Special precoated sand for water-cooled exhaust manifold

Abstract

The invention relates to precoated sand special for a water-cooled exhaust manifold applied to the related technical field of precoated sand production, a collapsing agent is added into crude sand together with phenolic resin, the precoated sand which is high in strength, low in gas-forming and easy to collapse can be obtained, the requirements of the water-cooled exhaust manifold are met, and in addition, in the preparation process, the collapsing agent is added into the crude sand, so that the water-cooled exhaust manifold is prepared. Through the arrangement of the two-stage cooling unit outside the sand mixer, precoated sand in the sand mixer body can be subjected to single-stage cooling aiming at the bottom of the sand mixer body according to actual requirements in the earlier stage of precoated sand preparation, and through the arrangement of the selective connecting piece, the circumferential cooling frame can be controlled to be connected into the cooling disc to be connected with the cooling disc into a whole in the later stage of preparation and when cooling and discharging are waited; the precoated sand in the sand mixer body is jointly subjected to two-stage cooling, the heat exchange area between the two-stage cooling unit and crude sand is greatly enlarged, the speed of reducing the precoated sand to the target temperature is effectively increased, the discharging time is effectively shortened, and the production efficiency is greatly improved for a large amount of precoated sand.

Description

Technical Field

[0001] The present invention relates to coated sand, and in particular to coated sand specially used for water-cooled exhaust manifolds, which is applied in the technical field related to the production of coated sand. Background Art

[0002] The water-cooled exhaust manifold transfers the heat of the engine exhaust to the cooling water through the cooling effect of water, thereby reducing the exhaust temperature, reducing environmental pollution, and improving the efficiency of the engine. The water-cooled exhaust manifold is based on the original exhaust pipe, but changes the structure of the exhaust pipe, with water running in the interlayer, one end of which is connected to the engine cylinder block, and the other end is connected to the water tank.

[0003] Chinese patent CN106270408A discloses a mold for a turbine-connected exhaust manifold sand core and a manufacturing process for the sand core, which solves the technical problems of low strength of the combined sand core, large error after combination, and difficulty in ensuring the processing size, and produces a combined sand core box, providing a turbine-connected exhaust pipe sand core, so that the sand core can withstand the impact of high-temperature molten iron, is not easy to break, and has a small deformation, which solves the problem of difficulty in ensuring the subsequent processing size; the flow channel sand core made of general coated sand cannot withstand the high temperature impact of ≥1500℃, and the sand core deformation problem; it is worthy of application and promotion. However, the coated sand used for sand core preparation in the above patent does not take into account the gas emission and collapsibility during preparation. Generally speaking, in order to improve the strength of the sand core, the coated sand is required to have the characteristics of low gas emission, high strength, and easy collapsibility.

[0004] In order to meet the above needs, disintegrating agents are generally added to make the coated sand have the characteristics of low gas emission, high strength, and easy disintegration. For example, Chinese patent CN104226888B discloses an easily disintegratable coated sand and its preparation method; however, the coated sand has high requirements on temperature during the production process, and the sand needs to be heated first so that it can be produced while maintaining a certain temperature. During this process, when the ingredients are mixed in the sand mixer, the sand is continuously cooled naturally. When the temperature drops to a suitable temperature, different ingredients are added and mixed. After the mixing and grinding is completed, it is necessary to wait for the sand to cool down naturally to a suitable temperature again before the material can be discharged to complete the preparation. The natural cooling rate of the whole process is relatively slow, which seriously affects the production efficiency for large-scale coated sand production. Summary of the invention

[0005] In view of the above-mentioned prior art, the technical problem to be solved by the present invention is that the natural cooling method adopted in the existing coated sand preparation process seriously affects the production efficiency of the coated sand.

[0006] In order to solve the above problems, the present invention provides a special coated sand for water-cooled exhaust manifold, comprising the following ingredients in parts by weight: 100% of raw sand, 1.2-1.8% of phenolic resin, 5% of calcium stearate, 12-15% of hexamethylenetetramine, and 0.5-1% of disintegrator; The method for preparing coated sand for water-cooled exhaust manifold according to the ingredients includes the following steps: S1. Put the quantitative raw sand heated to 125-130℃ into the sand mixer for uniform mixing; The sand mixer includes a sand mixer body with a control center, the middle of the sand mixer body is connected to a rotating shaft through an electric turntable, a rolling hammer and a stirring blade are installed on the outer end of the rotating shaft, and a two-stage cooling unit is arranged outside the sand mixer body, and the two-stage cooling unit includes a cooling plate fixedly connected to the bottom of the sand mixer body and a circumferential cooling frame sleeved outside the sand mixer body, and an optional part is arranged between the circumferential cooling frame and the cooling plate, and a liquid inlet pipe and a liquid discharge pipe are fixedly connected to the lower end of the cooling plate; S2, then add quantitative phenolic resin and disintegrating agent and mix and grind for 40-50 seconds; S3, at this time, start the double-stage cooling unit of the sand mixer, perform bottom single-stage cooling on the raw sand, then add calcium stearate and mix and grind, when the raw sand is cooled to 100-110°C, add the urotropine aqueous solution and mix and grind for 10 seconds; S4. Add calcium stearate for a second time and mix and grind for 30-50 seconds. At this time, connect the circumferential cooling rack to the bottom cooling unit through the optional parts, so that the two are linked, and the coolant is filled in a synchronous cycle to perform double-stage cooling on the raw sand. When the temperature drops below 80°C, the finished product is discharged from the sand mixer and crushed and screened to obtain coated sand.

[0007] In the above-mentioned coated sand specially used for water-cooled exhaust manifold, by adding a disintegrating agent to the original sand together with phenolic resin, a high-strength, low-gassing and easy-to-disintegrate coated sand can be obtained, which meets the needs of water-cooled exhaust manifolds. In addition, during the preparation process, through the setting of a two-stage cooling unit, the original sand can be dissipated in a targeted manner, thereby effectively accelerating the drop in its temperature and accelerating the preparation efficiency of the coated sand.

[0008] As a further improvement of the present application, the particle size of the raw sand is 40-70 mesh, and the disintegrating agent is calcium peroxide.

[0009] As a further improvement of the present application, the circumferential cooling rack includes an upper ring body connected to the outside of the sand mixer body and a plurality of evenly distributed lower extension plates fixedly connected to the lower end of the upper ring body. Both the upper ring body and the lower extension plates are hollow structures, and a plurality of liquid guide plates corresponding to the plurality of lower extension plates are fixedly connected to the top end of the upper ring body. The liquid guide plates extend into the lower extension plates, and the bottom of the liquid guide plates does not contact the bottom of the lower extension plates.

[0010] As a further improvement of the present application, the optional connection part includes a selection block fixed and communicated with the lower end of the upper ring body and an L-shaped hollow block fixedly connected to the outer end of the cooling plate, the L-shaped hollow block is located directly below the selection block, the upper end of the L-shaped hollow block is fixedly connected to two fixed interfaces, one-way valves are installed in the two fixed interfaces, the lower end of the selection block is fixedly connected to two movable interfaces that match the two fixed interfaces respectively, the inside of the movable interface is fixedly connected to a core push rod through a connecting rod, and the lower end of the core push rod extends to below the movable interface.

[0011] As a further improvement of the present application, a flat partition is fixedly connected to the inside of the cooling plate, and the end of the flat partition extends into the L-shaped hollow block and is fixedly connected to the inner wall of the L-shaped hollow block on the side away from the cooling plate. The flat partition divides the L-shaped hollow block and the inside of the cooling plate into two cavities, and the two cavities on the same side of the L-shaped hollow block and the cooling plate are connected, and the two fixed interfaces, the liquid inlet pipe and the liquid discharge pipe are respectively connected to the four cavities, and an exchange hole is drilled at the end of the flat partition away from the L-shaped hollow block, and an electromagnetic valve is installed at the exchange hole.

[0012] As a further improvement of the present application, the selection block includes a fixed liquid guide plate fixed and communicated with the upper ring body, a dynamic liquid guide plate connected to the dynamic interface, and two bellows respectively connected between the fixed liquid guide plate and the dynamic liquid guide plate. The lower end of the dynamic liquid guide plate is also fixedly connected to an elastic pad, and the two dynamic interfaces are fixedly penetrated through the elastic pad. Two independent water guide cavities are arranged inside the fixed liquid guide plate and the dynamic liquid guide plate. The two bellows are respectively connected to the two water guide cavities on the same side of the fixed liquid guide plate and the dynamic liquid guide plate. Two electric push rods are also installed between the outer ends of the fixed liquid guide plate and the dynamic liquid guide plate, and the solenoid valve and the electric push rod are both connected to the control center signal.

[0013] As another improvement of the present application, the fixed interface includes an inner fixed layer fixedly connected to the L-shaped hollow block, two outer jacket layers sleeved outside the inner fixed layer, and a measuring sleeve fixedly connected between the two outer jacket layers, the lower outer jacket layer is fixedly connected to the L-shaped hollow block, and the upper outer jacket layer is higher than the inner fixed layer, a waterproof pipe is fixedly connected between the two measuring sleeves outside the two fixed interfaces, a warning light is also installed on the L-shaped hollow block, two wires are led out of the circuit where the warning light is located, and the two wires extend into the waterproof pipe and do not touch each other.

[0014] As another improved supplement to the present application, the measuring sleeve includes a base plate, an air cushion layer fixedly connected to the upper end of the base plate, and a water cushion fixedly attached to the upper surface of the base plate. The outer diameters of the base plate and the air cushion layer are larger than the outer diameter. The water cushion is located inside the air cushion layer. A liquid guide tube is fixedly connected to the outer end of the water cushion. The liquid guide tube fixedly passes through the air cushion layer and is connected to the water-proof pipe.

[0015] As another improved supplement of the present application, the water-proof tube includes two liquid storage sections and a binding section fixedly connected between the two liquid storage sections, two tightly attached elastic water-proof layers are fixedly connected in the binding section, and the ends of the two wires extend from both sides into the two elastic water-proof layers and are fixedly attached to the inner walls of the elastic water-proof layers.

[0016] In summary, by adding disintegrating agent to the raw sand together with phenolic resin, high-strength, low-gassing and easy-to-disintegrate coated sand can be obtained, which meets the needs of water-cooled exhaust manifolds. In addition, during the preparation process, by setting a two-stage cooling unit outside the sand mixer, in the early stage of the preparation of the coated sand, the coated sand inside the bottom of the sand mixer body can be cooled in a single stage according to actual needs. In the later stage of the preparation, when waiting for cooling and discharging, the circumferential cooling rack can be controlled to access the cooling plate through the setting of optional parts, so that the two are connected as a whole, and then the coated sand in the sand mixer body is cooled in two stages together, thereby greatly expanding the heat exchange area between the two-stage cooling unit and the raw sand, thereby effectively accelerating the speed at which the coated sand drops to the target temperature, effectively shortening the discharging time, and greatly accelerating the production efficiency for large volumes of coated sand. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the main process of the first implementation method of this application; Figure 2 A three-dimensional diagram of a sand mixer according to a first embodiment of the present application; Figure 3 A three-dimensional diagram of a two-stage cooling unit according to a first embodiment of the present application; Figure 4 This is a front view of the circumferential cooling rack portion of the first embodiment of the present application; Figure 5 This is a schematic diagram of the coolant flow direction at the cooling disk when the circumferential cooling rack of the first embodiment of the present application is connected to the cooling disk; Figure 6 This is a schematic diagram of the coolant flow direction at the cooling disk when the circumferential cooling rack of the first embodiment of the present application is not connected to the cooling disk; Figure 7 This is a comparison diagram of the optional component in the first embodiment of the present application in the connected and separated states; Figure 8 This is a three-dimensional diagram of a sand mixer after the circumferential cooling rack of the first embodiment of the present application is connected to the cooling plate; Fig. 9 A cross-sectional view of a fixed interface portion of a second embodiment of the present application; Fig.10 This is a cross-sectional view of a measuring sleeve according to a second embodiment of the present application; Fig.11 This is a cross-sectional view of the water-proof pipe portion when the two wires of the second embodiment of the present application are not connected; Fig.12 This is a cross-sectional view of the water-proof pipe portion after two wires are connected in the second embodiment of the present application.

[0018] Description of the numbers in the figure: 1 sand mixer body, 2 rotating shaft, 3 rolling hammer, 4 stirring blade, 5 cooling plate, 51 L-shaped hollow block, 52 fixed interface, 53 flat partition, 54 exchange hole, 501 liquid inlet pipe, 502 liquid discharge pipe, 521 inner fixed layer, 522 outer jacket layer, 61 upper ring body, 62 lower extension piece, 63 liquid guide plate, 7 optional block, 71 fixed liquid guide plate, 72 dynamic liquid guide plate, 73 bellows, 74 dynamic interface, 701 electric push rod, 702 core push rod, 8 measuring sleeve, 81 bottom plate, 82 air cushion layer, 83 water cushion, 801 liquid guide pipe, 9 water avoidance pipe, 91 liquid storage section, 92 restraint section, 93 elastic water avoidance layer. DETAILED DESCRIPTION

[0019] Two implementation modes of the present application are described in detail below with reference to the accompanying drawings.

[0020] The first implementation method: Figure 1 It is shown that a coated sand specially used for water-cooled exhaust manifold comprises the following ingredients by weight: 100% of raw sand, 1.2-1.8% of phenolic resin, 5% of calcium stearate, 12-15% of hexamethylenetetramine, and 0.5-1% of disintegrator, wherein the particle size of the raw sand is 40-70 meshes; The method for preparing coated sand for water-cooled exhaust manifold according to the above ingredients comprises the following steps: S1. Put the quantitative raw sand heated to 125-130℃ into the sand mixer for uniform mixing; S2, then add a quantitative phenolic resin and a disintegrating agent and mix and grind for 40-50 seconds, wherein the disintegrating agent is calcium peroxide; S3, at this time, start the double-stage cooling unit of the sand mixer, perform bottom single-stage cooling on the raw sand, then add calcium stearate and mix and grind, when the raw sand is cooled to 100-110°C, add the urotropine aqueous solution and mix and grind for 10 seconds; S4. Add calcium stearate for a second time and mix and grind for 30-50 seconds. At this time, connect the circumferential cooling rack to the bottom cooling unit through the optional parts, so that the two are linked, and the coolant is filled in a synchronous cycle to perform double-stage cooling on the raw sand. When the temperature drops below 80°C, the finished product is discharged from the sand mixer and crushed and screened to obtain coated sand.

[0021] In the above-mentioned coated sand specially used for water-cooled exhaust manifold, by adding a disintegrating agent to the original sand together with phenolic resin, a high-strength, low-gassing and easy-to-disintegrate coated sand can be obtained, which meets the needs of water-cooled exhaust manifolds. In addition, during the preparation process, through the setting of a two-stage cooling unit, the original sand can be dissipated in a targeted manner, thereby effectively accelerating the drop in its temperature and accelerating the preparation efficiency of the coated sand.

[0022] Among them, Figure 2-3 The sand mixer includes a sand mixer body 1 with a control center. The middle of the sand mixer body 1 is connected to a rotating shaft 2 through an electric turntable. A rolling hammer 3 and a stirring blade 4 are installed on the outer end of the rotating shaft 2. A two-stage cooling unit is arranged outside the sand mixer body 1. The two-stage cooling unit includes a cooling plate 5 fixedly connected to the bottom of the sand mixer body 1 and a circumferential cooling frame sleeved outside the sand mixer body 1. An optional part is arranged between the circumferential cooling frame and the cooling plate 5. The lower end of the cooling plate 5 is fixedly connected to a liquid inlet pipe 501 and a liquid discharge pipe 502; the optional part includes It includes a selection block 7 fixed and communicated with the lower end of the upper ring body 61 and an L-shaped hollow block 51 fixedly connected to the outer end of the cooling plate 5. The L-shaped hollow block 51 is located directly below the selection block 7. The upper end of the L-shaped hollow block 51 is fixedly connected to two fixed interfaces 52, and one-way valves are installed in the two fixed interfaces 52. The lower end of the selection block 7 is fixedly connected to two movable interfaces 74 that match the two fixed interfaces 52 respectively. The inside of the movable interface 74 is fixedly connected with a core push rod 702 through a connecting rod, and the lower end of the core push rod 702 extends to below the movable interface 74.

[0023] like Figure 7 The connection block 7 includes a fixed liquid guide plate 71 fixed and communicated with the upper ring body 61, a dynamic liquid guide plate 72 connected to the dynamic interface 74, and two bellows 73 respectively connected between the fixed liquid guide plate 71 and the dynamic liquid guide plate 72. The lower end of the dynamic liquid guide plate 72 is also fixedly connected to an elastic pad. The two dynamic interfaces 74 are fixedly penetrated through the elastic pad. When the dynamic interface 74 penetrates into the fixed interface 52, so that the circumferential cooling rack is connected to the cooling plate 5, the edge of the mouth of the fixed interface 52 can contact with the elastic pad, thereby improving the formation of a sealing layer outside the connection between the two, thereby In order to effectively improve the sealing performance, two independent water guide chambers are arranged inside the fixed liquid guide plate 71 and the dynamic liquid guide plate 72. The two bellows 73 are respectively connected to the two water guide chambers on the same side of the fixed liquid guide plate 71 and the dynamic liquid guide plate 72. Two electric push rods 701 are also installed between the outer ends of the fixed liquid guide plate 71 and the dynamic liquid guide plate 72. The electric push rod 701 is used to control the dynamic liquid guide plate 72 to approach or move away from the fixed interface 52, so as to realize the connection or disconnection between the circumferential cooling rack and the cooling plate 5. The solenoid valve and the electric push rod 701 are both connected to the control center signal.

[0024] The circumferential cooling rack includes an upper ring body 61 connected to the outside of the sand mixer body 1 and a plurality of evenly distributed lower extension pieces 62 fixedly connected to the lower end of the upper ring body 61. Both the upper ring body 61 and the lower extension pieces 62 are hollow structures, and a plurality of liquid guide plates 63 corresponding to the plurality of lower extension pieces 62 are fixedly connected to the top of the upper ring body 61. The liquid guide plates 63 extend into the lower extension pieces 62, and the bottom of the liquid guide plates 63 does not contact the bottom of the lower extension pieces 62. The upper ring body 61 and the lower extension pieces 62 are separated into continuous flow channels by the plurality of liquid guide plates 63. When the circumferential cooling rack is connected to the cooling plate 5, the coolant enters the upper ring body 61 along the selection block 7 and can then pass through the plurality of lower extension pieces 62 along the flow channel and flow back into the selection block 7, thereby forming a circulation, which is convenient for continuous cooling of the sand in the sand mixer body 1.

[0025] like Figure 6 A flat baffle 53 is fixedly connected inside the cooling plate 5, and the end of the flat baffle 53 extends into the L-shaped hollow block 51 and is fixedly connected to the inner wall of the L-shaped hollow block 51 on the side away from the cooling plate 5. The flat baffle 53 divides the L-shaped hollow block 51 and the inside of the cooling plate 5 into two cavities. The two cavities on the same side of the L-shaped hollow block 51 and the cooling plate 5 are connected, and the two fixed interfaces 52, the liquid inlet pipe 501 and the liquid discharge pipe 502 are respectively connected to the four cavities. An exchange hole 54 is drilled at one end of the flat baffle 53 away from the L-shaped hollow block 51, and an electromagnetic valve is installed at the exchange hole 54. When the exchange hole 54 is opened, the exchange hole 54 is opened ... During single-stage cooling, only the cooling disk 5 works. At this time, the solenoid valve at the exchange hole 54 is controlled to be open, so that the two sides of the exchange hole 54 are connected. When the coolant enters one of the cavities in the cooling disk 5 through the liquid inlet pipe 501, it can enter the other cavity along the exchange hole 54, and then be discharged through the liquid discharge pipe 502. When the coolant is continuously introduced, the coated sand in the sand mixer body 1 can be cooled through the bottom of the sand mixer body 1. In this process, part of the coolant will enter the L-shaped hollow block 51. Due to the effect of the one-way valve in the fixed interface 52, the coolant is difficult to overflow.

[0026] When the circumferential cooling rack is connected to the cooling plate 5 through the optional parts, the electromagnetic valve at the exchange hole 54 is synchronously controlled to be closed. At this time, the sand inside the sand mixer body 1 can be cooled in two stages at the bottom of the sand mixer body 1 and the periphery of the sand mixer body 1. At this time, since the movable interface 74 is embedded in the fixed interface 52, the core push rod 702 can contact the one-way valve in the fixed interface 52, so that the valve core is difficult to approach the mouth of the L-shaped hollow block 51 for one-way blocking when the coolant is squeezed. Figure 5 and Figure 7At this time, after the coolant enters the cooling plate 5 along the liquid inlet pipe 501, it will first enter a cavity in the adjacent L-shaped hollow block 51, and then enter the water guide cavity in the movable liquid guide plate 72, the bellows 73 and the water guide cavity in the fixed liquid guide plate 71 along the fixed interface 52 and the movable interface 74 connection in sequence, and finally enter the upper ring body 61, and the flow channel formed in the upper ring body 61 and the multiple lower extension pieces 62, and then flow back to the selection block 7, and pass through the other side in sequence. The coolant flows through the water guide cavity in the fixed liquid guide plate 71, the bellows 73, the water guide cavity in the dynamic liquid guide plate 72 and the L-shaped hollow block 51, and finally flows back into another cavity in the cooling disk 5, and then is discharged through the drain pipe 502, so that the coolant circulates in the cooling disk 5 and the circumferential cooling rack, realizing two-stage cooling, thereby greatly accelerating the cooling speed of the coated sand and shortening the overall preparation time. Compared with the existing natural cooling, for the preparation of large volumes of coated sand, the preparation efficiency is greatly accelerated.

[0027] In summary, by adding a disintegrating agent to the raw sand together with phenolic resin, a high-strength, low-gassing, and easily disintegratable coated sand can be obtained, which meets the needs of a water-cooled exhaust manifold. In addition, during the preparation process, by setting a two-stage cooling unit outside the sand mixer, in the early stage of the preparation of the coated sand, the coated sand inside the bottom of the sand mixer body 1 can be cooled in a single stage according to actual needs. In the later stage of the preparation, while waiting for cooling and discharging, the circumferential cooling rack can be controlled to access the cooling plate 5 through the setting of optional parts, so that the two are connected as a whole, and then the coated sand in the sand mixer body 1 is cooled in two stages together, thereby greatly expanding the heat exchange area between the two-stage cooling unit and the raw sand, thereby effectively accelerating the speed at which the coated sand drops to the target temperature, effectively shortening the discharging time, and greatly accelerating the production efficiency for large volumes of coated sand.

[0028] The second implementation method: Based on the first embodiment, this embodiment further improves the fixed interface 52, and the rest of the embodiment is consistent with the first embodiment.

[0029] Fig. 9 As shown, the fixed interface 52 includes an inner fixed layer 521 fixedly connected to the L-shaped hollow block 51, two outer jacket layers 522 sleeved outside the inner fixed layer 521, and a measuring sleeve 8 fixedly connected between the two outer jacket layers 522. The lower outer jacket layer 522 is fixedly connected to the L-shaped hollow block 51, and the upper outer jacket layer 522 is higher than the inner fixed layer 521. A water-proof pipe 9 is fixedly connected between the two measuring sleeves 8 outside the two fixed interfaces 52. A warning light is also installed on the L-shaped hollow block 51. Two wires are led out of the circuit where the warning light is located, and the two wires extend into the water-proof pipe 9 and do not touch each other.

[0030] like Figure 10-11In the figure, a represents a conductor. The measuring sleeve 8 includes a bottom plate 81, an air cushion layer 82 fixedly connected to the upper end of the bottom plate 81, and a water cushion 83 fixedly attached to the upper surface of the bottom plate 81. The outer diameters of the bottom plate 81 and the air cushion layer 82 are larger than the outer diameter of the outer jacket layer 522. The water cushion 83 is located on the inner side of the air cushion layer 82. The outer end of the water cushion 83 is fixedly connected with a liquid guide tube 801. The liquid guide tube 801 is fixedly penetrated through the air cushion layer 82 and communicated with the waterproof tube 9. It includes two liquid storage sections 91 and a restraining section 92 fixedly connected between the two liquid storage sections 91. Two tightly attached elastic waterproof layers 93 are fixedly connected in the restraining section 92. The ends of the two conductors extend from both sides into the two elastic waterproof layers 93 and are fixedly attached to the inner walls of the elastic waterproof layers 93.

[0031] When the movable interface 74 is inserted into the fixed interface 52, the elastic pad under the movable liquid guide plate 72 will first contact the outer layer 522 and push the outer layer 522 downward until the upper end of the outer layer 522 is flush with the inner fixed layer 521. At this time, the measuring sleeve 8 is squeezed, and the lower end of the outer layer 522 gradually approaches the water cushion 83 through the upper surface of the air cushion layer 82, and the water cushion 83 is squeezed. Fig.12 , so that the electrolyte water in the water pad 83 moves along the liquid guiding tube 801 into the water-avoiding tube 9, thereby causing the elastic water-avoiding layer 93 to be stretched. At this time, the electrolyte water liquid levels in the water pads 83 on the two fixed interfaces 52 are interconnected, and a conductive medium is generated between the ends of the two wires, thereby causing the circuit to be turned on, thereby lighting up the warning light. Based on this, it can indicate to the staff that the connection between the movable interface 74 and the fixed interface 52 is in place, thereby effectively avoiding the situation where the connection between the cooling disk 5 and the circumferential cooling rack is not in place, resulting in poor connection stability and causing coolant overflow, thereby effectively ensuring the stability of the entire secondary cooling process, and ensuring the effect of accelerating the efficiency of coated sand preparation.

[0032] In view of current practical needs, the above-mentioned implementation mode adopted in this application is not limited to the scope of protection. Various changes made within the knowledge scope of technical personnel in this field without departing from the concept of this application still fall within the scope of protection of the present invention.

Claims

1. A special coated sand for water-cooled exhaust manifold, characterized by: The invention comprises the following ingredients in parts by weight: 100% of raw sand, 1.2-1.8% of phenolic resin, 5% of calcium stearate by resin, 12-15% of hexamethylenetetramine by resin, and 0.5-1% of disintegrating agent by resin; The method for preparing coated sand for water-cooled exhaust manifold according to the above ingredients comprises the following steps: S1. Put the quantitative raw sand heated to 125-130℃ into the sand mixer for uniform mixing; The sand mixer comprises a sand mixer body (1) with a control center, the middle of the sand mixer body (1) is rotatably connected to a rotating shaft (2) via an electric turntable, the outer end of the rotating shaft (2) is equipped with a rolling hammer (3) and a stirring blade (4), the bottom of the sand mixer body (1) is fixedly connected to a cooling plate (5), the outer cover of the sand mixer body (1) is provided with a circumferential cooling frame, an optional part is provided between the circumferential cooling frame and the cooling plate (5), and the lower end of the cooling plate (5) is fixedly connected to a liquid inlet pipe (501) and a liquid discharge pipe (502); S2, then add quantitative phenolic resin and disintegrating agent and mix and grind for 40-50 seconds; S3, at this time, start the cooling plate (5) at the bottom of the sand mixer to perform bottom single-stage cooling on the raw sand, then add calcium stearate and mix and grind. When the raw sand is cooled to 100-110°C, add the urotropine aqueous solution and mix and grind for 10 seconds; S4. Add calcium stearate for a second time and mix and grind for 30-50 seconds. At this time, connect the circumferential cooling rack to the bottom cooling unit through the optional parts, so that the two are linked, and the coolant is filled in a synchronous cycle to perform double-stage cooling on the raw sand. When the temperature drops below 80°C, the finished product is discharged from the sand mixer and crushed and screened to obtain coated sand.

2. The coated sand for water-cooled exhaust manifold according to claim 1, characterized in that: The particle size of the raw sand is 40-70 meshes, and the disintegrating agent is calcium peroxide.

3. The coated sand for water-cooled exhaust manifold according to claim 1, characterized in that: The circumferential cooling rack comprises an upper ring body (61) connected to the outside of the sand mixer body (1) and a plurality of evenly distributed lower extension pieces (62) fixedly connected to the lower end of the upper ring body (61); the upper ring body (61) and the lower extension pieces (62) are both hollow structures, and a plurality of liquid guide plates (63) corresponding to the plurality of lower extension pieces (62) are fixedly connected to the top end of the upper ring body (61); the liquid guide plates (63) extend into the lower extension pieces (62), and the bottom of the liquid guide plates (63) does not contact the bottom of the lower extension pieces (62).

4. The coated sand for water-cooled exhaust manifold according to claim 1, characterized in that: The optional connection member comprises an optional connection block (7) fixed to and in communication with the lower end of the upper ring body (61) and an L-shaped hollow block (51) fixedly connected to the outer end of the cooling plate (5); the L-shaped hollow block (51) is located directly below the optional connection block (7); the upper end of the L-shaped hollow block (51) is fixedly connected to two fixed interfaces (52); one-way valves are installed in the two fixed interfaces (52); the lower end of the optional connection block (7) is fixedly connected to two movable interfaces (74) respectively matching the two fixed interfaces (52); a core push rod (702) is fixedly connected to the inside of the movable interface (74) via a connecting rod; the lower end of the core push rod (702) extends to below the movable interface (74).

5. The coated sand for water-cooled exhaust manifold according to claim 1, characterized in that: A flat baffle (53) is fixedly connected inside the cooling plate (5), and an end of the flat baffle (53) extends into the L-shaped hollow block (51) and is fixedly connected to the inner wall of the L-shaped hollow block (51) away from the cooling plate (5). The flat baffle (53) divides the L-shaped hollow block (51) and the inside of the cooling plate (5) into two cavities. The two cavities on the same side of the L-shaped hollow block (51) and the cooling plate (5) are connected, and the two fixed interfaces (52), the liquid inlet pipe (501) and the liquid discharge pipe (502) are respectively connected to the four cavities. An exchange hole (54) is drilled at one end of the flat baffle (53) away from the L-shaped hollow block (51), and a solenoid valve is installed at the exchange hole (54).

6. The coated sand for water-cooled exhaust manifold according to claim 4, characterized in that: The selection block (7) comprises a fixed liquid guide plate (71) fixed to and in communication with the upper ring body (61), a dynamic liquid guide plate (72) connected to a dynamic interface (74), and two bellows (73) respectively connected between the fixed liquid guide plate (71) and the dynamic liquid guide plate (72); an elastic pad is also fixedly connected to the lower end of the dynamic liquid guide plate (72); the two dynamic interfaces (74) are fixedly penetrated through the elastic pad; two independent water guide cavities are arranged inside the fixed liquid guide plate (71) and the dynamic liquid guide plate (72); the two bellows (73) are respectively connected to the two water guide cavities on the same side of the fixed liquid guide plate (71) and the dynamic liquid guide plate (72); two electric push rods (701) are also installed between the outer ends of the fixed liquid guide plate (71) and the dynamic liquid guide plate (72); the solenoid valve and the electric push rod (701) are both connected to the control center signal.

7. The coated sand for water-cooled exhaust manifold according to claim 5, characterized in that: The fixed interface (52) comprises an inner fixed layer (521) fixedly connected to the L-shaped hollow block (51), two outer layers (522) sleeved outside the inner fixed layer (521), and a connecting sleeve (8) fixedly connected between the two outer layers (522), the lower outer layer (522) being fixedly connected to the L-shaped hollow block (51), and the upper outer layer (522) being higher than the inner fixed layer (521), a water-proof pipe (9) being fixedly connected between the two connecting sleeves (8) outside the two fixed interfaces (52), and a warning light being further installed on the L-shaped hollow block (51), two wires being led out of a circuit where the warning light is located, and the two wires both extending into the water-proof pipe (9) and not contacting each other.

8. The coated sand for water-cooled exhaust manifold according to claim 7, characterized in that: The measuring sleeve (8) comprises a bottom plate (81), an air cushion layer (82) fixedly connected to the upper end of the bottom plate (81), and a water cushion (83) fixedly attached to the upper surface of the bottom plate (81); the water cushion (83) is located inside the air cushion layer (82); the outer end of the water cushion (83) is fixedly connected to a liquid guide tube (801); the liquid guide tube (801) is fixedly passed through the air cushion layer (82) and communicated with the water-proof tube (9).

9. The coated sand for water-cooled exhaust manifold according to claim 8, characterized in that: The water-proof tube (9) comprises two liquid storage sections (91) and a binding section (92) fixedly connected between the two liquid storage sections (91); two tightly attached elastic water-proof layers (93) are fixedly connected inside the binding section (92); the ends of the two wires extend from both sides into the two elastic water-proof layers (93) and are fixedly attached to the inner walls of the elastic water-proof layers (93).

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