JP2009166187A - Electric discharge machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep positioning accuracy of an electrode guide while suppressing a manufacturing cost of the electrode guide. <P>SOLUTION: An electric discharge machine is equipped with: a mechanism body 32a including a carrying surface (V block 26n) formed of a section in a predetermined shape; a carrying plate (clamp plate 26d) formed like a plate; a support (hinge shaft 26f) for rotatably supporting the carrying plate at a predetermined point of support on the mechanism body 32a; and an elastic body (coil spring 26k) for urging the carrying plate in a predetermined direction, and with a carrying mechanism 26 for carrying the electrode guide 30 in contact at three or more positions by one of surfaces of the carrying plate urged by the elastic body and the carrying surface. As the carrying surface and the carrying plate can be formed in a simple shape, the manufacturing cost is suppressed. Since the carrying plate is urged by the elastic body, the electrode guide 30 is held even in a liquid. As the guide is in contact at three or more positions, the positioning accuracy is kept. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electric discharge machine including an electrode that intermittently discharges between a workpiece and an electrode guide that guides the electrode toward the workpiece.

  When machining an object, the electric discharge machine intermittently discharges between the object and the electrode, so that not only the object but also the electrode are consumed. Further, not only when the electrode is worn out, the electrode may be exchanged in accordance with a target processing shape or the like. In these cases, if the diameters of the electrodes are different, the electrode guides that guide the electrodes must also be replaced.

Conventionally, an example of a technique in which an upper portion of an electrode guide is configured to be detachable at a lower end portion of a support arm has been disclosed (see, for example, Patent Document 1). Specifically, the pull stud provided in the electrode guide is drawn into the chuck provided in the support arm and is positioned by the positioning surface, the positioning pin, and the positioning plate.
JP-A-9-136222

  According to the technique described in Patent Document 1, the electrode guide needs to be formed in an L shape because it is separated from the electrode from the place where the position of the support arm is adjusted by the guide device. Furthermore, it is necessary to form a pull stud on the electrode guide and to form a chuck on the support arm. Therefore, there is a problem that the manufacturing cost of the electrode guide and the support arm increases.

In order to keep the above manufacturing cost low, it is necessary to simplify the shape of the electrode guide and the support arm. In this case, a mechanism for holding the electrode guide is provided at the tip of the support arm, and the electrode guide is held / released / replaced by a pair of hands formed in a rod shape as described in Patent Document 1 (particularly below) Unless otherwise specified, this is referred to as “holding etc.”).
In order to realize this, a power source (for example, a cylinder or a motor) offset to the outside of the liquid, a control unit for the power source (for example, an amplifier or a solenoid valve), a power transmission mechanism for transmitting power (for example, a cam or a motor) Ball screw etc.) is required. Therefore, the power source and the control unit and the piping and wiring necessary for these are separately required, resulting in high costs, and the presence of the power transmission mechanism impairs the work piece and jig space in the liquid. There's a problem.

  Further, a configuration is conceivable in which the electrode guide is integrated with the support arm, and processing is performed while exchanging each integrated support arm. In this configuration, although it is not necessary to move the processing machine main body or the processing tank to bring the electrode guide out of the liquid, it is necessary to provide the processing machine main body with a clamp mechanism for making the support arm replaceable. In order to realize this, a power source for clamping the support arm, a control unit for the power source, piping, wiring, and the like are required. Therefore, the integrated support arm must be manufactured for each diameter of the electrode guide, which increases the cost, and the position accuracy of the electrode guide is lowered to replace the support arm itself, and the integrated support arm is integrated. There is a problem that a large space is required for replacement and storage as compared with the case where it is not realized.

  On the other hand, when the pair of hands described in Patent Document 1 is used, the electrode guide is held at two locations, but the movement in the direction parallel to the hand is relatively easy. Therefore, there is also a problem that positioning accuracy is inferior simply by holding the electrode guide with a pair of hands.

  The present invention has been made in view of the above points, and it is possible to reduce the manufacturing cost of the electrode guide and the like, hold the electrode guide even in liquid, and further maintain the positioning accuracy of the electrode guide. It aims at providing the electric discharge machine provided with.

(1) Means for solving the problem (hereinafter simply referred to as “solution means”) 1 is as described in claim 1.
According to the solution 1, the holding mechanism holds the electrode guide by contacting at three or more locations by the holding surface of the mechanism main body and one surface of the holding plate. The holding surface of the mechanism main body may be formed so that the cross section thereof has a predetermined shape (for example, a V shape or a planar shape), and the holding plate may be formed in a plate shape. In other words, it is not necessary to form a complicated shape such as a chuck or a pull stud described in Patent Document 1, and it is sufficient to form the surface with a simple shape, so that the manufacturing cost of the mechanism main body and the holding plate can be kept low. Since the holding plate is urged by an elastic body, a power source, a control unit, and the like are not required as components of the holding mechanism, so that the cost can be reduced and the electrode guide can be held even in liquid. Further, since a power transmission mechanism is not required, the workpiece and jig space in the liquid are not damaged. Since one surface of the holding plate and the holding surface make contact at three or more locations, the positioning accuracy of the electrode guide can be maintained.

(2) Solution 2 is as described in claim 2.
According to the solution 2, the holding surface is formed in a V shape and the holding plate is formed in a flat surface. Alternatively, the holding surface is formed as a flat surface, and the holding plate has a V-shaped cross section. In any case, the electrode guide is held in contact with three places. Since such a simple shape and configuration can be realized, the manufacturing cost is the lowest.

  According to the present invention, the manufacturing cost of the electrode guide and the like can be kept low, and the positioning accuracy of the electrode guide can be maintained.

  The best mode for carrying out the present invention will be described with reference to FIGS. Here, FIG. 1 is a front view showing a configuration example of the fine hole electric discharge machine. 2 and 3 show a configuration example of the holding mechanism. FIG. 4 illustrates the holding process. 5 and 6 show a configuration example of the hand mechanism. In addition, directions such as up, down, left, and right are based on the descriptions in the corresponding drawings.

  First, a configuration example of a fine hole electric discharge machine will be described with reference to FIG. The fine hole electric discharge machine 10 is roughly divided into an electric discharge machine main body 12 and a machining control device 14. A configuration example of the electric discharge machine main body 12 will be described later. The processing control device 14 is a device that controls processing such as movement of the processing head 16 and processing by electric discharge, and includes an operation panel 28, a power source, and the like. The operation panel 28 inputs necessary data for moving the machining head 16, machining by electric discharge, etc., and gives control instructions.

  The electric discharge machine main body 12 is a device that processes a workpiece by intermittently discharging between the electrode 18 and the workpiece in accordance with a signal (including electric power) sent from the machining control device 14, and includes a machining head. 16, the electrode 18, the processing tank 20, the mount 22, the intermediate guide 24, the holding mechanism 26, and the like. The electrode 18 is attached to the collet holder 17. The electrode 18 is prevented from shaking by the intermediate guide 24 and is guided toward the workpiece by an electrode guide 30 (see FIG. 2) held by the holding mechanism 26. A processing tank 20 is installed above the gantry 22, and a workpiece to be processed is placed in the processing tank 20.

  A specific configuration example of the holding mechanism 26 will be described with reference to FIGS. 2 and 3. The overall side view is shown in FIG. 2, the plan view taken along the line III-III in FIG. 2 is shown in FIG. 3A, the front view taken along the arrow is shown in FIG. FIG. 3C shows a side view for viewing. In FIG. 3, the description of some elements shown in FIG. 2 (for example, the spraying part 26g) is omitted.

  The holding mechanism 26 shown in FIG. 2 includes a bracket 26a, an electrode rough guide 26b, a clamp plate 26d, a spraying portion 26g, a guide shaft 26h, a coil spring 26k and a mounting stay 26m shown in FIG. In FIG. 2, one end of the bracket 26a is fixed to the plate 16a via the mounting portion 16b. The plate 16a is configured such that movement in the Z-axis direction (that is, the vertical direction in the drawing) can be controlled.

  A first mounting portion 26c and a second mounting portion 26e are branched from the other end of the bracket 26a. An electrode rough guide 26b is fixed to the first mounting portion 26c, and a spraying portion 26g is provided to the second mounting portion 26e. The central axis of the electrode rough guide 26b is arranged so as to coincide with the central axis of the electrode guide 30 held by the clamp plate 26d and the V block 26n. The spraying part 26g sprays the machining liquid sent through the cable 26j toward the workpiece.

  As shown in FIG. 3A and FIG. 3B, the second mounting portion 26e is formed with the V block 26n described above and a coil spring 26k, a clamp plate 26d, and the like. The V block 26 n corresponding to the “holding surface” is a surface such that a partial cross section of the second mounting portion 26 e is V-shaped, and is formed so as to contact the electrode guide 30 at two locations. A guide shaft 26h is fixed to the tip of the mounting stay 26m fixed to the second mounting portion 26e, and a coil spring 26k and a piece 26i are provided in this order through the guide shaft 26h. The coil spring 26k corresponds to an “elastic body”.

  A hinge shaft 26f provided at a predetermined portion of the second attachment portion 26e corresponds to a “support portion”, and a clamp plate 26d is attached thereto. The clamp plate 26d corresponds to a “holding plate”. This clamp plate 26d has a plate-like member formed in an L shape, and rotates as indicated by an arrow D2 with the position where the hinge shaft 26f is provided as a "predetermined support point" as shown in the figure. One surface of the clamp plate 26d comes into contact with the top 26i urged by the coil spring 26k, and the contact surface 26p (corresponding to “one surface”) on the other end presses the electrode guide 30. That is, one end side of the clamp plate 26d is pressed by the elastic force of the coil spring 26k, and the electrode guide 30 is pressed toward the V block 26n from the other end side of the clamp plate 26d with this pressing force.

  As shown in FIG. 3C, the second mounting portion 26 e has a protruding portion 26 ea protruding in a convex shape toward the electrode guide 30. The protrusion 26ea holds the electrode guide 30 by fitting into the recess of the electrode guide 30. In other words, the electrode guide 30 is held by the protrusion 26ea and positioned by the V block 26n and the clamp plate 26d.

  A process of holding the electrode guide 30 conveyed by a hand mechanism (see FIGS. 5 and 6) described later using the holding mechanism 26 configured as described above will be described with reference to FIG. Here, FIG. 4A shows a state before holding. FIG. 4B shows a state in the middle of holding. FIG. 4C shows a state after the holding.

  First, before holding the electrode guide 30, one end side of the clamp plate 26d is pushed by the elastic force of the coil spring 26k. At this time, as shown in FIG. 4 (A), the other part of the clamp plate 26d (that is, the part on the opposite side across the hinge shaft 26f of the support point) stops in a state where it hits the second mounting portion 26e.

  The hand mechanism 32 conveys the electrode guide 30 with the hands 32c and 32d, and moves forward in the vicinity of the holding mechanism 26 along a predetermined path. Along with this forward movement, the wedge stay 32b provided in the hand mechanism 32 pushes the clamp plate 26d, and the clamp plate 26d rotates against the elastic force of the coil spring 26k, so that the V block 26n and the clamp plate 26d There is a gap between them. When the hand mechanism 32 is moved so that the concave portion of the electrode guide 30 fits into the protruding portion 26ea from the gap thus generated, the state is as shown in FIG.

  When the hands 32c and 32d are opened when the state shown in FIG. 4B is reached, the electrode guide 30 becomes free while riding on the protruding portion 26ea. Thereafter, the hand mechanism 32 (specifically, the wedge stay 32b) is moved backward from the holding mechanism 26 so as to be separated from the clamp plate 26d. With this backward movement, the clamp plate 26d is pressed by the contact surface 26p against the electrode guide 30 according to the elastic force of the coil spring 26k. The electrode guide 30 is accurately positioned by the V block 26n and the contact surface 26p by being pressed by the clamp plate 26d. FIG. 4C shows a state where the electrode guide 30 is thus positioned.

  In the above-described example, the case where the electrode guide 30 is held has been described. However, the same can be applied to the case where the electrode guide 30 is released (that is, the holding is released). That is, it is only necessary to move forward while holding the hands 32c and 32d of the hand mechanism 32, hold the electrode guide 30 held, and move it backward. Therefore, the electrode guides 30 having different diameters can be exchanged by alternately performing holding and releasing.

  Here, a configuration example of the hand mechanism 32 described above will be briefly described with reference to FIGS. In FIG. 5, a state where the electrode guide 30 is held is indicated by a two-dot chain line. The hand mechanism 32 shown in FIGS. 5 and 6 has a wedge stay 32b, hands 32c and 32d, an operating part 32e, a driving body 32f, and the like with respect to the mechanism main body 32a.

  The wedge stay 32b serves to push out the clamp plate 26d when the electrode guide 30 is held by the holding mechanism 26 as described above. The hands 32c and 32d hold the electrode guide 30, the collet holder 17, and the like. Specifically, the gripping is performed by moving in the direction of the arrow shown in FIG. 6A, and the gripping is released by moving in the direction of the arrow shown in FIG. 6B. A cylinder (air, hydraulic pressure, or the like) that operates according to a signal sent from the machining control device 14 of FIG. 1 is used as the drive body 32f. The operation part 32e operates opening and closing of the hands 32c and 32d according to the volume or pressure of the fluid sent by the operation of the driving body 32f. By controlling the increase or decrease in the volume or pressure of the fluid, the gripping force and the opening / closing amount can be adjusted.

According to the embodiment described above, the following effects can be obtained.
(1) The holding mechanism 26 is configured to hold the electrode guide 30 by contacting (point contact or line contact) at three locations by the V block 26n and the contact surface 26p (see FIGS. 2 to 4). Since it is sufficient to form a simple shape as apparent from the cross-sectional shape of the V block 26n and the external shape of the clamp plate 26d, the manufacturing cost of the mechanism body 32a and the clamp plate 26d can be kept low. Since the clamp plate 26d is energized by the coil spring 26k, the power source and the control unit and the piping and wiring necessary for them are not required as the constituent elements of the holding mechanism 26. The electrode guide 30 can be held. As described above, since holding or the like can be performed in the liquid, an offset mechanism is not required, and the holding mechanism 26 can be configured in a compact manner. Moreover, since a power transmission mechanism is not required, the workpiece and jig space in the liquid are not damaged, and malfunction due to sludge generated during electric discharge machining can be prevented. Since the contact surface 26p and the V block 26n make contact at three locations, the positioning accuracy of the electrode guide 30 can be maintained. Since the electrode guide 30 is held by the elastic force of the coil spring 26k, the electrode guide 30 can be held or replaced manually without operating the operation panel, and in an emergency (for example, when the air is turned off or the power is turned off). In addition, the electrode guide 30 can be prevented from dropping by securely holding it. The clamp plate 26d (holding plate) is released by using the power of the hand mechanism 32. However, the hand mechanism 32 has a cost in that the release can be realized if a simple shape part (for example, a wedge stay 32b) is provided. Can be kept low.

(2) The V block 26n was formed with a V-shaped cross section, and the clamp plate 26d was formed with a flat surface (see FIGS. 2 to 4). In this way, when the electrode guide 30 is held in contact with the three places, it can be realized with a simple shape and configuration, so that the manufacturing cost is the lowest.

[Other Embodiments]
Although the best mode for carrying out the present invention has been described above, the present invention is not limited to this mode. In other words, various forms can be implemented without departing from the scope of the present invention. For example, the following forms may be realized.

(1) In the above-described embodiment, the present invention is applied to the fine hole electric discharge machine 10 (see FIG. 1). It can replace with this form and can be applied also to other electric discharge machines except fine hole electric discharge machine 10. Even when applied to other electric discharge machines, the same effects as those of the above-described embodiment can be obtained.

(2) The holding mechanism 26 in the above-described embodiment is configured to hold the electrode guide 30 by contacting at three places by the V block 26n and the contact surface 26p (see FIGS. 2 to 4). Instead of this configuration, the electrode guide 30 may be held by contact at four or more locations. Specifically, the cross section of the V block 26n may be formed in another shape (for example, W shape or U shape), or the contact surface 26p may be formed in a shape other than a plane. When the electrode guide 30 is held and held in contact at four or more locations, the positioning accuracy can be maintained in the same manner as in the above-described embodiment.

(3) In the above-described embodiment, the V block 26n is formed with a V-shaped cross section, and the clamp plate 26d is formed with a flat surface (see FIGS. 2 to 4). Instead of this form, the V block 26n may be formed in a flat surface and the cross section of the clamp plate 26d may be formed in a V shape. Even when formed in this way, as a result, the electrode guide 30 is held by contact at three places, and the positioning accuracy can be maintained as in the above-described embodiment.

(4) In the above-described embodiment, the V block 26n and the contact surface 26p are formed as smooth surfaces (see FIGS. 2 to 4). Instead of this form, one or both of the V block 26n and the contact surface 26p may be formed as a non-smooth surface. Furthermore, it is desirable to form the outer peripheral surface of the electrode guide 30 with a non-smooth surface. In this way, rotation of the electrode guide 30 during holding can be prevented by the contact resistance of the non-smooth surface.

(5) In embodiment mentioned above, the coil spring 26k was used as an elastic body (refer FIGS. 2-4). Instead of this form, an elastic body other than the coil spring may be used. Examples of other elastic bodies include rubber, leaf springs, cylinders (air, hydraulic pressure, etc.). Even when another elastic body is used, the clamp plate 26d can be urged, so that a power source, a control unit and the like are not required, and the electrode guide 30 can be held even in liquid.

(6) In the above-described embodiment, a cylinder is used as the driving body 32f (see FIGS. 5 and 6). Instead of this form, another driving body such as a motor may be used. For example, when a motor is used, it is desirable that the operating portion 32e is constituted by a mechanism (for example, a ball screw / nut mechanism or a rack / pinion mechanism) that transmits the driving force of the motor.
Further, instead of the driving body 32f, a fluid (for example, air or oil) is sent from the processing control device 14 of FIG. 1, and the operation unit 32e operates to open and close the hands 32c and 32d according to the volume or pressure of the fluid. Good.
In any form, the electrode guide 30 can be reliably conveyed.

It is a front view showing the structural example of a fine hole electric discharge machine. It is a side view showing the structural example of a holding mechanism. It is a figure showing the structural example of a holding mechanism. It is a figure explaining the process of a holding | maintenance. It is a side view showing the example of composition of a hand mechanism. It is a top view showing the example of composition of a hand mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fine hole electric discharge machine 12 Electric discharge machine main body 14 Machining control device 16 Processing head 16a Plate 16b Mounting part 17 Collet holder 18 Electrode 20 Processing tank 22 Base 24 Intermediate guide 26 Holding mechanism 26a Bracket 26b Electrode rough guide 26c 1st mounting part 26d Clamp plate (holding plate)
26e 2nd attachment part 26ea Protrusion part 26f Hinge shaft (support part)
26g Spraying part 26h Guide shaft 26i Top 26j Cable 26k Coil spring (elastic body)
26m Mounting stay 26n V block (holding surface)
26p Contact surface 28 Control panel 30 Electrode guide 32 Hand mechanism 32a Main body 32b Wedge stay 32c, 32d Hand 32e Actuator 32f Driver

Claims (2)

A spindle that can be rotated by a drive mechanism; a collet holder that is attachable to and detachable from the tip of the spindle; an electrode that is attached to the collet holder; and an electrode guide that guides the electrode toward a workpiece; An electric discharge machine for machining a workpiece by intermittently discharging between the workpiece and the workpiece,
A mechanism main body having a holding surface formed in a cross section of a predetermined shape, a holding plate formed in a plate shape, a support portion that rotatably supports the holding plate at a predetermined support point in the mechanism main body, and a holding plate An electric discharge machine comprising: an elastic body biased in a predetermined direction, and having a holding mechanism that holds an electrode guide by contacting at one or more locations by one surface and a holding surface of the holding plate biased by the elastic body. The electric discharge machine according to claim 1,
An electric discharge machine in which one of the cross sections of the holding surface and the holding plate is formed in a V shape, the other is formed in a flat shape, and is held in contact with the electrode guide at three locations.

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