PATENT CLAIM ANALYSIS

Application Number: 15754676
Application Type: Utility
Filing Date: 2018-02
Publication Date: 2018-08
Patent Classification: ["060", "468000"]

Abstract:
A hydraulic working machine is provided that uses a variable displacement pump and open center type flow rate control valve for a controlling a hydraulic actuator, and has a negative control throttle disposed in a center bypass oil passage to generate a negative control pressure. A hydraulic pump control system performs virtual bleed-off control for reducing the bleed-off flow rate of the center bypass oil passage, and can operate the hydraulic actuator with the same performance as an open center control. The control system includes a bypass cut valve disposed upstream from the negative control throttle to reduce flow through the center bypass oil passages, and a negative control pressure output valve that outputs a virtual negative control pressure. The control system is configured to reduce the bleed-off flow rate by operating the bypass cut valve when virtual bleed-off control is performed, and to reduce the pump flow rate by the bleed-off reduction flow rate.

Claim (Index 1):
A hydraulic pump control system of a hydraulic working machine comprising:\n a variable displacement hydraulic pump having a variable displacement means for varying the hydraulic pump displacement; a hydraulic actuator to which a pressure oil is supplied from the hydraulic pump; an open center type flow rate control valve that has a bleed-off opening configured to allow a pump flow rate to flow to an oil tank at a neutral position, and controls the supply flow rate from the hydraulic pump to the hydraulic actuator based on the manipulation of a hydraulic actuator manipulation tool; a center bypass oil passage that extends from the hydraulic pump to the oil tank via the bleed-off opening of the flow rate control valve; and a negative control throttle that is disposed in the center bypass oil passage downstream from the bleed-off opening to generate a negative control pressure, wherein the hydraulic pump control system comprises; a bypass cut valve that is disposed upstream from the negative control throttle to reduce flow through the center bypass oil passage when operated; a negative control pressure output valve that is operated to output a virtual negative control pressure; a control means that controls the operation of the bypass cut valve and the negative control pressure output valve; and a negative control pressure introduction means that selectively guides one of the negative control pressure generated by the negative control throttle and the virtual negative control pressure that is output from the negative control pressure output valve to the variable displacement means of the hydraulic pump.

Metadata:
- Claim Count in Document: 13.0
- Percentile: 88.0
- Lexical Diversity: 2.4697
- Patent Class: 60.0
- Transitional Phrase Type: open
- Component Type: 1
- Foreign Priority: True
- Related Applications: ['15413819', '15726840', '14217678', '14217721', '15556016']

Analysis Scores:
- 35 USC 101 Eligibility (BERT): 0.7202329473368917
- 35 USC 102 Novelty (BERT): 0.5083723084329025
- Combined Prediction Score: 0.6990468834464928
- Mean Citation Score: 307.380236
- Max Citation Score: 324.7327
- Similarity Product: 285.2981695512593

Labels:
- Claim Label 101: 1
- Claim Label 102: 1
- Claim Label 103: 1
- Claim Label 112: 1
- Combined Label: 1
- Label 101 Adjusted: 1

Dataset: test