阅读说明：本技术 风电用变桨输出轴锻件的加工工艺 (Machining process of variable-pitch output shaft forging for wind power ) 是由 沈杰 汤扬 刘晓 于 2021-06-30 设计创作，主要内容包括：本发明涉及一种风电用变桨输出轴锻件的加工工艺,包括原材料入场检验—下料锻造—车削—热处理—磨削—探伤—装前终检—装配—装后检查—包装入库,下料锻造工序中,等体积下料装置包括两个相互垂直的光透过型测量传感器,取两个传感器测量平均值作为测量结果；磨削工序包括粗磨—一次附加回火—细磨—二次附加回火—终磨；磨削工序中,工件表面的波纹进行了理论分析。本发明下料锻造工序中,采用等体积下料装置,保证锻件尺寸精度；满足了工艺要求,磨削时,控制工件转速n1与砂轮转速n2之比为无限不循环小数,完成对磨加工对工件波纹度控制。(The invention relates to a processing technology of a variable-pitch output shaft forged piece for wind power, which comprises the steps of raw material incoming inspection, blanking forging, turning, heat treatment, grinding, flaw detection, final inspection before loading, assembly, inspection after loading, packaging and warehousing, wherein in the blanking forging process, an equal-volume blanking device comprises two mutually-perpendicular light transmission type measuring sensors, and the average value of the measurements of the two sensors is taken as a measurement result; the grinding procedure comprises coarse grinding, primary additional tempering, fine grinding, secondary additional tempering and final grinding; in the grinding process, the waviness of the surface of the workpiece is theoretically analyzed. In the blanking forging process, an isometric blanking device is adopted to ensure the dimensional accuracy of the forge piece; the process requirements are met, during grinding, the ratio of the workpiece rotating speed n1 to the grinding wheel rotating speed n2 is controlled to be infinite non-circulating decimal, and the waviness of the workpiece is controlled by grinding.)

1. The machining process of the variable-pitch output shaft forging for wind power is characterized by comprising the following steps of: the method comprises the following process steps: raw material entering inspection, blanking forging, turning, heat treatment, grinding, flaw detection, final inspection before loading, assembly, inspection after loading, packaging and warehousing;

in the blanking forging procedure, an isometric blanking device is adopted; the equal-volume blanking device comprises two mutually perpendicular light transmission type measuring sensors, and the average value of the measurements of the two sensors is taken as a measurement result; the instantaneously measured volume Δ V is as follows:

ΔV=（π×Δd²×Δh）/4

in the formula, delta d is the average diameter of the bar stock measured instantly, and delta h is the distance between the bar stocks conveyed by a servo motor controlled by an encoder;

the expected blanking volume V is as follows:

V=∑n i=1（π×d_i ²×h_i）/4

in the formula (d)_iIs the measured instantaneous diameter;

h_ia single step feed length;

the grinding procedure comprises coarse grinding, primary additional tempering, fine grinding, secondary additional tempering and final grinding;

in the grinding step, the rotational speed of the grinding wheel is n1, the rotational speed of the workpiece is n2, and when the workpiece rotates for the second round in the finish grinding, the ratio of the rotational speed n1 of the grinding wheel to the rotational speed n2 of the workpiece is infinite acyclic decimal, and the phase shift is phi =90 °.

2. The machining process of the wind power variable pitch output shaft forging piece according to claim 1, characterized in that: the heat treatment process comprises normalizing, annealing and quenching;

in the normalizing procedure, a spray cooling device is arranged for each forged piece to be cooled after forging.

3. The machining process of the wind power variable pitch output shaft forging piece according to claim 1, characterized in that: when the grinding wheel rotates at n1, a vibration displacement X = Asin (ω τ) occurs in the horizontal direction due to problems such as grinding wheel balance.

4. The machining process of the wind power variable pitch output shaft forging piece according to claim 2, characterized in that: the annealing temperature is maintained at 780-800 ℃, the heat preservation time is not less than 4 hours, and then the product is naturally cooled.

5. The machining process of the wind power variable pitch output shaft forging piece according to claim 2, characterized in that: the quenching heating adopts a rotary hearth type protective atmosphere quenching furnace.

Technical Field

The invention relates to a machining process of a variable-pitch output shaft forging for wind power. Belongs to the technical field of mechanical equipment.

Background

Wind power generation refers to converting kinetic energy of wind into electric energy. Wind energy is a clean and pollution-free renewable energy source, is very environment-friendly by utilizing wind power for power generation, and has huge wind energy content, so that the wind energy is increasingly paid attention by various countries in the world.

The principle of wind power generation is that wind power drives windmill blades to rotate, and then the rotating speed is increased through a speed increaser, so that a generator is promoted to generate electricity.

The variable pitch system is one of the core parts of a large-scale wind turbine control system, and plays an important role in safe, stable and efficient operation of the wind turbine.

The pitch control technology is simply that the attack angle of airflow to the blades is changed by adjusting the pitch angle of the blades, and then the aerodynamic torque and the aerodynamic power captured by the wind wheel are controlled.

The size precision of the existing variable-pitch output shaft forged piece for wind power is poor; the grinding process can not meet the process requirements and can not well control the waviness of the workpiece.

Disclosure of Invention

The invention aims to overcome the defects and provides a machining process of a variable-pitch output shaft forging for wind power.

The purpose of the invention is realized as follows:

a machining process of a variable-pitch output shaft forging for wind power is characterized by comprising the following steps: the method comprises the following process steps: raw material entering inspection, blanking forging, turning, heat treatment, grinding, flaw detection, final inspection before loading, assembly, inspection after loading, packaging and warehousing;

in the blanking forging procedure, an isometric blanking device is adopted; the equal-volume blanking device comprises two mutually perpendicular light transmission type measuring sensors, and the average value of the measurements of the two sensors is taken as a measurement result; the instantaneously measured volume Δ V is as follows:

ΔV=（π×Δd²×Δh）/4

in the formula, delta d is the average diameter of the bar stock measured instantly, and delta h is the distance between the bar stocks conveyed by a servo motor controlled by an encoder;

the expected blanking volume V is as follows:

V=∑n i=1（π×d_i ²×h_i）/4

in the formula (d)_iIs the measured instantaneous diameter;

h_ia single step feed length;

the grinding procedure comprises coarse grinding, primary additional tempering, fine grinding, secondary additional tempering and final grinding;

in the grinding step, the rotational speed of the grinding wheel is n1, the rotational speed of the workpiece is n2, and when the workpiece rotates for the second round in the finish grinding, the ratio of the rotational speed n1 of the grinding wheel to the rotational speed n2 of the workpiece is infinite acyclic decimal, and the phase shift is phi =90 °.

Further, the heat treatment process comprises normalizing, annealing and quenching;

in the normalizing procedure, a spray cooling device is arranged for each forged piece to be cooled after forging.

Further, when the grinding wheel rotates at n1, a vibration displacement X = Asin (ω τ) occurs in the horizontal direction due to problems such as grinding wheel balance.

Further, the annealing temperature is guaranteed to be 780-800 ℃, the heat preservation time is not less than 4 hours, and then the product is naturally cooled.

Furthermore, a rotary hearth type protective atmosphere quenching furnace is adopted for quenching and heating.

Compared with the prior art, the invention has the beneficial effects that:

according to the processing technology of the variable-pitch output shaft forged piece for the wind power, in the blanking forging process, an isometric blanking device is adopted, and the size precision of the forged piece is ensured; the grinding process comprises coarse grinding, primary additional tempering, fine grinding, secondary additional tempering and final grinding, the process requirements are met, and during grinding, the ratio of the workpiece rotating speed n1 to the grinding wheel rotating speed n2 is controlled to be infinite non-circulating decimal, so that the waviness of the workpiece is controlled during grinding.

Drawings

FIG. 1 shows an isometric blanking apparatus of the present invention.

Fig. 2 is a schematic diagram of the grinding of the present invention.

FIG. 3 is a development view of a general grinding surface waviness.

FIG. 4 is an expanded view of the modified abrasive surface corrugation.

Detailed Description

The following description of the embodiments of the present invention will be made with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

The invention relates to a processing technology of a variable-pitch output shaft forged piece for wind power.

In the blanking forging process, in order to ensure the dimensional accuracy of the forge piece, referring to fig. 1, an isometric blanking device is adopted; the equal-volume blanking device comprises two mutually perpendicular light transmission type measuring sensors, and the average value of the measurements of the two sensors is taken as a measurement result; the instantaneously measured volume av is estimated as follows:

ΔV=（π×Δd²×Δh）/4

in the formula, Δ d is the average diameter of the bar stock measured instantly, and Δ h is the distance of the bar stock conveyed by the servo motor controlled by the encoder.

The expected feed volume V is estimated as follows:

V=∑n i=1（π×d_i ²×h_i）/4

in the formula (d)_iIs the measured instantaneous diameter;

h_ia single step feed length;

by adopting the equal-volume blanking device, the blanking precision can be improved to 1% from 3% at present. Not only ensures the processing precision of the forging, but also saves about 2 percent of materials.

The heat treatment process comprises normalizing, annealing and quenching;

normalizing: in order to improve the quenching quality, normalizing the forged piece after the forged piece is machined; in order to avoid the occurrence of coarse grains in reticular carbide and forgings of materials, a spray cooling device is arranged for each forging needing to be cooled after forging, the fact that each surface of the forging has the same cooling speed is guaranteed, specifically, each machined forging is hung on a hook in sequence, all-around and multi-angle spatial cooling is formed in a spray box, the cooled comprehensiveness and uniformity are guaranteed, after the forging is cooled to 650 ℃ by the spray device, the forging is driven to be separated from a unhooking device at a constant speed, then the forging is rolled down to a placing area through a slide carriage and stacked, and the last stage of a cooling process is completed automatically.

Annealing: in order to further reduce the hardness and refine the lattice structure, the forge piece is completely spheroidized and tempered. The annealing temperature is maintained at 780-800 ℃, the heat preservation time is not less than 4 hours, and then the product is naturally cooled.

Quenching: the quenching adopts a multi-stage isothermal salt bath martensite quenching process to refine the structure; the quenching heating adopts a rotary hearth type protective atmosphere quenching furnace. The method can reduce the surface oxidation and decarburization of the heat treatment material, and simultaneously, the material is uniformly heated, and the occurrence of heat treatment cracks is reduced.

The grinding procedure comprises coarse grinding, primary additional tempering, fine grinding, secondary additional tempering and final grinding;

the rough grinding process adopts a domestic common grinding machine, and mainly aims to remove the residual grinding quantity after heat treatment in a large proportion. The process has low requirements on the size, the form and position precision and the surface quality of the product. Because the grinding amount of the rough grinding process is large and the grinding efficiency is high, the heat generated by grinding is large, the heat transmission of a grinding area needs to be enhanced, and the generation of grinding burn is avoided. Meanwhile, in order to eliminate grinding stress generated in the coarse grinding process, an additional tempering process is carried out after the coarse grinding, and a foundation is laid for ensuring the processing quality of the fine grinding process.

The fine grinding process adopts a domestic common grinding machine and a domestic numerical control grinding machine, and mainly aims to further reduce the residual grinding amount after heat treatment on the basis of coarse grinding, and greatly improve the size, the form and position precision and the surface quality of a product. Although the grinding amount is not large in comparison with the rough grinding, the stability and consistency of the processing accuracy of the fine grinding process are also affected to a certain extent due to the large size difference of the rough grinding process and the combined action of factors such as the grinding mode, the grinding parameters, the selected grinding wheel and the cutting fluid, and therefore, the control of each quality characteristic in the fine grinding process needs to be enhanced. In order to eliminate grinding stress generated in the fine grinding process, a secondary additional tempering process is carried out after the fine grinding, and a foundation is laid for the final grinding process.

The final grinding process adopts a foreign high-precision numerical control grinding machine, and the main purpose is to greatly improve the size, the form and position precision and the surface quality of a product on the basis of fine grinding so that the related technical indexes reach the process requirements. The final grinding process is also influenced by a plurality of factors such as grinding parameters, tools and the like in the previous working procedure and the grinding process. Therefore, various technical measures should be adopted to strictly control various process requirements of the final grinding process, particularly the working surface of the shaft, so as to meet the requirements.

Referring to fig. 2, in the grinding process, when the grinding wheel rotates at n1, due to problems such as grinding wheel balance, a vibration displacement X = Asin (ω τ) occurs in the horizontal direction; generally, the grinding wheel rotates at a much higher speed than the shaft, and if the shaft rotates one revolution and the grinding wheel is displaced 1000 reciprocations by vibration, 1000 ripples/revolution are produced on the grinding surface of the shaft. The ripple amplitude is the horizontal vibration displacement A of the grinding wheel; generally, the wheel balance accuracy cannot be zero, that is, the oscillation displacement a of the wheel is always present. Therefore, waviness of the surface of the workpiece machined under the above conditions seems unavoidable.

In the actual grinding process, in order to improve the geometric accuracy of the raceway surface, a feed-free finish grinding process is added at last, in the process, the grinding feed amount is zero, and the elastic deformation left by the previous feed in the whole grinding process completes the grinding process of gradually returning to zero from zero. During the polishing process, the workpiece is typically rotated over a dozen or so revolutions. At the beginning of the burnishing, the ground surface is left open as shown in FIG. 3 when the workpiece is rotated a first revolution. If we do nothing during the burnishing, the final workpiece surface will be rippled as shown in FIG. 3.

If we rotate the workpiece for the first revolution during the polishing process as shown in fig. 3, we shift the phase by phi =90 deg. during the second revolution, and the workpiece is ground for the second revolution, then ripples as shown in fig. 4 are left on the surface of the workpiece.

In fig. 4, it can be seen that, due to the effect of the initial phase angle, in the grinding of the second round of the workpiece, the wave crests of the waves left in the grinding of the first round are ground off, so that the amplitude of the waves is reduced to half of the original amplitude, and the number of waves is doubled.

When the workpiece rotates one circle, the phase shift of 90 degrees is formed, and after the cycle is repeated for a plurality of times, the amplitude of the ripple is reduced to the micro geometric precision allowed by the workpiece. Thereby achieving the purpose of controlling the waviness. Therefore, in actual work, the purpose of shifting the initial phase angle can be achieved by only making the ratio of the rotating speed n1 of the grinding wheel to the rotating speed n2 of the workpiece be infinite non-cyclic decimal. Finally, the waviness of the workpiece is controlled by the grinding processing. In the conventional numerically controlled grinder, the workpiece rotating speed can be regulated in a stepless manner, so that the control of the ratio of the workpiece rotating speed n1 to the grinding wheel rotating speed n2 to be an infinite non-circulating decimal is easy to realize.

According to the processing technology of the variable-pitch output shaft forged piece for the wind power, in the blanking forging process, an isometric blanking device is adopted, and the size precision of the forged piece is ensured; the grinding process comprises coarse grinding, primary additional tempering, fine grinding, secondary additional tempering and final grinding, the process requirements are met, and during grinding, the ratio of the workpiece rotating speed n1 to the grinding wheel rotating speed n2 is controlled to be infinite non-circulating decimal, so that the waviness of the workpiece is controlled during grinding.

In the above embodiments, the present invention is described only by way of example, but those skilled in the art, after reading the present patent application, may make various modifications to the present invention without departing from the spirit and scope of the present invention.