Special equipment for measuring electrode blank

Abstract

The utility model discloses special equipment for measuring an electrode blank. The device comprises a loosening and clamping device, an X-axis linear motion assembly, a Y-axis linear motion assembly, a Z-axis linear motion assembly and a support, the support is provided with a detection device, and the detection device comprises a servo motor and a measuring head. The measuring head is of a groove-shaped structure with a downward opening, the upper inner top face of the groove-shaped structure serves as a top datum plane A, the right inner side face of the groove-shaped structure serves as a right datum plane B, meanwhile, the left inner side face of the groove-shaped structure serves as a left datum plane C, and an electrode blank is clamped and fixed through the blank loosening and clamping device and can be measured through the detection device. The measuring device has the advantages that the measuring times are reduced, the efficiency is greatly improved, and particularly, the measuring head with a groove-shaped structure is adopted, so that the measurement of three base surfaces of the measuring head to five surfaces of an electrode is realized; the whole structural design is ingenious, continuous measurement work can be achieved, rapid clamping of the electrode blank can be achieved, and the working efficiency is further improved.

Description

Technical Field

[0001] This utility model relates to an electrical discharge machining (EDM) device, specifically a special device for measuring electrode blanks. Background Technology

[0002] Electrical discharge machining (EDM) is a special machining technology based on the electro-erosion effect. EDM machine tools are the equipment that realizes this technology. Its machining is not affected by the strength, hardness, brittleness, and toughness of the workpiece material. It provides an effective machining means for difficult-to-machine materials such as heat-resistant steel, hardened steel, and cemented carbide. It is mainly used to machine precision parts of complex high-temperature heat-resistant alloys, titanium alloys, aluminum, and other materials in the aerospace field; and molds used for complex automotive parts, plastic parts, castings, forgings, or stampings.

[0003] The cutting tool is the component that performs cutting on a machine tool, while the electrode is the "tool" used in electrical discharge machining (EDM). Its material is typically copper. Electrodes are precision components, and the production process using CNC machine tools involves: clamping – measuring the electrode blank dimensions – precision machining. Therefore, in existing technologies, all three processes are completed on the machine tool.

[0004] The workpiece measurement and positioning problem can be divided into two categories. The first category is the measurement and positioning of batch blanks, and the second category is the measurement and positioning of single blanks. For the positioning problem of simple structure and regular shape blanks in batch production, the technology is relatively mature, and on-machine measurement is mostly used. The measurement and positioning of batch blanks is to determine the machining coordinate system by measuring and positioning the first blank. After subsequent blanks are clamped, the same machining origin is used, and no further measurement and positioning is required. For the measurement and positioning of a single blank, there are usually two methods: external coordinate measuring machine (CMM) and in-machine inspection. In-machine inspection involves directly measuring the position of the blank on the machining center using tools or other inspection equipment. This method requires machine tool uptime, affecting machine tool efficiency, and generally takes 3-5 minutes to complete one inspection. External coordinate measuring machine (CMM) is achieved by using a quick-change fixture and combining it with CMM measurement. The method involves mounting the blank on the CMM using a quick-change fixture system to determine the blank's position relative to the fixture. Then, the blank and fixture are mounted together on the machining center, and the position of the blank on the machining center is determined by the positional relationship between the blank and the fixture. This method reduces the downtime of the machining center, but the measuring equipment is expensive and the operation is complex, so it is currently rarely used in electrode blank measurement.

[0005] A utility model patent authorized in November 2022, with patent number ZL202221592335.3 and titled "A Maximum Solid Dimension Measuring Machine for External Electrode Blanks," specifically discloses a technique for obtaining the maximum solid dimension by detecting the convex points on the five faces of an electrode blank using the five concave base surfaces of a gauge block. The gauge block processing procedure is relatively complex, making it difficult to guarantee processing accuracy. Because the gauge block has a concave, five-sided enclosed structure, when changing the electrode blank, the gauge block needs to be lifted along the Z-axis, and the bottom surface of the gauge block must be higher than the highest point of the workpiece; otherwise, the workpiece cannot be clamped. The main unit of this measuring machine adopts a gantry structure, and the X-axis is driven by two electrodes simultaneously, resulting in poor synchronization accuracy. In addition, the driving device of this measuring machine uses a stepper motor, which generates significant noise, heats up during prolonged operation, and has poor control accuracy. Summary of the Invention

[0006] The technical problem to be solved by this utility model is to provide a special electrode blank measuring device that can quickly measure the external dimensions of blanks instead of machine tools, thereby reducing operator intervention in the digital production process of machine tools, and has high measurement accuracy, low cost and flexible operation.

[0007] To solve the above-mentioned technical problems, the present invention provides a special device for measuring electrode blanks, comprising a clamping device for holding the electrode blank, an X-axis linear motion assembly capable of moving along the X-axis, a Y-axis linear motion assembly mounted on a slide of the X-axis linear motion assembly and capable of moving along the Y-axis, a Z-axis linear motion assembly mounted on a power seat of the Y-axis linear motion assembly and capable of moving along the Z-axis, and a support mounted on a slider of the Z-axis linear motion assembly. The support is equipped with a detection device for cooperating with the clamping device to detect the electrode blank. The detection device includes a servo motor and a probe mounted on the drive shaft of the servo motor. The probe is a downward-opening groove-shaped structure, with the upper inner top surface of the groove-shaped structure serving as the top reference surface A, the right inner side surface of the groove-shaped structure serving as the right reference surface B, and the left inner side surface of the groove-shaped structure serving as the left reference surface C. The electrode blank is clamped and fixed by the blank clamping device and can be measured by the detection device.

[0008] The clamping device and the X-axis linear motion assembly are mounted on the same base plate, and the bottom of the base plate is equipped with four adjustable columns for load-bearing and height adjustment.

[0009] The X-axis linear motion assembly includes a first bracket and a second bracket fixedly mounted on the base plate, a transverse slide rail mounted between the first bracket and the second bracket, a slide block placed on the transverse slide rail, and a transverse drive device capable of driving the slide block to reciprocate along the transverse slide rail.

[0010] The two ends of the transverse slide rail are connected between bracket No. 1 and bracket No. 2 by axial adjusting screws and vertical adjusting screws, respectively.

[0011] The clamping device includes a stationary seat with a central hole and a movable seat mounted on the stationary seat. The stationary seat is provided with a planar positioning platform and a vertical positioning platform. The movable seat includes an upward-opening U-shaped seat, a support seat at the bottom of the U-shaped seat, and a mounting post at the bottom of the support seat that can be inserted into the central hole of the stationary seat and press the planar positioning platform against the bottom surface of the support seat. The bottom of the support seat is also provided with a positioning groove that cooperates with the vertical positioning platform. The opening of the U-shaped seat can accommodate electrode blanks of different geometric dimensions.

[0012] A dial is provided on one side of the U-shaped base.

[0013] The support is equipped with a high-potential interface, and the base plate is equipped with a low-potential interface that can be installed by adjusting the column.

[0014] The support has a stepped hole, the drive shaft extends into the stepped hole and is supported and positioned radially and axially by two bearings installed in the stepped hole, and a spacer is installed between the two bearings.

[0015] The top reference surface A, the right reference surface B, and the left reference surface C are all coated with a metallic coating.

[0016] The advantages of this utility model are:

[0017] Traditional measurement methods (such as the Renishaw probe used in machine measurement) measure surfaces by points. Three points define a plane, and five surfaces require at least fifteen measurements, or fifteen measurements in total. However, the surface-to-surface measurement method of this invention only requires five measurements for five surfaces, breaking through the limitations of traditional point-to-surface measurement. This reduces the number of measurements and significantly improves efficiency. In particular, the slotted probe structure is not only easy to manufacture and highly accurate, but also allows the rotating shaft to be driven by a servo motor, thus enabling the probe to measure the electrode blank. After the probe completes the measurement of three surfaces of the electrode blank, the rotating shaft drives the probe to rotate 90° (±90° rotation is possible) to continue measuring the other two surfaces. This achieves the measurement of all five surfaces of the electrode from the three base surfaces of the probe. In addition, the ingenious design of the entire structure enables continuous measurement work and rapid clamping of the electrode blank, further improving work efficiency. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural (front view) schematic diagram of the electrode blank measurement device of this utility model;

[0019] Figure 2 This is a three-dimensional structural (rear view) schematic diagram of the electrode blank measuring device of this utility model;

[0020] Figure 3 This is a front view of the electrode blank measuring device of this utility model;

[0021] Figure 4 This is a top view of the special measuring device for electrode blanks according to this utility model;

[0022] Figure 5 This is a right view of the special measuring device for electrode blanks according to this utility model;

[0023] Figure 6 for Figure 3 A schematic diagram of the AA cross-sectional structure;

[0024] Figure 7 This is a three-dimensional structural diagram of the movable seat in the clamping device of this utility model;

[0025] Figure 8 A three-dimensional structural diagram of the stationary seat in the utility model clamp release device;

[0026] Figure 9 This is a schematic diagram of the X-axis linear motion component;

[0027] Figure 10 This is a schematic diagram of the measurement state structure in this utility model;

[0028] Figure 11 This is a schematic diagram of the measurement state two structure in this utility model. Detailed Implementation

[0029] The electrode blank measuring device of this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] As shown in the figure, the electrode blank measuring device of this utility model includes a clamping device 2 for clamping the electrode blank 1, an X-axis linear motion assembly 3 capable of moving along the X-axis, a Y-axis linear motion assembly 4 mounted on the slide 13 of the X-axis linear motion assembly and capable of moving along the Y-axis, a Z-axis linear motion assembly 5 mounted on the power seat of the Y-axis linear motion assembly 4 and capable of moving along the Z-axis, and a support 6 mounted on the slider of the Z-axis linear motion assembly 5. The clamping device 2 and the X-axis linear motion assembly 3 are mounted on the same base plate 29. Four adjusting columns 32 for load-bearing and height adjustment are mounted on the bottom of the base plate 29. As shown in the figure, the four adjusting columns 32 can be made of bolts and mounted on the base plate 29 by eight nuts. That is, each adjusting column 32 is provided with a pair of nuts respectively. Nuts are pressed on the upper and lower sides of the base plate 29, thereby adjusting the height of the base plate. The support 6 is equipped with a high-potential interface 30, and the base plate 29 is equipped with a low-potential interface 31 installed via the adjusting column 32. The support is equipped with a detection device 7 for detecting the electrode blank in conjunction with the clamping device. The detection device 7 includes a servo motor 8 and a drive shaft connected to the output shaft of the servo motor. A probe 10 is installed on the drive shaft 9. Specifically, the support 6 is provided with a stepped hole, and the drive shaft 9 extends into the stepped hole and is radially and axially supported and positioned by two bearings 36 arranged in the stepped hole. A spacer 45 is placed between the two bearings. The probe 10 is a groove-shaped structure with an opening facing downward (inverted U-shape). The probe 10 is fixedly installed at the bottom of the drive shaft by a locking nut 35, so that it can rotate under the drive of the servo motor 8. Figure 6 As can be seen, the servo motor 8 is installed on the top of the support, one end of the transmission shaft is connected to the output shaft of the motor via a key, and the other end of the transmission shaft is connected to the probe via a locking nut 35. The transmission shaft is radially and axially supported and positioned by a pair of bearings 36 set in the stepped hole. The spacer 45 is used for axial positioning of the inner ring of the pair of bearings. After the probe 10 is installed, the upper inner top surface of the groove structure is used as the top reference surface A, the right inner side surface of the groove structure is used as the right reference surface B, and the left inner side surface of the groove structure is used as the left reference surface C. During processing, its form and position tolerance accuracy is very high. The probe 6 can realize the movement of the three linear axes X, Y and Z, as well as the rotational movement along the transmission shaft. Thus, after the electrode blank 1 is clamped and fixed by the blank loosening device 2, it can be measured by the detection device 7.

[0031] Furthermore, the aforementioned clamping device 2 includes a stationary seat 18 with a central hole 17 and a movable seat 19 mounted on the stationary seat. The stationary seat is fixed to the base plate by a threaded connection. The clamping device 2 enables rapid and accurate clamping and positioning of the electrode blank. The top surface of the stationary seat 18 is provided with a planar positioning platform 20 and a vertical positioning platform 21. Figure 8As can be seen, the moving base 19 includes an upward-opening U-shaped base 24, a support base 25 at the bottom of the U-shaped base, and a mounting post 26 at the bottom of the support base. The mounting post 26 can be inserted into the center hole 17 of the stationary base 18 and press the planar positioning platform 20 against the bottom surface of the support base 25. The bottom of the support base 25 is also provided with a positioning groove 27 that cooperates with the vertical positioning platform 21. That is to say, the bottom surface of the support base 25 and the positioning groove 27 respectively achieve positioning in three aspects with the planar positioning platform 20 and the vertical positioning platform 21 of the stationary base. Electrode blanks of different geometric sizes can be placed in the opening of the U-shaped base 24. A scale 28 is provided on one side of the opening end of the U-shaped base 24. The scale 28 has a scale for positioning the position of the electrode blank 5. A long screw 34 for pressing and fixing the electrode blank in the U-shaped base 24 is connected in series on the other side. Thus, the electrode blank can be fixed to the moving base by the long screw. Adjusting the length of the long screw 34 can accommodate electrode blanks 1 of different sizes.

[0032] Furthermore, the X-axis linear motion assembly 3 includes a first bracket 33 and a second bracket 11 fixedly mounted on the base plate, a transverse slide rail 12 mounted between the first and second brackets, a slide block 13 mounted on the transverse slide rail, and a transverse drive device 14 capable of driving the slide block to reciprocate along the transverse slide rail. The two ends of the transverse slide rail 12 are connected between the first bracket 33 and the second bracket 11 respectively by axial adjusting screws 15 and vertical adjusting screws 16. For the specific structural design of the X-axis linear motion assembly 3, [the following is a more detailed description of the design, which is not directly related to the X-axis linear motion assembly 3 description]. Figure 9As can be seen, the X-axis linear motion assembly consists of an X-axis servo motor 37, a motor base plate 38, a coupling 39, a front lead screw seat 40, a ball screw pair 41, a linear guide pair 42, a slide 13, a base plate 43, and a rear seat plate 44. The slide 13 is mounted on the linear guide pair 42 and is installed in conjunction with the ball screw pair 41. The linear guide pair 42 is installed in conjunction with the transverse slide rail 12. Guided by the linear guide pair 42 and driven by the ball screw pair 41, the slide 13 generates linear motion. Regarding its installation structure, the X-axis linear motion assembly is directly installed with the base plate, specifically through the first bracket 33 and the second bracket 11 at both ends, achieving a fixed connection to the base plate. The first bracket 33 and the second bracket 11 are respectively fixed to the base plate with screws. The X-axis linear motion component 3 is fixed by axial and vertical adjustment screws, which can also adjust the horizontal position of the X-axis linear motion component 3 relative to the base plate. The Y-axis linear motion component is connected to the linear motion component, and the Z-axis linear motion component is connected to the Y-axis linear motion component. One end of the support is connected to the slider of the Z-axis linear motion component (an insulating layer is provided at the connection). In addition, the structural design of the Y-axis linear motion component 4 and the Z-axis linear motion component 5 is basically the same as that of the X-axis linear motion component 3, but the stroke is different. This embodiment will not repeat the description. In addition, Z-axis drag chain 22 and X-axis drag chain 23 can be provided to protect the Z-axis and X-axis wires from wear and scratches during movement.

[0033] Furthermore, to reduce weight, the probe is made of aluminum alloy, and the top reference surface A, right reference surface B, and left reference surface C are all coated with a metal coating to increase wear resistance.

[0034] The measurement principle is:

[0035] The moving base axis Oxy is taken as the absolute zero point of the X and Y directions, and the position Oz of the plane positioning stage 20 is taken as the absolute origin of the Z direction. The probe rotation center O′ is taken as the working origin. Its standby position (i.e., working zero point) is aligned with the moving base axis Oxy, i.e., coaxial. The working zero point of the probe is calibrated as (0, 0) relative to the absolute zero point. The distance of the probe A surface relative to the absolute origin Oz is calibrated as h. The inner length of the probe cavity is L. L1, L2, L′1, L′2, and h1 are the distances that the probe moves from the calibrated position to the surface of the workpiece. After the probe contacts the surface to be measured of the workpiece, the distance value relative to the absolute zero point is generated and recorded.

[0036] Based on the above conditions, the coordinates of the five faces of the workpiece, a, b, c, d, and e, are respectively: a(0, h-h1).

[0037] b(L / 2-L2,0)、c(-L / 2+L1,0)、d(0,L / 2-L′2)、e(0,-L / 2+L′1)

[0038] The length L of the workpiece 工 Width W 工 and height H 工 They are respectively:

[0039] L 工 =L-(L1+L2)

[0040] W 工 =L-( L′1+ L′2)

[0041] H 工 =h1-h2

[0042] From the above, we can obtain information such as the position coordinates and external dimensions of the five faces of the workpiece.

[0043] Work process (see) Figure 10-11 )

[0044] The surface of the electrode blank to be tested is top surface a, two end surfaces b and c, and two side surfaces d and e. The probe detection base surface is top surface A, two end surfaces B and C.

[0045] First, place the workpiece to be tested into the opening of the U-shaped seat 24 of the moving seat of the clamping device. The position can be adjusted according to the scale and clamped and fixed with long screws. Then, insert the mounting post 26 of the moving seat into the center hole of the stationary seat to fix the moving seat. After the workpiece to be tested is prepared, the probe of the detection device starts to move vertically downward from the working zero point position. The probe stops when the A surface of the probe contacts the a surface of the workpiece to be tested. Then, it moves upward a small distance, maintaining the movement gap. Then, the probe uses the B surface and the C surface to detect the workpiece respectively.

[0046] After inspecting surface A, the side head moves up a small distance to inspect surfaces B and C of the workpiece. After inspecting surfaces B and C, the side head moves up until its bottom surface is higher than the top surface of the workpiece, then rotates 90°. Surfaces B and C are then used to inspect surfaces d and e of the workpiece, respectively. After measuring all five surfaces (a, b, c, d, and e) of the workpiece, the moving base is removed, and the side head rotates 90° in the opposite direction to return to the zero point. At this point, the workpiece can be replaced, and the next inspection cycle can begin.

[0047] During the inspection process, the probe carries a high potential, while the workpiece blank carries a low potential. Before contact, there is no potential difference between the two, meaning no electrical signal is generated, and the probe continues to move. When any one of the three surfaces of the probe contacts the workpiece surface, a potential difference is formed, generating an electrical signal. Upon receiving the signal, the digital control center immediately stops, then instantly restarts to inspect the other surface.

[0048] Of course, the above description is not intended to limit the present utility model, and the present utility model is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present utility model should also fall within the protection scope of the present utility model.

Claims

1. A special electrode blank measuring device, comprising a loose clamping device (2) for clamping an electrode blank (1), an X-axis linear motion assembly (3) capable of moving along the X-axis direction, a Y-axis linear motion assembly (4) disposed on the slide (13) of the X-axis linear motion assembly and capable of moving along the Y-axis direction, a Z-axis linear motion assembly (5) disposed on the power seat of the Y-axis linear motion assembly (4) and capable of moving along the Z-axis direction, and a support (6) disposed on the slide of the Z-axis linear motion assembly (5), wherein the support (6) is provided with a detection device (7) for detecting the electrode blank in cooperation with the loose clamping device, the detection device (7) comprises a servo motor (8) and a measuring head (10) mounted on the transmission shaft (9) of the servo motor, the measuring head (10) is a downwardly open groove structure, and the upper inner top surface of the groove structure serves as a top reference surface A, the right inner side surface of the groove structure serves as a right side reference surface B, and the left inner side surface of the groove structure serves as a left side reference surface C, the electrode blank (1) is clamped and fixed by the blank loose clamping device (2) and can be measured by the detection device (7).

2. The electrode blank measuring apparatus of claim 1, wherein: The loose clamping device (2) and the X-axis linear motion assembly (3) are installed on the same bottom plate (29), and four adjusting columns (32) for bearing and height adjustment are installed on the bottom of the bottom plate (29).

3. The electrode blank measuring apparatus of claim 2, wherein: The X-axis linear motion assembly (3) comprises a first support (33) and a second support (11) fixedly installed on the bottom plate, a transverse slide rail (12) installed between the first support and the second support, the slide (13) disposed on the transverse slide rail, and a transverse driving device (14) capable of driving the slide to reciprocate along the transverse slide rail.

4. The electrode blank measuring apparatus of claim 3, wherein: The two ends of the transverse slide rail (12) are connected between the first support (33) and the second support (11) through axial adjustment screws (15) and vertical adjustment screws (16), respectively.

5. The electrode blank measuring apparatus of claim 1, 2, 3 or 4, characterized in that: The loose clamping device (2) comprises a static seat (18) with a central hole (17) and a dynamic seat (19) installed on the static seat, the static seat (18) is provided with a planar positioning table (20) and a vertical positioning table (21) on the top, the dynamic seat (19) comprises a U-shaped seat (24) with an upward opening, a support seat (25) provided at the bottom of the U-shaped seat, and a mounting column (26) capable of being inserted into the central hole (17) of the static seat (18) and making the planar positioning table (20) press against the bottom surface of the support seat (25), the bottom of the support seat (25) is further provided with a positioning groove (27) matched with the vertical positioning table (21), and the U-shaped seat (24) can accommodate electrode blanks of different geometric sizes in the opening.

6. The electrode blank measuring apparatus of claim 5, wherein: One side of the U-shaped seat (24) is provided with a scale disc (28).

7. The electrode blank measuring apparatus specially adapted for the measurement of the electrode blank according to claim 2, 3 or 4, characterized in that: The support (6) is provided with a high potential interface (30), and the bottom plate (29) is provided with a low potential interface (31) installed through the adjusting column (32).

8. The electrode blank measuring apparatus of claim 7, wherein: The support (6) is provided with a stepped hole, the transmission shaft (9) extends into the stepped hole and is positioned by two upper and lower bearings arranged in the stepped hole for radial and axial support, and a spacer sleeve (45) is arranged between the two bearings.

9. The electrode blank measuring apparatus of claim 8, wherein: The top reference surface A, the right reference surface B and the left reference surface C are all coated with a metal coating.

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