Numerical control spindle head for reciprocating wire cut electrical discharge machining tool

Abstract

A numerical control spindle head for a reciprocating wire cut electrical discharge machining tool is characterized in that the numerical control spindle head is provided with a Z-axis movement mechanism and a W-axis movement mechanism, and the Z-axis movement mechanism comprises a Z-axis carriage seat, a Z-axis carriage, a Z-axis guide rail pair, an upper wire and liquid guide assembly and a Z-axis servo driving mechanism; the W-axis movement mechanism comprises a W-axis guide rail, a W-axis first sliding block, a W-axis second sliding block, a W-axis first dragging plate, a W-axis second dragging plate, a tension detector, a movable guide wheel, a fixed guide wheel, a movable guide wheel base, a fixed guide wheel base and a W-axis servo driving mechanism. According to the scheme, the electrode wire section which bypasses the movable guide wheel and moves downwards in the Z direction is the cutting working section of the electrode wire, the W-axis movement mechanism detects and controls the tension of the electrode wire and directly acts on the cutting working section of the electrode wire, and the tension control over the electrode wire of the cutting working section is more direct and accurate.

Description

Technical Field

[0001] The invention relates to the technical field of electric spark wire cutting processing, in particular to a numerical control spindle head for a reciprocating wire electric spark wire cutting machine tool. Background Art

[0002] CNC reciprocating wire EDM machine (abbreviated as: EDM wire cutting machine) is a metal cutting processing equipment widely used in the processing of precision and complex parts in the manufacturing industries such as molds, aerospace, automobiles, energy, precision instruments, medical equipment, and electronic products, and plays an important role in industrial production. EDM wire cutting uses a continuously moving thin metal wire (called electrode wire) as an electrode to perform pulse spark discharge to erode metal and cut the workpiece into shape.

[0003] The mechanical system of the wire-cut EDM machine tool consists of a machine bed, a coordinate table, a wire transport mechanism, a wire rack mechanism, a taper mechanism, a lubrication system, etc. Among them, the wire transport mechanism refers to a mechanism used to drive the electrode wire to reciprocate, and the wire rack mechanism refers to a mechanism used to support the electrode wire. The wire rack mechanism is divided into a single-column cantilever type and a double-column gantry type. The single-column cantilever type is further divided into an upper wire arm and a lower wire arm. Generally, the lower wire arm is fixed, and the upper wire arm can be raised and moved (Z-axis motion). The "spindle head" in the CNC spindle head of this application refers to the upper wire arm that can be raised and moved (Z-axis motion), and "CNC" means that the lifting and moving (Z-axis motion) of the upper wire arm can be digitally controlled by a servo motor. Functionally, the CNC spindle head of the wire-cut EDM machine is used to install the upper wire guide nozzle, the upper working fluid nozzle and the upper guide wheel of the upper wire arm mechanism. This mechanism usually has a Z-axis motion mechanism, which can drive the upper wire guide nozzle, the upper working fluid nozzle and the upper guide wheel to perform CNC lifting and lowering movements along the Z-axis.

[0004] During the online cutting process, the electrode wire is supported on the wire frame mechanism through various guide wheels on the one hand, and driven by the wire transport mechanism to perform reciprocating cutting motion on the other hand. The tension control of the cutting section of the electrode wire is very important, which not only directly affects the cutting accuracy and cutting quality, but also directly affects the cutting efficiency and the service life of the electrode wire. The prior art provides a variety of technical solutions for constant tension control of electrode wire (not illustrated here one by one). But in general, there are more or less some problems, such as inaccurate tension control, the existence of guide wheels, feed blocks and other links between the tension control section of the electrode wire and the cutting working section, resulting in indirect tension control, and additional deviations.

[0005] In view of this, how to design a method that can control the tension of the electrode wire in the cutting working section more directly and accurately is the research topic of the present invention. Summary of the invention

[0006] The invention provides a numerically controlled spindle head for a reciprocating wire electric spark wire cutting machine tool, and aims to solve the problem that the tension control of the electrode wire in the cutting working section is indirect and inaccurate.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a CNC spindle head for a reciprocating wire-cut electric spark wire cutting machine tool, and its innovation lies in: the CNC spindle head has a Z-axis motion mechanism and a W-axis motion mechanism, and the up and down direction of the machine tool in the working state is defined as the Z direction, the left and right direction is the X direction, and the front and back direction is the Y direction, wherein the axes of the Z axis and the W axis are both arranged parallel in the Z direction.

[0008] The Z-axis motion mechanism includes a Z-axis carriage seat, a Z-axis carriage, a Z-axis guide rail pair, an upper wire guide assembly and a Z-axis servo drive mechanism, wherein: The Z-axis carriage seat is fixed relative to the machine tool column, and the Z-axis carriage is connected to the Z-axis carriage seat through a Z-axis guide pair, and the Z-axis guide pair guides the Z-axis carriage to move precisely in the Z-axis direction.

[0009] The upper wire guide and liquid guide assembly is positioned and installed on the Z-axis carriage.

[0010] The Z-axis servo drive mechanism is connected to the Z-axis carriage and can drive the Z-axis carriage to perform digital linear motion in the Z direction.

[0011] The W-axis motion mechanism includes a W-axis guide rail, a W-axis first slider, a W-axis second slider, a W-axis first carriage, a W-axis second carriage, a tension detector, a movable guide wheel, a fixed guide wheel, a movable guide wheel seat, a fixed guide wheel seat and a W-axis servo drive mechanism, wherein: The W-axis guide rail is fixedly mounted on the Z-axis carriage seat, the W-axis first slider and the W-axis second slider are both mounted on the W-axis guide rail, and the W-axis first slider and the W-axis second slider are both able to move precisely in the W-axis direction along the W-axis guide rail, and the W-axis first slider is located above the W-axis second slider.

[0012] The W-axis first carriage is fixedly connected to the W-axis first slider, and the W-axis second carriage is fixedly connected to the W-axis second slider.

[0013] The tension detector has an upper action end and a lower action end, the upper action end is fixedly connected to the first carriage of the W axis, and the lower action end is fixedly connected to the second carriage of the W axis. The connecting line between the upper action end and the lower action end is parallel to the Z direction, so that the force direction of the tension detector is the Z direction.

[0014] The movable guide wheel is rotatably connected to the movable guide wheel seat, and the movable guide wheel is positioned and connected to the second carriage of the W axis through the movable guide wheel seat, the axis of the movable guide wheel is perpendicular to the YZ plane, and the axis of the electrode wire that passes around the movable guide wheel and goes down in the Z direction is parallel to the Z direction. The fixed guide wheel is rotatably connected to the fixed guide wheel seat, and the fixed guide wheel is fixedly connected to the Z axis carriage seat through the fixed guide wheel seat, and the axis of the fixed guide wheel is parallel to the axis of the movable guide wheel.

[0015] The W-axis servo drive mechanism is drivingly connected to the first W-axis carriage, and can drive the first W-axis carriage and drive the second W-axis carriage to perform digital linear motion in the Z direction through a tension detector.

[0016] In the working state, the electrode wire section that passes by the movable guide wheel and descends along the Z direction to the lower wire guide nozzle on the lower wire arm of the machine tool is the cutting working section of the electrode wire.

[0017] In the working state, the gravity of the W-axis second slider, the W-axis second carriage, the moving guide wheel seat, the moving guide wheel and the electrode wire tension acting on the moving guide wheel act vertically downward along the Z direction on the lower acting end of the tension detector, and the W-axis servo drive mechanism acts vertically upward along the Z direction on the upper acting end of the tension detector through the pulling force of the W-axis first carriage. The machine tool control system can achieve constant tension control of the electrode wire according to the electrode wire tension data measured by the tension detector by servo control of the W-axis drive to drive the W-axis first carriage and the moving guide wheel, and the electrode wire tension control directly acts on the cutting working section of the electrode wire.

[0018] The relevant contents in the above technical solution are explained as follows: 1. In the above scheme, the upper wire guide nozzle and the working liquid nozzle in the upper wire guide and liquid guiding assembly are both positioned and installed on the Z-axis carriage, wherein the working liquid nozzle is arranged below the upper wire guide nozzle. In the present invention, the upper wire guide and liquid guiding assembly is a general term for structures such as wire guide, liquid spray, and power inlet, some of which are composed of an upper main guide wheel, a wire guide nozzle, a nozzle, and a power inlet block, some of which are composed of a wire guide nozzle, a nozzle, and a power inlet block, and some of which are composed of an upper main guide wheel, a nozzle, and a power inlet block. The drawings of the embodiments of the present invention only show the upper wire guide nozzle and the working liquid nozzle.

[0019] 2. In the above scheme, the Z-axis guide pair is composed of a Z-axis guide rail and a Z-axis slider. One of the Z-axis guide rail and the Z-axis slider is fixedly mounted on the Z-axis carriage seat, and the other is fixedly mounted on the Z-axis carriage. The Z-axis guide rail is arranged along the Z-axis, and the Z-axis slider is mounted on the Z-axis guide rail and can make precise movements in the Z-axis direction.

[0020] 3. In the above scheme, the Z-axis guide pair consists of a Z-axis fixed rail and a Z-axis movable rail. The Z-axis fixed rail is fixedly connected to the Z-axis carriage seat, the Z-axis movable rail is fixedly connected to the Z-axis carriage, and the Z-axis fixed rail and the Z-axis movable rail are movably matched.

[0021] 4. In the above scheme, the Z-axis servo drive mechanism is composed of a synchronous pulley pair, a Z-axis screw nut pair and a Z-axis servo motor, wherein the synchronous pulley pair is composed of a first pulley, a second pulley and a synchronous belt, and the Z-axis screw nut pair is composed of a Z-axis screw and a Z-axis nut.

[0022] The Z-axis servo motor is fixedly mounted on the Z-axis carriage seat, and the Z-axis servo motor is connected to the first pulley in a transmission manner, and the axis of the Z-axis servo motor is coaxial with the axis of the first pulley and parallel to the Z direction. The first pulley is connected to the second pulley in a transmission manner through a synchronous belt, and the axis of the first pulley is parallel to the axis of the second pulley. The second pulley is connected to the Z-axis lead screw in a transmission manner, and the Z-axis lead screw cooperates with the Z-axis nut, and the axis of the second pulley, the axis of the Z-axis lead screw, and the axis of the Z-axis nut are coaxial and parallel to the Z direction. The Z-axis nut is fixedly connected to the Z-axis carriage.

[0023] 5. In the above scheme, the W-axis servo drive mechanism is composed of a W-axis screw nut pair and a W-axis servo motor, the W-axis screw nut pair is composed of a W-axis screw and a W-axis nut, the motor shaft of the W-axis servo motor is coaxially fixedly connected with the W-axis screw, the W-axis servo motor is fixedly installed on the Z-axis carriage seat, the motor shaft axis of the W-axis servo motor is parallel to the Z direction, the W-axis nut cooperates with the W-axis screw, and the W-axis nut is fixedly connected to the W-axis first carriage.

[0024] Due to the application of the above scheme, the present invention has the following substantial characteristics and effects compared with the prior art: 1. The present invention ingeniously designs a W-axis motion mechanism on the Z-axis carriage and the Z-axis carriage seat, which has a compact structure, is scientific and reasonable, and meets the functional requirements of automatic wire threading of machine tools; 2. The W-axis motion mechanism of the present invention realizes the online detection of the tension change of the machine tool electrode wire by the tension detector through the design of the connection structure of the tension detector. The machine tool control system can realize the constant tension control of the electrode wire through the servo control of the W-axis servo motor according to the measured electrode wire tension data. In particular, the W-axis motion mechanism directly acts on the cutting working section of the electrode wire to control the tension of the electrode wire, avoiding the existing tension control mechanism that does not directly act on the cutting working section of the electrode wire for tension detection and control, and the existence of links such as guide wheels and feed blocks between the tension control section of the electrode wire and the cutting working section, resulting in indirect tension control and additional deviations. Therefore, the design of the present invention is more direct and more accurate in controlling the tension of the electrode wire in the cutting working section.

[0025] 3. The W-axis motion mechanism of the present invention can not only better control the tension of the electrode wire during machine tool cutting processing, but also can set different tension values ​​according to the requirements of automatic wire threading during the automatic wire threading process, control the tension of the electrode wire, and cooperate with the machine tool wire storage drum and wire feeding mechanism to complete the automatic wire collection task of the electrode wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Attached Figure 1 This is a front view of the CNC spindle head according to an embodiment of the present invention.

[0027] Attached Figure 2 This is a top view of the CNC spindle head according to an embodiment of the present invention.

[0028] Attached Figure 3 It is a right view of the CNC spindle head according to an embodiment of the present invention.

[0029] Attached Figure 4 for Figure 3 AA section view.

[0030] Attached Figure 5 It is the principle diagram of the W-axis motion mechanism of the present invention.

[0031] In the above figures: 1. Z-axis carriage seat; 2. Z-axis carriage; 3. Z-axis servo motor; 4. Upper wire guide nozzle; 5. Working fluid nozzle; 6. W-axis guide rail; 7. W-axis first slider; 8. W-axis second slider; 9. W-axis first carriage; 10. W-axis second carriage; 11. Tension detector; 12. Moving guide wheel; 13. Fixed guide wheel; 14. Moving guide wheel seat; 15. Fixed guide wheel seat; 16. W-axis servo motor; 17. Upper working end; 18. Lower working end; 21. Electrode wire; 22. Z-axis guide rail; 23. Z-axis slider; 24. First pulley; 25. Second pulley; 26. Synchronous belt; 27. Z-axis screw; 28. Z-axis nut; 29. ​​W-axis screw; 30. W-axis nut. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the accompanying drawings and embodiments: Embodiment: A numerically controlled spindle head for a reciprocating wire electric spark cutting machine tool.

[0033] like Figure 1-5 As shown, the CNC spindle head has a Z-axis motion mechanism and a W-axis motion mechanism, and the up and down direction of the machine tool in the working state is defined as the Z direction, the left and right direction is the X direction, and the front and back direction is the Y direction, wherein the axes of the Z axis and the W axis are both arranged parallel in the Z direction.

[0034] The Z-axis motion mechanism includes a Z-axis carriage seat 1 (see Figure 1 , Figure 3 and Figure 4 )、Z-axis carriage 2 (see Figure 2 , Figure 3 and Figure 4 ), Z-axis guide rail pair, upper wire guide nozzle 4 and Z-axis servo drive mechanism, wherein: The Z-axis carriage seat 1 is fixed relative to the machine tool column, and the Z-axis carriage 2 is connected to the Z-axis carriage seat 1 through a Z-axis guide pair, which guides the Z-axis carriage 2 to move precisely in the Z-axis direction. In this embodiment, the Z-axis guide pair is composed of a Z-axis guide rail 22 and a Z-axis slider 23 (see Figure 4 ), the Z-axis guide rail 22 is fixedly mounted on the Z-axis carriage seat 1, and two Z-axis sliders 23 are fixedly mounted on the Z-axis carriage 2 (see Figure 4 ). The present invention is not limited to this, and the two Z-axis sliders 23 can also be replaced to be fixedly installed on the Z-axis carriage seat 1, and the Z-axis guide rail 22 is fixedly installed on the Z-axis carriage 2. That is, one of the Z-axis guide rail 22 and the Z-axis slider 23 is fixedly installed on the Z-axis carriage seat 1, and the other is fixedly installed on the Z-axis carriage 2. The Z-axis guide rail 22 is arranged along the Z axis (see Figure 4 ), two Z-axis sliders 23 are installed on the Z-axis guide rail 22 (see Figure 4 ), and can make precise movement in the Z-axis direction. In short, the best solution is: the Z-axis guide rail pair consists of a Z-axis fixed rail and a Z-axis movable rail, the Z-axis fixed rail is fixedly connected to the Z-axis carriage seat 1, the Z-axis movable rail is fixedly connected to the Z-axis carriage 2, and the Z-axis fixed rail and the Z-axis movable rail move in coordination.

[0035] The upper wire guide nozzle 4 is positioned and installed on the Z-axis carriage 2 (see Figure 1 , Figure 3 and Figure 4 The Z-axis motion mechanism includes a working fluid nozzle 5, which is positioned and mounted on the Z-axis carriage 2 and arranged below the upper wire guide nozzle 4 (see Figure 1 , Figure 3 and Figure 4 ).

[0036] The Z-axis servo drive mechanism is positioned and installed on the Z-axis carriage seat 1. The Z-axis servo drive mechanism is connected to the Z-axis carriage 2 and can drive the Z-axis carriage 2 to perform digital linear motion in the Z direction. In this embodiment, the Z-axis servo drive mechanism is composed of a synchronous pulley pair, a Z-axis lead screw nut pair and a Z-axis servo motor 3, wherein the synchronous pulley pair is composed of a first pulley 24, a second pulley 25 and a synchronous belt 26 (see Figure 1 and Figure 2 ), the Z-axis screw nut pair consists of a Z-axis screw 27 and a Z-axis nut 28 (see Figure 4 ).

[0037] The Z-axis servo motor 3 is fixedly mounted on the Z-axis carriage seat 1 (see Figure 1 ), the Z-axis servo motor 3 is connected to the first pulley 24 in transmission, and the axis of the Z-axis servo motor 3 is coaxial with the axis of the first pulley 24 and parallel to the Z direction (see Figure 1 The first pulley 24 is connected to the second pulley 25 through a synchronous belt 26 (see Figure 2 ), the axis of the first pulley 24 is parallel to the axis of the second pulley 25 (see Figure 1 The second pulley 25 is connected to the Z-axis lead screw 27 in a transmission manner (see Figure 4 ), the Z-axis screw 27 cooperates with the Z-axis nut 28 (see Figure 4 ), the axis of the second pulley 25, the axis of the Z-axis lead screw 27, and the axis of the Z-axis nut 28 are coaxial and parallel to the Z direction (see Figure 4 The Z-axis nut 28 is fixedly connected to the Z-axis carriage 2 (see Figure 4 ).

[0038] The W-axis motion mechanism includes a W-axis guide rail 6, a W-axis first slider 7, a W-axis second slider 8, a W-axis first carriage 9, a W-axis second carriage 10, a tension detector 11, a moving guide wheel 12, a fixed guide wheel 13, a moving guide wheel seat 14, a fixed guide wheel seat 15 and a W-axis servo drive mechanism (see Figure 5 ),in: The W-axis guide rail 6 is fixedly mounted on the Z-axis carriage seat 1 (see Figure 1 ), the W-axis first slider 7 and the W-axis second slider 8 are both installed on the W-axis guide rail 6 (see Figure 5 ), and the W-axis first slider 7 and the W-axis second slider 8 can both move precisely along the W-axis guide rail 6 in the W-axis direction (see Figure 5 ), the W-axis first slider 7 is located above the W-axis second slider 8 (see Figure 5 ).

[0039] The W-axis first carriage 9 is fixedly connected to the W-axis first slider 7 (see Figure 5 ,exist Figure 1 Because the W-axis first slider 7 is behind the W-axis first carriage 9 and is blocked, the W-axis second carriage 10 is fixedly connected to the W-axis second slider 8 (see Figure 5 ,exist Figure 1 Because the W-axis second slider 8 is behind the W-axis second carriage 10 and is blocked).

[0040] The tension detector 11 has an upper action end 17 and a lower action end 18 (see Figure 5 and Figure 3 ), the upper action end 17 is fixedly connected to the first carriage 9 of the W axis (see Figure 5 ), the lower action end 18 is fixedly connected to the second carriage 10 of the W axis (see Figure 5 ), the line connecting the upper action end 17 and the lower action end 18 is parallel to the Z direction, so that the force direction of the tension detector 11 is the Z direction (see Figure 5 ).

[0041] The movable guide wheel 12 is rotatably connected to the movable guide wheel seat 14, and the movable guide wheel 12 is positioned and connected to the second carriage 10 of the W axis through the movable guide wheel seat 14 (see Figure 1), the axis of the moving guide wheel 12 is perpendicular to the YZ plane, and the axis of the electrode wire 21 passing by the moving guide wheel 12 and descending in the Z direction is parallel to the Z direction (see Figure 1 and Figure 5 The fixed guide wheel 13 is rotatably connected to the fixed guide wheel seat 15, and the fixed guide wheel 13 is fixedly connected relative to the Z-axis carriage seat 1 through the fixed guide wheel seat 15 (see Figure 1 and Figure 5 ), the axis of the fixed guide wheel 13 is parallel to the axis of the movable guide wheel 12.

[0042] The W-axis servo drive mechanism is connected to the W-axis first carriage 9 and can drive the W-axis first carriage 9 and drive the W-axis second carriage 10 to perform digital linear motion in the Z direction through the tension detector 11. In this embodiment, the W-axis servo drive mechanism is composed of a W-axis lead screw nut pair and a W-axis servo motor 16 (see FIG. Figure 5 and Figure 3 ), the W-axis screw nut pair consists of a W-axis screw 29 and a W-axis nut 30 (see Figure 5 ), the motor shaft of the W-axis servo motor 16 is coaxially fixedly connected with the W-axis lead screw 29 (see Figure 5 ), the W-axis servo motor 16 is fixedly mounted on the Z-axis carriage seat 1, and the motor shaft axis of the W-axis servo motor 16 is parallel to the Z direction (see Figure 1 ), the W-axis nut 30 cooperates with the W-axis lead screw 29, and the W-axis nut 30 is fixedly connected to the W-axis first carriage 9 (see Figure 5 , Figure 5 The middle W-axis nut 30 is fixedly connected to the W-axis first carriage 9 via a transverse rod and a longitudinal rod, but the present invention is not limited thereto. Its essence is that the W-axis nut 30 is fixedly connected to the W-axis first carriage 9).

[0043] In the working state, the electrode wire section that passes by the movable guide wheel 12 and descends along the Z direction to the lower wire guide nozzle on the lower wire arm of the machine tool is the cutting working section of the electrode wire 21 (see Figure 1 and Figure 5 ).

[0044] In the working state, the gravity of the W-axis second slider 8, the W-axis second carriage 10, the movable guide wheel seat 14, the movable guide wheel 12, and the tension of the electrode wire 21 acting on the movable guide wheel 12 act vertically downward along the Z direction on the lower action end 18 of the tension detector 11 (see Figure 5 The W-axis servo drive mechanism acts vertically upward along the Z direction on the upper action end 17 of the tension detector 11 through the pulling force of the W-axis first carriage 9 (see Figure 5), the machine tool control system can realize constant tension control of the electrode wire 21 by servo control of the W-axis driving the W-axis first carriage 9 and the moving guide wheel 12 according to the tension data of the electrode wire 21 measured by the tension detector 11, and the tension control of the electrode wire 21 directly acts on the cutting working section of the electrode wire 21 (see Figure 5 ). The specific constant tension control process of the electrode wire 21 is: Figure 5 As shown, the constant tension control value range of the electrode wire 21 should be set in advance in the machine tool control system. During operation, the machine tool control system detects the current measured tension value through the tension detector 11, and then subtracts the measured tension value from the gravity of the W-axis second slider 8, the W-axis second carriage 10, the moving guide wheel seat 14, and the moving guide wheel 12, and then divides it by 2 to obtain the tension of the electrode wire 21 on the cutting working section. Then, the calculated tension of the electrode wire 21 is compared with the set constant tension control value range. When the tension of the electrode wire 21 falls within the constant tension control value range, it remains unchanged. When the tension of the electrode wire 21 is greater than the upper limit of the constant tension control, the machine tool control system starts the W-axis servo motor 16 to reverse, and the W-axis nut 30 drives the W-axis first carriage 9 and the W-axis first slider 7 to descend. Due to the gravity of the W-axis second slider 8, the W-axis second carriage 10, the movable guide wheel seat 14, and the movable guide wheel 12, the W-axis second slider 8, the W-axis second carriage 10, the movable guide wheel seat 14, and the movable guide wheel 12 are overall lowered, and the tension of the electrode wire 21 is reduced. The detection, calculation, and comparison are performed again until the tension of the electrode wire 21 falls within the constant tension control value range. When the electrode wire 21 is When the tension is less than the lower limit of the constant tension control, the machine tool control system starts the W-axis servo motor 16 to rotate forward, and the W-axis nut 30 drives the W-axis first carriage 9 and the W-axis first slider 7 to rise, and drives the W-axis second slider 8, the W-axis second carriage 10, the moving guide wheel seat 14, and the moving guide wheel 12 to rise as a whole through the upper action end 17, the tension detector 11 and the lower action end 18, and the tension of the electrode wire 21 increases, and the detection, calculation and comparison are performed again until the tension of the electrode wire 21 falls within the constant tension control value range. It can be seen that by using the W-axis motion mechanism of the present invention, the machine tool control system can not only realize the constant tension control of the electrode wire 21 by servo control of the W-axis drive to drive the W-axis first carriage 9 and the moving guide wheel 12 according to the tension data of the electrode wire 21 measured by the tension detector 11, but also the tension control of the electrode wire 21 directly acts on the cutting working section of the electrode wire 21, so the tension control of the electrode wire in the cutting working section is more direct and more accurate.

[0045] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A CNC spindle head for a reciprocating wire electric spark cutting machine tool, characterized in that: The CNC spindle head has a Z-axis motion mechanism and a W-axis motion mechanism. The up-down direction of the machine tool in the working state is defined as the Z direction, the left-right direction is the X direction, and the front-back direction is the Y direction. The axes of the Z-axis and the W-axis are both arranged parallel in the Z direction. The Z-axis motion mechanism comprises a Z-axis carriage seat (1), a Z-axis carriage (2), a Z-axis guide rail pair, an upper wire guide assembly and a Z-axis servo drive mechanism, wherein: The Z-axis carriage seat (1) is fixed relative to the machine tool column, and the Z-axis carriage (2) is connected to the Z-axis carriage seat (1) via a Z-axis guide pair, and the Z-axis guide pair guides the Z-axis carriage (2) to perform precise movement in the Z-axis direction; The upper wire guide and liquid guide assembly is positioned and mounted on the Z-axis carriage (2); The Z-axis servo drive mechanism is drivingly connected to the Z-axis carriage (2) and is capable of driving the Z-axis carriage (2) to perform digital linear motion in the Z direction; The W-axis motion mechanism comprises a W-axis guide rail (6), a W-axis first slider (7), a W-axis second slider (8), a W-axis first carriage (9), a W-axis second carriage (10), a tension detector (11), a movable guide wheel (12), a fixed guide wheel (13), a movable guide wheel seat (14), a fixed guide wheel seat (15) and a W-axis servo drive mechanism, wherein: The W-axis guide rail (6) is fixedly mounted on the Z-axis carriage seat (1), the W-axis first slider (7) and the W-axis second slider (8) are both mounted on the W-axis guide rail (6), and the W-axis first slider (7) and the W-axis second slider (8) are both capable of making precise movements along the W-axis guide rail (6) in the W-axis direction, and the W-axis first slider (7) is located above the W-axis second slider (8); The W-axis first carriage (9) is fixedly connected to the W-axis first slider (7), and the W-axis second carriage (10) is fixedly connected to the W-axis second slider (8); The tension detector (11) comprises an upper action end (17) and a lower action end (18), the upper action end (17) being fixedly connected to the first carriage (9) of the W axis, and the lower action end (18) being fixedly connected to the second carriage (10) of the W axis, and the line connecting the upper action end (17) and the lower action end (18) being parallel to the Z direction, so that the force direction of the tension detector (11) is the Z direction; The movable guide wheel (12) is rotatably connected to the movable guide wheel seat (14), and the movable guide wheel (12) is positionally connected to the second carriage (10) of the W axis through the movable guide wheel seat (14), the axis of the movable guide wheel (12) is perpendicular to the YZ plane, and the axis of the electrode wire (21) passing around the movable guide wheel (12) and descending in the Z direction is parallel to the Z direction; the fixed guide wheel (13) is rotatably connected to the fixed guide wheel seat (15), and the fixed guide wheel (13) is fixedly connected to the Z axis carriage seat (1) through the fixed guide wheel seat (15), and the axis of the fixed guide wheel (13) is parallel to the axis of the movable guide wheel (12); The W-axis servo drive mechanism is drivingly connected to the W-axis first carriage (9), and is capable of driving the W-axis first carriage (9) and, through the tension detector (11), driving the W-axis second carriage (10) to perform digital linear motion in the Z direction; In the working state, the electrode wire section that passes by the movable guide wheel (12) and descends along the Z direction to the lower wire guide nozzle on the lower wire arm of the machine tool is the cutting working section of the electrode wire (21); In the working state, the gravity of the W-axis second slider (8), the W-axis second carriage (10), the movable guide wheel seat (14), the movable guide wheel (12), and the tension of the electrode wire (21) acting on the movable guide wheel (12) act vertically downward on the lower action end (18) of the tension detector (11) along the Z direction, and the W-axis servo drive mechanism acts vertically upward on the upper action end (17) of the tension detector (11) along the Z direction through the pulling force of the W-axis first carriage (9). The machine tool control system can achieve constant tension control of the electrode wire (21) by servo control of the W-axis drive to drive the W-axis first carriage (9) and the movable guide wheel (12) according to the tension data of the electrode wire (21) measured by the tension detector (11), and the tension control of the electrode wire (21) directly acts on the cutting working section of the electrode wire (21).

2. The CNC spindle head according to claim 1, characterized in that: The upper wire guide nozzle (4) and the working fluid nozzle (5) of the upper wire guide and fluid guide assembly are both positioned and mounted on the Z-axis carriage (2), wherein the working fluid nozzle (5) is arranged below the upper wire guide nozzle (4).

3. The CNC spindle head according to claim 1, characterized in that: The Z-axis guide rail pair is composed of a Z-axis guide rail (22) and a Z-axis slider (23). One of the Z-axis guide rail (22) and the Z-axis slider (23) is fixedly mounted on the Z-axis carriage seat (1), and the other is fixedly mounted on the Z-axis carriage (2). The Z-axis guide rail (22) is arranged along the Z-axis. The Z-axis slider (23) is mounted on the Z-axis guide rail (22) and can be precisely moved in the Z-axis direction.

4. The CNC spindle head according to claim 1, characterized in that: The Z-axis guide rail pair is composed of a Z-axis fixed rail and a Z-axis movable rail. The Z-axis fixed rail is fixedly connected to the Z-axis carriage seat (1), the Z-axis movable rail is fixedly connected to the Z-axis carriage (2), and the Z-axis fixed rail and the Z-axis movable rail are movably matched.

5. The CNC spindle head according to claim 1, characterized in that: The Z-axis servo drive mechanism is composed of a synchronous pulley pair, a Z-axis lead screw nut pair and a Z-axis servo motor (3), wherein the synchronous pulley pair is composed of a first pulley (24), a second pulley (25) and a synchronous belt (26), and the Z-axis lead screw nut pair is composed of a Z-axis lead screw (27) and a Z-axis nut (28); The Z-axis servo motor (3) is fixedly mounted on the Z-axis carriage seat (1); the Z-axis servo motor (3) is connected to the first pulley (24) in a transmission connection; the axis of the Z-axis servo motor (3) is coaxial with the axis of the first pulley (24) and parallel to the Z direction; the first pulley (24) is connected to the second pulley (25) in a transmission connection via a synchronous belt (26); the axis of the first pulley (24) is parallel to the axis of the second pulley (25); the second pulley (25) is connected to the Z-axis lead screw (27); the Z-axis lead screw (27) cooperates with the Z-axis nut (28); the axis of the second pulley (25), the axis of the Z-axis lead screw (27) and the axis of the Z-axis nut (28) are coaxial and parallel to the Z direction; the Z-axis nut (28) is fixedly connected to the Z-axis carriage (2).

6. The CNC spindle head according to claim 1, characterized in that: The W-axis servo drive mechanism is composed of a W-axis lead screw nut pair and a W-axis servo motor (16) connected together; the W-axis lead screw nut pair is composed of a W-axis lead screw (29) and a W-axis nut (30); the motor shaft of the W-axis servo motor (16) is coaxially fixedly connected to the W-axis lead screw (29); the W-axis servo motor (16) is fixedly mounted on the Z-axis carriage seat (1); the motor shaft axis of the W-axis servo motor (16) is parallel to the Z direction; the W-axis nut (30) cooperates with the W-axis lead screw (29); and the W-axis nut (30) is fixedly connected to the W-axis first carriage (9).

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