阅读说明：本技术 一种流量计型自调节平衡阀及其流量自调节方法 (Flowmeter type self-adjusting balance valve and flow self-adjusting method thereof ) 是由 王朝阳 林方杰 杨月红 吕强 祝云霞 徐东荣 于 2020-07-27 设计创作，主要内容包括：本发明公开了一种流量计型自调节平衡阀及其流量自调节方法,包括阀体,阀体内安装有球阀和阀杆,阀杆与电机相连,电机与控制器相连,还包括进液通道、流量计通道和出液通道。进液通道内设有活塞杆,活塞杆上套设有复位弹簧,活塞杆内端设有活塞,活塞杆外端伸出进液通道连接有拉环；流量计通道通过通道入口与进液通道连通,流量计通道内设有弹簧和浮子,浮子上设有磁铁；刻度调节装置设在流量计通道外侧,刻度调节装置内设有磁性接近开关,磁性接近开关与所述控制器相连,移动槽外侧设有流量指示的刻度；还包括出液通道。本发明的流量计型自调节平衡阀能够准确自动调节流量,具有结构简单,读数直接,可实时调节等优点。(The invention discloses a flowmeter type self-adjusting balance valve and a flow self-adjusting method thereof. A piston rod is arranged in the liquid inlet channel, a return spring is sleeved on the piston rod, a piston is arranged at the inner end of the piston rod, and the outer end of the piston rod extends out of the liquid inlet channel and is connected with a pull ring; the flow meter channel is communicated with the liquid inlet channel through a channel inlet, a spring and a floater are arranged in the flow meter channel, and a magnet is arranged on the floater; the scale adjusting device is arranged on the outer side of the flow meter channel, a magnetic proximity switch is arranged in the scale adjusting device, the magnetic proximity switch is connected with the controller, and scales for indicating flow are arranged on the outer side of the moving groove; also comprises a liquid outlet channel. The flowmeter type self-adjusting balance valve can accurately and automatically adjust the flow, and has the advantages of simple structure, direct reading, real-time adjustment and the like.)

1. The utility model provides a flowmeter type self-interacting balanced valve, includes the valve body, installs ball valve and valve rod in the valve body, its characterized in that, the valve rod links to each other with the motor, and the motor links to each other with the controller, and it still includes: the liquid inlet channel is communicated with the valve body, a piston rod is arranged in the liquid inlet channel, a return spring is sleeved on the piston rod, a piston is arranged at the inner end of the piston rod, and the outer end of the piston rod extends out of the liquid inlet channel and is connected with a pull rod;

the flowmeter channel is communicated with the liquid inlet channel through a channel inlet, a spring and a floater are arranged in the flowmeter channel, the floater abuts against the channel inlet under the action of the spring, and a magnet is arranged on the floater;

the scale adjusting device is arranged on the outer side of the flow meter channel, a moving groove is formed in the scale adjusting device, a magnetic proximity switch is arranged in the moving groove and connected with the controller, and scales for flow indication are arranged on the outer side of the moving groove;

and the two ends of the liquid outlet channel are respectively communicated with the flow meter channel and the valve body.

2. The flow meter type self-adjusting balance valve according to claim 1, wherein a piston seat is provided in the inlet passage, and in a normal state, the return spring compresses the piston rod to make the piston seal the piston seat, the inlet passage is closed, and when the piston rod is moved by pulling the pull rod, the piston is separated from the piston seat, and the inlet passage is opened.

3. The flowmeter type self-adjusting balance valve of claim 2, wherein the outer end of the piston rod is provided with a rotating shaft, the pull rod is provided with a limiting pull piece, the limiting pull piece is rotatably mounted on the rotating shaft, the limiting pull piece is provided with a first limiting section and a second limiting section, and the thickness of the second limiting section is greater than that of the first limiting section; when the limiting pull piece is rotated to enable the first limiting section to be located in the rotating shaft, the piston seals the piston valve seat under the action of the spring, and the liquid inlet channel is closed; when the second spacing section is positioned in the rotating shaft by rotating the spacing pulling piece, the piston leaves the piston valve seat, the liquid inlet channel is opened, and a fixed opening degree is kept.

4. The flowmeter type self-adjusting balance valve of claim 2, wherein the outer end of the piston rod is provided with a rotating shaft, the pull rod is provided with a limiting pull piece, the limiting pull piece is rotatably mounted on the rotating shaft, the limiting pull piece is provided with a first limiting section, a second limiting section and a third limiting section, wherein the thickness of the third limiting section is larger than that of the second limiting section; when the limiting pull piece is rotated to enable the first limiting section to be located in the rotating shaft, the piston seals the piston valve seat under the action of the spring, and the liquid inlet channel is closed; when the limiting pull piece is rotated to enable the second limiting section to be located in the rotating shaft, the piston leaves the piston valve seat to a first stroke, the liquid inlet channel is opened, and a first fixed opening degree is kept; when the third limiting section is positioned in the rotating shaft by rotating the limiting pulling piece, the piston leaves the piston valve seat to a second stroke, the liquid inlet channel is opened, and a second fixed opening degree is kept, wherein the second fixed opening degree is larger than the first fixed opening degree.

5. The flow meter type self-adjusting balance valve of claim 4, wherein a first scale corresponding to a first fixed opening degree and a second scale corresponding to a second fixed opening degree are provided outside the moving groove.

6. A method of self-regulating the flow of a flow meter type self-regulating balancing valve according to claim 1 or 2, characterized by the steps of:

(1) moving the magnetic proximity switch to a flow scale required to be balanced, and fixing the magnetic proximity switch;

(2) the pull rod is adjusted to enable liquid in the valve body to enter the flow meter channel through the liquid inlet channel and return to the valve body through the liquid outlet channel;

(3) the floater moves upwards under the double actions of the liquid and the spring until the floater is in a stable state;

(4) the magnetic proximity switch starts to work;

(5) keeping the state of the step (2), the controller instructs the motor to drive the valve rod, so as to adjust the opening of the ball valve, change the liquid flow in the valve body, change the flow of the liquid flowing into the flow meter channel and change the moving position of the floater;

(6) when the floater moves to be close to the magnetic proximity switch, the magnetic proximity switch triggers an instruction to be transmitted to the controller, the controller instructs the motor to stop adjusting the valve rod, and the flow is adjusted;

(7) and after the flow is adjusted, adjusting the pull rod to an initial state.

7. A method of flow self-regulation of a flow meter type self-regulating balancing valve according to claim 3, characterized by the steps of claim 6, replacing step (2) with:

(2) the limiting pull piece is rotated to enable the second limiting section to be located in the rotating shaft, the piston leaves the piston valve seat, the liquid inlet channel is opened and keeps a fixed opening degree, and liquid in the valve body enters the flow meter channel through the liquid inlet channel and returns to the valve body through the liquid outlet channel;

replacing step (7) with:

(7) after the flow regulation is finished, the first limiting section is located in the rotating shaft by rotating the limiting pulling piece, the piston seals the piston valve seat under the action of the spring, and the liquid inlet channel is closed.

8. The flow self-adjusting method of a flow meter type self-adjusting balance valve according to claim 4 or 5, characterized by the steps of claim 6, replacing step (2) with:

(2) when the liquid flow in the valve body is large:

the second limiting section is positioned in the rotating shaft by rotating the limiting pulling piece, the piston leaves the piston valve seat to a first stroke, the liquid inlet channel is opened and keeps a first fixed opening, and liquid in the valve body enters the flow meter channel through the liquid inlet channel at a smaller flow rate and returns to the valve body through the liquid outlet channel;

when the liquid flow in the valve body is small:

the third limiting section is positioned in the rotating shaft by rotating the limiting pulling piece, the piston leaves the piston valve seat to a second stroke, the liquid inlet channel is opened and keeps a second fixed opening degree, and the liquid in the valve body enters the flow meter channel through the liquid inlet channel at a larger flow rate and returns to the valve body through the liquid outlet channel;

replacing step (7) with:

(7) after the flow regulation is finished, the first limiting section is located in the rotating shaft by rotating the limiting pulling piece, the piston seals the piston valve seat under the action of the spring, and the liquid inlet channel is closed.

Technical Field

The invention relates to the technical field of valves, in particular to a flow meter type self-adjusting balance valve and a flow self-adjusting method thereof.

Background

The balance valve is a valve which plays a role in dynamic and static balance adjustment under the hydraulic working condition. Balanced valves can be divided into three types: static balance valves, dynamic balance valves, and differential pressure independent balance valves. The balance valve can reasonably distribute flow, and effectively solves the problem of uneven room temperature in a heat supply (air conditioning) system.

The utility model discloses a 201220404591.5 discloses a flow balance valve, it includes balanced valve 1 and flowmeter 2, a serial communication port, balanced valve 1 and flowmeter 2 formula as an organic whole, flowmeter 2 establish the stomach in balanced valve 1's valve body, be provided with observation window 11 on balanced valve 1's the valve body, the utility model has the advantages of, can reduce circulation system installation interface, the guarantee pipeline wholeness simultaneously, reduce piping erection work volume, reduce the installation cost, moreover, the inside floater of instructing the flow of flowmeter not with circulation medium direct contact, make the flow floater remain clean all the time, do not receive the influence of any quality of water, the flow value reads more accurately.

Disclosure of Invention

The invention provides a flowmeter type self-regulating balance valve without a flowmeter arranged in a valve body and an accurate flow self-regulating method, so as to realize the flow self-regulating method which can accurately regulate the flow of the valve body without the influence of the flowmeter on the flow of liquid in the valve body.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a flowmeter type self-interacting balanced valve, includes the valve body, installs ball valve and valve rod in the valve body, its characterized in that, the valve rod links to each other with the motor, and the motor links to each other with the controller, and it still includes: the liquid inlet channel is communicated with the valve body, a piston rod is arranged in the liquid inlet channel, a return spring is sleeved on the piston rod, a piston is arranged at the inner end of the piston rod, and the outer end of the piston rod extends out of the liquid inlet channel and is connected with a pull rod; the flowmeter channel is communicated with the liquid inlet channel through a channel inlet, a spring and a floater are arranged in the flowmeter channel, the floater abuts against the channel inlet under the action of the spring, and a magnet is arranged on the floater; the scale adjusting device is arranged on the outer side of the flow meter channel, a moving groove is formed in the scale adjusting device, a magnetic proximity switch is arranged in the moving groove and connected with the controller, and scales for flow indication are arranged on the outer side of the moving groove; and the two ends of the liquid outlet channel are respectively communicated with the flow meter channel and the valve body.

Optionally, a piston valve seat is arranged in the liquid inlet channel, in a normal state, the return spring compresses the piston rod to enable the piston to seal the piston valve seat, the liquid inlet channel is closed, when the pull rod is pulled to enable the piston rod to move, the piston is separated from the piston valve seat, and the liquid inlet channel is opened.

Optionally, a rotating shaft is arranged at the outer end of the piston rod, a limiting pulling piece is arranged on the pull rod, the limiting pulling piece is rotatably mounted on the rotating shaft, a first limiting section and a second limiting section are arranged on the limiting pulling piece, and the thickness of the second limiting section is greater than that of the first limiting section; when the limiting pull piece is rotated to enable the first limiting section to be located in the rotating shaft, the piston seals the piston valve seat under the action of the spring, and the liquid inlet channel is closed; when the second spacing section is positioned in the rotating shaft by rotating the spacing pulling piece, the piston leaves the piston valve seat, the liquid inlet channel is opened, and a fixed opening degree is kept.

Optionally, a rotating shaft is arranged at the outer end of the piston rod, the pull rod is provided with a limiting pull piece, the limiting pull piece is rotatably mounted on the rotating shaft, and a first limiting section, a second limiting section and a third limiting section are arranged on the limiting pull piece, wherein the thickness of the third limiting section is greater than that of the second limiting section; when the limiting pull piece is rotated to enable the first limiting section to be located in the rotating shaft, the piston seals the piston valve seat under the action of the spring, and the liquid inlet channel is closed; when the limiting pull piece is rotated to enable the second limiting section to be located in the rotating shaft, the piston leaves the piston valve seat to a first stroke, the liquid inlet channel is opened, and a first fixed opening degree is kept; when the third limiting section is positioned in the rotating shaft by rotating the limiting pulling piece, the piston leaves the piston valve seat to a second stroke, the liquid inlet channel is opened, and a second fixed opening degree is kept, wherein the second fixed opening degree is larger than the first fixed opening degree.

Optionally, a first scale corresponding to the first fixed opening degree and a second scale corresponding to the second fixed opening degree are arranged outside the moving groove.

The flow self-adjusting method of the flowmeter type self-adjusting balance valve is characterized by comprising the following steps of:

(1) moving the magnetic proximity switch to a flow scale required to be balanced, and fixing the magnetic proximity switch;

(2) the pull rod is adjusted to enable liquid in the valve body to enter the flow meter channel through the liquid inlet channel and return to the valve body through the liquid outlet channel;

(3) the floater moves upwards under the double actions of the liquid and the spring until the floater is in a stable state;

(4) the magnetic proximity switch starts to work;

(5) keeping the state of the step (2), the controller instructs the motor to drive the valve rod, so as to adjust the opening of the ball valve, change the liquid flow in the valve body, change the flow of the liquid flowing into the flow meter channel and change the moving position of the floater;

(6) when the floater moves to be close to the magnetic proximity switch, the magnetic proximity switch triggers an instruction to be transmitted to the controller, the controller instructs the motor to stop adjusting the valve rod, and the flow is adjusted;

(7) and after the flow is adjusted, adjusting the pull rod to an initial state.

The flow self-adjusting method of the flowmeter type self-adjusting balance valve replaces the step (2) with the following steps:

(2) the limiting pull piece is rotated to enable the second limiting section to be located in the rotating shaft, the piston leaves the piston valve seat, the liquid inlet channel is opened and keeps a fixed opening degree, and liquid in the valve body enters the flow meter channel through the liquid inlet channel and returns to the valve body through the liquid outlet channel;

replacing step (7) with:

(7) after the flow regulation is finished, the first limiting section is located in the rotating shaft by rotating the limiting pulling piece, the piston seals the piston valve seat under the action of the spring, and the liquid inlet channel is closed.

The flow self-adjusting method of the flowmeter type self-adjusting balance valve replaces the step (2) with the following steps:

(2) when the liquid flow in the valve body is large:

the second limiting section is positioned in the rotating shaft by rotating the limiting pulling piece, the piston leaves the piston valve seat to a first stroke, the liquid inlet channel is opened and keeps a first fixed opening, and liquid in the valve body enters the flow meter channel through the liquid inlet channel at a smaller flow rate and returns to the valve body through the liquid outlet channel;

when the liquid flow in the valve body is small:

the third limiting section is positioned in the rotating shaft by rotating the limiting pulling piece, the piston leaves the piston valve seat to a second stroke, the liquid inlet channel is opened and keeps a second fixed opening degree, and the liquid in the valve body enters the flow meter channel through the liquid inlet channel at a larger flow rate and returns to the valve body through the liquid outlet channel;

replacing step (7) with:

(7) after the flow regulation is finished, the first limiting section is located in the rotating shaft by rotating the limiting pulling piece, the piston seals the piston valve seat under the action of the spring, and the liquid inlet channel is closed.

The technical scheme of the invention also comprises a large-range flowmeter which comprises a shell arranged on the infusion pipeline, wherein a bypass channel of the infusion pipeline is formed in the shell, the bypass channel comprises a liquid inlet channel, a measuring channel and a liquid outlet channel which are sequentially connected, and the liquid inlet channel is connected with the measuring channel through a channel inlet; a spring and a floater are arranged in the measuring channel, and the floater is propped against the inlet of the channel under the action of the spring; a piston valve seat and a piston rod are arranged in the liquid inlet channel, a return spring is sleeved on the piston rod, a piston is arranged on the piston rod, and in an initial state, the return spring compresses the piston rod to enable the piston to seal the piston valve seat, so that the liquid inlet channel is closed; the device also comprises an opening control mechanism for driving the piston rod to move, wherein the opening control mechanism drives the piston rod to generate at least two stroke changes from an initial state: when the piston rod moves to enable the piston to leave the piston valve seat to a first stroke, the liquid inlet channel is opened and keeps a first fixed opening degree; when the piston rod moves to enable the piston to leave the piston valve seat to a second stroke, the liquid inlet channel is opened and a second fixed opening degree is kept.

Optionally, the device further comprises a scale display device, and a first scale corresponding to the first fixed opening degree and a second scale corresponding to the second fixed opening degree are arranged on the outer side of the scale display device.

Optionally, a magnet is arranged on the float, a chute is arranged in the scale display device, a floating ball adsorbed by the magnet is arranged in the chute, and the first scale and the second scale correspond to the floating ball.

Optionally, the opening degree control mechanism includes:

a rotating shaft is arranged at the outer end of the piston rod, which extends out of the liquid inlet channel, and a pull rod is arranged on the rotating shaft; the pull rod is provided with a limiting pull piece, the limiting pull piece is rotatably installed on the rotating shaft, and the limiting pull piece is provided with a first limiting section, a second limiting section and a third limiting section, wherein the thickness of the third limiting section is greater than that of the second limiting section and greater than that of the first limiting section; when the limiting pull piece is rotated to enable the first limiting section to be located in the rotating shaft, the piston seals the piston valve seat under the action of the spring, and the liquid inlet channel is closed; when the limiting pull piece is rotated to enable the second limiting section to be located in the rotating shaft, the piston leaves the piston valve seat to a first stroke, the liquid inlet channel is opened, and a first fixed opening degree is kept; when the third limiting section is positioned in the rotating shaft by rotating the limiting pulling piece, the piston leaves the piston valve seat to a second stroke, the liquid inlet channel is opened, and a second fixed opening degree is kept, wherein the second fixed opening degree is larger than the first fixed opening degree.

Optionally, the opening degree control mechanism includes:

the inner end of the piston is provided with a pressure sensor, the piston rod is connected with a motor, the motor is connected with a controller, and the controller is connected with a switch and the pressure sensor; when the switch is turned on, the controller obtains water pressure information of the pressure sensor, when the water pressure information is within a first preset value interval, the motor drives the piston rod to move, the piston is enabled to leave the piston valve seat to reach a first stroke, the liquid inlet channel is opened, and a first fixed opening degree is kept; when the water pressure information is within a second preset value interval, the motor drives the piston rod to move, so that the piston leaves the piston valve seat to a second stroke, the liquid inlet channel is opened, and a second fixed opening degree is maintained, wherein the second fixed opening degree is larger than the first fixed opening degree.

The method for measuring the large-range flow of the large-range flowmeter comprises the following steps:

(1) when the flow needs to be measured, the opening control mechanism drives the piston rod to move, so that the piston is separated from the piston valve seat, when the flow of liquid in the infusion pipeline is large, the piston rod is driven to move, so that the piston is separated to a first stroke, the liquid inlet channel is opened, a first fixed opening is kept, and the liquid enters the measuring channel through the liquid inlet channel at a small flow; when the liquid flow in the liquid conveying pipeline is larger, the piston rod is driven to move, the piston is enabled to move to a second stroke, the liquid inlet channel is opened, a second fixed opening degree is kept, and the liquid in the valve body enters the measuring channel through the liquid inlet channel at a larger flow;

(2) obtaining flow data corresponding to the floater;

(3) the opening control mechanism drives the piston rod to move to an initial state, namely, the return spring compresses the piston rod to enable the piston to seal the piston valve seat, and the liquid inlet channel is closed.

The invention has the beneficial effects that:

the flowmeter type self-adjusting balance valve can accurately and automatically adjust the flow, and has the advantages of simple structure, direct reading, real-time adjustment and the like.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic diagram of the construction of a flow meter type self-regulating balancing valve of the present invention;

FIG. 2 is a schematic view of the construction of the scale adjustment mechanism portion of the present invention;

FIG. 3 is an enlarged view of a portion of the tie bar of the present invention;

FIG. 4 is a schematic view of the structure of the tie bar of the present invention;

fig. 5 is a schematic control flow diagram of an automated wide-range flow meter embodying the present invention.

Description of reference numerals:

a valve body 1; a ball valve 11; a valve stem 12; a liquid inlet channel 2; a piston valve seat 21; a piston rod 22; a rotating shaft 221; a return spring 23; a piston 24; a pull rod 25; a limit puller 251; a first restraint section 252; a second stopper 253; a third spacing segment 254; a flow meter channel 3; a channel inlet 31; a spring 32; a float 33; a magnet 34; a scale adjustment device 4; a moving groove 41; a magnetic proximity switch 42; a transparent window 43; a scale 44; a liquid outlet channel 5; a motor 6; and a controller 7.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.

As shown in fig. 1 to 3, a flowmeter type self-adjusting balance valve includes a valve body 1, and a ball valve 11 and a valve stem 12 are installed in the valve body 1. Wherein the valve stem 12 is connected to the motor 6 and the motor 6 is connected to the controller 7.

This balanced valve is still including installing the casing outside valve body 1, is equipped with inlet channel 2, flowmeter passageway 3 and the liquid outlet channel 5 that communicate in proper order in the casing, and inlet channel 2 and liquid outlet channel 5 all link to each other with valve body 1.

Flowmeter passageway 3 includes the passageway that is formed by the flowmeter casing in this structure, and 3 one ends of flowmeter passageway are equipped with the float valve seat, and the float valve seat is equipped with passageway entry 31 and inlet channel 2 intercommunication. A spring 32 and a floater 33 are arranged in the flow meter channel 3, the floater 33 is abutted against the channel inlet 31 under the action of the spring 32, and a magnet 34 is arranged on the floater 33. A scale adjustment device 4 is arranged outside the flowmeter housing. A moving groove 41 is provided in the scale adjustment device 4, and a magnetic proximity switch 42 that engages with the magnet 34 is provided in the moving groove 41. The scale adjustment device 4 is provided with a scale 44 for indicating the flow rate outside the moving groove 41, and a transparent window 43 outside the moving groove 41 so as to observe the position of the magnetic proximity switch 42 and read the corresponding scale 44. The magnetic proximity switch 42 is connected to the controller 7.

In the structure, a piston valve seat 21 and a piston rod 22 are arranged in the liquid inlet channel 2, a return spring 23 is sleeved on the piston rod 22, a piston 24 is arranged at the inner end of the piston rod 22, and a pull rod 25 is connected to the outer end of the piston rod 22, which extends out of the shell (the liquid inlet channel 2). In an initial state (normal state), the return spring 23 compresses the piston rod 22 to enable the piston 24 to seal the piston valve seat 21, the liquid inlet channel 2 is closed, and when the pull rod 25 is pulled to enable the piston rod 22 to move, the piston 24 is separated from the piston valve seat 21, and the liquid inlet channel 2 is opened. This structure is through opening inlet channel 2, can read out the flow that the flowmeter shows when flow control, and through closing inlet channel 2, flow control finishes the back, and inside spring 32 self return closes piston 24, and liquid no longer passes through the flowmeter. It should be noted that, during flow rate adjustment, the liquid in the valve body 1 flows through the main channel and the bypass channel (the liquid inlet channel 2, the flow meter channel 3, and the liquid outlet channel 5) of the valve body 1 at the same time, so that the flow rate measured by the flow meter is not the actual flow rate of the liquid in the valve body 1, and it is necessary to identify the scale 44 representing the flow rate of the liquid in the valve body 1 after conversion according to experience.

As an example of the present embodiment, the outer end of the piston rod 22 is provided with a rotating shaft 221, the pull rod 25 is provided with a limiting pull member 251, and the limiting pull member 251 is rotatably mounted on the rotating shaft 221. The limiting pulling piece 251 is provided with a first limiting section 252 and a second limiting section 253, wherein the thickness of the second limiting section 253 is larger than that of the first limiting section 252; when the limiting pull piece 251 is rotated to enable the first limiting section 252 to be positioned in the rotating shaft 221, the piston 24 seals the piston valve seat 21 under the action of the spring 32, and the liquid inlet channel 2 is closed; when the second stopper 253 is located in the rotary shaft 221 by rotating the stopper drawing member 251, the piston 24 is separated from the piston valve seat 21, and the liquid inlet passage 2 is opened and maintained at a fixed opening. If the piston 24 is positioned differently, the flow into the meter will be different, and therefore the meter indications of different opening degrees will not be consistent. If the piston rod 22 cannot be positioned: (1) in the same flow measurement process, it is difficult to always protect the same opening, and at the same time, due to the existence of the return spring 23, it is also difficult to maintain the maximum opening; (2) in the flow measurement process of different times, it is more difficult to keep the opening degrees of the two times consistent.

In addition, as a second example of the present embodiment, it is a manual type wide range flow meter. Since less liquid enters the flow meter through the bypass in the valve body 1 and thus less liquid enters the flow meter channel 3, the spring 32 and the float 33 need to be arranged more sensitively, and a smaller flow change causes a larger moving distance of the float 33, increasing the sensitivity of the float 33. However, the large sensitivity and the large measuring range are conflicting because of the limited travel of the float 33. To overcome this technical problem, the present example adopts the following structure:

as shown in fig. 4, the outer end of the piston rod 22 is provided with a rotating shaft 221, the pull rod 25 is provided with a limiting pull member 251, the limiting pull member 251 is rotatably mounted on the rotating shaft 221, the limiting pull member 251 is provided with a first limiting section 252, a second limiting section 253 and a third limiting section 254, wherein the thickness of the third limiting section 254 is greater than the thickness of the second limiting section 253 than the thickness of the first limiting section 252. When the limiting pull piece 251 is rotated to enable the first limiting section 252 to be positioned in the rotating shaft 221, the piston 24 seals the piston valve seat 21 under the action of the spring 32, and the liquid inlet channel 2 is closed; when the limiting pull piece 251 is rotated to enable the second limiting section 253 to be positioned in the rotating shaft 221, the piston 24 leaves the piston valve seat 21 to a first stroke, the liquid inlet channel 2 is opened, and a first fixed opening degree is kept; when the third stopper section 254 is positioned in the rotary shaft 221 by rotating the stopper drawing member 251, the piston 24 leaves the piston valve seat 21 to a second stroke, the liquid inlet passage 2 is opened, and a second fixed opening degree is maintained, wherein the second fixed opening degree is greater than the first fixed opening degree. A first scale 44 corresponding to a first fixed opening degree and a second scale 44 corresponding to a second fixed opening degree are provided outside the moving groove 41.

With the above configuration, in the present example, when the liquid flow rate of the valve body 1 is large (expressed as a fast flow rate), the first fixed opening degree makes the liquid flow rate entering the flow meter passage 3 small, and therefore the flow meter indicates a corresponding measurement result in the case of a small flow rate and a high flow rate. Conversely, when the liquid flow rate of the valve body 1 is small (representing a low flow rate), the second fixed opening degree causes the liquid flow rate entering the flow meter channel 3 to be large, so that the flow meter indicates a corresponding measurement result under the condition of large flow rate and low flow rate. If the flow rate of the valve body 1 is 10, the pull rod 25 is adjusted to the second fixed opening degree, the measurement range of the flow meter is 1-10, and if the flow rate of the valve body 1 is 20, the pull rod is adjusted to the first fixed opening degree, and the measurement range of the flow meter is 11-20.

The flow self-adjusting method of the flowmeter type self-adjusting balance valve of the embodiment comprises the following steps:

(1) moving the magnetic proximity switch 42 to the flow scale for desired balance and securing the magnetic proximity switch 42;

(2) the pull rod 25 is adjusted to enable the liquid in the valve body 1 to enter the flow meter channel 3 through the liquid inlet channel and return to the valve body 1 through the liquid outlet channel 5;

(3) the float 33 moves upwards under the double action of the liquid and the spring 32 until the float 33 is in a stable state;

(4) the magnetic proximity switch 42 begins to operate;

(5) keeping the state of the step (2), the controller 7 instructs the motor 6 to drive the valve rod 12, so as to adjust the opening degree of the ball valve 11, so that the liquid flow in the valve body 1 is changed, the flow of the liquid flowing into the flow meter channel 3 is also changed, and the moving position of the floater 33 is also changed;

(6) when the floater 33 moves to be close to the magnetic proximity switch 42, the magnetic proximity switch 42 triggers an instruction to be transmitted to the controller 7, the controller 7 instructs the motor 6 to stop regulating the valve rod 12, and the flow regulation is finished;

(7) after the flow adjustment is completed, the pull rod 25 is adjusted to the initial state.

The flow self-regulating method of the flow meter type self-regulating balance valve in the first embodiment is the same as the above steps except that the step (1) is replaced by:

(1) the limiting pull piece 251 is rotated to enable the second limiting section 253 to be positioned in the rotating shaft 221, the piston 24 leaves the piston valve seat 21, the liquid inlet channel 2 is opened and keeps a fixed opening degree, and liquid in the valve body 1 enters the flow meter channel 3 through the liquid inlet channel 2 and returns to the valve body 1 through the liquid outlet channel 5;

replacing the step (5) with:

(5) after the flow rate is adjusted, the limiting pulling member 251 is rotated to make the first limiting section 252 located in the rotating shaft 221, the piston 24 seals the piston valve seat 21 under the action of the spring 32, and the liquid inlet channel 2 is closed.

The flow self-regulating method of the flow meter type self-regulating balance valve of the second embodiment is the same as the above steps except that the step (1) is replaced by:

(1) when the liquid flow in the valve body 1 is large:

the limiting pulling piece 251 is rotated to enable the second limiting section 253 to be positioned in the rotating shaft 221, the piston 24 leaves the piston valve seat 21 to a first stroke, the liquid inlet channel 2 is opened and keeps a first fixed opening degree, and liquid in the valve body 1 enters the flow meter channel 3 through the liquid inlet channel 2 at a smaller flow rate and returns to the valve body 1 through the liquid outlet channel 5;

when the liquid flow in the valve body 1 is small:

the third limiting section 254 is positioned in the rotating shaft 221 by rotating the limiting pull piece 251, the piston 24 leaves the piston valve seat 21 to a second stroke, the liquid inlet channel 2 is opened and keeps a second fixed opening degree, and the liquid in the valve body 1 enters the flow meter channel 3 through the liquid inlet channel 2 at a larger flow rate and returns to the valve body 1 through the liquid outlet channel 5;

replacing the step (5) with:

(5) after the flow rate is adjusted, the limiting pulling member 251 is rotated to make the first limiting section 252 located in the rotating shaft 221, the piston 24 seals the piston valve seat 21 under the action of the spring 32, and the liquid inlet channel 2 is closed.

In addition, the invention also provides an automatic large-range flowmeter, and the structures of the liquid inlet channel, the measuring channel, the liquid outlet channel and the like are the same as those of the manual large-range flowmeter.

The difference lies in an opening degree control mechanism comprising:

as shown in fig. 5, a pressure sensor is arranged at the inner end of the piston, the piston rod is connected with a motor, the motor is connected with a controller, and the controller is connected with a switch and the pressure sensor; when the switch is turned on, the controller obtains water pressure information of the pressure sensor, when the water pressure information is within a first preset value interval, the motor drives the piston rod to move, the piston is enabled to leave the piston valve seat to reach a first stroke, the liquid inlet channel is opened, and a first fixed opening degree is kept; when the water pressure information is within a second preset value interval, the motor drives the piston rod to move, so that the piston leaves the piston valve seat to a second stroke, the liquid inlet channel is opened, and a second fixed opening degree is maintained, wherein the second fixed opening degree is larger than the first fixed opening degree.

Meanwhile, the water pressure information can be set into a plurality of preset value intervals, and if a third preset value is distinguished and corresponds to a third fixed opening degree, the rest can be done in the same way.

The flowmeter can also be provided with a control panel for adjusting the numerical values of the first preset value interval and the second preset value interval.

The automatic large-range flow meter of the embodiment can automatically judge the liquid flow according to the water pressure information obtained by the pressure sensor, and automatically drive the piston rod to move, so that the proper opening degree is reached, and the corresponding opening degree can be automatically obtained no matter how the flow rate in the infusion pipeline is.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.