CN106938441B - Device for finishing a workpiece - Google Patents

Abstract

The invention relates to a device (10) for finishing a workpiece (18), said device comprising: a tool mandrel (26) for a finishing tool (12); a tool mandrel (26) for delivering said tool mandrel (26) ); a force measuring device (56) acting between said tool mandrel (26) and said delivery device (32); and between said tool mandrel (26) and said A connecting device (44) operative between delivery devices (32) for connecting the tool mandrel (26) and the delivery device (32), wherein the connecting device (44) comprises Two parts ( 46 , 48 ) that are movable relative to each other, which parts are connected to each other by the force measuring device ( 56 ), so that the force measuring device ( 56 ) is the connecting function of the connecting device ( 44 ) made of.

Description

Device for finishing workpieces

technical field

The invention relates to a device for finishing workpieces having a tool mandrel for finishing a tool, a delivery device for delivering the tool mandrel, a force acting between the tool mandrel and the delivery device A measuring device and a connecting device acting between the tool mandrel and the delivery device and for connecting the tool mandrel and the delivery device.

Background technique

EP 1329289 A2 discloses such a device. In this device, the connecting means are formed by leaf springs and support the tool mandrel on the delivery device. A force measuring device in the form of a piezoelectric element is used to measure the processing force that occurs during the finishing of the workpiece.

A disadvantage of the known device is that the machining forces occurring during the finishing of the workpiece can cause vibrations that reduce the finishing accuracy of the workpiece.

SUMMARY OF THE INVENTION

In view of the above problems, it is an object of the present invention to improve a device of the above-mentioned type so that the measurement of the processing force can be performed without reducing the finishing accuracy of the workpiece.

The above object is achieved by a device according to the invention of the type described above, in which the connecting device comprises two parts movable relative to each other, which are connected to each other by a force measuring device such that the force measuring device is a connecting device component for conducting power.

According to the invention, the force-measuring device is a force-transmitting component of the connecting device. In the context of the present invention, a connecting device is to be understood as a device that produces a mechanical connection between the delivery device and the tool mandrel. The force measuring device is an integral part of the connecting device. The force-measuring device receives at least a portion of the force required for mechanical retention between the delivery device and the tool mandrel; thus, removal of the force-measuring device results in the breaking of the mechanical connection between the tool mandrel and the delivery device.

According to the invention, by integrating the force measuring device into the connecting device, an overall stable configuration can be obtained, which structure does not reduce the finishing accuracy of the workpiece. At the same time, it is possible to measure the handling forces that occur during the finishing of the workpiece, since the handling forces are transmitted from the tool mandrel through the connecting device to the delivery device.

A particularly simple construction of the connecting device is obtained when the first part of the connecting device is connected to the delivery device and the second part of the connecting device is connected to the tool mandrel.

In a particularly preferred stable configuration, the part is designed as a flat body. The flat body itself is mechanically stable and accordingly serves as a carrier for a tool mandrel or a delivery device.

In order to further increase the stability, the parts are preferably only movable relative to each other in a single degree of freedom.

A particularly simple construction is obtained when the single degree of freedom is the relative pivotability of the parts.

Preferably, the force-measuring device can be loaded with tensile and/or compressive forces and prevent relative movement of the components. In particular, the force measuring device can only be loaded with tensile and/or compressive forces. In a particularly preferred variant, the force-measuring device is only provided for receiving compressive forces. As an integral part of the connection device, the force measurement device transmits the static connection force required for the mechanical connection between the delivery device and the tool mandrel. The value of the static connection force depends on the weight of the components and the orientation of the device; the static connection force can be measured by a force measuring device, eg determined from a "zero point" from which the processing force occurring during operation of the device is measured. The processing force and the static connection force measured by the force measuring device extend along the same force transmission axis.

In a particularly preferred embodiment, the connecting device comprises a pivot bearing arranged spaced relative to the force measuring device and relative to the axis of the tool mandrel, by means of which the components can pivot relative to each other. This results in a simple and stable construction of the connecting device, which in addition enables a simple pivoting of the handling force which, starting from the workpiece, affects the tool arranged on the tool mandrel and then passes through the tool mandrel The shaft is guided into the connecting device and reaches the force measuring device.

If the pivot axis defined by the pivot bearing extends at an angle, in particular vertically, with respect to the delivery axis of the delivery device, especially when machining flat and spherical surfaces, the action of the finishing tool relative to the workpiece can be adjusted angle, and thus influence the geometric parameters of the so-called "cross-grinding".

Furthermore, preferably, the force measuring device is arranged in the force transmission path of the spacing adjustment device acting between the components. The spacing adjustment device enables adjustment of the spacing between the components in the sense of the spacing between the components measured along the force measuring device. The spacing adjustment device can adjust the absolute spacing between the parts or can adjust the angular spacing between the parts.

Additional features and advantages of the present invention are presented in the following description and drawings of preferred embodiments.

Description of drawings

Figure 1 shows a perspective view of an embodiment of an apparatus for finishing a workpiece;

FIG. 2 shows a side view of the device of FIG. 1 with the tool mandrel of the device in an initial position; and

Figure 3 shows a side view similar to Figure 2 with the tool mandrel in an operating position inclined relative to the initial position.

Detailed ways

In the figures, the device for finishing a workpiece is indicated in its entirety by the reference numeral 10 . The device 10 comprises a finishing tool 12, which is designed, for example, in the form of a cup-shaped grinding wheel. The cup-shaped grinding wheel has on its end face an annular action surface 14 with which the flat or spherical surface 16 of the workpiece 18 can be machined.

The workpiece 18 is received in a workpiece holder 20 (eg, a chuck). The drive workpiece 18 is driven by the workpiece drive 22 in a rotational manner about a drive axis 24 .

The tool 12 is held on a tool mandrel 26 and is driven by a drive device 28 in rotation about a mandrel axis 30 . The mandrel axis 30 and the drive axis 24 of the workpiece 18 extend substantially parallel to each other or are inclined relative to each other by several degrees (eg, up to 5°).

In order to be able to deliver the active surface 14 of the tool 12 in the direction of the workpiece 18 and to leave it again, a delivery device is provided, which is indicated as a whole by the reference numeral 32 . The delivery device 32 includes a carrier 34 connected to a drive device 36 that acts on a carriage 38 . The carriage 38 can be deflected along the delivery axis 40 by the drive means 36 . The delivery axis 40 extends parallel or at least substantially parallel (eg, inclined at a maximum of 5°) with respect to the mandrel axis 30 . The delivery device 32 also serves to generate the pressing force with which the active surface 14 of the finishing tool 12 is pressed against the surface 16 of the workpiece 18 .

For connecting the carriage 38 of the delivery device 32 on the one hand and the housing 42 of the tool mandrel 26 on the other hand, the device 10 comprises connecting means indicated as a whole by the reference numeral 44 .

The connecting device 44 comprises two plate-shaped parts 46 and 48 which are movable relative to each other. The first part 46 is particularly bolted to the carriage 38 of the delivery device 32 . The second part 48 is particularly bolted to the housing 42 of the tool mandrel 26 .

To connect the parts 46 and 48 , a pivot bearing 50 is provided, which defines a pivot axis 52 . The pivot axis 52 has a spacing 54 relative to the mandrel axis 30 of the tool mandrel 26 . The pivot bearing 50 is only shown schematically in the figures. In a conventional manner, for example, a pivot bearing includes a pivot pin and a bushing surrounding the pivot pin.

A pivot pin between the parts 46 and 48 connects the parts 46 and 48 so that they can only move relative to each other in a single degree of freedom. Therefore, the parts 46 and 48 can only pivot relative to each other about the pivot axis 52 . Advantageously, the pivot axis 52 is located on the ends of the components 46 and 48 adjacent to the tool 12 .

In order to prevent pivoting between the parts 46 and 48 , the connecting device 44 includes a connecting region 54 which acts as a force-conducting component of the connecting device 44 . Only tensile and compressive forces are transmitted in the connecting region 54 . In the connecting region 54 , the connecting forces acting between the components 46 and 48 are transmitted via the force-measuring device 56 . The force measuring device 56 can be formed, for example, by a dynamometer.

In the connection region 54 , the force measuring device 56 transmits tensile and compressive forces along a force transmission axis 58 .

In particular, the force measuring device 56 transmits compressive forces only along the force transmission axis 58 . In this case, it is advantageous for the force-measuring device 56 to comprise two parts movable relative to each other, which are biased relative to each other by a spring and are spaced apart from each other by a sensor unit. In this way, components 46 and 48 can be positioned relative to each other without play.

The force transmission axis 58 is arranged at an angle relative to the pivot axis 52 , in particular vertically or at least substantially vertically, and has a distance 60 relative to the pivot axis 52 .

A distance adjusting device 62 is arranged in the connecting region 54 , which is arranged mechanically in series with the force measuring device. The spacing adjustment device 62 includes, for example, an adjustment shaft 64 connected at one end to one of the components 46 and 48 and connected to the force measurement device 56 at the other end. In order to fix the distance adjusting device 62, an adjusting nut 66 can be provided.

The spacing adjustment device 62 allows adjustment of the spacing between the components 46 and 48 measured along the force transmission axis 58 . By spacing the force transfer axis 58 relative to the pivot axis 52, the variation in the spacing present along the force transfer axis between the components 46 and 48 causes the components 46 and 48 to pivot relative to each other about the pivot axis 52, see FIG. 2 and 3. In this way, the angle of inclination of the mandrel axis 30 can be adjusted. For example, the axes 24 and 30 can extend parallel to each other (see FIG. 2 ); or the axes 24 and 30 can extend obliquely relative to each other (see FIG. 3 ).

During finishing of the workpiece 18 , the workpiece 18 is rotated about the axis 24 . At the same time, the tool 12 is rotated about the mandrel axis 30 . The active surface 14 of the tool 12 meshes with the workpiece surface 16 of the workpiece 18 . Since the compressive force of the tool 12 is applied to the workpiece 18 for finishing the workpiece 18 , the tool 12 is subjected to a corresponding pressing force, which is indicated by reference numeral 62 in FIG. 2 . The squeezing force 62 affects the torque acting on the tool mandrel 26 about the pivot axis 52 via the "lever arm" 54 (corresponding to the illustration in FIG. axis of rotation 52 extends).

An opposing torque is applied to the tool mandrel 26 by means of a force measuring device 56 with a "lever arm" 60 spaced relative to the pivot axis 52 , thereby making it stationary relative to the pivot axis 52 . The opposing torque is equal to the product of the process force measured by the force measuring device 56 along the force transfer axis 58 (the reaction force corresponding to the compressive force exerted on the force measuring device by the second member 48 ) and the length of the “lever arm” 60 . .

Accordingly, the squeezing force 62 is equal to the product of the process force measured by the force measuring device 56 and the lever arm factor (spacing 60 divided by the spacing 54).

Claims (7)

1. An apparatus (10) for finishing a workpiece (18), the apparatus comprising:

a tool mandrel (26) for finishing a tool (12);

a delivery device (32) for delivering the tool mandrel (26);

a force measuring device (56) acting between the tool mandrel (26) and the delivery device (32); and

a connecting device (44) acting between the tool mandrel (26) and the delivery device (32) for connecting the tool mandrel (26) and the delivery device (32),

characterized in that the connecting device (44) comprises two parts (46, 48) which can be moved relative to one another and which are connected to one another by the force-measuring device (56), so that the force-measuring device (56) is a component of the connecting device (44) for force transmission,

the connecting device (44) comprises a pivot bearing (50) which is arranged at a distance from the force measuring device (56) and from the spindle axis (30) of the tool spindle, wherein a force transmission axis (58) of the force measuring device (56) is arranged at an angle to a pivot axis (52) of the pivot bearing (50), wherein a change in the distance between the parts (46, 48) along the force transmission axis (58) causes the parts (46, 48) to be pivotable relative to one another via the pivot bearing.

2. The device (10) of claim 1, wherein a first component (46) is connected to the delivery device (32) and a second component (48) is connected to the tool mandrel (26).

3. Device (10) according to claim 1 or 2, characterized in that the parts (46, 48) are formed as flat bodies.

4. Device (10) according to claim 1 or 2, characterized in that the force measuring device (56) can be loaded with tensile and/or compressive forces and resists relative movement of the parts (46, 48).

5. The device (10) of claim 1, wherein the pivot axis (52) defined by the pivot bearing (50) extends at an angle relative to a delivery axis (40) of the delivery device (32).

6. The device (10) of claim 5, wherein the pivot axis (52) defined by the pivot bearing (50) extends perpendicularly relative to the delivery axis (40) of the delivery device (32).

7. Device (10) according to claim 1 or 2, characterized in that the force measuring device (56) is arranged in the force transmission path of a spacing adjustment device (62) acting between the components (46, 48).

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