# US 2014/0151074 A1 · Blade control system and construction machine

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- Number: US 2014/0151074 A1
- Document ID: US20140151074A1
- Status: Published application
- Kind: A1
- Application number: 14/176,355
- Filed: 2014-02-10
- Published: 2014-06-05
- Earliest claimed: 2011-09-30
- Assignees: Komatsu Ltd.
- Applicants: Komatsu Ltd.
- Inventors: Kazuhiko HAYASHI; Kenji OKAMOTO; Kenjiro SHIMADA
- Web page: https://patentgrep.com/patent/US20140151074A1

## CPC

- E02F 3/844: {for positioning the blade, e.g. hydraulically}
- E02F 3/7609: {Scraper blade mounted forwardly of the tractor on a pair of pivoting arms which are linked to the sides of the tractor, e.g. bulldozers}
- E02F 3/7618: {with the scraper blade adjustable relative to the pivoting arms about a horizontal axis}
- E02F 3/845: {using mechanical sensors to determine the blade position, e.g. inclinometers, gyroscopes, pendulums}
- E02F: DREDGING; SOIL-SHIFTING (winning peat E21C49/00)

## Abstract

A blade control system includes an angle obtaining part, an open ratio setting part and a lift cylinder controlling part. The angle obtaining part is configured to obtain an angle of a lift frame with respect to a designed surface. The open ratio setting part is configured to set an open ratio based on the angle. The lift cylinder controlling part is configured to open a proportional control valve at the open ratio for elevating the blade when a distance between the designed surface and an edge of a blade is determined to be less than or equal to a threshold.

## Claims

### Claim 1

A blade control system comprising:
a lift frame vertically pivotably attached to a vehicle body;
a blade supported by a tip of the lift frame, the blade extending in a right-and-left direction of the vehicle body;
a lift cylinder configured to vertically pivot the lift frame;
a proportional control valve connected to the lift cylinder;
an angle obtaining part configured to obtain an angle of the lift frame with respect to a designed surface in a side view of the vehicle body, the designed surface formed as a three-dimensionally designed landform indicating a target contour of an object for dozing;
an open ratio setting part configured to set an open ratio of the proportional control valve based on the angle;
a distance calculating part configured to calculate a distance between the designed surface and a cutting edge of the blade;
a determining part configured to determine whether or not the distance between the designed surface and the cutting edge of the blade is less than or equal to a threshold; and
a lift cylinder controlling part configured to open the proportional control valve at the open ratio set by the open ratio setting part for elevating the blade when the determining part determines that the distance between the designed surface and the cutting edge of the blade is less than or equal to the threshold.

### Claim 2 (depends on 1)

The blade control system according to claim 1, wherein
the open ratio setting part is configured to increase the open ratio of the proportional control valve in proportion to magnitude of the angle of the lift frame with respect to the designed surface.

### Claim 3 (depends on 2)

The blade control system according to claim 2, wherein
the open ratio setting part is configured to fix the open ratio of the proportional control valve to be a maximum value when the angle of the lift frame with respect to the designed surface is greater than or equal to a predetermined value.

### Claim 4 (depends on 1)

The blade control system according to claim 1, wherein
the lift cylinder controlling part is configured to prevent elevation of the blade when the lift frame is positioned higher than a predetermined position.

### Claim 5 (depends on 1)

The blade control system according to claim 1, further comprising:
a blade load obtaining part configured to obtain a load acting on the blade; and
a storage part configured to store a target load preliminarily set, wherein
the lift cylinder controlling part is configured to control the open ratio of the proportional control valve for allowing the load to get closer to the target load when the determining part determines that the distance between the designed surface and the cutting edge of the blade is greater than the threshold.

### Claim 6 (depends on 1)

A construction machine, comprising:
a vehicle body; and
the blade control system according to claim 1.

### Claim 7 (depends on 6)

The construction machine according to claim 6, further comprising:
a drive unit including a pair of tracks attached to the vehicle body.