JP2006106849A - Machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a machine tool whose main spindle can be prevented from erroneously rotating when a tool is un-clamped. <P>SOLUTION: When a main spindle un-clamp mechanism is determined to be valid (S2: YES) and a normal mode is set (S3: YES), and when a tool is un-clamp (tool clamp sensor is ON) (S4: YES), that is, when an un-clamp ring is pushed down by a cam follower at the top end of the short arm part of a swing arm, and a draw bar and a collet are descended, and the tool is released, when an operation mode is a manual mode (S5: YES), and when a main spindle normal rotation key is depressed (S6: YES), a message indicating that "main spindle tool un-clamp (sensor 1)" is displayed, and an alarm is generated, and the rotating operation of the main spindle is not performed (S13). <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a machine tool, and more particularly, to a machine tool including a tool clamp that detachably holds various tools on a spindle.

  Conventionally, a main shaft incorporating a tool clamping mechanism having a collet that detachably holds various tools, a frame for reciprocally supporting the main shaft in the axial direction of the main shaft, a tool magazine storing a plurality of tools, There is known a machine tool including a tool changer for selecting one of tools stored in a tool magazine and exchanging with a tool mounted on a spindle.

  In a machine tool such as that described above, in order to replace a tool with a new tool when the tool is damaged, the damaged tool must be reinserted into the tool magazine by a tool changer and then a new tool must be mounted on the spindle. It took time to recover. Further, when the motor for driving the tool clamping mechanism driving cam fails, it is necessary to manually unclamp the tool mounted on the spindle by rotating the driving shaft of the tool clamping mechanism driving cam manually. There was a lot of trouble. Therefore, a machine tool including a tool changer that can clamp and unclamp the tool regardless of the action of the cam that drives the tool clamping mechanism has been proposed (for example, see Patent Document 1). In the machine tool described in Patent Document 1, when a tool is exchanged due to tool breakage or the like, when the switch is turned on by the operator and the hydraulic cylinder is driven, it is pivotally supported by a horizontal axis. The hydraulic cylinder applies a force to one end of the rod, and the tool release pin is pressed from above with a Y-shaped portion formed on the tip of the one end, and the other end of the rod is cantilevered. The part is lifted up against the biasing force of the spring, and the engagement with the rod is released. As a result, the draw bar is pushed down, the collet descends, each ball of the collet escapes in the taper part radial direction below the collet chamber, and the pull stud can freely pass through the collet and the tool is unclamped. Can be removed from the spindle.

Further, in the machine tool described in Patent Document 1, when the tool replacement is completed, when the switch is turned off by the operator, the thrust to the end of the rod by the hydraulic cylinder is removed. The tool release pin is lifted by the compressive force of the group of disc springs located below, and at the same time, the draw bar is also pushed up, the collet is raised, and each ball is pressed by the tapered portion below the collet chamber. Then, the balls move toward the center, and a plurality of balls pull the pull studs up. This clamps the tool to the collet.
JP-A-7-164214

  However, in the machine tool described in Patent Document 1, when the operator turns on the switch to unclamp the tool and the tool replacement is completed, the operator turns off the switch and clamps the tool. ing. Therefore, if the operator forgets to turn off the switch and rotates the spindle, the spindle rotates with the rod pressing the tool release pin from above, and the spindle is damaged.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a machine tool in which the main shaft does not rotate excessively when the tool is unclamped.

  In order to achieve the above object, a machine tool according to a first aspect of the present invention includes a main shaft including a tool clamp that detachably holds various tools, a clamp opening / closing mechanism that opens and closes the tool clamp, and a rotating main shaft. A spindle motor for driving, a spindle head for holding the spindle motor, a tool magazine storing a plurality of tools, a tool held by the tool clamp, and a tool changer for exchanging the tools stored in the tool magazine A clamp state detecting means for detecting whether the tool clamp is in an unclamped state where no tool is held, and the tool clamp is in an unclamped state by the clamp state detecting means. And a spindle rotation prohibiting means that does not rotate the spindle by the spindle motor when detected.

  In the machine tool of the invention according to claim 2, in addition to the configuration of the invention of claim 1, tool unclamp instruction means for instructing the clamp opening / closing mechanism to put the tool clamp in an unclamped state. In the state instructed by the tool unclamp instruction means to put the tool clamp in an unclamped state, the clamp opening / closing mechanism places the tool clamp in an unclamped state, and the tool unclamp instruction means In a state where the tool clamp is not instructed to be in an unclamped state, the clamp opening / closing mechanism places the tool clamp in a clamped state for holding a tool.

  Further, in the machine tool of the invention according to claim 3, in addition to the configuration of the invention of claim 1 or 2, when the tool unclamp instruction means instructs to put the tool clamp in an unclamped state And an alarm means for generating an alarm when the clamp state detecting means detects that the tool clamp is in an unclamped state.

  Further, in the machine tool of the invention according to claim 4, in addition to the configuration of the invention according to any one of claims 1 to 3, the clamp opening / closing mechanism includes a cylinder in which the movable shaft can be retracted, and a substantially L-shape. A swing arm that is formed, has a bent portion pivotally supported, and has one end rotated by a drive shaft of the cylinder, and a ring member that is provided on the main shaft and abuts and pushes down on one end of the swing arm, The clamp state detection means detects whether or not the tool clamp is in an unclamped state in which no tool is held based on the position of the ring member.

  In the machine tool of the invention according to claim 5, in addition to the configuration of the invention according to any one of claims 1 to 3, the clamp opening and closing mechanism includes a cylinder in which the movable shaft can be retracted and a substantially L-shape. A swing arm that is formed, has a bent portion pivotally supported, and has one end rotated by a drive shaft of the cylinder, and a ring member that is provided on the main shaft and abuts against the other end of the swing arm and pushes down. The clamp state detecting means detects whether or not the tool clamp is in an unclamped state in which no tool is held according to the state of the cylinder.

  A machine tool according to a sixth aspect of the invention is characterized in that, in addition to the configuration of the invention according to any of the second to fifth aspects, the tool unclamp instruction means is provided in the vicinity of the main shaft.

  A machine tool according to a seventh aspect of the invention is characterized in that, in addition to the configuration of the invention according to any of the second to sixth aspects, the tool unclamp instruction means is provided in the spindle head.

  Further, in the machine tool of the invention according to claim 8, in addition to the configuration of the invention according to any one of claims 2 to 7, the tool unclamp instruction means is constituted by a mechanical valve switch. .

  In the machine tool according to the ninth aspect of the invention, in addition to the configuration of the invention according to any one of the fourth to eighth aspects, a wedge-shaped cam body extends downward at the tip of the movable shaft of the cylinder. One surface forming the wedge shape of the cam body is in contact with the upper end of the swing arm, and the swing arm is rotated by the movement of the movable shaft of the cylinder. And

  In the machine tool according to the first aspect of the present invention, when the clamp state detecting means detects that the tool clamp is in the unclamped state, the spindle rotation prohibiting means prevents the spindle motor from rotating the spindle. Therefore, it is possible to prevent the spindle from rotating and being damaged when the tool clamp is unclamped.

  Further, in the machine tool of the invention according to claim 2, in addition to the effect of the invention of claim 1, when the tool unclamp instruction means instructs the tool clamp to be in the unclamped state, the clamp The opening / closing mechanism puts the tool clamp in an unclamped state, and the clamp opening / closing mechanism holds the tool clamp in a state where the tool unclamp instruction means is not instructed to put the tool clamp in an unclamped state. Can be in a state.

  In addition, the machine tool according to the third aspect of the invention can do this in addition to the effects of the invention of the first or second aspect. When the tool clamp is instructed to be in an unclamped state, an alarm can be generated by the alarm unit when the clamp state detecting unit detects that the tool clamp is in an unclamped state. Therefore, the operator can be informed of the unclamped state.

  In the machine tool according to the fourth aspect of the present invention, in addition to the effects of the first to third aspects, the clamp state detecting means may be an unscrewed tool holding the tool depending on the position of the ring member. Whether it is in a clamped state can be detected. Accordingly, since it is detected whether or not the clamp opening / closing mechanism that actually operates is in an unclamped state, it is possible to accurately detect whether or not it is in an unclamped state.

  Further, in the machine tool of the invention according to claim 5, in addition to the effects of the inventions of claims 1 to 3, the clamp state detection means determines whether the clamp state is in an unclamped state depending on the state of the cylinder that drives the clamp opening / closing mechanism. Therefore, it is possible to accurately detect whether or not the unclamped state.

  Further, in the machine tool of the invention according to claim 6, in addition to the effect of the invention according to any one of claims 2 to 5, since the tool unclamp instruction means is provided in the vicinity of the main shaft, the unclamp of the tool at the time of maintenance is provided. Easy to give instructions.

  Further, in the machine tool of the invention according to claim 7, in addition to the effect of the invention of any one of claims 2 to 6, since the tool unclamp instruction means is provided in the spindle head, an instruction to unclamp the tool during maintenance is provided. Easy to do.

  In the machine tool according to the eighth aspect of the invention, in addition to the effect of the invention according to any one of the second to seventh aspects, the tool unclamp instruction means is composed of a mechanical valve switch. In addition, the switch does not malfunction due to cutting fluid or the like.

  In the machine tool of the invention according to claim 9, in addition to the effect of the invention of any one of claims 4 to 8, a wedge-shaped cam is provided at the tip of the movable shaft of the cylinder that drives the clamp opening / closing mechanism. The body is fixed with the tip facing downward, and one surface forming the wedge shape of the cam body abuts on the upper end of the swing arm, and the swing arm is rotated by the movement of the movable shaft of the cylinder. Therefore, the force generated by the cylinder can be expanded.

  Hereinafter, a machining center 1 according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a machining center 1 according to the present embodiment, FIG. 2 is a partial cross-sectional view seen from the right side surface of the machining center 1, and FIG. 3 is a direction of arrows AA shown in FIG. FIG. 4 is a partial cross-sectional perspective view of the machining center 1 as viewed from below, and FIG. 5 is a block diagram showing an electrical configuration of the machining center 1.

  First, the machining center 1 will be described. The machining center 1 shown in FIG. 1 moves a workpiece (not shown) and a tool 24 which are not shown in the drawing relative to each other to perform desired machining (for example, “boring”, “milling”, “drilling”, It is a machine tool capable of performing “cutting” and the like. The machining center 1 includes a machine main body for processing a workpiece, a bed 2 as a base of the machine main body, and a substantially rectangular parallelepiped box that is provided on the bed 2 and surrounds and protects the periphery of the machine main body. It is mainly composed of a splash cover 3 of the mold.

  Next, the splash cover 3 will be described. As shown in FIGS. 1 and 2, the splash cover 3 is formed in a substantially rectangular parallelepiped box shape, and a machining area in which workpiece machining is performed is provided inside the splash cover 3. As shown in FIGS. 2 and 4, an opening 6 having a substantially rectangular shape in front view is provided at the front center of the splash cover 3. Then, when the operator passes through the opening 6, the workpiece is attached to and detached from the table 26 disposed inside the splash cover 3. Further, as shown in FIG. 1, slide type opening and closing doors 4 and 5 that open and close the opening 6 are provided on the front surface of the splash cover 3. In addition, glass windows 4a and 5a are provided in the approximate center of the open / close doors 4 and 5, respectively, a handle 4b is provided in the vicinity of the right end of the open / close door 4, and the vicinity of the left end of the open / close door 5 is provided. Is provided with a handle portion 5b. Therefore, the opening 6 is opened by opening these handle portions 4b and 5b away from each other.

  As shown in FIGS. 1 and 4, an operation panel 10 having a substantially rectangular shape in front view for operating the machining center 1 is provided on the right side of the splash cover 3. A control device 13 shown in FIG. 5 is disposed inside the operation panel 10. As shown in FIG. 5, the control device 13 is basically composed of a CPU 13a, a ROM 13b, a RAM 13c, an input interface 15a, and an output interface 15b. As shown in FIGS. 1 and 4, on the front of the operation panel 10, an automatic operation key, an MDI operation key, a manual operation key, a code input key, a start key, a main spindle forward key, a main spindle stop key, a tool A keyboard 16 is provided as an input means having various keys such as an exchange single-action key and an outside activation key, and a CRT (display) 45 for displaying a setting screen or an execution operation is provided above the keyboard 16. .

  As shown in FIG. 5, the keyboard 16 of the operation panel 10 shown in FIG. 1 is connected to the input interface 15 a of the control device 13, and the CRT 45 is connected to the output interface 15 b of the control device 13. The NC program is input to the control device 13 based on the operation of the keyboard 16. Further, the input interface 15a includes an arm sensor 46, a Z-axis origin sensor 34, a pot raising sensor 37b, a pot lowering sensor 37a, a tool clamp sensor 66, an air cylinder sensor 67, an encoder 20a, an encoder 25a, an encoder 42a, an encoder 44a, An encoder 47a, an encoder 48a, and the like are connected. The output interface 15b includes a Z motor 20, a spindle motor 25, an X motor 47, a Y motor 48, a magazine motor 42, an air cylinder 75, a tool change motor 44, a CRT 45, a magazine shutter cylinder 64, an arm shutter cylinder 74, and the like. Is connected.

  Although not shown in the drawings, maintenance check hatches are detachably provided on the left and right side walls of the splash cover 3 shown in FIGS. The splash cover 3 having the above configuration surrounds the periphery of the machine body and protects it from the outside, and blocks the chips and cutting fluid splashes discharged from the machine body from being scattered to the outside. It prevents the external environment from being polluted.

  Next, the machine body will be described. The machine body is accommodated inside the splash cover 3. As shown in FIGS. 2, 3, and 4, the machine main body is fixed to the upper surface of the rear portion of the bed 2 and extends substantially vertically upward, and the Z-axis direction ( Mainly composed of a spindle head 22 that is movable in the vertical direction and a tool changer (ATC) that automatically changes a tool 24 mounted on the spindle head 22 to another tool 24. Yes.

  Here, the positional relationship between the individual devices in the machine body will be described in detail. As shown in FIG. 2, on the upper surface of the column 19, a Z motor 20 (see FIG. 5), which is a servo motor and is connected to the control device 13 (see FIG. 5), is mounted. Further, the Z motor 20 is provided with an encoder 20a (see FIG. 5) for detecting the rotation angle of the Z motor 20, and the encoder 20a is connected to the input interface 15a (see FIG. 5). A signal from the encoder 20a is input to the control device 13 via the input interface 15a, whereby the speed control of the Z motor 20 is performed by the control device 13. A pair of guide rails (not shown) that extend in the vertical direction and guide the spindle head 22 are fixed to the front surface of the column 19 in the vertical direction. Then, the Z motor 20 selectively rotates the feed screw (not shown) extending downward from the Z motor 20 in the forward and reverse directions, so that the spindle head 22 moves in the vertical direction. ing.

  2 and 4, a spindle 23 corresponding to a machining axis is rotatably held by a spindle holding portion 23a, and a tool 24 (see FIG. 2) is detachably mounted. The spindle 23 is rotationally driven by a spindle motor 25 (see FIG. 5), whereby the tool 24 is rotationally driven to process a workpiece fixed on the table 26. Furthermore, the spindle motor 25 is provided with an encoder 25a (see FIG. 5) for detecting the rotation angle of the spindle motor 25, and the encoder 25a is connected to the input interface 15a (see FIG. 5). A signal from the encoder 25a is input to the control device 13 via the input interface 15a, so that the speed control of the spindle motor 25 is performed by the control device 13.

  On the other hand, as shown in FIGS. 2 and 4, a table 26 is disposed below the spindle head 22. The table 26 has a work detachably fixed thereto, and is controlled to move in the X-axis direction (left-right direction) and the Y-axis direction (depth direction) by an X motor 47 and a Y motor 48 (see FIG. 5) that are servo motors. Is. A movable body 27 is provided above the bed 2, and a table 26 is disposed above the movable body 27. Further, the table 26 is guided by an X-axis guide rail (not shown) provided on the upper surface of the moving body 27, and is guided in the X-axis direction by the X motor 47. On the other hand, a pair of Y-axis guide rails (not shown) are provided on the upper portion of the bed 2, and the moving body 27 is guided in the Y-axis direction by the Y motor 48, so that the table 26 passes through the moving body 27. Guided in the Y-axis direction. Further, the X motor 47 is provided with an encoder 47a (see FIG. 5) for detecting the rotation angle of the X motor 47, and the Y motor 48 is provided with an encoder 48a (FIG. 5) for detecting the rotation angle of the Y motor 48. The encoder 47a and the encoder 48a are respectively connected to the input interface 15a (see FIG. 5). Each signal from the encoder 47a and the encoder 48a is input to the control device 13 via the input interface 15a, so that the speed control of the X motor 47 and the Y motor 48 is performed by the control device 13. The Y-axis guide rail is provided with telescopic covers 28 and 28 for preventing chips from accumulating on the rail so as to sandwich the table 26 in the center. Further, a telescopic cover 29a and a protective cover 29b are provided on the X-axis guide rail so as to sandwich the moving body 27.

  Next, the tool changer will be described. This tool changer automatically changes the tool 24 of the main shaft 23 with another tool 24. As shown in FIGS. 2 and 4, the tool changer is mainly composed of a tool magazine 30 storing a plurality of tools 24 and a tool change arm 39 for exchanging the tools 24 of the main shaft 23. . The tool change arm 39 is driven by a tool change motor 44, and the tool change motor 44 is provided with an encoder 44a (see FIG. 5) for detecting the rotation angle of the tool change motor 44.

  First, the tool magazine 30 will be described. As shown in FIG. 2, the tool magazine 30 is fixed to the column 19 and has a substantially elliptical shape in a side view. A tool path 30a having a substantially elliptical shape when viewed from the front is formed inside the tool magazine 30, and a plurality of tool pots 31 are accommodated in the tool path 30a. Further, a tool 24 is detachably stored inside each tool pot 31. The position of the tool 24 stored in each tool pot 31 stored in the tool passage 30a shown in FIG. 2 corresponds to the “tool storage position”.

  As shown in FIG. 2, a tool changer 30 b that opens downward is provided on the lower front side of the tool magazine 30. The plurality of tool pots 31 move in the tool passage 30a by driving a magazine motor 42 (see FIG. 5). Further, the magazine motor 42 is provided with an encoder 42a (see FIG. 5) for detecting the rotation angle of the magazine motor 42. The encoder 42a is connected to the input interface 15a (see FIG. 5). A signal from the encoder 42a is input to the control device 13 via the input interface 15a, whereby the speed control of the magazine motor 42 is performed by the control device 13. The plurality of tool pots 31 are provided with a pot identification plate 33 (see FIG. 5) that moves integrally with the tool pot 31. The pot identifying plate 33 is formed with a light transmitting portion (not shown) having a different pattern for each tool pot 31 so that each tool pot 31 can be individually identified.

  Further, the tool magazine 30 is provided with an identification sensor 35 for individually identifying the tool pots 31. As shown in FIG. 5, the identification sensor 35 includes a light projecting element 35 a and a light receiving element 35 b, which are arranged to face each other with the pot identification plate 33 interposed therebetween. And the control apparatus 13 detects which tool pot 31 was conveyed to the tool exchange part 30b of the tool magazine 30 based on the signal from the light receiving element 35b. When it is detected that the magazine has been transported, the magazine motor 42 is stopped to position the predetermined tool 24 in the tool changer 30b.

  As shown in FIGS. 2, 3, and 4, the tool magazine 30 is provided with a substantially rectangular parallelepiped box-shaped magazine cover 60 for surrounding and protecting the tool magazine 30, and the inner wall surface of the splash cover 3. It is fixed to. The magazine cover 60 is made of an iron plate, and is intended to prevent chips and cutting fluid scattered from the processing area from adhering to and accumulating in the tool magazine 30. Further, as shown in FIG. 3, in the magazine cover 60, the opening facing the tool changer 30b of the tool magazine 30 shown in FIG. 2 and opened stepwise toward the tool changer arm 39 side. 61 is provided. The opening 61 is provided with a stepped magazine shutter 62 that slides to open and close the opening 61. When the predetermined tool pot 31 is rotated downward by the pot lowering mechanism of the tool magazine 30 and the predetermined tool 24 protrudes downward through the tool changer 30b, the magazine shutter 62 is opened and the opening 61 is opened. Is done. Thereby, the tool 24 protruding from the tool changer 30 b protrudes downward from the opening 61. The magazine shutter 62 is opened by moving from the front surface side of the splash cover 3 toward the column 19 side, and closed by moving in the opposite direction.

  Next, the structure around the spindle head 22 will be described with reference to FIGS. 6 and 7 are perspective views of the vicinity of the spindle head 22 and the tool magazine 30, FIG. 8 is a front view of the tool magazine 30, and FIG. 9 is a plan view of the vicinity of the spindle head 22 and the tool magazine 30. 10 is a left side view of the vicinity of the spindle head 22 and the tool magazine 30, and FIGS. 11 and 13 are arrows of parts other than the air cylinder 75 and the spindle motor 25 along the line BB in FIG. FIG. 12 and FIG. 14 are partial cross-sectional views in the direction of the arrows of the part other than the spindle motor 25 taken along the line BB in FIG. 6, and FIG. It is a fragmentary sectional view.

  As shown in FIG. 6 to FIG. 10, the side surface of the spindle head 22 is covered with a side cover 22a, and a spindle motor 25 that rotationally drives the spindle 23 is provided on the upper part of the spindle head 22. An air cylinder 75 for operating an unclamping mechanism, which will be described later, is provided on the housing 76 in the vicinity of the spindle motor 25 above the spindle head 22. The spindle 23 is held by a spindle holder 23 a, and a tool change arm drive 77 including a tool change arm 39 is provided between the spindle head 22 and the tool magazine 30. Further, a mechanical valve switch 78 is provided below the side cover 22a of the spindle head 22. When the mechanical valve switch 78 is pressed (turned on), the air cylinder 75 is driven to lower the cylinder shaft 75a (see FIG. 14), and when released (turned off), the cylinder shaft 75a of the air cylinder 75 is driven. Rises and returns to the original position (see FIG. 12). The mechanical valve switch 78 is a mechanical switch having a structure that blocks the passage in the compressed air space. The mechanical valve switch 78 always blocks the passage in the compressed air space, and when pressed (turned on), the passage in the compressed air space is connected to air. When the cylinder 75 is driven and released (turned off), the passage of the compressed air space is closed and the driving of the air cylinder 75 is released. The mechanical valve switch 78 corresponds to “tool unclamp instruction means”. Since the mechanical valve switch 78 is provided in the vicinity of the main shaft 23, it is easy to give an instruction to unclamp the tool 24 during maintenance.

  Next, details of the structure of the spindle head 22 will be described with reference to FIGS. 11 to 14. As shown in FIGS. 11 to 14, a spindle motor 25 for rotating the spindle 23 is fixed on the upper surface of the spindle head 22 with the motor shaft 25b facing downward, and a coupling 79 is fixed to the motor shaft 25b. The main shaft 23 is fixed to the lower part of the coupling 79. An unclamp ring 80 is provided on the outer periphery of the intermediate portion of the main shaft 23.

  A cam follower (not shown) formed in a substantially L-shape, which will be described later, and provided at the distal end portion 81b of the short arm portion 81a of the swing arm 81 is brought into contact with the unclamp ring 80 and can be pushed down. A spindle 82 is provided at the tip of the main shaft 23. Furthermore, a draw bar 83 that can move up and down along the axis of the main shaft is provided inside the main shaft 23, and a collet 84 is connected to the tip of the draw bar 83. Further, a plug 85 is fixed to the upper end portion of the draw bar 83, and a string spring 86 for urging the plug 85 upward is provided in a space between the plug 85 and the collet 84. The plug 85 and the unclamp ring 80 are connected by a pin 87. When the unclamp ring 80 is pushed down by the cam follower at the tip 81b of the short arm 81a of the swing arm 81, the plug 85 is pushed down. The draw bar 83 is lowered and the collet 84 is lowered so that the tool 24 is released. These configurations correspond to a “clamp opening / closing mechanism”.

  Next, the structure of the swing arm 81 and its drive mechanism will be described. As shown in FIGS. 11 to 14, the swing arm 81 is a metal member provided in the spindle head 22 and formed in a substantially L shape, and includes a short arm portion 81 a and a long arm portion 81 d. The bent portion 81 c is pivotally supported by a support portion 89 in the spindle head 22 by a shaft 88. Further, a roller-shaped cam follower 81f is rotatably provided at the distal end portion 81e of the long arm portion 81d. Further, an air cylinder 75 is provided in the housing 76 provided on the upper part of the spindle head 22, and as shown in FIGS. 12 and 14, the air cylinder 75 is provided with a cylinder shaft 75a that moves up and down. A coupling 75b is connected to the tip of the cylinder shaft 75a, a cylindrical cam shaft 90 is fixed to the lower side of the coupling 75b, and a wedge-shaped cam body is attached to the lower end of the cam shaft 90. 91 is fixed. The cam body 91 is fixed with a pointed portion facing downward. The slope of the cam body 91 is in contact with the cam follower 81f.

  Accordingly, when the air cylinder 75 is driven, the cylinder shaft 75a is lowered, the cam body 91 fixed to the cam shaft 90 is lowered, and the cam follower 81f provided rotatably at the distal end portion of the long arm portion 81d. Is pushed in the direction of the spindle motor 25. Then, the swing arm 81 is rotated clockwise, the short arm portion 81a of the swing arm 81 pushes down the unclamp ring 80, and the unclamp ring 80 is pushed down by the cam follower of the tip portion 81b of the short arm portion 81a of the swing arm 81. Then, the plug 85 is pushed down, the draw bar 8 is lowered, the collet 84 is lowered, and the tool 24 is released. In the present embodiment, since the long arm portion 81d of the swing arm 81 is rotationally driven using the wedge-shaped cam body 91, the swing arm 81 that pushes down the unclamp ring 80 against the push-down force of the air cylinder 75. The force generated in the cam follower at the tip 81b of the short arm 81a is about twice.

  Hereinafter, an error check process 1 and an error check process 2 for preventing the main shaft 23 from rotating in an unclamped state according to the first embodiment of the present invention will be described with reference to FIGS. 17 and 18. FIG. 17 is a flowchart of error check processing 1 using an input from a tool clamp sensor 66 (sensor 1) for preventing the spindle 23 from rotating in an unclamped state, and FIG. It is a flowchart of the error check process 2 using the input from the air cylinder sensor 67 (sensor 2) for preventing rotating in an unclamped state.

  The error check process 1 and the error check process 2 are based on the detection result of the tool clamp sensor 66 (sensor 1) or the air cylinder sensor 67 (sensor 2), the main spindle normal rotation key, the main spindle stop key, the tool change single action key, This is a process for preventing the main shaft 23 from rotating in an unclamped state triggered by pressing of the start key, the outer start key, or the like. That is, when the main shaft 23 is rotated from now on, the main shaft 23 in the unclamped state of the tool is prevented from rotating. Note that the error check processing 1 and error check processing 2 programs are executed in parallel by the CPU 13a of the control device 13 shown in FIG. This is because the machining center 1 according to the first embodiment is a machine tool, so that accident prevention is doubled. As shown in FIG. 16, the tool clamp sensor 66 is provided on the side surface of the main shaft holding portion 23 a of the main shaft 23, and can detect the vertical position of the unclamp ring 80 by an internal sensor. The air cylinder sensor 67 is provided on the side surface of the air cylinder 75 so that the state of the air cylinder 75 can be detected. The tool clamp sensor 66 and the air cylinder sensor 67 correspond to “clamp state detection means”.

  Next, error check processing 1 will be described with reference to FIG. First, an operation check by the error check process 1 is started (S1). Next, it is determined whether or not the spindle unclamping mechanism is “valid” (S2). This is because the spindle unclamping mechanism is an optional function, so there are some that do not have a spindle unclamping mechanism. Therefore, if the spindle unclamping mechanism is provided, the spindle unclamping mechanism is judged to be “effective”. If the spindle unclamp mechanism is not provided (S2: YES), it is determined that the spindle unclamp mechanism is not effective (S2: NO). Specifically, this determination is made by the CPU 13a checking the spindle unclamping mechanism valid flag stored in the RAM 13c. If the spindle unclamping mechanism is provided, the spindle unclamping mechanism effective flag is ON. If the spindle unclamping mechanism is not provided, the spindle unclamping mechanism effective flag is OFF.

  If it is determined that the spindle unclamping mechanism is valid (S2: YES), it is next determined whether or not the startup mode of the machining center 1 is the normal mode (S3). The normal mode is a mode for machining a workpiece, and there are other modes such as a mode for recovering when the position of the automatic tool changer of the machining center 1 is incorrect. In the normal mode (S3: YES), it is determined whether or not the tool 24 is unclamped (S4). This determination is made based on an input from the tool clamp sensor 66. The tool clamp sensor 66 is disposed in the vicinity of the unclamp ring 80 and is detected in the vicinity of a place where the tool 24 is actually clamped and unclamped. In the unclamped state, the output of the tool clamp sensor 66 is ON, and in the clamped state, the output of the tool clamp sensor 66 is OFF.

  When the tool is unclamped (when the tool clamp sensor is ON) (S4: YES), that is, the unclamp ring 80 is pushed down by the cam follower of the distal end portion 81b of the short arm portion 81a of the swing arm 81, and the draw bar 8 is lowered. When 84 is lowered and the tool 24 is released, it is determined whether or not the current operation mode is the “manual” mode (S5). When the operation mode is the manual mode (S5: YES), when the spindle forward rotation key is pressed (S6: YES), “Spindle tool unclamp (sensor 1)” is displayed and an alarm is generated and specified. The performed operation (in this case, the rotation operation of the spindle) is not performed (S13). The CPU 13a that performs the process of S13 corresponds to "alarm means" and "spindle rotation prohibiting means".

  In addition, when the operation mode is the manual mode (S5: YES), when the main spindle forward rotation key is not pressed (S6: NO) and the main spindle stop key is pressed (S7: YES), “spindle tool unclamp ( “Sensor 1)” is displayed and an alarm is generated, and the designated operation is not performed (in this case, the spindle is stopped because it is stopped) (S13).

  Also, when the operation mode is the manual mode (S5: YES), the spindle forward rotation key is not pressed (S6: NO), the spindle stop key is not pressed (S7: NO), and the tool change single action key is pressed In addition, (S8: YES), “spindle tool unclamp (sensor 1)” is displayed and an alarm is generated, and the designated operation is not performed (in this case, the single action for tool change is not performed). (S13).

  Further, when the operation mode is not the manual mode (S5: NO), the program edit mode ring member is not located (S9: YES), and the start key is pressed (S10: YES), “spindle tool” "Unclamp (sensor 1)" is displayed and an alarm is generated, and the designated operation is not performed (in this case, the spindle 23 is not activated) (S13).

  Further, when the operation mode is not the manual mode (S5: NO), and the program edit mode ring member is not located (S9: YES), the start key is not pressed (S10: NO), and the operation mode is the memory operation mode. In this case (S11: YES), it is determined whether or not the outer activation key is pressed (S12). When the outer activation key is pressed, the outer work on the pallet is taken in and the spindle 23 is activated. When the outer activation key is pressed (S12: YES), “Spindle tool unclamp (sensor 1)” is displayed and an alarm is generated, and the specified operation is not performed (in this case, the pallet is not opened). It does not move and the spindle 23 is not activated) (S13). If “NO” is determined in S2, S3, S4, S9, S11, and S12, the process returns to S22.

  Next, the error check process 2 will be described with reference to FIG. First, an operation check by the error check process 2 is started (S21). Next, it is determined whether or not the spindle unclamping mechanism is “valid” (S22). If it is determined that the spindle unclamping mechanism is valid (S22: YES), it is next determined whether or not the startup mode of the machining center 1 is the normal mode (S23). In the normal mode (S23: YES), next, the tool 24 determines whether or not it is unclamped (S24). This determination is made based on a signal from an air cylinder sensor 67 provided in the air cylinder 75. That is, the air cylinder sensor 67 is turned off when the cylinder shaft 75a of the air cylinder 75 is lowered, and the air cylinder sensor 67 is turned on when the cylinder shaft 75a of the air cylinder 75 is raised.

  When the tool is unclamped (when the air cylinder sensor is OFF) (S24: YES), that is, the unclamp ring 80 is pushed down by the cam follower of the tip 81b of the short arm 81a of the swing arm 81, and the draw bar 8 is lowered. When the collet 84 is lowered and the tool 24 is released, it is determined whether or not the current operation mode is the “manual” mode (S25). When the operation mode is the manual mode (S25: YES), when the spindle forward rotation key is pressed (S26: YES), “Spindle tool unclamp (sensor 2)” is displayed and an alarm is generated and specified. The performed operation (in this case, the rotation operation of the spindle) is not performed (S33). The CPU 13a that performs the process of S33 corresponds to "alarm means" and "spindle rotation prohibiting means".

  In addition, when the operation mode is the manual mode (S25: YES), when the main spindle forward rotation key is not pressed (S26: NO) and the main spindle stop key is pressed (S27: YES), “spindle tool unclamp ( "Sensor 2)" is displayed and an alarm is generated, and the designated operation is not performed (in this case, the spindle is stopped because it is stopped) (S33).

  In addition, when the operation mode is the manual mode (S25: YES), the spindle forward rotation key is not pressed (S26: NO), the spindle stop key is not pressed (S27: NO), and the tool change single action key is pressed. In addition (S28: YES), “spindle tool unclamp (sensor 2)” is displayed and an alarm is generated, and the designated operation is not performed (in this case, the single action for tool change is not performed). (S33).

  In addition, when the operation mode is not the manual mode (S25: NO), the program editing mode ring member is not located (S29: YES), and the start key is pressed (S30: YES), “spindle tool” "Unclamp (sensor 2)" is displayed and an alarm is generated, and the designated operation is not performed (in this case, the spindle 23 is not activated) (S33).

  Further, when the operation mode is not the manual mode (S25: NO), and the program edit mode ring member is not located (S29: YES), the start key is not pressed (S30: NO), and the operation mode is the memory operation mode. In this case (S31: YES), it is determined whether or not the outside activation key has been pressed (S32). When the outer activation key is pressed, the outer work on the pallet is taken in and the spindle 23 is activated. When the outer activation key is pressed (S32: YES), “Spindle tool unclamp (sensor 2)” is displayed and an alarm is generated, and the designated operation is not performed (in this case, the pallet is not opened). It does not move and the spindle 23 is not activated) (S33). If “NO” is determined in S22, S23, S24, S29, S31, and S32, the process returns to S22.

  As described above, in the first embodiment of the present invention, an error is generated to prevent the spindle 23 from being rotated in an unclamped state by using a sensor signal from the tool clamp sensor 66 (sensor 1). Since the check process 1 and the error check process 2 are simultaneously performed in parallel to prevent the main shaft 23 from rotating in an unclamped state using the sensor signal from the air cylinder sensor 67 (sensor 2), the main shaft It can prevent that 23 rotates in an unclamped state, and can prevent that the main axis | shaft 23 is damaged. In addition, since monitoring using the tool clamp sensor 66 and monitoring using the air cylinder sensor 67 are performed in parallel, it is possible to monitor twice and prevent the spindle 23 from being damaged even if one of the sensors fails. it can.

  Next, an error check process 3 and an error check process 4 for preventing the main shaft 23 from rotating in an unclamped state according to a second embodiment of the present invention will be described with reference to FIGS. 19 and 20. . The error check process 3 and the error check process 4 are constantly monitored to prevent the main shaft 23 from rotating in an unclamped state. That is, the error check process 3 and the error check process 4 are to immediately stop the rotation of the main shaft 23 when the main shaft 23 is in an unclamped state.

  Here, FIG. 19 is a flowchart of the error check process 3 of the constant monitoring using the input from the tool clamp sensor 66 (sensor 1) for preventing the main shaft 23 from rotating in the unclamped state. 20 is a flowchart of the error check process 2 for continuous monitoring using the input from the air cylinder sensor 67 (sensor 2) for preventing the main shaft 23 from rotating in an unclamped state. The error check processing 3 and error check processing 4 programs are executed in parallel by the CPU 13a of the control device 13 shown in FIG. This is for the purpose of preventing accidents in the same way as in the first embodiment.

  First, the error check process 3 will be described with reference to FIG. First, an operation check for constant monitoring by the error check process 3 is started (S41). Next, it is determined whether or not the spindle unclamping mechanism is “valid” (S42). If it is determined that the spindle unclamping mechanism is valid (S42: YES), it is next determined whether or not the startup mode of the machining center 1 is a normal mode (a mode for machining a workpiece) (S43). In the normal mode (S43: YES), next, the tool 24 determines whether or not it is unclamped (S44). This determination is made based on a signal from the tool clamp sensor 66.

  When the tool is unclamped (when the tool clamp sensor 66 is ON) (S44: YES), that is, the unclamp ring 80 is pushed down by the cam follower of the distal end portion 81b of the short arm portion 81a of the swing arm 81, and the draw bar 8 is When the lower collet 84 is lowered and the tool 24 is released (S44: YES), if the spindle 23 is rotating (S45: YES), “Spindle tool unclamp (sensor 1)” is displayed. Alarm is generated and the rotation operation of the spindle is immediately stopped (S46). The CPU 13a that performs the process of S46 corresponds to "alarm means" and "spindle rotation prohibiting means". If “NO” is determined in the determinations of S42, S43, S44, and S45, the process returns to S42.

  Next, the error check process 4 will be described with reference to FIG. First, an operation check for constant monitoring by the error check process 4 is started (S51). Next, it is determined whether or not the spindle unclamping mechanism is “valid” (S52). If it is determined that the spindle unclamping mechanism is valid (S52: YES), it is next determined whether or not the startup mode of the machining center 1 is a normal mode (a mode for machining a workpiece) (S53). In the normal mode (S53: YES), next, the tool 24 determines whether or not it is unclamped (S54). This determination is made based on a signal from the air cylinder sensor 67. That is, the air cylinder sensor 67 is turned off when the cylinder shaft 75a of the air cylinder 75 is lowered, and the air cylinder sensor 67 is turned on when the cylinder shaft 75a of the air cylinder 75 is raised.

  When the tool is unclamped (when the air cylinder sensor is OFF) (S54: YES), that is, the unclamp ring 80 is pushed down by the cam follower of the tip 81b of the short arm 81a of the swing arm 81, and the draw bar 8 is lowered. When the collet 84 is lowered and the tool 24 is released (S54: YES), if the spindle 23 is rotating (S55: YES), “Spindle tool unclamp (sensor 2)” is displayed. An alarm is generated and the rotation operation of the spindle is immediately stopped (S56). The CPU 13a that performs the process of S56 corresponds to "alarm means" and "spindle rotation prohibiting means". If “NO” is determined in the determinations of S52, S53, S54, and S55, the process returns to S42.

  As described above, in the second embodiment of the present invention, the spindle 23 is prevented from continuing to rotate in an unclamped state by constantly monitoring using the sensor signal from the tool clamp sensor 66 (sensor 1). The error check process 3 to be performed and the error check process 4 to prevent the main shaft 23 from continuing to rotate in an unclamped state by continuous monitoring using the sensor signal from the air cylinder sensor 67 (sensor 2) simultaneously in parallel. Therefore, when the main shaft 23 is rotated in an unclamped state, the rotation can be stopped immediately and the main shaft 23 can be prevented from being damaged. In addition, since the constant monitoring using the tool clamp sensor 66 and the constant monitoring using the air cylinder sensor 67 are performed in parallel, the monitoring can be performed twice, and the spindle 23 is damaged even if one of the sensors fails. Can be prevented.

  The present invention is not limited to the above embodiments, and various modifications can be made. For example, instead of pushing the distal end portion 81e of the long arm portion 81d of the swing arm 81 using the air cylinder 75 and the cam body, as shown in the partial cross-sectional view of the modification shown in FIG. Is provided on the spindle head 22, and the operator presses the pressing portion 95a of the hand pressing mechanism 95 with the hand so that the tip end portion 95b of the hand pressing mechanism 95 presses the tip end portion 81e of the long arm portion 81d of the swing arm 81. Also good. Further, the alarm may be not only a character display but also a warning by voice or a buzzer.

  The machine tool of the present invention can be applied not only to a vertical machining center but also to a horizontal machining center.

It is a front view of the machining center 1 which is this embodiment. FIG. 2 is a partial cross-sectional view seen from the right side of the machining center 1. It is AA arrow direction sectional drawing shown in FIG. It is the fragmentary sectional perspective view which looked at the machining center 1 from the downward direction. 2 is a block diagram showing an electrical configuration of the machining center 1. FIG. 2 is a perspective view of the vicinity of a spindle head 22 and a tool magazine 30. FIG. 2 is a perspective view of the vicinity of a spindle head 22 and a tool magazine 30. FIG. 2 is a front view of a tool magazine 30. FIG. 2 is a plan view of the vicinity of a spindle head 22 and a tool magazine 30. FIG. 2 is a left side view of the vicinity of a spindle head 22 and a tool magazine 30. FIG. FIG. 7 is a partial cross-sectional view in the arrow direction of a portion other than the air cylinder 75 and the main shaft motor 25 taken along line BB in FIG. 6. It is a fragmentary sectional view of the arrow directions of parts other than the spindle motor 25 in the BB line of FIG. FIG. 7 is a partial cross-sectional view in the arrow direction of a portion other than the air cylinder 75 and the main shaft motor 25 taken along line BB in FIG. 6. It is a fragmentary sectional view of the arrow directions of parts other than the spindle motor 25 in the BB line of FIG. It is a fragmentary sectional view of a modification. 3 is a perspective view of the spindle head 22 showing the positions of a tool clamp sensor 66 and an air cylinder sensor 67. FIG. It is a flowchart of the error check process 1 using the input from the tool clamp sensor 66 (sensor 1) for preventing the main shaft 23 from rotating in an unclamped state. It is a flowchart of the error check process 2 using the input from the air cylinder sensor 67 (sensor 2) for preventing the main shaft 23 from rotating in an unclamped state. It is a flowchart of the error check process 3 of the constant monitoring using the input from the tool clamp sensor 66 (sensor 1) for preventing the main shaft 23 from rotating in an unclamped state. It is a flowchart of the error check process 2 of the constant monitoring using the input from the air cylinder sensor 67 (sensor 2) for preventing the main shaft 23 from rotating in an unclamped state.

Explanation of symbols

1 Machining Center 2 Bed 10 Operation Panel 13 Control Device 13a CPU
16 Keyboard 19 Column 22 Spindle head 23 Spindle 24 Tool 30 Tool magazine 66 Tool clamp sensor 67 Air cylinder sensor 75 Air cylinder 75a Cylinder shaft 76 Housing 78 Mechanical valve switch 80 Unclamp ring 81 Swing arm 81a Short arm part 81b Tip part 81d Long Arm part 81e Tip part 81f Cam follower 91 Cam body

Claims (9)

A spindle with a tool clamp that holds various tools detachably,
A clamp opening and closing mechanism for opening and closing the tool clamp;
A spindle motor that rotationally drives the spindle;
A spindle head for holding the spindle motor;
A tool magazine containing multiple tools,
In a machine tool comprising a tool changer for exchanging a tool held in the tool clamp and a tool stored in the tool magazine,
Clamp state detection means for detecting whether the tool clamp is in an unclamped state where no tool is held;
A machine tool comprising: a spindle rotation prohibiting unit that does not rotate the spindle by the spindle motor when the clamp state detecting unit detects that the tool clamp is in an unclamped state. Tool unclamp instruction means for instructing the clamp opening and closing mechanism to place the tool clamp in an unclamped state;
In a state in which the tool clamp is instructed to put the tool clamp in an unclamped state by the tool unclamp instruction means, the clamp opening / closing mechanism puts the tool clamp in an unclamped state,
The clamp opening and closing mechanism sets the tool clamp to a clamp state for holding a tool when the tool unclamp instruction means is not instructed to put the tool clamp into an unclamp state. The machine tool according to 1.   When the tool unclamp instruction means instructs the tool clamp to be in an unclamped state, an alarm is issued when the clamp state detection means detects that the tool clamp is in an unclamped state. The machine tool according to claim 1, further comprising an alarm means for generating the alarm. The clamp opening and closing mechanism is
A cylinder whose movable shaft can be retracted;
A swing arm which is formed in a substantially L shape, a bent portion is pivotally supported, and one end thereof is rotated by a drive shaft of the cylinder;
A ring member provided on the main shaft and pressed down by one end of the swing arm abutting,
The work according to any one of claims 1 to 3, wherein the clamp state detection means detects whether or not the tool clamp is in an unclamped state in which no tool is held based on the position of the ring member. machine. The clamp opening and closing mechanism is
A cylinder whose movable shaft can be retracted;
A swing arm which is formed in a substantially L shape, a bent portion is pivotally supported, and one end thereof is rotated by a drive shaft of the cylinder;
A ring member provided on the main shaft and pressed down by the other end of the swing arm abutting,
The machine tool according to any one of claims 1 to 3, wherein the clamp state detecting means detects whether or not the tool clamp is in an unclamped state in which no tool is held according to a state of the cylinder. .   6. The machine tool according to claim 2, wherein the tool unclamp instruction means is provided in the vicinity of the main shaft.   7. The machine tool according to claim 2, wherein the tool unclamp instruction means is provided on the spindle head.   The machine tool according to any one of claims 2 to 7, wherein the tool unclamp instruction means comprises a mechanical valve switch. A wedge-shaped cam body is fixed to the tip of the movable shaft of the cylinder with the tip facing downward, and one surface forming the wedge-shaped shape of the cam body abuts on the upper end of the swing arm. The machine tool according to any one of claims 4 to 8, wherein the swing arm is rotated by moving the movable shaft of the cylinder.

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