The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 09, 1994
Filed:
Oct. 07, 1992
Masahiko Kashiwa, Kobe, JP;
Masanobu Kurumaji, Kobe, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
Abstract
A hydraulic press includes a fixed mold, a movable mold movable closely to or separately from the fixed mold, a hydraulic cylinder for moving and pressing the movable mold, and a hydraulic circuit for controlling the supply of a pressing oil in the hydraulic cylinder. The hydraulic circuit includes: a variable capacity pump connected to the hydraulic cylinder by an oil tube through a solenoid direction switching valve; a solenoid proportional flow control valve interposed on the way of an oil tube bypassing the solenoid direction switching valve; a detecting sensor for detecting the position or speed of the movable mold; a speed setter for setting the pressing speed of the movable mold; and a controller for comparing the output value of the detecting sensor with a speed set-up value thereby adjusting the opening of the solenoid proportional flow control valve. With this construction, it is possible to smoothly control the pressing speed in a low speed pressing region of the movable mold irrespective of the leaked oil amount and load on the pressing cylinder side.