JP4921115B2 - Movement control apparatus for moving body, movement control method for moving body, and movement control apparatus for machine tool - Google Patents

Description

  The present invention, for example, in a machine tool such as a lathe in which a plurality of tools are arranged in parallel on a tool post, a moving body that moves the tool rest as a moving body by overlapping in two orthogonal directions by rapid feed The present invention relates to a movement control apparatus, a movement control method thereof, and a movement control method of a machine tool.

  Conventionally, in a machine tool such as a lathe as described above, when a tool used for machining is switched, a tool switching method as shown in FIGS. 16 and 17, for example, has been adopted. That is, in such a machine tool, the tool post 61 in which a plurality of tools 62A, 62B, and 62C such as a plurality of tools are arranged in parallel corresponds to the workpiece W, and the X-axis direction and the tool 62A that are the forward and backward directions of the tools 62A to 62C. It is movable along the Y-axis direction which is a parallel arrangement direction of ~ 62C. Then, for example, when the tool 62B from which the cutting edge protrudes is skipped and switched to the tool 62C after the processing of the workpiece W by the tool 62A is finished, first, as shown in FIG. Is positioned at a first position P1 having a predetermined gap C with respect to the outer peripheral surface of the workpiece W.

  After that, as shown in FIG. 16B, the tool post 61 is moved in the X-axis direction, and the second tip P <b> 2 where the cutting edge of the skipped tool 62 </ b> B has a predetermined gap C with respect to the outer peripheral surface of the workpiece W. Is positioned. The second position P2 is a via position where interference between the most protruding tool 62B and the workpiece W can be avoided when the tool post 61 is moved in the Y-axis direction. Subsequently, as shown in FIG. 16C, the tool post 61 is moved in the Y-axis direction while skipping the tool 62B, and the cutting edge of the tool 62C is on an extension line in the X-axis direction passing through the center of the workpiece W. Positioned at the third position P3. Further, as shown in FIG. 16D, the tool post 61 is moved forward in the X-axis direction, and the cutting edge of the tool 62C is positioned at a fourth position P4 having a predetermined gap C with respect to the outer peripheral surface of the workpiece W. Is done.

However, in the conventional movement control method, the tool switching operation is changed between the X-axis direction and the Y-axis direction while stopping the tool post 61 at the second position P2 and the third position P3. There is a problem that it takes a long time to move the tool post 61. That is, as shown in FIGS. 17 and 18, the movement time between the first position P1 and the second position P2 is t1, and the movement time between the second position P2 and the third position P3 is t2. If the moving time between the third position P3 and the fourth position P4 is t3, the moving time t0 for tool change is t1 + t2 + t3 even if it is the shortest.

On the other hand, Patent Document 1 describes a tool movement control method in which a moving time is shortened by overlappingly moving a tool in two axial directions in a predetermined time zone. Further, in Patent Document 2, when changing a tool, while moving the tool from the current position to the tool changing position, an approach position for passing the tool while avoiding interference with other members is set. Describes a tool movement control method in which the fast-forward movement in two directions is overlapped without stopping to shorten the movement time. Furthermore, in Patent Document 3, the moving body is moved at a fast feed speed by the first axis driving device to a turning point for avoiding interference with other members, and when the moving body reaches the turning point. There is provided a movement control method for a moving body in which the moving body is gradually moved within the movement time of the second axis driving device at an acceleration / deceleration below the maximum acceleration / deceleration of the first axis driving device to shorten the moving time. Are listed.
JP-A-9-262742 JP 11-104934 A JP 2006-24174 A

However, these conventional movement control methods have the following problems.
That is, Patent Document 1 describes a method of moving a tool in an overlapping manner in two axial directions, but a method of moving a tool by setting a movement path that does not interfere with other members such as a workpiece. Is not disclosed. Therefore, when the method described in Patent Document 1 is applied to the tool switching shown in FIG. 16, there is a possibility that the tool and another member such as a workpiece interfere with each other during the selective movement of the tool.

  In the method described in Patent Document 2, when the fast-forward movements in two directions are actually overlapped, the movement path is curved near the approach position, and the tool does not accurately pass through the approach position. In order to pass the approach position accurately so that the tool does not interfere with other members, it is necessary to temporarily stop and change the two-way fast-forward movement at the approach position, resulting in a reduction in travel time. Can not be.

  Further, in the method described in Patent Document 3, the moving body is simultaneously moved in the biaxial direction, but the moving body is moved in a faraway manner so as to swell in an arcuate locus in the outer region of the linear movement path. Therefore, the moving stroke of the moving body increases, and a wide moving space is required.

  The present invention has been made paying attention to such problems existing in the prior art. The object is to provide a movement control device for a moving body, a control method thereof, and a movement control device for a machine tool capable of moving the moving body in a short time along a short movement path with no risk of interference with other members. There is to do.

In order to achieve the above object, in the invention of claim 1 according to the movement control device for a moving body, the moving body is moved by fast-forwarding on the first axis and on the second axis intersecting the first axis. The driving means in which the fast moving movement in both axial directions overlaps to move the moving body around the predetermined area, and a reference arc inscribed in the first axis and the second axis are provided. a reference arc setting unit that sets, when transition from the said first axis of the moving body on the second shaft, and timing setting means for setting the overlap movement start timing of the rapid traverse of the moving object based on the reference arc, in order to move the moving body at a timing set by the timing setting means, and control means for controlling the operation of said drive means, a plurality of tangent to the reference arc, adjacent A first calculating means for calculating an intersection of matching tangents, and a first axial direction line parallel to the first axis passing through the intersection and a second axial direction parallel to the second axis from the start of movement of the movable body And a second calculating means for calculating a first time and a second time until reaching each line, and the timing setting means is configured such that at least both times are equal when the second time is shorter than the first time. The overlap movement start timing of the moving body is delayed .

  Therefore, according to the present invention, during the movement of the moving body along the direction of the first axis, the moving body is moved in the direction of the second axis according to the set movement start timing, and the approximate arc based on the reference arc. Fast forward while drawing the trajectory. Therefore, it is possible to move the moving body in a short time by fast-forwarding along a moving path that does not cause interference with other members. For this reason, when the present invention is applied to a machine tool, a moving body such as a tool post in the machine tool can be moved and positioned to a predetermined position in a short time without rapid interference with the workpiece. The productivity of the machine can be improved.

  In the present invention, the movement of the moving body includes not only the case where the moving body moves alone, but also another moving body that can move relative to the moving body alone when the moving body is fixed. In other words, it includes cases where both moving bodies move at the same time. In short, it means that the moving body moves relative to other members. In the present invention, the overlap means that the moving body is simultaneously moved in both directions of the first axis and the second axis.

In addition, by setting the overlap movement start timing of the moving body, based on the calculation results of the first and second calculation means, whether the moving track of the moving body passes inside the intersection located outside the reference arc If it passes through the inside of the intersection, the timing setting means corrects the movement trajectory to be outside the intersection. As described above, if the overlap movement start timing is set, the overlap movement start timing is appropriately set regardless of the fast-forward speed and the acceleration / deceleration speed. For this reason, even devices with different fast-forwarding speeds and acceleration / deceleration speeds can be flexibly accommodated.

According to a second aspect of the present invention, in the first aspect of the invention, the plurality of tangents are set at equiangular intervals.
Therefore, the distance between the reference arc and the plurality of intersections can be made equal.

In the invention of claim 3 relating to the movement control method of the moving body, the moving body is moved by fast-forwarding on the first axis and on the second axis intersecting the first axis, and fast-forwarding movement in both axial directions is performed. By moving the moving body around the predetermined area, setting a reference arc inscribed in the first axis and the second axis, and moving the moving body from the first axis to the second axis. When moving to, the fast moving overlap movement start timing of the moving body is set based on the reference arc, a plurality of tangents to the reference arc and intersections of adjacent tangents are calculated, and the moving body moves Calculating a second time and a first time from the start until reaching a first axial direction line parallel to the first axis passing through the intersection and a second axial direction line parallel to the second axis; Time from the first hour If There was characterized by delaying the overlap movement start timing of the moving body so that at least two times are equal.

Therefore, the same effect as that of the first aspect can be obtained.
In the invention of claim 4 relating to the machine tool movement control device, the direction of the first axis and the first axis intersect between the tool rest in which a plurality of tools are arranged in parallel and the tool rest and the workpiece. Drive means for causing relative movement by rapid traverse in the direction of the second axis, and relatively rotating the tool rest around the workpiece by overlapping the rapid traverse in both axial directions; In the machine tool in which the switching of the tool is executed by the operation of the driving unit, the tool has the configuration according to claim 1 or 2, and the moving body in the configuration is the tool post. .

  Therefore, in the machine tool, the same effect as that of the first aspect can be obtained.

  As described above, according to the present invention, it is possible to move the moving body in a fast-forward manner along a path that does not cause interference with other members, and it is possible to improve productivity. .

Hereinafter, embodiments embodying the present invention will be described.
(First embodiment)
First, a first embodiment will be described based on FIGS.

  As shown in FIG. 1, in the machine tool according to the first embodiment, a headstock 22 is installed on a frame 21 so as to be movable in the Z-axis direction, and a main spindle 23 extending in the Z-axis direction is rotatable on the mainstock 22. It is supported by. A rear spindle stock 24 is installed on the frame 21 so as to be movable in the Z-axis direction so as to face the spindle stock 22, and a rear spindle 25 extending in the Z-axis direction is rotatable on the rear spindle stock 24. It is supported. The main shaft 23 and the rear main shaft 25 are attached with a collet 23a (a collet on the rear main shaft 25 side is not shown) capable of gripping the workpiece W.

  As shown in FIG. 1, between the spindle stock 22 and the back spindle stock 24, a tool post 26 as a moving body is placed on the machine frame 21 so as to be orthogonal to the Z-axis direction that is the moving direction of the spindle stock 22. It is installed to be movable in the direction and the Y-axis direction. On the tool post 26, a tool 27 made of a plurality of tools extending in the X-axis direction, which cuts the workpiece W on the spindle 23 from the outer peripheral side, is arranged in parallel at a predetermined interval in the Y-axis direction. Has been.

Next, the configuration of the control device 35 and the like for controlling the operation of the machine tool configured as described above will be described.
As shown in FIG. 2, the control device 35 includes a CPU 36, a ROM 37, a RAM 38, an input unit 39, a display unit 40, a spindle rotation control circuit 41, a spindle feed control circuit 42, a tool feed control circuit 43 constituting a drive unit, A back spindle rotation control circuit 44 and a back spindle feed control circuit 45 are provided. In this embodiment, the CPU 36, ROM 37 and RAM 38 constitute reference arc setting means, timing setting means, first calculation means, second calculation means and control means.

  The input unit 39 is composed of a keyboard having numeric keys and the like, and manually inputs various data and commands related to processing such as data on the type and dimensions of the workpiece W. The display unit 40 includes a display device such as a liquid crystal display.

  The CPU 36 includes a driving motor and the like by outputting operation commands to the spindle rotation control circuit 41, the spindle feed control circuit 42, the tool feed control circuit 43, the back spindle rotation control circuit 44, and the back spindle feed control circuit 45. The spindle 23, the spindle stock 22, the tool post 26, the back spindle 25, via the spindle rotation drive 46, spindle feed drive 47, tool feed drive 48, back spindle rotation drive 49, and back spindle feed drive 50. And the rear headstock 24 and the like are operated.

  The tool feed driving device 48 moves the tool rest 26 with respect to the work W by moving the tool rest 26 in the X-axis direction or the Y-axis direction during the switching operation described later of the tool 27 on the tool rest 26 with respect to the work W. The tool 27 is moved along the two axial directions of the advancing / retreating direction of the tool 27 and the direction in which the tool 27 is arranged. Therefore, the tool feed driving device 48 constitutes a driving means for driving the tool post 26 so as to move in the X-axis and Y-axis directions.

  The ROM 37 stores various control programs for machining the workpiece W. The CPU 36 controls the progress of the program stored in the ROM 37. The RAM 38 temporarily stores a machining program, various types of data that are manually input or calculated by the CPU 36. For example, the RAM 38 stores various data such as a tool pitch related to the various tools 27. That is, when the tool is a tool 27A to 27C composed of the cutting tool shown in FIGS. 5A to 5D, the tool pitch between the tools 27A to 27C, the shank width of each tool 27A to 27C, and each tool 27A to 27C. The RAM 38 is manually input or calculated data regarding various types of processing such as the distance D1, the arrangement pitch D3, the distances D2, D4 indicating the height difference between the cutting edges of the tools 27A to 27C, and the position of the cutting edge. Is stored in a predetermined area.

  Further, in another area of the RAM 38, maximum speed data and acceleration (including deceleration) data for each feed movement speed such as rapid feed and cutting feed of the tool post 26 in the X, Y, and Z axis directions are stored. ing.

  Further, the RAM 38 stores a temporary storage area for temporarily storing calculation results in a program shown in FIG. 6 described later, and the calculation results so that the calculation results can be used for controlling the operation of the tool rest 26. And a working area.

  Next, in the machine tool having the above-described configuration, an operation when the fixed tool 27 made of a tool used for machining the workpiece W is switched will be described. This switching operation is performed by fast-forwarding. As will be described later, for example, as shown in FIGS. 3, 5, and 7, the corners C <b> 1, C <b> 2 are separated from the workpiece W that forms a predetermined region, and the reference of the radii D <b> 1 to D <b> 4 around the workpiece W is used. An arc E1 is set. The cutting edges (tips) of the tools 27 </ b> A to 27 </ b> C are overlapped in accordance with the overlap movement start timing set based on the reference arc E <b> 1 outside the reference arc E <b> 1 in one corner C <b> 1 by the movement of the tool post 26. (Simultaneous movement of X axis and Y axis), moving while drawing an arcuate locus (hereinafter referred to as an approximate arc or approximate arc locus) E2 shown in FIG. 4, and then moving while drawing a linear locus. The corner C2 moves outside the reference arc E1 while drawing an approximate arc locus E2 based on the reference arc E1. In FIG. 5, it is the cutting edge (tip) of the tool 27B that moves along the reference arc E1 outside the workpiece W. Hereinafter, this movement of the cutting edge (tip) is referred to as movement of the tool post 26. I will explain.

  Here, the approximate arc locus E2 of the tool post 26 shown in FIG. 4 is a result of overlapping fast-forwarding movements in the X and Y axis directions. That is, the approximate arc movement of the tool post 26 according to the reference arc E1 is performed in the Y-axis direction or the X-axis direction, which are other directions, respectively, at a predetermined timing when the tool post 26 moves in the X-axis direction or the Y-axis direction. Can be obtained by overlapping the movements. For example, as shown in FIG. 4, when the movement in the X-axis direction, which has started moving in advance, reaches a predetermined timing, the movement in the Y-axis direction is started to start in both the X- and Y-axis directions. Are moved so as to draw an approximate arc locus E2. The reason why the approximate arc locus E2 is formed is as follows. That is, in the movement of the tool post 26 in the X and Y axis directions, if the tool post 26 instantaneously reaches the top speed and the speed is maintained, the approximate arc locus E2 is not formed in FIG. An inclined linear locus is formed. However, in actuality, since an acceleration region and a deceleration region are formed at both ends of the speed region, the approximate arc locus E2 is formed. As is clear from FIG. 4, the overlap time becomes longer as the overlap movement start timing K becomes earlier, the curvature radius of the approximate arc locus E2 becomes larger, and as the overlap movement start timing K becomes later, the approximate arc locus becomes longer. The radius of curvature of E2 becomes smaller.

  Now, as shown in FIGS. 5 (a) and 5 (b), tools 27A to 27C (shown as rectangles in the drawing for simplification) are arranged in parallel along, for example, the Y-axis direction. When the switching movement is made along the axial direction, the tool post 26 takes into account the mounting error of the tool 27 in order to avoid interference between the most projecting tool 27 (27B in this figure) and the workpiece W. Then, it is retracted in the X-axis direction so that the gap C is secured. At this time, the positions of the tools 27A to 27C and the tool post 26 in the X-axis direction are set as the retracted position, and the retracted position is set as the end of the movement range in the X-axis direction. Therefore, the amount of movement in the X-axis direction is determined according to the amount of protrusion of the most protruding tool 27B. Further, the amount of movement in the Y-axis direction is determined according to the distance between the tools 27 to be switched.

  5 (a) and 5 (b), the tool is switched from the left tool 27A to the right tool 27B or 27C by the leftward movement of the tool post 26. Here, when the tool 27B that protrudes most backward in the movement direction with respect to the cutting edge of the tool 27A is adjacent, the distance D1 between the cutting edge of the tool 27A and the outer peripheral surface of the tool 27B and the retreat movement start position. Based on the retraction distance D2 to the retreat position, a reference arc E1 (a reference arc on the right side in FIG. 3) having a shorter distance D1 or D2 as a radius is set. Then, the tool post 26 moves outside the reference arc E1 while drawing an approximate arc locus E2 based on the reference arc E1. However, as shown in FIG. 5B, when the radius of the reference arc E1 is D1, since the radius D1 is shorter than the retreat distance D2, the tool post 26 first has a substantially difference between the separation distance D1 and the retreat distance D2. After retreating linearly in the X-axis direction, it moves according to the reference arc E1.

Next, FIGS. 5C and 5D show an operation in which the tool 27 to be switched approaches the work W from the retracted position when the tool 27 switches the tool along the Y-axis direction.
That is, the tool post 26 has been moved to the retracted position. Based on the arrangement pitch D3 of the tools 27A to 27C and the approach distance D4 from the retracted position to the position where the gap C is secured between the cutting edge and the workpiece W, the shorter distance D3 or D4 is defined as the radius. The reference arc E1 is set. Then, the tool post 26 moves outside the reference arc E1 while drawing an approximate arc locus E2 based on the reference arc E1. However, when the moving radius is D3, since the moving radius is smaller than the approach distance D4, first, after the tool post 26 approaches while drawing the approximate arc locus E2 according to the reference arc E1, there is almost a difference between the approach distance D4 and the arrangement pitch D3. Only approaches the X axis direction linearly.

  As described above, when the tools are switched, the reference arc E1 is obtained by comparing the separation distance D1 and the retreat distance D2, the arrangement pitch D3 and the approach distance D4, and the tools 27A to 27C do not interfere with the workpiece W. It can be moved fast forward outside E1.

  Next, the procedure of the switching operation of the tool 27 will be described. FIG. 6 shows a routine for setting the overlap movement start timing K. In this routine, the program stored in the ROM 37 of FIG. 2 proceeds under the control of the CPU 36.

  That is, when a predetermined operation for tool switching is performed in the input unit 39 shown in FIG. 2, the radii D1 to D4 of the reference arc E1 in step S1 (hereinafter, “step” is omitted) shown in FIG. Is calculated, and the data of the radii D1 to D4 are stored in the working area of the RAM 38. The reference arc E1 is set so as to be inscribed in the first axis and the second axis that are the movement path of the tool post 26. When the setting of the reference arc E1 is completed, the process for setting the overlap movement start timing is then performed so that the approximate arc locus E2 of the tool post 26 is set outside the reference arc E1 according to the reference arc E1. Executed.

  That is, in S <b> 2, in each corner portion C <b> 1, C <b> 2, the X-axis or Y-axis that the tool post 26 moves first is the first axis, and the Y-axis or X-axis that moves later is the second axis. The operation start timing in the axial direction is set to a predetermined value. For example, in FIG. 3, in the first corner portion C1 on the right side, the X axis is the first axis, the Y axis is the second axis, and in the second corner portion on the left side, the Y axis is the first axis and the X axis is the first axis. There are two axes. The second axis movement start timing is, for example, the second axis movement start timing coincides with the first axis movement start timing, or the second axis movement start timing is slightly different from the first axis movement start timing. It is set in the ROM 37 so as to be delayed. In short, at this stage, it is sufficient that the operation start timing of the second axis does not precede the operation start timing of the first axis. 4 shows an example of the corner portion C1 on the right side of FIG. 3 because the X axis is the first axis and the Y axis is the second axis.

  In S3, as shown in FIG. 8A, a plurality of tangent lines L1 are calculated at predetermined equal interval angles θ with respect to the reference arc E1, and intersection coordinates F as intersections of the tangent lines L1 are calculated. Calculated. Thus, since the tangent line L1 is equiangular, each distance between each intersection coordinate F and the reference | standard circular arc E1 can be made equal. In FIG. 8A, there are four tangent lines L1 including the X axis as the first axis and the Y axis as the second axis. Therefore, the intersection coordinates F are equally spaced at three locations. Is set. The predetermined angle θ is set in advance by manual input or the like. Accordingly, the number of tangents L1 and the number of intersection coordinates F are set in advance.

  In S4, it is assumed that the tool post 26 has moved along the approximate arc locus E2 created by the overlap movement start timing, as shown in FIGS. 8B and 9A. A first time t1 and a second time t2 at which the table 26 reaches a Y-axis direction line L3 as a second axis direction line passing through the intersection coordinate F and an X-axis direction line L2 as a first axis direction line are calculated. .

  Next, in S5, time t1 and time t2 are compared. If t1 = t2, the approximate arc locus E2 passes on the intersection point coordinates F. If t1 <t2, as shown by the solid line in FIG. 8B, the approximate arc locus E2 is located outside the reference arc E1 and outside the reference arc E1 via the intersection coordinates F. If t1> t2, the approximate arc locus E2 is located on the side of the reference arc E1 with respect to the intersection coordinates F, as indicated by a two-dot chain line in FIG. Therefore, if t1 ≦ t2 is satisfied, the approximate arc locus E2 does not enter the inside of the reference arc E1, but if t1> t2, as shown by a two-dot chain line in FIG. There is a possibility that the base 26 moves inside the reference arc E1, and the tools 27A to 27C may interfere with the workpiece W. That is, since the intersection point coordinate F and the reference arc E1 are close to each other, if t1> t2, the approximate arc locus E2 is near the reference point arc near the intersection point coordinate F (the first axis direction extension position of the intersection point coordinate F). There is a high possibility of getting inside. Further, even if the approximate arc locus E2 is outside the reference arc E1 in the vicinity of the intersection coordinate F, there is a possibility that the approximate arc locus E2 enters the inside of the reference arc E1 until the next intersection coordinate F. This is because, when the movement locus between the intersections is almost linear, if the intersection locus F is inside at one intersection coordinate F, the approximate arc locus E2 between the previous and next intersection coordinates F is inside the reference arc E1. This is because there is a high possibility that it has entered. Note that, as in the operation of the present embodiment, the first axis starts moving ahead of or simultaneously with the second axis, the two axes move overlappingly, and then the first axis moves ahead of the second axis. Alternatively, under the condition of stopping at the same time, the movement trajectory is usually a straight line or an arc-shaped trajectory that bulges outward, and does not become a trajectory that bulges inward. For this reason, if the movement trajectory exists outside at all the intersection coordinates F, it does not enter the inside of the reference arc E1 in all the movement ranges.

Therefore, when t1> t2, in S6, as shown in FIG. 9B, the operation start timing in the second axis direction is delayed so that t1 = t2.
Then, the data of the overlap movement start timing K representing t1 = t2 or t1 <t2 is stored in the temporary storage area of the RAM 38.

When t1 = t2 or t1 <t2 is satisfied, the process proceeds to S7.
In S7, it is determined whether or not the processing of S3 to S6 has been completed for all the intersection coordinates F. If completed, the program proceeds to S8, and if not completed, the process returns to S3.

  In S8, for example, it is determined whether or not the processing of S2 to S7 has been completed for all the corner portions C1 and C2 of the route shown in FIG. 3, and if completed, that is, all corners overlap. If the movement start timing K has been set, the program proceeds to S9. If not completed, the process returns to S2, and the process proceeds to the overlap movement start timing K for the next corner.

  In this way, the overlap movement start timing K representing the route along which the tools 27A to 27C move outside the reference arc E1, in other words, the approximate arc locus E2 that does not interfere with the workpiece W, is calculated. In S9, the overlap movement is calculated. The data of the start timing K is transferred from the temporary storage area of the RAM 38 to the working area and stored.

  Therefore, after that, during the tool switching operation, the tool post 26 is moved rapidly while drawing the approximate arc locus E2 outside the reference arc E1, and the tools 27A to 27C and the outer peripheral surface of the workpiece W interfere with each other. Can be prevented. Therefore, the switching of the tools 27A to 27C can be performed in a short time, and the operating efficiency of the machine tool can be improved.

  As shown in FIG. 8D, since the intersection coordinate F approaches the reference arc E1 as the number of tangents L1 set at equiangular intervals increases, the approximate arc locus E2 approaches the reference arc E1. It becomes possible. 8A and 8B show an example in which the value of the equally-spaced angle θ is set to 30 degrees to simplify the description. However, since the angle is actually set to about 1 to 18 degrees, the intersection coordinate F is It exists in the position considerably close to the reference arc E1. Therefore, in this case, the path of the approximate arc locus E2 can be shortened, and the tool switching can be further shortened.

In this embodiment, the following effects can be obtained.
(1) The tool post 26 is moved while drawing an approximate arc locus E2 based on the reference arc E1 by overlapping movement by rapid feed in the X-axis direction and the Y-axis direction at the time of tool switching. For this reason, as compared with the case of the conventional tool switching method shown in FIGS. 16 to 18, the time t ₀ required for the tool switching can be shortened as apparent from the two-dot chain line in FIG. 18. Therefore, the productivity of the machine tool can be improved.

  (2) Since the tools 27A to 27C move outside the reference arc E1 separated from the workpiece W by a predetermined distance, interference between the tools 27A to 27C and the workpiece W can be prevented before the tools 27A to 27C are selectively moved.

(3) Since it is only necessary to set the overlap movement start timing K of the tool post 26, the burden on the memory can be reduced.
(4) The tool post 26 is moved while drawing the approximate arc locus E2 in the area defined by the X axis and the Y axis in the corner portions C1 and C2, and does not go out of the area. 26 and the movement paths of the tools 27A to 27C can be shortened, and productivity can be improved by shortening the movement time.

  (5) By setting the overlap movement start timing K of the tool rest 26, it is calculated whether or not the approximate arc locus E2 of the tool rest 26 passes inside the intersection point coordinate F located outside the reference arc E1. The When the approximate arc locus E2 is inside the intersection coordinate F, the overlap movement start timing K is delayed so that the approximate arc locus E2 is outside the intersection point. Accordingly, the overlap movement start timing K is appropriately set regardless of the fast-forward speed, the acceleration / deceleration speed, or the like. For this reason, even devices with different fast-forwarding speeds and acceleration / deceleration speeds can be flexibly accommodated.

(Second Embodiment)
Next, a second embodiment of the present invention will be described based on FIGS. 1 to 7 and FIGS.

  In the second embodiment, as shown in FIGS. 4 and 7, the overlap movement start timing for forming the approximate arc locus E2 that does not interfere with the workpiece W is not set by calculation, but in FIG. Based on the program shown, it is set according to the tables shown in FIGS. These tables are data tables of overlap start timings calculated in advance from the relationship between the amount of movement of the tool post 26 in the first axis direction and the radius of the reference arc, and correspond to the corner portions C1 and C2, respectively. Is set to a predetermined area. 11 sets the overlap movement start timing in the first corner C1 shown in FIGS. 3 and 5A and 5B, and FIG. 12 shows FIGS. 3 and 5C and FIG. 5D. The overlap movement start timing K in the second corner portion C2 shown in FIG.

  Then, during the tool selection operation, the CPU 36 first calculates the reference arc E1 in S101 of FIG. 10 as in the first embodiment. Next, in S102, from the data table of the RAM 38 shown in FIG. 11, the amount of movement of the tool post 26 in the first corner portion C1 in the first axis direction, that is, the amount of movement in the X-axis direction, the radius of the reference arc E1, and The overlap start timing is extracted from the relationship and stored in the working area of the RAM 38. For example, when the movement amount of the tool post 26 in the X-axis direction is 10 mm and the radius of the reference arc is 6 mm, the overlap movement start timing 4.1 mm is obtained from the data table shown in FIG. Then, in S103, the overlap movement in the Y-axis direction is started from the position where the movement amount in the X-axis direction is 4.1 mm, and the tool post 26 is located outside the reference arc E1 at the first corner C1 with the workpiece W. It moves while drawing the approximate arc locus E2 without interference.

  In the second corner portion C2, following the calculation of the reference arc E1 in S101, the amount of movement of the tool post 26 in the Y-axis direction, which is the first axis, from the data table of the RAM 38 shown in FIG. And the overlap movement start timing are extracted from the radius of the reference arc E1 and stored in the working area of the RAM 38. For example, when the movement amount in the Y-axis direction is 40 mm and the radius of the reference arc E1 is 6 mm, 34.1 mm that is the position of the overlap movement start timing K is obtained from the table shown in FIG. Then, in S103, the overlap movement in the X-axis direction at the second corner portion C2 is started when the movement amount in the Y-axis direction is 34.1 mm, and the tool post 26 moves outside the reference arc E1 to the approximate arc locus. Moved while drawing E2.

Therefore, the second embodiment has the following effects.
(6) When setting the overlap movement start timing, the overlap movement start timing data is extracted from the table, so that the movement start timing can be set quickly in a short time.

(Third embodiment)
Next, a third embodiment of the present invention will be described based on FIGS. 13 to 15 with a focus on differences from the second embodiment.

  In the third embodiment, as shown in FIG. 13A, an allowable arc E3 and an allowable line E4 made of a straight line are formed between the reference arc E1 and the outer peripheral surface of the workpiece W in a region not in contact with the workpiece W. A table is created by virtual setting. The tolerance line E4 continues to the end of the tolerance arc E3. That is, in the third embodiment, at least both ends of the approximate arc locus E2 of the tool post 26 are allowed to be positioned between the allowable arc E3 and the allowable line E4 and the reference arc E1. The allowable arc E3 and the allowable line E4 are set in consideration of the gap C shown in FIG. 5. For example, 20% of the gap C from the reference arc E1 side to the inside of the first axis, the second axis, and the reference arc E1. It is set to a position of about. The data of the allowable arc E3 and the allowable line E4 are provided in advance in the ROM 37 or manually input from the input unit 39 by the user.

For this reason, as is apparent from FIGS. 14 and 15, the overlap movement start timing K is advanced in the table data.
For example, in the same manner as described above, in the first corner portion C1, when the movement amount of the tool post 26 in the X-axis direction is 10 mm and the radius of the reference arc is 6 mm, the overlap movement is obtained from the data table shown in FIG. As the start timing K, 3.8 mm is obtained. In S103, the overlap movement of the Y axis is started when the movement amount in the X axis direction is 3.8 mm, and the tool post 26 is moved while drawing the approximate arc locus E2 outside the reference arc.

  Further, in the second corner portion, when the movement amount in the Y-axis direction is 40 mm and the radius of the reference arc E1 is 6 mm, 29.6 mm is obtained as the overlap movement start timing K from the table shown in FIG. . In S103, the overlap movement of the X axis is started when the movement amount in the Y axis direction is 29.6 mm.

  In this embodiment, it is also possible to adopt only the tolerance line E4 without setting the tolerance arc E3. In this case, as shown in FIG. 13B, the allowable line E4 is extended to the position of the reference arc E1. Therefore, a table is created by setting an area that is virtually not in contact with the workpiece W by the reference arc E1 and the allowable line E4.

Therefore, the third embodiment has the following effects.
(7) Since the tool post 26 can be moved inside the reference arc E1, it is possible to shorten the 26th moving path of the tool and shorten the time required for tool switching.

(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
In the above-described embodiment, the present invention is embodied in the movement control of the tool post 26 in the tool switching operation of the machine tool. However, for example, conveyance of a conveyance robot or the like that grips a workpiece or the like and conveys it from one position to another position. It may be embodied in other devices of the device.

  In the embodiment, the overlap movement start timing is set based on the position data of the tool post 26 on the X axis and the Y axis, but the overlap movement start timing is set based on time data from the start of movement of the tool rest 26. To do.

In the embodiment, the first axis and the second axis are orthogonal to each other, but the present invention is embodied in a configuration in which both axes are obliquely crossed.
In the above-described embodiment, the present invention is embodied in the switching of the tool 27 made of a cutting tool, but is embodied in the switching of another tool such as a rotary tool.

The principal part perspective view which shows the machine tool provided with the movement control apparatus of one Embodiment. The block diagram which shows the circuit structure of the movement control apparatus of FIG. The diagram which shows the movement path | route of a tool post. The diagram which shows the relationship between an overlap movement start timing and an approximate arc locus. (A)-(d) is a partial front view which shows in order the switching movement operation | movement of the tool in the machine tool of FIG. The flowchart which shows the setting program of the overlap movement start timing in 1st Embodiment. The diagram which shows the relationship between a reference | standard circular arc and an approximate circular arc locus. (A)-(d) is a diagram which shows the relationship between the reference | standard arc and approximate arc in the setting of overlap movement start timing. (A) and (b) are the diagrams which show the relationship between 1st time and 2nd time in the setting of overlap movement start timing. The flowchart which shows the setting program of the overlap movement start timing in 2nd Embodiment. The matrix which shows the setting table of the overlap movement start timing in a 1st corner part. The matrix which shows the setting table of the overlap movement start timing in a 2nd corner part. (A) is a diagram showing the relationship between the reference arc, approximate arc trajectory and allowable arc in the third embodiment, and (b) is the relationship between the reference arc, approximate arc trajectory, allowable arc and allowable line in the third embodiment. FIG. The matrix which shows the setting table of the overlap movement start timing of the 1st corner part in 3rd Embodiment. The matrix which shows the setting table of the overlap movement start timing of the 2nd corner part in 3rd Embodiment. (A)-(d) is a partial front view which shows in order the selective movement operation | movement of the tool in the conventional machine tool. The diagram which shows the movement path | route of the tool in FIG. The graph which shows the speed change at the time of the movement of the tool of FIG.

Explanation of symbols

  26 ... Tool post, 27A to 27C ... Tool, 35 ... Control device, 36 ... CPU, 37 ... ROM, 38 ... RAM, 48 ... Tool feed driving device, F ... Intersection coordinates as intersection, L1 ... Tangent, W ... Workpiece , E1 ... reference arc, E3 ... allowance arc, E4 ... allowance line, K ... overlap movement start timing, t1 ... first time, t2 ... second time.

Claims (4)

By moving the moving body on the first axis and on the second axis intersecting the first axis by fast-forwarding, and overlapping the fast-forwarding movements in both axial directions, the moving body moves around the predetermined area. Drive means adapted to move around,
Reference arc setting means for setting a reference arc inscribed in the first axis and the second axis;
Upon transition from the first axis of the moving body on the second shaft, and timing setting means for setting the overlap movement start timing of the rapid traverse of the moving object based on the reference arc,
Control means for controlling the operation of the driving means to move the moving body at the timing set by the timing setting means ;
First calculation means for calculating a plurality of tangents to the reference arc and intersections of adjacent tangents;
Calculate the second time and the first time from the start of the movement of the moving body until reaching the first axis direction line parallel to the first axis and the second axis direction line parallel to the second axis passing through the intersection. and a second calculating means for,
When the second time is shorter than the first time, the timing setting means delays the overlap movement start timing of the moving body so that at least both times are equal to each other. . The movement control apparatus for a moving body according to claim 1 , wherein the plurality of tangent lines are set at equiangular intervals. By moving the moving body on the first axis and on the second axis intersecting with the first axis by fast-forwarding, and overlapping the fast-forwarding movements in both axial directions, the moving body is moved around the predetermined area. Move around,
Setting a reference arc inscribed in the first axis and the second axis;
Upon transition from the first axis of the moving body on the second shaft, and set the overlap movement start timing of the rapid traverse of the moving object based on the reference arc,
Calculating a plurality of tangents to the reference arc and intersections between adjacent tangents;
Calculate the second time and the first time from the start of the movement of the moving body until reaching the first axis direction line parallel to the first axis and the second axis direction line parallel to the second axis passing through the intersection. And
When the second time is shorter than the first time, the overlap movement start timing of the moving body is delayed so that at least both times are equal . A turret with a plurality of tools arranged in parallel;
By causing relative movement by rapid feed between the tool post and the workpiece in the direction of the first axis and in the direction of the second axis intersecting the first axis, and by overlapping the rapid feed in both axial directions Drive means adapted to move the tool post relatively around the work,
In a machine tool in which the switching of the tool is performed by the operation of the driving means,
A machine tool movement control device comprising the configuration according to claim 1 or 2 , wherein the moving body in the configuration is the tool post.

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