A high-precision micro-flow regulating valve

Abstract

The invention discloses a high-precision micro-flow regulating valve, comprising a housing, the housing is a hollow cylindrical structure, one end of the housing is connected to the valve seat, the rod-shaped portion of the valve seat is tightly fitted with the wall surface of the housing, a through hole is opened in the rod-shaped portion of the valve seat, a locking nut is connected to the housing by threading and is tightly fitted with the valve seat, a cylindrical piezoelectric ceramic stack is placed and assembled in the housing, one end of the piezoelectric ceramic stack is fitted with the inner wall of the housing, the other end of the piezoelectric ceramic stack is fitted with the end face of the circular plate-shaped structure of the flat spring valve stem, the flat spring valve stem has a rod-shaped structure in the middle and a circular plate-shaped structure at one end, the rod-shaped portion of the valve seat is pressed tightly with the rod-shaped portion of the flat spring valve stem to achieve sealing, and the medium inlet is connected to one end of the housing. Its beneficial effect is that the piezoelectric ceramics in the invention control deformation of 0 to 20 μm, and micron-level deformation makes micro-flow regulation possible, achieving a valve control accuracy of 0.5%.

Description

Technical Field

[0001] The invention belongs to a flow regulating valve, and in particular relates to a controllable and adjustable high-precision micro-flow valve. Background Art

[0002] There are many gas flow regulating valves, whose main function is to control and regulate the medium gas flow. To achieve this purpose, the flow regulating valve is generally designed as a valve stem and valve seat switch type, and various drive technologies are used to realize the valve stem and valve seat opening and closing at different degrees to achieve gas flow regulation.

[0003] High-precision and extremely small flow controllability of the medium is the development direction of regulating valves. Currently, existing flow control valves are generally adjusted manually or by electromagnetic coil drive, and the minimum flow range of the target medium is limited, generally at the SLM (standard liters per minute) level, and the control accuracy is 1% or lower. Summary of the invention

[0004] The purpose of the present invention is to provide a high-precision micro-flow regulating valve, which can effectively meet the effective regulation of medium gas within the range of 0 to 30 SCCM and 0.5% control accuracy, and provide assistance for special purposes (such as micro-flow medical gas supply control, aviation micro-flow gas drive, etc.).

[0005] The technical solution of the present invention is as follows: a high-precision micro-flow regulating valve, comprising a shell, the shell is a hollow cylindrical structure, one end of the shell is connected to the valve seat, the rod-shaped portion of the valve seat is tightly fitted with the wall surface of the shell, a through hole is opened in the rod-shaped portion of the valve seat, a locking nut is connected to the shell by a thread and is tightly fitted with the valve seat, a cylindrical piezoelectric ceramic stack is placed and assembled in the shell, one end of the piezoelectric ceramic stack is fitted with the inner wall of the shell, the other end of the piezoelectric ceramic stack is fitted with the end face of the circular plate structure of the flat spring valve stem, the flat spring valve stem has a rod-shaped structure in the middle and a circular plate-shaped structure at one end, the rod-shaped portion of the valve seat is fitted and pressed with the rod-shaped portion of the flat spring valve stem to achieve sealing, and the medium inlet is connected to one end of the shell.

[0006] The through hole of the valve seat is in the shape of a Rafale nozzle, and a cavity is formed at the head of the valve seat, the diameter of which is greater than the diameter of the through hole of the rod-shaped portion.

[0007] A through hole having the same diameter as the cavity of the head of the valve seat is opened in the middle of the locking nut.

[0008] The piezoelectric ceramic stack is positively welded to the positive electrode welding piece through the piezoelectric ceramic positive electrode cable, and the positive electrode welding piece leads the positive electrode out of the shell through the positive electrode lead-out cable.

[0009] The piezoelectric ceramic stack is welded to the negative electrode welding piece through a piezoelectric ceramic negative electrode cable, and the negative electrode welding piece leads the negative electrode out of the valve body through a negative electrode lead-out cable.

[0010] The positive electrode wire seal is installed and connected with the shell by interference fit, and the positive electrode wire seal is installed and connected with the positive electrode welding piece by interference fit.

[0011] The negative electrode wire seal is installed and connected with the shell by interference fit, and the negative electrode wire seal is installed and connected with the negative electrode welding piece by interference fit.

[0012] A vent hole is provided on the circular plate structure of the flat spring valve stem.

[0013] The vent holes include four groups, and the four groups of vent holes are evenly distributed on the circular plate structure of the flat spring valve stem.

[0014] Each group of ventilation holes comprises three holes, and the three holes are enlarged in sequence from the inside to the outside.

[0015] The beneficial effects of the present invention are:

[0016] 1) The micro-flow regulating valve is controllable and adjustable at 0-30 SCCM. The piezoelectric ceramics in the present invention control the deformation amount to be 0-20 μm. Micron-level deformation makes micro-flow regulation possible;

[0017] 2) A 0.5% control accuracy adjustment of the micro-flow regulating valve is achieved. In the present invention, the minimum resolution of the voltage-controlled piezoelectric ceramic deformation reaches 0.1 μm, achieving a 0.5% control accuracy of the valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is an appearance diagram of a high-precision micro-flow regulating valve provided by the present invention;

[0019] Figure 2 This is an internal structure diagram of a high-precision micro-flow regulating valve provided by the present invention;

[0020] Figure 3 It is a side view of the flat spring valve stem.

[0021] In the figure, 1 is a medium inlet assembly, 2 is a flat spring valve stem, 3 is a piezoelectric ceramic stack, 4 is a valve seat, 5 is a locking nut, 6 is a shell, 7 is a negative electrode wire seal, 8 is a negative electrode welding part, 9 is a positive electrode wire seal, 10 is a positive electrode welding part, 11 is a piezoelectric ceramic positive electrode cable, 12 is a positive electrode lead-out cable, 13 is a piezoelectric ceramic negative electrode cable, 14 is a negative electrode lead-out cable, and 15 is a vent. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0023] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, in the description of the present invention, "first", "second", "third", "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0024] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection, a mechanical connection, an electrical connection, a direct connection, or a connection through an intermediate medium, or the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. The meaning of "multiple" in the present invention is two or more, unless otherwise clearly and specifically limited.

[0025] like Figure 2 As shown, a high-precision micro-flow regulating valve includes a housing 6, which is the main structure of the valve, and the outlet end of the housing 6 (such as Figure 2 The left end of the housing 6 is closed and has an opening in the middle. Figure 2 The right end shown in the figure is an open structure, the middle of the shell 6 is a hollow cylindrical structure, and two through holes (such as Figure 2 The bolt-shaped valve seat 4 is connected to the outlet end of the shell 6 by threads, the rod-shaped portion of the valve seat 4 is tightly fitted with the wall of the shell 6, and a through hole is opened in the rod-shaped portion of the valve seat 4, and the through hole is in the shape of a Rafale nozzle. The head of the valve seat 4 is provided with a cavity, and the diameter of the cavity is larger than the diameter of the through hole of the rod-shaped portion. The locking nut 5 is connected to the outlet end of the shell 6 by threads and is tightly attached to the valve seat 4, so that the parts will not loosen. The middle of the locking nut 5 is also provided with a through hole with the same diameter as the cavity of the head of the valve seat 4. The cylindrical piezoelectric ceramic stack 3 is arranged in the cavity of the shell 6, and one end of the piezoelectric ceramic stack 3 (as shown in FIG. Figure 2 The left end as shown in FIG. 1 is in contact with the inner wall of the housing 6, and the other end of the piezoelectric ceramic stack 3 (as shown in FIG. Figure 2The right end shown in the figure is fitted with the end face of the circular plate structure of the flat spring valve stem 2. The flat spring valve stem 2 has a rod-like structure in the middle and a circular plate-like structure at one end. The circular plate-like structure also has an annular flange, and the flange wraps the piezoelectric ceramic stack 3 inside. Figure 3 As shown, the circular plate structure of the flat spring valve stem 2 is provided with air holes 15, and the air holes include four groups. The four groups of air holes are evenly distributed on the circular plate structure of the flat spring valve stem 2. Each group of air holes 15 includes three holes, and the three holes increase in size from the inside to the outside. The flat spring valve stem 2 is made of a compressible material. The air holes can effectively guide the intake air to the outlet end. At the same time, the air holes 15 can better realize the compression deformation of the circular plate structure of the flat spring valve stem 2, so that the deformation of the circular plate structure of the flat spring valve stem 2 is large enough to meet the requirements for medium gas flow control. The rod-shaped portion of the valve seat 4 is pressed against the rod-shaped portion of the flat spring valve stem 2 to achieve sealing. The medium inlet assembly 1 is connected to the shell 6 by threads, and the medium inlet assembly 1 presses the circular plate structure of the flat spring rod 2.

[0026] like Figure 2 As shown, one side of the piezoelectric ceramic stack 3 (such as Figure 2 The positive electrode of the piezoelectric ceramic stack 3 is welded to the positive electrode welding piece 10 through the piezoelectric ceramic positive electrode cable 11, and the positive electrode welding piece 10 leads the positive electrode out of the housing 6 through the positive electrode lead-out cable 12; one side of the piezoelectric ceramic stack 3 (as shown in FIG. Figure 2 The lower side shown in the figure) is welded to the negative electrode welding piece 8 through the piezoelectric ceramic negative electrode cable 13, and the negative electrode welding piece 8 leads the negative electrode out of the valve body through the negative electrode lead-out cable 14.

[0027] like Figure 2 As shown, the positive electrode wire seal 9 and the positive electrode welding part 10 are installed and connected by interference fit, and the positive electrode wire seal 9 and the shell 6 are installed and connected by interference fit; the negative electrode wire seal 7 and the negative electrode welding part 8 are installed and connected by interference fit, and the negative electrode wire seal 7 and the shell 6 are installed and connected by interference fit.

[0028] The working process of the present invention is as follows:

[0029] like Figure 2 As shown in the flow direction of the medium gas, the medium gas enters the valve cavity from the medium inlet assembly 1, passes through the vent hole on the flat spring valve stem 2, passes through the flow channel between the piezoelectric ceramic stack 3 and the flat spring valve stem 2, and enters the sealed front end of the flat spring valve stem 2 and the valve seat 4. When the valve needs to work, the piezoelectric ceramic is powered, and the piezoelectric ceramic is axially expanded and contracted, thereby compressing or restoring the circular plate structure of the moving flat spring valve stem 2. When the circular plate structure of the flat spring valve stem 2 is compressed, the rod-shaped part of the flat spring valve stem 2 is separated from the sealing surface to open the flow channel, and the medium gas flows out of the valve outside through the flow channel.

[0030] Different supply voltages are used to achieve different piezoelectric ceramic deformations, thereby achieving different valve openings, and further achieving the supply of medium gases with different pressures and flow rates.

[0031] This valve is driven by piezoelectric ceramics and has a reasonable structural design, so that the target medium flow range can reach the SCCM (standard milliliters per minute) level and the control accuracy can reach 0.5%.

[0032] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-precision micro-flow regulating valve, characterized in that: The utility model comprises a shell, which is a hollow cylindrical structure, one end of the shell is connected to the valve seat, the rod-shaped part of the valve seat is tightly fitted with the wall surface of the shell, a through hole is opened in the rod-shaped part of the valve seat, a locking nut is connected to the shell by a thread and is tightly fitted with the valve seat, a cylindrical piezoelectric ceramic stack is placed and assembled in the shell, one end of the piezoelectric ceramic stack is fitted with the inner wall of the shell, the other end of the piezoelectric ceramic stack is fitted with the end surface of the circular plate-shaped structure of the flat spring valve stem, the flat spring valve stem has a rod-shaped structure in the middle, one end of the flat spring valve stem has a circular plate-shaped structure, the rod-shaped part of the valve seat is fitted and pressed with the rod-shaped part of the flat spring valve stem to achieve sealing, and the medium inlet is connected to one end of the shell; The through hole of the valve seat is in the shape of a Rafale nozzle, and a cavity is formed at the head of the valve seat, the diameter of which is larger than the diameter of the through hole of the rod-shaped portion; A through hole having the same diameter as the cavity of the head of the valve seat is opened in the middle of the locking nut; The circular plate structure of the flat spring valve stem is provided with a vent hole; The vent holes include four groups, and the four groups of vent holes are evenly distributed on the circular plate structure of the flat spring valve stem; Each set of ventilation holes includes three holes, and the three holes increase in size from the inside to the outside.

2. A high-precision micro-flow regulating valve as claimed in claim 1, characterized in that: The piezoelectric ceramic stack is positively welded to the positive electrode welding piece through the piezoelectric ceramic positive electrode cable, and the positive electrode welding piece leads the positive electrode out of the shell through the positive electrode lead-out cable.

3. A high-precision micro-flow regulating valve as claimed in claim 2, characterized in that: The piezoelectric ceramic stack is welded to the negative electrode welding piece through a piezoelectric ceramic negative electrode cable, and the negative electrode welding piece leads the negative electrode out of the shell through a negative electrode lead-out cable.

4. A high-precision micro-flow regulating valve as claimed in claim 3, characterized in that: The positive electrode wire seal and the shell are installed with interference fit, and the positive electrode wire seal and the positive electrode welding part are installed with interference fit.

5. A high-precision micro-flow regulating valve as claimed in claim 4, characterized in that: The negative electrode wire seal and the shell are installed with interference fit, and the negative electrode wire seal and the negative electrode welding part are installed with interference fit.

Images