JPH0131414Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a work pallet changing device for machine tools such as machining centers.

<Prior art> Conventionally, in order to efficiently exchange work pallets on the table of a machine tool, the British patent no.
Publication No. 1223105 discloses that a rotating frame that is rotatable around a horizontal rotation axis is provided with four sets of pallet mounting parts extending radially in a water wheel shape with respect to the horizontal rotation axis, and each pallet mounting part has two pallet mounting parts. A set of connected work pallets can be mounted, and the work pallet can be transported back and forth in the axial direction of a rotating shaft between a pallet mounting part in a vertical position extending upward and a table in a vertical position of a machine tool, A work pallet changing device for a machine tool is described that makes it possible to remove chips by injecting an air jet onto the workpieces on the work pallets of the pallet mounting section in a horizontal position facing downward from the above-mentioned vertical position and the pallet mounting part in a vertical position extending downward. .

Further, the work pallet changing device for the machine tool is provided with a conveying device for conveying the work pallet between the changing device and the vertical table of the machine tool.

This conveyance device uses a roller mechanism that includes multiple guide rollers and multiple drive rollers to drive a single rod-shaped beam back and forth between an exchanger and a table of a machine tool. A mating member is provided, and the beam can be switched between three positions in the direction orthogonal to the table surface using a cylinder-type position switching mechanism, and by switching the beam position, the engaging part of the engaging member can be moved to the side of the work pallet. The work pallet can be reciprocated by driving the beam with a drive roller while the engaging portion is engaged with the side end of the work pallet.

On the other hand, Japanese Utility Model Publication No. 59-173536 discloses a machine tool in which a work pallet changing device similar to that in the British publication is provided on the right side of a table in a horizontal position when viewed from the front.

<Problems to be Solved by the Invention> By the way, the work pallet changing device described in the above-mentioned British publication still has the following drawbacks.

(a) Since this is a work pallet changing device for a machine tool that has a table in a vertical position, various difficulties arise when trying to apply this changing device to a machine tool that has a table in a horizontal position, such as a normal machining center.

(b) Since the four sets of pallet mounting parts extend radially in the radial direction with respect to the rotation axis with a phase angle of 90 degrees, the rotation radius of the rotation frame becomes extremely large, making a replacement device unnecessary. It becomes large.

(c) At least one pallet mounting part can be held in an upward horizontal position, so it is not impossible to apply it to machine tools having a table in a horizontal position; The work pallet being conveyed interferes with the bearings, sprockets, etc. of the rotation drive device that rotates the rotation frame. In order to prevent this, it is necessary to take measures such as supporting the work pallet high relative to the pallet mounting section and moving the work pallet transport area away from the rotation axis.
Alternatively, the transport mechanism becomes complicated.

(d) The conveyance device in the above British publication includes a large number of rollers such as guide rollers and drive rollers, an actuator that drives the drive rollers, and a long and narrow beam.
Since it is composed of a guide mechanism and a cylinder for changing the position of the beam, the number of parts is large, the structure is complicated, and the manufacturing cost is very high. In particular, since the structure is such that the position of the entire beam is switched in order to engage and disengage the engagement member and the workpiece pallet, the mechanism for switching becomes complicated. In addition, since the beam is driven by holding the beam between the drive rollers, if cutting oil or the like adheres to the drive rollers or the beam, they may become slippery and the beam cannot be driven reliably, or cutting chips may be deposited between the rollers and the beam. If it gets caught, it may become impossible to drive or the durability of the conveying device may decrease.

In addition, since the drive roller is installed between the work pallet changing device and the machine tool, it is necessary to leave a considerable amount of space between the work pallet changing device and the machine tool, which greatly limits the placement of the work pallet changing device. Become.

Therefore, it is conceivable to place the above drive roller on the side of the rotating frame of the work pallet changing device, but in this case the required length of the beam becomes large, making it difficult to transport the work pallet from the table of the machine tool to the rotating frame. However, since the beam protrudes significantly outside the work pallet exchange device, there are problems in that a large space is required for the conveyance device and it is not desirable in terms of safety in the working environment.

The work pallet changing device described in the above-mentioned Japanese Utility Model Publication No. 59-173536 has the same problems as (b) and (c) above, and the work pallet changing device is disposed on the right side of the table, Since the work pallets are conveyed in this direction, there are problems such as the conveyance device for conveying the work pallets having a long stroke and becoming large in size. When a conveyance device is attached to the work pallet exchange device, a conveyance device must be provided at each pallet mounting portion of the rotary frame, which increases the number of conveyance devices required. Therefore, it is conceivable to provide a conveying device independently near the rotating frame, but in this case, when rotating the work pallet with the rotating frame, the engagement between the output section of the conveying device and the conveying engagement section on the work pallet side is released. There are problems such as the need to provide the release means near the rotating frame and the need to perform a release operation on the release means each time the rotating frame is rotated.

<Means for Solving the Problems> A work pallet changing device for a machine tool according to the present invention is provided with a pallet fixing device on a table in a horizontal position of a machine tool, and a work pallet can be mounted and fixed on this pallet fixing device, and the above-mentioned work pallet changing device is provided. A pallet exchange device is arranged on the front side of the machine tool, a plurality of pallet support surfaces are provided on the pallet exchange device, and each pallet support surface is set at a pallet exchange position on the front side of the pallet fixing device and a pallet retraction position shifted from the pallet exchange position. In the work pallet changing device for a machine tool, the work pallet can be transferred between the pallet supporting surface at the pallet changing position and the pallet fixing device by means of a conveying device, and the work pallet can be transferred. The pallet support frame is composed of a rectangular and flat plate-shaped pallet support frame that is elongated in the left-right direction with respect to the machine tool when viewed, a machine frame that supports the pallet support frame, a rotation drive device, and a holding means. The pallet support frame is pivotally supported on the machine frame so as to be rotatable around a horizontal pivot axis in the left and right direction passing through the approximate center of the pallet support frame, and is rotatably driven around the pivot axis by a rotation drive device, Pallet supporting surfaces are provided at two locations on both sides of the pallet supporting frame, and among the pallet supporting surfaces, the upward facing pallet supporting surface is located at the pallet exchange position, and the downward facing pallet supporting surface is located at the pallet retracting position. The conveying device includes an actuator attached to the machine frame near the left side or near the right side of the pallet support frame, and a pallet exchange device and the pallet by this actuator. an output member that is reciprocally driven by extending and retracting in the front-rear direction over the fixing device; a conveying engagement portion that is provided on the left end or right end of the work pallet so as to be freely retractable and is elastically biased toward the projecting side; An output part attached to the tip of the output member, which is vertically oriented, has both upper and lower ends released, and has an engagement recess that removably engages with the conveyance engagement part, and is formed on both front and rear sides of the engagement recess. The apparatus is equipped with an output section consisting of a guiding inclined section, and a release means attached to the table or the pallet fixing device for disengaging the engagement between the conveying engagement section and the engagement recess.

<Function> In the work pallet changing device according to the present invention, A. A pallet fixing device is provided on the table of the machine tool in a horizontal position, the pallet changing device is arranged on the front side of the machine tool, and the pallet support frame of the pallet changing device is placed in a flat state. The work pallet is formed into a flat plate with a rectangular shape elongated from side to side when viewed from side to side, and the work pallet is conveyed back and forth between the pallet fixing device and the pallet changing device. It can be simplified.

B The pallet support frame of the pallet exchange device is a flat plate with a rectangular shape elongated in the left and right direction when viewed from above, and is rotated around a horizontal pivot axis in the left and right direction that passes through its approximate center. By making the rotating radius of the frame extremely small, the pallet exchange device can be made as compact as possible, and the pallet exchange device can be installed using a space equivalent to approximately one surface of the work pallet on the front side of the machine tool. Therefore, this exchange device can be applied to existing machine tools relatively easily.

C. The work pallet is transported in the front-rear direction between the pallet exchange device and the pallet fixing device, and the pallet support frame of the pallet exchange device is rotated around a horizontal axis in the left-right direction by a rotation drive device.
Since there is no interference between the bearings and sprockets of the rotary drive device and the work pallet when transporting the work pallet, it is possible to reduce the thickness of the pallet support frame and the support height of the work pallet relative to the pallet support frame. This makes it possible to reduce the radius of rotation between the pallet support frame and the work pallet, thereby making it possible to downsize the pallet exchange device, and to increase the degree of freedom in designing the rotary drive device.

D The pallet support frame has a flat plate shape and is designed to be rotated around a rotation axis that passes through the center of the frame.Since pallet support surfaces are provided on both sides of the frame, the weight of the work pallets on both pallet support surfaces can be distributed. Even when different workpieces are attached, the moment of inertia does not increase so much and the rotary drive device can be made smaller because the rotary drive device can be rotated with a relatively small rotational torque.

E. Since the actuator of the conveyance device is placed near the left or right side of the pallet support frame, there is no need to provide an actuator between the table of the machine tool and the pallet exchange device, making it possible to connect the pallet exchange device to the machine tool. Can be placed close to.
This also reduces the size of the transport device.

In addition, since the output member of the conveyance device is reciprocated by extending and retracting in the front and rear directions by the actuator, it does not protrude to the side opposite to the table with respect to the pallet exchange device, and the output member of the conveyance device Requires less space.

In addition, the conveyance engagement section is retractable and elastically biased toward the protruding side, and guiding slopes are formed on both front and rear sides of the engagement recess of the output section, so that the workpiece pallet on the pallet fixing device is Then, when the output member is extended, the engaging recess automatically engages with the conveying engaging part due to the guiding action of the guiding inclined part.

Alternatively, when a work pallet is transferred from the outside onto the pallet support frame, the engaging recess automatically engages with the conveyance engaging part in the same manner as described above.

Furthermore, since the upper and lower ends of the engagement recess are open, when rotating the workpiece pallet together with the pallet support frame, the workpiece pallet can be rotated without having to specifically release the engagement between the engagement recess and the conveyance engagement section. and will automatically engage after rotation has stopped.

In addition, since the conveyance device is independently provided near the pallet support frame, the number of conveyance devices can be reduced and the structure can be simplified compared to the case where the conveyance device is provided on the pallet support frame.

<Effects of the invention> According to the workpiece pallet changing device for a machine tool according to the present invention, as explained in detail in the section of “Function” above, the pallet transport distance between the table and the pallet changing device can be made as small as possible. The conveyance device can be made smaller and simpler, the pallet support frame can be made smaller and the pallet exchange device can be made smaller, it can be easily applied to existing machine tools, the rotary drive device can be made smaller, and the pallet Not subject to restrictions on the placement of replacement equipment;
The space required for the transport device is reduced;
The structure of the conveying device is simplified by using the release means to release the engagement between the conveying engagement portion and the output portion, and the structure of the conveying device is simplified by providing the conveying device independently of the pallet support frame. The structure can be simplified by reducing the number of pallets, the work pallets on the pallet fixing device can be carried out efficiently without using release means, and the engagement recess and the conveying engagement can be used when rotating the work pallet together with the pallet support frame. Effects such as being able to automatically release and engage without having to perform a release or engagement operation with the part, that is, the release means only need to be provided on the table or pallet fixing device. .

<Example> Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 (See FIGS. 1 to 7) A pallet exchange device 2 is installed on the front side of a machine tool 1 such as a machining center. The pallet exchange device 2 has a flat plate-shaped pallet support frame 4 on the top of a box-shaped machine frame 3 with an open top, which can be rotated around a horizontal axis 6 in the left-right direction by a rotary drive device 5, and a rotary lock cylinder. 7, it is configured to be supported in a rotationally lockable manner. The rotational drive device 5 is arranged at the upper left of the machine frame 3, and controls the rotation of the electric motor 8 by a worm reducer 9.
and the gear reduction mechanism 10, the pallet support frame 4
The structure is such that it rotates.

A pallet support surface 11 and a holding means 12 are provided at two locations separated by 180 degrees in the rotational direction of the pallet support frame 4. The holding means 12 includes headed pins 13a, 13 protruding from four locations on the front, rear, left and right sides of the pallet support surface 11.
b, and a holding cylinder 14 that moves upward and back. A pair of left and right rails 15 are laid on the pallet support surface 11.

On the fixed platen 17 on the table 16 of the machine tool 1, a rail 18, a stopper 19, and a pair of coupling cylinders 20 are provided on the left and right, and the pallet receiver 2
1 and six clamp cylinders 22 are provided in each of the front, rear, left and right sides.

A rail groove 2 is provided on the bottom surface of the work pallet 23.
4. A T-groove 25, a stopper/suspension hole 26, and a plug hole 27 are formed in pairs on the left and right, one holding hole 28 is formed, and a large number of work clamps 23a are formed on the upper surface of the work pallet 23 over the entire surface thereof. is provided. Each wheel running device 29 is installed inside each rail groove 24, and the wheel running device includes a large number of wheels 3.
A strip member 31 with a U-shaped cross section, which is pivotally supported in front and back rows, is pressed downward by a spring 32, and a pin 33 fixed to the strip member 31 is received by a fall prevention device 34 fixed to the upper surface of the rail groove 24. Ru. The wheels 30 ride on the rails 15 and 18, and the rail grooves 24 fit into the rails 15 and 18 to guide travel.

The machined work pallet 23 on the table 16 of the machine tool 1 is transferred to the clamp cylinder 22.
It is released from the holder and floated by the spring 32, and then transferred to the transport device 35.
The pallet is carried out onto the upward facing pallet support surface 11, and the stopper/hanging hole 26 is received and fitted to the headed pin 13a, and the T groove 25 is fitted to the headed pin 13b, and the holding cylinder 14 is held. By inserting it into the hole 28, it is held by the holding means 12.

By unlocking the rotary lock device 7, rotating the pallet support frame 4 with the rotary drive device 5, and locking the rotation with the rotary lock device 7, the workpiece pallet 23 that has been machined is turned downward and the chips are dropped. At the same time, a cleaning liquid is sprayed from the cleaning nozzle 36 at the lower part of the machine frame 3 to further wash away the chips, and the unprocessed workpiece pallet 2 on the upward facing pallet support surface 11 is cleaned.
3 is released by disengaging the holding cylinder 14 and the holding hole 28, is carried onto the table by the conveying device 35, is received by the stopper 19, and the fitting cylinder 20 and the fitting hole 27 are fitted. The pallet receiver 21 is positioned by the clamp cylinder 22 and is clamped onto the pallet receiver 21.

The conveying device 35 is arranged outside the left side of the pallet support frame 4, and the output section 37 of the conveying device 35 is connected to the pallet 2.
It is removably engaged with the conveying engagement pin 38 on the side portion of No. 3.

The conveyance device 35 is configured as shown in FIGS. 1 to 3. That is, two air cylinders 39,
40 are arranged in the left and right directions with the front and back reversed, and the cylinder bodies are fixed to each other with a pair of front and rear connecting fittings 41. The front end of a piston rod 42 protruding forward from the left air cylinder 39 is fixed to a folded-up front end portion 44 of a sliding guide rail 43 fixed to the machine frame 3. The output fitting 37 is fixed to the rear end of the piston rod 45 which projects to the rear of the right air cylinder 40 so as to project to the right. Rod 4 that prevents the output fitting 37 from swinging around the piston rod 45
6 penetrates through the guide hole 47 of the connecting fitting 41 so as to be slidable back and forth.

The output part metal fitting 37 has an engagement groove 48 recessed in the center of the right side surface in the front-rear direction, and an inclined cam surface 49 is formed on the front and rear sides of the engagement groove 48 . The conveying engagement pin 38 is supported in a fixed cylinder 50 on the left side of the work pallet 23 so as to be able to slide in and out to the left, and is pushed out to the left by a spring 51.

An engagement release cylinder 52 is attached to the left rear part of the fixed platen 17 on the table 16.
When activated, the conveying engagement pin 38 is pushed to the right to release the engagement with the output fitting 37.

Embodiment 2 (See FIGS. 8 to 11) This embodiment 2 has the structure of the above embodiment 1,
The conveying device 35 is changed from an air cylinder type to a steel belt type.

This steel belt type conveyor is powered by an electric/hydraulic or pneumatic motor 53 that rotates in forward and reverse directions.
By rotating the pair of friction wheels 56 via the reducer 54 and the torque limiter 55, the case 57
A steel belt 58 with an inner curl is moved forward and backward within guide rails 59 and 60, and an output fitting 37 fixed to the tip of the belt is driven back and forth.

Motor 53, reducer 54, torque limiter 5
5. The friction wheel 56 and the belt clamping force applying spring 61 are supported by a case 57, the case 57 is fixed to the upper left front part of the box-shaped machine frame 3 of the pallet exchange device 2, and the front guide rail 59 is attached to the box-shaped machine frame 3, and the rear guide rail 60 is fixed to the upper left front part of the fixed platen 17 on the table 16.

[Brief explanation of the drawing]

1 to 7 show Example 1 of the present invention,
Figure 1 is an enlarged plan view of the main part of Figure 4;
The figure is a side view of the part seen in the direction of the arrow in Figure 1, Figure 3 is a cross-sectional view taken along the line of Figure 1, Figure 4 is a schematic plan view of the whole, and Figure 5 is a schematic plan view of the whole.
The figure is a schematic right side view of the whole, FIG. 6 is a perspective view of the section shown in FIG. 4, and FIG. 7 is a longitudinal sectional side view of the section shown by the arrow in FIG. 8 to 11 show a second embodiment of the present invention, FIG. 8 is a schematic plan view of the whole, and FIG.
10 is a sectional view taken along the line of FIG. 9, and FIG. 11 is a sectional view taken along the line of FIG. 8. 1... Machine tool, 2... Pallet exchange device, 3
... Machine frame, 4 ... Pallet support frame, 5 ... Rotation drive device, 6 ... Horizontal axis, 7 ... Rotation lock device, 11 ... Pallet support surface, 12 ... Holding means, 16 ... Table , 23...work pallet, 35...conveying device, 37...output section of 35,
38...Conveyance engagement part.

Claims (1)

[Scope of Claim for Utility Model Registration] A pallet fixing device is provided on a table in a horizontal position of a machine tool, a work pallet is mounted on this pallet fixing device so that it can be fixed, a pallet changing device is arranged on the front side of the machine tool, and the pallet is The exchange device is provided with a plurality of pallet support surfaces, and each pallet support surface can be switched between a pallet exchange position on the front side of the pallet fixing device and a pallet retraction position shifted from the pallet exchange position. In a work pallet changing device for a machine tool, the work pallet is configured to be able to be transferred and reloaded between the pallet fixing device and the pallet fixing device by means of a conveying device. The pallet support frame is made up of a flat plate-shaped pallet support frame, a machine frame that supports the pallet support frame, a rotation drive device, and a holding means, and the pallet support frame is connected to the machine frame through approximately the center of the pallet support frame. The pallet is pivoted so as to be rotatable around a horizontal pivot axis in the left and right direction, and is rotatably driven around the pivot axis using a rotation drive device, so that the pallet can be mounted at two locations on both sides of the pallet support frame. Support surfaces are provided, and among the pallet support surfaces, the upward pallet support surface is located at the pallet exchange position, and the downward pallet support surface is located at the pallet retraction position, so that each work pallet is held on each pallet support surface. The conveying device includes an actuator attached to the machine frame near the left side or right side of the pallet support frame, and this actuator extends and extends in the front and back direction between the pallet exchange device and the pallet fixing device.
an output member that is reciprocally driven when retracting and reciprocating; a conveying engagement portion that is provided on the left or right end of the work pallet so as to be horizontally retractable in the left-right direction and is elastically biased toward the protruding side; and a distal end of the output member. An engagement recess which is an output part attached to the part and whose upper and lower ends are opened vertically and removably engages with the conveyance engagement part, and a guiding slope formed on both front and rear sides of the engagement recess. A workpiece pallet changing device for a machine tool, characterized in that it is equipped with an output section comprising: and a release means attached to the table or pallet fixing device for releasing the engagement between the conveying engagement section and the engagement recess. .