KR970003258B1 - A scroll lap machining end mill - Google Patents

Abstract

None.

Description

End Mills for Scroll Wrap

1 is a longitudinal sectional view showing a main part of a scroll compressor machined by the end mill of the present invention.

FIG. 2 is an enlarged cross-sectional view of the chamfer at the bottom and the tip of the wrap in FIG. 1; FIG.

3A, 3B and 3C are longitudinal cross-sectional views showing one specific example of the lapping process in FIG.

4 is a graph showing one example of the relationship between the plane width of the wrap upper surface and the gas leakage amount shown in FIG.

Fig. 5 is a longitudinal sectional view showing a main part of another example of a scroll compressor processed by an end mill according to the present invention.

FIG. 6 is an enlarged cross-sectional view of the chamfer at the bottom and the tip of the wrap in FIG. 5; FIG.

7A and 7B are longitudinal sectional views showing one specific example of the machining process of the lap in FIG.

8 is an external view showing one embodiment of the end mill for scroll wrap processing according to the present invention.

9 and 9 are views showing the machining state of the scroll wrap according to the embodiment shown in FIG.

10 and 10 are external views showing another embodiment of the end mill for scroll wrap processing according to the present invention.

11A and 11B are cross-sectional views showing the tip shape of the cutting edge in FIG.

12 is a longitudinal sectional view showing a main part of an example of a scroll compressor processed by a conventional end mill.

13A and 13B are longitudinal cross-sectional views showing one example of the processing steps for the scroll wrap in FIG.

14A and 14B are longitudinal cross-sectional views showing another conventional example of the scroll wrap machining process.

15A and 15B are configuration diagrams showing an example of a conventional end mill for scroll wrap processing.

The present invention relates to an end mill for processing a fixed scroll and a rotating scroll wrap in a scroll wrap compressor.

As the conventional scroll compressor has a structure described in Japanese Patent Application Laid-Open No. Hei 1-187388, basically, both the inner and outer surfaces of the lap in fixed scroll and swing scroll rise at right angles from the hard plate. Explaining this in detail, it is customary that the wrap has a shape as shown in FIG. In Fig. 12, reference numeral 201 denotes a fixed scroll, 202 a turning scroll, 203a and 203b a lap, 204a and 204b a hard plate, and 205a and 205b a lap. Proximal part, (224a), (224b) is stepped part, (206a), (206b) is lap end part, (225a), (225b) is chamfered part, (207a), (207b) is lap side, ( 209a) and 209b are lap bottom surfaces, and 226 is a void.

As shown in the figure, the lap root portions 205a and 205b of the laps 203a and 203b have small stepped portions 224a and 205 in order to increase the mechanical strength of the wraps 203a and 203b, respectively. 224b) is provided. Moreover, when the fixed scroll 201 and the revolving scroll 202 are combined with the lap end portions 206a and 206b, the chamfered portions 225a do not come into contact with the stepped portions 224a and 224b. ) And 225b are formed.

When the revolving scroll 202 pivots about a central axis (not shown), the lap 203a of the revolving scroll 202 may approach or move away from the lap 203a of the fixed scroll 201, thereby lapping. The refrigerant gas introduced between 203a and 203b is compressed. In this operation, the refrigerant gas is prevented from leaking in the space between the wraps 203a and 203b. To this end, when the wraps 203a and 203b are closer each other between the lap tip 206a and the lap bottom surface 209b and between the lap tip 206b and the lap bottom surfaces 209a and 209b. Of the refrigeration oil mixed in the refrigerant gas in the space between the wrap portions 203a and 203b between the shaped portion 224a and the chamfered portion 225b and between the stepped portion 224b and the chamfered upper portion 225a, respectively. In order to form an oil film, the space | interval between these is set small.

The step-shaped portions 224a and 224b at the lap root portions 205a and 205b are usually formed during cutting of the lap by an end mill. That is, since the cuttings of the wraps 203a and 203b are the same, if the reference numerals a and b are deleted and the respective parts are shown, as shown in FIG. 13, the lap front end 206 and the chamfered shape 225 are previously shown. The wrap side surface 207 is machined with respect to the formed workpiece according to the outer diameter of the end mill 227 (FIG. 13a), and then the wrap bottom surface 209, that is, the hard plate 204, by the tip of the end mill 227 Although the upper surface of the die is processed (Fig. 13b), the process is divided into two to perform cutting of the wrap 203, but the outer diameter of the end mill 227 is a spiral wrap (on the hard plate 204). It is set slightly smaller than the minimum spacing of 203, whereby the stepped portion 224 is formed at the same time as the upper surface of the hard plate 204 shown in FIG.

As another cutting method, first, as shown in Fig. 14A, in a predetermined scroll 201 or a rotating scroll 202 or a work 229 (hereinafter collectively referred to simply as a scroll), formed to a predetermined predetermined dimension, The work side surface 230 of the vortex-shaped protrusion which becomes the lap of this workpiece | work 229 is previously cut by the surface of the lap | tip end part 206, and the side mill end mill 228 is cut, and the thickness dimension of this protrusion part is processed. The wrap 203 is formed with a predetermined dimension. Thereafter, as shown in FIG. 14B, the chamfered portion 225 is formed obliquely by cutting the edge portion of the tip of the protruding portion by the chamfering cover 231.

The conventional end mill for scroll wrap processing is made of conventional tool steel or cemented carbide, as shown in FIG. 15A, and has an end mill or end mill having a cutting edge 233 having a sharply cut end. The base material 232 was used, and the coating film 234 was applied as shown in FIG. The coating film 234 is made of crystals such as diamond of very high melting point and carbide of various metals.

By the way, in the scroll compressor which combined the fixed scroll 201 and the revolving scroll 202 which have the laps 203a and 203b formed by the above cutting process, the step shape part 224a, 224b as mentioned above is mentioned. Since the chamfered portions 225b and 225a are formed obliquely at the ends of each of the wraps 203b and 203a so as not to come into contact with them, even if the wraps 203a and 203b are very close, these stepped shapes The space | gap 226 which becomes the linear seal which arises between the part 224a and the chamfer 225b, and between the step | shape-shaped part 224 and the chamfer-shaped part 225b becomes large. Usually, the air gap 226 is formed in the oil film of the refrigeration oil contained in the refrigerant gas, and the refrigerant gas is prevented from leaking from the air gap 226 by the actual effect, but as described above, if the air gap 226 is large, the wrap 203a ) And (203b) approaches, the gas pressure of the refrigerant gas between them is large, and the oil film of the refrigeration oil there is easily broken, and the actual effect cannot be exerted. For this reason, if the compressor is normally operated, the refrigerant gas that is continuously compressed leaks out of the void 226 in which the oil film is broken, which causes a decrease in the performance of the compressor. do. Further, in the conventional machining method as described above, since the machining on the lap side and the machining of the chamfer are performed in separate processes, the machining time is naturally long and the machining efficiency is also low. In addition, when executed in a separate process as described above, a step replacement work with tool replacement is required when the process from the lap side processing step to the chamfering process is performed. Position shift between the side mill end mill 228 for cutting the work side surface 230 and the chamfering cutter 231 for cutting the chamfered shape 225 is easy to occur, so that the machining with high dimensional accuracy can be performed. I can't.

US Patent No. 4,470,733 discloses a cutting tool that can be used for various types of cutting operations. At the tip of the cutting tool, two radial cutting edges which are inclined with respect to the axis of the tool are provided, and these cutting edges can be used for drilling and chamfering. Moreover, the side cutting edge which extends in parallel with the axis of a tool from the outer end of these radial cutting edges is also provided, and it is possible to process a groove side etc. using these side cutting edges. However, in the cutting tool described in this US patent specification, since the two radial cutting edges at the tip end are inclined with respect to the axis of the tool, the tip of the tool is pointed like the tip of the drill weight. It is impossible to use as an end mill. Therefore, if this cutting tool is excessively used for the processing of the scroll wrap, as shown in Fig. 14A of the present application, it is only possible to use the chamfer forming portion 225 of the work as a chamfering cutter for cutting. In order to use the cutting tool disclosed in the above U.S. patent as a cutter for chamfering as shown in FIG. 14B of the present application, the end mill 228 is used as shown in FIG. It is absolutely necessary to cut the side surface 230 of the workpiece and the bottom surface 209 of the wrap. Therefore, the cutting tool body disclosed in the above-mentioned US patent does not have a function as an end mill for scroll wrap processing (combination with an end mill is a condition, and in that case, FIGS. 14A and 14B of the present application). The problem of misalignment as described in connection with the above is impossible, and cutting with high dimensional accuracy is impossible).

In the conventional scroll wrap processing end mill 235 described with reference to FIG. 15, as a flat cutter member, the cutting edge is sharp, so chipping is easy. In the coating end mill, the coating film 234 is made of a very high and high melting point crystal such as diamond or carbide of various metals. This is because the material is different from the end mill base material 232 in mechanical and chemical properties. End milling material 232 is difficult to combine. Thus, various researches have been conducted on the surface treatment to promote bonding with the end milling material 232. However, inevitable subtle fluctuations such as temperature and atmosphere occur during the surface treatment and coating process, resulting in end mill base material. The bonding force between 232 and the coating film 234 is very unstable.

As a result, when the cutting of the workpiece is carried out using the end mill base material 232, the cutting edge 233 is sharp, and thus the point of contact with the workpiece is brought into contact with each other. Since the cutting stress is very largely loaded at the tip of the cutting edge 233 in two directions, this cutting stress is very large, causing peeling of the coating film 234 or at the beginning of the cutting of the cutting edge 233. Sudden wear occurred, and it was impossible to secure the desired cutting precision or cutting distance.

SUMMARY OF THE INVENTION An object of the present invention is to provide an end mill for scroll wrap processing, which is capable of shortening the machining time of a fixed scroll and a rotating scroll wrap in a scroll compressor and processing it with high precision.

According to the present invention, an end mill for processing a scroll wrap for cutting a wrap in which a chamfer is formed at a distal end of a fixed scroll and a sun scroll in a scroll compressor, wherein the chamfer cutting edge has a shape corresponding to the shape of the chamfer at the stepped portion. And a second cutting edge extending from the position of the chamfering cutting edge to a cutting edge for lateral processing from the position of the chamfering cutting edge to the tip and a cutting edge for lateral processing as a whole and extending upwardly above the chamfering cutting edge. An end mill for scroll wrap processing is provided. According to the end mill for scroll wrap processing which concerns on this invention, the front-end | tip part of the scroll wrap shape | molded to substantially predetermined dimension is cut by the chamfering cutting edge, and the predetermined chamfer code is formed in the front-end | tip. Moreover, the side surface part of this wrap is cut by the cutting edge for side processing, and the wrap side surface is formed using the thickness of a wrap as a predetermined dimension. In this way, the chamfer portion and the lap side surface of the tip portion of the lap are simultaneously formed, and the positional relationship between the chamfer portion and the lap side surface is precisely defined. In addition, since the cutting powder is removed from the cutting relief portion, cutting processing between the chamfer portion and the wrap side surface is performed well. In addition, according to the end mill for scroll wrap processing according to the present invention, it is possible to simultaneously cut different parts of the lap in a fixed scroll or a swivel scroll, and as a result, it is possible to shorten the processing time and improve the processing efficiency. In addition, the positional relationship, shape, and dimensional accuracy of the machined portion can be improved.

It is still another object of the present invention to provide an end mill for scroll wrap processing in which a desired cutting precision or cutting distance can be secured at all times.

According to the present invention, there is provided an end mill for scroll wrap processing in which a coating film made of an ultra hard material is applied to the surface of an end mill base material which has been precisely finished, and an obtuse chamfer is provided at the tip of the cutting edge of the end mill base material. An end mill for scroll wrap processing is provided on the surface of an end mill base material including a chamfered portion.

According to the end mill for scroll wrap processing according to the present invention, since the cutting edge of the end mill base material is locally obtuse by the chamfer, the contact state between the workpiece and the cutting edge is in line contact and the load stress becomes infinite. Compared to the point contact state, the cutting stress is greatly reduced in two directions on the side and bottom of the blade. Therefore, peeling of the coating film from the end mill base material is eliminated, and abrupt wear at the cutting stage of the cutting edge can be avoided, thereby stabilizing cutting precision and prolonging the life of the tool, thereby improving processing efficiency.

The above objects, configurations, and effects will become more apparent from the following description.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 is a longitudinal sectional view showing the assembling state of the fixed scroll and the revolving scroll in the first embodiment of the scroll compressor machined by the end mill according to the first embodiment of the present invention. ) Is the swivel scroll, (203a), (203b) is the lap, (204a), (204b) is the slab (single plate), (205a), (205b) is the lap root portion, (206a), (206b) is the lap tip , (207a), (207b) is the lap side, (208a), (208b) is the lap top surface, (209a), (209b) is the lap bottom surface, (210a), (210a) is the lap source R chamfer, ( 211a) and 211b are lap tip R chamfered portions.

In the same figure, the fixed scroll 201 is arrange | positioned at the upper part and the turning scroll 202 is arrange | positioned at the lower part, respectively. The fixed scroll 201 is composed of a disc-shaped hard plate 204a and a wrap 203a protruding from the wrap bottom surface 209a, which is its surface, to the swing scroll 202 side, and the swing scroll 202 also has a disc shape. It consists of the wrap board 203b which protruded toward the fixed scroll 201 side by the hard plate 204b and the wrap bottom surface 209b which is its surface. Although not shown here, as is well known, the wrap 203a forms a swirl, and the wrap 203b is also sandwiched between the wraps 203a to form a swirl.

At the lap tip 206a of the wrap 203a, its lap top face 208a is parallel and very close to the lap bottom face 209b of the turning scroll 202, and similarly at the lap tip 206b of the wrap 203b. Its wrap top face 208b is parallel and very close to the wrap bottom face 209a of the fixed scroll 201. The swinging scroll 202 rotates about the central axis (not shown) with respect to the fixed scroll 201, but the gap between the lap top surface 208a and the lap bottom surface 209b remains constant regardless of the pivoting movement. The gap between the lap top face 208b and the lap bottom face 209a is kept constant. The gap between the lap side surfaces 207a and 207b of the laps 203a and 203b changes with this turning movement, but these lap side surfaces 207a and 207b are always kept in parallel. .

Lap source R chamfers 210a are provided on both sides of the lap root portion 205a of the lap 203a protruding from the lap bottom surface 209a of the fixed scroll 101, and the lap tip portion 206a is also provided. The lap tip R chamfer 211a is provided at both sides. Similarly, on both sides of the lap root portion 205b of the lap 203b projecting from the lap bottom surface 209b of the turning scroll 202, a lap root R chamfer 210b is provided, and the lap tip 206b is also provided. Lap tip R chamfers 211b are provided on both sides.

FIG. 2 is an enlarged cross-sectional view of portions of the lap tip portion 206a of the lap 203a and the lap root portion 205b of the lap 203b in FIG.

In the same drawing, the lap source R chamfer 210b of the lap 203b forms part of a circle of radius r in contact with the lap side surface 207b and the lap bottom surface 209b perpendicular to the lap side surface 207b. ) And the wrap bottom surface 209b. The lap tip R chamfer 211a of the lap 203a has a radius r 'which is slightly smaller than the radius r to form a part of the circle having the same center as the circle of the radius r, and the lap side surface 207a and the lap top surface 208a. Although it is smoothly continuous, the lateral side 207a and the lap end of the straight portion 212 in the connecting direction of the lap end R chamfer 211a are arranged for the arbitrary angle θ of the lap side 207a and 15 ° or less. It is provided between R chamfer 211a. The linear part 212 is provided in order to suppress the generation | occurrence | production of the burr by the extreme step and the cutting at the time of the process of the wrap 203a, 203b as mentioned later. The same applies to the lap root portion 205a of the lap 203a and the lap tip portion 206b of the lap 203b.

3 shows one specific example of the cutting processing method of the lap source R chamfers 210a, 210b and the lap end R chamfers 211a, 211b of the laps 203a, 203b. In the following, since the cutting method is the same for the wraps 203a and 203b, the descriptions of the symbols a and b are omitted from the symbols.

3 is a diagram showing a state in which the wrap side surface 207 and the bottom surface 208 are simultaneously processed by the rough machining end mill 215. As a result, a wrap 203 slightly thicker than the specified thickness is formed. FIG. 3B is a view showing a state in which the lap top surface 208 and the lap end R chamfer 211 are simultaneously cut by the R chamfer cutter 214. The R chamfer cutter 214 has a radius r 'and It has a gross shape with arbitrary angle (theta) at the tangent line. As a result, a comparative lap linear portion 212 is formed between the lap tip R chamfer portion 211 and the lap side surface 207. Since the portion forming the angle θ with the lap side 207 of the blade of the R chamfering cutter 214 is actually longer than the portion for cutting the lap 203, the formed lap tip R chamfer 211 and the lap side 207 It is possible to suppress generation of burrs due to cutting without generating a step in between. FIG. 3C shows the lap side surface 207a and the lap bottom surface 209a at the same time by the finishing end mill 213 which added the circular arc of the radius r corresponding to the lap origin R chamfer 210 at the front-end. It is a figure which shows the situation. This cutting process removes the straight portion 212 of the angle θ from the lap end R chamfer 211 formed in the process shown in FIG. 3B, but the chamfer cutter 214 and the finishing end mill ( If the cutting trajectory of 213 is slightly different, this straight portion 212 remains slightly. However, since this is a slight and obtuse angle to the lap side, it is not likely to affect the formation of the oil film of the refrigeration oil.

Since the wrap bottom surface 209 and the side surface 207 are simultaneously processed by one end mill 213 having a small arc at the tip as shown in FIG. 3C, the conventional method described in FIG. As described above, the cutting process can be performed in a short time compared to the cutting method in which the cutting step 224 is formed by performing each cutting process separately, thereby greatly improving the processing efficiency. In addition, when the tip of the end mill is an acute shape, chipping during cutting (a part of the cutting blade is broken) may occur and unevenness of processing precision and processing efficiency may not be necessary, but the end mill 213 shown in FIG. ) Has a small arc at the tip, which can reduce chipping and improve machining accuracy and processing efficiency.

In addition, when the radius r, r 'of the lap origin R chamfer 210 and the lap | tip end R chamfer 211 of the lap 203 is too large with respect to the thickness H of the lap 203 shown in FIG. The planar side formed at the lap top surface 208 and the lap bottom surface 209 cannot be secured, and leakage of refrigerant gas occurs between them, causing deterioration of the performance of the compressor. That is, the relationship between the actual plane width h minus the radius r and r 'from the lap thickness H and the amount of gas leakage increases as the gas h decreases as shown in FIG. Therefore, in the results of experiments in the lap thickness in any range, by reducing the radius r and r 'to 5% or less of the lap thickness H, the gas leakage can be substantially sufficiently suppressed by synergy with the oil film of the refrigerator oil. The performance of the compressor can be secured well.

Thus, in this embodiment, since the wrap circumferential R chamfer 210 is formed in the lap 203, and the lap tip R chamfer 211 is provided in the lap tip 206, Leakage of refrigerant gas can be significantly suppressed as compared with the conventional compressor shown in FIG. 12 while maintaining high mechanical strength.

5 is a longitudinal sectional view showing the assembled state of the fixed scroll and the revolving scroll in the scroll compressor machined according to another embodiment of the present invention, (210a ', 210b') is the lap source reverse chamfer , (211a ') and (211b') are lap tip chamfers, and the same reference numerals are given to the parts corresponding to FIG.

This embodiment is different from the embodiment shown in FIG. 1 in the shape of the chamfer, and since it is the same as the embodiment described in FIG.

In the same drawing, the lap root portion 205a of the lap 203a of the fixed scroll 201 is formed with a straight lap root inverse chamfer 210a 'inclined with respect to the mirror plate 204a, so as to face the lap root portion 205a. Lap tip chamfer in a straight shape that is inclined to the lap end portion 206b of the wrap 203b of the turning scroll 202 with respect to the lap side 207b of the wrap 203b and parallel to the lap root inverse chamfer 210a '. 211b 'is provided. Similarly, the lap root portion 205b of the lap 203b of the turning scroll 202 is formed with a straight lap root inverse chamfer 210b 'inclined with respect to the mirror plate 204b, and is fixed to face the lap root portion 205b. A straight lap chamfer 211a inclined with respect to the lap side 207a of the lap 203a and parallel to the lap root inverse chamfer 210b 'at the lap end 206a of the lap 203a of the scroll 201. ') Is provided.

FIG. 6 is an enlarged cross-sectional view showing portions of the lap root inverse chamfer 210a 'and the lap tip chamfer 211b' in FIG. 5, with the same reference numerals indicating the parts. The explanation will be omitted except for a and b.

As apparent from the above description and FIG. 6, the lap tip chamfer 211 'is parallel to the lap root inverse chamfer 210', and the length of the lap tip chamfer 211 'in the inclined direction is the lap root source. It is slightly shorter than the length in the same direction of the reverse chamfer 210 '. For this reason, when the laps 203a and 203b approach, the spacing between the lan near source reverse chamfer 210 'and the lap tip chamfer 211' is sufficiently small and uniform as a whole. Thus, as in the embodiment shown in FIG. 1, an oil film of the refrigeration oil is easily formed between the lap source reverse chamfer 210 'and the lap end chamfer 211'.

In Fig. 5, the actual plane widths h of the lap top portions 206a and 203b of the laps 203a and 203b are the lap chamfers 211a ', By providing 211b ', the thickness H becomes smaller than the thicknesses H of the wraps 203a and 203b, and the relationship between the actual plane width h and the gas leakage amount is as shown in FIG. Wrap tip chamfers 211a ', 211b', and wrap so that the reduction in real plane width h by (211a '), (211b') is less than 5% of the thickness H of wraps 203a, 203b. By forming the root back chamfers 210a 'and 210b', the lap top surface 208b and the lap top surface 208a and the lap bottom surface 209b are similar to the embodiment shown in FIG. It is easy to form the oil film | membrane of refrigerator oil, respectively between the wrap bottom surfaces 209a, and can suppress that leakage of refrigerant gas is carried out.

Next, the cutting method of the wrap 203 of this embodiment will be described with reference to FIG.

FIG. 7A shows a stepped rough shape in which the lap top surface 208 is previously formed with a rough cut of the lap side surface 207 of the finished scroll and the lap tip chamfer 211 of the lap tip portion 206 has an inclination angle. It is sectional drawing which shows one example of the state cut | disconnected by the end mill 216 for a process.

FIG. 7B is a finishing end in which the lap tip chamfer 211, the lap side 207, and the lap root inverse chamfer 210 of the lap root 205 have a chamfer shape at the tip. It is a figure which shows one example of the state of cutting using the mill 217. As shown in FIG. In this case, in the machining of the lap side surface 207, the cutting tolerance is adjusted to be equal to or slightly smaller than the lap root inverse chamfer 210 of the lap root 205. In addition, the depth of the lap bottom surface 209 is important for the relative positional relationship with the lap top surface 208, so that the measurement process of height is provided in advance between the process of FIG. 7 a and FIG. ), The final cutting is performed.

Even in such cutting process, if the tip of the end mill 217 has an acute angle, chipping during cutting (that is, a part of the cutting blade is broken) may occur, so that unevenness in processing density and processing efficiency may not be avoided. 217) has a small linear inclination at the tip, thereby suppressing the occurrence of chipping and improving the processing precision and processing efficiency.

As described above, in this embodiment, since the wrap source chamfer 210 and the lap tip chamfer 211 are provided on the wrap 203 inclined in a straight line, the wrap 203 mechanical Leakage of refrigerant gas can be significantly suppressed as compared with the conventional compressor shown in FIG. 22 while maintaining the strength.

8 is an external view showing one embodiment of a scrollwrap end mill according to the present invention, where 218 is a scrollwrap end mill, and 218a1 to 218a4 are side cutting edges, 218b1, 218b2 is a cutting edge for chamfering, and 218c1 and 218c2 are cutting relief portions.

In the same drawing, it is assumed that the end mill 218 for scroll wrap processing is provided with four cutting edges, one of which is the side cutting edge 218a2, the chamfering cutting edge 218b1 using the stepped portion, and these The cutting relief portion 218c1 in between, the cutting edge 218a4 for side processing, the cutting edge 218b2 for chamfering, and the cutting relief portion 218c2 therebetween are respectively cut with high precision. The remaining two cutting edges form the side cutting edges 218a1 and 218a3 as a whole, and have the same dimensions as the side cutting edges 218a2 and 218a4, and are scrolled more than the chamfering cutting edges 218b. The upper end of the cutting edge for chamfering of the end mill 218 for lapping is formed.

The cutting edges provided with the cutting edges 218b1 and 218b2 for chamfering have a stepped portion higher than other cutting edges at the base of the scroll lap end mill 218, so that cutting is performed at a predetermined angle so that cutting edges for chamfering processing ( 218b1 and 218b2 and cutting relief parts 218c1 and 218c2 are formed. In addition, the cutting edges having other functions such as the side cutting edges 218a2 and 218a4 and the chamfering cutting edges 218b1 and 218b2 can obtain stable cutting vibration and cutting ability. It is preferable to provide a center axis of the end mill 218 for scroll wrap processing as an object.

FIG. 9A shows a state in which the chamfered portion 211 of the tip portion 206 of the wrap 203 cuts the wrap side surface 207 by the scroll wrap processing end mill 218. As shown, the lap side 207 is cut by the side cutting edge 218a2 (or the side cutting edge 218a4) of the scroll wrap end mill 218, and the end of the lap tip 206. Although the chamfer 211 is formed by the cutting by the cutting edge 218b1 (or the cutting edge 218b2 for the chamfering) of the end mill 218 for the additional scroll wrap processing, the end mill 218 for the scroll wrap processing is formed at this time. The projection 219 is formed at the boundary between the chamfer 211 and the wrap side surface 207 by the concave cutting relief portion 218c1 (or cutting relief portion 218c2) of the.

However, as the scroll wrap end mill 218 rotates, as shown in FIG. 9B, the wrap side surface 207 is cut by the next side cutting edge 218a1 (or side cutting edge 218a3). If so, the protrusion 219 is also cut and removed.

Thus, according to this embodiment, the positional relationship of the chamfer 211 of the tip part 206 and the lap side surface 207 of the tip part 206 of the lap 203 is formed simultaneously, and is formed, Since is determined by the structure of the end mill 218 for scroll wrap processing, it is set with high precision, and the chamfer of these front-end | tip parts 206 only improves the precision of the position adjustment of one scroll wrap end mill 218. The shape and dimensions of the 211 can be set with high accuracy.

In this embodiment, since the cutting edges 218b1 and 218b2 for chamfering form a straight line, it can be used for cutting the lap 203 as shown in FIG.

However, the cutting edges 218b1 and 218b2 for chamfering processing do not necessarily have to be in a straight line shape, but can be in any shape such as an arc shape. When this shape is made into an arc, it can be used for the cutting of the lap | lap 203 shown in FIG.

10 is an external view showing another embodiment of the end mill for scroll wrap processing according to the present invention, 220 is an end mill base material, 221 is a cutting edge, 222 is a coating end mill, 223 is a coating The part shown by hatching as a film has shown the content.

The end mill base material 220 (FIG. 10a) is made of tool steel, super steel, etc. similarly to the conventional end mill for scroll wrap processing, and is produced by the same precision grinding method as a conventional material. However, the difference from the conventional end mill for scroll wrap processing is the forming method of the cutting edge 221. The end mill base material 220 has an arc shape as shown in Fig. 11A at the tip of the cutting edge 211. A chamfer or a linear chamfer is provided, as shown in FIG.

The coating film 223 is applied to the surface of the end mill base material 220 as shown in FIG. In addition, the coating film 223 is formed with a uniform film thickness on the surface of the end mill base material 220 unless the thickness is extreme. When the coating film 223 is extremely thick, the drop in precision after coating is remarkable, and the strength of the film itself is remarkably lowered, so that it cannot be used as an end mill.

Claims (1)

An end mill for scroll wrap processing for cutting a wrap so that a chamfer is formed at the tip end of a fixed scroll and a revolving scroll in a scroll compressor, and a chamfer cutting edge (218b1, 218b2) having a shape corresponding to the shape of the chamfer at the stepped portion. And a first cutting edge which is a cutting edge 218a2, 218a4 for side processing from the positions of the chamfering cutting edges 218b1, 218b2 to cutting edges 218c1, 218c2, to the tip. An end mill for scroll wrap processing, comprising cutting edges (218a1, 218a3) and having a second cutting edge extending upwardly above the cutting edges (218b1, 218b2) for chamfering.