Machine tool processing tool retention failure detection device and method

Abstract

The present invention provides a machining tool holding failure detection device for a machine tool, which is provided with a lock member (18) having a different displacement position when a machining tool (6) is held between a pair of tool holding portions (14) of each machining tool holding mechanism (8) in a tool magazine (4) in a normal held position and when the machining tool (6) is held in a position deviating from the normal held position, detects a position of a detected portion (22) which moves integrally with the lock member (18) by a predetermined detector (25) provided on the machine tool (1), and detects a holding failure detection state of the machining tool (6) in the machining tool holding mechanism (8). In this device, the risk of a malfunction or damage of the machine tool (1) due to the machining tool (6) not being normally held in the tool magazine (4) can be effectively prevented.

Description

Technical Field

[0001] This invention relates to a device and method for detecting poor tool retention in machine tools. Background Technology

[0002] A type of machine tool is becoming increasingly common, which stores multiple detachable machining tools in a tool magazine and selectively replaces tools from the stored tools with those suitable for the machining purpose on the machining spindle while performing various machining operations on the workpiece. The applicant has proposed a device capable of easily and reliably transferring machining tools from the tool magazine to the machining spindle (see, for example, Patent Document 1).

[0003] [Previous Technical Documents]

[0004] (Patent Documents)

[0005] Patent Document 1: Japanese Patent No. 4834056 Summary of the Invention

[0006] [The problem the invention aims to solve]

[0007] In such machine tools, due to years of deterioration and other reasons, the machining tools cannot be properly kept in the tool magazine, which can lead to machine tool malfunctions or damage. However, the proposal in Patent Document 1 does not specifically mention a solution to this problem.

[0008] The present invention was made in view of the above circumstances, and its object is to provide a detection device and method for poor tool retention of machine tools, which can effectively prevent the risk of machine tool failure or damage due to the inability of the machining tools in the tool magazine to be properly retained.

[0009] [Technical means to solve the problem]

[0010] (1) A tool retention failure detection device for a machine tool (e.g., machine tool 1 described later), wherein one of a plurality of machining tools (e.g., machining tools 6 described later) that are detachably held in a tool magazine (e.g., tool magazine 4 described later) is selectively mounted on a machining spindle (e.g., machining spindle 3 described later), wherein the tool magazine is provided with a plurality of tool holding mechanisms (e.g., tool holding mechanisms 8 described later); wherein the tool holding mechanism has: a pair of holding arms (e.g., a pair of holding arms 13a, 13b described later) extending from one end side (e.g., one end a side described later) to the other end side (e.g., the other end b side described later) and a tool holding part (e.g., tool holding part 14 described later) for holding the machining tool is provided at the aforementioned one end side; and a pair of fulcrums (e.g., a pair of fulcrums 16a, 16b described later) respectively provided at the aforementioned pair of holding arms. Along the extension direction of the holding arm; a force-applying component (e.g., force-applying component 17 described later) is provided between the holding arms at the other end of the aforementioned pair of holding arms, and applies force to the aforementioned tool holding portion in the tool holding direction via the aforementioned fulcrum; a locking component (e.g., locking component 18 described later) is fitted between the aforementioned pair of holding arms further to the other end than the location where the aforementioned force-applying component is provided, and moves relative to the aforementioned pair of holding arms between a locked position that maintains the aforementioned tool holding portion holding the processing tool and a release position that allows the displacement to be released; and a detection portion (e.g., detection portion 22 described later) moves integrally with the aforementioned locking component and its own position is detected by a predetermined detector (e.g., detector 25 described later); and when the position of the processing tool held by the aforementioned tool holding portion deviates from the normal held position, the aforementioned pair of holding arms prevent the aforementioned locking component from returning to the aforementioned locked position.

[0011] (2) The machine tool holding failure detection device according to (1) above, wherein the aforementioned detector, as a single detector shared by the respective detected parts of the aforementioned plurality of machine tool holding mechanisms, is fixed at a predetermined part of the aforementioned machine tool.

[0012] (3) The machine tool holding failure detection device according to (1) or (2) above, wherein each of the aforementioned pair of holding arms has a tool holding portion that is semi-circular in shape when viewed from the side (e.g., the holding portion 15 described later), the holding portion corresponding to the outer peripheral surface of the cylindrical portion in the aforementioned machining tool or the machining tool holding body integral with the machining tool.

[0013] (4) A tool retention failure detection device for a machine tool according to any one of (1) to (3) above, wherein the machine tool is operated under the control of a predetermined control unit (e.g., control unit 100 described later); the control unit monitors the detection output of the detector, and after issuing a control command to temporarily move the locking member to the aforementioned release position and then return it to the aforementioned locking position, if the aforementioned detection output indicating that the locking member has returned to the aforementioned locking position is not received within a predetermined time, the control unit issues a tool retention failure determination output for the machine tool.

[0014] (5) A method for detecting poor tool retention in a machine tool, wherein one of a plurality of machining tools (e.g., machining tools 6 described later) that are detachably held in a tool magazine (e.g., tool magazine 4 described later) is selectively mounted on a machining spindle (e.g., machining spindle 3 described later), wherein the tool magazine is provided with a plurality of tool holding mechanisms (e.g., tool holding mechanisms 8 described later); wherein the tool holding mechanism has: a pair of holding arms (e.g., a pair of holding arms 13a, 13b described later), extending from one end side (e.g., one end a side described later) to the other end side (e.g., the other end b side described later), and a tool holding part (e.g., a tool holding part described later) for holding the machining tool is provided at the aforementioned one end side. The tool holding part 14); a pair of fulcrums (e.g., a pair of fulcrums 16a, 16b described later) are respectively provided along the extension direction of the pair of holding arms; a force-applying member (e.g., a force-applying member 17 described later) is provided between the holding arms at the other end of the pair of holding arms, and applies force to the tool holding part in the tool holding direction via the fulcrums; a locking member (e.g., a locking member described later) is fitted between the pair of holding arms further to the other end than the location where the force-applying member is provided, and moves relative to the pair of holding arms between a locked position that maintains the tool holding part holding the machining tool and a released position that allows displacement to release the maintenance; the machine tool holding failure detection method includes: a positioning step (e.g., described later) Figure 8 Step S81), moving one of the aforementioned tool holding mechanisms in the aforementioned tool library to a position opposite to a machining tool; the locking release step (e.g., described later) Figure 8 Step S82), causing the aforementioned locking member to retract from the aforementioned locking position to the aforementioned releasing position; the holding step (e.g., described later) Figure 8 Step S83), which involves moving the aforementioned machining tool between the aforementioned tool grips of the respective pair of retaining arms; and the return step (e.g., described later). Figure 8 Step S84), returning the aforementioned locking component to the aforementioned locking position; and, determining the step (e.g., as described later). Figure 8In steps S85 and S86), if the detector does not issue a detection output indicating that the locking component has returned to the locking position within a predetermined time from the start of the aforementioned reset step, it is determined that the machining tool is not properly maintained.

[0015] (6) The machine tool holding failure detection method according to (5) above, wherein, in the aforementioned determination step, the position of the aforementioned locking component is detected by using a single aforementioned detector shared by multiple aforementioned tool holding mechanisms.

[0016] (7) A method for detecting the poor retention of machining tools of a machine tool according to (5) or (6) above, wherein, in the aforementioned determination step, a non-contact detector is used to detect the position of the aforementioned locking component.

[0017] (8) The machine tool tool retention defect detection method according to (7) above, wherein a magnetic sensor is used as the aforementioned non-contact detector.

[0018] (The effect of the invention)

[0019] In the machine tool retention failure detection device of (1), each of the multiple tool holding mechanisms in the tool magazine has a tool holding part that holds the tool at one end of a pair of holding arms. The tool holding part is always subjected to force by the force-applying member in the tool holding direction. In addition, when the locking member moves to the release position, the pair of holding arms overcome the force of the force-applying member and allow the tool holding part to release the displacement of the tool holding part from the tool. When the locking member returns to the locking position, the tool holding part maintains the grip of the tool on the tool. When the position of the tool held by the tool holding part deviates from the normal held position, the pair of holding arms prevent the locking member from returning to the locking position. Therefore, by detecting the position of the detected part that moves integrally with the locking member by the detector, the retention failure state of the tool in the tool holding mechanism is detected, which is a deviation from the normal held position.

[0020] In the tool retention failure detection device for the machine tool in (2), the detector that detects the position of the detected part that moves integrally with the locking component is fixed at a predetermined location on the machine tool as a single detector shared by the detected parts of multiple tool retention mechanisms. Therefore, the structure of the entire machine tool is simplified, and maintenance and management become easier.

[0021] In the machine tool retention failure detection device of (3), each tool holding portion of a pair of holding arms of multiple tool holding mechanisms has a gripping curved surface corresponding to the outer peripheral surface of the cylindrical portion in the tool holding body integrated with the tool. Therefore, when the tool is in a normal holding position relative to the tool holding mechanism, the tool can be reliably held between the tool holding portions of the pair of holding arms. Furthermore, when the relative position between the tool holding mechanism and the tool is in a tool retention failure state, the pair of holding arms in the tool holding mechanism prevents the locking member from returning to the locking position. Therefore, by detecting the displacement position of the locking member by a detector, a tool retention failure state can be detected.

[0022] In the tool retention failure detection device for the machine tool in (4), the control unit of the machine tool monitors the detection output of the detector. After issuing a control command to temporarily move the locking component to the release position and then return it to the locking position, if no detection output indicating that the locking component has returned to the locking position is received within a predetermined time, a tool retention failure judgment output is issued. Thus, taking into account the time required for the normal holding action of the tool to be held in the tool holding mechanism, an accurate tool retention failure judgment result can be obtained.

[0023] Regarding the method for detecting poor tool retention in machine tools (5), in the positioning step, a tool holding mechanism (its tool holding part) in the tool magazine is moved to a position opposite to a machining tool; in the locking release step, when the locking member is retracted from the locked position to the released position, the tool holding parts of the tool holding mechanism are allowed to open. In the subsequent holding step, a machining tool is moved between the tool holding parts of each of the pair of holding arms. In the return step, the locking member is returned to the locked position where the tool holding parts of the tool holding mechanism are closed. During this return, in the judgment step, if it is not detected that the locking member has returned to the locked position within a predetermined time from the start of the return step, it is judged that the machining tool retention is poor. Therefore, considering the time required for the normal holding action of the machining tool in the machining tool holding mechanism, an accurate judgment result of poor machining tool retention can be obtained.

[0024] Regarding the tool retention failure detection method for machine tools in (6), in the judgment step, a single detector shared by multiple tool retention mechanisms is used to detect the position of the locking component. Therefore, a smaller number of detectors is required, simplifying maintenance and management.

[0025] Regarding the machine tool retention defect detection method in (7), in the judgment step, a non-contact detector is used to detect the position of the locking component. Therefore, the maintenance and management around the detector becomes simple.

[0026] Regarding the method for detecting tool retention defects in machine tools (8), a magnetic sensor is used as a non-contact detector. This reduces the likelihood of detection errors caused by chips or coolant generated during cutting, resulting in accurate detection results. Attached Figure Description

[0027] Figure 1 This is a diagram illustrating a machine tool equipped with a tool retention failure detection device according to an embodiment of the present invention.

[0028] Figure 2 It is a drawing Figure 1 An enlarged view of a tool library in a machine tool.

[0029] Figure 3 It is a drawing Figure 2 An enlarged view of a machining tool holding mechanism in the tool library.

[0030] Figure 4 This is an explanation Figure 3 The diagram shows the structure and movement of the locking components in the machining tool holding mechanism.

[0031] Figure 5A This is an explanation Figure 3 A diagram showing the poor holding condition of the machining tool in the machining tool holding mechanism.

[0032] Figure 5B This is an explanation Figure 3 A diagram showing the normal holding state of the machining tool in the machining tool holding mechanism.

[0033] Figure 6 This is a diagram illustrating the structure around the detector in a machining tool retention defect detection device applied to a machine tool according to an embodiment of the present invention.

[0034] Figure 7 yes Figure 1 The functional block diagram of the control unit of the machine tool.

[0035] Figure 8 This is a flowchart illustrating a method for detecting poor tool retention in a machine tool according to an embodiment of the present invention.

[0036] Figure 9 This is a schematic diagram illustrating the main parts of a machine tool tool retention defect detection device according to another embodiment of the present invention. Detailed Implementation

[0037] Figure 1 This is a diagram illustrating a machine tool 1 equipped with a tool retention defect detection device according to an embodiment of the present invention. Figure 2 This is an enlarged view of a tool library within machine tool 1. Machine tool 1 has a structure in which a first machine tool 1L and a second machine tool 1R are mounted on a shared platform 2. The first machine tool 1L and the second machine tool 1R have similar structures. In the following description, unless otherwise specified, the first machine tool 1L and the second machine tool 1R will be referred to simply as machine tool 1. Machine tool 1 performs drilling, boring, honing, and other machining operations on workpieces (not shown) on the worktable 2. Machine tool 1 is centrally managed under the control of a control unit 100 equipped with a human-machine interface.

[0038] exist Figure 1 In this machine, as is commonly referred to in such machinery, let the axial direction of the machining spindle 3 be the Z direction. Within the Z direction, let the direction toward the workpiece be Z1, and its opposite direction be Z2. Let the left-right direction, orthogonal to the Z direction, be the X direction. Within the X direction, let the leftward direction, viewed from the X2 direction, be X1, and its opposite direction be X2. Let the direction orthogonal to both the Z and X directions be the Y direction. Within the Y direction, let upward be Y1, and its opposite direction be Y2.

[0039] In machine tool 1, one of several machining tools 6, which are detachably stored in tool magazine 4 and auxiliary tool magazine 5, is selectively and interchangeably mounted on machining spindle 3 for use. Figure 1 In this example, tool magazines 4 are respectively provided on the first machine tool 1L and the second machine tool 1R, and auxiliary tool magazine 5 is provided as a shared tool magazine for the first machine tool 1L and the second machine tool 1R. A machining spindle 3 is located at one end of a rotary arm 3a extending in a direction orthogonal to its axial direction, i.e., the Z-direction. The machining spindle 3 moves to a position facing the predetermined machining tool holding mechanism 8 in the tool magazine 4 by rotation of the rotary arm 3a, transferring machining tools 6 between the tool magazine 4 and the machining spindle 3. The auxiliary tool magazine 5 is configured to allow replacement of more tools than the number of machining tools that can be held in the tool magazine 4 relative to the first machine tool 1L and the second machine tool 1R.

[0040] Reference Figure 2As can be seen, the tool magazine 4 has multiple tool holding mechanisms 8 for holding machining tools 6 arranged at approximately equal intervals in the circumferential direction on the outer periphery of the disk-shaped support body 7, which has a disk-shaped envelope. In this example, the support body 7 is configured such that a central rotating shaft portion 9 and two outer ring-shaped components with different diameters, namely a first ring-shaped component 10 and a second ring-shaped component 11, are connected by spoke components. The second ring-shaped component 11 is located on the outer periphery of the first ring-shaped component 10. All of the multiple tool holding mechanisms 8 have similar structures. The cutting tool 6a on the front end side of the machining tool 6 is integrally fitted onto the cylindrical tool holding body 6b on the base side, and the rear end side of the tool holding body 6b forms a generally cylindrical mounting portion 6c that is mounted on the machining spindle 3.

[0041] Next, refer to Figure 3 The tool holding mechanism 8 is described below. Figure 3 It is a drawing Figure 2 An enlarged view of a machining tool holding mechanism 8 in tool library 4. The machining tool holding mechanism 8 has a pair of holding arms 13a, 13b, which extend from one end a to the other end b and face each other in a direction intersecting the direction from one end a to the other end b. Between the pair of holding arms 13a, 13b, there is a square-bar-shaped key member 13k extending along their extending direction. The pair of holding arms 13a, 13b are structured to face each other and form a mirror image; therefore, this pair of holding arms 13a, 13b is appropriately referred to collectively as holding arms 13. At one end a, a tool gripping portion 14 is provided on the holding arm 13. The tool gripping portion 14 has a gripping curved surface 15 corresponding to the outer peripheral surface of the machining tool 6 (its cylindrical machining tool holder 6b). On the other hand, keyways 6k are formed at two symmetrical locations about the axis on the peripheral surface of the machining tool holder 6b. The keyway 6k is a recess corresponding to the front end of the key component 13k in the radial direction. When the machining tool holder 6b is in the normal rotational phase position, the key component 13k is engaged.

[0042] Therefore, when the machining tool 6 (its cylindrical machining tool holder 6b) is in its normal held position relative to the machining tool holding mechanism 8, the outer periphery of the machining tool 6 (its cylindrical machining tool holder 6b) can be reliably held without clearance between the tool grips 14 of the pair of holding arms 13a, 13b. Furthermore, when the relative position of the machining tool holding mechanism 8 and the machining tool 6 (its cylindrical machining tool holder 6b) is in a poor machining tool holding state, the pair of holding arms 13a, 13b in the machining tool holding mechanism 8 prevents the locking member 18 from returning to the locked position. Therefore, by detecting the displacement position of the holding arms using a detector, a poor machining tool holding state can be reliably detected.

[0043] A pair of retaining arms 13a and 13b, extending from one end a to the other end b, are rotatably supported on the second annular member 11 of the tool magazine 4 as pivots functioning as a pair of fulcrums 16a and 16b. The pair of fulcrums 16a and 16b are appropriately referred to as fulcrums 16. A force-applying member 17 is provided between the retaining arms 13 at the other end b of the pair of retaining arms 13a and 13b, applying force to the tool gripping portion 14 in the tool gripping direction via the fulcrums 16. The tool gripping direction refers to the direction in which the opposing gripping curved surfaces 15 of each of the pair of retaining arms 13a and 13b approach each other. The force-applying member 17 is a coil spring, applying force in a direction that separates the coil spring abutment portions at the other end b of the pair of retaining arms 13a and 13b from each other.

[0044] A shaft-shaped locking member 18 extending in the Z direction is fitted between the portions of a pair of retaining arms 13a and 13b that are further from the other end b than the portion where the helical spring abuts the force-applying member 17 is located. The circumferential surface of the locking member 18 abuts against the pair of retaining arms 13a and 13b, and moves axially, i.e., in the Z direction, relative to the pair of retaining arms 13a and 13b between the locked position where the tool holding portion 14 holds the machining tool 6 (its cylindrical machining tool holder 6b) and the release position where displacement is allowed to release the holding. The locking member 18 is axially slidably supported on the first annular member 10 of the tool magazine 4.

[0045] Next, refer to Figure 4 Details of the area surrounding the locking component 18 are described below. Figure 4 This is a view of the locking component 18 from the other end b side of the pair of retaining arms 13a, 13b. Figure 4 Part (A) shows the locking member 18 in the aforementioned locking position. Figure 4 Section (B) shows the locking component 18 in the aforementioned released position. Figure 4Section (C) shows that the locking component 18 is temporarily moved to Figure 4 The state shown in section (B) is that the lock position was not returned after the release position.

[0046] The shaft-shaped locking member 18 has: a larger diameter head 19 as a short cylindrical portion at one end (Z direction Z1 side); a smaller diameter small-diameter shaft portion 20 extending axially from the head 19 to the other end; and a tapered portion 21 that gradually tapers from the head 19 towards the small-diameter shaft portion 20. A generally disc-shaped member, the detection portion 22, slightly larger in diameter than the head 19, is concentrically fixed to the end side of the small-diameter shaft portion 20 of the locking member 18. The detection portion 22 is a stop for detecting the axial displacement position of the locking member 18 by means of a detection unit described later.

[0047] The return force-applying component, namely the helical spring 23, is coaxially fitted with the small-diameter shaft portion 20 between the detected portion 22 and the opposing surfaces of the first annular component 10. That is, the detected portion 22 also functions as a reaction force-bearing component that withstands the force generated by the helical spring 23. The helical spring 23, via the reaction force-bearing component, namely the detected portion 22, continuously applies a force to the locking component 18 in the direction of returning to the aforementioned locked position.

[0048] When the pair of retaining arms 13a, 13b hold the machining tool 6 in its normal holding state using the tool gripping parts 14, the gap at the b-side of the ends of the retaining arms 13a, 13b opens. Therefore, the head of the locking member 18, by the force of the coil spring 23, such as... Figure 4 As shown in section (A), the arms 13a and 13b are inserted between each other, preventing the ends b sides of the pair of arms 13a and 13b from approaching each other. This maintains the tool gripping portion 14 of the pair of arms 13a and 13b in a holding state of the machining tool 6.

[0049] On the other hand, the machine tool 1, at a predetermined location, includes a release lever 24 that moves the locking member 18 axially from the locked position toward the released position. When the tool magazine 4 reaches a predetermined rotational phase position for transferring the machining tool 6 to the machining spindle 3, the end of the release lever 24 is coaxially opposite to the end of the small-diameter shaft portion 20 of the locking member 18. In this state, under the control of a predetermined servo mechanism responding to a servo command from the control unit 100 in the machine tool 1, the release lever 24 advances and presses against the end of the small-diameter shaft portion 20. Therefore, the locking member 18 moves axially toward... Figure 4 The release position shown in (B) has shifted.

[0050] With the locking member 18 in the released position, the small-diameter shaft portion 20 of the locking member 18 is clamped at a distance from the pair of retaining arms 13a, 13b at the other end b. This allows displacement of the other end b of the pair of retaining arms 13a, 13b in a direction where the distance between them narrows. As a result, the tool gripping portion 14 at one end a of the pair of retaining arms 13a, 13b is allowed to rotate about the fulcrum 16a, 16b and is allowed to displace in a direction where the distance between them increases. That is, the holding state of the machining tool 6 is released, or displacement is allowed for receiving the machining tool 6 to be replaced.

[0051] In this state, when the machining tool 6 is transferred by the tool holder 14, the release lever 24 retracts under the control of the aforementioned servo mechanism, moving away from the end of the small-diameter shaft portion 20 of the locking member 18. As the release lever 24 retracts, the locking member 18 attempts to displace and return to its original position by means of the force of the coil spring 23. Figure 4 The locking state shown in part (A).

[0052] In cases where the position of the machining tool 6 held by the tool holder 14 deviates from its normal held position, the gap between the pair of holding arms 13a and 13b at their other ends (b-side) cannot be opened to the outer diameter of the head 19 of the locking member 18. This prevents the locking member 18 from returning to the locked position. Therefore, as... Figure 4 As shown in section (C), the head 19 of the locking member 18 cannot enter between the other ends b of the pair of retaining arms 13a, 13b and remains there.

[0053] Simultaneously refer to Figure 5A For arrival Figure 4 The phenomenon of the state of part (C) will be explained. Figure 5A This diagram illustrates the improper holding state of the machining tool 6 in the machining tool holding mechanism 8. When one of the machining tool holding mechanisms 8 in the tool magazine 4 reaches a phase position with the machining spindle 3 to transfer the machining tool 6 in the machine tool 1 by a predetermined servo mechanism responding to a servo command from the control unit 100, the locking member 18 retracts to... Figure 4 The release position is shown in section (B). In this state, the machining tool 6, which moves from the machining spindle 3 to the machining tool holding mechanism 8, attempts to push the pair of holding arms 13a, 13b apart towards the tool holding part 14 using its cylindrical machining tool holder 6b, and is held by the holding curved surface 15.

[0054] As the machining tool 6 moves toward the machining tool holding mechanism 8, a pair of holding arms 13a and 13b displace in opposite directions around their fulcrums 16a and 16b, respectively, toward one end a and the other end b. At this time, the force applied by the force-applying member 17 exerts a force on one end a of the pair of holding arms 13a and 13b in the direction of closing between them. Therefore, the machining tool holding body 6b of the machining tool 6 overcomes this force, temporarily pushing the pair of holding arms 13a and 13b apart and moving them to a position where they are held by the gripping curved surface 15 of the tool gripping parts 14, and the pair of holding arms 13a and 13b are closed by the aforementioned force.

[0055] on the other hand, Figure 5B This diagram illustrates the normal holding state of the machining tool 6 within the machining tool holding mechanism 8. When the machining tool holder 6b of the machining tool 6 reaches its normal rotation phase, the key member 13k engages in the keyway 6k. Thus, the machining tool 6 is held in its normal holding state by the tool grip 14. Upon reaching this state, one end (a) of the pair of holding arms 13a, 13b closes to a predetermined interval, resulting in the other end (b) returning to a position where the head 19 of the locking member 18 can enter. Figure 4 The state shown in part (A). However, as Figure 5A As shown, if the tool holder 6b of the machining tool 6 is not in the normal rotation phase, the key member 13k cannot be engaged in the keyway 6k. In this state, the peripheral surface of the tool holder 6b of the machining tool 6 is pressed downward by the key member 13k, causing the retaining arm 13 to be held in the normal position, thus being held to the point where it will not fall. That is, it is not held in the normal holding state by the tool grip 14, and the machining tool 6 remains in a position where the outer peripheral surface of the tool holder 6b does not fit the gripping curved surface 15 of the tool grip 14, making it impossible for the locking member 18 to return to its original position. Figure 4 The abnormal state shown in section (C).

[0056] That is, the gap at one end (a) of the pair of retaining arms 13a, 13b remains in a more open state than in the normal retaining position, resulting in the gap at the other end (b) of the pair of retaining arms 13a, 13b remaining in a narrower state than in the normal position. In this state, as described above, the locking member 18 cannot return to its original position. Figure 4 The state shown in part (A) remains unchanged. Figure 4 The location of the abnormal state is shown in section (C).

[0057] Specifically, focusing on the transfer of the machining tool 6 within the pair of holding arms 13a, 13b and the operation of the locking member 18, when the position of the machining tool 6 held by the tool gripping part 14 deviates from its normal held position, the pair of holding arms 13a, 13b prevents the locking member 18 from returning to the aforementioned locked position. For example... Figure 5A and Figure 4 The state shown in section (C) represents the state in which this obstacle occurs.

[0058] In the apparatus of this embodiment, detector 25 is used to detect... Figure 4 The axial displacement position of the locking member 18 in the state shown in section (C) is used to determine if the machining tool is not properly held. (Refer to...) Figure 6 The structure surrounding detector 25 is described.

[0059] Figure 6 This is a diagram illustrating the structure around the detector 25 in a tool retention failure detection device for a machine tool according to an embodiment of the present invention. (See reference...) Figure 4 As illustrated in Figure 5, the axial displacement position of the locking member 18 is used to detect whether the machining tool 6 (machining tool holder 6b) is properly held in the machining tool holding mechanism 8. The control unit 100 identifies the axial displacement position of the locking member 18 based on the detection output of the detector 25, wherein the detector 25 corresponds to the position of the stop of the detected part 22, which moves integrally with the locking member 18.

[0060] The detector 25 is located in the three-dimensional region of the locking position, i.e., the detection region, in the axial displacement position of the locking component 18. In the tool magazine 4, multiple machining tool holding mechanisms 8 are arranged radially at intervals along its circumference, and respectively transfer machining tools 6 (machining tool holders 6b) with the machining spindle 3 at predetermined rotational phase positions, i.e., transfer positions of the tool magazine 4.

[0061] The detector 25, which detects the position of the detected part 22 at a detection area at each common transfer position in the multiple tool holding mechanisms 8, is fixed at a predetermined location on the machine tool 1 as a single detector 25 shared by the detected parts 22 of each of the multiple tool holding mechanisms 8. Therefore, the machine tool 1 does not have many detectors, thus simplifying the overall structure and maintenance.

[0062] exist Figure 6 In the example, the release lever 24 retracts from the position of the end of the small-diameter shaft 20 of the locking member 18, and the head 19 of the locking member 18 reaches the position by the force of the coil spring 23. Figure 4The detector 25 is positioned corresponding to the displacement position of the detected part 22 in the state shown in section (A). That is, the detector 25 is fixed by the support member 26 such that the probe faces the portion of the detection area that faces the outer periphery of the detected part 22.

[0063] In this case, the support member 26 is a plate-shaped member mounted on the opposing surface of the small-diameter shaft portion 20 of the locking member 18 within the housing 27 of the release lever 24. The support member 26 is mounted on a front portion of the housing 27 orthogonal to the release lever 24. The support member 26 extends outward from the housing 27 in the direction along this front portion to a predetermined outer position, and from this outer position is bent at approximately a right angle parallel to the small-diameter shaft portion 20 of the locking member 18, holding the detector 25 at a position extending a predetermined dimension from this bent portion such that its probe can face the outer periphery of the detected portion 22. Figure 6 From this perspective, the support component 26 is roughly L-shaped. The detector 25 is a non-contact detector, also known as a magnetic detector. Therefore, the maintenance and management around the detector 25 is easy, and furthermore, it is less prone to detection errors caused by chips generated during cutting or coolant used in cutting, thus enabling accurate detection results.

[0064] The detection output of detector 25 is provided to the control unit 100 of machine tool 1, where it is determined whether the machining tool is in a good working condition. Next, refer to... Figure 7 and Figure 8 The determination method is explained.

[0065] Figure 7 This is a functional block diagram of the control unit 100 of the machine tool 1, especially a functional block diagram related to the transfer of the machining tool 6 in the machining tool holding mechanism 8 and the determination of whether the machining tool holding state is good. Figure 8 This is a flowchart illustrating a method for detecting poor tool retention in a machine tool according to an embodiment of the present invention, particularly a flowchart related to the transfer of the tool 6 in the tool holding mechanism 8 and the method for determining whether the tool retention state is good.

[0066] exist Figure 7In this system, the control unit 100 is configured to include a rotary arm control unit 101, a tool magazine control unit 102, a release lever control unit 103, a detection output recognition unit 104, a holding state determination unit 105, a servo command output unit 106, a display control unit 107, and a management unit 108. The control unit 100 issues various servo commands SC related to workpiece machining or tool changing to operate the corresponding servo mechanisms of the machine tool 1. Additionally, the control unit 100 issues display commands DC to display the data on a predetermined display unit. Furthermore, the control unit 100 receives feedback signals FS from the servo mechanisms responding to the servo commands SC. It also receives detection signals DS from the detector 25.

[0067] The rotary arm control unit 101, tool magazine control unit 102, and release lever control unit 103 provide servo commands SC to their respective servo mechanisms in the machine tool 1 via the servo command output unit 106, enabling them to execute actions according to a predetermined program. The detection output recognition unit 104 recognizes the detection signal DS received from the detector 25. The holding state determination unit 105 determines whether the holding state of the machining tool 6 in the machining tool holding mechanism 8 is good based on the recognition status of the detection signal DS in the detection output recognition unit 104. The management unit 108 recognizes the states of the rotary arm control unit 101, tool magazine control unit 102, release lever control unit 103, detection output recognition unit 104, holding state determination unit 105, servo command output unit 106, and display control unit 107, enabling the necessary cooperation between them and performing unified management. The management unit 108 also has functional units related to the human-machine interface for the operator.

[0068] Next, refer to Figure 8 The flowchart describes the transfer of the machining tool 6 in the machining tool holding mechanism 8 under the management of the control unit 100 and the determination of whether the machining tool holding state is good. The tool magazine control unit 102 controls the servo mechanism for rotating the tool magazine 4 according to the servo command SC, causing the tool magazine 4 to rotate, and moving one of the tool holding mechanisms 8 in the tool magazine 4 to a position opposite to a machining tool 6 (machining tool holder 6b) and positioning it (step S81). Step S81 corresponds to the positioning step in the method of this embodiment.

[0069] Next, the release lever control unit 103 controls the servo mechanism that drives the release lever 24 according to the servo command SC, causing the release lever 24 to move forward and the locking member 18 to retract from the locked position to the released position, thus entering the lock-released state (step S82). Step S82 corresponds to the lock-release step in the method of this embodiment.

[0070] Next, the rotary arm control unit 101 controls the servo mechanism for rotating the rotary arm 3a according to the servo command SC, causing the machining spindle 3 to move, and a machining tool 6 (machining tool holder 6b) mounted at its front end enters between the tool holding portions 14 of a pair of holding arms 13a, 13b (step S83). Thus, when the machining tool 6 is in its normal holding state, the opposing tool holding portions 14 are temporarily pushed apart by the passage of the circumferential surface of the machining tool holder 6b, and then closed under the force of the force-applying member 17 to hold the machining tool 6 (machining tool holder 6b). At this time, the circumferential surface of the machining tool 6 (machining tool holder 6b) abuts against the holding curved surface 15 of the tool holding portion 14 with approximately no gap. Step S83 corresponds to the holding step in the method of this embodiment.

[0071] Next, the release lever control unit 103 issues a servo command SC (step S84) to the servo mechanism that drives the release lever 24 to retract the release lever 24 and return the locking member 18 from the locked position to the released position. Step S84 corresponds to the return step in the method of this embodiment.

[0072] Therefore, the release lever 24 returns from its forward position to its retracted position towards the housing 27. That is, the locking member 18 becomes capable of allowing the release lever 24 to disengage and return to its original position. Figure 4 The state of the locking position shown in section (A) is a conditional state. Even when the machining tool 6 is in the normal held state, a predetermined time is required for movement until the locking member 18 returns to the locking position. When the locking member 18 has returned to the locking position, the peripheral portion of the detection part 22, which moves integrally with the locking member 18, reaches... Figure 6 The probe tip of the detector 25 is in a proximity position. In this state, the detector 25, acting as a proximity switch, emits a detection output. The state determination unit 105 monitors whether the detection output from the detector 25 is received within the predetermined time (step S85).

[0073] In step S85, if the detector output of the detector 25 is received within a predetermined time (step S85: "Yes"), it means that the locking component 18 has returned to normal. Figure 4 The locking position is shown in section (A). That is, the machining tool 6 in the tool holding part 14 of the machining tool holding mechanism 8 is held in a normal holding state. In this state, since the machine tool 1 continues to operate without obstruction, the machining tool holding failure detection and processing ends.

[0074] On the other hand, if the status determination unit 105 does not receive the detection output from the detector 25 within a predetermined time (step S85: "No"), it determines that the machining tool is not properly held. The display control unit 107 sends a display command DC to a predetermined display unit and displays the determination result. Furthermore, the management unit 108 issues a servo command SC to temporarily stop the machine tool 1 (step S86). This allows the operator of the machine tool 1 to take necessary measures. Thus, problems such as machine tool malfunction or damage caused by the machining tool 6 not being properly held in the tool magazine 4 are avoided. Steps S85 and S86 correspond to the determination steps in the method of this embodiment.

[0075] Figure 9 This is a schematic diagram illustrating the main parts of a machine tool tool retention failure detection device according to another embodiment of the present invention. Figure 9 In the implementation method, the passive rod 18a is used instead of the reference rod. Figure 4 and Figure 6 The locking component 18 is described. Other structures and references. Figures 1 to 8 The machine tool described is similar to 1. In Figure 9 In, with Figure 4 and Figure 6 The corresponding parts are indicated by the same reference numerals. Furthermore, the diagram of the return force-applying component (coil spring) coaxially mounted on the small-diameter shaft 20 is omitted in this schematic diagram.

[0076] Passive rod 18a, which is related to the reference rod Figure 4 and Figure 6 The entire portion corresponding to the head 19 and the tapered portion 21 in the described locking member 18 forms the tapered portion 21a. In other words, without the head 19 in the locking member 18, a partially tapered body is formed at one end of the small-diameter shaft portion 20, which expands towards that end. In addition, on the portion facing the partially tapered body at the other end b of the pair of retaining arms 13a, 13b of the machining tool holding mechanism 8, an inclined surface 28 is formed along the circumferential surface of the partially tapered body.

[0077] In Figure 4 The (A) part corresponds to Figure 9 In the state of part (A), the machining tool 6 is held in a normal holding state on one end a side of the pair of holding arms 13a, 13b of the machining tool holding mechanism 8. In this state, the distance between the other ends b side of the pair of holding arms 13a, 13b is relatively widened. Therefore, the tapered portion 21a of the driven rod 18a enters relatively deeply between the two inclined surfaces 28 and displaces towards the other end side having the detection portion 22. Figure 6 As shown, the detector 25 detects the position of the detected part 22 at the displacement position and confirms that the machining tool 6 is held in a normal holding state.

[0078] In Figure 4 The (C) part corresponds to Figure 9 In the state of part (B), the machining tool 6 is not held in its normal holding state at one end a of the pair of holding arms 13a, 13b of the machining tool holding mechanism 8, but exhibits a poor holding state. In this state, the gap between the other ends b of the pair of holding arms 13a, 13b remains relatively narrow. Therefore, the tapered portion 21a of the driven rod 18a cannot penetrate deeply between the two inclined surfaces 28 and cannot displace towards the other end with the detection portion 22. Figure 6 The detector 25 is used to detect the position of the detected part 22 at the displacement position, thereby determining that the machining tool 6 is in a poor holding state.

[0079] The machine tool tool retention defect detection device and method according to this embodiment achieve the following effects.

[0080] In the machine tool tool retention failure detection device of (1), each of the multiple tool holding mechanisms 8 in the tool magazine 4 has a tool holding part 14 for holding the tool 6 (tool holding body 6b) at one end a of a pair of holding arms 13a, 13b. The tool holding part 14 is always subjected to force by the force applying member 17 in the tool holding direction (the direction in which the tool holding parts 14 are closed). In addition, when the locking member 18 moves to the released position, the pair of holding arms 13a, 13b overcomes the force of the force applying member 17 and allows the displacement of the tool holding part 14 in holding the tool 6 (tool holding body 6b) to be released. When the locking member 18 returns to the locked position, the tool holding part 14 maintains the holding of the tool 6 (tool holding body 6b). When the position of the machining tool 6 (machining tool holder 6b) held by the tool holding part 14 deviates from the normal held position, a pair of holding arms 13a, 13b prevent the locking member 18 from returning to the locked position (Fig. 5). Therefore, by detecting the position of the detected part 22, which moves integrally with the locking member 18, by the detector 25, it is detected that the position of the machining tool 6 (machining tool holder 6b) in the machining tool holding mechanism 8 is in a poor holding state that deviates from the normal held position.

[0081] In the tool retention failure detection device of the machine tool in (2), the detector 25, which detects the position of the detected part 22 that moves integrally with the locking member 18, is a single detector 25 shared by the detected parts 22 of the multiple tool retention mechanisms 8, and is fixed at a predetermined position on the machine tool 1. Therefore, without multiple detectors, the structure of the entire machine tool 1 is simplified, and maintenance and management become simple.

[0082] In the machine tool retention failure detection device of (3), each tool holding portion 14 of a pair of holding arms 13a, 13b of each of the plurality of tool holding mechanisms 8 has a gripping curved surface 15 corresponding to the outer peripheral surface of the cylindrical portion in the tool 6 or the tool holding body 6b integral with the tool. Therefore, when the relative position of the tool 6 (tool holding body 6b) with respect to the tool holding mechanism 8 is in the normal held position, the tool 6 (tool holding body 6b) can be reliably held between the tool holding portions 14 of the pair of holding arms 13a, 13b. Furthermore, when the relative position between the tool holding mechanism 8 and the tool 6 (tool holding body 6b) is in a tool retention failure state, the pair of holding arms 13a, 13b in the tool holding mechanism 8 prevents the locking member 18 from returning to the locked position. Therefore, by detecting the displacement position of the locking member 18 by the detector 25, a tool retention failure state can be detected.

[0083] In the tool retention failure detection device of the machine tool in (4), the control unit 100 of the machine tool 1 monitors the detection output of the detector 25. After issuing a control command to temporarily move the locking member 18 to the release position and then return it to the locking position, if no detection output indicating that the locking member 18 has returned to the locking position is received within a predetermined time, a tool retention failure judgment output for the tool 6 (tool holder 6b) is issued. Thus, taking into account the time required for the normal holding operation of the tool 6 (tool holder 6b) in the tool holding mechanism 8, an accurate tool retention failure judgment result can be obtained.

[0084] Regarding the machine tool tool retention defect detection method for (5), in the positioning step ( Figure 8 In step S81), one of the tool holding mechanisms 8 (its tool holding part 14) in the tool magazine 4 is moved to a position opposite to a machining tool 6 (machining tool holder 6b); in the locking release step ( Figure 8 In step S82), when the locking member 18 is retracted from the locked position to the released position, the tool gripping portion 14 of the tool gripping mechanism 8 is allowed to open. In subsequent gripping steps ( Figure 8 In step S83), a machining tool 6 (machining tool holder 6b) is brought between the tool holding portions 14 of each of the pair of holding arms 13a, 13b. In the return step ( Figure 8 In step S84), the locking member 18 is returned to the locked position where the tool gripping portion 14 of the tool gripping mechanism 8 is closed. During this return, in the determination step (… Figure 8In steps S85 and S86), if no locking component is detected to have returned to the locking position within a predetermined time from the start of the reset step, it is determined that the machining tool is not properly held. Therefore, considering the time required for the machining tool to be held to perform its normal holding action in the machining tool holding mechanism 8, an accurate result for determining whether the machining tool is not properly held can be obtained.

[0085] Regarding the machine tool retention defect detection method for (6), in the judgment step ( Figure 8 In steps S85 and S86, a single detector 25 shared by multiple machining tools is used to detect the position of the locking component 18. Therefore, the number of detectors 25 is small, simplifying maintenance and management.

[0086] Regarding the machine tool tool retention defect detection method for (7), in the judgment step ( Figure 8 In steps S85 and S86, the position of the locking component 18 is detected using a non-contact detector 25. Therefore, maintenance and management of the area surrounding the detector 25 becomes simple.

[0087] Regarding the method for detecting tool retention defects in machine tools (8), a magnetic sensor is used as a non-contact detector 25. As a result, detection errors caused by chips generated during cutting or coolant used in cutting are less likely to occur, and accurate detection results can be obtained.

[0088] The embodiments of the present invention have been described above, but the present invention is not limited thereto. The detailed structure can be appropriately modified within the scope of the spirit of the present invention. For example, in the above embodiments, the locking member 18 or the passive rod 18a is an axial body extending parallel to the fulcrum 16a, 16b of the retaining arms 13a, 13b, i.e., the support shaft, and its axial displacement position is detected by the detector 25. However, an alternative structure can be used. That is, it can also be configured such that the passive member, whose displacement between the opposing surfaces changes according to the interval between the opposing surfaces on the other end b side of the retaining arms 13a, 13b, is movably provided from the other end b side of the retaining arms 13a, 13b in their extending direction, and the displacement position of such a passive member is detected by a non-contact detector.

[0089] Figure Labels

[0090] a one end

[0091] b The other end

[0092] DC Display Commands

[0093] DS detection signal

[0094] FS feedback signal

[0095] SC Servo Command

[0096] 1 Machine tool

[0097] 1L First Machine Tool

[0098] 1R Second Machine Tool

[0099] 2 platforms

[0100] 2a Workbench

[0101] 3. Machining the spindle

[0102] 3a Rotary Arm

[0103] 4. Tool Library

[0104] 5. Auxiliary Tool Library

[0105] 6. Machining tools

[0106] 6a Cutting tools

[0107] 6b Machining tool holder

[0108] 6c Installed part

[0109] 6K keyway

[0110] 7. Support

[0111] 8. Machining tool holding mechanism

[0112] 9. Rotating shaft

[0113] 10 First annular component

[0114] 11 Second ring-shaped component

[0115] 12-spoke assembly

[0116] 13, 13a, 13b Holding arms

[0117] 13k key components

[0118] 14 Tool Holding Section

[0119] 15. Hold with curved surface

[0120] 16, 16a, 16b Pivot points (axis supports)

[0121] 17 Force-applying components

[0122] 18 Locking components

[0123] 18a Passive Rod

[0124] 19 Head

[0125] 20 Small diameter shaft

[0126] 21,21a Conical part

[0127] 22. Departments under inspection

[0128] 23. Coil spring

[0129] 24 Release lever

[0130] 25 detectors

[0131] 26 Support components

[0132] 27. Housing

[0133] 28 Inclined surface

[0134] 100 Control Department

[0135] 101 Rotary Arm Control Unit

[0136] 102 Tool Library Control Department

[0137] 103 Release lever control unit

[0138] 104 Detection Output Recognition Unit

[0139] 105 Status Determination Unit

[0140] 106 Servo Command Output Unit

[0141] 107 Display Control Unit

[0142] 108 Management Department

Claims

1. A tool retention failure detection device for a machine tool, wherein one of a plurality of tools detachably held in a tool magazine is selectively and replaceably mounted on a machining spindle for use. The aforementioned tool library has multiple tool holding mechanisms for holding the machining tools; The aforementioned tool holding mechanism has: A pair of retaining arms extend from one end to the other end and a tool holding part for holding the processing tool is provided on the aforementioned one end; A pair of fulcrums are respectively set along the extension direction of the aforementioned pair of retaining arms; The force-applying component is disposed between the retaining arms at the other end of the aforementioned pair of retaining arms, and applies force to the aforementioned tool holding portion in the tool holding direction via the aforementioned fulcrum; A locking member is fitted between the pair of retaining arms located further away from the position where the aforementioned force-applying member is located, on the opposite side of the aforementioned pair of retaining arms, and moves relative to the aforementioned pair of retaining arms between a locked position that maintains the aforementioned tool gripping portion holding the machining tool and a released position that allows displacement to release the maintenance; and, The detected part moves integrally with the aforementioned locking component and its position is detected by a predetermined detector; The aforementioned machining tool has a machining tool holder, and keyways are formed at two symmetrical locations about the axis on the circumferential surface of the aforementioned machining tool holder. Furthermore, the aforementioned pair of retaining arms have a key member extending along the extension direction of the aforementioned pair of retaining arms between the aforementioned pair of retaining arms. When the aforementioned machining tool holder is in the normal rotational phase position, the aforementioned key member is fitted into the aforementioned keyway. When the position of the machining tool held by the aforementioned tool holding part deviates from the normal held position, the aforementioned pair of retaining arms prevent the aforementioned locking member from returning to the aforementioned locking position.

2. The machine tool tool retention defect detection device according to claim 1, wherein, The aforementioned detector, which serves as a single detector shared by the respective detected parts of the aforementioned multiple machining tool holding mechanisms, is fixed at a predetermined location on the aforementioned machine tool.

3. The machine tool tool retention defect detection device according to claim 1, wherein, Each of the aforementioned pair of holding arms has a tool gripping portion with a gripping curved surface, which corresponds to the outer peripheral surface of the cylindrical portion in the aforementioned processing tool or the processing tool holder integral with the processing tool.

4. The machine tool tool retention defect detection device according to claim 1, wherein, The aforementioned machine tool operates under the control of a predetermined control unit; The aforementioned control unit monitors the detection output of the aforementioned detector. After issuing a control command to temporarily move the aforementioned locking component to the aforementioned release position and then return it to the aforementioned locking position, if the aforementioned detection output indicating that the aforementioned locking component has returned to the aforementioned locking position is not received within a predetermined time, the control unit issues a machining tool holding failure judgment output for the machining tool.

5. A method for detecting poor tool retention in a machine tool, comprising selectively and replaceably mounting one of a plurality of tools held in a tool magazine on a machining spindle for use, wherein the tool magazine is provided with a plurality of tool holding mechanisms for holding the tool; the tool holding mechanism comprising: a pair of holding arms extending from one end to the other end and having a tool holding portion for holding the tool at the aforementioned one end; a pair of fulcrums respectively disposed along the extension direction of the aforementioned pair of holding arms; a force applying member disposed between the holding arms at the other end of the aforementioned pair of holding arms, applying force to the tool holding portion in the tool holding direction via the aforementioned fulcrums; and a locking member, which is engaged with the tool holding portion. The tool is mounted between a pair of retaining arms located further away from the location where the force-applying component is located, and moves relative to the pair of retaining arms between a locked position where the tool holding part holds the machining tool and a released position where displacement allows the release of the holding. The machining tool has a tool holder, and keyways are formed at two symmetrical locations about an axis on the circumferential surface of the tool holder. Furthermore, the pair of retaining arms has a key member extending along the extending direction of the pair of retaining arms between them. When the tool holder is in its normal rotational phase position, the key member engages with the keyway. The method for detecting poor tool holding in a machine tool includes: The positioning step moves one of the tool holding mechanisms in the aforementioned tool library to a position opposite to a machining tool; The locking release step involves retracting the aforementioned locking component from the aforementioned locking position to the aforementioned release position; The holding step involves moving the aforementioned machining tool between the aforementioned tool holding portions of each of the aforementioned pair of holding arms; The reset step returns the aforementioned locking component to the aforementioned locking position; and, In the determination step, if the detector does not issue a detection output indicating that the locking component has returned to the locking position within a predetermined time after the start of the aforementioned reset step, it is determined that the machining tool is not properly maintained.

6. The method for detecting poor tool retention in machine tools according to claim 5, wherein, In the aforementioned determination step, the position of the aforementioned locking component is detected by using a single aforementioned detector shared by multiple aforementioned processing tools and the mechanism.

7. The method for detecting poor tool retention in machine tools according to claim 5, wherein, In the aforementioned determination step, a non-contact detector is used to detect the position of the aforementioned locking component.

8. The method for detecting poor tool retention in a machine tool according to claim 7, wherein, A magnetic sensor is used as the aforementioned non-contact detector.

Images