JP2015229423A - Power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission device capable of improving the durability of a transfer case while reducing the size of the power transmission device.SOLUTION: A power transmission device comprises: a transfer case 52; and a transfer mechanism including a transfer pinion, the transfer case 52 including a main body 81 fastened to a sidewall of a transmission case 36 fastened to one end of an engine 2 and accommodating therein a transmission mechanism and a front drive shaft 6R, and a support part 82 protruding from the main body 81 rearward in a vehicle front-rear direction and supporting the transfer pinion, the main body 81 being formed so that an axis of the main body 81 extends in a vehicle width direction, a plurality of main body boss parts 102 through which fastening bolts 68 pass being formed on an outer circumference of the main body 81, a lower main body boss part 103 included in the plurality of main body boss parts 102 and located downward of the support part 82 in a vehicle vertical direction being coupled to a first lower fastening boss part 113 of the support part 82 by a first rib 91.

Description

  The present invention relates to a power transmission device that transmits engine power, and more particularly, to a power transmission device that includes a transfer case that houses a transfer mechanism.

  Conventionally, as a power transmission device of this type, for example, as described in Patent Document 1, a transmission case that is fastened to one end portion of an engine in the vehicle width direction and accommodates a differential mechanism, and the other end of the transmission case in the vehicle width direction And a transfer case that is fastened to the rear side of the unit and accommodates a transfer mechanism has been proposed.

  A conventional power transmission device is configured to receive power output from a transmission, change a power transmission direction by a transfer mechanism, and output the power to a propeller shaft. The transfer case is arranged near the rear part of the engine and has a structure in which an attachment part for attaching the propeller shaft is provided on the rear side. The attachment portion is formed on the main body portion of the transfer case on the side opposite to the transmission side and offset from the end surface of the transfer case.

JP 2001-2730342 A

  However, in the conventional power transmission device described in Patent Document 1, the mounting portion is located at a position offset from the end face of the transfer case. Therefore, the transfer case becomes larger in the width direction of the vehicle, and the power transmission device becomes larger. There's a problem.

  Furthermore, since the attachment portion is located at a position offset from the end face of the transfer case and the attachment portion protrudes from the transfer case, so-called overhanged state, there is a problem of durability. That is, the rotation of the propeller shaft attached to the attachment portion causes loads in the vehicle front-rear direction and the vehicle up-down direction on the attachment portion. This load is likely to be applied to the overhanged portion of the attachment portion, stress on the load is concentrated on the attachment portion, and the durability around the attachment portion and the attachment portion may be reduced.

  The present invention has been made to solve the above problems, and it is an object of the present invention to provide a power transmission device capable of improving the durability of the transfer case while reducing the size of the power transmission device. And

  A first aspect of the present invention for solving the above-described problems includes a transfer case fastened to a side wall of a transmission case attached to an engine that protrudes rearward in the vehicle front-rear direction, a front wheel or a rear wheel housed in the transfer case And a transfer mechanism having a transfer pinion that transmits power through one of the propeller shafts, wherein the transmission case transmits power to the transmission mechanism and the other of the front wheels or the rear wheels. A transfer shaft is housed, fastened to one end of the engine in the vehicle width direction, and a transfer case is fastened to the side wall by a fastener, and protrudes rearward from the main body in the vehicle front-rear direction. And a support part for supporting the pinion so that the axis of the main body part extends in the vehicle width direction. A body boss is formed on the outer periphery of the body, and a plurality of body bosses that pass fasteners are formed on the outer periphery of the body. Part and the lower side wall part of a support part are comprised from what was connected by the rib.

  As a second aspect of the present invention, a plurality of fastening boss portions are formed so that the support portion fastens the bearing that rotatably supports the transfer pinion to one end portion in the axial direction of the support portion with a fastener. The lower side wall of the support portion is composed of a lower fastening boss portion located on the lower side in the vehicle vertical direction among the plurality of fastening boss portions, and one end portion of the rib is connected to the lower fastening boss portion. You may make it do.

  As a third aspect of the present invention, the transfer mechanism has a transfer bevel gear disposed on the transmission case side with respect to the center of the transfer mechanism in the vehicle width direction so as to transmit power to the transfer pinion. The transfer bevel gear meshes with the transfer bevel gear on the transmission width side of the vehicle in the vehicle width direction, and the support portion is located at least part of the rotation shaft of the transfer pinion on the transmission case side with respect to the joint surface joining the transmission case of the main body. The lower fastening boss is located farthest from the transfer bevel gear, and the rib extends from the rear end of the lower fastening boss along the outer peripheral surface. Extends to the front end of the side fastening boss Later, may be from the front end of the lower fastening boss portion to the lower body boss is formed so as to curve in a curve having any curvature.

  As a fourth aspect of the present invention, when the rib is the first rib and the lower fastening boss is the first lower fastening boss, the transmission case is configured so that the main body supports the rotating shaft of the transfer bevel gear. A bearing portion formed on the joining surface side to be joined to the first body, a second rib for connecting the first lower fastening boss portion and the bearing portion, a lower body boss portion and the bearing portion along the joining surface of the body portion, The second rib and the third rib may be in a position surrounding the first rib, and the second rib and the third rib may be connected by the first rib. .

  According to a fifth aspect of the present invention, the support portion is a second lower side fastening that is located below the support portion and farthest from the joint surface among the plurality of fastening boss portions formed on the support portion. You may make it have a 4th rib which connects a boss | hub part and the vertical side wall part couple | bonded with the lower body boss | hub part which is a side wall part of a transfer case so as to oppose a 1st rib.

  As a sixth aspect of the present invention, the support portion extends obliquely upward from the lower end portion of the fourth rib in the vehicle vertical direction toward the upper end portion of the first rib so as to connect the fourth rib and the first rib. A fifth rib and a sixth rib extending diagonally downward from the upper end of the fourth rib in the vehicle vertical direction toward the lower end of the first rib and connecting the fourth rib and the first rib; You may make it a 5 rib and a 6th rib cross | intersect on the bottom face of a support part.

  As a seventh aspect of the present invention, the first rib includes a horizontal portion extending forward in the vehicle front-rear direction along the first lower fastening boss portion, and a lower main body from the front end portion of the horizontal portion in the vehicle front-rear direction. You may make it have a curved part extended with an arbitrary curvature toward a boss | hub part, and the one end of a 6th rib may be connected with the boundary part of a horizontal part and a curved part.

  As an eighth aspect of the present invention, the protruding height from the proximal end to the distal end of the fifth rib may be higher than the protruding height from the proximal end to the distal end of the sixth rib.

  As described above, according to the first aspect, the main body boss portion formed on the main body portion of the transfer case fastened to the transmission case is formed with the axis extending in the vehicle width direction and has high rigidity. doing. A lower side wall portion of the support portion that protrudes rearward in the vehicle front-rear direction from the main body portion of the transfer case is connected to the high-rigidity main body boss portion by a rib, so that the rigidity of the main body portion and the support portion is increased.

  Since the transfer pinion is firmly supported by the support portion having high rigidity, when power is transmitted from the transfer pinion to the other of the front wheel or the rear wheel via the propeller shaft, the reaction force against the transmitted power is The support portion is prevented from vibrating, the occurrence of vibration in the transfer case is suppressed, and the durability of the transfer case is improved.

  According to said 2nd aspect, the fastening boss | hub part formed in the flange is formed so that an axis line may extend in the vehicle front-back direction at the one end part of the axial direction of a support part, and it has high rigidity. The lower side wall portion of the support portion is configured by a lower fastening boss portion located on the lower side in the vehicle vertical direction of the high-rigidity fastening boss portion, and one end portion of the rib is connected to the lower fastening boss portion. Therefore, the rigidity of the main body portion and the support portion is further increased.

  Since the transfer pinion is firmly supported by the support portion having high rigidity, when power is transmitted from the transfer pinion to the other of the front wheel or the rear wheel via the propeller shaft, the reaction force against the transmitted power is The support portion is prevented from vibrating, the occurrence of vibration in the transfer case is suppressed, and the durability of the transfer case is improved.

  According to said 3rd aspect, a support part bulges in the transmission case side so that at least one part of the rotating shaft of a transfer pinion may be located in the transmission case side with respect to the joint surface joined with the transmission case of a main-body part. Thus, the support portion can be arranged so as to overlap the transmission case in the vehicle front-rear direction. As a result, the size of the power transmission device in the vehicle width direction can be shortened, and the power transmission device can be downsized.

  By reducing the size of the power transmission device, the support part protrudes from the main body to the transmission case side in the vehicle width direction, so-called overhanging shape, but the rigidity of the transfer case is further enhanced by the rib shape. It is done. That is, after the rib extends from the rear end portion of the lower fastening boss portion to the front end portion of the lower fastening boss portion along the outer peripheral surface, it is optional from the front end portion of the lower fastening boss portion to the lower body boss portion. Therefore, the rigidity of the transfer case is further increased.

  As a result, the swinging and vibration of the support portion caused by the propeller shaft in the longitudinal direction of the vehicle and the swinging motion of the support portion which is excited by the load generated between the rotation shaft of the transfer bevel gear and the rotation shaft of the transfer pinion Vibration can be suppressed. Moreover, it can suppress that the vibration and deformation | transformation of the component around a support part connected to a support part increase. As a result, the durability of the transfer case can be improved.

  According to said 4th aspect, it has a 2nd rib which connects a 1st lower side fastening boss | hub part and the bearing part of a main-body part, and a 3rd rib which connects a lower body boss | hub part and a bearing part. In addition, one end of each of the second rib and the third rib is a bearing portion, and the other end of each is connected by the first rib. As a result, even if the support portion is shaken or vibrated in the vehicle up-down direction and the vehicle width direction, the stress and strain generated in the first rib are distributed to the second rib and the third rib, and the stress and strain are applied to the first rib. Can be prevented from concentrating.

  That is, the load transmitted from the first lower fastening boss portion to the first rib can be distributed to the second and third ribs and further to the bearing portion. As a result, stress and strain can be prevented from concentrating on the support portion and the components around the support portion connected to the support portion, and the durability of the transfer case can be enhanced.

  According to said 5th aspect, the 4th rib which connects a 2nd lower side fastening boss | hub part and the vertical side wall part of a transfer case can suppress the shaking and vibration of a vehicle up-down direction which arise in a support part by a propeller shaft. . Thereby, the load transmitted to the first rib can be dispersed by the fourth rib, the stress or strain concentrated on the lower part of the support portion can be relieved, and the durability of the transfer case can be improved.

  According to said 6th aspect, since the support part has the 5th rib and 6th rib which mutually cross | intersect in the bottom face of a support part, the boundary of a support part's bottom face and a support part and a main-body part The rigidity of the part can be increased. Thereby, the shaking and vibration of the support portion in the vehicle vertical direction can be reliably suppressed.

  According to the seventh aspect, since one end of the sixth rib is connected to the boundary portion between the horizontal portion and the curved portion of the first rib, the behavior of the first rib changes between the horizontal portion and the curved portion. The boundary portion can be reinforced with the sixth rib, and the load applied to the first rib is reduced. Thereby, stress concentration can be prevented from occurring at the boundary portion between the horizontal portion and the curved portion, and the durability of the transfer case can be enhanced.

  According to said 8th aspect, since the protrusion height of a 5th rib is higher than the protrusion height of a 6th rib, it is a support part used as the part which protrudes from the joint surface by the side of the transmission of a main-body part. The vibration of the so-called overhanging support portion is suppressed.

  Thereby, the displacement in the region of the support portion where the first lower fastening boss portion is arranged and the displacement of the region of the support portion where the second lower fastening boss portion is arranged can be made uniform. The stress applied to the bottom portion or the boundary portion between the support portion and the main body portion can be dispersed, and the durability of the transfer case can be enhanced.

FIG. 1 is a plan view showing a schematic configuration of a vehicle equipped with a power transmission device according to an embodiment of the present invention. FIG. 2 is a side view of the front portion of the vehicle on which the power transmission device according to the embodiment of the present invention is mounted. FIG. 3 is a bottom view showing the bottom side of the power transmission device according to the embodiment of the present invention. FIG. 4 is a rear view showing the rear side of the power transmission device according to the embodiment of the present invention. FIG. 5 is a cross-sectional view showing a VV cross section of FIG. 4. FIG. 6 is a cross-sectional view showing a VI-VI cross section of FIG. FIG. 7 is an exploded perspective view in which a part of the power transmission device according to the embodiment of the present invention is disassembled. FIG. 8 is a front view of the transfer case of the power transmission device according to the embodiment of the present invention as viewed from the transmission case side. FIG. 9 is a perspective view of the power transmission device according to the embodiment of the present invention as seen from the obliquely rear lower side.

  Hereinafter, a power transmission device 5 according to an embodiment in which a power transmission device according to the present invention is applied to a vehicle 1 will be described with reference to FIGS.

First, the configuration will be described.
As shown in FIG. 1, the vehicle 1 includes an engine 2, a transmission 3, a front differential 4, a power transmission device 5, left and right front drive shafts 6L and 6R, and left and right rear drive shafts 7L and 7R. The left and right front wheels 8L and 8R, the left and right rear wheels 9L and 9R, the propeller shaft 11, and the rear differential 12 are configured.

  The vehicle 1 is a full-time vehicle comprising a so-called FF (Front engine Front drive) vehicle base that always drives the left and right front wheels 8L and 8R and the left and right rear wheels 9L and 9R by the power output from the engine 2 disposed on the front side. It consists of a four-wheel drive vehicle. The vehicle 1 is a full-time four-wheel drive vehicle consisting of a so-called RR (Rear engine Rear drive) vehicle base that always drives the left and right rear wheels and the left and right front wheels by the power output from the engine disposed on the rear side. It may be.

  Here, in this embodiment, the front / rear, left / right, and up / down directions are indicated by arrows in the drawing so as to coincide with the front / rear direction, the left / right direction, and the up / down direction seen from the driver seated in the driver's seat of the vehicle 1. ing.

  The engine 2 is a four-stroke engine that performs a series of four strokes including an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke while a piston (not shown) reciprocates two cylinders. The piston is connected to a connecting rod and a crankshaft (not shown), and the power of the engine 2 is output from the crankshaft to the transmission 3.

  The transmission 3 includes a transmission mechanism 31, an input shaft 32, a counter shaft 33, a counter gear 34, a reverse shaft 35, and a transmission case 36 that accommodates these components.

The speed change mechanism 31 includes a plurality of gears incorporated in the input shaft 32, the counter shaft 33, and the reverse shaft 35. The speed change mechanism 31 changes the power of the engine 2 input to the input shaft 32 and outputs it to the front differential 4 via the counter gear 34 incorporated in the counter shaft 33.
The input shaft 32, the counter shaft 33, and the reverse shaft 35 are rotatably supported by the transmission case 36.

  As shown in FIGS. 1 to 4, the transmission case 36 is fastened to the left side of the engine 2 in the vehicle width direction, and includes a first case 41 having a side wall 41 a that protrudes rearward in the vehicle front-rear direction, The second case 42 includes a side wall 42a that is fastened to the left side in the vehicle width direction and protrudes rearward in the vehicle front-rear direction.

The second case 42 accommodates the speed change mechanism 31, the input shaft 32, the counter shaft 33, the counter gear 34, and the reverse shaft 35.
The front differential 4 is accommodated inside the side wall 41a of the first case 41, and a part of the front drive shaft 6R as a power transmission shaft is accommodated and is rotatably supported by the first case 41. A part of the front drive shaft 6L as a power transmission shaft is accommodated inside the side wall 42a of the second case 42 and is rotatably supported by the second case 42.

  As shown in FIG. 1, the front differential 4 has a differential mechanism 45 and a final gear 46 that meshes with the counter gear 34 and transmits power from the transmission mechanism 31 to the differential mechanism 45.

  The differential mechanism 45 includes a differential case 45a that is rotatably supported inside the side wall 41a of the first case 41, and a differential mechanism portion 45b that is accommodated in the differential case 45a. The left and right front drive shafts 6L and 6R are connected to the differential mechanism portion 45b, and the differential mechanism portion 45b provides power while allowing a rotational difference between the left and right front drive shafts 6L and 6R. To communicate.

  As shown in FIGS. 1, 5, and 7, the power transmission device 5 includes a transfer mechanism 51 and a transfer case 52. The power transmission device 5 converts the power input from the front drive shaft 6 </ b> R in a direction orthogonal to the front drive shaft 6 </ b> R and increases the speed to transmit to the propeller shaft 11.

  The transfer mechanism 51 includes a gear 61 provided on the front drive shaft 6R and rotating together with the front drive shaft 6R, a rotary shaft 62 arranged in parallel to the front drive shaft 6R, and a bearing 62a that rotatably supports the rotary shaft 62. 62b. The transfer mechanism 51 includes a transfer bevel gear 63 fixed to the rotation shaft 62 and a gear 64 fixed to the rotation shaft 62 on the right side of the transfer bevel gear 63 and meshes with the gear 61 shown in FIG. 1 to transmit power to the transfer bevel gear 63. And have.

  The transfer mechanism 51 further includes a transfer pinion 65 that converts power in a direction orthogonal to the rotation shaft 62 and transmits the power at an increased speed, a transfer pinion shaft 66 as a rotation shaft that rotates together with the transfer pinion 65, and a transfer pinion shaft. A bearing 67 that rotatably supports 66 and a plurality of fastening bolts 68 that fasten the bearing 67 to the transfer case 52 are provided.

  The transfer bevel gear 63 is disposed closer to the transmission case 36 than the central portion in the vehicle width direction of the transfer mechanism 51 indicated by a chain line CL in FIG. 1, and the transfer pinion 65 shown in FIGS. The bevel gear 63 meshes with the transfer bevel gear 63 on the left side in the vehicle width direction, that is, on the transmission case 36 side.

  As shown in FIGS. 5 and 6, the rear end portion of the transfer pinion shaft 66 in the vehicle front-rear direction is connected to a joint 11a provided at the front end portion of the propeller shaft 11, and the transfer pinion shaft 66 is connected via the joint 11a. It rotates with the propeller shaft 11.

  When the vehicle 1 moves forward, the front drive shaft 6R rotates counterclockwise toward the paper surface as indicated by a solid arrow A in FIG. When the front drive shaft 6R rotates in the counterclockwise direction, the rotating shaft 62 rotates in the clockwise direction indicated by the solid line arrow B in FIGS. 5 and 6 through the gears 61 and 64 shown in FIG. 1, and the transfer bevel gear 63 also changes to the arrow. Rotate clockwise as indicated by B.

  When the transfer bevel gear 63 rotates in the clockwise direction, the transfer pinion 65 rotates counterclockwise as indicated by the solid arrow C from the left side toward the paper surface of FIG. The propeller shaft 11 rotates counterclockwise as indicated by an arrow C. As a result, the power input to the front drive shaft 6R is converted to a right angle and transmitted to the propeller shaft 11.

  When the vehicle 1 moves forward, in the transfer mechanism 51, when power is transmitted from the transfer bevel gear 63 to the transfer pinion 65, as shown by the solid line arrow D shown in FIG. A load Ff is applied downward.

  On the other hand, when the vehicle 1 moves backward, the front drive shaft 6R rotates in the clockwise direction toward the paper surface as indicated by the broken arrow a in FIG. When the front drive shaft 6R rotates in the clockwise direction, the rotating shaft 62 rotates in the counterclockwise direction indicated by the broken-line arrow b in FIGS. 5 and 6 through the gears 61 and 64 shown in FIG. 1, and the transfer bevel gear 63 also has the arrow. It rotates in the counterclockwise direction indicated by b.

  When the transfer bevel gear 63 rotates in the counterclockwise direction, the transfer pinion 65 rotates from the left side toward the paper surface of FIG. The propeller shaft 11 rotates in the clockwise direction indicated by the arrow c. As a result, the power input to the front drive shaft 6R is converted to a right angle and transmitted to the propeller shaft 11.

When the vehicle 1 moves backward, when power is transmitted from the transfer bevel gear 63 to the transfer pinion 65 in the transfer mechanism 51, the transfer pinion shaft 66 moves upward in the vertical direction of the vehicle as indicated by the broken arrow d. A load Fb is applied.
Further, when the vehicle 1 moves forward and backward, a load Fp is applied in the axial direction of the transfer pinion shaft 66 by the propeller shaft 11 as indicated by a solid arrow E in FIG.

  As shown in FIG. 7, the transfer case 52 includes a left case 71 fastened to the side wall 41a of the first case 41 in the transmission case 36, a right case 72 fastened to the left case 71, and the right case 72 as the left case. A plurality of fastening bolts 73 fastened to 71 and a plurality of fastening bolts 74 that fasten the left case 71 to the first case 41 are provided.

  The left case 71 includes a main body 81 fastened to the side wall 41a, and a support that protrudes rearward from the main body 81 in the vehicle front-rear direction and rotatably supports the transfer pinion shaft 66 of the transfer pinion 65 via a bearing 67. 82 and a plurality of boss portions 83 for fastening the light case 72.

  The main body portion 81 and the support portion 82 include a first rib 91, a second rib 92, a third rib 93, a fourth rib 94, a fifth rib 95, and a sixth rib 96 as ribs to be described later. However, it is formed to protrude from the outer periphery of the main body part 81 and the support part 82 with a predetermined width and a predetermined height, and the rigidity of the main body part 81 and the support part 82 is enhanced.

  As shown in FIG. 5, the main body 81 is formed so that the axis of the main body 81 extends in the vehicle width direction, and a part of the left side of the front drive shaft 6 </ b> R, a gear 61, a rotating shaft 62, The bearing 62a, the transfer bevel gear 63, and the gear 64 are accommodated.

  As shown in FIGS. 5 and 8, the main body 81 has a joint surface 81 a that joins the side wall 41 a of the first case 41 in the transmission case 36, and a bearing that houses the bearing 62 a on the joint surface 81 a side. Part 101 is formed.

Further, on the outer periphery of the main body 81, as shown in FIG. 7, a plurality of main body boss portions 102 through which fastening bolts 74 for fastening the left case 71 to the first case 41 pass are linearly formed in the axial direction of the main body 81. Is formed.
The main body boss portion 102 includes a lower main body boss portion 103 located on the lower side in the vehicle vertical direction.

  As shown in FIG. 5, at least a part of the transfer pinion shaft 66 incorporated in the support portion 82 with respect to the joint surface 81 a joined to the side wall 41 a of the first case 41 in the transmission case 36 of the main body 81 is a transmission. The main body 81 is formed so as to bulge toward the transmission case 36 so as to be positioned on the case 36 side.

  As shown in FIGS. 6 and 8, the support portion 82 is a flange formed at one end in the axial direction of the support portion 82 so as to fix the flange portion 67 a of the bearing 67 that rotatably supports the transfer pinion shaft 66. 111. The flange 111 has four fastening boss portions 112 formed in the axial direction of the support portion 82 so as to fasten the flange portion 67 a of the bearing 67 with the fastening bolts 68.

  The fastening boss portion 112 is a position farthest from the joint surface 81a of the main body portion 81 and the first lower fastening boss portion 113 at a position farthest from the transfer bevel gear 63 on the lower side wall portion of the support portion 82 in the vehicle vertical direction. And the second lower fastening boss 114. The first lower fastening boss portion 113 constitutes the lower fastening boss portion of the present invention.

  As shown in FIG. 9, the first rib 91 connects the lower main body boss portion 103 of the main body portion 81 and the first lower fastening boss portion 113 of the support portion 82. Specifically, the first rib 91 extends from the rear end portion of the first lower fastening boss portion 113 to the front end portion of the first lower fastening boss portion 113 along the outer peripheral surface of the support portion 82. After extending, the lower body boss portion 103 and the first lower fastening boss portion 113 are connected from the front end portion of the first lower fastening boss portion 113 to the lower body boss portion 103 of the body portion 81.

  As shown in FIGS. 8 and 9, the first rib 91 includes a horizontal portion 91 a in which the top portion of the first rib 91 extends horizontally forward from the front end portion of the first lower fastening boss portion 113, and the front end of the horizontal portion. And a curved portion 91b that curves and extends with a curved line having an arbitrary curvature from the upper portion to the lower body boss portion 103.

  As shown in FIG. 8, the second rib 92 extends linearly forward from the front end portion of the first lower fastening boss portion 113, so that the bearing portion of the first lower fastening boss portion 113 and the main body portion 81 is provided. 101 is connected.

  The third rib 93 connects the lower main body boss portion 103 and the bearing portion 101 so as to extend from the lower main body boss portion 103 to the bearing portion 101 along the lower joint surface 81a of the main body portion 81 in the vehicle vertical direction. doing. The protruding top portion of the third rib 93 is formed flat and constitutes a part of the joint surface 81a.

  The second rib 92 and the third rib 93 are positioned so as to surround the first rib 91, the connecting portion of the second rib 92 with the first lower fastening boss portion 113, and the lower main body boss of the third rib 93. The first rib 91 is connected to one end of the second rib 92 and one end of the third rib 93 by connecting the connecting portion with the portion 103.

  As shown in FIG. 9, the fourth rib 94 extends from the second lower fastening boss portion 114 toward the front in the vehicle front-rear direction so as to face the first rib 91, and is a side wall portion of the left case 71. Are connected to the vertical side wall portion 71 a coupled to the lower main body boss portion 103.

The fifth rib 95 extends obliquely upward from the lower end of the fourth rib 94 in the vehicle vertical direction toward the upper end of the first rib 91, and connects the fourth rib 94 and the first rib 91.
In contrast to the fifth rib 95, the sixth rib 96 extends obliquely downward from the upper end of the fourth rib 94 in the vehicle vertical direction toward the lower end of the first rib 91, and the fourth rib 94 and the first rib. The horizontal part 91a of 91 and the boundary part of the curved part 91b are connected.

Therefore, the fifth rib 95 and the sixth rib 96 intersect each other on the bottom surface of the support portion 82.
The fifth rib 95 is formed such that the protruding height from the proximal end to the distal end of the fifth rib 95 is higher than the protruding height from the proximal end to the distal end of the sixth rib 96.

  As shown in FIGS. 5 and 7, the right case 72 includes a bearing portion 72 a that houses the bearing 62 b, a plurality of boss portions 72 b that pass fastening bolts 73 that fasten the right case 72 to the left case 71, and the left case 71. And a through hole 72d through which the front drive shaft 6R passes.

Below, the effect of the power transmission device 5 of this embodiment is demonstrated.
According to the power transmission device 5 of the present embodiment, the main body boss portion 102 formed on the main body portion 81 of the left case 71 of the transfer case 52 fastened to the side wall 41a of the first case 41 of the transmission case 36 has a vehicle width. An axis extends in the direction and has high rigidity.
The first lower fastening boss portion 113 of the support portion 82 that protrudes rearward in the vehicle front-rear direction from the main body portion 81 of the left case 71 is connected to the high-rigidity main body boss portion 102 by the first rib 91. The rigidity of 81 and the support part 82 is improved.

  Further, according to the power transmission device 5 of the present embodiment, as shown in FIG. 4, when the power transmission device 5 operates, the first rib 91 is in the direction of the load indicated by the solid line arrow F1 generated when the vehicle moves forward. Further, since it is formed so as to be parallel to the direction of the load indicated by the broken-line arrow F2 generated when the vehicle moves backward, the rigidity against the load generated when the power transmission device 5 operates is remarkably increased.

  Further, according to the power transmission device 5 of the present embodiment, the transfer pinion 65 is firmly supported by the support portion 82 having high rigidity, and therefore the rear wheels 9L and 9R are transferred from the transfer pinion 65 through the propeller shaft 11. When the motive power is transmitted to the support case, the support portion 82 is prevented from vibrating due to a reaction force against the transmitted motive power, and the occurrence of vibration of the transfer case 52 is suppressed, and the durability of the transfer case 52 is improved.

  Further, according to the power transmission device 5 of the present embodiment, the fastening boss 112 formed on the flange 111 shown in FIG. 8 is formed so that the axis extends in the longitudinal direction of the vehicle at one end of the support 82 in the axial direction. And has high rigidity. The lower side wall portion of the support portion 82 is constituted by a first lower fastening boss portion 113 located on the lower side in the vehicle vertical direction of the high-rigidity fastening boss portion 112, and one end portion of the first rib 91 is the first end portion. 1 Since the lower fastening boss portion 113 is connected, the rigidity of the main body portion 81 and the support portion 82 is further increased.

  Further, according to the power transmission device 5 of the present embodiment, the transfer pinion 65 is firmly supported by the support portion 82 having high rigidity, and therefore the rear wheels 9L and 9R are transferred from the transfer pinion 65 through the propeller shaft 11. When the motive power is transmitted to the support case, the support portion 82 is prevented from vibrating due to the reaction force against the transmitted motive power, and the occurrence of vibration of the transfer case 52 is suppressed, thereby improving the durability of the transfer case.

  Further, according to the power transmission device 5 of the present embodiment, at least a part of the transfer pinion shaft 66 is located on the transmission case 36 side with respect to the joint surface 81a joined to the first case 41 of the main body 81 shown in FIG. Thus, the support portion 82 can be disposed so as to overlap the transmission case 36 in the vehicle front-rear direction. As a result, the size of the power transmission device 5 in the vehicle width direction can be shortened, and the power transmission device 5 can be downsized.

  Further, according to the power transmission device 5 of the present embodiment, by reducing the size of the power transmission device 5, the support portion 82 projects from the main body portion 81 toward the transmission case 36 in the vehicle width direction so-called overhang. Although it becomes a hung shape, the shape of the first rib 91 further increases the rigidity of the transfer case 52. That is, the first rib 91 extends from the rear end portion of the first lower fastening boss portion 113 to the front end portion of the first lower fastening boss portion 113 along the outer peripheral surface, and then the first lower fastening boss portion 113. From the front end portion to the lower main body boss portion 103, the transfer case 52 is further improved in rigidity because it is formed to bend along a curve having an arbitrary curvature.

  As a result, the vehicle longitudinal direction of the support portion 82 excited by the vibration and vibration of the support portion 82 generated by the propeller shaft 11 in the longitudinal direction of the vehicle and the load generated between the rotating shaft 62 of the transfer bevel gear 63 and the transfer pinion shaft 66. Can suppress vibration and vibration. Moreover, it can suppress that the vibration and deformation | transformation of the component of the periphery of the support part 82 connected to the support part 82 increase. As a result, the durability of the transfer case 52 can be improved.

  According to the power transmission device 5 of the present embodiment, the second rib 92 that connects the 113 shown in FIG. 8 and the bearing portion 101 of the main body 81, and the second rib 92 that connects the lower main body boss portion 103 and the bearing 101. One end of the second rib 92 and the third rib 93 is connected to the bearing portion 101, and each end portion is connected to the first rib 91.

  As a result, even if the support portion 82 is shaken or vibrated in the vehicle vertical direction and the vehicle width direction, the stress and strain generated in the first rib 91 are distributed to the second rib 92 and the third rib 93, and the first rib It is possible to prevent stress and strain from concentrating on 91. That is, the load transmitted from the first lower fastening boss portion 113 to the first rib 91 can be distributed to the second rib 92 and the third rib 93 and further to the bearing portion 101. Thereby, it is possible to prevent stress and strain from concentrating on the support portion 82 and the components around the support portion 82 connected to the support portion 82, and the durability of the transfer case 52 can be improved.

  Further, according to the power transmission device 5 of the present embodiment, the propeller shaft 11 supports the second lower fastening boss 114 shown in FIG. 9 and the fourth rib 94 that connects the vertical side wall 71a of the left case 71. The vibration and vibration in the vehicle vertical direction generated in the portion 82 can be suppressed. Thereby, the load transmitted to the first rib 91 can be dispersed by the fourth rib 94, the stress or strain concentrated on the lower portion of the support portion 82 can be relieved, and the durability of the transfer case 52 can be enhanced.

  Further, according to the power transmission device 5 of the present embodiment, the support portion 82 includes the fifth rib 95 and the sixth rib 96 that intersect with each other on the bottom surface of the support portion 82, and thus the bottom surface of the support portion 82. And the rigidity of the boundary part of the support part 82 and the main-body part 81 can be improved. Thereby, the shaking and vibration of the support part 82 of a vehicle up-down direction can be suppressed reliably.

  Further, according to the power transmission device 5 of the present embodiment, one end of the sixth rib 96 is connected to the boundary portion between the horizontal portion 91a and the curved portion 91b of the first rib 91, so that a load is applied to the first rib 91. The boundary portion between the horizontal portion 91a and the curved portion 91b where the behavior of the first rib 91 when applied can be reinforced by the sixth rib 96, and the load applied to the first rib 91 is reduced. Thereby, stress concentration can be prevented from occurring at the boundary portion between the horizontal portion 91a and the curved portion 91b, and the durability of the transfer case 52 can be enhanced.

  Further, according to the power transmission device 5 of the present embodiment, since the protruding height of the fifth rib 95 is higher than the protruding height of the sixth rib 96, the joint surface of the main body 81 on the transmission case 36 side. The vibration of the support portion 82 that is a portion protruding from 81a, that is, the vibration of the so-called overhanging support portion 82 is suppressed.

  Thereby, the displacement in the region of the support portion 82 where the first lower fastening boss portion 113 is disposed and the displacement of the region of the support portion 82 where the second lower fastening boss portion 114 is disposed can be made equal. The stress applied to the bottom portion of the support portion 82 or the boundary portion between the support portion 82 and the main body portion 81 can be dispersed, and the durability of the transfer case 52 can be enhanced.

  While embodiments of the invention have been disclosed, it will be apparent to those skilled in the art that changes may be made without departing from the scope of the invention. All such modifications and equivalents are intended to be included in the following claims.

1 ... vehicle, 2 ... engine, 3 ... transmission (transmission mechanism), 5 ... power transmission device, 6L, 6R ... front drive shaft (power transmission shaft), 8L, 8R. .. front wheel, 9L, 9R ... rear wheel, 31 ... transmission mechanism, 36 ... transmission case, 41 ... first case (transmission case), 41a ... side wall, 42 ... first 2 cases (transmission case), 51 ... Transfer mechanism, 52 ... Transfer case, 62 ... Rotating shaft, 63 ... Transfer bevel gear, 65 ... Transfer pinion, 66 ... Transfer pinion shaft ( Rotating shaft), 67 ... Bearing, 68 ... Fastening bolt (fastener), 71 ... Left case (transfer case), 71a ... Vertical side wall, 72 ... Right case (transfer case) 74 ... Fastening bolts (fasteners), 81 ... Main body, 81a ... Joining , 82 ... support part, 91 ... first rib (rib), 91a ... horizontal part, 91b ... curved part, 92 ... second rib, 93 ... third rib, 94 ... 4th rib, 95 ... 5th rib, 96 ... 6th rib, 101 ... Bearing part, 102 ... Body boss part, 103 ... Lower body boss part, 111. ..Flange, 112 ... fastening boss portion, 113 ... first lower fastening boss portion (lower fastening boss portion) 114 ... second lower fastening boss portion

Claims (8)

A transfer case fastened to a side wall protruding rearward in the front-rear direction of a transmission case attached to the engine;
A transfer mechanism having a transfer pinion that is housed in the transfer case and transmits power to one of a front wheel or a rear wheel via a propeller shaft;
A power transmission device comprising:
The transmission case houses a transmission mechanism and a power transmission shaft that transmits power to the other of the front wheels or the rear wheels, and is fastened to one end of the engine in the vehicle width direction,
The transfer case has a main body portion fastened to the side wall by a fastener, and a support portion that protrudes rearward from the main body portion in the vehicle front-rear direction and supports the transfer pinion,
The main body is formed such that the axis of the main body extends in the vehicle width direction, and a plurality of main body bosses through which the fastener is passed are formed on the outer periphery of the main body.
A power transmission device comprising: a lower main body boss portion positioned on a lower side in a vehicle vertical direction of the support portion among the plurality of main body boss portions; and a lower side wall portion of the support portion connected by a rib. . The support portion has a flange formed with a plurality of fastening boss portions so as to fasten a bearing that rotatably supports the transfer pinion to one end portion in the axial direction of the support portion with a fastener,
The lower side wall portion of the support portion is a lower fastening boss portion positioned on the lower side in the vehicle vertical direction among the plurality of fastening boss portions, and one end portion of the rib is connected to the lower fastening boss portion. The power transmission device according to claim 1. The transfer mechanism has a transfer bevel gear disposed on the transmission case side of a center portion in the vehicle width direction of the transfer mechanism so as to transmit power to the transfer pinion;
The transfer pinion meshes with the transfer bevel gear on the transmission case side in the vehicle width direction of the transfer bevel gear,
The support portion is formed so as to bulge toward the transmission case so that at least a part of the rotation shaft of the transfer pinion is located on the transmission case side with respect to a joint surface of the main body portion that joins the transmission case. ,
The lower fastening boss is at a position most distant from the transfer bevel gear;
After the rib extends from the rear end portion of the lower fastening boss portion to the front end portion of the lower fastening boss portion along the outer peripheral surface, the lower body boss portion extends from the front end portion of the lower fastening boss portion. The power transmission device according to claim 2, wherein the power transmission device is formed to be curved with a curve having an arbitrary curvature. When the rib is a first rib and the lower fastening boss is a first lower fastening boss, the joint surface joins the transmission case so as to support the rotation shaft of the transfer bevel gear. A bearing portion formed on the side;
A second rib connecting the first lower fastening boss and the bearing;
A third rib that connects the lower body boss and the bearing along the joint surface of the body;
The said 2nd rib and the said 3rd rib exist in the position which surrounds the said 1st rib, The said 2nd rib and the said 3rd rib are connected by the said 1st rib, The Claim 3 characterized by the above-mentioned. Power transmission device.   The support part is a second lower fastening boss part at a position below the support part and farthest from the joining surface among the plurality of fastening boss parts formed on the support part; 5. A fourth rib for connecting a side wall portion of a transfer case and a vertical side wall portion coupled to the lower body boss portion so as to face the first rib. The power transmission device described. A fifth rib that extends obliquely upward from a lower end of the fourth rib in the vehicle vertical direction toward the upper end of the first rib and connects the fourth rib and the first rib;
A sixth rib extending obliquely downward from an upper end of the fourth rib in the vehicle vertical direction toward a lower end of the first rib and connecting the fourth rib and the first rib;
The power transmission device according to claim 5, wherein the fifth rib and the sixth rib intersect at a bottom surface of the support portion.   The first rib is a horizontal portion that extends forward in the vehicle front-rear direction along the first lower fastening boss portion, and arbitrarily extends from the front end portion of the horizontal portion in the vehicle front-rear direction toward the lower body boss portion. The power transmission device according to claim 6, wherein the power transmission device has a curved portion extending at a curvature of 5 mm, and one end of the sixth rib is connected to a boundary portion between the horizontal portion and the curved portion. 8. The power transmission device according to claim 7, wherein a protruding height of the fifth rib from the proximal end to the distal end is higher than a protruding height of the sixth rib from the proximal end to the distal end.

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