JPH0460283A - Constant rate exhaust valve - Google Patents

Abstract

PURPOSE:To finely adjust pressure reduction characteristics by arranging a movable body, which is freely movable in relation to a rubber sleeve, in the rubber sleeve and varying the opening area of a slit by means of the movement of the movable body. CONSTITUTION:A movable body 36 is moved to change the position of an adjusting section 61. Since the opening area of a slit 31 which is opened by the adjusting section 61 varies depending upon what part of a slit 31 the adjusting section 61 is positioned at, pressure reduction characteristics can be adjusted. Therefore, the pressure reduction characteristics can finely be adjusted by adjusting the opening area of the slit by means of the movement of the movable body. In addition, in the case of measuring blood pressure by a finger, the setting to the proper pressure reduction characteristics can easily done.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a constant speed exhaust valve used in a blood pressure monitor.

[Conventional technology]

A blood pressure monitor, especially an electronic blood pressure monitor, is usually composed of a blood pressure monitor main body 1 and a cuff band 2, as shown in FIG. 7. Inside the main body 1, as shown in FIG. A pump 4 for supplying air, a constant speed exhaust valve 3, and a rapid exhaust valve 5 are provided as members of the pneumatic system. Then, the cuff band 2 wrapped around the arm is pressurized with air pressure, and then the air inside the cuff band 2 is gradually released to measure the blood pressure. In order to facilitate this, it is desired that the pressure reduction characteristics per unit time be constant, as shown in FIG. 8(a). And if you use an orifice valve as an exhaust valve,
As shown in FIG. 8(b), when the pressure is high, the pressure is reduced rapidly, and when the pressure is low, the pressure is reduced slowly. For this reason, the 10th constant speed exhaust valve 3 has a simple structure but can obtain the above pressure reducing characteristics.
The device shown in FIG. 1 or FIG. 11 has been conventionally provided. The former has a long axially long slit 31 provided in the rubber sleeve 30, and a linear member 32 is inserted through the slit 31 to maintain the slit 31 slightly open. The slit 31 is kept slightly open by applying strain with the pressing member 33 to the rubber sleeve 3O provided with the slit 31. Figure 12(a) shows the no-load state,
The figure (b) shows a state in which strain is applied and the opening is applied. In these devices, the amount of exhaust gas is changed according to the exhaust pressure by utilizing the change in the opening area of the slit 31 due to the elastic deformation of the rubber sleeve 30 when exhaust pressure is applied to the outer peripheral surface of the rubber sleeve 30. I have to. FIG. 12(e) shows that when high exhaust pressure is applied, the slit 31
This shows a state in which the opening area of .

[Problem to be solved by the invention]

By the way, when blood pressure is measured on the upper arm, the capacity of the cuff band is large, so even if the decompression characteristics slightly deviate from what is desired, it is not much of a problem, but with a type that measures blood pressure on the finger, Since the capacity of the cuff band is extremely small, even a slight deviation in the decompression characteristics will make blood pressure measurement inaccurate. In addition to this, it is not possible to make adjustments to eliminate the effects of variations in rubber quality and wall thickness of the rubber sleeve, resulting in considerable defects. In the latter case, the rubber sleeve 3 provided by the pressing member 33
The decompression characteristics can be adjusted by changing the magnitude of the 0 strain, but since the decompression characteristics change greatly with a small difference in strain, in practice it is difficult to measure blood pressure with a finger. cannot be used. The present invention has been made in view of these points, and its purpose is to provide a constant speed exhaust valve that allows delicate pressure reduction characteristics to be adjusted.

[Means to solve the problem]

Accordingly, the present invention provides a constant speed exhaust valve that exhausts air through a slit formed in the axial direction of a rubber sleeve that elastically deforms in response to exhaust pressure. On the other hand, it is characterized in that a movable body that is freely movable is disposed within a rubber sleeve, and the opening area of the slit is made variable by the movement of the movable body. [Operation] According to the present invention, the pressure reduction characteristics can be finely adjusted by adjusting the opening area of the slit using the movable body. [Embodiments] The present invention will be described in detail below based on illustrated embodiments.The constant speed exhaust valve 3 shown in FIG.
A bottomed cylindrical rubber sleeve 30 disposed inside the case 34 and a flange provided on the open end side of the rubber sleeve 30 are connected to the case 34.
The holding plate 35 clamps and fixes the rubber sleeve 30 inside the case 34, and a movable body 36. Screwed into the armor screw formed on the
The case 34 and the rubber sleeve 30 are movable in the axial direction by screwing forward and backward. A space is left between the inner peripheral surface of the case 34, which has a connection port 37 connected to the cuff band side on the other end side, and the outer peripheral surface of the rubber sleeve 30, and this space in the rubber sleeve 30. A long slit 31 in the axial direction is provided in the part facing the
is formed, and the space inside and outside the rubber sleeve 30 has a slit 31! It is designed to communicate with each other. Furthermore, as shown in FIG.
The adjusting part 61 has an outer diameter slightly larger than the inner diameter of the adjusting part 61. Therefore, in this constant speed exhaust valve 3, the movable body 36 and the adjustment part 61 are located in the portion of the rubber sleeve 30 where the slit 31 is formed, so that the slit 31 is pushed open from the inside, and When the exhaust pressure applied to the outer peripheral surface of the rubber sleeve 30 is high, the opening area of the slit 31 becomes smaller due to elastic deformation of the rubber sleeve 30. As the exhaust pressure decreases, the opening area of the slit 31 increases, and as a result, certain pressure reduction characteristics can be obtained. When this pressure reduction characteristic needs to be adjusted, the movable body 36 can be moved to change the position of the adjustment section 61. Since the opening area of the slit 61 pushed open by the adjusting part 61 changes depending on the position of the adjusting part 61 in the slit 31, the pressure reduction characteristics can be adjusted. Other embodiments are shown in FIGS. 3 and 4. Here, the total axial length of the adjustment portion 61 in the movable body 36 is made longer than the total length of the slit 31. Since the outer diameter of the adjustment part 61 is slightly larger than the inner diameter of the rubber sleeve 30, the rubber sleeve 3
Air is prevented from flowing where the adjusting part 61 is in contact with the inner circumferential surface of the part where the slit 31 is not formed, and therefore the effective opening area of the slit 31 is equal to the area where the adjusting part 61 is located. Only the parts that are not included will be included. Air entering the rubber sleeve 30 through this portion is exhausted through a vent hole 60 formed in the movable body 36. If the movable body 36 is moved in the axial direction, the effective opening area of the slit 31 will naturally change, so the pressure reduction characteristics can be adjusted. In the embodiment shown in FIGS. 5 and 6, the outer diameter of the adjusting portion 61 is approximately the same as the inner diameter of the rubber sleeve 30, and
A convex portion 62 is made to protrude from a part of the outer peripheral surface of the adjustment portion 61. Now, if the movable body 31 is screwed forward and backward, the convex portion 62 will move while rotating in the axial direction of the rubber sleeve 30.
At this time, check where the convex portion 62 is located in the axial direction of the slit 31 of the rubber sleeve 30,
The opening area of the slit 31 changes depending on where it is located in the circumferential direction of the slit 31, and thereby the pressure reduction characteristics can be adjusted.

【Effect of the invention】

As described above, in the present invention, the pressure reduction characteristics can be finely adjusted by adjusting the opening area of the slit using the movable body, and even when measuring blood pressure with a finger, the pressure reduction characteristics can be adjusted appropriately. It is easy to set up.

[Brief explanation of drawings]

Fig. 1 is a sectional view of one embodiment of the present invention, Fig. 2 is a perspective view of the same movable body, Fig. 3 is a sectional view of another embodiment, and Fig. 4 is a perspective view of the same movable body; Fig. 5 is a sectional view of another embodiment, Fig. 6 is a perspective view of the movable body same as above, Fig. 7 is a perspective view of a blood pressure monitor, Fig. 8 is a block diagram of the pneumatic system, and Fig. 9 (a) ( b)
is an explanatory diagram of the pressure reduction characteristics, Figure 10 is a perspective view of the conventional example, and Figure 1 is a perspective view of the conventional example.
Figure 1 is a sectional view of another conventional example, Figure 12 (a) (b)
(c) is an explanatory diagram of the same operation as above, and 3 is a constant speed exhaust valve;
30 is a rubber sleeve, 31 is a slit, and 36 is a movable body. Fig. 1 30 Rubber sleeve 31 pickpocket/l- 3 (+ -1'l moving agent patent attorney stone 1) head 7 Fig. 3 Fig. 7 Fig. 8 Fig. 5 Fig. 9 Rl1il TOEc) Fig. 10

Claims (1)

[Claims] (1) In a constant speed exhaust valve that exhausts air through a slit formed in the axial direction of a rubber sleeve that elastically deforms in response to exhaust pressure, the valve has an outer diameter slightly larger than the inner diameter of the rubber sleeve and moves relative to the rubber sleeve. A constant speed exhaust valve characterized in that a freely movable body is disposed within a rubber sleeve, and the opening area of the slit is made variable by movement of the movable body.