JPH02115380U - - Google Patents

Description

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a self-propelled crane equipped with a jib. Figure 2 is an explanatory diagram of a jib whose attachment method to the tip of the telescopic boom is different from that shown in Figure 1, Figure 3 is an explanatory diagram of a conventional jib drive control device, and Figure 4 is an explanatory diagram of a conventional jib drive control device. FIG. 2 is an explanatory diagram of the jib drive control device of the present invention.

Claims (1)

[Scope of utility model registration request] A drive control device for a telescopic jib that is attached to the tip of the telescoping boom of a self-propelled crane in which a telescoping boom is mounted on a swivel platform placed on a vehicle so that it can be driven up and down, the jib is composed of an outer jib section on the proximal end side and an inner jib section on the distal end side that is telescopically fitted into the outer jib section, and the proximal end of the outer jib section on the proximal end side is connected to the bottom of the distal end of the telescopic boom or the telescopic boom. The jib body is pivotally connected to the lower part of the jib mounting base attached to the tip, and the back side of the outermost jib section on the proximal end of the jib body and the top of the tip of the telescopic boom or the tip of the telescopic boom. A double-acting type luffing cylinder that is interposed between the upper part of the attached jib mounting base and raises and raises the jib main body by its contraction movement, and a double-acting type luffing cylinder that is interposed between the outer jib section and the inner jib section of the jib main body and extends the jib section. A double-acting telescoping cylinder that extends and moves the jib body by motion, and is operated by a control lever that is tiltable in the front and rear directions in the operator's cab on the swivel platform of the self-propelled crane. A four-way, three-position hydraulic switching valve is provided to control the connection relationship between the boat and the pump oil passage and the tank oil passage, and the jib body or the jib mounting base is provided with a hydraulic switching valve that controls the connection between the boat and the pump oil passage and the tank oil passage. A valve device is provided which is connected to a pair of control ports of the four-way three-position hydraulic switching valve via two extendable hydraulic hoses, which are individually connected to the oil supply chamber and each of the contraction oil supply chambers, and , the valve device is remotely controlled by an operation switch provided in the driver's cab, and connects one of the two hydraulic hoses to a refueling chamber during contraction of the hoisting cylinder, and connects the other hydraulic hose to a refueling chamber when the hoisting cylinder is extended. Switchable between a switching state in which the chambers are connected, and a switching state in which one of the two hydraulic hoses is connected to the refueling chamber when the telescopic cylinder is contracted, and the other hydraulic hose is connected to the refueling chamber when the telescopic cylinder is extended. A jib drive control device comprising: