TWI643688B - Fluid-controlled wire tension mechanism - Google Patents

Abstract

The invention provides a fluid-type wire tension control mechanism, which includes a closed container, a control valve, and a wire feeding shaft. The closed container has a receiving space. The control valve is coupled to the closed container and is used to control a fluid pressure in the accommodating space. The spool is coupled to the closed container and has a pressure receiving portion and a coil portion. The pressure part is contained in the accommodating space, and the coil part is located outside the closed container for sending out a cutting line. Among them, a fluid enters the accommodating space through the control valve and presses the pressured portion. The invention uses the fluid pressure to generate a rotation resistance to the wire feeding shaft that sends out the cutting wire, thereby the parts are not easy to wear, the wire tension is easy to be controlled, and the stream of the cutting wire can remain stable for a long time. Therefore, by applying the electric discharge machining technology of the present invention, the cutting effect and shape are more precise.

Description

Fluid type wire tension control mechanism

The invention provides a thread tension control mechanism, and in particular, relates to a non-contact control mechanism for controlling the tension of a discharge cutting wire by using fluid pressure.

In recent years, with the advancement of semiconductor, electronics, and machinery technologies, most products have been developed towards small and refined aspects. In particular, the industry of two trillion double stars is developing in the direction of miniaturization. The industry has a great demand for the production of light, thin, short and small components, such as micro molds, jigs, tools, tools, fixtures or probes. The materials made are also increasingly difficult to cut, such as: tungsten, boron nitride, polycrystalline diamond, single crystal diamond, etc. All the above requirements can be solved by wire cutting EDM technology. The market for wire cutting EDM technology is obvious.

In wire cutting EDM technology, wire tension is a very important factor. The cutting precision of the wire tension control structure affects the processing accuracy and judges whether the wire pole is broken. At present, the industry uses brakes to control its line tension. However, it is difficult to make small adjustments and controls in the brake group mode. Moreover, in the brake group mode, the brake group and the discharge line need to be in direct contact. Affected by the material friction coefficient, the line tension of the cutting line is difficult to be stably controlled.

Using permanent magnets instead of brakes is a non-contact control method. In this method, the distance between the permanent magnet and the wire pole is adjusted to control the amount of wire tension. The modulation range of the distance has its limits, and at the same time, the line tension of the poles cannot be accurately adjusted. Furthermore, If multiple wire electrodes need to be used at the same time to achieve high-efficiency cutting, it is difficult to adjust multiple wire tensions for the wire electrodes with an array arrangement. In addition, when the permanent magnet controls the tension of the wire, the hysteresis easily occurs, and the stream of the wire becomes very unstable.

Therefore, the industry urgently needs a new tension control device to replace the brake group or permanent magnet type control device.

In view of this, the present invention proposes a fluid-type wire tension control mechanism, which uses a fluid to apply pressure to a wire feeding shaft that sends out a cutting wire, so that the wire feeding shaft generates a rotation resistance. Under the condition that the take-up shaft is taken up at a fixed speed, the thread tension can be determined by the pressure exerted by the fluid on the take-up shaft, and then the appropriate tension can be obtained.

The fluid-type thread tension control mechanism of the present invention is used to adjust a fluid pressure generated by a fluid to control the tension of a cutting line, and includes a closed container, a control valve, and a spool. The closed container has a containing space for containing a fluid. The control valve is coupled to the closed container and is used to control the fluid pressure generated by the fluid in the accommodating space. The spool is threaded through the closed container. The spool includes a pressure receiving portion and a coil portion, and the coil portion is linked with the pressure receiving portion. The pressure-receiving portion is accommodated in the accommodating space, and the coil portion is located outside the closed container and sends out the cutting line. The tension of the cutting line is controlled by a fluid damping force in response to a fluid pressure applied to the pressure receiving portion.

In a specific embodiment, the flow system is liquid or gas, and the cutting line is a metal line.

Furthermore, the coil part is coupled to the cutting wire, and the coil part is linked to the pressure receiving part for coupling or winding the cutting wire.

The coil portion is detachably fitted into the pressure receiving portion.

In a specific embodiment, the closed container further includes a flow guide hole, a bearing, a sealing cap, an O-ring, and a sealing cup. The diversion hole is used for allowing fluid to enter the accommodating space. The sealing cup has a flow guide hole, and the sealing cover and the sealing cup are sealed by an O-ring to form an accommodation space. The wire feeding shaft is coupled to the sealing cover through a bearing.

In a specific embodiment, the fluid-type wire tension control mechanism further includes a disc disposed on the pressure receiving portion of the wire feeding shaft, and the disc is used to withstand the pressure applied by the fluid.

In addition, the fluid type thread tension control mechanism further includes a take-up shaft for receiving the cutting wire sent from the coil portion of the delivery shaft.

Among them, the feeding shaft is used to control the tension of the cutting line, and the winding shaft is used to control the moving speed of the cutting line.

In a specific embodiment, the fluid-type wire tension control mechanism further includes a plurality of wire feeding shafts. The plurality of thread feeding shafts form an array and are parallel to each other, and the plurality of thread feeding shafts can respectively send out and control the tension of the cutting line.

The control valve can control the total amount of the fluid in the accommodating space, the inflow amount of fluid per unit time into the accommodating space, the inflow pressure of the fluid into the accommodating space, or the volume in the accommodating space.

In summary, the present invention uses a fluid to apply pressure to a feeding shaft that sends out a cutting wire, so that the feeding shaft generates a rotational resistance. Under the condition that the take-up shaft takes up at a fixed speed, the take-up shaft is subject to a fluid damping force opposite to the direction of the take-up. The greater the fluid pressure, the more obvious the damping effect produced by the spool. Therefore, as the fluid pressure increases, the tension value of the cutting line becomes larger, and the straightness of the cutting line becomes higher accordingly. Because the fluid pressure does not directly act on the cutting line, the cutting line can maintain a stable stream, and the line tension is easy to grasp and control. Since the present invention does not use solid contact friction This method generates resistance, and the thread tension control mechanism is less prone to the problem of part wear. Therefore, the fluid thread tension control mechanism of the present invention can maintain stable transmission of the cutting line for a long time, and the shape of the cut is more precise.

1‧‧‧fluid wire tension control mechanism

10‧‧‧ airtight container

11‧‧‧ send spool

15‧‧‧Control Valve

16‧‧‧ take-up spool

100‧‧‧ accommodation space

104‧‧‧oil seal

103‧‧‧bearing

106‧‧‧ Diversion holes

107‧‧‧Sealing cover

108‧‧‧Sealed Cup

109‧‧‧O-ring

110‧‧‧Pressed section

111‧‧‧Drive shaft

116‧‧‧Coil Department

6‧‧‧ cutting line

A‧‧‧total surface area

A1‧‧‧first area

A2‧‧‧Second Area

A3‧‧‧ Third Area

R _s1 ‧‧‧disk radius

R _s2 ‧‧‧ Radius of transmission shaft

t _s ‧‧‧ thickness

FIG. 1 is a perspective view illustrating a fluid type thread tension control mechanism according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a fluid type thread tension control mechanism according to a specific embodiment of the present invention.

FIG. 3 is a schematic diagram of a bobbin according to a specific embodiment of the present invention.

FIG. 4 is a schematic diagram showing another angle of a spool according to a specific embodiment of the present invention.

FIG. 5A is a plan view of the pressure receiving portion as viewed from one end away from the transmission shaft.

Fig. 5B is a plan view of the pressure receiving portion viewed from the end of the transmission shaft.

FIG. 6 is a schematic diagram of a fluid type thread tension control mechanism according to another embodiment of the present invention.

In order to make the advantages, spirits and features of the present invention easier and clearer, it will be detailed and discussed in the following with reference to the embodiments and the accompanying drawings. It is worth noting that these embodiments are only representative embodiments of the present invention, and the specific methods, devices, conditions, materials, etc. illustrated therein are not intended to limit the present invention or corresponding embodiments.

In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "vertical, horizontal, top, bottom, front, back, left, right, top, bottom, inside, outside" and the like is based on the drawings. The orientations or position relationships shown are only for the convenience of describing the present invention and simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, structure and operation in a specific orientation, so it cannot be understood as limit.

In addition, the indefinite articles "a", "an", and "an" before the device or element of the present invention do not limit the number of devices or elements (ie, the number of occurrences). Thus, "a" should be read as including one or at least one, and a device or element in the singular also includes the plural unless the number clearly refers to the singular.

Please refer to FIG. 1 and FIG. 2. FIG. 1 is a perspective view of a fluid type thread tension control mechanism 1 according to an embodiment of the present invention. FIG. 2 is a schematic diagram of a fluid type thread tension control mechanism 1 according to a specific embodiment of the present invention. The fluid-type wire tension control mechanism 1 of the present invention is used to adjust a fluid pressure generated by a fluid to control the tension of a cutting wire 6, and includes a closed container 10, a control valve 15, and a spool 11. The closed container 10 has a containing space 100 for containing a fluid. The control valve 15 is coupled to the closed container 10 to control a fluid pressure generated by the fluid in the accommodating space 100. The bobbin 11 is threaded through the closed container 10. The bobbin 11 includes a pressure receiving portion 110 and a coil portion 116. The pressure receiving portion 110 is linked with the coil portion 116. The pressure receiving portion 110 is accommodated in the accommodating space 100, and the coil portion 116 is located outside the closed container 10 and sends out the cutting line 6. The tension of the cutting line 6 is controlled by a fluid damping force in response to a fluid pressure applied to the pressure receiving portion 110.

After the fluid enters the accommodating space 100, a fluid pressure is generated in the accommodating space 100. At this time, the pressure receiving part 110 in the accommodating space 100 will bear the fluid pressure. When the coil portion 116 is rotated by sending out the cutting line 6, the pressure receiving portion 110 is rotated synchronously. Because the pressure receiving portion 110 is affected by the rotation resistance caused by the fluid pressure when rotating, the coil portion 116 that drives the other end of the spool 11 tends to slow down the rotation speed, thereby generating a tensile force opposite to the direction of the cutting line 6 being sent out. Finally, because the cutting wire 6 moves at a constant speed, the tension of the cutting wire 6 increases.

When the control valve 15 is adjusted to increase the fluid pressure in the accommodating space 100, the fluid pressure and rotation resistance received by the pressure receiving portion 110 will increase, and the tensile force applied to the coil portion will become stronger. Therefore, the tension of the cutting wire 6 is increased. Conversely, when the control valve 15 is adjusted to reduce the fluid pressure in the accommodating space 100, the tension of the cutting wire 6 is also reduced accordingly. In one embodiment, the manner in which the control valve 15 controls the pressure of the fluid in the accommodating space 100 may be to continuously feed fluid into the accommodating space. At this time, the sealed container 10 may have another fluid outlet to allow the fluid to flow out, thereby adjusting the pressure of the fluid in the sealed container, and the fluid outlet may also have a regulating effect. In another embodiment, the control valve 15 increases the pressure of the accommodation space 100 through a pressure device.

However, the present invention is not limited to this. The purpose of the control valve 15 is to control the pressure of the fluid in the accommodation space 100. Any way to control the valve 15 for this purpose, such as controlling the total amount of the fluid in the containing space, the unit time inflow of fluid into the containing space, the inflow pressure of the fluid into the containing space, and the volume in the containing space Or, the control valve 15 which simultaneously achieves the above multiple functions is within the scope of the present invention.

In a specific embodiment, the flow system is liquid, gel, or gas, and the cutting line 6 is a metal line. The liquid can be water. A solid or gaseous substance can also be added to the liquid to increase or decrease the fluid damping constant. Solid matter can be silt or dust. The gel state fluid may be a paste. The gas can be air, and the metal wire system includes common wire cutting wires such as copper wire and zinc wire.

In addition, the coil portion 116 can be regarded as a bobbin wound with a sufficient amount of metal wires, so that the cutting wires 6 used for processing all come from the coil portion 116. The coil portion 116 is detachably fitted into the pressure receiving portion 110. When the coil section 116 runs out of the cutting wire 6, the coil section 116 may be removed to replace the coil section 116 with a new one. Alternatively, a wire supply device cooperates with the coil portion 116, and the metal wire sent out by the wire supply device is affixed or wound around the coil portion 116. At this time, the spool 11 can be regarded as a component that delivers the metal wire and generates resistance due to fluid pressure.

In a specific embodiment, the closed container 10 further includes a flow guiding hole 106 and a sealing cover 107. The diversion holes 106 are used for allowing fluid to enter the accommodating space 100. In a specific embodiment, the control valve 15 may be disposed on the diversion hole 106 or corresponding to the outside of the diversion hole 106 to facilitate controlling the flow of fluid into the closed container 10 and the pressure of the fluid in the closed container 10. In another embodiment, a valve is coupled to the outside of the diversion hole 106 to adjust the flow rate of the fluid in and out of the closed container 10, and the control valve 15 is used to control the pressure of the fluid in the closed container 10.

In addition, the sealed container 10 may include a bearing 103, and the spool 11 is coupled to the sealing cover 107 through the bearing 103. The coil portion 116 and the pressure-receiving portion 110 are respectively located on both sides separated by the sealing cover 107 and the bearing 103, and the coil portion 116 outside the sealed container 10 is not directly subjected to the fluid pressure in the sealed container 10. Furthermore, since the coil portion 116 is located outside the closed container 10, the coil portion 116 of the spool 11 can be easily replaced, or the cutting wire on the coil portion 116 can be directly replaced. Furthermore, the closed container 10 may include an oil seal 104. The oil seal 104 is coupled to the sealing cover 107 and surrounds the spool 11. The oil seal 104 is used to prevent the fluid from entering or escaping from the accommodation space 100 via the joint between the spool 11 and the bearing 103 and the sealing cover 107.

Furthermore, the closed container 10 further includes an O-ring 109 and a sealed cup 108. The sealing cup 108 has the above-mentioned guide hole 106, and the sealing cover 107 and the sealing cup 108 are sealed by an O-ring 109 to form the accommodating space 100. The sealing cup 108 and the sealing cover 107 are also detachably combined, so the components of the pressure receiving part 110 in the accommodation space 100 can be replaced. Furthermore, since the sealing cup 108 and the sealing cover 107 are detachably combined, other components can be added to the sealing cup 108 or replaced with different built-in sealing cups 108 to generate accommodation spaces with different geometries. In one embodiment, the geometry of the accommodating space 100 can also be controlled by the control valve 15. Further, a part or all of the control valve 15 may be located in the accommodation space 100 to adjust The size of the geometric shape of the accommodation space 100.

Please refer to FIGS. 3, 4, 5A and 5B. FIG. 3 is a schematic diagram of a spool 11 according to a specific embodiment of the present invention. FIG. 4 is a schematic diagram showing another angle of the spool 11 according to a specific embodiment of the present invention. FIG. 5A is a plan view of the pressure receiving portion 110 as viewed from one end remote from the transmission shaft 111. FIG. 5B is a plan view of the pressure receiving portion 110 as viewed from the end of the transmission shaft 111. In a specific embodiment, the pressure receiving portion 110 may be a disc type. In another specific embodiment, the fluid-type wire tension control mechanism 1 further includes a disc disposed on the pressure receiving portion 110 of the spool 11, and the disc is used to withstand the pressure exerted by the fluid. The larger the area of the disc, the greater the damping force it will bear. The pressure receiving part 110 and the coil part 116 of the wire feeding shaft 11 are connected and driven by a transmission shaft 111.

In another specific embodiment, the pressure receiving portion 110 may be provided with other non-disk-type objects, such as objects of other shapes, objects with fan blades, or objects with roughened surfaces.

The pressure receiving portion 110 in FIGS. 5A and 5B may be a disk-shaped pressure receiving portion 110 or a disk-shaped pressure receiving portion 110. To calculate the fluid damping force, the total surface area of the pressured portion 110 needs to be known first. When the diameter of both sides of the disc is the same and the thickness is uniform, the first area A1 is the area of the first surface of the disc, and the second area A2 is the area exposed by the second surface of the disc corresponding to the first surface. The third area A3 is the area of the side of the disc. The total surface area A is the sum of the first area A1, the second area A2, and the third area A3. In FIG. 5A, the first area A1 is π × R _{s 1} ² . In FIG. 5B, the second area A2 covered by the oblique line is π × ( R _{s 1} ² - R _{s 2} ² ). Therefore, the total surface area that the disc can contact with the fluid is A = π (2 R _{s 1} ² - R _{s 2} ² ) + 2π R _{s 1} . t _s

Among them, A is the total surface area (mm ² ) of the pressure receiving section 110, R _s1 is the disk radius (mm) of the pressure receiving section 110, R _s2 is the shaft radius (mm) of the transmission shaft 111, and t _s is the pressure receiving section 110 disc thickness (mm). In another embodiment, a part of the surface area of the transmission shaft falling in the accommodating space 100 must also be added up to the total surface area A.

The total surface area A is then used to calculate the fluid damping force experienced by the disc. The formula is as follows: F _d = μ × P × A

Among them, F _d is the fluid damping force (N), μ is the fluid damping constant, and P is the fluid pressure (MPa).

When the cutting wire 6 receives a tensile force caused by a fluid damping force, a force opposite to the wire feeding direction is generated to the coil portion 116. The greater the fluid pressure, the greater the fluid damping force generated. At this time, the moment generated by the radius and the wire tension of the coil portion 116 is equal to the moment generated by the radius and the damping force of the spool 11, as shown in the following formula: F _d × R _{s 1} = ( T _w - F _f ) × R _b

F _d is the fluid damping force (N) calculated earlier, T _w is the line tension of the cutting line 6, F _f is the bearing rotational friction force of the fluid line tension control mechanism 1, and R _b is the radius of the coil portion 116. The strength of the wire tension can be calculated from the known fluid damping force, the radius of the disc of the pressure receiving section 110, the radius of the coil section 116, and the friction force of the fluid type wire tension control mechanism.

Please refer to FIG. 1 and FIG. 6. FIG. 6 is a schematic diagram of a fluid type thread tension control mechanism 1 according to a specific embodiment of the present invention. In a specific embodiment, the fluid-type thread tension control mechanism 1 further includes a take-up spool 16 for receiving the cutting wire 6 sent from the coil portion 116 of the spool 11. Among them, the feed shaft 11 is used to control the tension of the cutting line 6, and the take-up shaft 11 is used to control the moving speed of the cutting line 6.

In a specific embodiment, the fluid-type thread tension control mechanism 1 further includes a plurality of thread-feeding shafts 11. The plurality of feeding shafts 11 form an array and are parallel to each other, and the plurality of feeding shafts 11 can send out and control the tension of the cutting line 6 respectively, and a plurality of winding shafts 16 respectively receive different cutting lines 6. In addition, since the plurality of spools 11 are coupled to a single closed container 10, sufficient fluid damping force can be generated for each spool 11 at the same time without additional fluid volume or fluid pressure. Therefore, the present invention can achieve the effect of reducing energy consumption. In another specific embodiment, one take-up shaft 16 can also be used to receive the cutting lines sent by the plurality of feed shafts 11.

In a specific embodiment, if the thread tension required by each cutting line 6 is different, the discs of the pressure receiving portion 110 of each of the spools 11 with different areas can be replaced respectively, or the pressure of different geometric shapes can be directly replaced. The unit 110 is used to achieve the effect that a single control valve generates different thread tensions.

Compared with the conventional technology, the present invention uses a fluid to apply pressure to a feeding shaft that sends out a cutting wire, so that the feeding shaft generates a rotation resistance. Under the condition that the take-up shaft takes up at a fixed speed, the take-up shaft is subject to a fluid damping force opposite to the direction of the take-up. The greater the fluid pressure, the more obvious the damping effect produced by the spool. Therefore, as the fluid pressure increases, the tension value of the cutting line becomes larger, and the straightness of the cutting line becomes higher accordingly. Because the fluid pressure does not directly act on the cutting line, the cutting line can maintain a stable stream, and the line tension is easy to grasp and control. Since the present invention does not use the solid contact friction to generate resistance, the thread tension control mechanism is less prone to the problem of part wear. Therefore, the fluid thread tension control mechanism of the present invention can maintain stable transmission of the cutting line for a long time, and the cut shape is more precise.

Based on the above detailed description of the preferred embodiments, it is hoped that the features and spirit of the present invention can be described more clearly, rather than the preferred embodiments disclosed above to describe the present invention. The scope is restricted. On the contrary, the intention is to cover various changes and equivalent arrangements within the scope of the patents to be applied for in the present invention. Therefore, the scope of the patent scope of the present invention should be interpreted in the broadest sense according to the above description, so that it covers all possible changes and equal arrangements.

Claims (10)

A fluid-type wire tension control mechanism for adjusting a fluid pressure generated by a fluid to control the tension of a cutting line includes: a closed container having an accommodating space for accommodating the fluid; a control valve, coupled Connected to the closed container to control the fluid pressure generated by the fluid in the accommodating space; and a bobbin passing through the closed container, the bobbin including a pressure receiving portion and a coil portion, the coil portion Interlocking with the pressure receiving portion, the pressure receiving portion is accommodated in the accommodating space, the coil portion is located outside the closed container and sends out the cutting line; wherein the tension of the cutting line is correspondingly applied to the pressure receiving portion One of the fluid pressures is controlled by a fluid damping force; when the cutting line is sent out, the coil part rotates synchronously with the pressure-receiving part, and the relative position of the feeding shaft and the closed container is fixed. The fluid-type wire tension control mechanism described in item 1 of the scope of patent application, wherein the flow system is a liquid or a gas, and the cutting line is a metal wire. The fluid-type wire tension control mechanism described in item 1 of the scope of the patent application, further includes a disc disposed on the pressure receiving part of the wire feeding shaft, and the disc is used to bear the fluid pressure. The fluid type thread tension control mechanism described in item 1 of the scope of patent application, further includes a take-up shaft for receiving the cutting line, wherein the delivery shaft is used to control the tension of the cutting line, and the take-up shaft is used to control The moving speed of the cutting line. The fluid-type wire tension control mechanism according to item 1 of the scope of patent application, wherein the cutting wire is wound around the coil portion, and the coil portion is detachably fitted into the pressure receiving portion. The fluid-type linear tension control mechanism according to item 1 of the scope of the patent application, wherein the closed container has a diversion hole, and the fluid enters the accommodating space through the diversion hole. The fluid-type linear tension control mechanism according to item 6 of the patent application scope, wherein the closed container further includes an O-ring, a sealing cap, and a sealing cup, the sealing cup has the flow guide hole, and the sealing cap and The sealing cup is sealed by the O-ring to form the receiving space. The fluid-type wire tension control mechanism according to item 7 of the scope of the patent application, wherein the closed container further includes a bearing, and the wire feeding shaft is coupled to the sealing cover through the bearing. The fluid-type thread tension control mechanism described in item 1 of the scope of patent application, further includes a plurality of spools, wherein the spools form an array and are parallel to each other, and each such spool is sent out and controlled correspondingly. The tension of the cutting line. The fluid-type linear tension control mechanism according to item 1 of the scope of the patent application, wherein the control valve controls the total amount of the fluid in the accommodating space, the inflow of the fluid per unit time into the accommodating space, and the fluid entering The inflow pressure of the accommodating space or the volume in the accommodating space.