A machine tool for robot-assisted machining of a workpiece with two rotary cutters
By using a combination of flywheel clutch and linear actuator on the machine tool, along with magnet and sensor detection, the problem of process force control in traditional robot-assisted machining is solved, enabling automatic tool changing and efficient machining of multiple process steps.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- FERROBOTICS COMPLIANT ROBOT TECH
- Filing Date
- 2021-11-30
- Publication Date
- 2026-07-14
AI Technical Summary
Traditional industrial robots struggle to precisely control process forces in robot-assisted surface machining, especially during tool switching, which increases machining time and impacts machining efficiency.
By employing a combination of flywheel clutch and linear actuator, the flywheel clutch switches the tool in different rotation directions, and the tool position is detected by magnets and sensors, thus realizing automatic tool changing and process force control.
This enables the execution of multiple process steps without changing the tool, improving machining efficiency and accuracy while reducing tool change time.
Smart Images
Figure CN116600938B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a machine tool for robot-assisted surface processing. Background Technology
[0002] In robot-assisted surface finishing, machine tools (such as grinders, drills, milling machines, polishing machines, etc.) are guided by robotic arms (such as industrial robots). During this process, the machine tool can be coupled to the robotic arm's so-called TCP (tool center point) in various ways; typically, the robotic arm can adjust the position and orientation of the TCP almost arbitrarily to move the machine tool along a trajectory, for example, parallel to the workpiece surface. Industrial robots are typically position-controlled, allowing the TCP to move precisely along the desired trajectory.
[0003] In many applications, achieving good results in robot-assisted grinding, polishing, or other surface finishing processes requires control of process forces (e.g., grinding forces), which traditional industrial robots often struggle to achieve with sufficient precision. The large, heavy arms of industrial robots have too much inertia, making it difficult for closed-loop controllers to react quickly enough to fluctuations in process forces. To address this, a smaller (lighter) linear actuator, less powerful than the industrial robot itself, can be placed between the robot's control arm (TCP) and the machine tool, coupling the TCP to the machine tool. During surface finishing, the linear actuator controls only the process forces (i.e., the contact force between the tool and the workpiece), while the robot moves the machine tool and the linear actuator along the desired trajectory under position control. Through force control, the linear actuator can compensate for inaccuracies in the position and shape of the workpiece and, within certain limits, the inaccuracies in the robot's trajectory. However, some robots are capable of regulating process forces through force / torque control, even without the aforementioned linear actuator. In some setups, the relatively heavy drive mechanism of the machine tool (e.g., an electric motor or compressed air motor) is mechanically decoupled from the actual cutting tool (e.g., a grinding wheel). This means that the relatively heavy drive of the grinding machine is firmly connected to the robotic arm, and only the relatively light machine tool portion, which assembles (rotates) the cutting tool, is moved by a linear actuator (force control). For this purpose, the rotating cutting tool can be connected to the drive via a telescopic shaft, as described in publication US 2019 / 0232502 A1, the contents of which are incorporated herein by reference in their entirety.
[0004] In many surface finishing processes, tool changes are required between different process steps. Tool changes can be performed semi-automatically or fully automatically with the assistance of robots. For this purpose, tool changing stations are known, for example, that allow automatic replacement of worn tools, or that also allow, for example, the replacement of grinding wheels with polishing wheels. Although tool changes can be automated or robot-assisted, frequent tool changes can still increase machining time.
[0005] The inventors set themselves the task of developing an improved machine tool that could operate with fewer tool changes, and in particular, allowed several process steps (such as grinding and subsequent polishing) to be performed without changing tools. Summary of the Invention
[0006] The following describes a machine tool capable of robot-assisted machining of workpieces. According to one embodiment, the machine tool includes a support, a first shaft mounted on the support and having a receiving portion for a first tool, and a second shaft mounted on the support and having a receiving portion for a second tool. The machine tool further includes a drive shaft mechanically coupled to the first shaft via a first flywheel clutch (directly or indirectly) and to the second shaft via a second flywheel clutch (directly or indirectly). In a particular embodiment, the first and second flywheel clutches are designed to drive the first shaft when the drive shaft rotates in a first direction and to drive the second shaft when the drive shaft rotates in a second direction.
[0007] According to another embodiment, the machine tool has a transmission, a first axis having an assembly position for a first tool, and a second axis having an assembly position for a second tool. The transmission is directly or indirectly coupled to the first axis via a first flywheel clutch and directly or indirectly coupled to the second axis via a second flywheel clutch, such that the transmission drives the first or second axis depending on the direction of rotation. Furthermore, a corresponding method for robot-assisted machining of a workpiece using a machine tool is described. Attached Figure Description
[0008] Various implementations will now be explained in more detail with reference to the examples shown in the figures. The representations are not necessarily to scale, and the invention is not limited to these aspects. Instead, the fundamental principles of the proposed embodiments are emphasized.
[0009] Figure 1 This is a perspective view of an embodiment of a machine tool for robot-assisted machining of a surface, wherein the machine tool can accommodate two rotating cutting tools on two opposite sides.
[0010] Figure 2 A simplified sectional view (longitudinal section) of a machine tool according to another embodiment is shown.
[0011] Figure 3 It shows the Figure 2 A modification and extension of the example, in which the tool is driven by an eccentric shaft.
[0012] Figure 4 It shows the Figure 2 Modification of the example.
[0013] Figure 5 Another embodiment is shown in which the motor directly drives the shaft of the assembly tool. Detailed Implementation
[0014] For example, robots and manipulators are well-known for automatically machining workpiece surfaces, using them to move machine tools along a trajectory. Because process forces play a crucial role in robot-assisted machining of workpieces, various force control concepts have been developed. Process forces are the forces between the rotating tool and the workpiece during machining, such as the forces between the grinding wheel and the workpiece surface during grinding.
[0015] Among other things, the embodiments described herein are applicable to force control via linear actuators, as described in publication US2019 / 0232502A1. In some embodiments, a rotary tool is mounted at the front of the machine tool, while a drive (e.g., an electric motor) for rotating the tool is mounted at the rear of the machine tool. The rear of the machine tool is also connected to a robot / manipulator. The aforementioned linear actuator is located between the front and rear. To transmit rotary motion, a telescopic shaft is provided between the motor at the rear of the machine tool and the tool at the front, which can compensate for changes in actuator deflection. In other embodiments, the motor is located at the front of the machine tool. In this case, a telescopic shaft is not required.
[0016] It is important to note that the concepts described here can also be applied to machine tools that do not have integrated linear actuators. There are no integrated linear actuators, nor is a telescopic axis required. In these cases, force control is performed directly by the robot / manipulator itself (a robot with force / torque control), or the linear actuator is not integrated into the machine tool but is arranged between the robot and the machine tool. The embodiments described here essentially involve the coupling of a motor-driven axis (telescopic axis, normal axis, or motor axis) to two different rotating cutting tools.
[0017] Figure 1 An example of a machine tool with an integrated linear actuator and telescopic axis is shown, with only the front of the machine tool shown and the linear actuator only schematically drawn. The front of the machine tool essentially includes a support 32, which can be, for example, a mounting plate, a mounting frame, a housing portion, etc. The support 32 can be composed of multiple parts rigidly connected to each other (and, for example, forming an assembly frame together). For example, in Figure 1 In the example shown, plate 32' and cylindrical pin 32'' are parts of bracket 32. The rear of the machine tool may also have a mounting plate (not shown), which, for example, is connected to the TCP (tool center point) of the robot / manipulator. The linear actuator 20, shown only schematically, couples the rear of the machine tool, which also houses the motor 10, to the bracket 32 at the front of the machine tool. For example, actuator 20 may include a double-acting pneumatic cylinder and a linear guide.
[0018] like Figure 1The second drive shaft 33 (telescopic shaft) shown is mounted on the shaft end of the bracket 32 (assembly plate), for example, by means of ball bearings. The other end of the telescopic shaft is directly or indirectly coupled to the motor shaft of the motor 10. The telescopic shaft drives sub-shafts 34 and 34' via belts 41 and 51. In the example shown, sub-shafts 34 and 34' are arranged substantially parallel to the telescopic shaft (if their rotation axes are parallel, then the shafts are parallel). Sub-shafts 34 and 34' are mounted on the bracket 32 (e.g., on plate 32' and the assembly plate of the bracket 32). The telescopic shaft, as well as sub-shafts 34 and 34', are the drive shafts for driving the first tool 12 and the second tool 13.
[0019] Sub-shafts 34 and 34' are coupled to the first tool 12 and the second tool 13 to drive them. For example, the first tool 12 and the second tool 13 can be two different grinding wheels, a grinding wheel and a polishing wheel, a milling cutter and a grinding wheel, or another pair of tools. Since both sub-shafts 34 and 34' are driven by the second drive shaft 33 via a belt, sub-shafts 34 and 34' always move synchronously, but may have different speeds at different transmission ratios of the belt drive. Therefore, in some embodiments, a single shaft driven by a single belt drive can be provided instead of sub-shafts 34 and 34'. The coupling of sub-shaft 34 to the first tool 12 and the second tool 13... Figure 2 The diagram is shown schematically and will be further explained below.
[0020] Figure 2 A bearing 331 (e.g., a ball bearing or a needle bearing) is shown, with a telescopic shaft (a drive shaft connected to the motor 10) rotatably mounted on a bracket 32. Figure 2 Bearings 342 and 341 are also shown, with the sub-shaft 34 mounted on bracket 32 and plate 32', respectively. As described above, in this case, only a single belt 41 is needed to couple the second drive shaft 33 and the sub-shaft 34. The first shaft 46 and the second shaft 56 are arranged coaxially with the sub-shaft 34, wherein the first ends of the first shaft 46 and the sub-shaft 34 are coupled via a first flywheel clutch 45, and the second ends of the second shaft 56 and the sub-shaft 34 are coupled via a second flywheel clutch 55. The first cutting tool 12 and the second cutting tool 13 can be mounted on the outer ends of the first shaft 46 and the second shaft 56 (i.e., opposite to the first flywheel clutch 45 and the second flywheel clutch 55) (see also). Figure 1 ).
[0021] For example, the first freewheeling / overrunning clutch 45 and the second freewheeling clutch 55 can be designed as a drawn cup roller clutch. A drawn cup roller clutch is a one-way clutch, typically consisting of thin-walled, non-cut outer cups with clamping ramps, a plastic retainer, a pressure spring, and a needle roller. They transmit torque in only one direction and save space radially. Flywheels are available in bearingless and bearing-bearing versions. Draw-cup roller clutches typically have relatively low overrunning frictional torque. Draw-cup roller clutches and other freewheeling clutches are well-known and commercially available from various manufacturers (e.g., Schaeffler). Therefore, they will not be described further here.
[0022] The assembly of the first flywheel clutch 45 and the second flywheel clutch 55 is such that when the second drive shaft 33 and the sub-shaft 34 rotate counterclockwise, the first shaft 46 (first tool shaft) is driven through the first flywheel clutch 45, while the second flywheel clutch 55 is in an idling state and does not transmit any significant torque to the second shaft 56 (second tool shaft). Conversely, when the second drive shaft 33 and the sub-shaft 34 rotate clockwise, the second shaft 56 is driven through the second flywheel clutch 55, while the first flywheel clutch 45 is in an idling state and does not transmit any significant torque to the first shaft 46. At idle, the first flywheel clutch 45 and the second flywheel clutch 55 can only transmit torque up to the level of frictional torque.
[0023] In the case of robot-assisted workpiece machining, the workpiece can be machined first using a first grinding wheel (e.g., first tool 12) mounted on the first axis 46. Motor 10 (see...) Figure 1 Therefore, the second drive shaft 33 and the sub-shaft 34 are also rotating counterclockwise. To change the tool and, for example, machine the workpiece with a second grinding wheel (e.g., second tool 13) mounted on the second shaft 56, the robot simply flips the machine tool (rotating 180° around a rotation axis located in a plane orthogonal to the rotation axis of the second drive shaft 33) and reverses the rotation direction of the motor 10. Then, during machining of the workpiece with the second grinding wheel, the motor 10 is rotating clockwise. In other embodiments, all rotation directions can be opposite. As previously mentioned, the sub-shaft 34 can be split into two. In this case, two belts (e.g., ...) are required. Figure 1 (As shown in the example). In this case, the transmission ratios of the two belt drives may be different.
[0024] Figure 3 It shows the Figure 2Modifications / extensions to the example. This modification / extension also applies to axis 46 and axis 56. For simplicity, Figure 3 Only the machine tool portion with the second axis 56 is shown. In this embodiment, the second axis 56 is coupled to an eccentric axis 57 at its outer end, as is common in eccentric grinding machines or orbital grinding machines. Grinding machines with eccentric axes are well known and will not be discussed further here.
[0025] In addition, Figure 3 In the example, a tab, lug, or other element 61 protrudes asymmetrically from the second axis 56 and is attached to the second axis 56. Element 61 may be specifically positioned on a ring (first element 62) or sleeve that runs about the second axis 56. The ring can be clamped onto the second axis 56 at any angular position to allow adjustment of the angular position of element 61. Near element 61 (the lug), a magnet (second element 58), particularly a permanent magnet, may be placed. If element 61 is made of a ferromagnetic material (e.g., ferritic tool steel), the magnet will attract element 61 and therefore the second axis 56 to a defined angular position that can also be considered a reference position (see [reference]). Figure 3 (See Figure (a), where element 61 and the magnet are directly opposite each other). The arrangement of the magnet and element 61 can also be designed such that the idling friction torque of the second flywheel clutch 55 is insufficient to rotate the shaft out of this defined position. This ensures that when the motor 10 rotates counterclockwise, the second shaft 56 remains stationary and is not carried away by the idling friction torque of the second flywheel clutch 55. For example, when the motor 10 rotates counterclockwise, unintentional rotation of the second shaft 56 could cause material adhering to the second cutter 13 (e.g., dust particles, polishing agent, etc.) to be ejected. The magnet prevents this. The same applies to the first shaft 46 and the first cutter 12 when the motor rotates clockwise. The arrangement of the magnet and element 61 is also suitable for machines without an eccentric shaft.
[0026] In addition to or alternatively to permanent magnets, the machine tool may have a sensor 60 configured to detect a specific angular position of the second axis 56. The sensor 60 may be, for example, an optical sensor (e.g., a reflective photoelectric sensor) or another proximity sensor that substantially detects the second axis 56 being in a reference position. If the second axis 56 is in a reference position, the eccentric axis 57 is also in a reference position, which may facilitate the automatic changing of the second tool 13.
[0027] In addition, the first axis 46 ( Figure 3 (Not shown) may have a ring with asymmetrically protruding elements, which is attracted by a magnet to pull the shaft to a reference position and prevent the first shaft 46 from being carried away by the idling friction torque when the first flywheel clutch 45 is idling. A sensor for detecting the reference position may also be provided here. To avoid unnecessary repetition, please refer to the above. Figure 3The description is as follows. In other embodiments, instead of magnets, friction linings or one or more locking rollers are provided to ensure that the respective first shaft 46 and second shaft 56 are not carried away by the idling friction torque of the respective flywheel clutch.
[0028] Figure 4 It shows the Figure 2 Modification of the example. In this embodiment, as... Figure 1 Two belts, belt 41 and belt 51, are used; however, with Figure 1 Compared to the example in the previous discussion, the first flywheel clutch 45 and the second flywheel clutch 55 are located on the other side of the belt drive. However, the function of this mechanism is essentially the same as in the example discussed earlier. The first flywheel clutch 45 and the second flywheel clutch 55 are mounted on the second drive shaft 33 (e.g., a telescopic shaft, a regular drive shaft, or a motor shaft) such that when the second drive shaft 33 rotates counterclockwise, the first flywheel clutch 45 can transmit torque, thus driving the first shaft 46 (first tool shaft) via the belt 41 when the second flywheel clutch 55 is idling. If the second drive shaft 33 rotates clockwise, the opposite occurs; in this case, only the second flywheel clutch 55 can transmit torque, and the second shaft 56 is driven via the belt 41 when the first flywheel clutch 45 is idling. A pulley can be externally mounted on the first flywheel clutch 45 and the second flywheel clutch 55. Depending on the direction of rotation of the second drive shaft 33, one or the other pulley is "taken away" by the second drive shaft 33. It should be understood that in Figure 4 In the example, the second drive shaft 33, the first shaft 46, and the second shaft 56 are not only mounted at one end (see...) Figure 4 (bearings 331, 341, and 342), and can be installed in another location, even Figure 4 It is not explicitly shown in the document.
[0029] Figure 5 Another embodiment is shown, which can be regarded as a modification of... Figure 2 Modifications to the embodiment. In this example, the second drive shaft 33 and belt drive have been replaced by a motor 10 that directly drives the first shaft 46 and the second shaft 56 (without a gearbox). In this case, the sub-shaft 34 is a motor shaft extending from both sides of the motor housing. The ends of the motor shaft are coupled to the first shaft 46 and the second shaft 56 via a first flywheel clutch 45 and a second flywheel clutch 55, on which the cutting tool is mounted. In this example, the first flywheel clutch 45 and the second flywheel clutch 55 operate in the same manner as... Figure 2 The examples in [the document] are the same, and refer to the relevant descriptions above.
[0030] like Figure 5As shown, a telescopic axis is not required in this example. Motor 10 is mounted / assembled at the front of the machine tool. Nevertheless, actuator 20 can be located between the front of the machine tool (support 32) and the rear of the machine tool (not explicitly shown). The rear of the machine tool can be mounted on the robot's TCP.
[0031] The following is a summary of some aspects of the embodiments described herein, which is not a final enumeration but merely an exemplary summary. One embodiment relates to a machine tool capable of performing robot-assisted machining of a workpiece. The machine tool includes a support, a first axis 46 mounted on the support (see... Figure 2 ) and the second shaft 56 mounted on the bracket (see Figure 2 The first shaft 46 has a receiving portion for the first tool 12 (e.g., a grinding wheel), and the second shaft 56 (see...) Figure 2 The machine tool has a housing for a second tool 13 (e.g., a polishing wheel). The machine tool also includes (at least) a drive shaft (see...). Figure 2 , telescopic shaft and sub-shaft 34, or Figure 1 Sub-shafts 34 and 34' are mechanically coupled to the first shaft 46 via a first flywheel clutch 45 (directly or indirectly) and via a second flywheel clutch 55 (see...). Figure 2 Mechanically coupled to the second axis 56.
[0032] The drive shaft can be driven by a first belt drive and a second belt drive (e.g., see...). Figure 4 Belts 41 and 51 are coupled to the first shaft 46 and the second shaft 56. The flywheel clutch can be located on the driving side of the belt drive (see [link]). Figure 4 ) or the driven side (see Figure 2 ).
[0033] The first flywheel clutch 45 and the second flywheel clutch 55 are coupled to the drive shaft in opposite directions. That is, one of the flywheel clutches is always in an idling state. Therefore, the two flywheel clutches can be arranged to drive the first shaft 46 when the drive shaft rotates in a first direction, and to drive the second shaft 56 when the drive shaft rotates in a second direction. In one embodiment, the machine tool has a motor that is directly or indirectly coupled to and capable of driving the first drive shaft (see...). Figure 1 (Motor 10). In Figure 1 and Figure 2 In this context, the telescopic shaft can be considered a drive shaft. For example, it can be mechanically coaxially connected to the motor shaft. The motor 10 is also indirectly coupled to the sub-shaft 34 (or sub-shaft 34 and sub-shaft 34') via a belt (or any other gearbox), so the sub-shaft 34 can also be considered part of the transmission and therefore regarded as a drive shaft.
[0034] In one embodiment, the motor is directly mechanically connected to the drive shaft (see [link]). Figure 1The second drive shaft 33 is coaxial with the motor shaft, and this drive shaft is connected to at least one other drive shaft via a gearbox, particularly a belt drive (see...). Figure 2 Sub-axis 34 or Figure 1 (sub-shaft 34 and shaft 34'). This other drive shaft can have two sub-shafts (see sub-shaft 34'). Figure 1 Sub-shafts 34 and 34' are both driven by motors. The motors power the first tool 12 and the second tool 13. In different embodiments, the drivetrain can be separated at different locations. In another embodiment, sub-shaft 34 can be a motor shaft (e.g., an electric motor or compressed air motor, see below). Figure 5 ).
[0035] In one embodiment, actuator 20 is connected to the support of the machine tool. In this case, one of the drive shafts can be configured as a telescopic shaft (see...). Figure 1 Actuator 20 is specifically designed for regulating process force. If the motor is mounted / assembled at the front of the machine tool, a telescopic shaft is not required, and the front of the machine tool also houses / assembles the tool shaft (see, for example, see...). Figure 5 ).
[0036] According to one embodiment, the machine tool has a second axis 56 (see...) Figure 3 A first element 62 (e.g., a ferromagnetic marker) protrudes asymmetrically, and a second element 58 (e.g., a magnet) remains stationary relative to the support. This configuration is adapted to hold the first element 62 in a reference position when the second shaft 56 is not actively driven (i.e., when the associated flywheel clutch is idling), thereby also holding the second shaft 56 in a reference position. Alternatively, the first element 62 (connected to the shaft and rotating together) may also be a magnet, and the second element 58 (stationary relative to the support) may also be ferromagnetic. In some embodiments, the second element 58 has a friction pad or a locking roller.
[0037] Another embodiment relates to a method for robot-assisted machining of a workpiece using a machine tool, wherein a motor can drive either a first tool 12 or a second tool 13 via two flywheel clutches, depending on the direction of rotation. The method includes machining the workpiece with the first tool 12 mounted on a first axis 46 of the machine tool, rotating the machine tool and changing the direction of rotation of the machine tool's drive shaft, and machining the workpiece with the second tool 13 mounted on a second axis 56 of the machine tool.
Claims
1. A machine tool comprising the following components: Support (32); The first shaft (46), which is mounted on the bracket (32), has a receiving portion for the first tool (12); A second shaft (56), which is mounted on the bracket (32), has a receiving portion for a second tool (13); a first element (62) is also provided on the second shaft (56), which protrudes asymmetrically from the second shaft (56); The first drive shaft is directly or indirectly mechanically coupled to the first shaft (46) via the first flywheel clutch (45), and directly or indirectly mechanically coupled to the second shaft (56) via the second flywheel clutch (55). in, The first drive shaft is configured to drive the rotation of one of the first shaft (46) and the second shaft (56), while the other shaft is in an idling state; the first shaft (46) and the second shaft (56) are respectively arranged on opposite sides of the bracket (32) so as to realize tool changing by flipping the machine tool and changing the rotation direction of the first drive shaft; The machine tool further includes a second element (58) that is immovable relative to the support (32) and is adapted to hold the first element (62) and thus the second axis (56) in a reference position without being actively driven.
2. The machine tool according to claim 1, characterized in that, The first flywheel clutch (45) and the second flywheel clutch (55) are designed to drive the first shaft (46) when the first drive shaft rotates in a first direction and to drive the second shaft (56) when the first drive shaft rotates in a second direction. The first axis (46) and the second axis (56) are coaxially arranged so that the first tool (12) connected to the first axis (46) and the second tool (13) connected to the second axis (56) are arranged on opposite sides of the machine tool.
3. The machine tool according to claim 1, further comprising the following components: The motor (10) is directly or indirectly coupled to the first drive shaft and can drive the first drive shaft.
4. The machine tool according to claim 3, characterized in that, The first drive shaft is a motor shaft, which is connected to the first shaft (46) via the first flywheel clutch (45) and to the second shaft (56) via the second flywheel clutch (55).
5. The machine tool according to claim 1, characterized in that, The first drive shaft is coupled to the first shaft (46) and the second shaft (56) via a first belt drive and a second belt drive, and The flywheel clutch is located on the driving or driven side of the belt drive.
6. The machine tool according to claim 1, further comprising the following components: The motor (10) is connected to the second drive shaft (33), and At least one belt is coupled to the second drive shaft (33) and the first drive shaft.
7. The machine tool according to claim 6, characterized in that, The second drive shaft (33) is a telescopic shaft.
8. The machine tool according to any one of claims 1 to 7, characterized in that, The first drive shaft has two sub-shafts, each of which is driven by a belt.
9. The machine tool according to any one of claims 1 to 7, further comprising the following components: An actuator (20) is coupled to the support (32) and is designed to apply force to the support (32).
10. The machine tool according to claim 1, characterized in that, The first element (62) is ferromagnetic, and the second element (58) is a magnet, and vice versa.
11. The machine tool according to claim 1, characterized in that, The second element has a friction pad or a locking roller.
12. A machine tool having the following components: support; Transmission device; A first shaft having an assembly position for a first tool and a second shaft having an assembly position for a second tool; in, The transmission is directly or indirectly coupled to the first shaft via a first flywheel clutch and directly or indirectly coupled to the second shaft via a second flywheel clutch, such that the transmission drives the first shaft or the second shaft depending on the direction of rotation, thereby causing one of the first shaft and the second shaft to rotate while the other shaft is in an idling state; the first shaft and the second shaft are respectively arranged on opposite sides of the bracket so as to achieve tool changing by flipping the machine tool and changing the rotation direction of the transmission; The machine tool also includes: The first element protrudes asymmetrically from the second axis; The second element, which is immovable relative to the support, is adapted to hold the first element and thus the second shaft in a reference position without being actively driven.
13. A robot-assisted processing method, characterized in that, This method uses a machine tool mounted on a robot, as described in any one of claims 1 to 11, to process a workpiece, the method comprising the following steps: The workpiece is machined using a first tool (12) mounted on the first shaft (46); With the assistance of the robot, the machine tool is flipped and the rotation direction of the transmission or the first transmission shaft is changed respectively; and The workpiece is machined using a second tool (13) mounted on the second shaft (56).