---
publication_id: "OT-2026-000003141"
title: "Operation control device for three-joint excavator"
published_at: "2026-09-15T19:37:39.945674Z"
canonical_url: "https://opentechnical.org/p/OT-2026-000003141"
categories:
  - "tools-tooling/clamping-tools"
keywords:
  - "e02f9/20"
  - "e02f9/2025"
  - "e02f9/2025"
  - "e02f3/301"
  - "e02f3/301"
  - "e02f3/435"
---

# Operation control device for three-joint excavator

## Abstract

A speed command value X1 for a first arm 3 is decided depending on a lever input amount in the direction c, d. Assuming that the side d corresponding to move-up of the first arm is positive, the side c corresponding to move-down thereof is negative, and a speed command value resulted upon full lever operation and corresponding to a rated speed of the first arm is 1, X1 is given by -1<X1<1. A speed command value X3 for a third arm 5 is decided depending on a lever input amount in the direction e, f. Assuming that the side f corresponding to dumping of the third arm is positive, the side e corresponding to crowding thereof is negative, and a speed command value resulted upon full lever operation and corresponding to a rated speed of the third arm is 1, X3 is given by -1<X3<1. A speed command value X2 for a second arm 4 is here given by X2=K1×X1+K3×X3 on condition that the side corresponding to move-up of the second arm is positive. With such an operation control system for a 3-articulation type excavator, the excavator can be operated by operators having an ordinary skill continuously over a wide working area specific to 3-articulation type excavators with the same operating feeling as obtained with conventional 2-articulation type excavators.

## 1. Drawings

[0001] Sheet 1.

[0002] Sheet 2.

[0003] Sheet 3.

[0004] Sheet 4.

[0005] Sheet 5.

[0006] Sheet 6.

[0007] Sheet 7.

[0008] Sheet 8.

[0009] Sheet 9.

[0010] Sheet 10.