A cooling tool for the bore of a hollow main shaft forging and method of use

Abstract

The application provides a cooling tool for the inner hole of a hollow main shaft forging and a use method, and mainly relates to the field of inner hole cooling tools and inner hole cooling technologies during performance heat treatment of a hollow main shaft. The cooling device comprises a driving part, a connecting pipe, a pipe body, a supporting part, a stop part and a branch pipe. The use method comprises inserting the cooling tool into the inner hole of the main shaft during single-liquid and multi-liquid cooling of the hollow main shaft, adjusting the flow rate of the inner hole cooling medium by controlling the gear position of the driving part, controlling the convection speed of the cooling medium in the inner hole of the main shaft, making the cooling medium in the inner hole of the main shaft sufficiently supplemented, breaking the steam film, avoiding the expansion of the dissolved gas in the cooling medium after vaporization, thereby improving the cooling quality of the inner hole of the main shaft and avoiding cracks. The application has the advantages of low manufacturing cost, relatively simple structure, strong interchangeability, very wide use range, convenient operation and carrying, and can be used in different cooling media and can be used for single-liquid or multi-liquid cooling of hollow main shafts with different inner hole diameters.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of inner hole cooling of forgings, in particular to a cooling tool for the inner hole of a hollow type main shaft forging and a use method thereof. BACKGROUND

[0002] In order to save energy and production cost, and with the progress of production technology, part of the finished product wind power main shaft with a center hole is changed from solid performance heat treatment to hollow performance heat treatment. Due to the design shape and large tonnage of the main shaft, the cooling method generally adopts liquid immersion cooling. However, this method has the following problems: 1. There is a difference in cooling speed between the outer surface and the inner hole of the hollow main shaft. The outer surface of the hollow main shaft cools quickly, while the inner hole cools slowly due to the slow flow speed of the cooling medium, which easily produces a large thermal stress difference between the outer and inner parts, thereby causing cracks; 2. During initial cooling, the inner hole of the hollow main shaft cannot break the steam film due to insufficient supply of cooling medium, which seriously affects the overall cooling effect and easily leads to uneven performance of the inner wall; 3. The dissolved gas in the cooling medium will expand after vaporization and be discharged to release pressure along the inner hole, affecting the convection of the inner hole cooling medium.

[0003] The material of the wind power main shaft is generally 42CrMo or 34CrNiMo6. During performance heat treatment, the material undergoes phase change from A (austenite) to M (martensite), and the M (martensite) has the characteristics of being hard and brittle, with almost zero toughness. Therefore, it is necessary to minimize the generation of internal stress, including thermal stress and organizational stress, during quenching and tempering. In actual production, the above three situations exist, which causes uneven cooling of the inner hole, thereby causing uneven internal stress and easily producing cracks and other irreparable defects in the low temperature zone. The cooling effect and quality of the inner hole directly affect the service life of the finished main shaft. Therefore, the problem of inner hole cooling needs to be solved. SUMMARY

[0004] In view of the above shortcomings of the prior art, the present application provides a cooling tool for the inner hole of a hollow type main shaft forging and a use method thereof to improve the cooling effect of the inner hole of the forging.

[0005] To achieve the above object and other related objects, the present application provides a cooling tool for the inner hole of a hollow type main shaft forging, comprising: a driving part, a connecting pipe, a pipe body and a branch pipe.

[0006] One end of the connecting pipe is connected to the driving part; the pipe body is connected and arranged at the other end of the connecting pipe; the pipe body is provided with a supporting part and a stop part; and the branch pipe is fixedly arranged on the pipe body.

[0007] In an example of the present application, the two ends of the connecting pipe are respectively connected to the driving part and the pipe body, and the connecting pipe can adjust the angle.

[0008] In an example of the present application, the pipe body is a steel pipe, the outer diameter of the pipe body is 100-150mm, the inner diameter of the pipe body is 20-30mm smaller than the outer diameter of the pipe body, and the length of the pipe body is longer than the length of the forging.

[0009] In an example of the present application, the stopper is in the shape of a straight line and is fixedly arranged on the pipe body; the diameter of the circumscribed circle of the stopper is 100-200mm larger than the inner diameter of the forging.

[0010] In an example of the present application, the support is fixedly arranged on the pipe body.

[0011] In an example of the present application, the support is a cross-shaped support frame, and the diameter of the circumscribed circle of the cross-shaped support frame is 50-100mm smaller than the inner diameter of the forging.

[0012] In an example of the present application, the branch pipe is fixedly arranged on the pipe body, the hollow pipe of the branch pipe is communicated with the hollow pipe of the pipe body, and the branch pipe is arranged in a spiral and progressive manner on the pipe body.

[0013] In an example of the present application, the branch pipe is divided into two segments, the included angle between the two segments is 135°, a part of the branch pipe is fixedly connected to the pipe body at an angle of 45°, and the other part of the branch pipe is parallel to the pipe body and extends away from the connecting pipe.

[0014] The present application also provides a use method of the hollow main shaft forging inner hole cooling tool, comprising:

[0015] Inserting the cooling tool involved in any of the above into the inner hole of the forging, immersing the forging into the cooling medium, adjusting the flow rate of the cooling medium in the inner hole of the forging according to the cooling process, and taking out the forging and pulling out the cooling tool after the cooling is completed.

[0016] In an example of the present application, the flow rate of the cooling medium in the inner hole of the forging is adjusted according to the cooling process, comprising:

[0017] When the forging is immersed into the cooling medium, the flow rate is V, V=(S1 / S2)×V1, S1 is the total outer circular surface area of the forging, S2 is the total inner hole surface area of the forging, and V1 is the flow rate of the cooling medium on the outer surface of the forging.

[0018] When the forging is cooled to 300-350℃, the flow rate is V1, and V1 is the flow rate of the cooling medium on the outer surface of the forging.

[0019] The present application has the following advantages by adopting the above structure:

[0020] 1. The manufacturing cost is relatively low, the structure is relatively simple, the interchangeability is relatively strong, the use range is very wide, the operation is convenient, and the tool can be used in different cooling media and can be used for single-liquid or multi-liquid cooling of hollow main shaft forgings with different inner hole diameters.

[0021] 2. According to the forging cooling temperature, the inner hole medium flow rate is adjusted, the generation of internal stress is reduced under the premise of ensuring the quenching effect, the generation of defects such as cracks is prevented, and the product quality is ensured. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0023] Figure 1 The cooling tool schematic diagram of an embodiment of the present application.

[0024] Element number explanation

[0025] 100, driving part; 200, connecting pipe; 300, pipe body; 400, branch pipe; 500, supporting part; 600, stop part. DETAILED DESCRIPTION

[0026] The embodiments of the present application will be described below through specific concrete examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the present description. The present application can also be implemented or applied through other different specific embodiments, and each detail in the present description can be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present application are for describing specific specific embodiments, and are not intended to limit the protection scope of the present application. The test methods in the following embodiments are not specified, and are usually performed according to conventional conditions or according to the conditions recommended by each manufacturer.

[0027] When the embodiments give a numerical range, it should be understood that, unless otherwise specified by the present application, each numerical range and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present application are consistent with the mastery of the prior art by those skilled in the art and the description of the present application, and any method, equipment and material of the prior art similar or equivalent to the method, equipment and material described in the embodiments of the present application can also be used to realize the present application.

[0028] It is to be understood that the terms such as "upper", "lower", "left", "right", "intermediate", and "one" cited in the present specification are only for the convenience of clear description, and are not intended to limit the scope of the present application, and the change or adjustment of the relative relationship is also regarded as the scope of the present application without substantial change of the technical content.

[0029] Please refer to Figure 1 A cooling tool for the inner hole of a hollow main shaft forging, comprising a driving part 100, a connecting pipe 200, a pipe body 300 and a branch pipe 400.

[0030] One end of the connecting pipe 200 is connected to the driving part 100; the pipe body 300 is connected to the other end of the connecting pipe 200; the pipe body 300 is provided with a support part 500 and a stop part 600; the branch pipe 400 is fixedly arranged on the pipe body 300. The driving part 100 can suck in the cooling medium through the pipeline.

[0031] In an embodiment of the present application, the two ends of the connecting pipe 200 are connected to the driving part 100 and the pipe body 300 respectively, and the connecting pipe 200 can adjust the angle to facilitate the plugging operation during use. Using a material with moderate hardness for the connecting pipe 200 can make the connecting pipe 200 adjust the angle direction, bend, etc., so as to facilitate the operation, disassembly and assembly of the cooling tool.

[0032] In an embodiment of the present application, the pipe body 300 is a steel pipe, the outer diameter of the pipe body 300 is 100-150mm, the inner diameter of the pipe body 300 is 20-30mm smaller than the outer diameter of the pipe body 300, and the length of the pipe body 300 is longer than the length of the forging. According to the size of the inner diameter of the forging to be cooled, the specific size of the pipe body 300 is selected, so that the cooling tool can be inserted into the inner hole of the forging.

[0033] In an embodiment of the present application, the stop part 600 is a one-character structure, and the stop part 600 is fixedly arranged on the pipe body 300; the stop part 600 is greater than the inner diameter of the forging by 100-200mm, and the positioning of the pipe body 300 in the inner hole of the forging can be realized. For example, a plurality of steel bars can be vertically welded on the pipe body 300 as the stop part 600, and the length of the steel bars is greater than the diameter of the forging by 100-200mm. The position of the stop part 600 on the pipe body 300 is determined according to the actual use requirement and the length of the forging.

[0034] In an embodiment of the present application, the support part 500 is fixedly arranged on the pipe body 300, the support part 500 is a cross-shaped support frame, and the diameter of the circumscribed circle of the cross-shaped support frame is 50-100mm smaller than the inner diameter of the forging. For example, four same steel bars can be used to be welded into a cross-shaped frame at a position of the pipe body 300, as the support part 500. The support part 500 can ensure that the cooling tool does not deviate to one side after being inserted into the inner hole of the forging, thereby affecting the cooling effect. The spacing between the support parts 500 is determined according to actual use requirements and the length of the forging.

[0035] In an embodiment of the present application, the branch pipe 400 is fixedly arranged on the pipe body 300, the hollow pipe of the branch pipe 400 is communicated with the hollow pipe of the pipe body 300, and the branch pipe 400 is arranged in a spiral and progressive manner on the pipe body 300. The branch pipe 400 is divided into two sections, and the included angle between the two sections is 135°. A part of the branch pipe 400 is fixedly connected to the pipe body 300 at an angle of 45°, and the other part of the branch pipe 400 is parallel to the pipe body 300, and the branch pipe 400 extends in a direction away from the connecting pipe 200. The distribution of the branch pipe 400 on the pipe body 300 can ensure that the flow rate of the cooling medium in the inner hole of the forging is uniform during the cooling of the forging, thereby improving the cooling quality. The spacing between the branch pipes 400 is determined according to actual use requirements.

[0036] In an embodiment of the present application, the motor pump is used as the driving part 100, the connecting pipe 200 is selected to be a hard plastic pipe, the hard plastic pipe has moderate hardness, and will not be too hard to cause the inability to bend and adjust the angle and the curvature, and will not be too soft to cause the knot to affect the flow. As a preferred, a steel pipe with an outer diameter of 100mm and an inner diameter of 80mm is used as the pipe body 300, and the length of the pipe body 300 is selected according to the length of the forging. The connecting pipe 200 connects the driving part 100 and the pipe body 300. The stop part 600 is made of an iron rod, and is fixed near the connection between the connecting pipe 200 and the pipe body 300, and the specific position is determined according to specific needs. The length of the iron rod is greater than the inner diameter of the forging, the stop part 600 can be clamped outside the inner diameter of the forging, and the position of the pipe body 300 in the length direction at the inner diameter of the forging is positioned. The branch pipe 400 is made of a hollow small steel pipe, the branch pipes 400 are spaced 200mm apart and arranged in a spiral and progressive manner, the support part 500 is a cross-shaped support frame, the outer circle of the cross-shaped support frame is 50mm smaller than the inner diameter of the forging, so that the cooling tool does not deviate to one side when being inserted into the inner part of the forging, and the cross-shaped support frames are spaced 800mm apart.

[0037] In an embodiment of the present application, the present application also provides a use method of the hollow main shaft forging inner hole cooling tool, which comprises the following steps: inserting the cooling tool involved in any one of the above into the inner hole of the forging, immersing the forging into the cooling medium, and immersing part of the cooling tool into the cooling medium; adjusting the flow rate of the cooling medium in the inner hole of the forging according to the cooling process; after the cooling is completed, taking out the forging and pulling out the cooling tool.

[0038] In one embodiment of the present application, the flow rate of the cooling medium in the inner hole of the forging is adjusted according to the cooling process, including: when the forging is immersed in the cooling medium, the flow rate is V, V=(S1 / S2) x V1, wherein / represents division, x represents multiplication, S1 is the total surface area of the outer circle of the forging, S2 is the total surface area of the inner hole of the forging, and V1 is the flow rate of the cooling medium on the outer surface of the forging; when the forging is cooled to 300-350°C, the flow rate is V1, and V1 is the flow rate of the cooling medium on the outer surface of the forging.

[0039] In one embodiment of the present application, when single-liquid cooling is used, the hollow main shaft forging after austenitizing and before performance heat treatment is hoisted out of the heating furnace to above the cooling medium, and then the cooling tool is inserted into the inner hole of the forging until the stop portion 600 contacts the outer end surface of the forging. Then the forging and the cooling tool are immersed in the cooling medium, and during the immersion process, when the inner hole is just fully immersed, the motor pump of the driving portion 100 is opened to drive the cooling medium to flow out of the cooling tool, and the flow rate is set to V, V=(S1 / S2) x V1, wherein S1 is the total surface area of the outer circle of the forging, S2 is the total surface area of the inner hole of the forging, and V1 is the flow rate of the cooling medium on the outer surface of the forging. When the forging is cooled to 300-350°C, the flow rate of the cooling medium in the inner hole is adjusted to V1 by adjusting the gear of the driving portion 100 until the cooling is completed. Finally, the main shaft forging and the cooling tool are hoisted out of the cooling medium, and when the inner hole leaves the cooling medium, the driving portion 100 is closed and the cooling tool is pulled out.

[0040] In one embodiment of the present application, when using double liquid cooling, the hollow spindle-like forged piece after austenitizing is hoisted out of the heating furnace to above the first cooling medium, and then the cooling tool is inserted into the inner hole of the forged piece until the stopper 600 contacts the outer end surface of the forged piece. Then the forged piece and the cooling tool are immersed into the first cooling medium, and when the inner hole is just fully immersed, the motor pump of the driving part 100 is opened to drive the first cooling medium to flow out of the cooling tool at a flow rate of V, where V=(S1 / S2)×V1, S1 is the total outer circular surface area of the forged piece, S2 is the total inner hole surface area of the forged piece, and V1 is the first cooling medium flow rate of the outer surface of the forged piece. After cooling in the first cooling medium according to the process requirements, the forged piece is hoisted out, and when the inner hole just comes out of the first cooling medium, the driving part 100 is closed, and the cooling tool is pulled out. Then the forged piece is hoisted to above the second cooling medium, and another cooling tool is inserted into the forged piece until the stopper 600 contacts the outer end of the forged piece. Then the forged piece and the cooling tool are immersed into the second cooling medium, and when the inner hole is just fully immersed, the motor pump of the driving part 100 is opened to drive the second cooling medium to flow out of the cooling tool at a flow rate of V, where V=(S1 / S2)×V1, S1 is the total outer circular surface area of the forged piece, S2 is the total inner hole surface area of the forged piece, and V1 is the second cooling medium flow rate of the outer surface of the forged piece. When the forged piece is cooled to the process required temperature, the inner hole second cooling medium flow rate is adjusted to V1 by adjusting the gear of the driving part 100 until the cooling is completed. Finally, the spindle forged piece and the cooling tool are hoisted out of the cooling medium, and when the inner hole leaves the second cooling medium, the driving part 100 is closed, and the cooling tool is pulled out.

[0041] The present application is a cooling tool for the inner hole of a hollow spindle-like forged piece and a method of use. The cooling tool is used to spray a high-speed cooling medium into the inner hole of a hollow spindle-like forged piece, which is beneficial to increase the convection speed of the inner wall and the cooling medium, break the vapor film, speed up heat exchange, ensure the performance of the forged piece, and improve the overall quality of the hollow spindle-like forged piece. The cooling tool has a low manufacturing cost, a relatively simple structure, strong interchangeability, a very wide range of use, is easy to operate and carry, can be used in different cooling media, and can be used for single-liquid or multi-liquid cooling of hollow spindle-like forged pieces with different inner hole diameters. Therefore, the present application effectively overcomes some practical problems in the prior art and has high utilization value and use significance. Finally, it should be noted that the above embodiments are only illustrative of the principles and effects of the present application and are not intended to limit the present application; anyone skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application; therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical concept of the present application should be covered by the claims of the present application.

Claims

1. A cooling tool for the bore of a hollow main shaft-like forging, characterized in that It comprises: a driving part; a connecting pipe, one end of which is connected to the driving part; a pipe body, which is connected to the other end of the connecting pipe; the pipe body is provided with a supporting part and a stop part; a branch pipe, which is fixedly arranged on the pipe body; the hollow pipe of the branch pipe is communicated with the hollow pipe of the pipe body, and the branch pipe is arranged in a spiral and progressive manner on the pipe body; the branch pipe is divided into two sections, and the included angle between the two sections is 135°; a part of the branch pipe is fixedly connected to the pipe body at an angle of 45°, and the other part of the branch pipe is parallel to the pipe body, and the branch pipe extends in a direction away from the connecting pipe.

2. The cooled tool of claim 1, wherein, The two ends of the connecting pipe are connected to the driving part and the pipe body respectively, and the connecting pipe can adjust the angle.

3. The cooled tool of claim 1, wherein, The pipe body is a steel pipe, the outer diameter of the pipe body is 100-150 mm, the inner diameter of the pipe body is 20-30 mm smaller than the outer diameter of the pipe body, and the length of the pipe body is longer than the length of the forging.

4. The cooled tool of claim 1, wherein, The stop part is a one-letter structure and is fixedly arranged on the pipe body; the diameter of the circumscribed circle of the stop part is 100-200 mm larger than the inner diameter of the forging.

5. The cooled tool of claim 1, wherein, The supporting part is fixedly arranged on the pipe body.

6. The cooled tool of claim 1, wherein The supporting part is a cross-shaped supporting frame, and the diameter of the circumscribed circle of the cross-shaped supporting frame is 50-100 mm smaller than the inner diameter of the forging.

7. A method of using a hollow mandrel forging inner bore cooling tool, characterized by, It comprises: inserting the cooling tool involved in any one of claims 1-6 into the inner hole of the forging, and immersing the forging into a cooling medium; adjusting the flow rate of the cooling medium in the inner hole of the forging according to the cooling process; after cooling, taking out the forging and pulling out the cooling tool.

8. The method of use of claim 7, wherein, Adjusting the flow rate of the cooling medium in the inner hole of the forging according to the cooling process comprises: when the forging is immersed in the cooling medium, the flow rate is V, V=(S1 / S2)×V1, S1 is the total surface area of the outer circle of the forging, S2 is the total surface area of the inner hole of the forging, and V1 is the flow rate of the cooling medium on the outer surface of the forging; when the forging is cooled to 300-350℃, the flow rate is V1, and V1 is the flow rate of the cooling medium on the outer surface of the forging.

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