US-12623890-B2 - Loading type truck crane

US12623890B2US 12623890 B2US12623890 B2US 12623890B2US-12623890-B2

Abstract

There is provided a loading type truck crane that includes an outrigger device including a right outrigger and a left outrigger that are mounted on a vehicle and are capable of extending and retracting in a vehicle width direction of the vehicle, and a crane device that includes a turnable boom and is mounted on the vehicle. A control device that is provided in the truck crane calculates a critical working radius of the crane device on a basis of a ground-contact reaction force of the outrigger device, and implements safety control related to at least one of a lowering operation and an extension operation of the boom by the crane device on a basis of the calculated critical working radius.

Inventors

Tomokazu Goto

Assignees

TADANO LTD.

Dates

Publication Date: 20260512
Application Date: 20220818
Priority Date: 20210819

Claims (6)

1 . A loading type truck crane comprising: an outrigger device including a right outrigger and a left outrigger that are mounted on a vehicle and are capable of extending and retracting in a vehicle width direction of the vehicle; a crane device that includes a turnable boom and is mounted on the vehicle; and a control device that calculates a critical working radius of the crane device on a basis of a ground-contact reaction force of the outrigger device, and implements safety control related to at least one of a lowering operation and an extension operation of the boom by the crane device on a basis of the calculated critical working radius, wherein the safety control includes regulation control for regulating a lowering operation and an extension operation of the crane device.
2 . The loading type truck crane according to claim 1 , wherein the safety control further includes notification control for notifying a user of the crane device of information.
3 . The loading type truck crane according to claim 2 , wherein the critical working radius includes a first critical working radius and a second critical working radius smaller than the first critical working radius, and wherein the control device implements the notification control on a basis of the second critical working radius, and implements the regulation control on a basis of the first critical working radius.
4 . The loading type truck crane according to claim 1 , wherein the control device: calculates a crane strength performance radius from crane strength performance used to determine a rated load of the loading type truck crane; compares the calculated crane strength performance radius with the critical working radius; implements the safety control based on the critical working radius when the critical working radius is smaller than the crane strength performance radius; and implements the safety control based on the crane strength performance radius when the crane strength performance radius is smaller than the critical working radius.
5 . The loading type truck crane according to claim 1 , further comprising: a display that is connected to the control device and displays a state of the loading type truck crane, wherein the control device displays the critical working radius on the display.
6 . The loading type truck crane according to claim 1 , wherein the regulation control regulates the lowering operation and the extension operation of the crane device by performing speed regulation or disabling the lowering operation in response to the lowering operation approaching the critical working radius.

Description

CROSS REFERENCE TO PRIOR APPLICATION This application is a National Stage Patent Application of PCT International Patent Application No. PCT/JP2022/031275 (filed on Aug. 18, 2022) under 35 U.S.C. § 371, which claims priority to Japanese Patent Application No. 2021-133758 (filed on Aug. 19, 2021), which are all hereby incorporated by reference in their entirety. TECHNICAL FIELD The present invention relates to a loading type truck crane. More specifically, the present invention relates to a loading type truck crane having an overturning prevention function. BACKGROUND ART A loading type truck crane often includes a crane device and an outrigger device between an operator cab and a cargo bed. When performing the crane operation, the user of the loading type truck crane performs the crane operation after lifting the vehicle body by the hydraulic jacks provided at the left and right outer end portions of the outrigger device. That is, the boom of the crane device is swung, expanded, retracted, or raised and lowered to lift the cargo, and the cargo is transported. Patent Literature 1 discloses an overturning prevention device for preventing an overturning accident of the loading type truck crane. In the overturning prevention device, according to the magnitude of the reaction force value of the reaction force detector attached to the outrigger, the amount of movement of the spool of the control valve is reduced when the reaction force value is small, as compared with when the reaction force value is large, and the crane speed is decelerated steplessly. Patent Literature 1 describes that with this configuration, the crane can be decelerated or stopped according to the reaction force value without depending on the operation by the user of the loading type truck crane, and the overturning of the loading type truck crane can be reliably prevented. CITATION LIST Patent Literature Patent Literature 1: JP 2011-37565 A SUMMARY OF THE INVENTION Problems to be Solved by the Invention Since the crane device of the loading type truck crane can perform operations such as turning, expansion and retraction, and derricking of the boom, there are a wide variety of postures that the boom can take. For example, when the posture of the boom with respect to derricking is relatively close to horizontal, when the boom is extended, the reaction force value of the outrigger located on the opposite side of the boom rapidly decreases. On the other hand, when the posture of the boom with respect to the derricking is relatively close to the vertical, the decrease in the reaction force value of the outrigger is moderate even if the boom is extended. In the invention of Patent Literature 1, the crane speed is reduced in a predetermined state to prevent the overturning of the loading type truck crane. However, since the degree of decrease in the reaction force value varies depending on the posture of the boom, when the operation of the boom is decelerated on the safe side, the operation of the boom is rapidly regulated against the operation by the user. As a result, there is a problem that efficiency of crane operation is unnecessarily deteriorated. In view of the above circumstances, an object of the present invention is to provide a loading type truck crane capable of suppressing overturning of the loading type truck crane without impairing efficiency of crane operation. Solutions to Problems An aspect of a loading type truck crane of the present invention includes an outrigger device including a right outrigger and a left outrigger that are mounted on a vehicle and are capable of extending and retracting in a vehicle width direction of the vehicle, a crane device that includes a turnable boom and is mounted on the vehicle, and a control device that calculates a critical working radius of the crane device on a basis of a ground-contact reaction force of the outrigger device, and implements safety control related to at least one of a lowering operation and an extension operation of the boom by the crane device on a basis of the calculated critical working radius. Effects of the Invention According to the present invention, it is possible to provide a loading type truck crane capable of suppressing overturning of the loading type truck crane without impairing efficiency of crane operation. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a control flowchart based on a critical working radius of a loading type truck crane according to the first embodiment of the present invention. FIG. 2 is a side view of the loading type truck crane. FIG. 3 is a hydraulic circuit diagram of the loading type truck crane. FIG. 4 is a control circuit diagram of the loading type truck crane. FIG. 5 is a flow diagram of acquisition of a current parameter before calculation of a critical working radius of the loading type truck crane. FIG. 6 is a schematic diagram when a boom of the loading type truck crane has a derricking angle of zero. FIG. 7 is a schematic diagram when a