valve

Abstract

To provide a valve having a stem with a guide portion formed therein for vibration prevention, which does not obstruct the flow of fluid. [Solution] The valve comprises a valve body having an inlet passage 11 and an outlet passage 12 through which fluid flows, and a communication section communicating with both passages, with a valve seat 14 formed on the communication section; a valve body 21 at its tip for adjusting the fluid flow by contacting and separating from the valve seat, a guide section 22 disposed on the base end side of the valve body which slides with the communication section and has a chamfered section formed to allow fluid to pass through, the guide section and the valve body are connected by an intermediate section 23 which tapers towards the tip, the guide section and the outlet passage interfere with each other within the movable range of the valve body, and an actuator for moving the stem. A tapered surface 25 which tapers towards the tip is formed at the lower end of the guide section and is connected to the intermediate section, and a narrow diameter section 26 having the same outer diameter as the outer diameter of the tip of the tapered surface is formed between the tapered surface and the intermediate section.

Description

Technical Field

[0001] This invention relates to a valve.

Background Art

[0002] In recent years, with the development of fuel cell technology and the like, it has been required to flow high-pressure fluids such as high-pressure hydrogen through a valve. For example, when used under fluid conditions where the difference between the primary-side pressure and the secondary-side pressure of the valve is 50 MPa or more, or under fluid conditions where the primary-side pressure exceeds 70 MPa, the stem may vibrate, and the tip of the valve body formed at the tip of the stem may contact the valve seat surface, causing problems such as damage to the valve seat and leakage. In the valve described in Patent Document 1, a guide portion is provided to prevent vibration.

[0003] The valve shown in FIG. 4 is the valve described in Patent Document 1. The valve 100 includes a valve body 10, a valve seat body 13 in which a valve seat 14 is formed, a plug body 16, a stem 120, and an actuator 30. In the valve body 10, an inflow passage 11, an outflow passage 12, and a communication portion 15 are formed. On the stem 120, a valve body 121 is formed at the lower end portion, and a guide portion 122 for preventing vibration of the stem 120 is formed above the valve body 121. Vibration is prevented by sliding the outer peripheral surface of the guide portion 122 on the inner surface of the communication portion 15.

[0004] FIG. 5(A) is a partial cross-sectional view of FIG. 4. FIG. 5(B) is an enlarged view of FIG. 5(A). The valve body 121 at the tip of the stem 120 is lifted by a dimension L, and the fluid enters the inside of the valve seat body 13 from the inflow passage 11, flows upward, passes through the gap between the chamfered portion 124 and the communication portion 15, and flows out to the outside through the outflow passage 12.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] Figure 6 shows how the stem 120 interferes with the guide section 122 and the outflow passage 12 as it is gradually lifted upward. The figures show the state when the lift value L is 2 mm, 4 mm, 6 mm, and 8 mm.

[0007] The lower graph in Figure 6 shows the relationship between the lift value L (mm) and the difference D (%) between the design value and the actual flow rate. The design value for flow rate is the theoretically calculated value based on the required valve capacity coefficient (Cv value) and valve characteristic specifications. A value greater than 0 indicates that more fluid is flowing than the design value, and a value less than 0 indicates that less fluid is flowing than the design value. For all lift values ​​L from 1 mm to 8 mm, the actual flow rate is less than the design value. In particular, the difference is large in the L range from 1 mm to 5 mm.

[0008] The present invention has been made in view of the above, and its purpose is to provide a valve having a stem in which a guide portion for vibration prevention is formed, and which does not obstruct the flow of fluid. [Means for solving the problem]

[0009] The present invention relates to a valve comprising: a valve body having an inlet passage and an outlet passage through which fluid flows, and a communication portion communicating with both passages, the communication portion having a valve seat formed thereon; a valve body having a valve element at its tip for adjusting the fluid flow by contacting and separating from the valve seat, a guide portion disposed on the base end side of the valve element which slides in contact with the communication portion and has a chamfered portion formed thereon for allowing fluid to pass through, the guide portion and the valve element being connected at an intermediate portion which tapers towards the tip, the guide portion and the outlet passage interfering with each other within the movable range of the valve element, and an actuator for moving the stem, wherein a tapered surface is formed at the lower end of the guide portion which connects to the intermediate portion and tapers towards the tip, and a narrow diameter portion having the same outer diameter as the outer diameter of the tip of the tapered surface is formed between the tapered surface and the intermediate portion.

[0010] The valve of the present invention is equipped with a stem in which the guide portion and the outflow passage interfere with each other within the movable range of the valve body. A tapered surface is formed at the lower end of the guide portion, which is connected to an intermediate portion and tapers towards the tip. Between this tapered surface and the intermediate portion, a narrow-diameter portion is formed, having the same outer diameter as the outer diameter of the tip of the tapered surface. By adopting this shape, the obstruction of fluid flow caused by the presence of the guide portion can be reduced. In the valve described in Patent Document 1 (Figures 4-6), it is thought that obstruction due to fluid turbulence occurs in the lower shape of the guide portion 122, resulting in a decrease in flow rate. In contrast, it is inferred that the flow rate is stabilized by the flow straightening effect of the valve shape of the present invention. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a valve having a stem with a guide portion formed therein for vibration prevention, which does not obstruct the flow of fluid. [Brief explanation of the drawing]

[0012] [Figure 1] This is a partial cross-sectional view showing the entire valve according to the embodiment. [Figure 2] (A) is a partial cross-sectional view of the main part of the valve in the embodiment, and (B) is a further enlarged partial cross-sectional view of (A). [Figure 3] The images show enlarged views of the main components of the valve in the example, when the lift values ​​are set to 2 mm, 4 mm, 6 mm, and 8 mm, and a graph showing the flow rate. [Figure 4] This is a partial cross-sectional view showing the entire valve according to Patent Document 1. [Figure 5] (A) is a partial cross-sectional view of the main part of the valve described in Patent Document 1, and (B) is a further enlarged partial cross-sectional view of (A). [Figure 6] This shows enlarged views of the main parts and a graph showing the flow rate for the valve described in Patent Document 1, when the lift values ​​are set to 2 mm, 4 mm, 6 mm, and 8 mm. [Modes for carrying out the invention]

[0013] The embodiments of the present invention will be described in detail below with reference to the drawings. The following embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or its uses.

[0014] The valve 1 shown in Figure 1 consists of a valve body 10, a valve seat body 13 on which a valve seat 14 is formed, a plug body 16, a stem 20, and an actuator 30. The valve body 10 has an inlet passage 11, an outlet passage 12, and a communication portion 15. The stem 20 has a valve body 21 formed at its lower end, and a guide portion 22 for preventing vibration of the stem 20 is formed on the upper part of the valve body 21. Vibration is prevented by sliding the outer surface of the guide portion 22 against the inner surface of the communication portion 15.

[0015] Figure 2(A) is a partial cross-sectional view of Figure 1. Figure 2(B) is a further enlarged view of Figure 2(A). The valve body 21 at the tip of the stem 20 is lifted by dimension L, and the fluid enters the interior of the valve seat body 13 from the inlet passage 11, flows upward, passes through the gap between the chamfered portion 24 and the communication portion 15, and flows out to the outside through the outlet passage 12.

[0016] Figure 3 shows the state where the stem 20 is lifted upward little by little and interferes with the guide portion 22 and the outflow passage 12. The lift values L are shown as 2 mm, 4 mm, 6 mm, and 8 mm.

[0017] The lower graph in Figure 3 shows the relationship between the lift value L (mm) and the difference D (%) between the designed value and the actual flow rate with respect to the flow rate. The broken line graph indicated by black circles is the valve of the embodiment, and the broken dotted line graph indicated by black squares is the valve of Patent Document 1. The valve of the embodiment is much closer to the designed value compared to the valve of Patent Document 1, and particularly shows a significant improvement in the range where the lift value L is 1 mm to 4 mm. This is presumably because the guide portion 22 inhibits the flow of the fluid less.

Industrial Applicability

[0018] As described above, the present valve can be applied to valves in general having a stem with a guide portion formed for vibration prevention, and can provide a valve that inhibits the flow of fluid less.

Explanation of Signs

[0019] 1; Valve 10; Valve body 11; Inflow passage 12; Outflow passage 13; Valve seat body 14; Valve seat 15; Communication portion 16; Plug body 20; Stem 21; Valve element 22; Guide portion 23; Intermediate portion 24; Chamfered portion 25; Tapered surface 26; Small diameter portion 30; Actuator L; Lift value

Claims

[Claim 1] A valve body comprising an inlet passage and an outlet passage through which fluid flows, and a communication section communicating with both of these passages, the communication section having a valve seat formed therein, The valve body is provided at its tip for adjusting the fluid flow by contacting and separating from the valve seat, and a guide portion is provided on the base end side of the valve body that slides in contact with the communication portion and has a chamfered portion formed therein for fluid passage, and the guide portion and the valve body are connected at an intermediate portion that tapers towards the tip, and the stem interferes with the guide portion and the outflow passage within the movable range of the valve body, A valve comprising an actuator for moving the aforementioned stem, A valve in which a tapered surface is formed at the lower end of the guide portion, with the tip side tapering towards the end and connected to the intermediate portion, and a narrow-diameter portion having the same outer diameter as the outer diameter of the tip of the tapered surface is formed between the tapered surface and the intermediate portion.

Images