An automatic molding line die for clay sand and a casting method

Abstract

The present invention discloses a mold for a clay sand automatic molding line and a casting method, including an upper mold, a lower mold and a gating system. The forming outer mold (1) and the mold plate (2) are made separately. A sunken platform (3) is arranged on the upper part of the mold plate (2), and a boss matching with the sunken platform (3) is arranged at the bottom of the forming outer mold (1). The forming outer mold (1) is made of PVC hard board. An exhaust branch channel (10) is arranged on the opposite surface of each ingate (8) in the forming outer mold (1) on the upper mold, and the exhaust branch channel (10) is communicated to the exhaust port (9) through an exhaust channel (11) arranged on the periphery of the forming outer mold (1). In the mold for the clay sand automatic molding line of the present invention, the forming outer mold is made of PVC hard board, which not only ensures the surface roughness of the forming outer mold, but also greatly reduces the production cost and lightens the weight of the overall mold. A runner is arranged in the middle of the product forming outer mold, and exhaust channels on both sides are communicated with the exhaust port, ensuring the quality of the casting.

Description

Technical Field

[0001] The present invention relates to the technical field of casting molds, and specifically to a mold for a clay sand automatic molding line and a casting method. Background Art

[0002] During casting, molding sands are used in molding. According to different binders used, molding sands can be divided into clay sands, sodium silicate sands, cement sands, resin sands, etc. By using an automatic production line of clay sands, 40 - 60 molds can be made per hour, greatly improving the production efficiency. Moreover, the products can meet the usage requirements, saving costs while increasing production efficiency. Clay sands need to use molds in the actual molding process. Traditional molds for automatic production lines of clay sands are generally metal molds, with materials being aluminum alloy or ordinary carbon steel. The production cost of the molds is high. When replacing the molds on an automatic molding machine, a crane is required. Due to the limitation of the operation space, the efficiency of replacing the molds is very low. With the rapid development of the numerical control industry, the demand for multi-variety and small-batch parts is increasingly becoming a trend. For enterprises producing ordinary sand-cast parts, the investment in developing casting molds will increase significantly.

[0003] Traditional wooden molds for casting are suitable for casting parts with small production batches, large volumes, and those that are not suitable for making metal molds. Wooden molds have the advantages of low production cost and short production cycle. Due to the texture structure on the surface of wood, during the actual use of the mold, it is relatively easy to adhere sand, which leads to problems such as poor mold demoulding property and damage to the mold surface, thus affecting the surface quality of the sand core. Currently, the general method is to apply a demoulding agent on the surface of the wooden mold, and it needs to be applied once every time the mold is used. Due to the long-term use of the demoulding agent, the accumulation of the demoulding agent coating results in poor mold accuracy. Moreover, the manual operation time is long, the operation is relatively cumbersome, and when the sand box is placed on the wooden template during the use of the wooden template, the wooden template directly contacts the sand box. Due to the heavy weight of the sand box, it will exert a large pressure on the template, causing wear, deformation, and damage to the template. Summary of the Invention

[0004] To adapt to the production environment with a large variety of small parts, many types of molds, and frequent replacements, the present invention provides a mold for a clay sand automatic molding line and a casting method. By using PVC hard boards to make the pattern and separately forming the pattern and the template, this mold can solve the problem of sand adhesion of wooden molds while meeting the requirements of use performance, and can also greatly save the cost of manufacturing metal molds.

[0005] To achieve the above object, the present invention provides the following technical solution: A mold for a clay sand automatic molding line includes an upper mold, a lower mold, and a pouring system. A number of groups of outer molds 1 for product forming are correspondingly distributed on the upper mold and the lower mold. Each group of outer molds 1 for product forming is installed at the corresponding template 2 on the upper mold and the lower mold. After the upper mold and the lower mold are combined, a casting cavity is formed.

[0006] The forming outer mold 1 and the template 2 are made separately. To reduce the weight of the mold, the templates 2 of the upper and lower molds are made of wood. A sunken platform 3 is provided at the upper part of the template 2, and a boss matching the sunken platform 3 is provided at the bottom of the forming outer mold 1. After processing, the sunken platform 3 and the boss are compounded for positioning and assembly, and screws are nailed. That is, by using the sunken platform 3 on the template 2, it is ensured that the forming outer mold 1 will not be misaligned when installed on the template 2. Through grooves 4 are provided at the same position on the back of the templates 2 of the upper and lower molds, and square steel bars 5 with a size of 20*40mm matching them are installed in the through grooves 4. The length of the square steel bars 5 is the same as the length of the template 2 to ensure the consistency of the upper and lower molds and the strength of the template 2.

[0007] The pouring system includes a sprue 6, a runner 7 and internal gates 8 at all levels. A pouring port is provided at the center of the forming outer mold 1 of the upper mold, and exhaust ports 9 are provided at both ends. The bottom of the sprue 6 corresponding to the pouring port is connected to the input end of the runner 7. The internal gates 8 are provided between the runner 7 and the parts on both sides of it. The internal gates 8 are located in the upper mold to connect the forming outer molds 1 of the product to the runner 7.

[0008] To reduce costs while ensuring the surface roughness of the mold, the forming outer mold 1 is made of PVC hard board. This not only ensures the surface roughness of the forming outer mold 1, but also greatly reduces the manufacturing cost of the forming outer mold 1 and reduces the overall weight of the mold. When replacing the mold, the mold can be replaced by just two people lifting it by hand. However, threads cannot be tapped on the PVC hard board, so exhaust pins cannot be installed. To solve this problem and adapt to the pouring of different parts, an exhaust branch 10 is provided on the opposite side of the internal gate 8 of each forming outer mold 1 on the upper mold. The exhaust branch 10 is connected to the exhaust port 9 through an exhaust channel 11 provided on the periphery of the forming outer mold 1, thus realizing exhaust without exhaust pins for the mold, reducing the use of exhaust pins and lowering the cost.

[0009] The cross-section of the internal gate 8 is triangular, sloping downward from the runner 7 to the parts on both sides of it.

[0010] To prevent molten iron from leaking out of the mold, concave-convex plates are provided at the junction of the forming outer mold 1 of the lower mold and the template 2.

[0011] A casting method for a mold of a clay sand automatic molding line includes the following steps:

[0012] A. Layout the mold: Adopt the plane parting process, arrange the mold cavities with multiple molds in one pattern according to the outer shape and internal cavity size of the product, and design the pouring system;

[0013] B. Mold manufacturing: Use wood boards to make the template. A sunken platform is machined on the front of the template, and through slots are provided at the same position on the back of the templates of the upper model and the lower model; Use a CNC machining center to process PVC hard boards to make the forming outer molds of the upper model and the lower model respectively. A convex platform is provided at the bottom of the forming outer mold. After processing, the sunken platform and the convex platform are used for positioning and assembly in a composite manner, and screws are nailed. The forming outer mold is positioned on the template;

[0014] C. Mold clamping: Install 20*40mm square steel bars in the through slots on the templates of the upper model and the lower model to clamp the upper and lower models;

[0015] D. Flask closing and pouring: Close the upper flask and the lower flask together, press the mold in the middle, inject sand into the upper flask and the lower flask through the sand injection ports. The upper model is formed by the upper flask, and the lower model is formed by the lower flask. After forming, the upper and lower flasks are opened, the mold is withdrawn, and the upper flask and the lower flask are closed together again and retreated to the pouring line; After treating the ladle, add spheroidizing agent and inoculant, control the sand mold temperature ≤150°C, the pouring temperature is 1350 - 1420°C, and the pouring time for each flask is within 16 seconds; The gas generated in the cavity can be collected from the exhaust channels and discharged from the exhaust ports;

[0016] E. Flask opening: Loosen the flask clamps 20 minutes after pouring and open the flask 25 minutes after pouring. The temperature of the castings after flask opening ≤500°C;

[0017] F. Removing castings: After the casting flask is opened, place the castings on the tray by a manipulator, cut off the gating system, polish the surface of the product smooth and flat, and check the dimensions and surface quality of the product.

[0018] The beneficial effects of the present invention are as follows: ① The forming outer mold in the mold of the clay sand automatic molding line of the present invention is made of PVC hard board, which not only ensures the surface roughness of the forming outer mold, but also greatly reduces the production cost and lightens the overall weight of the mold. A sprue is provided in the middle of the product forming outer mold, and there are exhaust channels on both sides connected to the exhaust ports to ensure the quality of the castings.

[0019] ② The outer mold and the template are made separately. After processing, they are positioned and assembled in a composite manner using a sunken platform and a convex platform, and screws are nailed, so there will be no dislocation. The template and the model are independent of each other and can be disassembled and replaced at any time, avoiding the problem that the whole set of molds is scrapped due to the asynchronous service life of each component. An uneven board is provided at the junction of the forming outer mold of the lower model and the template, which can effectively prevent molten iron from leaking out of the flask.

[0020] ③ The templates of the upper model and the lower model are made of wood materials, and through slots are provided at the same position on the back. 20*40mm square steel bars are installed in the through slots, and the length is the same as the length of the template, which can ensure the consistency of the upper model and the lower model and increase the strength of the wooden template. Description of the Drawings

[0021] Figure 1 Schematic diagram of the three-dimensional structure of the upper model of the present invention.

[0022] Figure 2 Schematic diagram of the template structure of the present invention.

[0023] Figure 3 Schematic diagram of the upward view structure of the upper model of the present invention.

[0024] Figure 4 Schematic diagram of the structure of the lower model of the present invention.

[0025] Figure 5 Schematic diagram of the assembled structure of the upper model and the lower model of the present invention.

[0026] In the figure: the forming outer mold 1, the template 2, the sunken platform 3, the through groove 4, the square steel bar 5, the sprue 6, the cross sprue 7, the inner sprue 8, the exhaust port 9, the exhaust branch 10, the exhaust duct 11. Specific embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention.

[0028] Embodiment 1: Please refer to Figures 1-4 [[ID=**30**]], a clay sand automatic molding line mold. This embodiment is a tail seat mold, including an upper model, a lower model and a pouring system. A number of groups of product forming outer molds 1 are correspondingly distributed on the upper model and the lower model. Each group of product forming outer molds 1 is installed at the corresponding template 2 on the upper model and the lower model. After the upper model and the lower model are combined, a casting cavity is formed.

[0029] The forming outer mold 1 and the template 2 are made in a split manner. The template 2 is made of wood material, and a sunken platform 3 is provided on the upper part. The forming outer mold 1 is made of PVC hard board, and a boss matching with the sunken platform 3 is provided at the bottom. After processing, the sunken platform 3 and the boss are positioned and assembled in a composite manner, and screws are nailed. That is, by using the sunken platform 3 on the template, it is ensured that the forming outer mold 1 of the upper model is installed on the upper surface of the template 2, and the forming outer mold 1 of the lower model is installed on the lower surface of the template 2 without dislocation. An uneven board is provided at the junction of the forming outer mold 1 of the lower model and the template 2.

[0030] The pouring system includes a sprue 6, a cross-riser 7 and internal risers 8 at all levels. A pouring gate is provided at the central position of the forming outer mold 1 of the upper mold, and vent ports 9 are provided at both ends. The bottom of the sprue 6 corresponding to the pouring gate at the central position is connected to the input end of the cross-riser 7. The internal risers 8 are arranged between the cross-riser 7 and the parts on both sides thereof. The internal risers 8 are located in the upper mold, enabling communication between the forming outer molds 1 of the product and the cross-riser 7. The cross-section of the internal riser 8 is triangular, sloping downward from the cross-riser 7 to the parts on both sides thereof. An exhaust branch 10 is provided on the opposite side of the internal riser 8 in each forming outer mold 1, and the exhaust branch 10 is connected to the vent port 9 through an exhaust channel 11 provided on the periphery of the forming outer mold 1.

[0031] Embodiment 2: Please refer to Figures 1-4 , a mold for a clay sand automatic molding line. This embodiment is a tailstock mold, including an upper mold, a lower mold and a pouring system. A number of groups of product forming outer molds 1 are correspondingly distributed on the upper mold and the lower mold. Each group of product forming outer molds 1 is installed at the corresponding template 2 on the upper mold and the lower mold. After the upper mold and the lower mold are combined, a casting cavity is formed.

[0032] The forming outer mold 1 and the template 2 are made separately. The template 2 is made of wood material, with a sunk platform 3 provided on the upper part. The forming outer mold 1 is made of PVC hard board, with a boss provided at the bottom that matches the sunk platform 3. After processing, the sunk platform 3 and the boss are positioned and assembled in a composite manner, and screws are nailed. That is, by using the sunk platform 3 on the template, it is ensured that the forming outer mold 1 of the upper mold is installed on the upper surface of the template 2, and the forming outer mold 1 of the lower mold is installed on the lower surface of the template 2 without misalignment. An uneven board is provided at the junction of the forming outer mold 1 of the lower mold and the template 2.

[0033] The pouring system includes a sprue 6, a cross-riser 7 and internal risers 8 at all levels. A pouring gate is provided at the central position of the forming outer mold 1 of the upper mold, and vent ports 9 are provided at both ends. The bottom of the sprue 6 corresponding to the pouring gate at the central position is connected to the input end of the cross-riser 7. The internal risers 8 are arranged between the cross-riser 7 and the parts on both sides thereof. The internal risers 8 are located in the upper mold, enabling communication between the forming outer molds 1 of the product and the cross-riser 7. The cross-section of the internal riser 8 is triangular, sloping downward from the cross-riser 7 to the parts on both sides thereof. An exhaust branch 10 is provided on the opposite side of the internal riser 8 in each forming outer mold 1, and the exhaust branch 10 is connected to the vent port 9 through an exhaust channel 11 provided on the periphery of the forming outer mold 1.

[0034] A casting method for a mold of a clay sand automatic molding line includes the following steps:

[0035] A. Layout the mold: Adopt the plane parting process, arrange the mold cavities with multiple molds in one pattern according to the shape and internal cavity size of the product, and design the pouring system;

[0036] B. Mold manufacturing: Use wood boards to make the formboards. Process a sunk platform on the front of the formboard, and set through slots at the same position on the back of the formboards of the upper and lower models; Use a CNC machining center to process PVC hard boards to make the forming outer molds of the upper and lower models respectively. Set a convex platform at the bottom of the forming outer mold. After processing, position and assemble them in a compound manner of the sunk platform and the convex platform, nail on the screws, and position the forming outer mold on the formboard;

[0037] C. Mold clamping: Install 20*40mm square steel bars in the through slots on the formboards of the upper and lower models to clamp the upper and lower models;

[0038] D. Flask closing and pouring: Close the upper and lower flasks together, press the mold in the middle, inject sand into the upper and lower flasks through the sand injection ports. The upper model is formed by the upper flask, and the lower model is formed by the lower flask. After forming, open the upper and lower flasks, withdraw the mold, and then close the upper and lower flasks together and move them to the pouring line; After treating the ladle, add spheroidizing agent and inoculant, control the sand mold temperature ≤ 150°C, the pouring temperature is 1350 - 1420°C, and the pouring time for each flask is within 16 seconds; The gas generated in the cavity can be collected from the exhaust channels and discharged from the exhaust ports;

[0039] E. Flask opening: Loosen the flask clamps 20 minutes after pouring and open the flask 25 minutes after pouring. The temperature of the castings after flask opening ≤ 500°C;

[0040] F. Casting removal: After the casting is removed from the flask, place it on the tray by the manipulator, cut off the gating and risering system, polish the surface of the product smooth and flat, and check the dimensions and surface quality of the product.

Claims

1. A clay sand automatic molding line mold, comprising an upper mold, a lower mold and a pouring system, wherein a plurality of groups of product molding outer molds (1) are correspondingly distributed on the upper mold and the lower mold, and each group of product molding outer molds (1) is installed at the corresponding mold plates (2) on the upper mold and the lower mold, and the upper mold and the lower mold are combined to form a casting cavity, characterized in that: The outer mold (1) and the mold plate (2) are made of separate parts. The mold plate (2) is made of wood. A sink (3) is provided on the upper part of the mold plate (2). A boss matched with the sink (3) is provided on the bottom of the outer mold (1). A through groove (4) is provided at the same position on the back of the mold plates (2) of the upper model and the lower model. A 20*40 mm square steel bar (5) matching with the square steel bar (5) is installed in the through groove (4). The length of the square steel bar (5) is consistent with the length of the mold plate (2). The pouring system includes a sprue (6), a runner (7) and various levels of ingrowns (8). A gate is provided at the center of the outer mold (1) of the upper model, and exhaust ports (9) are provided at both ends. The bottom of the sprue (6) corresponding to the gate is connected to the input end of the runner (7). The ingrowns (8) are provided between the runner (7) and the parts located on both sides thereof. The ingrowns (8) are located in the upper model so that the outer mold (1) of the product is connected to the runner (7). The molding outer mold (1) is made of PVC hard board, and an exhaust branch (10) is provided on the opposite side of the runner (8) of each molding outer mold (1) on the upper model, and the exhaust branch (10) is connected to the exhaust port (9) through an exhaust channel (11) provided on the periphery of the molding outer mold (1).

2. The clay sand automatic molding line mold according to claim 1, characterized in that: The cross section of the ingrown runner (8) is triangular, and it slopes downward from the runner (7) to the parts located on both sides thereof.

3. A clay sand automatic molding line mold according to claim 1 or 2, characterized in that: A concave-convex plate is provided at the junction of the lower model forming outer mold (1) and the mold plate (2).

4. A method for casting a clay sand automatic molding line mold according to any one of claims 1 to 3, characterized in that: The following steps are involved: A. Mold layout: Using the plane parting process, arrange the mold cavity of multiple molds according to the product's shape and inner cavity size, and design the pouring system; B. Mold Manufacturing: Wood is used to make the template. A sink is machined on the front of the template. A through slot is set at the same position on the back of the template for the upper and lower models. PVC hardboard is processed on a CNC machining center to make the upper and lower molds respectively. A boss is set at the bottom of the mold. After processing, the sink and boss are combined to position and assemble, and screws are screwed in to position the mold on the template. C. Mold closing: Install 20*40mm square steel bars in the through grooves on the upper and lower mold plates to close the upper and lower molds; D. Combining the flasks and pouring: close the upper and lower flasks together, press the mold in the middle, and shoot sand inwards from the upper and lower flasks. The upper model is formed by the upper flask, and the lower model is formed by the lower flask. After the molding is completed, the upper and lower flasks are opened, the mold is withdrawn, and the upper and lower flasks are combined together again and returned to the pouring line; after treating the ladle, add the spheroidizing agent and inoculant, control the sand mold temperature to ≤150℃, the pouring temperature to 1350-1420℃, and the pouring time for each flask is within 16 seconds; the gas generated in the cavity is collected from the exhaust duct and discharged from the exhaust port; E. Unpacking: loosen the box card 20 minutes after pouring is completed, and unpack the box 25 minutes later. The temperature of the unpacked castings should be ≤500℃; F. Casting: After unpacking, the casting is placed on a pallet by a robot, the pouring system is removed, the surface of the product is polished smooth and flat, and the size and surface quality of the product are checked.

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