Patent Description:
As shown in patent literature <NUM> and <NUM>, for example, the tractor is equipped with an engine bonnet (bonnet) that forms an engine compartment, and in the engine compartment, an exhaust-gas cleaning apparatus (exhaust-gas cleaning process apparatus) is installed above the engine.

Patent literature <NUM> describes a working vehicle which is configured so that rigidity for supporting an aqueous urea solution tank can be easily improved and so that the aqueous urea solution tank can be easily heated or protected. The working vehicle is provided with: an operation section where the operator is positioned; a first case for removing particulate matter in the exhaust gas of an engine; a second case for removing nitrogen oxide in the exhaust gas of the engine; a urea mixing pipe for connecting the second case to the first case; and the aqueous urea solution tank for supplying an aqueous urea solution to the urea mixing pipe. The aqueous urea solution tank is mounted through a tank support body to a traveling machine body below the operation section, and the aqueous urea solution tank is mounted downstream in the direction of flow of engine cooling air discharged from the engine side.

Patent literature <NUM> describes a diesel engine in which a DPF case and an SCR catalyst case can be placed compactly. The diesel engine includes an engine body, the DPF case and the SCR catalyst case, a DPF is accommodated in the DPF case, an SCR catalyst is accommodated in the SCR catalyst case, and the DPF case and the SCR catalyst case are mounted on the engine body. The SCR catalyst case is placed in a direction which extends along the DPF case. The DPF case is placed directly above a flywheel housing and right behind a cylinder head cover, and the SCR catalyst case is placed directly above the cylinder head cover.

Patent literature <NUM> describes an exhaust system that may have an emissions control system including a mount and at least one exhaust treatment device secured to the mount. The exhaust system may also have a mounting assembly including a platform and a base frame. The emissions control system may be secured to the platform. The mounting assembly may be configured to position the emissions control system substantially adjacent to a power source. The platform may be movable relative to the base frame between a first position and a second position.

Patent literature <NUM> describes an engine device for a work vehicle, in which an engine, a first case, and a second case can be constituted in the same vibration structure, and exhaust gas path structure between the engine and the second case can be constituted in such a manner as to reduce costs. The engine device for a work vehicle includes the first case for removing particulate matter in exhaust gas of the engine and the second case for removing nitrogen oxides in the exhaust gas of the engine, and configured to connect the first case to the second case via a urea mixing pipe. The engine, the first case, and the second case are integrally adhered, and the engine, the first case, and the second case are configured to be integrally vibrated in a swingable manner.

Patent Literature <NUM> describes an engine device that includes an exhaust gas purification device, which can be efficiently arranged in an engine installation space. The engine is arranged on the lower side of a maneuvering seat, and a flywheel housing is arranged in such a manner as to be positioned on the front portion side of a traveling machine body, and the exhaust gas purification device is arranged on the upper side of the rear of the engine. Also, the engine is coupled with an air cleaner that draws in fresh air on the left side thereof. Furthermore, a hood includes a hood cover configured to be openable/closable in the rear thereof and covers the upper portion of the exhaust gas purification device.

There is a demand for a tractor to be provided with a plurality of exhaust-gas cleaning apparatuses for cleaning exhaust gas discharged from an engine. Examples of the plurality of exhaust-gas cleaning apparatuses include an exhaust-gas cleaning apparatus that cleans exhaust gas using a cleaning filter and an exhaust-gas cleaning apparatus that cleans exhaust gas using a reducing agent.

When the conventional art is adopted and the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus are installed in the engine compartment, the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus are located above the engine, and thus, even when the size of one of the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus is smaller than the size of the other exhaust-gas cleaning apparatus, the mounting height of the engine bonnet must be set to correspond to the larger exhaust-gas cleaning apparatus. Therefore, the mounting height of the engine bonnet is increased.

The present invention provides a tractor for which it is possible to provide a first exhaust-gas cleaning apparatus and a second exhaust-gas cleaning apparatus in an engine compartment while keeping the mounting height of the engine bonnet low, keeping the front-back length of the engine compartment short, and supporting the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus onto the vehicle body frame while in an appropriate connection state.

The tractor of the present invention comprises: a vehicle body; an engine bonnet forming an engine compartment; an engine disposed in the engine compartment; a first exhaust-gas cleaning apparatus and a second exhaust-gas cleaning apparatus. The first exhaust-gas cleaning apparatus is configured to clean exhaust gas discharged from the engine and is disposed in the engine compartment such that a longitudinal direction of the first exhaust-gas cleaning apparatus is substantially parallel to a vehicle-body lateral width direction. The second exhaust-gas cleaning apparatus is configured to clean exhaust gas discharged from the engine and is disposed in the engine compartment behind the engine such that a longitudinal direction of the second exhaust-gas cleaning apparatus is substantially parallel to the vehicle-body lateral width direction. The tractor further comprises a vehicle body frame and a support member supported by the vehicle body frame and supporting the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus. The support member comprises a support part extending upward from the vehicle body frame along a front portion of the second exhaust-gas cleaning apparatus while supporting the front portion and a support arm extending forward from an upper portion of the support part along a lower portion of the first exhaust-gas cleaning apparatus while supporting the lower portion.

According to this configuration, the first exhaust-gas cleaning apparatus, which may be the smaller of the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus, is installed above the engine, and the second exhaust-gas cleaning apparatus, which may be larger, is installed behind the engine, and the mounting height of the engine bonnet can be set based on the size of the small first exhaust-gas cleaning apparatus. Furthermore, since the longitudinal direction of both the first and second exhaust-gas cleaning apparatuses is substantially parallel to the vehicle-body lateral width direction, the first and second exhaust-gas cleaning apparatuses can be accommodated compared to the case where the longitudinal direction is substantially parallel to the vehicle-body longitudinal direction, and it is possible to shorten the length of the space in a vehicle-body longitudinal direction (or a vehicle-body front-back direction) necessary for the installation of the first exhaust-gas cleaning apparatus, while keeping the mounting height of the engine bonnet low and the longitudinal length of the engine compartment shorter, and a second exhaust-gas cleaning apparatus can be provided in the engine compartment.

Because the positional relationship between the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus is supported by the vehicle body frame in a state where the positional relationship is set by the support member, the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus can be easily connected; for example, even in a connection structure that does not have a function enabling adjustment of the positional relationship between the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus, the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus can be connected in a positional relationship advantageous for connection.

Preferably, the vehicle body frame comprises a flywheel housing extending backward from the back portion of the engine and positioned below the second exhaust-gas cleaning apparatus, and the support part extends upward from the flywheel housing toward the vehicle body.

According to this configuration, since the support part extends upward from the flywheel housing located below the second exhaust-gas cleaning apparatus, the length of the support part can be shortened, and it is possible to firmly support the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus onto the vehicle body frame such that the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus do not readily swing.

Preferably, the tractor further comprises a first position adjustment portion configured to adjust a support position of the second exhaust-gas cleaning apparatus on the support part in a vehicle-body vertical direction (or a vehicle-body up-down direction), a vehicle-body longitudinal direction, and a vehicle-body lateral width direction.

According to the present configuration, even when there is a positional shift between the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus in the vehicle-body vertical direction, the vehicle-body longitudinal direction, and the vehicle-body lateral width direction due to manufacturing errors in the support member, by for example, adjusting the positional shift via the first position adjustment portion, for example, the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus can be connected even in a connection structure not provided with a function for correcting the positional shift, and thus the connection structure can be simplified in that a special positional shift adjustment portion is not required in a connection structure that connects the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus.

Preferably, the tractor further comprises a lower support portion that is supported below the support part and supports a lower portion of the second exhaust-gas cleaning apparatus.

According to this configuration, the front portion of the second exhaust-gas cleaning apparatus is supported by the support part, and the lower portion of the second exhaust-gas cleaning apparatus is supported by the support part, and thus the second exhaust-gas cleaning apparatus can be firmly supported by the support member.

Preferably, the tractor further comprises a second position adjustment portion configured to adjust a support position of the second exhaust-gas cleaning apparatus on the lower support portion in a vehicle-body vertical direction, a vehicle-body longitudinal direction, and a vehicle-body lateral width direction.

According to the present configuration, even when there is a positional shift between the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus in the vehicle-body vertical direction, the vehicle-body longitudinal direction, and the vehicle-body lateral width direction due to manufacturing errors in the support member, for example, by adjusting the positional shift via a second position adjustment portion, for example, the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus can be connected even in a connection structure not provided with a function for correcting the positional shift, and thus the connection structure can be simplified in that a special positional shift adjustment portion is not required in a connection structure that connects the first exhaust-gas cleaning apparatus and the second exhaust-gas cleaning apparatus.

Preferably, the support part comprises a seat portion disposed at a lower portion of the support part and connected to the vehicle body frame to make the support part supported by the vehicle body frame, and the lower support portion constitutes a part of the seat portion.

According to this configuration, the seat portion serves as a connection member for supporting the lower support portion on the support part, and thus the structure of providing the lower support portion on the support post portion can be simplified without requiring a special connection member.

An embodiment that is one example of the present invention is described below based on the drawings.

Note that in the following description, in regards to a traveling vehicle body of a tractor, the direction of arrow F illustrated in <FIG> is defined as "vehicle-body front", the direction of arrow B is defined as "vehicle-body back", the direction of arrow U is defined as "vehicle-body up", the direction of arrow D is defined as "vehicle-body down", the direction heading toward the surface of the page is defined as "vehicle-body left", and the direction heading toward the reverse face of the page is defined as "vehicle-body right".

As illustrated in <FIG>, the tractor is provided with a traveling vehicle body <NUM> supported by a pair of left and right front wheels <NUM>, which can be steered and driven, and a pair of left and right back wheels <NUM>, which can be driven. A vehicle body frame <NUM> of the traveling vehicle body <NUM> is constituted by an engine <NUM>, a flywheel housing <NUM> connected to a back portion of the engine <NUM>, a clutch housing <NUM> connected to a back portion of the flywheel housing <NUM>, a transmission case 7a connected to a back portion of the clutch housing <NUM>, and a front frame <NUM> connected to a lower portion of the engine <NUM>. A motor unit <NUM> provided with the engine <NUM> is formed in a front portion of the traveling vehicle body <NUM>. A driver's seat <NUM> and a driving unit <NUM>, which is provided with a steering wheel <NUM> whereby a steering operation of the front wheels <NUM> is performed, are formed in a back portion of the traveling vehicle body <NUM>. A linking mechanism <NUM>, which connects a work apparatus such as a rotary tilling apparatus (not illustrated) in a manner enabling a raising and lowering operation of the work apparatus, and a power takeoff shaft <NUM>, which takes power from the engine <NUM> and outputs this to the connected work apparatus, are provided in a back portion of the transmission case 7a. Reference numeral <NUM> illustrated in <FIG> is a ROPS frame.

As illustrated in <FIG> and <FIG>, the motor unit <NUM> is provided with an engine compartment <NUM>. The engine compartment <NUM> is formed by an engine bonnet <NUM>, which covers the engine compartment <NUM> from above and the front; a partition member <NUM> that forms a partition between the engine compartment <NUM> and the driving unit <NUM>; and the like.

As illustrated in <FIG> and <FIG>, the engine <NUM>, a radiator <NUM> that cools the engine <NUM>, and a first exhaust-gas cleaning apparatus (DPF) <NUM> and second exhaust-gas cleaning apparatus (SCR) <NUM> that perform cleaning processes of exhaust gas exhausted by the engine <NUM> are provided in the engine compartment <NUM>.

As illustrated in <FIG>, the radiator <NUM> is provided in front of the engine <NUM>. A blowing action of a rotary fan <NUM> positioned between the radiator <NUM> and the engine <NUM> introduces cooling air from outside the engine compartment <NUM> to inside the engine compartment and supplies the cooling air to the radiator <NUM>. The cooling air is supplied to the radiator <NUM> in a state of the cooling air passing through the radiator <NUM> from front to back. In the radiator <NUM>, engine cooling water is cooled by heat exchange between the supplied cooling air and the engine cooling water. The engine <NUM> is cooled by the cooled engine cooling water being supplied to the engine <NUM>.

The engine <NUM> is a diesel engine. As illustrated in <FIG> and <FIG>, the first exhaust-gas cleaning apparatus <NUM> is provided above the engine <NUM> in a state wherein a longitudinal direction of the first exhaust-gas cleaning apparatus is substantially parallel to a vehicle-body lateral width direction. A maximum length H in a vehicle-body vertical direction of the first exhaust-gas cleaning apparatus <NUM> is set to be shorter than a maximum length W in a vehicle-body longitudinal direction of the first exhaust-gas cleaning apparatus <NUM>. As illustrated in <FIG> and <FIG>, an exhaust-gas suctioning portion 21a, which is provided to a part on one end side, in a vehicle-body lateral width direction, of the first exhaust-gas cleaning apparatus <NUM>, and an exhaust-gas exhausting portion 5a, which is provided to the engine <NUM>, are connected. An exhaust-gas discharging portion 21b is provided to a part on another end side, in the vehicle-body lateral width direction, of the first exhaust-gas cleaning apparatus <NUM>. In the present embodiment, the exhaust-gas suctioning portion 21a protrudes downward from a lower portion of the first exhaust-gas cleaning apparatus <NUM> at an end portion on a vehicle-body left horizontal side of the first exhaust-gas cleaning apparatus <NUM>, and the exhaust-gas discharging portion 21b protrudes backward from an end portion on a vehicle-body right horizontal side of the first exhaust-gas cleaning apparatus <NUM>.

In the first exhaust-gas cleaning apparatus <NUM>, the exhaust gas exhausted by the engine <NUM> from the exhaust-gas exhausting portion 5a is suctioned by the exhaust-gas suctioning portion 21a into the apparatus, and diesel microparticles included in the suctioned exhaust gas are collected by a collection filter (not illustrated). This performs an exhaust-gas cleaning process of decreasing the diesel microparticles. The exhaust gas subjected to the cleaning process is discharged from the exhaust-gas discharging portion 21b.

As illustrated in <FIG> and <FIG>, the second exhaust-gas cleaning apparatus <NUM> is provided behind the engine <NUM> in a state wherein a longitudinal direction of the second exhaust-gas cleaning apparatus is substantially parallel to the vehicle-body lateral width direction. An exhaust-gas introduction portion 22a, which is provided to a part on one end side, in the vehicle-body lateral width direction, of the second exhaust-gas cleaning apparatus <NUM>, and the exhaust-gas discharging portion 21b of the first exhaust-gas cleaning apparatus <NUM> are connected by a connecting pipe <NUM>. An exhaust-gas discharging portion 22b is provided to a part on another end side, in the vehicle-body lateral width direction, of the second exhaust-gas cleaning apparatus <NUM>. In the present embodiment, the exhaust-gas introduction portion 22a is provided to an end portion on a vehicle-body left horizontal side of the second exhaust-gas cleaning apparatus <NUM>, and the exhaust-gas discharging portion 22b is provided to an end portion on a vehicle-body right horizontal side of the second exhaust-gas cleaning apparatus <NUM>.

In the second exhaust-gas cleaning apparatus <NUM>, the exhaust gas discharged by the first exhaust-gas cleaning apparatus <NUM> from the exhaust-gas discharging portion 21b is supplied by the connecting pipe <NUM> to the exhaust-gas introduction portion 22a and introduced by the exhaust-gas introduction portion 22a into the apparatus, and the introduced exhaust gas is subjected to the cleaning process by a reducing agent. Specifically, aqueous urea as the reducing agent is injected into the introduced exhaust gas, hydrolyzing the exhaust gas. This performs an exhaust-gas cleaning process of decreasing nitrogen oxides included in the exhaust gas. The exhaust gas subjected to the cleaning process is exhausted from the exhaust-gas discharging portion 22b to a vehicle-body horizontal outer side.

As illustrated in <FIG>, the first exhaust-gas cleaning apparatus <NUM> is supported in an attachment disposition wherein the part on the other end side, in the vehicle-body lateral width direction, is swung and displaced toward a vehicle-body front side with respect to the part on the one end side, in the vehicle-body lateral width direction, in a state wherein the exhaust-gas suctioning portion 21a is a swinging shaft. That is, the first exhaust-gas cleaning apparatus <NUM> is supported in a disposition wherein in a plan view, the longitudinal direction thereof is inclined relative to the vehicle-body lateral width direction. As illustrated in <FIG>, the exhaust-gas introduction portion 22a of the second exhaust-gas cleaning apparatus <NUM> extends diagonally backward and upward from the second exhaust-gas cleaning apparatus <NUM>. A positional relationship between the exhaust-gas discharging portion 21b of the first exhaust-gas cleaning apparatus <NUM> and the exhaust-gas introduction portion 22a of the second exhaust-gas cleaning apparatus <NUM> can be made to be a positional relationship appropriate for adopting a connecting pipe <NUM> having no bellows or other adjustment means of adjusting the positional relationship between the exhaust-gas discharging portion 21b and the exhaust-gas introduction portion 22a. This can be done by bringing the first exhaust-gas cleaning apparatus <NUM> and the second exhaust-gas cleaning apparatus <NUM> in proximity to each other in the vehicle-body longitudinal direction and by directly connecting the exhaust-gas suctioning portion 21a of the first exhaust-gas cleaning apparatus <NUM> to the exhaust-gas exhausting portion 5a of the engine <NUM>.

As illustrated in <FIG> and <FIG>, a back portion 21c of the first exhaust-gas cleaning apparatus <NUM> is positioned on a vehicle-body back side of a back end portion of the engine <NUM>. In a plan view, the back portion 21c of the first exhaust-gas cleaning apparatus <NUM> and the second exhaust-gas cleaning apparatus <NUM> overlap.

As illustrated in <FIG> and <FIG>, the partition member <NUM> that forms the partition between the engine compartment <NUM> and the driving unit <NUM> is provided across a back location of the second exhaust-gas cleaning apparatus <NUM> and a lower location of the second exhaust-gas cleaning apparatus <NUM>. The partition member <NUM> is configured so a part 17a-positioned in the lower location of the second exhaust-gas cleaning apparatus <NUM>-of the partition member <NUM> is positioned further toward a vehicle-body front side than a part 17b-positioned in the back location of the second exhaust-gas cleaning apparatus <NUM>-of the partition member <NUM>. The part 17a-positioned in the lower location of the second exhaust-gas cleaning apparatus <NUM>-of the partition member <NUM> is provided with a portion in an inclined state that, in moving toward its lower end side, is positioned more to a vehicle-body front side. A footwell of the driving unit <NUM> can be extended below the second exhaust-gas cleaning apparatus <NUM>.

As illustrated in <FIG>, electrical wires <NUM> are provided across the engine compartment <NUM> and the driving unit <NUM>. In the present embodiment, a plurality of electrical wires <NUM> is provided. However, it is also possible for only one to be provided. The electrical wires <NUM> enter from the engine compartment <NUM> into the footwell of the driving unit <NUM> by passing below a part positioned in a central portion in the vehicle-body lateral width direction of the partition member <NUM>. The electrical wires <NUM> transmit information relating to actuation of the engine <NUM> to gauges of the driving unit <NUM>. A portion of the electrical wires <NUM> that is positioned on a driving-unit side of the partition member <NUM> is wired in a state of conforming to the part 17a-positioned in the lower location of the second exhaust-gas cleaning apparatus <NUM>-of the partition member <NUM> in the footwell of the driving unit <NUM>. The electrical wires <NUM> pass through a conduit <NUM>. The conduit <NUM> is supported on the partition member <NUM> by a clamp <NUM>.

As illustrated in <FIG>, <FIG>, and <FIG>, the first exhaust-gas cleaning apparatus <NUM> and the second exhaust-gas cleaning apparatus <NUM> are supported on the vehicle body frame <NUM> via a support member <NUM>. The first exhaust-gas cleaning apparatus <NUM> and the second exhaust-gas cleaning apparatus <NUM> are supported by the vehicle body frame <NUM> in a state wherein the positional relationship between the exhaust-gas discharging portion 21b of the first exhaust-gas cleaning apparatus <NUM> and the exhaust-gas introduction portion 22a of the second exhaust-gas cleaning apparatus <NUM> is set by the support member <NUM>.

As illustrated in <FIG>, <FIG>, <FIG>, and <FIG>, the support member <NUM> is provided with a support part <NUM> that extends upward from the vehicle body frame <NUM> in a state of conforming to a front portion 22c of the second exhaust-gas cleaning apparatus <NUM> and supports the front portion 22c of the second exhaust-gas cleaning apparatus <NUM>, a support arm <NUM> that extends in a vehicle-body forward direction from an upper portion of the support part <NUM> in a state of conforming to a lower portion 21d of the first exhaust-gas cleaning apparatus <NUM> and supports the lower portion 21d of the first exhaust-gas cleaning apparatus <NUM>, and a lower support portion <NUM> that is provided to a lower portion of the support part <NUM> and supports a lower portion 22d of the second exhaust-gas cleaning apparatus <NUM>.

As illustrated in <FIG>, <FIG>, and <FIG>, the support part <NUM> has a seat portion <NUM> provided to the lower portion of the support part <NUM> and is supported on the vehicle body frame <NUM> by the seat portion <NUM> being connected to the vehicle body frame <NUM>. The connection of the seat portion <NUM> to the vehicle body frame <NUM> is performed by the flywheel housing <NUM> constituting the vehicle body frame <NUM>. The flywheel housing <NUM> is positioned below the second exhaust-gas cleaning apparatus <NUM> and can keep a length of the support part <NUM> short.

As illustrated in <FIG>, <FIG>, and <FIG>, the support part <NUM> is provided with left and right strut rods 31a lined up at an interval in the vehicle-body lateral width direction. A lower strut-portion reinforcing rod <NUM>1b, which connects lower portions of the strut rods 31a, and an upper strut-portion reinforcing rod 31c, which connects upper portions of the strut rods 31a, are provided across the left and right strut rods 31a. The left and right strut rods 31a are constituted by steel pipes.

As illustrated in <FIG>, <FIG>, and <FIG>, a front support portion 31d supporting the second exhaust-gas cleaning apparatus <NUM> is provided to each of the left and right strut rods 31a. The front portion 22c of the second exhaust-gas cleaning apparatus <NUM> is supported by the support part <NUM> by front connecting portions 22e-provided in two locations, left and right, in the front portion 22c of the second exhaust-gas cleaning apparatus <NUM>-being connected to the front support portion 31d.

As illustrated in <FIG>, <FIG>, and <FIG>, seat plates 34a provided to respective lower portions of the left and right strut rods 31a are provided to the seat portion <NUM>. In the seat portion <NUM>, the left and right seat plates 34a being connected to the flywheel housing <NUM> by a plurality of connecting bolts provides a detachable connection to the flywheel housing <NUM>.

As illustrated in <FIG>, <FIG>, and <FIG>, the lower support portion <NUM> is provided with lower support pieces 33a provided to the lower portions of the left and right strut rods 31a. The left and right lower support pieces 33a are provided to the strut rods 31a by being formed on the seat plates 34a. The lower support portion <NUM> is provided to the seat portion <NUM>. The lower portion 22d of the second exhaust-gas cleaning apparatus <NUM> is supported by the lower support portion <NUM> by lower connecting portions 22f-provided in two locations, left and right, in the lower portion 22d of the second exhaust-gas cleaning apparatus <NUM>-being connected to the lower support pieces 33a.

As illustrated in <FIG>, <FIG>, and <FIG>, the support arm <NUM> is provided with arm bodies 32a that extend in the vehicle-body forward direction from respective upper portions of the left and right strut rods 31a. An arm reinforcing rod 32b connecting the left and right arm bodies 32a is provided across distal end portions of the left and right arm bodies 32a. Among the left and right arm bodies 32a, the left arm body 32a is configured to connect via a relay member 32c to a lower connecting portion 21e provided to the lower portion 21d of the first exhaust-gas cleaning apparatus <NUM>. The right arm body 32a is configured to connect directly to the lower connecting portion 21e of the first exhaust-gas cleaning apparatus <NUM>.

As illustrated in <FIG>, <FIG>, and <FIG>, the support member <NUM> is provided with a position adjustment portion <NUM> that can adjust a support position-in the vehicle-body vertical direction, the vehicle-body longitudinal direction, and the vehicle-body lateral width direction-of the second exhaust-gas cleaning apparatus <NUM> on the support part <NUM> and with a second position adjustment portion <NUM> that can adjust a support position-in the vehicle-body vertical direction, the vehicle-body longitudinal direction, and the vehicle-body lateral width direction-of the second exhaust-gas cleaning apparatus <NUM> on the lower support portion <NUM>.

When there is a position shift between the exhaust-gas discharging portion 21b of the first exhaust-gas cleaning apparatus <NUM> and the exhaust-gas introduction portion 22a of the second exhaust-gas cleaning apparatus <NUM>, so the positional relationship between the exhaust-gas discharging portion 21b and the exhaust-gas introduction portion 22a becomes appropriate and the exhaust-gas discharging portion 21b and the exhaust-gas introduction portion 22a can be appropriately connected by the connecting pipe <NUM> having no position adjustment function, the positional relationship between the exhaust-gas discharging portion 21b and the exhaust-gas introduction portion 22a can be adjusted by the position adjustment portion <NUM> and the second position adjustment portion <NUM>.

Specifically, as illustrated in <FIG>, <FIG>, and <FIG>, the position adjustment portion <NUM> is provided with an adjustment member <NUM> positioned between the front connection portion 22e of the second exhaust-gas cleaning apparatus <NUM> and the front support portion 31d of the support part <NUM>, a first connecting bolt 36a connecting the front connecting portion 22e and the adjustment member <NUM>, and a second connecting bolt 36b connecting the front support portion 31d and the adjustment member <NUM>.

As illustrated in <FIG>, <FIG>, and <FIG>, the second position adjustment portion <NUM> is provided with a second adjustment member <NUM> positioned between the lower connecting portion 22f of the second exhaust-gas cleaning apparatus <NUM> and the lower support piece 33a of the support part <NUM>, a third connecting bolt 38a connecting the lower connecting portion 22f and the second adjustment member <NUM>, and a fourth connecting bolt 38b connecting the lower support piece 33a and the second adjustment member <NUM>.

A hole diameter of a through hole (not illustrated) of the adjustment member <NUM> into which the first connecting bolt 36a is inserted is made greater than an outer diameter of the first connecting bolt 36a for a configuration enabling position shifting of the front connecting portion 22e relative to the adjustment member <NUM>. A through hole (not illustrated) of the position adjustment member <NUM> into which the second connecting bolt 36b is inserted is made greater than an outer diameter of the second connecting bolt 36b for a configuration enabling position shifting of the adjustment member <NUM> relative to the front support portion 31d.

A hole diameter of a through hole (not illustrated) of the second adjustment member <NUM> into which the third bolt 38a is inserted is made greater than an outer diameter of the third connecting bolt 38a for a configuration enabling position shifting of the adjustment member <NUM> relative to the front support portion 31d. A hole diameter of a through hole (not illustrated) of the second adjustment member <NUM> into which the fourth connecting bolt 38b is inserted is made greater than an outer diameter of the fourth connecting bolt 38b for a configuration enabling position shifting of the adjustment member <NUM> relative to the front support portion 31d.

In the position adjustment portion <NUM>, among the first connecting bolt 36a, the second connecting bolt 36b, the third connecting bolt 38a, and the fourth connecting bolt 38b, tightening of a connecting bolt corresponding to desired position adjustment is loosened. Performing an operation of moving the second exhaust-gas cleaning apparatus <NUM> shifts the position of the second exhaust-gas cleaning apparatus <NUM> relative to the support member <NUM>. This changes the support position-in the vehicle-body vertical direction, the vehicle-body longitudinal direction, and the vehicle-body lateral width direction-of the second exhaust-gas cleaning apparatus <NUM> on the support part <NUM> in a manner corresponding to the operation that is performed of moving the second exhaust-gas cleaning apparatus <NUM>.

In the second position adjustment portion <NUM>, among the first connecting bolt 36a, the second connecting bolt 36b, the third connecting bolt 38a, and the fourth connecting bolt 38b, tightening of a connecting bolt corresponding to desired position adjustment is loosened. Performing an operation of moving the second exhaust-gas cleaning apparatus <NUM> shifts the position of the second exhaust-gas cleaning apparatus <NUM> relative to the support member <NUM>. This changes the support position-in the vehicle-body vertical direction, the vehicle-body longitudinal direction, and the vehicle-body lateral width direction-of the second exhaust-gas cleaning apparatus <NUM> on the lower support portion <NUM> in a manner corresponding to the operation that is performed of moving the second exhaust-gas cleaning apparatus <NUM>.

As illustrated in <FIG>, the driving unit <NUM> is provided behind the engine compartment <NUM>. As illustrated in <FIG>, <FIG>, and <FIG>, the driving unit <NUM> is provided with the driver's seat <NUM>, the steering wheel <NUM> whereby the steering operation of the front wheels <NUM> is performed, a left brake operation unit <NUM> whereby brakes (not illustrated) for the left back wheel are operated, and a right brake operation unit 40R whereby brakes (not illustrated) for the right back wheel are operated.

As illustrated in <FIG>, the left brake operation unit <NUM> and the right brake operation unit 40R are provided to the right and below the steering wheel <NUM>. As illustrated in <FIG>, <FIG>, and <FIG>, the left brake operation unit <NUM> and the right brake operation unit 40R are each provided with a brake pedal <NUM>, a return spring <NUM> that subjects the brake pedal <NUM> to an operation of being returned to an initial position ("off"), and a master cylinder <NUM> connected to the brake pedal <NUM>.

As illustrated in <FIG>, the brake pedal <NUM> is provided with a pedal arm 41a and with a footboard 41b provided at a lower end portion of the pedal arm 41a. A support shaft <NUM> is provided at an upper portion of the pedal arm 41a. The support shaft <NUM> is supported by a support portion <NUM> provided to the traveling vehicle body <NUM>. The brake pedal <NUM> is supported on the traveling vehicle body <NUM> in a state of being able to swing between the initial position ("off") and a braking position ("on") by using a shaft core P of the support shaft <NUM> as a swinging fulcrum. The brake pedal <NUM> is positioned to the initial position ("off") by the pedal arm 41a abutting a stopper <NUM>.

As illustrated in <FIG>, the partition member <NUM> forming the partition between the engine compartment <NUM> and the driving unit <NUM> is disposed further toward a vehicle-body front side than the brake pedal <NUM>. The return spring <NUM> is engaged to the pedal arm 41a and a spring support portion 17d provided to the partition member <NUM>. The return spring <NUM> biases the brake pedal <NUM> to swing to the initial position ("off") by using the partition member <NUM> as a counterforce member.

As illustrated in <FIG>, the partition member <NUM> is configured so the part 17a, which corresponds to the footboard 41b, of the partition member <NUM> is positioned further toward a vehicle-body front side than the part 17b, which corresponds to the support shaft <NUM>, of the partition member <NUM>. A front portion of the footwell of the driving unit <NUM> can be extended forward past the support shaft <NUM>.

As illustrated in <FIG>, the master cylinder <NUM> is provided on a vehicle-body back side of the support shaft <NUM> of the brake pedal <NUM>. The master cylinder <NUM> is fixed in a detachable manner to the support portion <NUM>. A slidable operation shaft 43a of the master cylinder <NUM> and an operation arm 41c provided to the brake pedal <NUM> are interconnected. The operation arm 41c extends from the pedal arm 41a toward an opposite side of a side whereon the footboard 41b is positioned relative to the support shaft <NUM>.

In both the left brake operation unit <NUM> and the right brake operation unit 40R, when the brake pedal <NUM> is subjected to a stepping operation against the return spring <NUM> and enters the braking position ("on"), the operation shaft 43a of the master cylinder <NUM> is subjected to a sliding operation to a pushed-in side by the operation arm 41c. The master cylinder <NUM> supplies operational hydraulic pressure to the brakes (not illustrated), and the brakes perform an operation of switching to a braking state. When the stepping operation of the brake pedal <NUM> is released, the brake pedal <NUM> is subjected to an operation of returning to the initial position ("off") by the return spring <NUM>, and the operation shaft 43a of the master cylinder <NUM> is subjected to a sliding operation to a pulled-out side by the operation arm 41c. The imparting of the operational hydraulic pressure by the master cylinder <NUM> to the brakes is released, and the brakes perform an operation of switching to an initial state.

As illustrated in <FIG> and <FIG>, the return spring <NUM> is constituted by a torsion coil spring and is provided with a coil portion 42a, an arm 42b extending from one end side of the coil portion 42a, and an arm 42c extending from another end side of the coil portion 42a. The coil portion 42a is fitted onto the support shaft <NUM>, and the return spring <NUM> is supported by the support shaft <NUM>. The arm 42b on the one end side is engaged to the spring support portion 17d of the partition member <NUM>. The arm 42c on the other end side is engaged to the pedal arm 41a.

As illustrated in <FIG>, a bent end portion 42d engaged to the pedal arm 41a is provided to the arm 42c on the other end side. A through hole <NUM> whereto the bent end portion 42d is engaged is provided to the pedal arm 41a. A shape of the through hole <NUM> is made to be a shape into which the bent end portion 42d, which moves along the shaft core P of the support shaft <NUM>, can be inserted. The return spring <NUM> and the brake pedal <NUM> can be assembled by the following assembly outline.

As illustrated in <FIG>, the coil portion 42a fits the return spring <NUM> onto the support shaft <NUM>, and the arm 42b on the one end side is placed in a state of being engaged to the partition member <NUM>. The return spring <NUM> is in a free state. The stopper <NUM> is removed from the support portion <NUM>. The brake pedal <NUM> is attached to the support shaft <NUM> and swung up, and the brake pedal <NUM> is operated in a disposition opposing the support shaft, wherein the footboard 41b is positioned in a position higher than when the brake pedal <NUM> is positioned in the initial position ("off"). The brake pedal <NUM> in this attitude of opposing the support shaft is guided to the support shaft <NUM> and moved toward the return spring <NUM>. By moving the brake pedal <NUM>, the bent end portion 42d of the return spring <NUM> moves toward the pedal arm 41a in a direction along the shaft core p of the support shaft <NUM>, is inserted into the through hole <NUM> from an inner side of the pedal arm 41a, and moves to an outer side of the pedal arm 41a. Next, the brake pedal <NUM> is swung down. At this time, the operation arm 41c enters a slit 17e provided in the partition member <NUM>. The stopper <NUM> is attached to the support portion <NUM>, and the brake pedal <NUM> is moved to the initial position ("off"). This causes the brake pedal <NUM> to be stopped by the stopper <NUM>. As illustrated in <FIG>, the bent end portion 42d engages to the pedal arm 41a, the return spring <NUM> is provided with an elastic restoring force, and the brake pedal <NUM> enters a state of being biased and swung to the initial position ("off") by the return spring <NUM>. The slit 17e is closed off once assembly of the brake pedal <NUM> is finished.

The steering wheel <NUM> is supported in a state of being able to change positions in the vehicle-body longitudinal direction and the vehicle-body vertical direction. As illustrated in <FIG>, a steering-post cover <NUM> is inserted into a through hole <NUM> of a panel cover <NUM> supported on the traveling vehicle body <NUM>. When the steering wheel <NUM> changes positions in the vehicle-body longitudinal direction, the steering-post cover <NUM> follows the steering wheel <NUM> and swings in the vehicle-body longitudinal direction relative to the panel cover <NUM>. A bellows-shaped expandable cover <NUM> is connected across a proximal-side lower portion of the steering-post cover <NUM> and a lower portion 51a of the panel cover <NUM>. The expandable cover <NUM> expands and contracts according to the swinging of the steering-post cover <NUM> but, regardless of the swinging of the steering-post cover <NUM>, places a gap between the steering-post cover <NUM> and the lower portion 51a of the panel cover <NUM> in a closed state. Between a part opposing a distal-side wall portion of the steering-post cover <NUM> of the panel cover <NUM> and the distal-side wall portion of the steering-post cover <NUM>, a gap that allows the steering-post cover <NUM> to swing is provided. However, above the gap and on the distal-side wall portion of the steering-post cover <NUM>, a bulging portion that bulges toward a cover outer side and makes the gap difficult to see from above is provided. In the panel cover <NUM>, a face portion 51b corresponding to a side portion of the steering-post cover <NUM> is raised to the proximal side. Even if the steering-post cover <NUM> swings, the face portion 51b makes it difficult to see the gap between the steering-post cover <NUM> and the panel cover <NUM> on a horizontal side of the steering-post cover <NUM>.

Claim 1:
A tractor comprising:
a vehicle body (<NUM>);
an engine bonnet (<NUM>) forming an engine compartment (<NUM>);
an engine (<NUM>) disposed in the engine compartment (<NUM>);
a first exhaust-gas cleaning apparatus (<NUM>) configured to clean exhaust gas discharged from the engine (<NUM>) and disposed in the engine compartment (<NUM>) above the engine (<NUM>) such that a longitudinal direction of the first exhaust-gas cleaning apparatus (<NUM>) is substantially parallel to a vehicle-body lateral width direction;
a second exhaust-gas cleaning apparatus (<NUM>) configured to clean exhaust gas discharged from the engine (<NUM>) and disposed in the engine compartment (<NUM>) behind the engine (<NUM>) such that a longitudinal direction of the second exhaust-gas cleaning apparatus (<NUM>) is substantially parallel to the vehicle-body lateral width direction;
a vehicle body frame (<NUM>); and
a support member (<NUM>) supported by the vehicle body frame (<NUM>) and supporting the first exhaust-gas cleaning apparatus (<NUM>) and the second exhaust-gas cleaning apparatus (<NUM>),
wherein the support member (<NUM>) comprises a support part (<NUM>) extending upward from the vehicle body frame (<NUM>) along a front portion of the second exhaust-gas cleaning apparatus (<NUM>) while supporting the front portion, and a support arm (<NUM>) extending forward from an upper portion of the support part (<NUM>) along a lower portion of the first exhaust-gas cleaning apparatus (<NUM>) while supporting the lower portion.