JP2023088451A - Operation method of pallet exchange device - Google Patents

Abstract

To prevent foreign matter removal fluid from being unnecessarily supplied toward a seating part on a processing table in a pallet exchange device including a pallet movement lifting part which holds a pallet loaded with a workpiece by a holding member and drives so as to be movable between an exchange position located on the upper side of the processing table of a machine tool and a standby position located on the upper side of a pallet standby table such that the held pallet can be lifted/lowered.SOLUTION: An operation method of a pallet exchange device comprises: detecting whether or not there is adhesion of a foreign matter to a seating part by using a foreign matter detection device (Step S5) before a second pallet loaded with an unprocessed workpiece is moved from a standby position to an exchange position to be seated on the seating part after a first pallet loaded with a workpiece after processing completion is lifted up to the exchange position by a pallet movement lifting part; supplying foreign matter removal fluid to the surface of the seating part when it is detected that there is adhesion of the foreign matter (Step S6); and not supplying the foreign matter removal fluid when it is detected that there is no adhesion of the foreign matter.SELECTED DRAWING: Figure 7

Description

In the present invention, a holding member holds a pallet on which workpieces are loaded, the held pallet can be lifted and lowered, and a replacement position located above a machining table of a machine tool and a predetermined pallet waiting table are positioned above the table. The present invention relates to an operation method of a pallet exchange device provided with a pallet moving/lowering unit that is driven to move between standby positions.

In this type of pallet exchanging device, the pallet moving/elevating unit exchanges the processing side pallet set on the seating portion provided on the upper surface of the processing table with the standby side pallet that has been placed on standby in advance on the pallet standby stand. It is executed by elevating and moving operations (for example, pivoting movements) by .

The pallet exchange operation is normally performed after finishing the machining of the workpieces loaded on the machining side pallet. After the workpiece is machined, if foreign matter such as chips generated during machining adheres to the seating portion, the standby side pallet is moved to the exchange position by the pallet moving/elevating portion and seated on the seating portion. There is a problem that a foreign object gets caught between the seat and the seat, causing a seating failure.

In order to solve this problem, for example, in Patent Document 1, an air outlet is formed on the upper surface of a taper cone provided as a seating portion, and an air supply path provided on a pallet support base is passed upward through this air outlet. By blowing air into the tapered cone, the upper surface of the taper cone and foreign matter around it are blown away. This air blowing operation is performed in a state in which the processing-side pallet is lifted from the seating portion to the replacement position by the pallet moving/elevating portion (see paragraph [0025] of Patent Document 1).

JP-A-7-040180

However, in the operation method of the pallet exchange device disclosed in Patent Document 1, every time the processing side pallet (first pallet) is lifted up by the pallet moving/lifting unit after the processing of the workpieces loaded on the processing side pallet (first pallet) is completed, , an air blowing operation (a foreign matter removing fluid supply operation) is always executed. For this reason, the operation of supplying the foreign matter removing fluid is executed even when no foreign matter adheres to the surface of the seating portion, causing problems such as a decrease in energy saving performance and an increase in cycle time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a pallet changing apparatus capable of preventing an unnecessary supply operation of foreign matter removing fluid even when no foreign matter adheres to a seating portion. to provide a method of operation of

One aspect of the present invention for solving the above problems is
A pallet on which works are loaded is held by a holding member, and the held pallet can be lifted and lowered between a replacement position located above the machining table of the machine tool and a standby position located above the pallet standby stand. A method of operating a pallet changing device having a pallet moving/lowering unit driven to be movable by
A seating portion for the pallet is provided on the upper surface of the processing table,
The pallet exchange device includes a foreign matter detection device capable of detecting foreign matter adhering to the seating portion, and a fluid supply device capable of supplying foreign matter removal fluid to the surface of the seating portion,
After the first pallet, which is loaded with the workpiece and is seated on the seating portion on the processing table, is lifted up to the replacement position by the pallet moving/lowering section after the machining of the workpiece by the machine tool is completed, the It is placed on the pallet standby table by being moved to the standby position and lifted down, while the second pallet, which has been placed on the pallet standby table in advance with the unprocessed workpieces loaded thereon, is called the first pallet. A pallet exchange step of moving to the exchange position by replacement and lifting down after the movement and seating on the seating portion on the processing table to exchange the pallet,
The pallet exchange step includes:
After the first pallet loaded with the processed workpieces is lifted to the replacement position by the pallet moving/lifting unit, the second pallet loaded with the unprocessed workpieces is moved from the standby position to the replacement position. a foreign matter detection step of detecting whether or not a foreign matter is attached to the seating portion using the foreign matter detection device before the seat is seated on the seating portion;
When it is detected that the foreign matter is adhered in the foreign matter detection step, before the second pallet is seated on the seating portion, the fluid supply device supplies the foreign matter removing fluid toward the seating portion. On the other hand, the present invention relates to an operation method including a fluid supplying step of not supplying the foreign matter removing fluid when it is detected that the foreign matter does not adhere.

According to the operation method of the pallet exchange apparatus, the first pallet seated on the seating portion on the processing table and the second pallet placed on the pallet standby stand are moved by the pallet lifting operation and the pallet moving operation by the pallet moving/lowering unit. is executed in the pallet exchange process. Specifically, in the pallet exchange process, the first pallet seated on the seating section is lifted up by the pallet moving elevating section, moved to the exchange position, moved to the standby position, and placed on the pallet standby table. After the second pallet is lifted up and moved to the standby position, it is replaced with the first pallet and moved to the exchange position, and after the movement, the second pallet is lifted down and placed on the seating portion on the processing table. seated. In the operation method of the pallet exchange apparatus of the present invention, after the first pallet loaded with the processed workpieces is lifted up to the exchange position by the pallet moving/lifting section, the first pallet loaded with the unprocessed workpieces is lifted up to the exchange position. Before the two pallets are moved from the standby position to the replacement position and seated on the seating portion, the foreign matter detection device is used to detect whether or not foreign matter is adhered to the seating portion. In the fluid supply step, the operation of the fluid supply device is controlled depending on whether or not foreign matter adheres to the seating portion. That is, in the fluid supply step, when it is determined in the foreign matter detection step that a foreign matter is attached to the seating portion, the foreign matter removing fluid is supplied to the surface of the seating portion by the fluid supply device, while the foreign matter detection step If it is determined that there is no foreign matter adhering to the seating portion, the foreign matter removing fluid is not supplied by the fluid supply device. As a result, it is possible to prevent the foreign matter removing fluid from being unnecessarily supplied even when no foreign matter adheres to the seating portion. In addition, it is possible to reduce the operation time of the fluid supply device for supplying the foreign matter removing fluid, thereby improving the energy saving performance and shortening the cycle time.

In the pallet replacement step, when the second pallet reaches an intermediate position before reaching the replacement position, the pallet moving operation by the pallet moving/lowering unit is interrupted. When it is detected that there is no adhesion, the pallet moving operation by the pallet moving elevating unit is resumed, while when it is detected that there is a foreign object adhered in the foreign matter detection step, the pallet by the pallet moving elevating unit The fluid supply step and the foreign matter detection step are repeatedly executed while the moving operation is being interrupted until the foreign matter detection step detects that no foreign matter adheres, and the foreign matter detection step detects that no foreign matter adheres. Then, it is preferable to restart the pallet moving operation by the pallet moving/lifting unit.

According to this, in the pallet replacement process, the pallet moving operation by the pallet moving/lowering unit is interrupted when the second pallet reaches the intermediate position before reaching the replacement position. During this interruption, when it is detected in the foreign matter detection step that no foreign matter is attached to the foreign matter seating portion, the pallet moving operation by the pallet moving/lowering portion is resumed, while the presence of foreign matter is detected. If so, a fluid application step is performed to apply the foreign material removal fluid to the surface of the seating portion. This fluid supply process is repeatedly performed until no foreign matter is detected in the foreign matter detection process. Therefore, it is possible to reliably prevent the pallet from being caught in the seating operation (lift-down operation) of the pallet with the foreign matter adhering to the seating portion.

It is preferable that the foreign matter detection step is started before the moving operation of the second pallet from the standby position to the intermediate position by the pallet moving/lifting unit is completed.

According to this, execution of the foreign object detection process is started before the second pallet reaches the intermediate position. Therefore, the cycle time can be shortened compared to the case where the foreign object detection process is started after the second pallet reaches the intermediate position.

It is preferable that the intermediate position is a position where the second pallet comes closest to the processing table as long as the seating portion on the processing table is not covered from above by the second pallet.

According to this, while the foreign matter detection process is being executed in the foreign matter detection process, the second pallet can be stopped with the processing table as close to the processing table as possible. Therefore, after the foreign matter detection step is completed, the second pallet can be quickly moved to the replacement position above the processing table.

In the fluid supply step, the foreign substance removing fluid is applied to each of three or more regions equally divided in the circumferential direction with respect to the center position of the seating portion, excluding one region. It is preferable that the foreign matter removing fluid is caused to swirl around the center position and to flow out from the inner side of the processing table toward the outer side in the one region by linearly flowing into the position offset from the position. .

According to this, in the fluid supply step, the foreign substance removing fluid is flowed into each of the three or more regions equally divided in the circumferential direction with respect to the center position of the seating portion, excluding one region. be. At this time, the foreign matter removing fluid is linearly introduced to a position offset from the center position of the seating portion, so that a swirling flow is generated around the center position. This swirling flow flows out from the one region to which the foreign matter removing fluid is not supplied among the plurality of regions. As a result, foreign matter adhering to the seating portion can be blown off over the entire circumferential direction by this swirling flow. Moreover, the swirling flow of the foreign matter removing fluid flows out from the inner side of the processing table toward the outer side in the one area. As a result, it is possible to prevent the foreign matter blown away by the swirl flow from adhering again to the seating portion on the processing table.

As described above, according to the operation method of the pallet changing apparatus according to the present invention, after the first pallet loaded with the processed works is lifted up to the changing position by the pallet moving/lifting unit, the unprocessed works are loaded. Before the second pallet is moved from the standby position to the replacement position and seated on the seating portion, it is detected whether or not foreign matter is attached to the seating portion. supplies the foreign matter removing fluid to the surface of the seating portion, but does not supply the foreign matter removing fluid when it is detected that there is no adhesion of foreign matter, thereby preventing foreign matter from adhering to the seating portion Unnecessary execution of the operation of supplying the foreign matter removing fluid can be prevented. As a result, it is possible to reduce the operating time of the fluid supply device for supplying the foreign matter removing fluid, thereby improving energy efficiency and shortening the cycle time.

FIG. 1 is a schematic plan view of a machine tool provided with a pallet changing device to which the operation method according to Embodiment 1 is applied. FIG. 2 is a perspective view showing a pallet rotating/lifting unit. FIG. 3 is a vertical cross-sectional view showing a state in which the pallet is mounted on the seating portion on the processing table. FIG. 4 is a schematic view taken along line IV--IV in FIG. 1 and viewed in the direction of the arrows. FIG. 5 is a block diagram showing the control configuration of the APC control device. FIG. 6A is a schematic plan view of the pallet changing apparatus showing a state in which a pallet loaded with unprocessed works is held at a replacement position and a pallet loaded with finished works is held at a standby position. FIG. 6B is a schematic plan view of the pallet changing device showing a state in which the pallet loaded with unprocessed workpieces is stopped at an intermediate position. FIG. 7 is a flow chart showing an example of control processing executed by the APC control device. FIG. 8 is a plan view showing a rotary table section according to Embodiment 2. FIG. FIG. 9 is a view corresponding to FIG. 6B showing the third embodiment. FIG. 10 is a vertical cross-sectional view showing a seating portion of a rotary table portion in another embodiment.

(First embodiment)
Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic plan view of a machine tool 1 equipped with a pallet changer 20 (also called APC: Automatic Pallet Changer) to which an operation method according to an embodiment of the present invention is applied.

This machine tool 1 is a horizontal machining center, and includes a bed 2, a column 3, a spindle head 5, a slide table 7, a pallet changer 20, and the like. It should be noted that FIG. 1 shows only the main constituent elements in this embodiment.

The bed 2 is composed of a linear first bed 2a and a second bed 2b connected so that the longitudinal direction is perpendicular to the first bed 2a. The slide table 7 is arranged on the second bed 2b, and is movable in the direction of advance and retreat with respect to the first bed 2a, that is, in the horizontal arrow Z-axis direction under the guidance of guide rails 8. , and is moved in the Z-axis direction by a Z-axis feed mechanism (not shown). A rotary table portion 71 (an example of a processing table) is provided on the slide table 7 , and a pallet 100 loaded with works W is clamped to the rotary table portion 71 . The rotary table portion 71 has a mechanism for rotationally indexing and positioning the pallet 100 at a predetermined rotational angle position. It is

The column 3 is arranged on the first bed 2a and is provided movably in the X-axis direction perpendicular to the Z-axis horizontally under the guidance of a guide rail 4. An X-axis feed mechanism (not shown) to move in the X-axis direction. The spindle head 5 rotatably supports a spindle 6 on which a tool T is mounted, and is held by the column 3 movably in the Y-axis direction perpendicular to the X-axis and the Z-axis. , is moved in the Y-axis direction by a Y-axis feed mechanism (not shown). Further, the main shaft 6 is driven by a main shaft motor (not shown). The operations of the X-axis feed mechanism, Y-axis feed mechanism, Z-axis feed mechanism and spindle motor (none of which are shown) are controlled by a numerical controller 50 (see FIG. 5).

Thus, in this machine tool 1, under the control of the numerical controller 50 (see FIG. 5), the spindle head 5 moves within the X-Y axis plane and the slide table 7 moves in the Z-axis direction. As the spindle head 5 and the slide table 7 move relative to each other in the three-dimensional space, the workpiece W on the pallet 100 mounted on the slide table 7 is moved by the tool T mounted on the spindle 6. processed.

The pallet exchange device 20 includes a pallet standby table 21 provided on the extension of the guide rail 8 on the second bed 2b in the Z-axis plus direction, and a pallet 100 which can be lifted and lowered, and a rotary table section 71. and the pallet standby table 21 (an example of the pallet moving/elevating unit) movably swiveled between them, a camera 26 for capturing an image of each seating portion 72 on the rotary table portion 71, It has a cleaning device 27 (an example of a fluid supply device, see FIG. 4) for removing foreign matter adhering to each seating portion 72, and an APC control device 30 (see FIG. 5).

The pallet rotating/lifting unit 22 includes a turntable 23 erected on the second bed 2b between the pallet waiting table 21 and the guide rail 8, and an exchange arm 24 ( an example of a holding member), a turning actuator (not shown) that turns the exchange arm 24 via the turntable 23, and an elevation actuator (not shown) that moves up and down the turntable 23 in the axial direction. The turning actuator and the lifting actuator are composed of a drive motor, a drive cylinder, and the like, and can adopt hydraulic, electric, pneumatic, or the like as the operation mode. Then, under the control of the APC control device 30, the pallet turning and lifting section 22 drives the turning actuator and the lifting and lowering actuator to perform the pallet exchange operation.

The exchanging arm 24 has an H-shaped planar shape, and a pair of arm portions facing each other with both openings therebetween functions as a holding portion 24 a for holding the pallet 100 . Both end faces 24b of the exchange arm 24 in the width direction are recessed inward in the width direction in a trapezoidal shape.

Each holding portion 24a of the exchange arm 24 is configured to be engageable with an engagement groove 100a (see FIG. 3) formed at both ends in the width direction of the lower surface of the pallet 100. As shown in FIG. The holding portions 24a positioned on the slide table 7 side of the exchange arm 24 engage both ends of the pallet 100 mounted on the rotary table portion 71 when the slide table 7 is positioned at the moving end in the Z-axis positive direction. It engages with the matching groove 100a. The movement of the slide table 7 to the moving end is automatically executed under the control of the numerical controller 50 after the work W has been machined.

Thus, when the pallets 100 are engaged with the holding portions 24a of the exchange arm 24, and the exchange arm 24 is moved upward by the pallet turning/elevating portion 22, as shown in FIG. After each pallet 100 is held by the portion 24a, the pallet 100 on the rotary table portion 71 is lifted up to the exchange position above the rotary table portion 71, and the pallet 100 on the pallet waiting table 21 is moved to the pallet waiting table 21. is lifted up to the standby position above the Note that the workpiece W is omitted in FIG. 2 for the sake of clarity.

Next, when the exchange arm 24 is turned 180 degrees clockwise in FIG. Then, after both pallets 100 are exchanged between the exchange position and the standby position, when the exchange arm 24 is moved downward by the pallet turning/elevating section 22, both pallets 100 are lifted down and the rotary table section 71 is moved. and placed on the pallet waiting table 21 . Thus, the pallet 100 on the rotary table section 71 and the pallet 100 on the pallet waiting table 21 are exchanged.

In the machine tool 1, the bed 2 and the space above it are surrounded by a cover body 9 (see FIG. 1). , the pallet 100, the workpiece W, and the like are positioned in the space closed by the cover body 9. As shown in FIG. A partition plate 25 is erected on the upper surfaces of the turntable 23 and the exchange arm 24, and below the partition plate 25, a fixed partition plate ( (not shown) is provided, and the space surrounded by the cover body 9 by the partition plate 25 and the fixed partition plate is divided into a processing side area K1 in which the column 3 and the slide table 7 are provided, and a pallet It is separated from the waiting side area K2 in which the waiting table 21 and the like are provided. A pair of notches 25a are formed at the upper end of the partition plate 25 to avoid interference with a camera 26 (see FIG. 4), which will be described later, when the partition plate 25 is turned. The pair of notches 25a are located on both sides of the center of rotation of the partition plate 25 and are formed in a U-shape opening upward.

An opening/closing door 10 for accessing the standby area K2 is provided in a portion of the cover body 9 that forms the wall surface on the Z-axis positive direction side. The operator can attach/detach the work W to/from the pallet 100 on the pallet waiting table 21 via the unit.

As shown in FIGS. 1 and 2, the rotary table section 71 is provided with a total of four seating sections 72 for seating the pallets 100 thereon. The four seating portions 72 are arranged at intervals of 90° in the circumferential direction around the axis of the rotary table portion 71 .

The four seats 72 have positioning and clamping functions for the pallet 100 .
Since the configuration of each seat portion 72 is the same, the configuration of one of them will be described below with reference to FIG.

The seating portion 72 is composed of a seating cylinder 73 fixed to the rotary table portion 71. Inside the seating cylinder 73, a piston 74 for clamping the pallet 100 is accommodated so as to be axially movable. The seating cylinder 73 includes a cylindrical positioning cylinder portion 73a, a truncated cone-shaped flange portion 73b that discharges radially outward from the lower end portion of the positioning cylinder portion 73a, and an inner cylinder connected to the lower surface of the flange portion 73b. It is composed of a cylindrical portion 73c, a bottomed outer cylindrical portion 73d fitted onto the inner cylindrical portion 73c from below, and the like. The positioning cylinder portion 73a is fitted into the positioning hole 101a of the positioning member 101 attached to the lower surface of the pallet 100, thereby positioning the pallet 100 in the horizontal plane. Further, the upper surface 73f of the flange portion 73b abuts against the lower surface of the positioning member 101, thereby positioning the pallet 100 in the height direction.

The piston 74 is a member for switching the pallet 100 positioned by the seating cylinder 73 between a clamped state and an unclamped state via the lock ball 75 . The lock balls 75 are held in respective through-holes 73i radially formed in the positioning cylinder portion 73a of the seating cylinder 73 when viewed from the axial direction, and are configured to move radially forward and backward. The inner peripheral surface of the positioning hole 101a of the positioning member 101 is formed with a lock concave portion 101b with which each lock ball 75 can be engaged.

Then, when the pallet 100 loaded with the unprocessed workpiece W is rotated by the pallet rotating/lifting unit 22 and lifted down onto the rotary table unit 71 , the positioning cylinder 73 of the seating cylinder 73 is inserted into the positioning hole 101 a of the positioning member 101 . 73a is engaged, and the lower surface of the positioning member 101 contacts the upper surface 73f of the flange portion 73b. This completes the positioning of the pallet 100 with respect to the rotary table portion 71 . In this state, when hydraulic pressure is supplied to the lowering hydraulic chamber 73g of the seating cylinder 73, each lock ball 75 is pushed radially outward by the outer peripheral surface of the upper end portion of the piston 74, and formed in the positioning member 101. It fits into the lock recess 101b. As a result, the positioning member 101 is locked so as not to move vertically, and the pallet 100 is fixed to the seating cylinder 73 . On the other hand, when hydraulic pressure is supplied to the rising hydraulic chamber 73h after the pallet 100 is completely fixed, the piston 74 rises and the lock ball 75 is released into the groove 74a formed on the outer peripheral surface of the piston 74 (see FIG. 3). state). As a result, the lock ball 75 is disengaged from the lock recess 101b, so that the positioning member 101 can move upward and the pallet 100 is released.

The camera 26 images the surface of the seating portion 72 (in particular, the outer peripheral surface 73 e of the positioning cylinder portion 73 a and the upper surface 73 f of the flange portion 73 b ) and transmits the image data to the APC control device 30 . The camera 26 is attached to a portion of the cover body 9 that constitutes the ceiling wall of the processing side region K1, as shown in FIG. The optical axis of the camera 26 is coaxial with the axis of the rotary table portion 71 mounted on the slide table 7 when the slide table 7 is moved to the plus side movement end in the Z-axis direction.

The cleaning device 27 is attached to the side of the camera 26 on the ceiling wall (the positive side in the X-axis direction). The cleaning device 27 has a programmable nozzle 27a (hereinafter simply referred to as nozzle 27a) capable of controlling the direction of ejection of the cleaning liquid. In response to a command from the APC control device 30, the cleaning device 27 can spray a cleaning liquid such as a coolant liquid toward the surfaces of the seating portions 72 that require cleaning among the seating portions 72 on the rotary table portion 71. is configured to

As shown in FIG. 5, the APC control device 30 is composed of a computer including a CPU, RAM, ROM, etc., and can send and receive signals to the numerical control device 50, the pallet rotating/lifting unit 22, the camera 26, and the cleaning device 27. It is connected to the.

The APC control device 30 has a drive control section 31, a foreign object detection section 32, and a cleaning control section 33 as functional sections. Processing by each of these functional units is realized by the APC control device 30 executing a computer program.

Specifically, the drive control unit 31 receives a pallet exchange command from the numerical control device 50, and controls the turning actuator and the lifting actuator of the pallet turning/lifting unit 22 to cause the pallet turning/lifting unit 22 to perform a pallet exchange operation. to run. Until the start and end of the pallet exchange operation, the longitudinal direction of the exchange arm 24 faces the Z-axis direction of the machine tool 1, as shown in FIG. 6A. During the pallet exchange operation, the drive control unit 31 controls the pallet 100 loaded with the unprocessed workpieces W to move to an intermediate position between the standby position and the exchange position in order to execute foreign matter detection processing by the foreign matter detection unit 32, which will be described later. (see FIG. 6B), the pivoting motion of the exchange arm 24 is interrupted. In this example, the intermediate position is a position where the pallet 100 that has been in the standby position has turned 90 degrees clockwise in the figure about the turning axis. Note that the pallet waiting table 21 is omitted in FIGS. 6A and 6B for ease of viewing.

The foreign object detection unit 32 causes the camera 26 to capture an image of the surface of each seating portion 72 while the swinging operation of the exchange arm 24 is suspended, and compares the captured image with a reference image. Detects whether foreign matter is attached to the surface of the The reference image is an image of the surface of the seating portion 72 to which foreign matter is not attached, and is stored in advance in a storage unit (not shown). The foreign matter detection unit 32 determines by pattern matching whether or not an image of foreign matter such as scraps exists in a portion corresponding to the surface of the seating portion 72 in the difference image between the captured image and the reference image. The foreign matter detection method is not limited to pattern matching. For example, an image in which a foreign matter is attached to the seating portion 72 and an image in which no foreign matter is attached are input to a computer and machine learning is performed. A learning model for foreign object detection may be generated, and foreign object detection may be performed using the generated learning model. Thus, in this embodiment, the foreign object detection unit 32 and the camera 26 function as a foreign object detection device.

The cleaning control section 33 controls the operation of the cleaning device 27 based on the detection result of the foreign matter detection section 32 . Specifically, when the cleaning control unit 33 acquires from the foreign object detection unit 32 the detection result that the foreign object is attached to the surface of the seating portion 72 , the cleaning control unit 33 determines that the foreign object is attached to the surface of the four seating portions 72 . The position of the seated portion 72 is specified. Then, the cleaning control unit 33 controls the direction of the nozzle 27a to direct the tip of the nozzle 27a toward the specified seating portion 72, and then sprays the cleaning liquid for a predetermined time (for example, 3 to 5 seconds). Here, the direction of the nozzle 27a is preferably set so that the cleaning liquid hits the positioning surface of the pallet 100 in the seating portion 72 (in this example, the outer peripheral surface 73e of the positioning cylinder portion 73a and the upper surface 73f of the flange portion 73b). .

Further, when there are a plurality of seating portions 72 to which foreign matter is detected by the foreign matter detection portion 32, the cleaning control portion 33 sequentially supplies the cleaning liquid to the plurality of seating portions 72 in a predetermined order. do.

Thus, in the machine tool 1 equipped with the pallet changing device 20, when the machining of the workpiece W is completed, the slide table 7 moves to the moving end on the positive side in the Z-axis direction under the control of the numerical controller 50. Then, the pallet 100 on the rotary table portion 71 loaded with the workpiece W after machining is held by the holding portion 24a on the machining area side of the exchange arm 24 (see FIG. 6B). 30 outputs a pallet exchange command.

When the APC control device 30 receives the pallet exchange command from the numerical control device 50 (YES in step S1 in FIG. 7), the drive control unit 31 outputs a command to raise the exchange arm 24 to the pallet turning/elevating unit 22 ( Step S2), thereby, the pallet 100 (first pallet) held by the holding portion 24a on the processing area side of the exchange arm 24 is lifted up to the exchange position and held by the holding portion 24a on the waiting area side of the exchange arm 24. The loaded pallet 100 (second pallet) is lifted up to the standby position.

After that, the drive control unit 31 outputs a command to turn the exchange arm 24 to the pallet turning/lifting unit 22 so that the pallet 100 on which the unprocessed workpiece W is mounted moves to the intermediate position. (Step S3). As a result, the exchange arm 24 temporarily stops at the intermediate position shown in FIG. 6B. Then, after the exchange arm 24 stops at the intermediate position, the captured image from the camera 26 is acquired by the foreign object detection unit 32, and the foreign object detection process described above is executed based on the acquired captured image (step S4). . As a result, if the foreign matter detection unit 32 detects that no foreign matter is attached (NO in step S5), the process proceeds to step S7, where the drive control unit 31 moves the exchange arm 24 to the pallet turning/lowering unit 22. is output (step S7), whereby the replacement arm 24 is rotated from the intermediate position to the replacement position. is output (step S8), the exchange arm 24 is lifted down and the pallet exchange operation is completed.

On the other hand, when the foreign matter detection unit 32 detects that foreign matter is attached (YES in step S5), the cleaning control unit 33 outputs a foreign matter removal command to the cleaning device 27, and as a result, the foreign matter is removed. The cleaning liquid is jetted from the nozzle 27a of the cleaning device 27 toward the attached seat portion 72 for a predetermined time. This cleaning liquid injection process is repeatedly executed until the foreign matter detection unit 32 detects that no foreign matter adheres. Proceeding to S7 and S8, the pallet exchange operation is completed.

As described above, according to the operation method of the pallet exchanging device 20 of the present embodiment, after the pallet 100 on the machining area side on which the workpieces W after machining are loaded is lifted up to the exchanging position by the pallet turning/elevating section 22, , before the pallet 100 on the waiting area side on which the unprocessed workpieces W are loaded is moved from the waiting position to the replacement position and is seated on the seating portion 72 of the rotary table portion 71, the foreign object detection portion 32 detects , the pallet 100 loaded with unprocessed workpieces W is seated on the seating portion 72. Previously, while the cleaning device 27 supplied the cleaning liquid toward the seating portion 72, the cleaning liquid was not supplied when it was detected that no foreign matter adhered.

According to this, foreign matter such as chips adhering to the seating portion 72 of the rotary table portion 71 after the completion of machining of the work W can be removed by the cleaning liquid injected from the cleaning device 27 . Therefore, it is possible to prevent a foreign object from getting caught between the seating portion 72 and the pallet 100 and causing a seating failure. Further, when the foreign matter detection unit 32 detects that no foreign matter is attached to the seating portion 72, the cleaning device 27 does not supply the cleaning liquid. It is possible to improve the energy saving performance and shorten the cycle time.

Further, the foreign matter detection processing by the foreign matter detection unit 32 and the cleaning processing by the cleaning device 27 are repeatedly executed until the foreign matter detection unit 32 detects that no foreign matter is adhered.

As a result, it is possible to reliably prevent the seating operation (lift-down operation) of the pallet 100 from being performed in a state where a foreign object adheres to the seating portion 72 .

(Embodiment 2)
FIG. 8 is a plan view showing the rotary table section 71 of the pallet exchange device 20 according to the second embodiment. This embodiment differs from the first embodiment in the configuration of the cleaning device 27 . In addition, in the following embodiment, the same code|symbol is attached|subjected to the same component as Embodiment 1, and the detailed description is abbreviate|omitted.

That is, in the first embodiment, the cleaning device 27 is configured to be able to change the ejection direction of the cleaning liquid by the programmable nozzle 27a. 27b is adopted.

A total of 12 fixed nozzles 27 b are provided, three for each seating portion 72 . The three fixed nozzles 27b for each seat portion 72 are arranged in the other three regions r1 to r3, excluding one region r4, out of the four regions r1 to r4 equally divided in the circumferential direction with respect to the center position of the seat portion 72. It is arranged to allow the inflow of cleaning liquid. The three fixed nozzles 27b are arranged such that the axes of the adjacent nozzles 27b form an angle of 90° and are offset by the same distance with respect to the equisecting line (two-dot chain line in FIG. 8) passing through the center position of each seating portion 72. It is

The three fixed nozzles 27b cause the cleaning liquid to flow linearly into a position offset from the center position of the seating portion 72, thereby swirling the cleaning liquid around the center position and rotating the rotary table section in the one region r4. It is configured to be able to flow out from the radially inner side of 71 toward the outer side (an example from the inner side to the outer side).

As in the first embodiment, when the foreign matter detector 32 detects that a foreign matter is attached to the seating portion 72, the cleaning device 27 operates under the control of the cleaning controller 33 to While the cleaning liquid is jetted from the nozzles 27b, the jetting of the cleaning liquid from the fixed nozzles 27b is not executed when it is detected that no foreign matter adheres.

Therefore, in the present embodiment, as in the first embodiment, unnecessary operation of the cleaning device 27 can be eliminated to improve energy efficiency and shorten the cycle time. In this example, when it is detected that a foreign substance is attached to the seating portion 72, the cleaning liquid is jetted from all the twelve fixed nozzles 27b. The cleaning liquid may be jetted only from the fixed nozzle 27b corresponding to the seat portion 72 that is positioned.

In addition, in the present embodiment, a swirling flow of the cleaning liquid is generated around each seating portion 72 to blow off foreign matter adhering to each seating portion 72 over the entire circumferential direction. Moreover, the swirling flow of the cleaning liquid flows out from the inner side of the rotary table portion 71 toward the outer side in the one region r4. As a result, it is possible to prevent foreign matter blown away by the swirling flow of the cleaning liquid from adhering again to the seating portion 72 of the rotary table portion 71 .

(Embodiment 3)
FIG. 9 is a view corresponding to FIG. 6B showing the third embodiment. This embodiment differs from the first embodiment in the intermediate position at which the pallet 100 loaded with unprocessed workpieces W is temporarily stopped by the pallet turning and lifting unit 22 .

That is, in the first embodiment, the intermediate position is a position where the pallet 100 loaded with unprocessed workpieces W is turned 90 degrees clockwise from the standby position (see FIG. 7A). In the present embodiment, the position where the pallet 100 is closest to the rotary table portion 71 is set as the intermediate position within a range in which all the seating portions 72 on the rotary table portion 71 are not covered by the pallet 100 from above. Here, the closest position is a position within an angular error of, for example, 0° to 5° with respect to the strictly closest position. In the example of FIG. 9, in order to bring the pallet 100 as close to the rotary table portion 71 as possible at the intermediate position, the widthwise end faces 24b of the exchange arm 24 are recessed more than in the first embodiment.

According to this, it is possible to reduce the time required for restarting the turning operation and moving the pallet 100 to the replacement position after the turning operation by the pallet turning/lifting unit 22 is interrupted, as compared with the first embodiment. Therefore, it is possible to further reduce the time required for pallet exchange while obtaining the same effects as in the first embodiment.

(Other embodiments)
In each of the above-described embodiments, after the movement of the pallet 100 to the intermediate position by the pallet turning and lifting unit 22 is completed, the foreign object detection process by the foreign object detection unit 32 is started, but this is not the only option. Instead, the foreign object detection process may be started before the movement operation to the intermediate position is completed. Specifically, when the pallet 100 loaded with the workpieces W after processing is withdrawn from the rotary table section 71 and all the seating sections 72 are exposed, the camera 26 may be caused to perform the imaging process. According to this operation method, the cycle time can be shortened by starting the foreign object detection process by the foreign object detection unit 32 at the earliest possible timing.

In each of the above-described embodiments, the foreign matter detection unit 32 detects whether or not there is a foreign matter attached to each seating portion 72 based on the image captured by the camera 26, but this is not the only option. For example, an optical sensor may be used to detect the presence or absence of adhesion of foreign matter. Specifically, for example, the surface shape of the seating portion 72 is measured by an optical sensor, and whether or not the optical path between the light emitting portion and the light receiving portion facing each other across the seating portion 72 is blocked by foreign matter is detected. It is conceivable to judge

In each of the above-described embodiments, when the pallet 100 is moved to the intermediate position by the pallet turning/lowering unit 22, the turning operation of the exchange arm 24 is interrupted, and the foreign object detection process is executed by the foreign object detection unit 32 in that state. However, it is not limited to this. The rotation of the replacement arm 24 may be interrupted and the cleaning process by the cleaning device 27 may be performed only when it is detected that there is adhesion.

In each of the above-described embodiments, the cleaning liquid is directly supplied to the positioning surface of the pallet 100 on the seating portion 72 when cleaning by the cleaning device 27. However, the present invention is not limited to this. The cleaning liquid may be supplied to any location as long as it can be removed.

In each of the above-described embodiments, the cleaning device 27 is configured to inject (supply) the cleaning liquid from the outside of the seating portion 72, but the present invention is not limited to this. For example, as shown in FIG. The cleaning liquid may be supplied to the surface of the seating section 72 (in the example of FIG. 10, the upper surface 73f of the flange section 73b of the seating cylinder 73) through a cleaning liquid supply path 73j formed inside the seating section 72.

In each of the embodiments described above, a cleaning liquid such as coolant is used as the foreign matter removing fluid, but the fluid is not limited to this, and a gas such as air may be used.

In each of the above-described embodiments, the rotating pallet exchanging device 20 was exemplified.

In each of the above-described embodiments, an example in which the pallet 100 is mounted on the rotary table section 71 is shown, but the present invention is not limited to this. You may do so. In this case, the slide table 7 corresponds to the processing table.

In each of the above embodiments, a horizontal machining center was exemplified as the machine tool 1 on which the pallet changing device 20 is mounted. In addition, the present invention is not limited to machine tools, and can be applied to devices other than machine tools, such as pallet pool devices.

It should be noted that the above description of the embodiment is illustrative in all respects and is not restrictive. Modifications and modifications are possible for those skilled in the art. The scope of the invention is indicated by the claims rather than the above-described embodiments. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope of claims and equivalents.

r1 other area r2 other area r3 other area r4 one area W workpiece 1 machine tool 20 pallet exchange device 21 pallet waiting table 22 pallet rotating/lifting mechanism (pallet moving/lifting unit)
24 replacement arm (holding member)
26 Camera (foreign object detection device)
27 cleaning device (fluid supply device)
30 APC control device (foreign object detection device)
71 rotary table section (processing table)
72 seating part 100 pallet

Claims (5)

A pallet on which works are loaded is held by a holding member, and the held pallet can be lifted and lowered between a replacement position located above the machining table of the machine tool and a standby position located above the pallet standby stand. A method of operating a pallet changing device having a pallet moving/lowering unit driven to be movable by
A seating portion for the pallet is provided on the upper surface of the processing table,
The pallet exchange device includes a foreign matter detection device capable of detecting foreign matter adhering to the seating portion, and a fluid supply device capable of supplying foreign matter removal fluid to the surface of the seating portion,
After the first pallet, which is loaded with the workpiece and is seated on the seating portion on the processing table, is lifted up to the replacement position by the pallet moving/lowering section after the machining of the workpiece by the machine tool is completed, the It is placed on the pallet standby table by being moved to the standby position and lifted down, while the second pallet, which has been placed on the pallet standby table in advance with the unprocessed workpieces loaded thereon, is called the first pallet. A pallet exchange step of moving to the exchange position by replacement and lifting down after the movement and seating on the seating portion on the processing table to exchange the pallet,
The pallet exchange step includes:
After the first pallet loaded with the processed workpieces is lifted to the replacement position by the pallet moving/lifting unit, the second pallet loaded with the unprocessed workpieces is moved from the standby position to the replacement position. a foreign matter detection step of detecting whether or not a foreign matter is attached to the seating portion using the foreign matter detection device before the seat is seated on the seating portion;
When it is detected that the foreign matter is adhered in the foreign matter detection step, before the second pallet is seated on the seating portion, the fluid supply device supplies the foreign matter removing fluid toward the seating portion. On the other hand, a method of operating a pallet changing apparatus, comprising: a fluid supply step of not supplying the foreign matter removing fluid when it is detected that the foreign matter does not adhere. In the pallet replacement step, when the second pallet reaches an intermediate position before reaching the replacement position, the pallet moving operation by the pallet moving/lowering unit is interrupted. When it is detected that there is no adhesion, the pallet moving operation by the pallet moving elevating unit is resumed, while when it is detected that there is a foreign object adhered in the foreign matter detection step, the pallet by the pallet moving elevating unit The fluid supply step and the foreign matter detection step are repeatedly executed while the moving operation is being interrupted until the foreign matter detection step detects that no foreign matter adheres, and the foreign matter detection step detects that no foreign matter adheres. 2. The operating method according to claim 1, further comprising restarting the pallet moving operation by said pallet moving/lowering unit. 3. The operation according to claim 2, wherein the foreign matter detection step is a step that is started before an operation of moving the second pallet from the standby position to the intermediate position by the pallet moving/lifting unit is completed. Method. 4. The intermediate position is a position where the second pallet comes closest to the processing table within a range in which the seating portion on the processing table is not covered from above by the second pallet. How it works. In the fluid supply step, the foreign substance removing fluid is applied to each of three or more regions equally divided in the circumferential direction with respect to the center position of the seating portion, excluding one region. By allowing the foreign matter removing fluid to flow linearly into a position offset from the position, the foreign matter removing fluid is caused to swirl around the center position and flow out from the inner side of the processing table toward the outer side in the one area. 5. The operating method according to any one of claims 1 to 4, wherein

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