Hydraulic pump malfunction diagnosing device

Patent metadata

Field	Value
Publication number	US-10132307-B2
Application number	US-201515507267-A
Country	US
Kind code	B2
Filing date	Aug 11, 2015
Priority date	Sep 2, 2014
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

A malfunction diagnosing device that includes pistons arranged in a circumferential direction and discharges oil with rotation in the circumferential direction is provided, including: a pressure sensor for detecting a pressure value of oil discharged from a hydraulic pump in rotation; a speed sensor for detecting a rotation phase of the hydraulic pump at a time when a pressure value of oil is detected by the pressure sensor; a phase calculation part; and a rendering part for rendering a model of a relationship between pressure values of oil detected by the pressure sensor and rotation phases of the hydraulic pump detected by the speed sensor and the phase calculation part to thereby obtain pulsating waveform data. This makes it possible to diagnose a malfunction of the hydraulic pump without influence of a change in a rotation speed of the hydraulic pump.

First claim

The invention claimed is:

1. A device for diagnosing a malfunction of a hydraulic pump that is provided on a hydraulic circuit having an oil tank and a hydraulic pump, and is driven by a driving source to transfer liquid from the oil tank to the hydraulic cylinder, and includes a plurality of pistons arranged in a circumferential direction and discharges liquid with rotation of the plurality of pistons in the circumferential direction, comprising:
a pressure detection section provided between the hydraulic pump and the hydraulic cylinder for detecting a pressure value of liquid discharged from the hydraulic pump in rotation;
a rotation phase detection section for detecting a rotation phase of the plurality of pistons of the hydraulic pump at the time when a pressure value of liquid is detected by the pressure detection section, the rotation phase detection section having a sensor provided to the hydraulic pump; and
a rendering section connected with the pressure detection section and the rotation phase detection section for rendering a model of a relationship between pressure values of liquid detected by the pressure detection section and rotation phases of the hydraulic pump detected by the rotation phase detection section to thereby obtain pulsating waveform data eliminating a variation in the rotation of the hydraulic pump.

2. The device for diagnosing a malfunction of a hydraulic pump according to claim 1 , wherein the rendering section performs: superimposing detections for each rotation of the hydraulic pump on one another at specific phases to thereby obtain a relationship between pressure values of liquid detected by the pressure detection section and rotation phases of the hydraulic pump detected by the rotation phase detection section; mapping the obtained relationship in a space in which a frequency is defined with reference to one rotation of the hydraulic pump; and superimposing waveforms, a number of which is a whole number times the frequency, the whole number being the number of rotations of the hydraulic pump, on one another to render the model of the relationship, thereby obtaining the pulsating waveform data.

3. The device for diagnosing a malfunction of a hydraulic pump according to claim 1 , further comprising a separation section connected with the rendering section for separating a component inherent to each piston from the pulsating waveform data rendered by the rendering section.

4. The device for diagnosing a malfunction of a hydraulic pump according to claim 3 , further comprising a determination section connected with the separation section for determining whether a feature amount related to the component inherent to each piston separated by the separation section exceeds a predetermined threshold value.

5. The device for diagnosing a malfunction of a hydraulic pump according to claim 1 , wherein the rotation phase detection section multiplies an integrated value obtained by adding up rotation speeds of the hydraulic pump by a predetermined correction factor to thereby calculate a rotation phase of the hydraulic pump at the time when a pressure value of liquid is detected by the pressure detection section.

Assignees

• Kobe Steel Ltd
• Kobelco Constr Mach Co Ltd

Inventors

• Tomochika Nobuyuki
• Yoshihara Hideki

Classifications

• G01P13/00

  Indicating or recording presence, absence, or direction, of movement (electric switches H01H; counting moving objects G06M7/00) · CPC title

• F04B51/00

  Testing machines, pumps, or pumping installations · CPC title

• F04B2205/05

  Pressure after the pump outlet · CPC title

• F04B49/103 Primary

  Responsive to speed · CPC title

• F04D15/0088

  Testing machines · CPC title