JPH0536171B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electric discharge machine used for die engraving and the like.

(Prior art and its problems) Generally, as shown in Fig. 6, an electrical discharge machine has a column B standing upright on one end side of a bed A, and a machining head C is arranged above one side of the column B. It is connected to B so that it can slide up and down, and is placed on the processing tank D at the other end of bed A.
In conventional electrical discharge machines, the machining head C only moves up and down directly above the machining tank D and cannot move to the surrounding area. The machining head C gets in the way and cannot be done from directly above the machining tank D, so some of the side plates d1 and d2 that make up the machining tank D are replaced with the other side plates d3 and d4 and the bottom plate d.
5, so that it can be folded and opened freely, and when the workpiece is taken in and out, after draining the machining fluid in the machining tank D, the side plates d1 and d2 are opened as shown by the dashed line in Fig. 1. The workpiece is folded outward and brought to the top of the bottom plate d5 using a crane from the open part, and from there it is pushed and fixed to a position directly below the processing head C, after which the side plates d1 and d2 are closed. The machining fluid was then supplied again. Therefore, the processing tank D became structurally complex and expensive, and additional labor other than actual processing was required, resulting in very poor work efficiency.

(Technical means for solving the problems) In view of the above-mentioned circumstances, the present invention makes it possible to improve work efficiency by eliminating unnecessary labor as much as possible, and to ensure that the machining head is at the required turning position and height position. The purpose is to provide an electric discharge machine that can be held in place and improve machining accuracy.The technical means to achieve this purpose is to have a column with a circular inner circumferential surface that is integrated with the bed. and a rotary shaft body provided integrally with the processing head, and at least the lower end of the rotary shaft body is fitted to the base having a circular inner circumferential surface so as to be rotatable and slidable in the axial direction. At the same time, an elevating drive means is rotatably and axially immovably interlocked with the rotating shaft, and a diaphragm-shaped sliding contact surface on the base side of the sliding surfaces where the base and the rotating shaft come into sliding contact with each other is connected to the rotating shaft. A liner is provided, and a plurality of vertical and horizontal oil grooves extending in the circumferential direction and axial direction are provided on the back side of the liner so as to communicate with each other, and hydraulic pressure is supplied to these oil grooves to bulge and deform the diaphragm-shaped liner. The rotary shaft body is fixed to the base by pressing the rotary shaft body against the sliding contact surface on the rotary shaft body side.

(Example) Examples of the present invention will be described below based on the drawings.

FIG. 1 shows an electric discharge machine according to the present invention. In this figure, 1 is a bed, 2 is a column erected on one end side of the bed 1, and 3 is a column projecting from the upper end of one end of the column 2. The machining head 3 is integrally attached to the tip of the arm 4 and is equipped with a main shaft 5.
It is movable in the axial direction (indicated by Z in the figure), that is, it can be raised and lowered. Reference numeral 6 denotes a machining tank placed on the bed 1 at a position facing the column 2, in which a machining fluid is stored and the workpiece is set in a fixed position while being immersed in the machining fluid. In addition, the processing tank 6 can be moved on the bed 1 in the X-axis direction (indicated by X in the figure) using the handle 7, and in the Y-axis direction (indicated by Y in the figure) by the handle 8. It's summery.

FIG. 2 shows in detail the column 2 of the electrical discharge machine, and particularly shows the turning mechanism and lifting mechanism of the machining head 3. As is clear from this figure, the column 2 includes a hollow cylindrical rotating shaft body 10 that is integrally suspended from the bottom surface of the box-shaped frame body 9.
and a rotating shaft body 10 fixed on the bed 1.
A base 1 having a cylindrical hard hole (circular inner circumferential surface) 11 for rotatably and axially slidably supporting the
2, and a bearing 13 for supporting radial load and thrust load is provided at the lower inside of the rotating shaft body 10.
The nut member 14 is equipped with a ball screw 15 of a hard shaft 15 erected along the axis of the hard hole 11 in the base 12.
A driving tube 17 that is threadedly engaged with a and is inserted into the rotating shaft 10 and rotated by the motor 16.
The motor 16 is fixedly mounted inside the box-shaped frame 9 and operatively connected to the drive tube 17. Therefore, the rotary shaft body 10 can be freely rotated around its axis manually at any height, thereby allowing the arm 4 to rotate freely around its axis.
The machining head 3 can freely rotate around the axis of the column 2 via the column 2. Also, the rotation of the motor 16 causes the nut member 1 to be
4 rotates, and this nut member 14 moves up and down along the hard shaft 15 due to the rotation, and this nut member 1
4, the rotating shaft body 10 moves up and down while sliding on the inner peripheral surface of the hard hole 11 via the bearings 13, 13,
As the rotary shaft body 10 rises and falls, the processing head 3 moves up and down integrally with the rotary shaft body 10 via the arm 4. In this way, the elevating and lowering drive means 14 to 17 are fixed to the rotating shaft body 10 in the axial direction, that is, the rigid shaft 1
A nut member 14 that is screwed into the nut member 14, a driving tube 17 that integrally connects the nut member 14, and a motor 16 that rotationally drives the nut member 14 are fixedly connected to the rotating shaft body 10 in the axial direction. Rotating shaft pair 10
The rotating shaft body 1 is
0 is connected to the lifting drive means 14 to 17 so as to be rotatable relative to each other, more specifically, to be rotatable at any position of the lifting/lowering movement of the rotary shaft body 10. The base 12 is formed into a prismatic shape and has a hard hole 11 in its center, and this base 12 is a short prismatic base on a mounting base 18 installed on the bed 1. The base receiving part 19 is mounted and fixed on a receiving part 19, and a cylindrical hole part 20 corresponding to the hard hole 11 of the base 12 is formed in this base receiving part 19.

The rotating shaft body 10 constituting the column 2 is fixed to the base 12 at any rotational position by a locking device 21. As shown in FIGS. 2 to 4, this locking device 21 is attached to the base 1 in advance.
2 is made of a rigid body such as cast steel, and a part in the circumferential direction of the inner circumferential surface (sliding surface on the base side) of the cylindrical hard hole 11 that comes into sliding contact with the rotating shaft body 10,
A diaphragm-shaped liner 22 with an arcuate cross section made of an elastic body with a lower elastic modulus (that is, larger deformation with respect to a given load) is embedded over the entire length of the hard hole 11, and the inner peripheral surface of the hard hole 11 is covered with a diaphragm-shaped liner 22. , is divided into a rigid inner circumferential surface part 23A and an elastic inner circumferential surface part 23B that face each other, and oil grooves 24a, 24b, etc. as hydraulic pressure supply parts are provided on the back side of the diaphragm type liner 22, that is, on the outer surface side. Arrange horizontally and vertically. In this case, the rigid inner circumferential surface portion 23A forms a rigid guide portion that supports and guides the rotating shaft body 10 in an inelastic manner, and the liner portion of the liner 22 where the oil grooves 24a..., 24b... are not provided is a cylindrical portion. It is supported in contact with the inner circumferential surface of the hard hole 11, and forms a rigid guide section that cannot be elastically deformed like the rigid inner circumferential surface section 23A.

When hydraulic pressure is supplied to these oil grooves 24a..., 24b..., the diaphragm liner 22
The elastic inner circumferential surface portion 23 of the inner circumferential surface of the hard hole 11 is the inner surface of the hard hole 11.
B locally bulges and deforms inwardly along each of the vertical and horizontal oil grooves 24a and 24b, and comes into pressure contact with a part of the outer circumferential surface of the rotating shaft body 10, and the rotating shaft body 10
The other outer peripheral surface portion of the rigid hole 11 is connected to the rigid inner peripheral surface portion 23A of the hard hole 11.
The rotating shaft body 10 is thereby fixed at an arbitrary rotational position.

Therefore, when the rotating shaft body 10 is slid in the axial direction, that is, in the vertical direction, along the base 12 having a circular inner circumferential surface to hold and fix the machining head 3 at a required height position, the inside of the base 12 is The lower end of the rotary shaft 10, which is fitted into the hard hole 11 and slides into the rigid inner peripheral surface 23A and the elastic inner peripheral surface 23B of the hard hole 11, extends over almost the entire area of the hard hole 11 in the vertical direction. That is, regardless of whether the hard hole 11 is located in the lower region, middle region, or upper region of the inner peripheral surface, the rigid guide portion formed by the rigid inner peripheral surface portion 23A and the liner 22
The position in the direction perpendicular to the axial direction is always restricted by the rigid guide portion formed by the liner portion where the oil grooves 24a, 24b, etc. , it is securely fixed to the base 12 without wobbling.

The diaphragm-shaped liner 22 is made by bending a rectangular steel plate (for example, S20C) with a predetermined curvature into a circular arc (particularly a fine arc) shape. The liner 22 is embedded in a recessed part 25 previously formed on the inner peripheral surface thereof to correspond to the cross-sectional shape of the liner 22, and both upper and lower ends of the embedded liner 22 are fixed to the base 12 by welding. ing. This recessed step 25
The oil grooves 24a..., 24b... are formed so as to intersect vertically and horizontally and communicate with each other on the inner surface of the oil groove,
In addition, oil grooves 24a and 24b are provided at the lower end of the base 12.
An oil introduction hole 26 for introducing pressure oil is provided at the upper end, and an air vent hole 27 is provided at the upper end. Further, the inner diameter of the hard hole 11 substantially formed by the rigid inner circumferential surface portion 23A and the elastic inner circumferential surface portion 23B is slightly larger than the outer diameter of the rotating shaft body 10 of the column 2, and the rigid inner circumferential surface 23A has a high The finishing process is performed with precision, and an accurate perpendicularity to the lower mounting surface 12a of the base 12 is obtained. The lower mounting surface 12a of this base 12 is engaged with the receiving surface 19a of the base receiving part 19, and this receiving surface 19a is in contact with the workpiece support surface (not shown) in the processing tank 6. Therefore, according to this locking device 21, as long as the rigid inner circumferential surface 23A of the hard shaft hole 11 and the main axis 5 of the machining head 3 are parallel, any rotational position of the rotary shaft body 10, In other words, the perpendicularity of the main shaft 6 to the workpiece can be reliably obtained in any pivoting position of the machining head 3. The oil introduction hole 26 is connected to a hydraulic unit (not shown) via a pipe 28, and the air vent hole 27 is closed after air is vented.

In this embodiment, a diaphragm-shaped liner with an arcuate cross section is provided in a part of the inner peripheral surface of the hard hole 11 of the base 12 in the circumferential direction, but a cylindrical diaphragm-shaped liner is provided over the entire inner peripheral surface of the hard hole 11. It may also be provided.

In FIG. 2, reference numeral 29 denotes a dustproof cover having a rectangular cylindrical bellows structure, and a circular outward flange member 30a attached to the upper end of this cover 29 has a
The cover 29 is engaged with a circular inward flange member 30b attached to the lower part of the box-shaped frame 9 so as to be relatively rotatable, and the lower end of the cover 29 is fixed to the lower end of the base 12. Reference numeral 31 in FIGS. 3 and 4 denotes a bolt insertion recess provided at a corner of the prismatic base 12, through which a bolt insertion hole 31a drilled at the bottom of the recess 31 is inserted. Then, a base mounting bolt (not shown) is screwed into the base receiving part 19.

FIG. 5 shows an embodiment of an electric discharge machine equipped with a plurality of machining tanks.
6A and a second machining tank 66B (a third machining tank 66C may also be provided), and when the machining head 63 finishes machining in the first machining tank 66a, the machining head 63 is moved to the column 62. By rotating the machine around the center and moving it directly above the second processing tank 66b, processing can be performed immediately in the second processing tank 66B. Therefore, according to this, processing can be performed in one processing tank. While processing is in progress, workpieces can be taken out or set in other machining tanks, and machining fluids can be replaced, etc., which greatly improves work preparations and greatly improves work efficiency.

(Effects of the Invention) Since the electric discharge machine of the present invention is configured so that the machining head can rotate around the column, the machining head must be rotated when putting the workpiece into or taking it out from the machining tank. If the workpiece is moved to an appropriate distance from the top of the tank, the workpiece can be taken in and out from directly above the tank, and the side plate of the processing tank can be opened like in a conventional electric discharge machine. This eliminates the need for a new structure, and therefore eliminates the need to take in and out the machining fluid.As a result, the structure of the machining tank can be simplified and manufactured at low cost, as well as eliminating unnecessary labor and improving work efficiency. There is an effect that can be achieved. In addition, the machining head has a structure that allows it to be raised and lowered together with the rotating shaft that makes up the column, which simplifies the structure of the machining head, provides a wider field of view for the workpiece, and significantly reduces the weight of the machining head. As a result, the deflection occurring in the main shaft of the machining head can be minimized and accuracy can be improved.

Furthermore, since the electric discharge machine of the present invention is equipped with a rotating shaft body locking device, the machining head can be locked at any rotation angle position while being held at a required height position by manual lifting/lowering drive. .

In particular, this locking device is provided with a diaphragm-shaped liner on the base-side sliding contact surface of the sliding contact surfaces where a base having a circular inner circumferential surface and a rotating shaft fitted thereto are in sliding contact with each other. A plurality of vertical and horizontal oil grooves extending in the circumferential direction and the axial direction are provided on the back side so as to communicate with each other, and hydraulic pressure is supplied to these oil grooves to bulge and deform the diaphragm-shaped liner to form a sliding contact surface on the rotating shaft side. In this case, instead of providing an oil chamber on the entire back side of the diaphragm liner, multiple oil grooves extending linearly in the circumferential direction and the axial direction are provided. Therefore, when hydraulic pressure is supplied, the entire diaphragm does not deform elastically, but only the parts corresponding to each oil groove are elastically deformed, and the parts without these oil grooves come into contact with the sliding surface on the base side. It forms a supported part that cannot be elastically deformed, that is, a rigid guide part, and therefore the rotating shaft body is slid in the axial direction (vertical direction) along the liner to hold the processing head at the required height position. In this case, the lower end of the rotating shaft that is in sliding contact with the liner covers almost the entire area in the vertical direction within the liner.
In other words, regardless of whether it is located in the lower region, middle region, or upper region within the liner, the position in the direction perpendicular to the axial direction is regulated by the rigid guide portion that cannot be elastically deformed. With the position in the direction perpendicular to the axis being controlled by levers, the liner portions corresponding to the vertical and horizontal oil grooves to which hydraulic pressure is supplied are locally bulged and deformed to come into pressure contact with the sliding surface on the rotating shaft side. Therefore, the rotating shaft body is securely fixed to the base without causing lateral runout, that is, center runout, or rattling. Therefore, the machining head can be securely and firmly fixed in place during electrical discharge machining.
It is possible to improve processing accuracy.

[Brief explanation of the drawing]

Fig. 1 is an overall schematic perspective view of an electric discharge machine showing an embodiment of the present invention, Fig. 2 is an enlarged vertical cross-sectional view of a column portion of the electric discharge machine shown in Fig. 1, and Fig. 3 is a lock of the rotating shaft of the column. FIG. 4 is a longitudinal cross-sectional view showing the device, FIG. 4 is a cross-sectional view taken along the - line in FIG. FIG. 1...Bed, 2...Column, 3...Processing head, 6...Processing tank, 10...Rotating shaft body, 11...
Hard hole, 12... Base having a circular inner peripheral surface, 21...
...Lock device, 22...Diaphragm type liner, 24a, 24b...Oil groove.

Claims (1)

[Claims] 1. In an electric discharge machine in which a column is erected on a bed, a machining tank is placed thereon, and a machining head is connected to an upper part of one side of the column, the column is installed on a circular inner periphery integral with the bed. Consisting of a base having a surface and a rotating shaft provided integrally with the processing head, at least the lower end of the rotating shaft is rotatable relative to the base having a circular inner circumferential surface and slidable in the axial direction. Fitting and supporting the rotary shaft body, and rotatably and axially immovably connecting an elevating drive means to the rotary shaft body;
A diaphragm-shaped liner is provided on the base-side sliding contact surface where the base and rotating shaft come into sliding contact with each other, and the back side of the liner has a plurality of vertical and horizontal strips extending in the circumferential direction and the axial direction. The rotating shaft body is fixed to the base by providing oil grooves so as to communicate with each other and supplying hydraulic pressure to these oil grooves to bulge and deform the diaphragm-shaped liner and press it against the sliding surface on the side of the rotating shaft body. An electrical discharge machine characterized by: