阅读说明：本技术 一种防爆型数字化电控液压执行机构 (Explosion-proof digital electric control hydraulic actuating mechanism ) 是由 常海城 于 2019-11-11 设计创作，主要内容包括：本发明公开了一种适用于含氢环境,防爆等级达到Ex d e II C T6的数字化电控液压执行机构,执行机构包含具备内隔爆设计的两位三通高速电磁阀阀室、具备外隔爆设计的防爆外壳；执行机构通过两位三通高速电磁阀对负载设备实现数字化控制。防爆外壳内部分隔成：隔爆外室、隔爆内室；两位三通高速电磁阀阀室具备内隔爆设计,其与防爆外壳的接合面采用端面密封接触配合,结合面长度及接合面间隙符合隔爆等级要求；电磁阀驱动电路板部件设置于隔爆内室内；接线端子排设置于隔爆外室内；防爆穿线套设置于隔爆内室和隔爆外室之间的隔断上；阻燃电缆线穿过防爆穿线套连接电路板部件和接线端子排；防爆穿线套上的螺纹端内填充成型阻燃橡胶。(The invention discloses a digital electrically-controlled hydraulic actuator which is suitable for a hydrogen-containing environment and has an explosion-proof grade reaching Ex d e II C T6, wherein the actuator comprises a two-position three-way high-speed solenoid valve chamber with an inner explosion-proof design and an explosion-proof shell with an outer explosion-proof design; the actuating mechanism realizes digital control on the load equipment through a two-position three-way high-speed electromagnetic valve. The interior of the explosion-proof shell is divided into: the explosion-proof outer chamber and the explosion-proof inner chamber; the two-position three-way high-speed solenoid valve chamber is provided with an inner explosion-proof design, the joint surface of the two-position three-way high-speed solenoid valve chamber and the explosion-proof shell are in end surface sealing contact fit, and the length of the joint surface and the gap of the joint surface meet the requirement of explosion-proof grade; the electromagnetic valve driving circuit board component is arranged in the explosion-proof inner chamber; the wiring terminal block is arranged in the explosion-proof outer chamber; the explosion-proof threading sleeve is arranged on a partition between the explosion-proof inner chamber and the explosion-proof outer chamber; the flame-retardant cable penetrates through the explosion-proof threading sleeve to be connected with the circuit board part and the wiring terminal strip; and the thread end on the explosion-proof threading sleeve is filled with formed flame-retardant rubber.)

1. A digital electrically-controlled hydraulic actuator suitable for hydrogen-containing environments and with an explosion-proof grade reaching Ex d e II C T6 comprises a two-position three-way high-speed solenoid valve chamber with an inner explosion-proof design and an explosion-proof housing with an outer explosion-proof design; the actuating mechanisms realize digital control on load equipment through the two-position three-way high-speed electromagnetic valve, and for a plurality of groups of actuating mechanisms, RS485 industrial field bus control of a Modbus protocol can be adopted; the method is characterized in that: the explosion-proof shell can cover the circuit board part which generates spark arc; explosion-proof shell internal partitioning has become adjacent in order: the explosion-proof outer chamber and the explosion-proof inner chamber; the two-position three-way high-speed solenoid valve chamber is provided with an inner explosion-proof design, the joint surface of the two-position three-way high-speed solenoid valve chamber and the explosion-proof shell are in end surface sealing contact fit, and the length of the joint surface and the gap of the joint surface meet the requirement of explosion-proof grade; the electromagnetic valve driving circuit board component is arranged in the explosion-proof inner chamber; the wiring terminal block is arranged in the explosion-proof outer chamber; the explosion-proof threading sleeve is arranged on a partition between the explosion-proof inner chamber and the explosion-proof outer chamber; the flame-retardant cable penetrates through the explosion-proof threading sleeve to be connected with the circuit board part and the wiring terminal strip; the thread end on the explosion-proof threading sleeve is filled with formed flame-retardant rubber; a lead perforation for arranging the flame-retardant cable is arranged in the molded flame-retardant rubber; the flame-retardant cable at the port of the explosion-proof threading sleeve is filled and fixed by glue pouring materials; the explosion-proof threading sleeve is fixed on the partition between the explosion-proof inner chamber and the explosion-proof outer chamber through gluing treatment; an internal grounding assembly and an external grounding assembly are arranged on the explosion-proof shell.

2. The flameproof digital electric control hydraulic actuating mechanism of claim 1, characterized in that: the two-position three-way high-speed solenoid valve chamber with the internal explosion isolation design characteristic comprises a valve chamber shell, a solenoid valve body, an electromagnetic coil, a cylindrical valve core with a conical surface seal, an oil inlet, an oil outlet and a control port, wherein the cylindrical valve core is connected with an armature into a whole through a connecting screw; the valve core is matched in the oil cavity in the valve body; the oil inlet, the oil outlet and the control port are communicated with the oil cavity; the electromagnetic coil drives the armature and the valve core to stretch; and the wiring terminal of the electromagnetic coil of the two-position three-way high-speed electromagnetic valve is connected to the circuit board component.

3. The flameproof digital electric control hydraulic actuating mechanism according to claim 2, characterized in that: the explosion-proof shell and the matching surface of the two-position three-way high-speed solenoid valve chamber form an outer explosion-proof joint surface, the width L of the explosion-proof joint surface is not less than 12.6mm or other equivalent widths, and the explosion-proof clearance (diameter difference) ic of the joint surface is not less than 0.15mm or other equivalent clearance values.

4. The flameproof digital electric control hydraulic actuating mechanism according to claim 2, characterized in that: an inner explosion-proof joint surface is formed by the valve body of the two-position three-way high-speed electromagnetic valve and the joint surface of the valve chamber shell of the two-position three-way high-speed electromagnetic valve, the width L of the explosion-proof joint surface is not less than 14.5mm or other equivalent widths, and the explosion-proof clearance (diameter difference) ic of the joint surface is not less than 0.15mm or other equivalent clearance values.

5. The flameproof digital electric control hydraulic actuating mechanism according to claim 2, characterized in that: an inner explosion-proof joint surface is formed by the valve body of the two-position three-way high-speed electromagnetic valve and the joint surface of the valve core of the two-position three-way high-speed electromagnetic valve, the width L of the explosion-proof joint surface is not less than 9.5mm or other equivalent widths, and the explosion-proof clearance (diameter difference) ic of the joint surface is not less than 0.005mm and not more than 0.01mm or other equivalent clearance values; the valve core is connected with the armature into a whole through a connecting screw, the connecting screw thread is an explosion-proof screw thread, the precision is not lower than 6H/6g, and the screw pitch is not smaller than 0.7 mm.

Technical Field

The invention relates to the technical field of digital electric control hydraulic pressure, and provides an electric control hydraulic actuator for an explosive gas environment.

Background

The stepless air volume adjusting system of the large reciprocating compressor adopts a two-position three-way high-speed electromagnetic valve as a core component of a stepless adjusting actuating mechanism, a valve controller sends a control signal to realize the valve position switching of the two-position three-way electromagnetic valve, hydraulic energy is converted into mechanical energy, controllable delay closing of an air inlet valve is realized, and air volume which does not need to be compressed is returned, so that the load of the compressor is continuously and stably adjusted. According to the requirements of the explosive gas environment used by the compressor, the stepless air volume adjusting actuating mechanism assembly must obtain qualified explosion-proof certification, and has perfect outer explosion-proof design and inner explosion-proof design so as to improve the use safety of products and meet the explosion-proof specification and use requirements of petrochemical and chemical fields.

As a core component of the stepless air flow adjusting actuating mechanism, when the two-position three-way high-speed electromagnetic valve operates normally, the PCB driving circuit board component capable of generating arc sparks is arranged in the explosion-proof shell, the explosion-proof shell bears the internal explosion pressure without loss, and the energy can be reduced when the internal flame gas is transmitted through the gap, so that the explosive gas outside the shell cannot be detonated, and the use safety of the product is improved. The two-position three-way high-speed electromagnetic valve assembly is called a valve chamber, and the valve chamber is also provided with a perfect internal explosion isolation structure, so that when internal flame gas is transmitted through gaps of all joint surfaces, energy can be reduced, and oily volatile gas in the valve chamber or leaked dangerous process gas can be prevented from being ignited.

Disclosure of Invention

The invention aims to: the explosion-proof design structure of the digital electrically-controlled hydraulic actuating mechanism for the explosive gas environment with the explosion-proof level reaching Ex d e II C T6 is provided, and the problem to be solved is to provide a compressor stepless air quantity adjusting actuating mechanism which can meet the explosion-proof requirement of II area C in the petrochemical and chemical fields.

1. The technical scheme of the invention is as follows: a compressor stepless air volume adjusting actuating mechanism for explosive gas environment with explosion-proof grade reaching Ex d e II C T6 comprises a two-position three-way high-speed electromagnetic valve assembly, and a plurality of slave machines are controlled by a ModbusRS485 industrial bus; the explosion-proof shell comprises a circuit board component which can cover and generate spark arc; explosion-proof shell internal partitioning has become adjacent in order: the explosion-proof outer chamber and the explosion-proof inner chamber; the two-position three-way high-speed solenoid valve chamber is provided with an inner explosion-proof design, the joint surface of the two-position three-way high-speed solenoid valve chamber and the explosion-proof shell are in end surface sealing contact fit, and the length of the joint surface and the gap of the joint surface meet the requirement of explosion-proof grade; the electromagnetic valve driving circuit board component is arranged in the explosion-proof inner chamber; the wiring terminal block is arranged in the explosion-proof outer chamber; the explosion-proof threading sleeve is arranged on a partition between the explosion-proof inner chamber and the explosion-proof outer chamber; the flame-retardant cable penetrates through the explosion-proof threading sleeve to be connected with the circuit board part and the wiring terminal strip; the thread end on the explosion-proof threading sleeve is filled with formed flame-retardant rubber; a lead perforation for arranging the flame-retardant cable is arranged in the molded flame-retardant rubber; the flame-retardant cable at the port of the explosion-proof threading sleeve is filled and fixed by glue pouring materials; the explosion-proof threading sleeve is fixed on the partition between the explosion-proof inner chamber and the explosion-proof outer chamber through gluing treatment; an internal grounding assembly and an external grounding assembly are arranged on the explosion-proof shell.

Preferably, the two-position three-way high-speed electromagnetic valve comprises a valve body, an electromagnetic coil, a valve core, an oil inlet, an oil outlet and a control port; the valve core is connected with the armature into a whole through a connecting screw and is matched in an oil cavity in the valve body; the oil inlet, the oil outlet and the control port are communicated with the oil cavity; the electromagnetic coil drives the valve core to stretch and reciprocate; and the wiring end of the two-position three-way high-speed electromagnetic valve is connected to the wiring terminal of the driving circuit board component.

Preferably, the width of the matching surface of the explosion-proof shell and the valve body is 19mm or other equivalent widths.

Preferably, the thickness of the flame retardant rubber layer is 1mm or other equivalent thickness and the width of the flame retardant rubber layer is 9mm or other equivalent width.

The invention has the advantages that:

1. the scheme has the advantages of compact structure, quick response, accurate action, good repeatability, strong pollution resistance, small internal leakage and high reliability, and has the most remarkable characteristic that the product can directly receive digital signals to realize high-speed control on linear motion of the hydraulic plunger.

2. The product of the scheme improves the explosion-proof grade of the stepless actuating mechanism, the explosion-proof grade reaches Ex d e II C T6, the explosion-proof requirement on electrical equipment under a hydrogen environment is met, and the problem of the inner and outer explosion-proof design of the high-speed electromagnetic valve assembly of the stepless actuating mechanism is solved.

Drawings

The invention is further described with reference to the following figures and examples:

FIG. 1 is a cross-sectional view of an explosion-proof digital electric control hydraulic actuator;

FIG. 2 is an enlarged view of a portion of region II of FIG. 1;

FIG. 3 is an enlarged view of a portion of region I of FIG. 1;

FIG. 4 is a cross-sectional view of section B-B of FIG. 3;

FIG. 5 is an external side view of a compressor stepless air volume adjustment actuator for an explosive gas environment;

FIG. 6 is an external front view of a stepless air volume adjusting actuator of a compressor for explosive gas environment;

wherein: 1. a top cover; 2. a gasket; 3. an explosion-proof housing; 4. a terminal assembly; 5. a nut; 6. cold pressing joint components; 7. a valve chamber (containing a high-speed solenoid valve body); 8. metric damping isolation columns; 9. a circuit board; 10. a full metal hexagonal lock nut; 12. a cable gland head; 13. an inner ground pad; 14. a gasket; 15. a socket head cap screw; 16. a cross recessed pan head screw; 20. a square gasket; 21. a square gasket; 22. a flame retardant cable wire; 23. a wire passing plug; 24. a plug screw; 25. threading the wire sleeve; 26. an epoxy resin; 27. a coil housing; 28. a coil cover; 29. a PET material; 30. an electromagnetic coil; 31. an iron core assembly; 32. inner hexagon countersunk head screws; 33. a valve core; 34. a base assembly; 35. a valve body; 36. a valve housing; 39. an internal ground plate.

Detailed Description

The preferred embodiment of the present invention:

the stepless air flow adjusting and executing mechanism of the compressor for the explosive gas environment comprises a two-position three-way high-speed electromagnetic valve controlled by a Modbus RS485 industrial bus, wherein the two-position three-way high-speed electromagnetic valve comprises a valve body, an electromagnetic coil, a valve core, an oil inlet, an oil outlet and a control port. The valve core is matched in the oil cavity in the valve body, and the oil inlet, the oil outlet and the control port are communicated with the oil cavity. The solenoid drives the valve core to stretch and contract to control the on-off of the oil cavity and the oil outlet.

In order to meet the safety of the two-position three-way high-speed electromagnetic valve in an explosive gas environment, an external explosion-proof design is added outside the two-position three-way high-speed electromagnetic valve, and an internal explosion-proof design is added in the two-position three-way high-speed electromagnetic valve.

The specific structure is shown in fig. 1 to 5, and the technical points of the scheme are comprehensively shown. As shown in fig. 1, the leftmost side is a top cover 1, and the top cover 1 is mounted on an electrical room opening of an explosion-proof housing 3 and is sealed by a gasket 2. The right side of the explosion-proof housing 3 is butted to the valve housing 36, the overlapping length of the valve body 35 and an explosion-proof joint surface at the position of the explosion-proof housing 3 needs to be more than 12.6mm, and the caliber difference of the joint part is less than 0.15 mm.

As shown in fig. 1, the space formed by the explosion-proof housing 3 and the valve body 35 is functionally divided into a valve chamber, a seal chamber, and an electric chamber. The valve chamber is a chamber inside the valve housing 36, the sealing chamber is a chamber between the valve housing 36 and the middle partition of the explosion-proof housing 3, and the electric chamber is a chamber between the middle partition of the explosion-proof housing and the top cover 1. Wherein, the wiring terminal assembly 4 is arranged in the electric room, and the explosion-proof joint is arranged on the partition wall. The flame retardant electrical cable 22 passes through the explosion proof joint for connection to circuit board components and electrical controls in the sealed chamber. In the sealed chamber, a circuit board 9 is fixed to a metric shock-absorbing isolation column 8 on the end face of a valve housing 36 by an all-metal hexagonal locknut 10. A hydraulic actuator 7 is arranged in the valve chamber, and the access end of the hydraulic actuator 7 is connected to the wiring end of a circuit board 9 in the sealed chamber through a nut 5 and a cold-pressing joint assembly 6.

As shown in fig. 2, the hydraulic actuator in the valve chamber comprises an electromagnetic assembly, an electromagnetic coil 30 is embedded in a core assembly 31, the core assembly 31 is injection molded in a PET material 29 (30% glass fiber), the PET material 29 is installed in a coil housing 27 after being sheathed with a coil cover 28, and the valve chamber is arranged outside the coil housing 27. The right side of the PET material 29 is abutted to a base assembly 34, an iron core assembly 31 is axially connected with a valve core 33 through an inner hexagonal countersunk head screw 32, the valve core 33 penetrates through the base assembly 34, and a spring is sleeved on the valve core 33. The valve body 35 is arranged outside the valve core 33, and the valve body 35 is butted with the coil shell 27. The precision of the explosion-proof thread at the position of the inner hexagonal countersunk head screw 32 is not lower than 6H/6g, the thread pitch is not smaller than 0.7mm, the screwing length of the thread is 8mm, and the number of joggles of the thread is larger than 10 mm.

As shown in FIG. 3, a threading sleeve 25 is arranged in the shaft hole of the explosion-proof joint, the threading plug 23 is plugged into the threading sleeve 25, and the flame-retardant cable 22 passes through the threading plug 23. A plug screw 24 is plugged into an opening of the explosion-proof joint, the rear end of the plug screw 24 is embedded between the wire passing plug 23 and the threading sleeve 25, epoxy resin 26 is filled into the opening of the plug screw 24, and the encapsulation length of the epoxy resin is not less than 9mm according to the Q/14D09.1-2010 standard. The length L of the explosion-proof joint surface of the outer surface of the wire passing plug 23 is not less than 16mm, and the matching difference of the outer diameter of the explosion-proof joint surface is not more than 0.15 mm. The precision of the explosion-proof thread on the screw plug is not affected by 6H/6g, the thread pitch is not less than 0.7mm, the screwing length of the thread is 14mm, and the number of joggles of the thread is more than 9 mm.

As shown in fig. 4 and 5, an external ground terminal is provided on the side surface of the explosion-proof housing, an internal ground terminal is provided on the front surface of the explosion-proof housing, the external ground terminal includes an external ground pad 21, and the internal ground terminal includes an internal ground pad 13. The two grounding gaskets are respectively fixed by a gasket 14, an inner hexagonal socket head cap screw 15 and a square gasket 20 which correspond to each other. A ground label 40 is further provided on the upper side of the external ground terminal, and an internal ground label 39 is provided on the side of the internal ground terminal. Also provided on the front face of the explosion proof housing are a cable gland 12 and an explosion proof grade panel which is secured by cross-recessed pan head screws 16.

By integrating the structure, the scheme has the characteristics that the scheme comprises the following aspects:

1) the size of the matching surface of the explosion-proof shell and the switch electromagnetic valve is designed as follows:

the explosion-proof shell is arranged outside the two-position three-way high-speed electromagnetic valve and is in butt joint with the end part of the two-position three-way high-speed electromagnetic valve. When the high-speed switching electromagnetic valve operates normally, the circuit board component capable of generating spark arcs is arranged in the explosion-proof shell, the explosion-proof shell bears the internal explosion pressure without loss, and the energy is reduced when the internal flame gas is transmitted through the gap, so that the explosive gas outside the shell is not enough to be detonated, and the use safety of the product is improved.

In order to prevent flame gas inside the explosion-proof shell from spreading to the outside of the shell through a gap between the switch electromagnetic valve shell and the explosion-proof shell, the critical parts of the explosion-proof shell are designed into the following dimensions: the width of the matching surface of the switch valve shell and the explosion-proof shell is 19 mm; the minimum value of the wall thickness of the explosion-proof shell is 7 mm.

2) Designing flame-retardant wires and explosion-proof joints:

and selecting a standard explosion-proof joint matched with the size of the explosion-proof shell, and filling the threaded end on the explosion-proof joint with a formed flame-retardant rubber filler or epoxy resin (a lead perforation is reserved in the formed flame-retardant rubber filler or the epoxy resin). Enabling the flame-retardant cable to penetrate through the flame-proof joint through a lead perforation in the molded flame-retardant rubber filler or epoxy resin, reserving a certain length at two ends of the flame-proof joint according to the assembly requirement, and fixing the cable by using a potting compound; and (4) fixing the explosion-proof joint on the explosion-proof shell after the explosion-proof joint is subjected to gluing treatment, thereby completing the installation of the explosion-proof joint. During specific operation, the molded flame-retardant rubber filler is pressed into the explosion-proof joint and then is closed, so that the explosion-proof effect is achieved. The flame-retardant wire is well adjusted and then is filled with the filler, so that the waterproof effect is achieved. Finally, an explosion-proof area is formed, thereby playing the roles of explosion prevention and water prevention.

Meanwhile, the top cover of the explosion-proof shell is covered with a layer of flame-retardant rubber with the thickness of 1mm and the width of 9mm, so that the flame-retardant rubber not only can play a flame-retardant role, but also can play a sealing role, and plays a certain protection role in reducing internal energy.

3) The grounding design inside and outside the explosion-proof shell is as follows:

an internal grounding assembly and an external grounding assembly are designed on the explosion-proof shell, and a safety loop is formed after grounding, so that safety accidents such as electric leakage and electric shock are prevented.

4) The inner explosion insulation design of the high-speed electromagnetic valve assembly of the stepless actuating mechanism comprises the following steps:

the inner explosion-proof body is embodied in the design of the inner explosion-proof junction surface, in particular to the structure and the length of the inner explosion-proof junction surface. An inner explosion-proof joint surface is formed by the valve body of the two-position three-way high-speed electromagnetic valve and the joint surface of the valve chamber shell of the two-position three-way high-speed electromagnetic valve, and the width L of the explosion-proof joint surface is not less than 14.5 mm; and the explosion-proof clearance (diameter difference) ic of the joint surface is less than or equal to 0.15 mm. Meanwhile, an inner explosion-proof joint surface is formed by the valve body of the two-position three-way high-speed electromagnetic valve and the joint surface of the valve chamber shell of the two-position three-way high-speed electromagnetic valve, the width L of the explosion-proof joint surface is not less than 9.5mm, and the explosion-proof gap (diameter difference) ic =0.005 mm-0.01 mm of the joint surface.

The following combinations are specifically exemplified to illustrate the "other equivalent values" defined in the above protection ranges:

in conclusion, the stepless air volume adjusting and executing mechanism for the explosive gas environment can ensure that the circuit board component generating spark arcs is completely arranged in the explosion-proof shell when the high-speed switching electromagnetic valve operates normally, the explosion-proof shell bears the internal explosion pressure without loss, and the energy is reduced when the internal flame gas is transmitted through the gap, so that the explosive gas outside the shell is not enough to be detonated, and the use safety of the product is improved. Meanwhile, the inner explosion insulation structure design can reduce energy and prevent oily volatile gas in the valve chamber or leaked dangerous process gas from being ignited when the inner flame gas is transmitted through gaps of the joint surfaces.

Exemplifying a compressor stepless air quantity regulating system applied to an explosive gas environment, and the model is SDEHA-2, the basic performance parameters of a digital electrically-controlled hydraulic actuating mechanism are as follows:

1) working voltage: 20VDC to 28VDC, and a rated voltage of 24 VDC.

2) Working pressure: 8MPa to 14 MPa.

3) The structural form is as follows: the two-position tee is normally open.

4) Working current: a starting current 14A; maintaining the current 4A.

5) Coil resistance: 0.25. omega. +. 0.05. omega. (20 ℃ C.).

6) Insulation resistance: is more than or equal to 100M omega (under 500 VDC).

7) Working temperature: minus 40 ℃ to plus 80 ℃.

8) Protection grade: IP 65.

9) Explosion-proof grade: ex d e II C T6.

10) Explosive gas atmosphere: zone 1 and zone 2.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical concepts disclosed herein be covered by the appended claims.