A method for processing narrow grooves

Abstract

The present invention provides a method for processing a narrow groove, wherein the narrow groove is arranged on a fuel nozzle of a nozzle vortex finder, the width of the narrow groove is less than 0.6 mm, and the depth of the narrow groove is less than 0.6 mm, and the method comprises: using a predetermined milling cutter to process the narrow groove as follows, wherein the predetermined number of milling cutter teeth is 2, and a preset spindle speed, a preset feed per tooth, and a preset cutting depth per layer are used for processing, wherein the preset spindle speed is 8000 r / min to 16000 r / min, the preset feed per tooth is 0.002-0.005 mm / r, and the preset cutting depth per layer is 0.002-0.005 mm. It can improve processing efficiency and reduce tool wear.

Description

Technical Field

[0001] The present application relates to the field of CNC milling machine processing, and in particular to a method for processing a narrow groove. Background Art

[0002] The fuel nozzle of the nozzle vortex finder is provided with two centrally symmetrical narrow grooves for introducing and spraying liquid. Since the size of the narrow groove is too small (the width of the narrow groove is less than 0.6mm, and the depth of the narrow groove is less than 0.6mm), the tool size used for milling in the past is too large to process the narrow groove. If a smaller tool size is used, the friction heat generated by the metal diameter and the small size of the tool itself will cause the tool to wear very seriously during the processing. Therefore, in the prior art, the narrow groove is usually processed by the electro-erosion method of the traditional electric spark forming electrode.

[0003] However, this processing method has low processing efficiency, and the size and surface roughness of the narrow groove are difficult to meet the requirements of the workpiece, which affects the liquid injection effect of the nozzle vortex finder.

[0004] Therefore, an efficient machining method is needed that can reduce tool wear while meeting the size and surface roughness requirements of the workpiece. Summary of the invention

[0005] In view of this, an embodiment of the present application provides a method for processing a narrow groove, which can improve processing efficiency and reduce tool wear.

[0006] In the narrow groove processing method, the narrow groove is arranged on the fuel nozzle of the nozzle vortex finder, the width of the narrow groove is less than 0.6mm, and the depth of the narrow groove is less than 0.6mm. The method includes: using a predetermined milling cutter to process the narrow groove as follows, the predetermined number of teeth of the milling cutter is 2, and the processing is performed using a preset spindle speed, a preset feed per tooth, and a preset cutting depth per layer, wherein the preset spindle speed is 8000r / min~16000r / min, the preset feed per tooth is 0.002-0.005mm / r, and the preset cutting depth per layer is 0.002-0.005mm.

[0007] Through the above settings, compared with the traditional electro-erosion machining method of electrospark forming electrodes, by adopting a small-sized milling cutter (the tool radius is smaller than the size of the narrow groove), a high spindle speed (that is, the spindle speed is greater than 5000r / min), a low feed per tooth (that is, the feed per tooth is less than 0.1mm / r) and a low cutting depth per layer (that is, the cutting depth per layer is less than 0.1mm), it is possible to reduce tool wear while ensuring the machining speed, thereby improving the machining efficiency; the method of milling in a CNC machining center is adopted to make the size and surface roughness of the narrow groove meet the requirements of the drawing.

[0008] In a possible implementation, the preset spindle speed includes a first spindle speed, a second spindle speed and a third spindle speed; the preset feed per tooth includes a first feed per tooth and a second feed per tooth; the preset cutting depth per layer includes a first cutting depth per layer and a second cutting depth per layer, and processing using the preset spindle speed, the preset feed per tooth and the preset cutting depth per layer specifically includes: processing using the first spindle speed, the first feed per tooth and the first cutting depth per layer; processing using the second spindle speed, the first feed per tooth and the first cutting depth per layer; processing using the third spindle speed, the second feed per tooth and the second cutting depth per layer, wherein the second spindle speed is greater than or equal to the first spindle speed, and the third spindle speed is greater than the second spindle speed; the second feed per tooth is greater than or equal to the first feed per tooth, and the second cutting depth per layer is greater than or equal to the first cutting depth per layer.

[0009] By machining narrow grooves with gradually increasing spindle speed, gradually increasing feed per tooth and cutting depth per layer, the rapid temperature rise between the tool and the fuel nozzle component caused by the higher spindle speed can be reduced, while the faster tool wear caused by the one-time larger feed per tooth and cutting depth per layer can be reduced; in addition, the gradually increasing spindle speed and gradually increasing feed per tooth increase the machining speed and ensure the machining efficiency.

[0010] In a possible implementation, the first feed per tooth is 0.002-0.003 mm / r.

[0011] In a possible implementation, the second feed per tooth is 0.003-0.005 mm / r.

[0012] In a possible implementation, the first cutting depth per layer is 0.003-0.005 mm.

[0013] In a possible implementation, the second cutting depth per layer is 0.005-0.007 mm.

[0014] In a possible implementation, the first spindle has a rotation speed of 8000-10000 r / min.

[0015] In a possible implementation, the second spindle has a rotation speed of 10000-12000 r / min.

[0016] In a possible implementation, the third spindle has a rotation speed of 12000-16000 r / min.

[0017] In a possible implementation, the fuel nozzle of the nozzle vortex finder is made of 1Cr18Ni9Ti\1Cr13, and the width of the narrow groove is The depth of the narrow groove The tip diameter of the predetermined milling cutter is 0.5 mm. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The various technical features of the present application and the relationship between them are further explained below with reference to the accompanying drawings. The accompanying drawings are exemplary, and some technical features are not shown in actual proportion. In addition, some drawings may omit technical features that are commonly used in the technical field to which the present application belongs and are not essential for understanding and implementing the present application, or additionally show technical features that are not essential for understanding and implementing the present application. In other words, the combination of the various technical features shown in the accompanying drawings is not used to limit the present application. In addition, throughout the present application, the same figure numbers refer to the same content. The specific description of the drawings is as follows:

[0019] Figure 1 It is a schematic diagram of a fuel nozzle provided with a nozzle swirler with narrow grooves provided in an embodiment of the present application.

[0020] Figure 2 It is a flow chart of the narrow groove processing method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0021] Below, the specific implementation methods of the present application are described in detail with reference to the accompanying drawings.

[0022] Figure 1 A fuel nozzle 100 of a nozzle vortex finder provided with a narrow groove provided in an embodiment of the present application is shown. The fuel nozzle of the nozzle vortex finder is a cylinder with a cylindrical flange 15, and a circular through hole 14 is provided through the column axis of the cylinder, and the narrow groove 10 is provided on the upper surface of the flange 15. The material of the fuel nozzle of the nozzle vortex finder is 1Cr18Ni9Ti\1Cr13. The narrow groove 10 includes a first narrow groove 11 and a second narrow groove 12, and the narrow groove 10 is linear, and the first narrow groove 11 and the second narrow groove 12 extend linearly from the circumference of the flange to the circumference of the through hole 14, respectively, and are symmetrical relative to the center of the column axis of the cylinder. The fluid is introduced through the first narrow groove 11 and ejected through the second narrow groove 12. The cross-section of the narrow groove 10 is rectangular, wherein the depth of the narrow groove is less than 0.6 mm, and the width of the narrow groove is less than 0.6 mm. Figure 1 In the example shown, the width of the narrow slot is The depth of the narrow groove

[0023] Since the narrow groove of the fuel nozzle is too small, the tool size of milling is too large to process the narrow groove. If a smaller tool is used, the friction heat generated by the metal diameter and the small size of the tool itself will cause the tool to wear very seriously during the processing. Therefore, the electro-erosion processing method using an electro-spark forming electrode is used in the prior art. It mainly includes the following steps: aligning the special fixture on the spark machine tool; fixing the fuel nozzle of the nozzle vortex generator on the special fixture and clamping the special electrode, wherein the thickness of the electrode is 0.53 (+0.01, 0); adjusting the machine tool processing parameters; according to the electrode counterface on the fixture, translating the size, processing two grooves; measuring the depth with a measuring tool, and removing the fuel nozzle after the depth meets the drawing size. Then the position and roughness tests are carried out. According to experiments, this processing method is inefficient (i.e., 10 fuel nozzle parts take 100 minutes to process), and the position and roughness test results do not meet the drawing requirements (where the narrow groove depth requirement is The narrow slot width requirement is The surface roughness of the narrow groove is required to be less than Ra1.6).

[0024] In view of this, an embodiment of the present application provides a narrow groove processing method, which uses a special milling cutter to perform processing on a CNC machining center, has high processing efficiency, low tool wear, and meets the size and surface roughness requirements of the workpiece.

[0025] The tool used in the narrow groove processing method provided in the embodiment of the present application is a flat milling cutter, which has 2 teeth and a tip diameter of 0.5 mm.

[0026] Figure 2 is a flow chart of a narrow groove processing method provided in an embodiment of the present application, such as Figure 2 As shown, the narrow groove processing method provided in the embodiment of the present application includes:

[0027] Using the preset spindle speed, the preset feed per tooth and the preset cutting depth per layer, processing is performed along the extension direction of the narrow groove until the size of the narrow groove meets the requirements of the drawing.

[0028] The depth of the narrow groove is less than 0.6 mm, the width of the narrow groove is less than 0.6 mm, the preset spindle speed is 8000 r / min to 16000 r / min, the preset feed per tooth is 0.002-0.005 mm / r, and the preset cutting depth per layer is 0.002-0.005 mm.

[0029] Compared with the traditional electro-erosion machining method of electric spark forming electrodes, this application can reduce tool wear while ensuring machining speed, thereby improving machining efficiency, by adopting a small-sized milling cutter (the tool radius is smaller than the size of the narrow groove), a high spindle speed (i.e., the spindle speed is greater than 5000r / min), a low feed per tooth (i.e., the feed per tooth is less than 0.1mm / r), and a low cutting depth per layer (i.e., the cutting depth per layer is less than 0.1mm); the milling method in a CNC machining center is used to make the size and surface roughness of the narrow groove meet the requirements of the drawing.

[0030] Table 1 shows the results of multiple experiments conducted by the inventors of this application on narrow groove machining on workpieces made of 1Cr18Ni9Ti\1Cr13. The unit of spindle speed is r / min, the unit of feed per tooth is mm / r, the unit of cutting depth per layer is mm, and the unit of position accuracy is mm. The position accuracy requirement of the narrow groove is the range (sum1~sum2) consisting of the sum of the upper deviation of the narrow groove depth and the upper deviation of the narrow groove width sum1 and the sum of the lower deviation of the narrow groove width and the lower deviation of the narrow groove depth sum2. That is, the narrow groove depth requirement is 0.05 is the upper deviation of the narrow groove depth, 0 is the lower deviation of the narrow groove, and the narrow groove width requirement is 0.03 is the upper deviation of the narrow slot width, 0 is the lower deviation of the narrow slot, and the position accuracy is required to be within 0~0.08.

[0031] Table 1

[0032]

[0033]

[0034]

[0035]

[0036]

[0037] It can be seen from Table 1 that when the spindle speed is within the range of 8000-10000 r / min, the cutting depth of each layer is within the range of 0.03-0.07 mm and the feed per tooth is within the range of 0.002-0.005 mm / r, the position and roughness measured after processing are within the required range.

[0038] The processing using a preset spindle speed, a preset feed per tooth, and a preset cutting depth per layer may specifically include the following steps:

[0039] Step S1: machining the narrow groove with a first spindle speed, a first feed per tooth, and a first cutting depth per layer.

[0040] Among them, the first spindle speed is greater than or equal to 8000r / min, preferably, the first spindle speed is 8000-10000r / min; the first feed per tooth is 0.002-0.003mm / r; the first cutting depth per layer is 0.003-0.005mm.

[0041] Step S2: machining the narrow groove using a second spindle speed, a first feed per tooth, and a first cutting depth per layer.

[0042] The second spindle speed is greater than the first spindle speed. Preferably, the second spindle speed is 10000-12000 r / min.

[0043] Step S3: machining the narrow groove by adopting the third spindle speed, the second feed per tooth and the second cutting depth per layer.

[0044] Wherein, the third spindle speed is greater than the second spindle speed, the second feed per tooth is greater than the first feed per tooth, and the second cutting depth per layer is greater than the first cutting depth per layer. Preferably, the third spindle speed is 12000-16000r / min. The second feed per tooth is 0.003-0.005mm / r. The second cutting depth per layer is 0.005-0.007mm.

[0045] In step S1, step S2 and step S3, there is no limit on the cutting depth achieved in each step. According to the performance of the machine tool used, the parameters of step S1 can be used to process the narrow groove to 1 / 3 of the target depth; the parameters of step S2 can be used to process the narrow groove to 2 / 3 of the target depth; and the parameters of step S3 can be used to process the narrow groove to the target depth. The parameters of step S1 can also be used to process the narrow groove to 2 / 3 of the target depth; the parameters of step S2 can be used to process the narrow groove to 1 / 6 of the target depth; and the parameters of step S3 can be used to process the narrow groove to any depth respectively, until the narrow groove meets the target depth and target size.

[0046] By machining narrow grooves with gradually increasing spindle speed, gradually increasing feed per tooth and cutting depth per layer, the rapid temperature rise between the tool and the fuel nozzle caused by the higher spindle speed can be reduced, and the faster tool wear caused by the one-time larger feed per tooth and cutting depth per layer can be reduced; in addition, the gradually increasing spindle speed and gradually increasing feed per tooth increase the machining speed and ensure the machining efficiency.

[0047] It should be noted that, according to the applicable machine tool model, the number of processing times and the spindle speed, feed per tooth and cutting depth per layer during each processing can be adjusted. For example, a spindle speed of 12000r / min, a feed per tooth of 0.004mm / r and a cutting depth per layer of 0.004 can be used to process a narrow groove to its target depth; a spindle speed of 10000r / min, a feed per tooth of 0.004mm / r and a cutting depth per layer of 0.005 can also be used to process a narrow groove to 1 / 2 of its depth; and then a spindle speed of 14000r / min, a feed per tooth of 0.004mm / r and a cutting depth per layer of 0.005 can be used to process a narrow groove to its target depth.

[0048] Next, we describe the Figure 2 Tool processing shown Figure 1 The specific method of the narrow groove is shown.

[0049] Step S10: Place the fixture on the vertical machining center machine, align the fixture, and fix the fuel nozzle (hereinafter referred to as the component) on the fixture.

[0050] Step S20: Fix the tool on the spindle of the machine tool.

[0051] The tool is Figure 2 The plane milling cutter shown is described above in detail.

[0052] Step S30: Calling the NC program, Figure 2 The face milling cutter shown processes the first narrow groove and the second narrow groove in layers.

[0053] In step S30, it specifically includes:

[0054] Step S31: Use a spindle speed of 9000r / min, a cutting depth of 0.004mm per layer and a feed per tooth of 0.003mm / r to start processing from one end of the first narrow groove or the second narrow groove located on the outer circumference. Among them, the feed speed is 0.216mm / min, and the feed speed is calculated according to the formula Vf=n×fz×Z, where: Vf is the feed speed (mm / min), n is the spindle speed (r / min), fz is the feed per tooth (mm / r), and Z is the number of milling cutter teeth.

[0055] Step S32: using a spindle speed of 11000 r / min, a cutting depth of 0.004 mm per layer and a feed rate per tooth of 0.003 mm / r, a second machining is performed from one end of the first narrow groove or the second narrow groove located on the outer circumference.

[0056] Step S33: With a spindle speed of 15000 r / min, a cutting depth of 0.005 mm per layer and a feed rate per tooth of 0.006 mm / r, a third machining is performed from one end of the first narrow groove or the second narrow groove located on the outer circumference.

[0057] Step S40: After processing is completed, the depth is measured with a measuring tool, and the component is removed when the depth meets the drawing standard.

[0058] Step S50: Detect the position and roughness of the component.

[0059] Among them, after measurement, the position accuracy of the component is 0.05-0.07 and the roughness is Ra0.8-Ra1.6, which meets the roughness and position accuracy requirements of the workpiece. In addition, it takes about 30 minutes to process 10 components using steps S10 to S50, which greatly improves the processing efficiency compared to 100 minutes.

[0060] The words "first, second, third, etc." or module A, module B, module C and the like used throughout this application are only used to distinguish similar objects and do not represent a specific ordering of the objects. It is understood that the specific order or sequence can be interchanged where permitted.

[0061] Throughout the present application, the numbers used to represent the steps, such as S10, S20, etc., do not necessarily mean that the steps must be executed in this manner. If permitted, the order of the steps can be interchanged, or the steps can be executed simultaneously.

[0062] The term "comprising" used throughout this application should not be interpreted as being limited to the contents listed thereafter; it does not exclude other structural elements or steps. Therefore, it should be interpreted as specifying the existence of the technical features, integral bodies, steps or components mentioned, but does not exclude the existence or addition of one or more other technical features, integral bodies, steps or components and groups thereof.

[0063] It can be understood that those skilled in the art can combine the features mentioned in one or more embodiments mentioned in the entire application with the features in other embodiments in any appropriate manner to implement the application.

[0064] Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may also include more other equivalent embodiments without departing from the technical concept of the present application, all of which belong to the protection scope of the present application.

Claims

1. A method for processing a narrow groove, wherein the narrow groove is provided on a fuel nozzle of a nozzle vortex finder, the width of the narrow groove is less than 0.6 mm, the depth of the narrow groove is less than 0.6 mm, and the method is characterized in that: include: The narrow groove is processed as follows using a predetermined milling cutter, wherein the predetermined milling cutter has 2 teeth. The preset spindle speed, the preset feed per tooth and the preset cutting depth per layer are used for machining, wherein the preset spindle speed is 8000r / min~16000r / min, the preset feed per tooth is 0.002-0.005mm / r, and the preset cutting depth per layer is 0.002-0.005mm; The preset spindle speed includes a first spindle speed, a second spindle speed and a third spindle speed; the preset feed per tooth includes a first feed per tooth and a second feed per tooth; the preset cutting depth per layer includes a first cutting depth per layer and a second cutting depth per layer, and machining using the preset spindle speed, the preset feed per tooth and the preset cutting depth per layer specifically includes: Machining is performed using a first spindle speed, a first feed per tooth, and a first cutting depth per layer; Machining is performed using the second spindle speed, the first feed per tooth, and the first cutting depth per layer; The third spindle speed, the second feed per tooth and the second cutting depth per layer are used for machining. Wherein, the second spindle speed is greater than or equal to the first spindle speed, the third spindle speed is greater than the second spindle speed; the second feed per tooth is greater than or equal to the first feed per tooth, and the second cutting depth per layer is greater than or equal to the first cutting depth per layer; The first feed per tooth is 0.002-0.003mm / r, the second feed per tooth is 0.003-0.005mm / r; the first cutting depth per layer is 0.003-0.005mm; the second cutting depth per layer is 0.005mm, the first spindle speed is 8000-10000r / min, the second spindle speed is 10000-12000r / min, the third spindle speed is 12000-16000r / min, the fuel nozzle of the nozzle vortexer is made of 1Cr18Ni9Ti\1Cr13, the width of the narrow groove is , the depth of the narrow groove The tip diameter of the predetermined milling cutter is 0.5 mm.

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