JPH0673793B2 - Pallet exchange device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pallet exchanging device for exchanging pallets between a pallet pool and a machine table at the same time.

<Prior Art> A pallet exchanging device for exchanging pallets between a pallet pool that stores a plurality of pallets so that they can be indexed along a loop path and a machine table is known. First returns used pallets from the machine table to the pallet pool exchange position, then indexes the pallet to be used next to the exchange position, and then loads this pallet from the pallet pool to the machine table. Therefore, it takes a considerable time to replace the pallet, and the replacement time becomes even longer particularly in a random calling pallet pool.

In order to deal with such a problem, the applicant of the present application filed a pallet changing device for shortening the pallet changing time (Japanese Patent Application No. 59-199758). According to the prior application, arc-shaped support rails that slidably support the pallets are provided on a pallet support table of a pallet pool, and the pallets are indexed to a replacement position so that the pallet supports the machine table. Is used to form a circular orbit for pallet transportation, and two pallets are simultaneously exchanged between the pallet pool and the machine table along the circular orbit.

<Problems to be Solved by the Invention> However, in the above-mentioned prior application, it is necessary to provide pallet support bases and arc-shaped support rails as many as the number of pallets stored in the pallet pool. However, there is a problem that it becomes complicated and costly.

<Means for Solving Problems> The present invention has been made in view of the above-described conventional problems, and its gist is to enable a plurality of pallets to be indexed along a loop path in front of a machine table. A pallet pool for storing is installed, and an indexing device for sequentially indexing the pallets stored in the pallet pool to the exchange position is provided, and the pallet is arranged along a circular path between the exchange position of the pallet pool and the machine table. When a pallet is exchanged between the machine table and the exchange position, an arc-shaped support rail for slidably supporting the pallet is pivotably provided at the exchange position, and the pallet is exchanged between the machine table and the exchange position. At an angular position that forms a circular orbit centered on the exchange unit, and when indexing the pallets in the pallet pool, the pallet pool It is provided with a turning drive means for turning and driving to an angular position that constitutes the loop trajectory of the above.

<Operation> With the above configuration, when the pallet is replaced, the support rail at the replacement position is positioned at an angular position that forms a circular track with the machine table, and the pallet is moved along the circular track between the replacement position and the machine table. It is simultaneously replaced by the replacement unit. After that, the support rail is rotated 180 °, forming a loop track with the guide rail of the pallet pool, and the pallet on the support rail is carried out to the guide rail by indexing the pallet pool, and the pallet to be used next is It is carried on the support rail and circulated in the pallet pool. The support rail is then swiveled 180 ° again to replace the pallet.

<Examples> Examples of the present invention will be described below with reference to the drawings. FIG. 1 shows the whole of the pallet changing device, where 10 is a machine table of a machining center, 11 is a pallet pool, and 12 is a changing unit.

The machine table 10 includes a slide table 21 mounted horizontally on a bed 20 (FIG. 2) in the direction of an arrow and an index table 22 mounted on the slide table 21 so as to be rotatable and indexable. Become this indexing table
An arc-shaped clamp rail 23 is supported by 22 so as to be able to move up and down. A pallet 24 is slidably engaged with and supported by the clamp rail 23, and the pallet 24 is positioned and clamped on the indexing table 22 by lowering the clamp rail 23, and is unclamped by ascending. On the slide table 21, arcuate guide rails 25 that are aligned with both sides of the clamp rail 23 are installed. Thus, the slide table 21 is positioned at a fixed position corresponding to the pallet exchange position of the pallet pool 11 described later when the pallet is exchanged.

As shown in FIG. 2, a support frame 27 is fixedly installed on the front side of the bed 20, and a support shaft 28 installed on the support frame 27 has a swivel axis 29 which is perpendicular to the center of curvature of the clamp rail 23. It is rotatably supported around. A swivel arm 30 is fixedly mounted on the swivel shaft 29, and engagement blocks 31 attached to the side surfaces of the pallet 24 on both sides of the swivel arm 30.
Engaging hooks 30a and 30b that are releasably engaged with are formed. A pinion 15 is formed on a swivel shaft 29, and a rack piston 16 meshing with the pinion 15 is slidably mounted on a swivel cylinder 17 formed on a support base 28, and the rack piston 16 slides to swivel. It is designed to rotate the arm 30 180 °. The swivel shaft 29, swivel arm 30, swivel cylinder 17 and the like constitute the exchanging unit 12 for exchanging the pallet 24 between the machine table 10 and the pallet pool 11.

An arc-shaped guide rail 32 for slidably guiding the pallet 24 is disposed on the support frame 27 concentrically with the swivel shaft 29. These guide rails 32 form a circular track 33 for pallet exchange by the clamp rail 23 and a support rail described later.

The pallet pool 11 is installed in front of the machine table 10 with the revolving arm 30 in between, and stores a plurality of pallets 24 that can be indexed along a horizontal loop path.
That is, the machine base 35 of the pallet pool 11 is provided with guide rails composed of an inner rail 36 and an outer rail 37 that are spaced apart from each other in a loop shape, and these inner and outer rails 3
Support rollers 38,3 that support the bottom surfaces on both sides of the pallet 24 on the 6,37
A large number of guide rollers 40, 41 for guiding both side surfaces of the pallet 24 and the pallet 24 are supported at appropriate intervals.

Inside the inner rail 36, a drive sprocket 43 and a driven sprocket 44 are rotatably supported around a vertical axis with a space in the longitudinal direction of the loop, and an endless chain 45 is provided between these two sprockets 43, 44. Have been passed over. As shown in FIGS. 4 and 5, the chain link 46 of the chain 45 is formed with sandwiching engagement pieces 47 at a constant pitch interval. The sandwiching engagement pieces 47 are formed on the side surfaces of the pallet 24. The fitting convex portion 48 is adapted to be detachably engaged. The drive sprocket 43 is adapted to be intermittently rotated at a constant rotation angle by an indexing drive motor 51 installed in a gear box 50 provided on the machine base 35, whereby the pallet 24 and the chain 45 are inwardly driven. Further, it is conveyed along an elliptical loop track 52 composed of the outer rails 36 and 37 and a support rail described later, and is sequentially indexed to the pallet exchange position CP. In addition, 49 in FIG. 4 shows a chain guide plate.

At the pallet exchange position CP, as shown in FIGS. 2 and 3, an arc-shaped support rail 55 which slidably engages and supports the pallet 24 is installed so as to be vertically movable and rotatable. That is, a rotary shaft 57 is rotatably supported on a support base 56 fixed to the support frame 27 about a vertical axis, and a support base 58 is integrally attached to the upper end of the rotary shaft 57. A pair of lift cylinders 59 are formed on the support base 58 with the axis of the rotary shaft 57 interposed therebetween, and a piston rod 60 is fitted in these cylinders 59 so as to be slidable in the vertical direction.
One end of each piston rod 60 is projected above the support base 58, and the support rail 55 is fixed to the one end thereof. A pinion 61 is formed on the rotating shaft 57, and a rack shaft 62 is meshed with the pinion 61. The rack shaft 62 is connected to a turning cylinder (not shown), and the turning shaft rotates the rotating shaft 57 by 180 ° so that the center of the circular arc of the support rail 55 becomes the first angular position corresponding to the machine table 10 side. The pallet pool 11 can be positioned at a second angular position corresponding to the side. In addition, reference numeral 65 in FIG. 2 denotes a positioning pin provided on the support base 58 so as to be able to move up and down, and the positioning pin 65 is used when the support rail 55 is rotated.
To restrain the movement of the pallet 24.

In the above-described configuration, when the pallet 24 is in the standby state for replacement, the support rail 55 at the replacement position CP is positioned at the first angular position that is an arc centered on the turning axis. The engagement block 31 of the pallet 24 to be engaged is in a state of being engaged with one engagement hook 30a of the turning arm 30.

When the machining of the workpiece on the machine table 10 is completed in the appropriate state, the slide table 21 is positioned at a fixed position for pallet exchange, and then the clamp rail is mounted.
The pallet 24 is unclamped by raising 23, and the engaging block 31 is engaged with the other engaging hook 30b of the revolving arm 30. As the clamp rail 23 rises, the clamp rail 23, the guide rails 25 and 32, and the support rail 55 form a circular track 33 having the same height around the pivot arm 30.

Subsequently, the swivel arm 30 is swung, and the pallet 24 on which the machined workpiece on the clamp rail 23 is placed and the pallet 24 on which the unmachined workpiece is placed on the support rail 55 are placed on the circular path 33. Both pallets 24 are transferred at the same time between the machine table 10 and the replacement position CP of the pallet pool 11. Next, the clamp rail 23 is lowered to position and clamp the pallet 24 on the machine table 10, and the engagement block 31 thereof is disengaged from the engagement hook 30a of the revolving arm 30. In that state, the slide table 21 is processed. Be moved to.

Thereafter, the lifting cylinder 59 is operated to raise the support rail 55 by a certain amount, and the engagement block 31 of the pallet 24 is disengaged from the engagement hook 30b of the turning arm 30. In that state, a supporting rail together with the rotating shaft 57 is provided by a turning cylinder (not shown).
55 is turned 180 degrees, and then the lifting rail 59 is actuated to lower the support rail 55 by a certain amount so that the engaging protrusion 48 of the pallet 24 on the support rail 55 causes the engaging piece 47 of the endless chain 45 of the pallet pool 11. Is engaged with. This will support rails
55 and the inner and outer guide rails 36 and 37 form a loop track 52 having the same height.

Subsequently, the drive motor 51 is activated to index the endless chain 45, and the pallet 24 is transferred along the loop track 52.
Then, when the pallet 24 to be used next is indexed to the exchange position CP, the lifting cylinder 59 raises the support rail 55 by a predetermined amount, and the engaging projection 48 of the pallet 24 on the support rail 55 causes the endless chain. It is disengaged from the engagement piece 47 of 45. After that, the support rail 55 is rotated 180
It is turned by 90 degrees and is again positioned at an angular position that forms an arc around the turning arm 30, and then lowered by a predetermined amount by the lifting cylinder 59. As a result, the engagement block 31 of the pallet 24 is engaged with the engagement hook 30b of the revolving arm 30, and in this state, the pallet 24 stands by until the next pallet replacement.

In the above-described embodiment, the support rail in the exchange position is made swingable and can be raised and lowered, and this lifting movement disengages the engagement block of the pallet from the engagement hook of the swing arm, and the engagement protrusion of the pallet and the endless chain. Although the example of engaging and disengaging with the engaging piece has been described, the support rail may simply rotate when the swing arm and the means for engaging and disengaging on the endless chain side are provided.

In the above embodiment, the pallets stored in the pallet pool can be indexed along the elliptical loop orbit, but the pallet pool may be a circular orbit, and the circular orbit in this case is a circular orbit for pallet exchange. Is almost the same as the curvature of.

<Effects of the Invention> As described above, the present invention has a configuration in which pallets are simultaneously replaced between the machine table and the replacement position of the pallet pool, so that the pallet replacement time can be shortened.

In addition, the present invention is provided with a circular arc-shaped support rail rotatably at the pallet exchange position so that the pallet transport circular orbit during pallet exchange and the pallet transport loop orbit during pallet indexing of the pallet pool are commonly supported. Since the pallet pool can be formed by rails, the pallet pool may be a guide rail mechanism having a simple structure that can slidably support the pallet, which has the effect of simplifying the structure of the pallet pool.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a plan view showing the entire pallet changing device, and FIG. 2 is II-II of FIG.
3 is a sectional view taken along the line III-III in FIG. 2, FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1, and FIG. 5 is a line V in FIG. It is a perspective view. 10 …… Machine table, 11 …… Pallet pool, 12 ……
Exchange unit, 30 …… Swivel arm, 33 …… Circular orbit, 45…
… Endless chain, 51 …… Indexing drive motor, 52 …… Loop track, 55 …… Support rail, CP …… Replacement position.

Claims (2)

[Claims] 1. A pallet pool for storing a plurality of pallets which can be indexed along a loop path in front of a machine table, and an indexing device for sequentially indexing the pallets stored in the pallet pool to a replacement position. Is provided between the replacement position of the pallet pool and the machine table,
An exchange unit for simultaneously exchanging the pallet along a circular path is provided, and an arcuate support rail for slidably supporting the pallet is pivotably provided at the exchange position, and the support rail is provided between the machine table and the exchange position. When the pallet is to be exchanged with a rotary drive, it is rotated to an angular position that forms a circular orbit centered on the exchange unit, and to index a pallet in the pallet pool, to a angular position that forms a loop orbit of the pallet pool. A pallet exchanging device comprising a swiveling drive means for rotating. 2. The pallet exchanging device according to claim 1, wherein the support rail is movable up and down to engage and disengage the exchanging unit and the indexing device.