Large steel backing pouring system for eliminating casting stress

Abstract

The invention relates to the technical field of casting pouring, and discloses a large steel backing pouring system capable of eliminating casting stress, comprising: a pouring assembly comprising a pouring cup, a conveying buffer mechanism fixedly connected to the bottom of the pouring cup and used for conveying and buffering molten iron, and a filtering mechanism connected to the bottom of the conveying buffer mechanism and used for filtering the molten iron, the filtering mechanism is connected with a cross gate, and the top of the cross gate is connected with a plurality of sprue mechanisms used for casting forming. According to the invention, the problem of incomplete discharge of casting bubbles caused by insufficient exhaust of the cross gate during casting is reduced, the content of the casting bubbles is reduced, and the casting quality is improved; the layered mold filling operation of the molten iron is realized, the low-speed and stable pouring of the molten iron is realized, and the heat distribution of the molten iron is uniform, so that the simultaneous solidification in the product solidification process is realized, the shrinkage stress caused by the solidification sequence difference of the traditional nodular cast iron is further eliminated, and the problem of unqualified flatness caused by casting stress release after the large steel backing is processed is solved; and the large steel backing casting quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of casting pouring, and particularly relates to a large steel back pouring system for eliminating casting stress. Background Art

[0002] The large steel back is the steel back plate in automotive brake pads, and its main function is to fix the friction material and provide necessary strength and rigidity. The brake pad consists of three parts: the friction material, the adhesive, and the steel back. Among them, the quality of the steel back directly affects the performance and service life of the brake pad. A high-quality steel back should have high strength, good thermal conductivity, and wear resistance to ensure the stability and safety of the braking system;

[0003] The large steel back is usually produced by casting. Since the large steel back is a long strip-shaped thin plate structure, when using the traditional top-pouring method, because the molten iron is in a single direction during both the injection and cooling processes, the temperature of the large steel back is uneven during cooling, and the inconsistent cooling of the large steel back generates shrinkage stress. After casting, the stress is released during the machining of the casting, resulting in product deformation. Therefore, a large steel back pouring system for eliminating casting stress is proposed. Summary of the Invention

[0004] To solve the technical problems that the temperature of the large steel back is uneven during cooling, the inconsistent cooling of the large steel back generates shrinkage stress, and the stress is released during the machining of the casting after casting, resulting in product deformation, the present invention provides a large steel back pouring system for eliminating casting stress.

[0005] The present invention is realized by the following technical solutions: A large steel back pouring system for eliminating casting stress, comprising:

[0006] A casting assembly, which includes a pouring cup. A conveying and buffering mechanism for molten iron transportation and buffering is fixedly connected to the bottom of the pouring cup. A filtering mechanism for filtering molten iron is connected to the bottom of the conveying and buffering mechanism. The filtering mechanism is connected to a cross-riser, and multiple pouring mechanisms for casting forming are connected to the top of the cross-riser;

[0007] A sand core assembly, which includes a sand core for casting forming. Two casting forming cavities are reserved in the sand core. A shrinkage compensation cavity located on the sand core is arranged on the top side wall of the casting forming cavity. An exhaust port of the sand core penetrates through the top of the casting forming cavity, and multiple channels are sequentially distributed and penetrate through the bottom of the casting forming cavity;

[0008] A compensation and exhaust assembly, which includes a riser arranged on the top of the sand core, and a docking pipe for docking with the exhaust port is arranged at the bottom of the riser.

[0009] As a further improvement of the above solution, the conveying and buffering mechanism includes a runner 1 fixedly connected to the bottom of the pouring cup. The other end of the runner 1 is fixedly connected to a sprue 1. A choke runner is fixedly connected to one side of the bottom of the sprue 1. A sprue 2 is fixedly connected to one side of the bottom of the choke runner.

[0010] As a further improvement of the above solution, the filtering mechanism includes a dispersion cover fixedly connected to the bottom of the conveying buffer mechanism, the bottom of the dispersion cover is connected to a collecting cover fixedly connected to the cross runner, and a filter is installed between the dispersion cover and the collecting cover.

[0011] As a further improvement of the above solution, the gate mechanism includes an inner gate sleeved with the channel, and a reinforcing rib fixedly connected to the cross runner is connected to the outer side of the inner gate.

[0012] As a further improvement of the above scheme, the cross-sections of the inner gate and the channel are both rectangular structures, the ratio of the total length of the inner gate to the total length of the product is greater than or equal to 0.6, the thickness of the inner gate is 20-40% of the wall thickness of the casting, and at least three groups of inner gates are arranged at the bottom of the same casting molding cavity.

[0013] As a further improvement of the above solution, the inner wall of the runner is provided with staggered baffles.

[0014] As a further improvement of the above solution, the filter adopts a foam ceramic filter, and the dispersion cover and the collection cover both adopt a bucket-shaped structure.

[0015] As a further improvement of the above scheme, the sand core is provided with a hoisting heat dissipation mechanism, which includes a U-shaped bracket fixedly connected to the sand core and heat-conducting tubes pre-buried in the sand core and distributed on both sides of the casting molding cavity. Both ends of the bracket are equipped with conduits fixedly connected to the sand core, and one end of the conduit extends into the sand core and is connected to the heat-conducting tube.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention uses a flow-blocking method on the sprue and the runner to reduce the flow rate and pressure of the molten iron in the runner, reduce the scouring force of the molten iron on the runner, and at the same time enable the molten iron to fully fill the mold in the runner and discharge the gas in the runner, thereby reducing the problem of incomplete bubble discharge of the casting caused by insufficient exhaust of the runner during casting, reducing the bubble content of the casting, and improving the quality of the casting.

[0018] 2. The present invention utilizes multiple groups of open inner gates arranged at the bottom of the cavity to further reduce the filling flow rate. The molten iron is filled in a slow upward manner to disperse the flow rate of the molten iron, realize layered filling operation of the molten iron, and realize low-speed and stable pouring of the molten iron. The heat of the molten iron is evenly distributed, thereby ensuring that the product solidifies simultaneously during the solidification process, further eliminating the shrinkage stress caused by the difference in solidification sequence of traditional ductile iron, solving the problem of unqualified flatness caused by casting stress release after the large steel back is processed, and improving the casting quality of the large steel back. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1Schematic structural diagram of a large steel back pouring system for eliminating casting stress provided by the present invention;

[0020] Figure 2 Schematic structural diagram of the sand core assembly provided by the present invention;

[0021] Figure 3 Schematic structural diagram of the casting assembly provided by the present invention;

[0022] Figure 4 Schematic structural diagram of the compensation exhaust assembly provided by the present invention.

[0023] Main symbol description:

[0024] 1. Casting assembly; 2. Sand core assembly; 3. Compensation exhaust assembly; 11. Sprue cup; 12. Runner 1; 13. Vertical runner 1; 14. Choke runner; 15. Vertical runner 2; 16. Dispersion cover; 17. Collection cover; 18. Filter; 19. Cross runner; 20. Gate mechanism; 21. Sand core; 22. Casting cavity; 23. Shrinkage compensation cavity; 24. Exhaust port; 25. Channel; 31. Riser; 33. Docking pipe; 41. Inner gate; 42. Reinforcing rib. Detailed implementation manners

[0025] Next, in combination with the accompanying drawings and specific implementation manners, the present invention will be further described. It should be noted that, on the premise of no conflict, any combination of the following described embodiments or technical features can form a new embodiment.

[0026] Embodiment 1:

[0027] Please refer to Figures 1 - 4 , a large steel back pouring system for eliminating casting stress in this embodiment includes:

[0028] Casting assembly 1, which includes a sprue cup 11. A conveying and buffering mechanism for molten iron transportation and buffering is fixedly connected to the bottom of the sprue cup 11. A filtering mechanism for filtering molten iron is connected to the bottom of the conveying and buffering mechanism. The filtering mechanism is connected to a cross runner 19. Multiple gate mechanisms 20 for casting forming are connected to the top of the cross runner 19. Baffle plates are arranged in a staggered manner on the inner wall of the cross runner 19;

[0029] The conveying and buffering mechanism includes a runner 12 fixedly connected to the bottom of the sprue cup 11. The other end of the runner 12 is fixedly connected to a vertical runner 13. A choke runner 14 is fixedly connected to one side of the bottom of the vertical runner 13. A vertical runner 2 is fixedly connected to one side of the bottom of the choke runner 14;

[0030] The filtering mechanism includes a dispersion cover 16 fixedly connected to the bottom of the conveying and buffering mechanism. The bottom of the dispersion cover 16 is connected to a collecting cover 17 fixedly connected to the cross-riser 19. A filter 18 is installed between the dispersion cover 16 and the collecting cover 17. The filter 18 uses a foam ceramic filter. Both the dispersion cover 16 and the collecting cover 17 adopt a funnel-shaped structure;

[0031] The gate mechanism 20 includes an ingate 41 sleeved on the channel 25. The outside of the ingate 41 is connected to a reinforcing rib 42 fixedly connected to the cross-riser 19. The cross-sections of both the ingate 41 and the channel 25 are rectangular structures. The ratio of the total length of the ingate 41 to the total length of the product is greater than or equal to 0.6. The thickness of the ingate 41 is 20-40% of the wall thickness of the casting. At least three groups of ingates 41 are arranged at the bottom of the same casting cavity 22. The ingate 41 adopts an open design. During casting, the molten iron flows along the pouring cup 11, the first runner 12, and the first runner 12 into the choke runner 14. The choke runner 14 is used to block the flow of the molten iron, reduce the scouring force of the molten iron on the runner, and buffer the flow rate of the molten iron. Then the molten iron flows into the filtering mechanism, and the foam ceramic filter filters the molten iron. The filtered molten iron flows into the cross-riser 19 and is first blocked by the choke plate in the cross-riser 19 to reduce the flow rate of the molten iron and the pressure of the second downsprue 15 on the molten iron in the cross-riser 19, so as to ensure smooth filling in the bottom cross-riser 19 and reduce the flow rate of the molten iron at the ingate 41 position. Then, the casting cavity 22 is cast in a bottom-up manner along multiple groups of ingates 41; by using multiple groups of open ingates 41 distributed at the bottom of the casting cavity 22, the filling flow rate is further reduced, enabling the molten iron to slowly fill upward from the bottom of the casting cavity 22, dispersing the flow rate of the molten iron entering the casting cavity 22, realizing the layered filling operation of the molten iron, and realizing the low-speed and stable pouring of the molten iron flowing into the casting cavity 22 of the sand core 21. The heat distribution of the molten iron is uniform, so as to ensure that the product solidifies simultaneously during the solidification process, further eliminate the shrinkage stress caused by the difference in the solidification sequence of traditional ductile iron, solve the problem of unqualified flatness caused by the release of casting stress after the machining of the large steel back, and improve the casting quality of the large steel back;

[0032] The sand core assembly 2 includes a sand core 21 for casting the formed part. The sand core 21 is provided with two casting cavities 22. The top side wall of the casting cavity 22 is provided with a shrinkage compensation cavity 23 located on the sand core 21. The top of the casting cavity 22 penetrates through the exhaust port 24 of the sand core 21. The bottom of the casting cavity 22 penetrates through multiple groups of sequentially distributed channels 25. The two casting cavities 22 on the sand core 21 can separate the two castings to be cast, realizing the production in the way of one mold with two parts, and using the shrinkage compensation cavity 23 to perform shrinkage compensation on the casting from the top;

[0033] Compensation exhaust assembly 3, which includes a riser 31 arranged at the top of the core 21. A docking pipe 33 connected to the exhaust port 24 is arranged at the bottom of the riser 31, and feeding and exhausting operations are carried out at the top of the core 21.

[0034] Embodiment 2:

[0035] Based on Embodiment 1, the further improvement of this embodiment lies in that: the core 21 is provided with a hoisting and heat dissipation mechanism. The hoisting and heat dissipation mechanism includes a U-shaped bracket fixedly connected to the core 21 and heat conduction pipes embedded inside the core 21 and distributed on both sides of the casting cavity 22. Both ends of the bracket are installed with conduits fixedly connected to the core 21. One end of the conduit extending into the core 21 is communicated with the heat conduction pipe. During use, the core 21 is transported and handled by the bracket. At the same time, when the core 21 is cast, the heat inside can be quickly discharged through the heat conduction pipe, so that the temperature reduction inside and outside the product is stable and consistent, further ensuring that the product solidifies simultaneously during the solidification process, further eliminating the shrinkage stress caused by the difference in the solidification sequence of traditional ductile iron, increasing the cooling speed of the molten iron, and increasing the casting speed of the product.

[0036] The present invention uses the method of setting flow resistance on the sprue and the runner to reduce the flow rate and pressure of the molten iron in the runner, reduce the scouring force of the molten iron on the runner, and at the same time enable the molten iron to be fully filled in the runner, discharge the gas in the runner, reduce the problem of incomplete discharge of casting bubbles caused by insufficient exhaust in the runner during casting, reduce the bubble content of the casting, and improve the quality of the casting; by using multiple groups of open ingates arranged at the bottom of the cavity, the filling flow rate is further reduced. The molten iron is filled in a slow upward manner, the flow rate of the molten iron is dispersed, and the layered filling operation of the molten iron is realized, realizing the low-speed and stable pouring of the molten iron, and the heat distribution of the molten iron is uniform, so as to ensure that the product solidifies simultaneously during the solidification process, further eliminating the shrinkage stress caused by the difference in the solidification sequence of traditional ductile iron, solving the problem of unqualified flatness caused by the release of casting stress after the machining of the large steel back, and improving the casting quality of the large steel back.

[0037] The above-mentioned embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention belong to the scope of protection required by the present invention.

Claims

1. A large steel back casting system for eliminating casting stress, characterized in that, include: A casting assembly includes a pouring cup, a conveying and buffering mechanism for conveying and buffering molten iron is fixedly connected to the bottom of the pouring cup, a filtering mechanism for filtering the molten iron is connected to the bottom of the conveying and buffering mechanism, a cross runner is connected to the filtering mechanism, and a plurality of groups of pouring mechanisms for casting molding are connected to the top of the cross runner; A sand core assembly, comprising a sand core for casting molding, wherein the sand core is provided with two groups of casting molding cavities, the top side wall of the casting molding cavity is provided with a shrinkage compensation cavity located on the sand core, the top of the casting molding cavity is penetrated with an exhaust port of the sand core, and the bottom of the casting molding cavity is penetrated with multiple groups of channels distributed in sequence; The compensating exhaust component comprises a riser arranged on the top of the sand core, and a butt pipe butted with the exhaust port is arranged at the bottom of the riser.

2. The large steel back casting system for eliminating casting stress according to claim 1, characterized in that, The conveying buffer mechanism includes a pouring channel 1 fixedly connected to the bottom of the pouring cup, a straight pouring channel 1 fixedly connected to the other end of the pouring channel 1, a flow-blocking pouring channel fixedly connected to one side of the bottom of the straight pouring channel 1, and a straight pouring channel 2 fixedly connected to one side of the bottom of the flow-blocking pouring channel.

3. A large steel back casting system for eliminating casting stress as described in claim 1, characterized in that, The filtering mechanism comprises a dispersion cover fixedly connected to the bottom of the conveying buffer mechanism, a collecting cover fixedly connected to the cross runner is connected to the bottom of the dispersion cover, and a filter is installed between the dispersion cover and the collecting cover.

4. A large steel back casting system for eliminating casting stress as described in claim 1, characterized in that, The gate mechanism comprises an inner gate sleeved with the channel, and a reinforcing rib fixedly connected to the runner is connected to the outer side of the inner gate.

5. A large steel back pouring system for eliminating casting stress according to claim 4, characterized in that, The cross-sections of the inner gate and the channel are both rectangular structures, the ratio of the total length of the inner gate to the total length of the product is greater than or equal to 0.6, the thickness of the inner gate is 20-40% of the casting wall thickness, and at least three groups of inner gates are arranged at the bottom of the same casting cavity.

6. The large steel back casting system for eliminating casting stress according to claim 1, characterized in that, The inner wall of the runner is provided with staggeredly distributed baffles.

7. The large steel back casting system for eliminating casting stress according to claim 3, characterized in that, The filter adopts a foam ceramic filter, and the dispersion cover and the collection cover both adopt a bucket-shaped structure.

8. A large steel back casting system for eliminating casting stress as described in claim 1, characterized in that, The sand core is provided with a hoisting heat dissipation mechanism, which includes a U-shaped bracket fixedly connected to the sand core and heat-conducting pipes pre-buried in the sand core and distributed on both sides of the casting molding cavity. Both ends of the bracket are equipped with conduits fixedly connected to the sand core, and one end of the conduit extends into the sand core and is connected to the heat-conducting pipe.

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