Low-pressure casting equipment for iron casting

Abstract

The low-pressure casting equipment comprises a casting mold body, a lamp mold core is arranged on the surface of the casting mold body, a pouring gate is formed in the lamp mold core, meanwhile, four sets of guide columns are fixedly arranged on the surface of the casting mold body, and a surrounding type water cooling assembly is installed on the outer side of the casting mold body; the surrounding type water cooling assembly comprises two sets of first cooling cavities and second cooling cavities which are formed in the side wall of the casting mold body. According to the low-pressure casting equipment for cast iron, cooling water enters the first cooling cavity from the liquid inlet pipe and then sequentially enters the second cooling cavity; two groups of first cooling cavities and two groups of second cooling cavities are arranged and are distributed in an opposite state; cooling water can enter the casting mold body to quickly dissipate heat of a high-temperature casting part in the lamp mold core; by reducing the distance between the cooling medium and the high-temperature casting part, the high-efficiency heat dissipation work of the high-temperature casting part is completed.

Description

Technical Field

[0001] The present invention relates to the field of casting equipment, and specifically to a low-pressure casting equipment for cast iron. Background Art

[0002] Low-pressure casting is a method of filling a mold cavity with liquid metal under pressure to form a casting; because the pressure used is relatively low, it is called low-pressure casting. The molds used in low-pressure casting are divided into two categories: metal molds and non-metal molds; metal molds are mostly used for mass production of non-ferrous metal castings, and non-metal molds are mostly used for single-piece and small-batch production. For example, sand molds, graphite molds, ceramic molds, and investment casting shells can all be used for low-pressure casting, and sand molds are more commonly used in production; Regarding the patent of the casting mold, after retrieval, an auxiliary casting device for a casting mold disclosed in the publication number CN215315673U includes a workbench. A placement plate is arranged on the top of the workbench. Installation plates are fixedly connected to both sides of the top of the placement plate. First electric telescopic rods penetrate through the opposite sides of the installation plates. A first clamping plate is fixedly connected to the opposite sides of the first electric telescopic rods. A mold body is arranged on the top of the placement plate. Support columns are fixedly connected to both sides of the top of the workbench. A top plate is fixedly connected to the top of the support columns. A long hole is opened on the top of the top plate. A movable block is movably connected to the inner cavity of the long hole. A motor is fixedly connected to the top of the movable block; When the above device is actually used, after the device is formed inside the mold, the cooling and heat dissipation are generally natural heat dissipation, and its heat dissipation efficiency is low, resulting in a slow production speed. Summary of the Invention

[0003] The purpose of the present invention is to provide a low-pressure casting equipment for cast iron to solve the defects mentioned in the above background art.

[0004] To achieve the above purpose, a low-pressure casting equipment for cast iron is provided, including a casting mold body. A lamp mold core is opened on the surface of the casting mold body. A gate is arranged on the lamp mold core. At the same time, four groups of guide columns are fixedly arranged on the surface of the casting mold body. And a surrounding water-cooling component is installed outside the casting mold body. The surrounding water-cooling component includes two groups of first cooling cavities and second cooling cavities opened on the side wall of the casting mold body. A liquid blocking seat A and a liquid blocking seat C are hermetically installed outside the two groups of first cooling cavities respectively. A liquid blocking seat B and a liquid blocking seat D are hermetically installed outside the two groups of second cooling cavities respectively.

[0005] Preferably, four groups of ejector holes are evenly opened on the casting mold body. Ejector pins are inserted into the four groups of ejector holes. The bottoms of the ejector pins are fixedly arranged on the upper side surface of the mounting seat.

[0006] Preferably, the wrap-around water cooling assembly includes a liquid inlet pipe, a liquid baffle seat A, a first cooling chamber, a connecting pipe, a liquid baffle seat B, a second cooling chamber, a connecting tube, a liquid baffle seat C, a docking pipe, a liquid baffle seat D, and a liquid discharge pipe. One side of the surface of the liquid baffle seat A is provided with a liquid inlet pipe, and the other side of the surface of the liquid baffle seat A is provided with a connecting pipe.

[0007] Preferably, one end of the connecting pipe away from the liquid baffle seat A is fixedly connected to the liquid baffle seat B. One side of the surface of the liquid baffle seat B away from the connecting pipe is provided with a connecting tube. One side of the connecting tube away from the liquid baffle seat B is fixedly connected to the liquid baffle seat C.

[0008] Preferably, one side of the surface of the liquid baffle seat C away from the connecting tube is provided with a docking pipe. One end of the docking pipe away from the liquid baffle seat C is fixedly installed on the surface of the liquid baffle seat D. One side of the surface of the liquid baffle seat D away from the docking pipe is provided with a liquid discharge pipe.

[0009] Preferably, the connecting pipe, the connecting tube, and the docking pipe are all arranged in an "L" shape. Cooling chamber through pipes are installed on both sides of the inner walls of the connecting pipe, the connecting tube, and the docking pipe.

[0010] Preferably, the liquid inlet pipe is communicated with the liquid discharge pipe through the first cooling chamber, the connecting pipe, the second cooling chamber, the connecting tube, and the docking pipe in sequence. The liquid inlet pipe is communicated with the external cooling water inlet pipe.

[0011] Preferably, the liquid baffle seat A and the liquid baffle seat C are respectively located outside the opposite side walls of the casting mold body. The liquid baffle seat B and the liquid baffle seat D are respectively located outside the other two side walls of the casting mold body. And the four groups of liquid baffle seats are fixedly and sealedly connected to the side walls of the casting mold body through sealing rings.

[0012] Preferably, flow regulating valves are installed on both the liquid inlet pipe and the liquid discharge pipe. The flow regulating valves can accurately control the flow rate of the cooling water entering and flowing out of the wrap-around water cooling assembly.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: The cooling water enters the inside of the first cooling chamber from the liquid inlet pipe and then enters the inside of the second cooling chamber in sequence; Two groups of the first cooling chamber and the second cooling chamber are provided and are distributed in a relative state; The cooling water can enter the inside of the casting mold body to quickly dissipate heat from the high-temperature casting inside the lamp mold core; By reducing the distance between the cooling medium and the high-temperature casting, the efficient heat dissipation of the high-temperature casting is completed; The rapid heat dissipation can make the casting cool and solidify faster, shorten the molding cycle of a single casting, and thus increase the output per unit time. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a front view schematic diagram of the structure of the present invention; Figure 2 It is a bottom view of the structure of the invention; Figure 3 Side view of the invention structure; Figure 4 Top view of the invention structure; Figure 5 is Figure 1 bottom view of; Figure 6 is Figure 1 front view of; Figure 7 is Figure 6 rear view of.

[0015] Reference numerals in the figure: 1, casting mold body; 2, guide post; 3, lamp mold core; 4, gate; 5, ejector pin; 51, mounting seat; 6, circumferential water cooling assembly; 61, liquid inlet pipe; 62, liquid blocking seat A; 63, first cooling cavity; 64, connecting pipe; 65, liquid blocking seat B; 66, second cooling cavity; 67, connecting pipe; 68, liquid blocking seat C; 69, docking pipe; 70, liquid blocking seat D; 71, liquid discharge pipe. Specific implementation manner

[0016] Please refer to Figure 1-7 , the present invention provides a low-pressure casting device for cast iron, including a casting mold body 1. A lamp mold core 3 is provided on the surface of the casting mold body 1, and a gate 4 is arranged on the lamp mold core 3. At the same time, four groups of guide posts 2 are fixedly arranged on the surface of the casting mold body 1, and a circumferential water cooling assembly 6 is installed outside the casting mold body 1. The circumferential water cooling assembly 6 includes two groups of first cooling cavities 63 and second cooling cavities 66 opened on the side wall of the casting mold body 1. A liquid blocking seat A 62 and a liquid blocking seat C 68 are respectively and hermetically installed outside the two groups of first cooling cavities 63, and a liquid blocking seat B 65 and a liquid blocking seat D 70 are respectively and hermetically installed outside the two groups of second cooling cavities 66.

[0017] Working principle: When the low-pressure casting mold is closed, the molten aluminum rises through the liquid inlet pipe of the low-pressure casting mold into the pouring basin, and then enters each independent lamp mold core 3 through the gate 4; under the action of pressure, the molten aluminum gradually solidifies and forms in the cavity; the low-pressure forming work is completed; at this time, after the casting is formed inside the casting mold body 1, in order to improve the demoulding efficiency, since the first cooling cavity 63, the connecting pipe 64, the second cooling cavity 66, the connecting pipe 67, the docking pipe 69 and the drain pipe 71 are connected in series, and the liquid inlet pipe 61 is connected to the external cooling water inlet pipe, the cooling water enters the inside of the first cooling cavity 63 from the liquid inlet pipe 61 and then enters the inside of the second cooling cavity 66 in sequence; two groups of the first cooling cavity 63 and the second cooling cavity 66 are provided and are distributed in a relative state; the cooling water can enter the inside of the casting mold body 1 to quickly dissipate heat from the high-temperature casting inside the lamp mold core 3; by reducing the distance between the cooling medium and the high-temperature casting, the efficient heat dissipation of the high-temperature casting is completed; rapid heat dissipation can make the casting cool and solidify faster, shorten the forming cycle of a single casting, and thus increase the output per unit time; in large-scale production of lamps, the shorter forming cycle can make the production line flow faster, improving the overall production efficiency; uniform and rapid cooling helps to reduce stress concentration inside the casting, reducing the risk of deformation and cracking; for lamp mold cores, which have high requirements for dimensional accuracy and appearance quality, it can effectively ensure their dimensional accuracy and surface quality; timely heat dissipation can prevent the mold from suffering from a decline in material properties and increased wear due to being in a high-temperature state for a long time, extend the service life of the mold, reduce the replacement frequency and cost of the mold; prevent the mold from generating thermal fatigue cracks due to overheating, reduce the downtime for repairing and replacing the mold, and improve the continuity of production.

[0018] As a preferred embodiment, four ejector holes are evenly formed in the casting mold body 1, and ejector pins 5 are inserted into the interiors of the four ejector holes. The bottoms of the four ejector pins 5 are fixedly arranged on the upper surface of the mounting seat 51.

[0019] The four ejector holes are symmetrically distributed in the four corner regions of the casting mold body 1 to form uniform support force points, ensuring that the casting is balanced in force during the ejection process and avoiding deformation or damage caused by local stress concentration.

[0020] The ejector pin 5 adopts a stepped cross-sectional design (such as a cylinder with a gradually changing diameter). The diameter is smaller at the end close to the casting to reduce the ejection contact area and avoid leaving indentations on the casting surface; the diameter is larger at the connection with the mounting seat 51 at the bottom to enhance the structural strength.

[0021] The mounting seat 51 is rigidly connected to an external hydraulic or pneumatic driving device, and the synchronous ejection action of the four ejector pins 5 is realized through a synchronous hydraulic cylinder or air cylinder, and the ejection force error is controlled within ±5%.

[0022] The ejection stroke can be monitored in real time through a stroke sensor and linked with the temperature sensor of the water-cooling system. When the casting cools to a preset temperature (such as below 200 °C), the ejection action is automatically triggered to achieve intelligent production.

[0023] The inside of the ejector pin 5 is designed with a micro heat conduction channel (with a diameter of 23 mm), which is connected to the cooling water circulation system of the surrounding water-cooling component 6. During the ejection process, the ejector pin is continuously cooled to prevent thermal expansion jamming caused by long-term contact with the high-temperature mold.

[0024] An annular diversion groove is opened on the inner wall of the ejection hole, which forms a heat exchange network with the cooling cavity of the mold body 1 to further improve the local cooling efficiency before the casting is demolded.

[0025] As a preferred embodiment, the surrounding water-cooling component 6 includes a liquid inlet pipe 61, a liquid retaining seat A 62, a first cooling cavity 63, a connecting pipe 64, a liquid retaining seat B 65, a second cooling cavity 66, a connecting pipe 67, a liquid retaining seat C 68, a docking pipe 69, a liquid retaining seat D 70, and a liquid discharge pipe 71. One side of the surface of the liquid retaining seat A 62 is installed with the liquid inlet pipe 61, and the other side of the surface of the liquid retaining seat A 62 is installed with the connecting pipe 64.

[0026] The surrounding water-cooling component 6 is integrally surrounded around the casting mold body, and its various parts are orderly connected to form an efficient cooling liquid circulation system to achieve uniform cooling of the mold. This layout method can make the best use of the cooling effect of the cooling liquid, ensure that the mold maintains an appropriate temperature during the casting process, and improve the quality and production efficiency of the casting.

[0027] The cooling liquid enters the liquid retaining seat A 62 from the liquid inlet pipe 61. After being split by the liquid retaining seat A 62, it evenly flows into the first cooling cavity 63. In the first cooling cavity 63, the cooling liquid exchanges heat with the mold surface and absorbs the heat of the mold. Then, the cooling liquid flows into the liquid retaining seat B 65 through the connecting pipe 64 and enters the second cooling cavity 66 for further heat exchange. Next, the cooling liquid sequentially passes through the connecting pipe 67, the liquid retaining seat C 68, the docking pipe 69, and the liquid retaining seat D 70, and finally is discharged from the water-cooling component through the liquid discharge pipe 71. The whole process forms a continuous cooling liquid circulation system, continuously cooling the mold to ensure the temperature stability of the mold during the casting process.

[0028] As a preferred embodiment, one end of the connecting pipe 64 away from the liquid retaining seat A 62 is fixedly connected to the liquid retaining seat B 65. One side of the surface of the liquid retaining seat B 65 away from the connecting pipe 64 is installed with the connecting pipe 67, and one side of the connecting pipe 67 away from the liquid retaining seat B 65 is fixedly connected to the liquid retaining seat C 68.

[0029] Each component can be regarded as an independent module, and this modular design makes it more convenient during the production, installation and commissioning, and later maintenance processes. For example, if a liquid baffle seat is damaged, it can be replaced separately without affecting the normal operation of other components.

[0030] To prevent coolant leakage, effective sealing measures will be taken at the connection parts. When welding and connecting, the welding area can be ground and polished, and then sealant can be applied to further enhance the sealing performance. For flange connections, rubber sealing rings can be used, and by tightening with bolts, the sealing ring will deform, thus achieving a good sealing effect.

[0031] The coolant flows from the liquid baffle seat A62 through the connecting pipe 64 into the liquid baffle seat B65. The liquid baffle seat B65 plays a role in buffering and distributing the coolant, enabling the coolant to flow evenly into the connecting pipe 67. Then, the coolant enters the liquid baffle seat C68 through the connecting pipe 67 and flows to the subsequent cooling chambers. During the whole process, the flow of the coolant between the components is continuous and stable, ensuring the normal operation of the water cooling system.

[0032] The liquid baffle seat B65 and the liquid baffle seat C68 also play a role in pressure balance during the coolant flow process. When the coolant flows from one chamber into another, there may be pressure changes. The liquid baffle seat can adjust this pressure difference to ensure that the pressure of the coolant in the whole water cooling system is relatively stable, avoiding affecting the cooling effect due to excessive pressure fluctuations.

[0033] As a preferred implementation mode, a docking pipe 69 is installed on the side of the surface of the liquid baffle seat C68 away from the connecting pipe 67. One end of the docking pipe 69 away from the liquid baffle seat C68 is fixedly installed on the surface of the liquid baffle seat D70, and a drain pipe 71 is installed on the side of the surface of the liquid baffle seat D70 away from the docking pipe 69.

[0034] When the coolant flows from the connecting pipe 67 into the liquid baffle seat C68, the liquid baffle seat C68 plays a buffering role, slowing down the flow rate of the coolant to avoid pressure shock in the docking pipe 69 due to too fast flow rate. At the same time, it will guide the coolant so that the coolant can flow evenly and stably into the docking pipe 69.

[0035] A simple filtering device, such as a filter screen, can be set inside the liquid baffle seat C68. The filter screen can intercept impurities that may be carried in the coolant, such as metal chips and oxides generated during the casting process, to prevent these impurities from entering the docking pipe 69 and subsequent components, causing pipe blockage or equipment damage.

[0036] The docking pipe 69, as a key component connecting the liquid baffle seat C68 and the liquid baffle seat D70, its main function is to transfer the coolant from the liquid baffle seat C68 to the liquid baffle seat D70. The pipe diameter and length of the docking pipe 69 are designed according to the flow rate and pressure requirements of the entire water cooling system to ensure that the coolant can pass through smoothly.

[0037] Considering that the mold may undergo a certain amount of thermal deformation during the casting process, the docking pipe 69 can adopt a material or structural design with a certain degree of flexibility. For example, using a corrugated pipe structure, it can compensate for the pipe displacement caused by mold deformation to a certain extent and avoid damage caused by rigid pipe connection.

[0038] The liquid baffle seat D70 performs the final sorting and adjustment on the coolant to be discharged. It can further balance the pressure and flow rate of the coolant, enabling the coolant to flow into the drain pipe 71 in a stable state.

[0039] A liquid level sensor can be installed on the liquid baffle seat D70 to monitor the liquid level of the coolant in real time. When the liquid level is too high or too low, the sensor can send a signal to remind the operator to adjust the coolant supply in a timely manner to ensure the normal operation of the water cooling system. The drain pipe 71 discharges the coolant that has undergone the cooling cycle from the wrap-around water cooling assembly 6. The outlet of the drain pipe 71 is usually connected to a coolant recovery device or a cooling equipment so that the coolant can be processed and recycled.

[0040] A flow control valve can be installed on the drain pipe 71 to control the discharge flow rate of the coolant by adjusting the opening of the valve. In this way, according to the actual cooling requirements of the mold, the circulation speed of the coolant can be flexibly adjusted to improve the cooling efficiency.

[0041] After the coolant absorbs the heat of the mold after passing through parts such as the first cooling chamber 63 and the second cooling chamber 66, it flows into the liquid baffle seat C68 through the connecting pipe 64, the liquid baffle seat B65, and the connecting pipe 67 in sequence. After buffering, filtering, and guiding in the liquid baffle seat C68, the coolant enters the liquid baffle seat D70 through the docking pipe 69. The liquid baffle seat D70 performs the final sorting and adjustment on the coolant to ensure that the coolant is discharged through the drain pipe 71 in a stable state. During the whole process, each component cooperates with each other to form a complete coolant circulation system to achieve continuous cooling of the mold.

[0042] As a preferred implementation manner, the connecting pipe 64, the connecting pipe 67, and the docking pipe 69 are all set in an "L" shape, and cooling chamber through pipes are installed on both sides of the inner walls of the connecting pipe 64, the connecting pipe 67, and the docking pipe 69.

[0043] As a preferred embodiment, the liquid inlet pipe 61 is sequentially communicated with the liquid discharge pipe 71 through the first cooling chamber 63, the connecting pipe 64, the second cooling chamber 66, the connecting pipe 67, and the docking pipe 69. The liquid inlet pipe 61 is communicated with the external cooling water inlet pipe.

[0044] The "L"-shaped connecting pipe 64, connecting pipe 67, and docking pipe 69 are combined with the communication path of the coolant, making the entire surrounding water-cooling assembly 6 more compact in spatial layout. This design can make full use of the limited space around the mold, avoid the lengthiness and chaos of the pipelines, reduce the floor area of the equipment, and at the same time facilitate the installation and maintenance of the equipment.

[0045] The liquid inlet pipe 61 is sequentially communicated with the liquid discharge pipe 71 through the first cooling chamber 63, the connecting pipe 64, the second cooling chamber 66, the connecting pipe 67, and the docking pipe 69, forming a complete and smooth coolant circulation loop. The coolant enters the liquid inlet pipe 61 from the external cooling water inlet pipe, then flows through each cooling chamber and connecting pipeline in an orderly manner, and finally discharges from the liquid discharge pipe 71, ensuring that the coolant can continuously and stably cool the mold.

[0046] When the coolant flows through the first cooling chamber 63 and the second cooling chamber 66, it conducts sufficient heat exchange with the mold surface, absorbing the heat generated by the mold during the casting process. The "L"-shaped connecting pipeline can not only change the flow direction of the coolant, increase the turbulence degree of the coolant, and improve the heat exchange efficiency, but also the cooling chamber through pipes on both sides of the inner wall of the pipeline further increase the contact area between the coolant and the pipeline wall, strengthening the heat exchange effect. This multi-stage cooling method can more effectively reduce the temperature of the mold and ensure the quality of the casting.

[0047] In the entire coolant circulation loop, the reasonable connection of each component helps to achieve pressure balance and flow control. The connection between the liquid inlet pipe 61 and the external cooling water inlet pipe provides a stable coolant supply pressure for the system, and the design of the "L"-shaped pipeline and the cooling chamber through pipes can adjust the flow rate and pressure of the coolant to a certain extent, ensuring that the coolant is evenly distributed in each cooling chamber and pipeline, and avoiding local overheating or overcooling.

[0048] As a preferred embodiment, the liquid retaining seat A62 and the liquid retaining seat C68 are respectively located on the outer sides of the opposite side walls of the casting mold body 1, and the liquid retaining seat B65 and the liquid retaining seat D70 are respectively located on the outer sides of the other two side walls of the casting mold body 1. And the four groups of liquid retaining seats are fixedly and hermetically connected to the side walls of the casting mold body 1 through sealing rings.

[0049] The liquid baffle seat A62 and the liquid baffle seat C68 are respectively placed outside the opposite side walls of the casting mold body 1, and the liquid baffle seat B65 and the liquid baffle seat D70 are respectively located outside the other two side walls. This layout enables the circumferential water-cooling assembly to cool the casting mold body in all directions. When the coolant circulates in each liquid baffle seat and the connected cooling cavities and pipes, it can evenly take away the heat generated in each part of the mold, effectively avoiding casting quality problems caused by excessive local temperature, such as thermal stress concentration, deformation, etc., and improving the overall quality and dimensional accuracy of the casting.

[0050] All four groups of liquid baffle seats are fixedly and sealedly connected to the side walls of the casting mold body 1 through sealing rings. This design can effectively prevent coolant leakage. Coolant leakage will not only lead to a decrease in cooling efficiency and affect the cooling effect of the mold, but may also cause damage to the surrounding equipment and environment. For example, coolant leakage onto electrical equipment may cause a short-circuit fault, and leakage onto the working site will make the ground slippery, posing a safety hazard.

[0051] As a preferred embodiment, flow regulating valves are installed on both the inlet pipe 61 and the outlet pipe 71. The flow regulating valves can accurately control the flow rate of the cooling water entering and flowing out of the circumferential water-cooling assembly 6.

[0052] The flow regulating valve adopts a high-precision electric or pneumatic actuator. By adjusting the valve opening (0 - 100%), linear control of the cooling water flow rate in the range of 0.5 - 5 m / s can be achieved. For example, for thin-walled lamp castings, the flow rate can be increased to 3.5 m / s in the initial cooling stage to rapidly cool down, and decreased to 1.2 m / s in the later solidification stage to avoid stress concentration.

[0053] The regulating valve is linked with a temperature sensor (such as a thermocouple), and the opening is adjusted in real time through the PID algorithm. When the surface temperature of the mold exceeds the preset threshold (such as 300 °C), the valve automatically opens wider; when the temperature is lower than 150 °C, it gradually closes smaller to ensure that the cooling rate dynamically matches the solidification process of the casting.

Claims

1. A low-pressure casting device for cast iron, comprising a casting mold body (1), characterized in that: The surface of the casting mold body (1) is provided with a lamp mold core (3), and a gate (4) is provided on the lamp mold core (3). Meanwhile, four groups of guide columns (2) are fixedly provided on the surface of the casting mold body (1), and a surrounding water cooling component (6) is installed on the outer side of the casting mold body (1). The surrounding water cooling component (6) comprises two groups of first cooling cavities (63) and second cooling cavities (66) provided on the side wall of the casting mold body (1). The outer sides of the two groups of first cooling cavities (63) are respectively sealed with a liquid retaining seat A (62) and a liquid retaining seat C (68), and the outer sides of the two groups of second cooling cavities (66) are respectively sealed with a liquid retaining seat B (65) and a liquid retaining seat D (70).

2. A low pressure casting equipment for cast iron according to claim 1, characterized in that: The casting mold body (1) is evenly provided with four groups of ejection holes, and the interiors of the four groups of ejection holes are all penetrated by ejection columns (5), and the bottoms of the four groups of ejection columns (5) are all fixedly arranged on the upper side surface of the mounting seat (51).

3. The low pressure casting equipment for cast iron according to claim 1, characterized in that: The surround-type water cooling assembly (6) comprises a liquid inlet pipe (61), a liquid retaining seat A (62), a first cooling cavity (63), a connecting pipe (64), a liquid retaining seat B (65), a second cooling cavity (66), a connecting pipe (67), a liquid retaining seat C (68), a butt-joint pipe (69), a liquid retaining seat D (70) and a liquid discharge pipe (71); the liquid inlet pipe (61) is installed on one side of the surface of the liquid retaining seat A (62), and the connecting pipe (64) is installed on the other side of the surface of the liquid retaining seat A (62).

4. A low pressure casting equipment for cast iron according to claim 3, characterized in that: One end of the connecting tube (64) away from the liquid retaining seat A (62) is fixedly connected to the liquid retaining seat B (65); a connecting tube (67) is installed on the side of the surface of the liquid retaining seat B (65) away from the connecting tube (64); and a side of the connecting tube (67) away from the liquid retaining seat B (65) is fixedly connected to the liquid retaining seat C (68).

5. The low pressure casting equipment for cast iron according to claim 4, characterized in that: A butt joint pipe (69) is installed on a side of the surface of the liquid retaining seat C (68) away from the connecting pipe (67); an end of the butt joint pipe (69) away from the liquid retaining seat C (68) is fixedly installed on the surface of the liquid retaining seat D (70); and a liquid discharge pipe (71) is installed on a side of the surface of the liquid retaining seat D (70) away from the butt joint pipe (69).

6. The low pressure casting equipment for cast iron according to claim 3, characterized in that: The connecting pipe (64), the connecting pipe (67) and the butt-joint pipe (69) are all arranged in an "L" shape, and cooling cavity through pipes are installed on both sides of the inner walls of the connecting pipe (64), the connecting pipe (67) and the butt-joint pipe (69).

7. A low pressure casting equipment for cast iron according to any one of claims 1 or 3, characterized in that: The liquid inlet pipe (61) is connected to the liquid discharge pipe (71) in sequence through the first cooling chamber (63), the connecting pipe (64), the second cooling chamber (66), the connecting pipe (67), the butt joint pipe (69), and the liquid inlet pipe (61) is connected to an external cooling water inlet pipe.

8. The low pressure casting equipment for cast iron according to claim 7, characterized in that: The liquid retaining seat A (62) and the liquid retaining seat C (68) are respectively located on the outside of two opposite side walls of the casting mold body (1), and the liquid retaining seat B (65) and the liquid retaining seat D (70) are respectively located on the outside of the other two side walls of the casting mold body (1), and the four sets of liquid retaining seats are fixedly sealed and connected to the side walls of the casting mold body (1) through sealing rings.

9. The low pressure casting equipment for cast iron according to claim 8, characterized in that: The liquid inlet pipe (61) and the liquid outlet pipe (71) are both installed with flow regulating valves, which can accurately control the flow rate of cooling water entering and flowing out of the surround water cooling component (6).

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