JP2018144192A - Device for regenerating cutting edge of cutting tool and method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for regenerating a cutting edge that detaches and removes weld deposit without damaging a tool by blasting dry ice to a tool surface with compressed air.SOLUTION: A device for regenerating a cutting edge of a cutting tool includes: a dry ice feeding part 12 for feeding dry ice to a cutting tool 7 where a processing material is deposited to a cutting edge and the cutting performance is deteriorated; an air compressor communicated to the dry ice feeding part 12 and feeding compressed-air for jetting dry ice; and a jetting nozzle 2 for blasting dry ice to a tool cutting edge.SELECTED DRAWING: Figure 4

Description

  In turning and turning, especially in dry processing and semi-dry processing that do not use cutting fluid, the cutting performance deteriorates due to welding of the work material to the tool cutting edge, but the tool cutting edge is not damaged. The present invention relates to a tool cutting edge regeneration device to which a function of blasting dry ice to the tool cutting edge is added in order to cleanly remove the welded material and regenerate cutting performance to a state close to a new product.

  Since aluminum and aluminum alloys are soft, there is a problem that when cutting is performed, a welded material gradually adheres to the cutting edge of the tool and becomes a constituent cutting edge, which deteriorates the processing surface. Further, when the processing is repeated while the welded material is generated, the welded material grows larger and spills together with a normal cutting edge when detaching, thereby shortening the tool life.

  The majority of techniques for suppressing the welding of the work material to the tool cutting edge is a method for optimizing the tool shape and improving the welding resistance (see References 1 to 3). In addition, as a method for removing the deposit adhered to the cutting edge of the tool and regenerating the cutting ability, a method of scraping and regenerating the deposit using a grindstone with a shaft (refer to Reference 4) or liquid metal embrittlement is applied. There is a method (refer to Document 5) in which the welded material is embrittled and scraped off.

  Further, at the processing site, the welded material is regenerated by dipping in an acidic or alkaline solution.

JP2013-193134A JP2007-245270 JP2003-25134

Satoshi Toyoda, Hirohito Yoshimura, Research on near-dry processing of aluminum alloys, 2015 Annual Meeting of Precision Engineering Annual Conference, (2015), p. p. 141-142 Tatsuya Sugihara, Toshiyuki Enomoto, On-machine regeneration of cutting tools with the aid of liquid metal embrittlement, Proceedings of the 2014 Annual Conference of Precision Engineering, (2014), p. p. 551-552

  However, although the cutting inserts of References 1 to 3 have a work material welding suppression effect, they do not consider reclaiming the welded material on the tool and regenerating the tool, so that once welding occurs, machining is performed. Repeating will eventually cause problems such as tool breakage and deterioration of the machined surface. Ultimately, a tool that has been damaged due to welding can only be discarded.

  In the reproduction method of Document 4, it is difficult to cope with various tool shapes, and further, when the grindstone is clogged, the removal effect is lowered. Further, the tool base material is wrinkled in the process of polishing the tool.

  Further, the regeneration method of Document 5 is complicated because there are a plurality of steps of embrittlement and removal of the welded material. Moreover, gallium used as a liquid metal is expensive.

  In addition, the regeneration method in which the tool is immersed in an acidic or alkaline liquid has problems in the working environment, wear of the tool base material, and safety.

  The problem to be solved by the present invention is that it can be easily added to an existing machine tool, the welded material can be easily removed from the tool cutting edge, and the tool base material is not wrinkled during the removal process. A blade regenerating apparatus and a tool cutting blade regenerating method are proposed.

  As a result of examining the above problems, the present invention has found that the problem can be solved by performing dry ice blasting on a tool to which a deposit is adhered, and the present invention has been completed based on this. That is, the invention claimed in the present application as means for solving the above problems, or at least the disclosed invention, is as follows.

[1] A dry ice supply device for supplying dry ice and dry ice communicated with the dry ice supply device are sprayed on a tool whose cutting ability is reduced by welding a work material to the cutting edge of the cutting tool. An apparatus for regenerating a cutting tool cutting edge by dry ice blasting, comprising an air compressor for supplying compressed air and a nozzle for blasting dry ice to the tool cutting edge.
[2] A cutting tool cutting blade regenerating apparatus by dry ice blasting according to [1], wherein the dry ice has a nozzle disposed at an angle of 5 to 40 ° with respect to the long axis direction of the tool.
[3] The dry ice blast according to [1] or [2], wherein the nozzle is disposed at a distance of 5 to 40 mm from the tool and blasts dry ice at an injection pressure of 0.2 to 0.8 MPa. Cutting tool cutting edge regeneration device by.
[4] The dry ice blast according to any one of [1] to [3], wherein the nozzle is attachable to and detachable from an existing machine tool by a magnet, and is attached at an arbitrary position that does not interfere with a machining space. Cutting tool cutting blade regenerator.
[5] The cutting tool cutting blade regenerating apparatus by dry ice blasting according to any one of [1] to [4], wherein a pointer is attached to the nozzle to determine a blast position.
[6] Regarding a tool whose cutting ability is reduced by welding the cutting material to the tool cutting edge by cutting using the dry tool blast cutting blade regenerating device according to any one of [1] to [5] A method for regenerating a tool cutting edge by dry ice blasting, wherein dry ice is blasted onto the tool to remove the deposit on the tool surface without damaging the tool cutting edge.
[7] The welded material on the surface of the tool is removed without damaging the tool cutting edge, and the difference in cutting resistance is regenerated to a state within 5% of the unused tool. Cutting tool cutting edge regeneration method.
[8] The processing material is not specified, but is particularly effective for aluminum and aluminum alloys.

  Since the tool regeneration method by welding removal of the present invention is configured as described above, according to this, the life of the tool in which welding, which was a problem of the prior art, is reduced, the processing surface is deteriorated, the tool is disposable, This is an invention that can eliminate the complexity of the tool regeneration procedure and the damage of the tool during the tool regeneration process.

It is the schematic which shows the tool reproduction | regeneration part in the machining center concerning embodiment of this invention. It is the schematic which shows the tool reproduction apparatus in the machining center concerning embodiment of this invention. It is the schematic which shows the tool reproduction | regeneration part in the lathe concerning embodiment of this invention. It is the schematic which shows the tool reproducing apparatus in the lathe concerning embodiment of this invention. It is a graph which shows the difference of the cutting resistance with respect to the unused tool in the experiment which the inventor of the present invention once performed, and the change of the surface roughness. It is a graph which shows the change of the processing distance and cutting resistance in the Example of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of a tool reproducing unit in a machining center according to an embodiment of the present invention. The tool reproducing apparatus is attached to the machining center as shown in FIG. This is a regenerator that removes the deposit and restores the cutting ability of the tool.
Of course, it can also be applied to machine tools other than machining centers. FIG. 3 shows a schematic diagram of a tool regenerating unit in a lathe according to an embodiment of the present invention, and FIG. 4 shows the tool regenerating apparatus. Tool regenerating is performed in the same manner as the machining center.
Hereinafter, a case of a machining center will be described as an example.

  When dry ice is blasted with compressed air, most of the deposits are removed by the impact. At this time, the welded material is easily peeled off due to a difference in thermal shrinkage from the tool due to a rapid local temperature drop of the welded material due to dry ice. The welded material on the tool surface is effectively removed by the above mechanism.

  As the blast material for the tool on which welding has occurred, any solid material having hardness suitable for shot blasting including sand and metal powder can be used without limitation. Dry ice is softer than any tool and does not damage the tool base material by blasting, and has the effect of cooling a tool that has become hot due to frictional heat or shearing heat during processing. In addition, after blasting, it sublimates into gas (carbon dioxide) and disappears, and the blasting material removal process after blasting is unnecessary, which is advantageous in that cleaning after the process is unnecessary. Therefore, the following description is limited to the case where dry ice is used as a blast material.

  1 is connected to the dry ice blasting device outside the machining center in FIG. 2 and the dry ice blasting device, and a blast hose 1 serving as a path for dry ice ejected from the dry ice blasting device, It is composed of an injection nozzle 2 which is a jet outlet, and a pointer 3 which indicates a blast position. The blast hose 1, the injection nozzle 2 and the positioning pointer 3 are drawn into the machining center, and the injection nozzle is fixed so that the dry ice 4 can be injected toward the cutting tool.

  In the cutting region 5 inside the machining center, the tool holder 6 mounted on the rotating spindle and the cutting tool 7 held by the tool holder 6 rotate, and the processing material 8 is removed. The machining material 8 is welded to the cutting edge of the cutting tool 7 by the removal process, and as the removal process proceeds, the welded material gradually grows, the cutting performance of the cutting edge is lowered, and the cutting resistance is increased.

  The cutting resistance during cutting is within the range where normal machining is performed if the difference in cutting resistance is within 5% of the unused tool. However, it has been found in the process of earnest research that the possibility of causing abnormal damage to the tool or deterioration of the machined surface is significantly increased if the machining is repeated with the welded material on the tool surface and the cutting resistance exceeds 5%. For example, FIG. 5 shows the result of machining aluminum alloy A6061 using a machining center. The cutting tool was a carbide square end mill with a diameter of 10 mm, and the cutting conditions were dry, with a cutting speed of 200 m / min, a feed speed of 400 mm / min, a cutting depth of 10 mm, and a cutting width of 2 mm. The cutting ability of the cutting tool was monitored by measuring the cutting resistance with a quartz piezoelectric three-component dynamometer. Therefore, in the following description, it is necessary to regenerate the tool by dry ice shot blasting, and the difference in the cutting resistance measured by the cutting dynamometer 11 attached to the existing machine tool 10 is 5 when the unused tool is used. Limited to when the percentage is exceeded. Since the cutting dynamometer is expensive, the cutting resistance may be evaluated by monitoring the spindle motor load attached to the machine tool 10.

  The reprocessing area 9 inside the machining center is located away from the processing material 8 so that the cutting tool 7 does not collide with the processing material 8 and is not damaged by the dry ice blast blown out for tool regeneration. It is a range. The cutting tool 7 whose cutting performance has deteriorated due to welding is moved from the cutting region 5 to the regeneration processing region 9, and dry ice sprayed from the spray nozzle 2 at a predetermined position is blasted to the cutting tool 7 so that the cutting tool is cut. Perform blade regeneration processing. The dry ice supply unit 12 may use any device as long as the injection pressure is 0.2 to 0.8 MPa.

  In the regeneration processing area, when the tool is moved to the blast position by the positioning pointer 3 attached to the injection nozzle 2, it can be visually confirmed.

  The injection nozzle 2 is placed at a position of 5 to 40 mm from the tool end point, and in the case of a machining center, blasting is performed while the tool is rotated. When the nozzle is located at a position less than 5 mm from the tool end point, there is a possibility that it will hit the tool, and there is a possibility that the range in which the blasted dry ice scatters is narrow and not blasted to the entire tool. When the nozzle is located at a position exceeding 40 mm from the end point of the tool, the blast pressure hitting the tool becomes small, and there is a possibility that welding removal will not be performed sufficiently. Therefore, the position of the nozzle is limited to a position of 5 to 40 mm from the tool end point.

  The injection nozzle 2 is oriented in a direction that forms an angle of 5 to 40 ° with respect to the long axis direction of the tool. This is because when the nozzle angle is less than 5 ° from the tool major axis direction, the impact of the blasted dry ice on the tool becomes weak and cannot be sufficiently removed. Further, when the nozzle angle exceeds 40 ° from the tool long axis direction, it collides from the tool rake face, so that the force to peel off the welded material becomes weak and the welded material cannot be removed sufficiently. Therefore, the nozzle angle used for dry ice blasting is limited to 5 to 40 ° from the tool longitudinal direction.

EXAMPLES Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited to this Example.
<1. Device>
A regenerating device using dry ice blasting having the structure shown in FIGS. In a machining center of a machine tool, an injection nozzle and a pointer are attached with a magnet at a position that does not interfere with the tool and the work material during machining and can be blasted to the tool.
<2. Processing conditions (Part 1)>
The machining of the aluminum alloy A6061 was performed using a machining center of a machine tool. The cutting tool was a carbide square end mill with a diameter of 10 mm, and the cutting conditions were dry, with a cutting speed of 200 m / min, a feed speed of 400 mm / min, a cutting depth of 10 mm, and a cutting width of 2 mm. The cutting ability of the cutting tool was monitored by measuring the cutting resistance with a quartz piezoelectric three-component dynamometer.

  FIG. 6 is a diagram showing changes in the machining distance and cutting resistance. The cutting force after the start of machining was 101N, but since the machining distance was 900m and the cutting resistance increased significantly to 158N (the difference in cutting resistance with respect to the unused tool 56.4%), the cutting process was interrupted and the machine tool In the inner regeneration range 14, regeneration processing by dry ice blasting was performed. While rotating the cutting tool at 120 rpm, a dry ice blast having a particle size of 10 to 50 μm was sprayed at a jetting pressure of 0.40 MPa for 30 seconds toward the cutting tool.

The tool after dry ice blasting is confirmed to have a difference of 5% or less (106.1 N or less) from the cutting resistance when not used, and the average machining surface using the unused tool Those having a roughness of 0.5 μm or less were considered to be regenerated.

  Examples 1-4 are examples based on the present invention. In either case, after the reprocessing, the machining tool was returned to the machining area 5 in the machine tool and the machining was resumed under the above cutting conditions. As a result, the difference in cutting resistance with respect to the unused tool was 5% or less. In addition, the machined surface roughness after machining 1800 m was 0.5 μm or less, and it was confirmed that the cutting ability of the cutting edge was regenerated. Moreover, as a result of observing the tool surface with a microscope, no traces of damage after blasting were observed.

  In comparisons 1 and 2, since the blasting distance was longer than 40 mm, the injection pressure was lowered, the welding was not sufficiently removed, and the processed surface roughness was increased.

  In comparison 3, since the blast angle was smaller than 5 ° and the impact of the blasted dry ice on the tool was weak, the welded material was not sufficiently removed, and the processed surface roughness was increased.

  In Comparative Example 4, the blast angle was larger than 40 °, and the force to peel off the welded material was weak, so that the welded material was not sufficiently removed and the processed surface roughness was increased.

<3. Processing conditions (2)>
2. As a result of this experiment, we were able to demonstrate some of the conditions that required the difference in cutting resistance to be within 5% of the unused tool and the surface roughness of the machined surface to be 0.5 μm or less. Based on these results, further confirmation experiments were recommended. In other words, with the blasting distance set to 20mm, the blasting angle set to 7 ° with respect to the tool longitudinal direction, and the tool rotated, using the machining center of the machine tool, each of the aluminum alloy, tool material and tool diameter of the work The tool regeneration effect under the conditions was evaluated based on cutting resistance and machined surface roughness after machining. Table 2 shows the conditions and measurement results in each example and comparative example.

  In each of Examples 1 to 8, the difference in cutting resistance after blasting is 5% or less with respect to an unused tool, and the target surface roughness after machining 1800 m is 0.5 μm or less. It was. Similarly, as a result of observing the tool surface with a microscope, no scars were observed after blasting.

DESCRIPTION OF SYMBOLS 1 Blast hose 2 Injection nozzle 3 Positioning pointer 4 Dry ice 5 Cutting process area 6 Tool holder 7 Cutting tool 8 Work material 9 Reprocessing area 10 Existing machine tool 11 Cutting dynamometer 12 Dry ice supply part

Claims (8)

A dry ice supply device that supplies dry ice and a compression for injecting dry ice that is communicated to the dry ice supply device for tools whose cutting ability is reduced due to the welding of the work material to the tool cutting edge in the cutting process A cutting tool cutting blade regenerating device using dry ice blasting, comprising an air compressor for supplying air and a nozzle for blasting dry ice to the tool cutting blade. 2. The cutting tool cutting blade regenerating apparatus by dry ice blasting according to claim 1, wherein the nozzle of the dry ice is disposed at an angle of 5 to 40 ° with respect to the major axis direction of the tool. 3. The cutting tool cutting edge by dry ice blasting according to claim 1, wherein the nozzle is disposed at a distance of 5 to 40 mm from the tool and blasts dry ice at an injection pressure of 0.2 to 0.8 MPa. Playback device. 4. The cutting tool cutting edge regeneration by dry ice blasting according to claim 1, wherein the nozzle is attachable to and detachable from an existing machine tool by a magnet and is attached at an arbitrary position that does not interfere with a machining space. apparatus. The cutting tool cutting edge regenerating apparatus by dry ice blasting according to any one of claims 1 to 4, wherein a pointer for determining a blast position is attached to the nozzle. Using the cutting tool cutting blade regenerating device by dry ice blasting according to any one of claims 1 to 5, with respect to the tool whose cutting ability is reduced by welding the work material to the tool cutting blade by cutting, the dry ice is A method for regenerating a tool cutting edge, comprising blasting a tool to remove a deposit on the surface of the tool without damaging the tool cutting edge. The dry ice according to claim 6, wherein the welded material on the surface of the tool is removed without damaging the cutting edge of the tool, and the difference in cutting resistance is regenerated to within 5% of the unused tool. Cutting tool cutting edge regeneration method by blasting. The method for regenerating a tool cutting edge according to claim 6 or 7, wherein the work material is aluminum or an aluminum alloy.