Cutting tool changer

Abstract

To provide a blade tool replacement device for a processing tool that can automatically, securely and stably replace a blade tool through the operation of a robot arm.SOLUTION: The present invention relates to a blade tool replacement device for a processing tool that comprises: a rotary drive part 9 which drives and rotates a spindle shaft; a spindle body 1 which is coupled to the rotary drive part 9, and rotatably holds the spindle shaft 10 inside; a clamp part 2 which is provided at a tip of the spindle shaft; a blade tool collet 3 which is clamped by the clamp part and fitted with a blade tool; and a blade tool magazine 8 which holds a plurality of blade tool collets. A gear part 35 is provided at an outer peripheral part of the blade tool collet 3, the blade tool magazine 8 is provided with a housing recessed part 80 which houses the blade tool collet, and a rack part 82 capable of engaging the gear part of the blade tool collet is provided at one wall part of the housing recessed part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a machining tool that is attached to a robot arm and rotates cutting tools such as carbide rotary bars and axle-mounted grinding wheels at high speed using a motor or the like in a rotation drive unit to perform processing such as chamfering, deburring, and lapping of a workpiece, and in particular to a cutting tool changer for a machining tool that changes various cutting tools on a spindle body of the machining tool by the operation of a robot arm. [Background technology]

[0002] Conventionally, a processing tool that is attached to the end of a robot arm, has a cutting tool attached to the end of a motor output shaft and rotates the cutting tool at high speed to perform processing such as deburring of a product is known, as disclosed in Patent Document 1 listed below.

[0003] This type of machining tool is usually attached to the end of a robot arm and is used in a fully automated manner through the operation of the robot arm, so when replacing the cutting tool, it is required to have a structure that allows the cutting tool to be replaced automatically.

[0004] For this reason, in this conventional machining tool, a movable member that moves axially by air pressure is provided inside the head of the machining tool, a chuck mechanism is arranged inside the movable member, and the movable member is slid axially by air pressure to open and close the chuck mechanism and automatically replace the cutting tool.

[0005] However, this conventional machining tool has a circuit for introducing compressed air within its head, a sliding mechanism for the moving member, and a chucking mechanism disposed inside the moving member, which results in a complex structure and inevitably a large head portion.

[0006] Machining tools for chamfering, deburring, wrapping, etc. of workpieces need to insert cutting tools into small parts and narrow spaces of various workpieces by the operation of a robot arm to perform the processing. However, if the head part of the machining tool becomes large, when the cutting tool is inserted into the small part of the workpiece, the head part interferes with the workpiece, making it difficult to process the small part of the workpiece.

[0007] Therefore, the present applicant proposed a cutting tool replacement device for a processing tool in the following Patent Document 2. This processing tool includes a rotation drive unit that rotates and drives a spindle shaft, a spindle body that is connected to the rotation drive unit and rotatably holds the spindle shaft inside, a clamp unit provided at the tip of the spindle shaft, and a cutting tool collet that is clamped to the clamp unit and has a cutting tool attached thereto, and a storage recess for storing the cutting tool collet is provided in a cutting tool magazine that holds a plurality of cutting tool collets.

[0008] Furthermore, a circular clamping groove is provided in the collet connection portion provided at the end of the tool collet, and the clamping portion is provided with a plurality of clamping balls that fit into the clamping groove, a clamping sleeve slidably fitted onto the outer periphery to urge the clamping balls inward, and a spring member that urges the clamping sleeve in the clamping direction, and a circular engagement groove is provided on the outer periphery of the tool collet.

[0009] Meanwhile, an engagement retaining portion capable of engaging with the engagement groove of the tool collet is provided in the storage recess of the tool magazine, and a clamping release portion is provided on the tool magazine which contacts the clamping sleeve and slides the clamping sleeve in the unclamping direction, and a twisting portion is provided within the engagement retaining portion which engages with the engagement groove to apply a twisting force to the tool collet when the tool collet is removed from the storage recess. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2014-94100 A [Patent Document 2] Patent No. 6650171 Summary of the Invention [Problem to be solved by the invention]

[0011] The cutting tool changer for machining tools configured as described above makes it possible to miniaturize the machining tools, and when storing them in the cutting tool magazine, the operation of the robot arm brings the clamping sleeve into contact with the clamping release portion, sliding the clamping sleeve in the unclamping direction, and releasing the cutting tool collet from the clamp portion.

[0012] On the other hand, when the clamp portion is clamped to a tool collet on a tool magazine and the tool collet is removed from the tool magazine, the robot arm operates to insert the clamp portion into the collet connection portion at the top of the tool collet, engages the clamp ball with the engagement groove of the collet connection portion, and the clamp sleeve is biased toward the clamp by the spring member and slides, so that the collet connection portion at the top of the tool collet is clamped to the clamp portion.

[0013] After that, the clamping part removes the tool collet from the storage recess of the tool magazine by operating the robot arm. At this time, the twisting part operates to engage with the engagement groove and apply a twisting force to the tool collet so that the clamping ball properly engages with the engagement dimple of the engagement groove and clamping is performed normally. This causes the tool collet to twist around its axis, and the clamping ball moves so as to properly engage with the engagement dimple of the engagement groove.

[0014] However, in this twisting unit, a ball plunger is attached to the storage recess of the tool magazine, and when the robot arm operates to move the tool collet away from the storage recess of the tool magazine, the ball plunger engages with the engagement dimple of the engagement groove to twist the tool collet. This can cause the twisting to become unstable, and if the twisting of the tool collet is not performed reliably, the clamping of the clamping unit becomes unstable. Furthermore, when the tool collet is repeatedly replaced, the ball movement of the ball plunger deteriorates, causing the twisting of the tool collet to become unstable, resulting in an unreliable clamping operation of the clamping unit.

[0015] The present invention is devised to solve the above-mentioned problems, and has an object to provide a cutting tool changer for a machining tool that can automatically, reliably and stably change cutting tools by the operation of a robot arm. [Means for solving the problem]

[0016] In order to achieve the above object, the cutting tool changing device of the present invention comprises: A cutting tool changing device for a machining tool, comprising: a rotation drive unit that rotates a spindle shaft; a spindle body that is connected to the rotation drive unit and rotatably holds the spindle shaft therein; a clamp unit provided at a tip of the spindle shaft; a cutting tool collet that is clamped to the clamp unit and has a cutting tool attached thereto; and a cutting tool magazine that holds a plurality of the cutting tool collets, A collet connection portion provided at an end of the cutting tool collet is provided with an annular clamp groove, and a plurality of dimples are provided within the clamp groove; The clamp portion is provided with a plurality of clamp balls that fit into the clamp grooves, a clamp sleeve that is slidably fitted onto the outer periphery of the clamp portion to urge the clamp balls inward, and a spring member that urges the clamp sleeve in the clamping direction; a gear portion is provided on an outer periphery of the cutting tool collet, a storage recess for storing the cutting tool collet is provided in the cutting tool magazine, a rack portion engageable with the gear portion of the cutting tool collet is provided on one wall of the storage recess so as to be floatable, and a clamp release portion is provided on the cutting tool magazine to contact the clamp sleeve and slide the clamp sleeve in an unclamping direction, When the cutting tool collet is removed from the storage recess, the gear portion and the rack portion engage with each other to apply a twisting force to the cutting tool collet.

[0017] According to the cutting tool changer of this invention, a cutting tool is attached to a robot arm, and the cutting tool collet held in the cutting tool magazine can be fitted into the clamp portion of the spindle shaft and clamped only by the operation of the robot arm without using any power source such as air pressure or electricity, and the clamp sleeve can be automatically slid to unclamp.

[0018] In addition, when the tool collet is clamped and removed from the tool magazine, the gear portion is engaged with the rack portion of the storage recess of the tool magazine and the tool collet is twisted to enter the clamped state, so the tool collet can always be properly connected and clamped to the clamp portion and attached so as to be rotatably driven. Furthermore, because the gear portion is engaged with the floating rack portion and twisted, excessive wear and friction do not occur, and there is no risk of the ball plunger deteriorating and the twisting action becoming unstable as occurs when a ball plunger is used, so the tool collet can be reliably replaced stably over a long period of time.

[0019] Furthermore, when storing the cutting tool collet in the cutting tool magazine, the clamp sleeve can be slid in the unclamping direction on the cutting tool magazine by the operation of the robot arm to release the cutting tool collet from the clamp portion and store the cutting tool collet in the storage recess of the cutting tool magazine. This allows the cutting tool collet with the attached cutting tool to be automatically and appropriately replaced.

[0020] Furthermore, since the clamping portion provided at the tip of the spindle shaft only requires the clamping ball to be disposed inside the clamping sleeve, the clamping portion can be made significantly smaller than machining tools that use pneumatic or electrical equipment for clamping. This makes it possible to perform machining such as chamfering, deburring, and lapping of the workpiece by inserting a cutting tool into small parts of the workpiece or into complex and narrow parts that are difficult to insert a cutting tool into, without the clamping portion interfering with the workpiece.

[0021] Furthermore, when the spindle body is operated by the robot arm to remove the cutting tool collet stored in the storage recess, it descends toward the cutting tool collet and engages the collet insertion hole of the clamp part of the spindle shaft so as to cover the collet connection part of the cutting tool collet. At this time, the end of the clamp sleeve abuts on the clamp release part to release the clamp while connecting the cutting tool collet to the clamp part, and the spindle body moves forward of the storage recess by the operation of the robot arm, the clamp sleeve of the clamp part slides on the inclined surface, and the clamp sleeve slides toward the clamp side due to the spring force of the spring member.

[0022] The gear portion of the tool collet then engages with the rack portion on the tool magazine, applying a twisting force to the tool collet, twisting it around the axis. This automatically brings the clamp ball in the clamp sleeve and the dimple in the clamp groove of the collet connection portion into a proper fit state, and when the tool collet leaves the storage recess, the clamp portion automatically and completely clamps the tool collet. Because the twisting force of the tool collet is applied via the gear portion and the rack portion, even if the tool collet is repeatedly replaced over a long period of time, deterioration of the gear portion and the rack portion is kept to a minimum, allowing the tool replacement device to operate normally over a long period of time.

[0023] Here, in the cutting tool changer for the machining tool, it is preferable that the rack portion is disposed inside the storage recess of the cutting tool magazine, parallel to the direction of movement of the cutting tool collet when it is removed, and supported via a gap and a spring so as to be floatable at least in the direction of the projections and recesses of the teeth. In this way, when the cutting tool collet is removed from the storage recess, the gear portion of the cutting tool collet and the rack portion are smoothly engaged with each other by the operation of the robot arm, and the cutting tool collet can be twisted and the clamping portion can be reliably and stably clamped while minimizing friction and wear of the gear portion and the rack portion.

[0024] Also, here, it is preferable that an entry recess is provided on the inner wall surface opposite the rack portion inside the storage recess of the tool magazine, and that a floating wall portion is supported in a floating manner on the wall surface of the entry recess.

[0025] According to this, when storing the cutting tool collet, the cutting tool collet is inserted from the front into the storage recess of the cutting tool magazine while the clamping portion clamps the cutting tool collet. At this time, the gear portion of the cutting tool collet can be biased toward the insertion recess by the operation of the robot arm. Furthermore, if the cutting tool collet is biased too much toward the floating wall portion during insertion, the gear portion only comes into contact with the floating wall portion, so the movement of the cutting tool collet is not hindered and wear of the gear portion can be minimized.

[0026] Also, here, it is preferable to arrange an optical sensor for detecting the state of the clamping portion near the storage recess of the tool magazine, and to configure the optical sensor to detect whether the clamping portion on the storage recess clamps the tool collet based on the reflection or blocking of light. Effect of the Invention

[0027] According to the cutting tool changing device of the present invention, the cutting tool collet for the processing tool can be automatically, reliably and stably changed by the operation of the robot arm. [Brief description of the drawings]

[0028] [Figure 1] 1 is a front view of a processing tool showing an embodiment of the present invention; [Diagram 2] FIG. 2 is an enlarged cross-sectional view taken along line II-II of FIG. [Diagram 3] 13 is a partial cross-sectional view of the clamp portion clamping the cutting tool collet. FIG. [Figure 4] FIG. 4 is a partial cross-sectional view of the cutting tool collet in an unclamped state. [Diagram 5] FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. 2 is a plan view with a partial cross section of the cutting tool magazine. [Figure 9] FIG. 13 is a front view of a multiple tool magazine with tool collets stored therein; [Figure 10] FIG. [Figure 11] 1A is an explanatory plan view of a cutting tool collet being removed from a cutting tool magazine, and FIG. 1B is a side view with a cross section thereof. [Figure 12] 1A is an explanatory plan view of a cutting tool collet being removed from a cutting tool magazine, and FIG. 1B is a side view with a cross section thereof. [Figure 13] 11A and 11B are an explanatory plan view and a side view with a cross section when the cutting tool collet is inserted into the storage recess of the cutting tool magazine. [Figure 14] 1A is a plan view illustrating a state in which a cutting tool collet is inserted into a storage recess of a cutting tool magazine and placed in a stored state, and FIG. [Figure 15] 13A is a front view of a multiple tool magazine with tool collets stored therein according to another embodiment, FIG. 13B is a BB cross-sectional view thereof, and FIG. 13C is a CC cross-sectional view thereof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] An embodiment of the present invention will be described below with reference to the drawings. As shown in Fig. 1, the processing tool is a tool in which a clamp part 2 is provided at the tip of a spindle shaft 10 of a spindle body 1, the spindle body 1 (rotation drive part 9) is attached to a robot arm RA or the like, and a cutting tool 7 clamped to the clamp part 2 is rotated at high speed to perform processing such as deburring of a product.

[0030] A cutting tool 7 for deburring or the like is fixed to the cutting tool collet 3, which is clamped to the clamp portion 2, and the cutting tool 7 is rotated at high speed by the rotational drive of the spindle body 1, thereby performing processes such as deburring, chamfering, and lapping on the workpiece.

[0031] A bearing member is provided within the spindle body 1, and a spindle shaft 10 is rotatably supported at the axial center position of the cylindrical case via the bearing member. A rotation drive unit 9 such as an electric motor is attached to the end of the spindle body 1, and the rotating shaft of the rotation drive unit 9 is connected to the end of the spindle shaft 10, which is rotated at high speed by the rotation drive unit 9.

[0032] 3 and 4, spindle tip 15 of spindle shaft 10 is a large diameter portion that protrudes from spindle body 1, and collet insertion hole 16 is formed in spindle tip 15 in the axial direction and opens to the tip side. Collet insertion hole 16 has an inner surface formed in a conical tapered shape, and as shown in FIG. 3, collet connection part 30 of cutting tool collet 3, which is similarly formed in a tapered shape, is shaped to be able to closely enter collet insertion hole 16.

[0033] 4, the tool collet 3 is made up of a tool fixing part 31 that fixes the tool 7, and a collet connecting part 30 provided on the upper part of the tool fixing part 31 via an engagement groove 34, and as described above, the collet connecting part 30 is inserted into and connected to the collet insertion hole 16. The collet connecting part 30 is formed slightly tapered, in other words, in a truncated cone shape, and a clamp groove 32 is formed on the outer periphery near the upper part, and within the clamp groove 32, a plurality of dimples (recesses having an approximately semicircular cross section) 33 are formed at predetermined intervals.

[0034] The clamp balls 14 are fitted into these dimples 33 to clamp the cutting tool collet 3 and transmit the rotational force of the spindle shaft 10 to the collet connecting portion 30. As shown in FIG. 2, for example, when six clamp balls 14 are used, twelve dimples 33 are formed in the clamp groove 32 at angular intervals of 30°. The six clamp balls 14 are rotatably fitted and held in a plurality of ball retaining holes 17 radially provided in a ring shape near the tip of the spindle shaft 10 at angular intervals of 60° as shown in FIG. 2. These six ball retaining holes 17 open to the inside and outside of the tip of the spindle shaft 10, and each clamp ball 14 in the ball retaining hole 17 is housed in the hole while being exposed to the inside and outside from the inside and outside openings of the ball retaining hole 17 (FIG. 4).

[0035] On the other hand, as shown in Fig. 3, the plate 12 is fitted into the back of the collet insertion hole 16 provided in the spindle tip 15 of the spindle shaft 10, and the biasing member 18 is arranged so as to bias the collet connecting portion 30 of the inserted cutting tool collet 3 toward the tip side by the coil spring 18a. As shown in Fig. 4, the biasing member 18 is slidably held within a predetermined position of the collet insertion hole 16 by a locking ring 21. Furthermore, the clamp sleeve 13 is fitted onto the outer periphery of the spindle tip 15 of the spindle shaft 10 so as to be slidable up and down within a predetermined range, and a spring member 19 (coil spring) that biases the clamp sleeve 13 toward the tip side (clamp side) is attached to the spindle tip 15. The clamp sleeve 13 is slidably held at a predetermined position of the spindle tip 15 by a locking ring 22.

[0036] As shown in Fig. 2, an engagement surface 13a is formed on the inner peripheral surface of the clamp sleeve 13, which contacts the outer peripheral surface of the spindle tip 15 including the clamp ball 14, and as shown in Fig. 4, when the clamp sleeve 13 slides upward, the clamp ball 14 engages with an annular groove 13b provided on the engagement surface 13a. This releases the engagement between the clamp ball 14 and the dimple 33 of the clamp groove 32, allowing the cutting tool collet 3 to be removed.

[0037] On the other hand, as shown in Figures 3 and 4, an engagement groove 34 is formed in an annular shape in the middle part of the cutting tool collet 3, i.e., on the outer periphery between the collet connecting part 30 and the cutting tool fixing part 31, and a gear part 35 is provided below the engagement groove 34.

[0038] As shown in Figures 11 and 12, when the tool collet 3 stored in the storage recess 80 of the tool magazine 8 is removed by the operation of the robot arm RA, the gear portion 35 engages with a rack portion 82 provided on one wall surface within the storage recess 80, thereby applying a twisting force to the tool collet 3 and twisting the tool collet 3 around its axis.

[0039] This twisting brings the clamp balls 14 into proper engagement with the dimples 33 in the clamp grooves 32, and the cutting tool collet 3 is properly clamped by the clamp portion 2. During this clamping, as shown in Figure 3, the clamp balls 14 come into contact with the inner peripheral surface of the clamp sleeve 13, which presses the clamp balls 14 inward toward the dimples 33, thereby establishing a clamped state.

[0040] An engagement groove 34 is provided in an annular shape on the outer periphery between the collet connection portion 30 and the gear portion 35 of the tool collet 3. The engagement retaining portion 81 of the tool magazine 8 engages with this engagement groove 34 when the tool collet 3 is stored and removed, and slidably holds the tool collet 3. The width of this engagement groove 34 is formed to be slightly wider than the thickness of the engagement retaining portion 81 of the tool collet 3 that engages with its inner side. As a result, when the robot arm RA is operated to clamp and remove the tool collet 3 from the storage recess 80, the robot arm RA moves finely up and down to impart up and down vibrations to the clamp sleeve 13, and the clamp sleeve 13 can be smoothly lowered to the clamp position.

[0041] A plurality of tool collets 3, each having a tool 7 fixed to a tool fixing portion 31, are stored in a storage recess 80 of a tool magazine 8, as shown in Fig. 9. Replaceable tools 7, each of which may be a carbide rotary burr, a grinding wheel, or the like, are inserted from the bottom of the tool fixing portion 31 of the tool collet 3, as shown in Fig. 3, and are then fastened and fixed in place with a fastening screw.

[0042] As shown in Figs. 4 to 9, the cutting tool magazine 8 is configured such that a plurality of storage recesses 80 are horizontally arranged side by side on a horizontal portion, and cutting tool collets 3 with cutting tools are stored in the plurality of storage recesses 80. Each storage recess 80 is formed to open forward in a substantially U-shape, and a U-shaped engagement holding portion 81 that engages with the engagement groove 34 of the cutting tool collet 3 and holds the cutting tool collet 3 is formed on the periphery of the storage recess 80. As shown in Figs. 13 and 14, when the cutting tool collet 3 advances into the storage recess 80 by the operation of the robot arm RA, the engagement holding portion 81 engages with the engagement groove 34 to hold it, and the cutting tool collet 3 advances to the back of the storage recess 80 and is held by the engagement holding portion 81.

[0043] As shown in Figs. 6 and 8, a rack portion 82 capable of engaging with the gear portion 35 of the cutting tool collet 3 is disposed on the left wall portion of the storage recess 80 as viewed from the front. The rack portion 82 is disposed in a floating state (floatably) via a gap 82b, a spring 82a, a guide pin 82c, and an elongated hole 82d. The rack portion 82 is provided with an elongated hole 82d that is long in the concave and convex direction of the teeth, and the guide pin 82c is inserted into the elongated hole. As shown in Fig. 8, a gap 82b is provided on the rear side of the rack portion 82, and two springs (coil springs) 82a are hung across the gap 82b. As a result, the rack portion 82 can float in the left-right direction as viewed from the front, that is, in the concave and convex direction of the teeth, within a small range of the gap 82b, via the guide pin 82c and the elongated hole 82d, and when a load is applied in the concave and convex direction of the teeth, the rack portion 82 easily floats via the spring (coil spring) 82a.

[0044] Furthermore, an entry recess 86 is provided on the right wall inside the storage recess 80, opposite the rack portion 82. This entry recess 86 has a shape in which the right wall is set back inward by a width α, as shown in Fig. 6, in order to avoid contact between the gear portion 35 and the rack portion 82 when the tool collet 3 is inserted into the storage recess 80 from the front by the operation of the robot arm RA. Due to this entry recess 86 of width α, when the tool collet 3 is inserted into the storage recess 80 from the front, as shown in Fig. 13, the entry recess 86 of width α causes the tool collet 3 to enter biased by the width α toward the entry recess 86, thereby avoiding contact between the gear portion 35 and the rack portion 82.

[0045] 8, a floating wall portion 83 is disposed in a floating state on the wall surface of the entry recess 86 via a spring 83a and a gap 83b. The floating wall portion 83, like the rack portion, is movable in a small range in the left-right direction when viewed from the front via a guide pin and a long hole, and is held in a floating state in the thickness direction of the wall via a spring (coil spring) 83a. When the cutting tool collet 3 is inserted from the front into the storage recess 80, biased toward the entry recess 86, this floating wall portion 83 allows the floating wall portion 83 to move if the gear portion 35 of the cutting tool collet 3 comes into contact with the floating wall portion 83, thereby avoiding excessive collision or contact between the gear portion 35 and the wall portion.

[0046] 12, when the robot arm RA operates to remove the tool collet 8 from the storage recess 80, the gear portion 35 of the tool collet 8 engages with the rack portion 82, and the gear portion 35, i.e., the tool collet 3, is twisted. This allows the clamp ball 14 to easily fit into the dimple 33, as shown in FIGS. 2 and 3. As a result, the clamp sleeve 13 is lowered by the spring member 19, the clamping operation of the clamp portion 2 is reliably performed, and the driving force of the spindle shaft 10 can be reliably transmitted to the tool collet 3.

[0047] When gear portion 35 moves in the longitudinal direction of rack portion 82, gear portion 35 and rack portion 82 can smoothly engage with each other regardless of the angular position of gear portion 35, and further, gear portion 35 smoothly disengages from the end portion of rack portion 82, so there is no need to detect the angular position of tool collet 3 or to implement precise control to keep that angular position constant.

[0048] 5 to 9, clamp releasing portions 84 are formed as slightly elevated protrusions via inclined surfaces 85 on both sides of each storage recess 80 of the tool magazine 8. When storing and unclamping the tool collet 3, as shown in Figs. 13 and 14, the clamp releasing portions 84 are formed so as to gradually push up the clamp sleeve 13 of the tool collet 3 that has reached that position via the inclined surfaces 85, thereby bringing the tool collet 3 into an unclamped state and separating it from the clamp portion 2.

[0049] In other words, as shown in Figures 7 and 8, a slope 85 is formed continuously in front of the clamp release portion 84 on the tool magazine 8 so that it becomes higher toward the back, and when the tool collet 3 is stored and unclamped, the clamp sleeve 13 of the tool collet 3 is gradually lifted by the slope 85.

[0050] 13 and 14, when the operation of the robot arm RA causes the cutting tool collet 3 to move together with the spindle body 1, and the cutting tool collet 3 enters the storage recess 80 from the front toward the back, the lower end of the clamp sleeve 13 of the cutting tool collet 3 comes into contact with the inclined surface 85. As a result, the clamp sleeve 13 is lifted while sliding on the inclined surface 85, and when it reaches the clamp release portion 84, the outer side of the clamp ball 14 in the clamp sleeve 13 fits into the annular groove 13b of the engagement surface 13a. As a result, the engagement between the clamp ball 14 and the dimple 33 on the collet connection portion side is released, and the clamp by the clamp sleeve 13 is released.

[0051] Then, when the spindle body 1 rises due to the operation of the robot arm RA, the cutting tool collet 3 disengages from the clamp portion 2 of the spindle shaft 10 as shown in Fig. 3, and the engagement holding portion 81 of the storage recess 80 engages with the engagement groove 34 of the cutting tool collet 3, so that the cutting tool collet 3 is held in a fixed position at the back of the storage recess 80. As shown in Figs. 7 and 8, positioning members 87 are disposed on both sides of the engagement holding portion 81 at the fixed position at the back of the storage recess 80, and hold the stored cutting tool collet 3 in an appropriate storage position.

[0052] On the other hand, when the spindle body 1 is to again mount the cutting tool collet 3 for cutting tool replacement or the like after removing the cutting tool collet 3, the spindle body 1 moves its clamp portion 2 by the robot arm RA so as to align it with the cutting tool collet 3 on the storage recess 80 of the cutting tool magazine 8, as shown in Fig. 11. Then, the clamp portion 2 is lowered so that the collet connecting portion 30 of the cutting tool collet 3 on the cutting tool magazine 8 is fitted into the collet insertion hole 16.

[0053] In this state, when the spindle body 1 moves horizontally to the front of the tool magazine 8 by the operation of the robot arm RA, the tool collet 3 held by the engagement holding portion 81 in the storage recess 80 moves forward as shown in FIG. 11.

[0054] 11 and 12, the gear portion 35 of the tool collet 3 engages with the rack portion 82 in the storage recess 80, a twisting force is applied to the tool collet 3, and the tool collet 3 is twisted around its axis. At this time, the clamp ball 14 of the clamp portion 2 properly fits into the dimple 33 of the clamp groove 32 on the tool collet 3 side, and the clamp sleeve 13 moves down due to the spring force of the spring member 19. In this state, as shown in the cross-sectional view of FIG. 2, the clamp ball 14 of the clamp portion 2 has its inner portion properly fitted into the dimple 33 of the collet connecting portion 30 of the tool collet 3, and the tool collet 3 is clamped to the clamp portion 2.

[0055] Next, an embodiment of the cutting tool changer of the above-mentioned configuration will be described. As shown in Fig. 10, the spindle body 1 of the cutting tool is attached to the tip of the robot arm RA. A plurality of cutting tool collets 3 to which various cutting tools 7 are fixed are held in a storage recess 80 on a cutting tool magazine 8 with their engagement holding parts 81 engaged with engagement grooves 34, as shown in Fig. 9.

[0056] When clamping the cutting tool collet 3 to the clamp portion 2 of the spindle body 1, as shown in Fig. 11, the robot arm RA is operated to position the clamp portion 2 directly above the cutting tool collet 3 on the cutting tool magazine 8. Then, when the spindle body 1 is lowered directly downward, the collet connection portion 30 of the cutting tool collet 3 fits into the collet insertion hole 16 of the clamp portion 2, as shown in the right diagram of Fig. 11.

[0057] At this time, the clamp sleeve 13 of the clamp part 2 is in the upper unclamped position as shown in Fig. 11. The clamp ball 14 is engaged with the annular groove 13b of the engagement surface 13a inside the clamp sleeve 13, so there is no pushing out towards the inward collet connecting part 30. Therefore, the collet connecting part 30 fits into the collet insertion hole 16 up to the appropriate clamped position.

[0058] Next, by the operation of the robot arm RA, the spindle body 1 moves horizontally together with the cutting tool collet 3 toward the opening side of the storage recess 80. At this time, as shown in Figures 11 and 12, the gear portion 35 of the cutting tool collet 3 engages with the rack portion 82 below the engagement holding portion 81 and moves, and a twisting force is applied as the cutting tool collet 3 moves, and the cutting tool collet 3 is twisted around its axis. At the same time, the lower end of the clamp sleeve 13 slides on the inclined surface 85 to the right in Figures 11 and 12 toward the opening side, and the clamp sleeve 13 gradually descends due to the spring force of the spring member 19.

[0059] At this time, as shown in Fig. 12, the clamp ball 14 leaves the annular groove 13b and reaches the engagement surface 13a inside the clamp sleeve 13, which presses the clamp ball 14 inward. As a result, as shown in the right diagram of Fig. 12, the clamp ball 14 fits into the dimple 33 of the clamp groove 32 of the collet connecting part 30, resulting in a clamped state.

[0060] In this way, the clamp sleeve 13 descends while the tool collet 3 is twisted by the engagement between its gear portion 35 and rack portion 82. Therefore, even if the position of the clamp ball 14 and the angular position of the dimple 33 do not exactly match, the twisting of the tool collet 3 will cause their angular positions to match, and as shown in the cross-sectional view of Figure 2, the clamp ball 14 will fit exactly into the dimple 33, completing the clamping of the tool collet 3.

[0061] 12, the robot arm RA can be moved up and down to apply vertical vibration to the cutting tool collet 3. This ensures that the clamp sleeve 13 can be lowered reliably, and prevents the cutting tool collet 3 from being clamped improperly due to improper lowering of the clamp sleeve 13.

[0062] In this way, the collet connecting portion 30 of the cutting tool collet 3 is inserted into the collet insertion hole 16 of the clamping portion 2 simply by the operation of the robot arm RA, completing the clamping. After this, the rotation drive portion 9 is started, and the spindle shaft 10 and the cutting tool collet 3 are rotated at high speed, and the robot arm RA, in a teaching mode or the like, moves the cutting tool 7 along the processing line of the workpiece W (FIG. 10) fixed on the work table based on pre-stored coordinate data, and performs processing such as deburring.

[0063] When machining is to be performed after replacing with another cutting tool collet 3, first, in order to return the cutting tool collet 3 clamped in the clamp unit 2 to the storage recess 80 of the cutting tool magazine 8, the robot arm RA is moved to cause the cutting tool collet 3 to enter the empty storage recess 80 from its front opening, as shown in Figs. 13 and 14. At this time, as shown in Figs. 13 and 14, the robot arm RA causes the cutting tool collet 3 to enter the storage recess 80 from the front while biasing the spindle body 1 and the cutting tool collet 3 to the right (the side of the entrance recess 86) by the width α of the entrance recess 86 in a plan view. As a result, when the gear part 35 of the cutting tool collet 3 passes through the rack part 82, the rack part 82 and the gear part 35 enter without coming into contact with each other, and wear and damage to the gear part 35 and the rack part 82 can be prevented. Then, when the tool collet 3 held by the clamp portion 2 reaches the middle portion of the storage recess 80, the tool collet 3 advances along the center line C of the storage recess 80, and advances into the depth of the storage recess 80 while its engagement groove 34 engages with the engagement holding portion 81.

[0064] 13 and 14, the lower end of the clamp sleeve 13 slides along an inclined surface 85 on the tool magazine 8, and the clamp sleeve 13 is gradually lifted up by the inclined surface 85. When the lower end of the clamp sleeve 13 reaches the clamp release portion 84 of the tool magazine 8, the annular groove 13b of the engagement surface 13a in the clamp sleeve 13 engages with the clamp ball 14, and the clamp ball 14 becomes movable outward from the dimple 33 on the collet connection portion 30 side, and the clamp sleeve 13 enters an unclamped state.

[0065] In this state, the engagement groove 34 of the tool collet 3 is engaged and held in the engagement holding portion 81 of the storage recess 80, so when the clamp portion 2 of the spindle body 1 rises due to the operation of the robot arm RA, as shown in Figure 14, the tool collet 3 disengages from the clamp portion 2 and is held within the storage recess 80, and the clamp portion 2 returns to an empty state without the tool collet 3.

[0066] Next, the clamp part 2 of the spindle body 1 is moved by the operation of the robot arm RA to above the blade collet 3 on the blade magazine 8 to be replaced. Then, similar to the explanation of Fig. 11 above, the clamp part 2 moves to directly above the blade collet 3 on the blade magazine 8, and the spindle body 1 descends directly below. At this time, the collet connecting part 30 of the blade collet 3 fits into the collet insertion hole 16 of the clamp part 2, and the clamp ball 14 engages with the annular groove 13b of the engagement surface 13a in the clamp sleeve 13, so that the collet connecting part 30 fits into the collet insertion hole 16 to the appropriate clamp position.

[0067] Next, by the operation of the robot arm RA, the spindle body 1 moves horizontally together with the tool collet 3 toward the opening side of the storage recess 80, as shown in Fig. 11. At this time, the tool collet 3 moves with its gear portion 35 engaged with the rack portion 82 of the storage recess 80 of the tool magazine 8, whereby a twisting force is applied to the tool collet 3, and the tool collet 3 is twisted around its axis. At this time, because the rack portion 82 is in a floating state, excessive friction or wear does not occur between the gear portion 35 and the rack portion 82, and the tool collet 3 is twisted smoothly around its axis.

[0068] At the same time, as shown in Fig. 12, the lower end of the clamp sleeve 13 slides on the inclined surface 85 and advances toward the opening side, and the clamp sleeve 13 descends due to the spring force of the spring member 19. This causes the engagement surface 13a inside the clamp sleeve 13 to press the clamp ball 14 inward, and as shown in the right diagram of Fig. 12, the clamp ball 14 properly engages with the dimple 33 in the clamp groove 32 of the collet connecting portion 30, and the cutting tool collet 3 is clamped to the clamp portion 2. In this state, the cutting tool collet 3 is rotated at high speed, and machining is performed by the cutting tool collet 3.

[0069] In this way, in the cutting tool changer for the above-mentioned machining tools, the machining tools are attached to the robot arm RA, and the cutting tool collet 3 held in the cutting tool magazine 8 can be fitted into the clamp portion 2 of the spindle shaft 10 and clamped only by the operation of the robot arm RA without using power such as air pressure or electricity, and the clamp sleeve 13 can be automatically slid to release the clamp. Furthermore, when clamping the cutting tool collet 3, the clamp ball 14 is engaged with the dimple 33 of the clamp groove 32, and the cutting tool collet 3 is brought into a clamped state while being twisted, so that the cutting tool collet 3 can always be properly connected and clamped to the clamp portion 2 and attached so as to be rotatably driven.

[0070] Furthermore, when storing the cutting tool collet 3 in the cutting tool magazine 8, the clamp sleeve 13 is slid in the unclamping direction by the operation of the robot arm RA, and the cutting tool collet 3 is detached from the clamp unit 2, and the cutting tool collet 3 can be stored in the cutting tool magazine 8. This allows the cutting tool collet 3 with the cutting tool 7 attached to be properly replaced.

[0071] Furthermore, when the clamp unit 2 clamps the cutting tool collet 3, the gear portion 35 of the cutting tool collet 3 engages with and moves the floating rack portion 82 of the cutting tool magazine 8, and the cutting tool collet 3 is twisted around the axis. As a result, the clamp ball 14 fits properly with the dimple 33 of the collet connecting portion 30, and the clamp sleeve 13 moves down due to the spring force of the spring member 19, and the clamp sleeve 13 is in the clamped position. In this way, when a twisting force is applied to the cutting tool collet 3, the gear portion 35 engages with the floating rack portion 82, so that excessive friction and wear of the gear portion 35 and the rack portion 82 do not occur even if the cutting tool collet 3 is repeatedly replaced over a long period of time. As a result, deterioration of the gear portion 35 and the rack portion 82 is kept to a minimum, and the cutting tool replacement device can be operated without failure for a long period of time.

[0072] FIG. 15 shows another embodiment, in which a pair of optical sensors 88 are installed on the cutting tool magazine 8, and the optical sensors 88 detect the clamping state of the clamping portion 2 that clamps the cutting tool collet 3.

[0073] 15, a pair of light-transmitting optical sensors 88 are installed facing each other on the cutting tool magazine 8. A laser sensor that emits and receives a thin laser beam is used as the optical sensor 88, but a normal infrared light-transmitting photoelectric switch can also be used.

[0074] 15(c), the laser light L of the optical sensor 88 is positioned so as to detect the lower end of the clamp sleeve 13. In other words, the position of the laser light L of the optical sensor 88 is set so as to detect the presence or absence of the lower end of the clamp sleeve 13 when the clamp portion 2 clamps the cutting tool collet 3 in the storage recess 80, the engagement between the gear portion 35 and the rack portion 82 ends, the opening exit is reached, and the clamp portion 2 temporarily stops moving.

[0075] 12, when the clamp section 2 clamps the cutter collet 3 in the storage recess 80, moves to the opening side, the gear section 35 engages with the rack section 82, and the clamp section 2 stops moving at a fixed position, as shown in FIG 15(c), the optical sensor 88 emits a laser beam, and the laser beam L is directed toward the lower end of the clamp sleeve 13 to detect whether the clamp sleeve 13 has descended to a predetermined clamp position. At this time, when the laser beam L of the optical sensor 88 is blocked by the lower end of the clamp sleeve 13 or detects that lower end, it is confirmed that the clamp sleeve 13 has completely descended to the clamp position and is in a clamped state.

[0076] On the other hand, if the optical sensor 88 does not detect the lower end of the clamp sleeve 13, this is determined to be a failure to lower the clamp sleeve 13 (clamping failure), and the robot arm RA moves up and down to apply vertical vibration to the clamp sleeve 13 and perform the clamping operation again, as shown in Fig. 12. Then, if the optical sensor 88 detects the lower end of the clamp sleeve 13, the clamp unit 2 clamping the tool collet 3 moves so as to release the tool collet 3 from within the storage recess 80. This detection of a clamping failure of the clamp unit 2 by the optical sensor 88 effectively prevents problems such as the tool collet 3 falling off. [Explanation of symbols]

[0077] 1 Spindle body 2 Clamp section 3 Cutting tool collet 7 Cutting tools 8 Tool Magazine 9 Rotation drive unit 10 Spindle axis 12 Plate 13 Clamp sleeve 13a Engagement surface 13b Annular groove 14 Clamp Ball 15 Spindle tip 16 Collet insertion hole 17 Ball Retaining Hole 18 Pressing member 18a Coil spring 19 Spring material 21 Locking ring 22 Locking ring 30 Collet connection part 31 Cutting tool fixing part 32 Clamp groove 33 Dimples 34 Engagement groove 35 Gear section 80 Storage recess 81 Engagement holding part 82 Rack section 82a Spring 83 Floating wall 83a Spring 84 Clamp release part 85 Slope 86 Entry recess 87 Positioning member 88 Optical Sensor

Claims

1. A cutting tool changing device for a machining tool, comprising: a rotation drive unit that rotates a spindle shaft; a spindle body that is connected to the rotation drive unit and rotatably holds the spindle shaft therein; a clamp unit provided at a tip of the spindle shaft; a cutting tool collet that is clamped to the clamp unit and has a cutting tool attached thereto; and a cutting tool magazine that holds a plurality of the cutting tool collets, A collet connection portion provided at an end of the cutting tool collet is provided with an annular clamp groove, and a plurality of dimples are provided within the clamp groove; The clamp portion is provided with a plurality of clamp balls that fit into the clamp grooves, a clamp sleeve that is slidably fitted onto the outer periphery of the clamp portion to urge the clamp balls inward, and a spring member that urges the clamp sleeve in the clamping direction; A gear portion is provided on the outer periphery of the cutting tool collet, The cutting tool magazine is provided with a storage recess for storing the cutting tool collet, a rack portion engageable with the gear portion of the tool collet is provided on one wall portion of the storage recess so as to be capable of floating; and a clamp release portion is provided on the tool magazine for contacting the clamp sleeve to slide the clamp sleeve in an unclamping direction; When the cutting tool collet is removed from the storage recess, the gear portion and the rack portion engage with each other to apply a twisting force to the cutting tool collet.

2. 2. The cutting tool changing device for a machining tool according to claim 1, wherein the rack portion is disposed inside the storage recess of the cutting tool magazine, parallel to the movement direction when the cutting tool collet is removed, and is supported so as to be floatable at least in the direction of the teeth concave and convex via a gap and a spring.

3. 3. The cutting tool changing device for a machining tool according to claim 1, wherein an entry recess is provided on an inner wall surface opposite the rack portion inside the storage recess of the cutting tool magazine, and a movable wall portion is supported so as to be capable of floating on the wall surface of the entry recess.

4. 2. The cutting tool changing device for a machining tool according to claim 1, characterized in that an optical sensor for detecting the state of the clamping portion is provided near the storage recess of the cutting tool magazine, and when the clamping portion on the storage recess clamps the cutting tool collet, the optical sensor detects whether the clamping is successful based on the reflection or blocking of light.

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