JP2013032039A - Motorized tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a motorized tractor with high energy recovery efficiency by accurately grasping a work mode and the like.SOLUTION: A tiller 41 is attached to a tractor body to be able to elevate to a machine body 1. A rear wheel motor 10, which is connected with a battery and performs a driving output to a rear wheel output shaft 12, and a front wheel motor 11, which performs a driving output to a front wheel output shaft 25, are respectively provided. The front wheel motor 11 is configured to be switched to a power generating mode by receiving a power generation output from the front wheel output shaft 25 side. A power charger is connected with a circuit of the front wheel motor 11 and generates power to charge the battery by receiving the power generation output from the front wheel output shaft 25 side. A brake action is applied to front wheels 2 by a power generating action to prevent so called dashing which is caused by a rotation of rotary claws of the tiller 41.

Description

  The present invention relates to an electric tractor including a battery and an electric motor as power sources.

A configuration including a traveling electric motor that drives a traveling wheel and a PTO electric motor that drives a work machine driving PTO shaft is known (Patent Document 1). In Patent Document 1, when an operation is performed by running the machine body, the electric motor for traveling and the electric motor for PTO are driven, the PTO shaft is rotated by the electric motor for PTO, and the rear and front wheels are driven by the electric motor for traveling. To drive the aircraft. By the way, the cited document 1 is a configuration in which the PTO system power is joined to the power transmission system from the traveling system electric motor to the wheels, and therefore, when the traveling load increases and the forward speed of the vehicle body decreases, the PTO electric motor is reduced. A part of the power of the vehicle can be joined to the traveling system to compensate for the shortage of the traveling torque, and efficient power transmission according to the work contents and soil condition of the field is made possible.
JP 2002-356116 A

However, when a tillage work machine is attached to the rear part of the machine, when the tillage shaft is rotated by the driving force that drives the work machine, the rotational force generated when the tillage claws plows the soil advances the machine. A pushing force is generated on the side, and the traveling wheel is in a brake state against this pushing force. Therefore, if it is configured to compensate for the shortage of running torque based on the configuration of cited document 1, it tends to be inefficient.

  In view of the above, the present invention intends to realize an electric tractor having a high energy recovery effect by accurately grasping a working state and the like.

In view of the above problems, the present invention has taken the following technical means.
That is, according to the first aspect of the present invention, the tilling work machine 41 is mounted on the machine body 1 having the front and rear wheels 2 and 5 so as to be movable up and down, and the machine body 1 is provided with the batteries 45 and 65. Are provided with a rear wheel motor 10 for driving output to the rear wheel output shaft 12 and a front wheel motor 11 for driving output to the front wheel output shaft 25, respectively. The front wheel motor 11 receives the power generation output from the front wheel output shaft 25 side. Thus, the electric tractor is configured to be switched to the power generation state.
According to the second aspect of the present invention, the charger 49 is connected to the circuit of the front wheel motor 11 so as to receive the power generation output from the front wheel output shaft 25 side and generate power to charge the batteries 45 and 65. The electric tractor according to claim 1.
In this way, the rear wheel motor 10 is started and the tilling work machine 41, which is driven to rotate appropriately, is lowered and grounded to the working posture. At this time, by setting the front wheel motor 11 in the non-driven state, the front wheel 2 rotates by grounding, and the front wheel motor 11 placed in the non-driven state is switched to the generator. This power generation action applies a braking action to the front wheels 2 to prevent so-called dashing due to the rotation of the rotary claws of the tillage work machine 41. The batteries 45 and 65 are charged via the charger 49 by the power generation action of the front wheel motor 11.
According to a third aspect of the present invention, the front wheel motor 11 having a power generation function activates the front wheel output shaft 25 by power supply based on an ascending command signal to the lifting mechanism 38 that puts the tillage working machine 41 in a non-working state. 3. The switching means for switching to a power generation state by a power generation output from the front wheel output shaft 25 side on the basis of a lowering command signal for setting the motor state and conversely setting the tillage work machine 41 to the working state. Electric tractor.
With this configuration, the motor state and the power generation state are automatically switched. In a working state in which dashing is likely to occur, the front wheel 2 is brought into a brake state as a power generation state.
According to a fourth aspect of the present invention, there is provided current detection means 61 for detecting the motor current of the front wheel motor 11 having a power generation function, and the front wheel motor 11 is switched from the motor state to the power generation state based on the current detection result. The electric tractor according to claim 1 or claim 2 configured.
When it is determined by the current detection means 61 that the load current of the front wheels decreases below a predetermined level due to the dashing phenomenon, the front wheel motor 11 automatically switches from the motor state to the power generation state.
The invention according to claim 5 is the electric tractor according to any one of claims 1 to 4, wherein the rear-wheel motor 10 drives the rear-mounted work machine transmission shaft 17. If comprised in this way, a working machine will be driven with a rear-wheel drive, and a motor can be combined.

Since the present invention is configured as described above, the following effects can be obtained.
That is, according to the first and second aspects of the invention, when the tillage work machine 41 is started, the front wheel motor 11 is set in a non-driven state, so that the front wheel 2 rotates by grounding and is brought into a non-driven state. The front wheel motor 11 is in a power generation state, applies a braking action to the front wheel 2, and can prevent so-called dashing due to rotation of the rotary claws of the tillage work machine 41. Further, the battery 45 can be charged via the charger 49 by the power generation action of the front wheel motor 11.
In addition to the effects described in claims 1 and 2, the invention described in claims 3 and 4 can automatically switch between the motor state and the power generation state, thereby reducing the operation burden on the operator.

  According to the fifth aspect of the present invention, in addition to the effects of the first to third aspects, the work machine is driven together with the rear wheel drive, so that the motor can also be used.

Overall side view of tractor Overall view of the tractor Transmission diagram Control block diagram Control block diagram Side view (A) showing the battery mounted state, developed perspective view (B), hitch member perspective view (C) Side view showing the battery installed flowchart flowchart flowchart flowchart flowchart flowchart flowchart flowchart flowchart

Embodiments of the present invention will be described below with reference to the drawings.
A side view of the electric tractor of the present embodiment is shown in FIG. 1, and a plan view thereof is shown in FIG.
A front axle 3 having a pair of left and right front wheels 2 on the lower front side of the body 1 is swingably supported around the center pivot 4 and a rear axle case 6 having a pair of left and right rear wheels 5 is mounted on the lower side of the rear part. 1 configuration A part of the transmission case 7 is supported on the left and right respectively.
A rear wheel motor 10 and a front wheel motor 11 are provided in the transmission case 7 and the hood 8, respectively.
The pinion gear 13 of the output shaft 12 of the rear wheel motor 10 interlocks with the ring gear of the rear wheel differential mechanism 14, and the transmission is branched from the middle of the output shaft 12 via the intermediate gear group 15 to drive the PTO transmission shaft 17. It is. Further, the hydraulic pump 18 is driven via the intermediate gear 15.
A rear axle 19 is extended from the rear wheel differential mechanism 14 to the left and right, and the differential output is configured to interlock with the rear wheel shaft 22 via a brake mechanism 20 and a reduction gear mechanism 21.
Further, the pinion gear 26 of the output shaft 25 of the front wheel motor 11 is configured to drive the ring gear 28 of the front wheel differential mechanism 27. Further, the left and right front axles 29 supported in the front axle 3 are configured to be differentially driven. A vertical transmission shaft 31 is provided at a final speed reduction portion between the front axle 28 and the front wheel shaft 30 so that the front wheel 2 can be steered.
A three-point link mechanism 37 comprising a pair of lower links 35 and a single top link 36 is provided at the rear part of the transmission case 7 constituting the airframe 1 and can be moved up and down by a hydraulic lifting cylinder mechanism 38 as a lifting mechanism. It is composed. That is, the lift arm 39 of the hydraulic lift cylinder mechanism 38 and the lower link 35 are connected by a lift rod 40, and the lift arm 39 is rotated by supply and discharge of pressure oil to and from the lift cylinder. 37 moves up and down the rear side. Note that the hydraulic oil to the lifting cylinder can be supplied or discharged by the hydraulic pump 18 based on switching of a non-illustrated valve by reciprocating the operation of the lifting lever 32 in the vicinity of the operation seat 31. It is configured.
A tilling work machine 41 is attached to the rear of the three-point link mechanism 37. The working machine 41 is provided with a tilling shaft 43 provided with a rotary tilling claw 42 and various covers, and the tilling claw 42 is a known configuration that is driven into the soil by rotation and tilled. The tilling shaft 43 rotates in the direction of arrow D in the figure, and the tilling claw 42 is driven from the front side of the tilling work machine 41 and acts to jump up the tilling soil from the rear.
The rear end of the PTO transmission shaft 17 extends to the rear portion of the transmission case 7 to form a PTO take-out shaft portion 17a, and the tilling work machine 41 can be driven via the universal joint shaft.
In the block diagram of FIG. 4 or FIG. 5, the rear wheel motor 10 and the front wheel motor 11 are both electrically connected to the batteries 45 and 65 and are supplied with electric power to receive the rear wheel inverter 46 and the front wheel inverter 47. The rear wheel 5 and the front wheel 2 can be driven by rotating at the set rotation speeds Nf and Nr. The change input to the rear-wheel inverter 46 and the front-wheel inverter 47 is based on the detected depression amount output of the accelerator pedal 51, the fuselage forward / reverse switching output of the forward / reverse lever 52, the operation output of the start / stop switch 53, and the like.
By the way, the front wheel motor 11 is a power generation function type electric motor that also has a function as a generator that generates and outputs power by driving from the output shaft 25 side, and the rotation of the front wheel 2 is transmitted through the front axle 29 to the front wheel motor. 11 to generate power based on the power generation principle. Specifically, a changeover switch means 48 (switching means) is provided between the front wheel motor 11 and the battery 45, one of which is selectively connected to the front wheel inverter 47 and the other is selectively connected to the charger 49. The changeover means 48 may be switched to these by automatic control as described later, as well as by a manual switching lever (not shown).
The battery controller 50 interposed in the circuit controls the power supply from the batteries 45 and 65 or controls the charging output to the batteries 45 and 65.
Next, a configuration for mounting the battery 45 on the fuselage will be described. Compared to a conventional agricultural tractor, an engine is not required, and various transmission mechanisms are not required in the transmission case 7, so the battery 45 may be mounted using the relevant part. However, since it is heavy, it may be configured as follows. That is, the parallel link mechanism 55 is mounted on the front or rear (front in the illustrated example) of the machine body 1, and the hitch member 56 is configured on the parallel link mechanism 55 to mount the battery 45. Specifically, the parallel link mechanism 55 is mounted on the front portion of the machine body 1 so as to be rotatable up and down, and the front hitch member 56 can be moved up and down in parallel by the expansion and contraction operation of the electric expansion and contraction cylinder 57. The hitch member 56 is formed with a mountain-shaped convex portion 56v that can engage with a mountain-shaped concave portion 45c formed on one side of the battery 45, engages both, and restricts the forward / backward movement by the hook-shaped locking means 58. 45 is mounted on the body 1.
With this configuration, the heavy battery 45 is placed on the ground, the parallel link mechanism 55 is lowered, and the mountain-shaped convex portion 56v of the hitch member 56 enters and engages the mountain-shaped concave portion 45c of the battery 45 from below, The parallel link mechanism 55 and the hitch member 56 are raised to maintain the battery 45 at a predetermined height. In this case, since the parallel link mechanism 55 is used to move up and down in parallel, the horizontal posture can be maintained, and even if the battery 45 is in the form of encapsulating the electrolyte solution like a lead storage battery, the airframe 1 does not bias the electrolyte solution. Can be attached to. Note that when the parallel link mechanism 55 is mounted on the body 1 side, the parallel link mechanism 55 can be adjusted to rotate about the longitudinal direction of the body. This is more effective because the level can always be maintained by correcting.
As shown in FIG. 6, the second battery 45X, the third battery 45Y,... Have a chevron convex portion 56v of the hitch member 56 on the front and rear surfaces, and a chevron concave portion 45c corresponding to the chevron concave portion 45c of the battery 45. A mountain-shaped convex portion 45v that engages with this is configured, and the number of 45 batteries can be continuously mounted. Note that the battery terminals 45X, 45Y,..., Which are provided with electrode terminals between the chevron-shaped concave portions and the chevron-shaped convex portions and are sequentially connected, have a so-called parallel connection configuration with respect to the first battery 45.
7 is configured such that the generator 58 can be mounted in the batteries 45, 45X, and 45Y that are mounted in a stacked state. The generator 58 includes a small engine in a frame formed in a box and incorporates a power generation circuit, and an output terminal is formed with a mountain-shaped recess 58c in the same manner as the batteries 45X, 45Y. Yes. For this reason, it is provided in a relationship of engaging with the mountain-shaped convex portion 45 v formed in the battery 45, and can be attached to the machine body 1. For this reason, it can charge easily by driving the generator 58 during a work. Further, the battery 45 can be removed from the machine body 1 with a pair of batteries 45 and charged at an appropriate place.
Tillage work is performed with the electric tractor configured as described above. When the start / stop switch 53 is operated to the “start” side and the lifting / lowering lever 32 is operated to the lowering side in the field while rotating each part of the body 1, the tilling work machine 41 in the non-working posture is grounded to the field scene. The grounding operation of the rotary tilling claw 42 continues by this contact, and the tilling work machine 41 tries to do the dashing, and the action work force makes the sowing work machine 41 soaked from the rear even if trying to work at a predetermined rotational speed. The operator tries to do the dashing, and the operator responds by fine adjustment of the elevating lever 32. At the start of the tilling work, the front wheel motor 11 is driven from the front wheel 2 side by selectively connecting the changeover switch means 48 to the charger 49. The power generation state is reached and the power generation output is applied to the charging of the battery 45. In this case, not only the driving force is not transmitted to the front wheels 2, but also the front wheel motor 11 is rotationally driven by tracing back the transmission path to the front wheels 2, so that the braking action is applied to the front wheels 2 and Dashing can be prevented and desired tilling work can be carried out (Fig. 8).
When the end of the field is reached and the turning operation is started, the changeover switch means 48 is switched to the front wheel inverter 47. Along with this, the front wheel 2 is driven by the power supply from the battery 45 side to the front wheel motor 11. Therefore, driving the front wheels can contribute to a small turn. When restarting the tilling work after the turn, the changeover switch means 48 is again switched to the charger 49 side (FIG. 8).
If comprised as mentioned above, dashing can be prevented and there exists an effect which can collect | recover unnecessary energy.
In the above-described embodiment, the changeover switch means 48 is switched manually. However, a configuration in which it is automatically performed as follows may be used. That is, it is based on the raising or lowering operation of the lifting lever 32. The moving range of the elevating lever 32 is provided with an ascending side detection sensor and a descending side detection sensor. Based on these detection results, it is determined whether the tilling work machine 41 is raised or lowered, and the front wheel motor 11 is connected. It is the structure which switches automatically to the charger 49 side or the inverter 47 for front wheels (FIG. 9 (switching switch automatic selection 1)). By doing so, the selector switch is automatically selected based on a work implement lifting operation essential during turning, thereby reducing the burden on the operator. It should be noted that the construction machine can be determined to be lifted based on the detection of the lifting lever 32 from the position of the descending side detection sensor by the rising side detection sensor, and in the opposite case, the construction machine can be judged to descend.
The lift arm 39 of the lift cylinder mechanism 38 is provided with a potentiometer type detector 60 for detecting the arm angle, and the lift command signal is output to the lift cylinder mechanism 38 as the lift means of the tillage work machine 41 to detect the detection. When the detection angle θ of the riff and arm 39 is detected to rise to the non-working position of the tilling work machine 41 by the device 60, that is, exceeds the predetermined angle α set in advance, the changeover switch means 48 is supplied with power to drive motor. When the lowering of the tilling work machine 41 to the working position is detected, the output shaft 25 side via the front wheel 2 and the front axle 29 is detected. Is configured to switch to a power generation state in response to the power generation output from (FIG. 10 (switching switch automatic selection 2)). With this configuration, the load can be reduced because the operator can automatically select without being aware of the same as described above.
Furthermore, it can also be configured as follows. A current detector 61 for detecting the current value I of the front wheel motor is provided. Based on whether or not the detected current value I exceeds a preset current value Is, for example, the load on the front wheel 2 becomes lighter and the current value When I becomes equal to or less than the set current value Is, it is determined that dashing is caused, and switching to the charger 49 side (FIG. 11 (switching switch automatic selection 3)). Alternatively, it is determined whether or not the dashing is performed based on whether the ratio of the detected current value If of the front wheel motor 11 to the detected current value Ir of the rear wheel motor 10 is equal to or less than a preset value β. Switch to 49 side (FIG. 12 (selection switch automatic selection 4)). In either case, the motor current is monitored to determine whether the front wheel motor 11 is in a motor state in which power is supplied to drive the output shaft, or whether the front wheel motor 11 is in a power generation state in which the driving force is received from the front wheel 2 side. It can be switched automatically, reducing the operational burden on the operator.
Next, a description will be given of control of discharging and the like in a configuration in which a plurality of batteries 45, 45X, 45Y. As shown in FIG. 13, a built-in battery 65 is provided in the hood 8 of the tractor body 1 with respect to the external battery 45 that can be attached to and detached from the exterior of the tractor body 1. Hereinafter, the built-in battery 65 is referred to as a first battery 65, and the external battery 45 is referred to as a second battery 45. As shown in the block diagram (FIG. 5), the first and second batteries 65 and 45, the front and rear wheel inverters 46 and 47, the charger 49, and the battery controller 50 are connected. First, when the external second battery 45 is mounted, the internal first battery 65 can be charged from the replaceable second battery 45 for external attachment. By configuring the built-in type first battery 65, which is not easy to replace, from the replaceable second battery 45, the built-in type second battery 65 can be always fully charged, and workability can be improved. .
Regarding the discharge control of the first and second batteries 45 and 65, the battery controller 50 controls the order of power supply to the front and rear wheel motors 10 and 11 for the connected batteries 45 and 65. That is, priority is given to the use (discharge consumption) of the second battery 45, and the battery controller 50 controls the order so that the power supply from the first battery is received when the discharge of the second battery 45 is completed. As a result, by using the replaceable battery 45, it is possible to clarify the charging timing of the externally attached first battery in view of the usage status of the built-in second battery 65.
The following examples provide safety when performing operations from forward to reverse or vice versa. Even if the forward / reverse lever 52 is present, the front wheel motor 11 and the rear wheel motor 10 are not immediately switched in accordance with this, but the depression amount detection sensor 66 of the accelerator pedal 51 and the forward / reverse position detection switch 67f of the forward / reverse lever 52 are detected. , 67r, etc., the motor is properly switched between forward rotation and reverse rotation when certain conditions are met. As shown in FIG. 13, when the forward / reverse lever 52 is operated, the forward / backward advance detection sensor 66 of the accelerator pedal 51 is almost zero, that is, the operator releases the accelerator pedal 51. The forward motor 11 and the reverse motor 10 are switched in the direction set by the lever 52 (forward / reverse switching control 1). Therefore, there is no fear of starting in the reverse direction immediately after the operation of the forward / reverse lever 52, which is safe. Further, in the example of FIG. 14, a vehicle speed sensor 68 is provided, and safety is ensured as a configuration in which the vehicle does not start in the direction set by the forward / reverse lever 52 unless the detected vehicle speed becomes a predetermined low speed Vm or less (forward / reverse switching control 2). In these examples, the power generation state of the front wheel motor 11 is not necessarily required.
FIG. 15 shows the front wheel / rear wheel ratio control during turning, and the turning operation is performed by operating the handle 70. At this time, the turning angle is detected by the front wheel turning angle detecting means 71, and the motor rotation corresponding to the turning angle is performed. Thus, the rotation correction output is output to the front and rear wheel inverters 46 and 47 so that the vehicle is turned at a predetermined front wheel / rear wheel rotation ratio for each turning angle. If comprised in this way, turning operation | movement can be performed with a small turning radius.
Further, FIG. 16 shows front brake speed increase control during single brake, and when a so-called single brake operation is performed based on the detection results of the left / right brake detection switches 72L and 72R, a speed increase command signal is sent to the front wheel inverter 47. It is the structure which outputs. The one-brake operation is used when making a small turn. However, the center of rotation of the airframe 1 is the rear wheel axis, and the rotation radii of the front and rear wheels are different. However, a small turn can be easily performed by increasing the speed of the front wheels as described above. The power generation state of the front wheel motor 11 is not necessarily required in the examples of FIGS.

1 Airframe 2 Front wheel 5 Rear wheel 10 Rear wheel motor 11 Front wheel motor 12 Output shaft (rear wheel output shaft)
25 Output shaft (front wheel output shaft)
38 Elevating cylinder mechanism (elevating mechanism)
41 Tillage working machine 45 Battery 48 Changeover switch means (switching means)
49 Battery charger 61 Current detection means 65 Battery

Claims (5)

A tilling work machine (41) is mounted on a machine body (1) having front and rear wheels (2, 5) so as to be movable up and down, and the machine body (1) is provided with a battery (45, 65). A front wheel motor (10) connected to (45, 65) for driving output to the rear wheel output shaft (12) and a front wheel motor (11) for driving output to the front wheel output shaft (25). An electric tractor configured such that (11) receives a power generation output from the front wheel output shaft (25) side and switches to a power generation state. A battery charger (49) is connected to the circuit of the front wheel motor (11) to receive power generation output from the front wheel output shaft (25) side to generate power and charge the battery (45, 65). The electric tractor according to Item 1. The front wheel motor (11) having a power generation function is a motor that activates the front wheel output shaft (25) by power supply based on an ascending command signal to a lifting mechanism (38) that puts the tilling work machine (41) into a non-working state. The switching means (48) configured to switch to a power generation state based on a power generation output from the front wheel output shaft (25) side based on a lowering command signal that sets the state to a tilling work machine (41) in a working state. Item 3. The electric tractor according to Item 2. A current detection means (61) for detecting the motor current of the front wheel motor (11) having a power generation function is provided, and the front wheel motor (11) is switched from the motor state to the power generation state based on the current detection result. The electric tractor according to claim 1 or 2. The electric tractor according to any one of claims 1 to 4, wherein the rear wheel motor (10) drives the rear-mounted work machine transmission shaft (17).

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