JP2005313809A - Axle driving device for four-wheel drive vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To promote part standardization and cost reduction by enabling a missions case connected with an engine via a CVT to be switched between a form where power is extracted without the alteration of a case structure and a form where power is not extracted. <P>SOLUTION: The missions case 20 for laterally supporting main drive axles 104L and 104R is arranged in front of or at the back of the engine E in the vehicle, and the CVT 4 driven and connected with the engine E is arranged on one of right and left sides of the missions case 20. A PTO case 51 is attached to the end of a flange 20b for supporting the axle 104R on the laterally opposite side to the CVT 4 of the missions case 20. A differential case 31R of a differential gear mechanism for differentially connecting the axle 104R in the missions case 20 is extended along the outer periphery of the main drive axle 104R is used as a PTO shaft, is projected into the PTO case 51, and driven by and connected with a power extraction mechanism in the PTO case 51. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an axle drive device for a four-wheel drive vehicle that can be used both in a state in which power is not taken out from a sub-drive axle and in a state in which power is taken out, without requiring a dedicated housing.

  Conventionally, a first axle drive device that drives a main drive axle and a second axle drive device that drives a secondary drive axle are disposed on the front and rear sides of the fuselage with a prime mover such as an internal combustion engine supported by the fuselage frame interposed therebetween. And an input portion for drivingly connecting to the prime mover via a transmission such as a CVT is provided on the left and right sides of the first axle drive device, and the first axle drive device on the opposite side of the input portion A PTO case (PTO case) for driving the auxiliary drive axle is connected to the left and right other sides, and an output shaft for power extraction that is pivotally supported by the PTO case is connected to the input portion of the second axle drive device. On the other hand, a multi-wheel drive vehicle having a structure in which a universal joint, a transmission shaft, and the like are connected to drive is known, such as a four-wheel drive vehicle described in Patent Document 1.

JP 2001-182562 A (FIGS. 1 and 2)

  The first axle drive device can be modified to be adapted to a so-called two-wheel drive vehicle that does not drive an axle other than the main drive axle. In this case, a PTO case is not required, but conventionally, as shown in Patent Document 1, an intermediate shaft in the first axle drive device is used as a power take-out shaft (PTO shaft) for driving the auxiliary drive axle. The left and right sides of the intermediate shaft protrude and are connected to the output shaft for power extraction by a bevel gear or the like in the PTO case. Therefore, even if the PTO case is removed, the protruding end of the intermediate shaft remains. Even if the intermediate shaft itself is replaced with one that fits within the transmission case that constitutes the first axle drive device, the transmission case will still have an opening for projecting the intermediate shaft. In order to eliminate such an opening, it is necessary to prepare a mission case that does not have an opening for projecting the intermediate shaft and that has a specification that does not extract the power separately from the specification that performs the power extraction. Cost. In many cases, the axle drive device is attached to the vehicle body in an upright posture in order to keep the overall length of the vehicle short. In such a posture, the input shaft, the intermediate shaft, and the axle are arranged in order from the vertical direction, and the position of the intermediate shaft is largely offset upward from the position of the input shaft of the second axle drive device. As a result, the bending angle of the universal joint was increased, resulting in greater noise and vibration, making it uncomfortable to ride.

  The vehicle transmission apparatus according to the present invention solves the above problems by the following means. First, as described in claim 1, a transmission case that supports the main drive axle to the left and right is disposed in front of or behind the prime mover in the vehicle, and on the left and right sides of the transmission case, the prime mover and the transmission case And a belt transmission device for driving and connecting to the other axle drive mechanism, and for driving the auxiliary drive axle to the support end of the main drive axle on the opposite side of the transmission case to the belt transmission device. The PTO case is attached.

  Alternatively, the cover member that covers the shaft support end portion of each of the main drive axles on the left and right sides in the transmission case that supports the main drive axle to the left and right as described in claim 4 can be used as a PTO case for driving the auxiliary drive axle. It is assumed that the exchange is possible.

  In such a vehicle transmission device according to claim 1 or claim 4, preferably, as in claim 2 or claim 5, the axle drive mechanism in the transmission case is configured such that the pair of left and right main drive axles are connected to each other. A differential gear mechanism for differentially connecting the PTO case to the differential case of the differential gear mechanism. It is made to enter and is connected to the power take-out mechanism in the PTO case.

  In the vehicle transmission device according to claim 2 or 5, preferably, the transmission shaft on the upper side of the differential gear mechanism is pivoted in the transmission case as described in claim 3 or claim 6. The output gear shaft is connected to the differential gear mechanism via a reduction drive train, and the output shaft for power extraction is connected to the projecting end of the differential case via the drive train in the PTO case. In addition, the speed increasing ratio of the drive train in the PTO case is set to be substantially the same as the speed reducing ratio of the speed reducing drive train in the transmission case.

  The present invention has the following effects by the means described above. First, as described in claim 1, in the transmission case, when the power take-off is newly performed by using the supporting end portion of the axle that is originally opened for the protrusion of the main drive axle as the attachment portion of the PTO case. Therefore, there is no need to provide an opening for projecting the power take-off shaft, and therefore, a common transmission case can be used when power is taken out and when it is not taken out. Then, by attaching such a PTO case to the transmission case on the opposite side to the belt transmission device, not only the PTO case but also a transmission mechanism such as a universal joint extending from the PTO case can be used. It can be installed in the vehicle without interfering with the device. In addition, since power can be extracted at the same level as the lowest axle of the axle drive units, the universal joint connecting the second axle drive unit has a smaller folding angle in the vertical direction, resulting in vibration and noise. The ride comfort of the vehicle can be improved.

  Alternatively, according to the fourth aspect of the present invention, in the transmission case, the PTO case for driving the auxiliary driving axle from the supporting end portion of the axle that is opened for the protrusion of the main driving axle by simply removing the cover member. By using it as an attachment part, it is not necessary to newly provide an opening for projecting the power take-out shaft when taking out the power, and therefore, the mission case is shared between the case of taking out the power and the case of not taking it out. it can. Then, by making such a PTO case replaceable with either of the left and right cover members, for example, when it is desired to attach to the transmission case on the opposite side to the belt transmission device, the belt transmission device is The PTO case and a transmission mechanism such as a universal joint extending from the PTO case can be arranged in the vehicle without interfering with the belt transmission device, regardless of whether the PTO case is arranged on the left or right side of the vehicle. In addition, since power can be extracted at the same level as the lowest axle of the axle drive units, the universal joint connecting the second axle drive unit has a smaller folding angle in the vertical direction, resulting in vibration and noise. The ride comfort of the vehicle can be improved.

  Further, as described in claim 2 or claim 5, the differential case in the transmission case is extended on the outer periphery of the one main drive axle and protrudes from the transmission case as a power take-off shaft, whereby the one main drive axle is The opening of the transmission case for projecting the main drive axle at the support end can be shared as an opening for projecting the differential case extension. Further, as described in claim 3, by making it possible to attach a PTO case to the support end portion of the main drive axle, the axle drive apparatus has a common mission case regardless of whether or not power is taken out. Can be used.

  According to the third or sixth aspect of the present invention, the rotational speed of the output shaft for power extraction can be set so that the output shaft for power extraction is the intermediate shaft of the axle drive device (as in the prior art). The rotational speed of the output shaft obtained when the PTO case configured to be connected to the transmission gear on the upper side of the differential gear mechanism is attached to the housing of the axle drive device can be made substantially equal. Therefore, when the transmission case according to the present invention is used as the transmission case of the first axle driving device, the specifications of the second axle driving device described in the background art are the same as those of the conventional first axle driving device. It is not necessary to change from the second axle drive device in the case where the intermediate shaft in the case is used as a power take-out shaft.

  First, the configuration of a four-wheel drive vehicle using the transmission case 20 of the axle drive device T1 according to the present invention will be described with reference to FIGS. The main body of the transport vehicle is configured by connecting a front frame 2 and a rear frame 1 in the front-rear direction. The rear frame 1 includes a horizontal floor plate that is substantially rectangular in plan view, and vertical side plates that are erected on the front, rear, left and right ends of the floor plate. A loading platform 3 is preferably disposed above the rear frame 1 so as to be pivotable up and down, and the rear frame 1 also serves as a support platform for the loading platform 3.

  An engine E as a prime mover is disposed in the rear frame 1 in such a manner that a crankshaft is arranged in the left-right direction. In this embodiment, an output shaft 100 projects from the left side of the vehicle. A first axle drive device T1 according to the present invention is disposed behind the engine E, and an input shaft 101 thereof is provided on the left side of the vehicle so as to be parallel to the output shaft 100 of the engine. The engine output shaft 100 and the input shaft 101 of the first axle drive device T1 are drivingly connected by a belt transmission device 4 such as a belt-type continuously variable transmission (CVT). The first axle drive device T1 incorporates a forward / reverse switching mechanism to be described later.

  The first axle drive device T1 has a pair of left and right main drive axles 104L and 104R extending in the left-right reciprocal direction, and each of the main drive wheels disposed outside the left and right side plates of the rear frame 1 is rear. Drive connected to the wheel 5. A brake 5b is provided in the rim of each rear wheel 5. A wheel shaft 5a, which is a central axis of each rear wheel 5, passes through a rear wheel bearing support member 6 that is attached to the left and right side plates of the rear frame 1 and protrudes outward from the left and right. 6 is supported by a bearing 6a. In the rear frame 1, splines are formed at the inner ends of the rear wheel shafts 5 a and the outer ends of the axles 104 </ b> L and 104 </ b> R, and splines meshing with these are formed on the inner peripheral surface of the sleeve-like coupling 108. In addition, the inner end of the rear wheel shaft 5a and the outer ends of the axles 104L and 104R are fitted into the coupling 108 in a splined direction (see FIG. 3), and these are connected so as to be integrally rotatable. The left and right axles 104L and 104R and the left and right wheel axles 5a and 5a are set to appropriate lengths in consideration of the arrangement position of the first axle drive device T1 in the left and right direction. Since the left and right axles 104L and 104R have substantially the same length, the first rear axle 5a is made longer because the first axle drive device T1 is moved to the left of the vehicle.

  The front half of the front frame 2 is one step higher than the rear half, and the second axle drive device T2 is disposed at a substantially horizontal center position below the front half. The second axle drive device T2 has a pair of left and right auxiliary drive axles 106, 106 extending in the left-right reciprocal direction, and is steered on the left and right outer sides of the front half of the front frame 2, respectively. The universal joint 13 and the transmission shaft 14 are drivingly connected to the front wheel shaft 7a which is the central axis of the front wheel 7 which is each auxiliary drive wheel which is arranged to be movable. A front cover 2a is erected on the front half of the front frame 2, the rear upper part is an operation / instrument panel, and a round handle 8 is disposed above the front cover 2a. A conventional suspension mechanism (not shown) composed of a coil spring, a shock absorber, or the like is extended from the front frame 2 front left and right side ends to the front wheel shafts 7a. Suspended.

  On the portion behind the rear end of the front cover 2a, which is the rear half of the front frame 2, a tread is laid to form a horizontal platform 2b. As can be seen in FIG. 2, the platform 2b extends to the left and right outer sides. A driver's seat 9 is erected above the rear end of the front frame 2a (immediately before the rear frame 1 and the loading platform 3), and the platform 2b extends on the left and right and the front thereof.

  Here, the internal structure of the first axle drive device T1 according to the present invention will be described with reference to FIGS. The transmission case 20 which is a housing of the first axle drive device T1 is formed by joining substantially symmetric case halves 20L and 20R via a vertical plane. The transmission case 20 has a lower end (specifically, a lower end of each case half 20L, 20R) that is bolted to the floor surface of the rear frame 1 with a bolt, so that it is adjacent to the engine in the vehicle. It is fixed in an almost upright position. That is, in the transmission case 20, the input shaft 101 is disposed at the top, the left and right axles 104L and 104R are disposed at the bottom, and the intermediate shaft 102 is disposed at a height between the input shaft 101 and the axles 104L and 104R. These are pivotally supported in parallel to the left and right.

  In the transmission case 20, a clutch gear 21 and a clutch sprocket 22 are loosely fitted on the input shaft 101 in a left-right manner, and the input shaft 101 is interposed between the gear 21 and the sprocket 22. The clutch slider 23 is slidably provided in the axial direction. The clutch slider 23 is engaged with either the gear 21 or the sprocket 22 and engaged with the input shaft 101 so as to be integrally rotatable. The gear 21 and the sprocket 22 can be separated from each other to be in a state (neutral state) where power is not transmitted to the axles 104L and 104R. The positioning of the clutch slider 23 in the axial direction is performed by operating a forward / backward / neutral selection operation tool (switch, lever, etc.) provided at the rear end of the front cover 2a, the side of the driver's seat 8, or the like.

  A gear 24 and a sprocket 26 are fixed on the intermediate shaft 102 below the input shaft 101, and the gear 24 is always meshed with the clutch gear 21, and the sprocket 26 is Drive coupled to the clutch sprocket 22. When power is transmitted to the gears 21 and 24, the intermediate shaft 102 is opposite to the input shaft 101. When power is transmitted to the sprockets 22 and 26 and the chain 25, the intermediate shaft 102 is the same as the input shaft 101. Will rotate in the direction. Thus, there is provided a mechanical forward / reverse switching mechanism that provides a drive train composed of gears 21 and 22 and a drive train composed of sprockets 22 and 26 and a chain 25, one as a forward drive train and the other as a reverse drive train. The input shaft 101 and the intermediate shaft 102 are configured.

  A final pinion 27 is formed on the intermediate shaft 102 between the gear 24 and the sprocket 26, and a bull gear 28 of a differential gear mechanism provided between the left and right axles 104L and 104R below the intermediate shaft 102 is engaged. ing. A differential pinion shaft 29 is pivotally supported in the bull gear 28 between the inner ends of the axles 104L and 104R in a direction perpendicular to the axis of the axles 104L and 104R (diameter direction of the bull gear 28). A pair of symmetrical differential pinions 30 and 30 are provided on the top. Symmetric differential cases 31L and 31R are provided so as to be separable on the left and right sides of the bull gear 28. The inner ends are fixed to the left and right surfaces of the bull gear 28, and the bosses projecting from the sides of the bull gear 28 are provided. The outer ends are externally rotatably mounted on the axles 104L and 104R and supported together with the inner ends of the axles 104L and 104R by bearings 33 provided on the side walls 20a of the left and right case halves 20L and 20R. Yes. In each differential case 31, 31R, a differential side gear 32 fixed to the inner end of each axle 104L, 104R is disposed, and meshes with the differential pinions 30, 30 respectively. Further, a differential lock member 34 is provided on one of the left and right differential cases 31L and 31R (right differential case 31R in this embodiment) so as to be slidable in the axial direction, and the differential side gear 32 disposed in the differential case. By engaging with, it is assumed to be diff-locked.

  An annular flange portion 20b is formed around each of the case half portions 20L and 20R around the left and right side walls 20a centering on the bearing 33, and in the flange portion 20b, the rim of the rear wheel 5 is formed. Instead of the attached brake 5b, for example, a wet multi-plate type brake can be provided on each of the axles 104L and 104R.

  The first axle drive device T1 projects the one of the left and right differential cases 31L and 31R opposite to the side where the CVT 4 is disposed to the outside of the flange portion 20b, and is used for taking out power to the second axle drive device T2. The PTO shaft (power take-off shaft) is used. In this embodiment, the right differential case 31R is used as the PTO axis. That is, the boss portion of the differential case 31R is a hollow shaft 31a extending along the outer periphery of the right axle 104R, and this is used as a PTO shaft to drive the right outer side (CVT4) of the right case half 20R. Projecting to the opposite side of the input shaft 101.

  A PTO case (PTO case) 51 is attached to the outer end of the flange portion 20b of the right case half 20R projecting from the bearing 33 using the differential case 31R as a PTO shaft. Specifically, the PTO case 51 is formed as a case unit by joining the input case portion 51a, the gear case portion 51b, and the output case portion 51c, and the input case portion 51a is a flange portion of the mission case 20 as a spacer. It is interposed between 20b and the gear case part 51b, and is fastened to the flange part 20b through the bolt 35 together with the gear case part 51b. By changing the thickness of the input case 51a, it is possible to select an appropriate position of the output shaft 55 described later in the vehicle width direction.

  The input case 51a and the gear case 51b hold bearings 36 concentrically with the right axle 104R, and the input bevel gear 53 is rotatably supported between the bearings 36 therebetween. The gear 53 is formed with a through hole including a rotation center, and the bearing 33 is installed around the hole with a hollow boss portion 53a protruding in the left-right direction. The right axle 104R is passed through the through hole. To do. The gear case portion 51b is provided with a bearing 37 and a seal member that support the outer end side of the right axle 104R. Thus, the axle 104R also penetrates the gear case portion 51b and is engaged with the rear wheel shaft 5a via the coupling 108 as described above. A female spline is engraved on the inner peripheral surface of the boss portion 53a facing the differential case 31R, while a male spline is engraved on the tip of the hollow shaft 31b extending from the differential case 31R, and inserted into the boss portion. By doing so, the differential case 31R and the input bevel gear 53 are engaged.

  In the output case portion 51c, the output bevel gear 54 and the output shaft 55, which are smaller in diameter than the input bevel gear 53, are arranged in a direction perpendicular to the axle 104R so that the rotation axes of the output bevel gear 53 and the output shaft 55 are directed. Between the bevel gear 54 and the output shaft 55, a drive mode switching clutch 44 capable of engaging and disengaging both members is provided.

  In this embodiment, the output case portion 51c extends forward for driving the front wheels 7, but for power transmission to the drive wheels disposed behind the transmission case 20 and the PTO case 51. The PTO case 51 may be attached to the mission case 20 so as to extend backward, and the direction is not limited in this way.

  The speed increase ratio by the large diameter bevel gear 53 and the small diameter bevel gear 54 is substantially the same as the speed reduction ratio of the reduction gear train formed by the small diameter gear 27 and the bull gear 28 in the transmission case 20, and the rotation speed of the output shaft 55 is The rotational speed is substantially the same as that when the intermediate shaft 102 is driven and connected at a constant speed. Therefore, the intermediate shaft 102 can be used as it is without changing the specifications of the second axle drive device T2 used when the intermediate shaft 102 is configured as a PTO shaft for driving the second axle drive device T2.

  The bevel gear 54 is always meshed with a bevel gear 53 that rotates integrally with the main drive axle 104, and when the clutch 44 is inserted, the output shaft 55 is drivingly connected to the bevel gear 54, and the secondary axle drive device T2 performs a secondary drive. Power is transmitted to the axle 106 to place the vehicle in a four-wheel drive mode. Further, by disengaging the clutch 44, engine power is transmitted only from the main drive axle 104 to the rear wheels 5, and the vehicle is driven in the two-wheel drive mode.

  In the first axle drive device T1, the opening end of the flange portion 20b opposite to the side where the PTO case 51 is attached (in this embodiment, the left case half portion 20L) supports the outer end side of the left axle 104L. It is covered with a side cover 38L provided with a bearing 37 and a seal member. Further, in the case where a so-called two-wheel drive vehicle that is driven by only the main drive wheels by the axles 104L and 104R of the axle drive device T1 is configured, as shown in FIG. The open ends of the flange portions 20b of the half portions 20L and 20R are respectively covered with side covers 38L and 38R including bearings 37 and seal members that support the outer end sides of the axles 104L and 104R. If the joint of the side cover 38R to the flange portion 20b (the size and interval of the mounting bolt) and the joint of the PTO case are made common, the configuration of the case halves 20L and 20R can be changed without any change. It can be changed to a state where the PTO case 51 is attached or not attached.

  When the side cover 38 is attached to both the left and right flange portions 20b, the outer end of the bearing wall 20Ra is replaced by a differential case 31R in which a hollow shaft 31a is integrally formed so as to protrude from the transmission case 20 as a PTO shaft. A differential case 31R ′ shortened to be accommodated in the bearing 33 supported in the above is used. Further, the hollow shaft 31a may be integrally formed with the boss portion of the differential case 31R as shown in the embodiment, or may be connected so as to be separable from each other although not shown. With this configuration, the differential case 31R can be shared by the four-wheel drive specification and the two-wheel drive specification.

  Next, the internal structure of the transaxle case 40 constituting the second axle drive device T2 will be described with reference to FIGS. In the transaxle case 40, the axles 106 and 106 are differentially connected by a differential gear mechanism. The differential gear mechanism includes a differential case 41, a differential pinion shaft 45 supported by the differential case 41, a differential pinion 46 pivotally supported by the differential case 41 via the differential pinion shaft 45, and the differential case 41. Each of the axles 106 includes a differential side gear 47 that is fixed to the inner end of the axle 106 and meshes with the differential pinion 46. Between each of the differential side gears 47 and the differential case 41, a limited is formed by a plurality of spring-biased friction plates. A slip differential mechanism 48 is interposed. By this limited slip differential mechanism 48, each axle 106 is restricted from rotating relative to the differential case 41. As a result, even if one of the left and right front wheels 7 slips into the groove, the driving force is transmitted not only to the front wheel 7 in which it fits but also to the front wheel 7 that does not fit, so that the vehicle can escape from the groove. It has become.

  In order to input power from the PTO case 51, the input shaft 105 is pivotally supported in the front-rear direction and extends rearward from the transaxle case 40. A bevel gear 43 is fixed to the front end of the input shaft 105, and the differential case 41 is attached to the differential case 41. It meshes with the fixed bull gear 42. In this embodiment, the drive mode switching clutch 44 is housed in the PTO case 51. However, this clutch may be provided on the input shaft 105 in the transaxle case 40, for example. .

  Next, a power transmission structure from the first axle drive device T1 to the second axle drive device T2 will be described with reference to FIGS. As described above, the PTO case 51 is attached to the transmission case 20 of the first axle drive device T1 on the opposite side to the CVT 4, and the front end of the output shaft 55 protruding forward from this is the first transmission. Similarly to the above-described coupling 108, the shaft 111 is drivingly connected to the rear end of the shaft 111 via a spline in a sleeve-like coupling 109. The first transmission shaft 111 extends forward in a substantially horizontal shape, and a front end portion thereof is supported by a pillow block 56 erected from the bottom surface of the rear frame 1. The pillow block 56 is preferably disposed at substantially the same position as the front end of the engine E in the front-rear direction, and at a position opposite to the left and right of the engine E with respect to the CVT 4.

  Immediately before the pillow block 56, the front end of the first transmission shaft 111 is drivingly connected to the front second transmission shaft 112 via a universal joint 113. The transmission shaft 112 has a substantially horizontal shape directly below the platform 2b of the front frame 2 and extends in a left-right slanted manner as can be seen in FIG. 2, and has a front end at the housing of the second axle drive device T2. A universal joint 115 is connected to the rear end of the input shaft 105 protruding rearward from 40. In order to reduce vibration and noise by reducing the left-right inclination angle of the second transmission shaft 112 interposed between the first transmission shaft 111 and the input shaft 105 disposed on the right side of the engine E as much as possible, In the second axle drive device T2, the input shaft 105 is disposed slightly to the right of the vehicle left and right center.

  As described above, the four-wheel drive vehicle shown in FIG. 1 and FIG. 2 is on the left and right sides between the engine E arranged at the rear of the vehicle and the transmission case 20 of the first axle drive device T1 arranged behind the engine E. The CVT 4 is provided on the (left side), and the flange 20b that is the support end of the right axle 104R of the transmission case 20 is provided on the opposite side (right side) of the CVT 4 via the engine E and the transmission case 20. A differential case 31R extending along the outer periphery of the right axle 104R is drivingly connected to an output shaft 55 provided with a PTO case 51 and pivotally supported by the PTO case 51. The first transmission shaft 111, the second transmission shaft 112, and the universal gear that are arranged on the right side of the engine E (the opposite side to the CVT 4) are connected to the input shaft 105 of the second axle drive device T2 disposed at the front. With each other to drivingly connected through the cement 113 - 115. Accordingly, the output shaft 55 is positioned at the same level as the lowest axle 104 of the first axle drive device, and is vertically connected to the transmission shaft 112 vertically running below the platform 2b to be lowered to improve the boarding / exiting ability. The amount of offset in the direction can be reduced as much as possible and can be connected in a substantially straight line. As a result, the universal joint 113 has a left-right fold angle in plan view but a very small up-and-down fold angle in side view, which can suppress the noise and vibration generated here and make the vehicle comfortable to ride. Will improve.

  Thus, for example, a six-wheel drive vehicle as shown in FIG. 7 may be configured by using the first axle drive device T1 and the second axle drive device T2 with the PTO case 51 attached to the transmission case 20. Is possible.

  The six-wheel drive vehicle of FIG. 7 has a rear frame through each intermediate vehicle bearing member 11 in front of the left and right rear wheels 5 which are first main drive wheels supported by the rear frame 1 through each rear vehicle bearing member 6. 1, a left and right intermediate wheel 10 that is a second main drive wheel supported by 1 is disposed, and a first axle drive device T1 is disposed between the intermediate wheels 10 and 10, and the intermediate axis that is the central axis of the intermediate wheel 10 is disposed. The wheel shaft 10a is drivingly connected to the left and right axles 104L and 104R supported on the transmission case 20 of the first axle driving device T1 on the same axis via the coupling 108 similar to the above. The rim of each intermediate wheel 10 is provided with a brake 10a such as a drum type or a dry single plate type similar to the brake 5a.

  The engine E is mounted on the rear frame 1 between the rear wheels 5 and 5 at the rear of the first axle drive device T1, and the CVT 4 is connected to the engine E and the transmission on one of the left and right sides (left side in this embodiment). It is interposed between the case 20.

  A PTO case 51 is attached to the right side of the first axle drive device T1 (on the opposite side to the CVT 4) as in FIGS. 1 to 4, and a hollow shaft 31a is integrally formed on the side wall of the differential case 31R to form a PTO shaft. The transmission structure from the PTO case 51 to the second axle drive device T2 for driving the left and right front wheels 7 which are auxiliary drive wheels is the same.

  Power is transmitted from the axles 104L and 104R to the rear wheels 5 and 5 via a chain transmission mechanism. That is, the sprocket 192 is fixed on the coupling 108 between the axles 104L, 104R, and the intermediate wheel shaft 10a, the sprocket 193 is fixed to the inner end of the rear wheel shaft 5a, and both the sprockets 192 and 193 are connected by the chain 191. The left and right chains 191 and sprockets 192 and 193 are covered with a chain case 190 attached to the left and right side plates of the rear frame 1.

  In the first embodiment, the drive mode switching clutch 44 provided on the output case 51c side in the PTO case 51 includes a flange 20b and an input case 51a of the right case half 20R, as shown in FIG. It is also possible to arrange between them. That is, the hollow shaft 31a and the boss portion 53a of the input bevel gear 53 are separated from each other in the axial direction, and a clutch slider having a driving claw portion 44b on the end surface facing the input bevel gear 53 at the tip of the hollow shaft 31a. 44a is disposed so as not to be relatively rotatable and slidable in the axial direction, and a driven claw portion 53b is provided on the end face of the input bevel gear 53 on the side facing the driving claw portion 44b. Reference numeral 44c denotes a clutch operating shaft supported by the input case portion 51a, and is configured so that the clutch slider 44a is slid by the arm 44d to engage and disengage the driving claw portion 44b and the driven claw portion 53b by rotating. ing.

  Further, in the first embodiment, the bearing 33 that supports the hollow shaft 31a held on the side wall 20a of the right case half 20R can also be held on the input case 51 as shown in FIG. That is, a cylindrical part 51d concentric with the right axle 104R is formed to protrude toward the differential case 31R on the input case part 51a joined to the flange part 20b of the right case half part 20R, and the side wall of the right case half part 20R. 20a is provided with an opening 20c through which the cylindrical portion 51d can enter the mission case. Thus, the bearing 33 is held at the tip of the cylindrical portion 51d at substantially the same position as in the first embodiment. By adopting this configuration, the hollow shaft 31a can be thickened, and the shaft strength and the connection strength with the input bevel gear 53 can be improved. In the case of the two-wheel drive specification, it is only necessary to provide a cylindrical portion for supporting the same bearing 33 in the side cover 38R shown in FIG.

  The vehicle transmission device of the present invention can be applied to various vehicles having a plurality of drive wheels arranged side by side, such as a four-wheel drive and a six-wheel drive, in addition to the transport vehicle mentioned in the recommended example. This is advantageous in promoting standardization of the device.

1 is a schematic side view of a four-wheel drive transport vehicle according to a first embodiment of the present invention. Fig. 2 is a schematic plan view of the transport vehicle of Fig. 1. A rear sectional view of the transmission case 20 of the first axle drive device T1, a rear sectional view of the bearing support member 6 that supports the rear axle 5a connected to the axle 104R supported by the transmission case 20, and an attachment to the transmission case 20. 2 is a cross-sectional plan view of a PTO case 51. FIG. 3 is an enlarged plan sectional view of a PTO case 51. FIG. FIG. 6 is a rear cross-sectional view of the transmission case 20 of the first axle drive device T1 when no PTO case 51 is provided. It is a top sectional view of transaxle case 40 of the 2nd axle drive unit T2. It is a top sectional view of the six-wheel drive transport vehicle according to the second embodiment of the present invention. 4 is an enlarged plan cross-sectional view of a PTO case 51 in which a layout of a drive mode switching clutch 44 is changed. FIG. It is an expanded plane sectional view of PTO case 51 which changed the support shape of hollow shaft 31a.

Explanation of symbols

E engine (motor)
T1 1st axle drive device T2 2nd axle drive device 4 Belt transmission device 5 Rear wheel 6 Rear wheel bearing support member 7 Front wheel 10 Intermediate wheel 20 Transmission case 20L Left case half 20R Right case half 20b Flange (Axle support edge)
27 ・ 28 Reduction gear train in the transmission case 20 31L ・ 31R Differential case 31a Hollow shaft (PTO shaft)
38L / 38R Side cover 51 Power take-off case (PTO case)
53/54 Bevel gear (speed-up gear train in the PTO case 51)
104L and 104R First axle 105 (of the first axle drive device T1) Input shaft 106 (of the second axle drive device T2) 106 Second axle (of the second axle drive device T2) 111 First transmission shaft 112 Second transmission shaft 113 Universal joint (transmission direction converter)
115 Universal joint (transmission terminal)

Claims (6)

  A mission case that supports the main drive axle to the left and right is disposed in front of or behind the prime mover in the vehicle, and the prime mover and the axle drive mechanism in the mission case are connected to drive on the left and right sides of the mission case. A belt transmission device is provided, and a PTO case for driving the auxiliary drive axle is attached to the support end portion of the main drive axle on the opposite side of the transmission case to the belt transmission device. An axle drive device for a four-wheel drive vehicle.   The axle drive mechanism in the transmission case includes a differential gear mechanism that differentially connects the pair of left and right main drive axles, and extends to the differential case of the differential gear mechanism along the outer periphery of the main drive axle. The four-wheeled vehicle according to claim 1, wherein a hollow shaft is provided in a driving manner to be used as a power take-out shaft, and is inserted into the PTO case and is connected to a power take-out mechanism in the PTO case. Axle drive device for driving vehicle.   In the transmission case, a transmission shaft on the upper side of the differential gear mechanism is pivotally supported and connected to the differential gear mechanism via a deceleration drive train, and the protruding end portion of the differential case is in the PTO case. The speed-up ratio of the drive train in the PTO case is substantially the same as the speed reduction ratio of the speed-down drive train in the transmission case. The axle drive device for a four-wheel drive vehicle according to claim 2, wherein the speed increasing ratio is set.   The cover member that covers the shaft support end portion of each drive axle on the left and right sides in the transmission case that supports the main drive axle to the left and right can be replaced with a PTO case for driving the sub drive axle. Axle drive device for wheel drive vehicle.   A differential gear mechanism that differentially connects the pair of left and right main drive axles is housed in the transmission case, and a hollow shaft that extends along the outer periphery of the main drive axle to the differential case of the differential gear mechanism. 5. A four-wheel drive vehicle according to claim 4, wherein said four-wheel drive vehicle is provided as a power take-off shaft, is made to enter into said PTO case, and is drive-connected to a power take-out mechanism in said PTO case. Axle drive system for   In the transmission case, a transmission shaft on the upper side of the differential gear mechanism is pivotally supported and connected to the differential gear mechanism via a deceleration drive train, and the protruding end portion of the differential case is in the PTO case. The speed-up ratio of the drive train in the PTO case is substantially the same as the speed reduction ratio of the speed-down drive train in the transmission case. 5. The axle drive device for a four-wheel drive vehicle according to claim 4, wherein the speed increasing ratio is set.

Images