Core shooting method

Abstract

A core shooting method, comprising: arranging at least one air inlet line (2-1a) for a sand magazine (2) having at least two blow holes (3-1), wherein each air inlet line is arranged between at least two adjacent blow holes, and an axis of the air inlet line is positioned on a circle centered at a center of a blow hole adjacent thereto and having a radius of 20 to 150 mm. Adopting the core shooting method can reduce pressure loss, ensure sand core quality, and prevent the problem of sand blowback occurring during venting and sand grains entering air inlet channels.

Description

A sand-shooting method Technical Field

[0001] This invention relates to the field of casting technology, and in particular to a sand-shooting method. Background Technology

[0002] The working principle of a core shooter is mainly to mix different resins with core sand to form a core sand mixture with bonding ability. The core sand mixture is then injected into a core box, where the core is cured by means of catalyst catalysis or preheating of the core box. The core is then removed to obtain the finished core. For example, when a thermosetting resin is used, the core sand mixture containing the thermosetting resin is injected into a heated core box. The core is preheated and rapidly hardened to a certain thickness (approximately 5-10 mm) inside the core box, and then removed to form a high-quality core with a smooth surface and accurate dimensions.

[0003] As shown in Figure 1, the existing sand-shooting device includes an integrated valve 100 and a sand-shooting cylinder 200 that cooperates with the integrated valve 100. The integrated valve 100 is provided with an air inlet channel 101 and an air outlet channel 102. The air inlet channel 101 and the air outlet channel 102 are connected to the sand-shooting cylinder 200 through the same air hole. An exhaust screen 400 is provided in the air hole. A shooting plate 300 is installed at the lower end of the sand-shooting cylinder 200, and multiple nozzles 301 are provided on the shooting plate 300.

[0004] During sand injection, after the integrated valve 100 and the sand injection cylinder 200 are connected, compressed gas begins to enter through the air inlet channel 101 with the air outlet channel 102 closed. The compressed gas passes through the exhaust screen 400 and then pushes the sand particles through the core sand gaps, forming a sand-airflow. The sand-airflow is ejected from the nozzle at high speed. Simultaneously, the sand-airflow applies pressure to the core sand, making it compacted. The degree of compaction can be controlled by adjusting the compressed air pressure and the sand injection time.

[0005] After sand shooting, close the air inlet channel 101 and open the air outlet channel 102 to release the residual pressure inside the sand shooting cylinder 200, which can effectively avoid the problem of air suffocation.

[0006] However, the aforementioned sand-shooting device has the following drawbacks:

[0007] (1) The problem of residual sand exists. Existing typical sand-shooting cylinder structures often exhibit the phenomenon of residual sand remaining inside the cylinder after multiple sand-shooting cycles, preventing complete sand expulsion. The main reason for the residual sand problem is that the friction between sand particles causes an angle of repose, making it difficult for sand to be expelled. It is also related to the shape of the sand-shooting cylinder and the position and shape of the perforation hole. For example, if the internal channel structure of the sand-shooting cylinder has corners or narrow parts, the sand flow will be obstructed when passing through these places. For instance, when the sand flow changes direction, some of the kinetic energy of the sand will be lost, causing it to accumulate in the channel, thus generating residual sand. At the same time, the size and position of the perforation hole will also affect the complete expulsion of sand. If the outlet is too small, sand near the edge of the outlet will remain due to friction and other factors at the end of sand-shooting. Residual sand will cause waste, affect the quality of the sand core, and reduce the working efficiency of the core-making machine.

[0008] (2) The airflow path is too long during sand shooting, resulting in a large pressure loss. The sand shooting method is to enter the air from the top. The airflow path from the top of the core sand to the actual nozzle sand outlet is too long, resulting in airflow pressure loss. At the same time, the core sand is affected by gravity, and the state of the shot core sand is inconsistent, which leads to the instability of the sand shooting process and makes it very easy to cause the sand core to be shot incompletely.

[0009] (3) Since the intake and exhaust use the same exhaust screen, sand may stick to the exhaust screen during the exhaust stage; at the same time, if the exhaust screen is damaged, core sand can easily enter and cause blockage during the exhaust stage. Summary of the Invention

[0010] Based on the above problems, the purpose of this invention is to provide a sand-shooting method that can reduce the pressure loss during sand-shooting and ensure the quality of the sand core.

[0011] To overcome the shortcomings of the prior art, the technical solution provided by this invention is as follows:

[0012] A sand-shooting method, wherein at least one air inlet pipe is arranged for a sand-shooting cylinder having at least two perforations, wherein each air inlet pipe is arranged between at least two adjacent perforations and the air outlet is arranged close to the adjacent perforation, and the axis of the air inlet pipe is arranged on a circle with the center of the adjacent perforation and a radius of 20 to 150 mm.

[0013] In one embodiment, the distance between the plane where the outlet end of the air intake pipe and the corresponding inlet end of the perforation hole are located is 5 to 100 mm.

[0014] In one embodiment, the sand-shooting method employs a sand-shooting device comprising:

[0015] A sand-shooting barrel having a separately arranged air inlet channel and an air outlet channel, the air inlet channel including at least one air inlet pipe arranged inside the sand-shooting barrel;

[0016] An integrated valve is movably configured relative to the sand-shooting cylinder. The integrated valve has an air inlet chamber and an air outlet chamber arranged at intervals. The air inlet chamber is connected to the air inlet channel and has an air inlet screen at the air outlet end. The air outlet chamber is connected to the air outlet channel and has an air outlet screen at the air inlet end.

[0017] A firing plate is installed at the bottom of the sand-shooting cylinder, and the firing plate has at least two firing holes that communicate with the interior of the sand-shooting cylinder.

[0018] In one embodiment, the distance between the air outlet end of the air inlet pipe and the spray plate is 5 to 100 mm.

[0019] In one embodiment, the air intake channel further includes an airflow distribution chamber disposed in the upper part of the sand-shooting cylinder, the air intake ends of the plurality of air intake pipes are connected to the airflow distribution chamber, and the outer periphery of the air intake channel forms the air outlet channel.

[0020] In one embodiment, the sand-shooting cylinder includes a first cylinder and a second cylinder that are detachably connected vertically, the air intake channel extends from the first cylinder into the second cylinder, and the second cylinder is detachably connected to the shooting plate;

[0021] A first sealing ring is provided between the first cylinder and the second cylinder, and a second sealing ring is provided between the second cylinder and the injection plate.

[0022] In one embodiment, the outer periphery of the airflow distribution cavity is provided with a plurality of connecting ribs to connect the airflow distribution cavity to the first cylinder.

[0023] In one embodiment, the integrated valve includes a first support portion located on the outer periphery and a second support portion disposed on the inner periphery of the first support portion. The air inlet chamber is formed inside the second support portion, and the gap between the first support portion and the second support portion forms the air outlet chamber. The first support portion is provided with an air inlet communicating with the air inlet chamber and an air outlet communicating with the air outlet chamber.

[0024] In one embodiment, a mounting bracket is also included that is fixedly connected to the first support portion, the mounting bracket being disposed over the upper end of the sand-shooting cylinder.

[0025] In one embodiment, a third sealing ring is provided between the mounting bracket and the sand-shooting cylinder, and a fourth sealing ring is provided between the second support and the sand-shooting cylinder.

[0026] Compared with the prior art, the advantages of the present invention are:

[0027] 1. Compressed air is directed to the vicinity of the perforation hole to form a sand jet, reducing the airflow path and thus reducing the pressure loss caused by the airflow passing through the sand core, thereby ensuring the quality of the sand core;

[0028] 2. By using airflow to drive the bottom core sand out of the perforation hole, the core sand above the perforation hole can fall freely under the influence of gravity, effectively reducing the amount of residual sand accumulation from 30% to less than 5%, ensuring the environmental friendliness and precision of the equipment;

[0029] 3. The air intake and exhaust positions are designed with a height difference and completely isolate the air intake and exhaust channels, effectively avoiding the backflow of sand caused by the air trapped inside the gun barrel after sand shooting and the problem of sand entering the air intake channel. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 is a schematic diagram of the structure of a sand-shooting device in the prior art;

[0032] Figure 2 is a schematic diagram of an embodiment of the sand-shooting device used in the sand-shooting method of the present invention;

[0033] Figure 3 is a partial cross-sectional structural diagram of an embodiment of the present invention;

[0034] Figure 4 is a schematic diagram of the integrated valve in an embodiment of the present invention;

[0035] Figure 5 is a schematic diagram of the AA cross-sectional structure in Figure 4;

[0036] Figure 6 is a schematic diagram of the mounting bracket in an embodiment of the present invention;

[0037] Figure 7 is a schematic diagram of the BB cross-sectional structure in Figure 6;

[0038] Figure 8 is a schematic diagram of the distribution of gas pipelines in an embodiment of the present invention;

[0039] Among them: 100, integrated valve; 101, air inlet channel; 102, air outlet channel; 200, sand-shooting cylinder; 300, shooting plate; 301, nozzle; 400, exhaust net; 1, integrated valve; 1-1, first support part; 1-2, second support part; 1-2a, fourth limiting groove; 1-3, air inlet chamber; 1-4, air outlet chamber; 1-5, air inlet; 1-6, air outlet; 1-7, mounting bracket; 1-7a, third limiting groove; 2, sand-shooting cylinder; 2-1, first cylinder body; 2-1a, air inlet pipe; 2-1b, airflow distribution chamber; 2-1c, branch pipe; 2-1d, connecting rib; 2-2, second cylinder body; 3, shooting plate; 3-1, shooting hole; 4, driving component; 5, air inlet net; 6, air outlet net; 7, first sealing ring; 8, second sealing ring; 9. Third sealing ring; 10. Fourth sealing ring; 11. Sand core. Detailed Implementation

[0040] The above-described solution will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. The implementation conditions used in the embodiments may be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are generally those in routine experiments.

[0041] This invention relates to a sand-shooting method, which involves arranging at least one air inlet pipe for a sand-shooting cylinder having at least two perforations. Each air inlet pipe is positioned between at least two adjacent perforations, with its outlet end close to the adjacent perforation. The axis of the air inlet pipe is arranged on a circle with a radius of 20–150 mm centered on the center of the adjacent perforation. Preferably, the distance between the plane containing the outlet end of the air inlet pipe and the inlet end of the corresponding perforation is 5–100 mm. In this way, each perforation has a corresponding air inlet pipe that supplies compressed gas, enabling the formation of a gas-solid two-phase sand flow within the perforation, thereby improving the quality of the sand core.

[0042] Referring to Figures 2 and 3, which are schematic diagrams of the structure of the sand-shooting device used in the sand-shooting method of the present invention, a sand-shooting device is provided, including a sand-shooting cylinder 2, an integrated valve 1 movably disposed relative to the sand-shooting cylinder 2, and a shooting plate 3 installed at the bottom of the sand-shooting cylinder 2, wherein a plurality of shooting holes 3-1 are provided on the shooting plate 3.

[0043] The sand-shooting cylinder 2 has separate air inlet and outlet channels. The air inlet channels include multiple air inlet pipes 2-1a arranged within the sand-shooting cylinder 2. Each air inlet pipe 2-1a is positioned between at least two adjacent perforations 3-1, with its outlet end close to the adjacent perforation 3-1. The air inlet pipes 2-1a are arranged vertically, with their axis aligned on a circle R centered on the center of the adjacent perforation 3-1 and having a radius of 20–150 mm. Preferably, the distance L between the outlet end of the air inlet pipe 2-1a and the shooting plate 3 is 5–100 mm. This arrangement ensures that compressed gas is distributed to each perforation 3-1 via the air inlet pipes 2-1a without interference, reducing pressure loss and resulting in a higher gas content in the final sand stream. This effectively forms a gas-solid two-phase sand stream, ultimately improving the quality of the sand core.

[0044] Figure 8 shows a schematic diagram of using the same injection plate 3-1 to fabricate multiple sand cores 11. For a small sand core 11 with two injection holes 3-1, the air inlet pipe 2-1a is arranged between the two injection holes 3-1. For a large sand core 11 with multiple injection holes 3-1, the air inlet pipe 2-1a can be arranged between two adjacent injection holes 3-1 or between three adjacent injection holes 3-1. In other embodiments, the air inlet pipe can also be arranged between four or five adjacent injection holes, depending on the specific needs, and the present invention does not impose any limitations. It should be understood that in other embodiments, a separate sand core can be fabricated using a corresponding injection plate. For example, to fabricate a small sand core, two injection holes can be set on the injection plate. In this case, only one air inlet pipe needs to be set and arranged between the two injection holes.

[0045] To facilitate the installation of multiple air intake pipes 2-1a, the air intake channel also includes an airflow distribution chamber 2-1b fixed in the upper part of the sand-shooting cylinder 2. The air intake end of the air intake pipe 2-1a is connected to the airflow distribution chamber 2-1b via a branch pipe 2-1c, forming an air outlet channel on the outer periphery of the air intake channel.

[0046] To facilitate component replacement, the sand-shooting cylinder 2 includes a first cylinder 2-1 and a second cylinder 2-2 that are detachably connected. The air intake channel extends from the first cylinder 2-1 to the second cylinder 2-2, and the second cylinder 2-2 is detachably connected to the shooting plate 3.

[0047] To improve sealing performance, a first sealing ring 7 is provided between the first cylinder 2-1 and the second cylinder 2-2, and a second sealing ring 8 is provided between the second cylinder 2-2 and the injection plate 3. Specifically, a first limiting groove for installing the first sealing ring 7 is provided at the upper end of the second cylinder 2-2, and a second limiting groove for installing the second sealing ring 8 is provided at the lower end of the second cylinder 2-2.

[0048] To improve the stability of the air intake channel structure, multiple connecting ribs 2-1d are provided on the outer periphery of the airflow distribution cavity 2-1b to connect the airflow distribution cavity 2-1b with the first cylinder 2-1.

[0049] As shown in Figures 4 and 5, the integrated valve 1 is movably positioned relative to the sand-shooting cylinder 2. Specifically, it can be connected to a drive component 4, which moves the integrated valve closer to or away from the sand-shooting cylinder 2. The drive component 4 can be a cylinder. The integrated valve 1 has an air inlet chamber 1-3 and an air outlet chamber 1-4 arranged at intervals. The air inlet chamber 1-3 is connected to the air inlet channel and has an air inlet mesh 5 at its outlet end. The air outlet chamber 1-4 is connected to the air outlet channel and has an air outlet mesh 6 at its inlet end.

[0050] The integrated valve 1 includes a first support portion 1-1 located on the outer periphery and a second support portion 1-2 disposed on the inner periphery of the first support portion 1-1. An air inlet chamber 1-3 is formed inside the second support portion 1-2, and an air outlet chamber 1-4 is formed in the gap between the first support portion 1-1 and the second support portion 1-2. An air inlet 1-5 communicating with the air inlet chamber 1-3 and an air outlet 1-6 communicating with the air outlet chamber 1-4 are provided on the first support portion 1-1.

[0051] The air intake mesh 5 is welded and fixed to the inner wall of the second support part 1-2, and the air outlet mesh 6 has a ring structure and is arranged on the outer periphery of the second support part 1-2. The air outlet mesh 6 is fixed to the first support part 1-1 by screws.

[0052] As shown in Figures 6 and 7, in order to facilitate the connection between the integrated valve 1 and the sand-shooting cylinder 2, a mounting bracket 1-7 is also included, which is fixedly connected to the first support part 1-1. The mounting bracket 1-7 covers the upper end of the sand-shooting cylinder 2.

[0053] To improve sealing performance, a third sealing ring 9 is provided between the mounting bracket 1-7 and the sand-shooting cylinder 2, and a fourth sealing ring 10 is provided between the second support 1-2 and the sand-shooting cylinder 2. Specifically, a third limiting groove 1-7a is provided on the mounting bracket 1-7 to accommodate the third sealing ring 9, and a fourth limiting groove 1-2a is provided on the second support 1-2 to accommodate the fourth sealing ring 10.

[0054] The working principle of this invention is as follows:

[0055] The drive component 4 connects the integrated valve 1 to the sand-shooting cylinder 2. Compressed air is introduced through the air inlet 1-5 on the integrated valve 1. After passing through the air inlet mesh 5, the compressed air reaches the bottom of the first cylinder 2-1 via the air inlet pipe 2-1a, so that the sand in the sand-shooting cylinder 2 is ejected through the injection holes 3-1 on the injection plate 3 to complete the sand-shooting process. Extending the air inlet pipe 2-1a above the corresponding injection hole 3-1 can avoid mutual interference, reduce the airflow path, reduce pressure loss, reduce residual sand accumulation, and ensure the quality of the core shot. After sand-shooting is completed, the exhaust channel is opened to discharge excess gas from the sand-shooting cylinder 2. Because there is a height difference between the air inlet and exhaust positions, and the air inlet and exhaust channels are isolated from each other, the backflow of sand caused by air stagnation inside the sand-shooting cylinder 2 and the problem of sand entering the air inlet channel can be avoided.

[0056] In summary, this sand-shooting device can ensure the quality of sand shooting, reduce the accumulation of residual sand, and avoid backflow caused by air trapped inside the sand-shooting cylinder.

[0057] The above examples are merely illustrative of the technical concept and features of the present invention, intended to enable those skilled in the art to understand the content of the invention and implement it accordingly, and should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made according to the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A sand-shooting method, characterized in that: For a sand-shooting barrel with at least two perforations, at least one air inlet pipe is arranged, wherein each air inlet pipe is arranged between at least two adjacent perforations and the air outlet is located close to the adjacent perforation. The axis of the air inlet pipe is arranged on a circle with the center of the adjacent perforation and a radius of 20 to 150 mm.

2. The sand-shooting method according to claim 1, characterized in that: The distance between the plane where the outlet end of the intake pipe and the corresponding inlet end of the perforation hole are located is 5 to 100 mm.

3. The sand-shooting method according to claim 1, characterized in that, The sand-shooting device used in the sand-shooting method includes: A sand-shooting barrel having a separately arranged air inlet channel and an air outlet channel, the air inlet channel including at least one air inlet pipe arranged inside the sand-shooting barrel; An integrated valve is movably configured relative to the sand-shooting cylinder. The integrated valve has an air inlet chamber and an air outlet chamber arranged at intervals. The air inlet chamber is connected to the air inlet channel and has an air inlet screen at the air outlet end. The air outlet chamber is connected to the air outlet channel and has an air outlet screen at the air inlet end. A firing plate is installed at the bottom of the sand-shooting cylinder, and the firing plate has at least two firing holes that communicate with the interior of the sand-shooting cylinder.

4. The sand-shooting method according to claim 3, characterized in that: The distance between the air outlet end of the air inlet pipe and the spray plate is 5 to 100 mm.

5. The sand-shooting method according to claim 3, characterized in that: The air intake channel also includes an airflow distribution chamber located in the upper part of the sand-shooting cylinder, and the air intake ends of multiple air intake pipes are connected to the airflow distribution chamber. The outer periphery of the air intake channel forms the air outlet channel.

6. The sand-shooting method according to claim 5, characterized in that: The sand-shooting cylinder includes a first cylinder and a second cylinder that are detachably connected vertically. The air intake channel extends from the first cylinder into the second cylinder, and the second cylinder is detachably connected to the shooting plate. A first sealing ring is provided between the first cylinder and the second cylinder, and a second sealing ring is provided between the second cylinder and the injection plate.

7. The sand-shooting method according to claim 6, characterized in that: The outer periphery of the airflow distribution cavity is provided with multiple connecting ribs to connect the airflow distribution cavity to the first cylinder.

8. The sand-shooting method according to claim 3, characterized in that: The integrated valve includes a first support portion located on the outer periphery and a second support portion disposed on the inner periphery of the first support portion. The air inlet chamber is formed inside the second support portion, and the air outlet chamber is formed by the gap between the first support portion and the second support portion. The first support portion is provided with an air inlet communicating with the air inlet chamber and an air outlet communicating with the air outlet chamber.

9. The sand-shooting method according to claim 8, characterized in that: It also includes a mounting bracket fixedly connected to the first support portion, the mounting bracket being mounted on the upper end of the sand-shooting cylinder.

10. The sand-shooting method according to claim 9, characterized in that: A third sealing ring is provided between the mounting bracket and the sand-shooting cylinder, and a fourth sealing ring is provided between the second support and the sand-shooting cylinder.

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