Work vehicle

Patent metadata

Field	Value
Publication number	US-10669696-B2
Application number	US-201716096559-A
Country	US
Kind code	B2
Filing date	Sep 27, 2017
Priority date	Sep 28, 2016
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

In a work vehicle provided with: a working device including an arm and a bucket; a vehicle speed detection device that detects a vehicle speed; a travel drive device that outputs a travel driving force increasing in response to a decrease in the vehicle speed at a time of excavation; and a control device that controls the travel driving force by the travel drive device, the control device is characterized by including a limit control section that limits the travel driving force during a specified time which passes from when the vehicle speed detected by the vehicle speed detection device becomes a predetermined first vehicle speed threshold value or less and the work vehicle plunges into an object to be excavated until an operation of the working device is started.

First claim

The invention claimed is:

1. A work vehicle comprising:
a working device that includes an arm and a bucket;
a vehicle speed detection device that detects a vehicle speed;
a travel drive device that increases travel driving force in response to a decrease in the vehicle speed at a time of excavation; and
a control device that controls the travel driving force by the travel drive device,
wherein the control device includes:
a storage section that stores a predetermined first vehicle speed threshold value and a second vehicle speed threshold value that is higher than the predetermined first vehicle speed threshold value; and
a limit control section that limits the travel driving force during a specified time which passes from when the bucket of the work vehicle penetrates into material to be excavated until an operation of the working device is started in a case where the vehicle speed detected by the vehicle speed detection device is determined to be higher than the second vehicle speed threshold value and where the vehicle speed becomes the first vehicle speed threshold value or less from a state where the vehicle speed is higher than the second vehicle speed threshold value.

2. The work vehicle according to claim 1 , wherein the limit control section of the control device sets the specified time on the basis of a signal from a time input device.

3. The work vehicle according to claim 1 , wherein the limit control section of the control device sets a limit amount of the travel driving force on the basis of a signal from a limit input device.

4. The work vehicle according to claim 1 , wherein the limit control section of the control device limits the travel driving force in such a way that the travel driving force is increased as the vehicle speed detected by the vehicle speed detection device decreases.

5. The work vehicle according to claim 1 , wherein the limit control section of the control device sets the first vehicle speed threshold value on the basis of a signal from a vehicle speed threshold value input device.

6. The work vehicle according to claim 1 , comprising
a tilting angle detection device that detects a tilting angle of the work vehicle,
wherein the control device sets at least any one of the travel driving force to be limited, the first vehicle speed threshold value, and the specified time on the basis of the tilting angle of the work vehicle detected by the tilting angle detection device.

7. The work vehicle according to claim 1 , wherein the control device calculates a time change rate of the vehicle speed of the work vehicle and sets at least any one of the travel driving force to be limited, the first vehicle speed threshold value, and the specified time on the basis of the calculated time change rate of the vehicle speed.

8. The work vehicle according to claim 1 , comprising
a mode setting section that sets a mode to invalidate a limitation of the travel driving force during a specified time after the vehicle speed detected by the vehicle speed detection device becomes the first vehicle speed threshold value or less.

Assignees

• Hitachi Construction Mach Co

Inventors

• Takeda Kazuya
• Gotou Hiroki
• Ishida Kazuo
• Nakazawa Yoshihiko

Classifications

• E02F9/22

  Hydraulic or pneumatic drives {(for dipper or bucket arm position control E02F3/43, for blade position control for graders E02F3/844; for turntables E02F9/121; for fork-lift trucks B66F9/22)} · CPC title

• E02F9/20

  Drives; Control devices (gearings in general F16H; controlling in general G05; electric multi-motor drives H02K, H02P) · CPC title

• E02F9/2253 Primary

  Controlling the travelling speed of vehicles, e.g. adjusting travelling speed according to implement loads, control of hydrostatic transmission · CPC title

• F16H61/4008

  Control of circuit pressure · CPC title

• E02F9/2079

  Control of mechanical transmission (for hydrostatic transmission or hydraulic torque converter E02F9/2253) · CPC title