TECHNICAL FIELD

The present invention relates to a construction machine such as a hydraulic excavator.

BACKGROUND ART

Typically, when construction machines such as hydraulic excavators perform construction such as excavation of grounds which are work targets, an operator operates an operation lever to thereby drive a work implement including a bucket. Construction by construction machines is performed on the basis of design drawings. In order to perform construction in accordance with a design drawing, it is necessary to accurately know the positional relationship between a construction target surface and a work device, but it is difficult for an operator to do so visually. In view of this, a technique of displaying the positional relationship between a construction target surface and a work device as seen from a side surface of a work implement has been proposed (e.g. Patent Document 1).

Patent Document 1 discloses a display system for a work machine having a work implement to which a bucket is attached, the display system including: a generating section that uses information on the shape and dimensions of the bucket to generate drawing information for drawing an image of the bucket in a side view; and a display section that displays the image of the bucket in the side view on the basis of the drawing information generated by the generating section, and an image illustrating a cross-section of a terrain. In the display system, the information on the shape and dimensions of the bucket includes: in a side view of the bucket, a distance between a blade tip of the bucket and a bucket pin used to attach the bucket to the work implement; an angle formed between a straight line linking the blade tip and the bucket pin and a straight line indicating the bottom surface of the bucket; a position of the blade tip; a position of the bucket pin; and at least one position of an external surface of the bucket, the one position being located between a portion that couples the bucket to the work implement and the blade tip (the paragraph [0006]).

PRIOR ART DOCUMENT

Patent Document

Patent Document 1: Japanese Patent No. 6080983

SUMMARY OF THE INVENTION

Problem to be Solved by the Invention

According to the work-machine display system described in Patent Document 1, a sense of discomfort felt by an operator can be reduced by making the shape of the bucket displayed on the display section correspond to the shape of a newly attached bucket in a case where the type of the bucket attached to the work implement is changed from one to another.

Meanwhile, the work devices of a construction machine include, other than a bucket used in excavation work, a hydraulic breaker used in fracturing work, a ripper and the like (a work device having a acute tip shape), a secondary breaker used in dismantling work, and a grapple and the like (a work device that has a movable section, and perform crushing and gripping). However, the work-machine display system described in Patent Document 1 is not suited for a construction machine used also for work other than excavation work since the work-machine display system does not support work devices other than the bucket.

The present invention has been made in view of the problem explained above, and an object thereof is to provide a construction machine that can display various work devices including a bucket on a display device without causing a sense of discomfort.

Means for Solving the Problem

In order to achieve the object explained above, the present invention provides a construction machine including: a work implement having a work device attached thereto pivotably via a first coupling pin and a second coupling pin; a display controller that creates a drawing figure representing a side surface of the work device on a basis of drawing information and dimensional information on the work device, and creates a target-surface figure representing a target surface on a basis of target-surface information; and a display device that displays the drawing figure and the target-surface figure. In the construction machine, the dimensional information on the work device includes positional information on a first coupling point positioned on a central axis of the first coupling pin, a second coupling point positioned on a central axis of the second coupling pin, and a first monitor point positioned on a contour of the work device, the contour being projected onto the operation plane, and the drawing information on the work device includes image information on a first drawing figure representing at least part of the work device, the part including the first coupling point, the second coupling point and the first monitor point. Further the display controller: calculates a posture of the work implement; calculates a coordinate value of each of the first coupling point, the second coupling point and the first monitor point in a coordinate system on an image on the display device on a basis of the postural information on the work implement and the dimensional information on the work device; deforms the first drawing figure to create a first post-deformation drawing figure such that a triangle having vertexes at the first coupling point, the second coupling point and the first monitor point in the first drawing figure becomes congruent with a triangle having vertexes at the first coupling point, the second coupling point and the first monitor point in the coordinate system on the image on the display device; and arranges the first post-deformation drawing figure on a screen of the display device such that positions of the first coupling point, the second coupling point and the first monitor point in the first post-deformation drawing figure are arranged correspondingly to positions of the first coupling point, the second coupling point and the first monitor point, respectively, in the coordinate system on the image on the display device.

According to the thus-configured present invention, the first post-deformation drawing figure is created such that the triangle having vertexes at the first coupling point, the second coupling point and the first monitor point in the first drawing figure representing at least part of the work device becomes congruent with the triangle having vertexes at the first coupling point, the second coupling point and the first monitor point in the coordinate system on the image on the display device, and the first post-deformation drawing figure is arranged on the screen of the display device such that the positions of the first coupling point, the second coupling point and the first monitor point in the first post-deformation drawing figure are arranged correspondingly to the positions of the first coupling point, the second coupling point and the first monitor point, respectively, in the coordinate system on the image on the display device. Thereby, it becomes possible to display various work devices on the display device without causing a sense of discomfort.

Advantages of the Invention

A construction machine according to the present invention can display various work devices including a bucket on a display device without causing a sense of discomfort.

