State amount display system and work vehicle

Abstract

To provide a state amount display system in which a driver can understand a state amount having high urgency even when it is mounted on a work vehicle that cannot secure only a narrow display space.SOLUTION: A state amount display system that displays a state amount in a work vehicle comprises: a detection value input unit 51 that inputs the detection value of the state amount in a plurality of kinds of component; a limit value management unit 72 that manages a limit value associated with each of state amounts; an urgency degree calculation unit that calculates a notification urgency degree which is normalized from a corresponding detection value and a corresponding limit value for each state amount; and a display control unit 74 that selects a detection value corresponding to a state amount having a maximum notification urgency degree to display on a state amount display unit 80.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a state quantity display system for displaying state quantities in a work vehicle, and a work vehicle equipped with this state quantity display system.

Background Art

[0002] As a display device for displaying state quantities in a work vehicle, such as coolant water temperature, electrical equipment temperature, hydraulic equipment temperature, engine rotation speed, remaining fuel, etc., a meter panel composed of a liquid crystal, a 7-segment display, etc. is known.

[0003] The liquid crystal display constituting the display device disclosed in Patent Document 1 includes a vehicle speed display unit for displaying vehicle speed, a shift display unit for displaying the operation position of the shift lever, an integrated display unit for displaying the integrated travel distance or the integrated engine operation time, a rotation speed display unit for displaying the engine rotation speed, a temperature display unit for displaying the temperature of the engine coolant water, and a remaining quantity display unit for displaying the remaining quantity of fuel. The vehicle speed display unit has a two-digit display part in 7-segment display. The shift display unit has a one-digit display part in 14-segment display. The integrated display unit has a six-digit display part in 7-segment display. The rotation speed display unit has a four-digit display part in 7-segment display. The temperature display unit has a 7-segment display part for bar graph display. The remaining quantity display unit has a 7-segment display part for bar graph display.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The display device disclosed in Patent Document 1 can display many types of state quantities in a work vehicle. However, the area required for these displays becomes large, and it is not suitable for a small work vehicle or the like that can only secure a narrow display space.

[0006] Therefore, there is a demand for a state quantity display system that allows a driver to grasp state quantities with high urgency even when mounted on a work vehicle that can only secure a narrow display space.

Means for Solving the Problem

[0007] A state quantity display system for displaying state quantities in a work vehicle according to the present invention includes a detection value input unit that inputs detection values of the state quantities in a plurality of types of components, a limit value management unit that manages limit values associated with each of the state quantities, an emergency degree calculation unit that calculates a notification emergency degree normalized from the corresponding detection value and the corresponding limit value for each state quantity, and a display control unit that selects the detection value corresponding to the state quantity having the maximum notification emergency degree and displays it on a state quantity display unit.

[0008] According to this configuration, a notification emergency degree representing the importance to be notified to the driver is calculated from the detection values of a plurality of types of state quantities and the limit values associated with each state quantity, and the detection value of the state quantity with the highest notification emergency degree is displayed on the state quantity display unit. That is, the detection value of the state quantity with the highest notification emergency degree is displayed on the state quantity display unit, and the detection values of state quantities with low notification emergency degrees are not displayed. Therefore, not only is it possible to have a small display space for the state quantity display unit, but also the advantage that the burden on the driver for checking the display is small because the detection values of state quantities with low notification emergency degrees are not displayed. Also, even when the relationship between the detection value and the limit value of the state quantity varies depending on the type of state quantity, by normalizing, the calculated emergency degree is substantially made common, so it can be easily grasped.

[0009] Regarding the state quantities related to the machine temperature and machine operation (such as speed), generally, they are checked by dividing them into a caution level that generally does not lead to the stoppage of the work vehicle and a warning level that leads to the stoppage of the work vehicle. These caution levels and warning levels also vary depending on the type of state quantity. Therefore, when calculating the notification urgency, it is preferable to consider the caution level and warning level set for each state quantity. Therefore, in the present invention, the limit value management unit manages, as the limit values, a first limit value that causes a functional limitation of the corresponding component and a second limit value that causes the stoppage of the component for each state quantity, and the urgency calculation unit calculates the notification urgency for each state quantity by a function that uses the detected value as a variable and the first limit value and the second limit value as constants.

[0010] When the detected value of the state quantity is displayed on the state quantity display unit, if the relationship between the first limit value (for example, the caution level) and the second limit value (for example, the warning level) of the state quantity is known, it becomes easy to predict the events that may occur next, which is convenient. Therefore, in the present invention, the display control unit displays the state quantity with the maximum notification urgency on the state quantity display unit in a graph form in which the relationship between the detected value and the first limit value and the relationship between the detected value and the second limit value can be read.

[0011] When state quantities such as temperature and speed are displayed on a gauge chart, it becomes easy to read (grasp) the current state quantity. Furthermore, since the gauge chart is composed of sections in which the area for displaying values is divided into a plurality of parts, it becomes easy to incorporate the areas corresponding to the first limit value and the second limit value, which are specific values, into the area for displaying values. Therefore, in the present invention, the graph form is a gauge chart, and the chart is color-coded into a first area up to the first limit value and a second area from the first limit value to the second limit value.

[0012] In a work vehicle, particularly an electric work vehicle, the state quantities that need to be paid special attention to by the driver are the temperature of the battery, the temperature of the motor, the temperature of the inverter, the temperature of the cooler, and the temperature of the hydraulic equipment. Therefore, in the present invention, the components include at least two of the battery, the motor, the inverter, the cooler, and the hydraulic equipment, and the state quantity is the temperature of the components.

[0013] The subject matter of the present invention includes not only the state quantity display system described above, but also a work vehicle equipped with such a state quantity display system.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0015] In this specification, unless otherwise specified, "front" means the front in the longitudinal direction (travel direction) of the vehicle body, "rear" means the rear in the longitudinal direction (travel direction) of the vehicle body. Also, the left-right direction or the lateral direction means the transverse direction (vehicle body width direction) of the vehicle body perpendicular to the longitudinal direction of the vehicle body. "Up" or "down" is the positional relationship in the vertical direction of the vehicle body, indicating the relationship at the ground height. In the drawings, "front" is indicated by "F", "rear" by "B", "left" by "L", "right" by "R", "up" by "U", and "down" by "D".

[0016] Next, one embodiment of the work vehicle according to the present invention will be described. Here, the work vehicle is an electric lawn mower (hereinafter simply referred to as the work vehicle). As shown in FIGS. 1 and 2, this work vehicle includes a pair of left and right front wheels 11 supported at the front of the vehicle body 1, a pair of left and right rear wheels 12 as drive wheel units supported at the rear of the vehicle body 1, and a lawn mowing device 3 as a work device supported between the front wheels 11 and the rear wheels 12 below the vehicle body 1. A device storage portion 60 for storing a battery 6 and the like is provided between the left and right rear wheels 12. Further, a driver's seat 13, a roll-over protective structure (ROPS) frame 14, and the like are provided on the vehicle body 1.

[0017] The vehicle body 1 includes a frame 10 composed of left and right longitudinal beams extending in the front-rear direction and cross beams connecting the longitudinal beams. The lower end of the ROPS frame 14 is connected to the frame 10.

[0018] The front wheels 11 are caster-type wheels, and the rear wheels 12 are drive wheels. Inside each of the rear wheels 12, a left traveling motor 41 and a right traveling motor 42 are arranged as traveling electric motors. The power of the left traveling motor 41 and the right traveling motor 42 is transmitted to the rear wheels 12 via a speed reduction mechanism 16. Each rear wheel 12 is independently driven.

[0019] As shown in FIG. 2, fenders 8 are arranged on the right side and the left side of the driver's seat 13. On both sides of the driver's seat 13, a left shift lever 17a and a right shift lever 17b are arranged as vehicle speed setting tools for setting a desired vehicle speed. When the right shift lever 17b is operated to the neutral position, the right traveling motor 42 stops. When the right shift lever 17b is operated to the forward side, the right traveling motor 42 rotates to the forward side, and when the right shift lever 17b is operated to the reverse side, the right traveling motor 42 rotates to the reverse side. Similarly, when the left shift lever 17a is operated to the neutral position, the forward side, and the reverse side, the left traveling motor 41 performs the same operations as the right traveling motor 42 described above. That is, by operating the right shift lever 17b and the left shift lever 17a, the right and left rear wheels 12 are independently driven to the forward side or the reverse side, and the vehicle body 1 moves forward or backward, turns right or turns left.

[0020] As shown in Fig. 1, a lawn mowing device 3, which is an example of a working device, includes a mower deck 30 and a mowing blade 31 rotatably supported around a vertical axis inside the mower deck 30. The mowing blade 31 is a rotary blade and is rotationally driven by a mower motor 43 which is a working electric motor. The mower deck 30 is suspended from the frame 10 by a link mechanism 34 so as to be vertically movable.

[0021] Fig. 3 shows the power system and control system of the work vehicle. The mower motor 43 is provided on the rear wall of the mower deck 30. The mower motor 43 rotates a rotary shaft 32 to which the mowing blade 31 is attached via a belt transmission mechanism 33. A left traveling motor 41 is provided to rotate the left rear wheel 12, and a right traveling motor 42 is provided to rotate the right rear wheel 12.

[0022] Power is supplied from an inverter 4 to the left traveling motor 41, the right traveling motor 42, and the mower motor 43. The inverter 4 includes a traveling motor inverter 4A that supplies power to the left traveling motor 41 and the right traveling motor 42, and a mower motor inverter 4B that supplies power to the mower motor 43. The inverter 4 is driven and controlled based on a control signal from a control unit 5. The inverter 4 is connected to a battery 6 as a power source. Note that the traveling motor inverter 4A includes an inverter for the left traveling motor 41 and an inverter for the right traveling motor 42.

[0023] An equipment storage unit 60 that houses the inverter 4, the control unit 5, the battery 6, etc. is provided with a cooler including a cooling fan 18 for cooling the stored equipment.

[0024] As shown in FIG. 4, the fender 8 is provided with an operation panel 8A and a display panel 8B. On the display panel 8B, various notification lamps and a liquid crystal display 80 are arranged, and on the left and right sides of the liquid crystal display 80, a group of notification lamps for notifying various vehicle states are arranged. The liquid crystal display 80 can selectively display various vehicle states numerically or graphically. In the example of FIG. 4, on the right screen portion of the liquid crystal display 80, a temperature display portion 81 which is a temperature display screen is arranged, and various temperature states are displayed here in the form of a gauge chart (an example of a graph form). The temperatures that can be displayed on this temperature display portion 81 include the temperatures of various components (operating devices and control devices) mounted on this work vehicle, for example, the battery 6, the left traveling motor 41, the right traveling motor 42, the inverter 4, the mower motor 43, the cooler, the hydraulic equipment, or the temperature in its peripheral area. The control regarding the temperature display on the temperature display portion 81 will be described in detail later. On the operation panel 8A, an operation device group such as switches and dials for operating the operating devices mounted on the work vehicle is arranged. This operation device group includes an artificial operation tool 8a for selecting the display information displayed on the liquid crystal display 80 and for selecting the driving mode of the work vehicle.

[0025] As shown in FIG. 5, the control unit 5 includes, as control function parts, an input / output processing part 51, a traveling motor control part 52, a mower motor control part 53, a device control part 54, a rotation speed detection part 55, a vehicle speed control part 56, a state quantity display unit 7, and the like.

[0026] Connected to the input / output processing part 51 are a detection device group 9A, an equipment group 9B, the inverter 4, and the like. Therefore, the input / output processing part 51 also functions as a detection value input part for inputting detection values which are state quantities of various devices (components) detected by the detection device group 9A.

[0027] The detection device group 9A includes sensors for detecting the state quantities of a plurality of types of components. For example, as shown in FIG. 3, a left travel motor sensor 91 for detecting the rotational speed of the left travel motor 41, a right travel motor sensor 92 for detecting the rotational speed of the right travel motor 42, a mower motor sensor 93 for detecting the rotational speed of the mower motor 43, a left shift sensor 94 for detecting the operation amount of the left shift lever 17a, a right shift sensor 95 for detecting the operation amount of the right shift lever 17b, and other sensors (such as potentiometers). Further, the detection device group 9A also includes a temperature sensor group 90 for detecting the temperatures of various components.

[0028] As sensor signals related to vehicle speed control, the rotational speed of the cutting blade 31 (the rotational speed of the mower motor 43), the operation amount of the left shift lever 17a, and the operation amount of the right shift lever 17b are sent from the detection device group 9A to the control unit 5.

[0029] Based on the vehicle speed control signal from the vehicle speed control unit 56, the travel motor control unit 52 generates a motor control signal and drives the inverter 4 to independently drive and control the left travel motor 41 and the right travel motor 42.

[0030] Based on a preset default working rotational speed, the mower motor control unit 53 generates a motor control signal and drives the inverter 4 to drive and control the mower motor 43. If there is a working rotational speed setting tool for arbitrarily setting the working rotational speed, it is also possible to drive and control the mower motor 43 based on the working rotational speed set by the working rotational speed setting tool.

[0031] In addition to managing the operations of the equipment group 9B, the equipment control unit 54 also has a function of converting various information to be notified to the driver into notification signals and driving notification devices such as buzzers and speakers.

[0032] Based on the rotational speed sensor signal from the mower motor sensor 93 that detects the rotational speed of the mower motor 43, the rotational speed detection unit 55 detects the rotational speed of the mower motor 43 corresponding to the rotational speed of the cutting blade 31 as the working speed.

[0033] Based on the sensor signals from the detection device group 9A, the vehicle speed control unit 56 calculates the traveling speed of the vehicle body 1 and drives and controls the left traveling motor 41 and the right traveling motor 42 based on the operation amount of the left shift lever 17a and the operation amount of the right shift lever 17b.

[0034] The state quantity display unit 7 is a general term for display control that displays various state quantities in the work vehicle. The state quantity display unit 7 includes an emergency degree calculation unit 71, a limit value management unit 72, a display data generation unit 73, and a display control unit 74.

[0035] As shown in FIG. 6, the emergency degree calculation unit 71 calculates the notified emergency degree normalized from the corresponding detected value and the corresponding limit value for each state quantity. For this reason, the detected values of each component (inverter 4, each motor 41, 42, 43, cooler, etc.) detected by the temperature sensor group 90 are given to the emergency degree calculation unit 71 through the input / output processing unit 51 which is a detected value input unit. Further, the emergency degree calculation unit 71 acquires the corresponding limit value from the limit value management unit 72 that manages the limit values associated with each of those state quantities. This limit value includes a first limit value that causes a functional limitation of each component and a second limit value that causes a stop of the component. That is, if the detected value of each component is the variable: Tn, and the first limit value and the second limit value of each component are the constants: TYn, TZn, (n is an integer and is a subscript for identifying the component), the relational expression for calculating the notified emergency degree: En is, for example, En = Γ(Tn; TYn; TZn), Here, Γ() represents an emergency degree calculation function or an emergency degree calculation algorithm obtained in consideration of normalization that appropriately adjusts the difference in the variable range and constants for each component. This relational expression can be easily constructed by a look-up table or the like. The emergency degree calculation unit 71 outputs the maximum value: Enmax of the notified emergency degree of each calculated component as a calculation result.

[0036] The calculation result output from the emergency level calculation unit 71 (including the maximum value of the notification emergency level, the name of the corresponding component, and the actual detected value of the correspondence) is given to the display data generation unit 73. Based on the calculation result, the display data generation unit 73 generates display data (graphic data) as shown in the temperature display unit 81 of FIG. 4. The generated display data is sent to the liquid crystal display (state quantity display unit) 80 and visualized. Since not only the temperature but also the name of the component corresponding to the temperature is displayed on the visualized display screen, when the name of another component suddenly appears while a specific component name is always displayed, the driver can thereby detect the occurrence of some kind of failure. In this embodiment, the control of the display data generation unit 73 and the liquid crystal display 80 is performed by a control command from the display control unit 74.

[0037] Next, one of the specific emergency level calculation algorithms will be described below. First, let the detected temperature of component: A be TA, its first limit value be TYA, and its second limit value be TZA. Similarly, let the detected temperature of component: B be TB, its first limit value be TYB, its second limit value be TZB, ···, and the detected temperature of component: E be TE, its first limit value be TYE, and its second limit value be TZE. Also, set the first limit value to 75% of the second limit value. Further, for each component (identified by n = A, ···, E), the normalized notification emergency level: f(n) shown as a percentage when the detected temperature is below the first limit value is obtained by the following formula, f(n)=(Tn / TYn)*0.75. Furthermore, the normalized notification emergency level: g(n) shown as a percentage when the detected temperature is between the first limit value and the second limit value is obtained by the following formula, g(n)=0.75+((Tn-TYn) / (TZn-TYn))*0.25. That is, the notification emergency level: En when the detected temperature is below the first limit value is f(n), and the notification emergency level: En when the detected temperature is between the first limit value and the second limit value is g(n), and the notification emergency level is a numerical value shown as a percentage corresponding to the detected temperature.

[0038] For example, in component: A, if its detected temperature: TA is less than or equal to the first limit value, the notification urgency: EA is f(A) = (TA / TYA) * 0.75, and if its detected temperature: TA is between the first limit value and the second limit value and less than or equal to the first limit value, the notification urgency: EA is g(A) = 0.75 + ((TA - TYA) / (TZA - TYA)) * 0.25 and becomes

[0039] Among the notification urgencies: En obtained in this way, the component indicating the maximum value is the component closest to the function stop, and its detected value (notification urgency) is displayed on the temperature display unit 81 together with the component name. As shown in FIG. 4, the detected value (temperature) display frame displayed on the temperature display unit 81 is an arc-shaped gauge chart with an angle of approximately 270 degrees. The maximum value displayed in this display frame corresponds to 100% notification urgency, and the relationship between the detected temperature and the notification urgency can be read from this display. That is, the gap between the displayed notification urgency and the function stop (second limit value) can be read. However, for a more visual effect, when the notification urgency is below the first limit value, the chart is filled with a first color, for example, blue, assigned to the area (first area) from 0% to the first limit value. When the notification urgency is between the first limit value and the second limit value, the chart is filled with a second color, for example, yellow, assigned to the area (second area) between the first limit value and the second limit value. Further, for example, when the notification urgency is 98% or more, the chart may be filled with a special color, for example, red, to warn of the function stop (vehicle body stop). In that case, when the notification urgency is between the first limit value and the second limit value, the filling color of the chart part in the first area may be the first color, and the filling color of the chart part in the second area may be the second color, or the entire chart may be filled with the second color. In the latter case, the driver can grasp whether the current temperature is below the first limit value, between the first limit value and the second limit value, or even approaching the second limit value just by checking the color of the chart. Note that regarding the color of the chart, instead of filling it with a single color, it may be a gradient display towards either the upper side or the lower side.

[0040] 〔Alternative Embodiment〕 (1) In the above-described embodiment, an electric lawn mower is taken as the work vehicle. However, lawn mowers driven by internal combustion engines, work vehicles other than lawn mowers, for example, agricultural work vehicles, civil engineering work vehicles, construction work vehicles, or multi-purpose vehicles, etc. are also included in the work vehicle of the present invention.

[0041] (2) In the above-described embodiment, temperature is taken as the state quantity. However, state quantities other than temperature, such as rotational speed, load, speed, noise, etc., can also be displayed by the state quantity display system of the present application.

[0042] (3) In the above-described embodiment, the first limit value and the second limit value of the state quantity (temperature) are set on the rising side. However, the first limit value and the second limit value may be set on the falling side (a value lower than the standard value).

[0043] (4) As the display form of the temperature display unit (state quantity display unit) 81, graph forms other than the arc-shaped gauge chart, bar graphs, pie charts, etc., and further display forms other than the graph form can also be adopted.

[0044] (5) In FIGS. 4 and 6, the arrangement of the functional blocks shown by the rectangular frames is for illustrative purposes. Each functional block can be arbitrarily integrated with other functional blocks or divided into a plurality of functional blocks.

[0045] Note that the configurations disclosed in the above embodiments (including other alternative embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments as long as there is no contradiction. Also, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope not departing from the object of the present invention.

Industrial Applicability

[0046] The present invention is applicable to a state quantity display system for displaying various state quantities in a work vehicle, and various work vehicles equipped with such a state quantity display system.

Explanation of Reference Numerals

[0047] 4: Inverter 4A: Inverter for Traveling Motor 4B: Inverter for Mower Motor 5: Control Unit 6: Battery 7: State Quantity Display Unit 8A: Operation Panel 8B: Display Panel 8a: Manual Operation Device 9A: Detection Device Group (State Quantity Detection Device Group) 9B: Equipment Device Group 18: Cooling Fan 51: Input / Output Processing Unit (Detection Value Input Unit) 71: Urgency Calculation Unit 72: Limit Value Management Unit 73: Display Data Generation Unit 74: Display Control Unit 80: Liquid Crystal Display (State Quantity Display Unit) 81: Temperature Display Unit 90: Temperature Sensor Group

Claims

1. A state quantity display system for displaying state quantities in a work vehicle, comprising: a detection value input unit for inputting detection values of the state quantities in a plurality of types of components; a limit value management unit for managing limit values associated with each of the state quantities; an urgency calculation unit for calculating a notification urgency normalized from the corresponding detection value and the corresponding limit value for each state quantity; a display control unit that selects the detection value corresponding to the state quantity with the maximum notification urgency and displays it on a state quantity display unit. A state quantity display system comprising the above components.

2. The limit value management unit manages, for each state quantity, a first limit value that causes a functional limitation of the corresponding component and a second limit value that causes the component to stop as the limit values. The state quantity display system according to claim 1, wherein the urgency calculation unit calculates the notification urgency for each state quantity by a function having the detection value as a variable and the first limit value and the second limit value as constants.

3. The display control unit displays, in a graph form in which the relationship between the detection value and the first limit value and the relationship between the detection value and the second limit value can be read, the state quantity with the maximum notification urgency on the state quantity display unit. The state quantity display system according to claim 2.

4. The graph form is a gauge chart, and the chart is color-coded into a first region up to the first limit value and a second region from the first limit value to the second limit value. The state quantity display system according to claim 3.

5. The component includes at least two of a battery, a motor, an inverter, a cooler, and hydraulic equipment, and the state quantity is the temperature of the component. The state quantity display system according to claim 1.

6. A work vehicle equipped with the state quantity display system according to any one of claims 1 to 5.

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