WO2022202685A1

WO2022202685A1 - Work vehicle

Info

Publication number: WO2022202685A1
Application number: PCT/JP2022/012708
Authority: WO
Inventors: 成規飯島
Original assignee: いすゞ自動車株式会社
Priority date: 2021-03-26
Filing date: 2022-03-18
Publication date: 2022-09-29
Also published as: JP2022150119A

Abstract

In a work vehicle 1, a hydraulic oil Ol is supplied from an electric hydraulic pump 6 through a hydraulic circuit 13 to a hydraulic actuator 4, the hydraulic actuator 4 causes mounted equipment 3 installed in the work vehicle 1 to operate, the rotation rate of the electric hydraulic pump 6 is driven according to a target rotation rate Nm, and if an interruption is predicted in work in which the mounted equipment 3 is operated by the hydraulic actuator 4, the rotation rate of the electric hydraulic pump 6 is lowered from the target rotation rate Nm to thereby lower the operating speed of the mounted equipment 3.

Description

work vehicle

The present disclosure relates to a work vehicle, and more particularly to a work vehicle that drives body equipment using an electric hydraulic pump.

A technology has been proposed in which a vehicle is equipped with bodywork equipment such as garbage collection equipment, and hydraulic oil is supplied from an electric hydraulic pump to a hydraulic actuator via a hydraulic circuit, whereby the bodywork equipment is operated by the hydraulic actuator ( For example, see Patent Document 1). The electric hydraulic pump is powered by a battery.

Japanese Patent Application Laid-Open No. 2018-20641

If the amount of charge in the battery decreases significantly (or the amount of power consumed by the electric hydraulic pump increases) while the bodywork is being operated, there will be no power to operate the bodywork. work is interrupted. In order to avoid work interruptions, it is necessary to take measures such as increasing the chances of charging the battery at the station and increasing the size of the battery. In the case of an engine-mounted vehicle, it is also conceivable to take measures such as charging the battery by motor power generation using engine power.

However, increasing the chances of charging the battery at the station increases the frequency with which the vehicle returns to the station, reducing the efficiency of work using bodywork equipment. When the size of the battery is increased, the vehicle weight increases due to the increased weight of the battery, which increases the amount of energy required for running the vehicle, and reduces the running efficiency of the vehicle. When motor power generation is performed using engine power, fuel efficiency deteriorates due to an increase in engine driving opportunities. In addition, when the temperature of the battery deviates from a preset temperature range, the discharge capacity (also called allowable current) of the battery decreases. When the discharge capacity of the battery declines, the power to operate the body equipment cannot be secured, and work is interrupted. In order to solve these problems, it is very useful to reduce the power consumption of the battery during the operation of the body equipment to reduce the chances of charging the battery.

An object of the present disclosure is to provide a work vehicle that avoids interruption of work in which bodywork equipment is activated.

A work vehicle according to one aspect of the present disclosure includes an electric hydraulic pump that supplies hydraulic fluid to a hydraulic circuit, a battery that supplies electric power to the electric hydraulic pump, and a hydraulic actuator that is supplied with hydraulic fluid via the hydraulic circuit. and body equipment operated by the hydraulic actuator, the work vehicle includes a state acquisition device that acquires the state of the battery, a control device that controls the electric hydraulic pump, and the electric During the work in which the hydraulic pump is driven at a preset target rotation speed and the bodywork is operated by the hydraulic actuator, the control device detects the state of the battery acquired by the state acquisition device. When it is predicted that the work will be interrupted, control is performed to reduce the rotational speed of the electric hydraulic pump from the target rotational speed to reduce the operating speed of the mounting equipment.

According to the present disclosure, it is possible to reduce the power consumption of the battery when the bodywork equipment is in operation, thereby avoiding work interruptions.

FIG. 1A is an explanatory diagram illustrating a work vehicle of the present disclosure as viewed from the side. FIG. 1B is an explanatory diagram illustrating an operation panel arranged on the work vehicle of FIG. 1A. FIG. 2 is an explanatory diagram that schematically illustrates the arrangement relationship of each device in the work vehicle of FIG. 1A. FIG. 3 is an explanatory diagram illustrating rotational speed data. FIG. 4 is an explanatory diagram illustrating another embodiment of rotation speed data. FIG. 5 is an explanatory diagram illustrating the relationship between battery temperature and discharge capability. FIG. 6 is an explanatory diagram illustrating the relationship between the power consumption of devices other than the pump and the discharge capacity from the battery to the pump. FIG. 7 is an explanatory diagram illustrating a predetermined travel route of the work vehicle. FIG. 8 is an explanatory diagram illustrating, in the form of a control flow, a prediction method based on the amount of charge. FIG. 9 is an explanatory diagram illustrating a control flow executed in parallel with the control flow of FIG. FIG. 10 is an explanatory diagram illustrating a prediction method based on supplied power in the form of a control flow. FIG. 11 is an explanatory diagram illustrating a control flow executed in parallel with the control flow of FIG. 10; FIG. 12 is an explanatory diagram illustrating past data. FIG. 13 is an explanatory diagram illustrating, in the form of a control flow, a prediction method based on the number of times of actuation. FIG. 14 is an explanatory diagram illustrating a control flow following the control flow of FIG. 13;

The work vehicle of the present disclosure will be described below based on the illustrated embodiment. The "side view" in FIG. 1A means "seen from the width direction of the vehicle (vehicle width direction)".

A work vehicle 1 of the present disclosure illustrated in FIGS. 1A and 2 is an electric vehicle that uses a motor generator 2 as a power source for vehicle travel. The motor-generator 2 is driven to rotate using electric power charged in a battery 8, which will be described later, so that the work vehicle 1 travels via wheels (not shown). The motor generator 2 charges the battery 8 by regeneratively generating power through the wheels when the work vehicle 1 is running inertially or decelerated. The motor generator 2 may be a motor for running that has only a running function without a regenerative power generation function. In this embodiment, the work vehicle 1 is not equipped with an engine, but may be a hybrid vehicle that uses both the engine and the motor generator 2 as power sources for vehicle travel.

The work vehicle 1 includes a mounting equipment 3 , a hydraulic actuator 4 , an operation panel 5 , an electric hydraulic pump (hereinafter referred to as pump) 6 having a motor 7 , and a battery 8 . In this embodiment, the work vehicle 1 further includes a charge amount sensor 9, a battery temperature sensor 10a, a power consumption sensor 10b, a navigation system (current position acquisition device) 11, and a control device 12. there is

Garbage collection equipment for collecting garbage D such as household garbage is exemplified as the mounting equipment 3 . The mounting equipment 3 is configured to be operable by a hydraulic actuator 4 . The mounting equipment 3 is configured to operate while the motor generator 2 is stopped. In this embodiment, the mounting equipment 3 is a well-known rotating plate type equipment and is configured to have a rotating plate 3a and a pushing plate 3b. The rotating plate 3a is arranged inside a garbage loading box 3c mounted on the working vehicle 1. As shown in FIG. The rotary plate 3a is rotatable with the vehicle width direction as the rotation axis direction. The rotating plate 3a scrapes the garbage D thrown into the inside of the garbage loading box 3c from the garbage inlet 3d provided on the outer surface of the garbage loading box 3c toward the garbage storage box 3e connected to the garbage loading box 3c. configured to be raised. The pushing plate 3b is arranged inside the garbage loading box 3c above the rotating plate 3a. The pushing plate 3b is configured to be slidable in the longitudinal direction of the vehicle. The pushing plate 3b is configured to be able to push the dust D raked up by the rotating plate 3a into the dust storage box 3e. The rotary plate 3a and the pushing plate 3b are arranged at positions where the raking of the rotary plate 3a and the pushing of the pushing plate 3b do not interfere with each other. The mounting equipment 3 may be equipment that is hydraulically driven using the hydraulic actuator 4, and may be, for example, a cleaning equipment that cleans with high-pressure water or a suction equipment that sucks sludge.

The hydraulic actuator 4 is connected to the mounting equipment 3 and configured to be able to supply hydraulic oil Ol through the hydraulic circuit 13 . In this embodiment, the hydraulic actuators 4 are a hydraulic motor 4a connected to the rotary plate 3a and a hydraulic cylinder 4b connected to the pushing plate 3b. The hydraulic motor 4a is arranged inside the garbage loading box 3c, and is configured to rotate the rotary plate 3a by the rotation of the hydraulic motor 4a. The hydraulic cylinder 4b is arranged inside the garbage loading box 3c, and is configured to be able to slide on the pushing plate 3b by sliding the hydraulic cylinder 4b.

The hydraulic motor 4a and the hydraulic cylinder 4b are driven by hydraulic oil Ol circulating in the hydraulic circuit 13. Each of the hydraulic pressure and oil amount of the hydraulic oil Ol supplied to the hydraulic motor 4a is positive with respect to the two parameters of the rotational torque of the rotary plate 3a (the power to rake up the dust D) and the rotational speed of the rotary plate 3a. There is a correlation. The hydraulic pressure and oil amount of the hydraulic oil Ol supplied to the hydraulic cylinder 4b are positively correlated with two parameters: the torque of the pushing plate 3b (the force pushing in the dust D) and the rotation speed of the pushing plate 3b. It is in.

The operation panel 5 is arranged near the driver's seat of the work vehicle 1 or the mounting equipment 3 . The operation panel 5 includes a power switch 5a, an operation start switch 5b, an operation stop switch 5c, and a control prohibition switch 5d, as shown in FIG. 1B. The power switch 5a is for switching on/off the power of the mounting equipment 3 by the operator's operation. The operation start switch 5b is for starting the operation of the mounting equipment 3 by the operator's operation. The operation stop switch 5c is for stopping the operation of the mounting equipment 3 by the operator's operation. The control prohibition switch 5d is a switch for manually prohibiting control for reducing the operation speed of the bodywork 3, which will be described later, by an operator's operation.

In this embodiment, the operation panel 5 further includes an adjustment switch 5e. The adjustment switch 5e can manually adjust the rotation speed of the pump 6 by the operator's operation. The adjustment switch 5 e is configured as a plurality of switches corresponding to the magnitude of the rotation speed of the pump 6 . In this embodiment, the adjustment switch 5e is configured as a plurality of switches of "large", "medium", and "small" according to the magnitude of the rotation speed of the pump 6. FIG. The "large" switch is operated by the operator to manually increase the rotation speed of the pump 6 to a relatively large value. The "small" switch is operated by the operator to manually reduce the number of revolutions of the pump 6 to a relatively small value. The "middle" switch is operated by the operator to manually set the number of revolutions of the pump 6 to a number intermediate between the number of revolutions set for "large" and the number of revolutions set for "small". It should be noted that the operation panel 5 may not be provided with the adjustment switch 5e.

The pump 6 is connected to the hydraulic actuator 4 via a hydraulic circuit 13 and is configured to be able to drive the hydraulic actuator 4 by supplying hydraulic oil Ol. The pump 6 is an electric hydraulic pump driven by rotational power of a motor 7 driven by electric power of a battery 8 . The pump 6 is a positive displacement pump, and has a characteristic that the pressure of the discharged hydraulic oil Ol is a fixed value, and the flow rate of the discharged hydraulic oil Ol is in a positive correlation with the rotation speed of the pump 6 . The pressure of the hydraulic oil Ol discharged by the pump 6 when the mounting equipment 3 is operated is set to the extent that the operation of the mounting equipment 3 (rotational torque of the rotary plate 3a and pushing force of the pushing plate 3b) is not hindered. It is a configuration that becomes the pressure of The pump 6 may be any positive displacement pump, such as a vane pump and a gear pump.

The pump 6 is configured to pump up the hydraulic oil Ol stored in the tank 14 to the hydraulic circuit 13 and supply the pumped hydraulic oil Ol to the hydraulic actuator 4 to drive the hydraulic actuator 4 . The pumped hydraulic oil Ol is circulated to the respective hydraulic actuators 4 (4a, 4b) by the operation control valves 15 (15a, 15b) arranged in the hydraulic circuit 13 . An excess amount of the pumped hydraulic oil Ol is directly returned to the tank 14 by a relief valve 16 arranged in the hydraulic circuit 13 . The control device 12 controls the flow rate adjustment of the hydraulic oil Ol to the hydraulic motor 4a and the hydraulic cylinder 4b by adjusting the opening degree of the operation control valve 15 . The opening adjustment of the relief valve 16 is controlled by the controller 12 . It should be noted that the hydraulic circuit 13 may be provided with known devices such as an accumulator, regulator, and filter as required. In FIG. 2, the hydraulic circuit 13 is indicated by a solid line, the electricity supply circuit is indicated by a broken line, and the control signal is indicated by a dashed line.

The motor 7 is provided in the pump 6 and is configured to be able to drive the pump 6 by rotating the motor 7 . The rotation of the motor 7 is interlocked with the rotation of the pump 6, and the number of rotations of the motor 7 and the number of rotations of the pump 6 are in a positive correlation. The battery 8 is configured to be able to supply electricity to the motor 7 or the motor generator 2 via the inverter 17 . In addition to the motor generator 2 and the motor 7, auxiliary equipment such as an air conditioner for a vehicle is connected to the battery 8 via an inverter 17, so that electricity can be supplied to the auxiliary equipment as well.

The inverter 17 is configured to be able to drive the motor generator 2 and the motor 7, and converts alternating current to direct current or direct current to alternating current between the motor generator 2 and motor 7 and the battery 8. The rotation speed of the motor 7 instructed by the inverter 17 is controlled by the controller 12 . Although the inverter 17 is shared by the motor generator 2 and the motor 7 in this embodiment, the motor generator 2 and the motor 7 may each have a dedicated inverter.

A state acquisition device that acquires the state of the battery 8 is arranged in the work vehicle 1 . In this embodiment, a charge sensor 9, a battery temperature sensor 10a, and a power consumption sensor 10b are used as status acquisition devices. In the present disclosure, the state of the battery 8 is the amount of charge S of the battery 8 and the amount of power Wp that can be supplied from the battery 8 to the pump 6 . The charge amount S of the battery 8 is the ratio of the current power amount to the total power amount in the fully charged state of the battery 8 , and is acquired by the charge amount sensor 9 . The amount of power Wp that can be supplied from the battery 8 to the pump 6 is a value based on the discharge capacity (also called allowable current) of the battery 8 and the amount of power Wr consumed by devices other than the pump 6 . The discharge capability of battery 8 is detected from temperature T of battery 8 . The amount of power Wp that can be supplied from the battery 8 to the pump 6 is the discharge capacity of the battery 8 obtained from the temperature T of the battery 8 obtained by the battery temperature sensor 10a and the power consumption Wr obtained by the power consumption sensor 10b. is calculated by the control device 12 based on

Various known sensors can be used as these

sensors

9, 10a, and 10b. These

sensors

9 , 10 a , 10 b are electrically connected to the control device 12 and the data detected by these

sensors

9 , 10 a , 10 b are input to the control device 12 . Instead of these

sensors

9, 10a, and 10b, a known computing device that computes the charge amount S and power consumption Wr of the battery 8 using various parameters may be used. Further, since the total power amount of the battery 8 is the specification value, the charge amount S and the current power amount of the battery 8 are mutually convertible values.

The navigation system 11 is installed in the work vehicle 1 and guides the travel route of the work vehicle 1 to the destination. The navigation system 11 is an example of a current position acquisition device.

A computer is used as the control device 12. The controller 12 controls various operations such as the operation of the operation control valve 15, the relief valve 16 and the inverter 17 described above, and also receives various inputs such as the charge amount S, temperature T, and power consumption Wr described above. Arithmetic processing is performed using the obtained data.

When the control device 12 predicts that the work in which the pump 6 is driven at the target rotation speed (target value of the rotation speed) Nm will be interrupted, the rotation speed of the pump 6 is lowered from the target rotation speed Nm to operate the body equipment 3. Perform control to reduce speed. In the present disclosure, work means that the pump 6 is driven by the power of the battery 8, the hydraulic actuator 4 is driven by hydraulic oil Ol supplied from the driven pump 6, and the body equipment 3 is operated by the driven hydraulic actuator 4. It is done.

The prediction that the work will be interrupted is based on the charge amount S of the battery 8, and the amount of electric power for bodywork set for operation of the bodywork equipment 3 out of the electric energy charged in the battery 8 will be used up. It is to predict. Predicting that the work will be interrupted is predicting that the operation of the bodywork 3 will stop due to a decrease in the amount of electric power Wp that can be supplied from the battery 8 to the pump 6 . It is also possible to predict that the amount of electric power for bodywork will be used up based on the number of times the bodywork equipment 3 is operated when traveling along a known travel route.

The control device 12 of the present embodiment predicts that the amount of electric power for bodywork will be used up based on the amount of charge S of the battery 8 during work, and the amount of power Wp that can be supplied from the battery 8 to the pump 6 decreases. 3 will stop working.

As illustrated in FIG. 3, the control device 12 stores rotation speed data 12a in the form of a control map. The rotational speed data 12a is data used when it is predicted based on the charge amount S of the battery 8 that the electric energy for bodywork will be used up. In this embodiment, the rotational speed data 12a is data representing the correlation between the charge amount S of the battery 8 and the target rotational speed (target value of the rotational speed) Nm of the pump 6 . The target rotation speed Nm is a value set through experiments, simulations, or the like, and is a value at which the operating speed of the mounting equipment 3 becomes a speed appropriate for the dust collection work of the worker (the driver of the work vehicle 1). In this embodiment, the target rotation speed Nm is set to a preset constant upper limit value Na. Note that the rotation speed data 12a may be data expressed in other forms such as mathematical expressions.

For the charge amount S of the battery 8, a lower limit charge amount Smin and a charge amount threshold Sa are set. The lower limit charge amount Smin is a lower limit value that permits operation of the bodywork 3, and various methods are exemplified for its setting. The lower limit charging amount Smin is set based on the amount of power for bodywork that is set in advance for operating the bodywork equipment 3 among the power amounts charged in the battery 8 . The amount of electric power charged in the battery 8 at that point in time is obtained from the amount of charge in the battery 8 obtained at the start of the work in which the bodywork 3 is operated. Next, a value is obtained by subtracting the amount of power for mounting from the obtained amount of power. Next, the ratio of the obtained value to the total electric energy is obtained, and the obtained ratio becomes the lower limit charging amount Smin.

The amount of electric power for bodywork may be a preset fixed value. A value obtained by subtracting the estimated amount of power consumption to be consumed may be used. When the bodywork power amount is a fixed value, it is possible to obtain the amount of decrease in the charge amount of the battery 8 when the bodywork power amount is completely consumed. may be subtracted to obtain the lower limit charging amount Smin. When the travel route of the work vehicle 1 is known, the predicted power consumption fluctuates as the work progresses. The charge amount threshold Sa is a value indicating a charge amount larger than the lower limit charge amount Smin, and is set through experiments, simulations, and the like.

As illustrated in FIGS. 4 to 6, the control device 12 stores rotation speed data 12b in the form of a control map. The rotational speed data 12b is data used when it is predicted that the operation of the mounting equipment 3 will stop due to a decrease in the amount of electric power Wp that can be supplied from the battery 8 to the pump 6. FIG. In this embodiment, the rotational speed data 12b is data representing the correlation between the amount of power Wp that can be supplied from the battery 8 to the pump 6 and the target rotational speed Nm of the pump 6 . The amount of power Wp that can be supplied from the battery 8 to the pump 6 is determined by the correlation between the temperature T of the battery 8 and the discharge capacity W of the battery 8, the amount of power Wp that can be supplied from the battery 8 to the pump 6, and devices other than the pump 6. and the correlation with the power consumption Wr. A power amount Wp that can be supplied from the battery 8 to the pump 6 is set with a lower limit power amount Wmin and a power amount threshold Wa. The lower limit power amount Wmin indicates the minimum amount of power that can operate the mounting equipment 3 when the rotation speed of the pump 6 is set to the target rotation speed Nm. When the amount of electric power Wp is lower than the lower limit amount of electric power Wmin, the operation of the bodywork 3 is stopped. The power amount threshold Wa is a value indicating a power amount greater than the lower limit power amount Wmin, and is set through experiments, simulations, and the like. Also in the rotation speed data 12b, the target rotation speed Nm is set to the constant upper limit value Na. Note that the rotation speed data 12b may be data expressed in other forms such as mathematical expressions.

The control device 12 also stores the upper limit value of the pressure of the hydraulic oil Ol flowing through the hydraulic circuit 13 . The control device 12 is configured to open the relief valve 16 and adjust the actual pressure to less than the upper limit when the actual pressure of the hydraulic oil Ol flowing through the hydraulic circuit 13 exceeds the upper limit. The actual pressure of the hydraulic oil Ol is detected by a pressure sensor arranged in the hydraulic circuit 13, for example.

As shown in FIG. 7, the control device 12 has a work vehicle 1 in which a plurality of work points (garbage D collection points) using the mounting equipment 3 and stations St for charging the battery 8 are scattered at intervals. is also stored. In this embodiment, the travel route R is interspersed with four work points a, b, c, d. The travel route R is set in advance through experiments, simulations, and the like. A plurality of travel routes R may be stored in the control device 12 .

A prediction method based on the amount of charge of the battery 8 will be described with reference to FIGS. 8 and 9. FIG. The control flows illustrated in FIGS. 8 and 9 are executed periodically and in parallel when the work vehicle 1 is stopped and the power switch 5a is turned on by the worker. This control flow is a flow in the case of predicting that the amount of power for bodywork will be used up based on the amount of charge S of the battery 8 . In this control flow, it is assumed that the rotation speed of the pump 6 is set to the target rotation speed Nm at the start.

When the control flow of FIG. 8 starts, in step S110, the operator presses the operation start switch 5b to start the operation of the mounting equipment 3, and determines whether or not to start the work using the mounting equipment 3. judge. If it is determined to start the operation of the mounting equipment 3 (YES), the process proceeds to step S120. If it is determined not to start the operation of the bodywork 3 (NO), the control flow of FIG. 8 is terminated. In step S120, the charge amount S of the battery 8 is acquired using the charge amount sensor 9. FIG. After performing step S120, the process proceeds to step S130. In step S130, the lower limit charge amount Smin is calculated by subtracting the amount of decrease in the case where the above-described amount of power for mounting is consumed from the charge amount S obtained in step S120. After performing step S130, the process proceeds to step S140. In step S140, the charge amount threshold value Sa is set using the lower limit charge amount Smin calculated in step S130. After executing step S140, the control flow in FIG. 8 ends.

The amount of power for mounting is calculated by the control device 12 based on the past data 12c illustrated in FIG. Although the details of the past data 12c will be described later, in this embodiment, the past data 12c is data that includes the power consumption for traveling Wt and the power consumption for work Wo for each work point. The traveling power consumption Wt is the power consumed by the battery 8 in each section from the start to the end of movement from the work point to another work point. The power consumption Wo for work is the amount of power consumed by the battery 8 from the start to the end of the work by the bodywork 3 at the work point. In this embodiment, the power consumption Wt for running in each section is indicated by Wt1 to Wt5, and the total value (=Wt1+Wt2+Wt3+Wt4+Wt5) is indicated by Wt6. In this embodiment, the work power consumption Wo at each work point is indicated by Wo1 to Wo4, and the total value (=Wo1+Wo2+Wo3+Wo4) is indicated by Wo5.

The initial value of the amount of power for bodywork is set to the total value Wo5 of the amount of power for work, or the value obtained by adding a margin to the total value Wo5. The amount of electric power for bodywork is obtained by subtracting the actual value of electric power consumption for work actually consumed at a work point where the work has already been completed from the initial value. These actual values are obtained by time-integrating the amount of electric power Wr that can be supplied from the battery 8 to the pump 6 with the work time at each work point. In this way, the amount of power for bodywork is updated at any time at the start of work.

The control flow in FIG. 9 is performed after steps S110 to S140 in FIG. 8 are executed once after the work vehicle 1 has stopped. When the control flow of FIG. 9 starts, the charge amount S of the battery 8 is acquired using the charge amount sensor 9 in step S210. After performing step S210, the process proceeds to step S220. In step S220, it is determined whether or not the charge amount S acquired in step S210 is smaller than the charge amount threshold value Sa set in step S140 of FIG. If the charge amount S is equal to or greater than the charge amount threshold Sa (NO), the control flow of FIG. 9 is restarted from step S210. If the charge amount S is less than the charge amount threshold value Sa (YES), the process proceeds to step S230. In step S230, the target rotation speed Nm of the pump 6 is decreased to the lower limit value Nb. After performing step S230, the process proceeds to step S240. In step S240, it is determined whether or not the charge amount S obtained in step S210 is smaller than the lower limit charge amount Smin calculated in step S130 of FIG. If the charge amount S is equal to or greater than the lower limit charge amount Smin (NO), the control flow of FIG. 9 is restarted from step S210. If the charge amount S is less than the lower limit charge amount Smin (YES), the process proceeds to step S250. In step S250, the pump 6 is automatically stopped. After performing step S250, the control flow in FIG. 9 ends. 8 and 9 are forcibly terminated when the operation end switch 5c is operated by the operator during execution of the control flow of FIGS. Further, when the pump 6 is automatically stopped in step S250, it is necessary for the operator to return to the station St once to charge the battery 8. FIG.

A prediction method based on the amount of power Wp that can be supplied from the battery 8 to the pump 6 will be described with reference to FIGS. 10 and 11. FIG. The control flows illustrated in FIGS. 10 and 11 are executed periodically and in parallel when the work vehicle 1 is stopped and the power switch 5a is turned on by the worker. This control flow is a flow for predicting that the amount of electric power for bodywork will be used up based on the amount of electric power Wp that can be supplied from the battery 8 to the pump 6 . In this control flow, it is assumed that the rotation speed of the pump 6 is set to the target rotation speed Nm at the start.

When the control flow of FIG. 10 starts, in step S310, the operator presses the operation start switch 5b to start the operation of the mounting equipment 3, and determines whether or not to start the work using the mounting equipment 3. judge. If it is determined to start the operation of the mounting equipment 3 (YES), the process proceeds to step S320. If it is determined not to start the operation of the mounting equipment 3 (NO), the control flow of FIG. 10 is terminated. In step S320, the discharge capacity W of the battery 8 and other power consumption Wr other than the pump 6 are acquired using the detection data of the battery temperature sensor 10a and the power consumption sensor 10b. After performing step S320, the process proceeds to step S330. In step S330, the amount of power Wp that can be supplied from the battery 8 to the pump 6 is calculated using the discharge capacity W and the amount of power consumption Wr acquired in step S320. After executing step S330, the control flow of FIG. 10 is terminated.

The control flow in FIG. 11 is performed after steps S310 to S330 in FIG. 10 are executed once after the work vehicle 1 has stopped. When the control flow of FIG. 11 starts, in step S420, it is determined whether or not the power amount Wp acquired in step S410 is less than the power amount threshold Wa. If the power amount Wp is greater than or equal to the power amount threshold Wa (NO), the control flow of FIG. 11 is restarted from step S410. If the power amount Wp is less than the power amount threshold Wa (YES), the process proceeds to step S430. In step S430, the target rotation speed Nm of the pump 6 is decreased to the lower limit value Nb. After performing step S430, the process proceeds to step S440. In step S440, it is determined whether or not the power consumption Wp acquired in step S410 is less than the lower limit power consumption Wmin calculated in step S330 of FIG. If the electric energy W is equal to or greater than the lower limit electric energy Wmin (NO), the control flow of FIG. 11 is restarted from step S410. If the electric energy Wp is less than the lower limit electric energy Wmin (YES), the process proceeds to step S450. At step S450, the pump 6 is automatically stopped. After executing step S450, the control flow of FIG. 11 ends. 10 and 11, the control flow of FIGS. 10 and 11 is forcibly terminated when the operator operates the operation end switch 5c. Further, when the pump 6 is automatically stopped in step S450, it is necessary for the operator to return to the station St once to charge the battery 8. FIG.

As described above, in the vehicle 1 of the present disclosure, when it is predicted that the vehicle mounting power amount will be used up in either the prediction based on the charge amount S or the prediction based on the power amount Wp, the rotation of the pump 6 is lowered from the target rotation speed Nm to lower the operating speed of the mounting equipment 3.

According to the work vehicle 1 of the present disclosure, in a state in which the pump 6 is driven at the target rotation speed Nm, the rotation speed of the pump 6 is is lowered from the target rotation speed Nm to lower the operating speed of the mounting equipment 3 . The rotation speed of the pump 6 has a positive correlation with the rotation speed of the motor 7, and the rotation speed of the motor 7 has a positive correlation with the power consumption of the battery 8 per unit time. That is, when the rotation speed of the pump 6 decreases, the power consumption of the battery 8 per unit time also decreases. Therefore, by lowering the target rotation speed Nm of the pump 6, the power consumption of the battery 8 required for the operation of the mounting equipment 3 can be reduced.

By reducing the power consumption of the battery 8, there is no need to increase the size of the battery 8, and the chances of charging the battery 8 at the station St can be reduced. Specifically, since there is no need to increase the size of the battery 8 , there is no increase in vehicle weight due to an increase in the weight of the battery 8 , and deterioration in running efficiency of the work vehicle 1 can be suppressed. By reducing the chance of charging the battery 8 at the station St, the chance of traveling to the station St on the way of the travel route R of the work vehicle 1 is reduced, and the worker's work efficiency (collection efficiency of the garbage D) can be improved. . Since the power consumption of the battery 8 is reduced when the discharge capacity of the battery 8 is reduced, power for operating the bodywork 3 can be secured, and interruption of work can be avoided. Further, if the work vehicle 1 is an electric vehicle as in this embodiment, the battery 8 cannot be charged while the mounting equipment 3 is operating while the work vehicle 1 is stopped. Therefore, the effect of reducing the power consumption of the battery 8 becomes even greater.

Even if the rotation speed of the pump 6 is set to a rotation speed lower than the target rotation speed Nm when the mounting equipment 3 is in operation, the rotation speed per unit time of the rotary plate 3a and the number of pushes per unit time of the push-in plate 3b do not increase. it will only be less. That is, since the rotating torque of the rotating plate 3a and the pushing force of the pushing plate 3b are not affected at all, the dust D cannot be scraped up by the rotating plate 3a, and the dust D cannot be pushed in by the pushing plate 3b. There is no problem in driving 3.

The work vehicle 1 of the embodiment reduces the operating speed of the bodywork equipment 3 when it is predicted that the bodywork power amount will be used up based on the charge amount S of the battery 8 before the bodywork power amount is used up. . Therefore, compared to the case where the operating speed of the bodywork 3 is not reduced, the time from the time of prediction until the state of charge S of the battery 8 becomes less than the minimum state of charge Smin can be lengthened. That is, the number of operations of the mounting equipment 3 can be increased.

It is desirable that the work vehicle 1 calculates the lower limit charging amount Smin and the charging amount threshold Sa for each task. The amount of work done by the bodywork 3 varies from work point to work point. Therefore, in this way, it is advantageous to appropriately reduce the operating speed of the bodywork equipment 3 to ensure the required number of operations of the bodywork equipment 3 at each work point. Note that the lower limit charging amount Smin and the charging amount threshold Sa may be set to the same value at all work points.

It may be predicted that the operation of the body equipment 3 will stop based on the discharge capacity W of the battery 8 . Even in this way, it is advantageous to properly reduce the operating speed of the mounting equipment 3 and secure the number of times of operation of the mounting equipment 3 required at each work point.

When the rotation speed of the pump 6 is lowered from the target rotation speed Nm, the control by the control device 12 is simplified if the rotation speed is lowered to a certain lower limit value Nb. Therefore, the burden on the control device 12 can be reduced.

The past data 12c illustrated in FIG. 12 may be stored in the control device 12, and the rotation speed of the pump 6 during work in which the bodywork 3 is operated may be adjusted based on this past data 12c. The past data 12c is a history of when the work vehicle 1 traveled along the travel route R and performed work on the mounting equipment 3. FIG. The past data 12c is data that replaces the rotation speed data 12a in the adjustment control of the rotation speed of the pump 6. FIG. The past data 12c may be data based on a single history or data based on a plurality of histories (for example, an average value). The past data 12c is set in advance through experiments, simulations, or the like and stored in the control device 12. FIG.

The past data 12c is data that includes at least the number of operations A of the bodywork equipment 3 for each work point on the travel route R. In this embodiment, the past data 12c is data that also includes the travel power consumption Wt and the work power consumption Wo for each work point. The traveling power consumption Wt is the power consumed by the battery 8 from the start to the end of movement from the work point to another work point (in each section). The power consumption Wo for work is the amount of power consumed by the battery 8 from the start to the end of the work by the bodywork 3 at the work point. In this embodiment, the number of operations A at each work point (a to d) is indicated by A1 to A4, and the total value (=A1+A2+A3+A4) is indicated by A5. In this embodiment, the power consumption Wt for running in each section is indicated by Wt1 to Wt5, and the total value (=Wt1+Wt2+Wt3+Wt4+Wt5) is indicated by Wt6. In this embodiment, the work power consumption Wo at each work point is indicated by Wo1 to Wo4, and the total value (=Wo1+Wo2+Wo3+Wo4) is indicated by Wo5.

When the past data 12c is stored in the control device 12, the work vehicle 1 is provided with an operation frequency sensor (operation frequency acquisition device) 18 that acquires the operation frequency A of the mounting equipment 3, as illustrated in FIG. Various known sensors can be used as the operation number sensor 18 . The actuation number sensor 18 is electrically connected to the control device 12 , and the data detected by this sensor 18 is input to the control device 12 . Note that instead of the actuation number sensor 18, a known computing device that computes the actuation number A using various parameters such as the amount of electric power required for operation of the bodywork 3 per unit time may be used.

A control method for the work vehicle 1 will be described with reference to FIGS. 13 and 14. FIG. The control flows illustrated in FIGS. 13 and 14 are periodically executed when the work vehicle 1 is stopped and the power switch 5a is turned on by the operator.

When the control flow of FIG. 13 starts, the current position of the vehicle 1 on the travel route R is acquired using the navigation system 11 in step S510. In this embodiment, it is acquired at which of the work points a, b, c, and d the vehicle 1 is located. After performing step S510, the process proceeds to step S520. In step S520, the planned number of operations Ap from the current work point to the end of the last work point in the past data 12c is calculated. The current work point is the point where the work using the bodywork 3 is performed during the progress of this control flow. The final work point is the nearest work point (work point d in FIG. 7) from the side returning to the station St on the travel route R. For example, if the current work point is a, the planned number of operations Ap will be A2+A3+A4 using the past data 12c of FIG. After performing step S520, the process proceeds to step S530.

In step S530, the lower limit number of times Amin is set using the planned number of times of operation Ap calculated in step S520. The lower limit number of times Amin is set to a number of times at which there is a possibility that the work vehicle 1 may be hindered from traveling on the travel route R when the number of times Ar of the remaining operation of the mounting equipment 3 becomes less than the lower limit number of times Amin. The remaining number of operations Ar is a value obtained by subtracting the number of operations A acquired by the number of operations sensor 18 from the total number of operations A5 of the mounting equipment 3 in the past data 12c. The lower limit number of times Amin is set through experiments, simulations, etc., and is, for example, a value of about 80 to 90% of the planned number of times of operation Ap. After performing step S530, the process proceeds to step S540 in FIG.

In step S540, it is determined whether or not the operation start switch 5b is pushed by the operator to start the operation of the mounting equipment 3 and to start the work using the mounting equipment 3. If it is determined to start the operation of the mounting equipment 3 (YES), the process proceeds to step S550. If it is determined not to start the operation of the mounting equipment 3 (NO), the control flow of FIG. 14 is terminated. In step S550, the driving of the pump 6 is started, the rotation speed thereof is adjusted to the target rotation speed Nm, and the operation frequency A of the mounting equipment 3 is acquired using the operation frequency sensor 18. After performing step S550, the process proceeds to step S560. In step S560, the remaining number of operations Ar is calculated based on the number of operations A obtained in step S550 while the bodywork 3 is being operated by the hydraulic actuator 4 . After performing step S560, the process proceeds to step S570.

In step S570, it is determined whether or not the remaining number of operations Ar calculated in step S560 is smaller than the planned number of operations Ap calculated in step S520. If the remaining number of operations Ar is greater than or equal to the planned number of operations Ap (NO), the control flow of FIG. 14 is restarted from step S550. If the remaining number of operations Ar is smaller than the planned number of operations Ap (YES), the process proceeds to step S580. In step S580, the rotational speed of the pump 6 is reduced from the target rotational speed Nm to reduce the operating speed of the mounting equipment 3. After performing step S580, the process proceeds to step S590.

In step S590, it is determined whether or not the remaining number of operations Ar calculated in step S560 is less than the lower limit number of times Amin set in step S530. If the remaining number of operations Ar is greater than or equal to the lower limit number of times Amin (NO), the control flow of FIG. 14 is restarted from step S550. If the remaining number of operations Ar is less than the lower limit number of times Amin (YES), the process proceeds to step S600. At step S600, the pump 6 is automatically stopped. After performing step S600, the control flow of FIG. 14 ends. 13 and 14, the control flow of FIGS. 13 and 14 is forcibly terminated when the operation end switch 5c is operated by the operator. Further, when the pump 6 is automatically stopped in step S600, it is necessary for the operator to return to the station St once to charge the battery 8. FIG.

As described above, when the work vehicle 1 travels along the travel route R, the rotation speed of the pump 6 is adjusted in consideration of the progress of the work using the mounting equipment 3 . Therefore, it is advantageous to reduce the power consumption of the battery 8 when the bodywork 3 is in operation and reduce the chances of charging the battery 8 .

The work vehicle 1 may be configured such that the control device 12 performs control to reduce the operation speed of the mounting equipment 3 only by prediction based on the charge amount S of the battery 8 . The work vehicle 1 may be configured such that the control device 12 performs control to reduce the operating speed of the mounting equipment 3 only by prediction based on the amount of electric power Wp that can be supplied from the battery 8 to the pump 6 . The amount of power Wp that can be supplied from the battery 8 to the pump 6 may be determined based only on the discharge capacity of the battery 8 or based on the amount of power consumed by devices other than the pump 6 . However, as in the above-described embodiment, the work vehicle 1 predicts both the prediction based on the charge amount S of the battery 8 and the prediction based on the electric power amount Wp that can be supplied from the battery 8 to the pump 6. It is preferable that the control device 12 is configured to perform control to reduce the operating speed. Making both of these predictions is advantageous for reducing the frequency with which the work that actuates the bodywork 3 is interrupted.

When the rotation speed of the pump 6 is lowered to the lower limit value Nb using the

rotation speed data

12a, 12b and the past data 12c, the rotation speed of the pump 6 is reduced based on the data acquired by the

sensors

9, 10a, 10b, and 18 described above. It may be lowered gradually. Specifically, the rotation speed of the pump 6 may be gradually decreased as the charge amount S of the battery 8 and the power amount Wp that can be supplied from the battery 8 to the pump 6 decrease. The rotation speed of the pump 6 may be gradually decreased as the number of times A of the mounting equipment 3 is operated increases. In this way, the power consumption per unit time of the battery 8 is appropriately set according to the SOC of the battery 8, which is advantageous for reducing the power consumption of the battery 8. FIG.

If the rotation speed of the pump 6 is adjusted by the control device 12 during work using the mounting equipment 3, the operator may feel uncomfortable with the sudden adjustment of the rotation speed. Therefore, if the worker operates the control prohibition switch 5d to prohibit the rotation speed adjustment of the pump 6 by the control device 12 during the work using the mounting equipment 3, the worker can collect the dust D without discomfort. can.

When the mounting equipment 3 is operated according to the target rotation speed Nm of the pump 6 set on the control device 12 side, the operator may feel that the mounting equipment 3 is operating quickly or slowly depending on the work environment. Therefore, it is advantageous for the operator to operate the adjustment switch 5e to adjust the rotation speed of the pump 6 to a value according to the working environment, thereby improving the working efficiency of the operator.

In the case of a vehicle equipped with both an engine and a motor-generator 2, it is conceivable to charge the battery 8 by causing the motor-generator 2 or the motor 7 to generate electricity using the power of the engine when the body equipment 3 is in operation. be done. By reducing the power consumption of the battery 8 as described above, the chances of charging the battery 8 using the power of the engine are reduced. Therefore, the fuel efficiency of the engine can be improved.

This application is based on a Japanese patent application (Japanese Patent Application 2021-052577) filed on March 26, 2021, the contents of which are incorporated herein by reference.

The work vehicle according to the present disclosure can be widely applied to techniques for avoiding interruption of work in which body equipment is operated.

1 work vehicle 2 motor generator (running motor)
3 Body equipment 3a Rotating plate 3b Pushing plate 3c Garbage loading box 3d Garbage inlet 3e Garbage storage box 4 Hydraulic actuator 4a Hydraulic motor 4b Hydraulic cylinder 5 Operation panel 5a Power switch 5b Operation start switch 5c Operation stop switch 5d Control prohibition switch 5e adjustment switch 6 electric hydraulic pump 7 motor 8 battery 9 charge amount sensor (state acquisition device)
10a battery temperature sensor (status acquisition device)
10b Power consumption sensor (status acquisition device)
11 Navigation system (current position acquisition device)
12 Control device 12a Rotation speed data 12b Rotation speed data 12c Past data 13 Hydraulic circuit 14

Tanks

15, 15a, 15b Operation control valve 16 Relief valve 17 Inverter 18 Operation frequency sensor (operation frequency acquisition device)

Claims

An electric hydraulic pump that supplies hydraulic oil to a hydraulic circuit, a battery that supplies electric power to the electric hydraulic pump, a hydraulic actuator that is supplied with hydraulic oil via the hydraulic circuit, and body equipment operated by the hydraulic actuator and a work vehicle comprising:
A state acquisition device that acquires the state of the battery, and a control device that controls the electric hydraulic pump,
During the work in which the electric hydraulic pump is driven at a preset target rotation speed and the bodywork is operated by the hydraulic actuator, the control device detects the battery based on the state of the work vehicle, when it is predicted that the work will be interrupted, control is performed to reduce the rotation speed of the electric hydraulic pump from the target rotation speed to reduce the operating speed of the mounting equipment.
The state acquisition device acquires the charge amount of the battery as the state of the battery,
Based on the obtained charge amount of the battery, the control device predicts that the bodywork power amount preset for operating the bodywork equipment out of the power amount charged in the battery will be used up. 2. The work vehicle according to claim 1, wherein the control for lowering is performed in a case where
For each work, the control device provides a lower limit charge amount obtained by subtracting a decrease amount when the bodywork power amount is consumed from the charge amount acquired at the start of the work, and a charge amount larger than the lower limit charge amount. 3. The work vehicle according to claim 2, further comprising: calculating a threshold value, and comparing the charge amount obtained during operation of the bodywork equipment with the charge amount threshold value to predict that the bodywork power amount will be used up. .
The state acquisition device acquires, as the state of the battery, the discharge capacity of the battery and other power consumption other than the electric hydraulic pump,
The control device predicts that the operation of the bodywork will stop due to a decrease in the amount of electric power that can be supplied from the battery to the electric hydraulic pump, based on the obtained discharge capacity and the other electric power consumption. 4. The work vehicle according to any one of claims 1 to 3, wherein the control for lowering is performed when a
a device for obtaining the number of times of operation of the bodywork equipment, and a current position obtaining device for obtaining a current position,
The control device stores past data in which work was performed on the bodywork while traveling along a preset travel route dotted with a plurality of work points. including the number of actuations of the bodywork equipment,
The control device stores the remaining number of operations obtained by subtracting the number of operations acquired by the operation number acquisition device from the total number of operations of the bodywork equipment in the past data, and the current position acquired by the current position acquisition device. preset number of times of operation from the current work point to the end of the travel route in the past data based on the amount of electric power charged in the battery for the operation of the bodywork equipment. 2. The work vehicle according to claim 1, wherein the reduction control is performed when it is predicted that the installed bodywork electric energy will be used up.
When the rotation speed of the electric hydraulic pump is lowered from the target rotation speed, the control device reduces the rotation speed to a preset lower limit value, or the state of the battery acquired by the state acquisition device, Alternatively, the work vehicle according to any one of claims 1 to 5, wherein control is performed to gradually decrease based on the number of times of actuation acquired by the device for acquiring the number of times of actuation.
The work vehicle according to any one of claims 1 to 6, comprising a switch for manually prohibiting the control for reducing the operating speed.