JPH07110464B2 - Automatic pallet changing system - Google Patents

Description

TECHNICAL FIELD The present invention relates to an automatic pallet changing system. More specifically, it relates to an automatic pallet exchange system for transferring and exchanging pallets between a machine tool side and a pallet conveying means such as a conveyor.

[Prior Art] In a normal machining system for machining a workpiece with a plurality of NC machine tools such as FMS, a pallet changer is installed between a pallet conveyor that conveys pallets and the NC machine tool. Many. Pallet changers are roughly classified into swivel type and parallel type. The swivel type
The pallet loaded with the unprocessed workpiece received from the conveyor (hereinafter referred to as the unprocessed pallet) is rotated and supplied to the NC machine tool side, and at the same time, the processed workpiece from the NC machine tool side. The pallet loaded with (hereinafter, referred to as a processed pallet) is returned to the conveyor.

In the parallel type, unprocessed and processed pallets are placed in parallel along the machine tool, and when the processing is completed, the processed pallet is received and then the unprocessed pallet is supplied to the NC machine tool.

[Problems to be Solved by the Invention] In recent years, there is a strong demand for shortening the machining time as much as possible, that is, for higher efficiency. In order to realize highly efficient machining, it is necessary to shorten the machining cycle as much as possible. In order to shorten the machining cycle, it is necessary not only to improve the machining speed but also to shorten the cycle time other than the actual machining time such as the pallet replacement time.

Pallet exchange time should be as short as possible. However, in the conventional method, since the pallet changing device does not move, the operation of moving the pallet from the pallet clamp part of the machine tool to the pallet changing device and the operation of moving the pallet from the pallet changing device to the pallet clamp part of the machine tool are pallet changing operations. There is a limit to shortening the cycle time because it comes before and after. The present invention has been invented in such a technical background, and achieves the following objects.

An object of the present invention is to provide an automatic pallet changing device with a short pallet changing time.

Another object of the present invention is to provide an automatic pallet changer capable of directly reversing a pallet on a table of a machine tool.

[Means for Solving the Problems] In order to solve the problems, the following means are adopted.

A first means is a machine tool and an automatic pallet changing system provided on a base (10) for supplying / discharging a pallet having a workpiece mounted on the machine tool, which is a rotary drive source. A reciprocating drive motor (14), and a reciprocating drive device (18) for controlling the rotation of the reciprocating drive motor (14) and outputting the rotation of the gear (19) for indexing 3 positions in 2 sections, A carriage having a rack (20) meshing with the gear (19) fixed, an exchange arm drive box (9) mounted thereon, and a reciprocating drive device (18) reciprocatingly driving the base (10) to three positions. (11), confirmation means (21, 22) for confirming the three positions of the carriage (11), and a cam follower (41) rotatably provided in the exchange arm drive box (9). With roller gear cam (36) for driving A side cam (37) that is rotationally driven in conjunction with the roller gear cam (36) to swing the swing lever (44).
And mounted on the carriage (11), the cam follower (4
1) The pallet exchanging arm (30) for exchanging the pallet and the roller gear cam (36) and the side cam (37) are rotationally driven by being rotated by the swing lever (44) and vertically driven by the swing lever (44). The automatic pallet changing system is characterized by comprising an arm drive motor (31) for

The reciprocating drive device (18) is a roller cam that shifts to a speed characteristic of a modified sinusoidal curve and outputs to the output gear (19) in order to stop and move the carriage (11) to the three positions. It is an automatic pallet changing system.

A second means is a machine tool and an automatic pallet changing system provided on a base (10) for supplying and discharging a pallet having a workpiece mounted thereon to the machine tool, which is a rotary drive source. A motor (90), a reciprocating drive device (91, 96) for changing the rotation of the motor (90) and outputting the rotation of a gear (100) for indexing 3 positions in 2 sections, The rack (20) that meshes with (100) is fixed,
And a carriage (11) on which an exchange arm drive box (9) is mounted and which is reciprocally driven on the base (10) by the reciprocating drive device (91, 96) to three positions; Confirmation means (21, 22) for confirming 3 positions, and a cam follower (41) driven by the drive motor (90) and rotatably provided in the exchange arm drive box (9). Roller gear cam (36) for driving, and a side cam (37) for rotationally driving the rocking lever (44) in conjunction with the roller gear cam (36).
And mounted on the carriage (11), the cam follower (4
1) The pallet exchanging arm (30) for exchanging the pallet, which is swung by the swing lever (44) and is vertically moved by the swing lever (44), and power transmission from the drive motor (90) for the carriage ( 1
The automatic pallet exchange system is characterized in that it comprises a clutch means (93, 94) for switching the movement to the 3 position or the pallet exchange operation of 1).

[Operation] The unprocessed pallet P2 is waiting in the automatic pallet changing device 4. Other raw pallets are also temporarily stopped on the supply conveyor. When the machining of the pallet in the machine tool is completed, the automatic pallet changer moves to the work table side, and the pallet changer arm of the automatic pallet changer grips the pallet and lifts the pallet from the work table to 180 degrees. Turn and lower. A raw pallet is placed on the work table. The automatic pallet changer retracts to the supply conveyor side, and the new pallet is processed.

The automatic pallet changing device transfers the processed pallet to the side of the supply conveyor.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.
1 (a) to 1 (g) are flow charts showing a schematic operation sequence of the automatic pallet changing device 4, the supply conveyor 1 and the discharge conveyor 2. Supply conveyor 1 and discharge conveyor 2
And are arranged in parallel. A supply conveyor 1 and a work table 3 of an NC machine tool are arranged at a distance. An automatic pallet changing device 4 is installed between the work table 3 and the supply conveyor 1. The escapement 5 temporarily stops the movement of the pallets so that one or more standby pallets are not transferred between the stations.

The escapement 5 is swung about the axis by the force of a solenoid (not shown). The direction changing conveyor 6 is a transfer means for transferring the pallet from the supply conveyor 1 to the discharge conveyor 2. The operation sequence of this automatic pallet changing system will be described below. The detailed structure of the automatic pallet changing device 4 will be described later. This automatic pallet changer 4
It has a twin-fork type pallet exchange arm 30 that holds a pallet at both ends.

The pallet P1 in FIG. 1 (a) is a pallet that is placed on the work table 3 and is processing a workpiece. The unprocessed pallet P2 is waiting in the automatic pallet changing device 4. The raw pallet P3 is temporarily stopped on the supply conveyor 1 by the escapement 5. When the processing of the work piece of the pallet P1 is completed, the automatic pallet changing device 4 moves to the work table 3 side, the pallet changing arm 30 holds the pallet P1 and lifts the pallet P1 from the work table 3. Turn 180 degrees.

An unprocessed pallet P2 is placed on the work table 3 (FIGS. 1 (b) to (c)). The automatic pallet changing device 4 is retracted to the intermediate standby position, and the NC pallet machine starts processing the workpiece on the new pallet P2 (the same (d)). At the intermediate standby position, the automatic pallet exchange device 4 raises the pallet exchange arm 30 to transfer the processed pallet P1 onto the supply conveyor 1 side. The pallet exchange arm 30 descends on the supply conveyor 1 side to place the pallet P1 on the supply conveyor 1, and at the same time, the stopper 7 on the direction changing conveyor 6 side is projected (the same (e)).

At the same time, when the escapement 5 is opened and the unprocessed pallet P3 is released, the processed pallet P1 is moved on the supply conveyor 1.
And the unprocessed pallet P3 are transferred, the processed pallet P1 is stopped on the direction changing conveyor 6 by the stopper 7, and the unprocessed pallet P3 is the pallet exchanging arm of the automatic pallet exchanging device 4.
Stop at 30 (same (f)). Next, the pallet exchanging arm 30 of the automatic pallet exchanging device 4 rises, holds the unprocessed pallet P3, transfers it to the intermediate standby position, and stands by. The processed pallet P1 is transferred on the side of the discharge conveyor 2 by the direction changing conveyor 6 (the same (g)).

Automatic Pallet Changing Device FIG. 2 is a front view of the automatic pallet changing device 4, and FIG. 3 is a right side view. The base 10 is a frame that forms a rectangular parallelepiped immovable main body on the floor. base
Two guide surfaces 12 are formed on the upper surface of 10. A carriage 11 is movably provided on the guide surface 12. The exchange arm drive box 9 is mounted on the carriage 11. A cam / lever mechanism, which will be described later, for turning the pallet changing arm 30 up and down and 180 degrees is built in the changing arm drive box 9.

Further, a reciprocating drive device 18 for moving the carriage 11 is incorporated in the base 10. A motor 14 is installed on the bottom surface of the base 10. A pulley 15 is fixed to the output shaft of the motor 14. A V-belt 16 is stretched around the pulley 15. On the other hand, the V-belt 16 has a pulley
It has also been passed over to 17. The pulley 17 is a reciprocating drive device 18
Is connected to the input shaft of. The reciprocating drive device 18 has a roller cam type 180-degree indexing device built-in.
The rotation of 4 is changed to the speed characteristic of the modified sinusoidal wave and output to the output gear 19.

The indexing of the output gear 19 of the reciprocating drive device 18, namely 180
Rotation of the carriage 11 causes the carriage 11 to move one pitch (a to b, b) at the stop position.
(Between c and c) (see FIG. 2). Therefore, to move from the position a to the position c, the output gear 19 is indexed and the speed is controlled so that the output gear 19 starts to move smoothly at each pitch and stops smoothly.

The gear 19 meshes with a rack 20 provided on the lower surface of the carriage 11. Therefore, when the gear 19 is rotated, the carriage 11
Reciprocates on the guide surface 12. 3 on the side of carriage 11.
Proximity sensors 21 are provided (see Fig. 3). Corresponding to the mounting position of the proximity sensor 21, the dog 22 is the base 10
It is fixed on. The exchange arm drive box 9 is eventually selectively stopped in three positions. The first position is a position a close to the work table 3, an intermediate standby position, that is, a position b for waiting for the next operation, and a position c close to the supply conveyor 1.

The three dogs 22 correspond to these three positions. When the carriage 11 moves to each position, the proximity sensor 21 detects the position of each dog 22, and after confirming the position of the carriage 11, the operation of the pallet changing arm 30 and the opening / closing operation of the splash cover (not shown) are started. Let

Exchange Arm Drive Box FIGS. 4, 5 and 6 show the vertical and swing drive mechanisms of the pallet exchange arm 30. FIG. 4 is a sectional view of the exchange arm drive box,
5 is a sectional view taken along line VV in FIG. 4, and FIG. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7 is a cam operating diagram. An arm drive motor 31 is attached to the box-shaped replacement arm drive box 9. A pulley 32 is keyed to the output shaft of the arm drive motor 31. The pulley 32 has a toothed belt
33 is belted and transmits the driving force to the pulley 34. The pulley 34 is keyed to the shaft 35.

The shaft 35 is rotatably provided on the exchange arm drive box 9, and a roller gear cam 36 and a side cam 37 are key-connected to the shaft 35. A spiral spiral groove 36a is formed on the outer periphery of the roller gear cam 36, and a side surface groove 37a is formed on the side surface of the side surface cam 37. A roller of a cam follower 41 fixed to the turret 40 is engaged with the spiral groove 37a. Turret 40
A female spline is formed on the inner periphery of the spline shaft.
42 engaged. The spline shaft 42 is constantly urged upward in the axial direction by a spring 48 with respect to the exchange arm drive box 9. The pallet exchanging arm 30 is fixed to the upper portion of the spline shaft 42. When the roller gear cam 36 is rotated by the rotational driving force of the arm driving motor 31, the pallet exchanging arm 30 is rotated via the turret 40 and the spline shaft 42.
Turns.

A shifter 43 is keyed to the center of the spline shaft 42. In the groove portion 43a of the shifter 43, a cam follower 45 provided at the tip of a swing lever 44 that swings around a support shaft 46 rotatably supported by the exchange arm drive box 9.
Engage. A cam follower 47 is provided at the center of the swing lever 44 and engages with the side surface groove 37a of the side surface cam 37. The shifter 43 moves up and down together with the spline shaft 42 in the axial direction of the spline shaft 42 by the side surface groove 37a with the support shaft 46 as a fulcrum by the side surface cam.

The relationship between the cam shape curves of the roller gear cam 36 and the side surface cam 37 is that, as shown in FIG.
The pallet exchange arm 30 is operated in the order of turning and lowering.

Operation of Automatic Pallet Changer 4 Next, the vertical and swivel operation of the automatic pallet changer will be described according to the mechanism. When the arm drive motor 31 starts rotating, the pulley 32, the toothed belt 33, and the pulley 34 are driven to rotate. When the pulley 34 rotates, the shaft 35, the roller gear cam 36, and the side surface cam 37 rotate. Roller gear cam 36
And the cam shape of the side cam 37 is as shown in Fig. 7,
First, the swing lever 44 rotates along the side surface groove 37a of the side surface cam 37, and the spline shaft 42 is raised via the shifter 43.

Next, the spline shaft 42 turns along the spiral groove 36a of the roller gear cam 36. Then, the spline shaft 42 descends along the side surface groove 37a. The pallet of the workpiece table 3 or the supply conveyor 1 and the pallet in the pallet exchanging arm 30 are exchanged by the pallet exchanging arm 30 which performs the vertical and swiveling operations.

Other Embodiments In the above-described embodiments, the drive motor for driving the pallet exchanging arm 30 and the drive motor for the carriage 11 are separate motors. 8 and 9 show an embodiment using one motor. FIG. 8 is a side view, and FIG. 9 is a partially cut plan view. The output shaft of the motor 90 is keyed to the shaft 91. A gear 92 is fixed to the shaft 91.

The gear 92 is connected to the drive mechanism of the pallet changing arm 30. On the other hand, electromagnetic clutches 93, 94 are connected to the shaft 91. The clutch 93 is for connecting / disconnecting the gear 92 to drive the pallet changing arm 30. The clutch 94 is for driving the output of the shaft 91 to drive the carriage 11. The output of the clutch 94 is transmitted to the input shaft 95, and the rotation of the input shaft 95 is input to the speed reducer 96. Decelerator
The output of 96 is transmitted to pulley 99 via pulley 97 and toothed belt 98.
Be transmitted to.

The pinion 100 is fixed coaxially with the pulley 99. Since the pinion 100 meshes with the rack 20, the carriage 11
To reciprocate. In this embodiment, the operation of the automatic pallet changing device 4 can be performed by one motor.

[Effects of the Invention] As described in detail above, the present invention can significantly reduce the pallet replacement time. Further, it is possible to reduce the driving sources of the pallet exchanging arm and the carriage having the pallet exchanging arm. Moreover, since the cam mechanism is adopted, the structure and control are simplified.

[Brief description of drawings]

1 (a) to 1 (g) are operation sequence diagrams showing the operation sequence of the automatic pallet changing device, the supply conveyor, and the discharge conveyor,
2 is a front view of the automatic pallet changing device, and FIG. 3 is a second view.
FIG. 4 is a right side view, FIG. 4 is a cut front view of the automatic pallet changing device, FIG. 5 is a sectional view taken along line VV of FIG. 4, and FIG. 6 is a sectional view taken along line VI-VI of FIG. FIG. 7 is a development view showing cam shapes of a roller gear cam and a side cam, FIG. 8 is a front view of an automatic pallet changing device showing another embodiment, and FIG. 9 is a automatic pallet changing device showing another embodiment. It is a partially cut plan view. 1 ... Supply conveyor, 2 ... Discharge conveyor, 3 ... Work table, 4 ... Automatic pallet changing device, 5 ... Escapement, 6 ... Direction changing conveyor, 7 ... Direction changing stopper, 8 ... Stopper, 9 …… Exchange arm drive box, 10 …… Base, 11 …… Reciprocator, 12 …… Guide surface,
14 …… Motor, 18 …… Reciprocating drive, 30 …… Pallet exchange arm

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akio Miura 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (72) Toshimitsu Abe 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. ( 56) References JP-A-61-244440 (JP, A)

Claims (3)

[Claims] 1. A machine tool, and an automatic pallet changing system provided on a base (10) for supplying / discharging a pallet having a workpiece mounted on the machine tool, the reciprocating drive source being a rotary drive source. A drive motor (14); a reciprocating drive device (18) for controlling the rotation of the reciprocating drive motor (14) and outputting the rotation of a gear (19) for indexing three positions in two sections; A rack (20) that meshes with a gear (19) is fixed, an exchange arm drive box (9) is mounted, and a reciprocating base (10) is reciprocally driven to three positions on the base (10) ( 11), confirmation means (21, 22) for confirming the three positions of the carriage (11), and rotatably provided in the exchange arm drive box (9) to drive the cam follower (41). Roller gear cam (36) for A side cam (37), which is rotationally driven in conjunction with the roller gear cam (36), to drive the swing lever (44).
And mounted on the carriage (11), the cam follower (4
1) The pallet exchanging arm (30) for exchanging the pallet and the roller gear cam (36) and the side cam (37) are rotationally driven by being rotated by the swing lever (44) and vertically driven by the swing lever (44). An automatic pallet changing system, which comprises an arm drive motor (31) for 2. The output gear (1) according to claim 1, wherein the reciprocating drive device (18) shifts to a speed characteristic of a modified sinusoidal curve in order to stop and move the carriage (11) to the three positions. An automatic pallet changing system characterized by a roller cam output to (19). 3. A machine tool, and an automatic pallet changing system provided on a base (10) for supplying / discharging a pallet having a workpiece mounted on the machine tool, the motor being a rotary drive source. (90), a reciprocating drive device (91, 96) for changing the rotation of the motor (90) and outputting the rotation of the gear (100) for indexing two positions and three positions, and the gear ( The rack (20) that meshes with 100) is fixed,
And a carriage (11) on which an exchange arm drive box (9) is mounted and which is reciprocally driven on the base (10) by the reciprocating drive device (91, 96) to three positions; Confirmation means (21, 22) for confirming 3 positions, and a cam follower (41) driven by the drive motor (90) and rotatably provided in the exchange arm drive box (9). Roller gear cam (36) for driving, and a side cam (37) for rotationally driving the rocking lever (44) in conjunction with the roller gear cam (36).
And mounted on the carriage (11), the cam follower (4
1) The pallet exchanging arm (30) for exchanging the pallet, which is swung by the swing lever (44) and is vertically moved by the swing lever (44), and power transmission from the drive motor (90) for the carriage ( 1
An automatic pallet exchanging system comprising: clutch means (93, 94) for switching to the movement of 1) to the three positions or the pallet exchanging operation.