Numerical controller

Abstract

A numerical controller according to one embodiment of the present disclosure, which is capable of shortening machining time, controls a machining apparatus for machining a workpiece by gas through a machining head in accordance with a machining program including a plurality of commands, and includes a set time acquisition unit that acquires a set time of the workpiece by setting the set time, a setting time acquisition unit that acquires a setting time required from the start of supply of the gas until the supply state of the gas becomes a requested state; a pre-reading unit that pre-reads the command of the machining program; a gas supply determination unit that determines, on the basis of the command pre-read by the pre-reading unit, a start timing at which the supply of the gas is started such that a specific command that the supply of the gas is required is executed after the set time has elapsed since the start of the supply of the gas; and a gas supply control unit that causes the processing device to supply the gas at the start timing determined by the gas supply determination unit.

Description

Technical Field

[0001] The invention relates to a numerical control device. Background Art

[0002] For example, the following technology is known: when performing welding, cutting, etc., in order to blow away the material or prevent the oxidation of the material, a suitable gas is blown to the processing point. Before the pressure of the gas reaches a predetermined pressure, it takes a relatively long time compared to the start of processing performed by laser, electric current, etc. Therefore, in the conventional processing, the supply of gas is started after the tool such as a laser head is arranged at the processing point, and the processing is started after waiting for the gas pressure to rise sufficiently.

[0003] Patent document 1 discloses the following technology: in order to shorten the processing time and reduce the gas consumption, the rate of increase of the gas pressure after the start of gas supply is monitored, the laser is started before the gas pressure reaches a predetermined pressure, and the laser is irradiated after the gas pressure reaches the predetermined pressure.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-68305 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the method described in Patent Document 1, the waiting time at the processing point can be reduced, but further shortening of the processing time is desired.

[0009] Means for solving problems

[0010] A numerical control device of one embodiment of the present invention controls a processing device that processes a workpiece by using a gas to pass through a processing head according to a processing program including multiple commands, and the numerical control device comprises: a setting time acquisition unit, which acquires the setting time required from the start of supplying the gas to the time when the supply state of the gas becomes the requested state; a pre-reading unit, which pre-reads the commands of the processing program; a gas supply determination unit, which determines the start timing of starting to supply the gas based on the commands pre-read by the pre-reading unit, so that a specific command requiring the supply of the gas is executed after the setting time has passed since the start of supplying the gas; and a gas supply control unit, which causes the processing device to supply the gas at the start timing determined by the gas supply determination unit.

[0011] Effects of the Invention

[0012] According to the present disclosure, processing time can be shortened. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a block diagram showing a configuration of a numerical control device according to an embodiment of the present disclosure.

[0014] FIG. 2 is a timing chart illustrating the relationship between a machining program and a control output in the numerical control device of FIG. 1 . DETAILED DESCRIPTION

[0015] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a block diagram showing a configuration of a numerical controller 1 according to an embodiment of the present disclosure.

[0016] The numerical control device 1 controls a processing device 100. The processing device 100 is a device that processes a workpiece (not shown) by using gas through a processing head (not shown). Examples of processing performed by the processing device 100 include laser welding, laser cutting, arc welding, plasma cutting, gas welding, gas cutting, etc. In the illustrated embodiment, it is assumed that the processing device 100 has a laser head that irradiates a laser to the workpiece as a processing head, and also has: a gas nozzle 110 that sprays gas to an area irradiated with the laser; a servo amplifier 120 that drives a plurality of motors that move the laser head and the workpiece relative to each other; and a laser oscillator 130 that supplies laser to the laser head.

[0017] The numerical control device 1 controls the processing device 100 according to a processing program including a plurality of commands. The numerical control device 1 has, for example, a memory, a processor, an input / output interface, etc., and can be realized by a computer device that executes an appropriate control program. The numerical control device 1 has a settling time storage unit 11, a program storage unit 12, a settling time acquisition unit 13, a pre-reading unit 14, a gas supply determination unit 15, a gas stop determination unit 16, a gas supply control unit 17, a movement determination unit 18, a movement standby setting unit 19, a movement control unit 20, a laser determination unit 21, a laser standby setting unit 22, and a laser control unit 23. In addition, these structural elements are obtained by classifying the functions of the numerical control device 1 related to the present invention, and may not be structures that can be clearly distinguished in physical structure and program structure.

[0018] The settling time storage unit 11 stores the settling time required from the start of gas supply until the gas supply state becomes the requested state. As the requested gas supply state, for example, it is assumed that the gas pressure is above the target pressure, the gas concentration is above the target concentration, etc. The settling time may be stored in multiple numbers corresponding to the type of gas, the target pressure, etc., or may be stored as a function of the target value.

[0019] The program storage unit 12 stores a machining program that describes a machining process of a workpiece by the machining device 100. The machining program can be described in a programming language such as G code, for example. The program storage unit 12 may store a plurality of machining programs.

[0020] The settling time acquisition unit 13 acquires the settling time of the gas used in the process being executed, that is, reads the settling time from the settling time storage unit 11 and stores it in the work memory.

[0021] The pre-reading unit 14 pre-reads the commands of the machining program. That is, the commands that are later than the commands currently being executed by the machining device 100 are read from the program storage unit 12 in advance and stored in the work memory. In this way, the numerical control device 1 pre-determines the subsequent operation schedule of the machining device 100, and the machining device 100 executes machining according to the machining program without causing delays caused by calculations.

[0022] The gas supply determination unit 15 determines the start timing of starting the gas supply based on the command pre-read by the pre-read unit 14, so that the command requiring the gas supply (hereinafter referred to as the specific command) is executed after the set time has passed since the start of the gas supply. That is, the gas supply determination unit 15 sets the start timing as the time that is earlier than the time when the specific command is started in the machining program by the set time. In addition, the gas supply determination unit 15 determines the stop timing based on the command pre-read by the pre-read unit 14, so that the gas supply is stopped at the same time as the execution of the specific command is completed or after a predetermined time delay.

[0023] As a specific command, in addition to the command indicating the start of processing using gas, there can also be cited a command indicating the start of gas supply. In a processing program made for a conventional numerical control device, a command indicating the start of gas supply is usually set immediately before the command indicating the start of processing. Therefore, when the gas supply determination unit 15 performs processing according to a conventional processing program, it can also regard the command indicating the start of gas supply as a command accompanying the command indicating the start of processing, and determine the start timing of gas supply. In addition, the gas supply determination unit 15 can also ignore the command indicating the start of gas supply and determine the start timing of gas supply based on the command indicating the start of processing. Therefore, the processing program made for the numerical control device 1 can omit the command indicating the start of gas supply.

[0024] The start timing can be determined by the time or by the position of the processing head. Usually, the processing head is moved to the processing point just before the processing starts. Therefore, by determining the position of the processing head corresponding to the start timing according to the moving speed for positioning the processing head, the gas supply can also be started appropriately.

[0025] When the gas supply determination unit 15 cannot ensure the settling time before executing a specific command, for example, when there is a specific command after the program starts, after the processing conditions are obtained, after the command to prohibit gas injection, etc., the settling time cannot be traced back from the start time of the specific command. In such a case, the time obtained by subtracting the insufficient time from the settling time, that is, the time that can be traced back to the maximum extent from the start time of the specific command, is calculated. In addition, the insufficient time can also be set to a value obtained by adding a margin to a simple difference or a value obtained by multiplying it by a safety factor.

[0026] The gas stop determination unit 16 determines whether to stop the gas supply after the execution of the specific command is completed based on one or more commands following the specific command. Specifically, when the time from the stop timing of the gas supply corresponding to the specific command serving as a reference to the start timing of the gas supply corresponding to the next specific command is less than a predetermined continuation threshold, the gas stop determination unit 16 determines that the gas supply corresponding to the specific command serving as a reference should not be stopped but the gas supply should be continuously continued until the gas supply corresponding to the next specific command is completed. That is, the gas stop determination unit 16 corrects the gas supply stop timing of the gas supply schedule determined by the gas supply determination unit 15. In addition, the continuation threshold may also be zero. In addition, when the stop timing of the specific command serving as a reference is later than the start timing of the next specific command, the gas supply should of course be continuously performed.

[0027] The gas supply control unit 17 controls the processing device 100 to supply gas at the start timing determined by the gas supply determination unit 15 . More specifically, the gas supply control unit 17 controls the gas nozzle 110 according to the schedule determined by the gas supply determination unit 15 and corrected by the gas stop determination unit 16 .

[0028] The movement determination unit 18 determines the movement profile of the machining head based on the command pre-read by the pre-read unit 14. Specifically, the movement determination unit 18 calculates the coordinates of the machining head at each time or the position of the drive motor that determines the coordinates.

[0029] Immediately before starting the machining, the movement standby setting unit 19 stops the relative movement between the machining head and the workpiece for the insufficient time calculated by the gas supply determination unit 15. That is, the movement standby setting unit 19 corrects the movement profile determined by the movement determination unit 18 in such a way as to delay the start of the machining until the gas supply state becomes the requested state.

[0030] The movement control unit 20 inputs a command value to the servo amplifier 120 so as to relatively move the machining head according to the outer shape determined by the movement determination unit 18 and corrected by the movement standby setting unit 19 .

[0031] The laser determination unit 21 determines the profile of the time change of the output setting value of the laser oscillator 130 based on the command pre-read by the pre-read unit 14 .

[0032] The laser standby setting unit 22, like the mobile standby setting unit 19, delays the start of laser output by the insufficient time calculated by the gas supply determination unit 15 immediately before the start of processing. That is, the laser standby setting unit 22 corrects the shape of the laser output determined by the laser determination unit 21 in such a way as to delay the start of processing until the gas supply state becomes the requested state.

[0033] The laser control unit 23 controls the laser oscillator 130 so that the output of the laser light changes in accordance with the outer shape determined by the laser determination unit 21 and corrected by the laser standby setting unit 22 .

[0034] FIG2 shows a simplified example of the relationship between the time changes described in the processing program and the time changes of the control output (the output of the gas supply control unit 17, the movement control unit 20, and the laser control unit 23) for the gas supply, the movement of the processing head, and the output of the laser in the numerical control device 1. In addition, the processing head is programmed to move at a high speed during positioning and at a low speed during processing. Within the scope of the figure, the processing program includes four processings, and between the third and fourth processings, the processing conditions are changed, such as a change in the type or pressure of the gas, and the gas supply needs to be stopped at this time.

[0035] In the control output of this example, the first and second gas supply for processing starts at a time before the start of processing (head movement and laser output) by the set time. As for the third gas supply for processing, since the time interval between the second processing and the third processing is shorter than the set time, the gas supply for processing is continuously performed from the second processing. The fourth gas supply for processing starts after the previous condition change, but since the set time cannot be ensured at the start time of processing in the processing program, the start of processing is delayed by insufficient time. By setting the shape of the control output to such a shape, in the numerical control device 1, laser processing starts after the gas supply state becomes the requested state, so that appropriate processing can be ensured.

[0036] The above is a description of the embodiments of the present disclosure, but the present invention is not limited to the above embodiments. In addition, the effects described in the above embodiments are merely examples of the preferred effects produced by the present invention, and the effects of the present invention are not limited to the effects described in the above embodiments. As an example, the numerical control device of the present invention may not have a gas stop determination unit, a mobile standby setting unit, and a laser standby setting unit. In addition, the numerical control device of the present invention may also be configured not to have a set time storage unit and a program storage unit, and the set time acquisition unit and the pre-reading unit acquire information from the outside.

[0037] Explanation of symbols

[0038] 1 Numerical control device

[0039] 11 Setting time storage unit

[0040] 12. Program storage unit

[0041] 13 Setting time acquisition unit

[0042] 14 Pre-reading

[0043] 15 Gas supply determination unit

[0044] 16 Gas stop determination unit

[0045] 17 Gas supply control unit

[0046] 18. Mobile decision section

[0047] 19 Mobile standby setting section

[0048] 20 Mobile Control Unit

[0049] 21 Laser Decision Department

[0050] 22 Laser standby setting section

[0051] 23 Laser control unit

[0052] 100 Processing equipment

[0053] 110 Gas Nozzle

[0054] 120 Servo amplifier

[0055] 130 Laser oscillator.

Claims

1. A numerical control device, which controls a processing device according to a processing program containing a plurality of commands, wherein the processing device processes a workpiece by using gas through a processing head, characterized in that: The numerical control device comprises: a settling time acquisition unit that acquires a settling time required from the start of supply of the gas until the supply state of the gas becomes a requested state; a pre-reading unit for pre-reading the command of the machining program; a gas supply determination unit that determines a start timing of starting the supply of the gas based on the command pre-read by the pre-read unit so that a specific command requiring the supply of the gas is executed after the set time has elapsed from the start of the supply of the gas; and A gas supply control unit causes the processing device to supply the gas at the start timing determined by the gas supply determination unit.

2. The numerical control device according to claim 1, characterized in that: The numerical control device also has: A gas stop determination unit determines whether to stop the supply of the gas after the execution of the specific command is completed, based on the command subsequent to the specific command.

3. The numerical control device according to claim 1 or 2, characterized in that: The numerical control device further comprises: a movement standby setting unit which stops the relative movement between the machining head and the workpiece immediately before starting the machining; When the set time cannot be ensured before the specific command is executed, the gas supply determination unit calculates the insufficient time. The movement standby setting unit stops the relative movement between the machining head and the workpiece for the insufficient time.

4. The numerical control device according to any one of claims 1 to 3, characterized in that: The specific command is a command instructing the start of supply of the gas or the start of the process.

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