A fast and slow combined wire cutting machine with automatic threading of molybdenum wire

Abstract

The invention discloses a fast-slow combined wire-feeding method for a molybdenum wire cutting machine tool, in which a section of the molybdenum wire used for cutting a workpiece is reciprocated at a line speed of 10-2000 meters per minute to cut the workpiece and is continuously updated at a line speed of 0-2 meters per minute; a numerically controlled motor is used to control the positive and negative rotation angle difference between an active wire-feeding wheel and a driven wire-feeding wheel to realize continuous updating during the reciprocating motion of the molybdenum wire.

Description

Technical Field

[0001] The invention relates to a wire-feeding method of an electric spark molybdenum wire cutting machine tool, and in particular to an automatic threading technology. Background Art

[0002] The existing molybdenum wire EDM machines are fast wire and medium wire, both of which use a wire drum to wind a fixed molybdenum wire for reciprocating wire cutting. The disadvantages of this wire cutting method are: 1. The molybdenum wire will become loose, and stripes will appear on the cut workpiece; 2. The molybdenum wire will wear out and become thinner, and precision errors will occur in the cut workpiece; 3. Accidental wire breakage requires replacement, which is costly; 4. Manual wire threading is required to change the cutting unit, and the labor cost is high. Therefore, a molybdenum wire EDM machine with fast and slow wire cutting and automatic threading is needed to ensure that the molybdenum wire does not loosen, the wire diameter remains unchanged, the cost of wire breakage is low, and automatic threading is achieved. Summary of the invention

[0003] The technical problem to be solved by the present invention is to solve the shortcomings of the existing molybdenum wire electric spark cutting machine tools and provide a molybdenum wire cutting machine tool with a fast and slow combined wire feeding and automatic threading.

[0004] The present invention provides a fast and slow combined wire-feeding automatic threading molybdenum wire cutting machine tool, characterized in that it comprises an active wire-feeding wheel guide rail (1), an active wire-feeding wheel seat (2), an active wire-feeding wheel (3), a wire hook rodless cylinder (4), a wire hook (5), a molybdenum wire unhooking clamp (6), a waste wire take-up device (7), a wire lifting wheel (8), a wire hook guide (9), a wire cutter (10), a molybdenum wire end bending clamp (11), a tension detector (12), a driven wire-feeding wheel (13), a driven wire-feeding wheel seat (14), a lower wire rack (15), an upper wire rack (16), an active wire-feeding wheel seat cylinder (17), and an active wire-feeding wheel motor (18).

[0005] The active wire-feeding wheel guide rail (1) is mounted on the upper wire frame (16) and is used for the active wire-feeding wheel seat (2) to change the cutting and threading positions under the push of the active wire-feeding wheel seat cylinder (17).

[0006] The active wire-cutting wheel (3) and the driven wire-cutting wheel (13) are made of nylon or other light materials, with a diameter of 100-200 mm, a weight of less than 200 grams, a wheel thickness of 15 mm, and a groove of 2 mm deep and 12 mm wide on the outer diameter of the wheel;

[0007] The active wire-moving wheel (3) has a notch (31) on its edge, and a spring pressure plate (32) at the notch. When the active wire-moving wheel rotates, the molybdenum wire on the outer side of the wheel can be guided into the groove and pressed by the spring pressure plate. A synchronous pulley (34) is mounted on the shaft of the active wire-moving wheel (3) and is driven by the active wire-moving wheel motor (18). The shaft center is a round hole (35) with a diameter of 2 mm. The active wire-moving wheel (3) is horizontally mounted on the active wire-moving wheel seat (2);

[0008] The wire hook rodless cylinder (4) is vertically fixed on the active wire-feeding wheel seat (2), and a limit switch (41) is installed on the side;

[0009] The wire hook (5) is a metal rod with a diameter of 0.6-1.5 mm, with a V-shaped notch at the lower end and a hook shape, and the upper end is fixed on the slider (42) of the wire hook rodless cylinder (4). When the wire hook moves downward, it can pass through the axial center hole of the active wire wheel (3);

[0010] The molybdenum wire unhooking clamp (6) is two stepped metal sheets, driven by a cylinder, and has a groove of the same diameter as the wire hook on the upper half when clamped, and is installed at the lower end of the wire hook rodless cylinder (4);

[0011] The waste wire take-up device (7) is composed of a take-up roller (71), a take-up roller motor (72), a take-up hook cylinder (73), and a roller cylinder (74). When taking up the wire, the take-up roller is separated and the take-up hook is extended from the take-up roller to pull the molybdenum wire into the waste wire box. The take-up roller is tightened to collect the waste wire into the waste wire box. The waste wire take-up device is fixed on the active wire wheel seat (2);

[0012] The wire lifting wheel (8) is composed of a rotating cylinder (81), a bracket (82), and a guide wheel (83), and is used to lift the molybdenum wire so that the molybdenum wire is close to the lower edge of the active wire wheel. The wire lifting wheel is installed on the upper wire rack (16);

[0013] The wire hook guide (9) has a hole in the center in the shape of a funnel, which is used to accurately guide the wire hook (5) into the threading hole of the workpiece, and the wire hook guide is installed below the upper wire rack (16);

[0014] The thread cutter (10) is composed of a cylinder (101) and a thread cutter (102), and is installed on a thread lowering rack (15);

[0015] The molybdenum wire end bending clamp (11) is composed of a rotating cylinder (111), a wire clamping claw (112), a wire clamping cylinder (113), and a shifting cylinder (114), and the molybdenum wire end bending clamp is installed on the lower wire rack (15);

[0016] The tension detector (12) is composed of a tension wheel (123), a spring (122), and a micro switch (121), and is installed below the lower wire rack (15);

[0017] A vortex spring (132) is provided between the wheel body (131) of the driven wire walking wheel (13) and the fixed seat (133). Under the action of the vortex spring, the driven wire walking wheel can be driven by the active wire walking wheel to rotate more than 5 turns when the fixed seat (133) does not rotate, and the molybdenum wire can be kept with sufficient tension. The driven wire walking wheel fixed seat is mounted on the shaft of the numerical control motor (134), and the driven wire walking wheel (13) is mounted below the lower wire frame (15). BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the active wire-feeding wheel;

[0020] Figure 3 It is a schematic diagram of the rodless cylinder of the lead hook;

[0021] Figure 4 It is a schematic diagram of the end of the lead hook;

[0022] Figure 5 This is a schematic diagram of the molybdenum wire unhooking clamp;

[0023] Figure 6 It is a schematic diagram of a waste wire take-up device;

[0024] Figure 7 It is a schematic diagram of the wire lifting wheel;

[0025] Figure 8 It is a schematic diagram of the lead hook guide;

[0026] Fig. 9 It is a schematic diagram of the thread trimmer;

[0027] Fig.10 This is a schematic diagram of the molybdenum wire end bending clamp;

[0028] Fig.11 is a schematic diagram of a tension detector;

[0029] Fig.12 This is a schematic diagram of the driven wire wheel;

[0030] Fig.13 This is a schematic diagram of the position of the active wire-feeding wheel in the threading state;

[0031] Fig.14 This is a schematic diagram of the wire clamping claws clamping the molybdenum wire;

[0032] Fig.15 This is a schematic diagram of the wire clamping claw clamping the molybdenum wire and then rotating it 90 degrees and then the wire hook is inserted;

[0033] Fig.16 This is a schematic diagram of the lead hook hooking the molybdenum wire and rising. DETAILED DESCRIPTION

[0034] The technical solution adopted by the present invention to solve the above-mentioned problem is as follows: the molybdenum wire is jointly wired by an active wire-walking wheel and a driven wire-walking wheel, 300-400 meters of new molybdenum wire is wound on the driven wire-walking wheel, one end of which passes through the workpiece and is fixed on the active wire-walking wheel, wherein the active wire-walking wheel is driven by a servo motor to rotate forward and reversely, and the rotation speed is more than 1000 revolutions per minute. When the active wire-walking wheel rotates forward, the driven wire-walking wheel is driven forward by the molybdenum wire, and the vortex spring is tightened at the same time, and the molybdenum wire is wound from the driven wire-walking wheel to the active wire-walking wheel. When the active wire-walking wheel reverses, the vortex spring is released to drive the driven wire-walking wheel to reverse, and the molybdenum wire is wound from the active wire-walking wheel to the driven wire-walking wheel. The active wire-walking wheel quickly changes its rotation direction to allow the molybdenum wire to quickly reciprocate. At the same time, the CNC motor controls the active wire-walking wheel to rotate forward at a greater angle than the reverse angle, so that the molybdenum wire cutting the workpiece is continuously updated. The lower wire rack is equipped with a molybdenum wire tension detector. When the vortex spring is too tight, the tension detector outputs a signal to control the driven wire-walking wheel seat motor to rotate forward to keep the molybdenum wire tension normal.

[0035] The following describes an automatic threading process of the present invention in conjunction with the accompanying drawings:

[0036] Step 1: The wire take-up roller (71) of the waste wire take-up device (7) is loosened, the wire take-up hook (73) is extended to pull the molybdenum wire into the wire take-up roller (71), and the wire take-up roller (71) is tightened;

[0037] Step 2: The wire clamping claw (112) extends forward and clamps the molybdenum wire, and the wire lead hook (5) is lowered by 5 mm to release the molybdenum wire by the molybdenum wire release clamp (6);

[0038] Step 3: The wire cutter (10) cuts the wire, the molybdenum wire unhooking clamp (6) opens, the active wire feeding wheel (3) reverses at 10 turns per minute, and the wire take-up roller motor (72) starts to transfer the waste wire into the waste wire box;

[0039] Step 4: The clamping claw (112) rotates 90 degrees;

[0040] Step 5: The workpiece moves to the next cutting unit;

[0041] Step 6: the wire lifting wheel (8) descends;

[0042] Step 7: The active wire-feeding wheel seat (2) moves to the threading position;

[0043] Step 8: The wire hook (5) moves downward and passes through the center hole of the active wire wheel (3), the wire hook guide (9), the workpiece wire threading hole, and the wire clamping claw (112) in sequence;

[0044] Step nine: the wire hook (5) rises, hooks the end of the molybdenum wire and pulls it upward, and uses the friction force of the wire clamping claw (112) to pull the end of the molybdenum wire into an acute angle, and the wire clamping claw (112) is released and retreated;

[0045] Step 10: The wire hook (5) pulls the end of the molybdenum wire to the top of the molybdenum wire unhooking clamp (6);

[0046] Step 11: Clamp the molybdenum wire unhooking clamp (6)

[0047] Step 11: the active wire-feeding wheel seat (2) moves to a normal cutting position;

[0048] Step 12: The wire lifting wheel (8) rises to make the molybdenum wire close to the lower edge of the active wire feeding wheel (3);

[0049] Step 13: The active wire-feeding wheel (3) rotates one circle forward, so that the molybdenum wire enters the outer edge groove from the edge notch of the active wire-feeding wheel (3), and the threading is completed;

[0050] The above actions are controlled by PLC. For the first threading or accidental wire breakage, the end of the molybdenum wire needs to be manually placed into the wire clamping claw (112) and the PLC control is started to complete the threading action.

Claims

1. A method for automatically threading a molybdenum wire cutting machine with a combination of fast and slow wire feeding, characterized in that: It includes an active wire wheel, a wire hook, a molybdenum wire unhooking clamp, a waste wire take-up device, a wire lifting wheel, a wire cutter, a molybdenum wire end bending clamp, a driven wire wheel, and a driven wire wheel with a vortex spring; the active wire wheel can move horizontally, and has a round hole in the center for automatically threading a wire strip, a notch on the edge for guiding the molybdenum wire, and a spring pressing sheet at the notch. When the active wire wheel rotates, the molybdenum wire on the outside of the wheel can be guided into the groove and pressed by the spring pressing sheet; one section of the molybdenum wire used for cutting the workpiece reciprocates at a linear speed of 10-2000 meters per minute to cut the workpiece, and is continuously updated at a linear speed of 0-2 meters per minute; The CNC motor controls the positive and negative rotation angle difference between the active wire-feeding wheel and the driven wire-feeding wheel to realize the continuous updating of the molybdenum wire during the reciprocating motion.

2. A wire-feeding device for a molybdenum wire cutting machine tool with automatic wire threading and fast and slow wire-feeding method as claimed in claim 1, characterized in that: The active wire-moving wheel is driven by a CNC motor for forward rotation, and drives the driven wire-moving wheel to rotate forward while tightening the vortex spring of the driven wire-moving wheel. The active wire-moving wheel is driven by a CNC motor for reverse rotation, and the vortex spring of the driven wire-moving wheel is released to drive the driven wire-moving wheel to reverse and synchronize with the active wire-moving wheel and maintain the molybdenum wire tension.

3. A molybdenum wire cutting machine tool with automatic wire threading and fast and slow wire feeding method as claimed in claim 1.

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