Work vehicle idling control system

Abstract

To provide a work vehicle idling control system capable of efficiently performing a work.SOLUTION: A work vehicle idling control system 1 is a system for controlling idling of a work vehicle 10. The work vehicle idling control system 1 includes an idling control section 30 that executes an idling operation after start of an engine. In the stopped state of the work vehicle where pressure oil is not transmitted to at least a travel device and a work device of the work vehicle 10 after start of the engine, when a temperature of engine cooling water is a predetermined temperature or lower, the idling control section 30 increases engine speed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an idle control system for a work vehicle. [Background technology]

[0002] In working vehicles such as construction machinery, it is generally necessary to warm up the engine for a certain period of time after starting it in order to improve the durability of the engine. For this reason, idling control is performed to keep the engine speed at low idling (hereinafter referred to as "low idling") rather than at the rated speed until the temperature of the engine cooling water reaches a certain temperature or higher (see Patent Document 1 below).

[0003] Conventionally, when an engine is started, the engine speed is fixed at low idle in order to perform the warm-up operation as described above. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 61-076142 Summary of the Invention [Problem to be solved by the invention]

[0005] However, because the engine was fixed at low idle before work began, the warm-up time was long, and even if work was to begin, the driver had to wait until the warm-up was complete, making it difficult to carry out work efficiently.

[0006] The present invention has been made in consideration of the above problems, and has an object to provide an idling control system for a work vehicle that enables work to be carried out efficiently. [Means for solving the problem]

[0007] [1] The idling control system for a work vehicle of this embodiment is a system that controls idling of the work vehicle. The idling control system for a work vehicle has an idling control unit that executes idling operation after engine start. The idling control unit increases the engine speed when the work vehicle is in a stopped state after engine start in which pressurized oil is not being transmitted to at least the travel device and the work device of the work vehicle and the temperature of the engine coolant is equal to or lower than a predetermined temperature.

[0008] [2] The idling control system for a work vehicle of this embodiment has a display unit with an information input function. It is preferable that the idling control unit determines whether or not idling up (hereinafter referred to as "idle up") has been selected via the display unit, and increases the engine speed when it is determined that idle up has been selected.

[0009] [3] In the idling control system for a work vehicle of this embodiment, it is preferable that the idling control unit further determines whether the engine turbo protection function is working or not, and increases the engine speed when it is determined that the engine turbo protection function is not working.

[0010] [4] In the idling control system for a work vehicle of this embodiment, it is preferable that the idling control unit further determines whether the DPF regeneration state is below a predetermined level, and increases the engine speed when it is determined that the DPF regeneration state is below the predetermined level. Effect of the Invention

[0011] The idling control system for a work vehicle of the present invention can transition to a high idle state at least when the work vehicle is stopped (not in work mode) after the engine has been started and the temperature of the engine coolant is below a predetermined temperature. Therefore, the vehicle is not fixed to a low idle state even before work begins, and the warm-up operation time can be shortened. Therefore, it is possible to provide an idling control system for a work vehicle that allows work to be performed efficiently without having to wait until the warm-up operation at low idle is completed when work is to be started. [Brief description of the drawings]

[0012] [Figure 1] 1 is a perspective view of a work vehicle equipped with an idling control system according to an embodiment, as viewed obliquely from the front side; [Diagram 2] 1 is a block diagram showing a configuration of an idling control system for a work vehicle according to an embodiment; [Diagram 3] FIG. 2 is a block diagram showing a configuration of an idling control unit. [Figure 4] 5 is a flowchart for explaining an idling control process of an idling control unit. [Diagram 5] FIG. 13 is a diagram for explaining the release of the safety bar. [Figure 6] 6A and 6B are diagrams showing the display screens of the display unit in this embodiment, where FIG. 6(a) is a diagram showing an idle-up setting operation screen, FIG. 6(b) is a diagram showing an idle-up setting completion screen, FIG. 6(c) is a diagram showing an engine coolant temperature setting display screen, and FIG. 6(d) is a diagram showing an idle-up function termination screen. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In the following description, when discussing up, down, left, and right, the bottom side of the work vehicle 10 will be referred to as the bottom and the side opposite the bottom as the top, and the left side of the work vehicle 10 when viewed from the rear will be referred to as the left, and the right side will be referred to as the right.

[0014] [Work vehicle configuration] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The idle control system 1 for a work vehicle according to the embodiment will be described by taking as an example a crawler-type skid steer loader with a bucket attached to the end of an arm as the work vehicle. FIG. 1 is a perspective view of a work vehicle equipped with an idle control system according to the embodiment, seen obliquely from the front side. In addition, the external configuration of a work vehicle 10 according to the embodiment is not the gist of the present invention, so will only be described briefly.

[0015] As shown in FIG. 1, the work vehicle 10 has a pair of left and right traveling devices 12 each having an endless track (crawler) 11, a main body frame 13 to which the traveling devices 12 are attached on the left and right, and a cabin 25 provided in the upper center of the main body frame 13.

[0016] The cabin 25 is formed in a box shape, and an operator seat 35 on which an operator sits facing the front of the vehicle is provided inside the cabin 25. A safety bar 70 is attached inside the cabin 25 to ensure the safety of the operator seated on the operator seat 35.

[0017] In the work vehicle 10, an operator can seated in the operator seat 35 and operate an operating lever to drive the traveling device 12 in response to the operation of the operating lever, thereby causing the work vehicle 10 to travel.

[0018] The work vehicle 10 is also provided with an engine 20 at a rear position of the cabin 25. The engine 20 is covered by left and right body frames 13. An engine control ECU (Electronic Control Unit) 22 (see FIG. 2) that provides overall control of the operation of the engine 20, and a battery (not shown) are provided inside the left and right body frames 13. The engine control ECU 22 is electrically connected to the engine 20 and the battery.

[0019] Piping (not shown) for circulating engine cooling water (coolant) is provided around the engine 20. A cooling water temperature sensor (e.g., thermostat) 24 (see FIG. 2) for measuring the temperature of the engine cooling water is provided at a predetermined position of the piping. The detection result of the engine cooling water temperature is transmitted to an engine control ECU 22. The engine control ECU 22 determines whether or not to perform idling control, which will be described later, based on the detection result from the cooling water temperature sensor 24 and information on whether or not work is being performed. Note that, as the cooling water temperature sensor 24, a type in which it is disposed at the engine outlet and a type in which it is disposed at the engine inlet are known, and either type may be used.

[0020] [Idling control system] Hereinafter, an idling control system 1 for a working vehicle that performs idling control based on the detection result from the cooling water temperature sensor 24 and information on whether or not work is being performed will be described with reference to Figs. 2 to 6. Fig. 2 is a block diagram showing the configuration of the idling control system 1 for a working vehicle according to an embodiment. Fig. 3 is a block diagram showing the configuration of the idling control unit 30. Fig. 4 is a flowchart for explaining the idling control process of the idling control unit 30. Fig. 5 is a diagram for explaining the bar release of the safety bar 70. Fig. 6 is a diagram showing a display screen of the display unit 60 according to an embodiment, Fig. 6(a) is a diagram showing an idle-up setting operation screen, Fig. 6(b) is a diagram showing an idle-up setting completion screen, Fig. 6(c) is a diagram showing an engine cooling water temperature setting display screen, and Fig. 6(d) is a diagram showing an idle-up function end screen. In Figs. 1 to 3, the same components as those shown in Fig. 1 are assigned the same reference numerals.

[0021] The idling control system 1 for a work vehicle includes an engine control ECU 22, a cooling water temperature sensor 24, a safety bar sensor 26, an engine speed sensor 27, an engine turbo protection detector 28, a DPF (Diesel Particulate Filter) regeneration state detector 29, and a display unit 60. The engine control ECU 22 includes an idling control unit 30 and a display control unit 40. The engine control ECU 22 is configured, for example, by a microcomputer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output port, and a communication port (not shown). Examples of signals input to the engine control ECU 22 include water temperature information from the cooling water temperature sensor 24, bar release information from the safety bar sensor 26, and rotation speed information from the engine speed sensor 27. Various control signals are output from the engine control ECU 22 via an output port. Examples of signals output from the engine control ECU 22 include a control signal to the fuel injection valve 21.

[0022] The display unit 60 is a touch panel monitor, and functions as a user interface that allows information to be input. This touch panel monitor has a display panel and a touch panel. The display panel is a liquid crystal panel or an organic EL (Electro Luminescence) panel, and displays various graphic information, text information, and buttons. The touch panel is provided over the display panel, and may be of the resistive or capacitive type.

[0023] The idling control unit 30 includes a main control unit (main controller) 130, a judgment unit 131, a calculation unit 132, an input unit 133, an output unit 134, and a storage unit 135. The main control unit 130 receives the judgment result from the judgment unit 131 and the calculation result from the calculation unit, and generates and outputs a control signal for adjusting the fuel injection amount of the fuel injection valve 21 of the engine 20, which is the control target. The engine speed is controlled by adjusting the fuel injection amount. The judgment unit 131 judges whether or not to increase the engine speed according to the detection results from the cooling water temperature sensor 24, the safety bar sensor 26, the engine speed sensor 27, the engine turbo protection detection unit 28, and the DPF regeneration state detection unit 29, and outputs the judgment result. The calculation unit 132 calculates the current engine speed based on the detection result from the engine speed sensor 27, and calculates a control amount (for example, the engine speed and the fuel injection amount) according to the judgment result. The input unit 133 receives detection results from the cooling water temperature sensor 24, the safety bar sensor 26, the engine revolution speed sensor 27, the engine turbo protection detection unit 28, and the DPF regeneration state detection unit 29, as well as information from the user via the display unit 60. The output unit 134 outputs a control signal from the main control unit 130 to a controlled object.

[0024] The display unit 60 is provided in front of the driver's seat in the cabin 25 of the work vehicle 10. The display unit 60 displays screens as shown in Fig. 6(a) to Fig. 6(d) based on a predetermined display control signal from the display control unit 40. For example, the setting operation screen for idling control displays an activation icon as an activation button for transitioning to cold weather idle-up (high idle) described later, as shown in Fig. 6(a). When activation of cold weather idle-up described later is completed, an activation completion icon as shown in Fig. 6(b) is displayed on the screen. The display unit 60 further displays a screen (see Fig. 6(c)) displaying the engine coolant water temperature setting and the engine speed, based on a predetermined display control signal from the display control unit 40. When cold weather idle-up is completed, the cold weather idle-up display is turned off (see Fig. 6(d)).

[0025] [Idling control method] The specific conditions and the manner in which idling control is performed will be described below with reference to the flowchart in Fig. 4. When the engine is started (ON) (step S101), the determination unit 131 determines the determination items (1) to (5) described later (step S102).

[0026] Here, the work vehicle 10 has two modes, a stop mode and a work mode. The stop mode refers to a state in which the vehicle is idling and in so-called warm-up operation (low-load operation for a while after the engine is started), and the work mode refers to a state in which the warm-up operation is completed and pressure oil (hydraulic oil) driven by the engine is transmitted to the traveling device and the working device, that is, a state in which the vehicle can run and the arm can be moved. The stop mode refers to a state in which the work vehicle 10 is stopped, but the stopped state does not simply mean that the vehicle is stopped, but refers to a state in which pressure oil driven by the engine has not yet been transmitted to the traveling device and the working device. The stop mode is determined to be a stopped state when, for example, the safety bar 70 provided in the cabin 25 of the work vehicle 10 is lifted up as shown in FIG. 5 (bar released state). Whether or not the bar is released is determined based on the release determination result from the safety bar sensor 26. The safety bar sensor 26 is, for example, a sensor that is disposed at a position where the safety bar 70 is lifted and detects when the safety bar 70 reaches a predetermined position, but is not limited to this as long as it can detect motion.

[0027] The engine turbo protection function monitors the outside air temperature and the coolant temperature, and limits the engine speed to a predetermined speed or less when the outside air temperature and the coolant temperature are lower than the cold weather temperature (for example, the outside air temperature is lower than -10°C and the coolant temperature is lower than 10°C). The condition for transitioning to the cold weather idle up state described later is that the engine turbo protection function must be disabled. When the coolant temperature is lower than the reference temperature of the coolant in the engine turbo protection function, priority is given to executing the engine turbo protection function. DPF regeneration refers to a process of collecting and burning particulate matter (PM) exhausted from a diesel engine vehicle, and the process level (DPF regeneration level) of collecting and burning the particulate matter is determined by the collection and combustion level measured by a purification unit (not shown) installed near the exhaust port. The DPF regeneration level is set in advance to level 1 (the lowest level), which is a level at which cold weather idling up is not a problem. The stages of the levels and their definitions are set appropriately. DPF regeneration can be operated manually, but once it is operated manually, it is not possible to transition to cold weather idle up until the operation is completed.

[0028] (Judgment item) (1) Determine whether the work mode is turned off (if it is turned off, it is determined to be valid). (2) Determine whether the cold weather idle up button displayed on the display unit 60 is selected (ON) (if the idle up button is ON, it is determined that it is enabled). (3) Determine whether the engine turbo protection function is working or not (if the engine turbo protection function is not working, it is determined to be valid). (4) Determine whether the DPF regeneration button displayed on the display unit 60 is turned on (if the DPF regeneration button is turned on, it is determined that the DPF regeneration button is valid). (5) Determine whether the DPF regeneration status is below the minimum level (Level 1) (if the DPF regeneration status is below Level 1, it is determined to be valid) If it is determined in step S102 that all of the above determination items (1) to (5) are valid, the process proceeds to step S103.

[0029] In step S103, the determination unit 131 determines whether the temperature of the cooling water (coolant temperature) detected by the cooling water temperature sensor 24 is equal to or lower than a first reference temperature (e.g., 20°C) set in advance. If the detected temperature of the cooling water is equal to or lower than the first reference temperature, the main control unit 130 controls the fuel injection valve 21 to increase the fuel injection amount of the fuel injection valve 21 and set the engine speed to 1800 rpm (so-called cold weather idling up state) (step S104). Note that, although the cooling water temperature of 20°C is shown as an example of the first reference temperature, the temperature is not limited to this value and is appropriately set depending on the usage environment of the work vehicle 10. Also, although an example of controlling the engine speed to 1800 rpm is shown, the temperature is not limited to this value and is appropriately set.

[0030] In step S105, the determination unit 131 determines whether the temperature of the coolant detected by the coolant temperature sensor 24 is equal to or higher than a second reference temperature (for example, 70°C) set in advance. If the detected coolant temperature is equal to or higher than the second reference temperature, the main control unit 130 controls the fuel injection valve 21 to reduce the fuel injection amount of the fuel injection valve 21 and set the engine speed to 600 to 1200 rpm (so-called low idle state) (step S106), and the process ends. Note that although the coolant temperature of 70°C is shown as an example of the second reference temperature, the second reference temperature is not limited to this value and can be set appropriately depending on the usage environment of the work vehicle 10. Also, although the engine speed is controlled to 600 to 1200 rpm as an example, the second reference temperature is not limited to this value and can be set appropriately.

[0031] If it is determined in step S102 that at least one of the determination items (1) to (5) is invalid, the process proceeds to step 106. This is because it is not appropriate to switch to the cold weather idle-up state. If it is determined in step S103 that the coolant temperature detected by the coolant temperature sensor 24 exceeds the first reference temperature, the process proceeds to step 106. This is because if the coolant temperature exceeds the first reference temperature, it does not take much time to warm up, and therefore there is no need to switch to the cold weather idle-up state.

[0032] If it is determined in step S105 that the cooling water temperature detected by the cooling water temperature sensor 24 is lower than the second reference temperature, the determination unit 131 determines whether or not all of the determination items similar to the determination items (1) to (5) in step S102 are valid (step S107). If it is determined that all of the determination items (1) to (5) are valid, the main control unit 130 controls the fuel injection valve 21 to adjust the fuel injection amount of the fuel injection valve 21 to maintain the engine speed at 1800 rpm (step S104). If it is determined in step S107 that at least one of the determination items (1) to (5) is not valid, the process proceeds to step 106. This is because there is no need to enter the cold weather idle-up state.

[0033] Thus, according to the working vehicle idling control system 1 according to the embodiment, at least when the working vehicle 10 is stopped (not in working mode) after the engine has been started and the temperature of the engine coolant is equal to or lower than a predetermined temperature, the vehicle can be shifted to the cold weather idle-up state. Therefore, even before work begins, the vehicle is not fixed to the low idle state, and the warm-up operation time can be shortened. Therefore, when work is to be started, the work can be performed efficiently without having to wait until the warm-up operation at low idle is completed.

[0034] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiment, the condition for transitioning to the cold-state idle-up state is that all of the determination items (1) to (5) are valid, but the control for transitioning to the cold-state idle-up state may be performed even when, for example, only the above-described determination item (1) or only the determination items (1) and (2) are valid. [Explanation of symbols]

[0035] 1...Idling control system for work vehicle, 10...Work vehicle (crawler loader), 11...Endless crawler, 12...Traveling gear, 13...Main body frame, 20...Engine, 21...Fuel injector, 22...Engine control ECU, 24...Cooling water temperature sensor, 25...Cabin, 26...Safety bar sensor, 27...Engine speed sensor, 28...Engine turbo protection detection section, 29...DPF regeneration state detection section, 30...Idling control section, 40...Display control section, 60...Display section, 70...Safety bar

Claims

1. An idling control system for a work vehicle that controls idling of the work vehicle, An idling control unit that executes idling operation after the engine is started, the idling control unit increases the engine speed when the work vehicle is in a stopped state in which pressure oil is not being transmitted to at least a traveling device and a working device of the work vehicle after the engine is started and the temperature of the engine cooling water is equal to or lower than a predetermined temperature.

1. An idling control system for a work vehicle.

2. 2. The work vehicle according to claim 1, A display unit having an information input function is provided, the idling control unit determines whether or not idling up has been selected via the display unit, and increases an engine speed when it is determined that idling up has been selected.

1. An idling control system for a work vehicle.

3. 2. The work vehicle according to claim 1, The idling control unit further determines whether an engine turbo protection function is working or not, and increases the engine speed when it is determined that the engine turbo protection function is not working.

1. An idling control system for a work vehicle.

4. 2. The work vehicle according to claim 1, The idling control unit further determines whether or not the DPF regeneration state is equal to or lower than a predetermined level, and increases the engine speed when it is determined that the DPF regeneration state is equal to or lower than the predetermined level.

1. An idling control system for a work vehicle.

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