JPH0455814B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for loading or unloading workpieces onto or from the table of a machine tool by exchanging pallets between the machine tool and a predetermined standby position. Relating to a device for

[Background of the invention]

Pallet changing devices of this type are installed, for example, near machine tools. Normally, a pallet is placed on a table of a machine tool with a workpiece fixed thereon, where it is clamped and prepared for cutting. Meanwhile, the next workpiece is waiting on a pallet near the machine tool. At this position,
The pallets are fixed in position on the pallet stand.

Therefore, a positioning mechanism and its driving source are required in this pallet holder.

[Conventional technology]

Conventionally, such positioning mechanisms have been incorporated onto pallet holders. Therefore, a driving source such as a locating pin is required for this pallet holder, which complicates its internal structure and requires special synchronization control to synchronize with the pallet loading/unloading operation.

[Purpose of the invention]

Therefore, an object of the present invention is to provide the necessary functions in connection with the loading/unloading operation of pallets without incorporating a drive source inside such a pallet holder.
That is, it is possible to fix the pallet in a positioned state.

[Means for solving the invention]

Therefore, the present invention provides a cylinder for loading and unloading on the table of the machine tool, and uses the movement of the connecting piece and cam attached to the tip of the cylinder and the table of the machine tool to locate the locate pin provided inside the pallet holder. I like to drive.
That is, the above-mentioned connecting piece engages with a connecting tool attached to the side of the pallet to carry in or take out the pallet, but the cam provided integrally with this connects the connecting piece and the pallet. The engagement and disengagement of the locate pin with the pallet is controlled by driving the movement shaft, rack, and pinion for driving the locate pin through the engagement action with the coupling tool. Therefore, a special drive source for positioning is not required on the pallet table side, and no mechanical control is required to synchronize the loading/unloading operation.

〔Example〕

First, FIGS. 1 and 2 show a machine tool 2 and a pallet holder 3, which are the premises of the pallet changing device 1 of the present invention. This machine tool 2
is equipped with a table 4 movable in the Y-axis direction and the X-axis direction on a plane, and holds a pallet 5 in a fixed state on the table 4. This pallet 5 fixes a workpiece 6 to be processed, and makes it face a spindle 7 movable in the Z-axis direction. Of course, this spindle 7 performs necessary cutting on the workpiece 6 using a tool 8 at its tip.

This table 4 holds a cylinder 9 for loading and unloading at one end, that is, the left side portion in FIGS. 1 and 2. This cylinder 9 is a portion of a piston rod 10 that can move forward and backward in the loading and unloading direction, and holds a connecting piece 11 that can move forward and backward as shown in FIG. This connecting piece 11 has, for example, a T-shaped connecting protrusion 12 that opens in the Y-axis direction, and also integrally forms a chevron-shaped cam 13 at its tip in the X-axis direction. This connecting piece 1
1 can be slidably moved along a guide rod 14 extending in the X-axis direction, and fits into a detent body 15 attached to the table 4 at the forward limit portion. The above connecting protrusion 12
Since the connecting piece 11 is T-shaped, when it is fitted into a connecting tool 17, which will be described later, the connecting piece 11 is prevented from rotating. If there is other rotation preventing means, the shape of the connecting protrusion 12 is not limited thereto.

Although not shown, the table 4 is equipped with guide rollers provided on the upper surface in the loading/unloading direction, and supports the pallet 5 in a movable state by these rollers. The pallet is positioned and fixed at a standard height by the vertical movement of the pallet. Such positioning and fixing mechanisms are similar to those conventionally used.

On the other hand, as shown in FIGS. 3 and 5, the pallet stand 3 has a plurality of trays along the loading/unloading direction in order to hold, for example, two pallets 5 on the upper surface in a movable state in the loading/unloading direction. A guide body, for example a guide roller 16, is supported. These pallets 5 are provided on their sides with connectors 17 that fit into the connecting projections 12 of the connecting pieces 11, as shown in FIGS. 4 and 5, and as shown in FIG.
Locate pin 18 provided on pallet holder 3
A positioning hole 19 is provided at a position corresponding to .

As shown in FIGS. 6 and 7, the locate pin 18 is supported by a bearing 20 attached to the pallet holder 3 so as to be able to move up and down, and is supported by a lower biasing spring 21. It is always biased upward. A rack 22 is formed on the side surface of this locate pin 18, and is engaged with a pinion 24 of an intermediate shaft 23 at this portion. This intermediate shaft 23 is supported by a bearing 25 and is engaged by the other pinion 26 with a rack 28 formed on an interlocking shaft 27. This interlocking shaft 27
As shown in FIGS. 8 and 9, it is slidably held in a non-rotating state by a cylindrical body 29 in the X-axis direction inside the pallet table 3, and the roller 30 corresponds to the cam 13.

A stopper 31 for regulating the position of the pallet 5 is provided on the upper surface of the pallet table 3, and a switch 32 is attached to each of the pallets 5 to detect the unloading state of the two pallets 5. A stopper 33 is also attached to the table 4.

Next, the operation of the invention will be explained along with a series of operations of the pallet exchange device 1.

As is clear, two pallets 5 are already prepared on the pallet stand 3, and one of them will be carried onto the table 4 of the machine tool 2. When carrying pallet 5 onto table 4, first move table 4 to Y.
After moving in the X-axis direction at the center of the shaft stroke, the cylinder 9 is operated for loading and unloading, and its piston rod 10 is advanced, as shown in Fig. 4.
Move it to the detent body 15. In this state, move the table 4 in the Y-axis direction and connect the connecting pieces 11.
The connecting protrusion 12 is made to correspond to the connecting tool 17 of the pallet 5 to be carried in, and the connecting projection 12 is fitted into the connecting tool 17 as shown in FIG. In this way, the connecting piece 11 at the tip of the cylinder 9 becomes connected to the pallet 5 to be transported.

Moreover, when the connecting piece 11 moves in the Y-axis direction, the slope of the cam 13 at the tip changes as shown in FIGS. 9 and 10.
As shown in the figure, the interlocking shaft 27 is in contact with the roller 30.
move in the direction of the arrow. At this time, the movement of the movement shaft 27 in the linear direction is caused by the movement of the pinions 24, 2
6 into a rotational motion, locate pin 1
It is converted into a downward motion of 8. Therefore, the locate pin 18 comes out of the positioning hole 19 of the pallet 5 to be carried in, and sets the pallet 5 in a state where it can move in the carrying direction. Since the connecting tool 17 and the connecting protrusion 12 engage with each other before the locating pin 18 is removed, the pallet 4 is always restricted when the table 4 moves in the Y-axis direction and is not free.

In this way, the movement of the table 4 in the Y-axis direction is
This is the action of engaging the connecting protrusion 12 of the connecting piece 11 with the connecting tool 17 of the pallet 5 to be carried in, and at the same time the action of removing the locate pin 18 from the pallet 5 to be carried in by the cam 13. Therefore,
No special drive source is required on the side of the pallet table 3 to operate the locate pin 18.
Further, this operation is always synchronized with the operation of connecting the connecting piece 11 and the connecting tool 17.

In this state, the cylinder 9 for loading and unloading retreats its piston rod 10 and pulls in the connecting tool 11 in the loading direction, so that the pallet 5 is moved toward the table 4 by the guide roller 16 and the pallet 5 is moved toward the stopper. It hits 33 and stops there. In this state, the pallet fixing mechanism inside the table 4 fixes the carried-in pallet 5 in a positioned state, and prepares it for cutting by the tool 8 of the machine tool 2.

Moreover, when carrying out this pallet 5 to the position of the pallet stand 3, the table 4 is moved along the Y-axis and X-axis directions to the position where it should be carried out,
In this state, the piston rod 10 is moved by the cylinder 9.
By advancing the pallet 5, the pallet 5 is moved from the top of the table 4 to the top of the pallet stand 3. At this time, as the connecting piece 11 moves in the X-axis direction, the tip of the cam 13 hits the roller 30 and presses the interlocking shaft 27, so the locate pin 18 sinks and moves the pallet 5 to a predetermined position. After that, the table 4 places the currently engaged pallet 5 there, moves in the direction of the other pallet 5 to bring in a new pallet 5, and moves the connecting protrusion 12 to a new position. Trough connector 1
Engage with 7. During this time, the locate pin 18 that has been moved above the pallet holder 3 is pushed upward by the biasing spring 21 and fits into the positioning hole 19 of the pallet 5 after being carried out. Also, locate pin 1 below the pallet 5 to be carried in next.
8 is removed from the positioning hole 19 of the pallet 5. In this process, connected piece 1 is added to pallet 5.
1 or the locate pin 18 is always engaged with one of the pallets 5, the movement of the pallet 5 on the pallet table 3 is restricted and it is not free. Note that the ascending and descending states of the locate pin 18 can be detected by the sensor 34 or the like.

〔Effect of the invention〕

In the present invention, when the piston rod of the cylinder for loading and unloading is moved forward and the table moves in the direction of fitting the connecting piece into the connecting tool on the pallet side, or in connection with the unloading operation of the pallet, the cam moves the interlocking shaft. Because the locating pin moves in the direction of entry or exit, a driving source for operating the locating pin is not required on the stand side.
Furthermore, since the movement of the locate pins is reliably synchronized with the loading/unloading operation, it is possible to reliably prevent malfunctions, that is, unnecessary movement of the pallet on the pallet holder side during processing.

[Brief explanation of the drawing]

Fig. 1 is a front view of the machine tool and pallet stand, Fig. 2 is a plan view thereof, Fig. 3 is a plan view of the pallet changing device of the present invention, Fig. 4 is a sectional view of the connecting piece and the connecting tool, Figure 5 is a partially cutaway side view of the pallet holder, Figures 6 and 7 are vertical sectional views of the driving part of the locate pin, Figure 8 is a partial plan view of the connecting piece and the interlocking shaft, and Figure 9 is a partially cutaway side view of the pallet holder. The figure is a sectional view of the connecting piece and the interlocking shaft, and FIG. 10 is a plan view showing the correspondence between the cam and the roller. 1... Pallet exchange device, 2... Machine tool, 3
...Pallet stand, 4...Table, 5...Pallet, 9...Cylinder for loading and unloading, 10...
Piston rod, 11... Connecting piece, 13... Cam, 16... Guide roller, 17... Connecting tool, 18
... Locate pin, 19 ... Positioning hole, 24,
26...Pinion, 27...Interlocking shaft, 28...Rack, 30...Roller.

Claims (1)

[Claims] 1. A machine tool table that can be moved on a flat surface,
A cylinder for loading and unloading is attached at one end of the table facing the loading/unloading direction, a connecting piece fixed to the tip of the piston rod of this cylinder, and a cam formed at the tip of the connecting piece. , a pallet stand provided adjacent to the movement area of the table, a guide provided on the pallet stand in the loading/unloading direction, and a pallet support supported movably in the loading/unloading direction by the guide. a pallet having a connecting tool that fits into the connecting piece;
A locating pin that is provided on the pallet holder so as to be movable up and down and fits into the positioning hole of the pallet, an interlocking shaft that is slidably provided on the pallet holder at a position corresponding to the cam, and the movement of this interlocking shaft. A pallet exchange device comprising a rack and a pinion for transmitting the information to the locating pin.