JPS6240129B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a relative translational rotation motion in a celestial orbit within a plane perpendicular to the axial direction of the electrode as it progresses toward the workpiece without rotating the electrode itself. In addition, an inclined surface that can be adjusted according to the amount of machining progress and a lever mechanism that moves relatively on this slope to change the rotation angle increase or reduce the translational rotational motion locus according to the amount of machining progress. The present invention relates to an electric discharge machining apparatus that can perform

In general, this type of electrical discharge machining equipment can not only form a large number of holes in the workpiece that are proportionally large or proportionally small similar to the shape of the electrode, but also allow the electrode itself to undergo relative translational and rotational movement. This technology has many advantages, such as making it easier to remove machining debris and increasing machining speed, and has developed rapidly in recent years. Many of the devices are not only complex, have a large number of parts, and are expensive;
When machining a workpiece with a tapered surface and an arbitrary cross-sectional shape, it is necessary to manufacture an electrode that is completely similar to the machined shape, which has many disadvantages such as extremely high electrode manufacturing costs. It was hot.

This invention has been made with attention to this point, and is a conical ring having the same inclined surface that is constantly pressed in the radial direction by a spring or the like and inscribed in the conical inner cylindrical surface of a track guide that can slide parallel to the direction of machining progress. is rotatably supported on an electrode mounting surface plate that is guided so as to be movable in any direction within a plane perpendicular to the direction of machining, and is inscribed in the conical inner cylindrical surface to perform rotational movement. The orbit guide can be moved up and down according to the amount of machining progress by means of an inclined surface that can be adjusted according to the amount of machining progress, and a lever mechanism that moves relatively on this inclined surface and converts it into a rotation angle. It is an object of the present invention to provide an electric discharge machining apparatus in which the similar rotation locus of the electrode mounting surface plate generated by the above-mentioned cam mechanism is increased or decreased.

That is, Figs. 1a, b, and c all show examples of the idea that is the basis of this invention. 1 is a main shaft that performs servo feeding of an electric discharge machine, and 2 is a main shaft that is attached to the tip of this main shaft 1. A frame 3 is a plurality of guide bars formed and arranged inside the frame 2, and is attached parallel to the main shaft 1.
Reference numeral 4 denotes a track guide which is fitted and inserted into the guide bar 3 and held so as to be slidable in the vertical direction, and has a conical inner cylindrical surface 5 formed at its center.
Reference numeral 6 denotes two cross roller guides provided inside the frame 2, which are provided in one direction within a plane perpendicular to the main shaft 1. 7 is a saddle guided by the cross roller guide 6; 8 is another cross roller guide provided on the saddle 7 in a direction perpendicular to the cross roller guide 6; 9 is guided by the cross roller guide 8. It is a rocking body, and a conical ring 11 is rotatably engaged with and held on the outer circumference of the rocking body through a radial bearing 10. The outer peripheral surface of this conical ring 11 is given the same slope as the conical inner cylindrical surface 5, and is configured to be inscribed in the conical inner cylindrical surface 5. Reference numeral 12 denotes a pin that is rotatably engaged with the center of the rocking body 9 and slidable in the vertical direction, and one end of the pin 12 is connected to the link 1 by the pin 14.
3, and this link 13 is connected to pin 15.
It is rotatably coupled to the center of rotation of a fixed rotary shaft 30 which is rotatably supported at the center of the frame 2 parallel to the main shaft 1 . A spring 16 is provided to constantly press the pin 12 in the radial direction. 17 is a spring guide for preventing the spring 16 from falling; 18 is a cavity formed inside the fixed rotating shaft 30 to accommodate the pin 12, the link 13, the spring 16, the spring guide 17, etc.; be. 19 is the fixed rotating shaft 3
Radial bearing that rotatably holds 0, 2
0 is a nut that regulates the fixed rotating shaft 30 in the vertical direction, 21 is a large diameter belt pulley provided at the end of the fixed rotating shaft 30, and 22 is a drive motor 24 fixed to the side surface of the frame 2. This is a small diameter belt pulley that is integrated with the rotating shaft, and is connected to the belt pulley 21 via a belt 23. A spring 25 is provided to constantly press the track guide 4 downward. Reference numeral 26 denotes an electrode mounting surface plate provided at the tip of the oscillating body 9, and is fixed with bolts 27. 28 is an electrode attached to the electrode mounting surface plate 26, 29 is a workpiece, 31 is a rack attached vertically to the side surface of the frame 2, 32 is a pinion that is always engaged with this rack 31, and the shaft It is supported by 33. This shaft 33 is thus supported by the side surface of the frame 2. It is rotatably engaged and held by the mounting plate 34. 35 is 2 provided in the recess of the mounting plate 34.
The movable body 36 is moved to the main shaft 1 by a cross roller guide.
It is provided for guiding parallel to the
Reference numeral 37 denotes an adjustment bar that passes through the center of the movable body 36 and is attached to the tip of a support metal 38 fixed to the side surface of the column. 36a is a screw for fixing the movable body 36 to the adjustment bar 37. Reference numeral 39 denotes an inclined plate that fits into a shaft portion 40 provided on the side surface of the movable body 36 and is fixed with a nut 41. A roller guide 42 is formed on this inclined plate 39. 43 is the rotation scale, 44 is the mounting plate 3
4 serves as a reference position for reading the rotation scale 43. 45 is a roller that is movably guided without any gap in the roller guide 42, 46 is a pin for rotatably supporting this roller 45 on the lever 47, and the lever 47 is fixed to the shaft 33 with a key or the like. The rotation angle thereof is configured to be the same as the rotation angle of the pinion 32. If the roller guide 42 is vertical and not tilted, the lever 47 will not rotate even if the main shaft 1 descends, but if the roller guide 42 is tilted at a predetermined angle as shown in FIG. In this case, when the main shaft 1 descends, the lever 47 inevitably rotates and the pinion 3
2 also rotates, so the orbit guide 4 is moved upward or downward. Therefore, the vertical movement of the conical ring 11 is restricted by the mutually inscribed conical ring 11 and the conical inner cylindrical surface 5, and movement in a plane perpendicular to the machining progress direction is not possible, so that relative Slip occurs and the spring 16
The conical ring 11 moves along a line connecting the tangent of the inscribed portion and the center of rotation, or by the elastic force of the spring 16.
That is, as shown in FIG. 1a, the amount of eccentricity e between the main shaft 1 and the conical ring 11 can be adjusted. Needless to say, the plane in which the link 13 rotates and the direction in which the spring 16 is pressed,
And the tangent between the conical link 11 and the conical inner cylinder surface 5 is
Needless to say, they are configured to intersect within the same plane and parallel to the rotation center line of the fixed rotating shaft 30.

As described above, when performing electrical discharge machining, the electrical discharge machining apparatus of the present invention performs relative translational rotational motion between the electrode and the workpiece in a plane perpendicular to the axis along which the electrode moves while machining the workpiece. First, when the fixed rotating shaft 30 is rotated at a predetermined number of rotations by the drive motor 24, the pin 1 disposed in the cavity 18 is rotated by this rotation.
2. The link 13 etc. also rotate together, but since this pin 12 and link 13 are always biased in the radial direction by the spring 16, the rocking body 9 engaged with this pin 12 also rotates. Similarly, the conical ring 11 that is pressed in the radial direction and rotatably engages with the conical inner cylindrical surface 5
touch each other. In other words, as shown in FIG. 1a, the balance is achieved at a position where the center is shifted by the amount of eccentricity e. As described above, this eccentricity e can be adjusted by rotating the pinion 32, and can be changed according to the amount of vertical movement of the main shaft 1 within the range of the vertical stroke of the track guide 4. It is possible. In addition, since the oscillator 9 can be moved linearly to any position relative to the frame 2 within a plane perpendicular to the processing direction, the oscillator 9 can move in a 360° direction as the fixed rotating shaft 30 rotates. 9 will continue to be pushed, the conical ring 11 will roll using the conical inner cylindrical surface 5 provided at the center of the orbit guide 4 as a guide, and the rocking body 9 will not rotate itself with the eccentricity e as the radius of rotation. This results in a translational and rotational motion that traces a circular trajectory similar to a celestial orbit. Also, as the machining progresses, the main shaft 1 moves downward, and the roller 45
is guided by the roller guide 42 and slides downward. At this time, the lever 47 is rotated by the roller guide 42, causing the pinion 33 to rotate. When the pinion 33 rotates in this manner, the rack 31 that meshes with it moves upward or downward to control the elevation of the track guide 4.
The controlled amount of the orbit guide 4 is proportional to the amount of movement of the main shaft 1, and the amount of change can be further controlled by the inclination angle of the inclined plate 39. In other words, as mentioned above,
It becomes possible to increase or decrease the rotation radius of the electrode 28, which is guided by the conical inner cylindrical surface 5 and performs a translational rotation motion drawing a circular locus, in accordance with the amount of descent of the main shaft 1, as shown in FIG. 1a. As shown, it is possible to process a tapered surface using a simple shaped electrode 28. Furthermore, if the movable body 36 is fixed at an arbitrary position on the adjustment bar 37,
The starting point of the tapered surface can be set at any position. Further, by adjusting the roller guide 42 to a vertical position, it is possible to machine a straight hole. In addition, the eccentricity e is set to "0".
In this case, the fixed rotating shaft 3
If the conical ring 11 and the conical inner cylindrical surface 5 are arranged so that they fit together without any gap at the position where the center of the pin 12 coincides with the rotation center line of the Needless to say, the electrode mounting surface plate 26 remains stationary without being transmitted.

Note that FIGS. 2a, b, and c show other examples of the idea that is the basis of this invention. In this embodiment, the fixed rotating shaft 30 is separated from the axis of the main shaft 1 by a distance "L" It is rotatably supported within the frame 2 by an angular bearing 50 and a thrust bearing 51. And this rotating shaft 30
An eccentric rotating shaft 52 is movably supported at the upper end via a cross roller guide 53 so as to be slidable in one direction intersecting the center of rotation of the fixed rotating shaft 30 in a plane orthogonal to the processing direction.
Moreover, this eccentric rotating shaft 52 is always biased in the radial direction by the spring 16, and
A conical ring 11 is rotatably attached to the upper end thereof and is secured by a nut 54.
Further, this conical ring 11 is arranged parallel to the direction of machining progress, and is configured to come into contact with the conical inner cylindrical surface 5 of the track guide 4, which is prevented from rotating by a key 55 and is supported so as to be slidable in the vertical direction. There is. This track guide 4 has a spring 25
is always urged upward, and its elastic force can be adjusted using the adjustment bolt 56. Reference numeral 57 denotes a roller that comes into contact with the upper surface of the adjustment bolt 56, and is rotatably supported by the lever 47 by a pin 58, and this lever 47 is rotatably supported by the mounting bracket 60 by a pin 59. Furthermore, a roller 45 that rolls into contact with the inclined plate 39 and is constantly pressed against the inclined plate 39 by the elastic force of the spring 25 is rotatably pivoted to the other end of the lever 47 by a pin 46. ing. 61 is a pinion formed in the semicircular portion of the inclined plate 39, and a sector gear 62 is always engaged with the sector gear 61; 63 is a shaft that rotatably supports the pinion 62, and is attached to the mounting plate 34. . 64 is a connecting rod, and 65 is a ball guide that is movably supported by the frame 2 via the cross roller guide 8 in a direction perpendicular to the connecting rod 64 and that supports the connecting rod 64 so as to be slidable in its axial direction. , 66 are ball bearings for rotatably connecting the eccentric rotating shaft 52 and one end of the connecting rod 64. The other end of the connecting rod 64 is non-rotatably connected to the electrode mounting surface plate 26, as shown in FIG. 2b. 67 is a bearing case provided inside the frame 2, and 68 is a plate with smooth surfaces, which is attached to the shaft 70 with a nut 69 inside the bearing case 67. 71 is the above plate 6
8 and a bearing case 67. The balls 71 can be smoothly moved to any position within the plane of the plate 68 without any gaps, and can also be moved in the vertical direction. This was provided to prevent the "backlash" of the Numeral 72 is a nut for attaching and fixing the electrode mounting surface plate 26 to the shaft 70.

The operation of the other example of the idea that is the basis of this invention described above is almost the same as that of the example described above (FIG. 1), but one end of the connecting rod 64 supported by the ball guide 65 is Since it is rotatably supported by the eccentric rotating shaft 52, even if it rotates while maintaining the rotation radius e shown in FIG.
is obtained by reciprocating motion with an amplitude of "2e" on two parallel and orthogonal axes in a plane perpendicular to the processing direction, and this rotary reciprocating motion rotates the electrode mounting surface plate 26 itself. It is possible to convert the motion into a translational rotational motion that draws a circular locus in the shape of a celestial orbit with a radius of e without causing any movement. In addition, in such a configuration (FIG. 2), as shown in FIG. Figure 1)
It has the advantage that it can be constructed smaller than the previous one, and there is no relative restriction on the height of the electrode and the workpiece.

However, in the above-described example of the other concept of the present invention, the inclined plate 39 and the mounting plate 34 adjust the rotation radius e according to the amount of downward movement of the main shaft.
is designed to be attached to the side of the column, but this is not preferable in terms of mounting, and it is more desirable to attach it to the frame 2. This problem has been solved in the example shown in FIG. 3 which shows still another concept of the present invention. In this FIG. The roller 45 is guided and supported on the side in parallel with the main shaft 1, and the movement of a roller 45 rolling on an inclined plate 39 is transmitted to the track guide 4 via a lever 47.
80 is a scale ring provided at the shaft end of the fixed rotating shaft 30, 81 is a clamp device for preventing rotation of this scale ring 80, and 82 is a peripheral edge of the scale ring 80 screwed into this clamp device 81. The tightening bolt 83 that is crimped is an index and serves as a reference for reading the scale of the scale ring 80. In the device configured as described above, for example, the rotation of the drive motor 24 is stopped, the scale ring 80 is set at a predetermined angle, and the scale ring 80 is clamped with the tightening bolt 82. Next, since the eccentric rotating shaft 52 is pressed by the spring 16 in the direction of the positioned angle, the center of the fixed rotating shaft 30 and
Eccentric rotating shaft 5 only on the straight line connecting the direction of the above angle
2 slides are possible, and this is done by the vertical movement of the track guide 4. That is, if the fixed rotation shaft 30 is clamped as shown in FIG. This makes it possible to control feeding of the electrode 28 in the Z-axis (center line in the direction of machining progress). This means that it is possible to process the workpiece by moving the electrode closer to the workpiece only in a certain arbitrary direction.

An example of the idea that is the basis of this invention described above (Figure 1) and other examples (Figures 2 and 3)
In this case, the relative relationship between the electrode and the workpiece in a plane perpendicular to the direction of machining progress is such that the movement of any point on the outer circumference of the electrode cut parallel to the plane increases the eccentricity e. This is a relationship that results in motion that describes a complete circular locus with the radius. This means that when machining is performed using an electrode of a certain shape, the machining holes of the workpiece to be machined are shaped according to the shape of each outer circumferential portion of each cut plane parallel to the plane perpendicular to the machining progress direction of the electrode. This means that they are always similar to each other, and are proportionally larger or smaller. That is, the machined hole has a drawback that it has a similar shape to the shape of the electrode.

Figures 4a, b, and c show an embodiment of the present invention that solves this problem.A single electrode is used to cover a machined hole having an inclined surface of any shape other than a shape similar to this electrode. It is intended to be formed into a workpiece.

That is, in Figure 4 a, b, c, 100
101 is an oval-shaped cam attached to the shaft end of the fixed rotating shaft 30, and 101 is a roller that rolls on the outer periphery of this cam 100 and is rotatably pivoted to a shaft 103 by a pin 102. A roller 106, which is slidably supported by a guide arm 104 projecting from the frame 2 and rotatably attached to its tip by a pin 105, engages with and presses the arm 107. There is. One end of the arm 107 is constantly pushed upward by the spring 25 and is always engaged with the upper surface of the bevel gear 108 that is screwed into the track guide 4.
It is swingably supported by a pin 110 on a protrusion 109 of the frame 2 . Therefore, cam 10
It is possible to accurately transmit the swing motion of the shaft 103 that occurs with the rotation of the shaft 103 to the orbit guide 4. Reference numeral 111 denotes a roller that is in constant pressure contact with the upper surface of the bevel gear 108, and is connected to the arm 10 by a pin 112.
It is pivotally attached to the upper end of 7. Therefore, while the fixed rotating shaft 30 makes one revolution, the orbit guide 4 is displaced up and down according to the shape of the cam 100, and the conical ring 11 that rolls in contact with the conical inner cylindrical surface 5, Since it is pushed in the radial direction by the spring 16, it rotates while following the vertical displacement of the track guide 4. In other words, the eccentric rotating shaft 52 is
It is possible to obtain a proportionally small or proportionally large locus that is completely similar to the outer peripheral shape of the cam 100. 113 is a shaft rotatably fixed to the side surface of the frame 2; 114 is a bevel gear that constantly meshes with the bevel gear 108; the bevel gear is fixed to the shaft 113 via a key or the like; , and the rotation angle of the bevel gear 114 are, of course, equal.

In FIG. 4, which shows one embodiment of the present invention described above, the inclined plate 39 is set in advance at an angle "θ ₁ " as shown in FIG. 4a. In this case, as shown in FIG. 5, it is assumed that the inclination angle of the inner surface of the machined hole 120 is "θ ₂ ". When the drive motor 24 rotates and the main shaft 1 descends to start electrical discharge machining between the electrode and the workpiece, the electrode 28 follows a similar trajectory proportional to the shape of the cam 100, as described above. Process the workpiece while drawing. However, as the main shaft 1 descends, the lever 47 descends along the roller guide 42 of the inclined plate 39, and thus rotates about the shaft 113 as a fulcrum. This rotation angle is synchronized with the bevel gear 114, so the bevel gear 1
08 and raises the track guide 4. Naturally, the radius of rotation of the eccentric rotating shaft 52 that rolls while being inscribed in the orbit guide 4 that moves upward in this way also increases. In other words, the track guide 4 is constantly vibrated in the vertical direction by the cam 100 via the arm 107, but the reference position of this vibration is proportional to the amount of movement of the main shaft upward or downward by the lever 47 and the setting amount of the inclined plate 39. As shown in FIG. 5, an elliptical hole having an inclined surface can be formed using a circular electrode of φD. It goes without saying that even if the cam 100 has a shape other than the elliptical shape described above, by arbitrarily setting the shape of the cam 100, a machined hole having an inclined surface corresponding to the shape can be formed.

As described above, according to the present invention, while performing relative translational rotational movement between an electrode and a workpiece in electric discharge machining, control is performed to increase or decrease the rotational radius according to the amount of movement of the main shaft. This has the effect of significantly increasing the range of electrical discharge machining possible with a single electrode. Further, according to the present invention, the number of parts is extremely reduced compared to conventional electric discharge machining apparatuses of this type, and the structure is simplified. In addition, the amount of change in the eccentric radius can be adjusted arbitrarily by simply changing the angle of the inclined plate, and can be adjusted according to the amount of movement of the electrode during machining using a lever with a simple mechanism that engages the inclined plate and the orbit guide at both ends. Since the amount of eccentricity is changed by adjusting the vertical position of the track guide, it is possible to provide accurate translational rotational motion with little play. Further, according to the present invention, a thin device is provided in which a part that guides and supports the electrode mounting surface plate and a component part that gives translational rotational motion to it and controls its orbital radius can be separated. This also has the effect that there is no restriction on the height between the electrode and the workpiece. Furthermore, according to the present invention, by using the cam mechanism, the translational rotation trajectory of the electrode mounting surface plate can be controlled to a proportionally small or proportionally large trajectory that is completely similar to the cam shape, and the amount of descent of the main shaft can be controlled. The radius of rotation can be reduced or increased depending on the situation, and not only can holes with any slope be easily formed, but they can also be machined in any direction without rotating the electrode. , which has many excellent effects.

[Brief explanation of the drawing]

Figures 1a to d show examples of the idea that is the basis of this invention, in which Figure 1a is a longitudinal sectional view, Figure 1b is a sectional view taken along line E--I of Figure 1a, 1c is a sectional view taken along the Ro-Ro line in FIG. 1a, and FIG. 1d is a bottom view of the main part of FIG. 1a viewed from the direction of arrow A. Figures 2a to 2c show examples of other ideas of the present invention, in which Figure 2a is a longitudinal sectional view, Figure 2b is a sectional view taken along the Ha-Ha line in Figure 2a, and Figure 2a is a longitudinal sectional view. FIG. 2c is a side view of the main part of FIG. 2a viewed from the direction of arrow B. 3a to 3e show examples of still other ideas of the present invention, in which FIG. 3a is a longitudinal cross-sectional view, FIG. 3b is a side view of the main part, FIG. 3c is an explanatory diagram of the operation,
FIG. 3d is an overall side view, and FIG. 3e is a plan view. 4a to 4c show still another embodiment of the present invention, in which FIG. 4a is a longitudinal cross-sectional view, and FIG. 4b is a main part of FIG. 4a viewed from the direction of arrow c. bottom view,
FIG. 4c is a side view of the main part, and FIG. 5 is a sectional view showing the relative relationship between the electrode and the workpiece. In the drawing, 1 is a main shaft, 2 is a frame, 4 is a track guide, 5 is a conical inner cylindrical surface, 11 is a conical ring, 24
26 is a drive motor, 26 is an electrode mounting surface plate, 28 is an electrode, 30 is a fixed rotating shaft, 39 is an inclined plate, 47 is a lever, 52 is an eccentric rotating shaft, 100 is a cam, 107
is the arm. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1 A track guide 4 fitted into a frame 2 provided on the main shaft 1 and supported so as to be movable in the same direction as the machining direction of the electrode 28, and a conical inner cylindrical surface 5 provided on this track guide. pressure contact,
A conical ring 11 that moves in a direction perpendicular to the axis of the orbit guide to provide eccentricity, an eccentric rotating shaft 52 that rotatably supports this conical ring, a fixed rotating shaft 30 that movably supports this eccentric rotating shaft, and this conical ring An electrode mounting surface plate 26 connected to the ring 11, a drive motor 24 for rolling the conical ring 11 along the conical inner cylindrical surface 5 of the track guide 4, and a main shaft 1.
A tilted plate 39 is provided at which the angle can be changed, and both ends of the tilted plate engage with the track guide 4 to adjust the vertical position of the track guide in accordance with the amount of movement of the electrode during machining. A lever 47 for changing the amount of eccentricity is provided, and a cam 100 is provided at the end of the fixed rotating shaft 30 to rotate on the same axis, and both ends of the cam 100 engage with the outer circumferential surface of the cam 100 and the orbit guide. An arm 107 is provided that changes the amount of eccentricity by adjusting the vertical position of the orbit guide 4 in accordance with the translational rotation angle of the electrode 28, and provides a relative translational rotational movement in a celestial orbit to the electrode mounting surface plate 26. At the same time, the radius of translational rotational motion is controlled to increase or decrease in proportion to the amount of progress in the direction of machining progress, and an electrode translational rotational trajectory similar to the cam outer circumferential shape is created in accordance with the rotation angle of the cam 100. An electric discharge machining device characterized in that an electrical discharge machining device is provided with an electric discharge machining device.