RU2796215C1 - Industrial vehicle and method of control of industrial vehicle - Google Patents

Abstract

FIELD: industrial vehicles.

SUBSTANCE: industrial vehicle is comprised of an engine, a drive wheel, a driving force transmission mechanism, a driver's seat, a driver detection unit, and a controller. The driver detection unit is configured to determine a driver state from driver states including an absent state in which the driver leaves the driver's seat and a present state in which the driver sits in the driver's seat. The controller is configured to set the operating mode from the operating modes based on the driver's state determined by the driver detection unit. The operating modes include a normal mode, a limit mode which limits the driving force, and an interruption mode which interrupts the transmission of the driving force to the driving wheel by the driving force transmission mechanism. The controller includes an absence state detection unit, a limit setting unit, and an interrupt setting unit.

EFFECT: possibility of changing the operational characteristics of an industrial vehicle while driving is achieved.

6 cl, 6 dwg

Description

Technical field

The present invention relates to industrial

a vehicle and a method for driving an industrial vehicle.

State of the art

Japanese Patent Laying-Open Publication No. 2006-316942 discloses an industrial vehicle that is propelled by transmitting engine driving force to driving wheels through a driving force transmission device connected to the engine. When the driver exits the vehicle so that the landing signal of the landing detection switch is turned off, the controller of the industrial vehicle stops supplying power to the forward solenoid valve or the reverse solenoid valve after a predetermined delay time has elapsed. When the driver sits down again, the controller restarts the power supply of the forward or reverse solenoid valve if the landing signal of the landing detection switch is turned on, and the forward signal or reverse signal of the forward/reverse command switch is turned on after the controller determines that the direction of operation of the lever forward/reverse control is neutral.

The driver of an industrial vehicle may temporarily stand up, for example, to check the surroundings while driving. However, in the above configuration, when the non-landing state continues until the delay time elapses, the transmission of the driving force is interrupted. Such interruption of the transmission of the driving force changes the driving experience of the industrial vehicle. As the change in operating feel increases, the driving comfort for the driver may decrease significantly.

The essence of the invention

This summary of the claimed invention is provided to introduce a set of concepts in a simplified form, which will be further described later in the detailed description of the invention. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

In a general aspect, an industrial vehicle is provided that includes an engine, a drive wheel, a drive force transmission mechanism configured to transmit engine drive to the drive wheel, a driver's seat on which the driver sits, a driver detection unit, and a controller. The driver detection unit is configured to determine a driver state from driver states including an absent state in which the driver leaves the driver's seat and a present state in which the driver sits in the driver's seat. The controller is configured to set the operating mode from the operating modes based on the state of the driver detected by the driver detection unit. The operating modes include a normal mode, a limit mode which limits the driving force, and an interruption mode which interrupts the transmission of the driving force to the driving wheel by the driving force transmission mechanism. The controller includes an absence state detection unit, a limit setting unit, and an interrupt setting unit. The absence state determination unit is configured to determine when the driver's state is an inactive state, whether the duration of the absence state during which the inactive state continues is less than or equal to a predetermined absence state determination time. The restriction setting unit is configured to set the operation mode to the restriction mode when the absence state determination unit determines that the duration of the absence state is less than or equal to the absence state determination time. The interrupt setting unit is configured to set the operation mode to the interrupt mode when the absence state determination unit determines that the duration of the absence state exceeds the absence state determination time.

Other features and aspects will be apparent from the following detailed description, drawings and claims.

Brief description of the drawings

Fig. 1 is a perspective view of the entire industrial vehicle according to the first embodiment;

Fig. 2 is a diagram showing a system configuration of an industrial vehicle according to the first embodiment;

Fig. 3 is a flowchart showing a motion control process according to the first embodiment;

Fig. 4 is a flowchart showing a process in an absent state according to the first embodiment;

Fig. 5 is a flowchart showing a return process according to the first embodiment; And

Fig. 6 is a flowchart showing a process in the absence state according to the second embodiment.

Throughout the drawings and the detailed description, the same reference numerals refer to the same elements. The drawings may not be to scale, but the relative size, proportions, and depiction of elements in the drawings may be enlarged for clarity, illustration, and convenience.

Detailed description of the invention

This description provides a comprehensive understanding of the described methods, devices and/or systems. Modifications and equivalents to the described methods, devices and/or systems are obvious to a person skilled in the art. The sequence of operations is given as an example and can be changed for a person skilled in the art, with the exception of operations that must be performed in a certain order. Descriptions of functions and constructions that are well known to those skilled in the art may be omitted.

Typical embodiments may take various forms and are not limited to the examples described. However, the described examples are detailed and complete and disclose the entire scope of the disclosure to a person skilled in the art.

In this description, "at least one of A and B" should be understood to mean "only A, only B, or both A and B".

First embodiment of the invention

The industrial vehicle 10 according to the first embodiment will now be described.

Industrial vehicle 10

As shown in FIG. 1, an industrial vehicle 10 includes a body 11, two driving wheels 12, 13, two steering wheels 14, a driver's seat 15, and a handling device 20. The industrial vehicle 10 according to the present embodiment is a counterbalanced forklift.

Driving wheels 12, 13

Driving wheels 12, 13 are located in the front lower part of the vehicle body 11. The two drive wheels 12, 13 are separated from each other along the width of the vehicle.

Steering wheels 14

Two steerable wheels 14 are located in the rear lower part of the body 11 of the vehicle. The two steerable wheels 14 are separated from each other in the width direction of the vehicle.

Driver's seat 15

The driver's seat 15 is a seat on which the driver sits. The seat 15 of the driver is located in the upper part of the body 11 of the vehicle.

Handling device 20

The handling device 20 includes a mast 21, two forks 22 and lifting cylinders 23. The mast 21 is located in front of the body 11 of the vehicle. The forks 22 are raised and lowered together with the mast 21. A load is mounted on the forks 22. The lift cylinders 23 include hydraulic cylinders. The lifting cylinders 23 are extended or retracted to raise or lower the mast 21. The forks 22 are raised or lowered when the mast 21 is raised or lowered. The industrial vehicle 10 according to the present embodiment performs a travel operation and a load handling operation when driven by a driver.

As shown in FIG. 2, the industrial vehicle 10 includes a controller 31, an accelerator 16, an accelerator sensor 34, a direction commanding unit 17, a direction determining unit 35, a seat switch 18, a driver detection unit 36, a movement system 50, and a tire 40.

controller 31, processor 32 and memory 33

The controller 31 includes a processor 32 and a memory 33. The processor 32 may include, for example, a central processing unit (CPU), a graphics processing unit (GPU), or a digital signal processor (DSP). The memory 33 includes random access memory (RAM) and read only memory (ROM). Memory 33 stores programs for operating industrial vehicle 10. Memory 33 stores program codes or instructions configured to cause processor 32 to execute processes. The memory 33, which is a computer-readable medium, includes any type of medium that is available for a general purpose computer or a special purpose computer. Controller 31 may include hardware circuitry such as an application specific integrated circuit (ASIC) and a field programmable gate array (FPGA). The controller 31, which is a processing circuit, may include one or more processors that operate in accordance with a computer program, one or more hardware circuits such as ASICs and FPGAs, or a combination thereof.

Accelerator 16

The accelerator 16 is actuated by the driver when the vehicle body 11 accelerates. The accelerator 16 instructs the controller 31 to accelerate the industrial vehicle 10 in response to the driver's action. The accelerator 16 is, for example, an accelerator pedal. Accelerator 16 may be of any particular configuration and may be a switch, lever, touch pad, or the like.

Accelerator sensor 34

The accelerator sensor 34 detects the accelerator actuation amount, which is the actuation amount of the accelerator 16. The accelerator sensor 34 outputs an electrical signal corresponding to the amount of accelerator depression to the controller 31. The controller 31 obtains the accelerator actuated amount based on the electrical signal from the sensor 34 accelerator.

Block 17 command direction

The direction command input unit 17 is used to command the direction of movement of the vehicle body 11 in accordance with the controlled direction. The direction of movement of the vehicle body 11 is considered to be the direction of movement of the industrial vehicle 10. Specifically, the direction commanding unit 17 is a direction lever. The controlled direction includes a forward driving direction and a backward driving direction. The direction command input unit 17 is configured to operate in a forward direction or a backward direction with respect to the neutral position. The specific configuration of the direction commanding unit 17 is not limited to a direction lever, but may be a switch, a touch panel, or the like.

Block 35 determine the direction

The direction determination unit 35 determines the operation direction of the direction command supply unit 17 . The direction determining unit 35 is also referred to as a direction sensor. The direction determining unit 35 determines whether the direction command input unit 17 operates in the forward direction or in the backward direction relative to the neutral position of the direction command output unit 17 . The direction determining unit 35 outputs an electrical signal corresponding to the operation direction of the direction command supply unit 17 to the controller 31. The controller 31 obtains the set direction of the direction command supply unit 17 based on the electric signal from the direction determination unit 35 . The controller 31 recognizes whether the driver has given a forward command, whether the driver has given a reverse command, or whether the driver has given neither.

Switch 18 seats

The seat switch 18 is a mechanism that is activated when the driver is seated in the driver's seat 15 . The seat switch 18 is provided, for example, under the driver's seat 15 . The specific configuration of the seat switch 18 is not limited to a switch, but may be a pressure sensor, a weight sensor, an optical sensor, a camera, or the like.

Driver detection unit 36

The driver detection unit 36 is an electronic control unit that detects the state of the driver. The driver state includes an absent state and a presence state. In the absence state, the driver does not sit on the driver's seat 15 . In the presence state, the driver sits on the driver's seat 15 . The state of the driver is determined based on the detection result of the seat switch 18 . For example, when the seat switch 18 is turned on, the driver detection unit 36 determines that the driver state is the presence state. When the seat switch 18 is in the OFF position, the driver detection unit 36 determines that the driver's state is the absence state.

The driver state determination method is not limited to the above-described method, but may be any suitable method. For example, when a weight sensor is used as the mechanism corresponding to the seat switch 18, the driver detection unit 36 determines that the driver state is the presence state if the weight detected by the weight sensor is greater than or equal to a predetermined value, and determines that the driver state is the state absence if the weight detected by the load cell is less than the set value. When a camera is used as the mechanism corresponding to the seat switch 18, the driver detection unit 36 can extract a specified score from an image captured by the camera and determine the state of the driver based on the score. Examples of the score include the positional relationship between the driver and the driver's seat 15 in the image, the posture of the driver, and the like.

System 50 movement

The movement system 50 enables movement of the vehicle body 11 . The movement system 50 includes a motor 51, an output shaft 53, a rotation speed sensor 54, a driving force transmitting mechanism 60, a differential 70, an axle 71, a vehicle speed sensor 72, and a movement controller 73. The industrial vehicle 10 is a vehicle with an engine.

Engine 51

The engine 51 is a drive source for driving and handling operations of the industrial vehicle 10. The engine 51 according to the present embodiment is a gasoline engine that uses gasoline as a fuel. Motor 51 includes a throttle actuator 52. The fuel of the engine 51 is not limited to gasoline and may be, for example, liquefied petroleum gas (LPG) or compressed natural gas (CNG). The engine 51 is not limited to a gasoline engine, and may be a diesel engine, for example.

Actuator 52 Throttle

The throttle actuator 52 controls the degree of opening of the throttle valve. The throttle actuator 52 controls the opening degree of the throttle valve to control the amount of air supplied to the engine 51. Accordingly, the rotational speed of the engine 51 is controlled.

Output shaft 53

The output shaft 53 is connected to the motor 51. The output shaft 53 rotates under the action of the motor 51.

Speed sensor 54

A rotation speed (speed) sensor 54 is mounted on the output shaft 53. The rotation speed sensor 54 detects the rotation speed (rotation speed) of the motor 51. The rotation speed of the engine 51 is also the rotation speed of the output shaft 53. The rotation speed sensor 54 outputs an electrical signal corresponding to the speed rotation of the output shaft 53, to the controller 73 movement.

Driving force transmission mechanism 60

The driving force transmission mechanism 60 transmits the driving force of the engine 51 to the drive wheels 12, 13. The driving force transmission mechanism 60 includes a torque converter 61, a transmission 62, and two solenoid valves 69.

Torque Converter 61

The torque converter 61 is connected to the output shaft 53. The driving force of the engine 51 is transmitted to the torque converter 61 through the output shaft 53. The torque converter 61 includes a pump and a turbine connected to the output shaft 53. In the torque converter 61, the turbine is rotated by hydraulic oil, coming out of the pump.

Transmission 62

Transmission 62 includes input shaft 63, forward clutch 64, forward gear 65, reverse clutch 66, reverse gear 67, and output shaft 68.

Input shaft 63

Input shaft 63 is connected to torque converter 61. Driving force is transmitted from torque converter 61 to transmission 62 via input shaft 63.

Forward clutch 64 and forward gear 65

The forward clutch 64 is mounted on the input shaft 63. The forward gear 65 is located between the forward clutch 64 and the output shaft 68. The forward clutch 64 switches between an on and off state. The engaged state is a state in which the input shaft 63 and the front gear 65 are connected to each other. The unengaged state is a state in which the input shaft 63 and the front gear 65 are disconnected from each other. When the forward clutch 64 connects the input shaft 63 and the forward gear 65 to each other, the driving force is transmitted from the input shaft 63 to the forward gear 65. The driving force transmitted to the front gear 65 is then transmitted to the output shaft 68. When the forward clutch 64 is connected to the forward gear 65, the driving force of the motor 51 is transmitted to the output shaft 68. When the forward clutch 64 and the forward gear 65 travel are disconnected from each other, the driving force is not transmitted from the input shaft 63 to the gear train 65 forward.

Reverse clutch 66 and reverse gear 67

Reverse clutch 66 is located on input shaft 63. Reverse gear 67 is located between reverse clutch 66 and output shaft 68. Reverse clutch 66 switches between an on and off state. The engaged state is a state in which the input shaft 63 and the reverse gear 67 are connected to each other. The disconnected state is a state in which the input shaft 63 and the reverse gear 67 are disconnected from each other. When the reverse clutch 66 connects the input shaft 63 and the reverse gear 67 to each other, the driving force is transmitted from the input shaft 63 to the reverse gear 67 . The driving force transmitted to the reverse gear 67 is then transmitted to the output shaft 68. When the reverse clutch 66 is connected to the reverse gear 67, the driving force of the motor 51 is transmitted to the output shaft 68. When the reverse clutch 66 and gear 67 reverse are disconnected from each other, the driving force is not transmitted from the input shaft 63 to the reverse gear 67.

The forward clutch 64 and the reverse clutch 66 are hydraulic clutches. Hydraulic clutches can be wet multi-plate clutches.

Output shaft 68

The output shaft 68 receives a driving force when the forward clutch 64 or reverse clutch 66 is engaged. The output shaft 68 is rotated by the driving force transmitted from the forward clutch 64 or the reverse clutch 66 .

Solenoid valves 69

The two solenoid valves 69 correspond to the forward clutch 64 and the reverse clutch 66, respectively. Solenoid valves 69 control the supply and discharge of hydraulic oil to and from the forward clutch 64 and the reverse clutch 66. Solenoid valves 69 supply or release hydraulic oil according to the amount of electrical power supplied to the solenoids. Clutches 64, 66 are respectively switched between on and off by supplying and discharging hydraulic oil via solenoid valves 69. When the direction command supply unit 17 commands forward, the forward clutch 64 and front gear 65 are connected to each other. When the direction commanding unit 17 commands the reverse movement, the reverse clutch 66 and the reverse gear 67 are connected to each other. When the direction commanding unit 17 issues the neutral state command, that is, when the direction commanding unit 17 is in the neutral position, the forward clutch 64 and the reverse clutch 66 are turned off. When one of the forward clutch 64 and the reverse clutch 66 is engaged, resistance is generated in the engine 51 due to engine braking. In contrast, when the forward clutch 64 and the reverse clutch 66 are both disengaged, no resistance occurs in the engine 51 due to engine braking.

The solenoid valve 69 is configured to control the controller 31. The controller 31 regulates the amount of electricity supplied to the solenoids in the solenoid valves 69, thereby controlling the supply and discharge of hydraulic oil through the solenoid valve 69.

Differential 70 and axle 71

The differential 70 is connected to the output shaft 68. The axle 71 is connected to the differential 70. The drive wheels 12, 13 are connected to the axle 71. The axle 71 rotates when the output shaft 68 rotates. The industrial vehicle 10 moves when the drive wheels 12, 13 rotate due to rotation of the axle 71. When the forward clutch 64 and the forward gear 65 are connected to each other, the industrial vehicle 10 moves forward. When the reverse clutch 66 and the reverse gear 67 are connected to each other, the industrial vehicle 10 moves backward.

Vehicle speed sensor 72

The vehicle speed sensor 72 is a sensor for detecting a vehicle speed, that is, a moving speed of the vehicle body 11 . The speed of the vehicle body 11 is considered as the speed of the industrial vehicle 10. The vehicle speed sensor 72 is provided on the output shaft 68 or on the axle 71, for example. The vehicle speed sensor 72 outputs a pulse signal corresponding to the vehicle speed to the controller 73 movement.

73 movement controller

The motion controller 73 is an engine control unit that controls the motor 51. The hardware configuration of the motion controller 73 is, for example, the same as that of the controller 31. The motion controller 73 controls the throttle opening degree by controlling the throttle actuator 52. The driving force of the engine 51 is controlled by adjusting the opening degree of the throttle valve. The displacement controller 73 controls the solenoid valve 69 which switches the clutches 64, 66 between on and off. Accordingly, clutches 64, 66 switch between an on state and an off state.

The motion controller 73 and the controller 31 are configured to receive information from each other via the bus 40. The controller 31 transmits a predetermined command signal via the bus 40. Thus, the controller 31 controls the motor 51 via the motion controller 73. The command signal is, for example, a target torque value or a rotation speed of the engine 51. The target value is determined, for example, in accordance with the operation of the accelerator 16. The motion controller 73 according to the present embodiment controls the throttle actuator 52 so that the rotation speed of the engine 51 determined by the rotation speed sensor 54 becomes the target value. Accordingly, the motor 51 generates a driving force. The driving force of the engine 51 accelerates the industrial vehicle 10. Therefore, the accelerator 16 is regarded as a device that commands acceleration by the driving force of the engine 51 in response to the driver's actions.

In addition, the controller 31 is capable of receiving the rotation speed of the engine 51 detected by the rotation speed sensor 54 via the bus 40 and the motion controller 73 .

M operating mode

The controller 31 sets the operation mode M based on the state of the driver detected by the driver detection unit 36 . The operating mode M includes a normal mode M1, a limit mode M2, and an interrupt mode M3.

Normal mode M1

The normal mode M1 is a mode in which the industrial vehicle 10 moves in response to the driver. In the normal mode M1, the industrial vehicle 10 accelerates in accordance with the actuated amount of the accelerator 16. That is, the normal mode M1 is an operating mode M in which the acceleration of the industrial vehicle 10 is controlled by the operation of the accelerator 16. In the normal mode M1, the electromagnetic solenoid valve 69 is energized in response to operation of the direction commanding unit 17 . As a result, the solenoid valve 69 supplies or discharges hydraulic oil in accordance with the operation of the direction command supply unit 17 . The operating mode M when the industrial vehicle 10 is activated, that is, the initial state of the operating mode M, is the normal mode M1.

M2 limitation mode

The limit mode M2 is a mode in which the driving force of the motor 51 is limited. In the limit mode M2, the controller 31 limits the target value of the rotation speed of the engine 51 to a predetermined limit value. Accordingly, the acceleration of the industrial vehicle 10 by the accelerator 16 is limited. That is, the limit mode M2 is an operation mode M in which the acceleration of the industrial vehicle 10 by the accelerator 16 is limited. The limit value is, for example, the idle speed of the engine 51. The controller 31 transmits the target rotation speed to the movement controller 73 . When the target value, which corresponds to the actuated amount of the accelerator 16, exceeds the limit value, the controller 31 sets the rotation speed target value to the limit value. The motion controller 73 controls the motor 51 so that the rotation speed of the motor 51 becomes the target value transmitted from the controller 31.

The rotation speed target value of the engine 51 may be set to the normal mode limit value M1. In this case, the limit value in limit mode M2 is smaller than the limit value in normal mode M1. The limit mode M2 is an operation mode M in which the limit value of the rotation speed of the engine 51 is smaller than the normal mode Ml. In other words, the normal mode M1 is the operating mode M in which the limit value is larger than the limit mode M2.

In the limitation mode M2, the solenoid of the solenoid valve 69 is energized in response to the operation of the direction commanding unit 17 . As a result, the solenoid valve 69 supplies or discharges hydraulic oil in accordance with the operation of the direction command supply unit 17 .

M3 interrupt mode

The interruption mode M3 is a mode in which the transmission of driving force to the driving wheels 12, 13 by the driving force transmitting mechanism 60 is interrupted. In the interrupt mode M3, the controller 31 cuts off the power supply to the solenoid valve 69. Accordingly, the hydraulic oil supply to the clutches 64, 66 is stopped. Therefore, unlike the normal mode M1 or the limit mode M2, both clutches 64, 66 are turned off in the interrupt mode M3 independently from the direction of operation of the block 17 of the direction command. When both clutches 64, 66 are disengaged, the driving force from the engine 51 to the driving wheels 12, 13 is interrupted by the driving force transmission mechanism 60. Accordingly, in the interruption mode M3, the driving force is not transmitted from the engine 51 to the drive wheels 12, 13 even if the engine 51 is running. Thus, the interruption mode M3 is an operation mode M in which the industrial vehicle 10 cannot be accelerated by the accelerator 16. In the interruption mode M3, since the transmission of driving force by the driving force transmission mechanism 60 is interrupted, slippage does not occur.

Traffic control process

The controller 31 executes the motion control process of the industrial vehicle 10 based on the operation mode M. Now, one example of the motion control process will be described. The motion control process according to the present embodiment is repeated while the industrial vehicle 10 is driven.

Stage S1

As shown in FIG. 3, in step S1, the controller 31 determines whether the driver's state is an absence state. This determination is made based on, for example, the detection result of the driver detection unit 36 .

Stage S2

If the determination result in step S1 is positive, that is, if the driver's state is an absence state, the process of step S2 is executed. In step S2, the controller 31 executes the absence state process. The absence state process is a process of setting the operation mode M when the driver's state is the absence state. After the process is completed in the absence state, the controller 31 terminates the motion control process and restarts the motion control process from step S1.

The controller 31 according to the present embodiment executes the out-of-office state process when the out-of-office state duration T1 becomes greater than or equal to the predetermined suspension time Td. The duration T1 of the absence state is the period during which the absence state continues. In particular, the duration T1 of the absence state is a period of time during which the absence state continues from the time when the driver detection unit 36 determines the absence state. The suspension time Td can be set arbitrarily. For example, the suspension time Td is 0.5 seconds or less, preferably 0.2 seconds or less. When the absence state duration T1 is shorter than the suspension time Td, the controller 31 skips the absence state process and terminates the motion control process.

Process in absence state

An example of a process in the absence state in step S2 will now be described.

Stage S21

As shown in FIG. 4, in step S21, the controller 31 determines whether the absence state duration T1 is shorter than or equal to the predetermined absence state determination time Tx. The absence state determination time Tx may be set arbitrarily based on the expected ways of occurrence of the absence state. The absence state detection time Tx can be set arbitrarily if it is longer than the time To! pause, and is, for example, 1 second or more and 5 seconds or less, and preferably 1.5 seconds or more and 3 seconds or less. The controller 31 executing the process of step S21 corresponds to the absence state determination unit according to the present embodiment.

Step S22

In the case where the determination result in step S21 is positive, the process of step S22 is executed. The case in which the determination result in step S21 is positive corresponds to the case in which the duration T1 of the absence state is determined to be shorter than or equal to the determination time Tx of the absence state. In step S22, the controller 31 sets the operation mode M to the limitation mode M2. In this case, the controller 31 changes the operating mode M from the normal mode M1 to the limit mode M2. The controller 31 executing the process of step S22 corresponds to the restriction setting unit according to the present embodiment.

Stage S23

In the case where the result of the determination in step S21 is negative, the process of step S23 is executed. The case in which the determination result in step S21 is negative corresponds to the case in which the controller 31, which serves as the absence state determination unit, determines that the absence state duration T1 is longer than the absence state determination time Tx. In step S23, the controller 31 sets the operation mode M to the interrupt mode M3. In this case, the controller 31 changes the operation mode M from the limit mode M2 to the interrupt mode M3. The controller 31 executing the process of step S23 corresponds to the interrupt setting unit of the present embodiment.

After the process of step S22 or step S23, the controller 31 ends the absence state process.

Stage S3

If the determination result in step S1 is negative, that is, if the driver state is the presence state, the process of step S3 is executed as shown in FIG. 3. In step S3, the controller 31 determines whether the operating mode M is the normal mode M1.

If the determination result in step S3 is positive, the controller 31 terminates the motion control process while maintaining the operation mode M in the normal mode M1. That is, if the industrial vehicle 10 is running in the normal mode M1 and the driver's state is the presence state, the normal mode M1 continues to run.

Stage S4

In the case where the result of the determination in step S3 is negative, the process of step S4 is executed. The case in which the result of the determination in step S3 is negative corresponds to the case in which the operation mode M is set to the limit mode M2 or the interrupt mode M3. A situation that corresponds to such a case includes, for example, a situation in which the restriction mode M2 or the interrupt mode M3 is set by the absence state process in step S2 performed in the past and stored. In step S4, the controller 31 performs a return process. The return process is a process of setting the normal mode M1 again to the operating mode M, which has been set to the limit mode M2 or the interrupt mode M3. After the return process is completed, the controller 31 terminates the motion control process and restarts the motion control process from step S1.

Return Process

An example of the return process in step S4 will now be described.

Step S41

As shown in FIG. 5, in step S41, the controller 31 determines whether the operation mode M is set to the limit mode M2.

Step S42

If the result of the determination in step S41 is positive, that is, if the operation mode M is set to the restriction mode M2, the process of step S42 is executed. In step S42, in the case where the operation mode M is set to the restriction mode M2, the controller 31 sets the operation mode M to the normal mode M1 when the driver state determined by the driver detection unit 36 becomes the presence state. To carry out the process of step S42 in the present embodiment, it is sufficient if the driver's state is switched from the absence state to the present state, and it is not necessary to operate the accelerator pedal 16 or the direction command supply unit 17 . In this case, the controller 31 changes the operation mode M from the restriction mode M2 to the normal mode M1.

The time at which the controller 31 changes the operation mode M from the restriction mode M2 to the normal mode M1 is not limited to the time at which the driver detection unit 36 determines the presence state. For example, the controller 31 may change the operation mode M from the restriction mode M2 to the normal mode M1 when the predetermined suspension time elapses after the driver detection unit 36 determines the presence state.

Stage S43

If the result of the determination in step S41 is negative, that is, if the operation mode M is set to the interrupt mode M3, the process of step S43 is executed. In step S43, the controller 31 determines whether the predetermined cancel condition is met. The cancel condition is a condition that must be met in order to reset the operating mode M to the normal mode M1. The cancel condition includes a state in which the state of the driver is the present state and a state in which the direction determination unit 35 has detected a change in the operating position. The state in which the direction determination unit 35 has detected a change in the operating position refers to a state in which the operation direction of the direction command supply unit 17 has been changed.

In a case where the determination result in step S43 is positive, that is, in a case where the cancel condition is met, the process of step S42 is executed. The case in which the cancellation condition is met includes the case in which the state of the driver is the presence state, and the direction determination unit 35 has detected a change in the operating position. In step S42, the controller 31 sets the operation mode M to the normal mode M1. If the controller 31 executes the process of step S42 in the return process, the controller 31 changes the operation mode M from the interrupt mode M3 to the normal mode M1 in step S42.

If the result of the determination in step S43 is negative, that is, if the cancel condition is not met, the controller 31 skips step S42 and ends the return process. Therefore, the operation mode M is maintained in the interrupt mode M3.

Job

The operation of the present embodiment will now be described.

The driver may leave the driver's seat 15 while the industrial vehicle 10 is running in the normal mode M1. Such a state of absence occurs, for example, when the driver checks the surroundings. In particular, in an industrial vehicle 10 such as a forklift, the load handling device 20 or a load mounted on the load handling device 20 may block the front view from the driver's seat 15. Therefore, even in a situation in which the industrial vehicle 10 is running, the driver can get up from the driver's seat 15 to check the situation in front of the industrial vehicle 10. In this case, the driver detection unit 36 determines that the driver's state has become an absence state. Accordingly, the determination result in step S1 is affirmative, and the absence state process is performed in step S2.

At least immediately after the driver leaves his seat 15, the absence state duration T1 is shorter than or equal to the absence state determination time Tx. Accordingly, the determination result in step S21 is positive, and the operation mode M is changed to the restriction mode M2 in step S22. In particular, the operating mode M is changed from the normal mode M1 to the limitation mode M2. Thus, the rotation speed target value of the motor 51 transmitted from the controller 31 to the movement controller 73 is lower than in the normal mode M1. Accordingly, the rotation speed of the motor 51 is reduced. At this time, the transmission of driving force by the driving force transmission mechanism 60 is not interrupted. Therefore, in the limitation mode M2, the resistance of the engine 51 due to engine braking is transmitted to the driving wheels 12, 13 via the driving force transmitting mechanism 60, as in the normal mode M1.

If the driver continues to be out of place after the operation mode M is set to the restriction mode M2, the absence state duration T1 becomes longer than the absence state determination time Tx. In this case, the result of determination in step S21 is negative. Thus, the controller 31 sets the operation mode M to the interrupt mode M3 in step S23. Specifically, the controller 31 changes the operation mode M from the limit mode M2 to the interrupt mode M3. Accordingly, the controller 31 cuts off the power supply to the solenoid valve 69 and interrupts the transmission of driving force by the driving force transmission mechanism 60 . As a result, in the interruption mode M3, in contrast to the cases of the normal mode M1 or the limitation mode M2, the resistance of the engine 51 due to engine braking is not transmitted to the drive wheels 12, 13.

Advantages

The present embodiment of the invention provides the following advantages.

(1-1) The operation mode M includes a normal mode M1, a limit mode M2 which limits the driving force of the motor 51, and an interruption mode M3 which interrupts the transmission of the driving force by the driving force transmission mechanism. 60. If it is determined in step S21 that the absence state duration T1 is shorter than or equal to the absence state determination time Tx, the controller 31 executes the process of step S22 to set the operation mode M to the limitation mode M2. If it is determined in step S21 that the duration T1 of the absence state is longer than the determination time Tx of the absence state, the controller 31 executes the process of step S23 to set the operation mode M to the interruption mode M3.

In this configuration, even if the driver leaves his driver's seat 15 so that the driver's state is the absence state, the controller 31 sets the operation mode M to the restriction mode M2 if the absence state duration T1 is shorter than or equal to the absence state determination time Tx. At this time, the driving force is limited without interrupting the transmission of the driving force if the duration of the absence state is short, that is, if the duration T1 of the absence state is shorter than or equal to the determination time Tx of the absence state. If the absence state continues after the operation mode M is set to the limitation mode M2, so that the duration T1 of the absence state becomes longer than the absence state determination time Tx, the operation mode M that has been set to the limitation mode M2 is set to the interruption mode M3. . Accordingly, the drive force transmission is interrupted after the drive force is limited in the limit mode M2.

As a result, the change in operating feeling of the industrial vehicle 10 due to the driver leaving his seat 15 is reduced compared to the case in which the operating mode M, which was set to the normal mode M1, is set to the interrupt mode M3 without being set to mode M2 limitation. Thus, a reduction in driving comfort of the industrial vehicle 10 is prevented.

(1-2) In the case where the operation mode M is set to the restriction mode M2, the controller 31 executes the process of step S42 to set the operation mode M to the normal mode M1 when the driver state determined by the driver detection unit 36 enters the presence state.

With such a configuration, even in the case where the operation mode M is set to the restriction mode M2, the operation mode M returns to the normal mode M1 by a simple operation, for example, when the driver sits on the driver's seat 15 again. Therefore, it is easy to return the operating mode M from the limitation mode M2 to the normal mode M1.

(1-3) When the operation mode M is set to interrupt mode M3, the controller 31 determines whether the driver's state is the presence state in step S43, and whether the direction determination unit 35 has detected a change in direction of the direction command unit 17. When the determination result in step S43 is positive, the controller 31 executes the process of step S42 to set the operation mode M to the normal mode M1.

In this configuration, when the transmission of driving force is interrupted in the interruption mode M3, the driver needs to sit on the driver's seat 15 to return the operation mode M to the normal mode M1. In addition, in order to return the operating mode M to the normal mode M1, it is necessary to change the operating position by operating the direction commanding unit 17 . Thus, the operation mode M can be returned to the normal mode M1 not only when the driver is seated, but also when the driver indicates his intention to continue driving the industrial vehicle 10 by operating the direction command unit 17 . This reduces the likelihood that the operating mode M will return to the normal mode M1 without the driver's intention to drive the industrial vehicle 10, so that the safety of the industrial vehicle 10 is improved.

Second embodiment of the invention

Now, the industrial vehicle 10 according to the second embodiment will be described. The same reference numerals denote those components in the second embodiment that are the same as the corresponding components in the first embodiment, and their repeated descriptions may be omitted.

As shown in FIG. 6, part of the process flow of the absence state differs between the first embodiment and the second embodiment. Now, one example of the process in the absent state according to the second embodiment of the invention will be described.

Step S101

In step S101, the controller 31 determines whether the industrial vehicle 10 is in a stopped state. The controller 31 executing the process of step S101 corresponds to the stop state determination unit of the present embodiment. The controller 31 of the present embodiment determines whether the industrial vehicle 10 is in a stopped state based on the vehicle speed detected by the vehicle speed sensor 72. When the vehicle speed detected by the vehicle speed sensor 72 exceeds the predetermined speed threshold, the controller 31 determines that the industrial vehicle 10 is in motion. When the vehicle speed is lower than or equal to the threshold speed, the controller 31 determines that the industrial vehicle 10 is in a stopped state. Determining whether the industrial vehicle 10 is moving or in a stopped state is not limited to the method described above, and any method can be used. For example, the controller 31 may perform the determination based on the determination result of the rotation speed sensor 54 .

In the case where the determination result in step S101 is positive, the process of step S23 is executed. The case in which the determination result in step S101 is positive corresponds to the case in which the absence state is determined while the industrial vehicle 10 is in the stopped state. In step S23, the controller 31 sets the operation mode M to the interrupt mode M3. In this case, the controller 31 changes the operation mode M from the normal mode M1 to the interrupt mode M3. The controller 31 executing the processes of step S101 and step S23 corresponds to the forced interrupt unit of the present embodiment.

Step S102

If the result of the determination in step S101 is negative, that is, if it is determined that the industrial vehicle 10 is moving, the process of step S102 is executed. In step S102, the controller 31 determines whether the accelerator 16 is operating. Whether the accelerator 16 is being used is used as an indicator indicating whether the driver intends to drive the industrial vehicle 10.

If the result of the determination in step S102 is negative, that is, if it is determined that the accelerator 16 is not operating, the process of step S21 is executed. Thus, if the absence state is determined in a situation in which the accelerator 16 is not operating in the normal mode M1, the operation mode M is changed from the normal mode M1 to the limitation mode M2 in step S22, or the operation mode M is changed from the normal mode M1 to the interrupt mode M3 at step S23.

Step S103

If the result of the determination in step S102 is positive, that is, if the accelerator 16 is running, the process of step S103 is executed. In step S103, the controller 31 determines whether the operation mode M is the normal mode M1.

If the result of the determination in step S103 is negative, that is, if the operation mode M is the limit mode M2 or the interrupt mode M3, the process of step S21 is executed. Thus, the controller 31 sets the operation mode M to the limit mode M2 or the interrupt mode M3 according to the absence state duration T1.

Step S104

In the case where the determination result in step S103 is YES, the process of step S104 is executed. The case in which the determination result in step S103 is positive corresponds to the case in which the absence state is determined when the accelerator 16 operates in the normal mode M1. The controller 31 determines in step S104 whether the absence state duration T1 is shorter than or equal to the absence state determination time Tx.

In the case where the result of the determination in step S104 is negative, the process of step S23 is executed. The case in which the determination result in step S104 is negative is, for example, the case where the accelerator 16 has operated for a period longer than the absence state determination time Tx while the absence state continues. In this case, the controller 31 sets the operation mode M to the interrupt mode M3. Thus, it is possible to prevent the industrial vehicle 10 from running in the normal mode M1 for a long period of time while the absence state is maintained.

Step S105

In the case where the determination result in step S104 is positive, the process of step S105 is executed. In step S105, the controller 31 continues to move in the normal mode M1. In this case, the processes of step S21 and step S22 are omitted. Thus, even in the case where the absence state is determined while the accelerator 16 is operating in the normal mode M1, the controller 31 maintains the operation mode M in the normal mode M1 as long as the duration T1 of the seat absence state is less than or equal to the time Tx definition of the state of absence. The controller 31 executing the processes of steps S103 to S105 corresponds to the driving continuation unit according to the present embodiment.

Job

When the driver leaves his seat 15, even if the industrial vehicle 10 is in the stop state in the normal mode M1, the determination result in step S101 is positive, and the process of step S23 is executed. In step S23, the controller 31 sets the operation mode M to the interrupt mode M3. In this case, the controller 31 changes the operation mode M from the normal mode M1 to the interrupt mode M3. Therefore, if the driver leaves the driver's seat 15 while the industrial vehicle 10 is in the stopped state, the controller 31 lowers the driving force limitation in the limitation mode M2 and interrupts the transmission of the driving force by the driving force transmission mechanism 60 .

If the driver leaves his seat 15 while the industrial vehicle 10 is running, the determination result in step S101 is negative, and the process of step S102 is executed. In this case, if the driver controls the accelerator 16, the determination result in step S102 is positive, and the process of step S103 is executed. In this case, if the operation mode M is the normal mode Ml, the determination result in step S103 is positive, and the process of step S105 is executed. In step S105, the controller 31 continues to move in the normal mode M1 even if the driver's state is the away state.

Advantages

The second embodiment of the present invention provides the following advantages.

(2-1) The controller 31 executes the process of step S101 in which it is determined whether the industrial vehicle 10 is in the stopped state, and the process of step S23 in which the operation mode M is set to the interruption mode M3 if the absence state is determined when the industrial vehicle means 10 is in a stop state.

In this configuration, in the case where the industrial vehicle 10 is in the stop state, the operation mode M is set to the interrupt mode M3 without executing the restriction mode M2, even if the absence state duration T1 is shorter than or equal to the absence state determination time Tx. In the interruption mode M3, since the transmission of the driving force by the driving force transmission mechanism 60 is interrupted, slippage does not occur. Thus, it is possible to prevent the industrial vehicle 10 from moving in the stopped state due to slip when the driver has left the driver's seat 15.

(2-2) If the seatless state is determined when the accelerator 16 is running in the normal mode M1, the controller 31 executes the process of step S105 in which the normal mode M1 is continued.

If the accelerator 16 is activated, there is a possibility that the driver intends to continue driving the industrial vehicle 10. Thus, even if the driver's state is an away state, the driver can drive the industrial vehicle 10 in the normal mode M1 by operating the accelerator 16. Therefore, it is possible to further improve the driving comfort of the industrial vehicle 10 by reflecting the driver's intention to continue driving the industrial vehicle 10.

Modifications

The above described embodiments of the invention can be modified, as will be described below. The above described embodiments and the following modifications may be combined as long as the combined modifications remain technically compatible with each other.

The motion control processes described in the first and second embodiments are merely examples, and the present invention is not limited to them. For example, in the second embodiment, the process of step S101 may be omitted. Similarly, in the second embodiment, the processes of steps S102 to S105 may be omitted.

In the first and second embodiments, the process of step S41 may be omitted. In this case, for example, the controller 31 executes the process of step S43 regardless of whether the operation mode M is the limit mode M2 or the interrupt mode M3. Even in the case of the limit mode M2, the controller 31 sets the operation mode M to the normal mode M1 if the cancel condition is met.

In other words, initiating the change of the operation mode M from the restriction mode M2 to the normal mode M1 is not limited to the fact that the driver state determined by the driver detection unit 36 becomes the presence state.

The driver detection unit 36 may be separate from or integrated with the controller 31. The driver detection unit 36 may be a functional unit implemented by the controller 31.

In the first and second embodiments, the cancel condition need not include a state in which the driver's state is a presence state and a state in which the direction determination unit 35 has detected a change in operating position. For example, the cancel condition may be met when the cancel button provided in the industrial vehicle 10 is pressed.

In the first and second embodiments, initiating the execution of the process of step S42 that sets the operation mode M to the normal mode M1 in the case that the operation mode M is set to the restriction mode M2 is not limited to the fact that the driver state becomes the presence state, but can be changed . For example, the initiation may be the same as the cancel condition in step S43.

In the first and second embodiments, the normal mode M1 need not be explicitly defined. For example, an operation mode M other than the limit mode M2 and the interrupt mode M3 can be defined as the normal mode M1.

In the first and second embodiments, the industrial vehicle 10 may include a seat belt, a buckle connected to the seat belt, and a seat belt use sensor. The seat belt, buckle and seat belt wear sensor are not shown in the drawings. The seat belt, buckle and seat belt use sensor are attached to the driver's seat 15.

The seat belt usage sensor is configured to determine whether the driver is wearing a seat belt. For example, the seat belt usage sensor includes a switch. For example, the seat belt sensor switch turns on when the seat belt is buckled and turns off when the seat belt is not buckled. The specific configuration of the seat belt wear sensor is arbitrary and may include, for example, a pressure sensitive sensor, an optical sensor, or a camera.

The driver detection unit 36 may determine the state of the driver based on the detection result of the seat belt use sensor. For example, the driver detection unit 36 determines that the driver state is the presence state in the case where the seat belt use sensor is turned on, and determines that the driver state is the away state in the case when the seat belt use sensor is turned off.

In addition, the driver detection unit 36 may determine the state of the driver based on the determination result of the seat switch 18 and the determination result of the seat belt use sensor. For example, the driver detection unit 36 determines that the driver state is the presence state in the case where the seat belt use sensor is turned on after the seat switch 18 is turned on. This configuration facilitates the driving of the industrial vehicle 10 with proper use of the seat belt.

On the other hand, the driver detection unit 36 determines that the driver state is a seatless state in the case where the seat switch 18 is in the OFF position, in the case where the seat belt use sensor is turned off, or in the case where the seat belt use sensor is turned on earlier. which turns on the seat switch 18. The case in which the seat belt use sensor is turned on before the seat switch 18 is turned on includes, for example, the case in which the seat belt is fastened to the buckle before the driver sits on the driver's seat 15.

The information used by the driver detection unit 36 to determine the state of the driver is not limited to the result of the determination of the seat switch 18, and can be changed.

In the first and second embodiments, the industrial vehicle 10 is not limited to a forklift. For example, industrial vehicle 10 may be a tractor.

Various changes in form and detail may be made to the above examples without departing from the spirit and scope of the claims and their equivalents. The examples are given for illustration only and not for limitation. Descriptions of features in each example should be considered as applicable to similar features or aspects in other examples. Suitable results can be achieved if the sequences are performed in a different order and/or if the components in the described system, architecture, device or circuit are combined differently and/or replaced or supplemented by other components or their equivalents. The scope of the invention is not defined by the detailed description, but by the claims and their equivalents. All variations within the scope of the claims and their equivalents are included in this disclosure.

Claims (30)

1. Industrial vehicle containing: engine; driving wheel; a driving force transmission mechanism configured to transmit the engine driving force to the drive wheel; the driver's seat on which the driver sits; a driver detection unit, configured to determine a driver state from driver states including an absent state in which the driver leaves the driver's seat and a present state in which the driver sits in the driver's seat; And a controller configured to set the operation mode from the operating modes based on the state of the driver determined by the driver detection unit, wherein the operating modes include a normal mode, a limit mode that limits the driving force, and an interruption mode that interrupts the transmission of the driving force to the driving wheel by the driving force transmission mechanism, where the controller includes: an absence state determination unit, configured to determine when the driver's state is an absence state, whether the duration of the absence state during which the absence state continues is shorter than or equal to a predetermined absence state determination time; - a restriction setting unit configured to set an operation mode to a restriction mode when the absence state determination unit determines that the duration of the absence state is less than or equal to the absence state determination time; And - an interrupt setting unit configured to set the operation mode to the interrupt mode when the absence state determination unit determines that the duration of the absence state exceeds the absence state determination time. 2. The industrial vehicle according to claim 1, wherein the controller is configured to set, in the case where the operation mode is set to the restricted mode, the operation mode to the normal mode when the driver state determined by the driver detection unit becomes the presence state. 3. Industrial vehicle according to claim 1, additionally containing: a direction command supply unit that sets the direction of movement of the industrial vehicle in accordance with the direction of action; And a direction determination block that determines the direction of action, wherein the controller is configured to set, when the operation mode is set to the interrupt mode, the operation mode to the normal mode when the driver's state is the presence state, and the direction determination unit determines a change in the direction of travel. 4. Industrial vehicle according to claim 1, in which the controller includes: a stopping state determination unit, configured to determine whether the industrial vehicle is in a stopped state; And a forced interruption unit configured to set an operation mode to an interruption mode when an absence state is determined when the industrial vehicle is in a stopped state. 5. Industrial vehicle according to any one of paragraphs. 1-4, further comprising an accelerator that sets the acceleration due to the driving force in response to the actions of the driver, wherein the controller includes a driving continuation unit that is configured to continue driving in the normal mode if the absence state is determined when the accelerator is operating in the normal mode. 6. A method for controlling an industrial vehicle, comprising an engine, a drive wheel, a drive force transmission mechanism configured to transfer the engine drive force to the drive wheel, and a driver's seat on which the driver sits, in which: determining a driver state from driver states including an absent state in which the driver leaves the driver's seat and a present state in which the driver sits in the driver's seat; And setting the operation mode from the operating modes based on the determined state of the driver, wherein the operating modes include a normal mode, a limit mode that limits the driving force, and an interruption mode that interrupts the transmission of the driving force to the driving wheel by the driving force transmission mechanism, and when setting the operating mode: - determining when the driver's state is the absence state, whether the duration of the absence state during which the absence state continues is shorter than or equal to the predetermined absence state determination time; - setting the operation mode to the limited mode when it is determined that the duration of the absence state is less than or equal to the determination time of the absence state; And - setting the operation mode to the interrupt mode when it is determined that the duration of the absence state exceeds the determination time of the absence state.

Images