JP2006272425A - Flanged shaft member and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a flanged shaft member of a simple structure, having wear resistance and high toughness. <P>SOLUTION: In the flanged shaft member in which a flange member is fitted to a shaft member, the fitting part on both sides or either one side of the flange member is irradiated with a laser beam obliquely in the range of 30-70° and welded around the circumference. Duration of the laser irradiation is 1-5 seconds, and the laser irradiation is performed continuously. After the welding, tempering is performed for 1-2 hours at 180-220°C for the purpose of releasing inner distortion of the weld zone. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a flanged shaft member in which a flange member is joined by laser welding, and a method for manufacturing the same.

  Laser welding has features such as fast welding time, precision welding such as fine welding, low thermal distortion, and dissimilar metal welding. Laser welded parts are used for the parts. As one of the components, there is a component in which a flange member is integrated with a shaft member that requires wear resistance by laser welding to be used as a flanged shaft member. As one technique showing the welded structure of the brazed shaft member, the technique disclosed in Patent Document 1 below can be seen.

Japanese Patent Laid-Open No. 11-245065

  The conventional welding structure shown in Patent Document 1 will be described with reference to FIGS. FIG. 3 is a perspective view of the weld lap joint shown in Patent Document 1, and FIG. 4 is a cross-sectional view of the main part thereof. 3 and 4, the weld lap joint 8 is composed of a flange portion 2 having a flange portion 11 and a neck portion 12 and a pipe-like shaft portion 3 having a through hole. Part 3 is press-fitted. And the structure which welded the flange part 2 and the axial part 3 in the fusion | melting part 1 laser-welded by irradiating the laser 7 in the part of the neck part 12 is taken. Further, the dilution rate in the melted part 1 (expressed by the melted part area of the shaft part 3 / the total melted part area of the shaft part 3 and the flange part 3 in the same cross section) is 15 to 45%. Is preferred.

  In the weld lap joint 8 having the above laser welding structure, the weld lap joint 8 is configured to have a shape in which a neck 12 for laser welding is provided on the flange 2. That is, the neck 12 is provided for performing laser welding. The flange 2 provided with the neck portion 12 cannot be formed by a pressing method or the like, and is formed by cutting out from a thick pipe material or a round bar. Therefore, the processing method of part manufacture is restricted, and the part manufacture cost is increased. Further, when the outer diameter of the collar portion 11 is increased, the amount of material to be discarded by cutting increases, and the material cost is increased and the material cost is wasted.

  Furthermore, when using it in a narrow space, this welded structure cannot be used at all if there is not enough space and a structure with a neck portion cannot be obtained. Therefore, there is a demand for a laser welding structure capable of strong welding joining with only the shape of the collar without a neck.

  The present invention has been made in view of the above problems, and the object of the present invention is to obtain a laser welding structure capable of obtaining a strong joint strength between a flange member and a shaft member in a simple shape, and very inexpensive. It is to be able to manufacture a flanged shaft member at a cost.

  As a means for solving the above-mentioned problems, the flanged shaft member of the present invention is a flanged shaft member in which the flange member is fitted to the shaft member. It is characterized in that the fitting part on one side is irradiated with laser from an oblique direction and welded over one round. Further, the laser irradiation angle from the oblique direction here is 30 ° to 70 ° with respect to the flange surface of the flange member, and the laser irradiation time is continuous irradiation of 1 to 5 seconds.

  Further, the outer diameter of the shaft member is limited to a range of 1.0 to 5.0 mm, and the depth of the welded portion is preferably set to a range of 0.4 to 0.8 mm. And the welding part of a shaft member and a gutter member is a tempered martensite structure, It is characterized by the above-mentioned. Further, the shaft member is made of high carbon steel, and the collar member is made of high carbon steel or SUS material.

Further, the manufacturing method of the present invention for obtaining the configuration of the above-described flanged shaft member is a method for manufacturing a flanged shaft member in which the flange member is fitted to the shaft member. A process of irradiating a laser by continuously irradiating a laser beam from one side of the fitting part on either side, or one side of the fitting part, and a tempering process to release the internal distortion of the weld part;
It is characterized by having. Further, the laser irradiation angle from the oblique direction here is 30 ° to 70 ° with respect to the flange surface of the flange member, and the laser irradiation time is 1 to 5 seconds. And the outer diameter of a shaft member is restrict | limited to the range of (phi) 1.0-5.0mm, and the depth of a welding part makes the range of 0.4-0.8mm suitable. Further, the tempering of the welded portion is performed at a temperature of 180 ° to 220 ° C for 1 to 2 hours.

  As an effect of the invention, in the present invention, a laser irradiation is performed from an angle range of 30 ° to 70 ° obliquely on the fitting portion on both sides of the flange member or the fitting portion on either one side. As a result, welding is performed by irradiating both the shaft member and the eave member with the laser beam to melt both members, and the required welding strength is obtained. When the angle is less than 30 °, the melted portion of the eaves member becomes shallow, and the welded portion with the shaft member is reduced, so that the welding strength cannot be obtained. Further, if the angle is smaller than 30 °, the melting depth to the shaft member becomes deep, and in the case of a shaft member having a small outer diameter, the laser beam is irradiated over the entire circumference and the melted portion is connected. The portion becomes weak in strength and is easily damaged and deformed. Conversely, when the irradiation angle is larger than 70 °, the radial melted portion of the shaft member becomes shallower, the melted portion in the heel member direction becomes wider, and the melted portion with respect to the full width of the heel member becomes wider during processing. As a result, the fixing force is reduced, causing positional displacement and deformation of the eaves member. The laser irradiation time is in the range of 1 to 5 seconds. If the laser irradiation time is shorter than 1 second, the melting depth becomes shallow, resulting in insufficient welding strength. On the contrary, if it is longer than 5 sec, the melting depth becomes deep, and in the shaft member having a small outer diameter, the melted portion is connected over the entire circumference, and the portion becomes weak in strength and easily broken. The laser irradiation time is preferably set to an optimum time according to the outer diameter of the shaft member.

  In the present invention, the outer diameter of the shaft member is limited to a range of φ1.0 to 5.0 mm. If it is made thinner than φ1.0 mm, the melted part is connected and the part becomes weak in strength. On the other hand, if it is thicker than φ5.0 mm, too much heat is dissipated, making it difficult to weld over one round. A uniform welding strength over one round is required, and when a portion with insufficient welding strength due to insufficient welding partially occurs, breakage such as a crack occurs from that portion. Further, when the outer diameter of the shaft member is in the range of φ1.0 to 5.0 mm and the depth of the welded portion is in the range of 0.4 to 0.8 mm, the bonding strength is increased and satisfactory welding is achieved. can get.

  Further, the shaft member and the flange member in the present invention use carbon steel or high carbon steel material because of the necessity of strength resistance and wear resistance. Then, in an inert gas atmosphere, a shaft member is formed by continuously irradiating a laser beam on a fitting portion on both sides of the flange member or one of the fitting portions on one side of the flange member by irradiating the laser continuously from an oblique direction. And the heel member are joined. The part melted by the laser irradiation is transformed into a martensitic structure having a needle-like structure by performing high-temperature quenching and cooling in a short time. However, since this martensite structure has large internal stress and low toughness, it is tempered at 180 ° to 220 ° C. for 1 to 2 hours to remove internal stress and enhance toughness. As a result, the melted portion, that is, the welded portion has a tempered martensite structure, and a brazed shaft member having high hardness, high toughness, and high wear resistance is obtained. Further, since the laser irradiation is performed by continuous irradiation by continuous oscillation, it is possible to obtain a welding finish with less generation of cracks and blowholes. Further, the metal oxidation of the welded portion is prevented by irradiating laser in an atmosphere using an inert gas such as argon gas, helium gas or nitrogen gas, or while blowing these inert gas.

  By taking the above manufacturing method and welding the shaft member and the flange member to form the flanged shaft member, even a high carbon steel with a high carbon content can be bonded without stress strain. It becomes possible. Further, since the eaves member is made of a flat plate, it can be easily manufactured by a press working method or the like. Parts cost can be made very cheap.

  The best mode for carrying out the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view schematically showing a main part of a brazed shaft member according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the main part of the brazed shaft member shown in FIG. It is shown. First, in FIG. 1, the flanged shaft member 20 includes a shaft member 21 and a flange member 22, and the shaft member 21 and the flange member 22 are fitted by a method such as press fitting. The structure is such that the shaft member 21 and the flange member 22 are integrated by laser welding of the part and laser welding. The shaft member 21 here is formed in a shape like a round bar and used as a sliding shaft. The eaves member 22 has a hole 22a for fitting with the shaft member 21 and has a flat ring shape. Further, since the shaft member 21 and the flange member 22 are required to have wear resistance, toughness, corrosion resistance, etc., the carbon content capable of quenching alloy tool steel, high-speed tool steel, martensitic stainless steel, etc. Material with a lot of is used. A indicates laser light. The laser beam A is irradiated by a corner portion in which the shaft member 21 is fitted into the hole 22a of the flange member 22 by a method such as press-fitting, that is, the flange surface 22b on one side of the flange member 22 and the shaft member 21 intersect. A method of irradiating the portion O over the entire circumference from the angle θ is taken.

  As the laser, a YAG (yttrium, aluminum, garnet) laser is used. The YAG laser light from the laser oscillator is guided to the emission unit 25 through the optical fiber 26, and the laser light A is emitted from the emission unit 25 from the position of the angle θ shown in FIG. At this time, the focal point of the laser beam A is set to be a position of a fitting portion (corner portion) O where the flange surface 22b of the flange member 22 and the shaft member 21 intersect.

  Laser welding is performed in an atmosphere of an inert gas such as argon gas, helium gas, or nitrogen gas, or by blowing these inert gases. In this embodiment, since it is performed while rotating the welding work (brazed shaft member), the inert gas is blown under atmospheric pressure in consideration of work efficiency. An inert gas is used for the purpose of preventing oxidation at the welding site.

  Laser oscillation is performed continuously. That is, the laser beam A is continuously output and continuously irradiated. The welding by this continuous irradiation suppresses the generation of cracks and blowholes, and a uniform welding can be obtained over one round. Also, a small output amount is sufficient.

  Laser welding of the brazed shaft member 20 is performed while rotating the brazed shaft member 20. The position is fixed so that the welding position of the brazed shaft member 20 does not move, and the brazed shaft member 20 is rotated using an apparatus in which the brazed shaft member 20 rotates at a constant speed.

  The welding strength (referred to as welding strength; hereinafter, welding will be described as welding) is strongly influenced by the irradiation angle θ of the laser beam A. For example, when the irradiation angle θ is a small angle, the shaft member 21 melts at a deep depth, but the melting portion of the flange member 22 is very small. And the welding part of the eaves member 22 and the shaft member 21 decreases, and welding strength will become very weak. Further, when the irradiation angle θ is decreased, the melting width of the flange member 22 is widened, and it is difficult to dissipate heat from the flange member 22, which causes deformation of the flange member 22, or the fixing force of the flange member 22 is decreased, thereby causing a positional shift. To wake you up. Although this irradiation angle (theta) points out the angle on the basis of the collar surface 22b of the collar member 22, in this invention, the range of 30 degrees-70 degrees is set to this irradiation angle as a suitable range. Deviating from this angle causes the problem of insufficient welding strength as described above. Further, as a result of the experiment, it was found that 45 ° to 50 ° is a more preferable range.

  Next, in the present invention, the outer diameter d of the shaft member 21 is limited to φ1.0 to 5.0 mm, and the welding depth t is limited to 0.4 to 0.8 mm. In FIG. 2, C indicates a welded portion. When the welded portion C is irradiated with the laser beam A from the irradiation angle θ over one round, the melted portion 21 c of the shaft member 21 and the melted portion 22 c of the flange member 22 are Appears, and the melted portion 21c and the melted portion 22c are joined together to form a welded portion C. And this welding part C is formed over a round. The depth t of the welded portion C affects the welding strength. If it is too shallow, the welding strength will be insufficient, and if it is too deep, the melted part 21 c will be connected to the shaft member 21. When the melted parts are connected, the connected parts become brittle and breakage or bending occurs. In the present invention, when the outer diameter d of the shaft member 21 is φ1.0 to 5.0 mm, the welding depth t is preferably in the range of 0.4 to 0.8 mm in order to obtain the required adhesion strength. It has become.

  The depth of welding is determined by the output of the laser beam and the irradiation time. When the output is increased, the melting depth can be increased, and when the irradiation time is lengthened, the melting depth can be increased. However, the irradiation time and output also affect the generation of cracks and blowholes. Therefore, it is necessary to set a suitable range for the irradiation time and output. In the present invention, the irradiation time for obtaining the range where the outer diameter d of the shaft member 21 is φ1.0 to 5.0 mm and the welding depth t is 0.4 to 0.8 mm is 1.0 to 5. It is good to carry out in the range of 0 sec. The output is preferably performed in the range of 200 to 300W. Within this range, the irradiation time and the output amount are appropriately set in view of the welding strength and the occurrence of cracks and blowholes.

  Next, the manufacturing method of the flanged shaft member 20 of the present invention will be described. In this embodiment, laser irradiation is performed while blowing nitrogen gas in the atmosphere. First, as preparation before performing laser irradiation, the laser beam A is irradiated to the position of the fitting part O of the hooked shaft member 20 on the rotating shaft member 20 to which the shaft member 21 and the hook member 22 are fitted. Fix to the position where you want to. Further, the laser beam A emitting unit 25 is preliminarily positioned at a position where an irradiation angle of θ set in advance within an angle range of 30 ° to 70 ° is obtained, and at a position where the focal point of the laser beam A is at the O position. Keep it fixed. Then, while the brazed shaft member 20 is rotated, the laser beam A is irradiated to the position of O over one round to perform welding. The irradiation time is a preset time within a range of 1.0 to 5.0 sec. The output is performed with a preset output in the range of 200 to 300 W.

  After the laser irradiation is finished, the brazed shaft member 20 is placed in a firing furnace and left to stand at 180 ° to 220 ° C. for 1 to 2 hours for tempering. This is because rapid heating and rapid cooling are performed by laser irradiation for a short time, so the welded part becomes a martensitic structure with a needle-like structure, has internal stress, and is brittle. Yes. When tempering is performed at 180 ° to 220 ° C. for 1 to 2 hours in order to remove the internal stress and at the same time toughness, the welded portion is transformed into a tempered martensite structure having no needle-like structure. Further, a weld having high hardness, good wear resistance, and high toughness can be obtained.

  In this embodiment, the shaft member 21 and the flange member 22 are welded on the flange surface 22b side of the flange member 22, but may be welded on the flange surface 22e side opposite to the flange surface 22b. Further, welding may be performed on both sides of the flange surfaces 22b and 22e. When welding is performed on both sides, an even higher welding strength can be obtained, and the bonding strength becomes very strong. Note that when welding is performed on both sides, a gutter member having a thickness sufficient to prevent the melted portion of the gutter member 22 from being connected is used. It is preferable to select both-side welding and one-side welding in consideration of the thickness and welding strength of the flange member 22.

  The method of welding the shaft member 21 and the flange member 22 by laser has been described above. However, when wear resistance and toughness are required for the entire individual members of the shaft member 21 and the flange member 22, the individual members ( The shaft member 21 and the eaves member 22) are subjected to heat treatment in advance to increase the hardness, and the members are used in a state where the internal stress is removed. This heat treatment is performed by quenching the member at a temperature of 800 ° to 850 ° C., and performing a tempering treatment at a temperature of 180 ° to 200 ° C. for 1 to 2 hours, thereby having high hardness and high wear resistance and toughness. Some characteristics are obtained. And the flanged shaft member 20 welded by said manufacturing method using the shaft member 21 and the flange member 22 which were heat-treated in this way is formed.

  In the present embodiment, the shaft member 21 is shown in a round bar shape used as a float or a plunger. However, both ends of a shaft used as a cam or a gear shaft may have a narrow shaft shape. . Furthermore, a cylindrical shape may be used if the melting depth is taken into consideration.

  By adopting the above manufacturing method, it is possible to obtain a brazed shaft member having high welding strength and wear resistance and toughness. Further, it can be used as a brazed shaft member by laser welding using high carbon steel having a high carbon content. Since the shaft member is used as a sliding shaft, it requires wear resistance and toughness. However, since the eaves member does not necessarily have the same characteristics as the shaft member, the carbon content is low in that case. There is no problem even if the saddle member is formed using low carbon steel. Further, since the eaves member has a flat plate shape, it can be easily formed by a press working method. Further, since the mass production is possible, the manufacturing cost can be very low. Moreover, it becomes possible to fully utilize in a narrow space. Moreover, when the eaves member has a flat plate shape, various shapes can be formed by a pressing method. For example, it is possible to easily form an outer shape having a square or hexagonal shape, a shape in which a through hole is provided on the flange surface, or a shape having irregularities on the flange surface.

As Example 1 of this invention, the shaft member and the collar member formed the shaft member with a collar using the thing of the following specification.
Shaft member ··· Material: SK4, Dimensions: External diameter φ1.6mm, length 34mm, blank production by cutting, hardness Hv750 by heat treatment (quenching, tempering), barrel polishing and plating, shaft member Forming.
鍔 Material: ・ ・ ・ Material: SK4, Dimensions: φ3.2mm, Thickness 0.7mm, Blank production by press working, hardness Hv750 by heat treatment (quenching, tempering), barrel polishing and plating Form members.
The shaft member and the flange member are fitted by a press-fitting method, and laser irradiation is performed only on one side. Laser irradiation was performed at an irradiation angle of 45 °, an output of 260 W, and an irradiation time of 2.5 seconds, followed by tempering at 200 ° C. for 2 hours. As a result, the depth of welding was 0.65 mm, and the required welding strength was obtained. Moreover, the generation | occurrence | production of a crack and a blowhole was not seen, and evaluation was the determination of OK.

  In Example 1, high carbon steel of SK4 is used for the eaves member, but materials such as SUS may be used. When the SUS material is used, oxidation of the welded portion can be prevented, and re-plating for rust prevention is not necessary in the subsequent process.

  In Example 2, the laser irradiation conditions were changed using a shaft member and a flange member having the same specifications as those in Example 1. Irradiation was performed at an irradiation angle of 45 ° and an output of 220 W for 4.5 sec, and then tempering was performed at 200 ° C. for 2 hours. As a result, the depth of welding was 0.60 mm, and the required welding strength was obtained. Moreover, the generation | occurrence | production of a crack and a blowhole was not seen, and evaluation was the determination of OK.

It is the principal part perspective view which drawn typically the state which is irradiating the laser with the brazed shaft member which concerns on embodiment of this invention. It is principal part sectional drawing of the flanged shaft member shown in FIG. It is a perspective view of the weld lap joint shown in patent documents 1 as conventional technology. It is principal part sectional drawing of the weld lap joint shown by FIG.

Explanation of symbols

20 Shafted shaft member 21 Shaft member 22 Scissor member 22a Hole 22b, 22e Saddle surface 25 Output unit 26 Optical fiber A Laser light C Welding portion θ Irradiation angle t Depth d Outer diameter

Claims (11)

In a flanged shaft member in which a collar member is fitted to the shaft member, the fitting part on both sides of the collar member or the fitting part on either one side of the collar member is irradiated with laser from an oblique direction over the entire circumference. A flanged shaft member that is welded. The flanged shaft member according to claim 1, wherein a laser irradiation angle from the oblique direction is 30 ° to 70 ° with respect to the flange surface of the flange member. The brazed shaft member according to claim 1 or 2, wherein the laser irradiation time from the oblique direction is continuous irradiation of 1 to 5 seconds. The outer diameter of the said shaft member is (phi) 1.0-5.0mm, The depth of the welding part is 0.4-0.8mm, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. Brazed shaft member. The brazed shaft member according to any one of claims 1 to 4, wherein a welded portion of the shaft member and the flange member has a tempered martensite structure. The brazed shaft member according to any one of claims 1 to 5, wherein a material of the shaft member is high carbon steel, and a material of the flange member is high carbon steel or SUS material. In the manufacturing method of the flanged shaft member formed by fitting the flange member to the shaft member,
In an inert gas atmosphere, the step of welding by irradiating a laser continuously from one side of the fitting portion on both sides of the flange member, or one of the fitting portions on one side, from an oblique direction;
A tempering step for releasing internal distortion of the welded portion;
The manufacturing method of the shaft member with a flange characterized by having. The method of manufacturing a flanged shaft member according to claim 7, wherein a laser irradiation angle from an oblique direction is 30 ° to 70 ° with respect to the flange surface of the flange member. The method for manufacturing a brazed shaft member according to claim 7 or 8, wherein the continuous laser irradiation time from the oblique direction is 1 to 5 seconds. The outer diameter of the said shaft member is (phi) 1.0-5.0mm, The depth of the welding part is 0.4-0.8mm, The any one of Claim 7 thru | or 9 characterized by the above-mentioned. A method for manufacturing a flanged shaft member. The method for manufacturing a brazed shaft member according to any one of claims 7 to 10, wherein the tempering of the welded portion is performed at a temperature of 180 ° to 220 ° for 1 to 2 hours.

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