MACHINE TOOL

Abstract

Machine tool (1) comprising: a spindle (41); a tool changer (7) which attaches or removes one of the tools (T, T1, T2, T3, T4) from the spindle (41); a spindle movement device (5) which moves the spindle (41) to one of the tool change coordinates (TC1, TC2, TC3, TC4) when one of the tools (T, T1, T2, T3, T4) is to be attached to or removed from the tool changer (7); and a tool change control which controls the spindle movement device (5) such that it moves the spindle (41) to one of the tool change coordinates among the several preset tool change coordinates (TC1, TC2, TC3, TC4) assigned to the tools (T, T1, T2, T3, T4) according to a first tool change coordinate assigned to a target tool to be attached to the spindle (41) and a second tool change coordinate assigned to a target tool to be removed from the spindle (41).where the first tool change coordinate and the second tool change coordinate are located further away from a machining point when one of the tools (T, T1, T2, T3, T4) is to be attached or removed by the tool changer (7), wherein the tool changer (7) is designed to move one of the tools (T, T1, T2, T3, T4) to one of the tool change coordinates (TC1, TC2, TC3, TC4) when one of the tools (T, T1, T2, T3, T4) is to be attached or removed, and the tool change coordinates (TC1, TC2, TC3, TC4) serve as coordinates to which the tool changer (7) moves the target tool for attaching or the target tool for removing into a clamping position or a release position of the spindle (41), at which the spindle (41) clamps the target tool for attaching or removing the ... removal target tool releases; wherein the tool change control is designed to control the spindle movement device (5) in such a way,that the spindle (41), after the removal target tool has been released in the clamping or release position, is raised to a clamping readiness position which is a value (Σ) further away from the machining point than the clamping or release position, and that the spindle (41), before the attachment target tool is clamped in the clamping or release position, is lowered from the clamping readiness position by the value (Σ).

Description

BACKGROUND OF THE INVENTION Area of ​​the invention

[0001] The present invention relates to a machine tool. Related technology

[0002] Traditionally, a machine tool that machines a workpiece with a tool attached to a spindle is known to include a tool changer that holds several types of tools and has the function of being suitable for automatically supporting several types of machining by exchanging one of the tools for another when a type of machining of the workpiece is to be changed (see, for example, the unexamined Japanese patent application Publication No. H02-53542 and the like).

[0003] Patent specification 1: unexamined Japanese patent application, publication no. H02-53542 SUMMARY OF THE INVENTION

[0004] When tools are to be exchanged, a spindle moves in its axial direction (this direction is also an axial direction of the tool) away from a workpiece to a tool change coordinate, where the tools are exchanged by a tool changer. After the spindle has moved to the tool change coordinate, different types of operations take place to clamp and unclamp the tool and to remove the tool. More precisely, the tool change process performed by the tool changer proceeds as described below. - The spindle moves to a tool change coordinate where tools are to be exchanged. - The tool changer grips a tool attached to the spindle. - The spindle releases the tool. - The spindle and the tool (the tool changer) move relative to each other to remove the tool from the spindle. - The tool changer moves a tool picked up for subsequent use to a position on the spindle. - The spindle and the next tool to be used (the tool changer) move relative to each other to insert the tool into the spindle. - The spindle clamps the next tool to be used. - The tool changer releases the grasped tool that will be used next.

[0005] At the tool change coordinate, to which the spindle moves during tool changes via the tool changer, a clearance between the spindle and a workpiece is required to remove a tool from the spindle and clamp a new tool onto the spindle. Therefore, the tool change coordinate is set to a coordinate at which the largest such tool (in terms of axial length) among several tool types used by the machine tool can be exchanged. This tool change coordinate is currently determined according to a machine tool configuration and is not changed for each tool.Therefore, with a conventional machine tool, depending on the type of tool being removed and the type being fitted, additional unnecessary time may be required to move the spindle from a machining end coordinate to a tool change coordinate and to move the spindle from the tool change coordinate to a machining start coordinate after the tool change. Thus, there is a need for a machine tool that is suitable for shortening the cycle time of a machining cycle and reducing unnecessary downtime during tool changes.

[0006] According to one aspect of the present disclosure, a machine tool comprises a spindle, a tool changer that attaches or removes one of the tools from the spindle, a spindle motion device that moves the spindle to one of the tool change coordinates when one of the tools is to be attached to or removed from the tool changer;and a tool change control that controls the spindle motion device in such a way that it moves the spindle, according to a first tool change coordinate assigned to a target tool to be attached to the spindle and a second tool change coordinate assigned to a target tool to be removed from the spindle, to one of the tool change coordinates among the several preset tool change coordinates assigned to the tools, which is the one under the first and second tool change coordinates that is further away from a machining point when one of the tools is to be attached to or removed from the tool changer.

[0007] According to this aspect, it is possible to provide a machine tool that is suitable for shortening the cycle time of a machining cycle in order to reduce unnecessary downtime during tool changes. List of characters Fig. Figure 1 is a side view showing a machine tool according to one aspect of the present disclosure; Fig. Figure 2 is a top view showing a tool-changing arm of a tool changer according to the aspect of the present disclosure; Fig. Figure 3 is a top view showing the operation of the tool changer arm according to the aspect of the present disclosure; Fig. Figure 4 is a functional block diagram showing a configuration relating to tool changes on the machine tool according to the aspect of the present disclosure; Fig. 5 is a view showing a reference table stored in a storage unit according to the aspect of the present disclosure; Fig. Figure 6 is a flowchart showing a tool change operation on the machine tool according to the aspect of the present disclosure; Fig. Figure 7 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure; Fig. Figure 8 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure; Fig. Figure 9 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure; Fig. Figure 10 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure; Fig. Figure 11 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure; Fig. Figure 12 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure; Fig. Figure 13 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure; Fig. Figure 14 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure; Fig. Figure 15 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure; Fig. Figure 16 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure; Fig. Figure 17 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure; and Fig. Figure 18 is a view showing the tool change process on the machine tool according to the aspect of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0008] One aspect of the present revelation will now be described in detail with reference to the accompanying drawings. As in Fig. Shown in 1, it comprises a machine tool 1 a base section 2, which is installed on a floor surface, a stand section 3, which is extended from the base section 2 (according to Fig. 1 in one direction Z1) rises upwards, a spindle unit 4 which is located on the side of a front face (according to Fig. 1 on the left side) of the stand section 3, a spindle movement device is arranged 5 , which is provided between the spindle unit 4 and the column section 3 and which moves the spindle unit 4 along a Z-axis in a direction upwards or downwards (according to Fig. 1 in the direction Z1 or in a direction Z2), a table unit 6 which is provided on the base section 2 and holds a workpiece W on its upper side, and a tool changer 7, which is located next to the spindle unit 4.

[0009] The spindle unit 4 includes a spindle at its front end. 41 , at which one of the tools T attached or from which it can be removed, and a spindle motor 42 which drives the spindle 41 The spindle motor 42 is driven in a rotating manner. When the spindle motor 42 is driven in a rotating manner, the spindle rotates. 41 for machining the workpiece W arranged below, one of the tools T , which is attached to the front end.

[0010] The spindle 41 It includes inside a (not shown) pull rod used to clamp or release one of the tools T is used. Inside the spindle 41 The pull rod is used to clamp or release one of the tools. T at the front end of the spindle 41advanced or retracted by a (not shown) feed-retraction mechanism. If one of the tools... T clamped, it becomes one of the tools T on the spindle 41 attached. Once it is detached, one of the tools will be used. T in relation to the spindle 41 moved in a separation direction and from the spindle 41 The feed-retraction mechanism, which advances and retracts the drawbar, is controlled by a tool change control described later. 100 controlled.

[0011] The spindle motion device 5The assembly comprises a ball screw (not shown) arranged in one direction of extension of the stator section 3, a movable element 51 that moves together with the ball screw, and a Z-axis motor 52 that rotates the ball screw. The spindle unit 4 is attached to the movable element 51. By rotating the Z-axis motor 52, the spindle motion device rotates. 5 the ball screw such that it moves the spindle unit 4 via the movable element 51, which moves together with the ball screw, along the Z-axis in the direction upwards or downwards (according to Fig. 1 in the direction Z1 or the direction Z2).

[0012] The tool changer 7 includes a tool magazine 71, which holds several of the tools T holds a tool change arm 72, which is for simultaneously gripping two of the tools T and Tis suitable, and a tool change arm motion device 73 which moves the tool change arm 72.

[0013] The tool magazine 71 is designed so that, for example, it can be raised and lowered along the Z-axis in the upward and downward directions by means of a (not shown) lifting and lowering mechanism (according to Fig. 1 in the direction Z1 and the direction Z2) and is designed to rotate about the Z-axis by means of a (not shown) rotary mechanism. During tool changes, the tool magazine 71 is lowered or raised and rotated to ensure that a tool held straight is inserted. T among the several tools T is moved to a position where one tool T can be grasped by the tool-changing arm 72. The tool magazine 71 can be a turret head that holds the several tools. T holds.

[0014] The tool change arm 72 comprises, as shown in Fig. Figure 2 shows two fixed claw sections 721 and 721, each extending in opposite directions, and two movable claw sections 722 and 722, each arranged such that they face the fixed claw sections 721 and 721. Recessed sections 723 and 723 are formed between the fixed claw sections 721 and 721 and the movable claw sections 722 and 722, each designed to receive the tools. T are suitable. The movable claw sections 722 and 722 are each designed to be advanced towards or retracted from the fixed claw sections 721 and 721. When the tools T and T Since the tools are each inserted into the recessed sections 723 and 723, the tool change arm 72 therefore holds the tools. T and Tin the recessed sections 723 and 723 between the fixed claw sections 721 and 721 and the movable claw sections 722 and 722.

[0015] The tool change arm motion device 73 comprises an axis section 74 which extends along the Z-axis in the downward direction (according to Fig. The axis section 74 extends along the Z-axis (1 in the direction Z2), comprising an arm rotary motor 75 and an arm lift-lower motor 76. The rotary drive of the arm rotary motor 75 rotates the axis section 74 about the Z-axis. Therefore, the tool change arm 72, attached to a front end of the axis section 74, is rotated about the Z-axis around the axis section 74. It should be noted that the rotary drive of the arm lift-lower motor 76 extends or retracts the axis section 74 along the Z-axis. Therefore, the tool change arm 72, attached to the front end of the axis section 74, is moved upwards or downwards along the Z-axis (according to the Z-axis). Fig. 1 in the direction Z1 or the direction Z2). The arm rotary motor 75 and the arm lifting and lowering motor 76 form the tool-changing arm motion device.

[0016] The tool change arm 72 is in Fig. 3 shown in a non-engaging state in which none of the tools T and T is held. If the tool-changing arm 72 is rotated clockwise around the axis section 74 from the non-engaging state by the rotating drive of the arm rotation motor 75, the tools are T and T each included in the recessed sections 723 and 723, as in the Fig. 1 and Fig. 2 shown. Therefore, the tool change arm 72 is in a gripping state in which the tools T and TThe tools are held between the fixed claw sections 721 and 722 and the movable claw sections 722 and 722. In the gripping position, the tool-changing arm 72 holds one of the tools in one of the recessed sections 723. T , which was removed from tool magazine 71 (one of the tools T (also referred to as the attachment target tool), and in the other of the recessed sections 723 another of the tools T , that on the spindle 41 is appropriate (the other of the tools T (also referred to as a acceptance target tool).

[0017] Fig. Figure 4 is a functional block diagram that shows a configuration of the machine tool relating to tool changes. 1 shows. As in Fig. As shown in section 4, the machine tool includes 1in its (not shown) control device or control console, the tool change control is coupled to the Z-axis motor 52, the arm rotary motor 75 and the arm lifting and lowering motor 76, each capable of being controlled. 100 and one readable with the tool change control 100 coupled storage unit 101. The tool change control 100 can be used from a machine tool specifically designed for tool changing operations. 1 provided control or formed by a control system that controls the entire operation of the machine tool 1 controls.

[0018] Storage unit 101 contains a Fig. Reference table 102, shown in section 5, is stored in reference table 102. Tool change coordinates are stored in reference table 102. TC1 , TC2 , TC3 , TC4 , etc. specified, at which the tools T each on the spindle 41 to be attached or removed from it. The tool change coordinates. TC1 , TC2 , TC3 , TC4 , etc. are one-to-one equivalents of several tools. T1 , T2 , T3 , T4 , etc. assigned, which is attached to the spindle 41 attached tool T and the tools held by tool magazine 71 T include the tool change coordinates. TC1 , TC2 , TC3 , TC4 , etc. correspond to the sizes of the tools. T1 , T2 , T3 , T4 , etc. (their lengths in the axial direction).

[0019] The tool change coordinates specified in reference table 102 TC1 , TC2 , TC3 , TC4 , etc. represent coordinates on the Z-axis to which the tool changer is attached. 7 during tool changes of each of the tools held by the tool change arm 72 T1 , T2 , T3 , T4 , etc. in relation to the spindle 41moved into a clamping position or a release position. In other words, the tool change coordinates represent TC1 , TC2 , TC3 , TC4 , etc. also coordinates at which a front end 41a of the spindle is located during tool change 41 each of the tools T1 , T2 , T3 , T4 , etc. clamps or releases. Preferably, the tool change coordinates are TC1 , TC2 , TC3 , TC4 , etc. each set to positions on the Z-axis where, during tool changes, a front end of each of the tools T1 , T2 , T3 , T4 , etc. does not come into contact with the workpiece W, but gets as close as possible to the workpiece W.

[0020] Next, with reference to the in Fig. The flowchart shown in section 6 and the one in the Fig. 7 to Fig. The 18 views shown depict the tool change process, a specific tool change process on the machine tool. 1 described. According to Fig. 7 is the tool T1 with the smallest size among the several from the machine tool 1 tools to be used T on the spindle 41 attached. First, a case is described in which the tool T1 against the tool T2 with the largest size among the several from the machine tool 1 tools to be used T is to be substituted in.

[0021] After completing the machining of workpiece W with the tool T1 and when issuing an instruction to change the tool T1 against the tool T2 The tool change control 100 in the reference table 102 stored in storage unit 101, to the tool change coordinate TC1 for the tool T1 , that is on the spindle 41 The attached acceptance target tool is, and the tool change coordinate TC2 for the tool T2 Reference, which is a replacement for the tool T1 on the spindle 41 The target tool to be attached is (S1). In this case, the tool change coordinate is represented. TC1 a second tool change coordinate, whereas the tool change coordinate TC2 represents a first tool change coordinate.

[0022] After referencing reference table 102, the tool change control compares 100 the tool change coordinate TC1 and the tool change coordinate TC2 together and then controls according to the tool change coordinate TC1 and the tool change coordinate TC2 the Z-axis motor 52 of the spindle motion device 5so that spindle unit 4 is raised. Therefore, the tool change control initiates this. 100 a movement of the front end 41a of the spindle 41 and the one on the spindle 41 attached tool T1 to each tool change coordinate (S2) that is further away from a machining point on the workpiece W (a surface of the workpiece W). In a case where the tool T1 against the tool T2 The tool indicates that it is to be replaced. T2 a larger size than the tool T1 Therefore, the tool change coordinate represents TC2 a coordinate further away from the machining point than the tool change coordinate TC1 Therefore, the tool change control system initiates 100 In step S2, a movement of the front end 41a of the spindle 41 and the one on the spindle 41 attached tool T1to the tool change coordinate TC2 , as in Fig. 7 shown. The tool change coordinate TC2 is set to a position that is a height H1 above the workpiece W, in which the tool T2 even if the tool does not come into contact with the workpiece W T2 on the spindle 41 is attached.

[0023] A position of the tool held by the tool magazine 71 T2 At this point, the Z-axis is located at the tool change coordinate. TC2 , when the tool magazine 71 is raised. In Fig. Figure 7 omits the illustration of the tool magazine 71, and only the tool is shown. T2 shown. The tool change arm 72 is in the non-engaging state (see Fig. 3) and is located at a position on the Z-axis where the two are each at the tool change coordinate TC2 arranged tools T1 and T2 can be seized.

[0024] After the front end 41a of the spindle 41 and the tool T1 to the tool change coordinate TC2 The tool change control system controls the movements. 100 The arm rotation motor 75 rotates the tool change arm 72, which is in the non-gripping state, clockwise by an angle of 90° to bring the tool change arm 72 into the gripping state. Therefore, the tool change arm 72 grips the tool. T1 (S3). At this point, the tool is also T2 likewise at a position on the Z-axis, i.e. at the tool change coordinate TC2 arranged. Therefore, the tool change arm 72 is arranged as shown in Fig. 8 shown, rotated and simultaneously grasps the tool T1 and the tool T2 After the tool T2The tool was gripped by the tool change arm 72. T2 from the (not shown) tool magazine 71 when the tool magazine 71 is lifted.

[0025] After the tool change arm 72 has removed the tools T1 and T2 has taken action, triggers the tool change control 100 the pull rod in the spindle 41 to move and the tool T1 to release. The tool change control then controls 100 , as in Fig. Figure 9 shows the Z-axis motor 52 raising the spindle unit 4 and then causing a movement of the front end 41a of the spindle. 41 to a clamping readiness position TC2 +α for the next tool to be attached T2 This makes the tool T1 from the spindle 41 removed (S4). The front end 41a of the spindle 41 , which leads to the clamping readiness position TC2 +α for the tool T2 The workpiece W, which was moved, is positioned higher than the height H1 by a value of the letter α.

[0026] The one at the clamping readiness position TC2 +α, at which the front end 41a of the spindle 41 The letter “α” shown represents a value by which the clamping readiness position can be adjusted. TC2 +α in the direction Z1 further than the tool change coordinate TC2 is located away from workpiece W. The value of the letter "α" is set to a value where a tool change coordinate is located at the TC2 arranged acceptance target tool (the tool T1 ) during a rotation of the tool change arm 72 from below the spindle 41 moved away and an attachment targeting tool (the tool) T2 ) under the spindle 41It can be positioned so that the target tool can be as close as possible to the workpiece W. One reason for this is that, to shorten the time between completing the clamping process and resuming machining, the distance by which the spindle can travel can be reduced. 41 to clamp a target tool for attachment. The value of the letter "α" is independent of the type (size) of the tools. T set to a constant value.

[0027] Next, the tool change control system controls 100 The arm rotation motor 75 is rotated such that the tool change arm 72 is rotated only by an angle of 180° · n (where n represents an odd number of 1 or greater). Therefore, the tool change control 100 , as in Fig. 10 shown, the removal of the tool T1 from below the spindle 41 as well as the arrangement of the tool T2under the spindle 41 (S5).

[0028] After arranging the tool T2 under the spindle 41 controls the tool change control 100 The Z-axis motor 52 is moved such that the spindle unit 4 is lowered only by a distance corresponding to the value of the letter "α". This causes the tool change control to 100 , as in Fig. Figure 11 shows a movement of the front end 41a of the spindle. 41 to the tool change coordinate TC2 as well as clamping the tool T2 through the spindle 41 (S6). At this point, the tool T1 held by the tool magazine 71 when the (not shown) tool magazine 71 is lowered. The tool change control then operates. 100to initiate a transition of the tool change arm 72 into the non-engaging state, the arm rotation motor 75 is activated, and then the tool change arm 72 is removed from below the spindle. 41 (S7).

[0029] The above-described workflow will make the tool T2 as a replacement for the tool T1 new on the spindle 41 attached. After attaching the tool T2 on the spindle 41 The machine tool begins 1 again with the machining of the workpiece W with the tool T2 , as in Fig. 12 shown.

[0030] Next, a case will be described in which the spindle 41 attached tool T1 with the smallest size against the tool T3 , whose size is related to that of the tool T1 is identical, among the several from the machine tool 1 tools to be usedT The tool change process is also carried out in this case according to the procedure described in Fig. The flowchart shown in section 6 was executed.

[0031] After completing the machining of workpiece W with the tool T1 and when issuing an instruction to change the tool T1 against the tool T3 The tool change control 100 in the reference table 102 stored in storage unit 101, to the tool change coordinate TC1 for the tool T1 , that is on the spindle 41 The attached acceptance target tool is, and the tool change coordinate TC3 for the tool T3 Reference, which is a replacement for the tool T1 on the spindle 41 The target tool to be attached is (S1). In this case, the tool change coordinate is represented. TC1 the second tool change coordinate, whereas the tool change coordinate TC3 represents the first tool change coordinate.

[0032] After referencing reference table 102, the tool change control compares 100 the tool change coordinate TC1 and the tool change coordinate TC3 together and then controls according to the tool change coordinate TC1 and the tool change coordinate TC3 the Z-axis motor 52 of the spindle motion device 5 so that spindle unit 4 is raised. This triggers the tool change control. 100 a movement of the front end 41a of the spindle 41 and the one on the spindle 41 attached tool T1 to each tool change coordinate (S2) that is further away from a machining point on the workpiece W (the surface of the workpiece W). In a case where the toolT1 against the tool T3 The tool is to be replaced. T1 and the tool T3 identical sizes, and therefore represent the tool change coordinate TC1 and the tool change coordinate TC3 identical coordinates. Therefore, the tool change control initiates 100 In step S2, a movement of the front end 41a of the spindle 41 and the one on the spindle 41 attached tool T1 to the tool change coordinate TC1 (= TC3), as in Fig. 13 shown. The tool change coordinate TC1 (= TC3) is on an upwards by a height H2, in which the tool T1 The position H2 is set away from workpiece W, without coming into contact with it. The height H2 is less than the height H1 described above.

[0033] At this point, the tool held by tool magazine 71T3 at the tool change coordinate TC1 arranged when the tool magazine 71 is lowered. Also in Fig. In Figure 13, the illustration of the tool magazine 71 was omitted, and only the tool is shown. T3 shown. The tool change arm 72 is in the non-engaging state (see Fig. 3) and is located at a position on the Z-axis where the respective tool change coordinate TC1 arranged tools T1 and T3 can be seized.

[0034] After moving the front end 41a of the spindle 41 and the tool T1 to the tool change coordinate TC1 controls the tool change control 100The arm rotation motor 75 is rotated such that the tool change arm 72, which is in the non-gripping state, is rotated clockwise by an angle of 90° to bring the tool change arm 72 into the gripping state. This allows the tool change arm 72 to grip the tools. T1 and T3 , as in Fig. 14 shown (S3). After grasping the tool T3 The tool is moved by the tool change arm 72. T3 from the (not shown) tool magazine 71 when the tool magazine 71 is lifted.

[0035] After grasping the tools T1 and T3 The tool change control is initiated by the tool change arm 72 100 the pull rod in the spindle 41 to move and the tool T1 to release. After that, the tool change control system takes over. 100 according to the tool change coordinate TC3 , which was referred to, as in Fig. Figure 15 shows the Z-axis motor 52 raising the spindle unit 4 and then causing a movement of the front end 41a of the spindle. 41 to a clamping readiness position TC3 +α for the next tool to be attached T3 This makes the tool T1 from the spindle 41 approved (S4).

[0036] Since the size of the tool T3 with the tool T1 The tool change coordinate is identical. TC3 for the tool T3 identical to the tool change coordinate TC1 for the tool T1 , and the clamping readiness position TC3 +α for the tool T3 is equipped with a clamping readiness position TC1 +α for the tool T1 identical. A height H3 of the tool change coordinate TC3 With respect to the workpiece W, the height H2 of the tool change coordinate is identical. TC1 With regard to the workpiece W. Therefore, in step S4, the front end 41a of the spindle is 41 immediately after removing the tool T1 at the clamping readiness position TC3 +α (= TC1 +α) for the next tool to be attached T3 It has stopped and is no longer moving in the Z1 direction. The spindle 41 retains position ( TC1 +α = TC3 +α), at which the tool T1 Once removed, the tool is in a ready state. It should be noted that the position of the tool change arm 72 also does not change in any direction along the Z-axis.

[0037] Next, the tool change control system controls 100The arm rotation motor 75 is rotated such that the tool change arm 72 is rotated only by an angle of 180° · n (where n represents an odd number of 1 or greater). Therefore, the tool change control 100 , as in Fig. 16 shown, a removal of the tool T1 from below the spindle 41 as well as the arrangement of the tool T3 under the spindle 41 (S5).

[0038] After arranging the tool T3 under the spindle 41 controls the tool change control 100 The Z-axis motor 52 is controlled such that the spindle unit 4 is lowered only by a distance corresponding to the value of the letter "α". Therefore, the tool change control initiates 100 , as in Fig. Figure 17 shows a movement of the front end 41a of the spindle. 41 to the tool change coordinate TC3 as well as clamping the tool T3 through the spindle 41(S6). At this point, the tool T1 held by the (not shown) tool magazine 71. The tool change control then operates. 100 to initiate a change of the tool change arm 72 into the non-engaging state, the arm rotation motor 75 is activated, and then the tool change arm 72 is removed from below the spindle. 41 (S7).

[0039] The above-described workflow will make the tool T3 as a replacement for the tool T1 new on the spindle 41 attached. After attaching the tool T3 on the spindle 41 The machine tool begins 1 again with the machining of workpiece W with the tool T3 , as in Fig. 18 shown.

[0040] As described above, the tool change control system controls 100 the machine tool 1 the spindle motion device 5(the Z-axis motor 52) so that it engages the spindle 41 corresponding to the one on the spindle 41 the first tool change coordinate assigned to the target tool to be attached and the one from the spindle 41 The second tool change coordinate assigned to the removal target tool is moved to one of the tool change coordinates, which is the one under the first tool change coordinate and the second tool change coordinate that is further away from a machining point, if one of the tools T to be attached or removed. Therefore, as described above, the height H2 (= H3) to which the tools are attached can be adjusted. T1 and T3 and the spindle 41 when changing the tool T1 with the smallest size against the tool T3 to be moved, which also has the smallest size, compared to the height H1 to which the tools are moved.T1 and T2 and the spindle 41 when changing the tool T1 with the smallest size against the tool T2 with the largest size. This means that a size by which the tools T and the spindle 41 They are moved during tool changes, according to the size of the tools. T (their lengths in the axial direction) becomes minimal. Therefore, the tool change can be performed more efficiently. T1 with the smallest size against the tool T3 , which also has the smallest size, required tool change time compared to that for changing the tool T1 with the smallest size against the tool T2 The largest size tool change time is reduced, thus shortening the tool change time. Therefore, this applies to the machine tool. 1It is possible to shorten the cycle time of a machining cycle by reducing unnecessary downtime during tool changes.

[0041] The machine tool described above 1 is configured to cause one of the tools to T comes to a standstill, but the spindle unit 4 is moved in the upward or downward direction when one of the tools T to be clamped or unclamped. With this configuration, it is not necessary to provide clearance for removing one of the tools when changing tools. T from spindle 41 down between one of the tools T and to ensure the workpiece W, thereby the spindle 41 so that the workpiece W can be as close as possible during tool changes. Therefore, it is possible to determine the required distance by which the spindle must travel. 41to minimize the time it takes for the tool to move during the period from the completion of the tool change until machining resumes. One of the tools T and the spindle unit 4 (the spindle 41 However, they can at least move relative to each other. Thus, the machine tool 1 be configured to cause spindle unit 4 to stop, which is one of the tools T however, it is moved in the upward or downward direction when one of the tools T to be clamped or released.

[0042] It should be noted that the machine tool described above 1 is configured to cause the tool change arm 72 to grasp an application target tool or a removal target. In a case where the tool magazine 71, which holds the multiple tools Theld, formed by a turret head, the machine tool 1 however, they can be configured to be an attachment target tool or a removal target tool without the use of the tool change arm 72 between the turret head and the spindle. 41 attaches or removes directly.

[0043] To attach or remove one of the tools T on or from the spindle 41 A robot can be used instead of the tool change arm 72. It should be noted that the axial direction of the spindle 41 and the tools T at the machine tool 1 is not limited to an arrangement in the directions upwards and downwards, but can be arranged in a lateral direction or in an oblique direction. Reference symbol list 1 machine tool 41 Spindle 5 Spindle motion device 7 tool changers 100 tool change control T, T1, T2, T3, T4 tool TC1, TC2, TC3, TC4 Tool change coordinate QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP H0253542 [0002, 0003]

Claims

[1] Machine tool (1) comprising: a spindle (41); a tool changer (7) which attaches one of the tools (T, T1, T2, T3, T4) to or removes one of the tools (T, T1, T2, T3, T4) from the spindle (41); a spindle movement device (5) that moves the spindle (41) to one of tool change coordinates (TC1, TC2, TC3, TC4) when one of the tools (T, T1, T2, T3, T4) is to be attached to or removed from the tool changer (7); and a tool change control which controls the spindle movement device (5) such that it moves the spindle (41) according to a first tool change coordinate assigned to an attachment target tool to be attached to the spindle (41) and a second tool change coordinate assigned to an removal target tool to be removed from the spindle (41) among the several preset tool change coordinates (TC1, TC2, TC3, TC4) assigned to the tools (T, T1, T2, T3, T4), to one of the tool change coordinates which is the one under the first tool change coordinate and the second tool change coordinate which is further away from a machining point when one of the tools (T, T1, T2, T3, T4) is to be attached to or removed from the tool changer (7). [2] Machine tool (1) according to claim 1, wherein the tool changer (7) is designed to move one of the tools (T, T1, T2, T3, T4) to one of the tool change coordinates (TC1, TC2, TC3, TC4) when one of the tools (T, T1, T2, T3, T4) is to be attached or removed, and the tool change coordinates (TC1, TC2, TC3, TC4) serve as coordinates to which the tool changer (7) moves the attachment target tool or the removal target tool into a clamping position or a release position of the spindle (41). [3] Machine tool (1) according to claim 1 or 2, wherein the tool change coordinates (TC1, TC2, TC3, TC4) serve as coordinates at which the spindle (41) clamps the attachment target tool or releases the removal target tool.

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