Method for predicting and adjusting wire cutting and wire cutting machine

Abstract

The application relates to a cutting method for predicting and adjusting a wire bow and a wire cutting machine, and relates to the technical field of finishing equipment.The cutting method for predicting and adjusting the wire bow can predict the wire bow arc length and the wire bow arc length change amount through the physical parameter change of a tension mechanism by establishing a functional relationship between the wire bow arc length or the wire bow arc length change amount and the physical parameters of the tension mechanism, and then can adjust the feeding speed or the wire speed, so that the wire bow arc length is reduced or increased to achieve the best cutting condition.Therefore, the detection of the wire parameters in the cutting area is no longer time-consuming and laborious, and the wire bow arc length and the wire bow arc length change amount obtained are more accurate because the calculation method of the approximate equivalent to the hypotenuse of a triangle is not used, but the calculation is based on the geometric model of the tension mechanism.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of finishing equipment, in particular to a cutting method for predicting and adjusting wire bow and a wire cutting machine. BACKGROUND

[0002] In the process of cutting by using cutting wire, wire bow is generated in the cutting feed direction due to the resistance of the cutting wire to the workpiece being cut. Excessive wire bow will affect the cutting quality and efficiency. Because the wire bow is too large, the wire marks on the cutting surface will be more obvious, and the large wire bow will increase the cutting wire loss, thereby reducing the cutting ability of the cutting wire, increasing the cutting time, and even the excessive wire bow will cause wire breakage. Therefore, the size of the wire bow directly affects the cutting quality and efficiency, and is one of the important parameters in the cutting process.

[0003] In the process of cutting silicon by using cutting wire, the cutting area is sprayed with cutting fluid, and the generated silicon powder causes the environmental conditions of the entire cutting area to be poor. At the same time, the high-speed wire cutting limits the detection means of the wire bow, and detection is difficult. At present, the online detection of the wire bow is mainly based on the measurement of the wire bow angle, so there are certain difficulties in measurement. In the process of calculating the wire bow height according to the wire bow angle and the equipment parameters, the wire bow arc is approximately equivalent to the hypotenuse of a triangle for calculation. However, in fact, the wire bow arc inside the workpiece is in the form of an asymmetric circular arc, so the wire bow calculated by the equivalent triangle method of the wire bow angle is not accurate enough. SUMMARY

[0004] The present application provides a cutting method for predicting and adjusting wire bow and a wire cutting machine, which is used to at least solve one of the above technical problems.

[0005] According to a first aspect of the present application, the present application provides a cutting method for predicting and adjusting wire bow, which is applied to a wire cutting machine including a tension mechanism, and includes the following operation steps:

[0006] Based on the geometric model of the tension mechanism, a function relationship between the wire bow arc length or the wire bow arc length change and the physical parameters of the tension mechanism is established;

[0007] According to the function relationship, the current wire bow arc length is obtained;

[0008] According to the obtained current wire bow arc length, the feed speed or the wire speed of the cutting wire is adjusted so that the wire bow arc length is within the range of the preset wire bow arc length.

[0009] By establishing a function relationship between the wire bow arc length or the wire bow arc length change amount and the physical parameters of the tension mechanism, the wire bow arc length can be obtained according to the physical parameters of the tension mechanism, so that the wire bow arc length can be adjusted in time, and the wire bow arc length can be maintained at a predetermined wire bow condition during cutting, so that a better cooling and lubricating effect, a smaller wire mark on a cutting surface and a good cutting quality can be obtained. When cutting is performed by using a smaller wire bow arc length, the loss of the cutting wire is reduced, the cutting capacity and the use time of the cutting wire can be prolonged, and the wire breakage caused by a too large wire bow can be prevented.

[0010] Further optimization of the technical scheme of the present application is that the tension mechanism is a linear guide rail type tension mechanism, and the physical parameters of the tension mechanism include the displacement of the weight. According to the above function relationship, the wire bow arc length and the wire bow arc length change amount can be predicted through the change of the weight displacement, and then the feed speed or the wire speed can be adjusted.

[0011] Further optimization of the technical scheme of the present application is that according to a geometric model of the tension mechanism, a predicted wire bow geometric model is formed through the position relationship of the tension wheel, the guide wheel, the first cutting wheel and the second cutting wheel in the wire cutting machine, and a function relationship between the wire bow arc length and the physical parameters of the tension mechanism is obtained as follows:

[0012]

[0013] In the formula, l is the wire bow arc length;

[0014] H is the displacement of the weight;

[0015] F is the tension of the cutting wire;

[0016] L is the length of the cutting wire before stretching;

[0017] E is the elastic modulus of the cutting wire;

[0018] A is the cross-sectional area of the cutting wire;

[0019] d is the diameter of the tension wheel;

[0020] α is the included angle between the linear guide rail and the horizontal direction;

[0021] x0 is the horizontal coordinate of the center point of the tension wheel after moving when the tension of the cutting wire reaches a preset value before cutting starts;

[0022] L1 is the length of one of the short sides of a rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel;

[0023] L2 is the length of one of the long sides of the rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel;

[0024] L3 is the length of the other short side of the rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel.

[0025] Further optimization of the technical solution of the application, when the tension on the cutting line reaches the preset value, the abscissa x0 of the center point of the tension wheel satisfies the following relationship:

[0026]

[0027]

[0028] (L2-x0) 2 +y0 2 =L 20 2 ;

[0029] Wherein, y0 is the ordinate of the center point of the tension wheel when the tension on the cutting line reaches the preset value;

[0030] L 10 is the distance between the center point of the tension wheel after moving and the center point of the first cutting wheel;

[0031] L 20 is the distance between the center point of the tension wheel after moving and the center point of the guide wheel.

[0032] Further optimization of the technical solution of the application, the tension mechanism is a swing lever type tension mechanism, and the physical parameters of the tension mechanism include the displacement of the weight, the position of the tension swing lever and the position of the tension connecting rod. According to the above function relationship, the line bow arc length and the line bow arc length change can be predicted by the change of the weight displacement, and then the feed speed or linear speed can be adjusted.

[0033] Further optimization of the technical solution of the application, according to the geometric model of the tension mechanism, the prediction line bow geometric model is formed by the position relationship of the tension wheel, the guide wheel, the first cutting wheel and the second cutting wheel in the wire cutting machine, and the function relationship between the line bow arc length and the physical parameters of the tension mechanism is obtained as follows:

[0034]

[0035] Wherein, Or

[0036] The function relationship between the line bow arc length and the physical parameters of the tension mechanism is:

[0037]

[0038] Wherein,

[0039] Wherein, F is the tension of the cutting line;

[0040] H is the displacement of the weight;

[0041] L is the length of the cutting line before stretching;

[0042] E is the elastic modulus of the cutting line;

[0043] A is the cross-sectional area of the cutting line;

[0044] L1 is the length of one of the short sides of the rectangle formed by the center points of the first cutting wheel, the second cutting wheel and the guide wheel;

[0045] L2 is the length of one of the long sides of the rectangle formed by the center points of the first cutting wheel, the second cutting wheel and the guide wheel;

[0046] L3 is the length of the other short side of the rectangle formed by the center points of the first cutting wheel, the second cutting wheel and the guide wheel;

[0047] α0 is the angle between the tension swing lever and the horizontal direction when the tension on the cutting line reaches the set tension;

[0048] a is the horizontal coordinate of the center point where the tension swing lever and the tension connecting rod are connected,

[0049] b is the vertical coordinate of the center point where the tension swing lever and the tension connecting rod are connected;

[0050] r is the radius of the tension swing lever;

[0051] R is the radius of the tension connecting rod.

[0052] Further optimization of the technical solution of the application, the tension mechanism is a swing lever type tension mechanism, and the physical parameters of the tension mechanism include the displacement of the weight and the position of the tension swing lever.

[0053] Further optimization of the technical solution of the application, according to the geometric model of the tension mechanism, through the position relationship of the tension wheel, the guide wheel, the first cutting wheel and the second cutting wheel in the wire cutting machine, a predicted wire bow geometric model is formed, and a function relationship between the wire bow arc length and the physical parameters of the tension mechanism is obtained as follows:

[0054]

[0055] wherein, F is the tension of the cutting line;

[0056] H is the displacement of the weight;

[0057] L is the length of the cutting line before stretching;

[0058] E is the elastic modulus of the cutting line;

[0059] A is the cross-sectional area of the cutting line;

[0060] L1 is the length of one of the short sides of the rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel;

[0061] L2 is the length of one of the long sides of the rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel;

[0062] α0 is the angle between the tension pendulum and the horizontal direction when the weight of the adjustment weight of the ring-shaped cutting line is adjusted to make the tension on the cutting line reach the preset value;

[0063] α is the rotation angle of the tension pendulum during cutting, and α is negative when the tension pendulum rotates clockwise, and α is positive when the tension pendulum rotates counterclockwise;

[0064] a is the horizontal coordinate of the center point where the tension pendulum and the tension connecting rod are connected,

[0065] b is the vertical coordinate of the center point where the tension pendulum and the tension connecting rod are connected;

[0066] r is the radius of the tension pendulum.

[0067] Further optimization of the technical scheme of the application adjusts the feeding speed or the linear speed of the cutting line according to the obtained current wire bow arc length, so that the wire bow arc length is within the preset wire bow arc length range, including the following sub-steps:

[0068] S311: determining whether the current wire bow arc length is within the preset wire bow arc length range, if yes, executing S312; if no, executing S313;

[0069] S312: continuing cutting;

[0070] S313: adjusting the feeding speed or the linear speed of the cutting line, and repeating step S311 until cutting is completed.

[0071] Further optimization of the technical scheme of the application adjusts the feeding speed or the linear speed of the cutting line according to the obtained current wire bow arc length, so that the wire bow arc length is within the preset wire bow arc length range, including the following sub-steps:

[0072] S321: determining whether the current wire bow arc length is less than or equal to the preset wire bow arc length, if yes, executing S322; if no, executing S323;

[0073] S322: continuing cutting.

[0074] S323: adjust the feeding speed or the linear speed of the cutting line, and repeat step S311 until the cutting is completed. Further optimization of the technical scheme of the present application, the line bow arc length change amount Δl satisfies the following relationship:

[0075] Δl = l - L4;

[0076] Wherein, L4 is the distance between the center point of the first cutting wheel and the center point of the second cutting wheel.

[0077] According to the second aspect of the present application, the present application provides a wire cutting machine for realizing the cutting method of predicting and adjusting the line bow as described above, comprising a tension mechanism.

[0078] Further optimization of the technical scheme of the present application, the wire cutting machine further comprises a cutting mechanism, the cutting mechanism comprises a tension wheel, a guide wheel, a first cutting wheel, a second cutting wheel and a cutting line, the centers of the guide wheel, the first cutting wheel and the second cutting wheel are respectively at the four vertices of a rectangle; the cutting line passes through the tension wheel, the first cutting wheel, the second cutting wheel and the guide wheel in turn to form a circular cutting line cutting system, wherein the tension mechanism is connected with the tension wheel.

[0079] Compared with the prior art, the present application has the advantages that: by establishing the functional relationship between the line bow arc length or the line bow arc length change amount and the physical parameters of the tension mechanism, the line bow arc length and the line bow arc length change amount are predicted by the change of the physical parameters of the tension mechanism, and then the feeding speed or the linear speed can be adjusted to reduce or increase the line bow arc length to achieve the best cutting condition. Therefore, it is not necessary to detect the cutting area line parameters again, and since the calculation method of the approximate equivalent of the triangle hypotenuse is not used, but the calculation is based on the geometric model of the tension mechanism, the line bow arc length and the line bow arc length change amount obtained are more accurate. BRIEF DESCRIPTION OF DRAWINGS

[0080] In the following, the present application will be described in more detail based on embodiments and with reference to the accompanying drawings.

[0081] Figure 1 is a cutting area line length change schematic diagram in the embodiment of the present application;

[0082] Figure 2 is a prediction line bow geometric model established when the tension mechanism is a linear tension mechanism in the embodiment of the present application;

[0083] Figure 3 is a prediction line bow geometric model established when the tension mechanism is a swing lever type tension mechanism in the embodiment of the present application;

[0084] Figure 4 Flowchart of the cutting method of predicting and adjusting the line bow in the embodiment of the present application.

[0085] Reference signs:

[0086] 11-tension wheel; 12-guide wheel; 13-first cutting wheel; 14-second cutting wheel;

[0087] 21-weight; 22-tension swing lever; 23-tension connecting rod;

[0088] 31-workpiece. DETAILED DESCRIPTION

[0089] The present application will be further described below with reference to the accompanying drawings.

[0090] According to the first aspect of the present application, the present application provides a cutting method for predicting and adjusting wire bow, which uses a ring-shaped cutting wire as a cutting tool to remove material. The wire bow arc length is defined as the length of the cutting wire caused by the change of the cutting zone from a straight line to an arc line when the cutting wire is blocked during the cutting process, and the length of the cutting wire from the workpiece to the cutting wheel at this time. The change of the length of the cutting zone caused by the arc length is defined as the change of the wire bow arc length, as shown in the formula: Figure 1 In the present application, the cutting wire can be a diamond wire, and the ring-shaped cutting wire can be a ring-shaped diamond wire.

[0091] The cutting method for predicting and adjusting wire bow of the present application can calculate the current wire bow arc length by establishing a function of the wire bow arc length, compare it with the preset wire bow arc length, and adjust the feed speed or the wire speed of the cutting wire, so that the wire bow can be reduced or increased, thereby achieving the best cutting condition.

[0092] Example 1

[0093] The cutting method for predicting and adjusting wire bow of the present application is applied to a wire cutting machine, which can include a tension mechanism, and includes the following operation steps:

[0094] S1: based on the geometric model of the tension mechanism, a function relationship between the wire bow arc length or the change of the wire bow arc length and the physical parameters of the tension mechanism is established. The tension mechanism is a linear guide rail type tension mechanism, and the physical parameters of the tension mechanism include the displacement H of the weight 21.

[0095] As shown in the formula: Figure 2 The center points of the guide wheel 12, the first cutting wheel 13 and the second cutting wheel 14 of the wire cutting machine are respectively at three vertices of a rectangle (as shown by the dotted line in Figure 2 ), and the other vertex of the rectangle is Figure 2A point. Wherein, the guide wheel 12 is above the second cutting wheel 14, and the center points of the two are on the same vertical line, and the center points of the first cutting wheel 13 and the second cutting wheel 14 are on the same horizontal line; in addition, the point on the same vertical line with the center point of the first cutting wheel 13 and on the same horizontal line with the center point of the guide wheel 12 is the A point. Therefore, connecting the A point, the center point of the guide wheel 12, the center point of the second cutting wheel 14 and the center point of the first cutting wheel 13 in turn can form a rectangle (as shown by the dotted line in Figure 2 FIG. 2).

[0096] The initial position of the center of the tension wheel 11 of the wire cutting machine can be at the A point as shown, or can not be at the A point as shown. Figure 2 Figure 2 The cutting wire (diamond wire) is wound on the outer wall of the tension wheel 11, the guide wheel 12, the first cutting wheel 13 and the second cutting wheel 14 in turn to form a ring-shaped cutting wire cutting system. Wherein, the positional relationship of the tension wheel 11, the guide wheel 12, the first cutting wheel 13 and the second cutting wheel 14 can form a predicted wire bow geometric model.

[0097] In the process of cutting the workpiece 31, the cutting wire (specifically, the cutting wire between the first cutting wheel 13 and the second cutting wheel 14) is subjected to the workpiece resistance to generate a wire bow, causing the tension wheel 11 to move in the straight guide rail (for example, the center of the tension wheel 11 moves from the initial position to the B point), thereby driving the weight 21 connected to the tension wheel 11 to move, that is, the weight 21 generates a displacement H. Therefore, by establishing a functional relationship between the wire bow arc length and the displacement of the weight 21, the wire bow arc length and the change of the wire bow arc length caused by the wire bow can be obtained according to the displacement of the weight 21.

[0098] Specifically, based on the fixed length of the ring wire in the natural state, the process of the cutting wire being elongated by tension in the cutting movement process is similar to the axial stretching in the material mechanics, and satisfies the Hook's law. Therefore, a coordinate system is established with one vertex A (0, 0) of the above-mentioned rectangle as the origin. After the ring-shaped cutting wire cutting system is formed, the weight of the weight 21 is adjusted, so that the tension on the cutting wire reaches the set tension, and then the center point of the tension wheel 11 moves to the point B, and the coordinates of the point B are (x0, y0), at this time the cutting is started. Therefore, x0 is the horizontal coordinate of the center point of the tension wheel after the tension wheel moves when the tension on the cutting wire reaches the preset value before the cutting starts, which can be a constant and can be obtained by calculation through the following relationship formulas (1-2), (1-3), (1-4), (1-5).

[0099] In the cutting process, the cutting wire bow is generated, causing the weight 21 to move up and down, and the functional relationship between the wire bow arc length l and the displacement H of the weight 21 is as follows:

[0100] ​

[0101] Wherein, F is the tension of the cutting line; L is the length of the cutting line before stretching; E is the elastic modulus of the cutting line; A is the cross-sectional area of the cutting line; d is the diameter of the tension wheel 11; and a is the included angle between the linear guide rail and the horizontal direction.

[0102] As shown in Figure 2 L1 is the length of one of the short sides of the rectangle formed by the center point of the first cutting wheel 13, the center point of the second cutting wheel 14, and the center point of the guide wheel 12; L2 is the length of one of the long sides of the rectangle formed by the center point of the first cutting wheel 13, the center point of the second cutting wheel 14, and the center point of the guide wheel 12; and L3 is the length of the other short side of the rectangle formed by the center point of the first cutting wheel 13, the center point of the second cutting wheel 14, and the center point of the guide wheel 12. Wherein, L1 can be equal to L3, and L2 can be equal to the distance between the center point of the first cutting wheel 13 and the center point of the second cutting wheel 14, i.e. L4.

[0103] Wherein, the displacement H of the weight 21 can be obtained by the displacement sensor, and thus the abscissa x0 of the center point of the tension wheel 11 can be calculated to obtain the line arc length l through the above function relationship (1-1).

[0104] When the tension on the cutting line reaches the preset value, the abscissa x0 of the center point of the tension wheel 11 satisfies the following relationship:

[0105]

[0106] x0 2 +(y0+L1) 2 =L 10 2 (1-3)

[0107] (L2-x0) 2 +y0 2 =L 20 2 (1-4)

[0108] L 10 +L 20 =n (1-5)

[0109] By simultaneously solving the above relationship (1-2), (1-3), (1-4), (1-5), the value of x0 can be obtained, i.e.:

[0110]

[0111] Wherein, a = (2L1tan a + 2L2) 2 -4n 2 [1+(tan a) 2];

[0112] b = 8n 2 L2-4(L1tanα+L2)(n 2 +L2 2 -L1 2 );

[0113] c = (n 2 +L2 2 -L1 2 ) 2 -4n 2 L2 2 ;

[0114]

[0115] As Figure 2 shown, L 10 is the distance between the center point of the tension wheel 11 after movement and the center point of the first cutting wheel 13; L 20 is the distance between the center point of the tension wheel 11 after movement and the center point of the guide wheel 12.

[0116] Therefore, according to the inherent parameters (L1, L2, L3, L4, L 10 , L 20 , F, L, E, A, d, α) of the device, the unique solution of the horizontal coordinate x0 of the center point of the tension wheel 11 when the tension on the cutting line reaches the preset value can be determined, so that the line bow arc length l can be obtained according to the displacement H of the weight 21.

[0117] In addition, the line bow arc length change amount Δl satisfies the following relationship:

[0118] Δl = l - L4;

[0119] Wherein, L4 is the distance between the center point of the first cutting wheel 13 and the center point of the second cutting wheel 14.

[0120] Therefore, the line bow arc length change amount Δl can be obtained according to the line bow arc length l.

[0121] S2: Obtain the current line bow arc length according to the above function relationship (1-1).

[0122] S3: Adjust the feed speed of the workpiece 31 or the linear speed of the cutting line according to the obtained current line bow arc length, so that the line bow arc length is within the range of the preset line bow arc length.

[0123] In an optional embodiment, the method of real-time adjustment is adopted to adjust the feed speed of the workpiece 31 or the linear speed of the cutting line in step S3.

[0124] Specifically, as Figure 4As shown, step S3 includes the following sub-steps.

[0125] S311: judging whether the current wire bow arc length is within the range of the preset wire bow arc length, if yes, executing S312; if no, executing S313.

[0126] S312: continuing cutting.

[0127] S313: increasing or decreasing the feed speed (or increasing or decreasing the wire speed of the cutting wire), and repeating step S311 until the cutting is completed.

[0128] In the above embodiment, the current wire bow arc length is within the range of the preset wire bow arc length, which means that the current wire bow arc length is equal to a fixed value or the current wire bow arc length does not exceed a certain range.

[0129] Therefore, by the real-time adjustment method, the feed speed of the workpiece 31 or the wire speed of the cutting wire can be adjusted in real time according to the change of the wire bow arc length during the cutting process, so that the wire bow arc length is always maintained at the reference value. When the cutting is performed with the wire bow arc length always maintained at the reference value, the cooling and lubrication effect is better, the cutting wire mark is small, and better cutting quality can be obtained. In addition, the wire bow is smaller, the cutting wire loss is reduced, the cutting ability and use time of the cutting wire can be prolonged, and the situation that the wire bow is too large to cause the cutting wire to break can be prevented.

[0130] In an optional embodiment, a stage adjustment method is adopted in step S3 to adjust the feed speed of the workpiece 31 or the wire speed of the cutting wire. The feed speed refers to the moving speed of the cutting wire in the feed direction driven by the first cutting wheel 13 and the second cutting wheel 14.

[0131] Specifically, as shown in FIG. 4, step S3 includes the following sub-steps. Figure 4

[0132] S321: judging whether the current wire bow arc length is less than or equal to the preset wire bow arc length, if yes, executing S322; if no, executing S323.

[0133] S322: continuing cutting.

[0134] S323: adjusting the feed speed or the wire speed of the cutting wire, and repeating step S311 until the cutting is completed.

[0135] Therefore, by the stage adjustment method, when the change of the wire bow arc length does not exceed the predetermined range, the current feed and wire speed conditions are maintained to continue cutting; when the change of the wire bow arc length exceeds the range, the feed speed or the wire speed of the cutting wire needs to be adjusted (for example, the feed speed is decreased or the wire speed of the cutting wire is increased) to make the wire bow arc length return to the predetermined range, so that the cutting process is maintained under the condition of the predetermined wire bow arc length for cutting.​

[0136] Example 2

[0137] The cutting method of the prediction and adjustment wire bow of the present application comprises the following operation steps:

[0138] S1: Based on the geometric model of the tension mechanism, a function relationship between the arc length of the wire bow or the change amount of the arc length of the wire bow and the physical parameters of the tension mechanism is established. The tension mechanism is a swing rod type tension mechanism, and the physical parameters of the tension mechanism include the displacement H of the weight 21, the position of the tension swing rod 22, and the position of the tension connecting rod 23. The position of the tension swing rod 22 may, for example, be the radius r of the tension swing rod 22, the horizontal coordinate a and the vertical coordinate b of the center point connected by the tension swing rod 22 and the tension connecting rod 23. The position of the tension connecting rod 23 may, for example, be the radius R of the tension connecting rod 23.

[0139] As shown in Figure 3 , the center points of the guide wheel 12, the first cutting wheel 13 and the second cutting wheel 14 of the wire cutting machine are respectively located at three vertices of a rectangle (as shown by the dashed line in Figure 3 ), and the other vertex of the rectangle is point A shown in Figure 3 . Among them, the guide wheel 12 is located above the second cutting wheel 14, and the center points of the two are located on the same vertical line, and the center points of the first cutting wheel 13 and the second cutting wheel 14 are located on the same horizontal line; in addition, the point A is located on the same vertical line as the center point of the first cutting wheel 13, and on the same horizontal line as the center point of the guide wheel 12. Therefore, sequentially connecting the A point, the center point of the guide wheel 12, the center point of the second cutting wheel 14 and the center point of the first cutting wheel 13 can form a rectangle (as shown by the dashed line in Figure 3 ).

[0140] The initial position of the center of the tension wheel 11 of the wire cutting machine can be at point A shown in Figure 3 , or not at point A shown in Figure 3 . The cutting wire (diamond wire) is wound on the outer wall of the tension wheel 11, the guide wheel 12, the first cutting wheel 13 and the second cutting wheel 14 in sequence to form a ring-shaped cutting wire cutting system. Among them, the positional relationship of the tension wheel 11, the guide wheel 12, the first cutting wheel 13 and the second cutting wheel 14 can form a prediction wire bow geometric model.

[0141] In the process of cutting the workpiece 31, the cutting wire (specifically, the cutting wire between the first cutting wheel 13 and the second cutting wheel 14) is subjected to the action of the workpiece resistance to generate a wire bow, which causes the tension wheel 11 to swing (for example, from Figure 2As shown, the tension wheel 11 swings from point A to point B, thereby moving the weight 21 connected to the tension wheel 11. This means that the weight 21 generates a displacement H. Therefore, by establishing a functional relationship between the arc length of the wire bow and the displacement of the weight 21, the arc length of the wire bow and the change in arc length caused by the wire bow can be obtained based on the displacement of the weight 21.

[0142] A coordinate system is established with A(0,0), one vertex of the rectangle, as the origin. After forming a circular cutting wire cutting system, the weight 21 is adjusted so that the tension on the wire reaches the preset value. The center point of the tension wheel 11 swings to point B, with the coordinates of point B being (x0, y0). At this point, cutting begins. During the cutting process, a cutting wire bow is generated, causing the weight 21 to swing. The coordinates of the center point O where the tension pendulum 22 and the tension link 23 are connected are (a, b). The functional relationship of the wire bow arc length l can be obtained as follows:

[0143]

[0144] in: Then take "+"; Then take “-”.

[0145] In other words, if The functional relationship of the arc length l is the following relationship (2-2):

[0146]

[0147] like Then the functional relationship of the arc length l is the following relationship (2-3):

[0148]

[0149] Where F is the tension of the cutting line; H is the displacement of the weight; L is the length of the cutting line before stretching; E is the elastic modulus of the cutting line; and A is the cross-sectional area of ​​the cutting line.

[0150] like Figure 3 As shown, L1 is the length of one short side of the rectangle formed by the center points of the first cutting wheel 13, the second cutting wheel 14, and the guide wheel 12; L2 is the length of one long side of the rectangle formed by the center points of the first cutting wheel 13, the second cutting wheel 14, and the guide wheel 12; and L3 is the length of the other short side of the rectangle formed by the center points of the first cutting wheel 13, the second cutting wheel 14, and the guide wheel 12. L1 can be equal to L3, and L2 can be equal to the distance between the center points of the first cutting wheel 13 and the second cutting wheel 14, i.e., L4.

[0151] a0 is the angle between the tension swing rod 22 and the horizontal direction after the tension reaches the set tension on the cutting line, which can be calculated by the inherent parameters of the device and the tension value.

[0152] r is the radius of the tension swing rod 22, that is, Figure 3 the length of the middle segment OB; R is the radius of the tension connecting rod 23.

[0153] The displacement H of the weight 21 can be obtained by the displacement sensor, and therefore, the wire bow arc length l can be obtained according to the inherent parameters (L1, L2, L3, L4, F, L, E, A, a0, r, R) of the device.

[0154] In addition, the wire bow arc length change amount Dl satisfies the following relationship:

[0155] Dl = l - L4;

[0156] wherein L4 is the distance between the center point of the first cutting wheel 13 and the center point of the second cutting wheel 14.

[0157] Therefore, the wire bow arc length change amount Dl can be obtained according to the wire bow arc length l.

[0158] S2: obtaining the current wire bow arc length according to the above function relationship (2-1).

[0159] S3: adjusting the feed speed of the workpiece 31 or the wire speed of the cutting wire according to the obtained current wire bow arc length, so that the wire bow arc length is within the range of the preset wire bow arc length. The feed speed refers to the moving speed of the cutting wire in the feed direction driven by the first cutting wheel 13 and the second cutting wheel 14.

[0160] In an optional embodiment, a real-time adjustment method is adopted in step S3 to adjust the feed speed of the workpiece 31 or the wire speed of the cutting wire.

[0161] Specifically, as shown in Figure 4 step S3 includes the following sub-steps.

[0162] S311: judging whether the current wire bow arc length is within the range of the preset wire bow arc length, if yes, executing S312; if no, executing S313.

[0163] S312: continuing cutting.

[0164] S313: adjusting the feed speed or the wire speed of the cutting wire (for example, increasing or decreasing the feed speed, increasing or decreasing the wire speed of the cutting wire), and repeating step S311 until the cutting is completed.

[0165] The current wire bow arc length within the range of the preset wire bow arc length can be that the current wire bow arc length is equal to a preset fixed value, or that the current wire bow arc length does not exceed a certain range.

[0166] Therefore, by the method of real-time adjustment, the feeding speed of the workpiece 31 or the wire speed of the cutting wire can be adjusted in real time according to the change of the wire bow arc length during the cutting process, so that the wire bow arc length is always maintained at the reference value. When cutting is performed with the wire bow arc length always maintained at the reference value, the cooling and lubrication effect is better, the cutting wire mark is small, and better cutting quality can be obtained. In addition, the loss of the cutting wire is reduced by setting a smaller wire bow, the cutting capacity and use time of the cutting wire can be prolonged, and the situation of wire breakage caused by too large wire bow can also be prevented.

[0167] In an optional embodiment, the method of stage adjustment is adopted in step S3 to adjust the feeding speed of the workpiece 31 or the wire speed of the cutting wire.

[0168] Specifically, as shown in FIG. 6, step S3 includes the following sub-steps. Figure 4

[0169] S321: It is judged whether the current wire bow arc length is less than or equal to the preset wire bow arc length. If yes, S322 is executed; if no, S323 is executed.

[0170] S322: The cutting is continued.

[0171] S323: The feeding speed or the wire speed of the cutting wire is adjusted, and step S311 is repeated until the cutting is completed.

[0172] Therefore, by the method of stage adjustment, when the change of the wire bow arc length does not exceed the predetermined range, the current feeding and wire speed conditions are maintained to continue the cutting; when the change amount of the wire bow arc length exceeds the range, the feeding speed or the wire speed of the cutting wire needs to be adjusted (for example, the feeding speed is reduced or the wire speed of the cutting wire is increased) to make the wire bow arc length return to the predetermined range, so that the cutting process is maintained under the condition of the predetermined wire bow arc length for cutting.

[0173] Example 3

[0174] In this embodiment 3, the tension mechanism is the same as that in the above-mentioned embodiment 2, i.e., a swing rod type tension mechanism, and the physical parameters of the tension mechanism include the displacement H of the weight 21 and the position of the tension swing rod 22. The position of the tension swing rod 22 may, for example, be the radius r of the tension swing rod 22, the horizontal coordinate a and the vertical coordinate b of the center point connected with the tension swing rod 22 and the tension connecting rod 23.

[0175] Different from the above-mentioned embodiment 2, in this embodiment 3, according to the geometric model of the tension mechanism, the function relationship between the wire bow arc length and the physical parameters of the tension mechanism is obtained through the predicted wire bow geometric model formed by the position relationship of the tension wheel 11, the guide wheel 12, the first cutting wheel 13 and the second cutting wheel 14 in the wire cutting machine, and the function relationship of the wire bow arc length l is:​

[0176]

[0177] Wherein, F is the tension of the cutting line; H is the displacement of the weight; L is the length of the cutting line before stretching; E is the elastic modulus of the cutting line; A is the cross-sectional area of the cutting line.

[0178] L1 is the length of one of the short sides of the rectangle formed by the center point of the first cutting wheel 13, the center point of the second cutting wheel 14 and the center point of the guide wheel 12; L2 is the length of one of the long sides of the rectangle formed by the center point of the first cutting wheel 13, the center point of the second cutting wheel 14 and the center point of the guide wheel 12. Wherein, L1 can be equal to L3, and L2 can be equal to the distance between the center point of the first cutting wheel 13 and the center point of the second cutting wheel 14, i.e. L4.

[0179] α0 is the angle between the tension pendulum 22 and the horizontal direction when the weight of the weight 21 is adjusted to make the tension on the cutting line reach the preset value after the cutting line is hung, and α0 can be calculated by the inherent parameters of the equipment.

[0180] α is the rotation angle of the tension pendulum 22 during cutting, and α is negative when the tension pendulum 22 rotates clockwise, and α is positive when the tension pendulum 22 rotates counterclockwise.

[0181] a is the horizontal coordinate of the center point of the tension pendulum 22, b is the vertical coordinate of the center point of the tension pendulum 22; r is the radius of the tension pendulum 22, i.e. Figure 3 the length of the middle segment OB.

[0182] The same steps as in Embodiment 2 will not be repeated.

[0183] According to the second aspect of the present application, the present application provides a wire cutting machine for realizing the above-mentioned cutting method of the prediction and adjustment of the wire bow, which comprises a cutting mechanism and a tension mechanism. As shown in Figure 2 and Figure 3 The cutting mechanism comprises a tension wheel 11, a guide wheel 12, a first cutting wheel 13, a second cutting wheel 14 and a cutting line. The centers of the guide wheel 12, the first cutting wheel 13 and the second cutting wheel 14 are respectively at three vertices of a rectangle. The cutting line passes through the tension wheel 11, the first cutting wheel 13, the second cutting wheel 14 and the guide wheel 12 in turn to form a circular cutting line cutting system. The tension mechanism is connected with the tension wheel 11 and is used for adjusting the tension of the cutting line. The tension mechanism can be a linear guide type or a pendulum type tension mechanism.

[0184] In addition, the wire cutting machine of the present application further comprises a cutting feeding mechanism (workpiece feeding mechanism), a base for supporting the cutting feeding mechanism, and a column provided on the base for supporting the cutting mechanism.

[0185] When the cutting starts, the driving motor drives the first cutting wheel 13 to rotate, and then drives the annular cutting wire to move at high speed to cut the workpiece.

[0186] The technical features of the present application are described as follows.

[0187] Cutting wire cutting: refers to a processing method for achieving the cutting purpose by using the electroplated cutting wire to remove the material.

[0188] Wire bow arc length: refers to the wire arc length when the cutting wire in the cutting zone changes from a straight line to an arc line due to the resistance in the cutting process, and the length of the cutting wire from the workpiece to the cutting wheel at this time.

[0189] Wire bow: refers to the distance from the wire bow vertex to the cutting edge of the workpiece.

[0190] Wire bow angle: refers to the angle between the cutting wire between the cutting wheel and the workpiece and the horizontal direction.

[0191] Although the present application has been described with reference to the preferred embodiments, various modifications can be made to it without departing from the scope of the present application and equivalent components can be substituted therefor. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method of predicting and adjusting wire cutting, the method of cutting applied to a wire cutting machine, the wire cutting machine comprising a tension mechanism, characterized in that, The method comprises the following steps: a function relationship between the wire bow arc length or the wire bow arc length change amount and the physical parameters of the tension mechanism is established based on a geometric model of the tension mechanism; the current wire bow arc length is obtained according to the function relationship; the feeding speed or the wire speed of the cutting wire is adjusted according to the obtained current wire bow arc length, so that the wire bow arc length is within a preset range of the wire bow arc length; the tension mechanism is a linear guide rail type tension mechanism, and the physical parameters of the tension mechanism include the displacement of the weight; a function relationship between the wire bow arc length and the physical parameters of the tension mechanism is obtained according to a predicted wire bow geometric model formed by the position relationship among the tension wheel, the guide wheel, the first cutting wheel and the second cutting wheel in the wire cutting machine based on a geometric model of the tension mechanism, and the function relationship is as follows: wherein, l is the wire bow arc length; H is the displacement of the weight; F is the tension of the cutting wire; L is the length of the cutting wire before stretching; E is the elastic modulus of the cutting wire; A is the cross-sectional area of the cutting wire; d is the diameter of the tension wheel; α is the included angle between the linear guide rail and the horizontal direction; x0 is the horizontal coordinate of the center point of the tension wheel after moving when the tension of the cutting wire reaches a preset value before cutting starts; L1 is the length of one of the short sides of a rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel; L2 is the length of one of the long sides of the rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel; L3 is the length of the other short side of the rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel.

2. The method of claim 1, wherein, The horizontal coordinate x0 of the center point of the tension wheel when the tension of the cutting wire reaches a preset value satisfies the following relationship: x0 2 + (y0+L1) 2 = L 10 2 ; (L2-x0) 2 +y0 2 = L 20 2 ; wherein, y0 is the vertical coordinate of the center point of the tension wheel when the tension of the cutting wire reaches a preset value; L 10 is the distance between the center point of the tension wheel after moving and the center point of the first cutting wheel; L 20 is the distance between the center point of the tension wheel after the movement and the center point of the guide wheel.

3. A method of predicting and adjusting wire cutting, the method of cutting being applied to a wire cutting machine, the wire cutting machine comprising a tension mechanism, characterized in that, The method comprises the following steps: a function relationship between the wire bow arc length or the wire bow arc length change amount and the physical parameters of the tension mechanism is established based on a geometric model of the tension mechanism; the current wire bow arc length is obtained according to the function relationship; the feeding speed or the wire speed of the cutting wire is adjusted according to the obtained current wire bow arc length, so that the wire bow arc length is within a preset range of the wire bow arc length; the tension mechanism is a linear guide rail type tension mechanism, and the physical parameters of the tension mechanism include the displacement of the weight; a function relationship between the wire bow arc length and the physical parameters of the tension mechanism is obtained according to a predicted wire bow geometric model formed by the position relationship among the tension wheel, the guide wheel, the first cutting wheel and the second cutting wheel in the wire cutting machine based on a geometric model of the tension mechanism, and the function relationship is as follows: wherein or The function relationship between the wire bow arc length and the physical parameters of the tension mechanism is as follows: wherein wherein, F is the tension of the cutting wire; H is the displacement of the weight; L is the length of the cutting wire before stretching; E is the elastic modulus of the cutting wire; A is the cross-sectional area of the cutting wire; L1 is the length of one of the short sides of a rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel; L2 is the length of one of the long sides of the rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel; L3 is the length of the other short side of the rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel. L3 is the length of the other short side of the rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel; α0 is the angle between the tension pendulum and the horizontal direction when the tension on the cutting line reaches the preset tension; a is the horizontal coordinate of the center point where the tension pendulum and the tension connecting rod are connected, b is the vertical coordinate of the center point where the tension pendulum and the tension connecting rod are connected; r is the radius of the tension pendulum; R is the radius of the tension connecting rod.

4. A method of predicting and adjusting wire cutting, the method of cutting being applied to a wire cutting machine, the wire cutting machine comprising a tension mechanism, characterized in that, The method comprises the following operation steps: Based on the geometric model of the tension mechanism, a function relationship between the wire bow arc length or the wire bow arc length change and the physical parameters of the tension mechanism is established; According to the function relationship, the current wire bow arc length is obtained; According to the obtained current wire bow arc length, the feed speed or the linear speed of the cutting line is adjusted so that the wire bow arc length is within the range of the preset wire bow arc length; The tension mechanism is a pendulum type tension mechanism, and the physical parameters of the tension mechanism include the displacement of the weight and the position of the tension pendulum; According to the geometric model of the tension mechanism, the function relationship between the wire bow arc length and the physical parameters of the tension mechanism is obtained through a predicted wire bow geometric model formed by the position relationship of the tension wheel, the guide wheel, the first cutting wheel and the second cutting wheel in the wire cutting machine, and the function relationship is as follows: Wherein, F is the tension of the cutting line; H is the displacement of the weight; L is the length of the cutting line before stretching; E is the elastic modulus of the cutting line; A is the cross-sectional area of the cutting line; L1 is the length of one of the short sides of the rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel; L2 is the length of one of the long sides of the rectangle formed by the center point of the first cutting wheel, the center point of the second cutting wheel and the center point of the guide wheel; α0 is the angle between the tension pendulum and the horizontal direction when the weight of the weight is adjusted to make the tension on the cutting line reach the preset value after the cutting line is hung; α is the rotation angle of the tension pendulum during cutting, and when the tension pendulum rotates clockwise, α is negative, and when the tension pendulum rotates counterclockwise, α is positive; a is the horizontal coordinate of the center point where the tension pendulum and the tension connecting rod are connected, b is the vertical coordinate of the center point where the tension pendulum and the tension connecting rod are connected; r is the radius of the tension pendulum.

5. The method of predicting and adjusting the cut of a wire bow of any of claims 1-4, wherein, According to the obtained current wire bow arc length, the feed speed or the linear speed of the cutting line is adjusted so that the wire bow arc length is within the range of the preset wire bow arc length, which comprises the following sub-steps: S311: Determine whether the current wire bow arc length is within the range of the preset wire bow arc length, if yes, execute S312; if no, execute S313; S312: Continue cutting; S313: Adjust the feed speed or the linear speed of the cutting line, and repeat step S311 until the cutting is completed.

6. The method of predicting and adjusting the cut of a wire bow of any of claims 1-4, wherein, According to the obtained current wire bow arc length, the feed speed or the linear speed of the cutting line is adjusted so that the wire bow arc length is within the range of the preset wire bow arc length, which comprises the following sub-steps: S321: Determine whether the current wire bow arc length is less than or equal to the preset wire bow arc length, if yes, execute S322; if no, execute S323; S322: Continue cutting; S323: Adjust the feed speed or the linear speed of the cutting line, and repeat step S311 until the cutting is completed.

7. The method of predicting and adjusting the cut of a wire bow of any of claims 1-4, wherein, The wire bow arc length change Δl satisfies the following relationship: △l＝l-L4； L4 is the distance between the center point of the first cutting wheel and the center point of the second cutting wheel.

8. A wire cutting machine for implementing the cutting method of the wire arch prediction and adjustment according to any one of claims 1-7, characterized in that, The tension mechanism is included.

9. The wire saw as claimed in claim 8, characterized in that The cutting mechanism is also included, which comprises a tension wheel, a guide wheel, a first cutting wheel, a second cutting wheel and a cutting line. The centers of the guide wheel, the first cutting wheel and the second cutting wheel are respectively at three vertices of a rectangle. The cutting line passes through the tension wheel, the first cutting wheel, the second cutting wheel and the guide wheel in sequence to form a loop cutting line cutting system. The tension mechanism is connected with the tension wheel.

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