US4796661A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Proportional electro-hydraulic pressure control valve
Assignee: Yuken Kogyo Co Ltd
•
Filing: 1986-08-19
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Granted: 1989-01-10
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Expires: 2006-08-19
Abstract
Abstract A proportional electro-hydraulic pressure control valve incorporates a pressure sensor in its valve body and the hydraulic fluid pressure in a pressure detecting fluid path provided in the valve body is delivered as an electric signal output by the pressure sensor. The pressure detecting fluid path is connected to a hydraulic fluid inlet port directly or through a restrictor or alternately the fluid path is connected to a pressure detecting port separated from both of the hydraulic fluid inlet port and a hydraulic fluid outlet port. The electric signal output from the pressure sensor is utilized to provide a numerical display of the controlled pressure or to effect the feedback control of a solenoid drive current through a closed loop.
Inventors
- 👤 Yasuo Hishinuma
- 👤 Hiroshi Ito
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:26
CPC Classifications
G; G05; G05D; G05D16/00; G05D16/20; G05D16/2093; G05D16/2097; G05D16/024; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7758; Y10T137/7761; Y10T137/8158; Y10T137/8326
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
202 words
In a proportional electro-hydraulic relief valve, said relief valve comprising: a valve body, a hydraulic fluid inlet port in said valve body, a hydraulic fluid outlet port in said valve body, a pressure detecting fluid path in said valve body filled with hydraulic fluid, valve means arranged between said ports to control a pressure at said hydraulic fluid inlet port, and proportional plunger means slidably mounted in said valve body for causing application of a force proportional to an input current for setting a controlled pressure to act on said valve means, said valve means including a sensor holder having a pressure sensor mounted in a sensor receiving hole defined by said valve body for detecting a hydraulic fluid pressure in said pressure detecting fluid path and outputting the same as an electric signal, a pressure sensing portion of said pressure sensor being positioned so as to be exposed to said pressure detecting fluid path, said sensor holder being positioned and fixed in said valve body by a plug-and-snap assembly for preventing said pressure sensor from slipping out of position under the action for hydraulic pressure, and notches formed in said plug-and-snap assembly for accommodating signal lead wires from said pressure sensor.
Claim 2
Dependent Claim
202 words
In a proportional electro-hydraulic relief valve, said relief valve comprising: a valve body, a hydraulic fluid inlet port in said valve body, a hydraulic fluid outlet port in said valve body, a pressure detecting fluid path in said valve body filled with hydraulic fluid, valve means arranged between said ports to control a pressure at said hydraulic fluid inlet port, and proportional plunger means slidably mounted in said valve body for causing application of a force proportional to an input current for setting a controlled pressure to act on said valve means, said valve means including a sensor holder having a pressure sensor mounted in a sensor receiving hole defined by said valve body for detecting a hydraulic fluid pressure in said pressure detecting fluid path and outputting the same as an electric signal, a pressure sensing portion of said pressure sensor being positioned so as to be exposed to said pressure detecting fluid path, said sensor holder being positioned and fixed in said valve body by a plug-and-snap assembly for preventing said pressure sensor from slipping out of position under the action for hydraulic pressure, and notches formed in said plug-and-snap assembly for accommodating signal lead wires from said pressure sensor.
Claim 3
Dependent Claim
23 words
A pressure control valve according to claim 1, wherein said pressure detecting fluid path is directly communicating with said hydraulic fluid inlet port.
Claim 4
Dependent Claim
49 words
A pressure control valve according to claim 1, wherein said pressure detecting fluid path is separated from both of said hydraulic fluid inlet port and said hydraulic fluid outlet port, and wherein a pressure detecting port communicating with said pressure detecting fluid path is provided in said valve body.
Claim 5
Dependent Claim
48 words
A pressure control valve according to claim 1, wherein said pressure detecting fluid path is communicated with said hydraulic fluid inlet port with an opening limited by an orifice, and wherein a pressure detecting port communicating with said pressure detecting fluid path is provided in said valve body.
Claim 6
Dependent Claim
19 words
A pressure control valve according to claim 1, wherein said pressure sensor comprises a semiconductor gage type pressure sensor.
Claim 7
Dependent Claim
22 words
A pressure control valve according to claim 1, further comprising a power amplifier for controlling an input current to said plunger means.
Claim 8
Dependent Claim
46 words
A pressure control valve according to claim 6, further comprising a feedback circuit for comparing an output signal of said pressure sensor with an externally applied command signal to generate a difference signal and applying said difference signal as a feedback signal to said power amplifier.
Claim 9
Dependent Claim
18 words
A pressure control valve according to claim 6, further comprising an electric equipment box accommodating said power amplifier.
Claim 10
Dependent Claim
60 words
A pressure control valve according to claim 8, wherein said electric equipment box comprises a housing of a three-part structure including a bottom cover attached to mounting component parts including said plunger means, an amplifier case fixedly mounted on said bottom cover to form body walls, and a detachable top cover for closing a top opening of said amplifier case.
Claim 11
Dependent Claim
36 words
A pressure control valve according to claim 9, wherein a recess is formed on a lower surface of said bottom cover to form a layer of air between said lower surface and said mounting component parts.
Claim 12
Dependent Claim
16 words
A pressure control valve according to claim 9, wherein said top cover includes a pressure indicator.
Claim 13
Dependent Claim
17 words
A pressure control valve according to claim 9, wherein said amplifier case is formed with radiation fins.
Claim 14
Dependent Claim
43 words
A pressure control valve according to claim 9, wherein said amplifier case is made of a heat conducting material and including a portion contacting thermally with a heat radiative device of an amplifier circuit for dissipation of heat from said heat radiative device.
Claim 15
Dependent Claim
27 words
A pressure control valve according to claim 13, wherein said amplifier case is formed with a hole exclusively used for direct mounting of said heat radiative device.
Claim 16
Dependent Claim
43 words
A pressure control valve according to claim 13, wherein said heat radiative device directly mounted on said amplifier case for heat dissipation is fixedly mounted on a circuit board within said amplifier case whereby said circuit board is fastened to said amplifier case.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-01-10 | 1992-07-11 | 1993-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-10 | 1996-07-11 | 1997-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-10 | 2000-07-11 | 2001-01-10 | $7700.00 | Window Closed / Lapsed |