JP7759840B2 - Multipurpose vehicle - Google Patents

Description

The present invention relates to a multipurpose vehicle in which a power unit including an engine and a transmission is supported on a frame unit.

In the multipurpose vehicle disclosed in Patent Document 1, a power unit consisting of an engine, a transmission, and a belt-type continuously variable transmission located on either the left or right side of the engine and transmission for transmitting engine power to the transmission is supported by a rear frame that forms the rear of the main frame. The rear frame has left and right side members and multiple cross members connecting the left and right side members. Left and right rear suspensions that support the left and right rear wheels are provided at the rear of the rear frame.

Patent Document 2 discloses a monocoque-type floor structure. The floor structure includes a floor panel, left and right side sills as side members joined to both sides of the floor panel, and a cross member positioned between the left and right side sills. Furthermore, at the corners formed by the side sills and cross member, reinforcing members are attached obliquely to the side sills and cross member.

Japanese Patent Application Laid-Open No. 2017-013691 Japanese Patent Application Laid-Open No. 2006-297966

The side members of the multi-purpose vehicle described in Patent Document 1 are subjected to impact forces (loads and vibrations) from uneven road surfaces via the rear suspension. When this impact force is transmitted to the cross members and pillars, the entire vehicle body deforms, resulting in poor handling stability and a poor ride. To solve this problem, adding reinforcing members is one option, as disclosed in Patent Document 2. Other options include increasing the cross-section of the material used for the side members and cross members, adding reinforcing members, or increasing the thickness of the panels. However, these solutions result in problems such as increased vehicle weight, increased costs, and reduced passenger space.

In light of the above situation, the object of the present invention is to provide a multipurpose vehicle that suppresses deterioration in handling stability and ride comfort when traveling on uneven roads, without increasing vehicle weight or reducing passenger space.

A multipurpose vehicle according to the present invention comprises a power unit including an engine and a transmission, a pair of left and right rear wheels, a frame unit including a pair of left and right main side members and a cross member connected to the main side members, a rear suspension supporting the rear wheels, a front post unit fixed to the frame unit forward of the rear wheel axle in the longitudinal direction of the vehicle body, a rear post unit fixed to the frame unit rear of the rear wheel axle in the longitudinal direction of the vehicle body, and mount units attached to the front post unit and the rear post unit so as to mount the power unit at a position higher than the rear wheel axle located above the frame unit , wherein the front post unit comprises a left front support part and a right front support part arranged at a distance from each other in the transverse direction of the vehicle body, the rear post unit comprises a central rear support part arranged in a central region in the transverse direction of the vehicle body, and the mount unit comprises a left front mount supported by the left front support part, a right front mount supported by the right front support part, and a central rear mount supported by the central rear support part.

In this configuration, the power unit is supported by the front and rear post units via mount units at a position higher than the rear wheel axle, which is higher than the frame unit consisting of the side members and cross members. In other words, the power unit mounting surface defined by the mount units (mounting points) attached to the front and rear post units is located above the frame surface defined by the frame unit. This expands the space between the power unit mounting surface and the frame surface, allowing for the placement of the power unit's core. Furthermore, because the power unit has high rigidity, the three-dimensional structure created by the frame unit positioned on the frame surface, the power unit positioned on the power unit mounting surface, and the front and rear post units connecting the frame unit and power unit strengthens the vehicle structure supporting the rear wheels. As a result, deterioration of handling stability and ride comfort when driving on uneven roads is suppressed, with little increase in vehicle weight or compression of passenger space.

If the power unit mounting surface defined by the mount units (mounting points) attached to the front and rear post units becomes larger, the space available for arranging components other than the power unit will be reduced. Therefore, a suitable solution for achieving both a smaller power unit mounting surface and stable support for the mount unit is to make the power unit mounting surface substantially triangular, i.e., to support the power unit substantially at three mounting points. Therefore, in one embodiment of the present invention, the front post unit comprises a left front support unit and a right front support unit spaced apart in the transverse direction of the vehicle body, the rear post unit comprises a central rear support unit disposed in the central region in the transverse direction of the vehicle body, and the mounting units comprise a left front mount (left mounting point) supported by the left front support unit, a right front mount (right mounting point) supported by the right front support unit, and a central rear mount (central mounting point) supported by the central rear support unit.

In a power unit, the engine requires a larger vertical space than the transmission. In one embodiment of the present invention, where the engine is positioned closer to the center of the vehicle body, the left front mount and the right front mount are positioned higher than the central rear mount. In this configuration, the front space between the power unit mounting surface and the frame surface is larger than the rear space between the power unit mounting surface and the frame surface, providing a space suitable for arranging the main parts of the engine.

The multipurpose vehicle according to the present invention comprises a power unit including an engine and a transmission, a pair of left and right rear wheels, a frame unit including a pair of left and right main side members and a cross member connected to the main side members, a rear suspension supporting the rear wheels, a front post unit fixed to the frame unit forward of the rear wheel axle in the longitudinal direction of the vehicle body, a rear post unit fixed to the frame unit rear of the rear wheel axle in the longitudinal direction of the vehicle body, and mount units attached to the front post unit and the rear post unit so as to mount the power unit at a position higher than the rear wheel axle located above the frame unit, wherein the front post unit comprises a central front post arranged in a central region in the transverse direction of the vehicle body, and the rear post unit comprises a left rear post and a right rear post arranged at a distance from each other in the transverse direction of the vehicle body, and the mount unit comprises a central front mount supported by the central front post, a left rear mount supported by the left rear post, and a right rear mount supported by the right rear post.
In this configuration, the power unit is supported by the front and rear post units via mount units at a position higher than the rear wheel axles, which is higher than the frame unit consisting of the side members and cross members. In other words, the power unit mounting surface defined by the mount units (mounting points) attached to the front and rear post units is located above the frame surface defined by the frame unit. This allows the expanded space between the power unit mounting surface and the frame surface to be used as a placement space for the core of the power unit. Furthermore, because the power unit has high rigidity, the three-dimensional structure created by the frame unit positioned on the frame surface, the power unit positioned on the power unit mounting surface, and the front and rear post units connecting the frame unit and the power unit strengthens the vehicle structure supporting the rear wheels. As a result, deterioration of handling stability and ride comfort when traveling on uneven roads is suppressed without significantly increasing vehicle weight or reducing passenger space.
In another embodiment of the present invention for supporting a power unit at three mounting points, the front post unit comprises a central front post unit arranged in a central region in the transverse direction of the vehicle body, the rear post units comprise a left rear post unit and a right rear post unit arranged at a distance from each other in the transverse direction of the vehicle body, and the mount units comprise a central front mount supported by the central front post unit, a left rear mount supported by the left rear post unit, and a right rear mount supported by the right rear post unit. This configuration is suitable for when the engine is disposed in the rear of the vehicle body. In this case, if the central front mount is positioned higher than the left rear mount and the right rear mount, the rear space between the power unit mounting surface and the frame surface becomes larger than the front space between the power unit mounting surface and the frame surface, providing a space suitable for disposing the main components of the engine.
Since the power unit is disposed near the rear suspension, various structural constraints arise in order to avoid interference between the power unit and the rear suspension. This problem can be at least partially solved by positioning the power unit above the rear suspension. For this reason, in one embodiment of the present invention, the power unit is mounted by the mount unit at a position higher than the rear suspension.

1 is a side view illustrating a first basic concept of the present invention in a multipurpose vehicle in which the engine is disposed toward the center of the vehicle body. 1 is a bottom view illustrating a first basic concept of the present invention in a multipurpose vehicle in which the engine is disposed toward the center of the vehicle body. FIG. FIG. 10 is a side view illustrating the second basic concept of the present invention in a multipurpose vehicle in which the engine is disposed at the rear of the vehicle body. FIG. 10 is a bottom view illustrating the second basic concept of the present invention in a multipurpose vehicle in which the engine is disposed at the rear of the vehicle body. FIG. 1 is a side view of one embodiment of a utility vehicle. FIG. 6 is a plan view of the utility vehicle shown in FIG. 5 . 1 is a schematic diagram showing a powertrain of a utility vehicle; FIG. 2 is a side view showing the positional relationship between the engine, the transmission, and the frame unit. FIG. FIG. 4 is a rear view showing the rear post unit.

In this specification, unless otherwise specified, "front" means forward in the longitudinal direction (travel direction) of the aircraft, and "rear" means rearward in the longitudinal direction (travel direction) of the aircraft. Furthermore, left-right or lateral direction means the transverse direction (width direction) of the aircraft, which is perpendicular to the longitudinal direction of the aircraft. "Above" or "below" refers to the positional relationship in the vertical direction (perpendicular direction) of the aircraft, and indicates the relationship in terms of height above ground.

Before describing specific embodiments of the multi-purpose vehicle according to the present invention, the basic concept of the present invention, relating to the frame structure FS that supports the power unit of the multi-purpose vehicle, will be explained using Figures 1 to 4. The power unit is a major component of the vehicle's powertrain and will be explained in detail using Figures 5, 6, and 7. Figures 1 (side view) and 2 (bottom view) show the frame structure FS of a multi-purpose vehicle equipped with a power unit whose engine is located toward the center of the vehicle body, while Figures 3 (side view) and 4 (bottom view) show the frame structure FS of a multi-purpose vehicle equipped with a power unit whose engine is located at the rear of the vehicle body. In Figures 1 to 4, the mounting points where the power unit is mounted are indicated by black circles.

The frame structure FS comprises a pair of left and right main side members 1, multiple cross members 2 connecting the left and right main side members 1, and upper side members 3 extending in the longitudinal direction of the aircraft above the rear of the main side members 1. The main side members 1 consist of a front side member 1f and a rear side member 1r.

The first basic concept shown in Figures 1 and 2 shows three mounting points where the power unit is mounted. As shown in Figure 2, these three mounting points are the left front mounting point LFMP, located above the front end peripheral region of the left rear side member 1r; the right rear mounting point RRMP, located above the front end peripheral region of the right rear side member 1r; and the central rear mounting point CRMP, located above the center between the rear end peripheral regions of the left and right rear side members 1r. The left front mounting point LFMP and the right front mounting point RFMP are substantially the same height above ground, and the left front mounting point LFMP and the right front mounting point RFMP are higher above ground than the central rear mounting point CRMP. The main components of the power unit are positioned in the space between the triangle (referred to as the power unit mounting surface) whose vertices are the right front mounting point RFMP, the left front mounting point LFMP, and the central rear mounting point CRMP, and the area (referred to as the frame surface) defined by the left and right rear side members 1r.

The second basic concept shown in Figures 3 and 4 shows three mounting points where the power unit is mounted. As shown in Figure 4, these three mounting points are the left rear mounting point LRMP, located above the rear end peripheral region of the left rear side member 1r; the right rear mounting point RRMP, located above the rear end peripheral region of the right rear side member 1r; and the center front mounting point CFMP, located above the center between the front end peripheral regions of the left and right rear side members 1r. The left rear mounting point LRMP and the right rear mounting point RRMP are substantially the same height above the ground, and the center front mounting point CFMP is higher than the left rear mounting point LRMP and the right rear mounting point RRMP. The main parts of the power unit are located in the space between the triangle (power unit mounting surface) whose vertices are the center front mounting point CFMP, left rear mounting point LRMP, and right rear mounting point RRMP, and the area (referred to as the frame surface) defined by the left and right rear side members 1r.

Whether it is the first or second basic concept, the highly rigid power unit is mounted at three mounting points above the rear side member 1r, allowing the power unit itself to function as a stiffening member in the frame structure FS at the rear of the vehicle body.

Next, we will explain one specific embodiment of a multi-purpose vehicle according to the present invention. Figure 5 is a side view of the multi-purpose vehicle, and Figure 6 is a plan view. This embodiment of the multi-purpose vehicle employs the first basic concept of the present invention described above.

This multipurpose vehicle is equipped with a pair of left and right front wheels 11 as drivable and steerable running devices, and a pair of left and right rear wheels 12 as drivable running devices. The running body of the multipurpose vehicle is configured to run on the pair of left and right front wheels 11 and the pair of left and right rear wheels 12. The front wheels 11 and rear wheels 12 are supported by main side members 1 reinforced by cross members 2. A driver's seat 13 is provided in the center of the running body to operate the vehicle. A loading platform 14 on which cargo can be loaded is provided at the rear of the running body. A power unit 15 is provided below the loading platform 14 on the running body.

A frame unit is made up of a pair of left and right main side members 1 and a cross member 2 that connects the pair of left and right main side members 1. The pair of left and right main side members 1 includes a front side member 1f and a rear side member 1r. An upper side member 3 and a rear side member 1r are positioned above the rear side member 1r. The pair of left and right rear side members 1r, upper side member 3, and rear side member 1r are reinforced by the cross member 2.

The driver's section 13 is surrounded and protected by a frame-shaped rope frame 16. The driver's section 13 is equipped with a driver's seat 17 where the operator sits. The driver's section 13 also is equipped with controls operated by the driver, such as a steering wheel 18, a gear change control, an accelerator pedal, a brake pedal, and a parking lever.

Figure 7 shows the power unit 15 that makes up the powertrain of this multi-purpose vehicle. The power unit 15 includes a water-cooled gasoline engine (an example of an "engine"; hereafter abbreviated as engine 23), a belt-type continuously variable transmission 29, and a transmission 24, which is a gear transmission. The power from the engine 23 is speed-shifted by the belt-type continuously variable transmission 29 and the transmission 24, and transmitted to the driving device.

The engine 23 is positioned with its crankshaft facing sideways to the aircraft body. The engine 23 is equipped with a main output shaft 25 that is integral with the crankshaft, and an auxiliary output shaft 26 that is also integral with the crankshaft. The output of the main output shaft 25 is input to a belt-type continuously variable transmission mechanism 29. The output of the auxiliary output shaft 26 drives a generator 28 composed of an alternator or the like.

The transmission 24, which receives the output of the belt-type continuously variable transmission 29, is equipped with a gear-type transmission 30, a rear wheel differential mechanism 31 capable of creating a speed difference between the left and right rear wheels 12, and a front wheel differential mechanism 32 capable of creating a speed difference between the left and right front wheels 11. The rear wheel differential mechanism 31 outputs power input from a final gear 41 to the rear wheel axles of the left and right rear wheels 12 via rear wheel drive shafts 43 extending in the left-right direction of the vehicle. The gear-type transmission 30 changes the speed of the power input from the belt-type continuously variable transmission 29 and outputs it to the final gear 41, which is interlocked with the rear wheels 12, and the power takeoff shaft 42, which is interlocked with the front wheels 11. The transmission 24 is covered by a transmission case 33, which is connected to the engine 23 and the belt-type continuously variable transmission 29. In particular, the engine 23 and transmission 24 form a single, highly rigid structure.

As shown in Figure 8, a pair of left and right front post units 5 and rear post units 6 are provided to connect the lower frame unit formed by the rear side member 1r and cross member 2 to the upper frame unit formed by the upper side member 3 and cross member 2.

As is clear from Figure 9, the front post unit 5 is located in the front region of the frame unit in the vehicle's fore-and-aft direction, and consists of a left front side post 51, a right front side post 52, a left front support portion 53, and a right front support portion 54. The left front side post 51 is connected and fixed to the left rear side member 1r and the upper side member 3, and the right front side post 52 is connected and fixed to the right rear side member 1r and the upper side member 3. The left front support portion 53 and the right front support portion 54 are fixed to the cross member 2 connecting the front regions of the left and right rear side members 1r between the left front side post 51 and the right front side post 52. The left front support portion 53 and the right front support portion 54 are spaced apart from each other in the transverse direction of the vehicle.

As is clear from Figure 10, the rear post unit 6 is located in the rear region of the frame unit in the vehicle body longitudinal direction, and consists of a left rear side post 61 and a right rear side post 62. The left rear side post 61 is connected and fixed to the left rear side member 1r and the upper side member 3, and the right rear side post 62 is connected and fixed to the right rear side member 1r and the upper side member 3. The left rear side post 61 and the right rear side post 62 each support a part of the rear suspension 70 (see Figure 8). The rear suspension 70 is of a double wishbone type and supports the left and right rear wheels 12.

The rear post unit 6 further includes a central rear support portion 63. The central rear support portion 63 is configured as a support base having a left leg portion 63a and a right leg portion 63b, with the left leg portion 63a connected and fixed to the left rear side post 61 and the right leg portion 63b connected and fixed to the right rear side post 62. As a result, the central rear support portion 63 is located approximately midway between the cross member 2 connecting the rear regions of the left and right rear side members 1r and the cross member 2 connecting the rear regions of the left and right upper side members 3.

8, 9, and 10, the mount unit 8 that mounts the power unit 15 consists of a left front mount 81 supported on the tip region of the left front support part 53, a right front mount 82 supported on the tip region of the right front support part 54, and a central rear mount 83 supported on the tip region of the central rear support part 63. The left front mount 81, right front mount 82, and central rear mount 83 respectively form the left front mount point LFMP, right front mount point RFMP, and central rear mount point CRMP shown in FIG. 2. Therefore, the power unit 15 mounted by this mount unit 8 is positioned in a space higher than the axle of the rear wheel 12. As is clear from FIG. 8, in this embodiment, the power unit 15 is positioned higher than the rear suspension 70. Furthermore, the left front mount 81 and right front mount 82 are positioned higher than the central rear mount 83. Since the engine 23 requires a large amount of space in the height direction to occupy the front half of the power unit 15, this type of space for arranging the power unit 15 makes it easier to position the engine 23.

The configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, provided that no contradictions arise. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these embodiments. They can be modified as appropriate within the scope of the purpose of the present invention.

[Another embodiment]
(1) The above-described embodiment using FIGS. 5 to 10 employs the first basic concept of the present invention described with reference to FIGS. 1 and 2. Alternatively, another embodiment employing the second basic concept of the present invention described with reference to FIGS. 3 and 4 may be implemented. In such an embodiment, the front half of the power unit 15 is configured as the transmission 24, and the rear half of the power unit 15 is configured as the engine 23. The center front mounting point CFMP, the left rear mounting point LRMP, and the right rear mounting point RRMP shown in FIG. 4 are formed by a center front mount, a left rear mount, and a right rear mount, respectively. The center front mount is supported by a center front post disposed in a central region in the transverse direction of the vehicle body, and the left rear post and the right rear post are supported by left rear posts and right rear posts disposed at a distance from each other in the transverse direction of the vehicle body, respectively. In this alternative embodiment, the center front mount is positioned higher than the left rear mount and the right rear mount.

(2) In the above-described embodiment, the power unit 15 is essentially composed of the engine 23, the belt-type continuously variable transmission mechanism 29, and the transmission 24. However, a hydraulic continuously variable transmission mechanism may be used instead of the belt-type continuously variable transmission mechanism 29, and a gear-type stepped transmission mechanism may be used instead of the continuously variable transmission mechanism.

(3) The engine 23 may be a diesel specification equipped with a diesel engine. Furthermore, it may be a hybrid specification equipped with the engine 23 and an electric motor for driving, or an electric specification in which the engine 23 itself is an electric motor.

(4) In the above-described embodiment, the traveling device was a four-wheel type, but it may also be a three-wheel type.

The present invention is applicable to multipurpose vehicles in which a power unit including an engine and a transmission is supported on a frame unit.

1: Main side member 1f: Front side member 1r: Rear side member 2: Cross member 3: Upper side member 5: Front post unit 6: Rear post unit 8: Mount unit 12: Rear wheel 23: Engine 24: Transmission 27: Engine 51: Left front side post 52: Right front side post 53: Left front support portion 54: Right front support portion 61: Left rear side post 62: Right rear side post 63: Central rear support portion 70: Rear suspension 81: Left front mount 82: Right front mount 83: Central rear mount CFMP: Central front mounting point CRMP: Central rear mounting point FS: Frame structure LFMP: Left front mounting point LRMP: Left rear mounting point RFMP: Right front mounting point RRMP: Right rear mounting point

Claims (5)

a power unit including an engine and a transmission;
A pair of rear wheels,
a frame unit including a pair of left and right main side members and a cross member connected to the main side members;
a rear suspension supporting the rear wheels;
a front post unit fixed to the frame unit forward of the rear wheel axle in the vehicle front-rear direction;
a rear post unit fixed to the frame unit rearward of the rear wheel axle in the vehicle front-rear direction;
a mount unit attached to the front post unit and the rear post unit so as to mount the power unit at a position higher than the rear wheel axle located above the frame unit ,
A multipurpose vehicle, wherein the front post unit comprises a left front support portion and a right front support portion spaced apart from each other in the transverse direction of the vehicle body, the rear post unit comprises a central rear support portion arranged in the central region in the transverse direction of the vehicle body, and the mount unit comprises a left front mount supported by the left front support portion, a right front mount supported by the right front support portion, and a central rear mount supported by the central rear support portion . 2. The utility vehicle of claim 1 , wherein the left front mount and the right front mount are positioned higher than the center rear mount. a power unit including an engine and a transmission;
A pair of rear wheels,
a frame unit including a pair of left and right main side members and a cross member connected to the main side members;
a rear suspension supporting the rear wheels;
a front post unit fixed to the frame unit forward of the rear wheel axle in the vehicle front-rear direction;
a rear post unit fixed to the frame unit rearward of the rear wheel axle in the vehicle front-rear direction;
a mount unit attached to the front post unit and the rear post unit so as to mount the power unit at a position higher than the rear wheel axle located above the frame unit ,
A multipurpose vehicle, wherein the front post unit comprises a central front post arranged in a central region in the transverse direction of the vehicle body, the rear post unit comprises a left rear post and a right rear post arranged at a distance from each other in the transverse direction of the vehicle body, and the mount unit comprises a central front mount supported on the central front post, a left rear mount supported on the left rear post, and a right rear mount supported on the right rear post . 4. The utility vehicle of claim 3 , wherein the center front mount is positioned higher than the left rear mount and the right rear mount. 5. The multi-purpose vehicle according to claim 1, wherein the power unit is mounted by the mount unit at a position higher than the rear suspension.