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US-12623888-B2 - Work machine

US12623888B2US 12623888 B2US12623888 B2US 12623888B2US-12623888-B2

Abstract

This work machine comprises: a plurality of booms that extend and retract with the power of an actuator; a first pin that is moved by a first spring to connect adjacent booms and is moved by power of a motor to release a connection of the adjacent booms; a second pin that is moved by a second spring to connect the boom and the actuator and is moved by power of the motor to release a connection of the boom and the actuator; and a circuit that is configured so that when the first pin is moved by the first spring or when the second pin is moved by the second spring, a current based on motor idling caused by the movement of the first pin or second pin is not generated.

Inventors

  • Tsukasa Fujimoto
  • Kenichi NAGAKANE

Assignees

  • TADANO LTD.

Dates

Publication Date
20260512
Application Date
20221004
Priority Date
20211006

Claims (6)

  1. 1 . A work machine, comprising: a plurality of booms that extend and retract by power of an actuator; a first pin that is moved by a first spring to connect adjacent booms, and is moved by power of a motor to release a connection of the adjacent booms; a second pin that is moved by a second spring to connect the boom and the actuator, and is moved by power of the motor to release a connection of the boom and the actuator; and a circuit that is configured so that when the first pin is moved by the first spring or the second pin is moved by the second spring, no current flows through the motor when the motor idles due to the movement of the first pin or the second pin.
  2. 2 . The work machine according to claim 1 , further comprising a control unit that opens a closed circuit to be formed to include the motor, by opening at least one switch provided in the circuit when the first pin is moved by the first spring or when the second pin is moved by the second spring.
  3. 3 . The work machine according to claim 2 , wherein the control unit opens a switch provided in the closed circuit to be formed, when the first pin is moved by the first spring or when the second pin is moved by the second spring.
  4. 4 . The work machine according to claim 1 , wherein the motor includes one motor, and is driven when the first pin is moved and when the second pin is moved, and stops when the first pin is moved by the first spring and when the second pin is moved by the second spring.
  5. 5 . The work machine according to claim 4 , wherein a rotation direction of the motor is switched based on switching of at least one switch provided in the circuit.
  6. 6 . The work machine according to claim 5 , wherein the circuit includes any of: a first state in which the motor rotates in a first direction and the first pin is driven; a second state in which the motor rotates in a second direction and the second pin is driven; and a third state in which the motor is stopped and the closed circuit including the motor is not formed in the circuit.

Description

CROSS REFERENCE TO PRIOR APPLICATION This application is a National Stage Patent Application of PCT International Patent Application No. PCT/JP2022/037121 (filed on Oct. 4, 2022) under 35 U.S.C. § 371, which claims priority to Japanese Patent Application No. 2021-164917 (filed on Oct. 6, 2021), which are all hereby incorporated by reference in their entirety. TECHNICAL FIELD The present invention relates to a work machine including a telescopic boom. BACKGROUND ART Patent Literature 1 discloses a mobile crane including a telescopic boom in which a plurality of booms overlap each other in a nested manner (also referred to as a telescopic manner) and a hydraulic extension/retraction cylinder that extends the telescopic boom. The telescopic boom includes a boom coupling pin that connects the booms which overlap each other in an adjacent manner. A boom that is released from connection by the boom coupling pin (hereinafter, referred to as a movable boom) can be moved with respect to another boom in a longitudinal direction (also referred to as an extending and retracting direction). The extension/retraction cylinder includes a rod member and a cylinder member. The cylinder member is connected to the movable boom via a cylinder coupling pin. In this state, when the cylinder member moves in the extending and retracting direction, the movable boom is moved together with the cylinder member, so that the telescopic boom is extended and retracted. CITATION LIST Patent Literature Patent Literature 1: JP 2012-96928 A SUMMARY OF THE INVENTION Problems to be Solved by the Invention In the crane as described above, if it takes time to move the coupling pin including the boom coupling pin and the cylinder coupling pin, the time required for extension and retraction of the telescopic boom becomes long, and the work efficiency may be deteriorated. An object of the present invention is to provide a work machine capable of improving work efficiency. Solutions to Problems One aspect of a work machine according to the present invention is a work machine including: a plurality of booms that extend and retract by power of an actuator;a first pin that is moved by a first spring to connect adjacent booms, and is moved by power of a motor to release a connection of the adjacent booms;a second pin that is moved by a second spring to connect the boom and the actuator, and is moved by power of the motor to release a connection of the boom and the actuator; anda circuit that is configured so that when the first pin is moved by the first spring or the second pin is moved by the second spring, a current based on motor idling caused by the movement of the first pin or the second pin is not generated. Effects of the Invention According to the present invention, it is possible to provide a work machine capable of improving work efficiency. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view of a mobile crane according to an embodiment. FIGS. 2A to 2E are schematic views for describing a structure and an extension and retraction operation of a telescopic boom. FIG. 3 is a front view of a pin movement module in an extended state and in a state of holding boom coupling pins. FIG. 4 is a front view of the pin movement module in which a boom coupling mechanism is in a retracted state and a cylinder coupling mechanism is in an extended state. FIG. 5 is a front view of the pin movement module in which the boom coupling mechanism is in an extended state and the cylinder coupling mechanism is in a retracted state. FIG. 6A is a circuit diagram of an electric circuit in a first driving state. FIG. 6B is a circuit diagram of an electric circuit in a second driving state. FIG. 6C is a circuit diagram of an electric circuit in a first release state. FIG. 6D is a circuit diagram of an electric circuit in a second release state. FIG. 6E is a circuit diagram of an electric circuit in a braking state. FIG. 7A is a schematic view for describing an operation of the cylinder coupling mechanism. FIG. 7B is a schematic view for describing the operation of the cylinder coupling mechanism. FIG. 7C is a schematic view for describing the operation of the cylinder coupling mechanism. FIG. 8A is a schematic view for describing an operation of the boom coupling mechanism. FIG. 8B is a schematic view for describing the operation of the boom coupling mechanism. FIG. 8C is a schematic view for describing the operation of the boom coupling mechanism. DESCRIPTION OF EMBODIMENTS Hereinafter, an example of embodiments according to the present invention will be described in detail based on the drawings. Note that a crane according to the embodiment described below is an example of a work machine according to the present invention, and the present invention is not limited to the embodiments described below. EMBODIMENT FIG. 1 is a schematic view of a mobile crane 1 (in the illustrated case, rough terrain crane) according to the present embodiment. The mobile crane 1 corresponds