JPH0524685U - Mobile crane hydraulic pump controller - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] The engine stop is prevented by disengaging the clutch for driving the hydraulic pump unless the engine speed rises above the crane working speed. [Structure] A hydraulic pump 1 is driven by an engine for traveling a vehicle through a clutch 3 which is operated to be disconnected and connected by an electric signal, and engine speed control means is operated to change the engine speed from idling speed to crane operation. A switch means 8 for detecting and operating the engine speed when the engine speed is increased to a permissible rotation speed is provided on the electric circuit 7 for operating the clutch so that the switch means operates and the clutch operation switch switches the clutch connection. If selected,
The clutch is configured to be connected.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mobile crane configured so that a hydraulic pump for generating a driving hydraulic pressure of a crane mounted on a vehicle is driven by an engine for driving the vehicle via a clutch that is operated to make and disconnect by an electric signal.

[0002]

[Prior Art]

 A description will be given based on FIG. The mobile crane generates the power of the engine 1 for traveling the vehicle as driving hydraulic pressure of the mobile crane by driving a hydraulic pump 4 via a clutch 3 attached to a transmission 2 of the vehicle. The clutch 3 is operated by the electric signal output from the clutch operation switch 6, and the engine speed is controlled by the engine speed control means 5.

When the clutch operation switch 6 is selected to be in the contact state when the traveling state changes from the traveling state to the crane working state, an electric signal is output to the clutch 3 through the electric circuit 7 for operating the clutch, and the clutch 3 is in the connected state. Drives the hydraulic pump 4 via the transmission 2 and the clutch 3. The engine speed control means 5 is operated to increase the engine speed to raise the engine speed from the idling speed to the crane working speed. When the operating lever of the crane is operated, the crane is driven by the drive hydraulic pressure generated by the hydraulic pump 4. In order to increase the operating speed of the crane, the engine speed control means 5 may be further operated to increase the engine speed to increase the engine speed.

In order to finish the crane work and bring it into a traveling state, the engine speed control means 5 is operated to the lower side of the engine speed to lower the engine speed from the crane workable speed to the idling speed. When the clutch operation switch 6 is selected to be off, the output of the electric signal to the clutch 3 through the operation electric circuit 7 is cut off and the clutch 3 is disengaged, so that the driving of the hydraulic pump 4 by the power of the engine 1 is cut off. Be done. This state is the running state.

[0005]

[Problems to be solved by the device]

 In the crane work, after the clutch 3 is engaged and the hydraulic pump 4 is driven by the power of the engine 1, the engine speed control means 5 is operated to the upper and lower sides of the engine speed to idle the engine speed. The number of rotations increases from the number of rotations to the number of rotations at which the crane can work, but it is possible to operate the crane operation lever at the idling number of rotations or at an engine speed below the number of rotations at which crane work is possible, and to stop the engine. There was a problem of causing it.

[0006] When the engine is stopped, the crane suddenly stops when it is not intended to operate, which is extremely dangerous because the hanging load or the hook causes the load to shake. When the engine is further stopped, in order to restart the engine 1, first, the operation lever of the crane is returned to the neutral position, the engine speed control means 5 is returned to the idling speed position, and the clutch operation switch 6 is selected to be off. By disengaging the clutch 3, the engine starter is operated to restart the engine 1, and the clutch operating switch 6 is selected to be in the connection state to bring the clutch 3 into the connected state and the engine speed control means. A complicated operation is required, in which the engine speed must be increased to 5 to increase the engine speed from the idling speed to the crane working speed. Moreover, since the crane working speed varies depending on the load of the crane, experience was required to raise the engine speed from the idling speed to an appropriate crane working speed. An object of the present invention is to provide a hydraulic pump control device for a mobile crane that does not cause an engine stop.

[0007]

[Means for Solving the Problems] A hydraulic pump for generating a driving hydraulic pressure of a mobile crane mounted on a vehicle is connected via a clutch operated by an electric circuit for operating a clutch equipped with a clutch operation switch. In the mobile crane, the engine rotation speed control means for increasing the engine rotation speed from the idling rotation speed to the crane workable rotation speed is provided. When the engine speed is raised to the crane workable speed by operating the speed control means, this operation or switch means that operates by detecting the engine speed is connected to the electric circuit for operating the clutch. When the switch means is activated and the clutch operation switch selects the clutch connection, the clutch will be released. It was configured to be connected.

[0008]

[Action]

 When the clutch operation switch is used to select the clutch connection and the engine speed control means is operated to raise the engine speed to a crane workable speed, this operation is performed or the clutch is operated by detecting the engine speed and operating. The switch means provided in the electric circuit is actuated, the electric signal of the clutch operation switch is supplied to the clutch, and the clutch is connected.

[0009]

【Example】

 A description will be given based on FIGS. 1 and 2. As the prior art, reference numerals 1 to 7 shown in FIG. 4 and described are the same, and the description thereof will be omitted. Reference numeral 8 is a switch means. The switch means 8 is connected to the electric circuit 7 for operating the clutch, and when the engine speed control means 5 is operated to raise the engine speed to the crane workable speed, this operation or the engine speed is performed. Is detected, the operating electric circuit 7 is closed, and an electric signal from the clutch operating switch 6 for connecting the clutch 3 is supplied to the clutch 3.

When the crane operation state is changed from the traveling state, the clutch operation switch 6 is used to select the engagement of the clutch 3 and the engine speed control means 5 is operated to increase the engine speed to set the engine speed to the idling speed. When the operating speed of the crane is increased to the crane working speed, the switch means 8 detects that the engine speed control means 5 has been operated or the engine speed has risen to the crane working speed, and the operating electric The circuit 7 is closed and an electric signal from the clutch operating switch 6 is supplied to the clutch 3. When the clutch 3 is energized, the clutch 3 is brought into a connected state, so that the power of the engine 1 drives the hydraulic pump 4 via the transmission 2 and the clutch 3. When the operating lever of the crane is operated, the crane is driven by the drive hydraulic pressure generated by the hydraulic pump 4. In order to increase the operating speed of the crane, the engine speed control means 5 may be further operated to increase the engine speed to increase the engine speed.

When waiting for the operation in the crane working state, if the engine speed control means 5 is set to the position of the idling speed, the switch means 8 opens the operation electric circuit 7 and the electric power from the clutch operation switch 6 is turned on. Since the signal is no longer applied to the clutch 3, the clutch 3 is disengaged and the engine 1 does not drive the hydraulic pump 4.

[0012] In order to put the crane work into a traveling state after finishing the crane work, the clutch 3 is disengaged by setting the engine speed control means 5 to the idling speed position as in the case of waiting for the operation in the crane work status. The engine 1 does not drive the hydraulic pump 4. The selection of connection of the clutch 3 of the clutch operation switch 6 is released. This state is the running state.

Further, as shown in FIG. 3, a vehicle speed sensor 9 for detecting the vehicle speed is provided so that the electric signal from the clutch operating switch 6 is not energized to the clutch 3 when it is detected that the vehicle speed is higher than a predetermined speed. For example, even if you forget to disengage the clutch 3 when the vehicle is running, the clutch 3 is disengaged and it is safe.

[0014]

[Advantages of the Invention] In crane operation, the crane does not operate even if the operating lever of the crane is operated when the engine speed is equal to or lower than the crane operating speed, and the engine does not stop. It does not cause a very dangerous load swing of the suspended load that occurs because it suddenly stops suddenly, and it eliminates the need for a complicated operation to restart the engine. If the engine speed control means is set to the idling speed while waiting for operation in the crane working condition, the clutch will be disengaged and the engine will not drive the hydraulic pump, which will reduce noise and fuel consumption. Can be measured.

[Brief description of drawings]

FIG. 1 is an explanatory view of a hydraulic pump control device for a mobile crane according to the present invention.

FIG. 2 is an explanatory view of a hydraulic pump control device for a mobile crane according to the present invention.

FIG. 3 is an explanatory diagram of a hydraulic pump control device for a mobile crane according to another embodiment of the present invention.

FIG. 4 is an explanatory diagram of a conventional hydraulic pump control device for a mobile crane.

[Explanation of symbols]

 1 engine 2 transmission 3 clutch 4 hydraulic pump 5 engine speed control means 6 clutch operation switch 7 electric circuit for operation 8 switch means

Claims (1)

[Scope of utility model registration request] 1. A hydraulic pump for generating a driving hydraulic pressure of a mobile crane mounted on a vehicle, for driving a vehicle via a clutch that is connected / disconnected by an electric circuit for operating the clutch equipped with a clutch operation switch. In a mobile crane configured to be driven by an engine and provided with engine speed control means for increasing the engine speed from an idling speed to a crane workable speed, the engine speed control means operates the engine. When the number of rotations is increased to the number of rotations at which the crane can be operated, a switch means for detecting and operating this operation or the engine speed is provided in the electric circuit for operating the clutch. When the clutch operation switch selects the clutch connection, the clutch is configured to be connected. Hydraulic pump control apparatus for a mobile crane, characterized in that.