Digital combined gas mixing proportioning valve and proportioner thereof

Abstract

The utility model discloses a digital combined gas mixing proportioning valve, which is characterized by comprising two gas inlet shunting channels, a confluence mixing gas outlet channel and a plurality of two-way switching conduction branch throttling channels connected in parallel between the two gas inlet shunting channels and the confluence mixing gas outlet channel, each branch throttling channel is formed by connecting two paths of switching breakover valves and throttling holes in series, and has a discrete digital throttling circulation sectional area; the two-way switching breakover valve has two working positions, and each working position correspondingly conducts one way of gas. Two paths of gas are respectively input from respective gas inlet shunting channels, and according to a gas mixing proportion, two paths of gas circulation sectional areas are formed by controlling the working positions and digital combinations of the two paths of switching breakover valves, so that the output flow of the two paths of gas is controlled, and the mixed gas is converged, mixed and output; the device is applied to the field of gas mixing ratio, is suitable for dynamically changing the ratio in real time, can be used after being mixed after being prepared, and has the advantages of simplicity in control, high response speed, high repeated precision, convenience in replacement of damaged parts and the like.

Description

Technical Field

[0001] The present invention relates to controlling gas mixing ratio by using a digital combination gas mixing ratio valve, belonging to the technical field of gas mixing ratio devices; it can be used in various application fields of mixed gases, especially in the application fields where the mixed gas is used as an auxiliary gas for laser cutting and a shielding gas for laser welding. Background Art

[0002] Mixed gases are widely used in many fields: for metal welding, a mixture of two or more kinds of gases such as CO 2 , Ar, He and rare gases is used as a shielding gas; for food preservation, a mixture of two or more kinds of gases such as CO 2 , O 2 , N 2 , Ar is used as a preservation gas; for glass processing, a mixed gas of fuel gas, air and O 2 is used; for helium leak detection, a mixed gas of He and N 2 is used; for medical and diving purposes, "synthetic air" mixed with O 2 and N 2 is used, etc.

[0003] Existing gas mixing ratio technologies are usually based on the volume flow ratio principle of pressure balance, that is, on the premise that the input pressures of all gas paths are equal, the ratio of the volume flow rates of all gas paths is proportional to the ratio of the valve opening degrees (i.e., the flow cross-sectional areas) of the gas flow control valves of all gas paths. Existing gas mixing ratio devices are composed of a gas pressure balance unit, a gas flow control unit and a gas mixing unit, where: the gas pressure balance unit is responsible for balancing the input pressure differences of all gas paths so that the pressures of all gas paths are equal when they enter the gas flow control unit; the gas flow control unit is composed of flow control valves, and according to the mixing ratio, by adjusting the valve opening degrees (i.e., the flow cross-sectional areas) of the flow control valves, the flow rates of each gas path are adjusted; the gas mixing unit is responsible for uniformly mixing and outputting the mixed gas.

[0004] Gas mixing ratio devices are divided into two categories: static mixing and dynamic mixing according to the different gas mixing units. Static mixing pre-sets a fixed ratio and is provided with a storage tank as the gas mixing unit to store the mixed gas; only when the stored mixed gas is used up can the gas mixing ratio be changed, and it cannot be mixed and used immediately. The gas mixing unit of dynamic mixing is a gas confluence mixing area with a small space, which can be mixed and used immediately without a storage tank.

[0005] The gas flow control units used in existing gas mixing ratio technologies are as follows: The first type consists of a manual throttle valve and a flow meter. The manual throttle valve adjusts the gas flow, and the flow meter indicates the gas flow to assist in the adjustment. The advantages are simple operation and no need for electricity. The disadvantages are poor manual adjustment accuracy, poor repeatability accuracy, and inability to control the gas mixing ratio through a digital control program. The second type uses a solenoid valve to time the control of gas flow, and the storage tank stores the mixed gas, which belongs to static mixing. The third type is a motor-driven valve that adjusts the gas flow by driving the valve core displacement with a motor. The advantages are high mixing ratio accuracy and the ability to control the gas mixing ratio through a digital control program. However, due to the use of mechanical transmission mechanisms such as lead screws and nuts to convert rotational motion into linear displacement of the valve core, there is mechanical wear and it is not suitable for frequently changing the mixing ratio. The fourth type uses a gas mass flow controller (MFC), which consists of an electronic mass flow meter (MFM) and an electromagnetic proportional valve. The gas flow is controlled by continuously adjusting the opening of the electromagnetic proportional valve, and the electronic mass flow meter measures and feeds back for auxiliary adjustment. The advantages are high mixing ratio accuracy and the ability to control the gas mixing ratio through a digital control program. The disadvantages are high cost and uneconomical.

[0006] Laser cutting a closed contour goes through two processes: piercing and cutting. It is necessary to use auxiliary gas to blow away the molten material generated by the laser melting the sheet to form holes or cutting gaps. Usually, one of O 2 , N 2 , compressed air is used as the auxiliary gas; it is expected to use a mixed gas such as O 2 , N 2 etc. as the auxiliary gas, and different mixing ratios are used during the piercing and cutting processes; since laser cutting many closed contours continuously go through the processes of piercing and cutting, it is necessary to dynamically and frequently change the mixing ratio of the auxiliary gas through digital control in real time. In the existing technology, the motor-driven valve and the mass flow controller have the ability to digitally control the gas mixing ratio. However, the motor-driven valve is not suitable for frequently changing the gas mixing ratio, and the mass flow controller is costly; therefore, it is expected to develop a relatively economical, digitally controllable, and gas mixing ratio valve suitable for frequently changing the gas mixing ratio to achieve dynamic real-time digital control of the mixing ratio and immediate mixing and use. Summary of the Invention

[0007] The object of the present invention is to provide a relatively economical, digitally controllable, and gas mixing ratio valve that is easy to frequently change the gas mixing ratio, realizing dynamic real-time digital control of the gas mixing ratio and immediate mixing and use, and is used in various application fields of mixed gases, especially in the application fields where the mixed gas is used as the laser cutting auxiliary gas and the laser welding shielding gas; the technical measure taken is to use a digital combined gas mixing ratio valve composed of two-way switching and conducting branch throttle channels with multiple discrete digitalized throttle flow cross-sectional areas connected in parallel as the flow control mixing valve for two-way gas mixing ratio.

[0008] The digital combination gas mixing ratio valve proposed by the present invention is characterized in that it is composed of two gas inlet shunt channels, a confluence mixing outlet channel, and a plurality of two-way switching conduction branch throttle channels connected in parallel therebetween; each of the branch throttle channels is formed by connecting a two-way switching conduction valve (referred to as a switching valve) and a throttle orifice in series; for the switching valve, it has two air inlets respectively connected to the two gas inlet shunt channels, and an air outlet connected to the confluence mixing outlet channel through the throttle orifice; the switching valve has two working positions, and only one air inlet and air outlet are conducted in each working position, that is, when in one working position, the first gas inlet and air outlet of the two gases are conducted, and at the same time, the second gas inlet and air outlet are shut off, and when in the other working position, the second gas inlet and air outlet are conducted, and at the same time, the first gas inlet and air outlet are shut off; the throttle flow cross-sectional areas of the respective branch throttle channels are discretely digitalized and determined by the sizes of their throttle orifices, and all are in an integer multiple relationship with the smallest flow cross-sectional area, and the ratio of the throttle flow cross-sectional area of each branch throttle channel to the smallest flow cross-sectional area is used as its flow cross-sectional area number; by controlling the working positions of the respective switching valves, the throttle flow cross-sectional areas of the respective branch throttle channels are combined to form different flow cross-sectional areas for each gas path, and correspondingly, the flow cross-sectional area numbers of the respective branch throttle channels are combined to form different flow cross-sectional area numbers for each gas path; the flow cross-sectional area of each gas path is the sum of the flow cross-sectional areas of the branch throttle channels in a conducting state for that gas path, and correspondingly, the flow cross-sectional area number of each gas path is the sum of the flow cross-sectional area numbers of the branch throttle channels in a conducting state for that gas path. When all the branch throttle channels are conducting for one gas path, its flow cross-sectional area number takes the maximum flow cross-sectional area number, and at this time, the other gas path is in a shut-off state, and its flow cross-sectional area number is 0; on the premise of the balance of the inlet pressures of the two gases, the two gases are respectively input from their respective inlet shunt channels, and according to the gas mixing ratio, the working positions of the respective switching valves are controlled by digital switch quantities, and the flow cross-sectional area numbers of each gas path are combined to control the output flow rates of the two gases. Finally, the two gases enter the confluence mixing outlet channel and are mixed and then the mixed gas is output; the digital combination gas mixing ratio valve is applied to the field of gas mixing ratio and is suitable for dynamically and real-time changing the ratio, that is, mixing and using immediately upon mixing.

[0009] It should be noted that the digital combination gas mixing ratio valve is based on the principle of volume flow ratio matching under pressure balance, that is, on the premise that the pressures of the two gases are balanced (equal) before gas mixing, the ratio of the volume flow rates of the two gases is proportional to the ratio of the throttle flow cross-sectional areas of the two gases.

[0010] Further, for the digital combination gas mixing ratio valve described above, a specific configuration example in which each branch throttle channel has a discrete digital throttle flow cross-sectional area is that the flow cross-sectional areas s 0 、s 1 、s 2 、…、s i 、…、s (n-1) of the throttle holes in each branch throttle channel are successively 2 0 、2 0 、2 1 、…、2 2 、…、2 i 、…、2 (n-1) times the minimum flow cross-sectional area s i , where 2 i is the binary bit weight number, i takes values of 0, 1, 2, …, n - 1, n is the number of branch throttle channels, and it is called an n-channel binary digital combination gas mixing ratio valve; the flow cross-sectional area S 1 of the first gas in the two gases is equal to the sum of the throttle flow cross-sectional areas of the branch throttle channels that are in the conducting state for this gas, that is Correspondingly, the flow cross-sectional area S 2 of the second gas = (2 n - 1)s 0 - S 1 , where: s 0 is the minimum throttle flow cross-sectional area in the branch throttle channel; c i represents the on-position state value of the switching valve of the i-th branch throttle channel, taking 0 or 1. Taking 0 means that the i-th branch throttle channel is in the off state for the first gas and in the on state for the second gas. Taking 1 means that the i-th branch throttle channel is in the on state for the first gas and in the off state for the second gas; the digital value of the flow cross-sectional area of the first gas, that is, the ratio of the flow cross-sectional area S 1 of the first gas to the minimum throttle flow cross-sectional area s 0 When the c i values of each branch throttle channel are different, 0, 1, 2, 3, …, (2 n - 1) a total of 2 n flow cross-sectional area digital values are formed through digital combination, corresponding to 0, 1s 0 , 2s 0 , 3s 0 , …, (2 n - 1)s 0 of 2 n levels of discrete digital approximation of the continuous flow cross-sectional area. Correspondingly, the digital value of the flow cross-sectional area of the second gas is S 2 / s 0 = (2 n - 1) - S1 / s 0 , the corresponding digital combinations form (2 n -1), …, 3, 2, 1, 0, a total of 2 n circulation cross-sectional area numbers, corresponding to form (2 n -1)s 0 , …, 3s 0 , 2s 0 , 1s 0 , 0, a total of 2 n levels of discrete digitization to approximate the continuous circulation cross-sectional area.

[0011] Furthermore, for the digital combination gas mixing ratio valve described above, it is characterized in that a structural example of the switching valve is composed of a valve body, a cylindrical piston valve core and its driving components. There is a valve core sliding channel in the valve body, and there are two air inlets and one air outlet on the valve body. When the valve core slides in the valve body, it has two working positions. When in one working position, the first air inlet and the air outlet are conducted, and at the same time the second air inlet and the air outlet are shut off. When in the other working position, the second air inlet and the air outlet are conducted, and at the same time the first air inlet and the air outlet are shut off. The valve core driving components include direct-acting electromagnetic drive type, step-by-step direct-acting (internal pilot) electromagnetic drive type, and micro solenoid valve controlled pilot gas drive type categories. The installation categories of the switching valve involved include pipe connection type and cartridge valve type.

[0012] Furthermore, the structural feature of the digital combination gas mixing ratio valve described above is that it can adopt a simple structural example form of connecting the switching valve with an air pipe and a three-way pipe joint, and preferably adopt a compact integrated valve body structural example form of clamping type, pipe connection type, cartridge valve type or cartridge valve core type:

[0013] The clamping structure: It consists of a two-way gas intake shunt channel valve body, a confluence mixing outlet channel valve body, multiple pipe-connected switching valves, and fixing screws; on the intake shunt channel valve body, there are two-way gas intake shunt channels and their gas input interfaces. Each gas intake shunt channel is provided with multiple shunt holes arranged at intervals, which are respectively docked with the gas intake ports of each branch throttle channel switching valve of this path; the confluence mixing outlet channel valve body is provided with a confluence mixing outlet channel and its mixed gas output interface. The confluence mixing outlet channel is provided with multiple throttle holes arranged at intervals, which are respectively docked with the outlet ports of each branch throttle channel switching valve; each switching valve of the branch throttle channel is clamped between the intake shunt channel valve body and the confluence mixing outlet channel valve body and is fixed by multiple screws; one switching valve simultaneously controls the switching and conduction of the gas flow in two paths to branch throttle channels. A certain shunt hole in the first gas intake shunt channel, the first gas intake port on the switching valve docked with it, the outlet port of this switching valve, and the throttle hole on the confluence mixing outlet channel docked with the outlet port of this switching valve form a branch throttle channel for the first gas flow. Similarly, a certain shunt hole in the second gas intake shunt channel, the second gas intake port on the switching valve docked with it, the outlet port of this switching valve, and the throttle hole on the confluence mixing outlet channel docked with the outlet port of this switching valve form a branch throttle channel for the second gas flow; multiple two-way switching and conduction branch throttle channels are connected through the two-way gas intake shunt channels and the confluence mixing outlet channel to form multiple two-way gas switching and conduction branch throttle channels connected in parallel of the digital combination gas mixing ratio valve;

[0014] The described pipe connection type structure: It is composed of a two-way gas intake shunt channel valve body, a confluence mixing outlet channel valve body, multiple pipe connection type switching valves, and gas pipes; on the intake shunt channel valve body, there are two-way gas intake shunt channels and their gas input interfaces. Each gas intake shunt channel is provided with multiple shunt hole pipe interfaces arranged at intervals, which are respectively butted with the gas intake ports of each branch throttle channel switching valve and connected through gas pipes; the confluence mixing outlet channel valve body is provided with a confluence mixing outlet channel and its mixed gas output interface. The confluence mixing outlet channel is provided with multiple throttle hole pipe interfaces arranged at intervals, which are respectively butted with the outlet ports of each branch throttle channel switching valve and connected through gas pipes; each switching valve of the branch throttle channel is located between the intake shunt channel valve body and the confluence mixing outlet channel valve body; one switching valve simultaneously controls the switching and conduction of the two-way gas flow to branch the throttle channel. A certain shunt hole pipe interface of the first-way gas intake shunt channel, the first-way gas intake port on the switching valve butted with it, the outlet port of this switching valve, and the throttle hole pipe interface on the confluence mixing outlet channel butted with the outlet port of this switching valve form a branch throttle channel for the first-way gas flow. Similarly, a certain shunt hole pipe interface of the second-way gas intake shunt channel, the second-way gas intake port on the switching valve butted with it, the outlet port of this switching valve, and the throttle hole pipe interface on the confluence mixing outlet channel butted with the outlet port of this switching valve form a branch throttle channel for the second-way gas flow; multiple two-way switching and conduction branch throttle channels are connected through the two-way gas intake shunt channels and the confluence mixing outlet channel, constituting multiple two-way gas switching and conduction branch throttle channels connected in parallel of the digital combination gas mixing ratio valve;

[0015] The cartridge valve type structure described above: It consists of a valve body and multiple cartridge type switching valves; two gas inlet shunt channels and their gas input interfaces, a confluence mixing outlet channel and its gas output interface, and insertion and installation threaded holes for multiple cartridge type switching valves arranged at intervals are provided inside the valve body; there are two shunt holes in each insertion and installation threaded hole, which are respectively communicated with the two gas inlet shunt channels, and there is a throttle hole communicated with the confluence mixing outlet channel; the cartridge type switching valve is inserted into the insertion and installation threaded hole and fixed on the valve body; one switching valve simultaneously controls the switching conduction of the two gas flow branch throttle channels. The first gas shunt hole in each insertion and installation threaded hole, the first gas inlet of the cartridge type switching valve docked with it, the outlet of this cartridge type switching valve, and the throttle hole in this installation threaded hole constitute a branch throttle channel for the first gas flow. Similarly, the second gas shunt hole in this installation threaded hole, the second gas inlet of the cartridge type switching valve docked with it, the outlet of this cartridge type switching valve, and the throttle hole in this installation threaded hole constitute a branch throttle channel for the second gas flow; multiple two-way switching conduction branch throttle channels are communicated through the two gas inlet shunt channels and the confluence mixing outlet channel, constituting multiple two-way gas switching conduction branch throttle channels connected in parallel of the digital combination gas mixing and proportioning valve.

[0016] The cartridge valve core type structure described above: It consists of a valve body and multiple two-way switching conduction cartridge valve cores; two gas inlet shunt channels and their gas input interfaces, a confluence mixing outlet channel and its gas output interface, and multiple cartridge valve core sliding channels arranged at intervals are provided inside the valve body; there are two shunt holes in each cartridge valve core sliding channel, which are respectively communicated with the two gas inlet shunt channels, and there is a throttle hole communicated with the confluence mixing outlet channel; each cartridge valve core is inserted into a sliding channel and has two working positions when sliding in the sliding channel. When in one working position, the first gas shunt hole and the throttle hole are conducted, and at the same time, the second gas shunt hole and the throttle hole are shut off. When sliding to the other working position, the second gas shunt hole and the throttle hole are conducted, and at the same time, the first gas shunt hole and the throttle hole are shut off, forming a two-way switching conductor valve; one two-way switching conduction cartridge valve core simultaneously controls the switching conduction of the two gas flow branch throttle channels. The first gas shunt hole in each sliding channel, the cylindrical annular groove of the cartridge valve core, and the throttle hole in this sliding channel constitute a branch throttle channel for the first gas flow. Similarly, the second gas shunt hole in this sliding channel, the cylindrical annular groove of the cartridge valve core, and the throttle hole in this sliding channel constitute a branch throttle channel for the second gas flow; multiple two-way switching conduction branch throttle channels are communicated through the two gas inlet shunt channels and the confluence mixing outlet channel, constituting multiple two-way gas switching conduction branch throttle channels connected in parallel of the digital combination gas mixing and proportioning valve.

[0017] The throttle orifices of the respective two-way gas switching and conducting branch throttling channels can be arranged at the gas outlet of the switching valve.

[0018] The digital combination gas mixing and proportioning device proposed by the present invention is an application of the digital combination gas mixing and proportioning valve proposed by the present invention, including a digital combination two-way gas mixing and proportioning device and a digital combination multi-way gas mixing and proportioning device. It is characterized in that the digital combination two-way gas mixing and proportioning device mainly consists of a two-way gas pressure balancing unit and a digital combination gas mixing and proportioning valve. Two-way gases are input from the pressure balancing unit, and after differential pressure balancing, the pressures of the two-way gases are equal before mixing and proportioning. Then, the two-way gases are input into the digital combination gas mixing and proportioning valve. According to the mixing and proportioning ratio of the two-way gases, the cross-sectional areas of the two-way gases are digitally controlled by switch quantities, so as to control the output flow rates of the two-way gases. Finally, the two-way gases are mixed in the digital combination gas mixing and proportioning valve and then the mixed gas is output; for the digital combination multi-way gas mixing and proportioning device, one of the digital combination two-way gas mixing and proportioning devices first mixes two of the gases, and then the output mixed gas is used as one gas, and then another digital combination two-way gas mixing and proportioning device mixes with another gas, and so on, to form a digital combination multi-way gas mixing and proportioning device, which is applied to multi-way gas mixing and proportioning.

[0019] It should be specially noted that a two-way gas pressure balancing unit is installed in front of the digital combination gas mixing and proportioning valve. When the input pressure fluctuates and the output flow rate changes, the two-way gas pressure balancing unit can balance the input differential pressure of each gas in real time, so that the pressures of the two-way gases are equal before mixing and proportioning, and the gas mixing and proportioning remains unchanged. The two-way gas pressure balancing unit consists of a gas pressure balancing valve, and a gas pressure (differential pressure) balancing valve used in the existing publicly disclosed gas mixing and proportioning technology is adopted.

[0020] The digital combination gas mixing and proportioning valve and its application proposed by the present invention are used for the control of gas mixing and proportioning, and have the following beneficial effects:

[0021] 1. By adopting switch quantity digital control, it can dynamically and real-time frequently change the gas mixing and proportioning and mix and use the gas immediately as it is prepared.

[0022] 2. It has the advantages of simple control, fast response speed, high repeat accuracy, and is convenient for replacing damaged parts during maintenance.

[0023] 3. The cross-sectional area of the flow is predictable, and it is unnecessary to use a flow meter to measure the gas flow rate for auxiliary mixing and proportioning.

[0024] 4. By adopting electromagnetic drive control, it is a relatively economical gas mixing and proportioning valve.

[0025] 5. It can be widely used in various application fields of mixed gases, such as using the mixed gas as an auxiliary gas for laser cutting and a shielding gas for laser welding, etc. Description of the Drawings

[0026] Figure 1-1 Pneumatic system diagram of a digital combined gas mixing and proportioning valve controlled by a direct-acting electromagnetic drive type switching valve

[0027] Figure 1-2 Pneumatic system diagram of a digital combined gas mixing and proportioning valve controlled by a step-by-step direct-acting (internally piloted) electromagnetic drive type switching valve

[0028] Figure 1-3 Pneumatic system diagram of a digital combined gas mixing and proportioning valve controlled by a micro solenoid valve controlling a pilot gas driven type switching valve

[0029] Figure 2-1 External shape schematic diagram of a clamped structure example of a digital combined gas mixing and proportioning valve

[0030] Figure 2-1-1 Schematic diagram of the clamped component structure of a digital combined gas mixing and proportioning valve

[0031] Figure 2-1-2 Schematic diagram of the cross-sectional structure of a clamped dual-channel switching and conducting branch throttling channel of a digital combined gas mixing and proportioning valve

[0032] Figure 2-2 External shape schematic diagram of a screwed structure example of a digital combined gas mixing and proportioning valve

[0033] Figure 2-3 External shape schematic diagram of an inserted valve type structure example of a digital combined gas mixing and proportioning valve

[0034] Figure 2-3-1 Schematic diagram of the inserted valve type component structure of a digital combined gas mixing and proportioning valve

[0035] Figure 2-3-2 Schematic diagram of the cross-sectional structure of an inserted valve type dual-channel switching and conducting branch throttling channel of a digital combined gas mixing and proportioning valve

[0036] Figure 2-4 External shape schematic diagram of an inserted valve core type structure example of a digital combined gas mixing and proportioning valve

[0037] Figure 2-4-1 Schematic diagram of the inserted valve core type component structure of a digital combined gas mixing and proportioning valve

[0038] Figure 2-4-2 Schematic diagram of the cross-sectional structure of an inserted valve core type dual-channel switching and conducting branch throttling channel of a digital combined gas mixing and proportioning valve

[0039] Figure 3 Block diagram of a two-channel gas mixing and proportioning device composed of digital combined gas mixing and proportioning valves

[0040] Figure 3-1 With digital control O2 and N 2 Schematic Diagram of Laser Cutting Assist Gas Pressure Control System with Two-way Gas Mixing and Ratio Function

[0041] Figure 3-2 With Digital Control of CO 2 Schematic Diagram of Laser Welding Protection Gas Flow Control System with Two-way Gas Mixing and Ratio Function of CO and Ar

[0042] Explanation of Reference Signs: g 1 The first gas and its input interface, g 2 The second gas and its gas output interface, g m The mixed gas and its output interface, g p The pilot gas and its input interface, v 0 -v (n-1) Respectively represent the individual switching valves of the digital combined gas mixing and ratio valve, s 0 -s (n-1) Respectively represent the individual switching conduction branch throttle channels, throttle orifices and their throttle flow areas of the digital combined gas mixing and ratio valve, v p0 -v p(n-1) Respectively represent the miniature two-way three-way solenoid valves for pilot gas control of the individual pilot gas-driven switching valves, 1 The first gas intake shunt channel, 2 The second gas intake shunt channel, 3 The confluence mixing outlet channel, 4 The valve body, 4-1 The intake shunt channel valve body, 4-2 The confluence mixing outlet channel valve body, 5 The switching valve or the inserted spool of the switching valve and its electromagnetic drive part, 5-1 The switching valve body, 5-2 The cylindrical piston spool of the switching valve, 5-3 The return spring of the switching valve, 5-4 The first gas intake port of the switching valve, 5-5 The second gas intake port of the switching valve, 5-6 The outlet port of the switching valve, 6 The plug, 7-1 The shunt hole of the first gas intake shunt channel, 7-2 The shunt hole of the second gas intake shunt channel, 8 The throttle orifice of the branch throttle channel, 9 The connection and installation hole, 10 The clamp block, 11 The connection screw for installation, 12 The trachea interface, 13 The trachea, 14 The inserted valve insertion installation thread hole, 14-1 The sliding channel of the inserted spool, 15-1 The processing hole for the shunt hole of the first gas intake shunt channel, 15-2 The processing hole for the shunt hole of the second gas intake shunt channel, 16 The processing hole for the throttle orifice of the branch throttle channel, 17 The gas source, 18 The pressure reducing valve, 19 The gas mixing and ratio device, 20 The check valve, 21 The gas output nozzle, PBU The gas pressure balance unit, V The digital combined gas mixing and ratio valve, V N Nitrogen gas path selection switch valve, V A Compressed air path selection switch valve, V m Mixed gas path selection switch valve, V P Gas pressure regulating valve, V FGas flow regulating valve, P pressure gauge, F flowmeter, the "→" arrow indicates the gas flow direction or the spool sliding direction, and "…" is an ellipsis indicating that multiple parallel switching branch throttle channels and their control switching valves are omitted. Detailed implementation mode

[0043] The present invention will be further described below in conjunction with the pneumatic system diagram, structural feature diagram, block diagram and application examples, but the present invention is not limited to the following configuration examples, structural examples and application examples of discrete digital throttle flow cross-sectional areas.

[0044] 1. Pneumatic system diagram of the digital combination gas mixing ratio valve and its composition description

[0045] Figure 1-1 , Figure 1-2 and Figure 1-3 are the pneumatic system diagrams of the n-channel digital combination gas mixing ratio valve, which consists of the first gas and its input interface g 1 and the intake air shunt channel 1, the second gas and its input interface g 2 and the intake air shunt channel 2, the control switching valves v 0 , v 1 , v 2 , …, v (n-1) , the throttle orifices s 0 , s 1 , s 2 , …, s (n-1) , the confluence mixing outlet channel 3 and the mixed gas output port g m are composed. Among them: v i and s i are connected in series to form the i-th switching branch throttle channel, i = 0, 1, 2, …, (n - 1), and n is the number of branch throttle channels and their control switching valves; at the same time, s i also represents the throttle (orifice) flow cross-sectional area of the i-th branch throttle channel; each switching branch throttle channel is connected in parallel through the two-way gas intake shunt channels 1, 2 and the confluence mixing outlet channel 3 to form multiple parallel branch throttle channels for two-way gas switching conduction of the digital combination gas mixing ratio valve. Among them: Figure 1-1 in v 0 , v 1 , v 2 , …, v (n-1) are direct-acting electromagnetic drive type switching valves, Figure 1-2 in v 0 , v 1 , v 2 , …, v (n-1)It is a step-by-step direct-acting (internal pilot) electromagnetically driven switching valve. For each branch throttling channel, when the electromagnetic coil of the switching valve is not energized, the switching valve is in a working position under the action of the reset spring, the first gas is connected, and the second gas is shut off. When the electromagnetic coil of the switching valve is energized, the switching valve switches to another working position, the second gas is connected, and the first gas is shut off. Figure 1-3 Medium 0 、v 1 、v 2 ,…,v (n-1) It is a pilot gas driven switching valve, which consists of v p0 、v p1 、v p2 ,…,v p(n-1) Miniature two-position three-way solenoid valve controls pilot gas g p For each branch throttling channel, when the solenoid coil of the micro two-position three-way solenoid valve is not energized, the switching valve is in a working position under the action of the reset spring, the first gas is turned on, and the second gas is turned off. When the solenoid coil of the micro two-position three-way solenoid valve is energized, the pilot gas is turned on to drive the switching valve to switch to another working position, the second gas is turned on, and the first gas is turned off.

[0046] An example of a configuration in which the throttle holes of each branch throttle channel have a digital throttle flow cross-sectional area is a binary digital combination configuration, in which the throttle flow cross-sectional area of ​​each branch throttle channel throttle hole is s 0 、s 1 、s 2 ,…,s i ,…,s (n-1) , followed by the minimum flow cross-sectional area s 0 of 2 0 , 2 1 , 2 2 , …, 2 i , …, 2 (n-1) Multiple, 2 i is the binary bit weight, i is 0, 1, 2, ..., n-1, n is the number of branch throttling channels, called n-channel binary digital combination gas mixing ratio valve; the flow cross-sectional area S of the first gas in the two gas paths 1 It is equal to the sum of the throttling flow cross-sectional areas of the branch throttling channels that are in the conducting state for the gas, that is, Correspondingly, the second gas flow cross-sectional area S 2 =(2 n -1)s 0 -S 1 , where: s 0 is the minimum throttling flow cross-sectional area in the branch throttling channel; c iIt represents the on - position status value of the i - th branch throttle channel switching valve, taking 0 or 1. Taking 0 means that the i - th branch throttle channel is in the off state for the first gas path and in the on state for the second gas path; taking 1 means that the i - th branch throttle channel is in the on state for the first gas path and in the off state for the second gas path; the first - path gas flow cross - sectional area number is the flow cross - sectional area S of the first gas path. 1 and the minimum throttle flow cross - sectional area s 0 ratio Each branch throttle channel c i has different values, and through digital combinations, 0, 1, 2, 3, …, (2 n - 1) a total of 2 n flow cross - sectional area numbers are formed, corresponding to 0, 1s 0 , 2s 0 , 3s 0 , …, (2 n - 1)s 0 of the 2 n - level discrete digital approximation of the continuous flow cross - sectional area. Correspondingly, the second - path gas flow cross - sectional area number is S 2 / s 0 =(2 n - 1)-S 1 / s 0 , corresponding digital combinations form (2 n - 1), …, 3, 2, 1, 0 a total of 2 n flow cross - sectional area numbers, corresponding to (2 n - 1)s 0 , …, 3s 0 , 2s 0 , 1s 0 , 0 of the 2 n - level discrete digital approximation of the continuous flow cross - sectional area.

[0047] 2. Structural feature examples of the digital combination gas mixing ratio valve

[0048] Figure 2-1 , Figure 2-2 , Figure 2-3 and Figure 2-4 Series of figures are respectively the schematic diagrams of the structural examples of the clamping - type, pipe - connection type, cartridge - valve type, and cartridge - valve core type of the compact integrated valve body of the digital combination gas mixing ratio valve. Without loss of generality, the direct - acting electromagnetic - drive - type switching valve is taken as an example in the figure to illustrate the structural features of the digital combination gas mixing ratio valve.

[0049] Figure 2-1The digital combined gas mixing ratio valve clamp-type structure example is a schematic diagram of the appearance, which consists of a two-way gas inlet diversion channel valve body 4-1, a plurality of pipe-connected switching valves 5, a converging mixed gas outlet channel valve body 4-2, a clamping block 10 and a connecting fixing screw 11; the inlet diversion channel valve body 4-1 has a first gas input interface g 1 And the second gas input interface g 2 There is a mixed gas output interface g on the converging mixed gas outlet channel valve body 4-2 m A plurality of pipe-connected switching valves 5 and clamping blocks 10 are sandwiched between the two-way gas inlet diversion channel valve body 4-1 and the converging mixing outlet channel valve body 4-2, and are fixedly connected together by screws 11.

[0050] Figure 2-1-1 (a) is a schematic diagram of the structure of the valve body of the clamped two-way gas inlet diversion channel: To facilitate observation of the diversion holes, the figure is a schematic diagram of the valve body structure of the inlet diversion channel valve body 4-1 with the direction of the inlet diversion channel as the axis and rotated 180 degrees around the axis. The inlet diversion channel valve body 4-1 has an inlet diversion channel 1 for the first gas and a plurality of diversion holes 7-1 arranged at intervals, and an inlet diversion channel 2 for the second gas and a plurality of diversion holes 7-2 arranged at intervals; there is a clamped connection installation hole 9 on the valve body.

[0051] Figure 2-1-1 (b) is a clamped converging mixed gas outlet channel valve body 4-2, which has a converging mixed gas outlet channel 3 and its branch throttling channel throttling holes 8 arranged at intervals, and there are two gas mixed gas output interfaces g on the converging mixed gas outlet channel 3 m ; There is a clamping connection mounting hole 9 on the valve body.

[0052] Figure 2-1-1 (c) is a schematic diagram of a clamping block: the clamping block 10 has a connecting mounting hole 9 through which a screw can pass.

[0053] Figure 2-1-1 (d) and Figure 2-1-1 (e) is a schematic diagram of the clamp-on switching valve: Figure 2-1-1 (d) Rotated 180° is Figure 2-1-1 (e) There are a first gas inlet 5-4, a second gas inlet 5-5 and an outlet 5-6 on the valve body of the switching valve 5. The first gas inlet 5-4 and the first gas inlet diversion channel diversion hole 7-1 on the gas inlet diversion channel valve body are connected to each other, the second gas inlet 5-5 and the second gas inlet diversion channel diversion hole 7-2 on the gas inlet diversion channel valve body are connected to each other, and the outlet 5-6 and the throttle hole 8 of the converging mixing outlet channel valve body 4-2 are connected to each other.

[0054] Figure 2-1-2(a) and (b) are schematic cross-sectional views of a digital combination gas mixing ratio valve with a clamped type, showing any one of the double-path switching and conducting branch throttling channels perpendicular to the direction of the confluence and mixing outlet channel: Each switching valve consists of a cuboid-shaped valve body 5-1, a cylindrical piston valve core 5-2 and its electromagnetic drive part (not marked in the figure), and a return spring 5-3. For a certain branch throttling channel, as shown in 2-1-2(a), when the electromagnetic drive coil of the switching valve is not energized, the valve core 5-2 is in the working position under the action of the return spring. At this time, the first gas inlet 5-4 and the outlet 5-6 of the switching valve are conducted through the annular groove of the cylindrical piston valve core, and the second gas inlet 5-5 is shut off; at this time, the flow path of the first gas is gas input interface g 1 → intake air shunt channel 1 → shunt hole 7-1 → first gas inlet 5-4 of switching valve 5 → annular groove of the cylindrical piston valve core of switching valve 5 → outlet 5-6 of switching valve 5 → throttling hole 8 on the confluence and mixing outlet channel → confluence and mixing outlet channel 3 → mixed gas output interface g m , and the second gas is shut off. As shown in 2-1-2(b), when the electromagnetic drive coil of the switching valve is energized, the valve core 5-2 is in the working position in the sliding channel of the valve body 5-1. At this time, the second gas inlet 5-5 and the outlet 5-6 of the switching valve are conducted through the annular groove of the cylindrical piston valve core, and the first gas inlet 5-4 is shut off; at this time, the flow path of the second gas is gas input interface g 2 → intake air shunt channel 2 → shunt hole 7-2 → second gas inlet 5-5 of switching valve 5 → annular groove of the cylindrical piston valve core of switching valve 5 → outlet 5-6 of switching valve 5 → throttling hole 8 on the confluence and mixing outlet channel → confluence and mixing outlet channel 3 → mixed gas output interface g m , and the first gas is shut off. The two working positions of the switching valve 5 correspond to the switching on and off states of the two-way gas branch throttling channels.

[0055] Figure 2-2 is a schematic external view of a structure example of a digital combination gas mixing ratio valve with a pipe connection type, which consists of a two-way gas intake air shunt channel valve body 4-1, multiple pipe connection type switching valves 5, a confluence and mixing outlet channel valve body 4-2, a gas pipe joint 12 and a gas pipe 13; on the intake air shunt channel valve body 4-1, there is a first gas input interface g 1 and a second gas input interface g 2 , and on the confluence and mixing outlet channel valve body 4-2, there is a mixed gas output interface g mThe air intake diversion channel valve body 4-1, multiple pipe-connected switching valves 5, and the converging mixed outlet channel valve body 4-2 are all the same as the clamp-type structure, the only difference is that the pipe-connected air intake diversion channel valve body 4-1, multiple pipe-connected switching valves 5, and the converging mixed outlet channel valve body 4-2 are connected by a pipe joint 12 and an air pipe 13, forming multiple two-way gas switching conduction branch throttling channels connected in parallel of the digital combined gas mixing and proportioning valve.

[0056] Figure 2-3 This is a schematic diagram of the appearance of a digital combined gas mixing ratio valve cartridge valve structure example: it consists of a cartridge valve body 4, a plurality of cartridge switching valves 5 arranged at intervals, and a processing hole plug 6; the cartridge valve body 4 has a first gas input interface g 1 , Second gas input interface g 2 And mixed gas output interface g m ; The plug-in switching valve 5 is inserted and fixed on the valve body 4.

[0057] Figure 2-3-1 (a) and (b) are schematic diagrams of the structure of the cartridge valve body: the cartridge valve body 4 has a first gas inlet diversion channel 1 and a gas input interface g inside. 1 , there is a second gas inlet branch channel 2 and a gas input interface g 2 The plug-in valve body 4 has insert-mounting threaded holes 14 for inserting and mounting the branch throttling channel plug-in switching valves arranged at intervals. Each insert-mounting threaded hole 14 has a bypass hole 7-1 connected to the first gas inlet bypass channel 1, a bypass hole 7-2 connected to the second gas inlet bypass channel 2, and a throttling hole 8 connected to the converging mixing outlet channel 3, which are formed by corresponding process holes 15-1, 15-2, and 16 arranged at intervals on the side of the plug-in valve body; the process holes 15-1, 15-2 and 16 are blocked with plugs 6.

[0058] Figure 2-3-1 (c) is a schematic diagram of the appearance of the cartridge switching valve: one side of the valve body annular cylindrical surface of the cartridge switching valve 5 is the first gas inlet 5-4 and the second gas inlet 5-5, and the other side is the gas outlet 5-6; the first gas inlet 5-4 is connected to the diverter hole 7-1 of the first gas inlet diverter channel on the cartridge valve body 4, the second gas inlet 5-5 is connected to the diverter hole 7-2 of the second gas inlet diverter channel on the cartridge valve body 4, and the gas outlet 5-6 is connected to the throttle hole 8 on the cartridge valve body 4.

[0059] Figure 2-3-2(a) and (b) are schematic cross-sectional views of the plug-in valve type of the digital combination gas mixing ratio valve, where any of the two-way switching and conducting branch throttle channels is perpendicular to the direction of the confluence and mixing outlet channel: Each switching valve consists of a cylindrical valve body 5-1, a cylindrical piston valve core 5-2 and its electromagnetic drive part (not marked in the figure), and a return spring 5-3. For a certain branch throttle channel, Figure 2-3-2 As shown in (a), when the electromagnetic drive coil of the switching valve is not energized and it is in the spring return working position, the flow path of the first gas is the gas input interface g 1 → intake air shunt channel 1 → shunt hole 7-1 → the first intake port 5-4 of the switching valve 5 → the annular groove of the cylindrical piston valve core of the switching valve 5 → the outlet port 5-6 of the switching valve 5 → throttle hole 8 → confluence and mixing outlet channel 3 → mixed gas output interface g m , and the second gas is shut off. Figure 2-3-2 As shown in (b), when the electromagnetic drive coil of the switching valve is energized and it is in another working position, the flow path of the second gas is the gas input interface g 2 → intake air shunt channel 2 → shunt hole 7-2 → the second intake port 5-5 of the switching valve 5 → the annular groove of the cylindrical piston valve core of the switching valve 5 → the outlet port 5-6 of the switching valve 5 → throttle hole 8 → confluence and mixing outlet channel 3 → mixed gas output interface g m , and at the same time the first gas is shut off. The two working positions of the switching valve 5 correspond to the switching on and off states of the two gas branch throttle channels.

[0060] Figure 2-4 is a schematic external view of an example of the plug-in valve core type structure of the digital combination gas mixing ratio valve: It consists of a plug-in valve body 4, a plurality of switching valve plug-in valve cores arranged at intervals and their electromagnetic drive parts 5, and a processing technology hole plug 6; on the plug-in valve body 4, there is a first gas input interface g 1 , a second gas input interface g 2 , and a mixed gas output interface g m .

[0061] Figure 2-4-1 (a) is a schematic view of the plug-in valve body structure: Inside the plug-in valve body 4, there is an intake air shunt channel 1 for the first gas and its gas input interface g 1 , and an intake air shunt channel 2 for the second gas and its gas input interface g 2; On the cartridge valve body 4, there are insertion and sliding channels 14-1 for switching the respective branch throttle channels arranged at intervals; in each insertion and sliding channel 14-1 on the cartridge valve body 4, there is a shunt hole 7-1 communicating with the first gas inlet shunt channel 1, a shunt hole 7-2 communicating with the second gas inlet shunt channel 2, and a throttle hole 8 communicating with the confluence and mixing outlet channel 3, which are respectively formed through the corresponding process holes 15-1, 15-2, and 16 arranged at intervals on the side of the cartridge valve body; the process holes 15-1, 15-2, and 16 are blocked by plugs 6.

[0062] Figure 2-4-1 (b) is a schematic diagram of the external shape of the cartridge valve core: The cartridge valve core 5-2 is a cylindrical piston structure, and its annular groove is a gas flow channel.

[0063] Figure 2-4-2 (a) and (b) are schematic cross-sectional structures of any dual-channel switching and conducting branch throttle channel of the digital combination gas mixing ratio valve cartridge valve core perpendicular to the confluence and mixing outlet channel direction: A switching valve consists of a cartridge valve core 5-2 and its electromagnetic drive part (not marked in the figure), an insertion and sliding channel 14-1 on the cartridge valve body, and a return spring 5-3. For a certain branch throttle channel, Figure 2-4-2 (a) shows that when the electromagnetic drive coil of the cartridge valve core is not energized, the cartridge valve core is in the spring return working position. At this time, the flow path of the first gas is the gas input interface g 1 → inlet shunt channel 1 → shunt hole 7-1 → annular groove of the switching valve core 5-2 → throttle hole 8 → confluence and mixing outlet channel 3 → mixed gas output interface g m , and the second gas is shut off. Figure 2-4-2 (b) shows that when the electromagnetic drive coil of the cartridge valve core is energized, the cartridge valve core is in another working position. At this time, the flow path of the second gas is the gas input interface g 2 → inlet shunt channel 2 → shunt hole 7-2 → annular groove of the switching valve core 5-2 → throttle hole 8 → confluence and mixing outlet channel 3 → mixed gas output interface g m , and the first gas is shut off. The two working positions of the cartridge valve core 5-2 in the sliding channel 14-1 correspond to the switching on and off states of the two-way gas branch throttle channels.

[0064] 3. Two-way gas mixing ratio mixer composed of digital combination gas mixing ratio valves and its application examples

[0065] Figure 3It is a block diagram of a two-way gas mixing ratio mixer composed of a digital combination gas mixing ratio valve: It is formed by connecting two-way gas pressure balance unit PBU and digital combination gas mixing ratio valve V through gas pipeline 13. The two-way gas pressure balance unit PBU is composed of gas pressure balance valves, using the gas pressure (differential pressure) balance valves used in the existing publicly disclosed gas mixing ratio technology, which will not be elaborated here. The two-way gases g 1 and g 2 are input from the pressure balance unit PBU, and after differential pressure balance, the pressures of the two-way gases are equal; then the two-way gases g 1 and g 2 flow into the digital combination gas mixing ratio valve V. According to the two-way gas mixing ratio, the digital cross-sectional areas of the two-way gas flow through the digital combination gas mixing ratio valve V are controlled by digital control of switch quantity, so as to control the output flow of the two-way gases; finally, the two-way gases g 1 and g 2 are mixed in the confluence and mixing outlet channel of the digital combination gas mixing ratio valve V and then the mixed gas g m is output.

[0066] Figure 3-1 is a laser cutting auxiliary gas pressure control system diagram with digital control of O 2 and N 2 two-way gas mixing ratio functions: It is composed of gas source 17, pressure reducing valve 18, compressed air (Air) selection switch valve V A , high-pressure nitrogen (N 2 ) selection switch valve V N , oxygen (O 2 ) and nitrogen (N 2 ) two-way gas mixer 19 and its mixed gas selection switch valve V m , one-way valve 20, gas output pressure control valve V P , pressure gauge P, and gas output nozzle 21 are connected through gas pipeline 13. Among them: The gas output pressure control valve V P is used to control the gas output pressure; the pressure gauge P is installed on the cutting head of the laser cutting equipment and is used to measure and indicate the pressure value of the gas output near the nozzle; the nozzle 21 is a component of the laser cutting head; the two-way gas mixer 19 is composed of a pressure balance unit PBU and a digital combination gas mixing ratio valve V according to Figure 3 shown.

[0067] Laser cutting auxiliary gas type selection: (1) Select compressed air (Air): Control V A to be in the conducting state, and V N and V m are both in the off state; (2) Select 30bar-class high-pressure N 2 : Control V Nis in the conducting state, V A and V m are both in the off state; (3) Select the 10 bar level O 2 : Control V N and V A are both in the off state, V m is in the conducting state, set the digital value of the flow cross-sectional area of V to O 2 to the maximum value, that is, V to O 2 is in the fully conducting state, and N 2 is in the fully off state; (4) Select the 10 bar level N 2 : Control V N and V A are both in the off state, V m is in the conducting state, set the digital value of the flow cross-sectional area of V to N 2 to the maximum value, that is, V to O 2 is in the fully off state, and N 2 is in the fully conducting state; (5) Select the O 2 and N 2 mixed gas: Control V A and V N are both in the off state, V m is in the conducting state, and set the digital value of the flow cross-sectional area of V according to the mixing ratio of O 2 and N 2 .

[0068] V takes Figure 1-2 a 7-channel binary digital combination gas mixing ratio valve, the throttle cross-sectional areas s 0 , s 1 , s 2 , s 3 , s 4 , s 5 , s 6 are 1s 0 , 2s 0 , 4s 0 , 8s 0 , 16s 0 , 32s 0 , 64s 0 in sequence, and the corresponding flow cross-sectional area digital values are 1, 2, 4, 8, 16, 32, and 64 respectively. The flow cross-sectional area digital value of the first gas O 2 is The switching valves of each branch throttle channel for O 2 are in the conducting (c i = 1) or off (c i = 0) states differently, and are combined to form O 2The digital range of the flow cross-sectional area is 0 - 127; correspondingly, for the second gas N 2 the digital value of the flow cross-sectional area is S 2 / s 0 = 127 - S 1 / s 0 。Taking the maximum flow cross-sectional area of V as 32 mm 2 (Note: equivalent to a valve with a nominal diameter of 1 / 4 inch), calculate the cross-sectional area s i of the throttle orifice of each branch throttle passage and its aperture d i (i = 0 - 6): s 0 = 32 / 127 = 0.252 mm 2 , d 0 = 0.567 mm; s 1 = 2s 0 = 0.504 mm 2 , d 1 = 0.8 mm; s 2 = 4s 0 = 1.008 mm 2 , d 2 = 1.134 mm; s 3 = 8s 0 = 2.016 mm 2 , d 3 = 1.602 mm; s 4 = 16s 0 = 4.032 mm 2 , d 4 = 2.267 mm; s 5 = 32s 0 = 8.064 mm 2 , d 5 = 3.205 mm; s 6 = 64s 0 = 16.128 mm 2 , d 6 = 4.52 mm. For each branch throttle passage switching valve, a pipe-connected step-by-step direct-acting (internally piloted) type switching solenoid valve with a nominal diameter of 1 / 4 inch is selected.

[0069] Suppose the proportion of O 2 in the mixed gas is a%, then the calculation formula for the digital value of the flow cross-sectional area of O 2 is 127 / 100% × a%, and correspondingly, the calculation formula for the digital value of the flow cross-sectional area of N 2 is 127 - 127 / 100% × a%, where 127 is the maximum digital value of the flow cross-sectional area of the 7-channel binary digital combination gas mixing ratio valve. For example, O 2 and N2 The mixing ratio is O 2 :N 2 = 23%:77%, and the calculated cross-sectional areas of the flow of O 2 and N 2 are 29 and 98 respectively; the cross-sectional area number of the gas flow of O 2 can be split into the number combination of 29 = 1 + 4 + 8 + 16, controlling the branch throttle channels s 0 、s 2 、s 3 and s 4 of O 2 are in the conducting state, s 1 、s 5 and s 6 of O 2 are in the off state, that is, c 0 = c 2 = c 3 = c 4 = 1, c 1 = c 5 = c 6 = 0; correspondingly, the branch throttle channels s 0 、s 2 、s 3 and s 4 of N 2 are in the off state, s 1 、s 5 and s 6 of N 2 are in the conducting state, and the cross-sectional area number of the flow of N 2 is 2 + 32 + 64 = 98. By adopting digital control of the on and off states of the branch throttle channels of the digital combination gas mixing ratio valve V for O 2 , controlling the cross-sectional areas of the flows of O 2 and N 2 of the two gas paths, thereby controlling the output flow rates of the two gas paths of O 2 and N 2 , realizing the digital control of the mixing ratio of the two gas paths of O 2 and N 2 .

[0070] Figure 3-2 is a diagram of a laser welding shielding gas flow control system with the function of digitally controlling the mixing ratio of CO 2 and Ar of the two gas paths: It is composed of the CO 2 and Ar gas sources 17, pressure reducing valves 18, two-way gas mixing ratio regulators 19, gas output flow control valves V F , flow meters F, pressure gauges P, and gas output nozzles 21 connected by air pipes 13. Among them: The gas output flow control valve VF for controlling the output flow rate of the mixed gas; the flowmeter F and the pressure gauge P are installed at an easily observable position on the laser welding equipment for measuring and indicating the output gas flow rate value and the pressure value near the nozzle; the nozzle 21 is a component of the laser welding head; the two-way gas mixing ratio controller 19 is as Figure 3 shown, and is composed of a pressure balance unit PBU and a digital combined gas mixing ratio valve V. V is a Figure 1-1 7-channel binary digital combined gas mixing ratio valve, and each branch throttle channel switching valve thereof is selected as a pipe-connected direct-acting switching solenoid valve with a nominal diameter of 1 / 4 inch. By adopting digital control of each branch throttle channel switching valve of the digital combined gas mixing ratio valve V to control the on and off states of CO 2 , the cross-sectional areas of the CO 2 and Ar two-way gas flows are controlled, so as to control the output flow rates of the CO 2 and Ar two-way gases, and the digital control of the mixing ratio of the CO 2 and Ar two-way gases is realized.

[0071] It should be noted that: (1) In the above embodiments, only when the cross-sectional area of the digital combined gas mixing ratio valve is taken as 32 mm 2 (Note: equivalent to a nominal diameter of 1 / 4Taking the valve with an inch (the valve) as an example to illustrate the method for calculating the throttling flow cross-sectional area of each branch throttling channel and the aperture of the throttling hole of the digital combined gas mixing ratio valve. In actual applications, it is not limited to this specific flow cross-sectional area. The flow cross-sectional area of the digital combined gas mixing ratio valve should be selected according to the rated gas flow demand, and the number of parallel branch throttling channels of the digital combined gas mixing ratio valve should be determined in combination with the requirements of discrete digital approximation of gas pressure and flow to continuously calculate and determine the throttling flow cross-sectional area of each parallel branch throttling channel and the aperture of its throttling hole; (2) This invention mainly focuses on the description of features and does not mention the sealing ring or gasket. In fact, there are sealing rings or gaskets at the joint surfaces between the valve body of the digital combined gas mixing ratio valve and each parallel branch throttling channel switching valve, between the switching valve body and its valve core, etc. to prevent gas leakage; nor does it describe the control circuit of the digital combined gas mixing ratio valve. In fact, a control circuit should be set for the digital control digital combined gas mixer or the working position state of each branch throttling channel switching valve of the digital combined gas mixing ratio valve should be directly controlled by the controller of the application device (such as a laser cutting or welding device); (3) According to the gas mixing ratio, calculate and set the flow cross-sectional area numbers of the two-way gas digital combined gas mixing ratio valve. Considering the differences in the influence of gas flow resistance of different throttling hole diameters, the mixing ratio of the actual output mixed gas may not exactly equal the set gas mixing ratio, but this usually does not affect the application. If it is required that the mixing ratio of the actual output mixed gas exactly equals the set gas mixing ratio, then it is necessary to pre-measure and calibrate the mixing ratio of the actual output mixed gas corresponding to the flow cross-sectional area numbers of the ratio valve, and appropriately finely adjust the aperture size of the throttling holes of each branch throttling channel of the ratio valve to ensure that the mixing ratio of the actual output mixed gas exactly equals the set gas mixing ratio.

[0072] It should also be noted that the digital combined gas mixing ratio valve described in this invention is not limited to the configuration examples, structural feature examples, and application examples of the discrete digital throttling flow cross-sectional area described in this specification. Any gas mixing ratio device such as a gas mixer, a gas mixing cabinet, a gas mixing box, etc. that involves a digital combined gas mixing ratio valve using the concept of this invention and uses it as a gas mixing ratio control valve should be within the protection scope of this invention.

Claims

1. Digital combined gas mixing and proportioning valve, characterized in that: The invention is composed of a two-way gas inlet shunt channel, a converging mixed outlet channel and a plurality of two-way switching conduction branch throttling channels connected in parallel therebetween; each branch throttling channel is composed of a two-way switching conduction valve (referred to as a switching valve) and a throttling hole in series; the switching valve has two air inlets respectively connected to the two-way gas inlet shunt channel, and one air outlet connected to the converging mixed outlet channel through the throttling hole; the switching valve has two working positions, and each working position has only one air inlet and one air outlet connected, that is, when in one working position, the first air in the two-way gas is The air inlet and outlet of the first gas channel are connected, while the air inlet and outlet of the second gas channel are closed. When the second gas channel is in another working position, the air inlet and outlet of the second gas channel are connected, while the air inlet and outlet of the first gas channel are closed. Each branch throttling channel has a discrete digital throttling flow cross-sectional area, which is determined by the size of its throttling hole and is an integer multiple of the minimum flow cross-sectional area. The ratio of the throttling flow cross-sectional area of ​​each branch throttling channel to the minimum flow cross-sectional area is used as its flow cross-sectional area number. By controlling the working position of each switching valve, each branch throttling channel The throttling flow cross-sectional areas of the channels are combined to form different flow cross-sectional areas for each gas path. Correspondingly, the flow cross-sectional area numbers of each branch throttling channel are combined to form different flow cross-sectional area numbers for each gas path. The flow cross-sectional area of ​​each gas path is the sum of the flow cross-sectional areas of the branch throttling channels that are in a conducting state for that gas path. Correspondingly, the flow cross-sectional area number of each gas path is the sum of the flow cross-sectional area numbers of the branch throttling channels that are in a conducting state for that gas path. When all branch throttling channels are conducting to one of the gases, the flow cross-sectional area number thereof takes the maximum flow cross-sectional area number. At this time, the other gas is in a shut-off state, and its flow cross-sectional area is 0; under the premise of balanced intake pressure, the two gases are respectively input from their respective intake diversion channels, and the working positions of the switching valves are digitally controlled by the switch quantity according to the gas mixing ratio, and the flow cross-sectional area of ​​each gas is combined to form a digital form, thereby controlling the output flow of the two gases, and finally the two gases enter the converging mixed gas outlet channel, and the mixed gas is output after mixing; the digital combined gas mixing ratio valve is applied to the field of gas mixing ratio, and is suitable for dynamic and real-time changes in the ratio, and can be mixed and used immediately.

2. The digital combined gas mixing and proportioning valve according to claim 1, characterized in that: A specific configuration example of each branch throttling channel having a discrete digital throttling flow cross-sectional area is that the flow cross-sectional area of ​​the throttling hole of each branch throttling channel is s0, s1, s2, ..., s i ,…,s (n-1) , which is 2 times the minimum flow cross-sectional area s0 0 , 2 1 , 2 2 , …, 2 i , …, 2 (n-1) Multiple, 2 i is a binary bit weight, i is 0, 1, 2, ..., n-1, n is the number of branch throttling channels, and it is called an n-channel binary digital combination gas mixing and proportioning valve; the flow cross-sectional area S1 of the first gas in the two gas paths is equal to the sum of the throttling flow cross-sectional areas of the branch throttling channels in the conducting state for the gas path, that is, S1 = c0s0 + c1s1 + ... + c i s i +…+c n-1 s n-1 =(2 0 c0+2 1 c1+…+2 i c i +…+2 n-1 c n-1 )s0, correspondingly, the second gas flow cross-sectional area S2 = (2 n -1)s0-S1, where: s0 is the minimum throttling flow cross-sectional area in the branch throttling channel; c i Indicates the conduction position state value of the i-th branch throttling channel switching valve, which can be 0 or 1. 0 means that the i-th branch throttling channel is in the closed state for the first gas and in the conducting state for the second gas. 1 means that the i-th branch throttling channel is in the conducting state for the first gas and in the closed state for the second gas. The cross-sectional area of ​​the first gas flow is the ratio of the cross-sectional area of ​​the first gas flow S1 to the minimum throttling cross-sectional area s0 S1 / s0 = 2 0 c0+2 1 c1+…+2 i c i +…+2 n-1 c n-1 , each branch throttling channel c i The values ​​are different, and the numbers are combined to form 0, 1, 2, 3, ..., (2 n -1)Total 2 n The flow cross-sectional area numbers correspond to 0, 1s0, 2s0, 3s0, ..., (2 n -1)s0 of 2 n The discrete digital approximation of the continuous flow cross-sectional area, the corresponding second gas flow cross-sectional area is S2 / s0 = (2 n -1)-S1 / s0, the corresponding digital combination forms (2 n -1), ..., 3, 2, 1, 0, 2 in total n The flow cross-sectional area number corresponds to (2 n -1)s0, ..., 3s0, 2s0, 1s0, 0 of 2 n The discrete digital approximation of the continuous flow cross-sectional area.

3. The digital combined gas mixing and proportioning valve according to claim 1, characterized in that: A structural example of the switching valve is composed of a valve body, a cylindrical piston valve core and its driving components, wherein the valve body is provided with a valve core sliding channel, and the valve body has two air inlets and one air outlet; the valve core has two working positions when sliding in the valve body, when in one working position, the first air inlet and the air outlet are connected, and the second air inlet and the air outlet are closed, and when in the other working position, the second air inlet and the air outlet are connected, and the first air inlet and the air outlet are closed; the valve core driving components include direct-acting electromagnetic driving type, step-by-step direct-acting (internal pilot) electromagnetic driving type, and micro-electromagnetic valve controlled pilot gas driving type; the installation categories of the switching valve involved include pipe-connected type and cartridge valve type.

4. The digital combined gas mixing and proportioning valve according to claim 1, characterized in that: A simple structural example form of a switching valve connected by a gas pipe and a three-way pipe joint can be used, and a compact integrated valve body structural example form of a clamp-on type, a pipe-on type, a cartridge valve type or a cartridge valve core type is preferably used: The clamping structure is composed of a two-way gas inlet diversion channel valve body, a converging mixed gas outlet channel valve body, a plurality of pipe-connected switching valves and fixing screws; the inlet diversion channel valve body is provided with two-way gas inlet diversion channels and gas input interfaces, and each gas inlet diversion channel is provided with a plurality of spaced-apart diversion holes, which are respectively connected with the gas inlet ports of each branch throttling channel switching valve; the converging mixed gas outlet channel valve body is provided with a converging mixed gas outlet channel and a mixed gas output interface, and the converging mixed gas outlet channel is provided with a plurality of spaced-apart throttling holes, which are respectively connected with the gas outlet ports of each branch throttling channel switching valve; the switching valve of each branch throttling channel is clamped between the inlet diversion channel valve body and the converging mixed gas outlet channel valve body, and is connected and fixed with a plurality of screws; one switching valve controls two channels at the same time. A gas flow switching branch throttling channel, a certain shunt hole of the first gas inlet shunt channel, the first gas inlet on the switching valve connected thereto, the gas outlet of the switching valve, and the throttling hole on the converging and mixing gas outlet channel connected thereto constitute a branch throttling channel for the first gas flow, and similarly, a certain shunt hole of the second gas inlet shunt channel, the second gas inlet on the switching valve connected thereto, the gas outlet of the switching valve, and the throttling hole on the converging and mixing gas outlet channel connected thereto constitute a branch throttling channel for the second gas flow; a plurality of two-way switching branch throttling channels are connected through the two-way gas inlet shunt channel and the converging and mixing gas outlet channel, constituting a plurality of two-way gas switching branch throttling channels connected in parallel of the digital combined gas mixing and proportioning valve; The pipe-connected structure is composed of a two-way gas inlet and outlet channel valve body, a converging and mixing outlet channel valve body, a plurality of pipe-connected switching valves and an air pipe; the inlet and outlet channel valve body is provided with two-way gas inlet and outlet channel and its gas input interface, each gas inlet and outlet channel is provided with a plurality of spaced-apart diversion hole pipe interfaces, which are respectively connected with the gas inlet of each branch throttling channel switching valve through the air pipe; the converging and mixing outlet channel valve body is provided with a converging and mixing outlet channel and its mixed gas output interface, the converging and mixing outlet channel is provided with a plurality of spaced-apart throttling hole pipe interfaces, which are respectively connected with the outlet of each branch throttling channel switching valve through the air pipe; the switching valve of each branch throttling channel is located between the inlet and outlet channel valve body and the converging and mixing outlet channel valve body; one switching valve simultaneously controls the flow of two gases A switching and conducting branch throttling channel, a certain diversion hole pipe interface of the first gas inlet diversion channel, the first gas inlet on the switching valve connected thereto, the gas outlet of the switching valve, and the throttling hole pipe interface on the converging and mixing gas outlet channel connected thereto with the gas outlet of the switching valve, constitute a branch throttling channel for the first gas flow, and similarly, a certain diversion hole pipe interface of the second gas inlet diversion channel, the second gas inlet on the switching valve connected thereto, the gas outlet of the switching valve, and the throttling hole pipe interface on the converging and mixing gas outlet channel connected thereto with the gas outlet of the switching valve constitute a branch throttling channel for the second gas flow; a plurality of two-way switching and conducting branch throttling channels are connected through the two-way gas inlet diversion channel and the converging and mixing gas outlet channel, constituting a plurality of two-way gas switching and conducting branch throttling channels connected in parallel of the digital combined gas mixing and proportioning valve; The cartridge valve structure is composed of a valve body and a plurality of cartridge switching valves; the valve body is provided with two-way gas inlet and outlet flow channels and their gas input interfaces, a converging and mixing outlet flow channel and their gas output interfaces, and a plurality of inserting and mounting threaded holes for the cartridge switching valves arranged at intervals; each of the inserting and mounting threaded holes has two flow diversion holes respectively connected to the two-way gas inlet and outlet flow channels, and a throttling hole connected to the converging and mixing outlet flow channel; the cartridge switching valve is inserted into the mounting threaded hole and fixed on the valve body; a switching valve simultaneously controls the switching conduction of the two-way gas flow branch throttling channels, and each of the first gas flow diversion holes in the inserting and mounting threaded holes and the corresponding gas flow diversion holes are connected to the first gas flow diversion holes in the inserting and mounting threaded holes. The first gas inlet of the plug-in switching valve connected thereto, the gas outlet of the plug-in switching valve, and the throttle hole in the mounting threaded hole constitute a branch throttling channel for the flow of the first gas. Similarly, the second gas diversion hole in the mounting threaded hole, the second gas inlet of the plug-in switching valve connected thereto, the gas outlet of the plug-in switching valve, and the throttle hole in the mounting threaded hole constitute a branch throttling channel for the flow of the second gas. A plurality of two-way switching conduction branch throttling channels are connected through the two-way gas inlet diversion channel and the converging mixing outlet channel to constitute a plurality of two-way gas switching conduction branch throttling channels connected in parallel of the digital combined gas mixing and proportioning valve. The cartridge valve core structure is composed of a valve body and a plurality of two-way switching conduction cartridge valve cores; the valve body is provided with two-way gas inlet and shunt channels and their gas input interfaces, a converging and mixing outlet channel and their gas output interfaces, and a plurality of intervally arranged cartridge valve core sliding channels; each of the cartridge valve core sliding channels has two shunt holes respectively connected to the two-way gas inlet and shunt channels, and a throttling hole connected to the converging and mixing outlet channel; each cartridge valve core is inserted into a sliding channel, and has two working positions when sliding in the sliding channel. When in one working position, the first gas shunt hole and the throttling hole are connected, and the second gas shunt hole and the throttling hole are closed. When sliding to another working position, the second gas shunt hole and the throttling hole are connected, and the first The two-way gas diversion hole and the throttling hole are closed to form a two-way switching conductor valve; a two-way switching conduction plug-in valve core simultaneously controls the switching conduction of the two-way gas flow branch throttling channels, the first-way gas diversion hole in each sliding channel, the plug-in valve core cylindrical annular groove, and the throttling hole in the sliding channel constitute a branch throttling channel for the first-way gas flow, and similarly, the second-way gas diversion hole in the sliding channel, the plug-in valve core cylindrical annular groove, and the throttling hole in the sliding channel constitute a branch throttling channel for the second-way gas flow; multiple two-way switching conduction branch throttling channels are connected through the two-way gas inlet diversion channel and the converging mixing outlet channel to form multiple two-way gas switching conduction branch throttling channels connected in parallel of the digital combined gas mixing proportioning valve; The throttle holes of each of the two-way gas switching and conducting branch throttling channels can be arranged at the gas outlet of the switching valve.

5. A digital combination gas mixing and proportioning device, including a digital combination two-way gas mixing and proportioning device and a digital combination multi-way gas mixing and proportioning device, characterized in that: The digital combination two-way gas mixing and matching device is mainly composed of a two-way gas pressure balancing unit and the digital combination gas mixing and matching valve described in claim 1. The two-way gas is input from the pressure balancing unit, and the pressure of the two-way gas is equal before mixing and matching through pressure difference balance. Then the two-way gas is input into the digital combination gas mixing and matching valve. According to the mixing and matching ratio of the two-way gas, the flow cross-sectional area of ​​the two-way gas is digitally controlled by the switch quantity, thereby controlling the output flow rate of the two-way gas. Finally, the two-way gas is mixed in the digital combination gas mixing and matching valve and the mixed gas is output; the digital combination multi-way gas mixing and matching device comprises a digital combination two-way gas mixing and matching device which first mixes two of the gases, and then uses the output mixed gas as one gas, and then uses another digital combination two-way gas mixing and matching device to mix it with another gas, and so on, forming a digital combination multi-way gas mixing and matching device, which is applied to the mixing and matching of multiple gases.

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