KR20180008177A - Automatic tool changer and method of changing tools using the same - Google Patents

Abstract

Disclosed is an automatic tool change device for a numerical value control machine tool. The automatic tool change device comprises: a tool change arm for performing rotational movement and linear movement according to a tool change signal, and changing a tool between a tool magazine and a spindle; a cam assembly for driving the tool change arm according to a displacement diagram of a cam structure; a driver for providing driving force for rotating the cam structure; and a tool change controller including an encoder for detecting a position of the tool change arm in real time and a failure recovery unit for automatically determining a return direction of the tool change arm depending on a failure position of the tool change arm detected by the encoder if a driving failure of the tool change arm occurs and for returning the tool change arm to a home position in the return direction to recover the tool change arm to a tool change initial state. According to the present invention, a driving failure of the automatic tool change device can be automatically mitigated.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tool changer,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tool changer (ATC) and an automatic tool changer using the same. More particularly, the present invention relates to an automatic tool changer for a machining center and an automatic tool changer using the automatic tool changer.

Numerical control machining (CNC) machines, which can automatically control machining processes with numerical control algorithms, are required to be produced in large quantities with high precision for workpieces of various shapes and sizes, from large structures to fine parts Tool) is increasing.

In recent numerical control machine tools, a tool changer (automatic tool changer, ATC) or an attachment corresponding to the tool can be automatically replaced Such as an automatic attachment changer (AAC), as a machining center for controlling the processing machine and ancillary equipment by a controller. Therefore, in the machining center, various machining is performed by automatically performing multi-axis machining or multi-step machining according to the input design data.

The automatic tool changer (ATC) automatically exchanges tools from a plurality of tools disposed in a tool magazine in accordance with the machining step and characteristics performed at the machining center. Accordingly, the machining accuracy and process efficiency of the machining center are greatly affected by the accuracy and speed of tool change in the ATC.

In particular, in the case where the automatic tool change is temporarily stopped due to an external factor, a series of processing steps for solving the cause of the temporary stop and continuing the tool change operation is manually performed by the operator to inhibit the overall process efficiency of the machining center As the cause of the problem.

When an operation error occurs due to a power interruption or a drive interruption such as tool intervention or tool interruption while automatically exchanging tools using ATC, the operator must know the direction of rotation of the ATC arm, the presence or absence of tools of the ATC arm and the spindle head, The stop position of the ATC arm is individually determined, the rotation direction of the ATC arm is determined, and the return of the ATC arm and the clamper operation of the tool are manually performed along the determined rotation direction. Accordingly, various attempts have been made to improve the accuracy and speed of tool change by automating the process of returning ATC arm from ATC in which operation error occurs in order to increase the process efficiency of the machining center.

However, the clamping / unclamping position for the tool clamper, which is essential for conventional automatic tool changing, and the home position and stop position of the ATC arm are obtained using four proximity sensors that detect the pulse signal, It is only possible to confirm the start time of the operation, unclamping operation, clamping operation and tool change stop operation, and the current position of the ATC arm driven by the continuous rotation trajectory or the completion time of each operation can be confirmed There is no problem.

Accordingly, when an operation error occurs at an arbitrary point in time at which the automatic tool change is performed, the current position of the ATC arm can not be detected, so that there is a problem that a reference for determining the return direction of the ATC arm can not be provided. Such a conventional ATC operation error recovery device inevitably requires individual manual work of the operator, thereby serving as a cause of lowering the automation rate of the ATC.

Therefore, a new automatic tool changer capable of automatically recovering an ATC arm even in the case of an operation error occurring at any moment of the ATC arm by detecting the current position of the ATC arm in real time is required.

It is an object of the present invention to provide an automatic tool changer having an encoder capable of detecting the position of an ATC arm in real time with respect to the entire rotational trajectory of the ATC arm.

Another object of the present invention is to provide a method of automatically exchanging tools using the automatic tool changer as described above.

According to an aspect of the present invention, there is provided an automatic tool changer comprising: a tool change arm for performing a rotary movement and a linear movement in response to a tool change signal and exchanging a tool between a tool magazine and a spindle; A cam assembly for driving the tool change arm along a displacement diagram of the structure, a driver for providing a driving force for rotating the cam structure, an encoder for detecting the position of the tool change arm in real time, , The return direction of the tool change arm is automatically determined according to the failure position of the tool change arm detected by the encoder, the tool change arm is returned to the home position along the return direction, And a tool change controller having a fail-over unit for restoring the tool.

In one embodiment, the tool change controller is configured to determine the position of the tool on the displacement diagram, including the fault location, an unclamping area for detaching the tool from the spindle, and a clamping area for attaching the tool to the spindle And an operation information storage unit for storing an information storage unit, a tool detachment state in the detachment area, a tool attachment state in the attachment area, and a start state and an end state of the tool exchange arm at the home position.

In one embodiment, the failure recovery unit includes a return direction detecting unit for determining a return direction of the tool change arm by discriminating the relative position of the faulty position with respect to the detachment area and the attachment area on the displacement diagram, An arm drive signal for driving the tool change arm and a return drive signal generator for generating a clamper drive signal for selectively changing the attachment state and the attachment state.

In one embodiment, the desorption region is specified by the desorption start position and the desorption end position in the displacement diagram, and the attachment region is specified by the deposition start position and the deposition end position in the displacement diagram, Is determined on the basis of the relative position of the obstacle position, the detachment end position, and the attachment end position on the line.

According to exemplary embodiments of the present invention for achieving the above-mentioned object, a method of automatically exchanging tools using the automatic tool changer is disclosed. First, the tool change arm is driven by a rotational movement along the displacement diagram of the cam structure and a linear movement with a constant amplitude by the tool change signal. Wherein the tool change arm is configured to detect the position of the displacement line where the drive failure of the tool change arm has occurred as a failure position and to compare the failure position with the tool removal end position and the tool attachment end position of the displacement line, . Subsequently, the tool change arm is driven in accordance with the return mode to return to the original position.

In one embodiment, after determining the return direction, the method further includes applying a clamper drive signal to the tool clamper to selectively detect a tool detachment state and an attachment state relative to the spindle to selectively change the detachment or attachment state .

According to the automatic tool changer and the automatic tool changer method according to the exemplary embodiments of the present invention as described above, it is possible to perform the automatic tool changer at each point of the displacement diagram, which is the movement locus of the tool change arm, The position can be detected and stored in real time. In addition, the tool removal end position, tool attachment end position, and operation state at each position can be stored for each position. Accordingly, when the drive failure occurs, the current position at the time of failure occurrence is detected as a failure position, and the failure mode is automatically determined based on the determination of the failure end position and the attachment end position. The detachment tool is automatically reattached to the spindle by inspecting the tool detachment and attachment state in the detachment area and the attachment area while automatically returning the tool exchange arm.

An appropriate recovery mode is selected by detecting the location of the drive failure using an encoder in real time to specify the position of the failure and selectively reassigning the tool on the spindle according to the position of the failure. Accordingly, automation rate and accuracy of the automatic tool changer can be improved by automating the process of eliminating the drive failure of the automatic tool changer.

1 is a perspective view showing an automatic tool changer according to an embodiment of the present invention.
Fig. 2A is a diagram showing the horizontal displacement of the tool change arm during a unit cycle in which automatic tool change is performed in the automatic tool change apparatus shown in Fig.
Fig. 2b is a view showing the vertical displacement of the tool change arm during a unit cycle in which automatic tool change is performed in the automatic tool change apparatus shown in Fig. 1. Fig.
3 is a flowchart showing a method of automatically exchanging tools of a numerically controlled machine tool using the automatic tool changer shown in Fig.
4 is a flow diagram illustrating the step of determining a recovery mode of a tool change arm in accordance with an embodiment of the present invention.

For the embodiments of the invention disclosed herein, specific structural and functional descriptions are set forth for the purpose of describing an embodiment of the invention only, and it is to be understood that the embodiments of the invention may be practiced in various forms, The present invention should not be construed as limited to the embodiments described in Figs.

The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms may be used for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between. Other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprise", "having", and the like are intended to specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, , Steps, operations, components, parts, or combinations thereof, as a matter of principle.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be construed as meaning consistent with meaning in the context of the relevant art and are not to be construed as ideal or overly formal in meaning unless expressly defined in the present application .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing an automatic tool changer according to an embodiment of the present invention. Fig. 2a is a view showing the horizontal displacement of the tool change arm during a unit cycle in which the automatic tool change is performed in the automatic tool change apparatus shown in Fig. 1, Fig. 2b is a view showing the automatic tool change in the automatic tool change apparatus shown in Fig. Lt; RTI ID = 0.0 > a < / RTI > tool exchange arm during the unit cycle being performed.

Referring to FIGS. 1, 2A and 2B, an automatic tool changer (ATC) 1000 according to an embodiment of the present invention includes a rotary movement R1 and a linear movement L The tool change arm 100 that exchanges a tool (not shown) between the tool magazine M and the spindle (not shown), the tool change arm 100 along the displacement diagram of the cam structure 210 A tool changer controller (300) including a cam assembly (200) for driving the cam structure (210), a driver (300) for providing driving force for rotating the cam structure (210), and an encoder (400).

The tool magazine M includes a tool accommodating portion for accommodating a tool for each tool port, a tool mount for accommodating the tool in the tool accommodating portion, and a magazine controller for controlling the operation of the tool magazine in connection with the tool accommodating portion and the tool mount (Not shown) that is constructed and is used to machine the workpiece.

The machine tool is controlled according to a machining algorithm input to a numerical controller N to automatically process the workpiece, and the magazine controller constitutes a part of the numerical controller, .

The automatic tool changer 1000 operates to automatically exchange the tool between the magazine M and a spindle (not shown) of the machine tool. Therefore, the automatic tool changer 1000 is controlled by the magazine controller interlocked with the numerical controller N to detach the work tool from the RAM spindle in which the specific machining step is completed, and attach the selected tool selected from the tool magazine .

In the case of the present embodiment, the automatic tool changer 1000 is disposed between the tool magazine M and the machine tool, which are disposed adjacent to each other, and exchanges the tool with the tool. The tool change between the working tool and the selection tool is carried out by a tool change arm 100 which performs a first rotational motion R1 rotating about the z axis parallel to the xy plane and a linear motion L moving along the z axis Lt; / RTI >

The tool change arm 100 is provided in the form of a slender member having a length longer than the width and a gripper 110 is disposed at the end of the slender member so as to be able to be fixed while transferring the tool. At the center of the elongated member, a fixing portion 120 is disposed and fixed to the cam assembly 200 disposed at the upper portion so as to be rotatable and linearly movable. Accordingly, the tool exchange arm 100 can be expanded and contracted along the z-axis direction while rotating on the x-y plane. That is, the tool exchange arm 100 is fixed to the cam assembly 200 so as to be rotatable about the z-axis and linearly move along the z-axis.

The cam assembly 200 is driven by the driver 300 to transmit rotational and linear motion to the tool change arm 100.

The tool receiving portion of the tool magazine and the ram spindle of the machine tool are not located on the same plane and the tool change arm 100 needs to be kept in the same position while the tool detachment process in the spindle proceeds. Thus, the tool exchange arm 200 is required to extract a selected tool from the tool receiving portion of the tool magazine M and to remove the work tool from the ram spindle of the machine tool, and linear detachment of the tool from the spindle proceeds It is required to maintain the same position during driving of the cam assembly 200.

Since the cam assembly 200 interlocked with the driver 300 is required to selectively maintain the stationary state of the tool exchange arm 100 interlocked with the cam assembly 200 while maintaining the rotational movement, (200) has a mechanical structure capable of implementing a kinematical halt state. Kinematic steady state means a stationary state in a mechanical structure where the output link can stop, despite the movement of the input link.

In the case of the present embodiment, the cam assembly 200 includes the cam structure 210 as a mechanical structure for implementing a kinematic stop state. Therefore, the tool change arm 100 is partially mechanically stopped while moving along the locus of the cam structure 210 during one rotation of the cam structure 210. That is, the tool change arm 100 is detached and attached to the spindle while mechanically pausing while rotating along the horizontal movement locus corresponding to the cam displacement diagram of the cam structure 210. [

Although the cam structure 210 is illustratively shown as means for implementing the kinematic stop state of the tool change arm 1000 in the present embodiment, it is possible to use only the cam structure 210 It is apparent that various power transmission mechanical structures can be used.

The cam assembly 200 includes not only a cam structure 210 for implementing a kinematic stopping state but also a rotation shaft (not shown) connected to the drive machine 300, an arm for transferring the tool exchange arm 100 in the z- And may include various mechanical structures such as a transfer shaft (not shown) and a transmission structure connected to the arm transfer shaft to transfer a linear driving force. For example, the transmission structure may be provided in a combination of a rack and a pinion (not shown). Alternatively, linear movement of the tool change arm 100 may be implemented using a vertical cam structure (not shown) capable of implementing linear movement in the z-axis direction. For example, the tool change arm 100 moves along a linear locus having a constant amplitude along the z-axis during a tool change cycle, as shown in FIG. 2B.

Accordingly, when the tool change signal is applied, the cam assembly 200 is continuously driven by the actuator 300 and the tool change arm 100 is moved in the z-axis direction including the linear movement along the z- The tool change is automatically performed with respect to the ram spindle.

At this time, the driver 300 is configured as a motor structure that transmits rotational force to the cam assembly 200. For example, the driver 300 includes a servo motor that can vary the speed of the motor to reduce impact or noise during tool change, and smoothly perform a tool detachment operation in the spindle.

The actuator 300, the cam assembly 200 and the tool exchange arm 1000 are organically controlled by the tool change controller 400 to automatically exchange the tool. The tool change controller 400 performs the automatic tool change A tool suitable for the machining step in the machine tool can be automatically attached to the spindle of the machine tool in cooperation with the numerical controller N for controlling the numerical control machine tool having the apparatus 1000. [

In particular, the tool change controller 400 controls the position of the tool change arm 100 on the horizontal displacement line through the encoder 411 disposed in the cam assembly 200, the unclamping position of the tool change arm 100, (Z1 in Fig. 2A), and a clamping area (Z2 in Fig. 2A) for attaching the tool to the spindle; a tool detachment state in the detachment zone Z1; An operation information storage unit 420 for storing the tool attachment state in the attachment region Z2, the start state and the end state of the tool change arm 100 in the home positions A and K which are the start positions of the tool change operation, And a return direction of the tool change arm (100) is automatically determined according to a failure position of the tool change arm (100) detected by the encoder (411) when a drive failure occurs in the tool change arm The tool change arm is moved to the home position A , K) and restoring the tool change state to the tool change initial state.

The encoder 411 is composed of a combination of logic circuits composed of semiconductor elements and is arranged in the form of an integrated circuit, and optionally an analog-to-digital converter can be additionally provided. The encoder 411 may interrupt the operation signal of the servo motor provided to the driver 300 and detect the position of the continuous rotation locus driving the cam structure 210 in real time.

That is, by detecting the position in real time along the locus of rotation of the drive shaft of the cam structure 210 connected to the servo motor, the position of the cam structure 210 can be continuously determined with respect to the rotation locus of the cam structure 210.

The position information storage unit 410 stores the position information on the xy plane of the tool exchange arm 100 corresponding to the rotation position of the drive shaft of the cam structure 210 transmitted from the encoder 411 and the cam displacement diagram of the cam structure 210 By mapping the horizontal displacement line, which is the movement locus, the time and position can be specified at each point of the horizontal displacement line. Since the tool change arm 100 rotates along the horizontal displacement line on the xy plane and performs the tool change while linearly moving along the z direction, the position and time are specified along the three-dimensional movement trajectory of the tool change arm 100 do.

Therefore, the position information storage unit 410 can continuously specify the position of the tool change arm 100 at every moment until the end of the tool change operation is started. In particular, a tool change operation that determines the characteristics of the tool change operation can precisely control the tool change operation by storing the time and position of the tool removal and attachment areas Z1, Z2 at the start and end points and the spindle.

The operation information storage unit 420 may store information on the operation state of the tool change arm 100 at a position specified by the encoder 411 in association with the position information storage unit 410. [

For example, whether or not a tool detachment signal is applied to the spindle and the tool detachment state are stored for the tool detachment zone Z1. Whether or not the tool attachment signal is applied to the spindle for the tool attachment zone Z2, Save the attachment status. For the first backslash area Z3 and the second backslash area Z4 adjacent to the home positions A and K, whether or not a tool change start signal is applied to the tool change arm 100, Information on the start operation state and the end state is stored in the operation information storage unit 420. [

When the tool change arm 100 stops driving according to a short circuit of the power supply, interference with the tool, or other emergency situation while performing the tool change operation, the positional information storage unit 410 and the operation information storage unit 420 The position information and the operation information of the tool change arm 100 are transmitted to the failure recovery unit 430.

In the case of this embodiment, the failure recovery unit 430 includes a return direction detecting unit 432 for automatically determining the return direction of the tool change arm 100, And a return drive signal generation section 434 for generating a drive signal for driving the tool to be attached or detached from the spindle.

If a drive failure occurs in the tool change arm 100, the current position of the tool change arm 100 is transmitted from the position information storage unit 410 to the return direction detection unit 432, stored in the failure position, The type of the fault is transferred from the operation information storage unit 420 to the return drive signal generation unit 434 and stored.

In one embodiment, the return direction detecting section 432 determines the relative position of the faulty position with respect to the detachment zone Z1 and the mounting zone Z2 on the horizontal displacement diagram shown in FIG. 2A, 100 are automatically determined.

For example, the positional information storage unit 410 specifies the detachment start position (B) and the detachment end position (C), which are distinguished from the displacement diagram by a time interval after the start of the process, , And stores the attachment region Z2 by specifying an attachment start position (H) and an attachment end position (I) that are separated from the displacement diagram by a time interval after the start of the process. At this time, the return direction detecting section 432 determines the return direction of the tool change arm 100 by comparing the failure position with the attachment / detachment end position C and the attachment end position I.

The return direction of the tool exchange arm 100 determined by the return direction detection section 432 is transmitted to the return drive signal generation section 434 to return the tool exchange arm 100 to the home position, .

For example, the return drive signal generating section 434 includes an arm drive signal generating section 434a for driving the tool exchange arm 100 along the return direction, and an arm drive signal generating section 434b for driving the tool exchange arm 100 in the detachment state Z1 and the attachment state Z2 And a clamper driving signal generating unit 434b for generating a clamper driving signal for selectively changing the driving signal. The return direction includes a forward direction or a reverse direction depending on the failure position.

The return direction of the tool exchange arm 100 generated by the return direction detecting section 432 is transmitted to the arm drive signal generating section 434a and the arm drive signal generating section 434a generates the arm drive signal generating section 434a, Thereby generating an arm drive signal for driving the motor 100.

When the return direction is determined in the forward direction, the tool change arm 100 is moved in the same direction as the direction of driving along the horizontal displacement line, and returns to the tool change end point K. [ The tool change time point (A) and end point (K) represent substantially the same position as the cam phase angles are 0 ㅀ and 360 ㅀ and correspond to the home position of the tool change process. When the return direction is determined in the reverse direction, the tool change arm 100 is moved in the direction opposite to the direction of driving along the horizontal displacement line, and returns to the tool change point (A).

At this time, the tool or the selective tool fixed to the gripper 110 may be fixed to the spindle or the tool magazine according to the position of the obstacle while the tool exchange arm 100 is returning. At this time, the clamper driving signal generating unit 434b obtains information on the operation state of the attaching region Z1 and the attaching region Z2 from the operation information storing unit 420 and outputs a drive signal for the tool clamper .

For example, when a drive failure occurs in the middle of the movement of the tool change arm 100 through the detachment zone Z1 of the horizontal displacement diagram to the attachment zone Z2, the return direction detection unit 432 moves in the reverse direction And is controlled to return to the tool change starting point (A). At the time when the drive failure occurs, the working tool of the spindle is detached from the spindle and fixed to the first gripper 111, and at the same time, the selection tool extracted from the tool magazine M is fixed to the second gripper 112. Therefore, since the operation information storage unit 420 stores the signal information indicating the tool removal state as operation information corresponding to the tool detachment zone Z1, the clamp drive signal generation unit 434b controls the tool change arm 100, When the return operation is performed to return to the detachable area, a tool attachment signal is transmitted to a tool clamper (not shown) to mount the detached work tool on the spindle again.

Then, when the tool change arm 100 continuously moves along the reverse direction and passes through the disengagement start point S1 of the disengagement zone Z1, the operation state for the disengagement zone Z1 is switched to the tool attachment state, The operation information storage unit 420 stores the converted operation state of the detachment zone Z1.

Alternatively, the tool may not be detached from the spindle depending on the cause of the failure at the fault location. In this case, since the operating state for the detachable zone Z1 is still stored in the attached state, it is not necessary to separately generate the clamper driving signal in the returning process. Thus, the clamper drive signal is selectively generated depending on the tool detachment and attachment state in the spindle.

If a drive failure occurs after passing through the attachment end position T2 of the tool attachment region Z2, it is necessary to return the tool change arm 100 in the reverse direction since the tool change of the working tool and the selection tool has already been performed on the spindle none. In this case, the return direction is determined in the forward direction, and in this case, there is no need to change the attachment / detachment state of the tool and the clamper driving signal may not be generated.

3 is a flowchart showing a method of automatically exchanging tools of a numerically controlled machine tool using the automatic tool changer shown in Fig.

1 to 3, the numerical controller N of the numerically controlled machine tool having the automatic tool changer 1000 applies a tool change signal when a tool change is required according to the machining conditions of the workpiece. Accordingly, the tool magazine M and the automatic tool changer 1000 perform a tool change operation.

When a tool change signal is applied, drive power is applied to the actuator 300 and the cam structure 210 of the cam assembly 200 and the drive shaft of the linear transporting means (not shown) are rotated. While the drive shaft rotates once, the cam structure 210 moves while forming a cam displacement curve on the x-y plane.

Accordingly, the tool exchange arm 100 driven by the cam structure 210 moves in a horizontal direction on the xy plane to correspond to the cam displacement diagram, and rotates along the horizontal displacement diagram as shown in Fig. 2A Perform exercise. Further, by the linear transporting means of the cam assembly 200, the tool exchange arm 100 is moved along the z-axis direction during one rotation of the cam structure 210 constituting the tool change cycle, as shown in FIG. 2B Lt; RTI ID = 0.0 > of < / RTI >

Accordingly, the tool change arm 100 is driven by the tool change signal by the linear motion having the predetermined amplitude and the rotational motion along the displacement diagram of the cam structure (step S100).

2a shows the horizontal rotation angle of the tool change arm 100 and Fig. 2b shows the tool change arm 100 along the z-axis direction, with respect to the respective cam phase angle at which the cam structure 210 constitutes a tool change cycle. Represents the distance traveled.

The tool change arm 100 which is waiting at the tool change start position A which is the home position starts moving along the horizontal displacement together with the tool change signal. The tool change arm 100 rotates along the horizontal displacement curve corresponding to the cam displacement curve and moves to the tool detachment start position B via the first backslash area Z3 of the cam structure 210. [

The first and second grippers 111 and 112 of the tool exchange arm 100 are disposed adjacent to the spindle of the machine tool and the tool receiving portion of the tool magazine M, respectively. In this embodiment, the phase angle of the cam structure 210 is about 61 ° and the tool change arm 100 is rotated about 75 ° from the groove position A Respectively. However, it is apparent that the phase angle of the cam structure with respect to the disengagement start position (B) and the rotation angle of the tool exchange arm may vary depending on the configuration of the automatic tool changer 1000. [

The cam structure 210 still rotates at the disengagement start position B but the tool change arm 100 remains stationary for tool change in the spindle and tool magazine M. [ That is, the tool change arm 100 stops rotating and linear movement and while the present position is maintained, the work tool mounted on the spindle is detached and fixed to the first gripper 111 and the tool of the tool magazine M The selected tool extracted in the storage portion is fixed to the second gripper 112.

The tool detachment between the spindle and the tool change arm 100 is performed in the detachment zone Z1 between the detachment start position B and the detachment end position C while the tool change arm 100 is detached from the detachment zone Z1, Thereby maintaining the stationary state. In the present embodiment, the detachment end position C is set to a point 82 degrees in terms of the cam phase angle, and the detachment zone Z1 is set in the range of the cam phase angle 61 to 82 degrees.

When the tool detachment is completed, the tool change arm 100 moves linearly from the spindle and is spaced from the spindle. In the case of this embodiment, the spindle is installed along the z-direction, and the tool has a structure to be detached and attached by moving along the z-axis direction. Thus, when the tool detachment from the spindle is completed, the rotation of the tool change arm 100 linearly moves upward and downward along the z-axis and is separated from the spindle depending on the structure of the spindle. Thus, the tool change arm 100 is sufficiently spaced from the spindle while detaching the work tool to complete the preparation step for transferring the work tool to the tool magazine M.

Therefore, the tool change arm 100 maintains a mechanical stop state with respect to the cam structure 210 by driving the tool change arm 100 from the disengagement start position B to the work tool transfer position (point D) without rotating movement. That is, the mechanical stop state for detachment of the work tool is maintained from the tool detachment start position (B) to the work tool transfer position (D).

In the present embodiment, the tool exchange arm 100 is illustratively moved by 155 mm along the z-axis direction. However, the movement distance in the z-axis direction can be variously modified according to the structure of the machine tool, The spindle is also disposed along the horizontal direction, not the vertical direction, so that the linear movement of the tool change arm 100 may be performed along the horizontal direction.

Then, the mechanical stop state is canceled and the tool change arm 100 starts rotating again. At this time, both the rotary motion and the linear motion are simultaneously performed until the tool change arm 100 maintains a sufficient distance from the spindle (point E). However, if the tool change arm 100 is sufficiently spaced apart, (Point F). Then, the tool moves to the attachment preparation position (point G) while simultaneously performing the rotational movement and the linear movement so as to approach the spindle for attaching the second gripper 112 fixed with the selection tool to the spindle.

At the attachment preparation position G, the tool change arm 100 stops rotating and maintains a mechanical stop state with respect to the cam structure 210. [ The tool change arm 100 performs only the linear movement without rotating and moves to the attachment start position (point H) which is the lower portion of the spindle.

At the attachment start position H, the tool change arm 100 is stopped and the selection tool fixed to the second gripper 112 is attached to the spindle. As with the detachment zone Z1, the cam structure 210 still rotates at the attachment start position H, but the tool change arm 100 remains stationary for tool change. The selection tool fixed to the second gripper 112 is coupled to the spindle and the work tool fixed to the first gripper 111 is returned to the tool storage portion of the tool magazine M. [

The mechanical stopping state for attachment of the tool to the spindle is maintained until the attachment end position I is reached. In particular, the attachment of the working tool between the spindle and the tool change arm 100 is carried out in the attachment zone Z2 between the attachment start position H and the attachment end position I, (Z2). In the case of the present embodiment, the attachment end position H is set to an area between 278 and 299 degrees in cam phase angle.

When the attachment of the spindle of the working tool is completed, the tool changing arm 100 performs the turning motion while maintaining the horizontal position, and moves to the tool replacement completed position (point J). The cam structure 210 completes the tool change cycle while maintaining the position of the tool change arm 100 while passing through the second backslash area Z4. Therefore, the tool change arm 100 is located at the home position K.

In the case of the present embodiment, the tool change arm 100 is rotated in the reverse direction to move to the tool change completed position J. Accordingly, in the tool change arm 100 according to the present embodiment, when the tool change is completed, the tool change arm 100 rotates by 180 degrees and the positions of the first and second grippers 111 and 112 are exchanged and disposed. However, it is apparent that the tool change arm 100 can be configured to rotate 360 占 when the tool change cycle is completed by changing the configuration of the cam structure 210. [

At this time, the encoder 411 interrupts the operation signal of the servo motor driving the cam structure 210 to detect the position in real time with respect to the continuous rotation locus of the drive shaft driving the cam structure 210, The positional information is obtained continuously with respect to the horizontal and vertical displacement diagrams of the apparatus 100.

The positional information of the tool change arm 100 obtained by the encoder 411 is transmitted to and stored in the positional information storage unit 410 and the drive status of the tool change arm 100 at each position is stored in the operation information storage unit 420). For example, with respect to the tool change start time A before the start time B of attachment / detachment, whether or not the generation of the desorption signal is stored in the operating state related to the tool change start time A, For the preparation position G, whether or not an attachment signal is generated can be stored as an operation state relating to the attachment preparation position G. [

When the driving of the tool change arm 100 is stopped in accordance with the emergency situation during the tool change operation, the information stored in the position information storage unit 410 and the operation information storage unit 420 is used The positions of the vertical and horizontal displacement diagrams are detected as failure positions (step S200).

For example, when the driving shaft of the cam assembly 200 is stopped due to an emergency, the position information and operation information of the tool change arm 100 are transmitted to the position information storage unit 410 and the operation information storage unit 420, To the fault recovery unit 430. The current position of the tool change arm 100 corresponding to the stop position at which the drive shaft stops is transmitted to the return direction detecting unit 432 and detected as a fault position (step S300).

Then, the return mode of the tool change arm 100 is automatically determined (step S400). In this embodiment, the return mode of the tool change arm 100 is automatically determined on the basis of whether or not the work tool is detachably attached to the tool change arm 100 and whether or not the selective tool is attached to the spindle. That is, it is possible to automatically determine the return mode of the tool change arm 100 by comparing the tool removal end position B and the tool attachment end position I with the failure position and judging whether the spindle is attached to the working tool and the selection tool have.

The tool change arm 100 is driven in accordance with the return direction determined according to the return mode of the tool change arm 100, and returned to the home position, thereby automatically eliminating the drive failure (step S500). In particular, when a drive failure occurs in the tool change process, the drive failure is automatically displayed on the operation panel P, and the operator can easily solve the drive failure by selecting the automatic recovery algorithm while confirming the operation state of the numerically controlled machine tool can do.

4 is a flow diagram illustrating the step of determining a recovery mode of a tool change arm in accordance with an embodiment of the present invention.

4, when the failure position is transmitted from the position information storage unit 410 to the failure recovery unit 430 (step S410), the return direction detection unit 432 detects the tool removal end position C (Step S420) to determine the return direction of the tool change arm 100 (step S420).

For example, when a drive failure occurs at a position where the cam phase angle is smaller than 82 mm, the obstacle position is evaluated as a position smaller than the tool release end position C (step S421). At this time, the return direction detecting unit 421 determines the return direction of the stopped tool change arm 100 in the reverse rotation direction of the drive shaft of the cam structure 210 (step S431) and checks whether or not the work tool is coupled to the spindle (Step S440). Accordingly, the return direction detecting unit 421 performs a first recovery mode for solving the driving failure.

If a drive failure occurs before the work tool is secured to the first gripper 111 from the spindle, the work tool can still remain engaged with the spindle and can be detached from the spindle and fixed with the first gripper 111, If so, the tool and the spindle can remain attached and detached.

Therefore, if the work tool is still attached to the spindle, the arm drive signal generator 434a is driven to generate an arm drive signal (step S441). Alternatively, if the work tool is detached from the spindle, a clamp drive signal is first generated from the clamp drive signal generation section 434b (step S442), and the detached work tool is recombined again with the clamp and then returned to the home position A do.

Therefore, the first recovery mode can selectively generate the clamp drive signal according to the coupled state of the work tool and the spindle.

Alternatively, if the cam phase angle is greater than 82 mm and the drive failure occurs at a position less than 299 mm, the failure position is evaluated to be greater than the tool release end position C and less than the tool attachment end position I S422). In this case also, the return direction detecting section 421 determines the return direction of the stopped tool change arm 100 in the reverse rotation direction of the drive shaft of the cam structure 210 (step S431) and determines whether or not the work tool is coupled to the spindle (Step S440). Accordingly, the return direction detecting unit 421 performs a second recovery mode for solving the driving failure.

In this case, when a working tool is fixed to the first gripper 111 and a driving failure occurs while the selection tool extracted from the tool magazine is fixed to the second gripper 112 while moving to couple the selection tool to the spindle, The combination of the spindle and the selection tool has not yet been performed. Accordingly, when a drive failure occurs, the tool change arm 100 returns to the home position along the reverse rotation direction, and the tool change process is performed again at the home position A.

If the tool change arm 100 is moved without a work tool normally fixed to the first gripper 111 from the spindle and a drive failure occurs, the work tool can still remain engaged with the spindle, The work tool and the spindle can be kept in a detached state if a drive failure occurs due to other reasons.

Therefore, as in the first recovery mode, if the working tool is still attached to the spindle, the arm drive signal generation unit 434a is driven to generate the arm drive signal (step S441). Alternatively, if the work tool is detached from the spindle, a clamp drive signal is first generated from the clamp drive signal generation section 434b (step S442), and the detached work tool is recombined again with the clamp and then returned to the home position A do.

Therefore, the second recovery mode can also selectively generate the clamp drive signal according to the coupled state of the work tool and the spindle.

If a drive failure occurs at a position where the cam phase angle is larger than 299 mm, the obstacle position is evaluated to a position larger than the tool attachment termination position I (step S423). In this case, the return direction detecting section 421 determines the return direction of the stopped tool exchange arm 100 in the same direction as the rotational direction of the drive shaft of the cam structure 210 (step S432) and determines whether the selection tool is coupled to the spindle (Step S450). Accordingly, the return direction detecting unit 421 performs a third recovery mode for solving the driving failure.

In this case, the selection tool fixed to the second gripper 112 is coupled to the spindle and the work tool fixed to the first gripper 111 is stored in the tool storage portion of the tool magazine M, ) Is not equipped with a tool. Therefore, the tool change arm 100 continues to move in the same direction as the original rotation direction, so that the tool change arm 100 does not move to the home position K, (Step S451).

When the tool change is completed, the first and second grippers 111 and 112 are located at the home position K and the home position A, respectively. The home positions A and K are positions where the tool change arm 100 is disposed when a tool change signal is applied. Thus, they are physically different but all function as the home position of the tool change cycle, since they are the same as the start positions of the tool change cycles.

Alternatively, if the selection tool is not sufficiently coupled to the spindle as a result of the tool failure, the direction of the return is corrected in the reverse direction (step S452) and the clamp drive signal is generated (step S453). The arm drive signal is generated (step S454) to return the tool exchange arm 100 to the spindle and to rejoin the select tool to the spindle. Thereafter, the tool change arm 100 may be returned to the home position A by continuously returning in the reverse direction, rejoining the working tool to the spindle.

Accordingly, when a drive failure occurs in the tool change arm 100, the return direction of the tool change arm 100 is automatically determined according to the failure position, the tool engagement state in the spindle is restored to the state before the tool change, By returning the replacement arm 100 to its original position, the state before the tool change can be automatically recovered. That is, it is possible to automatically solve the drive failure caused by the tool change process.

Various means can be used to automatically resolve drive failures.

The drive of the tool change arm 100 is stopped and a drive failure alarm is generated on the operation panel P connected to the tool change controller 400 and the numerical controller N Occurs. At this time, the operator of the numerical control machine tool can automatically solve the drive failure according to various return modes according to the failure position by inputting only the start command of the automatic recovery algorithm for removing the drive failure on the operation panel P.

According to the automatic tool changer as described above and the automatic tool changer using the same, it is possible to detect and store the position in real time at each point of the displacement diagram, which is the movement locus of the tool change arm, using the encoder during the automatic tool changer have. In addition, the tool removal end position, tool attachment end position, and operation state at each position can be stored for each position. Accordingly, when the drive failure occurs, the current position at the time of failure occurrence is detected as a failure position, and the failure mode is automatically determined based on the determination of the failure end position and the attachment end position. The detachment tool is automatically reattached to the spindle by inspecting the tool detachment and attachment state in the detachment area and the attachment area while automatically returning the tool exchange arm.

Conventionally, when a drive failure occurs in the tool change arm, the operator confirms the failure position and manually confirms the attachment state of the spindle tool according to the failure position, thereby individually performing the recovery direction of the tool change arm and re-attaching the tool.

However, in the case of the present invention, an appropriate recovery mode is selected by detecting the position where the drive failure has occurred using the encoder in real time to specify the failure position and selectively reassigning the tool in the spindle according to the failure position. Accordingly, automation rate and accuracy of the automatic tool changer can be improved by automating the process of eliminating the drive failure of the automatic tool changer.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the following claims. It can be understood that it is possible.

Claims (6)

A tool change arm for performing rotational movement and linear movement in response to the tool change signal and for exchanging tools between the tool magazine and the spindle;
A cam assembly for driving the tool change arm along a displacement diagram of the cam structure;
A driver for providing a driving force for rotating the cam structure; And
An encoder for detecting a position of the tool change arm in real time and a return direction of the tool change arm automatically according to a failure position of the tool change arm detected by the encoder when a drive failure of the tool change arm occurs, And a fail-safe unit for returning the tool change arm to a home position along a direction of the tool change arm and restoring the tool change initial state to the tool change initial state. The tool change controller of claim 1, wherein the tool change controller stores the fault location on the displacement diagram, an unclamping area for detachment of the tool from the spindle, and a clamping area for attaching the tool to the spindle And an operation information storage unit for storing the position information storage unit, the tool detachment state in the detachment area, the tool attachment state in the attachment area, the start state and the end state of the tool exchange arm at the home position, Device.
The apparatus according to claim 2, wherein the failure recovery unit comprises: a return direction detection unit for determining a return direction of the tool exchange arm by discriminating the relative position of the faulty position with respect to the detachment area and the attachment area on the displacement diagram; And a return drive signal generator for generating a clamper drive signal for selectively changing the attachment state and the attachment state of the tool change arm. 3. The method according to claim 2, wherein the desorption region is specified by a desorption start position and a desorption end position in the displacement diagram and the attachment region is specified by an adhesion start position and an adhesion end position in the displacement diagram, Wherein said displacement position is determined on the basis of a relative position between said failure position, said detachment end position and said attachment end position on a displacement graph. Driving the tool change arm by rotational motion along the displacement diagram of the cam structure and linear motion with constant amplitude by the tool change signal;
Detecting a position of the displacement line where the drive failure of the tool change arm occurs as a fault position;
Automatically determining a return mode of the tool change arm by comparing the tool position and the tool attachment end position of the displacement map with the tool attachment end position; And
And driving the tool change arm according to the return mode to return to the original position. 6. The method of claim 5, further comprising, after determining the return direction, applying a clamper drive signal to the tool clamper to selectively detect the attachment / detachment state and attachment state of the tool relative to the spindle, Gt;

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