Nodular cast iron evanescent mode sand box
By setting up a vacuum chamber and multiple exhaust channels in the ductile iron disappearing mold sand box, the vacuum pump is used to form a negative pressure space, which solves the problem of low gas discharge efficiency in disappearing mold casting, significantly reduces the pore risk of castings and improves castings quality.
Patent Information
- Application Number
- CN202420799124.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-17
- Publication Date
- 2025-01-17
- Estimated Expiration
- 2034-04-17
AI Technical Summary
During the disappearing mold casting process, the thermal action of the liquid metal causes the model to be pyrolyzed and gasified, resulting in a large amount of gas. The existing exhaust rate is low, resulting in the casting being prone to pores.
A ductile iron disappearing molded sand box is designed, with a vacuum cavity and multiple sets of exhaust passages connected to each other, equipped with a vacuum pump and a sealing system to form a negative pressure space to quickly discharge gas, and pass through multiple sets of exhaust passages during the casting process. Separate the gas from the screen to improve the gas discharge efficiency.
Through the design of multiple sets of exhaust passages and vacuum chambers, the gas discharge efficiency is significantly improved, the pore risks of the casting are reduced, and the quality of the casting is ensured.
Smart Images
Figure CN222359221U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of casting, in particular to a ductile iron lost foam sand box. Background Art
[0002] Lost foam casting is a solid casting method that uses a foam plastic mold with binder-free dry sand combined with vacuum technology.
[0003] Casting process: Foam models with similar size and shape to the casting are bonded together into a model cluster, coated with refractory paint and dried, buried in dry quartz sand for vibration molding, poured under negative pressure to vaporize the model, and liquid metal occupies the model position, which solidifies and cools to form a casting. This is a new casting method.
[0004] There are still defects: During the casting process, due to the thermal effect of the liquid metal, the model undergoes pyrolysis and gasification, which produces a large amount of gas. However, the existing exhaust rate is low and the gas cannot be quickly discharged from the mold, which poses a risk of pores in the casting.
[0005] Therefore need a kind of ductile iron lost foam sand box to solve above-mentioned problem. Utility Model Content
[0006] The utility model provides the following technical solution: a ductile iron lost foam sand box, comprising a body, a vacuum cavity is provided inside the body, a plurality of exhaust channels connected to the vacuum cavity are provided on the inner wall of the body, the plurality of exhaust channels are evenly distributed on the inner wall of the vacuum cavity, a vacuum pump is installed on the side wall of the body, and an exhaust port connected to the vacuum cavity is provided at the input end of the vacuum pump, and after the vacuum pump is started, a negative pressure space is formed inside the vacuum cavity;
[0007] The exhaust channel includes a branch pipe and an air intake port, a screen is installed inside the air intake port, a bracket is installed inside the branch pipe, and a sealing plate is attached to the side wall of the air intake port. The sealing plate and the bracket are connected by a first spring. During the casting process, when the internal pressure of the main body is greater than the internal pressure of the vacuum chamber, the exhaust channel opens to discharge the gas inside the main body.
[0008] Preferably, an active cavity is opened inside the bracket, and a central axis is inserted inside the active cavity, the other end of the central axis is connected to the sealing plate, and a second spring is connected between the central axis and the inner wall of the active cavity.
[0009] Preferably, the bracket is of hollow design.
[0010] Preferably, a cooling pipe is arranged inside the body, and the cooling pipe includes an inner pipe and an outer pipe. The inner pipe is laid in an S shape inside the body, and the outer pipe surrounds the outside of the body.
[0011] Preferably, a water pump is installed inside the outer pipe, and a heat exchanger is installed inside the outer pipe.
[0012] Preferably, the outer wall of the inner pipe is connected to multiple groups of cooling fins.
[0013] Preferably, a sand discharge port is provided at the bottom of the body, and a baffle is rotatably connected to the inner wall of the sand discharge port. A fixing groove is provided at the end of the baffle, and a fixing rod penetrating the body is inserted into the fixing groove.
[0014] Preferably, the end of the baffle is inclined incrementally from left to right, and the sand discharge port is configured to match the shape of the baffle.
[0015] Compared with the prior art, the beneficial effects of the utility model are:
[0016] The ductile iron lost foam sand box is provided with multiple sets of exhaust channels, which can exhaust gas from multiple positions, thereby accelerating the efficiency of exhausting gas inside the body;
[0017] A vacuum cavity is also provided, and a negative pressure space is formed inside the vacuum cavity. The exhaust channel separates the vacuum cavity from the inside of the body, forming a one-way channel for the body gas to flow to the inside of the vacuum cavity. During the casting process, when a large amount of gas is generated inside the body, a pressure difference is generated between the body and the vacuum cavity, and the exhaust channel is opened to quickly transfer the gas in the body to the inside of the vacuum cavity. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0019] Figure 1 It is a front view cross-sectional structural schematic diagram of the utility model;
[0020] Figure 2 For the utility model Figure 1 Schematic diagram of the state structure;
[0021] Figure 3 For the utility model Figure 1 Schematic diagram of the cross-section structure at MM;
[0022] Figure 4 For the utility model Figure 1 Enlarged structural diagram at A in the middle.
[0023] Description of the drawings: 100, main body; 110, vacuum chamber; 120, branch pipe; 121, bracket; 122, sealing plate; 123, first spring; 124, movable chamber; 125, central axis; 126, second spring; 130, air intake port; 140, screen; 150, air exhaust port; 160, vacuum pump; 210, cooling pipe; 211, inner pipe; 212, outer pipe; 220, water pump; 230, heat exchanger; 240, cooling fins; 310, sand discharge port; 320, baffle; 330, fixing groove; 340, fixing rod. DETAILED DESCRIPTION
[0024] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0025] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, in the embodiment of the utility model: a ductile iron lost foam sand box includes a body 100, a vacuum chamber 110 is provided inside the body 100, a plurality of exhaust channels connected to the vacuum chamber 110 are provided on the inner wall of the body 100, and the plurality of exhaust channels are evenly distributed on the inner wall of the vacuum chamber 110, a vacuum pump 160 is installed on the side wall of the body 100, and an exhaust port 150 connected to the vacuum chamber 110 is provided at the input end of the vacuum pump 160, and after the vacuum pump 160 is started, a negative pressure space is formed inside the vacuum chamber 110;
[0026] The exhaust channel includes a branch pipe 120 and an air intake port 130. A screen 140 is installed inside the air intake port 130. A bracket 121 is installed inside the branch pipe 120. A sealing plate 122 is attached to the side wall of the air intake port 130. The sealing plate 122 and the bracket 121 are connected by a first spring 123. During the casting process, when the internal pressure of the main body 100 is greater than the internal pressure of the vacuum chamber 110, the exhaust channel opens to discharge the internal gas of the main body 100.
[0027] In specific operation, the vacuum pump 160 is started, and the gas inside the vacuum chamber 110 is evacuated through the exhaust port 150, so that a negative pressure space is formed inside the vacuum chamber 110, and then due to the pressure difference between the vacuum chamber 110 and the inside of the main body 100, the exhaust channel is opened, and the gas enters the exhaust channel through the screen 140, and the dry sand is intercepted by the screen 140 and separated from the gas. The gas inside the main body 100 quickly enters the vacuum chamber 110 through the exhaust channel due to the pressure difference, and then is sucked out by the vacuum pump 160 through the exhaust port 150, completing the negative pressure of the main body 100 before pouring. Compared with the existing negative pressure method, the setting of multiple sets of exhaust channels improves the efficiency of the negative pressure before pouring.
[0028] During pouring, when the model inside the main body 100 decomposes and produces a large amount of gas, the pressure inside the main body 100 rises rapidly, the pressure difference between the vacuum chamber 110 and the main body 100 increases rapidly, the exhaust channel opens instantly, and the pressure inside the vacuum chamber 110 and the pressure inside the main body 100 are balanced in a short time, thereby quickly discharging half of the gas inside the main body 100. At the same time, the vacuum pump 160 is turned on at the moment of pouring, and the vacuum pump 160 simultaneously reduces the pressure inside the vacuum chamber 110, thereby being able to discharge most of the gas inside the main body 100 in a short time, greatly reducing the risk of air holes in the casting.
[0029] Principle of the exhaust channel: When the pressure inside the main body 100 is greater than the pressure inside the vacuum chamber 110, the sealing plate 122 is pushed to the left by the pressure difference, and the first spring 123 is squeezed and deformed. When the pressure inside the vacuum chamber 110 and the main body 100 is balanced, the elastic action of the first spring 123 can make the sealing plate 122 quickly reset to seal the air inlet 130.
[0030] An active cavity 124 is defined inside the bracket 121 , and a central axis 125 is inserted inside the active cavity 124 . The other end of the central axis 125 is connected to the sealing plate 122 . A second spring 126 is connected between the central axis 125 and the inner wall of the active cavity 124 .
[0031] Through the above design, the elastic force of the sealing plate 122 when it is reset and the stability of the sealing plate 122 when it moves left and right are further improved.
[0032] The bracket 121 is of hollow design.
[0033] The above design ensures that the gas can flow inside the branch pipe 120 .
[0034] A cooling pipe 210 is disposed inside the body 100 . The cooling pipe 210 includes an inner pipe 211 and an outer pipe 212 . The inner pipe 211 is laid in an S shape inside the body 100 , and the outer pipe 212 surrounds the outside of the body 100 .
[0035] Through the above design, cold water can quickly cool down the high-temperature dry sand after flowing through the inner pipe 211, thereby quickly cooling the formed casting, and the hot water after heat exchange will flow into the outer pipe 212 to dissipate heat, completing the heat exchange cycle.
[0036] A water pump 220 is installed inside the outer pipe 212 , and a heat exchanger 230 is installed inside the outer pipe 212 .
[0037] Through the above design, the water pump 220 can ensure the rapid circulation of the liquid inside the cooling pipe 210, and the heat exchanger 230 can exchange heat with the outflowing hot water and perform cooling again.
[0038] The outer wall of the inner pipe 211 is connected to a plurality of groups of cooling fins 240 .
[0039] In the above, the cooling fins 240 are made of metal with good thermal conductivity, which increases the contact area with the dry sand and accelerates the cooling efficiency.
[0040] A sand discharge port 310 is formed at the bottom of the body 100 , and a baffle 320 is rotatably connected to the inner wall of the sand discharge port 310 . A fixing groove 330 is formed at the end of the baffle 320 , and a fixing rod 340 penetrating the body 100 is inserted into the fixing groove 330 .
[0041] Through the above design, dry sand can be discharged from the bottom of the main body 100, thereby improving the efficiency and convenience of sand discharge.
[0042] The end of the baffle 320 is gradually inclined from left to right, and the sand discharge port 310 is configured to match the shape of the baffle 320 .
[0043] Through the above design, when the baffle 320 enters the sand discharge port 310 , the sealing effect on the bottom of the body 100 is ensured.
[0044] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any reference numeral in a claim should not be regarded as limiting the claim to which it relates.
Claims
1. A ductile iron lost foam sand box, comprising a body (100), characterized in that: A vacuum chamber (110) is provided inside the body (100); a plurality of exhaust channels connected to the vacuum chamber (110) are provided on the inner wall of the body (100); the plurality of exhaust channels are evenly distributed on the inner wall of the vacuum chamber (110); a vacuum pump (160) is installed on the side wall of the body (100); and an exhaust port (150) connected to the vacuum chamber (110) is provided at the input end of the vacuum pump (160); after the vacuum pump (160) is started, a negative pressure space is formed inside the vacuum chamber (110); The exhaust channel comprises a branch pipe (120) and an air inlet (130), a screen (140) is installed inside the air inlet (130), a bracket (121) is installed inside the branch pipe (120), and a sealing plate (122) is attached to the side wall of the air inlet (130), and the sealing plate (122) and the bracket (121) are connected by a first spring (123). During the casting process, when the internal pressure of the main body (100) is greater than the internal pressure of the vacuum chamber (110), the exhaust channel is opened to discharge the gas inside the main body (100).
2. A ductile iron lost foam sand box according to claim 1, characterized in that: An active cavity (124) is provided inside the bracket (121), and a central axis (125) is inserted inside the active cavity (124). The other end of the central axis (125) is connected to the sealing plate (122), and a second spring (126) is connected between the central axis (125) and the inner wall of the active cavity (124).
3. A ductile iron lost foam sand box according to claim 2, characterized in that: The support (121) is of hollow design.
4. The ductile iron lost foam sand box according to claim 1, characterized in that: A cooling pipe (210) is arranged inside the body (100), and the cooling pipe (210) comprises an inner pipe (211) and an outer pipe (212), wherein the inner pipe (211) is laid in an S shape inside the body (100), and the outer pipe (212) surrounds the outside of the body (100).
5. A ductile iron lost foam sand box according to claim 4, characterized in that: A water pump (220) is installed inside the outer pipe (212), and a heat exchanger (230) is installed inside the outer pipe (212).
6. A ductile iron lost foam sand box according to claim 4, characterized in that: The outer wall of the inner pipe (211) is connected to a plurality of groups of cooling fins (240).
7. A ductile iron lost foam sand box according to claim 6, characterized in that: The bottom of the body (100) is provided with a sand discharge port (310), and the inner wall of the sand discharge port (310) is rotatably connected with a baffle (320), the end of the baffle (320) is provided with a fixing groove (330), and a fixing rod (340) penetrating the body (100) is inserted into the fixing groove (330).
8. The ductile iron lost foam sand box according to claim 7, characterized in that: The end of the baffle (320) is inclined in an increasing manner from left to right, and the sand discharge port (310) is configured to match the shape of the baffle (320).