Sand core compacting method and device

Abstract

The invention discloses a sand core compacting device and a compacting method, the sand core compacting device is used for compacting a sand core in a mold, the compacting device comprises a mold cavity, a mold block assembly arranged at the bottom of the mold cavity and a pressing cover plate assembly arranged above the mold block assembly, and the space between the pressing cover plate assembly and the mold block assembly is filled with core sand. The split type air bag assembly is arranged between the upper end of the core sand and the lower pressing cover plate assembly and comprises a plurality of air bags which are arranged separately, and every two adjacent air bags are communicated with each other; the air source is used for inflating the split type air bag assembly; and the air inflation connector is arranged on the side wall of the mold cavity, one end of the air inflation connector communicates with the air source, and the other end of the air inflation connector communicates with one of the air bags. According to the sand core compacting device and the compacting method provided by the invention, the compacting uniformity of the sand core can be improved, and the quality of the sand core is improved.

Description

Technical Field

[0001] The present invention relates to the field of casting technology, and particularly relates to a core compaction method and device. Background Art

[0002] Currently, in the market, core making for sample part development is usually carried out by means such as 3D printing, manual core making, or subtractive manufacturing. The process flow of manual core making is as follows: First, material preparation is carried out. Then, the mixed core sand is manually filled into the mold. Then, a pressing plate is pressed into the mold by equipment (or manually) to compact the core sand. After that, curing is carried out. Finally, the core is taken out of the mold after curing is completed.

[0003] As Figure 1 shown, there are often mold blocks 200 at the bottom of the mold 100, and there is a certain height difference between the mold blocks 200 according to the different shapes of the required cores. The existing manual core making usually uses manual or equipment for compaction. Manual compaction, on the one hand, consumes labor and time costs. On the other hand, the force applied each time is uneven, so the compaction effect of the entire core is different; equipment compaction generally uses a whole pressing plate 300 for compaction. If there are mold blocks 200 with a large height difference under the pressing plate 300, the pressing plate 300 will stop when pressing on the higher mold block 200. Then, it is very easy to cause the core sand 400 at the high place of the mold block 200 to have extremely high compaction degree, while the core sand 400 at the low place is not compacted. As shown in Figure 2, when using the pressing plate 300 for compaction, since the pressing plate 300 is rigid as a whole, the downward movement of the pressing plate 300 will be blocked at the position of the mold block 200, resulting in the compaction process of the core sand 400 on the side of the mold block 200 being affected.

[0004] Influences caused by uneven compaction degree of the above method:

[0005] (1) It leads to inconsistent core strength. The core strength in some areas is poor, which will directly affect the quality of the casting, resulting in quality problems such as structural damage, formation of air holes, and sand sticking.

[0006] (2) The rejection rate increases, causing waste of materials and energy.

[0007] (3) The low-strength core will directly affect the collapsibility of the core, increase the difficulty of the subsequent sand cleaning process of the casting, and prolong the production cycle and labor cost. Summary of the Invention

[0008] Based on the above problems, the purpose of the present invention is to provide a core compaction method and device, which can improve the uniformity of core compaction.

[0009] In order to overcome the deficiencies of the prior art, one of the technical solutions provided by the present invention is:

[0010] A core compaction device for compacting cores in a mold, including a mold cavity, a block assembly arranged at the bottom of the mold cavity, and a pressing cover plate assembly arranged above the block assembly. Core sand is filled between the pressing cover plate assembly and the block assembly. It further includes:

[0011] A split airbag assembly arranged between the upper end of the core sand and the pressing cover plate assembly, including a plurality of separately arranged airbags that are interconnected between adjacent airbags;

[0012] An air source for inflating the split airbag assembly;

[0013] An inflation joint arranged on the side wall of the mold cavity, with one end of the inflation joint connected to the air source and the other end connected to one of the airbags.

[0014] In one embodiment, the airbag includes an airbag body, two first interfaces arranged at both ends of the airbag body in a first direction, and two second interfaces arranged at both ends of the airbag body in a second direction, where the first direction is perpendicular to the second direction.

[0015] In one embodiment, adjacent airbags are interconnected through a connector. The connector includes a body portion and two connecting portions arranged at both ends of the body portion. The two connecting portions and the body portion are sequentially connected to form an air flow channel, and the connecting portion is adaptively connected to the first interface / second interface.

[0016] In one embodiment, when a riser avoidance position is provided between two adjacent airbags, the adjacent airbags are connected through a connecting pipe.

[0017] In one embodiment, the inflation joint includes a fixing portion fixed to the side wall of the mold cavity, a first joint portion arranged at one end of the fixing portion, and a second joint portion arranged at the other end of the fixing portion. The first joint portion, the fixing portion, and the second joint portion are sequentially connected to form an air flow channel. The second joint portion is adaptively connected to the first interface / second interface, and the outer diameter of the first joint portion is greater than that of the second joint portion.

[0018] In one embodiment, the first joint portion is connected to the air source through a connecting pipe, and an inflation valve is provided on the connecting pipe.

[0019] In one embodiment, the pressing cover plate assembly includes a cover plate and a driving component for driving the cover plate to move up and down.

[0020] In one embodiment, a sealing ring is provided between the cover plate and the upper end of the mold cavity.

[0021] In order to overcome the deficiencies of the prior art, the second technical solution provided by the present invention is as follows:

[0022] A method for compacting a sand core, comprising the following steps:

[0023] Step S1, manually mix the sand, and fill the core sand into the mold cavity;

[0024] Step S2, lay a plurality of air bags on the upper end of the core sand, connect the interfaces between adjacent air bags through connectors. If a riser avoidance position is provided between two air bags, then the two air bags are connected through a communication pipe, and the interfaces that do not need to be connected to adjacent air bags are blocked with plugs, and connect one air bag close to the inflation joint on the mold cavity to the inflation joint;

[0025] Step S3, drive the cover plate to move downward through the driving component and abut against the upper end of the mold cavity, open the inflation valve, and introduce the compressed air provided by the air source into the plurality of air bags through the connecting pipe to compact the core sand;

[0026] Step S4, inflate the plurality of air bags for a period of time, deflate after compaction is completed, move the cover plate upward, and take out the plurality of air bags.

[0027] In one embodiment, after the core sand is compacted once by the plurality of air bags in step S4, the air bags are taken out, and then the plurality of mold cavities are stacked up and down, the core sand is filled into the mold cavity multiple times, and the plurality of air bags are placed above the core sand multiple times to compact the core sand multiple times.

[0028] The riser avoidance position in the above technical solution refers to the avoidance position provided to avoid the riser pouring system, and the function of the riser pouring system is to ensure the smooth filling of the mold cavity with molten metal.

[0029] Compared with the prior art, the advantages of the present invention are as follows:

[0030] 1. Multiple air bags are used for compaction. The multiple air bags are flexible. After the air bag above the mold block compacts the core sand, the air bags on the side of the mold block will not stop due to the stagnation of the air bag above the mold block and can continue to compact the core sand, thereby ensuring the uniformity of compaction;

[0031] 2. A plurality of separately arranged air bags are laid above the core sand, and the core sand is compacted by inflating the plurality of air bags. The expansion and contraction amount of the air bag corresponding to the mold block with a larger height can be adaptively reduced, and the expansion and contraction amount of the air bag corresponding to the mold block with a smaller height can be adaptively increased, so as to uniformly compact the core sand and improve the quality of the sand core;

[0032] 3. The structure of the air bag facilitates the connection between adjacent air bags in the first direction and the second direction. The air bags are connected through connectors, which can ensure the tightness of the laying of the plurality of air bags and improve the uniformity of compaction;

[0033] 4. When a riser avoidance position is set between the air bags, the air bags are connected by a communicating pipe, which can improve the flow rate of the air flow and the compaction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0035] Figure 1 Schematic structural diagram of a platen compressing core sand in the prior art;

[0036] Figure 2 Schematic partial state diagram of a platen compressing core sand in the prior art;

[0037] Figure 3 Schematic structural diagram of an embodiment of a core sand compacting device of the present invention;

[0038] Figure 4 Schematic cooperation structural diagram of a separated air bag assembly and a lower pressing cover plate assembly in an embodiment of the present invention;

[0039] Figure 5 Schematic structural diagram of an air bag in an embodiment of the present invention;

[0040] Figure 6 Schematic cross-sectional structural diagram of an air bag in an embodiment of the present invention;

[0041] Figure 7 Schematic structural diagram of a connector in an embodiment of the present invention;

[0042] Figure 8 Schematic cross-sectional structural diagram of a connector in an embodiment of the present invention;

[0043] Figure 9 Schematic structural diagram of the connection between air bags in an embodiment of the present invention;

[0044] Figure 10 Schematic laying structural diagram of a split air bag assembly in an embodiment of the present invention;

[0045] Figure 11 Schematic state diagram of a split air bag assembly compacting a core sand in an embodiment of the present invention;

[0046] Figure 12 Process flow chart of a core sand compacting method in an embodiment of the present invention;

[0047] Figure 13Schematic diagram of the state of the first compaction in the embodiment of the present invention;

[0048] Figure 14 Schematic diagram of the state of the second compaction in the embodiment of the present invention;

[0049] Wherein:

[0050] 100, mold; 200, mold block; 300, pressing plate; 400, core sand;

[0051] 1, mold cavity;

[0052] 2, mold block;

[0053] 3, cover plate;

[0054] 4, driving component;

[0055] 5, sealing ring;

[0056] 6, core sand;

[0057] 7, split airbag assembly; 7-1, airbag; 7-1a, airbag body; 7-1b, first interface; 7-1c, second interface; 7-2, connecting head; 7-2a, body part; 7-2b, connecting part; 7-3, connecting pipe;

[0058] 8, inflation joint;

[0059] 9, air source;

[0060] 10, connecting pipe;

[0061] 11, inflation valve. Detailed implementation manners

[0062] The above solution will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are for illustrating the present invention and not for limiting the scope of the present invention. The implementation conditions adopted in the embodiments can be further adjusted according to the conditions of specific manufacturers, and the implementation conditions not specified are usually those in conventional experiments.

[0063] Referring to Figure 3 and Figure 4 , which is a schematic structural diagram of an embodiment of the present invention, a core sand compaction device is provided for compacting core sand in a mold, including a mold cavity 1, a mold block assembly arranged at the bottom of the mold cavity 1, a lower pressing cover plate assembly arranged above the mold block assembly, a split airbag assembly 7, an air source 9 and an inflation joint 8, and core sand 6 is filled between the lower pressing cover plate assembly and the mold block assembly.

[0064] The split airbag assembly 7 is laid above the core sand 6 and below the lower pressing cover plate assembly, and includes a plurality of airbags 7-1 separated and arranged, and adjacent airbags 7-1 are communicated with each other.

[0065] As Figure 5 and Figure 6 shown, the airbag 7-1 includes an airbag body 7-1a, two first interfaces 7-1b arranged at both ends of the airbag body 7-1a in the first direction, and two second interfaces 7-1c arranged at both ends of the airbag body 7-1a in the second direction, where the first direction and the second direction are perpendicular to each other, the airbag 7-1 is in a capsule shape, the two first interfaces 7-1b are arranged at both axial ends of the airbag body 7-1a, and the two second interfaces 7-1c are arranged on both radial sides of the airbag 7-1a. It should be understood that airbags of other shapes can also be used, such as a cube shape, and the present invention is not limited. For ordinary subtractive core making, a plurality of airbags 7-1 laid above the core sand 6 are arranged in a rectangular array and cover the upper end surface of the core sand 6 to ensure the compaction density of the core sand 6. For the core 6 that needs to be poured with a riser, a riser avoidance position can be reserved between two airbags 7-1 at the corresponding position.

[0066] To ensure the compaction density of the airbag 7-1, as Figure 9 shown, adjacent airbags 7-1 are interconnected through a connector 7-2. As Figure 7 and Figure 8 shown, the connector 7-2 includes a body portion 7-2a and two connecting portions 7-2b arranged at both ends of the body portion 7-2a. The two connecting portions 7-1b and the body portion 7-2a are sequentially connected to form an air flow channel. The connecting portion 7-2b is adaptively connected to the first interface 7-1b / second interface 7-1c. The connecting portion 7-1b tapers outward from the body portion 7-2a and forms a plurality of frustum cones arranged at intervals along the axis to improve the connection stability with the first interface 7-1b / second interface 7-1c.

[0067] As Figure 10 shown, when a riser avoidance position is set between the airbags 7-1, to improve the inflation efficiency, two airbags 7-1 with the riser avoidance position set are connected through a communicating pipe 7-3, and the communicating pipe 7-3 can be a flexible pipe such as a silicone pipe.

[0068] An air source 9, used to inflate the split airbag assembly 7, generally uses a compressed air source, such as an air compressor.

[0069] An inflation joint 8 is provided on the side wall of the mold cavity 1. One end of the inflation joint 8 communicates with a gas source 9 and the other end is connected to one of the air bags 7-1. Specifically, the inflation joint 8 includes a fixing part fixed on the side wall of the mold cavity 1, a first joint part provided at one end of the fixing part, and a second joint part provided at the other end of the fixing part. The first joint part, the fixing part, and the second joint part are sequentially communicated to form an air flow channel. The second joint part extends to the inner wall of the mold cavity 1 and is adaptively connected to the first interface 7-1b / second interface 7-1c. The outer diameter of the first joint part is larger than that of the second joint part and extends to the outside of the mold cavity 1 for easy connection to the gas source 9.

[0070] In this example, the first joint part and the gas source 9 are connected through a connecting pipe 10, and an inflation valve 11 is provided on the connecting pipe 10 to control the on / off of the gas source 9.

[0071] The pressing cover plate assembly includes a cover plate 3 and a driving component 4 for driving the cover plate 3 to move up and down. The driving component 4 can adopt a cylinder, and the cylinder drives the cover plate 3 to approach or move away from the upper part of the split air bag assembly 7. In this example, after the pressing cover plate assembly moves down, it abuts against the upper end of the mold cavity 1. Thus, it is convenient to control the moving distance of the cover plate 3 to control the inflation degree of the air bag 7-1. It should be understood that in other embodiments, the cover plate 3 can also extend into the mold cavity 1.

[0072] To improve the sealing performance and prevent the core sand 6 from flushing out of the mold cavity 1 due to the breakage of the air bag 7-1, a sealing ring 5 is provided between the cover plate 3 and the upper end of the mold cavity 1. Specifically, a circumferential limiting groove is provided at the lower end of the cover plate 3, and the sealing ring 5 is arranged in the limiting groove.

[0073] The present invention also relates to a method for compacting a sand core, as Figure 12 shown, including the following steps:

[0074] Step S1: Manually mix the sand, and fill the core sand 6 into the mold cavity 1;

[0075] Step S2: Lay a plurality of air bags 7-1 on the upper end of the core sand 6. The interfaces between adjacent air bags 7-1 are connected through a connector 7-2. If a riser avoidance position is provided between two air bags 7-1, the two air bags 7-1 are connected through a communicating pipe 7-3. The interfaces that do not need to be connected to adjacent air bags 7-1 are blocked with plugs, and one air bag close to the inflation joint 8 on the mold cavity 1 is connected to the inflation joint 8;

[0076] Step S3: Drive the cover plate 3 to move down through the driving component 4 and abut against the upper end of the mold cavity 1, open the inflation valve 11, and introduce the compressed air provided by the gas source 9 into the plurality of air bags 7-1 through the connecting pipe 10 to compact the core sand 6;

[0077] Step S4: Inflate the multiple air bags 7-1 for a period of time, deflate them after being tightened, move the cover plate 3 upward, and take out the multiple air bags 7-1.

[0078] In step S4, when compacting a relatively thick core, after the core sand 6 is compacted once by the multiple air bags 7-1 (as Figure 13 shown), take out the air bags 7-1, then stack the multiple mold cavities 1 up and down, fill the mold cavities 1 with the core sand 6 multiple times, and place the multiple air bags 7-1 above the core sand 6 again to compact the core sand 6 multiple times (as Figure 14 shown in the schematic diagram of the state of secondary compaction), and repeat this process until the compaction is completed.

[0079] The working principle of the present invention is as follows:

[0080] After artificial sand mixing, fill the core sand 6 into the mold cavity 1, lay the multiple air bags 7-1 on the upper end of the core sand 6 and make them communicate with each other, then connect one air bag 7-1 close to the inflation joint 8 to the inflation joint 8, drive the cover plate 3 to move downward to the upper end of the mold cavity 1 through the driving component 4, inflate the multiple air bags 7-1, and compact the core sand 6. When using the multiple air bags 7-1 for compaction, the multiple air bags 7-1 are flexible. As Figure 11 shown, after the air bag 7-1 above the mold block 2 compacts the core sand 6, the air bag 7-1 on the left side of the mold block 2 will not stop due to the stagnation of the air bag 7-1 above the mold block 2 and can continue to compact the core sand 6, so as to ensure the uniformity of compaction. After the compaction is completed, move the cover plate 3 upward and take out the multiple air bags 7-1. For a relatively thick core, after one compaction, stack the multiple mold cavities 1 up and down, fill the mold cavities 1 with the core sand 6 multiple times, and place the multiple air bags 7-1 above the core sand 6 multiple times to compact the core sand 6 multiple times.

[0081] In summary, the compaction device and method can compact different positions of the core sand to different degrees according to the layout of the mold blocks, so as to ensure the uniformity of the core sand compaction degree.

[0082] The above examples are only used to illustrate the technical concept and characteristics of the present invention, and their purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. Any equivalent transformation or modification made according to the spirit of the present invention should be covered within the protection scope of the present invention.

Claims

1. A core compacting device for compacting a core within a mold, comprising a mold cavity, a mold block assembly disposed at the bottom of the mold cavity, and a downward pressing cover plate assembly disposed above the mold block assembly, with core sand filled between the downward pressing cover plate assembly and the mold block assembly, characterized in that Further included are: A split airbag assembly disposed between the upper end of the core sand and the lower pressing cover plate assembly, including a plurality of separately arranged airbags that are interconnected between adjacent airbags; An air source for inflating the split airbag assembly; An inflation joint provided on the side wall of the mold cavity, with one end of the inflation joint communicating with the air source and the other end communicating with one of the airbags.

2. The core compacting device according to claim 1, wherein: The airbag includes an airbag body, two first interfaces provided at both ends of the airbag body in a first direction, and two second interfaces provided at both ends of the airbag body in a second direction, where the first direction is perpendicular to the second direction.

3. The core compacting device according to claim 2, characterized in that: Adjacent airbags are interconnected via a connector. The connector includes a body portion and two connecting portions provided at both ends of the body portion. The two connecting portions and the body portion are sequentially connected to form an air flow channel, and the connecting portion is adaptively connected to the first interface / second interface.

4. The core compacting device according to claim 2, wherein: When a riser avoidance position is provided between two adjacent airbags, the two adjacent airbags are connected via a communicating pipe.

5. The core compacting device according to claim 4, characterized in that: The inflation joint includes a fixing portion fixed to the side wall of the mold cavity, a first joint portion provided at one end of the fixing portion, and a second joint portion provided at the other end of the fixing portion. The first joint portion, the fixing portion, and the second joint portion are sequentially connected to form an air flow channel. The second joint portion is adaptively connected to the first interface / second interface, and the outer diameter of the first joint portion is larger than that of the second joint portion.

6. The core compacting device according to claim 5, characterized in that: The first joint portion is connected to the air source via a connecting pipe, and an inflation valve is provided on the connecting pipe.

7. The core compacting device according to claim 1, characterized in that: The lower pressing cover plate assembly includes a cover plate and a driving component for driving the cover plate to move up and down.

8. The core compacting device according to claim 7, wherein: A sealing ring is provided between the cover plate and the upper end of the mold cavity.

9. A core compaction method, characterized in that, Including the following steps: Step S1, manually mix the sand and fill the core sand into the mold cavity; Step S2, lay a plurality of airbags on the upper end of the core sand, connect the interfaces between adjacent airbags via a connector. If a riser avoidance position is provided between two airbags, the two airbags are connected via a communicating pipe, and the interfaces that do not need to be connected to adjacent airbags are blocked with plugs. Connect one of the airbags near the inflation joint on the mold cavity to the inflation joint; Step S3, drive the cover plate to move downward by the driving component and abut against the upper end of the mold cavity, open the inflation valve, and introduce the compressed air provided by the air source into the plurality of airbags via the connecting pipe to compact the core sand; Step S4, inflate the plurality of airbags for a period of time, deflate after compaction is completed, move the cover plate upward, and take out the plurality of airbags.

10. The core compacting method according to claim 9, characterized in that: After the core sand is compacted once by the plurality of airbags in Step S4, take out the airbags, then stack the plurality of mold cavities up and down, fill the core sand into the mold cavity multiple times, and place the plurality of airbags above the core sand multiple times to compact the core sand multiple times.

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