JP2012035007A - Manufacturing method of knife, knife obtained by the manufacturing method, and small-sized electric apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a knife capable of smoothly performing a series of processes from boring process to grinding process, and improving durability of the knife by eliminating corrosion or break generated in a welded part.SOLUTION: The manufacturing method of the knife includes: a knife body 20; and a knife support body 21 for supporting the knife body 20. The knife performs boring process, pressing process, and welding process on a metal plate material in this order. Heat treatment is performed on the obtained third blank 39 to finish the knife. Grinding process is performed if necessary. Heat treatment is performed after pressing process or welding process. Thus, pressing process can be performed more easily and accurately compared to a case in which heating process is performed in advance. Performing heat treatment improves durability of the knife by preventing stress corrosion or break of the welded part.

Description

  The present invention relates to a method for manufacturing a blade represented by a cutting blade of an electric razor, a blade obtained by the manufacturing method, and a small electric device provided with the blade. The blade according to the present invention is applied to, for example, a rotary electric razor, an inner blade of a hair ball remover, or an inner blade of a reciprocating electric razor.

  Regarding the present invention, it is known to manufacture a reciprocating inner blade as follows (Patent Document 1). There, the blade body and a pair of front and rear support frames fixed to the front and rear edges of the blade body constitute an inner blade having a U-shaped cross section. The blade body is formed by etching a hardened sheet metal piece, and the resulting blade blank is electropolished to sharpen the cutting blade. Finally, a pair of support frames are laser welded to the front and rear edges of the blade body to complete the inner blade.

  In the reciprocating electric razor of Patent Document 2, an inner blade blank is formed by an etching method, and then the inner blade blank is pressed to form an inner blade having an inverted U-shaped cross section.

  The present inventors are conducting research and development for forming an inner blade of a rotary electric razor into a cylindrical bowl shape. The cylindrical bowl-shaped inner blade is composed of a blade holder and three blade bodies welded to the peripheral surface of the blade holder, and has an inner blade structure compared to a conventional rotary inner blade composed of a group of spiral blades. Can be simplified. The blade body for the cylindrical bowl-shaped inner blade is formed by etching the quenched stainless steel plate material to form a primary blank, and then pressing the primary blank to bend the cross section into a partial arc shape. A group of small blades is formed in an expanded metal shape on the obtained blade body, and its peripheral edge and blade surface are spot welded to the blade holder and integrated. The obtained cylindrical bowl-shaped inner blade is ground to sharpen the cutting edge.

Japanese Patent No. 3839046 (paragraph numbers 0065 to 0069, FIG. 6) JP 2000-218630 A (paragraph number 0006, FIG. 2)

  As described above, a conventional blade body for an inner blade is formed by etching a stainless steel plate that has been tempered to form a primary blank, followed by pressing. Therefore, it is inevitable that the hardness of the stainless steel plate increases during the quenching process, and bending performed after the etching process becomes difficult. Further, since the blade body is fixed to the blade holder by spot welding or laser welding, it is inevitable that a welded portion remains. The welded portion can be removed to some extent by grinding, but cannot be completely removed. Therefore, corrosion is generated from the welded portion, or cracks are easily generated around the welded portion due to internal stress at the time of welding, and it is difficult to obtain sufficient durability.

  An object of the present invention is to provide a method for manufacturing a blade capable of improving the durability of the blade by removing corrosion and cracks occurring in the welded portion, a blade obtained by the method, and a small electric device provided with the blade. It is to provide.

  The present invention relates to a method for manufacturing a blade including a blade body 20 and a blade support 21 that supports the blade body 20. The blade is processed on a metal plate material to form a sheet-like first blank 37 to be the blade body 20, and the second blank 38 is pressed into the first blank 37 and bent into a predetermined shape. A blade is manufactured by welding the second blank 38 to the blade support 21 to form a third blank 39 to be a blade, and applying a heat treatment to the third blank 39. .

  In the step of welding the second blank 38 to the blade support 21, the second blank 38 is fixed to the blade support 21 by a group of welded portions 57 that are scattered. The third blank 39 is ground.

  The cross section of the second blank 38 is formed in a partial arc shape, and a pair of arc side portions 22 and a pair of straight side portions 23 are provided on the periphery of the second blank 38. In the process of welding the second blank 38 to the blade support 21, the group of welded portions 57 are arranged on the side of each arc side portion 22 from the center portion of each straight side portion 23 as indicated by reference numerals w1 to w10 in FIG. It forms in order toward.

  In the step of welding the second blank 38 to the blade support 21, the welding position (w 5, w 6, w 9, w 10) of the welding part 57 in the arc side part 22 is changed to the welding position (w 1 of the welding part 57 in the straight side part 23. ˜w4, w7˜w8) are shifted to the center side or the center side of the arc side portion 22 in the width direction.

  In the step of welding the second blank 38 to the blade support 21, the formation position of the welded portion 57 adjacent along the straight side 23 is a position close to the straight side 23 and a position away from the straight side 23. They are alternately formed in a zigzag shape (see FIG. 12).

  The blade is configured in a cylindrical bowl shape by a blade support 21 having a circular blade receiving portion 31 and a blade body 20 circumscribing the circular peripheral surface of the blade receiving portion 31. The radius R1 of the inner surface of the second blank 38 whose section is formed in a partial arc shape is set slightly smaller than the radius R2 of the circular peripheral surface of the blade receiving portion 31. In the process of welding the second blank 38 to the blade support 21, the second blank 38 is elastically deformed with a jig as shown in FIG. 7 so that the inner surface of the second blank 38 becomes the circular peripheral surface of the blade receiving portion 31. The second blank 38 is welded while maintaining this tightly held state.

  The blade of the present invention is composed of a blade obtained by the above manufacturing method.

  The above-mentioned blade is applied to a small electric device that cuts the object to be cut by rotationally driving the blade with motors 12 and 70.

  In the manufacturing method of the present invention, the metal plate material is subjected to perforating processing such as etching and punching, and then subjected to press working to form the second blank 38, and the second blank 38 is welded to the blade support 21. After that, heat treatment was performed. As described above, when heat treatment (quenching) is performed after press working, the first blank 37 in a soft state that has not been heat treated can be pressed, and thus the second blank 38 can be processed easily and accurately. In addition, by applying heat treatment to the third blank 39 that is integrated by welding the second blank and the blade support 21, the stress corrosion and cracking of the welded portion can be prevented while enhancing the hardness, and the durability of the blade is improved. it can.

  Further, in the process of grinding the blade after heat treatment, the surface of the blade body 20 is finished and at the same time, if the bulging surface of the group of welded portions 57 is ground, the corrugated uneven surface of the welded portion 57 can be surely corroded. By removing it, the strength of the welded portion 57 can be improved by reliably preventing corrosion and cracking during long-term use. Therefore, the durability of the cutter can be improved while smoothly performing a series of processes from etching to grinding.

  In the step of welding the second blank 38, if a group of welded portions 57 are formed in order from the central portion of each linear side portion 23 toward the respective arc side portions 22, welding distortion is caused from the center of the blade body 20 to the arc side. It can be fixed while escaping in order toward the portion 22 side. Therefore, the variation in the roundness of the peripheral surface can be reduced by fixing the blade body 20 in close contact with the blade support 21. When grinding is performed thereafter, the labor and time required for the grinding process can be saved by the small variation in roundness, and the cutting cost of the blade can be reduced.

  In the step of welding the second blank 38 to the blade support 21, the welding position (w 5, w 6, w 9, w 10) of the welding part 57 in the arc side part 22 is changed to the welding position (w 1 of the welding part 57 in the straight side part 23. ~ W4, w7 ~ w8) and forming the third blank 39 that can prevent the blade body 20 from being distorted during the heat treatment step if it is shifted to the center or the center of the arc side portion 22 in the width direction. can do.

  If the welding part 57 adjacent along the linear side part 23 is formed in zigzag shape, the 3rd blank 39 which can prevent distortion of the blade main body 20 in the case of a heat treatment process can be formed.

  When the radius R1 of the inner surface of the second blank 38 is set slightly smaller than the radius R2 of the circular peripheral surface of the blade receiving portion 31, and the second blank 38 is elastically deformed by a jig, the second blank at the time of welding is used. The entire inner surface of 38 can be forcibly adhered to the peripheral surface of the blade receiving portion 31. Therefore, even if there is a variation in the shape of the second blank 38 in the pressing step, the second blank 38 can be welded in an appropriate state in which the entire inner surface of the second blank 38 is in close contact with the peripheral surface of the blade receiving portion 31, and is obtained by welding. The variation in the external dimensions of the three blanks 39, for example, the width of the variation in roundness can be reduced.

  According to the blade obtained by the above-described manufacturing method, the entire structure of the blade can be simplified and the manufacturing cost can be reduced compared to a conventional blade using a spiral blade as a cutting element, and the cost can be provided correspondingly. Furthermore, in the process of performing the heat treatment, it is possible to prevent stress corrosion and cracking of the welded portion while increasing the hardness, so that it is possible to provide a blade having excellent durability.

  According to the small electric device provided with the blade according to the present invention, the cutting object such as a beard, a hairball, or a nail can be effectively cut by rotating or reciprocating the blade with motor power. Processing can be performed efficiently.

It is a top view which shows the fixing structure of the blade main body which concerns on this invention. It is a front view of an electric razor. It is a vertical side view in the head part of an electric razor. It is a disassembled perspective view of an inner blade. It is a top view of the 1st blank in an etching process. It is a side view which shows the processing state of the 2nd blank in a press process. It is a longitudinal cross-sectional view which shows the process of welding of a 2nd blank. It is a longitudinal cross-sectional view which shows the structure of a welding part, and the finishing state in a grinding | polishing process. It is the front view of the completed inner blade, and principal part sectional drawing. It is a disassembled perspective view which shows another Example of an inner blade. It is explanatory drawing which shows the molding condition of the 2nd blank which concerns on FIG. It is a top view which shows another Example of a welding form. It is a front view which shows another example of application of an inner blade. It is a front view which shows another example of application of an inner blade. It is a front view which shows another example of application of an inner blade. It is a front view which shows another example of application of an inner blade. It is a disassembled perspective view which applied this invention to the reciprocating type inner blade. It is a front view which shows the welding form of the inner blade which concerns on FIG. It is sectional drawing which shows another processing form of a blade main body.

(Example) FIG. 1 thru | or FIG. 9 shows the Example which applied the blade which concerns on this invention to the inner blade of a rotary electric shaver. In FIG. 2, the electric razor includes a main body portion 1, a head portion 2 supported by the main body portion 1, an outer frame 3 attached to the main body portion 1, and a shaving unit ( (Not shown). The outer frame 3 is provided in order to improve the decorativeness, and constitutes a grip in cooperation with the main body 1. On one side upper part of the outer frame 3, a switch button 4 for turning on / off the energization state of the motor 12 is provided.

  A secondary battery 5 and a circuit board 6 are incorporated in the main body 1. The circuit board 6 is mounted with a switch that can be switched by the previous switch button 4, an LED for the indicator lamp 7, and electronic components that constitute a control circuit and a power supply circuit.

  The head portion 2 is provided with a main blade including an outer blade 10 and an inner blade (blade) 11 that rotates in one direction around the horizontal axis. Further, a motor 12 that rotationally drives the inner blade 11, and a motor 12 A driving structure for transmitting the rotational power to the inner blade 11 is provided. The inner blade 11 according to the present invention is replaced with a rotary blade or a blade according to the difference in the embodiments, but all mean the same member. The motor 12 is fixed to the lower surface of the head frame 15 and accommodated on the upper inner surface of the main body 1. The drive structure is composed of a group of gear trains 13, which converts the rotational power around the vertical axis of the motor 12 into rotational power around the horizontal axis and transmits it to the inner blade 11. The inner blade 11 rotates in a direction (counterclockwise) indicated by an arrow in FIG. The outer blade 10 is composed of a sheet-like mesh blade formed by an etching method or an electroforming method, and its front and rear edges are supported by the outer blade holder 14 and retained in an inverted U shape (see FIG. 3). ). FIG. 3 shows an outer blade 10 formed by electroforming. Reference numeral 17 denotes a cutting blade of the outer blade 10. The head portion 2 is supported by the main body portion 1 so as to be movable up and down, and the space between the two is sealed with a waterproof packing.

  The outer blade holder 14 is detachably attached to the head frame 15, and is locked so as not to be separated by a lock structure (not shown). When the pair of left and right lock release buttons 16 provided on the head frame 15 are pushed in at the same time, the engagement by the lock structure is released, and the outer blade holder 14 can be removed from the head frame 15 to expose the inner blade 11. . In this state, the upper surface of the head frame 15 and the hair adhering to the inner blade 11 can be washed with water.

  3 and 4, the inner blade 11 is configured in a cylindrical bowl shape by three blade main bodies 20 and a blade support 21 that supports the blade main body 20. The blade body 20 is basically formed by etching a stainless steel plate (metal plate) and further pressing it to form a partial arc shape in cross section. Details of the manufacturing method of the inner blade 11 will be described again. As shown in FIG. 4, a peripheral edge of the blade body 20 formed in a partial arc shape is provided with a pair of arc side portions 22 and a pair of straight side portions 23.

  As shown in FIG. 1, the face wall of the blade body 20 has a group of first blades 25, a group of second blades 26, a group of rhombus blade holes 27 surrounded by both blades 25, 26, A peripheral frame 28 surrounding these is formed. A group of the first blades 25 and a group of the second blades 26 are formed so as to be inclined in directions opposite to each other with respect to the rotation center axis of the inner blade 11. Has an expanded metal appearance. The adjacent pitch between the first blade 25 and the second blade 26 was approximately 2.5 mm.

  As shown in FIG. 1, the inclination angle θ1 of the first blade 25 is inclined 13.4 degrees with respect to the rotation center axis of the inner blade 11, whereas the inclination angle θ2 of the second blade 26 is The blade is inclined 23.4 degrees with respect to the rotation center axis of the inner blade 11, and the peripheral ends of the small blades 25 and 26 are continuous with the peripheral frame 28. Whereas the first small blade 25 is formed continuously in a straight rib shape, the second small blade 26 connects the adjacent first small blades 25 in a stepped manner, whereby the second small blade 25 All of the intersections of the 26 first cutter blades 25 have a three-way shape.

  As described above, when a group of the first small blades 25 and a group of the second small blades 26 are provided in an expanded metal shape on the sheet surface of the blade body 20, as compared with a conventional inner blade having a spiral blade as a cutting element. The total length of the cutting blades can be increased, and the cutting blades 25 and 26 having different inclination directions can be cut alternately while generating comb hairs. Furthermore, since the opening area of the blade hole 27 is significantly larger than that of a conventional inner blade having a mesh blade structure, the whisker can be cut by effectively introducing a beard similarly to the inner blade having a spiral blade as a cutting element. Can be performed effectively.

  In FIG. 4, the blade support 21 protrudes sideways from the five blade receiving portions 31, the concave curved surface 32 formed between the adjacent blade receiving portions 31, and the center of the side surface of the blade receiving portion 31 at both ends. It consists of a metal turning product integrally provided with the inner cutter shaft 33 provided. The peripheral surfaces of the blade receiving portion 31 and the inner blade shaft 33 are ground and finished smoothly. An inner blade gear 34 that meshes with the final gear of the gear train 13 is fixed to one shaft end of the inner blade shaft 33 (see FIG. 2). The radius R1 of the inner surface of the blade body 20 described above is set slightly smaller than the radius R2 of the circular circumferential surface of the blade receiving portion 31 (see FIG. 7). The meaning will be described later.

  Next, the detail of the manufacturing method of the inner blade 11 is demonstrated. The inner blade 11 is formed by subjecting a stainless steel plate (metal plate), which is a raw material not subjected to heat treatment (quenching), to a punching process such as etching or punching, in this embodiment, a punching process by etching. A step of forming the first blank 37 (etching step), a step of pressing the first blank 37 to form the second blank 38 bent into a partial arc shape (pressing step), and thereafter The second blank 38 that is still in a raw material state that has not been subjected to heat treatment (quenching) is welded to the blade support 21 that is also a raw material that has not been subjected to heat treatment (quenching). Forming the third blank 39 (welding step), applying a heat treatment to the third blank 39 (heat treatment step), and grinding the third blank 39 after the heat treatment. To form through the process (grinding process) to form a cutting edge 47. Details of each step will be described below.

(Etching process)
In the etching step, the front and back surfaces of the stainless steel plate 36 having a thickness of 0.3 mm are etched to form the first small blade 25 and the second small blade 26 shown in FIG. In addition, the point which etches with the state (raw material) of the raw material marketed, without performing heat processing to a stainless steel board material differs greatly from the conventional manufacturing method. The first small blade 25 and the second small blade 26 have a cut surface 43 on the outer surface, a non-cut surface 44 on the inner surface, a first turning surface 45 formed between the edges of both 43 and 44, and a second surface. It is formed in the odd-shaped cross section provided with the five corners with the turning surface 46. The first turning surface 45 is formed by a single indented surface extending between the edges of the cutting surface 43 and the non-cutting surface 44, whereas the second turning surface 46 is not cut with the cutting surface 43. It is formed of two inner concave surfaces that are shaped like a letter between the edges of the surface 44. The cutting surface 43 and the first turning surface 45 form a cutting blade 47 having a small cutting edge angle on the upper side in the rotational direction of the first small blade 25 and the second small blade 26, and a relief edge 48 on the lower side in the rotational direction. Is formed. As shown in FIG. 5, in the etching process, a large number of first blanks 37 can be simultaneously formed, and the bridging portions 49 provided on the short sides thereof can be cut and separated from the stainless steel plate. .

(Pressing process)
As shown in FIG. 6, in the pressing step, the first blank 37 is bent into a partial arc shape using the fixed mold 51 and the movable mold 52 to form the second blank 38. At this time, the 2nd blank 38 is bent so that the radius of the inner surface may become R1 explained previously. As shown in FIG. 4, the obtained second blank 38 includes a pair of arc sides 22 and a pair of straight sides 23 that are sufficiently longer than the arc sides 22. Is equal to the left and right lengths of the blade receiving portions 31 at both ends. In this way, by pressing the soft first blank 37 that has not been heat-treated, the width of the shape variation due to the springback that cannot be avoided in the heat-treated material is reduced, and the first blank 37 is bent. It can be done easily and reliably.

(Welding process)
In the welding process, as shown in FIG. 7A, the three second blanks 38 are positioned by being applied to the blade receiving portion 31 of the blade support 21 made of stainless steel (metal material). Specifically, the peripheral surfaces of the three second blanks 38 are held and elastically deformed by the partial arc-shaped jig 55 divided into three parts, and the inner surface of the second blank 38 is the peripheral surface of the blade receiving portion 31. Keep in close contact with. In this state, the straight side 23 and the arc side 22 of the second blank 38 are welded by the laser welding machine 56 (FIG. 7B). As described above, when welding is performed in a state where the second blank 38 is in close contact with the peripheral surface of the blade receiving portion 31 against the deformation stress, the second blank 38 is affected by variations in the shape of the second blank 38 in the pressing process. Without any problem, the entire inner surface of the second blank 38 during welding can be brought into close contact with the peripheral surface of the blade receiving portion 31. Therefore, the width of the variation in roundness of the blade body 20 in the third blank 39 after welding can be reduced. By performing welding with the laser welding machine 56, as shown in FIG. 8A, a welded portion 57 that rises outwardly from the peripheral surface of the blade body 20 is formed.

  When the welding process is performed, the welded portion 57 is heated to 2000 ° C. and melted in a very short time, and as shown in FIG. 8, the melted portion reaches the inside wall of the blade receiving portion 31. It solidifies in a state where the molten parts are mixed together. At this time, as indicated by reference numerals w1 to w10 in FIG. 1, the blade main body 20 is welded by forming the group of welded portions 57 sequentially from the center of the linear side portion 23 toward the arc side portion 22 side. It is possible to prevent the blade main body 20 from coming into close contact with the blade receiving portion 31 by preventing the floating from the peripheral surface of the blade receiving portion 31 due to internal stress. Moreover, when the welding part (w1-w8) of the welding part 57 was provided on the linear side part 23, it was in the state which the straight piece part 23 of the blade main body 20 distorted and waved in the case of the subsequent heat processing process. . Therefore, in this embodiment, the welding position (w5 · w6 · w9 · w10) of the welding portion 57 in the arc side portion 22 is set to be greater than the welding position (w1 to w4, w7 to w8) of the welding portion 57 in the linear side portion 23. The distortion of the blade body 20 during the subsequent heat treatment step is performed by positioning the arc side portion 22 near the center in the width direction or a position shifted from the straight side portion 23 toward the center side in the width direction of the arc side portion 22. It is possible to form a cylindrical blank-shaped third blank 39 that can prevent the above. A difference in position between the welding position of the welded portion 57 in the straight side portion 23 and the welding position of the welded portion 57 in the arc side portion 22 is indicated by an arrow a in FIG. Thus, in the process of welding the second blank 38 to the blade support 21, the second blank 38 is fixed to the blade support 21 by the group of welded portions 57 that are scattered, and the welded portion 57 is the second portion. The second blank 38 has a cross section formed in a partial arc shape on the surface to be the cut surface 43 of the blank 38, and a pair of arc side portions 22 and a pair of straight side portions 23 are formed on the periphery of the second blank 38. In the step of welding the second blank 38 to the blade support 21, the welding position (w 5, w 6, w 9, w 10) of the welded portion 57 in the arc side portion 22 is changed to the welded portion in the straight side portion 23. The distortion of the blade body 20 during the heat treatment process is prevented by being shifted from the welding position (w1 to w4, w7 to w8) 57 toward the center of the arc side portion 22 in the width direction or to the center side. Cylindrical bowl-shaped It can form a 3 blanks 39.

  The welding pattern for forming the group of welded portions 57 in order from the central portion of the straight side portion 23 toward the arc side portion 22 is not limited to the above-described welding pattern, and the following welding pattern 2 and welding This can be done with pattern 3. When the welding position codes shown in FIG. 1 are referred to as (w1 to w10), in the welding pattern 2, the welded portion 57 is formed in the order of w1, w3, w5, w7, w9, w2, w4, w6, w8, and w10. Further, in the welding pattern 3, the welded portion 57 is formed in the order of w1, w3, w5, w2, w4, w6, w7, w9, w8, and w10. Since a welding pattern should be changed also by the change of the total number of the welding parts 57, welding patterns other than the welding patterns 1-3 may be employ | adopted. In short, by welding sequentially from the central portion of the straight side portion 23 toward the arc side portion 22, it is possible to prevent the blade body 20 from being lifted off from the peripheral surface of the blade receiving portion 31 due to internal stress during welding. Any welding pattern may be used.

(Heat treatment process)
In the heat treatment step, the cylindrical bowl-shaped third blank 39 is heated to about 1000 ° C., and after maintaining the state for a predetermined time, quenching is performed by sequentially cooling with water and heated oil. Thereby, the metal structure of the blade body 20 is martensitic, and the hardness thereof is enhanced. In the process of heating the third blank 39, it is possible to remove the internal distortion caused by the heat generated around the welded portion 57 during laser welding.

(Grinding process)
In the grinding process, rough grinding and finish grinding are sequentially performed on the peripheral surface of the cylindrical bowl-shaped third blank 39 to improve the roundness of the peripheral surface of the blade body 20 and further sharpen the cutting edge 47. Finish. In the rough grinding process, as shown in FIG. 8B, the bulging surface of the welded portion 57 is removed, and at the same time, the peripheral surface of the blade body 20 is ground. Further, in the finish grinding process, finish grinding is performed so that the surface roughness of the peripheral surface of the blade body 20 is reduced, and the diameter dimension, roundness, and surface roughness of the outer peripheral surface of the inner blade 11 are in a predetermined state. Finish. If the required specification for the roundness of the inner cutter 11 is low, the grinding step can be omitted.

  In this way, by performing heat treatment (quenching) after press working, the first blank 37 in a soft state that has not been heat treated can be pressed, so that the second blank 38 can be processed easily and accurately. Further, the hardness is obtained by applying heat treatment to the third blank 39 in which the second blank that has not been heat-treated (quenched) and the blade support 21 that has not been heat-treated are integrated by welding. It is possible to prevent stress corrosion and cracking of the welded part while enhancing the strength of the blade and improve the durability of the blade.

The inner blade 11 obtained through a series of manufacturing steps is shown in FIG. Between the blade body 20 and the blade support 21, a fouling storage space 59 in a state where the concave curved surface 32 is rotated around the inner blade shaft 33 is formed. As described above, according to the inner blade 11 provided with the fluff storage space 59 inside the blade body 20, the cut fluff is dropped below the inner surface of the inner blade 11, and further, the blade hole having a large opening area. 27 can be quickly dropped into the fuzz chamber. Moreover, at the time of cleaning with water, the chips that have entered the blade body 20 are discharged together with the cleaning water, so that the chips remain on the concave curved surface 32 and the inner surface of the blade body 20, and the hygienic state is always maintained. Can be maintained. According to the inner blade of the present invention described above, a series of processes such as etching, pressing, welding, and heat treatment can be smoothly performed, and the durability of the blade can be eliminated by eliminating corrosion and cracking of the welded part. Can be improved.

The etching process described above can be changed to a pressing process. That is, as shown in FIGS. 19A to 19C, punching is performed by punching a stainless steel plate (metal plate) 82 that is a raw material that has not been subjected to heat treatment (quenching). A blank 83 is formed as shown in FIG. The blank 83 is formed with a blade hole 27 and a front body 84 of the small blade 25 having a square cross section. Next, the blank 83 is subjected to plastic working, and as shown in FIG. 19 (c), the front body 84 is divided into an outer cut surface 43, an inner non-cut surface 44, and the edges of both 43 and 44. A small blade 25 having an acute angle cutting edge 47 and a relief edge 48 is formed by forming a cup shape in cross section by the first and second surface 45 and 46 formed therebetween. Thereby, the 1st blank 37 provided with the some small blade 25 is obtained. Next, as shown in FIG. 19 (d), the first blank 37 is pressed, and the second blank 38, which is plastically deformed into an outwardly curved shape (circular arc shape with the same circumferential curvature), is formed. Form. The width center of the non-cut surface 44 is offset by a dimension T from the width center of the cut surface 43 toward the second turned surface 46. That is, since the center of the width of the non-cutting surface 44 is shifted from the center of the width of the cutting surface 43 to the lower side in the rotation direction, the cutting edge angle θ1 of the cutting edge 47 is formed smaller than the edge angle θ2 of the relief edge 48. Sharpness can be sharpened. Hereinafter, in the same manner as described above, the second blank 38 in a raw material state that has not been subjected to heat treatment (quenching) after that, the blade support that is also a raw material that has not been subjected to heat treatment (quenching). 21, forming a third blank 39 to be the inner blade 11 (welding step), applying a heat treatment to the third blank 39 (heat treatment step), and applying the heat-treated third blank 39 to the third blank 39 It forms through the process (grinding process) which forms the cutting blade 47 by grinding.

Also in the embodiment of this pressing step, as in the etching step, a large number of first blanks 37 are formed at the same time, and the bridging portion 49 provided on the short side portion is cut, and the stainless steel plate material is used. Can be separated.

  FIG. 10 shows another embodiment of the inner blade according to the present invention. In this case, the inner blade 11 is constituted by a single blade body 20 and a blade support 21 in a cylindrical bowl shape. The inner blade 11 can be formed by using a stainless steel plate material as a raw material through the same processing steps as the inner blade described above. However, in the pressing step, the first blank 37 subjected to the etching process is formed into a cylindrical shape by the roll forming machine shown in FIGS. 11A and 11B to form the second blank 38. The roll forming machine includes a pair of receiving rolls 61 and 61 that receive the outer peripheral surface of the second blank 38, and a presser roll 62 that applies a bending force to the inner peripheral surface of the second blank 38. When rotating in the clockwise direction, the presser roll 62 is rotated in the counterclockwise direction. The obtained second blank 38 is welded to the blade support 21 in a state of being held in a perfect circle by a jig (not shown) to form a third blank 39. Since others are the same as the previous embodiment, the same reference numerals are assigned to the same members, and descriptions thereof are omitted. The same applies to the following embodiments.

  FIG. 12 shows another embodiment in which the procedure for forming the welded portion 57 of the second blank 38 in the welding process is changed. In this case, when the second blank 38 is welded to the blade receiving portion 31 of the blade support 21, the formation position of the welded portion 57 adjacent along the straight side portion 23 is set to a position close to the straight side portion 23 and a straight line. Zigzags are alternately formed at positions away from the side. The difference in the welding position of the welding part 57 arrange | positioned at a zigzag is shown by the arrow a. Also in this case, as indicated by reference numerals w <b> 1 to w <b> 10, the welded portion 57 is formed in order from the central portion of the straight side portion 23 toward the arc side portion 22. In this embodiment, welds 57 are formed at the four corners of the second blank 38 to prevent the corners from floating away from the blade receiving portion 31.

  FIG. 13 shows another embodiment of an electric razor. In this case, a guard body 65 for restricting the amount of biting of the rotary blade 11 is provided around the rotary blade (blade) 11 so that both 11 and 65 are rotated by motor power. The guard body 65 is formed in a coil spring shape, and the coil portion is wound around the circumferential surface of the rotary blade 11, and both ends thereof are fixed to the rotary blade 11. Thus, the inner blade 11 of the present invention can be applied to an electric razor that does not include an outer blade.

  14 to 16 show an embodiment in which the rotary blade (blade) 11 is applied to a small electric device other than an electric razor. FIG. 14 shows an embodiment in which the rotary blade 11 is applied to nail cutting. The nail clipper is housed in the main body 68 by providing a cylindrical head portion 69 at one end of the main body 68 that also serves as a grip, and a rotating blade 11 that rotates around the cylinder axis of the head 69. The rotary blade 11 is driven to rotate by the motor 70. Reference numeral 72 is a secondary battery, and reference numeral 73 is a switch button for starting or stopping the motor 70. A semicircular cutting window 71 is opened in the cylindrical peripheral wall of the head portion 69, and the rotary blade 11 is exposed to the outer surface of the head portion 69 through the window 71. In the case of cutting the nail, the rotary blade 11 that is rotationally driven is pressed against the tip of the nail, and the nail is scraped off little by little.

  FIG. 15 shows an embodiment in which the inner blade 11 is applied to a blade for a hair ball remover. The fluff remover is provided with a cylindrical head portion 69 at one end of a main body portion 68 that also serves as a grip, and a blade 11 that rotates about the cylinder axis of the head portion 69 is disposed therein and accommodated in the main body portion 68. The blade 11 is driven to rotate by the motor 70. Reference numeral 72 is a secondary battery, and reference numeral 73 is a switch button for starting or stopping the motor 70. A partial arc-shaped cutting window 71 is opened in the cylindrical peripheral wall of the head portion 69, and the outer blade 10 is exposed to the outer surface of the head portion 69 through the window 71. The fluff is introduced from the blade hole of the outer blade 10 and cut by the cutter 11 that is in sliding contact with the inner surface of the outer blade 10. In this case, the outer blade 10 and the blade 11 are sufficiently longer in the axial center direction than the nail clipper blade 11, and therefore the contact area of the blade 11 with respect to the knit fabric is increased, and the hair is cut. Balls can be removed effectively.

  FIG. 16 shows an embodiment in which the inner blade 11 is applied to a cutlery for a keratin remover. The keratin remover is provided with an arch-shaped head portion 69 at one end of a main body portion 68 that also serves as a grip, and a blade 11 that rotates about an axis orthogonal to the central axis of the main body portion 68 is disposed inside the main body portion 68. The blade 11 is driven to rotate by the motor 70 accommodated in the container. Reference numeral 72 is a secondary battery, and reference numeral 73 is a switch button for starting or stopping the motor 70. A cutting window 71 is notched in the peripheral wall of the head portion 69, and the blade 11 is exposed to the outer surface of the head portion 69 through the window 71. When removing the stratum corneum, the blade 11 in a rotationally driven state is pressed against a stratum corneum such as a heel, and the stratum corneum is scraped off little by little.

  17 and 18 show an embodiment in which the inner blade 11 according to the present invention is applied to an inner blade of a reciprocating electric razor. There, the first blank 37 that has been subjected to etching is pressed to form a second blank 38 that is bent in an inverted U shape, and the resulting second blank 38 is made of die-casting (made of metal ) To the inner blade holder (blade support) 21 to form a third blank 39. The inner blade holder 21 is integrally provided with a blade receiving portion 31 that supports the inverted U-shaped arc side portion 22 of the second blank 38 and a front and rear wall 75 to which the linear side portion 23 of the second blank 38 is welded. Yes. The welded portion 57 in this case was formed in order from the center of the straight side portion 23 toward the arc side portion 22 as indicated by reference numerals w1 to w8. Of the codes indicating the welding order, odd numbers correspond to the welding position of the front wall 75 of the inner blade holder 21, and even numbers correspond to the welding position of the rear wall 75 of the inner blade holder 21.

  Other than the above embodiment, the first blade 25 and the second blade 26 do not need to be formed in a straight line, and can be formed in a meandering shape or a lightning bolt shape. The first blank 37 of the blade body 20 is preferably formed by etching, but can be formed by electroforming if necessary. When the inner blade 11 is composed of a plurality of blade main bodies 20 and blade supports 21, the circumferential lengths of the respective blade main bodies 20 are not necessarily the same.

10 Outer blades 11 Inner blades (Rotating blades, blades)
20 Blade body 21 Blade support 22 Arc side portion 23 Linear side portion 25 First small blade 26 Second small blade 27 Blade hole 31 Blade receiving portion 32 Concave surface 37 First blank 38 Second blank 39 Third blank 47 Cutting blade

Claims (8)

A blade manufacturing method comprising a blade body (20) and a blade support (21) that supports the blade body (20),
Processing the metal plate to form a sheet-like first blank (37) to be the blade body (20);
Pressing the first blank (37) to form a second blank (38) bent into a predetermined shape;
Welding the second blank (38) to the blade support (21) to form a third blank (39) serving as a blade;
A method for manufacturing a blade including a step of performing a heat treatment on the third blank (39). Including the step of grinding after the step of applying heat treatment,
In the step of welding the second blank (38) to the blade support (21), the second blank (38) is fixed to the blade support (21) by a group of welded portions (57) scattered,
The welds (57) are interspersed on the surface to be the cut surface (43) of the second blank (38),
The blade manufacturing method according to claim 1, wherein the bulging surfaces of the group of welds (57) are ground and removed. In the step of welding the second blank (38) to the blade support (21), the second blank (38) is fixed to the blade support (21) by a group of welded portions (57) scattered,
The welds (57) are interspersed on the surface to be the cut surface (43) of the second blank (38),
The cross section of the second blank (38) is formed in a partial arc shape, and a pair of arc sides (22) and a pair of straight sides (23) are provided on the periphery of the second blank (38),
In the step of welding the second blank (38) to the blade support (21), the group of welds (57) are directed from the center of each straight side (23) to the side of each arc side (22). The blade manufacturing method according to claim 1, wherein the blade is formed in order. In the step of welding the second blank (38) to the blade support (21), the second blank (38) is fixed to the blade support (21) by a group of welded portions (57) scattered,
The welds (57) are interspersed on the surface to be the cut surface (43) of the second blank (38),
The cross section of the second blank (38) is formed in a partial arc shape, and a pair of arc sides (22) and a pair of straight sides (23) are provided on the periphery of the second blank (38),
In the step of welding the second blank (38) to the blade support (21), the welding position (w5 · w6 · w9 · w10) of the welded portion (57) in the arc side portion (22) is changed to the straight side portion (23). 4) is shifted from the welding position (w1 to w4, w7 to w8) of the welded portion (57) in the width direction center or the center side of the arc side portion (22). Manufacturing method In the step of welding the second blank (38) to the blade support (21), the second blank (38) is fixed to the blade support (21) by a group of welded portions (57) scattered,
The welds (57) are interspersed on the surface to be the cut surface (43) of the second blank (38),
The cross section of the second blank (38) is formed in a partial arc shape, and a pair of arc sides (22) and a pair of straight sides (23) are provided on the periphery of the second blank (38),
In the step of welding the second blank (38) to the blade support (21), the formation position of the welded portion (57) adjacent along the straight side portion (23) is close to the straight side portion (23). The method for manufacturing a blade according to claim 1 or 3, wherein the blade is alternately formed in a zigzag shape at a position away from the straight side portion (23). The blade is configured in a cylindrical bowl shape with a blade support (21) having a circular blade receiving portion (31) and a blade body (20) circumscribing the circular peripheral surface of the blade receiving portion (31). ,
The radius (R1) of the inner surface of the second blank (38) whose section is formed in a partial arc shape is set slightly smaller than the radius (R2) of the circular peripheral surface of the blade receiving portion (31),
In the step of welding the second blank (38) to the blade support (21), the second blank (38) is elastically deformed with a jig so that the inner surface of the second blank (38) is the blade receiving portion (31). The method for manufacturing a blade according to claim 1, 2, 3, 4, or 5, wherein the blade is held in close contact with the circular peripheral surface, and the second blank (38) is welded while maintaining the held state.   A blade obtained by the manufacturing method according to any one of claims 1 to 6.   A small electric device for cutting the object to be cut by rotationally driving the blade according to claim 7 with a motor (12, 70).

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