Working vehicle with a working implement displaceable by a hydraulic actuator

• US 20020104430A1
• Filed: 02/28/2001
• Published: 08/08/2002
• Est. Priority Date: 02/02/2001
• Status: Active Grant

• Current Assignee: Kubota Corporation
• Original Assignee: Kubota Corporation
• Inventors: Inamori, Akio, Yamaguchi, Tetsuo
• Granted Patent: US 6,612,218 B2
• Time in Patent Office: Days
• US Class Current: 91/358R
• CPC Class Codes: A01B 63/114 to achieve a constant working depth
• CPC Class Codes: F15B 11/20 controlling several interacting or sequentially-operating members
• CPC Class Codes: F15B 21/082 with different modes

Abstract

A working vehicle comprises a working implement (20) supported by the working vehicle to be displaceable by a hydraulic actuator (1), and a controller (16) for generating a control output signal for controlling a position of the working implement in response to a control input signal, with reference to predetermined control characteristics. The control characteristics include at least a first control characteristic (Qs′) and a second control characteristic (Qs″) different from each other. The controller refers to the second control characteristic for generating the control output signal when the control input signal results from a variation in a set signal from a setter (15; 17S) for setting a target level of the working implement, and refers to the second control characteristic for generating the control output signal when the control input signal results from a variation in a detection signal from a displacement detecting sensor for detecting a displacement of the working implement.

Claims

1. A working vehicle comprising:

a working implement supported by the working vehicle to be displaceable by a hydraulic actuator; and

a controller for generating a control output signal for controlling a position of said working implement in response to a control input signal, with reference to predetermined control characteristics;

wherein said control characteristics include at least a first control characteristic and a second control characteristic different from each other, said controller selecting a control characteristic to refer to, according to a type of said control input signal.

2. A working vehicle as defined in claim 1, wherein said second control characteristic has a higher time-dependent rate of increase in a quantity of pressure oil supplied to said hydraulic actuator than said first control characteristic.

3. A working vehicle as defined in claim 2, wherein said controller refers to said second control characteristic for generating said control output signal when said control input signal results from a variation in a set signal from a setter for setting a target level of said working implement, and refers to said second control characteristic for generating said control output signal when said control input signal results from a variation in a detection signal from a displacement detecting sensor for detecting a displacement of said working implement.

4. A working vehicle as defined in claim 3, wherein said setter for setting a target level of said working implement is a position setter for setting a height of said working implement relative to the working vehicle.

5. A working vehicle as defined in claim 3, wherein said setter for setting a target level of said working implement is an upper limit setter for setting an upper limit position of said working implement relative to the working vehicle, said working implement being forcibly displaced to said upper limit position set by said upper limit setter.

6. A working vehicle as defined in claim 2, wherein said controller refers to said second control characteristic for generating said control output signal when said control input signal results from a variation in a set signal from a draft setter for setting a reference operational load for said working implement, and refers also to said second control characteristic for generating said control output signal when said control input signal results from a variation in a detection signal from a load detecting sensor for detecting an actual operational load acting on said working implement.

7. A working vehicle as defined in claim 2, wherein said controller refers to said second control characteristic for generating said control output signal when said control input signal results from a variation in a set signal from a setter for setting a target position of said working implement, refers to said second control characteristic for generating said control output signal when said control input signal results from a variation in a detection signal from a displacement detecting sensor for detecting a displacement of said working implement, refers to said second control characteristic for generating said control output signal when said control input signal results from a variation in a set signal from a draft setter for setting a reference operational load for said working implement, and refers also to said second control characteristic for generating said control output signal when said control input signal results from a variation in a detection signal from a load detecting sensor for detecting an actual operational load acting on said working implement.

8. A working vehicle comprising:

a working implement supported by the working vehicle to be displaceable by a hydraulic actuator; and

a controller for generating a control output signal for controlling a position of said working implement in response to a control input signal, with reference to predetermined control characteristics;

wherein said control characteristics include a first control characteristic having a predetermined time-dependent rate of increase in a quantity of pressure oil supplied to said hydraulic actuator, a second control characteristic having a higher time-dependent rate of increase than said first control characteristic, and a deflection control characteristic set to increase the quantity of pressure oil supplied to said hydraulic actuator with a deviation between a set signal from a setter for setting a target position of said working implement and a detection signal from a position detecting sensor for detecting a position of said working implement; and

wherein said controller selects one of said first and second control characteristics according to a type of said control input signal, compares said one of said first and second control characteristics selected with said deviation control characteristic, and generates said control output signal with reference to a value for supplying a smaller quantity of pressure oil to said hydraulic actuator.