Work vehicle and operation method of control device thereof

Abstract

A work vehicle (100) may be provided according to the present invention, the work vehicle (100) comprising: a power source (110) for generating power; a hydrostatic transmission (120) receiving the power from the power source (110) so as to adjust and output torque; a drivetrain (130) receiving the power outputted by the hydrostatic transmission (120) so as to enable moving forward and backward; a connection device (140) receiving the power generated by the power source so as to operate a connected work machine (WM); and a control device (150) for controlling the hydrostatic transmission (120) and the connection device (140).

Description

Operation method of work vehicle and its control device

[0001] The present invention relates to a work vehicle, at least part of which is automatically controlled during the process of performing work, and an operating method of a control device for controlling the work vehicle.

[0002] Work vehicles such as tractors have implements for work.

[0003] Among the work machines, loaders, plows, and harrows are those that interact directly with the ground.

[0004] Operation of work equipment via work vehicles can be as follows. Take a loader as an example.

[0005] The work vehicle moves to the work target with the loader raised. As the work vehicle approaches the work target, it decelerates and lowers the loader.

[0006] The work vehicle tilts the bucket while lowering the loader below a certain height, or raises and lowers the loader itself appropriately so that the workpiece can be accommodated in the bucket.

[0007] If necessary, the work vehicle can move forward and backward simultaneously with the loader's elevation and bucket tilting. For example, if the soil being worked is spread out over a large area, the work vehicle may need to move forward with the loader lowered to accommodate the soil in the bucket.

[0008] Meanwhile, if the engine load increases due to the bucket containing a large amount of soil or the bucket getting caught on a rock, which impedes forward movement, the work vehicle may need to shift gears, tilt the bucket upward, or raise the loader to relieve this.

[0009] Once the bucket is loaded with the workpiece, the work vehicle raises the loader. Once the loader is raised, the work vehicle moves forward and backward to move the workpiece. To increase work efficiency, the work vehicle can simultaneously raise the loader and move forward and backward.

[0010] The work vehicle, having arrived at the moving target location, can perform a similar operation as above again to dump the accepted work target from the bucket.

[0011] To perform these tasks, the operator of the work vehicle (hereinafter referred to as the "operator") moves the work vehicle forward and backward using the forward and reverse pedals, and operates the loader using the loader operating lever and bucket tilting lever. Furthermore, the forward and reverse pedals, loader operating lever, and bucket tilting lever must be operated appropriately as needed, and simultaneous operation is frequently required to increase work efficiency.

[0012] In addition, if the work vehicle adopts a hydrostatic transmission (HST), fine control of the swash plate angle is required for proper gear shifting.

[0013] To ensure safe work, workers need to perform the above operations while also keeping an eye on the front and rear of the work vehicle.

[0014] According to this, operating a work tool rapidly accumulates worker fatigue, and if the task requires repetition, this fatigue buildup is exacerbated. If the task is performed by an inexperienced worker, work efficiency drops sharply.

[0015] When operating other types of work equipment, other than the loader mentioned above, operations with a higher degree of complexity may be required. In these cases, the aforementioned problems are exacerbated.

[0016] Ultimately, the effective operation of work vehicles depends heavily on the skill of the workers, and the demand for highly skilled workers results in increased operating costs for work vehicles.

[0017] The present invention was invented based on the recognition that there was a need to eliminate the complexity of operating a work vehicle required to operate a conventional work vehicle.

[0018] According to one embodiment of the present invention, there is provided a power source (110) that generates power; a hydrostatic transmission (120) that receives power from the power source (110) and outputs torque by controlling it; a drive system (130) that receives power output from the hydrostatic transmission (120) to enable forward and backward movement; a connecting device (140) that receives power generated by the power source and operates a connected work machine (WM); And a control device (150) for controlling the hydrostatic transmission (120) and the connecting device (140); wherein the control device (150) monitors the output of the power source (110) and the height of the lifting element in the work machine (WM), and the control device (150) switches to a work mode when the height of the lifting element is lower than a first height set in advance, and in the work mode, the control device (150) reduces the inclination of the pump-side swash plate of the hydrostatic transmission (120) when the value of the output of the power source (110) (hereinafter referred to as 'output value') is lower than a first reference value set in advance.

[0019] In the above working mode, the control device (150) may be arranged to control the connecting device (140) to raise the lifting element if the output value of the power source (110) is lower than a preset second reference value that is lower than the first reference value.

[0020] In the above working mode, the control device (150) may be arranged to control the connecting device (140) to raise the lifting element after reducing the inclination of the pump-side swash plate of the hydrostatic transmission (120) when the output value of the power source (110) is lower than or equal to the second reference value.

[0021] According to one embodiment of the present invention, there is provided a power source (110) that generates power; a hydrostatic transmission (120) that receives power from the power source (110) and outputs torque by controlling the power; a drive system (130) that enables forward and backward movement by the power output by the hydrostatic transmission (120); a connecting device (140) that receives power generated by the power source and operates a connected work machine (WM); And a control device (150) that controls the hydrostatic transmission (120) and the connecting device (140); wherein the control device (150) monitors the output of the power source (110) and the height of the lifting element in the work machine (WM), and the control device (150) switches to a work mode when the height of the lifting element is lower than a first height set in advance, and in the work mode, the control device (150) controls the connecting device (140) to raise the lifting element when the value of the output of the power source (110) (hereinafter referred to as 'output value') is lower than a second reference value set in advance. A work vehicle (100) may be provided.

[0022] The above control device (150) is provided so as to further monitor the speed of the work vehicle (100), and the control device (150) can be provided so as to switch to the work mode when the height of the lifting element is lower than a preset first height and the speed of the work vehicle (100) is lower than a preset reference speed.

[0023] In the above working mode, the control device (150) may be arranged to release the working mode when the height of the lifting element is equal to or higher than a preset second height.

[0024] The above control device (150) may be arranged to increase the inclination of the pump-side swash plate of the hydrostatic transmission (120) after releasing the above operation mode.

[0025] The above control device (150) may be arranged to reduce the inclination of the motor-side swash plate of the hydrostatic transmission (120) when the height of the lifting element is equal to or higher than a preset third height after the above work mode is released. The third height may be higher than the second height.

[0026] The output value of the power source (110) may be related to the RPM (Revolutions Per Minute) and torque of the power source (110).

[0027] According to another embodiment of the present invention, there is provided a first receiving step (S11) for receiving height information of an elevating element; a first judgment step (S12) for determining whether the height of the elevating element is equal to or lower than a first height set in advance; a third receiving step (S15) for receiving output information of a power source (110); a third judgment step (S16) for determining which area among a plurality of preset areas an output value of the power source (110) according to the output information received in the third receiving step (S15) belongs to; And a first automatic control step (S17) for controlling a hydrostatic transmission (120) to reduce the inclination of the pump-side swash plate; wherein the plurality of areas include a first area below a first reference value set in advance, and the third determination step (S16) is performed when the determination result of the first determination step (S12) is positive, and the first automatic control step (S17) is performed when the output value of the power source (110) is determined to belong to the first area as a determination result of the third determination step (S16). An operation method of a control device (150) for controlling a work vehicle (100) can be provided.

[0028] The operating method of the above control device (150) further includes a second automatic control step (S18) for controlling the connecting device (140) to raise the lifting element; wherein the plurality of regions further includes a second region that is lower than a preset second reference value that is lower than the first reference output, and the second automatic control step (S18) may be performed when the output value of the power source (110) is determined to belong to the second region as a result of the determination in the third determination step (S16).

[0029] The operation method of the control device (150) for controlling the above work vehicle (100) may be provided such that when the output value of the power source (110) is determined to belong to the second region as a result of the determination in the third determination step (S16), the second automatic control step (S18) is performed after the first automatic control step (S17) is performed.

[0030] According to another embodiment of the present invention, a first receiving step (S11) for receiving height information of an elevating element; a first judgment step (S12) for determining whether the height of the elevating element is equal to or lower than a first preset reference height; a third receiving step (S15) for receiving output information of a power source (110); a third judgment step (S16) for determining which region among a plurality of preset regions on a spectrum of an output value of the power source (110) belongs to the output value of the power source (110) according to the output information received in the third receiving step (S15); And a second automatic control step (S18) for controlling a connecting device (140) so that the lifting element rises; wherein the plurality of areas include a second area below a preset second reference value, the third determination step (S16) is performed when the determination result of the first determination step (S12) is positive, and the second automatic control step (S18) is performed when the output value of the power source (110) is determined to belong to the second area as a determination result of the third determination step (S16). An operation method of a control device (150) for controlling a work vehicle (100) may be provided.

[0031] The operating method of the above control device (150) further includes a second receiving step (S13) of receiving speed information of the work vehicle (100); and a second judgment step (S14) of judging whether the speed of the work vehicle (100) is lower than or equal to a preset reference speed; and the third judgment step (S16) may be a step performed when the judgment results of the first judgment step (S12) and the second judgment step (S14) are positive.

[0032] The operating method of the above control device (150) further includes a fourth judgment step (S22) for judging whether the height of the lifting element is equal to or greater than a preset second height; and a third automatic control step (S23) for controlling the hydrostatic transmission (120) to increase the inclination of the pump-side swash plate; and the third automatic control step (S23) may be a step performed when the judgment result of the fourth judgment step (S22) is positive.

[0033] The operating method of the above control device (150) further includes a fifth judgment step (S32) for judging whether the height of the lifting element is equal to or greater than a preset third height; and a fourth automatic control step (S33) for controlling the hydrostatic transmission (120) to reduce the inclination of the motor-side swash plate; and the fifth judgment step (S32) may be performed when the judgment result of the fourth judgment step (S22) is positive, and the fourth automatic control step (S33) may be performed when the judgment result of the fifth judgment step (S32) is positive.

[0034] The above third height may be higher than the above second height.

[0035] The output value of the power source (110) may be related to the RPM (Revolutions Per Minute) and torque of the power source (110).

[0036] According to the present invention, when operating a work machine, the necessary gear changes can be performed by operating only the operating device for operating the work machine, thereby eliminating the complexity of operation.

[0037] This reduces worker fatigue and the required skill level when performing tasks, thereby reducing the demand for highly skilled workers.

[0038] Ultimately, the present invention contributes to reducing the operating costs of work vehicles.

[0039] In addition, various additional effects may be achieved depending on the different embodiments of the present invention. These effects are introduced in the description of the respective embodiments.

[0040] Figure 1 illustrates a work vehicle connected to a work machine according to one embodiment of the present invention.

[0041] Figure 2 illustrates the configuration of a control device according to Figure 1.

[0042] Figure 3 illustrates a step in which the control device according to Figure 2 switches to the work mode and operates in the work mode.

[0043] Fig. 4 illustrates the spectrum of the output value of the driving source according to Fig. 1.

[0044] Figures 5 and 6 illustrate steps in which the control device according to Figure 2 releases the work mode and operates while the work mode is released.

[0045] A preferred embodiment according to the present invention is described with reference to the attached drawings, but for the sake of brevity, descriptions of well-known components are omitted or compressed as much as possible.

[0046] The present invention relates to a work vehicle such as a tractor, and the work vehicle (100) introduced through the present invention may generally have a configuration that a typical work vehicle has.

[0047] Therefore, the term 'work vehicle (100)' in this specification may be interpreted as a work vehicle having components necessary for the implementation (use) of the present invention, such as a power source such as an engine and a motor, a battery, a hydrostatic transmission, a drive system, a hydraulic system, a power take-off device (PTO: Power Take-Off), a work machine connecting device (hereinafter referred to as a 'connecting device'), and / or an electrical system.

[0048] Hereinafter, a work vehicle (100) according to the present invention will be described in detail, and unnecessary configurations and connection relationships will be omitted when explaining the technical idea of ​​the present invention.

[0049] <Description of the work vehicle configuration>

[0050] Figure 1 illustrates a work vehicle (100) connected to a work machine (WM) according to one embodiment of the present invention. The dotted line represents the data movement path, and the solid line represents the power movement path.

[0051] As referenced in FIG. 1, a work vehicle (100) according to one embodiment of the present invention may include a power source (110), a hydrostatic transmission (120), a drive train (130), a connecting device (140), and a control device (150).

[0052] A power source (110) is provided to generate power. The power source (110) transmits the generated power to a hydrostatic transmission (120). The power source (110) may also transmit the generated power to a connecting device (140) or a power take-off device without passing through the hydrostatic transmission (120).

[0053] The power source (110) can be provided as an engine or an electric motor.

[0054] The power source (110) can be controlled by a control device (150). This control may be direct or indirect.

[0055] The output of the power source (110) is monitored by the control device (150).

[0056] The output of the power source (110) may be related to the RPM and torque of the power source (110). For example, the output of the power source (110) may be the product of RPM (Revolutions Per Minute) and torque, the RPM of the power source (110), the torque of the power source (110), or each of the RPM and torque of the power source (110).

[0057] Monitoring of output can be done directly or indirectly. For example, if the power source (110) is an engine, the output of the power source (110) can be sensed by an ECU (Engine Control Unit), and information about the output can be provided to the control device (150). However, it is also possible for the information about the sensed output to be directly provided to the control device (150). Hereinafter, information about the output of the power source (110) provided to the control device (150) is referred to as "output information."

[0058] The output information may include the output value of the power source (110).

[0059] The output value of the power source (110) may be related to the RPM and torque of the power source (110).

[0060] The hydraulic transmission (120) is provided to receive power from the power source (110) and output torque by controlling the torque.

[0061] The hydraulic transmission (120) includes a pump and a motor.

[0062] The pump receives power from a driving source and rotates to discharge working fluid. The pump includes a pump-side swash plate for discharging working fluid by rotation.

[0063] The hydrostatic transmission (120) can adjust torque by tilting the pump-side swash plate. As the tilt of the pump-side swash plate decreases, the amount of operating fluid discharged decreases, and the torque output by the hydrostatic transmission (120) increases. As the tilt of the pump-side swash plate increases, the amount of operating fluid discharged increases, and the torque output by the hydrostatic transmission (120) decreases.

[0064] The motor rotates by receiving the operating fluid discharged from the pump. The motor may include a motor-side swash plate for rotating by receiving the operating fluid.

[0065] The hydrostatic transmission (120) can also adjust torque by tilting the motor-side swash plate. As the tilt of the motor-side swash plate decreases, the motor's rotational speed increases and the torque output by the hydrostatic transmission (120) decreases. As the tilt of the motor-side swash plate increases, the motor's rotational speed decreases and the torque output by the hydrostatic transmission (120) increases.

[0066] At least a portion of the torque output by the hydraulic transmission (120) is provided to the drive system (130).

[0067] At least a portion of the torque output by the hydraulic transmission (120) can be provided to the work machine (WM) via the connecting device (140).

[0068] The hydraulic transmission (120) is directly or indirectly controlled by a control device (150).

[0069] The drive system (130) is provided with power output from the hydraulic transmission (120) to enable forward and backward movement of the work vehicle (100).

[0070] The drivetrain (130) may include a propulsion shaft, a differential, an axle, and wheels.

[0071] The propulsion shaft may be arranged to receive power output from the transmission.

[0072] The wheels may be arranged to make contact with the ground and propel the vehicle.

[0073] The power provided to the propulsion shaft is transmitted to the wheels via the axle and differential, thereby moving the work vehicle (100) forward and backward.

[0074] This is an example, and a person skilled in the art can freely employ a drive system (130) that enables forward and backward movement of a work vehicle (100) by receiving power output from a hydrostatic transmission (120) to implement the present invention.

[0075] The drive system (130) can be controlled by the control device (150), but it can also be controlled by another control means linked to the control device (150).

[0076] The drive system (130) may be provided with a sensor for sensing the speed of the work vehicle (100). Information regarding the speed of the work vehicle (100) sensed by the sensor (hereinafter referred to as “speed information”) may be provided to the control device (150).

[0077] The connecting device (140) is provided to operate a connected work machine (WM) by receiving power generated by a power source.

[0078] The connecting device (140) may be powered directly from a power source (110) as referenced in FIG. 1, or may be powered via a power take-off device (not shown) and / or a hydraulic transmission (120).

[0079] A connecting device (140) is provided to connect a work machine (WM) to a work vehicle (100). Here, the term 'connection' should be understood to include not only a structural connection but also a functional connection, such as a connection that allows the work machine (WM) to receive power provided by a power source and operate according to the control of a control device.

[0080] The connecting device (140) is provided so that the working device (WM) can be operated under the control of the control device.

[0081] The work machine (WM) can be at least one of a loader, a plow, and a harrow.

[0082] The work machine (WM) includes a lifting element. The lifting element may refer to an element among the components of the work machine (WM) that is raised or lowered under the control of a control device. If the work machine (WM) is a loader, the lifting element may be a boom and a bucket.

[0083] The height of the lifting element is monitored by a control device (150).

[0084] Here is an example where the work machine (WM) is equipped with a loader. The loader may further be equipped with a cylinder for raising and lowering the boom or tilting the bucket. A sensor is provided in the cylinder, and the sensor can sense the advance and retreat positions of each cylinder and provide the sensed information (hereinafter referred to as “height information”) to the control device (150). The control device (150) can calculate the height of the boom and bucket, which are the lifting elements, based on the information provided by the sensor.

[0085] A person skilled in the art will be able to derive the lifting elements of various work machines (WM) based on the above-described description and appropriately install a sensor in each work machine (WM) to sense height information that can calculate the height of the derived lifting elements.

[0086] Figure 2 illustrates the configuration of a control device (150) according to Figure 1.

[0087] The control device (150) is provided to monitor the output of the power source (110), the height of the lifting element, and / or the speed of the work vehicle (100), and to control the hydrostatic transmission (120) and the connecting device (140).

[0088] The control device (150) may include a communication unit (151), a storage unit (152), a judgment unit (153), and a generation unit (154).

[0089] The communication unit (151) can receive output information of the power source (110) and height information of the lifting element. The communication unit (151) can also receive speed information from the drive system (130). Reception of the output information, height information, and / or speed information can be in real time.

[0090] The communication unit (151) may be arranged to provide output information, height information, and / or speed information to the judgment unit (153) in real time.

[0091] The communication unit (151) can transmit the control command generated by the generation unit (154) to the hydraulic pressure transmission (120) and the connecting device (140).

[0092] The communication unit (151) may be provided to enable the control device (150) to transmit and receive data necessary to control the power source (110), the hydraulic transmission (120), the drive system (130), and / or the connecting device (140). To this end, the communication unit (151) may be provided to enable CAN (Controller Area Network) communication.

[0093] The storage unit (152) can store the first height, the second height, and / or the third height, which are standards for the height of the lifting element. The storage unit (152) can store information about the spectrum (hereinafter referred to as “spectrum”) regarding the output value of the power source (110) and the first region, the second region, and the third region included therein. The storage unit (152) can store the standard speed, which is a standard for the speed of the work vehicle (100).

[0094] Information about the first height, second height, third height, spectrum, and the first, second, and third regions included therein, as well as the reference speed, are preset and stored in the storage unit (152), and can be read by the judgment unit (153) to serve as the judgment material of the judgment unit (153). Details will be described later.

[0095] The judgment unit (153) may make a judgment based on the output information, height information and / or speed information received by the communication unit (151) and the first height, second height, third height, spectrum and information about the first area, second area and third area included therein and / or the reference speed stored in the storage unit (152), and may determine the content of the control command to be generated by the generation unit (154) based on the judgment result.

[0096] The judgment unit (153) may be provided with output information, height information, and / or communication information in real time from the communication unit (151). The judgment unit (153) may be provided with the ability to monitor the output information, height information, and / or communication information.

[0097] Details on the judgment content of the judgment unit (153) and the control command accordingly will be described later.

[0098] The generation unit (154) can generate a control command for controlling the hydraulic transmission (120) and / or the work machine (WM).

[0099] The generation unit (154) can generate a control command to increase or decrease the inclination of the pump-side swash plate and / or the motor-side swash plate of the hydraulic transmission (120). The generation unit (154) can generate a control command to raise the lifting element.

[0100] The content of the control command generated by the generation unit (154) may be determined based on the judgment result of the judgment unit (153). To this end, the generation unit (154) may be arranged to receive the judgment result from the judgment unit (153). Details will be described later.

[0101] The control device (150) may be a VCU (Vehicle Control Unit) for controlling the entire vehicle.

[0102] <Description of the operation method of the control device>

[0103] FIG. 3 illustrates a step (S10) in which the control device (150) according to FIG. 2 switches to the work mode and operates in the work mode.

[0104] The operating method (S10) of the control device (150) according to one embodiment of the present invention may include a first receiving step (S11), a first judgment step (S12), a second receiving step (S13), a second judgment step (S14), a third receiving step (S15), a third judgment step (S16), a first automatic control step (S17), and a second automatic control step (S18).

[0105] The third judgment step (S16), the first automatic control step (S17), and the second automatic control step (S18) are performed in the work mode.

[0106] It is sufficient to understand that the work mode is a mode in which the control device (150) controls the hydraulic transmission (120) and / or the linkage device (140) to cause the work vehicle (100) to perform full-scale work. For example, it may be a mode in which the control device (150) controls the linkage device (140) to perform a task of lowering the bucket and interacting with the ground to receive a work object (e.g., soil) in the bucket or dumping the received work object from the bucket onto the ground.

[0107] The first receiving step (S11) is a step in which the control device (150) receives height information of the lifting element.

[0108] In the first receiving step (S11), the communication unit (151) receives height information of the lifting element. The height information can be received from a sensor and / or a connecting device (140) provided in the working machine (WM).

[0109] Since the control device (150) can be arranged to monitor the height information of the lifting element through the communication unit (151), it can be understood that the first receiving step (S11) is performed in real time.

[0110] The first judgment step (S12) is a step in which the control device (150) determines whether the height of the lifting element is lower than or equal to a preset first height.

[0111] In the first judgment step (S12), the judgment unit (153) receives the height information received by the communication unit (151) in the first receiving step (S11) from the communication unit (151).

[0112] In the first judgment step (S12), the judgment unit (153) reads the first height stored in the storage unit (152).

[0113] The first height is preferably the instantaneous height of the descending lifting element at which the work vehicle (100) is typically expected to perform work in the future. For example, if the bucket (lifting element) has been lowered to the height of the lower 1 / 3 point of the driver's seat, and the bucket is expected to continue descending to the height required for work and is not expected to rise again to perform work, the first height may be the height of the lower 1 / 3 point of the driver's seat. A person skilled in the art can predetermine the first height according to these guidelines and store it in advance in the storage unit (152).

[0114] It may be understood that the practical meaning of the judgment unit (153) performing the first judgment step (S12) is that it judges that the lifting element will continuously descend to the height required to perform the task.

[0115] The control device (150) can be switched to the working mode when the judgment result of the first judgment step (S12) is positive. That is, the control device (150) can be switched to the working mode when the height of the lifting element is lower than the preset first height.

[0116] The second receiving step (S13) is a step in which the control device (150) receives speed information of the work vehicle (100).

[0117] In the second receiving step (S13), the communication unit (151) receives speed information of the work vehicle (100) from the drive system (130).

[0118] Since the control device (150) can be arranged to monitor the speed information of the work vehicle (100) through the communication unit (151), it can be understood that the second receiving step (S13) is performed in real time.

[0119] The second judgment step (S14) is a step in which the control device (150) determines whether the speed of the work vehicle (100) is below a preset reference speed.

[0120] In the second judgment step (S14), the judgment unit (153) receives the speed information received by the communication unit (151) in the second receiving step (S13) from the communication unit (151).

[0121] In the second judgment step (S14), the judgment unit (153) reads the reference speed stored in the storage unit (152).

[0122] The reference speed is preferably the instantaneous speed of the decelerating work vehicle (100) at which the work vehicle (100) can be typically expected to perform work in the future. For example, if the speed of the work vehicle (100) has typically decreased to 3 km / h, and the work vehicle (100) is expected to continue to decelerate to a speed suitable for the work and not accelerate again to perform the work (i.e., perform pure movement), the reference speed may be 3 km / h. A person skilled in the art can set the reference speed according to these guidelines and store it in advance in the storage unit (152).

[0123] It may be understood that the practical meaning of the judgment unit (153) performing the second judgment step (S14) is that it judges that the work vehicle (100) will continue to decelerate to a speed necessary for performing the work.

[0124] The control device (150) may be switched to the work mode when the judgment result of the first judgment step (S12) as well as the judgment result of the second judgment step (S14) are positive. That is, the control device (150) may be switched to the work mode when the height of the lifting element is lower than or equal to a preset first height and the speed of the work vehicle (100) is lower than or equal to a preset reference speed.

[0125] As referenced in FIG. 3, the second judgment step (S14) is performed only when the judgment result of the first judgment step (S12) is positive, but this does not mean that the performance of the first judgment step (S12) and the second judgment step (S14) must have a temporal or logical order. That is, the first judgment step (S12) is performed only when the judgment result of the second judgment step (S14) is positive, or the first judgment step (S12) and the second judgment step (S14) are performed independently without waiting for the judgment result of each other, are also included in the scope of the present embodiment.

[0126] In the case of an embodiment in which both the first judgment step (S12) and the second judgment step (S14) are performed, it is sufficient to understand that the third judgment step (S16) is performed only when the judgment results of both steps (S12, S14) are positive.

[0127] The third receiving step (S15) is a step in which the control device (150) receives output information from the power source (110).

[0128] In the third receiving step (S15), the communication unit (151) can receive output information from the power source (110).

[0129] The control device (150) can be arranged to monitor the output information of the power source (110) through the communication unit (151), so that the third receiving step (S15) can be performed in real time.

[0130] The third judgment step (S16) is a step in which the control device (150) determines which region among multiple preset regions on the spectrum the output value of the power source (110) based on the output information received in the third receiving step (S15) belongs to.

[0131] Figure 4 illustrates the spectrum.

[0132] As referenced in Fig. 4, the spectrum can be understood as a range of possible output values ​​by the power source (110), and can be divided into a first region, a second region, and a third region. That is, the plurality of preset regions considered in the third judgment step (S16) may include the first region, the second region, and / or the third region.

[0133] The first region is the region below the first reference value. The first region may include the second region, which will be described later.

[0134] Meanwhile, as mentioned above, the output value may be related to the RPM (Revolutions Per Minute) and torque of the power source (110). Accordingly, the first reference value and the second reference value, which are values ​​on the spectrum of the output value, may also be set to be related to the RPM of the power source (110) and the torque of the power source (110), respectively.

[0135] At this time, the third judgment step (S16) can be performed with respect to the RPM and torque of the power source (110).

[0136] The first reference value may be preset to an output value of the power source (110) that is low enough to cause a stall phenomenon of the power source (110). Therefore, it is preferable that the first reference value be set to a value that is at least equal to or greater than the minimum value for preventing the stall phenomenon of the power source (110). The first reference value for the RPM of the power source (110) may be defined as a predetermined ratio that is less than 100% of the maximum RPM of the power source (110). For example, the first reference value for the RPM of the power source (110) may be set to be greater than 55% and less than or equal to 85% of the maximum RPM of the power source (110). Preferably, the first reference value for the RPM of the power source (110) may be set to 70% of the maximum RPM of the power source (110).

[0137] The first reference value for the preset torque can be defined as a predetermined function value with the RPM of the power source (110) as a parameter. In this case, the RPM of the power source (110) may be received in the third receiving step (S15).

[0138] The second zone is the zone below the second reference value. The second zone may be included in the first zone.

[0139] The second reference value may be preset as a threshold value at which a stall phenomenon of the power source (110) is expected to occur. That is, the second reference value may be preset to a value lower than the first reference value. Accordingly, a stall phenomenon may occur when the output value of the power source (110) is lower than the second reference value.

[0140] The second reference value for the RPM of the power source (110) may be defined as a predetermined ratio that is less than 100% of the maximum RPM of the power source (110). For example, the second reference value for the RPM of the power source (110) may be set within a range of more than 25% and less than or equal to 55% of the maximum RPM of the power source (110). Preferably, the second reference value for the RPM of the power source (110) may be set to 40% of the maximum RPM of the power source (110).

[0141] The second reference value for the preset torque can be defined as a predetermined function value with the RPM of the power source (110) as a parameter. In this case, the RPM of the power source (110) may be received in the third receiving step (S15).

[0142] The third zone is the zone exceeding the first reference value. When the output value of the power source (110) is in this zone, the work vehicle (100) can be considered to be operating normally.

[0143] In the third judgment step (S16), the judgment unit (153) receives the output information received by the communication unit (151) in the third reception step (S15) from the communication unit (151).

[0144] In the third judgment step (S16), the judgment unit (153) reads the spectrum and information about the first region, second region, and / or third region stored in the storage unit (152).

[0145] When the output value of the power source (110) is determined to belong to the first region as a result of the judgment in the third judgment step (S16), the first automatic control step (S17) described later can be performed.

[0146] When the output value of the power source (110) is determined to belong to the second region as a result of the judgment in the third judgment step (S16), the second automatic control step (S18) described later can be performed.

[0147] When the output value of the power source (110) is judged to belong to the third region as a result of the judgment in the third judgment step (S16), the third receiving step (S15) can be performed again.

[0148] The third judgment step (S16) can be performed when the judgment result of the first judgment step (S12) is positive.

[0149] In an embodiment in which both the first judgment step (S12) and the second judgment step (S14) described above are performed, the third judgment step (S16) can be performed only when the judgment result of the first judgment step (S12) and the judgment result of the second judgment step (S14) are both positive.

[0150] The first automatic control step (S17) is a step in which the control device (150) controls the hydrostatic transmission (120) to reduce the inclination of the pump-side swash plate. In the first automatic control step (S17), the generation unit (154) can generate a control command for the hydrostatic transmission (120) to reduce the inclination of the pump-side swash plate. At this time, the decreasing inclination of the swash plate is preset and stored in the storage unit (152), and can be read by the generation unit (154).

[0151] In the first automatic control stage (S17), the communication unit (151) can transmit a control command to the hydrostatic transmission (120) generated by the generation unit (154) to reduce the inclination of the pump-side swash plate.

[0152] The first automatic control step (S17) can be performed when the output value of the power source (110) is determined to belong to the first region as a result of the determination in the third determination step (S16).

[0153] According to this, in the work mode, the control device (150) may be arranged to reduce the inclination of the pump-side swash plate of the hydrostatic transmission (120) when the output value of the power source (110) is lower than or equal to a preset first reference value. As the first automatic control step (S17) is performed, the hydrostatic transmission (120) reduces the inclination of the pump-side swash plate. In the case where the work machine (WM) is provided as a loader, the process until the first automatic control step (S17) is performed will be described using the operation of the work vehicle (100) in the work mode as an example.

[0154] When the work vehicle (100) lowers the bucket and moves forward at a low speed to accommodate a workpiece in the bucket, the workpiece gradually accumulates in the bucket. Accordingly, a problem may arise in which the load reflected from the drive system (130) that the power source (110) must bear gradually increases. When a load exceeding a certain level is applied to the power source (110), the output of the power source (110) decreases. If the value of the decreased output falls below the first reference value and is determined to be within the first region (the third judgment step (S16)), the first automatic control step (S17) is performed, thereby reducing the inclination of the pump-side swash plate. By reducing the inclination of the pump-side swash plate, the hydrostatic transmission (120) can transmit power adjusted to a relatively higher torque than before to the drive system (130).

[0155] As a result, the power source (110) can handle the load reflected from the drive system (130). Accordingly, stalling of the power source (110) is prevented, and the work vehicle (100) can perform work smoothly.

[0156] Meanwhile, when the third judgment step (S16) is performed with respect to the RPM and torque of the power source (110), the first automatic control step (S17) can be performed when it is determined as a result of the judgment of the third judgment step (S16) that each output value with respect to the RPM and torque of the power source (110) belongs to the first region.

[0157] According to this, the control device (150) may be arranged to reduce the inclination of the pump-side swash plate of the hydraulic transmission (120) only when the RPM of the power source (110) in the working mode is lower than the first reference value and, in addition, the torque of the power source (110) decreases.

[0158] If the torque does not decrease to fall below the first reference value even when the RPM falls below the first reference value, and if it can be judged to be a normal operation of the driving source (110), the above embodiment may be more effective.

[0159] For reference, the inclination of the swash plate, which is preset and stored in the storage unit (152) to perform this first automatic control step (S17), is preferably a minimum angle that is sufficient to withstand the load reflected from the drive system (130) and does not harm the stability of the work vehicle (100).

[0160] The second automatic control stage (S18) is a stage in which the connecting device (140) is controlled so that the lifting element rises.

[0161] In the second automatic control step (S18), the generation unit (154) can generate a control command to control the connecting device (140) so that the lifting element rises. The height to which the lifting element rises is predetermined and stored in the storage unit (152), and can be read by the generation unit (154).

[0162] In the second automatic control step (S18), the communication unit (151) can transmit a control command to the connection device (140) to control the connection device (140) so that the lifting element generated by the generation unit (154) rises.

[0163] The second automatic control step (S18) may be performed when the output value of the power source (110) is determined to fall within the second region as a result of the determination in the third determination step (S16). According to this, the control device (150) may be arranged to control the connecting device (140) to raise the lifting element when the output value of the power source (110) is lower than a preset second reference value that is lower than the first reference value.

[0164] The lifting element rises as the second automatic control stage (S18) is performed. The process until the second automatic control stage (S18) is performed is explained using the operation of the work vehicle (100) in work mode as an example when the work machine (WM) is provided as a loader.

[0165] When the work vehicle (100) lowers the bucket (elevating element) to accommodate a work object and moves forward at a low speed, a problem may occur due to interference with obstacles such as rocks on the ground hindering forward movement. This problem is that an excessive load that the power source (110) cannot handle is applied to the power source (110). If a load exceeding a certain level is applied to the power source (110), the output of the power source (110) decreases. At this time, as described above, the first automatic control step (S17) is performed to increase the torque and prevent engine stall. However, if the output continues to decrease despite such measures and the output value of the power source (110) falls to the second region below the second reference value (third judgment step (S16)), the second automatic control step (S18) is performed to raise the bucket (elevating element).

[0166] As a result, the bucket is spaced apart from the obstacle to a degree that interference with the obstacle does not occur, and the work vehicle (100) can recover output without being hindered from moving forward.

[0167] Meanwhile, when the third judgment step (S16) is performed with respect to the RPM and torque of the power source (110), the second automatic control step (S18) can be performed when it is determined as a result of the judgment of the third judgment step (S16) that each output value with respect to the RPM and torque of the power source (110) belongs to the second region.

[0168] According to this, the control device (150) may be arranged to control the connecting device to raise the lifting element only when the RPM of the power source (110) in the working mode is lower than the second reference value and, in addition, the torque of the power source (110) decreases.

[0169] Even if the RPM drops and falls below the second reference value, if the torque does not drop and fall below the second reference value, the above embodiment can be more effective when it cannot be seen that a stall phenomenon is imminent in the driving source (110).

[0170] For reference, in order to perform this second automatic control step (S18), the height at which the lifting element, which is preset and stored in the storage unit (152), rises is preferably a minimum height that can be separated from obstacles on the ground to a degree that it does not interfere with obstacles, while also being easy to descend to resume work.

[0171] Considering that the second region can be included in the first region, when the output value of the power source (110) is determined to belong to the second region as a result of the determination in the third determination step (S16), both the first automatic control step (S17) and the second automatic control step (S18) can be performed. According to a preferred embodiment, in this case, the second automatic control step (S18) can be performed after the first automatic control step (S17) is performed.

[0172] Looking at the operation of the work vehicle (100) according to this, in the work mode, the control device (150) can control the connecting device (140) to raise the lifting element after reducing the inclination of the pump-side swash plate of the hydraulic transmission (120) when the output value of the power source (110) is lower than the second reference value.

[0173] According to this embodiment, even if the output value of the power source (110) drops sharply and falls below the second reference value without passing through the area between the first and second reference values, the work vehicle (100) first performs gear shifting of the hydrostatic transmission (120) before raising the elevation element. The user sets the threshold at which a stall phenomenon is expected to occur as the second reference value, but the set second reference value may be set somewhat conservatively (highly). In this case, even if the output value of the power source (110) is below the second reference value, the stall of the power source (110) can be effectively prevented by only gear shifting of the hydrostatic transmission (120). That is, even if the output value of the power source (110) is below the second reference value, by first performing gear shifting of the hydrostatic transmission (120), the work vehicle (100) can minimize unnecessary raising of the elevation element. As a result, the efficiency of the operation of the work vehicle (100) is improved.

[0174] According to the explanation so far, when an excessive load is applied to the power source (110) due to the weight of the workpiece or the presence of obstacles on the ground, the worker is no longer required to perform separate operations such as increasing torque or raising the lifting element. Therefore, the worker's convenience is improved and the dependence on the worker's skill level in performing the work can be reduced.

[0175] Among the third receiving step (S15), the third judgment step (S16), and the first automatic control step (S17) and the second automatic control step (S18), the step (S17 or S18) performed according to the judgment result of the third judgment step (S16) may be repeatedly performed until the work mode is released. That is, after the first automatic control step (S17) and the second automatic control step (S18) are completed, the third receiving step (S15) may be performed again, and the third judgment step (S16) based on the output information received in the re-performed third receiving step (S15), and the first automatic control step (S17) or the second automatic control step (S18) according to the judgment result of the third judgment step (S16) may be performed.

[0176] FIG. 5 and FIG. 6 illustrate steps (S20, S30) in which the control device (150) according to FIG. 2 releases the work mode and operates while the work mode is released.

[0177] Refer to Figure 5 to see step S20.

[0178] The operating method (S20) of the control device (150) according to one embodiment of the present invention includes a first receiving step (S21), a fourth judgment step (S22), and a third automatic control step (S23).

[0179] The first receiving step (S21) is a step in which the control device (150) receives height information of the lifting element. A detailed description is replaced with the description given above regarding the first receiving step (S11).

[0180] The fourth judgment step (S22) is a step in which the control device (150) determines whether the height of the lifting element is higher than the preset second height.

[0181] In the fourth judgment step (S22), the judgment unit (153) can receive the height information received by the communication unit (151) in the first receiving step (S21) from the communication unit (151).

[0182] In the fourth judgment step (S22), the judgment unit (153) can read the second height stored in the storage unit (152).

[0183] The second height is preferably at least the instantaneous height of the ascending lifting element at which the work vehicle (100) can normally be expected to finish work and begin moving. For example, if the bucket (elevating element) has risen to the height of the lower 1 / 3 point of the driver's seat, and the bucket is expected to continue rising to a height that does not interfere with the movement of the work vehicle (100) (e.g., a height that does not cause interference with objects on the ground during operation), and is not expected to descend again before moving to perform work, the second height may be the height of the lower 1 / 3 point of the driver's seat. A person skilled in the art can set the second height according to these guidelines and store it in advance in the storage unit (152).

[0184] If the judgment result of the fourth judgment step (S22) is positive (i.e., if the height of the lifting element is equal to or higher than the preset second height), the control device (150) can release the work mode. Since the work mode has been released, the control device (150) can be arranged not to perform the first automatic control step (S17) and the second automatic control step (S18) any longer. In other words, since the work mode has been released, the control device (150) can no longer reduce the inclination of the pump-side swash plate of the hydrostatic transmission (120) or control the connecting device (140) to raise the lifting element, even if the output value of the power source (110) belongs to the first region or the second region on the preset spectrum.

[0185] The third automatic control step (S23) may be a step in which the control device (150) controls the hydraulic pressure transmission (120) to increase the inclination of the pump-side swash plate.

[0186] In the third automatic control step (S23), the generation unit (154) can generate a control command that causes the hydrostatic transmission (120) to increase the inclination of the pump-side swash plate. The angle at which the pump-side swash plate increases the inclination is preset and stored in the storage unit (152), and can be read by the generation unit (154).

[0187] In the third automatic control stage (S23), the communication unit (151) can transmit a control command to the hydrostatic transmission (120) generated by the generation unit (154) to increase the inclination of the pump-side swash plate.

[0188] By performing the third automatic control step (S23), the hydrostatic transmission (120) increases the inclination of the pump-side swash plate. By increasing the inclination of the pump-side swash plate, the hydrostatic transmission (120) can transmit power that rotates at a relatively high speed compared to before to the drive system (130). The wheels that must rotate at a relatively high speed compared to the work mode after completing the work can receive appropriate power.

[0189] For reference, the inclination of the swash plate, which is predetermined and stored in the storage unit (152) to perform this third automatic control step (S23), is preferably the minimum angle that can provide power with sufficient torque for the work vehicle (100) to start full-scale movement while having an appropriate rotation speed for the drive system (130) of the work vehicle (100) that is about to move to the next work site after completing the work.

[0190] The third automatic control step (S23) may be performed when the judgment result of the fourth judgment step (S22) is positive. According to this, the control device (150) may be arranged to increase the inclination of the pump-side swash plate of the hydrostatic transmission (120) after releasing the work mode.

[0191] Therefore, when the worker finishes work at the work site and raises the lifting element to the second height or higher, the gear change of the hydraulic transmission (120) required for movement to the next work site, etc. can be automatically performed.

[0192] Refer to Figure 6 to see step S30.

[0193] The operating method (S30) of the control device (150) according to one embodiment of the present invention includes a first receiving step (S31), a fifth judgment step (S32), and a fourth automatic control step (S33).

[0194] The hydrostatic transmission (120) controlled by the control device (150) performing step S30 is capable of two-speed switching and is provided so that the motor-side swash plate can be tilted.

[0195] The first receiving step (S31) is a step in which the control device (150) receives height information of the lifting element. A detailed description thereof will be replaced with the description given above regarding the first receiving step (S11).

[0196] The fifth judgment step (S32) is a step in which the control device (150) determines whether the height of the lifting element is higher than the preset third height.

[0197] In the fifth judgment step (S32), the judgment unit (153) can receive height information from the communication unit (151) that the communication unit (151) received in the first receiving step (S31).

[0198] In the fifth judgment step (S32), the judgment unit (153) can read the third height stored in the storage unit (152).

[0199] The third height is preferably the height of the lifting element at which the work vehicle (100) is typically expected to begin accelerating to depart from the work site and begin moving. For example, when the bucket (lifting element) typically rises to the height of the upper 1 / 5 point of the driver's seat so that the driver's view is no longer blocked, the work vehicle (100) can be expected to begin moving and accelerate accordingly. In this case, the third height may be the height of the upper 1 / 5 point of the driver's seat. A typical technician can preset the third height according to these guidelines and store it in advance in the storage unit (152).

[0200] The fifth judgment step (S32) may be performed when the judgment result of the fourth judgment step (S22) is positive. The third height may be higher than the second height.

[0201] The fourth automatic control stage (S33) is a stage in which the control device (150) controls the hydrostatic transmission (120) to reduce the inclination of the motor-side swash plate.

[0202] In the fourth automatic control step (S33), the generation unit (154) can generate a control command that causes the hydrostatic transmission (120) to reduce the inclination of the motor-side swash plate. The angle at which the motor-side swash plate reduces the inclination is preset and stored in the storage unit (152), and can be read by the generation unit (154).

[0203] In the fourth automatic control step (S33), the communication unit (151) can transmit a control command to the hydrostatic transmission (120) generated by the generation unit (154) to reduce the inclination of the motor-side swash plate.

[0204] By performing the fourth automatic control step (S33), the hydrostatic transmission (120) reduces the inclination of the motor-side swash plate. By reducing the inclination of the motor-side swash plate, the hydrostatic transmission (120) can transmit power that rotates at a relatively high speed to the drive system (130) compared to before (and also compared to after the third automatic control step (S23) is performed). The wheels (drive system (130) that must rotate at a high speed for full-scale movement and acceleration of the work vehicle (100) can receive more appropriate power.

[0205] For reference, the inclination of the swash plate, which is predetermined and stored in the storage unit (152) to perform the fourth automatic control step (S33), is preferably the minimum angle that can provide power with sufficient torque to maintain movement while having an appropriate rotation speed to the drive system (130) of the work vehicle (100) to begin full-scale movement.

[0206] The fourth automatic control step (S33) may be performed when the judgment result of the fifth judgment step (S32) is positive. According to this, the control device (150) may be arranged to reduce the inclination of the motor-side swash plate of the hydrostatic transmission (120) when the height of the lifting element is equal to or higher than a preset third height after releasing the work mode.

[0207] Therefore, when the worker raises the lifting element to the third height or higher for full-scale movement of the work vehicle (100), the gear change of the hydrostatic transmission (120) required for full-scale movement can be performed automatically.

[0208] The above-described embodiments merely illustrate preferred examples of the present invention, and it may have various applications. Therefore, the present invention should not be construed as limited to the above-described content. Instead, the scope of the present invention should be construed within the scope of the separately described claims and their equivalents.

Claims

1. Power source (110) that generates power; A hydrostatic transmission (120) that receives power from the power source (110) and outputs torque by controlling the torque; A drive system (130) that enables forward and backward movement by receiving power output from the above-mentioned hydraulic transmission (120); A connecting device (140) that operates a connected work machine (WM) by receiving power generated by the power source; and It includes a control device (150) that controls the above-mentioned hydraulic transmission (120) and the above-mentioned connecting device (140); The above control device (150) monitors the output of the power source (110) and the height of the lifting element in the work machine (WM), The above control device (150) switches to the working mode when the height of the lifting element is lower than the preset first height, In the above working mode, the control device (150) reduces the inclination of the pump side swash plate of the hydrostatic transmission (120) when the output value (hereinafter referred to as the 'output value') of the power source (110) is lower than or equal to a preset first reference value. Work vehicle (100).

2. In paragraph 1 In the above working mode, the control device (150) controls the connecting device (140) to raise the lifting element if the output value of the power source (110) is lower than a preset second reference value that is lower than the first reference value. Work vehicle (100).

3. In paragraph 2 In the above working mode, the control device (150) controls the connecting device (140) to raise the lifting element after reducing the inclination of the pump-side swash plate of the hydrostatic transmission (120) when the output value of the power source (110) is lower than or equal to the second reference value. Work vehicle (100).

4. Power source (110) that generates power; A hydrostatic transmission (120) that receives power from the power source (110) and outputs torque by controlling the torque; A drive system (130) that enables forward and backward movement by the power output from the above-mentioned hydraulic transmission (120); A connecting device (140) that operates a connected work machine (WM) by receiving power generated by the power source; and It includes a control device (150) that controls the above-mentioned hydraulic transmission (120) and the above-mentioned connecting device (140); The above control device (150) monitors the output of the power source (110) and the height of the lifting element in the work machine (WM), The above control device (150) switches to the working mode when the height of the lifting element is lower than the preset first height, In the above working mode, the control device (150) controls the connecting device (140) to raise the lifting element if the output value (hereinafter referred to as the 'output value') of the power source (110) is lower than or equal to a preset second reference value. Work vehicle (100).

5. In any one of paragraphs 1 to 4 The above control device (150) is provided to further monitor the speed of the work vehicle (100), The above control device (150) switches to the work mode when the height of the lifting element is lower than or equal to a preset first height and the speed of the work vehicle (100) is lower than or equal to a preset reference speed. Work vehicle (100).

6. In any one of paragraphs 1 to 4 In the above working mode, the control device (150) releases the working mode when the height of the lifting element is higher than the preset second height. Work vehicle (100).

7. In paragraph 6 The above control device (150) increases the inclination of the pump side swash plate of the hydrostatic transmission (120) after releasing the above work mode. Work vehicle (100).

8. In paragraph 6 The above control device (150) reduces the inclination of the motor side swash plate of the hydrostatic transmission (120) when the height of the lifting element is equal to or higher than the preset third height after releasing the above work mode. The above third height is higher than the above second height Work vehicle (100).

9. In any one of paragraphs 1 to 3 The output of the above power source (110) is related to the RPM (Revolutions Per Minute) and torque of the above power source (110). In the above working mode, the control device (150) reduces the inclination of the pump side swash plate of the hydrostatic transmission (120) when the RPM of the power source (110) is lower than the first reference value and the torque of the power source (110) decreases. Work vehicle (100).

10. In any one of paragraphs 2 to 4 The output of the above power source (110) is related to the RPM and torque of the above power source (110), In the above working mode, the control device (150) controls the connecting device (140) to raise the lifting element when the RPM of the power source (110) is lower than the second reference value and the torque of the power source (110) decreases. Work vehicle (100).

11. First receiving step (S11) for receiving height information of the lifting element; A first judgment step (S12) for determining whether the height of the above-mentioned lifting element is lower than or equal to a preset first height; A third receiving step (S15) for receiving output information of a power source (110); A third judgment step (S16) for determining which of the plurality of preset regions the output value of the power source (110) according to the output information received in the third receiving step (S15) belongs to; and It includes a first automatic control step (S17) for controlling a hydraulic pressure transmission (120) to reduce the inclination of the pump-side swash plate; The above plurality of areas include a first area below a preset first reference value, The above third judgment step (S16) is performed when the judgment result of the above first judgment step (S12) is positive. The above first automatic control step (S17) is performed when the output value of the power source (110) is determined to belong to the first region as a result of the determination in the third determination step (S16). An operating method of a control device (150) that controls a work vehicle (100).

12. In Article 11 It further includes a second automatic control step (S18) for controlling the connecting device (140) to raise the above-mentioned lifting element; The above plurality of regions further includes a second region having a preset second reference value lower than the first reference value, The above second automatic control step (S18) is performed when the output value of the power source (110) is determined to belong to the second region as a result of the determination in the above third determination step (S16). An operating method of a control device (150) that controls a work vehicle (100).

13. In paragraph 12 When the output value of the power source (110) is determined to belong to the second region as a result of the determination in the third determination step (S16), the second automatic control step (S18) is performed after the first automatic control step (S17) is performed. An operating method of a control device (150) that controls a work vehicle (100).

14. First receiving step (S11) for receiving height information of the lifting element; A first judgment step (S12) for determining whether the height of the above-mentioned lifting element is lower than a preset first reference height; A third receiving step (S15) for receiving output information of a power source (110); A third judgment step (S16) for determining which region among a plurality of preset regions on the spectrum of the output value of the power source (110) belongs to the output value of the power source (110) according to the output information received in the third receiving step (S15); and A second automatic control step (S18) for controlling a connecting device (140) to raise the above-mentioned lifting element; The above plurality of areas include a second area below a preset second reference value, The above third judgment step (S16) is performed when the judgment result of the above first judgment step (S12) is positive. The above second automatic control step (S18) is performed when the output value of the power source (110) is determined to belong to the second region as a result of the determination in the above third determination step (S16). An operating method of a control device (150) that controls a work vehicle (100).

15. In any one of paragraphs 11 to 14 A second receiving step (S13) for receiving speed information of a work vehicle (100); and It further includes a second judgment step (S14) for judging whether the speed of the above work vehicle (100) is below a preset reference speed; The above third judgment step (S16) is performed when the judgment results of the first judgment step (S12) and the second judgment step (S14) are positive. An operating method of a control device (150) that controls a work vehicle (100).

16. In any one of paragraphs 11 to 14 A fourth judgment step (S22) for determining whether the height of the above-mentioned lifting element is equal to or greater than a preset second height; and It further includes a third automatic control step (S23) for controlling the hydraulic pressure transmission (120) to increase the inclination of the pump-side swash plate; The above third automatic control step (S23) is performed when the judgment result of the above fourth judgment step (S22) is positive. An operating method of a control device (150) that controls a work vehicle (100).

17. In Article 16 A fifth judgment step (S32) for determining whether the height of the above-mentioned lifting element is equal to or greater than a preset third height; and It further includes a fourth automatic control step (S33) for controlling the hydrostatic transmission (120) to reduce the inclination of the motor-side swash plate; The above fifth judgment step (S32) is performed when the judgment result of the above fourth judgment step (S22) is positive. The above fourth automatic control step (S33) is performed when the judgment result of the fifth judgment step (S32) is positive. The above third height is higher than the above second height An operating method of a control device (150) that controls a work vehicle (100).

18. In any one of paragraphs 11 to 13 The output value of the above power source (110) is related to the RPM (Revolutions Per Minute) and torque of the above power source (110). The above first reference value is set to be related to the RPM of the power source (110) and the torque of the power source (110), respectively. The first reference value for the RPM of the power source (110) is defined as a predetermined ratio less than 100% of the maximum RPM of the power source (110), The first reference value for the torque of the power source (110) is defined as a predetermined function value using the RPM of the power source (110) received in the third receiving step (S15) as a parameter. The above third judgment step (S16) is performed with respect to the RPM and torque of the power source (110), respectively. The first automatic control step (S17) is performed when, as a result of the judgment of the third judgment step (S16), each output value of the RPM and torque of the power source (110) is judged to belong to the first region. An operating method of a control device (150) that controls a work vehicle (100).

19. In any one of paragraphs 12 to 14 The output value of the above power source (110) is related to the RPM (Revolutions Per Minute) and torque of the above power source (110). The above second reference value is set to be related to the RPM of the power source (110) and the torque of the power source (110), respectively. The second reference value for the RPM of the power source (110) is defined as a predetermined ratio less than 100% of the maximum RPM of the power source (110). The second reference value for the torque of the power source (110) is defined as a predetermined function value using the RPM of the power source (110) received in the third receiving step (S15) as a parameter. The above third judgment step (S16) is performed with respect to the RPM and torque of the power source (110), respectively. The second automatic control step (S17) is performed when, as a result of the judgment of the third judgment step (S16), each output value of the RPM and torque of the power source (110) is judged to belong to the second region. An operating method of a control device (150) that controls a work vehicle (100).

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