Work vehicles

Abstract

There are work vehicles that regulate the vehicle speed and the output of the work motor regardless of the output command, for each predetermined threshold level depending on the remaining charge of the energy source in the battery. However, in the case of work vehicles that use an electric motor to drive a hydraulic pump that operates hydraulic equipment, if the battery runs out of charge and the motor stops, the hydraulic equipment cannot be operated and the vehicle cannot be stopped safely. Therefore, we provide a work vehicle that can be stopped safely when the remaining charge of the energy source is low. [Solution] In a work vehicle that is equipped with a working device and a hydraulic pump 16 driven by a work engine 12 on a traveling body that travels using drive wheels 2, 3 driven by a traveling engine 11, and has a storage section 5 that stores the energy sources of the traveling engine 11 and the work engine 12, when the remaining amount of energy falls below a predetermined threshold, the traveling engine 11 is first stopped while the work engine 12 continues to operate.

Description

[Technical Field]

[0001] The present invention relates to a work vehicle such as a lawn mower, a tractor, or a construction machine. [Background technology]

[0002] There is a work vehicle that regulates the vehicle speed and the output of the work motor at each threshold level that is predetermined according to the remaining amount of energy in the battery, regardless of an output command (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-142618 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the case of a work vehicle in which the hydraulic pump that operates the hydraulic equipment is driven by an electric motor, if the battery runs out of power and the motor stops, it is expected that the hydraulic equipment will no longer be able to operate and will not be able to be stopped safely.

[0005] In view of the above-mentioned problems, an object of the present invention is to provide a work vehicle that can be safely stopped when the remaining amount of an energy source becomes low. [Means for solving the problem]

[0006] The invention described in claim 1 is a work vehicle equipped with a working device 9 driven by a work motor 12 and a hydraulic pump 16 on a traveling body 4 that travels by drive wheels 2, 3 driven by a traveling motor 11, and provided with a storage section 5 that stores energy sources for the traveling motor 11 and the work motor 12, in which when the remaining amount of energy falls below a predetermined threshold, the traveling motor 11 is first stopped while the work motor 12 continues to operate.

[0007] According to the invention described in claim 1, the traveling motor 11 can be stopped to stop traveling while the working motor 12 is operating and the working device 9 and hydraulic pump 16 are operating, and the vehicle can be stopped safely.

[0008] The invention described in claim 2 is the work vehicle described in claim 1, which is provided with a vehicle speed detection means for detecting vehicle speed, and stops the work engine 12 after the vehicle speed detection means detects that the vehicle speed has reached 0.

[0009] According to the invention described in claim 2, the working motor 12 is stopped after the machine body has come to a complete stop, so that it can be stopped safely.

[0010] The invention described in claim 3 is a work vehicle described in claim 1 or claim 2, in which the acceleration of the rotational speed of the driving motor 11 is limited when the remaining amount of energy falls below a predetermined threshold value that is greater than the threshold value at which the driving motor 11 is stopped.

[0011] According to the invention described in claim 3, energy consumption is reduced and acceleration / deceleration is suppressed, allowing for safe stopping. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view of a riding lawnmower according to an embodiment of the present invention. [Figure 2] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] A riding lawnmower 1, which is an embodiment of a work vehicle disclosed in the present application, will be described in detail with reference to the accompanying drawings.

[0014] The forward / rearward direction is the direction in which the riding lawnmower 1 travels when traveling straight, with the front side of the traveling direction defined as "front" and the rear side defined as "rear." The traveling direction of the riding lawnmower 1 is the direction from the driver's seat 6, described below, toward the control device 7 when traveling straight.

[0015] The left-right direction is the direction that is horizontally perpendicular to the front-to-rear direction. In other words, when an operator of riding lawnmower 1 is seated in driver's seat 6 and facing forward, the left-hand side is the "left" side and the right-hand side is the "right" side.

[0016] The up-down direction is a direction parallel to the vertical direction. The front-rear direction, left-right direction, and up-down direction are perpendicular to one another. Note that each direction is defined for the convenience of explanation, and the present invention is not limited to these directions. In the following, the riding lawnmower 1 may also be referred to as the "machine body."

[0017] Furthermore, the present invention is not limited to the following embodiments.

[0018] As shown in Figure 1, riding lawnmower 1 is equipped with a battery 5, which serves as a storage unit for storing an energy source, at the bottom of a vehicle body 4 that moves using left and right front wheels 2, 2 and left and right rear wheels 3, 3, which are drive wheels, a driver's seat 6 and a control device 7 are installed on top, and a mower unit 9, which serves as a working device, is installed at the front of vehicle body 4 and can be raised and lowered freely using a link mechanism 8.

[0019] The mower unit 9 has a typical configuration, with a pair of blades on the left and right that rotate inside a box-shaped mower deck 9a with an open bottom, and the cut grass is sucked up by a blower 15 and transported to a collector C located at the upper rear of the machine body for storage.

[0020] As shown in Figure 2, the left and right front wheels 2, 2 and the left and right rear wheels 3, 3 are driven by a traveling motor 11 as a driving motor whose operation is controlled by a control device 10, and the mower unit 9 is driven by a PTO motor 12 as a work motor whose operation is controlled by the control device 10.

[0021] The PTO motor 12 drives the mower unit 9 via the work device drive PTO 13, drives the blower 15 via the blower drive PTO 14, and also drives a hydraulic pump 16 that sends pressurized oil to the lifting cylinder of the link mechanism 8 and the power steering of the control device 7.

[0022] A floor step 20 for the driver to board is provided in front of and below the driver's seat 6, and an operating device 7 is provided at the front end of the floor step 20 in front of the driver's seat 6.

[0023] The driving force of the travel motor 11 is transmitted to the left and right front wheels 2, 2 via a front wheel drive mechanism 22F equipped with a front wheel differential device 21F, and is transmitted to the left and right rear wheels 3, 3 via a rear wheel drive mechanism 22R equipped with a rear wheel differential device 21R.

[0024] The driving force of the PTO motor 12 is transmitted to the blower drive PTO 14 via a blower clutch 14a, and is transmitted to the implement drive PTO 13 via an implement clutch 13a.

[0025] The driving force is transmitted to the hydraulic pump 16 along the driving force transmission mechanism 23 from the PTO motor 12 to the working device clutch 13a.

[0026] The control device 10 controls a traveling motor 11 and a PTO motor 12 that operate on electric energy (power) supplied from a battery 5 that is a storage unit that stores an energy source.

[0027] That is, the control device 10 receives a signal from a remaining amount detection unit that detects the remaining amount of electric energy stored in the battery 5, and controls the traveling motor 11 and the PTO motor 12 according to the remaining amount as described below.

[0028] When sufficient electrical energy (power) is stored in the battery 5 (when electrical energy is stored at or above a predetermined first threshold), the control device 10 operates the travel motor 11 and PTO motor 12 with an output according to the operation of the control device 7 to move the machine and perform lawn mowing work.

[0029] When the remaining amount of electrical energy stored in the battery 5 is equal to or less than a predetermined first threshold, the control device 10 notifies the user through a notification means such as a meter panel, monitor, or voice notification that the remaining amount of electrical energy has fallen below the predetermined first threshold, and applies an output limit (reducing power consumption) to at least one of the power consumption, rotational torque, rotation speed, acceleration of the rotation speed, and current value of the traveling motor 11, thereby enabling the vehicle to move to an appropriate stopping location (a location where it can be stopped safely).

[0030] The power consumption, rotational torque, rotational speed, acceleration of rotational speed, and current value of the traveling motor 11 are detected by sensors provided in the traveling motor 11, respectively.

[0031] Therefore, when the remaining amount of electric energy stored in the battery 5 falls below a preset first threshold, the power consumption can be reduced, acceleration and deceleration can be suppressed, and the vehicle can move to an appropriate stopping place and stop safely.

[0032] Then, when the remaining amount of electrical energy stored in the battery 5 is equal to or less than a predetermined second threshold value, which is even less than the first threshold value, the control device 10 first stops the supply of electrical energy to the traveling motor 11 while leaving the PTO motor 12 operating, thereby stopping the traveling motor 11.

[0033] Therefore, the PTO motor 12 is left operating while the travel motor 11 is stopped, so travel can be stopped while the hydraulic pump 16 (working device) that sends pressurized oil to the lifting cylinder of the link mechanism 8 and the power steering of the steering device 7 is operating, allowing for safe stopping.

[0034] The traveling vehicle body 4 is equipped with a vehicle speed detection means consisting of rotation sensors provided in the front wheel drive mechanism 22F and the rear wheel drive mechanism 22R, and an inclination sensor that detects the left-right and front-to-back inclination of the vehicle body, and the control device 10 stops the PTO motor 12 by cutting off the supply of electrical energy to the PTO motor 12 after detecting that the vehicle speed has reached 0 using the vehicle speed detection means (after detecting that the vehicle has stopped).

[0035] Therefore, the PTO motor 12 is stopped after the aircraft has come to a complete stop, allowing the aircraft to be stopped safely.

[0036] Furthermore, if the vehicle stops on a slope and is in an inclined state, there is a danger that the vehicle may start moving again on the slope. Therefore, when the inclination sensor detects an inclination of the vehicle at a predetermined angle or more, the determination that the vehicle has stopped as detected by the vehicle speed detection means is suspended (invalidated), and it is safer to control the PTO motor 12 to stop after the vehicle has moved to flat ground where the inclination sensor detects an angle less than the predetermined angle and stopped.

[0037] The vehicle speed detection means may be a means for detecting the vehicle speed by continuously calculating the vehicle position by GNSS using a GNSS receiver provided on the traveling vehicle body 4, or any other vehicle speed detection means.

[0038] In the above, an example of a battery 5 is shown as a storage unit that stores electrical energy as an energy source, but a fuel tank that stores diesel, gasoline, etc. as an energy source may also be used, in which case a diesel engine or a gasoline engine is used as the driving motor and the working motor.

[0039] The driving motor and the working motor may be any other motor, and the storage unit stores an energy source suited to the motor used.

[0040] Furthermore, although a riding lawnmower has been shown as an example of a work vehicle in the above, any other work vehicle such as a tractor or earthmoving machine may also be used. [Explanation of symbols]

[0041] 2 Drive wheels (front wheels) 3 Drive wheels (rear wheels) 4 Running vehicle 5. Storage unit (battery) 9 Working equipment (mower unit) 11. Driving motor (driving motor) 12. Power take-off motor 16 Hydraulic pump

Claims

1. A work vehicle equipped with a working device (9) driven by a work motor (12) and a hydraulic pump (16) on a traveling body (4) that travels by drive wheels (2, 3) driven by a traveling motor (11), and provided with a storage section (5) that stores energy sources for the traveling motor (11) and the work motor (12), characterized in that when the remaining amount of energy falls below a predetermined threshold, the traveling motor (11) is first stopped while the work motor (12) remains operating.

2. 2. The work vehicle according to claim 1, further comprising a vehicle speed detection means for detecting the vehicle speed, and the work engine (12) is stopped after the vehicle speed detection means detects that the vehicle speed has reached zero.

3. 3. The work vehicle according to claim 1, wherein when the remaining amount of energy falls below a predetermined threshold value that is greater than the threshold value at which the driving motor (11) is stopped, the acceleration of the rotational speed of the driving motor (11) is limited.

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