Salt core melt casting apparatus and method for aluminum pistons

Abstract

The application provides a salt core melting and casting equipment and method for an aluminum piston, which comprises a casting machine main machine, a salt core melting and holding furnace and a hydraulic station, and the casting machine main machine comprises a bed body, a top die mechanism and an opening and closing mechanism. The top die mechanism comprises a top die stand, a top die cross beam, a top die oil cylinder, guide rods connected through a connecting block, a top die connecting plate, a top die connecting rod and a top die. The opening and closing mechanism comprises an outer die oil cylinder, an outer die sliding table, a core pulling oil cylinder, a mold core sliding block and a mold core. The top die mechanism is provided with a pressurizing device, and the pressurizing device comprises a gas control normally open valve and a gas control normally closed valve connected with a top die pressurizing port respectively, a filtering pressure reducing valve connected with external compressed air, and a top die pressurizing valve connected between the filtering pressure reducing valve and the gas control normally closed valve. Through the technical scheme, the salt core can be produced by melting and casting, and the special-shaped salt core can be produced. The process flow is simple, the environmental pollution is small, the waste material can be recycled and utilization, and the waste is not easy to cause.

Description

Technical Field

[0001] This invention relates to the field of salt core production equipment technology, and more specifically, to a salt core casting equipment and method for aluminum pistons. Background Technology

[0002] With increasingly stringent emission standards and higher performance requirements for engines, there is a growing need to improve engine power output and power per liter. Ordinary aluminum pistons are insufficient to meet these evolving design demands; therefore, current piston designs typically incorporate internal oil cooling channels. Pistons with internal oil cooling channels generally have a salt core placed in the casting during the casting process. Figure 1 As shown, after casting, high-pressure water is used to flush out the salt core inside the piston, forming an internal cooling oil passage cavity inside.

[0003] In related technologies, salt core production involves placing a mixture of salt powder and additives into a mold, which is then mounted on a four-column press. Figure 2 As shown, the four-column press 10 includes an auxiliary oil tank 102, a crossbeam 104, a main cylinder 106, a guide column 108, an ejector cylinder 110, a worktable 112, and a pressure plate 114. A mold is installed on the worktable 112, and salt powder is pressed into shape using an extrusion production mode to produce salt core blanks. After pressing and drying, the blanks are machined to the finished size using a lathe and then placed in a drying oven for drying before use. Although salt cores manufactured in this way have high strength and are suitable for mass production, they have disadvantages such as serious salt powder contamination and a relatively cumbersome process. Furthermore, with the increasing power requirements of engines, the requirements for piston cooling performance are also increasing, leading to the emergence of irregularly shaped internal cooling oil passage designs in piston design. Existing salt core manufacturing methods are difficult to mass-produce irregularly shaped salt cores, such as… Figure 3 As shown. The specific technical defects of the existing salt core production method are as follows:

[0004] (1) Pressure manufacturing of salt cores uses salt powder as its raw material. Salt powder is a powder with very small particles. Salt powder is very easy to cause environmental pollution and can be easily inhaled by workers, causing physical damage.

[0005] (2) The existing salt core manufacturing process requires pressing the salt core with a press first, drying the salt core after pressing, processing it on a lathe after drying, and finally baking it in a heat preservation furnace. The manufacturing process is complicated and involves many steps. The waste materials used to make the salt core cannot be recycled, which easily leads to waste.

[0006] (3) Existing salt core production requires machining on a lathe. Due to the limitations of its machining characteristics, existing salt cores can only be designed as rotating bodies and cannot be manufactured as irregularly shaped salt cores, thus limiting the design of piston internal cooling channels. Summary of the Invention

[0007] The present invention aims to solve at least one of the technical problems existing in the prior art or related art.

[0008] Therefore, the purpose of this invention is to provide a molten salt casting equipment and method for aluminum piston salt cores, which can realize the production of salt cores by molten salt casting, can produce irregularly shaped salt cores, and has a simple process, low environmental pollution, and recyclable waste, thus avoiding waste.

[0009] To achieve the above objectives, the present invention provides a salt core molten salt casting device for aluminum pistons, comprising: a casting machine main unit, a salt core melting and holding furnace, and a hydraulic station arranged adjacent to each other. The hydraulic station is connected to the drive device of the casting machine main unit. The casting machine main unit includes: a machine bed; an opening and closing mechanism mounted on the machine bed worktable; and a top mold mechanism mounted on the machine bed. The top mold mechanism includes: a top mold column mounted on the machine bed; a top mold crossbeam connected to the top mold column; a top mold cylinder and two guide rods arranged adjacent to each other, mounted on the top mold crossbeam, with the tops of the two guide rods connected by a guide rod connecting block; and a top mold connecting plate connected to the guide rods. The connection includes a top mold connecting plate with a top mold cylinder connecting shaft, which is connected to the piston rod of the top mold cylinder; a top mold connecting rod installed below the top mold connecting plate to connect the top mold, and the top mold cylinder drives the top mold connecting rod and the top mold to perform up-and-down mold opening and closing actions; the opening and closing mechanism includes: two outer mold cylinders, respectively installed at the bottom of the top mold column; two outer mold slides, respectively connected to the outer mold cylinders through the outer mold cylinder connecting rods; two outer molds, respectively installed on the two outer mold slides; a core-pulling cylinder installed on the outer mold slide; a mold core slider connected to the core-pulling cylinder through the core-pulling cylinder connecting shaft; and a mold core installed on the mold core slider;

[0010] The top mold mechanism is equipped with a pressurizing device, which includes a normally open pneumatic valve and a normally closed pneumatic valve connected to the pressurizing port of the top mold, a filter and pressure reducing valve connected to external compressed air, and a first solenoid valve and a second solenoid valve connected between the filter and pressure reducing valve and the normally open and normally closed pneumatic valves. The first solenoid valve is connected to the normally open pneumatic valve, and the second solenoid valve is connected to the normally closed pneumatic valve. During molten salt pouring, neither the first nor the second solenoid valve is energized. Air inside the mold is discharged from the normally open pneumatic valve by the compression of the molten salt. After pouring is completed, the first solenoid valve is energized, controlling the normally closed pneumatic valve to open, allowing high-pressure air from the outside to enter the mold for pressurization. After pressurization for 10 seconds, the first solenoid valve is de-energized, controlling the normally closed pneumatic valve to close, ending the pressurization process. The second solenoid valve is then energized, controlling the normally open pneumatic valve to close, maintaining pressure until solidification.

[0011] Preferably, a wear-resistant inlay plate is installed on the bed worktable, and a wear-resistant strip is installed on the bottom of the outer mold slide, which slides on the wear-resistant inlay plate; a guide key is installed on the opening and closing center line of the bed worktable, and a groove matching the guide key is opened on the bottom of the outer mold slide to perform opening and closing actions along the guide key.

[0012] Preferably, an outer mold slide pressure plate is pressed onto the wear-resistant insert at the bottom of the outer mold slide, and the outer mold slide pressure plate is disposed on both sides of the outer mold slide to counteract the upward impact force of the two outer molds when the mold is closed.

[0013] Preferably, the opening and closing mechanism further includes: an outer mold travel switch stop block and an outer mold travel switch stop rod, which are installed on the outer mold slide; and an outer mold advance and retreat travel switch mounting bracket, which is installed on the bed worktable. An outer mold advance and retreat travel switch is installed on the outer mold advance and retreat travel switch mounting bracket to cooperate with the outer mold travel switch stop block and the outer mold travel switch stop rod to determine whether the left and right opening and closing actions of the outer mold are in place.

[0014] Preferably, the opening and closing mechanism further includes: a core-pulling limit switch stop block and a core-pulling limit switch stop rod that are configured to cooperate and are mounted on the core-pulling cylinder connecting shaft; a core-pulling limit switch mounting bracket that is mounted on the bed worktable, and a core-pulling limit switch is mounted on the core-pulling limit switch mounting bracket to cooperate with the core-pulling limit switch stop block and the core-pulling limit switch stop rod to determine whether the mold core movement is in place.

[0015] Preferably, the top mold connecting rod is connected to the top mold connecting plate by a spring.

[0016] Preferably, the top mold mechanism further includes: a top mold travel switch mounting bracket, mounted on the top mold crossbeam and adjacent to the guide rod connecting block; and two top mold up and down travel switches, mounted on the top mold travel switch mounting bracket and spaced vertically on the top mold travel switch mounting bracket, so as to determine whether the top mold has performed the up and down opening and closing action by detecting the guide rod connecting block.

[0017] Preferably, the overall structure of the top mold column is a welded closed box structure.

[0018] The present invention also provides a method for casting molten salt for aluminum piston cores, using the molten salt casting equipment for aluminum piston cores according to any of the above technical solutions, comprising the following steps:

[0019] The outer mold cylinder drives the outer mold cylinder connecting rod to drive the outer mold slide to slide inward, so as to close the outer mold. The outer mold stops when the outer mold travel switch detects that the outer mold travel switch block has reached the correct position.

[0020] The mold core slider is driven to slide inward by the connecting shaft of the core-pulling cylinder to close the mold core. The process stops when the core-pulling limit switch detects that the stop block has reached the correct position.

[0021] The top mold cylinder drives the top mold cylinder connecting shaft to move the top mold connecting plate downwards, which in turn drives the top mold connecting rod downwards, thus moving the top mold downwards. The movement stops when the guide rod connecting block is in place, detected by the upper and lower limit switches of the top mold below.

[0022] Molten salt is poured into a mold formed by the outer mold, mold core, and top mold in a salt core melting and holding furnace. During the pouring process, the pressure port of the top mold is connected to the atmosphere through a normally open air-controlled valve, and the air in the mold is discharged from the normally open air-controlled valve by the compression of the molten salt.

[0023] After the casting is completed, the normally closed pneumatic valve is energized and opened, and compressed air enters the mold through the valve group for pressurization. After pressurization for 10 seconds, the normally closed pneumatic valve is de-energized and closed, and the normally open pneumatic valve is energized and closed to maintain pressure until solidification.

[0024] The mold core slider is moved outward by the connecting shaft of the core-pulling cylinder driven by the core-pulling cylinder to open the mold core. The process stops when the core-pulling limit switch detects that the stop block has reached the correct position.

[0025] The top mold cylinder drives the top mold cylinder connecting shaft, which in turn drives the top mold connecting plate to move upward. This drives the top mold connecting rod to move upward, which in turn drives the top mold to move upward. The movement stops when the guide rod connecting block is in place, as detected by the upper top mold upper and lower limit switches.

[0026] The outer mold cylinder drives the outer mold cylinder connecting rod to drive the outer mold slide to slide outward, thus opening the outer mold. The outer mold stops when the outer mold travel limit switch detects that the outer mold travel limit switch block has reached the correct position.

[0027] Remove the solidified salt core blank.

[0028] Preferably, the operating pressure of the compressed air is 0.5 MPa ± 0.01 MPa.

[0029] The molten salt casting equipment and method for aluminum piston salt cores proposed in this invention have the following beneficial technical effects:

[0030] (1) The molten salt casting equipment and method for aluminum piston cores proposed in this invention uses molten salt casting to prepare salt cores, replacing the traditional method of salt powder pressing. This reduces dust pollution and thus reduces the harm to the operator's health, resulting in higher environmental protection and safety.

[0031] (2) The salt core casting equipment and method for aluminum pistons proposed in this invention only requires cutting off the riser after the salt core is cast and molded. Compared with the cumbersome pressing, drying, turning and drying processes in the prior art, the process is more simplified and the production efficiency is greatly improved and the labor intensity of workers is reduced.

[0032] (3) In the aluminum piston salt core molten salt casting equipment and method proposed in this invention, the riser of the salt core blank can be cut off and directly put into the melting and holding furnace for reuse, which reduces material waste and lowers product cost.

[0033] (4) The molten salt casting equipment and method for aluminum piston cores proposed in this invention can form molten salt in a mold, and achieve mass production of different styles of irregularly shaped salt cores according to the mold design. Since it does not require lathe turning in the traditional way, it breaks the limitation that the internal cooling channel of the piston can only be designed as a rotating body, which is conducive to improving the internal cooling effect of the piston.

[0034] (5) The aluminum piston salt core molten salt casting equipment proposed in this invention is equipped with a pressurizing device, which can discharge the internal air by pressure, reduce the occurrence of shrinkage cavities, and make the salt core blank more compact, thereby improving the quality of the salt core.

[0035] (6) The aluminum piston salt core molten salt casting equipment proposed in this invention is designed with wear-resistant inserts, wear-resistant strips, and guide keys, which can ensure the sliding stability of the outer mold slide and maintain linear sliding during opening and closing movements, thereby improving the accuracy of opening and closing the outer mold. The outer mold slide pressure plate is pressed on the wear-resistant strip at the bottom of the outer mold slide, which can counteract the upward impact force of the two outer molds during mold closing, further improving the stability of mold closing.

[0036] (7) The aluminum piston salt core molten salt casting equipment proposed in this invention further ensures the accuracy and stability of the opening and closing of the outer mold, the opening and closing of the mold core, and the up and down movement of the top mold by forming a switch block and a limit switch.

[0037] (8) In the aluminum piston salt core molten salt casting equipment proposed in this invention, the top mold connecting rod and the top mold connecting plate are connected by a spring, which can play a buffering and adjustment role when the top mold falls, ensuring the stability of the top mold when it falls.

[0038] (9) The overall structure of the top mold column in the aluminum piston salt core molten salt casting equipment proposed in this invention is a closed box structure welded together, which can withstand high force impact and meet the process requirements of the external mold cylinder opening and closing impact force.

[0039] Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. Attached Figure Description

[0040] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0041] Figure 1 A schematic diagram of the structure of a conventional salt core in the prior art is shown;

[0042] Figure 2 A schematic diagram of the structure of a four-column press in the prior art is shown;

[0043] Figure 3 A schematic diagram of the irregularly shaped salt core is shown;

[0044] Figure 4 A schematic diagram of a salt core casting apparatus for aluminum pistons according to an embodiment of the present invention is shown;

[0045] Figure 5 It shows Figure 4 Layout diagram of the salt core molten salt casting equipment for Chalco pistons;

[0046] Figure 6 It shows Figure 4 A schematic diagram of the top mold mechanism in the salt core molten salt casting equipment for Chalco pistons;

[0047] Figure 7 It shows Figure 6 Left view of the top mold mechanism;

[0048] Figure 8 It shows Figure 4 A schematic diagram of the opening and closing mechanism in the molten salt casting equipment for pistons of Chinalco;

[0049] Figure 9 It shows Figure 8 A top view of the opening / closing structure;

[0050] Figure 10 A schematic diagram of the pressurization control structure of the pressurization device is shown.

[0051] in, Figures 1 to 10 The correspondence between the reference numerals and components in the attached drawings is as follows:

[0052] 10 Four-column press, 102 Auxiliary oil tank, 104 Crossbeam, 106 Main cylinder, 108 Guide column, 110 Ejector cylinder, 112 Worktable, 114 Pressure plate;

[0053] 20. Casting machine main unit; 202. Bed; 2022. Bed worktable; 204. Opening and closing mechanism; 2041. External mold cylinder; 2042. External mold slide; 2043. External mold cylinder connecting rod; 2044. External mold; 2045. Core-pulling cylinder; 2046. Mold core slider; 2047. Mold core; 2048. Base plate; 2049. Stop ring; 2050. Wear-resistant inlay plate; 2051. Wear-resistant strip; 2052. Guide key; 2053. External mold slide pressure plate; 2054. External mold travel switch stop block; 2055. External mold travel switch stop rod; 2056. External mold forward and backward travel switch mounting bracket; 2057. External mold forward and backward travel switch; 2058. Core-pulling travel switch stop block; 2059. Core-pulling travel switch stop rod; 2 060 Core-pulling travel switch mounting bracket, 208 Top mold mechanism, 2081 Top mold column, 2082 Top mold crossbeam, 2083 Top mold cylinder, 2084 Guide rod, 2085 Guide rod connecting block, 2086 Top mold connecting plate, 2087 Top mold cylinder connecting shaft, 2088 Top mold connecting rod, 2089 Top mold, 2090 Spring, 2091 Copper sleeve, 2092 Guide copper sleeve, 2093 Top mold travel switch mounting bracket, 2094 Top mold upper and lower travel switches, 210 Pneumatic normally open valve, 212 Pneumatic normally closed valve, 214 Filter pressure reducing valve, 216 First solenoid valve, 217 Second solenoid valve, 218 Operation button box, 220 Button box bracket, 30 Salt core melting and holding furnace, 40 Hydraulic station. Detailed Implementation

[0054] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0055] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0056] The following is combined with Figures 4 to 10 The salt core casting apparatus for aluminum pistons according to an embodiment of the present invention will be described in detail.

[0057] like Figures 4 to 10 As shown, the aluminum piston salt core molten salt casting equipment according to an embodiment of the present invention includes a casting machine main unit 20, a salt core melting and holding furnace 30, and a hydraulic station 40 arranged adjacent to each other, with the specific layout as follows: Figure 5 As shown, the hydraulic station 40 is connected to the drive unit of the foundry machine main unit 20, ensuring the operation of the corresponding drive unit of the foundry machine main unit 20. For example... Figure 4As shown, the main casting machine 20 includes a bed 202, an opening and closing mechanism 204 mounted on the bed worktable 2022, and a top mold mechanism 208 mounted on the bed 202. This allows for the use of molten salt casting to prepare salt cores, reducing dust pollution and thus minimizing harm to operators, resulting in higher environmental friendliness and safety. The salt core can be used simply by cutting off the riser after casting. Compared to the cumbersome processes of pressing, drying, turning, and baking in existing technologies, the process is simplified, significantly improving production efficiency and reducing worker workload. The salt core blank can be directly reused in the melting and holding furnace after the riser is cut off, reducing material waste and lowering product costs. By changing the mold, different styles of irregularly shaped salt cores can be mass-produced, breaking the limitation of piston internal cooling channels only allowing for rotary designs and promoting improved piston internal cooling effects.

[0058] like Figure 6 and Figure 7 As shown, the top mold mechanism 208 includes a top mold column 2081, a top mold crossbeam 2082, a top mold cylinder 2083, guide rods 2084, a top mold connecting plate 2086, a top mold connecting rod 2088, and a top mold 2089. The top mold column 2081 is mounted on the bed 202. The top mold crossbeam 2082 is connected to the top mold column 2081 and mounted on top of the top mold column 2081. The top mold cylinder 2083 and two guide rods 2084 are mounted on the top mold crossbeam 2082. The guide rods 2084 are mounted above the top mold crossbeam 2082 via guide copper sleeves 2092 and can move up and down through the guide copper sleeves 2092. The tops of the guide rods 2084 are connected via guide rod connecting blocks 2085. The two guide rods 2084 move synchronously, and the guide connecting blocks avoid the position of the top mold cylinder 2083. The top mold connecting plate 2086 is connected to the guide rod 2084 and is located below the top mold crossbeam 2082. A top mold cylinder connecting shaft 2087 is installed on the top mold connecting plate 2086, and the top mold cylinder connecting shaft 2087 is connected to the piston rod of the top mold cylinder 2083. A top mold connecting rod 2088 is installed below the top mold connecting plate 2086, and the top mold 2089 is connected to the top mold. The top mold connecting plate 2086 can drive the top mold connecting rod 2088 and the top mold 2089 to perform up-and-down mold opening and closing actions. The piston rod of the top mold cylinder 2083, connected to the top mold cylinder connecting shaft 2087, drives the top mold connecting rod 2088 and the top mold 2089 to perform up-and-down mold opening and closing actions under the traction of the guiding mechanism composed of the guide rod connecting block 2085, the guide rod 2084, and the top mold connecting plate 2086.

[0059] Furthermore, such as Figure 6 and Figure 7As shown, a copper sleeve 2091 is provided at the connection between the top mold connecting rod 2088 and the top mold connecting plate 2086 to ensure the straightness of the vertical movement of the top mold connecting rod 2088. A spring 2090 is installed between the top mold connecting rod 2088 and the top mold connecting plate 2086. This can play a buffering and adjusting role when the top mold 2089 falls, ensuring the stability of the top mold 2089 during its descent.

[0060] Furthermore, such as Figure 6 and Figure 7 As shown, the top mold mechanism 208 also includes: a top mold travel switch mounting bracket 2093, and top mold up / down travel switches 2094. The top mold travel switch mounting bracket 2093 is mounted on the top mold crossbeam 2082, adjacent to the guide rod connecting block 2085. Two top mold up / down travel switches 2094 are mounted on the top mold travel switch mounting bracket 2093, spaced vertically on the bracket. When the top mold cylinder 2083 controls the top mold 2089 to open and close vertically, it obtains a positioning signal by contacting the guide rod connecting block 2085, thereby determining whether the top mold 2089 has completed its opening and closing motion. This ensures the accuracy and stability of the top mold 2089's opening and closing movement.

[0061] Furthermore, the overall structure of the top mold column 2081 is a closed box-type structure welded together, which can withstand high impact forces and meet the process requirements of the outer mold cylinder 2041 for mold opening and closing impact forces.

[0062] like Figure 8 and Figure 9 As shown, the opening and closing mechanism 204 includes: two outer mold cylinders 2041, two outer mold slides 2042, two outer molds 2044, two core-pulling cylinders 2045, two mold core sliders 2046, and a mold core 2047. The two outer mold cylinders 2041 are respectively installed at the bottom of the top mold column 2081. The outer mold cylinders 2041 are connected to the outer mold slides 2042 via outer mold cylinder connecting rods 2043. The two outer molds 2044 are respectively installed on the two outer mold slides 2042. The core-pulling cylinders 2045 are installed on the outer mold slides 2042, and the core-pulling cylinders 2045 are connected to the mold core sliders 2046 via core-pulling cylinder connecting shafts. The mold core 2047 is installed on the mold core sliders 2046. The outer mold cylinder 2041 drives the outer mold slide 2042 and the outer mold 2044 through the outer mold cylinder connecting rod 2043 to complete the mold opening and closing action. The core-pulling cylinder 2045 drives the mold core slider 2046 and the mold core 2047 through the core-pulling cylinder connecting shaft to complete the mold opening and closing action. This realizes the opening and closing of the outer mold 2044 and the mold core 2047.

[0063] Furthermore, such as Figure 8 and Figure 9As shown, a wear-resistant inlay plate 2050 is installed on the bed worktable 2022, and a wear-resistant strip 2051 is installed on the bottom of the outer mold slide 2042. The outer mold slide 2042 slides on the wear-resistant inlay plate 2050. A guide key 2052 is installed on the opening and closing center line of the bed worktable 2022, and a groove matching the guide key 2052 is opened on the bottom of the outer mold slide 2042 to perform opening and closing movements along the guide key 2052. This further ensures the sliding stability of the outer mold slide 2042 and maintains linear sliding during opening and closing movements, improving the accuracy of opening and closing the outer mold 2044.

[0064] Furthermore, such as Figure 8 and Figure 9 As shown, an outer mold slide pressure plate 2053 is pressed onto the wear-resistant insert 2051 at the bottom of the outer mold slide 2042. The outer mold slide pressure plate 2053 is located on both sides of the outer mold slide 2042, which can offset the upward impact force of the two outer molds 2044 when the mold is closed, and further improve the stability of the mold closing.

[0065] Furthermore, such as Figure 8 and Figure 9 As shown, the opening and closing mechanism 204 also includes: an outer mold travel switch stop block 2054, an outer mold travel switch stop rod 2055, an outer mold forward / reverse travel switch mounting bracket 2056, an outer mold forward / reverse travel switch 2057, a core-pulling travel switch stop block 2058, a core-pulling travel switch stop rod 2059, a core-pulling travel switch mounting bracket 2060, and a core-pulling travel switch, etc. The outer mold travel switch stop block 2054 and the outer mold travel switch stop rod 2055 are fitted together and installed on the outer mold slide table 2042. As the outer mold 2044 reciprocates, the outer mold forward / reverse travel switch mounting bracket 2056 is installed on the bed worktable 2022. The outer mold forward / reverse travel switch 2057 is installed on the outer mold forward / reverse travel switch mounting bracket 2056, which can trigger a positioning signal when contacted by the outer mold travel switch stop block 2054. The core-pulling limit switch stop block 2058 and the core-pulling limit switch stop rod 2059 are configured to work together and are installed on the connecting shaft of the core-pulling cylinder 2045. As the mold core 2047 reciprocates, the core-pulling limit switch mounting bracket 2060 is installed on the machine bed worktable 2022. The core-pulling limit switch is installed on the mounting bracket 2060, which can trigger a stop signal when it is contacted by the core-pulling limit switch stop block 2058. This further ensures the accuracy and stability of the opening and closing of the outer mold 2044 and the mold core 2047.

[0066] Furthermore, such as Figure 8 and Figure 9As shown, a stop ring 2049 is provided on the chassis 2048 on the bed worktable 2022, so as to better cooperate with the outer mold 2044 and the mold core 2047. The operation button box 218 is installed on the bed 202 via the button box bracket 220 for easy control and operation.

[0067] like Figure 10 As shown, the top mold mechanism 208 is equipped with a pressurizing device, which includes a normally open pneumatic valve 210 and a normally closed pneumatic valve 212 connected to the pressurizing port of the top mold 2089, a filter and pressure reducing valve 214 connected to external compressed air, and a first solenoid valve 216 and a second solenoid valve 217 connected between the filter and pressure reducing valve 214 and the normally open and normally closed pneumatic valves 210 and 212. The first solenoid valve 216 is connected to the normally open pneumatic valve 210, and the second solenoid valve 217 is connected to the normally closed pneumatic valve 212. During molten salt pouring, neither the first solenoid valve 216 nor the second solenoid valve 217 is energized. The pressurizing port of the top mold is connected to the atmosphere through the normally open pneumatic valve 210, allowing the compressed air during the pouring process to be discharged from the top of the mold from bottom to top. After casting, the first solenoid valve 216 is energized, controlling the normally closed pneumatic valve 212 to open. High-pressure air from the outside enters the mold through the valve assembly for pressurization. After 10 seconds of pressurization, the first solenoid valve 216 is de-energized, controlling the normally closed pneumatic valve 212 to close, ending the pressurization process. At this time, the second solenoid valve 216 is energized, controlling the normally open pneumatic valve 210 to close, maintaining pressure until solidification. Pressurization makes the salt core blank's microstructure finer and removes internal air, reducing shrinkage cavities. The pressurization system uses an air compressor to supply compressed air at a pressure of approximately 0.5 MPa.

[0068] In addition, the aluminum piston salt core molten salt casting equipment is designed with a matching hydraulic system, cooling system, protection system, electrical control system and mold. The electrical control system is the Siemens motion control module 1200, which uses a programmable logic controller (PLC) to control the action of each cylinder and valve group.

[0069] The method for casting molten salt for aluminum piston cores according to an embodiment of the present invention, using the molten salt casting equipment for aluminum piston cores described above, includes the following steps:

[0070] The outer mold cylinder drives the outer mold cylinder connecting rod to drive the outer mold slide to slide inward, so as to close the outer mold. The outer mold stops when the outer mold travel switch detects that the outer mold travel switch block has reached the correct position.

[0071] The mold core slider is driven to slide inward by the connecting shaft of the core-pulling cylinder to close the mold core. The process stops when the core-pulling limit switch detects that the stop block has reached the correct position.

[0072] The top mold cylinder drives the top mold cylinder connecting shaft to move the top mold connecting plate downwards, which in turn drives the top mold connecting rod downwards, thus moving the top mold downwards. The movement stops when the guide rod connecting block is in place, detected by the upper and lower limit switches of the top mold below.

[0073] Molten salt is poured into a mold formed by the outer mold, mold core, and top mold in a salt core melting and holding furnace. During the pouring process, the pressure port of the top mold is connected to the atmosphere through a normally open air-controlled valve, and the air in the mold is discharged from the normally open air-controlled valve by the compression of the molten salt.

[0074] After the casting is completed, the normally closed pneumatic valve is energized and opened, and compressed air enters the mold through the valve group for pressurization. After pressurization for 10 seconds, the normally closed pneumatic valve is de-energized and closed, and the normally open pneumatic valve is energized and closed to maintain pressure until solidification.

[0075] The mold core slider is moved outward by the connecting shaft of the core-pulling cylinder driven by the core-pulling cylinder to open the mold core. The process stops when the core-pulling limit switch detects that the stop block has reached the correct position.

[0076] The top mold cylinder drives the top mold cylinder connecting shaft, which in turn drives the top mold connecting plate to move upward. This drives the top mold connecting rod to move upward, which in turn drives the top mold to move upward. The movement stops when the guide rod connecting block is in place, as detected by the upper top mold upper and lower limit switches.

[0077] The outer mold cylinder drives the outer mold cylinder connecting rod to drive the outer mold slide to slide outward, thus opening the outer mold. The outer mold stops when the outer mold travel limit switch detects that the outer mold travel limit switch block has reached the correct position.

[0078] Remove the solidified salt core blank.

[0079] The molten salt casting method for aluminum piston cores described in this embodiment enables the preparation of cores using molten salt casting, reducing dust pollution and thus minimizing harm to operators, resulting in higher environmental friendliness and safety. The cast core can be used simply by cutting off the riser, a significantly simplified process compared to the cumbersome pressing, drying, turning, and baking processes of existing technologies. This greatly improves production efficiency and reduces worker workload. The cut-off riser of the core blank allows for direct reuse in the melting and holding furnace, reducing material waste and lowering product costs. Furthermore, by changing the mold, different shaped cores can be mass-produced, overcoming the limitation of rotating piston internal cooling channels and improving piston internal cooling performance.

[0080] Furthermore, the operating pressure of compressed air is 0.5MPa±0.01MPa, which can expel internal air through pressure, reduce the occurrence of shrinkage cavities, and make the salt core blank more compact, thereby improving the quality of the salt core.

[0081] In this invention, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0082] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0083] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0084] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A salt casting device for aluminum piston cores, characterized in that, include: The casting machine is equipped with an adjacent casting machine host, a salt core melting and holding furnace, and a hydraulic station. The hydraulic station is connected to the drive device of the casting machine host. The casting machine host includes: a machine bed; an opening and closing mechanism mounted on the machine bed's worktable; and a top mold mechanism mounted on the machine bed. The top mold mechanism includes: a top mold column mounted on the bed; a top mold crossbeam connected to the top mold column; a top mold cylinder and two guide rods mounted on the top mold crossbeam, with the tops of the two guide rods connected by a guide rod connecting block; a top mold connecting plate connected to the guide rods, a top mold cylinder connecting shaft provided on the top mold connecting plate, the top mold cylinder connecting shaft connected to the piston rod of the top mold cylinder; and a top mold connecting rod installed below the top mold connecting plate to connect the top mold, with the top mold cylinder driving the top mold connecting rod and the top mold to perform up-and-down mold opening and closing actions. The opening and closing mechanism includes: two outer mold cylinders, each installed at the bottom of the top mold column; two outer mold slides, each connected to the outer mold cylinders via connecting rods; two outer molds, each installed on one of the outer mold slides; a core-pulling cylinder, installed on the outer mold slides; a mold core slider, connected to the core-pulling cylinder via a connecting shaft; and a mold core, installed on the mold core slider. The top mold mechanism is equipped with a pressurizing device, which includes a normally open pneumatic valve and a normally closed pneumatic valve connected to the pressurizing port of the top mold, a filter and pressure reducing valve connected to external compressed air, and a first solenoid valve and a second solenoid valve connected between the filter and pressure reducing valve and the normally open and normally closed pneumatic valves. The first solenoid valve is connected to the normally open pneumatic valve, and the second solenoid valve is connected to the normally closed pneumatic valve. During molten salt pouring, neither the first nor the second solenoid valve is energized. Air inside the mold is discharged from the normally open pneumatic valve by the compression of the molten salt. After pouring is completed, the second solenoid valve is energized, controlling the normally closed pneumatic valve to open, allowing high-pressure air from the outside to enter the mold for pressurization. After pressurization for 10 seconds, the second solenoid valve is de-energized, controlling the normally closed pneumatic valve to close, ending the pressurization process. The first solenoid valve is then energized, controlling the normally open pneumatic valve to close, maintaining pressure until solidification.

2. The molten salt casting equipment for aluminum piston cores according to claim 1, characterized in that, Wear-resistant inlay plates are installed on the bed worktable, and wear-resistant strips are installed on the bottom of the outer mold slide. The outer mold slide slides on the wear-resistant inlay plates. A guide key is installed on the center line of the opening and closing type of the bed worktable, and a groove matching the guide key is opened at the bottom of the outer mold slide to perform opening and closing actions along the guide key.

3. The molten salt casting equipment for aluminum piston cores according to claim 2, characterized in that, The outer mold slide table has a wear-resistant insert at the bottom of the outer mold slide table, and the outer mold slide table pressure plate is set on both sides of the outer mold slide table to counteract the upward impact force of the two outer molds when the mold is closed.

4. The molten salt casting equipment for aluminum piston cores according to claim 1, characterized in that... The opening and closing mechanism further includes: The outer mold travel switch stop block and the outer mold travel switch stop rod are installed on the outer mold slide. An external mold advance / retreat limit switch mounting bracket is installed on the machine bed worktable. The external mold advance / retreat limit switch is installed on the mounting bracket to cooperate with the external mold limit switch stop block and the external mold limit switch stop rod to determine whether the left and right opening and closing actions of the external mold are in place.

5. The molten salt casting equipment for aluminum piston cores according to claim 4, characterized in that, The opening and closing mechanism also includes: The matching pull-out limit switch stop block and pull-out limit switch stop rod are installed on the pull-out cylinder connecting shaft; A core-pulling limit switch mounting bracket is installed on the machine bed worktable. The core-pulling limit switch is installed on the mounting bracket to cooperate with the core-pulling limit switch stop block and the core-pulling limit switch stop rod to determine whether the mold core movement is in place.

6. The molten salt casting apparatus for aluminum piston cores according to any one of claims 1 to 5, characterized in that, The top mold connecting rod is connected to the top mold connecting plate by a spring.

7. The molten salt casting equipment for aluminum piston cores according to claim 6, characterized in that, The top mold mechanism also includes: A top mold limit switch mounting bracket is installed on the top mold crossbeam and is arranged adjacent to the guide rod connecting block; Two upper and lower limit switches for the top mold are installed on the top mold limit switch mounting bracket and are spaced apart vertically on the top mold limit switch mounting bracket, so as to determine whether the upper and lower opening and closing action of the top mold is in place by detecting the guide rod connecting block.

8. The molten salt casting equipment for aluminum piston cores according to claim 7, characterized in that, The overall structure of the top mold column is a closed box-type structure welded together.

9. A method for casting molten salt for aluminum piston cores, characterized in that, The aluminum piston salt core molten salt casting equipment according to any one of claims 1 to 8 includes the following steps: The outer mold cylinder drives the outer mold cylinder connecting rod to drive the outer mold slide to slide inward, so as to close the outer mold. The outer mold stops when the outer mold travel switch detects that the outer mold travel switch block has reached the correct position. The mold core slider is driven to slide inward by the connecting shaft of the core-pulling cylinder to close the mold core. The process stops when the core-pulling limit switch detects that the stop block has reached the correct position. The top mold cylinder drives the top mold cylinder connecting shaft to move the top mold connecting plate downwards, which in turn drives the top mold connecting rod downwards, thus moving the top mold downwards. The movement stops when the guide rod connecting block is in place, detected by the upper and lower limit switches of the top mold below. Molten salt is poured into a mold formed by the outer mold, mold core, and top mold in a salt core melting and holding furnace. During the pouring process, the pressure port of the top mold is connected to the atmosphere through a normally open air-controlled valve, and the air in the mold is discharged from the normally open air-controlled valve by the compression of the molten salt. After the casting is completed, the normally closed pneumatic valve is energized and opened, and compressed air enters the mold through the valve group for pressurization. After pressurization for 10 seconds, the normally closed pneumatic valve is de-energized and closed, and the normally open pneumatic valve is energized and closed to maintain pressure until solidification. The mold core slider is moved outward by the connecting shaft of the core-pulling cylinder driven by the core-pulling cylinder to open the mold core. The process stops when the core-pulling limit switch detects that the stop block has reached the correct position. The top mold cylinder drives the top mold cylinder connecting shaft, which in turn drives the top mold connecting plate to move upward. This drives the top mold connecting rod to move upward, which in turn drives the top mold to move upward. The movement stops when the guide rod connecting block is in place, as detected by the upper top mold upper and lower limit switches. The outer mold cylinder drives the outer mold cylinder connecting rod to drive the outer mold slide to slide outward, thus opening the outer mold. The outer mold stops when the outer mold travel limit switch detects that the outer mold travel limit switch block has reached the correct position. Remove the solidified salt core blank.

10. The method for casting molten salt for aluminum piston cores according to claim 9, characterized in that, The operating pressure of the compressed air is 0.5MPa±0.01MPa.

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