Work vehicle

Abstract

To provide a work vehicle capable of reliably delivering an emission wave emitted from an emission portion to a scheduled region in front of a vehicle body.SOLUTION: A work vehicle 1 includes a travelable vehicle body 3 and an emitting portion 30 that emits an emitted wave toward a scheduled region RA in front of the vehicle body 3, where the vehicle body 3 has a frame 20 extending in a front-rear direction, a weight 26 is mounted on a front portion of the frame 20, and the emitting portion 30 overlaps the weight 26 in projection when viewed from a direction orthogonal to a left-right direction, and the emission region SA through which the emitted wave passes is disposed at a position where the emission region SA reaches the scheduled region RA while dodging the weight 26.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a work vehicle.

Background Art

[0002] The work vehicle disclosed in Patent Document 1 includes a travelable vehicle body. The vehicle body has a headlight disposed on the leading side in the forward direction. The headlight illuminates a planned area located in front of the vehicle body with light that is an emission wave emitted by itself (hereinafter referred to as headlight light), so that an operator can grasp the situation within the planned area.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in order to prevent the front side from rising during work (to achieve driving stability during work), this type of work vehicle is provided with a weight at the center in the vehicle width direction at the front position of the vehicle body (the foremost end in the forward direction of the work vehicle). In this way, when the weight is disposed at the foremost end in the forward direction of the work vehicle, the weight is located in front of the headlight, so depending on the irradiation angle of the headlight, the weight may interfere and block the headlight light. That is, not all of the emission wave emitted from the emission unit toward the planned area may reach the planned area.

[0005] The headlight is an emission device having a light source as an emission unit that emits headlight light as an emission wave. The problem that the emission wave emitted from the emission unit is blocked by the weight can also occur in a laser scanner that irradiates laser light as the emission wave or a sonar that emits (oscillates) ultrasonic waves as the emission wave. That is, a laser scanner or a sonar may be adopted to detect the presence or absence of obstacles or the like in a planned area in front of the vehicle body. However, when a weight is arranged in the front, the emission wave is blocked by the weight, and not all of the emission wave emitted from the emission unit can be utilized for detection, which may reduce the detection accuracy.

[0006] The present invention has been made to solve such problems of the prior art, and an object thereof is to provide a work vehicle capable of surely delivering an emission wave emitted from an emission unit to a planned area in front of the vehicle body.

Means for Solving the Problems

[0007] A work vehicle according to an aspect of the present invention includes a travelable vehicle body and an emission device having an emission unit that emits an emission wave toward a planned area in front of the vehicle body. The vehicle body has a frame extending in the front-rear direction, and a weight is attached to the front end portion of the frame. The emission unit is arranged at a position where, when viewed from a direction orthogonal to the left-right direction, it projects onto the weight and the emission area through which the emitted emission wave passes bypasses the weight and reaches the planned area.

[0008] The emission unit may be provided at a distance from the weight at least either in front or above.

[0009] The frame supports a prime mover and a bonnet that covers the prime mover. The bonnet covers at least above the weight, and the emission unit may be provided below the front end portion of the bonnet.

[0010] The emission unit is a light source of a headlamp that emits irradiation light as the emission wave for illuminating the planned area, and the emission area of the irradiation light that expands from the light source toward the planned area on the ground is set at a position that avoids the weight, and may be provided so as to reach the planned area.

[0011] A laser scanner device including the emission unit that emits a laser as the emission wave, the laser scanner device irradiates the planned area with the laser as the emission wave and detects obstacles included in the planned area, and the emission unit is provided such that the laser scanned within the emission area that expands from the emission unit toward the planned area passes while avoiding the weight and reaches the planned area.

[0012] A sonar device including the emission unit that emits a sound wave as the emission wave, the sonar device irradiates the planned area with the sound wave as the emission wave and detects obstacles included in the planned area, and the emission area of the sound wave that expands from the emission unit toward the planned area is set at a position that avoids the weight and is provided so as to reach the planned area.

Advantages of the Invention

[0013] According to the present invention, the emission wave emitted from the emission unit can surely reach the planned area in front of the vehicle body.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] As shown in FIGS. 1 and 2, the work vehicle 1 can be connected to a work device 2 that performs a predetermined agricultural operation. Accordingly, FIGS. 1 and 2 show a state in which the work device 2 is connected to the work vehicle 1. That is, the work vehicle 1 shown in FIGS. 1 and 2 is a so-called tractor, and in the following description, the tractor 1 will be described as an example.

[0017] In the following description, the straight-ahead direction (the direction of forward and backward travel) of the tractor 1 is defined as the front-rear direction. On this premise, the forward side is referred to as the front, and the backward side is referred to as the rear. Also, in FIG. 1, the front-rear direction is additionally shown as arrow A3, the front is additionally shown as arrow A1, and the rear is additionally shown as the direction of arrow A2. Further, the left side is referred to as the left with reference to the forward direction (the field of view of the operator OP riding on the tractor 1), and the right side is referred to as the right with reference to the forward direction. Furthermore, the direction orthogonal to the forward direction and the up-down direction is referred to as the left-right direction or the width direction.

[0018] The tractor 1 (work vehicle 1) includes a travelable vehicle body 3, a prime mover 4, and a transmission 5. That is, the tractor 1 includes a traveling device 7 that supports the vehicle body 3 so as to be travelable. Further, the tractor 1 includes a PTO drive device that extracts the output of the prime mover 4 (not shown in the figure). The traveling device 7 is of a tire type and has front wheels 7F and rear wheels 7R. Note that the traveling device 7 is not limited to the tire type and may be a crawler type. The prime mover 4 can employ an engine (diesel engine, gasoline engine), an electric motor, etc. In the present embodiment, a diesel engine is employed as the prime mover 4. The transmission 5 can switch the driving force of the traveling device 7 by shifting gears and can also switch between forward and reverse of the traveling device 7.

[0019] As shown in FIG. 2, a driver's seat 10 is provided on the vehicle body 3. The driver's seat 10 is protected by a protective device 9. The protective device 9 employs a cabin that protects the driver's seat 10, or a ROPS (canopy) that protects the driver's seat 10 by covering at least the upper part of the driver's seat 10. In the present embodiment, the protective device 9 is a cabin.

[0020] As shown in FIG. 2, the protective device 9 includes a plurality of columns 9a fixed to the vehicle body 3 and a roof 9b supported by the plurality of columns 9a and disposed above the driver's seat 10. When the protective device 9 is a cabin, glass, a door, etc. are provided between the plurality of columns 9a, and the driver's seat 10 is covered by the glass, the door, etc. A fender 13 is attached below the protective device 9, and the fender 13 covers the upper part of the rear wheel 7R.

[0021] As shown in FIG. 1, the vehicle body 3 has a frame 20. The frame 20 includes a left frame 20L provided on the left side and a right frame 20R provided on the right side. The left frame 20L and the right frame 20R each extend forward from the side of the transmission 5 and extend in the front-rear direction. The left frame 20L and the right frame 20R are spaced apart in the left-right direction (width direction) and support the lower part of the prime mover 4. The front end portion of the left frame 20L and the front end portion of the right frame 20R are connected by a front connecting plate 20F. The middle portion of the left frame 20L and the middle portion of the right frame 20R are connected by an intermediate connecting plate 20M. The left frame 20L and the right frame 20R support the front axle case 29. A front axle for rotatably supporting the front wheels 7F is accommodated in the front axle case 29. That is, in the case of this embodiment, the frame 20 is a front axle frame that supports the front axle. Note that the frame 20 may be a frame that supports a structure other than the front axle case 29 (a frame other than the front axle frame).

[0022] As shown in FIGS. 1 and 2, the vehicle body 3 includes a bonnet 25 that covers the prime mover 4 on the frame 20. That is, a bonnet 25 is provided above the prime mover 4 on the frame 20. The bonnet 25 extends in the front-rear direction and the width direction. The bonnet 25 is disposed at the center in the width direction in front of the protection device 9. Specifically, the bonnet 25 includes a left side wall 25L provided on the left side with respect to the prime mover 4, a right side wall 25R provided on the right side with respect to the prime mover 4, and an upper wall portion 25U that connects the upper portions of the left side wall 25L and the right side wall 25R and is located above the prime mover 4. The left side wall 25L, the right side wall 25R, and the upper wall portion 25U define an engine room that houses the prime mover 4. In addition to the prime mover 4, a cooling fan, a radiator, a battery, etc. are housed in the engine room. The front wheels 7F are respectively disposed on the left outer side of the left side wall 25L and the right outer side of the right side wall 25R. In this embodiment, the bonnet 25 also covers the weight 26 described later from above.

[0023] The PTO drive device has a PTO shaft protruding from the rear part of the vehicle body 3, transmits the output of the prime mover 4 to the working device 2 via the PTO shaft, and drives the working device 2.

[0024] A connecting device 8 is provided at the rear part of the vehicle body 3. The connecting device 8 is a device for detachably connecting the working device (implement, etc.) 2 to the vehicle body 3. The connecting device 8 is a swing drawbar that connects the working device 2 and the vehicle body 3 and does not raise and lower the working device 2, a three-point link mechanism that raises and lowers the working device 2, or the like. The working device 2 is a tilling device for tilling, a fertilizer spreading device for spreading fertilizer, a pesticide spraying device for spraying pesticides, a harvesting device for harvesting, a ridging device for making ridges, a mowing device for mowing grass, etc., a spreading device for spreading grass, etc., a grass collecting device for collecting grass, etc., a forming device for forming grass, etc. The working device 2 shown in FIG. 1 etc. is a tilling device for tilling.

[0025] As shown in FIG. 3, the connecting device 8 of the present embodiment is a three-point link mechanism for raising and lowering the working device 2. Specifically, as shown in FIG. 3, the connecting device 8 has a lift arm 8a, a lower link 8b, a top link 8c, a lift rod 8d, and a lift cylinder 8e. Each of the lift arm 8a, the lower link 8b, and the top link 8c extends in the front-rear direction. The front end portion of the lift arm 8a is supported so as to be swingable in the vertical direction above the rear end of the transmission 5 (a transmission case that houses a transmission mechanism). The lift arm 8a swings (raises and lowers) by the drive of the lift cylinder 8e. The lift cylinder 8e is composed of a hydraulic cylinder. The lift cylinder 8e is connected to a hydraulic pump via a control valve (not shown). The control valve is a solenoid valve or the like and expands and contracts the lift cylinder 8e.

[0026] The front end of the lower link 8b is supported by the lower rear part of the transmission 5 (transmission case) so as to be swingable in the vertical direction. The front end of the top link 8c is supported by the rear part of the transmission 5 (transmission case) above the lower link 8b so as to be swingable in the vertical direction. The lift rod 8d connects the lift arm 8a and the lower link 8b. The working device 2 is connected to the rear end of the lower link 8b and the rear end of the top link 8c. When the lift cylinder 8e is driven (extended or retracted), the lift arm 8a moves up and down, and the lower link 8b connected to the lift arm 8a via the lift rod 8d also moves up and down. As a result, the working device 2 swings (moves up and down) vertically with the front end of the lower link 8b as a fulcrum.

[0027] Note that the tractor 1 may be provided with a position detection device that detects its own position (positioning information including latitude and longitude) by means of a satellite positioning system or the like. The position detection device may be mounted on the roof 9b of the protection device 9, or may be mounted on the working device 2 such as the tillage device described above. Further, the position detection device may have an inertial measurement device such as a gyro sensor or an acceleration sensor.

[0028] As described above, since the working device 2 is connected to the connection device 8 provided at the rear part of the vehicle body 3, a large load (load) acts on the rear side during work (travel) of the work vehicle 1. In order to prevent the front wheel side from lifting due to the load or load on the working device 2, the tractor 1 is provided with a weight 26 disposed at the center in the vehicle width direction at the front position of the vehicle body 3 (the foremost end in the forward direction of the work vehicle 1). Specifically, as shown in FIG. 4, the tractor 1 has a weight 26 attached to the front parts of the left frame 20L and the right frame 20R. Specifically, the weight 26 is attached to a weight bracket (weight attachment portion) 27 provided at the front part of the vehicle body 3. The weight bracket 27 is attached to the front connection plate 20F of the frame 20 by a fastening tool such as a bolt. Accordingly, the weight 26 is located below the front end of the bonnet 25. As shown in FIG. 4, the width of the weight 26 in the left-right direction in the present embodiment is the same as or substantially the same as the width of the bonnet 25 in the same direction. That is, the left side surface 26L of the weight 26 is located below the left side wall 25L of the bonnet 25, and the right side surface 26R of the weight 26 is located below the right side wall 25R of the bonnet 25. By thus corresponding the width of the bonnet 25 and the width of the weight 26, the weight 26 of the present embodiment is wider than a general weight.

[0029] The tractor 1 includes an emitting device having an emitting portion 30 that emits an emitted wave. The emitting portion of the emitting device is disposed below the front end portion of the bonnet 25. That is, the tractor 1 includes an emitting device including an emitting portion 30 that emits an emitted wave having a predetermined wavelength, and by emitting the emitted wave from the emitting portion toward a planned area, a predetermined function is exhibited. The tractor 1 of the present embodiment includes, as the emitting device, a headlamp (lighting device), a laser scanner device that detects an obstacle, and a sonar device that detects an obstacle.

[0030] These emitting devices emit an emitted wave (light, laser, sound wave) from the emitting portion toward a planned area RA set in front of the vehicle body.

[0031] Specifically, the headlamp (lighting device) has, as the emitting portion, a light source that emits visible light as the emitted wave (hereinafter, the visible light emitted forward from the headlamp is referred to as headlamp light), and emits irradiation light as the emitted wave from the emitting portion toward a planned area RA set in front of the vehicle body. The laser scanner device has, as the emitting portion 30, a light projecting portion 32 that oscillates the laser light as the emitted wave in a scanning manner forward, and emits a laser scanning line as the emitted wave from the emitting portion 30 toward a planned area RA set in front of the vehicle body. The sonar device has, as the emitting portion 30, a vibrator 33 that oscillates a sound wave (ultrasonic wave), and emits a sound wave as the emitted wave from the emitting portion 30 toward a planned area RA set in front of the vehicle body.

[0032] In any of these emission devices, the emission unit 30 is disposed between the bonnet 25 and the weight 26. That is, as shown in FIG. 4, in the tractor 1 of the present embodiment, the emission units (left light source 31L and right light source 31R) of the headlamp, the emission unit (light projection unit 32) of the laser scanner device, and the emission unit (vibrator 33) of the sonar device are each disposed below the front end portion of the bonnet 25. These emission units 30 emit emission waves to a planned area RA located in front of the vehicle body 3. However, since the emission devices have different uses respectively, the position and range of the planned area RA are set individually.

[0033] Specifically, as the emission unit 30 (light source) 31 of the headlamp, two lamps are provided at intervals in the left - right direction at an intermediate position in the vertical direction between the front end portion of the bonnet 25 and the weight 26, and a total of four lamps are provided on the left and right. The emission unit 30 (light source) 31 of the headlamp includes a left light source 31L provided on the left side (leftward) in the front portion of the bonnet 25 and a right light source 31R provided on the right side (rightward) in the front portion of the bonnet 25. Both the left light source 31L and the right light source 31R are composed of LEDs (or halogen bulbs).

[0034] The emission unit (light projection unit) 32 of the laser scanner device is disposed below the middle portion in the width direction at the front end portion of the bonnet 25. That is, the emission unit (light projection unit) 32 of the laser scanner device is disposed between the front end portion of the bonnet 25 and the weight 26 and at the middle portion in the width direction. Specifically, the emission unit (light projection unit) 32 of the laser scanner device is disposed between the left light source 31L and the right light source 31R. The laser scanner device includes a laser detection unit that detects the reflected light of the laser emitted toward the planned area RA from the emission unit (light projection unit) 32, and determines the presence or absence of an obstacle in the planned area RA based on the detection result of the detection unit. The laser detection unit of the laser scanner device is unitized integrally with the emission unit (light projection unit) 32 and is disposed below the front end portion of the bonnet 25 together with the emission unit (light projection unit) 32. As shown in FIG. 4, the emission unit (vibrator) 33 of the sonar device is disposed below the front end portion of the bonnet 25. In the present embodiment, the emission unit (vibrator) 33 of the sonar device is between the front end portion of the bonnet 25 and the weight 26 and is disposed below the headlamps (right light source 31R and left light source 31L). The emission unit (vibrator) 33 of the sonar device is provided one on each of the left side (left) and the right side (right) with the center in the width direction of the bonnet 25 as a boundary, and a total of two units are provided. That is, the sonar device has a left vibrator 33L provided below the left side of the front end portion of the bonnet 25 and a right vibrator 33R provided below the right side of the front end portion of the bonnet 25. The sonar device includes, in addition to the vibrator 33 (left vibrator 33L, right vibrator 33R), an oscillator that outputs high-frequency power, and a receiver that receives a reflected wave of the sound wave transmitted by the vibrator 33 (left vibrator 33L, right vibrator 33R). The vibrator (left vibrator 33L, right vibrator 33R) oscillates ultrasonic vibration by the high-frequency power output from the oscillator, and determines the presence or absence of the obstacle B based on the reflected wave received by the receiver. Accordingly, the receiver of the sonar device is provided below the front end portion of the bonnet 25 in the same manner as the vibrator (left vibrator 33L, right vibrator 33R). Note that the vibrator 33 and the receiver are configured as an integral unit. One unit is provided on each of the left side (left) and the right side (right) with the center in the width direction of the bonnet 25 as a boundary, and a total of two units are provided. That is, the sonar device has a left vibrator 33L provided below the left side of the front end portion of the bonnet 25 and a right vibrator 33R provided below the right side of the front end portion of the bonnet 25. The sonar device includes, in addition to the vibrator 33 (left vibrator 33L, right vibrator 33R), an oscillator that outputs high-frequency power, and a receiver that receives a reflected wave of the sound wave transmitted by the vibrator 33 (left vibrator 33L, right vibrator 33R). The vibrator (left vibrator 33L, right vibrator 33R) oscillates ultrasonic vibration by the high-frequency power output from the oscillator, and determines the presence or absence of the obstacle B based on the reflected wave received by the receiver. Accordingly, the receiver of the sonar device is provided below the front end portion of the bonnet 25 in the same manner as the vibrator (left vibrator 33L, right vibrator 33R). Note that the vibrator 33 and the receiver are configured as an integral unit.

[0035] As described above, the emission unit 30 (right light source 31R, left light source 31L) of the headlamp, the emission unit (light projecting unit 32) of the laser scanner device, and the emission unit (vibrator 33) of the sonar device are located above the weight 26 and are disposed within the range of the width direction of the weight 26 when viewed in the front-rear direction. That is, when viewed from the front (or rear) as shown in FIG. 4, the emission unit 30 (right light source 31R, left light source 31L) of the headlamp, the emission unit (light projecting unit 32) of the laser scanner device, and the emission unit (vibrator 33) of the sonar device are disposed at positions that projectively overlap the bonnet 25 and the weight 26 when viewed from the vertical direction.

[0036] The planned area RA is the range where the emitted wave should reach. The size and position of the planned area RA are set according to the type of the emitted wave. For example, compared with headlight illumination or laser light, the sound wave has a shorter reachable distance, and the planned area RA of the sound wave is arranged at a position near the vehicle body 3. Headlight illumination and laser light have a longer reachable distance compared with the sound wave, and the planned area RA is arranged at a position farther forward from the vehicle body 3.

[0037] Next, the planned area RA will be described by dividing it into two cases: when considered two-dimensionally along a plane (vertical plane) parallel to the vertical direction and the front-rear direction, and when considered two-dimensionally along a plane (horizontal plane) parallel to the left-right direction and the front-rear direction.

[0038] FIG. 5 shows the planned area RA viewed along a plane (vertical plane) parallel to the vertical direction and the front-rear direction. As shown in FIG. 5, when the headlight illumination is emitted from the emission unit 30, the range L1 in the front-rear direction of the planned area RA is between the first point P1 on the ground that is separated from the emission unit (light source) 30 by a predetermined distance forward and the second point P2 located on the ground further forward of the first point P1 (a point separated from the first point P1 by a defined distance α).

[0039] As shown in FIG. 5, the lower limit line X1 extending from the emission unit 30, which is the light source of the headlight, to the first point P1 indicates the irradiation path of the headlight illumination passing through the position closest to the tractor 1 within the irradiation range of the headlight illumination. The headlight illumination does not reach the area behind the lower limit line X1. That is, the lower limit line X1 indicates the boundary line closest to the tractor 1 among the boundary lines defining the irradiated area and the non-irradiated area of the headlight illumination.

[0040] The upper limit line X2 extending from the emission unit 30, which is the light source of the headlight, to the second point P2 indicates the irradiation path of the headlight illumination passing through the position farthest forward from the tractor 1 within the irradiation range of the headlight illumination. The headlight illumination does not reach the area in front of the upper limit line X2. That is, the upper limit line X2 indicates the boundary line farthest from the tractor 1 among the boundary lines defining the irradiated area and the non-irradiated area of the headlight illumination.

[0041] The angle formed by the lower limit line X1 and the upper limit line X2 means the irradiation angle of the headlamp having the left light source 31L and the right light source 31R which are the light emitting parts 30. The headlamp is equipped with a lens or a mirror that can emit the headlight generated by the left light source 31L and the right light source 31R at the above-described irradiation angle. and is equipped with a lens or a mirror that can emit the headlight generated at the above-described irradiation angle.

[0042] The optical axis line X3 that bisects the lower limit line X1 and the upper limit line X2 and extends to the intermediate point PA between the first point P1 and the second point P2 is the optical axis of the headlight. At the intermediate point PA, the optical axis line X3 is in contact with the ground, and the headlight spreads in an elliptical shape (elongated in the front-rear direction) on the ground centered on the intermediate point PA to illuminate the ground.

[0043] FIG. 6 shows the planned area RA as seen along a plane (horizontal plane) parallel to the left-right direction and the front-rear direction. As shown in FIG. 6, when the headlight is emitted from the light emitting part 30, the planned area RA spreads in an elliptical shape centered on the intermediate point PA where the optical axis line X3 contacts the ground. Since the position of the intermediate point PA of the tractor 1 of the present embodiment is located in front of the light emitting part 30, a planned area RA having an elliptical shape elongated in the front-rear direction is formed on the ground centered on the intermediate point PA. In this case, the first point P1 is behind the intermediate point PA, and the second point P2 is in front of the intermediate point PA.

[0044] Note that in the tractor 1 of the present invention, the position of the intermediate point PA does not necessarily have to be located in front of the light emitting part 30. The intermediate point PA may be in front of the light emitting part 30 and may be slightly shifted outward in the left-right direction.

[0045] As described above, the headlight of the tractor 1 of the present embodiment has two right light sources 31R and two left light sources 31L respectively as the emission unit 30. The planned areas RA of the two right light sources 31R, 31R coincide or substantially coincide, and the planned areas RA of the two left light sources 31L, 31L coincide or substantially coincide. In contrast, the planned areas RA are set for the right light source 31R and the left light source 31L respectively. The two planned areas RA spread elliptically around the respective intermediate points PA with a distance in the left - right direction. In the present embodiment, the two planned areas RA overlap in the left - right direction, but the two planned areas RA may not overlap.

[0046] Both of the two planned areas RA have a first side end point P4 at the right outer edge in the left - right direction and a second side end point P5 at the left outer edge in the left - right direction. The distance between the first side end point P4 and the second side end point P5 in each planned area RA is L2, and the distance L2 is shorter than the distance L1 described above.

[0047] As described above, the planned area RA is for the case where the emission unit 30 emits headlight light (when the emission unit 30 has the left light source 31L and the right light source 31R). However, when the emission unit 30 emits a laser in a scanning manner (when the emission unit 30 is the light projecting unit 32 of the laser scanner device) or when the emission unit 30 oscillates ultrasonic waves (when the emission unit 30 is the vibrator 33 of the sonar device), the planned area RA is different.

[0048] For example, when a laser is emitted in a scanning manner from the light projecting unit 32 of the laser scanner device which is the emission unit 30, the planned area RA is provided at a certain height above the ground in order to detect an obstacle B existing at a position higher than the ground by the laser.

[0049] Therefore, when the obstacle B is the detection target, the planned area RA to be irradiated with the laser is virtually set at a position higher than the ground according to the height of the obstacle B. The planned area RA is at the same height as the obstacle B or a value lower than the height of the obstacle B.

[0050] Note that the planned area RA shown in FIG. 8 is used when detecting the obstacle B, and is virtually set for the state where the obstacle B is detected.

[0051] In addition, when ultrasonic waves are oscillated from the vibrator 33 of the sonar device which is the emission unit 30, since the range where sound waves propagate is often shorter than that of electromagnetic waves, the planned area RA shown in FIG. 8 is set near the emission unit 30 rather than the planned area RA.

[0052] The emission area SA is the range through which the planned area RA described above and the headlight illumination emitted from the left light source 31L or the right light source 31R which is the emission unit 30 pass. The emission area SA is formed so as to expand in a conical shape with the respective light sources 31L, 31R as vertices toward the planned area RA from the left light source 31L or the right light source 31R.

[0053] When viewed in the direction along the vertical plane as shown in FIG. 5, the emission area SA is shown as a triangular area surrounded by the lower limit line X1 connecting the left light source 31L and the right light source 31R (emission unit 30) and the first point P1, the line X2 connecting the emission unit 30 and the second point P2, and the line GL indicating the ground. In other words, the emission area SA in the case of FIG. 5 is a triangular area connecting the three points of the first point P1, the second point P2, and the emission unit 30.

[0054] When viewed in the direction along the horizontal plane as shown in FIGS. 6 and 9, the left emission area SA is an area surrounded by the first line X4 and the second line X5 extending in the tangential direction from the left light source 31L to the outer edge of the left planned area RA (the wedge-shaped area in FIG. 6), and the area from the first side end point P4 to the second side end point P5 via the second point P2 (the U-shaped area in FIG. 6) (the area shown as a teardrop shape in FIG. 6). The right emission area SA is an area surrounded by the third line X6 and the fourth line X7 extending in the tangential direction from the right light source 31R to the outer edge of the right planned area RA (the wedge-shaped area in FIG. 6), and the area from the first side end point P4 to the second side end point P5 via the point P2 (the U-shaped area in FIG. 6) (the area shown as a teardrop shape in FIG. 6).

[0055] Now, in order for the emission region SA of the emission wave emitted from the emission unit 30 toward the planned region RA to reach the planned region RA while avoiding the weight 26, the emission unit 30 needs to be arranged at a position where the weight 26 is not included in the above-described emission region SA.

[0056] As shown in FIG. 5, since the emission region SA of the emission wave exists in front of the lower limit line X1, if the emission unit 30 is arranged at a position where the weight 26 exists behind the lower limit line X1, the weight 26 will not be included in the emission region SA. That is, the "position where the emission region SA reaches the planned region RA while avoiding the weight 26" is nothing other than a position where the weight 26 exists behind the lower limit line X1.

[0057] Specifically, in order to prevent the weight 26 from being included in the emission region SA, the position of the emission unit 30 is moved upward relative to the weight 26, or the position of the emission unit 30 is moved backward relative to the weight 26.

[0058] As shown in FIG. 7, if the position of the weight 26 in the tractor 1 shown on the left in the figure is lowered by ΔH downward as in the tractor 1 shown on the right in the figure, the position of the emission unit 30 can be relatively moved upward with respect to the weight 26. In this way, the vertical distance between the emission unit 30 and the weight 26 is increased, and the position of the weight 26 can be further lowered with respect to the lower limit line X1 that slopes upward and backward, so that it is possible to more surely suppress the weight 26 from being included in the emission region SA.

[0059] As shown in FIG. 2, if the bonnet 25 is extended forward so that the bonnet 25 is located further forward than the weight 26 with respect to the position of the weight 26 in the front-rear direction, the position of the emission part 30 can be moved further forward relative to the weight 26. In this way, the distance in the front-rear direction between the emission part 30 and the weight 26 is increased, and the position of the weight 26 can be further retracted rearward with respect to the lower limit line X1 that slopes upward and rearward. Therefore, it is possible to more reliably prevent the weight 26 from being included in the emission region SA.

[0060] That is, the emission part 30 is preferably provided at a distance from the weight 26 at least either in the front or in the upper direction or both. In this way, since the emission part 30 is arranged at a distance from the weight 26 at least either in the front or in the upper direction or both, the emission region SA through which the emitted emission wave passes is separated from the weight 26, making it easier for the emission region SA to avoid the weight 26 and easier for the total amount of the emission wave to reach the planned region RA.

[0061] In addition, when the emission part 30 is the left light source 31L and the right light source 31R, it is necessary to be visible from the operator OP seated in the driver's seat.

[0062] As shown in FIG. 5, when the viewpoint of the operator OP seated in the driver's seat is PO, consider the line of sight LS that extends from the viewpoint PO through the upper surface of the bonnet 25 to the ground. When the emission region SA avoids the weight 26, if the emission part 30 is arranged at a position where the weight 26 exists behind the line of sight LS, the weight 26 will not be included in the emission region SA. Since the line of sight LS is often located in front of the lower limit line X1, if the weight 26 exists behind the lower limit line X1, it often satisfies the relationship with the line of sight LS. However, in the tractor 1 with a high viewpoint PO or the tractor 1 with a low bonnet 25, the position of the line of sight LS may be in front of the lower limit line X1. Therefore, it is necessary to arrange the emission part 30 so as to satisfy not only the relationship with the lower limit line X1 but also the relationship with the line of sight LS.

[0063] Next, when the emission unit 30 includes at least one of the laser scanner device and the sonar device, consider the arrangement of the emission unit 30 such that the laser emission region TA avoids the weight 26 and reaches the planned region RA.

[0064] Hereinafter, when the emission unit 30 includes at least one of the laser scanner device and the sonar device, the description will focus on the configuration different from the case of the left light source 31L and the right light source 31R, and the same reference numerals will be given to the common configurations and the detailed description will be omitted.

[0065] The emission unit 30 has a laser scanner device that detects an obstacle B included in the planned region RA by irradiating a laser as an emission wave. Further, the emission unit 30 may have a sonar device that detects an obstacle by oscillating a sound wave as an emission wave.

[0066] The weight 26 is disposed outside the emission region TA that extends in a scanning manner from the laser scanner device toward the obstacle B or the emission region UA of the sound wave that expands from the sonar device toward the obstacle.

[0067] Unlike the headlight illumination as the emission wave, the laser is a wave with high directivity and is less likely to expand compared to sound waves. However, when detecting the obstacle B included in the planned region RA, since the laser is irradiated in a scanning manner toward the planned region RA, considering the scanning state, the laser forms an emission region TA that expands as it approaches the planned region RA. That is, even when the emission unit 30 has a laser scanner device, an emission region TA that expands toward the planned region RA is formed in the same manner as the emission region SA of the headlight illumination.

[0068] Also, similar to when irradiated from the headlight, when detecting the obstacle B included in the planned region RA, the sound wave forms an emission region UA that expands toward the planned region RA. That is, even when the emission unit 30 has a sonar device, an emission region UA that expands toward the planned region RA is formed in the same manner as the emission region SA of the headlight illumination.

[0069] That is, when the emitting unit 30 includes at least one of a laser scanner device and a sonar device, the emission regions TA and UA are shaped to expand toward the planned region RA. Therefore, in order for the emission regions TA and UA to avoid the weight 26 and reach the planned region RA, it is necessary to provide the emitting unit 30 at a distance from the weight 26 in at least one of the front and upper directions, similar to the case of the left light source 31L and the right light source 31R.

[0070] A preferred embodiment of the present invention provides a work vehicle described in the following items.

[0071] (Item 1) A work vehicle 1 comprising a travelable vehicle body 3 and an emitting device having an emitting unit 30 that emits an emission wave toward a planned region RA in front of the vehicle body 3. The vehicle body 3 has a frame 20 extending in the front-rear direction, and a weight 26 is attached to the front end portion of the frame 20. The emitting unit 30 is arranged at a position where, when viewed from a direction orthogonal to the left-right direction, it projects onto the weight 26 and the emission region SA through which the emitted emission wave passes avoids the weight 26 and reaches the planned region RA.

[0072] (Function and effect) According to the work vehicle 1 according to this Item 1, although the emitting unit 30 projects onto the weight 26 when viewed from a direction orthogonal to the left-right direction, the emission region SA through which the emitted emission wave passes is arranged at a position that avoids the weight 26 and reaches the planned region RA. Therefore, the emission wave can surely reach the planned region RA in front of the vehicle body 3.

[0073] (Item 2) The work vehicle 1 according to Item 1, wherein the emitting unit 30 is provided at a distance from the weight 26 in at least one of the front and upper directions.

[0074] According to the work vehicle 1 related to this item 2, since the emission unit 30 is arranged at a distance from the weight 26 in at least one of the front and upper directions, the emission area SA through which the emitted emission wave passes is less likely to hit the weight 26, and the emission wave is more likely to reach the planned area RA.

[0075] (Item 3) The frame 20 supports the prime mover 4 and the bonnet 25 that covers the prime mover 4. The bonnet 25 covers at least the upper part of the weight 26, and the emission unit 30 is provided below the front end of the bonnet 25. The work vehicle 1 according to Item 1 or Item 2.

[0076] According to the work vehicle 1 related to this item 3, the bonnet 25 can be positioned above or in front of the weight 26, and the position of the emission unit 30 provided at the front of the bonnet 25 can be positioned at least above or in front of the weight 26. Therefore, it is easier to avoid the weight 26 and make the emission wave reach the planned area RA. In addition, since the emission unit 30 is composed of electrical and electronic devices that require waterproofing, if the emission unit 30 is attached to the front of the bonnet 25, the bonnet 25 can also provide waterproofing for the emission unit 30.

[0077] (Item 4) The emission unit 30 is the light sources 31L and 31R of the headlamps that emit the irradiation light as the emission wave for illuminating the planned area RA. The emission area SA of the irradiation light that expands from the light sources 31L and 31R toward the planned area RA on the ground is set at a position that avoids the weight 26 and is provided so as to reach the planned area RA. The work vehicle 1 according to any one of Items 1 to 3.

[0078] (Function and effect) According to the work vehicle 1 related to this item 4, the irradiation light from the left light source 31L and the right light source 31R which are the emission parts 30 does not hit the weight 26. Therefore, in the work vehicle 1 of the present invention, the ground in front of the vehicle body 3 can be irradiated by the left light source 31L and the right light source 31R which are the emission parts 30 without being obstructed by the weight 26.

[0079] (Item 5) A laser scanner device including the emission part (light projecting part 32) that emits a laser as the emission wave, which irradiates the planned area RA with the laser as the emission wave and detects an obstacle B included in the planned area RA. The emission part (light projecting part 32) is provided such that the laser scanned within the emission area TA that expands from the emission part (light projecting part 32) toward the planned area RA bypasses the weight 26 and reaches the planned area RA. The work vehicle 1 according to any one of Items 1 to 4.

[0080] (Function and effect) According to the work vehicle 1 related to this item 5, the laser irradiated from the laser scanner device does not hit the weight 26. Therefore, in the work vehicle 1 of the present invention, an obstacle B in front of the vehicle body 3 can be detected by the laser scanner device without being obstructed by the weight 26.

[0081] (Item 6) A sonar device including the emission part (vibrator 33) that emits a sound wave as the emission wave, which irradiates the planned area RA with the sound wave as the emission wave and detects an obstacle B included in the planned area RA. The emission part (vibrator 33) is provided such that the emission area SA of the sound wave that expands from the emission part (vibrator 33) toward the planned area RA is set at a position that bypasses the weight 26 and reaches the planned area RA. The work vehicle 1 according to any one of Items 1 to 5.

[0082] According to the work vehicle 1 related to this item 6, the sound wave oscillated from the sonar device does not hit the weight 26. Therefore, in the work vehicle 1 of the present invention, the sonar device can detect the obstacle B in front of the vehicle body 3 without being obstructed by the weight 26.

[0083] As described above, the present invention has been described. However, it should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Signs

[0084] 1 Tractor (Work Vehicle) 2 Working Device 3 Vehicle Body 4 Prime Mover 20 Frame 25 Bonnet 26 Weight 30 Emission Unit 31 Irradiation Unit 32 Laser Scanner 33 Sonar RA Planned Region SA Emission Region TA Operation Region UA Emission Region

Claims

1. A work vehicle comprising: a travelable vehicle body; and a transmitting device having a transmitting portion that transmits an outgoing wave toward a planned area in front of the vehicle body. The vehicle body has a frame extending in the front-rear direction, a weight is attached to the front end portion of the frame, and the transmitting portion is disposed at a position where, when viewed from a direction orthogonal to the left-right direction, it projects and overlaps with the weight, and the outgoing area through which the transmitted outgoing wave passes bypasses the weight and reaches the planned area.

2. The work vehicle according to claim 1, wherein the transmitting portion is provided at a distance from the weight, either in front or above the weight, or both.

3. The frame supports a prime mover and a bonnet that covers the prime mover, the bonnet covers at least above the weight, and the transmitting portion is provided below the front end portion of the bonnet. The work vehicle according to claim 1.

4. The transmitting portion is a light source of a headlamp that irradiates irradiation light as the outgoing wave that illuminates the planned area, and the outgoing area of the irradiation light that expands from the light source toward the planned area on the ground is set at a position that bypasses the weight and is provided so as to reach the planned area. The work vehicle according to claim 1.

5. A laser scanner device including the transmitting portion that transmits a laser as the outgoing wave, the laser scanner device irradiating the planned area with the laser as the outgoing wave and detecting obstacles included in the planned area, wherein the transmitting portion is provided so that the laser scanned within the outgoing area that expands from the transmitting portion toward the planned area bypasses the weight and reaches the planned area. The work vehicle according to claim 1.

6. A sonar device including the transmitting portion that transmits a sound wave as the outgoing wave, the sonar device irradiating the planned area with the sound wave as the outgoing wave and detecting obstacles included in the planned area, wherein the transmitting portion is provided so that the outgoing area of the sound wave that expands from the transmitting portion toward the planned area is set at a position that bypasses the weight and reaches the planned area. The work vehicle according to claim 1. ​

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