Kasumigaura, Japan

Kenji Hiraku

This inventor holds 53 USPTO granted patents and 9 published patent applications and 14 EPO patents, primarily in Construction Machinery (CPC class F15B). Top assignees: Hitachi Construction Machinery Co., Ltd., Hitachi, Ltd., Hitachi-High-Technologies Corporation. Active years: 1997-2024.

IDiyas Innovation Intelligence. (2026). Inventor Profile: Kenji Hiraku. Retrieved from https://idiyas.com/inventor/kenji-hiraku

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

USPTO Granted Patents = 53 

% Patents Active = 71.7

 

Average Co-Inventor Count = 3.9

ph-index = 8

Forward Citations = 283(Granted Patents)

Forward Citations (Not Self Cited) = 249(Dec 10, 2025)


Inventors with similar research interests:


Location History:

  • Ibaraki-ken, JP (1997)
  • Niihari-gun, JP (1999)
  • Chiyoda-machi, Niihari-gun, Ibaraki JP (2000)
  • Chiyoda, JP (2003 - 2009)
  • Tokyo, JP (2017)
  • Ibaraki, JP (2010 - 2019)
  • Kasumigaura, JP (2010 - 2024)
  • Tsuchiura, JP (2016 - 2024)

Company Filing History:


Years Active: 1997-2024

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Areas of Expertise:
Construction Machine
Work Machine
Hydraulic Drive System
Drive Unit
Fuel Injection Device
Hydraulic System
Driving Device
Liquid Chromatograph
Sound Generator
Rotary Motion
Linear Motion
Check Valve
53 patents (USPTO):Explore Patents

Title: The Innovations of Kenji Hiraku in Construction Machinery

Introduction: Kenji Hiraku, based in Kasumigaura, Japan, is a renowned inventor with a remarkable portfolio of 53 patents. His contributions primarily focus on the advancement of construction machinery, showcasing innovative solutions that enhance operational efficiency and reliability in the industry.

Latest Patents: Among his latest innovations, Hiraku has developed a construction machine equipped with a hydraulic actuator driven by a hydraulic pump designed for a closed circuit. This groundbreaking design aims to prevent oil film breakage within the hydraulic pump, thus improving reliability and ensuring a higher operational rate. The construction machine features a switching valve located in a branch hydraulic line that connects the suction/delivery ports of the closed circuit pump to a charge line. This valve opens and closes based on control signals from a controller, which maintains a predetermined delivery volume or more when the closed circuit pump experiences a zero delivery volume for a prolonged period.

Additionally, Hiraku has introduced another construction machine designed to effectively utilize return oil from a hydraulic actuator. This invention allows a controller to compute the return oil flow rate and supplies it to a second hydraulic actuator based on the operation signals from two separate devices. By determining the smaller flow rate as the regeneration flow rate and adjusting control valve openings accordingly, this invention ensures optimal efficiency and reliable hydraulic system performance.

Career Highlights: Hiraku’s career includes significant positions at Hitachi Construction Machinery Co., Ltd. and Hitachi, Ltd., where he contributed to developing cutting-edge technologies within the construction sector. His work in these esteemed companies has solidified his reputation as a leader in construction machinery innovation.

Collaborations: Throughout his career, Hiraku has collaborated with notable colleagues such as Hiromasa Takahashi and Juri Shimizu. These professional relationships have fostered a collaborative environment that promotes creativity and innovation in the field of construction machinery.

Conclusion: Kenji Hiraku’s contributions to construction machinery through his extensive patent portfolio demonstrate a commitment to innovation and excellence. His latest designs not only enhance the operational capabilities of hydraulic systems but also represent significant advancements in the construction equipment industry. With his impressive track record, Hiraku continues to inspire future generations of inventors and engineers.

Profile summary based on public USPTO records.
Data Sources: USPTO Patent Grant XML, Patent Center, EPO & CIPO • Normalized by IDiyas Innovation Graph. Methodology & provenance architecturePlease report any incorrect information to [email protected]
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