Method for manufacturing drum portion of power transmission device and power transmission device

Abstract

The present invention provides a method for manufacturing a drum portion of a power transmission device, which can achieve a reduction in the cutting portion and processing time when forming the drum portion. The power transmission device has a transmission that changes the speed of power input to an input member and transmits it to an output member, the transmission has a drum portion with a bottom cylinder, the drum portion is connected to an intermediate member and an output member in a power transmission path from the input member to the output member, the drum portion has a parking gear of a parking device, a first connecting member connected to the intermediate member and the parking gear, and a second connecting member connected to the parking gear and the output member via a joint, wherein in the method for manufacturing the drum portion of the power transmission device, the first connecting member is formed, and the second connecting member is formed along with a stamping process, and the parking gear engages the parking gear with the second connecting member, and connects the parking gear with the first connecting member.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a drum portion of a power transmission device and the power transmission device. Background Art

[0002] Conventionally, as such a power transmission device, there has been proposed a power transmission device having an automatic transmission that changes the speed of power input to an input member and transmits the power to an output member (for example, see Patent Document 1). The automatic transmission has a bottomed cylindrical drum portion that connects a ring gear of a planetary gear mechanism to an output member, and the drum portion has a cylindrical first connecting member that is integrally formed with the ring gear, a parking gear of a parking device, and a second connecting member that is integrally formed with the parking gear, is engaged with the first connecting member, and is fixed to the output member by welding.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2014-190485

[0004] In the above-mentioned power transmission device, the second connecting member of the drum is integrally formed with the parking gear, so the entire second connecting member needs to be formed by cutting. Therefore, there are many cutting parts and the processing time becomes longer, which leads to an increase in material costs and processing costs. Summary of the invention

[0005] The main purpose of the method for manufacturing a drum portion of a power transmission device and the power transmission device of the present invention is to achieve reduction in the amount of cutting and processing time when forming the drum portion.

[0006] The method for manufacturing a drum portion of a power transmission device and the power transmission device of the present invention adopt the following technical solutions in order to achieve the above-mentioned main objects.

[0007] The method for manufacturing the drum portion of the power transmission device of the present invention,

[0008] The power transmission device includes a transmission that changes the speed of power input to an input member and transmits the power to an output member.

[0009] The transmission has a bottomed cylindrical drum portion, the drum portion being connected to an intermediate member in a power transmission path from the input member to the output member and the output member.

[0010] The drum portion includes a parking gear of a parking device, a first connecting member connected to the intermediate member and the parking gear, and a second connecting member connected to the parking gear and the output member via a joint, wherein:

[0011] The method for manufacturing the drum portion of the power transmission device comprises:

[0012] Step (a), forming the first connecting member, forming the second connecting member by press working, and forming the parking gear; and

[0013] The step (b) is to engage the parking gear with the second connecting member and connect the parking gear with the first connecting member.

[0014] In the manufacturing method of the drum portion of the power transmission device of the present invention, a first connecting member is formed, and a second connecting member is formed by stamping, and a parking gear is formed, the parking gear is engaged with the second connecting member, and the parking gear is connected to the first connecting member. As a result, the second connecting member and the parking gear can be formed separately by stamping (cutting can be performed on the predetermined engagement portion of the second connecting member that engages with the parking gear or the output member as required). Therefore, compared with the case where the second connecting member and the parking gear are integrally formed by cutting, the cutting portion and processing time when forming the second connecting member can be reduced, and further the cutting portion and processing time when forming the drum portion can be reduced. As a result, the material cost and processing cost when forming the drum portion can be reduced.

[0015] The power transmission device of the present invention has a transmission that changes the speed of power input to an input member and transmits the power to an output member, wherein:

[0016] The transmission has a bottomed cylindrical drum portion, the drum portion being connected to an intermediate member in a power transmission path from the input member to the output member and the output member.

[0017] The drum portion includes a parking gear of a parking device, a first connecting member connected to the intermediate member and the parking gear, and a second connecting member as a press-formed product connected to the parking gear and the output member via a joint.

[0018] In the power transmission device of the present invention, the transmission has a drum portion with a bottom cylinder, which is connected to the intermediate component and the output component in the power transmission path from the input component to the output component, and the drum portion has a parking gear of the parking device, a first connecting component connected to the intermediate component and the parking gear, and a second connecting component as a stamping workpiece connected to the parking gear and the output component via a joint. Thus, the second connecting component and the parking gear can be formed separately by stamping (cutting can be performed on the predetermined joint portion of the second connecting component that is engaged with the parking gear or the output component as required). Therefore, compared with the case where the second connecting component and the parking gear are integrally formed by cutting, the cutting part and processing time when forming the second connecting component can be reduced, and further the cutting part and processing time when forming the drum can be reduced. As a result, the material cost and processing cost when forming the drum can be reduced. Here, the joint can also be a welding part. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the power transmission device 20 of the present invention.

[0020] Figure 2 It is an operation table showing the relationship between each shift speed of the automatic transmission 25 and the operating states of the clutches C1 to C4 and the brakes B1 and B2.

[0021] Figure 3 It is a speed diagram illustrating the relationship between the rotation speeds of the rotating elements constituting the automatic transmission 25 .

[0022] Figure 4 It is a partial cross-sectional view showing the periphery of the drum portion 40 of the power transmission device 20 .

[0023] Figure 5 It is a process diagram showing the manufacturing process of the drum part 40.

[0024] Figure 6 It is an explanatory diagram showing a state of manufacturing the drum part 40 .

[0025] Figure 7 It is a partial cross-sectional view showing the periphery of the drum portion 40B.

[0026] Figure 8 It is a process diagram showing the manufacturing process of the drum part 40B.

[0027] Fig. 9 It is an explanatory diagram showing the state of manufacturing the drum part 40B.

[0028] Description of reference numerals:

[0029] 20 power transmission device, 22 gearbox, 23 starting device, 23c lock-up clutch, 23d damping mechanism, 23o one-way clutch, 23p pump impeller, 23s guide wheel, 23t turbine, 24 oil pump, 25 automatic transmission, 26 input member, 27 output member, 271 tubular portion, 272 flange portion, 30 first planetary gear mechanism, 31 sun gear, 32 ring gear, 33a, 33b pinion, 34 planet carrier, 35 second planetary gear mechanism, 36a first sun gear, 36b second sun gear, 37 ring gear, 37a spline, 38a short pinion, 38b long pinion, 39 planet carrier, 40, 40B drum portion, 40A, 40C bottomed cylindrical component, 41, 41B parking gear, 411, 411B gear portion, 412, 412B annular portion, 413, 413B, 414B flange portion, 415 step portion, 415B first step portion, 416B second step portion, 42, 42B first connecting component, 421, 421B cylindrical portion, 422, 422B flange portion, 423 comb tooth portion, 423B spline, 424, 424B recessed portion, 43, 43B second connecting component, 431, 431B annular portion, 432 outer cylindrical portion, 433 inner cylindrical portion, 433B frustum cone portion, 50 snap ring, B1, B2 brakes, C1~C4 clutches. DETAILED DESCRIPTION

[0030] Next, a mode for carrying out the present invention will be described with reference to the drawings.

[0031] Figure 1 : is a schematic structural diagram of the power transmission device 20 of the present invention. The power transmission device 20 shown in the figure is connected to the crankshaft of the engine (not shown) as the driving source mounted longitudinally on the front part of the rear-wheel drive vehicle, and can transmit the power from the engine to the left and right driving wheels (rear wheels) (not shown). As shown in the figure, the power transmission device 20 includes a gearbox (stationary component) 22, a starting device (fluid transmission device) 23 accommodated in the gearbox 22, an oil pump 24, an automatic transmission 25, a differential gear (differential mechanism) (not shown), etc.

[0032] The starting device 23 is configured as a hydraulic torque converter, which includes a pump impeller 23p on the input side connected to the crankshaft of the engine, a turbine 23t on the output side connected to the input member 26 of the automatic transmission 25, a stator 23s disposed inside the pump impeller 23p and the turbine 23t and rectifying the flow of the working oil from the turbine 23t to the pump impeller 23p, a one-way clutch 23o that limits the rotation direction of the stator 23s to one direction, a lockup clutch 23c, a damper mechanism 23d, etc. However, the starting device 23 may be configured as a hydraulic coupling without the stator 23s.

[0033] The oil pump 24 is configured as a gear pump, and includes a pump assembly including a pump body and a pump cover, an external gear connected to the pump impeller 23p of the starting device 23 via a hub, an internal gear meshing with the external gear, etc. The oil pump 24 is driven by power from the engine, and sucks the working oil (ATF) stored in an oil pan (not shown) and pressurizes it to a hydraulic control device (not shown).

[0034] The automatic transmission 25 is constructed as an 8-speed transmission. Figure 1 As shown, in addition to the input member 26, the output member 27, the double pinion type first planetary gear mechanism 30, the Ravigneaux type second planetary gear mechanism 35, four clutches C1 to C4 for changing the power transmission path from the input side to the output side, and two brakes B1 and B2 are included. The power transmitted from the input member 26 to the output member 27 is transmitted to the left and right drive wheels via the differential gear and the drive shaft (not shown).

[0035] The first planetary gear mechanism 30 of the automatic transmission 25 has: a sun gear 31 as an external gear; a ring gear 32 as an internal gear, which is arranged on a concentric circle with the sun gear 31; and a planetary carrier 34, which holds a plurality of sets of two pinions 33a and 33b meshing with each other, one meshing with the sun gear 31 and the other meshing with the ring gear 32, so as to be able to rotate freely (freely rotate) and freely revolve. As shown in the figure, the sun gear 31 of the first planetary gear mechanism 30 is fixed to the transmission case 22, and the planetary carrier 34 of the first planetary gear mechanism 30 is connected to the input member 26 in a manner that can rotate integrally. The first planetary gear mechanism 30 is configured as a so-called reduction gear, which reduces the power transmitted to the planetary carrier 34 as an input member and outputs it from the ring gear 32 as an output member.

[0036] The second planetary gear mechanism 35 of the automatic transmission 25 includes: a first sun gear 36a and a second sun gear 36b as external gears; a ring gear 37 as an internal gear, which is arranged on a concentric circle with the first sun gear 36a and the second sun gear 36a, 36b; a plurality of short pinions 38a, which mesh with the first sun gear 36a; a plurality of long pinions 38b, which mesh with the second sun gear 36b and the plurality of short pinions 38a, and mesh with the ring gear 37; and a planet carrier 39, which holds the plurality of short pinions 38a and the plurality of long pinions 38b so that they can rotate freely (freely rotate) and revolve freely. The ring gear 37 of the second planetary gear mechanism 35 is connected to the output member 27 via a drum 40.

[0037] The clutch C1 is a multi-plate friction type hydraulic clutch (friction engagement member) having a hydraulic servo composed of a piston, a plurality of friction plates and a release plate, an oil chamber supplied with working oil, etc., and can fasten and release the fastening connection between the ring gear 32 of the first planetary gear mechanism 30 and the first sun gear 36a of the second planetary gear mechanism 35. The clutch C2 is a multi-plate friction type hydraulic clutch having a hydraulic servo composed of a piston, a plurality of friction plates and a release plate, an oil chamber supplied with working oil, etc., and can fasten and release the fastening connection between the input member 26 and the planetary carrier 39 of the second planetary gear mechanism 35. The clutch C3 is a multi-plate friction type hydraulic clutch having a hydraulic servo composed of a piston, a plurality of friction plates and a release plate, an oil chamber supplied with working oil, etc., and can fasten and release the fastening connection between the ring gear 32 of the first planetary gear mechanism 30 and the second sun gear 36b of the second planetary gear mechanism 35. Clutch C4 is a multi-plate friction hydraulic clutch having a hydraulic servo composed of a piston, multiple friction plates and separation plates, an oil chamber supplied with working oil, etc. It can fasten the planetary carrier 34 of the first planetary gear mechanism 30 and the second sun gear 36b of the second planetary gear mechanism 35, and can release the fastening connection between the two.

[0038] The brake B1 is a multi-plate friction type hydraulic brake, and has a hydraulic servo composed of a plurality of friction plates and separator plates, an oil chamber supplied with working oil, etc., and can fix the second sun gear 36b of the second planetary gear mechanism 35 to the transmission case 22 so that the second sun gear 36b cannot rotate, and can release the fixation of the second sun gear 36b relative to the transmission case 22. The brake B2 is a multi-plate friction type hydraulic brake, and has a hydraulic servo composed of a plurality of friction plates and separator plates, an oil chamber supplied with working oil, etc., and can fix the planetary carrier 39 of the second planetary gear mechanism 35 to the transmission case 22 so that the planetary carrier 39 cannot rotate, and can release the fixation of the planetary carrier 39 relative to the transmission case 22.

[0039] The clutches C1 to C4 and the brakes B1 and B2 are operated by supply and discharge of hydraulic oil by a hydraulic control device (not shown). Figure 2 is an operation table showing the relationship between each gear stage of the automatic transmission 25 and the operating states of the clutches C1 to C4 and the brakes B1 and B2. Figure 3 The speed diagram exemplifies the relationship between the rotational speeds of the rotating elements constituting the automatic transmission 25. The automatic transmission 25 converts the clutches C1 to C4 and the brakes B1 and B2 into Figure 2 The state shown in the operation table of the present invention provides the forward 1st to 8th speeds and the reverse 1st and 2nd speeds. In addition, at least one of the clutches C1 to C4 and the brakes B1 and B2 may be an engaging member such as a dog clutch.

[0040] Figure 4 2 is a partial cross-sectional view showing the periphery of the drum portion 40 of the power transmission device 20. As shown in the figure, a spline 37a is formed on the outer peripheral surface of the ring gear 37 of the second planetary gear mechanism 35. In addition, an annular recess 37b is formed on the outer peripheral surface of the spline 37a, which is recessed radially inward over the entire circumference.

[0041] The output member 27 includes a cylindrical portion 271 and an axial end portion ( Figure 4 The flange portion 272 extends radially outward (left end portion in the figure). The cylindrical portion 271 is connected to the left and right drive wheels via a differential gear and a drive shaft (not shown).

[0042] The drum 40 connects the ring gear 37 of the second planetary gear mechanism 35 to the output member 27, and includes a parking gear 41 of the parking device, a first connecting member 42 connected to the ring gear 37 and connected (fixed) to the parking gear 41, and a second connecting member 43 connected (fixed) to the parking gear 41 and the output member 27. The parking device is configured as a device that locks and releases the output member 27 of the automatic transmission 25, that is, performs parking lock and parking lock release.

[0043] The parking gear 41 is a forged part formed by forging, quenching, cutting, etc., and comprises: a cylindrical gear portion 411 having a plurality of external teeth; an annular ring portion 412 extending from one end portion ( Figure 4 and an annular flange portion 413, from the other axial end portion of the gear portion 411 ( Figure 4 The parking gear 41 is formed by a gear portion 411 having an axial end face (the right end portion in the middle) extending radially inward. In addition, as forging, hot forging or cold forging can be cited, and as quenching, high-frequency quenching or carburizing quenching can be cited. Figure 4 The left end surface in the middle and the outer peripheral surface of the annular portion 412 form a step portion 415.

[0044] The first connecting member 42 is a stamped product roughly formed by stamping, and has a cylindrical portion 421 and an axial end portion ( Figure 4 The flange portion 422 is an annular flange portion 422 extending radially inward from the right end portion in the center of the parking gear 41. The inner circumferential surface of the flange portion 422 is fixed to the outer circumferential surface of the annular portion 412 of the parking gear 41 by welding in a state where the flange portion 422 and the step portion 415 are in axial contact (a state where the axial end surface of the flange portion 422 and the axial end surface of the gear portion 411 of the parking gear 41 are in mutual contact). Therefore, the inner circumferential surface of the flange portion 422 and the outer circumferential surface of the annular portion 412 of the parking gear 41 are connected via a welded portion (a joint formed by welding).

[0045] A comb-tooth portion 423 in the shape of a comb is formed at the other axial end of the cylindrical portion 421, and a recess 424 recessed radially outward is formed on the inner circumferential surface of each tooth of the comb-tooth portion 423. The comb-tooth portion 423 is formed by cutting. The ring gear 37 of the second planetary gear mechanism 35 and the first connecting member 42 are connected to each other by fitting the spline 37a formed on the outer circumferential surface of the ring gear 37 with the comb-tooth portion 423 of the first connecting member 42, and a retaining ring 50 is sandwiched between the annular recess 37b of the spline 37a and the recess 424 of the comb-tooth portion 423. At this time, the first connecting member 42 side ( Figure 4 A gap connecting the inside and outside of the drum portion 40 in the radial direction is formed between the end surface (on the right side in the figure) and two adjacent teeth of the comb tooth portion 423.

[0046] The second connection member 43 is a stamped product formed by stamping, and has an annular ring portion 431, a second planetary gear mechanism 35 side ( Figure 4 The outer cylindrical portion 432 is a cylindrical portion that extends from the inner circumference of the annular portion 431 to the left side thereof, and the inner cylindrical portion 433 is a cylindrical portion that extends from the inner circumference of the annular portion 431 to the same side as the outer cylindrical portion 432 in the axial direction. The outer diameter of the outer cylindrical portion 432 is designed to be smaller than the inner diameter of the flange portion 422 of the first connecting member 42. The outer circumferential surface of the free end portion of the outer cylindrical portion 432 is fixed to the inner circumferential surface of the flange portion 413 of the parking gear 41 by welding. The inner circumferential surface of the free end portion of the inner cylindrical portion 433 is fixed to the outer circumferential surface of the flange portion 272 of the output member 27 by welding. Therefore, the outer circumferential surface of the free end portion of the outer cylindrical portion 432 is connected to the inner circumferential surface of the flange portion 413 of the parking gear 41 via a welding portion, and the inner circumferential surface of the free end portion of the inner cylindrical portion 433 is connected to the outer circumferential surface of the flange portion 272 of the output member 27 via a welding portion.

[0047] In the present embodiment, since the first connection member 42 of the drum 40 is formed separately from the ring gear 37 and the parking gear 41 of the second planetary gear mechanism 35, the first connection member 42 can be formed as a stamped product by stamping, and the inner peripheral surface of the flange portion 422 (the welding scheduled portion to be welded with the annular portion 412 of the parking gear 41) and the comb tooth portion 423 (the fitting scheduled portion to be fitted with the spline 37a of the ring gear 37) can be cut as needed. As a result, compared with the case where the first connection member 42 is integrally formed with the ring gear 37 and the parking gear 41 by cutting (the whole is formed by cutting), the cutting part and the processing time can be reduced. As a result, the material cost and the processing cost can be reduced.

[0048] Furthermore, in the first connecting member 42 and the parking gear 41, the inner circumferential surface of the flange portion 422 of the first connecting member 42 and the outer circumferential surface of the annular portion 412 of the parking gear 41 are fixed to each other by welding in a state where the flange portion 422 of the first connecting member 42 and the step portion 415 are in axial contact. Therefore, the first connecting member 42 and the parking gear 41 can be easily positioned and welded in the axial direction.

[0049] In addition, since the second connection member 43 of the drum 40 is formed separately from the parking gear 41, it is sufficient to form the second connection member 43 as a stamped product by stamping, and to perform cutting on the outer peripheral surface of the free end of the outer cylinder 432 (the welding scheduled portion to be welded to the flange 413 of the parking gear 41) and the inner peripheral surface of the free end of the inner cylinder 433 (the welding scheduled portion to be welded to the flange 272 of the output member 27) as needed. As a result, compared with the case where the second connection member 43 and the parking gear 41 are integrally formed by cutting (formed as a whole by cutting), the cutting part and the processing time can be reduced. As a result, the material cost and the processing cost can be reduced.

[0050] Furthermore, a gap is formed between the end surface of the first connecting member 42 side of the ring gear 37 in the axial direction and two adjacent teeth of the comb tooth portion 423, which communicates the inside and outside of the drum portion 40 in the radial direction. Therefore, the gap can function as an oil hole for passing the working oil. As a result, the manufacturing process can be reduced compared to the case where an oil hole is separately provided.

[0051] Furthermore, since the outer tube portion 432 and the inner tube portion 433 of the second connection member 43 extend from the annular portion 431 to the same side in the axial direction, the second connection member 43 of a stub shaft and, in turn, the drum portion 40 of a stub shaft can be realized.

[0052] The drum portion 40 is manufactured, for example, as follows. Figure 5 4 is a process diagram showing the manufacturing process of the drum portion 40. Figure 6 40 is an explanatory diagram showing the manufacturing process of the drum portion 40. Figure 6 right Figure 5 The manufacturing process of the drum portion 40 will be described.

[0053] First, if Figure 6As shown in (A), the bottomed cylindrical member 40A including the first connecting member 42 and the second connecting member 43 is integrally formed by stamping (process S100), and the parking gear 41 is formed separately from the bottomed cylindrical member 40A by forging, quenching, and cutting (process S110). The bottomed cylindrical member 40A has: an annular outer annular portion 401A, an outer cylindrical portion 402A extending axially cylindrically from the outer periphery of the outer annular portion 401A, a middle cylindrical portion 403A extending cylindrically from the inner periphery of the outer annular portion 401A to the side opposite to the outer cylindrical portion 402A in the axial direction, an inner annular portion 404A extending radially inward from the end of the middle cylindrical portion 403A on the side opposite to the outer annular portion 401A, and an inner cylindrical portion 405A extending from the inner periphery of the inner annular portion 404A to the outer cylindrical portion 402A side in the axial direction.

[0054] Next, the comb teeth are formed at the free end of the bottomed cylindrical member 40A by cutting (step S120). Then, the bottomed cylindrical member 40A is punched or cut to remove unnecessary portions from the outer annular portion 401A and the middle cylindrical portion 403A of the bottomed cylindrical member 40A (step S121). Figure 6 The first connecting member 42 and the second connecting member 43 are formed by joining the outer tube portion 402A and the outer peripheral portion of the outer annular portion 401A of the bottomed cylindrical member 40A to form the cylindrical portion 421 and the flange portion 422 of the first connecting member 42, and the inner annular portion 404A, the middle cylindrical portion 403A and the inner cylindrical portion 405A of the bottomed cylindrical member 40A to form the annular portion 431, the outer cylindrical portion 432 and the inner cylindrical portion 433 of the second connecting member 43.

[0055] Then, if Figure 6 As shown in (B) in the figure, the first connecting member 42 and the second connecting member 43 are fixed to the parking gear 41 by welding (process S140), and the manufacture of the drum portion 40 is completed. Process S130 is performed as follows. In a state where the flange portion 422 of the first connecting member 42 is axially abutted against the first step portion 415 of the parking gear 41, the inner peripheral surface of the flange portion 422 of the first connecting member 42 is fixed to the outer peripheral surface of the annular portion 412 of the parking gear 41 by welding. In addition, in a state where the outer peripheral surface of the free end of the outer cylinder portion 432 of the second connecting member 43 is aligned with the inner peripheral surface of the flange portion 413 of the parking gear 41B in the axial direction, the outer peripheral surface of the free end of the outer cylinder portion 432 is fixed to the inner peripheral surface of the flange portion 413 by welding.

[0056] In the embodiment, the outer diameter of the outer cylinder portion 432 of the second connecting member 43 is smaller than the inner diameter of the flange portion 422 of the first connecting member 42, and the first connecting member 42 and the second connecting member 43 are formed by removing unnecessary portions after forming the bottomed cylindrical member 40A, and the first connecting member 42 and the second connecting member 43 can be formed by so-called double-cutting press working. As a result, compared with the case where the first connecting member 42 and the second connecting member 43 are formed separately by press working, the base material can be effectively used, and the time required for forming the first connecting member 42 and the second connecting member 43 can be further shortened.

[0057] Moreover, with the flange portion 422 of the first connecting component 42 being axially abutted against the first step portion 415 of the parking gear 41, the inner circumferential surface of the flange portion 422 of the first connecting component 42 is fixed to the outer circumferential surface of the annular portion 412B of the parking gear 41 by welding, thereby easily performing axial positioning and welding of the first connecting component 42B and the parking gear 41B.

[0058] In the embodiment, the first connecting member 42 is formed separately from the ring gear 37 and the parking gear 41, and the parking gear 41 is formed separately from the second connecting member 43, but at least the parking gear 41 and the second connecting member 43 only need to be formed separately, and the first connecting member 42 and the ring gear 37 may be formed integrally.

[0059] In the embodiment, the drum 40 connects the ring gear 37 of the second planetary gear mechanism 35 to the output member 27 , but depending on the form of the automatic transmission 25 , a carrier of the planetary gear mechanism or the like may be connected to the output member.

[0060] In an embodiment, the spline 37a formed on the outer circumferential surface of the ring gear 37 of the second planetary gear mechanism 35 is engaged with the comb tooth portion 423 formed on the axial end of the first connecting member 42 of the drum portion 40, but the spline 37a formed on the outer circumferential surface of the ring gear 37 can also be engaged with the spline formed on the inner circumferential surface of the first connecting member 42.

[0061] In the embodiment, a gap is formed between the end surface of the first connecting member 42 side in the axial direction of the ring gear 37 and two adjacent teeth of the comb tooth portion 423 to connect the inside and outside of the drum portion 40 in the radial direction, but such a gap may not be formed. In this case, an oil hole may be formed in the first connecting member 42 to connect the inside and outside of the drum portion 40 in the radial direction.

[0062] In the embodiment, the parking gear 41 and the first connecting member 42 are joined by welding, and the parking gear 41 and the second connecting member 43 are joined by welding, but as long as the parking gear 41 and the second connecting member 43 are joined, the parking gear 41 and the first connecting member 42 can also be connected by spline fitting or the like.

[0063] In the embodiment, the first connecting member 42 and the second connecting member 43 are formed by a so-called double-cutting stamping process, but they may be formed separately by stamping processes. In this case, the outer diameter of the outer cylinder portion 432 may be substantially equal to or greater than the inner diameter of the flange portion 422 of the first connecting member 42. In addition, the first connecting member 42 may not be a stamped part, for example, it may be a forged part or a part formed by cutting.

[0064] In the embodiment, the second connection member 43 includes the annular portion 431 , the outer tube portion 432 , and the inner tube portion 433 , but the shape is not limited to this, and the second connection member 43 may not include the outer tube portion 432 and the inner tube portion 433 .

[0065] Figure 7 FIG. 4 is a partial cross-sectional view showing the periphery of a drum portion 40B according to another embodiment. Figure 7 In the embodiment, the output member 27 and the ring gear 37 of the second planetary gear mechanism 35 are connected to Figure 4 The drum portion 40B is the same as Figure 4 The drum portion 40 shown is the same and has a parking gear 41B of the parking device, a first connecting member 42B connected to the ring gear 37 and connected (fixed) to the parking gear 41B, and a second connecting member 43B connected (fixed) to the parking gear 41B and the output member 27.

[0066] The parking gear 41B is a forged part formed by, for example, forging, quenching, or cutting, and comprises: a cylindrical gear portion 411B having a plurality of external teeth; an annular ring portion 412B extending from one end portion ( Figure 7 and annular flange portions 413B, 414B, from the other axial end portion of the gear portion 411B ( Figure 7 The right end portion in the middle of the gear portion 411B) extends radially inward in two stages. Figure 7 The first step portion 415B is formed by the outer peripheral surface of the annular portion 412B and the inner peripheral surface of the flange portion 413B. The flange portion 414B is formed on the opposite side of the annular portion 412B relative to the flange portion 413B. In the parking gear 41B, the inner peripheral surface of the flange portion 413B and one end surface of the flange portion 414B in the axial direction ( Figure 7 A second step portion 416B is formed on the left end surface of the substrate.

[0067] The first connecting member 42B is a stamped product roughly formed by stamping, and has a cylindrical portion 421B and an axial end portion ( Figure 4 The flange portion 422B is an annular flange portion 422B extending radially inward from the right end portion in the center of the parking gear 41B. In the flange portion 422B, the inner peripheral surface of the flange portion 422B is fixed to the outer peripheral surface of the annular portion 412B of the parking gear 41B by welding, while the flange portion 422B and the first step portion 415B are in axial contact with each other (the axial end surface of the flange portion 422B and the axial end surface of the gear portion 411B of the parking gear 41B are in mutual contact). Therefore, the inner peripheral surface of the flange portion 422B and the outer peripheral surface of the annular portion 412B of the parking gear 41B are connected via a welded portion (a joint formed by welding).

[0068] A spline 423B is formed at the other end of the cylindrical portion 421B in the axial direction, and a recessed portion 424B recessed radially outward is formed on the inner circumferential surface of the spline 423B. In this embodiment, the spline 423B is formed by stamping. The ring gear 37 of the second planetary gear mechanism 35 and the first connecting member 42B are connected to each other by fitting the spline 37a formed on the outer circumferential surface of the ring gear 37 with the spline 423B of the first connecting member 42B, and a snap ring 50 is sandwiched between the annular recessed portion 37b of the spline 37a and the recessed portion 424B of the spline 423B.

[0069] The second connecting member 43B is a stamped product roughly formed by stamping, and has an annular ring portion 431B and a second planetary gear 35 side ( Figure 7 The outer diameter of the annular portion 431B is designed to be smaller than the inner diameter of the flange portion 422B of the first connecting member 42B. In the annular portion 431B, when the annular portion 431B and the second step portion 416B are in axial contact (the axial end surface of the annular portion 431B and the axial end surface of the flange portion 414B of the parking gear 41B are in contact with each other), the outer peripheral surface of the annular portion 431B is fixed to the inner peripheral surface of the flange portion 413B of the parking gear 41B by welding. The inner peripheral surface of the free end of the annular portion 433B is fixed to the outer peripheral surface of the flange portion 272 of the output member 27 by welding. Therefore, the outer circumferential surface of the annular portion 431B and the inner circumferential surface of the flange portion 413B of the parking gear 41B are connected via a weld portion, and the inner circumferential surface of the free end of the truncated cone portion 433B and the outer circumferential surface of the flange portion 272 of the output member 27 are connected via a weld portion.

[0070] In this embodiment, since the first connection member 42B of the drum 40B is formed separately from the ring gear 37 and the parking gear 41B of the second planetary gear mechanism 35, the first connection member 42B is formed as a stamped product by stamping, the spline 423B is formed by stamping at the free end of the cylindrical portion 421B (the predetermined fitting portion to be fitted with the ring gear 37), and the inner peripheral surface of the flange portion 422B (the predetermined welding portion to be welded with the annular portion 412B of the parking gear 41B) is cut as needed. As a result, compared with the case where the first connection member 42B is integrally formed with the ring gear 37 and the parking gear 41B by cutting (forming the whole thereof by cutting), the cutting part and the processing time can be reduced. As a result, the material cost and the processing cost can be reduced.

[0071] Furthermore, in the first connecting member 42B and the parking gear 41B, the inner circumferential surface of the flange portion 422B of the first connecting member 42B and the outer circumferential surface of the annular portion 412B of the parking gear 41B are fixed to each other by welding while the flange portion 422B of the first connecting member 42B and the first step portion 415B of the parking gear 41B are in contact with each other in the axial direction. Therefore, the first connecting member 42B and the parking gear 41B can be easily positioned and welded in the axial direction.

[0072] In addition, since the second connection member 43B of the drum portion 40B is formed separately from the parking gear 41B, it is sufficient to form the second connection member 43B as a stamped product by stamping, and to perform cutting on the outer peripheral surface of the annular portion 431B (the welding scheduled portion to be welded to the flange portion 413B of the parking gear 41B) and the inner peripheral surface of the free end of the truncated cone portion 433B (the welding scheduled portion to be welded to the flange portion 272 of the output member 27) as needed. As a result, compared with the case where the second connection member 43B and the parking gear 41B are integrally formed by cutting (formed as a whole by cutting), the cutting portion and the processing time can be reduced. As a result, the material cost and the processing cost can be reduced.

[0073] Furthermore, in the second connecting member 43B and the parking gear 41B, the outer peripheral surface of the annular portion 431B of the second connecting member 43B and the inner peripheral surface of the flange portion 413B of the parking gear 41B are fixed to each other by welding in a state where the annular portion 431B of the second connecting member 43B and the second step portion 416B of the parking gear 41B abut against each other in the axial direction. Therefore, the second connecting member 43B and the parking gear 41B can be easily positioned and welded in the axial direction.

[0074] The drum portion 40B is manufactured, for example, as follows. Figure 8 40B is a process diagram showing the manufacturing process of the drum portion 40B. Fig. 9 40B is an explanatory diagram showing the manufacturing process of the drum portion 40B. Fig. 9 right Figure 8 The manufacturing process of the drum portion 40B is described below.

[0075] First, if Fig. 9 As shown in (A) in FIG. 1 , the bottomed cylindrical member 40C including the first connecting member 42B and the second connecting member 43B is integrally formed by stamping (step S200), and the parking gear 41 is formed separately from the bottomed cylindrical member 40C by forging, quenching, and cutting (step S210). Fig. 9 As shown in (A), the bottomed cylindrical component 40C has an annular bottom 401C, a cylindrical portion 402C extending axially from the outer periphery of the bottom 401C in a cylindrical shape, and a conical portion 403C extending axially from the inner periphery of the annular bottom 401C in a conical shape on the same side as the cylindrical portion 402C.

[0076] Then, if Fig. 9 As shown in (B) in FIG. 1 , a spline 404C is formed at the free end of the cylindrical portion 402C of the bottomed cylindrical member 40C by stamping (step S220). Then, the bottomed cylindrical member 40C is subjected to a blanking process to remove an annular unnecessary portion ( Fig. 9 The shaded part in (B) of Fig. 9 As shown in (C) in FIG. 2 , the first connecting member 42B and the second connecting member 43B are formed (process S230). Through this process S230, the outer peripheral portion of the cylindrical portion 402C (including the spline 404C) and the bottom 401C of the bottomed cylindrical member 40C becomes the cylindrical portion 421B (including the spline 423B) and the flange portion 422B of the first connecting member 42B, and the inner peripheral portion of the bottom 401C and the truncated cone portion 403C of the bottomed cylindrical member 40C become the annular portion 431B and the truncated cone portion 433B of the second connecting member 43B. The bottomed cylindrical member 40C has a bottom 401C, and the first connecting member 42B and the second connecting member 43B are formed by removing the unnecessary annular portion from the bottom 401C, so that the punching process can be easily performed.

[0077] Then, if Fig. 9As shown in (D) in FIG. 2 , the first connecting member 42B and the second connecting member 43B are fixed to the parking gear 41B by welding (process S240), thereby completing the manufacture of the drum portion 40. Process S240 is performed as follows. In a state where the flange portion 422B of the first connecting member 42B is in contact with the first step portion 415B of the parking gear 41B in the axial direction, the inner circumferential surface of the flange portion 422B of the first connecting member 42B is fixed to the outer circumferential surface of the annular portion 412B of the parking gear 41B by welding. In addition, in a state where the annular portion 431B of the second connecting member 43B is in contact with the second step portion 416B of the parking gear 41B in the axial direction, the outer circumferential surface of the annular portion 431B of the second connecting member 43B is fixed to the inner circumferential surface of the flange portion 413B of the parking gear 41B by welding.

[0078] In this embodiment, based on the fact that the outer diameter of the annular portion 431B of the second connecting member 43B is smaller than the inner diameter of the flange portion 422B of the first connecting member 42B, the first connecting member 42B and the second connecting member 43B are formed by removing unnecessary parts after forming the bottomed cylindrical member 40C, and the first connecting member 42B and the second connecting member 43B can be formed by a so-called double-cutting stamping process. As a result, compared with the case where the first connecting member 42B and the second connecting member 43B are formed by stamping, the base material can be effectively utilized, and the time required for forming the first connecting member 42B and the second connecting member 43B can be further shortened. In addition, since the spline 423B of the first connecting member 42B is formed by stamping, it can be easily processed compared with the case where the comb teeth portion 423 of the first connecting member 42 is formed by cutting.

[0079] Furthermore, the inner circumferential surface of the flange portion 422B of the first connecting member 42B is fixed to the outer circumferential surface of the annular portion 412B of the parking gear 41B by welding while the flange portion 422B of the first connecting member 42B is in contact with the first step portion 415B of the parking gear 41B in the axial direction, so that the first connecting member 42B and the parking gear 41B can be easily positioned and welded. Similarly, the outer circumferential surface of the annular portion 431B of the second connecting member 43B is fixed to the inner circumferential surface of the flange portion 413B of the parking gear 41B by welding while the annular portion 431B of the second connecting member 43B is in contact with the second step portion 416B of the parking gear 41B in the axial direction, so that the second connecting member 43B and the parking gear 41B can be easily positioned and welded.

[0080] In this embodiment, the first connecting member 42B is formed separately from the ring gear 37 and the parking gear 41B, and the parking gear 41B is formed separately from the second connecting member 43B. However, as long as at least the parking gear 41B and the second connecting member 43B are formed separately, the first connecting member 42B and the ring gear 37 may be formed integrally.

[0081] In this embodiment, the drum portion 40B connects the ring gear 37 of the second planetary gear mechanism 35 to the output member 27 , but depending on the form of the automatic transmission 25 , a carrier of the planetary gear mechanism or the like may be connected to the output member.

[0082] In this embodiment, the parking gear 41B and the first connecting member 42B are joined by welding, and the parking gear 41B and the second connecting member 43B are joined by welding, but as long as the parking gear 41B and the second connecting member 43B are joined, the parking gear 41B and the first connecting member 42B can also be connected by spline fitting or the like.

[0083] In this embodiment, the first connecting member 42B and the second connecting member 43B are formed by so-called double-cutting stamping, but they may be formed separately by stamping. In this case, the outer diameter of the annular portion 431B may be substantially equal to or larger than the inner diameter of the flange portion 422B of the first connecting member 42B. In addition, the first connecting member 42B may not be a stamped part, for example, it may be a forged part or a part formed by cutting.

[0084] As described above, a method for manufacturing a drum portion of a power transmission device of the present invention, wherein the power transmission device has a transmission (25) that changes the speed of power input to an input member (26) and transmits the power to an output member (27), wherein the transmission (25) has a drum portion (40, 40B) with a bottom, wherein the drum portion (40, 40B) is connected to an intermediate member (37) in a power transmission path from the input member (26) to the output member (27) and the output member (27), and wherein the drum portion (40, 40B) has a parking gear (41, 41B) of a parking device, and is connected to the intermediate member (37) and the parking gear (41, 41B). A first connecting member (42, 42B), and a second connecting member (43, 43B) connected to the parking gear (41, 41B) and the output member (27) via a joint, wherein the manufacturing method of the drum portion of the power transmission device comprises: step (a), forming the first connecting member (42, 42B), and forming the second connecting member (43, 43B) by stamping, and forming the parking gear (41, 41B); and step (b), engaging the parking gear (41, 41B) with the second connecting member (43, 43B), and connecting the parking gear (41, 41B) with the first connecting member (42, 42B).

[0085] In the manufacturing method of the drum portion of the power transmission device of the present invention, a first connecting member is formed, and a second connecting member is formed by stamping, and a parking gear is formed, the parking gear is engaged with the second connecting member, and the parking gear is connected to the first connecting member. As a result, the second connecting member and the parking gear can be formed separately by stamping (cutting can be performed on the predetermined engagement portion of the second connecting member that engages with the parking gear or the output member as required). Therefore, compared with the case where the second connecting member and the parking gear are integrally formed by cutting, the cutting portion and processing time when forming the second connecting member can be reduced, and further the cutting portion and processing time when forming the drum portion can be reduced. As a result, the material cost and processing cost when forming the drum portion can be reduced.

[0086] In the method for manufacturing a drum portion of a power transmission device of the present invention, the first connecting member (42, 42B) may be connected to the parking gear (41, 41B) via a joint, the inner diameter of the first connecting member (42, 42B) may be larger than the outer diameter of the second connecting member (43, 43B), and the step (a) may include: a step (a1) of integrally forming the bottomed cylindrical member (41) including the portion to be the first connecting member (42, 42B) and the portion to be the second connecting member (43, 43B) by press working; 0A, 40C); and step (a2), removing unnecessary parts from the bottomed cylindrical member (40A, 40C) between the first connecting member (42, 42B) and the second connecting member (43, 43B) to form the first connecting member (42, 42B) and the second connecting member (43, 43B), and in the step (b), the first connecting member (42, 42B) and the second connecting member (43, 43B) are engaged with the parking gear (41, 41B). In this way, the first connecting member and the second connecting member can be formed by a so-called double-cutting stamping process.

[0087] In this case, the bottomed cylindrical member (40C) may include an annular bottom (401C) and a cylindrical portion (402C) extending axially from the outer periphery of the bottom (401C), and in the step (a2), the first connecting member (42B) and the second connecting member (43B) may be formed by removing the annular unnecessary portion from the bottom (401C) of the bottomed cylindrical member (40C) by punching. The bottomed cylindrical member has a bottom, and the first connecting member and the second connecting member are formed by removing the annular unnecessary portion from the bottom, thereby making it easy to perform punching.

[0088] In this case, the intermediate member (37) may be a ring gear (37) of a planetary gear mechanism (35), a spline (37a) may be formed on the outer peripheral surface of the ring gear (37), and the step (a) may further include a step (a3) ​​after the step (a1), in which a spline (423B) is formed by press working at a connection portion of the first connecting member (42B) connected to the ring gear (37). In this way, compared with a case where a spline is formed at a connection portion of the first connecting member connected to the ring gear by cutting or the like, processing can be performed more easily.

[0089] In the manufacturing method of the drum portion of the power transmission device of the present invention, in the step (b), one axial end portion of the first connecting member (42, 42B) can also be connected to the parking gear (41, 41B), and the outer peripheral portion of the second connecting member (43, 43B) can be joined to the inner peripheral portion of the parking gear (41, 41B).

[0090] In the manufacturing method of the drum portion of the power transmission device of the present invention, the first connecting member (42, 42B) may be connected to the parking gear (41, 41B) via a joint, and the end of the parking gear (41, 41B) on the side of the first connecting member (42, 42B) in the axial direction may have a first step portion (415, 415B), and in the step (b), the first connecting member (42, 42B) is joined to the parking gear (41, 41B) in a state where one end of the first connecting member (42, 42B) in the axial direction abuts against the first step portion (415, 415B) of the parking gear (41, 41B) in the axial direction. In this way, the first connecting member and the parking gear can be easily positioned and joined in the axial direction.

[0091] In the method for manufacturing a drum portion of a power transmission device of the present invention, the parking gear (41B) may have a second step portion (416B) on its inner circumference, and in the step (b), the second connecting member (43B) is engaged with the parking gear (41B) in a state where the outer circumference of the second connecting member (43B) is in contact with the second step portion (416B) of the parking gear (41B) in the axial direction. In this way, the second connecting member and the parking gear can be easily positioned and engaged in the axial direction.

[0092] In the manufacturing method of the drum portion of the power transmission device of the present invention, the joint portion may be a welded portion. In addition, in the step (a), the parking gear (41, 41B) may be formed by forging. In this case, in the step (a), the parking gear may be formed by forging, quenching, or cutting. Furthermore, the intermediate component (37) may be a ring gear (37) of a planetary gear mechanism (35).

[0093] The power transmission device (20) of the present invention has a transmission (25) which changes the speed of power input to an input member (26) and transmits it to an output member (27), wherein the transmission (25) has a drum portion (40, 40B) with a bottom, the drum portion (40, 40B) is connected to an intermediate member (37) in a power transmission path from the input member (27) to the output member (28) and the output member (27), and the drum portion (40, 40B) has a parking gear (41, 41B) of a parking device, a first connecting member (42, 42B) connected to the intermediate member (37) and the parking gear (41, 41B), and a second connecting member (43, 43B) as a stamped part connected to the parking gear (41, 41B) and the output member (27) via a joint.

[0094] In the power transmission device of the present invention, the transmission has a drum portion with a bottom cylinder, which is connected to the intermediate component and the output component in the power transmission path from the input component to the output component, and the drum portion has a parking gear of the parking device, a first connecting component connected to the intermediate component and the parking gear, and a second connecting component as a stamping workpiece connected to the parking gear and the output component via a joint. Thus, the second connecting component and the parking gear can be formed separately by stamping (cutting can be performed on the predetermined joint portion of the second connecting component that is engaged with the parking gear or the output component as required). Therefore, compared with the case where the second connecting component and the parking gear are integrally formed by cutting, the cutting part and processing time when forming the second connecting component can be reduced, and further the cutting part and processing time when forming the drum can be reduced. As a result, the material cost and processing cost when forming the drum can be reduced. Here, the joint can also be a welding part.

[0095] In the power transmission device of the present invention, the first connecting member (42, 42B) may be connected to the parking gear (41, 41B) via a joint and may be a stamped part, and the inner diameter of the first connecting member (42, 42B) may be larger than the outer diameter of the second connecting member (43, 43B). In this way, the first connecting member and the second connecting member may be formed by a so-called double-cut stamping process.

[0096] In the power transmission device of the present invention, the parking gear may be a forged part. In this case, the parking gear may be formed by forging, quenching, or cutting.

[0097] In the power transmission device of the present invention, it may also be that one axial end portion of the first connecting member (42, 42B) is connected to the parking gear (41, 41B), the other axial end portion of the first connecting member (42, 42B) is connected to the intermediate member (37), the outer peripheral portion of the second connecting member (43, 43B) is connected to the inner peripheral portion of the parking gear (41, 41B) via the joint, and the inner peripheral portion of the second connecting member (43, 43B) is connected to the outer peripheral portion of the output member (28) via the joint.

[0098] In the power transmission device of the present invention, it may also be that the first connecting member (42, 42B) is connected to the parking gear (41, 41B) via a joint, and the end of the parking gear (41, 41B) on the side of the first connecting member (42, 42B) in the axial direction has a first step portion (415, 415B), and one end of the first connecting member (42, 42B) in the axial direction is connected to the parking gear (41, 41B) via the joint in a state of abutting the first step portion (415, 415B) of the parking gear (41, 41B) in the axial direction.

[0099] In the power transmission device of the present invention, the parking gear (41B) may have a second step portion (416B) on the inner periphery, and the outer periphery of the second connecting member (43B) is connected to the parking gear (41B) via the coupling portion in a state of abutting the second step portion (416B) of the parking gear (41B) in the axial direction.

[0100] In the power transmission device of the present invention, the intermediate component (37) may also be the ring gear (37) of the planetary gear mechanism (35). In this way, the first connecting component and the parking gear and the ring gear can be formed separately by stamping (if necessary, the predetermined engagement portion of the first connecting component that engages with the parking gear and the ring gear can be cut). Therefore, compared with the case where the first connecting component and the ring gear are integrally formed by cutting, the cutting portion and processing time when forming the first connecting component can be reduced, and the cutting portion and processing time when forming the drum portion can be further reduced.

[0101] In the power transmission device of the present invention, the intermediate member (37) may be a ring gear (37) of a planetary gear mechanism (35), a spline (37a) is formed on the outer peripheral surface of the ring gear (37), a comb tooth portion (423) in a comb tooth shape that engages with the spline (37a) is formed at the end of the first connecting member (42) on the ring gear side, and a gap that connects the inside and outside of the drum (40) is formed between the end surface of the ring gear (37) on the first connecting member (42) side and two adjacent teeth of the comb tooth portion (423). In this way, the gap can function as an oil hole for passing working oil. As a result, the manufacturing process can be reduced compared to the case where an oil hole is provided separately.

[0102] In the power transmission device of the present invention, the intermediate component (37) may be a ring gear (37) of a planetary gear mechanism (35), a gear side spline (37a) is formed on the outer peripheral surface of the ring gear (37), and a component side spline (423B) engaged with the gear side spline (37a) is formed at the end of the first connecting component (42B) on the side of the ring gear (37).

[0103] Although the modes for carrying out the present invention have been described above, the present invention is not limited to such embodiments, and can be carried out in various forms without departing from the gist of the present invention.

[0104] Industrial Applicability

[0105] The present invention can be used in the power transmission device manufacturing industry and the like.

Claims

1. A method for manufacturing a drum portion of a power transmission device, The power transmission device includes a transmission that changes the speed of power input to an input member and transmits the power to an output member. The transmission has a bottomed cylindrical drum portion, the drum portion being connected to an intermediate member in a power transmission path from the input member to the output member and the output member. The drum portion includes a parking gear of a parking device, a first connecting member connected to the intermediate member and the parking gear, and a second connecting member connected to the parking gear and the output member via a joint, wherein: The method for manufacturing the drum portion of the power transmission device comprises: Step (a), forming the first connecting member, forming the second connecting member by press working, and forming the parking gear; and step (b), engaging the parking gear with the second connecting member and connecting the parking gear with the first connecting member, The first connecting member is connected to the parking gear via a joint. The inner diameter of the first connecting member is larger than the outer diameter of the second connecting member, The intermediate component is the ring gear of the planetary gear mechanism, A spline is formed on the outer peripheral surface of the gear ring. A comb-teeth portion having a comb-teeth shape and engaged with the spline is formed at an end portion of the first connecting member on the ring gear side. A gap that allows the inside and outside of the drum portion to communicate is formed between an end surface of the ring gear on the first coupling member side and two adjacent teeth of the comb-tooth portion.

2. The method for manufacturing a drum portion of a power transmission device according to claim 1, wherein: The step (a) comprises: Step (a1), forming a bottomed cylindrical member including portions to be the first connecting member and the second connecting member integrally by press working; and Step (a2), removing unnecessary portions from the bottomed cylindrical member between the first connecting member and the second connecting member to form the first connecting member and the second connecting member, In the step (b), the first connecting member and the second connecting member are engaged with the parking gear.

3. The method for manufacturing a drum portion of a power transmission device according to claim 2, wherein: The bottomed cylindrical component has an annular bottom and a cylindrical portion extending in the axial direction from the outer periphery of the bottom. In the step (a2), the first connecting member and the second connecting member are formed by removing the unnecessary annular portion from the bottom portion of the bottomed cylindrical member by punching.

4. The method for manufacturing a drum portion of a power transmission device according to any one of claims 1 to 3, wherein: In the step (b), one axial end portion of the first connecting member is connected to the parking gear, and an outer peripheral portion of the second connecting member is joined to an inner peripheral portion of the parking gear.

5. The method for manufacturing a drum portion of a power transmission device according to any one of claims 1 to 3, wherein: The first connecting member is connected to the parking gear via a joint. The parking gear has a first step portion at an end portion on the first connecting member side in the axial direction. In the step (b), the first connecting member is coupled to the parking gear in a state where one end portion of the first connecting member in the axial direction is in contact with the first step portion of the parking gear in the axial direction.

6. The method for manufacturing a drum portion of a power transmission device according to any one of claims 1 to 3, wherein: The parking gear has a second step portion on the inner periphery. In the step (b), the second connecting member is engaged with the parking gear in a state where the outer peripheral portion of the second connecting member is in contact with the second step portion of the parking gear in the axial direction.

7. A power transmission device, comprising a transmission, the transmission changing the speed of power input to an input member and transmitting the power to an output member, wherein: The transmission has a bottomed cylindrical drum portion, the drum portion being connected to an intermediate member in a power transmission path from the input member to the output member and the output member. The drum portion includes a parking gear of a parking device, a first connecting member connected to the intermediate member and the parking gear, and a second connecting member as a press-formed part connected to the parking gear and the output member via a joint, respectively. The first connecting member is connected to the parking gear via a joint and is a stamped part. The inner diameter of the first connecting member is larger than the outer diameter of the second connecting member, The intermediate component is the ring gear of the planetary gear mechanism, A spline is formed on the outer peripheral surface of the gear ring. A comb-teeth portion having a comb-teeth shape and engaged with the spline is formed at an end portion of the first connecting member on the ring gear side. A gap that allows the inside and outside of the drum portion to communicate is formed between an end surface of the ring gear on the first coupling member side and two adjacent teeth of the comb-tooth portion.

8. The power transmission device according to claim 7, wherein: One axial end of the first connecting member is connected to the parking gear. The other end portion of the first connecting member in the axial direction is connected to the intermediate member. The outer peripheral portion of the second connection member is connected to the inner peripheral portion of the parking gear via the joint portion. The inner peripheral portion of the second connection member is connected to the outer peripheral portion of the output member via the joint portion.

9. The power transmission device according to claim 7, wherein: The first connecting member is connected to the parking gear via a joint. The parking gear has a first step portion at an end portion on the first connecting member side in the axial direction. One end portion of the first connection member in the axial direction is connected to the parking gear via the engagement portion in a state in which the end portion abuts against the first step portion of the parking gear in the axial direction.

10. The power transmission device according to claim 8, wherein: The first connecting member is connected to the parking gear via a joint. The parking gear has a first step portion at an end portion on the first connecting member side in the axial direction. One end portion of the first connection member in the axial direction is connected to the parking gear via the engagement portion in a state in which the end portion abuts against the first step portion of the parking gear in the axial direction.

11. The power transmission device according to any one of claims 7 to 10, wherein: The parking gear has a second step portion on the inner periphery. The outer peripheral portion of the second connection member is connected to the parking gear via the engagement portion in a state in which the outer peripheral portion of the second connection member is in contact with the second step portion of the parking gear in the axial direction.

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