Pallet exchange device

Abstract

To provide a pallet exchange device which makes an operator easily approach an opening of a machine tool.SOLUTION: A pallet exchange device 1 includes pallet conveyance means 3 which is adjacent to a machine tool M, is provided so as to be movable between a pallet exchange position C facing an opening A of the machine tool and a standby position H separated from the pallet exchange position, and gives / receives a pallet P to / from a working table W of the machine tool M, wherein the pallet conveyance means 3 includes a straight motion guide mechanism 4 which is movable in a direction crossing the pallet exchange position C, on the side of the machine tool M.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a pallet exchange device, and more particularly to a pallet exchange device that can secure a space in front of an opening of a machine tool that allows easy entry for an operator. [Background technology]

[0002] Machine tools that perform metal processing such as turning, milling, and drilling are often used in conjunction with a pallet exchange device (also called a pallet changer) for exchanging pallets carrying objects to be processed (workpieces). The pallet exchange device is generally placed adjacent to the machine tool and operates in conjunction with the machine tool by sending and receiving signals for exchanging pallets between the machine tool and the machine tool's control device, thereby improving the operating rate and productivity of the machine tool.

[0003] There are various types of pallet changers, such as inverted, tilted, clamped, and shuttle types, and they can be used according to the purpose. For example, shuttle-type pallet changers can move the pallet linearly and can change the pallet without moving the table on the machine tool side, so they can be applied to a wide range of machine tools, such as vertical machining centers and large gate-type machine tools.

[0004] As a shuttle-type pallet exchange device, for example, Patent Document 1 describes a pallet exchange device that includes a carriage that reciprocates at a constant stroke between first and second setup stations set on both the left and right sides of a carry-in / out station, first and second pallet transfer devices mounted on the carriage, and a pallet carry-in / out device that transports a pallet placed on the first or second pallet transfer device between the carry-in / out station and the processing station. This pallet exchange device is characterized in that the pallet carry-in / out device has a hook member that engages with the pallet and moves forward and backward, and this hook member has three stop positions: a retreated position on the pallet carry-in / out device, an advanced position facing the processing station, and a retreated standby position just before the processing station.

[0005] Also, Patent Document 2 describes a shuttle-type pallet exchange system that has a plurality of pallet transport tables that are movable in a direction crossing the pallet exchange position in front of the machine tool, and transfers pallets between the pallet transport table at the pallet exchange position and the machining table. In this pallet exchange system, a drive mechanism with a drive gear is provided at the pallet exchange position, and each pallet transport table is provided with a driven gear, a pallet moving mechanism connected to the driven gear, and a pallet support mechanism mounted on the driven gear, and when the pallet transport table reaches the pallet exchange position, the driven gear is set to mesh with and engage with the drive gear of the drive mechanism. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2010-131718 A [Patent Document 2] Japanese Patent Application Publication No. 6-126582 Summary of the Invention [Problem to be solved by the invention]

[0007] In the case of the pallet exchange device described in Patent Document 1, a bed of approximately the same width as the carriage is disposed in front of the processing station, a pallet transfer device is disposed on the bed, and a pallet loading / unloading device is disposed on the opposite side of the bed. In the case of the pallet exchange device described in Patent Document 2, a guide rail is disposed in front of the processing table of the machine tool, a pallet transport table is disposed on this rail, and a drive mechanism is disposed on the opposite side of the rail (pallet exchange position). Thus, with the conventional shuttle-type pallet exchange device, it is considered difficult for an operator to approach the machine tool, and it is difficult to approach the workpiece inside the machine tool to visually check the processing status or directly touch it.

[0008] The present invention has been made in consideration of the above circumstances, and has an object to provide a pallet exchange device that allows an operator to easily approach a machine tool. [Means for solving the problem]

[0009] The pallet exchange device of the present invention is a pallet exchange device that is adjacent to a machine tool and is movable between a pallet exchange position facing an opening of the machine tool and a waiting position away from the pallet exchange position, and is equipped with a pallet transport means for transferring pallets between the work table of the machine tool, and is characterized in that the pallet transport means is provided with a linear guide mechanism on the side of the machine tool that enables movement in a direction crossing the pallet exchange position.

[0010] The pallet transport means has a pallet movement mechanism that enables the pallet to be transferred linearly between the processing table, and the pallet movement mechanism has a slide means that extends in three stages toward the processing table.

[0011] The pallet transport means has a drive source for moving in a direction crossing the pallet exchange position, and a drive source for the pallet movement mechanism.

[0012] The pallet transport means has at least one servo motor as the drive source.

[0013] The opening is adjacent to a machine tool having a window for introducing a pallet. Effect of the Invention

[0014] In the pallet exchange device of the present invention, the pallet transport means is provided on the machine tool side with a linear guide mechanism that enables movement in a direction crossing the pallet exchange position, so that the rails of the linear guide mechanism are less likely to hinder the operator's approach to the pallet exchange position, making it easier for the operator to approach the machine tool.

[0015] The pallet transporting means has a pallet moving mechanism that enables the pallet to be transferred in a linear manner to and from the processing table, and the pallet moving mechanism has a slide means that extends in three stages toward the processing table, making it easier to make the pallet transporting means smaller and ensuring more space for the worker to approach the opening.

[0016] Since the pallet transporting means has a drive source for moving in a direction crossing the pallet exchange position and a drive source for the pallet moving mechanism, there is no need to place a device for transporting the pallet into and out of the work table in a position opposite the machine tool, making it easier for the worker to get close to the machine tool.

[0017] Since the pallet transport means has at least one servo motor as a drive source, the pallet exchange device can operate accurately and quickly, resulting in excellent operability.

[0018] Since the pallet exchange device is adjacent to a machine tool having a window for introducing a pallet as an opening, it is particularly suitable for relatively small machine tools where an operator cannot enter the inside of the machine and has difficulty in approaching the workpiece. [Brief description of the drawings]

[0019] [Figure 1] 1 is a schematic plan view showing an example of a pallet exchange device of the present invention. FIG. [Diagram 2] FIG. [Diagram 3] 3 is an enlarged view of the linear motion guide mechanism and its periphery in FIG. 2. [Figure 4] FIG. 4 is a diagram showing the internal structure of a pallet moving mechanism. [Diagram 5] FIG. 5 is an enlarged view of the sliding means in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] An example of a pallet exchange device of the present invention will be described with reference to Fig. 1. Fig. 1 is a schematic plan view of a pallet exchange device. As shown in Fig. 1, the pallet exchange device 1 is disposed, for example, adjacent to a machine tool M so as to face an opening A of the machine tool M. The pallet exchange device 1 includes a housing 2 and a pallet transport means 3 for transferring a pallet P between the housing 2 and a work table W of the machine tool M. The width (length in the X-axis direction) of the housing 2 is, for example, 150 to 350 cm. The width of the pallet transport means 3 is, for example, 40 to 100 cm.

[0021] In FIG. 1, the pallet transport means 3 is provided inside the housing 2 so as to be able to slide and move in a direction (X-axis direction) across the pallet exchange position C facing the opening A, and can move between the pallet exchange position C and a standby position H away from the pallet exchange position C. The pallet exchange device 1 has two pallet transport means 3, 3. The pallet exchange device 1 has a function of securing a space for an operator Op to approach the opening A. Therefore, compared to the conventional pallet exchange device, the operator Op can easily approach the pallet exchange position C during processing with the machine tool M, and can easily grasp the processing status. The operator Op is not limited to a human being, and may be a robot. The pallet transport means 3 is preferably a shuttle-type pallet transport means that linearly transfers the pallet P between the processing table W and the pallet transport means 3. The pallet transport means 3 is not limited to the shuttle type, and may be a turn type that moves the pallet P by rotation.

[0022] The pallet exchange device 1 may have one or more pallet transport means 3. From the viewpoints of work efficiency and space conservation, it is preferable that the pallet exchange device 1 has two pallet transport means 3.

[0023] Examples of the function of the pallet exchange device 1 to ensure space for the worker Op to approach the opening A include the following. The pallet exchange device 1 can have a function of the pallet transport means 3 waiting at the standby position H when the worker Op approaches the opening A. The pallet transport means 3 may have a function of waiting at the standby position H except when the pallet P is transferred between the processing table W and the pallet at the pallet exchange position C, and ensuring space for the worker Op to approach the opening A. The pallet transport means 3 may have a function of waiting at the pallet exchange position C even after the pallet P is transferred between the processing table W and the pallet, and moving to the standby position H and waiting only when the worker Op approaches the opening A. Furthermore, the pallet exchange device 1 can ensure space for the worker Op to approach the opening A by arranging members that are likely to hinder the worker Op's approach to the opening A on the side of the machine tool M.

[0024] In Fig. 1, the opening A of the machine tool M is a window for introducing a pallet P on which workpieces are placed. The pallet P is handed over between the pallet exchange device 1 and the machine tool M through this window. When the pallet exchange device 1 is a machine tool M having a window for introducing a pallet as the opening A, in order to grasp the status of the workpieces, the worker Op needs to get as close as possible to the window to see inside the machine tool M, compared to a relatively large machine tool that allows the worker Op to enter and exit the inside. For this reason, the pallet exchange device 1 of the present invention, which allows the worker Op to easily approach the pallet exchange position C, is suitable for use with a relatively small machine tool M having a window for introducing a pallet as the opening A.

[0025] The housing 2 has a frame 21a extending in the X-axis direction. The frame 21a is provided with a linear guide mechanism 4 along its long axis direction. The linear guide mechanism 4 supports the pallet transport means 3 so as to be movable in the X-axis direction. The housing 2 further has two frames 22, 22 extending in the Z-axis direction (up and down direction) at both ends in the X-axis direction on the machine tool M side, and has a step 23 at the bottom. The frame 21a is supported by the frames 22, 22. The linear guide mechanism 4 may be provided in a member constituting the housing 2 other than the frame 21a, or may be provided in a member not constituting the housing 2. The housing 2 may have more than two frames 22 extending in the Z-axis direction.

[0026] The pallet conveying means will be described with reference to Fig. 2. Fig. 2 is a side view of the pallet conveying means as viewed along the X-axis direction. Note that the frame, steps, rails of the linear guide mechanism, and the like extending in the X-axis direction are shown in cross section. In Fig. 2, the housing 2 has frames 21a and 21b extending in the X-axis direction, one above the other, and the frames 21a and 21b are connected by a frame 22. The step 23 is provided with an adjustment member 24 capable of adjusting the height from the floor surface F, and the step 23 is supported at a height of, for example, about 5 to 20 cm from the floor surface F. The frame 21a is supported at a height of, for example, about 40 to 80 cm from the floor surface F.

[0027] In the case of a conventional pallet exchange device, the coolant and chips generated by machining are collected in an oil pan provided around the platform on which the pallet is placed, and if the coolant overflows or splashes from the oil pan, there is a risk of contaminating the floor surface. In contrast, if the pallet exchange device has a step, it is possible to prevent the coolant from directly dropping onto the floor surface and contaminating it, and it is possible to improve the accessibility and workability to the workpiece. From the viewpoint of preventing floor surface contamination, it is preferable that the step is provided with a wall-shaped peripheral wall portion on the periphery so that the liquid is unlikely to flow out. In addition, it is preferable that the step is removable from the housing. In this case, the configuration of the device is simplified, and the workability when adjusting the device height with the adjustment member is excellent.

[0028] The pallet transport means 3 has a drive source 5a for moving the means in the X-axis direction, and a drive source 5b (for the pallet moving mechanism 9 described later) for moving the pallet P in the Y-axis direction. The drive sources 5a and 5b are, for example, motors that generate rotational force. The drive source 5a is provided on the back panel 31 on the machine tool side inside the pallet transport means 3 so that its rotation axis is perpendicular to the X-axis direction. The drive source 5b is provided above the pallet transport means 3 and below the pallet moving mechanism 9 so that its rotation axis is perpendicular to the Y-axis direction. The drive source 5b may be provided inside the pallet moving mechanism 9.

[0029] As the driving sources 5a and 5b, for example, a hydraulic pump, a hydraulic motor, a general motor, a stepping motor, a servo motor, etc. can be used. From the viewpoint of accurate position and speed control, the driving sources 5a and 5b are preferably servo motors. Furthermore, when the driving sources 5a and 5b are servo motors, they can be sensorless and hydraulicless, and the man-hours for daily maintenance can be reduced. The current for driving the driving sources 5a and 5b may be either AC or DC.

[0030] It is preferable that the pallet transport means 3 has at least one drive source 5a and one drive source 5b. In this case, the movement of the pallet P in the X-axis and Y-axis directions is performed only by the pallet transport means 3, so the number of devices constituting the pallet exchange device 1 can be reduced. For example, there is no need to separately place a device for moving the pallet P in the Y-axis direction at a position facing the machine tool, making it easier for the operator to approach the machine tool. The pallet transport means may have one drive source or two or more drive sources.

[0031] The upper frame 21a and the lower frame 21b are provided with linear guide mechanisms 4, 4 via connecting members 6, 6, respectively. The linear guide mechanisms 4, 4 are provided on the back plate 31 and are arranged between the pallet transport means 3 and the housing 2. That is, the pallet transport means 3 is provided with a linear guide mechanism 4 on the machine tool side that enables the pallet transport means 3 to move in a direction crossing the pallet exchange position. This makes it easier for the operator to approach the pallet exchange position when the pallet transport means 3 is waiting at the standby position. In addition, in FIG. 2, the pallet transport means 3 is connected to the housing 2 by two linear guide mechanisms 4, 4, but the number of linear guide mechanisms 4 to which the pallet transport means 3 is connected may be one or more.

[0032] The linear guide mechanism that enables the movement of the pallet transport means will be described with reference to Fig. 3. Fig. 3 is an enlarged view of the upper linear guide mechanism and its surroundings in the side view shown in Fig. 2.

[0033] The linear guide mechanism 4 has a long rail 41 extending in the X-axis direction and a block 42 that moves while sliding along the long axis direction of the rail 41. The rail 41 is provided on the upper frame 21a via a connecting member 6, and the block 42 is provided directly on the back plate 31. From the viewpoint of moving a plurality of pallet conveying means 3, the linear guide mechanism 4 preferably has a plurality of blocks 42 for one rail 41. From the viewpoint of stably moving even a heavy object, it is preferable that two or more blocks 42 are provided for one pallet conveying means 3. The rail 41 has a pair of track grooves G, G extending in the long axis direction. The block 42 has a pair of protrusions R, R that fit into the pair of track grooves G, G. The block 42 can move linearly along the rail 41 by fitting the protrusions R, R into the track grooves G, G. The linear guide mechanism 4 may be connected to the pallet conveying means 3 or the housing 2 directly or via a member such as a connecting member 6. The connection of each member may be reversibly fixed by fastening screws or bolts, or may be irreversibly fixed by welding, adhesive, etc. In addition, the rail 41 may be provided on the side of the back panel 31, and the block 42 may be provided on the side of the housing 2.

[0034] As the linear guide mechanism, for example, a ball-type linear guide such as a ball recirculating linear bearing or a sliding-type linear guide using a sliding material can be used. As the linear guide mechanism, a sliding-type linear guide is preferable from the viewpoint of load resistance, and a ball-type linear guide is preferable from the viewpoint of low friction.

[0035] The rotational force generated by the driving source 5a is transmitted to the pinion gear 7, which is a cylindrical gear, via the rotation shaft S. The pinion gear 7 is fixed to the frame 21a via the connecting member 6, and the teeth of the pinion gear 7 engage with those of a rack gear 8, which is a rod-shaped member having a plurality of teeth. When the driving source 5a rotates the pinion gear 7, the pinion gear 7 and the rack gear 8 mesh, and the pallet transport means 3 receives a repulsive force from the rack gear 8 via the pinion gear 7. As a result, the rotational force generated by the driving source 5a is converted into a linear force (linear motion) along the major axis direction of the rack gear 8, and the pallet transport means 3 moves in the X-axis direction.

[0036] Again, referring to Figure 2, the pallet movement mechanism, which is a mechanism for moving the pallet in the Y-axis direction, will be described. As shown in Figure 2, the pallet transport means 3 has a pallet movement mechanism 9 on its upper part, which transfers the pallet P to and from the processing table of the machine tool. This pallet movement mechanism 9 is a mechanism that converts the rotational force of the drive source 5b into a linear expansion and contraction movement, and enables the transfer of the pallet between the pallet transport means and the processing table to be performed linearly.

[0037] The details of the pallet moving mechanism will be described with reference to Figures 4 and 5. Figure 4 is a front view showing the internal structure of the pallet moving mechanism, specifically, a view of the inside of the pallet moving mechanism as seen along the Y-axis direction towards the machine tool (the rear side of the page is the machine tool side). The pallet moving mechanism 9 has a slide means 91 that receives the rotational force of the drive source 5b and expands and contracts while sliding towards the processing table, and roller units 92, 92 that support the pallet P at both ends in the X-axis direction and guide its movement in the Y-axis direction.

[0038] Fig. 5 is an enlarged view of the slide means 91 in Fig. 4. The slide means 91 uses three linear guide mechanisms 114, 124, 134 and three rack-and-pinion mechanisms 110, 120, 130 each consisting of a rack gear and a pinion gear to convert the rotational force generated by the drive source into linear motion in the Y-axis direction, and can load and unload the pallet P in three stages. The pallet movement mechanism has a pinion gear 7' that transmits the rotational force of the drive source, a first moving member 11, a second moving member 12, and a third moving member 13, which work together to transmit force while alternately converting the form of motion between rotational motion and linear motion, thereby allowing the pallet P to be loaded and unloaded to a processing table that is far away compared to the size of the pallet transport means 3.

[0039] In the case of conventional shuttle-type pallet transport means, particularly chain-driven pallet transport means, the size of the pallet transport mechanism tends to be large, making it difficult for workers to access the processing equipment. In contrast, the above-mentioned pallet transport mechanism has a slide means that feeds the linear guide mechanism, which serves as the transport arm, in three stages, making it possible to reduce the size of the pallet transport means and providing excellent accessibility. This contributes to the miniaturization of the pallet exchange device and also provides excellent workability in the installation of the device and centering work. In particular, when the opening (entrance space) of the processing equipment is small and the depth of the processing table of the processing equipment is deep, the above-mentioned pallet transport mechanism is particularly preferable because it is small but can transfer pallets between the processing table and a distant processing table.

[0040] Specific movements of the pallet moving mechanism 9 shown in Fig. 5 will be described below. The first moving member 11 has a rack gear 118 having a plurality of teeth that engage with the teeth of the pinion gear 7', a linear motion guide mechanism 114, and a pinion gear 117. When the pinion gear 7' of the first moving member 11 rotates, the rack gear 118, a block of the linear motion guide mechanism 114, and the pinion gear 117 move integrally in the Y-axis direction, generating a rotational movement of the pinion gear 117.

[0041] The second moving member 12 has a rack gear 128 having a plurality of teeth that engage with the teeth of the pinion gear 117, a linear motion guide mechanism 124, and a pinion gear 127. When the pinion gear 117 rotates, the second moving member 12 has the rack gear 128, a block of the linear motion guide mechanism 124, and the pinion gear 127 move integrally in the Y-axis direction, generating a rotational motion of the pinion gear 127.

[0042] The third moving member 13 has a rack gear 138 having a plurality of teeth that engage with the teeth of the pinion gear 127, a linear motion guide mechanism 134, and a connecting member 131 that is connected to the pallet P to transmit force. When the pinion gear 127 rotates, the third moving member 13 moves integrally with the rack gear 138, the block of the linear motion guide mechanism 134, and the connecting member 131 in the Y-axis direction. In this way, the rotational force generated by the drive source is converted into a three-stage extension / retraction movement in the Y-axis direction, allowing the pallet to be loaded and unloaded.

[0043] The above-described embodiments are merely examples of the present invention, and the present invention is not limited to these embodiments. [Industrial Applicability]

[0044] Since the pallet exchange device of the present invention allows an operator to easily access the opening of the machine tool, it is particularly useful as a pallet exchange device for machine tools having relatively small openings that make it difficult for an operator to enter inside the machine tool. [Explanation of symbols]

[0045] 1 Pallet exchange device 2. Chassis 21a, 21b, 22 frames 23 Steps 24 Adjustment parts 3 Pallet transport means 4, 114, 124, 134 Linear guide mechanism 41 Rail 42 blocks 5a, 5b Driving source 6 Connection parts 7, 7', 117, 127 Pinion gear 8, 118, 128, 138 Rack Gear 9 Pallet movement mechanism 91 Slide means 92 Roller section 11 First moving member 12 Second moving member 13 Third moving member 131 Connecting member 110, 120, 130 Rack and pinion mechanism A Opening C Pallet exchange position F Floor G raceway groove H Standby position M machine tool Op Worker P Palette R protrusion S Rotation axis W processing table

Claims

1. A pallet exchange device comprising a pallet transport means adjacent to a machine tool, movable between a pallet exchange position facing an opening of the machine tool and a standby position spaced from the pallet exchange position, and for delivering and receiving pallets between the pallet transport means and a processing table of the machine tool, A pallet exchange device characterized in that the pallet transport means is provided with a linear guide mechanism on the side of the machine tool which enables movement in a direction crossing the pallet exchange position.

2. the pallet transport means has a pallet moving mechanism that enables the transfer of the pallet to and from the processing table in a linear manner, 2. A pallet exchange device according to claim 1, wherein said pallet moving mechanism has a slide means extending toward said processing table in three stages.

3. 3. A pallet exchange device according to claim 2, wherein said pallet transport means comprises a drive source for moving in a direction crossing the pallet exchange position, and a drive source for said pallet moving mechanism.

4. 4. A pallet exchange device according to claim 3, wherein said pallet transport means has at least one servo motor as said drive source.

5. 3. A pallet exchange device according to claim 1, wherein the pallet exchange device is adjacent to a machine tool having a window for introducing a pallet as the opening.

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