Patent Application
20230256531
The present invention relates to a machine tool, a workpiece support device of a machine tool, a method of operating a machine tool, and a non-transitory computer readable storage medium program.
A technique of performing additive machining is known in which a material is added to a workpiece using, for example, arc discharge.
As a related technique, Japanese Patent No. 6100449 discloses a multi-tasking machine (hybrid machine). The multi-tasking machine described in Japanese Patent No. 6100449 includes an additive machining unit that performs additive machining by irradiating a workpiece with energy in a machining region; a cutting unit that performs cutting on the workpiece in the machining region; a cover unit that covers the machining region; and a light shielding filter that is disposed on at least one surface of the cover unit and changes the degree of light shielding based on light received from the machining region.
According to one aspect of the present invention, a machine tool includes a table which is configured to support a workpiece; a first machining head which is configured to support a wire such that a tip end of the wire is exposed from the first machining head and via which a molten material produced from the tip end of the wire is provided to the workpiece supported by the table; a second machining head configured to support a tool which is configured to cut the workpiece supported by the table; a power supply configured to supply a current to the wire; a conduction block disposed on the table to detect a position of the tip end of the wire; a drive device configured to relatively move the first machining head with respect to the table to bring the tip end of the wire into contact with the conduction block; and a first electric circuit configured to be changed from an open state to a closed state by bringing the tip end of the wire into contact with the conduction block.
According to another aspect of the present invention, a workpiece support device of a machine tool includes a pallet of a table of the machine tool to support a workpiece; and a conduction block provided on the pallet and configured to detect a position of a tip end of a wire which is supported by a first machining head of the machine tool such that the tip end of the wire is exposed from the first machining head. A molten material produced from the tip end is configured to be provided to the workpiece via the first machining head. The conduction block includes a first surface to determine a protruding length of the wire protruding from the first machining head; and an inclined surface that is disposed to be inclined with respect to the first surface to determine a displacement amount of the tip end of the wire displaced from an imaginary center axis of the wire.
According to the other aspect of the present invention, a method of operating a machine tool includes supporting a workpiece on a table of the machine tool; supporting a wire by a first machining head of the machine tool such that a tip end of the wire is exposed from the first machining head; providing a molten material produced from the tip end of the wire to the workpiece supported on the table; supporting a tool by a second machining head of the machine tool to cut the workpiece on the table via the tool; supplying a current to the wire; providing a conduction block on the table; relatively moving the first machining head with respect to the table to bring the tip end of the wire into contact with the conduction block; determining a timing at which the tip end of the wire is brought into contact with the conduction block such that the first electric circuit is switched from the open state to the closed state; and calculating a position displacement amount between an actual position of the tip end of the wire and an imaginary position of the tip end of the wire based on an actual position of the first machining head at the timing and a position of the conduction block at the timing.
According to further aspect of the present invention, a non-transitory computer readable storage medium retrievably stores a computer-executable program therein. The computer-executable program causes a computer to perform a method of operating a machine tool. The method includes relatively moving, with respect to a conduction block disposed on a table of the machine tool, a first machining head which supports a wire such that a tip end of the wire is exposed from the first machining head of the machine tool, so that the tip end is brought into contact with the conduction block; determining a timing at which the tip end of the wire is brought into contact with the conduction block such that a first electric circuit is switched from an open state to a closed state; calculating a position displacement amount between an actual position of the tip end of the wire and an imaginary position of the tip end of the wire based on an actual position of the first machining head at the timing and a position of the conduction block at the timing; correcting a position of the tip end of the wire or correcting an estimated relative position of the first machining head with respect to the tip end of the wire based on the position displacement amount; providing a molten material produced from the tip end of the wire to a workpiece supported by the table after the position of the tip end has been corrected or after the estimated relative position of the first machining head has been corrected; and cutting the workpiece supported by the table via a tool supported by the second machining head of the machine tool.
A more complete appreciation of the present disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
By referring to the drawings, description will be made with regard to a machine tool 1, a workpiece support device B of the machine tool 1, a method of operating the machine tool 1, and a program according to some embodiments. In the following description of the embodiments, parts, portions, members, and/or elements having the same function will be denoted with the same reference numerals, and description of parts, portions, members, and/or elements denoted with the same reference numerals will not be repeated.
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A machine tool 1A according to the first embodiment will be described by referring to
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The table 2 supports a workpiece D, which is an object to be machined. The table 2 may be a device capable of moving the workpiece D when the workpiece D is machined by the machine tool 1A. Alternatively, the table 2 may be a device incapable of moving the workpiece D when the workpiece D is machined by the machine tool 1A.
The first machining head 3 is a machining head that performs additive machining. The first machining head 3 supports the wire W in a state in which the tip end P of the wire W is exposed from the first machining head 3. In the example illustrated in
The first machining head 3 adds a molten material generated from the tip end P of the wire W to the workpiece D, which is supported by the table 2. For example, as illustrated in
In the example illustrated in
The power supply 13 supplies current to the wire W. At the time of additive machining, the wire W is melted by the current supplied to the wire W. More specifically, the tip end P of the wire W is melted by arc discharge generated between the tip end P of the wire W and the workpiece D. At the position identifying time, at which the position of the tip end P of the wire W is identified, the current supplied to the wire W is used to detect whether the tip end P of the wire W and the conduction block 5 are in contact with each other.
The conduction block 5 is disposed on the table 2. The conduction block 5 identifies the position of the tip end P of the wire W. More specifically, as illustrated in
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The first electric circuit C1 described above may include the power supply 13, in addition to the wire W and the conduction block 5. In other words, current may be supplied from the power supply 13 to the first electric circuit C1. The first electric circuit C1 may also include, in addition to the wire W and the conduction block 5, a cable 14, which electrically connects the table 2 and the power supply 13 to each other. In this case, the current supplied from the power supply 13 flows through the first electric circuit C1 including the wire W, the conduction block 5, and the cable 14.
In the examples illustrated in
Thus, the first embodiment provides, in the machine tool 1A, which performs additive machining and cutting, a technique of identifying the position of the tip end P of the wire W supported by the first machining head 3, which performs additive machining.
In the machine tool 1A according to the first embodiment, the conduction block 5, which identifies the position of the tip end P of the wire W, is disposed on the table 2, which supports the workpiece D. In this case, when the tip end P of the wire W is brought into contact with the conduction block 5, it is not necessary to move the first machining head 3 to a position far away from the normal machining region. This ensures that the step of identifying the position of the tip end P of the wire W is executed quickly. Also, it is not necessary to increase the movable range of the first machining head 3 in order to execute the step of identifying the position of the tip end P of the wire W.
Also, in a case where the conduction block 5 is disposed on the table 2, which supports the workpiece D, it is not necessary to provide a dedicated table for supporting the conduction block 5, separately from the table 2. Also, in a case where it is not necessary to provide a dedicated table for supporting the conduction block 5, the entire size of the machine tool 1A is made compact.
In the first embodiment, after the position of the tip end P of the wire W has been identified, the position of the tip end P of the wire W may be corrected. A method of correcting the position of the tip end P of the wire W will be described later. By correcting the position of the tip end P of the wire W, the accuracy of the position or shape of the added object added to the workpiece D (in other words, a molten material generated from the tip end P of the wire W) is improved. In the first embodiment, the table 2 that supports the workpiece D when additive machining is performed on the workpiece D is the same as the table 2 that supports the workpiece D when cutting is performed on the workpiece D. In this case, in addition to improving the accuracy of the position or shape of the added object added to the workpiece D, the surface of the added object added to the workpiece D can be cut into a desired shape with high accuracy in the cutting performed after the additive machining. In other words, excessive cutting or insufficient cutting is prevented from occurring in the cutting step performed after the additive machining step. Optional Additional Configurations
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Whether the tip end P of the wire W is in contact with the first surface 51 of the conduction block 5 can be determined by the control device 7 (see
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The inclined surface 52 is a surface for identifying the displacement amount of the tip end P of the wire W from the imaginary center axis AX of the wire W. For example, the first inclined surface 52a is a surface for identifying a first displacement amount indicating the degree to which the tip end P of the wire W is displaced from the imaginary center axis AX in the first direction DR1.
The control device 7 is capable of calculating the above-described first displacement amount based on: the actual position F of the first machining head 3 in a state in which the tip end P of the wire W is in contact with the first inclined surface 52a; and the position of the conduction block 5 (for example, the position of the first inclined surface 52a or the position of a second surface PL2). Details will be described later. It is to be noted that whether the tip end P of the wire W is in contact with the first inclined surface 52a of the conduction block 5 can be determined by the control device 7 based on the state of the first electric circuit C1 (more specifically, based on whether current is flowing through the first electric circuit C1).
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In a case where the inclined surface 52 of the conduction block 5 has the first inclined surface 52a and the second inclined surface 52b, it is possible to identify both the degree to which the tip end P of the wire W is displaced from the imaginary center axis AX in the first direction DR1 and the degree to which the tip end P of the wire W is displaced from the imaginary center axis AX in the second direction DR2.
The control device 7 is capable of calculating the above-described second displacement amount based on: the actual position F of the first machining head 3 in a state in which the tip end P of the wire W is in contact with the second inclined surface 52b; and the position of the conduction block 5 (for example, the position of the second inclined surface 52b or the position of a third surface PL3). Details will be described later. It is to be noted that whether the tip end P of the wire W is in contact with the second inclined surface 52b of the conduction block 5 can be determined by the control device 7 based on the state of the first electric circuit C1 (more specifically, based on whether current is flowing through the first electric circuit C1).
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Under the circumstances, the surface for identifying the displacement amount of the tip end P of the wire W from the imaginary center axis AX is preferably the inclined surface 52. It is to be noted, however, that in the first embodiment, the surface for identifying the displacement amount of the tip end P of the wire W from the imaginary center axis AX will not be limited to the inclined surface 52. In other words, the aspect illustrated in
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Next, another modification of the shape of the conduction block 5 will be described by referring to
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The material of the conduction block 5 may be the same as the material of the member of the table 2 that contacts the workpiece D (for example, the pallet 212, to which the workpiece D is attached), or may be different from the material of the member of the table 2 that contacts the workpiece D. The material of the conduction block 5 is preferably a material that is higher in wear resistance to arc discharge than the material of the member of the table 2 that contacts the workpiece D (for example, the pallet 212, to which the workpiece D is attached). In this case, wear of the conduction block 5 is eliminated or minimized when the position of the tip end P of the wire W is identified using the conduction block 5. This ensures that even if the conduction block 5 is repeatedly used, the accuracy of identifying the position of the tip end P of the wire W is less likely to decrease. A tungsten-containing alloy (for example, an alloy containing copper and tungsten) is exemplified as a material that is high in wear resistance to arc discharge. Therefore, the conduction block 5 may be formed of a tungsten-containing alloy (for example, an alloy containing copper and tungsten).
From the viewpoint of identifying the position of the tip end P of the wire W with high accuracy (or from the viewpoint of eliminating or minimizing wear of the conduction block 5 due to contact of the tip end P of the wire W with the conduction block 5), the conduction block 5 may be made of a material that is higher in hardness (for example, Shore hardness) than the material of the member of the table 2 that contacts the workpiece D (for example, the pallet 212, to which the workpiece D is attached).
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The wire supply device 6 may supply the wire W in order to correct the position of the tip end P of the wire W after the position of the tip end P of the wire W has been identified. The wire supply device 6 may also pull back the wire W in order to correct the position of the tip end P of the wire W after the position of the tip end P of the wire W has been identified. In other words, the wire supply device 6 may be capable of selectively performing supply of the wire W and pull-back of the wire W in order to correct the position of the tip end P of the wire W.
In a case where the machine tool 1A includes the wire supply device 6, the position of the tip end P of the wire W can be physically corrected by supplying the wire W or pulling back the wire W.
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The machine tool 1A includes a drive device 11 and a control device 7, which controls the drive device 11.
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The control device 7 may control the wire supply device 6 to make the wire W protrude from the first machining head 3. The control device 7 may also control the wire supply device 6 to pull back the wire W to the first machining head 3. The control device 7 may also control the power supply 13 to change the voltage applied between the wire W and the table 2.
In the example illustrated in
The control device 7 includes: a computer 71, which executes a program; and a storage device 73. For example, a program executed by the computer 71 is stored in the storage device 73. Additionally, data may be stored in the storage device 73.
In the examples illustrated in
The first control mode is a mode in which contact between the tip end P of the wire
W and the conduction block 5 is detected in response to the flow of current through the first electric circuit C1 including the wire W, the conduction block 5, and the cable 14 (the a current flowing through the first electric circuit C1 during the first control mode will be hereinafter referred to as “first current”). The first electric circuit C1 includes, for example, the power supply 13, the wire W, the conduction block 5, the pallet 212, the slip ring 26 (see
The detection of the contact between the tip end P of the wire W and the conduction block 5 is performed based on the flow of the first current (in other words, short-circuit current) through the first electric circuit C1 including the wire W and the conduction block 5. For example, the control device 7 monitoring the power supply 13 receives, from the power supply 13, a signal indicating that the first current (in other words, a short-circuit current) is flowing through the first electric circuit C1. In response to the control device 7 receiving this signal, the control device 7 may detect contact between the tip end P of the wire W and the conduction block 5. Alternatively, from a sensor S (if necessary, see
While the first control mode is being executed, the control device 7 may transmit a control command to the drive device 11 through a signal line 76a. The drive device 11, receiving the control command from the control device 7, moves the first machining head 3 with respect to the conduction block 5 so that the tip end P of the wire W supported by the first machining head 3 contacts the conduction block 5 (moving step). For example, the drive device 11 moves the first machining head 3 in the direction indicated by an arrow AR1 in
While the first control mode is being executed, the control device 7 identifies the timing at which the first electric circuit C1 is switched from the open state to the closed state, in other words, the timing at which the tip end P of the wire W and the conduction block 5 are brought into contact with each other (timing identifying step). Also while the first control mode is being executed, the control device 7 calculates the actual position of the first machining head 3 at the above-described timing (position calculation step). The control device 7 stores the calculated actual position (in other words, position data) of the first machining head 3 in the storage device 73.
After executing the first control mode, the control device 7 may calculate, based on the actual position F of the first machining head 3 at the above-described timing and based on the position of the conduction block 5, a position displacement amount between the actual position of the tip end P of the wire W and the imaginary position P0 of the tip end of the wire W (position displacement amount calculation step).
A first example of the position displacement amount calculation step will be described by referring to
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A second example of the position displacement amount calculation step will be described by referring to
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The control device 7 calculates the coordinates (X2, Y2, Z2-Lt) of the imaginary position P0 of the tip end of the wire W based on the coordinates of the actual position F of the first machining head 3 and the target value Lt of the protruding length of the wire. The control device 7 calculates the coordinates (Xc, Y2, Z2-Lt) of an intersection point of the first inclined surface 52a and a straight line N1, which passes through the imaginary position P0 and is parallel to the X axis.
Based on the difference between the X coordinate (Xc) of the intersection point and the X coordinate (X2) of the actual position F of the first machining head 3 or the X coordinate (X2) of the imaginary position of the tip end of the wire W, the control device 7 calculates the first position displacement amount V1 (=Xc−X2) between the actual position of the tip end P of the wire W and the imaginary position P0 of the tip end of the wire W in the direction parallel to the first direction DR1. It is to be noted that in a case where the protruding length L1 of the wire W is calculated in advance (see the above-described first example), the “protruding length L1 of the wire W” may be used instead of the “target value Lt of the protruding length of the wire” in the calculation of the first position displacement amount V1 in the second example.
A third example of the position displacement amount calculation step will be described by referring to
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The control device 7 calculates the coordinates (X3, Y3, Z3-Lt) of the imaginary position P0 of the tip end of the wire W based on the coordinates of the actual position F of the first machining head 3 and the target value Lt of the protruding length of the wire. The control device 7 calculates coordinates (X3, Yc, Z3-Lt) of an intersection point of the second inclined surface 52b and a straight line N2, which passes through the imaginary position P0 and is parallel to the Y axis.
Based on the difference between the Y coordinate (Yc) of the intersection point and the Y coordinate (Y3) of the actual position F of the first machining head 3 or the Y coordinate (Y3) of the imaginary position P0 of the tip end of the wire W, the control device 7 calculates the second position displacement amount V2 (=Yc−Y3) between the actual position of the tip end P of the wire W and the imaginary position P0 of the tip end of the wire W in the direction parallel to the second direction DR2. It is to be noted that in a case where the protruding length L1 of the wire W is calculated in advance (see the above-described first example), the “protruding length L1 of the wire W” may be used instead of the “target value Lt of the protruding length of the wire” in the calculation of the second position displacement amount V2 in the third example.
A fourth example of the position displacement amount calculation step will be described by referring to
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The X coordinate of a second intermediate point, which is an intermediate point between the actual position of the tip end P of the wire W at the second timing and the actual position of the tip end P of the wire W at the fourth timing is the same as the X coordinate (Xe) of the second surface PL2. Further, the X coordinate of the second intermediate point coincides with the X coordinate of the actual position of the tip end P of the wire W when the first machining head 3 is at the first intermediate point.
From the description above, based on the difference between the X coordinate (Xe) of the second intermediate point and the X coordinate (=(X2+X2′)/2) of the first intermediate point, the control device 7 calculates the first position displacement amount V1 (=Xe−(X2+X2′)/2) between the actual position of the tip end P of the wire W and the imaginary position P0 of the tip end of the wire W in the direction parallel to the first direction DR1.
A fifth example of the position displacement amount calculation step will be described by referring to
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The Y coordinate of a fourth intermediate point, which is an intermediate point between the actual position of the tip end P of the wire W at the third timing and the actual position of the tip end P of the wire W at the fifth timing is the same as the Y coordinate (Ye) of the third surface PL3. Further, the Y coordinate of the fourth intermediate point coincides with the Y coordinate of the actual position of the tip end P of the wire W when the first machining head 3 is at the third intermediate point.
From the description above, based on the difference between the Y coordinate (Ye) of the fourth intermediate point and the Y coordinate (=(Y3+Y3′)/2) of the third intermediate point, the control device 7 calculates the second position displacement amount V2 (=Ye−(Y3+Y3′)/2) between the actual position of the tip end P of the wire W and the imaginary position P0 of the tip end of the wire W in the direction parallel to the second direction DR2.
In the above description, five examples (in other words, five algorithms) of the position displacement amount calculation step have been described. It is to be noted, however, that the algorithm in the position displacement amount calculation step will not be limited to the above-described first to fifth examples. In other words, an algorithm other than the above-described first to fifth examples may be employed as the algorithm in the position displacement amount calculation step. First Position Correction Step
After the above-described position displacement amount V has been calculated, the control device 7 may execute a first position correction step of correcting the position of the tip end P of the wire W based on the calculated position displacement amount V. For example, the control device 7 transmits a control command corresponding to the calculated position displacement amount V to the wire supply device 6. The wire supply device 6, receiving the control command from the control device 7, supplies the wire W by an amount corresponding to the position displacement amount V or pulls back the wire W by the amount corresponding to the position displacement amount V. In this manner, the protruding length L1 of the wire W protruding from the first machining head 3 is corrected by an amount corresponding to the position displacement amount V.
After the above-described first position displacement amount V1 has been calculated, the control device 7 may, based on the calculated first position displacement amount V1, correct the estimated relative position F0 of the first machining head 3 with respect to the tip end P of the wire W in the direction parallel to the first direction DR1 (second position correction step). In the example illustrated in
Alternatively or additionally, after the above-described second position displacement amount V2 has been calculated, the control device 7 may, based on the calculated second position displacement amount V2, correct the estimated relative position F0 of the first machining head 3 with respect to the tip end P of the wire W in the direction parallel to the second direction DR2 (third position correction step).
The second control mode is a mode in which additive machining is performed on the workpiece D by supplying current (the current flowing through the second electric circuit C2 during the second control mode will be hereinafter referred to as “second current”) from the power supply 13 to the second electric circuit C2 including the wire W, a gap G (see
The second electric circuit C2 includes the power supply 13, the wire W, the gap G between the tip end P of the wire W and the workpiece D, the workpiece D, the pallet 212, the slip ring 26 (see
During the execution of the second control mode, the second current supplied from the power supply 13 flows through the wire W, the gap G between the tip end P of the wire W and the workpiece D, and the cable 14. The flow of the second current through the gap G is realized by a discharge phenomenon between the tip end P of the wire W and the workpiece D. The wire W is melted by the heat generated at the time of discharge, and a molten material generated from the tip end P of the wire W is added to the workpiece D.
During the execution of the second control mode, the control device 7 may transmit a control command to the drive device 11. The drive device 11, receiving the control command from the control device 7, moves the first machining head 3 with respect to the workpiece D (in other words, the table 2, which supports the workpiece D). In this manner, an added object having a desired shape can be added to the workpiece D. During the execution of the second control mode, the control device 7 may transmit a control command to the wire supply device 6. The wire supply device 6, receiving the control command from the control device 7, supplies the wire W to the first machining head 3 so that the wire W is fed out of the first machining head 3. In this case, the wire W is fed out of the first machining head 3 by an amount corresponding to the amount of the wire W consumed in additive machining.
In the examples illustrated in
After the position of the tip end P of the wire W has been corrected (in other words, after the above-described first position correction step has been executed), the above-described second control mode may be executed so that the molten material generated from the tip end P of the wire W exposed from the first machining head 3 is added to the workpiece D, which is supported by the table 2. In a case where the second control mode is executed after the position of the tip end P of the wire W has been corrected, the accuracy of the position or shape of the added object added to the workpiece D is improved.
Alternatively or additionally, after the estimated relative position F0 of the first machining head 3 with respect to the tip end P of the wire W has been corrected (in other words, after the above-described second position correction step and/or the above-described third position correction step have/has been performed), the above-described second control mode may be performed so that the molten material generated from the tip end P of the wire W exposed from the first machining head 3 is added to the workpiece D, which is supported by the table 2. In a case where the second control mode is executed after the estimated relative position F0 of the first machining head 3 with respect to the tip end P of the wire W has been corrected, the accuracy of the position or shape of the added object added to the workpiece D is improved.
The control device 7 may be capable of executing a third control mode. The third control mode is executed, for example, after the second control mode has been executed.
The third control mode is a mode in which the workpiece D is cut by driving the tool 41, which is supported by the second machining head 4. As a result of the third control mode being executed, the tool 41, which is supported by the second machining head 4, is driven, and the workpiece D, which is supported by the table 2 (more specifically, the added object added to the workpiece D by additive machining) is cut by the driven tool 41.
During the execution of the third control mode, the control device 7 transmits a control command to the drive device 11. The drive device 11, receiving the control command from the control device 7, moves the second machining head 4 (for example, the head mount E to which the second machining head 4 is attached) with respect to the workpiece D (in other words, the table 2, which supports the workpiece D). Also during the execution of the third control mode, the control device 7 transmits a control command to the tool drive device 115. The tool drive device 115, receiving the control command from the control device 7, rotates the tool 41 about the third axis AX3. In this manner, the workpiece D (for example, an added object added to the workpiece D) is cut by the tool 41.
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Next, a workpiece support device B of a machine tool 1 according to a second embodiment will be described by referring to
The workpiece support device B of the machine tool 1 according to the second embodiment is a workpiece support device of a machine tool that includes the first machining head 3, which adds a molten material generated from the tip end P of the wire W to the workpiece D. The first machining head 3 of the machine tool 1 supports the wire W in a state in which the tip end P of the wire W is exposed. The machine tool 1 may be the machine tool 1A according to the first embodiment, or may be another machine tool. An example of another machine tool is provided with: the first machining head 3, which adds a molten material generated from the tip end P of the wire W to the workpiece D; the second machining head 4, which supports the tool 41, which cuts the workpiece D; the drive device 11, which moves the first machining head 3 and/or the second machining head 4; and the power supply 13, which supplies current to the wire W.
As illustrated in
The pallet 212 constitutes a part of the table 2 of the machine tool 1 and supports a workpiece D, which is an object to be machined. In the example illustrated in
The conduction block 5 identifies the position of the tip end P of the wire W supported by the first machining head 3. The conduction block 5 may be attached to the pallet 212. In other words, a first component constituting the conduction block 5 may be attached to a second component constituting the pallet 212. In this case, the first component may be provided in a state of being separated from the second component (in this case, the first component is attached to the second component afterward), or the first component may be provided in a state of being attached to the second component. Alternatively, the conduction block 5 may be integrally formed with the pallet 212.
The conduction block 5 has the first surface 51, which identifies the protruding length L1 of the wire W protruding from the first machining head 3; and the inclined surface 52, which is disposed so as to be inclined with respect to the first surface 51 and identifies the displacement amount of the tip end P of the wire W from the imaginary center axis AX of the wire W. The inclined surface 52 may have: the first inclined surface 52a, which identifies the first displacement amount indicating the degree of displacement of the tip end P of the wire W from the imaginary center axis AX of the wire W in the first direction DR1; and the second inclined surface 52b, which identifies the second displacement amount indicating the degree of displacement of the tip end P of the wire W from the imaginary center axis AX of the wire W in the second direction DR2.
The first machining head 3, the pallet 212, the conduction block 5, the table 2, the first surface 51, and the inclined surface 52 have already been described in detail in the first embodiment. Therefore, repetitive description of these parts and members will be omitted. It is to be noted that the conduction block 5 illustrated in
In a state in which the workpiece support device B of the machine tool 1 according to the second embodiment is attached to another component (for example, the table member 210) of the machine tool 1, the conduction block 5 functions as a part of the first electric circuit C1, which is switched from an open state to a closed state by contact between the tip end P of the wire W and the conduction block 5. This ensures that the machine tool 1 in which the workpiece support device B according to the second embodiment is incorporated provides effects identical to the effects provided by the machine tool 1A according to the first embodiment.
Also, the workpiece support device B of the machine tool 1 according to the second embodiment includes the pallet 212 and the conduction block 5. With this configuration, the workpiece support device B has a first function of supporting the workpiece D and a second function of identifying the position of the tip end P of the wire W. Also in the second embodiment, since both the workpiece D and the conduction block 5 are disposed on the pallet 212, inconsistency is less likely to occur between position information of the conduction block 5 based on the pallet 212 and position information of the workpiece D based on the pallet 212.
Also in the second embodiment, since the conduction block 5 is disposed on the pallet 212, the conduction block 5 is automatically replaced by replacing the pallet 212.
The workpiece support device B of the machine tool 1 according to the second embodiment may be such a workpiece support device of a machine tool that includes the above-described first machining head 3 and the second machining head 4, which supports the tool 41, which cuts the workpiece D. In this case, the pallet 212 consistently supports the workpiece D during additive machining of the workpiece D performed using the first machining head 3 and during cutting of the workpiece D performed using the second machining head 4.
In a case where the pallet 212 supporting the workpiece D during additive manufacturing and the pallet 212 supporting the workpiece D during cutting are the same, the surface of the workpiece D (more specifically, the surface of the added object added to the workpiece D) can be cut into a desired shape with high accuracy in the cutting performed after the additive manufacturing.
Next, a method of operating the machine tool 1 according to an embodiment will be described by referring to
In the method of operating the machine tool 1 according to the embodiment, the machine tool 1 may be the machine tool 1A according to the first embodiment or may be another machine tool.
The machine tool 1 includes: the table 2, which supports the workpiece D; the first machining head 3, which supports the wire W in a state in which the tip end P of the wire W is exposed and adds a molten material generated from the tip end P of the wire W to the workpiece D, which is supported by the table 2; the second machining head 4, which supports the tool 41, which cuts the workpiece D, which is supported by the table 2; the power supply 13, which supplies current to the wire W; the conduction block 5, which is disposed on the table 2 and identifies the position of the tip end P of the wire W; the drive device 11, which moves the power supply 13 with respect to the table 2 so that the tip end P of the wire W exposed from the first machining head 3 and the conduction block 5, which is disposed on the table 2, are brought into contact with each other; and the first electric circuit C1, which is switched from the open state to the closed state by contact between the tip end P of the wire W exposed from the first machining head 3 and the conduction block 5, which is disposed on the table 2.
As illustrated in
First step ST1 (first moving step) may include moving the first machining head 3 to a first standby position (sub-step ST1-1). The first standby position is, for example, a position set in advance by the control device 7 such that an extension line of the imaginary center axis AX of the wire W supported by the first machining head 3 intersects the first surface 51 of the conduction block 5.
First step ST1 (first moving step) may also include moving the first machining head 3 from the first standby position toward the first surface 51 of the conduction block 5 in a direction parallel to the imaginary center axis AX of the wire W (sub-step ST1-2). At sub-step ST1-2, the control device 7 transmits a first control command to the drive device 11. The drive device 11, receiving the first control command from the control device 7, moves the first machining head 3 from the first standby position toward the first surface 51 in the direction parallel to the imaginary center axis AX of the wire W.
As illustrated in
As illustrated in
At second step ST2, the first timing at which the first electric circuit C1 switches from the open state to the closed state is identified. Second step ST2 is a first timing identifying step.
At second step ST2 (first timing identifying step), the control device 7 identifies the first timing at which the first electric circuit C1 is switched from the open state to the closed state due to the contact between the tip end P of the wire W and the conduction block 5 (more specifically, the first surface 51). More specifically, the control device 7 identifies the first timing at which the first electric circuit C1 is switched from the open state to the closed state based on a change in the signal received from the first electric circuit C1 (for example, the power supply 13 and the sensor S). For example, in response to receiving, from the first electric circuit C1 (for example, the power supply 13 and the sensor S), a signal indicating that the first current is flowing through the first electric circuit C1, the control device 7 identifies the first timing at which the first electric circuit C1 is switched from the open state to the closed state.
Second step ST2 (first timing identifying step) is executed during the execution of first step ST1 (first moving step). For example, at second step ST2, when the first timing has been identified by the control device 7, first step ST1 (first moving process) may end. In other words, by the contact between the tip end P of the wire W and the conduction block 5, the movement of the first machining head 3 may be automatically stopped, or the function of automatically returning the first machining head 3 to the first standby position may be turned on (in other words, a skip function may be turned on).
At third step ST3, the control device 7 executes a step (first position calculation step) of calculating the actual position of the first machining head 3 at the first timing (that is, the position coordinates of the first machining head 3). The control device 7 stores the position of the first machining head 3 at the first timing in the storage device 73.
It is to be noted that the first machining head 3 is preferably returned to the first standby position after the execution of third step ST3 or before the execution of third step ST3.
At fourth step ST4, the position displacement amount V between the actual position of the tip end P of the wire W and the imaginary position P0 of the tip end of the wire W in the direction along the imaginary center axis AX is calculated. Fourth step ST4 is a position displacement amount calculation step.
At fourth step ST4 (position displacement amount calculation step), based on the actual position F of the first machining head 3 at the first timing and the position of the conduction block 5 (more specifically, the position of the first surface 51) at the first timing, the control device 7 calculates the position displacement amount V between the actual position of the tip end P of the wire W and the imaginary position P0 of the tip end of the wire W in the direction along the imaginary center axis AX.
The algorithm for calculating the position displacement amount V has already been described in the “first example of the position displacement amount calculation step”, described above. Therefore, repetitive description of the algorithm for calculating the position displacement amount V will be omitted. It is to be noted that as understood from
The control device 7 may use the calculated position displacement amount Vas a first correction amount Q. In this case, the position of the tip end P of the wire W is corrected by executing the first position correction step, described later, so that the protruding length L1 of the wire W protruding from the first machining head 3 approaches the target value Lt.
Alternatively, as illustrated in
In the example illustrated in
At fifth step ST5, the position of the tip end P of the wire Win the direction along the imaginary center axis AX of the wire W is corrected. Fifth step ST5 is a first position correction step.
At fifth step ST5 (first position correction step), the control device 7 transmits a control command corresponding to the first correction amount Q to the wire supply device 6. The wire supply device 6, receiving the control command from the control device 7, supplies the wire W by an amount corresponding to the first correction amount Q or pulls back the wire W by an amount corresponding to the first correction amount Q. In this manner, the protruding length L1 of the wire W protruding from the first machining head 3 is corrected by an amount corresponding to the position displacement amount V.
At fifth step ST5, in a case where the position displacement amount V (=Lt−L1) is a positive value, the wire supply device 6, receiving the control command corresponding to the first correction amount Q, may supply the wire W to the first machining head 3 for a time period proportional to the absolute value of the first correction amount Q. In this manner, the protruding length L1 of the wire W protruding from the first machining head 3 approaches the target value Lt of the protruding length of the wire.
In contrast, at fifth step ST5, in a case where the position displacement amount V (=Lt−L1) is a negative value, the wire supply device 6 may pull back the wire W from the first machining head 3 for a time period proportional to the absolute value of the first correction amount Q. In this manner, the protruding length L1 of the wire W protruding from the first machining head 3 approaches the target value Lt of the protruding length of the wire.
After the position of the tip end P of the wire W has been corrected at fifth step ST5, the control device 7 may execute first step ST1 to fourth step ST4 again. Alternatively, after the position of the tip end P of the wire W has been corrected at fifth step ST5, the control device 7 may execute sixth step ST6.
As illustrated in
Sixth step ST6 (second moving step) may include moving the first machining head 3 to a second standby position (sub-step ST6-1). The second standby position is, for example, a position set in advance by the control device 7 such that a straight line passing through the tip end P of the wire W supported by the first machining head 3 and parallel to the first direction DR1 intersects the first inclined surface 52a.
Also, sixth step ST6 (second moving step) may include moving the first machining head 3 from the second standby position toward the first inclined surface 52a of the conduction block 5 in the direction parallel to the first direction DR1 (sub-step ST6-2). At sub-step ST6-2, the control device 7 transmits a second control command to the drive device 11. The drive device 11, receiving the second control command from the control device 7, moves the first machining head 3 from the second standby position toward the first inclined surface 52a in the direction parallel to the first direction DR1.
At seventh step ST7, the second timing at which the first electric circuit C1 is switched from the open state to the closed state is identified. Seventh step ST7 is a second timing identifying step.
At seventh step ST7 (second timing identifying step), the control device 7 identifies the second timing at which the first electric circuit C1 is switched from the open state to the closed state due to the contact between the tip end P of the wire W and the first inclined surface 52a of the conduction block 5.
Seventh step ST7 (second timing identifying step) is executed during the execution of sixth step ST6 (second moving step). For example, at seventh step ST7, when the second timing has been identified by the control device 7, sixth step ST6 (second moving step) may end. In other words, the movement of the first machining head 3 may be automatically stopped by the contact between the tip end P of the wire W and the conduction block 5, or the function of automatically returning the first machining head 3 to the second standby position may be turned on (in other words, the skip function may be turned on).
At eighth step ST8, the control device 7 executes a step (second position calculation step) of calculating the actual position of the first machining head 3 at the second timing (that is, the position coordinates of the first machining head 3). The control device 7 stores the position of the first machining head 3 at the second timing in the storage device 73.
It is to be noted that the first machining head 3 is preferably returned to the second standby position after the execution of eighth step ST8 or before the execution of eighth step ST8.
At ninth step ST9, the first machining head 3 is moved with respect to the conduction block 5 so that the tip end P of the wire W contacts the third inclined surface 52c of the conduction block 5 (see an arrow AR3 in
Ninth step ST9 may include moving the first machining head 3 to a third standby position (sub-step ST9-1). The third standby position is, for example, a position set in advance by the control device 7 such that a straight line passing through the tip end P of the wire W supported by the first machining head 3 and parallel to the first direction DR1 intersects with the third inclined surface 52c.
Also, ninth step ST9 may include moving the first machining head 3 from the third standby position toward the third inclined surface 52c of the conduction block 5 in the direction parallel to the first direction DR1 (sub-step ST9-2).
At tenth step ST10, the fourth timing at which the first electric circuit C1 is switched from the open state to the closed state is identified. Tenth step ST10 is a fourth timing identifying step.
At tenth step ST10 (fourth timing identifying step), the control device 7 identifies the fourth timing at which the first electric circuit C1 is switched from the open state to the closed state due to the contact between the tip end P of the wire W and the third inclined surface 52c of the conduction block 5.
At eleventh step ST11, the control device 7 executes a step (fourth position calculation step) of calculating the actual position F′ of the first machining head 3 (that is, the position coordinates of the first machining head 3) at the fourth timing. The control device 7 stores the position of the first machining head 3 at the fourth timing in the storage device 73.
It is to be noted that the first machining head 3 is preferably returned to the third standby position after the execution of eleventh step ST11 or before the execution of eleventh step ST11.
At twelfth step ST12, the first position displacement amount V1 between the actual position of the tip end P of the wire W and the imaginary position P0 of the tip end of the wire W in the direction parallel to the first direction DR1 is calculated. Twelfth step ST12 is a first position displacement amount calculation step.
At twelfth step ST12 (first position displacement amount calculation step), at least based on the actual position F of the first machining head 3 at the second timing and the position of the conduction block 5, the control device 7 calculates the first position displacement amount V1 between the actual position of the tip end P of the wire W and the imaginary position P0 of the tip end of the wire W in the direction parallel to the first direction DR1. The first position displacement amount V1 corresponds to an amount indicating the degree to which the tip end P of the wire W is displaced from the imaginary center axis AX in the first direction DR1.
The algorithm for calculating the first position displacement amount V1 has already been described in the “second example of the position displacement amount calculation step” or the “fourth example of the position displacement amount calculation step”. Therefore, repetitive description of the algorithm for calculating the first position displacement amount V1 will be omitted. It is to be noted that in a case where the “second example of the position displacement amount calculation step” is employed as the algorithm for calculating the first position displacement amount V1, ninth step ST9 to eleventh step ST11 may be omitted.
At thirteenth step ST13, the first machining head 3 is moved with respect to the conduction block 5 so that the tip end P of the wire W contacts the second inclined surface 52b of the conduction block 5.
At fourteenth step ST14, the third timing at which the first electric circuit C1 is switched from the open state to the closed state is identified. Fourteenth step ST14 is a third timing specifying step.
At fourteenth step ST14 (third timing specifying step), the control device 7 specifies the third timing at which the first electric circuit C1 is switched from the open state to the closed state due to the contact between the tip end P of the wire W and the second inclined surface 52b of the conductive block 5.
At fifteenth step ST15, the control device 7 executes a step (third position calculation step) of calculating the actual position of the first machining head 3 at the third timing (that is, the position coordinates of the first machining head 3). The control device 7 stores the position of the first machining head 3 at the third timing in the storage device 73.
At sixteenth step ST16, the first machining head 3 is moved with respect to the conductive block 5 so that the tip end P of the wire W contacts the fourth inclined surface 52d of the conductive block 5.
At seventeenth step ST17, the fifth timing at which the first electric circuit C1 is switched from the open state to the closed state is identified. Seventeenth step ST17 is a fifth timing specifying step.
At seventeenth step ST17 (fifth timing specifying step), the control device 7 specifies the fifth timing at which the first electric circuit C1 is switched from the open state to the closed state due to the contact between the tip end P of the wire W and the fourth inclined surface 52d of the conductive block 5.
At eighteenth step ST18, the control device 7 executes a step (fifth position calculation step) of calculating the actual position F′ of the first machining head 3 (that is, the position coordinates of the first machining head 3) at the fifth timing. The control device 7 stores the position of the first machining head 3 at the fifth timing in the storage device 73.
At nineteenth step ST19, the second position displacement amount V2 between the actual position of the tip end P of the wire W and the imaginary position P0 of the tip end of the wire in the direction parallel to the second direction DR2 is calculated. Nineteenth step ST19 is a second positional displacement amount calculation step.
At nineteenth step ST19 (second positional displacement amount calculation step), at least based on the actual position F of the first machining head 3 at the third timing and the position of the conductive block 5, the control device 7 calculates the second position displacement amount V2 between the actual position of the tip end P of the wire W and the imaginary position P0 of the tip end of the wire W in the direction parallel to the second direction DR2. The second position displacement amount V2 corresponds to an amount indicating the degree to which the tip end P of the wire W is displaced from the imaginary center axis AX in the second direction DR2.
The algorithm for calculating the second position displacement amount V2 has already been described in the “third example of the position displacement amount calculation step” or the “fifth example of the position displacement amount calculation step”. Therefore, repetitive description of the algorithm for calculating the second position displacement amount V2 will be omitted. It is to be noted that in a case where the “third example of the position displacement amount calculation step” is employed as the algorithm for calculating the second position displacement amount V2, sixteenth step ST16 to eighteenth step ST18 may be omitted.
At twentieth step ST20, the control device 7 corrects the estimated relative position F0 of the first machining head 3 with respect to the tip end P of the wire W in the direction parallel to the first direction DR1 based on the calculated first position displacement amount V1. Twentieth step ST20 is a second position correction step. By the correction, the position control of the first machining head 3 is performed in the subsequent additive machining step in consideration of the fact that the tip end P of the wire W is displaced from the imaginary center axis AX in the first direction DR1 by the first position displacement amount V1.
At twenty-first step ST21, based on the calculated second position displacement amount V2, the control device 7 corrects the estimated relative position F0 of the first machining head 3 with respect to the tip end P of the wire W in the direction parallel to the second direction DR2. Twenty-first ST21 is a third position correction step. By the correction, the position control of the first machining head 3 is performed in the subsequent additive machining step in consideration of the fact that the tip end P of the wire W is displaced from the imaginary center axis AX in the second direction DR2 by the second position displacement amount V2.
At twenty-second step ST22, a molten material generated from the tip end P of the wire W supported by the first machining head 3 is added to the workpiece D, which is supported by the table 2. Twenty-second step ST22 is an additive machining step.
At twenty-second step ST22 (additive machining step), current is supplied from the power supply 13 to the second electric circuit C2, which includes the wire W, the gap G between the tip end P of the wire W and the workpiece D, and the cable 14, causing arc discharge to be generated between the tip end P of the wire W and the workpiece D. The wire W is melted by the heat generated by the arc discharge, and the resulting molten material is added to the workpiece D.
Twenty-third step ST23, the workpiece D, which is supported by the table 2, is cut. Twenty-third step ST23 is a cutting step.
Twenty-third step ST23 (cutting step), the workpiece D (for example, an added object added to the workpiece D) is cut by the tool 41, which is supported by the second machining head 4. Program and Non-transitory Computer-readable Storage Medium Storing the Program
The storage device 73 illustrated in
The above-described program causes the machine tool 1, which includes the first machining head 3, the second machining head 4, and the table 2, to execute operations including the following steps (1) to (6). Also, when the program is executed by the computer 71, which is included in the control device 7 of the machine tool 1, the machine tool 1, which includes the first machining head 3, the second machining head 4, and the table 2, executes the following steps (1) to (6). (1) relatively moving the first machining head 3 supporting the wire W with respect to the conduction block 5, which is disposed on the table 2, so that the tip end P of the wire W exposed from the first machining head 3 supporting the wire W is brought into contact with the conduction block 5, which is disposed on the table 2;
The above-described step (1) may include the following step (1A) and/or step (1B). (1A) relatively moving the first machining head 3 of the drive device 1 with respect to the conduction block 5, which is disposed on the table 2 of the drive device 1, so that the tip end P of the wire W supported by the first machining head 3 is brought into contact with the first surface 51 of the conduction block 5.
The above-described step (2) may include the following step (2A) and/or step (2B).
The above-described step (3) may include the following step (3A) and/or step (3B).
The above-described step (4) may include the following step (4A) and/or step (4B).
The above-described program may cause the machine tool 1 to execute operations including the following step (7). Also, when the program is executed by the computer 71, which is included in the control device 7 of the machine tool 1, the machine tool 1 may execute the following step (7).
Further, the above-described program may cause the machine tool 1 to execute operations including at least one of the first step ST1 to the twenty-third step ST23. Also, when the program is executed by the computer 71, which is included in the control device 7 of the machine tool 1, the machine tool 1 may execute at least one of the first step ST1 to the twenty-third step ST23.
The present invention will not be limited to the above-described embodiments, and it is obvious that each embodiment or each modification can be appropriately modified or changed within the scope of the technical idea of the present invention. Also, the various techniques used in each embodiment or each modification can be applied in other embodiment or other modification unless a technical contradiction occurs. Further, the optional or additional configuration(s) in each embodiment or each modification can be omitted as necessary.
For example, in the first embodiment, an example in which the table 2 is tiltable about the first axis AX1 has been described. Alternatively, as illustrated in
In the present disclosure, the term “comprise” and its variations are intended to mean open-ended terms, not excluding any other elements and/or components that are not recited herein. The same applies to the terms “include”, “have”, and their variations.
In the present disclosure, a component suffixed with a term such as “member”, “portion”, “part”, “element”, “body”, and “structure” is intended to mean that there is a single such component or a plurality of such components.
In the present disclosure, ordinal terms such as “first” and “second” are merely used for distinguishing purposes and there is no other intention (such as to connote a particular order) in using ordinal terms. For example, the mere use of “first element” does not connote the existence of “second element”; otherwise, the mere use of “second element” does not connote the existence of “first element”.
In the present disclosure, approximating language such as “approximately”, “about”, and “substantially” may be applied to modify any quantitative representation that could permissibly vary without a significant change in the final result obtained. All of the quantitative representations recited in the present application shall be construed to be modified by approximating language such as “approximately”, “about”, and “substantially”.
In the present disclosure, the phrase “at least one of A and B” is intended to be interpreted as “only A”, “only B”, or “both A and B”.
Obviously, numerous modifications and variations of the present disclosure are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present disclosure may be practiced otherwise than as specifically described herein.
The present application is a continuation application of International Application No. PCT/JP2020/038244, filed Oct. 9, 2020. The contents of this application are incorporated herein by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2020/038244 | Oct 2020 | US |
| Child | 18296376 | US |
