Patent Description:
In some of conventional tractors as working vehicles, a plurality of working system operating means for setting and adjusting operation states of a traveling machine body and a rotary cultivator are collectively arranged on an upper surface of an arm rest which is arranged on at least one of right and left sides of a cockpit. Patent Document <NUM> discloses one example of a tractor having such a configuration. In the tractor of Patent Document <NUM>, an working machine elevating lever (working unit position lever) which is working system operating means is arranged on an arm rest located on a right side of a cockpit in a traveling direction, and a throttle lever (main transmission lever) which is traveling system operating means is arranged on an outer side of the arm rest with respect to the cockpit.

According to the configuration of Patent Document <NUM>, however, since the traveling system operating means is arranged at a position separated away from the cockpit, it is necessary for an operator to largely move his or her hand from a steering wheel whenever a traveling speed of the working vehicle is changed, and operability of the working vehicle is poor. Further, although the working system operating means are arranged on the arm rest, the traveling system operating means is arranged on the outer side of the arm rest. Therefore, when the operator operates the traveling system operating means, the operator needs to move at least an elbow and onward, and the arm rest hinders depending upon an operating attitude.

In view of the above problem, it is an object of the present invention to reliably maintain original functions of an arm rest (rest arm function) while keeping a state where an operator's hand can easily reach various operating means.

A first aspect of the present invention is defined in claim <NUM>.

According to a second aspect of the invention, in the working vehicle of the first aspect, the main transmission lever projects front the front end of the arm rest on the side of the cockpit, and a front surface of the arm rest is formed into a curved surface corresponding to a turning locus of the main transmission lever.

According to a third aspect of the invention, in the working vehicle of any one of the first or second aspects, a rear portion of the arm rest is parallel to the cockpit, and a front portion of the arm rest is separated from the cockpit toward a front end.

According to a fourth aspect of the invention, in the working vehicle of any one of the first to third aspects, arranged on the upper surface of the arm rest at a position behind the main transmission lever and on the side of the cockpit are a setting dial for setting a value of maximum speed of the traveling speed or a maximum rotation number of the engine, and a selecting switch for selecting whether the value set by the setting dial is the maximum speed of the traveling speed and the maximum rotation number of the engine.

According to the invention of the present application, a main transmission lever for changing traveling speed by the traveling unit is arranged on a front end of the arm rest close to the cockpit, and an elevating dial for hoisting and lowering the working unit is arranged on a side surface of the arm rest on an opposite side from the cockpit. Therefore, positions where the traveling system operating means and the working system operating means are arranged are close to the operator, and operability of the traveling system operating means and the working system operating means is excellent. The main transmission lever of the traveling system operating means is formed as a lever type operating tool, and the elevating dial of the working system operating means is formed as a dial type operating tool. Thus, even when the operator operates the working vehicle, it is easy to discriminate between the traveling system operating means and the working system operating means, and wrong operation can be prevented.

Further, the main transmission lever projects front the front end of the arm rest on the side of the cockpit, and a front surface of the arm rest is formed into a curved surface corresponding to a turning locus of the main transmission lever. Therefore, since the operator's hand grasping an upper end (grasping portion) of the main transmission lever does not come into contact with the arm rest, the operator can smoothly operate the main transmission lever.

Further, the elevating dial is fitted to a side surface of the arm rest such that an upper end of the elevating dial is located lower than an upper surface of the arm rest, a side notch for operating a dial is provided in the side surface of the arm rest above an installation region of the elevating dial, an operating projection is provided above the elevating dial, and front and rear step portions of the side notch are brought into abutment against the operating projection, thereby configuring the step portions as a rotation-restricting portion which restricts rotation of the elevating dial. Therefore, when the main transmission lever is operated, it is possible to prevent the operator from unintentionally touching the elevating dial, and when the elevating dial is operated, it is possible to restrict the rotation region within a predetermined width, and it is possible to prevent the operator from excessively operating the elevating dial.

Further, a rear portion of the arm rest is parallel to the cockpit, and a front portion of the arm rest is separated from the cockpit toward a front end. Therefore, there are effects that the operability (handling performance) of the traveling system operating means and the working system operating means are excellent, and it is possible to reliably support the operator's arm while preventing the operator's knee from touching the operating means.

Further, arranged on the upper surface of the arm rest at a position behind the main transmission lever and on the side of the cockpit are a setting dial for setting a value of maximum speed of the traveling speed or a maximum rotation number of the engine, and a selecting switch for selecting whether the value set by the setting dial is the maximum speed of the traveling speed and the maximum rotation number of the engine. Therefore, since the main transmission lever, the setting dial and the selecting switch which are the traveling system operating means are collectively arranged close to the operator in the cockpit, and operability (handling performance) thereof is excellent.

Embodiments in which the invention of the present application is applied to a tractor as a working vehicle will be described based on the drawings (<FIG>). <FIG> is a left side view of the tractor, <FIG> is a plan view of the tractor, <FIG> is a block diagram showing an outline of a power transmission system, <FIG> is a function block diagram of a controller, <FIG> is a plan view of a cabin, <FIG> is a left side view of the cabin, <FIG> is a plan view of an arm rest, <FIG> is a left side view of the arm rest, and <FIG> is a right side view of the arm rest. Illustration of the cabin is omitted from <FIG> for convenience sake.

First, the outline of the tractor will be described with reference to <FIG> and <FIG>. A traveling machine body <NUM> of the tractor <NUM> of the embodiment is supported by a pair of right and left front wheels <NUM> and a pair of right and left rear wheels <NUM> as traveling units. The tractor <NUM> runs forward and rearward by driving the rear wheels <NUM> and the front wheels <NUM> by a common-rail type diesel engine <NUM> (engine, hereinafter) as a power source provided in a front portion of the traveling machine body <NUM>. The engine <NUM> is covered with a hood <NUM>. A cabin <NUM> is arranged on an upper surface of the traveling machine body <NUM>, and a cockpit <NUM> and a steering handle (circular handle) <NUM> are arranged in the cabin <NUM>. By steering the steering handle <NUM>, a steering direction of the front wheels <NUM> is moved rightward and leftward. A fuel tank <NUM> for supplying fuel to the engine <NUM> is provided at a location lower than a bottom of the cabin <NUM>.

In an engine room covered with the hood <NUM>, an exhaust side of the engine <NUM> is connected to a continuously regenerative exhaust gas purification device <NUM> (diesel particulate filter). The exhaust gas purification device <NUM> includes a diesel oxidation catalyst such as platinum which produces nitrogen dioxide (NO2), and a soot filter of honeycomb structure which continuously oxidizes and removes collected particulate material (PM, hereinafter) at relatively low temperature. That is, the exhaust gas purification device <NUM> has such a configuration that diesel oxidation catalyst and the soot filter are arranged in a cylindrical purification casing in series in a moving direction of exhaust gas, and the exhaust gas purification device <NUM> removes PM in exhaust gas of the engine <NUM>, and reduces carbon monoxide (CO) and hydrocarbon (HC) in exhaust gas.

The traveling machine body <NUM> is composed of an engine frame <NUM> having a front bumper <NUM> and a front axle case <NUM>, and right and left machine body frames <NUM> detachably fixed to a rear portion of the engine frame <NUM> with bolts. Rear portions of the machine body frames <NUM> are provided with a transmission case <NUM> for appropriately speed-changing rotation power and transmitting the rotation power to the front and rear four wheels <NUM>, <NUM>, <NUM> and <NUM>. The rear wheels <NUM> are mounted on the transmission case <NUM> through a rear axle case <NUM> which is mounted such that it projects outward from an outer surface of the transmission case <NUM>. Upper portions of the right and left rear wheels <NUM> are covered with fenders <NUM> which are fixed to the machine body frames <NUM>.

A hydraulic elevating mechanism <NUM> which hoists and lowers a rotary cultivator <NUM> as a working unit is detachably mounted on an upper surface a rear portion of the transmission case <NUM>. The rotary cultivator <NUM> is connected to a rear portion of the transmission case <NUM> through a three-link mechanism which is composed of a pair of right and left lower links <NUM> and a top link <NUM>. A PTO shaft <NUM> for transmitting a PTO driving force to the rotary cultivator <NUM> projects rearward from a rear surface of the transmission case <NUM>.

As shown in <FIG>, a flywheel <NUM> is mounted on an engine output shaft <NUM> such that the flywheel <NUM> is directly coupled to the engine output shaft <NUM>. The engine output shaft <NUM> projects rearward from a rear surface of the engine <NUM>. A main power shaft <NUM> which is connected to the flywheel <NUM> through a main clutch <NUM> and which extends rearward is connected to a main transmission input shaft <NUM> which projects forward from the transmission case <NUM> through a stretching-type power transmission shaft <NUM>. Both ends of the power transmission shaft <NUM> include universal shaft joints. As shown in <FIG>, a front wheel transmission shaft (not shown) which projects rearward from the front axle case <NUM> and a front wheel output shaft (not shown) which projects forward from a front surface of the transmission case <NUM> are connected to each other through a front wheel driving shaft <NUM>.

A hydraulic continuously variable transmission <NUM>, a forward/backward switching mechanism <NUM>, a traveling auxiliary transmission gear mechanism <NUM> and a differential gear mechanism <NUM> are arranged in the transmission case <NUM>. Rotation power of the engine <NUM> is transmitted to the main transmission input shaft <NUM> of the transmission case <NUM> through the power transmission shaft <NUM>, and is appropriately speed-changed by the hydraulic continuously variable transmission <NUM> and a traveling auxiliary transmission gear mechanism <NUM>. This speed-changed power is transmitted to the right and left rear wheels <NUM> through the differential gear mechanism <NUM>. The speed-changed power is transmitted to the front axle case <NUM> through the front wheel driving shaft <NUM> and is transmitted also to the right and left front wheels <NUM>.

The hydraulic continuously variable transmission <NUM> is of an inline type in which the main transmission output shaft <NUM> is concentrically arranged with respect to the main transmission input shaft <NUM>, and includes a variable capacity hydraulic pump unit <NUM> and a constant capacity transmission hydraulic motor <NUM> which is operated with high pressure hydraulic oil discharged from the hydraulic pump unit <NUM>. The hydraulic pump unit <NUM> is provided with a pump swash plate <NUM> which can change its inclination angle with respect to an axis of the main transmission input shaft <NUM> to adjust a supply amount of the hydraulic oil. A main transmission hydraulic cylinder which changes and adjusts the inclination angle of the pump swash plate <NUM> with respect to the axis of the main transmission input shaft <NUM> is associated with the pump swash plate <NUM>. By changing the inclination angle of the pump swash plate <NUM> by driving the main transmission hydraulic cylinder (not shown), an amount of hydraulic oil supplied from the hydraulic pump unit <NUM> to the hydraulic motor <NUM> is changed and adjusted, and a main transmission operation of the hydraulic continuously variable transmission <NUM> is carried out.

That is, if a switching valve (not shown) is operated with hydraulic oil from a proportional control valve <NUM> (see <FIG>) which operates in proportion to an operation amount of a main transmission lever <NUM> (details thereof will be described later), the main transmission hydraulic cylinder (not shown) is driven, and then the inclination angle of the pump swash plate <NUM> with respect to the axis of the main transmission input shaft <NUM> is changed. The angle of the pump swash plate <NUM> of this embodiment is set such that the angle can be adjusted in a range between one of (positive) maximum inclination angles and the other (negative) maximum inclination angle both sandwiching a neutral angle of a substantially zero inclination (including zero or in the vicinity of zero), and the pump swash plate <NUM> is inclined to one of the maximum inclination angles (negative angle in this case, and the inclination angle is close to the maximum angle) when vehicle speed of the traveling machine body <NUM> is minimum.

When the inclination angle of the pump swash plate <NUM> is substantially zero (neutral angle), the hydraulic motor <NUM> is not driven by the hydraulic pump unit <NUM>, and a main transmission output shaft <NUM> rotates substantially at the same rotation speed as the main transmission input shaft <NUM>. When the pump swash plate <NUM> is inclined toward one direction (positive inclination angle) with respect to the axis of the main transmission input shaft <NUM>, the hydraulic pump unit <NUM> accelerates and operates the hydraulic motor <NUM>, and the main transmission output shaft <NUM> rotates at speed higher than that of the main transmission input shaft <NUM>. As a result, rotation speed of the hydraulic motor <NUM> is added to rotation speed of the main transmission input shaft <NUM>, and the rotation speed is transmitted to the main transmission output shaft <NUM>. Hence, speed-changed power (vehicle speed) from the main transmission output shaft <NUM> is changed in proportion to the inclination angle (positive inclination angle) in a range of rotation speed higher than that of the main transmission input shaft <NUM>. When the inclination angle of the pump swash plate <NUM> is positive and in the vicinity of the maximum angle, the vehicle speed of the traveling machine body <NUM> becomes the highest.

When the pump swash plate <NUM> is inclined in the other direction (negative inclination angle) with respect to the axis of the main transmission input shaft <NUM>, the hydraulic pump unit <NUM> decelerates speed and operates (reversely rotates) the hydraulic motor <NUM>, and the main transmission output shaft <NUM> rotates at rotation speed lower than that of the main transmission input shaft <NUM>. As a result, the rotation speed of the hydraulic motor <NUM> is subtracted from the rotation speed of the main transmission input shaft <NUM>, and the rotation speed is transmitted to the main transmission output shaft <NUM>. Hence, speed-changed power from the main transmission output shaft <NUM> is changed in proportion to the inclination angle (negative inclination angle) of the pump swash plate <NUM> in a range of rotation speed lower than that of the main transmission input shaft <NUM>. When the inclination angle of the pump swash plate <NUM> is negative and in the vicinity of the maximum angle, thee vehicle speed of the traveling machine body <NUM> becomes minimum.

The forward/backward switching mechanism <NUM> receives rotation power from the main transmission output shaft <NUM> of the hydraulic continuously variable transmission <NUM>. The forward/backward switching mechanism <NUM> includes a forward gear (not shown) and a reverse gear (not shown) for switching the forward/backward movements of the traveling machine body <NUM>, and one of the forward gear and the reverse gear is selected and rotated by forward and reverse hydraulic clutches (not shown), thereby transmitting the power to an auxiliary transmission mechanism <NUM>. At this time, in a neutral state where a forward/backward switching mechanism lever <NUM> is not inclined in any direction, both the forward and reverse hydraulic clutches (not shown) are brought into a power interruption state. Rotation power sent from the main transmission output shaft <NUM> toward the front and rear wheels <NUM> and <NUM> becomes substantially zero (the same state where main clutch <NUM> is OFF).

A forward clutch solenoid valve <NUM> (see <FIG>) is driven by a forward inclining operation of the forward/backward switching mechanism lever <NUM> (see <FIG>), and a forward clutch cylinder (not shown) is operated. Thus, rotation power caused by the main transmission output shaft <NUM> is transmitted to the auxiliary transmission mechanism <NUM> through the forward gear (not shown) in the forward/backward switching mechanism <NUM>. A reverse clutch solenoid valve <NUM> (see <FIG>) is driven by a reverse inclining operation of the forward/backward switching mechanism lever <NUM>, and a reverse clutch cylinder (not shown) is operated. Thus, rotation power caused by the main transmission output shaft <NUM> is transmitted to the auxiliary transmission mechanism <NUM> through the reverse gear (not shown) in the forward/backward switching mechanism <NUM>.

The auxiliary transmission mechanism <NUM> receives rotation power from the forward/backward switching mechanism <NUM>, speed-changes and outputs rotation power which is sent through the forward/backward switching mechanism <NUM>. The auxiliary transmission mechanism <NUM> includes an auxiliary transmission low speed gear (not shown) and an auxiliary transmission high speed gear (not shown), the auxiliary transmission mechanism <NUM> selects one of the low speed gear and the high speed gear and rotates the same by a low speed clutch (not shown) and a high speed clutch (not shown) and thus, the auxiliary transmission mechanism <NUM> changes speed of rotation power from the forward/backward switching mechanism <NUM>, and transmits the rotation power to mechanisms of a rear stage.

By inclining an auxiliary transmission lever <NUM> (see <FIG>) toward a low speed side, a position of a piston rod of an auxiliary transmission hydraulic cylinder (not shown) is displaced toward the low speed side in accordance with switching action of a high speed clutch solenoid valve <NUM> (see <FIG>). Therefore, an auxiliary transmission shifter (not shown) which is connected to a tip end of the piston rod of the auxiliary transmission hydraulic cylinder (not shown) brings a low speed clutch (not shown) into a power connecting state, speed of rotation power from the forward/backward switching mechanism <NUM> is changed to low speed, and the rotation power is transmitted to the differential gear mechanism <NUM>.

By inclining the auxiliary transmission lever <NUM> toward a high speed side, the position of the piston rod of the auxiliary transmission hydraulic cylinder (not shown) is displaced toward the high speed side in accordance with the switching action of the high speed clutch solenoid valve <NUM> (see <FIG>). Therefore, the auxiliary transmission shifter (not shown) brings the high speed clutch (not shown) into the power connecting state, speed of the rotation power from the forward/backward switching mechanism <NUM> is changed to high speed, and the rotation power is transmitted to the differential gear mechanism <NUM>.

The differential gear mechanism <NUM> receives rotation power from the auxiliary transmission mechanism <NUM>, and transmits speed-changed power which is speed-changed by the auxiliary transmission mechanism <NUM> to the right and left rear wheels <NUM>. At this time, the differential gear mechanism <NUM> transmits (differential action) the speed-changed power which is speed-changed by the auxiliary transmission mechanism <NUM> separately to differential output shafts <NUM> which extend in lateral directions by a differential gear (not shown). The differential output shafts <NUM> are connected to rear axles <NUM> through final gears <NUM> and the like, and the rear wheels <NUM> are mounted on tip ends of the rear axles <NUM>. Brake operating mechanisms 65a and 65b are associated with the differential output shafts <NUM>, and the brake operating mechanisms 65a and 65b carry out braking action by a depressing operation of brake pedals <NUM> (see <FIG>) located on a right side of a steering column <NUM>.

If a steering angle of the steering handle <NUM> (see <FIG> and <FIG>) becomes equal to or greater than a predetermined angle, an automatic brake solenoid valve 67a (67b) corresponding to inner one of the rear wheels <NUM> in terms of turning action is driven to operate a brake cylinder (not shown), and the brake operating mechanism 65a (65b) corresponding to the inner one of the rear wheels <NUM> in terms of turning action automatically carries out braking action. Hence, the tractor can turn in a small radius (U-turn). The differential gear mechanism <NUM> includes a differential locking mechanism (not shown) for stopping the differential action (driving right and left differential output shafts <NUM> always at equal speed). In this case, by engaging a lock pin provided such that the pin can come in and out with the differential gear by a depressing operation of a differential locking pedal <NUM> (see <FIG>), the differential gear is fixed, a differential function stops, and the right and left differential output shafts <NUM> are rotated and driven at equal speed.

The transmission case <NUM> of the above-described configuration is provided therein with a PTO transmission gear mechanism (not shown) for switching driving speed of the PTO shaft <NUM>, and a PTO clutch (not shown) which can transmit power and shut off the transmission of power between the main transmission input shaft <NUM> and the PTO transmission gear mechanism. By the action of the PTO transmission gear mechanism and the PTO clutch, power from the engine <NUM> is transmitted to the PTO shaft <NUM>.

In this case, if a later-described PTO clutch switch <NUM> is turned ON, a PTO clutch hydraulic solenoid valve <NUM> (see <FIG>) is driven, and the PTO clutch is brought into a power connected state. As a result, rotation power from the engine <NUM> transmitted through the main transmission input shaft <NUM> is output from a PTO gear mechanism (not shown) toward the PTO shaft <NUM>. At this time, if a speed-changing operation is carried out for the PTO transmission lever <NUM>, speed-changing output of the PTOs of first speed to fourth speed and reverse is transmitted to the PTO shaft <NUM> by selecting one of the plurality of gears in the PTO transmission gear mechanism (not shown) and rotating the gear.

Next, a configuration for executing the various control operations (speed-changing control, automatic horizontal control, cultivate-depth automatic control) will be described with reference to <FIG>. As shown in <FIG>, the tractor <NUM> includes an engine controller <NUM> which controls a driving operation of the engine <NUM>, a meter controller <NUM> which controls display action of a meter panel <NUM> provided on a steering column (steering column) <NUM>, a body controller <NUM> which controls speed of the traveling machine body <NUM>, and a working machine controller <NUM> which controls a state of the rotary cultivator <NUM>.

Each of the controllers <NUM> to <NUM> includes a CPU which executes various computation processing and control, a ROM for storing a control program and data, a RAM for temporarily storing a control program and data, a timer for measuring time, and an I/O interface. The controllers <NUM> to <NUM> are connected to each other through a CAN communication bus <NUM> such that the controllers can communicate with each other. The engine controller <NUM> and the meter controller <NUM> are connected to a battery <NUM> through a power supply application key switch <NUM>. The key switch <NUM> is a rotary switch which can be rotated and operated by a predetermined key inserted into a key hole, and the key switch <NUM> is mounted on the steering column <NUM> located in front of the cockpit <NUM>.

Connected to an input side of the engine controller <NUM> are a rail pressure sensor <NUM> which detects pressure of fuel in a common-rail of the engine <NUM>, an engine rotation sensor <NUM> which detects rotation speed (cam shaft position of crankshaft) of the engine <NUM>, a cooling water temperature sensor <NUM> which detects temperature of cooling water of the engine <NUM>, a fuel temperature sensor <NUM> which detects temperature of fuel in the common-rail of the engine <NUM>, a differential pressure sensor <NUM> which detects differential pressure of exhaust gas before and after (upstream and downstream) of the soot filter in the exhaust gas purification device <NUM>, and a DPF temperature sensor <NUM> which detects temperature of exhaust gas in the exhaust gas purification device <NUM>.

With this configuration, the engine controller <NUM> controls a fuel pump <NUM> and fuel injection valves <NUM> of the engine <NUM>. That is, fuel in a fuel tank (not shown) is sent to the common-rail (not shown) by the fuel pump <NUM> under pressure, and the fuel is accumulated in the common-rail as high pressure fuel. By (electronically) controlling an opening/closing state of the fuel injection valves <NUM>, injection pressure, injection timing and injection period (injection amount) of high pressure fuel in the common-rail (not shown) are controlled, and the fuel is injected from the injector into the cylinders of the engine <NUM>. Hence, it is possible to reduce nitrogen oxide (NOx) discharged from the engine <NUM>, and to reduce noise and vibration of the engine <NUM>.

Connected to an input side of the meter controller <NUM> are a steering potentio <NUM> which detects a turning amount (steering angle) of the steering handle <NUM>, a display change-over switch <NUM> for switching between display states of a liquid crystal panel <NUM>, and a regeneration switch <NUM> as an input member which permits regeneration action of the exhaust gas purification device <NUM>. Connected to an output side of the meter controller <NUM> are the liquid crystal panel <NUM> in the meter panel <NUM>, a warning buzzer <NUM> which sounds in association with regeneration action of the exhaust gas purification device <NUM>, and a regeneration lamp <NUM> as a warning lamp which twinkles in association with regeneration action of the exhaust gas purification device <NUM>.

Connected to an input side of the body controller <NUM> are a forward/backward movement potentio <NUM> which detects an operation position of the forward/backward switching mechanism lever <NUM>, a main transmission output shaft rotation sensor <NUM> which detects the output rotation number of the main transmission output shaft <NUM>, a vehicle speed sensor <NUM> which detects the rotation speeds (traveling auxiliary speeds) of the front and rear wheels <NUM> and <NUM>, a brake pedal switch <NUM> which detects whether the brake pedals <NUM> are depressed, an automatic brake switch <NUM> for switching between the automatic brake solenoid valves 67a and 67b, a main transmission potentio <NUM> which detects an operation position of a main transmission lever <NUM>, a rotation number/vehicle speed setting dial <NUM>, a rotation number/vehicle speed selecting switch <NUM> and a mode change-over switch <NUM>.

Connected to an output side of the body controller <NUM> are the forward clutch solenoid valve <NUM> for operating the forward clutch cylinder (not shown), the reverse clutch solenoid valve <NUM> for operating the reverse clutch cylinder (not shown), the high speed clutch solenoid valve <NUM> for operating the auxiliary transmission hydraulic cylinder (not shown), the proportional control valve <NUM> for operating the main transmission hydraulic cylinder (not shown) in proportion to an inclination operation amount of the main transmission lever <NUM>, and the automatic brake solenoid valves 67a and 67b for respectively operating the left and right brake operating mechanisms 65a and 65b.

Connected to an input side of the working machine controller <NUM> are a pendulum type rolling sensor <NUM> which detects a lateral inclination angle of the traveling machine body <NUM>, a potentio meter type working unit position sensor <NUM> which detects a lateral inclination angle of the rotary cultivator <NUM> relative to the traveling machine body <NUM>, a potentio meter type lift angle sensor <NUM> which detects a turning angle of a lift arm (not shown) which connects the hydraulic elevating mechanism <NUM> and the right and left lower links <NUM> to each other, a potentio meter type rear cover sensor <NUM> which detects a vertically turning angle of a cultivating rear cover <NUM> (see <FIG> and <FIG>) which vertically turns when a cultivating depth of the rotary cultivator <NUM> is changed, a position dial sensor <NUM> which detects an operating position of a working unit position dial <NUM> which manually changes and adjusts a height position of the rotary cultivator <NUM>, a cultivating depth setting dial <NUM>, the PTO clutch switch <NUM>, an inclination manual switch <NUM>, an automatic elevating switch <NUM>, an elevation finely adjusting switch <NUM>, an inclination setting dial <NUM>, a most-hoisted position setting dial <NUM> and a lowering speed setting dial <NUM>.

Connected to an output side of the working machine controller <NUM> are the PTO clutch hydraulic solenoid valve <NUM> which operates the PTO clutch <NUM> (not shown), and a control solenoid valve <NUM> for supplying hydraulic oil to a single acting type hydraulic cylinder (not shown) of the hydraulic elevating mechanism <NUM>.

The cockpit <NUM> and a structure around the cockpit <NUM> will be described with reference to <FIG> and <FIG>. The steering column <NUM> surrounding a rear side of the engine <NUM> is arranged in front of the cockpit <NUM> in the cabin <NUM>. The steering handle <NUM> is substantially circular as viewed from above. The steering handle <NUM> is mounted on an upper portion of a handle shaft which projects from an upper surface of the steering column <NUM>. Therefore, a substantially ring-shaped steering wheel <NUM> in the steering handle <NUM> inclines diagonally rearward and downward with respect to a horizontal direction.

A throttle lever <NUM> for setting the output rotation number of the engine <NUM>, and the pair of right and left brake pedals <NUM> for braking the traveling machine body <NUM> are arranged on a right side of the steering column <NUM>. The forward/backward switching mechanism lever <NUM> for switching a moving direction of the traveling machine body <NUM> between forward movement and rearward movement, and a clutch pedal <NUM> for turning off the main clutch <NUM> which transmits power and shuts off the transmission of power are arranged on a left side of the steering column <NUM>. A parking brake lever <NUM> for keeping the right and left brake pedals <NUM> at depressed positions is arranged on a back surface side of the steering column <NUM>.

An accelerator pedal <NUM> is arranged on a floor place <NUM> in the cabin <NUM> on a right side of the steering column <NUM>. The engine rotation number which is set by the throttle lever <NUM> is defined as a minimum rotation number, and the accelerator pedal <NUM> accelerates and decelerates the engine rotation number within a range equal to or higher than the minimum rotation number. The PTO transmission lever <NUM> for switching the driving speed of the later-described PTO shaft <NUM>, and the differential locking pedal <NUM> for rotating and driving the right and left rear wheels <NUM> at equal speed are arranged below the cockpit <NUM>. The auxiliary transmission lever <NUM> for switching an output range of the traveling auxiliary transmission gear mechanism <NUM> (see <FIG>) between low speed and high speed is arranged on a left side of the cockpit <NUM>.

An arm rest <NUM> on which an arm or an elbow of an operator sitting on the cockpit <NUM> is put is provided on a right side of the cockpit <NUM>. The arm rest <NUM> is a separate member from the cockpit <NUM>. The arm rest <NUM> includes a main transmission lever <NUM> which is the traveling system operating means, and the working unit position dial (elevating dial) <NUM> which is the working system operating means. The main transmission lever <NUM> can incline forward and rearward as a main transmission operating body. In this embodiment, when the main transmission lever <NUM> is operated to incline forward, vehicle speed of the traveling machine body <NUM> is increased, and when the main transmission lever <NUM> is operated to incline rearward, the vehicle speed of the traveling machine body <NUM> is reduced. The working unit position dial <NUM> is of a dial type for manually changing and adjusting a height position of the rotary cultivator <NUM>.

A rear portion of a lower end of the arm rest <NUM> is pivotally attached to a bracket (not shown) which stands on a seat frame (not shown) on which the cockpit <NUM> is arranged for example such that the arm rest <NUM> can vertically turn and flip up with respect to the bracket. The arm rest <NUM> is configured such that its turning attitude caused by the vertical turning motion can be adjusted in a plurality of stages (four stages in this embodiment). It is also possible to employ such a configuration that the arm rest <NUM> is independent from longitudinal sliding motion of the cockpit <NUM>, and the position of the arm rest <NUM> can be adjusted (longitudinally slidable) along the moving direction (longitudinal direction) of the traveling machine body <NUM>.

If the above-described vertically turnable configuration is employed, it is possible to adjust a turning attitude of the arm rest <NUM> in stages in accordance with a physical size and a working attitude of an operator sitting on the cockpit <NUM>. Therefore, it is possible to set the arm rest <NUM> such that it can reliably support an arm of the operator and the arm rest does not touch an elbow of the operator. Further, when the arm rest <NUM> is configured such that its longitudinally sliding position can be adjusted, it is effective to reduce fatigue of the operator caused by long time working in cooperation with the longitudinal sliding position adjusting function of the cockpit <NUM> and the vertically turnable configuration of the arm rest <NUM>.

An operation stage <NUM> provided with various kinds of operating means is fixed to a right side of the arm rest <NUM> above the fenders <NUM>. The cultivating depth setting dial <NUM>, the PTO clutch switch <NUM> and the inclination manual switch <NUM> are arranged on an upper surface of the operation stage <NUM>. The cultivating depth setting dial <NUM> is of a dial type for presetting a target cultivating depth of the rotary cultivator <NUM>. The PTO clutch switch <NUM> is for turning the PTO clutch <NUM> ON and OFF to transmit power from the PTO shaft <NUM> to the rotary cultivator <NUM> and to shut off the transmission of power. The inclination manual switch <NUM> is for manually changing and adjusting a lateral inclination angle of the rotary cultivator <NUM>.

The PTO clutch switch <NUM> is a push switch in which if the PTO clutch switch <NUM> is rotated in a clockwise direction as viewed from above while once pressing down the switch, the PTO clutch switch <NUM> is locked at the pushed down position, the power transmission from the PTO shaft <NUM> to the rotary cultivator <NUM> is brought into a connection state, and if the PTO clutch switch <NUM> is again pressed down, the switch returns to its original position, and the power transmission from the PTO shaft <NUM> to the rotary cultivator <NUM> is brought into a shut-off state. The inclination manual switch <NUM> is a self-reset type (momentary type) lever switch which is inclined in the lateral direction and only when the inclination manual switch <NUM> is operated, the lateral inclination angle of the rotary cultivator <NUM> is changed.

A detailed structure of the arm rest <NUM> according to a first embodiment will be described with reference to <FIG>. The arm rest <NUM> includes a base (arm rest rear portion) <NUM> which extends long in the longitudinal direction, and an extending portion (arm rest front portion) <NUM> which extends forward from the base <NUM>. The extending portion <NUM> is arranged such that it bends in a direction (right direction in this embodiment) separating away from the cockpit <NUM> with respect to the base <NUM> which extends in parallel to the cockpit <NUM>, and the arm rest <NUM> is formed into a substantially L-shape as a whole as viewed from above.

As shown in <FIG> and <FIG>, the arm rest <NUM> includes a front notch <NUM> in a front end of the extending portion <NUM> on the side of the cockpit <NUM>. The front notch <NUM> is recessed downward from an upper surface of the extending portion <NUM>. The main transmission lever <NUM> projects from an upper surface of the front notch <NUM>. The extending portion <NUM> includes a step portion <NUM> on the side of the cockpit <NUM> behind the front notch <NUM> (on connection side with base <NUM>). The step portion <NUM> recesses downward from the upper surface of the extending portion <NUM>. The later-described rotation number/vehicle speed setting dial (setting dial) <NUM> and the later-described rotation number/vehicle speed selecting switch (selecting switch) <NUM> are arranged on an upper surface of the step portion <NUM>.

The height position of an upper surface of the step portion <NUM> is higher than the upper surface of the front notch <NUM> and lower than an upper surface of the base <NUM>. Thus, even if an operator puts the arm or elbow on the base <NUM> of the arm rest <NUM> and operates the main transmission lever <NUM> in front of the extending portion <NUM>, it is possible to reduce fear that the arm or elbow unintentionally touches the setting dial <NUM> and the selecting switch <NUM> of the step portion <NUM>. Therefore, it is possible to remarkably reduce or prevent a wrong operation of the setting dial <NUM> and the selecting switch <NUM>.

The rotation number/vehicle speed setting dial <NUM> is for presetting maximum rotation speed of the engine <NUM> or maximum travelling speed of the traveling machine body <NUM>. The rotation number/vehicle speed selecting switch <NUM> is for designating whether a value which is set by the rotation number/vehicle speed setting dial <NUM> is the maximum rotation speed of the engine <NUM> or the maximum traveling speed of the traveling machine body <NUM>. The rotation number/vehicle speed selecting switch <NUM> is composed of a position-keeping type (alternate type) switch (position-keeping type rocker switch in example of this embodiment). Thus, if the rotation number/vehicle speed selecting switch <NUM> designates the rotation speed, the rotation number/vehicle speed setting dial <NUM> sets the maximum rotation speed of the engine <NUM>. If the rotation number/vehicle speed selecting switch <NUM> designates the traveling speed, the rotation number/vehicle speed setting dial <NUM> sets the maximum traveling speed of the traveling machine body <NUM>.

As shown in <FIG> and <FIG>, a switch box <NUM> is embedded in the base <NUM> of the arm rest <NUM> on the side of the back cockpit <NUM>. An upper surface of the switch box <NUM> includes an upper surface lid <NUM> which opens toward a direction opposite from the cockpit <NUM>. That is, the upper surface lid <NUM> is pivotally supported by a side edge which is on the opposite side from the cockpit <NUM> such that an axial direction of a rotation shaft of the upper surface lid <NUM> becomes equal to a longitudinal direction of the base <NUM>. Therefore, when the upper surface lid <NUM> opens, since the inner side of the switch box <NUM> is opened from the side of the cockpit <NUM>, an operator sitting on the cockpit <NUM> can easily operate. Normally, the upper surface lid <NUM> is closed, an upper surface of the upper surface lid <NUM> is located at the same height position as the upper surface of the base <NUM> of the arm rest <NUM>, and the operator puts the arm or elbow on the upper surface lid <NUM>.

The switch box <NUM> is arranged such that its longitudinal direction extends along a longitudinal direction of the base <NUM>. An inner upper surface of the switch box <NUM> which is opposed to a lower surface of the upper surface lid <NUM> includes the inclination setting dial <NUM>, the most-hoisted position setting dial <NUM> and the lowering speed setting dial <NUM>. That is, when the upper surface lid <NUM> opens, the setting dials <NUM> to <NUM> are arranged on a line on the inner upper surface of the switch box <NUM>. The inclination setting dial <NUM> is for presetting a target lateral inclination angle of the rotary cultivator <NUM> relative to the traveling machine body <NUM>. The most-hoisted position setting dial <NUM> is for setting a most-hoisted position of the rotary cultivator <NUM>. The lowering speed setting dial <NUM> is for setting speed when the rotary cultivator <NUM> is lowered for reducing the impact when the rotary cultivator <NUM> is lowered.

As shown in <FIG>, the main transmission lever <NUM> includes a lever shaft <NUM>, and a grip <NUM> (holding part) grasped by an operator is mounted on an upper end of the lever shaft <NUM>. A lower end of the lever shaft <NUM> is pivotally supported in the extending portion <NUM> which becomes a lower side of the front notch <NUM>. Thus, the main transmission lever <NUM> can incline forward and rearward. That is, the main transmission lever <NUM> can incline forward and rearward from a substantially vertical attitude to a forward attitude. As shown in <FIG> and <FIG>, a front end surface of the extending portion <NUM> except the front notch <NUM> is composed of a forward curved surface <NUM> which is a substantially <NUM>/<NUM> circular curved surface extending along a turning locus of the main transmission lever <NUM>. Therefore, the grip <NUM> projects from the forward curved surface <NUM> of the extending portion <NUM> irrespective of an inclination attitude of the main transmission lever <NUM>. With this configuration, since the operator's hand grasping the grip <NUM> does not touch the extending portion <NUM> of the arm rest <NUM>, the operator can smoothly operate the main transmission lever <NUM>.

When the main transmission lever <NUM> is inclined forward (toward steering handle <NUM>), the main transmission potentio <NUM> inclines the pump swash plate <NUM> (see <FIG>) toward a positive inclination angle side in accordance with an operation position of the main transmission lever <NUM>, and the main transmission potentio <NUM> accelerates the traveling speed of the traveling machine body <NUM>. When the main transmission lever <NUM> is inclined rearward (toward cockpit <NUM>) , the main transmission potentio <NUM> inclines the pump swash plate <NUM> (see <FIG>) toward a negative inclination angle side in accordance with the operation position of the main transmission lever <NUM>, and the main transmission potentio <NUM> decelerates the traveling speed of the traveling machine body <NUM>.

The operator can operate the main transmission lever <NUM> in a state where the arm is put on the upper surface lid <NUM> (on arm rest <NUM>). Therefore, it is extremely easy to operate the main transmission lever <NUM>, and it is possible to exert a high effect for enhancing the travelling operability in the tractor <NUM>. At this time, a position of the step portion <NUM> is a position on which the operator's wrist is not superposed almost at all as viewed from above in a state where the operator's arm is placed on the upper surface lid <NUM> (on arm rest <NUM>). Therefore, the arm on the arm rest <NUM> does not unintentionally touch (does not hinder) the setting dial <NUM> and the selecting switch <NUM>, and a wrong operation of the setting dial <NUM> and the selecting switch <NUM> can be reduced.

As shown in <FIG>, the grip <NUM> of the main transmission lever <NUM> includes a grip portion <NUM>, and an upper surface of the grip portion <NUM> is formed into a gently upward convex-curved surface. A portion of an upper surface of the grip portion <NUM> of the grip <NUM> on the side of the cockpit <NUM> is inclined such that the upper surface becomes an uppermost end so that the operator can easily grasp the grip portion <NUM> with a right hand. A lateral width of this grip portion <NUM> is narrowed toward a connection between the grip portion <NUM> and the lever shaft <NUM> (downward) as viewed from front. That is, the grip portion <NUM> is provided at its lower side with a narrow part. A lever connecting portion <NUM> which is to be connected to the lever shaft <NUM> is provided on a lower side of the grip portion <NUM> of the grip <NUM>. A lateral width of the lever connecting portion <NUM> is equal to a lateral width of the lower side of the grip portion <NUM>.

In the grip <NUM>, the automatic elevating switch <NUM> is arranged on a front surface of the lever connecting portion <NUM>, and the elevation finely adjusting switch <NUM> is arranged on a side surface (left side surface) of the lever connecting portion <NUM> on the side of the cockpit <NUM>. In the grip portion <NUM> of the grip <NUM>, the display change-over switch <NUM> is arranged on a narrow part surface on the side (left side) of the cockpit <NUM>, and the mode change-over switch <NUM> is arranged on the narrow part surface on the opposite side (right side) of the cockpit <NUM>. The automatic elevating switch <NUM> is for forcibly hoisting and lowering the rotary cultivator <NUM> to a predetermined height. The elevation finely adjusting switch <NUM> is for finely adjusting a height position of the rotary cultivator <NUM>. The display change-over switch <NUM> is for switching between the display contents of the liquid crystal panel <NUM>. The mode change-over switch <NUM> is for changing and adjusting the traveling speed when the tractor turns and travels rearward.

The automatic elevating switch <NUM> is a self-reset type (momentary type) lever switch which inclines in the vertical direction. When the automatic elevating switch <NUM> is inclined upward, the rotary cultivator <NUM> is hoisted to a most-hoisted position which is set by the most-hoisted position setting dial <NUM>, and when the automatic elevating switch <NUM> is inclined downward, the rotary cultivator <NUM> is lowered to a position which is set by the working unit position dial <NUM>. The elevation finely adjusting switch <NUM> is composed of a self-reset type (momentary type) rocker switch, and the rotary cultivator <NUM> is hoisted and lowered only while the elevation finely adjusting switch <NUM> is operated.

Since the main transmission lever <NUM> includes the automatic elevating switch <NUM>, the elevation finely adjusting switch <NUM>, the display change-over switch <NUM> and the mode change-over switch <NUM>, the operator can easily perform control in accordance with a traveling situation only by operating the main transmission lever <NUM> with the right hand. That is, it is possible to adjust a height position of the rotary cultivator <NUM> by operating the automatic elevating switch <NUM> and the elevation finely adjusting switch <NUM> while carrying out the inclining operation of the main transmission lever <NUM>. Even when the operator desires to switch between the display contents of the liquid crystal panel <NUM>, the operator only needs to operate the display change-over switch <NUM> without releasing the hand from the main transmission lever <NUM>. Further, when the tractor <NUM> is made to turn or travel rearward only by operating the mode change-over switch <NUM> of the main transmission lever <NUM>, it is possible to easily adjust the traveling speed to an optimally preset value.

As shown in <FIG> and <FIG>, the working unit position dial (elevating dial) <NUM> is fitted into a substantially circular dent (side surface notch) <NUM> in a right side surface (side surface on the side of fenders <NUM>) in the extending portion <NUM> of the arm rest <NUM>. The dent <NUM> has a circular recess 288a which is formed by recessing the right side surface of the extending portion <NUM>, and the working unit position dial <NUM> is turnably fitted into the circular recess 288a. The dent <NUM> has a recess 288b formed by recessing a portion of an upper side of the circular recess 288a up to an upper surface of the extending portion <NUM>, and front and rear step portions of the recess 288b become rotation-restricting portions 289a and 289b which restrict rotation of the working unit position dial <NUM>.

The working unit position dial <NUM> is fitted into the dent <NUM> such that the working unit position dial <NUM> is pivotally supported by a center of the circular recess 288a of the dent <NUM>, the working unit position dial <NUM> has a knob (operating projection) <NUM> formed on an outer peripheral surface <NUM> on the side of the upper surface of the extending portion <NUM>, and the knob <NUM> projects outward (upward). That is, the knob <NUM> is fitted into the recess 288b on the upper side of the dent <NUM>, and the operator can check the knob <NUM> of the working unit position dial <NUM> from an upper side of the arm rest <NUM>.

Even if the knob <NUM> is located at the highest position of the working unit position dial <NUM>, an upper end of the knob <NUM> is lower than the upper surface of the extending portion <NUM>. If the knob <NUM> abuts against the rotation-restricting portion 289a, forward (in clockwise direction in <FIG>) rotation of the working unit position dial <NUM> is restricted, and if the knob <NUM> abuts against the rotation-restricting portion 289b, rearward (in counterclockwise direction in <FIG>) rotation of the working unit position dial <NUM> is restricted. Therefore, when the main transmission lever <NUM> is operated, it is possible not only to prevent the operator from touching the working unit position dial <NUM> by mistake, but it is also possible to restrict the rotation region within a predetermined width when the working unit position dial <NUM> is operated.

When the working unit position dial <NUM> is fitted into the dent <NUM>, the working unit position dial <NUM> projects outward (toward fenders <NUM>) more than a right side surface of the extending portion <NUM>. Thus, the operator can rotate the working unit position dial <NUM> by moving the knob <NUM> forward and rearward with fingers from the upper side of the arm rest <NUM>, and even if the operator grasps the outer peripheral surface from the right side (from fenders <NUM>) of the arm rest <NUM>, it is possible to rotate the working unit position dial <NUM>. Therefore, the operator can easily operate the working unit position dial <NUM> in a state where the arm is placed on the upper surface lid <NUM> (on arm rest <NUM>).

If the working unit position dial <NUM> is rotated forward (clockwise direction in <FIG>), the control solenoid valve <NUM> carries out the switching operation, a single acting type hydraulic cylinder (not shown) is shortened and driven, and a lift arm <NUM> (see <FIG>) is turned downward. As a result, the rotary cultivator <NUM> is lowered through the lower links <NUM>. If the working unit position dial <NUM> is inclined rearward (counterclockwise direction in <FIG>), the control solenoid valve <NUM> carries out the switching operation, and the single acting type hydraulic cylinder (not shown) is extended and driven, and the lift arm <NUM> is turned upward. As a result, the rotary cultivator <NUM> is hoisted through the lower links <NUM>.

In this embodiment, the main transmission lever <NUM>, the setting dial <NUM> and the selecting switch <NUM> are arranged on the upper surface of the extending portion <NUM> which is a front portion of the arm rest <NUM>, and the working unit position dial <NUM> is arranged on the side surface of the extending portion <NUM>. The main transmission lever <NUM>, the setting dial <NUM> and the selecting switch <NUM> are arranged on the left side (on the side of cockpit <NUM>) of the extending portion <NUM>, and the working unit position dial <NUM> is arranged on the right side (on the side of fenders <NUM>) of the extending portion <NUM>. Therefore, even during driving of the tractor <NUM>, the operator can easily discriminate between the traveling system operating means and the working system operating means, and this is effective for preventing a wrong operation. Further, since the main transmission lever <NUM>, the setting dial <NUM> and the selecting switch <NUM> which are the traveling system operating means are collectively arranged, the operability (handling performance) is excellent.

If the hand on the arm rest <NUM> is moved in the lateral direction around the elbow as a fulcrum, the hand easily reaches the main transmission lever <NUM> and the working unit position dial <NUM>. Therefore, there is an advantage that it is possible to operate the main transmission lever <NUM> and the working unit position dial <NUM> only by a hand on the arm rest <NUM>. When the arm is placed on the arm rest <NUM>, it is possible to operate the main transmission lever <NUM> and the working unit position dial <NUM> on the extending portion <NUM> with a natural hand attitude in which a wrist does not bend downward. Hence, operability of the main transmission lever <NUM> and the working unit position dial <NUM> is remarkably enhanced, and the hand is stably supported.

A detailed structure of an arm rest <NUM> according to a second embodiment will be described with reference to <FIG>. The arm rest <NUM> of the second embodiment includes a base (arm rest rear portion) <NUM> which extends long in a longitudinal direction of the arm rest <NUM>, and an extending portion (arm rest front portion) <NUM> which extends forward from the base <NUM>. The extending portion <NUM> is arranged such that it bends in a direction (right direction in this embodiment) separating away from a cockpit <NUM> with respect to the base <NUM> which extends in parallel to the cockpit <NUM>, and the arm rest <NUM> is formed into a substantially L-shape as a whole as viewed from above.

As shown in <FIG> and <FIG>, the arm rest <NUM> includes a front notch <NUM> in a front end of the extending portion <NUM> on the side of the cockpit <NUM>. The front notch <NUM> is recessed downward from an upper surface of the arm rest <NUM>. The main transmission lever <NUM> projects from an upper surface of the front notch <NUM>. As shown in <FIG> and <FIG>, a later-described rotation number/vehicle speed setting dial (setting dial) <NUM> is turnably pivotally supported on a front side (on the side of steering handle <NUM>) on a right side surface of the extending portion <NUM> (side surface on the side of fenders <NUM>). A later-described rotation number/vehicle speed selecting switch (selecting switch) <NUM> is arranged at a position on an upper surface of the extending portion <NUM> between the main transmission lever <NUM> and the rotation number/vehicle speed setting dial <NUM> (right side position of front notch <NUM>).

With this configuration, even if an operator puts his or her arm or elbow on the base <NUM> of the arm rest <NUM> and operates the main transmission lever <NUM> or the working unit position dial <NUM> in front of the extending portion <NUM>, it is possible to reduce fear that the operator unintentionally touches the setting dial <NUM> and the selecting switch <NUM> arranged closer to the fenders <NUM> than the main transmission lever <NUM>. Therefore, it is possible to remarkably reduce or prevent a wrong operation of the setting dial <NUM> and the selecting switch <NUM>.

The rotation number/vehicle speed setting dial <NUM> is for presetting maximum rotation speed of the engine <NUM> or maximum travelling speed of the traveling machine body <NUM>. The rotation number/vehicle speed selecting switch <NUM> is for designating whether a value which is set by the rotation number/vehicle speed setting dial <NUM> is the maximum rotation speed of the engine <NUM> or the maximum traveling speed of the traveling machine body <NUM>. The rotation number/vehicle speed selecting switch <NUM> is composed of a position-keeping type (alternate type) switch (position-keeping type rocker switch in example of this embodiment). With this configuration, if the rotation number/vehicle speed selecting switch <NUM> designates the rotation speed, the rotation number/vehicle speed setting dial <NUM> sets the maximum rotation speed of the engine <NUM>. If the rotation number/vehicle speed selecting switch <NUM> designates the traveling speed, the rotation number/vehicle speed setting dial <NUM> sets the maximum traveling speed of the traveling machine body <NUM>.

As shown in <FIG> and <FIG>, a switch box <NUM> is embedded in the base <NUM> of the arm rest <NUM> on the side of the back cockpit <NUM>. An upper surface of the switch box <NUM> includes an upper surface lid <NUM> which opens toward a direction opposite from the cockpit <NUM>. That is, the upper surface lid <NUM> is pivotally supported by a side edge which is on the opposite side from the cockpit <NUM> such that an axial direction of a rotation shaft of the upper surface lid <NUM> becomes equal to a longitudinal direction of the base <NUM>. Therefore, when the upper surface lid <NUM> opens, since the inner side of the switch box <NUM> is opened from the side of the cockpit <NUM>, the operator sitting on the cockpit <NUM> can easily operate. Normally, the upper surface lid <NUM> is closed, an upper surface of the upper surface lid <NUM> is located at the same height position as the upper surface of the base <NUM> of the arm rest <NUM>, and the operator puts the arm or elbow on the upper surface lid <NUM>.

The switch box <NUM> is arranged such that its longitudinal direction extends along a longitudinal direction of the base <NUM>. An inner upper surface of the switch box <NUM> which is opposed to a lower surface of the upper surface lid <NUM> includes an inclination setting dial <NUM>, a most-hoisted position setting dial <NUM> and a lowering speed setting dial <NUM>. That is, when the upper surface lid <NUM> opens, the setting dials <NUM> to <NUM> are arranged on a line on the inner upper surface of the switch box <NUM>. The inclination setting dial <NUM> is for presetting a target lateral inclination angle of the rotary cultivator <NUM> relative to the traveling machine body <NUM>. The most-hoisted position setting dial <NUM> is for setting a most-hoisted position of the rotary cultivator <NUM>. The lowering speed setting dial <NUM> is for setting speed when the rotary cultivator <NUM> is lowered for reducing the impact when the rotary cultivator <NUM> is lowered.

As shown in <FIG>, the main transmission lever <NUM> includes a lever shaft <NUM>, and a grip <NUM> grasped by the operator is mounted on an upper end of the lever shaft <NUM>. A lower end of the lever shaft <NUM> is pivotally supported in the extending portion <NUM> which becomes a lower side of the front notch <NUM>. Thus, the main transmission lever <NUM> can incline forward and rearward. That is, the main transmission lever <NUM> can incline forward and rearward from a substantially vertical attitude to a forward attitude. As shown in <FIG> and <FIG>, a front end surface of the extending portion <NUM> except the front notch <NUM> is composed of a forward curved surface <NUM> which is a substantially <NUM>/<NUM> circular curved surface extending along a turning locus of the main transmission lever <NUM>. Therefore, the grip <NUM> projects from the forward curved surface <NUM> of the extending portion <NUM> irrespective of an inclination attitude of the main transmission lever <NUM>. With this configuration, since the operator's hand grasping the grip <NUM> does not touch the extending portion <NUM> of the arm rest <NUM>, the operator can smoothly operate the main transmission lever <NUM>.

When the main transmission lever <NUM> is inclined forward (toward steering handle <NUM>), the main transmission potentio <NUM> inclines the pump swash plate <NUM> (see <FIG>) toward a positive inclination angle side in accordance with an operation position of the main transmission lever <NUM>, and the main transmission potentio <NUM> accelerates the traveling speed of the traveling machine body <NUM>. When the main transmission lever <NUM> is inclined rearward (toward cockpit <NUM>), the main transmission potentio <NUM> inclines the pump swash plate <NUM> (see <FIG>) toward a negative inclination angle side in accordance with the operation position of the main transmission lever <NUM>, and the main transmission potentio <NUM> decelerates the traveling speed of the traveling machine body <NUM>.

As shown in <FIG>, the grip <NUM> of the main transmission lever <NUM> includes a grip portion <NUM>, and an upper surface of the grip portion <NUM> is formed into a gently upward convex-curved surface. A portion of an upper surface of the grip portion <NUM> of the grip <NUM> on the side of the cockpit <NUM> is inclined such that the upper surface becomes an uppermost end so that the operator can easily grasp the grip portion <NUM> with a right hand. A lateral width of this grip portion <NUM> is narrowed toward (downward) a connection between the grip portion <NUM> and the lever shaft <NUM> as viewed from front. That is, the grip portion <NUM> is provided at its lower side with a narrow part. A lever connecting portion <NUM> which is to be connected to the lever shaft <NUM> is provided on the lower side of the grip portion <NUM> of the grip <NUM>. A lateral width of the lever connecting portion <NUM> is equal to a lateral width of the lower side of the grip portion <NUM>.

As shown in <FIG> and <FIG>, the working unit position dial (elevating dial) <NUM> is fitted into a substantially circular dent (side surface notch) <NUM> behind the rotation number/vehicle speed setting dial (setting dial) <NUM> in a right side surface (side surface on the side of fenders <NUM>) in the extending portion <NUM> of the arm rest <NUM>. That is, the rotation number/vehicle speed setting dial <NUM> is arranged in front of the working unit position dial <NUM> in a right side surface of the arm rest <NUM>. The rotation number/vehicle speed selecting switch <NUM> is arranged on the upper surface of the arm rest <NUM> at a position between the main transmission lever <NUM> and the rotation number/vehicle speed setting dial <NUM>.

The dent <NUM> has a circular recess 288a which is formed by recessing the right side surface of the extending portion <NUM>, and the working unit position dial <NUM> is turnably fitted into the circular recess 288a. The dent <NUM> has a recess 288b formed by recessing a portion of an upper side of the circular recess 288a up to an upper surface of the extending portion <NUM>, and front and rear step portions of the recess 288b become rotation-restricting portions 289a and 289b which restrict rotation of the working unit position dial <NUM>.

The working unit position dial <NUM> is fitted into the dent <NUM> such that the working unit position dial <NUM> is pivotally supported by a center of the circular recess 288a of the dent <NUM>, the working unit position dial <NUM> has a knob (operating projection) <NUM> provided on the outer peripheral surface <NUM> on the side of the upper surface of the extending portion <NUM>, and the knob <NUM> projects outward (upward). That is, the knob <NUM> is fitted into the recess 288b on the upper side of the dent <NUM>, and the operator can check the knob <NUM> of the working unit position dial <NUM> from an upper side of the arm rest <NUM>.

Even if the knob <NUM> is located at the highest position of the working unit position dial <NUM>, an upper end of the knob <NUM> is lower than the upper surface of the extending portion <NUM>. If the knob <NUM> abuts against the rotation-restricting portion 289a, forward (in clockwise direction in <FIG>) rotation of the working unit position dial <NUM> is restricted, and if the knob <NUM> abuts against the rotation-restricting portion 289b, rearward (in counterclockwise direction in <FIG>) rotation of the working unit position dial <NUM> is restricted. Therefore, when the main transmission lever <NUM> is operated, it is possible not only to prevent the operator from unintentionally touching the working unit position dial <NUM>, but it is also possible to restrict the rotation region within a predetermined width when the working unit position dial <NUM> is operated.

When the working unit position dial <NUM> is fitted into the dent <NUM>, the working unit position dial <NUM> projects outward (toward fenders <NUM>) more than a right side surface of the extending portion <NUM>. Thus, the operator can rotate the working unit position dial <NUM> by moving the knob <NUM> back and forth with fingers from the upper side of the arm rest <NUM>, and even if the operator grasps the outer peripheral surface from the right side (fenders <NUM> side) of the arm rest <NUM>, it is possible to rotate the working unit position dial <NUM>. Therefore, the operator can easily operate the working unit position dial <NUM> in a state where the arm is placed on the upper surface lid <NUM> (on arm rest <NUM>).

In this embodiment, the main transmission lever <NUM>, the setting dial <NUM> and the selecting switch <NUM> are arranged from the upper surface to the side surface of a front end of the extending portion <NUM> which is a front portion of the arm rest <NUM>, and the working unit position dial <NUM> is arranged behind the side surface of the extending portion <NUM>. Therefore, even during driving of the tractor <NUM>, the operator can easily discriminate between the traveling system operating means and the working system operating means, and this is effective for preventing a wrong operation. Further, since the main transmission lever <NUM>, the setting dial <NUM> and the selecting switch <NUM> which are the traveling system operating means are collectively arranged, the operability (handling performance) is excellent.

If the hand on the arm rest <NUM> is moved in the lateral direction around the elbow as a fulcrum, the hand easily reaches the main transmission lever <NUM> and the working unit position dial <NUM>. Therefore, there is a merit that it is possible to operate the main transmission lever <NUM> and the working unit position dial <NUM> only with a hand on the arm rest <NUM>. When the arm is placed on the arm rest <NUM>, it is possible to operate the main transmission lever <NUM> and the working unit position dial <NUM> on the extending portion <NUM> with a natural hand attitude in which a wrist does not bend downward. Hence, operability of the main transmission lever <NUM> and the working unit position dial <NUM> is remarkably enhanced, and the hand is stably supported.

The invention of the present application is not limited to the above-described first to third embodiments, and the invention can be embodied in various modifications. For example, the invention of the present application is not limited to the tractor, and the invention can be applied also to an agricultural working machine such as a rice transplanter and a combined harvester, and a special working vehicle such as a wheel loader. The engine <NUM> provided in the traveling machine body <NUM> is not limited to a diesel engine, and the engine may be a gasoline engine.

The arm rest <NUM> need not be provided on the right side of the cockpit <NUM>, and may be provided on the left side of the cockpit <NUM>. When the arm rest <NUM> provided with the various kinds of operating means is provided on one of the right and left sides of the cockpit <NUM>, an arm rest having no operating means may be provided on the other side of the cockpit <NUM>. Further, as described in Fig. <NUM>, the front end surface of the extending portion <NUM> of the arm rest <NUM> may not be provided with the front notch <NUM> of the above-described embodiments, and the entire front end surface may be composed of the forward curved surface <NUM> which is a substantially <NUM>/<NUM> circular curved surface.

Claim 1:
A working vehicle (<NUM>) such as a tractor and a civil engineering wheel loader, comprising:
a travelling machine body (<NUM>) comprising an engine frame (<NUM>) having a front bumper (<NUM>) and a front axle case (<NUM>), and right and left machine body frames (<NUM>) detachably fixed to a rear portion of the engine frame (<NUM>) with bolts wherein an engine (<NUM>) is provided in the travelling machine body (<NUM>);
a travelling unit and a working unit;
a hydraulic continuously variable transmission, wherein speed of rotation power from the engine is changed and transmitted to the travelling unit and the working unit;
a cockpit (<NUM>) in the travelling machine body (<NUM>); and
an armrest (<NUM>) placed lateral to the cockpit (<NUM>) in the travelling machine body (<NUM>), wherein
a main transmission lever (<NUM>) for changing traveling speed by the traveling unit is arranged on a front end of the arm rest (<NUM>), and an elevating dial (<NUM>) for hoisting and lowering the working unit is arranged on a side surface of the arm rest (<NUM>) on a side of the armrest (<NUM>) not facing the cockpit (<NUM>), characterized in that
the elevating dial (<NUM>) is fitted to a side surface of the arm rest (<NUM>) such that an upper end of the elevating dial (<NUM>) is located lower than an upper surface of the arm rest (<NUM>),
a side notch for operating a dial is provided in the side surface of the arm rest (<NUM>) above an installation region of the elevating dial (<NUM>), an operating projection is provided above the elevating dial (<NUM>), and
front and rear step portions (<NUM>) of the side notch are brought into abutment against the operating projection, thereby configuring the step portions as a rotation-restricting portion which restricts rotation of the elevating dial (<NUM>).