KR100355911B1 - Numerically controlled grinding machine for grinding preferably metallic work pieces, in particular, tools - Google Patents

Abstract

Numerically controlled grinding machines for grinding metal workpieces, in particular tools, are provided in a torsionally rigid portal 9 with a horizontal bridge 11 and two side stands 10 extending at a constant distance above the device bed 1. With a fixedly connected device bed 1, a grinding spindle carrier 20 is adjustablely mounted along the first axis-y on the bridge. The device bed 1 is configured to protrude from one side of the portal 9.

Description

Numerically controlled grinding machine for grinding preferably metallic work pieces, in particular, tools}

Purpose of the Invention

The present invention relates to a numerically controlled grinding machine for grinding metal workpieces, in particular tools. This numerically controlled grinding machine is provided with a device bed, a grinding spindle carrier having at least one driven grinding spindle with at least one grinding wheel at one end, and a device bed in the operating range of the grinding wheel (s) of the grinding spindle carrier. Program control adjustments associated with the workpiece spindle and / or the workpiece carrier arranged to impart an adjustment movement in the form of longitudinal and rotational movements, respectively, with respect to the individual axes, the workpiece carrier being arranged and adjustable at the same time along at least one axis. Comprising a device, said grinding spindle carrier can be adjusted via bearings and guide means associated with respect to the device bed along at least two axes installed at right angles to each other and also pivoted on at least one axis in accordance with a given situation. ) Exercise is possible.

The technical field to which the invention belongs and the prior art in that field

Rotary workpieces, for example milling cutters, drills and circular broaching tools, flat workpieces, for example turning chisels, flat broaching tools, stamps, special tools with cutters and special tools without cutters, and other grinding Program-controlled grinding machines to grind possible manufacturing parts require high flexibility to be able to perform all the grinding operations on the workpiece with as little clamping of the workpiece as possible. Known tool grinding machines designed for grinding the above-mentioned workpieces, for example grinding machines disclosed in European patent A1 0 072 887, belong to a so-called columnar design. Here a vertical column with at least one grinding spindle carrier is arranged on a substantially box-shaped device bed adjacent to a workpiece carrier which can be adjusted with respect to several translational axes of rotation and axis of rotation. The column can be adjusted with respect to the workpiece carrier along the translational axis of movement relative to its part and is rotatable about the vertical axis, ie each grinding spindle carrier is pivotally mounted to the column.

While these grinders have proven their practicality in practice, they involve relatively high technical costs because of the principles on which they are based. In addition, the free space available in the apparatus machining area for certain apparatus machining operations and workpieces is greatly limited. In particular, this is because the column must have a fairly large diameter in view of the necessary stability and therefore the grinding spindle must be jutting-out. The result is a relatively long adjustment path for the grindstone wheel during a particular grinding operation in order to place the grindstone wheel in the correct spatial position for each grinding operation. This condition also increases the length of the grinding spindle, which is not already required in terms of space and support conditions.

In particular, in the construction of large apparatus, so-called portal grinding machines which are preferably used for flat grinding operations in large workpieces are already known in various embodiments. In the portal grinding machine, the portal is usually installed so as to be displaceable with respect to the device bed with the workpiece clamping device, and the work platform or the like has the necessary access to the workpiece and the tool. These devices are not designed for machining relatively small workpieces and especially tools with complex cutting forms. A portal grinding machine with a device for exchanging whetstone wheels and an operating platform for walking at the height of the workbench is disclosed in German Patent No. 35 32 903.

Accordingly, an object of the present invention is a program-controlled grinding machine for grinding small metal and non-metal workpieces, in particular tools, which has a large working area and high adaptability and is characterized by narrow space requirements and high strength with good dynamic properties and high efficiency. To provide. The nonmetallic workpiece may be, for example, a ceramic workpiece composed of Al ₂ O ₃ , Si ₂ N ₄ or others.

In order to achieve the above object, the grinding machine mentioned at the outset is, according to the invention, a horizontal bridge, in which a rigid, torsion-free rigid portal is connected to and fixed to the device bed and extends a certain distance over the device bed, It has a side stand, wherein said horizontal bridge is equipped with a grinding spindle carrier adjustablely mounted along a first axis, said device bed being configured to protrude one side from the portal.

The two stands are conveniently placed on both side regions of the device bed. In order to increase the strength of the stand, the stand can be further supported towards the projecting front of the device bed. In order to further increase the strength, a closed reinforcement rear wall can be installed between the two stands, and for this reason can also be firmly fixed to the device bed. At the same time the rear wall forms a sealed rear enclosure for the work area and at least a covering hood which surrounds the grinding spindle carrier and the workpiece carrier and which is connected to the device bed and / or portal and extends over the device bed. Encapsulates the entire device, in order for the covering hood to block the portal and the device bed to prevent leakage of lubricant.

In order to facilitate access to the workpiece and the wheel on all sides, it is advantageous to configure the device bed to have a substantially partially cylindrical shape at the protruding front. This device bed provides a very simple and aesthetically pleasing condition for the covering hood when it is bell shaped or partially cylindrical in shape.

The new universal grinding machine guarantees a large free space for the machining area, a short protruding bearing for the grinding spindle and a small moving mass. First of all, despite the large working area and high adaptability, the device is very compact and robust. Due to the low weight of moving parts and shorter adjustment paths and improved lever condition compared to column type grinders, the grinder is more than possible with conventional grinder designs with similar power requirements. Withstands high dynamic loads This reduces the probability of unproductive work accidents and greatly increases the efficiency of the grinding machine in all respects.

At the same time, the new design allows the grinding wheel receiving means on the grinding spindle and the grinding spindle length itself to be mechanically and geometrically set to the minimum dimensions, thereby moving the grinding wheel to the correct spatial position for each grinding operation. The adjustment path required is relatively short (in principle, twice the reduction of the wheel wheel receiving means and the grinding spindle). In practice a symmetrical device structure is obtained, for example the right and left helical milling cutters, drills and the like can be ground in the same order. Thus, the processing of complex devices such as, for example, radial milling cutters and stepped tools becomes very simple and economical since the external dimensions of the grinding machine do not need to be made larger.

Power and / or lubricant supply lines for the grinding spindle carrier and spindle drive can be accommodated in the portal to protect it from the influence of lubricant and coolant from the work area and not interfere with the actual work area.

Depending on the desired purpose of using the grinding machine, the grinding spindle carrier itself may be designed to have one or several spindles. In a preferred embodiment, the grinding spindle carrier has one or more drive motors coupled to at least one grinding spindle via a belt drive, the belt drive being disposed in a closed housing, the interior of the housing having a positive relative to the ambient environment. Positive air pressure can be maintained. In practice, this is achieved by the so-called sealing air acting on the inner housing which prevents the penetration of lubricating oil or cooling water and thus the damage of the grinding spindle drive. In order to achieve a reduced structural design and a uniform bearing load, it is convenient for the belt drive to be coupled to each computational spindle which is supported on two bearings in the bearing in the area between the two bearing points.

The grinding spindle carrier is conveniently supported on the bridge of the portal via the support, the support having an adjustment slide forming a second axis, the slide extending toward the projecting front of the device bed at right angles to the first and second axes. And a bearing means for the grinding spindle carrier forming a third axis, wherein the grinding spindle body is mounted to enable a pivoting movement about the third axis.

Depending on the number of grinding spindles accommodated in the grinding spindle carrier, the at least one grinding spindle may be arranged such that the spindle axis and the third axis intersect or extend at a distance from the third axis. Usually the grinding spindle axis itself extends perpendicular to the third axis.

The design and bearing of the workpiece carrier mainly depend to some extent on the type and type of workpiece to be machined. The work carrier is advantageously mounted to the bearing element adjustable along a fourth axis perpendicular to the first and second axes in the device bed. The adjustability of the workpiece carrier can be further increased by mounting on the bearing element by means of a rotary table forming a fifth vertical axis and by a composite slide forming sixth and seventh axes which are additionally installed at right angles to each other depending on the given environment. . Finally, it is advantageous for the workpiece carrier to have a workpiece clamping device which is rotatable about the eighth axis, ie the workpiece axis of rotation.

Embodiments of the present invention will be described with reference to the drawings.

1 is a schematic perspective view of a grinding machine according to the invention designed with up to six control NC axes.

2 shows the part of the grinding machine according to FIG. 1 with up to eight control NC axes at the highest stage in design to illustrate the alignment and correlation of the translational and rotary axes for adjusting the grinding spindle carrier and the workpiece carrier of the grinding machine. Perspective shown at different scales.

3 is a partial side view showing the grinding spindle carrier of the grinding machine according to FIG. 1 at different scales.

Explanation of symbols on the main parts of the drawings

1: machine bed 9: portal

10: stand 11: bridge

15: support 20: grinding spindle carrier

22: grinding spindle 25, 26: grinding wheel

27: drive motor 32: spindle axis

44: workpiece carrier 50: covering hood

The grinding machine has a box-shaped device bed 1 made, for example, as a cast or welded structure of gray cast iron, the grinding machine being substantially partially circular or partially elliptical in plan view. A correspondingly curved partially circular circumferential wall 2 extends from the flat rear side 3. The circumferential wall has a raised edge (4) above the covering wall (5) that is inclined substantially flat or slightly funneled, which extends towards the rear side (3) and to the surface on which the device is next mounted. Extends downwards at point 6; On the front or working side of the grinder, opposite the rear side 3, a circumferential wall 2 is made conical on the floor 7 to make free space for the operator's feet installed on the working side in front of the grinding machine. . The assembly leg 8 is arrange | positioned at this site | part. Both sides of the assembly legs are provided with rectangular conveying grooves for conveying by forklift trucks.

In fact, the U-shaped portal 9 is mounted to the device bed 1 with its flat rear side 3 aligned with the device bed. The portal 9 is configured as two vertical stands 10 and a bridge 11 which connects the stands and at the same time extends above a certain distance of the device bed 1. The bridge 11 is actually a beam or girder shaped design with a rectangular cross section. The two stands 10 are arranged in the manner shown in FIG. 1 in both side regions of the device bed 1 so that one side of the structure of the device bed 1 protrudes from the portal 9. In the side view, the stand is approximately triangular and is supported by the projecting front of the device bed, ie the flange 12 which is inclined towards the working side. The closed reinforcing flat rear wall 13 blocks the space enclosed by the two stands 10, the bridge 11 and the covering wall 5 of the device bed 1 from the rear and between the two stands 10. Are arranged in. The rear wall 13 is firmly connected not only to the device bed 1 but also to the bridge 11 and the stand 10, and at the same time forms a reinforcement for the portal 9.

The torsion-free rigid portal 9 can be made of a box-like structure, such as a welded or cast structure, depending on the circumstances given as one or more parts, and can be firmly connected to the device bed 1, for example by screws. Alternatively, the device bed 1 and the portal 9 may be a single casting.

On the front side facing the protruding device bed 1, the bridge 11 has a horizontal longitudinal guide 14 shown in FIG. 1, which along the first horizontal axis, ie the straight axis -y. The support 15 is mounted to allow longitudinal movement. The longitudinal guide 14 may be covered in the usual way by the bellows 160 (first and second degrees).

The vertical slide 16 is guided in the support 15 via a linear guide 17 capable of longitudinal movement along a second axis, i. The straight axis -z extends perpendicular to the horizontal straight axis -y and is therefore vertical.

A horizontal cylindrical bearing pin 18, pointing towards the projecting front of the device bed 1, is arranged in front of the vertical slide 16. The grinding spindle carrier 20 is mounted for pivotal movement at the point 19 of the bearing pin 18. The bearing pin 18 forms a horizontal third axis, that is, rotation axis + A, which extends above a certain distance of the device bed 1, around which the grinding spindle carrier 20 pivots up to 360 °. Can pivot over. Alternatively, a vertical pivot plane of the A axis on a vertical slide is also possible instead of a horizontal pivot plane (not shown).

The grinding spindle carrier 20 can be configured for one or several spindles. The spindle carrier comprises an elongated housing 21 (FIG. 3) in which at least one grinding spindle 22 is rotatably mounted at two spaced bearing points 23. The arithmetic spindle 22 has grinding wheel receiving means 24 on both sides, the receiving means protruding out of the housing 21 and having the grinding wheels 25, 26 (FIG. 2) suitable for the purposes of the present application. Is placed.

Instead of one grinding spindle 22 shown in the figures, several, in particular two grinding spindles axially parallel can be mounted as corresponding methods in the housing.

All grinding spindles 22 are driven by one or two electric motors which are attached to a common housing 21 for these spindles. In the illustrated embodiment, one electric motor 27 is provided. A flat or toothed belt pulley 29 is mounted to the shaft 28 (FIG. 3) and passes through the grinding spindle 22 via a flat or toothed belt 30 and a flat or toothed belt pulley 31. Drive. In order to achieve structural reduction and uniform bearing load, a flat or toothed belt pulley 31 lies between two bearing points 23.

Each grinding spindle 22 has its spindle axis 32 (FIG. 3) aligned at right angles to the axis of rotation + A, and the distance from the axis of rotation + A can be zero or> 0 depending on the number of grinding spindles. . In the present case, the grinding spindle axis 32 intersects the axis of rotation + A as shown in FIG.

The support 15, the vertical slide 16 and the grinding spindle carrier 20 are known and are therefore connected to a suitable actuating drive, not shown. These actuating drives have a corresponding adjustment movement along the linear axes -y and -z and also a pivoting movement about the rotation axis + A by means of a program control method on the support 15, the vertical slide 16 and the grinding spindle carrier 20. Each can be granted. Cooling and lubricant lines and compressed air lines, as well as the electrical connection lines of the actuating drive and drive motor 27, extend through the bridge 11 and the stand 10 of the yoke, and the grinding spindle carrier 20 The supply line 34 is passed through a bearing pin 18 in the form of a hollow pin.

A sealing air connection 35 is provided in the housing 21 (FIG. 3), so that the inside of the housing can be subjected to positive air pressure with respect to the surrounding environment via a corresponding compressed air line, so that the cooling emulsion and cooling oil are It is possible to prevent the infiltration into and thereby avoid the impairment of the function of the grinding spindle drive. In this way the entire drive assembly consisting of the drive motor 27, the belt drives 29 to 31 and the grinding spindle 22 with bearings 23 is effectively protected.

A measuring probe 37 or other suitable measuring instrument is attached to the front of the grinding spindle carrier 20 in the manner shown in FIG. 2 to determine the position of the workpiece and the position of the device axis described above with respect to a common reference point. Decide This data makes it possible to know to a considerable extent the spatial position of the device axis relative to the workpiece to be machined. Then, with the geometric data of the wheels 25 and 26, the microprocessor for controlling the actuation drive automatically positions and readjusts the wheels automatically before each grinding operation (zero point machining). Can be programmed to.

The longitudinal guide 38 is arranged on the covering wall 5 of the device bed 1, extending in the middle between the two stands 10 and extending perpendicularly to the flat rear side of the device bed 1. The longitudinal guide 38 extending approximately from the rear side 3 of the device bed 1 to the projecting front has a support element in the form of a slide 39 which is movable along the fourth axis, ie the linear axis + x '. It is installed. The linear axis + x 'is perpendicular to the linear axes -y and -z and extends parallel to the rotation axis + A.

The circular table 40 is mounted to the slide 39 so as to be rotatable about the fifth axis, that is, the vertical axis of rotation + C. Located in this table is the upper table 410 in FIG. 1 (small device), the composite slide 41 in FIG. 2 (large device), and the longitudinal slide 42 of the compound slide is located in a horizontal plane. It can be adjusted along the six axes, ie the linear axis + U '. The upper table 410 (FIG. 1) is fixedly connected to the circular table 40, ie the C axis, or the slide 39 in the absence of this table.

The transverse slide 43 of the composite slide 41 can be adjusted in the longitudinal slide 42 along the seventh axis, i.e., the front axis + V ', the seventh axis lying in the horizontal plane and the longitudinal slide 42 Extend at right angles to the linear axis + U 'defined by In general, the transverse slide 43 is designed to be rotatable with respect to the longitudinal slide 42.

Finally, the workpiece carrier 44 comprises a workpiece clamping device in the form of a chuck 45 and is placed on the upper table 410 or the transverse slide 43, respectively. Rotating workpiece 46, such as for example a drill or milling cutter, is clamped in chuck 45. The chuck 45 is mounted to the work carrier 44 so as to be rotatable about a horizontal eighth axis, that is, the rotation axis + B. The workpiece axis of rotation is designed such that a high rotational speed for circular grinding (≥ 300 rpm) and a step for grinding division operate at very high accuracy (rotation angle ≤ 0.001 °). Moreover, other workpiece carrier elements and truing devices, such as steadyrest, tail stock, etc., may also be disposed on the top table 410 or transverse slide 43, respectively.

Electrically actuated drives for the longitudinal and transverse slides and chucks 45 of the slide 39, the round table 40 and the composite slide 41 are known and are not shown in detail. The actuating drive is likewise powered from the inside of the device bed 1 via the hollow bearing pin of the circular table 40, which is not shown in detail in the figure. If the anti-vibration opening and the tail stock are arranged on the transverse slide 43, these parts can be designed to enable automatic adjustment as well, and the truing roller of the truing apparatus can be designed to enable program control truing. .

According to each purpose, the above-mentioned grinding machine can be manufactured to have 4, 5, 6, 7 or 8 program control axes. In a device with four program control axes (-y, -z, + B, x ') at the lowest stage in the design, the grinding spindle carrier 20 is used for grinding the helical leads to the workpiece 46. It can be designed to allow manual adjustment to the axis of rotation + A.

In the highest stage of design (figure 3), the associated translational movement axes in the coordinate system, i.e. linear axes X ', Y and Z, with minor axes + U' and + V 'in accordance with German Industrial Standard 66 217 And also spindles A, B and C are provided.

By means of the above-described arrangement of the spindle, the grinding spindle 22 is pivoted to any spatial grinding position so that in any case similar cutting positions and the most complex shapes can be ground in the workpiece 46, similar to a Cardan system. have.

Since the electric supply line, compressed air supply line, lubricating oil supply line and cooling water supply line all lie outside the immediate wet area, the work area is protected without any risk of collision with all supply lines, thus the possibility of breakage Greatly reduce

The grinding machine also has a bell-shaped or partially cylindrical covering hood 50 consisting of a transparent plastic material sealingly disposed on the bed along the contour of the device bed 1, or a sheet metal having a viewing window (FIG. 1). Can be covered completely by The covering hood 50 is a pre-finished structural part in which the door may be installed. The covering hood may also be configured to be sealedly fixed to the portal 9 at the rear side or alternatively to be sealedly arranged at the corner 4 of the device bed 1.

Claims (20)

A grinding spindle carrier having an apparatus bed, at least one driven grinding spindle with at least one grinding wheel at one end, and at least one at the same time disposed in the apparatus bed in the operating range of the grinding wheel (s) of the grinding spindle carrier Program control associated with the workpiece carrier mounted adjustablely along the axis of the workpiece and the grinding spindle carrier or the workpiece carrier or both the grinding spindle carrier and the workpiece carrier to impart the adjustment movement in the form of longitudinal and rotational movements, respectively, with respect to the individual axes. An adjustment device, wherein the grinding spindle carrier can be adjusted via bearings and guide means associated with respect to the device bed along at least two axes installed at right angles to each other, and in a given situation pivot movement about at least one axis Possibly configured, good It is according to the numerical control grinding machine for grinding a workpiece in particular a metal tool, Torsion-free portal (9) has a horizontal bridge (11) and two side stands (10) connected to and fixed to the device bed (1) and extending over a distance from the device bed (1), A grinding spindle carrier 20 is mounted on the horizontal bridge so as to be adjustable along the first axis (-y), and the device bed 1 is configured such that one side protrudes from the portal 9. Controlled grinding machine. 4. The numerically controlled grinding machine according to claim 1, wherein the two stands (10) are arranged in both side regions of the device bed (1). 3. The numerically controlled grinding machine according to claim 1, wherein the two stands (10) are supported towards the projecting front of the device bed (1). 3. The numerically controlled grinding machine according to claim 1, wherein a closed reinforcing rear wall (13) is arranged between the two stands (10). 4. The numerically controlled grinding machine according to claim 3, wherein the rear wall (13) is fixedly connected to the device bed (1). 4. A numerically controlled grinding machine as claimed in claim 1, characterized in that the device bed (1) consists of a contour which is substantially partially circular in front of its protruding face. The device bed (1) according to claim 1, which surrounds at least the grinding spindle carrier (20) and the work carrier (44) and is connected to the device bed (1) or the portal (9) or to both the device bed and the portal. A numerically controlled grinder, having a covering hood 50 extending upwards. 7. A numerically controlled grinding machine according to claim 6, characterized in that the covering hood (50) is sealed in the device bed (1) or the portal (9) or sealed in both the device bed and the portal. 8. The numerically controlled grinding machine according to claim 6 or 7, wherein the covering hood (50) is substantially bell shaped or partially cylindrical in design, and is made of a transparent plastic material or sheet metal having a viewing window. 2. The power supply or lubricant supply line or coolant supply line 34 for the grinding spindle carrier 20 and the spindle drive is accommodated in the portal 9. Numerically controlled grinding machine. 2. The grinding spindle carrier (20) according to claim 1, having at least one drive motor (27) coupled to at least one grinding spindle (22) via belt drives (30, 31, 32), The belt drive is characterized in that it is arranged in a closed housing (21) in which a positive air pressure can be maintained in relation to the surrounding environment. 11. A numerically controlled grinding machine according to claim 10, characterized in that the belt drive is coupled to a grinding spindle (22) supported as a bearing on two sides in the region between the two bearing points (23). The grinding spindle carrier (10) according to claim 1, wherein the grinding spindle carrier (10) is mounted to the bridge (11) via a support (15), said support being an adjustment slide (16) and a grinding spindle carrier forming a second axis (-z). Bearing means (18, 19) for (20), the bearing means extending perpendicular to the first axis (-y) and the second axis (-z) and at the same time extending the projecting front of the device bed (1) And a grinding spindle carrier mounted to the bearing means to enable pivoting about the third axis (+ A). 14. A numerically controlled grinder as claimed in claim 13, characterized in that the spindle axis (32) of the at least one grinding spindle (22) intersects with the third axis (+ A). The numerically controlled grinding machine according to claim 13 or 14, characterized in that the at least one grinding spindle (22) is arranged such that its spindle axis (32) is spaced apart by a distance from the third axis (+ A). . 14. The numerically controlled grinder as claimed in claim 13, wherein the bearing means is designed as a hollow shaft. 2. The work carrier 44 according to claim 1, wherein the workpiece carrier 44 is adjustable along a fourth axis (+ x ') perpendicular to the first axis (-y) and the second axis (-z) in the device bed (1). Numerically controlled grinding machine characterized in that it is mounted on the bearing element (39). 18. A numerically controlled grinding machine as claimed in claim 17, characterized in that the workpiece carrier (44) is mounted to the bearing element (39) by a rotary table (40) forming a fifth vertical axis (+ V '). 19. The bearing as claimed in claim 17 or 18, wherein the workpiece carrier (44) is formed by a composite slide (41) forming two sixth and seventh axes (+ U ', + V') installed at right angles to one another. Numerically controlled grinding machine, characterized in that mounted to the element (39). 19. A numerically controlled grinding machine as claimed in claim 17 or 18, characterized in that the workpiece carrier (44) has a workpiece clamping device (45) rotatable about an eighth axis (+ B) which is the workpiece axis of rotation.