144results about How to "Uniform movement" patented technology

The invention discloses a patient ferry bed which comprises a vehicle body, wherein the vehicle body is provided with a lifting mechanism and universal casters. The ferry bed that can move horizontally is installed on the vehicle body. The ferry bed comprises a bed board mechanism, a bed head and a bed tail beam mechanism. The patient ferry bed is of a single-layer mobile bed board structure and is simple in structure, needed parts are less, and the patient ferry bed is low in production cost and failure rate and convenient to maintain; the friction force caused by the single-layer mobile bed board structure is very small, a belt does not generate kinetic friction with the bed surface and the body of a patient, a bed sheet cannot be wound up, the safe transfer of the patient is achieved, and secondary injury is avoided; operators almost do not need to be in contact with the patient in the process, and the propagation of infecting bacteria is effectively avoided.

The invention discloses a centralized driving flip-flow screen, which mainly comprises an upper screen box, a lower screen box, an elastic screen stencil formed by connecting a plurality of rectangular screen plates, a driving shaft for connecting the upper and lower screen boxes, a supporting frame, a driving shaft and a belt wheel driving mechanism, wherein the belt wheel driving mechanism is arranged at the middle lower part of the driving shaft, the middle part of the driving shaft is provided with a belt wheel connected with the belt wheel driving mechanism, and the axes at the left and the right of the belt wheel are symmetric and are machined with two eccentric axis sections respectively to form the coaxial four-section eccentric driving shaft; an upper cross beam of the supportingframe is a semi-columnar upper cross beam; the relative motion of the two screen boxes fulfills the deflection motion of the screen stencil so as to realize material screening; and the centralized driving flip-flow screen adopts the structure that the number of the screen hole of the screen surface at the front end is less, the number of the screen hole of the screen surface at the middle sectionis medium and the number of the screen hole of the screen surface of the tail section is more in the aspect of the screen hole arrangement so as to ensure the effects that the screen surface at the front end is not easy to break when conveying the materials and the integral screen surface screens uniformly; and the centralized driving flip-flow screen has the advantages of simple structure, stableoperation, energy consumption conservation, long service life and wide practicability.

The invention relates to a die and a process for cold stretch forming of a B-column high-strength plate of a sedan, belongs to forming processing technology of metallic materials, and aims to effectively solve the technical problem of resilience of the high-strength steel plate during precision forming manufacturing. The die mainly comprises a concave die (3), a convex die (7) and a blank holder (5), wherein the concave die (3) and the convex die (7) are fixed on an upper die holder (4) and a lower die holder (8) respectively; a TD coating is fused on the concave die (3); and the bottom of the blank holder (5) is supported by a nitrogen spring (6) which is arranged on the lower die holder (8) and slidably matched with the convex die (7). The process comprises the following steps: a) blanking of technical chips; b) pre-forming of a product; c) realization of R-angle forming through reverse stretching of a workpiece in the pre-forming state; d) edging and punching of the workpiece after reverse stretching; and e) R-angle and surface reshaping of the workpiece after edging and punching.

The invention discloses a parallel dislocation type parallel mechanism capable of three-dimensional translational motion and one-dimensional rotation, and the parallel mechanism comprises a moving platform. The moving platform comprises an upper platform and a lower platform, which are arranged in a horizontal manner; the lower platform consists of a pair of identical angle plates and a pair of parallel connecting rods with equal lengths; two ends of the two parallel connecting rods are rotatably connected with the two angle plates respectively; the two parallel connecting rods and the two angle plates form a structure of parallelogram; the upper platform is connected with the two parallel connecting rods of the lower platform through revolving pairs; the upper platform is parallel with the two angle plates, which are provided with lower connecting shafts; and the moving platform is connected with an end effector through an angle amplification mechanism. The parallel dislocation type parallel mechanism capable of three-dimensional translational motion and one-dimensional rotation has the advantages of comparatively better [good] rigidity and stability, flexible motion, uniform stress and a long service lifetime, is capable of high speed grab, and meets the requirement of complex operations of grab and release.

The invention discloses a jetting glue dispensing valve device and a jetting glue dispensing method. The jetting glue dispensing valve device comprises a jetting glue dispensing valve, a glue supply pipeline and a glue supply valve, wherein a turntable capable of being closed / opened quickly is mounted at the bottom of the glue supply valve. During a glue jetting course, the glue supply valve is closed, and a channel allowing a glue solution to flow back to the glue supply valve from the glue supply pipeline is intercepted, so that glue jetting with precise volume is achieved. After a single glue jetting course is finished, the glue supply valve is opened, and the glue supply channel is opened for filling, so that continuous jetting of the glue solution is achieved. When the device and the jetting glue dispensing method are used for glue dispensing, no backflow occurs, so that an effective utilization rate of striker movement is increased, and jetting of a high-viscosity glue solution is facilitated; the device is simple in structure and easy to process; the turntable has the characteristic of periodic rotation, and can stir the glue solution, so that precipitation of fluorescent powder in the glue solution is avoided effectively; the fluid velocity in the jetting glue dispensing valve is distributed more uniformly; and the glue dispensing quality is ensured.

The invention relates to special precise coating equipment for a medical high-density polyethylene dialyzing paper. The equipment comprises a working frame; the working frame is provided with a winding device, a coating device, a tensioning device and a winding roller in sequence from front to back; the winding roller is wound with a dialyzing paper body; the dialyzing paper body is wound to pass through the winding roller, the tensioning device, the coating device and the winding device in sequence from back to front; and the winding device, the coating device and the tensioning device are matched for use to finish the coating process of the medical dialyzing paper. The equipment can solve such difficulties as weak flexibility of traditional coating equipment, low precision, nonuniform coating, and resource wastes caused by vague coating and overlapped coating in the coating process of a traditional dialyzing paper, can realize precise coating function of the medical dialyzing paper, cannot cause resource wastes, and has such advantages as good flexibility, high precision, uniform coating, clear coating and no overlap.

The invention relates to a polyamide polymerization production process and equipment for the same. The polyamide polymerization production process comprises the following steps of: carrying out prepolymerization on melted caprolactam, titanium dioxide, benzoic acid, and the like at a high temperature, and then carrying out front polymerization and post polymerization; pelleting; pre-extracting; extracting; pre-drying; and drying to obtain a product. The production equipment comprises a hexanolactam melting system, a preparation system, a feed system, a high-temperature prepolymerization device, a front polymerization tower, a rear polymerization tower, a pelleting system, a pre-extraction tower, an extraction tower, a pre-drying tower, a drying tower, and the like. According to the invention, static state flow guide spiral mixer assemblies are additionally arranged in the extraction tower and the lower sections of each row of tubes of the high-temperature prepolymerization device, the front polymerization tower and the post polymerization tower; the polyamide hydrolyzing ring opening and dewatering are more uniform and sufficient and faster; the front polyaddition reaction is sufficient and stable; the rear polycondensation stage is more uniform and stable in molecular distribution; the extraction tower more sufficiently and stably extracts a caprolactam monomer; the pre-drying tower can be used for removing the surface moisture of a slice; the drying tower dries combined water; a recovery system can be used for recovering an oligomer and extracts the caprolactam monomer contained in water.

The invention discloses a plant tissue culture rooting and seedling exercising integrated cultivating device and a cultivating method thereof. The cultivating device comprises a plant cultivation system, an illumination system, a ventilation temperature-control system, a fluid supplying system, a CO2 supplying system and an environment control system. The plant cultivation system comprises a three-dimensional multi-layer cultivation frame and cultivation containers placed on the cultivation frame, each layer of multiple layers of the cultivation frame is provided with one cultivation container, and lifting seedling disc supports are arranged at the bottoms of the containers and used for suspending cultivation plants. The illumination system comprises lamp boxes, LED lamp tubes and fans, and the LED lamp tubes are arranged inside the lamp boxes and connected with the fans to be installed above the cultivation containers in an integrated mode without communication with the cultivation containers. On the premise of guaranteeing that space and time are saved, the cost is low, and the utilization rate of resources is high, the utilization rate of the resources and labor productivity are increased, the cultivation period is shortened, and the production cost is lowered.

The invention discloses a multi-channel dumping grain drying machine. The technical points include that: the lower part of the drying machine is a parallel dumping channel (9) composed of a tetrahedron inverse cone, a multi-channel dumping mechanism (11) is arranged on an elastic support (12), the aggregate bin (14) of the multi-channel dumping mechanism (11) is internally and uniformly provided with support frames (16), the mounting dip angle of the support frame (16) and the horizontal plane is 15-25 degrees. The support frame (16) is provided with metering blocks (10) with the same quantity of that of dumping channels; a distance of 10-50mm is kept between the metering block (10) and the dumping channel port (19) of the parallel dumping channel (9); a levelling grid (2) at the upper part of the drying machine is hung on an elastic hanger (3), the lower end of a guiding rod (4) is connected with a guiding rod support (25) on the metering block (10), the guiding rod (4) penetrates a drying chamber (6) upward from the dumping channel port (19) of the parallel dumping channel (9) of the drying machine, and the guiding rod (4) is connected with the levelling grid (2) at the top of the drying machine. The invention has the advantages that structure is simple, motion of material in the machine is uniform, material drying precipitation is uniform and drying speed is high, and drying quality of material can be fully maintained.

An active coke flue gas purifying system includes an adsorption / regeneration integrated purifying column, a vibrating sieve, a bucket elevator, a material storage bin and a chimney. The adsorption / regeneration integrated purifying column is communicated with the chimney, the vibrating sieve and the bucket elevator respectively. The interior of the adsorption / regeneration integrated purifying column successively includes an adsorption section, an upper tapered material distributor, a regeneration gas exhaust section, a regeneration heating section, a regeneration cooling section and a lower tapered material distributor. The system is in an integrated structure and allows adsorption and regeneration to be completed in one column, so that the system reduces loss of active coke, reduces energy consumption, is highly environment-friendly, allows high-effective synergistic treatment of various pollutants and resource recycling, is small in land occupation area and is low in energy consumption.

The invention discloses an electrospinning-based flexible tensile strain sensor with a spiral wound structure, and a preparation method of the electrospinning-based flexible tensile strain sensor. A sensitive resistor of the product is made of a bifilar helix prepared through twice twisting of a conductive nanofiber membrane prepared through the combination with an electrospinning method. The sensor has relatively high conductivity, still has a conductive property at relatively large tension and large-size tension, has advantages of relatively good toughness, high tensile recovery property, good tensile stability, wide strain withstanding range, simple preparation method and low production cost, and is suitable for large-scale production.

This invention relates to a static discharge protection element structure, in which, a N trap ring is plugged between a Nch Buffer transistor and a guard-ring controlled by the trap to increase the volume resistance of all the transistors, when EDS happens, it is easy for them to enter into an breakdown and conduction state, and all finger transistors can act uniformly and enter into a protection state so as to get a strong protection result quickly.

The invention relates to an iris wave-beam device capable of simulating an infrared target. The device is a movable mechanism which adjusts an imaging area of a thermal imager through adjustment of a clear aperture. The device comprises a box body, a motor, a transmission nut, a connecting rod, a guide rail, diaphragm pieces and a photoelectricity operation control system, wherein the motor, the transmission nut, the connecting rod, the guide rail and the diaphragm pieces are installed in the box body. The diaphragm pieces are two in number, and a side face of each diaphragm piece is provided with a 90-degree notch. The two diaphragm pieces are overlapped, and the 90-degree notches are oppositely arranged to form a square-shaped window which can spread and shrink. The device has the advantages that the diaphragm pieces are easy to machine, assemble and adjust, motion tracks are precise, operation is flexible, interference or inhibition in angle conversion of a motion component can be avoided, the window is precisely located, and uniform and precise motions of diaphragms can be guaranteed.

The invention discloses an L-shaped sealing mechanism in a plastic packaging integrated machine for banknotes. The L-shaped sealing mechanism structurally comprises an L-shaped tool rest with heat seal and a cut-off tool, a tool apron matched with the tool rest and an opening / closing driving mechanism for the tool rest and the tool apron and is characterized in that the tool rest and the tool apron are respectively positioned on an upper guide plate and a lower guide plate, wherein the upper and lower guide plates are limited on a guide pin group for connecting and positioning a base plate and a top plate by means of guide bushes and form degrees of freedom of relatively sliding with guide pins; gear and rack intermediate driving mechanisms which are symmetrically arranged on two sides of the upper guide plate and the lower guide plate are positioned on the base plate by means of a T-shaped frame; a piston rod of an air cylinder on the top plate is fixedly connected with the upper guide plate. During work, the air cylinder drives the upper guide plate to do linear motion by means of the piston rod, and drives the lower guide plate and the upper guide plate to do united or separated motion by means of the gear and rack intermediate driving mechanisms, so the L-shaped tool rest and the tool apron are driven to be opened or closed to realize the sealing and the cutting of packaging films. The L-shaped sealing mechanism has the advantages of uniformity in pressure, smooth cut, firm sealing opening, high plastic packaging efficiency and good sealing effect.

The carburizing process with pre-vacuumizing, protecting nitrogen-base atmosphere and no inner oxidation belongs to the field of heat treatment technology of metal material. The present invention has the hot treating furnace pre-vacuumized to 10-100 Pa, introduced with high purity nitrogen and heated to 900-1050 deg.c, before maintaining and introducing acetylene gas to carburize at nitrogen pressure of 0.1-0.11 MPa and acetylene gas pressure of 5000-20000 Pa. The present invention has no carbon black production, environment friendship, less oxidation of workpiece, low cost and high safety.

The invention relates to a frame for receiving annular components, in particular bearing rings or cages of rolling bearings or plain bearings, and for chemically or galvanically coating the componentsin an electrolyte bath. The frame comprises: a support frame which has at least one first drive unit, at least one second drive unit, and at least one horizontally arranged first transverse bracing,at least one drive motor for driving the at least one first drive unit, wherein the at least one first drive unit is drivingly connected to the at least one second drive unit; and at least two horizontally arranged drive pins, which can be rotated about their longitudinal axes and which are arranged on the at least one first transverse bracing, for receiving the annular components. The at least two drive pins are connected to the at least one second drive unit (4) so as to be driven by the at least second drive unit. The invention further relates to a method for chemically or galvanically coating annular components.

The body building scooter has head handlebar, two tread frames connected via connecting seat to the head handlebar, and wheels below the head handlebar and the tread frames. Each of the tread frames includes connecting rod, tread, wheel hinged via the wheel holder to the connecting rod, and repositioning spring connecting the wheel holder with the connecting rod. There are also one inner limiting block in the site for the connecting rod to be hinged to the connecting seat and two outer limiting pins outside the connecting rods. The present invention has the advantages of balanced two leg sports, flexible and variable sports modes, etc.

The invention relates to the field of orthopaedic medical equipment, and in particular to a multifunctional traction bed for orthopaedic treatment and rehabilitation, which comprises a bedstead, a bedboard arranged in the middle of the bedstead, and a traction frame assembly, a headboard and a footboard are respectively arranged at both ends of the bedstead, the bed board comprises a back bed board arranged close to the headboard, a leg bed board arranged close to the footboard, and a waist bed board arranged between the back bed board and the leg bed board, the leg bed board comprises a leftleg bed board and a right leg bed board, the left leg bed board and the right leg bed board are symmetrically arranged, a height adjustment assembly is arranged under the bedstead, liftable guardrailassemblies are arranged on both sides of the bedstead, and the traction frame assembly is arranged as a cuboid frame structure. The equipment is used for carry out stretching, traction, correction, relaxing and the like for an orthopaedic patient. When the patient receives treatment or rehabilitation, the upper body and the legs can be driven by the height adjustment assembly to go up or down, sothat the effect of exercise is achieved. The traction frame assembly can relax muscles, and can also help restore and correct bones.

The invention discloses an efficient concrete mixing device for municipal construction. The device comprises a feeding pipe, a batching tank, a shaking plate, stirring blades, a water storage tank, aspray row, a heater, a discharging pipe, a revolving drum and overturning scrapers, wherein the feeding pipe is arranged at the top end of the batching tank; one side of the shaking plate is hinged with the side wall of the top end of the batching tank; the water storage tank is arranged at the top end of the batching tank; a water pipe is arranged on the water storage tank; the spray row is arranged at an outlet end of the water pipe; a stirring motor is arranged on the side wall of the batching tank; the stirring blades are arranged on a rotating shaft; a screw impeller winds around the outer wall of the rotating shaft; one side of an inclined guide plate is hinged with the inner wall of the bottom end of the batching tank; the discharging pipe is arranged on the side wall of the batching tank; the heater is arranged on the inner wall of the bottom end of the batching tank; the revolving drum is arranged in the batching tank; the overturning scrapers are arranged on the external wallof the revolving drum. According to the efficient concrete mixing device for municipal construction, an appropriate ratio of concrete is guaranteed, preparation speed of the concrete is increased, preparation effect of the concrete is improved, the concrete is prevented from sticking to the bottom end, discharge of the concrete is accelerated, construction requirements are met, the device is simple in structure and convenient to use, and popularization is facilitated.

The invention relates a heat shield assembly (1), comprising at least two neighboring heat shields (2a, 2b), said shields being a first heat shield (2a) and a second heat shield (2b), each having a hot gas side (3a, 3b) and an opposing cold gas side (4a, 4b), wherein the heat shields (2a, 2b) have a neighboring side wall (6a, 6b) that connects the hot gas side (3a, 3b) and the cold gas side (4a, 4b), wherein a respective engagement pocket (5a, 5b), which is spaced from the hot gas side (3a, 3b) and the cold gas side (4a, 4b), is provided in the respective neighboring side wall (6a, 6b), wherein adjacent heat shields (2a, 2b) overlap one another and the one side wall (6a) of the first heat shield (3a) has a protrusion extending from the engagement pocket (5a) in the direction of the hot gas side (3a), wherein the protrusion has at least one protrusion side (7a); and a protrusion front edge (8a) connecting thereto, and wherein the second heat shield (2b) has a cutout that is essentially complementary to the protrusion and extending from the engagement pocket (5b) in the direction of the hot gas side (3b), wherein the cutout has at least one cutout side (7b) and a cutout rear edge (8b) connecting thereto, which are arranged such that, extending from the engagement pocket (5a, 5b), a gap (9) that is open toward the hot gas side (3a, 3b) is formed between the cutout and the protrusion, and wherein both the protrusion side (7a) and the cutout side (7b) have a gradient relative to the respective cold gas side (4a, 4b).

The ion generator for purifying and sterilizing device includes one support frame, one positive ion generator rack and one negative pole dust collector rack set alternately on the support frame, one positive ion generator and one negative pole dust collector in the corresponding racks separately, and one power source connected to the positive ion generator and the negative pole dust collector. The negative pole dust collector includes two negative pole tubes and one plate on one of the negative pole tubes; and the positive ion generator is one bipolar positive ion generator. The device of the present invention may be used in different air purifying apparatus, central air conditioner, household air conditioner, automobile, etc for purifying and sterilizing.

An optical pick-up actuator includes a lens holder, a magnetic circuit, a wire spring, a wire holder, and a damper material receptacle. The lens holder includes an objective lens. The magnetic circuit moves the lens holder. The wire spring is coupled at one end thereof to a side of the lens holder, and supports the lens holder. The wire holder fixes the other end of the wire spring. The damper material receptacle defines an insert hole and a through-hole, through which the other end of the wire spring is inserted and passes. The damper material receptacle holds a predetermined damper material that absorbs vibrations imparted on the wire spring. The damper material defines an injecting hole, through which the damper material is injected, separately from the insert hole and the through-hole.

The invention provides an auxiliary device and method for industrial robot hand-held demonstration. The method comprises the following steps that a horizontal direction sensor and a vertical directionsensor are arranged in a space, position information of an industrial robot is captured, and a space three-dimensional coordinate system is built in a computer; an absolute type encoder is arranged at a joint, and the initial state and the motion numerical value of the joint are recorded; a processor processes the numerical value to generate parameters and uploads the parameters to the computer,and the parameters are adjusted in the three-dimensional coordinate system of the computer, so that positioning is more accurate, and uniform demonstration points are generated. The method has the advantages that visual operation of direct demonstration is accurately combined with positioning of off-line demonstration, an operator does not need to program and conduct modeling study on off-line demonstration and only needs to master simple parameter adjustment, and then accurate positioning and motion uniformizing are achieved.

The invention provides an underground water monitoring well flowing water swirling flow packing method and packing equipment. According to the method, a water pump is placed in a well pipe for pumpingwater, a negative pressure state is presented in a borehole, a water supply pump is used for extracting slurry from a water tank on the ground to inject the slurry into a feeding funnel to form a swirling flow, then pebble materials or clay balls are put into the swirling flow, the swirling flow causes the pebble materials or the clay balls to be in a motion state, the situation that the funnel is blocked due to the precipitation of the pebble materials or the clay balls during rest is prevented, when the swirling flow enters a guide pipe, the water flow in the pipe can also be driven to be in a rotating state, the state can also drive the pebble materials or the clay balls to be in the rotating state, the rotation state enhances the power of the pebble materials or the clay balls to sink, the situation that gaps are blocked due to the accumulation of the pebble materials or the clay balls in the gap between the well wall and the well pipe is prevented, meanwhile, the annular hole canbe uniformly filled with the pebble materials or the clay balls, and the well completion quality is guaranteed.

The present invention relates to a pulse damper using a composite spring device for eliminating pulse waves in a plunger pump for supplying fuel so as to maintain the fuel pressure at a constant level without energy loss and to cover a wide range of pressure, which comprises a spring body (31), and a body (21) for receiving an O-ring spacer (23) supported by an internal O-ring cap (25), wherein a low pressure coil spring (51) and a high pressure disk spring (41) are arranged in a line inside the spring body (31) so that the low pressure coil spring (51) primarily works and then stops by making a low pressure spring cover (52) and a low spring pad (53) contact a low pressure spring stopper (34), and secondarily the high pressure disk spring (41) works and then stops by making a high pressure spring pad (14) mounted on one end of a spring guide shaft (12) connected to a piston (11); contact a high pressure spring stopper (33).

The invention discloses a sewage treatment device which comprises a barrel, wherein the barrel has a cavity structure; an opening slot and an empty slot are respectively formed on the two sides of thetop end of the barrel; a loading slot is formed on one side of the empty slot; a guiding plate is arranged on one end of the loading slot; a sewage pipe is connected with one end of the guiding plate; a vibrating mechanism is arranged in the barrel; a fixing pillar is arranged on one side of the vibrating mechanism; the other end of the fixing pillar is fixedly connected with an inner wall of thebarrel; a discharging mechanism is arranged at the opening on the top end of a separation plate. The sewage treatment device has following beneficial effects: a gear is driven to rotate by a second motor, so as to rotate the annular gear for driving fixing snap rings to push closing slices, to rotate the closing slices along a fixed direction of a fixed tray bolt and to close the closing slices toward the middle part for allowing the stirred sewage to flow out; on the contrary, the second motor is reversely rotated for dispersing the closing slices so as to allow the stirred sewage to fall off; the sewage treatment device has the advantages of simple structure, running stability, convenience in use, high stirring quality and high stirring efficiency.

A plug-in type valve special for an electro-hydraulic proportional steering engine is composed of a valve body, a pilot slide valve, an armature pushing rod, a proportional electromagnet, a pilot reset spring, a pilot valve end cap, a plug-in valve body, a plug-in valve element, a plug-in valve reset spring, a plug-in valve cap, a shuttle valve element and a shuttle valve base. The valve body is internally composed of a main oil channel and a pilot control oil channel, the main oil channel is composed of a left main valve hole, a right main valve hole, the plug-in valve body, the plug-in valve element, the plug-in valve reset spring, the plug-in valve cap, the shuttle valve element and the shuttle valve base, the pilot control oil channel is formed by the cooperation of a pilot valve hole and the pilot slide valve, the pilot reset spring is arranged at one end of the pilot slide valve and makes contact with the pilot valve end cap, the armature pushing rod of the proportional electromagnet is at the other end of the pilot slide valve and makes contact with the pilot slide valve, and the proportional electromagnet is connected with the valve body through a bolt for performing linear control over a control oil channel and then performing dynamic adjusting on the apertures of the plug-in valve body and the plug-in valve element of the main oil channel.

The invention discloses an air disc brake, which is provided with two driven adjusting mechanisms respectively located on two sides of a drive adjusting mechanism. Each of the driven adjusting mechanisms is provided with a driven gear, the drive adjusting mechanism is provided with a drive gear, the two driven gears mesh with the drive gear, and the two driven adjusting mechanisms are connected with a push disc. The push disc is pushed by the two driven adjusting mechanisms, and thrust of the two driven adjusting mechanism is transmitted to the push disc by the aid of the same drive adjustingmechanism in the same transmission manner and is uniform, so that the push disc can be driven to move stably, a brake block can be stressed uniformly, eccentric wear of the brake block can be avoidedeffectively, and the brake has higher stability and reliability in braking.

The invention discloses a double-membrane back pressure valve. The double-membrane back pressure valve comprises a valve body, a bonnet, a valve rod, a force measuring sensor, a spring, membranes, a damper, a display unit and the like and is characterized in that the upper membrane and the lower membrane are separated through a metal support piece to form a middle cavity, the spring and the damperare fixed on the upper membrane through a bottom plate, the upstream position of the lower membrane is provided with a small hole. When the double-membrane back pressure valve is used, a hand wheel is rotated to allow the valve rod to move downwardly, and the valve is closed; when fluid pressure is larger than a set value, the membranes upwardly compress the spring, the back pressure valve is opened, and fluid start flowing; when the fluid pressure is smaller than a set value, the spring pushes the membranes downwardly to close the back pressure valve, and fluid flowing is stopped. The double-membrane back pressure valve has the advantages that by the small hole, the fluid pressure is transmitted into the cavity between the two membranes, the upper membrane is uniformly stressed, the stress of the membranes, the spring and the damper is relatively balanced, and valve movement stability is achieved; by the damper, gentle valve movement is achieved, and disturbance to the flowing is reduced.