Patent Description:
For example, a tractor disclosed in Patent Literature <NUM> being an example of a work vehicle employing an autonomous traveling system includes a Global Positioning System (GPS) antenna (GNSS antenna) for acquiring satellite positioning information from a positioning satellite on an upper surface of a cabin roof of the work vehicle.

Specifically, on the upper surface of the cabin roof, a mounting stay having a substantially horizontal mounting seat at a higher position than the top surface of the cabin roof is formed in a portion including an intersection of a front-rear direction line at the approximate center position of the tread width of the vehicle body and a transverse direction line at the approximate center position of the wheel base, and the GPS antenna is mounted on the mounting seat of the mounting stay.

Further, if a GPS antenna with a gyro sensor is used for the GPS antenna, the inclination angle of the cabin roof can be also detected. Document <CIT> relates to an unmanned work system using an unmanned work vehicle.

The above-described conventional technique discloses a technique for improving the detection accuracy of the GPS antenna or the detection accuracy of both the GPS antenna and the gyro sensor by elaborating the mounting position of the GPS antenna on the upper surface of the cabin roof.

However, the above-described autonomous traveling system is provided with various types of external devices separately from the work vehicle, such as a wireless communication terminal that issues various types of instructions to the work vehicle and a base station that acquires position information of the work vehicle.

Therefore, when the work vehicle actually autonomously travels, it is necessary to efficiently mount, on the work vehicle, not only the GPS antenna but also various types of antenna devices for communicating between the work vehicle and external devices. In this respect, the above-described conventional technique has room for improvement.

In addition, in the above-described conventional technique, the upper surface of the cabin roof provided at the upper part of the cabin frame has many curves and is also less rigid than the cabin frame. Accordingly, it is necessary to reinforce the mounting stay on which the GPS antenna is mounted without impairing the appearance of the cabin roof. Also in this respect, the conventional technique has room for improvement.

In view of this situation, a main object of the present invention is to provide a work vehicle capable of efficiently mounting various types of antenna devices effective for autonomous traveling, and the like, of the work vehicle and securely supporting the various types of antenna devices.

A first characteristic configuration according to the present invention is that, in a work vehicle with a cabin, a support frame extending in a lateral width direction is fixed to a cabin frame at an upper position outside the cabin, an antenna unit in which an inertial measurement unit, a GNSS antenna, and a wireless communicator are built is attached to the support frame in a state where the inertial measurement unit and the GNSS antenna are placed at a substantially center position in a lateral width direction of a vehicle body, and the antenna unit is attached to the support frame to be displaceable from a normal use position in which the antenna unit protrudes above a roof of the cabin, to a lower non-use position in which the antenna unit is lower than the highest part of the roof.

With the above configuration, the inertial measurement unit and the GNSS antenna which are built in the antenna unit are placed at the substantially center position in the left-right width direction of the vehicle body, and thus, it is possible to improve both the detection accuracy of the current position information of the work vehicle acquired from a reception signal of the GNSS antenna and the detection accuracy of the posture change information of the vehicle body acquired from the inertial measurement unit.

Further, the wireless communicator built in the antenna unit enables a wireless communication of various types of signals, with an external device such as a wireless communication terminal.

In addition, the support frame on which the antenna unit is mounted is fixed to the rigid cabin frame in a posture along the lateral width direction at the upper position and outside of the cabin, and thus, the support frame can be configured as a strong support structure. Further, the cabin frame has a height close to that of the cabin roof, and thus, if a mounting position of the support frame is set to an upper side of the cabin frame, it is possible to easily place the antenna unit at a height position where each of the inertial measurement unit, the GNSS antenna, and the wireless communicator function properly.

Therefore, the adoption of the antenna unit in which the inertial measurement unit, the GNSS antenna, and the wireless communicator are built, the installation position of the inertial measurement unit and the GNSS antenna with respect to the vehicle body, and the above-described rational elaboration in the support structure of the antenna unit make it possible to improve both the detection accuracy of the inertial measurement unit and the detection accuracy of the GNSS antenna and make it possible to efficiently install the inertial measurement unit and the GNSS antenna in the work vehicle while a satisfactory communication of the wireless communicator is maintained. In addition, it is possible to configure a strong support structure of the installed antenna unit.

In a second characteristic configuration according to the present invention, the support frame is bridged to be coupled to mirror mounting parts provided on the left and right of the cabin frame.

According to the above configuration, the left and right mirror mounting parts are arranged to protrude from the rigid cabin frame, and are placed at a height position close to that of the cabin roof. Therefore, it is possible to firmly and easily mount the support frame of the antenna unit at an appropriate height position by utilizing the two mirror mounting parts that are sturdy and have adequate height above the ground.

According to the present invention, the antenna unit is attached to the support frame to be displaceable from a normal use position to a lower non-use position.

According to the invention, if the antenna unit is in the normal use position, for example, the antenna unit or an antenna mounted on the antenna unit is placed to protrude above the upper surface of the cabin roof. Therefore, the height of a transport vehicle such as a truck to transport the work vehicle is high, and thus, there may be a problem that the vehicle is subject to height restrictions in traveling on a road or the like. Therefore, in the present invention, if the antenna unit is displaced from the normal use position to the lower non-use position with respect to the support frame, it is possible to easily cope with problems such as the height restrictions in traveling on a road.

In the third characteristic configuration according to the present invention, the work vehicle includes a control unit configured to perform autonomous traveling control of the vehicle body based on information acquired by the inertial measurement unit and the GNSS antenna, and an autonomous traveling restraint unit configured to restrict start of the autonomous traveling control by the control unit unless it is detected that the antenna unit is in the normal use position.

According to the above configuration, if it is detected that the antenna unit is in the normal use position, the autonomous traveling restraint unit is not activated, and the control unit starts autonomous traveling control based on information acquired by the inertial measurement unit and the GNSS antenna. If it is not detected that the antenna unit is in the normal use position, the restriction is activated by the autonomous traveling restraint unit and the start of the autonomous traveling control is restricted by the control unit. As a result, it is possible to accurately and safely perform autonomous traveling of the vehicle body along a target traveling route based on the accurate information acquired by the inertial measurement unit and the GNSS antenna while employing the position displacement structure of the antenna unit in accordance with height restrictions and the like in traveling on a road.

In a fourth characteristic configuration according to the present invention, a control unit configured to perform autonomous traveling control of the vehicle body based on information acquired by the inertial measurement unit and the GNSS antenna is provided in the cabin, and a harness led out from the antenna unit is arranged to reach the control unit in the cabin via an internal/external communication passage provided in the cabin frame.

According to the above configuration, the antenna unit placed at the upper position outside the cabin and the control unit provided in the cabin can be connected by a rational arrangement of the harness passing through the internal/external communication passage provided in the cabin frame.

In a fifth characteristic configuration according to the present invention, the harness led out from the antenna unit is arranged at one side edge in a lateral width direction on the outer surface of a windshield of the cabin, and along a band-shaped part overlapping with a glass receiving part of a front pillar of the cabin.

According to the above configuration, one side edge in the lateral width direction on the outer surface of the windshield and the band-shaped part overlapping the glass receiving part of the front pillar form a glass attaching part for attaching the windshield to the front part of the cabin, and are also in a position that does not interfere with viewing. Therefore, the harness led out from the antenna unit is placed in the above-described band-shaped part, and thus, it is possible to place the harness in a good appearance while maintaining good conditions for a visual field of an operator seated on the driver's seat.

Embodiments of the present invention will be described with reference to the drawings.

An autonomous traveling system illustrated in <FIG> and <FIG> is configured to generate a target traveling route and enable a tractor <NUM> serving as a work vehicle to autonomously travel along the generated target traveling route. The autonomous traveling system includes, in addition to the tractor <NUM> capable of autonomous traveling, a wireless communication terminal <NUM> configured to issue various types of instructions to the tractor <NUM>, and a reference station <NUM> configured to acquire position information of the tractor <NUM>.

First, the tractor <NUM> will be described with reference to <FIG>.

The tractor <NUM> includes a vehicle body <NUM> configured to mount a ground work machine (not illustrated) on the rear side, a front part of the vehicle body <NUM> is supported by a pair of left and right front wheels <NUM>, and a rear part of the vehicle body <NUM> is supported by a pair of left and right rear wheels <NUM>. A hood <NUM> is placed in the front part of the vehicle body <NUM>, and an engine <NUM> serving as a drive source is housed inside the hood <NUM>. A cabin <NUM> in which a driver rides is provided behind the hood <NUM>, and a steering handle <NUM> with which the driver performs a steering operation, a driver's seat <NUM> for the driver, and the like are provided in the cabin <NUM>.

The engine <NUM> can include, for example, a diesel engine, but is not limited to this, and may include, for example, a gasoline engine. Further, an electric motor may be employed as a drive source in addition to or instead of the engine <NUM>.

Further, in the present embodiment, the tractor <NUM> will be described as a work vehicle by way of example, but examples of the work vehicle include, in addition to a tractor, riding type of work vehicles such as a rice transplanter, a combine, a civil engineering/construction work device, and a snowplow.

A three-point link mechanism including a pair of left and right lower links <NUM> and an upper link <NUM> is provided on the rear side of the vehicle body <NUM> so that a ground work machine is mountable on the three-point link mechanism. Although not illustrated, a lifting device including a hydraulic device such as a lifting cylinder is provided on the rear side of the vehicle body <NUM>, and the lifting device raises and lowers the three-point link mechanism to raise and lower the ground work machine.

Examples of the ground work machine include a tilling device, a plow, and a fertilizing device.

As illustrated in <FIG>, the tractor <NUM> includes a governor device <NUM> configured to adjust the rotation speed of the engine <NUM>, a transmission device <NUM> configured to change a rotational driving force from the engine <NUM> and transmit the rotational driving force to driving wheels, a control unit <NUM> configured to control the governor device <NUM> and the transmission device <NUM>, and the like. The transmission device <NUM> is configured of, for example, a combination of a main transmission device including a hydraulic continuously variable transmission device and an auxiliary transmission device including a gear-type multi-stage transmission device.

The tractor <NUM> is configured not only to travel with a driver riding in the cabin <NUM>, but also to autonomously travel based on, for example, an instruction from the wireless communication terminal <NUM> even without a driver riding in the cabin <NUM>.

As illustrated in <FIG>, the tractor <NUM> includes a steering device <NUM>, an inertial measurement unit (IMU) <NUM> configured to obtain posture change information of the vehicle body, a GNSS antenna <NUM> configured to receive a wireless signal transmitted from a positioning satellite (navigation satellite) <NUM> included in a Global Navigation Satellite System (GNSS), a wireless communication unit (an example of a wireless communicator built in an antenna unit <NUM>) <NUM> configured to transmit and receive various types of signals via a wireless communication network established between the wireless communication unit <NUM> and the wireless communication terminal <NUM> or the like, a base station antenna (an example of a wireless communicator built in the antenna unit <NUM>) <NUM> configured to receive a wireless signal (for example, a wireless signal with a frequency band of <NUM>) from a reference station wireless communicator <NUM> of the reference station <NUM>, and the like. As a result, the tractor <NUM> is configured to autonomously travel while acquiring its own current position information (position information of the vehicle body <NUM>).

The inertial measurement unit <NUM>, the GNSS antenna <NUM>, the wireless communication unit <NUM>, and the base station antenna <NUM> are housed in the antenna unit <NUM> including a unit cover <NUM> as illustrated in <FIG>. As illustrated in <FIG>, the antenna unit <NUM> is mounted on a support frame <NUM>, which is fixed to a cabin frame <NUM> of the cabin <NUM> and arranged along the lateral width direction, at an upper position on the front side outside the cabin <NUM>.

It is noted that a specific internal arrangement structure and mounting structure of the antenna unit <NUM> will be described in detail after the description of the autonomous traveling system.

The steering device <NUM> is provided, for example, in the middle of the rotation shaft of the steering handle <NUM> and is configured to adjust the rotation angle (steering angle) of the steering handle <NUM>. The control unit <NUM> controls the steering device <NUM> to adjust the rotation angle of the steering handle <NUM> to a desired rotation angle so that the tractor <NUM> not only travels straight but also turns with a desired turning radius.

The inertial measurement unit <NUM> obtains a three-dimensional angular velocity and acceleration with a three-axial gyro and a three-directional accelerometer. A detection value of the inertial measurement unit <NUM> is input to the control unit <NUM>, and the control unit <NUM> operates the value by using a posture and azimuth operation means to obtain posture information (an azimuth angle (yaw angle) of the vehicle body, a tilt angle in the lateral direction (roll angle) of the vehicle body, and a tilt angle in the front-rear moving direction (pitch angle) of the vehicle body) of the tractor <NUM>.

In the Global Navigation Satellite System (GNSS), a satellite positioning system such as a quasi-zenith satellite (Japan) or a GLONASS satellite (Russia) in addition to the Global Positioning System (GPS), (USA), may also be employed for the positioning satellite.

In the present embodiment, the wireless communication unit <NUM> includes a Wi-Fi unit with a frequency band of <NUM>, but the wireless communication unit <NUM> may include Bluetooth (registered trademark) or the like instead of Wi-Fi. As illustrated in <FIG>, a signal received by a wireless communication antenna <NUM> of the wireless communication unit <NUM> may be input to the control unit <NUM>, and the signal from the control unit <NUM> is configured to be transmitted by the wireless communication antenna <NUM> to a wireless communicator <NUM> of the wireless communication terminal <NUM> or the like.

Here, for a positioning method using the satellite positioning system, a positioning method is applicable, in which the reference station <NUM> installed at a predetermined reference point is provided, and satellite positioning information of the tractor <NUM> (mobile station) is corrected by correction information from the reference station <NUM> to obtain a current position of the tractor <NUM>. For example, various types of positioning methods such as a differential GPS positioning (DGPS) and a real-time kinematic positioning (RTK positioning) are applicable.

In the present embodiment, for example, the RTK positioning is applied. As illustrated in <FIG> and <FIG>, the GNSS antenna <NUM> is provided in the tractor <NUM>, being the mobile station, and additionally the reference station <NUM> including a reference station positioning antenna <NUM> is provided. The reference station <NUM> is placed at a position (reference point) where the traveling of the tractor <NUM> is not hindered, such as an area around a farm field. Position information of the reference point, being an installation position of the reference station <NUM>, is obtained in advance. The reference station <NUM> includes the reference station wireless communicator <NUM> configured to transmit and receive various types of signals to and from the base station antenna <NUM> of the tractor <NUM>. As a result, the reference station <NUM> is configured to transmit and receive a variety of information between the reference station <NUM> and the tractor <NUM> and between the reference station <NUM> and the wireless communication terminal <NUM>.

In the RTK positioning, both the reference station positioning antenna <NUM> of the reference station <NUM> installed at the reference point and the GNSS antenna <NUM> of the tractor <NUM>, being the mobile station side whose position information is to be obtained, measure a carrier phase (satellite positioning information) from the positioning satellite <NUM>. The reference station <NUM> generates correction information including the measured satellite positioning information and the position information of the reference point each time the satellite positioning information is measured from the positioning satellite <NUM> or each time a set period elapses, and transmits the correction information from the reference station wireless communicator <NUM> to the base station antenna <NUM> of the tractor <NUM>. The control unit <NUM> of the tractor <NUM> corrects the satellite positioning information measured by the GNSS antenna <NUM> by using the correction information transmitted from the reference station <NUM> to obtain the current position information of the tractor <NUM>. The control unit <NUM> obtains, for example, latitude information and longitude information as the current position information of the tractor <NUM>.

The autonomous traveling system includes, in addition to the tractor <NUM> and the reference station <NUM>, the wireless communication terminal <NUM> configured to issue an instruction to cause the tractor <NUM> to autonomously travel, to the control unit <NUM> of the tractor <NUM>. The wireless communication terminal <NUM> includes, for example, a tablet-type personal computer having a touch panel, and is configured to display a variety of information on the touch panel, and also to receive an input of a variety of information through an operation on the touch panel. The wireless communication terminal <NUM> includes the wireless communicator <NUM> and a route generation unit <NUM> configured to generate a target traveling route. The route generation unit <NUM> generates a target traveling route where the tractor <NUM> autonomously travels based on a variety of information input through the touch panel.

The control unit <NUM> included in the tractor <NUM> is configured to transmit and receive a variety of information to and from the wireless communication terminal <NUM> via a wireless communication network established with the wireless communicator <NUM> or the like. The wireless communication terminal <NUM> is configured to issue an instruction for autonomous traveling to the tractor <NUM> by transmitting a variety of information for causing the tractor <NUM> to autonomously travel, such as the target traveling route, to the control unit <NUM> of the tractor <NUM>. The control unit <NUM> of the tractor <NUM> is configured to obtain the current position information of the tractor <NUM> acquired from a reception signal of the GNSS antenna <NUM> so that the tractor <NUM> autonomously travels along the target traveling route generated by the route generation unit <NUM>, to obtain displacement information and azimuth information of the vehicle body from the inertial measurement unit <NUM>, and to control the transmission device <NUM>, the steering device <NUM>, and the like based on the current position information, the displacement information, and the azimuth information.

Next, an internal arrangement structure of the antenna unit <NUM> will be described.

As illustrated in <FIG>, the unit cover <NUM> of the antenna unit <NUM> includes a lower cover body <NUM> which is made of resin and has a substantially rectangular shape in a plan view, the upper side of which is opened, and an upper cover body <NUM> which is made of resin and has a substantially rectangular shape in a plan view, the lower side of which is opened. Here, <FIG> illustrates a longitudinal sectional view of the antenna unit <NUM> when viewed from the rear side, and the lateral direction in the vehicle body <NUM> is opposite to that of <FIG>, <FIG>, and <FIG>. An opening joint part of the upper cover body <NUM> externally fits onto and detachably joins to an opening joint part of the lower cover body <NUM> in a watertight manner. The opening joint part of the upper cover body <NUM> and the opening joint part of the lower cover body <NUM> are fixedly coupled by screws <NUM> in a plurality of places in the lateral direction on the front side and the rear side.

As illustrated in <FIG>, a base plate <NUM> made of metal, which is an example of a unit base configured to be mounted on the tractor <NUM>, is mounted on a bottom plate part 52A of the lower cover body <NUM>. As illustrated in <FIG>, a plurality of (four in the present embodiment) cylindrical first bosses <NUM> for maintaining an interval between the base plate <NUM> and the bottom plate part 52A of the lower cover body <NUM> at a set interval are arranged between the base plate <NUM> and the bottom plate part 52A of the lower cover body <NUM>, and a first bolt <NUM> is inserted into each of the first bosses <NUM> to fixedly couple the base plate <NUM> and the bottom plate part 52A of the lower cover body <NUM>.

As illustrated in <FIG>, at the center in the longitudinal direction of the base plate <NUM>, the inertial measurement unit <NUM> and the GNSS antenna <NUM>, which are placed at the center position or substantially the center position in the lateral width direction of the vehicle body, are provided in a state where the inertial measurement unit <NUM> and the GNSS antenna <NUM> overlap with each other vertically. Between these, the GNSS antenna <NUM> is the one placed above the inertial measurement unit <NUM>.

Specifically, a housing 25A of the inertial measurement unit <NUM> is fixedly coupled to the base plate <NUM> by second bolts <NUM> in a state where the center position in the lateral direction of the housing 25A is located at the center position in the longitudinal direction of the base plate <NUM>.

On the other hand, as illustrated in <FIG>, a housing 26A of the GNSS antenna <NUM> is mounted on the base plate <NUM> via a metal hat-shaped bracket <NUM> in a state where the center position in the lateral direction of the housing 26A is located at the center position in the longitudinal direction of the base plate <NUM>. The bracket <NUM> is formed in a hat shape detouring above the housing 25A of the inertial measurement unit <NUM> along the longitudinal direction of the base plate <NUM>. Both leg parts 60a of the hat-shaped bracket <NUM> are fixedly coupled to the base plate <NUM> by third bolts <NUM>, the width of the hat-shaped bracket <NUM> in the front-rear direction (also the front-rear direction of the vehicle body) is set to be slightly smaller than the width of the housing 25A of the inertial measurement unit <NUM> in the front-rear direction, and a part of the bracket <NUM> is configured as a shielding wall that provides shielding between the bracket <NUM> and the wireless communication unit <NUM> described later.

With the arrangement of the inertial measurement unit <NUM> and the GNSS antenna <NUM> described above, the inertial measurement unit <NUM> and the GNSS antenna <NUM> are placed vertically at the center position or substantially the center position in the lateral width direction of the vehicle body in a mounting state on the tractor <NUM> as illustrated in <FIG>. Accordingly, it is possible to improve both the detection accuracy of the current position information of the tractor <NUM> acquired from the reception signal of the GNSS antenna <NUM> and the detection accuracy of the displacement information and the azimuth information of the vehicle body acquired from the inertial measurement unit <NUM>. In addition, the width of the unit cover <NUM> in the front-rear direction is reduced, and thus, the antenna unit <NUM> can be formed in a compact shape.

Further, with the arrangement described above, as illustrated in <FIG> and <FIG>, only the upper cover body <NUM> made of resin is present above the GNSS antenna <NUM>, and thus, for example, unlike a case where the inertial measurement unit <NUM> is placed above the GNSS antenna <NUM>, the inertial measurement unit <NUM> is not a hindrance for reception at the GNSS antenna <NUM>, and a carrier phase (satellite positioning information) from the positioning satellite <NUM> can be reliably received.

As illustrated in <FIG> and <FIG>, a housing 27A of the wireless communication unit (an example of a wireless communicator built in the antenna unit <NUM>) <NUM> including a pair of wireless communication antennas <NUM> in the front-rear direction is fixedly coupled by fourth bolts <NUM> to one end in the longitudinal direction of the base plate <NUM> (the right end in the lateral direction of the vehicle body <NUM> with respect to the forward direction, the right end in <FIG>, the left end in <FIG>). The wireless communication antenna <NUM> of the wireless communication unit <NUM> is placed on the side opposite to the inertial measurement unit <NUM> and the GNSS antenna <NUM>, and on one end in the longitudinal direction of the base plate <NUM>.

As illustrated in <FIG>, a first predetermined distance L1 between the wireless communication antenna <NUM> of the wireless communication unit <NUM> and the central part of the inertial measurement unit <NUM> is set to <NUM> or more.

If the installation position and orientation of the above-described wireless communication unit <NUM> is elaborated, the first predetermined distance L1 from the wireless communication antenna <NUM> of the wireless communication unit <NUM> to the central part of the inertial measurement unit <NUM> can be sufficiently secured while the antenna unit <NUM> can be made compact in the longitudinal direction. As a result, it is possible to suppress radio interference between the wireless communication unit <NUM> and the inertial measurement unit <NUM> to prevent communication failure between the wireless communication unit <NUM> and the wireless communicator <NUM> of the wireless communication terminal <NUM>.

In particular, as described above, if the first predetermined distance L1 between the wireless communication antenna <NUM> of the wireless communication unit <NUM> and the central part of the inertial measurement unit <NUM> is set to <NUM> or more, the radio interference between the wireless communication unit <NUM> and the inertial measurement unit <NUM> can be suppressed more effectively.

Further, the outer periphery of the inertial measurement unit <NUM> is shielded by the metal housing 25A at many portions except for at connectors and the like, and a part of the metal hat-shaped bracket <NUM> located between the wireless communication unit <NUM> and the inertial measurement unit <NUM> functions as a shielding wall. Accordingly, radio interference between the wireless communication unit <NUM> and the inertial measurement unit <NUM> can be suppressed even more.

As illustrated in <FIG> and <FIG>, the base station antenna (an example of a wireless communicator built in the antenna unit <NUM>) <NUM> configured to receive information from the reference station <NUM> is placed at the other end in the longitudinal direction of the base plate <NUM> (the left end in the lateral direction of the vehicle body <NUM> with respect to the forward direction, the left end in <FIG>, the right end in <FIG>). As a result, the wireless communication unit <NUM>, the GNSS antenna <NUM> (the inertial measurement unit <NUM>), and the base station antenna <NUM> are placed on the base plate <NUM> in this order from the right in the lateral direction of the vehicle body <NUM> with respect to the forward direction to be arranged in a line in the lateral direction of the vehicle body <NUM>. As illustrated in <FIG>, the base station antenna <NUM> includes a base 29A including a magnet <NUM> and a round bar-shaped antenna bar 29B extending upward from the base 29A. Further, the base 29A includes a cylindrical lower base body 29a containing the magnet <NUM>, and a frustoconical upper base body 29b integrally formed with a central part of the upper surface of the lower base body 29a. Therefore, the base station antenna <NUM> is mounted on the metal base plate <NUM> by the magnetic force of the magnet <NUM>.

Further, as illustrated in <FIG> and <FIG>, a sheet metal movement restricting member <NUM> is fixedly coupled to the base plate <NUM> by fifth bolts <NUM>. The movement restricting member <NUM> is configured to restrict the movement of the base 29A of the base station antenna <NUM> by contacting or approaching, from above, a vertical middle position of the conical outer peripheral surface of the upper base body 29b in the base 29A of the base station antenna <NUM>. As illustrated in <FIG>, in an upper restricting plate piece 66a formed, in the movement restricting member <NUM>, by bending the movement restricting member <NUM>, a circular movement restricting hole 66b onto which the upper base body 29b of the base 29A fits, and a detachment notch 66c having a width dimension that allows for passage of the antenna bar 29B are continuously formed.

In the above arrangement of the base station antenna <NUM>, a separation distance between the antenna bar 29B of the base station antenna <NUM> and the wireless communication antenna <NUM> of the wireless communication unit <NUM> is large. Accordingly, it is possible to suppress radio interference between the antenna bar 29B of the base station antenna <NUM> and the wireless communication antenna <NUM> of the wireless communication unit <NUM>.

In addition, it is possible to easily mount the base station antenna <NUM> on the base plate <NUM> made of metal by the magnetic force of the magnet <NUM> provided in the base 29A. Moreover, a displacement of the base station antenna <NUM> due to vibration or the like can be reliably prevented by the movement restricting member <NUM> having a simple shape being fixed to the base plate <NUM> by bolts. The antenna unit <NUM> can be made compact by simplifying and downsizing the mounting structure of the base station antenna <NUM>.

Next, the unit cover <NUM> of the antenna unit <NUM> will be described.

As illustrated in <FIG>, a first bulge part 53A protruding upward from the upper surface position at the center in the longitudinal direction of the upper cover body <NUM> and the upper end position of the wireless communication antenna <NUM> of the wireless communication unit <NUM> is formed at one end in the longitudinal direction (the right side in the lateral direction of the vehicle body <NUM> with respect to the forward direction) of the upper cover body <NUM> of the unit cover <NUM>. Further, as illustrated in <FIG>, a second predetermined distance L2 between an inner surface 53a of the first bulge part 53A and the upper end of the wireless communication antenna <NUM> is set to <NUM> or more.

With the second predetermined distance L2 formed between the upper end of the wireless communication antenna <NUM> and the inner surface 53a of the first bulge part 53A of the upper cover body <NUM>, it is possible to improve the communication accuracy between the wireless communication unit <NUM> and the wireless communicator <NUM> of the wireless communication terminal <NUM>.

It is noted that the relationship between the first predetermined distance L1 and the second predetermined distance L2 is set to first predetermined distance L1 > second predetermined distance L2.

Further, as illustrated in <FIG>, <FIG>, and <FIG>, a second bulge part 53B, having the same shape as the first bulge part 53A formed at one end in the longitudinal direction (the right side in the lateral direction of the vehicle body <NUM> with respect to the forward direction) is formed on the other end in the longitudinal direction of the upper cover body <NUM> of the unit cover <NUM> (the left side in the lateral direction of the vehicle body <NUM> with respect to the forward direction), and thus, the unit cover <NUM> is formed in a laterally symmetrical shape. This configuration is made in consideration of the design when the antenna unit <NUM> is mounted in the upper position on the front side of the cabin <NUM> of the tractor <NUM>, but the formation of the second bulge part 53B also creates a new technical value.

That is, as illustrated in <FIG> and <FIG>, the second bulge part 53B of the upper cover body <NUM> is formed at a portion corresponding to the base station antenna <NUM>, and the total height of the base station antenna <NUM> is sufficiently larger than the height from the upper surface of the base plate <NUM> to the upper surface of the second bulge part 53B. Therefore, as illustrated in <FIG>, a through hole <NUM> through which the antenna bar 29B of the base station antenna <NUM> penetrates to protrude outward and upward is formed on the upper surface of the second bulge part 53B. A vibration-proof elastic body <NUM>, such as a tubular rubber piece contacting an outer peripheral surface of the penetrating portion of the antenna bar 29B of the base station antenna <NUM>, is attached to the periphery of the opening of the through hole <NUM>. A grommet which contacts the entire circumference of the antenna bar 29B and also exhibits water tightness is employed for the vibration-proof elastic body <NUM>.

If the vibration-proof elastic body <NUM> is not provided, an annular gap is present between the periphery of the opening of the through hole <NUM> of the second bulge part 53B and the outer peripheral surface of the penetrating portion of the antenna bar 29B. If traveling vibration of the tractor <NUM> or the like acts on the base station antenna <NUM>, the antenna bar 29B swings within the range of the annular gap, which may result in breakage of the antenna bar 29B at the root. However, in the present embodiment, as described above, since a vertical middle part of the antenna bar 29B is supported by the vibration-proof elastic body <NUM> provided in the periphery of the opening of the through hole <NUM> of the second bulge part 53B so that the support structure of the base station antenna <NUM> is a two-point support structure as a whole, it is possible to prevent the antenna bar 29B from breaking due to traveling vibration or the like.

In particular, if the second bulge part 53B is provided, the support position of the antenna bar 29B supported by the vibration-proof elastic body <NUM> is higher as it is higher from the upper surface of the base plate <NUM> to the upper surface of the second bulge part 53B, and thus, breakage of the antenna bar 29B can be further suppressed.

It is noted that, in the present embodiment, the vibration-proof elastic body <NUM> is attached in the periphery of the opening of the through hole <NUM> of the second bulge part 53B, however, the vibration-proof elastic body <NUM> may be mounted on the upper surface or the inner surface of the second bulge part 53B, or further, may be mounted on a bracket or the like provided in the base plate <NUM>.

As illustrated in <FIG> and <FIG>, a mounting space <NUM> for another unit is formed in the longitudinal direction of the base plate <NUM> between the base station antenna <NUM> and both the inertial measurement unit <NUM> and the GNSS antenna <NUM>. Here, <FIG> and <FIG> illustrate a state where another unit <NUM> is not mounted in the mounting space <NUM> and the mounting space <NUM> is a vacant space.

The other unit may be, for example, a controller for a retrofit liquid crystal monitor configured to govern a part of the autonomous traveling control, or the like. In the tractor <NUM> following the autonomous traveling specification according to the present embodiment, a liquid crystal monitor <NUM> (see <FIG>) is provided in the cabin <NUM>, and the liquid crystal monitor <NUM> is equipped with a controller configured to govern a part of the autonomous traveling control. However, if another work vehicle such as a rice transplanter following a normal specification is changed to follow the autonomous traveling specification, a controller for a retrofit liquid crystal monitor configured to govern the autonomous traveling control is required. In this case, the controller can be easily mounted by using the mounting space <NUM> secured in the base plate <NUM>.

It is noted that, in the present embodiment, a tablet terminal <NUM> in which a dedicated application for performing route generation, farm field registration, and the like is installed, is used as the liquid crystal monitor <NUM>.

Further, as illustrated in <FIG> and <FIG>, stays <NUM> bent to be formed in an inverted "L" shape (see <FIG>) in a front view of the vehicle body and formed in a substantially semi-circular shape (see <FIG>) in a side view of the vehicle body are provided at both side portions in the longitudinal direction on the lower surface of the bottom plate part 52A of the lower cover body <NUM>. The pair of left and right stays <NUM> are fixedly coupled to the base plate <NUM> by sixth bolts <NUM> via second bosses <NUM> penetrating the bottom plate part 52A of the lower cover body <NUM>.

Further, as illustrated in <FIG>, a camera <NUM> for capturing an image of the front of the vehicle body is mounted at the center position in the longitudinal direction on the lower surface of the bottom plate part 52A of the lower cover body <NUM>, and an image captured by the camera <NUM> can be displayed on the touch panel of the wireless communication terminal <NUM> via wireless communication between the wireless communication unit <NUM> of the tractor <NUM> and the wireless communicator <NUM> of the wireless communication terminal <NUM>.

It is noted that, in <FIG>, wires connected to the inertial measurement unit <NUM>, the GNSS antenna <NUM>, the wireless communication unit <NUM>, and the base station antenna <NUM> which are built on the base plate <NUM> are omitted. <FIG> illustrates a part of one harness <NUM> in which the wires are assembled in the unit cover <NUM>. As illustrated in <FIG>, the harness <NUM> is led out from a harness lead-out hole (not illustrated) formed at one end in the longitudinal direction of the lower cover body <NUM>. A grommet <NUM> is mounted on the harness lead-out hole.

Next, a mounting structure of the antenna unit <NUM> will be described.

As illustrated in <FIG>, both ends of the support frame <NUM> of the antenna unit <NUM> are fixedly coupled to mirror mounting parts <NUM> provided on left and right front pillars <NUM> constituting the cabin frame <NUM>.

As illustrated in <FIG>, in each of the left and right mirror mounting parts <NUM>, a mounting base <NUM> substantially formed in a "C" shape ( "U" shape) in a plan view is fixed to the upper part of each of the front pillars <NUM> by welding or the like, and a plate-shaped mirror mounting member <NUM> including a hinge <NUM> for rotatably supporting a support arm <NUM> of a rearview mirror <NUM> is fixedly coupled to the mounting base <NUM> by a bolt or the like. A mounting piece 153A including an upper mounting surface along a horizontal plane is bent and formed at the upper ends of the left and right mirror mounting members <NUM>.

As illustrated in <FIG>, the support frame <NUM> includes a pipe-shaped support member <NUM>, having a circular cross section, formed by bending both ends in the lateral width direction downward in a substantially inverted U-shape in a front view of the vehicle body, and mounting plates <NUM>, each including a lower mounting surface along a horizontal plane, are fixed to both ends of the pipe-shaped support member <NUM>. Both the mounting plates <NUM> of the support frame <NUM> are fixedly coupled to the upper mounting surfaces of the mounting pieces 153A of the left and right mirror mounting members <NUM> by bolts <NUM> or the like.

As described above, the left and right mirror mounting parts <NUM> are mounted on the upper part of the front pillars <NUM> of the rigid cabin frame <NUM>, and are placed at a height position close to the roof <NUM> of the cabin <NUM>. Therefore, it is possible to firmly mount the support frame <NUM> of the antenna unit <NUM> at an appropriate height position by utilizing both of the mirror mounting parts <NUM> that are sturdy and have adequate height above the ground.

In addition, the upper mounting surfaces of the mounting pieces 153A in the left and right mirror mounting members <NUM> and the lower mounting surfaces of the two mounting plates <NUM> of the support frame <NUM> are all formed as horizontal surfaces, and thus, the middle part of the pipe-shaped support member <NUM> can be easily placed along the horizontal direction, which makes it possible to reduce error in mounting of the antenna unit <NUM> mounted on the horizontal middle part of the pipe-shaped support member <NUM>.

As illustrated in <FIG>, in a state where the support frame <NUM> is laid across the left and right mirror mounting parts <NUM>, the horizontal middle part of the pipe-shaped support member <NUM> of the support frame <NUM> is horizontally placed along the lateral width direction of the vehicle body at a position near the front end of the roof <NUM> of the cabin frame <NUM>.

As illustrated in <FIG>, and <FIG>, a pair of left and right brackets <NUM> configured to support the pair of left and right stays <NUM> of the antenna unit <NUM> are fixed to the horizontal middle part of the pipe-shaped support member <NUM>. The two sets of stays <NUM> on the side of the antenna unit <NUM> and the brackets <NUM> on the side of the support frame <NUM>, which closely face each other in the lateral width direction of the vehicle body, and are pivotally coupled by a seventh bolt <NUM> serving as a horizontal pivot support shaft along the lateral width direction of the vehicle body.

Therefore, due to the pivoting movement of the antenna unit <NUM> with respect to the support frame <NUM> around the pivot support shaft of the seventh bolt <NUM>, the antenna unit <NUM> is displaceable between a normal use position (normal use posture) in which the base station antenna <NUM> protrudes upward in the vertical direction, as illustrated in <FIG>, and a non-use position (non-use posture) in which the base station antenna <NUM> is placed forward at a lower position, as illustrated in <FIG>.

In the present embodiment, the non-use position of the antenna unit <NUM> is a position obtained when the antenna unit <NUM> pivots by <NUM> degrees forward from the normal use position, and in this non-use position, the base station antenna <NUM> is in a posture of projecting forward in the horizontal direction.

Further, in the present embodiment, an operation of changing the position of the antenna unit <NUM> between the normal use position and the non-use position is performed manually, but the operation of changing the position of the antenna unit <NUM> may be performed by a drive unit such as an actuator.

As illustrated in <FIG> and <FIG>, the two sets of stays <NUM> on the side of the antenna unit <NUM> and the brackets <NUM> on the side of the support frame <NUM> are capable of fixing the antenna unit <NUM> alternately in the normal use position or the non-use position by a replacement of an eighth bolt <NUM> provided at a position offset from the seventh bolt <NUM> in a pivoting radial direction.

More specifically, as illustrated in <FIG>, one bolt insertion hole <NUM>, through which the eighth bolt <NUM> is inserted, is formed in each of the brackets <NUM> on the side of the support frame <NUM>, and bolt insertion holes <NUM> are formed in the stays <NUM> on the side of the antenna unit <NUM> at two positions coinciding with the bolt insertion hole <NUM> on the side of the brackets <NUM> when the antenna unit <NUM> is in the normal use position or the non-use position.

As illustrated in <FIG>, if the antenna unit <NUM> is in the normal use position, the base station antenna <NUM> is in a posture in which the base station antenna <NUM> is directed upward in the vertical direction, and the upper end of the base station antenna <NUM> protrudes upward from the roof <NUM> of the cabin <NUM>, as illustrated in <FIG>. However, if the base station antenna <NUM> protruding upward from the roof <NUM> of the cabin <NUM> is a hindrance during transportation of the tractor <NUM> or the like, the position of the antenna unit <NUM> is changed from the normal use position to the non-use position, as illustrated in <FIG>. In the non-use position, the base station antenna <NUM> is in a posture of protruding forward in the horizontal direction, and thus, the upward protruding height of the antenna unit <NUM> including the unit cover <NUM> can be made lower than the highest part of the roof <NUM> of the cabin <NUM>.

Whether the antenna unit <NUM> is in the normal use position can be detected based on displacement information acquired from the inertial measurement unit <NUM>. Accordingly, as illustrated in <FIG>, the control unit <NUM> includes an autonomous traveling restraint unit <NUM> configured to prohibit the start of the autonomous traveling control based on information acquired by the inertial measurement unit <NUM> and the GNSS antenna <NUM> unless it is detected that the antenna unit <NUM> is in the normal use position.

The above-described autonomous traveling restraint unit <NUM> enables the start of the autonomous traveling control only when the antenna unit <NUM> is in the normal use position. Accordingly, the vehicle body can travel autonomously and safely along the target traveling route with high accuracy based on accurate information acquired by the inertial measurement unit <NUM> and the GNSS antenna <NUM>.

It is noted that, in the present embodiment, whether the antenna unit <NUM> is in the normal use position is detected based on the displacement information acquired from the inertial measurement unit <NUM>, but whether the antenna unit <NUM> is in the normal use position may be determined based on a signal of an automatic switch for detecting a position displacement of the antenna unit <NUM> or a signal of a hard switch manually operated.

Next, a wiring structure of the harness <NUM> led out from the antenna unit <NUM> will be described.

As illustrated in <FIG> and <FIG>, the cabin frame <NUM>, in which the harness <NUM> is wired, is formed in a substantially box frame shape including the pair of left and right front pillars <NUM> located in front of the driver's seat <NUM>, a pair of left and right rear pillars <NUM> located behind the driver's seat <NUM>, a front beam member <NUM> coupling the upper ends of the front pillars <NUM>, a rear beam member <NUM> coupling the upper ends of the rear pillars <NUM>, and left and right side beam members <NUM> coupling the upper ends of the front pillars <NUM> and the rear pillars <NUM> which are arranged at the front and rear.

As illustrated in <FIG> and <FIG>, the lower end of each of the rear pillars <NUM> is coupled to an upper rear end of a fender frame <NUM> curved to bulge forward and upward in a side view to conform to the shape of a rear fender <NUM>, and a lower front end of each of the fender frames <NUM> is coupled to the rear end of a side frame <NUM> protruding rearward from a lower part of the corresponding one of the front pillars <NUM>.

As illustrated in <FIG>, the fender frame <NUM> is formed of a cylindrical frame material. In the fender frame <NUM>, the lower front end of the fender frame <NUM> located on the right side of the cabin <NUM> opens downward and outward from the cabin <NUM>, and an internal space of the fender frame <NUM> located on the right side is formed as an internal/external communication passage <NUM> communicating the inside and outside of the cabin <NUM>. A drain hose (not illustrated) for discharging condensed water in an air conditioner to the outside of the cabin <NUM> is provided in the internal/external communication passage <NUM> of the fender frame <NUM>.

Further, a windshield <NUM> is placed in a region surrounded by the left and right front pillars <NUM>, the front beam member <NUM>, and lower front plate boards <NUM>, extending inward from the lower ends of the front pillars <NUM> in the lateral direction.

As illustrated in <FIG> and <FIG>, at a right edge (an example of one side edge in the lateral width direction) on the outer surface of the windshield <NUM> of the cabin <NUM>, the harness <NUM> led out from the antenna unit <NUM> extends downward along a band-shaped part overlapping a glass receiving part 201a of the front pillar <NUM> on the right side. The harness <NUM> reaching the lower front plate board <NUM> on the lower end side of the windshield <NUM> extends rearward along the lower surface of a floor plate support plate <NUM> continuously connected to the side frame <NUM>, is then guided from the opening at the lower front end of the fender frame <NUM> located at the right side through the internal/external communication passage <NUM> into the cabin <NUM>, and is connected to the control unit <NUM> placed in an operation panel unit <NUM> on the right side.

The band-shaped part overlapping the glass receiving part 201a of the front pillar <NUM> on the right side at a right side edge on the outer surface of the windshield <NUM> is a glass attaching part for attaching the windshield <NUM> to the front part of the cabin <NUM>, and is also in a position where the band-shaped part does not interfere with a driver's vision. Therefore, when the harness <NUM> led out from the antenna unit <NUM> is placed in the above-described band-shaped part, it is possible to place the harness <NUM> having a good appearance and maintaining the visibility of an operator seated on the driver's seat <NUM> in a good condition.

Further, as illustrated in <FIG>, a protective harness cover <NUM> made of resin into which the harness <NUM> is inserted is adhered to the band-shaped part at the right side edge on the outer surface of the windshield <NUM> with an adhesive or the like. As illustrated in <FIG>, the harness cover <NUM> includes a base part <NUM> including an adhesion surface <NUM> for adhesion to the windshield <NUM> and a harness receiving surface <NUM> for receiving the harness <NUM>, and a flexible band part <NUM> that is integrally formed with one end of the base part <NUM> in the width direction, placed on the harness receiving surface <NUM> of the base part <NUM>, and curved in an arc shape along the outer peripheral surface of the base part <NUM>.

An engagement claw <NUM> is formed at the distal end of the band part <NUM>. An engagement concave part <NUM> for engagement with the engagement claw <NUM>, and a semi-circular ridge <NUM> abutting against the rear surface of the engagement claw <NUM> engaged with the engagement concave part <NUM> to restrict engagement/disengagement of the engagement claw <NUM> in the abutted state are formed in a portion at the other end side in the width direction of the harness receiving surface <NUM> of the base part <NUM>.

Therefore, as illustrated in <FIG>, if the engagement between the engagement claw <NUM> and the engagement concave part <NUM> is released, the harness <NUM> can be inserted into the harness cover <NUM> from the gap between the base part <NUM> and the band part <NUM> to arrange the harness <NUM> so that the harness receiving surface <NUM> receives a part of the outer periphery of the harness <NUM>. As illustrated in <FIG>, if the engagement claw <NUM> and the engagement concave part <NUM> are engaged, the base part <NUM> and the band part <NUM> are coupled, and the harness <NUM> can be mounted in the harness cover <NUM> in a state where the harness <NUM> is received by the harness receiving surface <NUM> over the entire circumference of the outer periphery of the harness <NUM>.

Next, the arrangement of the tablet terminal <NUM> arranged in the cabin <NUM> will be described.

As illustrated in <FIG> and <FIG>, the tablet terminal <NUM> is arranged above the front end of the operation panel unit <NUM> on the right side in the cabin <NUM>. An installation position of the tablet terminal <NUM> is on a line extending to the front of a right armrest <NUM> out of an armrest <NUM> and the armrest <NUM> arranged on both the left and right sides of the driver's seat <NUM>. Specifically, a front half part 271A of the right armrest <NUM> is configured in an inclined posture in which the front half part 271A is closer to the right toward the front end side of the front half part 271A with respect to a rear half part 271B along the front-rear direction. A main transmission lever <NUM> for increasing or decreasing the traveling speed of the tractor <NUM>, a dial-type work unit position dial <NUM> for manually changing and adjusting the height position of a work machine such as a rotary tilling machine, and the like are provided at the front half part 271A.

An operator seated in the driver's seat <NUM> typically puts an arm or elbow on the armrests <NUM> and <NUM>. Therefore, particularly, the tablet terminal <NUM> is provided on the line extending to the front of the front half part 271A of the right armrest <NUM>, and thus, it is possible to easily operate the tablet terminal <NUM> similarly to the operation on the main transmission lever <NUM>, the work unit position dial <NUM>, and the like.

Further, as illustrated in <FIG>, the tablet terminal <NUM> is arranged at a position slightly displaced to the right of the steering handle <NUM>. This arrangement position of the tablet terminal <NUM> does not hinder the forward field of view of the operator seated in the driver's seat <NUM> during working. Moreover, the operator can easily view the entirety of a liquid crystal screen 48a of the tablet terminal <NUM> by slightly turning the eyes of the operator while viewing the front for performing work.

Next, a terminal support device <NUM> configured to support the tablet terminal <NUM> will be described.

As illustrated in <FIG>, the terminal support device <NUM> includes a support strut <NUM> fixed to a side of the fender frame <NUM> on the right side of the cabin frame <NUM>, a terminal holder <NUM> configured to detachably hold the tablet terminal <NUM>, and a terminal position adjustment mechanism <NUM> configured to attach the terminal holder <NUM> to the support strut <NUM> so that the position of the terminal holder <NUM> can be adjusted three-dimensionally.

As illustrated in <FIG>, the terminal position adjustment mechanism <NUM> includes a first movable arm <NUM> attached to be pivotable around a first vertical axis Y1 (see <FIG> and <FIG>) along the vertical direction with respect to a cylindrical pipe support strut <NUM> which is a constituent member of the support strut <NUM> and is along the vertical direction, and to be adjustable in height in the direction of the first vertical axis Y1, and a second movable arm <NUM> attached to be pivotable around a second vertical axis Y2 (see <FIG> and <FIG>) along the vertical direction with respect to the distal end of the first movable arm <NUM>. The terminal holder <NUM> is attached to the distal end of the second movable arm <NUM> to be pivotable around a horizontal axis X (see <FIG> and <FIG>) along the horizontal direction. The elevation angle of the liquid crystal screen 48a of the tablet terminal <NUM> held by the terminal holder <NUM> can be adjusted by pivoting the terminal holder <NUM> around the horizontal axis X.

As illustrated in <FIG>, a substantially rectangular mounting plate <NUM> is fixed to the lower end of the pipe support strut <NUM> of the support strut <NUM>. The mounting plate <NUM> is fixed by bolts <NUM> to a substantially U-shaped first bracket <NUM> that is fixed to the fender frame <NUM> on the right side.

Further, as illustrated in <FIG> and <FIG>, a slit <NUM> is formed along the direction of the first vertical axis Y1 at the upper end of the pipe support strut <NUM>, and coupling members <NUM> bent to be formed into a U-shape are fixed to both sides of the slit <NUM>. As illustrated in <FIG>, an adjustment bolt <NUM> is inserted across both of the coupling members <NUM>, and a nut <NUM> is screwed to the distal end portion of a male screw part of the adjustment bolt <NUM>. With a screwing operation of the adjustment bolt <NUM> and the nut <NUM> to be screwed, the coupling members <NUM> are close to each other, and the inner diameter of the upper end part of the pipe support strut <NUM> is reduced. As a result, as illustrated in <FIG>, a first shaft member <NUM> on the proximal end side of the first movable arm <NUM> slidably inserted into the upper end part of the pipe support strut <NUM> is clamped and fixed, and thus, the orientation around the first vertical axis Y1 of the first shaft member <NUM> and the height position in the direction of the first vertical axis Y1 of the first movable arm <NUM> are fixed.

As illustrated in <FIG> and <FIG>, the first shaft member <NUM> is configured in which a first boss receiving part <NUM> that is bent to be formed in a U-shape is fixed to the upper end of a tubular shaft part <NUM> inserted into the upper end part of the pipe support strut <NUM>. As illustrated in <FIG>, a tubular first boss part 360A formed at the proximal end of the first movable arm <NUM> is inserted and arranged between a first upper plate part 363a and a first lower plate part 363b of the first boss receiving part <NUM>. As illustrated in <FIG>, a first support shaft <NUM> penetrating the first boss part 360A is provided across the first upper plate part 363a and the first lower plate part 363b of the first boss receiving part <NUM>. A first nut <NUM> is screwed onto the male screw part on the upper end of the first support shaft <NUM>. The first boss part 360A of the first movable arm <NUM> is configured to be rotatable around the first vertical axis Y1 being the axial center of the first support shaft <NUM> with respect to the first boss receiving part <NUM> of the first shaft member <NUM>, and is configured to be freely fixed in any orientation around the first vertical axis Y1.

As illustrated in <FIG>, a second boss receiving part <NUM> bent to be formed into a U-shape is fixed to an upper end of a tubular second boss part 360B formed at the distal end of the first movable arm <NUM>.

A tubular third boss part <NUM> formed at the proximal end of the second movable arm <NUM> is inserted and arranged between a second upper plate part 370a and a second lower plate part 370b of the second boss receiving part <NUM>. As illustrated in <FIG> and <FIG>, a second support shaft <NUM> penetrating the third boss part <NUM> is provided across the second upper plate part 370a and the second lower plate part 370b of the second boss receiving part <NUM>, and a second nut <NUM> is screwed onto the male screw part on the upper end of the second support shaft <NUM>. The third boss part <NUM> of the second movable arm <NUM> is configured to be rotatable with respect to the second boss receiving part <NUM> of the first movable arm <NUM> around the second vertical axis Y2 being the axial center of the second support shaft <NUM>, and is configured to be freely fixed in any orientation around the second vertical axis Y2.

As illustrated in <FIG>, the second movable arm <NUM> includes the third boss part <NUM> arranged along the direction of the second vertical axis Y2, a fourth boss part <NUM> arranged along the direction of the horizontal axis X, and a continuous part <NUM> configured to integrally join the two boss parts <NUM> and <NUM>. A second bracket <NUM> substantially formed in a U-shape in a plan view, is fixed to a lower end of the rear surface of the terminal holder <NUM>. As illustrated in <FIG>, <FIG>, and <FIG>, the fourth boss part <NUM> of the second movable arm <NUM> is inserted and arranged between left and right side plates 321a of the second bracket <NUM>. A third support shaft <NUM> penetrating the fourth boss part <NUM> is provided across both of the side plates 321a of the second bracket <NUM>. A third nut (not illustrated) is screwed onto the male screw part at one end of the third support shaft <NUM>. The second bracket <NUM> of the terminal holder <NUM> is configured to be rotatable with respect to the fourth boss part <NUM> of the second movable arm <NUM> around the horizontal axis X being the axial center of the third support shaft <NUM>, and is configured to be freely fixed in any orientation around the horizontal axis X.

As described above, the position and orientation of the tablet terminal <NUM> held by the terminal holder <NUM> can be three-dimensionally adjusted in accordance with individual users having different height, posture, and habits by adjusting the orientation around the first vertical axis Y1 and the height in the direction of the first vertical axis Y1 of the first movable arm <NUM> with respect to the support strut <NUM>, adjusting the orientation of the second movable arm <NUM> around the second vertical axis Y2 with respect to the first movable arm <NUM>, and adjusting the orientation of the terminal holder <NUM> around the horizontal axis X with respect to the second movable arm <NUM>.

Further, in a state where the first movable arm <NUM> is fixed to the support strut <NUM>, the second movable arm <NUM> is fixed to the first movable arm <NUM>, and the terminal holder <NUM> is fixed to the second movable arm <NUM>, the rigidity of the terminal position adjustment mechanism <NUM> is sufficiently ensured, and the influence of a vibration on the tablet terminal <NUM> mounted on the terminal holder <NUM> can be minimized. Further, the support strut <NUM> is attached to the cabin frame <NUM> provided with vibration countermeasures, and thus, it is possible to suppress the influence of the vibration on the tablet terminal <NUM>.

As illustrated in <FIG>, the terminal holder <NUM> includes a fixed holder part <NUM> configured to support the lower end of the tablet terminal <NUM> and a movable holder part <NUM> configured to support the upper end of the tablet terminal <NUM>. The movable holder part <NUM> is configured to be slidable in the vertical direction along the fixed holder part <NUM>. As illustrated in <FIG> and <FIG>, a holding urging part <NUM> configured to move and urge the movable holder part <NUM> is provided between the movable holder part <NUM> and the fixed holder part <NUM>, on the lower side being the holding side of the tablet terminal <NUM>.

As illustrated in <FIG>, the fixed holder part <NUM> includes a fixed mounting base <NUM> formed by bending left and right side plates 331a forward and upward and having a substantially U-shaped cross section, a fixed support plate <NUM> fixed across the lower end of the two side plates 331a of the fixed mounting base <NUM>, and the second bracket <NUM> fixed to the lower end of the rear surface of the fixed mounting base <NUM>.

As illustrated in <FIG>, a lower support part <NUM> including a mounting plate part 334a configured to mount and support the lower end of the tablet terminal <NUM>, and a retaining plate part 334b protruding upward from the tip end of the mounting plate part 334a are formed at both side portions in the lateral direction of the fixed support plate <NUM>. The fixed support plate <NUM> and the two lower support parts <NUM> form a lower catch concave part <NUM> for inserting the lower end of the tablet terminal <NUM> from above, and an elastic buffer material <NUM> such as silicone sponge rubber is attached to the inner surface of the lower catch concave part <NUM>.

As illustrated in <FIG>, in the movable holder part <NUM>, a pair of left and right side plates <NUM> slidable in the vertical direction along the inner surface of the two side plates 331a of the fixed mounting base <NUM> are fixed to the rear surface of a movable support plate <NUM>. An upper support part <NUM>, including a holding plate part 343a configured to hold and support the upper end of the tablet terminal <NUM> and a retaining plate part 343b protruding downward from the tip end of the holding plate part 343a, is formed at the upper end of the movable support plate <NUM>. The movable support plate <NUM> and the upper support part <NUM> form an upper catch concave part <NUM> for inserting the upper end of the tablet terminal <NUM> from below, and the elastic buffer material <NUM> such as the silicone sponge rubber is attached to the inner surface of the upper catch concave part <NUM>.

The vibration of the tablet terminal <NUM> mounted on the terminal holder <NUM> can be suppressed by the elastic buffer material <NUM> provided in the lower catch concave part <NUM> of the fixed holder part <NUM>, and the elastic buffer material <NUM> provided in the upper catch concave part <NUM> of the movable holder part <NUM>.

As illustrated in <FIG>, long holes <NUM> configured to restrict the movable range of the movable support plate <NUM> are formed on the two side plates <NUM> of the movable support plate <NUM>. On the two side plates 331a of the fixed mounting base <NUM>, two slide guide rods <NUM> are horizontally arranged to penetrate the long holes <NUM> of the two side plates <NUM> of the movable support plate <NUM>. Therefore, the position where the upper ends of the two long holes <NUM> of the movable holder part <NUM> contact the upper slide guide rod <NUM> of the fixed holder part <NUM> is the lowest position of the movable holder part <NUM> with respect to the fixed holder part <NUM>. The position where the lower ends of the two long holes <NUM> of the movable holder part <NUM> contact the lower slide guide rod <NUM> of the fixed holder part <NUM> is the highest position of the movable holder part <NUM> with respect to the fixed holder part <NUM>.

As illustrated in <FIG>, the holding urging part <NUM> includes a lower spring hooking member <NUM> arranged horizontally on the lower ends of the two side plates 331a of the fixed mounting base <NUM>, an upper spring hooking member <NUM> arranged horizontally on the lower ends of the two side plates <NUM> of the movable support plate <NUM>, and a tension coil spring <NUM> retained between the two spring hooking members <NUM> and <NUM>. With the tension coil spring <NUM>, the movable holder part <NUM> is urged to move to the lowest position with respect to the fixed holder part <NUM>.

Therefore, when the tablet terminal <NUM> is mounted on the terminal holder <NUM>, the upper end of the tablet terminal <NUM> is inserted from below the upper catch concave part <NUM> of the movable holder part <NUM> and in this state, the movable holder part <NUM> is pushed upward against the elastic urging force of the tension coil spring <NUM>. When the lower end of the tablet terminal <NUM> exceeds the upper end of the lower catch concave part <NUM> of the fixed holder part <NUM>, the lower end of the tablet terminal <NUM> is inserted into the two lower catch concave parts <NUM> of the fixed holder part <NUM>. In this mounted state, the tablet terminal <NUM> is securely held by the elastic urging force of the tension coil spring <NUM> at three points, that is, the two lower catch concave parts <NUM> of the fixed holder part <NUM> and the upper catch concave part <NUM> of the movable holder part <NUM>.

The upper end of the pipe support strut <NUM> of the support strut <NUM> faces the upper front end of the operation panel unit <NUM>. Furthermore, the first shaft member <NUM> of the first movable arm <NUM> penetrates the upper front end of the operation panel unit <NUM>. As illustrated in <FIG>, a through hole 390a communicating with the opening of the operation panel unit <NUM> is also formed in a device mounting member <NUM> fixed to the upper front end of the operation panel unit <NUM>. The opening of the operation panel unit <NUM> and the through hole 390a of the device mounting member <NUM> are formed in a size that allows for operation of the adjustment bolt <NUM> inserted into the two coupling members <NUM> of the pipe support strut <NUM> and the nut <NUM>, using a hand, a finger, or a tool from above and from the outside.

Further, a flexible rubber cover <NUM> covering the through hole 390a of the device mounting member <NUM> is provided. If the rubber cover <NUM> is rolled up, the through hole 390a of the device mounting member <NUM> is exposed.

Claim 1:
A work vehicle (<NUM>) comprising a cabin (<NUM>), a support frame (<NUM>), an antenna unit (<NUM>),
whereby the support frame (<NUM>) extends in a lateral width direction and is fixed to a cabin frame (<NUM>) at an upper position outside the cabin (<NUM>),
and whereby the antenna unit (<NUM>), in which an inertial measurement unit (<NUM>), a GNSS antenna (<NUM>), and a wireless communicator (<NUM>) are built, is attached to the support frame (<NUM>) in a state where the inertial measurement unit (<NUM>) and the GNSS antenna (<NUM>) are basically placed at a center position in the lateral width direction of a vehicle body, and
whereby the antenna unit (<NUM>) is attached to the support frame (<NUM>) to be displaceable from a normal use position, in which the antenna unit (<NUM>) protrudes above a roof of the cabin (<NUM>), to a lower non-use position, in which the antenna unit (<NUM>) is lower than a highest part of the roof.