JP7410237B2 - work vehicle - Google Patents

Description

The present invention relates to a work vehicle.

In a work vehicle, a wheel support member that supports a pair of left and right running wheels, a link mechanism that is provided across the vehicle body and the wheel support member and that supports the wheel support member in a vertically movable manner, and a suspension support portion formed on the vehicle body. and a wheel support member, the suspension mechanism is connected to the vehicle body side support portion formed on the vehicle body and the wheel side support portion formed on the wheel support member, and is connected to the vehicle body side support portion formed on the vehicle body and the wheel side support portion formed on the wheel support member. Some are equipped with a lateral link that restricts the left and right movement of the member.

As this type of work vehicle, there is a work vehicle shown in Patent Document 1, for example. This work vehicle is equipped with a pair of left and right auxiliary frames and a rear axle case as wheel support members, an upper arm and a lower arm as a link mechanism, a suspension unit as a suspension mechanism, and a lateral support frame as a lateral link. A rod is provided.

Japanese Patent Application Publication No. 2012-51506

In the above-mentioned work vehicle, the front end of the link mechanism is supported by the link support part formed on the vehicle body so as to be able to swing up and down around the upper pivot axis, and the rear end part is supported by the wheel support member around the upper connection axis. The upper link is connected to the upper link so as to be swingable relative to the wheel support member, the front end is supported by the link support part so as to be swingable up and down about the lower pivot axis, and the rear end is supported to the wheel support member so as to be able to swing relative to the lower link axis. A lower link that is swingably connected is provided.

There is a demand for this type of work vehicle that is equipped with a link mechanism in a rational manner.

The present invention provides a work vehicle that can be rationally equipped with a link mechanism.

The work vehicle according to the present invention includes:
A wheel support member that supports a pair of left and right running wheels, a link mechanism that is provided across a vehicle body and the wheel support member and that supports the wheel support member in a vertically movable manner, and a suspension support portion formed on the vehicle body. a suspension mechanism that is provided across the wheel support member and elastically supports the wheel support member; and a suspension mechanism that is connected to a vehicle body side support portion formed on the vehicle body and a wheel side support portion formed on the wheel support member. , a lateral link that restricts left and right movement of the wheel support member, and the link mechanism is supported by a link support portion formed on the vehicle body such that the front end thereof can swing vertically around an upper pivot axis. an upper link whose rear end is connected to the wheel support member so as to be relatively swingable about the upper connection axis, and whose front end is supported by the link support part so as to be swingable up and down about the lower pivot axis. and a lower link whose rear end portion is connected to the wheel support member so as to be relatively swingable about the lower connection axis, and the upper link has an intermediate portion located below the front portion and the rear portion. The lower link is formed in a curved shape such that the intermediate portion of the lower link protrudes laterally outwardly so as to avoid the intermediate portion of the upper link laterally outwardly, and the lower link is formed in a curved shape such that the intermediate portion of the lower link extends laterally outwardly, and The upper link passes along the lateral side of the engine in the longitudinal direction of the vehicle body, and the intermediate portion of the upper link avoids downwardly an engine accessory device provided on the lateral side of the engine.

In the present invention, it is preferable that the engine accessory device is an alternator cover.

This is the left side showing the entire multi-purpose work vehicle. FIG. 3 is a left side view showing a rear wheel suspension system. FIG. 3 is a right side view showing a rear wheel suspension system. FIG. 3 is a plan view showing a rear wheel suspension system. FIG. 3 is a rear view showing a rear wheel suspension system. FIG. 3 is a left side view showing the left link mechanism. FIG. 3 is a right side view showing the right link mechanism. FIG. 3 is a sectional view showing the support structure of the left upper link. It is a sectional view showing the support structure of the left lower link. It is a perspective view which shows a wheel side support part and a stopper member. It is a side view which shows a wheel side support part.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment which is an example of this invention is described based on drawing.
In the following explanation, regarding the traveling vehicle body of a multi-purpose work vehicle, the direction of arrow F shown in FIG. The direction of arrow D is defined as "vehicle body downward", the direction on the front side of the paper is "vehicle body left", and the direction on the paper back is "vehicle body right".

[Overall configuration of multi-purpose work vehicle]
As shown in FIG. 1, the multipurpose work vehicle includes a traveling vehicle body equipped with a pair of left and right front wheels 1 that are steerable and drivable, and a pair of left and right rear wheels 2 that are drivable. A driving section 5 having a driver's seat 3 and a steering wheel 4 for steering the front wheels 1 is formed at the front of the traveling vehicle body. The driving section 5 is equipped with a rope 6 that covers the passenger space. A loading platform 7 is provided at the rear of the traveling vehicle body. A driving unit 9 having an engine 8 is formed below the loading platform 7.

[About the configuration of the rear wheel suspension system]
FIG. 2 is a left side view showing the suspension system 10 for the rear wheel 2. As shown in FIG. FIG. 3 is a right side view showing the suspension system 10 for the rear wheel 2. As shown in FIG. FIG. 4 is a plan view showing the suspension system 10 for the rear wheel 2. As shown in FIG. FIG. 5 is a rear view showing the suspension system 10 for the rear wheel 2. As shown in FIG.

As shown in FIGS. 2 to 5, the suspension system 10 for the rear wheels 2 includes a wheel support member 11 that supports a pair of left and right rear wheels 2, and a vehicle body frame 12 that supports the wheel support member 11 so as to be movable up and down. a pair of left and right link mechanisms 20 that enable the left and right rear wheels 2 to move up and down with respect to the vehicle body frame 12; a suspension mechanism 30 that enables elastic support of the left and right rear wheels 2 by elastically supporting the wheel support member 11; A lateral link 40 that restricts the left and right movement of the wheel support member 11 is provided.

As shown in FIGS. 2, 4, and 6, the wheel support member 11 includes a support frame portion 11a and a mounting table portion 11b provided on the upper portion of the support frame portion 11a. A transmission 13 to which the power of the engine 8 is input is supported at the center of the wheel support member 11 in the lateral direction. The engine 8 is connected to a transmission 13 and supported by the wheel support member 11 via the transmission 13.

As shown in FIGS. 2, 3, and 4, the left rear axle 14 extends laterally to the left from the transmission 13. A right rear axle 14 extends laterally to the right from the transmission 13. A left rear axle case 15 that rotatably supports the left rear axle 14 and a right rear axle case 15 that rotatably supports the right rear axle 14 are located on the left and right sides of the mounting table 11b. They are distributed and placed. The left and right rear axle cases 15 are fixed to the mounting base 11b by case holders 16 that are wrapped around the outer periphery of the rear axle case 15 and fixed to the mounting base 11b with connecting bolts. The left and right rear wheels 2 are supported by a wheel support member 11 via a rear axle 14 and a transmission 13. That is, the left and right rear wheels 2 are supported by the wheel support member 11 in a state where no relative displacement occurs between the left and right rear wheels 2. In this embodiment, the engine 8 and the transmission 13 are supported by the wheel support member 11 together with the rear wheel 2, but the invention is not limited thereto. For example, the transmission 13 may be supported by the wheel support member 11 together with the left and right rear wheels 2, and the engine 8 may not be supported by the wheel support member 11. Alternatively, only the left and right rear wheels 2 may be supported by the wheel support member 11, and the engine 8 and the transmission 13 may not be supported by the wheel support member 11.

As shown in FIGS. 2, 3, and 4, the left and right link mechanisms 20 have an upper link 21 extending in the longitudinal direction of the vehicle body, and a lower link 22 extending in the longitudinal direction of the vehicle body.

The front end portion of the upper link 21 is supported by a link support portion 23 on the vehicle body side formed in the vehicle body frame 12 so as to be swingable around an upper pivot axis P1 extending in the width direction of the vehicle body.
Specifically, an upper front boss portion 21a formed at the front end of the upper link 21 and a link support portion 23 are connected via an upper pivot shaft 24 fitted inside the upper front boss portion 21a. . The upper pivot shaft 24 has an upper pivot shaft core P1. The rear end portion of the upper link 21 is supported by a wheel-side link connecting portion 25 formed at a lateral end portion of the wheel support member 11 so as to be swingable around an upper connecting axis P2 extending in the vehicle width direction. Specifically, an upper rear boss portion 21b formed at the rear end of the upper link 21 and a link connecting portion 25 are connected via an upper connecting shaft 26 fitted inside the upper rear boss portion 21b. . The upper connection shaft 26 has an upper connection axis P2.

The front end portion of the lower link 22 is swingably supported at a portion of the link support portion 23 below a portion to which the upper link 21 is connected about a lower pivot axis P3 extending in the vehicle width direction. Specifically, a lower front boss portion 22a formed at the front end of the lower link 22 and a link support portion 23 are connected via a lower pivot shaft 27 fitted inside the lower front boss portion 22a. . The lower pivot shaft 27 has a lower pivot shaft core P3. The rear end portion of the lower link 22 is swingably supported at a portion of the link connecting portion 25 below the portion to which the upper link 21 connects about a lower connecting axis P4 extending in the vehicle width direction. Specifically, a lower rear boss portion 22b formed at the rear end of the lower link 22 and a link connecting portion 25 are connected via a lower connecting shaft 28 fitted inside the lower rear boss portion 22b. There is. The lower connection shaft 28 has a lower connection axis P4.

In the left link mechanism 20, as shown in FIGS. 8 and 9, there are connections between the upper link 21 and the link support part 23, between the lower link 22 and the link support part 23, and between the upper link 21 and the link connection part 25. An elastic member 29 is interposed between the lower link 22 and the link connecting portion 25. Between the upper link 21 and the link support part 23, between the lower link 22 and the link support part 23, between the upper link 21 and the link connection part 25, and between the lower link 22 and the link connection part 25, respectively. When a twist is about to occur, the elastic member 29 is elastically deformed, and this elastic deformation eliminates the twist. Similarly to the left link mechanism 20, the right link mechanism 20 is also provided with an elastic member 29.
In this embodiment, the elastic member 29 has a cylindrical shape that fits internally into the upper front boss portion 21 a and externally fits onto the upper pivot shaft 24 , and has a cylindrical shape that fits internally into the lower front boss portion 22 a and externally fits onto the lower pivot shaft 27 . A cylindrical shape that fits inside the upper rear boss portion 21b and an outside fit on the upper connecting shaft 26, and a cylindrical shape that fits inside the lower rear boss portion 22b and fits outside the lower connecting shaft 28. However, it is not limited to this. For example, the elastic member is provided between the upper pivot shaft 24 and the link support section 23, between the lower pivot shaft 27 and the link support section 23, between the upper connection shaft 26 and the link connection section 25, and between the lower connection shaft It may be interposed between 28 and the link connecting portion 25.

In the left and right link mechanisms 20, as shown in FIGS. 6 and 7, the distance between the upper pivot axis P1 and the upper connection axis P2 is UL, and the distance between the lower pivot axis P3 and the lower connection axis P4 is The distance between them is DL, the width of the gap between the upper pivot axis P1 and the lower pivot axis P3 is FD, and the width of the gap between the upper connection axis P2 and the lower connection axis P4 is Let it be RD.

The distance UL is set shorter than the distance DL. The distance width RD is set wider than the distance width FD. When the vehicle is in an empty state, that is, there are no passengers in the driving section 5 and no cargo on the cargo platform 7, the lower connection axis P4 is lower than the lower pivot axis P3, as shown in FIGS. 2 and 3. The link mechanism 20 is configured to be located below.

When one of the left and right rear wheels 2 is lowered than its position in the empty vehicle state, and the other rear wheel 2 is raised above its position in the empty state, the upper link 21 and the link support portion 23 Even if the elastic member is twisted, the elastic member 29, and the left and right upper links 21 and lower links 22 move up and down smoothly. In this case, the lowered rear wheel 2 is displaced more forward than before the descent, the raised rear wheel 2 is displaced more rearward than before the ascent, and the wheel support member 11 is tilted left and right and back and forth, and after the descent. A positional shift occurs between the left and right rear wheels 2 in which the wheel 2 is located in front of the raised rear wheel 2 . However, the distance UL is shorter than the distance DL, the width of the gap RD is wider than the width of the gap FD, and the lower connection axis P4 is located below the lower pivot axis P3 in the empty state. Therefore, the positional deviation in the longitudinal direction between the lowered rear wheel 2 and the raised rear wheel 2 can be reduced.

As shown in FIGS. 3, 4, and 7, the upper link 21 and lower link 22 in the right link mechanism 20 are formed in a straight line. As shown in FIGS. 2, 4, and 6, the upper link 21 of the left link mechanism 20 has an intermediate portion that is connected to the front portion and It is formed into a curved shape located below the rear part. The lower link 22 in the left link mechanism 20 is formed in a curved shape with an intermediate portion protruding laterally outwardly so as to rise and fall while avoiding the intermediate portion of the upper link 21 laterally outwardly.

As shown in FIGS. 2, 3, and 5, the suspension mechanism 30 includes a pair of left and right suspension springs 31 and a pair of left and right dampers 32.

As shown in FIGS. 2 and 3, the left and right dampers 32 are connected to a suspension support portion 33 on the vehicle body side formed on the vehicle body frame 12 and a wheel provided on the wheel support member 11 by being formed on the case holder 16. It is connected to the side suspension support part 34 and expands and contracts as the wheel support member 11 moves up and down. The left and right suspension springs 31 are distributed to the left and right dampers 32 and fitted onto the outside of the dampers 32. The upper end portion of the suspension spring 31 is received and supported by a spring locking portion formed on the upper portion of the damper 32, and is supported by a suspension support portion 33 on the vehicle body side via the upper portion of the damper 32. The lower end portion of the suspension spring 31 is received and supported by a spring locking portion formed on the lower portion of the damper 32, and is supported by the wheel support member 11 via the lower portion of the damper 32. The left and right suspension springs 31 expand and contract as the damper 32 expands and contracts.

As shown in FIG. 5, the lateral link 40 includes a vehicle body side support portion 41 extending downward from the rear end of the vehicle body frame 12, and a wheel side support portion 41 extending upward from the lateral end of the wheel support member 11. The support portion 42 is connected to the support portion 42 .

As shown in FIGS. 10 and 11, the wheel side support portion 42 includes a pair of vertical plate portions 42a arranged front and rear with respect to the end portion 40a of the lateral link 40, and a pair of vertical plate portions 42a. It has a connecting plate part 42b that connects the horizontal ends, and an upper plate part 42c that is abutted from above on the upper ends of the pair of vertical plate parts 42a and receives the cushion material 51 of the stopper member 50.
The pair of vertical plate parts 42a are fixed to the wheel support member 11 by welding to the mounting table part 11b. The upper plate portion 42c extends from the upper end of the connecting plate portion 42b and is supported by the connecting plate portion 42b. Specifically, the upper plate part 42c is constituted by a bent end provided on the upper part of the connecting plate part 42b. The upper plate portion 42c and the pair of vertical plate portions 42a are not welded. The upper plate portion 42c is not attached to the pair of vertical plate portions 42a. The pair of vertical plate portions 42a and the connecting plate portion 42b are connected by integral molding. A screw shaft member 43 that pivotally supports the end portion 40a on the pair of vertical plate portions 42a is inserted through the end portion 40a and the pair of vertical plate portions 42a. The pair of vertical plate portions 42a are tightened by a screw shaft member 43 toward the end portion 40a so as to extend along the end portion 40a.

In the wheel side support part 42, the end part 40a is pivotally supported by the pair of vertical plate parts 42a by the screw shaft member 43, and the pair of vertical plate parts 42a are along the end part 40a, so that the lateral link 40 is attached to the wheel side support part 42. The lateral link 40 is supported so that it can swing up and down with respect to the side support portion 42 without wobbling.

An elastic member 44 is interposed between the lateral link 40 and the vehicle body side support portion 41. When twisting occurs between the lateral link 40 and the vehicle body support portion 41, the elastic member 44 is elastically deformed, and this elastic deformation eliminates the twisting. An elastic member is interposed between the lateral link 40 and the wheel-side support section 42, similarly to between the lateral link 40 and the vehicle-body support section 41.

As shown in FIG. 10, a stopper member 50 extends from the vehicle body frame 12 toward the wheel-side support portion 42. As shown in FIG. A cushion material 51 is provided at the lower end of the stopper member 50. When the wheel support member 11 rises, the cushion material 51 comes into contact with the upper end of the wheel side support part 42, and the cushion material 51 sets the upper limit of the rise of the wheel support member 11. The wheel side support portion 42 serves as a limit setting member that sets the limit of the rise of the rear wheel 2 relative to the vehicle body.

[Another embodiment]
(1) In the above-described embodiment, the suspension system 10 is shown as being used to support the rear wheels 2, but it may also be used to support the front wheels.

(2) In the embodiment described above, an example was shown in which the engine 8 and the transmission 13 were supported by the wheel support member 11, but the invention is not limited to this. For example, the transmission 13 may be supported but the engine 8 may not be supported, or neither the engine 8 nor the transmission 13 may be supported.

(3) In the embodiment described above, the left upper link 21 and the lower link 22 are formed in a curved shape, but if it is not necessary to avoid hitting the device part, they may be formed in a straight shape. good.

(4) In the embodiment described above, an example was shown in which the link mechanisms 20 were provided on the left and right sides, but the present invention is not limited to this. For example, the wheels may be supported by only one link mechanism having a pair of left and right lower links and one upper link provided above the lower links.

The present invention is applicable not only to multi-purpose work vehicles but also to various work vehicles such as rice transplanters and tractors.

1 Running wheels (rear wheels)
11 Wheel support member 20 Link mechanism 21 Upper link 22 Lower link 23 Link support portion 29 Elastic member 30 Suspension mechanism 33 Suspension support portion 40 Lateral link 40a End portion 41 Vehicle side support portion 42 Wheel side support B
42a Vertical plate portion 42b Connection plate portion 42c Upper plate portion 43 Screw shaft member P1 Upper pivot axis P2 Upper connection axis P3 Lower pivot axis P4 Lower connection axis DL Distance (lower pivot axis and lower connection axis between the core)
FD Width of interval (width of interval between upper pivot axis and lower pivot axis)
RD Width of spacing (width of spacing between upper connecting shaft and lower connecting shaft)
UL distance (between the upper pivot axis and the upper connection axis)

Claims (2)

a wheel support member that supports a pair of left and right running wheels;
a link mechanism that is provided across the vehicle body and the wheel support member and supports the wheel support member so as to be movable up and down;
a suspension mechanism that is provided across a suspension support portion formed on the vehicle body and the wheel support member, and elastically supports the wheel support member;
a lateral link that is connected to a vehicle body side support portion formed on the vehicle body and a wheel side support portion formed on the wheel support member, and that restricts left and right movement of the wheel support member;
The link mechanism has a front end portion supported by a link support portion formed on the vehicle body so as to be vertically swingable around the upper pivot axis, and a rear end portion supported by the wheel support member so as to be able to swing relative to the upper link axis around the upper connection axis. The upper link is movably connected, the front end is supported by the link support part so as to be swingable up and down about the lower pivot axis, and the rear end part is supported by the wheel support member for relative rocking about the lower link axis. a lower link movably connected;
The upper link is formed in a curved shape in which the middle part is located lower than the front part and the rear part,
The lower link is formed in a curved shape with the middle part of the lower link protruding laterally outwardly so as to avoid the middle part of the upper link laterally outwardly,
The upper link passes along the side of the engine in the longitudinal direction of the vehicle body,
In the work vehicle , the intermediate portion of the upper link downwardly avoids an engine accessory device provided on a side portion of the engine . The work vehicle according to claim 1 , wherein the engine accessory device is an alternator cover.

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