Hydraulic excavator attachment control device

Abstract

Disclosed is a hydraulic excavator attachment control device comprising a hydraulic circuit that is provided with a hydraulic pump (3); a plurality of actuators including the actuator for a breaker (110) which is an attachment; and a plurality of flow control valves including a flow control valve (B4) for the attachment, this flow control valve (B4) being switched by means of operating pilot pressure from an operating pedal device (7), and supplying discharged oil from the hydraulic pump (3) to the actuator for the attachment. When the operating pedal device (7) is operated, with an attachment mode not selected by an attachment selecting device (20), the action of the actuator for the attachment is restricted. Due to the above, if an operator forgets to switch from a normal mode to the attachment mode, resulting in the attachment being operated, it is possible to prevent the failure and life reduction of the attachment and other hydraulic devices.

Description

technical field [0001] The present invention relates to an attachment control device for a hydraulic excavator, and more particularly to an attachment control device for a hydraulic excavator having a hydraulic circuit for attachments mounted on a front working machine of the hydraulic excavator. Background technique [0002] In a hydraulic excavator as a construction machine, in addition to installing a highly versatile bucket to carry out excavation operations, etc., the front end of the front working machine can also be equipped with auxiliary equipment such as a breaker or a crusher. Perform various tasks instead of buckets. [0003] Among the attachments installed on the front working machine, the specifications such as the pressure and flow rate of the pressure oil are determined according to the type, and it is necessary to change the settings of the hydraulic circuit and the like according to the type of attachment installed on the front working machine. [0004] As...

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Problems solved by technology

[0009] However, in the prior art described above, the problem that the operator forgets to switch from the normal mode to the accessory mode is not considered, and the accessory is operated in the normal mode that is not set according to the type of accessory. As a result, the auxiliary equipment will be used in a state exceeding the specification, and there is a possibility that the auxiliary equipment and other hydraulic machinery may fail or the life may be shortened.

In addition, since foreign matter such as dust may be mixed into the return oil, it is preferable to allow the return oil to flow directly back to the oil tank without passing through the control valve for auxiliary equipment such as a rock crusher. When the auxiliary equipment such as the rock crusher is operated in the normal mode of flowing back into the oil tank, there is a possibility that the valve column is stuck (spool stick) due to dust, etc., and the state exceeds the specification Similarly, when using auxiliary equipment, there is a possibility that the auxiliary equipment and other hydraulic equipment may fail or reduce their life.

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