JP5279542B2 - Machine Tools - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect the negative pressure for sucking a workpiece to a workpiece mounting stand attached to a table by a pressure detector provided on the table side without providing any negative pressure feed line on the table of a machine tool. <P>SOLUTION: A machine tool includes a suction line 33 which is formed on a workpiece mounting stand 23 and opened in a workpiece mounting face of the workpiece mounting stand 23, an ejector 27 which is provided on the workpiece mounting stand 23 to generate the negative pressure and to feed the generated negative pressure to the suction line 33, a negative pressure checking line 67 provided on the table 21, and a pressure detector 65 connected to the negative pressure checking line 67. When the workpiece mounting stand 23 is attached to the table 21, a communication line 45 branched from the suction line 33 is connected to the negative pressure checking line 67 extending from the pressure detector 65. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a machine tool on which a work mounting base is detachably mounted on a table.

  In a machine tool, a workpiece is fixed to a table using a chuck or the like for processing. At this time, if only the outer peripheral portion of the thin workpiece is fixed, the center portion of the workpiece is lifted and vibrated during processing, which may adversely affect the processing accuracy. In many cases, the work is fixed to the table by sucking the entire bottom surface of the work using a vacuum chuck having a plurality of suction holes on the chuck face. In this case, it is common to provide a pressure gauge on the chuck and monitor the vacuum pressure to check whether the workpiece is being sucked correctly. In addition, as disclosed in Patent Document 2, the vacuum chuck is configured so that a pipe for suction can be used for gas ejection, and gas is ejected from a vent hole provided in the chuck surface to thereby chuck the chuck surface. Some of the pipes are switched after blown away foreign matter such as processing waste adhering to the workpiece, and the workpiece is sucked and fixed to the chuck surface by sucking air through the vent hole.

  Further, in recent years, in order to automate the processing, a workpiece is previously attached to a pallet having a taper socket and a pull stud, and the pallet taper socket provided on the surface of the table is engaged with the pallet socket for positioning. Increasingly, a pallet is detachably mounted on a table by holding a pull stud of the pallet with a collet provided on the table. In such a case, a pull stud is provided in the taper socket and a collet is often provided in the taper cone. Further, as disclosed in Patent Document 3, when the pallet is replaced, compressed air is ejected from the top of the tapered cone to the space between the surface of the tapered socket and the surface of the tapered cone, so that the surface of the tapered socket and the tapered cone are In some cases, chips or the like adhering to the surface are removed so that the pallet is securely mounted on the table.

JP 2001-287129 A JP-A-5-285765 Japanese Examined Patent Publication No. 4-42124

  When a workpiece is mounted on the table via a workpiece mounting base such as a pallet, the center of the workpiece attached to the workpiece mounting base during processing is used as long as only the outer periphery of the thin workpiece is fixed on the workpiece mounting base. The problem may arise that the vibrations occur due to floating. Therefore, it is desirable to suck the center portion of the workpiece onto the workpiece mounting surface of the workpiece mounting base by suction. Therefore, when an external negative pressure source such as a vacuum pump is connected to the negative pressure supply line provided on the table via a rotary joint, and the work mounting base is mounted on the table, the negative pressure supply line of the table and work attachment By connecting the suction pipe line of the table, the workpiece on the workpiece mounting surface of the workpiece mounting table can be sucked. Further, the pressure of the negative pressure supply line is detected by a pressure detector provided on the table, and the negative pressure in the suction line of the work mounting base is monitored.

  However, if a negative pressure generation source is provided on the table side, a negative pressure supply line for supplying negative pressure to the work mounting base must be provided on the table. It is sucked into the pipe line and causes a problem that the negative pressure supply pipe line is clogged or a seal member provided in the rotary joint is damaged. For this reason, if a filter is provided at the inlet of the negative pressure supply pipe of the table to prevent the problem from occurring, the table will continue to be used without being replaced unlike the work mounting base, and the filter will likely clog. In order to prevent a reduction in suction force, frequent replacement of the filter is necessary. Further, from the viewpoint of suppressing the vacuum loss, it is preferable that the workpiece adsorbing portion and the negative pressure generating source are close to each other. Therefore, it is desirable to provide the negative pressure generating source on the work mounting base and not to provide the negative pressure supply pipe on the table.

  On the other hand, as described above, if the negative pressure generating source is provided on the work mounting base and the negative pressure supply line is not provided on the table, the pressure detector must be provided on the work mounting base. Each time, the signal wiring from the control device must be connected to the pressure detector of the work mounting base. However, in order to automate the work exchange, it is desirable that there is no signal wiring between the work mounting base and the table, and the pressure detector is preferably provided on the table side.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a table by a pressure detector provided on the table side without providing a negative pressure supply pipe on the table of the machine tool. An object of the present invention is to be able to detect a negative pressure for adsorbing a work to a work mounting base attached to the work.

  In order to achieve the above-mentioned object, a machine tool for detachably mounting a work mounting base on a table, which is formed in the work mounting base and opens to a work mounting surface of the work mounting base, and A negative pressure generating device that is provided on the work mount and supplies the negative pressure generated by generating a negative pressure to the suction line, a negative pressure confirmation line provided on the table, and the negative pressure confirmation line When the work mounting base is mounted on the table, the communication line branched from the suction line and the negative pressure confirmation line are connected to each other. A machine tool is provided.

  According to the present invention, since the negative pressure generating device for generating the negative pressure for adsorbing the work is provided on the work mounting base, it is not necessary to provide the negative pressure supply pipe on the table. Further, when the work mounting base is mounted on the table, the communication pipe branching from the suction pipe provided on the work mounting base and the negative pressure confirmation pipe provided on the table are connected. Even if a negative pressure generating device is provided, the negative pressure in the suction pipe that attracts the work to the work mounting base can be detected by the pressure detector provided on the table side through the communication pipe and the negative pressure check pipe. it can.

  The machine tool further includes a compressed air source for supplying compressed air to the table side, the negative pressure generating device is an ejector for generating negative pressure using the compressed air, and the work mounting base is mounted on the table It is preferable that the ejector is connected to a compressed air supply line extending from the compressed air source.

  In addition, a positioning member that engages with each other is provided on the bottom surface of the work mounting base and the surface of the table. When the work mounting base is mounted on the table, the positioning member is engaged. Preferably, the work mounting base is positioned with respect to the table.

  The communication pipe line extends to the positioning member of the work mounting base, the negative pressure check pipe line extends to the positioning member of the table, and the positioning member of the work mounting base and the positioning member of the table are engaged. More preferably, the communication line and the negative pressure confirmation line are connected when they are combined.

  In addition, an on-off valve that selectively connects the negative pressure confirmation pipeline to the compressed air source may be provided.

  According to the present invention, even if a negative pressure generating device is provided on the work mounting base, the negative pressure of the suction pipe for adsorbing the work to the work mounting base through the communication pipe and the negative pressure confirmation pipe is on the table side. Since it can be detected by the pressure detector provided, it is possible to detect the negative pressure for adsorbing the work on the work mounting base by the pressure detector provided on the table side without providing a negative pressure supply line on the table. it can. Therefore, when the work mounting base is mounted on the table, it is not necessary to connect signal wiring, and it becomes easy to automate the work replacement, and it is not necessary to provide the table with a filter that requires frequent replacement.

It is the schematic which shows the structure of the table of a machine tool and the workpiece mounting base by the 1st Embodiment of this invention. It is a top view of the adsorption | suction plate of the workpiece mounting base shown by FIG. It is the schematic which shows the structure of the table of a machine tool and the workpiece mounting base by 2nd Embodiment by this invention. It is an enlarged view of the engaging part of the table shown in FIG. 3, and a workpiece mounting base. 1 is an overall configuration diagram of a machine tool according to the present invention.

Hereinafter, an embodiment of a machine tool of the present invention will be described with reference to the drawings.
Initially, with reference to FIG. 5, the whole structure of the machine tool by this invention is demonstrated. The machine tool 11 can be a horizontal machining center, for example, and is erected so as to be movable in the X-axis direction (perpendicular to the plane of FIG. 5) with respect to the bed 13 fixed to the floor surface. And a spindle head 17 provided on the front surface of the column 15 so as to be movable in the Y-axis direction (vertical direction in FIG. 5). The spindle head 17 rotatably supports the spindle 19, and a tool T is held at the tip of the spindle 19 via a tool holder (not shown). On the bed 13, a table 21 that is movable in the Z-axis direction (left-right direction in FIG. 5) perpendicular to the X-axis and the Y-axis is provided to face the column 15, and on the table 21, A workpiece mounting base 23 to which the workpiece W is mounted is detachably mounted. The table 21 may be a rotary table. The work mounting base 23 is for fixing the work W to the table 21, and includes a pallet, a scale, a rotary table, a combination thereof, and the like.

  In the above description, the machine tool 11 is described as a horizontal machining center. However, the machine tool may be in other forms such as a vertical machining center. Further, it has been described that the column 15 is movable in the X-axis direction, the spindle head 17 is movable in the Y-axis direction, and the table 21 is movable in the Z-axis direction. However, the machine tool 11 moves the tool T and the workpiece W at least on the X-axis. It is only necessary to be able to move relative to each other in the three orthogonal directions of the Y axis and the Z axis, and is not limited to the above embodiment.

  The work mounting base 23 is provided with a negative pressure generating device for generating a negative pressure, a suction pipe connecting the negative pressure generating device and the work mounting surface, and a communication pipe branched from the suction pipe. In addition, the workpiece W can be attracted and fixed to the workpiece mounting surface of the workpiece mounting base 23 by suction through the suction pipe using the negative pressure generated by the negative pressure generator. A vacuum pump or an ejector can be used as the negative pressure generator.

  On the other hand, the table 21 is provided with a pressure detector for detecting the pressure and a negative pressure confirmation conduit extending from the pressure detector. When the work mounting base 23 is mounted on the table 21, the work mounting is performed. The communication line of the table 23 is connected to the negative pressure confirmation line. The output from the pressure detector is connected to a control device (not shown), and the suction force (negative pressure) is monitored. When the suction force is out of a predetermined range, the workpiece mounting base 23 is connected to the workpiece. It is determined that W is not properly adsorbed, and an alarm is issued. For example, when the workpiece W is not in close contact with the workpiece mounting surface, the suction force is reduced and deviates from a predetermined range. The pressure detector only needs to be able to detect that the pressure is within a predetermined range, and may be a pressure gauge capable of measuring the pressure, and emits a signal when the pressure is within the predetermined range. It may be a pressure switch. Although the pressure detector is described as being provided on the table side, this means that it is provided on the machine body side such as a bed, a splash guard, and a control panel in addition to the table.

  As described above, in the machine tool of the present invention, since the negative pressure generating device for generating the negative pressure used for adsorption of the workpiece is provided on the workpiece mounting base, the surface of the table on which the workpiece mounting base is detached is attached. There is no need to form a suction line. Therefore, when the workpiece mounting base is removed from the table, the processing waste and the processing liquid are not sucked into the suction pipe provided on the table, and a filter provided at the inlet of the suction pipe is not necessary. Also, when the work mount is mounted on the table, the communication line and the negative pressure check line are connected, and the suction force of the work on the work mount is detected by a pressure detector that is provided on the table side and is always connected to the controller. (Negative pressure) can be detected. Therefore, it is possible to detect the suction pressure of the workpiece on the workpiece mounting table without providing a pressure detector on the workpiece mounting table that is attached to and detached from the table, and it is not necessary to attach or remove signal wiring between the workpiece mounting table and the table. .

With reference to FIG. 1, the structure of the table 21 and the workpiece mounting base 23 of the machine tool 11 by the 1st Embodiment of this invention is demonstrated.
The work mount 23 is provided with an ejector 27 for generating negative pressure by converting velocity energy through which compressed air flows into pressure energy as a negative pressure generating device. The ejector 27 flows in compressed air from an inlet 27a. By exhausting from the outlet 27b, a negative pressure is generated at the suction port 27c. A compressed air supply conduit 29 for supplying compressed air is connected to the inlet 27a of the ejector 27, and a silencer 31 for noise reduction is connected to the outlet 27b. Further, a suction conduit 33 is connected to the suction port 27 c, and the suction conduit 33 extends to a suction plate 47 attached to the side surface of the work mounting base 23 facing the main shaft 19. In order to prevent failure of the ejector 27 due to the processing liquid or processing waste, the suction pipe 33 may cause processing waste or processing liquid to enter due to suction. A filter 35 is installed in the middle of the suction pipe 33 so that the processing liquid and the processing waste that have entered the suction pipe 33 are captured before the ejector.

  A plurality of taper sockets 41 including a recess 39 having a tapered inner peripheral surface 37 and a clamp mechanism (not shown) are provided on the bottom surface of the work mounting base 23 as positioning members. Further, a compressed air supply pipe 29 extending from the inlet 27a of the ejector 27 and a communication pipe 45 branched from the suction pipe 33 extending from the suction port 27c of the ejector 27 are opened on the bottom surface of the work mounting base 23, respectively. ing.

  As shown in FIG. 2, a lattice-like groove 49 is formed on the work attachment surface 47a of the suction plate 47 inside a region (work attachment region) 47b to which the workpiece W can be attached. A suction line 33 extending from the ejector 27 is opened in the groove 49. Further, an annular seal portion 51 that defines a suction area is provided on the work mounting surface 47a of the suction plate 47 so as to surround the outside of the lattice-shaped groove 49, and the work W is sucked to the work mounting surface 47a. In this case, the adsorption area is sealed to prevent air from entering the adsorption area from the surroundings, thereby improving the adsorption property. The outer periphery of the workpiece W is clamped to the suction plate 47 with a fastener (not shown).

  On the other hand, a taper cone 55 having a tapered outer peripheral surface 53 complementary to the tapered inner peripheral surface 37 of the taper socket 41 of the work mounting base 23 is provided on the upper surface of the table 21. , The concave portion 39 of the taper socket 41 of the work mounting base 23 receives the taper cone 55 of the table 21, and the taper inner peripheral surface 37 of the taper socket 41 engages with the taper outer peripheral surface 53 of the taper cone 55. The mounting base 23 is positioned on the table 21. The positioned work mounting base 23 is held and fixed to the table 21 by a clamp mechanism (not shown). As the clamp mechanism, a known appropriate clamp mechanism can be used, and therefore will not be described in detail here. However, it is preferable to use a clamp mechanism constituted by a pull stud and a collet as described later in the second embodiment.

  On the upper surface of the table 21, two couplers 63a and 63b that are urged upward by urging springs 61a and 61b and can be moved up and down are provided. One connector 63a is connected to a negative pressure confirmation conduit 67 connected to a pressure detector 65 for detecting pressure, and the other connector 63b is connected to a compressed air supply conduit 71 extending from a compressed air source 69. An open / close valve for opening and closing the compressed air supply pipe 71 is provided in the middle of the compressed air supply pipe 71. A solenoid valve 73 is used as the on-off valve. When the work mounting base 23 is mounted on the table 21 while being positioned by the engagement between the taper socket 41 of the work mounting base 23 and the taper cone 55 of the table 21, the two couplers 63a and 63b are moved by the biasing springs 61a and 61b. Energized upward and pressed against the bottom surface of the work mounting base 23, the coupler 63b is automatically engaged and connected to the end of the compressed air supply line 29 that opens to the bottom surface of the work mounting base 23. The coupler 63a is automatically engaged and coupled to the end of the communication conduit 45 that opens to the bottom surface of the work mount 23.

  When the work mounting base 23 is mounted on the table 21 shown in FIG. 1, first, the taper socket 41 of the work mounting base 23 and the taper cone 55 of the table 21 are roughly aligned to engage with each other. After the work mounting base 23 is arranged at a predetermined position on the table 21 by the cooperation of the taper inner peripheral face 37 and the taper outer peripheral face 53 of the taper cone 55, the work mounting base 23 is moved by a clamp mechanism (not shown). It is fixed to the table 21. At the same time, the two couplers 63a and 63b of the table 21 are pressed against the ends of the compressed air supply pipe 29 and the communication pipe 45 that open to the bottom surface of the work mounting base 23, respectively, and are automatically engaged and connected. . Since the compressed air supply pipe 29 of the work mount 23 and the connector 63b are connected, the compressed air supply pipe 71 of the table 21 and the compressed air supply pipe 29 of the work mount 23 communicate with each other through the connector 63b. When the solenoid valve 73 is opened, compressed air is supplied from the compressed air source 69 to the ejector 27 through the compressed air supply pipes 71 and 29, and a negative pressure is generated at the suction port 27c of the ejector 27. The generated negative pressure is supplied to the suction plate 47 through the suction pipe 33, and the work W is sucked to the suction plate 47. Further, by connecting the communication pipe 45 branched from the suction pipe 33 and the coupler 63a, the communication pipe 45 and the negative pressure confirmation pipe 67 of the table 21 communicate with each other through the coupler 63a. Since the pressure 67 becomes equal to the pressure in the suction line 33, the pressure (negative pressure) in the suction line 33 can be detected by the pressure detector 65 provided in the table 21. A control device (not shown) monitors the pressure in the suction line 33, and if the pressure detected by the pressure detector 65 deviates from a predetermined range, it is determined that an abnormality has occurred in the adsorption, and an alarm is issued. To emit.

  Next, with reference to FIG.3 and FIG.4, the structure of the table 21 and the workpiece mounting base 23 of the machine tool 11 by the 2nd Embodiment of this invention is demonstrated. 3 and 4, the same reference numerals are given to the portions common to FIG. 1.

  The table 21 ′ and the work mounting base 23 ′ of the embodiment shown in FIG. 3 are mainly used for the communication pipe 45 and the negative pressure confirmation pipe 67 in the table 21 and the work of the machine tool 11 according to the first embodiment. Since it is different from the mounting base 23 and other configurations are the same as those of the table 21 and the work mounting base 23 of the machine tool according to the first embodiment, only different parts will be described here.

  In the second embodiment shown in FIG. 3, the communication pipe line 45 of the work mounting base 23 ′ opens in the recess 39 of the taper socket 41 instead of the bottom surface of the work mounting base 23 ′. An on-off valve that opens and closes according to the pressure of the compressed air supply line 29 of the work mounting base 23 ′ is provided in the middle of the path 45. As the on-off valve, an air operated valve 75 is used. The air operated valve 75 opens when the pressure of the compressed air supply line 29 becomes higher than a predetermined pressure, and closes when the pressure becomes lower than a predetermined pressure. Is set to On the other hand, the upper surface of the table 21 ′ is connected to a compressed air supply pipe 71 extending from the compressed air source 69 at a position corresponding to the end of the compressed air supply path 29 that opens to the bottom surface of the work mount 23 ′. Only the coupler 63b biased by the biasing spring 61b is provided.

  In the second embodiment, the negative pressure confirmation pipe 67 of the table 21 ′ is also used for injecting cleaning air to the positioning engagement portion including the taper socket 41 and the taper cone 55. For this purpose, the negative pressure confirmation pipe 67 connected to the pressure detector 65 is also connected to the compressed air source 69 and on the negative pressure confirmation pipe 67 closer to the compressed air source 69 than the pressure detector 65. Is provided with an on-off valve that opens and closes the negative pressure confirmation pipe 67 in accordance with the pressure of the compressed air pipe 71. An air operated valve 77 is used as the on / off valve. The air operated valve 77 is closed when the pressure in the compressed air supply passage 71 on the downstream side of the on / off valve (solenoid valve 73) becomes higher than a predetermined pressure. , It is set to open when the pressure falls below a predetermined pressure.

Here, with reference to FIG. 4, the detailed structure of the positioning engagement part which consists of the taper socket 41 of work mounting base 23 'and the taper cone 55 of table 21' is demonstrated.
Each tapered socket 41 of the work mounting base 23 ′ includes a recess 39 having a tapered inner peripheral surface 37, and a pull stud 43 protrudes from the center of the recess 39. Further, in the concave portion 39 of the taper socket 41, a communication pipe line 45 extending from the suction pipe line 33 is opened. On the other hand, the taper cone 55 of the table 21 ′ has a taper outer peripheral surface 53 complementary to the taper inner peripheral surface 37 of the taper socket 41. 59 is fitted to be slidable in the vertical direction. Further, a piston portion 81 that is accommodated in a cylinder chamber 79 formed below the collet 59 is formed at the lower end of the collet 59, and the cylinder chamber 79 is connected to the cylinder chamber 79 from a working fluid supply path 83 a that opens to the upper portion of the cylinder chamber 79. By supplying a working fluid such as hydraulic oil to the piston, the piston portion 81 is moved downward to lower the collet 59, while the working fluid is supplied to the cylinder chamber 79 from the working fluid supply path 83b opened at the lower portion of the cylinder chamber 79. By supplying, the collet 59 can be pushed up by moving the piston portion 81 upward.

  A center hole 85 is formed in the collet 59. The center hole 85 is formed at the uppermost part to receive and hold the pull stud 43, and is formed below the holding hole 85a. An intermediate hole 85b having a small diameter, a pore 85c formed below the intermediate hole 85b and having a smaller diameter than the intermediate hole 85b, and a lower hole formed below the pore 85c and having a larger diameter than the pore 85c. 85d. Since the lower hole 85d passes through the piston portion 81, the lower end surface of the piston portion 81 is sealed by a lower cover 87 fixed by screws. The collet 59 is provided with a ball 89 for clamping in a ball hole formed at the upper end, and the ball 89 for clamping is in an annular groove 91 formed in the upper part of the central vertical hole 57 of the tapered cone 55 when not clamped. Evacuate.

  Further, between the central hole 85 of the collet 59 and the negative pressure confirmation pipe 67, a connection path 93 a formed in the tapered cone 55, an inner peripheral surface of the central vertical hole 57 of the tapered cone 55, and an outer peripheral surface of the collet 59 are formed. The annular passage 93b formed by the annular groove, and the connection passage 93c that connects the annular passage 93b and the center hole 85 of the collet 59 communicate with each other. Accordingly, when the work mounting base 23 ′ is mounted on the table 21 ′ and the taper socket 41 and the taper cone 55 are engaged, a space 95 between the inner surface of the taper socket 41 and the outer surface of the taper cone 55, a collet 59. Through the center hole 85, the connection path 93a, the annular path 93b, and the connection path 93c, the communication line 45 and the negative pressure confirmation line 67 of the work mounting base 23 'communicate with each other. Further, when the work mounting base 23 ′ is mounted on the table 21 ′, when there is a gap between the taper inner peripheral surface 37 of the taper socket 41 and the taper outer peripheral surface 53 of the taper cone 55, the negative pressure confirmation pipeline 67 If the compressed air is supplied, the compressed air is ejected from the center hole 85 to the space between the inner surface of the taper socket 41 and the outer surface of the taper cone 55, and adheres to the inner surface of the taper socket 41 and the outer surface of the taper cone 55. Chips and the like can be removed.

  The center hole 85 of the collet 59 is inserted into the cover member 97, a support rod 99 extending from below the cover member 97 and having a diameter slightly smaller than the pore 85 c of the collet 59, and the support rod 99. A coil spring 101 having a lower end seated on a shoulder portion formed at a boundary portion between the intermediate hole 85b and the micro hole 85c and an upper end locked to the cover member 97 is disposed. It is preferable that the upper opening of the grip hole 85 a of the collet 59 is closed by the cover member 97 by urging upward. In this case, a stopper screw 103 having a head having a diameter larger than the hole 85c of the collet 59 is attached to the lower end of the support rod 99, and the head of the stopper screw 103 is attached to the hole 85c and the lower hole 85d of the collet 59. It is preferable that the upper surface of the cover member 97 forms a conical convex surface that is continuous with the tapered outer peripheral surface of the tapered cone 55 when contacting the shoulder portion formed at the boundary portion. Thus, if the upper opening of the center hole 85 of the collet 59 is closed when the cover member 97 is pushed upward by the biasing force of the coil spring 101, the workpiece mounting base 23 'can be replaced. Chips and the like are prevented from falling into the center hole 85 of the collet 59. On the other hand, when the cover member 97 is pressed by the pull stud 43, the coil spring 101 is compressed, the cover member 97 is lowered together with the support rod 99 in the center hole 85, and the grip hole 85a of the collet 59 is opened. The pull stud 43 can be received in 85a.

  When the cover member 97 is provided, air flow between the outer peripheral surface of the cover member 97 and the inner peripheral surface of the gripping hole 85a when the coil spring 101 is compressed and the cover member 97 is lowered in the gripping hole 85a. When the cover member 97 is lowered, the communication between the communication line 45 and the negative pressure confirmation line 67 and the compressed air from the top of the taper cone 55 are allowed to exist. The injection can be prevented.

Next, operations of the table 21 ′ and the work mounting base 23 ′ of the machine tool 11 of the second embodiment shown in FIG. 3 will be described.
When the work mount 23 'is not mounted on the table 21', the compressed air supply pipe 29 of the work mount 23 'and the compressed air supply pipe 71 of the table 21' are not connected. In response to this command, the solenoid valve 73 is closed, and the supply of compressed air from the compressed air source 69 to the compressed air supply pipe 71 on the downstream side of the solenoid valve 73 is stopped. At this time, since the pressure is reduced in the compressed air supply pipe 71 on the downstream side of the solenoid valve 73, the air operated valve 77 is opened so that compressed air is supplied from the compressed air source 69 to the negative pressure confirmation pipe 67. Become. When the work mounting base 23 ′ and the table 21 ′ approach and the pull stud 43 presses the cover member 97 and lowers the cover member 97 against the urging force of the coil spring 101, the negative pressure confirmation pipe 67 is reached. The supplied compressed air is jetted from the top of the tapered cone 55 to the space between the inner surface of the concave portion 39 of the tapered socket 41 and the outer surface of the tapered cone 55 through the connecting path 93a, the annular path 93b, the connecting path 93c and the center hole 85. In addition, a cleaning effect is provided that removes processing dust and the like attached to the inner surface of the recess 39 of the tapered socket 41 and the outer surface of the tapered cone 55 and the cover member 97. Further, in this state, compressed air is not supplied to the compressed air supply passage 29 of the work mounting base 23 ′, and the pressure of the compressed air supply conduit 29 is lowered, so that the air operated valve 75 is closed and tapered. Compressed air does not flow into the communication conduit 45 that opens to the recess 39 of the socket 41. Thereby, it is prevented that the compressed air injected between the inner surface of the recessed part 39 of the taper socket 41 and the outer surface of the taper cone 55 flows into the communication pipe 45 and the cleaning effect is deteriorated.

  When the work mounting base 23 ′ and the table 21 ′ are further brought closer, the taper socket 41 of the work mounting base 23 ′ and the taper cone 55 of the table 21 ′ are engaged, and the work mounting base 23 ′ is placed on the table 21 ′. It is arranged at a predetermined position. At this time, the pull stud 43 of the work mounting base 23 ′ lowers the cover member 97 to open the gripping hole 85 a of the collet 59 and is received in the gripping hole 85 a of the collet 59. Next, by supplying the working fluid from the working fluid supply passage 83a to the cylinder chamber 79 of the tapered cone 55, the piston portion 81 is moved downward to lower the collet 59. Then, the clamping ball 89 accommodated in the ball hole of the collet 59 is pulled out from the annular groove 91 formed in the upper part of the central vertical hole 57 of the tapered cone 55 and is received in the holding hole 85a of the collet 59. Engage with 43 and grip and fix it.

  When the pull stud 43 of the work mounting base 23 'is gripped and fixed to the collet 59 of the table 21' and the work mounting base 23 'is mounted on the table 21', the compressed air opened to the bottom surface of the work mounting base 23 '. A coupler 63b protruding from the upper surface of the table 21 'is connected to the supply pipe 29, and the compressed air supply pipe 29 of the work mounting base 23' and the compressed air supply pipe 71 of the table 21 'are connected. In this state, the solenoid valve 73 is opened by a command from the control device, and the work is passed from the compressed air source 69 through the compressed air supply line 71 of the table 21 'and the compressed air supply line 29 of the work mount 23'. When compressed air is supplied to the ejector 27 of the mounting base 23 ′, a negative pressure is generated on the suction port 27 c side of the ejector 27, and the workpiece W fixed on the suction plate 47 is transferred to the suction plate 47 through the suction conduit 33. Adsorb.

  Further, when compressed air is supplied to the compressed air supply pipe 71 of the table 21 ′, the pressure in the compressed air supply pipe 71 on the downstream side of the solenoid valve 73 is increased, so that the air operated valve 77 is closed and negative pressure is applied. Compressed air is not supplied to the pressure confirmation pipe 67. Further, when compressed air is supplied to the compressed air supply line 29 of the work mount 23 ', the pressure of the compressed air supply line 29 of the work mount 23' increases, so the air operated valve 75 is opened, The suction line 33 of the work mount 23 'and the negative pressure confirmation line 67 of the table 21' communicate with each other so that their pressures are equal. As a result, the suction force (negative pressure) of the suction conduit 33 of the work mounting base 23 ′ can be detected by the pressure detector 65 of the table 21 ′.

  When machining is started, the suction force for attracting the workpiece W to the suction plate 47 of the workpiece mounting base 23 ′ is constantly monitored by the pressure detector 65, and abnormalities such as malfunction of the ejector 27 and defective sealing of the suction plate 47 are detected. The occurrence can be detected.

  When the processing is completed, the monitoring of the suction force for attracting the workpiece W to the suction plate 47 of the workpiece mounting base 23 ′ is stopped, the solenoid valve 73 is closed, and the compressed air is supplied to the ejector 27 through the compressed air supply paths 71 and 29. Supply is stopped. Then, the pressure in the compressed air supply passage 71 of the table 21 ′ on the downstream side of the solenoid valve 73 is lowered, the air operated valve 77 is opened, and the compressed air is supplied to the negative pressure confirmation conduit 67. The pressure of the compressed air supply path 29 of the work mount 23 ′ is lowered, the air operated valve 75 is closed, and the compressed air does not flow into the communication pipe 45. Accordingly, compressed air is supplied to the positioning engagement portion between the taper socket 41 of the work mounting base 23 ′ and the taper cone 55 of the table 21 ′, and the positioning engagement portion is cleaned and the table 21 ′ is cleaned. It becomes possible to detach the work mounting base 23 '.

  Although the present invention has been described based on the illustrated embodiment, the present invention is not limited to the illustrated embodiment. For example, in the illustrated embodiment, the configuration of the present invention is applied to a machining table, but the configuration of the present invention can also be applied to a setup table. In this case, the basic configuration is the same, but when the work is removed in use, the solenoid valve 73 is closed to stop the supply of compressed air to the ejector 27, and a new work W is placed on the work mounts 23 and 23 '. It is also possible to restart the supply of compressed air to the ejector 27 by opening the solenoid valve 73 after the attachment. Thereby, in the setup station, the suction force can be monitored by the pressure detector 65 and it can be confirmed whether the workpiece W is correctly installed on the suction plate 47.

DESCRIPTION OF SYMBOLS 11 Machine tool 21,21 'Table 23,23' Work mounting base 27 Ejector 29 Compressed air supply line 41 Tapered socket 45 Communication line 55 Taper cone 65 Pressure detector 67 Negative pressure confirmation line 69 Compressed air source 71 Compressed air supply Pipe W Work

Claims (5)

A machine tool for detachably mounting a work mounting base on a table,
A suction pipe formed on the work mounting base and opening to a work mounting surface of the work mounting base;
A negative pressure generating device that is provided on the work mounting base and supplies the suction pipe with a negative pressure generated by generating a negative pressure;
A negative pressure check line provided on the table;
A pressure detector connected to the negative pressure confirmation line;
A communication pipe branched from the suction pipe and the negative pressure check pipe are connected when the work mounting base is mounted on the table. machine.   Further comprising a compressed air source for supplying compressed air to the table side, the negative pressure generating device is an ejector that generates a negative pressure using compressed air, and when the work mounting base is mounted on the table, The machine tool according to claim 1, wherein a compressed air supply line extending from the compressed air source and the ejector are connected.   Positioning members that engage with each other are provided on the bottom surface of the work mounting base and the surface of the table, respectively, and when the work mounting base is mounted on the table, the positioning member is engaged, The machine tool according to claim 1, wherein the work mounting base is positioned with respect to a table.   The communication pipe line extends to the positioning member of the work mounting base, the negative pressure check pipe line extends to the positioning member of the table, and the positioning member of the work mounting base and the positioning member of the table are engaged. The machine tool according to claim 3, wherein the communication line and the negative pressure confirmation line are connected when they are combined.   The machine tool according to claim 4, wherein an open / close valve is provided to selectively connect the negative pressure confirmation pipeline to the compressed air source.

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