JP2013041468A - Numerical control device with manual processing function capable of automatically changing processing directions - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a numerical control device with a manual processing function without need for changing moving directions in a parallel direction and a vertical direction.SOLUTION: It is determined whether output of a pulse signal for interpolation is 0 and when the output is not 0, it is determined that an automatic switching flag FA is 0. When the output is 0, it is determined whether or not the automatic switching flag FA is 0. When the FA is 0, a time counter is made to count up, but when the FA is not 0, the time counter is cleared (SA01-SA05). It is determined whether the time of the time counter exceeds a set time and when the time of the time counter is shorter than the set time, the process is ended, but when the time of the time counter exceeds the set time, the time counter is cleared and the automatic switching flag FA is set to 1. It is determined whether a moving direction is a parallel direction, and when the moving direction is the parallel direction, the moving direction is changed to a vertical direction, but when the moving direction is not the parallel direction, namely, the vertical direction, the moving direction is changed to the parallel direction and the process is ended (SA06-SA11).

Description

  The present invention relates to a numerical control device for controlling a machine tool, and more particularly to a numerical control device for controlling a machine tool for machining a prototype or the like.

Using a machine tool with a numerical control device, it is possible to machine a workpiece having a complicated shape at high speed and with high accuracy. In order to use the numerical control device, it is necessary to accurately define machine coordinates, machine origins, program coordinates, machining origins, etc., and create a strict machining program. Further, when machining a large number of workpieces, a machine tool controlled by an interactive numerical control device or an automatic programming device can be used. However, in some machining to create prototypes or molds, there are machine tools such as general-purpose milling machines and general-purpose lathes that require less time for setup processes such as workpiece attachment / detachment, tool attachment, and machining program creation. It is used.
However, it is difficult to perform oblique linear machining, arc machining, and the like using these general-purpose machine tools. There is a numerical control device that can process a prototype using a general-purpose machine tool to deal with such problems. For example, in Patent Document 1, a designated shape such as an oblique straight line or an arc shape is designated, and a command to move the current position of the tool in a parallel direction and a vertical direction with respect to the designated shape using a manual pulse generator or the like. A technique of a numerical control device having means for performing the above is disclosed. Here, the parallel direction means the direction along the specified shape while maintaining the distance between the current position of the tool and the specified shape, and the vertical direction is the direction along the normal direction of the specified shape from the current position of the tool. Means.

JP-A-6-1119018

The numerical control device disclosed in Patent Document 1 is provided with a switch that switches a parallel direction and a vertical direction with one handle, and the moving direction can be switched by switching the switch.
When using the numerical control device disclosed in Patent Document 1 to move a tool as shown in FIG. 11 to process a workpiece, it is described in paragraphs “0042” to “0044” of Patent Document 1. In addition, the operator must repeatedly operate the selection switch of the manual pulse generator (portion 41b described in Patent Document 1). In addition, the workpiece can be machined along the route shown in FIG. 12, but in this case, the changeover switch (the portion indicated by reference numeral 43 described in Patent Document 1) is repeatedly operated. As described above, the frequent occurrence of the operation of switching the selection switch and the changeover switch has a problem that the operability is poor for the operator and the work efficiency is hardly improved.

  Although not described in Patent Document 1, it is conceivable to prepare two handles, a parallel direction handle and a vertical direction handle, and change the moving direction by changing the handle to be operated. However, this method makes it difficult for a novice operator to learn the operation method because the number of operation objects increases.

  Therefore, an object of the present invention is to eliminate the need for an operator to switch the movement direction between the parallel direction and the vertical direction in a numerical control apparatus that commands movement of the current position of the tool in the parallel direction and the vertical direction with respect to the specified shape. A numerical control device having a manual machining function capable of automatically switching the machining direction is provided.

The invention according to claim 1 of the present application controls a machine tool that has a movable portion having at least two axes and drives the movable portion to move the tool and the workpiece relative to each other to process the workpiece. In the numerical control device, a specified shape input unit for inputting a specified shape including an oblique straight line or an arc, a graphic storage unit for storing the specified shape input by the specified shape input unit, and a pulse for interpolation according to a manual operation A movement command unit that outputs a signal, an interpolation unit that receives the pulse signal and outputs an interpolation pulse for driving the movable unit, and a pulse signal for the interpolation is output within a preset time. A movement command monitoring unit that monitors whether or not a pulse signal is not output for a certain period of time in the movement command monitoring unit, relative movement of the tool and the workpiece along the specified shape, From the current position and the tool along the normal direction of the designated shape and the relative movement of the workpiece and the movement direction automatic switching unit for switching the fixings, a numerical controller and having a.
The invention according to claim 2 is the numerical control device according to claim 1, further comprising a display unit that displays a direction of relative movement switched by the movement direction automatic switching unit.
The invention according to claim 3 has a setting unit for setting a movement amount per one relative movement of the tool and the workpiece along the normal direction of the specified shape, and the normal direction is set by the movement direction automatic switching unit. When the movement amount from the switched position after switching to the relative movement of the tool and the workpiece along the direction reaches the movement amount per one time, the direction of the relative movement of the tool and the workpiece The numerical control device according to claim 1, wherein a relative movement between the tool and the workpiece along the normal direction of the designated shape is switched from a relative movement between the tool and the workpiece along the designated shape. .

In the invention according to claim 4, the amount of movement of the relative movement of the tool and the workpiece along the normal direction of the specified shape is different in a direction approaching the specified shape and a direction away from the specified shape. The numerical control device according to claim 3, wherein the numerical control device can be set.
The invention according to claim 5 is characterized in that the amount of movement of the relative movement of the tool and the workpiece along the normal direction of the specified shape can be set by the distance from the specified shape. It is a numerical control device.
The invention according to claim 6 includes an input unit for inputting a material shape of a workpiece to be processed, an input unit for inputting tool shape information, the material shape of the workpiece, tool shape information, and the current tool status. A determination unit that determines whether the tool is out of the material shape region from the position, and the moving direction automatic switching unit is effective only when the current position of the tool is out of the material shape region. The numerical control device according to any one of claims 1 to 5.

  According to the present invention, in the numerical control apparatus that commands the movement of the current position of the tool in the parallel direction and the vertical direction with respect to the specified shape, it is possible to eliminate the need for an operator to switch the movement direction between the parallel direction and the vertical direction. A numerical control apparatus having a manual machining function capable of automatically switching the machining direction can be provided.

It is a figure explaining the outline | summary of the numerical control apparatus of this invention. It is a block diagram which shows the structure of the hardware of the numerical control apparatus of this invention. It is a figure which shows an example of a machine operation panel. It is a figure explaining the outline | summary of the numerical control method which concerns on this invention. It is a flowchart which shows the algorithm of this invention (Claims 1, 2). It is a flowchart which shows the algorithm of this invention (Claim 3). It is a figure explaining the case where the present invention is applied to processing using a milling machine. It is a figure explaining the case where this invention is applied to the process using a lathe. It is a figure explaining the process which repeats the cutting operation | movement of the parallel movement with respect to a designated shape, and finishes a designated shape. It is a flowchart which shows the algorithm of this invention (Claim 6). It is a figure explaining the outline | summary of the numerical control method of the prior art performed by switching the selection switch of a manual pulse generator. It is a figure explaining the outline | summary of the numerical control method of the prior art performed by switching a changeover switch.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram for explaining the outline of the numerical control apparatus of the present invention. The numerical control device 1 includes a graphic storage unit 2, an interpolation unit 4, an axis control circuit 18, a servo amplifier 19, a display device / MDI panel 25, and a machine operation panel 40. A handle 41a for instructing the moving direction of a manual pulse generator 41 that outputs a pulse signal for instructing the movement of the tool is attached to the machine operation panel 40 as a movement instruction unit.
The graphic storage unit 2 displays guidance information on the display device 16 via the graphic control circuit 15. Further, the graphic storage unit 2 stores specified shapes such as oblique straight lines and circular arcs that are interactively input by the operator operating the keyboard 17. The designated shape stored in the graphic storage unit 2 is displayed on the display device 16 via the graphic control circuit 15 as necessary. The keyboard 17 corresponds to the designated shape input unit of claim 1. The display device 16 corresponds to the display unit of claim 2.

The interpolation unit 4 receives the pulse signal HP from the movement command unit such as the manual pulse generator 41. Then, the interpolation unit 4 outputs an interpolation pulse CP based on the designated shape and the pulse signal HP stored in the figure storage unit 2 and sends them to the axis control circuit 18. The axis control circuit 18 receives the interpolation pulse CP output from the interpolation unit 4, generates a speed command for each axis, and sends it to the servo amplifier 19. The servo amplifier 19 drives a servo motor attached to the machine tool 20 to control the machine tool 20. The machine tool 20 includes two or more movable parts, and the movable parts are driven and controlled by a numerical control device. The machine tool 20 can machine the workpiece 200 by relatively moving the tool 131 (see FIG. 4) and the workpiece 200 (see FIG. 4). The graphic storage unit 2 and the interpolation unit 4 are executed by software as will be described later.
In this specification, the parallel direction means the direction along the specified shape while maintaining the distance between the current position of the tool and the specified shape, and the vertical direction is the normal direction of the specified shape from the current position of the tool. Means the direction along.

FIG. 2 is a block diagram showing a hardware configuration of the numerical controller according to the present invention. The CPU 11 that is a processor controls the entire numerical control device in accordance with a system program stored in the ROM 12. The graphic storage unit 2 and the interpolation unit 4 in FIG. 1 are functions by software that the CPU 11 executes according to the system program in the ROM 12. Similarly, the movement command monitoring unit and the movement direction automatic switching unit according to claim 1 and the determination unit according to claim 6 also have software functions. The RAM 13 stores temporary data of input / output signals. The nonvolatile memory 14 stores parameters, machining programs, and the like that should be retained even when the power is turned off.
The graphic control circuit 15 converts the guidance information, the input designated shape, and the like into a displayable signal and supplies the signal to the display device 16. A liquid crystal display device is used for the display device 16. The axis control circuit 18 receives an axis movement command including the interpolation pulse CP from the processor 11 and outputs and controls the axis movement command to the servo amplifier 19.

The servo amplifier 19 receives this movement command and drives a servo motor (not shown) of the machine tool 20. In addition to the servo motor, the machine tool 20 includes a machine operation panel 40 that is operated to issue a movement command, which will be described later. These components are connected to each other via a bus 30.
A PMC (programmable machine controller) 22 receives a T function signal (tool selection command) and the like via the bus 30 when the machining program is executed. Then, this signal is processed by a sequence program, a signal is output as an operation command, and the machine tool 20 is controlled. The interactive numerical control apparatus receives a status signal from the machine tool 20, performs a sequence process, and transfers a necessary input signal to the processor 11 via the bus 30.
Further, a software key 23 whose function is changed by a system program or the like is connected to the bus 30. The software key 23 is provided on the display device / MDI panel 25 together with the display device 16 and the keyboard 17.

  FIG. 3 is a diagram showing an example of a machine operation panel. A machine operation panel 40 provided in the machine tool 20 is provided with a manual pulse generator 41 and a jog feed button 42. When the manual pulse generator 41 rotates the handle 41a counterclockwise or clockwise, it outputs a pulse signal HP according to the rotation. This pulse signal HP is a two-phase pulse for determining the direction of rotation, and is sent to the processor 11 via the bus 30 to move the tool. The jog feed button 42 includes plus and minus feed buttons for “+ X”, “−X”, “+ Y”, “−Y”, “+ Z”, and “−Z” axes, and “+ GJ”, A total of eight buttons, plus and minus feed buttons, are provided corresponding to the designated shape of “−GJ”. The setting switch 42a sets the number of pulses within a certain time generated when the operator presses the jog feed button 42. Specifically, a pulse obtained by frequency-dividing a pulse from a crystal oscillator (not shown) of the setting switch 42a is input, and the pulse signal JP is output at a frequency division ratio according to the scale set by the operator.

  When the tool 131 is moved relative to the workpiece 200 along the path shown in FIG. 4 and the workpiece 200 is machined into the specified shape 130, the handle 41a in the embodiment of the present invention is turned or not turned. This means that a movement command for outputting a pulse signal for interpolation is issued in accordance with the manual operation described in Item 1. Note that it is determined that the handle 41a has been turned regardless of whether the handle 41a is rotated clockwise or counterclockwise. In the embodiment of the present invention, a movement command monitoring unit is provided for setting a time and monitoring whether or not the pulse signal for interpolation is output within the set time, and the set time and pulse are not output. In this case, the tool movement commands in the parallel direction and the vertical direction are switched. That is, if the state where the handle 41a is not rotated for a preset time continues, the direction of tool movement between the parallel direction and the vertical direction is switched.

  According to the embodiment of the present invention, the operator does not need to operate the changeover switch as in the prior art, and the tool 131 is moved along the route shown in FIG. 4 only by turning and stopping the handle 41a of the manual pulse generator 41. It becomes possible to make it. Since the operation of switching the switch does not occur repeatedly, the operability is improved. Further, in this embodiment, the jog feed button 42 is used, and in this embodiment, the handle 41a is turned within a preset time, or instead of turning the handle 41a within the preset time, the jog feed button 42 of the machine operation panel 40 is turned within the preset time. It may be a push or no push operation.

FIG. 5 is a flowchart showing the algorithm of the present invention (claims 1 and 2). Hereinafter, it demonstrates according to each step.
[Step SA01] It is determined whether or not the output of the pulse signal for interpolation is 0. If the output is 0 (ie, YES), the process proceeds to step SA02, and if the output is not 0 (ie, NO) Shifts to step SA04.
[Step SA02] It is determined whether or not the automatic switching flag FA is 0. If FA is 0 (that is, YES), the process proceeds to step SA03. If the output is not 0 (that is, NO), the process proceeds to step SA05. Transition.
[Step SA03] The time counter is incremented.
[Step SA04] The automatic switching flag FA is set to zero.
[Step SA05] The time counter is cleared and the process is terminated.
[Step SA06] It is determined whether the time of the time counter has exceeded the set time. If the time of the time counter has exceeded the set time (that is, YES), the process proceeds to step SA07. If not (ie, NO), the process is terminated.
[Step SA07] The time counter is cleared.
[Step SA08] The automatic switching flag FA is set to 1.
[Step SA09] It is determined whether or not the moving direction is the parallel direction. If the direction is the parallel direction (that is, YES), the process proceeds to step SA10. If the direction is not the parallel direction (that is, NO), the step is performed. Move to SA11.
[Step SA10] The moving direction is switched to the vertical direction, and the process ends.
[Step SA11] The moving direction is switched to the parallel direction, and the process is terminated.

  To supplement the above flowchart, Step SA01 to Step SA08 correspond to a movement command monitoring unit, and Step SA09 to Step SA11 correspond to a movement direction automatic switching unit.

  As described above, the movement command unit that outputs a pulse signal for interpolation according to the manual operation described in claim 1 means the manual pulse generator 41 and the jog feed button 42. When the handle 41a of the manual pulse generator 41 is turned, the first moving direction may be either the parallel direction or the vertical direction. “The first moving direction when automatic switching is enabled is 0: parallel direction. , 1: Vertical direction ”may be provided.

  Further, as a second embodiment of the present invention, the direction of relative movement obtained by the movement direction automatic switching unit, that is, the parallel direction or the vertical direction may be displayed on the screen (display device 16) (corresponding to “Claim 2”). ). Similarly, the signal may be transmitted to the outside so that it can be recognized by an external device. The operator can easily recognize the current direction of relative movement. Here, the relative movement means the movement of the tool 131 to move the tool 131 to the workpiece 200, or the movement of the workpiece 200 to move the workpiece 200 to the tool 131.

Next, the relative movement amount of the tool in the vertical direction of the designated shape per time will be described. When processing the path shown in FIG. 4, the operator generally performs the processing by setting the amount of movement of the tool in one vertical direction within a certain range determined by processing conditions such as the tool diameter. If machining is performed with a movement amount that is larger than the certain range, there is a possibility that uncut parts or tool breakage may occur.
The third actual mode of the present invention (corresponding to “Claim 3”) is that the tool movement along the vertical direction is performed when the amount of movement per movement in the tool movement along the vertical direction reaches a preset value. The tool movement direction is switched from tool movement to tool movement along the parallel direction. The tool is moved along the vertical direction by moving the tool 131 or by moving the workpiece 200 side.
It is assumed that the preset value is stored and stored in the nonvolatile memory 14 of the numerical controller 1 using, for example, the keyboard 17. Here, the nonvolatile memory 14 corresponds to a setting unit of claim 3.

  According to the embodiment of the present invention, in the machining as shown in FIG. 4, the tool movement along the vertical direction, that is, the cutting depth per machining can be made constant without checking the current position of the tool. Furthermore, in order to switch the direction of movement of the tool from the vertical direction to the parallel direction, it is not necessary for the operator to stop turning the handle once, thereby improving operability. As a result, it is possible to prevent uncut parts and tool breakage.

FIG. 6 is a flowchart showing the algorithm of the present invention (Claim 3). Hereinafter, it demonstrates according to each step.
[Step SB01] It is determined whether or not the moving direction is the vertical direction. If the moving direction is the vertical direction (that is, YES), the process proceeds to step SB02. If the moving direction is not the vertical direction (that is, NO), the process ends.
[Step SB02] It is determined whether or not the movement amount of the tool from the position of the tool when the movement direction automatic switching unit was executed last time is greater than or equal to the set movement amount. The process proceeds to step SB03, and if not (ie, NO), the process is terminated.
[Step SB03] The moving direction is switched to the parallel direction, and the process is terminated.

  Note that the association of the tool movement direction in each movement in the direction parallel to and perpendicular to the direction in which the handle 41a is rotated differs depending on the machining, and the association may be changed as necessary. For example, FIG. 7 is a diagram for explaining a case where the present invention is applied to processing using a milling machine. When the handle 41a is turned to the right, the tool 131 in the parallel direction is assumed to be associated with the tool moving in the direction a, and the vertical direction is in the direction b. Also, let c be the association that moves in the opposite direction to a in the parallel direction. Assuming that a and b are associated, if the handle is continuously rotated to the right by moving b, the direction of movement is switched to the parallel direction by the mechanism of the third embodiment of the present invention (corresponding to “Claim 3”). Since the association remains a, the direction of tool movement is opposite to the direction of cutting the workpiece. In this case, if the direction of turning the handle is simply reversed, the tool moves in the direction of cutting the workpiece. If it is desired to move the workpiece 200 in the direction of cutting by simply rotating the handle in the same direction, for example, when the direction of movement is switched to the parallel direction, the direction of turning the parallel handle and the direction of tool movement It is sufficient to provide a mechanism in which a and c are alternately performed for the association.

FIG. 8 shows an example of machining a lathe similar to FIG. In this example, the cutting direction in the parallel direction is only one direction due to the convenience of the tool 131. As the fourth embodiment of the present invention, the vertical movement amount of the tool 131 with respect to the specified shape 130 is set in the vertical direction movement amount in the direction shown in FIG. (Claim 4).
For example, by associating the direction of turning the handle in the parallel direction with the direction of tool movement, a and c are alternately performed, and similarly in the vertical direction, b and d are alternately performed. The machining shown in FIG. 8 can be performed only by turning or stopping.
Here, the set value of the amount of movement in the vertical direction is stored in advance in the nonvolatile memory 14 using the keyboard 17, for example.

As described above, the association of the direction of tool movement in each movement in the direction parallel to and perpendicular to the direction in which the handle is rotated differs depending on the machining, and the association may be changed as necessary. In a lathe, rough cutting may be performed by increasing the depth of cut at a position far from the specified shape, and finishing may be performed by decreasing the depth of cut as the specified shape is approached. As the fifth embodiment of the present invention, it is possible to cope with such processing by changing the amount of movement per one time in the vertical direction according to the distance from the designated shape and setting the value ( Corresponds to “Claim 5”).
Here, the amount of movement per one time in the vertical direction that changes depending on the distance from the specified shape is stored in advance in the nonvolatile memory 14 using the keyboard 17.

The machining of the path shown in FIG. 9 is a process of repeatedly performing a parallel cutting operation on the designated shape 130 to finish the designated shape. During cutting by such processing, that is, when the current position of the tool 131 is within the material region, the movement command of the tool 131 is parallel to the designated shape 130. Therefore, for example, when the operator stops the handle operation for some reason during cutting and waits for a while and then continues the machining, the tool 131 moves in the parallel direction when the handle operation is stopped. It is preferable that the movement. In the sixth embodiment of the present invention (corresponding to “Claim 6”), the material shape and the tool information are recognized, and the automatic movement direction switching according to claim 1 is performed when the current position of the tool is outside the region of the material shape. Only valid. According to the sixth embodiment of the present invention, it is possible to maintain the direction of parallel tool movement even if the handle operation is interrupted during cutting. The determination of whether or not the tool 131 is in the material region can be performed by using a known processing technique for interference check used in the numerical control device, and will not be described.
The tool shape information and the material shape of the workpiece to be processed can be stored in advance in the nonvolatile memory 14 via an interface (not shown). Here, the nonvolatile memory 14 corresponds to the input unit of claim 6.

FIG. 10 is a flowchart showing the algorithm of the present invention (Claim 6). Hereinafter, it demonstrates according to each step.
[Step SC01] The determination result of the movement command monitoring unit determines whether or not automatic switching can be performed. If automatic switching is possible (that is, YES), the process proceeds to step SC02 and automatic switching is not possible (that is, , NO), the process is terminated.
[Step SC02] It is determined whether or not the current position of the tool is outside the material shape area. If it is outside the area (that is, YES), the process proceeds to step SC03, and if it is not outside the area (that is, NO) ), The process is terminated.
[Step SC03] The process of the moving direction automatic switching unit is executed and the process is terminated.

1 Numerical control device 2 Graphic storage unit

4 Interpolation section

15 Graphic control circuit 16 Display device 17 Keyboard 18 Axis control circuit 19 Servo amplifier 20 Machine tool 23 Software key 25 Display device / MDI panel

40 Machine operation panel 41 Manual pulse generator

130 Specified shape 131 Tool

200 works

HP pulse signal JP pulse signal CP Interpolation pulse

Claims (6)

In a numerical control apparatus that has a movable part of at least two axes and controls a machine tool that processes a workpiece by driving the movable part and relatively moving the tool and the workpiece,
A designated shape input unit for inputting a designated shape including an oblique straight line or an arc;
A graphic storage unit for storing the specified shape input by the specified shape input unit;
A movement command unit that outputs a pulse signal for interpolation according to a manual operation;
An interpolation unit that receives the pulse signal and outputs an interpolation pulse for driving the movable unit;
A movement command monitoring unit for monitoring whether or not the pulse signal for interpolation is output within a preset time; and
If the movement command monitoring unit determines that a pulse signal has not been output for a certain period of time, the relative movement of the tool and the workpiece along the specified shape and the normal direction of the specified shape from the current position of the tool A moving direction automatic switching unit for switching between relative movement of the tool and the workpiece;
A numerical control device comprising:   The numerical control device according to claim 1, further comprising a display unit that displays a direction of relative movement switched by the movement direction automatic switching unit. A setting unit for setting a movement amount per one of the relative movement of the tool and the workpiece along the normal direction of the specified shape;
When the movement amount from the switched position after switching to the relative movement of the tool and the workpiece along the normal direction in the movement direction automatic switching unit reaches the movement amount per one time, the tool The direction of relative movement of the workpiece and the workpiece is switched from relative movement of the tool and workpiece along the normal direction of the specified shape to relative movement of the tool and workpiece along the specified shape. The numerical control apparatus according to 1.   The amount of movement per one relative movement of the tool and the workpiece along the normal direction of the specified shape can be set differently in a direction approaching the specified shape and in a direction away from the specified shape. Item 4. The numerical control device according to Item 3.   The numerical control device according to claim 4, wherein a movement amount per one relative movement of the tool and the workpiece along the normal direction of the specified shape can be set by a distance from the specified shape. An input unit for inputting the material shape of the workpiece to be processed;
An input unit for inputting tool shape information;
A material shape of the workpiece, shape information of the tool, and a determination unit for determining whether the tool is outside the material shape region from the current position of the tool, and
6. The numerical control device according to claim 1, wherein the moving direction automatic switching unit is effective only when the current position of the tool is outside the region of the material shape.