JP4363343B2 - Processing condition setting method and processing apparatus - Google Patents

Description

  The present invention relates to a machining condition setting method for setting a machining condition of a machining apparatus for attaching a tool to a spindle via a holder, and a machining apparatus using the machining condition setting method.

  In cutting of a die or the like, tooling (a combination of a tool and a holder) used in accordance with a workpiece shape changes in a complicated manner. Specifically, in the die machining, cutting is performed while exchanging about 30 types of tools, and the holder for holding the tool is selected in consideration of the machining site. For example, as shown in FIG. 5 (A), when forming a recess having an upright wall of the workpiece W with the tool 12a, a cylindrical holder 14a is combined, and as shown in FIG. 5 (B), the workpiece W When the concave portion having the inclined wall is formed, the truncated cone-shaped holder 14b is inferior in rigidity, but the tool protrusion amount is set shorter than the case where the cylindrical holder is used, and the entire tool / holder is Take measures to increase rigidity. Further, as shown in FIG. 5C, a small diameter tool 12c is used to select a small diameter tool standard diameter holder 14c when machining a narrow portion. When cutting a relatively wide portion as shown in FIG. 5D, a large-diameter holder 14d having high rigidity is combined.

  Here, the machining conditions (spindle speed, cutting amount, pick feed amount, tool feed speed) are selected in consideration of the tooling described above (combination of tool and holder), machine used, cutting edge shape, and protrusion. It is necessary to consider the amount (projection length of the tool from the holder), the material of the workpiece, roughing, intermediate finishing, finishing, etc., and high skill is required.

Setting processing conditions using a computer has been put into practical use. This automatic setting will be described with reference to FIG.
First, the tool type, the type of the holder attached to the tool, the protruding amount, the workpiece, and the processing method are input to the computer (S202). Here, it is assumed that 30 tools, holders attached to the respective tools, and protrusion amounts of the respective tools are input by the operator. In response to this, the computer selects a tool to be processed (S204). Then, the processing condition database is searched from the input conditions for the processing target tool, and the processing conditions (spindle rotation speed, cutting amount, pick field amount, feed speed) are determined (S206). Here, the machining condition database is constructed based on basic machining tests, and the machining condition database is searched by tool type (number of cutting edges, cutting edge shape, material), holder type, work material, etc. To obtain the processing conditions. Then, it is determined whether or not the process of S206 has been completed for all the tools (S208). If the process has not been completed (S208: No), the process returns to S204, and the next processing target tool is selected. Then, the processing condition determination processing in S206 is performed. And if the said process is completed with respect to all 30 tools (S208: Yes), a process will be complete | finished.

Cited Document 1 describes a machining condition determination program for setting machining conditions by key input. Cited Document 2 describes a cutting method for improving machining efficiency. Cited Document 3 describes a cutting method for suppressing vibration generated by a tool.
JP-A-7-1286 Japanese Patent Laid-Open No. 11-300517 JP 2000-263308 A

However, in order to set the machining conditions, it is necessary to examine past cases and tool catalog values, which takes a long time. Further, even if the process is performed for a long time, the method of setting the machining conditions differs depending on the operator. If the safety is emphasized, the machining time becomes longer than necessary, and if the machining time is emphasized, the machining accuracy is lowered.
At present, it is becoming difficult to use the speed of the processing machine and to fully use the performance of the increased processing machine only by knowledge and experience with a conventional low-speed machine.
Furthermore, even if the above-described processing conditions are automatically set, only a rough setting can be made as compared with a human setting, and the processing time is unnecessarily longer or the processing accuracy is lowered.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a machining condition setting method and a machining apparatus capable of performing machining in a short time using a high speed machine. It is in.

In order to achieve the above object, the invention of claim 1 is a machining condition setting method for setting machining conditions of a machining apparatus MC1 for machining a workpiece by attaching a tool 12a to a spindle 16a via a holder 14b.
Feed speed of the tool for machining a workpiece, the pick feed rate, depth of cut, a step (S102) of inputting the tentative machining conditions comprising at least one spindle speed,
Tool, a step (S102) to enter the information of the holder, for holding or input information of the main shaft,
A step of determining the rigidity of the tool system composed of the tool, the holder, and the spindle by structural analysis based on the shape data of the tool / holder / machine and the material data of the tool / holder / machine (S108) ;
When the rigidity of the tool system is lower than the required rigidity, the provisional machining condition is corrected by correcting the tool feed speed, and the required rigidity required for machining is reduced (S112) ;
The natural frequency of the tooling consisting of the holder and the tool is obtained, the resonance rotational speed of the tooling is obtained from the natural frequency, and the spindle rotational speed is corrected when the resonant rotational speed and the spindle rotational speed are approximated. And steps to
When the natural frequency of the tool system consisting of the spindle, the holder, and the tool is obtained, the resonance rotational speed of the tool system is obtained from the natural frequency, and the resonance rotational speed and the spindle rotational speed are approximated. And a step of correcting the rotational speed of the spindle .

The machining apparatus according to claim 2 includes a drive device MC1 that relatively moves a tool 12a attached to the spindle 16a via a holder 14b and a workpiece, and a control device 20 that controls the drive device MC1. In
The control device includes a machining condition input means for inputting a provisional machining condition including at least one of a feed speed of the tool for machining a workpiece and a spindle rotation speed to the control device ;
Tool, the information of the holder is inputted to the control unit, and the tool system information input means for inputting to hold or control information of the spindle by the control device,
Analysis means for obtaining the rigidity of a tool system composed of a tool, a holder, and a spindle by structural analysis based on tool / holder / machine shape data and tool / holder / machine material data ;
When the rigidity of the tool system is lower than the required rigidity, the provisional processing conditions are corrected by correcting the tool feed speed, and the rigidity adjusting means for reducing the required rigidity required when processing,
The natural frequency of the tooling consisting of the holder and the tool is obtained, the resonance rotational speed of the tooling is obtained from the natural frequency, and the spindle rotational speed is corrected when the resonant rotational speed and the spindle rotational speed are approximated. First spindle rotation speed adjusting means,
When the natural frequency of the tool system consisting of the spindle, the holder, and the tool is obtained, the resonance rotational speed of the tool system is obtained from the natural frequency, and the resonance rotational speed and the spindle rotational speed are approximated. A second spindle speed adjusting means for correcting the spindle speed;
A technical feature is that the driving device is controlled based on the machining conditions corrected by the rigidity adjusting means, the first spindle rotation speed adjusting means, and the second spindle rotation speed adjusting means .

According to the first and second aspects of the present invention, the rigidity of at least one of the spindle, the holder, and the tool is analyzed, and if the rigidity is lower than that required for the input provisional machining conditions, the provisional machining conditions are corrected. For example, when the rigidity of the tool is lower than the rigidity required for the feed amount and feed speed of the tool under the temporary machining conditions, at least one of the feed amount and feed speed of the tool is reduced. For this reason, it is possible to avoid the bending of the tool due to insufficient rigidity that lowers the machining accuracy.

The invention of claim 1 analyzes the rigidity of at least one of the spindle, the holder, and the tool. For example, when the rigidity of the tool is lower than the rigidity required at the feed speed of the tool under the temporary machining conditions, Reduce the feed amount. For this reason, it is possible to avoid the bending of the tool due to insufficient rigidity that lowers the machining accuracy.

In claim 1 , the resonance rotational speed of the tooling is obtained from the information of the holder and the tool, the spindle rotational speed under the provisional machining conditions is compared with the resonant rotational speed of the tooling, and the rotational speed of the spindle and the resonant rotational speed of the tooling are determined. When approximating, change the rotation speed of the spindle. For example, when the rotational speed is within a range obtained in advance from the resonance rotational speed of the tooling, the rotational speed of the main shaft is lowered. For this reason, it is possible to avoid tooling vibrations that reduce machining accuracy.

According to the first aspect of the present invention, the natural frequency of the tool system is obtained from the information on the spindle, the holder and the tool, the resonance speed of the tool system is obtained from the natural frequency, and the spindle speed and the tool system under the temporary machining conditions are obtained. The rotation speed of the main shaft is changed when the rotation speed of the main shaft and the resonance rotation speed of the tool system approximate to each other. For example, when the rotational speed is within a range obtained in advance from the resonant rotational speed of the tool system, the rotational speed of the main shaft is lowered. For this reason, it becomes possible to perform machining at a high rotational speed in a short time without causing problems such as bearing seizure due to resonance of the main shaft.

[First embodiment]
FIG. 1 shows a configuration of a machining condition setting method and a machining apparatus using the machining condition setting method according to the first embodiment of the present invention.
The computer 20 automatically sets machining conditions for the two types of machining apparatuses MC1 and MC2 and creates NC data. A hard disk 21 that holds a database for setting processing conditions is connected to the computer 20. The NC data is held in the CNC control devices CNC1 and CNC2, and controls the machining devices MC1 and MC2. The processing devices MC1 and MC2 are provided with tool changers P1 and P2 for holding a plurality of holders to which tools are attached.

  2A shows the main shaft 16a of the machining apparatus MC1, and FIGS. 2B and 2C show the main shaft 16b of the machining apparatus MC2. Here, the main shaft 16b of the processing device MC2 is thicker than the main shaft 16a of the processing device MC1. Even when the same tool 12a and holder 14b shown in FIGS. 2 (A) and 2 (B) are used, the machining device MC2 having a thick spindle sets a higher machining efficiency (cut amount × pick field amount × feed speed). be able to. Therefore, in the machining condition setting method of the first embodiment, in such a case, the machining time is shortened by setting a higher machining efficiency to the machining device MC2 having a thick spindle.

  FIG. 2B shows a state in which the medium-sized tool 12a is attached to the machining apparatus MC2, and FIG. 2C shows a state in which a large tool 12e is attached to the same machining apparatus MC2. In the example where the large tool 12e having a high inertia weight shown in FIG. 2C is attached, the spindle may be damaged if the rotational speed is high. For this reason, in the machining condition setting method of the first embodiment, when the large tool 12e is attached, the number of revolutions of the spindle is reduced, the cutting amount, the pick field amount, and the feed are lower than when the medium tool 12a is attached. Increasing the speed minimizes the increase in machining time while preventing damage to the spindle.

Next, specific processing of the machining condition setting method of the first embodiment will be described with reference to the flowchart of FIG.
First, processing condition data (feed speed for each tool, pick feed amount, cutting amount, spindle rotational speed, etc.) set in the computer 20 by the setting method of the conventional processing conditions described above with reference to FIG. Input as "temporary machining condition data" and the basis of which the "temporary machining condition data" is created, the type of tool, the type of holder attached to the tool, the amount of protrusion, the workpiece, A machine to be used (that is, any one of the processing device MC1 and the processing device MC2 shown in FIG. 1) and a processing method are input (S102). Here, the operator inputs 30 tools, holders attached to the respective tools, and protrusion amounts of the respective tools, selects the processing device MC1, and according to this, the processing condition data has already been stored. It is assumed that it has been created.

  In response to the input of “temporary machining condition data”, a tool to be processed is selected (S106). Here, it is assumed that the tool 12a shown in FIG. Then, the rigidity of the tool system composed of the tool, the holder, and the spindle is obtained from the tool / holder / machine information database in the hard disk 21 based on the tool / holder / machine shape data and the tool / holder / machine material data. The tool system is obtained by structural analysis (S108). Here, the tool / holder / machine information database is constructed based on basic machining tests.

  Then, it is determined whether the determined rigidity of the tool system is greater than the required rigidity required when machining under temporary machining conditions (spindle rotation speed, cutting amount, pick field amount, feed rate) (S110). Here, when the rigidity of the tool system is lower than the required rigidity (S110: No), the provisional machining conditions are corrected and the required rigidity required for machining is lowered (S112).

  Subsequently, the vibration mode of the entire spindle (spindle, holder, tool) with the tool and holder attached is obtained by structural analysis based on the above-described tool / holder / machine information database (S114). For example, the natural frequency of a tool system including a spindle, a holder, and a tool is obtained, and the resonance rotational speed of the tool system is obtained from the natural frequency. The spindle speed set in the provisional machining conditions is within a predetermined percentage above and below the vibration frequency of the entire spindle (or the resonance frequency of the tool system), that is, within the range in which vibration due to the resonance phenomenon occurs in the vibration mode (critical rotation). Speed) is determined (S116). When the main shaft rotation speed is the critical rotation speed (S116: Yes), the main shaft rotation speed is decreased until the occurrence of resonance vibration can be avoided (S118).

  Further, the vibration mode of the tool and the holder (tooling) is obtained based on the above-described tool / holder / machine information database (S120). For example, the natural frequency of tooling composed of a holder and a tool is obtained, and the resonance rotational speed of the tooling is obtained from the natural frequency. The spindle rotational speed set in the provisional machining conditions or the spindle rotational speed changed in S118 is within a predetermined upper and lower parts of the vibration frequency (or resonance rotational speed) of the tool and the holder, that is, vibration due to a resonance phenomenon in the vibration mode. It is determined whether it is within a range (processing chatter speed) (S122). When the spindle rotational speed is the machining chatter speed (S122: Yes), the spindle rotational speed is decreased until the occurrence of resonance vibration can be avoided (S124).

  It is determined whether or not the processing of S108 to S124 has been completed for all the tools (S126). If the processing has not been completed (S126: No), the process returns to S106 and the next processing target tool is selected. , S108 to S124 are performed. When the above process is completed for all 30 tools (S126: Yes), NC data for the machining apparatus MC1 shown in FIG. 1 is created under the set machining conditions (S128), and the process ends. The created NC data is transferred to the CNC control device CNC1 of the machining device MC1 and used for controlling the machining device MC1.

  In the machining apparatus using the machining condition setting method and the machining condition setting method of the first embodiment, when the rotation speed of the spindle causes the machining apparatus to resonate, a high speed machine is used to change the rotation speed of the spindle. However, it is possible to perform machining in a short time at a high spindle rotational speed without causing problems such as bearing seizure due to resonance of the spindle. Moreover, the vibration of the tool that reduces the machining accuracy can be avoided.

  Furthermore, in the first embodiment, since the rigidity of the tool is analyzed and the determined feed amount and feed speed of the tool are corrected according to the rigidity of the tool, the bending of the tool due to the lack of rigidity that reduces the machining accuracy is avoided. be able to. For this reason, it becomes possible to use the performance of the speeded-up processing apparatus and complete the processing in a short time while preventing the occurrence of a failure and avoiding the deterioration of the processing accuracy.

  In the first embodiment, the processing conditions for processing at high speed are automatically determined, and the shortest processing time can be set without reducing the processing accuracy, so that productivity can be improved. Needless to say, the time for setting the processing conditions can be shortened.

[Second Embodiment]
With reference to FIG. 4, the structure of the processing apparatus which uses the processing condition setting method and processing condition setting method which concern on 2nd Embodiment of this invention is shown.
In the first embodiment described above with reference to FIG. 1, the computer 20 creates NC data for a plurality of machining apparatuses. In contrast, in the second embodiment, a dedicated NC data creation computer 20 is provided in one machining apparatus MC1. That is, in the second embodiment, the CNC control device determines the machining conditions as in the first embodiment. In the second embodiment, since information unique to the processing device MC1 such as the spindle diameter is set in the computer 20, the tool type, the type of the holder attached to the tool, the protrusion amount, and the workpiece are input. As a result, NC data can be created by setting the machining conditions as in the first embodiment.

  In the embodiment described above, the die machining by the machining apparatus has been described as an example, but it goes without saying that the machining apparatus using the machining condition setting method and the machining condition setting method of the present invention can be applied to various machining. Yes.

It is a block diagram which shows the structure of the processing apparatus by the processing condition setting method which concerns on 1st Embodiment of this invention. 2A shows the main shaft 16a of the machining apparatus MC1, and FIGS. 2B and 2C show the main shaft 16b of the machining apparatus MC2. It is a flowchart which shows the process by the processing condition setting method which concerns on 1st Embodiment. It is a block diagram which shows the structure of the processing apparatus by the processing condition setting method which concerns on 2nd Embodiment of this invention. It is explanatory drawing which shows the example of a combination of a tool and a holder. It is a flowchart which shows the process by the processing condition setting method which concerns on a prior art.

Explanation of symbols

12a, 12b Tool 14a, 14b Holder 16a, 16b Spindle 20 Computer 21 Hard disk (database)
MC1, MC2 processing equipment

Claims (2)

In a machining condition setting method for setting a machining condition of a machining apparatus for machining a workpiece by attaching a tool to a spindle via a holder, using a computer ,
Inputting a provisional machining condition comprising at least one of a feed speed of the tool for machining a workpiece and a spindle rotation speed to a computer ;
Tool, comprising: information of the holder and input to the computer, to enter into the holding or computer information of the spindle in the computer,
Obtaining rigidity of a tool system composed of a tool, a holder, and a spindle by structural analysis based on tool / holder / machine shape data and tool / holder / machine material data; and
When the rigidity of the tool system is lower than the required rigidity, the provisional machining conditions are corrected by correcting the tool feed speed, and the required rigidity required for machining is reduced, and
The natural frequency of the tooling consisting of the holder and the tool is obtained, the resonance rotational speed of the tooling is obtained from the natural frequency, and the spindle rotational speed is corrected when the resonant rotational speed and the spindle rotational speed are approximated. And steps to
When the natural frequency of the tool system consisting of the spindle, the holder, and the tool is obtained, the resonance rotational speed of the tool system is obtained from the natural frequency, and the resonance rotational speed and the spindle rotational speed are approximated. And a step of correcting the spindle rotational speed . In a machining apparatus provided with a drive device that relatively moves a tool attached to a spindle via a holder and a workpiece, and a control device that controls the drive device,
The controller is
Machining condition input means for inputting provisional machining conditions consisting of at least one of a feed speed of the tool and a spindle rotation number for machining a workpiece to the control device ;
Tool, the information of the holder is inputted to the control unit, and the tool system information input means for inputting to hold or control information of the spindle by the control device,
Analysis means for obtaining the rigidity of a tool system composed of a tool, a holder, and a spindle by structural analysis based on tool / holder / machine shape data and tool / holder / machine material data ;
When the rigidity of the tool system is lower than the required rigidity, the provisional processing conditions are corrected by correcting the tool feed speed, and the rigidity adjusting means for reducing the required rigidity required when processing,
The natural frequency of the tooling consisting of the holder and the tool is obtained, the resonance rotational speed of the tooling is obtained from the natural frequency, and the spindle rotational speed is corrected when the resonant rotational speed and the spindle rotational speed are approximated. First spindle rotation speed adjusting means,
When the natural frequency of the tool system consisting of the spindle, the holder, and the tool is obtained, the resonance rotational speed of the tool system is obtained from the natural frequency, and the resonance rotational speed and the spindle rotational speed are approximated. A second spindle speed adjusting means for correcting the spindle speed;
A machining apparatus, characterized in that the drive device is controlled based on machining conditions corrected by the rigidity adjusting means, the first spindle rotation speed adjusting means, and the second spindle rotation speed adjusting means .

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