Patent Description:
[<NUM>] A problem corresponding to Background Art [<NUM>] is as follows.

In the case of the conventional work vehicle, in order to prevent a front lower portion of the hood when this hood is pivotally opened/closed from interfering with the front portion of the engine, the front portion of the hood may sometimes be forwardly largely spaced from the front portion of the engine. In such case, enlargement of the hood may be invited disadvantageously.

In view of the above, there is a need for a work vehicle that can prevent the hood during its pivotal opening/closing from interfering with the engine, without enlarging the hood.

[<NUM>] A solution addressing to the problem [<NUM>] is as follows.

According to a characterizing feature of the present invention, a work vehicle is defined in claim <NUM>, and comprises:.

With the above-described characterizing feature, when the hood is pivotally opened/closed, the cover member will not be pivoted together with the hood, but will remain on the side of the machine body frame. And, even when the front lower portion of the hood is located adjacent the front portion of the engine, this front lower portion of the hood does not interfere with the front portion of the engine since this front portion of the engine enters the opening. Namely, there can be realized a work vehicle that can prevent the hood during its pivotal opening/closing from interfering with the engine, without enlarging the hood.

Further, in the present invention, preferably:.

Here, in case a clutch device is provided forwardly adjacent the engine, there is a possibility of occurrence of interference between the front lower portion of the hood and the clutch device in the course of a pivotal opening/closing of the hood. With the above-described characterizing arrangement, as the clutch device enters the opening when the hood is pivotally opened/closed, such interference between the front lower portion of the hood and the clutch device can be avoided.

Further, in the present invention, preferably, the opening has a shape having a wider lateral width than the clutch device and extending to an upper side height position higher than the upper end of the clutch device.

With this characterizing feature, the shape of the opening has larger dimensions than the clutch device in the left/right direction and the upper direction. With this, it becomes possible to allow the clutch device to enter the opening in a reliable manner in the course of pivotal opening/closing of the hood.

Further, in the present invention, preferably, at a portion of the hood along the opening, a frame member is attached.

With this characterizing feature, a gap between the portion of the hood along the opening and the cover member can be closed by the frame member.

With this characterizing feature, the cover member can be supported firmly and reliably with utilizing the stay having high rigidity.

Here, in case such front grill is provided at a front portion of the hood, there is a possibility of occurrence of interference between the front lower portion of the hood and the front portion of the engine in the course of pivotal opening/closing of the hood. With the above-described characterizing arrangement, the front portion of the engine enters opening in the course of pivotal opening/closing of the hood, so that such interference between the front lower portion of the front grill and the front portion of the engine can be avoided.

Next, a first embodiment will be explained.

Embodiments for embodying the present invention will be explained with reference to the accompanying drawings. In the following explanation, the direction of arrow F will be defined as "machine body front side", the direction of arrow B will be defined as "machine body rear side", the direction of arrow L will be defined as "machine body left side" and the direction of arrow R will be defined as "machine body right side", respectively.

<FIG> and <FIG> show a riding grass cutting machine (corresponding to a "work vehicle" relating to the present invention). This riding grass cutting machine includes a traveling machine body <NUM>. The traveling machine body <NUM> includes a machine body frame <NUM>, a pair of left and right steerable front wheels 3F and a pair of left and right drivable rear wheels 3B. The machine body frame <NUM> includes a pair of left and right main frames 2A extending along the machine body front/rear direction. At a front portion of the traveling machine body <NUM>, an engine section <NUM> is provided. Rearwardly of this engine section <NUM>, a driving section <NUM> is provided. Under the traveling machine body <NUM> and between the front wheels 3F and the rear wheels 3B, a mower <NUM> (corresponding to an "implement" relating to the present invention) is provided. To a rear portion of the traveling machine body <NUM>, there is supported a grass collecting container <NUM> for collecting cut grass pieces from the mower <NUM>.

The engine section <NUM> includes an engine E, a muffler <NUM> for exhausting exhaust gas of the engine E, a radiator <NUM> for discharging heat of engine cooling water, and a hood <NUM> housing the engine E, etc. The engine E is mounted to a front portion of the machine body frame <NUM>. At the outer circumferential portion of the radiator <NUM>, there is provided a plate-like frame <NUM> for closing a gap formed around the radiator <NUM>. The hood <NUM> is configured to be pivotally opened/closed about a front pivot S1. A damper <NUM> is provided for urgingly pivoting the hood <NUM> toward its opening side.

The driving section <NUM> includes a driver's seat <NUM> and a maneuvering tower <NUM>. The maneuvering tower <NUM> includes a steering wheel <NUM>, a meter panel <NUM>, a key switch <NUM> (corresponding to a "start commanding section") for commanding starting of the engine E, and a panel <NUM> for covering a column (not shown), etc. which supports the steering wheel <NUM>.

As shown in <FIG>, there is provided a lock mechanism <NUM> for position-maintaining the hood <NUM> under its closed state. This lock mechanism <NUM> is provided at a portion corresponding to a rear portion of the hood <NUM>. The lock mechanism <NUM> includes a shaft <NUM> (corresponding to an "engaged portion"), a hook <NUM>, and a spring <NUM>.

The shaft <NUM> is provided at a rear portion of the hood <NUM>. The shaft <NUM>, inside the hood <NUM>, is supported to a ceiling plate of the hood <NUM> via a stay <NUM>. The shaft <NUM> includes an action portion 20a extending toward the rear side when the hood <NUM> is closed. At an upper portion of the frame <NUM>, there is formed an opening 11a which is opened toward the upper side so as to allow entrance of the action portion 20a therein in association with a pivotal movement of the hood <NUM> to the closing side.

The hook <NUM> is arranged to be pivotable about a pivot axis Y1 (a pivot axis parallel with a pivot axis Y2 which will be described later) between a locked position (see <FIG>) in which the hook <NUM> is engaged with the action portion 20a and a released position (see <FIG>) in which the hook <NUM> is not engaged with the action portion 20a. The pivot axis Y1 is a pivot axis that extending along the horizontal direction in the machine body front/rear direction. The hook <NUM> is disposed rearwardly of the frame <NUM>. The hook <NUM> is provided with an acted portion 21a which is subjected to a pressing action by the action portion 20a from the upper side in association with a pivotal movement of the hood <NUM> toward the closing side. In the hook <NUM>, there is formed an engagement groove 21b engageable with the action portion 20a.

A support plate <NUM> is provided for supporting the hook <NUM>, etc. This support plate <NUM> is disposed rearwardly of the hook <NUM>. The hook <NUM> is supported to a support shaft <NUM> to be pivotable about the pivot axis Y1 and also is supported to the support plate <NUM> via the support shaft <NUM>. The support plate <NUM> is supported to the frame <NUM> via left and right stays <NUM>.

The spring <NUM> urges the hook <NUM> for its pivotal movement about the pivot axis Y1 toward the locked position side. This spring <NUM> is provided between the hook <NUM> and the support plate <NUM>. The support plate <NUM> has a hook portion 24a to which the spring <NUM> is hooked.

At a front face portion of the support plate <NUM>, there is provided a positioning portion 24b for fixing the hook <NUM> in position at the locked position. The left stay <NUM> functions also as a positioning member for positioning the hook <NUM> at the released position (see <FIG>). To the hook <NUM>, there is connected a release lever <NUM> for pivotally operating the hook <NUM> about the pivot axis Y1 toward the released position in order to release the engagement of the hook <NUM> with the action portion 20a. An end portion of the release lever <NUM> opposite to the hook <NUM>, a handgrip 27a is provided. This handgrip 27a protrudes upwards from the upper portion of the panel <NUM>.

As shown in <FIG>, a detection mechanism <NUM> is provided for detecting an opened or closed state of the hood <NUM>. This detection mechanism <NUM> is provided at a portion corresponding to the rear portion of the hood <NUM>. The detection mechanism <NUM> includes a shaft <NUM> (corresponding to a "detected portion"), a pivot arm <NUM> (corresponding to a "pivotal member"), a spring <NUM> (corresponding to an "urging member"), and a detection switch <NUM>. Namely, the "detected portion" relating to the present invention and the "engaged portion" relating to the present invention are same (same shaft <NUM>).

The pivot arm <NUM> is configured to be pivotable about the pivot axis Y2. This pivot axis Y2 is a pivot axis that extends along the horizontal direction in the machine body front/rear direction. The pivot arm <NUM> is disposed between the hook <NUM> and the support plate <NUM>. Namely, the detection mechanism <NUM> is disposed at a portion adjacent the lock mechanism <NUM>. The pivot arm <NUM> is supported to a support shaft <NUM> to be pivotable about the pivot axis Y2 and also supported to the support plate <NUM> via the support shaft <NUM>. The pivot arm <NUM> includes an acted portion 29a subjected to a pressing action of the action portion 20a from the above, in association with a pivotal movement of the hood <NUM> toward the closing side.

At a portion of the pivot arm <NUM> opposite to the acted portion 29a relative to the pivot axis Y2, there is provided a pin <NUM> extending along the front/rear direction. The support plate <NUM> defines a slot 24c through which the pin <NUM> is inserted. The slot 24c has an arcuate portion centering about the pivot axis Y2.

Namely, the pivot arm <NUM> is arranged to be pivotable about the pivot axis Y2 within an angular range in which the pin <NUM> is movable within the slot 24c. Here, regarding pivotal positions of the pivot arm <NUM>, a position thereof when the pin <NUM> has reached the lower end of the slot 24c (the state of the pin <NUM> coming into contact with a portion along the lower end portion of the slot 24c of the support plate <NUM>) will be referred to as a position corresponding to the state of the action portion 20a not acting on the pivot arm <NUM> (the acted portion 29a) (this position will be referred to as "initial positon" hereinafter, see <FIG>), whereas a position thereof when the pin <NUM> has reached the upper end portion of the slot 24c (the state of the pin <NUM> coming into contact with a portion along the upper end portion of the slot 24c of the support plate <NUM>) will be referred to as a position corresponding to the closed state of the hood <NUM> (this position will be referred to as a "closing position" hereinafter, see <FIG>).

The spring <NUM> urges the pivot arm <NUM> for its pivoting about the pivot axis Y2, opposite to the closed position (namely, toward the initial position). This spring <NUM> is disposed rearwardly of the support plate <NUM>. The spring <NUM> is provided between the pin <NUM> and the support plate <NUM>. The support plate <NUM> is provided with a hook portion 24d to which the spring <NUM> is to be hooked.

The detection switch <NUM> detects the pivot arm <NUM> being located at the closing position. The detection switch <NUM> is disposed between the frame <NUM> and the support plate <NUM>. The detection switch <NUM> is supported to the support plate <NUM> as the detection switch <NUM> is located adjacent the end portion (right end portion) opposite the acted portion 29a of the pivot arm <NUM>. The detection switch <NUM> includes a lever 31a.

<FIG> shows a control arrangement. This control arrangement includes a control section <NUM>, the engine E, the key switch <NUM> and the detection switch <NUM>. The control section <NUM> is configured to be capable of receiving a signal from the key switch <NUM>, a signal from the detection switch <NUM>, and other signals. The control section <NUM> starts the engine E in response to a command from the key switch <NUM>, if the detection mechanism <NUM> detects the hood <NUM> being under the closed state. On the other hand, in case the detection mechanism <NUM> does not detect the hood <NUM> being under the closed state, the control section <NUM> does not start the engine E against the command from the key switch <NUM>.

As shown in <FIG>, when the hood <NUM> is pivoted to the closing side, the action portion 20a enters the opening 11a to apply a pressing action from above to the acted portion 21a of the hook <NUM>. With this, the hook <NUM> is pivoted about the pivot axis Y1 toward the releasing position side against the urging force of the spring <NUM>.

Subsequently, the action portion 20a applies a pressing action from above onto the acted portion 29a of the pivot arm <NUM>. With this, the pivot arm <NUM> is pivoted about the pivot axis Y2 to the closing position against the urging force of the spring <NUM>.

And, when the action portion 20a is lowered to the height position corresponding to the engagement groove 21b of the hook <NUM>, under the urging force of the spring <NUM>, the hook <NUM> is pivoted toward the locked position side about the pivot axis Y1.

Finally, as shown in <FIG>, the hook <NUM> will come into engagement with the action portion 20a via the engagement groove 21b and will be fixed position at the locked position by the positioning portion 24b. Namely, the hood <NUM> will be maintained under the closed state by the lock mechanism <NUM>.

And, under the above-descried state in which the hood <NUM> is position-maintained under the closed state by the lock mechanism <NUM>, the detection switch <NUM> is to detect that the pivot arm <NUM> is located at the closing position as this pivot arm <NUM> applies a pressing action onto the lever 31a of the detection switch <NUM>. Namely, the closed state of the hood <NUM> is detected by the detection mechanism <NUM>.

Here, as described above, the control section <NUM> starts the engine E in response to a command from the key switch <NUM>, if the detection mechanism <NUM> detects the hood <NUM> being under the closed state.

Thereafter, as shown in <FIG>, when the hook <NUM> is pivotally operated by the release lever <NUM> about the pivot axis Y1 to the releasing position against the urging force of the spring <NUM>, the engagement of the hook <NUM> with the action portion 20a will be released. Namely, the position maintenance of the hood <NUM> under the closed state by the lock mechanism <NUM> will be released.

And, under the state of release of the position maintenance of the hood <NUM> under the closed state by the lock mechanism <NUM>, if the hood <NUM> is pivoted toward the opening side, the action portion 20a will be moved upward away from the acted portion 29a of the pivot arm <NUM>. With this, the pivot arm <NUM> will be pivoted about the pivot axis Y2 to the initial position under the urging force of the spring <NUM>, and the pivot arm <NUM> will be moved away from the lever 31a of the detection switch <NUM>. Namely, the detection mechanism <NUM> will no longer detect the pivot arm <NUM> being located at the closing position.

Here, as described above, the control section <NUM> does not start the engine E against the command from the key switch <NUM>, if the detection mechanism <NUM> does not detect the hood <NUM> being under the closed state.

As shown in <FIG>, between the power steering device <NUM> for the steering wheel <NUM> and a hydraulic device (not shown), there are provided a plurality of pipe-like members. The plurality of pipe-like members include a first pipe-like member <NUM>, a second pipe-like member <NUM>, and a third pipe-like member <NUM>. The first pipe-like member <NUM> includes a first hydraulic hose 36a made of soft material (e.g. made of rubber), and a first hydraulic pipe 36b made of hard material (e.g. made of metal). The first hydraulic hose 36a and the first hydraulic pipe 36b are connected to each other via a first joint 36c. The second pipe-like member <NUM> includes a second hydraulic hose 37a made of soft material (e.g. made of rubber), and a second hydraulic pipe 37b made of hard material (e.g. made of metal). The second hydraulic hose 37a and the second hydraulic pipe 37b are connected to each other via a second joint 37c. The third pipe-like member <NUM> includes a third hydraulic hose 38a made of soft material (e.g. made of rubber), and a third hydraulic pipe 38b made of hard material (e.g. made of metal). The third hydraulic hose 38a and the third hydraulic pipe 38b are connected to each other via a third joint 38c.

The first joint 36c, the second joint 37c and the third joint 38c are disposed inside the panel <NUM>. The first joint 36c, the second joint 37c and the third joint 38c are disposed with respective vertical positions thereof relative to each other being offset from each other. With this arrangement, when the first joint 36c, the second joint 37c and the third joint 38c are to be fastened or loosened in the limited space available inside the panel <NUM> for instance, the adjacent ones of the first joint 36c, the second joint 37c and the third joint 38c will not interfere with each other, and a space for inserting a tool can be secured.

Next, a second embodiment , corresponding to the present invention, will be explained.

As shown in <FIG> and <FIG>, at a front end portion of a traveling machine body <NUM>, a weight unit <NUM> is provided. This weight unit <NUM> includes a bracket <NUM> provided at a front end portion of a machine body frame <NUM> and left and right front weights <NUM> detachably attached to the bracket <NUM>.

A PTO (power take-off) shaft <NUM> is provided for taking off power of an engine E for driving a mower <NUM>. Between an output shaft (not shown) of the engine E and the PTO shaft <NUM>, there is provided a belt transmission mechanism <NUM> for transmitting power of the output shaft to the PTO shaft <NUM>. As the power of the output shaft is transmitted by the belt transmission mechanism <NUM> to the PTO shaft <NUM>, the mower <NUM> is driven.

At the forward vicinity of the engine E, there is provided a clutch device <NUM> for engaging/disengaging power transmission to the mower <NUM>. The clutch device <NUM>, as being positioned forwardly of the belt transmission mechanism <NUM>, is connected to a font end portion of the output shaft. The clutch device <NUM> is constituted of an electromagnetic clutch. The clutch device <NUM> is configured to be switchable between a state (engaged state) for transmitting the power of the output shaft to the belt transmission mechanism <NUM> and a state (disengaged state) for not transmitting the power of the output shaft to the belt transmission mechanism <NUM>.

As shown in <FIG>, the hood <NUM> includes a hood body portion <NUM> and a front grill <NUM>. The front grill <NUM> is attached to a front portion of the hood body portion <NUM>. In the front grill <NUM>, there are formed many ventilation holes (not shown). At a left lower portion of the front grill <NUM>, there is formed a hole 126a for exposing an exhaust pipe 8a for the muffler <NUM> to the outside.

Between an upper portion and a lower portion of the front portion of the hood body portion <NUM>, a support member <NUM> is provided. To this support member <NUM>, the front grill <NUM>, etc. are supported. At the front end portions of the left and right main frames 2A, there are provided left and right stays <NUM> respectively. The hood <NUM> is supported via the support member <NUM> to the left and right stays <NUM> to be pivotable about a pivot axis X1. This pivot axis X1 is a pivot axis extending along the machine body left/right direction.

The support member <NUM> includes upper and lower horizontal stays <NUM> extending along the machine body left/right direction, an upper vertical stay <NUM> connected to the upper horizontal stay <NUM> and extending upwards and left and right lower vertical stays <NUM> connected to the left and right end portions of the upper and lower horizontal stays <NUM> and extending downwards. The left and right lower vertical stays <NUM> are supported to the left and right stays <NUM> via left and right bolts <NUM> to be pivotable about the pivot axis X1. At the lower end portions of the lower vertical stays <NUM>, support portions 131a are formed. The support portions 131a are placed in abutment against the stays <NUM> from the lateral outer side and fixed under this state with the bolts <NUM>. The bolts <NUM> are inserted into the support portions 131a from the lateral outer side.

At a front lower portion of the hood <NUM>, there is formed an opening 10a which is opened to the lower side. The opening 10a is formed between the hood body portion <NUM> and the front grill <NUM>. The opening 10a is overlapped with the clutch device <NUM> as seen in a front view. The opening 10a is formed to extend with a width greater than the lateral width of the clutch device <NUM> and to extend to a position higher than the upper end of the clutch device <NUM>. The support portions 131a extend through the opening 10a to the outside of the hood <NUM>.

A cover member <NUM> is provided to cover the opening 10a as being disengaged from the hood <NUM>. The cover member <NUM> is supported to the left and right stays <NUM>. The left end portion of the cover member <NUM> is placed in abutment against the left stay <NUM> from the front side and fixed under this state with a screw <NUM>. The right end portion of the cover member <NUM> is placed in abutment against the right stay <NUM> from the front side and fixed under this state with a screw <NUM>. The screws <NUM> are inserted to the cover member <NUM> from the front side thereof.

At a portion of the hood <NUM> along the opening 10a, a frame member <NUM> is attached. The frame member <NUM> has an approximately portal shape as seen in a front view. A gap formed between the portion of the hood <NUM> along the opening 10a and the cover member <NUM> is closed by the frame member <NUM>. The frame member <NUM> is fixed to the lower horizontal stays <NUM> with bolts <NUM>.

As shown in <FIG>, when the hood <NUM> is pivotally opened/closed, the cover member <NUM> is not pivoted together with the hood <NUM>, but will remain on the side of the machine body frame <NUM>. And, when the hood <NUM> is pivotally opened/closed, the clutch device <NUM> enters the opening 10a, so that the front lower portion of the hood <NUM> does not interfere with the clutch device <NUM>.

As shown in <FIG>, the exhaust pipe 8a extends obliquely from the left side portion of the muffler <NUM> toward the front lower side. The exhaust pipe 8a is caused to extend as long as possible so as to prevent exhaust gas from reaching the front grill <NUM>. With this arrangement, it is possible to prevent the exhaust gas from falling on the front grill <NUM>, thus soiling or damaging this front grill <NUM>.

Claim 1:
A work vehicle comprising:
an engine (E) mounted at a front portion of a machine body frame (<NUM>); and
a hood (<NUM>) pivotally openable/closable about a front pivot (S1) and housing the engine (E);
wherein at a front lower portion of the hood (<NUM>), there is formed an opening (10a) opened toward the lower side; and
there is provided a cover member (<NUM>) supported to the machine body frame (<NUM>), the cover member (<NUM>) being configured to cover the opening (10a) when disengaged from the hood (<NUM>), wherein:
the machine body frame (<NUM>) includes left and right stays (<NUM>) that pivotally support the hood (<NUM>);
the cover member (<NUM>) is supported to the left and right stays (<NUM>);
the cover member (<NUM>) includes left and right end portions;
the left end portion of the cover member (<NUM>) is placed in abutment against the left stay (<NUM>) from the front side and fixed under this state with a screw (<NUM>); and
the right end portion of the cover member (<NUM>) is placed in abutment against the right stay (<NUM>) from the front side and fixed under this state with a screw (<NUM>).