Skiving machine

Abstract

To provide a skiving machine that can efficiently cool a gear-shaped cutter held at the tip of the holder of the skiving machine and prevent a decrease in dimensional accuracy caused by thermal expansion of when the temperature rises.SOLUTION: A configuration of a skiving machine according to the present invention is characterized in that in a skiving machine (machine 100) in which a gear-shaped cutter 200 is held at a tip of a holder, the holder 300 includes a central flow path 310 through which a fluid flows. The cutter 200 includes: a plurality of blades 210; a plurality of cutting grooves 220; and a plurality of discharge holes 230 formed in cutting bottoms 222 of the plurality of cutting grooves 220 and connected to the central flow path 310.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a skiving machine in which a gear-shaped cutter is held at the tip of a holder. [Background technology]

[0002] Skiving is a well-known machining method for creating gears. Skiving is performed by synchronizing the rotation of the skiving cutter, a cutting tool, with the rotation of the workpiece, which is the object to be machined, while tilting the rotation axis of the skiving cutter (cutter axis) relative to the rotation axis of the workpiece (work axis). This creates a difference between the rotation direction of the workpiece and that of the skiving cutter, causing "slip" when the skiving cutter interferes with the workpiece. This slip is used to remove the interfering parts from the workpiece, and to machine tooth grooves and other features into the workpiece.

[0003] Like normal cutting, skiving is performed while supplying fluids such as coolant (cooling liquid) or air (blower) for lubrication and cooling. Among these, processing performed while supplying air (blower) is called dry processing. For example, Patent Document 1 discloses "an air cooling method for a tool mounting portion of a spindle of a machine tool, which prevents heat transfer from a tool mounted on the tool mounting portion of the spindle of a machine tool to the spindle."

[0004] The air cooling method of Patent Document 1 is characterized by "discharging cleaning air for cleaning the spindle tool mounting portion through the inside of the spindle during machining operation of the machine tool, thereby cooling the spindle tool mounting portion and suppressing heat generation in the tool mounting portion." Patent Document 1 also states that "the cleaning air is discharged when the continuous cutting time of the tool is calculated in advance using an NC (numerical control) machining program, and it is determined that if this time is exceeded, the tool will no longer be able to be removed from the tool mounting portion of the spindle using the normal removal method." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-24875 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 focuses on cooling the spindle tool mounting section so that the tool can be removed from the spindle tool mounting section in the normal manner. However, the temperature of the tool also rises during dry machining, and as the tool temperature rises, the tool expands thermally, causing variations in dimensional accuracy. The technology in Patent Document 1 was unable to solve these issues, and there was room for further improvement in the technology in Patent Document 1.

[0007] In view of these problems, the present invention aims to provide a skiving machine that can efficiently cool the gear-shaped cutter held at the tip of the holder of the skiving machine and prevent a decrease in dimensional accuracy due to thermal expansion when the temperature rises. [Means for solving the problem]

[0008] In order to solve the above problems, a typical configuration of the skiving machine according to the present invention is a skiving machine in which a gear-shaped cutter is held at the tip of a holder, the holder having a central flow path through which a fluid flows, and the cutter having a plurality of blades, a plurality of cutting grooves, and a plurality of discharge holes formed in the blade bottoms of the plurality of cutting grooves and communicating with the central flow path.

[0009] The cutter preferably has an annular passage formed in the cutter along the arrangement of the blades, and the annular passage preferably communicates with the central passage and the plurality of discharge holes.

[0010] The discharge holes may be formed in all of the blade bases.

[0011] The skiving machine may include a cold air generator that generates low-temperature air, and the fluid may be low-temperature air supplied from the cold air generator.

[0012] The skiving machine is provided with a temperature detection sensor that detects the surface temperature of the cutter, and when the surface temperature of the cutter detected by the temperature sensor is equal to or higher than a predetermined temperature, cold air is discharged from a cold air generator to cool the cutter. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a skiving machine that can efficiently cool the gear-shaped cutter held at the tip of the holder of the skiving machine and prevent a decrease in dimensional accuracy due to thermal expansion when the temperature rises. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of a skiving machine according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating a cutter and a holder. [Figure 3] 10A and 10B are diagrams illustrating other examples of the cutter and holder according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention and, unless otherwise specified, do not limit the present invention. In this specification and drawings, elements having substantially the same functions and configurations are designated by the same reference numerals to avoid redundant explanation, and elements not directly related to the present invention are not shown or described.

[0016] Fig. 1 is a diagram illustrating the schematic configuration of a skiving machine according to this embodiment. The skiving machine of this embodiment shown in Fig. 1 (hereinafter referred to as machine 100) machines a gear by synchronously rotating a workpiece W and a gear-shaped cutter 200. As shown in Fig. 1, machine 100 of this embodiment has a work spindle 120, a tool spindle 130, and a control device 190 that controls the operations of these.

[0017] The workpiece W is replaceably attached to the workpiece spindle 120, and the attached workpiece W is rotated around the workpiece axis C. The workpiece spindle 120 of the processing machine 100 is movable in the workpiece axis direction Z (the same direction as the Z-axis direction described later), which is the axial direction of the workpiece axis C attached to the workpiece spindle 120.

[0018] Specifically, the workpiece spindle 120 is placed on the fixed bed 110 via a table 122, and a Z-axis drive screw 124 is inserted into the table 122. A Z-axis drive motor 126, which is a drive source for rotating the Z-axis drive screw 124, is connected to the Z-axis drive motor 126. As a result, by driving the Z-axis drive motor 126, the Z-axis drive screw 124 rotates, and the workpiece spindle 120 on the table 122 can be moved in the Z-axis direction (i.e., the workpiece axis direction Z).

[0019] The cutter 200 is replaceably attached to the tool spindle 130, which rotates the attached cutter 200 around the tool axis B. The tool spindle 130 is also movable in the X-axis direction (a direction moving toward and away from the work axis C in a horizontal direction: the front-to-back direction in the drawing) and the Y-axis direction (a direction moving toward and away from the work axis C in a vertical direction: the up-to-down direction in the drawing), and is also rotatable in the A-direction (rotation in a vertical plane parallel to the tool axis B).

[0020] 1, a holder 300 holding a gear-shaped cutter 200 at its tip is attached to the tool spindle 130. That is, the cutter 200 is attached to the tool spindle 130 via the holder 300.

[0021] 2A and 2B are diagrams illustrating the cutter 200 and the holder 300. The cutter 200 is attached to the holder 300 shown in Fig. 2A by a fixing bolt 304 with a washer 302 sandwiched between them. A central flow passage 310, through which a fluid flows, is formed inside the holder 300 and extends in the axial direction. In this embodiment, a branch flow passage 312 is formed inside the holder 300 and communicates with the central flow passage 310 and extends from there toward the cutter 200.

[0022] The cutter 200 shown in Figures 2(a) and (b) does not have a shank and has a shape known as a bell-shaped tool. The cutter 200 has a plurality of cutting edges 210, a plurality of cutting grooves 220, and a plurality of discharge holes 230. A feature of this embodiment is that the plurality of discharge holes 230 are formed in the cutting bottoms 222 of the plurality of cutting grooves 220 and communicate with the central flow passage 310 (in this embodiment, they communicate with the central flow passage 310 via branch flow passages 312). This allows fluid to flow from the central flow passage 310 (and the branch flow passages 312) of the holder 300 to the plurality of discharge holes 230.

[0023] According to the above configuration, the fluid is discharged from the multiple discharge holes 230 into the cutting grooves 220 of the cutter 200, thereby cooling the entire cutter 200. This makes it possible to efficiently cool the gear-type cutter 200 of the processing machine 100 and effectively suppress a rise in temperature of the cutter 200. Therefore, it is possible to prevent a decrease in dimensional accuracy due to thermal expansion when the temperature rises.

[0024] Furthermore, the discharge hole 230 is provided so as to be inclined toward the cutting edge (cutting tip) of the blade 210. This allows the fluid ejected from the discharge hole 230 to blow away and remove chips generated by cutting. This prevents the chips from adhering and prevents them from getting caught in the processed area, causing chips on the tool blade or scratches on the processed surface. This effect is particularly effective in internal gear machining, where chips tend to stick due to centrifugal force.

[0025] In this embodiment, a configuration is exemplified in which the discharge holes 230 are formed in all of the cutting bottoms 222. This maximizes the effect of cooling the cutter 200. However, this is not limited to this, and it is sufficient that the discharge holes 230 are formed in at least one of all of the cutting bottoms 222, and the number of discharge holes can be set appropriately, for example, every other or every third cutting groove 220.

[0026] In this embodiment, the cutter 200 has an annular flow passage 314 formed in an annular shape inside the cutter 200 so as to follow the arrangement of the plurality of blades 210 (see FIG. 2(b)). The annular flow passage 314 connects the central flow passage 310 and the plurality of discharge holes 230. This allows the fluid supplied from the central flow passage 310 to be efficiently distributed to the plurality of discharge holes 230.

[0027] Furthermore, the processing machine 100 of this embodiment is equipped with a cold air generator 320 that generates low-temperature air. As the cold air generator 320, for example, a cold air generator that utilizes the vortex effect can be used. In this embodiment, the low-temperature air supplied from the cold air generator 320 is used as the fluid. This allows the cutter 200 to be cooled more efficiently, thereby enhancing the above-mentioned effects.

[0028] The processing machine 100 of this embodiment also includes a temperature detection sensor 180 that detects the surface temperature of the cutter 200. The temperature detection sensor 180 is fixed to the fixed bed 110 via a sensor moving device 182. The sensor moving device 182 moves the temperature detection sensor 180 forward and backward relative to the cutter 200.

[0029] In this embodiment, the control device 190 first moves the temperature detection sensor 180 toward the cutter 200 to a detection position using the sensor moving device 182. The temperature detection sensor 180 then detects the surface temperature of the cutter. If the surface temperature of the cutter 200 detected by the temperature detection sensor 180 is equal to or higher than a predetermined temperature, the control device 190 discharges low-temperature air from the cool air generator 320 to cool the cutter 200 down to below the predetermined temperature.

[0030] If the surface temperature of the cutter 200 is below a predetermined temperature, or if the cutter 200 has been cooled to below the predetermined temperature, the control device 190 moves the temperature detection sensor 180 to a retracted position using the sensor moving device 182. This configuration makes it possible to prevent the cutter 200 from being overcooled by low-temperature air, and also to reduce the amount of air used because excessive or unnecessary cooling is not performed, thereby contributing to energy savings.

[0031] 3 is a diagram illustrating another example of the cutter 200 and the holder 300 of this embodiment. Note that components common to the cutter 200 and the holder 300 described using FIG. 2 are denoted by the same reference numerals and description thereof will be omitted.

[0032] 3 holds the cutter 200a by clamping the shaft 202 of the cutter 200a with a chuck (not shown). A central flow passage 310 through which a fluid flows is formed inside the holder 300a so as to extend in the axial direction.

[0033] As shown in Fig. 3, the cutter 200a has a shank (a shaft for gripping), which is what is called a shank-type cutter. The cutter 200a has a shaft 202 held in a holder 300a. An in-shaft passage 204, through which a fluid flows, is formed inside the shaft 202 and extends in the axial direction, and the in-shaft passage 204 communicates with a central passage 310 of the holder.

[0034] 3 also has a plurality of discharge holes 230 formed in the cutting edge bottoms 222 of a plurality of cutting grooves 220. These discharge holes 230 communicate with the central flow path 310 through the in-shaft flow path 204, so that the fluid flows from the central flow path 310 of the holder 300 in a dispersed manner to the plurality of discharge holes 230. Therefore, the cutter 200a shown in FIG. 3 can also achieve the same effect as the cutter 200 shown in FIG.

[0035] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to these examples. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the claims, and it is understood that these modifications and alterations also fall within the technical scope of the present invention. [Industrial Applicability]

[0036] The present invention can be used in a skiving machine in which a gear-shaped cutter is held at the tip of a holder. [Explanation of symbols]

[0037] 100...machine, 110...fixed bed, 120...workpiece spindle, 122...table, 124...Z-axis drive screw, 126...Z-axis drive motor, 130...tool spindle, 180...temperature detection sensor, 182...sensor moving device, 190...control device, 200...cutter, 200a...cutter, 202...shaft, 204...inner-shaft flow passage, 210...blade, 220...blade groove, 222...blade bottom, 230...discharge hole, 300...holder, 300a...holder, 302...washer, 304...fixing bolt, 310...central flow passage, 312...branch flow passage, 314...annular flow passage, 320...cool air generator, B...tool axis, C...workpiece axis, W...workpiece, Z...workpiece axis direction

Claims

1. In a skiving machine in which a gear-shaped cutter is held at the tip of the holder, The holder has a central passage through which a fluid flows; The cutter is Multiple blades and A plurality of cutting grooves; a plurality of discharge holes formed in the blade bottoms of the plurality of cutting grooves and communicating with the central flow passage; A skiving machine comprising:

2. the cutter has an annular flow path formed annularly within the cutter along the arrangement of the plurality of blades; The skiving machine according to claim 1, wherein the annular flow path communicates with the central flow path and the plurality of discharge holes.

3. The skiving machine according to claim 1 or 2, wherein the discharge holes are formed in all of the blade bottoms.

4. Equipped with a cold air generator that generates low-temperature air, The skiving machine according to claim 1, wherein the fluid is low-temperature air supplied from the cold air generating device.

5. a temperature detection sensor for detecting a surface temperature of the cutter; The skiving machine according to claim 4, characterized in that, when the surface temperature of the cutter detected by the temperature sensor is equal to or higher than a predetermined temperature, the low-temperature air is discharged from the cold air generator to cool the cutter.

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