A forging method of a wind power hollow main shaft

Abstract

The application provides a forging method for a wind power hollow main shaft, and relates to the field of wind power main shaft forging technology.The method comprises the following steps: based on the model of a wind power hollow main shaft to be forged, a hollow steel ingot mold corresponding to the model is selected and casting is completed to obtain a hollow steel ingot; a forging core rod is inserted into the hollow part of the hollow steel ingot, and the hollow steel ingot is elongated along the forging core rod through free forging; the elongated steel ingot is cut to form a wind power main shaft blank; flange pre-forging is performed on the wind power main shaft blank, so that the wind power main shaft blank is forged with flange ends; the wind power main shaft blank after flange pre-forging is placed into a forging mold, and is taken out from the mold through die forging, so that the forging of the wind power hollow main shaft is completed. By adopting the method, the wind power hollow main shaft is forged through a free combination die forging double composite process, the required steel material is reduced, the number of heating times is reduced, the machining allowance is reduced, the production cost is lower, the forging is fully forged and compacted, and the mechanical properties are better.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wind power main shaft forging technology, in particular to a kind of wind power hollow main shaft's forging method. BACKGROUND

[0002] In today's society, with the increasingly serious global energy shortage and environmental pollution, finding renewable energy has become a major issue facing the world. Compared with other energy sources, wind energy in nature not only has large reserves and wide distribution, but also is inexhaustible. It has the characteristics of fast start, short construction period, less foundation investment than hydropower station construction, strong flexibility, and can effectively curb greenhouse effect and sandstorm disaster, green environmental protection, etc. Therefore, using wind power generation as a new energy development has become an important part of the global future energy development strategy and has been highly valued and strongly supported by all countries. However, due to the fact that the wind field environment is generally in the desert, ocean, valley, and the net point is scattered, it is difficult to manufacture and install, resulting in expensive wind power generation equipment, high cost of wind power generation, and high wind power price than coal power price, thereby restricting the rapid development of wind power.

[0003] The wind power main shaft for MW-level wind turbine equipment of wind power generator is a load-bearing part of wind power equipment, which needs to meet certain use requirements such as load bearing under strong wind energy and zero below forty degrees Celsius environmental temperature. At the same time, there is a contradiction between high power, large size and manufacturing difficulty and installation difficulty.

[0004] At present, manufacturing enterprises usually use casting and free forging process to manufacture wind power main shaft. The difference in quality between casting and forging is obvious. However, they have a common shortcoming that the processing allowance is large, the material utilization rate is low, and the cost is high. This is also a common problem in the industry.

[0005] The above information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, so it can include information that does not constitute prior art known to those skilled in the art. SUMMARY

[0006] The main purpose of the present application is to provide a kind of wind power hollow main shaft's forging method, by free combination die forging double composite process to wind power hollow main shaft forging, improve material utilization rate, reduce fire time, reduce machining time, provide production efficiency, reduce manufacturing cost, while being fully forged and compacted, better mechanical properties.

[0007] In order to solve the foregoing technical problems, the present application provides a kind of wind power hollow main shaft's forging method, comprising the following steps:

[0008] Based on the model of the wind power hollow main shaft to be forged, a corresponding hollow steel ingot mold is selected and casting is completed to obtain a hollow steel ingot.

[0009] inserting a forging mandrel into the hollow of the hollow steel ingot, and elongating the hollow steel ingot along the forging mandrel by free forging;

[0010] cutting the elongated steel ingot to form a wind power main shaft blank;

[0011] pre-forging a flange on the wind power main shaft blank to forge a flange end of the wind power main shaft blank;

[0012] putting the wind power main shaft blank after the flange pre-forging into a forging die, forming the wind power hollow main shaft by die forging and taking it out of the die.

[0013] Optionally, in some embodiments of the present application, before the step of selecting a hollow steel ingot mold corresponding to the model of the wind power hollow main shaft to be forged and completing casting to form the hollow steel ingot based on the model of the wind power hollow main shaft to be forged, the steps include:

[0014] establishing a geometric model of the wind power hollow main shaft to be forged by three-dimensional software based on the model of the wind power hollow main shaft to be forged;

[0015] adding a machining allowance to the geometric model to obtain the volume of the steel ingot required for actual machining;

[0016] selecting a hollow steel ingot mold corresponding to the model according to the volume of the steel ingot required for actual machining.

[0017] Optionally, in some embodiments of the present application, the cutting method of the elongated steel ingot is flame cutting.

[0018] Optionally, in some embodiments of the present application, the step of pre-forging a flange on the wind power main shaft blank to forge a flange end of the wind power main shaft blank includes:

[0019] heating the wind power main shaft blank to 1100-1300℃, and putting the wind power main shaft blank into a flange pre-forging die with an open end;

[0020] installing a flange pre-forging convex anvil in the open end of the flange pre-forging die, and pre-forging a flange on one end of the wind power main shaft blank by spinning generated by rotating the flange pre-forging convex anvil to forge a flange end of the wind power main shaft blank.

[0021] Optionally, in some embodiments of the present application, the opening of the above-mentioned forging die is provided with a flange extrusion flash groove, which is arranged circumferentially along the forging die, and is used in cooperation with the flange pre-forging convex anvil to accelerate the formation of the flange end of the wind power main shaft blank.

[0022] Optionally, in some embodiments of the present application, the step of putting the wind power main shaft blank into the forging die to form the wind power hollow main shaft by die forging includes:

[0023] Put the wind power main shaft blank into the forging die;

[0024] Drive the pressing plate to move, so that the whole wind power main shaft blank is extruded into the inner die;

[0025] Drive the extrusion core rod into the hollow inner hole of the wind power main shaft blank, and force the metal to fill the inside of the forging die through the hole expanding and expanding;

[0026] Demould the wind power main shaft blank to obtain the wind power hollow main shaft.

[0027] Optionally, in some embodiments of the present application, the above-mentioned forging die comprises an outer die body and an inner die body nested in the outer die body;

[0028] The inner die body comprises two inner die half cylinders that are buckled to each other, the two inner die half cylinders are symmetrically arranged, and the inner side wall of the inner die body is provided with a shaping structure;

[0029] The two inner die half cylinders wrap the wind power main shaft blank, and then the two inner die half cylinders together with the wind power main shaft blank are put into the outer die body.

[0030] Optionally, in some embodiments of the present application, the outer side wall of the inner die body is inclinedly arranged, the diameter of the inner die body near the opening end of the outer die body is larger than the diameter of the other end of the inner die body, so as to facilitate the insertion of the inner die body along the inclined wall into the outer die body.

[0031] Optionally, in some embodiments of the present application, the cross section of the shaping structure is a circular ring, and the shaping structure is fixedly arranged along the circumference of the inner die body and used for press forging the shape of the wind power main shaft blank. Optionally, in some embodiments of the present application, the outer die body is provided with a limiting groove, and the inner die body is provided with a limiting baffle matched with the limiting groove, which is used for fixing the inner die body relative to the outer die body. When the inner die body is inserted into the outer die body, the limiting baffle is embedded into the limiting groove after the inner die body moves a certain distance.

[0032] The beneficial effects that can be achieved by the present application.

[0033] The forging method of the wind power hollow main shaft provided by the embodiments of the present application comprises the following steps:

[0034] Based on the model of the wind power hollow main shaft to be forged, a hollow steel ingot mold corresponding to the model is selected and casting is completed to obtain a hollow steel ingot;

[0035] The forging core rod is inserted into the hollow part of the hollow steel ingot, and the hollow steel ingot is directly sleeved with the core rod through free forging to lengthen. Compared with the prior art, the processes of pressing the jaws, cutting the head and tail of the steel ingot, upsetting and punching are reduced, the material consumption is reduced, and the operation process is shortened;

[0036] The steel ingot after drawing is cut to form a wind power main shaft blank, the cutting can remove the metallurgical impurity accumulation area at both ends of the forging blank to ensure the quality of the forging blank body and accurately control the length of the forging blank;

[0037] The flange pre-forging is performed on the wind power main shaft blank to forge the flange end of the wind power main shaft blank; the wind power main shaft blank after the flange pre-forging is placed into a forging die, is taken out from the die through die forging, the die forging of the wind power main shaft blank is completed, and finally the finished product of the wind power hollow main shaft is formed.

[0038] Therefore, it can be seen that the technical scheme of the present application performs forging on the wind power hollow main shaft through the combined process of free forging and die forging, the required steel material is reduced, and the operation process is shortened; and only four heat treatments of free forging, pre-forging and die forging are used, the number of heat treatments is reduced compared with the prior art, and therefore, the overall production cost is lower. BRIEF DESCRIPTION OF DRAWINGS

[0039] Fig. 1 A front view of the wind power hollow main shaft provided for the embodiment of the present application;

[0040] Fig. 2 A sectional view of the wind power hollow main shaft provided for the embodiment of the present application

[0041] Fig. 3 A flowchart of the forging process of the wind power hollow main shaft provided for the embodiment of the present application;

[0042] Fig. 4 A sectional view of the forging die of the wind power hollow main shaft provided for the embodiment of the present application;

[0043] Fig. 5 A structural schematic view of the forging die of the wind power hollow main shaft provided for the embodiment of the present application;

[0044] Fig. 6 A structural schematic view of the forging die of the wind power hollow main shaft provided for the embodiment of the present application, which is installed with a flange pre-forging convex anvil.

[0045] Figure legend: 1-outer die body, 2-inner die half cylinder, 3-flange extrusion flash groove, 4-shaping structure, 5-limiting groove, 6-limiting baffle, 7-flange pre-forging die, 8-flange pre-forging convex anvil, 9-wind power main shaft blank.

[0046] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0047] Clearly, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present application.

[0048] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications will also change accordingly.

[0049] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be internal communication of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0050] In addition, if the present application has descriptions involving "first", "second", etc., the "first", "second", etc. are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features with "first", "second" can explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. For example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of those of ordinary skill in the art, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope of the present application.

[0051] Especially for the wind power hollow main shaft of model: FDZZ-A, referring to Figs. 1-2 In order to overcome the problem that the traditional forging method is prone to defects when the size of the wind power hollow main shaft is increased, and there is more machining allowance and high production cost.

[0052] Referring to Fig. 3The embodiment of the present application provides a forging die and a forging process for a wind power hollow main shaft, and the embodiment of the present application provides a forging method for a wind power hollow main shaft, which is based on the device in the foregoing embodiment and comprises the following steps:

[0053] S1, based on the model of the wind power hollow main shaft to be forged, a hollow steel ingot die corresponding to the model is selected and pouring is completed;

[0054] In the specific implementation process, for the wind power hollow main shaft of different models (for example, FDZZ-A), the steel material with a suitable weight and the steel ingot die with a corresponding shape are selected, then the alloy steel liquid is poured into the steel ingot die, and after cooling, the wind power main shaft blank 9 is formed.

[0055] Taking the wind power hollow main shaft with the model of FDZZ-A as an example, according to GB / T12362-2003 Steel Die Forging Tolerance and Machining Allowance, the die forging extrusion machining allowance is set to 2-5 mm, the three-dimensional simulation volume of the die forging extrusion part is 2.658 cubic meters, the weight is 20.55 tons, the free forging extrusion machining allowance is set to 15-20 mm, the three-dimensional simulation calculation volume of the free forging is 2.955 cubic meters, and the weight is 22.84 tons, and according to the volume obtained by using the three-dimensional simulation of the die forging extrusion, a die with a corresponding volume is selected. Therefore, compared with free forging, the die forging can reduce material consumption and improve material utilization rate under the premise of ensuring the service performance of the product.

[0056] Specifically, the alloy steel liquid is poured into the center pipe to obtain a billet;

[0057] S2, after the hollow steel ingot is taken out, a forging core rod is inserted into the hollow part of the hollow steel ingot, and the hollow steel ingot is elongated along the forging core rod through free forging;

[0058] In the specific implementation process, after the wind power main shaft blank 9 is taken out from the steel ingot die, the wind power main shaft blank 9 is heated to 1200 DEG C after cleaning treatment and then the forging core rod is inserted, and the wind power main shaft blank 9 is forged through the free forging press to elongate the wind power main shaft blank 9 along the forging core rod.

[0059] Compared with the existing traditional forging technology, the processes such as pressing the jaw, cutting the head and tail of the steel ingot, upsetting and punching are omitted, so that the material consumption is further reduced and the operation process is shortened.

[0060] S3, the elongated steel ingot is cut through a cutting device to form the wind power main shaft blank 9;

[0061] After the elongation forging is completed, the wind power main shaft blank 9 is taken out, the forging mandrel is taken off from the wind power main shaft blank 9, and then the cutting device is used to remove the metallurgical impurity accumulation area at both ends of the forged blank to ensure the quality of the forged blank body and accurately control the length of the forged blank, wherein the cutting method can be flame cutting to remove slag and loose enrichment area and ensure the quality of the body.

[0062] Flame cutting is a common way of rough machining of steel plates. Flame cutting, also known as gas cutting, traditionally uses acetylene gas cutting, and later uses propane. Now natural gas cutting has appeared, and because of the characteristics of abundant reserves, low price and no pollution, it has become the first choice for flame cutting. Natural gas flame cutting generally adds natural gas additives to generate a new type of flame cutting gas. Using this gas for flame cutting can make the cutting effect better, improve the cutting efficiency and reduce the cutting cost.

[0063] S4, flange pre-forging is performed on the wind power main shaft blank 9 to make the wind power main shaft blank 9 forge flange ends;

[0064] Referring to Fig. 6 , the blank is heated to 1200℃, the wind power main shaft blank 9 is placed in the flange pre-forging die, the flange pre-forging convex anvil 8 is arranged on the top of the wind power main shaft blank 9, the flange pre-forging convex anvil 8 is inserted into the inner hole of the wind power main shaft blank 9, and in use, the flange pre-forging convex anvil 8 is driven to rotate along the axial direction of the inner hole of the wind power main shaft blank 9 by a motor, so as to realize the control of the movement of the top part of the wind power main shaft blank 9 to the four directions, and the flange pre-forging convex anvil 8 is embedded into the flange pre-forging die as much as possible, so as to form the flange part of the wind power main shaft blank 9 and effectively ensure the roundness and thickness of the flange blank.

[0065] The flange pre-forging anvil includes a pressing block and a connecting shaft, and the connecting shaft is arranged towards the flange pre-forging die. In use, the flange pre-forging die is driven to rotate by a rotating motor, so as to spin the wind power main shaft blank 9 until the pressing block abuts against the flange pre-forging die and the connecting shaft is completely inserted into the inner hole of the wind power main shaft blank 9. At this time, the wind power main shaft blank 9 completes the flange pre-forging.

[0066] Optionally, the outer part of the pressing block near the connecting shaft side of the embodiment is convex, and the inner part of the pressing block near the connecting shaft side is concave. When the pressing block abuts against the flange pre-forging die, the wind power main shaft blank 9 has a certain excess material to prevent the wind power main shaft blank 9 from not having enough material due to the existence of gaps or cracks during the flange pre-forging process.

[0067] S5, the wind power main shaft blank 9 is placed in the forging die to form the wind power hollow main shaft by die forging;

[0068] After the flange pre-forging of the wind power main shaft blank 9 is completed, the work platform controls the wind power main shaft blank 9 to be inserted into the inner mold, and the center of the wind power main shaft blank 9 is coaxial with the center of the press.

[0069] The first hydraulic cylinder provided on the work platform drives the pressing plate to press (level) the flange structure of the wind power main shaft blank 9, and the entire wind power main shaft blank 9 is forced to be extruded into the inner mold until the flange structure of the wind power main shaft blank 9 is flush with the mold, and then the second hydraulic cylinder drives the extrusion core rod to enter the hollow inner hole of the wind power main shaft blank 9 and pass through the inner hole of the entire wind power main shaft blank 9, the diameter of the extrusion core rod is greater than the inner diameter of the inner hole of the wind power main shaft blank 9, so that the metal can be forced to fill each part on the inner side of the inner mold, after 4-6 seconds of pressure maintaining, the extrusion core rod is extracted, and the wind power main shaft blank 9 is removed from the work platform for demolding operation, and the forging process of the wind power hollow main shaft is completed after cooling.

[0070] Compared with the large wind power hollow main shaft produced by the traditional free forging, the forging method of the structural free forging combined with the die forging composite forming needs to reduce the steel material, the fire times, the machining allowance, and the production cost is lower, and the metal flow line of the composite forming product is more complete, compared with the two stress points of the traditional free forging, the steel material can be more fully forged and compacted through the three-way stress, and the mechanical property is better.

[0071] Optionally, referring to Figs. 4-5 The forging die of the embodiment includes an outer mold body 1 and an inner mold body nested in the outer mold body 1, the inner mold body includes two inner mold half cylinders 2 that are buckled to each other, the two inner mold half cylinders 2 are symmetrically arranged, and the inner side wall of the inner mold body is provided with a shaping structure 4.

[0072] The outer mold body 1 is provided with a cylindrical groove, the inner mold body formed by the two inner mold half cylinders 2 that are buckled to each other can be exactly put into the groove, and the shaping structure 4 of the inner side wall of the inner mold body corresponds to the shape of the outer side wall of the wind power hollow main shaft of model FDZZ-A. Thus, the wind power main shaft blank can be subjected to three-way stress through closed die forging, the stress is uniform, and the probability of cracks in the production of the wind power hollow main shaft is reduced.

[0073] Specific use mode is: the wind power main shaft blank formed after the four steps of casting hollow steel ingot, forging core rod elongation, flame cleaning and flange pre-forging is put into the through hole in the middle of the inner mold body, the core rod is coaxially arranged with the inner mold body at this time, the wind power main shaft blank is extruded by the outer mold body 1 and the inner mold body, then the core rod is removed and demolding treatment is performed, and finally the production of the wind power hollow main shaft is completed.

[0074] The demolding treatment is to separate the outer mold body 1 and the inner mold body by rotating the outer mold body 1 or pulling the inner mold body, so that the two inner mold half cylinders 2 can be separated naturally after the outer mold body 1 loses the restriction on the two inner mold half cylinders 2, thereby facilitating demolding.

[0075] The shaping structure 4 is arranged to make the shape of the wind power main shaft blank before the compression molding treatment as close as possible to the shape of the wind power hollow main shaft of the FDZZ-A type, thereby effectively reducing the energy and labor loss in the compression molding treatment.

[0076] Optionally, the inner membrane cylinder outer side wall is inclined, the diameter of the inner mold body close to the opening end of the outer mold body 1 is larger than the diameter of the other end of the inner mold body, so that the outer mold body 1 is rotated to make the groove opening direction of the outer mold body 1 downward, and the inner mold body is slid out of the outer mold body 1.

[0077] As an optional embodiment, the outer structure of the wind power hollow main shaft of the FDZZ-A type is that the outer side wall of the shaft body is provided with a groove in the middle part, and the cross section of the shaping structure 4 is a circular ring, and the shaping structure 4 is fixedly arranged along the circumference of the inner mold body, thereby facilitating the forging of the outer side wall of the shaft body provided with the groove.

[0078] The opening of the outer mold body 1 is provided with a flange extrusion flash groove 3, and the flange extrusion flash groove 3 is arranged along the circumference of the inner membrane cylinder. The flange extrusion flash groove 3 is arranged to place the flange structure formed in the pre-forging process, and to perform secondary forging on the flange structure.

[0079] The outer mold body 1 is provided with a limiting groove 5, and the inner membrane cylinder is provided with a limiting baffle 6 matched with the limiting groove 5, so that the inner membrane cylinder can be taken out better after forging, the depth of the limiting groove 5 is the same as the height of the limiting baffle 6, and the limiting groove 5 can be arranged at the bottom of the flange extrusion flash groove 3, thereby optimizing the structure and preventing the influence of the connection between the inner mold body and the outer mold body 1 on the flange structure of the wind power hollow main shaft during forging.

[0080] The edges and corners of the shaping structure 4 are smooth, facilitating the flow of metal, and the edges and corners of the flange extrusion flash groove 3, the limiting groove 5 and the limiting baffle 6 are also smooth structures. In actual operation, lubricant is needed between the inner membrane cylinder and the outer mold body 1, between the inner membrane cylinder and the wind power main shaft blank 9, and between the wind power main shaft blank 9 and the core rod.

[0081] The above is only a preferred embodiment of the present application and is not intended to limit the present application. It is obvious for those skilled in the art that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or essential characteristics of the present application.

Claims

1. A forging method of a wind power hollow main shaft, characterized in that, The method comprises the following steps: Based on the model of the wind power hollow main shaft to be forged, a hollow steel ingot mold corresponding to the model is selected and casting is completed to obtain a hollow steel ingot; A forging core rod is inserted into the hollow of the hollow steel ingot, and the hollow steel ingot is elongated along the forging core rod by free forging; The elongated steel ingot is cut to form a wind power main shaft blank; The wind power main shaft blank is pre-forged to form a flange end of the wind power main shaft blank; The wind power main shaft blank after flange pre-forging is placed into a forging mold, and the wind power hollow main shaft is obtained after the wind power main shaft blank is taken out from the mold.

2. The windmill hollow spindle forging method according to claim 1, wherein The step before the hollow steel ingot mold corresponding to the model is selected and the hollow steel ingot is formed based on the model of the wind power hollow main shaft to be forged, comprising: Based on the model of the wind power hollow main shaft to be forged, a geometric model of the wind power hollow main shaft to be forged is established by using a three-dimensional software; The machining allowance added to the geometric model is obtained to obtain the actual steel ingot volume required for machining; According to the actual steel ingot volume required for machining, a hollow steel ingot mold corresponding to the model is selected.

3. The windmill hollow spindle forging method according to claim 1, wherein The cutting method of the elongated steel ingot is flame cutting.

4. The windmill hollow spindle forging method according to claim 1, wherein The step of pre-forging the flange of the wind power main shaft blank to forge a flange end of the wind power main shaft blank, comprising: The wind power main shaft blank is heated to 1100-1300 DEG C, and the wind power main shaft blank is placed into a flange pre-forging mold with an open end; The flange pre-forging convex anvil is placed at the open end of the flange pre-forging mold, and the flange of the wind power main shaft blank is pre-forged by the spinning generated by rotating the flange pre-forging convex anvil to make the wind power main shaft blank forge a flange end.

5. The windmill hollow spindle forging method according to claim 4, characterized by: The opening of the forging mold is provided with a flange extrusion flash groove, and the flange extrusion flash groove is arranged circumferentially along the forging mold; The step of pre-forging the flange of the wind power main shaft blank to forge a flange end of the wind power main shaft blank, comprising: After the wind power main shaft blank is placed into the flange pre-forging mold with an open end, the wind power main shaft blank extends out of the flange pre-forging mold at one end; The part of the wind power main shaft blank extending out of the flange pre-forging mold is pressed into the flange extrusion flash groove by spinning the flange pre-forging convex anvil, and the forging of the flange end of the wind power main shaft blank is completed.

6. The windmill hollow spindle forging method according to claim 5, wherein The step of placing the wind power main shaft blank into the forging mold to form the wind power hollow main shaft by die forging, comprising: The wind power main shaft blank is placed into the forging mold; The press plate is driven to move, so that the wind power main shaft blank is completely extruded into the inner mold; The extrusion core rod is driven to enter the hollow inner hole of the wind power main shaft blank, and the metal is forced to fill the inside of the forging mold by hole expanding and expanding; The wind power main shaft blank is demolded to obtain the wind power hollow main shaft.

7. The windmill hollow spindle forging method according to claim 6, characterized by: The forging mold comprises an outer mold body and an inner mold body nested in the outer mold body; the inner mold body comprises two inner mold half cylinders which are buckled to each other, the two inner mold half cylinders are symmetrically arranged, and the inner side wall of the inner mold body is provided with a shaping structure; the step of placing the wind power main shaft blank into the forging mold, comprising: The two inner mold half cylinders are buckled to each other, and a cylindrical recess is formed between the two inner mold half cylinders; The two inner mold half cylinders are placed into the outer mold body; The wind power main shaft blank is placed into the recess and is extruded and shaped by the shaping structure.

8. The windmill hollow spindle forging method according to claim 7, characterized by: The inner mold body outer lateral wall is obliquely arranged, and the diameter of the inner mold body near the opening end of the outer mold body is larger than the diameter of the other end of the inner mold body, facilitating the insertion of the inner mold body along the oblique wall into the outer mold body.

9. The windmill hollow spindle forging method according to claim 7, wherein: The shaping structure is circular in cross section and is fixedly arranged along the circumference of the inner mold body to press forge the shape of the wind power main shaft blank.

10. The windmill hollow spindle forging method according to claim 7, wherein: The outer mold body is provided with a limiting groove, and the inner mold body is provided with a limiting baffle matched with the limiting groove, and the step of putting the two inner mold half cylinders into the outer mold body comprises: Inserting the inner mold body into the outer mold body, and when the inner mold body is fully inserted into the outer mold body, the limiting baffle is embedded in the limiting groove.

Images