JP2007170622A - Joint structure of torque transmission member, joining method for torque transmission member, and power transmission device using them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems wherein a locking member is required when forming recessed parts in a pinion shaft and a differential case to prevent the pinion shaft from falling out in a differential device, thereby increasing cost, and to join torque transmission members difficult in joining conventionally to fix the members mutually. <P>SOLUTION: The first torque transmission member 3 made of an iron material and the second torque transmission member 5 of cast aluminum alloy are mutually joined through the other member 7 being an aluminum-based welding material having close affinity to each of them by welding. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a torque transmission member joining structure, a torque transmission member joining method, and a power transmission device using these.

Patent Document 1 describes a differential device 1001 as shown in FIG. The differential device 1001 includes a differential case 1003, a bevel gear type differential mechanism 1005 assembled to the differential case 1003, a ring gear 1009 fixed to the differential case 1003 with a bolt 1007, and the like, and a pinion shaft 1011 of the differential mechanism 1005. The recesses 1013 and 1015 are respectively formed in the differential case 1003, and the ring gear 1009 is held at the inner periphery of the locking member 1017 attached to the recesses 1013 and 1015 to prevent the pinion shaft 1011 from falling off.
JP-A-7-167253

  However, in the differential device 1001, in order to prevent the pinion shaft 1011 from falling off, the locking member 1017 is required to process the recesses 1013 and 1015 in the pinion shaft 1011 and the differential case 1003, which increases the cost. Yes.

  Further, since the bolt 1007 is used to fix the ring gear 1009, the number of parts including the bolt 1007 increases accordingly, and the axial dimension at the bolt fixing portion is increased.

  In general, in order to fix (connect) the members to each other, there are methods such as welding and spline connection in addition to the method using bolts.

  However, in the case of welding, there is a problem that there are materials that are difficult to weld, such as cast irons, and it is difficult to weld different materials.

  In addition, in order to give the spline part the necessary strength, the spline part is made entirely of a high-grade material such as carburized steel, or in the case of a cast iron member, the spline part is subjected to induction hardening, for example. However, the cost is increased, and the former tends to be excessive in quality other than the spline portion.

  In addition, for welding different types of materials, for example, a magnetic material constituting a magnetic path (for example, an iron-based alloy such as low carbon steel) and a non-magnetic material such as an aluminum alloy that reduces magnetic flux leakage from the magnetic path are used. Although it may be desired to weld, as is well known, since these welding is difficult, conventionally, a method of screwing them is used. In this case, in addition to threading each member, means for preventing loosening Is required, the number of parts is large, and the cost is high.

  Also, dissimilar materials such as cast iron members and steel members are welded by beam welding, but beam welding is expensive, and the amount of thermal deformation applied to the member is large, and the materials (base materials) that can be welded are limited. Is done.

  Therefore, an object of the present invention is to provide a torque transmission member joining structure, a torque transmission member joining method, and a power transmission device using them.

  The torque transmission member joining structure according to claim 1 is characterized in that the first torque transmission member and the second torque transmission member are joined via other members having close affinity to each other. And

  The invention according to claim 2 is the torque transmission member joining structure according to claim 1, wherein the first torque transmission member and the second torque transmission member are positioned in a radial direction by the joining. It is characterized by being.

  A third aspect of the present invention is the torque transmission member joining structure according to the first aspect, wherein the first torque transmission member and the second torque transmission member are axially positioned by the joining. It is characterized by being.

  The invention of claim 4 is the torque transmission member joining structure according to any one of claims 1 to 3, wherein at least one of the first torque transmission member and the second torque transmission member is: A surface treatment is performed prior to the joining.

  A fifth aspect of the present invention is the torque transmission member joining structure according to any one of the first to third aspects, wherein one of the first torque transmission member and the second torque transmission member is made of aluminum. It is a new alloy, the other is an iron-based alloy, and the iron-based alloy is galvanized prior to the joining.

  The invention of claim 6 is the torque transmission member joining structure according to any one of claims 1 to 5, wherein one or both of the first torque transmission member and the second torque transmission member are: It is characterized by being carburized steel, tempered steel or cast iron.

  The torque transmission member joining method according to claim 7 is characterized in that the first torque transmission member and the second torque transmission member are joined via other members having close affinity with each other. .

  The invention according to claim 8 is the method for joining torque transmitting members according to claim 7, wherein the first torque transmitting member and the second torque transmitting member are positioned in the radial direction by the joining. It is characterized by.

  The invention according to claim 9 is the method for joining torque transmitting members according to claim 7, wherein the first torque transmitting member and the second torque transmitting member are positioned in the axial direction by the joining. It is characterized by.

  The invention of claim 10 is the method for joining torque transmission members according to any one of claims 7 to 9, wherein at least one of the first torque transmission member and the second torque transmission member is A surface treatment is performed prior to the joining.

  The invention of claim 11 is the method for joining torque transmission members according to any one of claims 7 to 10, wherein one of the first torque transmission member and the second torque transmission member is aluminum. It is a new alloy, and the other is an iron-based alloy, and the iron-based alloy is galvanized prior to the joining.

  A twelfth aspect of the present invention is the torque transmission member joining method according to any one of the seventh to eleventh aspects, wherein one or both of the first torque transmission member and the second torque transmission member are provided. It is characterized by using carburized steel, tempered steel or cast iron.

  A power transmission device according to claim 13 is a power transmission device having a first torque transmission member and a second torque transmission member in a torque transmission path, wherein the first torque transmission member and the second torque transmission member are provided. These torque transmission members have the joint structure according to any one of the first to sixth aspects, or are joined by the method according to the seventh to twelfth aspects.

  The power transmission device according to claim 14 is a power transmission device having a torque transmission member and a meshing member on one side of the meshing portion in a torque transmission path, wherein the torque transmission member and the meshing member are It has the joining structure of Claims 1-6, or is joined by the method of the said Claims 7-12.

  According to the joining structure of the torque transmission member of the first aspect, the first torque transmission member and the second torque transmission member are joined via the other members having close affinity to each other.

  Conventionally, it is possible to join similar materials (for example, cast iron members) or dissimilar materials (for example, magnetic materials and non-magnetic materials, cast iron members and steel members), which are difficult to weld. There is no need to use complicated or high-cost joining such as landing welding or beam welding.

  The joint structure of the torque transmission member according to claim 2 eliminates the need for the radial positioning member for each of the first and second torque transmission members and the number of mounting steps thereof, and the cost is reduced accordingly.

  The torque transmission member joining structure according to claim 3 eliminates the need for the axial positioning member for each of the first and second torque transmission members and the number of mounting steps thereof, thereby reducing the cost accordingly.

  According to a fourth aspect of the present invention, in the structure of the torque transmission member, at least one of the first and second torque transmission members is subjected to a surface treatment prior to the bonding. It becomes possible to add and surface-treat only to a necessary part, and it is possible to suppress the troublesomeness of adjusting the joining conditions of the member surfaces with respect to joining.

  The joint structure of the torque transmission member according to claim 5 is a case where one of the torque transmission members is an aluminum alloy and the other is an iron-based alloy. If an aluminum-based welding wire (welding material) is used, the iron-based alloy is The aluminum alloy is welded and firmly joined by brazing.

  The torque transmission member joining structure according to claim 6 can select a torque transmission member of carburized steel, tempered steel, or cast iron as the joining member.

  According to the method for joining torque transmitting members of claim 7, the same effect as that of the invention of claim 1 can be obtained.

  According to the method for joining torque transmitting members of claim 8, the same effect as that of the invention of claim 2 can be obtained.

  According to the method for joining torque transmitting members of claim 9, the same effect as that of the invention of claim 3 can be obtained.

  According to the method for joining torque transmitting members of the tenth aspect, the same effect as that of the fourth aspect of the invention can be obtained. Moreover, a surface treatment process can be performed before a joining process.

  According to the method for joining torque transmitting members of claim 11, the same effect as that of the invention of claim 5 can be obtained.

  According to the torque transmission member joining method of the twelfth aspect, an effect equivalent to that of the sixth aspect of the invention can be obtained.

  In the power transmission device according to a thirteenth aspect, the first and second torque transmission members have the joint structure according to the first to sixth aspects, or are joined by the method according to the seventh to twelfth aspects. Thus, the same effects as those of these configurations can be obtained.

  In the power transmission device of claim 14, the torque transmission member and the meshing member have the joint structure of claim 1 to claim 6 or are joined by the method of claim 7 to claim 12. The same effect as these configurations can be obtained.

<First Embodiment>
A power transmission device 1 according to the first embodiment, a torque transmission member joining structure used in the power transmission device 1, and a torque transmission member joining method will be described with reference to FIG. The power transmission device 1 is disposed in the rear wheel side power system of the four-wheel drive vehicle, and the right side of FIG. 1 corresponds to the front of the vehicle.

[Features of Joint Structure of Torque Transmission Member of First Embodiment]
The joint structure of the torque transmission member is such that the rotor 3 (first torque transmission member: magnetic material: low carbon steel) and the cylindrical member 5 (second torque transmission member: nonmagnetic material: aluminum alloy) are tightly connected to each other. Are joined via welding wires 7 (other members) having a good affinity, the rotor 3 and the cylindrical member 5 are positioned in the axial direction by the joining, and the rotor 3 is an iron-based alloy, Prior to the joining, galvanization (surface treatment) is performed.

  Reference numeral 8 denotes a centering portion between the cover 27 and the cylindrical member 5, and reference numeral 10 denotes a centering portion between the rotor 3 and the cylindrical member 5. Each centering portion is positioned in the radial direction with a gap of about an intermediate fit.

[Features of Joining Method of Torque Transmission Member of First Embodiment]
In this torque transmission member joining method, the rotor 3 and the cylindrical member 5 are joined to each other via welding wires 7 (other members) having close affinity, and the rotor 3 and the cylindrical member 5 are joined by the above joining. Positioning in the axial direction, the rotor 3 that is an iron-based alloy is galvanized (surface treatment) prior to the joining.

[Features of power transmission device 1]
The power transmission device 1 includes a rotor 3 and a cylindrical member 5 in a torque transmission path, and the rotor 3 and the cylindrical member 5 have the joint structure according to claim 1, 3, 4, and 5. Are joined by the method according to claim 7, 9, 10, 11.

[Configuration of Power Transmission Device 1]
The power transmission device 1 is housed in a differential carrier, and includes a housing 9, a hub 11 that is relatively rotatable inside thereof, a multi-plate main clutch 13 and a pilot clutch 15, an electromagnetic magnet 17, a cam ring 19, and the like. The ball cam 21, the pressure plate 23, the armature 25, and a controller are included.

  The housing 9 includes the rotor 3 and the cylindrical member 5 described above and a cover 27 made of an iron-based alloy. The welding wire 7 is an aluminum-based welding material, and the rotor 3 uses the welding wire 7 at the rear side opening (welding portion A) of the cylindrical member 5 to connect the aluminum-based cylindrical member 5 to an iron-based rotor. It is welded from a welding direction 71 (radially outer side) as a direction in which the surface height is made higher than 3 and melted first. The rotor 3 is forged from low carbon steel, brazed by a welding wire 7, and the cylindrical member 5 is cast from an aluminum alloy and welded to the welding wire 7. The cover 27 is also forged from an iron-based alloy, has a close affinity for the welding wire 7, and is made of an aluminum-based cylindrical member at the front side opening (welded portion B: butt weld) of the cylindrical member 5. 5 is welded with a welding wire 7 from a welding direction 73 (axial direction) as a direction in which the surface height is higher than that of the iron-based rotor 3 and is melted first. Further, the housing 9 has a transmission shaft portion 29 formed integrally with the cover 27 supported by a differential carrier by a ball bearing 31, and the propeller is connected to the transmission shaft portion 29 via a companion flange and a joint side flange. It is connected to the shaft and is driven to rotate by the driving force of the engine.

  The front end of the hub 11 is supported on the housing 9 (cover 27) by a ball bearing 33, and the rear end is supported on the housing 9 (rotor 3) by a needle bearing 35. Further, an X ring 37 that is a seal having an X-shaped cross section is disposed between the rear end of the hub 11 and the rotor 3. A drive pinion shaft is splined to the inner periphery of the hub 11, and a rear end of the drive pinion shaft constitutes a part of a direction changing gear set disposed in front of a differential device (rear differential) on the rear wheel side. A bevel gear is formed.

  The space formed between the housing 9 and the hub 11 is sealed by the welded portion A, the welded portion B, and the X-ring 37 to prevent oil leakage and entry of foreign matter. Oil is injected into the sealed space through an oil hole 39 provided in the cover 27. After the oil is injected, the oil hole 39 is press-fitted with a ball plug 41 and sealed. The hub 11 is provided with a through hole 45 that receives centrifugal force to move the oil in the oil space 43 toward the main clutch 13.

  The main clutch 13 is provided between the housing 9 (cylindrical member 5) and the hub 11, and the pilot clutch 15 is provided between the cylindrical member 5 and the cam ring 19. The ball cam 21 is provided between the cam ring 19 and the pressure plate 23, and a bearing 47 that receives the cam reaction force of the ball cam 21 is disposed between the cam ring 19 and the rotor 3. The pressure plate 23 is splined to the outer periphery of the hub 11, and the armature 25 is splined to the inner periphery of the cylindrical member 5 between the pilot clutch 15 and the pressure plate 23. The welded portion A and the welded portion B are provided with a joining strength sufficient to receive the cam thrust generated by the ball cam 2.

  The core 49 of the electromagnetic magnet 17 penetrates into the concave portion of the rotor 3 through a predetermined air gap, is supported on the rotor 3 by a double-side sealed ball bearing 51, and is connected to the differential carrier by a detent member. The lead wire drawn out from the core 49 is guided in a desired direction via a rotation preventing member, drawn out to the outside of the differential carrier via a connector or the like, and connected to the battery.

  The core 49, the rotor 3, the pilot clutch 15 and the armature 25 constitute a magnetic path of the electromagnetic magnet 17. The rotor 3 is divided into a radially outer rotor base 55 and a radially inner rotor base 57 by a ring 53 of a non-magnetic material (for example, aluminum alloy or austenitic stainless steel). The plate is provided with notches provided at equal intervals in the circumferential direction at radial positions corresponding to the ring 53 and bridge portions that connect the notches. These rings 53 and notches prevent magnetic flux from being short-circuited on the magnetic path.

  The controller performs excitation of the electromagnetic magnet 17, control of excitation current, excitation stop, and the like. When the electromagnetic magnet 17 is excited, a magnetic flux loop 59 is formed in the above magnetic path, and the pilot clutch 15 is pressed and fastened by the attracted armature 25, and pressure is exerted by the cam thrust force of the ball cam 21 that operates by receiving torque. The main clutch 13 is pressed and fastened via the plate 23, and the vehicle is in a four-wheel drive state. When the excitation of the electromagnetic magnet 17 is stopped, the connection of the main clutch 13 is released and the vehicle is in a two-wheel drive state.

[Assembly of power transmission device 1]
The assembly of the power transmission device 1 is performed as follows.

  (1) The cover 27 and the cylindrical member 5 are welded at the welded portion B.

  (2) Built-in members such as the main clutch 13, the pilot clutch 15, the cam ring 19, the ball cam 21, the pressure plate 23, and the armature 25 are incorporated into the cylindrical member 5.

  (3) While adjusting the relative position of the rotor 3 and the cylindrical member 5 in the axial direction, the assembly gap of the built-in member is set, and the torque transmission characteristics of the power transmission device 1 are adjusted by passing a current through the electromagnetic magnet 17 in advance. Establish within the standard.

  (4) The rotor 3 and the cylindrical member 5 are fixed to the set position using a jig such as a clamp.

  (5) The rotor 3 and the cylindrical member 5 are welded at the welded part A.

  (6) Oil is injected from the oil hole 39 and sealed with the ball plug 41 as described above.

  The cover 27 and the cylindrical member 5 may be welded at the welded portion B after assembling the internal parts with the welded portion A between the rotor 3 and the cylindrical member 5 first.

  For welding the welded portion A and the welded portion B, for example, a welding method called CMT (Cold Metal Transfer) can be used.

  This is a welding method in which the welding wire is reciprocated with respect to the base material. First, the welding wire is moved in a direction in contact with the base material to generate an arc (hot process), and the welding wire is When the melt pool is touched, the arc disappears and the welding current decreases, and then when the welding wire is moved away from the base metal, the droplets are cut and the short circuit current remains low (cold process). ).

  CMT is a welding method that is performed by moving the welding wire along the welded portion while repeatedly moving the welding wire (for example, several tens of times per second). As described above, the hot process and arc in which welding is performed are performed. All general purpose preforms and welding wires can be used by intermittently generating a disappearing cold process and keeping the weld relatively cool.

  Therefore, it is possible to weld dissimilar base materials (for example, aluminum and steel), which was impossible in the past, and butt welding of thin plates (for example, welded portion B) without using a backing material for the molten pool. ) Is possible.

[Effect of power transmission device 1]
The power transmission device 1 has the following effects.

  The rotor 3 and the cylindrical member 7, which are different materials, have a close affinity to each other, so that the rotor 3 is firmly joined by brazing (CMT welding), and the cylindrical member 7 is welded and firmly joined. (CMT welding), it is no longer necessary to carry out the screw-joining that has been used to fix them, and therefore, the threading of the rotor 3 and the cylindrical member 7 and the use of means for preventing loosening (nuts) are used. In addition, problems associated with the screw joint such as arrangement of the sealing means, increase in the number of parts, and cost increase are avoided.

  Further, since the rotor 3 and the cylindrical member 5 are positioned in the axial direction by the welded portion A, and it is not necessary to use another positioning means, this axial positioning means and its mounting man-hours become unnecessary, and the cost increases. Can be avoided.

  In addition, the rotor 3 that has been galvanized prior to joining with the cylindrical member 7 (which can surface-treat a necessary portion of the torque transmission member) has improved oxidation resistance and joinability to the welding wire 7.

  Further, in the power transmission device 1, while the magnetic characteristics are improved by the rotor 3 having excellent magnetic characteristics, magnetic flux leakage from the magnetic path is reduced by the cylindrical member 5, and the transmission capacity and intermittent function of the driving force are improved. .

Second Embodiment
A power transmission device 101 according to the second embodiment, a torque transmission member joining structure used in the power transmission device 101, and a torque transmission member joining method will be described with reference to FIG. Hereinafter, the difference will be described while giving the same reference numerals to members having the same functions as those of the power transmission device 1 of the first embodiment.

  The cover 103 of the power transmission device 101 is integrally forged with an iron-based alloy together with the transmission shaft portion 29, and is made of an iron-based or stainless steel-based opening at the front side opening (welded portion C: butt weld) of the cylindrical member 5. Joining (CMT welding) is performed from the direction of arrow 105 (outside in the radial direction) using a welding wire 7 (other member) of a welding material.

[Effect of power transmission device 101]
The power transmission device 101 can obtain the same effect as the power transmission device 1.

<Third Embodiment>
A power transmission device 201 according to the third embodiment, a joining structure of torque transmission members used in the power transmission device 201, and a joining method of the torque transmission members will be described with reference to FIG. The power transmission device 201 is used in the above four-wheel drive vehicle in place of the power transmission devices 1 and 101, and the right side in FIG. 3 corresponds to the front of this vehicle.

[Features of Joining Structure of Torque Transmission Member of Third Embodiment]
In this torque transmission member joining structure, the first hub 203 (first torque transmission member: carburized steel) and the second hub 205 (second torque transmission member: nonmagnetic material: austenitic stainless steel) are welded portions D. And are joined (CMT welding) from the direction of arrow 231 (outside in the radial direction) via a welding wire 7 (other member) of a welding material of iron or stainless steel having close affinity with each other,
The first hub 203 and the second hub 205 are positioned in the axial direction by the joining,
The first hub 203 is surface-treated prior to the joining, and the first hub 203 is made of carburized steel that has been carburized as a surface treatment.

[Features of Joining Method of Torque Transmission Member of Third Embodiment]
The torque transmission member is joined by joining (CMT welding) the first hub 203 and the second hub 205 via welding wires 7 (other members) having close affinity with each other,
The first hub 203 and the second hub 205 are positioned in the axial direction by the above-described joining, and are positioned by the centering portion 12 in the radial direction, and carburized steel is used for the first hub 203.

[Features of power transmission device 201]
The power transmission device 201 includes a first hub 203 and a second hub 205 in a torque transmission path, and the first hub 203 and the second hub 205 are joined according to claims 1, 3, 4, and 6. It has a structure, or it is joined by the method of Claim 7, 9, 10, 12.

[Configuration of Power Transmission Device 201]
The power transmission device 201 is housed in a differential carrier, and includes a housing 207, a hub 209 disposed inside the housing 207 so as to be relatively rotatable, a main clutch 13, a pilot clutch 15, an electromagnetic magnet 17, a cam ring 19, and a ball cam. 21, a pressure plate 23, an armature 25, a controller, and the like.

  The housing 207 includes a rotor 211 forged by low carbon steel, a cylindrical member 213 cast by an aluminum alloy, and a connecting member 215 made of an iron-based alloy. The rotor 211 is screwed into the rear side opening of the cylindrical member 213 and is positioned by the double nut function of the nut 217 to prevent falling off. An O-ring 219 is disposed between the rotor 211 and the cylindrical member 213. Yes. After injecting oil from an oil hole 39 provided in the cylindrical member 213 and sealing it with the ball plug 41, the connecting member 215 is fixed to the front side opening of the cylindrical member 213 with a bolt 221. The housing 207 is connected to the propeller shaft via a companion flange and a joint-side flange that are spline-connected to the connecting member 215, and is rotationally driven by the driving force of the engine.

  The hub 209 is configured by joining the first hub 203 and the second hub 205 as described above. The first hub 203 is supported by the cylindrical member 213 by the ball bearing 33, and the second hub 205 is the sliding bearing 223. Is supported by the rotor 211. The main clutch 13 is disposed between the first hub 203 and the cylindrical member 213, and the drive pinion shaft on the rear differential side is splined to the inner periphery of the first hub 203. Further, X rings 225 and 37 are disposed between the first hub 203 and the cylindrical member 213 and between the second hub 205 and the rotor 211, and are formed between the housing 207 and the hub 209 together with the O ring 219. The sealed space is sealed to prevent oil leakage and entry of foreign matter.

  Further, since the second hub 205 close to the magnetic path of the electromagnetic magnet 17 is made of austenitic stainless steel made of a nonmagnetic material, magnetic flux leakage from the magnetic flux loop 59 is reduced.

[Effect of power transmission device 201]
The power transmission device 201 has the following effects.

  The first hub 203 and the second hub 205, which are dissimilar materials, are firmly joined by the welding wire 7 (CMT welding), and a sufficient driving force transmission function is obtained by the mechanical strength of the first hub 203, which is carburized steel. In addition, magnetic flux leakage from the magnetic path is reduced by the magnetic flux leakage prevention function of the second hub 205, which is a nonmagnetic material, and the driving force transmission capacity and the intermittent function of the power transmission device 201 (main clutch 13) are improved. .

  In addition, since the first hub 203 and the second hub 205 are positioned in the axial direction at the welded portion D, it is not necessary to use another positioning means, so that this positioning means and mounting man-hours are not required, and an increase in cost is avoided. It is done.

  Moreover, the 1st hub 203 can perform a surface treatment process as a carburizing process to a ferrous steel material before a joining process. Further, according to CMT welding, since heat input to the member is small at the time of joining the members, even carburized steel containing a large amount of carbon does not cause much heat input due to joining (welding) and does not cause cracking of the member. In this embodiment, the first and second hubs 203 and 205 as the joining members can be selected in accordance with the required strength and characteristics.

  In addition, the first hub 203 of the carburized steel does not change in structure even if it is not subjected to a carbonization treatment in the above-described joining process (no cracking due to welding heat occurs), and a desired property is obtained. The cost increase associated with is avoided.

<Fourth embodiment>
A power transmission device 301 according to the fourth embodiment, a torque transmission member joining structure used in the power transmission device 301, and a torque transmission member joining method will be described with reference to FIG. The power transmission device 301 is disposed in the rear wheel side power system of the four-wheel drive vehicle, and the upper part of FIG. 4 corresponds to the front of the vehicle.

[Features of Joining Structure of Torque Transmission Member of Fourth Embodiment]
The joint structure of the torque transmission member is such that the ring gear 303 (meshing member on one side of the meshing part: carburized steel) and the differential case 305 (torque transmission member: spheroidal graphite cast iron: FCD) are closely connected to each other at the welded part E. It is joined (CMT welding) from the welding direction 341 by a welding wire 7 (other member) of an iron or stainless steel welding material having affinity.
The ring gear 303 and the differential case 305 are positioned in the axial direction by the joint,
The ring gear 303 is surface-treated by carburizing prior to the joining, and the ring gear 303 is carburized steel.

[Features of Joining Method of Torque Transmission Member of Fourth Embodiment]
The method for joining the torque transmitting members is to join the ring gear 303 and the differential case 305 via the welding wires 7 having close affinity to each other,
The ring gear 303 and the differential case 305 are positioned in the axial direction by the above joint,
The ring gear 303 is carburized prior to the joining.

[Features of power transmission device 301]
The power transmission device 301 includes a ring gear 303 and a differential case 305 in the torque transmission path. Does the ring gear 303 and the differential case 305 have the joint structure according to claim 1, 3, 4, 6? Alternatively, they are joined by the method described in claims 7, 9, 10, and 12.

[Configuration of Power Transmission Device 301]
The power transmission device 301 is housed in a differential carrier 307 and is driven by a drive pinion shaft 309 driven by the driving force of the engine, a drive pinion gear 311 formed at the rear end of the drive pinion shaft 309, and the ring gear 303 described above. And a differential case 305 and a rear differential 315 including a bevel gear type differential mechanism 313.

  The drive pinion shaft 309 is supported on the differential carrier 307 by bearings 317 and 319 that receive a thrust force, and the drive pinion gear 311 meshes with the ring gear 303 to constitute a direction changing gear set. The differential case 305 is supported on the differential carrier 307 by bearings 321 and 321 receiving a thrust force.

  The differential mechanism 313 includes a pinion shaft 323, a pinion gear 325 supported on the pinion shaft 323, and left and right output side gears 327 and 329 supported by the differential case 305 and meshed with the pinion gears 325. , 329 are connected to left and right rear wheels via spline-connected drive shafts 331, 333. Further, the pinion shaft 323 is secured to the differential case 305 by a pin 335.

  The driving force of the engine that rotates the drive pinion shaft 309 is distributed from the direction change gear set to the left and right rear wheels via the rear differential 315.

[Effect of power transmission device 301]
The power transmission device 301 has the following effects.

  The ring gear 303 and the differential case 305 are firmly joined by the welding wire 7 (CMT welding), and thus it is possible to join a cast iron member (difference case 305: spheroidal graphite cast iron: FCD) that has been difficult to weld in the past. Therefore, there is no need to perform bolting or beam welding to join them.

  Therefore, problems such as the addition of bolt loosening prevention means and oil leakage prevention sealing means, an increase in the number of parts including bolts, and an increase in the axial dimension at the bolt fixing part, which occur when using bolted joints, are avoided. Is done.

  Further, since there is no need to beam weld a cast iron member and a steel member such as the differential case 305 and the ring gear 303, an increase in cost associated with beam welding and thermal deformation of the member are avoided.

  Further, the ring gear 303 and the differential case 305 can obtain a large mechanical strength at the welded portion E, and a sufficient driving force transmission function can be obtained.

  Further, since the ring gear 303 and the differential case 305 are positioned in the axial direction by the welded portion E, it is not necessary to use another positioning means, so that the positioning means and the mounting man-hour are not required, and an increase in cost can be avoided.

  Further, the ring gear 303 of this embodiment has a phosphoric acid coating treatment process on the surface of the ring gear 303 after the carburizing process before the joining process. When the surface of the ring gear 303 is subjected to a phosphoric acid coating, the gear meshing portion has good initial fit, and the seizure resistance is improved, and also has a rust prevention effect.

  In addition, the carburized steel ring gear 311 does not change in structure even if it is not subjected to the carbonization treatment in the above joining process, and a desired property is obtained. Therefore, an increase in cost associated with the carbonization treatment is avoided.

<Fifth Embodiment>
A power transmission device 401 according to a fifth embodiment, a torque transmission member joining structure used in the power transmission device 401, and a torque transmission member joining method will be described with reference to FIG. The upper part of FIG. 5 corresponds to the front of the vehicle in which the power transmission device 401 is used.

[Features of Joining Structure of Torque Transmission Member of Fifth Embodiment]
The joint structure of the torque transmission member is such that the left casing member 405 (first torque transmission member: spheroidal graphite cast iron: FCD) and the right casing member 407 (second torque transmission member: spheroidal graphite cast iron) constituting the differential case 403. : FCD) is welded F, and is joined (CMT welding) via a welding wire 7 (other member) made of an iron-based or stainless-based welding material having close affinity, and the right casing member 407 And the pinion shaft 323 (second torque transmission member: carburized steel) are joined at the weld G via a welding wire 7 (other member) of the same welding material having close affinity as described above (CMT welding). The pinion shaft 323 is positioned in the radial direction by the joining.

[Features of Joining Method of Torque Transmission Member of Fifth Embodiment]
In this torque transmission member joining method, the left casing member 405 and the right casing member 407 are joined by the welding wire 7 (CMT welding), and the right casing member 407 and the pinion shaft 323 are joined by the welding wire 7 ( CMT welding)
The pinion shaft 323 can be positioned in the radial direction by the joining.

  Even if the pinion shaft 323 is subjected to a surface treatment such as plating or a hardening heat treatment in a step before the welding step, the welding step can be performed without restriction.

[Features of power transmission device 401]
The power transmission device 401 includes a casing member 405, a casing member 407, and a pinion shaft 323 in the torque transmission path, and the casing member 405 and the casing member 407, and the casing member 407 and the pinion shaft 323 are claimed. It has the joining structure described in 1, 2, 4, 6 or is joined by the method described in claims 7, 8, 10 and 12.

[Configuration of Power Transmission Device 401]
A power transmission device 401 (differential device) is housed in a differential carrier and is rotated by the driving force of the engine. The differential case 403, a bevel gear type differential mechanism 313, a pair of multi-plate clutches 409, 409, The thrust block 411 is arranged between the drive shafts so as to be movable in the axial direction.

  Each multi-plate clutch 409 is disposed between the casing members 405 and 407 and the side gears 327 and 329, and the driving force of the engine that rotates the differential case 403 is the pinion shaft 323, the pinion gear 325, and the side gears 327 and 329. It is distributed to the left and right wheels via each drive shaft. Further, the multi-plate clutch 409 is fastened by the meshing reaction force of the side gears 327 and 329 generated at this time, and the differential of the differential mechanism 313 is limited.

[Effect of power transmission device 401]
The power transmission device 401 has the following effects.

  The casing member 405 and the casing member 407 are firmly joined by the welding wire 7 (CMT welding), and the casing member 407 and the pinion shaft 323 are firmly joined by the welding wire 7 (CMT welding). Since it becomes possible to join cast iron members (casing members 405 and 407: spheroidal graphite cast iron: FCD) and casing members 407 and pinion shafts 323 (carburized steel), bolts are used to join them. There is no need to use joining or beam welding.

  Therefore, problems such as the addition of bolt loosening prevention means and oil leakage prevention sealing means, an increase in the number of parts including bolts, and an increase in the axial dimension at the bolt fixing part, which occur when using bolted joints, are avoided. Is done.

  Further, since it is not necessary to join the cast iron member such as the casing member 407 and the pinion shaft 323 and the steel member by beam welding, the cost increase and the thermal deformation of the member due to the beam welding are avoided.

  Further, the differential case 403 has a large mechanical strength at the welded portion F, and a sufficient driving force transmission function can be obtained.

  Further, since the pinion shaft 323 is positioned in the radial direction at the welded portion G with respect to the differential case 403, and it is not necessary to use another positioning means, the positioning means and the mounting man-hour are not required, and an increase in cost can be avoided.

  In addition, the carburized steel pinion shaft 323 does not change in structure even if it is not subjected to the carburizing treatment in the joining step, and a desired property can be obtained. Therefore, an increase in cost due to the carburizing treatment is avoided.

<Sixth Embodiment>
A differential device 501 (power transmission device) according to a sixth embodiment, a torque transmission member joining structure and a torque transmission member joining method used in the differential device 501 will be described with reference to FIG. The upper part of FIG. 6 corresponds to the front of the vehicle in which the differential device 501 is used.

[Features of Torque Transmission Member Joining Structure of Sixth Embodiment]
The joint structure of the torque transmission member has a close affinity with the side gear 503 (torque transmission member: carburized steel) and the clutch ring 505 (meshing member: carburized steel on one side of the meshing portion) at the welded portion H. It is joined (CMT welding) from the welding direction 541 via a welding wire 7 (other member) of a welding material of iron or stainless steel,
The side gear 503 and the clutch ring 505 are positioned in the axial direction by the joining, and the side gear 503 and the clutch ring 505 are carburized steel.

[Features of Torque Transmission Member Joining Method of Sixth Embodiment]
The torque transmission member is joined by joining the side gear 503 and the clutch ring 505 via the welding wire 7 (CMT welding),
The side gear 503 and the clutch ring 505 can be positioned in the axial direction by the joining.

[Features of Differential Device 501]
The differential device 501 includes a side gear 503 and a clutch ring 505 in the torque transmission path, and the side gear 503 and the clutch ring 505 have the joint structure according to claim 1, 3, 4, 6, or It joins by the method of Claim 7, 9, 10, and 12. It is characterized by the above-mentioned.

[Configuration of Power Transmission Device 501]
The differential device 501 is housed in a differential carrier, and operates a differential case 507 that is rotationally driven by the driving force of the engine, a differential mechanism 509, a dog clutch 511 that locks the differential of the differential mechanism 509, and the dog clutch 511. It comprises an actuator 513 and the like.

  The differential case 507 includes a differential case main body 515 and left and right covers 521 and 523 fixed to the differential case main body 515 by bolts 517 and 519. The differential mechanism 509 includes a left side gear 525 and a right side gear 503, a long pinion gear 527, A short pinion gear, a long accommodation hole 529 provided in the differential case 507 for accommodating the pinion gear 527 and a short accommodation hole for accommodating the short pinion gear, each pinion gear meshes with each other, and the long pinion gear gear 527 is a right side gear. The short pinion gear meshes with the left side gear 525. The side gears 525 and 503 are connected to the left and right wheels via spline-connected drive shafts, and friction generated between the pinion gears and the receiving holes due to the meshing reaction force with the side gears 525 and 503. The differential limiting force is generated by the resistance.

  The dog clutch 511 is provided between the clutch ring 505 and the other clutch ring 531. When the actuator 513 is operated, the clutch ring 531 is pressed to the left and the dog clutch 511 is engaged with the differential mechanism 509. When the differential is locked and the actuator 513 is stopped, the clutch ring 531 is pushed back to the right by the return spring 533, and the engagement of the dog clutch 511 and the differential lock are released.

  The driving force of the engine that rotates the differential case 507 is distributed to the left and right wheels via the differential case 507, each pinion gear, the side gears 525, 503, and each drive shaft, and the differential is limited by the frictional resistance of the accommodation hole, The differential is locked by the dog clutch 511.

[Effect of differential device 501]
The differential device 501 can obtain the following effects.

  The side gear 503 and the clutch ring 505 are firmly joined by the welding wire 7 (CMT welding), and a sufficient driving force transmission function is obtained by the large mechanical strength at the weld H, and the differential by the dog clutch 511 is provided. The lock function is maintained normally.

  Further, it is not necessary to use bolt joining or beam welding to join the side gear 503 and the clutch ring 505, and therefore, bolt loosening prevention means and oil leakage prevention sealing means that are generated when bolt joining is used are added. Problems such as an increase in the number of parts including bolts and an increase in axial dimension at the bolt fixing portion are avoided, and cost increase and thermal deformation of the members due to beam welding are avoided.

  Further, since the side gear 503 and the clutch ring 505 are positioned in the axial direction by the welded portion H, it is not necessary to use another positioning means, so that the positioning means and the mounting man-hour are not required, and an increase in cost can be avoided.

  Further, the side gear 503 and the clutch ring 505, which are carburized steel, do not change in structure even if the carburizing treatment is not performed in the above joining process, and a desired property is obtained, so that an increase in cost due to the carburizing treatment is avoided. The

<Seventh embodiment>
A front differential 601 (power transmission device) according to the seventh embodiment, a torque transmission member joining structure and a torque transmission member joining method used for the front differential 601 will be described with reference to FIG. The upper part of FIG. 7 corresponds to the front of the vehicle in which the front differential 601 is used.

[Features of Joint Structure of Torque Transmission Member of Seventh Embodiment]
The joint structure of the torque transmission member is such that the differential case 603 (first torque transmission member: spheroidal graphite cast iron: FCD) and the sleeve 605 (second torque transmission member: tempered steel) are welded portions I, and have a close affinity. It is joined (CMT welded) at the weld I through a welding wire 7 (other member) of an iron or stainless steel welding material having
The differential case 603 and the sleeve 605 are positioned in the radial direction by the bonding, and the differential case 603 and the sleeve 605 can be positioned in the axial direction by the bonding.

[Features of Joining Method of Torque Transmission Member of Seventh Embodiment]
The torque transmission member is joined by joining the differential case 603 and the sleeve 605 via the welding wire 7 (CMT welding),
The differential case 603 and the sleeve 605 are positioned in the radial direction by the above-described joining,
The differential case 603 and the sleeve 605 are positioned in the axial direction by the above joining,
Even if the sleeve 605 is subjected to a surface treatment by tempering prior to the above-described joining, the joining process can be performed without causing a bearing due to the surface hardness.

[Features of front differential 601]
The front differential 601 has a differential case 603 and a sleeve 605 in the torque transmission path, and the differential case 603 and the sleeve 605 have the joint structure according to claim 1, 2, 3, 4, or 6, or It joins by the method of Claim 7, 8, 9, 10, 12.

[Configuration of front differential 601]
A front differential 601 (a differential device that distributes the driving force of the engine to the left and right front wheels) is housed in a transmission case, and a pair of the differential case 603 that is rotationally driven by the driving force of the engine via the output gear of the transmission, The pressure rings 607 and 607, a pair of cams, a bevel gear type differential mechanism 313, and a pair of multi-plate clutches 409 and 409 are configured. A spline portion 609 that transmits a driving force to the transfer side is provided on the outer periphery of the sleeve 605 welded to the differential case 603.

  The pressure rings 607 and 607 are connected to the differential case 603 so as to be axially movable. Each cam is provided between the pinion shaft 323 of the differential mechanism 313 and the pressure rings 607 and 607. The multi-plate clutches 409 and 409 are disposed between the differential case 603 and the side gears 327 and 329, and the side gears 327 and 329 are connected to the left and right front wheels via spline-connected drive shafts.

  The driving force of the engine that rotates the differential case 603 is input to the differential mechanism 313 via the pressure rings 607 and 607, each cam, and the pinion shaft 323, and is distributed to the left and right front wheels. Further, at this time, the pressure rings 607 and 607 are moved to the left and right by the cam thrust force generated by the respective cams, and the respective multi-plate clutches 409 are fastened, so that differential limitation is performed.

[Effect of front differential 601]
The front differential 601 has the following effects.

  The differential case 603 and the sleeve 605 are firmly joined by the welding wire 7 (CMT welding). Thus, the cast iron member (difference case 603: spheroidal graphite cast iron: FCD) and the tempered steel, which have been difficult to weld in the past, are joined. Therefore, it is not necessary to weld them by using beam welding or the like, and cost increase and thermal deformation of the member due to beam welding are avoided.

  In addition, excessive quality when the entire differential case is made of tempered steel or carburized steel is avoided, and the induction hardening of the spline portion 609 when the entire differential case is cast becomes unnecessary, and the cost is reduced accordingly.

  Further, the differential case 603 and the sleeve 605 can obtain a large mechanical strength at the welded portion I, and a sufficient driving force transmission function can be obtained.

  Further, the differential case 603 and the sleeve 605 are positioned in the radial direction and the axial direction at the welded portion I, respectively, and it is not necessary to use separate positioning means. It is done.

However, since the structure does not change and the desired properties are obtained, an increase in cost associated with the carbon-proof treatment is avoided.

  Note that carburized steel may be used for the sleeve 605, and even in this case, the same effect as the sleeve 605 of the tempered steel can be obtained.

<Eighth Embodiment>
With reference to FIG. 8, a transfer structure 701 (power transmission device) according to an eighth embodiment, a torque transmission member bonding structure used in the transfer 701, and a torque transmission member bonding method will be described. The upper part of FIG. 8 corresponds to the front of the vehicle in which the transfer 701 is used.

[Features of Joining Structure of Torque Transmission Member of Eighth Embodiment]
The joint structure of the torque transmission member is such that the hollow shaft 703 (torque transmission member: spheroidal graphite cast iron: FCD) and the ring gear 705 (meshing member on one side of the meshing portion: bevel gear: carburized steel) are welded portions J It is joined (CMT welding: fillet weld) through a welding wire 7 (other member) made of an iron or stainless steel welding material having a good affinity.
The hollow shaft 703 and the ring gear 705 can be positioned in the axial direction by the joining.

[Features of Joining Method of Torque Transmission Member of Eighth Embodiment]
This torque transmission member is joined by joining the hollow shaft 703 and the ring gear 705 via the welding wire 7 (CMT welding),
The hollow shaft 703 and the ring gear 705 are positioned in the axial direction by the above-mentioned joining,
Even if the ring gear 705 is subjected to a surface treatment by carburization prior to the joining, the welding process can be performed without hindrance. Since carburized steel is used for the ring gear 705, the same effect as that of the fourth embodiment can be obtained.

[Features of Transfer 701]
The transfer 701 includes a hollow shaft 703 and a ring gear 705 in the torque transmission path, and the hollow shaft 703 and the ring gear 705 have the joint structure according to claim 1, 3, 4, or 6, or It is joined by the method according to claim 7, 9, 10, 12.

[Configuration of Transfer 701]
The transfer 701 is housed in a transfer case 707, and a front differential (for example, the front differential 601 of the seventh embodiment) that is rotationally driven by the driving force of the engine is disposed on the left side of the transfer 701. The transfer 701 includes the hollow shaft 703 and the ring gear 705, and a drive pinion shaft 711 in which a drive pinion gear 709 (another bevel gear) that meshes with the ring gear 705 and forms a direction change gear set is integrally formed at the front end thereof. Further, the drive pinion shaft 711 includes a flange member 715 that is secured to the rear end by a nut 713 and is connected to the rear differential side via a rear wheel side power transmission system.

  The hollow shaft 703 is supported on the transfer case 707 by bearings 717 and 719 that receive thrust force, and the drive pinion shaft 711 is supported on the transfer case 707 by bearings 721 and 723 that receive thrust force. Further, the hollow shaft 703 is provided with a spline portion 725 for connecting to the hollow connecting shaft splined to the differential case of the front differential, and the right drive shaft 727 of the front differential passes therethrough.

  The driving force of the engine, which is input from the front differential side and rotates the hollow shaft 703, is transmitted from the direction change gear set (gears 705 and 709), the drive pinion shaft 711 and the flange member 715 to the rear differential via the rear wheel side power transmission system. And distributed to the left and right rear wheels.

[Effect of transfer 701]
The transfer 701 has the following effects.

  The hollow shaft 703 and the ring gear 705 are firmly joined by the welding wire 7 (CMT welding), and thus the cast iron member (hollow shaft 703: spheroidal graphite cast iron: FCD) that has been difficult to weld in the past can be joined. Since it became possible, it is not necessary to use bolting or beam welding to join them.

  Therefore, problems such as the addition of bolt loosening prevention means and oil leakage prevention sealing means, an increase in the number of parts including bolts, and an increase in the axial dimension at the bolt fixing part, which occur when using bolted joints, are avoided. In addition, the cost increase associated with beam welding and the thermal deformation of the member are avoided.

  Further, the hollow shaft 703 and the ring gear 705 are firmly joined by the weld J, and a sufficient driving force transmission function can be obtained due to the large mechanical strength.

  Further, since the hollow shaft 703 and the ring gear 705 are positioned in the axial direction by the welded portion J, it is not necessary to use another positioning means, and therefore, the positioning means and the mounting man-hour are not required, and an increase in cost is avoided. It is done.

  In addition, since the structure of the carburized steel ring gear 705 does not change even if the carburizing treatment is not performed and the desired properties are obtained in the joining process, an increase in cost associated with the carburizing treatment is avoided.

<Ninth Embodiment>
A power transmission device 801 according to a ninth embodiment, a torque transmission member joining structure used in the power transmission device 801, and a torque transmission member joining method will be described with reference to FIG. The power transmission device 801 is used in a hybrid four-wheel drive vehicle, and this four-wheel drive vehicle is composed of a front wheel side power system using an engine as a prime mover and a rear wheel side power system using an electric motor as a prime mover. The power transmission device 801 is used in a power system on the rear wheel side. The upper part of FIG. 9 corresponds to the front of this four-wheel drive vehicle.

[Features of Joining Structure of Torque Transmission Member of Ninth Embodiment]
The joint structure of the torque transmission member is such that the outer differential case 803 (torque transmission member: spheroidal graphite cast iron: FCD) and the ring gear 805 (meshing member on one side of the meshing part: carburized steel) are welded parts K and have a close affinity. It is joined (CMT welding) from a welding direction 841 through a welding wire 7 (other member) of a ferrous or stainless steel welding material having properties.
The outer differential case 803 and the ring gear 805 are positioned in the axial direction by the joining,
The ring gear 805 is surface-treated by carburizing prior to the joining.

[Features of Joining Method of Torque Transmission Member of Ninth Embodiment]
The torque transmission member is joined by joining the outer differential case 803 and the ring gear 805 via the welding wire 7 (CMT welding),
The outer differential case 803 and the ring gear 805 are positioned in the axial direction by the above joining,
Even if the ring gear 805 is subjected to a surface treatment prior to the joining, the welding process can be performed without hindrance.

[Features of power transmission device 801]
The power transmission device 801 has an outer differential case 803 and a ring gear 805 in the torque transmission path, and does the outer differential case 803 and the ring gear 805 have the joint structure according to claim 1, 3, 4, 6? Or it is joined by the method of Claim 7, 9, 10, and 12. It is characterized by the above-mentioned.

[Configuration of Power Transmission Device 801]
The power transmission device 801 is housed in a carrier 807, and is an input shaft 809 that is rotationally driven by an electric motor, an intermediate shaft 811, a preceding reduction gear set 817 including a small diameter gear 813 and a large diameter gear 815, and a small diameter gear. 819 and a rear reduction gear set 821 including a ring gear 805 (large diameter gear), a rear differential 823, and the like. The input shaft 809 is supported on the carrier 807 by ball bearings 825 and 827, and the intermediate shaft 811 is supported on the carrier 807 by a ball bearing 829 and a needle bearing 831. The small diameter gear 813 is formed on the input shaft 809, the large diameter gear 815 is fixed to the intermediate shaft 811, the small diameter gear 819 is formed on the intermediate shaft 811, and the ring gear 805 is welded to the outer differential case 803 as described above. ing.

  The rear differential 823 includes an outer differential case 803, an inner differential case 833, a main clutch 13, a pilot clutch 15, an electromagnetic magnet 17, a cam ring 19, a ball cam 21, a pressure plate 23, an armature 25, and a differential mechanism 313. And a controller.

  The outer differential case 803 and the ring gear 805 are supported on the outer periphery of the inner differential case 833 by a double row ball bearing 835, the left end of the inner differential case 833 is supported by the carrier 807 by the ball bearing 837, and the right end is supported by the ball bearing 837 and the electromagnetic magnet 17. Is supported by the carrier 807 through the core 49. The main clutch 13 is disposed between the outer differential case 803 and the inner differential case 833, the pilot clutch 15 is disposed between the outer differential case 803 and the cam ring 19, and the pinion shaft 323 of the differential mechanism 313 is coupled to the inner differential case 833. .

  The controller performs excitation of the electromagnetic magnet 17, excitation current control, and excitation stop. When the electromagnetic magnet 17 is excited, the outer differential case 803 and the inner differential case 833 are connected by the main clutch 13, and the driving force of the electric motor is decelerated. The gear sets 817 and 821 are decelerated to the traveling rotational speed range of the wheels (rear wheels), transmitted to the differential mechanism 313, and distributed to the left and right rear wheels. When the excitation of the electromagnetic magnet 17 is stopped, the connection of the main clutch 13 is released and the rear wheel side is disconnected from the electric motor.

  The controller also drives the electric motor, adjusts the rotation speed, and stops driving. During normal driving, the controller stops the electric motor and cuts off the driving force by the main clutch 13 to stop the operation of the rear wheel side power system. Thus, the vehicle is brought into a two-wheel drive state by the front wheel side power system. When a large driving force is required, the electric motor is driven, the main clutch 13 is connected, the rear wheel side power system is operated, and the vehicle is brought into a four-wheel drive state.

[Effect of power transmission device 801]
The power transmission device 801 can obtain the following effects.

  The outer differential case 803 and the ring gear 805 are firmly joined by the welding wire 7 (CMT welding), and it is possible to join a cast iron member (outer differential case 803: spheroidal graphite cast iron: FCD) that has been difficult to weld in the past. Therefore, it is not necessary to use bolting or beam welding to join them.

  Therefore, problems such as the addition of bolt loosening prevention means and oil leakage prevention sealing means, an increase in the number of parts including bolts, and an increase in the axial dimension at the bolt fixing part accompanying the bolt joining can be avoided. Cost increase and thermal deformation of the member due to beam welding are avoided.

  Further, the outer differential case 803 and the ring gear 805 are firmly joined at the welded portion K, and a sufficient driving force transmission function can be obtained due to the large mechanical strength.

  Further, since the outer differential case 803 and the ring gear 805 are positioned in the axial direction by the welded portion K, it is not necessary to use another positioning means, and therefore, the positioning means and the mounting man-hour are not required, and an increase in cost is avoided. It is done.

  In addition, since the structure of the carburized steel ring gear 805 does not change even if the carburizing treatment is not performed and the desired properties are obtained in the above joining process, an increase in cost associated with the carburizing treatment is avoided.

[Other Embodiments Included within the Scope of the Present Invention]
In the present invention, the joining of the torque transmission member and the meshing member (CMT welding) may be not a full circumference welding but a jump welding such as a staggered welding as long as a desired strength can be obtained. .

It is sectional drawing which shows the power transmission device 1 of 1st Embodiment. It is sectional drawing which shows the power transmission device 101 of 2nd Embodiment. It is sectional drawing which shows the power transmission device 201 of 3rd Embodiment. It is sectional drawing which shows the power transmission device 301 of 4th Embodiment. It is sectional drawing which shows the power transmission device 401 of 5th Embodiment. It is sectional drawing which shows the differential apparatus 501 of 6th Embodiment. It is sectional drawing which shows the front differential 601 of 7th Embodiment. It is sectional drawing which shows the transfer 701 of 8th Embodiment. It is sectional drawing which shows the power transmission device 801 of 9th Embodiment. It is sectional drawing of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power transmission device 3 Rotor (1st torque transmission member: Magnetic material: Low carbon steel)
5 Cylindrical member (second torque transmission member: non-magnetic material: aluminum alloy)
7 Welding wire (other members with close affinity)
101 Power transmission device 201 Power transmission device 203 First hub (first torque transmission member: carburized steel)
205 Second hub (second torque transmission member: nonmagnetic material: austenitic stainless steel)
301 Power transmission device 303 Ring gear (meshing member on one side of meshing part: carburized steel)
305 Differential case (Torque transmission member: Spheroidal graphite cast iron: FCD)
401 Power transmission device 405 casing member (first torque transmission member: spheroidal graphite cast iron: FCD)
407 Casing member (second torque transmission member: spheroidal graphite cast iron: FCD)
323 Pinion shaft (second torque transmission member: carburized steel)
501 Differential device (power transmission device)
503 Side gear (torque transmission member: carburized steel)
505 Clutch ring (engagement member on one side of meshing part: carburized steel)
601 Front differential (power transmission device)
603 differential case (first torque transmission member: spheroidal graphite cast iron: FCD)
605 sleeve (second torque transmission member: tempered steel)
701 Transfer (Power transmission device)
703 Hollow shaft (Torque transmission member: Spheroidal graphite cast iron: FCD)
705 Ring gear (meshing member on one side of meshing part: bevel gear: carburized steel)
801 Power transmission device 803 Outer differential case (torque transmission member: spheroidal graphite cast iron: FCD)
805 Ring gear (meshing member on one side of meshing part: carburized steel)

Claims (14)

A joining structure of torque transmitting members, wherein the first torque transmitting member and the second torque transmitting member are joined via other members having close affinity to each other. The joint structure of the torque transmission member according to claim 1,
The joining structure of the torque transmission member, wherein the first torque transmission member and the second torque transmission member are positioned in a radial direction by the joining. The joint structure of the torque transmission member according to claim 1,
The joining structure of the torque transmission member, wherein the first torque transmission member and the second torque transmission member are positioned in the axial direction by the joining. The joint structure of the torque transmission member according to any one of claims 1 to 3,
At least one of the first torque transmission member and the second torque transmission member is subjected to a surface treatment prior to the joining. The joint structure of the torque transmission member according to any one of claims 1 to 3,
One of the first torque transmission member and the second torque transmission member is an aluminum alloy, the other is an iron alloy, and the iron alloy is galvanized prior to the joining. Torque transmission member joining structure. The joint structure of the torque transmission member according to any one of claims 1 to 5,
One or both of the first torque transmission member and the second torque transmission member are carburized steel, tempered steel, or cast iron. A method for joining torque transmission members, wherein the first torque transmission member and the second torque transmission member are joined via other members having close affinity with each other. It is a joining method of the torque transmission member according to claim 7,
A method for joining torque transmission members, wherein the first torque transmission member and the second torque transmission member are positioned in a radial direction by the joining. It is a joining method of the torque transmission member according to claim 7,
A method for joining torque transmitting members, wherein the first torque transmitting member and the second torque transmitting member are positioned in the axial direction by the joining. A torque transmission member joining method according to any one of claims 7 to 9,
A method for joining torque transmission members, wherein at least one of the first torque transmission member and the second torque transmission member is subjected to a surface treatment prior to the joining. A method for joining torque transmitting members according to any one of claims 7 to 10,
One of the first torque transmission member and the second torque transmission member is an aluminum alloy and the other is an iron alloy, and the iron alloy is galvanized prior to the joining. Torque transmission member joining method. A method for joining torque transmitting members according to any one of claims 7 to 11,
A method for joining torque transmission members, wherein carburized steel, tempered steel, or cast iron is used for one or both of the first torque transmission member and the second torque transmission member. A power transmission device having a first torque transmission member and a second torque transmission member in a torque transmission path, wherein the first torque transmission member and the second torque transmission member are the claims. A power transmission device having the joining structure according to any one of claims 1 to 6, or joined by the method according to any one of claims 7 to 12. The power transmission device having a torque transmission member and a meshing member on one side of the meshing portion in a torque transmission path, wherein the torque transmission member and the meshing member are according to the first to sixth aspects. A power transmission device having a joint structure or joined by the method according to claim 7 to claim 12.

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