power transmission device

Abstract

To provide a power transmission device which enables a harness to be arranged easily in a housing case which houses a power transmission mechanism.SOLUTION: A power transmission device 10 includes: a housing case 200 which houses a power transmission mechanism; and a harness 230 arranged inside the housing case 200. The housing case 200 includes: a first case part 210; and a second case part 212 connected to the first case part 210 and has a cylindrical part 220 which is formed in a cylindrical shape so as to connect a first opening 222, which is open to the first case part 210 side in a connection direction X of the first case part 210 and the second case part 212, with a second opening 224, which is open to the opposite side of the first opening 222 in the connection direction X. The harness 230 is arranged in the connection direction X through the cylindrical part 220.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a power transmission device. [Background technology]

[0002] Conventionally, there have been provided power transmission devices that house a power transmission mechanism such as a CVT inside a housing case, such as the power transmission device disclosed in Patent Document 1. The power transmission device of Patent Document 1 is configured such that a first section constituting the housing case covers the front portion of the CVT or other speed change mechanism, and a second section connected to the first section covers the rear portion of the speed change mechanism. The power transmission device of Patent Document 1 is also configured such that a transfer is disposed in a third section of the housing case that is subsequent to the second section. The power transmission device of Patent Document 1 is also configured such that a clutch is provided behind the second section to selectively disconnect or connect the power transmission path to the transfer. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-79924 Summary of the Invention [Problem to be solved by the invention]

[0004] In the power transmission device of the prior art described above, the harness connected to the clutch actuation device must be inserted from a first hole provided near the boundary between the first section and the second section inside the housing case toward a second hole provided in the second section and reach the rear side of the second section. However, in the power transmission device of the prior art, when the first section and the second section of the housing case are connected and assembled, the second hole cannot be visually confirmed when routing the harness from the first hole to the second hole. Therefore, the power transmission device of the prior art has a problem in that the harness routing is difficult and requires skill.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a power transmission device that is configured so that a harness can be easily routed inside a housing case that houses a power transmission mechanism. [Means for solving the problem]

[0006] (1) The power transmission device of the present invention transmits power input from a driving force source in a vehicle, and comprises a storage case that houses a power transmission mechanism, and a harness routed inside the storage case, wherein the storage case includes a first case portion and a second case portion connected to the first case portion, and has a cylindrical portion formed in a cylindrical shape to connect a first opening that opens toward the first case portion in the connection direction of the first case portion and the second case portion, and a second opening that opens on the opposite side of the first opening in the connection direction, and wherein the harness is routed through the cylindrical portion in the connection direction.

[0007] The power transmission device of the present invention has a cylindrical portion connecting a first opening that opens toward the first case portion in the connecting direction of the first and second case portions that form a housing case that houses a power transmission mechanism, and a second opening that opens on the opposite side of the first opening in the connecting direction. Therefore, the power transmission device of the present invention allows the harness to be routed from the first opening to the second opening by inserting the harness into the cylindrical portion through the first opening and pushing the harness along the cylindrical portion, or by pushing the harness in the opposite direction. In this way, the power transmission device of the present invention allows the harness to be routed using the cylindrical portion as a guide. Therefore, the power transmission device of the present invention allows the harness to be easily routed inside the housing case that houses the power transmission mechanism, regardless of the worker's level of skill.

[0008] (2) The power transmission device of the present invention described above may be characterized in that the first case portion has an oil pan, and the cylindrical portion is capable of forming an oil return path that returns oil from the second case portion to the oil pan provided in the first case portion.

[0009] In the power transmission device of the present invention, the cylindrical portion provided in the accommodating case can be utilized not only as a wiring path for the harness but also as an oil return path for returning oil from the second case portion to the oil pan provided in the first case portion. This allows the power transmission device of the present invention to simplify its configuration without requiring a separate component for configuring the oil return path. Furthermore, by providing the power transmission device of the present invention with an oil return path, oil retention in the second case portion can be suppressed and oil can be smoothly returned to the oil pan on the first case portion side. This reduces the amount of oil required in the power transmission device and suppresses air suction in the strainer.

[0010] (3) The power transmission device of the present invention described above may be characterized in that part or all of the tubular portion is formed so as to have a downward slope from the second opening side toward the first opening side.

[0011] The power transmission device of the present invention, with the above-described configuration, can smoothly discharge oil or the like that has entered the inside of the cylindrical portion to the first opening side. In particular, when the cylindrical portion is used as an oil return path that returns oil from the second case portion to the first case portion as described above, oil retention inside the cylindrical portion can be suppressed, and the oil can be smoothly returned to the first case portion side.

[0012] (4) The power transmission device of the present invention described above may be characterized in that the opening area of ​​the first opening is larger than the opening area of ​​the second opening.

[0013] The power transmission device of the present invention has the above-described configuration, which makes it easier to insert the harness into the tubular portion from the first opening side, and also makes it possible to accurately determine the position at which the harness is taken out of the tubular portion at the second opening side.

[0014] (5) The power transmission device of the present invention described above may be characterized in that part or all of the tubular portion is formed so that the cross-sectional area decreases from the first opening side toward the second opening side.

[0015] The power transmission device of the present invention has the above-described configuration, whereby the harness inserted into the tubular portion from the first opening can be smoothly guided to a position at the second opening as it moves toward the second opening, thereby further improving the ease of routing the harness from the first opening to the second opening.

[0016] (6) The power transmission device of the present invention described above may be characterized in that an equipment to which lubricating oil is supplied is housed inside the second case portion, the oil used to lubricate the equipment falls from the equipment side to the bottom side of the second case portion, and the second opening opens to the equipment on the bottom side of the second case portion.

[0017] The power transmission device of the present invention has the above-described configuration, so that oil that has been used to lubricate the equipment inside the second case portion and then dropped to the bottom of the second case portion can be smoothly taken in by the cylindrical portion. As a result, the power transmission device of the present invention can effectively use the cylindrical portion of the storage case as a path for smoothly returning oil from the second case portion to the first case portion.

[0018] (7) The power transmission device of the present invention described above may be characterized in that the first case portion houses a transmission to which the power output from the driving force source is input, the second case portion houses a clutch to which the power output from the transmission is input, and a clutch actuation device for actuating the clutch, and the harness is connected to the clutch actuation device.

[0019] By adopting the above-described configuration, the power transmission device of the present invention can easily route the harness inside the storage case even when the transmission is assembled in the first case portion and the clutch and clutch actuation device are assembled in the second case portion.

[0020] (8) The power transmission device of the present invention described above may be characterized in that the housing case further includes a third case portion connected to the second case portion on the opposite side to the first case portion, the first case portion housing a transmission to which power output from the driving force source is input, the third case portion housing a transfer, and the second case portion housing a clutch that selectively disconnects or connects the power transmission path between the transmission and the transfer, and an operating device for operating the clutch.

[0021] As described above, the power transmission device of the present invention allows the harness to be easily routed inside the storage case, even if the transfer is housed in the third case section connected to the opposite side of the second case section from the first case section. [Effects of the Invention]

[0022] According to the present invention, it is possible to provide a power transmission device configured so that a harness can be easily routed inside a housing case that houses a power transmission mechanism. [Brief explanation of the drawings]

[0023] [Figure 1]1 is an explanatory diagram showing a vehicle equipped with a power transmission device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a bottom view showing a state in which an oil pan is removed in the power transmission device according to the embodiment of the present invention. [Figure 3] 1 is a side view showing a power transmission device according to an embodiment of the present invention, viewed from the rear side of the vehicle, with a third case portion removed. FIG. [Figure 4] 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 5] 10 is an enlarged perspective view showing a cylindrical portion included in a power transmission device according to one embodiment of the present invention, viewed from a second opening side. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] A power transmission device 10 according to one embodiment of the present invention will be described below with reference to the drawings, taking as an example a four-wheel drive vehicle (vehicle V) that employs the power transmission device 10. In the following description, before describing the characteristic configuration of the power transmission device 10, a general configuration of the vehicle V will be described.

[0025] <<General Configuration of Vehicle V Equipped with Power Transmission Device 10>> Fig. 1 is a diagram illustrating a schematic configuration of a vehicle V to which the present invention is applied. As shown in Fig. 1, the vehicle V includes a power transmission device 10, a driving force source 12, a pair of left and right front wheels 14L, 14R, a pair of left and right rear wheels 16L, 16R, and a control device 100. The vehicle V is a four-wheel drive vehicle that can be switched as needed between a two-wheel drive state in which driving force is transmitted to the rear wheels 16L, 16R and the four-wheel drive state in which driving force is transmitted to the front wheels 14L, 14R in addition to the rear wheels 16L, 16R and the vehicle V runs.

[0026] The driving force source 12 generates driving force for the vehicle V. The driving force source 12 can be constituted by, for example, an engine, a motor, etc. The front wheels 14L, 14R constitute auxiliary driving wheels of the vehicle V. The front wheels 14L, 14R function as driving wheels in four-wheel drive mode and as driven wheels in two-wheel drive mode. The rear wheels 16L, 16R constitute main driving wheels of the vehicle V. The rear wheels 16L, 16R function as driving wheels in both four-wheel drive mode and two-wheel drive mode.

[0027] The power transmission device 10 is a device for transmitting power input from a driving power source 12 in a vehicle V. As shown in Fig. 1, the power transmission device 10 includes a power transmission mechanism 18. The power transmission device 10 also includes a transmission 20 and a transfer 22 as the power transmission mechanism 18.

[0028] The power transmission 10 is capable of transmitting power to a front wheel differential gear 28, a rear wheel differential gear 30, a pair of left and right front axles 32L, 32R, and a pair of left and right rear axles 34L, 34R via a front propeller shaft 24 (power transmission member) and a rear propeller shaft 26. Specifically, the power transmission 10 can transmit power generated in the driving force source 12 to the rear wheels 16L, 16R via a power transmission path that runs from the transmission 20 to the rear wheels 16L, 16R via the transfer 22, the rear propeller shaft 26, the rear wheel differential gear 30, and the rear axles 34L, 34R in this order. The power transmission 10 can also configure a power transmission path that distributes and transmits a portion of the driving force transmitted from the driving force source 12 to the transfer 22 to the front wheels 14L, 14R. In other words, by adjusting the connection state of the front-wheel drive clutch 46, which will be described in detail later, the power transmission device 10 can transmit a portion of the power generated in the driving force source 12 to the front wheels 14L, 14R via a power transmission path that runs from the transmission 20 through the transfer 22, the front propeller shaft 24, the front-wheel differential gear device 28, the front wheel axles 32L, 32R, etc., in that order, to the front wheels 14L, 14R.

[0029] The transmission 20 operates by receiving output from the driving force source 12, and is configured by, for example, a conventionally known MT (manual transmission), AT (automatic transmission), CVT (continuously variable transmission), or the like.

[0030] The transfer 22 includes an input shaft 38, a rear-wheel-side output shaft 40, a front-wheel-drive drive sprocket 42, and a front-wheel-drive clutch 46 (first clutch) arranged around a first rotation axis C1. The transfer 22 also includes a front-wheel-side output shaft 48 and a front-wheel-drive driven sprocket 50 arranged around a second rotation axis C2 that extends in a direction along (substantially parallel to) the first rotation axis C1. The transfer 22 also includes a front-wheel-drive chain 52 wound around the front-wheel-drive drive sprocket 42 and the front-wheel-drive driven sprocket 50.

[0031] The input shaft 38 is connected to the transmission 20. This allows the input shaft 38 to receive power transmitted from the driving power source 12. The rear-wheel output shaft 40 is coupled to the rear propeller shaft 26 so as to be capable of transmitting power. A front-wheel drive drive sprocket 42 is supported on the rear-wheel output shaft 40 so as to be rotatable relative to the rear-wheel output shaft 40.

[0032] By engaging the front-wheel drive clutch 46, the front-wheel drive sprocket 42 can rotate integrally with the rear-wheel output shaft 40, and can transmit power to the front-wheel output shaft 48 via the front-wheel drive chain 52. Therefore, by engaging the front-wheel drive clutch 46, a portion of the driving force transmitted from the driving power source 12 to the rear propeller shaft 26 via the rear-wheel output shaft 40 can be distributed and transmitted to the front-wheel output shaft 48 via the front-wheel drive drive sprocket 42 and the front-wheel drive chain 52. On the other hand, by disengaging the front-wheel drive clutch 46, the driving force transmitted from the driving power source 12 to the rear-wheel output shaft 40 can be transmitted to the rear propeller shaft 26 without being transmitted (distributed) to the front-wheel drive drive sprocket 42.

[0033] The front-wheel drive clutch 46 is configured by a clutch such as a wet multi-plate clutch. The front-wheel drive clutch 46 is capable of adjusting the transmission torque transmitted from the rear-wheel output shaft 40 to the front-wheel drive drive sprocket 42 by adjusting the degree of engagement. In other words, the front-wheel drive clutch 46 functions as a clutch for selectively disconnecting or connecting the power transmission path between the driving power source 12 and the front propeller shaft 24, which functions as a power transmission member to the front wheels 14L, 14R.

[0034] The front-wheel-side output shaft 48 is connected to the front propeller shaft 24 so as to be able to transmit power. The front-wheel-drive driven sprocket 50 is provided so as to be able to rotate integrally with the front-wheel-side output shaft 48. In addition, a front-wheel-drive chain 52 is wound around the front-wheel-drive drive sprocket 42 and the front-wheel-drive driven sprocket 50, so that power can be transmitted between the two sprockets.

[0035] The front wheel differential gear device 28 includes a differential case 80, a pinion shaft 82, a pair of side gears 84L, 84R, a pair of pinions 86a, 86b, and a ring gear 90. The pinions 86a, 86b are attached to the differential case 80, with the pinions 86a, 86b disposed at both ends of the pinion shaft 82. The side gears 84L, 84R are disposed opposite each other within the differential case 80 and mesh with the pinions 86a, 86b, respectively. The side gears 84L, 84R are connected to the front wheels 14L, 14R via the front axles 32L, 32R. The ring gear 90 is attached integrally to the differential case 80. A front drive pinion 25 connected to the front propeller shaft 24 meshes with the ring gear 90. The front wheel differential gear device 28 also includes a mesh clutch 94 (second clutch). The mesh clutch 94 can be engaged by applying pressure (negative pressure). The mesh clutch 94 functions as a second clutch that selectively connects or disconnects the power transmission path between the front propeller shaft 24, which functions as a power transmission member to the front wheels 14L, 14R, and the front axles 32L, 32R, which are auxiliary drive wheels.

[0036] The rear wheel differential gear device 30 includes a differential case 120, a pinion shaft 122, a pair of side gears 124L and 124R, a pair of pinions 126a and 126b, and a ring gear 130. The pinions 126a and 126b are attached to the differential case 120, with the pinions 126a and 126b disposed at both ends of the pinion shaft 122. The side gears 124L and 124R are disposed opposite each other within the differential case 120 and mesh with the pinions 126a and 126b, respectively. The side gears 124L and 124R are connected to the rear wheels 16L and 16R via rear wheel axles 34L and 34R. The ring gear 130 is attached integrally to the differential case 120. A rear drive pinion 27 connected to the rear propeller shaft 26 meshes with the ring gear 130.

[0037] Because the vehicle V is configured as described above, when both the front-wheel drive clutch 46 and the dog clutch 94 are connected (engaged) to transmit torque, the vehicle V is in a state (four-wheel drive state) in which power generated in the driving force source 12 can be transmitted not only to the rear wheels 16L, 16R but also to the front wheels 14L, 14R. On the other hand, when either the front-wheel drive clutch 46 or the dog clutch 94 is disconnected (disengaged), the power transmission path to the front wheels 14L, 14R is cut off, and the vehicle V is in a state in which torque transmission is disabled. As a result, the vehicle V is in a state (two-wheel drive state) in which power generated in the driving force source 12 can be transmitted to the rear wheels 16L, 16R, but cannot be transmitted to the front wheels 14L, 14R.

[0038] The control device 100 is capable of controlling the connection state (engagement state) of the front-wheel drive clutch 46 and the dog clutch 94. The control device 100 is configured to include, for example, a microcomputer equipped with a CPU, RAM, ROM, an input / output interface, etc. The control device 100 is equipped with a first clutch control unit 102 (first clutch control unit) and a second clutch control unit 104.

[0039] The first clutch control unit 102 controls the transmission torque (degree of engagement of the first clutch) transmitted to the front propeller shaft 24 via the front-wheel drive clutch 46. The first clutch control unit 102 controls the degree of engagement based on the engagement pressure of the front-wheel drive clutch 46. As described above, in this embodiment, the front-wheel drive clutch 46 is a wet-type multi-plate clutch whose degree of engagement (engagement pressure) can be adjusted by controlling the magnitude of hydraulic pressure. Therefore, the first clutch control unit 102 can control the magnitude of the torque transmitted to the front propeller shaft 24 by controlling the magnitude of hydraulic pressure acting on the front-wheel drive clutch 46.

[0040] The second clutch control unit 104 controls the operation of the dog clutch 94 to control the transmission of torque from the front-wheel drive clutch 46 to the front-wheel differential gear unit 28. As described above, the dog clutch 94 can be engaged by applying pressure (negative pressure). Therefore, the second clutch control unit 104 can switch the dog clutch 94 between an engaged state and a disengaged state by controlling the magnitude of the pressure acting on the dog clutch 94.

[0041] <Characteristic Configuration of Power Transmission Device 10> Next, the characteristic configuration of the power transmission device 10 described above will be described in detail with reference to the drawings.

[0042] The power transmission device 10 transmits power input from a driving power source 12 in a vehicle V. As shown in Figures 1 and 2, the power transmission device 10 accommodates a transmission 20 and a transfer 22 that constitute a power transmission mechanism 18 inside a housing case 200. The housing case 200 is configured by connecting a first case portion 210, a second case portion 212, and a third case portion 214.

[0043] 1 and 2, the first case portion 210 is a portion that houses the transmission 20, to which power output from a driving power source is input. The first case portion 210 also includes an oil pan 210a (not shown in FIG. 2) and a strainer 210b at its bottom.

[0044] The second case portion 212 is connected to the first case portion 210. In this embodiment, the second case portion 212 is connected to the first case portion 210 at a position on the rear side of the vehicle V. The second case portion 212 accommodates therein devices that are operated by being supplied with lubricating oil. In this embodiment, the second case portion 212 accommodates the front-wheel drive clutch 46 (clutch) to which power output from the transmission 20 is input. The second case portion 212 also accommodates a solenoid valve 46a (clutch actuation device) for actuating the front-wheel drive clutch 46. In the second case portion 212, oil used to lubricate the front-wheel drive clutch 46 drops from the front-wheel drive clutch 46 side to the bottom side of the second case portion 212. A harness 230 arranged inside the accommodation case 200 is connected to the solenoid valve 46a.

[0045] The third case portion 214 is connected to the second case portion 212 on the opposite side to the first case portion 210. In this embodiment, the third case portion 214 is connected to the second case portion 212 at a position on the rear side of the vehicle V. The third case portion 214 houses the transfer 22.

[0046] The storage case 200 is formed by connecting the above-described first case portion 210, second case portion 212, and third case portion 214 in this order. A cylindrical portion 220 is provided inside the storage case 200 as shown in Fig. 4. The cylindrical portion 220 is formed in a cylindrical shape so as to connect a first opening 222 and a second opening 224 provided in the storage case 200. The cylindrical portion 220 is formed around the entire periphery of the first opening 222 and the second opening 224 (see Fig. 5).

[0047] The first opening 222 opens at a position on the first case portion 210 side in the coupling direction X between the first case portion 210 and the second case portion 212. The first opening 222 is formed to open at the boundary between the first case portion 210 and the second case portion 212. The first opening 222 can be provided, for example, at the end of the first case portion 210 on the second case portion 212 side, or at the end of the second case portion 212 on the first case portion 210 side. In the present embodiment, the first opening 222 is provided at the end of the first case portion 210 on the second case portion 212 side.

[0048] 3 and 4, the second opening 224 opens at a position opposite to the first opening 222 in the coupling direction X between the first case portion 210 and the second case portion 212. The second opening 224 opens at a position on the third case portion 214 side of the second case portion 212. Also, as shown in FIG. 3, the second opening 224 opens at a position on the bottom side of the second case portion 212, relative to the front-wheel drive clutch 46 provided in the second case portion 212.

[0049] 4, the cylindrical portion 220 is formed inside the second case portion 212 so as to extend in the coupling direction X between the first case portion 210 and the second case portion 212 (the front-rear direction of the vehicle V in this embodiment) so as to connect the first opening 222 and the second opening 224 described above. In the cylindrical portion 220, the opening area of ​​the first opening 222 is formed to be larger than the opening area of ​​the second opening 224. Furthermore, part or all (substantially the entirety in this embodiment) of the cylindrical portion 220 is formed to have a downward slope from the second opening 224 side toward the first opening 222 side.

[0050] A part or all of the cylindrical portion 220 is formed so that the cross-sectional area decreases from the first opening 222 side toward the second opening 224 side. In this embodiment, although there is a portion (expanded portion 226) in the middle portion in the extending direction of the cylindrical portion 220 where the cross-sectional area increases from the first opening 222 side toward the second opening 224 side, the cross-sectional area decreases from the first opening 222 side toward the second opening 224 side in a region closer to the first opening 222 than the expanded portion 226 and in a region closer to the second opening 224 than the expanded portion 226.

[0051] The cylindrical portion 220 constitutes a wiring path along which the harness 230, which is connected to the solenoid valve 46a for operating the front-wheel drive clutch 46, is routed. Because the cylindrical portion 220 has the shape described above, it functions as a guide for the harness 230 when the harness 230 is routed. Therefore, even if the second opening 224 cannot be seen from the first opening 222 side, for example, by connecting the first case portion 210 and the second case portion 212 and assembling devices such as the transmission 20, the front-wheel drive clutch 46, and the solenoid valve 46a, the harness 230 can be easily inserted from the first opening 222 side to reach the second opening 224.

[0052] Furthermore, the second opening 224 of the cylindrical portion 220 opens at a position on the bottom side of the second case portion 212 relative to the front-wheel drive clutch 46. Therefore, the cylindrical portion 220 functions as an oil return path for taking in, through the second opening 224, oil that drops down after lubricating the front-wheel drive clutch 46 in the second case portion 212, and returning the oil to the oil pan 210a provided in the first case portion 210. Furthermore, the cylindrical portion 220 is formed so as to have a downward slope from the second opening 224 side toward the first opening 222 side. Therefore, the cylindrical portion 220 can smoothly move the oil taken in through the second opening 224 from the second case portion 212 side toward the first case portion 210 side.

[0053] The power transmission device 10 of this embodiment has the characteristic configuration as described above, and therefore, the power transmission device 10 can achieve the following effects (a) to (h), for example.

[0054] (a) The power transmission device 10 of this embodiment has a tubular portion 220 that connects a first opening 222 that opens toward the first case portion 210 and a second case portion 212 that form a housing case 200 that houses the power transmission mechanism 18 in a connecting direction X of the first case portion 210 and the second case portion 212. The first opening 222 opens toward the first case portion 210, and a second opening 224 that opens on the opposite side of the first opening 222 in the connecting direction X. Therefore, in the power transmission device 10 of this embodiment, the harness 230 can be routed from the first opening 222 to the second opening 224 by inserting the harness 230 into the tubular portion 220 through the first opening 222 and pushing the harness 230 along the tubular portion 220, or by pushing the harness 230 in the opposite direction. In this way, the power transmission device 10 of this embodiment is configured so that the harness 230 can be routed using the tubular portion 220 as a guide. Therefore, in the power transmission device 10 of this embodiment, the harness 230 can be easily routed inside the accommodating case 200 that accommodates the power transmission mechanism 18, regardless of the skill level of the worker.

[0055] (b) In the power transmission device 10 of this embodiment, the first case portion 210 has an oil pan 210a, and the cylindrical portion 220 can form an oil return path that returns oil from the second case portion 212 to the oil pan 210a provided in the first case portion 210. Therefore, in the power transmission device 10, the cylindrical portion 220 provided in the accommodating case 200 can be used not only as a routing path for the harness 230 but also as an oil return path that returns oil from the second case portion 212 to the oil pan 210a provided in the first case portion 210. This eliminates the need for a separate component for forming the oil return path, thereby simplifying the device configuration. Furthermore, by providing the oil return path, the power transmission device 10 can prevent oil from accumulating in the second case portion 212 and smoothly return oil to the oil pan 210a on the first case portion 210 side. This makes it possible to reduce the amount of oil required in the power transmission device 10 and to prevent air from being sucked into the strainer.

[0056] (c) In the power transmission device 10 of this embodiment, part or all of the tubular portion 220 is formed to have a downward slope from the second opening 224 side toward the first opening 222 side. This allows the power transmission device 10 to smoothly discharge oil and the like that has entered the inside of the tubular portion 220 toward the first opening 222 side. As described above, when the tubular portion 220 is used as an oil return path that returns oil from the second case portion 212 toward the first case portion 210, oil is prevented from accumulating inside the tubular portion 220, and the oil can be smoothly returned to the first case portion 210 side.

[0057] (d) In the power transmission device 10 of this embodiment, the opening area of ​​the first opening 222 is larger than the opening area of ​​the second opening 224. This makes it easier to insert the harness 230 into the interior of the tubular portion 220 from the first opening 222 side of the power transmission device 10, and makes it possible to accurately determine the position where the harness 230 is taken out of the tubular portion 220 on the second opening 224 side.

[0058] (e) In the power transmission device 10 of this embodiment, part or all of the tubular portion 220 is formed so that the cross-sectional area decreases from the first opening 222 side toward the second opening 224 side, and therefore the harness 230 inserted into the tubular portion 220 from the first opening 222 side can be smoothly guided to a position provided in the second opening 224 as it moves toward the second opening 224. This allows the power transmission device 10 to further improve the ease of routing the harness 230 from the first opening 222 to the second opening 224.

[0059] (f) In the power transmission device 10 of this embodiment, the front-wheel drive clutch 46, which is a device to which lubricating oil is supplied, is accommodated inside the second case portion 212, and the oil used to lubricate the front-wheel drive clutch drops from the front-wheel drive clutch side to the bottom side of the second case portion 212, and the second opening 224 opens on the bottom side of the second case portion 212 toward the front-wheel drive clutch 46. This allows the power transmission device 10 to smoothly take in the oil that has been used to lubricate the front-wheel drive clutch 46 and then dropped to the bottom side of the second case portion 212 into the tubular portion 220. Therefore, the power transmission device 10 can effectively use the tubular portion 220 provided in the accommodation case 200 as a path for smoothly returning oil from the second case portion 212 side to the first case portion 210 side.

[0060] (g) In the power transmission device 10 of this embodiment, the first case portion 210 accommodates the transmission 20 to which the power output from the driving force source 12 is input, and the second case portion 212 accommodates the front-wheel drive clutch 46 to which the power output from the transmission 20 is input, and the solenoid valve 46a for operating the front-wheel drive clutch 46, and the harness 230 is connected to the solenoid valve 46a. This makes it possible to easily route the harness 230 inside the accommodation case 200 even when the transmission 20 is assembled in the first case portion 210 and the front-wheel drive clutch 46 and the solenoid valve 46a are assembled in the second case portion 212.

[0061] (h) In the power transmission device 10 of this embodiment, the housing case 200 further includes a third case portion 214 connected to the second case portion 212 on the opposite side to the first case portion 210, and the first case portion 210 houses the transmission 20 to which power output from the driving force source 12 is input, and the third case portion 214 houses the transfer 22. The power transmission device 10 also houses, in the second case portion 212, a front-wheel drive clutch 46 that selectively connects or disconnects the power transmission path between the transmission 20 and the transfer 22, and a solenoid valve 46a for operating the front-wheel drive clutch 46. This configuration makes it possible to easily route the harness 230 in the power transmission device 10 used in a four-wheel drive vehicle such as the vehicle V described above.

[0062] <<Variations>> The power transmission device 10 illustrated in the above embodiment is merely an example of one embodiment of the present invention, and the configuration can be changed or omitted as appropriate within the scope of the spirit of the present invention.

[0063] Specifically, in this embodiment, an example has been shown in which the cylindrical portion 220 is used to form an oil return path that returns oil from the second case portion 212 to the oil pan 210a provided in the first case portion 210, but the present invention is not limited to this. Specifically, it is also possible to form the second opening 224 on the upper side of the second case portion 212, for example, to achieve a configuration in which oil is less likely to flow into the cylindrical portion 220.

[0064] In the power transmission device 10 of this embodiment, part or all of the tubular portion 220 is formed to have a downward slope from the second opening 224 side toward the first opening 222 side, but the present invention is not limited to this. For example, the power transmission device 10 may have the tubular portion 220 provided substantially horizontally, or may be formed to have a downward slope from the first opening 222 side toward the second opening 224.

[0065] In the power transmission device 10 of this embodiment, the opening area of ​​the first opening 222 is larger than the opening area of ​​the second opening 224, but the present invention is not limited to this. For example, in the power transmission device 10, the opening areas of the first opening 222 and the second opening 224 may be substantially the same, or the opening area of ​​the second opening 224 may be larger than the opening area of ​​the first opening 222. By making the opening area of ​​the second opening 224 larger than the opening area of ​​the first opening 222, the power transmission device 10 is expected to have the effect of making it easier for oil to be taken into the interior of the tubular portion 220 from the second opening 224.

[0066] The power transmission device 10 of this embodiment has been illustrated as having an enlarged portion 226 in the middle of the tubular portion 220, and the tubular portion 220 is formed so that the cross-sectional area decreases from the first opening 222 side to the second opening 224 side on the first opening 222 side and the second opening 224 side with respect to the enlarged portion 226, but the present invention is not limited to this. The tubular portion 220 may be formed so that the cross-sectional area decreases from the first opening 222 side to the second opening 224 side over the entire tubular portion 220, or the cross-sectional area may not change over the entire tubular portion, or the cross-sectional area may decrease from the second opening 224 side to the first opening 222 side, contrary to the above embodiment.

[0067] In the illustrated embodiment, the power transmission device 10 accommodates the front-wheel drive clutch 46 inside the second case portion 212 as a device to which lubricating oil is supplied. However, the present invention is not limited to this. Instead of or in addition to the front-wheel drive clutch 46, another device to which lubricating oil is supplied may be accommodated. Furthermore, in the illustrated embodiment, the second opening 224 is open at the bottom side of the second case portion 212 relative to the front-wheel drive clutch 46, and oil used to lubricate the front-wheel drive clutch 46 can be recovered from the second opening 224 into the tubular portion 220. However, the present invention is not limited to this. As described above, the power transmission device 10 may be configured such that the second opening 224 is located at a position where oil is less likely to flow in, such as the upper side of the second case portion 212.

[0068] In the power transmission device 10 of this embodiment, an example has been shown in which the harness 230 connected to the solenoid valve 46a for operating the front-wheel drive clutch 46 is routed using the tubular portion 220, but the present invention is not limited to this. The power transmission device 10 may also be configured such that, in addition to or instead of the harness 230 connected to the solenoid valve 46a, a harness connected to other devices or the like is routed using the tubular portion 220.

[0069] The power transmission device 10 of this embodiment is mounted on a four-wheel drive vehicle V, with the transmission 20, to which power output from the driving power source 12 is input, housed in the first case portion 210 and the transfer 22 housed in the third case portion 214, but the present invention is not limited to this. The power transmission device 10 may be mounted on a four-wheel drive vehicle that does not have the third case portion 214 or the transfer 22, for example.

[0070] The present invention is not limited to the above-described embodiments and variations thereof, and other embodiments may be possible within the scope of the claims. The components of the above-described embodiments may be arbitrarily selected and combined. Furthermore, any component of the embodiments may be arbitrarily combined with any component described in the Summary of the Invention or any component embodying any component described in the Summary of the Invention. The present invention intends to obtain rights to these as well through amendments to this application or divisional applications, etc. [Industrial Applicability]

[0071] The present invention can be suitably used in control devices for four-wheel drive vehicles in general, which are equipped with a first clutch that selectively disconnects or connects the power transmission path between a driving force source and a power transmission member, and a second clutch that selectively disconnects or connects the power transmission path between the power transmission member and an auxiliary drive wheel. [Explanation of symbols]

[0072] 10: Power transmission device 12: Driving force source 18: Power transmission mechanism 20: Transmission 22: Transfer 46: Front wheel drive clutch (device) 46a: Solenoid valve (clutch actuator) 200: Storage case 210: First case part 210a: Oil pan 212: Second case part 214: Third case part 220: Cylindrical part 222:First opening 224:Second opening 230: Harness V: Vehicle X: Connection direction

Claims

1. A power transmission device that transmits power input from a driving power source in a vehicle, a housing case that houses the power transmission mechanism; a harness routed inside the housing case, the storage case includes a first case portion and a second case portion connected to the first case portion, and has a cylindrical portion formed in a cylindrical shape so as to connect a first opening that opens toward the first case portion in a connecting direction of the first case portion and the second case portion, and a second opening that opens on the opposite side of the connecting direction from the first opening, the cylindrical portion has an enlarged portion in an intermediate portion extending from the first opening to the second opening, the enlarged portion having an increased cross-sectional area, and the cylindrical portion is formed so that the cross-sectional area decreases at a portion closer to the first opening and / or the second opening than the enlarged portion; The power transmission device is characterized in that the harness is routed in the connecting direction through the cylindrical portion.

2. The first case portion has an oil pan, 2. The power transmission device according to claim 1, wherein the cylindrical portion is capable of forming an oil return path for returning oil from the second case portion to the oil pan provided in the first case portion.

3. 3. The power transmission device according to claim 1, wherein a part or all of the cylindrical portion is formed to have a downward slope from the second opening side toward the first opening side.

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