JPH0620707B2 - Pallet replacement method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pallet changing method most suitable for use in machine tools and the like.

2. Description of the Related Art FMS (Flexible Manufacturing System) has a machine tool body and a pallet changing device. The pallet exchanging device is for exchanging a pallet set on the table of the machine tool and another pallet. Conventional pallet changing methods include a hydraulic cylinder method and a chain drive method.

For example, in the hydraulic cylinder type, by extending the rod of the hydraulic cylinder, one pallet is set on the table of the machine tool. After processing the work on the pallet, the rod is contracted and the pallet is removed from the table.

Further, in the chain drive type, a plurality of pallets are attached to the chain at predetermined intervals. Then, by driving the chain with a motor, an arbitrary pallet is positioned at the table of the machine tool.

In such a conventional method, the pallet is usually exchanged by so-called fast-forwarding or cutting-forwarding.

Problems to be Solved by the Invention However, the pallet and the work are rather heavy. For this reason, when performing pallet replacement with fast feed or cutting feed,
The inertial force is large and the impact is remarkable. Further, the hydraulic cylinder type pallet changing device requires a large hydraulic cylinder. Further, a chain drive type pallet changing device requires a large drive motor and a thick chain. Therefore, in either case, the device becomes large in size and the structure is complicated. For this reason, the impact force when changing the pallet by rapid feed / cutting feed is considerably large,
The machining accuracy of the work set on the pallet becomes poor. In addition, the life of the device itself is shortened.

The object of the present invention is to reduce the impact by smoothly changing the pallet, and without the need for a special large hydraulic cylinder or large motor, the pallet is small in size and has a simple structure, which can significantly reduce the cost. It is intended to provide a replacement method.

SUMMARY OF THE INVENTION This invention has as its gist the pallet exchanging method described in claim 1.

Means for Solving Problems Racks 62 and 63 are provided on the support portion and the pallet 4 for transportation, respectively.
When fixing the pallet and changing the pallet, these racks 6
2, 63 and the first and second pinions 64 and 65 mesh with each other, and further the first pinion 64 and the second pinion 25.
Rotate in conjunction with each other, and the first and second pinions 64, 6
5 is configured to move together with table 2.
The table 2 is slid by the driving means 3 to rotate the first pinion 64 that meshes with the rack 62 fixed to the table, and further to rotate the second pinion 65 that rotates in conjunction with this pinion, thereby carrying the sheet. The rack 63 fixed to the pallet 4 and engaged with the second pinion 65 and the transport pallet 4 are slid relative to the table 2. At this time, the transfer movement of the work transfer pallet 4 is a single string movement, so that the transfer pallet 4 moves smoothly.

Hereinafter, the single string motion means a so-called single-cycle half-cycle motion in which a uniform velocity circular motion is projected for a certain diameter.

Operation The operation will be described with reference to the embodiments for carrying out the present invention. Referring to FIG. Table 2 is in the other direction X2
When moved to, the work transfer pallet 4 is similarly moved in the other direction X2 relative to the table 2 by the moving mechanism 12. Thereby, the work transfer pallet 4 can be moved from the table 2 to another place. (See FIG. 9) In this process, the pallet 4 performs a single-string motion with the starting position being the position of the table 2 fixed and the ending position being the position of the pallet table 30.

Referring to FIG. When the table 2 moves in one direction X1, the work transfer pallet 4 moves in one direction X1 relative to the table 2. As a result, the pallet 4 is set on the table 2. (See Fig. 10)
In this process, the pallet 4 performs a single-string motion with the state of being positioned on the pallet table 30 as a starting point and the state of being positioned at a fixed position on the table 2 as an ending point.

Embodiments Embodiments for carrying out the pallet changing method of the present invention will be described below with reference to the drawings. Please refer to FIG.

A pallet changing device PC for carrying out the present invention has a machine tool supporting portion 1, a table 2, a driving means 3, a work conveying pallet 4, and a moving mechanism 12.

The support 1 is set on the floor. Table 2 is support 1
Is set on. A work transfer pallet (hereinafter referred to as pallet) 4 has a work 5 fixed thereto. The pallet 4 is set to be removable on the table 2 and movable in the X-axis direction.

The driving means 3 moves the table 2 with respect to the support portion 1 in the X-axis direction,
That is, it can move in one direction X1 and the other direction X2. In addition, the moving mechanism 12 has the table 2 in one direction X
The pallet 4 is moved on the table 2 in one direction X1 or in the other direction X2 when moving in the one or the other direction X2.

Please refer to FIG.

FIG. 2 shows a vertical machining center 6 provided with a pallet changing device PC for carrying out the present invention.
The support portion 1 has a bed 7 and a saddle 8. Bet 7
Is equipped with a servo motor 9 (for Y axis).

The drive unit 3 has a servo motor 10 (for X axis) and a ball screw portion 11. Table 2 on the saddle 8
Is set. A pallet 4 is set on the table 2 so as to be removable and movable in the X-axis direction. The moving mechanism 12 is provided near the table 2.

The column 20 of the machining center 6 has a spindle head 21. A tool 23 is attached to the spindle 22 of the spindle head 21. Motor 2
Reference numeral 4 is for rotating the spindle 22. The spindle head 21 has an automatic tool changer 25. Further, the column 20 is provided with a panel 26, a CNC device 27 and a control panel 28.

The table 2 is moved in one direction X by the servomotor 10.
It can be moved in one direction or the other direction X2. A pallet table 30 is provided beside the table 2. Another pallet 14 is placed on the pallet table 30.

Please refer to FIG.

The servomotor 9 has a feed screw 3 of a ball screw portion 33.
4 is attached. The feed screw 34 is engaged with the nut 35. The nut 35 is attached to the lower portion of the saddle 8. Therefore, by operating the servo motor 9, the saddle 8 can be moved in the Y-axis direction. Further, by operating the servo motor 31, the spindle head 21 can be moved up and down in the Z-axis direction. Also in FIG. 3, a part of the moving mechanism 12 described later is shown.

Please refer to FIG. 4 and FIG.

The pallet table 30 can set the pallets 4 and 14 side by side. A work 5 is fixed to each of the pallets 4 and 14. The pallet table 30 has two air cylinders 40 and 41 built therein. Air cylinder 4
0 and 41 have stopper pins 42 and 43, respectively. The stopper pins 42 and 43 are respectively pallets 4 and 1
It can be fitted in the holes 44 and 45 of No. 4. This prevents displacement of the pallets 4 and 14. When moving the pallets 4 and 14, this stopper pin 4
2 and 43 come out of the holes 44 and 45 by contracting. A rack 63 is fixed to the lower part of the pallet 4 along the longitudinal direction. A rack 91 is also fixed to the lower part of the pallet 14 along the longitudinal direction.

Both ends of the rack 63 project from the left end and the right end of the pallet 4, respectively. Further, both ends of the rack 91 also protrude from the left end and the right end of the pallet 14, respectively.

6 and 7, a saddle 8, a table 2, a pallet 4 also called a pallet table, and a moving mechanism 12 are shown. In FIG. 6, the pallet 4 is clamped on the table 2. In FIG. 7, the pallet 4 is unclamped.

The table 2 has a slide portion 50, two clamp cylinders 51, and a clamp plate 53. Clamp cylinders 51, 51 are fixed on the slide portion 50. One clamp cylinder 51 is located behind the other clamp cylinder 51 and is therefore not shown in FIGS. 6 and 7. A clamp plate 53 is fixed to the rod 52 of the clamp cylinder 51. A nut 54 is fixed to the lower surface of the slide portion 50. The feed screw 55 of the ball screw portion 11 is engaged with the nut 54. The feed screw 55 is connected to the servomotor 10.

The pallet table 4 has parts 56, 56 and a cover 57.
have. The cover 57 is provided in order to prevent chips and cutting oil from being applied to the rack 62 and the first pinion 64. The parts 56, 56 are adapted to contact the lower surface of the clamp plate 53.

The moving mechanism 12 includes a gear housing 61, racks 62, 6
3 and a support 67 for the rack 62. The lower end of the support body 67 is fixed to the front surface of the saddle 8. The gear housing 61 has shafts 68 and 69. Axis 68
The first pinion 64 is fixed to one end of the. A gear 66 is fixed to the other end of the shaft 68. Axis 69
The 2nd pinion 65 is being fixed to this. The gear housing 61 is fixed to the clamp plate 53.

As shown in FIGS. 6 and 7, the gear 66 always meshes with the second pinion 65. In FIG. 6, that is, when the pallet 4 is clamped, the rack 63 and the second pinion 65 are not meshed, and the rack 62 and the first pinion 64 are not meshed. On the other hand, in FIG. 7, that is, when the pallet 4 is unclamped, the rack 6
3 and the second pinion 65 mesh with each other, and the rack 62 and the first pinion 64 also mesh with each other.

In FIG. 6, the rod 52 of the clamp cylinder 51 is contracted, and the clamp plate 53 holds the pallet 4 in the pin 8 position.
It is clamped at 0,81. The clamping is performed when the work 75 is processed by the tool 23 (see FIG. 2).

In FIG. 6, the rod 5 of the clamp cylinder 51 is shown.
The clamp plate 53 releases the clamp of the pallet 4 by extending 2 upward. At the same time, as shown in FIG. 7, the first pinion 64 engages with the rack 62. The second pinion 65 engages with the rack 63.
The unclamping is performed when the pallet 4 is transferred from the table 2 to the pallet table (see FIG. 2).

Referring to FIG.

In FIG. 8, the pins 80 and 81 described above are provided on the slide portion 50 of the table 2. This pin 80,8
1 functions as a seating surface of the pallet 4 and a positioning pin. That is, when the pallet 4 is at the fixed position on the table 2, the upper ends of the pins 80 and 81 are fitted in the shallow holes 56a of the portions 56 and 56, respectively. The slide portion 50 is movable along the rails 70 and 71 of the saddle 8.

In FIG. 9, the pallet 4 is located on the pallet table 30. In this case, the table 2 has moved to the right end of the saddle 8. The second pinion 65 of the moving mechanism 12 is engaged with the left end or the tip of the rack 63. The first pinion 64 meshes with the right end or the tip of the rack 62.

In FIG. 9, the servo motor 10 is operated to move the table 2 in the first direction X1. The table 2 and the gear housing 61 move together in one direction X1. In this case, of course, as shown in FIG.
Is in an unclamped state, and the first pinion 64
And the rack 62 mesh with each other, and the second pinion 65 and the rack 63 also mesh with each other. The fact that the table 2 moves in one direction X1 in FIG. 9 means that the table 2 moves downward in the drawing in FIG. Therefore, the first pinion 64 rotates in the r1 direction while engaging with the rack 62. This rotation causes the second pinion 65 to rotate in the r2 direction. Due to the rotation of the second pinion 65, the pallet 4 moves on the table 2 in the same direction as the slide portion 50 of the table 2, that is, one direction X1 (see FIG. 9).

As a result, the state shown in FIG. 10 is obtained. That is, the pallet 4 is set at a fixed position on the table 2.

In this process, the pallet performs a single string motion starting from the state of being positioned on the pallet table 30 (Fig. 9) and ending at the state of being positioned at the fixed position of the table 2 (Fig. 10).
The servo motor 10 is operated. This single string movement is CN
The C device 27 performs machine lock on the Y axis by using the M function (auxiliary function), and further circularly interpolates G02 on the X and Y axes.
Alternatively, it can be easily realized by performing G03.

Referring again to FIG. 6, the rod 52 of the clamp cylinder 51 is contracted to clamp the pallet 4 on the table 2. This separates the first pinion 64 from the rack 62. The work 5 is processed in this state.

This processing is performed in the usual way using the tool 23 shown in FIG. For example, a drill hole is drilled in the work 5.

Referring again to FIG. 7, after the work 5 is processed, the rod 52 of the clamp cylinder 51 is extended to extend the pallet 4
Release the clamp. Thereby, the first pinion 6
4 reengages rack 62.

Next, referring to FIG. The servo motor 10 is driven to move the table 2 in the other direction X2. In this case, as shown in FIG. 7, the pallet 4 is in an unclamped state, the first pinion 64 and the rack 62 are engaged with each other, and the second pinion 65 and the rack 63 are also engaged with each other.
The movement of the table 2 in the other direction X2 in FIG. 10 means that the table 2 moves in the other direction X2 in FIG.
Move to the front of the figure. Therefore, the first pinion 64 rotates in the rack 62 in the r3 direction. Therefore, the second pinion 65 rotates in the r4 direction. Therefore, the pallet 4 also moves on the table 2 in the same direction as the slide portion 50 of the table 2, that is, the other direction X2 (see FIG. 10). As a result, when the table 2 moves to the right end of the saddle 8 as shown in FIG. 9, the pallet table 4 is moved again onto the pallet table 30.

In this way, the setting of the pallet 4 on the table 2, the processing of the work 5, and the transfer of the pallet 4 from the table 2 can be performed in order.

In this process, the pallet 4 performs a single string motion with the starting point being the state (FIG. 10) located at the fixed position of the table 2 and the ending point being the state (FIG. 9) located on the pallet table 30. The servo motor 10 is operated. This single string movement is
The CNC device 27 uses the M function (auxiliary function) for the Y axis to perform machine lock, and further circular interpolation G for the X and Y axes.
It can be easily realized by performing 02 or G03.

Next, setting of the palettes 4 and 14 on the table 2 will be described with reference to FIGS. 11 to 17.

In FIG. 11, both pallets 4 and 14 are on the pallet table 30 and the table 2 is initially set at the position IP. The table 2 moves in the other direction X2, and then moves in the Y1 direction.

Thereby, as shown in FIG. 12, the pinion 65 of the table 2 is engaged with the tip of the rack 63 of the pallet 4. Then, the table 2 is moved in one direction X1. In this process, the pallet 4 performs the single string movement as described above.

Referring to FIG. 13, the pallet 4 is set on the table 2. The table 2 is located at the processing position P1. At this time, the spindle head 21 shown in FIG. 2 is lowered and a hole H is formed in the work 5 by the tool 23.

Referring to FIG. 14, the table 2 moves to another position SP after processing. Then, the table 2 moves in the other direction X2. At this time, the pallet 4 is moved along with the movement of the table 2.
Also moves on the table 2 in the other direction X2. In this process, the pallet 4 performs a single string movement.

Referring to FIG. 15, the pallet 4 is returned to the pallet table 30.

Referring to FIG. Move table 2 in the Y2 direction. As a result, the pinion 65 of the table 2 is moved to the rack 63.
Engage with the removal rack 91. Then, the table 2 is moved in one direction X1. At this time, table 2
As the pallet 14 moves on the table
Move to 1. In this process, the pallet 4 performs a single string movement.

Referring to FIG. The table 2 is moved to the processing position P1, the spindle head 21 shown in FIG.
The work 5 is processed by.

In this way, the pallets 4 and 14 are sequentially set on the table 2 and the works 5 and 5 are processed.

Next, another embodiment will be briefly described with reference to FIG. In the vertical machining center described above, a plurality of pallets are installed on a pallet stand beside the machining center. In this case, a plurality of pallets can be exchanged by moving the table in the X-axis direction. On the other hand, in this embodiment, the vertical machining center 10
A pallet table is provided on the front side of 6, and a plurality of pallets 104 and 114 are installed on this pallet table via a pallet table 130. In FIG. 18, one pallet 104 is located on the table 102. The moving mechanism 112 is Y
It is installed in the axial direction, and a plurality of pallets are exchanged by moving the table 102 in the Y-axis direction. In the pallet exchange, the pallet performs a single string motion as in the previous example.

The present invention is not limited to such an embodiment. For example,
A pallet base may be placed beside the horizontal machining center and a plurality of pallets may be installed on the pallet base. In this case, a plurality of pallets can be exchanged by moving the table in the X-axis direction. The pallet is exchanged so that the pallet moves in a single string. Further, a method may be adopted in which a pallet table is placed in front of the horizontal machining center and a plurality of pallets are installed on this pallet table. In this case, a plurality of pallets can be exchanged by moving the table in the Z-axis direction. Also in this case, the pallet is exchanged so that the pallet moves in a single chord.

Furthermore, the number of pallets is not limited to two and may be more.

Further, the pallet exchanging method of the present invention is not limited to the machine tool described above, but can be applied to a table feeding method for general industrial machines such as automatic tool assembling machines using X and Y tables.

Further, in the first embodiment, the table 2 is moved in the Y-axis direction so that the table 2 is made to correspond to the pallets 4 and 14 in order.
However, the pallets 4 and 14 on the pallet table 30 may be moved (in the Y-axis direction) with respect to the table 2.

EFFECTS OF THE INVENTION As is clear from the above description, since the pallet performs a single string motion during the pallet exchange process, the pallet is smoother than the conventional pallet exchange by fast feed or cutting feed. Acceleration / deceleration is performed, so the impact can be reduced. Therefore, the fixed position of the work on the pallet is accurately maintained, and extremely accurate processing can be performed. In addition, the life cycle of the apparatus main body is lengthened by performing the smooth pallet exchange according to the present invention.

Further, according to the present invention, since the pallet is moved in the same direction as the table through the moving mechanism by using the driving force of the table driving means, a large hydraulic cylinder and a large motor are not separately required, and a small size is achieved. Can simplify the structure. And a significant cost reduction can be achieved.

Further, if the moving mechanism is provided with a rack and a pinion and the rack and the pinion are mechanically disengaged when the pallet is clamped on the table, the position of the pallet with respect to the table does not shift even if the table is moved during processing.

Also, the feed screw is not burdened. Therefore, it is possible to simplify the electric circuit without the need for a limit switch for interlock.

[Brief description of drawings]

FIG. 1 is a schematic view showing a pallet changing device for carrying out the pallet changing method of the present invention, and FIG. 2 is a front view showing a machining center equipped with the pallet changing device for carrying out the pallet changing method of the present invention. 3 is a side view of the machining center, FIG. 4 is a plan view showing a pallet base,
5 is a perspective view showing a pallet base, FIG. 6 is a sectional view taken along line AA in FIG. 2 showing a state where the pallet is clamped on a table, and FIG. 7 is an unclamped state of the pallet. FIG. 8 is a sectional view taken along the line BB of FIG. 2, FIG. 8 is a sectional view taken along the line BB of FIG. 2, FIG. 9 is a front view showing a state where the pallet is not placed on the table, and FIG. 11 is a front view showing a state, FIG. 11 to FIG. 17 are views showing a pallet changing operation, and FIG. 18 is a plan view briefly showing another example of a machining center for carrying out the pallet changing method of the present invention. is there. PC ...... Pallet changer 1 ...... Support part 2,102 ...... Table 3 ...... Driving means 4,14,104,114 ...... Work transfer pallet 5 ...... Work 6 ...... Machining center 7 ...... Bet 8 ...... Saddle 9,10 Servo motor 12,112 Moving mechanism 20 Column 21 Spindle head 23 Tool 30,130 Pallet stand 50 Slide part 51 Clamp cylinder 53 Clamp plate 61 ... Gear housing 63, 91 ... Rack 64, 65 ... Pinion 66 ... Gear

Claims (4)

[Claims] 1. A pallet exchanging method for transporting a work transporting pallet located at a place different from the table onto a table which is movable in at least one axial direction, and a rack is provided on each of the support portion and the transporting pallet (4). (62, 63)
When fixing the pallet and replacing the pallet (6
2, 63) and the first and second pinions (64, 65) mesh with each other, and further, the first pinion (64) and the second pinion (65) rotate together, and the first and second pinions (64) rotate. Of the first pinion (64, 65) which moves together with the table (2), and the table (2) is slid by the drive means (3) to engage with the rack (62) fixed to the table. 64) rotate
Further, by rotating the second pinion (65) that rotates in conjunction with this pinion (64), the rack (63) fixed to the transfer pallet (4) and engaged with the second pinion (65) and the transfer pinion (65) A pallet exchanging method characterized in that the pallet (4) is slid relative to the table (2), and that the work transfer pallet (4) is moved in a single-string motion. 2. The driving means comprises a ball screw portion actuated by a servomotor, a nut of the ball screw portion is fixed to a table, and a feed screw of the ball screw portion is connected to a servomotor. A nut is fed by driving a motor to rotate a feed screw and further drives a table.
The pallet replacement method described in item. 3. The pallet changing method according to claim 1, wherein the table is movable in another uniaxial direction orthogonal to the uniaxial direction. 4. The pallet changing method according to claim 1, wherein the engagement between the rack and the first and second pinions is disengaged when the work transfer pallet is clamped on the table. .