Fusion welding type casting sand isolation chilling block
By using a sand barrier layer composed of high refractory and high thermal conductivity on the cold iron body, and forming a welded connection structure through high-temperature melt-infiltration, the existing sand barrier cold iron bonding strength and poor cooling effect are solved, and higher bonding strength and better cooling effect are achieved, and the quality of casting products is improved.
Patent Information
- Application Number
- CN202422156131.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-03
- Publication Date
- 2025-06-20
- Estimated Expiration
- 2034-09-03
AI Technical Summary
The existing sand-separating layer with sand-separating cold iron has poor thermal stability at high temperature, low bonding strength, easy to stick to castings, affect surface quality, and easy to fall off to cause sand-separating defects. Increasing the thickness of the sand-separating layer will hinder heat transfer and reduce the cooling effect.
A special sand with high refractory and high thermal conductivity is used to form a sand barrier layer, and a high temperature melting of the cold iron body is immersed into the gap between the sand barrier layer and the cold iron body to form a welded connection structure, which improves the bonding strength between the sand barrier layer and the cold iron body.
The bonding strength between the sand barrier layer and the cold iron body is significantly improved, the sand barrier layer falls off and sand grinding defects are avoided, the cooling effect is ensured, the casting production process is optimized, and the quality of casting products is improved.
Smart Images
Figure CN222999645U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of chill for casting, and particularly relates to a sand-separating chill for fusion welding casting. Background Art
[0002] Chills are one of the effective means for surface chilling and heat balance of castings in casting production. Especially during the casting process of castings with a large tendency of shrinkage porosity, such as ductile iron or steel castings, they usually need to be used in cooperation with the gating system and riser system to improve the filling and cooling process of the casting and reduce the tendency of shrinkage porosity. Chills are divided into external chills and internal chills according to their positional relationship with the pattern during use. Among them, external chills refer to the chills placed on the surface of the pattern during molding. Commonly used external chills are further divided into direct external chills and indirect external chills in terms of usage form. Since in casting production, in parts of the casting with large hot spots or where there is a lot of heat accumulation near the ingate, etc., the external chills are easily adhered to the casting due to temperature influence. This adhesion state is not only difficult to clean and separate, but also affects the quality of the casting after separation. Therefore, indirect external chills, usually sand-separating chills, must be used in these parts. The so-called sand-separating chill is to hang a separating sand layer on the working surface of the chill body to separate the working surface of the chill body from the high-temperature molten metal. In the prior art, usually, a Great Wall groove structure is first opened on the working surface of the chill body, and then the molding sand is adhesively covered on the working surface of the chill at room temperature. However, since the sand-separating layer of the sand-separating chill usually uses the same type of molding sand as the production mold, the high-temperature thermal stability is generally poor, and the adhesive strength at room temperature is low. During production, there is not only an obvious adhesion tendency and sand sticking risk with the casting, affecting the surface quality of the casting, but also it is extremely easy to cause shedding due to metal liquid erosion and scouring, resulting in sand inclusion defects in the casting. At the same time, increasing the thickness of the sand-separating layer to ensure the adhesive strength instead hinders the heat transfer speed and reduces the chilling effect of the chill. Therefore, it is necessary to improve and perfect the structural performance of the chill for casting, improve the bonding strength of the sand-separating layer of the chill, ensure the chilling effect, and improve the quality of the casting product. Summary of the Utility Model
[0003] The purpose of the utility model is to provide a sand-separating chill for fusion welding casting. By means of the high-temperature fusion welding method of the sand with high refractoriness and high thermal conductivity and the chill body, the bonding strength between the sand-separating layer and the chill body is improved, the chilling effect is ensured, and the problems of the prior art are solved.
[0004] A sand-separating chill for fusion welding casting, comprising: a chill body and a sand-separating layer covering the working surface of the chill body. The chill body is a metal casting formed body, and the sand-separating layer is composed of special sand with high refractoriness, high thermal conductivity, and good wettability for sand separation. The sand for forming the sand-separating layer is regularly laminated in different sub-layers with the working surface of the chill body as the base surface. By the way that the high-temperature molten state of the chill body infiltrates into the gaps between the sand, a fusion welding connection structure is formed with the chill body, so that there is a high bonding strength between the sand-separating layer and the chill body. Moreover, the high refractoriness and high thermal conductivity of the sand determine that the sand-separating layer also maintains good thermal conductivity, which can fully meet the requirements of the casting production process and ensure the production quality of the casting product; wherein: the sand for forming the sand-separating layer is preferably one of ceramsite sand, magnesite sand, and diamond sintered ceramic sand.
[0005] For the above-mentioned sand-separating chill for fusion welding casting, preferably, the distribution layer of the sand in the sand-separating layer has a decreasing particle size change gradient from the inside to the outside, that is: the particle size of the sand on the inner sand distribution layer is larger than the particle size of the sand on the surface sand distribution layer; because the particle size of the sand on the surface sand distribution layer is smaller and the gaps between the sand grains in the layer are relatively dense, it can better separate the casting liquid of the casting product during the casting production application, avoiding the contact between the casting liquid and the metal structure in the sand-separating layer and ensuring the quality of the casting product. And the particle size of the sand on the inner sand distribution layer is larger and the gaps between the sand grains in the layer are relatively loose, which is conducive to the full flow and infiltration of the molten metal into the arrangement gaps of the sand grains. After cooling, a multi-dimensional fusion welding hook connection structure can be formed, improving the firmness and reliability of the combination with the chill body.
[0006] For the above-mentioned sand-separating chill for fusion welding casting, preferably, a wedge-shaped inlay block is provided on the chill body. The wedge-shaped inlay block is arranged on the bare surface of the chill body for inlaying and matching with the casting sand of the sand-separating chill for fusion welding casting, ensuring the firmness and accuracy of the combined connection with the casting sand mold.
[0007] A manufacturing method of a sand-separating chill for fusion welding casting, comprising the following steps:
[0008] Step 1. According to the structural characteristics of the casting product and the casting process requirements, a fusion-bonded sand-insulating chiller is designed to match the design, and the setting position of the sand-insulating layer molding surface on the fusion-bonded sand-insulating chiller and the setting thickness of the sand-insulating layer 2 on the molding surface are determined. The sand constituting the sand-insulating layer is selected from special sands with high refractoriness, high thermal conductivity and good wettability, preferably one of gem sand, magnesia sand and diamond sintered ceramic sand. The surface sand-insulating layer in the sand-insulating layer is selected from the sand-insulating layer with the same particle size in the range of 60 to 80 meshes that matches the particle size of the molding sand of the casting mold for the casting product, and the internal sand-insulating layer is selected from the sand-insulating layer with the same particle size in the range of 20 to 40 meshes. The interlayer adhesive used for the layered configuration of the sand-insulating layer is selected from a liquid resin adhesive with good stability at room temperature and a pyrolysis temperature lower than the casting temperature of the fusion-bonded sand-insulating chiller, preferably a Bonnie resin adhesive.
[0009] Step 2. Make the fusion-bonded sand-insulating chilled iron casting model, pre-mark the marking line of the thickness of the sand-insulating layer on the casting model, and arrange the inner gate away from the forming surface of the sand-insulating layer to reduce the impact strength of the casting liquid on the forming surface of the sand-insulating layer and ensure the configuration quality of the sand-insulating layer.
[0010] Step 3. Using the casting model of the fusion-bonded sand-insulated chilled iron produced in step 2, a sand mold is prepared for use in the casting sand mold of the fusion-bonded sand-insulated chilled iron.
[0011] Step 4. Apply paint to the entire inner surface of the casting sand mold prepared in step 3 to prevent the molding sand on the casting sand mold from peeling off and sticking to the chiller body and the sand isolation layer during the casting process of the fusion-bonded sand isolation chiller in the subsequent steps, thereby affecting the production quality of the fusion-bonded sand isolation chiller.
[0012] Step 5. Horizontally place the cast sand mold with the mold opening facing upwards after being processed in Step 4. Evenly brush a layer of the selected interlayer binder in Step 1 on the forming surface of the sand separation layer in the cast sand mold. Immediately, fill the cast sand mold with the sand separation material having a particle size selected in the range of 60 - 80 mesh in Step 1 in a sprinkling manner, so that the sand separation material buries all the forming surfaces on the arranged surfaces of each sand separation layer. Keep it static for 1 minute. After the interlayer binder is initially cured, turn the cast sand mold 180° to be horizontally placed with the mold opening facing downwards, so that the sand separation material filled in the cast sand mold naturally falls and discharges. The sand separation material adhered to each forming surface by the interlayer binder constitutes the surface sand separation distribution layer in the sand separation layer. After it is determined that all the free sand separation material not adhered to the forming surface in the cast sand mold has been discharged, turn the cast sand mold 180° back to be horizontally placed with the mold opening facing upwards, and bake the surface sand separation distribution layer adhered to the forming surface at a temperature of 220°C to fully cure the interlayer binder, thus completing the configuration layout of the surface sand separation distribution layer.
[0013] Step 6. Continuously and evenly brush a layer of the interlayer binder on the surface sand separation distribution layer whose configuration layout is completed in Step 5. Immediately, fill the cast sand mold with the sand separation material having a particle size selected in the range of 20 - 40 mesh in Step 1 in a sprinkling manner, so that the sand separation material buries all the surface sand separation distribution layers on the arranged surfaces of each sand separation layer. Keep it static for 1 minute. After the interlayer binder is initially cured, turn the cast sand mold 180° to be horizontally placed with the mold opening facing downwards, so that the sand separation material filled in the cast sand mold naturally falls and discharges. The sand separation material adhered to the surface sand separation distribution layer by the interlayer binder constitutes the internal sand separation distribution layer in the sand separation layer. After it is determined that all the free sand separation material not adhered to the surface sand separation distribution layer in the cast sand mold has been discharged, turn the cast sand mold 180° back to be horizontally placed with the mold opening facing upwards, and bake the internal sand separation distribution layer adhered to the surface sand separation distribution layer at a temperature of 220°C to fully cure the interlayer binder, thus completing the configuration layout of one layer of the internal sand separation distribution layer; thereafter, repeat the above operation process, and successively stack and configure new internal sand separation distribution layers on the completed internal sand separation distribution layer until the overall set thickness of the layered structure of the sand separation layer marked by the thickness marking line is reached, thus completing the configuration layout of the sand separation layer.
[0014] Step 7. Perform molding casting on the welded sand-isolating chill casting mold with the sand-isolating layer configuration arranged in Step 6. After casting, cool for 1 hour, then perform shakeout treatment and cut off the gating system respectively. Finally, remove the attachments on the surface of the casting by manual trimming, thus completing the production of the welded sand-isolating chill.
[0015] For the manufacturing method of the welded sand-isolating chill for casting, preferably after arranging the configuration of the surface sand-isolating distribution layer in Step 5, first arrange a transition sand-isolating distribution layer on the surface sand-separating and sand-distributing layer, and then successively arrange the internal sand-isolating distribution layer on the transition sand-isolating distribution layer. The purpose of adding the transition sand-isolating distribution layer is to better separate the casting liquid of the casting product from the welded metal structure in the sand-isolating layer in cooperation with the surface sand-separating and sand-distributing layer on the premise of ensuring the integrity of the welded connection structure of the welded sand-isolating chill and the reliability of the process implementation of the welded connection structure. The method for arranging the configuration of the transition sand-isolating distribution layer is as follows: Completely and evenly brush a layer of the interlayer binder on the surface sand-isolating distribution layer with the configuration arranged in Step 5, and then immediately fill the sand-isolating sand with a selected particle size in the range of 40 to 60 meshes into the casting mold in a sprinkling manner, so that the sand-isolating sand buries the surface sand-isolating distribution layer on all the arranged positions of the sand-isolating layers. Keep it static for 1 minute. After the interlayer binder is initially cured, turn the casting mold 180° until the mouth of the mold faces down and is placed flat. The sand-isolating sand filled in the casting mold naturally falls and discharges, and the sand-isolating sand adhered to the surface sand-isolating distribution layer by the interlayer binder constitutes the transition sand-isolating distribution in the sand-isolating layer. When it is determined that all the free sand-isolating sand not adhered to the surface sand-isolating distribution layer in the casting mold has been discharged, then turn the casting mold 180° back to the horizontal position with the mouth of the mold facing up, and bake the transition sand-isolating distribution layer adhered to the surface sand-isolating distribution layer at a temperature of 220°C to fully cure the interlayer binder, thus completing the arrangement of the configuration of the transition sand-isolating distribution layer. After that, arrange the internal sand-isolating distribution layer on the transition sand-isolating distribution layer with the configuration arranged according to the operation method in Step 6.
[0016] The beneficial effects of the present utility model are as follows: A sand-separating chill for fusion casting is provided, which is welded to special sand with high refractoriness and high thermal conductivity in the form of heat fusion of the chill body. A sand-separating layer that is embedded and combined with the solid chill body is attached to the working surface of the chill body, significantly improving the bonding strength between the sand-separating layer and the chill body, and preventing the occurrence of the separation of the sand-separating layer or sand during the casting of casting products and quality defects such as sand inclusion in the casting products caused thereby. At the same time, due to the increase in the bonding strength of the sand-separating layer, the minimum thickness of the sand-separating layer that can be firmly bonded and attached to the chill body is greatly reduced, and the minimum can even be reduced to 1 mm. In addition, since the special sand used for sand separation has high refractoriness, thermal conductivity, and wettability, the existence of this sand-separating layer has little impact on the heat conduction performance of the chill body, making the chilling and cooling effects of the fusion sand-separating chill basically the same as those of directly using an external chill. Applying it to casting production is beneficial to optimizing the casting production process and thus improving the quality of casting products. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a structural diagram of a bolster for a freight train.
[0018] Figure 2 It is a front view of the structure of a sand-separating chill for the configuration of the drain hole of a bolster for a freight train.
[0019] Figure 3 is Figure 2 A-A sectional view in
[0020] Figure 4 It is an auxiliary view of the structure of a sand-separating chill for the configuration of the drain hole of a bolster for a freight train.
[0021] Figure 5 It is a schematic diagram of the welded structure of the sand-separating layer and the chill body of a sand-separating chill for the configuration of the drain hole of a bolster for a freight train. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] The bolster is a key component of the running part of a railway freight car and is manufactured by casting, such as Figure 1As shown, a drain hole 4 is provided at the lower part of the bolster to drain the liquid in the inner cavity of the bolster. To ensure the structural strength of the bolster, the edges of the drain hole 4 are provided with a thickened curling structure, and the thickened area of the curling is interlaced with the central double rib structure to form a large heat node. In casting production, such a thick and large heat node area in a thin-walled casting is very likely to form internal shrinkage defects. Therefore, during the casting process of the bolster, a chiller needs to be provided in this area for heat balance to ensure the quality of the casting product. However, since this area not only has a large amount of heat accumulation, but also And it is still in the flow channel of the casting liquid, and ordinary chillers often stick to the cast bolsters, while the sand-insulating chillers in the prior art often cause the sand layer to fall off, and sometimes the fallen sand particles will cause structural defects such as sand holes in the bolsters, and sometimes the exposed parts of the fallen sand layer will be embedded in the casting products and difficult to clean; in order to solve the above problems, the applicant has carried out an application test of the fusion-bonded sand-insulating chiller in the production of freight train bolsters, and achieved very ideal technical effects. Now, taking the preparation method of the fusion-bonded sand-insulating chiller used in the casting production of freight train bolsters as an example, combined with Figures 2 to 5 , a sand-insulated chilled iron for fusion casting and a method for making the same are further specifically described in the present invention.
[0023] A method for manufacturing a sand-insulated chilled iron for a fusion-bonded freight train bolster water hole configuration, comprising the following steps:
[0024] Step 1. On the sand-insulating cold iron 10 for the water hole configuration under the bolster of the freight train, Figures 2 to 5 As shown, the bottom surface and the inner side elevation surface need to be welded with a sand isolation layer 2, the sand isolation layer 2 is determined to be composed of gemstone sand, and is composed of three configuration layers, namely, a surface sand isolation distribution layer 5, a transition sand isolation distribution layer 6 and an internal sand isolation distribution layer 7, which are stacked in sequence, with a total thickness of 5 mm. The surface sand isolation distribution layer 5, the transition sand isolation distribution layer 6 and the internal sand isolation distribution layer 7 are respectively made of gemstone sand of the same particle size of 70 mesh, 50 mesh and 30 mesh. Based on excellent thermal stability and disintegrability, the interlayer adhesive between each configuration layer of the sand isolation layer 2 is selected to use Bonnie resin adhesive.
[0025] Step 2. Make a casting model of sand-insulating cold iron for the downhole configuration of the freight train bolster, mark the thickness marking lines of the sand-insulating layer 2 on the bottom surface and the inner vertical surface on the casting model, and set the inner gate at the right end of the upper end surface of the casting model.
[0026] Step 3. Using the casting model prepared in step 2, a sand casting mold of the sand-insulated chilled iron for the downspout configuration of the freight train bolster is prepared by a sand mold making method.
[0027] Step 4. Apply paint on the entire inner surface of the casting sand mold prepared in step 3.
[0028] Step 5. Place the casting sand mold processed in step 4 horizontally, and evenly apply a layer of the Bonnie resin binder on the molding surface of all the sand isolation layers 2 in the casting sand mold, and then sprinkle and fill the casting sand mold with 70 mesh uniform particle size of the pearl sand, so that the pearl sand completely buries the inner vertical surface of the casting sand mold that needs to be welded with the sand isolation layer 2. After standing for 1 minute, turn the casting sand mold 180° until the casting sand mold is upside down, so that the pearl sand filled in the casting sand mold naturally falls down. The pearl sand adhered to the molding surface by the Bonnie resin adhesive constitutes the surface sand isolation distribution layer 5 in the sand isolation layer 2. When the free pearl sand in the casting sand mold is completely removed, the casting sand mold is turned over 180° to return to a horizontal state, and at the same time, it is placed in a constant temperature blast drying box at 220°C to bake the surface sand isolation distribution layer 5 adhered to the molding surface to fully cure the interlayer adhesive and complete the configuration layout of the surface sand isolation distribution layer 5.
[0029] Step 6. Keep the casting sand mold horizontal, and evenly apply a layer of the Bonnie resin binder on the surface sand isolation distribution layer 5 that has been configured in the casting sand mold. Then, sprinkle and fill the casting sand mold with 50 mesh uniform particle size of the gem sand, so that the gem sand completely buries the inner side surface of the casting sand mold that needs to be welded with the sand isolation layer 2. After standing for 1 minute, turn the casting sand mold 180° until the casting sand mold is inverted, so that the gem sand filled in the casting sand mold naturally falls and is discharged by the The pearl sand adhered to the surface sand isolation distribution layer 5 by the Bonnie resin adhesive constitutes the transition sand isolation distribution layer 6 in the sand isolation layer 2. When all the free pearl sand in the casting sand mold is removed, the casting sand mold is turned 180° to return to a horizontal state, and at the same time, it is placed in a constant temperature blast drying box at 220°C to bake the transition sand isolation distribution layer 6 adhered to the surface sand isolation distribution layer 5 to fully cure the interlayer adhesive and complete the configuration layout of the transition sand isolation distribution layer 6.
[0030] Step 7. Keep the casting sand mold horizontal and flat, and evenly apply a layer of the Bonnie resin binder on the transition sand isolation distribution layer 6 that has been configured in the casting sand mold. Then, sprinkle and fill the casting sand mold with the 30-mesh uniform particle size of the gem sand, so that the gem sand completely buries the inner vertical surface of the casting sand mold that needs to be welded to the sand isolation layer 2. After standing for 1 minute, turn the casting sand mold 180° until the casting sand mold is inverted, so that the gem sand filled in the casting sand mold naturally falls and is discharged, and the gem sand adhered to the transition sand isolation distribution layer 6 by the Bonnie resin binder constitutes the internal sand isolation distribution layer in the sand isolation layer 2. Layer 7, when all the free gem sand in the casting sand mold is removed clean, the casting sand mold is turned over 180° to return to a horizontal state, and at the same time, it is placed in a constant temperature blast drying box to bake the internal sand isolation distribution layer 7 adhered to the transition sand isolation distribution 6 at a temperature of 220°C to fully solidify the interlayer adhesive and complete the configuration layout of a layer of the internal sand isolation distribution layer 7; thereafter, the above operation process is repeated repeatedly, and the next layer of the internal sand isolation distribution layer 7 is successively stacked and configured on the internal sand isolation distribution layer 7 that has been configured, until the overall design thickness of the sand isolation layer 2 is reached, and the configuration layout of the sand isolation layer 2 is completed.
[0031] Step 8. Form and cast the fusion-bonded sand-insulating chilled iron 10 casting sand mold in which the sand-insulating layer 2 configuration is arranged in step 7. The casting temperature is 1580°C. After pouring, it is cooled for 1 hour, and then the sand is removed. The pouring system is cut off by thermal cutting method, and finally the surface attachments are manually removed to complete the production of the fusion-bonded sand-insulating chilled iron 10.
[0032] The sand-insulated chilled iron for the water hole configuration under the bolster of a freight train is manufactured by the method for manufacturing the sand-insulated chilled iron for the water hole configuration under the bolster of a freight train described in this embodiment, such as Figures 2 to 4 As shown, the cold iron body 1 is immersed in the gap between the sand isolation layers 2 in a high-temperature molten state, and forms a fusion structure with the sand isolation layer 2 in a solidified state, and the combination between them is firm and stable. At the same time, two wedge-shaped mosaic blocks 3 are arranged on the cold iron body 1; the sand isolation layer 2, as shown Figure 5As shown, it is composed of three different layered surfaces, namely, a surface sand isolation distribution layer 5, a transition sand isolation distribution layer 6 and an internal sand isolation distribution layer 7. The sand isolations and the layered surfaces are arranged regularly, and the internal sand isolation distribution layer 7, the transition sand isolation distribution layer 6 and the surface sand isolation distribution layer 5 respectively use the sand isolation specifications of 30 mesh, 50 mesh and 70 mesh from the inside to the outside, which can form a decreasing gradient of particle size from the inside to the outside, so that the gap flux between the sand isolations in the sand isolation layer 2 decreases synchronously and linearly from the inside to the outside. At the same time, the use of gem sand with good wettability as the sand isolation is beneficial to the casting liquid of the cold iron body 1 to flow into each layer of the sand isolation layer 2 and ensure that it flows smoothly from the inside to the outside in the sand isolation layer 2 to penetrate and fill the gaps between the sand isolations. Therefore, in the fusion-bonded sand isolation cold iron after casting, the sand isolation layer 2 has a continuous and uniform organizational structure, as shown in FIG. Figure 5 As shown, there is no obvious unbalanced structural distortion and the resulting unbalanced internal stress, the overall structure is continuous and stable, and the tendency of local cracking or peeling is extremely small, which can fully guarantee the casting quality of the freight train bolsters; at the same time, the Bonnie resin adhesive is used as the interlayer adhesive of the sand isolation layer 2 configuration, and the Bonnie resin adhesive has good stability at room temperature and can be fully pyrolyzed at about 1350°C. When the interlayer adhesive encounters a casting liquid with a temperature of up to 1580°C during the casting and molding process of the fusion-bonded sand isolation chiller 10, it can be quickly heated and vaporized and dispersed, so that the casting liquid can quickly penetrate into the retreat space filled with the Bonnie resin adhesive and replace the Bonnie resin adhesive as a whole, thereby ensuring that the integrated casting molding process of the fusion-bonded sand isolation chiller 10 has sufficient technical feasibility and can obtain the fusion-bonded sand isolation chiller 10 with stable and reliable performance, thereby achieving the purpose of the utility model.
Claims
1. A sand-insulated chiller for fusion casting, characterized in that: include: A cold iron body (1) and a sand isolation layer (2) covering the working surface of the cold iron body (1), wherein the cold iron body (1) is a metal casting molded body, and the sand isolation layer (2) is composed of special sand with high refractoriness, high thermal conductivity and good wettability. The sand isolation layer (2) is regularly stacked and arranged in different layers with the working surface of the cold iron body (1) as the base surface, and the cold iron body (1) is melted at high temperature and immersed in the gaps between the sand isolation layers to form a fusion connection structure with the cold iron body (1).
2. A sand-insulated chiller for fusion casting as claimed in claim 1, characterized in that: The isolation sand constituting the isolation sand layer (2) is made of one of gemstone sand, magnesia sand and diamond sintered ceramic sand.
3. A sand-insulated chiller for fusion casting as claimed in claim 1 or 2, characterized in that: The distribution layer of the isolation sand in the isolation sand layer (2) has a gradient of decreasing particle size from the inside to the outside, that is, the particle size of the isolation sand on the internal isolation sand distribution layer (7) is greater than the particle size of the isolation sand on the surface isolation sand distribution layer (5).
4. A sand-insulated chiller for fusion casting as claimed in claim 3, characterized in that: The sand isolation layer (2) is composed of three different layered layers, namely, a surface sand isolation distribution layer (5), a transition sand isolation distribution layer (6), and an internal sand isolation distribution layer (7), and the sand isolation layers and the layered layers are arranged regularly.
5. The sand-insulated chiller for fusion casting as claimed in claim 1, characterized in that: A wedge-shaped inlay block (3) is arranged on the cold iron body (1), and the wedge-shaped inlay block (3) is arranged on the bare surface of the cold iron body (1).