Automatic tool changer and machine tool

Abstract

To lock and change a tool by only the movement of a changing arm.SOLUTION: When a changing arm 100 is rotated by 90 degrees in the direction of an arrow F1 to change a tool, a movable plate 220 of a lock control mechanism 200 is rotated and a tip of a lock pin 306 of a tool lock mechanism 300 is pushed into an opening 226 of the exposed movable plate 220 by a spring 304. Then, a link piece 308 extends, a lock arm 310 slides to a tool side, and the tool is fixed by a tip 312. Thereafter, the changing arm 100 is rotated by 180 degrees and the tool is changed. When returning to an unlocked state, the diameter of a ring spring 258 reduced at the time of locking is expanded, so that the movable plate 220 is rotated and the opening 226 is hidden by a fixed plate 210.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an automatic tool changer (ATC) used in machining centers and the like, and to improvements to machine tools that utilize the same. [Background technology]

[0002] Automatic tool changers, which automatically change between different types of tools, are designed to improve productivity by automatically changing multiple tools stored in a tool magazine or tool tray depending on the type of work being performed, and various types are known.

[0003] For example, Patent Document 1 below discloses an automatic tool changer proposed by the present inventor. This device aims to reduce the load on the locking member when a tool is locked and to make the movement speed adjustable. A guide portion is provided on a lifting member that passes through an exchange arm having a tool gripping portion in the arm axial direction. One end of a link that can reciprocate along the longitudinal direction of the exchange arm is connected via a pin that can slide along the guide portion. This reduces the load applied when the tool is locked. In particular, by making the guide portion cam-shaped, the link can move at a non-uniform speed, thereby reducing the impact when the tool is locked. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-13318 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional automatic tool changers, the locking of the tool is performed while the tool is being pulled out from the magazine or spindle, which does not necessarily provide a sufficient locking effect, and there is a possibility that the tool may fall out during tool change. The present invention addresses this issue and aims to provide a method for locking the tool properly during tool change, thereby enabling a smooth tool change operation. [Means for solving the problem]

[0006] The automatic tool changer of the present invention comprises: a, an exchange arm that rotates and moves in the direction of the rotation axis to exchange tools; b, a tool locking mechanism for locking the tool held by the exchange arm; c) a lock control mechanism that controls the tool lock / unlock operation by the tool lock mechanism in accordance with the rotation of the exchange arm; The present invention also provides a machine tool equipped with the above-described automatic tool changer. The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description and accompanying drawings. [Effects of the Invention]

[0007] According to the present invention, locking, extracting, exchanging, unlocking and returning of a tool can be performed simply by the movement of the exchange arm 100, and the series of operations for tool exchange can be carried out smoothly. [Brief explanation of the drawings]

[0008] [Figure 1] 1 shows a plan view of a first embodiment of the automatic tool changer of the present invention. [Figure 2] The figure shows a main cross section taken along line #1-#1 in FIG. 1 and viewed in the direction of the arrow. [Figure 3] The lock control mechanism in the embodiment is shown in exploded form. Figures (A-1) to (A-3) show the fixed plate 210, (B-1) to (B-3) show the movable plate 220, and (C-1) to (C-5) show the structure in which they are stacked. [Figure 4]1A and 1B show the operation of the lock control mechanism in the embodiment as viewed from above, where FIG. 1A shows the state when the tool is unlocked, and FIG. 1B shows the state when the tool is locked. [Figure 5] 1 shows the operation of the lock control mechanism in the embodiment as seen from a main cross section, where (A) shows the state when the tool is unlocked, and (B) shows the state when the tool is locked. [Figure 6] The operation of the tool locking mechanism and lock control mechanism in the embodiment is shown in Fig. 1. (A-1) and (A-2) show the state when the tool is unlocked, and (B-1) and (B-2) show the state when the tool is locked. [Figure 7] 10 shows the state when the tool is locked after rotating 90 degrees in the embodiment. [Figure 8] 4 shows the main plane of a second embodiment of the automatic tool changer of the present invention; [Figure 9] 10 shows a cross section of a main part of a third embodiment of the automatic tool changer of the present invention. [Figure 10] 10 shows a cross section of a main part of a fourth embodiment of the automatic tool changer of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] The best mode for carrying out the present invention will be described in detail below with reference to examples. [Example]

[0010] Fig. 1 shows a plan view of the automatic tool changer of this embodiment. In the figure, the automatic tool changer 10 is configured around an exchange arm 100, which is rotatable and movable up and down around a rotation axis 110. That is, a) The exchange arm 100 rotates 90 degrees in the direction indicated by the arrow F1 from the state shown in the figure. b) In this state, the tools before and after the replacement are respectively gripped at the tip of the replacement arm 100 and locked. c) Next, the exchange arm 100 moves up and down, and the tool it has gripped is pulled out from the magazine or the spindle of the machine tool. d. Next, the exchange arm 100 rotates 180 degrees and the tool is in the exchange position. e. Next, the exchange arm 100 moves up and down, and the exchanged tool is attached to the spindle or magazine. f. Next, the lock is released and the exchange arm 100 rotates 90 degrees, returning to the state shown in FIG. The above operations are all similar to those of known automatic tool changers.

[0011] As shown in the plan view of FIG. 1, the exchange arm 100 includes a center portion 120 provided on the rotating shaft 110, extension portions 130 extending in opposite directions from the center portion 120, and gripping portions 140 provided at the tips of the extension portions 130. The gripping portions 140 have openings 142 facing in opposite directions. The center portion 120 is also provided with a lock control mechanism 200. The lock control mechanism 200 has a function of controlling the locking and unlocking of the tool in the gripping portion 140 in response to the rotation of the exchange arm 100, and is configured to transition to a locked state in response to the rotation of a lock control pin 122 provided on the center portion 120. Details will be described later.

[0012] FIG. 2 shows a cross section of the main parts as viewed in the direction of the arrows along line #1-#1 in FIG. 1. The left side of the figure shows the state before the tool is locked, and the right side shows the state after the tool is locked. In the figure, a lock control mechanism 200, which will be described in detail later, is provided in the center 120 of the exchange arm 100. A tool lock mechanism 300 is also provided between the center 120 and the extension 130 of the exchange arm 100. The tool lock mechanism 300 has an outer tube 302 in which a spring 304 and a lock pin 306 are provided, and the lock pin 306 is biased toward the lock control mechanism 200 by the spring 304. A lock arm 310 is slidably provided within the extension 130 of the exchange arm 100, and its tip 312 protrudes toward the tool side of the gripper 140, thereby locking the tool. A link piece 308 is provided between the lock pin 306 and the lock arm 310, and in response to the up and down movement of the lock pin 306 accompanying the rotation of the exchange arm 100, the link piece 308 is displaced to the left and right sides in the same figure, so that the tool is locked and unlocked by the tip 312 of the lock arm 310.

[0013] Next, the lock control mechanism 200 will be described with reference to Figures 3 to 5. Figure 3 shows the lock control mechanism 200 in an exploded view, with the movable plate 220 shown in Figures (B-1) to (B-3) superimposed on the fixed plate 210 shown in Figures (A-1) to (A-3) as shown in Figure 3, with the movable plate 220 shown in Figures (B-1) to (B-3) as shown in Figure 3, stacked as shown in Figures (C-1) to (C-5). In Figure 2, (A-1), (B-1), and (C-1) are plan views, (A-2) is a cross-sectional view taken along line #A2 as seen in the direction of the arrow, (B-2) is a cross-sectional view taken along line #B2 as seen in the direction of the arrow, (C-2) is a cross-sectional view taken along line #C2 as seen in the direction of the arrow, (C-3) is a cross-sectional view taken along line #C3 as seen in the direction of the arrow, (C-4) is a cross-sectional view taken along line #C4 as seen in the direction of the arrow, and (A-3), (B-3), and (C-5) are perspective views.

[0014] In these figures, the fixed plate 210 has a pair of fan-shaped fixed bases 214 provided circumferentially symmetrically (point symmetrically about the center of rotation of the rotating shaft 110) on a ring portion 212 provided on the rotating shaft 110. A spring locking pin 256 for locking one end of a ring spring 258 (described later) is provided at each end of the fan-shaped fixed bases 214.

[0015] Next, the movable plate 220 has a pair of thick, fan-shaped movable bases 250 provided symmetrically in the circumferential direction on a portion of the ring portion 222 that moves around the ring portion 212 of the fixed plate 210, and the fan-shaped movable bases 250 are exposed between the fan-shaped fixed bases 214 of the fixed plate 210. In other words, the movable plate 220 is rotatably provided between the fixed plates 210, and the fan-shaped movable bases 250 of the movable plate 220 are exposed between the fan-shaped fixed bases 214 of the fixed plate 210. The rotation of the fan-shaped movable base 250 is restricted by the fan-shaped fixed bases 214, and the fan-shaped movable base 250 moves only between the fan-shaped fixed bases 214.

[0016] A pair of openings 226 are provided symmetrically in the circumferential direction in the ring portion 222 of the movable plate 220, close to the sector-shaped movable base 250. In other words, the sector-shaped fixed base 214 and the sector-shaped movable base 250 form a shutter that exposes and hides the openings 226.

[0017] Next, a locking protrusion 252 is provided on the surface of the sector-shaped movable base 250 near the spring locking pin 256 of the sector-shaped fixed base 214 (the end opposite the opening 226). When the lock control pin 122 (see FIG. 1) on the exchange arm 100 comes into contact with this locking protrusion 252, the sector-shaped movable base 250 rotates in the direction of arrow F1. When the sector-shaped movable base 250 rotates, the hidden opening 226 becomes exposed from the sector-shaped fixed base 214. On the sector-shaped movable base 250, spring locking pins 254 are respectively provided upright at the tips of the locking protrusions 252 so as to face the spring locking pins 256 of the sector-shaped fixed base 214. A ring spring 258 is locked between the movable-side spring locking pin 254 and the fixed-side spring locking pin 256.

[0018] This state is shown in Figure 4, where (A) shows a state in which the shutter is closed and the opening 226 is hidden, and (B) shows a state in which the exchange arm 100 has rotated in the direction of the arrow F1 from the state in Figure 1, opening the shutter and exposing the opening 226 in the sector-shaped movable base 250. In the state shown in (A) in Figure 4, the ring spring 258 is stretched, which urges the sector-shaped movable base 250 in the direction opposite to the arrow F1 in Figure 1, and the opening 226 is hidden by the sector-shaped fixed base 214.

[0019] 1, the lock control pin 122 on the exchange arm 100 slides from the sectorial fixed base 214 onto the sectorial movable base 250, as shown in FIG. 4(B). When it hits the locking projection 252 of the sectorial movable base 250, the sectorial movable base 250 rotates in the direction of arrow F4, and the ring spring 258 contracts in diameter. As a result, the opening 226 of the sectorial movable base 250 becomes exposed from the sectorial fixed base 214.

[0020] On the other hand, when the exchange arm 100 rotates in the direction opposite to the arrow F1 in Fig. 1, the lock control pin 122 on the exchange arm 100 side moves away from the locking protrusion 252 of the sector-shaped movable base 250. Then, the ring spring 258 expands in diameter, and the sector-shaped movable base 250 returns from the state shown in Fig. 4(B) to the state shown in Fig. 4(A). In other words, the ring spring 258 constitutes a return mechanism for the sector-shaped movable base 250.

[0021] 5 shows the above operation as viewed from a circumferential cross section. When the lock control pin 122 on the exchange arm 100 side comes into contact with the locking protrusion 252 of the sectorial movable base 250, as shown in FIG. 5(A), the sectorial movable base 250 rotates in the direction of arrow F4, and the ring spring 258 contracts in diameter. On the other hand, when the exchange arm 100 rotates in the opposite direction, as shown in FIG. 5(B), the ring spring 258 expands in diameter, and the sectorial movable base 250 rotates in the direction of arrow F5, which is opposite to arrow F4. When the exchange arm 100 further rotates, the lock control pin 122 on the exchange arm 100 side moves away from the locking protrusion 252.

[0022] Next, the operation of the lock control mechanism 200 and the tool lock mechanism 300 will be described with reference to Figure 6. Figures (A-1) and (A-2) show the tool in an unlocked state, and Figures (B-1) and (B-2) show the tool in a locked state. As shown in these figures, in the unlocked state, the lock pin 306 of the tool lock mechanism 300 abuts against the sectorial fixed base 214 of the lock control mechanism 200, and the opening 226 of the sectorial movable base 250 is not exposed. In addition, the ring spring 258 is in an expanded diameter state.

[0023] When the exchange arm 100 rotates from this state, the lock control pin 122 on the exchange arm 100 hits the locking protrusion 252 of the sectorial movable base 250, causing the sectorial movable base 250 to rotate and expose the opening 226 of the sectorial movable base 250 from the sectorial fixed base 214. Then, the lock pin 306 of the tool lock mechanism 300 descends and fits into the opening 226, transitioning from the state shown in FIGS. 1A-1 and 1A-2 to the state shown in FIGS. 1B-1 and 1B-2. This causes the link piece 308 to be displaced as shown in FIG. 1B-1, causing the lock arm 310 to extend and lock the tool with the tip 312. At this time, the ring spring 258 is in a contracted state as shown in FIG. 1B-2.

[0024] An oil seal 190 is provided between the tool locking mechanism 300 and the tool changing arm 100, etc., as needed.

[0025] Next, the overall operation of this embodiment will be described. (1) Origin position: The origin position of the exchange arm 100 is the position shown in Fig. 1. At this time, the tool locking mechanism 300 is in a state in which the tip 312 of the locking arm 310 does not protrude, as shown on the left side of Fig. 2 and in Figs. 6(A-1) and (A-2).

[0026] (2) Tool Lock: Next, to perform tool exchange, the exchange arm 100 is rotated 90 degrees in the direction of the arrow F1 in FIG. a. The lock control mechanism 200 changes from the left side to the right side of Fig. 2, from Fig. 4(A) to Fig. 4(B), or from Fig. 6(A-2) to Fig. 6(B-2). Also, the tool lock mechanism 300 changes from the left side to the right side of Fig. 2, or from Fig. 6(A-1) to Fig. 6(B-1). b. That is, when the sectorial movable table 250 rotates in the direction of arrow F1 in conjunction with the rotation of the exchange arm 100, the opening 226 is exposed as the sectorial movable table 250 moves. In other words, the shutter opens. Then, the lock pin 306 of the tool locking mechanism 300 descends and fits into the opening 226, the link piece 308 is displaced, and the lock arm 310 extends, locking the tool with the tip 312. Meanwhile, the ring spring 258 enters a contracted state. c) This operation changes the exchange arm 100 from the state shown in Fig. 1 to the state shown in Fig. 7. That is, the tools 20A and 20B come into contact with the gripping portion 140 at the tip of the exchange arm 100, and the tip portion 312 of the locking arm 310 of the tool locking mechanism 300 protrudes, locking the tools 20A and 20B.

[0027] (3) Tool removal: Next, the rotary shaft 110 is slid in the axial direction to push down the exchange arm 100, and the tools 20A and 20B are removed from the tool magazine or the spindle of the machine tool.

[0028] (4) Tool exchange: Next, the rotary shaft 110 is rotated, and the exchange arm 100 rotates 180 degrees in the direction indicated by the arrow F6 in Fig. 7. At this time, the lock control mechanism 200 and the tool lock mechanism 300 rotate as a whole. As a result, the tools 20A and 20B are exchanged.

[0029] (5) Tool unlock: Next, when the exchange arm 100 rises, a) The tool locking mechanism 300 changes from the right side of FIG. 2 to the left side of FIG. 2, or from FIG. 6 (B-1) to FIG. 6 (A-1). b) The lock control mechanism 200 changes from FIG. 4(B) to FIG. 4(A), or from FIG. 6(B-2) to FIG. 6(A-2).

[0030] (6) Return to origin: Next, when the exchange arm 100 rotates in the reverse direction of the arrow F7 from the state shown in FIG. 7, the lock control pin 122 of the exchange arm 100 moves in the direction opposite to the arrow F1 in FIG. b) Then, the sector-shaped movable base 250 rotates in the direction opposite to the arrow F1. As a result, the opening 226 of the sector-shaped movable base 250 is blocked by the sector-shaped fixed base 214. In other words, the shutter is in a closed state. c) In this state, when the exchange arm 100 is lowered, the lock control pin 122 of the exchange arm 100 comes into contact with the sector-shaped fixed base 214, and the exchange arm 100 returns to the unlocked state of FIG.

[0031] As described above, according to this embodiment, the locking, extraction, replacement, unlocking, and return of the tool can be performed only by the movement of the exchange arm 100. a) The tool is securely locked before being pulled out, preventing the tool from falling off during replacement. b) The series of tool change operations can be performed smoothly. [Example]

[0032] Next, a second embodiment of the present invention will be described with reference to FIG. 8. This embodiment is an improved tool lock mechanism. The figures show the transition from the tool unlocked state (A) to the tool locked state (C). In these figures, a tool lock mechanism 350 includes an outer tube 352, a spring 354, and a lock pin 356. The lock pin 356 is biased toward the lock control mechanism 200 by the spring 354. A link piece 358 is provided between the lock pin 356 and the lock arm 310. As the lock pin 356 moves up and down in conjunction with the rotation of the exchange arm 100, the link piece 358 is displaced from (A) to (B) to (C) in the figures, thereby locking the tool with the tip 312 of the lock arm 310.

[0033] In this embodiment, a slide shaft 360 is provided at the center of the outer cylinder 352, and the lock pin 356 slides along this slide shaft 360. A spring 354 is provided around the slide shaft 360. Furthermore, in this embodiment, a ball bearing 362 is rotatably provided at the tip of the lock pin 356.

[0034] In this embodiment, the lock pin 356 slides along the slide shaft 360, which allows the lock pin 356 to slide smoothly and ensures that the locking operation is performed reliably by the link piece 358. In addition, a ball bearing 362 is provided at the tip of the lock pin 356, which allows the lock pin 356 to move smoothly when it abuts on the fan-shaped fixed base 214 of the lock control mechanism 200. [Example]

[0035] Next, a third embodiment of the present invention will be described with reference to FIG. 9. This embodiment also features an improved tool lock mechanism. FIG. 9(A) shows the tool unlocked state, and FIG. 9(B) shows the tool locked state. The tool lock mechanism 370 in FIG. 9 houses a spring 374 and a lock pin 376 inside an outer cylinder 352, and an inclined surface 377 is formed on the side of the lock pin 376.

[0036] On the other hand, an inclined surface 311 is provided at the end of the locking arm 310, which is adapted to join with the inclined surface 377. Furthermore, a guide plate 380 is provided at the middle position of the locking arm 310, so that the guide plate 380 moves in the sliding direction of the locking arm 310. This guide plate 380 is provided with a guide hole 382. A guide protrusion 384 extends from the extension portion 130 of the exchange arm 100 into this guide hole 382, ​​so that the guide plate 380 slides while being guided by the guide protrusion 384.

[0037] In this embodiment, when the lock pin 376 descends, its inclined surface 377 comes into contact with the inclined surface 311 of the lock arm 310, pushing the lock arm 310 toward the tool and locking the tool. At this time, the guide plate 380 slides while being guided by the guide protrusion 384, so the sliding movement of the extension portion 130 can be performed stably and smoothly. Note that the guide plate 380 may be provided on the extension portion 130 side of the arm 100, and the guide protrusion 384 may be provided on the lock arm 310 side. [Example]

[0038] Next, a fourth embodiment of the present invention will be described with reference to Fig. 10. In the above-described embodiment, two return mechanisms for the sector-shaped movable base 250 using the ring spring 258 of the lock control mechanism 200 are provided at an angle of 180 degrees around the rotation axis 110, but in this embodiment, only one is provided. The basic operation is the same as in the above-described embodiment.

[0039] Other Embodiments The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the present invention. For example, the following modifications are also included. (1) The shapes and dimensions of the components shown in the above embodiments are merely examples, and the design can be modified to achieve the same functions. For example, in the above embodiments, the return mechanism is configured using a ring spring, but other appropriate spring means may be used, and the arrangement of the spring means may also be set appropriately. (2) In the above embodiment, the tool is replaced by moving in the vertical direction, but the tool may be moved in any other appropriate direction, such as horizontally. (3) The above embodiments may be combined. For example, the tool locking mechanism of Figures 8 and 9 may be applied to other embodiments, or Figures 8 and 9 may be combined. (4) The automatic tool changer of the present invention can be used in various machine tools, such as machining centers, CNC (computer numerical control) machines, milling machines, lathes, and laser cutting machines. [Industrial Applicability]

[0040] As described above, according to the present invention, the locking, extraction, replacement, unlocking, and return of a tool can be performed simply by moving the replacement arm 100, allowing the series of tool replacement operations to be performed smoothly, making it suitable for automatic tool replacement in various machine tools. [Explanation of symbols]

[0041] 10: Automatic tool changer 20A,20B:Tools 100: Replacement arm 110: Rotation axis 120: Center 122: Lock control pin 130: Extension part 140: Grip part 142:Aperture 190: Oil seal 200: Lock control mechanism 210: Fixed plate 212: Ring section 214: Fan-shaped fixed stand 220: Movable plate 222: Ring section 226: Opening 250: Fan-shaped movable platform 252: Locking protrusion 254: Spring locking pin 256: Spring locking pin 258: Ring spring 300: Tool locking mechanism 302: Outer cylinder 304: Spring 306: Lock pin 308: Link piece 310: Lock Arm 311: Inclined surface 312:Tip 350: Tool locking mechanism 352: Outer cylinder 354: Spring 356: Lock pin 358: Link piece 360:Slide axis 362: Ball Bear 370: Tool locking mechanism 374: Spring 376: Lock pin 377: Inclined surface 380: Guide plate 382: Guide hole 384: Guide protrusion

Claims

1. An automatic tool changer that changes tools by rotating an exchange arm and moving it in the direction of a rotation axis, a tool locking mechanism for gripping and locking the tool is provided on the exchange arm; an automatic tool changer, characterized in that a lock control mechanism is provided at the center of the change arm, which controls locking and unlocking of the tool by the tool lock mechanism in accordance with rotation of the change arm;

2. The exchange arm is extension portions provided in opposite directions from the center; a tool gripping portion provided at each tip of the extension portion; 2. The automatic tool changer according to claim 1, further comprising:

3. The tool locking mechanism includes: a lock arm slidably provided on the extension portion and configured to lock the tool held by the grip portion; a lock pin that is displaced in the direction of the rotation axis of the exchange arm; a slide means for sliding the lock arm; 3. The automatic tool changer according to claim 2, wherein said lock control mechanism slides said lock arm by said sliding means when said lock pin is displaced.

4. The lock control mechanism includes: The exchange arm includes a fixed plate provided on a rotation shaft of the exchange arm, and a movable plate that rotates relative to the fixed plate, The movable plate is provided with an opening into which the lock pin fits, When the tool is locked, the movable plate is rotated in accordance with the rotation of the exchange arm to expose the opening from the fixed plate; 4. An automatic tool changer according to claim 3, wherein when the tool is unlocked, the movable plate is rotated by a return means provided between the fixed plate and the movable plate, so that the opening is hidden by the fixed plate.

5. 5. The automatic tool changer according to claim 4, wherein a spring means is provided between the movable plate and the fixed plate for covering the opening of the movable plate with the fixed plate when the change arm returns from the locked state to the unlocked state, thereby returning the change arm to its pre-locked state.

6. 4. An automatic tool changer according to claim 3, wherein the sliding means for the locking arm of said tool locking mechanism is a link piece provided between said locking arm and said lock pin.

7. 4. An automatic tool changer according to claim 3, wherein the slide means for the lock arm of the tool lock mechanism is an inclined surface provided between the lock arm and the lock pin.

8. 4. An automatic tool changer according to claim 3, wherein a ball bearing is provided at the tip of the lock pin of said tool lock mechanism, which abuts against the fan-shaped fixing base of said fixing plate.

9. 3. The automatic tool changer according to claim 2, further comprising a guide means for guiding the tool in a sliding direction between the extension of the change arm and the lock arm.

10. A machine tool comprising the automatic tool changer according to any one of claims 1 to 9.

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