JP2003214355A - Excessive rotation prevention apparatus for engine connecting type hydraulic pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of a running vehicle using an engine connecting type hydraulic pump as a drive source, in which the hydraulic pump is driven to exceed a limit revolution by action of energy upon going down a slope or other external energy, so that breakage in the hydraulic pump and malfunction of the hydraulic pump may occur, and thereby steering or braking system of the running vehicle may be out of control. <P>SOLUTION: To avoid the above problem, a disc brake device is disposed between a flywheel 1 of an engine and the hydraulic pump 2. When the rotation of the hydraulic pump exceeds the limit rotational number, control force is mechanically applied to the engine and the hydraulic pump, and thereby to lower the revolution of the hydraulic pump to a safety area. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a braking device that senses the rotation speed of a hydraulic pump using an engine speed signal and automatically applies a braking force to the hydraulic pump. It is about. 2. Description of the Related Art The operation of lowering the number of revolutions of a conventional engine-coupled hydraulic pump when it is over-rotated depends on the engine rotation resistance (engine brake). [0003] However, external energy for increasing the rotational speed of the engine-coupled hydraulic pump is required.
If was larger than the rotational resistance of the engine, a decrease in the rotational speed could not be expected. The present invention has been made to solve the above-mentioned drawbacks, and has as its object to enhance safety by installing a mechanical braking device. [0005] By mounting a braking device at the connection between the engine and the hydraulic pump, a braking force is forcibly applied to the engine and the hydraulic pump to prevent the hydraulic pump from over- rotating. [0006] Recognition of excessive rotation of the hydraulic pump depends on the driver's visibility or sensitivity of the instrument, but the present invention automatically activates the braking device when the hydraulic pump exceeds a set rotation speed. Things. FIG. 1 is an electric and hydraulic circuit diagram for operating a braking device by detecting a signal of an engine speed as an overspeed of a hydraulic pump, and FIG. 2 shows an engine and a hydraulic circuit. FIG. 4 is a cross-sectional view of a braking device mounted on a pump connection portion and operated by a command signal. In FIG. 2, the hydraulic pump 2 is normally connected to a flywheel 8 of the engine 1 via a rubber coupling 9. That is, since the rotation speeds of the engine 1 and the hydraulic pump 2 are the same, the rotation speed of the hydraulic pump 2 can be recognized by sensing the rotation speed of the engine 1. In FIG. 1, the engine 1 usually has a rotation sensor for the purpose of allowing a driver or the like to recognize the engine speed.
3 are mounted or prepared. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotation signal of a rotation sensor 3 is electrically processed, an electromagnetic switching valve 5 is operated, hydraulic pressure is supplied to a braking device, and the braking device is operated. In FIG. 1, when the rotation signal output from the rotation sensor 3 is lower than the set rotation speed of the engine, the rotation signal is cut by the low-pass filter 12 and is not transmitted to the subsequent circuits. When the engine speed exceeds a set value,
The rotation signal is input to the D / A converter 11 through the low-pass filter 12. The rotation signal is converted into a voltage by the D / A converter. When the coil of the relay unit 4 is excited, the relay contact is closed and the power supply voltage activates the electromagnetic switching valve 5. The hydraulic circuit of the electromagnetic switching valve 5 opens, and the hydraulic pressure generated by the auxiliary hydraulic pump 6 is supplied to the braking device. The hydraulic pressure supplied in FIG.
To apply a braking force for preventing the rotation of the disk rotor 10. The braking force acts on the input shaft of the hydraulic pump 2 and the flywheel 8 of the engine to reduce the rotational speed of the engine and the hydraulic pump in the over-rotation state. According to the present invention, a braking force is mechanically applied to the engine and the hydraulic pump by utilizing the hydraulic pressure, so that the rotational speed can be reliably reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system diagram showing the entire apparatus of the present invention. FIG. 2 is a sectional view of a braking device mounted on a connection between an engine and a hydraulic pump. [Description of Signs] 1 engine 2 hydraulic pump 3 rotation sensor 4 relay unit 5 electromagnetic switching valve 6 auxiliary hydraulic pump 7 piston 8 flywheel 9 rubber coupling 10 disk rotor 11 D / A converter 12 b -Pass filter-13 Hydraulic oil tank

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Claims (1)

Claims: 1. When the rotation speed of a hydraulic pump exceeds a set value, an electromagnetic switching valve is operated to supply hydraulic pressure to a braking device, so that the hydraulic pump is mounted on a connection between the engine and the hydraulic pump. A device that activates the braking device to prevent the engine and hydraulic pump from over-rotating.