Casting method for producing copper-iron bimetallic alloy worm gear

Abstract

The invention relates to a casting method for producing a copper-iron bimetallic alloy worm gear, which belongs to the technical field of casting processes and comprises the following steps: S1, prefabricating a copper sleeve; s2, a sand box is prepared; s3, the copper sleeves are boxed, and the copper sleeves are transferred between an upper branch box and a lower branch box; s4, pouring liquid iron; s5, taking out the liquid iron after the liquid iron is cooled and molded into cast iron; wherein in the step S2, the bottom of the upper box body and the top of the lower box body are each provided with an avoiding space, and the avoiding spaces extend to the projection plane of the copper sleeve in the plane; and in the step S4, the pouring temperature of the liquid iron is controlled according to a heat formula Q = c * m * delta t. The appropriate temperature is calculated according to the weight of the poured liquid iron, the avoiding space in the sand box enables the liquid iron to be cooled at the avoiding space and form a cast iron part overlapped with the projection parts of the upper and lower end faces of the copper sleeve, the flowing pressure when the liquid iron passes through the copper sleeve is reduced, and formation of a mutual melting layer between double metals is facilitated; the process can be simplified, the period can be shortened, the efficiency is improved, and the mutual melting layer is beneficial to improving the structural strength of bimetal.

Description

Technical Field

[0001] The invention belongs to the technical field of casting technology, in particular to a casting method for producing a copper-iron bimetallic alloy worm gear. Background Art

[0002] A press (including punch presses, hydraulic presses, etc.) is a general-purpose press that applies pressure to the workpiece to achieve processes such as cutting, punching, blanking, bending, riveting and forming. Depending on the power source and working principle, presses can be divided into many types, such as hydraulic presses, mechanical presses, pneumatic presses, screw presses, etc.

[0003] The copper worm gear castings used in press products are mainly made of CuAl10Ni, ZCuSn10P1, and ZCuAl10Fe3, and the overall structure is pure copper alloy. Since the cost of copper alloy is relatively high and is about 10 times the price of iron, the copper worm gears used in similar products on the market are all bimetallic structures, which are used to replace pure copper alloy structures. Under the conditions of use, the cost can be effectively reduced, and the average cost per ton can be reduced by nearly 40,000 yuan / ton.

[0004] In order to save costs, copper-steel bimetal is often used to replace thick copper worm gear parts, with a structure of steel core and copper outside. However, the processing flow is very complicated, requiring alkali boiling, pickling and distilled water cleaning of the steel billet, spraying borax solution after heating to a certain temperature, continuous heat preservation, casting, pouring copper liquid and transferring it to a high-temperature furnace for continuous heat preservation, with a long production cycle and low efficiency.

[0005] Only steel billets with good elongation can be used for the core. Iron billets cannot be used because they will be squeezed by the contraction of the external copper liquid and cracks will occur. At the same time, copper alloys are easy to absorb air and oxidize. Static casting with sand molds is very likely to produce defects such as pores and slag holes, and the scrap rate is extremely high. Therefore, the best casting method for copper alloys is centrifugal casting. Summary of the invention

[0006] In order to solve the problems of separation of joints and long process cycle and low efficiency in the prior art when manufacturing bimetallic alloy turbines, the present invention provides a casting method for producing copper-iron bimetallic alloy worm gears.

[0007] The present invention is achieved through the following technical solutions:

[0008] A casting method for producing a copper-iron bimetallic alloy worm gear comprises the following steps:

[0009] S1, prefabricated copper sleeve;

[0010] S2. Prepare the sand box, which has an upper and lower divided structure;

[0011] S3, copper sleeve box, transfer copper sleeve between upper and lower boxes;

[0012] S4, pouring, pouring liquid iron through the sand box sprue;

[0013] S5, cooling and molding, after the liquid iron is cooled and molded into cast iron, it is taken out from the sand box;

[0014] S6, external shaping, removing and grinding the cast iron parts protruding from the upper and lower end surfaces of the copper sleeve;

[0015] Wherein, in step S2, the bottom of the upper box body and the top of the lower box body are both provided with an escape space, and the escape space extends to the projection surface of the copper sleeve in the plane;

[0016] In step S4, the pouring temperature of the liquid iron is controlled according to the heat formula Q=c*m*Δt.

[0017] The appropriate temperature is calculated based on the weight of the poured liquid iron. The avoidance space in the sand box allows the liquid iron to cool here and form a cast iron part that overlaps with the projections of the upper and lower end surfaces of the copper sleeve, reducing the flow pressure of the liquid iron when passing through the copper sleeve, which is conducive to the formation of an intermetallic layer between the bimetallics; at the same time, it is convenient to provide marks for the subsequent removal and grinding operations. In summary, this method can simplify the process, shorten the cycle, and improve efficiency. The intermetallic layer helps to improve the structural strength of the bimetallic.

[0018] A further improvement of the present invention is that the vertical height of the escape space of the upper box is smaller than the vertical height of the escape space of the lower box. Reducing the escape space at the top reduces the cast iron at the top of the copper sleeve and increases the cast iron at the bottom, which helps to balance the temperature field and make the distribution of liquid iron in the cooling space more uniform.

[0019] A further improvement of the present invention is that the inner side surface of the copper sleeve is an arc surface protruding toward the space where the liquid iron is to be poured, which helps to increase the contact area between the sleeve and the cast iron and improve the structural strength of the mutual melting layer.

[0020] A further improvement of the present invention is that the mass ratio of the liquid iron to the copper sleeve is 3:1, and the liquid iron is 300 kg.

[0021] A further improvement of the present invention is that in step S4, the temperature of the liquid iron during pouring is 1300°C to 1400°C.

[0022] A further improvement of the present invention is that in step S2, a bottom core is laid on the inner bottom surface of the lower box body, and a middle hole mud core abutting against the upper box body and the lower box body is also provided in the sand box.

[0023] A further improvement of the present invention is that in step S2, a follow-up ring core is provided inside the upper box body, which is coaxial with the copper sleeve and constrains the cast iron forming. The follow-up ring core helps to increase the height of the cast iron above the inner ring of the copper sleeve. During the pouring process, the cast iron forming time can be appropriately extended, and time is reserved for the flow of liquid iron, so that the liquid iron composition is more evenly distributed.

[0024] A further improvement of the present invention is that the ends of the middle hole clay core are chamfered and extend into the upper box and the lower box respectively, thereby improving the stability of the middle hole clay core in the sand box and avoiding factors that affect the formation of cast iron during the pouring process.

[0025] A further improvement of the present invention is that a direct pouring gate is provided on the top surface of the upper box body, and the direct pouring gate is connected with the pouring inner cavity of the sand box through an inner gate.

[0026] A further improvement of the present invention is that the above-mentioned ingates are provided in plurality, the plurality of ingates are connected with the straight gate via a horizontal gate, and the horizontal gate is in an arc-shaped structure as a whole.

[0027] It can be seen from the above technical scheme that the beneficial effects of the present invention are: the appropriate temperature is calculated based on the weight of the poured liquid iron, the avoidance space in the sand box allows the liquid iron to cool here and form a cast iron part that overlaps with the projection of the upper and lower end surfaces of the copper sleeve, thereby reducing the flow pressure of the liquid iron when passing through the copper sleeve, which is conducive to the formation of an intermetallic layer between the bimetallics; at the same time, it is convenient to provide marks for the subsequent removal and grinding operations. In summary, this method can simplify the process, shorten the cycle, and improve efficiency, and the intermetallic layer helps to improve the structural strength of the bimetallic. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0029] Figure 1 It is a casting schematic diagram of a specific embodiment of the present invention.

[0030] Figure 2 It is a schematic diagram of a gate according to a specific embodiment of the present invention.

[0031] In the attached figure: 10, copper sleeve; 20, cast iron; 30, middle hole mud core; 40, straight gate; 50, horizontal gate; 60, inner gate. DETAILED DESCRIPTION

[0032] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in this specific embodiment. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of them. Based on the embodiments in this patent, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this patent.

[0033] As shown in the accompanying drawings, a casting method for producing a copper-iron bimetallic alloy worm gear comprises the following steps:

[0034] S1. A copper sleeve 10 of prefabricated model DY3236C-02; the inner side of the copper sleeve 10 is an arc surface protruding toward the space where the liquid iron is to be poured. This helps to increase the contact area between the sleeve and the cast iron 20 and improve the structural strength of the mutual melting layer. The copper sleeve 10 is 175 cm high, 465 cm in outer diameter, 350 cm in minimum inner diameter, and 370 cm in maximum inner diameter.

[0035] S2. Prepare the sand box. The sand box has an upper and lower box structure. The bottom of the upper box and the top of the lower box are both provided with an escape space, which extends to the projection surface of the copper sleeve 10 in the plane. The vertical height of the escape space of the upper box is less than the vertical height of the escape space of the lower box. Reducing the escape space in the upper part reduces the cast iron 20 on the top of the copper sleeve 10 and increases the cast iron 20 at the bottom, which helps to balance the temperature field and make the distribution of liquid iron in the cooling space more uniform. The upper escape space is set in the upper box, and the lower escape space is set in the lower box. The diameter of the two escape spaces is 430 cm, the height of the upper escape space is 15 cm, and the height of the lower escape space is 30 cm.

[0036] A bottom core is laid on the inner bottom surface of the lower box body, and a middle hole mud core 30 abutting against the upper box body and the lower box body is also arranged in the sand box.

[0037] The upper box body is also provided with a follow-up ring core which is coaxial with the copper sleeve 10 and constrains the casting of the cast iron 20. The follow-up ring core helps to increase the height of the cast iron 20 above the inner ring of the copper sleeve 10. During the pouring process, the casting time of the cast iron 20 can be appropriately extended to reserve time for the flow of liquid iron, so that the distribution of liquid iron components is more uniform. The height of the follow-up ring core is 180 cm, which is the height of the cast iron 20 after the upper avoidance space is removed after the casting. The inner diameter of the cast iron 20 is 185 cm, the minimum outer diameter is 350 cm, and the maximum outer diameter is 370 cm.

[0038] The ends of the middle hole clay core 30 are chamfered and extend into the upper box and the lower box respectively, so as to improve the stability of the middle hole clay core 30 in the sand box and avoid the factors affecting the molding of the cast iron 20 during the pouring process.

[0039] A sprue 40 is provided on the top surface of the upper box body, and the sprue 40 is connected to the casting inner cavity of the sand box through an entgate 60; four entgates 60 are provided, and the four entgates 60 are connected to the sprue 40 through a cross gate 50, and the cross gate 50 is an arc-shaped structure as a whole.

[0040] S3, pack the copper sleeve 10 into boxes and transfer the copper sleeve 10 between the upper and lower boxes;

[0041] S4, pouring, pouring liquid iron through the sand box sprue 40; the mass ratio of liquid iron to copper sleeve 10 is 3:1, and the liquid iron is 300Kg; according to the heat formula Q=c*m*Δt, the pouring temperature of the liquid iron is controlled, and the temperature of the liquid iron during pouring is 1350°C.

[0042] S5, cooling and molding, after the liquid iron is cooled and molded into cast iron 20, it is taken out from the sand box;

[0043] S6, external shaping, removing and grinding the cast iron 20 parts protruding from the upper and lower end surfaces of the copper sleeve 10;

[0044] Finally, check the joint between the copper sleeve 10 and the cast iron 20 from the end face to see if the joint is complete and smooth.

[0045] The present invention discloses a casting method for producing a copper-iron bimetallic alloy worm gear. The suitable temperature is calculated according to the weight of the poured liquid iron. The avoidance space in the sand box allows the liquid iron to cool here and form a cast iron portion that overlaps with the projections of the upper and lower end surfaces of the copper sleeve, thereby reducing the flow pressure of the liquid iron when passing through the copper sleeve, which is conducive to the formation of an intermetallic layer between the bimetallics. At the same time, it is convenient to provide marks for the subsequent removal and grinding operations. In summary, the method can simplify the process, shorten the cycle, and improve efficiency. The intermetallic layer helps to improve the structural strength of the bimetallic.

[0046] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0047] The terms "upper", "lower", "outer side", "inner side", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish the relative relationship in position if they exist, and do not need to be qualitative. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0048] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A casting method for producing a copper-iron bimetallic alloy worm gear, characterized in that: The following steps are involved: S1, prefabricated copper sleeve (10); S2. Prepare the sand box, which has an upper and lower divided structure; S3, packing the copper sleeve (10) into boxes, and transferring the copper sleeve (10) between the upper and lower boxes; S4, pouring, pouring liquid iron through the sand box sprue (40); S5, cooling and molding, after the liquid iron is cooled and molded into cast iron (20), it is taken out from the sand box; S6, external shaping, removing and grinding the cast iron (20) parts protruding from the upper and lower end surfaces of the copper sleeve (10); Wherein, in step S2, the bottom of the upper box body and the top of the lower box body are both provided with an escape space, and the escape space extends in a plane to the projection surface of the copper sleeve (10); In step S4, the pouring temperature of the liquid iron is controlled according to the heat formula Q=c*m*Δt.

2. A casting method for producing a copper-iron bimetallic alloy worm gear according to claim 1, characterized in that: The vertical height of the escape space of the upper box is smaller than the vertical height of the escape space of the lower box.

3. A casting method for producing a copper-iron bimetallic alloy worm gear according to claim 2, characterized in that: The inner side surface of the copper sleeve (10) is a curved surface that protrudes toward the space where the liquid iron is to be poured.

4. A casting method for producing a copper-iron bimetallic alloy worm gear according to claim 3, characterized in that: The mass ratio of the liquid iron to the copper sleeve (10) is 3:1, and the liquid iron is 300 kg.

5. A casting method for producing a copper-iron bimetallic alloy worm gear according to claim 4, characterized in that: In step S4, the temperature of the liquid iron during pouring is 1300°C to 1400°C.

6. A casting method for producing a copper-iron bimetallic alloy worm gear according to any one of claims 1 to 5, characterized in that: In step S2, a bottom core is laid on the inner bottom surface of the lower box body, and a middle hole mud core (30) is also provided in the sand box to abut against the upper box body and the lower box body.

7. A casting method for producing a copper-iron bimetallic alloy worm gear according to claim 6, characterized in that: In step S2, the interior of the upper box is also provided with a conformable ring core which is coaxial with the copper sleeve (10) and constrains the cast iron (20) to be formed.

8. A casting method for producing a copper-iron bimetallic alloy worm gear according to claim 6, characterized in that: The ends of the middle hole mud core (30) are chamfered and extend into the upper box body and the lower box body respectively.

9. A casting method for producing a copper-iron bimetallic alloy worm gear according to claim 6, characterized in that: A direct pouring gate (40) is provided on the top surface of the upper box body, and the direct pouring gate (40) is connected to the pouring inner cavity of the sand box through an inner pouring gate (60).

10. A casting method for producing a copper-iron bimetallic alloy worm gear according to claim 9, characterized in that: A plurality of the ingates (60) are provided, and the plurality of ingates (60) are connected to the sprue (40) through the runner (50), and the runner (50) is an arc-shaped structure as a whole.

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