JP7303610B2 - cutting equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a cutting apparatus capable of appropriately processing continuous chips.

Machine parts and the like that require precision are cut products obtained by cutting work materials such as castings and metal materials. In order to ensure the quality and accuracy of cut products, it is important to dispose of chips generated from the work material during cutting. Inappropriate chip disposal may result in poor machining in which the desired surface roughness and accuracy cannot be obtained, or may lead to a decrease in machining efficiency and tool life. In particular, long connected chips (referred to as "continuous chips" in this specification) are entangled with the work material (work) or cutting tool (chip), etc. can be a factor.

Such continuous chips are likely to occur in turning, which is a type of cutting. Therefore, in turning, conventionally, a cutting tool (tip) equipped with a chip breaker (protrusions or the like provided on the rake face) for breaking continuous chips is used.

However, since continuous chips generated during finishing machining with a small depth of cut or feed are thin, they are difficult to break with the chip breaker. In other words, the machining conditions for which the chip breaker is effective are limited, and the chip breaker is not effective for finishing machining that requires high quality or high precision. Therefore, the following patent documents have proposed a chip treatment method in which chips generated during turning are sucked and removed from the machining point.

JP 2004-58244 A JP 2010-247271 A

Both Patent Documents 1 and 2 propose providing a duct (a chip scattering prevention cover, a chip suction holder) for collecting and sucking chips above the cutting tool (tip). However, Patent Document 1 and the like describe cases in which cut chips are naturally generated during finishing processing, such as when machining a commutator (work material) in which commutator bars and insulating bars are alternately arranged. It is assumed. For this reason, in Patent Literatures 1 and 2, although the passage area is reduced from the middle, collection using a dust collector (suction pump) is possible.

However, the continuous chips tend to stay in a narrow portion in the middle of the passage, clogging the passage, and there is a possibility that the continuous chips may flow back from there. Therefore, devices such as those disclosed in Patent Documents 1 and 2 cannot stably discharge continuous chips.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cutting apparatus capable of accurately discharging continuous chips and stably performing high-quality cutting.

As a result of intensive research aimed at solving this problem, the present inventor conceived of a new guideway suitable for discharging continuous chips. By embodying and developing this idea, the present invention described below has been completed.

《Cutting device》
(1) The present invention provides a cutting tool having a cutting edge for cutting a work material and a rake face that continues to the rear of the cutting edge; a guide path for taking in continuous chips from an inlet provided on the cutting edge side and guiding the continuous chips to an outlet provided on the rear side of the rake face, the passage cross-sectional area of the guide path being from the inlet to the guide; A constant or increasing cutting device up to the exit.

(2) In the cutting apparatus of the present invention, the passage of the guide path from the inlet to the outlet has a certain size or more. Therefore, the continuous chips taken in from the inlet can be stably guided to the outlet without staying or clogging in the middle of the guide path. In addition, chips which are in a softened state at a high temperature and come into contact with the wall surface of the guideway are easily corrected into a shape that is easy to discharge.

In this way, according to the cutting apparatus of the present invention, even during finish machining in which thin continuous chips are likely to be generated, chip disposal can be performed accurately, and high-quality cut products can be stably obtained. Since the cutting apparatus of the present invention can process continuous chips, it can naturally process cut chips.

"others"
(1) In this specification, for convenience of explanation, the cutting edge side or inlet side is referred to as "front", and the trailing edge side (opposite side of the cutting edge) or outlet side of the rake face is referred to as "rear". In addition, the chip inflow side or the front side of the guideway is called "upstream", and the chip discharge side or the back side of the guideway is called "downstream". The rake face is called "upper" or "lower". is assumed to be a negative gradient (the inclination angle is a negative number).

(2) Unless otherwise specified, "x to y" as used herein includes the lower limit value x and the upper limit value y. A new range such as “a to b” can be established as a new lower or upper limit of any numerical value included in the various numerical values or numerical ranges described herein.

It is a principal part sectional view which shows an example of a cutting device. It is a figure which shows the example of various forms of a channel|path cross section. It is a principal part sectional view which shows the other example of a cutting device. It is a figure which shows the range in which a continuous chip is smoothly guided.

In addition to the components of the present invention described above, one or more optional components selected from this specification may be added. A component relating to a method can also be a component relating to a product. Which embodiment is the best depends on the target, required performance, and the like.

《Taxiway》
The guideway is a passage formed above the rake face, below the trailing edge, or laterally, and has an inlet for taking in continuous chips generated at the cutting edge and an outlet for discharging the continuous chips at a predetermined position. In the case of the present invention, the passage cross-sectional area from the inlet to the outlet is constant or increases (monotonically).

(1) As an example, FIG. 1 shows a cutting apparatus S1 having such a guide path. The cutting device S1 comprises a throwaway tip 1 which is a cutting tool, a shank 3 to which the tip 1 is attached, and a duct 2 attached from the rake face 12 of the tip 1 to the upper surface of the shank 3. Note that FIG. 1 is a cross-sectional view seen in a plane perpendicular to the ridge line of the cutting edge 11 of the tip 1. As shown in FIG.

The duct 2 has a continuous chip introduction port 21 on the front end side slightly retreated from the cutting edge 11 of the tip 1 and a continuous chip discharge port 22 on the rear end side. The introduction port 21 and the outlet port 22 are connected by a cover 23 , and a passage 20 (guiding path) is formed inside the cover 23 .

The cover 23 has an upper wall 231, left and right side walls 232, and a lower wall 233, and as is clear from FIG. ing. The slope (α) of the upper wall 231 is preferably adjusted in the range of 0° to 45°, further 10 to 30° with respect to the reference plane (rake face 21). The lower wall 233 may be replaced by the upper surfaces of the rake face 12 and the shank 3 .

The cross-sectional shape of the passage 20 is rectangular as shown in FIG. It may be elliptical as shown in FIG. 2(c).

(2) As another example, a cutting device S2 having a guideway is shown in FIG. The cutting device S<b>2 includes a cutting tool 5 and a duct 6 (guiding path) extending rearward from the rake face 52 of the cutting tool 5 . Note that FIG. 3 is also a cross-sectional view of the cutting tool 5 seen in a plane perpendicular to the ridgeline of the cutting edge 51 .

The duct 6 has a continuous chip introduction port 61 on the front end side slightly retreated from the cutting edge 51 of the cutting tool 5 and a continuous chip discharge port 62 on the rear end side. The introduction port 61 and the outlet port 62 are connected by a cover 63 , and a passage 60 (guiding path) having a rectangular cross section is formed inside the cover 63 .

By the way, the cutting tool 5 has a sloped surface 53 that slopes downward from the trailing edge of the rake face 52 . The passage 60 is formed with the upper wall 631 and the left and right side walls 632 of the cover 63 as well as the rake face 52 and the inclined face 53 of the cutting tool 5 as lower walls. As is clear from FIG. 3, the cross-sectional area of the passage 60 also increases from the inlet 61 toward the outlet 62 . The slope (β) of the inclined surface 53 is preferably adjusted in the range of -45° to 0°, further -30° to -10° with respect to the reference plane (rake face 61). Although FIG. 3 shows the case where the upper wall 631 is parallel to the reference plane (rake face 61), the inclination of the upper wall 631 can be changed in the same manner as the inclination of the upper wall 231 shown in FIG. good.

1 or 3 exemplifies the case where the passage cross-sectional area is constant or monotonously increases linearly (linearly), but unless the passage cross-sectional area decreases from the inlet to the outlet, The change in cross-sectional area may be curvilinear or stepwise, and the cross-sectional shape of the passage itself may also change along the way. Furthermore, the guide path may be formed independently of the cutting tool or the like, or may be formed using the rake face of the cutting tool or the like.

(3) As shown in Figure 1 or Figure 3, if the guideway has an upper wall or a lower wall, their respective gradients (α, β) are as follows, with the rake face (gradient: 0°) as a reference: It is preferable to have such a relationship.
Condition a: α-β≧0°, Condition b: α≦45°, Condition c: β≧−45° (further 10°≧β)

According to the condition a, the passage cross-sectional area of the guideway can be made constant or increasing. Condition b makes it easier to avoid chip retention and backflow. The condition c ensures the strength of the tool (cutting edge).

Therefore, it is preferable that the slope (α) of the upper wall (surface) forming the guideway with respect to the rake face is 0° to 45°, more preferably 10° to 30°. Further, the slope (β) of the lower wall (surface) forming the guideway with respect to the rake face is preferably -45° to 0°, more preferably -30° to -10°.

(4) The distance (t) from the cutting edge to the tip (introduction port) of the guide path is preferably in the range of 1 to 10 mm, more preferably 3 to 7 mm. If this distance is too small, there is a risk of interference with the work material during cutting, and if the distance is too large, the reliability of catching chips in the introduction port may decrease.

Also, in order to ensure the ability to capture chips, the opening area of the inlet is preferably 4 to 225 mm ² , more preferably 16 to 100 mm ² . If the opening of the introduction port is square, it is preferable that one side thereof is about 2 to 15 mm, or even 4 to 10 mm.

The opening area of the outlet is preferably about 1 to 30 times, more preferably 5 to 20 times larger than that of the inlet, in order to ensure discharge and collection of continuous chips.

"Cutting tools"
(1) Any cutting tool may be used as long as it produces continuous chips, and the cutting edge may be straight or curved. The cutting tool may be a turning tool (such as a lathe cutting tool) that performs cutting while rotating the work material, or a shaper tool (such as a milling cutting tool) that performs cutting while linearly moving the work material. In this specification, for the sake of convenience, the case of turning is mainly described.

(2) When the rake face is part of the wall surface of the guideway, it is preferable that the rake face expands from the cutting edge side toward the trailing edge side according to the shape of the guideway. If the length of the rake face is too short, the strength of the cutting edge of the tool tends to decrease. is preferred. It should be noted that the rake face referred to here is intended to have a rake face length of 0.1 mm or more, and does not cover a chamfer or the like having a rake face length of less than 0.1 mm.

《Fluid Supply Unit》
It is preferable to provide a fluid supply portion for supplying a pressurized fluid into the guide path in the direction from the inlet to the outlet, in order to stabilize the shape of chips and improve dischargeability. The fluid to be pressurized may be gas such as air, cutting oil (coolant liquid), mist containing cutting oil components, or the like. At least one injection port, nozzle, or the like for the pressurized fluid may be provided on the upstream side (on the wall surface near the inlet, or the like). In addition to the nozzle and the like, a fluid tank, a pressurizer, and the like may also be included as the fluid supply unit according to the present invention.

Turbulence generated when pressurized fluid (especially compressed air or the like) hits the inner wall surface of the guideway may reduce the fluidity of chips within the guideway. Therefore, it is preferable that the streamline of the pressurized fluid is along the centerline of the guideway (for example, the centerline l shown in FIG. 3).

《Scrap collector》
Preferably, the cutting device of the present invention further comprises a chip collecting section for collecting chips discharged from the outlet. The chip collection unit may be a device for forcibly collecting chips by a rotating brush or the like, in addition to a dust collection box or the like.

Experiments were conducted to confirm continuous chip discharge performance by changing the cross-sectional shape and cross-sectional area of the guideway. The present invention will be described more specifically based on these experimental results.

《Cutting device》
In addition to the slope (β) of the inclined surface 53 shown in FIG. 3, a large number of experimental cutting devices were prepared in which the slope (α) of the upper wall 631 and the sizes of the inlet 61 and the outlet 62 were varied. . Such a cutting device was used for the following experiments. When β<0°, the cross-sectional area of the passage 60 forming the guideway is expanded from the trailing edge of the rake surface 52 (the boundary between the rake surface 52 and the inclined surface 53).

"experiment"
Turning was performed under the following conditions to confirm the effect of the guideway.
Cutting tool: Carbide tool (straight cutting edge), rake angle 0°, rake face length: 0.1 to 3 mm,
Work material: carbon steel (JIS: S45C), cutting width: 2 mm,
Cutting thickness: 0.1 mm/rev, cutting speed: 212 m/min,
Distance from cutting edge to introduction port (tip): 1 to 10 mm,
Inlet size (height, width): 2 to 15 mm
Outlet size (height, width): 5 to 40 mm
Upper wall gradient α: -45 to 45° Lower wall (inclined surface) gradient β (inclined surface angle): -45 to 0°

"evaluation"
As a result of repeating a number of experiments, it was confirmed that continuous chips generated from the work material can be smoothly discharged from the outlet without stagnating in the middle at least within the range shown in Fig. 4. .

S1 cutting device 1 tip (cutting tool)
11 cutting edge 12 rake face 2 duct 20 passage (guideway)
21 inlet 22 outlet 23 cover

Claims (4)

an insert having a cutting edge for cutting a work material and a rake face connected to the rear of the cutting edge;
a duct that has a cover that extends rearward from above the rake face, takes in continuous chips generated from the work material from an inlet formed on the cutting edge side, and guides them to an outlet formed on the rear side of the rake face; with
the tip has a sloped surface that slopes downward from the trailing edge of the rake face at a different slope than the rake face;
the rake face and the inclined face form at least a portion of the lower wall of the duct;
The cutting device, wherein the passage cross-sectional area of the duct is larger at the outlet than the inlet and does not decrease from the inlet to the outlet. 2. The cutting device according to claim 1, further comprising a fluid supply unit that supplies pressurized fluid into the duct in a direction from the inlet to the outlet. the slope of the upper wall of the duct with respect to the rake face is 0° to 45°;
3. The cutting device according to claim 1, wherein the slope of the bottom wall of the duct with respect to the rake face is -45° to -10°. The cutting device according to any one of claims 1 to 3, wherein the tip is for turning.

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