RU2046394C1 - Apparatus for stabilizing gas pressure - Google Patents

Abstract

FIELD: machine engineering. SUBSTANCE: apparatus includes arranged in the housing 28: the inlet chamber 1 with an input valve (gate 2-nozzle 3), the output chamber 4 with the diaphragm 5, the rod 6, the booster chamber 7 with an input system nozzle 8 gate 9, the last being made of magnetostrictive material, the coil 10, the magnetizing device 11(a permanent magnet), the adjusting screw 12. The output chamber has the nozzle 13, the gate 14, the coil 15, the adjusting screw 17, forming the gap S₂.. The housing of the apparatus is provided by the chamber 18 of the pressure pickup 25, the chamber 18 being connected with the third input of the control unit 24, whose first and second inputs are connected respectively with the coils 10, 15 of the input and output valves of the booster chamber 7. EFFECT: enhanced accuracy of gas pressure stabilization. 1 cl, 1 dwg

Description

 The invention relates to mechanical engineering, in particular to pneumatic devices for stabilizing the pressure of gas (air) for pneumatic measuring devices.

 A device for pressure stabilization [1] is known, comprising a housing divided by a membrane into two chambers, the first of which has a task spring connected to the membrane, and the second is connected to the inlet and outlet nozzles through a regulating body, the shutter of which is made at the first end of the rod. Improving the accuracy and simplification of the device is achieved by the fact that a permanent magnet is installed in the second chamber, the membrane has a rigid center of soft magnetic material, the rod is installed in the first chamber, and its second end is connected to the regulating organ switching means fixed to the housing, while at the first end of the rod a shutter is made, forming a nozzle-shutter element with an inlet pipe. Using the effect of changing the magnet's attractive force depending on the distance to the attracted object allows you to combine the amplification and output chambers of the device.

 However, such a combination in the case of a small value of the input gap leads to a strong influence of the permanent magnet on the sensitivity of the stabilizer, which makes it difficult to set the optimal operational values: the gaps, the distances between the active elements of the circuit, and most importantly to ensure their optimal force interaction. This factor is especially undesirable in the manufacture and debugging of a large batch of devices.

 There is also known a device for stabilizing pressure [2] adopted as a prototype of the invention and comprising a housing, an inlet chamber with an inlet nozzle, an outlet chamber with an outlet nozzle, a control valve connected to the spring-loaded element by means of a rod, an amplification chamber with a permanent magnet, the movable armature of which the stem is connected to the sensing element. In this scheme, an increase in sensitivity is much simpler, since the position of the magnet is more specific.

 However, since the device’s scheme does not use the effect of throttling the passage openings, especially in the inlet pipe, ensuring sensitivity due to restrictions on the characteristics of the spring-magnetic system becomes difficult to achieve due to the inability to control the gap in the outlet pipe, which ultimately affects accuracy of pressure stabilization.

 The aim of the invention is to increase the sensitivity of the device.

 The goal is achieved due to the fact that in a device comprising a housing, an inlet chamber with an inlet pipe, an outlet chamber with an outlet pipe, a control valve connected to the sensing element by means of a rod, an amplification chamber with a permanent magnet, according to the invention, the magnet is mounted on the inlet flaps and output valves of the amplification chamber made of magnetostrictive material and bearing control coils associated with the first and second inputs of the control unit, to the third input of which are connected ene pressure sensor.

 The drawing shows the inventive device.

It consists of an inlet chamber 1, an inlet valve, consisting of a shutter 2 and a nozzle 3, an outlet chamber 4 with a diaphragm 5 connected by a rod 6 to the shutter 2, an amplification chamber 7 including an inlet nozzle-shutter system consisting of a nozzle 8, a shutter 9 made of magnetostrictive material, a coil 10, a magnetizing device 11 (permanent magnet or coil), an adjusting screw 12 that moves the shutter 9 during the initial adjustment and installation of the gap S ₁ . The output nozzle-damper system of the amplification chamber is similar to the input system and consists of the same functional elements: nozzle 13, shutter 14, coil 15, magnetizing device 16, adjusting screw 17 making up the gap S ₂ . The pressure sensor chamber 18 is connected to the outlet pipe 19 by a pipe 20. The inlet pipe 21 supplies pressure to the inlet chamber 1 through the pipe 22 and to the nozzle 8 of the amplification chamber through the pipe 23. The control unit 24 is electrically connected to the pressure sensor 25 and the coils 10 and 15. Damper 9 and 14 during adjustments move in the guides 26 and 27 of the housing 28, respectively. The dampers 9 and 14 of the nozzle-throttle elements are rods of magnetostrictive material and take a certain length under the action of magnetic fields of devices 11 and 16. The coils 10 and 15, when turned on from the control unit 24, change the length of the rods of the shutters 9 and 14, thereby changing the size of the gaps S ₁ and S ₂ . The adjusting screws 12 and 17 serve for the initial installation of the gaps S ₁ and S ₂ in the device.

 The device operates as follows.

In the initial state, the gaps S ₁ and S _{2 are} determined by the length of the shutter rods, which are under the action of only the magnetic field of the magnetization devices (permanent magnets 11 and 16), and are equal to S _1n and S _2n, respectively. Under the action of the magnetic field of the coils 10 and 15, which coincides in direction with the magnetic field of the magnetization devices, the maximum total magnetic field arises, which causes the maximum shortening of the shutters 9 and 14, and therefore the maximum value of the gaps S _1max and S _2max . Under the action of the magnetic field of the coils opposite in the direction of the magnetic field of the magnetization devices, the differential magnetic field causes an extension of the shutter rods and a decrease in the gaps to S _1min and S _2min close to zero.

Gas from the power source through the pipe 21 enters the inlet chamber 1 through the pipe 22 and the amplification chamber 7 through the pipe 23. Passing through the gaps S _1n and S _2n into the chamber 18 of the pressure sensor 25, it triggers the latter, as a result of which the control unit 24 delivers current of a certain direction and force to the coils 10 and 15, thereby causing a change in the gaps S ₁ and S ₂ . Changing the gaps causes a sharp change in pressure in the amplification chamber, while the diaphragm 5 through the rod 6 changes the position of the shutter 2 relative to the nozzle 3 in the inlet chamber, thereby adjusting the pressure in the outlet chamber 4 and the pipe 19 to a value set by the sensor 25.

где h давление в усилительной камере;
Н давление на входе усилительной камеры;
F₁ и F₂ площади проходного сечения зазоров S₁ и S₂, согласно которой одновременное изменение обоих зазоров вызывает более резкое падение давления в измерительной камере, а значит, и более быстрое восстановление давления на входе.The device is based on the dependence
h

where h is the pressure in the amplification chamber;
N pressure at the inlet of the amplification chamber;
F ₁ and F _{2 are} the passage cross-sectional areas of the gaps S ₁ and S ₂ , according to which a simultaneous change in both gaps causes a sharper pressure drop in the measuring chamber, and hence a faster restoration of the inlet pressure.

 The device is in two modes of operation.

The pressure in the output chamber is greater than the level set by the sensor 25. By its signal, the control unit supplies an electric signal of the required polarity and force to the coils 10 and 15, as a result of which the resulting total and difference magnetic fields set the gaps S ₁ S _1min ≃ 0 and S ₂ S _2max . The pressure in the amplifier chamber drops sharply, the diaphragm 5 rises, the valve 2 closes and the pressure in the output chamber 4 drops to the value set by the sensor 25.

The outlet pressure is less than the level set by the sensor 25. In this case, the control unit closes the gap S ₂ S _2min ≃ 0 and opens the gap S ₁ S _1max , the pressure in the amplifier chamber rises, valve 2 opens and the outlet pressure returns to the set value.

Claims (1)

 DEVICE FOR STABILIZING GAS PRESSURE, comprising a housing with inlet and outlet nozzles and inlet and outlet chambers, between which a control valve is installed, connected through the stem with a sensing element forming a control chamber with the housing, characterized in that, in order to increase the sensitivity of the regulator, an output pressure sensor and a control unit are installed in it, the control chamber is connected to the inlet and outlet nozzles, respectively, through the first and second variable chokes, the valves of which are installed are mounted on rods of magnetostrictive material, which are the cores of electromagnets, the coils of which are connected respectively to the first and second outputs of the control unit, the input of which is connected to the output pressure sensor.