Outer periphery machining device

Abstract

To provide an outer periphery machining device capable of appropriately feeding a coolant to a blade tool even for a hard cylindrical workpiece and suppressed in burning.SOLUTION: An outer periphery processing device 1 passes a cylindrical workpiece W through a work hole 13 to grind the outer peripheral surface of the cylindrical workpiece W. The outer periphery processing device 1 comprises: a base part 8; a shaft body 6; and a machining unit 20, 40 attached to the shaft body 6. A doughnut-shaped impeller chamber 7 is provided between the base part 8 and the shaft body 6. A plurality of impellers 15 attached to the shaft body 6 circulate in the impeller chamber 7, thereby causing the guide plane 15a of each impeller 15 to feed a coolant fed into the impeller chamber 7 through a coolant passage 3a, 3c, 3d provided in the shaft body 6, and the coolant fed through the passage 3a, 3c, 3d is jetted out from a nozzle 23c, 49 directed toward a blade tool of the machining unit 20, 40.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a peripheral processing device for cutting or grinding the peripheral of cylindrical metal workpieces such as cylinders and tubes, and in particular to a peripheral processing device suitable for polishing or grinding the peripheral of quenched and hardened workpieces. [Background technology]

[0002] Generally, lathes, cylindrical grinding machines, etc. are known as machines for processing the outer periphery of cylindrical metal workpieces. These machines hold the cylindrical workpiece on one side or both sides, and grind it by pressing a cutting tool or a grinding wheel against the outer periphery while rotating the cylindrical workpiece.

[0003] Meanwhile, Patent Documents 1 and 2 disclose known burnishing techniques. Patent Document 1 describes a method of cutting a cylindrical workpiece to dimensions suitable for burnishing before burnishing. This cutting method involves using a cutting unit having at least three cutting tools and a drive unit to rotate the cutting tools around a rotation center without rotating the cylindrical workpiece. The cutting tool orbits the periphery of the cylindrical workpiece to cut the outer surface of the cylindrical workpiece. Burnishing is a process that removes scratches and other abnormal layers from the surface of the workpiece without producing chips by crushing the outer surface of the workpiece with a roller. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-5570 [Patent Document 2] Publication No. 3220246 [Patent Document 3] Japanese Utility Model Application Publication No. 7-10686 Summary of the Invention [Problem to be solved by the invention]

[0005] The cutting techniques disclosed in Patent Documents 1 and 2 eliminate the need to rotate a cylindrical workpiece while holding it on one side or both sides, as opposed to lathe or cylindrical grinding machine techniques. The cylindrical workpiece is fed through a cutting unit and cut, making it possible to handle long cylindrical workpieces. However, it is difficult to achieve a uniform surface roughness on a cylindrical workpiece using only this type of cutting.

[0006] Furthermore, in cutting work, it is necessary to wash away the chips that are generated by using a coolant (cooling liquid), but the techniques of Patent Documents 1 and 2 make no mention of a coolant.

[0007] Incidentally, when a cutting tool is placed on the inner periphery of a cylindrical workpiece and the inner periphery is cut by rotating the cutting tool, it is easy to spray coolant toward the cutting tool by centrifugal force by applying the technology of Patent Document 3 to the center of rotation of the cutting tool. On the other hand, when the outer periphery of a cylindrical workpiece is ground by rotating the cutting tool around the center of rotation without rotating the cylindrical workpiece, coolant is supplied from the outer periphery to the cutting tool close to the center of rotation, and the coolant is pushed back toward the outer periphery by centrifugal force.

[0008] In particular, when cutting the outer periphery of a very hard cylindrical workpiece (such as a hardened piston rod), it is not enough to simply flush away the chips; if the cutting tool is not properly cooled by supplying coolant, seizure will easily occur.

[0009] The first object of the present invention is to provide a peripheral machining device that can handle long cylindrical workpieces, and the second object of the present invention is to provide a peripheral machining device that can properly supply coolant to cutting tools even for very hard cylindrical workpieces and suppress seizure. [Means for solving the problem]

[0010] The present invention provides a peripheral processing device that passes a cylindrical workpiece through a work hole, and rotates a cutting tool around the axis of the work hole without rotating the cylindrical workpiece, thereby grinding the outer peripheral surface of the cylindrical workpiece, comprising: a base portion; a shaft body rotatably supported on the base portion and having the work hole at the center; and a processing unit attached to the shaft body, A donut-shaped impeller chamber is provided between the base portion and the shaft body, and as multiple impellers attached to the shaft body rotate within the impeller chamber, the guide surface of each impeller sends the coolant supplied into the impeller chamber into a coolant passage provided in the shaft body, and the coolant sent through the passage is sprayed out from a nozzle aimed at the cutting tool of the processing unit. [Effects of the Invention]

[0011] In the peripheral machining device according to the present invention, the coolant pressurized by the impeller is ejected toward the tip of the cutting tool without being affected by centrifugal force, thereby preventing the cutting tool from seizing. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. [Figure 2] FIG. 2 is a cross-sectional view of a peripheral processing device to which a polishing tool is attached. [Figure 3] XX cross-sectional view of the main shaft. [Figure 4] FIG. 2 is a diagram illustrating a polishing tool. [Figure 5] FIG. 2 is a cross-sectional view of a peripheral processing device to which a grinding tool is attached. [Figure 6] FIG. 2 is a diagram illustrating a grinding tool. [Figure 7] FIG. 2 is a diagram illustrating an angle of attack. DETAILED DESCRIPTION OF THE INVENTION

[0013] FIG. 1 shows a peripheral processing device 1 according to one embodiment of the present invention. This peripheral processing device 1 can continuously perform grinding and polishing on a long cylindrical workpiece. The cylindrical workpiece may be a hollow pipe or a solid rod-shaped member. The peripheral processing device 1 includes a processing unit 20 and a spindle 2. The spindle 2 and processing unit 20 share a working hole 13 through which the cylindrical workpiece passes.

[0014] The processing unit 20 provides a surface finish equivalent to that of a rotary grinding wheel to hardened metal.

[0015] The mounting body 3 for the spindle 2 is a hollow disk having a work hole 13 centered on the axis c of the spindle 2. The cylindrical workpiece passes through the work hole 13. The surface 3s of the mounting body 3 extends in the radial direction r centered on the axis c. On the surface 3s, multiple fixing protrusions 5 are provided at equal angular intervals and at the same radial position centered on the axis c. The fixing protrusions 5 are provided to fix the machining unit 20 or the machining unit 40 with one touch, and have a bulge 5a at the top. A ring body 4 is attached to the outer periphery of the mounting body 3. A positioning reference mark 4a is displayed on the ring body 4.

[0016] When attaching the machining unit 20, the spindle 2 is operated so that the mark 4a is at the top position. An eyebolt 16 is attached to the machining unit 20. The hook of a crane (not shown) is hung on the eyebolt 16 to hoist the machining unit 20 and press it against the surface 3s of the mounting body 3, so that the fixing protrusion 5 is inserted into the mounting hole (described later) of the machining unit 20. The machining unit 20 is accurately attached to the spindle 2 by rotating the machining unit 20 clockwise. At this time, the inter-ring 22 fits into the tapered portion 3e on the mounting body 3 side. The machining unit 20 is rotated counterclockwise R by the spindle 2.

[0017] In Figure 2, the main shaft 2 comprises a shaft body 6 that supports the rear of the mounting body 3 and a gear 11 attached to the shaft body 6. The shaft body 6 is cylindrical, with a hollow portion forming a working hole 13. The shaft body 6 is rotatably attached to a base portion 8 by a bearing 10.

[0018] A coolant passage 3a is provided in the mounting body 3, and an outlet 3b opens on a surface 3s of the mounting body 3. The passage 3a is connected to an impeller chamber 7 of the shaft body 6. The impeller chamber 7 is a doughnut-shaped space, and a ring groove 9b provided in a supply block 9 of the base body 8 forms the ceiling surface on the outer periphery. The supply block 9 is fixed to the base body 8 as part of the base body 8. A supply passage 9a connected to a coolant supply pipe 17 from the outside is drilled in the supply block 9, and coolant is supplied from the supply passage 9a to the ring groove 9b.

[0019] An outlet 3b opening on the surface 3s of the mounting body 3 communicates with a coolant inlet 22a on the machining unit 20 side when the mounting body 3 is correctly attached to the spindle 2. The shaft body 6 receives rotational force from the gear 12 via the gear 11 and rotates around the axis c. The direction of the axis c is from right to left on the page. The cylindrical workpiece W is inserted from the right side of the page through a work hole 13 on the machining unit 20 side. The gear 12 is driven by an electric motor (not shown).

[0020] FIG. 3 is a cross section taken along the line XX, perpendicular to the axis c at the position of the impeller chamber 7 of the shaft body 6. Within the impeller chamber 7, multiple (six in this embodiment) impellers 15 are mounted at equal angular intervals around the periphery of the shaft body 6, and revolve around the axis c within the impeller chamber 7 as the shaft body 6 rotates. A passage 6d is provided within the shaft body 6, leading toward the axis c, corresponding to each impeller 15. Each passage 6d is connected to an annular passage 3c within the shaft body 6. The annular passage 3c is connected to the passage 3a via the passage 3d. Three passages 3a are provided at equal angular intervals. Meanwhile, on the supply block 9 side, a ring groove 9b is provided along the outer periphery around which the impeller 15 revolves. The ring groove 9b is connected to three supply passages 9a, which are provided at equal angular intervals.

[0021] When the shaft body 6 rotates counterclockwise R, the coolant supplied into the impeller chamber 7 is introduced into the passage 6a along the guide surface 15a of the impeller 15. When the shaft body 6 rotates, centrifugal force is generated that pushes the coolant outward, but the coolant receives pressure from the impeller 15 that overcomes this force and is introduced into the passage 6a.

[0022] Fig. 4 shows the processing unit 20. Fig. 4A is a rear view, Fig. 4B is a front view, Fig. 4C is a YY cross-sectional view, and Fig. 4D is a partially enlarged cross-sectional view.

[0023] The fixing hole 21a has a large-diameter opening 21b and a small-diameter opening 21c that are connected together, and the expanded portion 5a enters the large-diameter opening 21b. By rotating the processing unit 20 clockwise, the expanded portion 5a moves to the position of the small-diameter opening 21c and cannot escape. In this way, the processing unit 20 is fixed to the mounting body 3.

[0024] The machining unit 20 has a hollow centered on the axis c and forming part of the work hole 13. The machining unit 20 includes a donut-shaped body 21, an inter-ring 22 sandwiched between the mounting body 3 and the body 21, one cutting tool block 23, two guide pad blocks 24 of the same shape as the cutting tool block 23, and three guide pad blocks 25 that are smaller than the cutting tool block 23. The cutting tool block 23 and the guide pad blocks 24, 25 are arranged at equal angular intervals around the axis c. A cutting tool 23a is attached to the cutting tool block 23. This cutting tool 23a is a cutting tool that performs grinding processing equivalent to that of a CBN (ultra-high pressure sintered body) grinding wheel. A guide pad 24a, 25a is attached to each guide pad block 24, 25, and guides the cylindrical workpiece W so that its center coincides with the axis c.

[0025] The coolant inlets 22a on the machining unit 20 side are provided in the inter-ring 22. The coolant inlets 22a are provided at equal angular intervals, and each corresponds to an outlet 3b of the mounting body 3. The coolant entering from the inlets 22a is communicated with a nozzle 23c via a passage 23b in the cutting tool block 23. The nozzle 23c is attached to the cutting tool block 23, and its outlet is directed toward the cutting tool 23a. The coolant is pressure-fed by the impeller 15 and sprayed from the nozzle 23c toward the tip of the cutting tool 23a.

[0026] 7A shows how the cutting tool 23a contacts the cylindrical workpiece W. In this embodiment, the angle of attack θ of the cutting tool 23a when the cylindrical workpiece W moves along the axis c is set to be greater than or equal to 3 degrees and less than 10 degrees, which is extremely shallow compared to the 20 degrees of a normal cutting tool. Due to this angle of attack θ and the effect of the coolant being pumped by the impeller 15, the machining unit 20 was able to achieve a cutting depth of 0.2 mm and an RA of 1.0 (within Rz 3.0 and Ry 3.0) on a cylindrical workpiece with a hardened hardness of HRC 58 (assuming a piston rod with a diameter of 100 mm).

[0027] FIG. 5 shows the machining unit 40. The machining unit 40 performs machining on curved metal, although the degree of finishing is lower than that of the machining unit 20. Both units machine cylindrical workpieces. The machining unit 40 has a hollow centered on the axis c that forms part of the work hole 13, allowing grinding to be performed in accordance with the curvature of the cylindrical workpiece W. The machining unit 40 includes a cylindrical main body 41, a sub-body 42, an inter-ring 22, a plurality of cutting tool blocks 45 (three in this embodiment) arranged at equal angular intervals, and guide pad blocks 46 (three in this embodiment) arranged between the cutting tool blocks 45. The machining unit 40 is attached to the spindle 2 in the same manner as the machining unit 20 is attached to the spindle 2.

[0028] A donut-shaped sliding groove 47 is provided between the main body 41 and the sub-body 42, and an interlocking ring 44 is housed therein. The interlocking rod of the cutting tool block contacts the interlocking ring 44 in the sliding groove 47. The sliding groove 47 allows the interlocking ring 44 to move in a direction perpendicular to the axis c (radial direction r). The hemispherical top of the interlocking rod 48 abuts against the interlocking ring 44, faithfully transmitting the movement of the interlocking ring 44 in the radial direction r to the cutting tool block 45. A cutting tool 45a is attached to the cutting tool block 45. As shown in Figure 7B, the angle of attack θ of the cutting tool 45a in this embodiment is equal to or greater than 3 degrees and less than 10 degrees.

[0029] When the processing unit 40 is rotated around the axis c, the cutting tool block 45 rotates around the cylindrical workpiece W inserted in the work hole 13. The cutting tool block 45 is linked by the linking ring 44, and even if the cylindrical workpiece W is curved, the position of the cutting tool 45a of the cutting tool block 45 is adjusted in accordance with the curve of the cylindrical workpiece W.

[0030] The coolant inlets 22a on the machining unit 40 side are provided in the inter-ring 22. The coolant inlets 22a are provided at equal angular intervals, and each corresponds to an outlet 3b of the mounting body 3 (see FIG. 6). The coolant entering from the inlets 22a is connected to a nozzle 49. The nozzle 49 has an outlet 49a directed toward the cutting tool 45a. The coolant is pressure-fed by the impeller 15 and sprayed from the outlet 49a toward the cutting tool 45a.

[0031] As described above, the outer periphery processing device 1 of this embodiment can process the cylindrical workpiece W without rotating it. This allows processing regardless of the length of the cylindrical workpiece W. Furthermore, the coolant pressurized by the impeller 15 is ejected toward the tips of the cutting tools 23a, 45a without being affected by centrifugal force, thereby preventing the cutting tools 23a, 45a from seizing. Furthermore, the angle of attack θ of the cutting tools 23a, 45a is greater than or equal to 3 degrees and less than 10 degrees, thereby reducing the roughness of the processed surface. In particular, the processing unit 20 can efficiently cool the cutting tool 23a, allowing the surface roughness of extremely hard cylindrical workpieces W to be finished with high precision. [Explanation of symbols]

[0032] 1 Periphery processing equipment 2 main shaft 3 Mounting body 3a aisle 3b exit 3c Circular Passage 3d aisle 3e Tapered section 3s surface 4 ring body 4a Mark 5 Fixed protrusion 5a Ampulla 6-axis body 6d Passage 7 Impeller chamber 8 Base 9 Supply Block 9a Supply passage 9b Ring groove 10 bearings 11 Gears 12 Gears 13 Working hole 15 impeller 15a Guidance surface 16 eyebolts 17 Coolant supply pipe 20, 40 processing units 21 Body 21a Fixing hole 21b opening 21c aperture 22 Interring 22a entrance 23 Cutting tool block 23a, 45a cutter 23b aisle 23c nozzle 24, 25 Guide pad block 24a, 25a guide pad 41 Main Body 42 Subbody 44 Interlocking Ring 45 Cutting block 46 Guide Pad Block 47 Sliding groove 48 Interlocking rod 49 nozzles 49a spout

Claims

1. In a peripheral processing device for grinding the peripheral surface of a cylindrical workpiece by passing a cylindrical workpiece through a work hole and rotating a cutting tool around the axis of the work hole without rotating the cylindrical workpiece, a base portion; a shaft body rotatably supported on the base portion and having the work hole at the center; and a processing unit attached to the shaft body, A donut-shaped impeller chamber is provided between the base portion and the shaft body, and multiple impellers attached to the shaft body rotate within the impeller chamber, causing the guide surface of each impeller to send coolant supplied into the impeller chamber into a coolant passage provided in the shaft body, and the coolant sent through the passage is sprayed out from a nozzle aimed at the cutting tool of the processing unit.

2. 2. The outer periphery machining device according to claim 1, wherein the angle of attack of the cutting tool when the cylindrical workpiece moves along the axis is equal to or greater than 3 degrees and less than 10 degrees.

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