Facing machine

Abstract

To provide a facing machine capable of reducing the deviation of weight on a surface board and enhancing efficiency in processing work.SOLUTION: A facing machine 100 includes a rotary shaft, a drive part 2, a surface plate 3, a slider 4, a tool attachment part 5, a counter weight 6, a measurement mechanism 120 and a counter weight replacement mechanism 130. The slider 4 can move in a direction approaching the rotation center of the surface plate 3 and separating therefrom; the tool attachment part 5 provided in the slider 4 can attach a tool; the counter weight 6 attachably / detachably attached to the rotation center of the surface plate 3 on the side opposite to the tool reduces the deviation of weight when rotating the surface plate 3; the measurement mechanism 120 for measuring the deviation of weight on the surface plate 3 capable of attaching the tool and the counter weight 6 outputs an actuating signal corresponding to the deviation; and the counter weight replacement mechanism 130 replaces the counter weight 6 on the basis of the actuating signal.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a facing machine. [Background technology]

[0002] A facing machine, for example, comprises a rotatable face platen and a slider with a tool mounting portion. In a facing machine, a tool suitable for processing is mounted on the tool mounting portion. A facing machine processes a workpiece by rotating the tool through the rotation of the face platen. A slider with a tool mounted on the tool mounting portion is called a "slider with tool."

[0003] The center of gravity of the tool-equipped slider is offset from the center of rotation of the facing platen. Therefore, a facing platen to which a tool-equipped slider is attached may have a weight imbalance relative to the center of rotation. In a facing machine, to reduce the weight imbalance, a counterweight is provided on the opposite side of the center of gravity of the tool-equipped slider relative to the center of rotation of the facing platen. The counterweight is selected so as to balance the weight on the facing platen (see, for example, Patent Document 1 and Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 11-294164 [Patent Document 2] Japanese Patent Application Publication No. 11-333669 Summary of the Invention [Problem to be solved by the invention]

[0005] In the facing machine, the counterweight to be used must be selected taking into consideration the machining conditions (weight, position, type of tool, etc.) If the machining conditions are changed, a new counterweight is required to match the changes.

[0006] However, in the above-mentioned facing machine, the work of selecting a counterweight and attaching it to the facing plate can be time-consuming.

[0007] An object of one aspect of the present invention is to provide a facing machine that can automate the task of replacing a counterweight. [Means for solving the problem]

[0008] A facing machine according to aspect 1 of the present invention comprises a rotating shaft, a drive unit for rotating the rotating shaft, a face plate rotatably supported on the rotating shaft, a slider that can move in directions toward and away from the center of rotation of the face plate, a tool mounting portion provided on the slider to which a tool is attached, a counterweight that is detachably attached to the opposite side of the tool relative to the center of rotation of the face plate and reduces weight imbalance when the face plate rotates, a measurement mechanism that measures the weight imbalance of the face plate to which the tool and counterweight are attached and outputs an operation signal according to the imbalance, and a counterweight replacement mechanism that replaces the counterweight based on the operation signal.

[0009] It is preferable that the counterweight exchange mechanism comprises a weight magazine unit that holds a plurality of counterweights of different weights, a first transport unit that transports the counterweight attached to the base plate, a second transport unit that transports the counterweight held in the weight magazine unit, and a transport control unit that exchanges the counterweight attached to the base plate with the counterweight held in the weight magazine unit by operating the first transport unit and the second transport unit based on the operation signal.

[0010] It is preferable that the measurement mechanism includes a load sensor that detects a load value applied to the rotation axis when the faceplate is rotated, and a calculation unit that sends the operation signal to the counterweight exchange mechanism when the difference between the minimum and maximum load values ​​becomes equal to or greater than a threshold value.

[0011] It is preferable that the measurement mechanism includes a torque sensor that detects the rotational torque of the rotating shaft in the drive unit, and a calculation unit that sends the operation signal to the counterweight replacement mechanism when the rotational torque becomes equal to or greater than a threshold value.

[0012] It is preferable that the counterweight exchange mechanism selects the counterweight associated with the tool from the weight magazine and exchanges this counterweight for the counterweight attached to the face plate. [Effects of the Invention]

[0013] According to one aspect of the present invention, it is possible to provide a facing machine that can automate the task of replacing a counterweight. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a configuration diagram of a facing machine according to a first embodiment. [Figure 2] FIG. 1 is a perspective view of a part of a facing machine according to a first embodiment. [Figure 3] FIG. 2 is a cross-sectional view showing the internal structure of a part of the facing machine of the first embodiment. [Figure 4] 5 is a flowchart showing processing in a measurement mechanism of the facing machine of the first embodiment. [Figure 5] FIG. 2 is a block diagram showing the configuration of a transport control unit of the facing machine of the first embodiment. [Figure 6] 5 is a flowchart showing processing in a counterweight replacement mechanism of the facing machine of the first embodiment. [Figure 7] FIG. 3 is an explanatory diagram showing the operation of the facing machine of the first embodiment. [Figure 8] FIG. 3 is an explanatory diagram showing the operation of the facing machine of the first embodiment. [Figure 9]FIG. 3 is an explanatory diagram showing the operation of the facing machine of the first embodiment. [Figure 10] FIG. 10 is a configuration diagram of a facing machine according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of a facing machine according to the present invention will be described with reference to the drawings.

[0016] [Facing machine] (first embodiment) Fig. 1 is a configuration diagram of a facing machine 100 according to a first embodiment. Fig. 2 is a perspective view of a portion of the facing machine 100. Fig. 3 is a cross-sectional view showing the internal structure of a portion of the facing machine 100.

[0017] As shown in FIG. 1, the facing machine 100 includes a processing unit 110, a measuring mechanism 120, and a counterweight exchanging mechanism . As shown in FIGS. 2 and 3, the processing unit 110 includes a rotary shaft 1, a drive unit 2, a face plate 3, a slider 4, a tool attachment unit 5, a counterweight 6, and a main plate 7.

[0018] In the following description, an XYZ Cartesian coordinate system may be used. The X and Y directions are parallel to the front surface 3a of the panel 3. The X and Y directions are perpendicular to each other. The Z direction is perpendicular to the X and Y directions. The X direction is the left-right direction. The Y direction is the up-down direction. The up-down direction is the height direction. The Z direction is the front-back direction.

[0019] Based on Fig. 3, the positional relationship of each component of the facing machine 100 will be provisionally defined. The left side in Fig. 3 is the front side. The right side in Fig. 3 is the rear side. The upper side in Fig. 3 is the upper side. The lower side in Fig. 3 is the lower side.

[0020] The rotating shaft 1 extends in the front-to-rear direction (Z direction). The rotating shaft 1 has a central axis C1. The rotating shaft 1 is inserted into an insertion hole 7a in the main plate 7. The insertion hole 7a is a through hole that runs along the thickness direction of the main plate 7. The driving unit 2 rotates the rotating shaft 1 around the central axis C1. The driving unit 2 is, for example, a motor. The driving unit 2 is installed, for example, on the rear side of the main plate 7.

[0021] The face plate 3 is, for example, disk-shaped. The face plate 3 is provided on the front side of the main plate 7. The face plate 3 is provided at the front end of the rotating shaft 1. The face plate 3 is rotatably supported on the rotating shaft 1. The face plate 3 is rotated around the central axis C1 by the drive unit 2. The central axis C3 (center of rotation) of the face plate 3 coincides with the central axis C1 of the rotating shaft 1.

[0022] A first guide 11 and a mounting recess 12 are formed on the front surface 3a of the face panel 3. In the embodiment shown in FIG. 3, the first guide 11 is groove-shaped along the vertical direction (Y direction). The first guide 11 is formed along the radial direction of the face panel 3. The first guide 11 is formed from the center to the upper edge of the front surface 3a of the face panel 3. In the embodiment shown in FIG. 3, the mounting recess 12 is formed in the lower part of the front surface 3a of the face panel 3. The mounting recess 12 may also be groove-shaped along the vertical direction (Y direction).

[0023] The slider 4 is formed, for example, in the shape of a rectangular parallelepiped. The rear portion of the slider 4 is detachably engaged with the first guide 11. The slider 4 is movable up and down along the first guide 11. The slider 4 is movable up and down by a slider movement mechanism (not shown), and can be positioned at any height. The slider 4 rotates around the central axis C3 together with the face plate 3. In the form shown in FIG. 3, the slider 4 is located higher than the center of the face plate 3.

[0024] The tool mounting portion 5 is provided on the front surface of the slider 4. The tool mounting portion 5 protrudes forward from the front surface of the slider 4. A tool 10 can be detachably attached to the tool mounting portion 5. The tool 10 is selected according to the machining shape of the workpiece, etc. The tool 10 protrudes forward from the tool mounting portion 5. A slider 4 with a tool 10 attached to the tool mounting portion 5 is a "tool-equipped slider 8."

[0025] 3, the tool attachment portion 5 is located higher than the center of the face plate 3. Therefore, the center of gravity of the tool-equipped slider 8 is located higher than the center of the face plate 3.

[0026] A counterweight 6 is provided on the front surface 3a of the face panel 3. The counterweight 6 is detachably attached to the attachment recess 12. The counterweight 6 rotates together with the face panel 3 around the central axis C3.

[0027] In the embodiment shown in Fig. 3, the center of gravity of the counterweight 6 is located lower than the center of the face plate 3. Therefore, the center of gravity of the counterweight 6 is located on the opposite side of the center of gravity of the tool slider 8 with respect to the center of the face plate 3. The counterweight 6, which is located on the opposite side of the center of the face plate 3, can reduce the imbalance in weight when the face plate 3 rotates.

[0028] The counterweight 6 can be selected according to the machining conditions so as to reduce the weight imbalance of the face plate 3. The machining conditions include, for example, the weight, position, type, machining method, and machining shape of the tool 10. The installation position of the counterweight 6 on the face plate 3 can be determined according to the machining conditions so as to reduce the weight imbalance of the face plate 3.

[0029] 1, the measurement mechanism 120 includes a load sensor 21 and a calculation unit 22. The measurement mechanism 120 measures the weight deviation of the face plate 3 to which the tool-equipped slider 8 and the counterweight 6 are attached (see FIGS. 2 and 3).

[0030] The load sensor 21 detects, for example, a radial load value applied to the rotation shaft 1 (see FIG. 2) when rotating the faceplate 3. The load sensor 21 is preferably a strain gauge type, a piezoelectric type, or the like.

[0031] If the weight of the face plate 3 to which the tool slider 8 and counterweight 6 are attached is unevenly distributed, the load value applied to the rotation axis 1 when the face plate 3 is rotated tends to increase or decrease. Therefore, the minimum value of the load value applied to the rotation axis 1 when the face plate 3 is rotated tends to decrease, and the maximum value tends to increase.

[0032] If the weight imbalance of the face plate 3 to which the tool slider 8 and counterweight 6 are attached is small, the load value applied to the rotation axis 1 when the face plate 3 is rotated is unlikely to increase or decrease. Therefore, the minimum value of the load value applied to the rotation axis 1 when the face plate 3 is rotated tends to increase, and the maximum value tends to decrease.

[0033] If the weight imbalance of the face plate 3 to which the tooled slider 8 and counterweight 6 are attached is large, the difference between the minimum and maximum load values ​​will be large. If the weight imbalance of the face plate 3 is small, the difference between the minimum and maximum load values ​​will be small. Therefore, the difference between the minimum and maximum load values ​​is correlated with the weight imbalance of the face plate 3. Therefore, the weight imbalance of the face plate 3 can be measured from the difference between the minimum and maximum load values.

[0034] FIG. 4 is a flowchart showing the processing in the measurement mechanism 120. As shown in Fig. 4, the calculation unit 22 acquires the minimum and maximum load values ​​detected by the load sensor 21 (step S01). The calculation unit 22 calculates the difference between the minimum and maximum load values ​​(step S02). The calculation unit 22 determines whether the difference between the minimum and maximum load values ​​is equal to or greater than a threshold value (step S03). When the difference between the minimum and maximum load values ​​is equal to or greater than the threshold value, the calculation unit 22 sends an operation signal corresponding to this difference to the transfer control unit 34 (step S04). When the difference between the minimum and maximum load values ​​is less than the threshold value, the process returns to step S01.

[0035] As shown in FIG. 1, the counterweight replacement mechanism 130 replaces the counterweight 6 based on the weight deviation measured by the measurement mechanism 120. The counterweight exchange mechanism 130 includes a weight magazine unit 31, a first transfer unit 32, a second transfer unit 33, a transfer control unit 34, and a drive unit 35.

[0036] The weight magazine unit 31 holds a plurality of counterweights 6 having different weights. For example, the plurality of counterweights 6 include counterweights 6A to 6E. The counterweights 6A to 6E have increasing weights in this order, for example.

[0037] The first transport section 32 can transport the counterweight 6 attached to the face plate 3. The first conveying unit 32 includes a first arm unit 41 and a first gripping unit 42. The first arm unit 41 extends linearly from a support unit 43. The first gripping unit 42 is attached to the tip of the first arm unit 41. The first gripping unit 42 can detachably grip the counterweight 6. The first conveying unit 32 is rotatable around a central axis C4, with the support unit 43 as a fulcrum. The central axis C4 is parallel to the Z direction.

[0038] The second transport section 33 can transport the counterweight 6 held in the weight magazine section 31. The second conveying unit 33 includes a second arm unit 44 and a second gripping unit 45. The second arm unit 44 extends linearly from the support unit 43. The second gripping unit 45 is attached to the tip of the second arm unit 44. The second gripping unit 45 can detachably grip the counterweight 6. The second conveying unit 33 is rotatable around the support unit 43.

[0039] The first arm unit 41 and the second arm unit 44 extend in opposite directions from the support unit 43. The first transfer unit 32 and the second transfer unit 33 are positioned in rotational symmetry with the support unit 43 as the axis. The first transfer unit 32 and the second transfer unit 33 operate integrally. The drive unit 35 rotates the first transport unit 32 and the second transport unit 33. The drive unit 35 is, for example, a motor. The drive unit 35 can also move the first transport unit 32 and the second transport unit 33 in the front-to-rear direction (Z direction).

[0040] FIG. 5 is a block diagram showing the configuration of the transfer control unit 34 of the counterweight exchanging mechanism 130. As shown in FIG. As shown in FIG. 5, the transfer control unit 34 includes a processing unit 51 and a database 52.

[0041] The database 52 stores weight data of the tool 10 used in machining and weight data of the counterweight 6. The database 52 may also store weight data of the tool-equipped slider 8. The database 52 may also store the weight of the slider 4.

[0042] The processing unit 51 executes a program for calculating, for example, the weight of the counterweight 6 that can reduce the weight imbalance between the tool-equipped slider 8 and the counterweight 6. The processing unit 51 performs overall control of the counterweight exchange mechanism 130. The processing unit 51 operates the first transfer unit 32 and the second transfer unit 33 based on an operation signal from the calculation unit 22.

[0043] Fig. 6 is a flowchart showing the processing in the counterweight exchanging mechanism 130. Figs. 7 to 9 are explanatory diagrams showing the operation of the facing machine 100. A method for exchanging the counterweight 6 will be described with reference to Figs. 6 to 9. As shown in FIG. 6, the processing unit 51 receives an operation signal from the calculation unit 22 and calculates the weight of the counterweight 6 that can reduce the weight imbalance between the tool slider 8 and the counterweight 6 (step S11).

[0044] As shown in FIG. 7, the processing unit 51 operates the first transport unit 32 and the second transport unit 33. Specifically, the first transport unit 32 grips the counterweight 6 attached to the face plate 3 with the first gripping unit 42 and removes it from the face plate 3. The processing unit 51 selects a counterweight 6 from the weight magazine unit 31 according to the weight imbalance described above, based on an operation signal from the calculation unit 22. Specifically, the processing unit 51 selects a counterweight 6 from the weight magazine unit 31 that can reduce the weight imbalance between the tool-equipped slider 8 and the counterweight 6. The second transport unit 33 grips and removes the selected counterweight 6 (step S12 shown in FIG. 6). In this embodiment, the processing unit 51 selects the counterweight 6D.

[0045] The processing unit 51 may select a counterweight 6 that is associated with the tool 10 in advance from the weight magazine unit 31.

[0046] Whether or not the weight imbalance between the tool slider 8 and the counterweight 6 can be reduced can be determined, for example, by the weight, the distance from the center of rotation of the face plate 3, and the angular velocity. For example, let the weight of the tool slider 8 be "M1." Let the distance between the center of gravity of the tool slider 8 and the center of rotation of the face plate 3 be "L1." Let the angular velocity of the face plate 3 be ω1. Let the weight of the counterweight 6 be "M2." Let the distance between the center of gravity of the counterweight 6 and the center of rotation of the face plate 3 be "L2." Let the angular velocity of the face plate 3 be ω2.

[0047] The processing unit 51 can select the counterweight 6 by taking into consideration the difference between "M1·L1·ω1" and "M2·L2·ω2." For example, the processing unit 51 can select the counterweight 6 that reduces the difference between M1·L1·ω1 and M2·L2·ω2.

[0048] As shown in Fig. 8, the drive unit 35 rotates the first transport unit 32 and the second transport unit 33. As shown in Fig. 9, the processing unit 51 (see Fig. 5) attaches the counterweight 6 (counterweight 6D in this embodiment) removed from the weight magazine unit 31 to the face panel 3. The processing unit 51 (see Fig. 5) causes the counterweight 6 removed from the face panel 3 to be held in the weight magazine unit 31. This replaces the counterweight 6 attached to the face panel 3 with the counterweight 6 (6D) held in the weight magazine unit 31 (step S13 shown in Fig. 6).

[0049] The counterweight 6 (counterweight 6D in this embodiment) attached to the face plate 3 can reduce the weight imbalance between the tool slider 8 and the counterweight 6. This can suppress the occurrence of vibrations and the like when the face plate 3 rotates. This can prevent the vibrations and the like from affecting the machining accuracy.

[0050] [Effects of the facing machine of the embodiment] The facing machine 100 of this embodiment is equipped with a measurement mechanism 120 that measures the weight imbalance of the face plate 3 to which the tool-equipped slider 8 and the counterweight 6 are attached, and a counterweight replacement mechanism 130 that replaces the counterweight 6. Therefore, by replacing the counterweight 6 with the counterweight replacement mechanism 130, it is possible to reduce the weight imbalance of the face plate 3. In this way, the facing machine 100 can automate the task of replacing the counterweight 6.

[0051] The facing machine 100 can reduce the time and effort required to select the counterweight 6 and attach it to the face plate 3. This can improve the efficiency of the processing work.

[0052] The measurement mechanism 120 includes a load sensor 21 and a calculation unit 22. When the difference between the minimum and maximum load values ​​exceeds a threshold value, the calculation unit 22 sends an operation signal to the counterweight exchange mechanism 130. The counterweight exchange mechanism 130 exchanges the counterweight 6 based on the operation signal. Therefore, it is possible to select a counterweight 6 that can reduce the weight imbalance of the face panel 3.

[0053] The counterweight replacement mechanism 130 uses the first transfer unit 32 and the second transfer unit 33, so that the replacement of the counterweight 6 can be performed efficiently.

[0054] [Facing machine] (Second embodiment) FIG. 10 is a configuration diagram of a facing machine 200 according to the second embodiment. 10, in a facing machine 200, a measurement mechanism 220 includes a torque sensor 221 instead of the load sensor 21. The torque sensor 221 measures the rotational torque when the rotating shaft 1 is rotated in the drive unit 2.

[0055] If the weight imbalance of the face plate 3 to which the tool slider 8 and counterweight 6 are attached is large, the rotational torque in the drive unit 2 will be large. If the weight imbalance of the face plate 3 is small, the rotational torque in the drive unit 2 will be small. Therefore, the rotational torque in the drive unit 2 is correlated with the weight imbalance of the face plate 3. Therefore, the weight imbalance of the face plate 3 can be measured by the rotational torque in the drive unit 2.

[0056] The calculation unit 22 acquires the rotational torque measured by the torque sensor 221. The calculation unit 22 determines whether the rotational torque is equal to or greater than a threshold value. When the rotational torque is equal to or greater than the threshold value, the calculation unit 22 sends an operation signal to the transfer control unit 34.

[0057] The counterweight replacement mechanism 130 replaces the counterweight 6 based on the weight deviation measured by the measurement mechanism 220.

[0058] The facing machine 200 of this embodiment is equipped with a measurement mechanism 220 that measures the weight imbalance of the face plate 3, and a counterweight replacement mechanism 130 that replaces the counterweight 6. Therefore, the counterweight replacement mechanism 130 can reduce the weight imbalance of the face plate 3. The facing machine 200 can automate the task of replacing the counterweight 6.

[0059] The facing machine 200 can reduce the time and effort required to select the counterweight 6 and attach it to the face plate 3. This can improve the efficiency of the processing work.

[0060] The measurement mechanism 120 includes a torque sensor 221 and a calculation unit 22. When the rotational torque in the drive unit 2 exceeds a threshold value, the calculation unit 22 sends an operation signal to the counterweight exchange mechanism 130. The counterweight exchange mechanism 130 exchanges the counterweight 6 based on the operation signal. Therefore, it is possible to select a counterweight 6 that can reduce the weight imbalance of the face panel 3.

[0061] The counterweight replacement mechanism 130 uses the first transfer unit 32 and the second transfer unit 33, so that the replacement of the counterweight 6 can be performed efficiently.

[0062] The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. 1, when the difference between the minimum and maximum load values ​​exceeds a threshold, an operation signal is sent to the counterweight exchange mechanism 130, but the method of controlling the operation of the counterweight exchange mechanism 130 is not limited to this. For example, when the orientation of the face plate 3 is determined so that the tool slider 8 and the counterweight 6 are aligned horizontally, the load value applied to the face plate 3 may be measured, and the counterweight exchange mechanism 130 may be operated based on this load value.

[0063] The weight magazine unit 31 may hold not only the counterweight 6 but also one or more replacement tools 10. The counterweight replacement mechanism 130 may be capable of replacing not only the counterweight 6 but also the tool 10. For example, the first transport unit 32 can transport the tool 10 attached to the tool mounting unit 5. The second transport unit 33 can transport the tool 10 held in the weight magazine unit 31. The first transport unit 32 and the second transport unit 33 can replace the tool 10 attached to the tool mounting unit 5 with the tool 10 held in the weight magazine unit 31.

[0064] In addition, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments and variations may be combined as appropriate, without departing from the spirit of the present invention. [Explanation of symbols]

[0065] 1...rotating shaft, 2...driving unit, 3...face plate, 4...slider, 5...tool mounting unit, 6, 6A to 6E...counterweight, 10...tool, 21...load sensor, 22...calculating unit, 31...weight magazine unit, 32...first conveying unit, 33...second conveying unit, 34...conveyance control unit, 120, 220...measuring mechanism, 130...counterweight exchange mechanism, 221...torque sensor

Claims

1. A rotation axis; a drive unit that rotates the rotation shaft; a face plate rotatably supported on the rotation shaft; a slider that is movable in a direction toward and away from the rotation center of the face plate; a tool attachment portion provided on the slider to which a tool is attached; a counterweight that is detachably attached to the opposite side of the tool with respect to the rotation center of the face platen and that reduces weight imbalance when the face platen is rotated; a measuring mechanism that measures the imbalance in weight between the tool and the faceplate to which the counterweight is attached and outputs an operation signal corresponding to the imbalance; a counterweight exchange mechanism that exchanges the counterweight based on the operation signal; Equipped with Facing machine.

2. The counterweight exchange mechanism includes: a weight magazine unit that holds a plurality of counterweights having different weights; a first transport unit that transports the counterweight attached to the face plate; a second transport unit that transports the counterweight held in the weight magazine unit; a transport control unit that operates the first transport unit and the second transport unit based on the operation signal to exchange the counterweight attached to the face plate with the counterweight held in the weight magazine unit; Equipped with 2. The facing machine according to claim 1.

3. The measurement mechanism includes a load sensor that detects a load value applied to the rotation shaft when the faceplate is rotated; a calculation unit that sends the operation signal to the counterweight exchange mechanism when a difference between the minimum and maximum load values ​​is equal to or greater than a threshold value; Equipped with 2. The facing machine according to claim 1.

4. the measuring mechanism includes a torque sensor that detects the rotation torque of the rotation shaft in the drive unit; a calculation unit that sends the operation signal to the counterweight replacement mechanism when the rotational torque becomes equal to or greater than a threshold value; Equipped with 2. The facing machine according to claim 1.

5. the counterweight exchange mechanism selects the counterweight associated with the tool from the weight magazine and exchanges the selected counterweight for the counterweight attached to the face plate; 3. A facing machine according to claim 2.

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