Flow control valve and sphygmomanometer

Abstract

A flow control valve, comprising a frame case (2) having a gas inlet (1a) and a gas outlet (1b), an operating shaft (4) disposed so as to be allowed to move close to and away from the inlet (1a), and an orifice packing (3) installed at the tip of the operating shaft and opening and closing the inlet (1a), wherein two permanent magnets (5a, 5b) are installed on the operating shaft (4) through a yoke (22a) in the state where the same electrodes thereof are opposed to each other and three electromagnetic coils (6a, 6b, 6c) are disposed on the outside of the permanent magnets (5a, 5b) in the state where the winding directions of the coils positioned adjacent to each other are reverse to each other and, when a current flows through the electromagnetic coils (6a, 6b, 6c), electromagnetic forces generated by the electromagnetic coils (6a, 6b, 6c) and the permanent magnets (5a, 5b) are combined with each other, the operating shaft (4) is moved leftward by the combination thrust as shown in the figure so that the orifice packing (3) closes the inlet (1a), whereby the flow control valve of small size with less power consumption and less mal-function can be provided by effectively utilizing the thrust by the electromagnetic force while the structure thereof is simple.

Description

technical field [0001] The present invention relates to a flow control valve used, for example, as an air discharge device in a sphygmomanometer, and a sphygmomanometer having such a flow control valve. Background technique [0002] Various proposals have been made for sphygmomanometers. Among them, there is a sphygmomanometer that measures a person's blood pressure during the depressurization process after the pressure in the envelope is raised to a predetermined value, and then the pressure is gradually lowered. In such a sphygmomanometer, there is a "flow control valve" disclosed in Japanese Patent Application Laid-Open No. 6-47008 as a flow control valve for gradually reducing the pressure in the cuff. The structure of the flow control valve described in this gazette is as follows: a pressure inflow port (gas inflow port) and a pressure outflow port (gas outflow port) are formed in the front housing, and the drive shaft is supported in a forward and backward manner relat...

AI Technical Summary

Problems solved by technology

However, in the structure shown in FIGS. 15A and 15B , the thrust formed by the electromagnetic force generated by the electromagnetic coil 6 cannot be effectively utilized, and the flow rate control that requires a large valve load (the pressing force of the orifice seal 3 to the inlet 1a) Problems such as increased size and increased power consumption in the valve

[0011] That is, in the flow control valve shown in FIGS. 15A and 15B, since the pressure contact force of the orifice seal member 3 to the inflow port 1a is not so large, in the wrist sphygmomanometer, a greater pressure is required than that of the finger sphygmomanometer. The crimping force is insufficient, and the inflow port 1a may not be completely closed when the envelope is pressurized above the maximum pressure value.

In order to avoid this, a larger crimping force will be created, which will cause the problem of increasing the flow control valve and increasing power consumption.

[0012] In addition, in the flow control valve shown in Figs. 15A and 15B, when receiving an impact such as falling, the permanent magnet 5 is often cracked due to its brittleness, resulting in a problem of poor flow control characteristics.

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