JP4461030B2 - Numerical control apparatus and numerical control method - Google Patents

Description

  The present invention relates to a numerical control device having function generating means for controlling axial movement of a moving body of a machine tool in response to an axial movement command in a manual axial movement operation or an automatic machining program. The present invention relates to a numerical controller that avoids mechanical collisions.

  In a known numerical control device, when a manual axis movement operation or an axis movement command in an automatic machining program is performed, a function is generated for each axis control period according to the movement direction, and the moving body of the machine tool is The movement is controlled. Conventionally, in order to avoid a mechanical collision during axis movement, a movable range is registered in advance as a variable limit position, and if the variable limit position is exceeded, the moving body decelerates to a variable limit position and stops. End function generation as follows.

  A block diagram of such a prior art is shown in FIG. In FIG. 3, a switch signal input from an NC operation panel / machine operation panel 1 including a switch for selecting an axis for manual feed, a switch for selecting a manual feed direction, and the like is sent to the input control means 2 for input. The control means 2 decodes the switch signal to generate the manual feed axis and manual feed direction data, and sends the data to the function generation means 3 as a manual operation command.

  When the function generating means 3 receives the manual operation command, the function generating means 3 starts calculating the function generation position at each axis control period in order to control the axis movement of the moving body of the machine tool. The function generation is continued, and when the manual operation command disappears, the function generation ends so that the moving body decelerates to a stop. When calculating the function generation position, a predetermined acceleration is obtained by referring to the manual feed speed data set and stored in advance as the acceleration / deceleration unit quantity for each control axis / control cycle by the feed speed data storage means 5. The function generation position is calculated so that the moving body moves axially at the speed.

  The variable limit storage means 4 stores a variable limit position set as a movable range for each control axis, and the function generating means 3 is configured to issue a manual operation command so that the moving body exceeds the variable limit position. In the case of, the function generation is terminated so as to decelerate and stop at the variable limit position. The calculated function generation position is sent to the driving means 6 at each axis control period, and the driving means 6 drives the moving body of the machine tool based on the function generation position.

  On the other hand, when a machining program name to be used is input from the NC operation panel / machine operation panel 1 and a start button of the NC operation panel / machine operation panel 1 is pressed, a program interpretation command is input from the input control means 2 to the machining program interpretation means 7. Will be notified. When the machining program interpreting means 7 receives the program interpretation command, it reads the machining program with the name of the machining program key-inputted from the machining program storage means 8, takes out every block from the head, and takes into account the tool offset or origin offset, etc. The actual tool target point and feed speed data are generated and sent to the function generating means 3 as a program control command.

  When the function generation means 3 receives the program control command, the function generation means 3 starts calculating the function generation position at each axis control period and performs deceleration stop at the target movement position in order to control the axis movement of the moving body of the machine tool. End generation. When calculating the function generation position, a predetermined acceleration is obtained by referring to the automatic feed speed data set and stored in advance as the acceleration / deceleration unit amount for each control axis / control cycle by the feed speed data storage means 5. The function generation position is calculated so that the moving body moves axially at the speed.

  The variable limit storage means 4 stores a variable limit position set as a movable range for each control axis, and the function generation means 3 can execute a program control command so that the moving body exceeds the variable limit position. In the case of, the function generation is terminated so as to decelerate and stop at the variable limit position. The calculated function generation position is sent to the driving means 6 at each axis control period, and the driving means 6 drives the moving body of the machine tool based on the function generation position.

  As a method for automatically avoiding the interference between the tool and the material, Patent Document 1 calculates the interference area of the outer surface of the material from the material shape data and the mounting position on the machine tool, and the tool enters this interference area. A method for detecting this is disclosed.

  Further, Patent Document 2 discloses a method of predicting a tool edge position and stopping the tool before it interferes with the prohibited region by decelerating when interference occurs at the predicted position.

JP 58-163001 JP-A-8-152908

  As described above, the conventional collision avoidance method is uniform because the movable range for each control axis is registered in advance as a variable limit position, and interference within the movable range of each control axis is thus achieved. Collisions with objects such as materials, jigs, tailstocks, etc. are artificially avoided by the operator's careful operation, or by confirming that there is no collision by executing a machining program step by step before automatic operation. Must.

  At this time, if the moving body approaches the interference object at a high speed, the operator detects the danger of the collision, lowers the override, and slowly approaches the interference object to perform an operation while visually checking whether it interferes. There is a problem that the burden is large and it takes a long time for confirmation.

  In addition, as a method for automatically avoiding interference between the tool and the material, the technique of Patent Document 1 does not consider interference until it enters the interference area, and thus suddenly stops without sufficient deceleration. . Furthermore, in the technique of Patent Document 2, since the predicted cutting edge position is calculated from the previous sampling position and the current position, it does not necessarily match the actual tool movement position. In either case, the axis movement operation should be started or resumed with fine details while confirming the presence or absence of interference, and the operation should be decelerated and stopped at the desired position with high accuracy to avoid interference. There was a problem that it was not possible.

  The present invention has been made under such circumstances, and the object of the present invention is to approach any interference object regardless of the operator's operation in all manual / automatic operations. It is an object of the present invention to provide a numerical control device capable of finely controlling the movement of the shaft so that the vehicle can be decelerated when it is detected and the collision can be avoided safely and surely with high accuracy by avoiding a collision.

In order to achieve the above object, a numerical control device according to the present invention includes a function generating means for generating a function for controlling the axial movement of a moving body of a machine tool according to an axial movement command, and the moving body. Numerical data control comprising: means for storing the shape data of a moving object and shape data of an interfering object that may interfere with the moving object; and interference checking means for confirming the presence or absence of interference between the moving object and the interfering object The apparatus calculates a virtual movement position that is separated from the current position by a distance corresponding to the commanded axis movement command at every predetermined cycle, and is necessary for deceleration stop from the speed at the virtual movement position of the moving body. has a proximity check value calculating means for determining a proximity check value of the moving body to calculate a such distance, the interference checking unit before starting the function generator in accordance with said axis movement command, the Each periodic, virtually the shape data of the moving body is moved in the virtual movement position, shape data of the virtual moving the region obtained by adding the proximity check value to the shape data of the mobile body and the interfering object at the position When the interference check means confirms that there is interference, the function generating means decelerates the moving body from the current position in the commanded axial movement direction and confirms that there is no interference. In this case, a function is generated so that the moving body is accelerated and moved from the current position in the commanded axial movement direction .

The numerical control method according to the present invention includes a step of storing shape data of a moving body of a machine tool and shape data of an interferer that may interfere with the moving body, and movement of the machine tool in accordance with an axis movement command. In a numerical control method including a function generation step for generating a function for controlling movement of an axis of a body, and an interference check step for confirming the presence or absence of interference between the moving body and the interference object, a predetermined cycle determined in advance Each time, a virtual position that is separated from the current position by a distance corresponding to the commanded axis movement command is calculated, and a distance required for deceleration stop is calculated from the speed at the virtual moving position of the moving body, includes a proximity check value calculation step of obtaining a proximity check value, the interference checking process, before starting the function generator in accordance with said axis movement command for each predetermined period, of virtually the moving body The Jo data is moved to the virtual mobile location to check for interference between the shape data of said virtual moving the moving object region and the interfering object on the shape data added with the proximity check value at the position, the function generator When the interference check means confirms that there is interference, the process decelerates the moving body from the current position in the commanded axial movement direction, and when it is confirmed that there is no interference, the moving body is instructed from the current position. The function generation is performed so as to accelerate the movement in the axis movement direction .

  Further, in the numerical control method according to the present invention, the interference check step includes a region in which the proximity check value is added to the shape data in the traveling direction or in all directions with respect to the axial movement direction of the moving body and the shape data of the interference object. The presence or absence of interference is confirmed.

  According to the present invention, when an axis movement command is issued by manual operation or automatic operation operation in a machining program, the distance required to decelerate and stop from the speed of the moving body is calculated before the moving body starts moving. Then, the interference check using the shape model is performed, and according to the result of the interference check, it is possible to decelerate or accelerate by generating a function for moving the moving body, so that it is not depending on the operation of the operator. It is possible to provide a numerical control device that can perform fine axis movement control so that a collision can be avoided by approaching an interference object accurately and safely regardless of any operation.

  Hereinafter, embodiments of the present invention (hereinafter referred to as embodiments) will be described with reference to the drawings.

FIG. 1 is a block diagram showing an example of the configuration of a numerical control device having a collision avoidance function in the present embodiment. Reference numerals 1, 2, 4, 5, 6, 7, and 8 have the same functions as those in FIG. The description is omitted.

  The three-dimensional data storage means 11 stores and stores three-dimensional data such as materials, jigs, tools, machine tool elements, etc. that may cause interference with the movement of the axis of the machine tool moving body. Of these, the moving body that moves by the axis movement operation and the interference that may interfere with this movement differ depending on the configuration of the machine tool, and are limited in the description of the following embodiments. Not.

  The proximity check value calculation unit 9 receives a manual operation command from the input control unit 2 or a program control command from the machining program interpretation unit 7. The proximity check value calculation means 9 is a virtual movement position for each axis control period according to the movement axis and the movement direction so that the presence / absence of interference using the three-dimensional data of the moving object and the three-dimensional data of the interference object can be confirmed. Is calculated, the distance required to decelerate and stop is calculated from the axis moving speed at this time, and this value is used as the proximity check value.

  When calculating the virtual movement position, a predetermined acceleration and speed are determined by referring to the feed speed data set and stored in advance as the acceleration / deceleration unit quantity for each control axis and each control cycle by the feed speed data storage means 5. The virtual moving position is calculated so that the moving body moves along the axis. The variable limit storage means 4 stores a variable limit position set as a movable range for each control axis. When the moving body exceeds the variable limit position, the variable limit position is decelerated and stopped at the variable limit position. The virtual movement position is calculated as follows.

  Interference presence / absence confirmation means 10 creates a proximity check moving body composed of a region in which a proximity check value is added to the three-dimensional data of the moving body, moves the proximity check moving body to a virtual movement position, and performs three-dimensional data of the interference object. And whether there is an overlap in the three-dimensional space. If there is an overlap, it is confirmed that there is proximity, and if there is no overlap, it is confirmed that there is no proximity.

  As described in FIG. 3 of the prior art, the function generating means 3A calculates the function generating position at each axis control period in order to control the axis movement of the moving body of the machine tool according to the manual operation command or the program control command. However, the present invention operates as follows.

  First, the function generating means 3A starts function generation after confirmation of the presence or absence of interference is confirmed by the movement of the moving body. As described above, since the interference presence / absence confirmation unit 10 confirms the presence / absence of proximity based on the virtual movement position, when it is confirmed that there is no proximity, the function generation position is calculated as usual. If it is confirmed that there is proximity, deceleration processing similar to the conventional deceleration stop to the variable limit position is performed.

  By performing the deceleration process, the proximity interference check value in the next axis control cycle becomes smaller than the previous value, and as long as the proximity is continued, the deceleration is continued and finally stopped. In addition, acceleration is started when there is no proximity on the way.

  In addition, the description of the present embodiment has been performed with a linear axis, but is not limited to the linear axis, and the same applies to a rotary axis that rotates a moving body, such as turning of a tool post on which a tool is mounted on a lathe, Needless to say, in a machining center, the present invention can also be applied to swiveling of a tool changing arm that is responsible for exchanging a tool mounted on a spindle and a magazine pot tool.

  Next, the operations of the proximity check value calculation means 9, the interference presence / absence confirmation means 10 and the function generation means 3A in manual operation will be specifically described using a lathe as an example with reference to FIG. In FIG. 2, the tool T represents three-dimensional data of a moving object, and the interference object W represents three-dimensional data of an interference object that may cause interference when the tool T moves.

  Here, a case where the manual feed switch F is pressed and the tool T passes through P1 and Q1 at the maximum feed speed and approaches the interference object W will be described. In FIG. 2A, when passing the position P1, the proximity check value calculation means 9 calculates the distance required to decelerate and stop from the speed of the tool T at the position P1 to obtain the proximity check value. The interference presence / absence confirmation means 10 creates a proximity check region P2 in which the proximity check value is added to the shape data of the tool T, moves it to the virtual movement position p2, and overlaps the three-dimensional data of the interference W in the three-dimensional space. Check for the presence or absence. Referring to the feed speed data set and stored in advance as the acceleration / deceleration unit quantity for each control axis and each control cycle by the feed speed data storage means 5, calculation is made so that the moving body moves at a predetermined acceleration and speed. Is done. Since no interference occurs in the movement to p2, the function generating means 3A creates a movement command to P2 which is the same position as p2.

  When the movement to P2 is performed, the proximity check area P2 is moved to the virtual movement position p3 in the same manner, and the presence or absence of interference is confirmed. Here, since interference of the interfering object W is confirmed, the function generating means 3A performs a deceleration process and creates a movement command to P3. When the movement to P3 is performed, the proximity check value calculation unit 9 calculates a proximity check value smaller than the previous time because the previous deceleration process was performed, and the interference presence / absence confirmation unit 10 creates a proximity check region P3. It is moved to the virtual movement position p4 and the presence or absence of interference with the interference object W is confirmed. Since interference is also confirmed here, the function generating means 3A further performs deceleration processing and creates a movement command to P4. By repeating this, deceleration is performed at each axis control period, and the tool T stops immediately before the interfering object W.

  When passing the position of Q1 shown in FIG. 2-B, the proximity check value calculation means 9 calculates the distance necessary for decelerating and stopping from the speed of the tool T at the position of Q1 to obtain the proximity check value. . In the interference presence / absence confirmation means 10, a proximity check region Q2 in which the proximity check value is added to the shape data of the tool T is created, moved to the virtual movement position q2, and overlapped with the three-dimensional data of the interference W in the three-dimensional space. Check for the presence or absence. Here, since no interference occurs, the function generating means 3A creates a movement command to Q2, which is the same position as q2. When moving to the position of Q2, the proximity check region Q2 is similarly moved to the virtual movement position q3 to confirm the presence or absence of interference.

  Here, since interference of the interfering object W is confirmed, the function generating means 3A performs a deceleration process and creates a movement command to Q3. When the movement to Q3 is performed, the proximity check value calculation unit 9 calculates a proximity check value smaller than the previous time because the previous deceleration process was performed, and the interference presence / absence confirmation unit 10 creates a proximity check region Q3. It is moved to the virtual movement position q4 and the presence / absence of interference with the interfering object W is confirmed. Since the interference is also confirmed here, the function generating means 3A further performs a deceleration process and creates a movement command to Q4.

  When the movement to Q4 is performed, the proximity check value calculation means 9 calculates a proximity check value smaller than the previous time because the previous deceleration process was performed, and the interference presence confirmation means 10 creates a proximity check area Q4. Then, it is moved to the virtual movement position q5 and the presence / absence of interference with the interfering object W is confirmed. Here, since no interference is confirmed, the function generating means 3A performs acceleration processing and creates a movement command to Q5. The movement command to Q5 is determined by referring to the feed speed data set and stored in advance as the acceleration / deceleration unit quantity for each control axis and each control cycle by the feed speed data storage means 5 with a predetermined acceleration and speed. Is calculated to move along the axis.

  When the movement to Q5 is performed, the proximity check value calculation means 9 calculates a proximity check value larger than the previous time because the previous acceleration process was performed, and the interference presence confirmation means 10 creates a proximity check area Q5. It is moved to the virtual movement position q6 and the presence / absence of interference with the interfering object W is confirmed. Again, since no interference is confirmed, the function generating means 3A performs acceleration processing and creates a movement command to Q6.

  In this way, when approaching the interference object W, the deceleration process is automatically performed, and when moving away from the interference object W, the acceleration process is automatically performed to automatically avoid the interference object W. In the present embodiment, the proximity check value is added to the entire circumference of the moving body. However, the proximity check value can be suitably processed even if it is added in the axial movement direction or the vertical and horizontal directions.

  In the description of the present embodiment, the case of one axis has been described, but it goes without saying that the case of two axes or more can also be realized by the same method.

  Furthermore, in the present embodiment, the shape data of the moving object and the interference object has been described as three-dimensional data. However, the shape may be expressed by two-dimensional data, and the presence or absence of interference may be confirmed by two-dimensional data. .

It is a block diagram which shows one Example of the numerical control apparatus which concerns on this invention. It is a figure explaining the specific operation | movement with the lathe which concerns on this invention. It is a figure explaining the specific operation | movement with the lathe which concerns on this invention. It is a block diagram which shows one Example of the numerical control apparatus which concerns on a prior art.

Explanation of symbols

  1 NC operation panel / machine operation panel, 2 input control means, 3, 3A function generation means, 4 variable limit storage means, 5 feed speed data storage means, 6 drive means, 7 machining program interpretation means, 8 machining program storage means, 9 proximity check value calculation means, 10 interference presence confirmation means, 11 three-dimensional data storage means.

Claims (3)

Function generating means for generating a function for controlling axial movement of a moving body of a machine tool in accordance with an axis movement command, shape data of the moving body, and shape data of an interferer that may interfere with the moving body, In the numerical control device, comprising: means for storing, and interference check means for confirming the presence or absence of interference between the moving body and the interference object,
The virtual movement position that is separated from the current position by a distance corresponding to the commanded axis movement command is calculated every predetermined cycle, and the distance required for deceleration stop is calculated from the speed at the virtual movement position of the moving body. Proximity check value calculation means for calculating and determining as a proximity check value of the mobile body,
The interference check means includes
Before starting the function generation according to the axis movement command, the shape data of the moving body is virtually moved to the virtual moving position at each predetermined period, and the shape of the moving body at the virtual moving position is Check the presence or absence of interference between the area added the proximity check value to the data and the shape data of the interferer,
The function generating means is
When the interference checking means confirms that there is interference, the moving body is decelerated and moved in the commanded axial movement direction from the current position, and when it is confirmed that there is no interference, the movable body is commanded from the current position in the axial movement direction. A numerical control device characterized by generating a function to accelerate the movement to A step of storing shape data of the moving body of the machine tool and shape data of an interferer that may interfere with the moving body, and a function for controlling the axial movement of the moving body of the machine tool in accordance with an axis movement command In a numerical control method including a function generation step for performing generation, and an interference check step for confirming the presence or absence of interference between the moving body and the interference object,
Calculates a virtual position that is separated from the current position by a distance corresponding to the commanded axis movement command at predetermined intervals, and calculates a distance required for deceleration stop from the speed of the moving body at the virtual movement position. A proximity check value calculation step to obtain as a proximity check value of the mobile body,
The interference check process includes:
Before starting the function generation according to the axis movement command, the shape data of the moving body is virtually moved to the virtual moving position at each predetermined period, and the shape of the moving body at the virtual moving position is Check the presence or absence of interference between the area added the proximity check value to the data and the shape data of the interferer,
The function generation step includes
When the interference checking means confirms that there is interference, the moving body is decelerated and moved in the commanded axial movement direction from the current position, and when it is confirmed that there is no interference, the movable body is commanded from the current position in the axial movement direction. A numerical control method characterized in that a function is generated so as to move to an acceleration. The numerical control method according to claim 2,
In the interference check step, the presence or absence of interference between the area in which the proximity check value is added to the shape data in the traveling direction or all directions with respect to the axial movement direction of the moving body and the shape data of the interference object is confirmed. Numerical control method.

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