Flow control valve

Abstract

To effectively reduce the noise caused by pressure fluctuations and a refrigerant separation phenomenon when refrigerant passes through a valve port.SOLUTION: A flow regulating valve 1 is designed to obtain equal percentage characteristics or characteristics close thereto as flow characteristics, and comprises a valve element 30 having a curved portion 33 that changes the flow rate of fluid flowing through a valve port 10 in accordance with a lift amount, in which the curvature or control angle of the curved portion 33 is increased continuously or stepwise as it approaches the tip. In the flow regulating valve, the diameter of the valve port 10 is sequentially increased in three or more stages as it moves away from a valve chamber 6. Specifically, from the valve chamber 6 side, a first valve port portion 11 having a diameter D1, a second valve port portion 12 having a diameter D2 (>D1), and a third valve port portion 13 having a diameter D3 (>D2) are provided in this order.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a flow rate adjusting valve provided with a valve body having a valve chamber and a valve port (orifice), and a valve element that changes the flow rate of a fluid flowing through the valve port according to the lift amount. In particular, the present invention relates to a flow rate adjusting valve suitable for adjusting the refrigerant flow rate in a heat pump type air conditioning system or the like. pump type air conditioning system or the like.

Background Art

[0002] In a flow rate adjusting valve, the relationship between the valve opening (lift amount) and the flow rate, that is, the flow rate characteristics, are well known as linear characteristics and equal percentage characteristics. The linear characteristic refers to a characteristic in which the change rate of the flow rate with respect to the change in the valve opening is constant, and the equal percentage characteristic refers to a characteristic in which the change rate of the valve opening is proportional to the flow rate.

[0003] FIG. 5 shows a main part of an example of a flow rate adjusting valve configured to obtain an equal percentage characteristic. The flow rate adjusting valve 1' in the illustrated example is used to adjust the refrigerant flow rate in a heat pump type air conditioning system or the like, and includes a valve body 5 provided with a valve chamber 6, a valve seat 8 formed of an inverted conical surface, and a valve port 15 formed of a cylindrical surface, and a valve element 20 that changes the flow rate of a fluid flowing through the valve port 15 according to the lift amount from the valve seat 8. The valve element 20 is moved up and down so as to contact and separate from the valve seat 8 by a screw feed type lifting drive mechanism including, for example, a valve shaft provided with a male screw, a guide stem provided with a female screw, and a stepping motor as described in Patent Document 1.

[0004] The valve element 20 has a contact surface portion 22 that contacts the valve seat 8, and an elliptical curved surface portion 23 that is continuous to the lower side of the contact surface portion 22 and is for obtaining an equal percentage characteristic as a flow rate characteristic. The curved surface portion ​​​​​​​​​​​​ 23 has a shape similar to the lower half of an egg, and its outer surface extends from the upper end 23a to the lower end 23 The curvature gradually increases as we move towards point b.

[0005] In the flow control valve 1' designed to obtain such equal percentage characteristics, Figure As shown by the thick arrow in 5, when the refrigerant flow direction is from valve chamber 6 to valve opening 15, The fluid flows along the curved surface 23, but a sudden pressure fluctuation and refrigerant separation phenomenon occur when it passes through the valve opening 15. This makes it easier for vortices and cavitation to occur and grow, resulting in relatively large There was a problem with noise generation.

[0006] Furthermore, in order to obtain the equal percentage characteristics as described above, the valve body 20 has an elliptical curved portion Providing 23 presents problems in terms of processing costs, cost-effectiveness, etc., as shown in Figure 6. Flow control valve 1' is designed to provide characteristics that approximate the equal percentage characteristic. ' is being developed. The flow control valve 1'' in the illustrated example is such that when the valve chamber forming member 6A is fixed Furthermore, it consists of a first valve opening 17A made of a short cylindrical surface and a second valve opening 17B made of a frustoconical surface. A valve opening 17 is provided, and a pipe joint 14 is connected to the lower outer circumference of the second valve opening 17B, to which a conduit is connected. The flow rate of the fluid flowing through the valve port 17 changes according to the lift amount from the connected valve body 5 and valve seat 8. It is equipped with a valve body 30 that causes this.

[0007] The valve body 30 has a seating surface portion 32 that sits on the valve seat 8, and a flow control portion connected to the lower side of the seating surface portion 32. It has a curved surface portion 33 to obtain characteristics that approximate the equal percentage characteristic. The curved portion 33 simulates an ellipsoidal surface, and as it approaches the tip, the control angle (the central axis of the valve body 30) A multi-stage (in this case, 5 stages) cone tape in which the intersection angle between line O and a parallel line is gradually increased. It has tapered surfaces 33A to 33E, and the first control angle θ1 of the uppermost conical tapered surface 33A is Typically, it is set to 3° < θ1 < 15° (5° in this case), and the bottom conical tapered surface portion 33 E is a pointed cone surface.

[0008] On the other hand, Patent Document 2 describes a flow control valve that is designed to obtain normal linear characteristics. By specifying the dimensions and shape of the valve opening, the pressure fluctuations during passage through the valve opening and the above-mentioned conditions are considered. A system is disclosed that suppresses noise generated due to phenomena such as refrigerant separation. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2012-172839 [Patent Document 2] Patent No. 5696093 [Overview of the project] [Problems that the invention aims to solve]

[0010] However, in the flow control valve described in Patent Document 2, the valve opening length is set to be considerably long. Because of this requirement, pressure loss becomes large, and there is a problem in that it is difficult to obtain the appropriate refrigerant flow rate. Furthermore, the dimensions and shape of the valve opening are designed to match the valve body for linear characteristics, as described above. Even when applied to flow control valves with equal percentage characteristics or similar characteristics, sufficient No noise reduction effect can be obtained.

[0011] This invention has been made in view of the above circumstances, and its purpose is to enable the passage of a valve opening. It is possible to effectively reduce the noise generated due to pressure fluctuations and refrigerant separation phenomena in the and to provide a flow rate adjustment valve capable of reducing pressure loss and the like.

Means for Solving the Problems

[0012] To achieve the above object, a flow rate adjustment valve according to the present invention includes a valve body provided with a valve chamber and a valve port, and a valve element that changes the flow rate of a fluid flowing through the valve port according to the lift amount. A pipe fitting with an inner diameter of D4 is connected to the valve opening, The valve port is provided with a first valve port portion of a cylinder having a diameter of D1, a second valve port portion of a cylinder having a diameter of D2, and a third valve port portion of a cylinder having a diameter of D3 in order from the valve chamber side, and D1 < D2 < D3 <D4 and is The pipe joint is connected to the valve body such that at least the third valve opening is positioned inside the pipe joint. The first valve port portion has a valve seat, a conical frustum-shaped tapered surface portion in the upper stage is provided between the first valve port portion and the second valve port portion, and between the second valve port portion and the third valve port portion The third valve opening is continuous with has a conical frustum-shaped tapered surface portion in the lower stage, (D2 / D1) < (D3 / D2), the valve element has a seating surface portion that seats on the valve seat of the valve port, and a curved surface portion that is continuous with the lower side of the seating surface portion and has a characteristic approximating an equal percentage characteristic as a flow rate characteristic. The curved surface portion is continuous with the lower side of the seating surface portion and has a conical tapered surface portion with a control angle of θ1. The taper angle of the upper conical frustum-shaped tapered surface portion is θu, and the under taper angle of the conical frustum-shaped tapered surface portion in the lower stage is θv, and θu > θ1 and θv > θ1.

[0013] In a preferred embodiment, in the central axis direction of the valve element, the conical frustum-shaped tapered surface portion in the lower stage is longer than the conical frustum-shaped tapered surface portion in the upper stage.

[0014] In another preferred embodiment, it further includes a pipe joint having an inner diameter of D4 connected to the valve port, and (D2 / D1) < (D3 / D2) < (D4 / D3).

Effects of the Invention

[0015] In the flow control valve according to the present invention, the diameter of the valve opening is sequentially divided into three or more stages from the valve chamber side to the lower end side. Next, the pressure is increased, so the refrigerant pressure gradually recovers as it passes through the valve opening, and pressure fluctuations are suppressed. This also rectifies the flow. In addition, (D2 / D1) and (D3 / D2) are within a specific range. By setting this, the generation of vortices and cavitation associated with pressure fluctuations and refrigerant separation phenomena occurs. The length is suppressed. Furthermore, (D2 / D1) < (D3 / D2) < (D4 / D3) This makes the flow even smoother, for example, equal percentage characteristics and approximations thereof. In a flow control valve with these characteristics, the noise level can be significantly reduced.

[0016] Furthermore, by setting (L2 / D1) and (L4 / D1) to specific ranges, the valve opening The length L2 is a flow rate regulator with equal percentage characteristics as described in Patent Document 2 or shown in Figure 5. Since it is shorter than valve length 1', the pressure loss is reduced, and the appropriate refrigerant flow rate can be obtained. . [Brief explanation of the drawing]

[0017] [Figure 1] A cross-sectional view of the main part of one embodiment of a flow control valve according to the present invention. [Figure 2] (A) A table showing measured data for verification valves No. 1 to 4 with some specifications and parameters changed, for confirming and verifying the effects of the present invention, and (B) A table showing verification conditions A to G. [Figure 3] (A) A graph showing the measured values ​​of verification valves No. 1 to 4 for each verification condition A to G, with the horizontal axis plotting the bore ratio: D2 / D1 and the vertical axis plotting the noise level [dB]. (B) A graph showing the measured values ​​of verification valves No. 1 to 4 for each verification condition A to G, with the horizontal axis plotting the bore ratio: D3 / D2 and the vertical axis plotting the noise level [dB]. [Figure 4](A) A table showing measured data for verification valves No. 5 to 8 with some specifications and parameters changed, in order to confirm and prove the effects of the present invention; (B) A table showing verification conditions H and I; (C) A graph showing the measured values ​​of verification valves No. 5 to 8 for each verification condition H and I, with the valve opening length ratio: L4 / D1 on the horizontal axis and sound pressure level [dB] on the vertical axis. [Figure 5] A partial cross-sectional view showing the main components of an example of a flow control valve designed to achieve equal percentage characteristics. [Figure 6] (A) A partial cross-sectional view when the valve is closed, and (B) A partial cross-sectional view when the valve is open, showing the main parts of an example of a flow control valve designed to obtain characteristics approximating the equal percentage characteristic. [Modes for carrying out the invention]

[0018] Embodiments of the present invention will be described below with reference to the drawings.

[0019] Figure 1 is a cross-sectional view of the main part of one embodiment of the flow control valve according to the present invention. In Figure 1, the parts correspond to those of the conventional flow control valve 1'' shown in Figure 6 mentioned above. The parts that do so are marked with a common symbol.

[0020] The flow control valve 1 in the illustrated embodiment is the same as the conventional flow control valve 1'' shown in Figure 6 above. In this way, characteristics that approximate the equal percentage characteristic are obtained, and valve chamber formation Member 6A is fixed in place, and a valve opening 10 (details described later), which is a characteristic feature of the present invention, is provided. The valve body 5 and the amount of lift from the valve seat 8 change the flow rate of the fluid flowing through the valve port 10. It comprises a valve body 30. The valve body 30 has the same structure as the conventional flow control valve 1'' shown in Figure 6. The structure consists of a seating surface 32 that sits on the valve seat 8, and a flow characteristic connected to the lower side of the seating surface 32. It has a curved surface portion 33 for obtaining characteristics that approximate the equal percentage characteristic. 3 has a plurality of (here, five) conical tapered surface portions 33A to 33E with a control angle (the intersection angle between the central axis O of the valve body 30 and the parallel line) gradually increased in steps as approaching the tip so as to approximate an ellipsoid surface. The first control angle θ1 of the uppermost conical tapered surface portion 33A is set to 3° < θ1 < 15° (here, 5°), and the lowermost conical tapered surface portion 33E is a pointed conical surface. And the valve port 10 opening into the valve chamber 6 has, in order from the valve chamber 6 side, a cylindrical first valve port portion 11 with a diameter D1, a cylindrical second valve port portion 12 with a diameter D2, and a cylindrical third

[0021] valve port portion 13 with a diameter D3. A pipe joint 14 with an inner diameter D4 to which a conduit is connected is connected to the lower outer periphery of the third valve port portion 13. Here, D1 < D2 < D3 < D4, and the diameter of the valve port 10 is sequentially increased in three steps as it moves away from the valve chamber 6. Here, in the present embodiment, (diameter ratio: D2 / D1) < (diameter ratio: D3 / D2) < (diameter ratio: D4 / D3), and (D2 / D1) and (D3 / D2) are each set within a specific range, that is, 1.08 < (D2 / D1) < 1.37 and 1.05 < (D3 / D2) < 1.43, based on trial production experiments and the like. Also, a frustum-shaped tapered surface portion 16 with a taper angle θu is formed between the first valve port portion 11 and the second valve port portion 12 (at the step portion), and a frustum-shaped tapered surface portion 18 with a taper angle θv is formed between the second valve port portion 12 and the third valve port portion 13 (at the

[0022] step portion). In addition, the valve port length (the length in the direction of the central axis O) of the first valve port portion 11 is L1, and that of the second valve port portion 12 is formed.

[0023] Furthermore, a frustum-shaped tapered surface portion 16 with a taper angle θu is formed between the first valve port portion 11 and the second valve port portion 12 (at the step portion), and a frustum-shaped tapered surface portion 18 with a taper angle θv is formed between the second valve port portion 12 and the third valve port portion 13 (at the step portion).

[0024] Moreover, the valve port length (the length in the direction of the central axis O) of the first valve port portion 11 is L1, and that of the second valve port portion 12 is ​​The valve opening length is L2, the valve opening length of the third valve opening 13 is L3, and the distance from the upper end of the second valve opening 12 to the third valve opening 1 Let L4 be the length to the bottom of 3, then (valve opening length ratio: L2 / D1) and (valve opening length ratio: L4 / D1) ) refers to a specific range determined based on prototype experiments, etc., i.e., 1.0 < (L2 / D1 The values ​​are set to )<2.0 and 2.3<(L4 / D1)<4.0.

[0025] In the flow control valve according to the present invention configured in this way, the diameter of the valve port 10 is far from the valve chamber 6. As it is passed through the valve opening, the refrigerant pressure is gradually increased in three stages. Recovery occurs, pressure fluctuations are suppressed, and flow rectification is achieved. Also, (D2 / D1), (D 3 / D2) is set within a specific range, causing vortices associated with pressure fluctuations and refrigerant separation phenomena. The occurrence and growth of cavitation can be reliably suppressed. Furthermore, (D2 / D1)<(D3 / Since D2) < (D4 / D3), the flow becomes even smoother, so equal In flow control valves having cent characteristics or similar characteristics, the noise level is significantly reduced. It is possible.

[0026] Furthermore, by setting (L2 / D1) and (L4 / D1) to specific ranges, L2 (or L1) has the same equal percentage characteristics as described in Patent Document 2 or shown in Figure 5. Since it is shorter than the flow control valve 1', the pressure loss is reduced, and the appropriate refrigerant flow rate can be obtained. can.

[0027] [Verification tests and results to verify the appropriate range for bore ratio and valve length ratio] In order to confirm and prove the effects described above, the inventors have shown Figures 2(A) and 4(A). As shown in the list, some specifications and parameters have been changed, with a bore ratio of (D2 / D1), (D 3 / D2)》Verification valves No. 1-4, and valve opening length ratio《(L4 / D1)》Verification valve No. 5 Prepare ~8 and apply the conditions A~G shown in Figure 2(B) and conditions H and I shown in Figure 4(B). Verification tests were then conducted. Valve No. for verification of bore ratio (D2 / D1, D3 / D2). The results of tests 1-4 are shown in Figures 3(A) and (B), as well as the valve for verifying the valve opening length ratio (L4 / D1). The test results for Nos. 5-8 are shown in Figure 4(C).

[0028] Note that in Figure 3(A), the horizontal axis represents the aperture ratio: D2 / D1, and the vertical axis represents the noise level [dB]. Figure 3(B) shows the measured values ​​of verification valves No. 1-4 for each verification condition A-G. The horizontal axis represents the bore ratio: D3 / D2, and the vertical axis represents the noise level [dB], for the verification valve N. Figure 4(C) shows the measured values ​​for o.1-4 for each verification condition A-G, with the valve opening length ratio on the horizontal axis. :L4 / D1 was measured, and the vertical axis was plotted as sound pressure level [dB], and the actual measurements were taken for verification valves No. 5-8. This graph shows the values ​​for each of the verification conditions H and I.

[0029] Furthermore, in the graphs in Figures 3(A), (B) and 4(C), Level 0 (reference) is the previous Flow control valve 1 having characteristics similar to the conventional equal percentage characteristics shown in Figure 6 described above. This shows the noise level and sound pressure level of the conventional product (hereinafter referred to as the "conventional product").

[0030] From the graph in Figure 3(A), the caliber ratio (D2 / D1) is 1.05 to 1.45 (as shown in the figure). The noise level is lower than conventional products across almost the entire range, especially between valve No. 3 and valve N The noise reduction effect is significant around 0.2, but (D2 / D1) is 1.08 (the diameter ratio of valve No. 4). )~1.37 (≒(1.31+1.42) / 2, the diameter ratio approximately midway between valve No. 2 and valve No. 1) It was confirmed that noise can be significantly reduced compared to conventional products if the noise level is within the specified range.

[0031] From the graph in Figure 3(B), the caliber ratio (D3 / D2) is 1.00 to 1.50 (as shown in the figure). The noise level is lower than conventional products across almost the entire range, especially between valve No. 3 and valve N The noise reduction effect is significant around 0.2, but (D3 / D2) is 1.08~1.43 (≒(1. If it is within the range of (35 + 1.50) / 2 (the diameter ratio approximately midway between valve No. 3 and valve No. 4), It was confirmed that this product significantly reduces noise compared to the previous model.

[0032] From the graph in Figure 4(C), the valve orifice length ratio: (L4 / D1) is 2.00 to 4.00 (as shown in the figure). In almost the entire range, the sound pressure level is equivalent to or lower than that of conventional products, and in particular, the valve The noise reduction effect is greatest around No. 6, but (L4 / D1) is 2.30 (valve opening of valve No. 5). If the ratio is greater than the length ratio and within the range of 4.00 (valve opening length ratio of valve No. 8), the noise level will be lower than that of conventional products. The effect is obtained (for example, the sound pressure level is 2 dB or more lower than the standard in condition I). Confirmed.

[0033] Although diagrams and other illustrations are omitted, if the valve orifice length ratio (L2 / D1) is within the range of 1.0 to 2.0 As a result, the sound pressure level becomes equivalent to or lower than that of conventional products, and a noise reduction effect is obtained that is greater than that of conventional products. This has also been confirmed.

[0034] In the above embodiment, the flow rate adjustment has characteristics that approximate the equal percentage characteristic. Although the application of the present invention to valve 1 has been described, the present invention is not limited to this, and As shown in Figure 5, the flow control valve 1' has an equal percentage characteristic, and also, This can also be applied to flow control valves with linear characteristics as described in authorized references 1 and 2, etc.

[0035] Furthermore, in the curved portion of the valve body, the control angle increases in stages towards the tip in the above embodiment. It is composed of multiple stages of tapered conical surfaces, but is not limited to this, as shown in Figure 5. A configuration with an ellipsoidal surface as shown, or a configuration in which the lower end (cap of the ellipsoid) of the ellipsoidal surface has been removed. Or, furthermore, a combination of an ellipsoidal surface and one or more conical tapered surfaces, etc. It may be further structured.

[0036] Furthermore, in the above embodiment, a pipe fitting 14 with an inner diameter of D4 is connected to the third valve opening 13. The configuration is such that a fourth valve opening with a diameter of D4 is formed on the side opposite the valve chamber of the third valve opening 13. However, it goes without saying that the same effects and benefits as described above can be obtained. [Explanation of symbols]

[0037] 1. Flow control valve 5 Valve body 6 valve chambers 10 valve openings 11. First valve opening 12 Second valve opening 13 Third valve opening 14 Pipe fittings 30 valve body 33 Curved part D1 Diameter of the first valve opening D2 Diameter of the second valve opening D3 Diameter of the third valve opening D4 pipe fitting inner diameter L1 Valve opening length of the first valve opening L2 Valve opening length of the second valve opening L3 Valve opening length of the third valve opening L4 Second to third valve opening length

Claims

1. The valve comprises a valve body having a valve chamber and a valve port, a valve element that changes the flow rate of the fluid flowing through the valve port according to the lift amount, and a pipe fitting with an inner diameter of D4 connected to the valve port. The valve opening is provided with, in order from the valve chamber side, a first valve opening of a cylinder with a diameter of D1, a second valve opening of a cylinder with a diameter of D2, and a third valve opening of a cylinder with a diameter of D3, where D1 < D2 < D3 < D4. The pipe joint is connected to the valve body such that at least the third valve opening is positioned inside the pipe joint. The first valve opening is equipped with a valve seat. Between the first valve opening and the second valve opening, there is an upper frustoconical tapered surface portion. Between the second valve opening and the third valve opening, there is a lower frustoconical tapered surface portion that is continuous with the third valve opening. (D2 / D1) < (D3 / D2), The valve body has a seating surface portion that sits on the valve seat of the valve opening, and a curved surface portion connected to the lower side of the seating surface portion, for obtaining flow characteristics that approximate equal percentage characteristics. The curved portion has a conical tapered surface portion that is connected to the lower side of the seating surface portion and has a control angle of θ1. A flow control valve characterized in that the taper angle of the upper frustoconical tapered surface is θu and the taper angle of the lower frustoconical tapered surface is θv, such that θu > θ1 and θv > θ1.

2. The flow control valve according to claim 1, characterized in that, in the axial direction of the central axis of the valve body, the lower frustoconical tapered surface portion is longer than the upper frustoconical tapered surface portion.

3. The valve opening is further provided with a pipe fitting having an inner diameter of D4, The flow control valve according to claim 1, characterized in that (D2 / D1) < (D3 / D2) < (D4 / D3).

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