Valve casting sand mold casting mold

Abstract

The utility model discloses a valve casting sand casting mold which comprises a base, a lower mold is fixed on the upper surface of the base, an upper mold is arranged above the lower mold, cavities are formed in the opposite faces of the upper mold and the lower mold, a sand inlet is formed in the top of the upper mold, and a motor is installed at the left end of the upper base. The left side of the upper surface of the base is in bearing connection with a threaded rod, and a fixing rod is fixed to the right side of the upper surface of the base. According to the valve casting sand mold casting mold, after a valve casting is completely solidified and cooled, a motor drives a threaded rod to rotate reversely, meanwhile, a driving gear drives a rack meshed with the driving gear to move rightwards and drives an attaching block to extrude an ejection plate, the ejection plate is made to move upwards, the valve casting in a sand mold can be ejected out stably and rapidly, and therefore the valve casting can be stably and rapidly ejected out. And casting damage and deformation or sand mold damage caused by difficult demolding is avoided, and the yield and the production efficiency of the casting are greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of mold technology, specifically to a sand casting mold for valve castings. Background Technology

[0002] With the development of various industries, the demand for valve castings is constantly increasing, and higher requirements are being placed on their quality, precision, and performance. Sand casting is a traditional and widely used casting process that can adapt to the production of castings with various complex shapes. For components like valves, which have irregular shapes, internal flow channels, and multiple connection structures, sand casting can achieve molding through reasonable design of molds and sand box structures. However, a drawback is that the internal runners, sprues, and riser paths of sand casting molds for spherical valves are generally long, resulting in a large amount of raw material not being effectively utilized, making it difficult to achieve overall cost reduction. To effectively control the above-mentioned defects, the prior art (Chinese patent application number: 202321439129.3, authorized announcement date: 2024-01-26) discloses a sand casting mold for ball valve castings that reduces production costs. By merging two outer molds, the two top sand inlets simultaneously replace the traditional sand inlets and risers, and the sand inlets also replace the sprue. The forming groove formed between the inner groove of the outer mold and the mold body replaces the runner, thereby greatly reducing the raw materials filled in the sprue, risers and runner, and thus effectively controlling the total cost.

[0003] Existing technology combines two outer molds, with two top sand inlets replacing the traditional sand inlet and riser, thus effectively controlling the total cost. However, after the valve casting is formed, the lack of an ejection mechanism means that the casting can only be removed manually or by other non-professional methods, which increases labor costs. At the same time, it is difficult to ensure the uniformity and accuracy of force application when removing the casting manually, which can easily lead to uneven stress on the casting, resulting in defects such as deformation and cracking, and reducing the yield of the casting. Therefore, we propose that the sand casting mold for valve casting can effectively solve the above problems. Utility Model Content

[0004] The purpose of this utility model is to provide a sand casting mold for valve castings to solve the problems mentioned in the background art, which are that the lack of an ejection mechanism means that castings can only be removed manually or by other non-professional methods, resulting in increased labor costs. At the same time, when removing castings manually, it is difficult to ensure the uniformity and accuracy of the applied force, which can easily cause uneven stress on the castings, leading to defects such as deformation and cracking, and reducing the yield of castings.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a sand casting mold for valve castings, comprising a base, a lower mold fixed on the upper surface of the base, and an upper mold above the lower mold, with cavities formed on the opposite surfaces of the upper and lower molds, and a sand inlet at the top of the upper mold, and a motor installed on the left end of the upper base; further comprising: a threaded rod connected to a bearing on the left side of the upper surface of the base, and a fixing rod fixed on the right side of the upper surface of the base, with connecting blocks sleeved on the outer sides of both the fixing rod and the threaded rod, and a drive gear fixedly sleeved on the outer side of the lower end of the threaded rod, a rack inside the lower mold located below the cavity, with fitting blocks fixed to the top right side of the rack, and an ejector plate connected inside the lower mold located below the cavity.

[0006] Preferably, the top of the threaded rod is fixedly connected to the output end of the motor, the connecting block on the left side is threadedly connected to the movable tube, the connecting block on the right side is slidably connected to the fixed rod, and the outer side of the upper mold is fixedly connected to the two connecting blocks.

[0007] Preferably, the left end of the rack extends out of the outer surface of the lower mold, and the rack and the drive gear are meshed.

[0008] Preferably, the top of the bonding block and the bottom of the ejector plate are both inclined, and the bonding block is in contact with the inclined surface of the ejector plate. Both ejector plates are slidably disposed inside the lower mold, and a return spring is installed between the outer side of the two ejector plates and the inside of the lower mold.

[0009] Preferably, positioning rods are fixed at equal intervals at the four corners of the bottom of the upper mold, and positioning holes are opened at equal intervals around the top of the lower mold. The positions of the positioning rods and the positioning holes correspond one-to-one, and the positioning rods and the positioning holes are connected by an insertion.

[0010] Preferably, a movable tube is rotatably connected to the upper surface of the base between the threaded rod and the lower mold, and a driven gear is fixedly sleeved on the outer side of the lower end of the movable tube. Spray nozzles are installed at equal intervals on the outer side of the movable tube away from the driven gear, and a connecting hose is fixed to the end of the movable tube away from the driven gear.

[0011] Preferably, the movable tube is arranged in an inverted "L" shape, the driven gear and the driving gear are meshed, and the end of the connecting hose away from the movable tube is connected to an external air pump.

[0012] Compared with the prior art, the beneficial effects of this utility model are: the sand casting mold for valve casting adopts a novel structural design, the specific details of which are as follows:

[0013] (1) After the valve casting has completely solidified and cooled, the motor drives the threaded rod to rotate in the opposite direction. At the same time, the drive gear drives the meshing rack to move to the right and drives the contact block to squeeze the ejector plate, so that the ejector plate moves upward. This can smoothly and quickly eject the valve casting in the sand mold, avoiding casting damage, deformation or sand mold destruction caused by difficult demolding, and greatly improving the casting yield and production efficiency. Furthermore, when the motor drives the threaded rod to rotate in the forward direction, the rack moves to the right and drives the contact block to stop squeezing the ejector plate, so that the ejector plate is reset under the elastic force of the return spring, which is convenient for the next ejection.

[0014] (2) An external air pump is connected to the movable tube via a connecting hose. When the driving gear rotates, it drives the meshing driven gear to rotate, causing the movable tube to rotate between the upper and lower molds. Then, the air pump delivers gas into the movable tube through the connecting hose and blows air onto the formed valve casting through multiple nozzles on the movable tube to cool it down. This can accelerate the cooling speed of the casting, shorten its cooling time, and thus shorten the entire production cycle and improve production efficiency.

[0015] (3) The motor drives the threaded rod to rotate in the forward direction, causing the upper mold to move downward and close with the lower mold. The positioning rod is inserted into the positioning hole, thus ensuring that the upper mold and the lower mold are accurately aligned during the mold closing process. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the main cross-section of the present invention;

[0017] Figure 2 This is a schematic diagram of the separation structure of the upper and lower molds of this utility model;

[0018] Figure 3 This is a schematic diagram of the mold closing structure of the upper and lower molds of this utility model;

[0019] Figure 4 This is a three-dimensional structural diagram of the movable tube, rack, and ejector plate of this utility model;

[0020] Figure 5 This utility model Figure 1 Enlarged structural diagram at point A in the middle;

[0021] Figure 6 This utility model Figure 1 Enlarged structural diagram at point B.

[0022] In the diagram: 1. Base; 2. Lower mold; 3. Upper mold; 4. Fixing rod; 5. Threaded rod; 6. Connecting block; 7. Positioning rod; 8. Positioning hole; 9. Movable tube; 10. Connecting hose; 11. Driving gear; 12. Driven gear; 13. Rack; 14. Fitting block; 15. Ejector plate; 16. Return spring. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Please see Figures 1-6 This utility model provides the following technical solution: a sand casting mold for valve castings;

[0025] Example 1: To address the problem that the existing technology lacks an ejection mechanism, forcing the removal of castings only by manual or other non-professional methods, thus increasing labor costs, and that manual removal makes it difficult to ensure the uniformity and accuracy of force application, easily leading to uneven stress on the castings, resulting in defects such as deformation and cracking, and reducing the yield of castings, the following solution is disclosed. Please refer to the following for details. Figures 1-6 As shown, the system includes a base 1, a lower mold 2 fixed to the upper surface of the base 1, and an upper mold 3 positioned above the lower mold 2. Cavities are formed on the opposite surfaces of the upper mold 3 and the lower mold 2, and a sand inlet is formed at the top of the upper mold 3. A motor is installed at the left end of the upper base 1. The system also includes: a threaded rod 5 connected to a bearing on the left side of the upper surface of the base 1, and a fixing rod 4 fixed to the right side of the upper surface of the base 1. Connecting blocks 6 are fitted onto the outer sides of both the fixing rod 4 and the threaded rod 5. The top of the threaded rod 5 is fixedly connected to the output end of the motor. The left connecting block 6 is threadedly connected to the movable tube 9, and the right connecting block 6 is slidably connected to the fixing rod 4. The outer side of the upper mold 3 is connected to the two connecting blocks 6. The threaded rod 5 is fixedly connected with a drive gear 11 sleeved on the outer side of the lower end. A rack 13 is provided inside the lower mold 2 below the cavity. The left end of the rack 13 extends out of the outer surface of the lower mold 2 and is meshed with the drive gear 11. A fitting block 14 is fixed on the top right side of the rack 13. An ejector plate 15 is connected inside the lower mold 2 below the cavity. The top of the fitting block 14 and the bottom of the ejector plate 15 are inclined and fit against the inclined surface of the ejector plate 15. Both ejector plates 15 are slidably disposed inside the lower mold 2. A return spring 16 is installed between the outer side of the two ejector plates 15 and the inside of the lower mold 2.

[0026] The motor drives the threaded rod 5 to rotate forward, causing the upper mold 3 to move downwards on the threaded rod 5 and the fixed rod 4 via the connecting block 6, and close with the lower mold 2. Molten metal is then injected into the mold cavity through the sand inlet. Due to gravity, the liquid metal flows within the cavity, gradually filling it. The liquid metal gradually dissipates heat and solidifies within the cavity. As the temperature decreases, the liquid metal transforms into solid metal, forming the initial shape of the valve casting. Then, after the valve casting has completely solidified and cooled, the motor drives the threaded rod 5 to rotate in the reverse direction, simultaneously... The moving gear 11 drives the meshing rack 13 to move to the right, and drives the contact block 14 to press the ejector plate 15, causing the ejector plate 15 to move upward. This allows the valve casting in the sand mold to be ejected smoothly and quickly, avoiding casting damage, deformation, or sand mold destruction caused by difficult demolding. This greatly improves the casting yield and production efficiency. Then, when the motor drives the threaded rod 5 to rotate in the forward direction, the rack 13 moves to the right, and the contact block 14 stops pressing the ejector plate 15. The ejector plate 15 is then reset under the elastic force of the return spring 16, making it easy to use for the next ejection.

[0027] Example 2: Unlike Example 1, this example uses a positioning rod 7 inserted into the positioning hole 8 to ensure accurate alignment of the upper mold 3 and the lower mold 2 during the mold closing process. See details... Figure 1 and Figure 2 As shown, positioning rods 7 are fixed at equal intervals at the four corners of the bottom of the upper mold 3, and positioning holes 8 are opened at equal intervals around the top of the lower mold 2. The positions of the positioning rods 7 and the positioning holes 8 correspond one-to-one, and the positioning rods 7 and the positioning holes 8 are connected by an insertion.

[0028] When the upper mold 3 moves downward and closes with the lower mold 2, the positioning rod 7 is inserted into the positioning hole 8, thereby ensuring that the upper mold 3 and the lower mold 2 are accurately aligned during the mold closing process.

[0029] Example 3: Unlike Example 2, this example utilizes multiple nozzles on the movable pipe 9 to cool the molded valve casting by blowing air. See details... Figures 1-5 As shown, a movable tube 9 is rotatably connected between the threaded rod 5 and the lower mold 2 on the upper surface of the base 1. A driven gear 12 is fixedly sleeved on the outer side of the lower end of the movable tube 9. Spray nozzles are installed at equal intervals on the outer side of the movable tube 9 away from the driven gear 12. A connecting hose 10 is fixed to the end of the movable tube 9 away from the driven gear 12. The movable tube 9 is arranged in an inverted "L" shape. The driven gear 12 and the driving gear 11 are meshed. The end of the connecting hose 10 away from the movable tube 9 is connected to an external air pump.

[0030] The external air pump is started, and the generated gas enters the movable tube 9 through the connecting hose 10. When the drive gear 11 rotates, it drives the meshing driven gear 12 to rotate, causing the movable tube 9 to rotate between the upper mold 3 and the lower mold 2. At this time, multiple nozzles on the movable tube 9 blow air to cool the formed valve casting, thereby accelerating the cooling speed of the casting, shortening its cooling time, and thus shortening the entire production cycle and improving production efficiency. Then, as the upper mold 3 continues to rise, the movable tube 9 will continue to rotate and will no longer be between the upper mold 3 and the lower mold 2, making it easier for subsequent workers to remove the formed valve casting.

[0031] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0032] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sand casting mold for valve castings, comprising a base (1), a lower mold (2) fixed on the upper surface of the base (1), and an upper mold (3) disposed above the lower mold (2), wherein cavities are formed on the opposite surfaces of the upper mold (3) and the lower mold (2), and a sand inlet is formed at the top of the upper mold (3), and a motor is installed on the left end of the upper base (1); characterized in that, Also includes: A threaded rod (5) is connected to the left bearing on the upper surface of the base (1), and a fixing rod (4) is fixed on the right side of the upper surface of the base (1). A connecting block (6) is sleeved on the outer side of both the fixing rod (4) and the threaded rod (5). A drive gear (11) is sleeved and fixed on the outer side of the lower end of the threaded rod (5). A rack (13) is provided inside the lower mold (2) below the cavity, and a fitting block (14) is fixed on the top right side of the rack (13). An ejector plate (15) is connected inside the lower mold (2) below the cavity.

2. The sand casting mold for valve castings according to claim 1, characterized in that: The top of the threaded rod (5) is fixedly connected to the output end of the motor. The connecting block (6) on the left side is threadedly connected to the movable tube (9). The connecting block (6) on the right side is slidably connected to the fixed rod (4). The outer side of the upper mold (3) is fixedly connected to the two connecting blocks (6).

3. The sand casting mold for valve castings according to claim 1, characterized in that: The left end of the rack (13) extends out of the outer surface of the lower mold (2), and the rack (13) and the drive gear (11) are meshed.

4. The sand casting mold for valve castings according to claim 1, characterized in that: The top of the bonding block (14) and the bottom of the ejector plate (15) are both inclined, and the bonding block (14) is in contact with the inclined surface of the ejector plate (15). Both ejector plates (15) are slidably disposed inside the lower mold (2). A return spring (16) is installed between the outer side of the two ejector plates (15) and the inside of the lower mold (2).

5. The sand casting mold for valve castings according to claim 1, characterized in that: Positioning rods (7) are fixed at equal intervals at the four corners of the bottom of the upper mold (3), and positioning holes (8) are opened at equal intervals around the top of the lower mold (2). The positions of the positioning rods (7) and the positioning holes (8) correspond one-to-one, and the positioning rods (7) and the positioning holes (8) are connected by insertion.

6. The sand casting mold for valve castings according to claim 1, characterized in that: The upper surface of the base (1) is rotatably connected between the threaded rod (5) and the lower mold (2) by a movable tube (9), and a driven gear (12) is sleeved and fixed on the outer side of the lower end of the movable tube (9). Spray nozzles are installed at equal intervals on the outer side of the movable tube (9) away from the driven gear (12), and a connecting hose (10) is fixed on the end of the movable tube (9) away from the driven gear (12).

7. A sand casting mold for valve castings according to claim 6, characterized in that: The movable tube (9) is arranged in an inverted "L" shape. The driven gear (12) and the driving gear (11) are meshed. The end of the connecting hose (10) away from the movable tube (9) is connected to an external air pump.

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