JP4629392B2 - Protective cover opening / closing device for machine tools - Google Patents

Description

  The present invention relates to a protective cover for a machine tool, and more particularly to a protective cover opening / closing device that automatically opens and closes the protective cover.

  Machine tools such as lathes and machining centers are equipped with protective covers for the purpose of deteriorating the working environment due to chips generated during machining, scattering of cutting fluid used for cooling and lubrication during machining, or ensuring the safety of workers. It is common to install. These protective covers include a partial cover and an overall cover that covers the entire machine. However, any of these protective covers may interfere with work when an operator removes a workpiece, tool, or jig. The door provided in the part which notched the cover itself or a part of the whole cover was moved or detached manually.

  In recent years, machine tools have also become numerically controlled machine tools, and automatic machining by machining programs has become commonplace. For the purpose of further automation and labor saving, it is possible to automatically exchange workpieces using robots and loaders. There are many. In such a case, the protective cover is also automatically moved, and in many cases, the cover opening / closing device is driven using a fluid pressure cylinder by a fluid such as hydraulic pressure or pneumatic pressure.

  FIG. 8 shows an example of a conventional machine tool with a cover opening and closing device. Here, as an example of a protective cover that is opened and closed, a door provided by cutting out a part of the entire cover fixed to the machine tool is shown. ing. The machine tool 1 is covered with an entire cover 2 fixed to the entire outer periphery thereof, and the entire cover 2 is partially cut away and a door 3 is provided at that portion. A fluid pressure cylinder 24 is fixed to the upper part of the entire cover 2, and the tip of the piston rod of the fluid pressure cylinder 24 is attached to the cover 3. The fluid pressure cylinder is driven by fluid supplied from a hydraulic pressure or pneumatic pressure source (not shown). As a result, the door 3 is in a closed position indicated by a solid line in FIG. 8 and an open position indicated by a two-dot chain line (or indicated by a solid line in FIG. 9). (Open position).

  The machine tool 1 is shown here as an example of a numerically controlled lathe. A spindle (not shown) is rotatably supported by the machine tool 1, and a chuck 9 for gripping a workpiece W is provided at the tip of the spindle. It can rotate integrally with the main shaft.

  Further, a loader beam 10 is installed with legs at both ends above the machine tool 1 in a horizontal direction parallel to the rotation axis of the chuck 9, and a loader arm 11 is parallel to the rotation axis of the chuck 9 on the loader beam 10. It is provided to be movable in a horizontal direction perpendicular to the horizontal direction. At the lower end of the loader arm 11, chucks 12a and 12b capable of gripping the workpiece W are attached. The movement of the loader arm 11 in the horizontal and vertical directions and the opening and closing of the chucks 12a and 12b are controlled by a numerical control device (not shown) as in a general numerical control machine tool.

  The operation of the conventional cover opening / closing device configured as described above will be described. At the time of machining in the machine tool 1, the workpiece W is attached to the chuck 9 with a tool post (not shown) while the door 3 is in the closed position as shown by a solid line in FIG. Is processed. During processing, the loader arm 11 holds the workpiece to be processed next on the chuck 12b and stands by on the machine tool.

  When the machining is finished and the rotation of the spindle (not shown) and the chuck 9 and the workpiece W attached thereto is stopped, fluid is supplied from a hydraulic or pneumatic source (not shown) to the fluid pressure cylinder 24, and the door 3 is shown in FIG. The position is moved from the fully closed position indicated by the solid line to the fully open position indicated by the two-dot chain line (or the fully open position indicated by the solid line in FIG. 9). This fully open position is a maximum position predetermined by a stroke of the fluid pressure cylinder or a limit switch (not shown).

  By the way, the opening width of the door 3 required for the workpiece exchanging operation by the loader shown in the figure is as follows. The workpiece W held by the chuck 9 of the machine tool 1 and the loader arm 11 are shown in FIG. It is sufficient that the loader arm 11 has a width that can be lowered into the entire cover 2 of the machine tool 1 without interference with the workpiece W held by the chuck 12b. Therefore, the workpiece W to be processed changes in accordance with the length of the chuck 9 in the rotation axis direction. However, as described above, the opening width of the door is the maximum position determined in advance by the stroke of the fluid pressure cylinder or a limit switch (not shown). In FIG. There is an unnecessarily large space between them.

  After the door 3 is moved to the open position and stopped, the processed workpiece W held by the chuck 9 is transferred to the chuck 12a of the loader arm 11 by moving the loader arm horizontally and vertically and opening and closing the chucks 9, 12a and 12b. Next, the unprocessed workpiece W held on the chuck 12 b of the loader arm 11 is transferred to the chuck 9. Thereafter, when the loader arm rises above the entire cover 2, fluid is supplied from a hydraulic or pneumatic pressure source (not shown) to the fluid pressure cylinder 24, and the door 3 moves from the fully open position to the fully closed position and is attached to the chuck 9. Start machining of the workpiece W.

  Incidentally, the applicant has devised Patent Document 1 regarding such a door opening and closing device using a fluid pressure cylinder.

Actual Kaihei 6-17843

  Here, in the conventional protective cover opening / closing device of the machine tool, the opening width provided in the entire cover 2 by moving the door 3 to the open position is changed by the operator with the size of the workpiece to be processed, the chuck 9 and the tool. In consideration of the space that facilitates the work, the maximum required amount is obtained, and the fully open position of the door 3 is determined using this maximum amount as the opening width, and this is used as the operation stroke of the fluid pressure cylinder. Therefore, when the door 3 is automatically operated using the fluid pressure cylinder 24, the door can be stopped only at the fully open position or the fully closed position. For this reason, depending on the actual work, it may be opened to an unnecessary width, in which case the time required for opening and closing becomes longer, the non-processing time becomes longer, and consequently the cycle time becomes longer. Had the problem.

  The present invention has been made in order to solve the above-mentioned problems of the protective cover opening and closing device of a conventional machine tool, and the object of the present invention is to provide an arbitrary protective cover between the fully open position and the fully closed position. It is an object of the present invention to provide a protective cover opening / closing device for a machine tool that can shorten the non-machining time by shortening the opening / closing time of the protective cover so that it can be moved to an intermediate position, thereby reducing the cycle time.

In order to solve the above problems, the protective cover opening / closing device according to claim 1 of the present invention is provided in a numerically controlled machine tool for machining a workpiece based on a machining program, and is movably attached on the machine tool body. a protective cover, the protective cover opening and closing means for opening and closing the protective cover, met protection cover opening and closing device for a machine tool having a protective cover control means for controlling said protective cover opening and closing means based on a preset protective cover stop position, the And
The protective cover stop position is set to a fully closed position and a predetermined intermediate position between the fully closed position and the fully open position, and the protective cover control means stores the protective cover stop position. A storage means, a door opening / closing processing section for reading a protective cover stop position stored in the protective cover stop position storage means based on a door opening / closing command in the machining program and outputting a door drive command, and an output from the door opening / closing processing section A door opening / closing drive control unit for driving the protection cover opening / closing means based on the door drive command, and the protection cover stop position is stored from the protection cover stop position storage means based on the door opening / closing command of the machining program. The protective cover is read and opened / closed to the protective cover stop position .

  In the protective cover opening and closing device according to claim 2 of the present invention, the protective cover opening and closing means comprises a servo motor and a ball screw.

According to the protective cover opening and closing device of the first aspect of the present invention, the protective cover is stopped at an arbitrary intermediate position between the fully closed position and the fully open position by setting the stop position of the protective cover in advance. Can do. Therefore, since the door can be opened and stopped only for the opening width necessary for the work performed by opening the protective cover, the opening and closing time of the door can be shortened. By shortening the opening and closing time of the door, the non-machining time of the machine tool can be shortened, and the cycle time of machining the workpiece can be shortened, so that the productivity by the machine tool can be improved.
Furthermore, since a protective cover stop position storage means for storing the protective cover stop position is provided, it is easy to change the protective cover stop position, and by describing a protective cover stop position read command in the machining program, An arbitrary stop position can be easily selected from a plurality of pre-stored protective cover stop positions, and a stop position corresponding to the machining program can be automatically read.

  According to the protective cover opening and closing device of the second aspect of the present invention, the protective cover is opened and closed by using the servo motor and the ball screw, so that it can be used in the same manner as an existing numerical control machine tool. Therefore, it is possible to describe an intermediate position for stopping the door in the machining program.

  In addition, not only the position but also the speed and acceleration can be controlled by the servo motor and ball screw, so it is possible to reduce the impact at the time of stopping the door by reducing the speed just before the stop position, It is also possible to suppress generation of vibration and noise.

  Hereinafter, a cover opening and closing device for a machine tool according to the present invention will be described with reference to the drawings. FIG. 1 is a front view showing a machine tool with a cover opening / closing device according to the present invention in a state where a protective cover that can be opened / closed is closed, and FIG. 2 is a machine tool with a cover opening / closing device according to the present invention that can be opened / closed. FIG. 3 shows a control circuit of the protective cover opening / closing device of the present invention.

  FIG. 1 shows an example of a machine tool with a cover opening and closing device according to the present invention. Here, as an example of a protective cover to be opened and closed, a door provided by cutting out a part of the entire cover fixed to the machine tool. Is shown. The machine tool 1 is covered with an entire cover 2 fixed to the entire outer periphery thereof, and the entire cover 2 is partially cut away and a door 3 is provided at that portion. The door 3 functions as a protective cover when it is in a position to close the notch portion of the entire cover 2.

  A servo motor 4 is fixed to the upper part of the whole cover 2. In addition, as long as the servo motor is fixed to the machine tool, there is no problem even if it is attached to either the machine tool 1 main body or the entire cover 2. A ball screw 5 is rotatably attached to the upper portion of the entire cover 2 by a saddle 6, and one end is connected to the tip of the rotating shaft of the motor 4. The ball screw 5 is screwed with a bracket 7 fixed to the door 3. Accordingly, the servo motor 4 and the ball screw 5 constitute door opening / closing means for opening and closing the door, which is a protective cover. By rotating the servo motor 4, the ball screw 5 rotates, and the ball screw 5 is screwed. The fitted bracket 7 moves in the axial direction of the ball screw 5, and the door 3 to which the bracket 7 is fixed also moves in the axial direction of the ball screw 5. At this time, the detector 8 attached to the servo motor 4 detects the rotational position of the servo motor 4 and detects the current position of the door, thereby controlling the opening / closing operation of the door. In FIG. 1, the fully closed position of the door 3 is indicated by a solid line, and the fully open position is indicated by a two-dot chain line.

  The machine tool 1 is shown here as an example of a numerically controlled lathe. A spindle (not shown) is rotatably supported by the machine tool 1, and a chuck 9 for gripping a workpiece W is provided at the tip of the spindle. It can rotate integrally with the main shaft.

  Further, a loader beam 10 is installed with legs at both ends above the machine tool 1 in a horizontal direction parallel to the rotation axis of the chuck 9, and a loader arm 11 is parallel to the rotation axis of the chuck 9 on the loader beam 10. It is provided to be movable in a horizontal direction perpendicular to the horizontal direction. At the lower end of the loader arm 11, chucks 12a and 12b capable of gripping the workpiece W are attached. The movement of the loader arm 11 in the horizontal and vertical directions and the opening and closing of the chucks 12a and 12b are controlled by a numerical control device (not shown) as in the machine tool.

  FIG. 3 is a block diagram showing a protective cover opening / closing device of the present invention and a control circuit of a machine tool equipped with the same. In FIG. 3, 13 is a known numerical control means constituting a part of the numerical controller, an input unit 14 for inputting information such as a machining program, a machining program storage unit 15 for storing a machining program, and a machining A machining program analysis unit 16 that analyzes the program and a drive control unit 17 that controls the servo motor 18 of the drive shaft of the machine tool based on the analyzed machining program are included.

  Reference numeral 19 denotes door control means, which includes a door stop position storage unit 20 for storing a door stop position input from the input unit 14 or analyzed by the machining program analysis unit 15, and a door opening / closing signal output from the machining program analysis unit 15. The door stop position stored in the door stop position storage unit 20 is read out, the door opening / closing processing unit 21 that outputs a drive command for opening and closing the door 3, and the servo motor 4 based on the drive command of the door opening / closing processing unit 21. And a door opening / closing drive control unit 22 to be driven. The door opening / closing means 23 includes a servo motor 4 and a ball screw 5. The door control means 19 may be provided in a numerical control device of a normal machine tool as in the numerical control means 13, or may be provided as a control device different from the numerical control device of the machine tool.

  The operation of the embodiment of the cover opening / closing device configured as described above will be described based on the machining program shown in FIG.

  Before starting the machining, the machine tool 1 is in a state in which the door 3 is closed as shown by a solid line in FIG. When an instruction to start machining by a predetermined machining program is input from the input unit 14 by the operator, the machining program shown in FIG. 4 is sequentially read from the machining program storage unit 15 into the machining program analysis unit 16 from the block N0001.

  The block N0001 describes a command M600 for inputting in advance a position for stopping the door at an intermediate position that is an arbitrary position between the fully open position and the fully closed position, and a door stop position Z300. When the processing program analysis unit 16 reads the block N0001, the door stop position data Z300 is output to the door stop position storage unit 20 and stored in the door stop position storage unit 20.

  This intermediate position is such that the loader arm 11 covers the entire cover 2 of the machine tool 1 without interference between the workpiece W held on the chuck 9 of the machine tool 1 and the workpiece W held on the chuck 12 b of the loader arm 11. It is preferable to set the minimum width that can be lowered inward.

  In block N0002, a command M601 for positioning the door at an intermediate position is described. When the block N0002 is read into the machining program analysis unit 16, the machining program analysis unit 16 outputs a door intermediate position movement command to the door opening / closing processing unit 21. Based on this, the door opening / closing processor 21 reads the door stop position Z300 stored in the block N0001 from the door stop position storage 20 and outputs a door opening / closing drive command to the door opening / closing controller 22. Based on this output, the door opening / closing drive control unit 22 drives the servo motor 4, and the door 3 is driven via a ball screw 5 connected to the servo motor 4. The door 3 is at an intermediate position Z300 shown by a solid line in FIG. Stopped.

  Next, when the block N0003 is read into the machining program analysis unit 16, the chuck 9 is moved by the horizontal and vertical movement of the loader arm 11 and the opening / closing operation of the chucks 9, 12a, 12b based on the workpiece attachment / detachment command M180 described in N0003. Is transferred to the chuck 12a of the loader arm 11, the unprocessed workpiece W held on the chuck 12b of the loader arm 11 is subsequently transferred to the chuck 9, and then the loader arm is entirely Ascend above cover 2.

  Then, the command M090 described in the block N0004 is read into the machining program analysis unit 16, and the door 3 is moved to the fully closed position shown by the solid line in FIG. Cover with cover 2 and door 3.

  Subsequently, when the block N0005 is read into the machining program analysis unit 16, the tool post (not shown) is moved to the positions Z500 and X500 farthest from the chuck 9 by the G00 command by the drive control unit 17 and the servo motor 18 and the like. The tool T1 to be used is determined.

  Next, the block N0006 is read into the machining program analysis unit 16 and the tool post moves to the points Z105 and X105 at which machining of the workpiece is started, and the spindle (not shown) to which the chuck 9 is attached is rotated by the M03 command, and the following block After N0007, the workpiece is processed.

  When the machining of the workpiece is completed, the tool post is retracted by fast-forwarding by the G00 command to the positions Z500 and X500 farthest from the chuck 9 in block N0020, and then the chuck 9 is attached by the M05 command described in block N0021. After the rotation of the spindle (not shown) is stopped, the machining is ended by the M02 command of the block N0022.

  An example of another embodiment of the cover opening and closing device of the present invention will be described. FIG. 5 shows information stored in the door stop position storage unit 20. In this embodiment, a plurality of commands M6011, M6012, and M6013 are provided in advance to stop the door 3 at the intermediate position, and the door stop position corresponding to each command is stored. This information is input in advance by the operator from the input unit 14 and stored in the door stop position storage unit 20 before processing by the machine tool.

  The operation of the cover opening / closing device in this embodiment will be described based on the machining program shown in FIG.

  Before starting the machining, the machine tool 1 is in a state in which the door 3 is closed as shown by a solid line in FIG. When an instruction to start machining by a predetermined machining program is input from the input unit 14 by an operator, the machining program shown in FIG. 6 is sequentially read from the machining program storage unit 15 to the machining program analysis unit 16 from the block N0001 and executed. Is done.

  In block N0001, M6012, which is a command for positioning the door at an intermediate position, is described. When the block N0001 is read into the machining program analysis unit 16, the machining program analysis unit 16 outputs a door intermediate position movement command to the door opening / closing processing unit 21. Based on this, the door opening / closing processing unit 21 reads the door stop position Z300 corresponding to M6012, as shown in FIG. 5, from the door stop positions previously input by the operator and stored in the door stop position storage unit 20, and the door is opened. Output to the open / close control unit 22. Based on this output, the door opening / closing drive control unit 22 drives the servo motor 4, and the door 3 is driven via a ball screw 5 connected to the servo motor 4. The door 3 is at an intermediate position Z300 shown by a solid line in FIG. Stopped.

  Next, when the block N0002 is read into the machining program analysis unit 16, the chuck 9 is moved by the horizontal and vertical movement of the loader arm 11 and the opening / closing operation of the chucks 9, 12a, 12b based on the workpiece attachment / detachment command M180 described in N0002. Is transferred to the chuck 12a of the loader arm 11, the unprocessed workpiece W held on the chuck 12b of the loader arm 11 is subsequently transferred to the chuck 9, and then the loader arm is entirely Ascend above cover 2. The operations after the block N0003 are the same as those after the block N0004 shown in FIG.

  According to this embodiment, by registering a plurality of door intermediate positions in advance, there is no need to describe intermediate position coordinates on the machining program, and a plurality of intermediate positions are used in one machining program. Is possible. This is because, for example, when a large number of workpieces are continuously machined, when a machined workpiece W is unloaded from the machine tool 1 and an unmachined workpiece W is loaded into the machine tool 1, as described above. Although the movement of the door 3 is set to Z300 using the command M6012, the machine tool 1 has no machined workpiece when machining the first workpiece in continuous machining, so the loader is closer to the chuck. In such a case, if M6011 can be selected as a command for positioning the door to the intermediate position, the amount of movement of the door can be reduced to Z200. be able to. Even when the last workpiece in the continuous machining is completed, there is no workpiece to be machined next in the loader chuck 12, so that the loader is lowered into the machine tool at a position closer to the chuck. Therefore, the amount of movement of the door can be reduced by instructing M6011 in the same manner.

  In the above description, the door stop position is read from the door stop position storage unit 20 based on the door opening command described in the machining program, but the machining program is unique to the workpiece. In this case, the door stop position is stored in the door stop position storage unit 20 so as to correspond to the machining program for each workpiece, and the door stop position storage unit 20 is used as a machining program when a door open signal is input. You may make it read the stop position of a corresponding door.

  An example of still another embodiment of the cover opening / closing device of the present invention will be described based on a machining program shown in FIG.

  The block N0001 describes M601 which is a command for positioning the door at an intermediate position, and a door stop position Z300. When the block N0001 is read into the machining program analysis unit 16, the machining unit program analysis unit 16 outputs M601, which is a command for positioning the door to an intermediate position, and the door stop position Z300 to the door opening / closing processing unit 21. The door opening / closing processor 21 instructs the door opening / closing controller 22 to move the door to Z300. Based on this command, the door opening / closing drive control unit 22 drives the servo motor 4, and the door 3 is driven via a ball screw 5 connected to the servo motor 4. The door 3 is at an intermediate position Z 300 shown by a solid line in FIG. Stopped. The operations after the block N0002 are the same as those after the block N0002 of the second embodiment shown in FIG. In this embodiment, the door stop storage unit 20 is not necessary.

  In the above-described embodiment, the ball screw 5 is used as means for transmitting the drive of the servo motor 4. However, the present invention is not limited to this. For example, the ball screw 5 is provided on the machine tool 1 or the entire cover 2. A sprocket is supported rotatably at two locations with approximately the same interval as the length of, and a chain is wound around the sprocket to connect a part of the chain to the door and one sprocket is driven by a servo motor 4 You may make it do.

  Moreover, although the door of the machine tool having the entire cover has been described, the present invention is not limited to this, and can be similarly applied to a partial protective cover referred to as a splash guard or the like. Further, although a lathe has been described as an example of a machine tool, the present invention is not limited to a lathe, and can naturally be applied to various machine tools such as a machining center and a grinding machine.

It is a machine tool which shows one Embodiment of this invention, Comprising: It is a front view which shows the state which the protective cover stopped in the fully closed position. It is a machine tool which shows one Embodiment of this invention, Comprising: It is a front view which shows the state which stopped in the intermediate position which is a required opening width | variety. It is a block diagram which shows the control circuit of the protective cover opening / closing apparatus of this invention. It is a figure which shows the process program which shows operation | movement of Example 1 of this invention. It is a table | surface which shows the data memorize | stored in the door stop position storage part 20 of Example 2 of this invention. It is a figure which shows the process program which shows operation | movement of Example 2 of this invention. It is a figure which shows the process program which shows operation | movement of Example 3 of this invention. It is a conventional machine tool, Comprising: It is a front view which shows the state which the protective cover stopped in the fully closed position. It is a conventional machine tool, Comprising: It is a front view which shows the state which the protective cover stopped in the fully open position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Machine tool 2 Whole cover 3 Door 4 Servo motor 5 Ball screw 6 Sasae 7 Bracket 8 Detector 9 Chuck 10 Loader beam 11 Loader arms 12a and 12b Chuck 13 Numerical control means 14 Input unit 15 Processing program storage unit 16 Processing program analysis unit 17 drive control unit 18 servo motor 19 door control unit 20 door stop position storage unit 21 door opening / closing processing unit 22 door opening / closing drive control unit 23 door opening / closing unit W workpiece

Claims (2)

Provided on numerically controlled machine tools that machine workpieces based on machining programs,
A protective cover movably mounted on the machine tool body;
Protective cover opening and closing means for opening and closing the protective cover;
Protective cover control means for controlling the protective cover opening and closing means based on a preset protective cover stop position;
A protective cover opening and closing device for a machine tool comprising :
The protective cover stop position is set to a fully closed position and a predetermined intermediate position between the fully closed position and the fully open position;
The protective cover control means is
Protective cover stop position storage means for storing the protective cover stop position;
A door opening / closing processor that reads a protective cover stop position stored in the protective cover stop position storage means based on a door open / close command in the machining program and outputs a door drive command;
A door opening / closing drive control unit that drives the protective cover opening / closing means based on a door drive command output from the door opening / closing processing unit,
A protective cover opening and closing device for a machine tool, which reads a protective cover stop position from a protective cover stop position storage means based on a door opening / closing command of a machining program and opens and closes the protective cover to the protective cover stop position .   2. The protective cover opening / closing device for a machine tool according to claim 1, wherein the protective cover opening / closing means comprises a servo motor and a ball screw.

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