JP2016202140A - Farm work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a vehicle height of a travel machine body to be adjusted, in a farm work vehicle configured to spray a liquid chemicals by supplying the liquid chemicals from a liquid chemicals tank mounted on the travel machine body to a spray nozzle of a liquid chemicals spray part via a power spray pump.SOLUTION: The farm work vehicle of the present invention comprises: a machine body frame 2 constituting a travel machine body 1; an axle case 13 supporting right/left wheels 3; and a suspension device 110 suspending the axle case 13 on the machine body frame 2. The suspension device 110 includes: a compression spring 111 and a damper 112 damping a ground surface reaction force from both wheels 3; and a spring seat body 113 abutting on one edge side of the compression spring 111. The spring seat body 113 is configured to change a position along an expansion/contraction direction of the compression spring 111.SELECTED DRAWING: Figure 10

Description

  The present invention relates to a farm vehicle such as a speed sprayer that sprays a chemical solution in an orchard or the like.

  2. Description of the Related Art Conventionally, a speed sprayer, which is an example of an agricultural vehicle, is configured to supply and spray chemical liquid from a chemical tank mounted on a traveling machine body to a spray nozzle of a chemical liquid spraying section via a power spray pump (for example, Patent Documents). See 1 and 2 etc.). This type of speed sprayer includes a suspension device for suspending an axle case on a body frame. For example, a suspension device provided in a speed sprayer described in Patent Document 1 includes a compression spring and a damper that attenuate ground reaction force from left and right wheels. In this case, a large impact component of the ground reaction force is absorbed by the compression spring, and a small impact component such as repetitive vibration is attenuated by the damper, thereby ensuring the riding comfort and running performance of the speed sprayer.

JP2013-248929A Japanese Patent No. 4718663

  However, in the suspension device described in Patent Document 1, since the initial spring length of the compression spring is always constant, the body load (sprung load) fluctuates according to the amount of the chemical in the chemical tank, and the vehicle height of the traveling aircraft Goes up and down. For this reason, when spraying chemicals in orchards, etc., the amount of chemical in the chemical tank decreases, the vehicle height of the traveling aircraft rises, and the traveling aircraft may come into contact with the tree branches and inadvertently drop the fruit. there were.

  The present invention has been made as a technical problem to provide an agricultural work vehicle that has been improved by examining the current situation as described above.

  The invention of claim 1 is an agricultural work vehicle comprising a machine body frame that constitutes a traveling machine body, an axle case that supports left and right wheels, and a suspension device that suspends the axle case on the machine body frame. A compression spring and a damper for attenuating ground reaction force from the two wheels; and a spring seat that abuts against one end of the compression spring, the position of the spring seat being changed along the direction of expansion and contraction of the compression spring. It is configured to be possible.

  According to a second aspect of the present invention, in the agricultural vehicle according to the first aspect, an actuator for moving the spring seat along the expansion / contraction direction of the compression spring, and a detector for detecting an amount of an object mounted on the traveling machine body. And a control device that drives the actuator based on detection information of the detector, and the position of the spring seat body is changed according to the amount of the load mounted on the traveling machine body.

  According to a third aspect of the present invention, in the agricultural vehicle according to the second aspect, the traveling machine body is equipped with a chemical liquid tank for storing a chemical liquid, and the detector detects the amount of the chemical liquid in the chemical liquid tank. .

  According to the present invention, in a farm vehicle including an airframe frame that constitutes a traveling airframe, an axle case that supports left and right wheels, and a suspension device that suspends the axle case on the airframe frame, the suspension device includes the both A compression spring and a damper that attenuates ground reaction force from the wheel; and a spring seat that abuts on one end of the compression spring, the position of the spring seat being changeable along the expansion and contraction direction of the compression spring. Since it is configured, the initial spring length of the compression spring and hence the biasing force can be adjusted by the movement of the spring seat along the expansion / contraction direction of the compression spring, and after considering the body load (sprung load) It becomes possible to adjust the vehicle height of the traveling machine body.

  In particular, according to the invention of claim 2, an actuator for moving the spring seat along the expansion / contraction direction of the compression spring, a detector for detecting the amount of an object mounted on the traveling machine body, and detection information of the detector And the spring seat body is repositioned in accordance with the amount of the load mounted on the traveling machine body, so that the spring seat is interlocked with the change in the load amount. By changing the position of the body, the vehicle height of the traveling machine body can be kept constant regardless of the change in the load amount, that is, the body load (sprung load).

It is a left view of the speed sprayer in an embodiment. It is a top view of a speed sprayer. It is a top view inside a cabin. It is a schematic plan view of a steering system. It is a power transmission system diagram of a speed sprayer. It is a schematic explanatory drawing of an engine and a pressure accumulation type fuel injection device. It is the perspective view which looked at the suspension apparatus from the front upper side. It is the perspective view which looked at the suspension apparatus of the state which omitted the body frame from the front upper side. It is the perspective view which looked at the suspension apparatus from back lower side. It is a top view of a suspension apparatus. It is side surface sectional drawing of a suspension apparatus. It is a functional block diagram of a controller. It is a flowchart of vehicle height adjustment control. It is a functional block diagram of the controller in another example.

  Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings when applied to a speed sprayer as a farm vehicle.

  First, the outline of the speed sprayer will be described with reference to FIGS. The traveling machine body 1 of the speed sprayer in the embodiment is supported by a pair of left and right rear wheels 4 as well as a pair of left and right front wheels 3 as a traveling unit. A cabin 5 is arranged in the front part of the traveling machine body 1. A chemical solution tank 6 for storing a chemical solution is disposed behind the cabin 5 in the traveling machine body 1 (a front and rear halfway part of the traveling machine body 1). An engine room 7 is arranged behind the chemical tank 6 in the traveling machine body 1. A diesel engine 8 (hereinafter simply referred to as an engine) and a power spray pump 9 are mounted in the engine room 7. A PTO transmission case 20 for transmitting power from the engine 8 to the power spray pump 9 and the like is attached to the rear portion of the engine 8. A chemical solution spraying part 10 and a blower fan 11 are arranged at the rear part of the traveling machine body 1 (behind the engine room 7). A traveling mission case 12 for shifting the power from the engine 8 is mounted below the chemical tank 6. The power spray pump 9 and the blower fan 11 are driven by the power of the engine 8, the chemical liquid is sucked from the chemical liquid tank 6 by the power spray pump 9, and the chemical liquid is sprayed from the chemical liquid spraying unit 10. The sprayed chemical liquid is diffused in a field such as an orchard by the air blown from the blower fan 11 and is sprayed on the fruit tree or the like.

  A front axle case 13 is provided at the front lower part of the substantially frame-shaped body frame 2 constituting the traveling body 1. Front wheels 3 are rotatably attached to the left and right sides of the front axle case 13. A rear axle case 14 is provided at the rear lower part of the body frame 2. The rear wheels 4 are rotatably attached to the left and right sides of the rear axle case 14. The traveling mission case 12 is connected to the front axle case 13 via a front wheel transmission shaft 15 extending forward and capable of transmitting power, and is connected to the rear axle case 14 via a rear wheel transmission shaft 16 extending rearward. doing. Power from the engine 8 via the PTO transmission case 20 is changed in the traveling transmission case 12, and the left and right front wheels 3 are driven via the front wheel transmission shaft 15 and the front axle case 13 by the transmission output, and the rear wheel transmission shaft 16 and The left and right rear wheels 4 are configured to be driven via the rear axle case 14 (configured to be capable of four-wheel drive).

  As shown in FIGS. 2 and 3, a control seat 21 on which an operator is seated and a control handle 22 for steering the left and right front wheels 3 or the front and rear four wheels 3 and 4 are arranged inside the cabin 5. . An instrument panel 24 for displaying an engine tachometer, a fuel gauge, and the like is disposed on the upper rear side of the dashboard 23 disposed in front of the steering handle 22. On the rear right side of the dashboard 23, a two-wheel steering mode switch 25 and a four-wheel steering mode switch 26 for switching the left and right front wheels 3 and the left and right rear wheels 4 between a two-wheel steering mode and a four-wheel steering mode, and an engine speed And a throttle lever 29 which is a rotation speed operation tool for setting and holding the. Each mode switch 25, 26 is a switch with a lamp. In the following description, for convenience, the two-wheel steering mode is referred to as a 2WS mode, and the four-wheel steering mode is referred to as a 4WS mode.

  Below the dashboard 23, an accelerator pedal 30 that increases and decreases the engine speed based on the set rotational speed of the throttle lever 29, a brake pedal 31 that brakes the traveling machine body 1, and traveling for power interruption A clutch pedal 32 for disengaging the clutch 84 (see FIG. 5) is disposed. A side column 33 provided on the left side of the control seat 21 switches between a parking brake lever 34 for maintaining the left and right rear wheels 4 in a braking state, and a driving method for the front wheels 3 and the rear wheels 4 between two-wheel drive and four-wheel drive. A drive switching lever 35 to be operated, a main transmission lever 36 for operating forward, stop, reverse, and vehicle speed of the traveling machine body 1 and a sub-transmission operating tool as an auxiliary transmission operating tool for switching the output of the traveling mission case 12 between low speed and high speed. A shift lever 37 is disposed.

  As shown in FIGS. 2 and 4, the front axle case 13 is provided with a front wheel steering cylinder 41 for changing the direction of the left and right front wheels 3. Regardless of whether the 2WS mode or the 4WS mode is executed, the front wheel steering cylinder 41 is expanded and contracted according to the turning operation of the steering handle 22, so that the left and right front wheels 3 are connected to the kingpin 44 via the tie rod 42 and the knuckle arm 43. Change direction (turn) in the same direction around. That is, the steering angle (steering angle) of the left and right front wheels 3 is changed in proportion to the steering angle (rotation operation amount) of the steering handle 22.

  The rear axle case 14 is provided with a rear wheel steering cylinder 45 for changing the direction of the left and right rear wheels 4. When executing the 4WS mode, the left and right rear wheels 4 are moved around the kingpin 48 through the tie rod 46 and the knuckle arm 47 by extending and retracting the rear wheel steering cylinder 45 according to the turning operation of the steering handle 22. Change direction (turn). That is, the steering angle (steering angle) of the left and right rear wheels 4 is changed in proportion to the steering angle (rotation operation amount) of the steering handle 22. In this case, the steering angles of the left and right rear wheels 4 are opposite in phase to the steering angles of the left and right front wheels 3.

  Next, the power transmission system of the speed sprayer will be described mainly with reference to FIG. A flywheel housing 71 is fixed to the rear surface side of the cylinder block 50 (see FIGS. 8 and 10 to 12). A flywheel 72 is disposed in the flywheel housing 71. A flywheel 72 is directly connected to the rear end side of the engine output shaft 70 protruding forward and backward from the engine 8. The power of the engine 8 is taken out through the flywheel 72. The PTO mission case 20 is detachably attached to the rear side of the flywheel housing 71. A flywheel 72 is connected to a mission input shaft 73 in the PTO mission case 20. The PTO mission case 20 of the embodiment protrudes from the engine 8 downward to the right. From the overhanging portion of the PTO mission case 20, a main shaft 74 that transmits power to the traveling mission case 12 and a pump PTO shaft 75 that drives the power spray pump 9 protrude forward. Further, from the PTO mission case 20, a fan PTO shaft 76 that drives the blower fan 11 protrudes backward. The PTO mission case 20 constitutes a power take-out unit that takes out the power of the engine 8 via the flywheel 72.

  In the PTO mission case 20, the transmission input shaft 73, the main transmission gear mechanism 77 that transmits the power transmitted to the mission input shaft 73 to the main driving shaft 74 and the pump PTO shaft 75, and the transmission input shaft 73 are transmitted. A sub-transmission gear mechanism 78 that transmits the power to the fan PTO shaft 76 via the fan clutch mechanism 79 is disposed. The power from the engine 8 is branched and transmitted to a system from the mission input shaft 73 to the main transmission gear mechanism 77 and a system from the mission input shaft 73 to the sub-transmission gear mechanism 78. The power transmitted to the main transmission gear mechanism 77 is further branched and transmitted to a system directed to the main drive shaft 74 and a system directed to the pump PTO shaft 75. The power transmitted from the main transmission gear mechanism 77 to the pump PTO shaft 75 is transmitted to the pump shaft (not shown) of the power spray pump 9 via the pulley and belt transmission system 80 to drive the power spray pump 9. The sub-transmission gear mechanism 78 can be switched between two stages of high speed and low speed. The power transmitted from the mission input shaft 73 to the sub-transmission gear mechanism 78 via the fan clutch mechanism 79 is appropriately shifted by the sub-transmission gear mechanism 78 and then transmitted to the fan PTO shaft 76 to drive the blower fan 11.

  The traveling mission case 12 located in front of the engine 8 and below the chemical tank 6 has a main transmission input shaft 82 that receives power from the main driving shaft 74 via a transmission shaft 81 having universal shaft joints at both ends, A stirring PTO shaft 83 for driving a stirring blade (not shown) and a traveling output shaft 17 for transmitting power to the front wheel transmission shaft 15 and the rear wheel transmission shaft 16 are provided. The main transmission input shaft 82 projects rearward from the traveling mission case 12, and the main driving shaft 74 projecting forward from the overhanging portion of the PTO mission case 20 transmits power to the main transmission input shaft 82 via the transmission shaft 81. The stirring PTO shaft 83 protrudes forward from the traveling mission case 12. The travel output shaft 17 protrudes from both front and rear sides of the travel mission case 12. A front wheel transmission shaft 15 is connected to the front end side of the travel output shaft 17 via a universal shaft joint, and a rear wheel transmission shaft 16 is connected to the rear end side of the travel output shaft 17 via a universal shaft joint.

  In the traveling mission case 12, a power transmission traveling clutch 84, and a main transmission transmission shaft 85 connected to the front end side of the main transmission input shaft 82 (part in the traveling mission case 12) via the traveling clutch 84. The main transmission gear mechanism 86 and the auxiliary transmission gear mechanism 87 for shifting the power via the PTO mission case 20, the agitating PTO shaft 83 and the traveling output shaft 17 are arranged. The power transmitted from the main transmission input shaft 82 to the main transmission transmission shaft 85 via the travel clutch 84 is branched and transmitted to a system toward the stirring PTO shaft 83 and a system toward the main transmission gear mechanism 86. The power transmitted from the main transmission transmission shaft 85 to the stirring PTO shaft 83 is transmitted to the stirring shaft (not shown) of the stirring blade in the chemical liquid tank 6 via the pulley and the belt transmission system 88 to drive the stirring blade. . The power directed from the main transmission transmission shaft 85 to the main transmission gear mechanism 86 is appropriately shifted by the main transmission gear mechanism 86 and the auxiliary transmission gear mechanism 87 and then transmitted to the travel output shaft 17. Then, the transmission power transmitted to the travel output shaft 17 is transmitted to the front wheel differential gear mechanism 18 in the front axle case 13 via the front wheel transmission shaft 15 to drive the left and right front wheels 3 and the rear wheel transmission shaft 16. To the rear wheel differential gear mechanism 19 in the rear axle case 14 to drive both the left and right rear wheels 4.

  Next, the engine 8 and its peripheral structure will be described with reference to FIGS. The engine 8 mounted on the traveling machine body 1 includes a cylinder block 50 with a cylinder head 51 fastened on the upper surface. An exhaust manifold 52 is provided on one side surface of the cylinder head 51. The exhaust pipe 53 connected to the exhaust port side of the exhaust manifold 52 is connected to a diesel particulate filter 54 (hereinafter referred to as a collection filter) which is a post-processing device. The collection filter 54 collects particulate matter (PM) and the like in the exhaust gas. Although not shown, the collection filter 54 of the embodiment has a structure in which an oxidation catalyst such as platinum and a honeycomb structure are arranged in series in a substantially cylindrical filter case in a casing made of a heat-resistant metal material. It has become. Exhaust gas discharged from each cylinder of the engine 8 to the exhaust manifold 52 is purified through the collection filter 54 and then released to the outside of the machine.

  As shown in FIG. 6 and the like, the engine 8 is provided with a pressure accumulation type fuel injection device 55 (common rail type fuel injection device) as fuel supply means. The accumulator fuel injector 55 includes a plurality of injectors 56 (fuel injection valves) that inject high-pressure fuel into each cylinder of the engine 8, a common rail 57 (accumulation chamber) that accumulates high-pressure fuel and distributes the fuel to each injector 56, A supply pump 60 that pressurizes the fuel sucked from the fuel tank 58 mounted on the traveling machine body 1 through the fuel filter 59 to a high pressure and feeds the fuel to the common rail 57 is provided.

  Each injector 56 is connected to a common rail 57 via an individual high-pressure pipe 61. While each injector 56 is opening and operating, high-pressure fuel pumped from the common rail 57 is configured to be injected toward the combustion chamber of each cylinder. A pressure sensor 62 that detects internal pressure (fuel pressure in the common rail 57) is attached to the common rail 57. The supply pump 60 is driven by the power of the engine 8 and has a pressure control electromagnetic valve 63 that adjusts the amount of fuel pumped to the common rail 57. The pressure control solenoid valve 63 controls the common rail internal pressure by adjusting the fuel pumping amount to the common rail 57 by increasing or decreasing the fuel return amount from the supply pump 60 to the fuel tank 58. The fuel injection pressure of each injector 56 is substantially equal to the common rail internal pressure. For this reason, the injection pressure of each injector 56 is indirectly controlled by the control of the common rail internal pressure by the pressure control electromagnetic valve 63.

  Each injector 56, common rail 57 and supply pump 60 are connected to a fuel tank 58 via a return pipe 64. A pressure limiter valve 65 is provided between the common rail 57 and the return pipe 64 to prevent the common rail internal pressure from increasing more than necessary. A pressure control electromagnetic valve 63 is provided between the supply pump 60 and the return pipe 64. Excess fuel in each injector 56, common rail 57 and supply pump 60 is returned to the fuel tank 58 through a return pipe 64.

  The accumulator fuel injection device 55 performs main injection near the top dead center (TDC). In addition to the main injection, the accumulator type fuel injection device 55 performs a small amount of pilot injection for the purpose of reducing NOx and noise at a time approximately 60 ° before the top dead center, or for the purpose of reducing noise. Pre-injection is performed at a time immediately before top dead center, or after injection and post-injection for the purpose of reducing particulate matter and promoting exhaust gas purification are performed at a time after top dead center.

  Next, the detailed structure of the suspension device 110 for suspending the front axle case 13 on the body frame 2 will be described with reference to FIGS. The body frame 2 includes a pair of left and right front frames 101 formed in an inverted U shape when viewed from the side. The left and right front frames 101 are connected to each other by a plurality of beam frames 102 that are horizontally long. The left and right front frames 101 and the ends of the beam frames 102 are fixed by welding. The left and right front frames 101 straddle the front axle case 13 from above. In other words, the front axle case 13 is located in the inverted U-shaped recessed portions of the left and right front frames 101.

  A swing plate 103 that supports the front axle case 13 so as to swing up and down is disposed at the lower part between the left and right front frames 101. A bifurcated arm portion 104 extending rearward is provided at the rear portion of the swing plate 103. The rear end sides of the corresponding arm portions 104 are pivotally supported on the rear inner surface sides of the left and right front frames 101 so as to be rotatable. The rotation axes of both arm portions 104 are located on the same axis extending in the left-right direction. Accordingly, the swing plate 103 can swing up and down with the rear end sides of both arm portions 104 as fulcrums.

  A front portion of the swing plate 103 extends so as to cover the front axle case 13. A front fulcrum body 105 projecting forward from the left and right intermediate portion on the front side of the front axle case 13 is pivotally supported on the front portion of the swing plate 103 so as to be rotatable. On the other hand, a relay shaft 106 that transmits power to the front wheel differential gear mechanism 18 in the front axle case 13 is provided in a rearward projecting manner at the left and right intermediate portions on the rear surface side of the front axle case 13. A boss portion 107 that pivotally supports the relay shaft 106 in the front axle case 13 is pivotally supported on a rear fulcrum support 108 that is bolted to the lower surface side of the swing plate 103. The front fulcrum body 105 and the boss portion 107 (including the relay shaft 106) of the front axle case 13 are located on the same axis extending in the front-rear direction. Accordingly, the front axle case 13 can be rotated up and down (rolling) with the left and right intermediate portions (the front fulcrum body 105 and the boss portion 107 of the front axle case 13) as fulcrums. When there is a difference in the ground pressure between the left and right front wheels 3, the front axle case 13 is turned up and down around the middle of the left and right, and the left and right front wheels 3 are raised and lowered in opposite directions. As a result, the ground pressures of the left and right front wheels 3 are maintained substantially equal.

  Needless to say, the front axle case and the left and right front wheels 3 can swing up and down together with the swing plate 103 with the rear end sides of both arm portions 104 as fulcrums. The relay shaft 106 is connected to the front end side of the front wheel transmission shaft 15 via a universal shaft joint. The rotational power transmitted to the front wheel transmission shaft 15 is transmitted to the front wheel differential gear mechanism 18 in the front axle case 13 via the relay shaft 106.

  A gate-shaped frame 109 having a substantially portal shape when viewed from the front is provided at an upper portion between the left and right front frames 101. A pair of left and right suspension devices 110 are disposed between the portal frame 109 and the swing plate 103. Each suspension device 110 includes a compression spring 111 and a damper 112 that damp ground reaction force from the left and right front wheels 3 via the front axle case 13, and an upper spring seat 113 that contacts the upper end side (one end side) of the compression spring 111. And.

  In the embodiment, a pair of left and right through holes are formed in the upper surface plate of the portal frame 109, and a damper bracket 114 having a U-shaped cross section is erected around each through hole. A damper 112 is inserted into each through hole, and a cylinder side end portion of the damper 112 is rotatably connected to an upper side of the damper bracket 114 by a horizontally long pivot pin 115. The swing plate 103 is formed with a pair of left and right lower spring seats 116 corresponding to the through holes on the portal frame 109 side. Each lower spring seat portion 116 is formed with a through hole, and a rod side end portion of the corresponding damper 112 is inserted. The rod side end portion of each damper 112 is connected to the lower surface side of the swing plate 103 so as to be rotatable by a laterally long pivot pin 117.

  A compression spring 111 is fitted on the outer peripheral side of the damper 112. The compression spring 111 is located between the upper surface plate of the portal frame 109 and the lower spring seat portion 116 of the swing plate 103. An upper spring seat 113 that is in contact with the upper end side of the compression spring 111 is fitted under the upper surface plate of the portal frame 109 of the damper 112. The lower end side (the other end side) of the compression spring 111 is fitted into the lower spring seat portion 116 of the swing plate 103.

  A large impact component of the ground reaction force from the left and right front wheels 3 via the front axle case 13 is absorbed by the left and right compression springs 111, and is a repetitive vibration which is a relative displacement between the upper spring seat body 113 and the lower spring seat portion 116. Such a small impact component is attenuated by the left and right dampers 112 to ensure the riding comfort and running performance of the speed sprayer.

  The upper spring seat 113 of each suspension device 110 is configured to be capable of changing the position along the expansion / contraction direction (vertical direction) of the compression spring 111. A rear arm 118 extending rearward and a front arm 119 extending forward are attached to each upper spring seat 113 of the embodiment. A bifurcated pivot support bracket 120 is welded and fixed onto the third beam frame 102 above the arm portion 104 of the swing plate 103. A front end side (rear end side) of the rear arm 118 is rotatably connected to a pivot bracket 120 on the third beam frame 102 by a connection pin 121 that is laterally laterally oriented. Therefore, the position of the upper spring seat 113 can be changed along the expansion / contraction direction (vertical direction) of the compression spring 111 by the vertical rotation around the connecting pin 121.

  An electric cylinder 122 as an actuator is arranged between the front end side of the front arm 119 and the second beam frame 102 in front of the swing plate 103. The cylinder side end portion of the electric cylinder 122 is connected to the front end side of the front arm 119 by a horizontal axis pin 123 so as to be rotatable. A bifurcated support bracket 124 is welded and fixed onto the second beam frame 102. A rod side end portion of the electric cylinder 122 is rotatably connected to a support bracket 124 on the second beam frame 102 by a horizontal axis pin 125. The electric cylinder 122 is a so-called ball screw type, and the rod of the electric cylinder 122 moves forward and backward (the electric cylinder 122 expands and contracts) by rotating the electric motor 131 (see FIG. 12) described later forward and backward. It is composed.

  The upper spring seat 113 is rotated up and down around the connecting pin 121 by the expansion and contraction of the electric cylinder 122, and the position is changed along the expansion and contraction direction (vertical direction) of the compression spring 111. As a result, the initial spring length of the compression spring 111 and hence the biasing force are adjusted, and the vehicle height of the traveling machine body 1 is adjusted. In the embodiment, if the upper spring seat 113 rotates downward around the connection pin 121, the vehicle height of the traveling machine body 1 increases, and if the upper spring seat 113 rotates upward around the connection pin 121, the travel aircraft body. The vehicle height will be lower.

  A pair of left and right rolling restricting bodies 141 for restricting the rolling range around the left and right intermediate part of the front axle case 13 are provided on the lower surface side of the front part of the swing plate 103 so as to be distributed to the left and right. The rolling restriction body 141 is made of an elastic material such as rubber, and the left and right rolling restriction bodies 141 come into contact with the restriction brackets 142 attached to the inner surfaces of the left and right front frames 101, so The rolling motion around is limited. On the outer surface side of the left and right front frames 101, a swing restricting body 144 is provided via a mounting bracket 143 projecting leftward and rightward. Like the rolling restricting body 141, the swing restricting body 144 is made of an elastic material such as rubber, and the left and right swing restricting bodies 144 come into contact with the contact blocks 145 provided on the left and right sides of the front axle case 13. Further, the upward movement of the front axle case 13 (upward swinging with the rear end sides of both arms 104 of the swinging plate 103 as a fulcrum) is limited.

  Next, a configuration for executing the vehicle height adjustment control and a control mode thereof will be described with reference to FIGS. 12 and 13. As shown in FIG. 12, the traveling machine body 1 is equipped with a controller 130 as a control device that controls the overall operation of the speed sprayer. Although detailed illustration is omitted, the controller 130 includes a CPU for executing various arithmetic processes and controls, a ROM for storing control programs and data, a RAM for temporarily storing control programs and data, and It has an input / output interface.

  The controller 130 includes an injector 56 of the accumulator fuel injection device 55, a pressure sensor 62 for detecting the common rail internal pressure, a pressure control electromagnetic valve 63 for adjusting the fuel pumping amount to the common rail 57, and a rotational speed detection for detecting the engine rotational speed. An engine rotation sensor 66 serving as a detector, an accelerator sensor 67 for detecting the depression amount (operation amount) of the accelerator pedal 30, a throttle potentiometer 68 for detecting the operation position of the throttle lever 29, and an electric motor for moving the rod of each electric cylinder 122 forward and backward. 131, a motor driver 132 for driving, a rotation angle sensor 133 as an operation detector provided in each electric motor 131, a pump switch 134 for turning on / off the driving of the power spray pump 9, and a fan switch for turning on / off the driving of the blower fan 11 135 and chemical liquid tongue Chemical amount in 6 connects the chemical solution amount sensor 136 such as a detector for detecting (mountable amount).

  The rotation angle sensor 133 detects the rod protrusion amount of the electric cylinder 122 from the rotation angle of the motor shaft of the electric motor 131. The pump switch 134 and the fan switch 135 are arranged on the left side of the rear surface of the dashboard 23 in the cabin 5. The chemical amount sensor 136 is a float type sensor and is disposed in the chemical solution tank 6. In this case, based on the change in the vertical height position of the chemical liquid amount sensor 136, the chemical amount in the chemical liquid tank 6 and the machine load (sprung load) are detected.

  The controller 130 drives the pressure control electromagnetic valve 63 based on the detection result of the pressure sensor 62 so as to obtain an appropriate common rail internal pressure corresponding to the driving state of the engine 8, and appropriate injection corresponding to the driving state of the engine 8. Fuel injection control is performed to open and close each injector 56 so as to achieve the timing and the injection amount. In principle, when the traveling machine body 1 is in a stopped state, the controller 130 detects the fuel injection pressure and injection from each injector 56 so that the actual engine speed detected by the engine speed sensor 66 matches the idling speed set in advance. The timing and the injection amount (hereinafter referred to as a target injection pattern) are feedback-controlled. In a state other than the stop state, the controller 130 feedback-controls the target injection pattern so that the actual engine rotation speed matches the reference rotation speed corresponding to the operation position of the throttle lever 29 (detection result of the throttle potentiometer 68).

  Further, the controller 130 changes the position of the upper spring seat body 113 in conjunction with the change in the amount of the chemical solution, and keeps the vehicle height of the traveling machine body 1 constant regardless of the change in the amount of the chemical solution, that is, the body load (sprung load). Car height adjustment control is executed. The flowchart of FIG. 13 shows an example of vehicle height adjustment control. The algorithm (program) shown in the flowchart of FIG. 13 is stored in the ROM of the controller 130, and is executed by the CPU after the algorithm is called into the RAM. Note that the pair of electric motors 131 (the pair of electric cylinders 122) of the embodiment are configured to perform the same operation in synchronization with each other.

  In the vehicle height adjustment control, if both the pump switch 134 and the fan switch 135 are on (S01: YES), the power spray pump 9 and the fan switch 135 are driven and are in a chemical spraying state. The detection value 135 is read (S02), the electric motor 131 is rotated forward and backward according to the detection value of the chemical amount sensor 135, and the electric cylinder 122 is expanded and contracted, so that the vehicle height of the traveling machine body 1 is a predetermined value (for example, chemical amount). The position of the upper spring seat 113 is changed along the expansion / contraction direction (vertical direction) of the compression spring 111 (S03) so that the vehicle height is the same as the full vehicle height). Thereafter, the process returns to step S01.

  According to the above control, the position of the upper spring seat 113 can be changed in conjunction with the change in the amount of the chemical solution, and the vehicle height of the traveling machine body 1 can be kept constant regardless of the change in the chemical amount, that is, the body load (sprung load). it can. For this reason, it is possible to suppress the risk that the traveling machine body 1 comes into contact with the branches of trees during agricultural work (chemical solution spraying work) in an orchard or the like.

  As shown in another example of FIG. 14, a vehicle height adjustment switch 137 is connected to the controller 130, and the electric motor 131 is moved forward and backward according to the operation amount (pressing time, operation position, etc.) of the vehicle height adjustment switch 137. The position of the upper spring seat 113 may be changed by rotating the electric cylinder 122 to expand and contract. In this case, the vehicle height of the traveling machine body 1 can be adjusted as desired by the operator by manually operating the vehicle height adjustment switch 137. Accordingly, the vehicle height of the traveling machine body 1 (particularly the cabin 5) can be manually set to the minimum height during farming work (chemical solution spraying work) in an orchard or the like, and the risk of contact with tree branches or crops can be suppressed. Further, the suspension device 110 described above may be applied to the rear axle case 14. The detector is not limited to the chemical amount sensor 136 but may be a weight sensor such as a load cell that detects the weight of the chemical tank 6.

  As is apparent from the above description and FIGS. 10 and 11, the body frame 2 constituting the traveling body 1, the axle case 13 that supports the left and right wheels 3, and the axle case 13 is suspended from the body frame 2. In the agricultural vehicle including the suspension device 110, the suspension device 110 includes a compression spring 111 and a damper 112 that attenuate the ground reaction force from the two wheels 3, and a spring seat 113 that abuts on one end side of the compression spring 111. Since the spring seat body 113 is configured to be position-changeable along the expansion / contraction direction of the compression spring 111, the movement of the spring seat body 113 along the expansion / contraction direction of the compression spring 111 The initial spring length of the compression spring 111 and the urging force can be adjusted, and the vehicle height of the traveling machine body 1 can be adjusted in consideration of the machine load (sprung load). To become.

  Further, as is clear from the above description and FIGS. 10 to 13, the actuator 122 for moving the spring seat body 113 along the expansion / contraction direction of the compression spring 111, and the amount of the object mounted on the traveling machine body 1 are as follows. A detector 136 for detecting, and a control device 130 for driving the actuator 122 based on the detection information of the detector 136, wherein the spring seat body 113 is positioned according to the amount of the object mounted on the traveling machine body 1. Therefore, the position of the spring seat body 113 is changed in conjunction with the change in the amount of the mounted object, and the vehicle of the traveling machine body 1 regardless of the change in the amount of the mounted object, that is, the body load (sprung load). The height can be kept constant.

  The present invention is not limited to the above-described embodiment, and can be embodied in various forms. The configuration of each other part is not limited to the illustrated embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Traveling machine body 3 Front wheel 4 Rear wheel 6 Chemical solution tank 8 Engine 101 Front frame 102 Beam frame 103 Swing plate 109 Portal frame 110 Suspension device 111 Coil spring 112 Damper 113 Upper spring seat body 116 Lower spring seat part 118 Rear arm 119 Front arm 122 Electric cylinder 130 Controller 131 Electric motor 132 Motor driver 136 Chemical quantity sensor 137 Vehicle height adjustment switch

Claims (3)

In an agricultural vehicle comprising a machine frame that constitutes a traveling machine body, an axle case that supports left and right wheels, and a suspension device that suspends the axle case on the machine frame,
The suspension device includes a compression spring and a damper that damp ground reaction force from the both wheels, and a spring seat that abuts on one end side of the compression spring,
The spring seat is configured so that the position can be changed along the expansion and contraction direction of the compression spring.
Agricultural work vehicle. An actuator that moves the spring seat along the direction of expansion and contraction of the compression spring, a detector that detects the amount of an object mounted on the traveling machine body, and a control device that drives the actuator based on detection information of the detector And
The position of the spring seat body is changed according to the amount of the load mounted on the traveling machine body.
The agricultural work vehicle according to claim 1. The traveling aircraft is equipped with a chemical tank for storing chemical liquid, and the detector detects the amount of chemical liquid in the chemical tank.
The agricultural work vehicle according to claim 2.

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