Valves and valve actuation – Fluid actuated or retarded – Pilot or servo type motor
Patent
1993-02-19
1994-04-12
Michalsky, Gerald A.
Valves and valve actuation
Fluid actuated or retarded
Pilot or servo type motor
137491, 251 3002, F16K 3106, F16K 3140
Patent
active
053019202
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a high-speed solenoid valve apparatus for opening and closing a fluid passage at a high speed.
BACKGROUND ART
A high-speed solenoid valve is used to open and close a fluid passage for various types of control in a hydraulic circuit, for example. Such a high-speed solenoid valve has superior characteristics; that is, it can be switched over at high frequency, can be operated by directly receiving a digital signal from a control unit such as a microcomputer, and also can perform flow rate control through switching at high frequency. An example in which the high-speed solenoid valve is employed for drive control of a hydraulic cylinder will be described below with reference to the drawing.
FIG. 1 is a circuit diagram of a hydraulic circuit using a high-speed solenoid valve. In the drawing, denoted by reference numeral 1 is a hydraulic pump and 2 is servo cylinder. Connected to a rod of the servo cylinder 2 is a displacement volume varying mechanism, e.g., a swash plate, of a variable displacement hydraulic pump (not shown). Reference numeral 3 designates a reservoir (tank), 4A is a high-speed solenoid valve interposed between the hydraulic pump 1 and the head side of the servo cylinder 2, and 4B is a high-speed solenoid valve interposed between the head side of the servo cylinder 2 and the reservoir 3.
In order to properly control a delivery rate of the variable displacement hydraulic pump, when a control signal is outputted from the microcomputer (not shown) to the high-speed solenoid valve 4A, for example, the high-speed solenoid valve 4A is switched to the lower shift position in the drawing. As a result, the servo cylinder 2 is driven in the direction of extension of the rod dependent on a difference in the pressure receiving area between both chambers of the servo cylinder 2, thereby increasing (or decreasing) a tilting amount of the swash plate. On the contrary, when a control signal is outputted to the high-speed solenoid valve 4B to switch it over to the lower shift position, the head side of the servo cylinder 2 is communicated with the reservoir 3, whereby the rod is contracted to decrease (or increase) a tilting amount of the swash plate. That operation is carried out with high responsibility by direct application of a digital signal to the valve from the microcomputer.
While the high-speed solenoid valve has the superior characteristics as mentioned above, it also has the problem below. More specifically, to achieve a high-speed operation, the high-speed solenoid valve must be so structured as to have a small diameter and short stroke of a spool. Therefore, the pressure loss is increased and the flow rate that can be handled is decreased. This necessarily limits the size, output and other rated values of the hydraulic cylinder, which can be directly controlled thereby. One means for solving this problem is to raise a pressure supplied to the high-speed solenoid valve. But, this means is unfavorable in that the energy loss becomes too large. Another solution means, of increasing the size of the high-speed solenoid valve, is difficult to practice from the above structural reason, so long as the current operating voltage is employed as it is. If the valve size is increased without respect of such limitations, the primary characteristic of the high-speed solenoid valve, i.e., the responsivity, would be deteriorated.
In view of the above existing state of the art, the inventor has previously proposed a high-speed solenoid valve apparatus disclosed in JP, A, 62-292982. This high-speed solenoid valve apparatus is shown in FIG. 2. Referring to FIG. 2, denoted by 10 is a body which forms an outer shell of the high-speed solenoid valve apparatus and which also has an inlet port 11 and an outlet port 12. Between the inlet port 11 and the outlet port 12, a high-speed solenoid valve section 10A and a logic valve section 10B are juxtaposed in the vertical direction. The high-speed solenoid valve section 10A comprises a first sleeve 13 forming an outer shell t
REFERENCES:
patent: 2964286 (1960-12-01), Hoskins
patent: 3977649 (1976-08-01), Zeuner et al.
patent: 4336903 (1982-06-01), Zirps
Hitachi Construction Machinery Co. Ltd.
Lee Kevin L.
Michalsky Gerald A.
LandOfFree
High-speed solenoid valve apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High-speed solenoid valve apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High-speed solenoid valve apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2093827