CN109773660B - Polymer matrix composite thick plate abrasive water jet finish machining method - Google Patents

Abstract

The invention discloses an abrasive water jet finish machining method of a polymer matrix composite thick plate, which comprises the following steps: selecting a processing scheme according to a first processing mode of a workpiece to be processed; and selecting a processing scheme according to the shape of the notch of the workpiece to be processed. The invention carries out one or more times of processing along the same track after single cutting processing, or carries out processing parallel to the original track after micro-feeding along the direction of the perpendicular line of the tangent direction of the original track, and compared with single cutting processing, the processing quality is better. The method and the combination thereof can not only improve the processing size and the form and position precision of the abrasive water jet on the premise of ensuring the processing efficiency, but also remove inherent defects of notch conicity, notch side wall stripe area, higher surface roughness at the bottom of the notch side wall and the like brought by the traditional abrasive water jet processing method, and realize the consistency of the processing surface roughness from top to bottom. The method can be further applied to hole opening, turning and forming of the convex curved surface, and can be used as subsequent processing of other processing methods to further improve the precision and eliminate defects.

Description

A kind of polymer matrix composite thick plate abrasive water jet finishing method

technical field

The invention relates to the cutting and hole-opening technology of various materials by abrasive water jets, in particular to an abrasive water jet finishing method for thick plates of polymer-based composite materials.

Background technique

At present, the commonly used methods for improving the quality of abrasive water jet machining include optimization of various process parameters of abrasive water jet when facing different workpiece conditions, cutting head oscillation technology, and multi-pass machining technology. However, for materials with a thickness of more than 10mm, due to the unique formation method, jet structure and processing mechanism of the abrasive water jet, the workpiece will still form a relatively rough bottom incision quality during its processing, which is embodied in the sidewall stripe area of the incision, Cut taper and greater surface roughness at the bottom of the cut side walls. According to the cutting capabilities of current commercial abrasive water jet equipment, bottom defects are unavoidable and become an inherent disadvantage of this processing method. How to improve the abrasive water jet machining accuracy and surface quality of thick plate materials is one of the urgent problems to be solved in abrasive water jet machining.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problems existing in the prior art, the present invention aims to design an abrasive water jet finishing method suitable for thick plate materials, especially thick plates of polymer-based composite materials, which can not only improve the abrasive water flow under the premise of ensuring processing efficiency. The size and shape and position accuracy of jet machining can be removed, and the inherent defects such as notch taper, notch sidewall stripe area and high surface roughness at the bottom of the notch sidewall caused by the traditional abrasive water jet machining method can be removed, so as to form high-quality It can be further applied to drilling, turning and forming of convex surfaces, and can be used as the follow-up processing of other processing methods to further improve accuracy and eliminate defects.

In order to achieve the above object, the technical scheme of the present invention is as follows: a polymer-based composite material thick plate abrasive water jet finishing method, comprising the following steps:

A. Select the processing plan according to the first processing method of the workpiece to be processed

If the workpiece to be processed adopts abrasive water jet processing for the first time, then go to step B; otherwise, go to step C;

B. Select the processing plan according to the shape of the incision of the workpiece to be processed

If there are machining accuracy requirements for both sides of the incision, that is, both sides of the incision need to be retained for processing, go to step B1; if there are machining accuracy requirements for only one side incision, that is, only one incision is required for processing, and the other side incision is required. If there is no processing requirement as excess material, go to step B2;

B1, bilateral incision processing

B11. Reserved finishing allowance

Reserve the finishing allowance according to the material properties, size and shape and position accuracy of the workpiece; determine the cutting path;

Among them, the calculation formula of reserved finishing allowance is:

Then the actual processing size is:

where:

_{γReservation} and γ are the predicted top width of one-half notch and the actual one-half top width of the notch, respectively;

εj _reserved and εj are the component of the predicted _jth finishing feed along the vertical direction of the tangent direction of the previous machining track and the actual jth finishing feed along the tangent of the last machining track. The component in the vertical direction of the direction, j∈[1,+∞); ε _j ∈ [0,2r), r is the jet radius, when ε _j = 0, there is no advance along the vertical direction of the tangential direction of the previous machining track. The given amount is regarded as not to perform finishing; m is the number of finishing operations, m∈[1,+∞);

和

分别为预测第i组光切加工对材料顶平面的去除量和实际第i组光切加工对材料顶平面的去除量；x_i为第i组光切加工连续光切加工次数，x_i∈[0,+∞)；n为光切加工组数，n∈[1,+∞)；

and

are the predicted removal amount of the i-th group of light-cutting processing on the top plane of the material and the actual removal amount of the i-th group of light-cutting processing on the top plane of the material; x _i is the number of consecutive light-cutting operations of the i-th group of light-cutting processing, x _i ∈ [0,+∞); n is the number of light cutting groups, n∈[1,+∞);

_{ΔReservation} and Δ are respectively the accumulated error amount in the predicted machining process and the accumulated error amount in the actual machining process;

B12, rough machining

According to the determined machining path, the abrasive water jet machining is carried out at the feed speed of k ₀ v ₀ , and the bilateral incision with the top width of 2γ is machined; k ₀ ≥1; v ₀ is the same parameter machining in the conventional machining method, and the machining quality The highest feed speed within the specified range of conventional processing methods; v ₀ ≤ v _separation , k ₀ v ₀ ≤ v _separation ; v _separation is the highest speed that cuts the material without causing delamination defects;

B13, light cutting

Abrasive water jet light cutting is performed along the original machining track at the feed speed of k ₂ v ₀ , that is, no feed machining is performed along the original track; k ₂ ≥1;

B14. Selection of processing method

否则，转向步骤B13；Select the processing method. If the notch accuracy reaches the specified machining accuracy or there is no excess material to be removed by continuing the no-feed processing, the processing stops. At this time, the top width of the notch is wide.

Otherwise, go to step B13;

B2, unilateral incision processing

B21. Reserved finishing allowance

Reserve the finishing allowance according to the material properties, size and shape and position accuracy of the workpiece; determine the cutting path;

Among them, the calculation formula of reserved finishing allowance is:

Then the actual processing size is:

B22, rough machining

Carry out abrasive water jet machining at the feed speed of k ₀ v ₀ according to the determined machining track, and after machining the bilateral incision, keep the incision side in the original position with machining accuracy requirements;

B23. Selection of processing method

或者形位精度及表面质量无法通过无进给加工达到规定要求，转向步骤B24；否则，转向步骤B26；Select the processing method, if the dimensional accuracy is

Or the shape and position accuracy and surface quality cannot meet the specified requirements through no-feed machining, go to step B24; otherwise, go to step B26;

B24, finishing machining

Abrasive water jet fine-cutting is performed on the workpiece, that is, after the feed amount along the vertical direction of the tangential direction of a machining track on the abrasive water jet is not more than one time the diameter of the jet, the amount of feed is k ₁ v ₀ . The feed speed is used for processing along the parallel direction of the previous processing track of the abrasive water jet; k ₁ ≥ 1;

B25. Selection of processing method

Select the processing method, if the notch precision reaches the specified processing precision, the processing stops; otherwise, turn to step B26;

B26, light cutting

Abrasive water jet optical cutting is performed along the last machining track, that is, no feed machining is performed along the last machining track at a feed speed of k ₂ v ₀ .

B27. Selection of processing method

Select the processing method. If the machining accuracy of the incision meets the specified requirements, the processing will stop; if the incision accuracy does not meet the specified requirements, select the steps according to the machining conditions of the part: if the non-feed machining continues, there is still excess material to be removed, that is, in the size In terms of accuracy, the following formula is satisfied:

Or the shape and position accuracy and surface quality do not meet the specified requirements, turn to step B26; if the workpiece reaches the specified shape and position accuracy or continues to perform no-feed processing, there is no excess material to be removed, and the dimensional accuracy has not yet been reached, that is, the dimensional accuracy meets the following requirements. Mode:

Or the shape and position accuracy and surface quality of the workpiece cannot meet the specified requirements through no-feed machining, and turn to step B24;

In the formula, x is the number of times of fine cutting, x≥1; y is the number of groups that have been cut, y≥1;

C. Follow-up processing of other processing methods

C1. Reserve finishing allowance

Reserve the finishing allowance according to the material properties, size and shape and position accuracy of the workpiece; determine the cutting path;

Among them, the calculation method of reserved finishing allowance is:

Then the actual processing size is:

C2, rough machining

According to the machining method or other special processing method, the unilateral or bilateral incision is processed;

C3, fine cutting

The abrasive water jet fine cutting is performed on the side with machining accuracy requirements, that is, after the feed amount in the vertical direction of the tangential direction of the original machining boundary does not exceed one time of the jet diameter; with k ₁ v ₀ The feed speed is used for processing along the parallel direction of the original processing boundary;

C4, processing method selection

Select the processing method, if the cutting precision reaches the specified processing precision, the processing stops; otherwise, turn to step C5;

C5, light cutting

Abrasive water jet optical cutting is performed along the previous processing track, that is, no feed processing is performed along the previous processing track at the feed speed of k ₂ v ₀ .

C6. Selection of processing method

Select the processing method. If the machining accuracy of the incision meets the specified requirements, the processing will stop; if the incision accuracy does not meet the specified requirements, select it according to the machining conditions of the parts: if the non-feed machining continues, there is still excess material to be removed, that is, in the dimensional accuracy. The aspect satisfies the following formula:

Or the shape and position accuracy and surface quality do not meet the specified requirements, go to step C5; if the workpiece reaches the specified shape and position accuracy or continues to perform no-feed processing, there is no excess material to be removed, and the dimensional accuracy has not yet been reached, that is, the dimensional accuracy meets the following requirements. Mode:

Or the shape and position accuracy and surface quality of the workpiece cannot meet the specified requirements through no-feed machining, and turn to step C3;

x is the number of times of fine cutting, x≥1; y is the number of groups that have been cut, y≥1.

Compared with the prior art, the present invention has the following beneficial effects:

In the present invention, after a single cutting process, one or more times of processing along the same trajectory and micro-feeding along the vertical direction of the tangential direction of the original trajectory are performed, and then the processing parallel to the original trajectory is carried out. Compared with the single cutting process, the processing Better quality. This process can not only improve the size and shape accuracy of abrasive water jet machining under the premise of ensuring machining efficiency, but also can improve the notch taper, the striped area of the notch sidewall and the bottom of the notch sidewall caused by the traditional abrasive waterjet machining method. The inherent defects such as the surface roughness of the machine are removed to achieve the top-down consistency of the surface roughness of the machined surface. It can be further applied to drilling, turning and forming of convex surfaces, and can be used as the follow-up processing of other processing methods to further improve accuracy and eliminate defects.

Description of drawings

Figure 1 is a schematic diagram of the application of the abrasive water jet finishing method in the cutting process.

FIG. 2 is a schematic diagram of the application of the abrasive water jet finishing method in the drilling process.

Figure 3 is a schematic diagram of the application of the abrasive water jet finishing method in turning.

FIG. 4 is a schematic diagram of the application of the abrasive water jet finishing method in the forming process of the convex surface.

FIG. 5 is a schematic diagram of the method of reserving the allowance for abrasive water jet finishing.

FIG. 6 is a schematic diagram of a single cutting process of abrasive water jet.

Figure 7 is a schematic diagram of the morphology of the abrasive water jet after a single cutting process.

Figure 8 is a schematic diagram of the abrasive water jet light cutting process (for both sides).

FIG. 9 is a schematic diagram of the morphology after abrasive water jet optical cutting (double-sided incision).

Figure 10 is a schematic diagram of the abrasive water jet multiple light cutting process (for both sides).

Figure 11 is a schematic diagram of the morphology of the abrasive water jet after multiple optical cutting (double-sided incision).

Figure 12 is a schematic diagram of a single cutting process of abrasive water jet.

Figure 13 is a schematic diagram of the morphology of the abrasive water jet after a single cutting process.

Figure 14 is a schematic diagram of the abrasive water jet light cutting process (for one side).

FIG. 15 is a schematic diagram of the morphology after abrasive water jet optical cutting (single edge incision).

FIG. 16 is a schematic diagram of the multi-pass light cutting process by abrasive water jet (for one side).

FIG. 17 is a schematic diagram of the topography (single-side incision) after multiple optical cutting with abrasive water jets.

FIG. 18 is a schematic diagram of the single cutting process of abrasive water jet.

Figure 19 is a schematic diagram of the morphology of the abrasive water jet after a single cutting process.

Figure 20 is a schematic diagram of the abrasive water jet finishing process.

FIG. 21 is a schematic diagram of the morphology after the abrasive water jet finishing process.

FIG. 22 is a schematic diagram of the light-cutting process after the abrasive water-jet finishing process.

FIG. 23 is a schematic diagram of the topography of the abrasive water jet fine-cutting and the light-cutting process.

Figure 24 is a schematic diagram of traditional processing or other processing methods.

FIG. 25 is a schematic diagram of the morphology after processing by conventional processing or other processing methods.

Figure 26 is a schematic diagram of the abrasive water jet finishing process.

Figure 27 is a schematic diagram of the morphology after the abrasive water jet finishing process.

FIG. 28 is a schematic diagram of the light-cutting process after the abrasive water-jet finishing process.

FIG. 29 is a schematic view of the topography of the abrasive water jet finishing process after the light cutting process is carried out.

Figure 30 is a flow chart of a method for abrasive water jet finishing of a thick plate of a polymer matrix composite material.

In the picture: 1. Abrasive water jet, 2. Workpiece, 3. Abrasive water jet processing nozzle.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings. D is the diameter of abrasive water jet 1 in the figure.

In Figures 1-4, the application of a polymer matrix composite thick plate abrasive water jet finishing method in several different processing scenarios of cutting, drilling, turning and forming of convex surfaces is listed. The method is shown in Figure 30, and the specific processing implementation is as follows:

Carry out step B11 according to the method shown in Fig. 5 to reserve the finishing allowance. The actual machining sequence and the influence of each machining method on the dimensional accuracy may be different from those reserved, but it should be ensured that the machining accuracy of the incision finally meets the specified requirements, namely |∑-∑ _Reserved | Within the dimensional tolerance range and the shape and position accuracy and surface quality meet the specified requirements.

In Fig. 6-11, after the machining allowance is reserved in step B11, the workpiece 2 is subjected to the step B12 abrasive water jet machining according to the predetermined machining trajectory to cut the workpiece 2, and then the step B13 abrasive water jet light cutting process is performed, and can be processed in step B13. After that, it is determined whether to supplement the abrasive water jet light cutting process (multiple times) in step B13 according to the selection result of the processing method in step B14.

In Fig. 12-17, after the machining allowance is reserved in step B21, the workpiece 2 is subjected to the abrasive water jet machining in step B22 according to the predetermined machining trajectory to cut off the workpiece 2, and then it is determined whether to carry out the abrasive material in step B26 according to the result of the selection of the machining method in step B23. After step B26, it can be determined whether to supplement the abrasive water jet light cutting process (multiple times) according to the selection result of the processing method in step B27.

In Fig. 18-23, after the machining allowance is reserved in step B21, the workpiece 2 is subjected to the abrasive water jet machining in step B22 according to the predetermined machining trajectory to cut off the workpiece 2, and then it is determined whether to proceed with the abrasive material in step B24 according to the selection result of the machining method in step B23. Water jet finishing, then it can be determined whether to supplement the abrasive water jet light cutting in step B26 (multiple times) according to the selection result of the processing method in step B25, and then it can be determined to continue to step B24- In step B26, the combination is processed or the processing is stopped.

Or as shown in Figure 30, after the machining allowance is reserved in step B21 and the abrasive water jet machining in step B22 is performed according to the predetermined machining trajectory to cut off the workpiece 2, step B24 and step B26 can be freely combined according to the actual machining situation to achieve the machining accuracy of the incision. When the specified requirements are met, that is, the |∑-∑ _reservation | is within the dimensional tolerance range and the shape and position accuracy and surface quality meet the specified requirements, the processing stops.

In Fig. 24-29, after the machining allowance is reserved in step C1, the workpiece 2 is subjected to step C2 machining or other special processing methods according to the predetermined processing path to cut off the workpiece 2, and then step C3 abrasive water jet finishing is performed. After that, it can be determined whether to supplement the abrasive water jet light cutting process in step C5 (multiple times) according to the selection result of the processing method in step C4, and then according to the selection result of the processing method in step C6, it can be determined to continue to perform the processing combination of step C3-step C5 or Processing stops.

Or as shown in Figure 30, after workpiece 2 reserves machining allowance in step C1 and performs machining in step C2 or other special processing methods according to the predetermined machining trajectory to cut workpiece 2, freely combine steps C3 and C3 according to the actual processing situation. In step C5, when the machining accuracy of the incision meets the specified requirements, that is, |∑-∑ _reserved | is within the dimensional tolerance range and the shape and position accuracy and surface quality meet the specified requirements, the processing stops;

The present invention will be further described with reference to specific embodiments.

Aramid fiber refers to an aramid fiber that has been industrially produced and widely used. The foreign trade name is Kevlar, which is an organic fiber with sufficient stiffness and strength. Aramid fiber is widely used in bulletproof and aerospace fields for its advantages of low density, high elastic modulus, high tensile strength, good impact performance, good thermal stability, and good medium resistance. cover, etc. However, its good mechanical properties also become a serious obstacle to its mechanical processing, so abrasive water jet processing is considered as a feasible method for cutting aramid fiber composites, and can minimize the amount of fiber scattering in the air.

In the process of processing the 50mm thick aramid fiber composite material, the aramid fiber composite material workpiece 2 reserves the machining allowance in step B11 according to the predetermined processing trajectory, with a pressure of 390MPa, an abrasive flow of 600g/min, and a feed of 40mm/min The processing parameters of the speed and the target distance of 2mm (the specific processing parameters depend on the properties of the material, the selected feed speed should be lower than the maximum speed that can cut the material without causing delamination defects) and perform step B12 abrasive water jet processing to process the aromatics. The fiber composite material workpiece 2 is vertically cut, and then the abrasive water jet light cutting process in step B13 is performed with the same parameters, and according to the selection result of the processing method in step B14, two identical workpieces are supplemented 0 times and once in step B13 abrasive water jet Streamer cutting.

Abrasive water jet processing in step B12 was performed on the same material at a feed speed of 40 mm/min and 20 mm/min respectively (other parameters were the same) to cut off the aramid fiber composite workpiece 2, and its processing plane was used as a comparison.

The average value of three measurements at different positions at the same processing depth with the Taylor surface profilometer is taken as the surface roughness (unit: μm) at the processing depth, and the processing thickness of the workpiece is divided into five equal parts, and the surface at the top and bottom four-fifths of the thickness is The difference between the roughness Ra _4/5 and the surface roughness Ra _1/5 at one-fifth of the thickness △Ra is used as the evaluation standard for the consistency of the machined surface roughness (△Ra=Ra _4/5 -Ra _1/5 ); The shortest processing time t that can cut off the material is used as the unit time to measure the processing efficiency, and the processing time is T; the angle between the processing plane and the top plane measured by the three-coordinate measuring instrument is used as the evaluation standard for the taper of the incision; the above five The processing quality and efficiency of large-thickness aramid fiber composites are compared as follows:

Table 1 Abrasive water jet single cutting processing and light cutting processing quality and efficiency comparison table

Ra_1/5 Ra_2/5 Ra_3/5 Ra_4/5 △Ra θ T 40mm/min cut off 6.4258 7.5809 9.9593 11.9032 5.4774 - t 20mm/min cut off 6.0131 7.1635 9.7687 11.7308 5.7177 58′16″ 2t After cutting at 40mm/min, light cut once with the same parameters 5.7300 6.4050 5.9704 6.5839 0.8538 5′58″ 2t After cutting at 40mm/min, light-cut twice with the same parameters 5.1150 5.3787 5.9297 6.2213 1.1063 -1′47″ 3t

The aramid fiber composite material workpiece 2 reserves the machining allowance in step B21 according to the predetermined machining trajectory, with 390MPa pressure, 600g/min abrasive flow, 40mm/min feed speed and 2mm target distance processing parameters (specific processing parameters depend on Depending on the material properties, the selected feed speed should be lower than the maximum speed that can cut the material) Perform step B22 abrasive water jet machining to cut workpiece 2 vertically, and then decide to proceed to step B24 abrasive water according to the selection result of the processing method in step B23 Jet finishing, feed rate 0.1mm.

Table 2. Comparison of surface quality and efficiency of abrasive water jet single cutting, light cutting and finishing

Ra_1/5 Ra_2/5 △Ra_(2/5-1/5) Ra_3/5 △Ra_(3/5-1/5) Ra_4/5 △Ra T 40mm/min cut off 6.4258 7.5809 1.1551 9.9593 3.5335 11.9032 5.4774 t 20mm/min cut off 6.0131 7.1635 1.1504 9.7687 3.7556 11.7308 5.7177 2t After cutting at 40mm/min, light cut once with the same parameters 5.7300 6.4050 0.6750 5.9704 0.2403 6.5839 0.8538 2t Finishing with the same parameters after 40mm/min cutting 5.0105 5.0341 0.0236 5.2783 0.2678 7.0454 2.0349 2t

It can be seen from the above embodiment that the abrasive water jet optical cutting process is performed in the case of a single machining cut, that is, the continuous non-feed machining along a machining track on the abrasive water jet 1 can eliminate the single-shot cutting process with a large margin removed. During the process, the quality of the rough bottom cut formed due to the continuous consumption of the energy of the abrasive water jet 1 by the large-thickness material is improved. There is no large amount of material that needs to be removed in a single processing, which consumes the energy of the jet, and the jet can easily remove the part that is not fully processed in a single processing during the no-feed processing. This can effectively extend the depth of the smooth cutting zone. In the no-feed machining process itself, since there is no backward deflection of the jet, no new bottom stripe region defects are generated after machining, so that the target surface can be machined into a nearly damage-free surface with abrasive water jet machining with high machining accuracy.

In the case of single machining and cutting, the abrasive water jet fine cutting process is performed, that is, after the projection of the feed amount in the vertical direction of the tangential direction of a machining track on the abrasive water jet 1 does not exceed one time of the jet diameter. Processing along the parallel direction of the previous processing track of abrasive water jet 1 can also effectively remove the striped area at the bottom of the sidewall of the incision, the taper of the incision and the higher surface roughness at the bottom of the sidewall of the incision within the range of its processing capacity (related to the feed rate). Degree and other processing defects. Although the increase of the material to be removed accelerates the loss of jet energy, the improvement of the depth of the smooth area (related to the feed) by the finishing process is not as good as that of the abrasive water jet light cutting process under the same other parameters, but the feed The change results in material removal from top to bottom on the cut surface of workpiece 2, which makes the surface topography of the finely machined incision sidewall show strong consistency with the increase of machining depth. And within the depth range of the elevated smooth cutting area, the fine cutting process can effectively reduce the kerf taper and provide a greater reduction in the surface roughness of the kerf sidewall than the abrasive water jet light cutting process. The small amount of material removal makes the jet flow without obvious backward deflection during the feeding process of fine cutting with the same parameters, and because there is a wide space outside without the limitation of processing materials, the jet processing part gradually loses even with the increase of processing depth. The machining capacity will also show more tendency to deflect outwards (the phenomenon of outward deflection will occur when the feed rate is too large, which will have a negative impact on the machining quality, such as the advance of the rough cutting area). Abrasive water jet finishing can effectively remove the reserved machining allowance, and the abrasive water jet light cutting can continuously reduce the striped area at the bottom of the incision sidewall, reduce the incision taper and the higher surface roughness at the bottom of the incision sidewall, and finally achieve Abrasive water jet machining with high dimensional and geometric accuracy for near damage-free surfaces.

Compared with single processing, abrasive water jet finishing and smooth cutting can use lower water pressure, abrasive flow and higher feed rate, even in the process of cutting large-thickness composite materials. It still has higher efficiency than single machining under the same cut quality. In fact, due to the energy consumption of abrasive water jet 1 during the processing of large-thickness materials, the same surface as abrasive water jet light cutting and finishing must be achieved by reducing the feed speed in one processing with other parameters being the same. The quality is only a theoretical possibility, because too low feed rates are difficult to apply in practical machining.

Abrasive water jet finishing, light cutting and their combination can be used not only to remove the striped area of the sidewall of the incision after the material has been processed with a large margin, to increase the depth of the smooth area to below the material thickness, and to reduce the incision taper and surface roughness; it can also be used In order to remove the inherent defects on the surface of the material and the processing defects caused by other processing methods, the abrasive water jet processing with high dimensional and geometric accuracy can be achieved near damage-free surfaces.

Abrasive water jet finishing, light cutting and their combination can be used not only for cutting various materials, but also for drilling, turning and forming of convex surfaces.

The present invention is not limited to this embodiment, and any equivalent ideas or changes within the technical scope disclosed in the present invention are included in the protection scope of the present invention.

Claims (1)

1. a polymer-based composite material thick plate abrasive water jet finishing method, is characterized in that: comprise the following steps: A. Select the processing plan according to the first processing method of the workpiece to be processed If the workpiece to be processed adopts abrasive water jet processing for the first time, then go to step B; otherwise, go to step C; B. Select the processing plan according to the shape of the incision of the workpiece to be processed If there are machining accuracy requirements for both sides of the incision, that is, both sides of the incision need to be retained for processing, go to step B1; if there are machining accuracy requirements for only one side incision, that is, only one incision is required for processing, and the other side incision is required. If there is no processing requirement as excess material, go to step B2; B1, bilateral incision processing B11. Reserved finishing allowance Reserve the finishing allowance according to the material properties, size and shape and position accuracy of the workpiece; determine the cutting path; Among them, the calculation formula of reserved finishing allowance is:

Then the actual processing size is:

where: _{γReservation} and γ are the predicted top width of one-half notch and the actual one-half top width of the notch, respectively; εj _reserved and εj are the component of the predicted _jth finishing feed along the vertical direction of the tangent direction of the previous machining track and the actual jth finishing feed along the tangent of the last machining track. The component in the vertical direction of the direction, j∈[1,+∞); ε _j ∈ [0,2r), r is the jet radius, when ε _j = 0, there is no advance along the vertical direction of the tangential direction of the previous machining track. The given amount is regarded as not to perform finishing; m is the number of finishing operations, m∈[1,+∞);

and

are the predicted removal amount of the i-th group of light-cutting processing on the top plane of the material and the actual removal amount of the i-th group of light-cutting processing on the top plane of the material; x _i is the number of consecutive light-cutting operations of the i-th group of light-cutting processing, x _i ∈ [0,+∞); n is the number of light cutting groups, n∈[1,+∞); _{ΔReservation} and Δ are respectively the accumulated error amount in the predicted machining process and the accumulated error amount in the actual machining process; B12, rough machining According to the determined machining path, the abrasive water jet machining is carried out at the feed speed of k ₀ v ₀ , and the bilateral incision with the top width of 2γ is machined; k ₀ ≥1; v ₀ is the same parameter machining in the conventional machining method, and the machining quality The highest feed speed within the specified range of conventional processing methods; v ₀ ≤ v _separation , k ₀ v ₀ ≤ v _separation ; v _separation is the highest speed that cuts the material without causing delamination defects; B13, light cutting Abrasive water jet light cutting is performed along the original machining track at the feed speed of k ₂ v ₀ , that is, no feed machining is performed along the original track; k ₂ ≥1; B14. Selection of processing method Select the processing method. If the notch accuracy reaches the specified machining accuracy or there is no excess material to be removed by continuing the no-feed processing, the processing stops. At this time, the width of the notch top is wide.

Otherwise, go to step B13; B2, unilateral incision processing B21. Reserved finishing allowance Reserve the finishing allowance according to the material properties, size and shape and position accuracy of the workpiece; determine the cutting path; Among them, the calculation formula of reserved finishing allowance is:

Then the actual processing size is:

B22, rough machining Carry out abrasive water jet machining at the feed speed of k ₀ v ₀ according to the determined machining track, and after machining the bilateral incision, keep the incision side in the original position with machining accuracy requirements; B23. Selection of processing method Select the processing method, if the dimensional accuracy is

Or the shape and position accuracy and surface quality cannot meet the specified requirements through no-feed machining, go to step B24; otherwise, go to step B26; B24, finishing machining Abrasive water jet fine-cutting is performed on the workpiece, that is, after the feed amount along the vertical direction of the tangential direction of a machining track on the abrasive water jet is not more than one time the diameter of the jet, the amount of feed is k ₁ v ₀ . The feed speed is used for processing along the parallel direction of the previous processing track of the abrasive water jet; k ₁ ≥ 1; B25. Selection of processing method Select the processing method, if the notch precision reaches the specified processing precision, the processing stops; otherwise, turn to step B26; B26, light cutting Abrasive water jet optical cutting is performed along the last machining track, that is, no feed machining is performed along the last machining track at a feed speed of k ₂ v ₀ ; B27. Selection of processing method Select the processing method. If the machining accuracy of the incision meets the specified requirements, the processing will stop; if the incision accuracy does not meet the specified requirements, select the steps according to the machining conditions of the part: if the non-feed machining continues, there is still excess material to be removed, that is, the size In terms of accuracy, the following formula is satisfied:

Or the shape and position accuracy and surface quality do not meet the specified requirements, go to step B26; if the workpiece reaches the specified shape and position accuracy or continues to perform no-feed machining, there is no excess material to be removed, and the dimensional accuracy has not yet been reached, that is, the dimensional accuracy meets the following requirements. Mode:

Or the shape and position accuracy and surface quality of the workpiece cannot meet the specified requirements through no-feed machining, and turn to step B24; In the formula, x is the number of times of fine cutting, x≥1; y is the number of groups that have been cut, y≥1; C. Follow-up processing of other processing methods C1. Reserve finishing allowance Reserve the finishing allowance according to the material properties, size and shape and position accuracy of the workpiece; determine the cutting path; Among them, the calculation method of reserved finishing allowance is:

Then the actual processing size is:

C2, rough machining According to the machining method or other special processing method, the unilateral or bilateral incision is processed; C3, fine cutting The abrasive water jet fine cutting is performed on the side with machining accuracy requirements, that is, after the feed amount in the vertical direction of the tangential direction of the original machining boundary does not exceed one time of the jet diameter; with k ₁ v ₀ The feed speed is used for processing along the parallel direction of the original processing boundary; C4, processing method selection Select the processing method, if the cutting precision reaches the specified processing precision, the processing stops; otherwise, turn to step C5; C5, light cutting Abrasive water jet optical cutting is performed along the previous processing track, that is, no feed processing is performed along the previous processing track at a feed speed of k ₂ v ₀ ; C6. Selection of processing method Select the processing method. If the machining accuracy of the incision meets the specified requirements, the processing will stop; if the incision accuracy does not meet the specified requirements, select it according to the machining conditions of the parts: if the non-feed machining continues, there is still excess material to be removed, that is, in the dimensional accuracy. The aspect satisfies the following formula:

Or the shape and position accuracy and surface quality do not meet the specified requirements, go to step C5; if the workpiece reaches the specified shape and position accuracy or continues to perform no-feed processing, there is no excess material to be removed, and the dimensional accuracy has not yet been reached, that is, the dimensional accuracy meets the following requirements. Mode:

Or the shape and position accuracy and surface quality of the workpiece cannot meet the specified requirements through no-feed machining, and turn to step C3; x is the number of times of fine cutting, x≥1; y is the number of groups that have been cut, y≥1.

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