JP2007249923A - Nc machining facility and workpiece machining method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an NC machining facility and a workpiece machining method using the NC machining facility preventing the degradation of production efficiency by easily setting machining conditions such as spindle rotating speed and feed speed suitable for a tool in use in the field even if material and the state of the tool change. <P>SOLUTION: The NC machining facility equipped with a plurality of tools is provided with a plurality of override value setting means 1, 2, 3, 4, and a control means for automatically selecting the override value setting means utilized according to the tool in use or a code in an NC program. Machining is carried out while changing the override value setting means utilized according to the tool in use. The override value can thereby be automatically changed according to the tool to improve production efficiency and to reduce a field operator's burden. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an NC processing facility including a plurality of tools and a workpiece processing method using the NC processing facility.

  NC machining equipment provided with a plurality of tools represented by machining centers is widely used, and workpieces can be automatically machined with a tool designated according to the NC program. In addition to the types of tools, the NC program encodes the spindle speed, tool feed speed, coordinate points to be machined, etc., using the specified tool, and cutting and drilling under specified processing conditions. Can be processed easily.

  In addition, as a kind of NC processing equipment equipped with a plurality of tools, an inner and outer diameter cutting device of a soot tube can be raised. In this apparatus, the inner and outer diameters are cut by an inner diameter cutting means and an outer diameter cutting means while holding a ceramic material vertically on a main shaft and rotated by a main shaft rotating motor, and formed into a predetermined shape. One example is described in Patent Document 1 of the present applicant, and cutting is performed while the inner diameter cutting bit and the outer diameter cutting bit are moved in the axial direction and the radial direction by NC control.

  These NC machining facilities machine the workpiece at the programmed spindle speed and feed rate, but there are times when you want to change the machining conditions while watching the machining status of the workpiece on site. Therefore, the NC processing equipment is provided with an override knob for adjusting the spindle speed and an override knob for adjusting the feed speed. For example, if the override knob for adjusting the spindle speed is set to 90%, 90% of the programmed spindle speed It was possible to perform processing at a rotational speed of. However, in this case, the spindle rotational speed is reduced to 90% for all the tools, so that the production efficiency is lowered.

  For example, in the case of an inner and outer diameter cutting device for a steel pipe, the hardness of the ceramic material that is the workpiece is likely to change due to the dry state in the previous process and the difference in raw material lots. However, by operating the override knob, the rotational speed of the spindle is reduced to about 90% of the programmed setting rotational speed to perform cutting. In this case, both the inner diameter cutting speed and the outer diameter cutting speed are reduced to 90% of the set value.

  However, the inner diameter cutting bit is provided at the tip of a long inner diameter cutting shaft so that it can be inserted into the inner surface of the workpiece, whereas the outer diameter cutting bit is not necessary. The override value suitable for inner diameter cutting may not match the override value suitable for outer diameter cutting because the tool holding means are greatly different and the dry state is not necessarily the same between the inner and outer surfaces of the workpiece. . In such a case, if the override value on the side where the rotational speed is high is selected, the product skin may be rough and become a defective product. Therefore, the override value has always been set to the low side for safety reasons. As a result, the surface that can be cut at a higher speed is cut at a lower speed, resulting in a problem that the cutting time becomes longer and the production efficiency is lowered.

Also, as the cutting tool used wears and the cutting force changes, the optimum cutting conditions also change.Therefore, the cutting conditions are determined by the cutting tool used (outer diameter roughing cutting tool, outer finishing cutting tool, inner diameter cutting tool). It may change. Especially when the cutting force is small, even if the feed rate is increased and the cutting amount is increased, the problem of runout does not occur. May be shortened. However, this requires frequent operation of the override pick by field workers.
Japanese Patent Publication No. 5-35644

  The present invention solves the above-mentioned conventional problems, and machining conditions such as spindle rotation speed and feed speed suitable for the tool to be used even when the material or the state of the tool changes can be easily set on the production site. It was made in order to provide the NC processing equipment which can prevent the fall of efficiency, and the processing method of the workpiece | work using the same.

  The NC machining equipment of the present invention made to solve the above problems is an NC machining equipment having a plurality of tools, and is used by a plurality of override value setting means and a tool to be used or a code in the NC program. Means for automatically selecting an override value setting means to be provided. It is preferable that a plurality of override set value setting means are provided for each or one of the spindle speed and the feed rate. In a preferred embodiment, the NC processing facility is an inner / outer diameter cutting device for a hollow tube, and the plurality of tools are an inner diameter cutting tool and an outer diameter cutting tool.

  The workpiece machining method using the NC machining equipment according to the present invention uses the NC machining equipment according to claim 1 and sets an override value for each of a plurality of override value setting means, and an override value setting means used by a tool. It is characterized by processing using a plurality of tools while automatically selecting. In this case, the override value setting means can be automatically selected according to the code specified in the NC program.

  According to the present invention, the NC machining facility is provided with a plurality of override value setting means, and the machining is performed while automatically selecting the override value setting means to be used depending on the tool to be used. While observing, machining conditions such as spindle rotation speed and feed speed according to the tool to be used can be easily set without correcting the NC program. Therefore, productivity can be improved compared to the conventional case where the same override value is used for all tools. Further, it is not necessary for the site worker to frequently operate the override value setting means, and the burden on the site worker can be reduced.

  FIG. 1 and FIG. 2 show a first embodiment in which the present invention is applied to a machining center. An operation panel 1 has two override value setting means 2 and 3 for a spindle and two feed values for feeding. Override value setting means 4 and 5 are provided. The NC program encodes the tool to be used, the spindle speed, the feed speed, and the coordinates to be machined. In this embodiment, in addition to this, the spindle speed and feed speed are set according to the setting value of which override value setting means. Whether to adjust is specified in the NC program and the override value setting means to be used is automatically selected according to the tool number.

  For example, the override value setting means 2 and the override value setting means 4 are used for the No. 1 tool, and the override value setting means 3 and the override value setting means 5 are used for the No. 2 tool. Keep it. If the override value setting means 2, 3, 4 and 5 are set with an override value of plus 10%, minus 10%, plus 20%, minus 20%, the spindle speed is programmed when machining with the No. 1 tool. The feed speed is increased by 20%. When machining with a No. 2 tool, the spindle speed is minus 10% of the programmed value, and the feed rate is minus 20%.

  If machining is performed by changing the override value setting means used depending on the tool used in this way, productivity can be improved over the conventional machining method using the same override value for any tool. In addition, the burden on workers can be reduced. In addition to the method of coding which override value setting means to use together with the tool number in the NC program, it is possible to set in advance which override value setting means will be used according to the selected tool number. It can also be made hardware. Note that the override value may be set by the operator's picking operation, but it may also be set by software from the keyboard on the NC control panel as in the case of setting the tool length correction. This also has the advantage that the override value can be set in detail.

  FIGS. 3 and 4 show a second embodiment in which the present invention is applied to an inside / outside diameter cutting device for a soot pipe, 11 is a base, and 12 is a potter's wheel spindle on which a ceramic material as a work W is placed and rotated. is there. In this embodiment, the workpiece W is a ceramic material with moisture fluctuation. Since the workpiece W is long, a rotatable holder 3 is also provided on the upper side, and is rotated while being held up and down by the holder 13 and the main shaft 12. Reference numeral 14 denotes a spindle rotating motor that rotates the spindle 12, and the number of rotations is set by an NC program.

  Reference numeral 15 denotes an inner diameter cutting means for cutting the outer peripheral surface of the workpiece W. The inner diameter cutting means 15 includes an inner diameter cutting tool 17 that can move up and down along a vertical guide 16 provided on the upper portion of the base 11 and can also move in the radial direction of the workpiece W. The inner diameter cutting tool 17 is driven by NC control to cut the outer peripheral surface of the workpiece W into a desired shape. In the case of a saddle pipe, since many shades are formed on the outer peripheral surface, it is common to perform roughing and finishing while automatically exchanging the cutting tool on the way.

  Reference numeral 18 denotes an outer diameter cutting means for cutting the inner peripheral surface of the workpiece W. The outer diameter cutting means 18 is also provided with an outer diameter cutting tool 20 that can move up and down along a vertical guide 19 provided at the lower portion of the base 11 and can also move in the radial direction of the workpiece W. However, the outer diameter cutting tool 20 is supported at the tip of the long post 21 so that it can be inserted into the workpiece W from the center hole of the main shaft 12. The outer diameter cutting tool 20 is also driven by NC control to cut the inner peripheral surface of the workpiece W into a desired shape.

  The number of revolutions of the spindle rotating motor 14 is set by an NC program. For example, it is set to 70 rpm during inner diameter cutting and 300 rpm during outer diameter cutting. The reason why the set rotational speed is different is that the distance from the rotation axis to the cutting point is different, and the holding rigidity is different between the inner diameter cutting bit 17 and the outer diameter cutting bit 20.

  This set rotational speed is constant for each product number, but as described above, the ceramic material that is the workpiece W is easily changed in hardness due to the dry state in the previous process or the difference in the raw material lot, and is programmed depending on the state of the workpiece. When cutting at the set rotation speed, the skin may become rough or run out. Therefore, in the present invention, the inner diameter cutting override value setting means 22 and the outer diameter cutting override value setting means 23 are individually provided so that the rotational speed of the main shaft 12 can be adjusted in the field.

  The inner diameter cutting override value setting means 22 is capable of adjusting an override value for the inner diameter cutting set rotational speed set by the program. Similarly, the outer diameter cutting override value setting means 23 can adjust the override value for the outer diameter cutting set rotational speed set by the program. As shown in FIG. 4, the rotation speed obtained by multiplying the set rotation speed by the respective override value becomes the actual rotation speed output, and the spindle rotating motor 4 rotates the workpiece W with the actual rotation speed output.

  In this way, since the conventional override value setting means was made plural, it was possible to select different override values for inner diameter cutting and outer diameter cutting. The override value can be set low, the override value at the inner diameter cutting can be set low, and the override value at the outer diameter cutting can be set high. Accordingly, the respective rotation speeds suitable for the inner diameter cutting and the outer diameter cutting can be easily set in the field according to the state of the material, and the reduction in productivity can be prevented.

  As shown in FIG. 2, it is determined from the command code in the NC program whether the current cutting is the inner or outer surface, the override value of the inner diameter cutting override value setting means 22 is selected when cutting the inner surface, and the outer value is selected when cutting the outer surface. It is preferable to select an override value of the radius cutting override value setting means 23. The range of the override value is usually about 10 to 200%. As the instruction code, in addition to defining a special instruction code, it can be dealt with by using a tool change command.

  In the above description, the inner diameter cutting override value setting means 12 and the outer diameter cutting override value setting means 13 are provided. However, both the inner diameter cutting and the outer diameter cutting are often performed in two steps, rough cutting and finishing cutting. Therefore, a rough cutting override value setting unit and a finishing cutting override value setting unit may be additionally provided to enable finer adjustment.

  Using the molding machine shown in FIG. 1, a 3 m high soot tube was molded. Cutting is performed in three stages of an inner diameter, an outer diameter, and an inner diameter, and the rotation speeds set by the NC program are 70 rpm, 300 rpm, and 60 rpm, respectively. When a harder material came, cutting was performed with an inner diameter cutting override value of 90%, an outer diameter cutting override value of 120%, and an actual rotational speed of 63 rpm, 360 rpm, and 54 rpm.

  As a result, a beautifully finished skin tube was formed. Moreover, the total production efficiency was maintained at 100%. On the other hand, since there is conventionally only one override value setting means, if the operator forgets to change the override value during outer diameter machining while the override value during inner diameter machining is set to 90%, outer diameter cutting is performed. The total production efficiency was reduced to 90%.

It is a perspective view which shows the machining center of the 1st Embodiment of this invention. It is explanatory drawing of the operating panel of a machining center. It is a fragmentary sectional view showing the 2nd embodiment of the present invention. It is a control block diagram.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Operation panel 2 Override value setting means 3 Override value setting means 4 Override value setting means 5 Override value setting means 11 Base 12 Spindle 13 Holder 14 Spindle rotation motor 15 Inner diameter cutting means 16 Vertical guide 17 Inner diameter cutting bit 18 Outer diameter Cutting means 19 Vertical guide 20 Outer diameter cutting bit 21 Long post 22 Inner diameter cutting override value setting means 23 Outer diameter cutting override value setting means

Claims (4)

  NC machining equipment having a plurality of tools, characterized by comprising a plurality of override value setting means and means for automatically selecting the override value setting means according to the tool to be used or a code in the NC program NC processing equipment.   2. The NC machining equipment according to claim 1, wherein a plurality of override value setting means are provided for each or one of the spindle rotational speed and the feed speed.   2. The NC processing equipment according to claim 1, wherein the NC processing equipment is an inner and outer diameter cutting device for a hollow tube, and the plurality of tools are an inner diameter cutting tool and an outer diameter cutting tool.   A workpiece machining method using the NC machining equipment according to claim 1, wherein an override value is set in each of a plurality of override value setting means, and an override value setting means used by a code in a tool or NC program is automatically used. A workpiece machining method using NC machining equipment, characterized by machining with multiple tools while selecting the target.

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