JPWO2020079756A1 - Automatic tool changer - Google Patents

Abstract

An automatic tool changer with a tool breakage detection function that moves a plurality of tools held by holding members in an upright position according to an oval path and stops a predetermined tool at an indexing position on the path. An elevating mechanism is used to correspond to the height of the cutting edge of the tool in the path of the tool in the tool indexing device, the indexing device, the replacement tool displacement device that moves the tool at the indexing position to the exchange position with the mating device, and the tool indexing device. It has a tool breakage detecting device for moving a contact, and a breakage determination device for determining a tool breakage based on a detection signal transmitted from the tool breakage detection device according to the presence or absence of contact of the contactor with the cutting edge of the tool.

Description

The present invention relates to an automatic tool changer having a tool breakage detection function for confirming the presence or absence of breakage by contact with a tool cutting edge.

Machine tools such as machining centers are provided with a tool breakage detection device for detecting the breakage of the tool because the machining dimensions may be out of order when the tool is broken such as a blade spill. For example, as a first conventional example, there is a tool breakage detection device in which an optical sensor is installed on the path of a tool that orbits due to the rotation of a roller chain, and the state of the tool is detected depending on the presence or absence of light blocking. Further, as a second conventional example, the following Patent Document 1 discloses a tool breakage detection device using a touch sensor. Specifically, a touch sensor is arranged on the movement locus of the tool change arm, and when the tool change arm moves to pull out the tool and turn, the touch sensor that stands by on the movement locus detects breakage of the tool cutting edge. Will be done. Then, if the touch sensor is non-contact, it is determined that the tool is broken.

Japanese Unexamined Patent Publication No. 11-90786

However, the first conventional example using the optical sensor is affected by the coolant scattered in the processing chamber of the machine tool, and erroneous detection may occur due to refraction of light or the like. Further, the cutting edge of a sharp tool may diffract the light projected from the floodlight and reach the receiver without being blocked, which may also cause erroneous detection. In addition, it is difficult to adjust the optical sensor to accurately detect breakage of the projector and the receiver. When detecting breakage of a plurality of types of tools, if the heights to be detected differ depending on the tool, different numbers of optical sensors are required, which further complicates the adjustment work.

Next, in the second conventional example using the touch sensor, breakage detection is performed for the tool in the process of transferring the tool magazine containing the plurality of tools to the spindle. Therefore, the tool breakage detection device is installed on the turning locus of the tool changing arm at which the tool is transferred from the tool magazine to the spindle, or at a position where the magazine drum moving forward and backward turns to replace the tool with the spindle. The installation position of such a tool breakage detection device is in the processing chamber where the tool is moved by the drive device, which makes it difficult to assemble with a small machine tool or the like, and is not preferable because chips and coolan of the work are scattered.

Therefore, an object of the present invention is to provide an automatic tool changer having a tool breakage detection function in order to solve such a problem.

The automatic tool changer according to one aspect of the present invention is a tool indexing device that moves a plurality of tools held by holding members in an upright posture according to an oval path and stops a predetermined tool at an indexing position on the path. A replacement tool displacement device that moves the tool at the indexing position to a replacement position with the mating device, and a contactor by an elevating mechanism that corresponds to the height of the cutting edge of the tool in the path of the tool in the tool indexing device. It has a tool breakage detecting device for moving the tool, and a breakage determination device for determining the breakage of the tool based on a detection signal transmitted from the tool breakage detection device according to the presence or absence of contact of the contactor with the cutting edge of the tool.

According to the above configuration, the tool indexing device moves the tool according to an oval path, and the indexed tool further moves to the replacement position by the replacement tool displacement device, thereby exchanging the tool with the mating device. Is done. For the replaced used tool, the contactor of the tool breakage detection device moves according to the height of the cutting edge, so that the detection signal is sent to the breakage determination device according to the presence or absence of contact, and the tool breakage occurs. It is judged.

It is a perspective view of the internal structure which showed the machining center. It is a perspective view which showed the automatic tool changer in the tool change state. It is a perspective view which showed the automatic tool changer including the tool breakage detection device from the rear side. It is a top view which showed the rear part of the tool breakage detection device. It is a side view which showed the tool breakage detection device. It is a top view which showed the movement course of a tool in a tool indexing apparatus simply.

Next, an embodiment of the automatic tool changer according to the present invention will be described below with reference to the drawings. In this embodiment, an automatic tool changer incorporated in a machining center will be described as an example. FIG. 1 is a perspective view of an internal structure showing a machining center. The entire machining center 1 is covered with a machine body cover, and a machining chamber for performing cutting of a workpiece is configured inside the machining center 1. In particular, the machining center 1 is movable in the front-rear direction on the base 3, and is assembled on a movable bed 11 provided with wheels.

The machining center 1 is provided with a spindle head 12 at the front portion for holding a tool for machining a workpiece. The spindle head 12 has a spindle chuck 13 to which a tool such as a drill, a reamer, or a boring can be attached and detached, and a spindle motor 14 for rotating a tool held by the spindle chuck 13 is provided. A chuck device 15 that rotatably grips the work to be machined is assembled below the spindle head 12.

The spindle head 12 is incorporated in a machining drive device for moving a tool mounted on the spindle chuck 13 in three axial directions with respect to the work. Specifically, the Y-axis slide 21 is movably mounted in the front-rear direction of the machine body, and the X-axis slide 22 is movably mounted in the width direction of the machine body with respect to the Y-axis slide 21. Further, the Z-axis slide 23 is mounted on the X-axis slide 22 so as to be movable in the vertical direction, and the spindle head 12 is mounted on the Z-axis slide 23.

The machining center 1 is provided with a tool magazine 18 so as to mount such a processing drive device. The tool magazine 18 stores a plurality of tools between the chuck device 15 and the spindle head 12 when viewed in the height direction, and the automatic tool changer 10 (see FIG. 2) is incorporated in the magazine body 24. ing. The machining center 1 is equipped with a spindle head 12, a chuck device 15, a drive mechanism for X, Y, and Z axes, and a control device 19 for controlling the drive of the automatic tool changer 10.

Next, FIG. 2 is a perspective view showing an automatic tool changer in a state where the tool is changed. The automatic tool changer 10 is incorporated in the magazine main body 24, and normally the opening / closing door 25 is closed as shown in FIG. 1 to block coolant, cutting chips, and the like scattered by machining the work. Then, when the tool is changed, the opening / closing door 25 is opened as shown in FIG. 2, and a part of the automatic tool changer 10 is configured to move to the outside accordingly. Although various types of tools T are mounted on the automatic tool changer 10, all of them are represented in a cylindrical shape by omitting a specific shape in FIG. 2 (the same applies to other figures).

The automatic tool changer 10 includes a tool indexing device 10A that holds the tool T detachably by a tool holder 31 and moves the tool T to a predetermined position. The tool holder 31 has a pair of gripping claws sandwiching the neck portion of the tool T. In the tool indexing device 10A, a plurality of tool holders 31 are attached to endless roller chains 33 at regular intervals. .. The roller chain 33 is hung in an oval shape by two sprockets 32 separated from each other, and the rotation is controlled by a drive motor (not shown). In the tool indexing device 10A, a plurality of tools T are moved in the circumferential direction by the rotating roller chain 33, and the tool Tx to be used and the empty tool holder 31 can be indexed.

Next, in the automatic tool changer 10, the tool indexing device 10A is assembled on the oval movable table 35, and the changing tool displacement device 10B enables reciprocating movement in the front-rear direction of the machine body. Specifically, the tool Tx indexed by the tool indexing device 10A and the empty tool holder 31 are configured to move to the tool exchange position 101 with the spindle chuck 13 outside the magazine body 24.

In the replacement tool displacement device 10B, a guide rail 36 is laid on the inner bottom surface of the magazine body 24, and the guide block 37 of the movable table 35 is slidably fitted to the guide rail 36. A nut constituting a ball screw is fixed to the lower side of the movable table 35, and a screw shaft 39 connected to the rotation shaft of the drive motor 38 is screwed into the nut. The drive motor 38 is fixed to the magazine body 24 side. Therefore, the screw shaft 39 is rotated by the output from the drive motor 38, and the tool indexing device 10A moves forward and backward in the longitudinal direction of the oval, that is, in the front-rear direction of the machine body. In the present embodiment, the automatic tool changer 10 will be described with the opening / closing door 25 side as the front and the drive motor 38 side as the rear.

The automatic tool changer 10 is provided with a tool breakage detecting device 10C for checking a broken tool such as a blade spill. 3 to 5 are views showing the tool breakage detecting device 10C. In particular, FIG. 3 is a perspective view showing the automatic tool changer 10 including the tool breakage detecting device 10C from the rear side. Further, FIG. 4 is a plan view showing the rear part of the automatic tool changer 10, and FIG. 5 is a side view showing the tool breakage detecting device 10C.

A touch sensor 41 is used for the tool breakage detection device 10C, and among the tools T moving on the circumference by the tool indexing device 10A, the tool Td positioned at the tool detection position 201 (see FIG. 6) is performed. Here, FIG. 6 is a plan view simply showing the moving course of the tool T in the tool indexing device 10A. The tool detection position 201 is on the oval-shaped tool course 200 as shown in the drawing, and is in front of the rearward reversal position 203 of the longitudinal end where the movement direction of the tool T is reversed when viewed in the front-rear direction. is there. On the other hand, the forward reversal position opposite to the rear reversal position 203 is the indexing position 205 of the tool Tx.

By the way, in the conventional tool magazine, a floodlight 501 and a receiver 502 are provided for the tool T at the rearward reversal position 203. Then, breakage detection is performed depending on whether or not the cutting edge of the tool T passing through the rearward reversal position blocks the light 510. However, the tool breakage detection device using the optical sensor in this way has difficulty in erroneous detection and adjustment as described in the above-mentioned problems. Therefore, in the tool breakage detection device 10C of the present embodiment, the touch sensor 41 arranged at the tool detection position 201 can be moved in the vertical direction to match the height of the cutting edge of the tool Td to be detected in various ways. It has been taken.

The tool breakage detection device 10C has a slide 42 that can move in the vertical direction, from which an arm 43 extends horizontally toward the front, and a touch sensor 41 is attached to the tip thereof. A detection device main body 45 is fixed to the magazine main body 24 via a bracket 44, and the slide 42 is slidably attached to a guide 46 formed on a side surface thereof.

As shown in FIGS. 3 and 4, a drive motor 38 of the replacement tool displacement device 10B is installed in the center of the width direction at the rear of the automatic tool changer 10. Therefore, the detection device main body 45 is fixed at a position shifted from the center so as to avoid the drive motor 38, and the tool detection position 201 is provided in front of the rearward reversal position 203. The tool Td located at the tool detection position 201 in FIGS. 3 and 5 is represented in a rod shape by omitting a specific shape so that the contact with the touch sensor 41 can be easily imagined.

The detection device main body 45 is provided with a ball screw mechanism inside. That is, a screw shaft is assembled in the vertical direction via a bearing, and a nut member fixed to the slide 42 is screwed to the screw shaft. Therefore, by rotating the screw shaft, the slide 42 integrated with the nut member can move in the vertical direction. Further, a servomotor 47 is fixed to the upper part of the detection device main body 45, a belt is hung on a pulley fixed to the rotation shaft and the screw shaft thereof, and the touch sensor 41 can be positioned by the rotation control of the servomotor 47. It has become.

When the touch sensor 41 comes into contact with the cutting edge of a tool Td such as a drill, the internal b contact switch is turned off and an OFF signal is sent to the control device 19 of the machining center 1. The memory of the control device 19 stores a breakage determination program for determining the presence or absence of breakage based on the detection signal transmitted from the touch sensor 41, as well as the drive control of the automatic tool changer 10 that executes breakage detection. .. In the present embodiment, when the OFF signal is transmitted from the touch sensor 41, it is determined that the cutting edge of the tool T is broken. The switch of the touch sensor 41 may use the a contact.

The machining center 1 has a touch panel type operation display device attached to the front surface of the machine body. The operation display device can display work information, operation screens, and the like, and can input dimensions of various tools T by an operator. Therefore, the height of the cutting edge is calculated by inputting the dimensional value of the tool T to be used from the operation display device, and when the breakage is detected, the rotation control of the servomotor 47 is performed based on the value. ing. Further, a holder number is assigned to a plurality of tool holders 31, and the relationship between the number and the dimensional value of the mounted tool T is managed. Therefore, even if the tools T have different dimensions, the tool Td at the tool detection position 201 is obtained by the holder number, and the height of the touch sensor 41 can be adjusted for each tool T.

Subsequently, the operation of the automatic tool changer 10 will be described. First, in the machining center 1, rotation is given to the tool T mounted on the spindle head 12, and machining is performed on the work gripped by the chuck device 15 by drive control in the three axial directions with respect to the machining drive device. Then, the tool T in the spindle head 12 is replaced according to the change in the machining content with respect to the work W. To replace the tool T, the roller chain 34 is given rotation, an empty holder 31 that does not hold the tool T is sent to the indexing position 205, and then the opening / closing door 25 is opened and the movable table 35 is shown in FIG. Move to the position shown in.

The empty tool holder 31 is arranged at the tool change position 101, where the used tool T is delivered from the spindle head 12. After that, rotation is given to the roller chain 34, and the tool Tx to be replaced is sent to the indexing position 205, that is, the tool replacement position 101, and is delivered to the spindle head 12. When the tool is changed in this way, the movable table 35 is returned to the inside of the magazine main body 24 and the opening / closing door 25 is closed. Then, the used tool T is sent to the tool detection position 201 by the rotation of the roller chain 34 as the tool Td to be detected, and the tool breakage detection device 10C performs breakage detection.

In the tool breakage detection device 10C, the rotation of the servomotor 47 is converted into the movement of the slide 42 via the ball screw mechanism, and the height of the touch sensor 41 is adjusted. Specifically, the touch sensor 41 that stands by at the lowered position rises to the preset cutting edge height of the tool Td by driving the servomotor 47. At that time, when the touch sensor 41 comes into contact with the cutting edge of the tool Td, a detection signal indicating normality is sent to the control device 19, and it is determined that there is no abnormality in the tool Td. On the other hand, when the tool Td has a blade spill, the touch sensor 41 does not come into contact with the blade edge, so a detection signal indicating an abnormality is sent to the control device 19, and it is determined that the tool Td is abnormal. Will be done.

Therefore, according to the present embodiment, since the touch sensor 41 is mechanically detected in contact with the cutting edge of the tool Td, false detection unlike the optical sensor does not occur. If an erroneous detection occurs, especially if it is determined that the cutting edge is broken even though the cutting edge is normal, a machining error has occurred in the workpiece, and it is necessary to temporarily stop the machining center 1 in order to change the tool. The cycle time will be greatly extended. In this respect, in the present embodiment, since the state of the cutting edge is determined by the presence or absence of contact of the touch sensor 42, erroneous detection is eliminated and unnecessary drive stop of the machining center 1 is not caused.

Further, since the tool breakage detection device 10C detects breakage by moving the touch sensor 41 up and down, it is possible to handle tools Td having different dimensions, and it is not necessary to perform troublesome adjustment work unlike an optical sensor. .. Further, since the operator sets and inputs the dimensional value of the tool T to be mounted on the automatic tool changer 10 by the operation display device, the rotation of the servomotor 47 is controlled according to the height of the cutting edge. It is possible to easily handle the handling of the tool T and the replacement of the tool.

Further, the automatic tool changer 10 of the present embodiment is incorporated in the magazine main body 24, and the tool Tx or the like indexed by the tool indexing device 10A is moved by the changing tool displacement device 10B as a whole to have a compact configuration. ing. In particular, since the tool breakage detection device 10C is provided on the rear side of the automatic tool changer 10 like the change tool displacement device 10B, it does not affect the machining room of the machining center 1 that executes cutting or the like. In this respect, the processing chamber can be made smaller, which in turn leads to the miniaturization of the machining center 1.

Although one embodiment of the present invention has been described above, the present invention is not limited to these, and various modifications can be made without departing from the spirit of the present invention.
In the above embodiment, the automatic tool changing device 10 having a configuration in which the tool Tx to be machined is arranged at the tool changing position 101 by moving the tool indexing device 10A for indexing the tool T by the changing tool displacement device 10B. As shown, an automatic tool changer having a structure different from this can be used. For example, the tool indexing device may hold a plurality of tool holders, and the replacement tool displacement device may arrange the tool taken out from the tool indexing device by the tool changing arm at the tool changing position.

1 ... Machining center 10 ... Automatic tool changer 10A ... Tool indexing device 10B ... Replacement tool displacement device 10C ... Tool breakage detection device 12 ... Main shaft head 15 ... Chuck device 18 ... Tool magazine 19 ... Control device 31 ... Tool holder 33 ... Roller chain 41 ... Touch sensor 42 ... Slide 45 ... Detection device body 46 ... Guide 47 ... Servo motor 101 ... Tool replacement position 201 ... Tool detection position 205 ... Indexing position

Claims (4)

A tool indexing device that moves a plurality of tools held by a holding member in an upright posture according to an oval path and stops a predetermined tool at an indexing position on the path.
A replacement tool displacement device that moves the tool at the indexing position to a replacement position with the mating device,
A tool breakage detection device that moves the contacts by an elevating mechanism according to the height of the cutting edge of the tool in the path of the tool in the tool indexing device.
A breakage determination device that determines breakage of a tool based on a detection signal transmitted from the tool breakage detection device according to the presence or absence of contact of the contactor with the cutting edge of the tool.
Automatic tool changer with. The tool indexing device has an indexing position at an oval longitudinal end portion in which the moving direction of the tool is reversed, and the tool breakage detecting device has the indexing position on the longitudinal end portion side opposite to the indexing position. The automatic tool changer according to claim 1, wherein the contactor is assembled so as to come into contact with the cutting edge of the tool. The first or second aspect of the exchange tool displacement device, wherein the tool indexing device incorporated in the box-shaped exchange body is moved to move the tool at the indexing position in and out of the storage unit. Automatic tool changer. The automatic tool changer according to claim 3, wherein the tool breakage detecting device is assembled so that the contactor comes into contact with the cutting edge of the tool in front of an oval longitudinal end portion in which the moving direction of the tool is reversed.

Images