAILED DESCRIPTION

[0055] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0056] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting" should be understood broadly, and those skilled in the art can understand the specific meanings of the above terms in the present application according to the specific circumstances.

[0057] ​In the precision investment casting industry, to make qualified castings, first of all, a qualified mold needs to be made, and then a mold shell (mold layer) can be made by using a wax mold to cast, forming a casting. The casting in the present application is a shell. The shell is a relatively complex cast structure product, including a water inlet, a water outlet and a middle ring chamber. Due to the variability of the overall structure, when stainless steel is cast, it is likely to cause problems such as uneven thickness. The impact of uneven wall thickness of stainless steel products is not only the difficulty of cost control, but also causes problems such as gas holes and flow obstruction during the flow of stainless steel liquid, thereby resulting in substandard product quality. Therefore, it is necessary to maintain the uniform wall thickness of the stainless steel product. Under the premise of maintaining the uniform wall thickness, the water outlet is located in the area connecting the middle ring chamber and the water outlet, and is located at the position of the upper ring chamber drainage flow. A triangular stainless steel area with extremely thick wall thickness is formed at the outlet of the cavity. The wall thickness at this position not only increases the cost, but also easily causes casting defects. Therefore, the wall thickness at this position must be optimized, and the weight reduction structure is generated. The wall thickness of the weight reduction water table shell at this weight reduction structure is basically the same as the wall thickness of other parts of the weight reduction water table shell, so as to reduce the thermal fatigue caused by local heat concentration of the mold cavity, avoid the generation of hot spots during steel casting, and further avoid defects such as deformation, cracks, porosity, cold separation, gas holes and the like of the casting, and ensure the forming quality of the casting.

[0058] Please refer to Figure 7 and Figure 8 , the first embodiment and the second embodiment of the present application are directed to the design of the casting mold forming the weight reduction structure in the casting process of the shell mold. The weight reduction design of the shell mold can adopt two design forms, one is external weight reduction, and the other is internal weight reduction design, and the embodiments of the present application are mainly directed to the design of the casting forming the internal weight reduction of the shell mold. The main difference between the first embodiment and the second embodiment is that the materials of the casting molds forming the weight reduction design are different. The casting material of the first embodiment is a soft material, and the casting mold material of the second embodiment is a hard material.

[0059] In the following, the specific embodiments of the casting mold of the shell mold and the mold opening and closing method thereof will be introduced in combination with Figures 1 to 17 Please refer to Figures 1 to 6 , which is the first embodiment of the present application, Figures 9 to 17 , which is the second embodiment of the present application.

[0060] Please refer to Figure 7 and Figure 8, water meter mold is an integral mold, in the embodiment, the water meter mold is a wax mold of paraffin material, the water meter mold is designed as 1:1 with the stainless steel water meter shell and a finishing allowance is reserved. The water meter shell 400 includes a water inlet channel 401, a water outlet channel 402, a middle ring cavity between the water inlet channel 401 and the water outlet channel 402, a separation part 406 separating the middle ring cavity into an upper ring cavity 403 and a lower ring cavity 404, and a check structure 405. The separation part 406 is used to support the installation of the water meter core. The water inlet channel 401 includes a water inlet end 4011 on one side. The water outlet channel 402 includes a water outlet end 4021 on the other side opposite to the water inlet end 4011. The upper ring cavity 403 is provided with an upper water outlet hole 4031 corresponding to the water outlet channel 402. The lower ring cavity 404 is provided with a lower water inlet hole 4041 communicating with the upper ring cavity 403. The check structure 405 includes a check flow channel 4051 communicating with the upper ring cavity 403 and a check valve cavity 4052 connected to the check flow channel 4051. When the weight-reducing water meter shell 400 is applied, the water flow follows the path of water inlet channel 401-lower ring cavity 404-upper ring cavity 403-check flow channel 4051 of check structure 405-check valve cavity 4052-water outlet channel 402. Among them, the annular separation part 406 for bearing the core is arranged between the upper ring cavity 403 and the lower ring cavity 404, and the check valve cavity 4052 is used to install the check valve for preventing water backflow. At this time, since the water passes through the lower water inlet hole 4041 and the upper water outlet hole 4031, the flow rate drives the rotation of the water meter core. When the water flows to the check structure 405, the inclined check pad is arranged at the check structure 405 to prevent the backflow of water. At the same time, a weight-reducing part 407 is arranged at the water outlet channel 402, which is just in the area connecting the middle ring cavity and the upper water outlet hole 4031 and is at the position of the upper ring cavity 403 discharging water. The weight-reducing part 407 can reduce the weight of the water meter shell 400, increase the production efficiency and reduce the cost. The difference between the first embodiment and the second embodiment is that the size of the weight-reducing part 407 is different. In the first embodiment, the size of the weight-reducing part 407 is large, and in the second embodiment, the size of the weight-reducing part is small.This is because in the first embodiment, the size of the check valve core 4 corresponding to the weight reduction area is large, if the structure of the integrated design of the check valve core 4 is used to occupy the formation of the weight reduction part 407, it will cause the size of the bottom of the check valve core 4 to be too large, and it cannot be pulled out of the check valve hole, therefore, when designing the mold core of the casting wax mold, the independent core 7 is used to form the weight reduction part 407, and the water meter shell mold is formed, and the independent core 7 is taken out from the check valve cavity 4052 of the water meter mold.

[0061] When casting the weight-reduced water meter shell 400, the independent core 7 (core 5') forms the weight reduction part 407, the weight reduction groove 407 is in communication with the check valve flow channel 4051 and is opposite to the outside port of the check valve cavity 4052, so that the independent core 7 (core 5') can enter the check valve flow channel 4051 or the check valve cavity 4052 after being separated from the weight reduction part 407 during demolding, and be taken out from the inner cavity of the water meter shell mold.

[0062] The cross section of the weight reduction part 407 is triangular to adapt to the shape of the excessively thick area. Of course, under the premise of facilitating demolding, the weight reduction part 407 can also be provided in other shapes. The inner wall corners of the weight reduction part 407 are provided with casting fillets to avoid stress caused by sharp corners on the independent core 7 and to avoid thermal nodes in the mold cavity during pouring. The size of the weight reduction part 407 in the direction perpendicular to the axial direction of the check valve flow channel 4051 is smaller than the size of the cross section of the check valve flow channel 4051 in any direction. The specific structure of the shell 400 manufactured by the two embodiments will not be described hereinafter.

[0063] Hereinafter, specific embodiments will be described in conjunction with Figures 1 to 17 .

[0064] Please refer to Figures 1 to 6As shown, the casting mold 1000 of the shell mold includes a main mold plate 200 with a combined cavity and a combined core 100 received and held in the combined cavity. The main mold plate 200 includes an upper mold plate 201 and a lower mold plate 202 fixedly fitted together. The upper mold plate 201 and the lower mold plate 202 are symmetrically arranged and clamped together via a fixing structure. The combined cavity is formed in the interior of the main mold plate 200 as a closed space, which includes a main core cavity 203 formed by inward extension on one side of the main mold plate 200, a water inlet cavity 204 located on one side of the main core cavity 203 and communicating with the main core cavity 203, a water outlet cavity 205 located on the other side of the main core cavity 203 and arranged opposite to the water inlet cavity 204 and communicating with the main core cavity 203, a core groove 2064 connecting and transitioning the main core cavity 203 and the water outlet cavity 205 between the water outlet cavity 205 and the main core cavity 203, a check port cavity 206 communicating with the core groove 2064 between the main core cavity 203 and the water outlet cavity 205, a wax injection hole 207 located on the side of the main mold plate 200 opposite to the main core cavity 203, and a flow guide cavity 208 communicating between the wax injection hole 207 and the combined cavity. The main core cavity 203 is provided with a first opening 2031 located on the end side of the main mold plate 200, a surrounding cavity 2034 adjacent to the first opening 2031 and having a size not greater than that of the first opening 2031, a first positioning ring cavity 2032 adjacent to the surrounding cavity 2034 and having a size greater than that of the first opening 2031, and a second positioning ring cavity 2033 located on the other end of the first positioning ring cavity 2032 and having a size greater than that of the first positioning ring cavity 2032. The water inlet cavity 204 is provided with a second opening 2041 located on the end side of the main mold plate 200, a first base cavity 2042 adjacent to the second opening 2041 and having a size greater than that of the second opening 2041, and a first annular cavity 2043 located inside the first base cavity 2042 and having a size greater than that of the second opening 2041. The water outlet cavity 205 includes a third opening 2051 located on the end side of the main mold plate 200, a second base cavity 2052 adjacent to the third opening 2051 and having a size not greater than that of the third opening 2051, and a second annular cavity 2053 located inside the second base cavity 2052 and having a size greater than that of the third opening 2051. The check port cavity 206 includes a fourth opening 2061 located on the end side of the main mold plate 200, a third base cavity 2062 adjacent to the fourth opening 2061 and having a size not greater than that of the fourth opening 2061, a third annular cavity 2063 located inside the third base cavity 2062 and having a size greater than that of the fourth opening 2061, and the core groove 2064 located inside the third annular cavity 2063.The cross section of the core recess 2064 is triangular to fit the shape of the excess area. The check mouth cavity 206 is formed extending from the core recess 2064 to the outer end side of the main mold plate 200. The check mouth cavity 206 communicates with the water outlet cavity 205 and is disposed opposite to the core recess 2064. In the present embodiment, the core recess 2064 is located at the bottom end of the check mouth cavity 206.

[0065] Please continue to see Figures 1 to 8 The combined core 100 includes the main core 1 held inserted in the main core cavity 203, the water inlet core 2 held inserted in the water inlet cavity 204 and contacting one side of the main core 1, the water outlet core 3 held inserted in the water outlet cavity 205 and contacting the other side of the main core 1, and the check mouth core 4 held inserted in the check mouth cavity 206 and contacting the same side of the main core 1 as the water outlet core 3, and the independent core 7 held inserted in the core recess 2064 and contacting the check mouth core 4.

[0066] The main core 1 includes a head 11 exposed to the end side of the main body mold plate 200 and exposing the first opening 2031, a mounting portion 12 held in the surrounding cavity 2034, and a step portion 13 positioned in the first positioning ring cavity 2032 and the second positioning ring cavity 2033. The radial dimension of the mounting portion 12 is equivalent to that of the surrounding cavity 2034. The step portion 13 includes a first base 131 located in the first positioning ring cavity 2032 and a second base 132 positioned in the second positioning ring cavity 2033. The second base 132 is located at the lower end of the first base 131. The radial dimensions of the first base 131 and the second base 132 are smaller than those of the first positioning ring cavity 2032 and the second positioning ring cavity 2033. The combined core 100 further includes an upper ring chamber rubber sleeve 5 sleeved on the first base 131 and a lower ring chamber rubber sleeve 6 sleeved on the second base 132. The upper ring chamber rubber sleeve 5 and the lower ring chamber rubber sleeve 6 are preferably made of rubber, but can also be made of other materials that can deform, such as polyethylene. The radial dimensions of the first base 131 and the second base 132 after being sleeved with the upper ring chamber rubber sleeve 5 and the lower ring chamber rubber sleeve 6 are still smaller than those of the first positioning ring cavity 2032 and the second positioning ring cavity 2033, and the remaining gaps are filled with paraffin during the wax injection process. The upper ring chamber rubber sleeve 5 includes a first surrounding portion 51 surrounding the first base 131 and a water outlet contact portion 52 obliquely disposed along one side of the first surrounding portion 51 and abutting against the water outlet core 3. The lower ring chamber rubber sleeve 6 includes a second surrounding portion 61 surrounding the second base 132 and a water inlet contact portion 62 disposed along one side of the second surrounding portion 61 and opposite to the water outlet contact portion 52 and abutting against one end of the water inlet core 2. The water outlet contact portion 52 is provided with a through hole (not labeled), and a first protruding ring portion is arranged in the through hole. Due to the arrangement of the upper ring chamber rubber sleeve 5 and the lower ring chamber rubber sleeve 6, the main core 1 provided with the upper ring chamber rubber sleeve 5 and the lower ring chamber rubber sleeve 6 has a structure with a small opening and a large belly. The main core 1 is further provided with an air hole 14 longitudinally penetrating the main core 1. Since the main core cavity 203 is a ring structure, after the ring structure of the combined core is completed and sealed, in the actual wax injection process, the wax with a higher temperature will expand and squeeze the original air, forming a vacuum at the bottom of the ring cavity of the wax mold. In this case, if the main core 1 is forcibly pulled out, a protrusion will be formed at the bottom of the ring cavity of the wax mold, which may cause quality problems or an increase in the single weight during casting, thereby causing losses. In the present application, the rubber sleeve core, i.e., the upper ring chamber rubber sleeve 5 and the lower ring chamber rubber sleeve 6, is sleeved on the main core 1, and the air hole 14 longitudinally penetrating the main core 1 is designed at the center position of the main core 1. Air is injected into the air hole 14 by an air gun to solve the vacuum problem, which is more efficient. The increased air pressure at the bottom will directly lift the main core 1 by a certain distance, making it more convenient and faster to pull out the main core 1.Meanwhile, the part of the combined core 100 exposed to the main mold plate 200 has a size greater than that of the part of the combined core located in the main mold plate 200, the cross section of the part of the combined core 100 exposed to the main mold plate 200 is substantially circular or rectangular, and the cross section of the part of the combined core 100 exposed to the main mold plate 200 is fitted to the end surface outside the main mold plate 200. The radial dimension of the head 11 of the main core 1 is greater than the size of the first opening 2031, which is convenient for the operator to have a recombination base surface when recombining the core, guarantees the work efficiency of the operator, and has a greater force area for the operator to act on, which can increase the work efficiency of the operator. Thirdly, and most importantly, the accurate and rapid positioning of the main core 1 is determined by whether the large circular surface and the exposed edge of the main core cavity 203 are in close contact.

[0067] The water outlet contact part 52 is integrally formed with the rubber sleeve core and is made of the same material. In this embodiment, the water outlet contact part 52 is formed by extending downward from the upper ring chamber rubber sleeve 5.

[0068] The water inlet core 2 is in contact with the main core 1 at one end located in the main mold plate 200, i.e., in contact with the water inlet contact part 62. The water inlet core 2 includes the water inlet fixing part 21 exposed to the second opening 2041 and the first combination part 22 in contact with the water inlet contact part 62. The radial dimension of the water inlet fixing part 21 is greater than the size of the second opening 2041, which has the same effect as the head 11 of the main core 1, i.e., it is convenient for the operator to have a recombination base surface when recombining the core, guarantees the work efficiency of the operator, and has a greater force area for the operator to act on, which can increase the work efficiency of the operator. Thirdly, and most importantly, the accurate and rapid positioning of the water inlet core 2 is determined by whether the cross section of the water inlet fixing part 21 and the exposed edge of the water inlet cavity 204 are in close contact. In addition, the size of the water inlet core 2 located in the main mold plate 200 is smaller than the size of the second opening 2041. The part of the water inlet core 2 located in the first base cavity 2042 has a radial dimension comparable to that of the first base cavity 2042, and the part of the water inlet core 2 located in the first annular cavity 2043 has a radial dimension smaller than that of the first annular cavity 2043, leaving a gap for filling with paraffin during the wax injection process to form part of the wax mold.

[0069] The water outlet core 3 is in contact with the main core 1 at one end of the main body mold plate 200, i.e. in contact with the water outlet contact part 52. The water outlet core 3 comprises a water outlet fixing part 31 exposed to the third opening 2051 and a second joint part 32 in contact with the water outlet contact part 52. The radial dimension of the water outlet fixing part 31 is greater than the dimension of the third opening 2051. It has the same effect as the head part 11 of the main core 1. Firstly, it provides a recombination base for the operator during the core extraction and recombination, which guarantees the work efficiency of the operator. Secondly, it provides a greater force area for the operator during the core extraction, which can increase the work efficiency of the operator. Thirdly, and most importantly, the accurate and rapid positioning of the water outlet core 3 is determined by whether the cutting surface of the water outlet fixing part 31 and the exposed edge of the water outlet cavity 205 are in close contact. Since the dimension of the second joint part 32 is greater than the dimension of the third opening 2051, a structure with a small mouth and a large belly is formed here. The water outlet core 3 at this time comprises a first water outlet core 33 in contact with the check valve core 4 and a second water outlet core 34 for accommodating the water outlet contact part 52 together with the port of the first water outlet core 33. The first water outlet core 33 further comprises a contact part 331 in contact with the check valve core 4. The contact part 331 is used to form the communication position of the check valve cavity 4052 and the water outlet passage 402. The part of the water outlet core 3 located in the second base cavity 2052 has a radial dimension equivalent to that of the second base cavity 2052, and the radial dimension of the part of the water outlet core 3 located in the second annular cavity 2053 is smaller than that of the second annular cavity 2053. The remaining gap is filled with paraffin during the wax injection process to form a part of the wax mold.

[0070] The check valve core 4 is in contact with the main core 1 at one end inside the main body mold plate 200, i.e. in contact with the water outlet contact part 52. The check valve core 4 comprises a check valve fixing part 41 attached to the outer surface of the check valve cavity 206 exposed to the fourth opening 2061 and a third joint part 42 in contact with the water outlet contact part 52. The radial dimension of the check valve fixing part 41 is larger than the size of the fourth opening 2061. It has the same effect as the head part 11 of the main core 1. Firstly, it provides a recombination base for the operator during the core pulling and recombination process, which guarantees the work efficiency of the operator. Secondly, it provides a larger force area for the operator during the core pulling process, which can increase the work efficiency of the operator. Thirdly, and most importantly, the accurate and fast positioning of the check valve core 4 is determined by whether the cutting surface of the check valve fixing part 41 and the exposed edge of the check valve cavity 206 are in close contact. The part of the check valve core 4 inside the main body mold plate 200 has a smaller size than the fourth opening 2061. The part of the check valve core 4 in the third base cavity 2062 has a radial dimension equivalent to that of the third base cavity 2062. The radial dimension of the part of the check valve core 4 in the third annular cavity 2063 is smaller than that of the third annular cavity 2063, leaving a gap for filling with paraffin during the wax injection process to form a part of the wax mold. The third joint part 42 is provided with a first groove (not numbered) and a second groove (not numbered) located on the inner side of the first groove in parallel. The third joint part 42 cooperates with the hole shaft of the water outlet contact part 52 to accurately position the water outlet contact part 52.

[0071] The combined core 100 further comprises the independent core 7 arranged in the core groove 2064. The interface width of the independent core 7 perpendicular to the axial direction along the check valve cavity 206 is greater than the radial width of the check valve core 4. In this embodiment, that is, the interface width of the independent core 7 perpendicular to the axial direction along the check valve cavity 206 is greater than or equal to the radial width of the check valve core 4. In this embodiment, the second groove provided on the check valve core 4 and the second protruding ring part provided at the corresponding position of the independent core 7 are clamped with each other to accurately position the independent core 7 through the check valve core 4. The independent core 7 is a wedge-shaped structure and is not made of specific silica gel, and the hardness is 26-29. The independent core 7 is located at one end of the check valve core 4 inside the main body mold plate 200. The water outlet contact part 52 of the upper ring chamber rubber sleeve 5 is located between the core 7 and the check valve core 4 at one end inside the main body mold plate 200. The independent core 7 is attached to the bottom surface of the side of the water outlet contact part 52 facing the water inlet core 2. The independent core 7 is provided with a pressing surface 71 facing one side of the water inlet core 2, an abutting surface 72 opposite to the pressing surface 71 and facing one side of the water outlet contact part 52, and a second protruding ring part located inside the core 7. The check valve core 4 is inserted into the through hole provided on the water outlet contact part 52, and the first groove is clamped with the first protruding ring part provided on the water outlet contact part 52, and further the second groove is clamped with the second protruding ring part. In other embodiments, the mutual fixation of the water outlet contact part 52, the independent core 7 and the check valve core 4 can also adopt other fixation modes suitable for the cooperation of flexible materials and rigid shaft cores, and is not limited to the clamping of grooves and protruding rings. The pressing surface 71 is located inside the abutting surface 72, and the radial dimension of the pressing surface 71 is smaller than that of the abutting surface 72. The independent core 7 is wedge-shaped, and the independent core 7 is attached to the water outlet contact part 52 provided on the upper ring chamber rubber sleeve 5 and embedded in the mold. During the wax injection process, the wedge-shaped rubber pad is clamped out through the check valve or check flow channel by using tweezers and other tools, the cavity of the wax mold mold is manufactured, and the purpose of weight reduction and uniform wall thickness is achieved. The independent core 7 is wedge-shaped, which increases the channel area and water flow volume at the anti-backflow inlet, thereby improving the overall measurement accuracy of the water meter.

[0072] In the first embodiment of the present application, the process weight reduction mainly lies in that during modeling and forming, soft materials such as independent core 7 are used to occupy the positions needing weight reduction, so that the wax liquid cannot fill the area during the forming process, forming a cavity to achieve the effect of weight reduction.

[0073] A method for manufacturing a wax mold by using a shell mold casting mold 1000, comprising the following steps:

[0074] First, assemble the mold; wherein the assembly of the mold is divided into the following steps

[0075] 1) Separate the upper mold plate 201 from the lower mold plate 202;

[0076] 2) The upper ring chamber rubber sleeve 5 is sleeved on the first base 131 of the main core 1, the lower ring chamber rubber sleeve 6 is sleeved on the second base 132 of the main core 1, the main core 1 is loaded into the main core chamber 203, and the tangent surface of the head 11 of the main core 1 is attached to the end surface of the first opening 2031 of the main core chamber 203, so that the main core 1 is assembled to the accurate position;

[0077] 3) The independent core 7 is installed at the bottom of the check valve core 4, and then the check valve core 4 is loaded into the check valve cavity 206, and the tangent surface of the check valve fixing portion 41 of the check valve core 4 is attached to the end surface of the fourth opening 2061 of the check valve cavity 206, and the independent core 7 is located in the core groove 2064 so that the check valve core 4 is configured to the accurate position;

[0078] 4) The water outlet core 3 is loaded into the water outlet cavity 205, and in this process, the first water outlet core 33 and the second water outlet core 34 are installed, and then the installed water outlet core 3 is loaded into the water outlet cavity 205, and the abutting portion 331 of the water outlet core 3 close to the main core 1 abuts against the check valve core 4 until the tangent surface of the water outlet fixing portion 31 abuts against the end surface of the third opening 2051 of the water outlet cavity 205, and the water outlet core 3 is configured to the accurate position;

[0079] 5) The water inlet core 2 is loaded into the water inlet cavity 204, and the tangent surface of the water inlet fixing portion 21 of the water inlet core 2 is attached to the end surface of the second opening 2041 of the water inlet cavity 204, and the side of the water inlet core 2 close to the main core 1 contacts the water inlet contact portion 62, so that the water inlet core 2 is configured to the accurate position;

[0080] 6) The upper mold plate 201 is covered on the lower mold plate 202, and the upper mold plate 201 and the lower mold plate 202 are fixed by the fixing structure; during the assembly of the mold, it is necessary to pay attention to whether the alloy material is worn, and whether the size of the upper ring chamber rubber sleeve and the lower ring chamber rubber sleeve is accurate; the sequence of steps 1) to 6) is not limited;

[0081] Second step, align the wax injection hole with the wax injection nozzle, and let the wax flow into the main core cavity 203, the inlet cavity 204, the outlet cavity 205, the check cavity 206 and the core groove 2064 through the flow guide cavity 208, and the wall thickness of the wax mold formed at the core groove 2064 is uniform with the wall thickness of other parts of the wax mold, in this process, the general shape of the wax mold is formed;

[0082] Third step, delay pressure setting of the wax mold;

[0083] Fourth step, open the mold to take the wax mold, which includes the following steps in the process:

[0084] 1) The air gun sprays air into the air hole 14 to avoid deformation of the wax mold caused by the bottom vacuum, and the air pressure is enough to automatically lift the main core 1;

[0085] 2) Extract the inlet core 2;

[0086] 2) Extract the outlet core 3, first extract the second outlet core 34, then extract the first outlet core 33 with the abutting part 331;

[0087] 3) Extract the main core 1, at this time the upper ring chamber rubber sleeve 5 and the lower ring chamber rubber sleeve 6 sleeved on the first base 131 and the second base 132 lose support;

[0088] 4) Extract the check core 4, the independent core 7 loses support and falls into the weight reduction area of the wax mold (the weight reduction area at this time communicates with the check passage of the wax mold);

[0089] 5) Put the wax mold into the ice water tank to continue setting, and after the wax blank is completely cooled and set, the upper ring chamber rubber sleeve 5, the lower ring chamber rubber sleeve 6 and the independent core 7 are taken out from the cavity of the wax mold by tweezers or other tools; the sequence of steps 1) to 5) is not limited.

[0090] In the present application, by setting the wedge-shaped independent core 7, embedding into the inside of the mold (the lower surface of the water outlet contact part 52 of the upper ring chamber rubber sleeve 5), during the wax injection process, the independent core 7 is clamped out through the check valve or the upper water outlet hole 4031 by using tweezers and other tools when the core is pulled out after the wax type is solidified, to manufacture the wax mold cavity, to ensure the purpose of reducing weight and uniform wall thickness. And, since the independent core 7 and the second convex ring part and the first convex ring part of the upper ring chamber rubber sleeve 5 are respectively clamped in the second groove and the first groove of the check valve core 4, the positioning function is achieved by nesting cooperation, and the obtained product is beautiful and high in accuracy. The casting mold 1000 using the shell mold can obtain a complete wax mold (shell mold), and the shell is not easy to deform, misplace, mix, shrinkage and other casting defects when cast using the complete wax mold, at the same time, the shell produced by the wax mold does not need to be split welded, and there is no welding seam, thereby ensuring the product quality of the shell. And, the casting mold 1000 of the shell mold can make the wax mold one-time forming, reduce the wax mold manufacturing link, improve the production efficiency of the wax mold, and further improve the production efficiency of the water meter shell.

[0091] The independent core 7 used now is made of special silica gel, which is a silica gel soft pad, and the hardness range is 26-29. If the hardness is too large, it is difficult to take out small size products; if the hardness is too small, the wax liquid of large size products is squeezed and deformed after flowing in, and the uniformity of wall thickness cannot be guaranteed. The wedge-shaped rubber pad in the present application has a hardness of 26-29, which can be well formed. At the same time, the independent core 7, the upper ring chamber rubber sleeve 5 and the lower ring chamber rubber sleeve 6 are made of three kinds of silica gel with different hardness, which realizes the convenience of product production. The other two kinds of silica gel have a hardness of 20-25 or 35-37. The rubber sleeve core (the upper ring chamber rubber sleeve 5 and the lower ring chamber rubber sleeve 6) is made of silica gel with different hardness according to needs.

[0092] The check valve of the wax mold mold is formed by inserting the check valve core sleeve of the hard material at the check valve position and the water outlet contact part 52 extending obliquely downward from the upper ring chamber rubber sleeve in the casting mold. The independent core 7 is a wedge-shaped rubber pad, which is attached to the bottom of the side of the water outlet contact part 52 extending obliquely downward from the upper ring chamber rubber sleeve 5 facing the water inlet core 2, and its role is to manufacture the wax mold cavity in the form of occupying space, to ensure the uniformity of wall thickness and reduce the single weight of the product. The wedge-shaped rubber pad is attached to the bottom of the water outlet contact part of the upper ring chamber rubber sleeve 5 by the existence of certain adhesion between the rubber pads, and is embedded into the inside of the mold, which plays a role in occupying space during the wax injection process. When the core is pulled out after the wax type is solidified, the wedge-shaped rubber pad is clamped out through the check valve by using tweezers and other tools, to manufacture the wax mold cavity, to ensure the purpose of reducing weight and uniform wall thickness.

[0093] In the present application, a ring of protruding structures is added to the wedge-shaped structure, namely the second protruding ring part mentioned above, the check valve core 4 is arranged in parallel with two annular grooves (first groove and second groove) in the axial direction of the check valve cavity 206, during actual embedding assembly, the check valve core 4 passes through the through hole arranged in the water outlet contact part, and the first protruding ring part is matched with the first groove, and the second protruding ring part of the independent core 7 is embedded in the second groove, so as to achieve the positioning function through the nested matching, and the obtained product is beautiful and has high accuracy. Because the position is at the bottom, and the peripheral structure is complex, if hard material is used for the positioning work, under the adhesion of the wax liquid itself, it is difficult or impossible to take out, and forced taking out will damage the wax mold, thereby being scrapped.

[0094] Therefore, the wedge-shaped rubber pad at this position must be a soft material for the purpose of weight reduction, so that the operator can easily take it out by clamping without damaging the wax mold. The original wedge-shaped rubber pad is only a small wedge-shaped pad, and the weight reduction area is small. Although the small independent part can be taken out, the work efficiency of the operator is reduced, which is not conducive to productivity. Therefore, after many tests on the elasticity and hardness of the soft material rubber sleeve in the wedge-shaped rubber pad and the overall mold, a balance point is found, and the size of the part is increased and a triangular weight reduction structure is formed, which increases the weight reduction space. At the same time, the increased weight reduction wedge-shaped rubber pad can allow the operator to use the air gun to quickly blow out the rubber pad through air pressure, thereby improving the work efficiency.

[0095] Please refer to Figures 7 to 17 , the second embodiment of the present application, the shell mold casting mold 1000' includes a main mold plate 200' and a combined core 100' received and held on the main mold plate 200'. The main mold plate 200' is basically the same as in the first embodiment, except that in the first embodiment, the independent core 7 made of soft silicone rubber is used to form the positioning, while in the second embodiment, the core 5' made of metal is used to achieve the positioning, which needs to be attached to other combined cores (100'), and the second embodiment does not have upper ring chamber rubber sleeve and lower ring chamber rubber sleeve. When the space to be occupied is relatively large, a silicone rubber core is used to achieve the positioning, and when the space to be occupied is relatively small, a metal core 5' is used to achieve the positioning.

[0096] The main body template 200' comprises an upper template 201' and a lower template 202' which are embedded in an upper-lower manner. The upper template 201' and the lower template 202' are symmetrically arranged and are clamped to each other via a fixing structure 209' penetrating through the upper template 201' and the lower template 202'. The main body template 200' further comprises a main core cavity 203' arranged in a ring manner in the upper template 201' and the lower template 202', a water inlet cavity 204' located at one side of the main core cavity 203' and communicating with the main core cavity 203', a water outlet cavity 205' located at the other side of the main core cavity 203' and arranged opposite to the water inlet cavity 204' and communicating with the main core cavity 203', a core groove 2064' connecting and transitioning the main core cavity 203' and the water outlet cavity 205' and located between the water outlet cavity 205' and the main core cavity 203', a check port cavity 206 communicating with the core groove 2064' and located between the main core cavity 203' and the water outlet cavity 205', a wax injection hole 207' arranged opposite to the main core cavity 203' at one side of the main body template 200', and a flow guide cavity 208' communicating between the wax injection hole 207' and each cavity. The main body template 200' further comprises the fixing structure 209' arranged at four corners for fixing the upper template 201' and the lower template 202'. The fixing structure 209' comprises a fixing hole 209a' and a fixing column 209b' arranged corresponding to the fixing hole 209a'. The main core cavity 203' is provided with a first opening 2031' located at the end side of the main body template 200', a surrounding cavity 2034' adjacent to the first opening 2031' and having a size not greater than the first opening 2031', a first positioning ring cavity 2032' adjacent to the surrounding cavity 2034' and having a size greater than the first opening 2031', and a second positioning ring cavity 2033' located at the other end of the first positioning ring cavity 2032' and having a size greater than the first positioning ring cavity 2032'. The water inlet cavity 204' is provided with a second opening 2041' located at the end side of the main body template 200', a first base cavity 2042' adjacent to the second opening 2041' and having a size not greater than the second opening 2041', and a first annular cavity 2043' located inside the first base cavity 2042' and having a size greater than the second opening 2041'. The water outlet cavity 205' comprises a third opening 2051' located at the end side of the main body template 200', a second base cavity 2052' adjacent to the third opening 2051' and having a size not greater than the third opening 2051', and a second annular cavity 2053' located inside the second base cavity 2052' and having a size greater than the third opening 2051'.The check valve cavity 206' includes a fourth opening 2061 at the end side of the main body template 200, a third base cavity 2062' adjacent to the fourth opening 2061' and having a size not greater than the fourth opening 2061', a third annular cavity 2063' inside the third base cavity 2062' and having a size greater than the fourth opening 2061', and a core recess 2064' inside the third annular cavity 2063'. The cross section of the core recess 2064' is triangular to facilitate demolding. Of course, the core recess 2064' can also be provided in other shapes as long as demolding is facilitated. The check valve cavity 206' extends from the core recess 2064' to the outer end side of the main body template 200'.

[0097] Please continue to refer to Figures 1 to 6 The combined core 100' includes the main core 1' held and inserted into the main core cavity 203', the water inlet core 2' held and inserted into the water inlet cavity 204' and in contact with one side of the main core 1', the water outlet core 3' held and inserted into the water outlet cavity 205' and in contact with the other side of the main core 1', the check valve core 4' held and inserted into the check valve cavity 206' and in contact with the same side of the main core 1' as the water outlet core 3', and the core 5' held and inserted into the core recess 2064' and in contact with the check valve core 4'. The core 5' is pluggable combined with the check valve core 4'. In other embodiments, the core 5' can be integrally formed at the bottom end of the check valve core 4'. In this embodiment, the core 5' is split combined with the check valve core 4'.

[0098] The main core 1' includes a head 11' exposed to the end side of the main body template 200' and exposed to the first opening 2031, a mounting portion 16' held in the surrounding cavity 2034', and a first surrounding portion 14' and a second surrounding portion 15' positioned in the first positioning ring cavity 2032' and the second positioning ring cavity 2033'. The radial dimension of the mounting portion 16' is equivalent to that of the surrounding cavity 2034'. The first surrounding portion 14' is located on the upper side of the second surrounding portion 15'. The radial dimensions of the first surrounding portion 14' and the second surrounding portion 15' are smaller than those of the first positioning ring cavity 2032' and the second positioning ring cavity 2033', and the remaining gaps are filled with paraffin during the wax injection process. The first surrounding portion 14' extends downwardly to the side of the check valve core 4' to form a water outlet contact portion 138' in contact with the check valve core 4'. The end of the water outlet contact portion 138' is provided with a positioning hole 1381' penetrating the upper and lower surfaces thereof for inserting the check valve core 4', and a positioning notch 1382' located on the inner wall of the positioning hole 1381' and close to the side of the water inlet core 3'. The second surrounding portion 15' extends upwardly to the side of the water inlet core 2' to form a water inlet contact portion 139' in contact with the water inlet core 2'. The main core 1' further includes a main core center insert 12' located at the middle position, and a plurality of annular array of main core side edge inserts 13' around the main core center insert 12' to maintain the cylindrical shape of the main core 1'. Adjacent main core side edge inserts 13' abut each other, and at least one of the main core side edge inserts 13' is in contact with the check valve core 4' and the core 5'. The number of main core side edge inserts 13' is greater than 2. In this embodiment, the main core side edge insert (13') includes a circumferential insert (132' / 133' / 134') forming the water outlet contact portion (138'), and a abutting side edge insert (1321' / 1331') located below the circumferential insert abutting the lower end surface of the circumferential insert. The dimensions of the circumferential insert (132' / 133' / 134') and the abutting side edge insert (1321' / 1331') along the axial direction of the main core (1') are equivalent to those of other main core side edge inserts (13') along the axial direction of the main core (1'). In this embodiment, the main core side edge insert 13' includes a first side edge insert 131' abutting the upper die template 201', a second side edge insert 132' adjacent to the first side edge insert 131' and provided with the water outlet contact portion 138', a third side frame 133' and a fourth side edge insert 134', a fifth side edge insert 135' located on the other side of the fourth side edge insert 134', and a sixth side edge insert 136' and a seventh side edge insert 137' facing the water inlet core 2'.The water inlet contact part 139' is located on at least one of the main core side blocks 13' and contacts the water inlet core 2'. The main core side block 13' forming the water inlet contact part 139' is arranged opposite to the main core side block 13' forming the water outlet contact part 138'. In this embodiment, the water inlet contact part 139' is located on the sixth side block 136' and the seventh side block 137'. The water outlet contact part 138' is located on at least one of the main core side blocks 13' and contacts the check core 4' and the water outlet core 3'. In this embodiment, the water outlet contact part 138' is located on the second side block 132', the third side block 133' and the fourth side block 134'. In this embodiment, the main core side blocks 13' further comprise the eighth side block 1321' and the ninth side block 1331' arranged below the second side block 132', the third side block 133' and the fourth side block 134' and abutting the lower surfaces of the second side block 132', the third side block 133' and the fourth side block 134'. The height (length) of the second side block 132', the third side block 133' and the fourth side block 134' combined with the eighth side block 1321' and the ninth side block 1331' is equivalent to the height (length) of the other side blocks 13' including the first side block 131'. The eighth side block 1321' and the ninth side block 1331' are arranged on the second side block 132', the third side block 133' and the fourth side block 134' provided with the water outlet contact part 138' to provide an upward supporting force when the second side block 132', the third side block 133' and the fourth side block 134' are taken out separately during the opening of the casting mold 1000', so as to better complete the demolding. In this embodiment, the side blocks are the second side block 132', the third side block 133' and the fourth side block 134'. The abutting side blocks are the eighth side block 1321' and the ninth side block 1331'. In other embodiments, the number of the main core side blocks 13' is not limited. The contact surfaces of the seven side blocks of the main core side blocks 13' are parallel to each other, and the adjacent side blocks abut each other. One side of the check core 4' is connected to at least one of the main core side blocks 13'. When the main core 1' is demolded, the main core side blocks 13' can be taken out separately in sequence after being disassembled, so as not to damage the wax mold due to the pulling action when the core is demolded.

[0099] The main core side edge block 13' further comprises a side edge block arranged separately from other main core side edge blocks below the water outlet contact portion 138'. Such design is due to the structure of the main core 1' with a small mouth and a large belly, and the main core 1' needs to be taken out in blocks. Meanwhile, the size of the part of the combined core 100' exposed to the main mold plate 200' is greater than the size of the part of the combined core located in the main mold plate 200', and the cross section of the part of the combined core 100' exposed to the main mold plate 200' is substantially circular or rectangular, and the cross section of the part of the combined core 100' exposed to the main mold plate 200' is fitted to the end face outside the main mold plate 200'. The radial dimension of the head 11' of the main core 1' is greater than the size of the first opening 2031', which is convenient for the operator to have a recombination base surface when recombining the core, which guarantees the work efficiency of the operator; secondly, the large circular surface has a greater force area for the operator's core pulling action, which can increase the work efficiency of the operator; thirdly, and most importantly, the accurate and rapid positioning of the main core 1' is judged by whether the large circular surface and the exposed edge of the main core cavity 203' are in close contact. The annular positioning structure of the main core cavity 203' is cooperated with the large circular surface outside the main core mold to achieve the positioning effect.

[0100] The water inlet core 2' comprises a water inlet contact portion 23' in contact with the water inlet end of the main core 1', and the size of the water inlet contact portion 23' is greater than the second opening 2041', so the water inlet core 2' is also arranged separately, that is, the water inlet core 2' comprises a water inlet center block 21' and a plurality of water inlet side edge blocks 22' arranged in an annular array around the water inlet center block 21' to make the water inlet core 2' arranged in a cylindrical shape. In this embodiment, the number of water inlet side edge blocks 22' is 5, and in other embodiments, the number of water inlet side edge blocks 22' is not limited. The water inlet core 2' further comprises a first combining portion 24' in contact with the water inlet contact portion 139'. At least one of the water inlet side edge blocks 22' is in contact with the water inlet contact portion 139'. The number of water inlet side edge blocks 22' is not less than 2. The part of the water inlet core 2' located in the first base cavity 2042' is equivalent to the radial dimension of the first base cavity 2042', and the part of the water inlet core 2' located in the first annular cavity 2043', that is, the radial dimension of the water inlet contact portion 23' is smaller than the radial dimension of the first annular cavity 2043, and the remaining gap is filled with paraffin during the wax injection process to form a part of the wax mold.

[0101] The water outlet core 3' includes a water outlet fixing part 31' exposed to the third opening 2051' and a second combining part 32' in contact with the water outlet contact part 138'. The radial dimension of the water outlet fixing part 31' is greater than the dimension of the third opening 2051', which has the same effect as the head part 11 of the main core 1. Firstly, it provides a recombination base for the operator during the core recombination, which guarantees the work efficiency of the operator. Secondly, it provides a greater force area for the operator during the core recombination, which can increase the work efficiency of the operator. Thirdly, and most importantly, the accurate and rapid positioning of the water outlet core 3' is determined by whether the cutting surface of the water outlet fixing part 31' and the exposed edge of the water outlet cavity 205' are in close contact. Since the dimension of the second combining part 32' is greater than the dimension of the third opening 2051', a structure with a small mouth and a large belly is formed here. The water outlet core 3' at this time includes a first water outlet core 33' in contact with the check valve core 4' and a second water outlet core 34' for accommodating the water outlet contact part 138' together with the port of the first water outlet core 33'. The first water outlet core 33' further includes a contact part 331' in contact with the check valve core 4'. The contact part 331' is to form the communication position of the check valve cavity 4052 and the water outlet passage 402 when forming the shell mold. The part of the water outlet core 3' located in the second base cavity 2052' has a radial dimension corresponding to that of the second base cavity 2052'. The radial dimension of the part of the water outlet core 3' located in the second annular cavity 2053' is smaller than that of the second annular cavity 2053'. The remaining gap is filled with paraffin during the wax injection process to form part of the wax mold.

[0102] The check valve core 4' includes a check valve fixing part 41' exposed to the fourth opening 2061' and a third combining part 42' in contact with the water outlet contact part 138'. The radial dimension of the check valve fixing part 41' is greater than the dimension of the fourth opening 2061', which has the same effect as the head part 11' of the main core 1'. The dimension of the part of the check valve core 4' located inside the main mold plate 200' is smaller than the dimension of the fourth opening 2061'. The part of the check valve core 4' located in the third base cavity 2062' has a radial dimension corresponding to that of the third base cavity 2062'. The radial dimension of the part of the check valve core 4' located in the third annular cavity 2063' is smaller than that of the third annular cavity 2063'. The remaining gap is filled with paraffin during the wax injection process to form part of the wax mold. The check valve core 4' further includes a clamping part for clamping the core 5'.

[0103] The core 5' is made of metal and is located in the core groove 2064'. The cross-sectional width of the core 5' perpendicular to the axial direction of the check valve cavity 206' is adapted to the radial width of the check valve core 4'. The core groove 2064' is located below the check valve cavity 206' at the area where the main core cavity 203' and the water outlet cavity 205' are connected. The core 5' occupies the position at this time, and during the process of forming the wax mold, a cavity is formed, so that the wall thickness at the cavity of the wax mold is uniform, the quality is light, and the weight reduction effect is achieved. The core 5' is a two-piece structure, including a second split core 52' facing the water outlet core 3' on one side of the check valve core 4' clamped in the check valve core 4', and a first split core 51' combined with the second split core 52' to form the core 5'. The second split core 52' protrudes a positioning protrusion 521' to one side of the water outlet core 3' and has an annular portion with a radial dimension adapted to the end portion of the check valve core 4' and a wedge-shaped pressing surface 53' pressed on one side in the main mold plate 200' toward the check valve core 4'. The bottom end of the core 5' at the pressing surface 53' is to form an occupying position, further forming a weight reduction portion 407 during the formation of the shell mold. The positioning protrusion 521' is clamped in the positioning notch 1382' provided in the water outlet contact portion 138' of the main core 1'. The annular portion is clamped in the clamping portion. That is, the core 5' passes through the positioning hole 1381', and the positioning protrusion 521' is clamped in the positioning notch 1382', and the annular portion is clamped in the clamping portion. The positioning protrusion 521' is formed to form the bottom of the check flow channel 4051 during the formation of the shell mold. The core 5' is embedded in the mold, which plays an occupying role during the wax injection process. After the wax mold is solidified, the core 5' is split and taken out through the check valve, and the cavity of the wax mold is manufactured to ensure the purpose of weight reduction and uniform wall thickness. The wedge-shaped structure of the pressing surface 53' of the core 5' increases the channel area and water flow volume at the anti-backflow inlet, thereby improving the overall measurement accuracy of the water meter.

[0104] The core 5' is integrally connected to the check valve core 4', and the positioning protrusion 521' is used to form the bottom of the check flow channel 4051. During the opening process of the casting mold 1000' of the shell mold, the core 5' can be taken out with the check valve core 4', which increases the convenience of operation.

[0105] In the second embodiment of the present application, the process weight reduction mainly lies in that during modeling and forming, the core 5' is used to occupy the position where weight reduction is needed, so that the wax liquid cannot be filled in this area during the forming process, a cavity is formed, and the weight reduction effect is achieved.

[0106] A method for manufacturing a wax mold by a casting mold 1000' of a shell mold, comprising the following steps:

[0107] A first step of assembling the mold; wherein the assembling of the mold comprises the following steps

[0108] 1) separating the upper mold plate 201' from the lower mold plate 202';

[0109] 2) assembling the main core center insert 12' and the main core side insert 13' of the main core 1' and then loading them into the main core cavity 203', and allowing the tangent plane of the head 11' of the main core 1' to fit the end face of the first opening 2031' of the main core cavity 203' so that the main core 1' is arranged in the correct position;

[0110] 3) loading the first split core 51' and the second split core 52' into the check valve core 4', fixing them in the check valve core 4' through the interaction of the annular part and the clamping part, loading the check valve core 4' into the check valve cavity 206' and allowing the core 5' to be loaded into the core groove 2064', and at the same time, the core 5' is clamped in the positioning hole 1381' of the main core 1', until the positioning protrusion 521' is clamped into the positioning notch 1382'; loading the check valve core 4' into the check valve cavity 206', and allowing the tangent plane of the check valve fixing part 41' of the check valve core 4' to fit the end face of the fourth opening 2061' of the check valve cavity 206', and to be arranged in the correct position;

[0111] 4) loading the water outlet core 3' into the water outlet cavity 205'; in this process, first, the first water outlet core 33' and the second water outlet core 34' are assembled and then loaded into the water outlet cavity 205'; when the abutting part 331' abuts on one side of the check valve core 4', until the tangent plane of the water outlet fixing part 31' fits the end face of the third opening 2051' of the water outlet cavity 205', and is arranged in the correct position;

[0112] 5) after the water inlet center insert 21' and the water inlet side insert 22' of the water inlet core 2' are assembled, they are loaded into the water inlet cavity 204', and the tangent plane of the water inlet fixing part 21' of the water inlet core 2' is allowed to fit the end face of the second opening 2041' of the water inlet cavity 204'; one side of the water inlet core 2' in the water inlet cavity 204' abuts on the water inlet contact part 139', and is arranged in the correct position;

[0113] 6) covering the lower mold plate 202' with the upper mold plate 201', and fixing the upper mold plate 201' and the lower mold plate 202' by the fixing structure 209'; wherein the sequence of steps 1) to 6) is not limited;

[0114] Secondly, the mold injection wax hole is aligned with the wax injection nozzle, and the wax liquid is flowed into the main core cavity 203', the water inlet cavity 204', the water outlet cavity 205' and the check cavity 206' through the flow guide cavity 208', and the approximate shape of the wax mold is formed in the process; the process is maintained for about 15-30 seconds, and the temperature is 52-58 DEG C;

[0115] Thirdly, the wax mold is delayed and pressure-set to be shaped;

[0116] Fourthly, the mold is opened to take the wax mold, and the following steps are included in the process:

[0117] 1) The air gun enters by spraying air around the main core 1', avoiding deformation of the wax mold caused by bottom vacuum, and locally topping the main core 1';

[0118] 2) The main core 1' is divided into pieces and pulled out upward, the main core center insert 12' is pulled out first, and then the main core side insert 13' is pulled out in multiple times;

[0119] 3) The check core 4' is pulled out with the first split core 51', and then the second split core 52' with the positioning protrusion 521' is pulled out by using tweezers or other tools;

[0120] 4) The water outlet core 3' is pulled out in pieces, the second water outlet core 34' is pulled out first, and then the first water outlet core 33' with the abutting part 331' is pulled out;

[0121] 5) The water inlet core 2' is pulled out in pieces, the water inlet center insert 21' is pulled out first, and then the water inlet side insert 22' is pulled out, and the sequence of steps 1) to 5) is not limited.

[0122] In the application, the core 5' is arranged to occupy a position during the wax injection process, and when the core is pulled out after the wax mold is solidified, the check core 4' is pulled out through the fourth opening arranged in the check cavity 206', and the core 5' is pulled out at the same time, so as to form a cavity of the wax mold, and the purpose of weight reduction and uniform wall thickness is achieved. The casting mold 1000' using the shell mold can obtain a complete wax mold, and the shell is not easy to deform, misplace, mix, shrinkage and other casting defects when the shell is cast using the complete wax mold, and the shell produced by the wax mold does not need to be split welded, and the welding seam is not generated, so that the product quality of the shell is ensured. Moreover, the casting mold 1000 of the shell mold can make the wax mold one-time forming, reduce the wax mold manufacturing link, improve the production efficiency of the wax mold, and further improve the production efficiency of the shell.

[0123] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent substitutions for some or all of the technical features thereof; and such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0124] The above only describes some embodiments of the present application, not all embodiments, and any equivalent changes made by those of ordinary skill in the art to the technical solutions of the present application by reading the specification of the present application are covered by the claims of the present application.

Claims

1. A casting mold (1000) of a shell mold, comprising a main mold plate (200) having a combined cavity and a combined core (100) held in engagement in the combined cavity, the combined cavity comprising a main core cavity (203) formed inwardly on one side of the main mold plate (200), a water inlet cavity (204) located on one side of the main core cavity (203) and in communication with the main core cavity (203), and a water outlet cavity (205) located on the other side of the main core cavity (203) and opposite the water inlet cavity (204) and in communication with the main core cavity (203), the main core cavity (203) being provided with a first opening (2031) located on the end side of the main mold plate (200), and a surrounding cavity (2034) adjacent to the first opening (2031) and having a size not greater than that of the first opening (2031), the combined core (100) comprising a main core (1) held in the main core cavity (203), a water inlet core (2) held in the water inlet cavity (204) and in contact with one side of the main core (1), and a water outlet core (3) held in the water outlet cavity (205) and in contact with the other side of the main core (1), characterized in that: The combined cavity further comprises a core groove (2064) connecting and transitioning the main core cavity (203) and the water outlet cavity (205), the combined core (100) further comprises a separate core (7) arranged in the core groove (2064), the part of the combined core (100) exposed outside the main mold plate (200) has a larger size than the part of the combined core (100) arranged in the main mold plate (200), the cross section of the part of the combined core (100) exposed outside the main mold plate (200) is circular or rectangular, and the cross section of the part of the combined core (100) exposed outside the main mold plate (200) is matched with the end surface outside the main mold plate (200).

2. The casting mold for a case mold according to claim 1, characterized by: The combined cavity of the main mold plate (200) further comprises a check cavity (206) arranged between the main core cavity (203) and the water outlet cavity (205) and communicating with the core groove (2064), and the combined core (100) further comprises a check core (4) arranged in the check cavity (206) and in contact with one side of the main core (1).

3. The casting mold for a shell mold as recited in claim 2, characterized by: The check cavity (206) communicates with the water outlet cavity (205) and is arranged opposite to the core groove (2064), and the cross section width of the separate core (7) perpendicular to the axial direction of the check cavity (206) is adapted to the radial width of the check core (4).

4. The casting mold for a shell mold as recited in claim 3, characterized by: The separate core (7) is a wedge-shaped structure.

5. The casting mold for a shell mold as recited in claim 4, characterized by: The main core (1) comprises a water outlet contact portion (52) extending downwardly and obliquely from one side of the main core (1) and in contact with the separate core (7), and the separate core (7) is attached to the bottom surface of the side of the water outlet contact portion (52) facing the water inlet core (2).

6. The casting mold for a shell mold as recited in claim 5, characterized by: The check core (4) is provided with a second groove in the axial direction of the check cavity (206), the water outlet contact portion (52) is provided with a through hole, and the separate core (7) is provided with a second convex ring portion, the check core (4) passes through the through hole and cooperates with the second groove and the second convex ring portion.

7. The casting mold for a shell mold as recited in claim 6, characterized by: The main core (1) comprises a mounting portion (12) and a stepped portion (13) arranged in the main core cavity (203), the stepped portion (13) comprises a first base portion (131) and a second base portion (132) extending downwardly from the first base portion (131), the combined core (100) further comprises a rubber sleeve core arranged on the main core (1), and the rubber sleeve core is made of silica gel.

8. The casting mold for a shell mold as recited in claim 7, characterized by: The water outlet contact portion (52) and the rubber sleeve core are integrally formed and made of the same material.

9. The casting mold for a shell mold as recited in claim 8, characterized by: The rubber sleeve core comprises an upper ring chamber rubber sleeve (5) sleeved on the first base (131) and a lower ring chamber rubber sleeve (6) sleeved on the second base (132), and the water outlet contact part (52) is inclined downward from the part of the upper ring chamber rubber sleeve (5) sleeved on the main core (1) to one end of the core groove (2064).

10. The casting mold for a shell mold as recited in claim 9, characterized by: The side of the lower ring chamber rubber sleeve (6) opposite to the water outlet contact part (52) is inclined upward to form a water inlet contact part (62) in contact with one end of the water inlet core (2).

11. The casting mold for a shell mold as recited in claim 10, characterized by: The check valve core (4) is further provided with a first groove parallel to the second groove in the axial direction of the check valve cavity (206), the water outlet contact part (52) is provided with a first convex ring part in the through hole, and the first groove and the first convex ring are fixedly matched.

12. A mold closing method of a casting mold of a shell mold as defined in claim 9, characterized by: The method comprises the following steps: Sleeving the upper ring chamber rubber sleeve (5) on the first base (131) of the main core (1), sleeving the lower ring chamber rubber sleeve (6) on the second base (132) of the main core (1), and loading the main core (1) into the main core cavity (203); Loading the independent core (7) at the bottom of the check valve core (4), then loading the check valve core (4) into the check valve cavity (206), and locating the independent core (7) in the core groove (2064) so that the check valve core (4) is arranged at the accurate position; Loading the water outlet core (3) into the water outlet cavity (205) so that one side of the water outlet core (3) abuts against the check valve core (4); Loading the water inlet core (2) into the water inlet cavity (204); Clamping the main mold plate (200) to complete the clamping assembly of the casting mold of the shell mold.

13. A mold opening method of a casting mold of a shell mold as defined in claim 9, characterized by: The method comprises the following steps: Separating the main mold plate (200) from top to bottom; Extracting the water inlet core (2); Extracting the water outlet core (3) in two parts; Extracting the main core (1), at this time, the upper ring chamber rubber sleeve (5) and the lower ring chamber rubber sleeve (6) sleeved on the first base (131) and the second base (132) lose support; Extracting the check valve core (4); Extracting the upper ring chamber rubber sleeve (5), the lower ring chamber rubber sleeve (6) and the independent core (7) from the check valve cavity (206).

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